TWI677447B - Vehicle cooling control system and method thereof - Google Patents

Abstract

A vehicle cooling control method includes the steps of: obtaining an engine speed, an engine speed sensor sensing the speed of the engine, and providing the speed to a heat dissipation control unit; calculating a control percentage effective interval, and the heat dissipation control unit is based on The speed, and find the effective percentage of the control percentage; calculate the actual control percentage, the thermal control unit based on the effective percentage of the control percentage to find the actual control percentage; the thermal control unit outputs the actual control percentage, the thermal control unit will The actual control percentage is provided to a proportional valve; and the proportional valve is driven, and the proportional valve adjusts the opening degree of the proportional valve according to the actual control percentage to change the flow rate or pressure of hydraulic oil output by a pump.

Description

Vehicle cooling control system and method

A vehicle cooling control system and method thereof, particularly to find out the most suitable control percentage and provide it to a control valve, thereby controlling the flow or pressure flowing into a pump, so that the cooling fan can provide a better cooling mode for the engine System and method.

Idle speed refers to the state in which the internal combustion engine (engine) maintains the minimum operating speed. However, under idle conditions, the engine may face at least four problems. One is that the engine cannot provide sufficient power to the pump, and the pump cannot provide sufficient hydraulic pressure or flow of hydraulic oil to the cooling fan. This hydraulic oil rotates the cooling fan. When the hydraulic pressure or flow is large, the speed of the cooling fan is faster, and the cooling effect of the engine's coolant is better. When the hydraulic pressure or flow rate is small, the speed of the cooling fan is slower, and the cooling effect of the engine's coolant is poor; the second is that the engine is overheating, and the cooling fan cannot provide sufficient heat dissipation; The engine is not overheating, and the cooling fan provides excessive heat dissipation.

In order to overcome the foregoing problems, there are two existing methods. First, in order to enable the hydraulic oil of the cooling system to drive the cooling fan, the volume of the pump will be increased so that the pump can provide sufficient hydraulic pressure at idle speed of the engine; To use a double pump so that one pump can provide sufficient hydraulic pressure. If a single pump is used, it may be limited by the volume the vehicle can hold. If a dual pump is used, it is possible to have its pump provide excessive hydraulic pressure.

To sum up, the existing engines may face the problems of heat dissipation and hydraulic pressure when idling, so there is room for discussion on how to overcome the aforementioned problems.

The vehicle cooling control method provided by the present invention includes the steps of: obtaining an engine speed, an engine speed sensor sensing the speed of the engine, and providing the speed to a heat dissipation control unit; calculating an effective interval of the control percentage, The cooling control unit finds the effective percentage of the control percentage based on the rotation speed; calculates the actual control percentage; finds the actual control percentage according to the effective percentage of the control percentage; the cooling control unit outputs the actual control percentage The heat dissipation control unit provides the actual control percentage to a proportional valve; and drives the proportional valve to adjust the opening of the proportional valve according to the actual control percentage to change the flow of hydraulic oil output by a pump Or pressure.

The invention further proposes a vehicle cooling control system, which is suitable for an engine and a pump, the pump system is coupled to a proportional valve, and the vehicle cooling control system includes: an engine speed sensor, which is provided in The engine; a proportional valve provided on the pump; and a heat dissipation control unit electrically connected to the engine speed sensor and the pump; wherein the engine speed sensor senses the engine And the rotation speed is provided to the heat dissipation control unit, and the heat dissipation control unit obtains a control percentage effective interval based on the rotation speed; the heat dissipation control unit obtains an actual control percentage based on the control percentage effective interval, The proportional valve is provided to adjust the opening degree of the proportional valve and change the flow rate or pressure of the hydraulic oil output by the pump.

Please refer to FIG. 1 for reference. The present invention is a vehicle cooling control system, which is applied to an engine 10 and a pump 11. The vehicle cooling control system includes an engine speed sensor 100, an intake air temperature sensor 101, a fluid temperature sensor 110, a proportional valve 111, and a heat dissipation control unit 13.

