Direct-acting multi-way valve driven by electro-hydraulic pump

Abstract

The electro-hydraulic pump drive direct-acting type multi-way valve comprises a hydraulic pump, a motor, a valve body, a linear differential transformer, a piston fixing type hydraulic cylinder, a valve element and a reset mechanism, the valve element is inserted into the valve body in a left-right sliding mode, and the linear differential transformer, the piston fixing type hydraulic cylinder, the valve element and the reset mechanism are sequentially connected from left to right; the motor is connected with the hydraulic pump, and the piston fixed type hydraulic cylinder comprises a fixed type piston and a cylinder body connected outside the fixed type piston in a sliding and sleeving mode. The cylinder body of the piston fixing type hydraulic cylinder is directly driven through the electro-hydraulic pump, then the cylinder body drives the valve element to move, the linear differential transformer is used for detecting the position of the valve element in real time to form closed-loop control, traditional complex structures of electromagnet driving, mechanical transmission and external hydraulic pilot are omitted, and the system is more compact.

Description

Technical Field

[0001] This invention relates to the field of electro-hydraulic pump-driven direct-acting multi-way valve. Background Technology

[0002] Hydraulic multi-way valves are used in hydraulic systems to control fluid direction, flow distribution, or pressure control, and are key components of hydraulic transmission and control systems. Currently, various mature technologies have been developed for the actuation methods and structural designs of multi-way valves; however, some technical defects and limitations still exist in practical applications, providing room for improvement through new actuation solutions.

[0003] Existing valve core actuation methods for multi-way valves mainly include manual actuation, electromagnetic actuation, hydraulic pilot actuation, electric motor mechanical transmission, and pneumatic or new material actuation. While manual operation is simple in structure, it cannot meet the demands of automation and precise control. Electromagnetic direct-acting actuation is convenient and has a fast response, but is limited by electromagnetic force, making it difficult to drive valve cores with large strokes and high thrust. Electromagnetic or hydraulic pilot actuation can achieve large-flow valve core control, but it requires an external hydraulic station, resulting in a large and complex system with extremely high requirements for oil cleanliness, making it prone to valve core jamming due to contamination. Electric motors combined with lead screws or cams can achieve electrification, but lead screws have safety hazards such as self-locking and failure to return to their original position after power failure, while cams are limited by geometric conditions, making it difficult to balance large strokes and compact size. Pneumatic actuation offers fast response but limited thrust, and the compressibility of compressed air makes precise control difficult. New actuation methods such as piezoelectric or shape memory alloys offer advantages in terms of small size and fast response, but their driving force is extremely small and stroke is limited, making them difficult to apply to the actual working conditions of large-flow multi-way valves. In summary, all existing drive methods have shortcomings to varying degrees, making it difficult to simultaneously achieve comprehensive performance such as thrust, stroke, accuracy, safety, and compact structure. Summary of the Invention

[0004] The purpose of this invention is to provide an electro-hydraulic pump-driven direct-acting multi-way valve to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An electro-hydraulic pump-driven direct-acting multi-way valve includes a hydraulic pump, a motor, a valve body, a linear differential transformer, a piston-fixed hydraulic cylinder, a valve core, and a reset mechanism. The valve core is slidably inserted into the valve body from left to right. The linear differential transformer, the piston-fixed hydraulic cylinder, the valve core, and the reset mechanism are connected sequentially from left to right. The motor is connected to the hydraulic pump. The piston-fixed hydraulic cylinder includes a fixed piston and a cylinder body slidably sleeved outside the fixed piston. The electro-hydraulic pump-driven direct-acting multi-way valve is configured as follows: the motor-driven hydraulic pump provides high-pressure oil to the piston-fixed hydraulic cylinder, causing the cylinder to move the linear differential transformer and the valve core to the left together. The reset mechanism uses elasticity to help the valve core reset to the right. The linear differential transformer is used to obtain the position feedback signal of the valve core, thereby realizing closed-loop control of the valve core position.

[0006] Furthermore, it also includes a housing fixedly connected to the left side of the valve body, and the piston-fixed hydraulic cylinder and the hydraulic pump are respectively inserted into the housing.

[0007] Furthermore, the piston-fixed hydraulic cylinder also includes a fixed seat fixedly connected to the housing. The fixed piston passes through the fixed seat and is fixedly connected to the fixed seat. A left chamber is provided on the left side of the cylinder body, which is in sealing and sliding fit with the left end of the fixed piston. A hollow groove is provided in the middle of the cylinder body, and the fixed seat is located in the hollow groove. A right chamber is provided on the right side of the cylinder body, which is in sealing and sliding fit with the right end of the fixed piston. A left oil passage is provided on the left side of the fixed piston, and a right oil passage is provided on the right side of the fixed piston. A left channel is provided on the fixed seat, which is connected to the oil inlet of the hydraulic pump, and a right channel is provided on the fixed seat, which is connected to the oil outlet of the hydraulic pump. The left channel, the left oil passage, and the left chamber are connected in sequence, and the right channel, the right oil passage, and the right chamber are connected in sequence.

