Inflation pump temperature protection system of air suspension system

Abstract

The invention discloses an inflation pump temperature protection system of an air suspension system, which comprises a first acquisition module in signal connection with a Hall sensor of a brushless motor; the second acquisition module is in signal connection with a sampling resistor of a first controller of the brushless motor; the third acquisition module is in signal connection with the first controller; the fourth acquisition module is in signal connection with a CAN bus of the vehicle; the calculation module is used for calculating and obtaining the temperature value of the pump head of the inflating pump through a preset calculation model based on the rotating speed, the current, the voltage, the environment temperature, the vehicle speed and the pressure, and the second controller is connected to the first obtaining module, the second obtaining module, the third obtaining module, the fourth obtaining module and the air suspension system. The problem that temperature sensors are respectively arranged at the pump head of the inflating pump and the brushless motor of the adjustable air suspension system of the automobile to monitor the temperature, so that the total cost control of the automobile is not facilitated is solved.

Description

Technical Field

[0001] This invention relates to the field of automotive air suspension technology, and more specifically to an air pump temperature protection system for an air suspension system. Background Technology

[0002] With the development of vehicle electrification and intelligentization, more and more vehicles are equipped with adjustable air suspension systems to improve the driving experience. Adjustable air suspension systems can adjust the damping stiffness and vehicle height by changing the volume of gas inside the air springs. At high speeds, the adjustable air suspension system automatically lowers the vehicle height to reduce wind resistance and improve handling and stability; when driving on bumpy roads, it automatically raises the vehicle height to improve ground clearance and allow the vehicle to handle road conditions more easily.

[0003] Generally speaking, an adjustable air suspension system mainly consists of seven components: suspension controller, air tank, air pump, vehicle height sensor, air spring assembly (for the front wheels, including air springs and shock absorbers), shock absorbers and air springs (for the rear wheels), and distribution valve.

[0004] The air pump is the core component of the entire air suspension system, consisting of a pump head and a motor. The motor drives the piston inside the pump head to compress the intake air at normal pressure into high-pressure air to supply air to the air tank / air springs.

[0005] Currently, the electrical interfaces of traditional air pumps are as follows: Figure 1 As shown: 4.1 and 4.2 are the power inputs for the air pump, connected to the suspension controller. The suspension controller controls the operation and shutdown of the air pump based on the vehicle's posture and the dynamic management requirements during vehicle operation.

[0006] 5.1 and 5.2 are the solenoid valve control signal input interfaces, which are connected to the suspension controller. The suspension controller controls the opening (to exhaust air via the air pump) and closing (to maintain air tank pressure) of the solenoid valves according to the vehicle's posture and the dynamic management requirements during vehicle operation.

[0007] 6.1 and 6.2 are temperature sensor signal output interfaces, connected to the suspension controller. Based on the current temperature sensor value, the suspension controller decides whether to continue inflating or stop the pump to allow it to cool down and rest, protecting the pump from burning out.

[0008] Each air pump manufacturer sets a temperature protection threshold based on its own heat resistance. When the suspension controller detects that the current air pump temperature exceeds 105℃, it immediately stops pumping air and only allows the air pump to resume operation after the temperature sensor value drops below 80℃.

[0009] Typically, temperature sensors are placed at critical heat-generating parts of the air pump (such as the area closest to the piston) to directly detect the pump's current temperature, determining whether it's functioning properly or needs to be shut down for cooling. This temperature sensor usually consists of more than ten components, including an NTC thermistor, a metal thermally conductive housing, wiring harness, connector, waterproof cover, and sealing plug, costing approximately 20-30 yuan. On the other hand, some brushless motor air pumps have a built-in temperature sensor in their brushless motor controller. In the current cost-sensitive automotive industry, placing a temperature sensor at a critical point of piston movement is clearly redundant and detrimental to overall vehicle cost control.

[0010] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0011] To overcome the shortcomings of existing technologies, a temperature protection system for the air pump of an air suspension system is provided to address the problem that installing temperature sensors at the pump head and brushless motor of the adjustable air suspension system in automobiles is not conducive to the overall cost control of the vehicle.

