Water supply device and control method of water supply device

Abstract

According to an embodiment of the present disclosure, a water supply device (16) for automatically supplying water to a wire electric discharge machine (10) is provided with: a first water supply path (50) for supplying water from outside the wire electric discharge machine (10) to a clear water tank (22) of the wire electric discharge machine (10); a first valve (52) that opens and closes the first water supply path (50); a second water supply path (56) for supplying water from the outside of the wire electric discharge machine (10) to the ion exchange unit (24); a second valve (58) that opens and closes the second supply path (56); and a circulation path (40) for conveying the working fluid from the ion exchange unit (24) to the rinsing tank (22).

Description

Technical Field

[0001] The present disclosure relates to a water supply device and a control method of the water supply device. Background Art

[0002] Japanese Utility Model Application Laid-Open No. 5-002816 discloses a machining fluid supply device for a wire electric discharge machine. When the machining fluid in the wire electric discharge machine is reduced, the machining fluid supply device automatically supplies tap water. Summary of the invention

[0003] When tap water is added to the machining fluid, the resistivity value [Ωm] of the machining fluid decreases. Therefore, it is necessary to circulate the machining fluid between the clean water tank and the ion exchange resin to increase the resistivity value of the machining fluid. Recently, a better water supply device and a control method for the water supply device are expected.

[0004] The first method disclosed in the present invention is a water supply device that automatically supplies water to an electrical discharge machine, and the water supply device comprises: a first water supply path that supplies water from the outside of the electrical discharge machine to at least any one of a clean water tank, a dirty water tank, and a processing tank of the electrical discharge machine; a first valve that opens and closes the first water supply path; a second water supply path that supplies water from the outside of the electrical discharge machine to an ion exchange part having an ion exchange resin provided on the electrical discharge machine; a second valve that opens and closes the second supply path; and a circulation path that transports processing fluid from the ion exchange part to the clean water tank.

[0005] A second aspect of the present invention is a control method for a water supply device that automatically supplies water to an electrical discharge machine, the water supply device comprising: a first water supply path that supplies water from the outside of the electrical discharge machine to at least any one of a clean water tank, a dirty water tank, and a processing tank of the electrical discharge machine; a first valve that opens and closes the first water supply path; a second water supply path that supplies water from the outside of the electrical discharge machine to an ion exchange section having an ion exchange resin provided on the electrical discharge machine; a second valve that opens and closes the second supply path; and a circulation path that transports processing fluid from the ion exchange section to the clean water tank, the control method comprising: a resistivity value acquisition step for acquiring the resistivity value of the processing fluid; a dirty water tank water level acquisition step for acquiring the water level of the dirty water tank; a processing tank water level acquisition step for acquiring the water level of the processing tank; and a control step for opening and closing the first valve and the second valve according to the resistivity value, the water level of the dirty water tank, and the water level of the processing tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram of a wire electrical discharge machine. Figure 2 It is a block diagram of the water supply control unit. Figure 3This is a flowchart showing a water supply control process executed in the water supply control unit. Figure 4 This is a flowchart showing a water supply control process executed in the water supply control unit. Figure 5 This is a flowchart showing a water supply control process executed in the water supply control unit. Figure 6 This is a schematic diagram of a wire electrical discharge machine. Figure 7 This is a schematic diagram of a wire electrical discharge machine. DETAILED DESCRIPTION

[0007] When the machining fluid of the electric discharge machine is reduced, water is supplied to the electric discharge machine from the outside of the electric discharge machine. When water is added to the machining fluid, the resistivity value [Ωm] of the machining fluid decreases. Therefore, before the start of electric discharge machining, it is necessary to circulate the machining fluid between the clean water tank and the ion exchange resin to increase the resistivity value [Ωm] of the machining fluid. As a result, there is a problem that the period from the addition of water to the machining fluid to the start of electric discharge machining becomes longer. The subject of the present invention is to shorten the period from the addition of water to the machining fluid to the start of electric discharge machining.

[0008] In the present disclosure, the resistivity value [Ωm] is used for explanation, but the conductivity [S / m] may be used instead of the resistivity value [Ωm]. When water is added to the machining fluid, the conductivity [S / m] of the machining fluid increases. The conductivity [S / m] is the reciprocal of the resistivity value [Ωm]. That is, increasing the resistivity value [Ωm] is synonymous with decreasing the conductivity [S / m].

