A hydraulic multi-way valve

Abstract

A hydraulic multi-way valve. It solves the problem that the existing compensation valve core cannot pick up the load oil in the transition state. It includes a valve body, a valve core assembly and a first screw plug. The valve core assembly and the first screw plug cooperate with each other in the valve body to form a first cavity. The valve body is provided with a pressure oil port, an oil inlet, an oil outlet and a feedback oil port. The valve core assembly has a first state in which the oil inlet and the oil outlet are separated, a second state in which the oil inlet is opened when pressure oil is input to allow the valve core to move relative to the valve body, and a third state in which the oil inlet and the oil outlet are connected so that the valve core assembly is in dynamic balance. The valve core assembly is provided with a first channel for connecting the oil outlet with the feedback oil port when the valve core assembly is in the second state, and a second channel for connecting the pressure oil port with the first cavity via the feedback oil port when the valve core assembly is in the third state. The present invention has the advantages of simple structure, reliable operation, long service life, fast system response, etc.

Description

Technical Field

[0001] The invention relates to a hydraulic control system, in particular to a hydraulic multi-way valve. Background Art

[0002] Hydraulic multi-way valves are divided into open center multi-way valves and closed center multi-way valves. When the reversing valve stem of the open center multi-way valve does not change direction, the oil of the oil pump flows through the reversing valve stem of the multi-way valve and flows through the return oil T port; when the reversing valve stem of the closed center multi-way valve does not change direction, no oil passes through the reversing valve stem. If it is a constant output oil source such as a gear pump, the oil flows to the T port at a certain constant pressure through the three-way compensation valve core (commonly known as a diverter valve). If it is a variable pump, etc., it relies on the variable mechanism of the oil pump to always maintain a nearly zero displacement state. The most commonly used system for closed center multi-way valves is to form a load-sensitive system with a fixed displacement pump or a load-sensitive pump, and the load-sensitive system has been applied on a large scale and in batches.

[0003] Compensation valve cores are generally used in load-sensitive hydraulic multi-way valves. Their purpose is to achieve simultaneous action of multiple actions in different links when the flow is insufficient. The function of the general compensation valve core is to simply move under the action of pressure, and to adjust the size of the throttle by movement to achieve the compensation effect. Some compensation valve cores also have the function of load pickup, but basically they can only be picked up near the end of the stroke.

[0004] The three states of the compensation valve core are the initial state, the transition state and the terminal state. The stroke of the terminal state generally accounts for only about 5% of the total stroke, and most of the states are transition states. In the transition state, the existing compensation valve core cannot pick up the load oil, which will cause the load pressure oil to be interrupted. How to pick up the load oil in time in the transition state is a research direction. Summary of the invention

[0005] In order to solve the problem in the background technology that the existing compensation valve core cannot pick up the load oil in the transition state, the present invention provides a hydraulic multi-way valve.

[0006] The technical solution of the present invention is: a hydraulic multi-way valve, including a valve body, a valve core assembly and a first screw plug, the valve core assembly and the first screw plug cooperate with each other in the valve body to form a first cavity, the valve body is provided with a pressure oil port, an oil inlet, an oil outlet and a feedback oil port for receiving or outputting feedback pressure oil, the valve core assembly has a first state of isolating the oil inlet and the oil outlet, a second state in which the oil inlet is opened when pressure oil is input so that the valve core moves relative to the valve body, and a third state in which the oil inlet and the oil outlet are connected so that the valve core assembly is in dynamic balance, the valve core assembly is provided with a first channel for connecting the oil outlet with the feedback oil port when the valve core assembly is in the second state, and a second channel for connecting the pressure oil port with the first cavity via the feedback oil port when the valve core assembly is in the third state.

[0007] As an improvement of the present invention, the valve core assembly includes a valve core and a second screw plug, and a cavity is provided on the valve core. When the valve core assembly is in the second state, the oil inlet is connected with the feedback oil port through the cavity, and when the valve core assembly is in the third state, the feedback oil port is connected with the first cavity through the cavity.

[0008] As a further improvement of the present invention, the valve core is provided with a first connecting hole for connecting the cavity with the feedback oil port.

[0009] As a further improvement of the present invention, a second connecting hole for connecting the oil outlet and the cavity is provided on the valve core, and a one-way valve is provided between the second connecting hole and the cavity.

