JPH0647635A - Screw tightening control device - Google Patents

Abstract

(57) [Summary] [Purpose] A screw that has been partially tightened can be automatically tightened. [Configuration] Number S0 for each step of the screw tightening program
01, S002, S003, S004, etc. are attached. The step No signal from the PC is input, and the screw tightening program is executed with the step indicated by this signal as the starting point. Memorize the step number and measure the stroke of the screw when restarting, or ID when restarting.
The start point may be specified by inputting. Instead of the step, the block corresponding to the screw hole may be restarted. [Effect] At restart, the start point can be set in the middle of the screw tightening program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric screw tightening device (electric nutrunner), and more particularly to a screw tightening control device for controlling the operation thereof.

[0002]

2. Description of the Related Art Electric nutrunners are widely used devices for automating screw tightening. In this device, a screw tightening controller is used to eliminate the inertia of the screw and tighten the screw with a desired torque. Also,
As a screw tightening controller, a configuration that detects a screw tightening failure is also known.

FIG. 39 shows the structure of a screw tightening device according to a conventional example. This figure shows Japanese Patent Laid-Open No. 2-1527.
33 is a simplified representation of the essential parts of the device disclosed in No. 33.

In the device shown in this figure, a motor 10 rotates a driver bit 12 to drive the driver bit 12
It has a structure that tightens the screw attached to the tip,
A rotation detector 14 is provided on the power transmission path from the motor 10 to the driver bit 12. The rotation detector 14 is a sensor that detects and outputs the rotation speed of the driver bit 12. That is, when the driver bit 12 rotates, the rotation detector 14 outputs a pulse signal having a pulse width according to the rotation speed, and inputs this to the counter 16 and the AND gate 18. When the output from the counter 16 is "H", the pulse signal output from the rotation detector 14 is input to the stop determination unit 20, and when the output from the counter 16 is "L", the pulse signal is not input.

When the output from the counter 16 is "H", the stop judging section 20 makes a judgment based on the pulse width of the pulse signal. As described above, the rotation detector 14
The pulse width of the pulse signal output from the motor 10 indicates the rotation speed of the output shaft of the motor 10. When the tightening of the screw approaches the end, the rotation speed of the output shaft decreases, resulting in a longer pulse width. The stop determination unit 20 determines whether or not the screw tightening should be stopped by determining the pulse width, and when it is determined that the screw tightening should be stopped, the normal rotation control unit 22 is cut off the normal rotation voltage and the reverse rotation control is performed. The section 24 is instructed to supply the reverse voltage. The forward rotation control unit 22 and the reverse rotation control unit 24 control the switching means 26 in response to this command to cut off the forward rotation voltage supplied from the power source (not shown) to the motor 10 and supply the reverse rotation voltage from the power source to the motor 10. Let Switching means 26
Therefore, the forward rotation voltage is supplied to the motor 10 when tightening the screw, while the reverse rotation voltage is supplied to the motor 10 when the screw tightening is completed, and the motor 10 is stopped after a short time has elapsed.

As described above, in the conventional example of FIG.
A reaction force is generated as the screw tightening progresses, and when the rotation speed of the driver bit 12 decreases due to this reaction force, the screw tightening is ended accordingly. As a result, it becomes possible to tighten the screw with a desired torque. Furthermore, in this conventional example,
The operation of opening and closing the AND gate 18 by the counter 16 makes it possible to detect a tightening failure.

In other words, when the motor 10 or its power source has an abnormality, the driver bit 12 is bent and cannot rotate normally, or the rotation detector 14 has an abnormality, the rotation detector 14 detects When the pulse signal output is not normally obtained, the AND gate 18 is closed. Therefore, the counter 16 counts the number of pulse signals generated within a predetermined time after the start of screw tightening and sets the output to "H" to open the AND gate 18 only when the number reaches the predetermined number. Therefore, in this conventional example, when an abnormality occurs, it can be detected and dealt with.

[0008]

However, this conventional example has a problem when a screw that has already been tightened once is tightened again.

First, when automatically tightening a screw using an electric nut runner equipped with a screw tightening program,
It must meet the specified equipment requirements. The equipment conditions include, for example, confirmation of a work clamp. If the work clamp is not confirmed, it is not preferable to directly tighten the screws. Therefore, it is necessary to interrupt the execution of the screw tightening program by using the abnormality detection function similar to the above-described conventional example to detect an inadequate equipment condition as an abnormality. In addition, screw tightening is interrupted when a defective work occurs.

When the screw tightening program is restarted in the state where the screw tightening is performed halfway, the entire screw tightening operation including steps such as temporary tightening and final tightening is executed. The judgment is bad. The screw tightening program installed on the electric nutrunner is
Usually, for example, it is determined whether or not a certain condition is satisfied when transitioning from temporary tightening to final tightening (temporary tightening determination), and whether or not a certain condition is satisfied when the screw tightening operation is finished. Is determined (final value determination). Therefore, conventionally, the screw tightening program cannot be restarted in the state where the screw tightening is performed halfway, and when using the electric nut runner, the screw must be completely loosened in advance using a hand tool, an impact wrench, etc. did not become.

The present invention has been made to solve the above problems, and an object of the present invention is to enable a screw to be properly tightened even if a screw tightening program is restarted. .

[0012]

In order to achieve such an object, the present invention is specified as step specifying means for specifying a step related to execution start from a plurality of steps constituting a screw tightening program. Restarting means for restarting the screw tightening program from the step described above, and the screw tightening control is executed from the middle step of the screw tightening program at the time of restart.

According to a second aspect of the present invention, the step specifying means includes means for detecting and measuring the state of the screw, and means for specifying the step related to the start of execution based on the detection measurement result.
It is characterized by including.

According to a third aspect of the present invention, the step specifying means comprises means for inputting information given to each screw, and means for specifying a step related to execution start based on the input information. Is characterized by.

According to a fourth aspect of the present invention, the screw tightening program is composed of a plurality of blocks respectively corresponding to the screw holes, and the execution is started from the plurality of blocks instead of the step specifying means. The block specifying means for specifying the block according to the above is provided, and the restarting means restarts the screw tightening program from the specified block, thereby executing the screw tightening control from the block in the middle of the screw tightening program at the time of restart. It is characterized by

[0016]

In the present invention, when the screw tightening program is restarted, one step is specified from a plurality of steps constituting the screw tightening program. Further, the execution of the screw tightening program is started from the specified step. Therefore, when the screw is partially tightened, it is possible to tighten the screw from an intermediate step.

Further, in claim 2, the step relating to the execution start is specified by the detection measurement of the state of the screw. Therefore, when specifying a step, an operation such as inputting a step number becomes unnecessary, and the step is further automated.

According to the third aspect of the present invention, the information given to each screw is input to specify the step related to the execution start. The information to be entered may be any information that can identify the step, and in addition to the information indicating the screw state, information that includes elements that cannot be obtained by measurement (tightening time, number of the tightening device, etc.). It may be. Therefore, it is automated in the same manner as in claim 2, and more detailed
Since the step is specified based on a wide variety of information, it is possible to perform screw tightening in a post process, another line, or the like.

According to another aspect of the present invention, when the screw tightening program is restarted, one block is specified from among a plurality of blocks constituting the screw tightening program.
The block corresponds to a screw hole for tightening a screw and includes, for example, a plurality of steps described above. The screw tightening program starts from the specified block. Therefore, for example, when the screw is restarted after removing the screw due to the occurrence of an abnormality related to the screw tightening, the screw tightening program can be started from the corresponding block.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a screw tightening device according to the first embodiment of the present invention. The device shown in this figure is composed of a controller 28 and a speed amplifier 30, and is configured to control a motor 34 in accordance with a tightening command from an equipment PC (programmable controller) 32.

First, the equipment PC 32 controls equipment such as machine tools installed in the factory. When the condition of the equipment is satisfied, the equipment PC 32 gives a tightening command to the controller 28 according to the equipment operation program as shown in FIG. 2, and starts the screw tightening program installed in the controller 28. When the controller 28 finishes executing the screw tightening program, the controller 28 notifies the facility PC 32 of that fact. In response to this, the equipment PC 32 executes necessary processing.

The controller 28 has an overall unit 36 and a speed control unit 38. The overall unit 36 is a unit that controls the overall operation of the controller 28, and the speed control unit 38 is a unit that gives a speed command to the speed amplifier.

