Automatic reset multi-way valve

Abstract

The utility model discloses an automatic reset multi-way valve which comprises an oil inlet valve body, an oil return valve body, more than one reversing valve and a reset reversing valve, wherein the reversing valves and the reset reversing valve are sequentially arranged between the oil inlet valve body and the oil return valve body; the reset reversing valve adopts a middle position reset spring positioning and working position steel ball positioning structure, once load pressure exceeds preset pressure determined by a pressure adjusting spring, a pressure signal pushes a cone valve to move backwards through a load pressure feedback oil way, oil returns to an oil return opening through a flow channel, a radial overflowing groove, a radial overflowing hole and the inner circle of a positioning sleeve, and the oil return opening is closed. When the flow flowing through the throttling flow channel is increased to enable the pressure difference generated at the two ends of the reset valve element to overcome the spring force acting on the positioning seat by the positioning spring, the sliding valve automatically returns to the neutral position under the action of the reset spring, so that energy is saved, consumption is reduced, abnormal reset caused by pressure fluctuation can be avoided, misoperation is prevented, and the application range is expanded.

Description

Technical Field

[0001] This utility model relates to a multi-way valve, and more particularly to an automatic reset multi-way valve. Background Technology

[0002] Multi-way valves used in the hydraulic systems of large tractors, compactor garbage trucks, or other construction machinery contain several directional valves. Each directional valve drives a corresponding attachment to perform operations such as gantry lifting, compression, harvesting, bucket turning, and digging. Currently, the directional valves driving the lifting mechanism in multi-way valves can realize the functions of gantry lifting, neutral position, lowering, and floating. In the working position, when an overpressure condition occurs, the slide valve needs to be reset. Without an overpressure reset function, after the lifting stroke of the actuator cylinder is completed, the system will continue to operate in a high-pressure unloading state with the safety valve open, resulting in high energy loss, severe system heat generation, and potential other issues. It can damage the corresponding pipe fittings; the traditional reset methods of directional valves are spring reset, pilot hydraulic control, etc., and the spool valve must be manually operated or controlled by cutting off the pilot oil source to return to the neutral position. The manual operation method requires the operating force to overcome the force of the reset spring, so the operating force is generally relatively large, especially for directional valves with larger diameters. To ensure that the spool valve can be reset quickly, the reset spring force must be designed to be larger, so the operating force is greater, which requires high labor intensity from the operator and has poor operating comfort; in addition, some directional valves have a single working state and limited application range. Summary of the Invention

[0003] The purpose of this utility model is to address the above-mentioned shortcomings of the prior art by providing an automatic reset multi-way valve, whose corresponding reversing valve can automatically reset when overpressure occurs, thereby saving energy and reducing consumption, avoiding abnormal reset caused by pressure fluctuations, preventing misoperation, and expanding the scope of application.

[0004] To achieve the above objectives, the automatic reset multi-way valve of this utility model includes an inlet valve body, a return valve body, and one or more directional valves and one or more reset directional valves sequentially disposed between the two. The inlet valve body is provided with a system inlet and a system return port. Each directional valve and reset directional valve includes a valve body, a slide valve, an end cover, an inlet, an inlet chamber, a return port, two working ports, a central unloading inlet, and a central unloading outlet. One end of each slide valve is connected to an operating component, and each inlet is connected to the system inlet. The valves are connected, with each return port connected to the system return port. The unloading outlet of the first valve body is connected to the unloading inlet of the second valve body, and the unloading outlet of the last valve body is connected to the bridge port of the return valve body. The characteristic feature is that the spool valve of the reset directional valve has an axial stepped hole and several radial holes connected to the stepped hole at one end near the end cover. Each radial hole contains a steel ball, the diameter of which is greater than the depth of the radial hole. A positioning sleeve is fixed to the outside of this end spool valve, and the inner circle of the positioning sleeve is spaced axially. Two or more arc-shaped grooves mate with the steel ball. The inner circle of the positioning sleeve on the inner side of each arc-shaped groove is radially spaced from the slide valve. The inner end of the inner circle of the positioning sleeve is connected to the oil return port. The slide valve has a load pressure feedback oil circuit connecting the oil inlet chamber and the inner end of the stepped hole. The inner end of a positioning pin is fixedly connected to the outer end of the stepped hole. The outer circle of the outer end of the positioning pin has a step. An inner spring seat and an outer spring seat slide on the outer circle of the positioning pin between the step and the end of the slide valve. A return spring is provided between the inner spring seat and the outer spring seat. A positioning seat and a reset valve core are slidably mounted in sequence within the stepped hole inside the positioning column. The reset valve core has a stepped flow channel with a throttling section. A pressure regulating spring is located in the inner section of the flow channel, and the pressure regulating spring contacts a cone valve in the stepped hole. The sealing surface of the cone valve seals the end of the load pressure feedback oil circuit. The reset valve core has a radial flow groove connected to the flow channel. The slide valve has a radial flow hole corresponding to the radial flow groove. The inner end of the positioning seat has a conical surface, and a positioning spring is located between the positioning column and the positioning seat.

