WO2019239481A1

WO2019239481A1 - Wire electric discharge machine and straightness-calculating method

Info

Publication number: WO2019239481A1
Application number: PCT/JP2018/022403
Authority: WO
Inventors: 智昭 ▲高▼田; 中川　孝幸; 大介関本
Original assignee: 三菱電機株式会社
Priority date: 2018-06-12
Filing date: 2018-06-12
Publication date: 2019-12-19
Also published as: DE112018007560B4; DE112018007560T5; CN112262011A; JPWO2019239481A1; CN112262011B; JP6526364B1

Abstract

A wire electric discharge machine (100) for machining a workpiece (W) by applying a voltage between a wire electrode (1) and the workpiece (W) is characterized in being provided with: a wire-adjusting unit (102) for changing the position of the wire electrode (1) with respect to the workpiece (W); a contact-detecting unit (103) for detecting whether or not the wire electrode (1) and the workpiece (W) are in contact; and a straightness-measuring unit (106) for determining the straightness (ΔD) of the machining surface of the workpiece (W) on the basis of the position of the wire electrode (1) with respect to the workpiece (W) when contact between the wire electrode (1) and the workpiece (W) is detected by the contact-detecting unit (103).

Description

Wire electric discharge machine and straightness calculation method

The present invention relates to a wire electric discharge machine and a straightness calculation method for processing a workpiece by applying a voltage between a wire electrode and the workpiece.

A wire electrical discharge machine uses electrical energy generated by an electrical discharge phenomenon that occurs when a wire electrode is brought close to a workpiece while a machining voltage is applied between the wire electrode and the workpiece. Process things. Since the machining accuracy varies depending on the machining conditions such as the machining voltage, the machining conditions are determined so as to obtain the desired machining accuracy by evaluating the machining accuracy. One of the criteria for evaluating machining accuracy is the straightness of the machined surface. Straightness refers to the amount of deviation from the correct position of the machined surface. As a method for measuring the straightness, a method using a micrometer can be mentioned. When using a micrometer, it is necessary to remove the object to be processed from the wire electric discharge machine. However, since evaluation of machining accuracy is often performed repeatedly, it is desirable that the straightness of the machined surface can be measured while the workpiece is attached to the wire electric discharge machine.

Patent Document 1 discloses a wire electric discharge machine equipped with a measuring device using a stylus. According to the wire electric discharge machine disclosed in Patent Document 1, the straightness of the processed surface can be measured by bringing the tip of the stylus into contact with the processed surface while the workpiece is attached to the wire electric discharge machine. it can.

JP 60-85829 A

However, according to the above-described conventional technique, in order to measure the straightness of the machining surface, a measurement-specific stylus that is not used for electric discharge machining is used. Therefore, the wire electric discharge machine has a stylus and a stylus. It is necessary to provide a measuring instrument including a driving device that moves the motor. For this reason, when using a stylus, the size and cost of the apparatus increase, and when the processing surface to be measured is in the slit, the thickness of the stylus is larger than the width of the slit, There was a problem that the needle could not enter the slit and measurement could not be performed.

The present invention has been made in view of the above, and it is possible to measure the straightness of a processed surface even when the end surface of a measurement target is in a slit while suppressing an increase in apparatus size and cost. It aims at obtaining a wire electric discharge machine.

In order to solve the above-described problems and achieve the object, a wire electric discharge machine according to the present invention is a wire electric discharge machine that applies a voltage between a wire electrode and an object to be processed to process the object to be processed. A wire adjustment unit that changes a posture of the wire electrode with respect to the processing target, a contact detection unit that detects whether the wire electrode and the processing target are in contact with each other, And a straightness measuring unit that obtains the straightness of the processed surface of the processing object based on the posture of the wire electrode with respect to the processing object when contact with the object is detected.

The wire electric discharge machine according to the present invention is a wire electric discharge machine capable of measuring the straightness of the processed surface even when the end surface of the measurement object is in the slit while suppressing an increase in apparatus size and cost. There is an effect that it can be obtained.

The figure which shows the structure of the wire electric discharge machine concerning Embodiment 1 of this invention. The figure which shows the hardware structural example of the control apparatus shown in FIG. The figure which shows the function structure of the wire electric discharge machine shown in FIG. Explanatory drawing of the specification value input into the specification input part shown in FIG. The figure which shows a mode that the wire electrical discharge machine shown in FIG. 1 changes the relative position with respect to the workpiece of a wire electrode. The figure which shows the wire electrode by which the angle was adjusted by the angle adjustment part shown in FIG. The figure which shows a mode that the wire electric discharge machine shown in FIG. 1 adjusts the deflection amount of a wire electrode. The figure which shows a mode that the bending adjustment part shown in FIG. 3 adjusts the bending amount of a wire electrode by adjusting the tension | tensile_strength of a wire electrode. The figure which shows a mode that the bending adjustment part shown in FIG. 3 adjusts the bending amount of a wire electrode by applying a voltage between a wire electrode and a workpiece. The figure which shows a mode that the bending adjustment part shown in FIG. 3 adjusts the bending amount of a wire electrode by physically shaking a wire electrode. The flowchart which shows the operation | movement which the wire electric discharge machine shown in FIG. The flowchart which shows the detail of step S103 of FIG. The figure which shows the processing surface position when the processing surface is a Tyco shape The figure which shows the processing surface position when the processing surface is reverse Tyco shape The figure which shows the position measured in step S202 of FIG. 12, when a process surface is a Tyco shape. The figure which shows the position measured in step S202 of FIG. 12, when a process surface is reverse Tyco shape. The figure for demonstrating the function of the straightness measurement part shown in FIG. B part enlarged view of FIG. FIG. 1 is an explanatory diagram of a method for obtaining straightness when the wire electric discharge machine shown in FIG.