The comprehensive unit 36 stores a screw tightening program as will be described later, and executes the screw tightening program in response to a tightening command from the equipment PC 32. The screw tightening program is, for example, as shown in FIG. 3, steps S001, S002,
It is composed of S003 and S004. In this example, in step S001, the motor 34 is rotated (SPEED) at a high speed (350 rpm), and the time (TIME) from the start is 3 seconds (I3) or the motor 3 is rotated.
Whether the shaft torque (TORQ) of 4 exceeds 50 kgcm,
This is a step related to the operation of "if any condition is satisfied, shift to step S002". Similarly, step S002 is "step S00 when the motor 34 is rotated at 50 rpm and the axial torque exceeds 200 kgcm.
This is a step related to the operation of "shifting to 3." Step S
003 is a step related to the operation of “rotating the motor 34 at 5 rpm and shifting to step S004 when the axial torque exceeds 500 kgcm”. Then, in step S004, a notification indicating the end of screw tightening is sent to the equipment PC 3
2 is a step relating to the operation. When such a screw tightening program is normally executed from the first step S001, the speed of the motor 34 is as shown in FIG. Are controlled as shown in FIG. 4 (b).

In order to execute the above control, the motor 34
Sensor 40 for detecting the axial torque of the motor and the motor 3
Angle / speed sensor 4 that detects the rotation angle and rotation speed of 4
2 must be provided on the output shaft of the motor 34. Also,
In order to capture the outputs of the torque sensor 40 and the angle / speed sensor 42, the controller 28 needs to be provided with the AD conversion unit 44 and the angle / speed detection unit 46. The AD converter 44 converts the analog output of the torque sensor 40 into the motor 34.
Converted to digital data showing the shaft torque of
Supply to 6. The angle / speed detection unit 46 is an angle / speed sensor 42 (for example, an encoder provided in the motor 34).
The output of the above is subjected to a predetermined process and is also supplied to the comprehensive unit 36.

The speed amplifier 30 includes a speed control unit 3
When a speed command is given from 8, the motor 3
4 current is controlled. That is, the speed amplifier 30 has a current command generator 48 that converts the speed command into a current command, and a current amplifier 50 that supplies a current to the motor 34 according to the current command. The speed command indicates a control target value of the rotation speed of the motor 34, and the current command indicates a current value corresponding to this target value. Therefore, the speed amplifier 30 can control the rotation speed of the motor 34 to a predetermined target value. The speed command is generated according to the screw tightening program, an example of which is shown in FIG.
The rotation speed of the motor 34 can be controlled according to the screw tightening program. Reference numeral 52 in the figure is a torque cut control unit that feeds back the output of the current amplifier 50 to the current command generation unit 48 to prevent excessive torque from being generated in the motor 34.

The structure of the controller 28 is shown in more detail in FIG. As shown in this figure, in the controller 28 of this embodiment, in addition to the general section 36, the speed control section 38, the AD conversion section 44 and the angle / speed detection section 46, the input / output sections 54 and 56 use the internal bus 58. It is the structure connected through. The input / output unit 54 is the equipment PC 3 described above.
In addition to the interface function with 2, the interface function with the programmer is provided. The input / output unit 56 has an interface function with the speed amplifier 30. In the figure, reference numeral 60 denotes a power supply unit that receives power supplied from an external power supply, converts the power appropriately, and supplies the power to each unit configuration of the controller 28, and reference numeral 62 denotes a power supply wiring related to this power supply.

FIG. 6 shows the general unit 36 in this embodiment.
Also, the configuration of the input / output unit 54 is shown. As shown in this figure, the comprehensive unit 36 includes a CPU 64, a ROM 66, and a RAM 68. The ROM 66 is a memory that stores a system program, and the RAM 68 is a memory that stores a screw tightening program (user program). The CPU 64 executes the processing related to these. That is, the CPU 64 converts the screw tightening program on the RAM 68 into a machine language by the system program, and executes the translated screw tightening program under the system program according to the tightening command from the equipment PC 32.

The input / output unit 54 also includes a PC interface 70 and a programmer interface 72. Communication between the equipment PC 32 and the controller 28 is performed via the PC interface 70 of the input / output unit 54. When the designer or maintenance person knows the internal state of the device, the programmer interface 72 of the input / output unit 54 is used.
The inside of the controller 28 is examined via.

The feature of this embodiment is that the ROM
66 has a step number processing routine 1000, and the corresponding PC interface 70 has a step number corresponding to this.
The point is that it has a signal input section 74. The step No signal input unit 74 is means for inputting a step No signal from the equipment PC 32, and the step No processing routine 1000.
Is the means to handle this. FIG. 7 shows a step No processing routine 1000 relating to the execution of the screw tightening program of the system programs stored in the ROM 66.
The flow of the part including is shown. Further, FIG. 8 shows the operation related to this processing.

When the apparatus of this embodiment is powered on (1
100), the CPU 64 first executes a self-diagnosis (1
102). This self-diagnosis is performed by the RAM 68 and the input / output unit 54.
It is to judge whether or not it can operate normally by checking the states such as. If the result of this diagnosis is abnormal, the CPU 64 keeps the current state while notifying the equipment PC 32, the user, etc. that the abnormality has occurred. If normal, the process proceeds to step 1104 and thereafter.

In step 1104, the CPU 64
Determines whether the step No. signal is input from the equipment PC 32. That is, the step No input unit 7
It is determined whether or not the step No. signal is input via 4. In the case of normal startup, the step No signal is not input. In this case, the CPU 64 sets the program start position to the beginning of the program (1106).

Next, the CPU 64 determines whether or not a tightening command (program start signal) has been input from the equipment PC 32 (1108). If not, the CPU 64 returns to step 1104 so as to wait until it is input. When input, the CPU 64 proceeds to step 1110.

In step 1110, the CPU 64
Executes the screw tightening program indicated by the program start signal from the program start position set in step 1106, that is, from the beginning. For example, when five types of screw tightening programs PGS1 to PGS5 are stored in the RAM 68 of the general unit 36, as shown in FIG. 8, the equipment PC 32 sends five types of screw tightening programs PGS1 to PG in response to a program start signal.
Any one of S5 is designated.

When the execution of the designated screw tightening program is completed as a result of such processing, the CPU 64 notifies the equipment PC 32 of that fact (1112), and step 11
Return to 04. As described above, according to this embodiment, the screw tightening program can be suitably executed.

Further, according to this embodiment, the RAM 68
It is also possible to execute the screw tightening program stored above from the middle. This operation is a feature of this embodiment, and is realized by step 1114 as follows.

That is, when it is determined in step 1104 that the step No signal is input from the equipment PC 32, the step designated by the step no signal is set as the program start position. As shown in FIG. 8, the equipment PC 32 has a step No.
The signal related to the start of execution is output from the signals SN1 to SN5, and the CPU 64 inputs the signal via the step No input unit 74. After executing the setting of the program start position, the CPU 64 proceeds to step 308.

In the following step 1110, the screw tightening program indicated by the program start signal is executed from the set program start position. Thereby, for example, in the case of the example of FIG. 3, step S0
It is possible to execute the processing from 02.

As described above, according to this embodiment, the screw tightening program can be started from an intermediate step as needed. Therefore, the same screw tightening program can be used when a screw tightening failure or the like occurs.
That is, it is not necessary to prepare a program from the start of the temporary fastening to the final and a program from the end of the temporary fastening to the final, and only one set value management is required.

FIG. 9 shows the structure of the screw tightening device according to the second embodiment of the present invention, particularly the general part 36 and the input / output part 54 of the controller 28 thereof. The other parts of this embodiment have the same structure as the first embodiment of FIGS. 1 and 5. 6 is different from that of FIG. 6 in that the program progress management routine 10 is stored in the ROM 68.
02 is mounted, a program counter 1004 is implemented on the RAM 68, and the PC interface 70 has a restart input section 76 instead of the step No input section 74.

FIG. 10 shows the CPU 6 in this embodiment.
4 shows the flow of a part including the operation relating to No. 4, particularly the processing relating to the step No processing routine 1000 and the program progress management routine 1002.

When the apparatus of this embodiment is powered on (1
200), the CPU 64 executes the same self-diagnosis as in the first embodiment (1202), and when it is abnormal, informs the fact to the equipment PC 32 or the user, and when it is normal, after step 1204. Proceed to. In step 1204, the CPU 64 inputs a tightening command, that is, a program start signal from the facility PC 32 via the PC interface 70, or a restart signal is input via the restart input unit 76. To judge.

