Load-sensitive combination valve

Abstract

The utility model relates to the technical field of tractor hydraulic valve groups, in particular to a load-sensitive combination valve. Comprising a valve body, an oil inlet P, an oil return port T, a working oil port A and a working oil port B are formed in the valve body, and the working oil port B and the oil return port T are communicated through a switching valve cavity. And the first bypass cavity is provided with a single-action and double-action switch used for controlling the first bypass cavity to be opened and closed. When the single-action and double-action switch is closed, the combination valve in the device can be connected with a double-interface executing mechanism, and when the single-action and double-action switch is opened, the combination valve in the device can be connected with a single-interface executing mechanism, so that the applicability of the device is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to tractor hydraulic valve group technical field, concretely relates to a load sensitive combination valve. BACKGROUND

[0002] The load sensitive combination valve is a kind of key element for dynamically adjusting the output pressure and flow of pump according to load demand in hydraulic system, and its core function is to automatically select the highest pressure in multiple loads by shuttle valve, then the highest load pressure signal is transmitted to pump through LS oil way, and the displacement controller of pump adjusts output flow according to valve core opening amount, to ensure that flow is distributed on demand, so as to dynamically adjust system pressure and flow according to the load demand of actuator, thereby optimizing energy utilization efficiency and improving operation accuracy.

[0003] In prior art, load sensitive combination valve inlet and outlet oil connection, working connection and tail connection, wherein, the most important working connection includes the driving mechanism of valve rod, valve rod, oil cavity, P inlet, T return port and working oil port etc., the current mainstream actuator is mainly divided into double-acting actuator and single-acting actuator, the combination valve applied on double-acting actuator is provided with A working oil port and B working oil port, and the combination valve applied on single-acting actuator is only provided with A working oil port, the load sensitive combination valves applied on the two are not universal, and the applicability is poor, thus a load sensitive combination valve capable of being used on double-acting actuator and single-acting actuator is needed. CONTENT OF UTILITY MODEL

[0004] In view of the above problems, the utility model provides a load sensitive combination valve to solve the problems of non-universal load sensitive combination valve and poor applicability in prior art.

[0005] The utility model is used following technical scheme to realize: a load sensitive combination valve, including tail connection and inlet and outlet oil connection arranged in front and back and several working connections fixedly installed between the two, the working connection includes valve body, the valve body is equipped with transversely arranged switching valve cavity, the switching valve cavity is slidably installed with valve rod that can be driven to move left and right by driving mechanism, the valve body is equipped with P inlet below the valve rod, the valve body is further equipped with A working oil port, B working oil port and T return port above the valve rod, P inlet is communicated with switching valve cavity through first inlet cavity, one side of first inlet cavity is equipped with second inlet cavity, both ends of second inlet cavity are communicated with switching valve cavity, B working oil port is communicated with switching valve cavity through first working cavity, T return port is communicated with switching valve cavity through return cavity, A working oil port is communicated with switching valve cavity through second working cavity, hydraulic lock for controlling the on-off of second working cavity is equipped on second working cavity, first bypass cavity communicated with T return port is equipped on first working cavity, single-acting and double-acting switch capable of controlling the on-off of first bypass cavity and T return port is equipped on first bypass cavity;

[0006] When the valve rod is in the second state, the P oil inlet communicates with the B working oil port through the first oil inlet chamber, the second oil inlet chamber and the first working chamber, and the A working oil port communicates with the T return oil port through the second working chamber and the return oil chamber; when the single-double acting switch is in the closed state and the valve rod is in the third state, the P oil inlet communicates with the A working oil port through the first oil inlet chamber and the second working chamber, and the B working oil port communicates with the T return oil port through the first working chamber and the return oil chamber; when the valve rod is in the first state, the P oil inlet does not communicate with the first working chamber and the second working chamber.

[0007] Through the above structure, when the single-double acting switch is in the closed state, the device can be applied to the double-interface actuator, and when the single-double acting switch is in the open state, the device can be connected with the single-interface actuator for use, thereby making the use range of the device wider and increasing the applicability of the device.

[0008] Preferably, the single-double acting switch comprises a switch chamber arranged at the top of the valve body, the right end of the first bypass chamber communicates with the middle part of the switch chamber, the bottom end of the switch chamber communicates with the T return oil port, and a mounting seat is fixedly installed at the top of the switch chamber, a mounting column capable of moving up and down is sleeved on the inner side of the mounting seat, and a plug for plugging the switch chamber is fixedly installed at the bottom of the mounting column; when the single-double acting switch is in the closed state, the plug is located in the switch chamber below the first bypass chamber and plugs it, and when the single-double acting switch is in the open state, the plug is located in the upper part of the connection between the first bypass chamber and the switch chamber, and the first bypass chamber communicates with the T return oil port through the switch chamber. The up and down movement of the mounting column and the plug controls the communication between the first bypass chamber and the switch chamber, so that the structure of the device is simple and the operation is convenient.

