JP7328791B2 - Air conditioning controller for electric trucks - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning control system for electric trucks, and more particularly to technology for improving the cooling performance of radiators and condensers.

In recent years, in the field of commercial vehicles such as trucks, electric trucks driven only by an electric motor without an internal combustion engine have been developed from the viewpoint of reducing the environmental load (Patent Document 1).

In such an electric vehicle, two capacitors may be provided in the air conditioning circuit for air conditioning the cab interior in order to support various cooling modes such as battery cooling using the air conditioning circuit.

JP 2016-113063 A

However, in electric vehicles that do not have an internal combustion engine, as a result of the elimination of engine noise and improved quietness in the powertrain, noise from the fan that is driven to cool the condenser is a factor in the noise problem inside and outside the vehicle. prominently.

In addition, when two condensers are provided for the purpose of coping with various cooling modes, noise inside and outside the vehicle due to fan driving of the air conditioning condensers may increase.

From the above, the problem to be solved by the present application is that in an electric truck equipped with two condensers, the noise inside and outside the vehicle caused by the driving of the fans (first fan, second fan) of the air conditioning condensers (first condenser, second condenser). It is an object of the present invention to provide an air conditioning control system for an electric truck that can reduce the influence.

To achieve the above object, an air conditioning control system for an electric truck according to the present invention is an air conditioning control system for an electric truck that controls the air conditioning in the cab of an electric truck that is driven by a driving motor that is supplied with electric power from a battery. an air conditioning circuit provided in the electric truck; a first condenser and a second condenser provided in the air conditioning circuit for exchanging heat between a working fluid of the air conditioning circuit and outside air; and an outside air can be supplied to the first condenser. A first fan provided in a first region between and above the frames of the electric truck and in which the cab chamber is arranged, and is configured to be able to supply outside air to the second condenser, and the first region A second fan provided in a second region outside the vehicle, and a rotation speed control unit that controls the rotation speeds of the first fan and the second fan in a plurality of drive modes, The plurality of drive modes include a first drive mode for controlling the first fan and the second fan so that the rotation speed of the first fan is higher than the rotation speed of the second fan; and a second drive mode for controlling the first fan and the second fan so that the rotation speed of the second fan is higher than the rotation speed of the first fan.

Thus, by controlling the first fan and the second fan so that the rotation speed of the first fan is higher than the rotation speed of the second fan in the first drive mode, cooling the second capacitor is performed. To reduce the noise effect on the outside of the vehicle due to the driving sound of the driven second fan, and to increase the rotation speed of the second fan to be higher than the rotation speed of the first fan by the second drive mode. By controlling the first fan and the second fan, it is possible to reduce the influence of noise on the cab, that is, the inside of the vehicle, due to the drive sound of the first fan that is driven to cool the first condenser.

1 is a top view schematically showing the overall configuration of an electric vehicle according to an embodiment; FIG. 1 is a circuit diagram showing a vehicle temperature control device according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the overall configuration of a vehicle 1 according to this embodiment will be described with reference to FIG. Here, FIG. 1 is a top view schematically showing the overall configuration of the electric vehicle according to this embodiment.
As shown in FIG. 1, the vehicle 1 according to this embodiment includes a ladder frame 10, a cab 20, a packing box 30, a wheel mechanism 40, a driving device 50, a battery pack 60, an inverter 80, and a vehicle temperature control device 100. It is an electric truck. Note that FIG. 1 shows a top view of the cab 20 and the luggage box 30 as viewed from above the vehicle 1 so as to be seen through.

The ladder frame 10 has a left side rail (frame) 11 L, a right side rail (frame) 11 R, and a plurality of cross members 12 . The left side rail 11L and the right side rail 11R extend in the vehicle length direction A of the vehicle 1 and are arranged parallel to each other with respect to the vehicle width direction B. As shown in FIG. A plurality of cross members 12 connect the left side rail 11L and the right side rail 11R. That is, the ladder frame 10 constitutes a so-called ladder frame. The ladder frame 10 supports the cab 20 , the luggage box 30 , the driving device 50 , the battery pack 60 and other heavy objects mounted on the vehicle 1 . Hereinafter, the left side rail 11L and the right side rail 11R are collectively referred to as the side rail 11 as well.

The cab 20 is a structure including a driver's seat (not shown) on which the driver sits, and is provided above the front portion of the ladder frame 10 . On the other hand, the luggage box 30 is a structure in which luggage and the like transported by the vehicle 1 are loaded, and is provided above the rear portion of the ladder frame 10 .

