CN114688118A - Load-sensitive multi-way valve reversing linkage - Google Patents

Abstract

A load-sensitive multi-way valve reversing linkage comprises a valve body, wherein a compensation valve and a reversing valve are formed in the valve body, the compensation valve comprises a compensation valve hole formed in the valve body and a compensation valve core arranged in the compensation valve hole, a compensation valve oil inlet cavity, a compensation valve oil outlet cavity, a spring side control cavity and a springless side control cavity are formed in the compensation valve hole, the reversing valve comprises a reversing valve hole formed in the valve body and a reversing valve core arranged in the reversing valve hole, the reversing valve core controls the communication relation among a main oil inlet cavity, a first working oil cavity, a second working oil cavity, a first oil return cavity, a second oil return cavity and a first load-sensitive feedback pressure tapping hole and a second load-sensitive feedback pressure tapping hole which are formed in the reversing valve hole, and the compensation valve oil outlet cavity is communicated with the main oil inlet cavity; the load-sensitive multi-way valve reversing linkage also comprises a feedback oil path formed in the valve body, and the feedback oil path is used for communicating one of the first load-sensitive feedback pressure taking port and the second load-sensitive feedback pressure taking port with the spring side control cavity according to the position of the reversing valve core in the reversing valve hole.

Description

Load-sensitive multi-way valve reversing linkage

Technical Field

The invention relates to a multi-way valve reversing connector, in particular to a load-sensitive multi-way valve reversing connector which can be used for a hydraulic system.

Background

In the prior art, the operation of a traveling machine including an engineering vehicle needs to be completed by the compound movement of a plurality of hydraulic actuators, so that a plurality of hydraulic directional control valves are needed to control the movement speed and direction of each actuator. The multi-way valve is a combination of reversing valves capable of controlling a plurality of hydraulic actuators, and is a multifunctional integrated valve which takes more than two reversing valves as main bodies and integrates the reversing valves, a one-way valve, a safety valve and a shuttle valve into a whole. A load-sensitive multi-way valve is a common multi-way valve, which is provided with a compensation valve such that when each actuator is operated, the operating flow is only dependent on the spool opening and not on the load pressure. Like other multi-way valves, load sensitive multi-way valves typically include a head-to-tail connection, a tail-to-tail connection, and a reversing connection.

However, in the conventional load-sensitive multi-way valve reversing connection, a relatively complex structural design is adopted to realize a desired function, so that the load-sensitive multi-way valve reversing connection is relatively large in size and high in manufacturing cost.

The application provides a novel sensitive multiple unit valve switching-over antithetical couplet of load with structural design who simplifies, can reduce the volume of the sensitive multiple unit valve switching-over antithetical couplet of load when improving working property, reduces manufacturing cost. In addition, the reversing union of the application can improve the power density of the valve bank and can meet the application of a proportional valve bank under the condition of narrow space.

Disclosure of Invention

The invention provides a load-sensitive multi-way valve reversing linkage, which comprises a valve body, wherein a compensation valve and a reversing valve are formed in the valve body, the compensation valve comprises a compensation valve hole formed in the valve body and a compensation valve core arranged in the compensation valve hole, a compensation valve oil inlet cavity, a compensation valve oil outlet cavity, a spring side control cavity and a springless side control cavity are formed in the compensation valve hole, the reversing valve comprises a reversing valve hole formed in the valve body and a reversing valve core arranged in the reversing valve hole, the reversing valve core controls the communication relationship among a main oil inlet cavity, a first working oil cavity, a second working oil cavity, a first oil return cavity, a second oil return cavity, a first load-sensitive feedback pressure taking port and a second load-sensitive feedback pressure taking port formed in the reversing valve hole, and the compensation valve oil outlet cavity is communicated with the main oil inlet cavity; the load-sensitive multi-way valve reversing linkage also comprises a feedback oil path formed in the valve body, and the feedback oil path is used for communicating one of the first load-sensitive feedback pressure tapping and the second load-sensitive feedback pressure tapping with the spring-side control cavity according to the position of the reversing valve core in the reversing valve hole.

According to one aspect of the invention, the valve body is provided with an oil inlet, a first working oil port, a second working oil port, a first oil return port and a second oil return port which are communicated with the outside of the valve body, wherein the oil inlet is communicated with the oil inlet cavity of the compensation valve, the first working oil port and the second working oil port are respectively communicated with the first working oil cavity and the second working oil cavity, and the first oil return port and the second oil return port are respectively communicated with the first oil return cavity and the second oil return cavity.

According to one aspect of the invention, the first oil return cavity, the first load-sensitive feedback pressure tapping, the first working oil cavity, the main oil inlet cavity, the second working oil cavity, the second load-sensitive feedback pressure tapping and the second oil return cavity are sequentially arranged in the reversing valve hole along the axial direction.

