Vehicular controller

Abstract

To provide a vehicular controller capable of suppressing generation of noise.SOLUTION: A vehicle control device comprises: a detection unit that detects that air has entered a cooling water passage connected to an internal combustion engine and a component; and a flow control unit that, when the entry of the air is detected, increases a flow rate of cooling water in the cooling water passage compared to before the entry of the air is detected.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle.

Background Art

[0002] The cooling water of an internal combustion engine circulates between the internal combustion engine and components such as a heater core (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When air enters the cooling water passage, abnormal noises may occur. Accordingly, an object of the present invention is to provide a vehicle control device capable of suppressing the occurrence of abnormal noises.

Means for Solving the Problems

[0005] The above object can be achieved by a vehicle control device including: a detection unit configured to detect that air has entered a cooling water passage connected to an internal combustion engine and components; and a flow rate control unit configured to increase a flow rate of cooling water in the cooling water passage when the detection of the air entry is made, as compared with before the detection of the air entry.

[0006] The detection unit may detect that air has entered based on a frequency of a sound generated in the cooling water passage.

[0007] The detection unit may detect that air has entered based on a magnitude of a sound generated in the cooling water passage.

[0008] The detection unit may detect the mixing of the air based on the pressure in the cooling water passage.

[0009] The detection unit may detect the mixing of the air based on the vibration of the cooling water passage.

Advantages of the Invention

[0010] It is possible to provide a vehicle control device capable of suppressing the generation of abnormal noise.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the vehicle control device of the present embodiment will be described with reference to the drawings. However, in the drawings, the dimensions, ratios, etc. of each part may not be illustrated so as to exactly match the actual ones. Also, depending on the drawings, details may be omitted.

[0013] <First Embodiment> FIG. 1 is a schematic diagram illustrating a cooling device 100 for an internal combustion engine. The internal combustion engine 10 is a gasoline engine, a diesel engine, etc., burns fuel, and generates driving force. The internal combustion engine 10 has a water jacket 11.

[0014] The cooling device 100 cools the internal combustion engine 10. The cooling device 100 has a water pump 12, a thermostat 14, a radiator 16, a heater core 18, and a plurality of cooling water passages. The cooling water flows through the cooling water passages and circulates between the internal combustion engine 10 and the components.

[0015] One end of the cooling water passage 20 is connected to the water jacket 11 of the internal combustion engine 10. The other end of the cooling water passage 20 is connected to the radiator 16. One end of the cooling water passage 21 is connected to the radiator 16. The other end of the cooling water passage 21 is connected to the water pump 12. A thermostat 14 is provided in the middle of the cooling water passage 21. The cooling water passage 22 is connected between the cooling water passage 20 and the thermostat 14.

[0016] The cooling water passage 24 is connected between the cooling water passage 20 and the thermostat 14. One end of the cooling water passage 24 is connected upstream of the portion of the cooling water passage 20 to which the cooling water passage 22 is connected. The other end of the cooling water passage 24 is connected to the thermostat 14. A heater core 18 is provided in the middle of the cooling water passage 24.

[0017] By driving the water pump 12, the cooling water is supplied to the water jacket 11. The internal combustion engine 10 is cooled by the cooling water. The cooling water flows out from the water jacket 11 into the cooling water passage 20. The cooling water flows through the cooling water passage 20 and is supplied to the radiator 16. In the radiator 16, the heat of the cooling water is released and the temperature of the cooling water decreases. The cooling water cooled by the radiator 16 flows through the cooling water passage 21 and circulates back to the water jacket 11.

[0018] A part of the cooling water in the cooling water passage 20 flows through the cooling water passage 22 and circulates without passing through the radiator 16. A part of the cooling water flows from the cooling water passage 20 into the cooling water passage 24 and is supplied to the heater core 18. The heater core 18 is a heat exchanger for vehicle heating. The cooling water exchanges heat in the heater core 18. The opening degree of the thermostat 14 changes according to the temperature of the cooling water. The flow of the cooling water is controlled by the opening degree.

[0019] When air mixes into the cooling water passage, abnormal noise (air flow noise) may occur. For example, when air mixes into the cooling water passage 24, abnormal noise is generated from the cooling water passage 24.

[0020] The cooling device 100 includes a frequency sensor 30, a volume sensor 32, a pressure sensor 34, and a vibration sensor 36. The frequency sensor 30 and the volume sensor 32 are provided, for example, near the cooling water passage 24. The frequency sensor 30 detects the frequency of the sound generated in the cooling water passage 24. The volume sensor 32 detects the loudness of the sound. The pressure sensor 34 is attached to the cooling water passage 24 and detects the pressure inside the cooling water passage 24. The vibration sensor 36 is attached to the cooling water passage 24 and detects the vibration of the cooling water passage 24.

