A cooling control system and engineering machinery

Abstract

This invention provides a cooling control system and engineering machinery, including: a temperature sensor group, a control unit, a load sensor, a mode selection unit, an engine electronic control unit, transmission components, hydraulic components, and a controller. By measuring the cooling system temperature, with sufficient heat dissipation as a constraint, and combining this with engine fuel consumption characteristics to determine the optimal engine speed, energy saving can be achieved while effectively preventing overheating damage to components caused by insufficient heat dissipation.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery and relates to a cooling control system and engineering machinery. Background Technology

[0002] Currently, construction machinery operates in diverse environments, placing high demands on overall heat dissipation. Excess heat generated by the engine, hydraulic, and transmission systems needs to be dissipated through the cooling system to ensure efficient operation of each system at appropriate temperatures. Therefore, the cooling system of construction machinery not only cools the engine but also dissipates hydraulic oil from the hydraulic system and transmission oil from the transmission system, requiring a high level of heat dissipation capacity.

[0003] Currently, most construction machinery uses a single radiator to cool the hydraulic oil and transmission oil. The hydraulic oil radiator, transmission oil radiator, and engine water-cooled radiator are located together, sharing a single cooling fan. Their cooling capacity is greatly affected by the ambient temperature and engine speed.

[0004] With construction machinery users increasingly prioritizing fuel costs, energy-saving technologies have become a crucial issue for the industry. Construction machinery operates across a wide range of conditions, and to meet extreme operational requirements, engine power is typically matched to maximum load. This results in excessively high engine power configurations under common operating conditions. The complex operating conditions of construction machinery make it difficult for operators to adjust engine operating conditions to maintain the engine within its economical operating range; the adjustments are often unreliable and impractical. Therefore, for ease of operation, operators often operate at maximum throttle opening. This leads to high fuel consumption in many conditions due to the high engine power configuration, deviating from the optimal economic operating range.

[0005] For direct-drive cooling systems, existing technologies typically adjust the engine based on load conditions to control it to operate in the optimal fuel consumption range, thereby achieving energy savings, without considering actual heat dissipation needs.

[0006] Currently, some engineering vehicles are equipped with silicone oil clutches, electromagnetic clutches, or independent cooling systems to control fan speed according to cooling requirements.

[0007] According to the universal characteristic curve of an engine, the optimal fuel consumption range for an engine is usually located in the low to medium speed range. Currently, the cooling systems of construction machinery engines are typically designed and matched based on the rated power point. When the engine operates in the low to medium speed range where fuel consumption is optimal, the cooling system fan speed is low, the airflow is small, and the cooling capacity is reduced. This poses a risk of overheating to power transmission components such as the engine, torque converter, transmission, and hydraulic components, especially in high-temperature environments, which can easily lead to overheating damage.

[0008] Silicone oil clutches, electromagnetic clutches, or independent cooling systems require additional structural designs, increasing costs. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cooling control system and engineering machinery. This system and engineering machinery have a temperature feedback function, which can effectively prevent overheating damage to power transmission components while reducing engine fuel consumption.

[0010] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0011] In a first aspect, the present invention provides a cooling control system, including a controller and a temperature sensor group, a control unit, a load sensor, a mode selection unit, an engine electronic control unit, a transmission component, and a hydraulic component, all connected to the controller.

[0012] The temperature sensor group is used to transmit temperature signals to the controller;

[0013] The control unit is used to generate operation request signals that are transmitted to the controller from the operator.

[0014] The load sensor is used to transmit load sensor signals to the controller;

[0015] The mode selection unit is used to transmit a mode selection signal to the controller;

[0016] The engine electronic control unit is used to receive control signals transmitted by the controller and control the engine according to the control signals;

[0017] The transmission component and the hydraulic component are used to receive control commands transmitted by the controller and to be in the target state according to the control commands.

[0018] Furthermore, the mode selection unit has five options: "automatic", "water temperature", "transmission oil temperature", "hydraulic oil temperature" and "high temperature".

