Control drive system for a fuzzy output signal

Abstract

The utility model relates to vehicle hydraulic transmission and control technical field, concretely relates to the control drive system of fuzzy output signal, be applied to the differentiation control of front and rear wheel drive motor in the process of large -scale vehicle turning, the system includes pump control system, flow pressure control system, wheel system and oil return control system, the pump control system includes main pump, oil pump control cylinder, flow pressure control valve and throttle valve, the swash plate on main pump links with the piston rod on oil pump control cylinder, and oil pump control cylinder has A mouth and B mouth, flow pressure control valve has C mouth, D mouth, P mouth and the Z mouth and spring end K mouth located on both sides, the utility model discloses, through load response feedback oil circuit (LS) feedback mechanism, realize the adaptive flow distribution of front and rear wheel drive motor, solve the problem that the front and rear wheel speed does not match in the process of large -scale vehicle turning, and the steering accuracy, stability and safety are improved.

Description

Technical Field

[0001] This utility model relates to the field of vehicle hydraulic transmission and control technology, and in particular to a control drive system with fuzzy output signals. Background Technology

[0002] During the operation of large vehicles, especially when turning, the front and rear wheels have different turning radii, thus requiring them to operate at different speeds to achieve smooth and precise steering. However, most existing large vehicles employ a front-wheel steering and rear-wheel passive following structure, meaning the rear wheels cannot actively adjust their speed according to the actual steering trajectory, leading to the following problems: 1. The rear wheels slip laterally during cornering, causing severe tire wear; Second, uneven force on the wheel side results in excessive steering torque, affecting the vehicle's handling stability. Third, at high speeds or sharp turns, the vehicle is prone to rollover accidents due to a shift in the center of gravity.

[0003] Currently, there is no mature system for intelligent coordinated control of the steering speed of the front and rear wheels of large vehicles. Traditional hydraulic drive systems lack the ability to adapt to changes in load and cannot achieve dynamic flow distribution between the front and rear drive motors.

[0004] Therefore, there is an urgent need to develop a control drive system that can automatically adjust the front and rear wheel drive flow according to the vehicle's steering state in order to improve the steering performance, safety and economy of large vehicles. To this end, we propose a control drive system with fuzzy output signals, which can effectively solve the above problems. Utility Model Content

[0005] In view of this, the purpose of this utility model is to propose a control drive system with fuzzy output signals to solve the problem of mismatch between the front and rear wheel speeds during the turning process of large vehicles, thereby improving steering accuracy, stability and safety.

[0006] Based on the above objectives, this utility model provides a control and drive system for fuzzy output signals, applied to the differentiated control of the front and rear wheel drive motors during the turning process of large vehicles. The system includes a pump control system, a flow and pressure control system, a wheel drive system, and a return oil control system. The pump control system includes a main pump, a pump control cylinder, a flow and pressure control valve, and a throttle valve. The swashplate on the main pump is connected to the piston rod on the pump control cylinder, which has ports A and B. The flow and pressure control valve has ports C, D, and P, as well as ports Z and a spring end K on both sides. Port A of the pump control cylinder is connected to ports C and Z of the flow and pressure control valve, port B is connected to port P of the flow and pressure control valve, and port D of the flow and pressure control valve is connected to the return oil control system. The wheel drive system includes at least two drive motors, namely drive motor one and drive motor two. The flow and pressure control system includes an adjustable flow valve one, an adjustable flow valve two, a two-position two-way throttle valve, and a load sensor. The feedback oil circuit includes a two-position two-way throttle valve, comprising a first two-position two-way throttle valve and a second two-position two-way throttle valve. The first two-position two-way throttle valve has ports E, F, and H, and a spring-loaded port G. The second two-position two-way throttle valve has ports I, L, and H, and a spring-loaded port J. The inlet of the first adjustable flow valve is connected to the outlet of the main pump, and the outlet of the first adjustable flow valve is connected to ports E and H of the first two-position two-way throttle valve. The F port of the first two-position two-way throttle valve is connected to the inlet of the drive motor. The oil inlet of the second pump is connected to the oil outlet of the main pump, and the oil outlet of the second adjustable flow valve is connected to the L and N ports of the second two-position two-way throttle valve. The I port of the second two-position two-way throttle valve is connected to the oil inlet of the second drive motor. The load sensing feedback oil circuit is connected to the spring end K port of the flow and pressure control valve. The system collects the highest load pressure signal of each drive motor in real time through the load sensing feedback oil circuit, feeds it back to the flow and pressure control valve, and adjusts the displacement of the main pump so that the outlet pressure of the main pump follows the dynamic change of the highest load pressure.