[0005] The reset directional valve in this multi-way valve employs a structure with a neutral-position reset spring for positioning and a working-position steel ball for positioning. When the spool valve is moved so that the steel ball is positioned within an arc-shaped groove in the positioning sleeve, the spool valve remains in the reversing position. If a pressure difference exists between the two working ports, the connected actuator remains operational. Once the load pressure exceeds the preset pressure determined by the pressure regulating spring, the pressure signal is transmitted through the load pressure feedback oil circuit to push the cone valve backward. The oil flows back to the return port via the flow channel, radial flow groove, radial flow hole, and the inner circle of the positioning sleeve. When the flow rate through the throttling channel increases to the point that the pressure difference generated across the reset valve core can overcome the spring force exerted by the positioning spring on the positioning seat, the reset valve core and positioning seat are pushed outward. At this point, the steel ball is positioned by the reset spring. When the valve is pressed into the radial hole, the spool valve loses its positioning function on the axis and automatically returns to the neutral position under the action of the return spring. At the same time, the central unloading channel is opened, the cone valve closes, and the oil flowing through the channel is cut off. Therefore, the working blockage port is sealed off, and there is no pressure oil flowing in the channel, so the actuator stops moving. It can be seen that this directional valve can achieve automatic reset when overpressure occurs, thereby saving energy and reducing consumption. Moreover, the reset valve core is not directly pushed open by rigid parts such as push rods under the load pressure feedback pressure, but is unlocked by the pressure difference generated at both ends of the reset valve core through the change of flow rate. This can avoid abnormal reset caused by pressure fluctuations and prevent frequent reset and other misoperations. The central unloading channels of each directional valve are connected in sequence. When each valve is not working, it can provide oil to other devices through the bridge oil port, expanding the scope of use.

[0006] As a further improvement of this utility model, both the positioning seat and the positioning column are provided with through holes. A spring seat is provided in the flow channel of the reset valve core outside the pressure regulating spring. An adjusting rod passes through the through hole of the positioning seat and the outer section of the flow channel, and the inner end of the adjusting rod contacts the spring seat. The spring seat and the reset valve core are separated by a gap in both the radial and axial directions. The radial gap located outside the spring seat and between the adjusting rod and the reset valve core is the throttling flow channel. The outer end of the adjusting rod contacts the sealing plug in the through hole of the positioning column. An adjusting screw is provided on the outside of the sealing plug and is threadedly connected to the through hole of the positioning column. The outer end of the adjusting screw is provided with a washer and a locking nut. The opening pressure of the cone valve can be adjusted by the adjusting screw.

[0007] As a further improvement of this utility model, a one-way valve is provided between the oil inlet and the oil inlet chamber; this can maintain a certain working pressure at the working oil port and prevent oil backflow.

[0008] As a further improvement of this utility model, a single-acting or double-acting switching valve is provided between a working oil port and a return oil port in the valve body of the at least one directional valve; this enables the switching of the directional valve between single-acting and double-acting working states, further expanding its application range.

