A hydraulic differential valve

Abstract

The present invention is applicable to the field of hydraulic technology and provides a hydraulic differential valve, which includes a valve body with a valve cavity formed inside thereof, and a first oil port and a second oil port communicating with the valve cavity are provided thereon; a valve core is slidably disposed in the valve cavity to control the communication state between the first oil port and the second oil port; a third oil port and a fourth oil port are further provided on the valve body; a sliding sleeve is further disposed in the valve cavity, and a sliding member is slidably disposed in the sliding sleeve; one end of the sliding member is in contact with one end of the valve core; a first seal is provided at one end of the valve body close to the sliding sleeve, and a second seal is provided at the other end; a cavity formed between the inner wall of the sliding sleeve and the first seal at the end of the sliding member away from the valve core communicates with the third oil port; a cavity formed between the valve core wall of the valve cavity and the second seal at the end of the valve core away from the sliding member communicates with the fourth oil port; the structure of this embodiment is simple, which can effectively reduce the number of components in the hydraulic system and can quickly conduct or cut off the first oil port and the second oil port.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulics, and particularly relates to a hydraulic differential valve. Background Art

[0002] When designing a hydraulic system, it is often necessary to automatically conduct or cut off an oil circuit according to a pressure ratio; in the existing hydraulic system, a pressure sensor or a pressure relay is usually arranged on an oil cylinder to collect its electrical signal, and then an electromagnetic valve connecting the oil cylinder in the hydraulic system and the high-pressure accumulator in the hydraulic system is controlled through an electrical system to conduct the oil of the high-pressure accumulator into the oil cylinder to do work, so as to realize the automatic conduction and cut-off of the high-pressure accumulator and the oil cylinder. However, when the existing hydraulic system conducts and cuts off the oil circuit automatically, it takes a long time, which will reduce the working efficiency of the hydraulic system. At the same time, there are many components used, which not only increases the cost, but also makes the design and debugging more cumbersome, increasing the failure rate. Summary of the Invention

[0003] An object of an embodiment of the present invention is to provide a hydraulic differential valve, aiming at solving the problems proposed in the above background art.

[0004] To achieve the above object, the embodiment of the present invention is implemented as follows:

[0005] A hydraulic differential valve, the hydraulic differential valve includes:

[0006] A valve body, which is internally provided with a valve cavity, and is provided with a first oil port and a second oil port communicated with the valve cavity thereon;

[0007] A valve core, which is slidably arranged in the valve cavity of the valve body and is used to control the communication state of the first oil port and the second oil port;

[0008] Wherein, the valve body is further provided with a third oil port and a fourth oil port; a sliding sleeve is further arranged in the valve cavity of the valve body, and a sliding member is slidably arranged inside the sliding sleeve; one end of the sliding member is in contact with one end of the valve core; a first sealing member is detachably arranged at one end of the valve body close to the sliding sleeve, and a second sealing member is detachably arranged at the other end of the valve body, for sealing the valve cavity; a cavity formed between the end of the sliding member away from the valve core, the inner wall of the sliding sleeve and the first sealing member is a first cavity, and the first cavity is communicated with the third oil port; a cavity formed between the end of the valve core away from the sliding member, the cavity wall of the valve cavity and the second sealing member is a second cavity, and the second cavity is communicated with the fourth oil port.

[0009] In a preferred embodiment of the present invention, two convex portions are arranged on the valve core and are respectively used for blocking the first oil port and the second oil port; other parts of the valve core except the two convex portions do not contact the cavity wall of the valve cavity.

[0010] In a preferred embodiment of the present invention, at least two first sealing grooves are provided on the sliding sleeve, and a third sealing member is sleeved on the first sealing groove; a first through hole for communicating the first cavity and the third oil port is provided on the sliding sleeve, and the first through hole is located between the two sealing grooves.

[0011] In a preferred embodiment of the present invention, the third sealing member includes a first sealing ring and a retaining ring; the first sealing ring and the retaining ring are sleeved in the first sealing groove and are in contact with the inner wall of the valve cavity.

[0012] In a preferred embodiment of the present invention, the cavity formed by the protruding portion of the valve core close to the sliding member, the sliding member, the inner wall of the sliding sleeve, and the inner wall of the valve cavity is the third cavity; an oil drain port is further provided on the valve body, and the third cavity is communicated with the oil drain port.

