Hydraulic drive system with adaptive speed control of cooling fan for rail engineering vehicles

Abstract

A hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle is provided. The oil outlet of a hydraulic plunger variable pump is connected to one end of a pressure pipe connected to a hydraulic motor, and the other end of the pressure pipe is connected to the oil inlet of a temperature-controlled proportional valve group. One oil outlet of each temperature-controlled proportional valve group is connected to an oil return pipe via a hydraulic oil radiator, and the oil return pipe is connected to a hydraulic oil tank. Two branches of the oil return pipe are respectively connected to the other oil outlets of the two temperature-controlled proportional valve groups. A safety protection structure connected in parallel with the hydraulic motor is provided on the pressure pipe, and the hydraulic plunger variable pump is connected to a flow regulation structure. The present invention solves the drawbacks of large system pressure shocks and extremely high noise generated when traditional on-off valve groups control the cooling fan. The system power is dynamically matched in real time according to the heat dissipation requirements to ensure safe operation of the vehicle, reduce the impact of instantaneous starting and stopping of the cooling fan, reduce the noise generated, and increase the available traction power of the vehicle power system.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail vehicles, and in particular relates to a hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle. Background Art

[0002] The existing hydraulic drive system for the cooling fan of rail engineering vehicles adopts a hydraulic quantitative system of gear pump + gear motor. The gear pump draws power from the engine power output port and is controlled by the on-off valve group to drive the hydraulic motor coaxially connected to the cooling fan to rotate, thereby achieving the purpose of cooling the vehicle power system.

[0003] When the power system is operating and the water or oil temperature is low, the hydraulic oil output by the hydraulic pump is unloaded through the on-off valve group, the hydraulic motor does not operate, and the cooling fan mechanically connected coaxially to the hydraulic motor does not rotate. When the water or oil temperature of the power system reaches the opening condition requiring heat dissipation, the on-off valve group opens instantaneously, and the hydraulic oil output by the hydraulic pump drives the gear motor mechanically connected coaxially to the cooling fan through the on-off valve group to rotate at the maximum operating speed within the power system speed. At the moment the on-off valve group opens or closes, the cooling fan speed increases from zero to the maximum operating speed or decreases from the maximum operating speed to zero in a very short period of time, causing the system pressure to increase or decrease sharply, resulting in a large pressure shock in the system and generating significant noise and impact. When the water or oil temperature of the power system is slightly higher than the heat dissipation opening condition, the power system does not need a high cooling fan operating speed to provide high-power cooling. However, the high operating speed at the system's maximum capacity also produces a certain amount of power loss, consuming and occupying the vehicle power system's available traction power. Therefore, it is necessary to improve the above-mentioned problems. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a hydraulic drive system for adaptively controlling the speed of the cooling fan of a rail engineering vehicle. By setting a flow regulation structure, the output flow of the hydraulic plunger variable pump is controlled according to the real-time engine water temperature signal fed back by the vehicle electrical system, thereby realizing the adjustment of the cooling fan speed. The drawbacks of large system pressure shock and extremely high noise caused by the traditional switch valve group controlling the on and off of the cooling fan are solved. The system power is dynamically matched in real time according to the heat dissipation demand, ensuring the safe operation of the vehicle, reducing the impact force of the instantaneous start and stop of the cooling fan, weakening the noise generated by it, reducing power loss, and improving the traction available power of the vehicle power system.

[0005] The technical solution adopted by the present invention is a hydraulic drive system for adaptively controlling the speed of the cooling fan of a rail engineering vehicle, comprising a hydraulic oil tank, two hydraulic plunger variable pumps connected in series and connected to the engine power output ports in the hydraulic transmission system and the electric transmission system, and two hydraulic motors coaxially connected to the cooling fans in the hydraulic transmission system and the electric transmission system, respectively. The oil suction ports of the two hydraulic plunger variable pumps are connected to the hydraulic oil tank through an oil suction pipe equipped with an oil suction filter, the oil outlet of the hydraulic plunger variable pump is connected to one end of a pressure pipe connected to the hydraulic motor, and the other end of the pressure pipe is connected to the inlet of a temperature control proportional valve group. The oil ports are connected, one oil outlet of the two groups of temperature-controlled proportional valve groups is connected to the return oil pipe via the hydraulic oil radiator, and the return oil pipe is connected to the hydraulic oil tank through the return oil filter, and the two branches of the return oil pipe are respectively connected to the other oil outlet of the two temperature-controlled proportional valve groups; the pressure pipe is provided with a safety protection structure connected in parallel with the hydraulic motor and used to prevent the hydraulic motor from instantaneously sucking air and limiting the maximum working pressure of the hydraulic motor, and the flow regulating structure connected to the hydraulic plunger variable pump controls the output flow of the hydraulic plunger variable pump according to the real-time water temperature signal of the engine fed back by the vehicle electrical system, thereby realizing the adjustment of the cooling fan speed.