[0009] As a further improvement of this utility model, a safety valve is provided between the system oil inlet and the system oil return port; this can realize automatic unloading of the system under overpressure.

[0010] In summary, the reset directional valve of this utility model can automatically reset when there is overpressure, thereby saving energy and reducing consumption. It can also avoid abnormal reset caused by pressure fluctuations, prevent misoperation, and expand the scope of application. Attached Figure Description

[0011] Figure 1 This is a hydraulic schematic diagram of an embodiment of the present invention.

[0012] Figure 2 This is a top view of an embodiment of the present utility model.

[0013] Figure 3 for Figure 2 The right view.

[0014] Figure 4 for Figure 2 An enlarged cross-sectional view of the spool valve of the reset directional valve in the neutral position.

[0015] Figure 5 for Figure 4 The front view of the positioning sleeve.

[0016] Figure 6 for Figure 2 An enlarged cross-sectional view of the resetting directional valve in the lifted state.

[0017] Figure 7 for Figure 2 An enlarged cross-sectional view of the resetting directional valve in the descending state.

[0018] Figure 8 for Figure 2 Enlarged cross-sectional view of the directional valve. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings.

[0020] like Figure 1 , Figure 2 , Figure 3As shown, the automatic reset multi-way valve of this embodiment includes an inlet valve body 41, a return valve body 45, and two directional valves 42 and 43 sequentially disposed between the inlet valve body 41 and the return valve body 45, and a reset directional valve 44. The inlet valve body 41 is provided with a system inlet port P and a system return port T. A safety valve 46 is provided between the system inlet port P and the system return port T. The two directional valves 42 and 43 and the reset directional valve 44 each include a valve body, a slide valve, an end cover, an inlet port, an inlet chamber, a return port, two working ports, and a central unloading inlet. Each spool valve has an operating component connected to one end of its oil port and the central unloading outlet. The inlets of each directional valve 42-44 are connected to the system inlet P via internal oil passages. The return ports of each directional valve are connected to the system return port T via internal oil passages. The central unloading outlet of the preceding valve body is connected to the central unloading inlet of the following valve body. The central unloading outlet of the last side reset directional valve 44 is connected to the bridge port Px of the return valve body 45. A check valve 5 is provided between the inlet and the inlet chamber within the same valve body. Figure 4 , Figure 5As shown, the reset directional valve 44 includes a valve body 1, a slide valve 2, an end cover 3, an oil inlet P, an oil inlet chamber P2, an oil return port T, a central unloading oil inlet P0, a working oil port A3, a working oil port B3, and a central unloading oil outlet P1. A check valve 5 is provided between the oil inlet P and the oil inlet chamber P2. One end of the slide valve 2 is connected to a handle 4. The end of the slide valve 2 adjacent to the end cover is provided with an axial stepped hole and several radial holes connected to the stepped hole. Each radial hole is provided with a steel ball 6, the diameter of which is greater than the depth of the radial hole. A positioning sleeve 9 is fixed to the outside of this end of the slide valve 2 by a pressure plate 7 and a connecting screw 8. The inner circle of the positioning sleeve 9 is provided with three arcs along the axial direction that cooperate with the steel ball 6. The shaped grooves 11, 12, and 13, with the inner circle of the positioning sleeve 9 on the inner side of each arc-shaped groove being radially spaced from the slide valve 2, the inner end of the inner circle of the positioning sleeve 2 is connected to the oil return port T, and the outer end of the inner circle of the positioning sleeve 9 is provided with a sealing ring 14; the slide valve 2 is provided with a load pressure feedback oil circuit 15 connecting the oil inlet chamber P2 and the inner end of the stepped hole; the inner end of a positioning post 16 is fixedly connected to the outer end of the stepped hole of the slide valve 2 by threads, and the outer circle of the outer end of the positioning post 16 is integrally fixed with a step, and an inner spring seat 18 and an outer spring seat 19 are slidably fitted on the outer circle of the positioning post 16 between the step and the end of the slide valve 2, and a return spring 20 is provided between the inner spring seat 18 and the outer spring seat 19; the step on the inner side of the positioning post 16... A positioning seat 17 and a reset valve core 21 are sequentially slidably arranged within the hole. Both the positioning seat 17 and the positioning post 16 have through holes. The reset valve core 21 has a stepped flow channel. A pressure regulating spring 22 is located in the inner section of the flow channel. The pressure regulating spring 22 contacts a cone valve 23 in the stepped hole on its inner side. The sealing surface of the cone valve 23 seals the end of the load pressure feedback oil circuit 15. A spring seat 24 is located in the flow channel of the reset valve core 21 outside the pressure regulating spring 22. The outer end of the pressure regulating spring 22 contacts the spring seat 24. An adjusting rod 25 passes through the through hole of the positioning seat 17 and the outer section of the flow channel, and the inner end of the adjusting rod 25 contacts the spring seat 24. The spring seat 24 in the flow channel and the reset valve core 21 are radially and axially aligned. The valves are arranged with gaps, and the smaller radial gap between the adjusting rod 25 and the reset valve core 21, located outside the spring seat 24, forms a throttling channel; the outer end of the reset valve core 21 is provided with a radial flow groove 26 connected to the flow channel; the slide valve 2 is provided with a radial flow hole 27 corresponding to the radial flow groove 26; the inner end of the positioning seat 17 is provided with a conical surface, and a positioning spring 28 is provided between the positioning post 16 and the positioning seat 17; the outer end of the adjusting rod 25 contacts the sealing plug 29 in the through hole of the positioning post 16, the outer circle of the sealing plug 29 is provided with a sealing ring 30, and the outer side of the sealing plug 29 is provided with a pressure adjusting screw 31 that is threadedly connected to the through hole of the positioning post, and the outer end of the pressure adjusting screw 31 is provided with a washer 32 and a locking nut 33; Figure 1 , Figure 8 As shown, a single- or double-acting switching valve 47 is provided between the working oil port B1 (or B2) and the return oil port T of the two directional valves 42 and 43;

