JP2001060105A - Numerical control wire discharge working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a numerical control wire discharge working machine with which an error such as setting forgetting in extra working is prevented, a proper extra working margin or margin to leave can be secured by simple programming and generation of disconnection at the time of the extra working can be suppressed as much as possible. SOLUTION: This numerical control wire discharge working machine is provided with an unwanted side discriminating means 72 for discriminating an unwanted side of an object to be worked in the case of working, an extra working form operating means 75 for operating a form of offset for a prescribed quantity to the unwanted side of the object to be worked discriminated by the unwanted side discriminating part concerning the program commanded working form and an extra working executing means for executing the rough working of the extra working form operated by the extra working form operating means before working the program commanded form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerically controlled wire electric discharge machine, and in particular, has a function of automatically generating a discarded machining shape for a machining shape designated by a program and executing the machining. The present invention relates to a numerically controlled wire electric discharge machine.

[0002]

2. Description of the Related Art In a numerically controlled wire electric discharge machine,
As the work of the workpiece is progressed by the wire electrode, sufficient working accuracy may not be obtained due to deformation due to release of internal (residual) stress of the rolled work material, and therefore, a few mm from the final machined shape. Processing is performed at an offset position (for example, about 2 to 5 mm). This is called disposal processing.

[0003] That is, processing is performed in a shape as shown in the outer side of FIG. 7 or FIG. 8, and the following two methods have been adopted as a method of realizing the processing.

First, there is a method (hereinafter referred to as a first method) for generating a trajectory of discarding processing by using a processing trajectory of a final processing shape by changing an offset amount, and is realized by the following procedure. I was

[0005] 1. Create a machining program that includes the following:

[0006] A final machining shape trajectory is defined.

[0007] An offset number for the first roughing (discarding) is designated.

[0008] An offset number for the second roughing and finishing is designated.

[0009] 2. A correction value (a wire diameter correction value, a processing gap correction value, etc.) corresponding to an offset number for roughing and finishing is specified.

[0010] 3. Specify the correction value (the amount of separation from the final machining shape) corresponding to the offset number for discarding machining.

4. Execute the above machining program.

As shown in FIG. 7, the first processing shape is defined when the final processing shape is defined in an offset form.
Will be used.

In addition, there is a method (hereinafter referred to as a second method) for defining a trajectory of the discarding processing separately from a processing trajectory of a required final processing shape, and has been realized by the following procedure.

1. Create a machining program that includes the following:

[0015] The final machining shape trajectory and machining conditions are defined.

An offset number used for roughing and finishing is specified.

[0017] The trajectory of the discarded processing shape and the processing conditions are defined.

2. A correction value (a wire diameter correction value, a processing gap correction value, etc.) corresponding to an offset number for roughing and finishing is specified.

3. Execute the above machining program.

The second method is used when the discarded shape is to be defined in such a way as to make a cut in some places as shown in FIG. 8 or in a simple form.

[0021]

However, in the above-mentioned first method, although the definition of the discarding trajectory itself is simple, there are the following problems.

The remaining amount of the processing in the discarding processing is important particularly when the punch side is required. Since a shape heavier than the case of processing the final processing shape is left, it is necessary to make the amount sufficient so as not to affect the processing of the final processing shape, but there is no method for specifying this. In addition, a wire diameter correction for processing the final processing shape and a pseudo wire diameter correction for separately performing offset for discarding processing are required.

That is, in the first method described above, based on FIG. 9 which is an example of a program for performing the processing shown in FIG. 7, processing and discarding of the final processed shape as indicated by N007 and N018 It is necessary to determine the processing end point in consideration of the remaining margin of each processing, and as shown in N005, the wire diameter correction number No. for discarding processing. Since it was necessary to define 5 and its correction amount (offset amount from the final machining shape), the program was troublesome and there was a risk of causing an error.

In the above-mentioned second method, although a discarded processing shape can be freely defined, there is a problem that it is necessary to define a processing path for the discarding processing separately from a processing path of the final processing shape.

