JPS58132442A - Method of controlling return of set-aside tool on numerical-controlled lathe - Google Patents

Abstract

PURPOSE:To make a return program, by detecting the beginning position, middle position and end position of setting-aside of a tool and storing these positions in a memory and by performing rectilinear interpolation on the stored positions in the opposite direction to the setting-aside at the time of the return of the tool. CONSTITUTION:When the chipping of a cutting edge 6a at a point P1 is detected, the working person applies a machining stoppage instruction to a main control section 9 to stop the execution of a machining program PRO and moves a tool 6 to a point P2 in a manual mode so that the tool does not interfere with a workpiece 2. The working person thereafter moves the tool 6 to points P3, P4, P5 in that order so that these positions are linked with each other by imaginary straight lines. When the cutting edge 6a is stopped in each of the positions P2- P5, a switch 21 is pressed down to store the position. To return the tool 6, rectilinear interpolation is effected on the positions P5-P1 to make a return program and put it in the machining program to return the tool to the position of starting of setting-aside.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a numerically controlled lathe in which, when the tool is retracted from an arbitrary point during cutting to a machining point, the tool is returned to the retraction start point along the exact same path as the retraction path. The present invention relates to a method for controlling the return of an evacuation tool.

If chipping occurs on the cutting edge during internal machining on a numerically controlled lathe, the tool should be temporarily evacuated from the cutting position to an evacuation point such as the machine origin, the cutting edge replaced, and then the tool should be retracted again. It is necessary to return to the point and restart machining.

Conventionally, as a control method for returning the tool from the retraction point to the retraction start point, a method was known in which the two points, the retraction point and the retraction start point, were simply linearly interpolated. In the case of internal diameter machining, etc., when moving the tool to the retraction start point inside the workpiece, the tool and workpiece may interfere, resulting in tool breakage, damage to the workpiece, etc. There was also a problem in terms of operator safety, as the risk of this occurring was unclear. Therefore, in such cases, the operator must manually return the tool to the withdrawal starting point, but manual return not only takes time, but also requires a high degree of skill to accurately determine the position of the cutting edge. It was a difficult task.

In order to eliminate the above-mentioned drawbacks, the present invention provides a method for controlling the return of a retracted tool in a numerically controlled lathe, which allows the return of the tool to the retraction start point automatically and safely without interference between the workpiece and the tool. The purpose is to provide

That is, the present invention provides a position detecting means for detecting the position of the cutting edge and a position memory, and detects the positions of the retraction start point, intermediate point, and retraction point during retraction, and records them in the position memory. When returning, create a return program that linearly interpolates each point in the position memory from the save point to the save start point, in the opposite direction to the save time, and further insert the return program into the addition program in the program memory. , the blade edge is configured to return from the retraction point to the retraction start point by the return program.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 is a schematic plan view showing an example of a numerically controlled lathe to which the present invention is applied, and FIG. 2 is a block diagram of a control portion of the numerically controlled lathe shown in FIG.

As shown in FIG. 1, the numerically controlled lathe 1 has a chuck 5 capable of holding and fixing a workpiece 2 along a main shaft 3 and a tool rest 7 equipped with a tool 6. The drive motor 16 (to be described later)
17 so that it can be freely moved and driven. In addition, the lathe l has a main control section 9, as shown in FIG.
Program memory containing 1O1 spindle drive part 12
A main spindle control section 13, a feed axis control section 15, and an interrupt program control section 11 are connected. Control part 1
5 has a tool rest 77! - Drive motors 16 and 17 that drive in the directions of arrows A, B, C, and D are connected, respectively, and transducers 19 and 20 that constitute position detection means together with a counter 22 that will be described later are connected to the motors 16 and 17. I'm in the middle of the day. The transducers 19 and 20 have a push button switch 2.
1 connected counter 22 is connected, and the above-mentioned interrupt program control section 11 is connected to the counter 22 via a position memory 23.

Since the numerically controlled lathe l has the above configuration, when machining the workpiece 2 held by the chuck 5, the machine program PR stored in the program memory 10 is used.
According to O, the spindle control unit 13 rotationally drives the spindle drive motor 12 to rotate the workpiece 2 around the spindle 3 at a predetermined speed, and the feed axis control unit 15 drives the drive motors 16 and 17 to rotate the workpiece 2 at a predetermined speed. 7. Therefore, point the tool 6 at arrow A.

Processing is performed by moving in directions B, C, and D.

