Water supply system and control method for the water supply system

Abstract

According to an aspect of the present disclosure, a water supplying device (16) automatically supplies water to a wire discharge working machine (10), and includes: a first water supplying path (50) for supplying water from outside of the wire discharge working machine (10) to a pure water tank (22) of the wire discharge working machine (10); a first valve (52) for opening / closing the first water supply path (50); a second water supplying path (56) for supplying water from outside of the wire discharge working machine (10) to an ion exchange unit (24); a second valve (58) for opening / closing the second water supply path (56); and a circulation path (40) for sending a working liquid from the ion exchange unit (24) to the pure water tank (22).

Description

Technical Field

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

Background Art

[0002] Japanese Utility Model Publication No. 5-002816 discloses a machining fluid supply device for a wire electrical discharge machining machine. When the machining fluid in the wire electrical discharge machining machine decreases, the machining fluid supply device automatically supplies tap water.

Summary of the Invention

[0003] When tap water is added to the machining fluid, the specific resistance 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 specific resistance value of the machining fluid. Recently, a better water supply device and a control method for the water supply device have been eagerly awaited.

[0004] A first aspect of the present disclosure is a water supply device that automatically supplies water to an electric discharge machining machine. The water supply device includes a first water supply path that supplies water from outside the electric discharge machining machine to at least one of a clean water tank, a dirty water tank, and a machining tank of the electric discharge machining machine, a first valve that opens and closes the first water supply path, a second water supply path that supplies water from outside the electric discharge machining machine to an ion exchange unit having an ion exchange resin provided in the electric discharge machining machine, a second valve that opens and closes the second supply path, and a circulation path that sends the machining fluid from the ion exchange unit to the clean water tank.

[0005] A second aspect of the present disclosure is a control method for a water supply device that automatically supplies water to an electrical discharge machining machine, the water supply device comprising: a first water supply path that supplies water from outside the electrical discharge machining machine to at least one of the clean water tank, wastewater tank and processing tank of the electrical discharge machining machine; a first valve that opens and closes the first water supply path; a second water supply path that supplies water from outside the electrical discharge machining machine to an ion exchange section having an ion exchange resin provided in the electrical discharge machining machine; a second valve that opens and closes the second supply path; and a circulation path that sends processing fluid from the ion exchange section to the clean water tank, the control method comprising: a resistivity value acquisition step of acquiring the resistivity value of the processing fluid; a wastewater tank water level acquisition step of acquiring the water level of the wastewater tank; a processing tank water level acquisition step of acquiring the water level of the processing tank; and a control step of opening and closing the first valve and the second valve based on the resistivity value, the water level of the wastewater tank and the water level of the processing tank. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a schematic diagram of a wire electrical discharge machining (EDM) machine. [Figure 2] Figure 2 is a block diagram of the water supply control unit. [Figure 3] Figure 3 is a flowchart showing the water supply control process performed in the water supply control unit. [Figure 4] Figure 4 is a flowchart showing the water supply control process performed in the water supply control unit. [Figure 5] Figure 5 is a flowchart showing the water supply control process performed in the water supply control unit. [Figure 6] Figure 6 is a schematic diagram of a wire electrical discharge machining (EDM) machine. [Figure 7] Figure 7 is a schematic diagram of a wire electrical discharge machining (EDM) machine. [Modes for carrying out the invention]

[0007] When the machining fluid in an electrical discharge machining (EDM) machine decreases, water is supplied to the machine from an external source. When water is added to the machining fluid, its resistivity [Ωm] decreases. Therefore, before starting EDM, it is necessary to circulate the machining fluid between a clean water tank and an ion exchange resin to increase its resistivity [Ωm]. As a result, there is a problem that the time between adding water to the machining fluid and starting EDM becomes longer. This disclosure aims to shorten the time between adding water to the machining fluid and starting EDM.

[0008] In this disclosure, resistivity [Ωm] is used for explanation, but conductivity [S / m] may be used instead of resistivity [Ωm]. When water is added to the processing fluid, the conductivity [S / m] of the processing fluid increases. Conductivity [S / m] is the reciprocal of resistivity [Ωm]. In other words, increasing resistivity [Ωm] is equivalent to decreasing conductivity [S / m].