[0007] Preferably, the return oil control system includes a hydraulic oil tank, a return oil filter element, and a pressure signal switch. The oil inlet of the return oil filter element is connected to the D port of the flow and pressure control valve through a throttle valve, the oil outlet of the return oil filter element is connected to the hydraulic oil tank, and the pressure signal switch is connected between the oil inlet and the oil outlet of the return oil filter element.

[0008] Preferably, the oil return control system further includes a back pressure check valve, the oil inlet of which is connected to the oil inlet of the oil return filter element, and the oil outlet of which is connected to the oil outlet of the oil return filter element.

[0009] Preferably, the load sensing feedback oil circuit includes a first check valve and a second check valve. The inlet of the first check valve is connected to the F port of the second-position two-way throttle valve, and the outlet of the first check valve is connected to the spring end G port of the second-position two-way throttle valve, the outlet of the adjustable flow valve, and the spring end K port of the flow and pressure control valve. The inlet of the second check valve is connected to the I port of the second-position two-way throttle valve, and the outlet of the second check valve is connected to the spring end J port of the second-position two-way throttle valve, the outlet of the adjustable flow valve, and the spring end K port of the flow and pressure control valve.

[0010] Preferably, the load sensing feedback oil circuit collects the highest load pressure in each branch and synchronously leads this highest load pressure to the spring end G port of the first two-position two-way throttle valve, the spring end J port of the second two-position two-way throttle valve, and the spring end K port of the flow and pressure control valve. The flow and pressure control valve receives the pressure signal from the load sensing feedback oil circuit and adjusts the displacement of the main pump so that the outlet pressure of the main pump dynamically changes with the highest load pressure. When a certain drive motor branch is the maximum load side, its corresponding two-position two-way throttle valve automatically closes because the pressure difference across the valve port is the smallest, forcing the main pump to increase the outlet pressure to ensure the flow supply on that side. The two-position two-way throttle valves on the non-maximum load side close to a smaller degree, realizing an adaptive "fuzzy" distribution of the flow of the front and rear wheel drive motors.

[0011] Preferably, it also includes a safety unloading protection valve, which has an R port, an S port and a U port. The R port of the safety unloading protection valve is connected to the oil outlet of the one-way valve, and the S port and U port of the safety unloading protection valve are respectively connected to the oil outlet of the hydraulic oil tank and the main pump.

[0012] The beneficial effects of this utility model are as follows: Intelligent coordinated control of front and rear wheel steering speeds: This system uses a load-sensing feedback (LS) circuit to collect the highest load pressure in each execution branch in real time and synchronously feeds it back to the spring end of each two-position two-way throttle valve. Under this mechanism, the two-position two-way throttle valve on the high-load side automatically closes, forcing the main pump to increase its outlet pressure and prioritizing the flow supply to the high-load drive motor; the two-position two-way throttle valve on the low-load side maintains a larger opening, achieving on-demand flow distribution. This dynamic adjustment method of "one increasing while the other decreases" allows the front and rear wheels to automatically match their speeds according to the actual steering radius, effectively solving the trajectory deviation problem caused by the passive following of the rear wheels in traditional vehicles, and significantly improving steering accuracy and coordination.

[0013] Achieving "fuzzy output" adaptive flow distribution enhances the system's intelligence level: The "fuzzy output" referred to in this system does not mean signal fuzziness, but rather that the system can dynamically and non-fixedly distribute the front and rear wheel drive flow according to changes in working conditions. This process does not require intervention from an external electronic controller and is completed automatically entirely by the physical feedback mechanism of the hydraulic system (LS signal + throttle valve linkage), realizing an intelligent response of "quasi-fuzzy control" with the advantages of fast response, high reliability, and strong anti-interference ability.