Therefore, as shown in FIG.
If chipping occurs on the cutting edge 6a at point PI while performing internal diameter machining of the workpiece 2 according to In response to the command to interrupt the operation, the main control section 9 causes each control section 13.15 to immediately stop execution of the addition program PR,0. Next, the operator turns the lathe into manual mode that does not depend on the Niprogram PRO.
The tool 6, which has entered the interior 2a of the workpiece 2, is moved in the direction of the arrow while being careful not to interfere with the tool 6 and the workpiece 2, with the cutting edge 6a touching the point Pl. to move the cutting edge 6a to point P2, and further,
It is moved in the B direction to point P3, and then sequentially moved to points P4 and P5 in a manner that connects each point in a straight line. This work is performed by the operator instructing the feed axis control unit 15 from the keyboard 8 via the main control unit 9 about the movement direction and lid of each drive motor 16, 17, but the drive motor!
6. Every time 17 rotates by a certain angle, transducer 19
．． From 20 onwards, the position pulse cp1. cP2 is counter 22
counter 22 outputs it to motor 16 . Count in the positive and negative directions taking into account the rotation direction of i7. Therefore, the pulse CPI of the counter 22, the integration ff of CP2
By looking at i TP 1 , '1'' P 2 ,
The tool rest 7, therefore, the tool length Lx from the tool rest center 7a to the tool rest 7.

The coordinates of the cutting edge 6a of the tool 6 mounted at the position Lz can be easily calculated. Therefore, the operator
A is moved a predetermined distance in a predetermined direction, and the push button switch 21 is pressed each time the cutting edge 6a stops from point P1 to points p2, p3, p4, and P5. Then, the integrated values TPI, TP2 of the counter 22 at that time are output to the position memory 23, and the memory 23 stores the points PI, P2 . P3. P4゜P
The integrated values TPI and TP2 of each point up to 5 are recorded as corresponding to the blade edge position. When the cutting edge 6a reaches point P5, which is the retraction point, and the operator replaces the cutting edge 6a and commands a return to point P1, which is the retraction starting point, via the keyboard 8, the main control section 9 causes the interrupt program control section 1 to
1 is driven, the control unit 11 selects the points pl, P2 . P3. P4. P5 integrated value TPI,
The coordinates of the cutting edge 6a at each point are calculated and determined by reading each of TP2, and then P4. P3.
P2. A return program RPRO is created which linearly interpolates each point to PL in a manner that is reverse to the time of saving, and is inserted into the step being executed at the time of starting saving of the program program PRO in the program memory 10. Next, the main control section 9 controls the main shaft control section 13. The feed axis control unit 15 is commanded to execute the cannibal program PRO, and the cannibal program PRO is executed from the interrupted return program RPRO.
The control unit 15 first moves the tool 6 from point P5 to P4. P3, P
2. The motors 16 and 17 are appropriately controlled to move to PL. When the execution of the return program RP 0 is completed and the cutting edge 6a returns to the point PL, each control unit 13.15
Execution starts from the predetermined step of the cannibal program PRO that was being performed at the time the evacuation operation was started, and machining is restarted. Note that when returning, the cutting edge 6a follows a completely opposite path to that when retracting in the manual mode, so the tool 6 and the workpiece 2 do not interfere with each other.

Although the above-mentioned embodiment describes the case where the present invention is applied to machining the inner diameter of the workpiece 2, the present invention is not limited to inner diameter machining, but can also be applied to other machining such as tile machining on the outer diameter. Of course, it can also be applied.

As explained above, according to the present invention, points P2, P3, which are intermediate points passed by the cutting edge 6a during retraction. P4 and
The positions of point P1, which is the evacuation start point, and point P5, which is the evacuation point, are recorded in the position memory 23 by integration 11iTPl, TP2, etc., and when returning, move points P4, P3, P2 from point P5 to point P1 in reverse. I created a return program RP which performs linear interpolation and inserted it into the program PRO, so that the return of the cutting edge 6a to the retraction start point can be automatically performed without interference between the tool 6 and the workpiece (object 2). This eliminates the need to manually check the position of the cutting edge during return as in the past, and it is possible to provide a reliable and safe return control method for a retracted tool.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an example of a numerically controlled lathe to which the present invention is applied, and FIG. 2 is a block diagram of a control portion of the numerically controlled lathe shown in FIG. ■・・・・・・・・・・・・Numerical control lathe 6・・・・・・
......Tool 6a...Blade tip 10...Program memory 19.20...
...Position detection means (transducer) 22...
...Position detection means (counter) 23...
...Position memory Pl...Evacuation start point (point) p2. p3.
p4・・・Midway point (point) P5・・・・・・・・・
Evacuation point (point) PL0...Canada program RPRO...
・・・Return bpgram

Claims (1)

[Claims] It has a program memory that stores a carnivorous program, and performs machining operations by moving the tool according to the machine program, and when retracting the tool, manually moves the cutting edge of the tool from the retracting start point to the intermediate point to the retracting point. In a numerically controlled lathe that performs retraction operation by linearly moving between points, a position detection means and a position memory are provided to detect the position of the cutting edge, and the retraction start point, intermediate point, and evacuation point during retraction can be determined. Each position is detected and recorded in the position memory, and when the tool is returned, a return program is created that linearly interpolates each point in the position memory from the retreat point to the retreat start point in the opposite direction to the retreat. A method for controlling the return of a retractable tool in a numerically controlled lathe, further comprising inserting the return program into a cutting program of the program memory, and returning the cutting edge from the retract point to the retract start point using the return program.