JPS5926401B2 - Tool position correction method in machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tool position setting method in a numerically controlled lathe.

In recent years, lathes that are numerically controlled are increasingly being used to perform turning operations.

With this numerically controlled lathe, the beginning of machining,
It is important to accurately set the position of the tool tip.

In other words, numerically controlled lathes have a predetermined origin, and when the machining dimensions of the workpiece to be machined are input as a command value, this command value is calculated from the origin to determine how the tool should move. This is because they are instructed to do so.

However, although this tool is attached to a tool post, the position of the tip of the tool with respect to the reference point of the tool post (for example, the center point of the tool post) differs depending on each tool or the method of attachment.

Tool position setting involves accurately setting the position of the tip of the tool in relation to the reference position of the tool rest.

Conventionally, there are various methods for setting the position of the tool.

One is to position the center of the tool post at a predetermined position (
For example, it is specified that the vehicle should be brought to the rear end position)
This method involves determining the tool tip position relative to the center of the tool post, and having the operator readjust the center of the tool post based on this actual measurement.

This method is the most primitive method and it is difficult to guarantee accurate tool positioning.

In addition, as an improvement to the above method, there is a method in which the actual measured value is inputted as a correction value to the instruction processing section of the machine, thereby driving the machine with a value obtained by correcting the correction value from the work instruction value, and a method in which the correction amount is input on a tape. Is there a way to do it?

However, all of the above conventional methods only measure and compensate for the amount of displacement between the tool tip and the center of the tool post, and do not correct the position of the tool tip during actual machining. However, since the workpiece is not fully sized, it has the disadvantage that the finished dimensions of the workpiece cannot be kept within the desired accuracy.

In other words, the tool edge fluctuates slightly due to the condition of the built-up edge during machining, fluctuations in the height of the knife, wrinkles on the edge, deviation of the slide of the knife, etc., and in order to achieve high finishing accuracy. Therefore, it is necessary to perform tool correction that takes into account these variables during machining.

Some examples of these tool corrections are described in Japanese Patent Publication No. 46-42275.

In other words, in this method, the blade is placed on the tool post so that the blade edge position matches the origin position set in the program, then one trial cutting process is performed according to the program, the dimensions of the machined part are measured, and the result is If there is a deviation, that value is input as a correction value to the control unit along with the direction of correction, and subsequent machining is performed accordingly, or
This correction work is designed to be performed automatically.

However, even with this method, in order to automatically perform one step of trial cutting according to a program, the cutting tool must be accurately mounted on the tool rest so that the cutting edge matches the original position.

This is because if the blade is installed in the wrong position, the depth of cut per cut will be too large, resulting in too much cutting force, or the blade will come into contact with the chuck, causing damage to the blade. This is because it occurs.

Therefore, this invention solves the above-mentioned various problems, and it is a numerical value that aims to hybridize a general-purpose machine and an automatic machine by leaving a handle on the feed screw proposed in the previously filed Japanese Patent Application No. 79817-1979. In the tool position setting of a controlled lathe, the tool position setting work in an automatic machine is greatly simplified by performing the tool position setting work manually.

In other words, rather than accurately measuring the position of the cutting edge on the tool post and installing the tool, the tool is installed in the most natural position.
Manually operate this turret to use any tool on the turret.
Test-cut the workpiece, keep the blade stopped at the test-cutting position, measure the finished dimensions of the workpiece after test-cutting, and input this measured value directly into the Y-direction register corresponding to the blade using a digital switch. , thereby storing and displaying the position of the cutting edge of the cutting tool in the Y direction.

In addition, the position of the cutting edge of the tool in the X direction can be determined by manually operating the tool post and moving it until the cutting edge of the tool comes into contact with the processing end surface of the workpiece. The value of the direction register is set to O using the cancel switch, thereby storing and displaying the position of the cutting edge of the cutter relative to the workpiece in the X direction.

This operation for setting the position of the cutting edge is performed in the same way for all the cutting tools on the tool rest.

This will change the position of the cutting edge of all the blades on the tool rest.
The direction is set accurately with the chuck center line as the origin, and the X direction is accurately set with the machining end surface of the workpiece as the origin. This is done by comparing the cutting edge position of any given cutter above with the data file input to the numerical control unit and the numerical value of the work command. It becomes true.

The structure of the present invention will be specifically explained below with reference to embodiments shown in the drawings.

In FIG. 1, 1 is a chuck attached to the main shaft of the lathe, 2 is a workpiece, 3 is a tool rest, and 4a.

4b, 4c, and 4d indicate blades attached to the four corners of the tool rest 3.