[0006] In which, the flow regulating structure includes a pressure-compensating electric proportional control valve, the control pressure oil inlet of the pressure-compensating electric proportional control valve is connected to one end of the pressure pipe through a branch oil pipe, and the control pressure oil outlet of the pressure-compensating electric proportional control valve is connected to the variable mechanism of the hydraulic plunger variable pump, and the oil drain port of the pressure-compensating electric proportional control valve is connected to the hydraulic oil tank through the hydraulic pump oil drain pipe.

[0007] Furthermore, the safety protection structure includes an anti-cavitation one-way valve and a safety valve, and the cavitation one-way valve, the safety valve and the hydraulic motor are connected in parallel to the pressure pipe.

[0008] Furthermore, the oil drain ports of the two hydraulic motors are connected to the hydraulic oil tank through motor oil drain pipes.

[0009] Furthermore, the oil suction pipe is a Y-shaped pipeline, and the oil suction filter is installed on the main pipeline connected to the hydraulic oil tank, and the two branches of the oil suction pipe are respectively connected to the oil suction ports of the two hydraulic plunger variable pumps.

[0010] Furthermore, the hydraulic oil tank is provided with a level and temperature gauge for measuring the internal oil level and temperature and an air filter for filtering the air sucked into the tank.

[0011] The advantages of the present invention compared with the prior art are:

[0012] 1. This technical solution uses the electric proportional pressure compensation of the pressure-compensated electric proportional control valve to control the flow rate of the hydraulic plunger variable pump connected to the hydraulic motor, thereby achieving speed regulation of the cooling fan coaxially connected to the hydraulic motor, reducing pressure shock, lowering the impact force of the cooling fan's instantaneous start and stop, and reducing the noise generated;

[0013] 2. This technical solution introduces the real-time engine water temperature electrical signal detected by the original vehicle electrical control system as the input signal for the pressure-compensated electric proportional control valve to control the output oil pressure of the hydraulic plunger variable pump. This enables adaptive control of the cooling fan speed based on the real-time detected power system water and oil temperatures. The cooling fan speed is dynamically matched and adjusted in real time according to cooling needs, achieving energy conservation in the hydraulic system, reducing power loss, and increasing the available traction power of the vehicle power system.

[0014] 3. This technical solution has a simple structure and novel design. It solves the drawbacks of large system pressure shock and extremely loud noise caused by the traditional on-off valve group controlling the cooling fan on and off. It dynamically matches the system power in real time according to the heat dissipation requirements, ensures the safe operation of the vehicle through the set safety protection structure, reduces the impact force of the instantaneous start and stop of the cooling fan, weakens the noise it generates, reduces power loss, and improves the traction available power of the vehicle power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the control principle diagram of the present invention. DETAILED DESCRIPTION

[0016] The following is a combination of the embodiments of the present invention Figure 1 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0017] It should be noted that, in this document, unless otherwise stated, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate positions or relationships based on those shown in the accompanying drawings. These are intended only to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the elements.

