Hydraulic control device

Abstract

A hydraulic control device includes a valve body; a main valve core, when the main valve core is located near a low-pressure valve cavity, both the high-pressure inlet and the high-pressure outlet are connected to a first cavity, when the main valve core is located away from the low-pressure valve cavity, the main valve core separates the high-pressure outlet from the first cavity to close the high-pressure outlet; a moving valve core, which can slide along the axial direction of the valve cavity through hole, and a moving valve core hole and a pressure relief hole are provided in the moving valve core, and the pressure relief hole connects the moving valve core hole and the low-pressure valve cavity; a control unit, including a driving unit and an opening and closing unit, and the driving unit drives the opening and closing unit to open or close the pressure relief hole. The main valve core of the hydraulic control device of the present invention controls the opening and closing state of the high-pressure outlet in the valve body, and the external driving force acts to open or close the pressure relief hole, rather than directly driving the main valve core to move, thereby avoiding the influence of the pressure of the main oil circuit, having high sensitivity, and improving the reliability of the hydraulic control device.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic equipment, and in particular to a hydraulic control device. Background Art

[0002] In the hydraulic system, the hydraulic valve is an important component of the hydraulic system. The hydraulic valve is responsible for controlling the opening and closing of the oil circuit and the degree of opening and closing, thereby controlling the on-off or flow of the oil.

[0003] Existing hydraulic valves include mechanical drive, electromagnetic drive and hydraulic drive, among which the hydraulic valve driven by hydraulic drive is a hydraulic servo valve.

[0004] Most of the existing hydraulic valves have independent drive units to control the movement of the valve core, and the valve core controls the opening and closing of the main oil circuit. The power of the drive unit of the mechanically driven hydraulic valve comes from mechanical force, the power of the drive unit of the solenoid valve comes from electromagnetic force, and the power of the drive unit of the hydraulically driven hydraulic valve comes from pilot oil.

[0005] Since the valve core is arranged in the main oil circuit, during the opening and closing process of the main oil circuit, the valve core will be affected by the pressure oil in the main oil circuit, resulting in the problem of insensitive response of the existing hydraulic valve, resulting in insufficient reliability of the hydraulic valve. Summary of the invention

[0006] The object of the present invention is to provide a hydraulic control device which can sensitively respond to the driving force of a driving part, avoid being affected by the pressure of a main oil circuit, and has higher reliability.

[0007] The present invention is achieved in that:

[0008] A hydraulic control device comprises a valve body, wherein a high-pressure valve chamber, a low-pressure valve chamber, a valve chamber through hole, a high-pressure inlet and a high-pressure outlet are arranged in the valve body, and the high-pressure valve chamber and the low-pressure valve chamber are connected through the valve chamber through hole; a main valve core is arranged in the high-pressure valve chamber in an axially sliding manner along the valve chamber through hole, the main valve core cooperates with the high-pressure valve chamber, the main valve core divides the high-pressure valve chamber into a first cavity and a second cavity, and the valve chamber through hole is connected with the second cavity, when the main valve core is located near the low-pressure valve chamber, the high-pressure inlet and the high-pressure outlet are both connected with the first cavity, and when the main valve core is located far away from the low-pressure valve chamber, the main valve core separates the high-pressure outlet from the first cavity to close the low-pressure valve chamber. A high-pressure outlet, a main valve core hole is arranged in the main valve core, one end of the main valve core hole is connected with the high-pressure inlet, and the other end of the main valve core hole is connected with the second cavity; a moving valve core can slide along the axial direction of the valve cavity through hole, and comprises a large-diameter section and a small-diameter section, the large-diameter section is arranged in the low-pressure valve cavity, one end of the small-diameter section passes through the valve cavity through hole and abuts against the main valve core, a moving valve core hole and a pressure relief hole are arranged in the moving valve core, the moving valve core hole passes through the end of the large-diameter section away from the small-diameter section, the moving valve core hole is connected with the second cavity, and the pressure relief hole connects the moving valve core hole and the low-pressure valve cavity; a control part, comprises a driving part and an opening and closing part, and the driving part drives the opening and closing part to open or close the pressure relief hole.

