A mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core

Abstract

This invention provides a high-flow-rate hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core for mining applications. It includes a main valve sleeve with a threaded sleeve at one end and a threaded plug at the other. A working section is located in the middle of the main valve sleeve, with an inlet chamber and a return chamber formed on opposite sides of the working section. An inlet control kit is installed in the inlet chamber, and a return chamber control kit is installed in the return chamber. An inlet port communicating with the inlet chamber and a return port communicating with the return chamber are located on the side wall of the main valve sleeve. A push rod is slidably installed in the central hole of the working section, and this push rod is pushed by either the inlet seal or the return seal. The working section has an inlet-side working port communicating with the inlet chamber and a return-side working port communicating with the return chamber. The ball-cone sealing structure used in this invention can be used in high-flow-rate directional valves, achieving a high-flow-rate ball-cone seal and improving the reliability of the mining electro-hydraulic directional valve core in field use.

Description

Technical Field

[0001] This invention belongs to the technical field of hydraulic support equipment for coal mine fully mechanized mining, and in particular relates to a high-flow hydraulic balance ball cone hard seal electro-hydraulic control directional valve core for mining. Background Technology

[0002] With the increasing prevalence of automated coal mining faces, the hydraulic supports used for longwall mining have evolved from manual directional valves controlling the movement of individual cylinders to electro-hydraulic directional valves. The directional valve core in the electro-hydraulic directional control system is the primary hydraulic component driving the cylinders. Traditional electro-hydraulic main valve cores use soft seals, achieved through contact between metal and non-metal components. However, with the increasing working pressure and flow rate of hydraulic fluid in mines, the mechanical properties of non-metallic seals are insufficient to withstand the high pressure and high flow rate, significantly reducing their service life. Furthermore, due to fluid dynamics, the opening of ball-cone seal valve cores requires precise dimensional control; otherwise, proper reset is impossible, limiting their application to low-flow pilot valves. During valve spool reversing, the inlet and outlet fluids are connected. Existing valve spool structures require strict control over the valve spool opening size, with the opening designed to be as small as possible. Generally, the gap at the opening of an 18mm diameter ball seal needs to be less than 0.15mm. If the valve spool opening is too large, the sealing ball will vibrate under hydraulic force, leading to sealing failure and damage to the sealing surface. Therefore, existing valve spools of this type mostly avoid this by reducing or controlling the opening amount. Due to the limitation of the opening amount, the flow rate of ball seal valve spools is relatively small, making it difficult to operate stably under heavy-load, high-flow conditions for extended periods. Therefore, it is necessary to improve existing reversing valves to enhance their adaptability to high flow rates and extend their service life. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes a high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic control directional valve core for mining.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core for mining applications includes a main valve sleeve with a threaded sleeve installed at one end and a threaded plug installed at the other end. The main valve sleeve has a working section in the middle, and an inlet chamber and a return chamber are formed on both sides of the working section inside the main valve sleeve. An inlet control kit is installed in the inlet chamber, and a return chamber control kit is installed in the return chamber. An inlet port communicating with the inlet chamber and a return port communicating with the return chamber are both provided on the side wall of the main valve sleeve. A push rod is slidably installed in the center hole of the working section. The push rod is pushed by the liquid inlet seal or the liquid return seal to realize the linkage between the liquid inlet control kit and the liquid return control kit. The working section is provided with a liquid inlet working port connected to the liquid inlet chamber and a liquid return working port connected to the liquid return chamber. The liquid inlet chamber control kit includes a liquid inlet slide and a liquid inlet seal. The liquid inlet slide slides against the inner wall of the liquid inlet chamber, and a spring is provided between the liquid inlet slide and the screw plug. The liquid inlet seal is installed on the liquid inlet slide. The liquid return chamber control kit includes a piston and a liquid return seal. A piston sleeve is fitted on the outside of the piston, and the liquid return seal is installed on the piston. The piston sleeve slides against the piston, and a piston seal is provided between them. The piston sleeve slides against the inner wall of the liquid return chamber, and a piston sleeve seal is provided between them. The threaded sleeve includes a body, with a cylindrical connecting section inside the body and a positioning boss on the inner end face of the body. The outer diameter of the positioning boss is smaller than the inner diameter of the piston sleeve. A valve core control cavity is provided between the piston and the threaded sleeve. A control port communicating with the valve core control cavity is provided on the side wall of the main valve sleeve. A liquid-passing ring groove is formed between the connecting section and the main valve sleeve, and a control liquid inlet communicating with the liquid-passing ring groove is provided on the side wall of the connecting section.