The engine 10 is coupled to the pump 11, and the engine 10 provides power to the pump 11. The engine speed sensor 100 and the intake air temperature sensor 101 are provided on the engine 10. The fluid temperature sensor 110 is provided in the pump 11. The pump 11 has a flow sensor 112 inside. The pump 11 is coupled to a cooling unit 12. The cooling unit 12 has a cooling fan 120 and a fan speed sensor 121. The hydraulic oil output from the pump 11 is provided to the cooling fan 120, and the cooling fan 120 is rotated, thereby reducing the water temperature of the cooling water of the engine 10. The heat dissipation control unit 13 is electrically connected to the engine 10, the pump 11 and the cooling unit 12. The pump 11 is a variable flow pump or a variable flow pump and a certain amount of pump system.

The engine speed sensor 100 senses the rotation speed of the engine 10 and supplies the rotation speed to the heat dissipation control unit 13, and the heat dissipation control unit 13 obtains a control percentage effective interval based on the rotation speed; An actual control percentage is obtained and provided to the proportional valve 111 to adjust the opening degree of the proportional valve 111 so as to change the flow rate or pressure of the hydraulic oil output by the pump 11. The flow rate or pressure of the hydraulic oil can affect the speed of the cooling fan 120. When the flow rate or pressure is large, the speed of the cooling fan 120 is faster. When the flow rate or pressure is small, the rotation speed of the cooling fan 120 is slower.

The intake air temperature sensor 101 senses the ambient temperature of the engine 10 and provides the ambient temperature to the heat dissipation control unit 13.

The fluid temperature sensor 110 senses the water temperature of the cooling water of the engine 10 and supplies the water temperature to the heat dissipation control unit 13.

The flow sensor 112 senses the flow of the hydraulic oil output from the pump 11 and supplies the flow to the heat dissipation control unit 13.

The heat radiation control unit 13 obtains the control percentage corresponding to the ambient temperature and the control percentage corresponding to the water temperature according to the ambient temperature and the water temperature, and compares the two. If one is large, the larger one is taken and is regarded as A strict control percentage, based on the strict control percentage, the heat dissipation control unit 13 obtains a one-minute gradual change control percentage, which is then provided to the proportional valve 111 which can change the pump 11 to adjust the opening degree of the proportional valve 111 to achieve Change the flow or pressure of the hydraulic oil output from the pump 11. The time-sharing gradual change control percentage is based on dividing a time region into several time divisions, and the control percentage of each time division is obtained.

The fan speed sensor 121 senses the fan speed of the heat dissipation fan 120 and provides the fan speed to the heat dissipation control unit 13. The cooling fan 120 is a combination of a hydraulic motor and a fan blade. The cooling fan 120 is a cooling liquid used to cool the engine 10. The cooling fan 120 is driven by the hydraulic oil output from the pump 11. The heat radiation control unit 13 provides the control percentage to the proportional valve 111 to change (control) the opening degree of the proportional valve 111 so as to change the flow rate or pressure of the pump 11 and change the rotation speed of the heat radiation fan 120.

Please refer to FIG. 2 for reference. The present invention is a vehicle cooling control method. The steps include:

In step S1, the engine speed is obtained. The engine speed sensor 100 senses the speed of the engine 10 and provides the speed to the heat dissipation control unit 13.

Step S2: Calculate the effective interval of the control percentage. Please refer to Figure 3 for reference. Line segment a and line b are experimental data. You can draw this graph by obtaining 4 coordinate points. The area surrounded by the four line segments a, b, c, and d.

As shown in Figure 3, PWM d = (X3-X2) (Y3-Y2) / (X3-X2) + Y2, which represents the PWM value corresponding to each standard of line segment d. As shown in Figure 3, PWM c = (X1-X0) (Y1-Y0) / (X1-X0) + Y0, which represents the PWM value corresponding to each standard of line segment d. X and Y described in the figure above are coordinate values.

For example, when the engine speed is 1500 rpm, the heat dissipation control unit 13 obtains that the effective percentage of the control percentage is 25% to 82% according to FIG. 3.

