A hydrostatically driven full hydraulic differential steering control system and control method

Abstract

The present invention belongs to the technical field of steering devices for vehicles in underground coal mines, and specifically is a fully hydraulic differential steering control system and control method driven by static pressure. The present invention solves the problem of left and right wheel differential steering synchronization when similar vehicles such as support transport vehicles in underground coal mines are turned, and includes a left closed pump and a right closed pump connected to a power source. The two oil ports of the left closed pump are respectively connected to the left front motor and the right front motor through a left high-pressure buffer valve group. The left front motor is connected in parallel with the right front motor. A left hydraulically controlled flow diverter and collector valve is connected in series to the parallel circuit of the left front motor and the right front motor. One end of the left hydraulically controlled flow diverter and collector valve is connected to the left high-pressure buffer valve group, and the other end is connected to two hydraulic motors. The control port of the left hydraulically controlled flow diverter and collector valve is connected to the control oil source. The fully hydraulic differential steering control system of the present invention is completely a hydraulic component, and the anti-pollution energy of the system is greatly increased, which ensures the stability of the system and the safety of driving.

Description

Technical Field

[0001] The invention belongs to the technical field of steering devices for vehicles in underground coal mines, and in particular is a hydrostatically driven full hydraulic differential steering control system and a control method. Background Art

[0002] The support transporter in the coal mine adopts hydrostatic drive. Due to the special explosion-proof requirements of the coal mine, the flow of the closed system cannot be controlled by electronic closed loop. The frame vehicle adopts articulated steering. In order to realize differential steering during steering, a cam mechanism is generally set at the central hinge. The cam mechanism is connected to the differential valve. When the vehicle turns, the displacement of the push rod of the differential valve is changed to control the swash plate angle of the closed pump. However, the disadvantage is that the processing and manufacturing accuracy of the cam mechanism is difficult to guarantee, and the mechanical wear of the cam causes the displacement of the inner and outer pumps to fail to achieve the expected effect, and the subsequent maintenance cost is high.

[0003] Since the left and right motor drives of the hydraulic travel system are independent of each other, it is not easy for the inner and outer wheels to achieve differential speed when the vehicle turns. At present, there is a problem of synchronization of differential steering of the left and right wheels when similar vehicles such as underground coal mine support transport vehicles turn. The frame vehicle will cause the vehicle to skid and slip due to the speed difference between the left and right tires, causing vehicle tire wear, reduced operating efficiency, damage to components and even coal mine safety accidents. Summary of the invention

[0004] In order to solve the problem of left and right wheel differential steering synchronization when similar vehicles such as coal mine support transport vehicles turn, the present invention provides a hydrostatically driven full hydraulic differential steering control system and a control method.

[0005] The present invention adopts the following technical scheme: a hydrostatically driven full hydraulic differential steering control system, comprising a left closed pump and a right closed pump connected to a power source, the two oil ports of the left closed pump are respectively connected to the left front motor and the right front motor through the left high-pressure buffer valve group, the left front motor is connected in parallel with the right front motor, a left hydraulically controlled diverter and collector valve is connected in series on the parallel circuit of the left front motor and the right front motor, one end of the left hydraulically controlled diverter and collector valve is connected to the left high-pressure buffer valve group, and the other end is connected to two hydraulic motors, and the control port of the left hydraulically controlled diverter and collector valve is connected to the control oil source.

[0006] The two oil ports of the right closed pump are respectively connected to the left rear motor and the right rear motor through the right high-pressure buffer valve group. The left rear motor and the right rear motor are connected in parallel. A right hydraulically controlled diverter and collector valve is connected in series on the parallel circuit of the left rear motor and the right rear motor. One end of the right hydraulically controlled diverter and collector valve is connected to the right high-pressure buffer valve group, and the other end is connected to two hydraulic motors. The control port of the right hydraulically controlled diverter and collector valve is connected to the control oil source.

