JPH0434274Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a seal structure for a cylindrical case used in a gear case, a motor case, etc.

[Prior art and problems to be solved by the invention] Generally, in this type of cylindrical case, for example, a power window gear case, as shown in FIG. A cover that accommodates a seal ring with a circular cross section made of material and covers the cylindrical case opening.
Airtightness within the case is ensured by assembling the case so that the inner circumferential surface of the flange portion formed at the periphery thereof comes into pressure contact with the seal ring. By the way, today,
In such a case, it has been proposed to make the case smaller by forming the bent (flange) part of the cover periphery in an inclined shape, as shown in FIG. Since the accommodation space becomes smaller, it becomes impossible to accommodate a seal ring having a sufficient cross-sectional area with excellent airtightness, and a new problem arises in that the airtightness deteriorates. In addition, when assembling the seal ring having a circular cross section into the concave groove of the cylindrical case,
It has the disadvantage of being easily twisted, and there are also problems with ease of assembly and stability of the seal.

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a sealing structure for a cylindrical case that can eliminate these drawbacks, and has at least the following: A groove for accommodating a seal ring is formed in the opening periphery of a cylindrical case with one cylindrical end open, while a slanted groove is formed so that the periphery of a cover that covers the case opening fits externally into the opening periphery. The groove is formed with an inner contact piece that comes into contact with the inner surface of the groove, an outer contact piece that elastically deforms along the inner surface of the flange due to the pressing force received from the flange, and a surface contact piece that is integrally formed in the groove. It is characterized by housing a seal ring formed by a connecting piece that is connected to the seal ring.

Further, the seal ring is characterized in that its cross section is approximately H-shaped or approximately N-shaped.

With this configuration, the present invention makes it possible to significantly improve airtightness and ease of assembling the seal ring.

[Example] Next, an example of the present invention will be described based on the drawings. In the drawings, reference numeral 1 denotes a gear case for a power window installed in an automobile door, and the gear case 1 includes a worm gear 3, which is fixed to the tip of a motor shaft 2a of a motor section 2, which is integrally provided.
A worm wheel 4 that meshes with the worm gear 3, an output shaft 5 that rotates integrally with the worm wheel 4, and the like are installed inside, but these structures are all conventional.

Reference numeral 6 denotes a bottomed cylindrical case that forms the outer shell of the gear case 1, and a groove (step) 6b for accommodating a seal ring 7, which will be described later, is formed on the outer peripheral side of the opening 6a of the case 6. has been done. on the other hand,
8 is a cover that covers the opening 6a of the case 6, and the peripheral edge of the cover 8 covers the opening 6a of the case 6.
It is formed in a flange portion 8a that is bent to fit externally on the side end, but the flange portion 8a widens at the end (45°).
As a result, the groove portion 6b of the case 6 substantially closes the inclined inner surface of the flange portion 8a to form a seal ring accommodating portion having a triangular cross section.

The seal ring 7 incorporated in the seal ring accommodating portion has an inner abutment piece 7a forming an inner peripheral surface of the seal ring 7 and an outer abutment piece 7b forming an outer peripheral surface, which are integrally connected by a connecting piece 7c. The inner abutting piece 7a is in contact with the circumferential surface of the groove 6b, and the outer abutting piece 7b is in contact with the circumferential surface of the groove 6b when it is assembled into the accommodating part.
is elastically deformed along the inclined inner circumferential surface of the flange portion 8a by the pressure received from the flange portion 8a, and comes into elastic contact therewith.

In the embodiment of the present invention configured as described above, when assembling the seal ring 7, since the inner circumferential surface (inner contact piece 7a) of the seal ring 7 is formed flat in the assembling direction, The seal ring 7 can be smoothly assembled into the groove 6b of the case 6 without twisting unlike a ring formed with a circular cross section, and the assembled seal ring 7 can be received from the flange 8a of the cover 8. Due to the pressure, the seal ring 7 is elastically deformed by the sealing distance A (shown in FIG. 3).
The inner circumferential surface (inner abutting piece 7a) of the flange 8a fully abuts the inner circumferential surface of the groove 6b, and the outer circumferential surface (outer abutting piece 7b) fully abuts the inclined inner circumferential surface of the flange 8a. Become.

