High-pressure pilot electromagnetic valve

Abstract

The utility model discloses a high-pressure pilot electromagnetic valve which comprises a valve body, a valve rod and a piston assembly. The valve body is provided with an inlet, an outlet and an inner cavity, and the inlet and the outlet are both communicated with the inner cavity; the piston assembly is contained in the inner cavity of the valve body, and the piston assembly is configured to be capable of moving towards the outlet or moving in the direction away from the outlet; the inner cavity is divided into a fluid cavity and a pilot cavity by the piston assembly, and the inlet and the outlet are both communicated with the fluid cavity; the piston assembly is provided with a through piston valve port, the piston valve port is communicated with the pilot cavity, and the piston valve port corresponds to the outlet; a piston spring is arranged between the piston assembly and the inner wall of the fluid cavity; at least one end of the valve rod extends into the pilot cavity, and the valve rod is configured to move towards the piston valve port and abut against the piston valve port in a sealed mode or move in the direction away from the piston valve port and move away from the piston valve port. The piston assembly is designed in a decoupling mode, and the piston valve plays a role in inlet and outlet sealing and pilot sealing at the same time.

Description

Technical Field

[0001] The utility model relates to the field of electromagnetic valves, in particular to a high-pressure pilot electromagnetic valve. Background Art

[0002] In the solenoid valve of the prior art, such as that in Patent 200880125482.6, the piston and the valve stem are connected and act together, the valve opening ability is unstable, and the performance of the product is unstable.

[0003] For example, in patent 201310003757.1, the moving iron core has a stopper, which cooperates with the pilot needle valve body. It has a small flow area, high processing difficulty, and a small stroke of the solenoid valve, which has many disadvantages.

[0004] The piston seal at the bottom of the piston in patent 202011378521.2 is difficult to adapt to the actual high-pressure and high-flow rate use environment and is easy to fall out, causing the solenoid valve to fail and become unusable.

[0005] In addition, there are solenoid valves on the market that use tower spring technology between the iron cores, and the tower spring can easily cause the tower yellow to fall out.

[0006] In view of the above situation, it is necessary to propose a new technical solution. Utility Model Content

[0007] In order to solve at least one of the technical problems existing in the prior art, the utility model proposes a high-pressure pilot solenoid valve. The specific scheme is as follows:

[0008] The utility model provides a high-pressure pilot electromagnetic valve, comprising a valve body, a valve stem and a piston assembly;

[0009] The valve body is provided with an inlet, an outlet and an inner cavity, and the inlet and the outlet are both connected to the inner cavity;

[0010] The piston assembly is accommodated in the cavity of the valve body, and the piston assembly is configured to be able to move toward the outlet or move in a direction away from the outlet;

[0011] The inner cavity is divided into a fluid cavity and a pilot cavity by the piston assembly, and the inlet and the outlet are both connected to the fluid cavity;

[0012] A through piston valve port is provided on the piston assembly, the piston valve port is communicated with the pilot cavity, and the piston valve port corresponds to the outlet;

[0013] A piston spring is arranged between the piston assembly and the inner wall of the fluid chamber;

[0014] At least one end of the valve stem extends into the pilot cavity, and the valve stem is configured to be able to move toward the piston valve port and seal against the piston valve port or move in a direction away from the piston valve port and move away from the piston valve port.

[0015] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, the piston assembly includes a piston seat and a piston valve, and the piston valve is arranged on the piston seat;

[0016] The inner cavity is divided into a fluid cavity and a pilot cavity by a piston seat;

[0017] A through piston valve port is provided on the piston valve, and the piston valve port is communicated with the pilot cavity.

[0018] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, a balancing hole is opened on the piston assembly, one end of the balancing hole is connected to the fluid cavity, and the other end is connected to the pilot cavity.

[0019] As a preferred solution of the high-pressure pilot electromagnetic valve described in the utility model, the inner diameter of the piston valve port is larger than the inner diameter of the balance hole.

[0020] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, the valve stem is a pilot valve needle.

[0021] As a preferred solution of the high-pressure pilot electromagnetic valve described in the utility model, it also includes a sleeve, the sleeve is fixed on the valve body, and one end of the valve stem away from the piston valve port is accommodated in the sleeve.

[0022] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, it also includes a moving iron core, which is accommodated in the sleeve, and the end of the valve stem away from the piston assembly is fixed on the moving iron core, and the moving iron core is configured to move toward the direction close to the piston assembly or move toward the direction away from the piston assembly.