[0005] Furthermore, the liquid inlet seal includes a liquid inlet sealing ball, and a liquid inlet sealing port that cooperates with the liquid inlet sealing ball is provided on the working section.

[0006] Furthermore, when the liquid inlet seal is closed to the liquid inlet sealing port, the liquid inlet seal does not form a seal on the working liquid port on the liquid inlet side; when the liquid inlet seal is not closed to the liquid inlet sealing port, the liquid inlet is connected to the working liquid port on the liquid inlet side.

[0007] Furthermore, the return fluid seal includes a return fluid sealing ball, and a return fluid sealing port that cooperates with the return fluid sealing ball is provided on the working section.

[0008] Furthermore, when the return fluid seal is closed to the return fluid sealing port, the return fluid seal does not form a seal on the return fluid side working fluid port; when the return fluid seal is not closed to the return fluid sealing port, the return fluid side working fluid port is connected to the return fluid port.

[0009] Furthermore, all edges of the piston, piston sleeve, and inlet slide are chamfered to facilitate assembly and prevent scratches on parts. As a further improvement, the piston and piston sleeve are chamfered on the side facing the threaded sleeve, thereby forming a larger starting area at the starting end of the piston and piston sleeve. In addition, the designed valve core control chamber effectively reduces the starting pressure of the control fluid when the valve core moves, resulting in better performance.

[0010] Furthermore, the inlet, return port, control port, inlet-side working liquid port, and return-side working liquid port are all evenly distributed around the axis of the main valve sleeve.

[0011] Furthermore, the outer wall of the main valve sleeve is provided with a first mating platform and a second mating platform on both sides of the working section. A first valve core seal is installed on the outer edge of the first mating platform, and a second valve core seal is installed on the outer edge of the second mating platform, forming an inlet annular cavity between the first and second mating platforms. The outer wall of the main valve sleeve is provided with a third mating platform near the screw sleeve. A third valve core seal is provided on the outer wall of the third mating platform, forming a return annular cavity between the third valve core seal and the second valve core seal.

[0012] Furthermore, both the liquid inlet sealing port and the liquid return sealing port are cone-shaped structures, and a sealing working surface adapted to the corresponding sealing element is provided on the inner wall of the cone-shaped structure.

[0013] Furthermore, the outer wall of the screw sleeve is provided with a screw sleeve seal, and an external threaded connection structure is provided at the end of the screw sleeve away from the main valve sleeve.

[0014] Compared with existing technologies, the present invention has the following advantages: The ball-cone sealing structure used in this invention allows the control fluid to flow into the main valve core through the valve core control port. The control fluid first pushes the piston sleeve to move, and then pushes the piston to move. This results in lower piston opening and closing pressure and a more stable opening and closing process. Furthermore, during reversal, the piston sleeve, due to its lower resistance, moves first, contacting the main valve sleeve to cut off the return fluid path. This effectively eliminates the influence of hydraulic force on the valve core's opening, allowing for a larger valve core opening and a higher valve core flow rate. Additionally, the inlet slide in this reversing valve core overcomes the influence of hydraulic force caused by the connection between the inlet and return fluids, effectively improving sealing performance and overcoming the defect of vibration in the sealing ball of existing technologies. Therefore, this reversing valve core can be used in high-flow-rate reversing main valves, achieving high-flow-rate ball-cone sealing and improving the reliability of mine electro-hydraulic control reversing valve cores in field applications. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the reversing valve core in the neutral position state of the present invention; Figure 2 This is a schematic diagram of the working position of the reversing valve core of the present invention; Figure 3 This is a schematic diagram of the process by which the reversing valve core of the present invention returns from the working position to the neutral position; Figure 4 A schematic diagram of the threaded sleeve in this invention; Figure 5 This is a schematic diagram of the liquid inlet slide of the present invention. Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] A type of high-flow-rate hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core for mining applications, such as... Figures 1 to 5 As shown, the device includes a main valve sleeve 1, with a threaded sleeve 2 installed at one end and a threaded plug 3 installed at the other end. A working section 4 is provided in the middle of the main valve sleeve, and an inlet chamber 5 and a return chamber 6 are formed on both sides of the working section inside the main valve sleeve. An inlet control kit 7 is installed in the inlet chamber, and a return chamber control kit 8 is installed in the return chamber. An inlet port 9 communicating with the inlet chamber and a return port 10 communicating with the return chamber are provided on the side wall of the main valve sleeve. A push rod 11 is slidably installed in the center hole of the working section. This push rod is pushed by an inlet seal or a return seal (from the side with higher hydraulic pressure to the side with lower pressure) to achieve linkage between the inlet control kit and the return control kit. An inlet-side working port 12 communicating with the inlet chamber and a return-side working port 13 communicating with the return chamber are provided on the working section.