Hereinafter, a wire electric discharge machine and a straightness calculation method according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a wire electric discharge machine 100 according to a first embodiment of the present invention. The wire electric discharge machine 100 has a function of machining a workpiece W by applying a machining voltage between the wire electrode 1 and the workpiece W. Further, the wire electric discharge machine 100 further has a function of measuring the straightness ΔD of the processed surface Ws using the wire electrode 1 and a function of adjusting a processing condition using the measured straightness ΔD. Straightness ΔD indicates the amount of deviation from the original position of the processed surface Ws.

The wire electric discharge machine 100 applies a machining voltage between the table 11 that holds the workpiece W, the upper machining head 12 and the lower machining head 13 that hold the wire electrode 1, and the wire electrode 1 and the workpiece W. The power supply 14 for applying and the contact detection circuit 15 which detects the contact to the workpiece W of the wire electrode 1 are provided.

The table 11 is made of a conductor and has a hole in the center. The wire electrode 1 passed between the upper processing head 12 and the lower processing head 13 is passed through the hole of the table 11, and the wire electrode 1 can be moved in the region where the hole is formed. Yes. A workpiece W is placed on one surface of the table 11. Hereinafter, the surface on which the workpiece W of the table 11 is placed is referred to as a table surface 11a.

The power source 14 is electrically connected to each of the table 11 and the upper processing head 12. By applying a voltage between the table 11 and the upper processing head 12, the processing object W and the wire electrode 1 are connected. A voltage can be applied between them. The contact detection circuit 15 is electrically connected to each of the wire electrode 1 passing through the upper machining head 12 and the table 11. When the power supply 14 applies a voltage while the workpiece W is placed on the table 11, a voltage is applied between the wire electrode 1 and the workpiece W.

When the wire electrode 1 and the workpiece W are in contact with each other, the contact detection circuit 15 utilizes the fact that the voltage applied between the wire electrode 1 and the workpiece W is short-circuited. Contact with W can be detected. Specifically, the contact detection circuit 15 applies a potential difference between the wire electrode 1 and the workpiece W and measures the potential difference between the wire electrode 1 and the workpiece W. The potential difference applied between the wire electrode 1 and the workpiece W is set to such a magnitude that no discharge occurs between the wire electrode 1 and the workpiece W. The contact detection circuit 15 detects that the potential difference between the wire electrode 1 and the workpiece W has changed, so that the potential difference has changed, that is, the electrical contact between the wire electrode 1 and the workpiece W. Can be detected.

The wire electric discharge machine 100 includes an X-axis motor and a Y-axis motor (not shown) that move the upper machining head 12 and the lower machining head 13 together, and a U-axis motor and a V-axis motor (not shown) that move the upper machining head 12. And further. As the U-axis motor and the V-axis motor move the upper machining head 12, the inclination of the wire electrode 1 between the upper machining head 12 and the lower machining head 13 changes. The wire electric discharge machine 100 further includes a main tension roller 20 and a main tension motor 21 that rotates the main tension roller 20 above the upper machining head 12. The main tension motor 21 rotates the main tension roller 20 to wind the wire electrode 1, whereby the tension of the wire electrode 1 can be adjusted.

The wire electric discharge machine 100 includes a control device 22. The control device 22 is a device that controls the wire electric discharge machine 100 and is also called a numerical control device. In FIG. 1, only the connection between the control device 22 and the contact detection circuit 15 is shown, but in reality, the control device 22 includes the power supply 14, the contact detection circuit 15, the X-axis motor, the Y-axis motor, and the U-axis. Commands can be input to each of the motor, the V-axis motor, and the main tension motor 21. Thereby, the control device 22 performs the taper machining by changing the angle of the wire electrode 1 with respect to the table 11 and the X and Y axes for moving the upper machining head 12 and the lower machining head 13 together. And can be moved.

The wire electric discharge machine 100 can perform an electric discharge machining process by the controller 22 giving various commands. When the wire electrode 1 is brought close to the workpiece W in a state where a machining voltage is applied between the wire electrode 1 and the workpiece W, dielectric breakdown occurs and electric discharge occurs. When discharge occurs, an arc column is formed between the wire electrode 1 and the workpiece W, and a high-density arc current flows. For this reason, the workpiece W melts at a high temperature and the surrounding water undergoes a vaporization explosion, resulting in a phenomenon that the melted portion is skipped. By using such a phenomenon, the wire electric discharge machine 100 processes the workpiece W.

