JP3316014B2 - 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, and more particularly to noise reduction of a compressor of the air conditioner.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner for an electric vehicle, a compressor for air conditioning normally rotates at a speed based on temperature control and frost prevention control, and has a speed independent of a vehicle speed and a blower air volume. Rotate with. That is, even when the vehicle speed is low or the air volume of the blower is small, the compressor may be rotating at a high speed.

[0003]

In a conventional air conditioner for an electric vehicle, the noise of the vehicle is generally very quiet. Therefore, even when the air volume of the blower is small or the vehicle is stopped, the compressor is not used. It rotated at high speed, and its vibration noise was harsh.

An object of the present invention is to provide an air conditioner for an electric vehicle which reduces the vibration noise level of a compressor which becomes annoying when the vehicle stops or the blower air volume is reduced in view of the above problems. It is in.

[0005]

According to the present invention, in an electric vehicle running by driving a vehicle driving motor by a battery power source, a blower motor for air conditioning in a vehicle compartment driven by the battery power source and a terminal of the blower motor are provided. Means for detecting a voltage, a controller for air conditioning to which a voltage detection signal is supplied from the detector, and a motor for driving a compressor driven by the battery power source, the number of revolutions being controlled by the controller for air conditioning. , And wherein the air-conditioning control device sets an upper limit value of the number of revolutions of the electric motor according to the voltage detection signal.

The air-conditioning control device controls the rotation speed of the electric motor to be lower than the upper limit value when the terminal voltage is lower than a predetermined value.

According to the present invention, there is further provided a rotation sensor for detecting the number of rotations of the vehicle drive motor, and the control device for air conditioning is provided when the detection signal from the rotation sensor is equal to or less than a predetermined value corresponding to when the vehicle is stopped. Thus, an air conditioner for an electric vehicle in which an upper limit value is set for the number of revolutions of the electric motor is obtained.

[0008]

FIG. 1 is a block diagram of an air conditioner for an electric vehicle according to an embodiment of the present invention. The direct current from the battery 11 is supplied in parallel to a main circuit controller 12, an air conditioning controller 13, and an air conditioning unit 14 of the electric vehicle. The main circuit control device 12 is a vehicle drive motor (not shown)
Alternatively, it is a device that controls the main circuit of the electric vehicle including the air-conditioning control device 13. The air conditioning control device 13 is a device that controls the air conditioning unit 14 by microcomputer control.
The air conditioning unit 14 includes a blower motor 15 that sends cooling air into the vehicle interior. A direct current from the battery 11 is supplied to the blower motor 15 via the resistance device 16 and the changeover switch 17. The changeover switch 17 is connected to the resistance device 16 and adjusts the voltage value applied between the terminals of the blower motor 15 by switching the resistance value.

When the value of the voltage applied between the terminals of the blower motor 15 changes, the number of revolutions of the motor changes, thereby adjusting the amount of cooling air sent into the vehicle interior. The voltage value applied between the terminals of the blower motor 15 is
8 and the detection output is output from the air conditioning controller 13.
As one of its input signals. The detection signal of the temperature sensor 19 that detects the temperature in the passenger compartment to be cooled is also input to the air-conditioning control device 13.

FIG. 2 is a block diagram showing a refrigeration cycle of the air conditioner of FIG. The refrigerant circulation circuit includes a compressor 22 driven by an electric motor 21 for driving the compressor, a condenser 2
3, a receiver 24, an expansion valve 25, and an evaporator 26 are connected in series. The condenser 23 has a condenser fan motor 27.
However, the blower motor 15 is arranged in the evaporator 26.

FIG. 3 is a flowchart of an operation program of the air-conditioning control device 13. The operation of the air-conditioning device for an electric vehicle according to one embodiment of the present invention will be described with reference to FIG. The air-conditioning control device 13 determines a function f set in advance by the ratio (V / V ₀ ) between the terminal voltage V of the blower motor 15 and the reference voltage V ₀ detected by the voltage sensor 18 in step S1.
(V / V ₀ ), the rotation speed Nmax of the electric motor 21
Is determined (step S2).

Next, the air-conditioning control device 13 controls the temperature sensor 1 in the temperature control rotation speed calculation loop (step S3).
The number of rotations Ncal required for the electric motor 21 to realize the optimum cooling temperature is determined using the detection signal of No. 9. Then, in a comparison step S4, both sizes are compared. As a result, when the rotation speed Ncal is smaller than Nmax, the rotation speed Ncal is changed to the actual rotation speed Nne of the electric motor 21.
xt.