[0009] Preferably, a first sealing ring is arranged between the mounting seat and the valve body, a second sealing ring is arranged between the mounting column and the mounting seat, and a third sealing ring is arranged between the plug and the switch chamber. The arrangement of multiple sealing rings prevents oil leakage.

[0010] Preferably, the hydraulic lock comprises an upper lock chamber and a lower lock chamber arranged at the top of the valve body, the bottom of the upper lock chamber communicates with the left end of the second working chamber, the top of the lower lock chamber communicates with the left end of the second working chamber, a first valve core capable of sliding up and down and plugging the lower lock chamber is installed in the upper lock chamber, a second valve core capable of upwardly fixing the first valve core is slidingly installed below the first valve core of the valve body, and a reset mechanism for downwardly abutting against the first valve core is further installed above the first valve core of the upper lock chamber. The arrangement of the hydraulic lock enables the oil to flow in one direction only, making the device more stable.

[0011] Preferably, the reset mechanism comprises a top seat located at the top of the upper locking cavity and fixedly connected with the valve body, the bottom end of the top seat is fixedly connected with a first spring, and the lower end of the first spring is fixedly connected with the first valve core.

[0012] Preferably, the top of the first valve core is provided with a clamping groove, the bottom surface of the clamping groove is fixedly installed with a baffle, the bottom end of the first spring is fixedly connected with the baffle, the middle part of the first valve core is provided with a mounting hole in communication with the clamping groove, the bottom part of the first valve core is provided with a top hole in communication with the mounting hole, a second spring is installed in the mounting hole, the top end of the second spring is fixedly connected with the baffle, the bottom end of the second spring is fixedly connected with a steel ball, when the steel ball is located at the lowermost part of the mounting hole, the steel ball can completely block the top hole, and the top of the second valve core is provided with an upward protrusion, when the second valve core moves upward, the protrusion can lift the steel ball.

[0013] Preferably, the switching valve cavity is sequentially provided, from left to right, with a first cavity in communication with one end of the second oil inlet cavity, a second cavity in communication with the first working cavity, a third cavity in communication with the oil return cavity, a fourth cavity in communication with the lower locking cavity, a fifth cavity in communication with the other end of the second oil inlet cavity, and a sixth cavity in communication with the first working cavity; the valve rod is provided with a first groove capable of controlling the on-off of the first cavity and the second cavity and the second cavity and the third cavity, a second groove controlling the on-off of the third cavity and the fourth cavity, the fourth cavity and the fifth cavity, a third groove controlling the on-off of the fifth cavity and the sixth cavity, and a fourth groove. Through the arrangement of the grooves on the valve rod and the cavities on the switching valve cavity, the left and right movement of the valve rod can switch the communication of different cavities.

[0014] Preferably, the bottom of the second valve core is in contact with the second groove, the bottom of the second valve core is hemispherical, and the right side wall of the second groove is inclined, when the valve rod is in the first state, the bottom of the second valve core is located at the bottom of the slope. Through the arrangement of the second valve core and the second groove, when the valve body is switched from the first state to the second state, the second valve core will move upward to lift the first valve core, thereby playing the role of opening the hydraulic lock.

[0015] Preferably, an overflow valve is further installed at the position of the valve body above the valve rod, the second working cavity is communicated with a second bypass cavity, the second bypass cavity is communicated with an overflow port through the overflow valve, and the first oil inlet cavity is provided with a pressure compensation valve for controlling the opening and closing thereof. Through the arrangement of the overflow valve and the pressure compensation valve, the pressure can be automatically adjusted to prevent the pressure from being too high, so that the device can be more stable.

[0016] Preferably, the driving mechanism comprises a shell fixedly installed on one side of the valve body, a motor fixedly installed at the bottom of the shell, a lead screw connected with the output end of the motor through gear transmission, a threaded sleeve threadedly matched with the lead screw, and a valve rod fixedly connected with the threaded sleeve away from the lead screw.