The machining speed, surface roughness, and machining accuracy vary depending on the magnitude of the arc current that flows between the wire electrode 1 and the workpiece W. Generally, the larger the arc current, the faster the machining speed, but the rougher the surface, the lower the machining accuracy. For this reason, in electric discharge machining using the wire electric discharge machine 100, generally, machining is performed a plurality of times while adjusting the magnitude of the arc current by changing electric parameters such as machining voltage. The types of processing can be classified into three types: roughing, intermediate finishing, and finishing. Roughing is a process of creating an approximate shape of a workpiece, and a relatively large current is used. The intermediate finishing process is a process of adjusting the accuracy of the shape created by the roughing process, and uses a smaller current than the roughing process. In intermediate finishing, a balance between fine surface roughness and processing speed is required. The finishing process is a process of reducing the surface roughness of the processed surface Ws, and uses a smaller current than that of the intermediate finishing process. In finishing, the fineness of the surface roughness is important. In the electric discharge machining using the wire electric discharge machine 100, the rough machining and the semi-finishing machining are performed once each, and then the finishing machining is repeatedly performed until a desired surface roughness is obtained. Note that the number of executions of the roughing process, the intermediate finishing process, and the finishing process varies according to the user's request.

Further, the wire electric discharge machine 100 monitors the detection result of the contact detection circuit 15 while changing the posture of the wire electrode 1 with respect to the workpiece W, so that the wire when the wire electrode 1 and the workpiece W are in contact with each other is monitored. The posture of the electrode 1 with respect to the workpiece W can be specified. The wire electric discharge machine 100 measures the straightness ΔD of the processing surface Ws based on the posture of the wire electrode 1 with respect to the processing target W when the wire electrode 1 and the processing target W come into contact with each other.

FIG. 2 is a diagram illustrating a hardware configuration example of the control device 22 illustrated in FIG. The control device 22 includes a processor 31, a memory 32, an input device 33, and an output device 34. The processor 31 is a CPU (Central Processing Unit) and is also called a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or the like. The memory 32 is, for example, a nonvolatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), Magnetic disks, flexible disks, optical disks, compact disks, mini disks, DVDs (Digital Versatile Disks), etc.

The input device 33 is a touch panel, a keyboard, a mouse, a trackball, or a combination thereof. The output device 34 is a display that outputs a display screen.

FIG. 3 is a diagram showing a functional configuration of the wire electric discharge machine 100 shown in FIG. The wire electric discharge machine 100 includes a specification input unit 101, a wire adjustment unit 102, a contact detection unit 103, a position detection unit 104, and an arithmetic control unit 105. The arithmetic control unit 105 includes a straightness measuring unit 106 and a machining condition adjusting unit 107. Note that FIG. 3 shows a portion of the functional configuration of the wire electric discharge machine 100 necessary for explaining the features of the invention according to the present embodiment, and the description of the function of performing the electric discharge machining process is here. I will omit it.

The wire electric discharge machine 100 measures the straightness ΔD of the machining surface Ws by monitoring the contact between the wire electrode 1 and the workpiece W while changing the posture of the wire electrode 1 with respect to the workpiece W. It has a function to measure the degree. In wire electric discharge machining, due to vibration of the wire electrode 1, machining speed, etc., the center part of the machining surface Ws has a concave shape than the end part, or the center part of the machining surface Ws is more than the end part. It may become a protruding inverted shape. In this case, the machining surface Ws is displaced from the original surface, and the machining accuracy is lowered.

Conventionally, every time the machining conditions are set and the electric discharge machining using the set machining conditions is performed, the workpiece W is removed from the wire electric discharge machine, and the straightness ΔD is manually measured using a micrometer. It was done repeatedly. Further, when a measuring device that measures the straightness ΔD using a stylus is provided, the straightness ΔD of the processing surface Ws can be measured while the workpiece W is attached to the wire electric discharge machine. As the size and cost increase, the stylus may not enter the slit and the straightness ΔD may not be measured when the processed surface Ws is in the slit. In contrast, in the wire electric discharge machine 100 according to the present embodiment, the straightness measurement function is used to set the machining conditions, the electric discharge machining process using the set machining conditions, and the measurement of the straightness ΔD. The processing conditions for forming the processing surface Ws having the desired straightness ΔD can be automatically determined without manual intervention. Also, the straightness measurement function can be used when adjusting the machining conditions while repeatedly performing electrical discharge machining.

The specification input unit 101 receives input of specification values necessary for using the proposed straightness measurement function. The specification input unit 101 is realized by the processor 31 of the control device 22 using the input device 33 and the output device 34 to read out and execute a computer program stored in the memory 32. The specification input unit 101 displays an input screen for inputting various specification values on the output device 34. When the user inputs specification values on the input screen by using the input device 33, the specification input unit 101 is input. Stores specification values.

FIG. 4 is an explanatory diagram of the specification values input to the specification input unit 101 shown in FIG. The specification value input to the specification input unit 101 is the distance in the Z-axis direction between the thickness Hw of the workpiece W and the upper end surface Wa of the workpiece W and the support portion 41 that supports the wire electrode 1. Zd1 and the distance Zd2 in the Z-axis direction between the lower end surface Wb of the workpiece W and the support portion 42 that supports the wire electrode 1 are included. The thickness Hw is the size of the plate-like workpiece W in the thickness direction. As shown in FIGS. 1 and 4, the Z-axis is directed in the direction perpendicular to the X-axis and the Y-axis defining the table surface 11a, and is directed in the thickness direction of the workpiece W. The user can measure the thickness Hw and the distances Zd1 and Zd2 and input them to the wire electric discharge machine 100.

