JPH0643572Y2 - Metal gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a metal gasket used for sealing a joint surface between a cylinder head and a cylinder block of an internal combustion engine, particularly a multi-cylinder internal combustion engine, and more specifically, a cylinder. The present invention relates to a metal gasket in which an adjusting plate and a grommet substrate are laminated on a bead substrate made of an elastic metal plate in which beads are formed in a contour shape along each peripheral edge of an opening for a bore.

(Prior Art) As shown in FIG. 5, a metal gasket of this type has a bead substrate 2 of a thickness b formed of an elastic metal plate having beads 1 inwardly formed along the periphery of an opening for a cylinder bore. The adjustment plate 3 of a and the grommet substrate 4 of thickness c are laminated,
The inner peripheral edge of the grommet substrate 4 is folded back to enclose the inner peripheral edge of the bead substrate 2 and the adjusting plate 3 so that the encapsulating portion has a stopper function for the bead portion and stress on the bead portion is prevented. We are trying to reduce it.

(Problems to be solved by the invention) However, in the above-described conventional metal gasket, the shim effect due to the difference between the thickness Ta of the enclosing portion (hereinafter referred to as the grommet portion) and the thickness Tb of the three-layer laminated portion is Ta- Since Tb = c, it is determined by the thickness of the grommet substrate. Therefore, unless the difference in thickness between the three-layer laminated portion and the grommet portion is adjusted by changing the thickness of the grommet substrate, the surface pressure distribution between the bead portion and the grommet portion cannot be adjusted.

Moreover, if the grommet board is thickened to adjust the surface pressure distribution, the spring characteristics of the grommet part can be improved, but the surface pressure is concentrated on the grommet part (because the stopper function is too hard), and the spring characteristics of the bead part. Cannot be fully utilized, and cannot function as a gasket. Further, when the grommet substrate is made thin, the strength becomes weak and cracks are easily generated in the grommet portion, which causes a problem in durability.

(Object of the Invention) The present invention provides a metal gasket capable of finely adjusting a surface pressure of a grommet portion in a wide range without changing the thickness of a grommet substrate in order to adjust the surface pressure of the engine head rigidity. Is intended.

(Means for Solving the Problem) Means for achieving the above-mentioned object are as follows: a bead substrate 2 made of an elastic metal plate having beads 1 formed along the peripheral edge of each of the parallel cylinder bore openings A and an adjusting plate 3; In the metal gasket in which the grommet substrate 4 and the grommet substrate 4 are laminated, the opening diameter for the cylinder bore of the adjusting plate 3 is made larger than the opening diameter for the cylinder bore of the bead substrate 2, and the inner peripheral edge 5 of the bead substrate 2 is provided on the inner circumference of the adjusting plate 3. In addition to projecting, the projecting inner peripheral edge 5 is provided with a step 6 to be laminated on the grommet substrate 4, and the inner peripheral edge 5 is folded back to enclose the grommet substrate 4, and the encapsulating portion has three thicknesses. It should be larger than the thickness.

(Example) The structure of the metal gasket according to the present invention will be described based on an example.

FIG. 1 is a partial plan view of a metal gasket G showing a first embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along the line II of FIG. 1, and FIG. 3 is a sectional view taken along the line II-II of FIG. Figure,
A bead substrate 2 made of an elastic metal plate in which the openings A for cylinder bores are arranged in parallel at the center of the width, and inward beads 1 are formed along the periphery of the openings A for cylinder bores.
It is basically based on a metal gasket in which the adjusting plate 3 and the grommet substrate 4 are laminated.

According to the present invention, in the above-mentioned basic metal gasket, the opening diameter D1 for the cylinder bore of the adjusting plate 3 using the elastic metal plate of the thickness a is smaller than the opening diameter D2 for the cylinder bore of the bead substrate 2 of the thickness b. In general, the inner peripheral edge 5 of the bead substrate 2 is projected to the inner periphery of the adjusting plate 3, and a step 6 is provided on the projecting inner peripheral edge 5 so that the grommet substrate 4 having a thickness c is laminated and adhered thereto. The peripheral edge 5 is grommet-processed by folding back the grommet substrate 4, and the thickness Ta of the grommet portion is made larger than the three laminated portion thickness Tb.

As shown in FIG. 3, the bolt hole 8 is provided with an adjusting plate 3
A hole 9 larger than the bolt hole 8 of the bead substrate 2 is formed.
Is formed on the grommet substrate 4 by forming the step 6a.

The water holes and oil holes other than the bolt holes 8 have the same structure as the bolt holes 8 although they are omitted in the drawing.

In the metal gasket constructed as described above, the thickness of the grommet portion Ta = 2c + b, the thickness of the three-layer laminated portion Tb = a + b + c, and the effect of the shim of the grommet portion on the bead = Ta−Tb = c−a. As described above, the shim effect can be finely adjusted by changing the thickness of the adjusting plate 3 when the predetermined grommet substrate 4 is used.

