Oil-gas suspension hydraulic circuit capable of being locked in power-off state

Abstract

The invention discloses a hydro-pneumatic suspension hydraulic circuit capable of being locked in a power-off state. Comprising a first two-position two-way normally closed solenoid valve, a second two-position two-way normally closed solenoid valve, an overflow valve, a pressure sensor, a first two-position two-way normally open solenoid valve, a main energy accumulator, a second two-position two-way normally closed solenoid valve, a first auxiliary energy accumulator, a second auxiliary energy accumulator, a hydro-pneumatic spring, a hydraulic control one-way valve, a one-way valve and an electric proportional two-position two-way reversing valve. In the land mode, the vehicle posture adjusting device can achieve variable damping and variable rigidity adjustment according to different road conditions, and the smoothness and maneuverability of the vehicle driving under different road conditions are guaranteed; in the overwater mode, the vehicle posture adjusting device can achieve one-key wheel lifting, take all the wheels back to the top of a wheel cabin, greatly reduce the resistance of the vehicle sailing on the water to increase the navigational speed, and achieve one-key water outlet, all the wheels are put down to the target position and oil is filled into the energy accumulator when the vehicle lands after the overwater running is finished, so that the vehicle suspension recovers the suspension characteristics. And the requirement of smooth login is met.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control and relates to an oil-gas suspension hydraulic circuit capable of being powered off and locked. Background Art

[0002] Modern combat wheeled amphibious armored vehicles have both offensive and defensive capabilities, and their ability to cooperate in combat is extremely outstanding. In order to improve the vehicle's passability, maneuverability, comfort and water speed on complex roads such as off-road roads, muddy roads, tidal flats, and deserts, most of the current wheeled armored vehicles are equipped with oil-gas suspension systems. When driving on land, the vehicle's passability, maneuverability and comfort are greatly improved through vehicle height adjustment, damping adjustment, and stiffness adjustment. When the vehicle is sailing on the water, all wheels are lifted into the wheel wells by one-click cabin retraction, reducing the resistance generated by the wheel part when sailing in the water, increasing the speed of the vehicle sailing in the water, and enabling the armored vehicle to successfully complete the task.

[0003] The oil-gas suspension system used in the current amphibious armored vehicles can generally adjust the height, pitch, roll and wheel lifting and lowering functions of the vehicle. Since the amphibious armored vehicles are used for a longer time on land than on water, the oil-gas suspension system is in the normal state of land mode. Under normal conditions, all solenoid valves can meet the suspension characteristics without power. When the vehicle is traveling on water, the wheels are lifted to reduce the resistance of traveling on water, but the wheel lifting state needs to be maintained, and the channel connecting the rodless cavity and the rod cavity of the oil-gas spring needs to be cut off. Therefore, the solenoid valve needs to be powered for a long time to cut off the oil circuit. When the vehicle stops during driving on water, the wheel lifting state is released, and the wheel needs to be lifted again when it moves again. When the power supply of the oil-gas suspension system fails, the wheel lifting state is released and cannot be lifted again, affecting the vehicle's speed on water. This solution requires the solenoid valve to be powered for a long time to lift the wheel, which continuously consumes vehicle energy. The life of the solenoid valve is greatly reduced when it is powered for a long time, and the system reliability is low. Summary of the invention