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

[0010] The machine body 12 has a machining tank 18. The machine body 12 performs electrical discharge machining on a workpiece with machining fluid stored in the machining tank 18.

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

[0012] The wastewater tank 20 is connected to the processing tank 18 via a drainage path 28. Processing fluid is discharged from the processing tank 18 into the wastewater tank 20. The processing fluid discharged from the processing tank 18 into the wastewater tank 20 contains sludge and other debris generated during the electrical discharge machining of the workpiece.

[0013] The wastewater tank 20 is connected to the clean water tank 22 via a filtration path 30. The filtration path 30 is equipped with a first pump 32 and a filter 34. The first pump 32 draws up the processing fluid from the wastewater tank 20 and sends it to the clean water tank 22. The filter 34 filters the processing fluid sent from the wastewater tank 20 to the clean water tank 22, removing sludge and other contaminants from the processing fluid.

[0014] A wastewater tank 20 is equipped with a wastewater tank water level measuring unit 36. The wastewater tank water level measuring unit 36 ​​measures the water level of the processing fluid stored in the wastewater tank 20.

[0015] The processing tank 18 is equipped with a processing tank water level measuring unit 37. The processing tank water level measuring unit 37 measures the water level of the processing fluid stored in the processing 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. The first circulation path 38 is provided with a second pump 42 and a circulation valve 44. The processing fluid from the clean water tank 22 is sent to the ion exchange unit 24 via the first circulation path 38. The processing fluid that has passed through the ion exchange resin inside the ion exchange unit 24 is returned to the clean water tank 22 via the second circulation path 40. The second circulation path 40 corresponds to the circulation circuit of the present invention.

[0017] A resistivity measuring unit 46 is provided in the clean water tank 22. The resistivity measuring unit 46 measures the resistivity [Ωm] of the processing 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 processing fluid between the clean water tank 22 and the ion exchange unit 24. The ion exchange resin exchanges ions contained in the processing fluid passing through it with other ions. This increases the resistivity [Ωm] of the processing fluid.

[0019] The processing tank 18 is connected to the clean water tank 22 by a processing fluid supply path 48. The processing tank 18 is supplied with a processing fluid whose resistivity [Ωm] has been adjusted.

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

[0021] The machining fluid treatment control unit 26 controls the circulation valve 44 based on the specific resistance value [Ωm] of the machining fluid in the clean water tank 22. By controlling the opening degree or the opening time of the circulation valve 44 by the machining fluid treatment control unit 26, the specific resistance value [Ωm] of the machining fluid in the clean water tank 22 is maintained at a predetermined value. Note that the function of the machining fluid treatment control unit 26 may be incorporated into the numerical control device that controls the machine tool body 12.

[0022] The water supply device 16 has 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. Through the first water supply path 50, tap water is supplied from the outside of the wire electrical discharge machining machine 10 to the clean water tank 22. A first valve 52 is provided in 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, the machining fluid in the clean water tank 22 flows over the partition plate 54 between the clean water tank 22 and the waste water tank 20 and into the waste water tank 20.

[0024] The second water supply path 56 is connected to the ion exchange section 24. Through the second water supply path 56, tap water is supplied from the outside of the wire electrical discharge machining machine 10 to the ion exchange section 24. A second valve 58 is provided in the second water supply path 56. The second valve 58 adjusts the amount of tap water supplied to the ion exchange section 24.

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

[0026] The water supply control unit 60 controls the first valve 52 and the second valve 58 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22 and the water level in the wastewater tank 20. The water supply control process performed by the water supply control unit 60 will be described in detail later. The functions of the water supply control unit 60 may also be incorporated into a numerical control device that controls the processing machine body 12.

[0027] [Configuration of the water supply control unit] Figure 2 is a block diagram of the water supply control unit 60. The water supply control unit 60 has a calculation unit 62 and a storage unit 64. The calculation unit 62 is a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The calculation unit 62 has 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 realized by the calculation 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 be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). At least a portion of the resistivity acquisition unit 66, the wastewater tank water level acquisition unit 68, the processing tank water level acquisition unit 69, and the valve control unit 70 may be implemented by an electronic circuit including discrete devices.

