JP3335466B2 - Electric vehicle air conditioner - Google Patents

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 having a heat pump cycle.

[0002]

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

[0003] The heat pump cycle 1 comprises an outside heat exchanger 2 disposed in the front of the vehicle body, an inside heat exchanger 3 disposed in an air conditioning unit 10 in the front of the vehicle, a compressor 4, a four-way valve. 5, a capillary tube 6, and an accumulator 7.

[0004] When the interior of the vehicle is heated by the heat pump cycle 1, it is performed by circulating a heat exchange medium 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, thereby setting the heat exchange medium to high temperature and high pressure. In accordance with the arrow shown by the arrow, after radiating heat in the vehicle interior heat exchanger 3 via the four-way valve 5, depressurizing the capillary tube 6, absorbing heat from the outside air in the vehicle outside heat exchanger 2, and again passing the accumulator 7 from the four-way valve 5 And circulates back to the compressor 4 via. As a result, the air sucked into the air conditioning unit 10 is heated by the in-vehicle heat exchanger 3 and is sent out as warm air into the vehicle.

[0005] When the interior 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 a dotted line in FIG.
In the same manner as described above, the compressor 4 is driven to set the heat exchange medium to high temperature and high pressure, and the heat is radiated by the outside heat exchanger 2 through the four-way valve 5 according to the arrow shown by the dotted line in FIG. And the heat is absorbed from the air passing through the air conditioning unit 10 in the heat exchanger 3 inside the vehicle.
Is returned to the compressor 4 via the accumulator 7 and circulated. Thereby, the air sucked into the air conditioning unit 10 is cooled by the heat exchanger 3 on the inside of the vehicle, and is sent out as cold air into the vehicle.

On the other hand, the air conditioning unit 10 incorporating the heat exchanger 3 inside the heat pump cycle 1 is provided with an intake damper 11 for switching between inside and outside air on the upstream side of the air conditioning unit 10 to air-condition the outside air 12a or the inside air 12b. The suction is selectively performed in the unit 10. The air is sucked into the air conditioning unit 10 by rotating a blower 13 provided downstream of the intake damper 11 by a motor 14 connected to a temperature setting unit 20.

Further, downstream of the blower 13, the heat exchanger 3 inside the heat pump which constitutes the heat pump cycle 1 is provided.
Is arranged.

An air mix damper 17 is provided downstream of the heat exchanger 3 so as to form two flow paths 16a, 16b. The air mix damper 17 is provided at one of the outlets of the flow path 16b. An adjustment damper 18 for adjusting the air volume is provided. When the air mix damper 17 rotates based on a control signal of the temperature setting unit 20, the adjustment damper 18 rotates in accordance with the rotation based on the control signal.

A DEF damper 1 rotated by an actuator (not shown) is provided downstream of the flow paths 16a and 16b.
9a, a VENT damper 19b, and a HEAT damper 19c are provided, and air is blown into the vehicle from respective outlets. In particular, the DEF
From the outlet to which the damper 19a is attached, air is blown out to the inner surface of a front window (not shown).

When the occupant slides the temperature setting lever 21 to set the desired temperature inside the vehicle, the temperature setting unit 20 includes an outside air sensor, an inside air sensor (not shown),
In addition, a calculation is performed based on various conditions input from the temperature sensor 15 and the like, and the blowing temperature and the blowing amount are controlled so that the user feels comfortable. In particular, by operating a changeover switch (not shown), the aforementioned dampers 19a, 1
9b and 19c are rotated to open and close a desired air outlet.

When the air conditioner having the above-described configuration is used for cooling and heating, as shown in the flowchart of FIG. 5, a 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 and heating.

[0012]

However, in the electric vehicle air conditioner described above, 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 a 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 a change in environment. As long as the lever 21 is set to the maximum set value, the above-described overload state continues, which may cause a failure.

For this reason, in order to avoid the failure of the compressor 4 as described above, a protection device (not shown) is provided, so that when the overload state of the compressor 4 continues for a predetermined time, the compressor 4 is driven. A method of stopping the vehicle has been proposed. However, this method has a problem that the compressor 4 suddenly stops and the temperature inside the vehicle fluctuates rapidly, thereby giving a feeling of anxiety and discomfort to the occupant.