The wire adjustment unit 102 changes the posture of the wire electrode 1 with respect to the workpiece W under the control of the arithmetic control unit 105. Here, changing the posture of the wire electrode 1 with respect to the workpiece W means that the relative position of the wire electrode 1 with respect to the workpiece W, the angle of the wire electrode 1 with respect to the workpiece W, and the deflection amount of the wire electrode 1 are changed. Adjusting at least one. The wire adjustment unit 102 further includes an angle adjustment unit 102a that makes the wire electrode 1 have an angle from a direction perpendicular to the table surface 11a, and a bending adjustment unit 102b that changes the amount of bending of the wire electrode 1.

Specifically, the wire adjustment unit 102 can horizontally move the upper machining head 12 and the lower machining head 13 integrally to change the relative position of the wire electrode 1 with respect to the workpiece W. At this time, the wire adjustment unit 102 is configured using at least one of an X-axis motor and a Y-axis motor. FIG. 5 is a diagram illustrating a state in which the wire electric discharge machine 100 illustrated in FIG. 1 changes the relative position of the wire electrode 1 with respect to the workpiece W. The wire adjustment unit 102 can horizontally move the table 11 until the wire electrode 1 comes into contact with the machining surface Ws of the workpiece W while the wire electrode 1 is perpendicular to the table surface 11a.

Also, the angle adjustment unit 102a of the wire adjustment unit 102 can change the angle θ of the wire electrode 1 with respect to the table surface 11a by moving the upper processing head 12 horizontally. At this time, the wire adjustment unit 102 is configured using at least one of a U-axis motor and a V-axis motor. FIG. 6 is a view showing the wire electrode 1 whose angle θ is adjusted by the angle adjusting unit 102a shown in FIG. The state in which the angle adjustment unit 102a does not adjust the angle θ is an angle θ = 90 degrees, and the wire electrode 1 is oriented in a direction perpendicular to the table surface 11a that is a placement surface of the workpiece W. For this reason, the state in which the angle θ is adjusted is a state in which the wire electrode 1 is angled from a direction perpendicular to the table surface 11a that is the mounting surface of the workpiece W, and the angles θ ≠ 0, 90. is there. FIG. 6 shows a state where the angle adjustment unit 102a moves the upper machining head 12 in the U-axis direction as Lu. Since the angle adjustment unit 102a translates the upper processing head 12, the distance Hz in the Z-axis direction between the support unit 41 and the support unit 42 is constant, and the distance between the support unit 41 and the support unit 42 is constant. The length of the wire electrode 1 changes.

Further, the deflection adjusting portion 102b of the wire adjusting portion 102 can bend the central portion of the wire electrode 1 between the

support portions

41 and 42 and adjust the deflection amount L thereof. FIG. 7 is a diagram illustrating a state in which the wire electric discharge machine 100 illustrated in FIG. 1 adjusts the deflection amount L of the wire electrode 1. When the processing surface Ws of the processing target W is a Tyco shape, the straightness ΔD can be obtained by adjusting the deflection amount L and detecting the contact position between the wire electrode 1 and the processing target W. Become. There are three methods for adjusting the bending amount L of the wire electrode 1 by the bending adjusting unit 102b. The following three methods include a method of controlling the deflection amount L by vibrating the wire electrode 1. In this case, the vibration width of the wire electrode 1 corresponds to the deflection amount L.

As a first method of adjusting the bending amount L, a method of adjusting the tension of the wire electrode 1 can be mentioned. In this case, the deflection adjusting unit 102 b is configured using the main tension motor 21 and the main tension roller 20. FIG. 8 is a diagram illustrating a state in which the bending adjustment unit 102 b illustrated in FIG. 3 adjusts the bending amount L of the wire electrode 1 by adjusting the tension of the wire electrode 1. The wire electric discharge machine 100 has a roller for winding the wire electrode 1, and the wire electrode 1 can be continuously run by winding the wire electrode 1 continuously. The bend adjustment unit 102b of the wire electric discharge machine 100 adjusts the bend amount L while the wire electrode 1 is running. In a state where the wire electrode 1 is caused to travel, vibration is generated in the wire electrode 1 due to fluctuation caused by rotation of a roller that winds the wire electrode 1 and other fluctuation caused by disturbance. When actually measured using a laser displacement meter, it was confirmed that the wire electrode 1 vibrates with a width of several tens of μm depending on the state of the wire electric discharge machine 100. In addition, it was confirmed that the vibration width, that is, the deflection amount L is changed by actually adjusting the tension of the wire electrode 1. Since the relationship between the tension and the deflection amount L changes depending on conditions such as the type of the wire electric discharge machine 100, the length of the wire electrode 1, and the thickness of the wire electrode 1, it is necessary to acquire measurement data in advance. There is. The bend adjustment unit 102b adjusts the tension of the wire electrode 1 based on the measurement data, and brings the wire electrode 1 into contact with the center portion of the processing surface Ws by reducing the tension during the measurement process than during the processing process. be able to.

As a second method for adjusting the bending amount L, there is a method of applying a voltage between the wire electrode 1 and the workpiece W. In this case, the deflection adjusting unit 102 b is configured using a power source provided in the contact detection circuit 15. FIG. 9 is a diagram illustrating a state in which the deflection adjustment unit 102b illustrated in FIG. 3 adjusts the deflection amount L of the wire electrode 1 by applying a voltage between the wire electrode 1 and the workpiece W. In FIG. 9, a pulse voltage is applied between the wire electrode 1 and the workpiece W to control the electrostatic attractive force, and the wire electrode 1 is vibrated. However, the present embodiment is not limited to such an example, and the wire electrode 1 may be bent by applying a DC voltage between the wire electrode 1 and the workpiece W. In addition, the voltage used here is lower than the machining voltage used when the wire electric discharge machine 100 performs electric discharge machining.

