A load-holding cartridge-type multi-way valve

Abstract

The present invention relates to the field of hydraulic technology, and particularly relates to a load-holding cartridge multi-way valve, which comprises a valve body. A spool hole, a working oil chamber, an oil inlet chamber and an oil return chamber communicating with the spool hole are arranged in the valve body. The oil inlet chamber is connected to an oil inlet, and the oil return chamber is connected to an oil return port; a spool is placed in the spool hole for oil circuit conversion; a check valve hole communicates with one of the working oil chambers, a check valve is arranged in the check valve hole, and a cavity communicating with the working oil chamber is provided inside the check valve; at least one pilot oil chamber, an intermediate body, the intermediate body is provided with a pilot passage for communicating the pilot oil chamber with the spool hole to push the spool to move and an intermediate passage communicating with the cavity of the check valve, a switching mechanism, and the switching mechanism is used for connecting or disconnecting the intermediate passage and the pilot oil chamber. In the present invention, the oil in the cavity of the check valve is communicated to the intermediate passage at the end of the spool hole, which facilitates the realization of the seal between the cavity of the check valve and the spool hole.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, and particularly relates to a load-holding cartridge multi-way valve. Background Art

[0002] In the prior art, the on-off of the oil circuit in a multi-way valve is controlled by a check valve. For example, in the patent with the patent number CN207568965U, when the control valve is in the neutral position, due to the gravity of the working device, a certain pressure is generated on the actuator (oil cylinder). This pressure is transmitted to the main spool through the check valve and the pipeline. Since the main spool is arranged in the spool hole in a sliding way, there is always a gap between the main spool and the spool hole, resulting in a certain amount of leakage and causing the phenomenon of arm dropping. Summary of the Invention

[0003] In order to solve the problem of oil leakage and arm dropping when the spool of the multi-way valve in the prior art is in the neutral position for load holding, the present invention provides a load-holding cartridge multi-way valve that prevents oil leakage during load holding.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] A load-holding cartridge multi-way valve, characterized in that it includes

[0006] A valve body, in which a spool hole, a working oil chamber, an oil inlet chamber and an oil return chamber communicating with the spool hole are provided. The oil inlet chamber is connected to an oil inlet, and the oil return chamber is connected to an oil return port;

[0007] A spool, which is placed in the spool hole for oil circuit conversion;

[0008] A check valve hole, which communicates with one of the working oil chambers. A check valve is provided in the check valve hole, and a cavity communicating with the working oil chamber is provided inside the check valve;

[0009] At least one pilot oil chamber,

[0010] An intermediate body, which is provided with a pilot channel for communicating the pilot oil chamber with the spool hole to push the spool to move and an intermediate channel communicating with the cavity of the check valve;

[0011] An on-off mechanism, which is used to connect or disconnect the intermediate channel and the pilot oil chamber.

[0012] Further, the intermediate includes a push rod and a valve sleeve sleeved outside the push rod. The pilot passage is a central through hole provided in the center of the push rod. A first elastic element for pushing the push rod towards the valve core is provided between the push rod and the wall of the pilot oil chamber. One end of the valve sleeve extends into the valve core hole. The intermediate passage is a groove provided in the side wall of the valve sleeve. The on-off structure is a sealing structure provided at the other end of the valve sleeve to cooperate with the valve body to connect or disconnect the groove from the pilot oil chamber.

[0013] Further, the sealing structure includes a convex portion provided at the end of the valve sleeve.

[0014] Further, the contact position between the sealing structure and the valve body is a conical surface.

[0015] Further, a sealing ring is provided between the valve sleeve and the valve core hole near the valve core.

[0016] Further, after the valve core pushes the valve sleeve and / or the push rod by a set distance, the intermediate passage communicates with the pilot oil chamber. In this way, before the oil fluid at port P reaches the working oil port, the intermediate passage cannot communicate with the pilot oil chamber, so as to prevent the phenomenon of arm dropping.

[0017] Further, the valve sleeve is slidably connected to the push rod. A step for pushing the valve sleeve towards the valve core is provided on the push rod. The groove on the valve sleeve extends to the sealing structure. When the push rod abuts against the valve sleeve and the sealing structure of the valve sleeve cooperates with the valve body, the end of the push rod near the valve core extends beyond the end of the valve sleeve near the valve core, so that the valve core contacts the push rod first and then the valve sleeve. A limiting structure for limiting the valve sleeve before the valve core contacts the valve sleeve is provided on the valve body or between the valve sleeve and the push rod.