[0009] The main valve core of the hydraulic control device of the present invention controls the opening and closing state of the high-pressure outlet circuit in the valve body, thereby controlling the opening and closing state of the main oil circuit. The main valve core is pushed by the moving valve core, and the moving valve core is driven to move by the upper and lower pressure differences. When the pressure relief hole on the moving valve core is connected, the moving valve core is in a pressure balance state. When the pressure relief hole is closed, the pressure oil of the high-pressure inlet circuit acts on the end of the large diameter section and the end of the small diameter section of the moving valve core at the same time. The force bearing area of ​​the end of the large diameter section of the moving valve core is larger than the force bearing area of ​​the end of the small diameter section. Therefore, a pressure difference is generated between the end of the large diameter section and the end of the small diameter section of the moving valve core, which pushes the moving valve core to move toward the main valve core, and then pushes the main valve core to move. It can be seen that the external driving force of the hydraulic control device of the present invention serves to open or close the pressure relief hole, rather than directly drive the main valve core to move. Therefore, it avoids being affected by the pressure of the main oil circuit, has high sensitivity, and improves the reliability of the hydraulic control device.

[0010] In a preferred embodiment of the present invention, the opening and closing portion includes a valve core sleeve, which is arranged in the low-pressure valve cavity and sleeved on the outside of the moving valve core. The valve core sleeve can slide along the axial direction of the moving valve core. When the valve core sleeve is located away from the high-pressure valve cavity, the pressure relief hole connects the moving valve core hole and the low-pressure valve cavity. When the valve core sleeve moves a certain distance toward the high-pressure valve cavity, the valve core sleeve closes the pressure relief hole. The driving portion is drivingly connected to the valve core sleeve to drive the valve core sleeve to slide along the axial direction of the moving valve core.

[0011] In a preferred embodiment of the present invention, the driving part includes a piston mechanism, and a piston rod of the piston mechanism is drivingly connected to the valve core sleeve.

[0012] In a preferred embodiment of the present invention, the piston mechanism includes: a pilot block connected to the valve body, a piston chamber and a pilot passage are provided in the pilot block, the pilot passage is connected to the piston chamber, and the piston chamber is connected to the low-pressure valve chamber; a piston rod is slidably arranged in the piston chamber, and one end of the piston rod facing the low-pressure valve chamber abuts against the valve core sleeve.

[0013] In a preferred embodiment of the present invention, the hydraulic control device also includes a valve core sleeve elastic element, which is connected to the valve core sleeve. When the valve core sleeve moves toward the high-pressure valve chamber, the valve core sleeve elastic element applies a force to the valve core sleeve away from the high-pressure valve chamber.

[0014] In a preferred embodiment of the present invention, a movable valve core seat hole is further provided on the pilot block, and at least a portion of the large diameter section is disposed in the movable valve core seat hole.

[0015] In a preferred embodiment of the present invention, the pressure relief hole is opened on the side wall of the small diameter section, and at least a part of the valve core sleeve is sleeved on the outside of the small diameter section and matched with the small diameter section.

[0016] In a preferred embodiment of the present invention, the inner hole of the valve core sleeve includes a first section cooperating with the large diameter section and a second section cooperating with the small diameter section, and a valve core sleeve connecting hole is provided on the side wall of the valve core sleeve, and the valve core sleeve connecting hole connects the first section and the low-pressure valve chamber.