[0028] The storage unit 64 is composed of computer-readable storage media, namely volatile memory (not shown) and non-volatile memory (not shown). The volatile memory is, for example, RAM (Random Access Memory). The non-volatile memory is, for example, ROM (Read Only Memory) or flash memory. Data is stored in the volatile memory, for example. Programs, tables, maps, etc., are stored in the non-volatile memory, for example. At least a portion of the storage unit 64 may be provided in the processor, integrated circuit, etc. mentioned above. At least a portion of the storage unit 64 may be mounted on equipment connected to the wire electrical discharge machining machine 10 by a network.

[0029] The resistivity acquisition unit 66 acquires the resistivity of the processing fluid in the clean water tank 22, which is measured by the resistivity 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 processing tank water level acquisition unit 69 acquires the water level of the processing tank 18 measured by the processing 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 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22 and the water level in the wastewater tank 20. As a result, the water level of the processing fluid in the wastewater tank 20 rises. The resistivity [Ωm] of the processing fluid in the clean water tank 22 rises. The valve control unit 70 corresponds to the control unit of the present invention.

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

[0034] In step S1, the valve control unit 70 determines whether the water level in the sewage tank 20, as measured by the sewage tank water level measuring unit 36, is below a predetermined water level. If the water level is below the predetermined water level (step S1: YES), the process proceeds to step S2. If the water level is at or above 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 [Ωm] of the processing fluid in the clean water tank 22, as measured by the resistivity measurement unit 46, is less than a threshold. If the resistivity [Ωm] is less than the threshold (step S2: YES), the process proceeds to step S3. If the resistivity [Ωm] is greater than or equal to the threshold (step S2: NO), the process proceeds to step S4. The threshold may be equal to the predetermined value of the resistivity [Ωm] described above. The threshold may also be less than the predetermined value of the resistivity [Ωm] described above.

[0036] In step S3, the valve control unit 70 controls the first valve 52 to close it. The valve control unit 70 also controls the second valve 58 to open it. Then, the process returns to step S1. If the first valve 52 was closed before the processing in step S3, the first valve 52 remains closed. If the second valve 58 was open before the processing in step S3, the second valve 58 remains open.

[0037] In step S4, the valve control unit 70 controls the first valve 52 to open it. The valve control unit 70 also controls the second valve 58 to close it. Then, the process returns to step S1. If the first valve 52 was open before the processing in step S4, the first valve 52 remains open. If the second valve 58 was closed before the processing in step S4, the second valve 58 remains closed.

[0038] In step S5, the valve control unit 70 controls the first valve 52 to close it. The valve control unit 70 also controls the second valve 58 to close it. After that, the water supply control process ends. If the first valve 52 was closed before the process in step S5, the first valve 52 remains closed. If the second valve 58 was closed before the process in step S5, the second valve 58 remains closed.

[0039] [Effects and Effects] When the machining fluid in the wire electrical discharge machining machine 10 decreases, water is supplied to the clean water tank 22 from outside the wire electrical discharge machining machine 10. When water is added to the machining fluid, the resistivity [Ωm] of the machining fluid decreases. Therefore, before electrical discharge machining starts, it is necessary to circulate the machining fluid between the clean water tank 22 and the ion exchange unit 24 to increase the resistivity [Ωm] of the machining fluid. This results in a problem where the period between the addition of water to the machining fluid and the start of electrical discharge machining becomes longer.

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

[0041] Therefore, the water supply device 16 of this embodiment has a second water supply path 56 that supplies water to the ion exchange unit 24 from outside the wire electrical discharge machining machine 10, in addition to the first water supply path 50 that supplies water to the clean water tank 22 from outside the wire electrical discharge machining machine 10. As a result, when water is supplied to the wire electrical discharge machining machine 10 from outside the wire electrical discharge machining machine 10, the water supply device 16 can shorten the time required to raise the resistivity [Ωm] of the machining fluid to a predetermined value.

[0042] Furthermore, in this embodiment, the water supply device 16 is controlled by the water supply control unit 60 to open and close the first valve 52 and the second valve 58 based on the resistivity [Ωm] of the processing fluid and the water level in the wastewater tank 20. As a result, the water supply device 16 can raise the water level in the wastewater tank 20 while increasing the resistivity [Ωm] of the processing fluid.

