Multi-pump multi-motor hydraulic drive system for an all-terrain vehicle and control method

Abstract

The application discloses a kind of multi-pump multi-motor hydraulic drive system and control method for all-terrain vehicle, including pump, two or more than two pumps are connected into shunt valve group in parallel, the pressure oil line of each pump is installed check valve, each shunt valve in shunt valve group is connected with each motor respectively, the weight of each vehicle body is detected by sensor, the flow of each shunt valve in shunt valve group is adjusted, and the thrust-to-weight ratio of each motor is guaranteed.The output oil pressure of multiple pumps is integrated into an input in the present hydraulic system, so that the load of each pump can be kept consistent, and the output oil pressure can be distributed according to the weight of each vehicle body, so that the thrust-to-weight ratio obtained by each vehicle body can be kept consistent.

Description

Technical Field

[0001] This invention relates to an all-terrain vehicle for water travel, and in particular a multi-pump, multi-motor device mounted on the front and rear of the vehicle. Background Technology

[0002] All-terrain vehicles are mainly used in my country's national defense construction and natural disaster emergency rescue. Relying on their efficient driving performance and all-terrain driving capabilities, they can travel on various complex off-road surfaces such as deserts, grasslands, and snowfields.

[0003] Current all-terrain vehicles are driven by four motors, consisting of left and right drive motors in the front and rear sections. To achieve optimal driving performance and avoid dragging (either the front vehicle pulling the rear vehicle or the rear vehicle pushing the front vehicle), it is necessary to ensure that the four motors achieve nearly identical speeds. The current synchronous control method uses one pump to control the left and right motors of one section, with two pumps controlling all four motors. A fixed displacement motor is then used to simultaneously provide equal speed and displacement control to the two pumps. This control method basically achieves optimal driving performance, but it has an inherent flaw: if one pump fails or the control malfunctions, dragging immediately occurs. In addition, the front and rear vehicles have different masses, but the torque distribution between them is the same, meaning the push-to-weight ratio is also inconsistent. This causes the pump and motor of the heavier section to be under constant high load, which is clearly an unreasonable mechanical operating state. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a hydraulic drive system that integrates the power of multiple pumps and rationally distributes it to each motor, addressing the issue of inconsistent loads on the drive motors and pumps on different parts of an all-terrain vehicle.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A multi-pump, multi-motor hydraulic drive system for all-terrain vehicles includes pumps, two or more pumps connected in parallel to a flow divider valve group, a check valve installed on the pressure oil line of each pump, and each flow divider valve in the flow divider valve group connected to each motor. The weight of each vehicle body is detected by a sensor, and the flow rate of each flow divider valve in the flow divider valve group is adjusted to ensure that the thrust-to-weight ratio of each motor is the same.

[0007] The multi-pump pump group 1 includes two or more adjustable bidirectional variable pumps. The pressure oil circuits of the adjustable bidirectional variable pumps in two directions are connected in parallel to the first diverter valve group 4 or the second diverter valve group 5. Each diverter valve in the first diverter valve group 4 and the second diverter valve group 5 is connected to a reversing valve 6. The reversing valve 6 is connected to a motor group 7. The motor group 7 integrates a quantitative diverter valve.

[0008] A motor speed sensor 12 and a motor displacement controller 11 are installed on each motor in motor group 7; a pump pressure sensor 9 and a pump displacement sensor 10 are installed on each adjustable bidirectional variable pump; a flow valve controller 13 is set to control the opening degree of each diverter valve in the diverter valve group; the motor speed sensor 12, the motor displacement controller 11, the pump pressure sensor 9, the pump displacement sensor 10, and the flow valve controller 13 are all connected to the central processing unit 14.

[0009] The pressure oil circuits in both directions of the multi-pump pump unit 1 are connected to the overflow oil circuit and a shuttle valve 2 is installed. The overflow oil circuit is connected to the safety overflow valve 3 via the shuttle valve 2.

[0010] The return oil valve port on the reversing valve 6 is connected to the oil tank 8 via the return oil circuit.

[0011] The central processing unit 14 first obtains the mass of each car body, calculates the total mass as m, and the total flow rate given by the system as Q, and obtains the thrust-to-weight ratio i = Q / m. Based on this thrust-to-weight ratio, the flow rate of the motor on each car body is calculated.

[0012] Let n be a parameter proportional to the vehicle speed. Calculate the motor displacement using the formula n = motor flow rate / motor displacement.

[0013] Adjust the values ​​of i and n according to different road conditions.

