An electrically controlled double-displacement full hydraulic steering gear

Abstract

The application discloses an electric control double-displacement full-hydraulic steering device and belongs to the technical field of hydraulic transmission and control. The device comprises a valve body, a valve core, a first auxiliary rotating stator and a second auxiliary rotating stator, and further comprises an electric control valve block, an on-off electromagnetic valve and a switching valve. The electric control valve block is installed on the square end face of the valve body, the on-off electromagnetic valve is installed on the side face of the electric control valve block through a plug-in hole, and the switching valve is installed between the two auxiliary rotating stators. According to different working conditions, the electric control is realized, the double-displacement full-hydraulic steering device is operated, the different working condition requirements of full-hydraulic steering of non-road mobile vehicles such as tractors, forklifts and loaders are met, the driving precision and safety are ensured, and the steering efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to a fully hydraulic steering device for non-road mobile vehicles, specifically to an electronically controlled dual-displacement fully hydraulic steering gear, belonging to the field of hydraulic transmission and control technology. Background Technology

[0002] For a long time, once the displacement of the fully hydraulic steering system in off-road mobile vehicles such as tractors, forklifts, and loaders was determined, the number of steering wheel turns was fixed, meaning steering was only possible under one displacement. When driving in road mode, due to good road conditions, a higher number of steering turns and slower steering response are beneficial for driving safety. However, when driving in work mode, due to the need for frequent U-turns, V-shaped and S-shaped movements, the number of steering turns (left and right) increases significantly, resulting in increased workload for the driver.

[0003] To address this issue, a dual-speed hydraulic steering system disclosed in application number 201310714736.0 achieves dual-speed steering by setting a two-position four-way shift valve. However, analysis reveals that: the two-position four-way shift valve lacks a pressure relief oil circuit, causing oil trapping in the rotor and stator when switching between the two gears, resulting in poor steering torque and malfunction; the two-position four-way shift valve is a separate unit connected via oil pipes, resulting in a large structure and inconvenient installation on the main unit; the shift valve is manually controlled, requiring significant effort from the driver and preventing electronic control; the schematic diagram of the oil circuit connecting the shift valve and the steering gear shows a single oil circuit directly connected to the rotor and stator, while in reality, the rotor and stator have seven oil distribution circuits, making oil distribution impossible.

[0004] Applications 201520431962.2 and 201520430414.8 disclose a composite metering hydraulic steering gear and a composite metering full hydraulic steering gear, which are designed to enable manual emergency steering assistance when the engine suddenly stalls, thereby ensuring the driving safety of the vehicle. However, the switching valve is designed to be located behind the two stators, resulting in a longer oil circuit for switching between the two stators and the full hydraulic steering gear, causing significant pressure loss. It is also impossible to switch the full hydraulic steering gear to dual displacement operation electronically according to the driving conditions. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing an electronically controlled dual-displacement fully hydraulic steering system. To achieve the above-mentioned objective, this invention adopts the following technical solution: The present invention discloses an electrically controlled dual-displacement full hydraulic steering gear, comprising a valve body, a valve core, a first auxiliary rotor and a second auxiliary rotor and a second auxiliary rotor, and further comprising an electrically controlled valve block, a switching solenoid valve, and a switching valve; the electrically controlled valve block is mounted on the square end face of the valve body; the switching solenoid valve is mounted on the side of the electrically controlled valve block through an insertion hole; the switching valve is mounted between the two auxiliary rotors and a second auxiliary rotor.

[0006] The present invention is further configured such that the electronically controlled valve block is machined with insertion holes for installing a switching solenoid valve, and four oil ports (P, T, L, R) are machined to communicate with the four oil ports of the steering gear. The electronically controlled valve block is machined with oblique holes that are respectively connected to the two-position three-way control oil circuit of the switching solenoid valve. The valve body is machined with corresponding oil passages to lead the control oil to the switching valve.

[0007] The invention is further configured such that the solenoid valve is a two-position three-way cartridge solenoid valve, which is mounted on the side of the electronically controlled valve block. The solenoid valve and the electronically controlled valve block form three oil circuits: a, b, and c. When the solenoid valve is de-energized, oil enters through the steering gear's P port, and the solenoid valve's oil ports a and b are normally closed, cutting off the control oil circuit to the switching valve. The control oil from the switching valve flows from port b to port c back to port T for pressure relief. When the solenoid valve is energized, the oil port a to port b is connected, while the oil port b to port c is cut off, and the control oil circuit to the switching valve is open.