[0019] Hydraulic drive system with adaptive speed control of cooling fan of rail engineering vehicle, such as Figure 1 As shown, it includes a hydraulic oil tank 1, two hydraulic plunger variable pumps 3 connected in series and connected to the engine power output ports in the hydraulic transmission system and the electric transmission system, and two hydraulic motors 6 coaxially connected to the cooling fans 8 in the hydraulic transmission system and the electric transmission system, respectively. The oil suction ports of the two hydraulic plunger variable pumps 3 are connected to the hydraulic oil tank 1 through an oil suction pipe 18 equipped with an oil suction filter 2, the oil outlet of the hydraulic plunger variable pump 3 is connected to one end of a pressure pipe 7 connected to the hydraulic motor 6, and the other end of the pressure pipe 7 is connected to the oil inlet of a temperature control proportional valve group 11, one oil outlet of the two groups of temperature control proportional valve groups 11 is connected to the return oil pipe 13 through a hydraulic oil radiator 12, and the return oil pipe 13 is connected to the hydraulic oil tank 1 through an oil return filter 14, and the two branches of the return oil pipe 13 The oil pump 11 and the oil pump 12 are connected to each other via the oil pump 13 and the oil pump 14. The oil pump 11 is connected to the oil pump 12 via the oil pump 13. The oil pump 11 is connected to the oil pump 12 via the oil pump 13. The oil pump 11 is connected to the oil pump 12 via the oil pump 13.

[0020] The specific structure of the flow regulation structure is as follows: the flow regulation structure includes a pressure-compensating electric proportional control valve 4, the control pressure oil inlet of the pressure-compensating electric proportional control valve 4 is connected to one end of the pressure pipe 7 through a branch oil pipe, and the control pressure oil outlet of the pressure-compensating electric proportional control valve 4 is connected to the variable mechanism of the hydraulic plunger variable pump 3, and the drain port of the pressure-compensating electric proportional control valve 4 is connected to the hydraulic oil tank 1 through the hydraulic pump drain pipe 15; in the above structure, by introducing the real-time temperature electrical signal of the engine water temperature detected by the original vehicle electrical control system, it is used as the input signal for the pressure-compensating electric proportional control valve 4 to control the output oil pressure of the hydraulic plunger variable pump 3, thereby realizing adaptive control of the cooling fan 8 speed according to the real-time detected power system water temperature and oil temperature, and dynamically matching and adjusting the cooling fan 8 speed in real time according to the cooling demand, realizing energy saving of the hydraulic system, reducing power loss, and improving the traction available power of the vehicle power system;

[0021] The safety protection structure is specifically as follows: the safety protection structure includes an anti-cavitation one-way valve 9 and a safety valve 10, and the air suction one-way valve 9, the safety valve 10 and the hydraulic motor 6 are connected in parallel to each other on the pressure pipe 7; with the above structure, when the engine stops, the hydraulic plunger variable pump 3 will stop running, and at this time, the hydraulic oil cannot be output. In order to prevent the rotating cooling fan 8 from relying on inertia to drive the hydraulic motor 6 to continue rotating and cause it to be instantaneously cavitated, an anti-cavitation one-way valve 9 is set. At this time, the return oil of the hydraulic motor 6 can enter the oil inlet side through the anti-cavitation one-way valve 9 to replenish oil, so as to avoid damage to the hydraulic motor 6 due to instantaneous cavitation. At the same time, the inlet and outlet oil ports of the hydraulic motor 6 are connected in parallel with the safety valve 10 to limit the maximum working pressure of the hydraulic motor 6 and ensure that the cooling fan 8 does not exceed the maximum working speed.

[0022] Among them, the oil drain ports of the two hydraulic motors 6 are connected to the hydraulic oil tank 1 through the motor oil drain pipe 5; specifically, the oil suction pipe 18 is a Y-shaped pipeline, and the oil suction filter 2 is installed on the main pipeline connected to the hydraulic oil tank 1, and the two branches of the oil suction pipe 18 are respectively connected to the oil suction ports of the two hydraulic plunger variable pumps 3; specifically, the hydraulic oil tank 1 is provided with a liquid level and temperature gauge 17 for measuring the internal oil level and temperature and an air filter 16 for filtering the air sucked into the interior.

