Pilot-controlled electromagnetic valve

Abstract

The invention relates to the technical field of hydraulic valves, in particular to a pilot-controlled electromagnetic valve. The pilot-controlled electromagnetic valve comprises a flux sleeve, a coil, a valve sleeve, an armature assembly, a main valve element, a pilot valve element and an elastic centering assembly, a movable iron piece in the armature assembly is arranged in the flux sleeve in a penetrating mode and can move in the axial direction relative to the flux sleeve along with electromagnetic force generated by the coil, and a first pressure oil cavity and a second pressure oil cavity are formed between the valve sleeve and the main valve element. The pressure difference between the first pressure oil cavity and the second pressure oil cavity can push the main valve element to move, the movable iron piece can adjust the pressure difference between the first pressure oil cavity and the second pressure oil cavity when driving the pilot valve element to move relative to the main valve element, and the elastic centering assembly is arranged on the main valve element. The elastic centering assembly always has the trend of preventing the main valve element from moving relative to the valve sleeve. When no pressure difference exists between the first pressure oil cavity and the second pressure oil cavity, the pilot-controlled electromagnetic valve can ensure that the main valve element is in the middle position, and the reliability of the pilot-controlled electromagnetic valve is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic valves, and in particular to a pilot-controlled solenoid valve. Background Art

[0002] The hydraulic threaded cartridge solenoid valve is the main component of the hydraulic system reversing control. It has the advantages of easy installation and small size. In addition, the pilot control acts as a power amplifier to control the power stage main valve core through the pilot valve core with a small driving force, which can achieve rapid switching of large flow rates.

[0003] The existing pilot-controlled solenoid valve usually sets a first pressure oil chamber and a second pressure oil chamber between the valve sleeve and the main valve core, and adjusts the pressure difference between the first pressure oil chamber and the second pressure oil chamber by moving the pilot valve core, and then drives the main valve core to move by the pressure difference between the first pressure oil chamber and the second pressure oil chamber, so as to realize the flow control of the pilot-controlled solenoid valve. However, when the pilot-controlled solenoid valve is in the initial state, that is, when there is no pressure difference between the first pressure oil chamber and the second pressure oil chamber, the relative position of the main valve core is easily offset, and the main valve core cannot be ensured to be in the middle position, which greatly reduces the reliability of the pilot-controlled solenoid valve.

[0004] Therefore, there is an urgent need for a pilot-controlled solenoid valve to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a pilot-controlled solenoid valve, which can ensure that the main valve core is in the middle position when there is no pressure difference between the first pressure oil chamber and the second pressure oil chamber of the pilot-controlled solenoid valve, thereby ensuring the reliability of the pilot-controlled solenoid valve.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A pilot-controlled solenoid valve, comprising:

[0008] Magnetic sleeve;

[0009] A coil, wherein the coil is sleeved on the outer circumference of the magnetic conductive sleeve;

[0010] A valve sleeve, the valve sleeve is connected to the end of the magnetic sleeve, and the valve sleeve is provided with a plurality of oil ports at intervals;

[0011] An armature assembly, the armature assembly comprising a movable iron piece, the movable iron piece being inserted into the magnetic conductive sleeve and being able to move relative to the magnetic conductive sleeve along the axial direction of the magnetic conductive sleeve with the electromagnetic force generated by the coil;

[0012] A main valve core is inserted into the valve sleeve and can move relative to the valve sleeve along the axial direction of the valve sleeve to connect or block the plurality of oil ports. The valve sleeve and the main valve core cooperate to form a first pressure oil chamber and a second pressure oil chamber. The pressure difference between the first pressure oil chamber and the second pressure oil chamber can drive the main valve core to move.

[0013] a pilot valve core, which is inserted into the main valve core, the pilot valve core is fixedly connected to the movable iron member, and the movable iron member drives the pilot valve core to move relative to the main valve core to adjust the pressure difference between the first pressure oil chamber and the second pressure oil chamber; and

[0014] The elastic centering component is arranged on the main valve core, and the elastic centering component is configured to always have a tendency to hinder the main valve core from moving relative to the valve sleeve.

[0015] As an optional solution, a first abutment portion and a second abutment portion are provided on the outer peripheral wall of the main valve core, and the first abutment portion and the second abutment portion are arranged at intervals along the axial direction of the main valve core;

[0016] The armature assembly also includes a stopper iron fixedly inserted into the magnetic conductive sleeve;

[0017] The elastic centering component includes a first limiting ring, a second limiting ring and a centering spring, the first limiting ring and the second limiting ring are both sleeved on the outer circumference of the main valve core, the first limiting ring and the second limiting ring are arranged at intervals along the axial direction of the main valve core, the side of the first limiting ring away from the second limiting ring can abut against the stop iron, and the side of the first limiting ring away from the second limiting ring abuts against the first abutting portion, the side of the second limiting ring away from the first limiting ring can abut against the valve sleeve, and the side of the second limiting ring away from the first limiting ring abuts against the second abutting portion, the centering spring is sleeved on the outer circumference of the main valve core, the first end of the centering spring abuts against the first limiting ring, and the second end of the centering spring abuts against the second limiting ring.

[0018] As an optional solution, the first abutting portion is an abutting protrusion fixedly sleeved on the outer peripheral wall of the main valve core, or the first abutting portion is a positioning shoulder arranged on the outer peripheral wall of the main valve core;

[0019] The second abutting portion is an abutting protrusion fixedly sleeved on the outer peripheral wall of the main valve core, or the second abutting portion is a positioning shoulder arranged on the outer peripheral wall of the main valve core.

[0020] As an optional solution, the moving iron member includes:

[0021] A moving iron, wherein the moving iron and the stop iron are arranged at intervals along the axial direction of the main valve core, and the stop iron can abut against the moving iron to limit the extreme position of the moving iron moving relative to the magnetic sleeve toward the valve sleeve; and

[0022] A connecting rod, wherein the first end of the connecting rod is connected to the inner cavity of the moving iron, the second end of the connecting rod is penetrated into the inner cavity of the stop iron, and the second end of the connecting rod is fixedly connected to the pilot valve core.