[0004] (I) Purpose of the invention

[0005] The purpose of the present invention is to provide a hydraulic circuit of an oil-gas suspension that can be locked by power failure, which is a hydraulic valve block integrating a solenoid valve, a hydraulic control valve, a non-return valve, a throttle valve, an accumulator, and a pressure sensor. The valve block not only meets the conventional oil-gas suspension functions of the oil-gas suspension for vehicle height adjustment, damping adjustment, stiffness adjustment, etc., but also, through the special application mode of the hydraulic control non-return valve, does not need the system to continue to power supply after switching between the land mode and the water mode, that is, it can maintain the wheel lifting state of the oil-gas suspension water mode, thereby reducing the energy consumption of the oil-gas suspension system and improving reliability.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides a gas-oil suspension hydraulic circuit that can be locked by power failure, which includes: a first two-position two-way normally closed solenoid valve 01, a second two-position two-way normally closed solenoid valve 02, a relief valve 03, a pressure sensor 04, a first two-position two-way normally open solenoid valve 05, a main accumulator 06, a second two-position two-way normally closed solenoid valve 07, a first auxiliary accumulator 08, a second auxiliary accumulator 09, a gas-oil spring 10, a hydraulically controlled one-way valve 11, a one-way valve 12, and an electric proportional two-position two-way reversing valve 13; the first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are respectively connected to the rodless chamber oil port and the rod chamber oil port of the gas-oil spring 10 through the internal pipeline of the valve block for locking. The oil inside the oil-gas spring 10; the input end of the relief valve 03 is connected to the oil in the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, and the output end is connected to the return oil pipeline through the internal pipeline of the valve block. When the internal pressure of the oil-gas spring 10 is overloaded and exceeds the design load, the relief valve opens to return the oil, and the oil returns to the oil tank; the pressure sensor 04 is connected to the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, and is used to monitor the oil pressure inside the rodless chamber of the oil-gas spring 10; the first two-position two-position normally open solenoid valve 05 and the second two-position two-position normally open solenoid valve 07 are respectively connected to the first auxiliary accumulator 08, the second auxiliary accumulator 09 and the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, and are used to cut off or open the rodless chamber of the oil-gas spring 10 and the first auxiliary accumulator 08, the connection state of the second auxiliary accumulator 09 is switched; the main accumulator 06, the first auxiliary accumulator 08, and the second auxiliary accumulator 09 are connected to the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, so that the oil-gas spring maintains an elastic state; the oil port of the rodless chamber and the oil port of the rod chamber of the oil-gas spring 10 are connected to the A1 port and the B1 port of the sub-valve block through pipelines, respectively, to support the load between the tire and the vehicle body; the hydraulically controlled one-way valve 11 is connected to the rodless chamber of the oil-gas spring 10 through the input end of the internal pipeline of the valve block and the control oil circuit, and the output end is connected to the rod chamber of the oil-gas spring 10. Under normal vehicle driving conditions, the hydraulically controlled one-way valve 11 is bidirectionally opened. During the extension and retraction process of the oil-gas spring, the oil in the rodless chamber and the rod chamber is exchanged through the hydraulically controlled one-way valve 11. In the wheel lifting state, the oil in the rod chamber of the gas spring 10 is locked to achieve locking of the gas spring in the power-off state; the one-way valve 12 and the electric proportional two-position two-way reversing valve 13 are connected in parallel through the internal pipeline of the valve block and the output end of the hydraulic one-way valve 11 and the rod chamber of the gas spring 10, and the oil in the rodless chamber of the gas spring 10 flows to the rod chamber through the one-way valve 12 and the electric proportional two-position two-way reversing valve 13 at the same time, and the oil in the rod chamber of the gas spring 10 flows to the rodless chamber through the electric proportional two-position two-way reversing valve 13, so that the compression damping of the vehicle suspension is less than the rebound damping. The electric proportional two-position two-way reversing valve 13 controls the opening through the controller to control the interactive flow control of the oil in the rodless chamber and the rod chamber of the gas spring 10, so as to achieve the function of adjustable damping.

[0008] A displacement sensor is provided inside the oil-gas spring 10 to detect the length of the oil-gas spring.

[0009] Among them, when the vehicle is traveling on land and the vehicle posture is raised, the second two-position, two-way normally closed solenoid valve 02 on the valve block is energized to open and filled with oil, and the oil enters the rodless chamber of the oil-gas spring 10 through the second two-position, two-way normally closed solenoid valve 02, and the piston rod moves toward the rod chamber. At this time, the hydraulically controlled one-way valve 11 controls the oil circuit pressure from the rodless chamber pressure oil, and the hydraulically controlled one-way valve 11 opens in the reverse direction, and the rod chamber oil enters the rodless chamber through the electric proportional two-position, two-way reversing valve 13 and the hydraulically controlled one-way valve 11, and the oil-gas spring 10 extends and the vehicle posture is raised. After the vehicle height reaches the target position, the oil supply is stopped, and the second two-position, two-way normally closed solenoid valve 02 loses power to keep the vehicle posture at the current position.

[0010] Among them, when the vehicle is traveling on land and the vehicle posture is lowered, the second two-position, two-way normally closed solenoid valve 02 on the valve block is energized to open, the weight of the vehicle body is pressed down, and the oil-gas spring 10 returns oil to the rodless chamber. At the same time, the oil in the rodless chamber enters the rod chamber through the hydraulically controlled one-way valve 11 and the electric proportional two-position, two-way reversing valve 13, and the piston rod moves toward the rodless chamber, the oil-gas spring contracts, and the vehicle posture is lowered. After the vehicle height reaches the target position, the second two-position, two-way normally closed solenoid valve 02 loses power and no longer returns oil, so that the vehicle posture remains in the current position.

[0011] Among them, when the vehicle is traveling on land, under the condition of variable stiffness adjustment, a circuit is provided at each suspension position, and each circuit is provided with a main accumulator 06, a first auxiliary accumulator 08 and a second auxiliary accumulator 09. By controlling the on-off of the first two-position two-way normally open solenoid valve 05 and the second two-position two-way normally open solenoid valve 07, the first auxiliary accumulator 08 and the second auxiliary accumulator 09 are disconnected from the oil-gas spring 10 individually and simultaneously, so that the oil-gas spring 10 has the states corresponding to the three accumulator volumes, realizing the switching of the three different stiffness modes of soft, medium and hard suspension.

[0012] Among them, when different stiffness modes are switched, the first two-position two-way normally open solenoid valve 05 and the second two-position two-way normally open solenoid valve 07 are both de-energized, and the oil-gas spring 10 is simultaneously connected to a main accumulator 06, a first auxiliary accumulator 08 and a second auxiliary accumulator 09. At this time, the air chamber volume is the largest and the suspension stiffness is the smallest, that is, the suspension is the softest at this time; when the first two-position two-way normally open solenoid valve 05 is energized, the oil-gas spring 10 is simultaneously connected to a main accumulator 06 and a first auxiliary accumulator 08. At this time, the air chamber volume is second largest, and the suspension stiffness increases by one level, that is, the suspension becomes harder at this time; when the first two-position two-way normally open solenoid valve 05 and the second two-position two-way normally open solenoid valve 07 are both energized, the oil-gas spring 10 is only connected to a main accumulator 06. At this time, the air chamber volume is the smallest, the suspension stiffness increases by two levels, and the suspension is in the hardest state.