[0019] Furthermore, when the mode selection signal transmitted from the mode selection unit to the controller is "automatic," the controller enters "automatic" mode, and the control method includes:

[0020] 1) The controller receives signals from the control unit and determines the operator's operational requirements for the entire machine;

[0021] 2) The controller receives the load sensor signal and determines the external load based on the load sensor signal;

[0022] 3) The controller determines the engine power demand based on the control unit signal and the external load, and determines the engine target speed based on the engine power demand and the engine universal characteristic curve;

[0023] 4) The controller sends control commands to the engine electronic control unit based on the engine power demand and target speed to control the engine power and speed output;

[0024] 5) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make them operate in the target state.

[0025] Furthermore, the external load includes the output power of the transmission components, the output power of the hydraulic components, and the output power of the fan;

[0026] The load sensors include pressure sensors, torque sensors, and speed sensors installed on transmission components, pressure sensors and flow sensors installed on hydraulic components, and torque sensors and speed sensors installed on fans.

[0027] Determining the external load based on the load sensor signal includes:

[0028] The output power of the transmission components is as follows:

[0029]

[0030] in, For the output power of the transmission components, The torque of the transmission components is measured by a torque sensor. The rotational speed of the transmission component is measured by a speed sensor.

[0031] Hydraulic component output power:

[0032]

[0033] Among them, P b p is the output power of the hydraulic components. b q represents the pressure of the hydraulic components measured by the pressure sensor. b The flow rate of the hydraulic components as measured by the flow sensor;

[0034] Fan output power:

[0035]

[0036] in, This refers to the fan output power. The fan torque is measured by a torque sensor. The fan speed is measured by a speed sensor.

[0037] Furthermore, the controller determines the engine power demand based on the control unit signal and the external load, and determines the engine target speed based on the engine power demand and the engine universal characteristic curve, including:

[0038] Engine power requirements:

[0039]

[0040] in, This is the ratio of required power to actual power. P is the output power of the transmission components. b Output power for hydraulic components, The ellipsis represents the output power of the fan, and the ellipsis refers to other operating devices.

[0041] The target engine speed is determined by a combination of factors, including the speed of the transmission components, the speed of the fan, and the flow rate of the hydraulic components.

[0042] Furthermore, the universal characteristic curve of the engine is a characteristic of the engine itself, obtained through engine bench tests.

[0043] Furthermore, the temperature sensor group includes an ambient temperature sensor group, an engine coolant sensor group, a transmission oil temperature sensor, and a hydraulic oil temperature sensor;

[0044] When the mode selection signal transmitted from the mode selection unit to the controller is "water temperature", "transmission oil temperature", or "hydraulic oil temperature", the controller enters the "water temperature", "transmission oil temperature", or "hydraulic oil temperature" mode. The control method includes:

[0045] 1) The controller receives signals from the control unit and determines the operator's operational requirements for the entire machine;

[0046] 2) The controller receives signals from the load sensor to determine the external load;

[0047] 3) The controller determines the engine power requirement based on the control unit signal and the load sensor signal, and determines the engine target speed based on the engine universal characteristic curve;

[0048] 4) The controller receives temperature signals from the engine coolant sensor group, transmission oil temperature sensor and hydraulic oil temperature sensor, and determines the minimum allowable engine speed that meets the heat dissipation requirements at that temperature;

[0049] 5) The controller compares the engine target speed with the engine minimum allowable speed. If the engine target speed is greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the target speed; if the engine target speed is not greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the minimum allowable speed.

[0050] 6) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make the transmission components operate in the target state.

[0051] 7) End.

