Engineering machinery fan control system and engineering machinery

Abstract

The invention discloses an engineering machinery fan control system and engineering machinery, the fan control system comprises a hydraulic oil tank, a liquid supply pump, a reversing valve and a hydraulic motor used for driving a fan, and the liquid supply pump outputs hydraulic oil in the hydraulic oil tank into the reversing valve; the reversing valve is provided with a first working position, a second working position and a third working position; when the reversing valve is located at the first working position, the reversing valve conveys hydraulic oil into the hydraulic motor and drives the hydraulic motor to rotate forwards. When the reversing valve is in the second working position, the reversing valve conveys hydraulic oil into the hydraulic motor and drives the hydraulic motor to rotate reversely; and when the reversing valve is in the third working position, the reversing valve conveys the hydraulic oil to the hydraulic oil tank, and the hydraulic motor does not work. The engineering machinery fan control system mainly solves the problem that a hydraulic motor for driving a cooling fan cannot completely stop running under specific working conditions (such as a low-temperature extremely cold environment).

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engineering machinery, and particularly relates to an engineering machinery fan control system and engineering machinery. BACKGROUND

[0002] At present, the widely used hydraulic drive type heat dissipation system in engineering machinery generally adopts a hydraulic motor to drive a cooling fan, and realizes the functions of forward rotation and reverse rotation of the fan through oil way reversing.

[0003] However, the above prior art has significant deficiencies in actual application, mainly in the following two aspects: Firstly, the existing heat dissipation system only has the functions of forward rotation and reverse rotation, lacks the control ability of fan stop, and the adjustment range of fan speed is relatively limited. In the working state of the engine, the fan speed cannot be adjusted to zero. In low temperature or extremely cold working conditions, the demand for heat dissipation of the equipment is greatly reduced, and even the fan needs to be completely stopped to avoid excessive cooling and maintain the normal working temperature of the hydraulic system. The traditional system cannot realize the fan stop and is difficult to adapt to such environmental requirements, which easily leads to problems such as low oil temperature, difficult start, and affects the performance and reliability of the whole machine.

[0004] Secondly, the driving force of the existing electric control reversing mode is limited. The thrust generated by the electromagnet is small, especially in the case of high flow and high hydraulic pressure, it is often difficult to directly push the valve core to move stably, which easily causes incomplete reversing or response delay, affecting the control accuracy and dynamic performance of the system. In addition, the electromagnet works in a high-power energized state for a long time, which easily causes overheating and shortens the service life, increasing the fault risk and maintenance cost of the system.

[0005] Therefore, it is urgent to develop a control system to solve the problem that the fan cannot be stopped in low temperature environment, and to improve the driving ability and reliability of the reversing valve in high load working conditions. SUMMARY

[0006] One of the purposes of the present application is to disclose an engineering machinery fan control system, which mainly solves the problem that the hydraulic motor driving the heat dissipation fan cannot be completely stopped in a specific working condition (such as low temperature and extremely cold environment).

[0007] The second purpose of the present application is to disclose an engineering machinery, which adopts the aforementioned engineering machinery fan control system, solving the problem of energy waste of the engineering machinery in the working process under specific working conditions.

[0008] To achieve the above objectives, this invention discloses a fan control system for engineering machinery, comprising a hydraulic oil tank, a hydraulic supply pump, a reversing valve, and a hydraulic motor for driving the fan. The hydraulic supply pump outputs hydraulic oil from the hydraulic oil tank to the reversing valve. The reversing valve has a first working position, a second working position, and a third working position. When the reversing valve is in the first working position, it supplies hydraulic oil to the hydraulic motor and drives the hydraulic motor to rotate forward. When the reversing valve is in the second working position, it supplies hydraulic oil to the hydraulic motor and drives the hydraulic motor to rotate in reverse. When the reversing valve is in the third working position, it supplies hydraulic oil to the hydraulic oil tank, and the hydraulic motor does not operate.

[0009] As an optional implementation, the reversing valve includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first valve port is connected to the outlet of the liquid supply pump, the second valve port is connected to the hydraulic oil tank, the third valve port is connected to the forward rotation port of the hydraulic motor, and the fourth valve port is connected to the reverse rotation port of the hydraulic motor. When the reversing valve is in the first working position, the first valve port is connected to the third valve port, and the second valve port is connected to the fourth valve port; when the reversing valve is in the second working position, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port; when the reversing valve is in the third working position, the first valve port is connected to the second valve port.