[0013] Among them, when the vehicle is traveling on land, under variable damping conditions, when the wheel is stimulated by the road surface, the gas spring 10 is compressed, and the oil in the rodless chamber first passes through the hydraulically controlled one-way valve 11, and then enters the rod chamber through the parallel circuit of the electric proportional two-position two-way reversing valve 13 and the one-way valve 12. The oil in the rod chamber only passes through the electric proportional two-position two-way reversing valve 13, and then returns to the rodless chamber through the hydraulically controlled one-way valve 11, and the gas spring 10 returns to the equilibrium position. When the oil in the rodless chamber flows to the rod chamber, the flow area of ​​the parallel one-way valve 12 in the circuit is greater than the flow area of ​​the oil in the rod chamber to the rodless chamber; the vehicle posture adjustment device controls the size of the interactive flow area of ​​the oil in the rodless chamber and the rod chamber of the gas spring 10 by controlling the opening of the electric proportional two-position two-way reversing valve 13 according to the vehicle speed and road conditions, thereby realizing stepless adjustment of the suspension damping.

[0014] Among them, when the vehicle is driving on land, in order to prevent the suspension from breaking down, the oil-gas spring 10 is connected in parallel with the relief valve 03 on the locking circuit. When the wheel is subjected to an impact load exceeding the design, the relief valve 03 opens to drain the pressure oil back to the oil tank.

[0015] Among them, when the vehicle enters the water navigation, under the condition of one-button lifting, the first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are energized to open, and the electric proportional two-position two-way reversing valve 13 is energized to control the signal to give the maximum valve core to be in a closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring 10, and the power oil source enters the rod chamber of the oil-gas spring 10 through the first two-position two-way normally closed solenoid valve 01, the oil-gas spring 10 contracts, and the rodless chamber of the oil-gas spring 10 returns oil, and the oil passes through the second two-position two-way normally closed solenoid valve 01. Valve 02 returns to the oil tank and the wheel is lifted. When the wheel reaches the target position for retracting the cabin, the hydraulic station stops supplying oil, and the first two-position normally closed solenoid valve 01 loses power. After the system detects that the pressure in the rodless chamber of the oil-gas spring 10 is leaked to zero through the pressure sensor 04, the command is ended and all solenoid valves lose power. At this time, the oil pressure in the rodless chamber of the oil-gas spring 10 is zero, that is, the hydraulically controlled one-way valve 11 controls the oil circuit without pressure, and the hydraulically controlled one-way valve 11 cannot be opened in the reverse direction. The oil in the rod chamber of the oil-gas spring 10 is locked in the oil-gas spring, so that the wheel remains in the retracted state.

[0016] When the vehicle enters the water for navigation and one-button water exit is achieved, the first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are electrically opened, and the electric proportional two-position two-way reversing valve 13 receives an electrical control signal to give the maximum valve core to be in a closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring 10, and the power oil source is filled into the rodless chamber of the oil-gas spring 10 through the second two-position two-way normally closed solenoid valve 02, the oil-gas spring is extended, and the rod chamber of the oil-gas spring 10 returns oil, and the oil passes through the first two-position two-way The normally closed solenoid valve 01 returns to the oil tank. At this time, the wheel drops relative to the vehicle body. When the wheel drops relative to the vehicle body to a chassis height that meets the landing requirements, the two-position normally closed solenoid valve 01 loses power, and the oil in the rod chamber of the oil-gas spring 10 is locked, that is, the length of the oil-gas spring is locked. At this time, the rodless chamber of the oil-gas spring 10 continues to be filled with oil to build up pressure. When the pressure meets the requirements to support the vehicle load, the hydraulic station stops supplying oil, all solenoid valves lose power, and the oil-gas spring 10 recovers from rigidity to elasticity. The vehicle suspension recovers its suspension characteristics, allowing the vehicle to meet the landing conditions.