[0023] As an optional solution, the pilot-controlled solenoid valve further includes:

[0024] The elastic return component is configured to always have a tendency to hinder the movement of the pilot valve core.

[0025] As an optional solution, a third abutment portion is provided on the outer peripheral wall of the connecting rod, and a fourth abutment portion is provided on the outer peripheral wall of the pilot valve core or on the outer peripheral wall of the connecting rod, and the third abutment portion and the fourth abutment portion are arranged at intervals along the axial direction of the pilot valve core;

[0026] The elastic reset assembly includes a third limit ring, a fourth limit ring and a reset spring, the third limit ring and the fourth limit ring are arranged at intervals along the axial direction of the pilot valve core, the third limit ring is sleeved on the outer circumference of the connecting rod, the side of the third limit ring away from the fourth limit ring can abut against the stop iron, and the side of the third limit ring away from the fourth limit ring abuts against the third abutting portion, the fourth limit ring is sleeved on the outer circumference of the pilot valve core or the connecting rod, the side of the fourth limit ring away from the third limit ring can abut against the stop iron, and the side of the fourth limit ring away from the third limit ring abuts against the fourth abutting portion, the first end of the reset spring abuts against the third limit ring, and the second end of the reset spring abuts against the fourth limit ring.

[0027] As an optional solution, the valve sleeve is provided with a first oil port, a second oil port, a third oil port, a fourth oil port and a fifth oil port in sequence and spaced apart along its axial direction;

[0028] The main valve core is provided with a first oil delivery hole communicating with the first pressure oil chamber, and the main valve core is also provided with a second oil delivery hole communicating with the second pressure oil chamber;

[0029] The pilot valve core is provided with a pilot oil circuit, which connects or blocks the first pressure oil chamber when the pilot valve core moves relative to the main valve core, and connects or blocks the second pressure oil chamber when the pilot valve core moves relative to the main valve core.

[0030] As an optional solution, the first oil port and the fifth oil port are oil inlet ports, the second oil port and the fourth oil port are working oil ports, and the third oil port is an oil unloading port;

[0031] An annular cavity is provided between the main valve core and the pilot valve core, the annular cavity can be connected to the first pressure oil cavity or the second pressure oil cavity, and shoulders at both ends of the annular cavity are used to seal the first oil delivery hole and the second oil delivery hole respectively;

[0032] The pilot valve core is provided with a first channel and a second channel at two ends along the axial direction thereof, respectively, and the first channel, the second channel and the annular cavity are connected to form the pilot oil circuit;

[0033] A valve hole communicating with the first pressure oil chamber and the second pressure oil chamber is formed in the axial direction of the side wall of the main valve core, and the valve hole is communicated with the oil inlet.

[0034] As an optional solution, the first channel, the annular cavity and the oil unloading port are connected to form a first pressure relief flow channel;

[0035] An oil inlet hole connected to the inner cavity of the magnetic sleeve is opened at the end of the pilot valve core along its radial direction, and the oil inlet hole is connected to the second channel. The oil inlet hole, the second channel, the annular cavity and the oil unloading port are connected to form a second pressure relief channel.

[0036] As an optional solution, the valve sleeve and the main valve core cooperate to form a third annular cavity and a fourth annular cavity, a connecting boss is provided between the third annular cavity and the fourth annular cavity, and a connecting hole for connecting the third oil port and the pilot oil circuit is provided on the connecting boss;

[0037] When the main valve core moves, the third annular cavity can connect the second oil port to or block the first oil port, the third annular cavity can connect the second oil port to or block the third oil port, the fourth annular cavity can connect the fourth oil port to or block the third oil port, and the fourth annular cavity can connect the fourth oil port to or block the fifth oil port.

[0038] Beneficial effects of the present invention:

[0039] The present invention provides a pilot-controlled solenoid valve, which is implemented by arranging a coil sleeve on the outer periphery of a magnetic sleeve, connecting the valve sleeve to the end of the magnetic sleeve, and a moving iron piece is inserted into the magnetic sleeve and can move relative to the magnetic sleeve along the axial direction of the magnetic sleeve with the electromagnetic force generated by the coil. The main valve core is inserted into the valve sleeve, and the pilot valve core is inserted into the main valve core. The valve sleeve and the main valve core cooperate to form a first pressure oil chamber and a second pressure oil chamber. When the moving iron piece moves to drive the pilot valve core to move relative to the main valve core, the pressure difference between the first pressure oil chamber and the second pressure oil chamber can be adjusted. The pressure difference between the first pressure oil chamber and the second pressure oil chamber can drive the main valve core to move, so as to connect or block multiple oil ports on the valve sleeve, thereby realizing flow control of the pilot-controlled solenoid valve. In addition, the pilot-controlled solenoid valve is provided with an elastic centering component on the main valve core, and the elastic centering component always has a tendency to hinder the movement of the main valve core relative to the valve sleeve, so that the pilot-controlled solenoid valve can ensure that the main valve core is in the middle position in the initial state, that is, when there is no pressure difference between the first pressure oil chamber and the second pressure oil chamber, thereby ensuring the reliability of the pilot-controlled solenoid valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a structural cross-sectional view of a pilot-controlled solenoid valve provided in Embodiment 1 of the present invention;

[0041] Figure 2 is a first partial structural sectional view of a pilot-controlled solenoid valve provided in the first embodiment of the present invention;

[0042] Figure 3 is a second partial structural sectional view of the pilot-controlled solenoid valve provided in the first embodiment of the present invention;

[0043] Figure 4 is a structural cross-sectional view of a pilot-controlled solenoid valve provided in Embodiment 2 of the present invention;

[0044] Figure 5 It is a partial structural cross-sectional view of a pilot-controlled solenoid valve provided in the second embodiment of the present invention.

