Tractor radiator temperature control system and fan speed control method

Abstract

The present application relates to a kind of tractor radiator temperature control system and fan speed control method, the temperature control system includes multiple radiators and temperature sensor, silicon oil clutch is connected between fan and engine, fan speed is controlled by fan electronic control unit, silicon oil clutch combination rate is calculated with each radiator outlet temperature as final control target, upper limit uses logic or control, lower limit uses logic and control, intermediate value uses logic priority control strategy, when engine partial load, it is valued based on intake temperature priority, when full load, it is valued based on water temperature priority, avoid the phenomenon of unstable speed;Through the control of ECU, fan power consumption can be effectively reduced, and fan speed can be worked at any working point, there will be no sharp fluctuation of fan speed in fan control, effectively improve the economy and stability of tractor work.

Description

Technical Field

[0001] This invention belongs to the field of tractors, and specifically relates to a continuously variable transmission (CVT) tractor radiator temperature control system and fan speed control method. Background Technology

[0002] With societal progress and improved living standards, users have increasingly higher demands for tractors, leading to a wider range of intelligent applications. To meet these intelligent requirements, more and more components are being used. In addition to traditional engine cooling and intake cooling, separate cooling systems are needed for air conditioning condensers, transmission systems, and continuously variable hydraulic systems. Furthermore, the cooling requirements of tractor engines differ at economic speeds, maximum power points, and rated speeds, and the airflow generated by the fans varies significantly at different speeds. Currently, fans directly connected to the engine struggle to meet the airflow demands under different operating conditions. Moreover, they also fail to meet the varying cooling requirements of different tractor components due to load and continuous operating temperature environments. When multiple factors influence the cooling system, controlling fan speed solely based on the maximum airflow demand of each component can lead to unstable fan speeds and excessive airflow from directly connected fans, hindering overall energy efficiency. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a tractor radiator temperature control system and a fan speed control method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A tractor radiator temperature control system includes: an intercooler, an air conditioning condenser, a hydraulic system oil radiator, a transmission oil radiator, a water tank, a fan, a fan control unit, a silicone oil clutch, a speed sensor, and a temperature sensor. The intercooler and air conditioning condenser are arranged vertically, as are the hydraulic system oil radiator and transmission oil radiator, which are arranged vertically and sequentially in front of the fan, along with the water tank. A silicone oil clutch is installed between the fan and the engine connecting shaft. Temperature sensors are installed at the air inlet and outlet of the intercooler, the oil inlet and outlet of the hydraulic system oil radiator, the oil inlet and outlet of the transmission oil radiator, and the oil inlet and outlet of the water tank. Speed ​​sensors are installed at the driving and driven ends of the silicone oil clutch. The temperature sensor and speed sensor are connected to the fan control unit via wiring harnesses.

[0006] Furthermore, when the silicone oil clutch is energized, it is controlled by the fan control unit. Within a certain temperature range, as the temperature rises, the engagement rate of the silicone oil clutch increases steplessly. When the temperature is below the set range, the fan does not turn or operates at the minimum idle speed. When the power is off or the temperature is above the maximum warning temperature, the silicone oil clutch is fully engaged and can rotate at full speed.

[0007] A fan speed control method for a tractor radiator temperature control system is disclosed. The method uses the outlet temperature of each radiator as the final control target to determine the engagement rate of the silicone oil clutch. The engagement rate is determined based on different components. In the control logic, the upper limit of the temperature parameter for each radiator corresponds to the maximum fan speed and the maximum engagement rate of the silicone oil clutch, while the lower limit corresponds to the minimum value. Upper limit control uses OR logic, lower limit control uses AND logic, and intermediate values ​​use a logic priority control strategy to determine the silicone oil clutch engagement rate. The logic priority control strategy, considering the engine load rate, prioritizes fan speed control based on the silicone oil clutch engagement rate determined by the intake air temperature within the engine's set temperature range under partial load, based on engine economy. When approaching full load, it prioritizes fan speed control based on the silicone oil clutch engagement rate determined by the water tank outlet temperature. Transmission oil temperature and hydraulic oil temperature only participate in the upper limit logic control, thereby determining the PWM signal output by the fan control unit to control the operation of the silicone oil clutch electromagnetic coil and the output speed and torque of the silicone oil clutch.

[0008] Preferably, the upper limit of the temperature parameter can be adjusted appropriately based on different operating temperature environments, and the calculated silicone oil clutch engagement rate is uniformly corrected twice based on different operating altitude environments. The higher the operating altitude, the higher the silicone oil clutch engagement rate.

