Unloading valve and hydraulic system

Abstract

The invention discloses an unloading valve and a hydraulic system, and relates to the technical field of valves, a first valve cavity is formed in a valve body, an input port, an output port and a discharge port which are communicated with the first valve cavity are formed in the valve body, the input port is connected with input equipment, the output port is communicated with an actuator, and the discharge port is connected with working medium storage equipment; the first valve element is located in the first valve cavity. The unloading valve is arranged close to the actuator, and the distance between the actuator and the unloading valve is smaller than the distance between the actuator and the input device, so that the working medium in the actuator can be discharged from the unloading valve only by flowing through a short distance, and the unloading valve is not easy to discharge due to the fact that the input port is disconnected from the output port when the unloading valve is in the pressure relief state. Therefore, a working medium in the actuator can be discharged from the unloading valve at a high flow speed, then the pressure relief efficiency of a hydraulic system adopting the unloading valve is improved, and the probability of safety accidents around the actuator caused by untimely pressure relief of the hydraulic system is reduced.

Description

Technical Field

[0001] The invention relates to the field of valves, and in particular to an unloading valve and a hydraulic system. Background Art

[0002] In the prior art, the pressure relief response time of the hydraulic system is relatively long. For example, a 2,000-meter hydraulic pipeline takes 15 minutes to completely relieve pressure, which makes it impossible for the hydraulic system to achieve rapid pressure relief. When the hydraulic system needs emergency pressure relief, the long pressure relief time will easily cause safety accidents.

[0003] Therefore, how to shorten the pressure relief time of the hydraulic system and reduce the probability of safety accidents has become a technical problem that technical personnel in this field need to solve urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a unloading valve to shorten the pressure relief time of a hydraulic system using the unloading valve of the present invention and reduce the probability of safety accidents.

[0005] To achieve the above object, the present invention provides the following solutions: The present invention provides an unloading valve, which is arranged close to an actuator and comprises: A valve body, wherein a first valve cavity is provided in the valve body, an input port, an output port and a discharge port connected to the first valve cavity are provided on the valve body, the input port is disconnected from the discharge port, the input port is connected to an input device, the output port is connected to the actuator, the discharge port is connected to a working medium storage device, and a distance between the actuator and the unloading valve is smaller than a distance between the actuator and the input device; a first valve core, the first valve core being located in the first valve cavity; a one-way sealing unit, the one-way sealing unit being located in the first valve chamber and being used to prevent the working medium from flowing from the output port and the discharge port to the input port; Wherein, the unloading valve has an open state, a closed state and a pressure relief state, and when the unloading valve is in the closed state, the one-way sealing unit blocks the flow path between the input port and the output port; When the unloading valve is switched from the closed state to the open state, the working medium entering the first valve cavity from the input port exerts a first force on the first valve core, and when the first force is greater than the first opening pressure of the one-way sealing unit, the one-way sealing unit releases the blockage of the flow path, and the input port is connected to the output port; When the unloading valve is switched from the open state to the pressure relief state, the first force is smaller than the first opening pressure, the input port is disconnected from the output port, and the output port is connected to the relief port.

[0006] Preferably, when the unloading valve switches from the open state to the pressure relief state, the working medium entering the first valve cavity from the output port applies a second force to the first valve core, and the second force causes the output port to communicate with the relief port.

[0007] Preferably, the first valve core is slidably connected to the first valve cavity in a first direction; When the unloading valve is switched from the closed state to the open state, and the first force is greater than the second opening pressure, the first valve core moves along the first direction, and the second opening pressure is less than the first opening pressure; when the unloading valve is switched from the open state to the pressure relief state, the second force causes the first valve core to move in the second direction until the first valve core reaches the pressure relief position, and the output port is connected to the discharge port; Wherein, the first direction is set from the input port toward the output port, and the first direction is opposite to the second direction.

