Hydraulic travel control system, control method, and aerial work vehicle

Abstract

This invention discloses a hydraulic walking control system, control method, and aerial work vehicle. The system includes a walking pump, a first diverting and combining valve, a second diverting and combining valve, and various walking motors. Port A of the walking pump is connected to the third port of the first and second diverting and combining valves. Port B of the walking pump is connected to the B ports of the left front walking motor, the left rear walking motor, the right front walking motor, and the right rear walking motor. The fourth port of the first diverting and combining valve is connected to the A port of the left front walking motor, and the second port of the first diverting and combining valve is connected to the A port of the left rear walking motor. The fourth port of the second diverting and combining valve is connected to the B port of the right front walking motor, and the second port of the second diverting and combining valve is connected to the B port of the right rear walking motor. This invention avoids the problem of slippage during walking causing changes in flow rate and pressure, which in turn affects the walking performance.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic control technology, and particularly relates to a hydraulic walking control system, control method and aerial work vehicle. Background Technology

[0002] The existing travel control system used in aerial work platforms typically includes a flow divider valve, a front axle, a rear axle, and travel motors. Three flow divider valves distribute hydraulic fluid to the front and rear axles, and then to the four travel motors. Specific control methods include: diverting fluid to the two front and two rear travel motors via the flow divider valves, or diagonally diverting fluid to the right front motor and left rear motor, or the left and right rear motors. Throttling damping control channels are used at both ends of each flow divider valve to regulate the different flow demands of each travel motor due to uneven ground conditions, ensuring consistent travel speed across all motors and preventing tire dragging. The system also includes overflow valves, flushing valves, and various reversing throttle valves for climbing slopes and traversing flat ground.

[0003] The disadvantages of the two hydraulic travel control methods mentioned above are as follows: When climbing a slope, if the front wheel slips, the load pressure of the front wheel travel motor will be significantly reduced. When the pressure difference between the front wheel travel motor and the rear wheel travel motor is large, the oil will flow to the low-pressure side through the throttling damper, causing the front wheel to spin freely, which greatly reduces the climbing effect, resulting in a lack of climbing ability and, in severe cases, an inability to climb. When traveling on flat ground, due to the influence of the throttling damper and the reversing throttle valve, there will be phenomena such as pressure buildup and speed drop when traveling and turning. Furthermore, when reversing, it is also affected by the throttling damper and the reversing throttle valve.

[0004] Meanwhile, the large number of throttling dampers, reversing throttle valves, and relief valves increases the pressure loss of the system, thereby increasing energy consumption and operating costs. In addition, both of these hydraulic walking control schemes are relatively expensive. Summary of the Invention

[0005] The purpose of this invention is to provide a hydraulic walking control system, control method, and aerial work vehicle to solve at least one of the following problems: traditional control methods easily cause the front wheels to spin freely when climbing slopes, affecting the climbing effect; and a large number of valve cores increase energy consumption and system cost.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution: a hydraulic walking control system, comprising a walking pump, a first diversion and combination valve, a second diversion and combination valve, a left front walking motor, a left rear walking motor, a right front walking motor, and a right rear walking motor; the A port of the walking pump is connected to the third port of the first diversion and combination valve and the third port of the second diversion and combination valve; the B port of the walking pump is connected to the B port of the left front walking motor, the B port of the left rear walking motor, the A port of the right front walking motor, and the A port of the right rear walking motor; the fourth port of the first diversion and combination valve is connected to the A port of the left front walking motor; the second port of the first diversion and combination valve is connected to the A port of the left rear walking motor; the fourth port of the second diversion and combination valve is connected to the B port of the right front walking motor; and the second port of the second diversion and combination valve is connected to the B port of the right rear walking motor.

[0007] Furthermore, the system also includes a shuttle valve and a flushing valve. The two ends of the shuttle valve are connected to ports A and B of the travel pump, respectively. The first and second ports of the flushing valve are connected to ports A and B of the travel pump, respectively. The third port of the flushing valve is connected to the hydraulic oil tank through a return port.

