Bypass type reversing valve with lock
By designing a bypass-type lockable directional valve, the complex structure and inconvenient maintenance of mechanical locks in the hydraulic systems of large tractors were solved, enabling convenient installation and maintenance of mechanical locks, preventing static settlement, and improving ease of use and sealing.
Patent Information
- Application Number
- CN202520726490.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-04-17
AI Technical Summary
In existing hydraulic systems of large tractors or construction machinery, the directional valves of the multi-way valve-driven lifting mechanism are prone to static settling due to leakage. Furthermore, the mechanical locks are complex in structure, inconvenient to process and install, and require disassembly of the oil pipes during maintenance.
Design a bypass-type lockable directional valve. By setting a valve sleeve and screw cap with an inner hole edge in the connecting oil circuit between the working oil port and the oil inlet, combined with a return spring, limit plug and pilot valve core, a mechanical lock is achieved without disassembling the oil pipe for replacement or maintenance. It has a simple structure and good sealing performance.
It enables convenient installation and maintenance of mechanical locks, avoids disassembly of oil pipes, reduces costs, effectively prevents static settlement, and improves ease of use and sealing effect.
Smart Images
Figure CN223839448U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a lockable directional valve, and more particularly to a bypass lockable directional valve. Background Technology
[0002] The multi-way valve used in the hydraulic system of large tractors or other construction machinery contains several directional valves, each of which drives a corresponding attachment to achieve different functions. Currently, the directional valve driving the lifting mechanism in the multi-way valve can realize the functions of mast lifting, neutral position, lowering, and floating. When its slide valve is in the neutral position and an overpressure state occurs, it is prone to static settlement due to leakage. To prevent static settlement, a mechanical lock needs to be installed in the oil circuit. Existing mechanical locks are mostly directly inserted into the working oil port. While the mechanical lock is working, in order to ensure normal oil flow in the oil port, the valve sleeve structure of the mechanical lock is relatively complex. Its processing and installation are inconvenient and costly. In addition, the working oil port needs to be connected to the oil pipe. Once the mechanical lock is replaced or repaired, the oil pipe needs to be disassembled, which is inconvenient to use. Summary of the Invention
[0003] The purpose of this utility model is to address the above-mentioned shortcomings of the prior art by providing a bypass-type lockable directional valve with a simple structure. It is not only easy to process and install, and has low cost, but also does not require disassembling the oil pipe of the working oil port for mechanical lock replacement or maintenance, making it convenient to use.
[0004] To achieve the above objectives, this utility model provides a bypass-type lockable directional valve, comprising a valve body, an oil inlet, an oil return, two working oil ports, and a slide valve disposed within the valve body. Its key feature is that a valve sleeve with an inner bore edge is provided in the oil passage connecting at least one working oil port and the oil inlet; a screw cap with an inner cavity is fixedly connected to the rear end of the valve sleeve, and the screw cap is fixedly connected to the valve body; a guide seat is fixedly provided in the front section of the oil passage connecting the front side of the valve sleeve, and a push rod is slidably disposed within the guide seat; a rear top conical surface that cooperates with the push rod is provided on the slide valve; a valve core with an inner bore edge is slidably disposed within the valve sleeve, and a limiting plug with an inner cavity is fixedly connected to the rear end of the valve core. The front end of the stop plug has an axial clearance with the inner edge of the valve core. The valve core has a tapered sealing surface that mates with the inner edge of the valve sleeve. A return spring is provided between the screw cap and the stop plug or the valve core. A pilot valve core is slidably provided in the valve core. The pilot valve core has a tapered sealing surface that mates with the inner edge of the valve core. A pilot valve spring is provided between the pilot valve core and the stop plug. The valve sleeve has a radial oil hole located behind its inner edge, connecting its inner cavity to the oil passage of the rear section. The valve core has a radial damping hole that connects the axial clearance and the radial oil hole. The stop plug has an oil passage that connects its inner cavity to the inner cavity of the screw cap.
[0005] The working principle of this utility model is as follows:
[0006] 1. Forward unlocking: When the sliding valve is moved to connect the oil inlet with the front section of the oil passage on the front side of the valve sleeve, the pressure oil acts on the front cavity of the valve core in the valve sleeve, pushes open the valve core, and the pressure oil enters the working oil port through the radial oil hole and the rear section of the oil passage to the actuator to complete the corresponding function.