[0017] In summary, the utility model has the advantages that:

[0018] 1. The first bypass cavity is arranged, so that the first working cavity has a branch capable of flowing to the T return oil port, when the B working oil port is not connected with the actuator, the oil in the first oil inlet cavity and the second oil inlet cavity can return to the T return oil port through the first working cavity and the first bypass cavity, thereby the pressure of the two oil inlet cavities is zero, so that the pressure regulating valve is closed, and the normal work of the valve body is not affected, and when the B working oil port and the A working oil port are connected with the actuator, only the single-acting and double-acting switch needs to be closed to be normally used, so that the device can be applied to single-interface actuators and double-interface actuators, and the applicability of the device is increased.

[0019] 2. The hydraulic lock is arranged in the device, so that the valve sleeve is not needed, the structure of the device is simple, and the flow capacity of the hydraulic lock in the device is larger on the basis of occupying the same space. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 It is a schematic diagram of the structure of the working link;

[0022] Figure 3 It is a sectional view of the working link when the single-acting and double-acting switch is closed and the working link valve rod is in the first state;

[0023] Figure 4 It is a sectional view of the working link when the single-acting and double-acting switch is closed and the working link valve rod is in the second state;

[0024] Figure 5 It is a sectional view of the working link when the single-acting and double-acting switch is closed and the working link valve rod is in the third state;

[0025] Figure 6 It is a sectional view of the working link when the single-acting and double-acting switch is opened and the working link valve rod is in the second state;

[0026] Figure 7 It is Figure 3 It is a local enlarged view of the "A" area in the middle;

[0027] Figure 8 For Figure 3 Local enlarged view of area "B" in FIG.

[0028] Figure 9 For Figure 3 Local enlarged view of area "C" in FIG.

[0029] In the figure: 1 - working link; 2 - oil inlet and return link; 3 - tail link;

[0030] 100 - driving mechanism; 101 - motor; 102 - driving gear; 103 - transition gear; 104 - driven gear; 105 - screw rod; 106 - threaded sleeve; 107 - magnet; 108 - position sensor; 109 - machine shell;

[0031] 110 - valve body; 111 - valve rod; 112 - limit cover; 113 - switching valve cavity; 114 - T-shaped oil return port; 115 - oil return cavity;

[0032] 120 - B working oil port; 121 - first working cavity; 122 - first bypass cavity;

[0033] 130 - single / double action switch; 131 - mounting seat; 132 - mounting column; 133 - first sealing ring; 134 - second sealing ring; 135 - third sealing ring; 136 - plug; 137 - switch cavity;

[0034] 140 - hydraulic lock; 141 - top seat; 142 - first spring; 143 - baffle; 144 - first valve core; 145 - second spring; 146 - steel ball; 147 - second valve core; 148 - upper lock cavity; 149 - clamping groove; 1491 - mounting hole; 1492 - top hole; 1493 - lower lock cavity;

[0035] 150 - A working oil port; 151 - second working cavity; 152 - second bypass cavity; 153 - overflow valve; 154 - overflow port;

[0036] 160 - pressure compensation valve; 161 - compensation valve core; 162 - third spring; 163 - compensation valve cavity;

[0037] 170 - P oil inlet port; 171 - first oil inlet cavity; 172 - second oil inlet cavity;

[0038] 180 - LS oil way; 181 - shuttle valve;

[0039] 190 - first cavity; 191 - second cavity; 192 - third cavity; 193 - fourth cavity; 194 - fifth cavity; 195 - sixth cavity; 196 - first groove; 197 - second groove; 198 - third groove; 199 - fourth groove. DETAILED DESCRIPTION

[0040] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0041] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0042] The following is a description of the preferred embodiments of the present application in conjunction with the accompanying drawings.

[0043] As shown in Figure 1 , Figure 2 The present application provides a load-sensitive combined valve, which comprises tail connections 3 and oil inlet and return connections 2 arranged front and back, and a plurality of working connections 1 fixedly installed between the two, the working connection 1 is provided with a shuttle valve 181 and an LS oil way 180, when a plurality of actuators work at the same time, the pressure in the working connection 1 connected with the actuators is different, and the function of the shuttle valve 181 is to select the highest load pressure in the working connection 1, and then transmit this pressure signal to the pump through the LS oil way 180, and the pump adjusts the flow of the system, so as to realize accurate energy matching under complex working conditions. The adjustment by cooperation of the shuttle valve 181 and the LS oil way 180 belongs to the prior art, and can be easily understood by those skilled in the art through patents, videos and the like in the field, and will not be described in detail here.