The above-mentioned tool rest 3 has a part that rotates around the center, and a base part that supports this part and is movable in the X direction and in the X direction by a drive means such as a combination of a known screw shaft and a nut. The movement in the X direction and the movement in the X direction of this base part are detected by an The detected numerical values are configured so that they are stored and displayed simultaneously in the X and Y direction registers as the amount of movement of the base part in the X and Y directions, regardless of the rotation of the rotating part of the tool post 3. .

The above-mentioned registers are used in the same number as the number of blades attached to the tool rest 3, and the X-direction register of each blade receives its detected value from a single X-direction detector 10, as shown in FIG. The configuration is such that the signals are input all at once using a pulse generator or the like and stored and displayed.

That is, if the tool post 3 moves by +10 mm in the X direction, the +10 movement is transmitted through the X direction detector 10 to the X direction registers 12a, 12b, 12c of each blade.
, 12d, and the value of each X direction register is set to 1 at the same time.
It is configured so that 0mm is added.

The same applies to the X direction, which is shown in FIG.

That is, the Y direction register 13a of each cutter. 13b, 13c
, 13d, detection values are sent all at once from a single Y-direction detector 11.

The numerical control section includes one Y-direction display section and one X-direction display section, and the X-direction register 12a.
, 12b, 12c, 12d and the X direction display section 14
(As shown in the figure, selection switches 15a, 15b, 15c,
They are connected in parallel via 15d.

That is, when the cutter currently in use is the first cutter 4a, the switch 15a is ONL, and the other switches 15
b, 15c.

15d is 0FFL, and the display unit 14 is configured to display the stored numerical value of the first X-direction register 12a.

Also, X direction registers 13a, 13b, 13c.

13d is also a selection switch 16a as shown in FIG.

They are connected in parallel to the Y-direction display section 17 via 16b, 16c, and 16d.

The selection device for the selection switches 15 and 16 is as shown in FIG.
6 is installed, and dogs 7 are installed in different positions on the four sides of the tool rest 3 corresponding to this switch.

That is, it is divided into a surface where two dogs 7 are installed, a surface where no dog 7 is installed, a surface where one dog 7 is installed on the right side, and a surface where one dog 7 is installed on the left end, and both switches 5 and 6 are turned on. 1 of the selection switches 15 and 16 is selected according to four conditions: when , when both are OFF, when only the right switch 6 is ON, and when only the left switch 5 is ON. The configuration is such that one can be selectively turned on.

The numerical control section receives the same input as the display section 14.17, and has a data file that encodes this numerical value and the specifications necessary for driving the normal tool rest 3 in the X and Y directions, which are given separately. and a command processing unit that compares and determines the operation command and the work command and issues an operation signal.

Next, the tool position setting circuit will be explained.

First, as shown in FIG. 7, the tool position setting circuit in the X direction includes selection switches 19a, 19b, and 19c for each register 12a, 12b, 12c, and 12d.

A single cancel switch 18 is provided via 19d.

Selection switches 19a, 19b. 19c and 19d have the same functions as those described above, and only those corresponding to the knife currently in use are turned on.

When the cancel switch 18 is turned on, the selection switch is selected and the value in the corresponding register is set to zero.

The above-mentioned canceling circuit (this is further provided with a canceling correction device 20, and when a new workpiece is mounted on the chuck, this device 20 calculates the number of cancellations of the canceled registers, and calculates the number of cancellations of the other registers that were not canceled). It has the function of adding or subtracting from a numerical value.

That is, before attaching a new workpiece to the chuck and starting machining, the cancel correction device 20 brings the tool to be used for the first time into contact with the end face of the workpiece, and corrects the origin in the X direction all at once (by the same amount). The relative positions of each tool shall not be changed.

To express it concretely, the first tool is now brought into contact with the end face of a new workpiece, and the value in the register 12a for this tool is +10 mm before cancellation, and this stored value is changed by turning on the cancel switch 18. If it is canceled and becomes zero, the other register 1
2b.

This function subtracts 10 mm from the stored numerical values of 12c and 12d, and vice versa (if the stored numerical value of register 12a before cancellation was 110 mm, then if this stored numerical value is canceled and becomes 0, then the other registers 12b
, 12c, and 12d are added by 10mvt.

Next, the tool position setting circuit in the Y direction is as shown in FIG.

This circuit includes each register 13a. 13b, 13c, 13d
The selection switches 21a, 21b, 21c,
The reading circuit 22 and the digital switch 23 for inputting set values are connected in parallel via 21d.

This selection switch has the same function as described above.

Now, when the selection switch 21a is ON and the others are OFF, a predetermined set value is input by the digital switch 23, and the set value is read by the reading circuit 22.
, and only the numerical value stored in the register 13a is changed to the input set value and stored.