[0017] In a preferred embodiment of the present invention, the moving valve core hole includes a first moving valve core hole arranged in the large diameter section and a second moving valve core hole arranged in the small diameter section, the second moving valve core hole is connected to the second cavity, and the area difference between the cross-section of the first moving valve core hole and the cross-section of the second moving valve core hole is greater than the area difference between the cross-section of the small diameter section and the cross-section of the second moving valve core hole; the hydraulic control device also includes a blocking block, at least a portion of the blocking block is arranged in the first moving valve core hole, the blocking block cooperates with the first moving valve core hole, and the moving valve core can slide relative to the blocking block.

[0018] In a preferred embodiment of the present invention, the valve body includes a first valve body and a second valve body which are sealed and connected, the high-pressure valve chamber is arranged in the first valve body, and the low-pressure valve chamber is arranged in the second valve body.

[0019] The beneficial effects of the present invention are mainly that the hydraulic control device can sensitively respond to the driving force of the driving part, avoid being affected by the pressure of the main oil circuit, and has higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 is a schematic diagram of an embodiment of a hydraulic control device of the present invention in a half-open state;

[0022] Figure 2 For the present invention Figure 1 A partial enlarged view of part A in FIG.

[0023] Figure 3 For the present invention Figure 2 A left view of the component in FIG.

[0024] Figure 4 For the present invention Figure 1 A schematic diagram of some components of an embodiment of a hydraulic control device in FIG.

[0025] Figure 5 For the present invention Figure 1 A schematic diagram of the moving distance of the movable valve core of an embodiment of the hydraulic control device in FIG.

[0026] Figure 6 is a schematic diagram of an embodiment of the hydraulic control device of the present invention in a fully open state;

[0027] Figure 7 For the present invention Figure 6 A partial enlarged view of part B in FIG.

[0028] Figure 8 For the present invention Figure 7 A left view of the component in FIG.

[0029] Fig. 9 This is a relationship diagram between the pilot pressure and the movement amount of the main valve core of the hydraulic control device of the present invention.

[0030] In the figure:

[0031] 10-valve body; 11-first valve body; 12-second valve body; 101-high-pressure valve chamber; 1011-first chamber; 1012-second chamber; 102-low-pressure valve chamber; 103-high-pressure inlet; 104-high-pressure outlet; 20-main valve core; 21-main valve core hole; 30-moving valve core; 31-large diameter section; 32-small diameter section; 33-moving valve core hole; 331-first moving valve core hole; 332-second moving valve core hole; 34-pressure relief hole; 35-high-pressure connecting hole; 40-valve core sleeve; 401-first section; 402-second section; 403-valve core sleeve connecting hole; 41-valve core sleeve elastic element; 51-pilot block; 511-piston chamber; 512-pilot passage; 513-moving valve core seat hole; 52-piston rod; 60-block. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They 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 addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0036] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of 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.

[0038] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0039] In the following descriptions, “up”, “down”, “left” and “right” are Figure 1 The paper direction is not the direction in actual application. This description is only for simplification and does not constitute an improper limitation on the present invention.

[0040] like Figures 1 to 9 An embodiment of the hydraulic control device of the present invention is shown. In this embodiment, the valve body 10 includes a first valve body 11 and a second valve body 12, the second valve body 12 is connected to the bottom of the first valve body 11, the first valve body 11 has a high-pressure valve chamber 101, and the second valve body 12 has a low-pressure valve chamber 102, wherein a portion of the second valve body 12 extends into the high-pressure valve chamber 101, and a valve chamber through hole connecting the high-pressure valve chamber 101 and the low-pressure valve chamber 102 is opened on the portion of the second valve body 12 extending into the high-pressure valve chamber 101.

[0041] The lower surface of the first valve body 11 and the upper surface of the second valve body 12 are sealed and connected, and a sealing ring is arranged between them.

[0042] The first valve body 11 is also provided with a high-pressure inlet 103 and a high-pressure outlet 104, which are used to connect to the main oil circuit of the hydraulic system. The oil in the main oil circuit flows into the hydraulic control device from the high-pressure inlet 103 and flows out of the hydraulic control device from the high-pressure outlet 104.