[0012] To achieve the above objectives, an air pump temperature protection system for an air suspension system is provided, comprising: A first acquisition module for acquiring the rotational speed of the brushless motor of the air pump in the air suspension system is connected to the Hall sensor of the brushless motor. A second acquisition module for acquiring the current of the brushless motor is connected to the sampling resistor of the first controller of the brushless motor. A third acquisition module for acquiring the voltage of the brushless motor is connected to the first controller. A fourth acquisition module is used to acquire ambient temperature, vehicle speed of the vehicle where the air pump is located, and pressure of the air tank. The signal is connected to the vehicle's CAN bus. A calculation module for calculating the temperature value of the air pump head based on the rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure using a preset calculation model is connected to the first acquisition module, the second acquisition module, the third acquisition module, the fourth acquisition module, and the second controller of the air suspension system.

[0013] Furthermore, the calculation model is as follows: W1 + W2 = Q2 + Q3; Where W1 is the heat generated by compressed air, calculated by W1=c×m×(T2-T1), where c is the homogeneous specific heat capacity of the air pump, m is the mass of the air pump, T1 is the ambient temperature, and T2 is the temperature of the compressed air. W2 is the heat generated by friction during the piston movement of the pump head, which is calculated by W2=n×Wf, where n is the number of revolutions of the brushless motor and Wf is the work done by friction during piston movement. Q2 is the temperature rise of the air pump, which can be calculated using Q2=c×m×ΔT, where ΔT is the temperature difference of the air pump. Q3 represents the heat dissipation of the air pump, calculated as Q3 = K × A × The calculation is as follows: A is the heat transfer and heat transfer area of ​​the air pump, K is the comprehensive heat dissipation coefficient of the air pump, ΔT1 is the temperature difference between the two media, and dt is the heat dissipation time of the air pump.

[0014] Furthermore, the temperature of the compressed air is: T1; Where P2 is the absolute pressure of the compressed air; P1 is the absolute pressure of the air before compression; γ is the specific heat ratio of air.

[0015] Furthermore, the work done by friction during piston movement is: Wf = Fs × h; Where Fs is the frictional force during the piston's movement; h represents the piston stroke.

[0016] Furthermore, the frictional force during piston movement is: Fs = μ × Fn; Where μ is the friction coefficient between the piston and the cylinder, and Fn is the normal pressure of the piston relative to the cylinder, which is calculated using the rotational speed and the current.

[0017] This invention provides a method for protecting the temperature of an air pump in an air suspension system, comprising the following steps: The first acquisition module signal is connected to the Hall sensor of the brushless motor to acquire the speed of the brushless motor of the air pump of the air suspension system. The second acquisition module signal is connected to the sampling resistor of the first controller of the brushless motor to obtain the current of the brushless motor; The third acquisition module signal is connected to the first controller to obtain the voltage of the brushless motor; The fourth acquisition module signal is connected to the vehicle's CAN bus to obtain the ambient temperature, the vehicle speed of the vehicle where the air pump is located, and the pressure of the air tank. Based on the rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure, the calculation module calculates the temperature value of the air pump head using a preset calculation model and sends it out. The second controller of the air suspension system receives the temperature value of the pump head of the air pump and controls the start and stop of the air pump based on the over-temperature protection trigger threshold and the recovery temperature.

[0018] The beneficial effects of this invention are that the air pump temperature protection system of the air suspension system of this invention achieves communication with the vehicle's CAN / LIN through a brushless motor air pump to obtain information such as the vehicle's ambient temperature and speed. The system calculates the operating temperature of the air pump through a calculation model, thereby achieving overheat protection. The air pump temperature protection system of this invention does not require an external NTC temperature sensor, i.e., it eliminates the need for redundant temperature sensors at the piston of the pump head, saving costs. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is an electrical interface diagram of the air pump in the air suspension system according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the air pump temperature protection system of the air suspension system according to an embodiment of the present invention.

[0021] Figure 3 This is a comparison chart of the calculated active air pump temperature and the air pump temperature directly obtained by the temperature sensor in the air suspension system of this embodiment of the invention.

[0022] Figure label: First acquisition module 1; Second acquisition module 2; Third acquisition module 3; Fourth acquisition module 4; Calculation module 5; 6. Brushless motor; 61. Hall sensor; 62. First controller; Second controller 7; CAN bus 8. Detailed Implementation

[0023] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Reference Figure 2 As shown, the present invention provides an air pump temperature protection system for an air suspension system, including a first acquisition module 1, a second acquisition module 2, a third acquisition module 3, a fourth acquisition module 4, and a calculation module 5.