[0021] The ECU (Electronic Control Unit) 40 functions as a control device for the vehicle. The ECU 40 includes an arithmetic device such as a CPU (Central Processing Unit), and storage devices such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The ECU 40 performs various controls by executing programs stored in the ROM and the storage device.

[0022] The ECU 40 functions as a detection unit 42 and a flow rate control unit 44. The ECU 40 acquires the frequency detected by the frequency sensor 30, the volume detected by the volume sensor 32, the pressure detected by the pressure sensor 34, and the vibration detected by the vibration sensor 36. The detection unit 42 detects the mixing of air based on the frequency and the like. The flow rate control unit 44 controls the flow rate of the cooling water. Specifically, the flow rate control unit 44 controls the duty ratio of the signal output to the water pump 12 and changes the rotation speed of the water pump 12. The flow rate of the cooling water is adjusted by the rotation speed. For example, when the duty ratio increases, the rotation speed of the water pump 12 increases, and the flow rate of the cooling water increases.

[0023] FIG. 2 is a flowchart exemplifying the processing in the first embodiment. The detection unit 42 determines whether or not it has detected the mixing of air into the cooling water (step S10). In the first embodiment, the detection unit 42 acquires the frequency from the frequency sensor 30 and performs detection based on the frequency. More specifically, if the frequency is equal to or less than the threshold value, it is presumed to be mixed.

[0024] If the determination in step S10 is negative (No), step S10 is repeated. If the determination is affirmative (Yes), the flow rate control unit 44 increases the rotation speed of the water pump 12 and increases the flow rate of the cooling water in the cooling water passage 24 as compared with before the detection of air mixing (step S12). The processing ends here.

[0025] FIG. 3(a) is a diagram exemplifying the frequency of sound. The horizontal axis represents time. The vertical axis represents the frequency of the sound generated in the cooling water passage 24. A threshold value X1 is defined for the frequency. When no air is mixed into the cooling water passage 24, the frequency is higher than X1. The detection unit 42 makes a negative determination in step S10 of FIG. 2. When air is mixed, abnormal noise is generated and the frequency changes. As between time t1 and t2 in FIG. 3(a), the frequency becomes equal to or less than X1. The detection unit 42 makes an affirmative determination in step S10. The flow rate control unit 44 increases the flow rate of the cooling water. Due to the increase in the flow rate of the cooling water, air is discharged from the cooling water passage 24. As after time t2, the frequency of the sound returns to a value higher than X1. The flow rate control unit 44 decreases the flow rate.

[0026] According to the first embodiment, the detection unit 42 detects the mixing of air based on the frequency of the sound generated in the cooling water passage 24. When the mixing of air is detected, the flow rate control unit 44 increases the flow rate of the cooling water. Since the flow rate of the cooling water increases, air is discharged from the cooling water passage 24. In order to discharge air in response to the detection of abnormal noise, the generation time of the abnormal noise is shortened. The generation of abnormal noise due to the mixing of air can be suppressed.

[0027] The ECU 40 stores a threshold value X1 for the frequency of the sound. When a low-frequency abnormal sound occurs, air ingress can be detected. During the period when the frequency is below X1, the flow control unit 44 increases the flow rate of the cooling water. That is, the flow rate remains increased until the frequency returns to a higher frequency than X1. In other words, the flow rate remains high until the air is discharged. The air can be effectively discharged. Threshold values may be set not only on the low-frequency side but also on the high-frequency side. Whether the frequency of the abnormal sound is high or low, detection is possible.

[0028] By improving the cooling water passage, the abnormal sound can be suppressed. However, the cooling water passage becomes larger in size and the cost also increases. According to the first embodiment, the abnormal sound is suppressed by increasing the flow rate of the cooling water. The enlargement of the cooling water passage and the cost increase are suppressed.

[0029] In the following second to fourth embodiments, the configuration of FIG. 1 is common and the processing of FIG. 2 is also performed.

[0030] <Second Embodiment> FIG. 3(b) is a diagram illustrating the magnitude of the sound. The horizontal axis represents time. The vertical axis represents the magnitude of the sound (noise value, sound pressure). A threshold value Y is defined for the noise value. When air is mixed in, an abnormal sound is generated and the noise value increases. Between time t3 and t4, the noise value is equal to or greater than the threshold value Y.

