A new type of discharge oil hydraulic circuit for electrical discharge machining

Abstract

The present invention provides a new type of discharge oil hydraulic circuit of an electric discharge machine, which discharges the black residue in the oil tank without stopping the machine, ensures the safe liquid level of the industrial oil in the oil tank at all times, improves the utilization rate of the industrial oil, ensures continuous production, and reduces production costs. An oil overflow hole is provided at the highest position of the liquid level of the oil tank, and the oil overflow hole is connected to the oil tank through an oil overflow pipeline. An upper first liquid level sensing device and a bottom second liquid level sensing device are provided in the inner cavity of the oil tank. The bottom second liquid level sensing device is used to monitor the height position of the black residue and the height of the bottom liquid level. The upper first liquid level sensing device is used to detect the liquid level of the industrial oil. An oil discharge hole is provided at the bottom of the oil tank, and the bottom of the oil discharge hole is connected to a first oil outlet pipe. The output end of the first oil outlet pipe is connected to the inlet of a third valve, and the outlet of the third valve is connected to the outlet of a fourth valve and the inlet of a second oil pump through pipelines.

Description

Technical Field

[0001] The invention relates to the technical field of electrical discharge machine structure, in particular to a new type of electrical discharge oil hydraulic circuit of an electrical discharge machine. Background Art

[0002] The EDM uses processing oil as a coolant and to remove black slag during processing; in order to effectively cool and remove slag during processing, the processing position must be completely immersed in the discharge oil, so the appropriate liquid level must be controlled, and a simple oil overflow port is usually used; however, the setting of the oil overflow port can only control the liquid level. Since the discharge slag is relatively heavy, it will settle to the bottom of the oil tank and cannot be discharged through the oil overflow port, resulting in the longer the processing time, the more black slag in the processing oil tank, and the dirtier the processing effect. If the bottom is used to control the liquid level, the slag can be effectively discharged, but the liquid level is difficult to control. If the control is improper, the liquid level will be too low, resulting in a failure to cool, thereby causing a fire hazard. For this reason, the prior art is that after the EDM has been running for a period of time, it is necessary to stop the machine and discharge all the oil and black slag in the oil tank through the oil drain port. The shutdown process affects the production progress, and the oil and black slag are all discharged, resulting in low utilization of the processing oil and increased production costs. Summary of the invention

[0003] In response to the above problems, the present invention provides a new type of discharge oil hydraulic circuit for an electrical discharge machine, which can discharge the black residue in the oil tank without stopping the machine, always ensuring the safe liquid level of the industrial oil in the oil tank, improving the utilization rate of the industrial oil, ensuring continuous production, and reducing production costs.

[0004] A new type of discharge oil hydraulic circuit for an electrical discharge machine, and its technical solution is as follows: it includes an oil trough and an oil tank, an oil overflow hole is provided at the highest position of the liquid level in the oil trough, and the oil overflow hole is connected to the oil tank through an oil overflow pipeline, and is characterized in that: an upper first liquid level sensing device and a bottom second liquid level sensing device are provided in the inner cavity of the oil trough, the bottom second liquid level sensing device is used to monitor the height position of black slag and the height of the bottom liquid level, the upper first liquid level sensing device is used to detect the liquid level of industrial oil, an oil drain hole is provided at the bottom of the oil trough, the bottom of the oil drain hole is connected to a first oil outlet pipe, the output end of the first oil outlet pipe is connected to the inlet of a third valve, and the outlet of the third valve is connected to the first and second oil outlets through pipelines respectively. The outlet of the fourth valve and the inlet of the second oil pump, the outlet of the fourth valve is connected to the inlet of the second oil pump at the same time, the oil tank is provided with a second oil inlet pipe connected to the inlet of the fourth valve, the outlet of the second oil pump is connected to the inlet of at least one second filter element, the outlet of the second filter element is respectively connected to the inlet of the first valve and the inlet of the second valve, the outlet of the first valve supplies oil to the oil tank through the third oil inlet pipe, the outlet of the second valve discharges oil to the oil tank through the first oil discharge pipe, the oil tank is also connected to the inlet of the first oil pump through a pipeline, the outlet of the first oil pump supplies oil to the oil tank through the first oil inlet pipe, the first oil inlet pipe is arranged with an oil cooler, and the first oil pump is used to provide cooled processing oil and maintain the oil level in the oil tank.