[0021] The liquid inlet chamber control kit includes a liquid inlet slide 14 and a liquid inlet seal 15. The liquid inlet slide slides in conjunction with the inner wall of the liquid inlet chamber, and a spring 16 is provided between the liquid inlet slide and the screw plug. The liquid inlet seal is installed on the liquid inlet slide. The liquid return chamber control kit includes a piston 17 and a liquid return seal 18. A piston sleeve 19 is fitted on the outside of the piston, and the liquid return seal is installed on the piston. The piston sleeve slides in conjunction with the piston, and a piston seal 20 is provided between them. The piston sleeve slides in conjunction with the inner wall of the liquid return chamber, and a piston sleeve seal 21 is provided between them. As an example, the liquid inlet slide includes a seat part 41 and a mounting part 42. The outer diameter of the seat part is smaller than the outer diameter of the mounting part. A slide positioning platform 43 is formed between the seat part and the mounting part. A spring is fitted on the seat part, and the end of the spring abuts against the slide positioning platform. The liquid inlet seal is installed on the mounting part.

[0022] The threaded sleeve includes a body 22, with a cylindrical connecting section 23 inside the body and a positioning boss 24 on the inner end face of the body (facing the return fluid control kit). The outer diameter of the positioning boss is smaller than the inner diameter of the piston sleeve. The non-bore area on the inner end face of the body serves as a working surface 25 for positioning the piston sleeve. A valve core control cavity 26 is provided between the piston and the threaded sleeve. A control port 27 communicating with the valve core control cavity is provided on the side wall of the main valve sleeve. A liquid-passing ring groove 28 is formed between the connecting section and the main valve sleeve. A control fluid inlet 29 communicating with the liquid-passing ring groove is provided on the side wall of the connecting section to ensure that the control fluid can smoothly enter the control fluid inlet of the connecting section through the control port of the main valve sleeve, thereby reducing the difficulty of valve core assembly. The control port and the control fluid inlet do not need to be aligned to achieve control fluid conduction.

[0023] The aforementioned liquid inlet seal includes a liquid inlet sealing ball, and a liquid inlet sealing port 30 that mates with the liquid inlet sealing ball is provided on the working section. When the liquid inlet seal and the liquid inlet sealing port are closed, the liquid inlet seal does not form a seal on the working liquid port on the liquid inlet side; when the liquid inlet seal and the liquid inlet sealing port are not closed, the liquid inlet is connected to the working liquid port on the liquid inlet side. The aforementioned liquid return seal includes a liquid return sealing ball, and a liquid return sealing port 31 that mates with the liquid return sealing ball is provided on the working section.

[0024] When the return fluid seal is closed to the return fluid sealing port, the return fluid seal does not seal the working fluid port on the return fluid side; when the return fluid seal is not closed to the return fluid sealing port, the working fluid port on the return fluid side is connected to the return fluid port. For example, the inlet sealing ball and the return fluid sealing ball are ceramic balls with a hardness of HRC70 or higher, and the main valve sleeve is made of stainless steel and heat-treated to a hardness of HRC45 or higher. Due to the high hardness of the seals, they can withstand not only higher hydraulic pressure but also higher flow impacts, thus improving product lifespan.

