Water circulation system and control method for electric spark wire cutting machine

Abstract

The water circulation system and control method for the electric spark wire cutting machine include a workbench, a guide assembly, a processing water tank, a water wire separation assembly, an ultra-clear water tank, a clean water tank, and a sewage tank that cooperate with each other; the electrode wire passes through the workbench, the guide assembly, and the water wire separation assembly in sequence and enters the waste wire barrel; the water circulation system is connected to the processing water tank, the ultra-clear water tank, the clean water tank, and the sewage tank through various components; it includes a jet pump system, a liquid delivery pump system, and a circulation pump system that cooperate with each other; it can save energy, improve work efficiency and the accuracy of workpiece processing.

Description

Technical Field

[0001] The invention belongs to the field of electric spark wire cutting machines and relates to a water circulation system and a control method for the electric spark wire cutting machines. Background Art

[0002] The existing wire-cut EDM includes a workbench, a guide assembly, a processing water tank, a water-wire separation assembly, an ultra-clear water tank, a clean water tank, and a sewage tank that cooperate with each other. The electrode wire passes through the workbench, the guide assembly, and the water-wire separation assembly in sequence and enters the waste wire bucket. The water circulation system connects the processing water tank, the ultra-clear water tank, the clean water tank, and the sewage tank through various components. It includes a jet pump system, a liquid delivery pump system, and a circulation pump system that cooperate with each other. The problems existing in its operation are:

[0003] 1. In the existing wire-cut EDM, only the jet pump adopts variable frequency control, while the circulation pump used for machining fluid circulation and the liquid delivery pump used in the liquid delivery system still operate at a fixed frequency, using the natural frequency. In fact, the circulation system and the liquid delivery system do not need to work at full frequency, resulting in waste of electricity consumption.

[0004] 2. The existing wire EDM is not equipped with a liquid level control system. The temperature of the workbench changes due to the liquid temperature, affecting the processing accuracy.

[0005] 3. The existing automatic rust removal device of the electric spark wire cutting machine is not equipped with a concentration control system. As long as this function is turned on, the automatic rust removal system will always be running, resulting in excessive waste of automatic rust removal powder. Summary of the Invention

[0006] The purpose of the present invention is to provide a water circulation system and control method for a wire-cut electric discharge machine, which can save energy, improve work efficiency and the accuracy of workpiece processing.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The water circulation system for the electric spark wire cutting machine includes a workbench, a guide assembly, a processing water tank, a water wire separation assembly, an ultra-clear water tank, a clean water tank, and a sewage tank that cooperate with each other; the electrode wire passes through the workbench, the guide assembly, and the water wire separation assembly in sequence and enters the waste wire barrel; the water circulation system is connected to the processing water tank, the ultra-clear water tank, the clean water tank, and the sewage tank through various components; and includes a jet pump system, a liquid delivery pump system, and a circulation pump system that cooperate with each other; wherein:

[0009] The jet pump system includes: a jet pump equipped with a jet pump frequency converter, which is installed in the ultra-clear water tank. The jet pump is connected to two branches; one branch is connected to the parallel automatic threading water spray solenoid valve, high-pressure control solenoid valve, and low-pressure control solenoid valve, and the three solenoid valves are connected to the guide assembly; the other branch is connected to the water silk separator solenoid valve, and then connected to the water silk separator suction pump, and the sewage separated by the water silk separator is sent to the sewage tank through the suction pump;

[0010] The liquid feeding pump system includes: a liquid feeding pump provided with a liquid feeding pump frequency converter in the clean water tank, the liquid feeding pump is connected to four branches, the first branch is connected to the liquid temperature control system in the ultra-clear water tank; the second branch is connected to the liquid level control system; the third branch is connected to the conductivity control system in the clean water tank; and the fourth branch is connected to the concentration detection system in the clean water tank;

[0011] The circulating pump system includes: a circulating pump provided with a circulating pump frequency converter in the sewage tank, the circulating pump is connected to two branches, one branch is connected to the filtration system in the ultra-clear water tank; the other branch is connected to the liquid level control system;

[0012] Furthermore, the liquid temperature regulating system includes a liquid temperature sensor connected to the liquid feeding pump, and the liquid temperature sensor is connected to a liquid temperature regulating air conditioner arranged in the ultra-clear water tank.