[0007] The oil port of the left closed pump is also connected to the left flow control valve, the flow control valve is connected to the a1 port of the left equivalent liquid bridge, and the equivalent two sides of the left equivalent liquid bridge are connected to the one-way proportional sequence valve of the left external control inner row; the c1 port of the left equivalent liquid bridge is connected to the oil port of the right closed pump; the oil port of the right closed pump is also connected to the right flow control valve, the right flow control valve is connected to the c2 port of the right equivalent liquid bridge, and the equivalent two sides of the right equivalent liquid bridge are connected to the one-way proportional sequence valve of the right external control inner row; the a2 port of the right equivalent liquid bridge is connected to the oil port of the left closed pump; the P port of the one-way proportional sequence valve of the left external control inner row and the P port of the one-way proportional sequence valve of the right external control inner row are both connected to the Ls port of the dynamic load-sensitive full hydraulic steering gear and the small accumulator, and the L port and R port of the dynamic load-sensitive full hydraulic steering gear are respectively connected to the left and right steering cylinders.

[0008] The left flow control valve includes an adjusting screw, an adjusting pad sealed with the adjusting screw, a throttle valve core and a valve core bottom plate connected with the adjusting pad, and a valve body sealed with the valve core bottom plate; the throttle valve core is communicated with the left side of the differential pressure regulator through a pipeline, the differential pressure regulator is connected with the regulator pilot valve, and the valve seat of the regulator pilot valve is plugged into the valve body through a seal; the valve body is provided with a P port, an R port and an A port, the P port connects the differential pressure regulator with the outside world, the R port connects the regulator pilot valve with the outside world, and the A port connects the throttle valve core, the channel with the outside world; the right flow control valve has the same structure as the left flow control valve.

[0009] Among them: the flow control valve is used in parallel with the throttle valve through a pressure compensator, which can realize stepless adjustment of the effective flow entering the load. The adjusted flow value has nothing to do with the system pressure and oil viscosity. High-pressure oil enters the flow control valve through the P port. By adjusting the screw of the A port, the flow entering the load from the A port is adjusted. The excess flow is separated from the R port. The amount of separated flow depends on the pressure difference between the A port and the P port and the pressure guide area. This flow control valve has a load-sensitive characteristic, that is, the outlet pressure of the pump changes with the load, so that the flow on both sides of the vehicle is close to the theoretical value to the greatest extent, so that the inner and outer wheels can roll purely when turning.

[0010] A control method for a hydrostatically driven full hydraulic differential steering control system, when a vehicle is traveling in a straight line, the valve core of a dynamic load sensitive full hydraulic steering gear is in a neutral position, the hydraulic oil directly returns from the P port of the dynamic load sensitive full hydraulic steering gear to the T port, the steering cylinder does not move, the Ls port of the dynamic load sensitive full hydraulic steering gear does not generate a pressure feedback signal, the left and right externally controlled internally discharged one-way proportional sequential valves are in an initial closed state, the high and low pressure oil sources of the left and right closed pumps are independent of each other, when the wheels on one side stall and slip, the wheels on the other side can still provide traction to help the vehicle get out of trouble; when one of the wheels on the same side slips, the pressure oil provided by the hydraulic pump is forced to be evenly distributed to the two wheels on the same side by controlling the control port of the hydraulically controlled diverter and collector valve on that side.

