JPH0243762Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a motor drive circuit for an air control door for an air conditioner.

(Prior Art and its Problems) A conventional motor drive circuit for an air control door for an air conditioner is disclosed in, for example, Japanese Utility Model Application Publication No. 181607/1983. FIG. 3 shows a circuit in which the motor drive circuit disclosed in this prior art example is replaced with a simplified equivalent circuit.

That is, in FIG. 3, 1 is an air control door for controlling the blowing direction of air in an automobile air conditioner. It is possible to switch to three positions including the side blowing position 1c. A motor drive circuit 2 that drives the air control door 1 is configured to drive the air control door 1.
and a motor 3 for driving the three positions 1a, 1
Three contacts 5a, 5 corresponding to each of b, 1c
b, 5c, and the notch 4a of the rotating plate 4 that rotates in conjunction with the motor 3 connects the three contacts 5a, 5b,
5c, the switch mechanism 5 opens the contact and stops the motor 3. One end of the motor 3 is connected to a power source 6, and the other end is connected to a power source 6.
It is grounded via an NPN transistor 7,
The base of the transistor 7 is connected to a common terminal 5d of the switch mechanism 5 via a resistor, and the three contacts 5a, 5b, 5c are connected to a switch 8a, which is closed when the foot-side blow-out position 1a is selected.
It is connected to the power source 6 through a switch 8b that is closed when the foot and defrost side blowout positions 1b are selected, and a switch 8c that is closed when the defrost side blowout position 1c is selected.

In the conventional motor drive circuit described above, for example, when the foot side blowout position 1a is selected, the switch 8a
is closed, the base of the transistor 7 is connected to the power source 6, the NPN type transistor 7 is turned on, current flows to the motor 3, the motor 3 rotates, and the motor 3 moves the air control door 1 to the foot side blowout position. 1a and rotates the rotary plate 4. When the air control door 1 is driven to the foot side blowout position 1a, the notch 4a of the rotary plate 4 contacts the contact point 5.
a, the contact 5a opens and the connection between the base of the NPN transistor 7 and the power supply 6 is cut off,
NPN transistor 7 turns off and motor 3
stops. Footwell and defrost side air outlet position 1
Even if the air control door 1b or the defrost side blowout position 1c is selected, when the air control door 1 is driven by the motor 3 to the selected position, the contact 5b or 5c opens and the motor 3 stops. There is.

However, in the conventional example shown in FIG. 3 above,
External terminals are required to connect the motor drive circuit 2, the power supply 6, the NPN transistor 7, and the switches 8a, 8b, and 8c, and the number of external terminals is large, resulting in a large number of connection cords.
There are problems in that wiring work is complicated and costs increase.

Further, as another conventional example, there is one shown in FIG. 4, for example. In this conventional example, in the motor drive circuit shown in FIG. 3, the NPN transistor 7 is removed and connected to an external terminal, and the switches 8a, 8b, and 8c are respectively grounded. is the same as that shown in FIG. 3 above.

In the conventional example shown in FIG. 4, similar to the one in FIG.
A jumper wire 9 is required to connect the external terminal connected to d and the external terminal connected to the ground side terminal of the motor 3, resulting in an increase in cost.

(Purpose of the invention) The present invention was created by focusing on these conventional problems, and it is possible to reduce the number of external terminals and the number of connection cords, thereby reducing costs. The object of the present invention is to provide a motor drive circuit for an air control door for an air conditioner.

(Structure of the invention) The gist of the invention to achieve this purpose is as follows:
A motor for driving an air control door that can be switched to a plurality of positions, and a plurality of contacts corresponding to each of the plurality of positions, and opening any one of the plurality of contacts in conjunction with the motor. A motor drive circuit for an air control door for an air conditioner, comprising a switch mechanism for stopping the motor by connecting a common terminal of the switch mechanism and a ground terminal of the motor. The motor drive circuit of the air control door.

(Function) In the motor drive circuit of the air control door for an air conditioner, by connecting the common terminal of the switch mechanism and the ground terminal of the motor, the common terminal can be connected to the motor with or without a transistor. There is no need for an external terminal or its connection cord to connect to the ground side terminal of the device.

(Example) Hereinafter, each example of the present invention will be described based on the drawings. In the description of each embodiment, the same reference numerals are given to the same parts as in the above-mentioned conventional example, and redundant description will be omitted.

FIG. 1 is a schematic diagram showing a motor drive circuit for an air control door for an air conditioner according to a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an air control door for controlling the air blowing direction in an automobile air conditioner. It can be switched to three positions: a blowout position (second position) 1b and a defrost side blowout position (third position) 1c.

A motor drive circuit 2 for driving the air control door 1
is composed of a motor 3 that drives the air control door 1 and a switch mechanism 5.

The switch mechanism 5 is located at the three positions 1a, 1
It is composed of three contacts 5a, 5b, 5c arranged in a positional relationship corresponding to each of the contacts 5a, 1c, and a rotary plate 4 that rotates in conjunction with a motor 3 and has a notch 4a. are the three contacts 5a, 5
When the contact point matches either b or 5c, the contact is opened and the motor 3 is stopped. The rotary plate 4 is connected to the motor 3 via a speed reduction mechanism (not shown).