[0008] Furthermore, a first throttling element is provided on the pipeline between the third port of the flushing valve and the return oil port.

[0009] Furthermore, the second port of the first diverter and combiner valve is also connected to the fourth port of the first diverter and combiner valve through a second throttling element; the second port of the second diverter and combiner valve is also connected to the fourth port of the second diverter and combiner valve through a third throttling element.

[0010] Furthermore, the second port of the first diverter valve is also connected to the fourth port of the first diverter valve through a first check valve and a second check valve; the second port of the second diverter valve is also connected to the fourth port of the second diverter valve through a third check valve and a fourth check valve.

[0011] The connection points of the first check valve and the second check valve, and the connection points of the third check valve and the fourth check valve, are all connected to the oil replenishment pump integrated in the travel pump through the oil replenishment port.

[0012] Furthermore, the system also includes a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is used to detect the pressure at port A of the travel pump, and the second pressure sensor is used to detect the pressure at port B of the travel pump.

[0013] Based on the same concept, the present invention provides an aerial work vehicle, the vehicle including the hydraulic travel control system described above.

[0014] Based on the same concept, the present invention provides a hydraulic walking control method, applied to the hydraulic walking control system described above, wherein the control method includes:

[0015] When moving forward, the oil flows from port A of the travel pump into the third port of the first diversion and combiner valve and the third port of the second diversion and combiner valve; then, through the second and fourth ports of the first diversion and combiner valve, the oil is proportionally diverted to port A of the left rear travel motor and port A of the left front travel motor, respectively; through the second and fourth ports of the second diversion and combiner valve, the oil is proportionally diverted to port B of the right rear travel motor and port B of the right front travel motor, respectively; after passing through the left rear travel motor, left front travel motor, right rear travel motor and right front travel motor, the oil flows back to port B of the travel pump.

[0016] When reversing, the oil flows directly from port B of the travel pump into port B of the left rear travel motor, port B of the left front travel motor, port A of the right rear travel motor, and port A of the right front travel motor. After passing through the left rear travel motor, the oil flows into the second port of the first diversion and combination valve. After passing through the left front travel motor, the oil flows into the fourth port of the first diversion and combination valve. After passing through the right rear travel motor, the oil flows into the second port of the second diversion and combination valve. After passing through the right front travel motor, the oil flows into the fourth port of the second diversion and combination valve. Finally, the oil flows back to port A of the travel pump through the first and second diversion and combination valves.

[0017] Beneficial effects

[0018] Compared with the prior art, the advantages of the present invention are as follows:

[0019] This invention uses a first diversion and combiner valve to control the flow of the left-side travel motor (including the left front travel motor and the left rear travel motor), and a second diversion and combiner valve to control the flow of the right-side travel motor (including the right front travel motor and the right rear travel motor). In other words, this invention employs a same-side diversion control method. During travel (including climbing), because of this same-side diversion control, even if one tire slips, it will not affect the flow and pressure of the other tire. Therefore, it will not affect the climbing performance and avoids the problem of changes in flow and pressure due to slippage during travel, which in turn affects the travel (including climbing) performance.

[0020] This invention uses only the first and second diversion and combination valves when reversing, which greatly reduces the cost of use; it eliminates excessive damping and valve groups, which greatly reduces pressure loss, lowers the cost of system components, and avoids the problems of pressure buildup and speed drop caused by inconsistent flow due to turning when traveling at high and low speeds on flat ground. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the hydraulic walking control system in an embodiment of the present invention;

[0023] Figure 2 This is a diagram showing the oil flow direction of the hydraulic walking control system during forward movement in an embodiment of the present invention;