[0011] When the vehicle turns, the driver controls the steering wheel to drive the valve core of the dynamic load-sensitive full hydraulic steering gear to rotate, and the pressure oil enters the steering cylinder through the steering gear oil channel to drive the vehicle to turn. Since the flow of the left and right motors is the same, the speed difference of the inner and outer tires cannot be achieved. When turning, the high-pressure hydraulic oil at the Ls feedback port of the dynamic load-sensitive full hydraulic steering gear pushes the left and right external control inner discharge one-way proportional sequential valves to change direction. The left and right closed pump oil outlets are high-pressure side hydraulic oil, and the oil intake is low-pressure side hydraulic oil. When the vehicle is articulated and turned, the lateral force on the vehicle is different, which makes the wheels on the left and right sides The driving resistance is different, one side has greater resistance and the other side has less resistance. At this time, it is a parallel oil circuit, and the pressure oil source automatically performs secondary distribution according to the size of the driving resistance. The hydraulic oil flow on the side with greater resistance is less, and the hydraulic oil flow on the side with less resistance is more. The hydraulic oil on the side with greater resistance passes through the one-way valve of the equivalent liquid bridge, the one-way proportional sequence valve with external control and internal discharge, and the other one-way valve and flow control valve of the equivalent liquid bridge into the motor on the side with less resistance, causing the speed of the motor on the side with less resistance to increase and the speed of the motor on the side with greater resistance to decrease, thereby causing the motor to have a speed difference, thereby achieving smooth steering of the vehicle.

[0012] Due to the different steering angles, the differential flow ratio of the inner and outer motors is also different. The present invention can firstly use the one-way proportional sequential valve with external control and internal discharge to proportionally adjust the flow passing through the valve according to the pressure of the steering gear feedback port Ls, so that the inner and outer wheels can achieve smooth steering at different steering angles. Secondly, the flow control valve has a pressure difference adjustment function, which can achieve constant pressure between the oil inlet and the oil outlet, and can achieve excess flow back to the oil tank. The amount of returned oil can adjust the throttling adjustment screw of the flow control valve to achieve the speed difference of the vehicle to meet the Ackerman steering.

[0013] When the vehicle is driving normally, the high-pressure buffer valve group does not work, and the hydraulic oil on the high- and low-pressure sides of the closed system are independent of each other and not interfered with. When encountering a large obstacle or the system pressure suddenly increases to more than 350Bar, in order to avoid affecting the vehicle's driving performance and the life of hydraulic components, the motor return oil passes through the two-way buffer valve and overflow valve in the high-pressure buffer valve group to achieve a constant pressure difference between the high- and low-pressure sides of the closed system, ensuring that the system is not overloaded and avoiding excessive impact of the closed system's ultra-high pressure on the equivalent liquid bridge, causing damage to components, causing the vehicle to stall, and affecting the normal driving of the vehicle.

[0014] A small control accumulator is added to the circuit from the dynamic load-sensitive full hydraulic steering gear to the externally controlled internally discharged one-way proportional sequence valve to ensure stable pressure fluctuations at the Ls feedback port, thereby stabilizing the working characteristics of the externally controlled internally discharged one-way proportional sequence valve and ensuring stable and safe steering.

[0015] Compared with the prior art, the present invention uses the high-pressure oil source of the pressure feedback Ls port of the steering gear as the control signal, and proportionally controls the one-way proportional sequence valve of the external control inner row through the pilot pressure of the steering gear Ls feedback port, so that the hydraulic oil of the inner motor can flow into the hydraulic oil of the outer motor at different flow rates depending on the steering angle. At the same time, the flow rate of the inner and outer sides can be secondary adjusted through the flow control valve, thereby ensuring the sensitivity, synchronization and followability of the steering system, ensuring the connection between the high-pressure side and the low-pressure side of the closed system, and ensuring that the vehicle will not slip or drag. The hydrostatically driven full-hydraulic differential steering control system of the present invention is completely hydraulic, and the system's anti-pollution ability and reliability are greatly increased, thereby ensuring the stability of the system and driving safety. The full hydraulic differential steering control system of the present invention is different from a general differential steering control device in that the driving system used by the support transporter can realize differential steering by using the full hydraulic differential steering control system when steering, regardless of whether it is left-right independent drive or front-back independent drive. The present invention cleverly uses the pressure feedback Ls port of the steering gear as a signal to ensure the sensitivity and followability of the control, and at the same time controls the liquid flow through the liquid bridge to ensure that the high-pressure side and the low-pressure side of the closed system are connected. By calculating the speed difference between the inner and outer wheels and adjusting the throttle valve opening, it is ensured that the vehicle will not slip or drag. The full hydraulic differential steering control system of the present invention is completely a hydraulic component, and the anti-pollution energy of the system is greatly increased, ensuring the stability of the system and the safety of driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a full hydraulic differential steering control system;