According to one aspect of the invention, when the reversing valve core is in the middle position, the main oil inlet cavity is disconnected from both the first working oil cavity and the second working oil cavity, the first load-sensitive feedback pressure tapping is communicated with the first oil return cavity, and the second load-sensitive feedback pressure tapping is communicated with the second oil return cavity; when the reversing valve is in a first working position, the reversing valve core moves to a first side, the main oil inlet cavity is communicated with the first working oil cavity and the first load sensitive feedback pressure taking port, and the second working oil cavity and the second load sensitive feedback pressure taking port are communicated with the second oil return cavity; when the reversing valve is located at a second working position, the reversing valve core moves towards a second side, the main oil inlet cavity is communicated with the second working oil cavity and the second load-sensitive feedback pressure taking port, and the first working oil cavity and the first load-sensitive feedback pressure taking port are communicated with the first oil return cavity.

According to one aspect of the invention, the load-sensitive multi-way valve reversing linkage further comprises a shuttle valve arranged in the feedback oil path, and the shuttle valve feeds the larger pressure of the first load-sensitive feedback pressure taking port and the second load-sensitive feedback pressure taking port to the spring-side control cavity.

According to one aspect of the invention, the feedback oil path comprises a first feedback hole communicating the first load-sensitive feedback pressure tapping port to the shuttle valve, a second feedback hole communicating the second load-sensitive feedback pressure tapping port to the shuttle valve, and a third feedback hole communicating the shuttle valve to the spring-side control chamber, a plane where the compensation spool and the reversing spool are located is defined as a reference plane, the plane where the first feedback hole and the second feedback hole are located is perpendicular to the reference plane, and the third feedback hole extends substantially parallel to the main reference plane.

According to one aspect of the invention, the shuttle valve comprises: a shuttle valve cavity formed in the valve body, the shuttle valve cavity being connected to the first feedback hole and extending in a direction of the first feedback hole; the sleeve is fixedly arranged in the shuttle valve cavity, an inner step portion is arranged on one side, facing the first feedback hole, of the sleeve, a radial opening communicated with the second feedback hole is arranged on the side wall of the sleeve, and a third feedback hole is communicated to the shuttle valve cavity between the first feedback hole and the radial opening and is not blocked by the sleeve; a valve element located between the first feedback hole and the inner step of the sleeve and movable under the action of higher pressure in the first feedback hole and the second feedback hole to close the first feedback hole or the inner step to communicate the second feedback hole or the first feedback hole and the third feedback hole, respectively.

In accordance with one aspect of the invention, a first annular pressure tap groove in communication with the first load sensitive feedback pressure tap and a second annular pressure tap groove in communication with the second load sensitive feedback pressure tap are disposed in the reversing valve bore.

According to one aspect of the invention, when the reversing valve core is in the middle position, the first load-sensitive feedback pressure taking port is communicated with the first oil return cavity through the first annular pressure taking groove and a first throttling groove on the reversing valve core, and the second load-sensitive feedback pressure taking port is communicated with the second oil return cavity through the second annular pressure taking groove and a second throttling groove on the reversing valve core.

According to one aspect of the invention, a first balance groove is provided locally in the inner wall of the reversing valve bore adjacent the first annular pickup groove, the sum of the axial dimensions of the first annular pickup groove and the first balance groove being greater than the axial dimension of the first load sensitive feedback pickup port, and a symmetrical second balance groove is provided in the inner wall of the reversing valve bore at a location diametrically opposite the first balance groove.

According to an aspect of the present invention, both the first balance groove and the second balance groove are provided in a crescent shape as viewed in the axial direction of the direction spool, and the depth of the first balance groove and the second balance groove is smaller than the depth of the first annular pressure taking groove.

According to one aspect of the invention, a third balance groove is provided locally in the inner wall of the reversing valve bore adjacent the second annular pressure taking groove, the sum of the axial dimensions of the second annular pressure taking groove and the third balance groove being greater than the axial dimension of the second load sensitive feedback pressure taking port, and a symmetrical fourth balance groove is provided in the inner wall of the reversing valve bore at a location diametrically opposite the third balance groove.

According to an aspect of the present invention, both the third balance groove and the fourth balance groove are disposed in a crescent shape as viewed in the axial direction of the direction spool, and the depth of the third balance groove and the fourth balance groove is smaller than the depth of the second annular pressure taking groove.

According to one aspect of the invention, the load-sensitive multi-way valve reversing link further comprises: the two reversing valve springs are respectively arranged in reversing valve spring cavities of the reversing valve hole and positioned at two ends of the reversing valve core, and the two spring seats are respectively positioned between the reversing valve core and the two reversing valve springs, the reversing valve springs apply thrust to the reversing valve core through the spring seats, and when the reversing valve core is positioned at the middle position, the two spring seats are abutted against axial stop parts arranged in the reversing valve hole.

According to an aspect of the present invention, a connection passage that respectively fluidly connects the first oil return chamber and the second oil return chamber to the corresponding spring chamber of the reversing valve is provided between both ends of the reversing valve spool and the spring seat, and the connection passage includes an oil passage provided on an end surface or inside of the reversing valve spool and a gap provided between the end of the reversing valve spool and the spring seat.

According to one aspect of the invention, a spring seat includes: a first section extending axially and capable of abutting against a stop; a second section extending radially inward from the first section for abutting against an end of the diverter spool; and a third section located radially inward of the second section and extending radially, the third section being spaced from the end of the diverter spool when the second section abuts the end of the diverter spool, forming a portion of the gap; and a fourth section extending axially from the third section, the reversing valve spring being sleeved outside the fourth section and abutting against the third section.

