JPH10193956A - Air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electric noise radiation despite of a small-sized, light- weight, and low-cost device by connecting a low-pass high frequency filter between DC voltage generation means and an electric compressor and shielding electromagnetic radiation from respective electric circuits including the electric compressor and respective connecting power supplies. SOLUTION: A low-pass high frequency filter 3 is connected between a battery 1 and an electric compressor drive 5, a shield power supply line 9 is a first power source line 2, and a case of the electric compressor drive device 5 is made of a metal, etc., of electromagnetic shielding power. The case of electric compressor 7 is made of metal and the case of a low-pass high frequency filter 3 is also made of a metal, etc., having an electromagnetic shielding power so that the direct electric noise radiation form each inside can be shielded. On the other hand, the shield power supply line 9, the shield motor line 10, etc., are used and electrically connected to respective cases so that the electric noise is prevented from being leaked out to the power lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor driving device for driving an electric compressor by a DC power source such as a battery, and an air conditioner for an automobile having an electric compressor.

[0002]

2. Description of the Related Art In an automotive air conditioner equipped with an electric compressor drive for driving an air-conditioning electric compressor with DC power, the electric compressor drive for driving the air-conditioning electric compressor supplies a large current to the electric compressor. Therefore, the electric noise is large and interferes with the on-vehicle radio.

[0003] Therefore, as shown in the conventional electric noise countermeasure diagram of FIG. 7, the case of the electric compressor drive device 5 and the electric compressor 7 is made of metal, and the electric compressor drive device 5 and the electric compressor drive device 5
Electric compressor drive 5 and electric compressor 7
Is a shielded wire, and this shield is connected to a metal case of the electric compressor driving device 5 and the electric compressor 7.

[0004] In order to enhance the shielding property, a metal case of the electric compressor driving device 5 and the electric compressor 7 is connected to the vehicle body.

[0005]

In the above conventional case, the effect of the shield is exhibited only when the electric compressor 7, the electric compressor driving device 5, and the electric wires connecting them, including the battery 1, are shielded.

However, since the battery 1 is composed of about 30 12V batteries, the battery 1 has a large space and a high voltage (for example, about 300V).

For this reason, it is difficult to shield the battery 1 and the location of the battery 1 is not shielded. Therefore, electric noise is radiated from here.

Further, even if the battery 1 can be shielded, the battery 1 is large and large in order to maintain strength and space. Therefore, it becomes expensive.

The shield power supply line 9 is expensive because it is used for high voltage and large current. The shield power supply line 9 is long to connect the battery 1 to the electric compressor driving device 5. As a result, costs increase.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an air conditioner for a vehicle which is a small-sized, light-weight, low-cost device and can sufficiently prevent radiation of electric noise.

[0011]

According to the present invention, a low-pass high-frequency filter is connected between a DC voltage generating means and an electric compressor driving device, and each of the low-pass high-frequency filter, the electric compressor driving device and the electric compressor is connected. A shield member for shielding electromagnetic radiation from the electric circuit section and each connection wire.

[0012]

According to the present invention, a low-pass high-frequency filter is connected between a DC voltage generating means and an electric compressor driving device, and each of the low-pass high-frequency filter, the electric compressor driving device, and the electric compressor is connected. A shield member for shielding electromagnetic radiation from the electric circuit section and each connection wire.

Therefore, it is possible to prevent electromagnetic radiation from the low-pass high-frequency filter, the electric compressor driving device, the electric circuit of each electric compressor, and the connecting wires.

Further, since the low-pass high-frequency filter can prevent electric noise from being output from the electric compressor driving device to the DC voltage generating means, it is not necessary to shield the DC voltage generating means.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 shows an electric noise countermeasure diagram according to a first embodiment of the present invention. The difference from the conventional electric noise countermeasure diagram of FIG. 7 is that the low-pass high-frequency filter 3 is connected between the battery 1 and the electric compressor driving device 5, and the shield power supply line 9 becomes the first power supply line 2. That is the point.

The source of the electric noise is the electric compressor driving device 5. Therefore, the case of the electric compressor drive device 5 is made of a metal or the like having an electromagnetic shielding ability (a resin may be used as long as it has an electromagnetic shielding ability).

The case of the electric compressor 7 is also
Due to its structure (built-in motor, piston, etc.), metal (iron,
Aluminum). The case of the low-pass high-frequency filter 3 is also made of a metal or the like having an electromagnetic shielding ability (a resin may be used as long as it has an electromagnetic shielding ability).

Therefore, the electric compressor driving device 5,
Direct electric noise radiation from inside each of the electric compressor 7 and the low-pass high-frequency filter 3 is shielded.

On the other hand, a shielded power supply line 9 (having electromagnetic shielding capability) is provided between the low-pass high-frequency filter 3 and the electric compressor driving device 5 on the electric wire through which current flows, and the electric compressor driving device 5 and the electric compressor 7 A shielded motor wire 10 (having electromagnetic shielding capability) is used between the two, and electric noise radiation from the electric wire is shielded.

The shield portions of the shield power supply line 9 and the shield motor line 10 include an electric compressor driving device 5, an electric compressor 7, a low-pass high-frequency filter 3,
It is electrically connected to each case to prevent leakage of electric noise.

The characteristics of the low-pass high-frequency filter 3 are shown in FIG. 6 as a characteristic diagram of the low-pass high-frequency filter. Low frequency components are allowed to pass and high frequencies are not allowed to pass. Here, radio A
0.3 MHz or more is attenuated so as not to interfere with M broadcast.

Therefore, since electric noise does not leak to the power supply line, the first power supply line 2 does not need to be a shield line, and may be a normal power supply line.