[0010] As a further improvement of the present invention, when the valve core assembly is in the second state, the pressure oil at the oil inlet is connected to the feedback oil port through the oil outlet, the second connecting hole, the one-way valve, the cavity in sequence; when the valve core assembly is in the third state, the pressure oil at the pressure oil port is connected to the first containing cavity through the feedback oil port, the first connecting hole, the cavity in sequence and balances the pressure at both ends of the valve core assembly.

[0011] As a further improvement of the present invention, the one-way valve includes a valve ball, an elastic member and a third screw plug, the valve ball having a first position for blocking the oil outlet and the cavity and a second position for opening the oil outlet and connecting the oil outlet to the cavity, the valve ball is in the first position when the valve core assembly is in the first state and the third state, and the valve ball is in the second position when the valve core assembly is in the second state.

[0012] As a further improvement of the present invention, a damping hole is provided on the third screw plug, and the damping hole is communicated with the cavity.

[0013] As a further improvement of the present invention, when the valve core assembly is in the third state, the pressure of the first chamber is equal to the pressure of the feedback oil port and is greater than the pressure at the oil outlet.

[0014] As a further improvement of the present invention, the effective pressure areas at both ends of the valve core are the same.

[0015] As a further improvement of the present invention, the second screw plug is provided with a damping through hole for connecting the cavity with the first cavity, and a reset member is provided in the first cavity. The two ends of the reset member are respectively against the first screw plug and the second screw plug and have a movement tendency of driving the valve core assembly to the first state through the second screw plug.

[0016] The beneficial effect of the present invention is that two pick-up channels are provided on the valve core assembly, the first channel is in effect when the valve core assembly is in the second state, and the second channel is in effect when the valve core assembly is in the third state, and the pressure can be reliably picked up to the feedback oil port from the start of the stroke to the final state, so that the product is sensitive and responsive, and the load pressure oil is prevented from being interrupted. The present invention also has the advantages of simple structure, convenient assembly, reliable action, long service life, and fast system response. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is a structural schematic diagram of the valve core assembly in the first state according to an embodiment of the present invention.

[0018] Attached Figure 2 It is a schematic structural diagram of the valve core assembly in the second state according to an embodiment of the present invention.

[0019] Attached Figure 3 It is a structural schematic diagram of the valve core assembly in the third state according to an embodiment of the present invention.

[0020] Attached Figure 4 For attachment Figure 2 Schematic diagram of the structure of the middle valve core.

[0021] In the figure, 1, valve body; 11, first screw plug; 12, first cavity; 13, reset member; 2, valve core assembly; 21, valve core; 211, cavity; 212, first connecting hole; 213, second connecting hole; 22, second screw plug; 221, damping through hole; 3, first channel; 4, second channel; 5, one-way valve; 51, valve ball; 52, elastic member; 53, third screw plug; 531, damping hole; P, pressure oil port; P1, oil inlet; P2, oil outlet; PLs, feedback oil port. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are further described below in conjunction with the accompanying drawings:

[0023] Depend on Figure 1 Combination Figure 2-3As shown, a hydraulic multi-way valve comprises a valve body 1, a valve core assembly 2 and a first screw plug 11, wherein the valve core assembly 2 and the first screw plug 11 cooperate with each other in the valve body 1 to form a first volume 12, wherein the valve body is provided with a pressure oil port P, an oil inlet P1, an oil outlet P2 and a feedback oil port PLs for receiving or outputting feedback pressure oil, wherein the valve core assembly 2 has a first state in which the oil inlet and the oil outlet are separated, a second state in which the oil inlet is opened when pressure oil is input so that the valve core moves relative to the valve body, and a third state in which the oil inlet and the oil outlet are connected so that the valve core assembly is in dynamic balance, wherein the valve core assembly is provided with a first channel 3 for connecting the oil outlet with the feedback oil port when the valve core assembly is in the second state, and a second channel 4 for connecting the pressure oil port with the first volume via the feedback oil port when the valve core assembly is in the third state. When the valve core assembly is in the second state, the valve core assembly opens the oil inlet and the oil outlet to connect. The beneficial effect of the present invention is that two pick-up channels are provided on the valve core assembly, the first channel is in effect when the valve core assembly is in the second state, and the second channel is in effect when the valve core assembly is in the third state, and the pressure can be reliably picked up to the feedback oil port from the start of the stroke to the final state, so that the product is sensitive and responsive, and the load pressure oil is prevented from being interrupted. The present invention also has the advantages of simple structure, convenient assembly, reliable action, long service life, and fast system response.

[0024] The reset member and the elastic member may both be springs, which are only used for positioning (or restoring to an initial state). In practice, their acting force is very weak. When explaining force balance in the present invention, their force values ​​are ignored, and their influence on the balance state of the valve core is not considered.

