Aerial work platform and four-wheel drive travel control system

Abstract

The application discloses a high-altitude operation platform and a four-wheel drive walking control system, and the control system comprises a flow dividing and collecting device, a first hydraulic control valve, a second hydraulic control valve, a flushing valve, a shuttle valve and a control valve; the first oil port and the second oil port of the flow dividing and collecting device are communicated with the B port and the A port of a left rear walking motor respectively, the third oil port is communicated with the B port of a left front walking motor, the fourth oil port is communicated with the A port of the left front walking motor through the first hydraulic control valve, the fifth oil port is communicated with the A port of a right rear walking motor, the fourth oil port is also communicated with the B port of the right rear walking motor, the sixth oil port is communicated with the A port of a right front walking motor, and the second oil port is also communicated with the B port of the right front walking motor through the second hydraulic control valve. The application avoids the problem that the hydraulic oil driving the whole vehicle to walk is all wasted through the idle motor due to the front wheel slipping or being suspended, and the whole vehicle cannot walk under abnormal conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of drive control, and in particular relates to an aerial work platform and a four-wheel drive travel control system. Background Art

[0002] Four-wheel drive aerial work platforms utilize three flow divider and collector valves to distribute the hydraulic oil, input from port A or port B, evenly to the four travel motors, driving the vehicle. Each flow divider and collector valve is connected by a throttle oil passageway to adjust for differences in flow demand among the travel motors due to steering or ground conditions such as potholes and protrusions. The flow originally allocated equally to the four travel motors is adjusted through the throttle oil passageway, following the principle of hydraulic oil flowing from high pressure to low pressure, to the required travel motors. For example, during a turn, to ensure consistent angular velocity among the tires on the same chassis and prevent dragging, the flow demanded by the inner travel motor is lower than that of the outer travel motor. Therefore, the flow distributed to the inner travel motor will build up pressure due to the actual flow exceeding the required flow, causing the flow to self-adjust to the lower pressure outer travel motor through the throttle oil passageway.

[0003] The disadvantage of this travel control scheme is that when a tire slips or hangs in the air, the load is small and is on the low-pressure side, causing the flow that drives the entire vehicle to move to self-adjust to the tire through the throttle oil channel, causing the tire to idle and do useless work, resulting in the problem of the entire vehicle not moving. Summary of the Invention

[0004] The purpose of the present invention is to provide an aerial work platform and a four-wheel drive travel control system to solve the problem that due to a tire slipping or hanging in the air, the hydraulic oil that drives the entire vehicle to move does useless work through the idling motor, resulting in the entire vehicle not moving.

[0005] The present invention solves the above technical problems through the following technical solutions: a four-wheel drive travel control system, comprising a flow diverter and flow collector device, a first hydraulic control valve with a throttling function, a second hydraulic control valve with a throttling function, a flushing valve, a shuttle valve and a control valve; the first oil port and the second oil port of the flow diverter and flow collector device are respectively connected to the B port and the A port of the left rear travel motor, the third oil port of the flow diverter and flow collector device is connected to the B port of the left front travel motor, the fourth oil port of the flow diverter and flow collector device is connected to the A port of the left front travel motor through the first hydraulic control valve, the fifth oil port of the flow diverter and flow collector device is connected to the A port of the right rear travel motor, the fourth oil port of the flow diverter and flow collector device is also connected to the B port of the right rear travel motor, the sixth oil port of the flow diverter and flow collector device is connected to the A port of the right front travel motor, and the second oil port of the flow diverter and flow collector device is also connected to the B port of the right front travel motor through the second hydraulic control valve;

[0006] The seventh oil port and the eighth oil port of the diverter and collector device are respectively connected to the two ends of the shuttle valve, the seventh oil port of the diverter and collector device is also connected to the second oil port of the flushing valve, the eighth oil port of the diverter and collector device is also connected to the first oil port of the flushing valve, the first oil port of the flushing valve is also connected to the A port of the travel closed variable pump, the second oil port of the flushing valve is also connected to the B port of the travel closed variable pump, the third oil port of the flushing valve is connected to the hydraulic oil tank through the overflow valve; the control valve is connected to the control ports of the first and second hydraulic control valves and the ninth oil port of the diverter and collector device.