[0010] As an optional implementation, the directional valve is a three-position four-way electrically controlled directional valve, including a main valve core, a first pilot chamber, and a second pilot chamber. Oil enters the first pilot chamber, pushing the main valve core and controlling the directional valve to be in the second working position. Oil enters the second pilot chamber, pushing the main valve core and controlling the directional valve to be in the third working position. When neither the first pilot chamber nor the second pilot chamber enters oil, the directional valve is in the first working position.

[0011] As an optional implementation, the engineering machinery fan control system further includes a first pilot solenoid valve, which includes a valve port one, a valve port two, and a valve port three. The valve port one is connected to the outlet of the liquid supply pump, the valve port two is connected to the hydraulic oil tank, and the valve port three is connected to the first pilot chamber. When the first pilot solenoid valve is de-energized, the valve port two and the valve port three are connected, and the reversing valve is in a first working position. When the first pilot solenoid valve is energized, the valve port one and the valve port three are connected, and the reversing valve is in a second working position.

[0012] As an optional implementation, the engineering machinery fan control system further includes a second pilot solenoid valve, which includes valve port A, valve port B, and valve port C. Valve port A is connected to the outlet of the liquid supply pump, valve port B is connected to the hydraulic oil tank, and valve port C is connected to the second pilot chamber. When the second pilot solenoid valve is de-energized, valve port B and valve port C are connected, and the reversing valve is in a first working position. When the second pilot solenoid valve is energized, valve port A and valve port C are connected, and the reversing valve is in a third working position.

[0013] As an optional implementation, the engineering machinery fan control system further includes a pressure reducing valve, the inlet of which is connected to the outlet of the liquid supply pump, and the outlet of which is connected to valve port one and valve port A.

[0014] As an optional implementation, the engineering machinery fan control system further includes a safety valve, the inlet of which is connected to the outlet of the pressure reducing valve, and the outlet of which is connected to the hydraulic oil tank.

[0015] As an optional implementation, the engineering machinery fan control system also includes an overflow valve, the inlet of which is connected to the outlet of the liquid supply pump, and the outlet of which is connected to the hydraulic oil tank.

[0016] As an optional implementation, the engineering machinery fan control system also includes a valve body, wherein the reversing valve, the first pilot solenoid valve, the second pilot solenoid valve, the pressure reducing valve, the safety valve and the relief valve are all disposed in the valve body; The valve body is provided with a P port, a T port, an A port, and a B port. The A port is connected to the forward rotation port of the hydraulic motor, the B port is connected to the reverse rotation port of the hydraulic motor, the T port is connected to the hydraulic oil tank, the P port is the oil inlet and is connected to the outlet of the liquid supply pump, the A port is connected to the third valve port of the directional valve, and the B port is connected to the fourth valve port of the directional valve.

[0017] As an optional implementation, the engineering machinery fan control system also includes a speed sensor and a control unit. The control unit is electrically connected to a first pilot solenoid valve and a second pilot solenoid valve. The speed sensor acquires the real-time speed of the hydraulic motor, and the control unit collects the real-time speed signal and triggers an alarm when the real-time speed deviates from the set speed.

[0018] An engineering machine includes the aforementioned engineering machine fan control system, wherein the cooling fan is driven to rotate by the hydraulic motor in the engineering machine fan control system.

[0019] Compared with the prior art, the beneficial effects of the engineering machinery fan control system of the present invention are as follows: 1. It achieves precise adaptive control under different working conditions. This fan control system has three working modes: "forward rotation (strong heat dissipation)," "reverse rotation (dust removal / obstacle removal)," and "stop rotation (zero heat dissipation / heat preservation)." It can accurately match the diverse working conditions of construction machinery under different ambient temperatures (such as high temperature, normal temperature, and extreme cold) and different operational needs (such as heat dissipation, dust removal, and heat preservation), which significantly improves the adaptability and energy efficiency of the equipment.

[0020] 2. Improved system reliability and lifespan: This fan control system introduces a third working position (right position), allowing the hydraulic motor to be unloaded when not in operation, thus avoiding wear caused by long-term hydraulic pressure. Simultaneously, by reducing reliance on high-thrust electromagnets, the problem of overheating and damage due to prolonged energization is solved, thereby improving the reliability of the entire heat dissipation control system and the lifespan of its components.