[0013] Furthermore, the liquid level adjustment system includes three branches. The first branch is responsible for adding liquid when the machine is started and replenishing liquid when the liquid level is lower than the lower limit during processing, including an emergency solenoid valve 1 connected to the liquid feeding pump, and the emergency solenoid valve 1 is connected to the float switch position in the processing tank, which is responsible for adding liquid to the processing tank when the machine is started; the second branch is responsible for emergency delivery before processing, including an emergency solenoid valve 1 connected to the liquid feeding pump, and an emergency solenoid valve 2 connected to the circulation pump, and the emergency solenoid valve 1 and the emergency solenoid valve 2 are respectively connected to the processing tank to ensure that the liquid level before processing is between the upper and lower limit switches above the processing tank; the third branch is responsible for intermediate liquid level adjustment, including an intermediate liquid level solenoid valve connected to the liquid feeding pump, and the intermediate liquid level solenoid valve is connected to the processing tank to ensure that the liquid level during processing is between the upper and lower limit switches above the processing tank.

[0014] Furthermore, the conductivity control system includes a conductivity control solenoid valve connected to the liquid feeding pump, the conductivity control solenoid valve is connected to the ion resin barrel in the clean water tank, and the conductivity control solenoid valve is also connected to the conductivity sensor.

[0015] Furthermore, the concentration detection system includes: a concentration meter controlling an electromagnetic valve connected to the liquid delivery pump, the concentration meter controlling the electromagnetic valve is connected to the concentration detection system and the filter respectively, the filter is connected to the rust removal powder placement barrel, and the rust removal powder placement barrel is connected to the clean water tank through a constant flow valve.

[0016] Furthermore, the filtration system includes a filter barrel solenoid valve connected to the circulation pump, the filter barrel solenoid valve is connected to the filter barrel set in the ultra-clear water tank, and the filter barrel solenoid valve is further connected to a pressure sensor.

[0017] Furthermore, the control method of the jet pump system is:

[0018] The jet pump system is responsible for the supply of jet fluid for roughing / finishing, guiding the electrode wire during automatic threading, removing moisture during electrode wire discharge, and cleaning the wire guide die:

[0019] During automatic wire threading, the water spray solenoid valve for automatic wire threading is opened, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly, so that the electrode wire is guided from the upper guide to the lower guide, completing the wire threading, and the water finally flows to the processing tank.

[0020] The wire guide die cleaning function completes the processing, and the low-pressure control solenoid valve opens. The jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly to complete the wire guide die cleaning and prepare for the next processing. The water finally flows to the processing tank.

[0021] During machining, the first and second cuts, i.e. rough machining, are carried out first. The high-pressure solenoid valve is turned on and the jet pump operates at a frequency of 63Hz to remove a large amount of discharge generated during machining, thereby increasing machining speed and effectively preventing wire breakage. The water eventually flows into the machining tank.

[0022] During machining, the third and fourth machining processes, i.e., finishing, are carried out. The low-pressure solenoid valve is opened and the jet pump operates at a frequency of 30Hz to remove the discharge generated during finishing, improve the quality of the machined surface, and effectively prevent wire breakage. The water eventually flows to the machining tank.

[0023] During processing, when the electrode wire is discharged, the water-wire separation solenoid valve opens, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly. Under the action of the suction pump, the water and the electrode wire are mixed and separated through the water-wire separator, thereby removing the residual moisture in the electrode wire. The electrode wire flows to the waste wire barrel, and the water finally flows to the sewage tank.