In step S3, the ambient temperature and the water temperature are obtained. The intake air temperature sensor 101 senses the ambient temperature of the engine 10. The intake air temperature sensor 101 provides the ambient temperature to the heat dissipation control unit 13. The fluid temperature sensor 110 senses the water temperature of the cooling water from the engine 10 and supplies the water temperature to the heat dissipation control unit 13. The flow sensor 112 senses the flow or pressure of the hydraulic oil of the pump 11 and provides the flow or pressure to the heat dissipation control unit 13 for the heat dissipation control unit 13 to determine whether there is an abnormality in the flow or pressure; or the hydraulic pressure The flow rate or pressure of the oil flowing into the cooling unit 12 is provided to the heat dissipation control unit 13 for the heat dissipation control unit 13 to determine whether there is an abnormality in the flow rate or pressure.

Step S4, find out the control percentage corresponding to the ambient temperature and the water temperature, as shown in the table below. For example, when Ta is 40 ° C, Tw is 90 ° C. As shown in the following table, the control percentage of Ta at 40 ° C is 60%; the control percentage of Tw at 90 ° C is 40%. project 1 2 3 4 5 Ambient temperature Ta (engine air intake end) ＜ 28 ℃ 28 ℃ ≦ Ta ＜ 33 ℃ 33 ℃ ≦ Ta ＜ 38 ℃ 38 ℃ ≦ Ta ＜ 43 ℃ 43 ℃ ≦ Ta ＜ 48 ℃ Ta ≧ 48 ℃ Water temperature Tw ＜ 85 ℃ 85 ℃ ≦ Tw ＜ 90 ℃ 90 ℃ ≦ Tw ＜ 92 ℃ 92 ℃ ≦ Tw ＜ 94 ℃ 94 ℃ ≦ Tw ＜ 96 ℃ Tw ≧ 96 ℃ Control valve control percentage (PWM) 0 20% 40% 60% 80% 100%

In the actual environment, the control percentage is 60%, in the most severe way. By the same token, the following table is obtained: project Level 1 Level 2 Level 3 Level 4 ... Level N Ambient temperature Ta (engine air intake end) Ta1 Ta2 Ta3 Ta4 ... TaN Water temperature Tw Tw1 Tw2 Tw3 Tw4 ... TwN Control valve control percentage (PWM) PWM1 PWM2 PWM3 PWM4 ... PWMN

As shown in the table above, the control percentage of the control valve has PWM1, PWM2, ..., PWMN, which correspond to the first stage, the second stage, ..., and the third stage. PWMN is greater than PWMN-1; PWMN-1 is greater than PWMN-2; ...; PWPM2 is greater than PWM1.

Similarly, the ambient temperature has Ta1, Ta2, Ta3, ..., TaN, which correspond to the first, second, ..., Nth stages. TaN is greater than TaN-1; TaN-1 is greater than TaN-2; ...; Ta2 is greater than Ta1.

Similarly, the water temperature has Tw1, Tw2, Tw3, ..... TwN, which corresponds to the first level, the second level, ..., and the Nth level. If the ambient temperature is Ta3, it belongs to the third stage, and the third stage corresponds to PWM3. If the water temperature is Tw2, it belongs to the second stage, and the second stage corresponds to PWM2. PWM3 is larger than PWM2, so PWM3 is a strict PWM.

In step S5, the actual control percentage is calculated. The formula is: Actual PWM = lower limit PWM + (upper limit PWM / 100) × (upper limit PWM – lower limit PWM). For example, when the engine speed is 1500 rpm, the effective range of the control percentage is 25% to 82%. So the upper limit PWM is 82%. The lower limit PWM is 25%. The above upper limit PWM and lower limit are brought into the above formula, and we get: Actual PWM = 25 + (82/100) × (82-25) = 71.74%.

In step S6, the heat dissipation control unit outputs the actual control percentage (time-sharing control percentage). The heat radiation control unit 13 supplies the actual PWN to the pump 11.

If it is the percentage of time-sharing control, it is divided into a plurality of equal time in a time section. For example, if the time segment is 5 seconds, it can be divided into five equal time periods, and each equal time period is 1 second.

At each aliquot, read the information of the sensors (engine speed sensor 100, intake temperature sensor 101, fluid temperature sensor 110) to determine the actual PWM for each aliquot, which is Time-shared gradient control percentage.

The PWM difference formula is as follows: PWM _difference = actual PWM-severe PWM. As mentioned above, the formula for the new PWM setting value is: PWM _{equalization time} = Strict PWM + (PWM _difference ) × Nth equalization time / number of divisions; N is a constant.

