Transition function hydraulic valve

Abstract

The utility model relates to a hydraulic technology field, concretely relates to a transition function hydraulic valve, a transition function hydraulic valve, include: valve body, be provided with pressure oil port, oil return and at least one work oil port on the valve body, valve core, the valve core is assembled in the valve body, and the on-off of sliding control oil port, when the valve core is in the middle position, the work oil port is disconnected with pressure oil port, oil return, the valve core is from the middle position and is moved to the work position that work oil port and pressure oil port are communicated between the first transition position and the second transition position that form in proper order, when the valve core is in the first transition position, pressure oil port and the throttling communication between the work oil port, when the valve core is in the second transition position, pressure oil port and the throttling communication between the work oil port, simultaneously, pressure oil port still and the throttling communication between oil return, solved the transition function hydraulic valve in the prior art, will delay work oil port response time, cause the technical problem of action lag.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic technology, specifically to a transitional function hydraulic valve. Background Technology

[0002] Currently, hydraulic systems and components are widely used in various mobile machinery, construction machinery, and other heavy equipment. Generally, directional control valves switch directly from the neutral position to the working position. After the directional control valve switches from the neutral position to the working position, the pressurized oil directly enters the working port. The oil pressure at port P is rapidly transmitted to the working port, causing a sudden impact. This impact generates vibration and noise, and it can also cause cavitation, affecting the lifespan of components (pipelines, valves, pumps, cylinders). Furthermore, this impact can cause jerking during load startup.

[0003] To address the aforementioned impact problem, application number CN202111173414.0 provides a transitional function hydraulic valve, comprising a valve body and a valve core. The valve body is provided with a pressure port, a return port, and at least one working port. The valve core is slidably assembled within the valve body, and the sliding of the valve core controls the on / off connection between the pressure port, the working port, and the return port. To allow for pressure relief before establishing a connection between the pressure port and the working port, the valve core in this embodiment is equipped with a pressure relief oil circuit. According to one embodiment of the present invention, the pressure relief oil circuit includes an internal oil passage within the valve core and an inlet and an outlet on the valve core. The inlet and outlet are respectively connected to the internal oil passage. When the valve core is in the neutral position, the pressure port is sequentially connected to the inlet and the internal oil passage, while the outlet and the return port are disconnected. At this time, the pressure oil establishes oil pressure in the internal oil passage. During operation, pressure relief is first performed, that is, the valve core moves in a certain direction to connect the outlet and the return port, while maintaining the connection between the pressure port and the inlet and the internal oil passage. In this way, the pressure port can sequentially return oil and relieve pressure through the inlet, the internal oil passage, the outlet, and the return port. Then, the valve core continues to move in the same direction, connecting the pressure port to the working port, while disconnecting the outlet and the return port. In this way, the pressure port supplies oil to the load through the working port. As can be seen from the above, in this embodiment, a transition position is also formed during the process of the valve core sliding from the neutral position to the working position. When the valve core is in the transition position, the pressure oil in the pressure port is at least partially depressurized through the pressure relief oil circuit.

[0004] The aforementioned transitional hydraulic valve, by first pressurizing the pressure port and then partially depressurizing it before connecting it to the working port, achieves high pressure at the neutral position and reduces the impact of the hydraulic fluid on the working port during rapid valve core switching. This reduces noise, extends the lifespan of components (pipelines, valves, pumps, cylinders), and ensures smooth operation of the load without jerking. However, this method of depressurizing the pressure oil before connecting it to the working port delays the response time of the working port, causing a lag in action. Utility Model Content

[0005] To address the technical problem of delayed response time and sluggish action caused by existing transition function hydraulic valves, this invention provides a transition function hydraulic valve that solves the aforementioned technical problem.

[0006] To solve the above-mentioned technical problems, this utility model provides a transitional function hydraulic valve, comprising:

[0007] The valve body is provided with a pressure oil port, a return oil port and at least one working oil port;

[0008] The valve core is slidably assembled in the valve body and slides to control the on / off state between the oil ports.

[0009] When the valve core is in the neutral position, the working oil port is disconnected from both the pressure oil port and the return oil port. Between the valve core moving from the neutral position to the working position where the working oil port and pressure oil port are connected, a first transition position and a second transition position are formed sequentially. When the valve core is in the first transition position, the pressure oil port and the working oil port are throttled and connected. When the valve core is in the second transition position, the pressure oil port and the working oil port are throttled and connected, and simultaneously, the pressure oil port is also throttled and connected to the return oil port.

