JP2007092911A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket withstanding high surface pressure, having low reaction force and the rigidity required by a seal lip 5 and capable of preventing its deformation and falling down. <P>SOLUTION: In this gasket 1 constituted by forming a flange part 3 having larger width than that of a basic part 2 integrally at a tip of the basic part 2 fitted into a mounting channel of a housing and providing the seal lip 5 having substantially triangular cross section on a sealing face 4 of the flange part 3, height h of the seal lip 5, an apex angle θ of the seal lip 5, and curvature R of vertex of the seal lip 5 are set to 0.5 to 0.7 mm, 45 to 75 degrees, and 0.1 to 0.3 mm, respectively. Consequently, high surface pressure, low reaction force, and high rigidity are simultaneously realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gasket that is a kind of sealing device, and more particularly to a gasket that can simultaneously realize high surface pressure and low reaction force in a flange portion that is in close contact with a mating member. The gasket of the present invention is used, for example, in the field of automobiles or their accessories, the field of general industrial machinery, the field of household electrical equipment, and the like.

  Conventionally, as shown in FIG. 2, a flange portion (seal portion) 53 wider than the base portion 52 is integrally formed at the tip of the base portion 52 fitted in the mounting groove 22 of the housing 21 to have a substantially T-shaped cross section. In addition, there is known a cylinder head cover gasket 51 in which a seal lip (protrusion) 55 having a substantially triangular cross section is provided at the center of the seal surface 54 of the flange portion 53 (see Patent Document 1).

  On the other hand, cylinder head covers (cam covers), intake manifolds, etc. have been made of resin in recent years, and if rubber-made elastic gaskets are attached to these resin housings, they are deformed into resin housings due to the reaction force generated by the compression of the gaskets. As a result, there is a problem that a predetermined surface pressure cannot be generated on the seal surface, and a leak occurs due to a decrease in the surface pressure. In order to avoid this problem, a high surface pressure is obtained and a low resistance is obtained. Power gaskets are required.

  However, in the gasket 51 of FIG. 2 described above, the seal lip 55 has a shape in which only sealability (= high surface pressure) is considered and low reaction force is not considered at all. Therefore, the gasket 51 having such a shape cannot meet the demand for the low reaction force.

  If a gasket having a high surface pressure and a low reaction force is desired, the width of the seal lip 55 may be narrowed and the height may be set high. Since the rigidity is lowered, the seal lip 55 is easily deformed or falls.

  Therefore, in practice, a gasket having a high surface pressure, a low reaction force, and a required rigidity cannot be established simply by forming the seal lip 55 into a substantially triangular cross section.

Japanese Patent Application Laid-Open No. 6-281913

  In view of the above points, the present invention is a gasket having a high surface pressure and a low reaction force, and having a seal lip having a required rigidity and does not deform or fall down. The purpose is to provide.

In order to achieve the above object, the gasket of the present invention is formed by integrally forming a flange portion wider than the base portion at the tip of the base portion to be fitted into the mounting groove of the housing, and has a substantially triangular cross section on the sealing surface of the flange portion. In a gasket provided with a seal lip exhibiting
The height h of the seal lip is 0.5 to 0.7 mm,
The apex angle θ of the seal lip is 45 to 75 degrees,
The curvature R of the apex of the seal lip is 0.1 to 0.3 mm
It is characterized by being set to.

  For gaskets that have the base and flange parts together and that have a sealing lip on the sealing surface of the flange, the characteristics of high surface pressure, low reaction force, and high rigidity can be obtained by precisely identifying the cross-sectional shape of the sealing lip. As described above, the seal lip height h is 0.5 to 0.7 mm, and the seal lip apex angle θ is 45 to 75 degrees. The curvature R of the apex of the seal lip is preferably set to 0.1 to 0.3 mm.

