Wire electric discharge machining device, wire electric discharge machining method, control program, and wire electric discharge machining system

Abstract

The wire electric discharge machining device (100) includes a machining program storage unit (50) that stores a machining program in which commands for wire electric discharge machining of a workpiece are written, a machining-related information acquisition unit (11) that acquires machining-related information, which is information relating to the content of the wire electric discharge machining, from a user, a machining program conversion unit (12) that converts the machining program based on the machining-related information acquired by the machining-related information acquisition unit, and a machining control unit (13) that executes a converted program, which is the machining program converted by the machining program conversion unit, to control the wire electric discharge machining.

Description

[Technical Field]

[0001] The present disclosure relates to a wire electric discharge machining apparatus, a wire electric discharge machining method, a control program, and a wire electric discharge machining system that machine a workpiece according to a machining program. [Background technology]

[0002] In wire electrical discharge machining (EDM) machines, machining conditions are important factors that determine their performance. The machining conditions are generally stored in advance in the control device of the wire electrical discharge machining machine by the manufacturer for each setup state, which is the setting condition for the wire electrical discharge machining machine and the workpiece. Setup states include, for example, the workpiece thickness, workpiece material, wire material, wire diameter, and the distance between the upper and lower nozzles. Furthermore, machining conditions include, for example, the machining voltage, wire tension, and machining fluid pressure.

[0003] Even for the same wire EDM machine and setup state, the machining conditions vary depending on the desired machining speed and finish accuracy, resulting in hundreds of possible machining condition patterns. The user selects machining conditions from the machining conditions provided by the manufacturer, i.e., the machining conditions stored in the control device, to suit the workpiece setup state, desired machining speed, and finish accuracy. The selected machining conditions are written into an NC (Numerical Control) program, which is the machining program, and the wire EDM machine performs machining in accordance with the NC program.

[0004] When describing machining conditions in an NC program, it is common to use one of the following methods (1) to (4).

[0005] (1) The CAM (Computer Aided Manufacturing) operator selects the machining conditions to be used from a machining condition table such as a booklet, and edits the NC program to write command codes that specify the machining conditions. (2) The CAM operator searches for machining conditions from a machining condition database connected to a PC (Personal Computer) running the CAM software, and uses the CAM software's functions to write command codes that specify the machining conditions in the NC program. (3) The operator of the wire electric discharge machining device selects the machining conditions to be used from a machining condition table such as a booklet, and edits the NC program to write a command code that specifies the machining conditions. (4) The operator of the wire electric discharge machining device searches for machining conditions from a machining condition database connected to the wire electric discharge machining device, and writes command codes specifying the machining conditions into the NC program using the functions of the wire electric discharge machining device.

[0006] In the cases of (1) and (2), the operator who creates the NC program describing the machining conditions is different from the operator who actually operates the wire EDM machine. In these cases, the CAM operator who creates the NC program does not know the setup state when machining will actually be performed, so he or she may select machining conditions for a setup state that differs from the actual machining, which may result in machining errors.

[0007] To address this problem, Patent Document 1 describes a technology in which a CAM operator creates an NC program that describes multiple machining conditions corresponding to multiple setup states that are expected to actually be possible, and the wire electric discharge machining device detects the actual setup state and performs machining under the machining conditions that correspond to the detected setup state. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5872118 Summary of the Invention [Problem to be solved by the invention]

[0009] Wire EDM often requires subsequent processes such as polishing, and in consideration of these subsequent processes, CAM operators may set different shape accuracy and surface roughness values ​​for wire EDM than those specified in the drawings used during the work. In this case, the NC program must be rewritten or extensively edited. However, the technology described in Patent Document 1 does not take this issue into consideration and is unable to solve it.