[0021] The reset directional valve 44 in this multi-way valve adopts a structure with a neutral position reset spring for positioning and a working position steel ball for positioning. When the slide valve 2 is moved so that each steel ball 6 is in one of the three arc-shaped grooves 11, 12, and 13 respectively, it corresponds to the lifting, lowering, and floating working states respectively. When the slide valve 2 is in the neutral position, each steel ball 6 is located between the two arc-shaped grooves 11 and 12 and is positioned by the reset spring 20 (e.g., ...). Figure 4 (as shown)

[0022] The working process of this utility model is as follows:

[0023] 1. Lifting position

[0024] like Figure 5 , Figure 6 As shown, by manually pulling the slide valve 2 to the right using the operating handle 4, the steel ball 6 overcomes the resistance of the return spring 20 and enters the arc-shaped groove 11 of the positioning sleeve 9, and is positioned under the action of the positioning spring 28. At this time, the operating handle 4 is released, the slide valve 2 is in the positioning state, the hydraulic system supplies oil to the lifting cylinder of the actuator, and the lifting cylinder is in the continuous working state.

[0025] Reset: In the lifted position, chamber P is connected to working port B3. The pressure in chamber B3 (i.e., the load pressure) acts on the front end of cone valve 23 through the load pressure feedback oil circuit 15 of slide valve 2, and oil returns through working port A3. When the load pressure value is greater than the preset pressure determined by the pressure regulating spring 22, the pressure signal pushes cone valve 23 outward through the load pressure feedback oil circuit 15. The oil flows through the flow channel, throttling channel, radial flow groove 26, radial flow hole 27 and inner circle of positioning sleeve 9 (e.g., ...) in the reset valve core 21. Figure 6 (As shown by the middle arrow) Returning to the return port T, when the flow rate through the throttling channel increases to the point that the pressure difference generated at both ends of the reset valve core 21 can overcome the spring force of the positioning spring 28 acting on the positioning seat 17, the reset valve core 21 and the positioning seat 17 are pushed to the outward end. At this time, the steel ball 6 is pressed into the radial hole by the positioning sleeve 9 along the conical surface of the positioning seat 17 under the action of the reset spring 20. The slide valve 2 loses its positioning function on the axis and automatically returns to the middle position under the action of the reset spring 20. At the same time, the central unloading inlet P0 and the central unloading outlet P1 are connected, the central unloading channel is opened, the cone valve 23 is closed, and the oil flowing through the channel is cut off. Therefore, the working oil port B3 is sealed off, there is no pressure oil flowing in the channel, and the lifting cylinder stops rising.