[0023] As a preferred solution of the high-pressure pilot electromagnetic valve described in the utility model, it also includes a static iron core, which is fixed in the sleeve, and a pilot spring is arranged between the static iron core and the moving iron core.

[0024] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, the pilot spring is a spring of equal diameter.

[0025] As a preferred solution of the high-pressure pilot electromagnetic valve described in the utility model, the piston valve is detachably connected to the piston seat.

[0026] As a preferred solution of the high-pressure pilot electromagnetic valve described in the utility model, the piston valve is made of plastic or metal.

[0027] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, a lubrication groove is opened on the inner wall of the valve body cavity or the piston assembly, and a lubrication ring is placed in the lubrication groove, and the lubrication ring is configured to lubricate the movement of the piston assembly.

[0028] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, a convex ring is radially arranged around the surface of the valve body, and a first sealing ring is sleeved on the surface of the valve body. The first sealing ring is sleeved on the side of the convex ring close to the opening.

[0029] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, a second sealing ring is sleeved on the surface of the valve body, and the second sealing ring is located at one end of the valve body surface close to the outlet.

[0030] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, the piston spring is a spring of equal diameter.

[0031] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, a spring groove is provided on one side of the piston assembly close to the outlet, the opening of the spring groove is arranged opposite to the outlet, and the other end of the piston spring is accommodated in the spring groove.

[0032] As a preferred solution of the high-pressure pilot solenoid valve described in the utility model, the other end of the piston spring includes a contact surface and a first surface, the spring groove includes a side wall, and the contact surface contacts the side wall;

[0033] The side wall of the spring groove is also provided with a stop protrusion, and the first surface of the piston spring contacts the stop protrusion.

[0034] Among the above technical solutions, the one provided by the utility model has at least the following beneficial effects compared with the prior art:

[0035] The utility model has a decoupled piston assembly design, and the piston valve acts as a refrigerant or other fluid inlet and outlet seal and a pilot seal. At the same time, the switch valve of this technical solution has both the cooperation of the moving iron core and the piston spring and the cooperation of the fluid pressure difference, making the switch valve smoother, energy-saving, stable and excellent in performance.

[0036] The piston valve can be detachably mounted on the piston seat. When replacing the piston valve port with a different matching caliber according to actual needs, it is only necessary to replace the piston valve, which is convenient for disassembly and assembly and saves the cost of accessories.

[0037] The piston valve can be made of plastic material, which makes its sealing performance with the pilot valve needle and the outlet better.

[0038] The valve stem adopts a pilot valve needle, which can be used in high-pressure refrigerant environments.

[0039] In this patent, equal-diameter springs are arranged between the moving iron core and the stationary iron core, as well as on the piston assembly, which can prevent the spring from falling out and simplifies the process. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0041] Figure 1 It is an exploded three-dimensional structural schematic diagram of an embodiment of the high-pressure pilot solenoid valve of the utility model;

[0042] Figure 2 It is a schematic cross-sectional structure diagram of an embodiment of the high-pressure pilot solenoid valve of the utility model in a power-off state;

[0043] Figure 3 It is a cross-sectional structural schematic diagram of an embodiment of the high-pressure pilot solenoid valve of the utility model in a power-on state;

[0044] Figure 4 It is a cross-sectional structural schematic diagram of another embodiment of the high-pressure pilot solenoid valve of the utility model in a power-off state;

[0045] Figure 5 It is a partially enlarged schematic diagram of an example of the piston assembly of the utility model;

[0046] Figure 6 It is a partially enlarged schematic diagram of another example of the piston assembly of the utility model.

[0047] Among them, 1-valve body, 2-valve stem, 3-piston assembly, 4-piston spring, 5-sleeve, 6-moving iron core, 7-static iron core, 11-inlet, 12-fluid chamber, 13-outlet, 14-pilot chamber, 15-lubricating ring, 101-large valve seat, 102-small valve seat, 103-convex ring, 104-first sealing ring, 105-second sealing ring, 31-piston seat, 32-piston valve, 311-balancing hole, 312-spring groove, 313-side wall, 314-stop protrusion, 321-piston valve port, 41-contact surface, 42-first surface, 61-pilot spring. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be understood that the terms "upper", "lower", "inner", "outer", "one end", "the other end", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In the description of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0050] In the description of the present invention, unless otherwise clearly specified and limited, the terms "provided with", "equipped with", "connected", "installed with", "set", "opened", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0052] See also Figure 1-Figure 6 ,like Figure 1-6 As shown, a high-pressure pilot solenoid valve of the utility model comprises a valve body 1, a valve stem 2 and a piston assembly 3;