[0010] According to one embodiment of the present invention, there are two working oil ports. When the valve core is in the first transition position, the pressure oil port is throttled and connected to one working oil port, and the other working oil port is throttled and connected to the return oil port.

[0011] According to one embodiment of the present invention, when the valve core is in the second transition position, the pressure oil port is throttled and connected to a working oil port, and the pressure oil port is throttled and connected to the return oil port through another working oil port.

[0012] According to one embodiment of the present invention, a flow groove is formed on the valve core, and the flow groove is correspondingly arranged with the working oil port. In the working position, the working oil port flows through the flow groove to the pressure oil port or the return oil port over a large area.

[0013] According to one embodiment of the present invention, an oil inlet throttling groove and an oil outlet throttling groove are formed on the outer peripheral surface of the valve core. The pressure oil port is throttled and connected to the working oil port through the oil inlet throttling groove, and the working oil port is throttled and connected to the return oil port through the oil outlet throttling groove.

[0014] According to one embodiment of the present invention, the oil inlet throttling groove extends from the opening of the flow channel toward the pressure oil port, and the oil outlet throttling groove extends from the opening of the flow channel toward the return oil port.

[0015] According to one embodiment of the present invention, a pressure relief groove is formed on the outer peripheral surface of the valve core. When the valve core is in the second transition position, the pressure oil port is connected to another working oil port through the pressure relief groove, and the other working oil port is throttled and connected to the return oil port.

[0016] According to one embodiment of the present invention, the pressure relief groove is located on the side of the flow channel near the pressure oil port, and the axial length of the flow channel is greater than the minimum distance from the pressure oil port to the corresponding working oil port.

[0017] According to one embodiment of the present invention, the pressure relief groove can be configured as a plurality of grooves, and the pressure relief grooves for the same working oil port are arranged circumferentially.

[0018] According to one embodiment of the present invention, each working oil port is provided with a pressure oil port and a return oil port on both axial sides. The valve core controls the connection and disconnection between the working oil port and the adjacent pressure oil port and return oil port. The two pressure oil ports are located inside the two working oil ports and are connected, and the two return oil ports are located outside the two working oil ports and are connected.

[0019] Based on the above technical solution, the technical effects that this utility model can achieve are as follows:

[0020] This utility model discloses a transitional hydraulic valve. By setting a first transition position and a second transition position, in the first transition position, the pressure port and the working port are throttled and connected; in the second transition position, the pressure port and the working port are throttled and connected, and the pressure port is also throttled and connected to the return port, allowing for partial pressure relief. That is, between the valve core moving from the neutral position to the working position where the working port and the pressure port are connected, the pressure port can first be throttled and connected to the working port, then partially relieved, and finally connected to the working port. This eliminates the problem of delayed response time of the working port caused by existing pressure relief technology.

[0021] The hydraulic valve of this invention features a transition function, with the first and second transition positions located between the neutral and working positions. The pressure relief oil circuit can be opened and closed simply by the relative sliding of the existing valve body and valve core. The unloading principle is simpler, eliminating the need for redundant parts to control the opening and closing of the pressure relief channel.

[0022] In the first transition position of the hydraulic valve of this utility model, the pressure oil port is throttled and connected to one working oil port, and the other working oil port is throttled and connected to the return oil port, which slows down the speed at which the pressure oil is transmitted to the working oil port and avoids a sudden impact on the working oil port.

[0023] The transitional hydraulic valve of this utility model has a pressure relief groove located on the outer surface of the valve core, eliminating the need for machining the internal holes of the valve core and greatly reducing the machining difficulty of the valve core.

[0024] The transitional hydraulic valve of this utility model can have its first transition position and second transition position set for one working oil port or for both working oil ports. Similarly, the inlet throttling groove, outlet throttling groove, and pressure relief groove can also be set for one working oil port or for two working oil ports. The shape and number of pressure relief grooves can be adjusted as needed. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the transitional function hydraulic valve of this utility model in the neutral position.

[0026] Figure 2 This is a schematic diagram of the valve core structure;

[0027] Figure 3 This is a cross-sectional view of the valve core;

[0028] Figure 4 Hydraulic schematic diagram of a transitional hydraulic valve;

[0029] Figure 5 This is a diagram showing the state of the valve core in the first transition position when it slides towards the first working position.