According to one aspect of the invention, the diverter spool includes a central projection extending axially from both ends, the central projection being received in and spaced from the fourth section forming a portion of the gap when the second section abuts the end of the diverter spool.

According to one aspect of the invention, a connecting channel for connecting the first oil return cavity and the second oil return cavity to the corresponding reversing valve spring cavity is respectively arranged between the two ends of the reversing valve core and the spring seat, the connecting channel comprises a surface oil channel axially extending on the surface of the end part of the reversing valve core, the load-sensitive multi-way valve reversing link further comprises a mandril fixed in the valve body, and the end part of the mandril extends into the surface oil channel, so that the reversing valve core is allowed to axially move while the reversing valve core is prevented from rotating.

According to one aspect of the invention, a pushrod is also provided in the valve body, the end of the pushrod being received in an axially extending retaining groove in the end of the diverter spool to allow axial movement of the diverter spool while preventing rotation of the diverter spool.

According to one aspect of the invention, the springless side control chamber of the compensator valve communicates to the compensator outlet chamber through a channel located inside the compensator valve spool that moves in response to a pressure differential between the spring side control chamber and the springless side control chamber.

Drawings

The invention will be described in further detail with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a load sensitive multiplex valve including a load sensitive multiplex valve trip link according to an exemplary embodiment of the present invention;

FIG. 2 is a perspective view of the load sensitive multiplex valve reversing link shown in FIG. 1;

FIG. 3A is a cross-sectional view of the reversing link with the reversing valve spool of the reversing link in a neutral position taken along line A-A in FIG. 2, the plane of line A-A being a horizontal plane;

FIG. 3B is a cross-sectional view of the diverter link taken along line B-B in FIG. 2 at a neutral position of the diverter spool, the plane of line B-B being 90 relative to the plane of line A-A;

FIG. 3C is a cross-sectional view of the diverter link taken along line C-C in FIG. 2 at a neutral position of the diverter spool, the plane of line C-C being at 45 relative to the plane of line A-A;

FIG. 3D is an enlarged view of the dashed circle portion of FIG. 3B showing the end of the diverter spool;

FIG. 4A is a cross-sectional view of the diverter link taken along line A-A in FIG. 2 with the diverter spool in a first operating position;

FIG. 4B is a cross-sectional view of the diverter link taken along line B-B in FIG. 2 with the diverter spool in the first operating position;

FIG. 4C is a cross-sectional view of the diverter link taken along line C-C in FIG. 2 with the diverter spool in the first operating position;

FIG. 5A is a cross-sectional view of the diverter link taken along line A-A in FIG. 2 with the diverter spool in a second operating position;

FIG. 5B is a cross-sectional view of the diverter link taken along line B-B in FIG. 2 with the diverter spool in a second operating position;

FIG. 5C is a cross-sectional view of the diverter link taken along line C-C in FIG. 2 with the diverter spool in a second operating position;

FIG. 6A is a side view of the reversing link of FIG. 2;

FIG. 6B is a cross-sectional view taken along line E-E in FIG. 6A;

FIG. 6C is an enlarged view of the dashed circle portion in FIG. 6B;

FIG. 6D is a partial cross-sectional perspective view taken along line F-F in FIG. 6A;

FIG. 6E is an enlarged view of the dashed circle portion G in FIG. 6D;

fig. 6F is an enlarged view of a dotted circle portion H in fig. 6D; and

fig. 7 is a perspective view of a diverter valve cartridge according to an exemplary embodiment of the present invention.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention.

Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in diagram form to simplify the drawing.

As shown in fig. 1, the load sensitive multiplex valve 1000 includes: a beginning-of-line 110, a tail-of-line 120, and a plurality of commutation strings 150 connected in series between the beginning-of-line 110 and the tail-of-line 120. The reversing link 150 is provided with a connecting hole 21 (see fig. 2) for a bolt to pass through to connect the reversing link 150 between the lead link 110 and the tail link 120.

The lead 110 includes lead ports 114, 115 for receiving and feeding fluid, such as hydraulic oil, to and from the directional link 150 and for discharging fluid from the directional link 1000, and the tail 120 for providing a fluid seal against the directional link 150, the lead 110 and tail 120 being located on opposite sides of the directional link 150.

The specific structure of the load-sensitive multi-way valve reversing link 150 will be described below by taking a single reversing link 150 as an example. As shown in fig. 2, the valve body 100 is further provided with: an oil inlet 24 through which working hydraulic oil from one of the lead ports 114 and 115 enters the valve body 100; a first working oil port 2 and a second working oil port 3, one of the first working oil port 2 and the second working oil port 3 receiving the hydraulic fluid from the oil inlet 24 and feeding the fluid to the load while the reversing valve is driven, and the other of the first working oil port 2 and the second working oil port 3 receiving the fluid from the load and feeding the fluid to the corresponding oil return port; and a first oil return port 22 and a second oil return port 23, each communicating to the other of the union ports 114 and 115. The valve body 100 is further provided with holes 19 and 20 respectively located near the working oil ports 2 and 3, and the holes are used for installing overflow valves for releasing overpressure of the first working oil port 2 and the second working oil port 3, and the overflow valves are common elements and are not described herein again.