[0008] Preferably, the first valve core has a second valve cavity therein, the first valve core is provided with an inlet and an outlet both communicating with the first valve cavity and the second valve cavity, the first valve cavity is provided with the one-way sealing unit, and the one-way sealing unit is used to block the flow channel between the inlet and the outlet; Wherein, the one-way sealing unit comprises a reset member and a first sealing member which are sequentially arranged along the second direction and located on the flow channel, the reset member applies the first opening pressure to the first sealing member, and the first opening pressure causes the first sealing member to block the flow channel; Alternatively, the one-way sealing unit comprises a one-way valve, and the one-way valve is used to block the flow channel; Alternatively, the one-way sealing unit includes second sealing members located on the flow channel and arranged in sequence along the second direction, when the first force is less than the first opening pressure, the second sealing members keep blocking the flow channel, the first direction is arranged from top to bottom, and the first opening pressure is the weight of the second sealing members; Alternatively, the one-way sealing unit includes a third sealing member disposed on the flow channel, and when the first force is less than the first opening pressure, the third sealing member keeps blocking the flow channel.

[0009] Preferably, when the unloading valve is in the pressure relief state, the output port is communicated with the discharge port through the first valve chamber, or the output port is communicated with the discharge port through the first valve core.

[0010] Preferably, the unloading valve comprises a first sealing component and a second sealing component, wherein the first sealing component is arranged between a region of the valve body close to the output port and the first valve core, and the second sealing component is arranged between a region of the valve body close to the input port and the first valve core.

[0011] Preferably, the first sealing assembly includes a first sealing surface provided at one end of the first valve core facing the output port, and a second sealing surface provided at the valve body facing the input port. When the unloading valve is in the open state, the first sealing surface and the second sealing surface form a sealing pair.

[0012] Preferably, the unloading valve also includes a controller, a displacement sensor arranged on the first valve core, a first flow sensor arranged at the output port, and a second flow sensor arranged at the discharge port, and the input device, the displacement sensor, the first flow sensor, and the second flow sensor are all connected to the controller signal.

[0013] Preferably, a first valve is provided at the discharge port, and a third opening pressure of the first valve is smaller than the second force; the one-way sealing unit is arranged close to the input port, or the one-way sealing unit is arranged close to the output port.

[0014] In addition, the present invention also discloses a hydraulic system, which includes the unloading valve.

[0015] Compared with the prior art, the present invention has achieved the following technical effects: In the present invention, the unloading valve is arranged close to the actuator, and the unloading valve comprises a valve body, a first valve cavity is arranged in the valve body, an input port, an output port and a discharge port which are connected with the first valve cavity are arranged on the valve body, the input port is connected with the input device, the output port is connected with the actuator, the discharge port is connected with the working medium storage device, and the first valve core is located in the first valve cavity; a one-way sealing unit is located in the first valve cavity, and the one-way sealing unit is used to prevent the working medium from flowing from the output port and the discharge port to the input port; when the unloading valve is in a closed state, the one-way sealing unit blocks the flow path between the input port and the output port, and when the unloading valve is switched from a closed state to an open state, the working medium which enters the first valve cavity from the input port applies a first force to the first valve core, and when the first force is greater than a first opening pressure of the one-way sealing unit, the one-way sealing unit releases the blockage of the flow path, and the input port is connected with the output port.

[0016] It should be noted that when the hydraulic system in the prior art is depressurized, the working medium at the actuator needs to be completely returned to the input device in order to achieve complete pressure relief at the actuator, that is, the hydraulic system. If the working medium in the actuator only enters the pipeline between the actuator and the input device, the pressure in the actuator cannot be completely released, and the working medium in the pipeline will still interfere with the action of the actuator. However, since the pipeline between the actuator and the input device is long (the pipeline can reach several thousand meters or even tens of thousands of meters), the hydraulic system in the prior art requires a long time to relieve pressure, which makes it difficult to meet the emergency pressure relief needs of the hydraulic system. In addition, due to the long pressure relief time, the actuator may not be able to stop in time, causing safety accidents around the actuator.

