vehicle

Abstract

This vehicle includes: an internal combustion engine; and auxiliary equipment for cooling the internal combustion engine. The vehicle also includes: a detection device for detecting the height of the water surface of water surrounding the vehicle; and a control device that, if the height of the water surface becomes higher than a predetermined first threshold value, changes an output value of the auxiliary equipment to a second output value smaller than a first output value until the output value becomes higher than the first threshold value.

Description

Technical Field

[0001] The present disclosure relates to a vehicle.

Background Art

[0002] Vehicles equipped with an internal combustion engine and auxiliary equipment for cooling the internal combustion engine are widely known. Examples of the auxiliary equipment for cooling the internal combustion engine include a radiator fan (see Patent Document 1) and a cooling water pump (see Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the vehicle is immersed in water and the internal combustion engine is immersed in water, the cooling of the internal combustion engine progresses, so the output value of the auxiliary equipment for cooling the internal combustion engine can be made smaller than before the internal combustion engine is immersed in water. Thereby, if the output value of the auxiliary equipment for cooling the internal combustion engine is made smaller than before the internal combustion engine is immersed in water, it becomes possible to save the energy for driving the auxiliary equipment.

[0005] In view of the above circumstances, at least one embodiment of the present invention aims to provide a vehicle capable of saving the energy for driving the auxiliary equipment.

Means for Solving the Problems

[0006] (1) A vehicle according to at least one embodiment of the present invention is a vehicle comprising an internal combustion engine and an auxiliary machine for cooling the internal combustion engine, the vehicle comprising a detection device for detecting the height of the water surface around the vehicle, and a control device that, when the height of the water surface rises above a predetermined first threshold, changes the output value of the auxiliary machine to a second output value that is smaller than the first output value that rises above the first threshold.

[0007] According to the configuration described in (1) above, when the water level around the vehicle rises above the first threshold, it is determined that the internal combustion engine is likely to be cooled by the water around the vehicle, and the output value of the auxiliary equipment is changed from the first output value to a second output value which is smaller than the first output value. This makes it possible to save energy for operating the auxiliary equipment.

[0008] (2) In some embodiments, in the configuration of (1) above, the auxiliary equipment includes a radiator fan, and the control device reduces the rotational speed of the radiator fan as the water level rises when the water level rises above the first threshold.

[0009] According to the configuration described in (2) above, the rotational speed of the radiator fan decreases as the water level rises. As the water level rises, the radiator fan is submerged in the water surrounding the vehicle, which is likely to increase the driving resistance of the radiator fan. However, by reducing the rotational speed of the radiator fan as the water level rises, energy required to operate the radiator fan can be saved.

[0010] (3) In some embodiments, in the configuration of (1) above, the auxiliary equipment includes a radiator fan and a coolant pump, and the control device changes the rotational speed of the radiator fan to a second rotational speed which is less than the first rotational speed until the water level rises above the first threshold when the water level rises above the first threshold, and changes the rotational speed of the coolant pump to a fourth rotational speed which is less than the third rotational speed until the water level rises above the second threshold when the water level rises above a second threshold which is predetermined to be higher than the first threshold.

[0011] According to the configuration described in (3) above, when the water level rises above the first threshold, the rotational speed of the radiator fan, which is affected by the water level's driving resistance, is reduced before that of the coolant pump. Furthermore, when the water level rises above the second threshold, which is higher than the first threshold, the rotational speed of the coolant pump is also reduced. This allows for more effective energy savings for both the radiator fan and the coolant pump.

[0012] (4) In some embodiments, in the configuration of (3) above, the auxiliary equipment includes an oil pump, and the control device changes the rotational speed of the oil pump to a sixth rotational speed which is less than the fifth rotational speed at which the water level rises above the third threshold when the water level rises above a third threshold which is predetermined to be higher than the second threshold.