[0023] The transmission forms of rail engineering vehicles are mainly hydraulic transmission and electric transmission. The power system of hydraulic transmission is mainly the engine and the hydraulic transmission. The cooling fan of the power system is divided into the engine cooling fan and the hydraulic transmission cooling fan. The power system of electric transmission is mainly the engine and the generator. The cooling fan of the power system is divided into the engine cooling fan and the generator cooling fan. The cooling fan 8 is coaxially mechanically connected to the corresponding hydraulic motor 6, and the hydraulic plunger variable pump 3 is coaxially mechanically connected to the power output port of the engine. The hydraulic plunger variable pump 3 takes power from the power output port of the engine and rotates. In addition to the above structure, it can also be driven by the power take-off port of the hydraulic transmission or the power take-off port of the generator; the oil suction port of the hydraulic plunger variable pump 3 draws oil from the hydraulic oil tank 1 and enters the oil suction side plunger volume chamber of the hydraulic plunger variable pump 3 after being filtered by the oil suction filter 2, and enters the oil outlet side plunger volume chamber after rotation, and enters the oil inlet of the hydraulic motor 6 from the oil outlet of the hydraulic plunger variable pump 3 through the pressure pipe 7, driving its rotational motion, thereby driving the cooling The fan 8 rotates, and the return oil from the oil outlet of the hydraulic motor 6 passes through the temperature control proportional valve group 11. When the temperature of the hydraulic oil returning to the oil is low, the temperature control proportional valve group 11 is in the left position, and the hydraulic oil returns to the hydraulic oil tank 1 through the return oil pipe 13 and the return oil filter 14. If the temperature of the hydraulic oil returning to the oil gradually increases, the temperature control proportional valve group 11 can move linearly from the left position to the right position as the oil temperature increases. The valve core of the temperature control proportional valve group 11 is within the middle area of ​​the valve body, and a part of the hydraulic oil returns to the oil tank 1 through the return oil pipe 13 and the return oil filter 14. Hydraulic oil tank 1, the other part of the hydraulic oil returns to the hydraulic oil tank 1 through the hydraulic oil radiator 13, the return oil pipe 13 and the return oil filter 14, thereby maintaining the temperature of the hydraulic oil at the optimal state, ensuring the hydraulic oil is at the optimal kinematic viscosity, and improving the service life of the hydraulic components. If the oil temperature is very high, the valve core of the temperature-controlled proportional valve group 11 will be in the right position of the valve body, and the return oil of all the hydraulic motors 6 will return to the hydraulic oil tank 1 through the hydraulic oil radiator 12, the return oil pipe 13 and the return oil filter 14, realizing full heat dissipation of the hydraulic return oil.

[0024] When the power system is started, the vehicle electrical control system will provide a large current signal to the pressure-compensating electric proportional control valve 4 through the controller in advance, so that the control pressure of the pressure-compensating electric proportional control valve 4 is maintained at the minimum pressure. As the engine starts, the engine will drive the hydraulic plunger variable pump 3 to rotate, and the output pressure oil will drive the hydraulic motor 6 to rotate at the lowest speed. When the power system continues to run and the temperature gradually rises, the real-time dynamic detection of the engine water temperature signal and the hydraulic transmission (or generator) oil temperature signal will be respectively output through the controller to give the corresponding and gradually decreasing current signals to the pressure-compensating electric proportional control valve 4. The pressure-compensating electric proportional control valve 4 controls the system pressure gradually, pushing its valve core linearly. It moves to the left, and the variable piston of the hydraulic plunger variable pump 3 moves toward the rodless chamber, the swash plate angle increases, the output flow of the hydraulic pump increases, and the speed of the driving hydraulic motor 6 gradually increases, and the speed of the cooling fan 8 increases accordingly, until the load pressure is balanced with the control pressure, and the control pressure is balanced with the real-time dynamic detection of the power system water temperature and oil temperature. The current size and control pressure of the pressure compensation electric proportional control valve 4 are linearly adjusted in real time according to the real-time dynamic detection of the power temperature signal, so as to realize the adaptive control of the speed of the cooling fan 8, reduce the system impact, output the system power according to the heat dissipation demand, realize the energy saving of the hydraulic system, and thus reduce the power loss. Among them, in this scheme, the hydraulic motor 6 can be bidirectional or unidirectional.

[0025] In order to ensure that the vehicle can operate normally when the electrical control system fails or the power system temperature detection signal is abnormal, the pressure-compensating electric proportional control valve 4 adopts an inverse proportional characteristic. The smaller the input current, the higher the system pressure and the higher the speed of the cooling fan 8. The larger the input current, the lower the system pressure and the lower the speed of the cooling fan 8. When there is no current signal input, the pressure-compensating electric proportional control valve 4 automatically maintains the preset maximum system pressure of the spring to ensure that the cooling fan 8 can continue to operate at the maximum operating speed, thereby ensuring the safe operation of the vehicle.

