Low-pressure control electromagnetic unloading valve for high-flow long-life emulsion pump

Abstract

The invention discloses a low-pressure control electromagnetic unloading valve for a large-flow long-service-life emulsion pump. The low-pressure control electromagnetic unloading valve comprises a main valve body and a main valve element, and the main valve element is arranged in the main valve body in a sliding mode and controls the internal conduction state of the main valve body; the right end of the main valve body is fixedly connected with a pilot connecting plate; a longitudinal hole channel longitudinally penetrating through the main valve body and a transverse hole channel transversely penetrating through the main valve body are formed in the main valve body, the longitudinal hole channel and the transverse channel are arranged in a crossed mode and communicate with each other, and the left end of the transverse hole channel is connected with an unloading connector. The main valve element is slidably connected into the transverse hole channel and can slide in the axis direction of the transverse hole channel, a control cavity is formed between the right end of the main valve element and the pilot connecting plate and between the inner wall of the transverse hole channel and the pilot connecting plate, and a channel combination structure is arranged in the pilot connecting plate. The channel combination structure is communicated with the control cavity and guides low-pressure control liquid into or out of the control cavity so as to control the moving position of the valve element of the main valve.

Description

Technical Field

[0001] This invention relates to the field of unloading valves, and more particularly to a low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump. Background Technology

[0002] The electromagnetic unloading valve is an automatic regulating device used in emulsion pump stations to unload and reload high-pressure liquid when it reaches the rated pressure. To meet the liquid supply requirements of the coal face supports, the emulsion pump needs to frequently perform loading and unloading processes. Currently, the position of the valve core within the valve body is mainly controlled pneumatically to achieve the discharge and high-pressure unloading functions of the electromagnetic unloading valve. However, after prolonged use, the valve core and valve body of the electromagnetic unloading valve are prone to cavitation damage, leading to valve failure or unstable operation. Ultimately, this results in unstable pressure in the pump station's liquid supply system, causing vibration or supply failure. Therefore, improvements are necessary. Summary of the Invention

[0003] The purpose of this invention is to address the above-mentioned problems by providing a low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump that features a simple structure, avoids cavitation damage, and effectively extends the service life of the unloading valve.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump includes a main valve body and a main valve core. The main valve core is slidably disposed within the main valve body and controls the internal conduction state of the main valve body. A pilot connecting plate is fixedly connected to the right end of the main valve body. The main valve body has a longitudinal channel penetrating the main valve body and a transverse channel penetrating the main valve body. The longitudinal channel and the transverse channel are intersected and interconnected. The left end of the transverse channel is connected to an unloading connector. The main valve core is slidably connected within the transverse channel and can slide along the axial direction of the transverse channel. A control cavity is formed between the right end of the main valve core, the inner wall of the transverse channel, and the pilot connecting plate. A channel assembly structure is disposed within the pilot connecting plate. The channel assembly structure is connected to the control cavity and introduces or exports low-pressure control fluid into or out of the control cavity to control the movement position of the main valve core.

[0005] Furthermore, the channel assembly structure includes a low-pressure inlet, a control fluid inlet, a first control fluid outlet, a second control fluid outlet, and a third control fluid outlet. The control fluid inlet and the first control fluid outlet are connected to the low-pressure inlet to form a three-way structure. The low-pressure inlet is located at the bottom of the pilot connecting plate and is connected to the control fluid pump body. The control fluid inlet is connected to the control chamber. The first and second control fluid outlets both penetrate the right end wall of the pilot connecting plate. A solenoid valve is fixedly connected to the right end wall of the pilot connecting plate. The two ends of the solenoid valve are respectively connected to the first and second control fluid outlets and control the connection state between the first and second control fluid outlets. The bottom end of the third control fluid outlet is connected to the second control fluid outlet, and the top end of the third control fluid outlet penetrates the top end wall of the pilot connecting plate and is connected to the control fluid return pipeline.