[0017] Figure 2 Schematic diagram of the flow control valve structure. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, a hydrostatically driven full hydraulic differential steering control system comprises a left closed pump 2a and a right closed pump 2b connected to a power source 1, wherein two oil ports of the left closed pump 2a are respectively connected to a left front motor 8a1 and a right front motor 8a2 through a left high-pressure buffer valve group 6a, the left front motor 8a1 and the right front motor 8a2 are connected in parallel, a left hydraulically controlled diverter and collector valve 7a is connected in series to the parallel circuit of the left front motor 8a1 and the right front motor 8a2, one end of the left hydraulically controlled diverter and collector valve 7a is connected to the left high-pressure buffer valve group 6a, and the other end is connected to two hydraulic motors, and a control port of the left hydraulically controlled diverter and collector valve 7a is connected to a control oil source.

[0019] The two oil ports of the right closed pump 2b are respectively connected to the left rear motor 8b1 and the right rear motor 8b2 through the right high-pressure buffer valve group 6b. The left rear motor 8b1 and the right rear motor 8b2 are connected in parallel. A right hydraulically controlled diverter and collector valve 7b is connected in series to the parallel circuit of the left rear motor 8b1 and the right rear motor 8b2. One end of the right hydraulically controlled diverter and collector valve 7b is connected to the right high-pressure buffer valve group 6b, and the other end is connected to two hydraulic motors. The control port of the right hydraulically controlled diverter and collector valve 7b is connected to the control oil source.

[0020] The oil port of the left closed pump 2a is also connected to the left flow control valve 3a, the flow control valve 3a is connected to the a1 port of the left equivalent liquid bridge 4a, and the equivalent two sides of the left equivalent liquid bridge 4a are connected to the one-way proportional sequence valve 5a of the left external control inner discharge; the c1 port of the left equivalent liquid bridge 4a is connected to the oil port of the right closed pump 2b; the oil port of the right closed pump 2b is also connected to the right flow control valve 3b, the right flow control valve 3b is connected to the c2 port of the right equivalent liquid bridge 4b, and the right equivalent liquid bridge The equivalent two sides of 4b are connected to the one-way proportional sequence valve 5b of the right external control inner row; the a2 port of the right equivalent liquid bridge 4b ​​is connected to the oil port of the left closed pump 2a; the P port of the one-way proportional sequence valve 5a of the left external control inner row and the P port of the one-way proportional sequence valve 5b of the right external control inner row are both connected to the Ls port of the dynamic load-sensitive full hydraulic steering gear 10 and the small accumulator 11, and the L port and R port of the dynamic load-sensitive full hydraulic steering gear 10 are respectively connected to the left and right steering cylinders 9.

[0021] The left flow control valve 3a includes an adjusting screw 12, an adjusting pad 13 sealed with the adjusting screw 12, a throttle valve core 14 and a valve core bottom plate 15 connected to the adjusting pad 13, and a valve body 16 sealed with the valve core bottom plate 15; the throttle valve core 14 is communicated with the left side of the differential pressure regulator 17 through a pipeline, the differential pressure regulator 17 is connected with the regulator pilot valve 18, and the valve seat 19 of the regulator pilot valve 18 is plugged into the valve body 16 through a seal; the valve body 16 is provided with a P port, an R port and an A port, the P port connects the differential pressure regulator 17 with the outside world, the R port connects the regulator pilot valve 18 with the outside world, and the A port connects the throttle valve core 14, the channel and the outside world; the right flow control valve 3b has the same structure as the left flow control valve 3a.