[0031] In step S10 of FIG. 2, the detection unit 42 determines whether the magnitude (sound pressure) of the sound generated from the cooling water passage 24 is equal to or greater than the threshold value Y. In the case of a negative determination, step S10 is repeated. In the case of an affirmative determination, the flow control unit 44 increases the flow rate of the cooling water.

[0032] According to the second embodiment, the detection unit 42 detects air ingress based on the magnitude of the sound generated in the cooling water passage 24. When air ingress is detected, the flow control unit 44 increases the flow rate of the cooling water. By increasing the flow rate of the cooling water, the air is discharged from the cooling water passage 24. The generation of abnormal sounds due to air ingress can be suppressed.

[0033] <Third Embodiment> FIG. 4(a) is a diagram illustrating pressure. The horizontal axis represents time. The vertical axis represents the pressure in the cooling water passage 24. A threshold value Pth is defined for the pressure. At time t5, the pressure is equal to or higher than Pth. The pressure changes due to the mixing of air. From time t6 to t7, the pressure may become equal to or lower than the threshold value Pth.

[0034] In step S10 of FIG. 2, the detection unit 42 determines whether the pressure in the cooling water passage 24 is equal to or higher than the threshold value Pth. In the case of a negative determination, step S10 is repeated. In the case of an affirmative determination, the flow rate control unit 44 increases the flow rate of the cooling water.

[0035] According to the third embodiment, the detection unit 42 detects the mixing of air based on the pressure in the cooling water passage 24. When the mixing of air is detected, the flow rate control unit 44 increases the flow rate of the cooling water. By increasing the flow rate of the cooling water, the air is discharged from the cooling water passage 24. The generation of abnormal noise due to the mixing of air can be suppressed.

[0036] <Fourth Embodiment> FIG. 4(b) is a diagram illustrating vibration. The horizontal axis represents time. The vertical axis represents the vibration generated in the cooling water passage 24. Frequencies f1 and f2 are shown as the frequencies of the vibration. f2 is higher than f1. When the cooling water is flowing without the mixing of air, the cooling water passage 24 vibrates at the frequency f1. When air is mixed into the cooling water, the frequency of the vibration changes and becomes f2 as from time t8 to t9.

[0037] In step S10 of FIG. 2, the detection unit 42 determines whether the frequency of the vibration in the cooling water passage 24 is equal to or higher than a predetermined value. The predetermined value is higher than f1 and lower than f2. In the case of a negative determination, step S10 is repeated. When a frequency higher than the predetermined value such as f2 is generated, the determination in step S10 is affirmative. In the case of an affirmative determination, the flow rate control unit 44 increases the flow rate of the cooling water.

[0038] According to the fourth embodiment, the detection unit 42 detects the air entrainment based on the frequency of the vibration of the cooling water passage 24. When the air entrainment is detected, the flow rate control unit 44 increases the flow rate of the cooling water. By increasing the flow rate of the cooling water, the air is discharged from the cooling water passage 24. The generation of abnormal noise due to the air entrainment can be suppressed.

[0039] The detection unit 42 only needs to be able to detect that air has been entrained. For detection, the frequency of sound, the magnitude of sound, pressure, and the frequency of vibration may be used, or other quantities may be used, or two or more quantities may be used.

[0040] In the above example, the air entrainment in the cooling water passage 24 is detected. The air entrainment in other cooling water passages may also be detected. The cooling water may flow through components other than the radiator 16 and the heater core 18.

[0041] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of Reference Numerals

[0042] 10 Internal combustion engine, 11 Water jacket, 12 Water pump, 14 Thermostat, 16 Radiator, 18 Heater core, 20, 21, 22, 24 Cooling water passages, 30 Frequency sensor, 32 Volume sensor, 34 Pressure sensor, 36 Vibration sensor, 40 ECU, 42 Detection unit, 44 Flow rate control unit

Claims

1. A detection unit that detects that air has entered a cooling water passage connected to the internal combustion engine and the component; a flow rate control unit that, when the intrusion of air is detected, increases a flow rate of the cooling water in the cooling water passage compared to a flow rate before the intrusion of air is detected.

2. 2. The vehicle control device according to claim 1, wherein the detection unit detects the intrusion of the air based on a frequency of a sound generated in the cooling water passage.

3. The vehicle control device according to claim 1 , wherein the detection unit detects the intrusion of the air based on a volume of a sound generated in the cooling water passage.

4. The vehicle control device according to claim 1 , wherein the detection unit detects the intrusion of the air based on a pressure in the cooling water passage.

5. The vehicle control device according to claim 1 , wherein the detection unit detects the intrusion of the air based on vibration of the cooling water passage.

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