[0044] As shown in Figures 2 to 5As shown, the working link 1 in the device includes a valve body 110, which is provided with a switching valve cavity 113 transversely penetrating through the valve body 110, and a valve rod 111 slidably installed in the switching valve cavity 113 and capable of being driven by the driving mechanism 100 to move left and right to switch states, the valve rod 111 mainly has first, second and third states. The valve body 110 is provided with a P oil inlet 170 below the valve rod 111, and is further provided with an A working oil port 150, a B working oil port 120 and a T oil return port 114 above the valve rod 111. The P oil inlet 170 is communicated with the switching valve cavity 113 through a first oil inlet cavity 171, the left side of the first oil inlet cavity 171 is provided with a second oil inlet cavity 172, both ends of the second oil inlet cavity 172 are communicated with the switching valve cavity 113, the B working oil port 120 is communicated with the switching valve cavity 113 through a first working cavity 121, the T oil return port 114 is communicated with the switching valve cavity 113 through an oil return cavity 115, and the A working oil port 150 is communicated with the switching valve cavity 113 through a second working cavity 151. A hydraulic lock 140 for controlling whether the A working oil port 150 is communicated with the switching valve cavity 113 or not is arranged on the second working cavity 151, a pressure compensation valve 160 for controlling whether the P oil inlet is communicated with the switching valve cavity 113 or not is arranged on the first oil inlet cavity 171, a first bypass cavity 122 communicated with the T oil return port 114 is arranged on the first working cavity 121, and a single-acting and double-acting switch 130 capable of controlling whether the first bypass cavity 121 is communicated with the T oil return port 114 or closed is arranged on the first bypass cavity 122.

[0045] As shown in Figure 3 , Figure 9 , the switching valve cavity 113 is sequentially provided with a first cavity 190 communicated with one end of the second oil inlet cavity 172, a second cavity 191 communicated with the first working cavity 121, a third cavity 192 communicated with the oil return cavity 115, a fourth cavity 193 communicated with the lower lock cavity 1493, a fifth cavity 194 communicated with the other end of the second oil inlet cavity 172, and a sixth cavity 195 communicated with the first working cavity 171. The valve rod 111 is sequentially provided with a first groove 196, a second groove 197, a third groove 198 and a fourth groove 199 from left to right. When the valve rod 111 is in the first state, the six cavities of the switching valve cavity 113 are not communicated; when the valve rod 111 is in the second state, the fifth cavity 194 and the sixth cavity 195 are communicated through the fourth groove 199, the first cavity 190 and the second cavity 191 are communicated through the first groove 196, and the third cavity 192 and the fourth cavity 193 are communicated through the second groove 197; when the valve rod 111 is in the third state, the fourth cavity 193 and the fifth cavity 194 are communicated through the second groove 197, the fifth cavity 194 and the sixth cavity 195 are communicated through the third groove 198, and the second cavity 191 and the third cavity 192 are communicated through the first groove 196.

[0046] As shown in Figure 4 , Figure 5For example, when the valve stem 111 is in the second state, the first groove 196 is located between the first cavity 190 and the second cavity 191, the second groove 197 is located between the third cavity 192 and the fourth cavity 193, and the fourth groove 199 is located between the fifth cavity 194 and the sixth cavity 195. When the valve stem 111 is in the third state, the first groove 196 is located between the second cavity 191 and the third cavity 192, the second groove 197 is located between the fourth cavity 193 and the fifth cavity 194, and the third groove 198 is located between the fifth cavity 194 and the sixth cavity 195.

[0047] As shown in Figure 3 , Figure 7 , the single / double-acting switch 130 includes a switch cavity 137 arranged at the top of the valve body 110, the right end of the first bypass cavity 122 is in communication with the middle part of the switch cavity 137, the bottom end of the switch cavity 137 is in communication with the T oil return port 114, and the top of the switch cavity 137 is fixedly installed with a mounting seat 131. The inner side of the mounting seat 131 is sleeved with a mounting column 132 capable of moving up and down, and the bottom of the mounting column 132 is fixedly installed with a plug 136 for plugging the switch cavity 137. When the single / double-acting switch 130 is in the closed state, the plug 136 is located in the switch cavity 137 below the first bypass cavity 122 and plugs it, and when the single / double-acting switch 130 is in the open state, the plug 136 is located in the upper part of the connection between the first bypass cavity 122 and the switch cavity 137, and the first bypass cavity 122 is in communication with the T oil return port 114 through the switch cavity 137.