[0014] III. Energy-efficient and highly effective, improving energy utilization efficiency: The main pump's displacement is adjusted in real time by the flow and pressure control valve based on the LS feedback signal, outputting only the pressure and flow rate required for the highest load, thus avoiding overflow losses typical of fixed displacement pump systems. The system's operating pressure always closely matches the actual load, significantly reducing ineffective power consumption and aligning with energy-saving and environmentally friendly design trends. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an enlarged view of the structure at point A in this utility model.

[0017] In the diagram: 2. Return oil filter element; 3. Pressure signal switch; 4. Back pressure check valve; 5. Main pump; 6. Throttle valve; 7. Oil pump control cylinder; 8-1. Adjustable flow valve one; 8-2. Adjustable flow valve two; 9. Safety unloading protection valve; 10-1. Check valve one; 10-2. Check valve two; 11-1. Two-position two-way throttle valve one; 11-2. Two-position two-way throttle valve two; 12-1. Drive motor one; 12-2. Drive motor two; 13. Flow and pressure control valve. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] like Figure 1 , Figure 2As shown, the fuzzy output signal control drive system is applied to the differentiated control of the front and rear wheel drive motors during the turning process of large vehicles. The system includes a pump control system, a flow and pressure control system, a wheel drive system, and a return oil control system. The pump control system includes a main pump 5, an oil pump control cylinder 7, a flow and pressure control valve 13, and a throttle valve 6. The swashplate on the main pump 5 is connected to the piston rod on the oil pump control cylinder 7, and the oil pump control cylinder 7 has ports A and B. The flow and pressure control valve 13 has ports C, D, and P, as well as ports Z on both sides and a spring end K. Port A of the oil pump control cylinder 7 is connected to the flow and pressure control valve 13. Ports C and Z on the 3 are connected. Port B of the oil pump control cylinder 7 is connected to port P of the flow and pressure control valve 13. Port D of the flow and pressure control valve 13 is connected to the return oil control system. The wheel system includes at least two drive motors, namely drive motor 12-1 and drive motor 12-2. The flow and pressure control system includes adjustable flow valve 8-1, adjustable flow valve 8-2, a two-position two-way throttle valve, and a load sensing feedback oil circuit. The two-position two-way throttle valve includes two-position two-way throttle valve 11-1 and two-position two-way throttle valve 11-2. Drive motor 12-1 is connected to two-position two-way throttle valve 11-1. The adjustable flow valve 8-1 is on one branch, while the drive motor 12-2, the two-position two-way throttle valve 11-2, and the adjustable flow valve 8-2 are on another branch. The two-position two-way throttle valve 11-1 has ports E, F, H, and a spring end port G. The two-position two-way throttle valve 11-2 has ports I, L, H, and a spring end port J. The oil inlet of the adjustable flow valve 8-1 is connected to the oil outlet of the main pump 5, and the oil outlet of the adjustable flow valve 8-1 is connected to ports E and H of the two-position two-way throttle valve 11-1. The F port of the two-position two-way throttle valve 11-1 is connected to the drive motor 12-1. The inlet of the main pump 5 is connected to the inlet of the adjustable flow valve 8-2, and the outlet of the adjustable flow valve 8-2 is connected to the L port and N port of the two-position two-way throttle valve 11-2. The I port of the two-position two-way throttle valve 11-2 is connected to the inlet of the drive motor 12-2. The load sensing feedback oil circuit is connected to the spring end K port of the flow and pressure control valve 13. The system collects the highest load pressure signal of each drive motor in real time through the load sensing feedback oil circuit, feeds it back to the flow and pressure control valve 13, and adjusts the displacement of the main pump 5 so that the outlet pressure of the main pump 5 follows the dynamic change of the highest load pressure.

[0021] On the same branch, the opening actions of the two-position two-way throttle valve 11-1 and the adjustable flow valve 8-1 are not synchronized or the same.