[0010] The present disclosure has been made in consideration of the above, and aims to provide a wire electric discharge machining device that can convert a machining program into appropriate content to match the actual machining content and machine a workpiece. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems and achieve the object, the wire electric discharge machining apparatus according to the present disclosure is characterized by comprising a machining program storage unit that stores a machining program in which instructions for wire electric discharge machining of a workpiece are written; a machining-related information acquisition unit that acquires machining-related information, which is information relating to the contents of the wire electric discharge machining, from a user; a machining program conversion unit that converts the machining program based on the machining-related information acquired by the machining-related information acquisition unit; and a machining control unit that executes a converted program, which is the machining program converted by the machining program conversion unit, to control the wire electric discharge machining. [Effects of the Invention]

[0012] The wire electric discharge machining apparatus according to the present disclosure has the advantage of being able to convert a machining program into appropriate content in accordance with the actual machining content and machine a workpiece. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a configuration example of a wire electric discharge machining apparatus according to a first embodiment; [Figure 2] A diagram showing an example of a wire electric discharge machining process. [Figure 3]1 is a flowchart showing an example of the operation of a wire electric discharge machining apparatus; [Figure 4] FIG. 10 is a diagram showing an example of a menu screen for a user to input machining specifications to a wire electric discharge machining device. [Figure 5] FIG. 10 is a diagram showing another example of a menu screen for a user to input machining specifications to a wire electric discharge machining apparatus. [Figure 6] FIG. 10 is a diagram showing an example of a process analysis result obtained by analyzing a machining program. [Figure 7] FIG. 10 is a diagram for explaining an example of an operation in which a machining program conversion unit adds a machining trajectory to a machining program; [Figure 8] FIG. 1 is a diagram showing an example of hardware for implementing a control unit of a wire electric discharge machining apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wire electric discharge machining apparatus, a wire electric discharge machining method, a control program, and a wire electric discharge machining system according to embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.

[0015] Embodiment 1 1 is a diagram showing an example of the configuration of a wire electric discharge machining apparatus 100 according to the first embodiment. The wire electric discharge machining apparatus 100 includes a control unit 10, an electric discharge machining unit 20, a display unit 30, an input unit 40, and a machining program storage unit 50.

[0016] The control unit 10 includes a machining-related information acquisition unit 11, a machining program conversion unit 12, and a machining control unit 13, and controls an electric discharge machining unit 20 that performs machining on a workpiece, which is a workpiece to be machined.

[0017] The machining-related information acquiring unit 11 acquires various pieces of information relating to the details of wire electric discharge machining from a user such as an operator of the wire electric discharge machining apparatus 100. Specifically, the machining-related information acquiring unit 11 displays a menu screen for accepting input of information on the display unit 30, and accepts information input by the user of the wire electric discharge machining apparatus 100.

[0018] The machining program conversion unit 12 converts the machining program stored in the machining program storage unit 50 based on the machining-related information, which is information acquired by the machining-related information acquisition unit 11. Specifically, the machining program conversion unit 12 changes descriptions related to the machining content among descriptions included in the machining program based on the machining-related information. In the following description, the machining program converted by the machining program conversion unit 12 may be referred to as the converted program.

[0019] The machining control unit 13 controls the electric discharge machining unit 20 in accordance with the converted program created by the machining program conversion unit 12 to machine the workpiece.

[0020] The electric discharge machining unit 20 machines the workpiece by applying a voltage between the workpiece and a wire electrode (not shown) to cause discharge in accordance with instructions from the machining control unit 13. The electric discharge machining unit 20 also improves the surface roughness and shape accuracy of the workpiece by performing machining multiple times on a specific section while changing the distance between the workpiece and the wire electrode and the electrical energy.

[0021] The display unit 30 is configured with a display device such as a liquid crystal panel, and displays a menu screen for the user to input various information, a screen showing the operating status of the wire electric discharge machining apparatus 100, and the like.

[0022] The input unit 40 is configured with an input device such as a keyboard, and accepts information input operations by the user.

[0023] The machining program storage unit 50 is configured with a storage device such as a hard disk, and stores a machining program, which is an NC program that describes the details of wire electric discharge machining to be performed on a workpiece.