[0007] 2. Neutral position: When the spool valve returns to the neutral position, the oil inlet is cut off from the connecting oil circuit, and the valve core is reset under the force of the reset spring. Its conical sealing surface is seated on the inner edge of the valve sleeve to achieve the purpose of locking and preventing leakage, and avoiding static settlement.
[0008] 3. Reverse Unlocking: After the oil from the actuator cylinder first enters the working port, it then passes through the rear connecting oil passage, radial oil hole, radial damping hole, axial clearance, limit plug inner cavity, and oil passage into the valve core rear cavity. At this time, the slide valve is pushed in the opposite direction to the return oil port corresponding to the working port. The rear top cone surface on the slide valve drives the push rod to move backward, opening the pilot valve core. At this time, the oil flows from the valve core rear cavity through the oil passage, limit plug inner cavity, annular cavity between the pilot valve core and the valve core inner hole, valve core front cavity, and front connecting oil passage into the corresponding return oil port. Due to the flow of oil, a pressure difference is generated when it flows through the radial damping hole on the valve core, so that the pressure in the valve core front cavity is greater than the force of the return spring, causing the valve core to move backward. The rear connecting oil passage is directly connected to the valve core front cavity through the radial oil hole, realizing reverse automatic unlocking without the need for external force.
[0009] The mechanical lock of this utility model is installed in the connecting oil circuit between the working oil port and the oil inlet, which does not affect the oil flow of the working oil port. Its structure is relatively simple, which is not only convenient to process and install, but also low in cost. Moreover, the mechanical lock can be replaced or repaired without disassembling the oil pipe of the working oil port, making it convenient to use.
[0010] As a further improvement of this utility model, a limiting post with a shoulder is provided in the inner cavity of the limiting plug on the rear side of the pilot valve core. The rear section of the pilot valve spring is sleeved outside the front section of the limiting post. The two ends of the pilot valve spring respectively contact the shoulders of the pilot valve core and the limiting post. The limiting post is provided with a radial hole and an axial hole connecting the radial hole and the rear end of the limiting post. The limiting post can control the stroke of the pilot valve core to prevent the pilot valve core from disengaging from the guide surface of the valve core inner hole.
[0011] As a further improvement of this utility model, the oil passage is a damping hole, which can increase the smoothness of valve core movement;
[0012] As a further improvement of this utility model, sealing rings are provided between the screw cap and the valve body, between the front section of the valve sleeve and the valve body, and between the rear section of the valve sleeve and the screw cap; this can improve the sealing effect of the mechanical lock.
[0013] As a further improvement of this utility model, the rear end of the valve sleeve is fixedly connected to a screw cap with an inner cavity by a thread, and the screw cap is fixedly connected to the valve body by a thread; this can realize the threaded insertion of the mechanical lock, which is convenient for installation and maintenance.
[0014] In summary, this utility model has a relatively simple structure, is not only easy to process and install, and has low cost, but also does not require disassembling the oil pipe of the working oil port for mechanical lock replacement or maintenance, making it convenient to use. Attached Figure Description
[0015] Figure 1 This is a hydraulic schematic diagram of an embodiment of the present invention.
[0016] Figure 2 This is a front view of the slide valve in the neutral position according to an embodiment of the present invention.
[0017] Figure 3 for Figure 2 A magnified view of a portion of the mechanical lock section.
[0018] Figure 4 For the corresponding Figure 3 The front view of the mechanical lock in the forward unlocking state.
[0019] Figure 5 For the corresponding Figure 3 The front view of the mechanical lock in its initial reverse unlocking state.
[0020] Figure 6 For the corresponding Figure 3 The front view of the mechanical lock in the reverse unlocking completed state. Detailed Implementation
[0021] The present invention will now be described in further detail with reference to the accompanying drawings. The terms "front end," "rear end," "front side," "rear side," "front segment," and "rear segment" used in this application are merely to indicate the relative positional relationship of the parts for ease of understanding and are not intended to limit the structure.
