JPH028556Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a stopper circuit that limits the drive of a motor actuator to a predetermined range, mainly in a motor actuator for driving an air mix door of an automobile air conditioner. be.

In FIG. 1, a well-known manner of use of a motor actuator 1 is shown, and the motor actuator 1
A motor 3 and a gear device (not shown) are housed in an actuator case 2, and are connected to an air mix door 8 via a link mechanism 7 consisting of levers 4, 5 and a connecting rod 6. Depending on the opening degree of the air mix door 8,
It adjusts the amount of air that has passed through the evaporator 10 in the air conditioning case 9 and is sent to the heater core 11, and the air mix door 8 is at the full cool position F,
C, the entire amount of air is in the heater core 1
1, and when the air mix door 8 is in the full heat position F, H, the entire amount of air is sent to the heater core 11. Therefore, it is sufficient for the motor actuator 1 to be driven in forward and reverse directions within a predetermined range corresponding to the opening range of the air mix door 8;
Since there is a risk that the air mix door 8 may get caught on the air conditioning case 9 and become stuck, a stopper circuit is provided in the motor actuator 1 to limit the drive of the motor actuator 1 within a predetermined range. This is known from Japanese Patent No. 57-146765, and a specific example thereof is shown in FIG.

In FIG. 2, the stopper circuit has movable contacts 14a to 14c arranged in a radial direction on the lower surface of an output gear 13 having an output shaft 12 to which the lever 4 is fitted, and rotates integrally with the output gear 13. It's becoming like that. Further, on the wiring board 15 disposed on the bottom surface of the actuator case 2, an arc-shaped common contact 16, a fixed contact 17a,
17b, the movable contact 14a slides on the common contact 16, and the movable contacts 14b, 14c slide on the fixed contacts 17a, 17b, respectively. The fixed contacts 17a, 17b form a prescribed angle α between one end of each, and when the movable contacts 14b, 14c are separated from one end of the fixed contacts 17a, 17b, the motor drive circuit is opened. , this restriction angle α corresponds to the opening degree of the air mix door 8.

However, in reality, play occurs in the link mechanism 7 due to lack of precision during assembly or due to long-term use, and even if the stopper circuit itself turns off accurately, the operating angle of the air mix door 8 is insufficient. The position indicated by the solid line in the figure is the limit on the full cool side, and even if commanded to be at full cool position F, C or full heat position F, H, a gap will occur between it and the air conditioning case 9, causing air leakage. There was a drawback.

Therefore, the object of this invention is to provide a stopper circuit for a motor actuator that can correctly regulate the opening degree of an air mix door and thereby prevent air leakage. In a stopper circuit of a motor actuator that opens a motor drive circuit when a sliding movable contact is separated from one end of the fixed contact, an insulating part that is not electrically conductive with the fixed contact is provided at one end of the fixed contact; The present invention is characterized in that conductive electrode portions are alternately provided on the locus of the movable contact.

Therefore, when the movable contact leaves the fixed contact and enters the insulating part, the motor drive circuit is opened and the motor is temporarily stopped. However, the overrun with respect to the load is inversely proportional as shown in Figure 3, so if the air mix door has not yet reached the full cool position or the full heat position when entering the insulation section, the load is small. Overrun is large. Therefore, the movable contact contacts the electrode portion, the motor drive circuit is closed again, and the air mix door moves. These operations are repeated as necessary until the air mix door reaches the full cool position or the full heat position. As this increases the load, the amount of overrun becomes small and after that the motor drive circuit is opened and the drive of the motor actuator is stopped. Through these actions, the above problem can be achieved. be.

Examples of this invention will be described below with reference to the drawings.

In FIG. 4, a circuit example of a wiring board 15 having a stopper circuit according to the present invention is shown.
4a to 14c, common contact 16 and fixed contact 17
a, 17b.