On the other hand, when the rotation speed Ncal is equal to or higher than Nmax, the rotation speed Nmax is changed to the actual rotation speed Nne of the electric motor 21.
xt. That is, the air-conditioning control device 13 controls the rotation of the compressor driving motor 21 so that the vibration noise of the compressor 22 is always masked to the blower noise in accordance with the ratio of the terminal voltage V of the blower motor 15 to the reference voltage V _0. Possible upper limit N
When the rotational speed of the blower motor 15 is lower than a predetermined value, the actual rotational speed N of the electric motor 21 is determined.
Next is controlled to be equal to or less than the upper limit.

In the above embodiment, the number of revolutions of the motor for driving the compressor is directly determined. However, the voltage applied to the motor, the duty ratio of the current or the frequency may be controlled. In the air-conditioning control device 13, the ratio between the detected value of the terminal voltage from the voltage sensor 18 and the reference voltage is used. However, the difference or the detected value itself may be used, The voltage drop of the current supplied to the power supply 15 may be detected and used.

FIG. 4 is a block diagram showing another embodiment of the air conditioner of the present invention, and FIG. 5 is a flowchart of an operation program of the control device. 4 has the same configuration as the device of FIG. 1 except that a vehicle drive motor 41 of an electric vehicle and a rotation sensor 42 for detecting the number of rotations of the vehicle drive motor 41 are added. Therefore, the same components as those of the apparatus of FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. Also, in FIG. 5, the same operation as in FIG. 3 is performed except for steps S11 to S13.

A rotation sensor 42 is provided in the air-conditioning control device 13 '.
Is supplied as an input signal (step S).
11). The air-conditioning control device 13 ′ compares the output e of the rotation sensor 42 with the reference voltage e ₀ corresponding to the time when the vehicle is stopped in step S12, and when the output e is equal to or lower than the reference voltage e ₀ , Figure 3 only when stopped
The actual rotation speed control of the electric motor 21 shown in FIG. That is, when the output e of the rotation sensor 42 is higher than the reference voltage e ₀ , the process proceeds to step S13 and the rotation speed Nm of the electric motor 21
By setting ax to infinity, the actual rotation speed control function of the electric motor 21 is stopped. The reason for this is that while the vehicle is running, the running noise is large and the noise of the compressor is masked, so that it is not necessary to control the actual rotation speed of the electric motor 21. Of course, when the output e of the rotation sensor 42 is equal to or lower than the reference voltage e ₀ , the control is performed such that the actual rotation speed Nnext of the electric motor 21 is equal to or lower than the upper limit, as in the above-described embodiment.

[0017]

According to the air conditioner for an electric vehicle of the present invention, the upper limit of rotation of the motor for driving the compressor is controlled so that the vibration noise of the compressor is always masked by the blower noise. Harsh vibration noise caused by the compressor is avoided.

By controlling the rotation of the compressor driving motor only when the vehicle is at a standstill, only the temperature control loop is controlled when the vehicle is running in which the vibration noise of the compressor is masked by the vehicle running noise. Determines the number of revolutions of the compressor, so that an appropriate cooling capacity can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a refrigeration cycle of a vehicle air conditioner to which the present invention is applied.

FIG. 3 is a flowchart illustrating an operation flow of the embodiment shown in FIG. 1;

FIG. 4 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation flow of the embodiment shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Battery 15 Blower motor 16 Resistance device 17 Changeover switch 18 Voltage sensor 19 Temperature sensor 23 Capacitor 24 Receiver 25 Expansion valve 26 Evaporator 27 Capacitor fan motor 42 Rotation sensor

Claims (3)

(57) [Claims] 1. An electric vehicle that travels by driving a vehicle drive motor with a battery power supply, a blower motor for vehicle interior air conditioning driven by the battery power supply, means for detecting a terminal voltage of the blower motor, and the detection means An air-conditioning control device to which a voltage detection signal is supplied, and a compressor-driving motor driven by the battery power source, the number of revolutions of which is controlled by the air-conditioning control device, An air conditioner for an electric vehicle, wherein an upper limit value of the number of revolutions of the electric motor is set according to the voltage detection signal. 2. The electric device according to claim 1, wherein the air-conditioning control device controls the rotation speed of the electric motor to be lower than the upper limit value when the terminal voltage is lower than a predetermined value. Automotive air conditioners. 3. The air-conditioning control device further comprises a rotation sensor for detecting a rotation speed of the vehicle drive motor, wherein the air-conditioning control device controls the rotation of the electric motor when a detection signal from the rotation sensor is equal to or less than a predetermined value corresponding to when the vehicle is stopped. 3. The air conditioner for an electric vehicle according to claim 2, wherein an upper limit is set for the number.