As shown in fig. 3B, a compensation valve and a direction valve are formed in the valve body 100 of the direction change coupling 150. The compensation valve includes a compensation valve hole 17 formed in the valve body 100, and a compensation valve spool 171 disposed in the compensation valve hole 17, in which a compensation valve oil inlet chamber 177, a compensation valve oil outlet chamber 178, a spring-side control chamber 172, and a no-spring-side control chamber 175 are formed in the compensation valve hole 17. One end of the springless side control chamber 175 is sealed by a seal 176. Hydraulic oil from one of the ports, e.g., port 114, communicates with the compensating valve oil inlet chamber 177 via the oil inlet port 24, enters the compensating valve bore 17 through the compensating valve oil inlet chamber 177, and then exits the compensating valve bore 17 through the compensating valve oil outlet chamber 178 to be fed to the directional control valve. The unsprung-side control chamber 175 communicates through a passage 179 in the compensator spool 171 to a compensator outlet chamber 178. A spring 173 is provided in the spring-side control chamber 172 to apply an urging force to the compensator spool 171, and a load feedback pressure to be described later is also led to the spring-side control chamber 172. The compensator spool 171 moves in response to the pressure difference between the spring-side control chamber 172 and the unsprung-side control chamber 175 to achieve balance between the pressure in the spring-side control chamber 172 and the pressure in the unsprung-side control chamber 175, thereby adjusting the position of the compensator spool 171 in the compensator valve hole 17, and thus the compensator spool 171 can adjust the pressure difference between the main oil supply chamber 1 of the selector valve and the first and second working oil chambers 6 and 10 (see below), thereby achieving flow rate adjustment.

As shown in fig. 3A to 3C, the direction valve includes a direction valve hole 5 formed in the valve body 100, and a direction valve spool 4 disposed in the direction valve hole 5. In the reversing valve hole 5, a first oil return cavity 9, a first load-sensitive feedback pressure tapping 7, a first working oil cavity 6, a main oil inlet cavity 1, a second working oil cavity 10, a second load-sensitive feedback pressure tapping 11 and a second oil return cavity 103 are sequentially arranged along the axial direction. That is, the first load-sensitive feedback pressure taking port 7 is located between the first oil return chamber 9 and the first working-oil chamber 6, and the second load-sensitive feedback pressure taking port 11 is located between the second oil return chamber 103 and the second working-oil chamber 10. A communication oil duct is further provided in the valve body 100, so that the main oil inlet chamber 1 is communicated with the compensation valve oil outlet chamber 178, the first working oil port 2 and the second working oil port 3 are respectively communicated with the first working oil chamber 6 and the second working oil chamber 10, and the first oil return port 22 and the second oil return port 23 are respectively communicated with the first oil return chamber 9 and the second oil return chamber 103. These communication channels are common in the art and will not be described in detail here.

The direction change valve spool 4 is capable of being driven by a driver 140 (see fig. 1) to move in the direction change valve hole 5, and a plurality of recesses are provided on the direction change valve spool 4 to control the communication relationship among the main oil inlet chamber 1, the first working oil chamber 6, the second working oil chamber 10, the first oil return chamber 9, the second oil return chamber 103, the first load-sensitive feedback pressure take-off port 7, and the second load-sensitive feedback pressure take-off port 11 formed in the direction change valve hole 5.

The load-sensitive multi-way valve switching manifold 150 further includes a feedback oil passage formed in the valve body 100 for communicating one of the first load-sensitive feedback pressure tap 7 and the second load-sensitive feedback pressure tap 11 with the spring-side control chamber 172 according to the position of the switching spool 4 in the switching valve hole 5. The feedback oil circuit is completely formed in the valve body, an external pipeline and a connector are not needed, the structure of the reversing connection 150 is simplified, the volume of the reversing connection 150 is reduced, and the manufacturing cost of the reversing connection 150 is reduced.

Referring to fig. 3A, 6B to 6D, a shuttle valve 14 is provided in the feedback oil path, and the shuttle valve 14 feeds the larger pressure of the first load-sensitive feedback pressure tap 7 and the second load-sensitive feedback pressure tap 11 to the spring-side control chamber 172. The feedback circuit includes a first feedback hole 144 connecting the first load sensitive feedback pressure tap 7 to the shuttle valve 14, a second feedback hole 145 connecting the second load sensitive feedback pressure tap 11 to the shuttle valve 14, and a third feedback hole 146 connecting the shuttle valve 14 to the spring side control chamber 172. Wherein the second feedback aperture 145 comprises two sections of apertures perpendicular to each other to communicate the second load-sensitive tap 11 to the shuttle valve 14. Referring to fig. 6D, a plane in which the compensator spool 171 and the diverter spool 4 lie is defined as a reference plane, a plane in which the first and second feedback holes 144, 145 lie is perpendicular to the reference plane, and the third feedback hole 146 extends substantially parallel to the main reference plane.