[0045] In the figure:

[0046] 1. Magnetic guide sleeve; 11. Magnetic isolation tube; 12. Tail screw; 13. Front screw; 14. Locking nut;

[0047] 2. Coil; 21. First coil; 22. Second coil; 23. Gasket;

[0048] 3. Valve sleeve; 31. First oil port; 32. Second oil port; 33. Third oil port; 34. Fourth oil port; 35. Fifth oil port; 36. Step surface; 37. Shaft seal; 38. Snap ring; 39. Positioning boss; 391. Sealing snap ring; 392. Sealing ring;

[0049] 4. armature assembly; 41. movable iron piece; 411. movable iron; 412. connecting rod; 4121. third abutting portion; 413. cylindrical pin; 42. stop iron;

[0050] 5. Main valve core; 51. First abutment portion; 52. Second abutment portion; 53. First oil delivery hole; 54. Second oil delivery hole; 55. Valve hole; 56. Connecting boss; 561. Connecting hole; 57. Oil unloading hole; 58. First blind hole; 581. First connecting hole; 59. Second blind hole; 591. Second connecting hole;

[0051] 6. pilot valve core; 61. fourth abutment portion; 63. first passage; 64. second passage; 65. oil inlet hole; 66. first shoulder; 67. second shoulder; 6a. oil hole; 611. oil passage;

[0052] 7. Elastic centering assembly; 71. First limiting ring; 72. Second limiting ring; 73. Centering spring;

[0053] 8. Elastic reset assembly; 81. Third limiting ring; 82. Fourth limiting ring; 83. Reset spring;

[0054] p1, first pressure oil chamber; p2, second pressure oil chamber; b, annular chamber; b1, first annular chamber; b2, second annular chamber; b4, third annular chamber; b5, fourth annular chamber. DETAILED DESCRIPTION

[0055] In order to make the technical problem solved by the present invention, the technical solution adopted and the technical effect achieved more clearly, the technical solution of the present invention is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0056] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection 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.

[0057] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0058] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0059] Embodiment 1

[0060] like Figure 1 and Figure 2 As shown, this embodiment provides a pilot-controlled solenoid valve, which includes a magnetic sleeve 1, a coil 2, a valve sleeve 3, an armature assembly 4, a main valve core 5 and a pilot valve core 6, wherein the coil 2 is sleeved on the outer periphery of the magnetic sleeve 1, the valve sleeve 3 is connected to the right end of the magnetic sleeve 1, and a plurality of oil ports are spaced apart on the valve sleeve 3. The armature assembly 4 includes a movable iron member 41, which is inserted into the magnetic sleeve 1 and can move relative to the magnetic sleeve 1 along the axial direction (left and right direction in the figure) of the magnetic sleeve 1 with the electromagnetic force generated by the coil 2. The main valve core 5 is inserted into the valve sleeve 3. The valve sleeve 3 is provided with a first pressure oil chamber p1 and a second pressure oil chamber p2, and the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2 can drive the main valve core 5 to move. The pilot valve core 6 is arranged in the main valve core 5, and the pilot valve core 6 is fixedly connected to the movable iron member 41. When the movable iron member 41 drives the pilot valve core 6 to move relative to the main valve core 5, the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2 can be adjusted. The pilot-controlled solenoid valve provided in this embodiment can adjust the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2 when the movable iron member 41 moves and drives the pilot valve core 6 to move relative to the main valve core 5. The pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2 can drive the main valve core 5 to move, so as to conduct or block multiple oil ports on the valve sleeve 3, thereby realizing flow control of the pilot-controlled solenoid valve.

[0061] In this embodiment, if Figure 1 and Figure 3 As shown, the movable iron member 41 includes a movable iron 411 and a connecting rod 412, wherein the first end of the connecting rod 412 (i.e., the left end of the connecting rod 412) is connected to the inner cavity of the movable iron 411, and the second end of the connecting rod 412 (i.e., the right end of the connecting rod 412) is fixedly connected to the pilot valve core 6. Optionally, the movable iron member 41 further includes a cylindrical pin 413, and the first end of the connecting rod 412 is connected to the inner cavity of the movable iron 411 through the cylindrical pin 413.

[0062] In this embodiment, if Figure 1 and Figure 3 As shown, the armature assembly 4 also includes a stopper 42, which is fixedly inserted into the magnetic sleeve 1, and the stopper 42 and the moving iron 411 are arranged at intervals along the axial direction (left and right direction in the figure) of the main valve core 5, and the second end of the connecting rod 412 is inserted into the inner cavity of the stopper 42 and fixedly connected to the pilot valve core 6, and the stopper 42 can abut against the moving iron 411 to limit the limit position of the moving iron 411 moving relative to the magnetic sleeve 1 toward the valve sleeve 3 (i.e., to the right). Optionally, in this embodiment, a limiting groove is provided at the left end of the stopper 42, and the limiting groove can abut against the right end of the moving iron 411, thereby limiting the limit position of the moving iron 411 moving relative to the magnetic sleeve 1 to the right.

[0063] like Figure 1 and Figure 3 As shown, the magnetic sleeve 1 includes a magnetic isolation tube 11, a tail ear 12, a front ear 13 and a locking nut 14, wherein the outer periphery of the magnetic isolation tube 11 is provided with a coil 2, the left end of the magnetic isolation tube 11 is provided with a tail ear 12, the right end of the magnetic isolation tube 11 is provided with a front ear 13, and the left end of the tail ear 12 is threadedly connected with a locking nut 14, and the locking nut 14 is used to press the coil 2 against the left end of the front ear 13, thereby preventing the coil 2 from moving in the axial direction, and achieving the fixation of the coil 2 on the outer periphery of the magnetic sleeve 1. Optionally, in this embodiment, the right end of the tail ear 12 can abut against the left end of the moving iron 411, thereby limiting the limit position of the moving iron 411 moving in the direction away from the valve sleeve 3 (i.e., to the left). Optionally, in this embodiment, the right end of the tail ear 12 is provided with an abutting groove, and the abutting groove can abut against the left end of the moving iron 411, thereby limiting the limit position of the moving iron 411 moving to the left relative to the magnetic sleeve 1.

[0064] Alternatively, if Figure 1 and Figure 3As shown, the coil 2 includes a first coil 21, a second coil 22 and a gasket 23, wherein the first coil 21 and the second coil 22 are arranged at intervals along the axial direction (left and right direction in the figure) of the magnetic isolation tube 11, and the gasket 23 is sandwiched between the first coil 21 and the second coil 22, thereby isolating the first coil 21 and the second coil 22. It should be noted that in this embodiment, when both the first coil 21 and the second coil 22 are not energized, no electromagnetic force is generated at this time, and the pilot valve core 6 is in the middle position; when the first coil 21 located on the right side is energized, the moving iron 411 drives the pilot valve core 6 to move to the right under the action of the magnetic field force; when the first coil 21 located on the right side loses power, the pilot valve core 6 can move to the left and reset to the middle position; when the second coil 22 located on the left side is energized, the moving iron 411 drives the pilot valve core 6 to move to the left under the action of the magnetic field force; when the second coil 22 located on the left side loses power, the pilot valve core 6 can move to the right and reset to the middle position.

