JP2004266946A - Motor actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized motor actuator capable of reducing total cost. <P>SOLUTION: A printed circuit board 3 integrally formed with a connector housing 4 is mounted on a feeder terminal 8 of a DC motor 7. The printed circuit board 3 is mounted with an integrated circuit 6 for controlling driving of the DC motor 7, and is integrally with a principal part assembly 1 embedded with a conductive piece 2 integrally constituting a connector terminal 5. By assembling the principal part assembly 1 into a gear box, the motor actuator can be constituted of the wholly compact structure at a low cost. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor actuator, and more particularly, to a motor actuator that controls opening and closing of a door such as an air mix door provided in an air conditioner for a vehicle.
[0002]
[Prior art]
2. Description of the Related Art A motor actuator that controls the opening and closing of a door of a vehicle air conditioner generally includes a motor, a gear box, and a sensor that detects a rotational position of an output shaft. As a sensor, a potentiometer that detects the rotational position of the output shaft based on a resistance ratio that changes when a slider provided on the output shaft of the motor actuator slides on a resistive film is known. In addition to the above, a switch pattern detects which position of the output shaft is in a rotation range (for example, see Patent Document 1), or a rotary encoder that directly detects the rotation position of the output shaft (for example, Patent Document 2). Cf.) is known.
[0003]
Such a sensor stops the output shaft at a target rotation position by feeding back the detected rotation position of the output shaft to the control device. Therefore, the motor actuator needs at least two power supply terminals for supplying power to the motor and at least two to three output terminals for feeding back a detection signal of the sensor to the control device. An automotive air conditioner is provided with many doors, each with a motor actuator. For this reason, when the number of doors increases, the number of harnesses for individually wiring the motor actuator and the control device for the motor actuator also increases.
[0004]
Therefore, by performing open loop control using a stepping motor as the motor, the number of harnesses can be reduced. However, while a stepping motor can control the rotational position with high precision, the driving torque is smaller than that of a DC motor, so a large stepping motor must be used, and therefore, downsizing and low cost are required. It is not suitable for motor actuators for automobiles.
[0005]
In order to reduce the number of harnesses, it is effective to connect the control device and a plurality of motor actuators via a LAN (Local Area Network) (for example, see Patent Document 3). In the case where a LAN is provided between the control device and the motor actuator, the number of harnesses does not increase due to the increase in the number of motor actuators, so that the wiring of the harness can be simplified.
[0006]
[Patent Document 1]
Japanese Patent No. 2842907 (FIG. 1)
[Patent Document 2]
JP 2001-95292 A (paragraph number [0002], FIG. 3)
[Patent Document 3]
JP-A-10-230736 (paragraph numbers [0026] to [0027], FIG. 3)
[0007]
[Problems to be solved by the invention]
However, in any of the conventional motor actuators, components such as a sensor for detecting a rotational position, a control circuit, a motor, a motor drive circuit, and a connector are separately configured and configured by combining them. There is a problem that miniaturization and cost reduction are limited.
[0008]
The present invention has been made in view of such a point, and an object of the present invention is to provide a small-sized motor actuator with reduced total cost.
[0009]
[Means for Solving the Problems]
In the present invention, in order to solve the above-mentioned problem, in a motor actuator in which an output shaft is rotated to a target stop position given from the outside, a DC motor, and internal electric wiring and connector terminals are configured to constitute the DC motor. A conductive piece to which a power supply terminal is directly connected; an integrated circuit mounted on the conductive piece to control and drive the DC motor; and a wiring board in which the conductive piece is inserted and a connector housing is integrally formed by insert molding. , And a motor actuator characterized by comprising an assembly integrating the same.
[0010]
According to such a motor actuator, a wiring board in which a connector housing is integrally formed is attached to a power supply terminal of the DC motor, and an integrated circuit for controlling and driving the DC motor is mounted on the wiring board, and the connector terminal is mounted on the wiring board. By integrally configuring the assembly in which the conductive pieces are integrally formed, a compact and low-cost motor actuator can be configured as a whole.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing a main part assembly of a motor actuator according to the present invention, FIG. 2 is an exploded partial sectional view showing the main part assembly, and FIG. 3 is a view showing a conductive plate.
[0012]
As shown in FIG. 1, a main part assembly 1 of the motor actuator has a wiring board 3 formed by insert molding with a conductive piece 2 inserted therein. In the wiring board 3, a connector housing 4 is integrally formed, a part of the conductive piece 2 extends to the connector housing 4, and their terminal portions constitute a connector terminal 5. The connector terminals 5 include a total of three terminals, two for power supply (Vcc, GND) and one for communication (COM). A part of the conductive piece 2 is exposed, and an integrated circuit 6 for controlling and driving the motor actuator is mounted thereon.