[0009] [First embodiment] [Structure of Wire EDM] Figure 1 1 is a schematic diagram of a wire electrical discharge machine 10. The wire electrical discharge machine 10 includes a machine body 12, a machining fluid treatment device 14, and a water supply device 16. The wire electrical discharge machine 10 corresponds to the electrical discharge machine of the present invention.

[0010] The processing machine body 12 has a processing tank 18. The processing machine body 12 performs electrical discharge processing on a workpiece in a state where a processing fluid is stored in the processing tank 18.

[0011] The machining fluid treatment device 14 includes a dirty water tank 20 , a clean water tank 22 , an ion exchange unit 24 , and a machining fluid treatment control unit 26 .

[0012] The waste water tank 20 is connected to the machining tank 18 via a drainage path 28. The machining fluid is discharged from the machining tank 18 to the waste water tank 20. The machining fluid discharged from the machining tank 18 to the waste water tank 20 contains sludge and the like generated during the electrical discharge machining of the workpiece.

[0013] The sewage tank 20 is connected to the clean water tank 22 via a filter path 30. The filter path 30 is provided with a first pump 32 and a filter 34. The first pump 32 sucks the machining fluid from the sewage tank 20 and sends it to the clean water tank 22. The filter 34 filters the machining fluid sent from the sewage tank 20 to the clean water tank 22 to remove sludge and the like from the machining fluid.

[0014] The sewage tank 20 is provided with a sewage tank water level measuring unit 36 ​​. The sewage tank water level measuring unit 36 ​​measures the water level of the machining fluid stored in the sewage tank 20 .

[0015] The machining tank 18 is provided with a machining tank water level measuring unit 37 . The machining tank water level measuring unit 37 measures the water level of the machining fluid stored in the machining tank 18 .

[0016] The clean water tank 22 is connected to the ion exchange unit 24 via a first circulation path 38 and a second circulation path 40. A second pump 42 and a circulation valve 44 are provided on the first circulation path 38. The machining fluid in the clean water tank 22 is sent to the ion exchange unit 24 through the first circulation path 38. The machining fluid that has passed through the ion exchange resin in the ion exchange unit 24 is returned to the clean water tank 22 through the second circulation path 40. The second circulation path 40 is equivalent to the circulation loop of the present invention.

[0017] The clean water tank 22 is provided with a resistivity value measuring unit 46 . The resistivity value measuring unit 46 measures the resistivity value [Ωm] of the machining fluid stored in the clean water tank 22 .

[0018] The ion exchange unit 24 has an ion exchange resin inside. The second pump 42 circulates the machining fluid between the clean water tank 22 and the ion exchange unit 24. The ion exchange resin exchanges ions contained in the machining fluid passing through the ion exchange resin for other ions. This increases the resistivity value [Ωm] of the machining fluid.

[0019] The machining tank 18 is connected to the clean water tank 22 via a machining fluid supply path 48. The machining tank 18 is supplied with a machining fluid having an adjusted resistivity value [Ωm].

[0020] The circulation valve 44 adjusts the amount of the machining fluid that circulates between the clean water tank 22 and the ion exchange unit 24 .

[0021] The machining fluid processing control unit 26 controls the circulation valve 44 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22. The resistivity value [Ωm] of the machining fluid in the clean water tank 22 is maintained at a predetermined value by controlling the opening degree or opening time of the circulation valve 44 by the machining fluid processing control unit 26. In addition, the function of the machining fluid processing control unit 26 may be incorporated into a numerical controller that controls the processing machine body 12.

[0022] The water supply device 16 includes a first water supply path 50 , a second water supply path 56 , and a water supply control unit 60 .

[0023] The first water supply path 50 is connected to the clean water tank 22. Tap water is supplied from the outside of the wire EDM 10 to the clean water tank 22 via the first water supply path 50. A first valve 52 is provided on the first water supply path 50. The first valve 52 adjusts the amount of tap water supplied to the clean water tank 22. When tap water is supplied to the clean water tank 22 in a state where the clean water tank 22 is full of water, the machining fluid in the clean water tank 22 exceeds the partition 54 between the clean water tank 22 and the dirty water tank 20 and flows into the dirty water tank 20.