That is, in the second method described above, specifically referring to FIG. 10 which is an example of a program for performing the machining shown in FIG. Since it is necessary to define the processing trajectories OPRE1 and OPRE2, there is a problem that programming is extremely troublesome.

In the case of discarding in which the time required for processing is to be kept to a minimum, it is desired to suppress the occurrence of disconnection as much as possible.
Disconnection is inevitable to some extent when there is an acute angle portion having the shape as shown in FIG. In such a case, in either of the first method and the second method, since the same locus is processed after reconnection, there is a high possibility that the wire will be broken again at the same position.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to prevent mistakes such as forgetting to make settings, and to carry out appropriate disposal processing allowances and remaining allowances with simple programming. It is to provide a numerically controlled wire electric discharge machine capable of ensuring the above, and suppressing the occurrence of disconnection at the time of discard machining as much as possible.

[0028]

SUMMARY OF THE INVENTION The present invention relates to a method for executing numerical control information in a numerical control device, and an object of the present invention is to provide a numerically controlled wire electric discharge machine which does not require a workpiece at the time of machining. Unnecessary side determining means for determining the side, and a discarding processing shape calculation for calculating a shape obtained by performing a predetermined amount offset to the unnecessary side of the workpiece determined by the unnecessary side determining means with respect to the processing shape designated by the program This is achieved by having a means and a discarding execution means for automatically performing rough machining of the discarded shape calculated by the discarded shape calculation means prior to machining of the shape designated by the program.

Further, according to the present invention, the unnecessary side judging means comprises:
This is more effectively achieved by determining the unnecessary side of the workpiece from the programmed wire diameter correction direction. Further, the present invention is also effectively achieved when the discarded shape calculating means calculates a discarded shape that leaves an amount by which the workpiece does not separate.

In addition, according to the present invention, for a shape in which the discarded shape calculating means has performed a predetermined amount of offset to an unnecessary side of the workpiece, a trajectory for avoiding an acute angle portion of the shape to the unnecessary side is provided. It is also effectively achieved by performing calculations.

Further, according to the present invention, when wire breakage occurs during execution of roughing by the discarding execution means,
A discarding correction shape calculating means for calculating a trajectory for avoiding the disconnection position to the unnecessary side; Is also achieved effectively.

Therefore, according to the numerically controlled wire electric discharge machine of the present invention, it is possible to execute a discarding operation with an adequate discarding allowance and a remaining allowance by simply performing simple programming.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the block diagram of FIG. 3 and a program example of FIG.

The program interpreting section 71 sequentially interprets the machining program, sends a wire diameter correction command such as a command G41 or G42 to the unnecessary side determining section 72, and converts a machining path command such as the command G01, G02 or G03 into an acute angle. The information is sent to the partial determination unit 73 and the discarded shape calculation unit 75.

In the unnecessary side determination section 72, the command G
From the directions of the wire diameter correction commands such as 41 and G42, it is determined whether the discarding should be performed on the machining trajectory on the right or left side with respect to the machining progress direction, and the unnecessary side information is discarded. 75.

The acute angle portion judging section 73 judges the acute angle portion of the machining locus from the machining locus command, and sends the information such as the machining program block to the discard machining shape correction instructing portion 74.

In the discard processing shape correction command unit 74,
Based on information such as a machining program block relating to an acute portion of the machining locus, a rounding R is inserted into an acute portion of the discarded shape, or a disconnection of the discarded shape is performed based on a disconnection position and a disconnection position avoidance command on the machining program. A machining shape correction command for generating a discarding machining locus for avoiding the position on the unnecessary side is transmitted to the discarding machining shape calculation unit 75.

In the discarded machining shape calculation unit 75, the machining trajectory command sent from the program interpretation unit 71, the unnecessary side information sent from the unnecessary side judgment unit 72, and the machining trajectory command sent out from the discarded machining shape correction command unit 74. Based on the discarding processing shape correction command, a discarding processing trajectory is generated and sent to the discarding processing execution command unit 76 and the disconnection shape specifying unit 79 as a processing program.