[0013] In a preferred embodiment of the present invention, the first sealing member includes an end cover and a plug; the end cover is detachably connected to the valve body, and the plug is provided at the end of the inner cavity of the sliding sleeve and is in contact with the end cover.

[0014] In a preferred embodiment of the present invention, at least one second sealing groove is provided on the plug, a second sealing ring is sleeved on the second sealing groove, and the second sealing ring is in contact with the inner wall of the sliding sleeve.

[0015] In a preferred embodiment of the present invention, the end cover and the valve body are connected by a threaded connection method, and at least two threaded holes are provided on the end cover.

[0016] In a preferred embodiment of the present invention, the second sealing member is a plug, a washer is sleeved on the plug and is screwed onto the valve body to block one end of the valve cavity.

[0017] The hydraulic differential valve provided by the embodiment of the present invention has the following beneficial effects:

[0018] (1) By introducing hydraulic oils with different pressures into the first cavity and the second cavity through the third oil port and the fourth oil port respectively, the valve core is driven to slide in the valve cavity under the action of the hydraulic oil pressure, so as to quickly realize the on and off of the first oil port and the second oil port, which is beneficial to improving the working efficiency of the hydraulic system;

[0019] (2) The structure of the embodiment of the present invention is simple, which can effectively reduce the number of components in the hydraulic system, reduce costs, and reduce the failure rate of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of a hydraulic differential valve provided by an embodiment of the present invention;

[0021] Figure 2 The left view of a hydraulic differential valve provided by an embodiment of the present invention;

[0022] Figure 3 The structural schematic diagram of a valve body in a hydraulic differential valve provided by an embodiment of the present invention;

[0023] Figure 4 The structural schematic diagram of a valve core in a hydraulic differential valve provided by an embodiment of the present invention;

[0024] Figure 5 The structural schematic diagram of a sliding member in a hydraulic differential valve provided by an embodiment of the present invention;

[0025] Figure 6 The structural schematic diagram of a sliding sleeve in a hydraulic differential valve provided by an embodiment of the present invention;

[0026] Figure 7 The external structural schematic diagram of a sliding sleeve in a hydraulic differential valve provided by an embodiment of the present invention;

[0027] Figure 8 The structural schematic diagram of a plug in a hydraulic differential valve provided by an embodiment of the present invention.

[0028] In the drawings: 1, valve body; 101, valve cavity; 2, valve core; 3, sliding member; 4, sliding sleeve; 401, first through hole; 402, second through hole; 403, first sealing groove; 5, plug; 501, second sealing groove; 6, end cover; 7, screw plug; 8, first oil port; 9, second oil port; 10, third oil port; 11, fourth oil port; 12, oil drain port; 13, washer; 14, retaining ring; 15, first sealing ring; 16, second sealing ring. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The following describes the specific implementation of the present invention in detail with reference to specific embodiments.

[0031] As Figure 1 shown, the structural schematic diagram of a hydraulic differential valve provided by an embodiment of the present invention includes:

[0032] A valve body 1, which is internally provided with a valve cavity 101, and is provided with a first oil port 8 and a second oil port 9 communicating with the valve cavity 101;

[0033] The valve core 2 is slidably disposed in the valve cavity 101 of the valve body 1 and is used to control the communication state between the first oil port 8 and the second oil port 9;

[0034] Among them, as Figure 3 shown, a third oil port 10 and a fourth oil port 11 are further provided on the valve body 1; a sliding sleeve 4 is further disposed in the valve cavity 101 of the valve body 1, and a sliding member 3 is slidably disposed inside the sliding sleeve 4; one end of the sliding member 3 is in contact with one end of the valve core 2; a first seal is detachably provided at one end of the valve body 1 near the sliding sleeve 4, and a second seal is detachably provided at the other end for sealing the valve cavity 101; a cavity formed between the end of the sliding member 3 away from the valve core 2, the inner wall of the sliding sleeve 4, and the first seal is a first cavity, and the first cavity communicates with the third oil port 10; a cavity formed between the end of the valve core 2 away from the sliding member 3, the cavity wall of the valve cavity 101, and the second seal is a second cavity, and the second cavity communicates with the fourth oil port 11.