[0024] Here, the machining steps of wire electric discharge machining by the wire electric discharge machining apparatus 100 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the machining steps of wire electric discharge machining.

[0025] The wire electric discharge machining shown in Figure 2 is a process for creating a mold, and consists of steps 1 and 2.

[0026] Process 1 is the process of creating a part called the die of the metal mold, and process 2 is the process of creating a part called the punch of the metal mold. The die is a part that receives the material pushed into it by the punch and cuts it out into a specific shape, while the punch is a part that cuts out a shape by pushing it into the material. In process 2, two processes, the 1st and 2nd, are carried out.

[0027] Fig. 3 is a flowchart showing an example of the operation of the wire electric discharge machining apparatus 100. The operation of the wire electric discharge machining apparatus 100 to machine a workpiece will be described below in accordance with the flowchart shown in Fig. 3. In the wire electric discharge machining apparatus 100, the control unit 10 executes the processing of steps S11 to S15 shown in Fig. 3 to control the electric discharge machining unit 20, and the electric discharge machining unit 20 machines the workpiece. In this embodiment, the description will be given assuming that the wire electric discharge machining apparatus 100 performs the machining example shown in Fig. 2. That is, the description will be given assuming that the machining program storage unit 50 of the wire electric discharge machining apparatus 100 stores a machining program in which command codes for performing machining in step 1 and step 2 shown in Fig. 2 are written.

[0028] As shown in FIG. 3, the control unit 10 of the wire electric discharge machining device 100 first accepts settings of machining specifications and machining targets (step S11). The settings of machining specifications and machining targets are accepted by the machining-related information acquisition unit 11. The machining specifications and machining targets are examples of machining-related information. The machining-related information may include information other than the machining specifications and machining targets. The machining-related information acquisition unit 11, for example, displays a menu screen shown in FIG. 4 on the display unit 30 and prompts the user to input the machining specifications. The user inputs the machining specifications via the input unit 40.

[0029] Fig. 4 is a diagram showing an example of a menu screen for a user to input machining specifications to the wire electric discharge machining apparatus 100. As shown in Fig. 4, the machining-related information acquisition unit 11 accepts input of each item such as wire diameter, wire material, workpiece material, and workpiece thickness as the input of machining specifications.

[0030] Furthermore, when accepting the setting of the processing target, the processing-related information acquisition unit 11 displays a menu screen on the display unit 30 for the user to input the processing target, and accepts the input of the target accuracy and target surface roughness as the processing target. The target accuracy is a target value for the shape accuracy of the workpiece obtained by processing the work. The target surface roughness is a target value for the roughness of the surface of the workpiece. The processing-related information acquisition unit 11 may accept the input of the processing target and the input of the processing specifications on the same menu screen.

[0031] Among the items included in the machining specifications, the machining-related information acquisition unit 11 may automatically set the wire diameter and wire material by utilizing a function for detecting the diameter and material of the wire attached to the electric discharge machining unit 20. Similarly, if automatic detection of the thickness of the workpiece or the like is possible, the machining-related information acquisition unit 11 may automatically set items that can be automatically detected. FIG. 5 shows an example of a menu screen that the machining-related information acquisition unit 11 displays on the display unit 30 in this case. FIG. 5 is a diagram showing another example of a menu screen that allows the user to input machining specifications to the wire electric discharge machining apparatus 100.

[0032] The control unit 10 then reads out the machining program (step S12) and analyzes the steps (step S13). These processes are executed by the machining program conversion unit 12. The machining program conversion unit 12 reads out the machining program from the machining program storage unit 50, analyzes the read out machining program, and detects the portions that describe the machining of steps 1 and 2 in FIG. 2.