[0005] It is further characterized by:

[0006] The first valve, the second valve, the third valve and the fourth valve are all solenoid valves, which ensure accurate control of each valve;

[0007] The outlet of the second oil pump is connected in parallel to the inlets of N second filter elements, and the outlets of the N second filter elements are connected in parallel to enter the filter outlet pipeline, wherein N is a natural number greater than or equal to 2, and the filter outlet pipeline is connected to the inlet of the first valve and the inlet of the second valve respectively;

[0008] The inlet and outlet positions of each second filter element are respectively provided with corresponding connection valves. When a second filter element needs to be replaced, the connection valve at the corresponding position is closed, so that the entire circuit can still be ensured to be in working condition without stopping for replacement;

[0009] A first filter element is disposed behind the outlet of the first oil pump to ensure the purity of the oil entering the oil tank;

[0010] A temperature sensor is also arranged in the oil tank. When the temperature sensor feedback temperature is higher than the setting or the temperature increase rate is greater than the setting standard, the oil cooler is turned on by the first oil pump to add cold oil to the oil tank until the temperature sensor detects that the temperature in the oil tank is within the monitoring range;

[0011] Preferably, M parallel first filter elements are arranged behind the outlet of the first oil pump, and each of the M first filter elements corresponds to an independent inlet and outlet connection valve, wherein M is a natural number greater than or equal to 2, so as to ensure that when one of the first filter elements is replaced, the entire circuit is still in working condition and does not need to be stopped for replacement;

[0012] The first filter element and the second filter element are filter elements of the same structure to ensure universality;

[0013] The third valve is connected to the first end of the first three-way connection, the second end of the first three-way connection is connected to the outlet of the fourth valve, and the third end of the first three-way connection is connected to the inlet of the second oil pump, which makes assembly quick and convenient;

[0014] The bottom of the oil tank is provided with a downwardly convex attached cavity, a plurality of second liquid level sensing devices are arranged in the attached cavity, and the oil drain hole is arranged at the bottom of the attached cavity;

[0015] The black residue in the oil tank will gradually settle in the auxiliary cavity due to gravity and the flow of liquid. When the amount of black residue is small, it is ensured that the black residue will not affect the normal operation of the main cavity of the oil tank and the processing effect. When the amount of black residue in the auxiliary cavity is detected by the second liquid level sensing device to meet the residue cleaning standard, the first valve and the third valve are opened, and the second valve and the fourth valve are closed, so that the second oil pump draws the oil from the bottom of the oil tank for forced oil extraction and filtration circulation, so that the discharged black residue is forced to be discharged and filtered, so as to avoid the black residue being directly discharged into the oil tank, causing the black residue to settle at the bottom of the oil tank, and the filtered oil returns to the oil tank to avoid insufficient oil in the oil tank and achieve the filtering function at the same time;

[0016] When the oil is inlet, the corresponding valves are controlled, the first valve and the fourth valve are opened, and the second valve and the third valve are closed, so that the first oil pump and the second oil pump supply oil to the oil tank at the same time, so that the oil in the oil tank can quickly reach the liquid level height, and when the oil is full, it flows out from the overflow port and effectively controls the liquid level height;

[0017] When the processing is stopped or the oil tank needs to be cleaned, the second valve and the third valve are controlled to be opened, the first valve and the fourth valve are closed, the second oil pump is started, and the oil tank is directly pumped out for filtration and discharged into the oil tank. After the oil in the oil tank is drained, the second liquid level sensing device at the bottom detects it and automatically shuts down the second oil pump.