[0052] Furthermore, the controller receives temperature signals from the engine coolant sensor group, transmission oil temperature sensor, and hydraulic oil temperature sensor to determine the minimum permissible engine speed at which heat dissipation requirements are met at that temperature, including:

[0053] The theoretical calculation of engine input energy uses the following formula:

[0054]

[0055] Where: Q is the cumulative fuel consumption of the engine (ml); n is the total number of sampling points; q i d represents the instantaneous fuel consumption (L / h) at the i-th sampling point; t The signal sampling interval;

[0056] The engine output energy is:

[0057] ,

[0058] In the formula: P is the engine power, E is the engine output energy, and T is the engine output power. e n represents engine torque. e Engine speed;

[0059] The engine's heat dissipation is:

[0060] R = μ(h * QE)

[0061] in, For heat dissipation, Q represents the proportion of energy carried away by the coolant, Q represents the cumulative fuel consumption of the engine (ml), and E represents the engine output energy.

[0062] The heat dissipation of hydraulic oil and transmission oil is:

[0063]

[0064] in, For heat dissipation, The proportion of energy carried away by hydraulic oil or transmission oil. To input energy, To output energy;

[0065] The required fan airflow m is:

[0066]

[0067] In the formula This indicates the specific heat capacity of a substance. Indicates air temperature. Indicates the final temperature after heat absorption;

[0068] Select the fan speed based on the required airflow and system resistance, referring to the fan's flow-static pressure curve. .

[0069] Calculation of the minimum permissible engine speed:

[0070]

[0071] In the formula: This refers to the fan speed; The transmission efficiency between the fan and the engine; This refers to the fan speed ratio.

[0072] Furthermore, when the mode selection signal transmitted from the mode selection unit to the controller is "high temperature", the controller enters the "high temperature" mode, and the control method includes:

[0073] 1) The outside air temperature is measured by an external air temperature sensor;

[0074] 2) The engine coolant temperature is measured by an engine coolant temperature sensor;

[0075] 3) The transmission oil temperature sensor measures the temperature of transmission oils such as hydraulic transmission oil and gearbox gear oil;

[0076] 4) The hydraulic oil temperature is measured by a hydraulic oil temperature sensor;

[0077] 5) The controller calculates the differences between the engine coolant temperature, transmission oil temperature, hydraulic oil temperature and the outside air temperature, respectively;

[0078] 6) Based on the difference between the engine coolant temperature and the outside air temperature, obtain the minimum permissible engine speed n1 that meets the engine coolant heat dissipation requirements; based on the difference between the transmission oil temperature and the outside air temperature, obtain the minimum permissible engine speed n2 that meets the transmission oil heat dissipation requirements; based on the difference between the hydraulic oil temperature and the outside air temperature, obtain the minimum permissible engine speed n3 that meets the hydraulic oil heat dissipation requirements.

[0079] 7) The controller compares n1, n2 and n3, finds the maximum value among the three, and determines the minimum allowable speed of the engine to meet the heat dissipation requirements.

[0080] In a second aspect, the present invention provides an engineering machine, including the cooling control system described in the first aspect.

[0081] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0082] This invention measures the temperature of engine coolant, transmission oil, and hydraulic oil, using sufficient heat dissipation as a limiting condition, and determines the optimal engine speed by combining engine fuel consumption characteristics. This enables energy saving while effectively preventing overheating damage to components caused by insufficient heat dissipation. Attached Figure Description

[0083] Figure 1 This is the cooling control system of the present invention;

[0084] Figure 2 This is the flowchart for "Automatic" mode;

[0085] Figure 3 It is a flowchart of the modes of "water temperature", "transmission oil temperature" and "hydraulic oil temperature";

[0086] Figure 4 This is the flowchart for the "high temperature" mode. Detailed Implementation

[0087] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0088] Example 1:

[0089] This embodiment provides a cooling control system, such as Figure 1 As shown, it includes: a temperature sensor group, a control unit, a load sensor, a mode selection unit, an engine electronic control unit, transmission components, hydraulic components, and a controller.

[0090] The mode selection unit offers five options: "Automatic," "Water Temperature," "Transmission Oil Temperature," "Hydraulic Oil Temperature," and "High Temperature." When a mode selection unit selects an option, it sends a corresponding signal to the controller.