[0024] Furthermore, the control method of the liquid delivery pump system is:

[0025] The liquid delivery pump system is responsible for liquid temperature regulation, air conditioning circulation, conductivity system liquid delivery, and together with the circulation pump, is responsible for liquid level regulation, rust removal device liquid supply, and workbench preheating treatment liquid delivery:

[0026] The liquid temperature regulates the air conditioning cycle, and the water eventually flows to the ultra-clear water tank;

[0027] Conductivity system liquid delivery: When the conductivity sensor senses that the conductivity value of the water tank is low, the conductivity control solenoid valve opens and delivers liquid to the ion resin barrel, and the water eventually flows to the clean water tank;

[0028] Liquid level adjustment: When the machine is turned on, the emergency solenoid valve opens at a frequency of 30Hz, and liquid is fed to the processing tank until it stops at the float switch, which ensures that the temperature change of the work surface is minimized during processing. During processing, the intermediate liquid level is replenished. In order to maintain the processing, the intermediate liquid level solenoid valve opens to prevent processing interruption due to leakage from the processing tank. During processing, when the liquid level falls below the lower limit, the emergency solenoid valve opens to feed liquid to the middle position of the liquid level switch. During processing, some water in the gap between the processing tanks will leak into the sewage tank. When the signal at the middle position of the liquid level switch disappears, the intermediate liquid level solenoid valve opens, and the liquid feed pump feeds liquid. When the liquid level reaches the middle position, the signal opens and the solenoid valve closes.

[0029] The rust removal device supplies liquid. When the concentration detection system detects that the rust removal powder concentration in the clean water tank is lower than the set value, the concentration meter controls the solenoid valve to open, and the water eventually flows to the clean water tank;

[0030] Further, the control method of the circulation pump system:

[0031] The circulating pump system is responsible for sewage filtration and, together with the liquid delivery pump, is responsible for liquid level regulation:

[0032] When sewage is filtered, the normally open filter barrel solenoid valve is closed, and the pressure is sensed by the pressure sensor at the filter, thereby controlling the frequency of the circulating pump inverter.

[0033] Liquid level adjustment: When the machine is turned on, the second rapid liquid delivery solenoid valve is opened and the normally open filter barrel solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid to the processing tank together until it stops at the float switch; during processing, when the processing liquid level is lower than the lower limit, the second rapid liquid delivery solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid together to the middle position of the liquid level switch.

[0034] By adopting the above technical solution, the present invention has the following advantages:

[0035] The circulating pump is controlled by a frequency converter and equipped with a pressure sensor. The pressure changes of the pressure sensor are fed back to the control system to control the operating frequency of the frequency converter, thus saving electricity.

[0036] The liquid delivery pump is controlled by a frequency converter, and the frequency of the frequency converter is reduced to 60-70%, thereby reducing unnecessary energy consumption.

[0037] An independent concentration detection device has been developed in the rust removal system to monitor the concentration of the rust remover in the storage tank in real time, thereby reducing the use of rust removal powder.

[0038] By adding a liquid level control system and preserving machining fluid in the machining tank during the preparatory phase of the process, such as setting the workpiece position, temperature fluctuations on the machine can be suppressed. This improves the accuracy of the work surface due to temperature fluctuations on the liquid, thereby enhancing machining accuracy. By preserving machining fluid, the time required to deliver fluid at the start of machining can be shortened, improving preparation efficiency. Furthermore, the frequency of the liquid temperature control air conditioner activation can be reduced, thereby reducing power consumption.

[0039] During machining, the jet system, depending on the machining conditions (high-pressure jet or low-pressure jet), flows from the ultra-clean water tank into the processing tank. Approximately 30 liters / min of clean water is also flowing from the liquid delivery pump, resulting in an excess of water in the processing tank. In this case, the control system can use the jet pump's output frequency to control the liquid delivery pump's inverter frequency conversion value (approximately 70-85%). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 This is a diagram of a water circulation frequency conversion control system for a wire-cut electric discharge machine according to the present invention;

[0042] Figure 2 This is a diagram of the frequency conversion control system of the circulation pump and the liquid delivery pump during urgent delivery of the present invention;

[0043] Figure 3 This is a diagram of the frequency conversion control system of the circulation pump and the liquid delivery pump when the present invention is in standby mode;

[0044] Figure 4 When processing for the present invention, the circulating pump, liquid feeding pump, and jet pump frequency conversion control system diagram;

[0045] Figure 5 This is the control diagram of the frequency conversion system for urgent delivery of the present invention;

[0046] Figure 6 This is a schematic diagram of a circulating liquid feeding system in standby mode according to the prior art of the present invention;

[0047] Figure 7 This is a schematic diagram of the circulating liquid feeding system of the present invention when in standby mode;

[0048] Figure 8 This is a diagram of the circulation, jet and liquid feeding system during processing according to the prior art of the present invention;

[0049] Figure 9 This is a diagram of the circulation, jetting, and liquid delivery systems during processing of the present invention; DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are preferred embodiments of the present invention and should not be regarded as excluding other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] Reference Figure 1-9 , which is a specific embodiment of the present invention.