The common contact 16 is connected to one terminal 1 of the connector 18.
9a, and fixed contacts 17a, 17b
As in the conventional example described above, each end constitutes a regulating angle α, and
It is connected to one end of a motor 21 via diodes 20a and 20b, and the other end of the motor 21 is connected to the other terminal 19b of the connector 18. Note that the common contact 16 and the corresponding movable contact 14a can be omitted by wiring directly from the terminal 19a of the connector 18 to the movable contacts 14b and 14c.

Then, the fixed contact 17 that constitutes the regulation angle α
A and 17b have a predetermined width a to one end at each end.
The insulating parts 22a to 22d having a width of
The contact points 16 are provided alternately on the locus up to both ends of the common contact point 16. The insulating parts 22a to 22d are connected to the wiring board 1.
5, and is not electrically connected to fixed contacts 17a and 17b. In addition, as another example,
The insulating parts 22a to 22d are connected to the fixed contacts 17a and 17b.
An insulator or fixed contact 17a having approximately the same thickness as
A conductor separate from 17b may be provided on the wiring board to prevent the surface of wiring board 15 from being scraped by sliding of movable contacts 14b and 14c.

On the other hand, the electrode parts 23a to 23c are electrically connected to the fixed contacts 17a and 17b via the connecting part 24.
Note that the electrode portions 23a to 23c are connected to the fixed contact 17.
Although they are tangentially connected via a connecting portion 24 that is integral with a and 17b, the connecting portion 24 may be replaced by a simple wiring.

In the above configuration, the terminal 19 of the connector 18
When voltage is applied to a and 19b, the movable contact 14
b, 14c are on the fixed contacts 17a, 17b, the stopper circuit, diodes 20a, 20b
A motor drive circuit including the motor 21 is established, and the motor 21 rotates in either forward or reverse direction. moreover,
When voltage is continued to be applied to the above-mentioned 19a and 19b, the movable contacts 14b and 14c finally reach the fixed contact 17.
a, 17b and enters the first insulating section 22a to open the motor drive circuit. At this time, the air mix door 8 shown in FIG.
C or the full heat position F, H, the load on the motor actuator 1 is small, resulting in a large overrun. Therefore, the movable contacts 14b, 14c also cross over the width a of the insulating part 22a and come into contact with the first electrode 23a, the motor drive circuit is closed again and the motor 21 is energized, and then the second insulating part 22a is immediately turned on. movable contact 14
a and 14b enter, and the motor drive circuit is opened.
Even at this stage, if the air mix door 8 does not reach the full cool position F, C or the full heat position F, H, it will overrun further and the second insulating part 2
2b, and the air mix door 8 moves to the full cool position F, C or the full heat position F,
Repeat the same operation until reaching H. When the air mix door 8 reaches the full cool position F, C or the full heat position F, H and hits the air conditioning case 9, the load increases and overrun decreases, causing the movable contacts 14b, 14c to
22d, and the motor 21 is no longer energized.

As described above, according to this invention, due to the relationship between load and overrun, the regulation of the drive of the motor actuator is released until the air mix door reaches the full cool position or the full heat position, so that the air Since leakage can be prevented, waste caused by air leakage can be eliminated and accurate air conditioning control can be achieved.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing how the motor actuator is used, Figure 2 is a perspective view showing the configuration of a conventional stopper circuit, and Figure 3 is a characteristic line showing the relationship between motor actuator load and overrun. 4 is a circuit diagram of a wiring board having a stopper circuit according to the invention, and FIG. 5 is an enlarged plan view showing the vicinity of one end of the fixed contact of the same. 14a to 14c...Movable contacts, 17a, 17b
... Fixed contact, 22a to 22d ... Insulation part, 23
a to 23c...electrode portions.

Claims (1)

[Scope of utility model registration request] In a stopper circuit for a motor actuator that opens a motor drive circuit when a movable contact that slides on a fixed contact is separated from one end of the fixed contact, an insulating part that is non-conductive with the fixed contact is provided at one end of the fixed contact; 1. A stopper circuit for a motor actuator, characterized in that electrode portions conducting with a fixed contact are provided alternately on the locus of the movable contact.