[0024] Figure 3 This is a diagram showing the oil flow direction when the hydraulic walking control system moves backward in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached diagram: 1-First pressure sensor, 2-Shuttle valve, 3-Flush valve, 4-Second pressure sensor, 5-Left front travel motor, 6-Right front travel motor, 7-Second diverter / combiner valve, 8-Third check valve, 9-Fourth check valve, 10-Right rear travel motor, 11-First check valve, 12-Left rear travel motor, 13-First diverter / combiner valve, 14-Second check valve, MA-Measuring point of the first pressure sensor, MB-Measuring point of the second pressure sensor, T-Return port, M-Reserved port, T1-Replenishment port, LFB-B port of the left front travel motor, LFA-A port of the left front travel motor, LRB-B port of the left rear travel motor, LRA-A port of the left rear travel motor, RFA-A port of the right front travel motor, RFB-B port of the right front travel motor, RRA-A port of the right rear travel motor, RRB-B port of the right rear travel motor. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0028] like Figure 1As shown, the hydraulic walking control system provided in this embodiment of the invention includes a walking pump, a first diversion and combination valve 13, a second diversion and combination valve 7, a left front walking motor 5, a left rear walking motor 12, a right front walking motor 6, and a right rear walking motor 10; the A port of the walking pump is connected to the third port of the first diversion and combination valve 13 and the third port of the second diversion and combination valve 7, and the B port of the walking pump is connected to the B port of the left front walking motor 5, the B port of the left rear walking motor 12, the A port of the right front walking motor 6, and the A port of the right rear walking motor 10; the fourth port of the first diversion and combination valve 13 is connected to the A port of the left front walking motor 5, and the second port of the first diversion and combination valve 13 is connected to the A port of the left rear walking motor 12; the fourth port of the second diversion and combination valve 7 is connected to the B port of the right front walking motor 6, and the second port of the second diversion and combination valve 7 is connected to the B port of the right rear walking motor 10.

[0029] like Figure 2 As shown, when moving forward, the oil flows from port A of the travel pump into the third port of the first diversion and manifold valve 13 and the third port of the second diversion and manifold valve 7; then, through the second and fourth ports of the first diversion and manifold valve 13, the oil is proportionally diverted to port A of the left rear travel motor 12 and port A of the left front travel motor 5, respectively; through the second and fourth ports of the second diversion and manifold valve 7, the oil is proportionally diverted to port B of the right rear travel motor 10 and port B of the right front travel motor 6, respectively; after passing through the left rear travel motor 12, the left front travel motor 5, the right rear travel motor 10 and the right front travel motor 6, the oil flows back to port B of the travel pump.

[0030] like Figure 3 As shown, when reversing, the oil flows directly from port B of the travel pump into port B of the left rear travel motor 12, port B of the left front travel motor 5, port A of the right rear travel motor 10, and port A of the right front travel motor 6; after passing through the left rear travel motor 12, the oil flows into the second port of the first diversion and combination valve 13; after passing through the left front travel motor 5, the oil flows into the fourth port of the first diversion and combination valve 13; after passing through the right rear travel motor 10, the oil flows into the second port of the second diversion and combination valve 7; after passing through the right front travel motor 6, the oil flows into the fourth port of the second diversion and combination valve 7; finally, the oil flows back to port A of the travel pump through the first diversion and combination valve 13 and the second diversion and combination valve 7.

[0031] This invention employs a same-side flow split control method. Specifically, the first flow splitter valve 13 controls the flow to the left-side travel motors (including the left front travel motor 5 and the left rear travel motor 12), and the second flow splitter valve 7 controls the flow to the right-side travel motors (including the right front travel motor 6 and the right rear travel motor 10). During travel (including climbing), even if one tire slips, it will not affect the flow and pressure of the other tire, thus ensuring uninterrupted travel and climbing performance. When reversing, the fluid flows directly from the travel pump to the travel motors through the travel control valve, bypassing other damping and valve groups, significantly reducing operating costs. This invention eliminates overflow valves, directional valves, throttle valves, and other valve groups, greatly reducing losses, improving efficiency, and lowering system costs. The invention uses fewer valve groups, preventing pressure buildup and speed loss during vehicle turns, resulting in lower overall pressure.

[0032] This invention abandons the traditional control method of using three diversion and combiner valves to form a diagonal flow or front and rear wheel flow, and changes the control method of the hydraulic walking system. It adopts two diversion and combiner valves for same-side flow control, which avoids the problem of flow and pressure changes caused by slippage during walking, thus affecting the walking (including climbing) effect.

