JPH0370242B2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on numerical control (hereinafter simply referred to as NC).
Regarding the sequence return method in machine tools, in particular, a method that allows the tool to accurately return to the interrupted point and continue machining even if machining is interrupted due to tool breakage, tool wear, dimension measurement, etc. during continuous machining with NC machine tools. Regarding.

By the way, the conventional sequence return is to find the machining sequence number that includes the tool position when machining was interrupted, and use the sequence number search function to return the NC program to the position of the sequence number one sequence number before the above machining sequence number. Read into NC memory. Then, by restarting the tool, the tool returns from the retreated position to the command value of the read sequence number, and then the machining sequence executed when machining was interrupted is executed. In other words, as shown in the lathe machining diagram in Fig. 1 and the machining program in Fig. 2, if we consider the case where the workpiece 2 is cut into the final shape P _a -P _b -P _c -P _d ... with the tool 1. , fast forward G00 to point P ₀ in sequence number N001, then sequence number
Point P ₁ at cutting feed G01 (feed rate F) at N002
Then, at sequence number N003, go to point _P2 ... A program is created according to the machining sequence. Therefore, when cutting is performed according to such a machining program, the point P _S
When a problem occurs, the operator interrupts cutting, evacuates tool 1 to a safe evacuation position P _R , and performs necessary operations such as tool replacement and dimension measurement, but the operator attempts to continue machining again. If so, find the sequence number (N007 in this example) that includes the point P _S where machining was interrupted. Using this sequence number search function, the NC reads the machining program up to the previous sequence number (N006 in this example), and restarts the tool 1 from point P _R to point P ₄ . After that, the cutting operation with sequence number N007 is continued.

However, in the above-described sequence return method, idle cutting is performed between the returned point _P4 and the interrupted point _PS , which causes wear on the tool and also causes the tool to move through the area that has already been cut. , so there is a time loss, and the distance (P ₄
−P _S ) is particularly problematic. Also,
In the case of a command program without a sequence number, there is a drawback that it is not possible to return to the sequence. Here, the case where there is no sequence number is typified by a complex cutting cycle/automatic program cutting function, etc., and is a case where the machine has a function of automatically calculating a machining program by utilizing the function of the computer's built-in NC. Taking the machining process shown in Figure 1 as an example, if only the final shape P _a -P _b -P _c ... is programmed as shown in Figure 3, all intermediate cutting paths will be automatically calculated. . Therefore, when cutting is being performed using such a machining program, when machining is interrupted at point _PS , the problem is how to return to that position and continue machining. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sequence return method that does not have the drawbacks mentioned above.

This invention will be explained below.

This invention has an NC function generator that calculates a machining path according to an NC machining program and moves a tool post, and interrupts machining due to dimensional measurement, tool exchange, etc. during continuous NC machining, and controls the tool post. In a sequence return method in which machining is continued by restarting the tool after retracting the tool, a CRT graphic display device capable of displaying the machining path as a machining trajectory is provided, as well as an interruption point save memory means and a state save memory means, When interrupting the machining, a machining interrupt signal is input, and the interrupt point of the machining path is saved in the interrupt point save storage means, and the tool is evacuated to the save position, and the machining path is saved. When a display signal is input, the interruption point saved in the interruption point saving storage means is returned to the NC function generator, and the machining trajectory up to the interruption point is displayed on the CRT graphic display device to approximate the interruption. Locking the tool post by inputting a point search signal, and displaying the machining point resulting from the function generation as a point on the machining trajectory on the CRT graphic display device;
Operating the display point so that it comes to an approximate point near the interruption point, then inputting a sequence return signal, and inputting the approximate point and the state of the NC function generator at that time into the state saving storage means. At the same time, when the tool is moved to the approximate point and a start signal is input, the state saved in the state save storage means is transferred to the NC function generator;
The NC processing is continued from the approximate point.

Next, an example of a device to which this invention method is applied will be described with reference to FIG. 4. The machining program WP from the command register 11 is input to the NC function generator 10, and the machining path (linear/ The circular arc function) PT is input to the servo drive unit 12 via the gate G1, and is also input to the CRT graphic display device 1 via the CRT control unit 13.
4 is now displayed. Further, from the NC function generator 10, gates G2 and G3 are respectively output.
The data is transmitted to the break point save register 15 and the state save register 16 through the gates G4 and G5, respectively.
It is designed to be input to the NC function generator 10. Therefore, gate G1 and NC function generator 1
The interruption approximate point search signal BS is input to gate 0, the machining interruption signal WH is input to gate G2, the sequence return signal SR is input to gate G3, the machining trajectory display signal WT is input to gate G4, and the start signal is input to gate G5.
ST is input respectively, and servo drive unit 1
2 is designed to move the tool rest (tool cutting edge).

In such a configuration, the NC function generator 10
calculates the machining path PT according to the machining program WP from the command register 11, moves the tool rest via the gate G1 and the servo drive unit 12, and displays the machining trajectory on a CRT graphic via the CRT control unit 13. Displayed on the device 14. Therefore, even if machining is interrupted, the machining trajectory up to the interruption point will be
This will be displayed on the CRT graphic display device 14, so that the interruption point can be accurately known. In other words, if the operator interrupts machining when the tool tip of the tool rest is at point P _S in Figure 1, for example, the machining interrupt signal WH causes the interrupt point P _S to be retracted from the interrupt point via gate G2. register 15
At the same time, the cutting edge of the tool is retracted to, for example, point P _R in FIG. Then, when the operator inputs the machining trajectory display signal WT, the interruption point P _S saved in the interruption point saving register 15 is returned to the NC function generator 10 via the gate G4, and the interruption point P _S is The machining trajectory is displayed on the CRT graphic display device 14 via the CRT control unit 13.