[0013] According to the configuration described in (4) above, when the water level rises above the third threshold (which is higher than the second threshold), the rotational speed of the oil pump is reduced. In other words, the reduction in the rotational speed of the oil pump, which affects the fuel efficiency of the internal combustion engine, is delayed compared to the reduction in the rotational speeds of the radiator fan and coolant pump. This allows for more effective energy saving for both the radiator fan and coolant pump, as well as the oil pump, thereby suppressing the deterioration of the fuel efficiency of the internal combustion engine. [Effects of the Invention]

[0014] According to at least one embodiment of the present invention, energy for operating auxiliary equipment can be saved. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the mechanical configuration of the vehicle according to Embodiment 1. [Figure 2] Figure 1 is a block diagram that schematically shows the control configuration of the vehicle. [Figure 3]It is a flowchart schematically showing the control operation of the vehicle shown in FIG. 1. [Figure 4] It is a flowchart schematically showing the control operation of the vehicle shown in FIG. 1. [Figure 5] It is a flowchart showing the operation of the vehicle according to Embodiment 2. [Figure 6] It is a diagram showing an example of a first threshold value, a second threshold value, and a third threshold value. [Mode for Carrying Out the Invention]

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0017] [Embodiment 1] [Mechanical Configuration of Vehicle] FIG. 1 is a configuration diagram schematically showing the mechanical configuration of a vehicle 1A according to Embodiment 1. As shown in FIG. 1, the vehicle 1A according to Embodiment 1 includes an internal combustion engine 2 and an auxiliary machine 3 for cooling the internal combustion engine 2. The internal combustion engine 2 is, for example, a gasoline engine or a diesel engine, but is not limited thereto. The auxiliary machine 3 for cooling the internal combustion engine 2 is, for example, a radiator fan 32, a cooling water pump 33, and an oil pump 34, but is not limited thereto.

[0018] A cooling water circuit 4, which is a passage for circulating cooling water in the internal combustion engine 2, is provided in the internal combustion engine 2. A radiator 31 and a cooling water pump 33 are provided in the cooling water circuit 4. The radiator 31 is a device for radiating the heat of the cooling water heated by the internal combustion engine 2, and is installed, for example, in front of the internal combustion engine 2.

[0019] The cooling water pump 33 is a device for circulating the cooling water filled in the cooling water circuit 4. The cooling water pump 33 includes a mechanical pump driven by the power transmitted from the internal combustion engine 2 and an electric pump driven by the electric power supplied from the battery. In the mechanical pump, for example, the output value can be changed by providing an electromagnetic clutch between the internal combustion engine 2 and the mechanical pump. In the electric pump, for example, the output value can be changed by changing the pulse width (duty ratio).

[0020] The radiator fan 32 is a device for promoting the heat dissipation of the cooling water in the radiator 31, and is installed, for example, behind the radiator 31. The radiator fan 32 includes a mechanical fan driven by the power transmitted from the internal combustion engine 2 and an electric fan driven by the electric power supplied from the battery. In the mechanical fan, for example, the output value can be changed by providing an electromagnetic clutch (not shown) between the internal combustion engine 2 and the mechanical fan. In the electric fan, for example, the output value can be changed by changing the pulse width (duty ratio).

[0021] The oil pump 34 is a device for ensuring lubrication and cooling at various locations by supplying oil to various locations of the internal combustion engine 2. The oil pump 34 includes a mechanical pump driven by the power transmitted from the internal combustion engine 2 and an electric pump driven by the electric power supplied from the battery. In the mechanical pump, for example, the output value can be changed by providing an electromagnetic clutch between the internal combustion engine 2 and the mechanical pump. In the electric pump, for example, the output value can be changed by changing the pulse width (duty ratio).

[0022] [Control Configuration of Vehicle] FIG. 2 is a block diagram schematically showing the control configuration of the vehicle 1A shown in FIG. 1. As shown in FIG. 2, the vehicle 1A according to Embodiment 1 includes a detection device 5 for detecting the height of the water surface around the vehicle 1A and a control device 6A for changing the output value of the auxiliary machine 3.

[0023] The detection device 5 is, for example, a level sensor such as a float switch or a distance sensor such as a radar, but is not limited to these. The height of the water surface around the vehicle 1A represents the relative position of the water surface to the vehicle 1A which is submerged in water, that is, the relative position of the water surface to the internal combustion engine 2 mounted on the vehicle 1A.

[0024] The control device 6A is provided, for example, in an internal combustion engine control unit (hereinafter referred to as "engine ECU") that controls the internal combustion engine 2 and auxiliary equipment 3, but is not limited to this, and may be provided separately from the engine ECU. The control device 6A is composed, for example, of a processor consisting of an arithmetic unit, registers for storing instructions and information, and peripheral circuits, a memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and an input interface, but is not limited to this.

