JPH07266851A - Air conditioner for electric vehicle - Google Patents

Abstract

PURPOSE:To provide an air conditioner for an electric vehicle which has a simple construction for preventing a windshield from clouding with low production cost while electric power can be utilized not only for removing the clouding from the windshield but also for effective air conditioning. CONSTITUTION:A controller 50 drives a PTC heater 20 in a heat pump cycle 1 properly according to the atmospheric temperature, indoor air temperature or the like on the basis of a commanding signal of a DEF mode commanding switch 33 to blow out air from an air conditioning unit 10 to the inside surface of a windshield for removing cloudiness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an electric vehicle capable of effectively removing fogging on a windshield.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner for an electric vehicle capable of removing fog on a windshield, for example, Japanese Patent Laid-Open No. 4-31 is known.
There is a heating device for an electric vehicle described in Japanese Patent No. 7840.
That is, an in-vehicle battery, an inside air circulation type vehicle interior heating means, an electrically heated windshield glass formed by vapor-depositing a transparent thin film resistor on the windshield that separates the vehicle interior from the outside, and a windshield temperature higher than the vehicle interior temperature. Is a heating device for an electric vehicle, comprising: the vehicle interior heating means; and an energizing means for energizing the electrically heated windshield.

[0003]

However, in the above-mentioned electric vehicle heating device, the transparent thin film resistor must be vapor-deposited on the windshield only in order to prevent the windshield from being fogged, which is troublesome to manufacture. It costs a lot and the production cost is high. Further, since the electric heating windshield is energized only to prevent the windshield from fogging, there is a problem that the power consumption cannot be effectively used for air conditioning.

In view of the above problems, the present invention has a simple structure for preventing fogging of the windshield, has a low production cost, and not only uses electric power to remove the fogging of the windshield. An object of the present invention is to provide an air conditioner for an electric vehicle that can be effectively used for air conditioning.

[0005]

In order to achieve the above-mentioned object, the present inventors set the inside surface temperature of the windshield to be a dew point or higher, or the inside of the windshield to remove the fogging of the windshield. The present invention has been completed, paying attention to the fact that the dew point can be lowered by lowering the humidity of air near the surface.

That is, an air conditioner for an electric vehicle according to the present invention has an air conditioner unit and an air conditioner unit.
A heat pump cycle for circulating heating and cooling to form a heat medium is formed, and a heat exchanger inside the vehicle arranged in the air conditioning unit, an auxiliary heater arranged downstream of the heat exchanger inside the vehicle, and a windshield. DEF blows air to the inner surface
Based on the DEF mode command means for commanding the air conditioning unit to perform the mode operation, and at least one of the heat pump cycle and the auxiliary heater is driven based on the command signal of the DEF mode command means, and air is blown on the inner surface of the windshield. And a control device for controlling the air conditioning unit so as to remove the fog. Further, the control device may drive at least one of the heat pump cycle and the auxiliary heater to operate the air conditioning unit in the DEF mode based on the outside air temperature. Further, the control device may drive at least one of the heat pump cycle and the auxiliary heater to operate the air conditioning unit in the DEF mode based on the operation mode of the heat pump cycle.

[0007]

Therefore, according to the present invention, at least one of the heat pump cycle and the auxiliary heater is driven to remove the fog on the windshield.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings of FIGS. The heat pump cycle 1 is used for the air conditioner for an electric vehicle of this embodiment. As shown in FIG. 1, the heat pump cycle 1 includes a vehicle exterior heat exchanger 2 arranged in the front part of a vehicle body, a vehicle interior heat exchanger 3 arranged in an air conditioning unit 10 in the vehicle interior front part, and a compressor 4. , A four-way valve 5, a capillary tube 6, and an accumulator 7.

When the interior of the vehicle is heated by the heat pump cycle 1, the heat exchange medium is circulated in the heating cycle. That is, the control device 30 described later switches the four-way valve 5 as shown by the solid line in FIG. 1 and drives the compressor 4 via the inverter 31 to make the heat exchange medium high temperature and high pressure, and the solid line in FIG. According to the arrow shown, after the heat is dissipated by the heat exchanger 3 inside the vehicle through the four-way valve 5, the pressure is reduced by the capillary tube 6, the heat is absorbed from the outside air in the heat exchanger 2 outside the vehicle, and the four-way valve 5 causes the accumulator 7 to move again. It is then returned to the compressor 4 and circulated. As a result, the air sucked into the air conditioning unit 10 is heated by the vehicle interior heat exchanger 3 and becomes warm air and is sent out into the vehicle.