Next, the operator interrupts the approximate point search signal BS
When inputting , the gate G1 closes and the movement of the tool post is locked, and the machining path PT consisting of straight lines and circular arcs up to the interruption point Ps displayed on the CRT graphic display device 14 is superimposed on the machining path PT.
Based on the input of the interrupted approximate point search signal BS, the NC function generator 10 displays the trajectory of the function generated as a machining point. The operator then operates the display point so that it comes close to the interruption point _PS (for example, point P _SA on the same trajectory in FIG. 1). When the operator inputs the sequence return signal SR after completing the approximation operation, the approximation point obtained by the approximation operation and the NC function generator 10 at that time are
The prepared state is input to the state save register 16 via gate G3, and the tool cutting edge of the tool rest is moved in rapid traverse to the displayed approximate point (P _SA ). That is, the approximate point is transferred from the state save register 16 to the command register 11, and the NC function generator 10 outputs a machining trajectory from point _PR to the approximate point. The prepared state of the NC function generator 10, which is evacuated by the sequence return signal SR, is the state used in a general NC manual interrupt function, and is controlled from P ₄ to P ₅ in Fig. 1. This shows the state of the NC function generator 10 during the process of P ₄ →P _S
→The cutting process can be continued as shown on page ₅ .

Therefore, when the operator inputs the start signal ST, the status is saved in the status save register 16.
The state of the NC function generator 10 passes through the gate G5.
It is transferred to the NC function generator 10, which allows the cutting process to continue from the approximate point (P _SA ).

As described above, according to the present invention, there are advantages in that the interruption point can be displayed and confirmed, there is no time loss, and there is no wear on the tool.

Particularly, the display of the processing interruption point has the following effects. During machining, the tool often passes through the same commanded position repeatedly. For example, according to FIGS. 1 and 2, the tool 1 passes through the points P1 and P2 twice. For example, if a machining interruption occurs at point P1, if only the position information of point P1 was stored, it would be difficult to know which command sequence to use when returning to the sequence, or which command block in the compound machining cycle function. (blocks that are automatically generated), but the restart point of machining can be specified by the graphic drawing of the machining history according to the present invention, so the command sequence and command block described above can be easily determined. can do. Furthermore, when returning to the sequence, it is necessary to reset all modal command codes to the state immediately before machining was interrupted, and to set the tool in a position suitable for restarting machining. According to the invention,
When the sequence returns, the servo is locked, commands are interpreted and executed at high speed from the beginning of the machining program, and all necessary command codes are memorized, so all modal command codes can be reliably restored to the state immediately before machining was interrupted. In addition, as shown in Fig. 5, the tool trajectory is graphically displayed on the CRT graphic display device 14 at a higher speed than the actual machining command speed, and the machining history before the machining interruption point (N4→N5→N6→N7→ Since the operator is informed of the relay point), the operator can easily set the tool 1 at a position suitable for restarting machining by manual operation or the like. Furthermore, when machining is interrupted, the power may be shut off for safety reasons, and in such cases, it is difficult to distinguish the sequence before machining is interrupted from a machining program consisting of thousands to tens of thousands of sequences. The above-mentioned graphical display makes it possible to easily determine the sequence before processing is interrupted.

Note that although the above-described embodiments have been explained using lathe processing as an example, the present invention can also be applied to the case of processing a tertiary mold having a complex shape.

[Brief explanation of drawings]

FIG. 1 is a machining diagram for explaining conventional and present sequence control, FIG. 2 is a diagram showing an example of a machining program, FIG. 3 is a diagram showing an example of a machining program using the automatic program function, and FIG. FIG. 5 is a block diagram showing an example of a device to which this invention method is applied, and FIG. 5 is a diagram illustrating the effect when this invention method is applied. DESCRIPTION OF SYMBOLS 1...Tool, 2...Workpiece, 10...NC function generator, 11...Command register, 12...Servo drive unit, 13...CRT control unit, 14
...CRT graphic display device, 15...Break point save register, 16...Status save register, G1 to G
5... Gate, BS... Interruption approximate point search signal, WH
...Machining interruption signal, SR...Sequence return signal,
WT...machining trajectory display signal, ST...start signal.

Claims (1)

[Claims] 1 It has an NC function generator that calculates the machining path according to the NC machining program and moves the turret.
In a sequence return method that continues NC machining by restarting after interrupting machining due to dimension measurement, tool exchange, etc. during continuous NC machining and retracting the tool from the tool post, the machining path is displayed as a machining trajectory. In addition to providing a CRT graphic display device that can perform the processing, an interrupt point save memory means and a state save memory means are provided, and a process interrupt signal is inputted when the process is interrupted, and the interrupt point of the process path is determined by the process interrupt signal. The interruption point is saved in the interruption point saving storage means, the tool is saved to the saving position, and the interruption point saved in the interruption point saving storage means is saved in the interruption point saving storage means when the machining trajectory display signal is input.
The process is returned to the NC function generator, the machining trajectory up to the interruption point is displayed on the CRT graphic display device, the interruption approximate point search signal is inputted to lock the tool post, and a function is generated. displaying the resulting machining point as a point on the machining trajectory on the CRT graphic display device, operating the display point so that it comes to an approximate point near the interruption point, and then inputting a sequence return signal; The approximate point and the state of the NC function generator at that time are input into the state saving storage means, and when the tool is moved to the approximate point and a start signal is input, the state is saved in the state saving storage means. transfer the state to the NC function generator;
A sequence return method characterized in that the NC machining is continued from the approximate point.