[0048] The up and down movement of the mounting column 132 is mainly realized by threaded cooperation. Specifically, an internal thread is arranged on the inner side of the mounting seat 131, and an external thread is arranged on the outer side of the mounting column 132, and the two are installed by threaded cooperation. When the A working oil port 150 and the B working oil port 120 are both connected with the actuator, the single / double-acting switch 130 is in the closed state, and when only the A working oil port 150 is connected with the actuator, the B working oil port 120 is plugged by the sealing plug at this time. Twist the mounting column 132 so that the mounting column 132 moves upward, and at this time the single / double-acting switch 130 is opened.

[0049] In order to prevent oil from leaking out of the gap of the single / double-acting switch 130 and affecting its sealing and isolation effect, a first sealing ring 133 is installed between the mounting seat 131 and the valve body 110, a second sealing ring 134 is arranged between the mounting column 132 and the mounting seat 131, and a third sealing ring 135 is arranged between the plug 136 and the switch cavity 137.

[0050] As shown in Figure 3 , Figure 8As shown, the hydraulic lock 140 includes an upper lock cavity 148 and a lower lock cavity 1493 arranged at the top of the valve body 110, the bottom end of the upper lock cavity 148 communicates with the top end of the lower lock cavity 1493, the bottom of the upper lock cavity 148 communicates with the left end of the second working cavity 151, the top of the lower lock cavity 1493 communicates with the left end of the second working cavity 151, a first valve core 144 capable of sliding up and down and blocking the lower lock cavity 1493 is arranged in the upper lock cavity 148, a second valve core 147 capable of fixing the first valve core 144 upward is slidingly arranged below the first valve core 144, and a reset mechanism for pressing the first valve core 144 downward is arranged above the first valve core 144.

[0051] The reset mechanism described above can be any mechanism capable of blocking the first valve core 144 when there is no pressure, so that it blocks the lower lock cavity 1493, for example, by the arrangement of a damper. In the embodiment, the reset mechanism includes a top seat 141 arranged at the top of the upper lock cavity 148 and fixedly connected with the valve body, the bottom end of the top seat is fixedly connected with a first spring 142, and the lower end of a second spring 145 is fixedly connected with the first valve core 144.

[0052] The top of the first valve core 144 is provided with a clamping groove 149, the bottom of the clamping groove 149 is fixedly provided with a baffle 143, the bottom end of the first spring 142 is fixedly connected with the baffle 143, the middle of the first valve core 144 is provided with a mounting hole 1491 communicating with the clamping groove 149, the bottom of the first valve core 144 is provided with a top hole 1492 communicating with the mounting hole 1491, the mounting hole 1491 is arranged with the second spring 145, the top end of the second spring 145 is fixedly connected with the baffle 143, the bottom end of the second spring 145 is fixedly connected with a steel ball 146, when the steel ball 146 is located at the lowermost position of the mounting hole 1491, the steel ball 146 can completely block the top hole 1492, and the top of the second valve core 147 is provided with an upward protrusion, when the second valve core 147 moves upward, the protrusion can lift the steel ball 146.

[0053] The bottom of the second valve core 147 is located in the second groove 197 and always in contact with the second groove 197, the bottom of the second valve core 147 is hemispherical, and the right side wall of the second groove 197 is an inclined surface, when the valve rod 111 is in the first state, the bottom of the second valve core 147 is located at the bottommost position of the inclined surface.

[0054] When the valve stem 111 moves to the left, the second spool 147 moves upward, first lifts the steel ball 146, completes the flow of the pilot oil, balances the pressure, and as the valve stem 111 continues to move to the left, the second spool 147 will lift the first spool 144 upward, when the valve stem 111 is in the second state, the first spool 144 is lifted, and the second working chamber 151 is communicated with the lower locking chamber 1493. When the valve stem 111 moves to the right, the steel ball 146 is lifted by oil pressure, and then the first spool 144 is also lifted by oil pressure, so that the second working chamber 151 is communicated with the lower locking chamber 1493.

[0055] In the device, the hydraulic lock 140 adopts an internal hydraulic lock 140 structure, and the first spool 144 is directly placed in the upper locking chamber 148, so that the device has a simpler structure, and the flow capacity of the hydraulic lock 140 in the device is larger under the condition of occupying the same space.

[0056] As a further description of the present example, in order to prevent the pressure at the second working chamber 151 from being too large, an overflow valve 153 is also installed at the position of the valve body 110 above the valve stem 111, the second working chamber 151 is communicated with the second bypass chamber 152, and the second bypass chamber 152 is communicated with the overflow port 154 through the overflow valve 153. When the pressure in the second working chamber 151 is too large, the overflow valve 153 will be opened, and the oil will flow into the overflow port 154 through the second bypass chamber 152, and the overflow port 154 is communicated with the oil tank. The overflow valve 153 also belongs to the prior art and is a protection valve, which will not be described in detail here.