[0025] All edges of the piston, piston sleeve, and inlet slide are chamfered for easy assembly and to prevent scratches. As a further improvement, the piston and piston sleeve have a chamfered angle 32 on the side facing the threaded sleeve, thus creating a larger starting area at the starting end of the piston and piston sleeve. Combined with the designed valve core control chamber (which is the annular cavity outside the piston and boss when the piston and threaded sleeve are in contact), this effectively reduces the starting pressure of the control fluid when the valve core actuates, resulting in better performance. The outer wall of the threaded sleeve is provided with a threaded sleeve seal 38, and an external threaded connection structure 39 is provided at the end of the threaded sleeve away from the main valve sleeve.

[0026] The outer wall of the main valve sleeve is provided with a first mating platform and a second mating platform on both sides of the working section. A first valve core seal 33 is installed on the outer edge of the first mating platform, and a second valve core seal 34 is installed on the outer edge of the second mating platform. An inlet annular cavity 35 is formed between the first and second mating platforms. A third mating platform is provided at one end of the outer wall of the main valve sleeve near the screw sleeve. A third valve core seal 36 is provided on the outer wall of the third mating platform. A return annular cavity 37 is formed between the third valve core seal and the second valve core seal.

[0027] The aforementioned inlet, return, control, inlet-side working fluid port, and return-side working fluid port are all evenly distributed around the axis of the main valve sleeve, with several in each case. For example, each opening typically has 5-10 inlets. Both the inlet and return sealing ports are conical structures, with a sealing working surface (compatible with the corresponding sealing element) on the inner wall of the conical structure. As a further improvement, a wear-resistant coating can be applied to the inner wall of the conical structure to enhance wear resistance and extend service life. The ball-cone sealing structure used in this invention allows the directional valve core to be used in high-flow-rate directional valves, achieving high-flow-rate ball-cone sealing and improving the reliability of mine electro-hydraulic directional valve cores in field applications.

[0028] In an optional embodiment, the threaded sleeve and the main valve sleeve are connected by a retaining ring 40, which integrates the threaded sleeve and the main valve sleeve and allows relative rotation between them. This structure allows the threaded sleeve to rotate while the main valve sleeve does not rotate during valve core assembly and disassembly. As the threaded sleeve screws into the main valve sleeve, it generates axial movement that pushes the valve core in. The assembly operation is simple and does not easily damage the valve core.

[0029] like Figure 1 The diagram shows the directional valve core in the neutral position. In this position, the inlet sealing ball contacts the main valve sleeve under the action of hydraulic pressure and spring force, sealing the high-pressure fluid on the right side of the inlet sealing ball. The return sealing ball is separated from the main valve sleeve, and the working fluid is connected to the return fluid.

[0030] like Figure 2The diagram shows the working position of the directional valve core. When the control fluid flows into the main valve core through the control port, the piston is resisted by the hydraulic pressure and spring force transmitted through the inlet sealing ball, push rod, and return sealing ball, while the piston sleeve is not subject to any resistance. Therefore, the control fluid first pushes the piston sleeve to the right, making it contact the main valve sleeve. Then, the control fluid pushes the piston to drive the return sealing ball to contact the main valve sleeve, while the inlet sealing ball separates from the main valve sleeve. The high-pressure fluid flows into the working fluid port through the inlet and then into each cylinder of the hydraulic support. The high-pressure fluid causes the cylinder to contract or extend, driving the hydraulic support to achieve the support action.

[0031] It should be noted that during the valve core reversal process, there is a state where the inlet and outlet fluids are connected when neither ball is sealed. In this state, existing technologies must control the valve core opening and make it as small as possible. According to relevant papers and actual verification, if the ball diameter is 18mm, the ball sealing opening needs to be ≤0.15mm. If the valve core opening is too large, the two balls will vibrate under the action of hydraulic force, resulting in failure to seal and damage to the sealing surface. Therefore, most existing valve cores of this type avoid this situation by reducing or controlling the opening. Due to the limitation of the opening, the flow rate of valve cores with ball sealing structures is relatively small.