[0043] [Second Embodiment] In this embodiment, the content of the water supply control process differs from that of the first embodiment.

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

[0045] In step S11, the valve control unit 70 determines whether the water level in the sewage tank 20, as measured by the sewage tank water level measuring unit 36, is below a predetermined water level. If the water level is below the predetermined water level (step S11: YES), the process proceeds to step S12. If the water level is at or above the predetermined water level (step S11: NO), the water supply control process is terminated.

[0046] In step S12, the valve control unit 70 sets the opening time of the first valve 52 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22, the water level in the wastewater tank 20, and the water level in the processing tank 18. The valve control unit 70 also sets the opening time of the second valve 58 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22, the water level in the wastewater tank 20, and the water level in the processing tank 18. After that, the process proceeds to step S13.

[0047] The opening times of the first valve 52 and the second valve 58 are set based on the difference between the amount of processing fluid currently stored in the wastewater tank 20 and the amount of processing fluid currently stored in the processing tank 18, relative to the capacity of the wastewater tank 20 that can store the processing fluid. This difference may be referred to as the required water supply amount below. The amount of processing fluid currently stored in the wastewater tank 20 is determined from the current water level of the wastewater tank 20 measured by the wastewater tank water level measuring unit 36. The amount of processing fluid currently stored in the processing tank 18 is determined from the current water level of the processing tank 18 measured by the processing tank water level measuring unit 37.

[0048] Furthermore, the opening times of the first valve 52 and the second valve 58 are set based on the difference between the resistivity [Ωm] of the water before it passes through the ion exchange resin of the ion exchange unit 24 and the resistivity [Ωm] of the water after it has passed through the ion exchange resin. This difference may be referred to as the resistivity increase below. The resistivity [Ωm] of the water before it passes through the ion exchange resin of the ion exchange unit 24 and the resistivity [Ωm] of the water after it has passed through the ion exchange resin are measured in advance. The valve control unit 70 sets the opening times of the first valve 52 and the second valve 58 based on the required water supply amount and the resistivity increase so that the resistivity [Ωm] of the processing fluid in the clean water tank 22 approaches a predetermined value.

[0049] In the following, the set opening time of the first valve 52 may be referred to as the first set time. Similarly, the set opening time of the second valve 58 may be referred to as the 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 proceeds to step S14.

[0051] In step S14, the valve control unit 70 determines whether the time the first valve 52 is open (open time) is equal to or greater than the first set time. If the open time of the first valve 52 is equal to or greater than the first set time (step S14: YES), the process proceeds to step S15. If the open time of the first valve 52 is less than the first set time (step S14: NO), the determination in step S14 is repeated.

[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 proceeds 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 proceeds to step S17.

[0054] In step S17, the valve control unit 70 determines whether the time the second valve 58 is open (open time) is equal to or greater than the second set time. If the open time of the second valve 58 is equal to or greater than the second set time (step S17: YES), the process proceeds to step S18. If the open time of the first valve 52 is less than the second set time (step S17: NO), the determination in step S17 is repeated.

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

[0056] [Effects and Effects] In the water supply device 16 of this embodiment, when the water level in the wastewater tank 20 falls below a predetermined level, the water supply control unit 60 sets the opening time of the first valve 52 (first set time) and the opening time of the second valve 58 (second set time) based on the resistivity [Ωm] of the processing fluid in the clean water tank 22 and the water level in the wastewater 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. After the first set time has elapsed, the water supply control unit 60 closes the first valve 52 and opens the second valve 58. After the second set time has elapsed, the water supply control unit 60 closes the second valve 58. As a result, the water supply device 16 can raise the water level in the wastewater tank 20 while increasing the resistivity [Ωm] of the processing fluid.

[0057] [Third Embodiment] In this embodiment, the content of the water supply control process differs from that of the first embodiment.

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

[0059] In step S21, the valve control unit 70 determines whether the water level in the sewage tank 20, as measured by the sewage tank water level measuring unit 36, is below a predetermined water level. If the water level is below the predetermined water level (step S21: YES), the process proceeds to step S22. If the water level is at or above the predetermined water level (step S21: NO), the water supply control process is terminated.