[0024] The second water supply path 56 is connected to the ion exchange unit 24. Tap water is supplied from the outside of the wire electrical discharge machine 10 to the ion exchange unit 24 via the second water supply path 56. The second valve 58 is provided on the second water supply path 56. The second valve 58 adjusts the amount of tap water supplied to the ion exchange unit 24.

[0025] The water supplied from the outside of the wire electrical discharge machine 10 is not limited to tap water, and may be ground water or the like.

[0026] The water supply control unit 60 controls the first valve 52 and the second valve 58 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22 and the water level of the dirty water tank 20. The water supply control process performed in the water supply control unit 60 will be described in detail later. In addition, the function of the water supply control unit 60 can also be incorporated into the numerical control device that controls the processing machine body 12.

[0027] [Composition of water supply control unit] Figure 2: is a block diagram of the water supply control unit 60. The water supply control unit 60 includes a computing unit 62 and a storage unit 64. The computing unit 62 is a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The computing unit 62 includes a resistivity value acquisition unit 66, a sewage tank water level acquisition unit 68, a processing tank water level acquisition unit 69, and a valve control unit 70. The resistivity value acquisition unit 66, the sewage tank water level acquisition unit 68, the processing tank water level acquisition unit 69, and the valve control unit 70 are implemented by the computing unit 62 executing a program stored in the storage unit 64. At least a part of the resistivity value acquisition unit 66, the sewage tank water level acquisition unit 68, the processing tank water level acquisition unit 69, and the valve control unit 70 may also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). At least a part of the resistivity value acquisition unit 66 , the sewage tank water level acquisition unit 68 , the processing tank water level acquisition unit 69 , and the valve control unit 70 may also be implemented by an electronic circuit including discrete devices.

[0028] The storage unit 64 is composed of a volatile memory (not shown) and a non-volatile memory (not shown) as a computer-readable storage medium. Examples of volatile memory include RAM (Random Access Memory). Examples of non-volatile memory include ROM (Read Only Memory), flash memory, etc. Data, etc. are stored in the volatile memory, for example. Programs, tables, mappings, etc. are stored in the non-volatile memory, for example. At least a portion of the storage unit 64 may also be provided in the above-mentioned processor, integrated circuit, etc. At least a portion of the storage unit 64 may also be mounted on a device connected to the wire discharge machine 10 via a network.

[0029] The resistivity value acquisition unit 66 acquires the resistivity value of the machining fluid in the clean water tank 22 measured by the resistivity value measurement unit 46 .

[0030] The sewage tank water level acquisition unit 68 acquires the water level of the sewage tank 20 measured by the sewage tank water level measurement unit 36 ​​.

[0031] The machining tank water level acquisition unit 69 acquires the water level of the machining tank 18 measured by the machining tank water level measurement unit 37 .

[0032] The valve control unit 70 controls the first valve 52 and the second valve 58 of the water supply device 16 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22 and the water level of the dirty water tank 20. As a result, the water level of the machining fluid in the dirty water tank 20 rises. The resistivity value [Ωm] of the machining fluid in the clean water tank 22 rises. The valve control unit 70 is equivalent to the control unit of the present invention.

[0033] [Water supply control processing] Figure 3 2 is a flowchart showing a water supply control process executed in the water supply control unit 60. The water supply control process is repeatedly executed in a predetermined cycle.

[0034] In step S1, the valve control unit 70 determines whether the water level of the sewage tank 20 measured by the sewage tank water level measuring unit 36 ​​is lower than a predetermined water level. If the water level is lower than the predetermined water level (step S1: Yes), the process proceeds to step S2. If the water level is higher than the predetermined water level (step S1: No), the process proceeds to step S5.

[0035] In step S2, the valve control unit 70 determines whether the resistivity value [Ωm] of the machining fluid in the clean water tank 22 measured by the resistivity value measuring unit 46 is less than a threshold value. When the resistivity value [Ωm] is less than the threshold value (step S2: "Yes"), the process proceeds to step S3. When the resistivity value [Ωm] is greater than the threshold value (step S2: "No"), the process proceeds to step S4. The threshold value may be a value equal to the specified value of the resistivity value [Ωm]. The threshold value may be a value smaller than the specified value of the resistivity value [Ωm].

[0036] In step S3, the valve control unit 70 controls the first valve 52 to close the first valve 52. In addition, the valve control unit 70 controls the second valve 58 to open the second valve 58. Then, the process returns to step S1. In addition, before the process of step S3, when the first valve 52 is in a closed state, the first valve 52 is maintained in a closed state. Before the process of step S3, when the second valve 58 is in an open state, the second valve 58 is maintained in an open state.

