CN111828419B

CN111828419B - Hydraulic reversing valve

Info

Publication number: CN111828419B
Application number: CN201910322321.6A
Authority: CN
Inventors: 孔德强; 胡启辉; 贺广济; 李瑞锋
Original assignee: Bosch Rexroth Changzhou Co Ltd
Current assignee: Bosch Rexroth Changzhou Co Ltd
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2024-03-12
Anticipated expiration: 2039-04-22
Also published as: CN111828419A

Abstract

The utility model provides a hydraulic pressure switching-over valve, includes the valve body and sets up the valve rod of valve body, the valve body is formed with a plurality of runners, intercommunication a plurality of runner's valve opening and with the oil inlet, the oil return opening and the first work hydraulic fluid port of corresponding runner intercommunication, oil inlet and the first work hydraulic fluid port on the valve opening are adjacent to be set up and are separated through first valve opening section, the valve rod has can be relative first valve opening section gliding first piston section and make the hydraulic pressure switching-over valve forms the oil inlet does not communicate the cut-off position of first work hydraulic fluid port and the switch-on position of oil inlet intercommunication first work hydraulic fluid port, first piston section in cut-off position have with first valve opening section complex first sealed section, first interior runner has been seted up to the valve rod, when the hydraulic pressure switching-over valve is in cut-off position, first interior runner has be located first opening of first sealed section and with the second opening of oil return opening intercommunication.

Description

Hydraulic reversing valve

Technical Field

The present application relates to the field of hydraulic pressure, and in particular to the field of hydraulically commutated valves.

Background

The valve hole and the valve rod of the hydraulic valve are sealed in a sliding manner, which is in clearance fit, and internal leakage is inevitably caused, and even if the valve is closed, oil pressure is generated by leaked oil, so that adverse effects can be generated. Referring to fig. 1 and 2, fig. 1 shows a hydraulic cylinder driving oil path provided by a three-position four-way valve, and fig. 2 shows a schematic cross-sectional view of a valve rod 200 of the three-position four-way valve in a middle position (i.e. a cut-off position and a pressure maintaining position). Due to the influence of the gap and the pressure difference, the oil inlet P leaks to the first working oil port a and the second working oil port B, respectively, while the pressure acting areas a and B on the piston in the hydraulic cylinder are different, the pressure will generate different forces on both sides of the piston and cause the hydraulic cylinder to drift slowly and undesirably. In the prior art, the problem of hydraulic cylinder drift is generally solved by additionally arranging a hydraulic lock or arranging a pressure relief switch oil way at the oil inlet. But these schemes are not only costly, but also relatively complex in construction.

Accordingly, there is a need for an improvement to overcome the technical problems of the prior art.

Disclosure of Invention

The application aims to solve the problem that hydraulic oil leaks from an oil inlet to a closed adjacent working oil port.

In order to solve the technical problem, the application provides a hydraulic reversing valve, including the valve body with set up the valve rod of valve body, the valve body is formed with a plurality of runners, intercommunication a plurality of runner's valve opening and with the oil inlet, oil return port and the first work hydraulic fluid port of corresponding runner intercommunication, oil inlet and the first work hydraulic fluid port on the valve opening are adjacent to be set up and separate through first valve opening section, the valve rod has can be relative the gliding first piston section of first valve opening section and makes the hydraulic reversing valve forms the cut-off position that the oil inlet does not communicate first work hydraulic fluid port and the conducted position that the oil inlet communicates first work hydraulic fluid port, first piston section have in the cut-off position with first valve opening section complex first sealed section, the valve rod has seted up first interior runner, works as when the hydraulic reversing valve is in the cut-off position, first interior runner has and is located first sealed section's first opening and with the second opening that returns the oil port intercommunication. Because the first seal section is the requisite way for the oil inlet to leak oil to the working oil port, the technical scheme is that the inner runner which is communicated with the first seal section and the oil return port is arranged on the valve rod, the oil leak flowing to the working oil port is skillfully intercepted and guided in the way, and possible adverse effects are avoided.