[0006] Furthermore, the main valve core is divided into a valve head section, a valve stem section, and a valve cap section from left to right. The outer diameter of the valve stem section is smaller than that of the valve head section and the valve cap section. A first-stage variable diameter groove, a second-stage variable diameter groove, a third-stage variable diameter groove, and a fourth-stage variable diameter groove are arranged in the transverse channel, progressively increasing in size from left to right. A first sliding sleeve is embedded in the first-stage variable diameter groove, and the first sliding sleeve is fitted onto the outside of the valve head section. A pressure cap is fixedly connected to the second-stage variable diameter groove, and the pressure cap limits the position of the first sliding sleeve. The third-stage variable diameter groove… An inner sleeve is provided with a return spring. The return spring and the pressure cap are both sleeved on the outside of the valve stem section. The two ends of the return spring abut against the inner wall of the left end of the three-stage reducing groove and the end wall of the left end of the valve cap section, respectively. A second sliding sleeve is embedded in the four-stage reducing groove and is sleeved on the outside of the valve cap section. The left end of the pilot connecting plate is embedded in the four-stage reducing groove and abuts against the right end of the second sliding sleeve to limit the position of the second sliding sleeve. The right end wall of the valve cap section, the inner wall of the second sliding sleeve, and the left end wall of the pilot connecting plate together form a control cavity.

[0007] Furthermore, the valve cap section is provided with a bolt clearance hole that extends laterally through the valve cap section to facilitate bolt fixing of the gland; a sealing plug is threaded into the bolt clearance hole.

[0008] Furthermore, the left end of the main valve body is provided with an unloading connector and is connected to the unloading return pipeline. The right end of the unloading connector extends into the inner side of the left end of the transverse channel and is threadedly connected to the inner wall of the transverse channel. The inner diameter of the right end of the internal channel of the unloading connector is adapted to the outer diameter of the left end of the valve head section, so that the left end of the valve head section can move to the left under the action of the control fluid in the control cavity and block and seal the internal channel of the unloading connector.

[0009] Furthermore, sealing rings for improving sealing performance are provided between the outer peripheral sidewall of the valve head section and the inner sidewall of the first sliding sleeve, between the outer peripheral sidewall of the valve cap section and the inner sidewall of the second sliding sleeve, between the sealing plug and the inner wall of the bolt clearance hole, between the left end wall of the pilot connecting plate and the right end wall of the main valve body, and between the unloading joint and the main valve body.

[0010] Furthermore, a vent hole is provided on the inner wall of the three-stage variable diameter groove to achieve pressure balance in the internal cavity when the main valve core slides. The vent hole penetrates the outer end wall of the main valve body.

[0011] Furthermore, the top of the longitudinal channel is connected to the emulsion tank via an emulsion pump, and a drain check valve is provided at the bottom of the longitudinal channel, which is fixedly connected to the bottom of the main valve body.

[0012] Furthermore, the drain check valve includes a valve cover, a drain valve body, a drain valve core, and a drain spring. A piston cavity is provided within the drain valve body. The top of the drain valve body is fixedly connected to the bottom of the main valve body via the valve cover. A fluid passage hole is provided on the valve cover. The top of the piston cavity communicates with the bottom of a longitudinal channel via the fluid passage hole. A connecting hole is provided at the bottom of the piston cavity and communicates with the oil supply hole of the hydraulic support. The drain valve core is disposed within the piston cavity and can slide longitudinally along the axial direction of the piston cavity. The core is hollow inside, with the bottom end of the hollow structure penetrating the bottom end wall of the drain valve core. The top end of the drain valve core is a tapered structure with a reduced diameter, and the side wall of the tapered structure has a side through hole that communicates with the hollow structure inside the drain valve core. A drain gap is formed between the outer wall of the tapered structure and the inner wall of the piston cavity. The drain spring is located between the inner wall of the bottom end of the piston cavity and the drain valve core. Under the elastic action of the drain spring, the top end of the drain valve core abuts against the valve cover and blocks and seals the through hole.

[0013] Compared with the prior art, the advantages and positive effects of this invention are: During normal fluid supply operation, the electromagnetic unloading valve of this invention injects control fluid into the control chamber through the channel assembly structure within the pilot connecting plate. This control fluid forces the main valve core to move to the left within the transverse channel, blocking the internal channel of the unloading connector. The emulsion pump then delivers the emulsion through the top of the longitudinal channel into the longitudinal channel, and after passing through the drain check valve, it is supplied to the hydraulic support. When the supply pressure is too high, the control fluid in the control chamber flows back through the channel assembly structure within the pilot connecting plate. The right end of the main valve core, under the elastic action of the return spring, abuts against the left end wall of the pilot connecting plate. The left end of the main valve core does not block the internal channel of the unloading connector. The high-pressure emulsion flows back into the emulsion tank after passing through the unloading connector. The low-pressure control fluid effectively realizes the discharge and high-pressure unloading functions of the electromagnetic unloading valve by controlling the outflow and inflow of the control chamber. It does not require pneumatic control of the position of the main valve core, avoiding cavitation damage caused by long-term pneumatic control, extending the service life of the electromagnetic unloading valve, ensuring the stable operation of the electromagnetic unloading valve, keeping the pressure of the pump station's liquid supply system stable, and effectively improving the stable liquid supply and support effect of the hydraulic support. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 A cross-sectional view of the connection structure between the main valve body and the drain check valve; Figure 3 Cross-sectional view of the connection structure between the main valve body and the pilot connecting plate; Figure 4 Cross-sectional view of the main valve body; Figure 5 A cross-sectional view of the main valve core; Figure 6 This is a cross-sectional view of the drain check valve. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without creative effort should be included within the protection scope of the present invention.