[0025] The valve core of the present invention has the following three states:

[0026] 1. When the valve core assembly is in the first state, that is, the valve core is in the initial state, such as Figure 1 As shown, in the initial state, the reset member makes the valve core assembly in the right position, and the oil channels are not communicating.

[0027] 2. When the valve core assembly is in the third state, that is, the valve core is in the end state, such as Figure 3As shown, in the end state, the valve core assembly moves to the left position, the pressure oil port P and the feedback oil port PLs are connected, and a certain flow rate passes through the PLs port. The connection between the P port and the PLs port can only be achieved when there is flow in the system, otherwise the valve core assembly will not be able to move. The reason is that the first volume chamber (PLsa volume chamber) is a dead volume chamber when there is no flow outflow, and the liquid inside cannot flow out, and it cannot move. The oil in the feedback oil port PLs flows through the damping through hole 221 to the first volume chamber on the left to form PLsa. The pressure of PLsa and PLs is the same when the valve core is static. Since the effective pressure area at both ends of the valve core is the same, that is, the areas of A1 and A2 in the figure are equal, the oil inlet P1 is equal to the first volume chamber PLsa, and PLsa comes from PLs and is equal, so the pressure of PLs and P1 is equal.

[0028] 3. When the valve core assembly is in the second state, the valve core is in a transition state: Figure 2 As shown, in the transition state, the valve core is neither in the left position nor in the right position. At this time, the P port and PLs and PLsa are isolated. The one-way valve composed of sequence 3.3, sequence 3.4 and sequence 3.5 introduces the oil at the P2 port into PLs and PLsa in one direction. In this case, the pressure of P2 is equal to that of PLS ​​and PLsa.

[0029] In the transition state, the valve core will continue to move left under the pressure of the oil inlet P1 until it reaches the terminal state. The final position of the valve core is determined by the size of the three pressures of P1, PLS and PLSa. Since the flow flows from the oil inlet P1 to the oil outlet P2, there is no doubt that the pressure of P1 is greater than the pressure of P2. Therefore, the transition state is only a short process, and the valve core assembly will definitely reach the terminal state under the continuous action of P1.

[0030] The terminal state is also a dynamic equilibrium state and is not static. When the pressure of the pressure oil port P is high, the stroke of the valve core is small (i.e., it moves less to the left); when the pressure of the P port is low, the stroke of the valve core is large. In the terminal state, since P1 is greater than P2, and P1 is equal to PLs and PLsa, that is, the pressure in the cavity 211 is greater than the pressure of the oil outlet P2, the one-way valve composed of the valve ball, the elastic member and the third screw plug cannot introduce the oil of P2, and the one-way valve cannot guide the oil at this time. The multifunctional valve core of the present invention can ensure that P1 is equal to PLs and PLsa in the terminal state, and effectively compensates for the lack of pressure in the PLs and PLsa cavities in the transition state, so that the product control is reliable, the response is timely, and the efficiency is high.

[0031] The valve core assembly 2 includes a valve core 21 and a second screw plug 22. The valve core is provided with a cavity 211. When the valve core assembly is in the second state, the oil inlet is connected to the feedback oil port through the cavity. When the valve core assembly is in the third state, the feedback oil port is connected to the first cavity through the cavity. Such a structure facilitates the connection between the oil outlet and the cavity, so that the valve core can also conduct the feedback oil port in the transition state, which is convenient for picking up load oil, making the system oil pressure distribution more reasonable, and utilizing different working linkages. Specifically, the second screw plug is inserted into the cavity of the valve core and linked to the valve core.

[0032] The valve core 21 is provided with a first connecting hole 212 for connecting the cavity and the feedback oil port. Specifically, the valve core 21 is provided with a second connecting hole 213 for connecting the oil outlet and the cavity, and a check valve 5 is provided between the second connecting hole 213 and the cavity 211. More specifically, when the valve core assembly is in the second state, the pressure oil of the oil inlet is connected to the feedback oil port PLs through the oil outlet P2, the second connecting hole 213, the check valve 5, and the cavity 211 in sequence, and when the valve core assembly is in the third state, the pressure oil of the pressure oil port is connected to the first chamber 12 through the feedback oil port PLs, the first connecting hole 212, and the cavity 211 in sequence and balances the pressure at both ends of the valve core assembly. Such a structure enables the valve core assembly to reliably open the check valve to pick up the pressure oil of the oil outlet when it is in the second state, and to reliably pick up the pressure oil of the pressure oil port and close the check valve when it is in the third state, so that the valve core assembly can be in a reliable dynamic balance.