[0018] After adopting the structure of the present invention, the second liquid level sensing device at the bottom monitors the height change of the black residue at the bottom of the oil tank. When the amount of black residue is detected by the second liquid level sensing device to meet the residue cleaning standard, the first valve and the third valve are opened, and the second valve and the fourth valve are closed, so that the second oil pump draws the oil from the bottom of the oil tank for forced oil extraction and filtration circulation, and the discharged black residue is forced to be discharged and filtered, so as to avoid the black residue being directly discharged into the oil tank, causing the black residue to settle at the bottom of the oil tank, and the filtered oil returns to the oil tank to avoid insufficient oil in the oil tank. At the same time, the filtering function is achieved, which discharges the black residue in the oil tank without stopping the machine, always ensures the safe liquid level of the industrial oil in the oil tank, improves the utilization rate of the industrial oil, ensures continuous production, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The oil circuit layout diagram of a specific embodiment of the present invention;

[0020] The names corresponding to the serial numbers in the figure are as follows:

[0021] Oil tank 1, oil tank 2, oil overflow hole 3, first upper liquid level sensing device 4, second bottom liquid level sensing device 5, oil drain hole 6, first oil outlet pipe 7, third valve 8, fourth valve 9, second oil pump 10, second oil inlet pipe 11, second filter element 12, first valve 13, second valve 14, third oil inlet pipe 15, first oil drain pipe 16, first oil pump 17, first oil inlet pipe 18, oil cooler 19, filter outlet pipeline 20, first filter element 21, second three-way valve 22, first three-way valve 23, attached chamber 24, oil overflow pipeline 25. DETAILED DESCRIPTION

[0022] A new type of discharge oil hydraulic circuit for electric discharge machining machine, see Figure 1, which comprises an oil tank 1 and an oil tank 2. An oil overflow hole 3 is arranged at the highest position of the liquid level of the oil tank 1. The oil overflow hole 3 is connected to the oil tank 2 through an oil overflow pipeline 25. An upper first liquid level sensing device 4 and a bottom second liquid level sensing device 5 are arranged in the inner cavity of the oil tank 1. The bottom second liquid level sensing device 5 is used to monitor the height position of the black slag and the height of the bottom liquid level. The upper first liquid level sensing device 4 is used to detect the liquid level of the industrial oil. An oil discharge hole 6 is arranged at the bottom of the oil tank 1. The bottom of the oil discharge hole 6 is connected to a first oil outlet pipe 7. The output end of the first oil outlet pipe 7 is connected to the inlet of a third valve 8. The outlet of the third valve 8 is connected to the outlet of a fourth valve 9 and the inlet of a second oil pump 10 through pipelines respectively. The outlet of the fourth valve 9 The oil tank 1 is provided with a second oil inlet pipe 11 connected to the inlet of the fourth valve 9, the outlet of the second oil pump 10 is connected to the inlet of at least one second filter element 12, the outlet of the second filter element 12 is respectively connected to the inlet of the first valve 13 and the inlet of the second valve 14, the outlet of the first valve 13 supplies oil to the oil tank 1 through the third oil inlet pipe 15, the outlet of the second valve 14 discharges oil to the oil tank 2 through the first oil discharge pipe 16, the oil tank 2 is also connected to the inlet of the first oil pump 17 through a pipeline, the outlet of the first oil pump 17 supplies oil to the oil tank through the first oil inlet pipe 18, the first oil inlet pipe 18 is arranged with an oil cooler 19, the first oil pump 17 is used to provide cooled processing oil and maintain the oil level in the oil tank.

[0023] The first valve 13, the second valve 14, the third valve 8, and the fourth valve 9 are all solenoid valves, which ensure accurate control of each valve;

[0024] Preferably, the outlet of the second oil pump 10 is connected in parallel to the inlets of N second filter elements 12, and the outlets of the N second filter elements 12 are connected in parallel and enter the filter outlet pipeline 20, wherein N is a natural number greater than or equal to 2, and the filter outlet pipeline 20 is respectively connected to the inlet of the first valve 13 and the inlet of the second valve 14;

[0025] The inlet and outlet positions of each second filter element 12 are respectively provided with corresponding connection valves. When a second filter element 12 needs to be replaced, the connection valve at the corresponding position is closed, so that the entire circuit can still be ensured to be in working condition without stopping for replacement;

[0026] A first filter element 21 is provided behind the outlet of the first oil pump 17 to ensure the purity of the oil entering the oil tank 1;