As a third method for adjusting the bending amount L, there is a method in which the wire electrode 1 is physically shaken to vibrate the wire electrode 1. In this case, the deflection adjusting unit 102b is configured using at least one of an X-axis motor and a Y-axis motor that move the upper processing head 12 and the lower processing head 13 integrally. FIG. 10 is a diagram illustrating a state in which the bending adjustment unit 102b illustrated in FIG. 3 adjusts the bending amount L of the wire electrode 1 by physically swinging the wire electrode 1. When at least one of the X-axis motor and the Y-axis motor is driven, the

support portions

41 and 42 of the wire electrode 1 are moved, and the wire electrode 1 can be shaken. The above three methods can also be used in combination. By using a combination of the three methods, the vibration width can be made larger than when using one method. Here, when the wire electrode 1 is vibrated, the bending amount L is a vibration width.

Returning to the explanation of FIG. The contact detection unit 103 detects contact between the wire electrode 1 and the workpiece W. The contact detection unit 103 includes a contact detection circuit 15. When the contact detection unit 103 detects the contact between the wire electrode 1 and the workpiece W, the contact detection unit 103 outputs a detection signal indicating that the contact has been detected to the calculation control unit 105. The contact detection unit 103 includes a contact detection circuit 15. The detection signal output from the contact detection unit 103 is input to the position detection unit 104 via the calculation control unit 105.

The position detection unit 104 is configured by the contact detection circuit 15 and detects the positions of the

support units

41 and 42 when the wire electrode 1 contacts the workpiece W. Specifically, the position detection unit 104 supports the XY plane based on the detection signal output from the contact detection unit 103 and the control amount performed by the wire adjustment unit 102 to change the posture of the wire electrode 1. The positions of the

parts

41 and 42 can be detected. For example, when the wire adjustment unit 102 horizontally moves the upper processing head 12 and the lower processing head 13 integrally, the position detection unit 104 uses the X-axis motor and Y until the wire electrode 1 comes into contact with the workpiece W. The positions of the

support portions

41 and 42 can be obtained based on the control amount of the shaft motor.

When the angle adjustment unit 102a adjusts the angle θ, the position detection unit 104 supports the support unit 41 based on the control amounts of the U-axis motor and the V-axis motor until the wire electrode 1 comes into contact with the workpiece W. , 42 can be obtained. When the deflection adjusting unit 102b adjusts the deflection amount L of the wire electrode 1, the positions of the

support portions

41 and 42 can be obtained based on the control amount corresponding to the method of adjusting the deflection amount L. When the bending adjustment unit 102 b adjusts the bending amount L of the wire electrode 1 by adjusting the tension of the wire electrode 1, the control amount includes the control amount of the main tension motor 21. When the deflection adjusting unit 102b adjusts the deflection amount L of the wire electrode 1 by applying a voltage between the wire electrode 1 and the workpiece W, the control amount is between the wire electrode 1 and the workpiece W. Includes a voltage pattern to be applied. When the bending adjustment unit 102b adjusts the bending amount L of the wire electrode 1 by physically swinging the wire electrode 1, the control amount includes control amounts of the X-axis motor and the Y-axis motor. The position detection unit 104 outputs the detection position to the calculation control unit 105.

The arithmetic control unit 105 controls the wire electric discharge machine 100. The arithmetic control unit 105 is configured using the processor 31 and the memory 32 of the control device 22 shown in FIG. The straightness measurement unit 106 receives the specification value input using the specification input unit 101, the control amount of the wire adjustment unit 102, the detection signal output by the contact detection unit 103, and the position detection unit 104. Based on the detected position, the straightness ΔD of the machining surface Ws of the workpiece W can be calculated.

The machining condition adjustment unit 107 adjusts the machining conditions for the next machining based on the straightness ΔD calculated by the straightness measurement unit 106. Various methods for adjusting the processing conditions are conceivable. When the straightness ΔD is equal to or greater than the threshold, for example, 10 μm or greater, the processing condition adjustment unit 107 can reduce the offset. Alternatively, when the straightness ΔD is less than the threshold value, the electrical parameter can be reduced. For example, a machining condition adjustment method is learned for each straightness ΔD by machine learning, and the machining condition adjustment unit 107 can adjust the machining condition based on the straightness ΔD using the learning result.

FIG. 11 is a flowchart showing an operation in which the wire electric discharge machine 100 shown in FIG. 1 creates a machining condition. Here, a case where three-stage electric discharge machining is performed is shown, but the present embodiment is not limited to such an example.

The calculation control unit 105 first sets candidates for the first processing condition (step S101). Then, the arithmetic control unit 105 controls the wire electric discharge machine 100 using the first machining condition, and executes electric discharge machining (step S102). After executing electric discharge machining, the arithmetic control unit 105 performs machining accuracy measurement processing (step S103). This measurement process includes calculation of the straightness ΔD by the straightness measuring unit 106. When the measurement process is finished, the arithmetic control unit 105 determines whether or not the measurement result satisfies the standard (step S104). When the measurement result does not satisfy the standard (step S104: No), the machining condition adjustment unit 107 of the calculation control unit 105 changes the first machining condition based on the measurement result (step S105). When the first processing condition is changed, the arithmetic control unit 105 returns to the process of step S102.