[0017] ① In the present invention, the distance between the unloading valve and the actuator is smaller than the distance between the actuator and the input device. Obviously, this shortens the path length that the working medium needs to flow through when releasing pressure, reduces the time required for pressure relief of the hydraulic system using the unloading valve in the present invention, and reduces the probability of safety accidents caused by untimely pressure relief at the actuator.

[0018] ② In the present invention, the unloading valve is arranged close to the actuator (the unloading valve is arranged close to the actuator can be understood as the unloading valve is arranged adjacent to or close to the actuator), which shortens the distance between the actuator and the unloading valve, further reduces the length of the path that the working medium needs to flow through when the pressure is released, and further reduces the probability of safety accidents caused by untimely pressure release at the actuator.

[0019] ③ Since the input port and the output port are disconnected when the unloading valve in the present invention is in the pressure relief state, this avoids the problem that the working medium flows to the input port, resulting in a decrease in the pressure of the working medium discharged from the relief port and a slow flow rate. This allows the working medium in the actuator to flow to the unloading valve at a higher flow rate and be discharged from the unloading valve, thereby further accelerating the pressure relief efficiency of the hydraulic system using the unloading valve in the present invention, and greatly reducing the probability of safety accidents around the actuator caused by untimely pressure relief of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the principle of the unloading valve; Figure 2 It is a cross-sectional view of the unloading valve; Figure 3 It is a structural schematic diagram of the valve body; Figure 4is a structural schematic diagram of the first valve core; Figure 5 It is a schematic diagram of the unloading valve being in a closed state; Figure 6 It is a schematic diagram of the unloading valve in working state; Figure 7 It is a schematic diagram of the unloading valve in the pressure relief state; Among them, 1. valve body; 2. valve cover; 3. guide rail; 4. limiter; 5. first valve core; 6. sleeve; 7. first sealing member; 8. first sealing unit; 9. support ring; 10. second sealing assembly; 11. reset member; 12. input port; 13. output port; 14. discharge port; 15. inlet; 16. pressure relief hole. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 to Figure 7As shown, the present invention discloses an unloading valve, which is arranged near an actuator, and comprises: a valve body 1, a first valve cavity is arranged in the valve body 1, an input port 12, an output port 13 and a discharge port 14 which are connected to the first valve cavity are arranged on the valve body 1, the input port 12 is disconnected from the discharge port 14, the input port 12 is connected to an input device, the output port 13 is connected to the actuator, the discharge port 14 is connected to a working medium storage device, and the distance between the actuator and the unloading valve is smaller than the distance between the actuator and the input device; a first valve core 5, the first valve core 5 is located in the first valve cavity; a one-way sealing unit, the one-way sealing unit is located in the first valve cavity, and the one-way sealing unit is used to prevent the working medium from flowing out from the output port 13 and the discharge port 14 To the input port 12; wherein the unloading valve has an open state, a closed state and a pressure relief state. When the unloading valve is in the closed state, the one-way sealing unit blocks the flow path between the input port 12 and the output port 13; when the unloading valve is switched from the closed state to the open state, the working medium entering the first valve chamber from the input port 12 applies a first force to the first valve core 5. When the first force is greater than the first opening pressure of the one-way sealing unit, the one-way sealing unit releases the blockage of the flow path, and the input port 12 is connected to the output port 13; when the unloading valve is switched from the open state to the pressure relief state, the first force is less than the first opening pressure, the input port 12 is disconnected from the output port 13, and the output port 13 is connected to the discharge port 14.

[0025] It should be noted that when the hydraulic system in the prior art is depressurized, the working medium at the actuator needs to be completely returned to the input device in order to achieve complete pressure relief at the actuator, that is, the hydraulic system. If the working medium in the actuator only enters the pipeline between the actuator and the input device, the pressure in the actuator cannot be completely released, and the working medium in the pipeline will still interfere with the action of the actuator. However, since the pipeline between the actuator and the input device is long (the pipeline can be several thousand meters or even tens of thousands of meters), the hydraulic system in the prior art requires a long time to depressurize, which makes it difficult to meet the emergency pressure relief needs of the hydraulic system. In addition, due to the long pressure relief time, the actuator may not be able to stop in time, causing safety accidents around the actuator.