[0022] like Figures 1 to 3As shown, a bypass-type lockable directional valve of this embodiment includes a valve body 1, an oil inlet P, an oil return port T, two working ports A and B, and a slide valve 2 disposed within the valve body. A valve sleeve 3 with an inner bore edge is provided in the oil passage connecting the working port A and the oil inlet P. A screw cap 4 with an inner cavity is threadedly fixed to the rear end of the valve sleeve 3, and the screw cap 4 is threadedly fixed to the valve body 1. A guide seat 6 integrally connected to the valve body is fixed in the front section of the oil passage 5 on the front side of the valve sleeve 3. A push rod 7 is provided for sliding within the valve sleeve 6. A rear top conical surface 8 that mates with the push rod 7 is provided on the slide valve 2. A valve core 9 with an inner bore edge is provided for sliding within the valve sleeve 3. A limiting plug 10 with an inner cavity is threadedly fixed to the rear end of the valve core 9. An axial clearance 11 is provided between the front end of the limiting plug 10 and the inner bore edge of the valve core 9. The valve core 9 has a conical sealing surface that mates with the inner bore edge of the valve sleeve 3. A return spring 12 is provided between the screw cap 4 and the outer circular step of the limiting plug 10. The valve core 9 A pilot valve core 13 slides within the inner bore. The pilot valve core 13 has a tapered sealing surface that mates with the inner bore edge of the valve core 9. A limiting post 15 with a shoulder is located within the inner cavity of the limiting plug on the rear side of the pilot valve core 13. The rear section of a pilot valve spring 14 is fitted over the front section of the limiting post 15. Both ends of the pilot valve spring 14 contact the shoulders of the pilot valve core 13 and the limiting post 15, respectively. The limiting post 15 has a radial hole 16, and a connecting radial hole 16 connects the rear end of the limiting post. Axial hole 17; Valve sleeve 3 is provided with radial oil hole 18 located on the rear side of its inner hole edge, connecting its inner cavity with the rear section connecting oil passage 21; Valve core 9 is provided with radial damping hole 19 connecting axial clearance 11 and radial oil hole 18; Limit plug 10 is provided with oil passage hole 20 connecting its inner cavity with the inner cavity of screw cap, and oil passage hole 20 is a damping hole with variable inner diameter; Sealing rings are provided between screw cap 4 and valve body 1, between the front section of valve sleeve 3 and valve body 1, and between the rear section of valve sleeve 3 and screw cap 4;
[0023] When the conical sealing surface of valve core 9 and the inner hole edge of valve sleeve 3 are in contact, and the conical sealing surface of pilot valve core 13 and the inner hole edge of valve core 9 are in contact, a sealing pair is formed to ensure that there is no leakage; the limit plug 10 can control the stroke of valve core 9 to prevent valve core 9 from disengaging from the guide surface of the inner hole of valve sleeve 3.
[0024] The working principle of this utility model is as follows:
[0025] 1. Forward unlocking: such as Figure 4 As shown, when the forward movement of the slide valve 2 connects the oil inlet P to the front section of the connecting oil passage 5 on the front side of the valve sleeve 3, the pressure oil acts on the valve core front cavity in the valve sleeve 3 and pushes open the valve core 9. The pressure oil enters the working oil port A through the radial oil hole 18 and the rear section connecting oil passage 21 to the actuator to complete the corresponding function.
[0026] 2. Neutral position: such as Figure 3As shown, when the slide valve 2 returns to the neutral position, the oil inlet P is cut off from the upstream oil circuit 5, and the valve core 9 is reset under the action of the return spring 12. Its conical sealing surface is seated on the inner hole edge of the valve sleeve 3 to achieve the purpose of locking and preventing leakage, and can avoid static settlement.