Drawings

The present application will be more fully understood with reference to the following detailed description of specific embodiments taken in conjunction with the accompanying drawings. Wherein:

FIG. 1 is a schematic diagram of a hydraulic cylinder driving oil path in the prior art;

FIG. 2 shows a schematic cross-sectional view of the prior art hydraulic reversing valve of FIG. 1 in a closed position;

FIG. 3 shows a schematic cross-sectional view of the hydraulic reversing valve of the present application in a closed position;

FIG. 4 shows a schematic cross-sectional view of the hydraulic reversing valve of the present application in a conducting position;

fig. 5 shows a schematic perspective view of a valve rod of the hydraulic reversing valve of the present application.

Detailed Description

Embodiments of the hydraulic reversing valve 100 of the present application are described in detail below with reference to fig. 3-5.

Referring to fig. 3, the hydraulic directional valve 100 includes a valve body 10 and a valve rod 20 assembled to the valve body 10, the valve body 10 is formed with a plurality of flow passages 101, a valve hole 102 communicating with the plurality of flow passages 101, and an oil inlet P, an oil return port T and a first working port a communicating with the corresponding flow passages, the valve rod 20 is capable of moving axially in the valve hole 102 to conduct or close the corresponding flow passages, so that the hydraulic directional valve 100 is switched between different working positions, the oil inlet P and the first working port a on the valve hole 102 are disposed adjacent to each other and separated by a first valve hole section 1021, the valve rod 20 has a first piston section 201 slidably sealed or opened with respect to the first valve hole section 1021 and forms a closed position (i.e., a middle position in the present embodiment) where the oil inlet P is not communicated with the first working port a, and a conducting position (i.e., a left position or a right position in the present embodiment) where the oil inlet P is communicated with the first working port a, the first piston section 201 has a first flow passage 20a and a first valve hole section 2011 a is disposed in the closed position where the valve rod 20 has a first flow passage 20a is in communication with the first flow passage 20 a. Because the first seal segment 2011 is the necessary path for oil leakage from the oil inlet to the working oil port, the technical scheme skillfully intercepts and guides the oil leakage flowing to the working oil port in the way by arranging the inner runner which is communicated with the first seal segment and the oil return port on the valve rod, thereby avoiding possible adverse effects. As shown in fig. 5, since the first opening 20aa is two small openings at two radial ends, the first sealing section 2011 is provided with a ring groove 2012, and the first opening 20aa of the first inner flow passage 20a is communicated with the ring groove 2012, so as to intercept and guide the leakage of the entire first sealing section 2011. Likewise, a ring groove (not shown) may be provided on the second opening 20ab side to achieve communication with the oil return port T in the entire circumferential direction.

Referring to fig. 4 and 5, the first opening 20aa or the second opening 20ab of the first inner flow passage 20a is sealed when the valve stem 20 is axially moved to other working positions (the seal mentioned herein is a seal in a general sense, not an ideal seal because the present application relates to leakage of hydraulic oil in a sealed state). Since the hydraulic directional control valve 100 is not only in the off position but the first inner flow passage 20a is mainly operated in the off position, the energy loss can be reduced by matching the seal between the rest of the operating positions, particularly, the situation that the oil inlet P is directly connected to the oil return port T is avoided. The first piston section 201 has a first piston end surface 201a axially movable in the first valve hole section 1021, the first opening 20aa of the first inner flow passage 20a is a radial circular hole disposed near the first piston end surface 201a, and a ratio of a distance from the first piston end surface 201a to a central axis of the first opening 20aa to an axial length (not labeled) of the first valve hole section 1021 is between 1/5 and 4/5. The first opening 20aa is close to the first piston end surface 201a, which not only ensures a sufficient sealing distance of the first sealing section 2011, but also facilitates compact design of the valve stem 20. The first inner flow passage 20a comprises a connecting flow passage formed from the end of the valve rod 20, the valve rod 20 further comprises a pin hole 205 which is radially communicated with the connecting flow passage, the diameter of the pin hole 205 is larger than or equal to that of the connecting flow passage, and a pin sealing piece 206 is assembled on the pin hole 205 to seal the opening of the connecting flow passage at the end of the valve rod 20. Because the valve rod 20 is assembled in the valve body 10, the end part structure has an influence on the working position and the working performance of the reversing valve, and the blocking of a connecting flow passage can be realized in the radial direction by arranging the pin holes 205, and the structure of the end part of the valve rod 20 is not influenced.