[0013]
The integrated circuit 6 integrates a transceiver circuit that communicates with a master machine via a communication line, a motor driver circuit, a position detection circuit of an output shaft, and a control circuit that controls rotation of the output shaft to a target stop position. In preparation. Since the transceiver circuit is provided, a plurality of motor actuators can be connected to each other with three harnesses to form a LAN. A position detection circuit for an output shaft is built in the integrated circuit 6 for detecting a position of a rotary encoder or the like. Since this sensor is unnecessary, the main assembly 1 can be downsized.
[0014]
As shown in FIG. 2, a DC motor 7 is arranged on the back surface of the wiring board 3, and a power supply terminal 8 of the DC motor 7 is soldered to a land 9 of the conductive piece 2 to form the main assembly 1. I have. The conductive piece 2 is externally soldered with a resistor 10 and a capacitor 11 of a differentiating circuit which is a part of a position detecting circuit in the integrated circuit 6. The resistance 10 and the capacitor 11 detect a change in the current flowing through the DC motor 7 and supply the change to a position detection circuit in the integrated circuit 6. The change in the current flowing in the DC motor 7 is a pulse generated when the DC motor 7 ends the commutation or commutation by the brush and the commutator. In the case of a three-phase DC motor, six pulses are generated per motor rotation. are doing. The pulse is detected by a differentiating circuit including a resistor 10 and a capacitor 11, and a position detecting circuit in the integrated circuit 6 calculates the rotational position of the output shaft of the motor actuator by counting the number of pulses. By externally connecting the resistor 10 and the capacitor 11 of the differentiating circuit, it becomes possible to easily change the differential constant according to the characteristics of the DC motor 7 and the like. This makes it possible to provide a highly versatile actuator that can be easily applied to any door drive actuator used in automotive air conditioners.
[0015]
The conductive piece 2 has the form of a conductive plate 12 at the time of insert molding of the wiring board 3, as shown in FIG. The conductive plate 12 is formed by stamping a single metal plate into a wiring pattern by pressing. As the metal plate, for example, a brass plate is used. At this time, the conductive plate 12 is formed in a state where all the conductive pieces 2 are connected to each other by the connecting portions 13 marked with circles in the figure, so that the individual conductive pieces 2 do not fall apart during insert molding. I have to.
[0016]
Thereafter, the conductive plate 12 is bent at a right angle in a position 14 corresponding to the base of the connector terminal 5. This processing is performed as necessary in accordance with the insertion direction of the connector. When the connector terminal 5 is arranged on the same plane as the conductive plate, this bending processing is unnecessary.
[0017]
After the insert molding of the wiring board 3, the conductive plate 12 is separated into conductive pieces 2 that are electrically independent from each other by cutting off the connecting portions 13 marked with circles in the figure by pressing.
[0018]
4A and 4B are diagrams illustrating a first example of mounting the integrated circuit, in which FIG. 4A is a cross-sectional view as viewed through a power supply terminal of a DC motor, and FIG. 4B is a cross-sectional view as viewed through a connector housing. It is. 5A and 5B are diagrams showing a second example of mounting the integrated circuit, in which FIG. 5A is a cross-sectional view as seen through a power supply terminal of a DC motor, and FIG. 5B is a cross-sectional view as seen through a connector housing. It is. 6A and 6B are diagrams illustrating a third example of mounting the integrated circuit, in which FIG. 6A is a cross-sectional view as viewed through a power supply terminal of a DC motor, and FIG. 6B is a cross-sectional view as viewed through a connector housing. It is.
[0019]
As a method for mounting the integrated circuit 6 on the conductive piece 2, there is a surface mounting method shown in FIG. In this surface mounting method, the integrated circuit 6 has a surface mounting type package outer shape, and a lead coming out of the package is soldered to the surface of the conductive piece 2 without using a through hole. After mounting the integrated circuit 6 on the surface of the conductive piece 2, the integrated circuit 6 may be covered with the resin 15.
[0020]
As another mounting method of the integrated circuit 6 on the conductive piece 2, there is a method by wire bonding shown in FIG. The integrated circuit 6 uses a bare chip that is not molded with resin, connects the bonding pads on the chip with the conductive pieces 2 with wires, and seals the chip surface with resin 15.
[0021]
As still another mounting method of the integrated circuit 6 on the conductive piece 2, there is a flip chip mounting method shown in FIG. The integrated circuit 6 uses a semiconductor chip provided with solder bumps as terminals on the lower surface, is connected to the conductive piece 2 via the solder bumps, and seals the chip surface with a resin 15.
[0022]
FIG. 7 is an exploded view showing the motor actuator. In addition, in this figure, in order to avoid complicating the figure, the main part assembly 1 omits the wiring board 3 and shows only the DC motor 7.
[0023]
The motor actuator is configured by incorporating the main assembly 1 into a gear box. The gear box has a resin-molded outer case 16 and a lid 17, in which three intermediate gears 18, 19, and 20, and an output gear 21 are housed. And a lever 23 which is connected to the output shaft 22 of the output gear 21 and swings. The outer case 16 includes a shaft 24 for rotatably supporting the intermediate gears 18, 19, 20; a shaft hole (not shown) for rotatably supporting the output gear 21; and a housing for housing the main assembly 1 and the like. Have been.