[0018] Further, the limiting structure is a second elastic element provided between the valve sleeve and the push rod. The structure is simple, easy to implement, and has low cost.

[0019] Further, the push rod and the valve sleeve are integrally formed or fixedly connected, and there is a distance between the groove and the convex portion of the valve sleeve.

[0020] Further, a pressure compensation chamber is further provided in the valve body. A pressure compensation valve is provided in the pressure compensation chamber. A compensation oil inlet chamber and a compensation oil outlet chamber are connected between the pressure compensation chamber and the valve core hole. A safety valve hole is provided between the working oil chamber and the oil return chamber. A safety valve is provided in the installation valve hole.

[0021] Beneficial effects:

[0022] (1) In the present invention, the hydraulic oil in the cavity of the check valve is communicated to the intermediate passage at the end position of the spool hole, and an on-off mechanism is provided to realize the on-off of the intermediate passage and the pilot oil cavity, which is not affected by the clearance between the spool and the spool hole, facilitating the sealing between the cavity of the check valve and the spool hole;

[0023] (2) When the spool is in the middle position, the valve sleeve sealing structure cooperates with the valve body, and the cavity a is sealed to ensure zero leakage. Specifically, it includes four seals. The first seal is the line seal between the check valve and the valve body; the second seal is the line seal between the safety valve of the B working oil port and the valve body; the third seal is the line seal between the valve sleeve and the valve body; the fourth seal is the seal of the sealing ring between the valve sleeve and the valve body. Thus, all four seals can prevent the hydraulic oil from leaking during load holding, and the sealing effect is good;

[0024] (3) After the spool pushes the valve sleeve and / or the ejector rod by a set distance, the intermediate passage is communicated with the pilot oil cavity, so that when the oil from the P port does not reach the A working oil port, the intermediate passage cannot be communicated with the pilot oil cavity to prevent the occurrence of the arm dropping phenomenon;

[0025] (4) During the movement of the spool, it first contacts the ejector rod and then contacts the valve sleeve, and the valve sleeve is limited by the limiting structure when contacting the spool. In this way, during the movement of the spool by a set distance, the sealing structure always cooperates with the valve body, so that the intermediate passage and the pilot oil cavity are in a completely sealed state, ensuring the sealing performance and preventing the occurrence of arm dropping;

[0026] (5) By providing a second spring between the valve sleeve and the spool to limit the valve sleeve between the contact spools, the structure is simple, easy to implement, and the cost is low. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a state diagram of the spool of the load-holding cartridge-type multi-way valve according to Embodiment 1 of the present invention in the middle position;

[0029] Figure 2 It is a state diagram of the spool of the load-holding cartridge-type multi-way valve according to Embodiment 1 of the present invention in contact with both the ejector rod and the valve sleeve;

[0030] Figure 3 It is a state diagram of the spool of the load-holding cartridge-type multi-way valve according to Embodiment 1 of the present invention moving to the right;

[0031] Figure 4 For Figure 3Cross-sectional view along D-D

[0032] Figure 5 It is a state diagram of the leftward movement of the spool of the load-holding cartridge multi-way valve according to Embodiment 1 of the present invention;

[0033] Figure 6 is Figure 5 Cross-sectional view along C-C;

[0034] Figure 7 It is a hydraulic schematic diagram of the load-holding cartridge multi-way valve according to Embodiment 1 of the present invention;

[0035] Figure 8 It is a diagram showing the movement relationship between the valve sleeve and the ejector rod with the spool movement according to Embodiment 1 of the present invention;

[0036] Figure 9 It is a diagram showing the relationship between the second spring force value and the spool movement according to Embodiment 1 of the present invention;

[0037] Figure 10 It is a diagram showing the relationship between the first spring and the spool movement according to Embodiment 1 of the present invention;

[0038] Figure 11 It is a schematic diagram showing the positional relationship between the valve sleeve and the ejector rod according to Embodiment 2 of the present invention.