[0053] The valve body 1 is provided with an inlet 11, an outlet 13 and an inner cavity, and the inlet 11 and the outlet 13 are both connected to the inner cavity;

[0054] The piston assembly 3 is accommodated in the inner cavity of the valve body 1, and the piston assembly 3 is configured to be able to move toward the outlet 13 or move in a direction away from the outlet 13;

[0055] The inner cavity is divided into a fluid cavity 12 and a pilot cavity 14 by the piston assembly 3. The inlet 11 and the outlet 13 are both located on the same side of the piston seat 31. The inlet 11 and the outlet 13 are both connected to the fluid cavity 12.

[0056] The piston assembly 3 is provided with a through piston valve port 321, the piston valve port 321 is connected to the pilot cavity 14, and the piston valve port 321 corresponds to the outlet 13;

[0057] A piston spring 4 is provided between the piston assembly 3 and the inner wall of the fluid chamber 12;

[0058] At least one end of the valve stem 2 extends into the pilot cavity 14 , and the valve stem 2 is configured to be able to move toward the piston valve port 321 and seal against the piston valve port 321 or move away from the piston valve port 321 and move away from the piston valve port 321 .

[0059] Preferably, the piston spring 4 is a spring of equal diameter.

[0060] Preferably, the piston assembly 3 includes a piston seat 31 and a piston valve 32, and the piston valve 32 is arranged on the piston seat 31;

[0061] The inner cavity is divided into a fluid cavity 12 and a pilot cavity 14 by a piston seat 31;

[0062] The piston valve 32 is provided with a through piston valve port 321 . The piston valve port 321 passes through the piston seat 31 and is in communication with the pilot cavity 14 . The piston valve port 321 corresponds to the outlet 13 .

[0063] Of course, the piston valve 32 can be detachably or non-detachably arranged on the piston seat 31 .

[0064] In the example, the inlet 11 and the outlet 13 are both located on the same side of the piston assembly 3. Figure 2-4 As shown, the inlet 11 and the outlet 13 are both located on the same side of the piston seat 31 .

[0065] Preferably, the valve stem 2 is a pilot valve needle, such as Figure 1-4 In the example, the end of the pilot valve needle close to the piston valve is the sealing end. In the example, the sealing end is a conical sealing head.

[0066] In a preferred embodiment, Figure 2-4 As shown, a balancing hole 311 is opened on the piston assembly 3 , one end of the balancing hole 311 is connected to the fluid chamber 12 , and the other end is connected to the pilot chamber 14 .

[0067] Further preferably, the inner diameter of the piston valve port 321 is larger than the inner diameter of the balance hole 311. More preferably, the inner diameter of the piston valve port 321 close to the pilot cavity is larger than the inner diameter of the balance hole 311 close to the fluid cavity.

[0068] In the example, the balancing hole 311 is opened on the piston seat 31 .

[0069] Preferably, one end of the piston spring 4 contacts the outer edge of the outlet 13, and the other end of the piston spring 4 contacts the piston assembly 3. In the example, a receiving groove is provided on the inner wall of the fluid chamber, the receiving groove is arranged around the outer edge of the outlet 13, and one end of the piston spring 4 is received in the receiving groove.

[0070] Preferably, Figure 2-6As shown, a spring groove 312 is provided on one side of the piston assembly 3 close to the outlet 13, the opening of the spring groove 312 is arranged facing the outlet 13, and the other end of the piston spring 4 is accommodated in the spring groove 312. Specifically, the other end of the piston spring 4 includes a contact surface 41 and a first surface 42, the spring groove 312 includes a side wall 313, and the contact surface 41 contacts the side wall 313. Further preferably, the contact surface 41 contacts the side wall 313. Further preferably, the spring groove 312 is arranged on one side of the piston seat 31 close to the outlet.

[0071] Further preferably, Figure 2-6 As shown, the side wall of the spring slot 312 is also provided with a stop protrusion 314, and the first surface 42 of the piston spring 4 contacts the stop protrusion 314. In the example, the stop protrusion 314 is provided at one end of the side wall 313 away from the bottom of the spring slot.

[0072] Preferably, the piston valve opening 321 is trumpet-shaped, and the inner diameter of the piston valve opening 321 gradually increases toward the outlet 13 .