The above is a basic embodiment for implementing the inventive concept. In particular, to the three-position four-way valve shown in fig. 3 and 4, the valve holes 102 on two sides of the oil inlet P are symmetrically arranged, that is, the valve holes 102 are provided with second working oil ports B (reference numerals a and B refer to working oil ports generally and not only to working oil inlets and working oil returns which are designated by hydraulic pressure) which are arranged adjacent to the oil inlet P and are partitioned by the second valve hole sections 1022, the first working oil ports a and the second working oil ports B are respectively positioned on two sides of the oil inlet P, the valve rod 20 is provided with second piston sections 202 which can be slidably sealed or opened relative to the second valve hole sections 1022, and the hydraulic directional valve 100 is provided with a closed position where the oil inlet P is not communicated with the second working oil ports B, and a conducting position where the oil inlet P is communicated with the second working oil ports B, the second piston sections 202 are provided with second sealing sections 2021 which are matched with the second valve hole sections 1022, and the second inner flow passages 20B are provided with the second sealing passages 20B which are positioned in the first sealing sections T and the second sealing ports 20B when the hydraulic directional valve 100 is positioned in the closed position. Based on the above-mentioned symmetrical design, the first inner flow passage 20a and the second inner flow passage 20B are respectively configured in the corresponding matched sealing sections 2011, 2021, and jointly bear the interception and guiding of the leaked oil flowing to the working oil ports a, B, so that possible adverse effects are avoided.

The second piston section 202 has a second piston end surface 202a axially movable in the second valve hole section 1022, the first opening 20ba of the second inner flow passage 20b is a radial circular hole disposed near the second piston end surface 202a, and a ratio of a distance from the second piston end surface 202a to a central axis of the first opening 20ba to an axial length of the second valve hole section 1022, which is not indicated, is between 1/5 and 4/5, and the design of the portion is identical to the designs of the first piston section 201 and the first valve hole section 1021. The oil return port T comprises a first oil return port T1 and a second oil return port T2, the first oil return port T1 is arranged on one side of the first working oil port A, which is far away from the oil inlet P, and the first inner runner 20a is communicated with the first oil return port T1; the second oil return port T2 is disposed at a side of the second working oil port B away from the oil inlet P, and the second inner flow passage 20B is communicated with the second oil return port T2. The leakage oil of the first working oil port a is collected to the adjacent first oil return port T1, and the leakage oil of the second working oil port B is collected to the adjacent second oil return port T2, so that the design of the internal flow path can be simplified, and possible confusion and interference generated during the switching of the working positions can be avoided. The fact that the first and second inner flow passages 20a, 20b do not communicate within the valve stem 20 is also for this purpose, and of course, if the arrangement is carefully designed, it is not precluded that the leaked oil communicates with the oil return port at the distal end, and that the first and second inner flow passages 20a, 20b communicate with each other.

The above detailed description is illustrative of the present application and is not intended to be limiting. The above embodiments are specific to three-position four-way reversing valves, and in other embodiments, reversing valves having the basic architecture of the claims are applicable. In summary, various changes and modifications may be made by one of ordinary skill in the relevant art without departing from the scope of the present application, and therefore, all equivalent technical solutions are intended to fall within the scope of the present application, which is defined by the claims.