If the measurement result satisfies the standard (step S104: Yes), the arithmetic control unit 105 sets a candidate for the second processing condition (step S106). Then, the arithmetic control unit 105 controls the wire electric discharge machine 100 using the second machining condition, and executes electric discharge machining (step S107). After executing electric discharge machining, the arithmetic control unit 105 performs machining accuracy measurement processing (step S103). When the measurement process is finished, the arithmetic control unit 105 determines whether or not the measurement result satisfies the standard (step S108). When the measurement result does not satisfy the standard (step S108: No), the machining condition adjustment unit 107 of the calculation control unit 105 changes the second machining condition based on the measurement result (step S109). When the second processing condition is changed, the arithmetic control unit 105 returns to the process of step S107.

When the measurement result satisfies the standard (step S108: Yes), the arithmetic control unit 105 sets a candidate for the third processing condition (step S110). Then, the arithmetic control unit 105 controls the wire electric discharge machine 100 using the third machining condition, and executes electric discharge machining (step S111). After executing electric discharge machining, the arithmetic control unit 105 performs machining accuracy measurement processing (step S103). When the measurement process is finished, the arithmetic control unit 105 determines whether or not the measurement result satisfies the standard (step S112). When the measurement result does not satisfy the standard (step S112: No), the machining condition adjustment unit 107 of the calculation control unit 105 changes the third machining condition based on the measurement result (step S113). When the third processing condition is changed, the arithmetic control unit 105 returns to the process of step S111. When the measurement result satisfies the standard (step S112: Yes), the arithmetic control unit 105 ends the process.

FIG. 12 is a flowchart showing details of step S103 in FIG. The straightness measuring unit 106 first places the wire electrode 1 in a state perpendicular to the table surface 11a, which is a mounting surface of the workpiece W, horizontally moves the table 11, and the wire electrode 1 contacts the workpiece W. The machined surface position X1 that is the measured position is measured (step S201). FIG. 13 is a diagram showing the machining surface position X1 when the machining surface Ws has a Tyco shape. When the processing surface Ws has a shape of a tie, the upper end surface Wa and the lower end surface Wb of the workpiece W are in contact with the wire electrode 1. FIG. 14 is a diagram showing the machining surface position X1 when the machining surface Ws has an inverted Tyco shape. When the processing surface Ws has an inverted shape, the central portion in the thickness direction of the workpiece W is in contact with the wire electrode 1.

Returning to the explanation of FIG. Subsequently, the straightness measuring unit 106 changes the angle θ using the angle adjusting unit 102a, so that the wire electrode 1 is in contact with the portion where the machining surface Ws of the workpiece W is in contact with the upper end surface Wa or the lower end surface Wb. Then, the positions of the

support portions

41 and 42 are measured (step S202). FIG. 15 is a diagram illustrating the position X2 measured in step S202 of FIG. 12 when the processing surface Ws has a shape of a Tyco. When the position X2 of the support portion 42 is measured, the contact position X3 where the wire electrode 1 and the workpiece W are in contact with each other can be calculated by calculation described later. When the machining surface Ws has a shape of a tie, the calculated contact position X3 coincides with the machining surface position X1. FIG. 16 is a diagram illustrating the position X2 measured in step S202 of FIG. 12 when the processing surface Ws has an inverted Tyco shape. When the position X2 of the support portion 42 is measured, the contact position X3 where the wire electrode 1 and the workpiece W are in contact with each other can be calculated by calculation described later. When the machining surface Ws has an inverted shape, the calculated contact position X3 does not coincide with the machining surface position X1. Thus, since the relationship between the contact position X3 and the machining surface position X1 varies depending on the type of the shape of the machining surface Ws, the shape of the machining surface Ws can be classified based on this relationship.

Returning to the explanation of FIG. Subsequently, the straightness measuring unit 106 changes the bending amount L using the bending adjusting unit 102b, and measures the bending amount L when the wire electrode 1 contacts the workpiece W (step S203).

When the processing of step S201 to step S203 is completed, the straightness measurement unit 106 performs processing based on the processing surface position X1 that is the measurement result of step S201 and the position X2 of the support unit 42 that is the measurement result of step S202. The shape of the surface Ws is classified (step S204). FIG. 17 is a diagram for explaining the function of the straightness measuring unit 106 shown in FIG. In order to classify the shape of the processing surface Ws, the straightness measurement unit 106 first calculates an angle θ when the wire electrode 1 contacts the processing object W in step S202. The movement amount Lu is known based on the control amount of the support portion 42, and the distance Hz in the Z-axis direction is constant and can be calculated using the following mathematical formula (1). Therefore, the angle θ can be obtained by using the following mathematical formula (2).

