JP2734301B2 - Wire electric discharge machining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electric discharge machining method, and more particularly to a method of shortening the time required for resuming machining when a wire breaks during machining and resuming machining even when a workpiece is deformed. Wire electric discharge machining method.

[0002]

2. Description of the Related Art FIG. 8 is a configuration diagram showing an example of a conventional wire electric discharge machine. In this wire electric discharge machine 800, 81 is a wire. The wire 81 is wound around a wire bobbin 82A on the wire supply side, and penetrates the work W through a turn pulley 82a. The wire 81 that has penetrated the work W is further wound around a winding wire bobbin 82B via a turn pulley 82b. Here, a voltage is applied to the workpiece W and the wire 81 by the electric power source 81a for electric discharge machining, and the machining is performed while the machining fluid 81b is supplied to the machining portion. 84 is a control device. 8
Reference numeral 5 denotes a motor power supply, which drives a servo motor 85a in accordance with a command from the control device 84, and supplies an XY table 85b,
The guide 85c is moved. Reference numeral 83 denotes a rotary encoder attached in conjunction with the wire bobbin 82A on the wire supply side. The signal from the rotary encoder 83 is sent to the control device 84.

FIG. 9 is a process diagram showing a wire disconnection returning process 900 of the wire electric discharge machine 800. Reference numeral 91 denotes a wire disconnection detection step. As shown in FIGS. 10A and 10B, when the wire 81 breaks during the processing of the work W, the rotary encoder 83 detects the break based on a signal change. Reference numeral 92 denotes a disconnection position storage step. In FIG. 10B, the control device 84 has a built-in memory 84a.
The breaking position coordinates E of the wire 81 are stored in the.

[0004] Reference numeral 93 denotes a moving step of returning to the start hole from the breaking position of the wire 81. As shown in FIG. 10C, when the work W is placed on, for example, the XY table 85, the XY table 85 returns to the processing start position (start hole S). 94 is an automatic wire supply step. As shown in FIG. 10D, the wire 81 is automatically penetrated through the start hole S and stretched.

Reference numeral 95 denotes a process return step. As shown in (e) of FIG. 10, according to the machining shape program programmed before the start of machining, the process returns along the machined path K to the disconnection position coordinates E stored in the disconnection position storage step 92. Reference numeral 96 denotes a processing restart step. As shown in FIG. 10F, a certain distance before the disconnection position coordinates E,
The traveling of the wire 81 is started, and the machining fluid 81b is supplied to resume machining.

[0006]

In the wire disconnection returning process 900 of the conventional wire electric discharge machine 800, when the machining shape is long or complicated, the process returns from the start hole where the machining is started to the wire breaking position. This takes a long time, so that there is a problem that it takes a long time to resume machining. Further, when the internal stress of the workpiece W is released by the processing and deformed as shown in FIG. 11, there is a problem that the work cannot be returned to the disconnection position from the start hole where the processing is started, and the processing cannot be resumed. Therefore, an object of the present invention is to
It is an object of the present invention to provide a wire electric discharge machining method capable of shortening a machining return time when a disconnection occurs during machining and avoiding that machining cannot be restarted.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a wire electric discharge machining method for generating a discharge in a minute gap between a wire electrode and a workpiece and cutting the workpiece. The unnecessary side of the workpiece is specified and the start hole to be added is specified, the specified additional start hole is provided, and when the wire is broken, the closest start hole is searched by searching the processing path from the position and searching for the start hole. A wire electric discharge machining method characterized by restarting machining from a hole.

In the above configuration, the designation of the additional start hole specifies, for example, a position where the start hole is provided. In addition, for example, an interval at which a start hole is provided is specified. Also, for example, the number of start holes to be provided is specified.

[0009]

According to the wire electric discharge machining method of the present invention, an operator designates an additional start hole when creating a program. Then, at the time of the disconnection, the processing is resumed from the nearest start hole by tracing the processing path from the disconnection position. Therefore, for example, if a start hole is added near the position of the processed shape where wire breakage is likely to occur,
At the time of disconnection, it is possible to return from the start hole to the disconnection position in a short time, and it is possible to shorten the time until processing is resumed.
In addition, since the influence of the deformation is minimized, it is easy to avoid that the processing cannot be restarted.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. It should be noted that the present invention is not limited by this. FIG. 1 is a configuration diagram showing a wire electric discharge machine for implementing the wire electric discharge machining method of the present invention. In this wire electric discharge machine 100, 1 is a wire.
The wire 1 is wound around a wire bobbin 2A on the wire supply side, and penetrates the work W via a turn pulley 2a. The wire 1 that has penetrated the work W is further wound around a winding wire bobbin 2B via a turn pulley 2b. Here, a voltage is applied to the workpiece W and the wire 1 by a power source 1a for electric discharge machining, and
It is processed while b is supplied. 4 is a control device.
Reference numeral 5 denotes a motor power supply, which drives a servo motor 5a in accordance with a command from the control device 4 to move an XY table 5b and a guide 5c. Reference numeral 3 denotes a rotary encoder attached in conjunction with the wire bobbin 2A on the wire supply side. The signal from the rotary encoder 3 is sent to the control device 4.