[0091] The temperature sensor group includes an external atmospheric temperature sensor, an engine coolant temperature sensor, a hydraulic oil temperature sensor, and a transmission oil temperature sensor. The external atmospheric temperature sensor is connected to the controller and is used to measure the external atmospheric temperature; the engine coolant temperature sensor is connected to the controller and is used to measure the engine coolant temperature; the transmission oil temperature sensor is connected to the controller and is used to measure the temperature of transmission oils such as hydraulic transmission oil and gearbox gear oil; and the hydraulic oil temperature sensor is connected to the controller and is used to measure the hydraulic oil temperature.

[0092] The control unit includes an engine accelerator pedal or accelerator knob, a gear selector, and a hydraulic control lever. The engine accelerator pedal or accelerator knob can be an analog electronic accelerator that outputs a voltage signal, or a CAN accelerator that outputs a digital signal. The engine accelerator pedal sends the accelerator opening signal to the controller. The gear selector can be automatic or manual, and it sends the gear position signal to the controller. The hydraulic control lever sends the operator's control information to the controller.

[0093] Load sensors include pressure sensors, flow sensors, speed sensors, and torque sensors. The load sensors are connected to the controller to sense external load conditions.

[0094] The engine electronic control unit is connected to the controller and receives control commands from the controller for the engine.

[0095] The transmission components include gearboxes, reducers, etc., and the hydraulic components include hydraulic pumps, hydraulic motors, etc. The transmission components and hydraulic components are connected to the controller and receive control commands from the controller for the transmission and hydraulic components.

[0096] The controller is connected to the temperature sensor group, control unit, load sensor, engine electronic control unit, transmission components, and hydraulic components respectively. It is used to receive temperature information measured by the temperature sensor group, user control commands sent by the control unit, and load conditions sensed by the load sensor, and to send control commands to the engine electronic control unit, transmission components, and hydraulic components.

[0097] The controller determines the signal sent by the mode selection unit, and the controller's control logic is as follows:

[0098] If it is set to "automatic", the control logic is as follows: Figure 2 As shown:

[0099] 1) The controller receives signals from the control unit and determines the operator's operating requirements for the whole machine (the controller sends the operator's control information to the controller, which determines the power and speed requirements not only based on the external load but also based on the control unit signals).

[0100] 2) The controller receives signals from the load sensor to determine the external load, which mainly includes loads such as transmission components, hydraulic components, and fans;

[0101] The output power of the transmission components is as follows:

[0102]

[0103] in, For the output power of the transmission components, The torque of the transmission components is measured by a torque sensor. The rotational speed of the transmission component is measured by a speed sensor.

[0104] Hydraulic component output power:

[0105]

[0106] Among them, P b p is the output power of the hydraulic components. b q represents the pressure of the hydraulic components measured by the pressure sensor. b The flow rate of the hydraulic components as measured by the flow sensor;

[0107] Fan output power:

[0108]

[0109] in, This refers to the fan output power. The fan torque is measured by a torque sensor. The fan speed is measured by a speed sensor.

[0110] 3) The controller determines the engine power requirement based on the control unit signal and the load sensor signal, and determines the engine target speed based on the engine universal characteristic curve (the engine universal characteristic curve is the characteristic of the engine itself, obtained through engine bench testing. The speed mainly depends on the priority principle of different vehicles, whether to meet the speed requirements of transmission components, fan speed requirements, or hydraulic components first, or there is a certain weight among them).

[0111] Engine power requirements:

[0112]

[0113] in, This is the ratio of required power to actual power. P is the output power of the transmission components. b Output power for hydraulic components, This refers to the fan's output power.

[0114] The target engine speed is determined by a combination of factors, including the speed of transmission components, fan speed, and hydraulic component flow rate.

[0115] 4) The controller sends control commands to the engine electronic control unit based on the engine power demand and target speed to control the engine power and speed output;

[0116] 5) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make the transmission components operate in the target state.