[0021] 3. Energy consumption performance has been optimized. When the fan is not required to operate, this fan control system directly returns the hydraulic oil to the oil tank, causing the hydraulic motor to stop. The system only needs to overcome a small pipeline resistance, avoiding unnecessary power consumption from driving the fan to idle, and achieving significant energy-saving effect.

[0022] 4. Enhanced system functionality and flexibility: The three-position four-way valve design in this fan control system provides a core foundation for expanding system functions, enabling a single hydraulic system to integrate multiple functions such as heat dissipation, cleaning, and insulation, thus improving the overall integration and intelligent control potential of the machine. Furthermore, this fan control system can be easily installed on existing construction machinery, making it widely applicable. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an embodiment diagram of a fan control system for engineering machinery, specifically a schematic diagram of the reversing valve in its first operating position.

[0025] Figure 2 This is a schematic diagram of the directional valve in its second operating position.

[0026] Figure 3 This is a schematic diagram of the reversing valve in its third operating position.

[0027] Explanation of key figure labels: 1. Hydraulic oil tank; 2. Supply pump; 3. Valve body; 4. Pressure reducing valve; 5. Safety valve; 6. First pilot solenoid valve; 7. Directional control valve; 8. Speed ​​sensor; 9. Control unit; 10. Hydraulic motor; 11. Second pilot solenoid valve; 12. Relief valve. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0029] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0030] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0031] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0032] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0033] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0034] Please see Figure 1As shown in the figure, this application provides a fan control system for engineering machinery, including a hydraulic oil tank 1, a hydraulic supply pump 2, a reversing valve 7, and a hydraulic motor 10 for driving the fan. The hydraulic supply pump 2 outputs hydraulic oil from the hydraulic oil tank 1 to the reversing valve 7. The reversing valve 7 has a first working position, a second working position, and a third working position. When the reversing valve 7 is in the first working position, it delivers hydraulic oil to the hydraulic motor 10 and drives the hydraulic motor 10 to rotate forward. When the reversing valve 7 is in the second working position, it delivers hydraulic oil to the hydraulic motor 10 and drives the hydraulic motor 10 to rotate in reverse. When the reversing valve 7 is in the third working position, it delivers hydraulic oil to the hydraulic oil tank 1, and the hydraulic motor 10 does not work.

[0035] This embodiment achieves high-speed heat dissipation and cooling of engineering machinery. When the reversing valve 7 is in the first working position, it delivers hydraulic oil to the hydraulic motor 10 and drives the hydraulic motor 10 to rotate forward. Figure 1 As shown, the directional valve is in the neutral position, and the hydraulic motor 10 rotates at high speed in the forward direction under the drive of the hydraulic oil supplied by the directional valve. That is, at this time, the forward-rotating hydraulic motor 10 drives the fan to rotate in the forward direction, and the fan is in suction mode, which can be used to cool the system.

[0036] In this embodiment, the cleaning or tidying function of the construction machinery is realized. When the reversing valve 7 is in the second working position, the reversing valve 7 delivers hydraulic oil to the hydraulic motor 10 and drives the hydraulic motor 10 to reverse. Figure 2 As shown, the steering valve is in the left-hand working state, and the hydraulic motor 10 achieves high-speed reverse rotation under the drive of the hydraulic oil supplied by the steering valve. That is, at this time, the reverse-rotating hydraulic motor 10 drives the fan to reverse, and the fan blows air in reverse to clean the radiator. This can be used for cleaning or snow removal on construction machinery.

[0037] This embodiment solves the problem that the hydraulic motor 10 driving the cooling fan cannot completely stop operating under specific working conditions (such as extremely cold environments). Traditional fan control systems only have two working positions, forward and reverse, which cannot achieve fan stopping, resulting in energy waste and overcooling of the equipment when cooling is not required. This fan control system adds a third working position, namely... Figure 3 As shown, the directional valve 7 is in the right-hand operating state. The directional valve 7 is internally connected, and it delivers hydraulic oil into the hydraulic oil tank 1. The hydraulic motor 10 is not operating. This cuts off the oil supply to the hydraulic motor 10 and depressurizes it, thus reliably stopping the fan.

[0038] This embodiment achieves precise adaptive control under various operating conditions. The fan control system has three operating modes: "forward rotation (strong heat dissipation)," "reverse rotation (dust removal / obstacle removal)," and "stop (zero heat dissipation / heat preservation)." It can accurately match the diverse operating conditions of construction machinery under different ambient temperatures (such as high temperature, normal temperature, and extreme cold) and different operational needs (such as heat dissipation, dust removal, and thermal insulation), significantly improving the adaptability and energy efficiency of the equipment.