[0065] The existing pilot-controlled solenoid valve adjusts the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2 by moving the pilot valve core 6, and then drives the main valve core 5 to move by the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, so as to realize the flow control of the pilot-controlled solenoid valve. However, when the pilot-controlled solenoid valve is in the initial state, that is, when there is no pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, the relative position of the main valve core 5 is easily offset, and the main valve core 5 cannot be ensured to be in the middle position, which greatly reduces the reliability of the pilot-controlled solenoid valve.

[0066] In order to solve the above problems, Figure 1 and Figure 2 As shown, the pilot-controlled solenoid valve provided in this embodiment further includes an elastic centering component 7, which is arranged on the main valve core 5, and is configured to always have a tendency to hinder the main valve core 5 from moving relative to the valve sleeve 3. By arranging the elastic centering component 7 on the main valve core 5, and the elastic centering component 7 always having a tendency to hinder the main valve core 5 from moving relative to the valve sleeve 3, the pilot-controlled solenoid valve can ensure that the main valve core 5 is in the middle position in the initial state, that is, when there is no pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, thereby ensuring the reliability of the pilot-controlled solenoid valve.

[0067] Optionally, in this embodiment, if Figure 1 and Figure 2As shown, a first abutment portion 51 and a second abutment portion 52 are provided on the outer peripheral wall of the main valve core 5, and the first abutment portion 51 and the second abutment portion 52 are arranged at intervals along the axial direction of the main valve core 5. The elastic centering component 7 includes a first limiting ring 71, a second limiting ring 72 and a centering spring 73. The first limiting ring 71 and the second limiting ring 72 are both sleeved on the outer periphery of the main valve core 5, and the first limiting ring 71 and the second limiting ring 72 are arranged at intervals along the axial direction of the main valve core 5. The side of the first limiting ring 71 away from the second limiting ring 72 (i.e., the left side of the first limiting ring 71) can abut against the stop iron 42. , and the side of the first limiting ring 71 away from the second limiting ring 72 abuts against the first abutting portion 51, the side of the second limiting ring 72 away from the first limiting ring 71 (i.e. the right side of the second limiting ring 72) can abut against the valve sleeve 3, and the side of the second limiting ring 72 away from the first limiting ring 71 abuts against the second abutting portion 52, the centering spring 73 is sleeved on the outer periphery of the main valve core 5, the first end of the centering spring 73 (i.e. the left end of the centering spring 73) abuts against the first limiting ring 71, and the second end of the centering spring 73 (i.e. the right end of the centering spring 73) abuts against the second limiting ring 72. The abutment positioning of the centering spring 73 is achieved by the first limiting ring 71 and the second limiting ring 72, so that the structure is simple and reliable. In addition, the limiting installation of the elastic centering component 7 in the axial direction is achieved by the first abutting portion 51 and the second abutting portion 52 on the outer peripheral wall of the main valve core 5, so that the structure is simpler and more reliable. In addition, when there is no pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, the elastic force of the centering spring 73 also effectively prevents the main valve core 5 from deviating to the left or right, ensuring that the main valve core 5 is in the middle position.

[0068] Optionally, in this embodiment, if Figure 2 As shown, the first abutment portion 51 is an abutment projection fixedly sleeved on the outer peripheral wall of the main valve core 5. In other embodiments, the first abutment portion 51 may be a positioning shoulder disposed on the outer peripheral wall of the main valve core 5. Optionally, in this embodiment, the second abutment portion 52 is a positioning shoulder disposed on the outer peripheral wall of the main valve core 5. In other embodiments, the second abutment portion 52 may also be an abutment projection fixedly sleeved on the outer peripheral wall of the main valve core 5.

[0069] In this embodiment, if Figure 1 and Figure 2 As shown, the pilot-controlled solenoid valve further includes an elastic reset component 8, which is configured to always have a tendency to hinder the movement of the pilot valve core 6. By providing the elastic reset component 8, when the second coil 22 and the first coil 21 are both in a power-off state, the pilot valve core 6 is easily reset to the middle position under the elastic force of the elastic reset component 8.

[0070] Optionally, in this embodiment, if Figure 1 and Figure 2As shown, a third abutment 4121 is provided on the outer peripheral wall of the connecting rod 412, and a fourth abutment 61 is provided on the outer peripheral wall of the pilot valve core 6, the third abutment 4121 and the fourth abutment 61 are arranged at intervals along the axial direction of the pilot valve core 6 (the left and right direction in the figure), and the elastic reset assembly 8 includes a third limiting ring 81, a fourth limiting ring 82 and a reset spring 83, the third limiting ring 81 and the fourth limiting ring 82 are arranged at intervals along the axial direction of the pilot valve core 6, the third limiting ring 81 is sleeved on the outer periphery of the connecting rod 412, and the side of the third limiting ring 81 away from the fourth limiting ring 82 (that is, the left side of the third limiting ring 81) can abut against the stop iron 42, and the third limiting ring The side of the ring 81 away from the fourth limiting ring 82 abuts against the third abutment portion 4121, the fourth limiting ring 82 is sleeved on the outer periphery of the pilot valve core 6, the side of the fourth limiting ring 82 away from the third limiting ring 81 (i.e. the right side of the fourth limiting ring 82) can abut against the stop iron 42, and the side of the fourth limiting ring 82 away from the third limiting ring 81 abuts against the fourth abutment portion 61, the return spring 83 is sleeved on the outer periphery of the connection between the connecting rod 412 and the pilot valve core 6, the first end of the return spring 83 (i.e. the left end of the return spring 83) abuts against the third limiting ring 81, and the second end of the return spring 83 (i.e. the right end of the return spring 83) abuts against the fourth limiting ring 82. Specifically, when the first coil 21 located on the right side is energized, the moving iron 411 drives the pilot valve core 6 to move to the right under the action of the magnetic field force, at which time the third abutting portion 4121 pushes the reset spring 83 to the right, and the fourth stop ring 82 is abutted by the stop iron 42, so that the reset spring 83 is compressed. When the first coil 21 located on the right side loses power, the pilot valve core 6 moves to the left under the elastic force of the reset spring 83 and resets to the middle position; when the second coil 22 located on the left side is energized, the moving iron 411 drives the pilot valve core 6 to move to the left under the action of the magnetic field force, at which time the fourth abutting portion 61 pushes the reset spring 83 to the left, and the third stop ring 81 is abutted by the stop iron 42, so that the reset spring 83 is compressed. When the second coil 22 located on the left side loses power, the pilot valve core 6 moves to the right under the elastic force of the reset spring 83 and resets to the middle position. The abutment positioning of the reset spring 83 is achieved by setting the third stop ring 81 and the fourth stop ring 82, so that the structure is simple and reliable. In addition, the third abutting portion 4121 and the fourth abutting portion 61 are provided to realize the limiting installation of the elastic reset assembly 8 in the axial direction, making the structure simpler and more reliable.