[0033] In step S13, the machining program conversion unit 12 generates a process analysis result, for example, as shown in FIG. 6, based on the descriptions related to the machining of process 1 and process 2 detected by analyzing the machining program. FIG. 6 is a diagram showing an example of the process analysis result obtained by analyzing the machining program. As shown in FIG. 6, the machining program conversion unit 12 extracts, for each machining process, a start point, which is the coordinate value of the starting point of the machining, an end point, which is the coordinate value of the end point of the machining, a machining condition number indicating one of multiple machining conditions prepared in advance, an offset, which is the distance between the workpiece and the wire electrode, and a machining speed from the machining program, and generates a process analysis result. The process analysis result only needs to satisfy the sufficient conditions for converting the machining program; it is not necessary to acquire all of the information shown in FIG. 6 for all processes. For example, for a certain process, if the number of machining operations described in the machining program is the same as the number of machining operations required to achieve the machining target (target accuracy, target surface roughness) set by the user in step S11, information on the start and end points of this process is not necessary.

[0034] Specifically, in analyzing the machining program, the machining program conversion unit 12 first determines which machining iteration the machining conditions described in the machining program correspond to (which machining iteration of the same process they correspond to). The machining iteration may be determined by registering information about the machining iteration in a machining condition database provided outside the wire electric discharge machining device 100 and checking this information, or by writing a code indicating the machining iteration in the machining program and using this code to determine which machining iteration. The machining program conversion unit 12 then determines the start and end points of the machining that correspond to each machining iteration. The start and end points may be determined from the trajectory commanded by the command code described in the machining program, or may be determined from a machining start code or a dedicated code embedded in the machining program. Finally, the machining program conversion unit 12 determines the machining offset and machining speed that correspond to each machining iteration.

[0035] The control unit 10 then converts the machining program (step S14). Specifically, the machining program conversion unit 12 converts descriptions related to the machining content from among descriptions included in the machining program read in step S12 to generate a converted program. The machining program conversion unit 12 converts the portions of the machining program that are described for steps 1 and 2 in FIG. 2 based on the machining-related information acquired by the machining-related information acquisition unit 11 in step S11 and the process analysis results obtained by executing step S13. Specifically, the machining program conversion unit 12 replaces the machining conditions, offset, and machining speed described in the machining program with the machining conditions, offset, and machining speed included in the machining-related information. Note that if a machining condition number indicating one of the pre-prepared machining conditions is described in the machining program, the machining program conversion unit 12 replaces the machining condition number described in the machining program with the machining condition number of the machining condition included in the machining-related information. If some or all of the machining conditions, offsets, and machining speeds included in the machining-related information are the same as the machining conditions, offsets, and machining speeds included in the process analysis results, the machining program conversion unit 12 does not need to perform replacement in the parts where the description contents are the same.

[0036] Furthermore, if the number of machining operations described in the machining program (hereinafter referred to as the first number of machining operations) differs from the number of machining operations included in the machining-related information acquired by the machining-related information acquisition unit 11 in step S11 (hereinafter referred to as the second number of machining operations), the machining program conversion unit 12 adds or deletes a machining trajectory that indicates the path along which the wire electrode moves during machining. Specifically, if the second number of machining operations is greater than the first number of machining operations, the machining program conversion unit 12 adds a machining trajectory, and if the second number of machining operations is less than the first number of machining operations, the machining program conversion unit 12 deletes the machining trajectory. A specific example of adding a machining trajectory will be described below.

[0037] 7 is a diagram for explaining an example of the operation of the machining program conversion unit 21 to add a machining trajectory to the machining program. Here, the conversion method shown in FIG. 7, that is, the method of converting the machining program so as to perform the third machining, will be explained.

[0038] 7, the machining program conversion unit 12 adds a code for instructing the machining path for the third machining (3rd machining) to the machining program. Also, the machining program conversion unit 12 changes the code for instructing the machining path for the cut-off machining in the machining program.

[0039] The code for commanding the machining path for the third machining may be added by using the code for commanding the machining path for the first machining (1st machining) in which the machining direction is the same. That is, the machining program conversion unit 12 may change a part of the code for commanding the machining path for the first machining (1st machining) to create code for commanding the machining path corresponding to the shape of the third machining, and add this to the machining program. As another addition method, the machining program conversion unit 12 may change a part of the code for commanding the machining path for the second machining (2nd machining) to create code for commanding the machining path in the opposite direction to the second machining and corresponding to the shape of the third machining, and add this to the machining program.