[0014] When driving on complex terrain with high resistance, increase the value of i and decrease the value of n; when driving on a smooth, straight highway with good road conditions, increase both the values ​​of i and n; when driving on snow, ice, or slippery surfaces, decrease both the values ​​of i and n; when the vehicle needs to drive in an energy-efficient manner, decrease the value of i and increase the value of n.

[0015] i-value adjustment: The central processing unit 14 first sets the instruction signal of i-value according to the command or automatic judgment, and then sends it to the pump displacement controller 10. The pump displacement controller adjusts the pump displacement to achieve the set target of i-value. The pump pressure sensor 9 feeds back the detected pump pressure signal to the central processing unit 14 at any time.

[0016] Adjustment of n value: The motor speed sensor 12 feeds back the motor speed to the central processing unit 14 in real time. The central processing unit 14 performs iterative calculations in the calculation model to obtain the control signal of the motor displacement, and then transmits the signal to the motor displacement controller 11 to complete the control of the motor displacement.

[0017] The beneficial effects of this invention are:

[0018] 1. This hydraulic system integrates the output oil pressure of multiple pumps into one input, which ensures that the load of each pump remains consistent. The output oil pressure is then distributed according to the weight of each vehicle body, so that the thrust-to-weight ratio of each vehicle body remains consistent.

[0019] 2. To facilitate control, this hydraulic control system provides two control values, i and n. The i value is proportional to the vehicle's thrust-to-weight ratio, and the n value is proportional to the vehicle's speed. When dealing with different road conditions and vehicle driving states, the n and i values ​​can be adjusted to provide the vehicle with more suitable power output. Attached Figure Description

[0020] Figure 1 This is the schematic diagram of the hydraulic system. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0022] Example 1:

[0023] This embodiment is a multi-pump, multi-motor hydraulic drive system for a dual-body all-terrain vehicle. The system mainly includes a multi-pump assembly 1, a shuttle valve 2, a safety relief valve 3, an independently adjustable diverter valve assembly 4, an independently adjustable diverter valve assembly 5, a directional valve 6, a motor assembly with an integrated diverter valve 7, an oil tank 8, a pump pressure sensor 9, a pump displacement controller 10, a motor displacement controller 11, a motor speed sensor 12, a flow valve controller 13, and a central processing unit 14.

[0024] The multi-pump assembly 1 includes two adjustable bidirectional variable pumps. The pressure oil circuits of the adjustable bidirectional variable pumps in both directions are connected in parallel to either the first diverter valve group 4 or the second diverter valve group 5. A check valve is installed on each pressure oil circuit. Each diverter valve in the first diverter valve group 4 and the second diverter valve group 5 is connected to a reversing valve 6. The reversing valve 6 is connected to a motor assembly 7. The motor assembly 7 includes two drive motors on each vehicle body, with two drive motors per vehicle body. A quantitative diverter valve is installed on the oil circuit between the two drive motors to ensure consistent flow rates between them. The pressure oil circuits in both directions of the multi-pump assembly 1 are connected to an overflow oil circuit and equipped with a shuttle valve 2. The overflow oil circuit is connected to a safety overflow valve 3 via the shuttle valve 2. The return oil port on the reversing valve 6 is connected to the oil tank 8 via a return oil circuit.

[0025] A motor speed sensor 12 and a motor displacement controller 11 are installed on each motor in motor group 7; a pump pressure sensor 9 and a pump displacement sensor 10 are installed on each adjustable bidirectional variable pump; a flow valve controller 13 is set to control the opening degree of each diverter valve in the diverter valve group; the motor speed sensor 12, the motor displacement controller 11, the pump pressure sensor 9, the pump displacement sensor 10, and the flow valve controller 13 are all connected to the central processing unit 14.

[0026] The control method is as follows: The central processing unit 14 first obtains the masses m1 and m2 of each car body, calculates the total mass as m = m1 + m2, and the total flow rate given by the system is Q, obtaining the thrust-to-weight ratio Q / m. Based on this thrust-to-weight ratio, the flow rate of the motor on each car body is calculated as Q1 / m1 = Q2 / m2 = Q / m = i. Let n be a parameter proportional to the vehicle speed, and calculate the motor displacement according to the formula n = motor flow rate / motor displacement. p1 and p2 represent the displacement of the motors on each vehicle body.

[0027] Adjust the values ​​of i and n according to different road conditions.

[0028] When the vehicle is traveling on complex terrain with high resistance, increase the value of i and decrease the value of n; when the vehicle is traveling on a smooth, straight highway with good road conditions, increase both the values ​​of i and n; when the vehicle is traveling on snow, ice, or slippery roads, decrease both the values ​​of i and n; when the vehicle needs to drive in an energy-efficient manner, decrease the value of i and increase the value of n.