[0017] like Figures 1 to 6 As shown, this embodiment discloses a low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump, including a main valve body 1 and a main valve core 6. The main valve core 6 is slidably disposed within the main valve body 1 and controls the internal conduction state of the main valve body 1. A pilot connecting plate 2 is fixedly connected to the right end of the main valve body 1. The main valve body 1 is provided with a longitudinal channel 101 penetrating the main valve body 1 longitudinally and a transverse channel 102 penetrating the main valve body 1 transversely. The longitudinal channel 101 and the transverse channel 102 are intersected and connected. The left end of the transverse channel 102 is connected to the unloading connector 3. The main valve core 6 is slidably connected in the transverse channel 102 and can slide along the axis of the transverse channel 102. A control cavity 104 is formed between the right end of the main valve core 6, the inner wall of the transverse channel 102 and the pilot connecting plate 2. A channel combination structure is provided in the pilot connecting plate 2. The channel combination structure is connected to the control cavity 104 and introduces or exports low-pressure control fluid into the control cavity 104 to control the movement position of the main valve core 6.

[0018] The channel assembly structure includes a low-pressure inlet 201, a control fluid inlet 202, a first control fluid outlet 203, a second control fluid outlet 204, and a third control fluid outlet 205. The control fluid inlet 202 and the first control fluid outlet 203 are connected to the low-pressure inlet 201, forming a three-way structure. The low-pressure inlet 201 is located at the bottom of the pilot connecting plate 2 and is connected to the control fluid pump body. The control fluid inlet 202 is connected to the control chamber 104. The first control fluid outlet 203 and the third control fluid outlet 205... Both 204 penetrate the right end wall of the pilot connecting plate 2. A solenoid valve 5 is fixedly connected to the right end wall of the pilot connecting plate 2. The two ends of the solenoid valve 5 are connected to the control liquid outlet 1 203 and the control liquid outlet 2 204 respectively, and control the connection state between the control liquid outlet 1 203 and the control liquid outlet 2 204. The bottom end of the control liquid outlet 3 205 is connected to the control liquid outlet 2 204, and the top end of the control liquid outlet 3 205 penetrates the top end wall of the pilot connecting plate 2 and is connected to the control liquid return pipeline.

[0019] During normal fluid supply, the solenoid valve is closed. The control fluid entering through the low-pressure inlet enters the control chamber through the control fluid inlet. The liquid pressure in the control chamber increases and squeezes the main valve core to slide to the left. The left end of the main valve core blocks the internal channel of the unloading connector. The emulsion enters the drain check valve and is sent into the hydraulic support. When the supply pressure is too high, the solenoid valve is opened. The control fluid entering through the low-pressure inlet flows back through control fluid outlet 1, solenoid valve, control fluid outlet 2, and control fluid outlet 3. The liquid pressure in the control chamber is relatively low. The main valve core abuts against the left end wall of the pilot connecting plate under the action of the return spring. There is a gap between the left end of the main valve core and the internal channel of the unloading connector. The high-pressure emulsion flows back from the unloading connector to the emulsion tank through this gap, realizing the unloading operation of the high-pressure emulsion. Therefore, by controlling the opening and closing state of the solenoid valve, the position of the main valve core can be controlled by the low-pressure control fluid, thereby realizing the drainage and high-pressure unloading functions of the solenoid unloading valve.