First Embodiment FIG. 2 is a process diagram showing a wire disconnection returning process 200 according to a first embodiment of the present invention. Reference numeral 20 denotes a machining shape program creation step. Reference numeral 21 denotes a shape unnecessary side designation step. The unnecessary side of the workpiece with respect to the machining path is designated (WF in FIG. 3). 22 is a start hole processing position designation step. Specify the position to create a new start hole. For example, the position S1 is designated as shown in FIG. Note that S0a is an original start hole. 23 is a start hole processing step. For example, as shown in FIG. 3A, an additional start hole S1a is machined on the unnecessary side of the start hole machining position S1. In this case, for example, when the automatic enlargement processing using the circular interpolation and the offset function is used, it is not necessary to remove the scrap, and the automation is easy.

Reference numeral 91 denotes a wire disconnection detecting step. FIG.
As shown in (a) and (b), when the wire 1 breaks during the processing of the work W, the rotary encoder 3 detects the break based on a signal change. Reference numeral 92 denotes a disconnection position storage step. In FIG. 3B, the control device 4 stores the breaking position coordinates E1 of the wire 1 in a built-in memory 4a.

Reference numeral 24 denotes a start hole search step.
From the start hole created in the machining shape program, the closest start hole is searched by going back the machining path from the disconnection position coordinates E1 stored in the disconnection position storage step 92. In the case of FIG. 3B, the start hole closest to the disconnection position coordinate E1 is the start hole S1a.

Reference numeral 93 denotes a moving step of returning to the start hole S1a from the breaking position coordinate E1 of the wire 1 to the machining path as shown in FIG. 3C. 94
Is an automatic wire supply step. As shown in FIG. 3D, the wire 1 is automatically passed through the start hole S1a and stretched. Reference numeral 95 denotes a processing return step. As shown in FIG. 3E, the process returns along the machining path K1 to the disconnection position coordinates E1 stored in the disconnection position storage step 92.
Reference numeral 96 denotes a processing restart step. As shown in FIG. 3 (f), the wire 1 is started to travel a certain distance before the disconnection position coordinates E1, and the machining fluid 1b is supplied to resume machining.

According to the wire disconnection returning step 200 described above, the start hole closest to the disconnection position of the wire 1 is searched and the processing is restarted, so that the time required for restarting the processing is reduced. Further, even when the internal stress of the work is released by the processing and is deformed as shown in FIG. 11, the influence can be minimized, so that the processing can be restarted.

Second Embodiment FIG. 4 is a process diagram showing a wire disconnection recovery process 400 according to a second embodiment of the present invention. Reference numeral 20 denotes a machining shape program creation step. Reference numeral 21 denotes a shape unnecessary side designation step. The unnecessary side of the workpiece with respect to the machining path is designated (WF in FIG. 5). Reference numeral 41 denotes a step for specifying a distance between start hole processing positions. Specify the processing path length of the start hole to be added. For example, as shown in FIG.
The machining path length h from the original start hole S0a is designated. 23 is a start hole processing step. For example,
As shown in FIG. 5A, a start hole S3a is machined on the shape unnecessary side of the position S3 of the designated machining path length h. Similarly, a start hole is machined on a shape unnecessary side at a position for each machining path length h.

Reference numeral 91 denotes a wire disconnection detecting step. FIG.
As shown in (a) and (b), when the wire 1 breaks during the processing of the work W, the rotary encoder 3 detects the break based on a signal change. Reference numeral 92 denotes a disconnection position storage step. In FIG. 5B, the control device 4 stores the breaking position coordinates E2 of the wire 1 in a built-in memory 4a.

Reference numeral 24 denotes a start hole search step.
From the start hole created in the machining shape program, the closest start hole is searched by going back the machining path from the disconnection position coordinates E2 stored in the disconnection position storage step 92. In the case of FIG. 5B, the start hole closest to the disconnection position coordinate E2 is the start hole S3a.

Step 93 is a step of moving the wire 1 back to the start hole S3a from the cutting position coordinate E2 of the wire 1, as shown in FIG. 5C. 94
Is an automatic wire supply step. As shown in FIG. 5D, the wire 1 is automatically penetrated into the start hole S3a and stretched. Reference numeral 95 denotes a processing return step. As shown in FIG. 5E, the process returns along the machining path K2 to the disconnection position coordinates E2 stored in the disconnection position storage step 92.
Reference numeral 96 denotes a processing restart step. As shown in FIG. 5F, the wire 1 is started to travel a certain distance before the disconnection position coordinates E2, the machining fluid 1b is supplied, and machining is resumed.

According to the wire disconnection recovery step 400 described above, the start hole closest to the disconnection position of the wire 1 is searched and the processing is restarted, so that the time required for restarting the processing is shortened. Further, even when the internal stress of the work is released by the processing and is deformed as shown in FIG. 11, the influence can be minimized, so that the processing can be restarted.