[0024]
When the main assembly 1, the intermediate gears 18, 19, and 20 and the output gear 21 are accommodated in the gear box, the worm gear 25 (see FIG. 2) attached to the output shaft of the DC motor 7 is connected to the first intermediate gear 18. The first intermediate gear 18 is disposed so as to mesh with the large-diameter output gear 21 via the second intermediate gear 19 and the third intermediate gear 20. An end of an output shaft formed integrally with the output gear 21 is attached so that the lever 23 rotates integrally.
[0025]
FIG. 8 is a side view showing the appearance of the motor actuator, and FIG. 9 is a plan view showing the appearance of the motor actuator.
A motor in which a connector housing 4 formed integrally with the wiring board 3 of the main assembly 1 projects outside the outer case 16 and the lid 17 by incorporating the main assembly 1 into the gear box. An actuator is configured.
[0026]
【The invention's effect】
As described above, according to the present invention, a wiring board in which a connector housing is integrally formed is attached to a power supply terminal of a DC motor, and an integrated circuit for controlling and driving the DC motor is mounted on the wiring board. An assembly in which a conductive piece that integrally forms a terminal is embedded was integrally formed. Thereby, a compact and low-cost motor actuator can be configured as a whole.
[Brief description of the drawings]
FIG. 1 is a view showing a main part assembly of a motor actuator according to the present invention.
FIG. 2 is an exploded partial sectional view showing a main part assembly.
FIG. 3 is a view showing a conductive plate.
4A and 4B are diagrams showing a first mounting example of an integrated circuit, in which FIG. 4A is a cross-sectional view as viewed through a power supply terminal of a DC motor, and FIG. 4B is a cross-sectional view as viewed through a connector housing. FIG.
5A and 5B are diagrams illustrating a second example of mounting the integrated circuit, in which FIG. 5A is a cross-sectional view as viewed through a power supply terminal of a DC motor, and FIG. 5B is a cross-sectional view as viewed through a connector housing. FIG.
6A and 6B are diagrams illustrating a third example of mounting the integrated circuit, in which FIG. 6A is a cross-sectional view as viewed through a power supply terminal of the DC motor, and FIG. 6B is a cross-sectional view as viewed through a connector housing. FIG.
FIG. 7 is an exploded view showing a motor actuator.
FIG. 8 is a side view showing the appearance of the motor actuator.
FIG. 9 is a plan view showing the appearance of the motor actuator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Principal part assembly 2 Conductive piece 3 Wiring board 4 Connector housing 5 Connector terminal 6 Integrated circuit 7 DC motor 8 Power supply terminal 9 Land 10 Resistance 11 Capacitor 12 Conductive plate 13 Connecting part 14 Bending position 15 Resin 16 Exterior case 17 Cover 18, 19, 20 Intermediate gear 21 Output gear 22 Output shaft 23 Lever 24 Shaft 25 Worm gear

Claims (11)

In a motor actuator whose output shaft is rotated to a target stop position given from the outside,
A DC motor,
A conductive piece that constitutes an internal electrical wiring and connector terminal and is directly connected to a power supply terminal of the DC motor;
An integrated circuit mounted on the conductive piece to control and drive the DC motor;
A wiring board in which the connector housing is integrally formed by insert molding by inserting the conductive piece,
A motor actuator, comprising: an assembly configured integrally with the motor actuator. The motor actuator according to claim 1, wherein the assembly is mounted on a gear box. 2. The motor actuator according to claim 1, wherein the connector terminal is configured by extending the conductive piece into the connector housing of the wiring board. 3. 2. The motor actuator according to claim 1, wherein the connector terminal includes terminals of two power lines and one communication line. The said conductive piece is comprised by cutting off the said connection part after insert-molding the said wiring board with the conductive plate formed in the state which all the said conductive pieces were connected mutually by the connection part. Item 2. The motor actuator according to Item 1. 2. The assembly according to claim 1, wherein a resistor and a capacitor constituting a differentiating circuit for detecting a change in a current flowing through the DC motor are mounted on the conductive piece outside the integrated circuit. Motor actuator. 7. The motor actuator according to claim 6, wherein the integrated circuit includes a position detecting circuit that calculates a rotational position of the output shaft based on a differential signal obtained from the differentiating circuit. The integrated circuit includes a transceiver circuit that communicates with a master device via a communication line, a motor driver circuit that drives the DC motor, and the target while comparing the position of the output shaft obtained by the position detection circuit. The motor actuator according to claim 7, further comprising a control circuit configured to control the rotation of the DC motor to a stop position. The motor actuator according to claim 1, wherein the integrated circuit is surface-mounted on the conductive piece. The motor actuator according to claim 1, wherein the integrated circuit is wired to the conductive piece by wire bonding. The motor actuator according to claim 1, wherein the integrated circuit is flip-chip mounted on the conductive piece.

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