[0007] Furthermore, the flow diverter and collector device includes a first flow diverter and collector valve, a second flow diverter and collector valve, a third flow diverter and collector valve, a third hydraulic control valve, a fourth hydraulic control valve and a fifth hydraulic control valve;

[0008] The first oil distribution port of the first flow dividing and combining valve is communicated with the second oil distribution port of the first flow dividing and combining valve via a first damper. The first oil distribution port of the first flow dividing and combining valve is also communicated with the first oil distribution port of the third hydraulic control valve via a second damper. The second oil distribution port of the first flow dividing and combining valve is communicated with the second oil distribution port of the third hydraulic control valve.

[0009] The first oil branch port of the second flow dividing and combining valve is communicated with the second oil branch port of the second flow dividing and combining valve via a third damper. The first oil branch port of the second flow dividing and combining valve is further communicated with the first oil port of the fourth hydraulic control valve via a fourth damper. The second oil branch port of the second flow dividing and combining valve is communicated with the second oil port of the fourth hydraulic control valve.

[0010] The first oil branch port of the third flow diverter and collector valve is connected to the second oil branch port of the third flow diverter and collector valve through a fifth damper. The first oil branch port of the third flow diverter and collector valve is also connected to the first oil port of the fifth hydraulic control valve through a sixth damper. The second oil branch port of the third flow diverter and collector valve is connected to the second oil port of the fifth hydraulic control valve.

[0011] The first oil distribution port of the first diverter and collector valve is the first oil distribution port of the diverter and collector device, the first oil distribution port of the second diverter and collector valve is the second oil distribution port of the diverter and collector device, the second oil distribution port of the first diverter and collector valve is the third oil distribution port of the diverter and collector device, the second oil distribution port of the second diverter and collector valve is the fourth oil distribution port of the diverter and collector device, the first oil distribution port of the third diverter and collector valve is the fifth oil distribution port of the diverter and collector device, the second oil distribution port of the third diverter and collector valve is the sixth oil distribution port of the diverter and collector device, the oil collection ports of the first diverter and collector valve and the third diverter and collector valve are the seventh oil distribution port of the diverter and collector device, the oil collection port of the second diverter and collector valve is the eighth oil distribution port of the diverter and collector device, and the control ports of the third hydraulic control valve, the fourth hydraulic control valve and the fifth hydraulic control valve are the ninth oil distribution port of the diverter and collector device.

[0012] Furthermore, the flow dividing and collecting device further includes a first one-way valve and a second one-way valve; the first oil distribution port of the flow dividing and collecting valve is connected to the second oil distribution port of the flow dividing and collecting valve through the first one-way valve and the second one-way valve; the first one-way valve and the second one-way valve are connected to the oil charge pump integrated in the travel closed variable pump;

[0013] The flow diverter and collector valves include a first flow diverter and collector valve, a second flow diverter and collector valve, and a third flow diverter and collector valve.

[0014] Furthermore, the third oil port of the flushing valve is connected to the overflow valve through a seventh damper.

[0015] Furthermore, the left front travel motor, the left rear travel motor, the right front travel motor and the right rear travel motor are all equipped with variable displacement plungers, and the variable displacement plungers of the left front travel motor, the variable displacement plungers of the right front travel motor, the variable displacement plungers of the left rear travel motor and the variable displacement plungers of the right rear travel motor are connected to each other.

[0016] Furthermore, the control valve is a solenoid valve, and the solenoid valve is also connected to the shuttle valve and the hydraulic oil tank through a pressure reducing valve.

[0017] Furthermore, pressure measuring points are provided at the first oil port and the second oil port of the flush valve.

[0018] Based on the same concept, the present invention also provides an aerial work platform, which adopts the four-wheel drive travel control system as described above to perform travel drive control.

[0019] Beneficial effects

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] The four-wheel drive travel control system provided by the present invention adds a hydraulic control valve with a throttling function to the oil channels of the left and right front wheels respectively, which limits the flow input to the left front travel motor and the right front travel motor during low-speed travel, avoiding the hydraulic oil that drives the entire vehicle to travel to do useless work through the idling motors due to the front wheels slipping or hanging in the air, and allows part of the flow to flow from the left front travel motor and the right front travel motor (the high-pressure side formed by throttling the front wheel oil channel) to the left rear travel motor and the right rear travel motor on the low-pressure side, thereby realizing the travel of the entire vehicle under abnormal conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiment. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 2 is a schematic structural diagram of a four-wheel drive travel control system according to an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the hydraulic oil flow when the motor moves forward in an embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of adding a one-way valve to the four-wheel drive travel control system in an embodiment of the present invention.