[0033] In a specific embodiment of the present invention, the walking control system further includes a shuttle valve 2 and a flushing valve 3. The two ends of the shuttle valve 2 are connected to the A port and the B port of the walking pump, respectively. The first port and the second port of the flushing valve 3 are connected to the A port and the B port of the walking pump, respectively. The third port of the flushing valve 3 is connected to the hydraulic oil tank through the return oil port T.

[0034] In a specific embodiment of the present invention, a first throttling element is also provided on the pipeline between the third port of the flushing valve 3 and the return oil port T. In this embodiment, the first throttling element is a damper with a diameter of 2.0, which is used to adjust the flushing flow rate of the oil during the walking motion.

[0035] In a specific embodiment of the present invention, the second port of the first diversion and combination valve 13 is also connected to the fourth port of the first diversion and combination valve 13 through a second throttling element; the second port of the second diversion and combination valve 7 is also connected to the fourth port of the second diversion and combination valve 7 through a third throttling element.

[0036] In this embodiment, both the second and third throttling elements have two dampers with diameters of 0.6 and 2.5 mm respectively. These dampers control the connection of the oil passages. When uneven ground causes different flow requirements for each travel motor, the 0.6 mm diameter damper is used for adjustment, ensuring that the travel speed of each motor remains consistent even with varying flow requirements, preventing tire dragging.

[0037] In a specific embodiment of the present invention, the second port of the first diversion and combination valve 13 is also connected to the fourth port of the first diversion and combination valve 13 through the first one-way valve 11 and the second one-way valve 14; the second port of the second diversion and combination valve 7 is also connected to the fourth port of the second diversion and combination valve 7 through the third one-way valve 8 and the fourth one-way valve 9; the connection point between the first one-way valve 11 and the second one-way valve 14, and the connection point between the third one-way valve 8 and the fourth one-way valve 9 are all connected to the replenishment pump integrated in the travel pump through the replenishment port T1.

[0038] When the road surface is uneven or the flow demand is high, the oil in the replenishing pump replenishes the left rear travel motor A port and the left front travel motor A port through the first check valve 11 and the second check valve 14 respectively; the oil in the replenishing pump replenishes the right rear travel motor B port and the right front travel motor B port through the third check valve 8 and the fourth check valve 9 respectively.

[0039] In a specific embodiment of the present invention, the walking control system further includes a first pressure sensor 1 and a second pressure sensor 4. The first pressure sensor 1 is used to detect the pressure at port A of the walking pump, and the second pressure sensor 4 is used to detect the pressure at port B of the walking pump.

[0040] The system's operating status is determined by the pressure values ​​detected by the first pressure sensor 1 and the second pressure sensor 4, allowing for timely detection of any malfunctions during use.

[0041] Comparative testing of the walking control system of the present invention with the walking control scheme currently used in existing models shows that the walking control system of the present invention has low pressure, return oil back pressure and pressure loss, and no pressure build-up or speed drop occurs at high and low speeds or when walking with steering, and the climbing effect is good.

[0042] This invention provides a hydraulic walking control method, applied to the hydraulic walking control system in this application embodiment. The control method includes:

[0043] like Figure 2 As shown, when moving forward, the oil flows from port A of the travel pump into the third port of the first diversion and manifold valve 13 and the third port of the second diversion and manifold valve 7; then, through the second and fourth ports of the first diversion and manifold valve 13, the oil is proportionally diverted to port A of the left rear travel motor 12 and port A of the left front travel motor 5, respectively; through the second and fourth ports of the second diversion and manifold valve 7, the oil is proportionally diverted to port B of the right rear travel motor 10 and port B of the right front travel motor 6, respectively; after passing through the left rear travel motor 12, the left front travel motor 5, the right rear travel motor 10 and the right front travel motor 6, the oil flows back to port B of the travel pump.