[0073] In a preferred embodiment, Figure 2-4 As shown, a lubrication groove is provided on the inner wall of the inner cavity of the valve body or the piston assembly 3, and a lubrication ring 15 is placed in the lubrication groove, and the lubrication ring is configured to support the piston assembly to move smoothly and smoothly. In the example, the lubrication groove is provided on the inner wall of the inner cavity of the valve body. Further, the lubrication ring is configured to support the piston seat 31 to move smoothly and steadily.

[0074] In a preferred embodiment, Figure 1-4 As shown, it also includes a sleeve 5 , which is fixed on the valve body 1 , and one end of the valve stem 2 away from the piston valve port 321 is accommodated in the sleeve 5 .

[0075] In the example, the sleeve 5 is sealingly mounted on the valve body 1. Of course, the present invention is not limited thereto.

[0076] Preferably, it also includes a moving iron core 6, which is accommodated in the sleeve 5, and the end of the valve stem 2 away from the piston assembly is fixed on the moving iron core, and the moving iron core 6 is configured to move toward the direction close to the piston assembly or move toward the direction away from the piston assembly.

[0077] More preferably, it further comprises a static iron core 7 , which is fixed in the sleeve 5 , and a pilot spring 61 is arranged between the static iron core 7 and the moving iron core; when power is turned on, the moving iron core 6 moves toward the static iron core 7 .

[0078] Preferably, the pilot spring 61 is a spring of equal diameter.

[0079] An example, such as Figure 1-3As shown, the moving iron core is located on the side of the stationary iron core away from the valve body, a pilot spring 61 is arranged between the moving iron core and the stationary iron core, and the valve stem passes through the stationary iron core and extends into the valve body. In the example, the moving iron core is configured to move toward the direction close to the piston assembly and seal on the piston valve port 321 when power is turned on, and move toward the direction away from the piston assembly and move away from the piston valve port 321 after power is turned off. In the example, the pilot spring 61 is sleeved on the pilot valve needle, that is, the solenoid valve is in a normally open mode.

[0080] An example, such as Figure 4 As shown, the moving iron core is located on the side of the stationary iron core close to the valve body, and a pilot spring is arranged between the moving iron core and the stationary iron core. In the example, the moving iron core is configured to move toward the direction close to the piston assembly and seal on the piston valve port 321 when the power is off, and move toward the direction away from the piston assembly and move away from the piston valve port 321 when the power is on, that is, the solenoid valve is in a normally closed mode.

[0081] In a preferred embodiment, the piston valve is detachably connected to the piston seat.

[0082] Further preferably, the piston valve 32 is made of plastic, metal, etc. Of course, the present invention is not limited thereto, and the piston valve can also be made of other materials. More preferably, the piston valve is made of plastic.

[0083] Preferably, the piston valve is a T-shaped structure, and a connecting portion is provided on the piston valve, and the connecting portion can be detachably mounted on the piston seat 31 .

[0084] In the example, the side of the piston valve close to the outlet is the control surface. When the valve is closed, the control surface is sealed against the outlet.

[0085] In a preferred embodiment, Figure 2-4 As shown, the valve body 1 is of split design, and the valve body 1 includes a large valve seat 101 and a small valve seat 102, and the small valve seat 102 is detachably mounted on the large valve seat 101. In the example, the small valve seat 102 is screwed on the opening of the large valve seat 101.

[0086] A convex ring 103 is radially wound around the surface of the valve body 1. In the example, the convex ring 103 is integrally connected to the valve body 1. In the example, the direction of the convex ring 103 is consistent with the direction of the outlet 13. In the example, the convex ring 103 is wound around the large valve seat 101.

[0087] Preferably, Figure 2-4As shown, the valve body 1 includes a first body, a second body and a third body in sequence along the axis. In the example, the outlet is opened at one end of the first body. Further preferably, the outer diameter of the first body is smaller than the outer diameter of the second body. Further preferably, the second body is located between the first body and the convex ring, and the third body is located on the side of the convex ring 103 away from the outlet. In the example, the first body, the second body and the third body are connected as a whole. Preferably, the surface of the second body is a smooth surface. Preferably, the surface of the third body is provided with an external thread.