[0008] The invention is further configured such that the switching valve is installed between the first and second auxiliary rotors / stators. The switching valve is a two-position five-way spool valve. When the solenoid valve is de-energized, the control oil is cut off, and the switching valve core is pressed against the left end of the switching valve body by a spring. The control oil in the switching valve core is depressurized through the solenoid valve oil circuit c, and the switching oil circuit is closed, allowing only the first auxiliary rotor / stator to operate. The high-pressure oil in the seven distribution holes of the second auxiliary rotor / stator is depressurized through the pressure relief oil circuit connected to port T, enabling small-displacement steering. When the solenoid valve is energized, the control oil circuit is connected, and the control oil acts on the left end of the switching valve core, causing the switching valve core to move to the right. The switching oil circuits of the first and second auxiliary rotors / stators are connected, and the two auxiliary rotors / stators work together to achieve large-displacement steering.

[0009] The invention is further configured such that a switch is directly installed on the main unit to control the de-energization and energization of the solenoid valve. The driver can then autonomously switch between the dual-displacement steering modes according to driving and operational conditions.

[0010] The present invention is further configured such that the host upper controller can also control the solenoid valve to be de-energized and energized according to the vehicle speed and steering wheel speed, so as to realize intelligent switching of electronically controlled dual displacement.

[0011] The advantages of this invention are as follows: the electronically controlled valve block equipped with the solenoid valve is installed on the steering gear's square end face, and the switching valve is integrated between the two sets of stators and rotors, facilitating main unit installation; the switching valve adopts a two-position five-way spool valve design with a pressure relief oil circuit, solving the problem of oil trapping in the stator and rotor, making steering torque easier; simultaneously, the two-position three-way solenoid valve enables electronically controlled switching of dual displacement operation, and the electronically controlled switch has a compact structure, is easy to install, and requires little effort to operate; furthermore, the switching valve is designed with seven working oil circuits, enabling normal oil distribution between the two sets of stators and rotors. When the main unit enters road mode, it uses small displacement steering with more steering turns to ensure driving safety; when the main unit enters operating mode, the driver can manually or intelligently switch to a large displacement steering mode, effectively reducing the number of steering turns, improving steering efficiency, and reducing driver fatigue. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the hydraulic system of the electronically controlled dual-displacement full hydraulic steering gear of the present invention; Figure 2 This is a perspective view of the electronically controlled dual-displacement fully hydraulic steering system of the present invention; Figure 3 This is a perspective view of the electrically controlled valve block of the electrically controlled dual-displacement full hydraulic steering gear of the present invention; Figure 4 This is a spatial oblique hole diagram of the electronically controlled valve block of the electronically controlled dual-displacement full hydraulic steering gear of the present invention; Figure 5 This is a perspective view of the valve body of the electronically controlled dual-displacement fully hydraulic steering gear of the present invention; Figure 6 This is the control circuit diagram of the valve body of the electronically controlled dual-displacement fully hydraulic steering gear of the present invention; Figure 7 This is a diagram showing the working position of the switching valve when the electronically controlled dual-displacement full hydraulic steering gear of the present invention fails to operate; Figure 8 This is a diagram showing the working position of the switching valve when the electronically controlled dual-displacement full hydraulic steering gear of the present invention is energized.

[0013] Wherein: 1-valve body, 2-valve core, 3-electric control valve block, 4-switching solenoid valve, 5-second auxiliary rotor / stator, 6-switching valve, 7-first auxiliary rotor / stator, 8-switching solenoid valve socket, 9-space oblique hole for control oil from the electric control valve block to the valve body, 10-space oblique hole for control oil from port P of the electric control valve block, 11-space oblique hole for control oil from port T of the electric control valve block, 12-valve body control oil circuit, 13-switching valve control oil circuit, 14-7 working oil circuits on the left side of the switching valve rotor / stator, 15-7 switching oil circuits of the switching valve, 16-7 working oil circuits on the right side of the switching valve rotor / stator, 17-switching valve body, 18-switching valve core, 19-switching valve spring. Detailed Implementation

[0014] The core of this invention is to provide an electronically controlled dual-displacement fully hydraulic steering system. The specific embodiments and uses of this invention are described in detail below with reference to the accompanying drawings. The specific embodiments described are only illustrative of specific ways of the invention and are not intended to limit the scope of the invention.