[0008] Furthermore, the outer wall of the fixed piston is provided with a left annular groove and a right annular groove on the left and right sides respectively. The left channel is connected to the left oil passage through the left annular groove, and the right channel is connected to the right oil passage through the right annular groove.

[0009] Furthermore, a transformer connector is sleeved on the left end of the cylinder, the transformer connector is connected to a linear differential transformer, and a left chamber is formed between the left end of the cylinder and the transformer connector. A push rod is sleeved on the right end of the cylinder, the push rod is connected to a valve core, and a right chamber is formed between the right end of the cylinder and the push rod.

[0010] Furthermore, the reset mechanism includes a valve stem and an elastic element. The valve stem is fixedly connected to the right end of the valve core, and the elastic element pushes or pulls the valve stem to the right.

[0011] Furthermore, the reset mechanism also includes a left spring seat and a right spring seat respectively disposed at the left and right ends of the valve stem. The left spring seat is slidably engaged with the valve stem, and the right spring seat is fixedly connected to the valve stem. The elastic element is a spring sleeved on the valve stem, and the spring is connected between the left spring seat and the right spring seat.

[0012] Furthermore, the reset mechanism also includes a sealing end cap disposed at the right end of the valve body, which covers the valve stem, spring, left spring seat, and right spring seat.

[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention directly drives the cylinder body of a piston-fixed hydraulic cylinder via an electro-hydraulic pump, which in turn drives the valve core. A linear differential transformer is used to detect the valve core position in real time, forming a closed-loop control system. This eliminates the complex structure of traditional electromagnet drives, mechanical transmissions, and external hydraulic pilots, resulting in a more compact system. Due to the direct-acting hydraulic cylinder, it provides greater driving force and a longer stroke, ensuring stable and reliable valve core operation even under high pressure and high flow conditions. Furthermore, the pump-controlled cylinder design eliminates the need for an external oil source, simplifying installation and maintenance. Even with contaminated oil, it maintains valve core flexibility, effectively preventing jamming. In addition, a reset mechanism returns the valve core to its neutral position upon power failure, improving system safety and reliability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the electro-hydraulic pump-driven direct-acting multi-way valve of the present invention; Figure 2 This is a longitudinal cross-sectional structural diagram of the electro-hydraulic pump-driven direct-acting multi-way valve of the present invention; Figure 3 This is a schematic diagram of the piston-fixed hydraulic cylinder in this invention; Figure 4 This is a cross-sectional view of the piston-fixed hydraulic cylinder in this invention along its longitudinal centerline; Figure 5 This is a partial cross-sectional view of the piston-fixed hydraulic cylinder of the present invention at the center of the longitudinal oil passage; Figure 6 This is an enlarged cross-sectional view of the reset mechanism in this invention.

[0015] In the diagram: Hydraulic pump-1, Motor-2, Valve body-3, Linear differential transformer-4, Housing-5, Piston-fixed hydraulic cylinder-6, Valve core-7, Seal-10, Working port A-11, Working port B-12, Return port T-13, Inlet port P-14, Through hole-15, Sealing end cap-16, Cylinder body-200, Piston-201, Fixed seat-202, Transformer connector-203, Push rod-204, Snap ring-206, Right oil passage-301, Left oil passage-302, Annular groove-304, Left chamber-305, Right chamber-306, Sealing groove-307, Left channel-401, Plug-402, Sealing ring-403, Fixed plate through hole-404, Left spring seat-101, Valve stem-102, Spring-103, Right spring seat-104, Retaining ring-105. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-6 An electro-hydraulic pump-driven direct-acting multi-way valve includes a hydraulic pump 1, a motor 2, a valve body 3, a linear differential transformer 4, a piston-fixed hydraulic cylinder 6, a valve core 7, and a reset mechanism. The valve core 7 is slidably inserted into the valve body 3. The linear differential transformer 4, the piston-fixed hydraulic cylinder 6, the valve core 7, and the reset mechanism are connected sequentially from left to right. The motor 2 is preferably a brushless motor. The motor 2 is connected to the hydraulic pump 1. The piston-fixed hydraulic cylinder 6 includes a fixed piston 201 and a cylinder body 200 that is slidably sleeved outside the fixed piston 201.