[0088] The surface of the valve body 1 is sleeved with a first sealing ring 104. Figure 2-4 As shown, the first sealing ring 104 is sleeved on the side of the convex ring close to the opening. In the example, the inner diameter of the first sealing ring 104 is smaller than the outer diameter of the large valve seat 101, and the sealing ring is tightly sleeved on the surface of the large valve seat 101. In the example, the first sealing ring is a sealing ring for leaking out of the large valve seat. In the example, the first sealing ring 104 is sleeved on the second body.

[0089] Preferably, the surface of the valve body 1 is also sleeved with a second sealing ring 105, and the second sealing ring 105 is located at one end of the surface of the valve body 1 close to the outlet. In the example, the second sealing ring 105 is sleeved on the first body. In the example, the second sealing ring is an inner leakage sealing ring. In one example, a sealing groove is provided on the first body, and the second sealing ring 105 is accommodated in the sealing groove. In one example, the outer diameter of the first body is smaller than the outer diameter of the second body, and the second sealing ring 105 is sleeved on the first body and conflicts with the second body.

[0090] like Figure 1-3 In the embodiment shown, the closing and opening principles of the electromagnetic valve of the utility model are as follows:

[0091] When the solenoid valve is not energized, it is in the normally open state. At this time, the inlet and outlet are connected, and the fluid enters the fluid cavity from the inlet. Part of the fluid is discharged directly from the outlet, and part of the fluid enters the pilot cavity through the balance hole, and then is discharged from the pilot cavity through the piston valve port to the outlet. After power is turned on, the moving iron core moves downward and adsorbs on the static iron core, driving the pilot valve needle to move downward synchronously, and the sealing end of the pilot valve needle is sealed at the piston valve port. At this time, the fluid flow rate at the outlet is instantly accelerated, and the pressure at the outlet is reduced. The pressure in the pilot cavity remains consistent with the inlet, and the pressure difference between the pilot cavity and the outlet drives the piston assembly to move downward, and the piston valve is sealed on the outlet to close the valve.

[0092] After power failure, the moving iron core no longer generates magnetism and returns to its original position under the rebound force of the pilot spring. At the same time, the pilot valve needle also moves upward. The pilot valve needle no longer seals the piston valve port, and the fluid in the pilot cavity is quickly released. The pressure in the pilot cavity is released faster than the pressure released through the balancing hole at the inlet, resulting in a pressure difference between the inlet and the pilot cavity. At the same time, the piston valve moves away from the outlet under the rebound action of the piston spring and reopens the valve.

[0093] like Figure 4 In the embodiment shown, the closing and opening principles of the electromagnetic valve of the utility model are as follows:

[0094] When the solenoid valve is not powered on, it is in a normally closed state. At this time, the pilot valve needle is sealed on the piston valve port, the piston valve is sealed on the outlet, and the solenoid valve is in a closed state. After power is turned on, the moving iron core moves upward and adsorbs on the static iron core, and the pilot valve needle also moves upward synchronously. The pilot valve needle moves away from the piston valve port, and the fluid in the pilot cavity is quickly released. The pressure release speed in the pilot cavity is faster than the speed released through the balance hole at the inlet, resulting in a pressure difference between the inlet and the pilot cavity. At the same time, the piston valve moves away from the outlet under the rebound action of the piston spring, and the solenoid valve opens.

[0095] After the solenoid valve is opened, the fluid enters the fluid cavity from the inlet, part of the fluid is discharged directly from the outlet, and part of the fluid enters the pilot cavity through the balance hole, and then is discharged from the pilot cavity through the piston valve port to the outlet.

[0096] After power failure, the moving iron core no longer generates magnetism, and under the action of the rebound force of the pilot spring, the moving iron core returns to the direction of the piston assembly, driving the pilot valve needle to move downward synchronously. The sealing end of the pilot valve needle is sealed at the piston valve port. At this time, the fluid flow rate at the outlet is instantly accelerated, and the pressure at the outlet is reduced. The pressure in the pilot cavity remains consistent with the inlet. The pressure difference between the pilot cavity and the outlet drives the piston assembly to move downward, the piston valve is sealed on the outlet, and the solenoid valve is closed.

[0097] All of the above components or all features of all components can be freely combined without conflict. In addition, changes, modifications and variations in the component structure are also within the scope of protection of this patent.