[0026] Explanation of the reference numerals: 1-left rear travel motor, 2-left front travel motor, 3-right rear travel motor, 4-right front travel motor, 5-first diverter and collector valve, 6-third hydraulic control valve, 7-second diverter and collector valve, 8-fourth hydraulic control valve, 9-third diverter and collector valve, 10-fifth hydraulic control valve, 11-first hydraulic control valve, 12-second hydraulic control valve, 13-flush valve, 14-shuttle valve, 15-first one-way valve, 16-second one-way valve, 17-overflow valve, 18-variable displacement plunger, 19-pressure reducing valve, 20-solenoid valve, LRB-left rear travel motor B port, LRA-left rear travel motor A port, RRB-right rear travel motor B port, RRA-right rear travel motor A port, LFB-left front travel motor B port, LFA-left front travel motor A port, RFB-right front travel motor B port, RFA-right front travel motor A port, MA / MB-pressure measuring point. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0028] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0029] like Figure 1As shown, a four-wheel drive travel control system provided by an embodiment of the present invention includes a diverter and collector device, a first hydraulic control valve 11 with a throttling function, a second hydraulic control valve 12 with a throttling function, a flushing valve 13, a shuttle valve 14 and a control valve; the first oil port and the second oil port of the diverter and collector device are respectively connected to the B port and the A port of the left rear travel motor 1, the third oil port of the diverter and collector device is connected to the B port of the left front travel motor 2, the fourth oil port of the diverter and collector device is connected to the A port of the left front travel motor 2 through the first hydraulic control valve 11, the fifth oil port of the diverter and collector device is connected to the A port of the right rear travel motor 3, the fourth oil port of the diverter and collector device is also connected to the B port of the right rear travel motor 3, the sixth oil port of the diverter and collector device is connected to the A port of the right front travel motor 4, and the second oil port of the diverter and collector device is also connected to the B port of the right front travel motor 4 through the second hydraulic control valve 12. The seventh oil port and the eighth oil port of the diverter and collector device are connected to the two ends of the shuttle valve 14, the seventh oil port of the diverter and collector device is also connected to the second oil port of the flushing valve 13, the eighth oil port of the diverter and collector device is also connected to the first oil port of the flushing valve 13, the first oil port of the flushing valve 13 is also connected to the A port of the travel closed variable pump, the second oil port of the flushing valve 13 is also connected to the B port of the travel closed variable pump, the third oil port of the flushing valve 13 is connected to the return oil port T of the hydraulic oil tank through the overflow valve 17; the control valve is connected to the control ports of the first hydraulic control valve 11 and the second hydraulic control valve 12 and the ninth oil port of the diverter and collector device.

[0030] In a specific embodiment of the present invention, the flow diverter and collector device includes a first flow diverter and collector valve 5, a second flow diverter and collector valve 7, a third flow diverter and collector valve 9, a third hydraulic control valve 6, a fourth hydraulic control valve 8 and a fifth hydraulic control valve 10; the first oil diverter port of the first flow diverter and collector valve 5 is connected to the second oil diverter port of the first flow diverter and collector valve 5 through a first damper, the first oil diverter port of the first flow diverter and collector valve 5 is also connected to the first oil port of the third hydraulic control valve 6 through a second damper, and the second oil diverter port of the first flow diverter and collector valve 5 is connected to the second oil port of the third hydraulic control valve 6; the first oil diverter port of the second flow diverter and collector valve 7 is connected to the The third damper is connected to the second oil distribution port of the second diverter and collecting valve 7, and the first oil distribution port of the second diverter and collecting valve 7 is also connected to the first oil port of the fourth hydraulic control valve 8 through the fourth damper, and the second oil distribution port of the second diverter and collecting valve 7 is connected to the second oil port of the fourth hydraulic control valve 8; the first oil distribution port of the third diverter and collecting valve 9 is connected to the second oil distribution port of the third diverter and collecting valve 9 through the fifth damper, and the first oil distribution port of the third diverter and collecting valve 9 is also connected to the first oil port of the fifth hydraulic control valve 10 through the sixth damper, and the second oil distribution port of the third diverter and collecting valve 9 is connected to the second oil port of the fifth hydraulic control valve 10.