[0015] See Figures 1-2 This invention discloses an electrically controlled dual-displacement full hydraulic steering gear, comprising a valve body 1, a valve core 2, a first auxiliary rotor / stator 7 and a second auxiliary rotor / stator 5, an electrically controlled valve block 3, a switching solenoid valve 4, and a switching valve 6. According to the operating conditions, the switching solenoid valve 4 is energized and de-energized, controlling the connection and disconnection of the pilot hydraulic oil. Under the action of the pilot hydraulic oil, the switching valve 6 connects and disconnects the oil circuits of the first auxiliary rotor / stator 7 and the second auxiliary rotor / stator 5.

[0016] See Figures 3-8 The electronically controlled valve block 3 has machined insertion holes for mounting the solenoid valve 4. Four oil ports (P, T, L, R) are machined on the valve block, connecting to the four oil ports of the steering gear. Slanted holes 9, 10, and 11 are machined within the electronically controlled valve block, respectively connecting to the two-position three-way control oil circuit of the solenoid valve 4. The valve body 1 has corresponding oil passages 12 that connect to the oil passage 9 of the electronically controlled valve block 3, leading the control oil to the switching valve oil passage 13. The electronically controlled valve block 3 has countersunk holes and is bolted to the valve body 1, forming a detachable structure.

[0017] See Figure 1 , Figures 4-8 The solenoid valve 4 is a two-position three-way cartridge solenoid valve, installed on the side of the electronically controlled valve block 3. The solenoid valve 4 and the electronically controlled valve block 3 form three oil circuits: a, b, and c. When the solenoid valve 4 is de-energized, oil enters through the steering gear P port, and the solenoid valve is normally closed from port a to port b. The control oil circuit to the switching valve 6 is cut off, and the control oil in the switching valve 6 returns from port b to port c to port T for pressure relief. The working chamber of the switching valve 6 is not trapped with oil, preparing it for the next operation. When the solenoid valve 4 is energized, the oil circuit from port a to port b is connected, while the oil circuit from port b to port c is cut off. The control oil circuit to the switching valve 6 is open, and the control oil enters the working chamber of the switching valve.

[0018] See Figures 7-8The switching valve 6 is installed between the first auxiliary rotor / stator 7 and the second auxiliary rotor / stator 5. The switching valve 6 is a two-position five-way spool valve. When the solenoid valve 4 is de-energized, the control oil is cut off, and the switching valve core 18 is pressed against the left end of the switching valve body by the spring 19. The control oil of the switching valve core 18 is depressurized through the oil circuit c of the solenoid valve 4, and the switching oil circuit is closed. Only the first auxiliary rotor / stator 7 works. The high-pressure oil in the seven oil distribution holes of the second auxiliary rotor / stator 5 is depressurized through the pressure relief oil circuit connected to port T, realizing the small displacement operation of the steering gear. When the solenoid valve 4 is energized, the control oil circuit is connected, and the control oil acts on the left end of the switching valve core 18. The switching valve core 18 moves to the right, and the switching working oil circuit of the first auxiliary rotor / stator 7 and the second auxiliary rotor / stator 5 is opened. The two auxiliary rotors work together, thereby realizing the large displacement steering.

[0019] Switching valve 6 is a two-position five-way spool valve. When the solenoid valve 4 is de-energized, the control oil is cut off, and only the first auxiliary rotor 7 can participate in the operation. The high-pressure oil in the seven distribution holes of the second auxiliary rotor 5 is connected to the T-port for depressurization. In this way, the first auxiliary rotor 7 works as a metering motor under the drive of hydraulic oil, while the second auxiliary rotor 5 is in a depressurized state and is driven to rotate by the rotor 7. If the pressure is not depressurized, it will easily cause the steering gear to be heavy in road mode, affecting the performance. In addition, the high-pressure oil in the seven distribution holes of the second auxiliary rotor 5 connected to the T-port for depressurization also prepares for the next joint operation of the rotor and stator. Otherwise, due to the high pressure trapping oil, the second auxiliary rotor 5 will not be able to work normally in the steering gear operation mode due to the joint operation.

[0020] The main unit's switch directly controls the de-energization and energization of solenoid valve 4. The driver can autonomously switch between dual-displacement steering modes based on driving and operational conditions. When the main unit enters road driving mode at higher speeds, it uses low-displacement steering with more steering rotations to ensure driving safety. When the main unit enters operational mode, the driver can manually switch to high-displacement steering mode to effectively reduce the number of steering rotations, improve steering efficiency, and reduce driver fatigue, achieving driver-controlled dual-displacement steering.