[0009] Furthermore, the control method specifically includes:

[0010] Set the operating range of the intercooler, air conditioning condenser, hydraulic system oil distributor, transmission oil distributor, and water tank outlet temperature, using Taomin, Taomax, Tromin, Tromax, Ttomin, Ttomax, Thomasin, and Thomas; among them,

[0011] Taomax and Taomin represent the upper and lower limits of the intercooler outlet temperature setting;

[0012] Tromax and Tromin represent the upper and lower limits of the outlet temperature setting for the water tank radiator;

[0013] Ttomax and Ttomin represent the upper and lower limits of the radiator outlet temperature setting in the transmission system;

[0014] Thomax and Thomin represent the upper and lower limits of the outlet temperature setting for the hydraulic system radiator;

[0015] First, based on the outlet temperatures of each radiator (Taon, Tron, Tton, Thon) collected by the temperature sensors, the fan start arbitration is initiated to determine whether to activate the silicone oil clutch. Here, Taon, Tron, Tton, and Thon represent the actual temperatures measured by the outlet sensors of the intercooler, water tank, transmission system oil radiator, and hydraulic system oil radiator, respectively.

[0016] If the water tank and intercooler outlet temperatures measured by the sensors are both lower than the minimum value of the set operating range, the silicone oil clutch will not start or will operate at the minimum engagement rate.

[0017] If either the water tank or the intercooler outlet temperature measured by the sensor is higher than the minimum value of its set operating range, the silicone oil clutch engagement rate control will be activated.

[0018] Then, the silicone oil clutch engagement rate is taken from the component arbitration. Based on the engine speed and fuel supply or output torque, the engine load is determined. If the engine power exceeds 80% of the rated power or the set engine load rate coefficient, the silicone oil clutch engagement rate calculated based on the water tank outlet temperature is output according to the control priority principle. Otherwise, the silicone oil clutch engagement rate is output according to the intercooler outlet temperature.

[0019] The silicone oil clutch engagement rate, calculated based on the water tank outlet temperature, is as follows:

[0020]

[0021] Where η represents the calculated engagement rate of the silicone oil clutch, and ηMax and ηMin represent the upper and lower limits of the engagement rate of the silicone oil clutch, which are determined by the characteristics of the silicone oil clutch.

[0022] The silicone oil clutch engagement rate, calculated based on the intercooler outlet temperature, is as follows:

[0023]

[0024] Furthermore, the engagement rate of the silicone oil clutch can be determined by weighting the engagement rate of the silicone oil clutch calculated from the water tank and intercooler, taking into account the engine load rate.

[0025] Beneficial effects: This invention connects a silicone oil clutch between the fan and the engine, and installs temperature sensors on each radiator. The radiator outlet temperature is the final control target. Based on economic considerations, the intake air temperature is prioritized for partial load, and the water temperature is prioritized for full load, thus avoiding unstable speed. The temperature control system and method, through arbitration by the fan electronic control unit and calculation of the silicone oil clutch engagement rate, can effectively reduce fan power consumption and enable the fan speed to operate at any working point. There will be no drastic fluctuations in fan speed during fan control, which can improve the economic efficiency of tractor operation. Attached Figure Description

[0026] Figure 1 A schematic diagram of the component layout for a tractor radiator temperature control system;

[0027] Figure 2 Schematic diagram of the fan clutch control principle of the tractor radiator temperature control system;

[0028] Figure 3 A flowchart for calculating the clutch engagement rate of a tractor radiator temperature control system.

[0029] Figure reference numerals: 1. Intercooler; 2. Air conditioning condenser; 3. Hydraulic system oil distributor; 4. Transmission oil distributor; 5. Water tank; 6. Fan guard; 7. Fan electronic control unit; 8. Silicon oil clutch; 10. First speed sensor; 9. Second speed sensor; 11. Engine; 12. First temperature sensor 1a; 1b. Second temperature sensor; 3a. Fourth temperature sensor 3b; 4a. Fifth temperature sensor; 4b. Sixth temperature sensor; 5a. Seventh temperature sensor; 5b. Eighth temperature sensor. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, a tractor radiator temperature control system includes: an intercooler 1, an air conditioning condenser 2, a hydraulic system oil radiator 3, a transmission oil radiator 4, a water tank 5, a fan guard 6, a fan 7, a fan electronic control unit 8, a silicone oil clutch 10, a first speed sensor 9, a second speed sensor 11, an engine 12, and temperature sensors located at the inlet and outlet of each radiator, including a first temperature sensor 1a, a second temperature sensor 1b, a third temperature sensor 3a, a fourth temperature sensor 3b, a fifth temperature sensor 4a, a sixth temperature sensor 4b, a seventh temperature sensor 5a, and an eighth temperature sensor 5b.