[0031] The first oil distribution port of the first diverter and collecting valve 5 is the first oil port of the diverter and collecting device, the first oil distribution port of the second diverter and collecting valve 7 is the second oil port of the diverter and collecting device, the second oil distribution port of the first diverter and collecting valve 5 is the third oil port of the diverter and collecting device, the second oil distribution port of the second diverter and collecting valve 7 is the fourth oil port of the diverter and collecting device, the first oil distribution port of the third diverter and collecting valve 9 is the fifth oil port of the diverter and collecting device, the second oil distribution port of the third diverter and collecting valve 9 is the sixth oil port of the diverter and collecting device, the oil collecting ports of the first diverter and collecting valve 5 and the third diverter and collecting valve 9 are the seventh oil port of the diverter and collecting device, the oil collecting port of the second diverter and collecting valve 7 is the eighth oil port of the diverter and collecting device, and the control ports of the third hydraulic control valve 6, the fourth hydraulic control valve 8 and the fifth hydraulic control valve 10 are the ninth oil port of the diverter and collecting device.

[0032] like Figure 2 As shown, when each motor moves forward (i.e., the aerial work platform moves forward), hydraulic oil enters from port A of the travel closed variable pump and returns from port B of the travel closed variable pump: the hydraulic oil flows into the oil collecting port of the second diverter and collector valve 7, flows into port A of the left rear travel motor 1 through the first oil diverter and collector valve 7, flows out from port B of the left rear travel motor 1, and flows back to port B of the travel closed variable pump through the first oil diverter and collector valve 5; the hydraulic oil flows into port A of the left front travel motor 2 through the second oil diverter and collector valve 7 through the first hydraulic control valve 11, and flows out from port A of the left front travel motor 2. The hydraulic oil flows back to the B port of the travel closed variable pump through the second oil distribution port and the oil collection port of the first diverter and collector valve 5. The hydraulic oil also flows through the first oil distribution port of the second diverter and collector valve 7, through the second hydraulic control valve 12, into the B port of the right front travel motor 4, flows out from the A port of the right front travel motor 4, and flows back to the B port of the travel closed variable pump through the second oil distribution port and the oil collection port of the third diverter and collector valve 9. The hydraulic oil also flows through the second oil distribution port of the second diverter and collector valve 7 into the B port of the right rear travel motor 3, flows out from the A port of the right rear travel motor 3, and flows back to the B port of the travel closed variable pump through the first oil distribution port and the oil collection port of the third diverter and collector valve 9. When each motor moves backward (i.e., the aerial work platform moves backward), the hydraulic oil enters from the B port of the travel closed variable pump and returns from the A port of the travel closed variable pump. The hydraulic oil flow direction is opposite to that when the motor moves forward.

[0033] When each motor is running at low speed (i.e., the aerial work platform is running at low speed), there is no pilot control oil at port C1, the third hydraulic control valve 6, the fourth hydraulic control valve 8 and the fifth hydraulic control valve 10 are in the disconnected state, and the first hydraulic control valve 11 and the second hydraulic control valve 12 are in the throttling state. The first hydraulic control valve 11 and the second hydraulic control valve 12 can pass the flow that meets the low-speed running of the motor without affecting normal running; when one or two front wheels slip or are suspended in the air, the throttling state of the first hydraulic control valve 11 and the second hydraulic control valve 12 can suppress the flow that should be allocated to the remaining tire motors from flowing to the slipping or suspended tire motors, thereby solving the problem of the whole vehicle not moving due to front wheel slippage or idling.

[0034] When each motor is running at high speed (i.e., the aerial work platform is running at high speed), there is pilot control oil at port C1, the third hydraulic control valve 6, the fourth hydraulic control valve 8 and the fifth hydraulic control valve 10 are in the normally open state, and the first hydraulic control valve 11 and the second hydraulic control valve 12 are in the normally open state. This state can pass the flow rate that meets the high-speed running of the motor without affecting normal running.