FIG. 4 shows the second embodiment, and similarly to the first embodiment, the cylinder bore openings A are arranged side by side at the center of the width, and the inner portions are formed along the periphery of the respective cylinder bore openings A. It is based on a metal gasket in which an adjusting plate 3 and a grommet substrate 4 are laminated on a bead substrate 2 made of an elastic metal plate on which a bead 1 oriented is formed. Cylinder bore opening diameter D1
Is the opening diameter for the cylinder bore of the bead substrate 2 having the thickness b.
The inner peripheral edge 5 of the bead substrate 2 is projected to the inner periphery of the adjusting plate 3 to be larger than D2, and the step 6 is provided on the projecting inner peripheral edge 5 so as to be laminated on the grommet substrate 4 of thickness c, and The inner peripheral edge 5 is grommet-processed by folding back the grommet substrate 4, and when the thickness Ta of the grommet portion is made larger than the three laminated portion thickness Tb, between the adjusting plate 3 and the grommet substrate 4 and between the grommet portion and the bead substrate 2. Gaps 7a, 7b between the inner peripheral edge 5
Is formed to give a spring characteristic.

By forming the gaps 7a and 7b in this way, it is possible to follow the movement due to the deflection of the head during engine operation, maintain the surface pressure distribution appropriately, and secure the sealing effect.

Although not shown in the drawings, in the first and second embodiments described above, both surfaces of the bead substrate 2 and the exposed surface of the grommet substrate 4 are coated with a heat-resistant resin or rubber, or both surfaces of the bead substrate 2 are heat-resistant. It is also possible to coat a heat-resistant resin or rubber on the upper and lower surfaces again after assembling, and further improve the sealing property.

Further, in the above-described embodiment, the bead 1 is described as being inward along the peripheral edge of the cylinder bore opening A, but the present invention is not limited to this.

(Advantageous Effects of the Invention) The present invention is a metal gasket in which an adjusting plate 3 and a grommet substrate 4 are laminated on a bead substrate 2 made of an elastic metal plate having beads 1 formed along the peripheral edges of the openings A for cylinder bores arranged in parallel. In the above, the opening diameter for the cylinder bore of the adjusting plate 3 is set to be larger than the opening diameter for the cylinder bore of the bead substrate 2, and the inner peripheral edge 5 of the bead substrate 2 is projected to the inner periphery of the adjusting plate 3 and Step 6 on edge 5
Is provided and laminated on the grommet substrate 3, and the inner peripheral edge 5
Since the grommet substrate 4 is folded back and wrapped, and the thickness of the wrapped portion is made larger than the thickness of the three laminated parts, a two-step surface pressure distribution configuration is obtained, and the surface pressure distribution is determined by the thickness of the grommet substrate 4. Fine adjustment can be freely performed by changing the thickness of the adjusting plate 3 while keeping the predetermined thickness, a well-balanced two-stage surface pressure distribution can be secured, and an excellent sealing effect can be achieved.

Further, since it is not necessary to change the thickness of the grommet substrate 4 to adjust the surface pressure distribution, unlike the conventional case, the surface pressure concentration or crack due to the change of the grommet substrate for the surface pressure distribution adjustment does not occur, and A proper stopper function can be ensured, the spring characteristics of the bead portion can be fully utilized, a sufficient function as a gasket can be exerted, and durability can be improved.

[Brief description of drawings]

1 is a partial plan view of a metal gasket G showing a first embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along the line I-I of FIG. 1, and FIG. 3 is a line II-II of FIG. Sectional view at 4th
FIG. 5 is an enlarged cross-sectional view of a portion corresponding to the II line of FIG. 1 showing the second embodiment, and FIG. 5 is an enlarged cross-sectional view of the conventional metal laminated gasket of the I-I line portion of FIG. 1 ... Bead, 2 ... Bead substrate 3 ... Adjusting plate, 4 ... Grommet substrate 5 ... Inner peripheral edge, 6 ... Steps 7a, 7b ... Gap A ... Cylinder bore opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Ii, 248 Kano, Higashiosaka, Osaka Prefecture, Japan Gasket Co., Ltd. (72) Inventor, Kunitoshi Inoue, 248, Kano, Higashiosaka, Osaka Stocks, Nippon Gasket In-company (56) Bibliographic flats 2-31364 (JP, U) Real flats 2-25770 (JP, U) Real flats 2-22656 (JP, U) Real flats 2-14444 (JP, U) )

Claims (3)

[Scope of utility model registration request] 1. A metal gasket in which an adjusting plate 3 and a grommet substrate 4 are laminated on a bead substrate 2 made of an elastic metal plate on which beads 1 are formed along the respective peripheral edges of parallel cylinder bore openings A. The opening diameter for the cylinder bore is larger than the opening diameter for the cylinder bore of the bead base plate 2, and the inner peripheral edge 5 of the bead base plate 2 is extended to the inner periphery of the adjusting plate 3, and the step 6 is formed on the extended inner peripheral edge 5. And a grommet substrate 4 are laminated on the grommet substrate 4, and the grommet substrate 4 is folded and wrapped around the inner peripheral edge 5, and the thickness of the enclosing portion is made larger than the thickness of three laminated portions. 2. The metal gasket according to claim 1, wherein gaps 7a, 7b are formed between the adjusting plate 3 and the grommet substrate 4, and between the folded portion of the grommet substrate 4 and the inner peripheral edge 5 of the bead substrate 2. 3. The metal gasket according to claim 1, wherein both surfaces of the adjusting plate 3 and the exposed surface of the grommet substrate 4 are coated with heat resistant resin or heat resistant rubber.