[0026] This technical solution has a simple structure and novel design. It solves the disadvantages of large system pressure shock and extremely loud noise caused by the traditional switch valve group controlling the cooling fan on and off. It dynamically matches the system power in real time according to the heat dissipation requirements, ensures the safe operation of the vehicle through the set safety protection structure, reduces the impact force of the instantaneous start and stop of the cooling fan, weakens the noise it generates, reduces power loss, and improves the traction available power of the vehicle power system.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0028] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A hydraulic drive system with adaptive speed control of cooling fans for rail engineering vehicles, characterized by: The invention comprises a hydraulic oil tank (1), two hydraulic plunger variable pumps (3) connected in series with each other and connected to the engine power output ports in the hydraulic transmission system and the electric transmission system, and two hydraulic motors (6) mechanically coaxially connected to the cooling fans (8) in the hydraulic transmission system and the electric transmission system, respectively. The hydraulic motors (6) are unidirectional hydraulic motors or bidirectional hydraulic motors. The oil suction ports of the two hydraulic plunger variable pumps (3) are connected to the hydraulic oil tank (1) through an oil suction pipe (18) equipped with an oil suction filter (2) on the main road. The oil outlet of the hydraulic plunger variable pump (3) is connected to one end of a pressure pipe (7) connected to the hydraulic motor (6), and the other end of the pressure pipe (7) is connected to the oil inlet of a temperature-controlled proportional valve group (11). The two groups of the hydraulic plunger variable pumps (3) are connected to the hydraulic oil tank (1) through an oil suction pipe (18) equipped with an oil suction filter (2) on the main road. The oil outlet of the hydraulic plunger variable pump (3) is connected to one end of a pressure pipe (7) connected to the hydraulic motor (6), and the other end of the pressure pipe (7) is connected to the oil inlet of a temperature-controlled proportional valve group (11). An oil outlet of the temperature-controlled proportional valve group (11) is communicated with the return oil pipe (13) via the hydraulic oil radiator (12), and the return oil pipe (13) is communicated with the hydraulic oil tank (1) via the return oil filter (14), and the two branches of the return oil pipe (13) are respectively communicated with the other oil outlets of the two temperature-controlled proportional valve groups (11); the pressure pipe (7) is provided with a safety protection structure connected in parallel with the hydraulic motor (6) and used to prevent the hydraulic motor (6) from instantaneous air suction and limit the maximum working pressure of the hydraulic motor (6); and a flow regulating structure connected to the hydraulic plunger variable pump (3) controls the output flow of the hydraulic plunger variable pump (3) according to the real-time engine water temperature signal fed back by the vehicle electrical system, thereby realizing the adjustment of the speed of the cooling fan (8).

2. The hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle according to claim 1, characterized in that: The flow regulating structure comprises a pressure-compensating electric proportional control valve (4), wherein a control pressure oil inlet of the pressure-compensating electric proportional control valve (4) is connected to one end of a pressure pipe (7) via a branch oil pipe, and a control pressure oil outlet of the pressure-compensating electric proportional control valve (4) is connected to a variable mechanism of a hydraulic plunger variable pump (3), and an oil drain port of the pressure-compensating electric proportional control valve (4) is connected to a hydraulic oil tank (1) via a hydraulic pump oil drain pipe (15).

3. The hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle according to claim 1, characterized in that: The safety protection structure comprises an anti-cavitation check valve (9) and a safety valve (10), and the cavitation check valve (9), the safety valve (10) and the hydraulic motor (6) are connected in parallel to the pressure pipe (7).

4. The hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle according to claim 1, characterized in that: The oil drain ports of the two hydraulic motors (6) are connected to the hydraulic oil tank (1) through motor oil drain pipes (5).

5. The hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle according to claim 1, characterized in that: The oil suction pipe (18) is a Y-shaped pipeline, and the oil suction filter (2) is installed on the main pipeline connected to the hydraulic oil tank (1), while the two branches of the oil suction pipe (18) are respectively connected to the oil suction ports of two hydraulic plunger variable pumps (3).

6. The hydraulic drive system for adaptively controlling the speed of a cooling fan of a rail engineering vehicle according to any one of claims 1 to 5, characterized in that: The hydraulic oil tank (1) is provided with a level and temperature gauge (17) for measuring the internal oil level and temperature, and an air filter (16) for filtering the air sucked into the tank.

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