[0098] In the description of this specification, the description with reference to the terms "preferred embodiment", "example", or "an example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0099] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A high pressure pilot solenoid valve, characterized in that: It comprises a valve body (1), a valve stem (2) and a piston assembly (3); The valve body (1) is provided with an inlet (11), an outlet (13) and an inner cavity, and the inlet (11) and the outlet (13) are both connected to the inner cavity; The piston assembly (3) is accommodated in the inner cavity of the valve body (1), and the piston assembly (3) is configured to be able to move toward the outlet (13) or move in a direction away from the outlet (13); The inner cavity is divided into a fluid cavity (12) and a pilot cavity (14) by a piston assembly (3), and the inlet (11) and the outlet (13) are both connected to the fluid cavity (12); The piston assembly (3) is provided with a through piston valve port (321), the piston valve port (321) is connected to the pilot cavity (14), and the piston valve port (321) corresponds to the outlet (13); A piston spring (4) is arranged between the piston assembly (3) and the inner wall of the fluid chamber (12); At least one end of the valve stem (2) extends into the pilot cavity (14), and the valve stem (2) is configured to be able to move toward the piston valve port (321) and seal against the piston valve port (321) or to move in a direction away from the piston valve port (321) and move away from the piston valve port (321).

2. The high pressure pilot solenoid valve according to claim 1, characterized in that: The piston assembly (3) comprises a piston seat (31) and a piston valve (32), wherein the piston valve (32) is arranged on the piston seat (31); The inner cavity is divided into a fluid cavity (12) and a pilot cavity (14) by a piston seat (31); A through piston valve port (321) is provided on the piston valve (32), and the piston valve port (321) is communicated with the pilot cavity (14).

3. The high pressure pilot solenoid valve according to any one of claims 1 or 2, characterized in that: A balancing hole (311) is provided on the piston assembly (3); one end of the balancing hole (311) is connected to the fluid chamber (12), and the other end of the balancing hole (311) is connected to the pilot chamber (14).

4. The high pressure pilot solenoid valve according to claim 3, characterized in that: The inner diameter of the piston valve port (321) is larger than the inner diameter of the balancing hole (311); and / or The valve stem (2) is the pilot valve needle.

5. The high pressure pilot solenoid valve according to claim 1, characterized in that: It also includes a sleeve (5), the sleeve (5) is fixed on the valve body (1), and one end of the valve stem (2) away from the piston valve port (321) is accommodated in the sleeve (5); and / or The valve stem (2) further comprises a moving iron core (6), which is accommodated in the sleeve (5). The end of the valve stem (2) away from the piston assembly is fixed on the moving iron core. The moving iron core (6) is configured to move toward a direction close to the piston assembly or toward a direction away from the piston assembly.

6. The high pressure pilot solenoid valve according to claim 5, characterized in that: It also includes a static iron core (7), which is fixed in the sleeve (5), and a pilot spring (61) is arranged between the static iron core (7) and the moving iron core.

7. The high pressure pilot solenoid valve according to claim 6, characterized in that: The pilot spring (61) is a spring of equal diameter.

8. The high pressure pilot solenoid valve according to claim 2, characterized in that: The piston valve (32) is detachably connected to the piston seat (31); and / or The piston valve (32) is made of plastic or metal.

9. The high pressure pilot solenoid valve according to claim 1, characterized in that: A lubrication groove is provided on the inner wall of the inner cavity of the valve body or on the piston assembly (3), a lubrication ring (15) is arranged in the lubrication groove, and the lubrication ring is configured to lubricate the movement of the piston assembly; and / or The piston spring (4) is a spring of equal diameter.

10. The high pressure pilot solenoid valve according to claim 1, characterized in that: A convex ring (103) is radially arranged around the surface of the valve body (1), a first sealing ring (104) is sleeved on the surface of the valve body (1), and the first sealing ring (104) is sleeved on a side of the convex ring close to the opening; and / or A second sealing ring (105) is sleeved on the surface of the valve body (1), and the second sealing ring (105) is located at one end of the surface of the valve body (1) close to the outlet.

11. The high pressure pilot solenoid valve according to claim 1 or 2, characterized in that: A spring groove (312) is provided on one side of the piston assembly (3) close to the outlet (13), the opening of the spring groove (312) is arranged facing the outlet (13), and the other end of the piston spring (4) is accommodated in the spring groove (312).

12. The high pressure pilot solenoid valve according to claim 11, characterized in that: The other end of the piston spring (4) includes a contact surface (41) and a first surface (42), the spring groove (312) includes a side wall (313), and the contact surface (41) is in contact with the side wall (313); The side wall of the spring groove (312) is also provided with a stop protrusion (314), and the first surface (42) of the piston spring (4) is in contact with the stop protrusion (314).

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