  These specification values are derived from the results of comparative tests and the like conducted by the inventors of the present invention. When the height h of the seal lip is less than 0.5 to 0.7 mm, the seal lip is There is a problem that the surface pressure to be formed is small and the reaction force exerted on the seal surface by the gasket is large. If the surface pressure exceeds 0.5 to 0.7 mm, the surface pressure formed by the seal lip is large, but the seal lip collapses. Since it is easy, there is a problem that the seal lip does not generate a predetermined surface pressure and the sealing performance is lowered.

  Also, when the apex angle θ of the seal lip is less than 45 to 75 degrees, the surface pressure formed by the seal lip is large, but the rigidity of the seal lip is lowered and the seal lip is liable to fall down. If it exceeds, the surface pressure formed by the seal lip is small, and the reaction force exerted on the seal surface by the gasket increases.

  Also, if the curvature R of the apex of the seal lip is less than 0.1 to 0.3 mm, it becomes difficult to release, so there is a problem that the moldability is not good, and if it exceeds 0.1 to 0.3 mm, Since the contact surface with the tip of the seal lip increases, there is a problem that the surface pressure formed by the seal lip decreases.

  As described above, by setting the seal lip height h, apex angle θ, and apex curvature R to optimize the cross-sectional shape of the seal lip, the gasket has high surface pressure, low reaction force and high rigidity. It becomes possible to have the characteristics at the same time. Therefore, as in the initial purpose of the present invention, it is possible to provide a gasket which can obtain a high surface pressure and has a low reaction force, and has a necessary rigidity for the seal lip, and does not deform or fall over. it can.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of a main part of a gasket 1 according to an embodiment of the present invention.

  The gasket 1 according to this embodiment is provided on one of two members (both not shown, for example, a cylinder head and a cylinder head cover) facing each other in a cylinder head cover (cam cover), an intake manifold, a throttle, or the like. The two members are sealed by being mounted in the mounting groove and in close contact with the other member, and are configured as follows.

  That is, the gasket 1 is formed in an endless shape by a predetermined rubber-like elastic body, and is formed in a planar layout along the peripheral plane shape of the cylinder head cover or the like (endless shape along the planar layout). To be molded).

  As shown in FIG. 1, the gasket 1 has a flange portion (also referred to as a seal portion, also referred to as a seal portion) wider than the base portion 2 (and the attachment groove) at the tip of a base portion 2 fitted into the attachment groove. Is not fitted in the mounting groove but is placed and clamped between the two members) to form a substantially T-shaped cross section, and a substantially triangular cross section at the center of the seal surface 4 of the flange portion 3 A seal lip (also referred to as a ridge) 5 having a shape is provided, and the cross-sectional shape thereof has dimensions as listed below.

The height h of the seal lip 5: 0.5 to 0.7 mm,
The apex angle θ of the seal lip 5 is 45 to 75 degrees,
Curvature radius R of seal lip 5: 0.1 to 0.3 mm

  According to the gasket 1 having the above structure, since it is possible to simultaneously have characteristics of high surface pressure, low reaction force, and high rigidity, a high surface pressure is obtained and the reaction force is low. 5 has the necessary rigidity and exhibits the characteristic that it does not deform or fall over.

Sectional drawing (end view) of the principal part of the gasket which concerns on the Example of this invention Sectional view (end view) of the main part of the gasket according to the conventional example

Explanation of symbols

1 Gasket 2 Base 3 Flange 4 Seal surface 5 Seal lip

Claims (1)

A flange portion (3) wider than the base portion (2) is integrally formed at the tip of the base portion (2) to be fitted in the mounting groove of the housing, and the cross section of the seal surface (4) of the flange portion (3) is substantially omitted. In the gasket (1) provided with the sealing lip (5) having a triangular shape,
The height h of the seal lip (5) is 0.5 to 0.7 mm,
The apex angle θ of the seal lip (5) is 45 to 75 degrees,
The curvature R of the apex of the seal lip (5) is 0.1 to 0.3 mm.
A gasket characterized by being set to.

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