JPH0718069U - Gasket with captive structure - Google Patents

Abstract

(57) [Summary] The present invention relates to an annular gasket made of an elastic body, which has a fall-out preventing structure to be mounted on a cylinder head cover and has improved insertion workability. A gasket with a dropout prevention structure provided with a dropout prevention projection is characterized in that the projection is shaped into a wedge shape having directionality in the annular direction of the gasket.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an annular gasket made of an elastic material such as synthetic rubber or synthetic resin, and more specifically, to a gasket having a fall-preventing structure mounted on an engine cylinder head cover.

[0002]

[Prior art]

 Conventionally, an engine cylinder head cover has an annular gasket inserted in an annular groove cut in the periphery thereof, and is attached to a cylinder block with a fastening member together with the cylinder head cover to seal the cylinder head. When assembling, set the cylinder head cover face down with the annular groove facing upward, press a gasket having a thickness almost the same as the annular groove into the annular groove, and then install the gasket. It is a commonly practiced mounting method to place the cylinder head cover on the cylinder head with the annular groove facing downward and to mount the cover by tightening.

In this mounting structure, when the gasket-attached annular groove is directed downward, the gasket is likely to fall out of the insertion groove or partly come off, and the gasket is not completely fitted in the annular groove. If it is tightened and fixed from the state, the sealing force will become slightly unstable. To avoid this situation, a structure in which a convex surface is provided on the side surface of a gasket has been developed as in Japanese Utility Model Publication No. 47-40192, and this is a general structure that prevents the gasket from falling off at present.

Further, at present, as shown in FIG. 6 based on such a convex surface structure, as shown in FIG. 6, a toothed engagement groove (6) is provided on the convex portion (5) in No. 62-75262. A seal rubber structure provided with is proposed. The structure of the convex portion (5) was developed for the purpose of securing the fixing and locking force without increasing the pressure-bonded mass by providing the locking groove (6).

[0005]

[Problems to be solved by the device]

 However, in the seal rubber structure in which the engaging groove (6) is provided in the convex portion (5), there remains a big problem that the mounting workability must be solved. That is, in order to press-fit a gasket having substantially the same thickness as the annular groove (2) into the annular groove (2) of the cover member (1) such as the cylinder head cover, the abruptly protruding convex portion (5) causes the insertion failure. It is obvious that it becomes a part, and it takes a lot of work unless the shape and mass are taken into consideration. From this point of view, looking at the structure of the locking groove (6) shown in FIG. 6, a plurality of locking grooves (6) are formed in a position parallel to the annular groove (2) of the cover member (1). This locking groove (6) is inserted as a large resistance material in the insertion direction, and since this resistance prevents the seal rubber from falling off, this resistance torque can be reduced. It has drawbacks that cannot be achieved. An object of the present invention is to provide a gasket with a fall-out prevention structure that eliminates such drawbacks, realizes excellent attachment workability and strong fixation, and also reduces the amount of partial compressive deformation.

[0006]

[Means for Solving the Problems]

 The present invention will be described with reference to the drawings. As shown in FIGS. 1, 2 and 3, a fitting to be inserted into an annular groove (2) of a cover member (1) such as an engine cylinder head cover or an oil pan. A gasket (4) with a fall prevention structure, which is provided with a protrusion (3) for fall prevention that partially protrudes from the peripheral surface, wherein the protrusion (3) is attached to a gasket (4) with a fall prevention structure. It is characterized by being shaped into a wedge shape (3a) having a direction in which the thickness gradually widens in the annular direction.

[0007]

[Action]

 The gasket (4) with a fall prevention structure of the present invention has the following excellent functions by the above structure. That is, in order to mount the gasket (4) in the annular groove (2) of the cover member (1), a part of an appropriate portion of the gasket is first mounted in the annular groove (2), and the insertion portion thereof is used as a starting point. Generally, the most efficient mounting method is to insert the entire gasket by pressing the parts that follow it along the line. In contrast to this mounting structure, in the present invention, as shown in FIG. 1, by forming a wedge shape (3a) that gradually becomes thicker in the annular direction of the gasket (4), as shown in FIG. As it is inserted into the annular groove (2) of the cover member (1) in order, the small wedge portion of the protrusion (3) (cross-sectional view taken along the line BB 'in FIG. 2) is gradually removed. It is inserted into the annular groove (2) with an increased compression amount, and as shown in FIG. 5, just before the completion of insertion into the annular groove (2), the maximum thickness portion (AA ′ sectional view in FIG. 2) is extremely small. Since it is press-fitted with a small amount of resistance, the mounting workability is greatly improved and a firm fixation is realized.

[0008]

【Example】

 In implementing the present invention, the wedge shape (3a) provided on the projection (3) is changed from a linear shape as shown in FIGS. 1, 2 and 3 to a water drop dropping shape having a radius (not shown). Various types of molding are possible, and it is selected depending on the combination with the gasket shape or the required degree of adhesion. Next, in terms of its shape, it is important that a protrusion (3) that gradually becomes wider and has a wall pressure is formed, and even in a situation where it is unavoidable to make it a site having a large area and a large mass. Pressing force is small and smooth and accurate insertion is guaranteed. As a matter of course, the wedge shape (3a) has directionality in the forward feeding direction of the gasket (4) to be inserted, and has a shape in which it makes an annular turn in the same direction, or has opposite directions to the left and right from the starting point. Various shapes such as left and right separate shapes can be molded.

[0009]

[Effect of device]

 As described above, the present invention is directed to the insertion and mounting of the gasket into the annular groove (2) of the cover member (1) due to the fall-off preventing structure of the protrusion (3) which is gradually widened in the annular direction. It has a very low torque and smoothness, and a small amount of compressive deformation of the contact tops of the protrusions (3) allows the gaskets to be fixed, thus preventing the material strain stress on the gasket body. Further, in the drop-out preventing action, the wedge shape (3a) which gradually increases the thickness and the inclination from the inserting direction provides a sufficient engaging force and a firm fixation.

[0010]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a side view showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a BB ′ portion shown in FIG. 2 is attached to a cover member.

5 is a cross-sectional view showing a state in which the AA ′ portion shown in FIG. 2 is attached to the cover member.

FIG. 6 is a cross-sectional view showing a conventional structure without using the present invention.

[0011]

[Explanation of symbols]

 1 Cover Member 2 Annular Groove 3 Projection 3a Wedge Shape 4 Gasket with Fall Prevention Structure

Claims (1)

[Scope of utility model registration request] 1. A gasket with a drop-out prevention structure, which is provided with a drop-out prevention projection partly protruding from a fitting peripheral surface to be inserted into an annular groove of a cover member, wherein the projection is a drop-out prevention structure gasket. A gasket with a captive structure, which is characterized by being shaped into a wedge shape with a direction that gradually becomes wider in the annular direction.