[0035] The present invention adds a hydraulic control valve with a throttling function to the oil channels of the left and right front wheels respectively, which limits the flow input to the left front travel motor 2 and the right front travel motor 4 during low-speed travel, avoiding the hydraulic oil that drives the entire vehicle to move doing useless work through the idling motors due to the front wheels slipping or hanging in the air, and allows part of the flow to flow from the left front travel motor 2 and the right front travel motor 4 (the high-pressure side formed by throttling the front wheel oil channels) to the left rear travel motor 1 and the right rear travel motor 3 on the low-pressure side, thereby realizing the movement of the entire vehicle under abnormal conditions.

[0036] In a specific embodiment of the present invention, the flow diverter and collector device further includes a first one-way valve 15 and a second one-way valve 16; the first oil diverter port of the flow diverter and collector valve is connected to the second oil diverter port of the flow diverter and collector valve via the first one-way valve 15 and the second one-way valve 16; the first one-way valve 15 and the second one-way valve 16 are connected to the oil replenishment pump integrated in the travel closed variable pump; wherein the flow diverter and collector valves refer to the first flow diverter and collector valve 5, the second flow diverter and collector valve 7, and the third flow diverter and collector valve 9. The travel closed variable pump is integrated with an oil replenishment pump, and hydraulic oil flows out of the oil replenishment pump, passes through the T1 port, and is replenished to the first oil diverter port and the second oil diverter port of each flow diverter and collector valve respectively through the first one-way valve 15 and the second one-way valve 16.

[0037] In a specific embodiment of the present invention, the third oil port of the flushing valve 13 is connected to the overflow valve 17 through the seventh damper, and the flushing flow of the hydraulic oil of the walking action is adjusted by the seventh damper.

[0038] In a specific embodiment of the present invention, the left front travel motor 2, the left rear travel motor 1, the right front travel motor 4 and the right rear travel motor 3 are all equipped with a variable displacement plunger 18. The variable displacement plunger 18 of the left front travel motor 2, the variable displacement plunger 18 of the right front travel motor 4, the variable displacement plunger 18 of the left rear travel motor 1 and the variable displacement plunger 18 of the right rear travel motor 3 are interconnected to maintain the required output speed and torque.

[0039] like Figure 1 As shown, in this embodiment, the control valve is a solenoid valve 20, which is also connected to the shuttle valve 14 and the hydraulic oil tank through the pressure reducing valve 19. When the solenoid valve 20 is energized, it controls the travel motors to run at high speed, and the hydraulic control valve 19 is in a normally open state. When the solenoid valve 20 is de-energized, the travel motors run at low speed, and the hydraulic control valve 19 is in a throttling state.

[0040] In a specific embodiment of the present invention, pressure measuring points MA / MB are provided at the first oil port and the second oil port of the flushing valve 13 .

[0041] The above disclosure is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, and they should all be covered by the scope of protection of the present invention.