[0033] The one-way valve 5 comprises a valve ball 51, an elastic member 52 and a third screw plug 53. The valve ball has a first position for blocking the oil outlet and the cavity and a second position for opening the oil outlet and connecting the cavity. When the valve core assembly is in the first state and the third state, the valve ball is in the first position, and when the valve core assembly is in the second state, the valve ball is in the second position. A damping hole 531 is provided on the third screw plug 53, and the damping hole is connected to the cavity. The setting of the damping hole forms a pressure difference at the cavity, which can reliably close the valve ball, facilitate reliable control of the product, and prevent the valve ball from being opened when the valve core assembly is in the third state.

[0034] When the valve core assembly is in the third state, the pressure of the first chamber is equal to the pressure of the feedback oil port and greater than the pressure at the oil outlet. Specifically, the effective pressure areas at both ends of the valve core are the same. Such a structure makes the pressure of the feedback oil port equal to the pressure at the oil inlet when the valve core assembly is in the third state.

[0035] The second screw plug 22 is provided with a damping through hole 221 for connecting the cavity with the first cavity, and the first cavity is provided with a reset member 13, the two ends of which are respectively against the first screw plug and the second screw plug and have a movement tendency to drive the valve core assembly to the first state through the second screw plug. Such a structure can reliably close the valve core when the valve core assembly is in the first state.

[0036] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] Technical personnel should note that although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention, and any modification using the inventive concept will be included in the scope of protection of this patent.

Claims

1. A hydraulic multi-way valve, comprising a valve body, a valve core assembly and a first screw plug, characterized in that : The valve core assembly and the first screw plug cooperate with each other in the valve body to form a first cavity, the valve body is provided with a pressure oil port, an oil inlet, an oil outlet and a feedback oil port for receiving or outputting feedback pressure oil, the valve core assembly has a first state of isolating the oil inlet and the oil outlet, a second state in which the oil inlet is opened when pressure oil is input so that the valve core moves relative to the valve body, and a third state in which the oil inlet and the oil outlet are connected so that the valve core assembly is in dynamic balance, the valve core assembly is provided with a first channel for connecting the oil outlet and the feedback oil port when the valve core assembly is in the second state, and a second channel for connecting the pressure oil port to the first cavity via the feedback oil port when the valve core assembly is in the third state, the valve core assembly includes a valve core and a second Screw plug, a cavity is provided on the valve core, when the valve core assembly is in the second state, the oil outlet is connected with the feedback oil port through the cavity, when the valve core assembly is in the third state, the feedback oil port is connected with the first cavity through the cavity, a first connecting hole for connecting the cavity and the feedback oil port is provided on the valve core, a second connecting hole for connecting the oil outlet and the cavity is provided on the valve core, a one-way valve is provided between the second connecting hole and the cavity, when the valve core assembly is in the second state, the pressure oil at the oil inlet is connected to the feedback oil port through the oil outlet, the second connecting hole, the one-way valve, the cavity in turn, when the valve core assembly is in the third state, the pressure oil at the pressure oil port is connected to the first cavity through the feedback oil port, the first connecting hole, the cavity in turn, and balances the pressure at both ends of the valve core assembly.

2. A hydraulic multi-way valve according to claim 1, characterized in that The one-way valve includes a valve ball, an elastic member and a third screw plug. The valve ball has a first position for blocking the oil outlet and the cavity and a second position for opening the oil outlet and connecting the cavity. When the valve core assembly is in the first state and the third state, the valve ball is in the first position, and when the valve core assembly is in the second state, the valve ball is in the second position.

3. A hydraulic multi-way valve according to claim 2, characterized in that The third screw plug is provided with a damping hole, and the damping hole is communicated with the cavity.

4. A hydraulic multi-way valve according to claim 1, characterized in that When the valve core assembly is in the third state, the pressure of the first chamber is equal to the pressure of the feedback oil port and is greater than the pressure at the oil outlet.

5. A hydraulic multi-way valve according to claim 1, characterized in that The effective pressure areas at both ends of the valve core are the same.

6. A hydraulic multi-way valve according to claim 1, characterized in that The second screw plug is provided with a damping through hole for connecting the cavity with the first cavity, and the first cavity is provided with a reset member, the two ends of which are respectively against the first screw plug and the second screw plug and have a movement tendency of driving the valve core assembly to the first state through the second screw plug.

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