[0040] Furthermore, when changing the code that commands the machining path for cut-off machining, the machining program conversion unit 12 swaps the start point and end point of the cut-off machining. As another method of change, the machining program conversion unit 12 may create code that commands the machining path for the fourth machining and add it to the machining program, and further create code that performs empty feeding without performing the fourth machining and add it to the machining program. Note that if the increase in the number of machining cycles is an even number, there is no need to change the code that commands the machining path for cut-off machining.

[0041] When the number of cutting operations is reduced, i.e., when the cutting path is reduced, the machining program conversion unit 12 deletes unnecessary code from the machining program and, if necessary, swaps the start and end points of the cut-off machining. For example, when the number of cutting operations is reduced from three to two, the machining program conversion unit 12 deletes the code commanding the cutting path for the third cutting operation from the machining program and further modifies the code commanding the cutting path for the cut-off machining to swap the start and end points of the cutting path. Note that, if the number of cutting operations reduced is an even number, there is no need to change the code commanding the cutting path for the cut-off machining. Alternatively, the machining program conversion unit 12 may add a command code to the machining program to execute blank feed of the corresponding cutting path without deleting the code commanding the unnecessary cutting path. In this case, there is no need to change the code commanding the cutting path for the cut-off machining, and the original code can be used as is.

[0042] 3, after converting the machining program in step S14, the control unit 10 executes the converted machining program (step S15). In step S15, the machining control unit 13 executes the converted machining program. Specifically, the machining control unit 13 controls the electric discharge machining unit 20 in accordance with commands written in the converted machining program.

[0043] The order of the above-described steps S11 to S13 may be partially reversed as long as they are completed before starting step S14. For example, step S11 may be executed after steps S12 and S13, or steps S12 and S13 and step S11 may be executed in parallel.

[0044] As described above, when the wire electric discharge machining apparatus 100 receives input of machining-related information including machining specifications and machining targets from a user, it converts the description of the machining content of the pre-stored machining program based on the machining-related information, and executes the converted machining program to perform wire electric discharge machining. The wire electric discharge machining apparatus 100 makes it possible to convert the machining program into appropriate content in accordance with the actual machining content and to machine a workpiece.

[0045] Next, the hardware that realizes the control unit 10 of the wire electric discharge machining apparatus 100 will be described.

[0046] Fig. 8 is a diagram showing an example of hardware that realizes the control unit 10 of the wire electric discharge machining apparatus 100. The control unit 10 of the wire electric discharge machining apparatus 100 is realized by, for example, a control circuit 90 including a processor 91 and a memory 92 shown in Fig. 8. Examples of the processor 91 include a CPU (Central Processing Unit, also referred to as a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP (Digital Signal Processor)) or a system LSI (Large Scale Integration). Examples of the memory 92 include a RAM (Random Access Memory) and a ROM (Read Only Memory).

[0047] The control unit 10 of the wire electric discharge machining apparatus 100, i.e., the machining-related information acquisition unit 11, the machining program conversion unit 12, and the machining control unit 13, are realized by the processor 91 executing control programs for operating these units. The control programs for operating the machining-related information acquisition unit 11, the machining program conversion unit 12, and the machining control unit 13 are stored in advance in the memory 92. The processor 91 operates as the machining-related information acquisition unit 11, the machining program conversion unit 12, and the machining control unit 13 by reading and executing the control programs from the memory 92.

[0048] The memory 92 stores the control programs executed by the processor 91, and is also used as a temporary memory when each part of the control unit 10 executes various processes.

[0049] Furthermore, although the above control program is assumed to be stored in advance in memory 92, this is not limiting. The above control program may be provided to the user in a state written on a recording medium such as a CD (Compact Disc)-ROM or a DVD (Digital Versatile Disc)-ROM, and the user may install the program into memory 92. The above control program may also be provided to the user via a network such as the Internet.

