JPH044082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention particularly relates to a chuck replacement jaw measuring device for an NC machine tool. In other words, whether or not the multiple jaws that are automatically installed and replaced on the chuck of the NC machine tool are the designated jaws that correspond to the workpiece (hereinafter referred to as the work), or whether the replaced jaws are installed correctly. This is a measuring device that measures whether the NC machine tool is in the correct position, and if it is determined not to be in the correct position, it stops the NC machine tool and issues an alarm to notify you of this.

[Conventional technology]

Conventionally, there has been known an automatic jaw changing device that uses a robot device or the like to automatically change and attach the jaws of the chuck of an NC machine tool in accordance with the workpiece. In order to automatically determine whether the attached claw is the predetermined claw corresponding to the workpiece or whether the replaced claw is in the correct mounting position, it is necessary to use a dedicated measuring tool for each individual. Or, the one that only checks whether the replaced jaw is the specified jaw, measures the exact installation position, and if it is determined not to be the same, stops the NC machine tool and issues an alarm. Nakatsuta.

[Problem that the invention seeks to solve]

In particular, the present invention provides a robot device between a feeder that supplies a workpiece or a pallet of replacement jaws and an automatic jaw exchanger or a chuck having an automatic jaw exchange function, so that the jaws of the chuck or the workpiece can be automatically exchanged. If the replacement nail pallet that holds multiple nails is not set in the designated place on the feeder and is placed in the wrong place, or if a different nail than expected is held on the replacement nail pallet, etc.
A claw that does not correspond to the workpiece will be attached to the chuck.

Furthermore, even if the next scheduled jaw is accurately transported by the robot device, incorrect exchange may occur due to some reason, such as a flaw in the exchange and delivery operation between the robot and the chuck, or a grasping error in the robot hand. Sometimes the installation is completed and you move on to the next step.

In the next process, the chuck claws may not be able to automatically grip the workpiece, or the mounting position of the workpiece may suddenly change during machining due to incorrect or uncertain mounting, resulting in the workpiece being dropped. This can lead to serious accidents such as nails flying off. In addition, the machining cutter (tool) may be damaged, and there are other problems such as deterioration of machining accuracy due to inaccurate gripping of the workpiece, resulting in defective workpieces.

[Means for solving problems]

As a means to solve the above-mentioned problems, this invention provides a touch sensor that measures the position of the chuck of a replaced NC machine tool, and a touch sensor that measures the position of the chuck from the spindle axis or its vicinity. An approach motion processing means for the touch sensor that performs the motion, and a preset tolerance value that calculates the difference between the previous measurement value and the current measurement value when the touch sensor is brought into contact with the nail multiple times by the approach motion processing means. a dispersion determining means for determining dispersion by comparing the values with the dispersion, a memory means for memorizing the machine coordinate value when the touch signal is output, and a memory for a claw position setting value for storing the coordinate value of the preset claw attachment position. and if the difference between the measured values is larger than the tolerance value, the measurement operation is repeated, and if the difference between the measured values is smaller than the tolerance value, the touch signal is output. a pawl position determining means that captures the machine coordinate value when the pawl is installed as a measured coordinate value and compares it with the set pawl position set value to determine whether the pawl attachment position is a planned attachment position; The chuck replacement pawl measuring device for a machine tool is characterized in that the chuck replacement pawl measuring device comprises a central control device for controlling the chuck means, and the chuck position is confirmed by each of the aforementioned determining means.

[Effect]

With the above-mentioned configuration, the approach operation processing means of the touch sensor operates in response to a claw measurement start command signal from the central controller, and the touch sensor quickly moves to the spindle axis or its vicinity, and then moves to the vicinity of the chuck's claw. Move up to.

Then, the touch sensor moves in the direction of the nail, that is,
The touch signal generated when the finger moves in the axial direction and comes into contact with the claw activates the variation determination means that determines the variation in the measured value of the claw position, and calculates the difference between the previous measurement value and the current measurement value by a preset tolerance value. Compare with to determine the variation.

