JPH0321190Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is mainly used to control the rotation of a motor in a motor actuator used to move the air mix door, inside/outside air switching door, and other doors of automotive air conditioners. This relates to a gear shaft of a motor actuator, which serves as a rotating shaft of a reduction gear that decelerates and transmits data.

[Prior Art] In general, a motor actuator has a reduction gear that decelerates and transmits the rotation of the motor, which is housed inside a case that is divided into an upper and lower part. It is made of synthetic resin because of the need to do so.

The gear shaft of the conventional motor actuator has a reduction gear 4, for example, as shown in FIG.
A through hole 42 is bored in the center of 1, and the through hole 42
Shafts 43 and 44 that are inserted into and loosely fit are protruded from the upper and lower cases 45 and 46, respectively, or as shown in FIG. 5, the reduction gear 51
It is known that a single independent shaft 53 that fits loosely is inserted into a through hole drilled in the center of the case, and both ends of the shaft 53 are brought into contact with upper and lower cases 55 and 56, respectively. ing.

[Problems to be Solved by the Invention] Among the gear shafts of the conventional motor actuator described above, the gear shaft shown in FIG. When , the cases 45 and 46 are deformed and the reduction gear 4
1 is pinched from above and below, resulting in resistance to operation, and in some cases, the reduction gear 41 stops rotating at all.

In addition, in the case of the one in FIG. 5, the reduction gear 51
Since one shaft body 53 is required for each gear, the cost of parts increases, and as the number of gears increases, the increase in cost becomes extremely large.

The object of this invention is to eliminate such conventional drawbacks, provide a gear shaft for a motor actuator that operates reliably even when an external force is applied, and is inexpensive to manufacture.

[Means for Solving the Problems] To solve the above problems, the gear shaft of the motor actuator according to the present invention will be explained based on FIG. 1 corresponding to the embodiment. The reduction gear 7 that transmits the
Synthetic resin cases 1b and 1a divided into upper and lower parts
A through hole 7c is formed in the center of the reduction gear 7, and a shaft body is inserted into the through hole 7c from both directions, facing each other, and loosely fits into the through hole 7C. The shaft bodies 10 and 9 are integrally molded and project from the upper and lower cases 1b and 1a, respectively, and the shaft bodies 10 and 9 are in contact with each other in the axial direction.

[Function] The shaft bodies 10 and 9 that pivotally support the reduction gear 7 are in the case 1.
Since it is integrally molded and protrudes from b and 1a,
The shaft body is molded simultaneously when the cases 1b and 1a are molded.

Since the shaft bodies 10 and 9 are in contact with each other in the axial direction, the case does not deform even when an external force that presses the case from above and below is applied as shown by arrow C in Fig. 1, and the reduction gear 7 moves smoothly. Clearance H for rotation is always ensured.

[Embodiment] An embodiment of the present invention will be described based on FIGS. 1 to 3.

Fig. 3 is an exploded perspective view of the motor actuator, Fig. 1 is a cross-sectional view of the vicinity of its gear shaft, and Fig. 2 is an exploded perspective view of the motor actuator.
The figure is a sectional view of the vicinity of the coupler.

Reference numeral 1 denotes a case body for enclosing the device, and the case body 1 is made of electrically insulating synthetic resin such as polyethylene resin by injection molding or the like, and includes a lower case 1a and an upper case 1.
It is composed of b. A motor 2 is fixed within the lower case 1a with, for example, screws (not shown), and a worm gear 3 is attached to its output shaft.

A hole 4 is drilled near the center of the upper case 1b, and the shaft 5a of the main gear 5 projects upward through the hole 4, and its head is press-fit connected to an arm 6 connected to an actuated body. has been done.

Reference numeral 7 denotes a reduction gear that is inserted between the worm gear 3 and the main gear 5, and decelerates the rotation of the motor 2 and transmits it to the main gear 5. In this embodiment, the reduction gear 7 is There are three interlocking pieces.

On the bottom surface of the lower case 1a, the bearing 8 of the main gear is located near the center, and the reduction gear 7 is located on the side.
A shaft body 9 that rotatably supports the shaft is integrally molded and stands upright. In addition, in the upper case 1b,
A shaft 10 is integrally molded and protrudes downward at a position facing the shaft 9, and rotatably supports the reduction gear 7 from above. FIG. 1 is a sectional view showing the structure of this part in detail.

That is, each of the reduction gears 7 consists of a large gear 7a and a small gear 7b that are coaxially integrally formed, and a through hole 7C is bored in the center thereof. On the other hand, the shaft bodies 10 and 9, which are integrally formed and protruded from the upper and lower cases 1b and 1a, are inserted into the through hole 7c of the reduction gear so as to face each other from both the upper and lower directions.
Fitting parts 10a, 9a that fit loosely into the fitting parts 10a, 9a, and receiving parts 10b, 9 formed with a large diameter at their bases.
A concave portion 10c and a convex portion 9c that fit into each other are formed at the ends of the fitting portions 10a and 9a to prevent mutual misalignment.