The frequency component to be passed is set so that the operating current of the electric compressor driving device 5 can flow. Inverter circuit whose switching frequency is 10KHz
In this case, if the current is smoothed internally, the frequency may be 10 KHz or less.

FIG. 4 shows a first low-pass high-frequency filter circuit diagram according to the present invention, and FIG. 5 shows a second low-pass high-frequency filter circuit diagram according to the present invention. As shown. In FIG. 4, the choke action of the coil 17 and the bypass action of the capacitor 18 prevent outflow of electric noise (from the low-pass high-frequency filter 3 to the power supply line A2).

If the required characteristics can be achieved, the coil 17,
Only one of the capacitors 18 may be used. Further, not limited to this, various methods can be considered.

In FIG. 5, the coil 17 is compatible with the common mode, and the direction in which the voltage is induced is indicated by a black circle. Thereby, the influence on the operating current of the electric compressor drive device 5 can be reduced.

In FIG. 1, each case of the electric compressor driving device 5, the electric compressor 7, and the low-pass high-frequency filter 3 is electrically connected to the vehicle body 13 to enhance the electromagnetic shielding property. Since there are no leaking parts, it is not always necessary to connect each case to the vehicle body.

FIG. 2 shows an electrical noise countermeasure diagram according to a second embodiment of the present invention. The difference from the electric noise countermeasure diagram according to the first embodiment of the present invention shown in FIG. 1 is that an electric compressor driving device 5, an electric compressor 7, and a low-pass high-frequency filter 3 are surrounded by a shield case 8, and each case is Is a point that is electrically connected to the shield case 8 by a case and a shield case connection wire 15, and the shield wire is not used for the electric wire.

Direct electric noise radiation from inside the electric compressor drive device 5, electric compressor 7, and low-pass high-frequency filter 3 and electric noise radiation from electric wires are shielded by the shield case 8. Further, the low-pass high-frequency filter 3 prevents electric noise from leaking to the power supply line.

Here, the electric compressor driving device 5,
If the electric compressor 7 and the low-pass high-frequency filter 3 have high shielding properties, the case, the shield case connection line 15, the case, and the vehicle body connection line 14 are not necessarily required.

Further, a part may be taken out of the shield case 8. In that case, the electric wire that goes out of the shield case 8 (between the low-pass high-frequency filter 3 and the electric compressor 7) needs to be a shield wire.

FIG. 3 shows an electrical noise countermeasure diagram according to a third embodiment of the present invention. The difference from the circuit diagram of the automotive air conditioner according to the first embodiment of the present invention shown in FIG. 1 is that the electric compressor driving device 5 and the low-pass high-frequency filter 3 are integrated, and the low-pass high-frequency filter is built in. The point is that the electric compressor drive device 16 is provided, and the shield power supply line 9 is omitted.

The shielding property against electric noise is improved because the number of electric wire connection portions is reduced and the leakage of electric noise is reduced.
With this configuration, the case of the low-pass high-frequency filter 3,
The shield power supply line 9 becomes unnecessary and the size is reduced. Workability,
The cost is also improved.

It should be noted that the present invention is not limited to the above-described embodiment, and various methods are possible within a range satisfying the gist of the present invention.

[0036]

According to the present invention, a low-pass high-frequency filter is connected between the DC voltage generating means and the electric compressor driving device, and the electric circuit of each of the low-pass high-frequency filter, the electric compressor driving device, and the electric compressor is provided. And a shielding material for shielding electromagnetic radiation from the connecting wires and the respective connecting wires.

For this reason, it is possible to prevent electromagnetic radiation from the low-pass high-frequency filter, the electric compressor driving device, the electric circuit of each electric compressor, and the connecting wires.

Further, since the low-pass high-frequency filter can prevent electric noise from being generated from the electric compressor driving device to the DC voltage generating means, it is not necessary to shield the DC voltage generating means with a large, heavy and expensive shield device. Absent. An expensive shield line is not required between the DC voltage generating means and the low-pass high-frequency filter.

The electrical connection from each case to the vehicle body is as follows:
Since it is not always necessary, leakage of electric noise due to forgetting to connect or increasing the electric resistance of the connecting portion can be prevented.

Thus, a small, lightweight, low-cost device
Electric noise emission can be reliably prevented.

By integrating the electric compressor driving device and the low-pass high-frequency filter, further downsizing can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a countermeasure for electric noise according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a countermeasure against electric noise according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a measure against electric noise according to a third embodiment of the present invention.

FIG. 4 is a circuit diagram of a first low-pass high-frequency filter according to the present invention;

FIG. 5 is a circuit diagram of a second low-pass high-frequency filter according to the present invention;

FIG. 6 is a characteristic diagram of a low-pass high-frequency filter according to the present invention.

FIG. 7 is an explanatory diagram of a conventional countermeasure against electric noise.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Battery 2 1st power supply line 3 Low-pass high frequency filter 4 2nd power supply line 5 Electric compressor drive 6 Motor line 7 Electric compressor 8 Shield case 9 Shield power supply line 10 Shield motor line 12 Shield line, case connection line 13 Body 14 Case, Body connection line 15 Case, Shield case connection line 16 Electric compressor drive with built-in low-pass high-frequency filter 17 Coil 18 Capacitor

Claims (1)

[Claims] A DC voltage generator, an electric compressor, an electric compressor drive that is supplied with power from the DC voltage generator and drives the electric compressor, the DC voltage generator and the electric compressor drive. A low-pass high-frequency filter connected between the low-pass high-frequency filter, the electric compressor driving device, an electric circuit provided in each of the electric compressors, and an electric wire connecting each of the electromagnetic radiation, An air conditioner for an automobile, comprising a shielding material for shielding.