As a result of the judgment, if the difference between the measured values is smaller than the tolerance value, the claw position judgment means operates according to the dispersion judgment signal of the measured claw position values, and determines whether the accuracy of the mounting position of the claw is less than the claw position tolerance. The judgment is made, and if it is within the claw position tolerance, the replacement installation is OK and the process moves to the next step in the machining program. Furthermore, if the accuracy of the jaw mounting position is greater than the jaw position tolerance, the NC machine tool is stopped and an alarm is sounded to notify the user of this.

〔Example〕

Figure 1 shows the main parts around the chuck of an NC machine tool related to this invention, the chuck jaws and a robot device that automatically supplies workpieces, the upper stage holds multiple different types of workpieces, and the lower stage shows replacement jaws corresponding to the workpieces. FIG. 3 is a diagram showing a two-stage feeder on which a plurality of held replacement claw pallets are placed. A headstock 2 is provided on the bed 1, and a chuck 3 provided at the tip of a main shaft 2a which is pivotally supported by the headstock 2 is rotatably driven by a motor (not shown). Chuck 3 has an automatic claw replacement function,
A plurality of claws 4 are automatically replaced by the claw delivery operation of the robot device 15. Multiple claws 4 that grip the workpiece
is attached to the tip side of this chuck 3. Also, along the guides 5, 5 provided on the bed 1,
A saddle 6 is provided to be freely movable in the axial direction, and movement of the saddle 6 in the Z-axis direction is performed by a ball screw 7 rotated by a motor (not shown). A tool post 9 is provided to be movable in the X-axis direction along guides 8, 8 provided on the saddle 6, and the movement of the tool post 9 in the X-axis direction is driven by a ball screw rotated by a motor (not shown). Conducted by U10. The front of this turret 9 (chuck 3
On the side), a disk-shaped tool rest turret 11 is vertically provided, which can be rotated under control to select the machining tool to be used. A plurality of machining tools 12 are attached to the periphery of the tool post turret 11. Further, an arm 13 is attached to the tool rest 9 so as to be able to perform transfer and retreat operations from the tool rest 9, and a touch sensor 14 is attached to the tip of this arm 13.

Further, on the front side of the bed 1, there is provided a robot device 15 equipped with a robot hand 15a for gripping a workpiece or a replacement claw pallet, which will be described later. In front of this robot device 15, different types of workpieces W are placed on a plurality of mounting tables 16a connected to each other so as to be able to rotate continuously on the upper horizontal plane.
A plurality of claws (jiyos) 4 that can be replaced according to the workpieces are mounted on the upper workpiece feeder 16' on which the workpieces are placed, and the lower stage mounting table 16b which is connected so as to be able to rotate continuously on a horizontal surface. A two-stage feeder 16 is provided, which includes a lower stage feeder 16'' on which the held replacement claw pallet J is placed. The robot hand 15a grasps a predetermined workpiece W and transports it to the claw 4 of the chuck 3 to hold it, or the robot hand 15a replaces a predetermined claw 4 corresponding to the workpiece W, so that the claw 4 is held. The claw pallet J is grasped and conveyed to the chuck 3, and the claws 4 are delivered and attached thereto.

Figure 2 shows the control system diagram of the NC machine tool and the system diagram of the chuck replacement jaw measuring device.
(referred to as CPU) 17 via bus line 18.
The NC machine tool and each element constituting this invention are connected as follows.

First, a keyboard with a screen 19 for inputting and outputting necessary information is connected to the CPU 17 via an interface 20 and a bus line 18. The information is stored in the machining schedule memory 21, the machining program memory 22, and the pawl measurement program memory 23, respectively, such as the program number, replacement pawl pallet number, workpiece number, and number of pieces to be machined. Through
Connected to CPU17.