[0052] The water circulation system for the electric spark wire cutting machine includes a workbench 1, a guide assembly 2 (including an upper guide 21 and a lower guide 22), a processing water tank 3, a water wire separation assembly 4 (including a roller 41, a water wire separator 42, a waste wire bucket 43, and an air suction pump 44), an ultra-clear water tank 5, a clean water tank 6, and a sewage tank 7 that cooperate with each other; the electrode wire 8 passes through the workbench 1, the guide assembly 2, and the water wire separation assembly 3 in sequence and enters the waste wire bucket 43; the water circulation system 9 is connected to the processing water tank 3, the ultra-clear water tank 5, the clean water tank 6, and the sewage tank 7 through various components; and includes a jet pump system 91, a liquid delivery pump system 92, and a circulation pump system 93 that cooperate with each other; wherein:

[0053] The jet pump system 91 includes a jet pump 912 provided in an ultra-clear water tank and equipped with a jet pump frequency converter 911. The jet pump is connected to two branches: one branch is connected to a parallel automatic threading water spray solenoid valve 913, a high-pressure control solenoid valve 914, and a low-pressure control solenoid valve 915, and these three solenoid valves are respectively connected to the guide assembly 2; the other branch is connected to a water silk separator solenoid valve 916, and further connected to the water silk separator 42 and the suction pump 44. The suction pump 44 delivers the wastewater separated by the water silk separator 42 to the wastewater tank 7.

[0054] The liquid feeding pump system 92 includes: a liquid feeding pump 922 provided in the clean water tank and equipped with a liquid feeding pump frequency converter 921. The liquid feeding pump is connected to four branches. The first branch is connected to the liquid temperature control system 923 provided in the ultra-clear water tank 5; the second branch is connected to the liquid level control system 924; the third branch is connected to the conductivity control system 925 provided in the clean water tank 6; and the fourth branch is connected to the concentration detection system 926 in the clean water tank 6.

[0055] The circulation pump system 93 includes a circulation pump 932 provided in the sewage tank and equipped with a circulation pump inverter 931. The circulation pump is connected to two branches, one of which is connected to the filtration system 933 in the ultra-clear water tank 5; the other is connected to the liquid level control system 924.

[0056] Furthermore, the liquid temperature regulating system 923 includes a liquid temperature sensor 9231 connected to the liquid delivery pump, and the liquid temperature sensor is connected to a liquid temperature regulating air conditioner 9232 provided in the ultra-clear water tank.

[0057] Furthermore, the liquid level regulating system includes three branches. The first branch is responsible for adding liquid when the machine is started and replenishing liquid when the liquid level is lower than the lower limit during processing, including a quick-feed solenoid valve 9242 connected to the liquid feeding pump 922. The quick-feed solenoid valve 9242 is connected to the processing tank 3 and is responsible for adding liquid to the position of the float switch 31 in the processing tank when the machine is started, and replenishing liquid when the liquid level is lower than the lower limit 34 during processing; the second branch is responsible for quick delivery before processing, including a quick-feed solenoid valve 9242 connected to the liquid feeding pump 922 and connected to the circulation The emergency solenoid valve 2 9243 connected to the pump 932, the emergency solenoid valve 1 9242 and the emergency solenoid valve 2 9243 are respectively connected to the processing tank 3 to ensure that the liquid level before processing is between the upper and lower limit switches above the processing tank; the third branch is responsible for the intermediate liquid level adjustment, including the intermediate liquid level solenoid valve 9241 connected to the liquid feeding pump 922, the intermediate liquid level solenoid valve 9241 is connected to the processing tank 3 to ensure that the liquid level during processing is between the upper and lower limit switches 33 and 34 above the processing tank.