The discarding execution command unit 76 executes a machining program for machining the discarding trajectory, develops it into the movement amount of each axis, and sends it to the servo control unit 77. In the servo control unit 77, each servo axis (X,
(Y, U, V, etc. axes: not shown).

The disconnection detecting section 78 detects an unexpected disconnection of the wire electrode and sends out the disconnection information to the disconnection shape specifying section 79.

The disconnection shape specification section 79 specifies a disconnection position on the processing program from the processing program of the discarding processing locus and the disconnection information, and discards a disconnection position avoidance command to correct the discarded processing shape to avoid this position. It is sent to the machining shape correction command unit 74.

While taking the machining program of FIG. 4 as an example,
The functions provided by the present invention will be described. N001: Command G120 instructs that there is discard processing. When this command is issued, it is determined that the discard machining is to be performed based on the first machining condition (normally, rough machining condition) interpreted by the program interpreting unit 71, and the command G123 ( It is determined that the discarded machining shape calculation unit 75 generates a discarded machining trajectory based on the shape from when the discarded machining shape input is commanded until the command G122 (discarded shape cut off) is commanded.

N002: Command CNT = 0 is an initial value setting of a variable to be used by sequentially switching the processing conditions from the rough processing conditions.

N003: The vertical guide is moved to the starting hole position of the processing.

N004: Automatic wire connection is performed at the start hole position.

N005: Command processing conditions. (The machining condition number is a value obtained by subtracting the value of the variable CNT from 110.) N006: The discharge power supply is turned on.

N007: Command G123 and thereafter G122
Based on the processing locus shape instructed up to this point, the shape of the abandoned machining is generated in the abandoned machining shape calculation unit 75. L is used to set the uncut amount when performing discarding.
The command R sets the offset amount of the discarded processing shape with respect to the actual processing shape. At this time, the discarding processing offset direction is determined as shown in FIG. 5 based on the wire diameter correction direction. In the case of the command Q0, the discarded machining shape calculation unit 7 outputs the discarded machining shape correction command unit 74 for all of the acute angles determined by the acute angle portion determining unit 73.
5 and performs automatic correction, and if the command is Q1, only the acute corner where the disconnection specified by the disconnection shape specifying unit 79 has occurred is automatically corrected at the acute angle portion (corner R
A correction command is issued to the discarded machining shape calculation unit 75 by the discarded machining shape correction command unit 74 so as to automatically add the data. This means shape correction as shown in FIG. 6 with respect to FIG. In the discarded shape calculation unit 75, the correction direction is determined from the closest command G41 or G42 after the command G123. The discarding processing execution command unit 76 performs the discarding processing based on the processing information from N001 to N012. Then, the program interpreting section 71 interprets the program from step N001 onward, assuming that there was no discarding processing command.

As an example of the means for avoiding the disconnection position to the unnecessary side, it is conceivable to connect from a position half before the offset setting value R at the disconnection point to a position advanced by half the offset setting value R from the disconnection point. . In the middle of a block, the trajectory may not be changed. In this case, the trajectory is not changed, assuming that the disconnection is caused by another factor. (However, the means for avoiding the disconnection position to the unnecessary side is not limited to this means.) In the case where there is no L command, not only L = 0 is considered but also L = 0.
The area (or volume) of the processed work may be automatically calculated, and the remaining margin may be automatically determined.

N008: Perform axis operation (machining operation) while making wire diameter correction effective. Note that DG = VS [1
10-CNT, 108] is the processing condition E (110-C
This is a value indicating machining allowance + discharge gap when machining is performed from NT) to E108. As the wire diameter correction value, this DG value is set to the wire diameter correction number 1 (D1
) Is used. In the discarding process, the offset amount of the discarded shape specified by the command R in the block of step N007 is added to the wire diameter correction value specified in this block.

N009: The subprogram represented by OFGR is called, and the instructions in this subprogram are executed.

N010: Perform axis operation (machining operation) while canceling wire diameter correction.

N011: Command G122 instructs the end of the discarded shape.