Before performing machining based on the machining program stored in the machining program memory 22, it is checked whether the jaws attached to the chuck are compatible with the workpiece or whether the jaws are correctly attached. Measure. For this reason, for example, a servo motor 24 that drives the touch sensor 14 for measuring the claw position, which is attached to the tool rest 9 or the tool rest 9 so as to be able to perform transfer/retreat operations, in the X and Z axis directions is connected to the amplifier 25 and the interpolator. position control circuit 2 including
6 and a bus line 18 to the CPU 17 . The touch sensor 14 is electrically connected to a claw position measuring circuit 27 and an interface 28.
and is connected to the CPU 17 via a bus line 18.

Further, the two-stage feeder 16 is connected to the CPU 17 via a feeder controller 29, an interface 30, and a bus line 18.

Also, the operator may grasp a desired workpiece W on the work feeder 16' of the two-stage feeder 16 and convey it to the claw 4 of the chuck 3 and hold it, or grab a desired replacement claw pallet J of the jaw feeder 16'' and hold the claw 4 thereon. A robot device 15 for transporting the robot to the chuck 3 for delivery and installation is connected to the CPU 17 via a robot controller 31, an interface 32, and a bus line 18.

Furthermore, the various components of the chuck replacement claw measuring device are connected to the CPU 17 as follows.

That is, the first AND gate 33 is connected so that the nail measurement program data is output in response to the nail measurement start command signal from the bus line 18.

The output data from this first AND gate 33 is transmitted to the approach motion processing section 3 of the touch sensor 14.
It is connected so that it is applied to one input terminal of 4. The first AND gate 33 and the approach motion processing section 34 constitute approach motion processing means A of the touch sensor 14.

Further, a machine coordinate value register 35 that always stores the coordinate values from the origin of the X-axis and Z-axis of the tool rest 9 and the touch sensor 14 attached to the tool rest 9 is connected to the CPU 17 via the bus line 18. The output from the machine coordinate value register 35 is connected to the other input terminal of the approach motion processing section 34.

The approach operation processing unit 34 is connected so that an output signal for performing the next stage operation, that is, a start signal S for the dispersion determination operation, is applied to one input terminal of the second AND gate 36a. At the other input terminal of the AND gate 36a,
The touch sensor 14 is connected so that a touch signal generated when it comes into contact with the claw 4 of the chuck 3 is applied.

The touch signal from the touch sensor 14 is also applied to the approach motion processing section 34.

The output signal from this second AND gate 36a is connected so as to be applied to the input terminal of a counter setting section 37a, and one output terminal of this counter setting section 37a outputs the previously measured claw position measurement signal (a _-1 signal) as the third AND gate 38
is connected so that it is applied to one input terminal of the .
Further, the other output end of the counter setting section 37a is connected so as to be applied to one input end of the fourth AND gate 39 as a currently measured claw position measurement signal (referred to as a signal). Further, a fifth add gate 36b is provided to temporarily hold the machine coordinate value Xm in the register 37b as the measured coordinate value X when the variation determination start signal S and the touch signal are output. This measured coordinate value X is determined by the third and fourth AND gates 38,
39.

A register 40 is provided for storing the output from the third AND gate 38 as the previously measured pawl position measurement value Xa _-1 . Said fourth
A register 41 is provided which stores the output from the AND gate 39 as the currently measured claw position measurement value Xa.

Claw position measurement values of these registers 40 and 41
Xa _-1 , Xa is the variation determination unit 42 of the claw position measurement value
The output data of the variation tolerance register 43 connected to the bus line 18 is also connected to the other input terminal. This variation determination unit 42 determines how much variation there is between the previously measured claw position measurement value Xa _-1 and the currently measured claw position measurement value Xa, and the variation tolerance Δa (for example, 5 microns) is determined. If the NG signal is larger than the NG signal output from the NG output terminal, the counter setting section 37a
and is applied to the bus line 18 to redo the claw position measurement. The counter setting section 37a is configured to alternately output the a _-1 signal and the a signal every time there is an NG signal. Further, a set number of repetitions is set in the counter setting section 37a, and when the number of repetitions of the touch signal reaches the set number of times (an integer value, for example, 5, etc.), the bus line 1
A signal to that effect is transmitted to the CPU 17 via the CPU 8.