[0037] In step S4, the valve control unit 70 controls the first valve 52 to open the first valve 52. In addition, the valve control unit 70 controls the second valve 58 to close the second valve 58. Then, the process returns to step S1. In addition, before the process of step S4, when the first valve 52 is in an open state, the first valve 52 is maintained in an open state. Before the process of step S4, when the second valve 58 is in a closed state, the second valve 58 is maintained in a closed state.

[0038] In step S5, the valve control unit 70 controls the first valve 52 to close the first valve 52. In addition, the valve control unit 70 controls the second valve 58 to close the second valve 58. Then, the water supply control process is terminated. In addition, before the process of step S5, when the first valve 52 is in a closed state, the first valve 52 is maintained in a closed state. Before the process of step S5, when the second valve 58 is in a closed state, the second valve 58 is maintained in a closed state.

[0039] [Effects] When the machining fluid of the wire EDM 10 is reduced, water is supplied to the clean water tank 22 from the outside of the wire EDM 10. When water is added to the machining fluid, the resistivity value [Ωm] of the machining fluid decreases. Therefore, before the start of EDM, the machining fluid needs to be circulated between the clean water tank 22 and the ion exchange unit 24 to increase the resistivity value [Ωm] of the machining fluid. Therefore, there is a problem that the period from adding water to the machining fluid to starting EDM becomes longer.

[0040] Compared with the case where water is directly supplied to the clean water tank 22 while the machining fluid is circulated between the clean water tank 22 and the ion exchange unit 24, the resistivity value [Ωm] can be increased more quickly when water is directly supplied to the ion exchange unit 24 and water that has passed through the ion exchange resin is transported from the ion exchange unit 24 to the clean water tank 22.

[0041] Here, the water supply device 16 of the present embodiment has a second water supply path 56 for supplying water from the outside of the wire EDM 10 to the ion exchange unit 24, in addition to the first water supply path 50 for supplying water from the outside of the wire EDM 10 to the clean water tank 22. Thus, when water is supplied from the outside of the wire EDM 10 to the wire EDM 10, the water supply device 16 can shorten the period required to increase the resistivity value [Ωm] of the machining fluid to a predetermined value.

[0042] In the water supply device 16 of the present embodiment, the water supply control unit 60 opens and closes the first valve 52 and the second valve 58 according to the resistivity value [Ωm] of the machining fluid and the water level of the sewage tank 20. Thus, the water supply device 16 can increase the resistivity value [Ωm] of the machining fluid while raising the water level of the sewage tank 20.

[0043] [Second embodiment] In the present embodiment, the content of the water supply control process is different from that in the first embodiment.

[0044] [Water supply control processing] Figure 4 2 is a flowchart showing a water supply control process executed in the water supply control unit 60. The water supply control process is repeatedly executed in a predetermined cycle.

[0045] In step S11, the valve control unit 70 determines whether the water level of the sewage tank 20 measured by the sewage tank water level measuring unit 36 ​​is less than a predetermined water level. If the water level is less than the predetermined water level (step S11: Yes), the process proceeds to step S12. If the water level is greater than the predetermined water level (step S11: No), the water supply control process ends.

[0046] In step S12, the valve control unit 70 sets the opening time of the first valve 52 based on the resistivity value [Ωm] of the machining fluid in the clean water tank 22, the water level of the waste water tank 20, and the water level of the machining tank 18. In addition, the valve control unit 70 sets the opening time of the second valve 58 based on the resistivity value [Ωm] of the machining fluid in the clean water tank 22, the water level of the waste water tank 20, and the water level of the machining tank 18. Then, the process moves to step S13.

[0047] The opening time of the first valve 52 and the opening time of the second valve 58 are set based on the difference between the amount of machining fluid currently stored in the sewage tank 20 and the amount of machining fluid currently stored in the processing tank 18, relative to the capacity of the machining fluid that can be stored in the sewage tank 20. Hereinafter, this difference may be described as the required water supply. The amount of machining fluid currently stored in the sewage tank 20 is calculated based on the current water level of the sewage tank 20 measured by the sewage tank water level measuring unit 36. The amount of machining fluid currently stored in the processing tank 18 is calculated based on the current water level of the processing tank 18 measured by the processing tank water level measuring unit 37.