[0060] In step S22, the valve control unit 70 sets the opening degree of the first valve 52 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22, the water level in the wastewater tank 20, and the water level in the processing tank 18. The valve control unit 70 sets the opening degree of the second valve 58 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22, the water level in the wastewater tank 20, and the water level in the processing tank 18. The valve control unit 70 sets a common opening time for the first valve 52 and the second valve 58 based on the resistivity [Ωm] of the processing fluid in the clean water tank 22, the water level in the wastewater tank 20, and the water level in the processing tank 18. After that, the process proceeds 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 processing fluid currently stored in the wastewater tank 20 and the amount of processing fluid currently stored in the processing tank 18, relative to the capacity of the wastewater tank 20 that can store the processing fluid. This difference may be referred to as the required water supply amount below. The amount of processing fluid currently stored in the wastewater tank 20 is determined from the current water level of the wastewater tank 20 measured by the wastewater tank water level measuring unit 36. The amount of processing fluid currently stored in the processing tank 18 is determined from the current water level of the processing tank 18 measured by the processing tank water level measuring unit 37.

[0062] Furthermore, 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 resistivity [Ωm] of the water before it passes through the ion exchange resin of the ion exchange unit 24 and the resistivity [Ωm] of the water after it passes through the ion exchange resin. This difference may be referred to as the resistivity increase below. The resistivity [Ωm] of the water before it passes through the ion exchange resin of the ion exchange unit 24 and the resistivity [Ωm] of the water after it passes through the ion exchange resin are measured in advance. The valve control unit 70 sets the opening degree of the first valve 52, the opening degree of the second valve 58, and the opening time based on the required water supply amount and the resistivity increase so that the resistivity [Ωm] of the processing fluid in the clean water tank 22 approaches a predetermined value.

[0063] In the following, the common opening time of the first valve 52 and the second valve 58 may be referred to 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 opened to the degree set in step S22. The second valve 58 is opened to the degree set in step S22. After that, the process proceeds to step S24.

[0065] In step S24, the valve control unit 70 determines whether the time the first valve 52 and the second valve 58 are open (open time) is equal to or greater than the set time. If the open time of the first valve 52 and the second valve 58 is equal to or greater than the set time (step S24: YES), the process proceeds to step S25. If the open time of the first valve 52 and the second valve 58 is less than the set time (step S24: NO), the determination in step S24 is repeated.

[0066] In step S25, the valve control unit 70 closes the first valve 52 and the second valve 58. After that, the water supply control process is terminated.

[0067] [Effects and Effects] In the water supply device 16 of this embodiment, when the water level in the wastewater tank 20 falls below a predetermined level, the water supply control unit 60 sets the opening degree of the first valve 52, the opening degree of the second valve 58, and a common opening time for the first valve 52 and the second valve 58, based on the resistivity [Ωm] of the processing fluid in the clean water tank 22 and the water level in the wastewater tank 20. The water supply control unit 60 opens the first valve 52 to the set opening degree. The water supply control unit 60 also opens the second valve 58 to the set opening degree. After the set opening time has elapsed, the water supply control unit 60 closes the first valve 52 and the second valve 58. As a result, the water supply device 16 can raise the water level in the wastewater tank 20 while increasing the resistivity [Ωm] of the processing fluid.

[0068] [Variation] In the first to third embodiments, the first water supply route 50 is connected to the clean water tank 22. Alternatively, the first water supply route 50 may be connected to the wastewater tank 20 or the processing tank 18.

[0069] Figure 6 is a schematic diagram of the wire electrical discharge machining machine 10. A first water supply route 50 is connected to the wastewater tank 20. Tap water is supplied to the wastewater tank 20 from outside the wire electrical discharge machining machine 10 via the first water supply route 50.

[0070] Figure 7 is a schematic diagram of a wire electrical discharge machining (EDM) machine 10. A first water supply route 50 is connected to the machining tank 18. Tap water is supplied to the machining tank 18 from outside the wire electrical discharge machining machine 10 via the first water supply route 50.

[0071] The following additional information is disclosed regarding the above embodiments and modifications.