Hz = Hw + Zd1 + Zd2 (1)
θ = tan ^-1 (Hz / Lu) (2)

FIG. 18 is an enlarged view of part B of FIG. Since the relationship of the following mathematical formula (3) is established between the unknown b and the distance Zd2, the mathematical formula (4) can be derived from the mathematical formula (3). Here, since the relationship of Formula (5) is established between the unknown number a and the unknown number b, the unknown number a is expressed by Formula (6) by substituting Formula (4) into Formula (5). The

Zd2 = bsinθ (3)
b = Zd2 / sinθ (4)
a = bcosθ (5)
a = Zd2 · cosθ / sinθ (6)

For this reason, since the distance Zd2 is known by obtaining the angle θ using the above equation (2), the unknown a can be obtained. If the unknown number a can be obtained, the contact position X3 is known. The straightness measurement unit 106 compares the contact position X3 with the machining surface position X1. Here, when the contact position X3 coincides with the machining surface position X1, the straightness measurement unit 106 can classify the machining surface Ws into a plane that is small enough to ignore the Tyco shape or the straightness ΔD. The straightness measurement unit 106 can classify the processed surface Ws into an inverted Tyco shape when the contact position X3 and the processed surface position X1 do not match.

Subsequently, the straightness measuring unit 106 calculates the straightness ΔD based on the classification of the processed surface shape (step S205). The straightness measurement unit 106 can obtain the straightness ΔD using a calculation method determined for each classification of the processed surface shape. Specifically, the straightness measuring unit 106 can calculate the straightness ΔD based on the measurement results of step S201 and step S202 when the processed surface Ws has an inverted shape. FIG. 18 further shows the processing surface position X1 and the straightness ΔD. The straightness ΔD can be expressed by the following mathematical formula (7). Since the unknown a can be obtained by the above procedure, the straightness ΔD can be obtained by using the machining surface position X1 and the position X2 of the support portion 42, which are measurement results.

ΔD = | X1-X2 | -a (7)

Further, the straightness measuring unit 106 can obtain the straightness ΔD using the measurement results of step S201 to step S203 when the processed surface Ws is a shape of a shape or a plane. FIG. 19 is an explanatory diagram of a method in which the wire electric discharge machine 100 shown in FIG. 1 obtains the straightness ΔD when the machining surface Ws has a shape of a tie. The straightness measurement unit 106 can acquire the position X4 of the

support units

41 and 42 when the deflection amount L and the deflection amount L are obtained as the measurement result of step S203. The straightness ΔD is expressed by the following formula (8) using the deflection amount L and the position X4 of the

support portions

41 and 42.

ΔD = L- | X1-X4 | ... (8)

As described above, according to the first embodiment of the present invention, in the wire electric discharge machine 100 that processes the workpiece W by applying a voltage between the wire electrode 1 and the workpiece W, the wire electrode 1, the straightness ΔD of the processed surface Ws is obtained based on the posture of the wire electrode 1 when the wire electrode 1 and the workpiece W come into contact with each other. According to the wire electric discharge machine 100, since the wire electrode 1 which is a component used for processing the workpiece W is used, it is not necessary to add a new component for measuring the straightness ΔD. Therefore, the straightness ΔD can be measured while the workpiece W is attached to the wire electric discharge machine 100 while suppressing an increase in the apparatus size and cost. Further, depending on the processing shape, the processing surface Ws may not be exposed to the outside and may be in the slit. In such a case, in a measuring instrument using a stylus, the stylus may not enter the slit. On the other hand, in the wire electric discharge machine 100, the slit is formed by the wire electrode 1, and therefore the slit is larger than the thickness of the wire electrode 1. Therefore, even when the processed surface is in the slit, the straightness ΔD of the processed surface Ws can be measured.

As described above, the wire electric discharge machine 100 can measure the straightness ΔD of the processed surface Ws while the workpiece W is attached to the wire electric discharge machine 100. For this reason, it becomes possible to automate a series of processes as shown in FIG. 11 in which the electric discharge machining, the measurement process, and the adjustment of the machining conditions are repeated a plurality of times. By being automated, it is possible to save the trouble of creating machining conditions for electric discharge machining, and it is possible to set machining conditions appropriately regardless of the skill of the person operating the wire electric discharge machine 100. become.

As a method of changing the posture of the wire electrode 1, a method of changing the angle of the wire electrode 1 with respect to the workpiece W can be mentioned. When the machining surface Ws has an inverted shape, the angle of the wire electrode 1 with respect to the workpiece W is changed, and the position of the portion where the machining surface Ws of the workpiece W is in contact with the upper end surface Wa or the lower end surface Wb. By measuring the straightness ΔD of the processed surface Ws can be measured.

As a method of changing the posture of the wire electrode 1, a method of changing the bending amount L of the wire electrode 1 can be mentioned. For example, the wire electrode 1 can be bent by vibrating the wire electrode 1. When the machining surface Ws has a shape of a tie, the position X4 when contacting the central portion of the machining surface Ws that is recessed from the upper end surface Wa and the lower end surface Wb can be measured by bending the wire electrode 1. It becomes possible. The straightness ΔD of the processed surface Ws is obtained using the position X4.

The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

In the above embodiment, the configuration of the wire electric discharge machine 100 has been described. However, the technology of the present embodiment can be realized by the control device 22 provided in the wire electric discharge machine 100 alone. Moreover, the technique of this Embodiment is also realizable as a storage medium which memorize | stores the control method of the wire electric discharge machine 100, the computer program for control of the wire electric discharge machine 100, and the computer program for control.