[0032] This invention adds a piston sleeve as a structural component. During reversal, the piston sleeve experiences less resistance (the resistance experienced by the piston sleeve is even less than that of the piston), so the piston sleeve moves first, causing its right end face to contact the main valve sleeve. This cuts off the return fluid passage, eliminating the connection between the inlet and return fluids and preventing the influence of hydraulic force on the valve core opening. The valve core opening can be made larger than 5mm, and the valve core flow rate can reach up to 500L / min. This effectively overcomes the limitations of small flow valve core applications in the prior art. The valve core provided by this invention has higher operational reliability and a guaranteed service life.

[0033] like Figure 3 The diagram illustrates the process of the directional valve core returning from the working position to the neutral position. The pressure in the left cavity of the piston and piston sleeve disappears. Due to the spring's return, the inlet slide and inlet sealing ball are pushed towards the direction of closing the inlet. When the return sealing ball disengages from the main valve sleeve, the hydraulic pressure on the right end of the piston sleeve causes it to disengage from the main valve sleeve, resulting in a connection between the inlet and return fluids. Because the opening of this product is >5mm, an inlet slide with a booster function is specially designed to prevent the sealing ball from failing to seal or vibrating. Its function is to overcome the hydraulic force caused by the connection between the inlet and return fluids.

[0034] It should be noted that because the gap between the inlet slide and the inner hole of the main valve sleeve is very small (0.2mm), the hydraulic pressure on the right side of the inlet sealing ball increases. This causes the inlet sealing ball to be subjected to both the spring return force and the hydraulic thrust. Under the simultaneous action of the two forces, the inlet sealing ball can contact the main valve sleeve at a faster speed, cutting off the connection between the inlet and return fluids, thereby reducing valve core damage caused by valve core vibration.

[0035] The ball-cone sealing structure used in this invention allows the control fluid to flow into the main valve core through the valve core control port. The control fluid first pushes the piston sleeve to move, and then pushes the piston to move. This results in lower piston opening and closing pressure and a more stable opening and closing process. Furthermore, during reversal, the piston sleeve, due to its lower resistance, moves first, contacting the main valve sleeve to cut off the return fluid path. This effectively eliminates the influence of hydraulic force on the valve core's opening, allowing for a larger valve core opening and a higher valve core flow rate. Additionally, the inlet slide in this reversing valve core overcomes the influence of hydraulic force caused by the connection between the inlet and return fluids, effectively improving sealing performance and overcoming the defect of vibration in the sealing ball of existing technologies. Therefore, this reversing valve core can be used in high-flow-rate reversing main valves, achieving high-flow-rate ball-cone sealing and improving the reliability of mine electro-hydraulic control reversing valve cores in field applications.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-flow-rate hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core for mining applications, comprising a main valve sleeve, wherein a threaded sleeve is installed at one end of the main valve sleeve and a threaded plug is installed at the other end; characterized in that: The main valve sleeve has a working section in the middle, and an inlet chamber and a return chamber are formed on both sides of the working section inside the main valve sleeve respectively; an inlet control kit is installed in the inlet chamber, and a return control kit is installed in the return chamber; an inlet port communicating with the inlet chamber is provided on the side wall of the main valve sleeve, and a return port communicating with the return chamber is provided on the side wall of the main valve sleeve. A push rod is slidably installed in the center hole of the working section. The push rod is pushed by the liquid inlet seal or the liquid return seal to realize the linkage between the liquid inlet control kit and the liquid return control kit. The working section is provided with a liquid inlet working port connected to the liquid inlet chamber and a liquid return working port connected to the liquid return chamber. The liquid inlet control kit includes a liquid inlet slide and a liquid inlet seal. The liquid inlet slide slides against the inner wall of the liquid inlet chamber, and a spring is provided between the liquid inlet slide and the screw plug. The liquid inlet seal is installed on the liquid inlet slide. The liquid return control kit includes a piston and a liquid return seal. A piston sleeve is fitted on the outside of the piston, and the liquid return seal is installed on the piston. The piston sleeve slides against the piston, and a piston seal is provided between them. The piston sleeve slides against the inner wall of the liquid return chamber, and a piston sleeve seal is provided between them. The threaded sleeve includes a body, a cylindrical connecting section inside the body, and a positioning boss on the inner end face of the body. The outer diameter of the positioning boss is smaller than the inner diameter of the piston sleeve. A valve core control cavity is provided between the piston and the threaded sleeve. A control port communicating with the valve core control cavity is provided on the side wall of the main valve sleeve. A liquid-passing ring groove is formed between the connecting section and the main valve sleeve. A control liquid inlet communicating with the liquid-passing ring groove is provided on the side wall of the connecting section. The liquid inlet slide includes a seat body and a mounting part. The outer diameter of the seat body is smaller than the outer diameter of the mounting part. A slide positioning platform is formed between the seat body and the mounting part. A spring is fitted onto the seat body, and the end of the spring abuts against the slide positioning platform. A liquid inlet seal is installed on the mounting part. The liquid inlet seal includes a liquid inlet sealing ball. The liquid return seal includes a liquid return sealing ball. When the control fluid flows into the main valve core through the control port, the piston is resisted by the hydraulic pressure and spring force transmitted through the inlet sealing ball, push rod and return sealing ball, while the piston sleeve is not subject to any resistance. Therefore, the control fluid will first push the piston sleeve to the right to make it contact the main valve sleeve. Then the control fluid will push the piston to drive the return sealing ball to contact the main valve sleeve, while the inlet sealing ball will separate from the main valve sleeve. Because the gap between the inlet slide and the inner hole of the main valve sleeve is 0.2mm, the hydraulic pressure on the right side of the inlet sealing ball increases. As a result, the inlet sealing ball is subjected to both the spring return force and the hydraulic thrust. Under the simultaneous action of the two forces, the inlet sealing ball contacts the main valve sleeve, cutting off the connection between the inlet and return fluids.