The shaft body 1 protrudes from above and below.
0 and 9 are in contact with each other in the axial direction at the contact portion located in the through hole 7c of the reduction gear, and even when an external force that presses the case body 1 from above and below is applied as shown by arrow C in FIG. , receiving parts 10b, 9b
The clearance H between the two does not change. Therefore, H>h (h is the length of the reduction gear 7) is always ensured, and the reduction gear 7 can rotate smoothly even when an external force is applied.

Note that the abutment part does not necessarily need to be provided at the part B in FIG. 1, and may be provided at the top of the convex part (D in FIG.
It is sufficient that the shaft bodies 10 and 9 are in contact with each other in the axial direction so that the clearance H between b and 9b is not compressed.

Reference numeral 11 denotes a printed circuit board made of an electrically insulating material such as Bakelite, and the printed circuit board 11
A hole 12 through which the bearing 8 of the main gear 5 passes is bored near the center. A hole 13 is bored in one end of the printed circuit board 11, and the shaft 9 passes through the hole 13.

For example, a potentiometer 16 is provided on the lower surface of the main gear 5 as a rotation angle detection means for detecting the rotation angle of the main gear 5. The potentiometer 16 includes a plurality of contact pieces 16a including a resistor etc. formed concentrically around a hole 12 facing the lower surface of the main gear 5, and a plurality of contact pieces 16a provided on the lower surface of the main gear 5 and connected to the main gear 5. It consists of a contact that rotates together with the contact piece 5 and comes into contact with the contact piece 16a, and the contact is not shown.

On the other end side of the printed circuit board 11, connection pins 14a, which are electrical connection terminals, are planted in a row, for example, five in number. It is fixed by caulking and electrically connected to the printed wiring 18 connected to each contact piece 16a on the upper surface of the printed circuit board 11 by soldering.

A frame-shaped coupler frame 14b that opens upward is integrally molded on the upper surface of the upper case 1b at a position surrounding the connection pin 14a, and the connection pins 14a are arranged in the coupler frame 14b. These connecting pins 14a and coupler frame 1
4b forms a coupler 14.

Further, small protrusions 19 are formed at appropriate locations on the outer surface of the lower case 1a, and corresponding engagement pieces 20 are provided downwardly protruding from the outer surface of the upper case 1b, so that the protrusions 19 on the lower case are engaged. The upper and lower cases 1b and 1a are integrally connected by engaging the hole 20a at the center of the coupling piece 20. Reference numeral 21 denotes a lug for fixing the actuator to the body of an automobile, an air conditioning unit, etc. with screws.

The motor 2 is electrically connected to the wiring 18, but its illustration is omitted.

Since the embodiment of the present invention is configured as described above, by connecting a coupler of another device to the coupler 14 and inputting and outputting power and signals, it is possible to input and output the rotation angle detection signal from the potentiometer 16. Based on this, the rotation of the motor 2 is controlled, and the motor 2
The rotation of the arm 6 is reduced by the reduction gear 7, and the arm 6 rotates via the main gear 5, thereby moving an actuated object such as an air mix door to an appropriate position.

[Effects of the invention] According to the gear shaft of the motor actuator of the invention, the upper and lower shaft bodies are in contact with each other in the axial direction, so clearance is secured even when an external force that compresses the case is applied. , the reduction gear always operates reliably, and since the shaft is integrally molded and protrudes from the case, there is no need to manufacture the shaft itself separately, reducing parts costs and increasing the number of reduction gears. Indeed, it has the effect of greatly reducing costs.

In addition, since the shaft bodies protrude from both the upper and lower cases, there is no need for one shaft body to become extremely long, and therefore the case and shaft bodies can be integrated using synthetic resin. It is easy to mold and has excellent durability during use.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the vicinity of the gear shaft of an embodiment of the present invention, Fig. 2 is a cross-sectional view of the vicinity of the coupler, and Fig. 3 is an exploded perspective view of a motor actuator in which the embodiment is adopted. , 4 and 5 are sectional views of a gear shaft of a conventional motor actuator. 1...Case body, 1a...Lower case, 1b...
...Upper case, 2...Motor, 7...Reduction gear, 7
c...Through hole, 9...Shaft body, 9a...Fitting part, 1
0... Shaft body, 10a... Fitting part.

Claims (1)

[Scope of claim for utility model registration] 1. A reduction gear that reduces and transmits the rotation of a motor,
In the motor actuator, which is housed in a synthetic resin case divided into upper and lower parts, a through hole is drilled in the center of the reduction gear, and the gear is inserted into the through hole from both the upper and lower directions, facing each other. A gear shaft for a motor actuator, characterized in that a shaft body that loosely fits into the through hole is integrally molded and protrudes from each of the upper and lower cases so that the shaft bodies come into contact with each other in the axial direction. 2. A gear shaft for a motor actuator according to claim 1, wherein the upper and lower shaft bodies are formed with a concave portion and a convex portion that fit into each other.