Claims

1. A four-wheel drive travel control system, characterized by: The control system includes a flow diverter and collector device, a first hydraulically controlled valve with a throttling function, a second hydraulically controlled valve with a throttling function, a flushing valve, a shuttle valve and a control valve; the first oil port and the second oil port of the flow diverter and collector device are respectively connected to the B port and the A port of the left rear travel motor, the third oil port of the flow diverter and collector device is connected to the B port of the left front travel motor, the fourth oil port of the flow diverter and collector device is connected to the A port of the left front travel motor through the first hydraulically controlled valve, the fifth oil port of the flow diverter and collector device is connected to the A port of the right rear travel motor, the fourth oil port of the flow diverter and collector device is also connected to the B port of the right rear travel motor, the sixth oil port of the flow diverter and collector device is connected to the A port of the right front travel motor, and the second oil port of the flow diverter and collector device is also connected to the B port of the right front travel motor through the second hydraulically controlled valve; The seventh oil port and the eighth oil port of the flow dividing and collecting device are respectively connected to the two ends of the shuttle valve, the seventh oil port of the flow dividing and collecting device is also connected to the second oil port of the flushing valve, the eighth oil port of the flow dividing and collecting device is also connected to the first oil port of the flushing valve, the first oil port of the flushing valve is also connected to the A port of the travel closed variable pump, the second oil port of the flushing valve is also connected to the B port of the travel closed variable pump, and the third oil port of the flushing valve is connected to the hydraulic oil tank through the overflow valve; the control valve is connected to the control ports of the first and second hydraulic control valves and the ninth oil port of the flow dividing and collecting device; The flow dividing and collecting device includes a first flow dividing and collecting valve, a second flow dividing and collecting valve, a third flow dividing and collecting valve, a third hydraulic control valve, a fourth hydraulic control valve and a fifth hydraulic control valve; The first oil distribution port of the first flow dividing and combining valve is communicated with the second oil distribution port of the first flow dividing and combining valve via a first damper. The first oil distribution port of the first flow dividing and combining valve is also communicated with the first oil distribution port of the third hydraulic control valve via a second damper. The second oil distribution port of the first flow dividing and combining valve is communicated with the second oil distribution port of the third hydraulic control valve. The first oil branch port of the second flow dividing and combining valve is communicated with the second oil branch port of the second flow dividing and combining valve via a third damper. The first oil branch port of the second flow dividing and combining valve is further communicated with the first oil port of the fourth hydraulic control valve via a fourth damper. The second oil branch port of the second flow dividing and combining valve is communicated with the second oil port of the fourth hydraulic control valve. The first oil branch port of the third flow diverter and collector valve is connected to the second oil branch port of the third flow diverter and collector valve through a fifth damper. The first oil branch port of the third flow diverter and collector valve is also connected to the first oil port of the fifth hydraulic control valve through a sixth damper. The second oil branch port of the third flow diverter and collector valve is connected to the second oil port of the fifth hydraulic control valve. The first oil distribution port of the first diverter and collector valve is the first oil distribution port of the diverter and collector device, the first oil distribution port of the second diverter and collector valve is the second oil distribution port of the diverter and collector device, the second oil distribution port of the first diverter and collector valve is the third oil distribution port of the diverter and collector device, the second oil distribution port of the second diverter and collector valve is the fourth oil distribution port of the diverter and collector device, the first oil distribution port of the third diverter and collector valve is the fifth oil distribution port of the diverter and collector device, the second oil distribution port of the third diverter and collector valve is the sixth oil distribution port of the diverter and collector device, the oil collection ports of the first diverter and collector valve and the third diverter and collector valve are the seventh oil distribution port of the diverter and collector device, the oil collection port of the second diverter and collector valve is the eighth oil distribution port of the diverter and collector device, and the control ports of the third hydraulic control valve, the fourth hydraulic control valve and the fifth hydraulic control valve are the ninth oil distribution port of the diverter and collector device; The left front travel motor, the left rear travel motor, the right front travel motor and the right rear travel motor are all equipped with variable displacement plungers, and the variable displacement plungers of the left front travel motor, the variable displacement plungers of the right front travel motor, the variable displacement plungers of the left rear travel motor and the variable displacement plungers of the right rear travel motor are connected to each other.

2. The four-wheel drive travel control system according to claim 1, characterized in that: The flow dividing and collecting device further includes a first one-way valve and a second one-way valve; the first oil distribution port of the flow dividing and collecting valve is connected to the second oil distribution port of the flow dividing and collecting valve through the first one-way valve and the second one-way valve; the first one-way valve and the second one-way valve are connected to the oil charging pump integrated in the traveling closed variable displacement pump; The flow diverter and collector valves include a first flow diverter and collector valve, a second flow diverter and collector valve, and a third flow diverter and collector valve.

3. The four-wheel drive control system according to claim 1, characterized in that: The third oil port of the flushing valve is communicated with the overflow valve through the seventh damper.

4. The four-wheel drive control system according to claim 1, characterized in that: The control valve is a solenoid valve, which is also connected to the shuttle valve and the hydraulic oil tank through a pressure reducing valve.

5. The four-wheel drive control system according to any one of claims 1 to 4, characterized in that: Pressure measuring points are provided at the first oil port and the second oil port of the flush valve.

6. An aerial work platform, characterized by: The aerial work platform adopts the four-wheel drive travel control system according to any one of claims 1 to 5 for travel drive control.

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