The wheel mechanism 40 positioned in front of the vehicle is composed of left and right front wheels 41 positioned in front of the vehicle and a front axle 42 as an axle for the two front wheels 41 in this embodiment. The wheel mechanism 40 positioned behind the vehicle is composed of two rear wheels 43 positioned on the rear side of the vehicle and two on each side, and a rear axle 44 as an axle for the rear wheels 43 . In the vehicle 1 according to this embodiment, the driving force is transmitted so that the rear wheels 43 function as drive wheels, and the vehicle 1 travels. The wheel mechanism 40 is suspended from the ladder frame 10 via a suspension mechanism (not shown) to support the weight of the vehicle 1 .

The driving device 50 has a motor unit 51 and a gear unit 52 . The motor unit 51 is composed of a traveling motor 53 and a motor housing 54 that accommodates the traveling motor 53 . The gear unit 52 includes a speed reduction mechanism 55 consisting of a plurality of gears, a differential mechanism 56 that distributes the power input from the speed reduction mechanism 55 to the left and right rear wheels 43, and gears that accommodate the speed reduction mechanism 55 and the differential mechanism 56. It consists of a housing 57 .

In addition, the driving device 50 reduces the driving torque of the driving motor 53 to a rotational speed suitable for driving the vehicle via the speed reduction mechanism 55 and the differential mechanism 56 and transmits the driving force to the rear axle 44 . As a result, the driving device 50 can rotate the rear wheels 43 via the rear axle 44 to drive the vehicle 1 . Here, in this embodiment, the driving device 50 is arranged inside the left side rail 11L and the right side rail 11R in the vehicle width direction B (that is, the space between the side rails), and is supported by a support member (not shown). It is supported by the ladder frame 10.

The battery pack 60 has a battery 61 that supplies electric power to the driving motor 53 as an energy source for driving the vehicle 1 and a battery housing 62 that houses the battery 61 . Battery pack 60 is a relatively large-sized, high-capacity secondary battery for storing electric power required for vehicle 1 . Here, in this embodiment, the battery pack 60 is arranged between the left side rail 11L and the right side rail 11R in the vehicle width direction B and in front of the drive device 50 in the vehicle. For example, the battery pack 60 is fixed or suspended on the ladder frame 10 by connecting members (not shown).

In this embodiment, the drive device 50 and the battery pack 60 constitute an electric drive unit group 70 . Here, the electric drive unit group 70 includes the battery 61, the traveling motor 53, the speed reduction mechanism 55, and the differential mechanism 56, and has main components necessary for electric driving of the vehicle 1.

Inverter 80 functions as a drive power supply unit that converts DC power supplied from battery pack 60 into AC power and supplies the AC power to traveling motor 53 . Then, according to the accelerator operation on the vehicle 1, the supply amount of AC power is controlled, and the rotational speed of the driving motor 53 is controlled. Although inverter 80 is provided behind gear unit 52 in FIG. 1 , inverter 80 may be provided between battery pack 60 and drive device 50 .

FIG. 2 is a circuit diagram showing the vehicle temperature control device 100 according to one embodiment of the present invention. The vehicle temperature management device 100 is a device for managing the temperature of a plurality of target devices mounted in a vehicle such as an electric vehicle, and includes a first refrigerant circulation circuit 130 and a second refrigerant circulation circuit (air conditioning circuit) 170. including. The vehicle temperature management device 100 adjusts the temperature of the plurality of target devices by circulating the refrigerant along each of the first refrigerant circulation circuit 130 and the second refrigerant circulation circuit 170 . The first refrigerant circulation circuit 130 and the second refrigerant circulation circuit 170 will be described in detail below.

(First refrigerant circulation circuit)
First, the first refrigerant circulation circuit 130 is described. The first refrigerant circulation circuit 130 is a refrigerant circulation circuit for circulating a first refrigerant that exchanges heat with a first temperature adjustment target device group including, for example, an inverter 80 that supplies power to the drive motor 53 . Here, the first temperature adjustment target device group is, for example, target devices that operate efficiently in an intermediate operating temperature zone among the three operating temperature zones. The first temperature-adjustable device group in the present embodiment includes, for example, in addition to the inverter 80, a heater core 300 provided in the HVAC (air conditioning) 20a. Also, the first refrigerant is antifreeze.