[0017] (III) Beneficial effects

[0018] The oil-gas suspension hydraulic circuit with power-off lock provided by the above technical solution is applied to a chassis adjustment system of an amphibious armored vehicle. The device has two modes: land mode and water mode. In land mode: the vehicle posture adjustment device can adjust variable damping and variable stiffness according to different road conditions to ensure the smoothness and maneuverability of the vehicle under different road conditions; it can adjust the height of the vehicle body and greatly improve the vehicle's passability; in water mode: the vehicle posture adjustment device can realize one-button wheel lifting, retract all wheels to the top of the wheel well, greatly reduce the resistance of the vehicle when sailing on the water and increase the speed. When landing on the water, it can realize one-button exit from the water, lower all wheels to the target position, flush oil to the accumulator, restore the suspension characteristics of the vehicle suspension, and meet the needs of smooth landing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The hydraulic principle diagram of the oil-gas suspension hydraulic circuit that can be powered off and locked according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0021] Reference Figure 1As shown, the oil-gas suspension hydraulic circuit that can be locked by power failure in this embodiment includes: a first two-position two-way normally closed solenoid valve 01, a second two-position two-way normally closed solenoid valve 02, a relief valve 03, a pressure sensor 04, a first two-position two-way normally open solenoid valve 05, a main accumulator 06, a second two-position two-way normally closed solenoid valve 07, a first auxiliary accumulator 08, a second auxiliary accumulator 09, an oil-gas spring 10, a hydraulically controlled one-way valve 11, a one-way valve 12, and an electric proportional two-position two-way reversing valve 13; the first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are connected to the oil port of the rodless cavity and the oil port of the rod cavity of the oil-gas spring 10 through the internal pipeline of the valve block, respectively, for locking the oil in the oil-gas spring 10; the input end of the relief valve 03 is connected to the oil port of the rodless cavity of the oil-gas spring 10 through the internal pipeline of the valve block The internal pipeline is connected to the rodless chamber oil of the oil-gas spring 10, and the output end is connected to the return oil pipeline through the internal pipeline of the valve block. When the internal pressure of the oil-gas spring 10 is overloaded and exceeds the design load, the overflow valve opens to return oil, and the oil returns to the oil tank to prevent the suspension from breaking down due to excessive pressure and causing irreversible damage; the pressure sensor 04 is connected to the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, and is used to monitor the oil pressure inside the rodless chamber of the oil-gas spring 10; the first two-position two-position normally open solenoid valve 05 and the second two-position two-position normally open solenoid valve 07 are respectively connected to the first auxiliary accumulator 08, the second auxiliary accumulator 09 and the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, and are used to cut off or open the connection between the rodless chamber of the oil-gas spring 10 and the first auxiliary accumulator 08 and the second auxiliary accumulator 09. state switching; the main accumulator 06, the first auxiliary accumulator 08, and the second auxiliary accumulator 09 are connected to the rodless chamber of the oil-gas spring 10 through the internal pipeline of the valve block, so that the oil-gas spring maintains an elastic state; the oil port of the rodless chamber and the oil port of the rod chamber of the oil-gas spring 10 are respectively connected to the sub-valve blocks A1 and B1 through pipelines to support the load between the tire and the vehicle body. At the same time, a displacement sensor is provided inside the oil-gas spring 10 for the system to detect the length of the oil-gas spring. The hydraulically controlled one-way valve 11 is connected to the rodless chamber of the oil-gas spring 10 through the input end of the internal pipeline of the valve block and the control oil circuit, and the output end is connected to the rod chamber of the oil-gas spring 10. Under normal vehicle driving conditions, the hydraulically controlled one-way valve 11 is bidirectionally opened, and the oil in the rodless chamber and the rod chamber during the extension and retraction of the oil-gas spring can be realized through the hydraulically controlled one-way valve 11 The oil-liquid interaction locks the oil in the rod chamber of the oil-gas spring 10 in the wheel-lifting state, thereby realizing the locking of the oil-gas spring in the power-off state; the one-way valve 12 and the electric proportional two-position two-way reversing valve 13 are connected in parallel through the internal pipeline of the valve block and the output end of the hydraulically controlled one-way valve 11 and the rod chamber of the oil-gas spring 10. The oil in the rodless chamber of the oil-gas spring 10 can flow to the rod chamber through the one-way valve 12 and the electric proportional two-position two-way reversing valve 13 at the same time, and the oil in the rod chamber of the oil-gas spring 10 can only flow to the rodless chamber through the electric proportional two-position two-way reversing valve 13, thereby realizing the function that the compression damping of the vehicle suspension is less than the rebound damping. The electric proportional two-position two-way reversing valve 13 can control the opening through the controller, control the interactive flow control of the oil in the rodless chamber and the rod chamber of the oil-gas spring 10, and realize the function of adjustable damping.

[0022] When the vehicle is driving on land:

[0023] Vehicle posture rises: the second two-position, two-way normally closed solenoid valve 02 on the valve block is energized and opened, and port A is filled with oil. The oil enters the rodless chamber of the oil-gas spring 10 through the second two-position, two-way normally closed solenoid valve 02, and the piston rod moves toward the rod chamber. At this time, the hydraulically controlled one-way valve 11 controls the oil circuit pressure from the rodless chamber pressure oil. The hydraulically controlled one-way valve 11 opens in the reverse direction, and the oil in the rod chamber enters the rodless chamber through the electric proportional two-position, two-way reversing valve 13 and the hydraulically controlled one-way valve 11, and the oil-gas spring 10 extends, and the vehicle posture rises. After the vehicle height reaches the target position, the oil supply from port P stops and the second two-position, two-way normally closed solenoid valve 02 loses power, so that the vehicle posture remains in the current position.

[0024] Vehicle posture lowering: the second two-position, two-way normally closed solenoid valve 02 on the valve block is energized and opened, the weight of the vehicle body is pressed down, and the oil-gas spring 10 returns oil from the rodless chamber through port A. At the same time, the oil in the rodless chamber passes through the hydraulically controlled one-way valve 11 and the electric proportional two-position, two-way directional reversing valve 13 and enters the rod chamber. The piston rod moves toward the rodless chamber, the oil-gas spring contracts, and the vehicle posture is lowered. After the vehicle height reaches the target position, the second two-position, two-way normally closed solenoid valve 02 loses power, and port A no longer returns oil, so that the vehicle posture remains in the current position.