[0071] Optionally, in this embodiment, the third abutting portion 4121 is an abutting protrusion disposed on the outer peripheral wall of the connecting rod 412. Optionally, in this embodiment, the fourth abutting portion 61 is an abutting protrusion disposed on the outer peripheral wall of the pilot valve core 6.

[0072] In this embodiment, if Figure 1 and Figure 2As shown, the valve sleeve 3 is provided with a first oil port 31, a second oil port 32, a third oil port 33, a fourth oil port 34 and a fifth oil port 35 in sequence from right to left along its axial direction, a first oil delivery hole 53 communicating with the first pressure oil chamber p1 is provided on the main valve core 5, and a second oil delivery hole 54 communicating with the second pressure oil chamber p2 is also provided on the main valve core 5, and a pilot oil circuit is provided on the pilot valve core 6. The pilot oil circuit connects or blocks the first pressure oil chamber p1 when the pilot valve core 6 moves relative to the main valve core 5, and the pilot oil circuit connects or blocks the second pressure oil chamber p2 when the pilot valve core 6 moves relative to the main valve core 5, thereby adjusting the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2.

[0073] Optionally, in this embodiment, if Figure 2 As shown, in order to facilitate the design of the specific structure of the first pressure oil chamber p1 and the second pressure oil chamber p2, step surfaces 36 are provided on the inner walls at both ends of the valve sleeve 3, and a shaft seal 37 is fitted on each step surface 36. The shaft seal 37 is installed and limited by a retaining ring 38 and the step surface 36. The end surface of one shaft seal 37, the inner wall of the valve sleeve 3 and the outer wall of the main valve core 5 cooperate to form the first pressure oil chamber p1, and the end surface of the other shaft seal 37, the inner wall of the valve sleeve 3 and the outer wall of the main valve core 5 cooperate to form the second pressure oil chamber p2.

[0074] Optionally, in this embodiment, if Figure 2 As shown, the valve sleeve 3 and the main valve core 5 cooperate to form a third annular chamber b4 and a fourth annular chamber b5, a connecting boss 56 is provided between the third annular chamber b4 and the fourth annular chamber b5, and a connecting hole 561 for connecting the third oil port 33 and the pilot oil circuit is opened on the connecting boss 56. When the main valve core 5 moves, the third annular chamber b4 can make the second oil port 32 connect to or block the first oil port 31, the third annular chamber b4 can make the second oil port 32 connect to or block the third oil port 33, the fourth annular chamber b5 can make the fourth oil port 34 connect to or block the third oil port 33, and the fourth annular chamber b5 can make the fourth oil port 34 connect to or block the fifth oil port 35.

[0075] In order to facilitate the installation of the pilot-controlled solenoid valve and provide sealing when in use, in this embodiment, Figure 2 As shown, a retaining boss 39 is provided between the first oil port 31 , the second oil port 32 , the third oil port 33 , the fourth oil port 34 and the fifth oil port 35 , each retaining boss 39 is provided with a sealing groove, two sealing retaining rings 391 are provided on the sealing groove, and a sealing ring 392 is clamped between the sealing retaining rings 391 .

[0076] Optionally, in this embodiment, if Figure 1 and Figure 2As shown, the first oil port 31 and the fifth oil port 35 are oil inlets, that is, the first oil port 31 and the fifth oil port 35 are connected to the oil source for providing high-pressure oil, the second oil port 32 and the fourth oil port 34 are working oil ports for connecting to the load, such as the rod chamber and the rodless chamber of the oil cylinder, the third oil port 33 is an oil unloading port, and the third oil port 33 is used to connect to the oil tank; an annular cavity b is provided between the main valve core 5 and the pilot valve core 6, and the annular cavity b can be connected to the first pressure oil chamber p1 or the second pressure oil chamber p2, and the shoulders at both ends of the annular cavity b are respectively used to seal the first oil delivery hole 53 and the second oil delivery hole 54, and the pilot valve core 6 is respectively provided with a first channel 63 and a second channel 64 at both ends of the axial direction thereof, and the first channel 63, the second channel 64 and the annular cavity b are connected to form a pilot oil circuit, and the side wall of the main valve core 5 is provided with a valve hole 55 connected to the first pressure oil chamber p1 and the second pressure oil chamber p2 along its axial direction, and the valve hole 55 is connected to the oil inlet.

[0077] In order to prevent the armature assembly 4, the main valve core 5 and the pilot valve core 6 from getting stuck during the movement, the first channel 63, the annular cavity b and the oil unloading port are connected to form a first pressure relief flow channel, and the end of the pilot valve core 6 is provided with an oil inlet hole 65 connected to the inner cavity of the magnetic sleeve 1 along its radial direction, and the oil inlet hole 65 is connected to the second channel 64, and the oil inlet hole 65, the second channel 64, the annular cavity b and the oil unloading port are connected to form a second pressure relief flow channel. The oil in the magnetic sleeve 1 can be connected to the second pressure relief flow channel through the gap to return to the oil tank for pressure relief, so as to prevent the armature assembly 4, the main valve core 5 and the pilot valve core 6 from getting stuck during the movement.