[0039] This embodiment improves the reliability and lifespan of the fan control system. By introducing a third working position (right position), the hydraulic motor 10 is unloaded when it is not working, thus avoiding wear caused by long-term hydraulic pressure.

[0040] In this embodiment, energy consumption is optimized. When the fan does not need to work, the fan control system directly returns the hydraulic oil to the hydraulic oil tank 1, causing the hydraulic motor 10 to stop. The fan control system only needs to overcome a small pipeline resistance, avoiding unnecessary power consumption from driving the fan to idle, and achieving a significant energy-saving effect.

[0041] This embodiment enhances the system's functionality and flexibility. The three-position four-way valve design in this fan control system provides a core foundation for expanding system functions, enabling a single hydraulic system to integrate multiple functions such as heat dissipation, cleaning, and insulation, thereby improving the overall integration and intelligent control potential of the machine. Furthermore, this fan control system can be easily installed on existing construction machinery, making it widely applicable.

[0042] In some embodiments, the reversing valve 7 includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first valve port is connected to the outlet of the liquid supply pump 2, the second valve port is connected to the hydraulic oil tank 1, the third valve port is connected to the forward rotation port of the hydraulic motor 10, and the fourth valve port is connected to the reverse rotation port of the hydraulic motor 10.

[0043] When the reversing valve 7 is in the first working position, the first valve port is connected to the third valve port, and the second valve port is connected to the fourth valve port.

[0044] When the reversing valve 7 is in the second working position, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port.

[0045] When the reversing valve 7 is in the third working position, the first valve port is connected to the second valve port.

[0046] In this embodiment, the directional control valve 7 has a simple structure and is easy to control. When the directional control valve 7 is in the third working position, the first valve port and the second valve port are connected, so that the unloading position is integrated within the directional control valve 7. Through the connection of the first valve port, the second valve port, the third valve port and the fourth valve port to the external structure, and the control of the conduction status of the valve ports within the directional control valve 7, the directional control valve 7 realizes centralized control of the high-speed forward rotation, high-speed reverse rotation and stop of the hydraulic motor 10.

[0047] By using the reversing valve 7 structure in this embodiment, the fan control system of this construction machinery is simplified and optimized, the control logic is simple, and the fan control system of this construction machinery can be widely used in the existing fan cooling system of construction machinery, with good adaptability.

[0048] In some embodiments, the reversing valve 7 is a three-position four-way electrically controlled reversing valve, including a main valve core and a first pilot chamber (e.g., Figure 1 In the middle, the left end of the reversing valve 7 is the first pilot chamber) and the second pilot chamber (such as... Figure 1 In the first pilot chamber, oil is obtained from the first pilot chamber, which pushes the main valve core to move and controls the reversing valve 7 to be in the second working position. When oil is obtained from the second pilot chamber, the main valve core is pushed to move and controls the reversing valve 7 to be in the third working position. When neither the first pilot chamber nor the second pilot chamber is oiled, the reversing valve 7 is in the first working position.

[0049] In this embodiment, the switching of the directional valve 7 is based on the oil supply or loss control of the first pilot chamber and / or the second pilot chamber, breaking through the bottleneck of the limited driving force of the traditional electronically controlled directional valve 7. That is, the directional valve 7 of this fan control system adopts a hydraulic drive method, avoiding the problems of small thrust and easy overheating caused by simply relying on electromagnets, making it more stable in high-flow, high-pressure hydraulic systems.

[0050] Meanwhile, because the reversing valve 7 in this embodiment reduces the reliance on high-thrust electromagnets, it solves the problem of overheating and damage caused by long-term energization, thereby improving the reliability of the entire heat dissipation control system and the service life of components. The reversing valve 7 is driven by a combination of electro-hydraulic control and hydraulic actuation. It only requires a small-thrust pilot solenoid valve to control the main valve core of the reversing valve to switch directions, eliminating the need for a high-thrust solenoid valve to drive the reversing valve, thus reducing the reliance on high-thrust solenoid valves.

[0051] In some embodiments, the engineering machinery fan control system further includes a first pilot solenoid valve 6, which includes a valve port 1, a valve port 2, and a valve port 3. The valve port 1 is connected to the outlet of the liquid supply pump 2, the valve port 2 is connected to the hydraulic oil tank 1, and the valve port 3 is connected to the first pilot chamber. When the first pilot solenoid valve 6 is de-energized, the valve port 2 and the valve port 3 are connected, and the reversing valve 7 is located in a first working position. When the first pilot solenoid valve 6 is energized, the valve port 1 and the valve port 3 are connected, and the reversing valve 7 is located in a second working position.