[0030] Figure 6 This is a diagram showing the valve core in the second transition position when it slides towards the first working position.

[0031] Figure 7 This is a diagram showing the valve core in its first working position.

[0032] Figure 8 This is a diagram showing the state of the valve core in the first transition position when it slides towards the second working position.

[0033] Figure 9 This is a diagram showing the valve core in the second transition position when it slides towards the second working position.

[0034] Figure 10 This is a diagram showing the valve core in its second working position.

[0035] In the figure: 1-valve body; 2-valve core; 211-first flow channel; 212-second flow channel; 221-first oil inlet throttling channel; 222-second oil inlet throttling channel; 231-first oil outlet throttling channel; 232-second oil outlet throttling channel; 241-first pressure relief channel; 242-second pressure relief channel. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0039] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0040] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0041] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0042] like Figure 1-10As shown, this embodiment provides a transitional hydraulic valve, including a valve body 1 and a valve core 2. The valve body 1 is provided with a pressure port P, a return port T, and at least one working port. The valve core 2 is slidably assembled within the valve body 1, controlling the connection and disconnection between the ports. When the valve core 2 is in the neutral position, the working port is disconnected from both the pressure port P and the return port T. A first transition position and a second transition position are sequentially formed between the valve core 2 moving from the neutral position to the working position where the working port connects with the pressure port P. When the valve core 2 is in the first transition position, the pressure port P and the working port are throttled and connected. When the valve core 2 is in the second transition position, the pressure port P and the working port are throttled and connected, and simultaneously, the pressure port P is also throttled and connected to the return port T, achieving partial pressure relief. This embodiment of the transitional hydraulic valve adopts a working method where the pressure port first throttles and connects with the working port, then partially relieves pressure, and then connects with the working port again. This avoids both sudden high-pressure impacts and delayed response and lag issues.

[0043] like Figure 1 As shown, the valve body 1 has a mounting hole for assembling the valve core 2. The valve body 1 also has a pressure port P, a return port T, and at least one working port. The pressure port P, the return port T, and the working port are all connected to the mounting hole where the valve core 2 is located.

[0044] As a preferred technical solution in this embodiment, there are two working oil ports, namely working oil port A and working oil port B.

[0045] As a preferred embodiment, each working port is provided with a pressure port P and a return port T on both axial sides. The valve core 2 slides to control the connection and disconnection between the working port and the adjacent pressure port P and return port T. Specifically, for working port A, a pressure port P and a return port T are respectively provided on both axial sides of working port A; for working port B, a pressure port P and a return port T are respectively provided on both axial sides of working port B. Specifically, there can be two pressure ports P and two return ports T. The two pressure ports P are located inside the two working ports and are connected for introducing pressure oil; the two return ports T are located outside the two working ports and are connected for returning oil. Preferably, the two pressure ports P, the two return ports T, and the two working ports are arranged symmetrically.

[0046] Valve core 2 is slidably assembled inside valve body 1, such as Figure 1-3 As shown, the valve core 2 has a columnar structure and a flow groove is formed on the valve core 2. The flow groove is set for the working oil port. Specifically, a first flow groove 211 is formed for the working oil port A and a second flow groove 212 is formed for the working oil port B. In the working position, the working oil port A is connected to the pressure oil port P or the return oil port T through the first flow groove 211; the working oil port B is connected to the return oil port T or the pressure oil port P through the second flow groove 212.

[0047] like Figure 1-2 As shown, an oil inlet throttling groove is formed on the outer circumferential surface of the valve core 2, and the pressure port P is throttled and connected to the adjacent working port through the oil inlet throttling groove. Specifically, the valve core 2 is provided with a first oil inlet throttling groove 221, and the pressure port P near the working port A is throttled and connected to the working port A through the first oil inlet throttling groove 221; the valve core 2 is provided with a second oil inlet throttling groove 222, and the pressure port P near the working port B is throttled and connected to the working port B through the second oil inlet throttling groove 222.

[0048] As a preferred embodiment, the first oil inlet throttling groove 221 is connected to the first flow channel 211, and the first oil inlet throttling groove 221 extends from the opening of the first flow channel 211 toward the pressure oil port P near the working oil port A. The second oil inlet throttling groove 222 is connected to the second flow channel 212, and the second oil inlet throttling groove 222 extends from the opening of the second flow channel 212 toward the pressure oil port P near the working oil port B.