[0020] The main valve core 6 is divided into a valve head section 601, a valve stem section 602, and a valve cap section 603 from left to right. The outer diameter of the valve stem section 602 is smaller than the outer diameter of the valve head section 601 and the valve cap section 603. The transverse channel 102 contains a first-stage variable diameter groove 1021, a second-stage variable diameter groove 1022, a third-stage variable diameter groove 1023, and a fourth-stage variable diameter groove 1024, which gradually increase in size from left to right. A first-stage variable diameter groove 1021 is fitted with a first sliding sleeve 7, which is sleeved on the outside of the valve head section 601. A pressure cap 8 is fixedly connected to the second-stage variable diameter groove 1022 by bolts, and the pressure cap 8 limits the position of the first sliding sleeve 7. The third-stage variable diameter groove 1022... A return spring 9 is fitted inside the diameter groove 1023. The return spring 9 and the pressure cap 8 are both fitted outside the valve stem section 602. The two ends of the return spring 9 abut against the inner wall of the left end of the three-stage diameter groove 1023 and the end wall of the left end of the valve cap section 603, respectively. A second sliding sleeve 10 is embedded in the four-stage diameter groove 1024. The second sliding sleeve 10 is fitted outside the valve cap section 603. The left end of the pilot connecting plate 2 is embedded in the four-stage diameter groove 1024 and abuts against the right end of the second sliding sleeve 10 to limit the position of the second sliding sleeve 10. The right end wall of the valve cap section 603, the inner wall of the second sliding sleeve 10, and the left end wall of the pilot connecting plate 2 together form a control cavity 104.

[0021] The valve cap section 603 is provided with a bolt clearance hole 604 that extends laterally through the valve cap section 603 to facilitate bolt fixing of the pressure plate 8; a sealing plug 11 is connected to the internal thread of the bolt clearance hole 604.

[0022] The main valve body 1 is provided with an unloading connector 3 at the left end, which is connected to the unloading return pipeline. The right end of the unloading connector 3 extends into the inner side of the left end of the transverse channel 102 and is threaded to the inner wall of the transverse channel 102. The inner diameter of the right end of the internal channel 301 of the unloading connector 3 is adapted to the outer diameter of the left end of the valve head section 601, so that the left end of the valve head section 601 can move to the left under the action of the control fluid in the control cavity 104 and block and seal the internal channel 301 of the unloading connector 3.

[0023] Sealing rings for improving sealing performance are provided between the outer peripheral sidewall of the valve head section 601 and the inner sidewall of the first sliding sleeve 7, between the outer peripheral sidewall of the valve cap section 603 and the inner sidewall of the second sliding sleeve 10, between the sealing plug 11 and the inner wall of the bolt clearance hole 604, between the left end wall of the pilot connecting plate 2 and the right end wall of the main valve body 1, and between the unloading connector 3 and the main valve body 1.

[0024] The inner diameter of the junction of the transverse and longitudinal channels is relatively large, allowing the main valve core to slide left and right within the transverse channel. When the main valve core slides to the left end of the transverse channel, it contacts and blocks the internal channel of the unloading connector. At this time, the main valve core does not obstruct the flow of the longitudinal channel, and the emulsion in the longitudinal channel normally enters the drain check valve. When the main valve core slides to the right end of the transverse channel under the elastic action of the return spring, the internal channel of the unloading connector is open, and the emulsion with excessive pressure will be discharged into the emulsion tank through the internal channel of the unloading connector, achieving the unloading effect of high-pressure emulsion.

[0025] A breather hole 103 is provided on the inner wall of the three-stage variable diameter groove 1023 to achieve pressure balance in the internal cavity when the main valve core 6 slides. The breather hole 103 penetrates the outer end wall of the main valve body 1.

[0026] The outer wall of the main valve core is sealed to the inner wall of the transverse channel. When the main valve core slides to the left, the space between the valve head and the gland becomes smaller, and the air in this space is discharged to the outside through the breather. When the main valve core slides to the right, the space between the valve head and the gland increases, and outside air enters this space through the breather, thus achieving the pressure balance effect when the main valve core slides left and right.

[0027] The top end of the longitudinal channel 101 is connected to the emulsion tank via an emulsion pump, and a drain check valve 4 is provided at the bottom end of the longitudinal channel 101. The drain check valve 4 is fixedly connected to the bottom end of the main valve body 1.

