JPH07266852A - Air conditioner for electric vehicle - Google Patents

Abstract

PURPOSE:To provide an air conditioner for an electric vehicle which is rare to be failured and has good response property for operation. CONSTITUTION:When a maximum set value is set to a temperature setting unit 20, a drive frequency controller 23 corrects it to the reference drive frequency lower than the drive frequency corresponding to the maximum set value. Further, the drive frequency controller 23 controls a compressor 4 along a locus varied approximately linearly from the reference drive frequency to the minimum drive frequency corresponding to the minimum set value of the temperature setting unit 20.

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 equipped with a heat pump cycle.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner for an electric vehicle equipped with a heat pump cycle, for example, as shown in FIG. 4, an air conditioner unit 10 in which a heat pump cycle 1 is assembled is controlled by a temperature setting unit 20. There is.

The heat pump cycle 1 comprises a vehicle exterior heat exchanger 2 arranged in the front part of the vehicle body, a vehicle interior heat exchanger 3 arranged in an air conditioning unit 10 in the vehicle interior front part, a compressor 4, and 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 temperature setting unit 20, which will be described later, switches the four-way valve 5 as shown by the solid line in FIG. 4 and drives the compressor 4 via the inverter 22 to make the heat exchange medium high temperature and high pressure, and the solid line in FIG. After the heat is dissipated by the heat exchanger 3 inside the vehicle through the four-way valve 5 according to the arrow shown in FIG. To the compressor 4 for circulation. 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 temperature setting unit 20 switches the four-way valve 5 as shown by the dotted line in FIG.
Similarly to the above, the compressor 4 is driven to make the heat exchange medium a high temperature and high pressure, and heat is radiated by the vehicle exterior heat exchanger 2 via the four-way valve 5 according to the arrow shown by the dotted line in FIG. The pressure is reduced with, and heat is absorbed from the air passing through the inside of the air conditioning unit 10 in the vehicle interior heat exchanger 3, and the four-way valve 5
Is returned to the compressor 4 via the accumulator 7 and circulated. 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 temperature setting unit 20.

On the downstream side of the blower 13, the inside heat exchanger 3 of the heat pump cycle 1 is constructed.
Are arranged.

An air mix damper 17 is formed downstream of the vehicle interior heat exchanger 3 to form two flow passages 16a and 16b, and one of the flow passages 16b is blown with air. An adjustment damper 18 that adjusts the air volume is provided. When the air mix damper 17 rotates based on the control signal of the temperature setting unit 20, the adjustment damper 18 rotates in response to the control signal based on the control signal.

A DEF damper 1 rotated by an actuator (not shown) is provided on the downstream side of the flow paths 16a and 16b.
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 from the blow-out port to which the damper 19a is attached to the inner surface of the front window (not shown).

In the temperature setting unit 20, when an occupant slides the temperature setting lever 21 to set a desired vehicle interior temperature, an outside air sensor, an inside air sensor, not shown,
Also, it is operated based on various conditions input from the temperature sensor 15 and the like, and the blast temperature and the blast amount are controlled so as to feel comfortable. In particular, by operating a changeover switch (not shown), the dampers 19a, 1
By rotating 9b and 19c, the desired air outlet is opened and closed.

In the case of heating and cooling with the air conditioner having the above-mentioned configuration, as shown in the flowchart of FIG. 5, the cooling and heating switch (not shown) of the temperature setting unit 20 is turned on in step S30, and the cooling and heating operation is performed in step 31. Start. Next, in step S32, the inverter 22 drives the compressor 4 according to the drive frequency set by the temperature setting lever to perform cooling / heating.

[0012]

However, in the above-described air conditioner for an electric vehicle, the temperature setting lever 21 of the temperature setting unit 20 is manually adjusted by the occupant.
Therefore, even if the set temperature is constant, the load state on the compressor 4 changes due to the change in the environment. In particular, when the occupant sets the lever 21 to the maximum set value, the compressor 4 may be overloaded due to changes in the environment. As long as the lever 21 is set to the maximum setting value, the overload condition as described above continues, which may cause a failure.