In the case of normal start-up, the equipment PC 32 outputs a start signal. In this case, the CPU 64 sets the program start position to the beginning of the screw tightening program (1206), and the step No related to the execution start, that is, N in the first step of the screw tightening program in this case.
write o to the program counter 1004 (120
8). The CPU 64 executes the screw tightening program from the program start position on the program counter 1004, that is, from the beginning (1210). The RAM 68
If multiple screw tightening programs are installed on the
The program to be executed is designated by the equipment PC 32 by the start signal as in the first embodiment. Until the execution of the screw tightening program is completed (1212), the CPU 64 sequentially writes the No of the step to be executed next to the program counter 1004 (1208) and executes it (121).
0). When the execution of the screw tightening program is completed as a result of such processing (1212), the CPU 64 notifies the equipment PC 32 of that fact (1214), and returns to step 1204. As described above, according to this embodiment, the screw tightening program can be suitably executed.

Further, according to this embodiment, as in the first embodiment, it is possible to execute the screw tightening program stored in the RAM 68 from the middle. This operation is executed by the step No processing routine 1000.
Further, by the program progress management routine 1002,
The screw tightening program can be executed from an intermediate step without specifying the step number from the equipment PC 32.

That is, when it is determined in step 1204 that the restart signal is input from the equipment PC 32, the CPU 64 causes the program counter 1004
The above step No. is read (1216), and the screw tightening program is executed from the read step No. (12
10). Step No. on the program counter 1004
, If there is no previous cycle (12
18), the CPU 64 sets the beginning of the program as the program start position (1206) and executes the operation described above.

As described above, according to this embodiment, the screw tightening program can be started from an intermediate step as needed. Therefore, the same screw tightening program can be used when a screw tightening failure or the like occurs.
That is, it is not necessary to prepare both the program from the start of the temporary fastening to the final and the program from the end of the temporary fastening to the final, and one set value management is sufficient.

Further, according to this embodiment, the equipment PC 32
It is possible to continue the screw tightening operation executed in the previous cycle by inputting the restart signal from. Also, the memory of the previous cycle (program counter 2
The memory on 04) may be erased by using a reset signal. The reset signal may be generated, for example, when the jig is loosened and the work can be replaced.

FIG. 11 shows the main configuration of the screw tightening device according to the third embodiment of the present invention, particularly the controller 28 thereof. As shown in this figure, in this embodiment, two restart input sections 76 and 76 are mounted on the PC interface 70. The restart input unit 76 is means for inputting a restart signal similar to that of the restart input unit 76 in the second embodiment from the equipment PC 32. That is, in this embodiment, the equipment P
Of the two types of restart signals supplied from C32,
When a restart signal for restarting the screw tightening program is supplied from the step No. on the program counter, the restart signal is input to the controller 28 by the restart input unit 76. on the other hand,
The restart input unit 76 according to the feature of the present embodiment restarts the screw tightening program from the step in which the preset number of returns is returned from the two types of restart signals supplied from the equipment PC 32. It is a means for inputting a restart signal. That is, when the restart signal is supplied from the equipment PC 32, this restart signal is input to the controller 28 by the restart input unit 76.

FIG. 12 shows the CPU 6 in this embodiment.
4 shows the flow of operations including step No. processing routine 1000 and program progress management routine 1002.

When the power of the apparatus of this embodiment is turned on (1
200), the CPU 64 first executes the same self-diagnosis as in the first and second embodiments (1202), and when it is abnormal, informs the fact to the equipment PC 32 or the user, and when it is normal, Proceeds to step 1220.

In step 1220, the CPU 64
Sets the number of returns in step No. As described below,
When the restart signal is supplied from the equipment PC 32, the program returns from the step No. on the program counter 1004 to the predetermined step, and the execution of the program is started from the returned step No. The return number of the step No. set in step 1220 is such a step number
The number of steps to be returned on the screw tightening program during the returning process of.

After executing step 1220, step 12
The operation shifts to 04 and later. That is, step 120
In 4, CPU 64 is from the equipment PC 32 to the PC
It is determined whether a tightening command, that is, a program start signal or a restart signal is input via the interface.

In the case of normal start-up, the equipment PC 32 outputs a start signal. In this case, the CPU 64 sets the program start position to the beginning of the program (120
6), the step No. related to the start of execution, that is, the No. of the first step of the screw tightening program in this case is written in the program counter 1004 (1208). C
The PU 64 executes the screw tightening program from the program start position on the program counter 1004, that is, from the beginning of the program in this case (1210).
When a plurality of screw tightening programs are installed on the RAM 68, the facility PC 32 designates the program to be executed by the start signal. Until the execution of the screw tightening program is completed (1212), the CPU 64 sequentially writes the No of the next step to be executed on the program counter 1004 (1208) and executes it (12).
10). When the execution of the screw tightening program is completed as a result of such processing (1212), the CPU 64 notifies the equipment PC 32 of that fact (1214), and step 1204.
Return to. Also, when the start signal from the equipment PC 32 is turned off (1222), the process returns to step 1204.
As described above, according to this embodiment, the screw tightening program can be suitably executed.

Further, also in this embodiment, the RAM 68
It is also possible to execute the screw tightening program stored above from the middle. This operation is executed by the step No processing routine 1000. Further, the program progress management routine 1002 enables the screw tightening program to be executed from an intermediate step without designating a step number from the equipment PC 32.

That is, when it is determined in step 1204 that the restart signal or is input from the equipment PC 32, the CPU 64 reads the step number on the program counter 1004 (1216).
If the step number is not written in the program counter 1004 (1218), the operation of the CPU 64 proceeds to step 1206, and the screw tightening program is started from the beginning of the program. When the step number is written in the program counter 1004 (1218), the operation of the CPU 64 is step 1224.
Move to.

In step 1224, the CPU 64
Indicates whether the restart signal supplied from the equipment PC 32 is the restart signal input via the restart input section 76 or the restart signal input via the restart input section 76. judge. If the result of this determination is a restart signal, the CPU
The operation of 64 moves to step 1210. That is,
The screw tightening program is executed from the step No read in step 1216 (1210). On the other hand, if the signal is a restart signal, the CPU
64 executes the step No return processing (1226). That is, the return number set in step 1220 is subtracted from the step number on the program counter 1004 read in step 1216. After this,
By executing the step 1210, the screw tightening program is executed at the step N on the program counter 1004.
The execution is started from the step returned by a preset return number for o.

As described above, according to the present embodiment, the screw tightening program can be started from the block midway as needed. Therefore, the same screw tightening program can be used when screw tightening failure occurs. That is, it is not necessary to prepare both the programs from the start to the final tightening and the programs from the end to the final tightening, and one set value management is sufficient.

In addition to this, in the present embodiment, the equipment P
By inputting the restart signal from C32, the screw tightening operation executed in the previous cycle can be continued. In addition, by inputting the restart signal from the equipment PC 32, it becomes possible to interrupt the screw tightening action executed in the previous cycle and continue the screw tightening operation after manually tightening the new screw halfway.

The memory of the previous cycle may be erased by using a reset signal. For example, this reset signal may be generated when the jig is loosened and the work is replaced.

FIG. 13 shows the main configuration of the screw tightening device according to the fourth embodiment of the present invention, particularly the controller 28 thereof. As shown in this figure, in this embodiment, the restart input section 76 is used as the restart input section.
Only installed. That is, in the case of this embodiment,
From the equipment PC 32, only the restart signal for starting the execution of the screw tightening program is supplied from the step returned from the step No. on the program counter 1004.

FIG. 14 shows the CPU 6 in this embodiment.
4 shows the flow of operations including the operations relating to Step No. 4, particularly the step No processing routine 1000 and the program progress management routine 1002.

As shown in this figure, the operation of the CPU 64 in this embodiment is the operation obtained by removing the step 1224 from the operation in the third embodiment. That is, the equipment P
Since the restart signal that can be supplied from C32 is only the restart signal, when it is determined in step 1218 that there is a step No, step 1224 is executed without reducing step 1224.

Therefore, according to this embodiment, the screw tightening program can be started from an intermediate step as needed. Therefore, the same screw tightening program can be used when screw tightening failure occurs.
That is, it is not necessary to prepare both the program from the start to the final fastening and the program from the end to the final fastening, and one set value management is sufficient.

Further, according to this embodiment, the equipment PC 32
By inputting the restart signal from, the screw tightening action executed in the previous cycle can be interrupted, the new screw can be half tightened by hand, and the operation can be continued. Note that the memory of the previous cycle may be erased by using a reset signal. For example, this reset signal may be generated when the jig is loosened and the work is replaced.