[0057] As shown in Figure 4 The pressure compensation valve 160 in the device mainly includes a compensation valve chamber 163 arranged on the valve body 110, a compensation spool 161 capable of moving left and right is arranged in the compensation valve chamber 163, a third spring 162 is fixedly arranged at the leftmost end of the compensation valve chamber 163, and the rightmost end of the third spring 162 is fixedly connected with the compensation spool 161. A P oil inlet 170 is communicated with the right part of the compensation valve chamber 163, the middle part of the second working chamber 151 is communicated with the left part of the compensation valve chamber 163, and the end of the first working chamber 121 away from the valve stem 111 is communicated with the middle part of the compensation valve chamber 163. The compensation spool 161 can block the compensation valve chamber 163 between the first working chamber 121 and the P oil inlet 170, and when the compensation spool 161 moves to the right, the flow of the P oil inlet 170 flowing into the first working chamber 121 can be adjusted, so as to realize the adjustment of the pressure; specifically, the automatic adjustment of the pressure compensation valve 160 is realized by comparing the pressure at the P oil inlet 170 with the pressure in the first working chamber 121 plus the pressure in the second working chamber 151 plus the elastic force of the third spring 162.

[0058] As shown in Figure 4As shown, the drive mechanism 100 includes a housing 109 fixedly installed on one side of the valve body 110, a motor 101 fixedly installed on the bottom of the housing 109, an output end of the motor 101 fixedly connected with a driving gear 102, the driving gear 102 drivingly connected with a driven gear 104 through a transition gear 103, the driven gear 104 coaxially fixedly connected with a lead screw 105, a threaded sleeve 106 threadedly fitted on the right part of the lead screw 105, and an end of the threaded sleeve 106 away from the lead screw 105 fixedly connected with a valve rod 111. A limit cover 112 is also fixedly installed on the side of the valve body 110 away from the drive mechanism 100, and the limit cover 112 covers the rightmost end of the valve rod 111. The limit cover 112 mainly limits the transverse movement of the valve rod 111, preventing it from moving too far to the right.

[0059] As a further illustration of the present example, a magnet 107 is also fixedly installed on the threaded sleeve 106, and a position sensor 108 is fixedly installed above the housing 109. The position of the magnet 107 is sensed by the position sensor 108, so as to calculate the position of the valve rod 111.

[0060] Taking the hydraulic cylinder as an example, when the A working oil port 150 is connected with the rodless cavity of the hydraulic cylinder, and the B working oil port 120 is connected with the cylinder cavity of the hydraulic cylinder, the working principle when the single / double acting switch 130 is in the closed state is as follows:

[0061] When the valve rod 111 is in the first state, the P oil inlet 170 does not introduce oil into the valve body 110, and the hydraulic cylinder is in a static state.

[0062] When the valve rod 111 is in the second state, the hydraulic lock 140 is opened under the action of the second spool 147, and the oil introduced by the P oil inlet 170 flows through the pressure regulating valve 160, the first oil inlet cavity 171, the fourth groove 199, the second oil inlet cavity 172, the first groove 196, the first working cavity 121, and finally flows to the rod cavity through the B working oil port 120. At this time, the A working oil port 150 also introduces oil into the valve body 110, and this part of oil flows through the second working cavity 151, the lower lock cavity 1493, the second groove 197, the oil return cavity 115, and finally flows back to the oil tank through the T oil return port 114. At this time, the piston rod of the hydraulic cylinder is withdrawn into the hydraulic cylinder.

[0063] When the valve rod 111 is in the third state, the oil flowing into the P inlet 170 flows through the pressure compensation valve 160, the first oil inlet cavity 171, the third groove 198, the second groove 197, the lower locking cavity 1493 in turn, and then lifts the first valve core 144, flows through the second working cavity 151, and then flows from the A working oil port 150 to the rodless cavity of the hydraulic cylinder; at the same time, the B working oil port 120 also introduces oil into the valve body 110, and the oil flows through the first working cavity 121, the first groove 196, the oil return cavity 115, and then flows back to the tank through the T oil return port 114, at this time, the piston rod of the hydraulic cylinder extends outward.

[0064] When the A working oil port 150 is connected with the rodless cavity of the hydraulic cylinder, the B working oil port 120 is blocked, and the single-double acting switch 130 is in the open state, the working principle is as follows:

[0065] When the valve rod 111 is in the first state, the P inlet 170 is not supplied with oil, at this time, the hydraulic cylinder is in a static state. When the valve rod 111 is in the third state, the oil flows from the P inlet 170 to the A working oil port 150, and the process is consistent with the above-mentioned double interface, and the oil in the first working cavity 121 also flows into the T oil return port 114, so that the first working cavity 121 is not under pressure, at this time, the piston rod of the hydraulic cylinder is in an extended state.