For example, if the time period is 5 seconds, it can be divided into five equal time periods, and each equal time period is 1 second. PWM _1s = Severe PWM + (PWM _difference ) × _1/5 ; PWM _2s = Strict PWM + (PWM _difference ) × _2/5 ; PWM _3s = Strict PWM + (PWM _difference ) × _3/5 ; PWM _4s = Strict PWM + (PWM _difference ) × _4/5 ; PWM _5s = Strict PWM + (PWM _difference ).

For example, if the severe PWM obtained in step S4 is 60%, it can be regarded as the severe PWM of the previous state. Therefore, the set PWM obtained in step S5 is 71.74%, which can be regarded as the actual PWM in the previous state.

As mentioned above, PWM _1s = Strict PWM + (PWM difference) × 1/5 = 60 + (71.74-60) × 1/5 = 62.348%. In the same way, it is obtained that PWM _2s is 64.696%; PWM _3s is 67.044%; PWM _4s is 69.392%; and PWM _5s is 71.74%.

Step S7: The proportional valve is driven. The proportional valve 111 adjusts the opening percentage of the proportional valve 111 according to the actual control percentage of step S5 or the stepwise control percentage of step S6 to change the flow or pressure of the hydraulic oil output from the pump 11. . The opening degree of the proportional valve 111 is used to control the flow rate or pressure flowing into the cooling fan 120, thereby controlling (changing) the rotation speed of the cooling fan 120, so that the engine 10 obtains a better heat dissipation effect.

To sum up, the present invention is a control percentage obtained by comparing the control percentage of the rotation speed or the ambient temperature with the actual modulation range of the ambient temperature. The proportional valve 111 adjusts the opening degree of the proportional valve 111 according to the control percentage, controls the flow rate or pressure flowing into the cooling fan 120, and changes the rotation speed of the cooling fan 120, so that the engine 10 obtains better heat dissipation effect.

The above is a description of the embodiments of the present invention through specific embodiments. Those with ordinary knowledge in the technical field can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

10‧‧‧ Engine

100‧‧‧engine speed sensor

101‧‧‧Inlet air temperature sensor

11‧‧‧Pump

110‧‧‧fluid temperature sensor

111‧‧‧ proportional valve

112‧‧‧Flow sensor

12‧‧‧cooling unit

120‧‧‧cooling fan

121‧‧‧fan speed controller

13‧‧‧ Thermal Control Unit

S1 ~ S7‧‧‧step

FIG. 1 is a schematic diagram of a vehicle cooling control system according to the present invention. FIG. 2 is a flowchart of a vehicle cooling control method according to the present invention. Figure 3 is a line graph of the percentage effective interval.

Claims (18)