[0022] The opening of the adjustable flow valve 8-1 is preset and relatively fixed, reflecting the flow demand; the opening of the two-position two-way throttle valve 11-1 is dynamically changed and automatically adjusted by load feedback, used to achieve load compensation and system pressure coordination; the two work together, but their functions are clearly divided and their action mechanisms are independent, together achieving "fuzzy output" type adaptive flow distribution.

[0023] "Fuzzy output" refers to the system automatically adjusting the opening of the throttle valves in each branch circuit according to the difference in steering load between the front and rear wheels through the load sensing feedback oil circuit, so as to achieve a non-fixed ratio and dynamic coordination of flow distribution, so that the front and rear wheels can adapt to the steering radius at different speeds.

[0024] Assume that drive motor 12-1 (front wheel) has a load of PL1 and drive motor 2 12-2 (rear wheel) has a load of PL2, and load PL2 > load PL1.

[0025] The load sensing feedback oil circuit (LS oil circuit) leads PL2 to the spring end K port of the flow and pressure control valve 13, the spring end G port of the two-position two-way throttle valve 11-1, and the spring end JI port of the two-position two-way throttle valve 11-2. When the opening of the two-position two-way throttle valve 11-2 decreases, the valve port pressure difference ΔP increases, and the main pump 5 discharge increases. At the same time, because PL2 is large, the opening of the adjustable flow valve 8-2 reaches the set value first, and the system prioritizes to ensure the rear wheel flow Q2. The front wheel flow Q1 is automatically reduced by throttling through the two-position two-way throttle valve 1, realizing "fuzzy" differentiated output.

[0026] In a preferred embodiment of the present invention, the return oil control system includes a hydraulic oil tank, a return oil filter element 2, and a pressure signal switch 3. The oil inlet of the return oil filter element 2 is connected to the D port of the flow and pressure control valve 13 through a throttle valve 6, and the oil outlet of the return oil filter element 2 is connected to the hydraulic oil tank. The pressure signal switch 3 is connected between the oil inlet and the oil outlet of the return oil filter element 2. The oil return control system also includes a back pressure check valve 4, the oil inlet of which is connected to the oil inlet of the oil return filter element 2, and the oil outlet of which is connected to the oil outlet of the oil return filter element 2.

[0027] When the return oil filter element 2 gradually becomes clogged and the return oil back pressure reaches 0.25 MPa, the back pressure check valve 4 opens, and the oil is unloaded and returned to the oil tank; the pressure signal switch 3 is triggered, and a "clogging" signal is output to the controller. The controller then reduces the engine speed or reduces the displacement of the main pump 5, and the system enters the "power reduction" mode to avoid continuing to suck in dirty oil.

[0028] In another preferred embodiment of this utility model, the load sensing feedback oil circuit includes a one-way valve 10-1 and a one-way valve 10-2. The oil inlet of the one-way valve 10-1 is connected to the F port of the two-position two-way throttle valve 11-1, and the oil outlet of the one-way valve 10-1 is connected to the spring end G port of the two-position two-way throttle valve 11-1, the oil outlet of the adjustable flow valve 8-1, and the spring end K port of the flow and pressure control valve 13. The oil inlet of the one-way valve 10-2 is connected to the I port of the two-position two-way throttle valve 10-2, and the oil outlet of the one-way valve 10-2 is connected to the spring end J port of the two-position two-way throttle valve 10-2, the oil outlet of the adjustable flow valve 8-1, and the spring end K port of the flow and pressure control valve 13.

[0029] The load sensing feedback oil circuit collects the highest load pressure in each branch and synchronously leads this highest load pressure to the spring end G port of the two-position two-way throttle valve 11-1, the spring end J port of the two-position two-way throttle valve 11-2, and the spring end K port of the flow and pressure control valve 13. The flow and pressure control valve 13 receives the pressure signal from the load sensing feedback oil circuit and adjusts the displacement of the main pump 5 so that the outlet pressure of the main pump 5 dynamically changes with the highest load pressure. When a certain drive motor branch is the maximum load side, its corresponding two-position two-way throttle valve automatically closes because the pressure difference across the valve port is the smallest, forcing the main pump 5 to increase the outlet pressure to ensure the flow supply on that side. The two-position two-way throttle valves on the non-maximum load side close to a smaller degree, realizing the adaptive "fuzzy" distribution of the flow of the front and rear wheel drive motors.