[0049] As a preferred technical solution in this embodiment, the shapes of the first oil inlet throttling groove 221 and the second oil inlet throttling groove 222 are not limited, as long as they can achieve the function of throttling oil inlet. In this embodiment, the first oil inlet throttling groove 221 and the second oil inlet throttling groove 222 are semi-circular throttling grooves.

[0050] As a preferred embodiment, the number of first oil inlet throttling grooves 221 and second oil inlet throttling grooves 222 is several. When there are at least two first oil inlet throttling grooves 221 and two second oil inlet throttling grooves 222, all first oil inlet throttling grooves 221 are distributed circumferentially, and all second oil inlet throttling grooves 222 are distributed circumferentially. Preferably, all first oil inlet throttling grooves 221 are evenly distributed circumferentially, and all second oil inlet throttling grooves 222 are evenly distributed circumferentially.

[0051] like Figure 1-2 As shown, an oil outlet throttling groove is formed on the outer circumferential surface of the valve core 2, and the working oil port is throttled and connected to the adjacent oil return port T through the oil outlet throttling groove. Specifically, the valve core 2 is provided with a first oil outlet throttling groove 231, and the working oil port A is throttled and connected to the adjacent oil return port T through the first oil outlet throttling groove 231; the valve core 2 is also provided with a second oil outlet throttling groove 232, and the working oil port B is throttled and connected to the adjacent oil return port T through the second oil outlet throttling groove 232.

[0052] As a preferred embodiment, the first oil outlet throttling groove 231 is connected to the first flow channel 211, and the first oil outlet throttling groove 231 extends from the opening of the first flow channel 211 toward the return oil port T near the working oil port A. The second oil outlet throttling groove 232 is connected to the second flow channel 212, and the second oil outlet throttling groove 232 extends from the opening of the second flow channel 212 toward the return oil port T near the working oil port B.

[0053] As a preferred technical solution in this embodiment, the shapes of the first oil outlet throttling groove 231 and the second oil outlet throttling groove 232 are not limited, as long as they can achieve the function of throttling oil flow. In this embodiment, the first oil outlet throttling groove 231 and the second oil outlet throttling groove 232 are elongated throttling grooves, and the first oil outlet throttling groove 231 and the second oil outlet throttling groove 232 extend parallel to the axis of the valve core 2.

[0054] As a preferred embodiment, the number of first oil outlet throttling grooves 231 and second oil outlet throttling grooves 232 is several. When there are at least two first oil outlet throttling grooves 231 and two second oil outlet throttling grooves 232, all first oil outlet throttling grooves 231 are distributed circumferentially, and all second oil outlet throttling grooves 232 are distributed circumferentially. Preferably, all first oil outlet throttling grooves 231 are evenly distributed circumferentially, and all second oil outlet throttling grooves 232 are evenly distributed circumferentially.

[0055] like Figure 1-2 As shown, a pressure relief groove is also formed on the valve core 2. In the second transition position, one pressure port P is connected to the adjacent working port through the inlet throttling groove; another pressure port P is connected to the adjacent working port through the pressure relief groove. The working port is also connected to the return port T through the outlet throttling groove, thereby realizing the throttling connection between the pressure port and one working port. At the same time, the pressure port P is also connected to the return port T through another working port, realizing partial pressure relief in the second transition position.

[0056] In this embodiment, the pressure relief groove includes a first pressure relief groove 241 and a second pressure relief groove 242. The first pressure relief groove 241 is provided for the working oil port A, and the pressure oil port P adjacent to the working oil port A can flow to the working oil port A through the first pressure relief groove 241. The second pressure relief groove 242 is provided for the working oil port B, and the pressure oil port P adjacent to the working oil port B can flow to the working oil port B through the second pressure relief groove 242.

[0057] As a preferred technical solution of this embodiment, the first pressure relief groove 241 is located on the side of the first flow channel 211 near the adjacent pressure oil port P, and the first pressure relief groove 241 and the first flow channel 211 are not connected; the second pressure relief groove 242 is located on the side of the second flow channel 212 near the adjacent pressure oil port P, and the second pressure relief groove 242 and the second flow channel 212 are not connected.