[0021] In this embodiment, the host controller can also receive vehicle speed and steering wheel speed signals to control the solenoid valve 4 to be de-energized and energized, intelligently switching between electronically controlled dual displacements. For example, if the host speed sensor detects a vehicle speed ≤10 km / h (set according to vehicle usage), the controller issues a command, and the steering gear uses the first auxiliary stator 7 and the second auxiliary stator 5 to steer. When the detected vehicle speed >10 km / h, the steering gear uses the first auxiliary stator 7 to steer.

[0022] The working principle of this invention is to achieve two working conditions: the first auxiliary rotor / stator 7 working alone or the first auxiliary rotor / stator 7 and the second auxiliary rotor / stator 5 working together, through the hydraulic pilot control of the electrically controlled solenoid valve 4 and the switching valve 6. The solenoid valve 4 can be electrically controlled in two modes: the first is manual switching based on driver judgment, and the second is intelligent switching based on the vehicle speed and steering wheel speed. The displacement of the first auxiliary rotor / stator 7 and the second auxiliary rotor / stator 5 can be designed according to the OEM's requirements for the number of steering turns. For example, the displacement of the first auxiliary rotor / stator 7 is 100 mL / r, and the displacement of the second auxiliary rotor / stator 5 is 400 mL / r. The 100 mL / r displacement rotor requires 5 steering wheel turns (determined by the OEM's cylinder size), while the 500 mL / r displacement rotor requires 1 steering wheel turn. This dual-displacement combined operation reduces the number of steering turns by 4 compared to a single displacement rotor, increasing steering efficiency by 80%. Simultaneously, the single displacement rotor requires 5 steering turns, ensuring precise and safe steering in road conditions.

[0023] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. An electrically controlled dual-displacement fully hydraulic steering gear, comprising a valve body, a valve core, a first auxiliary rotor and a second auxiliary rotor, characterized in that, It also includes an electrically controlled valve block, a switching solenoid valve, and a switching valve; the electrically controlled valve block is installed on the square end face of the valve body; the switching solenoid valve is installed on the side of the electrically controlled valve block through an insertion hole; the switching valve is installed between the first auxiliary rotor and the second auxiliary rotor.

2. The electronically controlled dual-displacement fully hydraulic steering system according to claim 1, characterized in that, The electronically controlled valve block is machined with insertion holes for installing the solenoid valve, and four oil ports (P, T, L, R) are machined to connect with the four oil ports of the steering gear. The electronically controlled valve block is machined with oblique holes that connect to the two-position three-way control oil circuit of the solenoid valve. The valve body is machined with corresponding oil passages to lead the control oil to the switching valve.

3. The electronically controlled dual-displacement full hydraulic steering system according to claim 1, characterized in that, The solenoid valve is a two-position three-way cartridge solenoid valve, which is installed on the side of the electronically controlled valve block. The solenoid valve and the electronically controlled valve block form three oil circuits: a, b, and c. When the solenoid valve is de-energized, oil enters through the P port of the steering gear, and the oil ports a and b of the solenoid valve are normally closed, cutting off the control oil circuit to the switching valve. The control oil of the switching valve returns from the b port to the c port to the T port for depressurization. When the solenoid valve is energized, the oil ports a and b are connected, while the oil ports b and c are cut off, and the control oil circuit to the switching valve is connected.

4. The electronically controlled dual-displacement fully hydraulic steering system according to claim 1, characterized in that, The switching valve is installed between the first and second auxiliary rotors and stators. The switching valve is a two-position five-way spool valve. When the solenoid valve is de-energized, the control oil is cut off, and the switching valve core is pressed against the left end of the switching valve body by the spring. The control oil of the switching valve core is depressurized through the oil circuit C of the solenoid valve, and the switching oil circuit is closed. Only the first auxiliary rotor and stator works. The high-pressure oil in the seven oil distribution holes of the second auxiliary rotor and stator is depressurized through the pressure relief oil circuit connected to port T, realizing the small displacement operation of the steering gear. When the solenoid valve is energized, the control oil circuit is connected, and the control oil acts on the left end of the switching valve core. The switching valve core moves to the right, and the switching working oil circuit of the first and second auxiliary rotors and stators is connected. The two auxiliary rotors and stators work together to realize the large displacement steering.

5. The electronically controlled dual-displacement fully hydraulic steering system according to claim 1, characterized in that, A switch can be set directly on the main unit to control the solenoid valve to be de-energized and energized. The driver can switch between dual-displacement steering modes independently according to driving and operating conditions.

6. The electronically controlled dual-displacement full hydraulic steering system according to claim 5, characterized in that, The host controller can also control the solenoid valve to be de-energized and energized according to vehicle speed and steering wheel speed, so as to realize intelligent switching between electronically controlled dual displacements.

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