[0039] Among them, 1. Valve body, 1-1. Inlet oil chamber, 1-2. Compensation inlet oil chamber, 1-31. First compensation outlet oil chamber, 1-32. Second compensation outlet oil chamber, 1-4. First working oil chamber, 1-5 - Second working oil chamber, 1-51. First chamber, 1-52. Second chamber, 1-6. First flow channel, 1-7. Cavity, 1-8. Second flow channel, 1-9. Third flow channel, 1-10. Intermediate channel, 1-11. Intermediate cavity, 1-12. Pilot channel, 1-13. First return oil chamber, 1-14. Second return oil chamber, 2. Spool, 3. Spring seat, 4. Fourth spring, 5. First end cover, 6. Safety valve for A working oil port, 7. Compensation valve, 8. Check valve, 9. Third spring, 10. Plug, 11. Safety valve for B working oil port, 12. Sealing ring, 13. Valve sleeve, 132. Protrusion, 14. Second spring, 15. Ejector rod, 16. First spring, 17. Second end cover. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0041] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0043] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0044] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figures with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures for the device. For example, if the device in the attached drawings is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0045] In addition, it should be noted that the use of terms such as "first", "second" etc. to define components is only for the convenience of differentiating the corresponding components. Without additional declaration, the above terms have no special meaning, and thus should not be construed as limiting the protection scope of the present invention.

[0046] Such as Figure 1 , a load-holding slice type multi-way valve, comprising:

[0047] A valve body 1, in which there are a spool hole, a working oil chamber communicating with the spool hole, an oil inlet chamber 1-1 and an oil return chamber. The oil inlet chamber 1-1 is connected to an oil inlet, and the oil return chamber is connected to an oil return port;

[0048] A spool 2, placed in the spool hole for oil circuit conversion;

[0049] A check valve hole, which communicates with one of the working oil chambers. A check valve 8 is provided in the check valve hole, and the inside of the check valve 8 has a cavity 1-7 communicating with the working oil chamber;

[0050] At least one pilot oil chamber,

[0051] An intermediate body, which is provided with a pilot channel 1-12 for communicating the pilot oil chamber with the spool hole to push the spool 2 to move and an intermediate channel 1-10 communicating with the cavity 1-7 of the check valve 8;

[0052] A switching mechanism, which is used to connect or disconnect the intermediate channel 1-10 and the pilot oil chamber. The intermediate channel 1-10 can be arranged inside the intermediate body. Of course, the switching mechanism can be a structure such as the valve body.

[0053] In the present invention, there are two working oil ports, namely the A working oil port and the B working oil port. The A working oil port and the B working oil port are respectively connected to the first chamber and the second chamber of the working oil cylinder. The first working oil chamber 1-4 and the second working oil chamber 1-5 are correspondingly arranged for the A working oil port and the B working oil port. The check valve 8 is arranged at the position of the second working oil chamber 1-5 and divides the second working oil chamber into a first chamber 1-51 and a second chamber 1-52.

[0054] The intermediate body includes a push rod 15 and a valve sleeve 13 sleeved outside the push rod 15. The pilot passage 1-12 is a central through hole arranged in the center of the push rod 15. A first elastic element for pushing the push rod 15 towards the valve core 2 is arranged between the push rod 15 and the wall of the pilot oil chamber. The first elastic element is the first spring 16. One end of the valve sleeve 13 extends into the valve core hole. The intermediate passage 1-10 is a groove arranged on the side wall of the valve sleeve 13. The groove can be arranged on the entire circular surface or a partial circular surface. The on-off structure is a sealing structure arranged at the other end of the valve sleeve 13 and cooperating with the valve body 1 to communicate or disconnect the groove from the pilot oil chamber.

[0055] The sealing structure includes a convex portion 132 arranged at the end of the valve sleeve 13.

[0056] The contact position between the sealing structure and the valve body 1 is a conical surface, and a line seal is formed between the conical surface and the edge of the valve core hole.

[0057] A sealing ring 12 is arranged between the valve sleeve 13 and the valve core hole near the valve core 2.

[0058] After the valve core 2 pushes the valve sleeve 13 and / or the push rod 15 by a set distance, the intermediate passage 1-10 communicates with the pilot oil chamber. In this way, before the oil fluid at the P port reaches the working oil port, the intermediate passage 1-10 cannot communicate with the pilot oil chamber, so as to prevent the phenomenon of arm dropping.