[0027] A temperature sensor (not shown in the figure, belonging to conventional temperature control technology) is also arranged in the oil tank 1. When the temperature sensor feedback temperature is higher than the set temperature or the temperature increase rate is greater than the set standard, the oil cooler 19 is turned on by the first oil pump 14 to add cold oil to the oil tank 1 until the temperature sensor detects that the temperature in the oil tank is within the monitoring range;

[0028] Preferably, M parallel first filter elements 21 are arranged behind the outlet of the first oil pump 17, and each of the M first filter elements 21 corresponds to an independent inlet and outlet connection valve, wherein M is a natural number greater than or equal to 2, so as to ensure that when one of the first filter elements 21 is replaced, the entire circuit is still in working condition and does not need to be stopped for replacement;

[0029] The first filter element 21 and the second filter element 12 are filter elements with the same structure to ensure universality.

[0030] Specific embodiment: the outlet of the second oil pump 10 is connected in parallel to the inlets of the two second filter elements 12, and the outlets of the two second filter elements 12 are connected in parallel to enter the filter outlet pipeline 20, and the filter outlet pipeline 20 is connected to the inlet of the first valve 13 and the inlet of the second valve 14 respectively through the second three-way 22;

[0031] The inlet and outlet positions of each second filter element 12 are respectively provided with corresponding connecting valves (not shown in the figure, belonging to the existing mature technology). When a second filter element 12 needs to be replaced, the connecting valve at the corresponding position is closed, so that the entire circuit can still be ensured to be in working condition without stopping for replacement;

[0032] A first filter element 21 is disposed behind the outlet of the first oil pump 17 to ensure the purity of the oil entering the oil tank 1;

[0033] The third valve 8 is connected to the first end of the first three-way valve 23, the second end of the first three-way valve 23 is connected to the outlet of the fourth valve 9, and the third end of the first three-way valve 23 is connected to the inlet of the second oil pump 10, which makes the assembly quick and convenient;

[0034] A downwardly convex attached cavity 24 is provided at the bottom of the oil tank 1 , a plurality of second liquid level sensing devices 5 are provided in the attached cavity 24 , and an oil drain hole 6 is provided at the bottom of the attached cavity 24 .

[0035] Figure 1 The arrow on the middle pipe indicates the flow direction of industrial oil.

[0036] Here’s how it works:

[0037] The first oil pump is used to provide cooling processing oil and maintain the oil level in the oil tank. If the oil level is insufficient due to a fault, an alarm will be issued and the entire machine will stop processing;

[0038] The black residue in the oil tank will gradually settle in the auxiliary cavity due to gravity and the flow of liquid. When the amount of black residue is small, it is ensured that the black residue will not affect the normal operation of the main cavity of the oil tank and the processing effect. When the amount of black residue in the auxiliary cavity is detected by the second liquid level sensing device to meet the residue cleaning standard, the first valve and the third valve are opened, and the second valve and the fourth valve are closed, so that the second oil pump draws the oil from the bottom of the oil tank for forced oil extraction and filtration circulation, so that the discharged black residue is forced to be discharged and filtered, so as to avoid the black residue being directly discharged into the oil tank, causing the black residue to settle at the bottom of the oil tank. The filtered oil returns to the oil tank to avoid insufficient oil in the oil tank and achieve the filtering function at the same time.

[0039] When the oil is inlet, the corresponding valves are controlled, the first valve and the fourth valve are opened, and the second valve and the third valve are closed, so that the first oil pump and the second oil pump supply oil to the oil tank at the same time, so that the oil in the oil tank can quickly reach the liquid level height, and when the oil is full, it flows out from the overflow port and effectively controls the liquid level height;

[0040] When the processing is stopped or the oil tank needs to be cleaned, the second valve and the third valve are controlled to be opened, the first valve and the fourth valve are closed, and the second oil pump is started to directly extract the oil from the oil tank for filtration and discharge to the oil tank. After the oil in the oil tank is completely drained, the second liquid level sensing device at the bottom detects it and automatically shuts down the second oil pump;

[0041] It discharges the black residue in the oil tank without stopping the machine, ensures the safe liquid level of the industrial oil in the oil tank at all times, improves the utilization rate of the industrial oil, ensures continuous production, and reduces production costs.