[0043] A main valve core 20 is disposed in the high-pressure valve chamber 101 . The main valve core 20 is slidably disposed in the high-pressure valve chamber 101 along the axial direction of the valve chamber through hole, and is used to open or close the high-pressure outlet 104 .

[0044] The main valve core 20 is matched with the inner wall of the high-pressure valve chamber 101 so that the main valve core 20 can shield the high-pressure outlet 104 .

[0045] like Figure 6 As shown, when the main valve core 20 is at the bottom, the communication area of ​​the high-pressure outlet 104 is the largest, and the hydraulic control device is in a fully open state.

[0046] like Figure 1 As shown, when the main valve core 20 moves upward, the main valve core 20 gradually blocks the high-pressure outlet 104, and the communication area of ​​the high-pressure outlet 104 gradually decreases until it is completely closed.

[0047] The main valve core 20 divides the high-pressure valve chamber 101 into a first chamber 1011 located at the top and a second chamber 1012 located at the bottom, and the valve chamber through hole is connected to the second chamber 1012 .

[0048] A main valve core hole 21 is provided in the main valve core 20 , the upper end of the main valve core hole 21 is connected to the high-pressure inlet 103 , the lower end of the main valve core hole 21 is connected to the second cavity 1012 , and the first cavity 1011 and the second cavity 1012 are connected through the main valve core hole 21 .

[0049] In this embodiment, the main valve core hole 21 further includes a throttling section, and the throttling section is a necked structure.

[0050] The hydraulic control device further comprises a moving valve core 30 , which can slide along the axial direction of the valve cavity through hole, so the moving valve core 30 is used to push the main valve core 20 to move up and down.

[0051] The movable valve core 30 includes a large diameter section 31 and a small diameter section 32 . The large diameter section 31 is disposed in the low-pressure valve cavity 102 , and one end of the small diameter section 32 passes through the valve cavity through hole and abuts against the main valve core 20 .

[0052] A moving valve core hole 33 is provided in the moving valve core 30, and the moving valve core hole 33 includes a first moving valve core hole 331 provided in the large diameter section 31 and a second moving valve core hole 332 provided in the small diameter section 32, and the second moving valve core hole 332 is connected to the second cavity 1012, and the area difference between the cross-section of the first moving valve core hole 331 and the cross-section of the second moving valve core hole 332 is greater than the area difference between the cross-section of the small diameter section and the cross-section of the second moving valve core hole 332.

[0053] When the moving valve core 30 is acted upon by the pressurized oil, the area difference between the cross-section of the first moving valve core hole 331 and the cross-section of the second moving valve core hole 332 is the action area of ​​the upward pressure, and the area difference between the cross-section of the small diameter section and the cross-section of the second moving valve core hole 332 is the action area of ​​the downward pressure. Since the action area of ​​the upward pressure is greater than the action area of ​​the downward pressure, the moving valve core 30 is acted upon by an upward resultant force, thereby moving upward.

[0054] The upper end of the movable valve core hole 33 is directly aligned with the main valve core hole 21 , and a high-pressure connecting hole 35 is opened on the side wall of the upper end of the small-diameter section 32 for connecting the second cavity 1012 and the first movable valve core hole 331 to introduce the pressurized oil into the second movable valve core hole 332 .

[0055] A pressure relief hole 34 is provided on the side wall of the small diameter section 32, and the pressure relief hole 34 communicates with the moving valve core hole 33 and the low pressure valve chamber 102. When the pressure relief hole 34 is opened, the moving valve core hole 33 is in a pressure balance state and is not acted upon by hydraulic pressure; when the pressure relief hole 34 is closed, the moving valve core hole 33 is under the action of hydraulic pressure and moves upward under the influence of the pressure difference between the upper and lower parts.

[0056] The control unit of the hydraulic control device is used to open or close the pressure relief hole 34. The control unit includes a driving unit and an opening and closing unit. The driving unit drives the opening and closing unit to open or close the pressure relief hole.