As another method for 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 value. A method (A → B → C) has been proposed in which the drive frequency is limited and a dead band is provided for control (A → B → C).
When the air conditioner is slid in the dead zone, the temperature of the air blown by the air-conditioning unit 10 does not change, so that the temperature inside the vehicle does not change, and the operation responsiveness is poor.

An air conditioner for an electric vehicle according to the present invention comprises:
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 less likely to fail and has a 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 comprising a compressor and a heat exchanger inside a vehicle, and a heat exchanger inside the heat pump cycle of the heat pump cycle. An air-conditioning unit incorporated therein, a capacity setting means for controlling the air-conditioning unit, a temperature sensor for detecting the temperature of the heat exchanger inside the vehicle, and a detection signal from the temperature sensor. A drive frequency control means for controlling a drive frequency of the compressor, wherein when the set value of the capacity setting means exceeds a reference value corresponding to a reference drive frequency of the compressor and reaches a specific range, the drive frequency control means However, while correcting the drive frequency corresponding to the set value to the reference frequency and setting the maximum drive frequency of the compressor It is constituted to control along from the maximum driving frequency to the minimum driving frequency of the compressor corresponding to a minimum set value of the capacity setting means to substantially linearly varying trajectory.

[0017]

Therefore, according to the first aspect of the present invention, it changes substantially linearly between the maximum drive frequency which is the reference drive frequency of the compressor and the minimum drive frequency corresponding to the minimum set value of the capacity setting means. The compressor is driven at the driving frequency of the locus.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will now be described with reference to FIGS. As shown in FIG. 1, the air conditioner for an electric vehicle according to the present embodiment is almost the same as the conventional example described above.
0 and an inverter 22, a drive frequency control device 23 is connected, and a temperature sensor 15 connected thereto is connected.
Is disposed near the downstream side of the in-vehicle heat exchanger 3. Then, a reference driving frequency is set based on the detection signal of the temperature sensor 15 and the driving frequency control device 2
When the compressor 3 drives the compressor 4 by controlling the inverter 22, 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, at the time of cooling, as shown in FIG. 2, a cooling switch (not shown) is turned on in step S1, and a cooling operation is started in step S2. Then, in step S3, it is determined whether or not the temperature setting lever 21 has reached the maximum set value, and if it is determined in step S3 that the lever 21 has not set the maximum set value, the compressor 4 Since there is no possibility of a load state, 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 operates according to the set value set by the lever 21.
Is driven.

On the other hand, at step S3, the temperature setting lever 2
If it is determined that 1 has set the maximum set value, it is determined in step S5 whether or not the temperature of the inside heat exchanger 3 is equal to or higher than a predetermined value (for example, 3 ° C.). If it is determined, the drive frequency output from the inverter 22 is limited by the drive frequency control device 23 to a reference frequency (for example, 60 Hz) in step S6, so that the compressor 4 does not become overloaded and the inside of the vehicle cools down. Control so that it is not too late. Therefore, according to the present embodiment, when the lever 21 is returned, the compressor 4 is controlled along the dashed 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 interior of the vehicle is not yet 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 control device 23 controls the inverter 22 so as to drive the compressor 4 with the frequency, and drives the compressor 4.

Thereafter, similar control is repeated. If the detected value of the temperature sensor 15 becomes equal to or more than the predetermined value in step S5 while the compressor 4 is driving, the drive frequency control device 23 sets the maximum value so that the inverter 22 outputs the value 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, at the time of heating, as shown in FIG. 3, a heating switch (not shown) is turned on in step S10, and a 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. If 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 being in a state, the drive frequency control device 23 outputs a drive signal according to the set value set by the lever 21 to the inverter 22 in step 13,
The compressor 4 is driven at a drive frequency according 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 or not the temperature of the inside heat exchanger 3 is lower than a predetermined temperature (for example, 60 ° C.). If it is determined that the temperature is not lower than the predetermined temperature, the inside of the vehicle warms up to a desired temperature or higher. Therefore, in step S15, the drive frequency control device 23 restricts the drive frequency of the compressor 4 to 60 Hz via the inverter 22 in step S15.
Therefore, like the control method at the time of cooling described above, the lever 2
When 1 is returned, the compressor 4 is controlled along the trajectory of the drive frequency that changes substantially linearly.