[0058] Furthermore, the conductivity control system 925 includes a conductivity control solenoid valve 9251 connected to the liquid delivery pump 922 , the conductivity control solenoid valve is connected to the ion resin barrel 9252 in the clean water tank 6 , and the conductivity control solenoid valve is also connected to a conductivity sensor 9253 .

[0059] Furthermore, the concentration detection system 926 includes: a concentration meter control solenoid valve 9261 connected to the liquid delivery pump 922, the concentration meter control solenoid valve is respectively connected to the concentration detection system 9262 and the filter 9263, the filter is connected to the rust removal powder placement barrel 9264, and the rust removal powder placement barrel is connected to the clean water tank 6 through the constant flow valve 9265.

[0060] Furthermore, the filtration system 933 includes a filter barrel solenoid valve 9331 connected to the circulation pump 932 , the filter barrel solenoid valve is connected to the filter barrel 9332 set in the ultra-clear water tank, and the filter barrel solenoid valve is further connected to the pressure sensor 9333 .

[0061] Control method of jet pump system:

[0062] The jet pump system is responsible for the supply of jet fluid for roughing / finishing, guiding the electrode wire during automatic threading, removing moisture during electrode wire discharge, and cleaning the wire guide die:

[0063] During automatic wire threading, the water spray solenoid valve for automatic wire threading is opened, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly, so that the electrode wire is guided from the upper guide to the lower guide, completing the wire threading, and the water finally flows to the processing tank.

[0064] The wire guide die cleaning function completes the processing, and the low-pressure control solenoid valve opens. The jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly to complete the wire guide die cleaning and prepare for the next processing. The water finally flows to the processing tank.

[0065] During machining, the first and second cuts, i.e. rough machining, are carried out first. The high-pressure solenoid valve is turned on and the jet pump operates at a frequency of 63Hz to remove a large amount of discharge generated during machining, thereby increasing machining speed and effectively preventing wire breakage. The water eventually flows into the machining tank.

[0066] During machining, the third and fourth machining processes, i.e., finishing, are carried out. The low-pressure solenoid valve is opened and the jet pump operates at a frequency of 30Hz to remove the discharge generated during finishing, improve the quality of the machined surface, and effectively prevent wire breakage. The water eventually flows to the machining tank.

[0067] During processing, when the electrode wire is discharged, the water-wire separation solenoid valve opens, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly. Under the action of the suction pump, the water and the electrode wire are mixed and separated through the water-wire separator, thereby removing the residual moisture in the electrode wire. The electrode wire flows to the waste wire barrel, and the water finally flows to the sewage tank.

[0068] Control method of liquid feeding pump system:

[0069] The liquid delivery pump system is responsible for liquid temperature regulation, air conditioning circulation, conductivity system liquid delivery, and together with the circulation pump, is responsible for liquid level regulation, rust removal device liquid supply, and workbench preheating treatment liquid delivery:

[0070] The liquid temperature regulates the air conditioning cycle, and the water eventually flows to the ultra-clear water tank;

[0071] Conductivity system liquid delivery: When the conductivity sensor senses that the conductivity value of the water tank is low, the conductivity control solenoid valve opens and delivers liquid to the ion resin barrel, and the water eventually flows to the clean water tank;

[0072] Liquid level adjustment: When the machine is turned on, the first and second emergency solenoid valves are opened at a frequency of 30Hz, and liquid is fed to the processing tank and stops at the float switch, which can ensure that the temperature change of the worktable is minimized during processing; during processing, the intermediate liquid level is replenished. In order to maintain the processing, the intermediate liquid level solenoid valve is opened to prevent processing interruption due to leakage from the processing tank; during processing, when the liquid level falls below the lower limit, the emergency solenoid valve is opened to feed liquid to the middle position of the liquid level switch; during processing, some water in the gap between the processing tank will leak into the sewage tank. When the signal of the liquid level switch at the middle position disappears, the intermediate liquid level solenoid valve is opened, and the liquid feeding pump feeds liquid. When it reaches the middle position, the signal is turned on and the solenoid valve is closed;

[0073] The rust removal device supplies liquid. When the concentration detection system detects that the rust removal powder concentration in the clean water tank is lower than the set value, the concentration meter controls the solenoid valve to open, and the water eventually flows to the clean water tank;

[0074] Further, the control method of the circulation pump system:

[0075] The circulating pump system is responsible for sewage filtration and, together with the liquid delivery pump, is responsible for liquid level regulation:

[0076] When sewage is filtered, the normally open filter barrel solenoid valve is closed, and the pressure is sensed by the pressure sensor at the filter, thereby controlling the frequency of the circulating pump inverter.