[0026] ① In the present invention, the distance between the unloading valve and the actuator is smaller than the distance between the actuator and the input device. Obviously, this shortens the path length that the working medium needs to flow through when releasing pressure, reduces the time required for pressure relief of the hydraulic system using the unloading valve in the present invention, and reduces the probability of safety accidents caused by untimely pressure relief at the actuator.

[0027] ② In the present invention, the unloading valve is arranged close to the actuator (the unloading valve is arranged close to the actuator can be understood as the unloading valve is arranged adjacent to or close to the actuator), which shortens the distance between the actuator and the unloading valve, further reduces the length of the path that the working medium needs to flow through when the pressure is released, and further reduces the probability of safety accidents caused by untimely pressure release at the actuator.

[0028] ③ Since the input port 12 is disconnected from the output port 13 when the unloading valve in the present invention is in a pressure relief state, this avoids the problem that the working medium flows to the input port 12, resulting in a decrease in the pressure of the working medium discharged from the discharge port 14 and a slow flow rate. This allows the working medium in the actuator to flow to the unloading valve at a higher flow rate and be discharged from the unloading valve, thereby further accelerating the pressure relief efficiency of the hydraulic system using the unloading valve in the present invention, and greatly reducing the probability of safety accidents around the actuator caused by untimely pressure relief of the hydraulic system.

[0029] Among them, the input device can be a structure such as a hydraulic pump that can inject working medium into the input port 12; the actuator can be a device such as a hydraulic cylinder that can use the hydraulic energy of the working medium to work; the working medium can be hydraulic oil or other medium that can be used by the input device and the actuator; the working medium storage device refers to a structure that can store the working medium, such as a storage tank, or, if the surrounding environment allows and the working medium will not cause great harm to the surrounding environment, the working medium can also be discharged nearby and on the spot. At this time, the discharge port 14 is connected to the external environment, and the external environment is equivalent to the working medium storage device. At this time, the working medium flows out of the discharge port 14 to complete the pressure relief, thereby further shortening the path for the working medium to be ventilated, and shortening the pressure relief time of the hydraulic system using the pressure relief valve in the present invention. The unloading valve can be located between the actuator and the input device, or it can not be located between the actuator and the input device, as long as the setting of the unloading valve meets the condition that "the distance between the unloading valve and the actuator is less than the distance between the actuator and the input device". The setting of the one-way sealing unit ensures that when the unloading valve is in a pressure relief state, the working medium will not flow from the output port 13 to the input port 12, and the working medium entering the first valve chamber from the output port 13 can be completely discharged from the discharge port 14, so that the working medium can be discharged from the discharge port 14 at a higher speed.

[0030] The input port 12 and the output port 13 in this article are connected, which means that the working medium can flow from the input device through the input port 12 and the output port 13 to the actuator. If a circuit is broken at any point in the flow path between the input device and the actuator, the input port 12 and the output port 13 cannot be said to be connected; similarly, if a circuit is broken at any point in the flow path between the working medium storage device and the actuator, the output port 13 and the discharge port 14 cannot be said to be connected.

[0031] Whether the output port 13 and the discharge port 14 are connected or not can be determined by the second force of the working medium entering the first valve cavity from the output port 13, and can also be switched by the operator or the controller. For example, a first valve can be set at the output port 13, and the third opening pressure of the first valve is less than the second force. The first valve can be opened by the operator or the controller connected to the signal of the first valve when the unloading valve is in the pressure relief state. Alternatively, the first valve can be set as a relief valve. After the second force reaches the opening pressure of the first valve, the first valve opens, and the output port 13 and the discharge port 14 are connected. Alternatively, the first valve can be set as a one-way valve that can prevent the working medium from flowing from the discharge port 14 to the output port 13. The one-way valve opens after the second force reaches the opening pressure of the one-way valve, so that the output port 13 and the discharge port 14 are connected.