Next, the tool position setting procedure of the present invention will be explained.

This type of numerically controlled lathe is used to continuously perform the same turning process on a large number of workpieces of the same shape. First, the tool post 3 is equipped with several types of cutters required for the process. installed only.

Now, the explanation will be given assuming that the number of blades attached is four.

When the work starts, the first workpiece is gripped by the chuck 1 as shown in FIG.

In this state, the positions of the blade edges of the four blades 4a, 4b, 4c, and 4d are all stored in the register.

First, start with 4a. This 4a is placed at an arbitrary position on the workpiece 2 by manually operating the tool rest, and test cutting is performed.

Then, the finished diameter dimension D1 of the workpiece 2 after the test cutting is measured using a micrometer or the like.

This measurement dimension is determined by determining the position of the cutting edge in the Y direction as the diameter position from the center of the chuck, and using this value as the tool position setting value in the Y direction, the circuit shown in Figure 8 is performed while the cutting tool is stopped at the test cutting position. The digital switch 23 stores the information in the register 13a.

Therefore, the register 13a stores Dl.

Next, the starting point of the work using the cutter 4a, for example, as shown in Fig. 1 (here, the tool rest 3 is manually moved so that the cutter 4a hits the right side of the workpiece 2, and the tool rest is stopped at that position. Then, the value stored in the X-direction register 12a (for example, +15 mm) is set to zero by the cancel switch 18 shown in FIG.

As a result, the position of the cutting edge of the first cutting tool 4a is set with respect to the work gripped by the chuck 1.

Next, the tool post 3 is rotated 90 degrees and test cutting is performed on the workpiece with the second cutting tool 4b, the finished dimension of the workpiece after the test cutting is actually measured, and this is input to the register 13b by the digital switch 23 in Fig. 8. Make me remember.

As a result, the register 13b stores the position ζ of the cutting edge of the cutter 4b in the Y direction from the center of the chuck.

Next, the cutter 4b is brought into contact with the right end of the workpiece, and the X-direction cancel switch 18 is used to zero the stored value in the register 12b.

This means that the position of the blade 4b has been set and memorized.

When the positions of the blades 4c and 4d are set in the same way as described above, the relative positions of the cutting edges of the four blades in the X direction and the Y direction are set and stored.

With this, the first workpiece is processed.

That is, as shown in FIG. 8, processing is performed by comparing register values, data files, and work instructions for the cutting tool currently in use in an instruction processing section, and outputting machine operation signals.

Next, when processing a second workpiece with the same tool on the tool post 3, the chuck center, that is, the origin in the Y direction, remains unchanged, and the relative positions of the four tools remain unchanged, so the workpiece It is only necessary to set the tool position in the X direction.

That is, when the second workpiece is gripped by the chuck, the position of the right end of this workpiece does not necessarily match the position of the right end of the first workpiece.

This means that the position of the origin in the X direction changes depending on the attachment state of the work in the third and fourth operations, that is, each time, so the origin in the X direction must be set only in this X direction each time.

To do this, since the relative positions of the four cutters in the X direction remain unchanged, any one of the four cutters is brought into contact with the right end of the workpiece and the cancel switch 18 shown in Fig. 7 is turned on to perform cancellation correction. The device 20 may correct the stored values in the X direction all at once.

As described above, the workpiece can be processed under the same conditions each time.

Also, if one of the cutlery breaks or needs to be replaced during Kaloe, replace only that cutter, use that cutter, manually test cut the workpiece, and check the finished dimensions. The measured value is inputted using the digital switch 23 in Fig. 8, the stored value of the corresponding register is corrected, and the position of the cutter is corrected in the Y direction.Subsequently, the cutter is moved to the right edge of the workpiece Then, the value of the X-direction register corresponding to the cutter may be corrected to zero.

At this time, this is done independently from other registers.