FIG. 15 shows the structure of a screw tightening device according to the fifth embodiment of the present invention. As shown in this figure, in this embodiment, a stroke sensor 78 is provided on the output shaft side of the motor 34. In response to this, the controller 28 is further provided with a stroke detection unit 80.

FIG. 16 shows the structure of the stroke sensor 78 in this embodiment. However, the angle / speed sensor 42 is omitted. Especially (a) is before sitting
(B) shows the respective states after sitting.

The stroke sensor 78 in this embodiment
Is a sensor that detects the positional relationship between the socket 82 and the output shaft of the motor 34. The socket 82 is a member provided so as to be connected to the output shaft of the motor 34, and the head portion 86 of the screw 84 to be tightened is fixedly attached to the lower portion. The stroke sensor 78 is a head 88 provided on the socket 82.
And a sensor unit 90 fixed to the motor 34,
It consists of When the screw 84 is tightened on the work 92 by the rotational driving of the motor 34, the spring 94 provided at the upper portion changes the positional relationship between the socket 82, that is, the head 88 and the sensor unit 90. The sensor unit 90 detects the amount of change in the positional relationship with the head 88, and outputs a signal indicating the amount of change to the stroke detection unit 80.

In the figure, 96 is a socket sensor,
It is detected whether the head 86 of the screw 84 is completely attached to the socket 82.

FIG. 17 shows the configuration of the controller 28 in this embodiment. As shown in this figure, a stroke detector 80 is added in this embodiment. Further, FIG. 18 shows the configuration of the general unit 36 in this embodiment. As shown in this figure, in the present embodiment, the ROM 66 is equipped with a stroke detection processing routine 1006, and a stroke setting unit 1008 is provided on the RAM 68. The stroke detection unit 80, the stroke detection processing routine 1006, and the stroke setting unit 1008 are the features of this embodiment.

FIG. 19 shows the CPU 6 in this embodiment.
4 shows a flow of operations including the step No routine 1000, the step progress management routine 1002, and the stroke detection processing routine 1006.

When the apparatus of this embodiment is powered on (1
300), the CPU 64 executes the same self-diagnosis as in the first to fourth embodiments (1302), and when it is abnormal, informs the fact to the equipment PC 32 or the user, and when it is normal, Proceed to step 1304 and subsequent steps.

In step 1304, the CPU 64
Determines whether a flag indicating that the stroke detection process is to be executed is set on the stroke setting unit 1008. When not standing, the CPU 64 sets the program start position to the beginning of the screw tightening program (130
6) In response to the start signal from the equipment PC 32 (13
08), the screw tightening program is executed from the set program start position (1310). At this time, the screw tightening program to be executed is designated by the program start signal. When program execution is completed (1
312), the CPU 64 notifies the equipment PC 32 to that effect, and proceeds to step 1304. As described above, according to this embodiment, the screw tightening program can be suitably executed.

Furthermore, according to this embodiment, as in the first to fourth embodiments, it is possible to execute the screw tightening program stored in the RAM 68 midway. In this embodiment, this operation is executed by the stroke of the screw 84. Therefore, the stroke setting unit 10
The stroke of the screw 84 is written in advance in 08. The screw tightening control operation based on the stroke written in the stroke setting unit 1008 is executed by the stroke detection processing routine 1006.

First, when it is determined in step 1304 that the stroke setting unit 1008 has set a flag, step 1314 is executed. In step 1314, the workpiece 92 has arrived at the fixed position and the socket 82
A signal that the head 86 of the screw 84 is completely attached,
That is, it is determined whether or not the signal from the socket sensor 96 of the stroke sensor 78 is obtained. When this condition is satisfied, the CPU 64 proceeds to step 1316.

In step 1316, the CPU 64
Reads the positional relationship between the socket 82 and the sensor unit 90, that is, the positional change amount of the head 88 with respect to the sensor unit 90 from the stroke sensor 78 by the stroke detection unit 80. The read position change amount is compared and referred to by the stroke on the stroke setting unit 1008 by the CPU 64 (1318), whereby the tightened state of the screw 84 is grasped. For example, it is determined whether the screw 84 is currently in the temporarily tightened state or in the fully tightened state after seated.
The stroke sensor 78 is sufficient to read the stroke up to temporary tightening (up to seating). When the position change amount read from the stroke sensor 78 is smaller than the stroke on the stroke setting unit 208, it can be considered that the screw 84 is not seated and is in the temporarily tightened state,
It will be understood that the screw tightening program may be executed from the steps related to temporary tightening (S001, S002, etc. in the above example). The read position change amount is the stroke setting unit 20.
If the stroke is 8 or more, the screw 84 is already seated, and it is understood that the screw tightening program may be executed from the step (S003 in the above example) related to the final tightening.

Thereafter, the step No processing routine 100
Step 1320 relating to 0 is executed. That is, C
The PU 64 determines the step number related to the program start position from the tightened state grasped in step 1318.
Is specified, and the process proceeds to step 1308.

As described above, according to the present embodiment, the screw tightening program can be started from the middle step. Therefore, the same screw tightening program can be used when a tightening failure or the like of the screw 84 occurs. That is, it is not necessary to prepare both the program from the start of the temporary fastening to the final and the program from the end of the temporary fastening to the final, and one set value management is sufficient.

Further, according to the present embodiment, since the tightening state of the screw 84 is grasped based on the detected value of the stroke, it is not necessary to set the step No in advance, and the operation is more automated. The same effect can be realized by measuring and detecting a physical quantity indicating the degree of progress of screw tightening instead of the stroke detection in this embodiment.

FIG. 20 shows the structure of a screw tightening device according to the sixth embodiment of the present invention. This embodiment is provided with an I / D carrier 98 which is conveyed together with the work 92 and has information indicating the tightened state of the screw 84, and the I / D carrier 98 is provided.
It is characterized in that an I / D controller 100 for reading information indicating the tightened state of the screw 84 from the carrier 98 and supplying it to the controller 28 is provided. Further, the I / D controller 100 has an I / D antenna 102 for receiving information from the I / D carrier 98, and the controller 28 inputs the information from the I / D controller 100 to the general unit 36. It has a communication control unit 104 for performing.

FIG. 21 shows the configuration of the controller 28 in this embodiment, and FIG. 22 shows the configuration of the general unit 36. As shown in these figures, the general unit 36 of this embodiment has a communication processing routine 1010 mounted on the ROM 66 for exchanging information with the communication control unit 104, and an I / D setting unit on the RAM 68. 1012 are configured.

FIG. 23 shows the CPU 6 in this embodiment.
Of the operations of 4, the step No processing routine 1000,
The flow of operations relating to the program progress management routine 1002 and the communication processing routine 1004 is shown.

When the power of the apparatus of this embodiment is turned on (1
400), the CPU 64 executes the same self-diagnosis as in the first to fifth embodiments (1402), and when it is abnormal, informs the fact to the equipment PC 32 or the user, and when it is normal, Proceed to step 1404 and subsequent steps.

In step 1404, the CPU 64
Reads the flag from the I / D setting unit 1012 on the RAM 68. In the I / D setting unit 1012, when the flag related to I / D reading and processing is not set, the CPU
Similarly to the fifth embodiment, 64 sets the program start position at the beginning of the screw tightening program (1406), and according to the start signal from the equipment PC 32 (1408), sets the screw tightening program specified by the program start signal. The program is executed from the set program start position (1410), and upon completion of the program execution (141
2) Then, the facility PC 32 is notified of this and step 141
Go to 4. The CPU 64 uses the I / D controller 100 to input information indicating the tightened state of the screw 84 to the I / D.
Write to carrier 98 (1414), step 140
Go to 4. As described above, according to this embodiment, the screw tightening program can be suitably executed. Even if the screw tightening program cannot be executed to the end and ends, the I / D
Writing to the carrier 98 is performed.

Further, according to this embodiment, as in the first to fifth embodiments, the screw tightening program stored in the RAM 68 can be executed midway. In this embodiment, this operation is executed by the information on the I / D carrier 98. First, when it is determined in step 1404 that the stroke setting unit 1008 has set a flag, step 1416 is executed. In step 1416, it is determined whether the work 92 has arrived at the fixed position and the information on the I / D carrier 98 can be read. When this condition is satisfied, the CPU 64
The process moves to step 1418.