[0032] Alternatively, the switching of the connection and disconnection between the discharge port 14 and the output port 13 may not adopt the above-mentioned structure. In this case, the first valve core 5 is slidably connected to the first valve chamber in the first direction; when the unloading valve is switched from a closed state to an open state, and the first force is greater than the second opening pressure, the first valve core 5 moves along the first direction, and the second opening pressure is less than the first opening pressure; when the unloading valve is switched from an open state to a pressure relief state, the second force causes the first valve core 5 to move in the second direction until the first valve core 5 reaches the pressure relief position, and the output port 13 is connected to the discharge port 14; wherein, the first direction is set from the input port 12 toward the output port 13, and the first direction is opposite to the second direction.

[0033] The first direction can be the axial direction, radial direction, or other directions of the valve body 1, as long as the setting of the first direction can meet the condition that "when the second force causes the first valve core 5 to move in the second direction, the first valve core 5 reaches the pressure relief position, the output port 13 is connected to the discharge port 14".

[0034] In the present invention, the one-way sealing unit is arranged on the flow path between the input port 12 and the output port 13, and the flow path is the area of ​​the first valve cavity when the input port 12 and the output port 13 are connected; specifically, the one-way sealing unit is arranged close to the input port 12, or the one-way sealing unit is arranged close to the output port 13; it should be noted that when the first valve core 5 can move along the first direction under the first force, the one-way sealing unit needs to be arranged to avoid the first valve core 5, which means that the one-way sealing unit blocks the flow path before the first force is less than the first opening pressure, and the first valve core 5 can move in the first direction when the first force is greater than the second opening pressure. Both functions can be smoothly realized.

[0035] The first valve core 5 has a second valve cavity inside, and the first valve core 5 is provided with an inlet 15 and an outlet both connected to the first valve cavity and the second valve cavity, the inlet 15 and the outlet are arranged in sequence along the first direction, and a one-way sealing unit is provided in the first valve cavity, and the one-way sealing unit is used to block the flow channel between the inlet 15 and the outlet; wherein, Figure 2 , Figure 4~Figure 7 As shown, the one-way sealing unit includes a reset member 11 and a first sealing member which are sequentially arranged along the second direction and located on the flow channel. The reset member 11 applies a first opening pressure to the first sealing member, and the first opening pressure causes the first sealing member to block the flow channel. The first sealing member forms a sealing pair with the first valve core 5 or a sealing seat arranged in the first valve core 5; the inlet 15 can be arranged at the end of the first valve core 5, or it can also be arranged at the side of the first valve core 5. When the inlet 15 is arranged at the side of the first valve core 5, there must be a gap between the area where the inlet 15 is arranged on the first valve core 5 and the valve body 1 to facilitate the inflow of the working medium; similarly, the outlet can be arranged at the end of the first valve core 5, or it can also be arranged at the side of the first valve core 5. When the outlet is arranged at the side of the first valve core 5, there must be a gap between the area where the outlet is arranged on the first valve core 5 and the valve body 1 to facilitate the inflow of the working medium and flow to the output port 13 or the discharge port 14. When the outlet is arranged along the circumference of the guide rail 3 or the first valve core 5, the outlet can specifically be the pressure relief hole 16. At this time, there is a gap between the first valve core 5 or the guide rail 3 and the valve body 1, so that when the unloading valve is in the pressure relief state, the working medium can flow out of the pressure relief hole 16 and flow to the discharge port 14. When the unloading valve is in the open state, the working medium can flow out of the pressure relief hole 16 and flow to the output port 13.

[0036] The first sealing member may be a sealing ball, a sealing plate, a sealing block or the like that can cooperate with the first valve core 5 to achieve a structure for blocking the flow channel when the first force is less than the first opening pressure. The reset member 11 may be a spring or the like that can apply the first opening pressure to the first sealing member.