[0025] Variable stiffness: The necessity of variable suspension stiffness is to increase dynamic capacity, maintain smoothness, adapt to different loads, and reduce vibration and impact, thereby improving the vehicle's driving performance and ride comfort. The vehicle posture adjustment device can switch the suspension stiffness to three levels according to the vehicle's speed, load conditions and road conditions during driving.

[0026] The relationship between the stiffness of the hydro-pneumatic suspension and the volume of the accumulator is as shown in the following formula (5). It can be seen that the suspension stiffness is inversely proportional to the initial volume of the accumulator, that is, the larger the initial volume of the accumulator, the smaller the suspension stiffness. A single loop is set at each suspension position, and a main accumulator 06, a first auxiliary accumulator 08, and a second auxiliary accumulator 09 are provided on each loop. By controlling the on / off of the first two-position two-way normally open solenoid valve 05 and the second two-position two-way normally open solenoid valve 07, the first auxiliary accumulator 08 and the second auxiliary accumulator 09 are separately disconnected and simultaneously disconnected from the hydro-pneumatic spring 10, enabling the hydro-pneumatic spring 10 to have states corresponding to three accumulator volumes, thereby realizing the switching of three different stiffness modes of the suspension, namely soft, medium, and hard. That is, when neither the first two-position two-way normally open solenoid valve 05 nor the second two-position two-way normally open solenoid valve 07 is energized, the hydro-pneumatic spring 10 is simultaneously connected to a main accumulator 06, a first auxiliary accumulator 08, and a second auxiliary accumulator 09. At this time, the air chamber volume is the largest and the suspension stiffness is the smallest, that is, the suspension is the softest at this time; when the first two-position two-way normally open solenoid valve 05 is energized, the hydro-pneumatic spring 10 is simultaneously connected to a main accumulator 06 and a first auxiliary accumulator 08. At this time, the air chamber volume is the second largest and the suspension stiffness increases by one level, that is, the suspension becomes harder at this time; when both the first two-position two-way normally open solenoid valve 05 and the second two-position two-way normally open solenoid valve 07 are energized, the hydro-pneumatic spring 10 is only connected to a main accumulator 06. At this time, the air chamber volume is the smallest and the suspension stiffness increases by two levels, and the suspension is in the hardest state.

[0027] Equivalent stiffness k of the hydro-pneumatic suspension s = m u g / Δx (1)

[0028] In the formula, m u is the mass of the suspension single-wheel spring, and Δx is the compression amount of the hydro-pneumatic spring.

[0029] m u g = P1 * S (2)

[0030] In the formula, P1 is the internal pressure of the hydro-pneumatic spring, that is, the internal pressure of the accumulator, and S is the cross-sectional area of the piston rod of the hydro-pneumatic spring.

[0031] According to the gas state equation:

[0032] P0V0 = P1V1 (3)

[0033] In the formula, P0 is the inflation pressure of the accumulator, V0 is the volume of the accumulator, that is, the initial gas volume, P1 is the pressure of the accumulator when the suspension bears the vehicle weight in balance, and V1 is the gas volume of the accumulator after absorbing the oil volume of the compressed part of the hydro-pneumatic spring when the suspension bears the vehicle weight in balance.

[0034] V0 - V1 = S * Δx (4)

[0035] That is, the equivalent stiffness of the hydro-pneumatic suspension is obtained:

[0036]

[0037] Variable damping: Variable damping of the suspension is of great significance for improving the comfort, safety and comfort of the vehicle. The vehicle posture adjustment device can adjust the suspension damping steplessly according to the driving speed during the driving process of the vehicle. During the driving process of the vehicle, the suspension will continue to expand or contract. At this time, the oil-gas spring 10 will continue to expand and contract. The oil in the rodless chamber and the rod chamber of the oil-gas spring 10 will continue to interact through the damping adjustable circuit. When the wheel is stimulated by the road surface, the oil-gas spring 10 is compressed. The oil in the rodless chamber first passes through the hydraulically controlled one-way valve 11, and then enters the rod chamber through the parallel circuit of the electric proportional two-position two-way reversing valve 13 and the one-way valve 12. The oil in the rod chamber only passes through the electric proportional two-position two-way reversing valve 13, and then returns to the rodless chamber through the hydraulically controlled one-way valve 11. The oil-gas spring 10 returns to the equilibrium position. When the oil in the rodless chamber flows to the rod chamber, the flow area of ​​the one-way valve 12 in parallel on the circuit is greater than the flow area of ​​the oil in the rod chamber to the rodless chamber. The suspension compression damping is small, so that the elastic effect of the elastic element can be fully utilized to mitigate the impact. The rebound damping is large to achieve the effect of rapid shock absorption. The vehicle posture adjustment device can control the size of the oil flow area of ​​the rodless chamber and the rod chamber of the oil-gas spring 10 by controlling the opening of the electric proportional two-position two-way reversing valve 13 according to the vehicle speed and road conditions, thereby realizing stepless adjustment of the suspension damping.

[0038] Prevent suspension breakdown: According to the hydraulic principle, the overflow valve 03 is connected in parallel to the locking circuit of the gas spring 10. When the wheel is subjected to an impact load exceeding the design, the overflow valve 03 opens to drain the pressurized oil back to the oil tank, avoiding damage to the vehicle body structure caused by excessive impact force.