[0029] i-value adjustment: The central processing unit 14 first sets the instruction signal of i-value according to the command or automatic judgment, and then sends it to the pump displacement controller 10. The pump displacement controller adjusts the pump displacement to achieve the set target of i-value. The pump pressure sensor 9 feeds back the detected pump pressure signal to the central processing unit 14 at any time.

[0030] Adjustment of n value: The motor speed sensor 12 feeds back the motor speed to the central processing unit 14 in real time. The central processing unit 14 performs iterative calculations in the calculation model to obtain the control signal of the motor displacement, and then transmits the signal to the motor displacement controller 11 to complete the control of the motor displacement.

[0031] Example 2:

[0032] This invention relates to a multi-pump, multi-motor hydraulic drive system for multi-body all-terrain vehicles. The system mainly includes a multi-pump assembly 1, a shuttle valve 2, a safety relief valve 3, an independently adjustable flow divider valve assembly 4, an independently adjustable flow divider valve assembly 5, a directional valve 6, a motor assembly with integrated flow divider valves 7, an oil tank 8, a pump pressure sensor 9, a pump displacement controller 10, a motor displacement controller 11, a motor speed sensor 12, a flow valve controller 13, and a central processing unit 14. Figure 1 As shown.

[0033] Combination Figure 1 Explanation:

[0034] The basic working principle of the hydraulic circuit: The multi-pump assembly 1 is an adjustable bidirectional variable pump with equal-position linkage regulation. When the pump assembly 1 is working, according to the direction of the pump port, the pressurized oil flows from the high-pressure port of the pump assembly into the oil circuit, reaching the flow divider valve assembly 4 (or flow divider valve assembly 5) and the shuttle valve 2 respectively. The outlet of the shuttle valve is connected to the safety relief valve 3. When the system pressure is higher than the adjustment pressure of the safety relief valve, it overflows. The high-pressure oil reaching the flow divider valve assembly 4 (or flow divider valve assembly 5) reaches the inlet of the directional valve 6 through the flow divider channel of the flow divider valve assembly 4 (or flow divider valve assembly 5). When the directional valve 6 is in the initial state, the oil circuit is closed. When the directional valve 6 is in the working state, the high-pressure oil reaches the motor assembly 7 that drives the travel through the directional valve 6. The motor assembly 7 integrates a quantitative flow divider valve to ensure that the left and right travel motors of each car body receive equal flow.

[0035] Because the overall mass of each section of a multi-body all-terrain vehicle is different, such as the section with an integrated power system being heavier and the other sections being lighter when unloaded, in order to ensure that each section obtains the same thrust-to-weight ratio, (not within the scope of this invention: the load sensor sends the load signal of each section to the central processor, and obtains the approximate total mass of each section through preset information), the central processor 14 first obtains the mass of each section, assuming the masses of different sections are m1, m2, and m3, and calculates the total mass as m. Then, control calculations are performed, and the calculated and distributed control electrical signals are fed back to the flow valve controller 13 and the motor displacement controller 11. The flow controller 13 actively adjusts the flow capacity of each flow channel in the diversion valve group 4 (or diversion valve group 5) according to the feedback signal, so that the flow rates of different outlets of the diversion valve group 4 (or diversion valve group 5) are Q1, Q2, and Q3, and the total flow rate given by the system is Q (variable). The motor displacement controller actively adjusts the displacement of the motor group 7 according to the feedback signal, assuming the displacement obtained by a single motor in each section is p1, p2, and p3. The central processing unit 14 performs data calculations during signal processing. The calculation model is as follows:

[0036]

[0037]

[0038] Q1 + Q2 + Q3 = Q (3)

[0039] m1 + m2 + m3 = m (4)

[0040] The value of i is proportional to the vehicle's thrust-to-weight ratio (i.e., the thrust per unit mass of the vehicle), and the value of n is proportional to the vehicle's speed. When the vehicle is traveling on complex terrain with high resistance, the value of i can be actively (or automatically) increased while the value of n is decreased to help the vehicle get out of trouble. When the vehicle is traveling on a smooth, straight, high-speed road with good conditions, both the values ​​of i and n can be increased to achieve a higher speed. When the vehicle is traveling on snow, ice, or slippery roads, and needs to travel at a low speed and as smoothly as possible, both the values ​​of i and n can be decreased. When the vehicle needs to drive energy-efficiently, the value of i can be decreased and the value of n increased to achieve energy saving and extend the driving range. The above adjustments can be considered as manual control or handled by the vehicle system.