[0050] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or portions of the configuration may be omitted or modified without departing from the spirit of the present invention. For example, components other than the electric discharge machining unit 20 of the wire electric discharge machining apparatus 100 described above may be realized by other devices. For example, a wire electric discharge machining system may be configured including a wire electric discharge machine equipped with the electric discharge machining unit 20 and a control device equipped with the control unit 10, display unit 30, input unit 40, and machining program storage unit 50. [Explanation of symbols]

[0051] 10 control unit, 11 machining-related information acquisition unit, 12 machining program conversion unit, 13 machining control unit, 20 electric discharge machining unit, 30 display unit, 40 input unit, 50 machining program storage unit, 100 wire electric discharge machining device.

Claims

1. a machining program storage unit that stores a machining program in which commands for wire electric discharge machining of a workpiece are written; a machining-related information acquisition unit that acquires machining-related information, which is information about the details of the wire electric discharge machining, from a user; a machining program conversion unit that converts the machining program based on the machining-related information acquired by the machining-related information acquisition unit; a machining control unit that executes a converted program, which is the machining program converted by the machining program conversion unit, and controls the wire electric discharge machining; A wire electric discharge machining apparatus comprising:

2. The machining-related information includes machining specifications and machining targets of the wire electric discharge machining.

2. The wire electric discharge machining apparatus according to claim 1.

3. The machining program conversion unit rewrites a description included in the machining program that is related to the machining content of the wire electric discharge machining into a content indicated by the machining-related information.

2. The wire electric discharge machining apparatus according to claim 1.

4. The machining program conversion unit rewrites the description of the machining content for the specific section of the machining program so that the number of times of machining to be performed for the specific section included in the machining-related information is the same as the number of times of machining to be performed for the specific section described in the machining program.

4. The wire electric discharge machining apparatus according to claim 1, wherein the wire electric discharge machining apparatus is a wire electric discharge machining apparatus.

5. When the machining program conversion unit performs rewriting on the machining program to increase the number of times of machining performed on the specific section, the machining program conversion unit performs the rewriting by using an existing description of machining content for the specific section included in the machining program.

5. The wire electric discharge machining apparatus according to claim 4.

6. 1. A wire electric discharge machining method executed by a wire electric discharge machining apparatus having a machining program storage unit that stores a machining program in which commands for wire electric discharge machining of a workpiece are written, comprising: a machining-related information acquisition step in which a control unit of the wire electric discharge machining apparatus acquires machining-related information, which is information regarding the content of the wire electric discharge machining, from a user; a machining program conversion step in which the control unit converts the machining program based on the machining-related information acquired in the machining-related information acquisition step; a machining control step in which the control unit executes a converted program, which is the machining program converted in the machining program conversion step, to control the wire electric discharge machining; A wire electric discharge machining method comprising:

7. A control program for controlling an operation of a wire electric discharge machining device having a machining program storage unit that stores a machining program in which commands for wire electric discharge machining of a workpiece are written, a machining-related information acquisition step of acquiring machining-related information, which is information regarding the content of the wire electric discharge machining, from a user; a machining program conversion step of converting the machining program based on the machining-related information acquired in the machining-related information acquisition step; a machining control step of executing a converted program, which is the machining program converted in the machining program conversion step, to control the wire electric discharge machining; a control circuit constituting the wire electric discharge machining apparatus to execute the above steps; A control program comprising:

8. a wire electric discharge machine for wire electric discharge machining of a workpiece; a control device for controlling the wire electric discharge machine; Equipped with The control device a machining program storage unit that stores a machining program in which commands for wire electric discharge machining of a workpiece are written; a machining-related information acquisition unit that acquires machining-related information, which is information about the details of the wire electric discharge machining, from a user; a machining program conversion unit that converts the machining program based on the machining-related information acquired by the machining-related information acquisition unit; a machining control unit that controls the wire electric discharge machine by executing a converted program that is the machining program converted by the machining program conversion unit; A wire electric discharge machining system comprising:

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