[0072] (Note 1) A water supply device (16) for automatically supplying water to an electrical discharge machining machine (10) comprises: a first water supply path (50) that supplies water from outside the electrical discharge machining machine to at least one of the clean water tank (22), wastewater tank (20), and processing tank (18) of the electrical discharge machining machine; a first valve (52) that opens and closes the first water supply path; a second water supply path (56) that supplies water from outside the electrical discharge machining machine to an ion exchange unit (24) having an ion exchange resin provided in the electrical discharge machining machine; a second valve (58) that opens and closes the second supply path; and a circulation path (40) that sends processing fluid from the ion exchange unit to the clean water tank. As a result, when water is supplied to the electrical discharge machining machine from outside the electrical discharge machining machine, the water supply device can shorten the time required to raise the resistivity of the processing fluid to a predetermined 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 processing fluid, a wastewater tank water level acquisition unit (68) for acquiring the water level of the wastewater 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 based on the resistivity value, the water level of the wastewater tank, and the water level of the processing tank. This allows the water supply device to raise the resistivity value of the processing fluid while raising the water level of the wastewater tank.

[0074] (Note 3) In the water supply device described in Appendix 2, the control unit is the Sewage tank When the water level falls below a predetermined level, the resistivity value , the water level of the sewage tank and the above Processing tank Based on the water level, the opening times of the first valve and the second valve may be set, and the first valve and the second valve may be controlled to open one of the first valve and close the other, and then, after the set opening time for one of the first valve and the second valve has elapsed, one of the first valve and the second valve may be closed and the other opened, and then, after the set opening time for the other of the first valve and the second valve has elapsed, the other of the first valve and the second valve may be closed. In this way, the water supply device can raise the water level in the wastewater tank while increasing the resistivity of the processing fluid.

[0075] (Note 4) In the water supply device described in Appendix 2, the control unit is the Sewage tank When the water level falls below a predetermined level, the resistivity value , the water level of the sewage tank and the above Processing tank Based on the water level, the opening degree of the first valve and the second valve, and a common opening time for the first valve and the second valve may be set. The first valve and the second valve may be controlled to open the first valve to the set opening degree and the second valve to the set opening degree, and then, after the set opening time has elapsed, the first valve and the second valve may be closed. In this way, the water supply device can raise the water level in the wastewater tank while increasing the resistivity of the processing fluid.

[0076] (Note 5) A control method for a water supply device that automatically supplies water to an electrical discharge machining (EDM) machine, wherein the water supply device comprises: a first water supply path that supplies water from outside the EDM machine to at least one of the clean water tank, wastewater tank, and processing tank of the EDM machine; a first valve that opens and closes the first water supply path; a second water supply path that supplies water from outside the EDM machine to an ion exchange section having an ion exchange resin provided in the EDM machine; a second valve that opens and closes the second supply path; and a circulation path that sends processing fluid from the ion exchange section to the clean water tank, wherein the control method comprises: a resistivity value acquisition step of acquiring the resistivity value of the processing fluid; a wastewater tank water level acquisition step of acquiring the water level of the wastewater tank; a processing tank water level acquisition step of acquiring the water level of the processing tank; and a control step of opening and closing the first valve and the second valve based on the resistivity value, the water level of the wastewater tank, and the water level of the processing tank. As a result, the water supply device can raise the water level of the wastewater tank while increasing the resistivity value of the processing fluid.

[0077] (Note 6) In the water supply device control method described in Appendix 5, the control step is as described above Sewage tank When the water level falls below a predetermined level, the resistivity value , the water level of the sewage tank and the above Processing tank Based on the water level, the opening times of the first valve and the second valve may be set, and the first valve and the second valve may be controlled to open one of the first valve and close the other, and then, after the set opening time for one of the first valve and the second valve has elapsed, one of the first valve and the second valve may be closed and the other opened, and then, after the set opening time for the other of the first valve and the second valve has elapsed, the other of the first valve and the second valve may be closed. In this way, the water supply device can raise the water level in the wastewater tank while increasing the resistivity of the processing fluid.