[0048] In addition, the opening time of the first valve 52 and the opening time of the second valve 58 are set according to the difference between the resistivity value [Ωm] of the water before passing through the ion exchange resin of the ion exchange section 24 and the resistivity value [Ωm] of the water after passing through the ion exchange resin. Hereinafter, this difference may be recorded as the resistivity value increase. The resistivity value [Ωm] of the water before passing through the ion exchange resin of the ion exchange section 24 and the resistivity value [Ωm] of the water after passing through the ion exchange resin are measured in advance. The valve control section 70 sets the opening time of the first valve 52 and the opening time of the second valve 58 in a manner that the resistivity value [Ωm] of the machining fluid in the clean water tank 22 approaches a specified value according to the required water supply amount and the resistivity value increase.

[0049] Hereinafter, the set opening time of the first valve 52 may be described as a first set time. Also, the set opening time of the second valve 58 may be described as a second set time.

[0050] In step S13, the valve control unit 70 opens the first valve 52. At this time, the second valve 58 is closed. Then, the process moves to step S14.

[0051] In step S14, the valve control unit 70 determines whether the time (opening time) during which the first valve 52 is open is longer than the first setting time. If the opening time of the first valve 52 is longer than the first setting time (step S14: Yes), the process moves to step S15. If the opening time of the first valve 52 is shorter than the first setting time (step S14: No), the process repeats the determination of step S14.

[0052] In step S15, the valve control unit 70 closes the first valve 52. At this time, the second valve 58 is closed. Then, the process moves to step S16.

[0053] In step S16, the valve control unit 70 opens the second valve 58. At this time, the first valve 52 is closed. Then, the process moves to step S17.

[0054] In step S17, the valve control unit 70 determines whether the time (opening time) during which the second valve 58 is open is longer than the second setting time. If the opening time of the second valve 58 is longer than the second setting time (step S17: "Yes"), the process moves to step S18. If the opening time of the first valve 52 is shorter than the second setting time (step S17: "No"), the process repeats the determination of step S17.

[0055] In step S18, the valve control unit 70 closes the second valve 58. At this time, the first valve 52 is closed. Then, the water supply control process ends.

[0056] [Effects] In the water supply device 16 of the present embodiment, when the water level of the sewage tank 20 is lower than the predetermined water level, the water supply control unit 60 sets the opening time (first setting time) of the first valve 52 and the opening time (second setting time) of the second valve 58 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22 and the water level of the sewage tank 20. The water supply control unit 60 controls the first valve 52 and the second valve 58 to open the first valve 52 and close the second valve 58. Then, when the first setting time has passed, the water supply control unit 60 closes the first valve 52 and opens the second valve 58. Then, when the second setting time has passed, the water supply control unit 60 closes the second valve 58. Thus, the water supply device 16 can increase the resistivity value [Ωm] of the machining fluid while raising the water level of the sewage tank 20.

[0057] [Third Embodiment] In the present embodiment, the content of the water supply control process is different from that in the first embodiment.

[0058] [Water supply control processing] Figure 5 2 is a flowchart showing a water supply control process executed in the water supply control unit 60. The water supply control process is repeatedly executed in a predetermined cycle.

[0059] In step S21, the valve control unit 70 determines whether the water level of the sewage tank 20 measured by the sewage tank water level measuring unit 36 ​​is less than a predetermined water level. If the water level is less than the predetermined water level (step S21: Yes), the process proceeds to step S22. If the water level is greater than the predetermined water level (step S21: No), the water supply control process ends.

[0060] In step S22, the valve control unit 70 sets the opening of the first valve 52 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22, the water level of the waste water tank 20, and the water level of the machining tank 18. The valve control unit 70 sets the opening of the second valve 58 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22, the water level of the waste water tank 20, and the water level of the machining tank 18. The valve control unit 70 sets the common opening time of the first valve 52 and the second valve 58 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22, the water level of the waste water tank 20, and the water level of the machining tank 18. Then, the process moves to step S23.

[0061] The opening degree of the first valve 52, the opening degree of the second valve 58, and the opening time are set based on the difference between the amount of machining fluid currently stored in the sewage tank 20 and the amount of machining fluid currently stored in the processing tank 18, relative to the capacity of the machining fluid that can be stored in the sewage tank 20. Hereinafter, this difference may be recorded as the required water supply. The amount of machining fluid currently stored in the sewage tank 20 is obtained based on the current water level of the sewage tank 20 measured by the sewage tank water level measuring unit 36. The amount of machining fluid currently stored in the processing tank 18 is obtained based on the current water level of the processing tank 18 measured by the processing tank water level measuring unit 37.