[0057] In this embodiment, the opening and closing part includes a valve core sleeve 40, which is arranged in the low-pressure valve chamber 102 and sleeved on the outside of the moving valve core 30. The valve core sleeve 40 can slide along the axial direction of the moving valve core 30. When the valve core sleeve 40 is located away from the high-pressure valve chamber 101, the pressure relief hole 34 connects the moving valve core hole 33 and the low-pressure valve chamber 102. When the valve core sleeve 40 moves a certain distance toward the high-pressure valve chamber 101, the valve core sleeve 40 closes the pressure relief hole 34.

[0058] The inner hole of the valve core sleeve 40 includes a first section 401 that cooperates with the large diameter section 31 and a second section 402 that cooperates with the small diameter section 32. A valve core sleeve connecting hole 403 is provided on the side wall of the valve core sleeve 40, and the valve core sleeve connecting hole 403 connects the first section 401 and the low-pressure valve chamber 102.

[0059] The driving part includes a piston mechanism, specifically including a pilot block 51 and a piston rod 52 .

[0060] The pilot block 51 is connected to the lower end of the second valve body 12 . A piston chamber 511 and a pilot passage 512 are provided in the pilot block 51 . The pilot passage 512 is in communication with the piston chamber 511 , and the piston chamber 511 is in communication with the low-pressure valve chamber 102 .

[0061] The piston rod 52 is slidably disposed in the piston chamber 511 , and one end of the piston rod 52 facing the low-pressure valve chamber 102 abuts against the valve core sleeve 40 .

[0062] In this embodiment, the pilot passage 512 is connected to the pilot oil circuit for controlling the hydraulic control device. When the pilot passage 512 is pressurized, oil fills the piston chamber 511, pushing the piston rod 52 to move upward, and the piston rod 52 pushes the valve core sleeve 40 to move upward to close the pressure relief hole 34.

[0063] Since the hydraulic oil in the pilot oil circuit is only used to push the piston rod 52 and the valve core sleeve 40, the pressure of the pilot oil circuit can be set relatively low, much lower than the pressure of the main oil circuit.

[0064] like Figure 4 As shown, the hydraulic control device also includes a valve core sleeve elastic element 41, which is connected to the valve core sleeve 40. When the valve core sleeve 40 moves toward the high-pressure valve chamber 101, the valve core sleeve elastic element 41 applies a force to the valve core sleeve 40 away from the high-pressure valve chamber 101.

[0065] The piston mechanism needs to overcome the elastic force of the valve core sleeve elastic element 41 to push the valve core sleeve 40 to move upward.

[0066] Fig. 9The relationship between the pressure of the pilot oil circuit and the moving distance of the main valve core 20 is shown. It can be seen that when the pressure of the pilot oil circuit overcomes the elastic force of the valve core sleeve elastic element 41, the moving distance of the main valve core 20 is linearly related to the pressure of the pilot oil circuit. Therefore, the hydraulic control device has good sensitivity and stability.

[0067] Fig. 9 The pm point in Figure 1 The state of the hydraulic control device in which the movement distance of the main valve core 20 is Figure 5 h shown.

[0068] A movable valve core seat hole 513 is further formed on the pilot block 51 , and at least a portion of the large diameter section 31 is disposed in the movable valve core seat hole 513 .

[0069] The hydraulic control device further includes a block 60 , at least a portion of which is disposed in the first movable valve core hole 331 , the block 60 is overfitted with the first movable valve core hole 331 , and the movable valve core 30 can slide relative to the block 60 .

[0070] The low-pressure valve chamber 102 is communicated with the oil cylinder.

[0071] like Figure 6 and Figure 8 As shown, the hydraulic control device is in a fully open state, and the valve core sleeve 40 covers half of the pressure relief hole 34.