[0066] When the piston rod is pressed back by the mechanical gravity, at this time, the valve rod 111 is in the second state, the oil in the rodless cavity of the hydraulic cylinder flows through the A working oil port 150 to the T oil return port 114, and at this time, the first working cavity 121 is not supplied with oil, that is, there is no pressure, but the first oil inlet cavity 171 and the second oil inlet cavity 172 connected therewith are supplied with oil, at this time, the oil flows into the T oil return port 114 along the first working cavity 121 and the first bypass cavity 122, so that the pressure in the first oil inlet cavity 171 and the second oil inlet cavity 172 decreases or even disappears, at this time, the pressure at the P inlet 170 is greater than the elastic force of the third spring 162 plus the pressure in the first oil inlet cavity 171 and the second oil inlet cavity 172, the compensation valve core 161 moves to the left, so that the first oil inlet cavity 171 is no longer connected with the P inlet 170, and oil is no longer supplied to the valve body 110, thereby realizing the retraction of the piston rod.

[0067] The preferred embodiments of the present application are described above, and it should be pointed out that for ordinary technical personnel in the technical field, some improvements and replacements can be made without departing from the technical principles of the present application, and these improvements and replacements should also be regarded as the protection scope of the present application.

Claims

1. A load sensitive combination valve comprising a tail joint (3) and an inlet and return joint (2) arranged in front and back, and a plurality of working joints (1) fixedly installed between the two, characterized in that, The working joint (1) comprises a valve body (110), a switching valve cavity (113) is arranged transversely in the valve body (110), a valve rod (111) capable of being driven to move left and right by a driving mechanism (100) is slidably arranged in the switching valve cavity (113), the valve body (110) is provided with a P oil inlet (170) below the valve rod (111), and the valve body (110) is further provided with an A working oil port (150), a B working oil port (120) and a T oil return port (114) above the valve rod (111); the P oil inlet (170) is communicated with the switching valve cavity (113) through a first oil inlet cavity (171), one side of the first oil inlet cavity (171) is provided with a second oil inlet cavity (172), both ends of the second oil inlet cavity (172) are communicated with the switching valve cavity (113), the B working oil port (120) is communicated with the switching valve cavity (113) through a first working cavity (121), the T oil return port (114) is communicated with the switching valve cavity (113) through an oil return cavity (115), and the A working oil port (150) is communicated with the switching valve cavity (113) through a second working cavity (151); a hydraulic lock (140) for controlling the opening and closing of the second working cavity (151) is arranged on the second working cavity (151), a first bypass cavity (122) communicated with the T oil return port (114) is arranged on the first working cavity (121), and a single-acting and double-acting switch (130) capable of controlling the opening and closing of the first bypass cavity (122) and the T oil return port (114) is arranged on the first bypass cavity (122); When the valve rod (111) is in the second state, the P oil inlet (170) is communicated with the first working cavity (121) and the B working oil port (120) through the first oil inlet cavity (171) and the second oil inlet cavity (172); when the single-acting and double-acting switch (130) is in the closed state and the valve rod (111) is in the third state, the P oil inlet (170) is communicated with the A working oil port (150) through the first oil inlet cavity (171) and the second working cavity (151), and the B working oil port (120) is communicated with the T oil return port (114) through the first working cavity (121) and the oil return cavity (115); when the valve rod (111) is in the first state, the P oil inlet (170) is not communicated with the first working cavity (121) and the second working cavity (151).

2. The load sensing combination valve of claim 1, wherein, The single / double-acting switch (130) comprises a switch cavity (137) arranged at the top of the valve body (110), the right end of the first bypass cavity (122) is communicated with the middle part of the switch cavity (137), the bottom end of the switch cavity (137) is communicated with the T oil return port (114), the top of the switch cavity (137) is fixedly installed with a mounting seat (131), the inner side of the mounting seat (131) is sleeved with a mounting column (132) capable of moving up and down, the bottom of the mounting column (132) is fixedly installed with a plug (136) for plugging the switch cavity (137); when the single / double-acting switch (130) is in the closed state, the plug (136) is located below the first bypass cavity (122) in the switch cavity (137) and plugs it, when the single / double-acting switch (130) is in the open state, the plug (136) is located at the upper part of the connection between the first bypass cavity (122) and the switch cavity (137), the first bypass cavity (122) is communicated with the T oil return port (114) through the switch cavity (137).