Here, the HVAC 20a is provided with a heater core 300 and an evaporator 700, which will be described later, inside the cab 20. The heater core 300 heats the air (internal air) in the cab 20, and the evaporator 700 cools the internal air, thereby adjusting the temperature of the internal air. It is an air conditioner that

As shown in FIG. 2, the first refrigerant circulation circuit 130 in this embodiment includes a pump 131, an inverter heat exchange flow path 132, a valve 133, a pump flow path 134, a radiator heat exchange flow path 135, a water and heater 139 .
The pump 131 is a device that circulates the first coolant filled in the flow path in the direction of the arrow. In the pump 131 of this embodiment, the discharge amount (delivery amount) of the first refrigerant is controlled by a control device (not shown).

The inverter heat exchange flow path 132 is a refrigerant flow path that connects the pump 131 and the valve 133 and allows the first refrigerant sent from the pump 131 to flow to the valve 133 . The inverter heat exchange flow path 132 is arranged so as to pass through the inverter 80 , the water heater 139 and the heater core 300 . The inverter heat exchange channel 132 is made of metal such as steel pipe.

The first refrigerant sent from pump 131 passes through inverter 80 along inverter heat exchange flow path 132 . The first refrigerant passing through inverter 80 exchanges heat with inverter 80 . The first refrigerant cools inverter 80 by exchanging heat with inverter 80 . That is, the first refrigerant is heated by the heat of inverter 80 .

The first refrigerant that has exchanged heat with inverter 80 passes through water heater 139 . The water heater 139 can heat the passing first coolant by being actuated. After passing through the water heater 139 , the first coolant passes through the heater core 300 . As a result, for example, when the temperature of the inside air is lower than the desired temperature, the first refrigerant can be heated to heat the heater core 300, thereby warming the air blown from the HVAC 20a. The first refrigerant that has exchanged heat with heater core 300 flows to valve 133 .

The valve 133 has a first port 133a connected to the inverter heat exchange channel 132, a second port 133b connected to the radiator heat exchange channel 135, and a third port 133c connected to the pump channel 134. It is a three-way solenoid valve. The valve 133 is made of metal such as iron or resin such as rubber. The valve 133 in this embodiment opens and closes each port by a control device (not shown).

The pump channel 134 is a coolant channel that connects the third port 133 c of the valve 133 and the pump 131 and allows the first coolant discharged from the third port 133 c of the valve 133 to flow to the pump 131 . The pump channel 134 is made of metal such as steel pipe. The first refrigerant that has passed through the pump flow path 134 flows to the pump 131 and circulates through the first refrigerant circulation circuit 130 again. In addition, the pump channel 134 shares a partial section before the pump 131 with the radiator heat exchange channel 135 .

The radiator heat exchange channel 135 connects the second port 133b of the valve 133 and the pump 131, and is a coolant channel for flowing the first coolant discharged from the second port 133b of the valve 133 to the pump 131. . The radiator heat exchange channel 135 is made of metal such as steel pipe. For example, the radiator heat exchange channel 135 is provided with a radiator 136 that releases the heat of the first refrigerant to the outside air. Heat of the first coolant passing through the radiator 136 is released by the radiator 136 . The first refrigerant whose heat has been released by the radiator 136 flows to the pump 131 and circulates through the first refrigerant circulation circuit 130 again.

(Second refrigerant circulation circuit)
Next, the second refrigerant circulation circuit 170 according to the present invention will be explained. The second refrigerant circulation circuit 170 is a so-called refrigeration cycle circuit that reduces the temperature inside the cab 20 by circulating a second refrigerant (working fluid) that is Freon gas. This second refrigerant circulation circuit 170 includes a compressor 201 , a first condenser 203 , a second condenser 205 , an expansion valve 208 and an evaporator 700 .

Compressor 201 is a compressor operated by electric power supplied from battery 61 . The compressor 201 can circulate through the second refrigerant circulation circuit 170 while compressing the second refrigerant by operating.

The first condenser 203 is a heat exchanger capable of exchanging heat between the second refrigerant and the outside air. The second condenser 205, like the first condenser 203, is a heat exchanger capable of exchanging heat between the second refrigerant and the outside air, and is located upstream of the first condenser 203 in the second refrigerant circulation circuit 170. .

The expansion valve 208 can expand the second refrigerant cooled by the first condenser 203 and the second condenser 205 to further cool it. Evaporator 700 is a heat exchanger capable of exchanging heat between the inside air and the second refrigerant.