In step 1418, the CPU 64
Is executed by executing the communication processing routine 1010.
/ D Read the information on the carrier 98, and then screw 84
The tightening state of the is grasped (1420). The information written on the I / D carrier 98 is previously stored in step 14
The information written in 14 is, for example, the tightening torque of the screw 84. For example, when the tightening torque read from the I / D carrier 98 when executing the screw tightening program of FIG. 3 is 300 kgcm, it can be seen that the tightening state of the screw has already proceeded to step S003.

After reading the tightening state of the screw 84, the CPU 64 sets the step number related to the program start to, for example, S003 or the like in accordance with this (142)
2) Then, the process proceeds to step 1408.

As described above, according to this embodiment, the screw tightening program can be started from the middle step. Therefore, the same screw tightening program can be used when a tightening failure or the like of the screw 84 occurs. That is, it is not necessary to prepare both the program from the start of the temporary fastening to the final and the program from the end of the temporary fastening to the final, and one set value management is sufficient.

Further, according to the present embodiment, since the tightening state of the screw 84 is recorded / understood by writing / reading information to / from the I / D carrier 98, it is not necessary to preset the step No. , It becomes a more automated operation. Furthermore, there is no need to measure strokes and the like. In addition, the information recorded on the I / D carrier 98 is not limited to measurable information such as torque, and thus can be more detailed and diversified information. For example, the information may include the number of revolutions of the motor 34 when the screw 84 is tightened, the time when the screw is tightened, the number of the nut runner that is tightened, and the like.

Further, the present invention can be applied to an automatic assembly machine in which the screw tightening device has a work management function. An automatic assembly machine used in a manufacturing process of an automobile or the like has a configuration in which an orthogonal three-axis type positioning device and an electric screw tightening device are combined. FIG. 24 shows an example of the structure of an automatic assembly machine according to the seventh embodiment of the present invention.

The apparatus shown in this figure is a facility PC 32,
It comprises a positioning device 106, a screw tightening device 108, and a quality control personal computer 110. Equipment PC 32
Manages the control of the entire automatic assembly machine and controls the positioning device 10
6, the position of the screw tightening device 108 is aligned with the position of the bolt and nut of the product. The screw tightening device 108 is a device that operates according to a screw tightening program and tightens a screw on a workpiece. The equipment PC 332, the positioning device 106, and the screw tightening device 108 operate while exchanging signals with each other. Further, the quality control personal computer 110 appropriately inputs the operation status of the screw tightening device 108 and manages the screw tightening quality for the work.

FIG. 25 shows the internal structure of the equipment PC 32. The equipment PC 32 includes a power supply unit 112, a CPU unit 114, a memory unit 116, input units 118, 120 and 1.
22 and output units 124, 126 and 128. The power supply unit 112 takes in an external power supply and supplies power to each unit of the equipment PC 32. The CPU section 114
Each unit of the equipment PC 32 is controlled according to the program stored in the memory unit 116.

The input unit 118 and the output unit 124 form an input / output unit related to the positioning device 106. That is, C
The PU unit 118 gives a positioning device start signal or a positioning device restart signal to the positioning device 106 via the output unit 124 when the positioning device 106 performs positioning according to the program on the memory unit 116. When the positioning is completed, the positioning device 106 supplies a signal to that effect to the CPU section 114 via the input section 118. Similarly, the input unit 120 and the output unit 126 constitute an input / output unit for the screw tightening device 108, and
The PU unit 114 outputs the output unit 126 to the screw tightening device 108.
A signal to start the screw tightening device is given via
A signal of completion of screw tightening is received from the screw tightening device 108 via the input unit 120. Then, the CPU unit 114
Through the input unit 122 and the output unit 128, the control and state grasp of each part of the manufacturing apparatus are performed. The input unit 122 is an input unit for inputting the state of the push button switch (SW) of each site operated by a human and the limit switch (SW) for confirming the position of each site, and the output unit 128 is
It is an output unit for outputting to a relay for turning on and off a solenoid (SOL) valve for operating each part and a motor.

FIG. 26 shows the internal structure of the positioning device 106. As shown in this figure, the positioning device 106 includes a power supply unit 130, a CPU unit 132, a memory unit 134, an axis control unit 136, an output unit 138, and an input unit 1.
It has a controller composed of 40. That is, the positioning device 106 has a controller having a configuration similar to that of the equipment PC 32. The power supply unit 130 is a member that takes in an external power supply and supplies power to each unit of the controller, and the input unit 140 and the output unit 138 are the equipment PC 3
An input / output unit for 2 is configured. The CPU section 132 gives a signal to the axis control section 136 in accordance with a positioning program stored in the memory section 134, and causes the axis control section 136 to perform positioning with respect to the work by a configuration described later. At that time, C
The PU unit 132 executes this program in response to a start or restart signal given from the equipment PC 32 via the input unit 140, and when the positioning is completed, outputs a signal via the output unit 138 to the equipment. It is notified to the PC 32 by giving it.

The axis control section 136 is a section for controlling the orthogonal three axes (X, Y, Z axes) relating to positioning under the control of the CPU section 132. The axis control unit 136 gives a speed command to the speed amplifiers 142-X, 142-Y and 142-Z related to each axis, and the speed amplifiers 142-X, 142-Y, 1
42-Z receives a power supply from the drive power supply and supplies a drive current to the corresponding motors 146-X, 146-Y and 146-Z in response to this command. Motor 146-X,
The rotation angle and speed of 146-Y and 146-Z are detected by the angle / speed sensors 144-X, 144-Y and 144-Z and fed back to the axis controller 136. As a result, each axis is controlled under the axis control unit 136, and the work and the screw tightening device 108 are positioned.

FIG. 27 shows the internal structure (for one axis) of the screw tightening device 108. As is clear from this figure, the screw tightening device 108 also has a controller 28 having substantially the same configuration as the positioning device 106 and having the same functions as those of the first to sixth embodiments. The controller 28 includes a power supply unit 60, a CPU unit 148, and a memory unit 15.
0, axis control unit 152, output unit 154, input unit 156, and communication unit 158. The power supply unit 60 takes in an external power supply and supplies power to each unit of the controller 28. The CPU unit 148 controls the controller 28 according to the system program stored in the built-in ROM 66.
Control each part of. The CPU unit 148 takes in a start signal from the equipment PC 32 via the input unit 156, and accordingly starts the screw tightening program on the memory unit 150. When the screw tightening operation is completed, the CPU unit 1
48 outputs a signal to that effect to the equipment PC 32 via the output unit 154. The communication unit 158 is a circuit for communication between the CPU unit 148 and the quality control personal computer 110.

The axis controller 152 controls the screw tightening operation under the control of the CPU 148. That is, the axis control unit 1
The reference numeral 52 gives a speed command to the speed amplifier 30 to drive the motor 34 to tighten the screw. The motor 34 includes an angle / speed sensor 42 and a torque sensor 4
0 is provided, and these outputs are fed back to the axis control unit 152. That is, the angle / speed sensor 4
The rotation angle and speed of the motor 34 detected by 2 and the output torque of the motor 34 detected by the torque sensor 40 are supplied to the CPU unit 148 via the axis control unit 152. In the screw tightening device 108 as well, the speed amplifier 30 and the motor 34 are driven by a drive power source different from the controller 28.

FIG. 28 shows the internal structure of the controller 28 in this embodiment. As shown in this figure, the respective members except the power supply unit 60 are connected to each other by an internal bus 58, and operate while exchanging signals or information.

First, the axis control unit 152 includes a calculation unit 160,
It is composed of an A / D converter 44 and an angle / speed detector 46. A / D converter 44 and angle / speed detector 46
Are torque sensor 40 and angle / speed sensor 4 respectively.
It is a member that takes in the output of 2. The A / D converter 44
The output of the torque sensor 40 is converted into digital data and input to the arithmetic unit 160. The angle / speed detection unit 46 detects the rotation angle / speed of the motor 34 from the output of the angle / speed sensor 42, and inputs it to the calculation unit 160 as well. Computing unit 1
The reference numeral 60 includes a CPU 162, a ROM 164, a RAM 166, and a speed command calculation unit 168. The speed command calculation unit 160 calculates the speed command based on the outputs of the A / D conversion unit 44 and the angle / speed detection unit 46, and the speed amplifier 3
Output to 0. At this time, the speed command calculation unit 168 is the CPU
The calculation is executed under the control of 162. CPU 162
Manages the speed command calculation process while exchanging signals with the CPU unit 148. ROM 164 and RAM 166
Is used for storing programs, coefficients and the like relating to speed command calculation in the calculation unit 160.