The second AND gate 36a, the counter setting section 37a, and the third, fourth, and fifth AND gates 3
8, 39, 36b and register 37b, register 4
0. The register 41 and the variation determining section 42 constitute a variation determining means B that determines variations in the measured values of the claw positions.

When the variation is smaller than the variation tolerance Δa, the OK signal output from the OK output terminal is connected to be applied to one input terminal of the sixth AND gate 44, and the other input terminal of the sixth AND gate 44 is connected to the OK signal output from the OK output terminal. The input terminal is connected to receive the measured coordinate value X from the register 37b. The measured coordinate value X output from the sixth AND gate 44 is processed by the claw position data processing unit 45 to determine the diameter and overshoot of the contact of the touch sensor 14, and
A claw position measurement value Xj is calculated. This claw position measurement value Xj is connected to be applied to one input terminal of the claw position determination section 46, and the other input terminal is connected to the bus line 18 and stores the claw position setting value _X0 . The other input terminal is connected to the bus line 18 so that the data from the claw position tolerance register 47 in which the claw position tolerance value Δj is stored is applied. Connected so that data is applied.
Then, the claw position determination unit 46 determines the claw position measurement value.
The difference between Xj and the claw position setting value X ₀ is determined, and if the difference is larger than the claw position tolerance Δj, that is, |Xj−
In the case of X ₀ | > Δj, an NG signal is output from the NG output terminal, which is applied to the bus line 18 to stop the machine and also activates an alarm (not shown).
sound. If the above |Xj−X ₀ | is smaller than the claw position tolerance Δj, an OK signal is output from the OK output terminal, and is applied to the bus line 18.
The NC machine tool performs the following process operations.

The sixth AND gate 44, the pawl position data processing section 45, the pawl position determining section 46, the pawl position setting value register 47, and the pawl position tolerance register 48 constitute a pawl position determining means C.

Next, the operation of the present invention will be explained based on the schematic diagrams showing the movement of the touch sensor 14 shown in FIGS. 2 and 3, and the flowchart of the operation shown in FIG. 4.

According to the machining program in the machining program memory 22, a nail measurement start command signal is sent from the CPU 17 via the bus line 18 to the first AND gate 3.
3, the nail measurement program data is output to the approach motion processing section 34. Further, from the mechanical coordinate value register 35, a mechanical coordinate value, which is the operating position of the touch sensor 14, is input to the approach motion processing section 34. The control data from the approach motion processing unit 34 is transmitted via the bus line 18 to a position control circuit 26 including an interpolator.
is applied to the servo motor 2 via the amplifier 25.
4 is controlled. Touch sensor 14 in Figure 3A
As shown in step 101 in FIG. 4, the touch sensor 14 is moved quickly so that the X-axis direction is on the spindle center CL, and the Z-axis direction is on the end surface 4a of the claw 4.
approach in front of. Next, touch sensor 14 is connected to step 1 of FIG. 3A and FIG.
As shown by 02, the measurement position is approached in the Z-axis direction. Then, the touch sensor 14 is moved at a rapid rate in the X-axis direction to a point slightly beyond the target position, as shown in FIG. 3B and step 103 in FIG. Therefore, as shown in step 104 in FIG.
determines whether the touch sensor 14 comes into contact with the claw 4 and receives a touch signal.
3B and step 105 of FIG.
As shown in , return the touch sensor 14 to the front of the claw 4 in the X-axis direction. In step 104,
When a touch signal is issued, the signal is input to the approach motion processing section 34, and the approach motion processing section 34 sets and stores that it is the first touch signal. This is a preparatory operation for starting the next stage dispersion determination operation (second touch signal).