[0058] As a preferred technical solution in this embodiment, the shapes of the first pressure relief groove 241 and the second pressure relief groove 242 are not limited, as long as the oil at the pressure port P can be depressurized through the corresponding pressure relief groove to the corresponding working port. In this embodiment, the first pressure relief groove 241 and the second pressure relief groove 242 are elongated grooves, and both the first pressure relief groove 241 and the second pressure relief groove 242 extend parallel to the axis of the valve core 2, such as... Figure 3As shown, the cross-sectional shape of the first pressure relief groove 241 and the second pressure relief groove 242 is an inverted isosceles trapezoid.

[0059] As a preferred embodiment, the number of first pressure relief grooves 241 and second pressure relief grooves 242 is several. When there are at least two first pressure relief grooves 241 and two pressure relief grooves 242, all first pressure relief grooves 241 are distributed circumferentially, and all second pressure relief grooves 242 are distributed circumferentially. Preferably, all first pressure relief grooves 241 are evenly distributed circumferentially, and all second pressure relief grooves 242 are evenly distributed circumferentially.

[0060] As a preferred embodiment, the axial length of the flow channel is greater than the minimum distance from the adjacent pressure port P to the corresponding working port A. Specifically, the axial length of the first flow channel 241 is greater than the minimum distance from the adjacent pressure port P to the working port A. The first flow channel 241 needs to connect the adjacent pressure port P and the working port A, and its axial length must be greater than the minimum distance from the adjacent pressure port P to the working port A to ensure connectivity. The axial length of the second flow channel 242 is greater than the minimum distance from the adjacent pressure port P to the working port B. The second flow channel 242 needs to connect the adjacent pressure port P and the working port B, and its axial length must be greater than the minimum distance from the adjacent pressure port P to the working port B to ensure connectivity.

[0061] Based on the above structure, the working process of this embodiment is as follows:

[0062] (1) Working process of valve core 2 moving from the middle position to the left to the first working position

[0063] like Figure 1 , 4 As shown, when valve core 2 is in the neutral position, the pressure port P, return port T, working port A, and working port B are not connected.

[0064] like Figure 5 As shown, valve core 2 begins to move to the left to the first transition position. The pressure port P adjacent to the working port B is connected to the working port B via the second inlet throttling groove 222; the working port A is connected to the adjacent return port T via the first outlet throttling groove 231. At this time, it is possible to achieve throttling of oil inlet at the working port B and throttling of oil return at the working port A.

[0065] like Figure 6 As shown, valve core 2 moves further to the left to the second transition position. The pressure port P adjacent to working port B is connected to working port B via the second inlet throttling groove 222; the pressure port P adjacent to working port A is connected to working port A via the first pressure relief groove 241, and working port A is connected to the adjacent return port T via the first outlet throttling groove 231. At this time, throttling of oil inlet is achieved at working port B, and at the same time, throttling of oil return is achieved at pressure port P via working port A.

[0066] like Figure 7 As shown, valve core 2 moves further to the left until it is fully reversed. At this time, valve core 2 is in the first working position. Pressure port P, which is adjacent to working port B, is connected to working port B through the second flow channel 212; working port A is connected to the adjacent return port T through the first flow channel 211; the first pressure relief channel 241 is only connected to working port A and is not connected to the adjacent pressure port P, so the first pressure relief channel 241 no longer relieves pressure. At this time, oil can enter through working port B and return through working port A.

[0067] (2) The working process of valve core 2 moving from the middle position to the right to the second working position.

[0068] like Figure 1 , 4 As shown, when valve core 2 is in the neutral position, the pressure port P, return port T, working port A, and working port B are not connected.

[0069] like Figure 8 As shown, valve core 2 begins to move to the right to the first transition position. The pressure port P adjacent to the working port A is connected to the working port A via the first inlet throttling groove 221; the working port B is connected to the adjacent return port T via the second outlet throttling groove 232. At this time, it is possible to achieve throttling of the inlet oil at the working port A and throttling of the return oil at the working port B.

[0070] like Figure 9 As shown, valve core 2 moves further to the right to the second transition position. The pressure port P adjacent to working port A is connected to working port A via the first inlet throttling groove 221; the pressure port P adjacent to working port B is connected to working port B via the second pressure relief groove 242, and working port B is connected to the adjacent return port T via the second outlet throttling groove 232. At this time, throttling of oil inlet is achieved at working port A, and at the same time, throttling of oil return is achieved at pressure port P via working port B.