[0026] The first acquisition module 1 is used to acquire the rotational speed of the brushless motor 6 of the air pump in the air suspension system. The signal of the first acquisition module 1 is connected to the Hall sensor 61 of the brushless motor 6.

[0027] In this embodiment, the brushless motor is equipped with three Hall sensors. The three Hall sensors are arranged with a 120° electrical angle difference for commutation positioning, motor speed calculation, and speed control of the brushless motor. They can also serve as input signals for the calculation model.

[0028] The second acquisition module 2 is used to acquire the current of the brushless motor 6. The signal of the second acquisition module 2 is connected to the sampling resistor of the first controller 62 of the brushless motor 6.

[0029] In this embodiment, the first controller of the brushless motor is equipped with a sampling resistor to collect the bus current, which is used to realize overload protection and torque control of the motor. It can also serve as the input signal for the calculation model.

[0030] The third acquisition module 3 is used to acquire the voltage of the brushless motor 6. The signal of the third acquisition module 3 is connected to the first controller 62.

[0031] In this embodiment, the first controller of the brushless motor 6 performs real-time diagnosis and feedback on the system's power supply voltage. Simultaneously, it can serve as the input signal for the computational model.

[0032] The fourth acquisition module 4 is used to acquire ambient temperature, vehicle speed of the vehicle where the air pump is located, and air tank pressure. The signal of the fourth acquisition module 4 is connected to the vehicle's CAN bus 8.

[0033] In this embodiment, the ambient temperature information can be obtained from the external CAN bus and can be used as the basic input signal for the calculation model.

[0034] The vehicle speed information and ambient temperature can be obtained from the external CAN bus and can be used as the basic input signal for the calculation model.

[0035] The gas tank pressure information and ambient temperature can be obtained from the external CAN bus and can be used as the basic input signal for the calculation model.

[0036] The calculation module 5 is used to calculate the temperature value of the air pump head based on rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure using a preset calculation model. The calculation module 5 is connected to the first acquisition module 1, the second acquisition module 2, the third acquisition module 3, the fourth acquisition module 4, and the second controller 7 of the air suspension system.

[0037] After receiving the temperature value of the air pump head sent by the calculation module, the second controller 7 of the air suspension system controls the start and stop of the air pump based on the over-temperature protection trigger threshold and the recovery temperature.

[0038] Specifically, after receiving the temperature value of the air pump head sent by the computing module, the second controller 7 decides whether to continue pumping air or stop the pump to cool down and rest, protecting the air pump from burning out. When the second controller determines that the current temperature of the air pump exceeds 105℃, it immediately stops pumping air and only allows the air pump to resume operation after the temperature value of the air pump drops below 80℃.

[0039] In this embodiment, the calculation model is as follows: W1 + W2 = Q2 + Q3; Where W1 is the heat generated by compressed air, calculated by W1=c×m×(T2-T1), where c is the homogeneous specific heat capacity of the air pump, m is the mass of the air pump, T1 is the ambient temperature, and T2 is the temperature of the compressed air.

[0040] In calculating the heat W1 generated by compressed air, the isentropic analysis formula for the compression process is used: ; Where T1 is the air temperature before compression, i.e., the ambient temperature, which can be obtained through the CAN bus; T2 is the absolute temperature (K) after compression, which is the value we need to solve for; P2 is the absolute pressure of the compressed air, which can be obtained via the CAN bus; P1 is the absolute pressure of the air before compression, which can be obtained via the CAN bus; γ is the specific heat capacity of air, also known as the adiabatic index, which is a constant.

[0041] The air before compression is atmospheric pressure air. The compressed air is air that has been compressed by the compressor. The gas in the air tank is the compressed air from the compressor that is pumped into the air tank through the distribution valve. Gas can only be pumped into the air tank if the pressure of the compressed air is greater than the pressure of the air tank.

[0042] The temperature of the compressed air is: T1.

[0043] The heat W1 that the air itself gains during compression can be calculated using the heat formula: W1 = c × m × (T2 - T1); Where W1 represents the change in the internal energy of the air, which is the work / heat energy absorbed by the air during compression, and the unit is joules (J).

[0044] m is the mass of air, measured in kilograms (kg), and is a constant.

[0045] c is the constant specific heat capacity of air.

[0046] T2-T1 represents the temperature difference of the air before and after compression, measured in Kelvin (K).