[0026] 2. Descending position:

[0027] like Figure 5 , Figure 7As shown, after the spool valve 2 reverses, the steel ball 6 enters the arc-shaped groove 12 of the positioning sleeve 9; the P chamber is connected to the working oil port A3, and the working oil port B3 returns oil. There is a pressure difference between the two working oil ports. The hydraulic system supplies oil to the other chamber of the lifting cylinder of the actuator, and the lifting cylinder is in the lowering state; the pressure in chamber A3 acts on the front end of the cone valve 23 through the load pressure feedback oil circuit 15 of the spool valve 2; similarly, when the load pressure value is greater than the preset pressure determined by the pressure regulating spring 22, the pressure signal pushes the cone valve 23 to move outward through the load pressure feedback oil circuit 15. The oil returns to the return oil port T through the flow channel, throttling flow channel, radial flow groove 26, radial flow hole 27 and inner circle of the positioning sleeve 9 in the reset valve core 21. When the flow rate through the throttling flow channel increases to the point that the pressure difference generated at both ends of the reset valve core 21 can overcome the pressure difference, the oil flow returns to the return oil port T. When the positioning spring 28 acts on the positioning seat 17, the reset valve core 21 and the positioning seat 17 are pushed to move outward. At this time, the steel ball 6 is pressed into the radial hole by the positioning sleeve 9 along the conical surface of the positioning seat 17 under the action of the reset spring 20. The slide valve 2 loses its positioning function on the axis and automatically returns to the middle position under the action of the reset spring 20. At the same time, the central unloading oil inlet P0 and the central unloading oil outlet P1 are connected. The central unloading flow channel is opened, the cone valve 23 is closed, and the oil flowing through the flow channel is cut off. Therefore, the working oil port A3 is sealed off, and there is no pressure oil flowing in the flow channel. The lifting cylinder stops descending.

[0028] 3. Floating position

[0029] When the slide valve 2 is in a floating state, such as Figure 1 As shown, the two working oil ports A3 and B3 are connected and have equal pressure. At this time, the lifting cylinder is always in a follow-up state, and there is no pressure difference between the two ends of the load pressure feedback oil circuit 15, so there is no need to achieve automatic reset.

[0030] In summary, when the resetting directional valve 44 is in operation, if there is a pressure difference between the two working ports, once the load pressure exceeds the preset pressure determined by the pressure regulating spring, the pressure signal pushes the cone valve backward through the load pressure feedback oil circuit. When the flow rate through the throttling channel increases to the point that the pressure difference generated at both ends of the resetting valve core can overcome the spring force of the positioning spring on the positioning seat, the resetting valve core and the positioning seat are pushed to the outward end. At this time, the steel ball automatically returns to the neutral position under the action of the resetting spring, which can realize automatic resetting when overpressure occurs, thereby saving energy and reducing consumption. Moreover, the resetting valve core is not directly pushed open by rigid parts such as push rods under the load pressure feedback pressure, but is opened by the pressure difference generated at both ends of the resetting valve core due to the change in flow rate. This can avoid abnormal resetting caused by pressure fluctuations and prevent frequent resetting and other misoperations, making the resetting action stable and reliable, and ensuring a stable and normal working state.