[0062] In addition, the opening degree of the first valve 52, the opening degree of the second valve 58, and the opening time are set according to the difference between the resistivity value [Ωm] of the water before passing through the ion exchange resin of the ion exchange section 24 and the resistivity value [Ωm] of the water after passing through the ion exchange resin. Hereinafter, this difference may be recorded as the resistivity value increase. The resistivity value [Ωm] of the water before passing through the ion exchange resin of the ion exchange section 24 and the resistivity value [Ωm] of the water after passing through the ion exchange resin are measured in advance. The valve control section 70 sets the opening degree of the first valve 52, the opening degree of the second valve 58, and the opening time according to the necessary water supply and the resistivity value increase so that the resistivity value [Ωm] of the machining fluid in the clean water tank 22 approaches a specified value.

[0063] Hereinafter, the set common opening time of the first valve 52 and the second valve 58 will be described as the set time.

[0064] In step S23, the valve control unit 70 opens the first valve 52 and the second valve 58. At this time, the first valve 52 is set to the opening degree set in step S22. The second valve 58 is set to the opening degree set in step S22. Then, the process moves to step S24.

[0065] In step S24, the valve control unit 70 determines whether the time (opening time) during which the first valve 52 and the second valve 58 are open is longer than the set time. If the opening time of the first valve 52 and the second valve 58 is longer than the set time (step S24: "Yes"), the process moves to step S25. If the opening time of the first valve 52 and the second valve 58 is shorter than the set time (step S24: "No"), the process repeats the determination of step S24.

[0066] In step S25, the valve control unit 70 closes the first valve 52 and the second valve 58. Then, the water supply control process ends.

[0067] [Effects] In the water supply device 16 of the present embodiment, when the water level of the sewage tank 20 is lower than the predetermined water level, the water supply control unit 60 sets the opening of the first valve 52, the opening of the second valve 58, and the common opening time of the first valve 52 and the second valve 58 according to the resistivity value [Ωm] of the machining fluid in the clean water tank 22 and the water level of the sewage tank 20. The water supply control unit 60 opens the first valve 52 and sets the opening to the set opening of the first valve 52. In addition, the water supply control unit 60 opens the second valve 58 and sets the opening to the set opening of the second valve 58. Then, when the set opening time has passed, the water supply control unit 60 closes the first valve 52 and the second valve 58. Thus, the water supply device 16 can increase the resistivity value [Ωm] of the machining fluid while raising the water level of the sewage tank 20.

[0068] [Modifications] In the first to third embodiments, the first water supply path 50 is connected to the clean water tank 22. However, the first water supply path 50 may be connected to the dirty water tank 20 or the processing tank 18.

[0069] Figure 6 2 is a schematic diagram of the wire electrical discharge machine 10. A first water supply path 50 is connected to the sewage tank 20. Tap water is supplied to the sewage tank 20 from the outside of the wire electrical discharge machine 10 through the first water supply path 50.

[0070] Figure 7 1 is a schematic diagram of the wire electrical discharge machine 10. A first water supply path 50 is connected to the machining tank 18. Tap water is supplied to the machining tank 18 from the outside of the wire electrical discharge machine 10 through the first water supply path 50.

[0071] The following additional remarks are disclosed in relation to the above-mentioned embodiment and modified examples.

[0072] (Note 1) A water supply device (16) for automatically supplying water to an electric discharge machine (10), the water supply device comprising: a first water supply path (50) for supplying water from the outside of the electric discharge machine to at least any one of a clean water tank (22), a dirty water tank (20) and a processing tank (18) of the electric discharge machine; a first valve (52) for opening and closing the first water supply path; a second water supply path (56) for supplying water from the outside of the electric discharge machine to an ion exchange unit (24) having an ion exchange resin provided on the electric discharge machine; a second valve (58) for opening and closing the second supply path; and a circulation path (40) for conveying a processing fluid from the ion exchange unit to the clean water tank. Thus, when water is supplied from the outside of the electric discharge machine to the electric discharge machine, the water supply device can shorten the period required to increase the resistivity value of the processing fluid to a specified value.