[0022] The left closed pump and the two left hydraulic motors form the left closed hydraulic system, and the right closed pump and the two right hydraulic motors form the right closed hydraulic system. The two closed hydraulic systems drive the left and right wheels respectively to realize the driving of the vehicle. A hydraulically controlled flow divider and collector valve is connected in series in each closed hydraulic circuit. One end of the hydraulically controlled flow divider and collector valve is connected to the hydraulic pump, and the other end is connected to the two hydraulic motors. The control port of the hydraulically controlled flow divider and collector valve is connected to the control oil source. When the wheel slips, the control port of the hydraulically controlled flow divider and collector valve is controlled to make the hydraulically controlled flow divider and collector valve work in a forced flow condition, limit the flow through the slipping motor, keep the motor speed synchronized, and the motor displacement does not change with the load, so as to realize the normal driving of the vehicle; one side of the closed pump driving on the right is connected to the other side of the left motor through the flow control valve and the equivalent liquid bridge. The equivalent two sides of the equivalent liquid bridge are connected to the one-way proportional sequence valve of the external control inner row, and the one-way proportional sequence valve of the external control inner row is connected to the small accumulator and the dynamic load-sensitive full hydraulic steering gear. The high-pressure buffer valve group is connected in series on both sides of the high and low pressure of the closed pump respectively.

[0023] When the vehicle is traveling in a straight line, the valve core of the dynamic load-sensitive full hydraulic steering gear is in the middle position, the hydraulic oil returns directly from the P port of the dynamic load-sensitive full hydraulic steering gear to the T port, the steering cylinder does not move, and the Ls port of the dynamic load-sensitive full hydraulic steering gear does not generate a pressure feedback signal, so the one-way proportional sequence valves of the external control and internal row on the left and right sides are in the initial closed state. The high and low pressure oil sources of the closed pumps on both sides are independent of each other. At this time, the closed system drive circuits on the left and right sides are independent of each other and are not interfered with. Since both sides are driving wheels, when one wheel stalls and slips, the other wheel can still provide a certain amount of traction to help the vehicle get out of trouble; when one of the wheels on the same side slips, the control port of the hydraulically controlled diverter and collector valve is controlled to force the pressure oil provided by the hydraulic pump to be evenly distributed to the two wheels on the same side, which will not cause one wheel to lose traction due to lack of pressure oil inflow, nor will it cause the other vehicle to slip due to excessive traffic.

[0024] When the vehicle turns, the driver controls the steering wheel to drive the valve core of the dynamic load-sensitive full hydraulic steering gear to rotate, and the pressure oil enters the steering cylinder through the steering gear oil channel to drive the vehicle to turn. Since the flow of the inner and outer motors is the same, the speed difference of the inner and outer tires cannot be achieved. When turning, the high-pressure hydraulic oil at the Ls feedback port of the dynamic load-sensitive full hydraulic steering gear pushes the one-way proportional sequence valve of the external control inner discharge to change direction. The closed pump outlet is the high-pressure side hydraulic oil, and the oil intake is the low-pressure side hydraulic oil. When the vehicle is articulated and turned, the lateral force on the vehicle is different, which makes the driving resistance of the wheels on the left and right sides different, with greater resistance on the inside and less resistance on the outside. Since it is a parallel oil circuit at this time, the pressure oil source automatically performs secondary distribution according to the size of the driving resistance. The inner hydraulic oil flow rate is smaller with large resistance, while the outer hydraulic oil flow rate is larger with small resistance. Therefore, the inner hydraulic oil passes through the one-way valve of the equivalent liquid bridge, the one-way proportional sequence valve of the external control inner discharge, and then through another one-way valve of the equivalent liquid bridge and the flow control valve to enter the outer motor, causing the outer motor speed to increase and the inner motor speed to decrease, thereby causing the motor to have a speed difference, so that the differential speed of the inner and outer wheels can be automatically achieved, and the outer motor speed is faster, thereby achieving smooth steering of the vehicle. Due to the different steering angles, the differential flow ratio of the inner and outer motors is also different. The present invention can firstly use the one-way proportional sequential valve with external control and internal discharge to proportionally adjust the flow passing through the valve according to the pressure of the steering gear feedback port Ls, so that the inner and outer wheels can achieve smooth steering at different steering angles. Secondly, the flow control valve has a pressure difference adjustment function, which can achieve constant pressure between the oil inlet and the oil outlet, and can achieve excess flow back to the oil tank. The amount of returned oil can adjust the throttling adjustment screw of the flow control valve to achieve the speed difference of the vehicle to meet the Ackerman steering.