[0039] When the vehicle enters the water, it floats on the water, and the vehicle posture adjustment device can switch to the water mode. At this time, the commands in the land mode are invalid:

[0040] One-touch wheel lifting: The first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are energized to open, and the electric proportional two-position two-way reversing valve 13 is energized to control the signal to the maximum valve core to be in a closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring 10, and the power oil source enters the rod chamber of the oil-gas spring 10 through the first two-position two-way normally closed solenoid valve 01, the oil-gas spring 10 contracts, and the oil returns to the rodless chamber of the oil-gas spring 10, and the oil returns to the oil tank through the second two-position two-way normally closed solenoid valve 02. The wheel is lifted, and when the wheel reaches the target position for retracting, the hydraulic station stops supplying oil, and the first two-position normally closed solenoid valve 01 loses power. After the system detects that the pressure in the rodless chamber of the oil-gas spring 10 is leaked to zero through the pressure sensor 04, the command is ended, and all solenoids lose power. At this time, the oil pressure in the rodless chamber of the oil-gas spring 10 is zero, that is, the hydraulically controlled one-way valve 11 controls the oil circuit without pressure, and the hydraulically controlled one-way valve 11 cannot be opened in the reverse direction. The oil in the rod chamber of the oil-gas spring 10 is locked in the oil-gas spring, so that the wheel remains in the retracted state.

[0041] One-touch water discharge: the first two-position two-way normally closed solenoid valve 01 and the second two-position two-way normally closed solenoid valve 02 are opened, and the electric proportional two-position two-way reversing valve 13 receives an electric control signal to give the maximum valve core to the closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring 10, and the power oil source is filled into the rodless chamber of the oil-gas spring 10 through the second two-position two-way normally closed solenoid valve 02. The oil-gas spring extends, and the rod chamber of the oil-gas spring 10 returns oil, and the oil returns to the oil tank through the first two-position two-way normally closed solenoid valve 01. At this time, the wheel drops relative to the vehicle body. When the wheel drops relative to the vehicle body to a chassis height that meets the landing requirements, the two-position two-way normally closed solenoid valve 01 loses power, and the oil in the rod chamber of the oil-gas spring 10 is locked, that is, the length of the oil-gas spring is locked. At this time, the rodless chamber of the oil-gas spring 10 continues to be filled with oil to build up pressure. When the pressure meets the requirements to support the vehicle load, the hydraulic station stops supplying oil, all solenoid valves lose power, and the oil-gas spring 10 recovers from rigidity to elasticity, and the vehicle suspension recovers its suspension characteristics, so that the vehicle meets the landing conditions.

[0042] It can be seen from the above technical solution that the present invention has the following significant features:

[0043] (1) Power-off locking function for wheel lifting and retracting: When lifting the wheel, the oil-gas spring needs to be retracted. It can be seen from the sub-valve block in the hydraulic principle diagram that the rod chamber needs to be filled with oil and the rodless chamber needs to return oil. At this time, the passage between the rodless chamber and the rod chamber needs to be disconnected, otherwise the oil-gas spring will become longer, and the solenoid valve in the connecting circuit will be disconnected. The rod chamber will be filled with oil and the rodless chamber will return oil. When it is retracted to the full position, the pressure relief pressure of the rodless chamber is 0. At this time, the hydraulic control one-way valve is blocked in the reverse direction. When the solenoid valve is powered off, the rod chamber still cannot go to the rodless chamber, so the wheel lifting state can be maintained.

[0044] (2) Adjustable damping: Variable damping of the suspension is of great significance to improving the comfort, safety and ride quality of the vehicle. The necessity of variable stiffness of the suspension is to increase dynamic capacity, maintain smoothness, adapt to different loads, and reduce vibration and impact, thereby improving the vehicle's driving performance and ride comfort.

[0045] (3) Variable stiffness: The necessity of variable suspension stiffness is to increase dynamic capacity, maintain smoothness, adapt to different loads, and reduce vibration and impact, thereby improving the vehicle's driving performance and ride comfort.