Third Embodiment FIG. 4 is a process diagram showing a wire disconnection returning process 600 according to a third embodiment of the present invention. Reference numeral 20 denotes a machining shape program creation step. Reference numeral 21 denotes a shape unnecessary side designation step. The unnecessary side of the workpiece with respect to the machining path is designated (WF in FIG. 7). Reference numeral 61 denotes a start hole processing frequency designation step. The number n of start hole processing (that is, the number n of start holes to be added) is specified. 2
3 is a start hole processing step. For example, as shown in FIG. 7A, a start hole S5a is machined on a shape unnecessary side at a position S5 at a distance L / n obtained by equally dividing the entire machining circumference L of the machining shape at a specified number n. I do. Similarly, a start hole is formed on the unnecessary side at a position for each distance L / n.

Reference numeral 91 denotes a wire disconnection detecting step. FIG.
As shown in (a) and (b), when the wire 1 breaks during the processing of the work W, the rotary encoder 3 detects the break based on a signal change. Reference numeral 92 denotes a disconnection position storage step. In FIG. 7B, the control device 4 stores the breaking position coordinates E3 of the wire 1 in the built-in memory 4a.

24 is a start hole search step.
From the start hole created in the machining shape program, the nearest start hole is searched by going back the machining path from the disconnection position coordinates E3 stored in the disconnection position storage step 92. In the case of FIG. 7B, the start hole closest to the disconnection position coordinates E3 is the start hole S5a.

As shown in FIG. 7 (c), reference numeral 93 denotes a movement step of returning to the start hole S5a from the breaking position coordinate E3 of the wire 1 to the machining path. 94
Is an automatic wire supply step. As shown in FIG. 7D, the wire 1 is automatically passed through the start hole S5a and stretched. Reference numeral 95 denotes a processing return step. As shown in FIG. 7E, the process returns along the machining path K3 to the disconnection position coordinates E3 stored in the disconnection position storage step 92.
Reference numeral 96 denotes a processing restart step. As shown in FIG. 7 (f), the wire 1 is positioned a fixed distance before the disconnection position coordinates E3.
, And the machining fluid 1b is supplied to resume machining.

According to the wire disconnection returning step 600 described above, the start hole closest to the disconnection position of the wire 1 is searched and the processing is restarted, so that the time required for restarting the processing is shortened. Further, even when the internal stress of the work is released by the processing and is deformed as shown in FIG. 11, the influence can be minimized, so that the processing can be restarted.

[0026]

According to the wire electric discharge machining method of the present invention, the time for resuming machining at the time of disconnection can be shortened, and machining can be resumed even if deformation occurs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a wire electric discharge machine for performing a wire electric discharge method according to the present invention.

FIG. 2 is a process diagram showing a wire disconnection returning process according to a first embodiment of the wire electric discharge machining method of the present invention.

FIG. 3 is an explanatory diagram showing an operation of a wire disconnection return step of FIG. 2;

FIG. 4 is a process diagram showing a wire disconnection returning process according to a second embodiment of the wire electric discharge machining method of the present invention.

FIG. 5 is an explanatory diagram showing an operation of a wire disconnection return step of FIG. 4;

FIG. 6 is a process diagram showing a wire disconnection returning process according to a third embodiment of the wire electric discharge machining method of the present invention.

FIG. 7 is an explanatory diagram showing an operation in a wire disconnection return step of FIG. 6;

FIG. 8 is a configuration diagram illustrating an example of a conventional wire electric discharge machine.

FIG. 9 is a process diagram showing an example of a wire disconnection recovery process according to a conventional wire electric discharge machining method.

FIG. 10 is an explanatory diagram illustrating an operation of a wire disconnection returning step of FIG. 9;

FIG. 11 is an explanatory diagram showing a state in which the internal stress of the work W has been released by processing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 wire electric discharge machine 1 wire 4 control device 200 wire disconnection return process 20 machining shape program creation process 21 shape unnecessary side designation process 22 start hole machining position designation process 23 start hole machining process 24 start hole search process 400 wire disconnection return process 41 Process for specifying the distance between start hole processing positions 600 Wire disconnection recovery process 61 Process for specifying the number of start hole processing W Work

Claims (4)

(57) [Claims] In a wire electric discharge machining method for generating a discharge in a minute gap between a wire electrode and a workpiece and cutting the workpiece, an unnecessary side of the workpiece with respect to a machining path is designated when a program is created. And specify the start hole to be added,
A wire electric discharge machining method comprising: providing the specified additional start hole, searching for a closest start hole by tracing a machining path from the position when the wire is disconnected, and resuming machining from the start hole. 2. The wire electric discharge machining method according to claim 1, wherein a position where an additional start hole is provided is specified, and an additional start hole is provided at the specified position. 3. The wire electric discharge machining method according to claim 1, wherein an interval at which an additional start hole is provided is specified, and an additional start hole is provided at the specified interval. 4. The wire electric discharge machining method according to claim 1, wherein the number of start holes to be added is specified,
Providing a specified number of additional start holes.