Therefore, in order to avoid the failure of the compressor 4 as described above, a protection device (not shown) is provided to drive the compressor 4 when the overload condition of the compressor 4 continues for a predetermined time. Although a method of stopping is proposed, this method has a problem in that the compressor 4 suddenly stops and the temperature inside the vehicle fluctuates rapidly, which gives an occupant anxiety and discomfort.

As another method of avoiding the failure of the compressor 4, for example, as shown in the graph of FIG. 6, when the compressor 4 is overloaded, the drive frequency of the compressor 4 is set to a predetermined reference. A method (A → B → C) of limiting the driving frequency and providing a dead zone for control is proposed. In this method, an occupant uses the lever 21
Since the air blowing temperature of the air blown out by the air conditioning unit 10 does not change even if is slid in the dead zone, the temperature inside the vehicle does not change, and the operation response is poor.

An air conditioner for an electric vehicle according to the present invention is
In view of the above problems, it is an object of the present invention to provide an air conditioner for an electric vehicle that is hard to break down and has good operation response.

[0016]

In order to achieve the above object, an air conditioner for an electric vehicle according to the present invention comprises a heat pump cycle consisting of a compressor and a heat exchanger inside the vehicle, and a heat exchanger inside the vehicle of the heat pump cycle. The built-in air conditioning unit, capacity setting means for controlling this air conditioning unit, temperature sensor for detecting the temperature of the vehicle interior heat exchanger, and based on the detection signal of this temperature sensor, depending on the setting of the capacity setting means. Drive frequency control means for controlling the drive frequency of the compressor, and when the capacity setting means has a maximum set value, the drive frequency control means sets the drive frequency of the compressor corresponding to the maximum set value to a lower standard. The maximum drive frequency is corrected to the frequency and the minimum set value of the capacity setting means is calculated from this maximum drive frequency. Certain to the minimum driving frequency of the corresponding compressor as configured to control along a substantially linearly varying trajectory. When the set value of the capacity setting means exceeds a reference value corresponding to the reference drive frequency of the compressor and reaches a specific range, the drive frequency control means sets the drive frequency corresponding to the set value to the reference value. The frequency is corrected to the maximum drive frequency of the compressor, and the maximum drive frequency to the minimum drive frequency of the compressor corresponding to the minimum set value of the capacity setting means is controlled along a substantially linear trajectory. You may comprise.

[0017]

Therefore, according to claims 1 and 2 of the present invention,
The compressor is driven at a drive frequency of a locus that changes substantially linearly between the maximum drive frequency that is the reference drive frequency of the compressor and the minimum drive frequency that corresponds to the minimum set value of the capacity setting means.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings of FIGS. As shown in FIG. 1, the air conditioner for an electric vehicle according to the present embodiment is almost the same as the above-described conventional example, except that the temperature setting unit 2 is different.
Drive frequency control device 23 is connected between 0 and the inverter 22, and the temperature sensor 15 connected to the drive frequency control device 23 is connected to the drive frequency control device 23.
Is a point arranged near the downstream side of the vehicle interior heat exchanger 3. Then, the reference drive frequency is set based on the detection signal of the temperature sensor 15, and the drive frequency control device 2
3 controls the inverter 22 to drive the compressor 4, so that the compressor 4 is controlled so as not to be overloaded.

A control method for cooling and heating the air conditioner according to the present invention will be described. First, during cooling, as shown in FIG. 2, a cooling switch (not shown) is turned on in step S1, and the cooling operation is started in step S2. Then, in step S3, it is determined whether or not the temperature setting lever 21 has the maximum set value, and when it is determined in step S3 that the lever 21 has not set the maximum set value, the compressor 4 is overloaded. Since there is no risk of a load condition, the drive frequency control device 23 outputs a drive signal according to the set value set by the lever 21 to the inverter 22, and the compressor 4 according to the set value set by the lever 21.
Is driven.