[0052] like Figure 2 As shown, this state indicates that the first pilot solenoid valve 6 is energized, and its valve ports 1 and 3 are connected. At this time, the hydraulic oil supplied by the pump 2 enters the left position of the directional control valve 7 through valve ports 1 and 3, pushing the left position of the directional control valve 7 to the right, thus placing the directional control valve 7 in the second working position, i.e., the left position of the directional control valve 7. The directional control valve 7 in this fan control system adopts a hydraulic drive, avoiding the problems of low thrust and overheating associated with relying solely on electromagnets, allowing for more stable application in high-flow, high-pressure hydraulic systems. It is worth noting that when the first pilot solenoid valve 6 is energized, the second pilot solenoid valve 11 is de-energized. At this time, there is no hydraulic oil in the second pilot chamber, and hydraulic oil enters the first pilot chamber, facilitating the movement of the main valve core of the directional control valve by the hydraulic oil entering the first pilot chamber. Figure 1 Hydraulic oil enters the first pilot chamber shown, controlling the main valve core of the directional valve 7 to move from the left to the right.

[0053] The energization and de-energization status of the first pilot solenoid valve 6 is controlled by the control unit 9.

[0054] In some embodiments, the engineering machinery fan control system further includes a second pilot solenoid valve 11, which includes a valve port A, a valve port B, and a valve port C. The valve port A is connected to the outlet of the liquid supply pump 2, the valve port B is connected to the hydraulic oil tank 1, and the valve port C is connected to the second pilot chamber. When the second pilot solenoid valve 11 is de-energized, the valve port B and the valve port C are connected, and the reversing valve 7 is in a first working position. When the second pilot solenoid valve 11 is energized, the valve port A and the valve port C are connected, and the reversing valve 7 is in a third working position.

[0055] like Figure 3As shown, this state indicates that the second pilot solenoid valve 11 is energized, and its ports A and C are connected. At this time, the hydraulic oil supplied by the pump 2 enters the left position of the directional control valve 7 through ports A and C, pushing the right position of the directional control valve 7 to the left, thus placing the directional control valve 7 in the third operating position, i.e., the right position of the directional control valve 7. The directional control valve 7 in this fan control system adopts a hydraulic drive, avoiding the problems of low thrust and overheating associated with relying solely on electromagnets, allowing for more stable application in high-flow, high-pressure hydraulic systems.

[0056] The energization and de-energization status of the first pilot solenoid valve 6 is controlled by the control unit 9.

[0057] When both the first pilot solenoid valve 6 and the second pilot solenoid valve 11 are de-energized, such as Figure 1 As shown, in this state, the valve port 2 and valve port 3 of the first pilot solenoid valve 6 are connected, that is, the left position of the directional valve 7 is connected to the hydraulic oil tank 1 through the first pilot solenoid valve 6; the valve port B and valve port C of the second pilot solenoid valve 11 are connected, that is, the right position of the directional valve 7 is connected to the hydraulic oil tank 1 through the second pilot solenoid valve 11. That is, both the first pilot chamber and the second pilot chamber are connected to the hydraulic oil tank 1, and the pressure in the first pilot chamber and the second pilot chamber is zero, which ensures that the directional valve 7 is in the neutral position, that is, ensures that the directional valve 7 is in the first working position.

[0058] In some embodiments, the engineering machinery fan control system further includes a pressure reducing valve 4, the inlet of which is connected to the outlet of the liquid supply pump 2, and the outlet of which is connected to the valve port 1 and the valve port.

[0059] When the first pilot solenoid valve 6 is energized, or the second pilot solenoid valve 11 is energized, the hydraulic oil delivered by the supply pump 2 enters the first pilot solenoid valve 6 or the second pilot solenoid valve 11 through the pressure reducing valve 4, and then enters the first pilot chamber or the second pilot chamber through the first pilot solenoid valve 6 or the second pilot solenoid valve 11. The pressure reducing valve 4 is provided here to reduce and stabilize the hydraulic pressure delivered by the supply pump 2, ensuring the normal operation of the main valve core of the directional valve.