[0072] As the pressure of the pilot oil circuit increases, the valve core sleeve 40 moves upward to cover the pressure relief hole 34. When the pressure relief hole 34 is covered to a certain extent, the pressure in the movable valve core hole 33 increases, and the movable valve core 30 is affected by the pressure of the main oil circuit.

[0073] The pressure oil in the movable valve core hole 33 generates an upward force on the movable valve core 30 . The movable valve core 30 moves upward under the pressure of the main oil circuit, pushing the main valve core 20 to move upward, gradually covering the high-pressure outlet 104 .

[0074] As the moving valve core 30 moves upward, the pressure relief hole 34 reopens, and the pressure oil in the moving valve core hole 33 of the moving valve core 30 is discharged from the pressure relief hole 34 into the low-pressure valve chamber 102. The moving valve core 30 is no longer affected by the pressure of the main oil circuit, and returns to a pressure balance state and no longer moves.

[0075] like Figures 1 to 3 As shown, the pressure of the pilot oil circuit at this time is pm, the moving valve core 30 moves upward a distance of h, and the pressure relief hole 34 is reopened. At this time, the moving valve core 30 is in a pressure balance state, and the main valve core 20 moves upward a distance of h, covering a part of the high-pressure outlet 104, so the hydraulic control device is in a half-open state.

[0076] The pilot oil circuit of the present invention is used to drive the piston rod 52 to move, so low pressure and a small amount of oil can be used to generate driving force, so that the hydraulic control system of the present invention has very high responsiveness and sensitivity.

[0077] The position of the moving valve core 30 is only determined by the position of the valve core sleeve 40. The valve core sleeve 40 is driven by the piston rod 52. The moving valve core 30 is not affected by the pressure of the main oil circuit. The opening and closing degree of the hydraulic control device is linearly related to the external driving force.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic control device, characterized in that: include: A valve body (10), wherein a high-pressure valve chamber (101), a low-pressure valve chamber (102), a valve chamber through hole, a high-pressure inlet (103) and a high-pressure outlet (104) are arranged in the valve body (10), and the high-pressure valve chamber (101) and the low-pressure valve chamber (102) are communicated with each other through the valve chamber through hole; the valve body (10) comprises a first valve body (11) and a second valve body (12) which are sealed and connected, the high-pressure valve chamber (101) is arranged in the first valve body (11), and the low-pressure valve chamber (102) is arranged in the second valve body (12); a part of the structure of the second valve body (12) extends into the high-pressure valve chamber (101), and the valve chamber through hole is opened on the part of the structure of the second valve body (12) extending into the high-pressure valve chamber (101); The main valve core (20) is slidably arranged in the high-pressure valve chamber (101) along the axial direction of the valve chamber through hole. The main valve core (20) cooperates with the high-pressure valve chamber (101). The main valve core (20) divides the high-pressure valve chamber (101) into a first cavity (1011) and a second cavity (1012). The valve chamber through hole is connected to the second cavity (1012). When the main valve core (20) is located near the low-pressure valve chamber (102), the high-pressure inlet (103) and the high-pressure outlet (103) are connected. 04) are both connected to the first cavity (1011); when the main valve core (20) is located away from the low-pressure valve cavity (102), the main valve core (20) separates the high-pressure outlet (104) from the first cavity (1011) to close the high-pressure outlet (104); a main valve core hole (21) is provided in the main valve core (20); one end of the main valve core hole (21) is connected to the high-pressure inlet (103), and the other end of the main valve core hole (21) is connected to the second cavity (1012); A movable valve core (30) capable of sliding axially along the valve cavity through hole, comprising a large diameter section (31) and a small diameter section (32), wherein the large diameter section (31) is arranged in the low-pressure valve cavity (102), and one end of the small diameter section (32) passes through the valve cavity through hole and abuts against the main valve core (20), and a movable valve core hole (33) and a pressure relief hole (34) are arranged in the movable valve core (30), wherein the movable valve core hole (33) passes through the end of the large diameter section (31) away from the small diameter section (32), the movable valve core hole (33) is connected with the second cavity (1012), and the pressure relief hole (34) is connected with the movable valve core hole (33) and the low-pressure valve cavity (102); The control unit includes a driving unit and an opening and closing unit, wherein the driving unit drives the opening and closing unit to open or close the pressure relief hole.