[0037] Alternatively, the one-way sealing unit includes a one-way valve, which is used to seal the flow channel; alternatively, the one-way sealing unit includes a second sealing member located on the flow channel and arranged in sequence along a second direction, the second sealing member and the first valve core 5 or a sealing seat arranged in the first valve core 5 form a sealing pair, when the first force is less than the first opening pressure, the second sealing member maintains the sealing of the flow channel, the first direction is set from top to bottom, the first opening pressure is the gravity of the second sealing member, similarly, the second sealing member may specifically be a sealing ball, or a sealing plate, or a sealing block and other structures that cooperate with the first valve core 5 to achieve a structure for sealing the flow channel when the first force is less than the first opening pressure.

[0038] Alternatively, the one-way sealing unit includes a third sealing member arranged on the flow channel. When the first force is less than the first opening pressure, the third sealing member blocks the flow channel. The third sealing member forms a sealing pair with the first valve core 5 or a sealing seat arranged in the first valve core 5, thereby achieving sealing of the flow channel. The third sealing member can specifically be an elastic diaphragm. The elastic diaphragm has a force in the second direction, namely the first opening pressure, which enables the elastic diaphragm to block the flow channel. When the first force is greater than the first opening pressure, the elastic diaphragm deforms in the first direction, and the elastic diaphragm releases the blockage of the flow channel. When the elastic diaphragm is arranged at the inlet 15, the elastic diaphragm can form a sealing pair with the first valve core 5. When the elastic diaphragm is arranged between the inlet 15 and the outlet, or is arranged close to the outlet, a sealing seat that cooperates with the elastic diaphragm to form a sealing pair needs to be arranged in the first valve core 5, such as a protrusion extending inward.

[0039] The first opening pressure may be understood as the force of the one-way sealing unit to block the flow channel, and the second opening pressure may be understood as the friction resistance between the first valve core 5 and the valve body 1 .

[0040] Furthermore, in the present invention, when the unloading valve is in a pressure relief state, the output port 13 is communicated with the discharge port 14 through the first valve cavity. At this time, when the first valve core 5 moves to the pressure relief position, the first valve core 5 releases the blockage of the discharge port 14, and the output port 13 can be directly communicated with the discharge port 14 through the first valve cavity, or, when the first valve core 5 moves to the pressure relief position, the output port 13 is communicated with the discharge port 14 through the outlet on the first valve core 5.

[0041] In addition, the unloading valve includes a first sealing component and a second sealing component 10, wherein the first sealing component is disposed between the area of ​​the valve body 1 close to the output port 13 and the first valve core 5, and the second sealing component 10 is disposed between the area of ​​the valve body 1 close to the input port 12 and the first valve core 5, and the first sealing component 10 can respectively ensure the sealing at the input port 12 and the output port 13, thereby reducing or even avoiding the leakage problem of the unloading valve. The first sealing component and the second sealing component 10 can be specifically a plurality of sealing rings, or can also be a seal formed between the first valve core 5 and the first valve cavity structure itself, and a seal formed between the first valve core 5 and the output port 13.

[0042] like Figure 2 , Figure 4~Figure 7As shown, the first sealing assembly includes a first sealing surface provided at one end of the first valve core 5 facing the output port 13, and a second sealing surface provided at one end of the valve body 1 facing the input port 12. When the unloading valve is in an open state, the first sealing surface and the second sealing member form a sealing pair; the first sealing assembly also includes a first sealing unit 8 provided between the valve cover 2 and the valve body 1, and the first sealing unit 8 can be specifically an O-ring. The first sealing assembly includes a sealing ring such as an O-ring provided between the first valve core 5 and the valve body 1, and a support ring 9 provided on one side of the sealing ring close to the output port 13.

[0043] The unloading valve in the present invention further includes a displacement sensor disposed on the first valve core 5, a first flow sensor disposed at the output port 13, a second flow sensor disposed at the discharge port 14, and a controller, and the input device, the displacement sensor, the first flow sensor, and the second flow sensor are all connected to the controller signal. When the controller determines that the unloading valve has not switched to the pressure relief state or the open state in time, and the output port 13 and the input port 12 are not connected or closed, and the output port 13 and the discharge port 14 are not connected or closed, the controller increases, decreases, or closes the working medium input into the first valve core 5 by the input device, so as to adjust the unloading valve to the desired state and ensure the smooth operation of the unloading valve, based on the feedback of the displacement sensor, the first flow sensor, and the second flow sensor.