A vehicle cooling control method includes the steps of: obtaining an engine speed, an engine speed sensor sensing the speed of the engine, and providing the speed to a heat dissipation control unit; calculating a control percentage effective interval, and the heat dissipation control unit is based on Find the effective percentage of the control percentage based on the speed; calculate the actual control percentage; the thermal control unit finds the actual control percentage based on the effective percentage of the control percentage; the thermal control unit outputs the actual control percentage and the thermal control unit The actual control percentage is provided to a proportional valve; and the proportional valve is driven, and the proportional valve adjusts the opening degree of the proportional valve according to the actual control percentage to change the flow rate or pressure of hydraulic oil output by a pump. According to the vehicle cooling control method described in the first item of the patent application scope, it further has a step of obtaining the ambient temperature and the water temperature, and an intake air temperature sensor senses the ambient temperature of the engine and provides the cooling control A fluid temperature sensor that senses the water temperature of the cooling water from the engine and provides the water temperature to the heat dissipation control unit. The vehicle cooling control method according to item 2 of the scope of the patent application, wherein in the step of obtaining the ambient temperature and the water temperature, a flow sensor senses the flow rate or pressure of the hydraulic oil output by the pump, and The flow rate or pressure is provided to the heat dissipation control unit. According to the vehicle cooling control method described in item 2 of the scope of patent application, it further has a control percentage for finding the corresponding ambient temperature and water temperature, and the heat dissipation control unit finds the corresponding environment according to the ambient temperature and the water temperature. Control percentage of temperature and control percentage of water temperature. According to the vehicle cooling control method described in item 4 of the scope of the patent application, wherein one of the control percentage of the environmental temperature and the control temperature of the water temperature is large, the larger one is taken as the severe control percentage. According to the vehicle cooling control method described in item 5 of the scope of the patent application, wherein in the step of the thermal control unit outputting the actual control percentage, the thermal control unit obtains a one-time gradual change control percentage based on the severe control percentage, The time-sharing control percentage is provided to the proportional valve. The vehicle cooling control method according to item 6 of the scope of patent application, wherein in the step of driving the proportional valve, the proportional valve adjusts the opening degree of the proportional valve to change the pump according to the time-graded control percentage. Flow or pressure of output hydraulic oil. The vehicle cooling control method described in item 1 of the scope of patent application, wherein the effective range of the control percentage has an upper limit control percentage and a lower limit control percentage, and the actual control percentage is the lower limit control percentage + (upper limit control percentage / 100) × ( Upper control percentage lower control percentage). The vehicle cooling control method as described in item 6 of the scope of patent application, wherein the time-sharing gradual change control percentage is to divide a time section into a plurality of time divisions and find a control percentage in each time division. The vehicle cooling control method described in item 9 of the scope of patent application, wherein the time-sharing gradation control percentage is the control percentage _{equalization time} = strict control percentage + (control percentage _difference ) × Nth equalization time / division number ; N is a constant; control percentage _difference = actual control percentage-severe control percentage. A vehicle cooling control system is suitable for an engine and a pump, the pump system is coupled to a proportional valve, and the vehicle cooling control system includes: an engine speed sensor, which is arranged on the engine; A proportional valve is provided in the pump; a heat dissipation control unit is electrically connected to the engine speed sensor and the pump; an intake air temperature sensor is coupled to the engine and is connected to a signal In the heat dissipation control unit, the intake air temperature sensor senses the ambient temperature of the engine and provides the ambient temperature to the heat dissipation control unit; and a fluid temperature sensor is provided in the engine and signals Connected to the heat dissipation control unit, the fluid temperature sensor senses the water temperature of the engine's cooling water, and provides the water temperature to the heat dissipation control unit; wherein the engine speed sensor senses the engine Rotation speed, and provides the rotation speed to the heat dissipation control unit, and the heat dissipation control unit obtains a control percentage effective interval according to the rotation speed; the heat dissipation control unit obtains a corresponding ring according to the ambient temperature and the water temperature. The control percentage of the temperature and the control percentage corresponding to the water temperature; the heat dissipation control unit obtains an actual control percentage according to the effective range of the control percentage, and provides it to the proportional valve to adjust the opening degree of the proportional valve and change The flow or pressure of the hydraulic oil output by the pump. According to the vehicle cooling control system described in item 11 of the scope of patent application, it further has a cooling unit, and the cooling unit is electrically connected to the heat dissipation control unit. The vehicle cooling control system according to item 12 of the application, wherein the cooling unit has a cooling fan. The vehicle cooling control system according to item 13 of the application, wherein the cooling unit has a fan speed sensor, and the fan speed sensor senses the fan speed of the cooling fan and provides the fan speed to The heat dissipation control unit. If the vehicle cooling control system described in item 11 of the scope of patent application, wherein one of the control percentage of the ambient temperature and the control temperature of the water temperature is large, the larger one is taken as a severe control percentage According to the severe control percentage, the heat dissipation control unit obtains a one-time gradient control percentage. The vehicle cooling control system according to item 15 of the scope of patent application, wherein the time-sharing gradation control percentage is provided to the proportional valve, and the proportional valve controls the opening degree of the proportional valve according to the time-sharing gradation control percentage, and Change the flow or pressure of the hydraulic oil that changes the output of the pump. According to the vehicle cooling control system described in item 12 of the scope of patent application, it further has a flow sensor, and the flow sensor senses the flow or pressure of the output hydraulic oil of the pump, and converts the flow or pressure Provided to the heat dissipation control unit. The vehicle cooling control system according to item 11 of the patent application scope, wherein the pump is a variable flow pump or a variable flow pump and a certain amount of pump system.