When the inside of the vehicle is cooled by the heat pump cycle 1, the heat exchange medium is circulated in the cooling cycle. That is, the control device 30 switches the four-way valve 5 as shown by the dotted line in FIG. 1, drives the compressor 4 to set the heat exchange medium to high temperature and high pressure as described above, and follows the arrow shown by the dotted line in FIG. After the heat is dissipated by the vehicle exterior heat exchanger 2 via the four-way valve 5, the pressure is reduced by the capillary tube 6, and the air passing through the air conditioning unit 10 in the vehicle interior heat exchanger 3 is made to absorb heat, and the four-way valve 5 is operated by the accumulator 7 To the compressor 4 for circulation. As a result, the air sucked into the air conditioning unit 10 is cooled by the heat exchanger 3 inside the vehicle, becomes cold air, and is sent out into the vehicle.

On the other hand, an air conditioning unit 10 incorporating the heat exchanger 3 inside the heat pump cycle 1 is provided with an inside / outside air switching intake damper 11 on the upstream side in the air conditioning unit 10 to air condition the outside air 12a or the inside air 12b. The unit 10 is selected and sucked. The suction of air into the air conditioning unit 10 is performed by rotating the blower 13 provided on the downstream side of the intake damper 11 by the motor 14 connected to the control device 30.

On the downstream side of the blower 13, an in-vehicle heat exchanger 3 constituting the heat pump cycle 1 is arranged. The temperature in the vicinity of the heat exchanger 3 inside the vehicle is detected by a temperature sensor 15a provided in the vicinity of the downstream side thereof, and the detection signal is input to the control device 30.

An air mix damper 17 is formed on the downstream side of the vehicle interior heat exchanger 3 to form two flow passages 16a and 16b, and one of the flow passages 16b is provided with a PTC heater 20 as an auxiliary heater. It is provided. This PTC
The heater 20 is a constant temperature heating element whose resistance rapidly increases from a certain temperature and keeps the temperature constant due to the current limiting action in the region where the resistance changes abruptly.

Further, an adjustment damper 18 for adjusting the blowing amount of the air reheated by the PTC heater 20 is provided at the outlet of the flow passage 16b. When the air mix damper 17 rotates based on a control signal from the control device 30, the adjustment damper 18 rotates in response to the control signal based on the control signal.

A temperature sensor 15b is provided on the downstream side of the flow paths 16a and 16b, and further on the downstream side thereof, a DEF damper 1 rotated by an actuator (not shown).
9a, a VENT damper 19b, and a HEAT damper 19c are provided, and air is blown out into the vehicle from their respective outlets. In particular, the DEF
Air is blown out from the air outlets to which the dampers 19a are attached to the inner surfaces of the front and rear windows (not shown).

The PTC heater 20 is the relay 2
1 is connected to the control device 30 through the control device 3
On and off are controlled by 0.

The control device 30 calculates based on various conditions input from an outside air sensor 32 arranged in the vicinity of the exterior heat exchanger 2, an inside air sensor (not shown), and temperature sensors 15a and 15b. The blast temperature and the blast amount are controlled so that the occupant feels comfortable, and the dampers 19a, 19b, 19c are rotated according to the desired blowing mode selected by the DEF mode switch 33 or another mode switch. The desired air outlet is opened and closed.

Next, in order to remove the fogging of the windshield,
A control method when the DEF mode command switch 33 is turned on will be described based on the flowchart shown in FIG. First, in step S1, the occupant discovers that the windshield is cloudy and turns on the DEF command switch 33.
If the air conditioning unit 10 is set to the DEF operation mode in step 2, it is determined in step S3 whether the heat pump cycle 1 is a heating cycle. When it is determined that the heat pump cycle 1 is the heating cycle, that is, HEAT
When warm air is blown into the vehicle from the blow-out opening that the damper 19a rotates, the PTC heater that is the auxiliary heater is turned on in step S4, and the warm air whose temperature is further raised is blown to the inner surface of the windshield, By raising the temperature of the inner surface above the dew point, the fogging of the windshield is removed. Next, in step S5, it is determined whether or not the DEF command switch is off, and if it is determined to be off, it means that the occupant determines that the fog on the windshield has been removed and that the DEF command switch is off. If it is determined that it is not off, the process returns to step S3.