[0035] In the embodiment of the present invention, as Figure 4 shown, the valve core 2 is in a dumbbell shape, and two convex portions that are in fit with the cavity wall of the valve cavity 101 are provided thereon, respectively for blocking the first oil port 8 and the second oil port 9; other parts of the valve core 2 except the two convex portions do not contact the cavity wall of the valve cavity 101; as Figure 5 shown, the sliding member 3 is a plunger and is in fit with the inner wall of the sliding sleeve 4; hydraulic oils with different pressures are respectively introduced into the first cavity and the second cavity through the third oil port 10 and the fourth oil port 11; the pressures of the hydraulic oils in the first cavity and the second cavity acting on the sliding member 3 and the valve core 2 are different, and under the action of the pressure difference, the valve core 2 can be driven to slide in the valve cavity 101, as Figure 1In the shown direction, when the force exerted by the hydraulic oil in the first cavity on the spool 2 is greater than the force exerted by the hydraulic oil in the second cavity on the spool 2, the spool 2 is located on the right side of the valve cavity 101, thereby blocking the communication between the first oil port 8 and the second oil port 9; when the force exerted by the hydraulic oil in the second cavity on the spool 2 is greater than the force exerted by the hydraulic oil in the first cavity on the spool 2, the spool 2 slides to the left side of the valve cavity 101, thereby enabling the communication between the first oil port 8 and the second oil port 9, realizing the automatic conduction and cutting-off of the first oil port 8 and the second oil port 9; compared with the existing hydraulic system, a hydraulic differential valve provided by an embodiment of the present invention adopts a pure mechanical mechanism, eliminating intermediate links such as pressure signal acquisition, control system judgment, electrical power output, and solenoid valve commutation, and can achieve the rapid conduction and switching of the first oil port 8 and the second oil port 9, which is beneficial to improving the working efficiency of the hydraulic system. Moreover, the hydraulic differential valve has a simple structure, can effectively reduce the number of hydraulic system components, thereby reducing costs, and can also reduce the failure rate of the hydraulic system; since the hydraulic force depends on the pressure and acting area of the hydraulic oil, in the embodiment of the present invention, the acting area of the hydraulic oil in the second cavity on the spool 2 remains unchanged, and the acting area of the hydraulic oil in the first cavity on the sliding member 3 can be changed by changing the inner diameter of the sliding sleeve 4, thereby changing the ratio of the pressure of the hydraulic oil in the first cavity to the pressure of the hydraulic oil in the second cavity when driving the spool 2 to slide, facilitating the control of the operation of the hydraulic differential valve.

[0036] As Figure 6 and Figure 7 shown, as another preferred embodiment of the present invention, two first sealing grooves 403 are provided on the sliding sleeve 4; a first through hole 401 for communicating the first cavity and the third oil port 10 is provided on the sliding sleeve 4, and the first through hole 401 is located between the two sealing grooves; hydraulic oil enters the first cavity through the third oil port 10 and the first through hole 401 to exert a force on the sliding member 3; a third sealing member is sleeved on the first sealing groove 403. As Figure 1 shown, the third sealing member includes a first sealing ring 15 and a retaining ring 14; the first sealing ring 15 and the retaining ring 14 are sleeved in the first sealing groove 403 and are in contact with the cavity wall of the valve cavity 101; the first cavity can be sealed by the first sealing ring 15 and the retaining ring 14 to prevent the hydraulic oil entering the first cavity from leaking.

[0037] As Figure 1As shown, as another preferred embodiment of the present invention, the cavity formed by the convex portion of the valve core 2 near the sliding member 3, the sliding member 3, the inner wall of the sliding sleeve 4, and the wall of the valve cavity 101 is the third cavity; an oil drain port 12 is further provided on the valve body 1; as Figure 6 and Figure 7 shown, a second through hole 402 is further provided on the sliding sleeve 4, and the third cavity communicates with the oil drain port 12 through the second through hole 402. The oil drain port 12 can eliminate the volume change of the third cavity when the valve core 2 and the sliding member 3 act and move, prevent cavitation and oil entrapment, and improve the smoothness and service life of the hydraulic differential valve during operation.