[0117] If the value is "water temperature", "transmission oil temperature", or "hydraulic oil temperature", the control logic is as follows: Figure 3 As shown:

[0118] 1) The controller receives signals from the control unit and determines the operator's operational requirements for the entire machine;

[0119] 2) The controller receives signals from the load sensor to determine the external load;

[0120] 3) The controller determines the engine power requirement based on the control unit signal and the load sensor signal, and determines the engine target speed based on the engine universal characteristic curve;

[0121] 4) The controller receives temperature signals from the "water temperature", "transmission oil temperature" or "hydraulic oil temperature" sensors and determines the minimum permissible engine speed that meets the heat dissipation requirements at that temperature;

[0122] The theoretical calculation of engine input energy uses the following formula:

[0123]

[0124] Where: Q is the cumulative fuel consumption of the engine (ml); n is the total number of sampling points; q i d represents the instantaneous fuel consumption (L / h) at the i-th sampling point; t The signal sampling interval;

[0125] The engine output energy is:

[0126] ,

[0127] In the formula: P is the engine power, E is the engine output energy, and T is the engine output power. e n represents engine torque. e Engine speed;

[0128] The engine's heat dissipation is:

[0129] R = μ(h * QE)

[0130] in, For heat dissipation, Q represents the proportion of energy carried away by the coolant, Q represents the cumulative fuel consumption of the engine (ml), and E represents the engine output energy.

[0131] The heat dissipation of hydraulic oil and transmission oil is:

[0132]

[0133] in, For heat dissipation, The proportion of energy carried away by hydraulic oil or transmission oil. To input energy, To output energy;

[0134] Required fan airflow

[0135]

[0136] In the formula This indicates the specific heat capacity of a substance. Indicates air temperature. Indicates the final temperature after heat absorption;

[0137] Select the fan speed based on the required airflow and system resistance, referring to the fan's flow-static pressure curve. .

[0138] Calculation of the minimum permissible engine speed:

[0139]

[0140] In the formula: This refers to the fan speed; The transmission efficiency between the fan and the engine; This refers to the fan speed ratio.

[0141] 5) The controller compares the engine target speed with the engine minimum allowable speed. If the engine target speed is greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the target speed; if the engine target speed is not greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the minimum allowable speed.

[0142] 6) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make the transmission components operate in the target state.

[0143] 7) End.

[0144] If the temperature is "high", the control logic is as follows: Figure 4 As shown:

[0145] 1) The outside air temperature is measured by an external air temperature sensor;

[0146] 2) The engine coolant temperature is measured by an engine coolant temperature sensor;

[0147] 3) The transmission oil temperature sensor measures the temperature of transmission oils such as hydraulic transmission oil and gearbox gear oil;

[0148] 4) The hydraulic oil temperature is measured by a hydraulic oil temperature sensor;

[0149] 5) The controller calculates the differences between the engine coolant temperature, transmission oil temperature, hydraulic oil temperature and the outside air temperature, respectively;

[0150] 6) Based on the difference between the engine coolant temperature and the outside air temperature, obtain the minimum permissible engine speed n1 that meets the engine coolant heat dissipation requirements; based on the difference between the transmission oil temperature and the outside air temperature, obtain the minimum permissible engine speed n2 that meets the transmission oil heat dissipation requirements; based on the difference between the hydraulic oil temperature and the outside air temperature, obtain the minimum permissible engine speed n3 that meets the hydraulic oil heat dissipation requirements.

[0151] 7) The controller compares n1, n2 and n3, finds the maximum value among the three, and determines the minimum allowable speed of the engine to meet the heat dissipation requirements.