[0042] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A novel discharge oil hydraulic circuit of an electrical discharge machine, comprising an oil trough and an oil tank, wherein an oil overflow hole is provided at the highest position of the liquid level of the oil trough, and the oil overflow hole is connected to the oil tank through an oil overflow pipeline, and is characterized in that: The inner cavity of the oil tank is provided with an upper first liquid level sensing device and a bottom second liquid level sensing device. The bottom second liquid level sensing device is used to monitor the height position of the black slag and the height of the bottom liquid level. The upper first liquid level sensing device is used to detect the liquid level of the industrial oil. The bottom of the oil tank is provided with an oil drain hole. The bottom of the oil drain hole is connected to a first oil outlet pipe. The output end of the first oil outlet pipe is connected to the inlet of a third valve. The outlet of the third valve is connected to the outlet of a fourth valve and the inlet of a second oil pump through pipelines respectively. The outlet of the fourth valve is simultaneously connected to the inlet of the second oil pump. The oil tank A second oil inlet pipe is provided to connect the inlet of the fourth valve, the outlet of the second oil pump is connected to the inlet of at least one second filter element, the outlet of the second filter element is respectively connected to the inlet of the first valve and the inlet of the second valve, the outlet of the first valve supplies oil to the oil tank through the third oil inlet pipe, the outlet of the second valve discharges oil to the oil tank through the first oil discharge pipe, the oil tank is also connected to the inlet of the first oil pump through a pipeline, the outlet of the first oil pump supplies oil to the oil tank through the first oil inlet pipe, an oil cooler is arranged on the first oil inlet pipe, and the first oil pump is used to provide cooled processing oil and maintain the oil level in the oil tank; The bottom of the oil tank is provided with a downwardly convex attached cavity, a plurality of second liquid level sensing devices are arranged in the attached cavity, and the oil drain hole is arranged at the bottom of the attached cavity; When the oil is inlet, the corresponding valves are controlled, the first valve and the fourth valve are opened, and the second valve and the third valve are closed, so that the first oil pump and the second oil pump supply oil to the oil tank at the same time, so that the oil in the oil tank can quickly reach the liquid level height, and when the oil is full, it flows out from the overflow port and effectively controls the liquid level height; When the processing is stopped or the oil tank needs to be cleaned, the second valve and the third valve are controlled to be opened, the first valve and the fourth valve are closed, the second oil pump is started, and the oil tank is directly pumped out for filtration and discharged into the oil tank. After the oil in the oil tank is drained, the second liquid level sensing device at the bottom detects it and automatically shuts down the second oil pump.

2. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 1, characterized in that: The first valve, the second valve, the third valve and the fourth valve are all solenoid valves.

3. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 1, characterized in that: The outlet of the second oil pump is connected in parallel to the inlets of N second filter elements, and the outlets of the N second filter elements are connected in parallel to enter the filter outlet pipeline, where N is a natural number greater than or equal to 2, and the filter outlet pipeline is respectively connected to the inlet of the first valve and the inlet of the second valve.

4. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 3, characterized in that: The inlet and outlet positions of each second filter element are respectively provided with corresponding connecting valves. When a second filter element needs to be replaced, the connecting valve at the corresponding position is closed.

5. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 1, characterized in that: A first filter element is arranged behind the outlet of the first oil pump.

6. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 1, characterized in that: A temperature sensor is also arranged in the oil tank. When the temperature sensor feedback temperature is higher than the set temperature or the temperature growth rate is greater than the set standard, the oil cooler is turned on by the first oil pump to add cold oil to the oil tank until the temperature sensor detects that the temperature in the oil tank is within the monitoring range.

7. A novel discharge oil hydraulic circuit for an electrical discharge machine as claimed in claim 1, characterized in that: M parallel first filter elements are arranged behind the outlet of the first oil pump, and each of the M first filter elements corresponds to an independent inlet and outlet connecting valve, wherein M is a natural number greater than or equal to 2; the first filter element and the second filter element are filter elements with the same structure.

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