[0047] W2 is the heat generated by friction during the piston movement of the pump head, calculated by W2=n×Wf, where n is the number of revolutions of the brushless motor 6, and Wf is the work done by friction during piston movement.

[0048] In the calculation of the heat W2 generated by friction during piston movement, the work done by friction during piston movement is equivalent to the heat W2 generated.

[0049] The frictional force Fs is: Fs = μ × Fn; Where μ is the friction coefficient between the piston and the cylinder, which varies with temperature and can be obtained through calibration; Fn is the normal force of the piston relative to the cylinder, which comes from the motor torque and can be determined by the speed and current.

[0050] The work done by friction, Wf, is: Wf = Fs × h; Where h is the piston stroke, which is constant.

[0051] The total heat generated by friction is: W2 = n × Wf; Where n is the number of revolutions of the brushless motor, obtained through a Hall sensor.

[0052] Q2 represents the temperature rise of the air pump, calculated using Q2=c×m×ΔT, where ΔT is the temperature difference of the air pump.

[0053] When calculating the temperature rise Q2 of the air pump, if the air pump is defined as a homogeneous object, then according to the heat formula: Q2 = c × m × △T; Where c is the homogeneous specific heat capacity of the air pump, which is obtained through calibration; m is the mass of the air pump, a constant; ΔT represents the temperature difference change of the air pump, which is the quantity that needs to be calculated.

[0054] Q3 represents the heat dissipation of the air pump, calculated as Q3 = K × A × The calculation is as follows: A is the heat transfer and heat transfer area of ​​the air pump, K is the comprehensive heat dissipation coefficient of the air pump, ΔT1 is the temperature difference between the two media, and dt is the heat dissipation time of the air pump.

[0055] When calculating the heat dissipation Q3 of the air pump, the current temperature calculation is the same as before. The air pump is defined as a homogeneous object of equal mass. According to Newton's law of heat dissipation: Q3=K×A× t; Where A represents the heat transfer capacity and the heat transfer area; K is the overall heat dissipation coefficient; △T1 represents the temperature difference between the two media; dt is the heat dissipation time.

[0056] Based on the calculation model W1+W2=Q2+Q3, the calculation module can calculate △T to deduce the actual temperature value of the pump head of the air pump.

[0057] In actual implementation, although many parameters are constants, they cannot be obtained theoretically but can be obtained through calibration.

[0058] In this embodiment, calibration is used to obtain the following: Figure 3 The conclusion is that, under various operating conditions, the actual temperature value of the air pump head calculated by the calculation module is very close to the temperature value obtained directly from the external NTC, but slightly higher. This ensures the accuracy of the temperature detected by the software, preventing the motor from burning out due to high temperature, while also leaving a certain margin to prevent excessively high temperatures when the temperature protection is triggered. Typically, the over-temperature protection trigger threshold T1' of the external temperature sensor is 105℃, and the recovery temperature T2' is 80℃; while the second controller of the air suspension system has a preset overheat protection trigger threshold T1 set to 110℃ and a recovery temperature T2 set to 85℃, which allows for normal overheat protection of the air pump.

[0059] This invention provides a method for protecting the temperature of an air pump in an air suspension system, comprising the following steps: S1, the first acquisition module signal is connected to the Hall sensor of the brushless motor to acquire the speed of the brushless motor of the air pump of the air suspension system.

[0060] S2, The second acquisition module signal is connected to the sampling resistor of the first controller of the brushless motor to obtain the current of the brushless motor.

[0061] S3, the third acquisition module signal is connected to the first controller to obtain the voltage of the brushless motor.

[0062] S4, the fourth acquisition module signal is connected to the vehicle's CAN bus to obtain ambient temperature, vehicle speed of the vehicle where the air pump is located, and air tank pressure.

[0063] S5. Based on rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure, the calculation module calculates the temperature value of the air pump head through a preset calculation model and sends it out.

[0064] S6. The second controller of the air suspension system receives the temperature value of the pump head of the air pump and controls the start and stop of the air pump based on the over-temperature protection trigger threshold and the recovery temperature (T2).

[0065] In the entire air pump system, the brushless motor and pump head are the most temperature-sensitive parts and require thermal protection at the system level.

[0066] The thermal protection scheme for the brushless motor air pump consists of two parts: Firstly, the onboard NTC of the first controller of the brushless motor is used to realize the controller's own thermal protection; Secondly, by obtaining the working status of the air pump, the pump head temperature is calculated using a computational model to achieve thermal protection of the pump head.