[0071] like Figure 10 As shown, valve core 2 moves further to the right until it is fully reversed. At this time, valve core 2 is in the second working position. The pressure port P adjacent to working port A is connected to working port A through the first flow channel 211; working port B is connected to the adjacent return port T through the second flow channel 212; the second pressure relief channel 242 is only connected to working port B and is not connected to the adjacent pressure port P, and the second pressure relief channel 242 no longer relieves pressure. At this time, oil can enter through working port A and return through working port B.

[0072] Based on the above scheme, the transition function hydraulic valve in this embodiment can achieve the working mode of first throttling the pressure port to the working port during the switching process from the neutral position to the working position, and then partially depressurizing before connecting to the working port again. This avoids both the sudden impact of high pressure and the problems of delayed response and lag in action.

[0073] In addition, the pressure relief grooves can be configured as needed, such as by setting only the first pressure relief groove 241; or only the second pressure relief groove 242; or by setting both the first pressure relief groove 241 and the second pressure relief groove 242. The shape and number of pressure relief grooves can also be set accordingly. By setting these parameters, an ideal opening and closing curve for the pressure relief grooves can be obtained, thereby achieving precise pressure relief flow control.

[0074] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A transitional function hydraulic valve, characterized in that, include: Valve body (1), wherein the valve body (1) is provided with a pressure oil port P, a return oil port T and at least one working oil port; Valve core (2), which is slidably assembled in the valve body (1) and slides to control the opening and closing of the oil ports; When the valve core (2) is in the neutral position, the working oil port is disconnected from the pressure oil port P and the return oil port T. A first transition position and a second transition position are formed sequentially between the valve core (2) moving from the neutral position to the working position where the working oil port and the pressure oil port P are connected. When the valve core (2) is in the first transition position, the pressure oil port P and the working oil port are connected by a throttling connection. When the valve core (2) is in the second transition position, the pressure oil port P and the working oil port are connected by a throttling connection, and at the same time, the pressure oil port P is also connected by a throttling connection to the return oil port T.

2. The transitional function hydraulic valve according to claim 1, characterized in that, There are two working ports. When the valve core (2) is in the first transition position, the pressure port P is throttled and connected to one working port, and the other working port is throttled and connected to the return port T.

3. A transitional function hydraulic valve according to claim 2, characterized in that, When the valve core (2) is in the second transition position, the pressure port P is throttled and connected to a working port, and the pressure port P is throttled and connected to the return port T through another working port.

4. A transitional function hydraulic valve according to claim 3, characterized in that, A flow groove is formed on the valve core (2). The flow groove is set in correspondence with the working oil port. In the working position, the working oil port flows through the flow groove to the pressure oil port P or the return oil port T over a large area.

5. A transitional function hydraulic valve according to claim 4, characterized in that, The valve core (2) has an inlet throttling groove and an outlet throttling groove formed on its outer peripheral surface. The pressure port P is throttled and connected to the working port through the inlet throttling groove, and the working port is throttled and connected to the return port T through the outlet throttling groove.

6. A transitional function hydraulic valve according to claim 5, characterized in that, The inlet throttling groove extends from the opening of the flow channel toward the pressure oil port P, and the outlet throttling groove extends from the opening of the flow channel toward the return oil port T.

7. A transitional function hydraulic valve according to claim 5, characterized in that, A pressure relief groove is formed on the outer peripheral surface of the valve core (2). When the valve core (2) is in the second transition position, the pressure oil port P is connected to another working oil port through the pressure relief groove, and the other working oil port is throttled and connected to the return oil port T.

8. A transitional function hydraulic valve according to claim 7, characterized in that, The pressure relief groove is located on the side of the flow channel near the pressure port P, and the axial length of the flow channel is greater than the minimum distance from the pressure port P to the corresponding working port.

9. A transitional function hydraulic valve according to claim 7, characterized in that, The pressure relief groove can be configured as several, and the pressure relief grooves for the same working oil port are arranged circumferentially.

10. A transitional function hydraulic valve according to any one of claims 2-9, characterized in that, Each working port is provided with a pressure port P and a return port T on both sides of its axial direction. The valve core (2) controls the connection and disconnection between the working port and the adjacent pressure port P and return port T. The two pressure ports P are located inside the two working ports and are connected, and the two return ports T are located outside the two working ports and are connected.

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