[0025] When the vehicle is driving normally, the high-pressure buffer valve group does not work, and the hydraulic oil on the high- and low-pressure sides of the closed system are independent of each other and not interfered with. When encountering a large obstacle or the system pressure suddenly increases to more than 350Bar, in order to avoid affecting the vehicle's driving performance and the life of hydraulic components, the motor return oil passes through the two-way buffer valve and overflow valve in the high-pressure buffer valve group to achieve a constant pressure difference between the high- and low-pressure sides of the closed system, ensuring that the system is not overloaded and avoiding excessive impact of the closed system's ultra-high pressure on the equivalent liquid bridge, causing damage to components, causing the vehicle to stall, and affecting the normal driving of the vehicle.

[0026] A small control accumulator is added to the circuit from the dynamic load-sensitive full hydraulic steering gear to the externally controlled internally discharged one-way proportional sequence valve to ensure stable pressure fluctuations at the Ls feedback port, thereby stabilizing the working characteristics of the externally controlled internally discharged one-way proportional sequence valve and ensuring stable and safe steering.

Claims

1. A hydrostatically driven full hydraulic differential steering control system, characterized in that: It comprises a left closed pump (2a) and a right closed pump (2b) connected to a power source (1); the two oil ports of the left closed pump (2a) are respectively connected to the left front motor (8a1) and the right front motor (8a2) through the left high-pressure buffer valve group (6a); the left front motor (8a1) and the right front motor (8a2) are connected in parallel; a left hydraulically controlled flow dividing and collecting valve (7a) is connected in series to the parallel circuit of the left front motor (8a1) and the right front motor (8a2); one end of the left hydraulically controlled flow dividing and collecting valve (7a) is connected to the left high-pressure buffer valve group (6a); the other end is connected to the two hydraulic motors; the control port of the left hydraulically controlled flow dividing and collecting valve (7a) is connected to the control oil source; The two oil ports of the right closed pump (2b) are respectively connected to the left rear motor (8b1) and the right rear motor (8b2) through the right high-pressure buffer valve group (6b); the left rear motor (8b1) and the right rear motor (8b2) are connected in parallel; a right hydraulically controlled flow dividing and collecting valve (7b) is connected in series to the parallel circuit of the left rear motor (8b1) and the right rear motor (8b2); one end of the right hydraulically controlled flow dividing and collecting valve (7b) is connected to the right high-pressure buffer valve group (6b), and the other end is connected to the two hydraulic motors; the control port of the right hydraulically controlled flow dividing and collecting valve (7b) is connected to the control oil source; The oil port of the left closed pump (2a) is also connected to the left flow control valve (3a), the left flow control valve (3a) is connected to the a1 port of the left equivalent liquid bridge (4a), and the equivalent two sides of the left equivalent liquid bridge (4a) are connected to the left one-way proportional sequence valve (5a) of the left external control inner discharge; the c1 port of the left equivalent liquid bridge (4a) is connected to the oil port of the right closed pump (2b); the oil port of the right closed pump (2b) is also connected to the right flow control valve (3b), the right flow control valve (3b) is connected to the c2 port of the right equivalent liquid bridge (4b), and the right equivalent liquid The equivalent two sides of the bridge (4b) are connected to the right-side one-way proportional sequence valve (5b) of the right-side external control inner row; the a2 port of the right-side equivalent liquid bridge (4b) is connected to the oil port of the left-side closed pump (2a); the P port of the left-side one-way proportional sequence valve (5a) of the left-side external control inner row and the P port of the right-side one-way proportional sequence valve (5b) of the right-side external control inner row are both connected to the Ls port of the dynamic load-sensing full hydraulic steering gear (10) and the small accumulator (11), and the L port and R port of the dynamic load-sensing full hydraulic steering gear (10) are respectively connected to the left and right steering cylinders (9).