[0030] Assuming that the load on drive motor 12-1 (front wheel) is PL1 and the load on drive motor 22-2 (rear wheel) is PL2, and the load PL2 > the load PL1, then the opening of the two-position two-way throttle valve 21-2 (large load side) will decrease, while the opening of the two-position two-way throttle valve 11-1 (small load side) will remain basically unchanged or slightly decrease, but will never increase.

[0031] Detailed mechanism: The LS signal is taken as the "highest load pressure in all branches", and it is sent simultaneously to the spring end K port of the flow pressure control valve 13, the spring end G port of the two-position two-way throttle valve 11-1, and the spring end J port of the two-position two-way throttle valve 11-2.

[0032] The pressure at the spring end of the flow and pressure control valve 13 increases, leading to valve core displacement and increased discharge of the main pump 5.

[0033] For a two-position two-way throttle valve, when the pressure at the spring end increases, the valve core moves toward the "closed" direction, and the opening can only decrease or remain unchanged, never increase.

[0034] The two-position two-way throttle valve 11-2 corresponding to the high-load branch drive motor 12-2: It is necessary to raise the pressure of the main pump 5 higher, so the two-position two-way throttle valve 11-2 is actively closed by the LS pressure to form additional throttling, and the opening degree becomes smaller.

[0035] The two-position two-way throttle valve 11-1 corresponding to the small load branch drive motor 12-1 has a relatively large opening. The LS pressure also acts on its spring end, so it can only be closed or kept closed, and will not be enlarged. If the system needs to further reduce the flow of the small load branch, the two-position two-way throttle valve 11-1 can be closed a little more.

[0036] Therefore, regardless of which side, the opening of the two-position two-way throttle valve is in the "closed" direction under the action of LS pressure. The only difference is how much it is closed; the side with a large load closes more, while the side with a small load closes less or basically maintains the same position.

[0037] In another preferred embodiment of the present invention, a safety unloading protection valve 9 is also included. The safety unloading protection valve 9 has an R port, an S port and a U port. The R port of the safety unloading protection valve 9 is connected to the oil outlet of the one-way valve 10-1, and the S port and U port of the safety unloading protection valve 9 are respectively connected to the oil outlet of the hydraulic oil tank and the main pump 5.

[0038] If a bump occurs during a turn, causing the drive motor to momentarily overload and the pressure to exceed the set value of the safety unloading protection valve 9 (e.g., 25 MPa), the safety unloading protection valve 9 will open to overflow, protecting the motor and pipeline.

[0039] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0040] The embodiments of this utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A control and drive system with fuzzy output signals, applied to the differentiated control of the front and rear wheel drive motors during the turning process of large vehicles, characterized in that, The system includes a pump control system, a flow and pressure control system, a wheel system, and a return oil control system. The pump control system includes a main pump (5), an oil pump control cylinder (7), a flow and pressure control valve (13), and a throttle valve (6). The swashplate on the main pump (5) is connected to the piston rod on the oil pump control cylinder (7), and the oil pump control cylinder (7) has ports A and B. The flow and pressure control valve (13) has ports C, D, and P, as well as ports Z and spring end K located on both sides. Port A of the oil pump control cylinder (7) is connected to ports C and Z of the flow and pressure control valve (13). The B port of the oil pump control cylinder (7) is connected to the P port of the flow and pressure control valve (13), and the D port of the flow and pressure control valve (13) is connected to the return oil control system; the wheel system includes at least two drive motors, namely drive motor one (12-1) and drive motor two (12-2), and the flow and pressure control system includes adjustable flow valve one (8-1), adjustable flow valve two (8-2), two-position two-way throttle valve and load sensing feedback oil circuit, the two-position two-way throttle valve includes two-position two-way throttle valve one (11-1) and two-position two-way throttle valve two (11-2), and the... The two-position two-way throttle valve one (11-1) has ports E, F, H and a spring end G; the two-position two-way throttle valve two (11-2) has ports I, L, H and a spring end J; the inlet of the adjustable flow valve one (8-1) is connected to the outlet of the main pump (5), and the outlet of the adjustable flow valve one (8-1) is connected to ports E and H of the two-position two-way throttle valve one (11-1); the F port of the two-position two-way throttle valve one (11-1) is connected to the inlet of the drive motor one (12-1); the inlet of the adjustable flow valve two (8-2) is connected to the main pump (5). The oil outlet is connected, and the oil outlet of the adjustable flow valve two (8-2) is connected to the L port and N port of the two-position two-way throttle valve two (11-2). The I port of the two-position two-way throttle valve two (11-2) is connected to the oil inlet of the drive motor two (12-2). The load sensing feedback oil circuit is connected to the spring end K port of the flow pressure control valve (13). The system collects the highest load pressure signal of each drive motor in real time through the load sensing feedback oil circuit, feeds it back to the flow pressure control valve (13), and adjusts the displacement of the main pump (5) so that the outlet pressure of the main pump (5) follows the dynamic change of the highest load pressure.