[0078] (Note 7) In the water supply device control method described in Appendix 5, the control step is as described above Sewage tank When the water level falls below a predetermined level, the resistivity value , the water level of the sewage tank and the above Processing tankBased on the water level, the opening degree of the first valve and the second valve, and a common opening time for the first valve and the second valve may be set. The first valve and the second valve may be controlled to open the first valve to the set opening degree and the second valve to the set opening degree, and then, after the set opening time has elapsed, the first valve and the second valve may be closed. In this way, the water supply device can raise the water level in the wastewater tank while increasing the resistivity of the processing fluid.

[0079] While embodiments of this disclosure have been described in detail, this disclosure is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the spirit of the invention or the idea and spirit of the invention derived from the claims and their equivalents. For example, the order of operations and processes in the embodiments described above are shown as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0080] 10…Wire electrical discharge machining (EDM) machine 16...Water supply device 18...Processing tank 20...Sewage tank 22...Clean water tank 24...Ion exchange section 40...Second circulation pathway (circulation pathway) 50...First water supply route 52...First valve 56...Second water supply route 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 that automatically supplies water to an electrical discharge machining machine, A first water supply route that supplies water from outside the electrical discharge machining machine to at least one of the clean water tank, wastewater tank, and processing tank of the electrical discharge machining machine, A first valve for opening and closing the first water supply path, A second water supply path supplies water from outside the electrical discharge machine to an ion exchange section having an ion exchange resin provided in the electrical discharge machine, A second valve for opening and closing the second water supply path, A circulation path for sending the processing liquid from the ion exchange unit to the clean water tank, A water supply device having the following features.

2. In the water supply device according to claim 1, A resistivity value acquisition unit for acquiring the resistivity value of the processing fluid, A wastewater tank water level acquisition unit that acquires the water level of the wastewater tank, A processing tank water level acquisition unit that acquires the water level of the processing tank, A control unit that opens and closes the first valve and the second valve based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank, A water supply device having the following features.

3. In the water supply device according to claim 2, The control unit, If the water level in the wastewater tank falls below a predetermined level, the opening times of the first valve and the second valve are set based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank. Control the first valve and the second valve to open one of the first valve and the second valve and close the other. Subsequently, when the set opening time 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. A water supply device that then closes the other of the first valve and the second valve after a set opening time has elapsed for the other of the first valve and the second valve.

4. In the water supply device according to claim 2, The control unit, If the water level in the wastewater tank falls below a predetermined level, the opening degree of the first valve and the second valve, and a common opening time for the first valve and the second valve are set based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank. The first valve and the second valve are controlled to open the first valve to a set opening and the second valve to a set opening. A water supply device that then closes the first valve and the second valve after a set open time has elapsed.

5. A control method for a water supply device that automatically supplies water to an electrical discharge machining machine, The water supply device is A first water supply route that supplies water from outside the electrical discharge machining machine to at least one of the clean water tank, wastewater tank, and processing tank of the electrical discharge machining machine, A first valve for opening and closing the first water supply path, A second water supply path supplies water from outside the electrical discharge machine to an ion exchange section having an ion exchange resin provided in the electrical discharge machine, A second valve for opening and closing the second water supply path, A circulation path for sending the processing liquid from the ion exchange unit to the clean water tank, It has, A resistivity acquisition step to obtain the resistivity value of the processing fluid, A wastewater tank water level acquisition step to acquire the water level of the wastewater tank, A processing tank water level acquisition step to acquire the water level of the processing tank, A control step of opening and closing the first valve and the second valve based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank, A method for controlling a water supply system, comprising the following features.

6. In the water supply device control method described in claim 5, The control step described above is: If the water level in the wastewater tank falls below a predetermined level, the opening times of the first valve and the second valve are set based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank. Control the first valve and the second valve to open one of the first valve and the second valve and close the other. Subsequently, when the set opening time 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. A control method for a water supply device, wherein, after a set opening time has elapsed for the other of the first valve and the second valve, the other of the first valve and the second valve is closed.

7. In the water supply device control method described in claim 5, The control step described above is: If the water level in the wastewater tank falls below a predetermined level, the opening degree of the first valve and the second valve, and a common opening time for the first valve and the second valve are set based on the resistivity value, the water level in the wastewater tank, and the water level in the processing tank. The first valve and the second valve are controlled to open the first valve to a set opening and the second valve to a set opening. A method for controlling a water supply device, wherein the first valve and the second valve are closed after a set open time has elapsed.

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