[0018] Motor 2 drives hydraulic pump 1 to provide high-pressure oil to piston-fixed hydraulic cylinder 6, causing cylinder body 200 to move linear differential transformer 4 and valve core 7 to the left together. The reset mechanism uses elasticity to help valve core 7 reset to the right. Linear differential transformer 4, also called linear displacement sensor, has its iron core fixedly connected to cylinder body 200. The iron core, piston-fixed hydraulic cylinder 6, and valve core 7 move synchronously. Linear differential transformer 4 is used to obtain the position feedback signal of valve core 7, thereby realizing closed-loop control of valve core 7 position.

[0019] Continue reading Figure 1 and Figure 2 The invention also includes a housing 5 that is bolted to the left side of the valve body 3, a piston-fixed hydraulic cylinder 6 that is inserted into the upper end of the housing 5, and a hydraulic pump 1 that is inserted into the inside of the housing 5.

[0020] Continue reading Figures 2-4 The piston-fixed hydraulic cylinder 6 also includes a fixed seat 202 fixedly connected to the housing 5. The fixed piston 201 passes through the fixed seat 202 and is fixedly connected to the fixed seat 202. The cylinder body 200 has a hollow groove in the middle, and the fixed seat 202 is located in the hollow groove. The left side of the cylinder body 200 is provided with a left chamber 305 that is in sealing and sliding cooperation with the left end of the fixed piston 201. The right side of the cylinder body 200 is provided with a right chamber 306 that is in sealing and sliding cooperation with the right end of the fixed piston 201. The left side of the fixed piston 201 is provided with a left oil passage 302, and the right side of the fixed piston 201 is provided with a right oil passage 301. The fixed seat 202 is provided with a left channel 401 connected to the oil inlet of the hydraulic pump 1 and a right channel connected to the oil outlet of the hydraulic pump 1. The left channel 401, the left oil passage 302 and the left chamber 305 are connected in sequence, and the right channel, the right oil passage 301 and the right chamber 306 are connected in sequence.

[0021] Further reading Figures 2-5 The piston-fixed hydraulic cylinder 6 is fixed by bolts through the through hole 404 of the fixing seat 202 to the housing 5, and sealed by the sealing ring 403; the fixing seat 202 and the fixed piston 201 are fixed by a snap ring 206, and sealed by the sealing groove 307 in conjunction with the sealing ring. The high-pressure oil output by the hydraulic pump 1 passes through the internal oil passage of the housing 5, then through the left channel 401 of the fixing seat 202 into the left annular groove 304, and then through the left oil passage 302 of the fixed piston 201 into the chamber 305 between the cylinder body 200 and the piston 201, thereby driving the cylinder body 200 to move. The low-pressure oil flows back along the opposite path to ensure system circulation.

[0022] Continue reading Figure 4 and Figure 5 The fixed piston 201 has a left annular groove 304 and a right annular groove 303 on its outer wall. The left channel 401 is connected to the left oil passage 302 through the left annular groove 304, and the right channel is connected to the right oil passage 301 through the right annular groove 303.

[0023] Continue reading Figure 4 and Figure 5 The longitudinal cross-sectional view of the piston-fixed hydraulic cylinder 6 and the partial cross-sectional view of the longitudinal oil passage are shown in the figure, which clearly shows the process of oil entering the cylinder body 200 and driving the valve core 7 to move.

[0024] Continue reading Figure 3 and Figure 4 The left end of the cylinder body 200 is fitted with a transformer connector 203, which is connected to the linear differential transformer 4. A left chamber 305 is formed between the left end of the cylinder body 200 and the transformer connector 203. The right end of the cylinder body 200 is fitted with a push rod 204, which is connected to the valve core 7. A right chamber 306 is formed between the right end of the cylinder body 200 and the push rod 204.

[0025] Continue reading Figure 2 and Figure 6 The reset mechanism includes a valve stem 102 and an elastic element. The valve stem 102 is threaded to the right end of the valve core 7, and the elastic element pushes or pulls the valve stem 102 to the right.

[0026] Further reading Figure 6The reset mechanism also includes a left spring seat 101 and a right spring seat 104 respectively disposed at the left and right ends of the valve stem 102, and a sealing end cap 16 disposed at the right end of the valve body 3. The left spring seat 101 is slidably engaged with the valve stem 102, and the right spring seat 104 is fixedly connected to the valve stem 102. The elastic element is a spring 103 sleeved on the valve stem 102. The spring 103 is connected between the left spring seat 101 and the right spring seat 104. The right spring seat 104 is fixed to the valve stem 102 by a retaining ring 105. The sealing end cap 16 covers the valve stem 102, the spring 103, the left spring seat 101, and the right spring seat 104.

[0027] When the valve core 7 moves to the left or right under high pressure, it drives the right spring seat 104 or the left spring seat 101 to compress the spring 103 respectively. When the system is powered off or the hydraulic pump 1 stops supplying oil, the restoring force of the spring 103 can reset the valve core 7 to the neutral position, realizing the safe power-off reset of the system.