[0028] The drain check valve 4 includes a valve cover 42, a drain valve body 41, a drain valve core 43, and a drain spring 44. A piston chamber 411 is provided inside the drain valve body 41. The top end of the drain valve body 41 is fixedly connected to the bottom end of the main valve body 1 via the valve cover 42. A fluid passage hole 421 is provided on the valve cover 42. The top end of the piston chamber 411 communicates with the bottom end of the longitudinal channel 101 via the fluid passage hole 421. A connecting hole 412 is provided at the bottom end of the piston chamber 411 and communicates with the oil supply hole of the hydraulic support via the connecting hole 412. The drain valve core 43 is disposed inside the piston chamber 411 and can move longitudinally along the axis of the piston chamber 411. The drain valve core 43 is hollow inside, with the bottom end of the hollow structure penetrating the bottom end wall of the drain valve core 43. The top end of the drain valve core 43 is a tapered structure with a reduced diameter, and the side wall of the tapered structure has a side through hole 431 that communicates with the hollow structure inside the drain valve core 43. A drain gap 413 is formed between the outer side wall of the tapered structure and the inner side wall of the piston cavity 411. The drain spring 44 is located between the inner wall of the bottom end of the piston cavity 411 and the drain valve core 43. Under the elastic action of the drain spring 44, the top end of the drain valve core 43 abuts against the valve cover 42 and blocks and seals the through hole 421.

[0029] During normal fluid supply operation, the emulsion enters the fluid passage through the bottom end of the longitudinal channel and squeezes the top of the drain valve core. The drain valve core slides downward in the piston cavity, the drain spring is compressed, and the emulsion flows out from the connecting hole at the bottom end of the piston cavity through the drain gap, the side through hole, and the hollow structure inside the drain valve core in sequence, and is finally injected into the hydraulic support. When the supply pressure is low, the top of the drain valve core abuts against the bottom of the valve cover under the action of the drain spring and blocks the liquid inlet, so that the emulsion no longer enters the drain check valve.

[0030] During normal fluid supply operation, the electromagnetic unloading valve of this invention injects control fluid into the control chamber through the channel assembly structure within the pilot connecting plate. This control fluid forces the main valve core to move to the left within the transverse channel, blocking the internal channel of the unloading connector. The emulsion pump then delivers the emulsion through the top of the longitudinal channel into the longitudinal channel, and after passing through the drain check valve, it is supplied to the hydraulic support. When the supply pressure is too high, the control fluid in the control chamber flows back through the channel assembly structure within the pilot connecting plate. The right end of the main valve core, under the elastic action of the return spring, abuts against the left end wall of the pilot connecting plate. The left end of the main valve core does not block the internal channel of the unloading connector. The high-pressure emulsion flows back into the emulsion tank after passing through the unloading connector. The low-pressure control fluid effectively realizes the discharge and high-pressure unloading functions of the electromagnetic unloading valve by controlling the outflow and inflow of the control chamber. It does not require pneumatic control of the position of the main valve core, avoiding cavitation damage caused by long-term pneumatic control, extending the service life of the electromagnetic unloading valve, ensuring the stable operation of the electromagnetic unloading valve, keeping the pressure of the pump station's liquid supply system stable, and effectively improving the stable liquid supply and support effect of the hydraulic support.

Claims

1. A low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump, comprising a main valve body and a main valve core, wherein the main valve core is slidably disposed within the main valve body and controls the internal conduction state of the main valve body; characterized in that: A pilot connecting plate is fixedly connected to the right end of the main valve body. The main valve body is provided with a longitudinal channel that runs through the main valve body and a transverse channel that runs through the main valve body. The longitudinal channel and the transverse channel are intersected and interconnected. The left end of the transverse channel is connected to the unloading connector. The main valve core is slidably connected in the transverse channel and can slide along the axis of the transverse channel. A control cavity is formed between the right end of the main valve core, the inner wall of the transverse channel and the pilot connecting plate. A channel combination structure is provided in the pilot connecting plate. The channel combination structure is connected to the control cavity and introduces or exports low-pressure control fluid into or out of the control cavity to control the movement position of the main valve core.

2. The low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump as described in claim 1, characterized in that: The channel assembly structure includes a low-pressure inlet, a control fluid inlet, a control fluid outlet 1, a control fluid outlet 2, and a control fluid outlet 3. The control fluid inlet and control fluid outlet 1 are connected to the low-pressure inlet to form a three-way structure. The low-pressure inlet is located at the bottom of the pilot connecting plate and is connected to the control fluid pump body. The control fluid inlet is connected to the control chamber. Control fluid outlet 1 and control fluid outlet 2 both penetrate the right end wall of the pilot connecting plate. A solenoid valve is fixedly connected to the right end wall of the pilot connecting plate. The two ends of the solenoid valve are respectively connected to control fluid outlet 1 and control fluid outlet 2 and control the connection state between control fluid outlet 1 and control fluid outlet 2. The bottom end of control fluid outlet 3 is connected to control fluid outlet 2, and the top end of control fluid outlet 3 penetrates the top end wall of the pilot connecting plate and is connected to the control fluid return pipeline.