Referring to fig. 6D and 6F, the shuttle valve 14 includes: a shuttle valve cavity 148, a sleeve 141, and a valve element 15 formed in the valve body 100. The shuttle chamber 148 is connected to the first feedback bore 144 and extends in the direction of the first feedback bore 144.

The sleeve 141 is fixedly disposed within the shuttle valve cavity 148 and is hollow. One end of the sleeve 141 facing the first feedback hole 144 is provided with an inner stepped portion 147, the other end 142 of the sleeve is located at the side of the reversing joint, and a radial opening 143 communicating with the second feedback hole 145 is provided on the sidewall of the sleeve 141, wherein the third feedback hole 146 communicates with the shuttle chamber 148 between the first feedback hole 144 and the radial opening 143 and is not blocked by the sleeve 141. Specifically, a reduced diameter portion is provided on the sleeve 141 at a position corresponding to the third feedback hole 146 so that the third feedback hole 146 communicates to the shuttle chamber 148.

The valve element 15 is located between the first feedback hole 144 and the inner step 147 of the sleeve 141 and is movable under the effect of the higher pressure in the first feedback hole 144 and the second feedback hole 145 to close the first feedback hole 144 or the inner step 147 to communicate the second feedback hole 145 or the first feedback hole 144 and the third feedback hole 146, respectively. Thus, when the pressure from the first feedback hole 144 is higher than the pressure from the second feedback hole 145, only the first feedback hole 144 is communicated to the third feedback hole 146; when the pressure from the second feedback hole 145 is higher than the pressure from the first feedback hole 144, only the second feedback hole 145 is communicated to the third feedback hole 146.

The operation principle according to the direction valve will be described with reference to fig. 3A to 5C.

Referring to fig. 3A to 3C, when the direction change valve spool 4 is in the neutral position, the first load-sensitive feedback pressure tapping 7 communicates with the first oil return chamber 9 through the first annular pressure tapping groove 8 and a first throttle groove 41 (see fig. 3C, 7) on the direction change valve spool 4, and the second load-sensitive feedback pressure tapping 11 communicates with the second oil return chamber 103 through a second annular pressure tapping groove 12 and a second throttle groove 42 (see fig. 3C, 7) on the direction change valve spool 4. The first working oil chamber 6 and the second working oil chamber 10 are both disconnected from the main oil inlet chamber 1. In the illustrated embodiment, both the first working-oil chamber 6 and the second working-oil chamber 10 are disconnected from the oil return chamber 9, 103 in the intermediate position, but the working- oil chambers 6, 10 may be provided in communication with the oil return chamber 9, 103, and these embodiments are within the scope of the present application.

Referring to fig. 4A to 4C, when the direction valve is in the first working position, the direction valve core 4 moves to the first side, the main oil inlet chamber 1 communicates with the first working oil chamber 6 through the third throttling groove 46, and the flow rate is regulated by the third throttling groove 46 (see fig. 7), and the main oil inlet chamber 1 communicates with the first load-sensitive feedback pressure-taking port 7 through the groove 48 on the direction valve core. The second working oil chamber 10 and the second load-sensitive feedback pressure tapping 11 are communicated with the second oil return chamber 103 through the throttling groove 42 and a communicating part on a valve core connected with the throttling groove.

Referring to fig. 5A to 5C, when the direction valve is in the second working position, the direction valve core 4 moves to a second side opposite to the first side, the main oil inlet chamber 1 communicates with the second working oil chamber 10 through a fourth throttling groove 47, the flow rate is regulated by the fourth throttling groove 47 (see fig. 7), and the main oil inlet chamber 1 communicates with the second load-sensitive feedback pressure tapping 11 through a groove 49 on the direction valve core. The first working oil chamber 6 and the first load-sensitive feedback pressure tapping 7 are communicated with the first oil return chamber 9 through the communication part on the throttle groove 41 and the valve core connected thereto.

Therefore, when the reversing valve core is in the middle position, the first load-sensitive feedback pressure tapping 7 and the second load-sensitive feedback pressure tapping 11 are both depressurized, and when the reversing valve core is in the first working position, the first load-sensitive feedback pressure tapping 7 transmits the pressure from the first working oil chamber 6 (which is greater than the pressure of the oil return chamber from the second load-sensitive feedback pressure tapping 11) to the shuttle valve 14, and further to the spring-side control chamber 172 of the compensation valve. When the diverter spool is in the second operating position, the second load-sensitive feedback pressure tap 11 transfers pressure from the second working oil chamber 10 (which is greater than the return oil chamber pressure from the first load-sensitive feedback pressure tap 7) to the shuttle valve 14 and, in turn, to the spring-side control chamber 172 of the compensator valve. According to the embodiment of the invention, independent pressure relief of the two working oil cavities is realized in a compact space, and unloading of the load sensitive oil pressure at the middle position can be realized.

As shown in fig. 3A to 3C, the load-sensitive multi-way valve reversing link 150 further includes: two direction valve springs 51 respectively disposed in direction valve spring cavities 52 of the direction valve hole 5 at both ends of the direction valve spool 4, and two spring seats 53 respectively disposed between the direction valve spool 4 and the two direction valve springs 51, the direction valve springs 51 applying a thrust to the direction valve spool 4 through the spring seats 53, and when the direction valve spool 4 is located at a middle position, both the spring seats 53 abut against axial stoppers 54 disposed in the direction valve hole 5. This allows the direction change valve body 4 to be accurately held at the intermediate position.