[0078] Specifically, refer to Figure 1 and Figure 2As shown, when the first coil 21 and the second coil 22 are both de-energized, the main valve core 5 is in the middle position under the action of the elastic centering component 7, and the first oil port 31 and the fifth oil port 35 as oil inlets are closed by the main valve core 5 and cannot be connected with other oil ports. At this time, the high-pressure oil in the pilot oil circuit cannot enter the first pressure oil chamber p1 and the second pressure oil chamber p2; when the first coil 21 is energized, the moving iron 411 compresses the return spring 83 to the right under the action of the magnetic field force to push the pilot valve core 6 to move to the right. At this time, the second pressure oil chamber p2 and the oil inlet are connected to high pressure. At the same time, the oil in the first pressure oil chamber p1 enters the annular chamber b through the first oil delivery hole 53 and reaches the third oil port 33 to flow into the oil tank for pressure relief, that is, the second pressure oil chamber p2 is high pressure, and the first pressure oil chamber p1 is low pressure. Due to the pressure difference, the main valve core 5 is pushed to compress the centering spring 73 to move to the right, so that the first oil port 31 is connected to the third annular chamber b4 and then to the second oil port 32. Similarly, the fourth oil port 3 4 is connected to the fifth oil port 35; when the above action is completed, the shoulder on the pilot valve core 6 and the oil delivery hole on the main valve core 5 are realigned, and the first pressure oil chamber p1 and the second pressure oil chamber p2 are closed again. At this time, due to the inertia of the main valve core 5 moving to the right, it continues to move to the right after aligning with the pilot valve core 6. At this time, the oil in the second pressure oil chamber p2 enters the annular chamber b through the second oil delivery hole 54 to reach the third oil port 33 and flows into the oil tank for pressure relief, and the first pressure oil chamber p1 stops pressure relief. That is, the second pressure oil chamber p2 is at low pressure, and the first pressure oil chamber p1 is at high pressure. Due to the pressure difference, the main valve core 5 is pushed to move to the left, so that the main valve core 5 and the pilot valve core 6 can be automatically returned to alignment; when the first coil 21 loses power, the elastic force of the reset spring 83 pushes the moving iron 411 to drive the pilot valve core 6 back to the middle position, and the main valve core 5 follows the pilot valve core 6 to return to the middle position under the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2. At this time, the oil ports are not connected. Similarly, when the second coil 22 is energized, the moving iron 411 drives the pilot valve core 6 to move to the left, and the main valve core 5 compresses the centering spring 73 and moves to the left under the action of the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, so that the second oil port 32 and the third oil port 33 are connected, and the fourth oil port 34 and the fifth oil port 35 are connected, thereby realizing the reversing function of the pilot-controlled solenoid valve; when the second coil 22 loses power, at this time, the main valve core 5 and the pilot valve core 6 can automatically return to the middle position, and the aperture size of the valve hole 55 can be adjusted according to the response time of the pilot-controlled solenoid valve.

[0079] Embodiment 2

[0080] The pilot-controlled solenoid valve provided in this embodiment is substantially the same as that in the first embodiment. The pilot-controlled solenoid valve provided in this embodiment is different from that in the first embodiment in that:

[0081] In this embodiment, if Figure 4 and Figure 5As shown, a fourth abutment portion 61 is provided on the outer peripheral wall of the connecting rod 412, and the return spring 83 is sleeved on the outer periphery of the connecting rod 412. Optionally, in this embodiment, the fourth abutment portion 61 is an abutment protrusion provided on the outer peripheral wall of the connecting rod 412.

[0082] In this embodiment, if Figure 4 and Figure 5 As shown, the second abutting portion 52 is an abutting protrusion fixedly sleeved on the outer peripheral wall of the main valve core 5 .

[0083] Optionally, in this embodiment, refer to Figure 4 and Figure 5 As shown, the first oil port 31 and the fifth oil port 35 are oil unloading ports connected to the oil tank, the second oil port 32 and the fourth oil port 34 are working oil ports for connecting to the load, such as the rod chamber and the rodless chamber of the oil cylinder, and the third oil port 33 is an oil inlet port connected to the oil source for providing high-pressure oil; a first annular cavity b1 and a second annular cavity b2 are provided between the pilot valve core 6 and the main valve core 5, and when the pilot valve core 6 and the main valve core 5 move relative to each other, the first annular cavity b1 can be connected to the first pressure oil cavity p1, or the second annular cavity b2 can be connected to the second pressure oil cavity p2; in addition, the pilot valve core 6 is provided with a first Shoulder 66, the pilot valve core 6 is also provided with a second shoulder 67 for sealing the second oil delivery hole 54, and an oil hole 6a is opened on the outer side (i.e. the right side) of the first shoulder 66, and an oil hole 6a is also opened on the outer side (i.e. the left side) of the second shoulder 67. The pilot valve core 6 is axially provided with an oil passage 611, and the two oil holes 6a are connected with the third oil port 33 through the oil passage 611 to form a pilot oil circuit; the main valve core 5 is provided with two oil unloading holes 57, and the two oil unloading holes 57 are respectively connected with the first oil port 31 and the fifth oil port 35, and the two oil unloading holes 57 are respectively connected with the first annular cavity b1 and the second annular cavity b2.

[0084] In order to prevent the armature assembly 4, the main valve core 5 and the pilot valve core 6 from getting stuck during the movement, a first blind hole 58 is axially arranged at the right end of the main valve core 5, and a first connecting hole 581 communicating with the first blind hole 58 is arranged on the outer wall of the main valve core 5. The first connecting hole 581 is communicated with the first oil port 31, and the first blind hole 58, the first connecting hole 581 and the first oil port 31 cooperate to form a first pressure relief flow channel, and the oil at the first blind hole 58 returns to the oil tank through the first pressure relief flow channel for pressure relief; at the same time, the left end of the main valve core 5 A second blind hole 59 communicating with the inner cavity of the magnetic sleeve 1 is axially provided at the end thereof, and a second connecting hole 591 communicating with the second blind hole 59 is provided on the outer wall of the main valve core 5, and the second connecting hole 591 is connected with the fifth oil port 35. The second blind hole 59, the second connecting hole 591 and the fifth oil port 35 cooperate to form a second pressure relief channel, and the oil in the magnetic sleeve 1 can be connected with the second pressure relief channel through the gap and return to the oil tank for pressure relief, so as to avoid the armature assembly 4, the main valve core 5 and the pilot valve core 6 from getting stuck during the movement.