[0059] The specific implementation can have the following embodiments:

[0060] Embodiment 1:

[0061] In the present invention, the valve sleeve 13 is slidably connected to the push rod 15. A step for pushing the valve sleeve 13 towards the valve core 2 is arranged on the push rod 15. The groove on the valve sleeve 13 extends to the sealing structure. When the push rod 15 abuts against the valve sleeve 13 and the sealing structure of the valve sleeve 13 cooperates with the valve body 1, the end of the push rod 15 close to the valve core 2 extends beyond the end of the valve sleeve 13 close to the valve core 2, and the extended distance is L. Here, L can be equal to Figure 8 2x in, so that the valve core 2 contacts the push rod 15 first and then the valve sleeve 13. A limiting structure for limiting the valve sleeve 13 before the valve core 2 contacts the valve sleeve 13 is arranged on the valve body 1 or between the valve sleeve 13 and the push rod 15.

[0062] Embodiment 2:

[0063] The valve sleeve 13 is slidably connected to the push rod 15. A step is provided on the push rod 15 for pressing the valve sleeve 13 towards the valve core 2. When the push rod 15 abuts against the valve sleeve 13 and the sealing structure of the valve sleeve 13 cooperates with the valve body 1, as Figure 11 , the end of the valve sleeve 13 close to the valve core 2 extends beyond the end of the push rod 15 close to the valve core 2 or they are flush. The distance between the groove on the valve sleeve 13 and the sealing structure is L. The outer diameter dimension of this section of the valve sleeve 13 between the groove and the sealing structure matches the valve core hole and the valve sleeve 13 can slide in the valve core hole. This embodiment can solve the problem of oil leakage when the valve core 2 is in the middle position. However, during the process of the valve core 2 pushing the valve sleeve 13 towards the pilot oil chamber, after the sealing structure is separated from the valve body 1, a small amount of oil will flow from the gap between the valve sleeve 13 and the valve core hole to the pilot oil chamber (at this time, the middle channel 1-10 is not completely connected to the pilot oil chamber). Therefore, the sealing performance of this embodiment is not as good as that of Embodiment 1. Here, L can be equal to Figure 8 2x in, the valve core 2 first contacts the valve sleeve 13, and a limiting structure is provided on the valve body 1 or between the valve sleeve 13 and the push rod 15 for limiting the valve sleeve 13 before the valve core 2 contacts the valve sleeve 13.

[0064] Embodiment 3:

[0065] The push rod 15 and the valve sleeve 13 are integrally formed or fixedly connected. There is a distance L between the groove on the valve sleeve 13 and the protrusion 132. Here, L can be equal to Figure 8 2x in. The principle and effect of this embodiment are similar to those of Embodiment 2 and will not be elaborated here.

[0066] In Embodiment 1 and Embodiment 2, the limiting structure can be in the form of a movable stop rod or a stop block, etc. The stop rod or stop block blocks the valve sleeve 13 before the valve core 2 contacts the valve sleeve 13 and releases the valve sleeve 13 after the valve core 2 contacts the valve sleeve 13. In the present invention, the limiting structure is a second elastic element provided between the valve sleeve 13 and the push rod 15. The second elastic element is the second spring 14.

[0067] A first flow channel 1-6 is provided between the cavity 1-7 of the one-way valve 8 and the second working oil chamber 1-5. A second flow channel 1-8 and a third flow channel 1-9 are provided between the cavity 1-7 of the one-way valve 8 and the middle channel 1-10.

[0068] A pressure compensation chamber is further provided in the valve body 1. A pressure compensation valve 7 is provided in the pressure compensation chamber. A compensation inlet chamber 1-2 and a compensation outlet chamber are connected between the pressure compensation chamber and the valve core hole. A safety valve hole is provided between the working oil chamber and the return oil chamber, and a safety valve is provided in the installation valve hole.

[0069] A plug 10 is installed at the end of the one-way valve hole. A third spring 9 is provided between the cavity 1-7 of the one-way valve 8 and the plug. On both sides of the spool hole of the valve body 1, a first end cover 5 and a second end cover 17 are respectively provided. The first end cover 5 corresponds to the position of the A working oil port, and the second end cover 17 corresponds to the position of the B working oil port. A first pilot oil cavity is formed inside the first end cover 5. The first end cover 5 is provided with a pa port communicating with the first pilot oil cavity. A spring seat 3 for pressing against the spool 2 is provided inside the first pilot oil cavity. A fourth spring 4 is provided between the spring seat 3 and the first end cover 5. A second pilot oil cavity is formed inside the second end cover. The second end cover 17 is provided with a pb port communicating with the second pilot oil cavity. The push rod 15 and the valve sleeve 13 are arranged at the second pilot oil cavity.