2. The hydraulic control device according to claim 1, characterized in that: The opening and closing portion comprises a valve core sleeve (40), wherein the valve core sleeve (40) is arranged in the low-pressure valve chamber (102) and sleeved on the outer side of the movable valve core (30), and the valve core sleeve (40) can slide along the axial direction of the movable valve core (30). When the valve core sleeve (40) is located away from the high-pressure valve chamber (101), the pressure relief hole (34) communicates with the movable valve core hole (33) and the low-pressure valve chamber (102). When the valve core sleeve (40) moves a certain distance toward the high-pressure valve chamber (101), the valve core sleeve (40) closes the pressure relief hole (34). The driving portion is drivingly connected to the valve core sleeve (40) to drive the valve core sleeve (40) to slide along the axial direction of the movable valve core (30).

3. The hydraulic control device according to claim 2, characterized in that: The driving part comprises a piston mechanism, and a piston rod (52) of the piston mechanism is drivingly connected to the valve core sleeve (40).

4. The hydraulic control device according to claim 3, characterized in that: The piston mechanism comprises: A pilot block (51) is connected to the valve body (10), a piston chamber (511) and a pilot passage (512) are provided in the pilot block (51), the pilot passage (512) is communicated with the piston chamber (511), and the piston chamber (511) is communicated with the low-pressure valve chamber (102); A piston rod (52) is slidably disposed in the piston chamber (511), and one end of the piston rod (52) facing the low-pressure valve chamber (102) abuts against the valve core sleeve (40).

5. The hydraulic control device according to claim 4, characterized in that: The hydraulic control device further comprises a valve core sleeve elastic element (41), wherein the valve core sleeve elastic element (41) is connected to the valve core sleeve (40), and when the valve core sleeve (40) moves toward the high-pressure valve chamber (101), the valve core sleeve elastic element (41) applies a force to the valve core sleeve (40) away from the high-pressure valve chamber (101).

6. The hydraulic control device according to claim 4, characterized in that: The pilot block (51) is also provided with a movable valve core seat hole (513), and at least a portion of the large diameter section (31) is arranged in the movable valve core seat hole (513).

7. The hydraulic control device according to claim 2, characterized in that: The pressure relief hole (34) is provided on the side wall of the small-diameter section (32), and at least a portion of the valve core sleeve (40) is sleeved on the outside of the small-diameter section (32) and matched with the small-diameter section (32).

8. The hydraulic control device according to claim 7, characterized in that: The inner hole of the valve core sleeve (40) includes a first section (401) that cooperates with the large diameter section (31) and a second section (402) that cooperates with the small diameter section (32). A valve core sleeve connecting hole (403) is provided on the side wall of the valve core sleeve (40), and the valve core sleeve connecting hole (403) connects the first section (401) and the low-pressure valve chamber (102).

9. The hydraulic control device according to claim 1, characterized in that: The movable valve core hole (33) includes a first movable valve core hole (331) arranged in the large diameter section (31) and a second movable valve core hole (332) arranged in the small diameter section (32); the second movable valve core hole (332) is connected to the second cavity (1012); the area difference between the cross section of the first movable valve core hole (331) and the cross section of the second movable valve core hole (332) is greater than the area difference between the cross section of the small diameter section and the cross section of the second movable valve core hole (332); the hydraulic control device also includes a blocking block (60); at least a portion of the blocking block (60) is arranged in the first movable valve core hole (331); the blocking block (60) cooperates with the first movable valve core hole (331), and the movable valve core (30) can slide relative to the blocking block (60).

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