3. The low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump as described in claim 1, characterized in that: The main valve core is divided into a valve head section, a valve stem section, and a valve cap section from left to right. The outer diameter of the valve stem section is smaller than that of the valve head section and the valve cap section. A first-stage variable diameter groove, a second-stage variable diameter groove, a third-stage variable diameter groove, and a fourth-stage variable diameter groove are arranged in the transverse channel, progressively increasing in size from left to right. A first sliding sleeve is embedded in the first-stage variable diameter groove and is fitted onto the outside of the valve head section. A pressure cap is fixedly connected to the second-stage variable diameter groove, limiting the position of the first sliding sleeve. The third-stage variable diameter groove is fitted with... A return spring is provided, and both the return spring and the pressure cap are sleeved on the outside of the valve stem section. The two ends of the return spring abut against the inner wall of the left end of the three-stage reducing groove and the end wall of the left end of the valve cap section, respectively. A second sliding sleeve is embedded in the four-stage reducing groove and is sleeved on the outside of the valve cap section. The left end of the pilot connecting plate is embedded in the four-stage reducing groove and abuts against the right end of the second sliding sleeve to limit the position of the second sliding sleeve. The right end wall of the valve cap section, the inner wall of the second sliding sleeve, and the left end wall of the pilot connecting plate together form a control cavity.

4. The low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump as described in claim 3, characterized in that: The valve cap section is provided with a bolt clearance hole that extends horizontally through the valve cap section to facilitate bolt fixing of the gland; a sealing plug is threaded into the bolt clearance hole.

5. The low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump as described in claim 4, characterized in that: The main valve body is provided with an unloading connector on the left end, which is connected to the unloading return pipeline. The right end of the unloading connector extends into the inner side of the left end of the transverse channel and is threaded to the inner wall of the transverse channel. The inner diameter of the right end of the internal channel of the unloading connector is adapted to the outer diameter of the left end of the valve head section, so that the left end of the valve head section can move to the left under the action of the control fluid in the control cavity and block and seal the internal channel of the unloading connector.

6. The low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump as described in claim 5, characterized in that: Sealing rings for improving sealing performance are provided between the outer peripheral sidewall of the valve head section and the inner sidewall of the first sliding sleeve, between the outer peripheral sidewall of the valve cap section and the inner sidewall of the second sliding sleeve, between the sealing plug and the inner wall of the bolt clearance hole, between the left end wall of the pilot connecting plate and the right end wall of the main valve body, and between the unloading joint and the main valve body.

7. The low-pressure control electromagnetic unloading valve for a high-flow, long-life emulsion pump as described in claim 6, characterized in that: The inner wall of the three-stage variable diameter groove is provided with a breather hole to achieve pressure balance in the internal cavity when the main valve core slides. The breather hole penetrates the outer end wall of the main valve body.

8. The low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump as described in claim 1, characterized in that: The top of the longitudinal channel is connected to the emulsion tank via an emulsion pump, and a drain check valve is installed at the bottom of the longitudinal channel. The drain check valve is fixedly connected to the bottom of the main valve body.

9. The low-pressure control electromagnetic unloading valve for a high-flow-rate, long-life emulsion pump as described in claim 8, characterized in that: The drain check valve includes a valve cover, a drain valve body, a drain valve core, and a drain spring. A piston chamber is provided within the drain valve body. The top of the drain valve body is fixedly connected to the bottom of the main valve body via the valve cover. The valve cover has a fluid passage hole. The top of the piston chamber communicates with the bottom of a longitudinal channel via the fluid passage hole. The bottom of the piston chamber has a connecting hole that communicates with the oil supply hole of the hydraulic support. The drain valve core is located within the piston chamber and can slide longitudinally along the axis of the piston chamber. The part is configured as a hollow structure, with the bottom end of the hollow structure penetrating the bottom end wall of the drain valve core. The top end of the drain valve core is configured as a reduced-diameter conical structure, and the side wall of the reduced-diameter conical structure is provided with a side through hole that communicates with the hollow structure inside the drain valve core. A drain gap is formed between the outer wall of the reduced-diameter conical structure and the inner wall of the piston cavity. The drain spring is disposed between the inner wall of the bottom end of the piston cavity and the drain valve core, and under the elastic action of the drain spring, the top end of the drain valve core abuts against the valve cover and blocks and seals the through hole.

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