On the other hand, in step S3, the temperature setting lever 2
When it is determined that 1 has set the maximum set value, it is determined in step S5 whether or not the temperature of the vehicle interior heat exchanger 3 is equal to or higher than a predetermined value (for example, 3 ° C.), and it is determined that the temperature is not higher than the predetermined value. If determined, the drive frequency output from the inverter 22 is limited by the drive frequency controller 23 in step S6 so that the drive frequency becomes the reference frequency (for example, 60 Hz), the compressor 4 is not overloaded, and the inside of the vehicle is cooled. Control not to pass. Therefore, according to the present embodiment, when the lever 21 is returned, the compressor 4 is controlled along the alternate long and short dash line (C → A) shown in FIG.

If it is determined in step S5 that the value is equal to or more than the predetermined value, it is considered that the inside of the vehicle is not sufficiently cooled. Therefore, in step S7, the maximum drive corresponding to the maximum set value set by the lever 21 is set. The drive frequency controller 23 controls the inverter 22 so as to drive the compressor 4 at a frequency, and drives the compressor 4.

Thereafter, similar control is repeated. Then, while the compressor 4 is being driven, if the detection value of the temperature sensor 15 becomes equal to or more than a predetermined value in step S5, the drive frequency control device 23 outputs the maximum value so that the inverter 22 outputs according to the set value of the lever 21. The frequency is output and the compressor 4 is driven at the maximum drive frequency.

Next, during heating, as shown in FIG. 3, a heating switch (not shown) is turned on in step S10, and heating operation is started in step S11. Then, in step S12, it is determined whether or not the temperature setting lever 21 has the maximum set value, and when it is determined in step S12 that the lever 21 has not set the maximum set value, the compressor 4 is overloaded. Since there is no possibility of becoming a state, in step 13, the drive frequency control device 23 outputs a drive signal according to the set value set by the lever 21 to the inverter 22,
The compressor 4 is driven at a drive frequency that is equal to the drive frequency corresponding to the set value set by the lever 21.

On the other hand, if it is determined in step S12 that the temperature setting lever 21 has set the maximum set value,
In step S14, it is determined whether the temperature of the vehicle interior heat exchanger 3 is lower than a predetermined temperature (for example, 60 ° C.), and if it is determined that the temperature is not lower than the predetermined temperature, the inside of the vehicle is warmed to a desired temperature or higher. Therefore, the drive frequency control device 23 limits the drive frequency of the compressor 4 to 60 Hz via the inverter 22 in step S15.
Therefore, similar to the control method during cooling described above, the lever 2
When 1 is restored, the compressor 4 is controlled along the locus of the drive frequency that changes in a substantially linear manner.

Further, when it is determined in step S14 that the temperature is lower than the predetermined temperature, it is considered that the inside of the vehicle has not reached the desired temperature. Therefore, in step S16, the drive frequency control device 23 operates the inverter 22 through the inverter 22. Lever 21
The compressor 4 is driven by outputting the maximum drive frequency according to the set value set in step 3.

Thereafter, similar control is repeated. If the detected value of the temperature sensor 15 becomes less than a predetermined value in step S14 while the compressor 4 is being driven, the drive frequency control device 23 sets the maximum drive frequency according to the set value of the lever 21, and the compressor 4 Drive at maximum frequency.

In the above-described embodiment, the case where the lever 21 of the temperature setting unit 20 is set to the maximum set value has been described, but the present invention is not limited to this. For example, the lever 21 is set in the dead zone shown in FIG. Even when the set value due to is stopped, the reference drive frequency corresponding to the stopped set value is set as the maximum drive frequency, and between this maximum drive frequency and the minimum drive frequency corresponding to the minimum set value of the temperature setting unit 20. Is a trajectory that changes substantially linearly (in FIG. 6, D →
The compressor 4 may be driven according to A).