[0085] Specifically, refer to Figure 4 and Figure 5 As shown in the figure, when the first coil 21 and the second coil 22 are both de-energized, the main valve core 5 is in the middle position under the action of the elastic centering component 7, and the third oil port 33 is the oil inlet port and is closed by the main valve core 5, and cannot be connected with other oil ports. At this time, the high-pressure oil in the pilot oil circuit cannot enter the first pressure oil chamber p1 and the second pressure oil chamber p2; when the first coil 21 is energized, the moving iron 411 compresses the reset spring 83 to the right under the action of the magnetic field force, pushing the pilot valve core 6 to move to the right. At this time, the pilot oil circuit is The high-pressure oil enters the second pressure oil chamber p2. At the same time, the oil in the first pressure oil chamber p1 enters the second annular chamber b2 through the oil hole 6a and reaches the first oil port 31 to flow into the oil tank for pressure relief. That is, the second pressure oil chamber p2 is at high pressure, and the first pressure oil chamber p1 is at low pressure. Due to the pressure difference, the main valve core 5 is pushed to the right to compress the centering spring 73 to move to the right, so that the first oil port 31 is connected to the third annular chamber b4 and then to the second oil port 32. Similarly, the fourth oil port 34 is connected to the fifth oil port 35. When the above-mentioned action is completed, the shoulder on the pilot valve core 6 and the oil delivery hole on the main valve core 5 are realigned, and the first pressure oil chamber p1 and the second pressure oil chamber p2 are closed again. At this time, due to the inertia of the main valve core 5 moving to the right, it continues to move to the right after aligning with the pilot valve core 6. At this time, the high-pressure oil in the pilot oil circuit enters the first pressure oil chamber p1, and the oil in the second pressure oil chamber p2 enters the first annular chamber b1 through the oil hole 6a to reach the fourth oil port 34 and flows into the oil tank for Pressure relief, that is, the second pressure oil chamber p2 is at low pressure, and the first pressure oil chamber p1 is at high pressure. Due to the pressure difference, the main valve core 5 is pushed to move to the left, so that the main valve core 5 and the pilot valve core 6 can be automatically returned to alignment; when the first coil 21 loses power, the elastic force of the reset spring 83 pushes the moving iron 411 to drive the pilot valve core 6 back to the middle position, and the main valve core 5 follows the pilot valve core 6 to return to the middle position under the action of the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2. At this time, the oil ports are not connected. Similarly, when the second coil 22 is energized, the moving iron 411 drives the pilot valve core 6 to move to the left, and the main valve core 5 moves to the left under the action of the pressure difference between the first pressure oil chamber p1 and the second pressure oil chamber p2, so that the second oil port 32 and the third oil port 33 are connected, and the fourth oil port 34 and the fifth oil port 35 are connected, thereby realizing the reversing function of the pilot-controlled solenoid valve; when the second coil 22 loses power, at this time, the main valve core 5 and the pilot valve core 6 can automatically return to the middle position, and the aperture size of the oil hole 6a can be adjusted according to the response time of the solenoid valve.

[0086] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pilot-controlled solenoid valve, characterized in that: include: Magnetic conductive sleeve (1); A coil (2), wherein the coil (2) is sleeved on the outer circumference of the magnetic conductive sleeve (1); A valve sleeve (3), the valve sleeve (3) being connected to the end of the magnetic sleeve (1), and the valve sleeve (3) being provided with a plurality of oil ports at intervals; An armature assembly (4), the armature assembly (4) comprising a movable iron piece (41), the movable iron piece (41) being inserted into the magnetic sleeve (1) and being able to move relative to the magnetic sleeve (1) along the axial direction of the magnetic sleeve (1) in response to the electromagnetic force generated by the coil (2); A main valve core (5) is inserted into the valve sleeve (3) and can move relative to the valve sleeve (3) along the axial direction of the valve sleeve (3) to connect or block the plurality of oil ports. The valve sleeve (3) and the main valve core (5) cooperate to form a first pressure oil chamber (p1) and a second pressure oil chamber (p2). The pressure difference between the first pressure oil chamber (p1) and the second pressure oil chamber (p2) can drive the main valve core (5) to move. A pilot valve core (6) is inserted into the main valve core (5), the pilot valve core (6) is fixedly connected to the movable iron member (41), and the movable iron member (41) drives the pilot valve core (6) to move relative to the main valve core (5) to adjust the pressure difference between the first pressure oil chamber (p1) and the second pressure oil chamber (p2); as well as An elastic centering component (7) is arranged on the main valve core (5), and the elastic centering component (7) is configured to always have a tendency to hinder the main valve core (5) from moving relative to the valve sleeve (3).

2. The pilot-controlled solenoid valve according to claim 1, characterized in that: A first abutment portion (51) and a second abutment portion (52) are provided on the outer peripheral wall of the main valve core (5), and the first abutment portion (51) and the second abutment portion (52) are arranged at intervals along the axial direction of the main valve core (5); The armature assembly (4) further comprises an iron stop (42) fixedly arranged and inserted into the magnetic conductive sleeve (1); The elastic centering component (7) comprises a first limiting ring (71), a second limiting ring (72) and a centering spring (73), wherein the first limiting ring (71) and the second limiting ring (72) are both sleeved on the outer periphery of the main valve core (5), and the first limiting ring (71) and the second limiting ring (72) are arranged at intervals along the axial direction of the main valve core (5), and the side of the first limiting ring (71) away from the second limiting ring (72) can abut against the stop iron (42), and the first limiting ring (71) away from the second limiting ring (7 2) is in contact with the first abutment portion (51), the side of the second limiting ring (72) away from the first limiting ring (71) can be in contact with the valve sleeve (3), and the side of the second limiting ring (72) away from the first limiting ring (71) is in contact with the second abutment portion (52), the centering spring (73) is sleeved on the outer periphery of the main valve core (5), the first end of the centering spring (73) is in contact with the first limiting ring (71), and the second end of the centering spring (73) is in contact with the second limiting ring (72).