[0028] This invention achieves a structural solution that eliminates the need for an external hydraulic source by directly driving the valve core with an electro-hydraulic pump-driven hydraulic cylinder. It employs a linear differential transformer to detect valve core displacement in real time and implement closed-loop control, improving the accuracy and stability of the valve core's position response. The hydraulic drive provides high thrust and strong resistance to contamination, preventing jamming even when the oil contains impurities. Simultaneously, the reset mechanism ensures that the valve core automatically returns to center when power is off, enhancing system safety and reliability.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electro-hydraulic pump operated direct operated multi-way valve characterized by, The system includes a hydraulic pump (1), a motor (2), a valve body (3), a linear differential transformer (4), a piston-fixed hydraulic cylinder (6), a valve core (7), and a reset mechanism. The valve core (7) is slidably inserted into the valve body (3). The linear differential transformer (4), the piston-fixed hydraulic cylinder (6), the valve core (7), and the reset mechanism are connected sequentially from left to right. The motor (2) is connected to the hydraulic pump (1). The piston-fixed hydraulic cylinder (6) includes a fixed piston (201) and a cylinder body (200) that is slidably sleeved outside the fixed piston (201). The configuration of the electro-hydraulic pump-driven direct-acting multi-way valve is as follows: the motor (2) drives the hydraulic pump (1) to provide high-pressure oil to the piston-fixed hydraulic cylinder (6), so that the cylinder body (200) drives the linear differential transformer (4) and the valve core (7) to move to the left together. The reset mechanism uses elasticity to help the valve core (7) reset to the right. The linear differential transformer (4) is used to obtain the position feedback signal of the valve core (7), thereby realizing the closed-loop control of the position of the valve core (7).

2. The electro-hydraulic pump drive direct operated multi-way valve according to claim 1, characterized in that It also includes a housing (5) fixedly connected to the left side of the valve body (3), and the piston-fixed hydraulic cylinder (6) and the hydraulic pump (1) are respectively inserted into the housing (5).

3. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 2, characterized in that, The piston-fixed hydraulic cylinder (6) also includes a fixed seat (202) fixedly connected to the housing (5). The fixed piston (201) passes through the fixed seat (202) and is fixedly connected to the fixed seat (202). The cylinder body (200) has a hollow groove in the middle, and the fixed seat (202) is located in the hollow groove. The left side of the cylinder body (200) is provided with a left chamber (305) that is sealed and slidingly fitted with the left end of the fixed piston (201). The right side of the cylinder body (200) is provided with a sealing chamber (305) that is sealed with the right end of the fixed piston (201). The right chamber (306) has a sliding fit. The left side of the fixed piston (201) is provided with a left oil passage (302), and the right side of the fixed piston (201) is provided with a right oil passage (301). The fixed seat (202) is provided with a left channel (401) connected to the oil inlet of the hydraulic pump (1) and a right channel connected to the oil outlet of the hydraulic pump (1). The left channel (401), the left oil passage (302) and the left chamber (305) are connected in sequence. The right channel, the right oil passage (301) and the right chamber (306) are connected in sequence.

4. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 3, characterized in that, The fixed piston (201) has a left annular groove (304) and a right annular groove (303) on its outer wall. The left channel (401) is connected to the left oil passage (302) through the left annular groove (304), and the right channel is connected to the right oil passage (301) through the right annular groove (303).

5. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 3, characterized in that, The left end of the cylinder (200) is fitted with a transformer connector (203), which is connected to a linear differential transformer (4), and the left chamber (305) is formed between the left end of the cylinder (200) and the transformer connector (203). The right end of the cylinder (200) is fitted with a push rod (204), which is connected to a valve core (7), and the right chamber (306) is formed between the right end of the cylinder (200) and the push rod (204).

6. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 1, characterized in that, The reset mechanism includes a valve stem (102) and an elastic element. The valve stem (102) is fixedly connected to the right end of the valve core (7). The elastic element pushes or pulls the valve stem (102) to the right.

7. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 6, characterized in that, The reset mechanism also includes a left spring seat (101) and a right spring seat (104) respectively disposed at the left and right ends of the valve stem (102). The left spring seat (101) is slidably engaged with the valve stem (102), and the right spring seat (104) is fixedly connected to the valve stem (102). The elastic element is a spring (103) sleeved on the valve stem (102), and the spring (103) is connected between the left spring seat (101) and the right spring seat (104).

8. The electro-hydraulic pump-driven direct-acting multi-way valve according to claim 7, characterized in that, The reset mechanism also includes a sealing end cap (16) located at the right end of the valve body (3), which covers the valve stem (102), spring (103), left spring seat (101), and right spring seat (104).

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