And connecting channels which respectively communicate the first oil return cavity 9 and the second oil return cavity 103 to the corresponding reversing valve spring cavity 52 are arranged between the two ends of the reversing valve core 4 and the spring seat 53, so that the reversing valve spring cavity 52 is decompressed to the oil return cavities. The connecting passage includes an oil passage 45 provided at the end surface of the direction change valve spool 4 or an oil passage 43 provided inside the direction change valve spool 4 (a surface oil passage 45 is shown in fig. 3A, 4A, 5A, and an internal oil passage 43 is shown in fig. 3B, 4B, 5B, it being understood by those skilled in the art that either or both of the oil passages 43, 45 may be employed), and a gap 530 provided between the end of the direction change valve spool 4 and the spring seat 53, as shown in fig. 3D.

As shown in fig. 3D, the spring seat 53 includes: a first section 531 extending axially and able to rest against the stop 54; a second section 532 extending radially inward from the first section 531 for abutting against an end of the diverter spool 4; and a third section 533 located radially inward of the second section 532 and extending radially, the third section 533 being spaced apart from the end of the direction valve spool 4 when the second section 532 abuts the end of the direction valve spool 4, forming a portion of the gap 530; and a fourth section 534 extending axially from the third section 533, wherein the direction valve spring 51 is sleeved outside the fourth section 534 and abuts against the third section 533.

As shown in fig. 3D, the direction valve core 4 includes a central protrusion 44 axially protruding from both ends, and the central protrusion 44 may be formed integrally with the direction valve core 4 or separately. When the second section 532 abuts the end of the diverter spool 4, the central protrusion 44 is received in the fourth section 534 and is spaced from the fourth section 534 forming part of the gap 530.

Referring to fig. 3A and 7, when the connection passage includes the surface oil passage 45 axially extending at the end surface of the direction changing valve spool 4, the load sensitive multi-way valve direction changing coupling 150 further includes a plunger 18 fixed within the valve body 100, and the end of the plunger 18 protrudes into the surface oil passage 45, thereby preventing the direction changing valve spool 4 from rotating while allowing the direction changing valve spool 4 to axially move. By preventing the reversing valve core 4 from rotating, a pressure tapping hole can be used for replacing a circumferential load sensitive feedback cavity on the reversing valve core 4; grooves/holes which are overlapped in the axial direction (staggered in the circumferential direction) and are not communicated with each other can be arranged on the reversing valve core 4 and the reversing valve hole 5, the axial sizes of the reversing valve core 4 and the whole valve body are shortened, and meanwhile, the design of the valve body and the valve core can be simpler.

The surface oil passage 45 may also be used only as a holding groove that receives the end of the jack 18, with no hydraulic oil flowing through the surface oil passage 45.

Referring to fig. 3A, a first annular pressure tap groove 8 communicating with a first load sensitive feedback pressure tap 7 and a second annular pressure tap groove 12 communicating with a second load sensitive feedback pressure tap 11 are provided in the reversing valve bore 5. The annular pressure-taking grooves 8, 12 not only contribute to achieving a balance of forces in the circumferential direction of the direction change valve spool 4 to reduce friction between the direction change valve spool 4 and the wall of the direction change valve hole 5, but also contribute to providing a load pressure relief valve in the oil passage on the side of the direction change valve spool 4 opposite to the pressure-taking ports 7, 11, and also contribute to communication between the pressure-taking ports 7, 11 and the oil return chambers 9, 103 when the direction change valve spool 4 is at the intermediate position, as described below. It will be appreciated that, unlike the embodiments described above, instead of providing an annular pressure tapping groove in the selector valve bore 5, the feedback pressure may be introduced into the pressure tapping ports 7, 11 via a flow passage inside the selector valve spool 4. Since the diverter valve spool 4 does not rotate, alignment between the internal flow passages of the diverter valve spool 4 and the pressure ports 7, 11 is achieved without the need for an annular groove in the diverter valve bore 5.

For the sake of simplicity, only the third and fourth balancing grooves 111, 112 are shown, the arrangement of the first and second balancing grooves being similar.

A first balance groove (not shown in the drawings) is provided locally in the inner wall of the reversing valve bore 5 adjacent the first annular pressure taking groove 8, the sum of the axial dimensions of the first annular pressure taking groove 8 and the first balance groove is greater than the axial dimension of the first load sensitive feedback pressure taking port 7, and a symmetrical second balance groove is provided in the inner wall of the reversing valve bore 5 at a position diametrically opposite the first balance groove.

The first and second balance grooves are both arranged crescent-shaped when viewed in the axial direction of the direction change valve spool 4, and the depth of the first and second balance grooves is smaller than the depth of the first annular pressure-taking groove 8.