The memory section 150 also has a RAM 68 in which a screw tightening program section 1014, a work state storage section 1016 and a program counter 1004 are mounted. The CPU unit 148 is a CP that mounts the determination unit 1018.
It is composed of a U 170 and a ROM 66. Of the programs necessary for the screw tightening operation, the screw tightening program created by the user is installed in the RAM 68 as the screw tightening program unit 1014, and the system program is installed in the ROM 66 or the like. CPU 170 is a ROM
In accordance with the system program on 66, the screw tightening program section 1 is stored in the RAM 68 in response to a signal from the equipment PC 32.
The screw tightening program stored as 014 is executed. As a result, the CPU 170 gives a command to the axis control unit 152, and determines whether the result of the screw tightening operation by the axis control unit 152 is good or bad by the determination unit 1018.

A work management unit 1020, a block processing unit 1022, and a program progress management routine 1002 are further mounted on the ROM 66. The work management unit 1020 and the work state storage unit 1016 described above.
Is a configuration relating to work management in a screw tightened state, which is the first feature of this embodiment. Regarding the work management, the applicant of the present application has previously disclosed it in Japanese Patent Application No. 4-194326. Also, the block processing unit 1022 on the ROM 6
And a program progress management routine 1002 and the RAM 6
The program counter 1004 on the No. 8 has a configuration related to the block start, which is the second feature of the present embodiment, together with a block start input unit 1024 described later. The work management and block start will be described in detail later.

The communication unit 158 includes the CPU 172 and the ROM 1
74, RAM 176 and communication processing unit 178. The CPU 172 executes a program related to communication with the quality control personal computer 110 in response to a command from the CPU unit 148, and the communication processing unit 178 executes data processing and the like necessary for communication. The ROM 174 and the RAM 176 are
At that time, the necessary programs and coefficients are stored.

The input section 154 has the function of inputting a start signal from the equipment PC 32 as described above, and is equipped with the block start input section 1024 as means for inputting a block start signal from the equipment PC 32. When the start signal is supplied from the equipment PC 32,
The input unit 154 inputs this, and the CPU 170 stores the ROM
According to the system program on 66, the screw tightening program stored in the RAM 68 as the screw tightening program unit 1014 is executed. At that time, the work management unit 1020 on the ROM 66 is activated, and the screw tightening state for the work is managed for each work. At this time, RA
The work state storage unit 1016 on M68 is used to store the final value of the tightening torque (final torque value) and its determination result for each work. On the other hand, when the block start signal is supplied from the equipment PC 32, the input unit 15
This block start signal is input from the block start input unit 1024 of the No. 4, and the CPU 170 causes the ROM 66 to
The screw tightening program stored in the RAM 68 as the screw tightening program unit 1014 is executed according to the above system program. At that time, the CPU 170 uses the ROM 6
6 starts the block processing unit 1022 and the program progress management routine 1002, and while appropriately reading / writing the contents of the program counter 1004, starts the screw tightening program from the middle block. Even in such an operation, that is, in the block start of the screw tightening program, the CPU 170 activates the work management unit 1020 to manage the screw tightening state for each work, as in the normal start.

FIG. 29 is a block diagram showing the construction of the main part of this embodiment, that is, the construction of the work management section 1020 in the CPU section 148 and the work state storage section 1016 in the memory section 150.
The configuration of is shown. As shown in this figure, the work management unit 1020 has a work management processing unit 1026 and a hole position processing unit 1028, and the work state storage unit 1020.
16 includes a hole position state storage unit 1036 including a final torque value storage unit 1030, a torque process storage unit 1032, and a determination result storage unit 1034. The hole position state storage unit 1036 is the same as the work state storage unit 1016.
There are usually a plurality of holes depending on the number of hole positions. The final torque value storage unit stores the torque values in the final torque value table described later, and the determination result storage unit 1034 stores the determination content in the determination storage table. The torque process storage unit 1032 stores the process up to the final torque.

30 to 32 show the flow of the operation of the CPU 170 in this embodiment, particularly the operation including the work management unit 1020, the block management unit 1022 and the program progress management routine 1002.
33 to 35 show an example of the screw tightening operation in this embodiment. In particular, FIG. 33 shows equipment 1
FIG. 35 is a cycle diagram showing a cycle for each division of control elements, FIG. 34 is a diagram conceptually showing the movement of the apparatus according to this cycle diagram, and FIG. 35 is a facility PC 3 at that time.
FIG. 2 is a diagram showing a signal transmission / reception mode (program execution mode) between the positioning device 106 and the screw tightening device 108.

In the cycle diagram shown in FIG. 23, the transfer device operates in the order of ascending, advancing, descending and retracting by the equipment PC 32. When the transfer retreat is entered and the jig is tightened, the equipment PC 32 gives a start signal to the positioning device 106 to start the operation. In the example shown in FIG. 33, the hole positions targeted for screw tightening are A,
Since there are three positions B and C, the positioning device 106 first performs positioning related to screw tightening at the hole position A. In this case, the X and Y axes are as shown in FIG. 34 (X _A , Y _A ).
Then, the Z axis is positioned at Z _A. When the positioning is completed, the positioning device 106 sets the equipment PC 3
Send a signal to 2. Upon receiving this, the equipment PC 32 gives a signal to the screw tightening device 108 to execute screw tightening. The screw tightening device 108 tightens screws in the order of temporary tightening and final tightening. When the final tightening is completed, the screw tightening device 108
Informs the equipment PC 32 of this. Equipment PC 32
Responsively provides a signal to the positioning device 106. In response to this signal, the Z axis of the positioning device 106 is Z _0.
Be positioned at. Z ₀ is the origin of the Z axis. In FIG. 34, two motors 34 for screw tightening are used in pairs.

Such a series of operations, that is, the operation from the positioning of the X and Y axes to the positioning to the origin of the Z axis,
This is repeated for each hole position A, B, C. When the positioning of the Z-axis related to the hole position C to the origin is completed, the X-axis and the Y-axis are further positioned at the origin (X ₀ , Y ₀ ), and at the same time, the jig loosening is executed and one cycle of the equipment is completed. Ends.

In such a series of operations, the equipment PC
The flow of signal transmission / reception by the 32, the positioning device 106, and the screw tightening device 108 is as shown in FIG. 35 in more detail.

In this operation, the positioning device 106 operates according to the positioning program stored in the memory section 134, and the screw tightening device 108 operates in the memory section 1.
Screw tightening programs 1, 2, 3, stored in 50
Operates according to.

First, the equipment PC 32 controls the transfer device in the order of ascending, advancing, descending and retracting. When the transfer is retreated, the equipment PC 32 performs a jig tightening and then gives a start signal to the positioning device 106.
The positioning device 106 responds to the X,
Position the Y axis at (X _A , Y _A ), and set the Z axis at Z _A
To position. When the positioning is completed, the positioning device 106 gives a signal to that effect to the equipment PC 32. Equipment P
C32 gives a start signal to the screw tightening device 108 in response to this signal. The screw tightening device 108 executes a predetermined program in response to this signal. When the program indicated by 1038-1 in the figure is executed and the screw tightening operation is completed by this program, the screw tightening device 108 gives a signal to that effect to the equipment PC 32.

When the screw tightening device 108 gives a signal indicating that the screw tightening is completed, the equipment PC 32 gives a restart signal to the positioning device 106 in response to the signal. After that, when the same operation is repeated for each hole position, the equipment operation as shown in FIG. 33 is realized.

Further, as shown in FIGS. 34 and 35, in this embodiment, the program is created for each work unit. That is, each program 1038-
1, ..., 1038-n are composed of blocks for each hole position. For example, the program 1038-1 is composed of blocks 1040-1, 1040-2 and 1040-3, and by executing this program 1038-1, the screw tightening relating to the three hole positions A, B and C is performed. It can be performed.

As shown in FIG. 30, the screw tightening device 1
When the power of 08 is turned on (1500), the CPU 170
Thereby, self-diagnosis of the memory unit 150, the input unit 154, the output unit 156, etc. is executed (1502). When it is determined as abnormal as a result of this diagnosis, the fact is notified to the equipment PC 32, and the controller 28 suspends the operation and maintains the current state. If it is determined to be normal, the operation of the controller 28 proceeds to step 1504 and subsequent steps.