[0060] In some embodiments, the engineering machinery fan control system further includes a safety valve 5, the inlet of which is connected to the outlet of the pressure reducing valve 4, and the outlet of which is connected to the hydraulic oil tank 1.

[0061] When the first pilot solenoid valve 6 and / or the second pilot solenoid valve 11 are de-energized, the hydraulic oil supplied by the hydraulic pump 2 passes through the pressure reducing valve 4 to the first pilot solenoid valve 6 and valve port 1 and / or valve port A of the second pilot solenoid valve 11, and accumulates at the first pilot solenoid valve 6 and valve port 1 and / or valve port A of the second pilot solenoid valve 11. When the pressure is high enough, the hydraulic oil opens the safety valve 5 and flows back to the hydraulic oil tank 1 through the safety valve 5, thereby relieving pressure and protecting the pipeline.

[0062] In some embodiments, the engineering machinery fan control system further includes an overflow valve 12, the inlet of which is connected to the outlet of the liquid supply pump 2, and the outlet of which is connected to the hydraulic oil tank 1.

[0063] When the flow rate of hydraulic oil delivered by the supply pump 2 is greater than the hydraulic oil required by the hydraulic motor 10, the excess hydraulic oil, after entering the reversing valve 7, flows back to the hydraulic oil tank 1 through the relief valve 12, thereby protecting the pipeline. In some embodiments, the engineering machinery fan control system further includes a speed sensor 8 and a control unit 9. The control unit 9 is electrically connected to a first pilot solenoid valve 6 and a second pilot solenoid valve 11. The speed sensor 8 acquires the real-time speed of the hydraulic motor 10. The control unit 9 collects the real-time speed signal and triggers an alarm when the real-time speed deviates from the set speed.

[0064] The speed sensor 8 will monitor in real time whether the speed of the hydraulic motor 10 deviates from the set range. If the speed sensor 8 detects a sudden drop in the speed of the hydraulic motor 10, the system can trigger an alarm and limit the engine power to prevent overheating and damage.

[0065] The fan control system for construction machinery disclosed in this application adds an unloading position (third working position) to the reversing valve 7, enabling the fan to stop. Stopping the fan allows the oil and water temperatures to rapidly rise to the optimal thermal equilibrium temperature when the engine starts, improving work efficiency. Furthermore, in extremely cold or relatively cold environments, controlling the fan to stop reduces energy consumption and shortens the time it takes for the construction machinery to reach normal operating conditions.

[0066] In the engineering machinery fan control system of this application, the reversing valve 7 is a composite design of "electric control + hydraulic drive", which achieves a balance between driving force, control accuracy and environmental adaptability, and is particularly suitable for complex systems with large tonnage, large flow, high pressure, heavy load and high reliability requirements. The composite design of the reversing valve 7 is "electric control + hydraulic drive", which means that the control unit 9 controls the first pilot solenoid valve 6 and / or the second pilot solenoid valve 11 to be energized or de-energized, and the first pilot chamber and the second pilot chamber drive the reversing valve 7 to switch.

[0067] The engineering machinery fan control system of this application achieves energy-saving optimization by using a low-power electromagnet, which can realize the reversing function of the main valve core of the reversing valve 7 with a low current, and the fan stop function can further reduce oil consumption.

[0068] The engineering machinery fan control system of this application achieves cost optimization and pilot oil circuit self-pressure technology. The pilot oil is used to drive the main valve core after the oil is depressurized by taking oil from the main oil circuit. There is no need to set up a separate pilot oil source, which not only reduces costs and increases efficiency, but also simplifies the pipeline layout of the system.

[0069] In some embodiments, the engineering machinery fan control system further includes a valve body 3, wherein the reversing valve 7, the first pilot solenoid valve 6, the second pilot solenoid valve 11, the pressure reducing valve 4, the safety valve 5 and the overflow valve 12 are all disposed within the valve body 3; The valve body 3 is provided with a P port, a T port, an A port, and a B port. The A port is connected to the forward rotation port of the hydraulic motor 10, the B port is connected to the reverse rotation port of the hydraulic motor 10, the T port is connected to the hydraulic oil tank 1, the P port is the oil inlet and is connected to the outlet of the liquid supply pump 2, the A port is connected to the third valve port of the reversing valve 7, and the B port is connected to the fourth valve port of the reversing valve 7.

[0070] In this embodiment, the reversing valve 7, the first pilot solenoid valve 6, the second pilot solenoid valve 11, the pressure reducing valve 4, the safety valve 5, and the overflow valve 12 are all disposed within the valve body 3. Each valve is integrated and packaged with the valve body 3 to achieve an integrated design and reduce the number of leakage points in the pipeline.