[0152] In step 6) above, the minimum permissible engine speed n1 that meets the engine coolant cooling requirements is obtained based on the difference between the engine coolant temperature and the outside air temperature; the minimum permissible engine speed n2 that meets the transmission oil cooling requirements is obtained based on the difference between the transmission oil temperature and the outside air temperature; and the minimum permissible engine speed n3 that meets the hydraulic oil cooling requirements is obtained based on the difference between the hydraulic oil temperature and the outside air temperature. The specific method is as follows:

[0153]

[0154] In the formula, T represents the temperature requirements of the coolant, transmission oil, and hydraulic oil; Tn refers to the measured temperature of the coolant, transmission oil, and hydraulic oil; and K is the ambient temperature. The following are the specific formulas for calculating the minimum engine speed, corresponding to the engine, transmission, and hydraulic systems respectively:

[0155] The theoretical calculation of engine input energy uses the following formula:

[0156]

[0157] Where: Q is the cumulative fuel consumption of the engine (ml); n is the total number of sampling points; qi d represents the instantaneous fuel consumption (L / h) at the i-th sampling point; t The signal sampling interval;

[0158] The engine output energy is:

[0159] ,

[0160] In the formula: P is the engine power, E is the engine output energy, and T is the engine output power. e n represents engine torque. e Engine speed;

[0161] The engine's heat dissipation is:

[0162] R = μ(h * QE)

[0163] in, For heat dissipation, Q represents the proportion of energy carried away by the coolant, Q represents the cumulative fuel consumption of the engine (ml), and E represents the engine output energy.

[0164] The heat dissipation of hydraulic oil and transmission oil is:

[0165]

[0166] in, For heat dissipation, The proportion of energy carried away by hydraulic oil or transmission oil. To input energy, To output energy;

[0167] The required fan airflow m is:

[0168]

[0169] In the formula This indicates the specific heat capacity of a substance. Indicates air temperature. Indicates the final temperature after heat absorption;

[0170] Select the fan speed based on the required airflow and system resistance, referring to the fan's flow-static pressure curve. .

[0171] Calculation of the minimum permissible engine speed:

[0172]

[0173] In the formula: This refers to the fan speed; The transmission efficiency between the fan and the engine; This refers to the fan speed ratio.

[0174] Example 2:

[0175] This embodiment provides an engineering machinery, including a cooling control system as described in Embodiment 1.