Similarly, as shown in fig. 6A to 6D, a third balance groove 111 is provided locally in the inner wall of the reversing valve bore 5 at a position adjacent to the second annular pressure taking groove 12, the sum of the axial dimensions of the second annular pressure taking groove 12 and the third balance groove 111 is larger than the axial dimension of the second load-sensitive feedback pressure taking port 11, and a symmetrical fourth balance groove 112 is provided in the inner wall of the reversing valve bore 5 at a position diametrically opposite to the third balance groove 111 (see fig. 6C).

Both the third balance groove 111 and the fourth balance groove 112 are arranged crescent-shaped when viewed in the axial direction of the direction spool 4, and the depth of the third balance groove 111 and the fourth balance groove 112 is smaller than that of the second annular pressure taking groove 12, see fig. 6E.

The first to fourth balance grooves help achieve a balance of forces in the circumferential direction of the direction valve spool 4 to reduce friction between the direction valve spool 4 and the wall of the direction valve hole 5.

It will be appreciated by those skilled in the art that the embodiments described above are exemplary and can be modified by those skilled in the art, and that the structures described in the various embodiments can be freely combined without conflict in structure or principle.

Having described preferred embodiments of the present invention in detail, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope and spirit of the appended claims, and the invention is not to be limited to the exemplary embodiments set forth herein.

Claims (20)

1. A load-sensitive multi-way valve reversing unit comprises a valve body, a compensation valve and a reversing valve are formed in the valve body,

the compensation valve comprises a compensation valve hole formed in the valve body and a compensation valve core arranged in the compensation valve hole, wherein an oil inlet cavity of the compensation valve, an oil outlet cavity of the compensation valve, a spring side control cavity and a non-spring side control cavity are formed in the compensation valve hole,

the reversing valve comprises a reversing valve hole formed in the valve body and a reversing valve core arranged in the reversing valve hole, the reversing valve core controls the communication relation among a main oil inlet cavity, a first working oil cavity, a second working oil cavity, a first oil return cavity, a second oil return cavity, a first load sensitive feedback pressure tapping and a second load sensitive feedback pressure tapping formed in the reversing valve hole, and the compensation valve oil outlet cavity is communicated with the main oil inlet cavity;

the load-sensitive multi-way valve reversing linkage also comprises a feedback oil path formed in the valve body, and the feedback oil path is used for communicating one of the first load-sensitive feedback pressure tapping and the second load-sensitive feedback pressure tapping with the spring-side control cavity according to the position of the reversing valve core in the reversing valve hole.

2. The load-sensitive multi-way valve reversing linkage according to claim 1, wherein an oil inlet, a first working oil port, a second working oil port, a first oil return port and a second oil return port leading to the outside of the valve body are arranged on the valve body, wherein the oil inlet is communicated with the oil inlet cavity of the compensation valve, the first working oil port and the second working oil port are respectively communicated with the first working oil cavity and the second working oil cavity, and the first oil return port and the second oil return port are respectively communicated with the first oil return cavity and the second oil return cavity.

3. The load sensitive multiplex valve reversing linkage according to claim 1, a first oil return cavity, a first load sensitive feedback pressure tap, a first working oil cavity, a main oil inlet cavity, a second working oil cavity, a second load sensitive feedback pressure tap, and a second oil return cavity being arranged in sequence axially in the reversing valve bore.

4. The load-sensitive multi-way valve reversing linkage according to claim 1, wherein when the reversing valve core is in a middle position, the main oil inlet chamber is disconnected from both the first working oil chamber and the second working oil chamber, the first load-sensitive feedback pressure tapping port is communicated with the first oil return chamber, and the second load-sensitive feedback pressure tapping port is communicated with the second oil return chamber;

when the reversing valve is in a first working position, the reversing valve core moves to a first side, the main oil inlet cavity is communicated with the first working oil cavity and the first load sensitive feedback pressure taking port, and the second working oil cavity and the second load sensitive feedback pressure taking port are communicated with the second oil return cavity;

when the reversing valve is located at a second working position, the reversing valve core moves towards a second side, the main oil inlet cavity is communicated with the second working oil cavity and the second load-sensitive feedback pressure taking port, and the first working oil cavity and the first load-sensitive feedback pressure taking port are communicated with the first oil return cavity.

5. The load sensitive multiplex valve reversing link of claim 1, further comprising a shuttle valve disposed in the feedback oil path, the shuttle valve feeding a greater pressure of the first and second load sensitive feedback pressure taps to the spring side control chamber.

6. The load sensitive multiplex valve shuttle coupling of claim 5, said feedback oil circuit comprising a first feedback bore connecting a first load sensitive feedback pressure tap to a shuttle valve, a second feedback bore connecting a second load sensitive feedback pressure tap to a shuttle valve, and a third feedback bore connecting a shuttle valve to said spring side control chamber,

and defining the plane where the compensation valve core and the reversing valve core are positioned as a reference plane, wherein the plane where the first feedback hole and the second feedback hole are positioned is vertical to the reference plane, and the third feedback hole extends approximately parallel to the main reference plane.