[0027] 3. Reverse unlocking: such as Figure 5 As shown, the oil from the actuator cylinder first enters the working port A, and then sequentially passes through the rear connecting oil passage 21, radial oil hole 18, radial damping hole 19, axial clearance 11, the inner cavity of the limit plug 10, radial hole 16, axial hole 17, and oil passage 20 into the rear cavity of the valve core 9. At this time, the slide valve 2 is pushed in the opposite direction toward the return port T corresponding to the working port. Its rear top cone surface 8 drives the push rod 7 to move backward, opening the pilot valve core 13. At this time, the oil flows from the rear cavity of the valve core through the oil passage 20, axial hole 17, radial hole 16, the inner cavity of the limit plug 10, the annular cavity 22 between the pilot valve core 13 and the inner hole of the valve core, the front cavity of the valve core, and the front connecting oil passage 5 into the corresponding return port T. Figure 6 As shown, due to the flow of oil, a pressure difference is generated when it flows through the radial damping hole 19 on the valve core 9, which causes the pressure in the front cavity of the valve core to be greater than the force of the return spring 12, causing the valve core 9 to move backward. The rear section connecting oil circuit 21 is directly connected to the front cavity of the valve core through the radial oil hole 18, realizing reverse automatic unlocking without the need for external force.
[0028] The mechanical lock of this utility model is located in the connecting oil circuit between the working oil port A and the oil inlet 9, without affecting the oil flow of the working oil port. Its structure is relatively simple. The mechanical lock is not only easy to process, install and maintain, and has low cost through threaded insertion, but also does not require disassembling the oil pipe of the working oil port for replacement or maintenance, making it convenient to use. The limit post 15 can control the stroke of the pilot valve core 13 to prevent the pilot valve core 13 from disengaging from the guide surface of the valve core inner hole. Its oil passage hole 20 is a damping hole, which can increase the smoothness of the movement of the valve core 9. Each sealing ring can improve the sealing effect of the mechanical lock.
[0029] Depending on the working conditions, this utility model can also be equipped with mechanical locks in the oil circuit connecting the two working oil ports and the oil inlet.
Claims
1. A bypass-type lockable directional control valve, comprising a valve body, an oil inlet, an oil return port, two working ports, and a spool valve disposed within the valve body, characterized in that... A valve sleeve with an inner bore edge is provided in the oil passage connecting at least one working port and the oil inlet. A screw cap with an inner cavity is fixedly connected to the rear end of the valve sleeve, and the screw cap is fixedly connected to the valve body. A guide seat is fixedly provided in the front section of the oil passage connecting the front side of the valve sleeve. A push rod is slidably provided in the guide seat. A rear top cone surface that cooperates with the push rod is provided on the slide valve. A valve core with an inner bore edge is slidably provided in the valve sleeve. A limit plug with an inner cavity is fixedly connected to the rear end of the valve core. The front end of the limit plug has an axial clearance with the inner bore edge of the valve core. The valve core has an inner bore that matches the valve sleeve. A tapered sealing surface with edge fit is provided, and a return spring is provided between the screw cap and the limit plug or valve core; a pilot valve core is provided slidingly in the valve core, and the pilot valve core has a tapered sealing surface that fits with the edge of the inner hole of the valve core, and a pilot valve spring is provided between the pilot valve core and the limit plug; the valve sleeve has a radial oil hole located on the rear side of its inner hole edge, connecting its inner cavity with the oil passage of the rear section, and the valve core has a radial damping hole that connects the axial clearance and the radial oil hole, and the limit plug has an oil passage that connects its inner cavity with the inner cavity of the screw cap.
2. A bypass-type lockable directional valve according to claim 1, characterized in that: The pilot valve core has a limiting post with a shoulder in the inner cavity of the limiting plug on the rear side. The rear section of the pilot valve spring is sleeved on the front section of the limiting post. The two ends of the pilot valve spring are in contact with the shoulders of the pilot valve core and the limiting post, respectively. The limiting post has a radial hole and an axial hole connecting the radial hole and the rear end of the limiting post.
3. A bypass type lockable directional valve according to claim 1 or 2, characterized in that: The oil passage is a damping orifice.
4. A bypass-type lockable directional valve according to claim 3, characterized in that: Sealing rings are provided between the screw cap and the valve body, between the front section of the valve sleeve and the valve body, and between the rear section of the valve sleeve and the screw cap.
5. A bypass-type lockable directional valve according to claim 4, characterized in that: The rear end of the valve sleeve is fixedly connected to a screw cap with an inner cavity by threads, and the screw cap is fixedly connected to the valve body by threads.