2. The control and driving system for the fuzzy output signal according to claim 1, characterized in that, The oil return control system includes a hydraulic oil tank, an oil return filter element (2), and a pressure signal switch (3). The oil inlet of the oil return filter element (2) is connected to the D port of the flow and pressure control valve (13) through a throttle valve (6). The oil outlet of the oil return filter element (2) is connected to the hydraulic oil tank. The pressure signal switch (3) is connected between the oil inlet and the oil outlet of the oil return filter element (2).

3. The control and driving system for the fuzzy output signal according to claim 2, characterized in that, The oil return control system also includes a back pressure check valve (4), the oil inlet of which is connected to the oil inlet of the oil return filter element (2), and the oil outlet of which is connected to the oil outlet of the oil return filter element (2).

4. The control and drive system for fuzzy output signals according to claim 1, characterized in that, The load sensing feedback oil circuit includes a one-way valve (10-1) and a one-way valve (10-2). The oil inlet of the one-way valve (10-1) is connected to the F port of the two-position two-way throttle valve (11-1). The oil outlet of the one-way valve (10-1) is connected to the spring end G port of the two-position two-way throttle valve (11-1), the oil outlet of the adjustable flow valve (8-1), and the spring end K port of the flow and pressure control valve (13). The oil inlet of the one-way valve (10-2) is connected to the I port of the two-position two-way throttle valve (11-2), and the oil outlet of the one-way valve (10-2) is connected to the spring end J port of the two-position two-way throttle valve (11-2), the oil outlet of the adjustable flow valve (8-1), and the spring end K port of the flow and pressure control valve (13).

5. The control and driving system for the fuzzy output signal according to claim 4, characterized in that, The load sensing feedback oil circuit collects the highest load pressure in each branch and synchronously leads the highest load pressure to the spring end G port of the two-position two-way throttle valve one (11-1), the spring end J port of the two-position two-way throttle valve two (11-2), and the spring end K port of the flow and pressure control valve (13). The flow and pressure control valve (13) receives the pressure signal from the load sensing feedback oil circuit and adjusts the displacement of the main pump (5) so that the outlet pressure of the main pump (5) changes dynamically with the maximum load pressure. When a certain drive motor branch is the maximum load side, its corresponding two-position two-way throttle valve automatically closes because the pressure difference before and after the valve port is the smallest, forcing the main pump (5) to increase the outlet pressure to ensure the flow supply on that side. The two-position two-way throttle valves on the non-maximum load side close to a smaller degree, realizing the adaptive distribution of the flow of the front and rear wheel drive motors.

6. The control and drive system for fuzzy output signals according to claim 1, characterized in that, It also includes a safety unloading protection valve (9), which has an R port, an S port and a U port. The R port of the safety unloading protection valve (9) is connected to the oil outlet of the one-way valve (10-1), and the S port and U port of the safety unloading protection valve (9) are respectively connected to the oil outlet of the hydraulic oil tank and the main pump (5).

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