[0070] Correspondingly, the safety valve includes an A working oil port installation valve 6 corresponding to the A working oil port and a B working oil port safety valve 11 corresponding to the B working oil port. The oil return cavity includes a first oil return cavity 1-13 corresponding to the A working oil port and a second oil return cavity 1-14 corresponding to the B working oil port. The compensated oil outlet cavity includes a first compensated oil outlet cavity 1-31 corresponding to the A working oil port and a second compensated oil outlet cavity 1-32 corresponding to the B working oil port.

[0071] Working principle:

[0072] 1) As Figure 1 , when the spool 2 is in the middle position, the sealing structure of the valve sleeve 13 cooperates with the valve body. The first cavity 1-51 of the second working oil cavity 1-5, the first flow channel 1-6, the cavity 1-7, the second flow channel 1-8, the third flow channel 1-9, and the intermediate channel 1-10 form a cavity a. The four seals of the cavity a ensure zero leakage. The first seal: the line seal between the one-way valve 8 and the valve body 1; the second seal: the line seal between the B working oil port safety valve 11 and the valve body 1; the third seal: the line seal between the valve sleeve 13 and the valve body 1; the fourth seal: the seal of the sealing ring 12 between the valve sleeve 13 and the valve body 1; zero leakage can be achieved with all four seals.

[0073] Under the action of the external load force, the pressure oil at the B working oil port acts on the upper cavity of the one-way valve 8 through the first cavity 1-51 of the second working oil cavity 1-5, the first flow channel 1-6, and the cavity 1-7. The one-way valve is reversely cut off to achieve the load holding function.

[0074] 2) Pilot pressure is applied to the pa port:

[0075] The first stage:

[0076] Under the action of the pilot pressure at the pa port, the spool 2 moves to the right and the pb port returns oil. The spool 2 pushes the push rod 15 to move to the right. When the spool 2 does not contact the valve sleeve 13, the valve sleeve 13 is pressed tightly on the valve body 1 under the action of the second spring 14, and the cavity a remains in a sealed state.

[0077] The second stage:

[0078] As Figures 2 to 4 , when the valve core 2 contacts the valve sleeve 13, the valve core 2 simultaneously pushes the valve sleeve 13 and the push rod 15 to move to the right. The cavity a is communicated with the second pilot oil cavity, and the oil returns through the pb port. The check valve 8 opens reversely. The oil in the B working oil port passes through the first cavity 1-51 of the second working oil cavity 1-5, the check valve hole, the second cavity 1-52 of the second working oil cavity 1-5, the valve core hole, and the second oil return cavity 1-14 to return to the T port. At the same time, the oil in the P port passes through the oil inlet cavity 1-1, the valve core hole, the compensation oil inlet cavity 1-2, the compensation valve 7, the first compensation oil outlet cavity 1-31, the valve core hole, and the first working oil cavity 1-4 to enter the A working oil port;

[0079] During the entire process of the first stage and the second stage, the movement relationship between the valve sleeve 13, the push rod 15 and the valve core 2, and the force value relationship between the second spring 14 and the first spring 16 and the valve core 2 are as Figures 8 to 10 , where x, y 0 、y 1 、t and y 2 are all constants, and the zero position of the valve core 2 is the middle position shown as Figure 1 .

[0080] 3) Apply pilot pressure to the pb port:

[0081] As Figures 5 to 6 , the pressure oil at the pb port passes through the second end cover 17 and the pilot channel 1-12 and enters the intermediate cavity 1-11 between the valve sleeve 13 and the valve core 2, pushing the valve core 2 to move left. The pressure oil at the P port passes through the oil inlet cavity 1-1, the valve core hole, the compensation oil inlet cavity 1-2, the compensation valve 7, the second compensation oil outlet cavity 1-32, the valve core hole, and the second cavity 1-52 of the second working oil cavity 1-5 and acts on the check valve 8, pushing the check valve 8 to open forward. The oil passes through the check valve 8 and enters the B working oil port through the first cavity 1-51 of the second working oil cavity 1-5 (the oil in the cavity 1-7 of the check valve 8 enters the first cavity 1-51 of the second working oil cavity 1-5 through the first flow channel 1-6). The oil in the A working oil port passes through the first working oil cavity 1-4, the valve core hole, and the first oil return cavity 1-13 to enter the T port.