[0038] As Figure 1 shown, as another preferred embodiment of the present invention, the first seal includes an end cap 6 and a plug 5; as Figure 2 shown, the end cap 6 and the valve body 1 are connected by a threaded connection. Four threaded holes are evenly spaced on the end cap 6 and are connected to the valve body 1 by screws or bolts; in accordance with Figure 1 the direction shown, the left end of the inner cavity of the sliding sleeve 4 is stepped, and the plug 5 is placed at the left end of the inner cavity of the sliding sleeve 4 and fits with the end cap 6. After the end cap 6 is fixed, the end cap 6 and the plug 5 can seal one end of the valve cavity 101, and the plug 5 can also play a limiting role on the sliding member 3.

[0039] As Figure 8 shown, as another preferred embodiment of the present invention, a second seal groove 501 is provided on the plug 5, and a second sealing ring 16 is sleeved on the second seal groove 501. The second sealing ring 16 fits with the inner wall of the sliding sleeve 4, so as to seal the first cavity and prevent the hydraulic oil in the first cavity from leaking from the joint between the plug 5 and the inner wall of the sliding sleeve 4.

[0040] As Figure 1 shown, as another preferred embodiment of the present invention, the second seal is a plug 7. A washer 13 is sleeved on the plug 7 and screwed onto the valve body 1. The washer 13 can be a combined washer or a flat washer; the plug 7 can seal one end of the valve core 2 to prevent the hydraulic oil in the second cavity from leaking, and can also play a limiting role on the valve core 2.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0043] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydraulic differential valve, characterized in that, the hydraulic differential valve comprises: a valve body with a valve cavity inside, and a first oil port and a second oil port communicating with the valve cavity are provided thereon; a valve core slidably disposed in the valve cavity of the valve body for controlling the communication state between the first oil port and the second oil port; wherein, a third oil port and a fourth oil port are further provided on the valve body; a sliding sleeve is further provided in the valve cavity of the valve body, and a sliding member is slidably disposed inside the sliding sleeve; one end of the sliding member is in contact with one end of the valve core; a first sealing member is detachably provided at one end of the valve body close to the sliding sleeve, and a second sealing member is detachably provided at the other end for sealing the valve cavity; a cavity formed between the end of the sliding member far from the valve core, the inner wall of the sliding sleeve and the first sealing member is a first cavity, and the first cavity communicates with the third oil port; a cavity formed between the end of the valve core far from the sliding member, the cavity wall of the valve cavity and the second sealing member is a second cavity, and the second cavity communicates with the fourth oil port.

2. The hydraulic differential valve according to claim 1, characterized in that, two convex portions that fit with the cavity wall of the valve cavity are provided on the valve core, respectively for blocking the first oil port and the second oil port; other parts of the valve core except the two convex portions do not contact the cavity wall of the valve cavity.

3. The hydraulic differential valve according to claim 1, characterized in that, at least two first sealing grooves are provided on the sliding sleeve, and a third sealing member is sleeved on the first sealing groove; a first through hole for communicating the first cavity and the third oil port is provided on the sliding sleeve, and the first through hole is located between the two sealing grooves.

4. The hydraulic differential valve according to claim 3, characterized in that, the third sealing member comprises a first sealing ring and a retaining ring; the first sealing ring and the retaining ring are sleeved in the first sealing groove and fit with the cavity wall of the valve cavity.

5. The hydraulic differential valve according to claim 2, characterized in that, a cavity formed by the convex portion of the valve core close to the sliding member, the sliding member, the inner wall of the sliding sleeve and the cavity wall of the valve cavity is a third cavity; a drain port is further provided on the valve body, and the third cavity communicates with the drain port.

6. The hydraulic differential valve according to claim 1, characterized in that, the first sealing member comprises an end cover and a plug; the end cover is detachably connected to the valve body, and the plug is disposed at the end of the inner cavity of the sliding sleeve and fits with the end cover.

7. The hydraulic differential valve according to claim 6, characterized in that, at least one second sealing groove is provided on the plug, and a second sealing ring is sleeved on the second sealing groove, and the second sealing ring fits with the inner wall of the sliding sleeve.

8. The hydraulic differential valve according to claim 6, characterized in that, the end cover and the valve body are connected by a threaded connection method, and at least two threaded holes are provided on the end cover.

9. The hydraulic differential valve according to claim 1, characterized in that, The second seal is a plug, and a washer is sleeved on the plug and screwed onto the valve body to block one end of the valve cavity.

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