[0046] (4) Prevent suspension breakdown: Through the principle of the valve block, it can be seen that the oil-gas spring circuit is connected in parallel with the overflow valve. When the wheel is subjected to an impact load exceeding the design, the overflow valve opens to release the pressurized oil back to the oil tank, avoiding damage to the vehicle body structure caused by excessive impact force.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A hydraulic circuit of an oil-gas suspension capable of being locked by power failure, characterized in that: include: A first two-position two-way normally closed solenoid valve (01), a second two-position two-way normally closed solenoid valve (02), a relief valve (03), a pressure sensor (04), a first two-position two-way normally open solenoid valve (05), a main accumulator (06), a second two-position two-way normally closed solenoid valve (07), a first auxiliary accumulator (08), a second auxiliary accumulator (09), an oil-gas spring (10), a hydraulically controlled one-way valve (11), a one-way valve (12), and an electric proportional two-position two-way directional valve (13); the first two-position two-way normally closed solenoid valve (01) and the second two-position two-way normally closed solenoid valve (02) are respectively connected to the rodless chamber oil port and the rod chamber oil port of the oil-gas spring (10) through the internal pipeline of the valve block, so as to lock the internal oil of the oil-gas spring (10); the input end of the relief valve (03) is connected to the oil port of the rodless chamber and the rod chamber of the oil-gas spring (10) through the internal pipeline of the valve block, so as to lock the internal oil of the oil-gas spring (10); the input end of the relief valve (03) is connected to the oil port of the rodless chamber and the rod chamber of the oil-gas spring (10). The oil in the rodless chamber of the gas spring (10) is connected through the internal pipeline of the valve block, and the output end is connected with the oil return pipeline through the internal pipeline of the valve block. When the internal pressure of the gas spring (10) is overloaded and exceeds the design load, the overflow valve opens to return the oil, and the oil returns to the oil tank; the pressure sensor (04) is connected with the rodless chamber of the gas spring (10) through the internal pipeline of the valve block, and is used to monitor the oil pressure inside the rodless chamber of the gas spring (10); the first two-position two-position normally open solenoid valve (05) and the second two-position two-position normally open solenoid valve (07) are respectively connected with the first auxiliary accumulator (08), the second auxiliary accumulator (09) and the rodless chamber of the gas spring (10) through the internal pipeline of the valve block, and are used to cut off or open the rodless chamber of the gas spring (10) and the first auxiliary accumulator (08), the second auxiliary accumulator (09) ) connection state switching; the main accumulator (06), the first auxiliary accumulator (08), and the second auxiliary accumulator (09) are connected to the rodless chamber of the gas spring (10) through the internal pipeline of the valve block, so that the gas spring maintains an elastic state; the oil port of the rodless chamber and the oil port of the rod chamber of the gas spring (10) are respectively connected to the A1 port and the B1 port of the sub-valve block through pipelines, which are used to support the load between the tire and the vehicle body; the hydraulically controlled one-way valve (11) is connected to the rodless chamber of the gas spring (10) through the input end of the internal pipeline of the valve block and the control oil circuit, and the output end is connected to the rod chamber of the gas spring (10). Under normal vehicle driving conditions, the hydraulically controlled one-way valve (11) is bidirectionally opened. During the extension and retraction process of the gas spring, the oil in the rodless chamber and the rod chamber is exchanged through the hydraulically controlled one-way valve (11), and the gas spring is locked in the wheel lifting state. The oil in the rod chamber of the gas spring (10) is used to lock the gas spring in the power-off state; the one-way valve (12) and the electric proportional two-position two-way reversing valve (13) are connected in parallel through the internal pipeline of the valve block and are connected to the output end of the hydraulic one-way valve (11) and the rod chamber of the gas spring (10); the oil in the rodless chamber of the gas spring (10) flows to the rod chamber through the one-way valve (12) and the electric proportional two-position two-way reversing valve (13) at the same time; the oil in the rod chamber of the gas spring (10) flows to the rodless chamber through the electric proportional two-position two-way reversing valve (13), realizing the function that the compression damping of the vehicle suspension is less than the rebound damping; the electric proportional two-position two-way reversing valve (13) controls the opening through the controller to control the interactive flow control of the oil in the rodless chamber and the rod chamber of the gas spring (10), realizing the function of adjustable damping.

2. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 1, characterized in that: A displacement sensor is arranged inside the oil-gas spring (10) for systematically detecting the length of the oil-gas spring.

3. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 2, characterized in that: When the vehicle is traveling on land and the vehicle posture is raised, the second two-position two-way normally closed solenoid valve (02) on the valve block is energized to open and fill with oil. The oil enters the rodless chamber of the oil-gas spring (10) through the second two-position two-way normally closed solenoid valve (02), and the piston rod moves toward the rod chamber. At this time, the hydraulically controlled one-way valve (11) controls the oil circuit pressure from the rodless chamber pressure oil. The hydraulically controlled one-way valve (11) opens in the reverse direction, and the rod chamber oil enters the rodless chamber through the electric proportional two-position two-way reversing valve (13) and the hydraulically controlled one-way valve (11). The oil-gas spring (10) extends and the vehicle posture is raised. When the vehicle height reaches the target position, the oil supply is stopped and the second two-position two-way normally closed solenoid valve (02) loses power, so that the vehicle posture remains at the current position.

4. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 3, characterized in that: When the vehicle is traveling on land and the vehicle posture is lowered, the second two-position two-way normally closed solenoid valve (02) on the valve block is energized to open, the vehicle body is pressed downward by its own weight, and the oil in the rodless chamber of the oil-gas spring (10) returns oil. At the same time, the oil in the rodless chamber enters the rod chamber through the hydraulically controlled one-way valve (11) and the electric proportional two-position two-way reversing valve (13), and the piston rod moves toward the rodless chamber, the oil-gas spring contracts, and the vehicle posture is lowered. After the vehicle height reaches the target position, the second two-position two-way normally closed solenoid valve (02) loses power and no longer returns oil, so that the vehicle posture remains at the current position.

5. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 4, characterized in that: When the vehicle is traveling on land, under variable stiffness adjustment, a circuit is provided at each suspension position, and each circuit is provided with a main accumulator (06), a first auxiliary accumulator (08) and a second auxiliary accumulator (09). By controlling the on-off of a first two-position two-way normally open solenoid valve (05) and a second two-position two-way normally open solenoid valve (07), the first auxiliary accumulator (08) and the second auxiliary accumulator (09) are disconnected from the oil-gas spring (10) individually or simultaneously, so that the oil-gas spring (10) has states corresponding to the three accumulator volumes, and the three different stiffness modes of soft, medium and hard suspension are switched.

6. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 5, characterized in that: When switching between different stiffness modes, the first two normally open solenoid valves (05) and the second two normally open solenoid valves (07) are both de-energized, and the oil-gas spring (10) is simultaneously connected to a main accumulator (06), a first auxiliary accumulator (08) and a second auxiliary accumulator (09). At this time, the air chamber volume is the largest and the suspension stiffness is the smallest, that is, the suspension is the softest; when the first two normally open solenoid valves (05) are energized, the oil-gas spring (10) is simultaneously connected to a main accumulator (06) and a first auxiliary accumulator (08). At this time, the air chamber volume is the second largest and the suspension stiffness increases by one level, that is, the suspension becomes stiffer; when the first two normally open solenoid valves (05) and the second two normally open solenoid valves (07) are both energized, the oil-gas spring (10) is only connected to a main accumulator (06). At this time, the air chamber volume is the smallest and the suspension stiffness increases by two levels, and the suspension is in the stiffest state.

7. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 6, characterized in that: When the vehicle is traveling on land, under variable damping conditions, when the wheel is stimulated by the road surface, the gas spring (10) is compressed, and the oil in the rodless chamber first passes through the hydraulically controlled one-way valve (11), and then enters the rod chamber through the parallel circuit of the electric proportional two-position two-way reversing valve (13) and the one-way valve (12). The oil in the rod chamber only passes through the electric proportional two-position two-way reversing valve (13), and then returns to the rodless chamber through the hydraulically controlled one-way valve (11). The gas spring (10) returns to the equilibrium position. When the oil in the rodless chamber flows to the rod chamber, the flow area of ​​the parallel one-way valve (12) on the circuit is greater than the flow area of ​​the oil in the rod chamber to the rodless chamber. The vehicle posture adjustment device controls the size of the interactive flow area of ​​the oil in the rodless chamber and the rod chamber of the gas spring (10) by controlling the opening of the electric proportional two-position two-way reversing valve (13) according to the vehicle speed and road conditions, thereby realizing stepless adjustment of the suspension damping.

8. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 7, characterized in that: When the vehicle is traveling on land, in order to prevent suspension breakdown, a relief valve (03) is connected in parallel to the oil-gas spring (10) locking circuit. When the wheel is subjected to an impact load exceeding the designed load, the relief valve (03) opens to drain the pressure oil back to the oil tank.

9. The oil-gas suspension hydraulic circuit capable of power-off locking as claimed in claim 8, characterized in that: When the vehicle enters the water, in the case of one-touch wheel lifting, the first two-position two-way normally closed solenoid valve (01) and the second two-position two-way normally closed solenoid valve (02) are energized to open, and the electric proportional two-position two-way reversing valve (13) is energized to control the signal to give the maximum valve core to be in a closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring (10), and the power oil source enters the rod chamber of the oil-gas spring (10) through the first two-position two-way normally closed solenoid valve (01), the oil-gas spring (10) contracts, and the rodless chamber of the oil-gas spring (10) returns oil, and the oil passes through the second two-position two-way normally closed solenoid valve ( 02) returns to the oil tank, the wheel is lifted, and when the wheel reaches the target position for retracting, the hydraulic station stops supplying oil, the first two normally closed solenoid valves (01) lose power, and after the system detects that the pressure in the rodless chamber of the oil-gas spring (10) is leaked to zero through the pressure sensor (04), the command is terminated, and all solenoid valves lose power. At this time, the oil pressure in the rodless chamber of the oil-gas spring (10) is zero, that is, the hydraulically controlled one-way valve (11) controls the oil circuit without pressure, and the hydraulically controlled one-way valve (11) cannot be opened in the reverse direction. The oil in the rod chamber of the oil-gas spring (10) is locked in the oil-gas spring, so that the wheel remains in the retracted state.

10. The oil-gas suspension hydraulic circuit capable of power-off locking according to claim 9, characterized in that: When the vehicle enters the water for navigation, in the case of one-key water exit, the first two-position two-way normally closed solenoid valve (01) and the second two-position two-way normally closed solenoid valve (02) are electrically opened, and the electric proportional two-position two-way reversing valve (13) receives an electric control signal to give the maximum valve core to a closed state, disconnecting the interconnection channel between the rodless chamber and the rod chamber of the oil-gas spring (10), and the power oil source is filled into the rodless chamber of the oil-gas spring (10) through the second two-position two-way normally closed solenoid valve (02), the oil-gas spring is extended, and the rod chamber of the oil-gas spring (10) returns oil, and the oil passes through the first two-position two-way The normally closed solenoid valve (01) returns to the oil tank. At this time, the wheel drops relative to the vehicle body. When the wheel drops relative to the vehicle body to a chassis height that satisfies landing, the two normally closed solenoid valves (01) lose power, and the oil in the rod chamber of the oil-gas spring (10) is locked, that is, the length of the oil-gas spring is locked. At this time, the rodless chamber of the oil-gas spring (10) continues to be filled with oil to build up pressure. When the pressure is sufficient to support the vehicle load, the hydraulic station stops supplying oil, all solenoid valves lose power, and the oil-gas spring (10) recovers from rigidity to elasticity. The vehicle suspension recovers its suspension characteristics, making the vehicle ready for landing.

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