Next, as shown in step 106 of FIG. 4, the touch sensor 14 is brought into contact with the claw 4 in a slow direction in the X-axis direction, and as shown in step 107, the touch sensor 14 comes into contact with the claw 4 and a touch signal is generated. Determine whether or not. If there is a touch signal at this time,
The approach motion processing section 34 outputs the start signal S of the dispersion determination motion to the second AND gate 36a, assuming that this is the second touch signal. The output signal of the second AND gate 36a is applied to the input terminal of the counter setting section 37a, and the number of measurements is set to 1 in the counter setting section 37a, and the first measured claw position is set from one output terminal. Although the measurement signal is output, the counter setting section 37
At a, the a _-1 signal is emitted as it is the pawl position measurement signal measured last time. This is because each time a repeated measurement is performed, the current measured value and the immediately previous measured value are compared and determined.

Further, when the touch signal is applied to the fifth AND gate 36b together with the start signal S, the mechanical coordinate value Xm of the mechanical coordinate value register 35 is changed to the register 37b.
It is temporarily held as the claw position coordinate value X.

By applying the a _-1 signal to the third AND gate 38, the measured coordinate value X of the register 37b passes and is temporarily stored in the register 40 as the previous claw position measurement value Xa _-1 (step 108). .

Next, as shown in step 109, the touch sensor 14 returns to the front of the nail in the X-axis direction, and in step 110 it is determined whether it is the first measurement.Since this is the first measurement (YES), the process returns to step 106 and touches the nail again. Next, an operation is performed to obtain a pawl position signal.

When the touch signal is issued, the output signal from the second AND gate 36a is input to the counter setting section 37a, and the number of measurements = 2 is set.
The currently measured claw position measurement signal (signal a), which is alternately and repeatedly output, is output from the other output end of the counter setting section 37a. This is applied to one input terminal of the fourth AND gate 39.

Further, in response to the touch signal, the mechanical coordinate value Xm at this time is taken into the register 37b as the measured coordinate value X from the fifth AND gate 36b.

By applying the a signal to the fourth AND gate 39, the measured coordinate value X of the register 37b passes and is stored in the register 4 as the current claw position measurement value Xa.
1 is temporarily stored. Then, as shown in step 109, the touch sensor 14 is returned to the front of the claw 4 in the X-axis direction every time the claw position measurement is performed several times.

Claw position measurement values of these registers 40 and 41
When Xa _-1 ,
As shown in step 111 in the figure, the dispersion between the currently measured pawl position measurement value Xa and the previously measured pawl position measurement value Xa _-1 is determined, and if the dispersion is larger than the dispersion tolerance Δa (for example, 5 microns), NG
An NG signal outputted from the output terminal is applied to the counter setting section 37a and the bus line 18 to restart the claw position measurement. As shown in step 112, the claw position measurement is performed a set number of times (an integer value, e.g. 5
If the set number of times has not been reached, the claw position is measured again as shown in FIG. 3C.

At this time, the counter setting section 37a outputs the a _-1 signal by receiving the NG signal, and transfers the measured coordinate value X of the register 37b to the third AND gate 38.
is temporarily stored in the register 40 as the previous claw position measurement value. That is, the current claw position measurement value Xa (second time) is replaced with the previous claw position measurement value Xa _-1 . Then step 1 in Figure 4
Returning to step 06, the touch sensor 14 performs an action of coming into contact with the nail. When the touch signal is output, as shown in step 108, the counter setting section 37a
In this case, the number of counts = 3 is set, and the a signal is emitted. Therefore, the measured coordinate value X of the register 37b obtained by the touch signal passes through the fourth AND gate 39, and becomes the current claw position measurement value Xa.
is temporarily stored as From here on, the operation is repeated up to step 112, and the dispersion is determined.
Repeat up to the set number of times as long as no signal is generated.

When the variation is less than the variation tolerance Δa,
Output from the OK output terminal of the variation determination section 42
The OK signal is applied to one input terminal of the sixth AND gate 44, and the measured coordinate value X from the register 37b is applied to the other input terminal.

Then, as shown in FIG. 3D and step 113 in FIG. 4, the touch sensor 14 is returned to a position sufficiently in front of the claw 4 in the X-axis direction, and further,
As shown in FIG. 3D and step 114 in FIG.
Return it sufficiently to the front of the end face 4a.