[0041] i-value adjustment: The central processing unit 14 first sets the instruction signal of i-value according to the command (or automatic judgment), and then sends it to the pump displacement controller 10. The pump displacement controller accurately adjusts the pump displacement to achieve the set target of i-value. The pump pressure sensor 9 feeds back the detected pump pressure signal to the central processing unit 14 at any time to achieve full power regulation of pump group 1 and avoid overload of pump group 1 (causing damage).

[0042] Adjustment of n value: The motor speed sensor 12 feeds back the motor speed to the central processing unit 14 in real time. The central processing unit 14 performs iterative calculations in the calculation model to obtain the control signal of the motor displacement, and then transmits the signal to the motor displacement controller 11 to complete the control of the motor displacement, thereby achieving the purpose of adjusting the n value.

[0043] Based on the above calculation model, excellent system control can be achieved simply by specifying the values ​​of i and n.

Claims

1. A multi-pump multi-motor hydraulic drive system for an all-terrain vehicle comprising a pump and a central processing unit (14), characterized in that: Two or more pumps are connected in parallel to the flow divider valve group. A check valve is installed on the pressure oil line of each pump. Each flow divider valve in the flow divider valve group is connected to each motor. The weight of each car body is detected by the sensor, and the flow rate of each flow divider valve in the flow divider valve group is adjusted to ensure that the thrust-to-weight ratio of each motor is the same. The central processing unit (14) first obtains the weight of each car body, calculates the total mass as m, and the total flow rate given by the system is Q, and obtains the thrust-to-weight ratio Q / m. Based on this thrust-to-weight ratio, the flow rate of the motor on each car body is calculated.

2. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 1 wherein: The multi-pump pump group (1) includes two or more adjustable bidirectional variable pumps. The pressure oil circuits of the two directions of the adjustable bidirectional variable pumps are connected in parallel to the first diverter valve group (4) or the second diverter valve group (5). Each diverter valve in the first diverter valve group (4) and the second diverter valve group (5) is connected to a reversing valve (6). The reversing valve (6) is connected to the motor group (7). The motor group (7) integrates a quantitative diverter valve.

3. The multi-pump multi-motor hydraulic drive system for an all-terrain vehicle of claim 2, wherein: A motor speed sensor (12) and a motor displacement controller (11) are installed on each motor in the motor group (7); a pump pressure sensor (9) and a pump displacement controller (10) are installed on each adjustable bidirectional variable pump; a flow valve controller (13) is set to control the opening degree of each flow divider valve in the flow divider valve group; the motor speed sensor (12), the motor displacement controller (11), the pump pressure sensor (9), the pump displacement controller (10) and the flow valve controller (13) are all connected to the central processing unit (14).

4. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 2, wherein: The pressure oil circuits in both directions of the multi-pump pump group (1) are connected to the overflow oil circuit and a shuttle valve (2) is installed. The overflow oil circuit is connected to the safety overflow valve (3) through the shuttle valve (2).

5. The multi-pump multi-motor hydraulic drive system for an all-terrain vehicle of claim 4, wherein: The return oil port on the reversing valve (6) is connected to the oil tank (8) via the return oil circuit.

6. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 5 wherein: Let n be a parameter proportional to the vehicle speed. The motor speed is calculated using the formula n = motor flow rate / motor displacement.

7. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 6 wherein: Let the thrust-to-weight ratio Q / m = i, and adjust the values ​​of i and n according to different road conditions.

8. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 7, wherein: When driving on complex terrain with high resistance, increase the value of i and decrease the value of n; when driving on a smooth, straight highway with good road conditions, increase both the values ​​of i and n; when driving on a wet or slippery road, decrease both the values ​​of i and n; when the vehicle needs to drive in an energy-efficient manner, decrease the value of i and increase the value of n.

9. The multiple pump, multiple motor hydraulic drive system for an all-terrain vehicle of claim 8, wherein: i-value adjustment: The central processing unit (14) first sets the instruction signal of i-value according to the command or automatic judgment, and then sends it to the pump displacement controller (10). The pump displacement controller adjusts the pump displacement to achieve the set target of i-value. The pump pressure sensor (9) feeds back the detected pump pressure signal to the central processing unit (14) at any time. n-value adjustment: The motor speed sensor (12) feeds back the motor speed to the central processing unit (14) in real time. The central processing unit (14) performs iterative calculation in the calculation model to obtain the control signal of motor displacement, and then transmits the signal to the motor displacement controller (11) to complete the control of motor displacement.

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