Therefore, the second refrigerant circulation circuit 170 cools the second refrigerant compressed and heated by operating the compressor 201 by exchanging heat with the outside air by the second condenser 205 and the first condenser 203, and by the expansion valve 208 Further cooling can be achieved by expanding the second refrigerant.

After the second refrigerant is heated by the evaporator 700, the second refrigerant circulation circuit 170 can cool the inside air and the second refrigerant by returning to the compressor 201 and repeating the above circulation.

Here, according to FIG. 1, a first fan 211 that introduces outside air to the first condenser 203 and the radiator 136 is arranged behind the first condenser 203 and the radiator 136 in the vehicle length direction A. As shown in FIG. The first capacitor 203, the radiator 136 and the first fan 211 are located below the cab 20 and in the first region between the left side rail 11L and the right side rail 11R in the vehicle width direction B. A soundproof cover 202 covers the sides in the vehicle width direction B and the upper and lower sides in the vehicle height direction.

A second fan 213 that introduces outside air to the second condenser 205 is arranged below the cab 20 and behind the second condenser 205 in the vehicle length direction A. As shown in FIG. The second capacitor 205 and the second fan 213 are located in a second area below the cab 20 and to the left of the left side rail 11L with respect to the vehicle width direction B. As shown in FIG.

Furthermore, the first fan 211 and the second fan 213 are provided with a first motor 211a and a second motor 213a, respectively. The rotation speed of the first motor 211a can be steplessly changed under the control of the ECU 800, which will be described later. Further, the second motor 213a can change the rotation speed in a plurality of stages (for example, two stages) under the control of the ECU 800, which will be described later.

An ECU (rotational speed control unit) 800 is a control device for performing overall control including operation control of the traveling motor 53, and includes input/output devices, storage devices (ROM, RAM, nonvolatile RAM, etc.), It is configured including a central processing unit (CPU) and the like.

The ECU 800 is electrically connected to the first motor 211a of the first fan 211 and the second motor 213a of the second fan 213 . Thereby, the ECU 800 can drive the first fan 211 and the second fan 213 while controlling the rotational speed.

Specifically, the ECU 800 drives the first motor 211a of the first fan 211 at the maximum rotation speed, and drives the second motor 213a of the second fan 213 at a rotation speed of, for example, 60% of the maximum rotation speed. A drive mode, a second drive mode in which the first motor 211a of the first fan 211 is driven at, for example, 30% of the maximum rotation speed, and the second motor 213a of the second fan 213 is driven at the maximum rotation speed. It includes a plurality of drive modes, and can automatically switch between drive modes according to, for example, the running state of the vehicle.

Here, as described above, the first fan 211 is located in the first region, that is, below the cab 20 and between the left side rail 11L and the right side rail 11R in the vehicle width direction B. As shown in FIG. The second fan 213 is located in the second region, that is, below the cab 20 and to the left of the left side rail 11L with respect to the vehicle width direction B. As shown in FIG.

As a result, when the first fan 211 is driven at a high rotational speed such as the maximum rotational speed, the driving sound and vibration of the first fan 211 are transmitted into the cab 20, and the second fan 213 is driven at a high rotational speed such as the maximum rotational speed. When driven, the driving sound of the second fan 213 is transmitted to the outside of the vehicle 1 .

Therefore, in an environment where the outside of the vehicle 1 is relatively quiet, such as in a residential area, the first motor 211a of the first fan 211 and the second motor 211a of the second fan 213 are driven in the first drive mode among the plurality of drive modes. By driving the second fan 213a, it is possible to reduce noise to the outside of the vehicle 1 caused by driving the second fan 213 at a high rotational speed.

In addition, for example, when the vehicle 1 is traveling at a speed of about 60 km/h and so-called road noise is generated, or when other vehicles are traveling relatively frequently, such as on a main road, the second fan 213 is turned off. In an environment in which the drive noise is not conspicuous, the first fan 211 and the second fan 213 are driven in the second drive mode among the plurality of drive modes so that the first fan 211 and the second fan 213 are driven in the second drive mode. It is possible to reduce driving noise and vibration of the first fan 211 transmitted to the inside of the cab 20 due to driving at a high rotational speed.

As a result, although the total heat exchange performance of the first condenser 203 and the second condenser 205 is lowered, the inside and outside of the cab 20 due to the driving sound of the first fan 211 and the second fan 213 is prevented without lowering the required vehicle heat exchange performance. The influence of noise on the outside of the vehicle 1 can be reduced.