[0077] Liquid level adjustment: When the machine is turned on, the second rapid liquid delivery solenoid valve is opened and the normally open filter barrel solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid to the processing tank together until it stops at the float switch; during processing, when the processing liquid level is lower than the lower limit, the second rapid liquid delivery solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid together to the middle position of the liquid level switch.

[0078] The circulating pump of the present invention is controlled by a frequency converter and equipped with a pressure sensor. The pressure change of the pressure sensor is fed back to the control system, thereby controlling the operating frequency of the frequency converter, thereby achieving the purpose of saving electricity.

[0079] The liquid delivery pump is controlled by a frequency converter, and the frequency of the frequency converter is reduced to 60-70%, thereby reducing unnecessary energy consumption.

[0080] An independent concentration detection device has been developed in the rust removal system to monitor the concentration of the rust remover in the storage tank in real time, thereby reducing the use of rust removal powder.

[0081] By adding a liquid level control system and preserving machining fluid in the machining tank during the preparatory phase of the process, such as setting the workpiece position, temperature fluctuations on the machine can be suppressed. This improves the accuracy of the work surface due to temperature fluctuations on the liquid, thereby enhancing machining accuracy. By preserving machining fluid, the time required to deliver fluid at the start of machining can be shortened, improving preparation efficiency. Furthermore, the frequency of the liquid temperature control air conditioner activation can be reduced, thereby reducing power consumption.

[0082] During machining, the jet system, depending on the machining conditions (high-pressure jet or low-pressure jet), flows from the ultra-clean water tank into the processing tank. Approximately 30 liters / min of clean water is also flowing from the liquid delivery pump, resulting in an excess of water in the processing tank. In this case, the control system can use the jet pump's output frequency to control the liquid delivery pump's inverter frequency conversion value (approximately 70-85%).

[0083] The overall working process of the water circulation system:

[0084] Rapid delivery: During the processing preparation stage, when the control system receives the rapid delivery signal, the frequency converters of the liquid delivery pump and the circulation pump operate at a frequency of 50Hz.

[0085] For urgent delivery and unprocessed products, the circulation pump is controlled by a frequency converter and equipped with a pressure sensor. Pressure changes from the pressure sensor are fed back to the control system, which controls the frequency of the frequency converter, thus saving electricity. The liquid delivery pump is also controlled by a frequency converter, and the frequency converter is reduced to 60-70%, thus reducing unnecessary energy consumption.

[0086] An independent concentration detection device has been developed in the rust removal system to monitor the concentration of the rust remover in the storage tank in real time, thereby reducing the use of rust removal powder.

[0087] The intermediate liquid level control function within the machining tank reserves machining fluid in the machining tank during the process preparation phase, such as setting the workpiece position. This helps suppress temperature fluctuations on the main machine. This improves the accuracy of the work surface due to temperature fluctuations, thereby enhancing machining accuracy. By reserving machining fluid, the time required to deliver fluid at the start of machining can be shortened, improving setup efficiency.

[0088] During machining, the jet system, depending on the machining conditions (high-pressure jet or low-pressure jet), flows from the ultra-clean water tank into the processing tank. Approximately 30 liters / min of clean water is also flowing from the liquid delivery pump, resulting in an excess of water in the processing tank. In this case, the control system can use the jet pump's output frequency to control the liquid delivery pump's inverter frequency conversion value (approximately 70-85%).

[0089] The above description and embodiments are intended to explain the scope of protection of the present invention, but do not constitute a limitation thereto. Modifications, equivalent substitutions, or other improvements to the embodiments of the present invention or portions thereof that can be obtained by a person of ordinary skill in the art through logical analysis, reasoning, or limited experimentation based on the teachings of the present invention or the above embodiments, combined with common knowledge, ordinary technical knowledge in the field, and / or prior art, should all be included within the scope of protection of the present invention.