3. The pilot-controlled solenoid valve according to claim 2, characterized in that: The first abutment portion (51) is an abutment protrusion fixedly sleeved on the outer peripheral wall of the main valve core (5), or the first abutment portion (51) is a positioning shoulder arranged on the outer peripheral wall of the main valve core (5); The second abutment portion (52) is an abutment protrusion fixedly sleeved on the outer peripheral wall of the main valve core (5), or the second abutment portion (52) is a positioning shoulder arranged on the outer peripheral wall of the main valve core (5).

4. The pilot-controlled solenoid valve according to claim 2, characterized in that: The movable iron member (41) comprises: a moving iron (411), wherein the moving iron (411) and the stop iron (42) are arranged at intervals along the axial direction of the main valve core (5), and the stop iron (42) can abut against the moving iron (411) to limit the limit position of the moving iron (411) moving relative to the magnetic conductive sleeve (1) toward the valve sleeve (3); and A connecting rod (412), wherein the first end of the connecting rod (412) is connected to the inner cavity of the moving iron (411), the second end of the connecting rod (412) is inserted into the inner cavity of the stop iron (42), and the second end of the connecting rod (412) is fixedly connected to the pilot valve core (6).

5. The pilot-controlled solenoid valve according to claim 4, characterized in that: The pilot-controlled solenoid valve further comprises: An elastic reset component (8) is configured to always have a tendency to hinder the movement of the pilot valve core (6).

6. The pilot-controlled solenoid valve according to claim 5, characterized in that: A third abutment portion (4121) is provided on the outer peripheral wall of the connecting rod (412), and a fourth abutment portion (61) is provided on the outer peripheral wall of the pilot valve core (6) or on the outer peripheral wall of the connecting rod (412), and the third abutment portion (4121) and the fourth abutment portion (61) are arranged at intervals along the axial direction of the pilot valve core (6); The elastic reset assembly (8) comprises a third limiting ring (81), a fourth limiting ring (82) and a reset spring (83), wherein the third limiting ring (81) and the fourth limiting ring (82) are arranged at intervals along the axial direction of the pilot valve core (6), the third limiting ring (81) is sleeved on the outer periphery of the connecting rod (412), the side of the third limiting ring (81) away from the fourth limiting ring (82) can abut against the stop iron (42), and the side of the third limiting ring (81) away from the fourth limiting ring (82) abuts against the third abutting portion (4121), the fourth limiting ring (82) is sleeved on the outer periphery of the pilot valve core (6) or the connecting rod (412), the side of the fourth limiting ring (82) away from the third limiting ring (81) can abut against the stop iron (42), and the side of the fourth limiting ring (82) away from the third limiting ring (81) abuts against the fourth abutting portion (61), the first end of the reset spring (83) abuts against the third limiting ring (81), and the second end of the reset spring (83) abuts against the fourth limiting ring (82).

7. The pilot-controlled solenoid valve according to any one of claims 1 to 6, characterized in that: The valve sleeve (3) is provided with a first oil port (31), a second oil port (32), a third oil port (33), a fourth oil port (34) and a fifth oil port (35) in sequence and spaced apart along its axial direction; The main valve core (5) is provided with a first oil delivery hole (53) communicating with the first pressure oil chamber (p1), and the main valve core (5) is also provided with a second oil delivery hole (54) communicating with the second pressure oil chamber (p2); The pilot valve core (6) is provided with a pilot oil circuit, and the pilot oil circuit is connected to or blocked from the first pressure oil chamber (p1) when the pilot valve core (6) moves relative to the main valve core (5), and the pilot oil circuit is connected to or blocked from the second pressure oil chamber (p2) when the pilot valve core (6) moves relative to the main valve core (5).

8. The pilot-controlled solenoid valve according to claim 7, characterized in that: The first oil port (31) and the fifth oil port (35) are oil inlet ports, the second oil port (32) and the fourth oil port (34) are working oil ports, and the third oil port (33) is an oil discharge port; An annular cavity (b) is provided between the main valve core (5) and the pilot valve core (6), the annular cavity (b) being connectable to the first pressure oil cavity (p1) or the second pressure oil cavity (p2), and shoulders at both ends of the annular cavity (b) being used to seal the first oil delivery hole (53) and the second oil delivery hole (54) respectively; The pilot valve core (6) is provided with a first channel (63) and a second channel (64) at two ends along its axial direction, respectively; the first channel (63), the second channel (64) and the annular cavity (b) are connected to form the pilot oil circuit; A valve hole (55) communicating with the first pressure oil chamber (p1) and the second pressure oil chamber (p2) is formed on the side wall of the main valve core (5) along its axial direction, and the valve hole (55) is communicated with the oil inlet.

9. The pilot-controlled solenoid valve according to claim 8, characterized in that: The first channel (63), the annular cavity (b) and the oil unloading port are connected to form a first pressure relief channel; An oil inlet hole (65) is provided at the end of the pilot valve core (6) along its radial direction and is connected to the inner cavity of the magnetic sleeve (1); the oil inlet hole (65) is connected to the second channel (64); the oil inlet hole (65), the second channel (64), the annular cavity (b) and the oil unloading port are connected to form a second pressure relief channel.

10. The pilot-controlled solenoid valve according to claim 7, characterized in that: The valve sleeve (3) and the main valve core (5) cooperate to form a third annular cavity (b4) and a fourth annular cavity (b5); a connecting boss (56) is provided between the third annular cavity (b4) and the fourth annular cavity (b5); a connecting hole (561) for connecting the third oil port (33) and the pilot oil circuit is provided on the connecting boss (56); When the main valve core (5) moves, the third annular cavity (b4) can connect the second oil port (32) to or block the first oil port (31), the third annular cavity (b4) can connect the second oil port (32) to or block the third oil port (33), the fourth annular cavity (b5) can connect the fourth oil port (34) to or block the third oil port (33), and the fourth annular cavity (b5) can connect the fourth oil port (34) to or block the fifth oil port (35).

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