N012: The wire electrode is cut.

N013: Increment the counter by one. still,
When the discarding process is being executed by the discarding process execution command unit 76, the counter is not incremented.

N014: If the counter value is 2 or less,
Returning to step N003, the wire electrodes are connected again, and processing is performed under the following processing conditions. If the counter value exceeds 2, processing after the step N014 (not shown) is performed.

As described above, the disposal processing and the final processing as shown in FIG. 2 are achieved.

[0057]

According to the present invention, the rough machining of the discarded shape is automatically performed prior to the machining of the shape designated by the program, so that mistakes such as forgetting to set can be prevented, and the discarded shape has an amount that does not separate the workpiece. Therefore, it is possible to secure a proper allowance for the discarding process, and when a wire disconnection occurs during the discarding process, a trajectory for avoiding the disconnection position is calculated so that recurrence of the disconnection can be prevented.

[Brief description of the drawings]

FIG. 1 is a view showing an acute angle portion of a discarded machining shape in a numerically controlled wire electric discharge machine according to the present invention.

FIG. 2 is a view showing an example of a discarded machining shape in the numerically controlled wire electric discharge machine according to the present invention.

FIG. 3 is a block diagram illustrating a configuration example of a numerically controlled wire electric discharge machine according to the present invention.

FIG. 4 is an example of a machining program including discard machining in the numerically controlled wire electric discharge machine according to the present invention.

FIG. 5 is a diagram showing a discarding machining offset direction of the numerically controlled wire electric discharge machine according to the present invention.

FIG. 6 is a diagram showing a correction shape of an acute angle portion of a discarded machining shape of the numerically controlled wire electric discharge machine according to the present invention.

FIG. 7 is a view showing a first example of a discarded machining shape of a numerically controlled wire electric discharge machine according to the related art.

FIG. 8 is a view showing a second example of a discarded machining shape of the numerically controlled wire electric discharge machine according to the related art.

FIG. 9 is an example of a first machining program including discard machining in a numerically controlled wire electric discharge machine according to a conventional technique.

FIG. 10 is an example of a second machining program including discard machining in a numerically controlled wire electric discharge machine according to a conventional technique.

[Explanation of symbols]

 71 Program interpreting unit 72 Unnecessary side determining unit 73 Sharp part determining unit 74 Discarding shape correction command unit 75 Discarding shape calculation unit 76 Discarding process execution command unit 77 Servo control unit 78 Disconnection detecting unit 79 Disconnection shape specifying unit

Claims (5)

[Claims] In a numerically controlled wire electric discharge machine, an unnecessary side judging means for judging an unnecessary side of a workpiece at the time of machining, and an unnecessary side judging means for a machining shape commanded by a program. Discarding shape calculating means for calculating a shape with a predetermined amount of offset to the unnecessary side of the workpiece, and roughing of the discarding shape calculated by the discarding shape calculating means for machining of the shape commanded by the program. A numerically controlled wire electric discharge machine, comprising: a discarding machining executing means that automatically performs prior machining. 2. The numerically controlled wire electric discharge machine according to claim 1, wherein said unnecessary side determining means determines an unnecessary side of the workpiece from a wire diameter correction direction designated by a program. 3. The numerically controlled wire electric discharge machine according to claim 1, wherein said discarded machining shape calculating means calculates a discarded machining shape that leaves an amount by which the workpiece does not separate. 4. The method according to claim 1, wherein said discarding shape calculating means calculates a locus for avoiding an acute angle portion of said shape to said unnecessary side with respect to a shape having a predetermined amount of offset to an unnecessary side of said workpiece. 2. The numerically controlled wire electric discharge machine according to 1. 5. A discarding correction shape calculating means for calculating a trajectory for avoiding a broken position to the unnecessary side when a wire break occurs during the roughing execution by said discarding processing means, and said discarding correction shape calculation. Discarding process disconnection returning means for performing rough machining of the discarding correction shape calculated by the means,
The numerically controlled wire electric discharge machine according to claim 1, further comprising: