JPH05158516A - Numerical controller having thread cutting control function - Google Patents

Abstract

PURPOSE:To improve the work efficiency by measuring a thread part by a touch sensor attached to a movable part of a working machine, and calculating a phase shift amount. CONSTITUTION:The tip part of a touch sensor 102 is moved to a point for coming into contact with a screw thread of a work in the parallel direction (Z axis) against a main spindle rotation shaft, and a measuring position detecting circuit 13 inputs a contact signal SG from the touch sensor 102 through a sensor signal input circuit 12. Subsequently, the tip part of the touch sensor 102 is moved to a point for coming into contact with the screw thread of the work in the parallel direction (Z axis) against the main spindle rotation shaft in the reverse direction, and the measuring position detecting circuit 13 inputs its contact signal SG in the same way. On the other hand, the measuring position detecting circuit 13 always reads in position information SI from a position detecting device 16, stores a position of a working machine 10 at the time when the contact signal SG of each point is inputted, and also, sends it out to a phase shift calculating circuit 14. The phase shift calculating circuit 14 derives a middle point of each point by position information SH, sets a distance between two points as a phase shift amount and sends it out to a phase shift arithmetic circuit 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a threading control function capable of automatically correcting a threading start point when a workpiece having a roughened threaded portion is mounted on a processing machine and the threaded portion is reworked. The present invention relates to a numerical control device.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional numerical control device having a thread cutting control function. First, the reading circuit 1 reads and analyzes the NC program SA created on an NC tape or the like by an operator or the like and input from the operation panel. Then, as shown in FIG. 5, the cutting edge of the thread cutting tool 101 is moved to a predetermined thread cutting start point P in the processing machine 10.
0, and then an integer multiple n of the thread pitch P from the threading start point P0 in the direction parallel to the spindle rotation axis (Z axis).
It moves to the point P1 which is separated by the distance (1 = P × n) in the fast feed. Then, the processing of the NC program SA is temporarily stopped. The operator operates the pulse handle to move the blade edge of the thread cutting tool 101 from the point P1 in the direction parallel to the main shaft rotation axis (Z axis) to align it with the rough groove of the workpiece 100. When the position of the cutting edge of the thread cutting tool 101 at this time is point P2, the amount of movement from the point P1 to the point P2 is stored in the phase shift amount storage circuit 8 as the phase shift amount δi.

After that, when the processing of the NC program SA is restored, first, the cutting edge of the thread cutting tool 101 is rapidly moved to the thread cutting start point P0 in the processing machine 10 and the spindle on which the work 100 is mounted is rotated. Read circuit 1
Reads the thread cutting command instructed to the NC program SA, the thread cutting cycle command SB is sent to the thread cutting cycle circuit 2 and the feed command F indicating the feed amount is sent.
Is sent to the delay time correction circuit 6, the DIFF calculation circuit 7, and the phase shift calculation circuit 9. On the other hand, the REV pulse counter 4 measures the rotation of the spindle and sends it to the spindle rotation speed calculation circuit 5 as pulse data rp. The spindle rotation speed calculation circuit 5 determines the spindle rotation speed R per minute based on the pulse data rp.
To the delay time correction circuit 6 and the DIFF calculation circuit 7
To send to. The delay time correction circuit 6 performs a calculation process according to the formula 1 by the delay time ΔT from the detection of the spindle rotational speed R, the feed command F and the pulse data rp to the completion of the calculation to obtain the calculation delay time correction amount St, and the phase shift calculation circuit 9 To send to.

## EQU1 ## St = (R / 60) × F × ΔT

On the other hand, the DIFF calculation circuit 7 uses Equation 2 based on the spindle rotational speed R, the feed command F and the speed deviation Kv of the servo system.
Then, the servo system delay amount Sd is calculated according to the above, and the servo system delay amount Sd is sent to the phase shift calculation circuit 9.

## EQU2 ## Sd = {(R / 60) × F} / Kv Then, the phase shift calculation circuit 9 calculates the calculation delay time correction amount St.
And the sum of the servo system delay amount Sd and the phase shift amount δi read from the phase shift amount storage circuit 8 divided by the feed command F (see Formula 3) is sent to the thread cutting cycle circuit 2 as the phase shift correction amount δt. ..

## EQU3 ## Residue of δt = (δi + St + Sd) / F The thread cutting cycle circuit 2 corrects the thread cutting start point PO by the phase shift correction amount δt and sends the corrected thread cutting cycle command SC to the function generating circuit 3. The function generating circuit 3 outputs the function S according to the corrected thread cutting cycle command SC.
E is generated to control the thread cutting operation of the processing machine 10.

FIG. 6 is a diagram showing an example of the locus of the cutting edge of the thread cutting tool corrected by the above-described conventional numerical control device having a thread cutting control function. If not corrected, the cutting edge of the thread cutting tool 101 first moves from the thread cutting start point P10 to a point P20 in a direction (X axis) perpendicular to the spindle rotation axis, but if corrected, it changes from the point P20 to the spindle rotation axis. On the other hand, it moves to the point P11 approaching the work side by the phase shift correction amount δt in the parallel direction (Z axis). Next, the cutting edge of the thread cutting tool 101 moves from a point P11 to a point P12 while performing thread cutting at a predetermined pitch, and a point P13 separated from the work 100 in a direction (X axis) perpendicular to the spindle rotation axis from the point P12. After moving to, the process returns to the thread cutting start point P10. Since the starting point of thread cutting at the time of reworking can be corrected in this way, the threaded part can be reworked in the same phase as that at the time of first rough working (Japanese Patent Laid-Open No. 62-62-62).
99020 publication).

[0006]

In the above-described conventional numerical control device having a thread cutting control function, the operator visually checks the thread cutting tool while operating the pulse handle each time the thread part of the rough-worked work is reworked. Since the amount of phase shift is measured by adjusting the blade edge to the thread groove of the rough-processed screw portion, there is a problem that the operator's burden is large and the measurement precision of the amount of phase shift varies.
The present invention has been made under the circumstances as described above,
An object of the present invention is to provide a numerical control device having a thread cutting control function capable of automatically performing highly accurate measurement of a phase shift amount and automatically correcting a thread cutting start point during rework. ..

[0007]

SUMMARY OF THE INVENTION According to the present invention, when a workpiece having a roughened screw portion is mounted on a processing machine and the screw portion is reprocessed, the phase shift of the thread groove of the screw portion occurs at the time of mounting. Amount, the servo system delay amount of the processing machine, and a numerical control device having a function of controlling the thread cutting by correcting the thread cutting start point with a phase shift correction amount calculated from the calculation delay time of the numerical control device, The object of the present invention is achieved by providing a calculating unit that measures the threaded portion with a touch sensor attached to a movable portion of the processing machine to calculate the phase shift amount.

[0008]

In the present invention, the phase shift amount is automatically calculated by bringing the tip of the touch sensor into contact with the screw thread and detecting the position of the tip of the touch sensor at that time.
A highly accurate phase shift amount can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an example of a numerical controller according to the present invention in correspondence with FIG. 4, and the same components are designated by the same reference numerals and their description is omitted. The reading circuit 1 sends to the sensor control circuit 11 a touch sensor operation command SF including information on the operation direction and position necessary for the operation of the touch sensor 102 attached to the movable part of the processing machine 10 instructed by the NC program SA. To do. The sensor control circuit 11 analyzes the touch sensor operation command SF, creates a measurement control command SJ, and sends it to the function generation circuit 3. The function generation circuit 3 generates a function according to the measurement control command SJ, controls the operation of the control motor 15, and controls the position of the touch sensor 102.
That is, as shown in FIG. 2, first, the tip portion of the touch sensor 102 is moved from the thread cutting start point P0 in the direction parallel to the spindle rotation axis (Z axis) at a distance n which is an integer multiple of the screw pitch P (l =
The workpiece 10 is moved in the direction (X axis) perpendicular to the spindle rotation axis from the point P1.
It moves to the point P30 which went to 0. Then, as shown in FIG. 3, the touch sensor 102 moved to the point P30.
Is moved to a point P31 in contact with the thread of the work 100 in a direction parallel to the main shaft rotation axis (Z axis), and at the same time as the contact, a contact signal SG from the touch sensor 102 is generated.
To the measurement position detection circuit 1 via the sensor signal input circuit 12
3 inputs. Then, the tip end portion of the touch sensor 102 moved to the point P31 is moved in the opposite direction to the point P32 which comes into contact with the thread of the work 100 in the direction parallel to the spindle rotation axis (Z axis), and the contact is made. At the same time, the contact signal SG from the touch sensor 102 is sent to the sensor signal input circuit 12
The measurement position detection circuit 13 inputs via the.

On the other hand, the measurement position detection circuit 13 constantly reads the position information SI from the position detection device 16, and the point P31
And the processing machine 1 when the contact signal SG of the point P32 is input
The position of 0 is stored and the position information SH thereof is sent to the phase shift calculation circuit 14. The phase shift calculation circuit 14 uses the position information SH to calculate the point P as shown in FIG.
A point P33, which is the midpoint between 31 and the point P32, is obtained, the distance between the point P33 and the point P30 is calculated as the phase shift amount δi, and the calculated value is sent to the phase shift calculation circuit 9.

## EQU00004 ## .delta.i = {(P31 + P32) / 2} -P30 In addition, in FIG.
If the workpiece 100 comes into contact when moving from 1 to the point P30, the tip of the touch sensor 102 is temporarily returned to the point P1 and is parallel to the main shaft rotation axis (Z axis).
After the parallel movement by the preset movement amount, the movement may be made toward the work 100 in the direction (X axis) perpendicular to the main shaft rotation axis. The preset movement amount and movement direction are specified in the touch sensor operation command.

[0011]

As described above, according to the numerical controller having the thread cutting control function of the present invention, the highly accurate measurement of the phase shift amount is automatically performed to automatically correct the thread cutting start point at the time of reworking. Therefore, it is possible to reduce the labor of the operator, improve the work efficiency, and perform highly accurate thread cutting.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a numerical control device having a thread cutting control function of the present invention.

FIG. 2 is a first diagram for explaining an example of a method of measuring a phase shift amount by the device of the present invention.

FIG. 3 is a second diagram for explaining an example of a method of measuring a phase shift amount by the device of the present invention.

FIG. 4 is a block diagram showing an example of a conventional numerical control device having a thread cutting control function.

FIG. 5 is a diagram for explaining an example of a method of measuring a phase shift amount by a conventional device.

FIG. 6 is a diagram showing an example of a trajectory of a tool after a phase shift amount is corrected in a conventional device.

[Explanation of symbols]

 11 sensor control circuit 12 sensor signal input circuit 13 measurement position calculation circuit 14 phase shift calculation circuit 15 control motor 16 position detection device 102 touch sensor

Claims (1)

[Claims] 1. When a workpiece having rough threaded parts is mounted on a processing machine and the threaded parts are reprocessed, the amount of phase shift of the thread groove of the threaded parts generated at the time of mounting and the servo of the processing machine. In a numerical control device having a function of correcting a thread cutting start point with a phase shift correction amount calculated from a system delay amount and a calculation delay time of a numerical control device, and controlling the thread cutting, the screw part is provided as a movable part of the processing machine. A numerical control device having a thread cutting control function, comprising a calculating means for measuring the amount of phase shift by measuring with a mounted touch sensor.