[0032] The intercooler 1 and the air conditioning condenser 2 are arranged vertically, and the hydraulic system oil distributor 3 and the preferred transmission oil distributor 4 are arranged vertically. They and the water tank 5 are arranged in sequence in front of the fan 7 and are surrounded by the fan guard 6. Most of the fan 7 is enclosed in the fan guard 6, and there is no peripheral bypass air intake inside the fan guard.

[0033] Preferably, the fan 7 can meet the airflow and heat dissipation requirements of the engine under the most demanding conditions at maximum torque, and the radiator assembly module can meet the heat dissipation requirements of each system under the most demanding conditions.

[0034] An electronically controlled silicone oil clutch 10 is installed between the fan 7 and the engine 12 connecting shaft. A second speed sensor 11 is installed on the driving end of the silicone oil clutch 10, and a first speed sensor 9 is installed on the driven end. The second speed sensor 11 is installed on the engine, and the first speed sensor 9 is installed inside the silicone oil clutch. The speed difference between the driving and driven ends of the silicone oil clutch can be detected.

[0035] When energized, the silicone oil clutch 10 is controlled by the fan control unit 8. Within a certain temperature range, the engagement rate of the silicone oil clutch 10 increases steplessly as the temperature rises. When the temperature is below the set range, the fan does not rotate or operates at the minimum idle speed. When the power is off or the temperature exceeds the maximum warning temperature, the silicone oil clutch 10 is fully engaged and can rotate at full speed.

[0036] Preferably, a first temperature sensor 1a and a second temperature sensor 1b are installed at the air inlet and air outlet of the intercooler 1, a third temperature sensor 3a and a fourth temperature sensor 3b are installed at the oil inlet and oil outlet of the hydraulic system oil distributor 3, a fifth temperature sensor 4a and a sixth temperature sensor 4b are installed at the oil inlet and oil outlet of the transmission oil distributor 4, and a seventh temperature sensor 5a and an eighth temperature sensor 5b are installed at the oil inlet and oil outlet of the water tank 5.

[0037] Furthermore, the first speed sensor 9, the second speed sensor 11, the first temperature sensor 1a, the second temperature sensor 1b, the third temperature sensor 3a, the fourth temperature sensor 3b, the fifth temperature sensor 4a, the sixth temperature sensor 4b, the seventh temperature sensor 5a, and the eighth temperature sensor 5b are connected to the fan control unit 8 via wiring harnesses.

[0038] like Figure 2-3 The diagrams shown are a block diagram and a flowchart of the fan speed control principle of this invention. Based on the aforementioned temperature control system, this invention uses the outlet temperature of each radiator as the final control target to solve for the engagement rate of the silicone oil clutch. The fan electronic control unit (ECU) calculates the clutch engagement rate according to the corresponding control logic based on factors such as the outlet temperature of each radiator, ambient temperature, engine load, atmospheric pressure or altitude, and engine speed collected by the sensors, and outputs a PWM signal to control the fan speed. For a single component, the higher the temperature value, the higher the fan clutch engagement rate, and vice versa.

[0039] This invention calculates the silicone oil clutch engagement rate based on different components. In the control logic, the upper limit of the temperature parameter for each heat sink corresponds to the maximum fan speed and the maximum engagement rate of the silicone oil clutch. The upper limit of the temperature parameter can be adjusted appropriately based on different operating temperature environments. The upper limit is controlled by logical OR control; the lower limit corresponds to the minimum value and is controlled by logical AND control; the intermediate value is controlled by logical priority control strategy to calculate the silicone oil clutch engagement rate; based on different operating altitude environments, the calculated silicone oil clutch engagement rate can be uniformly corrected twice. The higher the operating altitude, the higher the fan clutch engagement rate.

[0040] Furthermore, the logic priority control strategy combines engine load rate. Within the engine's set temperature range, under partial load (which can be set below 80%), based on engine economy, it prioritizes fan speed control according to the fan clutch engagement rate determined by the intake air temperature. Near full load, it prioritizes fan speed control according to the fan clutch engagement rate determined by the radiator outlet water temperature. Transmission oil temperature and hydraulic oil temperature only participate in the logic upper limit control; accordingly, the PWM signal output by the fan control unit 8 is used to control the operation of the silicone oil clutch solenoid coil and the output speed and torque of the fan clutch.