Based on the input signal from the sixth AND gate 44, the nail position data processing section 45 controls the touch sensor 14 as shown in step 115 in FIG.
The nail position measurement value Xj is calculated by taking into consideration the amount of travel from the nail position, the diameter of the contact of the touch sensor 14, etc.

Then, the data of the claw position measurement value Xj from the claw position data processing section 45 and the data of the claw position setting value _X0 from the claw position setting value register 47,
The data of the claw position tolerance Δj from the claw position tolerance register 48 is applied to each input terminal of the claw position determining section 46, and the measured claw position value Xj and the claw position are determined as shown in step 116 in FIG. Determine the difference from the set value X ₀ , and if the difference value _is larger than the claw position tolerance Δj, that is, |
An NG signal is output from the NG output terminal, and is applied to the bus line 18, and the process proceeds to step 117 in FIG.
As shown in , a flag indicating that the claw position error is large is raised, and an alarm process is performed, that is, an alarm is sounded.

Furthermore, in the case of |Xj−X ₀ |<Δj, an OK signal is output from the OK output terminal, and it is
8, the CPU 17 gives instructions for the next process to the NC machine tool and performs its operation.

〔Effect of the invention〕

By configuring the structure as described above, the present invention allows the chuck of an NC machine tool to automatically replace a jaw that corresponds to a workpiece with a predetermined jaw that corresponds to the workpiece. It automatically measures and determines whether it is a claw or whether it is in the correct mounting position, and if it is determined to be negative, it issues an alarm to notify you of this. In other words, it is possible to automatically determine if a jaw that does not correspond to the workpiece has been attached to the chuck, or if the jaw has been attached incorrectly or uncertainly, thereby preventing accidents and damage and improving safety. It leads to In addition, since defects in machining of workpieces and deterioration in machining accuracy can be detected before they occur, production efficiency and quality can be expected to improve, and further automation can be promoted.

Furthermore, the approach operation of the touch sensor is
Since the operation is at high speed on or near the spindle axis, interference with the claws is avoided, making it even safer.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an outline of an NC machine tool equipped with a chuck exchange pawl measuring device of the present invention, an automatic pawl exchange and an automatic workpiece exchange device, and Fig. 2 is an NC
A control system diagram of the machine tool and a system diagram of the chuck exchange pawl measuring device, FIG. 3 is a schematic diagram showing the movement of the touch sensor, and FIG. 4 is a flowchart of the operation. 3...chuck, 4...claw, 9...turret, 1
4...Touch sensor, 15...Robotic device,
16...Two-stage feeder, J...Replacement claw pallet,
W...Work, 17...Central processing unit (CPU),
23... Claw measurement program memory, A... Approach motion processing means, B... Variation determination means, C
...Claw position determination means.

Claims (1)

[Scope of Claims] 1. A touch sensor that measures the position of the chuck of a replaced NC machine tool, and approach motion processing means for the touch sensor that causes the touch sensor to perform a measuring operation by operating from or near the spindle axis. and a dispersion determination means for determining dispersion by comparing the difference between the previous measurement value and the current measurement value when the touch sensor is brought into contact with the nail multiple times by the approach motion processing means with a preset tolerance value. a storage means for storing mechanical coordinate values when a touch signal is output by the touch sensor; a claw position setting value storage means for storing coordinate values of a preset claw attachment position; and the variation determination. If the difference between the measured values is larger than the tolerance value according to the determination result of the variation determination means, the measurement operation is repeated; and if the difference between the measurement values is smaller than the tolerance value according to the determination result of the variation determination means, the measurement operation is repeated. Claw position determination means that captures a machine coordinate value when the signal is output as a measured coordinate value, and compares it with the set pawl position set value to determine whether the jaw attachment position is a planned attachment position; A chuck pawl change measuring device for a machine tool, comprising a central control device for controlling each of the above-mentioned means, and capable of automatically and accurately attaching the chuck by confirming the position of the pawl by each of the above-mentioned determining means.