Claims

1. A water circulation system for a wire-cut electric discharge machine, characterized in that: The wire-cut EDM machine includes a workbench, a guide assembly, a processing water tank, a water-wire separation assembly, an ultra-clear water tank, a clean water tank, and a sewage tank that cooperate with each other; the electrode wire passes through the workbench, the guide assembly, and the water-wire separation assembly in sequence and enters the waste wire barrel; the water circulation system is connected to the processing water tank, the ultra-clear water tank, the clean water tank, and the sewage tank through various components; and includes a jet pump system, a liquid delivery pump system, and a circulation pump system that cooperate with each other; wherein: The jet pump system includes: a jet pump equipped with a jet pump frequency converter, which is installed in the ultra-clear water tank. The jet pump is connected to two branches; one branch is connected to the parallel automatic threading water spray solenoid valve, high-pressure control solenoid valve, and low-pressure control solenoid valve, and the three solenoid valves are connected to the guide assembly; the other branch is connected to the water silk separator solenoid valve, and then connected to the water silk separator suction pump, which delivers the sewage separated by the water silk separator into the sewage tank through the suction pump; The liquid feeding pump system includes: a liquid feeding pump provided with a liquid feeding pump frequency converter in the clean water tank, the liquid feeding pump is connected to four branches, the first branch is connected to the liquid temperature control system in the ultra-clear water tank; the second branch is connected to the liquid level control system; the third branch is connected to the conductivity control system in the clean water tank; and the fourth branch is connected to the concentration detection system in the clean water tank; The circulating pump system includes: a circulating pump provided with a circulating pump frequency converter in the sewage tank, the circulating pump is connected to two branches, one branch is connected to the filtration system in the ultra-clear water tank; the other branch is connected to the liquid level control system; The liquid level adjustment system includes three branches. The first branch is responsible for adding liquid when the machine is started and replenishing liquid when the liquid level is lower than the lower limit during processing. It includes an emergency solenoid valve 1 connected to the liquid feeding pump. The emergency solenoid valve 1 is connected to the processing tank and is responsible for the float switch position of adding liquid to the processing tank when the machine is started; the second branch is responsible for emergency delivery before processing, including an emergency solenoid valve 1 connected to the liquid feeding pump and an emergency solenoid valve 2 connected to the circulation pump. The emergency solenoid valve 1 and the emergency solenoid valve 2 are respectively connected to the processing tank to ensure that the liquid level before processing is between the upper and lower limit switches above the processing tank; the third branch is responsible for intermediate liquid level adjustment, including an intermediate liquid level solenoid valve connected to the liquid feeding pump. The intermediate liquid level solenoid valve is connected to the processing tank to ensure that the liquid level during processing is between the upper and lower limit switches above the processing tank; The concentration detection system includes: a concentration meter control solenoid valve connected to the liquid delivery pump, the concentration meter control solenoid valve is connected to the concentration detection system and the filter respectively, the filter is connected to the rust removal powder placement barrel, and the rust removal powder placement barrel is connected to the clean water tank through a constant flow valve.

2. The water circulation system for a wire-cut electric discharge machine according to claim 1, characterized in that: The liquid temperature regulating system comprises a liquid temperature sensor communicated with the liquid feeding pump, and the liquid temperature sensor is communicated with a liquid temperature regulating air conditioner arranged in the ultra-clear water tank.

3. The water circulation system for a wire-cut electric discharge machine according to claim 1, characterized in that: The conductivity control system includes a conductivity control solenoid valve connected to the liquid feeding pump, the conductivity control solenoid valve is connected to the ion resin barrel in the clean water tank, and the conductivity control solenoid valve is also connected to a conductivity sensor.

4. The water circulation system for a wire-cut electric discharge machine according to claim 1, characterized in that: The filtration system includes a filter barrel solenoid valve connected to a circulation pump, the filter barrel solenoid valve is connected to a filter barrel arranged in an ultra-clear water tank, and the filter barrel solenoid valve is further connected to a pressure sensor.