7. The load sensitive multiplex valve reversing link of claim 6, said shuttle valve comprising: a shuttle valve cavity formed in the valve body, the shuttle valve cavity being connected to the first feedback hole and extending in a direction of the first feedback hole;

the sleeve is fixedly arranged in the shuttle valve cavity, an inner step portion is arranged on one side, facing the first feedback hole, of the sleeve, a radial opening communicated with the second feedback hole is arranged on the side wall of the sleeve, and a third feedback hole is communicated to the shuttle valve cavity between the first feedback hole and the radial opening and is not blocked by the sleeve;

a valve element located between the first feedback hole and the internal step of the sleeve and movable under the action of the higher pressure in the first and second feedback holes to close the first or internal step to communicate the second or first and third feedback holes, respectively.

8. The load sensitive multiplex valve reversing link of claim 1, having a first annular pressure tap groove in communication with the first load sensitive feedback pressure tap and a second annular pressure tap groove in communication with the second load sensitive feedback pressure tap disposed in the reversing valve bore.

9. The load-sensitive multi-way valve reversing linkage according to claim 8, wherein when the reversing valve spool is in the intermediate position, the first load-sensitive feedback pressure tapping port is communicated with the first oil return cavity through the first annular pressure tapping groove and a first throttling groove in the reversing valve spool, and the second load-sensitive feedback pressure tapping port is communicated with the second oil return cavity through the second annular pressure tapping groove and a second throttling groove in the reversing valve spool.

10. The load sensitive multiplex valve shift link of claim 8, having a first balance groove provided locally in the inner wall of the shift valve bore adjacent the first annular pressure tap groove, the sum of the axial dimensions of the first annular pressure tap groove and the first balance groove being greater than the axial dimension of the first load sensitive feedback pressure tap,

a symmetrical second balance groove is provided in the inner wall of the reversing valve bore at a location diametrically opposite the first balance groove.

11. The load sensitive multiplex valve trip link of claim 10,

when viewed along the axial direction of the reversing valve core, the first balance groove and the second balance groove are both arranged in a crescent shape, and the depth of the first balance groove and the second balance groove is smaller than that of the first annular pressure taking groove.

12. The load sensitive multiplex valve shift link of claim 8, having a third balance groove provided locally in the inner wall of the shift valve bore adjacent the second annular take-up groove, the sum of the axial dimensions of the second annular take-up groove and the third balance groove being greater than the axial dimension of the second load sensitive feedback take-up port,

and a symmetrical fourth balance groove is arranged at the position, opposite to the third balance groove in the radial direction, in the inner wall of the reversing valve hole.

13. The load sensitive multiplex valve trip link of claim 12,

when viewed in the axial direction of the direction valve spool, the third balance groove and the fourth balance groove are both arranged in a crescent shape, and the depth of the third balance groove and the fourth balance groove is smaller than that of the second annular pressure taking groove.

14. The load sensitive multiplex valve reversing coupling of claim 1, further comprising:

two change valve springs respectively provided in change valve spring cavities of the change valve hole at both ends of the change valve spool, an

And the two spring seats are respectively positioned between the reversing valve core and the two reversing valve springs, the reversing valve springs apply thrust to the reversing valve core through the spring seats, and when the reversing valve core is positioned at the middle position, the two spring seats are abutted against an axial stop part arranged in the reversing valve hole.

15. The load sensitive multiplex valve linkage of claim 14, having connection passages between both ends of the reversing valve spool and the spring seat that fluidly connect the first and second oil return chambers, respectively, to the corresponding reversing valve spring cavities, said connection passages including oil passages provided on or within the end surface of the reversing valve spool and gaps provided between the end of the reversing valve spool and the spring seat.

16. The load sensitive multiplex valve trip link of claim 15, wherein the spring seat comprises:

a first section extending axially and capable of abutting against a stop;

a second section extending radially inward from the first section for abutting against an end of the diverter spool; and

a third section radially inward of the second section and extending radially, the third section being spaced from the end of the diverter spool when the second section abuts the end of the diverter spool, forming a portion of the gap;

and a fourth section extending axially from the third section, the reversing valve spring being sleeved outside the fourth section and abutting against the third section.

17. The load sensitive multiplex valve linkage of claim 16, the diverter spool including a central projection extending axially from both ends, the central projection being received in and spaced from the fourth segment forming a portion of the gap when the second segment abuts the end of the diverter spool.

18. The load sensitive multiplex valve linkage of claim 14, having connection passages between each end of the reversing valve spool and the spring seat for fluidly connecting the first and second oil return chambers to the corresponding reversing valve spring cavity, said connection passages including surface oil channels extending axially in the end surface of the reversing valve spool, said load sensitive multiplex valve linkage further comprising a plunger fixed in the valve body, the end of said plunger extending into said surface oil channels, thereby allowing axial movement of said reversing valve spool while preventing rotation of said reversing valve spool.

19. The load sensitive multiplex valve linkage of claim 1, said valve body further having a pushrod disposed therein, an end of said pushrod being received in an axially extending retention groove in an end of a diverter spool to permit axial movement of said diverter spool while preventing rotation of said diverter spool.

20. The load sensitive multiplex valve linkage of claim 1, a spring-less side control chamber of said compensator valve communicates to said compensator valve oil outlet chamber through a channel located inside said compensator valve spool, said compensator valve spool moves in response to a pressure differential between said spring-side control chamber and said spring-less side control chamber.

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