[0044] like Figure 1 to Figure 7 As shown, the valve body 1 in the present invention is of a cylindrical structure, and the outer side of the end of the valve body 1 is chamfered by 45°, which reduces the rapid shape change and stress concentration problem at the end of the valve body 1, and effectively avoids the collision damage of the end of the valve body 1 during use and assembly, as well as mechanical damage to the operator. The valve body 1 is provided with an input device connection area near the input port 12, and the input device connection area can be specifically an internal thread in the valve body 1. The valve body 1 is provided with an actuator connection area near the output port 13, and the actuator connection area can be specifically an internal thread in the valve body 1. The actuator connection area can be threadedly connected to the valve cover 2, and connected to the actuator through the valve cover 2. The valve body 1 is provided with a recovery pipe connection area near the discharge port 14, and is connected to the working medium storage device through the recovery pipe connection area. The recovery pipe connection area can be specifically an internal thread in the valve body 1; and the outer ends of the above-mentioned internal threads are chamfered by 45°, which is convenient for installation and prevents damage to the end threads.

[0045] The present invention sets a second sealing surface facing the input port 12 at the lower part of the valve cover 2, or directly at a position of the valve body 1 near the output port 13. The second sealing surface can be a boss. The first sealing surface and the second sealing surface can form a metal-to-metal seal, thereby improving the overall sealing performance of the unloading valve. In addition, the present invention further sets a limiter 4 on the first sealing surface. The limiter 4 is located on the side of the first sealing surface close to the output port 13. The limiter can limit the movement of the first valve core 5 to prevent the first valve core 5 and the valve cover 2 from being damaged by collision. The limiter 4 can be a structure with a shock absorbing effect, such as a rubber ring. At this time, the first sealing component is located between the valve cover 2 and the valve body 1. Figure 2 , Figure 4~Figure 7 As shown, the sleeve 6 is located between the side of the guide rail 3 and the bottom of the first valve core 5 , and the sleeve 6 allows a certain gap to exist between the bottom of the guide rail 3 and the bottom of the first valve core 5 , thereby providing sufficient space for the movement of the first sealing member 7 .

[0046] like Figure 2 , Figure 4~Figure 7 As shown, one end of the first valve core 5 near the output port 13 is threadedly connected to the guide rail 3, and the end of the guide rail 3 near the output port 13 is provided with an outlet, and the end of the guide rail 3 facing the discharge port 14 is provided with a plurality of pressure relief holes 16, and the pressure relief holes 16 are evenly arranged along the circumference of the guide rail 3. Alternatively, the guide rail 3 and the first valve core 5 can also be arranged as one body, but it is necessary to ensure that a gap is left between the first valve core 5 and the guide rail 3 to insert the limit member 4.

[0047] In addition, the present invention also discloses a hydraulic system, which includes the above-mentioned unloading valve. The hydraulic system is specifically a device that can apply the above-mentioned unloading valve.

[0048] The "and / or" in this article refers to the text content before "and / or", and the text content after "and / or" can exist at the same time or separately; for example, A and / or B includes the three situations that only A or B exists, and A and B exist at the same time.

[0049] The present invention discloses multiple technical solutions, but does not provide any contrary technical inspiration.