In the above embodiment, the wire electric discharge machine 100 moves the upper machining head 12 to adjust the angle of the wire electrode 1 with respect to the workpiece W. However, the present embodiment is an example of this. It is not limited. The angle of the wire electrode 1 relative to the workpiece W may be adjusted by moving the lower machining head 13. Further, the angle of the wire electrode 1 with respect to the workpiece W may be adjusted by moving both the upper machining head 12 and the lower machining head 13.

In the above embodiment, the wire electric discharge machine 100 has the X-axis motor and the Y-axis motor that horizontally move the upper machining head 12 and the lower machining head 13 integrally. It is not limited to such an example. You may provide the X-axis motor and Y-axis motor which move the table 11 horizontally. However, when the X-axis motor and the Y-axis motor move the table 11 horizontally, the deflection adjusting unit 102b cannot adjust the deflection amount L using the third method.

In the above-described embodiment, the specification input unit 101 and the calculation control unit 105 illustrated in FIG. 3 are functions of the control device 22, but the present embodiment is not limited to such an example. The functions of the specification input unit 101 and the arithmetic control unit 105 can be realized by using a processor and a memory other than the control device 22, or a dedicated processing circuit may be used.

1 wire electrode, 11 table, 11a table surface, 12 upper machining head, 13 lower machining head, 14 power supply, 15 contact detection circuit, 20 main tension roller, 21 main tension motor, 22 control device, 31 processor, 32 memory, 33 Input device, 34 output device, 41, 42 support unit, 100 wire electric discharge machine, 101 specification input unit, 102 wire adjustment unit, 102a angle adjustment unit, 102b deflection adjustment unit, 103 contact detection unit, 104 position detection unit, 105 arithmetic control unit, 106 straightness measurement unit, 107 machining condition adjustment unit, ΔD straightness, L deflection amount, W machining target, Wa upper end surface, Wb lower end surface, Ws machining surface.

Claims

A wire electric discharge machine that processes the workpiece by applying a voltage between the wire electrode and the workpiece,
A wire adjustment unit that changes the posture of the wire electrode with respect to the workpiece;
A contact detection unit that detects whether or not the wire electrode and the workpiece are in contact;
Straightness for determining the straightness of the processed surface of the workpiece based on the posture of the wire electrode with respect to the workpiece when contact between the wire electrode and the workpiece is detected by the contact detector A measuring section;
A wire electric discharge machine characterized by comprising:
The wire electric discharge machine according to claim 1, wherein the wire adjustment unit includes an angle adjustment unit that adjusts an angle of the wire electrode with respect to the workpiece.
3. The wire electric discharge machine according to claim 2, wherein the angle adjustment unit adjusts the angle by changing a position of a support unit that supports the wire electrode.
The straightness measurement unit includes the position of the processing surface measured in a state where the wire electrode is perpendicular to the mounting surface of the processing target, and the wire electrode and the processing target measured in a state where the angle is adjusted. 4. The wire discharge according to claim 2, wherein the shape of the processed surface is classified based on a contact position of the wire and the straightness is obtained using a calculation method determined for each classification. 5. Processing machine.
The wire electric discharge machine according to any one of claims 1 to 4, wherein the wire adjusting section includes a bending adjusting section that adjusts an amount of bending of the wire electrode.
6. The wire electric discharge machine according to claim 5, wherein the deflection adjusting unit adjusts the deflection amount, which is a vibration width of the wire electrode, by changing a tension of the vibrating wire electrode.
The wire electric discharge machine according to claim 5 or 6, wherein the bending adjustment unit adjusts the amount of bending by changing a voltage applied between the wire electrode and the workpiece. .
The bend adjustment unit vibrates the wire electrode by repeatedly applying a pulse voltage between the wire electrode and the workpiece, and adjusts the bend amount, which is a vibration width of the wire electrode. The wire electric discharge machine according to claim 7.
The bending adjustment unit bends the wire electrode by applying a DC voltage between the wire electrode and the workpiece, and adjusts the amount of bending by adjusting the value of the applied DC voltage. The wire electric discharge machine according to claim 7.
The said bending adjustment part moves the support part which supports the said wire electrode, vibrates the said wire electrode, and adjusts the said bending amount which is the vibration width of the said wire electrode. 10. The wire electric discharge machine according to any one of 9 above.
A machining condition adjusting unit that adjusts a machining condition based on the straightness calculated by the straightness measuring unit,
The wire electric discharge machine according to any one of claims 1 to 10, further comprising:
A wire electric discharge machine that processes a workpiece by applying a voltage between a wire electrode and the workpiece, a method for calculating the straightness of the processed surface of the workpiece,
A first measurement step of measuring a position at which the wire electrode contacts the workpiece in a state where the wire electrode is perpendicular to a surface on which the workpiece is placed;
A second measurement step of measuring a position at which the wire electrode contacts the processing object in a state where the posture of the wire electrode with respect to the processing object is changed;
A classification step of classifying the shape of the processed surface based on the measurement results of the first measurement step and the second measurement step;
Based on the measurement result and the classification result, the straightness calculation step for obtaining the straightness of the processed surface;
The straightness calculation method characterized by including.
The second measuring step measures a position where the wire electrode contacts the processing object in a state where the posture is changed by changing an angle of the wire electrode with respect to a surface on which the processing object is placed. And measuring a position where the wire electrode contacts the workpiece in a state where the posture is changed by changing a deflection amount of the wire electrode. The straightness calculation method according to 12.