[0176] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0177] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0178] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0179] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0180] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cooling control system characterized by, This includes the controller, as well as a group of temperature sensors, a control unit, a load sensor, a mode selection unit, an engine electronic control unit, transmission components, and hydraulic components, all connected to the controller. The temperature sensor group is used to transmit temperature signals to the controller; The control unit is used to generate operation request signals that are transmitted to the controller from the operator. The load sensor is used to transmit load sensor signals to the controller; The mode selection unit is used to transmit a mode selection signal to the controller; The engine electronic control unit is used to receive control signals transmitted by the controller and control the engine according to the control signals; The transmission component and the hydraulic component are used to receive control commands transmitted by the controller and to be in a target state according to the control commands; The mode selection unit has five options: "Automatic", "Water Temperature", "Transmission Oil Temperature", "Hydraulic Oil Temperature", and "High Temperature". These options are used to transmit mode selection signals to the controller, namely "Automatic", "Water Temperature", "Transmission Oil Temperature", "Hydraulic Oil Temperature", and "High Temperature", so that the controller can enter the five modes respectively. When the mode selection signal transmitted from the mode selection unit to the controller is "automatic", the controller enters "automatic" mode, and the control method includes: 1) The controller receives signals from the control unit and determines the operator's operational requirements for the entire machine; 2) The controller receives the load sensor signal and determines the external load based on the load sensor signal; 3) The controller determines the engine power demand based on the control unit signal and the external load, and determines the engine target speed based on the engine power demand and the engine universal characteristic curve; 4) The controller sends control commands to the engine electronic control unit based on the engine power demand and target speed to control the engine power and speed output; 5) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make them operate in the target state. The temperature sensor group includes an ambient temperature sensor group, an engine coolant sensor group, a transmission oil temperature sensor, and a hydraulic oil temperature sensor; When the mode selection signal transmitted from the mode selection unit to the controller is "water temperature", "transmission oil temperature", or "hydraulic oil temperature", the controller enters the "water temperature", "transmission oil temperature", or "hydraulic oil temperature" mode. The control method includes: 1) The controller receives signals from the control unit and determines the operator's operational requirements for the entire machine; 2) The controller receives signals from the load sensor to determine the external load; 3) The controller determines the engine power requirement based on the control unit signal and the load sensor signal, and determines the engine target speed based on the engine universal characteristic curve; 4) The controller receives temperature signals from the engine coolant sensor group, transmission oil temperature sensor or hydraulic oil temperature sensor, and determines the minimum allowable engine speed that meets the heat dissipation requirements at the coolant temperature, transmission oil temperature or hydraulic oil temperature. 5) The controller compares the engine target speed with the engine minimum allowable speed. If the engine target speed is greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the target speed; if the engine target speed is not greater than the engine minimum allowable speed, the controller sends a control command to the engine electronic control unit to make the engine run at the minimum allowable speed. 6) The controller determines the target state of the transmission components based on the shift curve and the target state of the hydraulic components based on the displacement-pressure control curve. It then sends control commands to the transmission components and the hydraulic components to make the transmission components operate in the target state. 7) End; When the mode selection signal transmitted from the mode selection unit to the controller is "high temperature", the controller enters the "high temperature" mode, and the control method includes: 1) The outside air temperature is measured by an external air temperature sensor; 2) The engine coolant temperature is measured by an engine coolant temperature sensor; 3) The transmission oil temperature sensor measures the temperature of the hydraulic transmission oil and gearbox gear oil; 4) The hydraulic oil temperature is measured by a hydraulic oil temperature sensor; 5) The controller calculates the differences between the engine coolant temperature, transmission oil temperature, hydraulic oil temperature and the outside air temperature respectively; 6) Based on the difference between the engine coolant temperature and the outside air temperature, obtain the minimum permissible engine speed n1 that meets the engine coolant heat dissipation requirements; based on the difference between the transmission oil temperature and the outside air temperature, obtain the minimum permissible engine speed n2 that meets the transmission oil heat dissipation requirements; based on the difference between the hydraulic oil temperature and the outside air temperature, obtain the minimum permissible engine speed n3 that meets the hydraulic oil heat dissipation requirements. 7) The controller compares n1, n2 and n3, finds the maximum value among the three, and determines the minimum allowable speed of the engine to meet the heat dissipation requirements.

2. The cooling control system of claim 1, wherein The external load includes the output power of the transmission components, the output power of the hydraulic components, and the output power of the fan. The load sensors include pressure sensors, torque sensors, and speed sensors installed on transmission components, pressure sensors and flow sensors installed on hydraulic components, and torque sensors and speed sensors installed on fans. The external load is determined based on the load sensor signal. include: The output power of the transmission components is as follows: ； in, For the output power of the transmission components, The torque of the transmission components is measured by a torque sensor. The rotational speed of the transmission component as measured by the speed sensor; Hydraulic component output power: ； where P b is the output power of the hydraulic component, p b is the pressure of the hydraulic component measured by the pressure sensor, q b is the flow of the hydraulic component measured by the flow sensor; Fan output power: ； wherein, Pfan is the fan output power, Tfan is the fan torque measured by a torque sensor, Nfan is the fan speed measured by a speed sensor.

3. The cooling control system of claim 1, wherein, The controller determines the engine power demand based on the control unit signal and the external load, and determines the engine target speed based on the engine power demand and the engine universal characteristic curve, including: Engine power requirements: P 需 = λ(P X + P b + P F ); wherein, is the ratio of required power to actual power, is the power output of the transmission components, P b is the power output of the hydraulic components, is the power output of the fan; The target engine speed is determined by a combination of factors, including the speed of the transmission components, the speed of the fan, and the flow rate of the hydraulic components.

4. The cooling control system of claim 3, wherein, The universal characteristic curve of an engine is a characteristic of the engine itself, obtained through engine bench tests.

5. An engineering machine, comprising a cooling control system as described in any one of claims 1-4.

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