The power supply terminal 3a of the motor 3 is connected to the collector of a PNP transistor 10 via an external terminal, and the emitter of the PNP transistor 10 is connected to the power supply 6. PNP type transistor 10
A resistor 11 is interposed between the emitter and the base. A ground terminal 3b of the motor 3 is connected to a common terminal 5d of the switch mechanism 5 and is grounded via an external terminal.

The three contacts 5a, 5b, 5c are connected to the base of a PNP transistor 10 via external terminals, switches 8a, 8b, 8c, and a resistor 12, respectively.

The switches 8a, 8b, and 8c are respectively controlled by a control section (not shown) in accordance with the selection operation of the switching position of the air control door 1. When the first position 1a is selected, the switch 8a is switched to the second position.
When position 1b is selected, switch 8b is
When the position 1c is selected, the switches 8c are respectively closed.

The operation of the motor drive circuit for the air control door for an air conditioner having the above configuration will be explained below.

First, when the first position 1a of the air control door 1 is selected, the switch 8a is closed and the base of the PNP transistor 10 is connected to the resistor 12, the switch 8a, the external terminal, the contact 5a, the rotating plate 4, the common terminal 5d and the external Connected to the ground side through the terminal,
Since the base potential of the PNP transistor 10 decreases, the PNP transistor 10 turns on.
This causes current to flow through the motor 3, causing the motor 3 to rotate, thereby driving the air control door 1 towards the first position 1a and rotating the rotary plate 4. When the air control door 1 is driven to the first position 1a, the notch 4a of the rotary plate 4 matches the contact 5a, the contact 5a opens, and the PNP transistor 1
0 becomes high, the PNP type transistor 10 is turned off, and the motor 3 is stopped.

If the second position 1b of the air control door 1 is selected, when the air control door 1 is driven by the motor 3 to the second position 1b, the notch 4a and the contact 5
b match, the contact 5b opens, and the motor 3 stops.

Similarly, if the third position 1c of the air control door 1 is selected, the air control door 1 is moved to the third position 1c.
When driven by the motor 3 until the notch 4a
and the contact 5c match, the contact 5c opens, and the motor 3 stops.

In the first embodiment, the motor drive circuit 2 has five external terminals.

Next, a second embodiment of the present invention will be described based on FIG.

In the motor drive circuit of the air control door for an air conditioner shown in FIG. 2, the power supply side terminal 3a of the motor 3 is
is connected to the power source 6 via an external terminal, and the switches 8a, 8b, and 8c are each grounded. By grounding the switches 8a, 8b, and 8c, the external terminal for grounding the earth terminal 3b of the motor 3 is no longer necessary. The other configurations are the same as those of the first embodiment.

In this second embodiment, when the first position 1a of the air control door 1 is selected, the switch 8a is closed and the ground side terminal 3b of the motor 3 is connected to the common terminal 5d, the rotating plate 4, the contact 5a, the external terminal and the switch. It is grounded via 8a. This causes current to flow through the motor 3, causing the motor 3 to rotate, thereby driving the air control door 1 towards the first position 1a and rotating the rotary plate 4. The air control door 1 is the first
When driven to position 1a, cutout 4 of rotary plate 4
a matches the contact point 5a, the contact point 5a opens, and the connection between the ground side terminal 3b of the motor 3 and the ground is severed, and the motor 3 stops.

Second position 1b or third position 1 of air control door 1
The same operation occurs when c is selected.

In the second embodiment, the motor drive circuit 2 has four external terminals, and
The number of external terminals is one more than in the first embodiment.
There is only one less.

(Effect of the invention) According to the motor drive circuit for an air control door for an air conditioner according to the invention, the common terminal of the switch mechanism and the ground side terminal of the motor are connected, so that the common terminal is connected through a transistor or This eliminates the need for external terminals and their connection cords to connect to the ground side terminal of the motor, which reduces the number of external terminals and connection cords, thereby reducing the occurrence of shorts due to poor cord connections. This also simplifies the wiring work and reduces costs.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a motor drive circuit for an air control door for an air conditioner according to the first embodiment of the present invention, and FIG. 2 is a circuit diagram showing a motor drive circuit for an air control door for an air conditioner according to the first embodiment of the present invention. FIG. 3 is a circuit diagram of a motor drive circuit showing a conventional example, and FIG. 4 is a circuit diagram of a motor drive circuit showing another conventional example. 1... Air control door, 3... Motor, 3b...
Earth side terminal, 5...Switch mechanism, 5a, 5
b, 5c...Contact, 5d...Common terminal.

Claims (1)

[Scope of utility model registration request] A motor for driving an air control door that can be switched to a plurality of positions, and a plurality of contacts corresponding to each of the plurality of positions, and opening any one of the plurality of contacts in conjunction with the motor. A motor drive circuit for an air control door for an air conditioner, comprising a switch mechanism for stopping the motor by connecting a common terminal of the switch mechanism and a ground terminal of the motor. Air control door motor drive circuit.