On the other hand, when it is determined in step S3 that the heat pump cycle 1 is not the heating cycle, the heat pump cycle 1 is set to the cooling cycle in step S6,
Dehumidify and cool to reduce the humidity of the air. Furthermore, step S
7, the PTC heater is turned on, and the air whose temperature has been lowered by the dehumidifying and cooling by the heat pump cycle is heated to a predetermined temperature, and then the heated dry air is blown onto the windshield, and the humidity of the air in the vicinity of the inner surface thereof is increased. To lower the dew point to remove fog on the windshield.
Then, in step S5, it is determined whether or not the DEF command switch is off, and if it is determined to be off, the occupant determines that the fogging of the windshield has been removed and the DEF command switch is turned off. If it is determined that it is not off, the process returns to step S3.

According to this embodiment, since the PTC heater is turned on in the heating / cooling cycle, there is an advantage that it is possible to remove the fog on the windshield without lowering the temperature in the vehicle compartment more than necessary.

In the above embodiment, when the heat pump cycle is the heating cycle, the method of driving the heat pump cycle and the PTC heater to remove the fog has been described. Depending on external conditions such as temperature and humidity inside the vehicle, only the heat pump cycle may be driven to remove the fog.
Further, in the above-described embodiment, when the heat pump cycle is the cooling cycle, the heat pump cycle and the P
Although the method of driving the TC heater to remove the fog has been described, the invention is not limited to this, and the outside air temperature, the inside air temperature,
Depending on the external conditions such as the humidity inside the vehicle, only the heat pump cycle may be driven to remove the fog. Further, in the above-described embodiment, the case where the heating cycle is first determined and processed is described, but the present invention is not limited to this.
Needless to say, it may be possible to first determine whether or not the cooling cycle is in progress and then perform the processing.

[0022]

As is apparent from the above description, according to the air conditioner for an electric vehicle of the present invention, it is possible to remove the fog on the windshield at the same time as the air conditioning in the passenger compartment, so that the electric power can be effectively utilized. Further, since the fogging of the windshield can be removed by the heat pump cycle and the auxiliary heater, it is not necessary to deposit the transparent thin film resistor on the windshield as in the conventional example. For this reason, the structure of the entire apparatus is simplified, the manufacturing is labor-free, and the production cost is reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an air conditioner for an electric vehicle according to the present invention.

FIG. 2 is a flowchart showing a method of controlling the air conditioner for the electric vehicle shown in FIG.

[Explanation of symbols]

1 ... Heat pump cycle, 3 ... Inside heat exchanger, 10
... air conditioning unit, 20 ... PTC heater, 30 ... control device, 32 ... outside air sensor, 33 ... DEF command switch.

Claims (3)

[Claims] 1. An air conditioning unit and a heat pump cycle for cooling and heating by circulating a heat medium are formed, and a heat exchanger inside the vehicle arranged inside the air conditioning unit and a heat exchanger on the downstream side of the heat exchanger inside the vehicle. An auxiliary heater provided, DEF mode command means for instructing the air conditioning unit to perform DEF mode operation for blowing air to the inner surface of the windshield, and the DE.
Control for controlling the air conditioning unit so as to drive at least one of the heat pump cycle and the auxiliary heater based on a command signal from the F mode commanding means and blow air to the inner surface of the windshield to remove the fog. An air conditioner for an electric vehicle, comprising: 2. The control device drives at least one of a heat pump cycle and an auxiliary heater to operate the air conditioning unit in a DEF mode based on the outside air temperature. Air conditioning system for electric vehicles. 3. The control device drives at least one of a heat pump cycle and an auxiliary heater to operate the air conditioning unit in a DEF mode based on the operation mode of the heat pump cycle. Alternatively, the air conditioner for an electric vehicle described in 2.