[0067] Both the controller and the pump head have their own temperature protection thresholds. If either one reaches the threshold, the thermal protection strategy will be activated, stopping the air pump from running until the temperature drops below the specified value before the air pump can be restarted.

[0068] The air pump temperature protection system of this invention uses a brushless motor air pump to communicate with the vehicle's CAN / LIN system, obtaining information such as the vehicle's ambient temperature and speed. The system calculates the operating temperature of the air pump using a computational model, thereby achieving overheat protection. This air pump temperature protection system eliminates the need for an external NTC temperature sensor, thus avoiding redundant temperature sensor placement at the pump head piston and saving costs.

[0069] The vehicle can obtain key information about the air pump in real time through CAN / LIN communication, such as whether the air pump is working properly, whether a fault has occurred, and what kind of fault it is.

[0070] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A temperature protection system for an air pump in an air suspension system, characterized in that, include: A first acquisition module for acquiring the rotational speed of the brushless motor of the air pump in the air suspension system is connected to the Hall sensor of the brushless motor. A second acquisition module for acquiring the current of the brushless motor is connected to the sampling resistor of the first controller of the brushless motor. A third acquisition module for acquiring the voltage of the brushless motor is connected to the first controller. A fourth acquisition module is used to acquire ambient temperature, vehicle speed of the vehicle where the air pump is located, and pressure of the air tank. The signal is connected to the vehicle's CAN bus. A calculation module for calculating the temperature value of the air pump head based on the rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure using a preset calculation model is connected to the first acquisition module, the second acquisition module, the third acquisition module, the fourth acquisition module, and the second controller of the air suspension system.

2. The air pump temperature protection system for the air suspension system according to claim 1, characterized in that, The calculation model is as follows: W1 + W2 = Q2 + Q3; Where W1 is the heat generated by compressed air, calculated by W1=c×m×(T2-T1), where c is the homogeneous specific heat capacity of the air pump, m is the mass of the air pump, T1 is the ambient temperature, and T2 is the temperature of the compressed air. W2 is the heat generated by friction during the piston movement of the pump head, which is calculated by W2=n×Wf, where n is the number of revolutions of the brushless motor and Wf is the work done by friction during piston movement. Q2 is the temperature rise of the air pump, which can be calculated using Q2=c×m×ΔT, where ΔT is the temperature difference of the air pump. Q3 represents the heat dissipation of the air pump, calculated as Q3 = K × A × The calculation is as follows: A is the heat transfer and heat transfer area of ​​the air pump, K is the comprehensive heat dissipation coefficient of the air pump, ΔT1 is the temperature difference between the two media, and dt is the heat dissipation time of the air pump.

3. The air pump temperature protection system for the air suspension system according to claim 2, characterized in that, The temperature of the compressed air is: T1； Where P2 is the absolute pressure of the compressed air; P1 is the absolute pressure of the air before compression; γ is the specific heat ratio of air.

4. The air pump temperature protection system for the air suspension system according to claim 2, characterized in that, The work done by friction during piston movement is: Wf = Fs × h; Where Fs is the frictional force during the piston's movement; h represents the piston stroke.

5. The air pump temperature protection system for the air suspension system according to claim 4, characterized in that, The frictional force during piston movement is: Fs = μ × Fn; Where μ is the friction coefficient between the piston and the cylinder, and Fn is the normal force of the piston relative to the cylinder, which is calculated using the rotational speed and the current.

6. A method for protecting the temperature of an air pump in an air suspension system employing the air pump temperature protection system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The first acquisition module signal is connected to the Hall sensor of the brushless motor to acquire the speed of the brushless motor of the air pump of the air suspension system. The second acquisition module signal is connected to the sampling resistor of the first controller of the brushless motor to obtain the current of the brushless motor; The third acquisition module signal is connected to the first controller to obtain the voltage of the brushless motor; The fourth acquisition module signal is connected to the vehicle's CAN bus to obtain the ambient temperature, the vehicle speed of the vehicle where the air pump is located, and the pressure of the air tank. Based on the rotational speed, current, voltage, ambient temperature, vehicle speed, and pressure, the calculation module calculates the temperature value of the air pump head using a preset calculation model and sends it out. The second controller of the air suspension system receives the temperature value of the pump head of the air pump and controls the start and stop of the air pump based on the over-temperature protection trigger threshold and the recovery temperature.

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