3. The load sensing combination valve of claim 2, wherein, The first sealing ring (133) is installed between the mounting seat (131) and the valve body (110), the second sealing ring (134) is arranged between the mounting column (132) and the mounting seat (131), and the third sealing ring (135) is arranged between the plug (136) and the switch cavity (137).

4. The load sensing combination valve of claim 1, wherein, The hydraulic lock (140) comprises an upper lock cavity (148) and a lower lock cavity (1493) arranged at the top of the valve body (110), the bottom of the upper lock cavity (148) is communicated with the left end of the second working cavity (151), the top of the lower lock cavity (1493) is communicated with the left end of the second working cavity (151), the first valve core (144) capable of sliding up and down and plugging the lower lock cavity (1493) is installed in the upper lock cavity (148), the second valve core (147) capable of fixing the first valve core (144) upward is slidingly installed at the position below the first valve core (144) of the valve body (110), the reset mechanism for abutting against the first valve core (144) downward is further installed in the upper lock cavity (148) above the first valve core (144).

5. The load sensing combination valve of claim 4, wherein, The reset mechanism comprises a top seat (141) arranged at the top of the upper lock cavity (148) and fixedly connected with the valve body, the bottom end of the top seat is fixedly connected with the first spring (142), and the lower end of the first spring (142) is fixedly connected with the first valve core (144).

6. The load sensing combination valve of claim 5, wherein, The top of the first valve core (144) is provided with a clamping groove (149), the bottom surface of the clamping groove (149) is fixedly provided with a baffle (143), the bottom end of the first spring (142) is fixedly connected with the baffle (143), the middle part of the first valve core (144) is provided with a mounting hole (1491) in communication with the clamping groove (149), the bottom of the first valve core (144) is provided with a top hole (1492) in communication with the mounting hole (1491), the mounting hole (1491) is provided with a second spring (145), the top end of the second spring (145) is fixedly connected with the baffle (143), the bottom end of the second spring (145) is fixedly connected with a steel ball (146), when the steel ball (146) is located at the lowermost part of the mounting hole (1491), the steel ball (146) can completely block the top hole (1492), the top of the second valve core (147) is provided with an upward protrusion, when the second valve core (147) moves upward, the protrusion can pass through the top hole (1492) and lift the steel ball (146) up.

7. The load sensing combination valve of claim 6, wherein, The switching valve cavity (113) is sequentially provided with a first cavity (190) in communication with one end of the second oil inlet cavity (172), a second cavity (191) in communication with the first working cavity (121), a third cavity (192) in communication with the oil return cavity (115), a fourth cavity (193) in communication with the lower locking cavity (1493), a fifth cavity (194) in communication with the other end of the second oil inlet cavity (172) and a sixth cavity (195) in communication with the first oil inlet cavity (171) from left to right; the valve rod (111) is provided with a first groove (196) capable of controlling the on-off of the first cavity (190) and the second cavity (191) and the second cavity (191) and the third cavity (192), a second groove (197) for controlling the on-off of the third cavity (192) and the fourth cavity (193), the fourth cavity (193) and the fifth cavity (194), a third groove (198) for controlling the on-off of the fifth cavity (194) and the sixth cavity (195) and a fourth groove (199).

8. The load sensing combination valve of claim 7, wherein, The bottom of the second valve core (147) is in contact with the second groove (197), the bottom of the second valve core (147) is hemispherical, and the right side wall of the second groove (197) is inclined, when the valve rod (111) is in the first state, the bottom of the second valve core (147) is located at the bottom of the slope.

9. The load sensing combination valve of claim 1, wherein, The valve body (110) is further provided with an overflow valve (153) at a position above the valve rod (111), the second working cavity (151) is communicated with a second bypass cavity (152), the second bypass cavity (152) is communicated with an overflow port (154) through the overflow valve (153); the first oil inlet cavity (171) is provided with a pressure compensation valve (160) for controlling the opening and closing thereof.

10. The load sensing combination valve according to any one of claims 1 to 9, wherein The driving mechanism (100) comprises a shell (109) fixedly installed on one side of the valve body (110), a motor (101) fixedly installed at the bottom of the shell (109), a lead screw (105) connected with the output end of the motor (101) through gear transmission, a threaded sleeve (106) threadedly matched with the lead screw (105), and the valve rod (111) fixedly connected with one end of the threaded sleeve (106) away from the lead screw (105).

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