[0071] In the construction machinery fan control system of this application, when the excavator is operating normally, the directional valve 7 is in the neutral position, and the first pilot solenoid valve 6 and the second pilot solenoid valve 11 are de-energized. The oil circuits connected to the left and right sides of the directional valve 7 are cut off. At this time, the directional valve 7 remains in the neutral position, and the hydraulic motor 10 drives the fan to rotate in the forward direction. The fan is in suction mode, which can be used to cool the system. Hydraulic oil drawn from the main oil circuit and depressurized by the pressure reducing valve 4 accumulates before the first pilot solenoid valve 6 and the second pilot solenoid valve 11. When the pressure reaches the opening pressure of the safety valve 5, part of the hydraulic oil flows back to the oil tank through the safety valve 5, maintaining the pressure before the first pilot solenoid valve 6 and the second pilot solenoid valve 11 at a constant value, reducing potential damage. The relief valve 12 limits the maximum pressure of the cooling system, serving as a protective element.

[0072] When it is necessary to reverse the fan to clean the radiator, first stop the machine to stop the fan, power on the machine but do not start the engine, and press the fan reverse button on the instrument panel. The control unit 9 will output a signal to energize the first pilot solenoid valve 6. At this time, start the engine, and the hydraulic oil drawn from the main oil circuit and depressurized by the pressure reducing valve 4 flows through the passage of the first pilot solenoid valve 6 to the left side of the reversing valve 7, pushing the left position of the reversing valve 7 to the right, so that the reversing valve 7 is in the left position. The high pressure oil in the main oil circuit enters the right side of the hydraulic motor 10 through the left position of the reversing valve 7, causing the hydraulic motor 10 to reverse, thereby driving the fan to reverse and blow air to achieve the purpose of cleaning the radiator. After the radiator cleaning is completed, the machine is stopped and powered on. The fan reverse function is turned off by touching the instrument. The control unit 9 outputs a signal to de-energize the first pilot solenoid valve 6. At this time, the pilot pressure oil on the left side of the reversing valve 7 flows back to the oil tank through the oil circuit of the first pilot solenoid valve 6. The reversing valve 7 returns to the neutral position under the action of the spring force. At this time, the engine is started, and the hydraulic motor 10 and the fan return to the forward rotation state. The fan draws air to cool the system.

[0073] When the oil and water temperatures are lower than the set temperatures, the control unit 9 outputs a signal to energize the second pilot solenoid valve 11. Hydraulic oil drawn from the main oil circuit and depressurized by the pressure reducing valve 4 flows through the passage of the second pilot solenoid valve 11 to the right side of the directional valve 7, pushing the main valve core to the left and placing the directional valve 7 in the right position, i.e., the unloaded position. The hydraulic oil in the main oil circuit flows back to the oil tank through the right-side oil passage of the directional valve 7, ensuring that the pressure on both sides of the hydraulic motor 10 is equal and it cannot rotate, thus stopping the hydraulic motor 10. This allows the oil and water temperatures to rise rapidly to the optimal thermal equilibrium temperature. When the oil and water temperatures reach the set temperatures, the control unit 9 outputs a signal to de-energize the second pilot solenoid valve 11. The pilot pressure oil on the right side of the directional valve 7 flows back to the oil tank through the oil passage of the second pilot solenoid valve 11. The directional valve 7 returns to the neutral position under the action of the spring force, and the hydraulic motor 10 and the fan resume forward rotation, with the fan drawing air to cool the system.

[0074] The liquid supply pump 2 in this application is a load-sensitive plunger pump, which is a commonly used liquid pump in the hydraulic system of existing engineering machinery.

[0075] This application also discloses an engineering machinery, including a cooling fan and the aforementioned engineering machinery fan control system. The cooling fan is driven to rotate by the hydraulic motor 10 in the engineering machinery fan control system, which solves the problem of energy waste during the operation of engineering machinery under specific working conditions and solves the problem that the fan on existing engineering machinery cannot be stopped.