[0025] The control device 6A changes the output of the auxiliary equipment 3 to a second output value smaller than the first output value before the water level around the vehicle 1A exceeds the first threshold LV1, if the water level rises above a predetermined first threshold LV1. The first threshold LV1 is, for example, the position where the internal combustion engine 2 is submerged in water, i.e., the height of the lower end of the internal combustion engine 2, and is determined by relating the height of the vehicle 1A to the height of the internal combustion engine 2. The first output value before the water level rises above the first threshold LV1 is, for example, a variable value that fluctuates depending on the rotational speed of the internal combustion engine 2, or a variable value that fluctuates depending on the temperature of the coolant, but it may also be a fixed value that does not fluctuate. The second output value after the water level rises above the first threshold LV1 may be a variable value that fluctuates depending on the rotational speed of the internal combustion engine 2 or the temperature of the coolant, or it may be a fixed value that does not fluctuate, as long as it is smaller than the first output value. Furthermore, if the first and second output values ​​are variable values ​​that change depending on the rotational speed of the internal combustion engine 2, the second output value is smaller than the first output value when compared under the condition that the rotational speed of the internal combustion engine 2 is the same.

[0026] [Vehicle operation] The operation of vehicle 1A in Embodiment 1 will now be described in detail. The auxiliary equipment 3 of vehicle 1A in Embodiment 1 includes a radiator fan 32. Figure 3 is a flowchart showing the operation of vehicle 1A as shown in Figure 1. As shown in Figure 3, in vehicle 1A in Embodiment 1, the detection device 5 detects the water level (step S11). If the water level is lower than the first threshold LV1 (step S12: No), the output value of auxiliary equipment 3 is set to the first output value (step S13). On the other hand, if the water level is higher than the first threshold LV1 (step S12: Yes), the output value of auxiliary equipment 3 is changed to a second output value smaller than the first output value (step S14). When auxiliary equipment 3 is a radiator fan 32, the first output value and the second output value are the rotational speed of the radiator fan 32 per unit time (hereinafter simply referred to as "rotational speed"). In other words, if the water level is higher than the first threshold LV1 (step S12: Yes), the rotation speed of the radiator fan 32 is reduced compared to when the water level is lower than the first threshold LV1.

[0027] Next, Figure 4 will be explained. If the water level is higher than the first threshold LV1, that is, if step S12 in Figure 3 is Yes, and the water level rises higher than the previous level (step S21: Yes), the rotation speed of the radiator fan 32 is reduced from the previous rotation speed. If the water level does not change (step S21: No), the rotation speed of the radiator fan 32 is maintained. If the water level falls lower than the previous level, the rotation speed of the radiator fan 32 may be reduced from the previous level. The rotation speed of the radiator fan 32 may be gradually reduced in accordance with the water level, or it may be reduced in steps.

[0028] [effect] When the internal combustion engine 2 is submerged in water, its cooling is accelerated, allowing the internal combustion engine 2 to be cooled even if the output of the auxiliary equipment 3 is reduced. In Embodiment 1, when the internal combustion engine 2 is submerged in water, the output value of the auxiliary equipment 3 is changed from a first output value to a second output value smaller than the first output value. This allows energy to be saved to operate the auxiliary equipment 3. In particular, if the auxiliary equipment 3 is a radiator fan 32, when the radiator fan 32 is submerged in water, the driving resistance of the radiator fan 32 increases, so the driving energy required to maintain the same rotational speed of the radiator fan 32 increases compared to before the radiator fan 32 was submerged in water. Furthermore, the more the radiator fan 32 is submerged in water, the more driving energy is required to maintain the same rotational speed of the radiator fan 32. Therefore, in Embodiment 1, the rotational speed of the radiator fan 32 is reduced as the water level rises. This allows energy to be saved more effectively to operate the auxiliary equipment 3.

[0029] In Embodiment 1, the first threshold LV1 was set to the water level at which the internal combustion engine 2 is submerged. However, it is not limited to this, and may be set to, for example, the water level at which the radiator fan 32 is submerged, or the water level at which the radiator 31 is submerged. Furthermore, the first threshold LV1 may be set to a water level at which the internal combustion engine 2 is not submerged, but is sufficient to cool the internal combustion engine 2 sufficiently by the waves and spray generated in the surrounding water as the vehicle 1A moves. The water level at which the internal combustion engine 2 is sufficiently cooled by waves and spray can be predetermined based on experiments and analyses. In other words, the first threshold LV1 should be set to a water level at which the cooling of the internal combustion engine 2 and the cooling water flowing to the internal combustion engine 2 is promoted by the water surrounding the vehicle 1A.