In step 1504, the CPU 17
0 reads the screw tightening program (user program) stored in the RAM 68 as the screw tightening program unit 1014. At that time, the work management processing unit 1026 and the hole position processing unit 10 which constitute the work management unit 1020.
28 grasps the block configuration and axis configuration of the read screw tightening program respectively (1506), and based on the results, creates a final torque value table and a judgment memory table respectively (1508).

FIG. 36 shows an example of the final torque value table. Further, FIG. 37 shows an example of the judgment storage table. The final torque value table and the determination memory table shown in these figures are examples in the case of two motors 34 (that is, two axes), and further relate to the program 1 configured from three blocks 1 to 3. Here is an example. The final torque value table and the determination storage table are tables for storing the final torque value related to screw tightening and the determination result for each block of the screw tightening program and for each axis (motor 34). That is, when the execution of a certain block is completed, the final torque value output from the torque sensor 40 is written in the final torque value table for each axis, and the final torque value is set to a predetermined target torque value. It is judged whether it is within the range (OK) or not (NG), and the judgment result is written in the judgment storage table. For example, the target torque value is 50
If it is 0 kgcm, it is OK if the target torque value is 10 kgcm above and below, otherwise it is NG.
And The final torque value table and the determination storage table are tables for writing and managing the final torque value and the determination result thereof in the steps described below, and are actually a set of the hole position state storage unit 1036. Step 1508
In FIG. 36, the framework is first constructed, for example, as shown in FIG. 36, based on the analysis and grasping result of the block configuration and the axis configuration.

The CPU 170 creates such a final torque value table and a judgment storage table for each program. That is, prior to step 1506, the program number is initialized to 1 (1510), and if it is recognized that there is another program after executing step 1508 (1512), the program number is incremented (1514) and steps 1506 and 1508 are repeated. Run.

When these processes are completed for all programs, the CPU 170 writes the block No. and step No. at the beginning of the program on the program counter 1004 so that the program start position will be the beginning of the screw tightening program (1515). ). CPU17
After that, 0 waits for a start signal to be issued from the equipment PC 32 (1516).

The equipment PC 32 gives a start signal to the positioning device 106, as shown in FIG.
After each axis is positioned at a predetermined position by the positioning device 106, a start signal is given to the screw tightening device 108. The CPU 170 of the screw tightening device 108 determines the program to be executed based on the program No. included in the start signal, and executes the corresponding program (1518). At that time, the CPU 170 causes the CPU of FIG.
As shown in 1, the block number and step number written on the program counter 1004 are read (1520).

When the program No given by the start signal from the equipment PC 32 indicates the program 1038-1 shown in FIG. 35, for example, the CPU 170
Begins execution at its first block 1040-1. When executing the program, if the command to be executed at present is a screw tightening command (1522), the CPU 170 gives a command to the axis control unit 152 to execute screw tightening (152).
4). At the stage where this screw tightening is performed, if a series of screw tightening actions related to the corresponding hole positions are not completed (152
6), the CPU 170 determines the next block No. and step N
write o to the program counter 1004 (152
8) If the start signal from the equipment PC 32 remains ON (1530), the process returns to step 1522. vice versa,
When the start signal is turned off, the CPU 170
The operation moves to 1532. This allows the CPU 170
In this state, a signal input from the equipment PC 32 is awaited.

In step 1532, the CPU 17
0 indicates that a start signal is input from the equipment PC 32 to the input unit 154 or the block start input unit 1024.
It is determined whether a block start signal is input to. When the start signal is input from the equipment PC 32, C
The PU 170 starts execution of the screw tightening program from the step represented by the block number and the step number read from the program counter 1004 (153).
4) and returns to step 1522.

On the contrary, when the block start signal is input from the equipment PC 32 to the block start input unit 1024, the CPU 170 causes the program counter 1004
Is corrected to the head step of the block indicated by the block start signal (1536). CP
The U170 modifies the contents of the program counter 1004, and then modifies the modified block No. and step N
Start the screw tightening program from o (153
8). After that, the operation of the CPU 170 returns to 1522.

If it is determined in step 1526 that the series of screw tightening actions relating to the corresponding hole positions have been completed, the CPU 170 causes the CPU 170 to execute step 154 shown in FIG.
Move to 0. In step 1540, CPU1
70 determines whether or not the block that has completed the screw tightening action is the first block. If the result of this determination is that it is the first block, the CPU 170 sets the block number to 1 (1542). On the contrary, if it is not the first block, 1 is added to the block number (154).
4). After executing step 1544, the CPU 170 writes the final torque value in the final torque value table and the determination result in the determination storage table (1546). That is, step 15
46 When the No at the time of execution is 1, the final torque value and the determination result are written in the column relating to the first block of the final torque value table and the determination storage table, and when the block No is 2, The final torque value table and the judgment storage table are written, such as writing in the column related to the block of No. 2.

In the case of the examples shown in FIGS. 36 and 37, the number of axes is 2 and the number of blocks constituting the program is 3. When the final torque value related to the first axis is 505 kgcm and the final torque value related to the second axis is 510 kgcm, as shown in FIG. 9 (a), the final torque value table shows these 505 kgcm and 510 kgcm. The value is written. The target torque value is 500 kgcm and it is OK.
When the range determined to be ± 10 kgcm is ± 10 kgcm, all of these values are determined to be OK, and that effect is written in the determination storage table. Further, when the block No is 2 and therefore the block being executed is 1040-2, as shown in FIG. 9B, the final torque value and the final torque in the column of the block 2 of the determination storage table are shown. The value and the judgment result are written. Similarly, when the block No. is 3 and the execution block is 1040-3, FIG.
As shown in (c), writing to the column of block 3 is executed. In these writings, the final torque value related to the second axis when executing block 2 is 480 kgcm.
Since it is out of the range of 500 kgcm ± 10 kgcm, NG is written in the corresponding column of the determination memory table.

After execution of step 1546, the CPU 170
Determines whether the executed block is the last block (1548). C if not the last block
The operation of PU 170 is step 153 shown in FIG.
The process shifts to 2 and the system waits for a signal from the equipment PC 32.
If it is the last block, the process related to the end of the program, for example, the communication process to the quality control personal computer 110 by the communication unit 158 is executed (1550), and FIG.
The process returns to step 1516 shown in FIG. 9 to wait for a start signal from the equipment PC 32. If it is determined in step 1522 that it is not the screw tightening instruction, it is further determined whether or not it is a waiting instruction (1552). If it is the waiting instruction, it is the same as when it is determined that it is not the last block. , Transition to the state of waiting for a signal from the equipment PC 32 (15
32) If the instruction is not a wait instruction, an error display is executed (1554).

As described above, in the present embodiment, the screw tightening operation for each hole position forms a total of three blocks on the program and one program is created for each work. The screw tightening action related to the position can be managed by the block concept, and the screw tightening action related to one work can be managed by the program concept. Further, when each block is executed, the final torque value of each axis in the block and the pass / fail judgment result are written in the final torque value and the judgment storage table. Position state storage unit 103
6 is created for each work. Therefore, according to the present embodiment, the screw tightening state can be managed for each work.

Further, in the case of a device in which the screw tightening state cannot be managed as a work, the judging unit 1 is executed before the screw tightening cycle is executed.
It is necessary to reset 018. The processing time required for this reset is from the equipment PC 32 to the screw tightening device 10
8 time required for transfer (about 0.1 s to 0.2 s),
The total time (about 0.3 s) for clearing the determination unit 1018 by this signal, that is, about 0.5 s. When such an action is executed for each hole position, for example, when there are three hole positions, a total of about 1.5 s,
This will affect the cycle time of the equipment. However, when the determination result is stored for each work as in the present embodiment, it is not necessary to reset the determination unit 1018 for each hole position. Therefore, it is sufficient to perform the reset once for each work, and the influence on the cycle time of the equipment becomes smaller.

Furthermore, in the present embodiment, in addition to the effect related to such work management, the effect related to block start can be enjoyed. That is, the screw tightening program can be started from an intermediate block as needed. Therefore, for example, even when a screw tightening failure occurs, the same screw tightening program can be used, and it is necessary to prepare both the program from the temporary tightening start to the final tightening and the program from the temporary tightening end to the final tightening. Instead, only one set value management is required.