[0041] Specifically, the inlet temperature of each radiator is only used to determine whether the supply of heat medium meets the requirements. The temperature difference between the inlet and outlet of each radiator is used to determine the heat dissipation capacity of the heat exchange surface, but is not used in the calculation of the fan speed control method. This control method will not be described in detail here.

[0042] Specifically, such as Figure 2 As shown, the fan speed control method of this heat dissipation system includes the following steps:

[0043] Set the operating range of the outlet temperatures for the intercooler 1, air conditioning condenser 2, hydraulic system oil distributor 3, transmission oil distributor 4, and water tank 5, using the values ​​Taomin, Taomax, Tromin, Tromax, Ttomin, Ttomax, Thomasin, and Thomas. Among these:

[0044] Taomax and Taomin represent the upper and lower limits of the intercooler outlet temperature setting.

[0045] Tromax and Tromin represent the upper and lower limits of the outlet temperature setting for the water tank radiator.

[0046] Ttomax and Ttomin represent the upper and lower limits of the radiator outlet temperature setting for the transmission system.

[0047] Thomax and Thomin represent the upper and lower limits of the outlet temperature setting for the hydraulic system radiator.

[0048] First, based on the outlet temperatures (Taon, Tron, Tton, Thon) of each radiator collected by sensors, the system initiates fan start arbitration to determine whether to activate the silicone oil clutch. Here, Taon, Tron, Tton, and Thon represent the actual temperatures measured by the outlet sensors of the intercooler, water tank, transmission system oil radiator, and hydraulic system oil radiator, respectively.

[0049] If the water tank and intercooler outlet temperatures measured by the sensors are both lower than the minimum value of the set operating range, the silicone oil clutch will not start or will operate at the minimum engagement rate.

[0050] If either the water tank or the intercooler outlet temperature measured by the sensor is higher than the minimum value of its set operating range, the silicone oil clutch engagement rate control will be activated.

[0051] Furthermore, the system enters the maximum engagement rate determination arbitration stage for the silicone oil clutch, judging whether the outlet temperatures of the water tank, intercooler, hydraulic system oil diffuser, and transmission oil diffuser are higher than the maximum value of the set operating range. If the temperature measured by the outlet sensor of any component is higher than the maximum value of the operating range set by the corresponding component of the control system, the silicone oil clutch will operate at the maximum engagement rate.

[0052] If either the water tank or the intercooler outlet temperature measured by the sensor is higher than the minimum value of the operating range set by the control system for that component, the silicone oil clutch engagement rate will be calculated based on the water tank and intercooler outlet temperatures respectively.

[0053] Then, the silicone oil clutch engagement rate is determined from component arbitration based on engine speed and fuel supply or output torque. If the engine power exceeds 80% of the rated power or the set engine load factor, the silicone oil clutch engagement rate calculated based on the water tank outlet temperature is output according to the control priority principle. Conversely, the silicone oil clutch engagement rate is output based on the intercooler outlet temperature.

[0054] Furthermore, the silicone oil clutch engagement rate calculated based on the water tank outlet temperature is as follows:

[0055]

[0056] Where η represents the calculated engagement rate of the silicone oil clutch, and ηMax and ηMin represent the upper and lower limits of the engagement rate of the silicone oil clutch, which are determined by the characteristics of the silicone oil clutch.

[0057] Furthermore, the silicone oil clutch engagement rate calculated based on the intercooler outlet temperature is as follows:

[0058]

[0059] Furthermore, the value of the silicone oil clutch engagement rate can also be determined by weighting the silicone oil clutch engagement rate calculated from the water tank and intercooler, taking into account the engine load rate.

[0060] The temperature control system of this invention includes a heat dissipation module comprising multiple radiators to meet the heat dissipation requirements of various components of an intelligent tractor. The fan is connected to the engine via a silicone oil clutch. The engagement rate of the silicone oil clutch is calculated through arbitration by the fan electronic control unit. When the fan speed is affected by various factors, reasonable control logic effectively reduces the power consumption of the fan while ensuring the stability of the fan speed and preventing drastic fluctuations. Furthermore, the fan speed can operate at any point, thereby ensuring the economy and reliability of the engine operation.