Claims

1. The utility model provides a hydraulic pressure switching-over valve (100), includes valve body (10) and group locate valve rod (20) of valve body (10), valve body (10) are formed with a plurality of runners (101), intercommunication valve opening (102) of a plurality of runners (101) and with oil inlet (P), oil return port (T) and first work hydraulic fluid port (A) of corresponding runner intercommunication, oil inlet (P) and first work hydraulic fluid port (A) on valve opening (102) set up adjacently and separate through first valve opening section (1021), valve rod (20) have can be relative first valve opening section (1021) gliding first piston section (201) and make hydraulic pressure switching-over valve (100) form the cut-off position of oil inlet (P) non-intercommunication first work hydraulic fluid port (A) and the conducting position of oil inlet (P) intercommunication first work hydraulic fluid port (A), first piston section (201) have in the cut-off position with first valve opening section (1021) complex first seal section (2011), its characterized in that: the valve rod (20) is provided with a first inner flow passage (20 a), and when the hydraulic reversing valve (100) is in a closing position, the first inner flow passage (20 a) is provided with a first opening (20 aa) positioned at the first sealing section (2011) and a second opening (20 ab) communicated with the oil return port (T).

2. The hydraulic reversing valve (100) of claim 1, wherein the first opening (20 aa) or the second opening (20 ab) of the first inner flow passage (20 a) is sealed in the on position.

3. The hydraulic reversing valve (100) of claim 1, wherein the first piston section (201) has a first piston end face (201 a) axially movable in the first valve bore section (1021), the first opening (20 aa) of the first inner flow passage (20 a) is a radial circular bore disposed proximate the first piston end face (201 a), and a ratio of a distance of the first piston end face (201 a) to a central axis of the first opening (20 aa) to an axial length of the first valve bore section (1021) is between 1/5 and 4/5.

4. The hydraulic reversing valve (100) of claim 1, wherein the first inner flow passage (20 a) includes a connecting flow passage opening from an end of the valve stem (20), the valve stem (20) further including a pin bore (205) in radial communication with the connecting flow passage, the pin bore (205) being assembled with a pin seal (206) to block an opening of the connecting flow passage at the end of the valve stem (20).

5. The hydraulic reversing valve (100) of claim 1, wherein the valve bore (102) has a second working port (B) disposed adjacent to the oil inlet (P) and separated by a second valve bore section (1022), the first working port (a) and the second working port (B) are disposed on opposite sides of the oil inlet (P), the valve stem (20) has a second piston section (202) slidable relative to the second valve bore section (1022) and such that the hydraulic reversing valve (100) forms a closed position in which the oil inlet (P) is not in communication with the second working port (B) and an open position in which the oil inlet (P) is in communication with the second working port (B), the second piston section (202) has a second seal section (2021) in the closed position that mates with the second valve bore section (1022), and the valve stem (20) defines a second inner flow passage (20B) having a second seal section (2021) in the closed position in which the second inner flow passage (20B) is in communication with the second opening (bb) of the second reversing section (20).

6. The hydraulic reversing valve (100) of claim 5, wherein the first opening (20 ba) or the second opening (20 bb) of the second inner flow passage (20 b) is sealed in the on position.

7. The hydraulic reversing valve (100) of claim 5, wherein the second piston section (202) has a second piston end face (202 a) axially movable in the second valve bore section (1022), the first opening (20 ba) of the second inner flow passage (20 b) is a radial circular bore disposed proximate the second piston end face (202 a), and a ratio of a distance of the second piston end face (202 a) to a central axis of the first opening (20 ba) to an axial length (not labeled) of the second valve bore section (1022) is between 1/5 and 4/5.

8. The hydraulic reversing valve (100) according to claim 5, wherein the oil return port (T) includes a first oil return port (T1) and a second oil return port (T2), the first oil return port (T1) is provided at a side of the first working oil port (a) away from the oil inlet port (P), and the first inner flow passage (20 a) communicates with the first oil return port (T1) in a blocking position; the second oil return port (T2) is arranged on one side, far away from the oil inlet (P), of the second working oil port (B), and the second inner runner (20B) is communicated with the second oil return port (T2) at a cut-off position.

9. The hydraulic reversing valve (100) of claim 5, wherein the first internal flow passage (20 a) and the second internal flow passage (20 b) are not in communication within the valve stem (20).

10. The hydraulic reversing valve (100) of any of claims 1 to 6, wherein the first sealing section (2011) is provided with a ring groove (2012) with which the first opening (20 aa) of the first inner flow passage (20 a) communicates.