Furthermore, by supplying a block start signal from the equipment PC 32 while the operation of the screw tightening device 108 is stopped midway, the screw tightening operation executed in the previous cycle can be continued. Equipment PC3
In No. 2, since the hole position (block) related to the execution start can be designated by this block start signal, it is applicable even when the worker performs screw rework or the like after the screw tightening device 108 is stopped halfway. Hole position (block)
It is possible to execute the screw tightening program from the beginning. Memory of previous cycle (program counter 100
4) may be erased by a reset signal.
The reset signal may be generated, for example, when loosening the jig and replacing the work.

In the above description, the controller 28
Was controlled by the equipment PC 32, but it may be controlled by another device.

[0129]

As described above, according to the present invention,
Since the step related to the start of execution is specified and the screw tightening program is restarted, even when the screw is tightened halfway, it is possible to preferably perform tightening of the screw from the middle step. As a result, the number of steps involved in tightening a screw that has been tightened halfway is reduced.

Further, according to claim 2, since the step related to the execution start is specified by detecting and measuring the state of the screw, an operation such as inputting a step number is not necessary for specifying the step, which is more automated. An advanced device can be obtained.

According to the third aspect, since the step related to the execution start is specified by inputting the information given to each screw, the automation is promoted as in the second aspect, and more detailed / diversified information is obtained. Since the step is specified on the basis of the information on the above, it is possible to perform the screw tightening in the post process, another line, or the like.

According to the fourth aspect, since the block related to the execution start, that is, the screw hole is specified and the screw tightening program is restarted, even when the screw is removed and the screw is tightened again, the corresponding screw hole is removed. The screw tightening can be restarted from. Therefore, after the work in which the abnormality has occurred is repaired, the screw tightening can be preferably restarted from the beginning of the corresponding block.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a screw tightening device according to first to fourth embodiments of the present invention.

FIG. 2 is a diagram illustrating activation of a screw tightening program (user program) by an equipment PC.

FIG. 3 is a diagram showing an example of a stepped screw tightening program (user program).

FIG. 4 is a diagram showing a screw tightening operation by the program of FIG. 3, FIG. 4 (a) is a diagram showing a change in speed, and FIG. 4 (b) is a diagram showing a change in torque.

FIG. 5 is a block diagram showing an internal configuration of a controller in the first to fourth embodiments.

FIG. 6 is a block diagram showing a main configuration of the first embodiment.

FIG. 7 is a flowchart showing the operation of the CPU in the first embodiment.

FIG. 8 is a diagram illustrating restart of a screw tightening program (user program) according to the first embodiment.

FIG. 9 is a block diagram showing a main configuration of a second embodiment.

FIG. 10 is a flowchart showing the operation of the CPU in the second embodiment.

FIG. 11 is a block diagram showing a main configuration of a screw fastening device according to a third exemplary embodiment of the present invention.

FIG. 12 is a flowchart showing the operation of the CPU in the third embodiment.

FIG. 13 is a block diagram showing a main configuration of a screw tightening device according to a fourth exemplary embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the CPU in the fourth embodiment.

FIG. 15 is a block diagram showing a schematic configuration of a screw tightening device according to a fifth exemplary embodiment of the present invention.

FIG. 16 is a diagram illustrating a stroke detection operation in the fifth embodiment.

FIG. 17 is a block diagram showing an internal configuration of a controller in the fifth embodiment.

FIG. 18 is a block diagram showing a main configuration of a fifth embodiment.

FIG. 19 is a flowchart showing the operation of the CPU in the fifth embodiment.

FIG. 20 is a block diagram showing a schematic configuration of a screw tightening device according to a sixth exemplary embodiment of the present invention.

FIG. 21 is a block diagram showing an internal configuration of a controller in the sixth embodiment.

FIG. 22 is a block diagram showing a main configuration of a sixth embodiment.

FIG. 23 is a flowchart showing the operation of the CPU in the sixth embodiment.

FIG. 24 is a diagram showing an example configuration of an automatic assembly machine according to a seventh embodiment of the present invention.

FIG. 25 is a block diagram showing the configuration of an equipment PC (programmable controller) in the seventh embodiment.

FIG. 26 is a block diagram showing an example configuration of a positioning device according to a seventh embodiment.

FIG. 27 is a block diagram showing an example configuration of a screw tightening device according to a seventh embodiment.

FIG. 28 is a block diagram showing an internal configuration of a controller of the screw tightening device in the seventh exemplary embodiment.

FIG. 29 is a block diagram showing a main structure of a seventh embodiment.

FIG. 30 is a flowchart showing a part of the operation of the CPU in the seventh embodiment.

FIG. 31 is a flowchart showing a part of the operation of the CPU in the seventh embodiment.

FIG. 32 is a flowchart showing a part of the operation of the CPU in the seventh embodiment.

FIG. 33 is a cycle diagram showing an example of an equipment cycle.

FIG. 34 is a diagram showing the cycle diagram of FIG. 33 in association with each axis.

FIG. 35 is a diagram showing an execution form of a screw tightening program (user program) in the seventh embodiment.

FIG. 36 is a diagram showing an example of a final torque value table.

FIG. 37 is a diagram showing an example of a determination storage table.

FIG. 38 is a diagram showing a process of writing the final torque value and the determination result in the final torque value table and the determination storage table, (a)
FIG. 3 is a diagram illustrating a write operation during execution of the first block, (b) during execution of the second block, and (c) illustrating a write operation during execution of the third block.

FIG. 39 is a block diagram showing a configuration of a screw tightening device according to a conventional example.

[Explanation of symbols]

28 controller 30 speed amplifier 32 equipment PC 34 motor 36 general section 38 speed control section 40 torque sensor 42 angle / speed sensor 44 AD conversion section 46 angle / speed detection section 54,56 input / output section 64,162,170 CPU 66 ROM 68 RAM 70 PC interface 74 Block No. signal input section 76, 76, 76 Restart input section 78 Stroke sensor 80 Stroke detection section 82 Socket 84 Screw 86 Screw head 88 Head 90 Sensor section 92 Work 96 Socket sensor 98 I / D Carrier 100 I / D controller 102 I / D antenna 104 Communication processing unit 106 Positioning device 108 Margining device 148 CPU unit 150 Memory unit 152 Axis control unit 154 Output unit 156 Input unit 158 Communication unit 160 calculation unit 168 speed command calculation unit 1000 step No processing routine 1002 program progress management routine 1004 program counter 1006 stroke detection processing routine 1008 stroke setting unit 1010 communication processing routine 1012 I / D setting unit 1014 screw tightening program unit 1016 work state storage unit 1018 Judgment unit 1020 Work management unit 1022 Block processing unit 1024 Block start input unit 1026 Work management processing unit 1028 Hole position processing unit 1030 Final torque value storage unit 1032 Torque process storage unit 1034 Judgment result storage unit 1036 Hole position state storage unit 1038- 1, ... 1038-n Program 1040-1, 1040-2, 1040-3 Block S001, S002, S003, S004 Screw tightening Program of step PGS1, PGS2, PGS3, PGS4, PGS5 program start signal SN1, SN2, SN3, SN4, SN5 step N
o signal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Eguchi, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor, Akihiro Takeuchi 1, Toyota Town, Aichi Prefecture, Toyota Motor Co., Ltd.

Claims (4)

[Claims] 1. A program storage means for storing a screw tightening program, a means for inputting a start signal, a starting means for starting the screw tightening program according to the start signal, and a means for controlling screw tightening according to the screw tightening program. ,
In a screw tightening control device comprising: a step specifying means for specifying a step related to execution start from a plurality of steps constituting the screw tightening program, and a restart means for restarting the screw tightening program from the specified step, And a screw tightening control device that executes the screw tightening control from the middle step of the screw tightening program at the time of restart. 2. The screw tightening control device according to claim 1, wherein the step specifying means includes means for detecting and measuring the state of the screw, and means for specifying the step related to the execution start based on the detection measurement result. A screw tightening control device characterized in that 3. The screw tightening control device according to claim 1, wherein the step specifying unit specifies a unit for inputting information given to each screw and a step related to the execution start based on the input information. And a means for controlling screw tightening. 4. A program storing means for storing a screw tightening program for executing screw tightening for a plurality of screw holes, a means for inputting a start signal, and a starting means for starting the screw tighten program according to the start signal. A block tightening control device comprising: a means for controlling screw tightening according to the screw tightening program; and a block specifying block for specifying execution start among a plurality of blocks corresponding to the screw holes, each of which composes the screw tightening program. A screw tightening control device comprising: a means and a restarting means for restarting the screw tightening program from the specified block, wherein the screw tightening control is executed from a block in the middle of the screw tightening program at the time of restart.