[0073] (Note 2) In the water supply device described in Appendix 1, the water supply device may include: a resistivity value acquisition unit (66) for acquiring the resistivity value of the machining fluid; a sewage tank water level acquisition unit (68) for acquiring the water level of the sewage tank; a processing tank water level acquisition unit (69) for acquiring the water level of the processing tank; and a control unit (70) for opening and closing the first valve and the second valve according to the resistivity value, the water level of the sewage tank, and the water level of the processing tank. In this way, the water supply device can increase the resistivity value of the machining fluid while raising the water level of the sewage tank.

[0074] (Note 3) In the water supply device described in Appendix 2, when the water level is lower than a predetermined water level, the control unit may set the opening time of each of the first valve and the second valve according to the resistivity value and the water level, and control the first valve and the second valve so as to open one of the first valve and the second valve and close the other, and then, when the opening time set for one of the first valve and the second valve has passed, close one of the first valve and the second valve and open the other, and then, when the opening time set for the other of the first valve and the second valve has passed, close the other of the first valve and the second valve. Thus, the water supply device can raise the resistivity value of the machining fluid while raising the water level of the sewage tank.

[0075] (Note 4) In the water supply device described in Appendix 2, when the water level is lower than a predetermined water level, the control unit may set the respective openings of the first valve and the second valve and the common opening time of the first valve and the second valve according to the resistivity value and the water level, and control the first valve and the second valve so that the first valve is opened at the set opening, and the second valve is opened at the set opening, and then the first valve and the second valve are closed when the set opening time has elapsed. Thus, the water supply device can increase the resistivity value of the machining fluid while raising the water level of the sewage tank.

[0076] (Note 5) A control method for a water supply device for automatically supplying water to an electric discharge machine, the water supply device comprising: a first water supply path for supplying water from the outside of the electric discharge machine to at least any one of a clean water tank, a dirty water tank and a processing tank of the electric discharge machine; a first valve for opening and closing the first water supply path; a second water supply path for supplying water from the outside of the electric discharge machine to an ion exchange part having an ion exchange resin provided on the electric discharge machine; a second valve for opening and closing the second supply path; and a circulation path for conveying a processing fluid from the ion exchange part to the clean water tank, the control method comprising: a resistivity value acquisition step for acquiring a resistivity value of the processing fluid; a dirty water tank water level acquisition step for acquiring a water level of the dirty water tank; a processing tank water level acquisition step for acquiring a water level of the processing tank; and a control step for opening and closing the first valve and the second valve according to the resistivity value, the water level of the dirty water tank and the water level of the processing tank. Thus, the water supply device can increase the resistivity value of the processing fluid while raising the water level of the dirty water tank.

[0077] (Note 6) In the control method of the water supply device described in Supplement 5, in the control step, when the water level is lower than a predetermined water level, the opening time of each of the first valve and the second valve is set according to the resistivity value and the water level, and the first valve and the second valve are controlled so that one of the first valve and the second valve is opened and the other is closed, and then, when the opening time set for one of the first valve and the second valve has passed, one of the first valve and the second valve is closed and the other is opened, and then, when the opening time set for the other of the first valve and the second valve has passed, the other of the first valve and the second valve is closed. In this way, the water supply device can increase the resistivity value of the machining fluid while raising the water level of the sewage tank.

[0078] (Note 7) In the control method of the water supply device described in Supplement 5, it is also possible that in the control step, when the water level is less than a specified water level, the openings of the first valve and the second valve are set according to the resistivity value and the water level, and the first valve and the second valve are controlled so that the first valve is opened at the set opening and the second valve is opened at the set opening, and then the first valve and the second valve are closed when the set opening time has passed. In this way, the water supply device can increase the resistivity value of the machining fluid while raising the water level of the sewage tank.

[0079] Although the embodiments of the present disclosure have been described in detail, the present disclosure is not limited to the above-mentioned embodiments. These embodiments may be added, replaced, changed, partially deleted, etc. in a range that does not deviate from the main idea of ​​the invention, or in a range that does not deviate from the idea and main idea of ​​the present invention derived from the contents recorded in the technical solution and its equivalents. For example, in the above-mentioned embodiments, the order of each action and the order of each processing are shown as an example, and are not limited to this. In addition, the same applies to the case where numerical values ​​or mathematical formulas are used in the description of the above-mentioned embodiments. Explanation of symbols

[0080] 10…Wire EDM (Electrical Discharge Machine) 16...Water supply device 18...Processing tank 20…Sewage tank 22…Clean water tank 24 ... ion exchange unit 40 ... second circulation path (circulation path) 50 ... first water supply path 52 ... first valve 56 ... Second water supply path 58 ... Second valve 66 ... resistivity value acquisition unit 68 ... sewage tank water level acquisition unit 69 ...Processing tank water level acquisition unit 70 ...Valve control unit (control unit).