5. The control method for the water circulation system of the electric spark wire cutting machine according to claim 1, 2, 3 or 4, characterized in that: Control method of jet pump system: The jet pump system is responsible for the supply of jet fluid for roughing / finishing, guiding the electrode wire during automatic threading, removing moisture during electrode wire discharge, and cleaning the wire guide die: During automatic wire threading, the water spray solenoid valve for automatic wire threading is opened, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly, so that the electrode wire is guided from the upper guide to the lower guide, completing the wire threading, and the water finally flows to the processing tank; The wire guide die cleaning function, when the processing is completed, the low-pressure control solenoid valve is opened, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly to complete the wire guide die cleaning and prepare for the next processing. The water finally flows to the processing tank; During machining, the first and second cuts, i.e. rough machining, are carried out first. The high-pressure solenoid valve is turned on and the jet pump operates at a frequency of 63Hz to remove a large amount of discharge generated during machining, thereby increasing machining speed and effectively preventing wire breakage. The water eventually flows into the machining tank. During machining, the third and fourth machining processes, i.e., finishing, are carried out. The low-pressure solenoid valve is opened and the jet pump operates at a frequency of 30Hz to remove the discharge generated during finishing, improve the quality of the machined surface, and effectively prevent wire breakage. The water eventually flows to the machining tank. During processing, when the electrode wire is discharged, the water-wire separation solenoid valve opens, and the jet pump works under the control of the jet pump solenoid valve to spray water to the guide assembly. Under the action of the suction pump, the water and the electrode wire are mixed and separated through the water-wire separator, thereby removing the residual moisture in the electrode wire. The electrode wire flows to the waste wire barrel, and the water finally flows to the sewage tank.

6. The control method for the water circulation system of the wire-cut electric discharge machine according to claim 5, characterized in that: Control method of liquid feeding pump system: The liquid delivery pump system is responsible for liquid temperature regulation, air conditioning circulation, conductivity system liquid delivery, and together with the circulation pump, is responsible for liquid level regulation, rust removal device liquid supply, and workbench preheating treatment liquid delivery: The liquid temperature regulates the air conditioning cycle, and the water eventually flows to the ultra-clear water tank; Conductivity system liquid delivery: When the conductivity sensor senses that the conductivity value of the water tank is low, the conductivity control solenoid valve opens and delivers liquid to the ion resin barrel, and the water eventually flows to the clean water tank; Liquid level adjustment: When the machine is turned on, the emergency solenoid valve opens at a frequency of 30Hz, and liquid is fed to the processing tank until it stops at the float switch, which ensures that the temperature change of the work surface is minimized during processing. During processing, the intermediate liquid level is replenished. In order to maintain the processing, the intermediate liquid level solenoid valve opens to prevent processing interruption due to leakage from the processing tank. During processing, when the liquid level falls below the lower limit, the emergency solenoid valve opens to feed liquid to the middle position of the liquid level switch. During processing, some water in the gap between the processing tanks will leak into the sewage tank. When the signal at the middle position of the liquid level switch disappears, the intermediate liquid level solenoid valve opens, and the liquid feed pump feeds liquid. When the liquid level reaches the middle position, the signal opens and the solenoid valve closes. The rust removal device supplies liquid. When the concentration detection system detects that the rust removal powder concentration in the clean water tank is lower than the set value, the concentration meter controls the solenoid valve to open, and the water finally flows to the clean water tank.

7. The control method for the water circulation system of the wire-cut electric discharge machine according to claim 5, characterized in that: Control method of circulation pump system: The circulating pump system is responsible for sewage filtration and, together with the liquid delivery pump, is responsible for liquid level regulation: When sewage is filtered, the normally open filter barrel solenoid valve is closed, and the pressure is sensed by the pressure sensor at the filter to control the frequency of the circulating pump inverter; Liquid level adjustment: When the machine is turned on, the second rapid liquid delivery solenoid valve is opened and the normally open filter barrel solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid to the processing tank together until it stops at the float switch; during processing, when the processing liquid level is lower than the lower limit, the second rapid liquid delivery solenoid valve is opened, and the circulation pump and the liquid delivery pump deliver liquid together to the middle position of the liquid level switch.

Images