[0030] [Embodiment 2] [Vehicle's Mechanical Configuration] The mechanical configuration of vehicle 1B according to Embodiment 2 is the same as that of vehicle 1A according to Embodiment 1, but the auxiliary equipment 3 of vehicle 1B according to Embodiment 2 includes a radiator fan 32, a coolant pump 33, and an oil pump 34.

[0031] [Vehicle control configuration] The control configuration of vehicle 1B according to Embodiment 2 is the same as the control configuration of vehicle 1A according to Embodiment 1, except for the control device 6B.

[0032] The control device 6B of the vehicle 1B according to Embodiment 2 stores a first threshold LV1, a second threshold LV2 predetermined to be higher than the first threshold LV1, and a third threshold LV3 predetermined to be higher than the second threshold LV2. When the water level rises above the first threshold LV1, the rotation speed of the radiator fan 32 is changed from the first rotation speed (first output value) to the second rotation speed (second output value). When the water level rises above the second threshold LV2, the rotation speed per unit time of the cooling water pump 33 (hereinafter simply referred to as "rotation speed") is changed to a fourth rotation speed that is less than the third rotation speed that rises above the second threshold LV2. When the water level rises above the third threshold LV3, the rotation speed per unit time of the oil pump 34 (hereinafter simply referred to as "rotation speed") is changed to a sixth rotation speed that is less than the fifth rotation speed that rises above the third threshold LV3. The first rotational speed, second rotational speed, third rotational speed, fourth rotational speed, fifth rotational speed, and sixth rotational speed may be variable values ​​that fluctuate depending on the rotational speed of the internal combustion engine 2 and the temperature of the coolant, or they may be fixed values ​​that do not fluctuate depending on the rotational speed of the internal combustion engine 2 and the temperature of the coolant. If the first rotational speed, second rotational speed, third rotational speed, fourth rotational speed, fifth rotational speed, and sixth rotational speed are variable values ​​that fluctuate depending on the rotational speed of the internal combustion engine 2, then, when compared under the same rotational speed of the internal combustion engine 2, the second rotational speed should be smaller than the first rotational speed, the fourth rotational speed should be smaller than the third rotational speed, and the sixth rotational speed should be smaller than the fifth rotational speed.

[0033] [Vehicle operation] Figure 5 is a flowchart showing the operation of vehicle 1B according to Embodiment 2. As shown in Figure 5, in vehicle 1B according to Embodiment 2, the detection device 5 detects the water level (step S31). When the water level rises above the first threshold LV1 (step S32: Yes), the rotation speed of the radiator fan 32 is changed to a second rotation speed, which is less than the first rotation speed required to reach above the first threshold LV1 (step S33). Then, when the water level rises above the second threshold LV2 (step S34: Yes), the rotation speed of the coolant pump 33 is changed to a fourth rotation speed, which is less than the third rotation speed required to reach above the second threshold LV2 (step S35). Then, when the water level rises further above the third threshold LV3 (step S42: Yes), the rotation speed of the oil pump 34 is changed to a sixth rotation speed, which is less than the fifth rotation speed required to reach above the third threshold LV3 (step S43). In other words, as the water level rises, the rotation speed of the radiator fan 32, the coolant pump 33, and the oil pump 34 are reduced in that order.