As described above, in the air-conditioning control apparatus for an electric truck according to the present invention, the air in the cab 20 of the vehicle 1 driven by the traveling motor 53 to which power is supplied from the battery 61 and the second refrigerant circulation circuit 170 In the air conditioning control device for an electric truck that controls the air conditioning in the cab 20 by exchanging heat with the second refrigerant, the second refrigerant is provided in the second refrigerant circulation circuit 170 and exchanges heat between the second refrigerant and the outside air. When the area between the frames of the vehicle 1 and the area between the frames of the vehicle 1 in which the cab 20 is provided above is defined as the first area, the first area is the first area. a first fan 211 provided in the first fan 211, a second fan 213 configured to be able to supply outside air to the second condenser 205, and provided in a second region which is a region outside the first region of the vehicle, the first fan 211 and and an ECU 800 that controls the number of rotations of the second fan 213 in a plurality of drive modes, in which the number of rotations of the first fan 211 is higher than the number of rotations of the second fan 213. and a first drive mode for controlling the first fan 211 and the second fan 213 so that the rotation speed of the second fan 213 is higher than the rotation speed of the first fan 211. a second drive mode that controls 213;

Therefore, by controlling the first fan 211 and the second fan 213 so that the rotation speed of the first fan 211 is higher than the rotation speed of the second fan 213 in the first driving mode, the cooling of the second capacitor 205 is reduced. Therefore, it is possible to reduce the influence of noise to the outside of the vehicle 1 due to the driving sound of the second fan 213 driven for the purpose.

In addition, by controlling the first fan 211 and the second fan 213 so that the rotation speed of the second fan 213 is higher than the rotation speed of the first fan 211 in the second drive mode, the cooling of the first capacitor 203 is improved. Therefore, it is possible to reduce the influence of noise on the cab 20, that is, the inside of the vehicle, due to the driving sound of the first fan 211 driven for the purpose.

Furthermore, in the first drive mode, the number of revolutions of the first fan 211 is increased, so that the number of revolutions of the second fan 213 is smaller than the number of revolutions of the first fan 211, thereby cooling the second capacitor 205. It can compensate for the decrease in performance.

In the second drive mode, by increasing the rotation speed of the second fan 213, the rotation speed of the first fan 211 is smaller than the rotation speed of the second fan 213, resulting in cooling performance of the first capacitor 203. can compensate for the decline in

Although the description of the air-conditioning control device for electric trucks according to the present invention has been completed above, the present invention is not limited to the above-described embodiments, and can be modified without departing from the gist of the invention.
For example, in the present embodiment, the number of rotations of the first fan 211 and the second fan 213 is controlled by the first drive mode and the second drive mode included in the ECU 800. The power consumption of the motor 211a and the second motor 213a, the rotation output related to the drive sound of the first fan 211 and the second fan 213, which is based on the amount of outside air supplied to each fan, the wind speed, etc., is used as an index. good too.

1 vehicle (electric truck)
11L left side rail (frame)
11R right side rail (frame)
20 cab 20a HVAC (air conditioning)
53 Traveling motor 61 Battery 170 Second refrigerant circulation circuit (air conditioning circuit)
203 First capacitor 205 Second capacitor 211 First fan 213 Second fan 800 ECU (rotation speed control unit)

Claims (2)

An air-conditioning control device for an electric-powered truck that controls air-conditioning in a cab of an electric-powered truck driven by a driving motor that is supplied with power from a battery,
an air conditioning circuit provided in the electric truck;
a first condenser and a second condenser provided in the air conditioning circuit for exchanging heat between the working fluid of the air conditioning circuit and outside air;
a first fan configured to be able to supply outside air to the first condenser and provided in a first region where the cab chamber is disposed above and between frames of the electric truck;
a second fan configured to be able to supply outside air to the second condenser and provided in a second region outside the vehicle relative to the first region;
a rotation speed control unit that controls the rotation speeds of the first fan and the second fan in a plurality of drive modes,
The plurality of drive modes include a first drive mode for controlling the first fan and the second fan so that the rotation speed of the first fan is higher than the rotation speed of the second fan; and a second drive mode for controlling the first fan and the second fan so that the rotation speed of the second fan is higher than the rotation speed of the first fan. Truck climate control. 2. The air conditioning control device for an electric truck according to claim 1, wherein the first fan and the second fan are controlled in the second drive mode when the electric truck is at or above a predetermined vehicle speed.

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