2. The mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 1, characterized in that: The working section is equipped with a liquid inlet sealing port that mates with the liquid inlet sealing ball.

3. The mining high-flow hydraulic balance ball-cone hard-seal electro-hydraulic directional valve core according to claim 2, characterized in that: When the liquid inlet seal is not closed to the liquid inlet port, the liquid inlet is connected to the working liquid inlet on the liquid inlet side.

4. The mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 2, characterized in that: The working section is equipped with a return liquid sealing port that mates with the return liquid sealing ball.

5. The mining high-flow hydraulic balance ball-cone hard-seal electro-hydraulic directional valve core according to claim 4, characterized in that: When the return fluid seal and the return fluid sealing port are not closed, the working fluid port on the return fluid side is connected to the return fluid port.

6. The mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 1, characterized in that: The piston, piston sleeve, and inlet slide are all chamfered at their corners.

7. The mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 1, characterized in that: The inlet, outlet, control port, inlet-side working liquid port, and outlet-side working liquid port are all evenly distributed around the axis of the main valve sleeve.

8. The mining high-flow hydraulic balance ball-cone hard-seal electro-hydraulic directional valve core according to claim 1, characterized in that: The outer wall of the main valve sleeve is provided with a first mating platform and a second mating platform on both sides of the working section. A first valve core seal is installed on the outer edge of the first mating platform, and a second valve core seal is installed on the outer edge of the second mating platform, forming an inlet annular cavity between the first and second mating platforms. The outer wall of the main valve sleeve is provided with a third mating platform near the screw sleeve. A third valve core seal is provided on the outer wall of the third mating platform, forming a return annular cavity between the third valve core seal and the second valve core seal.

9. A mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 4, characterized in that: Both the liquid inlet sealing port and the liquid return sealing port have a conical hole structure, and a sealing working surface is provided on the inner wall of the conical hole structure.

10. The mining high-flow hydraulically balanced ball-cone hard-seal electro-hydraulic directional valve core according to claim 1, characterized in that: The outer wall of the screw sleeve is provided with a screw sleeve seal, and an external threaded connection structure is provided at the end of the screw sleeve away from the main valve sleeve.

Images