Claims

1. A water supply device for automatically supplying water to an electrical discharge machine, characterized in that: have: a first water supply path for supplying water from the outside of the electrical discharge machine to at least any one of a clean water tank, a dirty water tank, and a machining tank of the electrical discharge machine; a first valve that opens and closes the first water supply path; a second water supply path for supplying water from the outside of the electrical discharge machine to an ion exchange portion having an ion exchange resin provided on the electrical discharge machine; a second valve that opens and closes the second water supply path; as well as A circulation path is provided for conveying the machining fluid from the ion exchange unit to the clean water tank.

2. The water supply device according to claim 1, characterized in that: have: a resistivity value acquiring unit, which acquires the resistivity value of the processing fluid; A sewage tank water level acquisition unit, which acquires the water level of the sewage tank; a processing tank water level acquisition unit, which acquires the water level of the processing tank; and A control unit opens and closes the first valve and the second valve according to the resistivity value, the water level of the sewage tank, and the water level of the processing tank.

3. The water supply device according to claim 2, characterized in that: The control unit performs the following control: When the water level is lower than a specified water level, the opening time of the first valve and the second valve are set according to the resistivity value and the water level. controlling the first valve and the second valve so that one of the first valve and the second valve is opened and the other is closed, Then, when the opening time set for one of the first valve and the second valve has elapsed, one of the first valve and the second valve is closed and the other is opened, Thereafter, when the opening time set for the other of the first valve and the second valve has elapsed, the other of the first valve and the second valve is closed.

4. The water supply device according to claim 2, characterized in that: The control unit performs the following control: When the water level is lower than a specified water level, the respective openings of the first valve and the second valve and the common opening time of the first valve and the second valve are set according to the resistivity value and the water level; controlling the first valve and the second valve so that the first valve is opened at a set opening degree and the second valve is opened at a set opening degree, Thereafter, when the set opening time has passed, the first valve and the second valve are closed.

5. A method for controlling a water supply device for automatically supplying water to an electrical discharge machine, characterized in that: The water supply device comprises: a first water supply path for supplying water from the outside of the electrical discharge machine to at least any one of a clean water tank, a dirty water tank, and a machining tank of the electrical discharge machine; a first valve that opens and closes the first water supply path; a second water supply path for supplying water from the outside of the electrical discharge machine to an ion exchange portion having an ion exchange resin provided on the electrical discharge machine; a second valve that opens and closes the second water supply path; as well as a circulation path for conveying the machining fluid from the ion exchange unit to the clean water tank, The control method comprises: A resistivity value obtaining step of obtaining the resistivity value of the processing fluid; A sewage tank water level obtaining step of obtaining the water level of the sewage tank; a processing tank water level obtaining step of obtaining the water level of the processing tank; and A control step of opening and closing the first valve and the second valve according to the resistivity value, the water level of the sewage tank and the water level of the processing tank.

6. The control method of the water supply device according to claim 5, characterized in that: The control step performs the following control: When the water level is lower than a specified water level, the opening time of the first valve and the second valve are set according to the resistivity value and the water level. controlling the first valve and the second valve so that one of the first valve and the second valve is opened and the other is closed, Then, when the opening time set for one of the first valve and the second valve has elapsed, one of the first valve and the second valve is closed and the other is opened, Thereafter, when the opening time set for the other of the first valve and the second valve has elapsed, the other of the first valve and the second valve is closed.

7. The control method of the water supply device according to claim 5, characterized in that: The control step performs the following control: When the water level is lower than a specified water level, the respective openings of the first valve and the second valve and the common opening time of the first valve and the second valve are set according to the resistivity value and the water level; controlling the first valve and the second valve so that the first valve is opened at a set opening degree and the second valve is opened at a set opening degree, Thereafter, when the set opening time has passed, the first valve and the second valve are closed.

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