Claims

1. A method for controlling the fan speed of a tractor radiator temperature control system, characterized in that, The temperature control system includes: an intercooler (1), an air conditioning condenser (2), a hydraulic system oil distributor (3), a transmission oil distributor (4), a water tank (5), a fan (7), a fan control unit (8), a silicone oil clutch (10), a speed sensor, and a temperature sensor. The intercooler (1) and air conditioning condenser (2) are arranged vertically, as are the hydraulic system oil distributor (3) and transmission oil distributor (4), which are arranged vertically and sequentially in front of the fan (7) along with the water tank (5). A silicone oil clutch (10) is installed between the fan (7) and the engine (12) connecting shaft. Temperature sensors are installed at the air inlet and outlet of the intercooler (1), the oil inlet and outlet of the hydraulic system oil distributor (3), the oil inlet and outlet of the transmission oil distributor (4), and the oil inlet and outlet of the water tank (5). Speed ​​sensors are installed at the driving and driven ends of the silicone oil clutch. The temperature sensor and speed sensor are connected to the fan control unit (8) via wiring harnesses. The control method uses each... The radiator outlet temperature is the ultimate control target for determining the engagement rate of the silicone oil clutch. The engagement rate is determined based on different components. In the control logic, the upper limit of the temperature parameter for each radiator corresponds to the maximum fan speed and the maximum engagement rate of the silicone oil clutch, while the lower limit corresponds to the minimum value. Upper limit control uses OR logic, lower limit control uses AND logic, and intermediate values ​​use a logic priority control strategy to determine the silicone oil clutch engagement rate. The logic priority control strategy considers the engine load rate. Within the engine's set temperature range, under partial load, based on engine economy, fan speed control prioritizes the silicone oil clutch engagement rate determined by the intake air temperature. Near full load, fan speed control prioritizes the silicone oil clutch engagement rate determined by the water tank outlet temperature. Transmission oil temperature and hydraulic oil temperature only participate in the upper limit logic control, thereby determining the PWM signal output by the fan control unit to control the operation of the silicone oil clutch solenoid coil and the output speed and torque of the silicone oil clutch.

2. The fan speed control method according to claim 1, characterized in that, When the silicone oil clutch (10) is powered on, it is controlled by the fan control unit (8). Within a certain temperature range, as the temperature rises, the silicone oil clutch engagement rate increases steplessly. When the temperature is below the set temperature range, the fan does not turn or operates at the minimum idle speed. When the power is off or the temperature is above the maximum warning temperature, the silicone oil clutch is fully engaged and can rotate at full speed.

3. The fan speed control method according to claim 1, characterized in that, The upper limit of the temperature parameter can be adjusted appropriately based on different operating temperature environments. The calculated silicone oil clutch engagement rate is uniformly corrected twice based on different operating altitude environments. The higher the operating altitude, the higher the silicone oil clutch engagement rate.

4. The fan speed control method according to claim 1, characterized in that, The control method is specifically as follows: Set the operating range of the outlet temperatures of the intercooler (1), air conditioning condenser (2), hydraulic system oil distributor (3), transmission oil distributor (4), and water tank (5), using the following values: Taomin, Taomax, Tromin, Tromax, Ttomin, Ttomax, Thomasin, and Thomas. Taomax and Taomin represent the upper and lower limits of the intercooler outlet temperature setting; Tromax and Tromin represent the upper and lower limits of the outlet temperature setting for the water tank radiator; Ttomax and Ttomin represent the upper and lower limits of the radiator outlet temperature setting in the transmission system; Thomax and Thomin represent the upper and lower limits of the outlet temperature setting for the hydraulic system radiator; First, based on the outlet temperatures of each radiator (Taon, Tron, Tton, Thon) collected by the temperature sensors, the fan start arbitration is initiated to determine whether to activate the silicone oil clutch. Here, Taon, Tron, Tton, and Thon represent the actual temperatures measured by the outlet sensors of the intercooler, water tank, transmission system oil radiator, and hydraulic system oil radiator, respectively. If the water tank and intercooler outlet temperatures measured by the sensors are both lower than the minimum value of the set operating range, the silicone oil clutch will not start or will operate at the minimum engagement rate. If either the water tank or the intercooler outlet temperature measured by the sensor is higher than the minimum value of its set operating range, the silicone oil clutch engagement rate control will be activated. Then, the silicone oil clutch engagement rate is taken from component arbitration. Based on the engine speed and fuel supply or output torque, the engine load is determined. If the engine power exceeds 80% of the rated power or other set engine load rate coefficients, the silicone oil clutch engagement rate calculated based on the water tank outlet temperature is output according to the control priority principle. Otherwise, the silicone oil clutch engagement rate is output according to the intercooler outlet temperature.

5. The fan speed control method according to claim 4, characterized in that, The silicone oil clutch engagement rate is determined by weighting the silicone oil clutch engagement rate calculated from the water tank and intercooler, taking into account the engine load rate.

Images