[0076] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A fan control system for engineering machinery, characterized in that, The device includes a hydraulic oil tank, a hydraulic supply pump, a directional valve, and a hydraulic motor for driving a fan. The hydraulic supply pump outputs hydraulic oil from the hydraulic oil tank to the directional valve. The directional valve has a first working position, a second working position, and a third working position. When the directional valve is in the first working position, it supplies hydraulic oil to the hydraulic motor and drives the hydraulic motor to rotate forward. When the directional valve is in the second working position, it supplies hydraulic oil to the hydraulic motor and drives the hydraulic motor to rotate in reverse. When the directional valve is in the third working position, it supplies hydraulic oil to the hydraulic oil tank, and the hydraulic motor does not operate.

2. The engineering machinery fan control system according to claim 1, characterized in that, The reversing valve includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first valve port is connected to the outlet of the liquid supply pump, the second valve port is connected to the hydraulic oil tank, the third valve port is connected to the forward rotation port of the hydraulic motor, and the fourth valve port is connected to the reverse rotation port of the hydraulic motor. When the reversing valve is in the first working position, the first valve port is connected to the third valve port, and the second valve port is connected to the fourth valve port; when the reversing valve is in the second working position, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port; when the reversing valve is in the third working position, the first valve port is connected to the second valve port.

3. The engineering machinery fan control system according to claim 1 or 2, characterized in that, The reversing valve is a three-position four-way electrically controlled reversing valve, including a main valve core, a first pilot chamber and a second pilot chamber. When oil enters the first pilot chamber, it pushes the main valve core and controls the reversing valve to be in the second working position. When oil enters the second pilot chamber, it pushes the main valve core and controls the reversing valve to be in the third working position. When neither the first pilot chamber nor the second pilot chamber enters oil, the reversing valve is in the first working position.

4. The engineering machinery fan control system according to claim 3, characterized in that, It also includes a first pilot solenoid valve, which includes a valve port 1, a valve port 2, and a valve port 3. The valve port 1 is connected to the outlet of the liquid supply pump, the valve port 2 is connected to the hydraulic oil tank, and the valve port 3 is connected to the first pilot chamber. When the first pilot solenoid valve is de-energized, the valve port 2 and the valve port 3 are connected, and the directional valve is in a first working position. When the first pilot solenoid valve is energized, the valve port 1 and the valve port 3 are connected, and the directional valve is in a second working position. It also includes a second pilot solenoid valve, which includes valve port A, valve port B, and valve port C. Valve port A is connected to the outlet of the liquid supply pump, valve port B is connected to the hydraulic oil tank, and valve port C is connected to the second pilot chamber. When the second pilot solenoid valve is de-energized, valve port B and valve port C are connected, and the directional valve is in the first working position. When the second pilot solenoid valve is energized, valve port A and valve port C are connected, and the directional valve is in the third working position.

5. The engineering machinery fan control system according to claim 4, characterized in that, It also includes a pressure reducing valve, the inlet of which is connected to the outlet of the liquid supply pump, and the outlet of which is connected to valve port one and valve port A.

6. The engineering machinery fan control system according to claim 5, characterized in that, It also includes a safety valve, the inlet of which is connected to the outlet of the pressure reducing valve, and the outlet of which is connected to the hydraulic oil tank.

7. The engineering machinery fan control system according to claim 6, characterized in that, It also includes an overflow valve, the inlet of which is connected to the outlet of the liquid supply pump, and the outlet of which is connected to the hydraulic oil tank.

8. The engineering machinery fan control system according to claim 7, characterized in that, It also includes a valve body, in which the directional valve, the first pilot solenoid valve, the second pilot solenoid valve, the pressure reducing valve, the safety valve, and the relief valve are all disposed; The valve body is provided with a P port, a T port, an A port, and a B port. The A port is connected to the forward rotation port of the hydraulic motor, the B port is connected to the reverse rotation port of the hydraulic motor, the T port is connected to the hydraulic oil tank, the P port is the oil inlet and is connected to the outlet of the liquid supply pump, the A port is connected to the third valve port of the reversing valve, and the B port is connected to the fourth valve port of the reversing valve.

9. The engineering machinery fan control system according to claim 1 or 2, characterized in that, It also includes a speed sensor and a control unit. The control unit is electrically connected to the first pilot solenoid valve and the second pilot solenoid valve. The speed sensor acquires the real-time speed of the hydraulic motor. The control unit collects the real-time speed signal and triggers an alarm when the real-time speed deviates from the set speed.

10. An engineering machinery, characterized in that, The system includes a cooling fan and a construction machinery fan control system as described in any one of claims 1 to 9, wherein the cooling fan is driven to rotate by the hydraulic motor in the construction machinery fan control system.

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