As explained above, this invention uses the chuck center line as the origin of the cutting direction (Y direction), sets the origin of the feed direction (X direction) at an arbitrary position, and controls the amount of movement of the tool rest in the X and Y directions. A plurality of X- and X-direction registers corresponding to the plurality of blades attached to the tool post are stored and displayed all at once as the moving distance from the origin through the respective detectors, and the current position of the tool post is displayed. In a numerically controlled lathe that has a numerical control unit that controls and drives the drive unit in the X and X directions of the tool post by comparing the machining command values with In order to correctly set the position of the cutting edge of each blade by installing it in an arbitrary state without considering it, manually operate the tool post to set the workpiece with the first blade. Perform test cutting, measure the outside diameter of the test-cut portion of the workpiece with the cutter stopped at the test cutting position, input this measured value as is with a digital switch, and display the memorized register in the Y direction for the cutter. By replacing the value with the above measured value, it is set as the current position of the blade in the Y direction from the origin, and to set the position of the blade edge in the X direction of the blade, manually operate the tool post to set the blade position in the Y direction. By bringing the cutting edge of the tool into contact with the machining end surface of the workpiece and pressing the cancel switch while keeping the tool post stopped at the relevant position, the memorized display value of the register in the X direction for the tool is canceled to 0. The position of the cutting edge is set as the current position in the X direction of
Bring the cutting edge of any blade on the tool rest into contact with the machining end surface of the workpiece to cancel the memorized display value of the register in the X direction of the blade to O, and at the same time cancel all other blades on the tool rest. The stored display value of the X-direction register is also corrected all at once by the above cancel amount.Furthermore, when only one of the plurality of knives is replaced with a new one, the above-mentioned cutting edge position is changed only for that knife. This allows you to perform setting operations.

Therefore, even if you do not consider the position of the cutting edge at all when installing the cutting tool on the tool rest, when automatically trial cutting, the cutting edge may hit the chuck, or the depth of cut becomes large and the cutting force is reduced. There will be no problems such as damage to the cutter, tool rest, headstock, etc.

In this way, the attachment and replacement of the cutter on a numerically controlled lathe, which has been extremely troublesome in the past, can be done very easily.

In addition, for position setting, if you input the actual measured value as is without considering the correction value or correction direction all at once, it will be stored in the control unit as the accurate position of the cutting edge, including the fluctuation factors during machining. The subsequent processing is performed with high precision based on this.

This process requires only measuring the dimensions of the machined part and inputting the values as they are into the numerical control unit and register, eliminating the need for complex judgment work and allowing accurate tool positioning without the need for specialized knowledge. It has the advantage of being configurable.

[Brief explanation of the drawing]

Figure 1 is an explanatory plan view of the main parts of the lathe, Figures 2 and 3.
The figure shows the register circuit in the X direction and the Y direction, Figures 4 and 5.
The figure is a circuit diagram showing the connection between the X-direction and Y-direction registers and the display section, FIG. 6 is an explanatory diagram of the drive mechanism of the selection switch, and FIG. 7 is a schematic diagram of the tool correction circuit of the X-direction register.
FIG. 8 is a flow sheet diagram of the 5-machiyama positive circuit of the X-direction register. 1...Chuck, 2...Work, 2a
...... Test cutting section, 3... Turret, 4a
, 4b, 4c, 4d... cutlery, 10...
・X direction detector, 11...Y direction detector, 12
a, 12b, 12c, 12d=X direction register, 13a, 13b, 13c, 13d...Y
Direction register.

Claims (1)

[Claims] 1 Set the chuck center line as the origin of the cutting direction (Y direction),
The origin of the feed direction (X direction) is set at an arbitrary position, and the amount of movement of the tool post in the X and Y directions is measured as the moving distance from the origin through the respective detectors. Numerical values that are stored and displayed simultaneously in multiple X- and Y-direction registers corresponding to each cutter tool, and are used to control and drive the X- and Y-direction drive parts of the tool rest by comparing the current position of the tool rest and the processing command value. A numerically controlled lathe with a control unit (in this case, when newly installing multiple blades on the tool post, the blade positions are not considered at all, that is, they are installed in an arbitrary state,
To correctly set the position of the cutting edge of each blade, in order to set the position of the blade edge in the Y direction, manually operate the tool rest, test cut the workpiece with the first blade, and stop the blade at the test cutting position. By measuring the outer diameter of the test-cut portion of the workpiece, inputting this measured value as is with a digital switch, and replacing the memorized display value of the register in the Y direction for the blade with the above measured value, to set the current position from the origin in the Y direction of the tool, and to set the cutting edge position of the tool in the By pressing the cancel switch while the tool post is stopped at the relevant position, the memory display value of the register in the X direction for the relevant blade is canceled to 0, thereby setting it as the current position in the X direction of the relevant blade, and the second The cutting edge positions of subsequent blades are set in the same manner as above, and when replacing a workpiece, the cutting edge of any blade on the tool post is brought into contact with the machining end surface of the workpiece, and the blade position is set in the X direction of the blade. The stored display value of the register in the register is canceled to 0, and at the same time, the stored display value of the register in the X direction of all the other blades on the tool post is also corrected by the above cancel amount, and furthermore, A tool position setting method for a numerically controlled lathe, characterized in that when only one of the cutters is replaced with a new one, the above-described cutting edge position setting operation is performed only for that cutter.