Further, if 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, so that the drive frequency control device 23 Lever 21
The compressor 4 is driven by outputting the maximum drive frequency according to the set value set in the above.

Thereafter, similar control is repeated. If the detected value of the temperature sensor 15 becomes smaller than a predetermined value in step S14 during driving of the compressor 4, the driving frequency control device 23 sets the maximum driving frequency according to the set value of the lever 21, and At the 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. However, the present invention is not limited to this. For example, the lever 21 may be set in the dead zone shown in FIG. Even when the set value by the stop is stopped, the reference drive frequency corresponding to the stopped set value is set as the maximum drive frequency, and the reference drive frequency between the maximum drive frequency and the minimum drive frequency corresponding to the minimum set value of the temperature setting unit 20 is set. In a substantially linearly changing locus (D →
The compressor 4 may be driven according to A).

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

[0029]

As is apparent from the above description, according to the air conditioner for an electric vehicle according to the first aspect of the present invention, even when the occupant sets the capacity setting means to the maximum set value, the air conditioner is operated at the time of cooling and heating. 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, so that the compressor is not overloaded and failures do not easily occur. Become. In addition, the drive frequency control device controls the compressor along a locus that changes substantially linearly from the reference drive frequency, which is the maximum drive frequency of the compressor, to the minimum drive frequency. And operation responsiveness is improved. Further, according to the first aspect of the present invention, it is possible to control only by the detection value of the temperature sensor attached to the heat exchanger inside the vehicle, and it is necessary to perform complicated temperature control by a plurality of temperature sensors such as an inside air sensor and an outside air sensor. Since there is no such configuration, an overload state can be avoided with a simple configuration, and the production cost can be reduced. According to the first aspect, even when the capability setting means is not set to the maximum setting value,
Since there is no dead zone as in the conventional example, there is an effect that the operation responsiveness is improved even in the intermediate region.

[Brief description of the drawings]

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

FIG. 2 is a flowchart for explaining a control method of the electric vehicle air conditioner shown in FIG. 1 during cooling.

FIG. 3 is a flowchart illustrating a control method of the electric vehicle air conditioner shown in FIG. 1 during heating.

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

FIG. 5 is a flowchart for explaining a control method of the electric vehicle air conditioner shown in FIG. 4;

FIG. 6 is a graph for explaining a control method of the 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.

Continuation of the front page Examiner Sano Shun (56) References JP-A-4-151318 (JP, A) JP-A-4-106355 (JP, A) JP-A-7-144530 (JP, A) JP-A-4 JP-A-257726 (JP, A) JP-A-4-169322 (JP, A) JP-A-60-120127 (JP, A) JP-A-63-161344 (JP, A) JP-A-58-78035 (JP, A) (58) Investigated field (Int.Cl. ⁷ , DB name) B60H 1/32 623 B60H 1/00 F25B 1/00 361 F24F 11/02 102 B60H 1/22 B60H 1/00 101 B60H 1/32 622 B60H 1/32 624

Claims (1)

(57) [Claims] 1. A heat pump cycle comprising a compressor and a vehicle interior heat exchanger, an air conditioning unit incorporating the vehicle interior heat exchanger of the heat pump cycle, a capacity setting means for controlling the air conditioning unit, and the vehicle interior heat exchange A temperature sensor for detecting the temperature of the vessel, and a drive frequency control means for controlling a drive frequency of the compressor in accordance with the setting of the capacity setting means based on a detection signal of the temperature sensor; However, when the specific frequency exceeds a 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 and drives the compressor to the maximum drive frequency. Frequency, and from the maximum drive frequency, the compressor corresponding to the minimum set value of the capacity setting means. Electric motor-vehicle air-conditioning system and controls along a trajectory which varies up to a small drive frequency substantially linearly.