[0044] like Figure 3As shown, when reversing, the oil flows directly from port B of the travel pump into port B of the left rear travel motor 12, port B of the left front travel motor 5, port A of the right rear travel motor 10, and port A of the right front travel motor 6; after passing through the left rear travel motor 12, the oil flows into the second port of the first diversion and combination valve 13; after passing through the left front travel motor 5, the oil flows into the fourth port of the first diversion and combination valve 13; after passing through the right rear travel motor 10, the oil flows into the second port of the second diversion and combination valve 7; after passing through the right front travel motor 6, the oil flows into the fourth port of the second diversion and combination valve 7; finally, the oil flows back to port A of the travel pump through the first diversion and combination valve 13 and the second diversion and combination valve 7.

[0045] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulic walking control system, characterized in that, The system includes a single travel pump, a first diversion and combiner valve, a second diversion and combiner valve, a left front travel motor, a left rear travel motor, a right front travel motor, and a right rear travel motor. Port A of the single travel pump is connected to the third port of the first diversion and combiner valve and the third port of the second diversion and combiner valve. Port B of the single travel pump is connected to the B port of the left front travel motor, the B port of the left rear travel motor, the A port of the right front travel motor, and the A port of the right rear travel motor. Port 4 of the first diversion and combiner valve is connected to port A of the left front travel motor, and port 2 of the first diversion and combiner valve is connected to port A of the left rear travel motor. Port 4 of the second diversion and combiner valve is connected to port B of the right front travel motor, and port 2 of the second diversion and combiner valve is connected to port B of the right rear travel motor. The system also includes a shuttle valve and a flushing valve. The two ends of the shuttle valve are connected to port A and port B of the single walking pump, respectively. The first and second ports of the flushing valve are connected to port A and port B of the single walking pump, respectively. The third port of the flushing valve is connected to the hydraulic oil tank through the return port. Furthermore, a first throttling element is provided on the pipeline between the third port of the flushing valve and the return port; the second port of the first diverting and combining valve is also connected to the fourth port of the first diverting and combining valve through the second throttling element; the second port of the second diverting and combining valve is also connected to the fourth port of the second diverting and combining valve through the third throttling element.

2. The hydraulic walking control system according to claim 1, characterized in that, The second port of the first diverting and combining valve is also connected to the fourth port of the first diverting and combining valve through a first check valve and a second check valve; the second port of the second diverting and combining valve is also connected to the fourth port of the second diverting and combining valve through a third check valve and a fourth check valve. The connection points of the first check valve and the second check valve, and the connection points of the third check valve and the fourth check valve, are all connected to the replenishment pump integrated in the single travel pump through the replenishment port.

3. The hydraulic walking control system according to claim 1 or 2, characterized in that, The system also includes a first pressure sensor and a second pressure sensor. The first pressure sensor is used to detect the pressure at port A of the travel pump, and the second pressure sensor is used to detect the pressure at port B of the travel pump.

4. An aerial work platform vehicle, characterized in that, The vehicle includes a hydraulic travel control system as described in any one of claims 1 to 3.

5. A hydraulic walking control method, characterized in that, The control method, applied to the hydraulic walking control system as described in any one of claims 1 to 3, comprises: When moving forward, the oil flows from port A of the travel pump into the third port of the first diversion and combiner valve and the third port of the second diversion and combiner valve; then, through the second and fourth ports of the first diversion and combiner valve, the oil is proportionally diverted to port A of the left rear travel motor and port A of the left front travel motor, respectively; through the second and fourth ports of the second diversion and combiner valve, the oil is proportionally diverted to port B of the right rear travel motor and port B of the right front travel motor, respectively; after passing through the left rear travel motor, left front travel motor, right rear travel motor and right front travel motor, the oil flows back to port B of the travel pump. When reversing, the oil flows directly from port B of the travel pump into port B of the left rear travel motor, port B of the left front travel motor, port A of the right rear travel motor, and port A of the right front travel motor. After passing through the left rear travel motor, the oil flows into the second port of the first diversion and combination valve. After passing through the left front travel motor, the oil flows into the fourth port of the first diversion and combination valve. After passing through the right rear travel motor, the oil flows into the second port of the second diversion and combination valve. After passing through the right front travel motor, the oil flows into the fourth port of the second diversion and combination valve. Finally, the oil flows back to port A of the travel pump through the first and second diversion and combination valves.

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