As described above, in the present invention, the peripheral edge of the cover 8 is formed in an inclined shape in order to reduce the size of the gear case 1, and the seal ring housing has a substantially triangular cross section due to the formation of the inclined portion. The inner circumferential surface (inner abutment piece 7a) is in full contact with the circumferential surface in the groove 6b, and the outer circumferential surface (outer abutment piece 7b) is in full contact with the inclined inner circumferential surface of the flange part 8a. A seal ring 7 is housed therein. Therefore, the area of contact with the case 6 and the cover 8 can be significantly increased compared to a circle formed with the same cross-sectional area, and as a result, the airtightness of the gear case 1 can be significantly improved. can.

Moreover, since the inner circumferential surface (inner abutment piece 7a) of the seal ring 7 is formed flat in the assembly direction, the seal ring 7 can be assembled without twisting unlike the O-ring. Not only can it be smoothly assembled into the groove 6b of the case 6 and the ease of assembly can be improved, but the stability of the seal can also be improved.

Furthermore, in the case of the seal ring 7 of the present invention,
Since a large sealing allowance can be secured, the tolerance range for machining errors of the case 6 and cover 8 as well as assembly errors of the cover 8 can be greatly expanded, and as a result, seal failures due to the above errors can be reliably prevented. can do.

Further, since the seal ring 7 of this embodiment is formed to have an H-shaped cross section with no front or back, there is no risk of assembly errors during assembly, which is extremely convenient in terms of quality control.

It should be noted that the present invention is of course not limited to the above-mentioned embodiments; the point is that it may be formed from inner and outer abutting pieces and an abutting piece that connects them. For example, it may be formed to have an N-shaped cross section as shown in FIG.

[Operations and Effects] In summary, since the present invention is constructed as described above, the flange portion of the cover is formed in an inclined shape in order to achieve miniaturization, but the seal ring accommodated in the groove portion is It is formed of an inner abutting piece that comes into contact with the inner surface of the groove, an outer abutting piece that elastically deforms along the inner surface of the flange due to the pressing force received from the flange, and a connecting piece that connects the surface abutting pieces together. Therefore, the contact area can be made significantly larger than that of a seal ring with a circular cross-section formed to have the same cross-sectional area, and as a result, the airtightness of the case can be significantly improved. Moreover, since the inner abutment piece that forms the inner circumferential surface of the seal ring can be formed flat in the assembly direction, the seal ring can be assembled without twisting unlike a seal ring with a circular cross section. The seal ring can be smoothly assembled into the groove of the seal ring, thereby improving the ease of assembling the seal ring and the stability of the seal. Furthermore, with the seal ring of the present invention, a larger sealing allowance can be ensured compared to a seal ring with a circular cross section, so the tolerance range for machining errors of the case and cover, as well as errors in assembling the cover, can be greatly reduced. As a result, it is possible to reliably prevent seal failures caused by the above-mentioned errors.

[Brief explanation of the drawing]

The drawings show an embodiment of the sealing structure of the cylindrical case according to the present invention, in which Fig. 1 is a front view of the gear case, Fig. 2 is a vertical sectional view of the same, and Fig. 3 A and B are respectively 4A, B, and C are respectively a plan view of the seal ring, a partially cutaway front view, and an enlarged sectional view of the main part, and FIG. 5 is a sectional view of the main part showing another example. , FIG. 6 is a sectional view of the main part showing a conventional example, and FIG. 7 is a sectional view of the main part of the same. In the figure, 1 is a gear case, 6 is a case, 6b is a groove, 7 is a seal ring, 7a is an inner contact piece, 7b
is an outer contact piece, 7c is a connecting piece, 8 is a cover, 8a
is the flange part.

Claims (1)

[Claims for Utility Model Registration] 1. A groove for accommodating a seal ring is formed in the opening periphery of a cylindrical case in which at least one cylindrical end is open, while a periphery of a cover that covers the case opening is The groove is formed with an inclined flange that fits externally into the peripheral edge of the opening, and the groove includes an inner contact piece that comes into contact with the inner surface of the groove, and an outer side that elastically deforms along the inner surface of the flange due to the pressing force received from the flange. A seal structure for a cylindrical case, characterized by housing a seal ring formed by a contact piece and a connecting piece that integrally connects both the contact pieces. 2. The first aspect of the present invention is characterized in that the cross section of the seal ring is approximately H-shaped or approximately N-shaped.
A seal structure for a cylindrical case according to the claims.