[0050] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An unloading valve, characterized in that: The unloading valve is arranged close to the actuator, and the unloading valve comprises: A valve body, wherein a first valve cavity is provided in the valve body, an input port, an output port and a discharge port connected to the first valve cavity are provided on the valve body, the input port is disconnected from the discharge port, the input port is connected to an input device, the output port is connected to the actuator, the discharge port is connected to a working medium storage device, and a distance between the actuator and the unloading valve is smaller than a distance between the actuator and the input device; a first valve core, the first valve core being located in the first valve cavity; a one-way sealing unit, the one-way sealing unit being located in the first valve chamber and being used to prevent the working medium from flowing from the output port and the discharge port to the input port; Wherein, the unloading valve has an open state, a closed state and a pressure relief state, and when the unloading valve is in the closed state, the one-way sealing unit blocks the flow path between the input port and the output port; When the unloading valve is switched from the closed state to the open state, the working medium entering the first valve cavity from the input port exerts a first force on the first valve core, and when the first force is greater than the first opening pressure of the one-way sealing unit, the one-way sealing unit releases the blockage of the flow path, and the input port is connected to the output port; When the unloading valve is switched from the open state to the pressure relief state, the first force is smaller than the first opening pressure, the input port is disconnected from the output port, and the output port is connected to the relief port.

2. The unloading valve according to claim 1, characterized in that: When the unloading valve switches from the open state to the pressure relief state, the working medium entering the first valve cavity from the output port exerts a second force on the first valve core, and the second force causes the output port to communicate with the relief port.

3. The unloading valve according to claim 2, characterized in that: The first valve core is slidably connected to the first valve cavity in a first direction; When the unloading valve is switched from the closed state to the open state, and the first force is greater than the second opening pressure, the first valve core moves along the first direction, and the second opening pressure is less than the first opening pressure; when the unloading valve is switched from the open state to the pressure relief state, the second force causes the first valve core to move in the second direction until the first valve core reaches the pressure relief position, and the output port is connected to the discharge port; Wherein, the first direction is set from the input port toward the output port, and the first direction is opposite to the second direction.

4. The unloading valve according to claim 3, characterized in that: The first valve core has a second valve cavity therein, the first valve core is provided with an inlet and an outlet both connected to the first valve cavity and the second valve cavity, the first valve cavity is provided with the one-way sealing unit, the one-way sealing unit is used to block the flow channel between the inlet and the outlet; Wherein, the one-way sealing unit comprises a reset member and a first sealing member which are sequentially arranged along the second direction and located on the flow channel, the reset member applies the first opening pressure to the first sealing member, and the first opening pressure causes the first sealing member to block the flow channel; Alternatively, the one-way sealing unit comprises a one-way valve, and the one-way valve is used to block the flow channel; Alternatively, the one-way sealing unit includes second sealing members located on the flow channel and arranged in sequence along the second direction, when the first force is less than the first opening pressure, the second sealing members keep blocking the flow channel, the first direction is arranged from top to bottom, and the first opening pressure is the weight of the second sealing members; Alternatively, the one-way sealing unit includes a third sealing member disposed on the flow channel, and when the first force is less than the first opening pressure, the third sealing member keeps blocking the flow channel.

5. The unloading valve according to claim 1, characterized in that: When the unloading valve is in the pressure relief state, the output port is communicated with the discharge port through the first valve chamber, or the output port is communicated with the discharge port through the first valve core.

6. The unloading valve according to claim 1, characterized in that: The unloading valve includes a first sealing component and a second sealing component. The first sealing component is arranged between a region of the valve body close to the output port and the first valve core. The second sealing component is arranged between a region of the valve body close to the input port and the first valve core.

7. The unloading valve according to claim 6, characterized in that: The first sealing assembly includes a first sealing surface provided at one end of the first valve core facing the output port, and a second sealing surface provided at the valve body facing the input port. When the unloading valve is in the open state, the first sealing surface and the second sealing surface form a sealing pair.

8. The unloading valve according to claim 2, characterized in that: The unloading valve also includes a controller, a displacement sensor arranged on the first valve core, a first flow sensor arranged at the output port, and a second flow sensor arranged at the discharge port. The input device, the displacement sensor, the first flow sensor, and the second flow sensor are all connected to the controller signal.

9. The unloading valve according to claim 2, characterized in that: A first valve is provided at the discharge port, and a third opening pressure of the first valve is less than the second force; the one-way sealing unit is arranged close to the input port, or the one-way sealing unit is arranged close to the output port.

10. A hydraulic system, characterized in that: The hydraulic system comprises the unloading valve according to any one of claims 1-9.

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