[0031] The opening pressure of the cone valve can be adjusted by rotating the pressure adjusting screw 31;

[0032] Each directional valve 42-44 maintains a certain working pressure at its working port and prevents oil backflow through its respective check valve 5. When the spool valves of each directional valve 42-44 are in the neutral position, their respective unloading inlet and outlet ports are connected, and the unloading flow channels are sequentially connected. When the valves are not working, they can supply oil to other devices through the bridge port Px, thus expanding the scope of application. For the two directional valves 32 and 43, the single-acting / double-acting switching valve 47 is locked by turning it clockwise, which is in double-acting mode. The single-acting / double-acting switching valve 47 is opened by turning it counterclockwise, which is in single-acting mode. This can meet the needs of both working conditions and further expand the scope of application.

Claims

1. An automatic reset multi-way valve, comprising an inlet valve body, a return valve body, and one or more directional control valves and one or more reset directional control valves sequentially disposed between the two; the inlet valve body is provided with a system inlet and a system return port; each directional control valve and reset directional control valve includes a valve body, a spool valve, an end cover, an inlet, an inlet chamber, a return port, two working ports, a central unloading inlet, and a central unloading outlet; one end of each spool valve is connected to an operating component; each inlet is connected to the system inlet; each return port is connected to the system return port; the central unloading outlet of the preceding valve body is connected to the central unloading inlet of the following valve body; and the central unloading outlet of the last valve body is connected to the bridge port of the return valve body; characterized in that... The spool valve of the reset directional valve has an axial stepped hole and several radial holes connected to the stepped hole at one end near the end cover. Each radial hole contains a steel ball, the diameter of which is greater than the depth of the radial hole. A positioning sleeve is fixed to the outside of this end of the spool valve. The inner circle of the positioning sleeve has two or more arc-shaped grooves spaced axially to mate with the steel balls. The inner circle of the positioning sleeve on the inner side of each arc-shaped groove is radially spaced from the spool valve. The inner end of the inner circle of the positioning sleeve is connected to the return port. The spool valve has a load pressure feedback oil circuit connecting the oil inlet chamber and the inner end of the stepped hole. The inner end of a positioning pin is fixed to the outer end of the stepped hole. The outer circle of the outer end of the positioning pin has a step. This step connects to the end of the spool valve... An inner spring seat and an outer spring seat slide on the outer circle of the positioning post between the ends, and a return spring is provided between the inner spring seat and the outer spring seat; a positioning seat and a return valve core slide sequentially in the stepped hole inside the positioning post; the return valve core has a stepped hole-shaped flow channel, and a throttling flow channel is provided in the flow channel; a pressure regulating spring is provided in the inner section of the flow channel; the pressure regulating spring contacts the cone valve in the stepped hole; the sealing surface of the cone valve seals the end of the load pressure feedback oil circuit; the return valve core has a radial flow groove connected to the flow channel; the slide valve has a radial flow hole corresponding to the radial flow groove; the inner end of the positioning seat has a conical surface, and a positioning spring is provided between the positioning post and the positioning seat.

2. The automatic reset multi-way valve according to claim 1, characterized in that: Both the positioning seat and the positioning column are provided with through holes. A spring seat is provided in the flow channel of the reset valve core outside the pressure regulating spring. An adjusting rod passes through the through hole of the positioning seat and the outer section of the flow channel, and the inner end of the adjusting rod contacts the spring seat. The spring seat and the reset valve core are separated by a gap in both the radial and axial directions. The radial gap between the adjusting rod and the reset valve core located outside the spring seat is the throttling flow channel. The outer end of the adjusting rod contacts the sealing plug in the through hole of the positioning column. The outer side of the sealing plug is provided with a pressure regulating screw that is threadedly connected to the through hole of the positioning column. The outer end of the pressure regulating screw is provided with a washer and a locking nut.

3. An automatic reset multi-way valve according to claim 1 or 2, characterized in that: Each valve body is equipped with a one-way valve between its oil inlet and oil inlet chamber.

4. The automatic reset multi-way valve according to claim 3, characterized in that: A single- or double-acting switching valve is provided between a working port and a return port within the valve body of at least one directional valve.

5. An automatic reset multi-way valve according to claim 4, characterized in that: A safety valve is installed between the system's oil inlet and the system's oil return port.

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