[0034] [effect] As the water level rises, the cooling of the internal combustion engine 2 is promoted. Therefore, among the multiple auxiliary devices 3 that cool the internal combustion engine 2, the number of auxiliary devices 3 whose output (rotational speed) is reduced as the water level rises is increased. At this time, the rotational speed of the radiator fan 32, which is an auxiliary device 3 whose driving energy changes according to the water level, is preferentially reduced, while the rotational speed of the oil pump 34, which affects the lubrication of the internal combustion engine 2 and thus fuel efficiency, is kept as high as possible. This saves energy in the auxiliary devices 3 and suppresses deterioration of the fuel efficiency of the internal combustion engine 2. In Embodiment 2, the first threshold LV1, the second threshold LV2, and the third threshold LV3 are set to the values ​​shown in Figure 6. As shown in Figure 6, the first threshold LV1 is set at the lower end of the height direction of the internal combustion engine 2, the second threshold LV2 is set at the middle of the height direction of the internal combustion engine 2, and the third threshold LV3 is set at the upper end of the height direction of the internal combustion engine 2. When the water level reaches the first threshold LV1 and the internal combustion engine 2 is submerged in water up to its lower end in the height direction, the internal combustion engine 2 is cooled not only by the coolant but also by the surrounding water. At this point, the rotation speed of the radiator fan 32 is changed from the first rotation speed to a second rotation speed which is less than the first rotation speed, saving energy to operate the radiator fan 32. By reducing the rotation speed of the radiator fan 32, which is an auxiliary device 3 whose driving energy changes according to the water level, energy saving begins before the water level rises further and the energy required to operate the radiator fan 32 increases. When the water level reaches the second threshold LV2 and the internal combustion engine 2 is submerged in water up to its middle in the height direction, the rotation speed of the coolant pump 33 is further changed from the third rotation speed to a fourth rotation speed which is less than the third rotation speed, saving energy to operate the coolant pump 33. When the internal combustion engine 2 is submerged in water up to its middle in the height direction, the radiator 31 is also considered to be submerged in water. Therefore, since the cooling capacity of the coolant provided by the radiator 31 is considered to be improved, sufficient cooling capacity for the internal combustion engine 2 can be ensured even if the rotational speed of the coolant pump 33 is reduced. When the water level reaches the third threshold LV3 and the water immerses the internal combustion engine 2 up to its upper end in the height direction, the rotational speed of the oil pump 34 is further changed from the fifth rotational speed to a sixth rotational speed which is less than the fifth rotational speed, thereby saving energy required to operate the oil pump 34.Reducing the rotational speed of the oil pump 34 would decrease the amount of lubricating oil supplied to the internal combustion engine 2, potentially increasing friction and worsening fuel efficiency. However, if the internal combustion engine 2 is submerged in water up to its upper end, the surrounding water would sufficiently cool the engine 2, and the viscosity of the lubricating oil would also be sufficiently maintained. Therefore, since reducing the rotational speed of the oil pump 34 would not significantly increase friction, priority would be given to saving energy to operate the oil pump 34. Note that the first threshold LV1, second threshold LV2, and third threshold LV3 are not limited to those described above.

[0035] The present invention is not limited to the embodiments described above, and includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate. [Explanation of Symbols]

[0036] Vehicles 1A and 1B 2 Internal Combustion Engine 3. Auxiliary equipment 31 Radiator 32 Radiator Fan 33 Cooling water pump 34 Oil pump 4 Cooling water circuit 5. Detection device 6A, 6B Control Unit LV1 First threshold LV2 Second threshold LV3 Third threshold

Claims

1. Internal combustion engines and Multiple auxiliary devices for cooling the internal combustion engine, A vehicle equipped with, A detection device for detecting the height of the water level around the vehicle, A control device that, when the water level rises above a predetermined first threshold, changes the output value of the auxiliary equipment to an output value smaller than the output value before the water level rises above the first threshold, Equipped with, The control device is a vehicle that increases the number of auxiliary devices that reduce the output value as the water level rises when the water level rises above the first threshold.

2. The aforementioned auxiliary equipment includes a radiator fan. The control device, when the water level rises above the first threshold, reduces the rotation speed of the radiator fan as the water level rises. The vehicle according to claim 1.

3. The aforementioned auxiliary equipment includes a radiator fan and a coolant pump. The control device, when the water level rises above the first threshold, changes the rotation speed of the radiator fan to a second rotation speed that is less than the first rotation speed at which the water level rises above the first threshold, and when the water level rises above a second threshold predetermined to be higher than the first threshold, changes the rotation speed of the cooling water pump to a fourth rotation speed that is less than the third rotation speed at which the water level rises above the second threshold. The vehicle according to claim 1.

4. The aforementioned auxiliary equipment includes an oil pump, The control device, when the water level rises above a third threshold predetermined to be higher than the second threshold, changes the rotational speed of the oil pump to a sixth rotational speed that is less than the fifth rotational speed at which the water level rises above the third threshold. The vehicle according to claim 3.

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