2. The hydrostatically driven full hydraulic differential steering control system according to claim 1, characterized in that: The left flow control valve (3a) comprises an adjusting screw (12), an adjusting pad (13) sealedly connected to the adjusting screw (12), a throttle valve core (14) and a valve core bottom plate (15) connected to the adjusting pad (13), and a valve body (16) sealedly connected to the valve core bottom plate (15); the throttle valve core (14) is connected to the left side of the differential pressure regulator (17) through a pipeline, the differential pressure regulator (17) is connected to the regulator pilot valve (18), and the valve seat (19) of the regulator pilot valve (18) is plugged into the valve body (16) through a sealing plug; the valve body (16) is provided with a P port, an R port, and an A port, the P port connects the differential pressure regulator (17) with the outside world, the R port connects the regulator pilot valve (18) with the outside world, and the A port connects the throttle valve core (14), the channel, and the outside world; The right flow control valve (3b) has the same structure as the left flow control valve (3a).

3. A control method for a hydrostatically driven full hydraulic differential steering control system as claimed in claim 2, characterized in that: When the vehicle is traveling in a straight line, the valve core of the dynamic load-sensitive full hydraulic steering gear (10) is in the middle position, the hydraulic oil returns directly from the P port of the dynamic load-sensitive full hydraulic steering gear (10) to the T port, the steering cylinder does not move, the Ls port of the dynamic load-sensitive full hydraulic steering gear (10) does not generate a pressure feedback signal, the left and right side externally controlled internally discharged one-way proportional sequence valves are in the initial closed state, and the high and low pressure oil sources of the left and right closed pumps are independent of each other. When the wheels on one side stall and slip, the wheels on the other side can still provide traction to help the vehicle get out of trouble; when one of the wheels on the same side slips, the pressure oil provided by the hydraulic pump is forced to be evenly distributed to the two wheels on the same side by controlling the control port of the hydraulically controlled flow dividing and collecting valve on that side; When the vehicle turns, the driver controls the steering wheel to drive the valve core of the dynamic load-sensitive full hydraulic steering gear (10) to rotate, and the pressure oil enters the steering cylinder through the steering gear oil channel to drive the vehicle to turn. Since the flow of the left and right motors is the same, the speed difference of the inner and outer tires cannot be achieved. When turning, the high-pressure hydraulic oil at the Ls feedback port of the dynamic load-sensitive full hydraulic steering gear (10) drives the left and right side one-way proportional sequential valves of the outer control inner discharge on the left and right sides to change direction. The oil outlets of the left and right closed pumps are the high-pressure side hydraulic oil, and the oil intakes are the low-pressure side hydraulic oil. When the vehicle is articulated and turned, the lateral force on the vehicle is different, which causes the left and right sides to The driving resistance of the wheels is different, one side has greater resistance and the other side has less resistance. At this time, it is a parallel oil circuit, and the pressure oil source automatically performs secondary distribution according to the size of the driving resistance. The hydraulic oil flow on the side with greater resistance is less, and the hydraulic oil flow on the side with less resistance is more. The hydraulic oil on the side with greater resistance passes through the one-way valve of the equivalent liquid bridge, the left and right one-way proportional sequential valves of the external control and internal discharge, and the other one-way valve of the equivalent liquid bridge and the left and right flow control valves into the motor on the side with less resistance, causing the speed of the motor on the side with less resistance to increase and the speed of the side with greater resistance to decrease, thereby causing the motor to have a speed difference, thereby achieving smooth steering of the vehicle.

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