In the above embodiment, the case where the lever 21 is slid to set the set value has been described. However, the present invention is not limited to this, and the set value may be set by a dial. is there.

[0029]

As is apparent from the above description, according to the electric vehicle air conditioners of claims 1 and 2 of the present invention, even if the occupant sets the capacity setting means to the maximum set value, The drive frequency control device limits the drive frequency for driving the compressor based on the detection value of the temperature sensor attached to the heat exchanger inside the vehicle during cooling and heating, so that the compressor does not become overloaded and malfunctions occur. Less likely to occur. Further, since the drive frequency control device controls the compressor along a trajectory that changes substantially linearly from the reference drive frequency, which is the maximum drive frequency of the compressor, to the minimum drive frequency, the dead band as in the conventional example is restored at the time of restoration. Operation responsiveness is improved. Further, according to claims 1 and 2 of the present invention, the control can be performed only by the detected value of the temperature sensor attached to the vehicle interior heat exchanger,
Since it is not necessary to perform complicated temperature control by a plurality of temperature sensors such as an outside air sensor, it is possible to avoid an overload state with a simple configuration and reduce production costs. Further, according to the second aspect, even if the capability setting means is not set to the maximum setting value, the dead zone as in the conventional example is eliminated, so that there is an effect that the operation response is improved even in the intermediate region. .

[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 flow chart diagram for explaining a control method during cooling of the electric vehicle air conditioner shown in FIG.

3 is a flowchart for explaining a control method during heating of the air conditioner for the electric vehicle shown in FIG.

FIG. 4 is a schematic diagram of an air conditioner for an electric vehicle according to a conventional example.

5 is a flowchart for explaining a control method of the air conditioner for the electric vehicle shown in FIG.

FIG. 6 is a graph for explaining a method of controlling an air conditioner for an electric vehicle.

[Explanation of symbols]

1 ... Heat pump cycle, 10 ... Air conditioning unit, 15
... temperature sensor, 20 ... temperature setting unit, 21 ... temperature setting lever, 23 ... drive frequency control device.

Claims (2)

[Claims] 1. A heat pump cycle comprising a compressor and a heat exchanger inside the vehicle, an air conditioning unit incorporating the heat exchanger inside the heat pump cycle, capacity setting means for controlling the air conditioning unit, and heat exchange inside the vehicle. A temperature sensor for detecting the temperature of the container, and a drive frequency control means for controlling the drive frequency of the compressor according to the setting of the capacity setting means on the basis of the detection signal of the temperature sensor. In the case of a value, the drive frequency control means corrects the drive frequency of the compressor corresponding to the maximum set value to a lower reference frequency to obtain the maximum drive frequency, and from this maximum drive frequency, the capacity setting means Control along a trajectory that changes linearly up to the minimum drive frequency of the compressor corresponding to the minimum set value An air conditioner for an electric vehicle, which is characterized by: 2. A heat pump cycle comprising a compressor and a heat exchanger inside the vehicle, an air conditioning unit incorporating the heat exchanger inside the heat pump cycle, capacity setting means for controlling the air conditioning unit, and heat exchange inside the vehicle. A temperature sensor for detecting the temperature of the container, and a drive frequency control means for controlling the drive frequency of the compressor according to the setting of the capacity setting means based on the detection signal of the temperature sensor. When the drive frequency exceeds the reference value corresponding to the reference drive frequency of the compressor and reaches a specific range, the drive frequency control means corrects the drive frequency corresponding to the set value to the reference frequency to drive the maximum drive of the compressor. The frequency and the maximum drive frequency from the maximum drive frequency of the compressor corresponding to the minimum set value of the capacity setting means. An air conditioner for an electric vehicle, which controls up to a small driving frequency along a substantially linearly changing trajectory.