[0082] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A load-holding plate-type multi-way valve, characterized in that : it includes a valve body (1), a spool hole and a working oil chamber, an oil inlet chamber (1-1) and an oil return chamber communicating with the spool hole are arranged in the valve body (1), the oil inlet chamber (1-1) is connected to an oil inlet, and the oil return chamber is connected to an oil return port; a spool (2), the spool (2) is placed in the spool hole for oil circuit conversion; a check valve hole, the check valve hole communicates with one of the working oil chambers, a check valve (8) is arranged in the check valve hole, and a cavity (1-7) communicating with the working oil chamber is arranged inside the check valve (8); at least one pilot oil chamber, an intermediate body, the intermediate body is provided with a pilot channel (1-12) for communicating the pilot oil chamber with the spool hole to push the spool (2) to move and an intermediate channel (1-10) communicating with the cavity (1-7) of the check valve (8); a switching mechanism, the switching mechanism is used to connect or disconnect the intermediate channel (1-10) and the pilot oil chamber; the intermediate body includes a push rod (15) and a valve sleeve (13) sleeved outside the push rod (15), the pilot channel (1-12) is a central through hole arranged in the center of the push rod (15), and a first elastic element for pushing the push rod (15) towards the spool (2) is arranged between the push rod (15) and the wall of the pilot oil chamber. One end of the valve sleeve (13) extends into the spool hole, the intermediate channel (1-10) is a groove arranged on the side wall of the valve sleeve (13), and the switching mechanism is a sealing structure arranged at the other end of the valve sleeve (13) and cooperating with the valve body (1) to connect or disconnect the groove and the pilot oil chamber.

2. A load-holding plate-type multi-way valve according to claim 1, characterized in that: the sealing structure includes a convex portion (132) arranged at the end of the valve sleeve (13).

3. A load-holding plate-type multi-way valve according to claim 2, characterized in that: the contact position between the sealing structure and the valve body (1) is a conical surface.

4. A load-holding plate-type multi-way valve according to claim 3, characterized in that: a sealing ring (12) is arranged between the valve sleeve (13) and the spool hole near the spool (2).

5. A load-holding plate-type multi-way valve according to claim 3, characterized in that: after the spool (2) pushes the valve sleeve (13) and / or the push rod (15) by a set distance, the intermediate channel (1-10) communicates with the pilot oil chamber.

6. A load-holding plate-type multi-way valve according to claim 5, characterized in that: The described valve sleeve (13) is slidably connected to the push rod (15). A step is provided on the push rod (15) for pressing the valve sleeve (13) towards the valve core (2). The groove on the valve sleeve (13) extends to the sealing structure. When the push rod (15) abuts against the valve sleeve (13) and the sealing structure of the valve sleeve (13) cooperates with the valve body (1), the end of the push rod (15) close to the valve core (2) extends beyond the end of the valve sleeve (13) close to the valve core (2), so that the valve core (2) contacts the push rod (15) first and then the valve sleeve (13). A limiting structure is provided on the valve body (1) or between the valve sleeve (13) and the push rod (15) for limiting the valve sleeve (13) before the valve core (2) contacts the valve sleeve (13).

7. A load-holding wafer multi-way valve according to claim 6, characterized in that: The limiting structure is a second elastic element provided between the valve sleeve (13) and the push rod (15).

8. A load-holding wafer multi-way valve according to claim 2, characterized in that: The push rod (15) and the valve sleeve (13) are integrally formed or fixedly connected, and there is a distance between the groove of the valve sleeve (13) and the protrusion (132).

9. A load-holding wafer multi-way valve according to claim 1, characterized in that: A pressure compensation chamber is further provided in the valve body (1). A pressure compensation valve (7) is provided in the pressure compensation chamber. A compensation oil inlet chamber (1-2) and a compensation oil outlet chamber are connected between the pressure compensation chamber and the valve core hole. A safety valve hole is provided between the working oil chamber and the oil return chamber, and a safety valve is provided in the safety valve hole.

Images