JP7090308B2 - gasket - Google Patents

Description

The present invention relates to, for example, a gasket that seals between a cylinder head of an internal combustion engine and a head cover.

The cylinder head and head cover of the internal combustion engine as described above are integrally fastened by a fastening member such as a bolt via a gasket (for example, Patent Documents 1 and 2). In the sealing device described in Patent Document 1, a fitting recess is formed along the peripheral wall portion of the head cover made of synthetic resin, and a gasket material is fitted into the fitting recess. In this sealing device, a collar is inserted into a plurality of bolt insertion holes formed in the peripheral wall of the head cover, a bolt is inserted through the collar, and the bolt is screwed into the cylinder head to connect the cylinder head and the head cover. It is integrated with the fastening. At this time, the cylinder head and the head cover are sealed by interposing a gasket, while the gasket material is also interposed between the bolt insertion hole and the collar.
Further, the head cover described in Patent Document 2 has a through hole formed in an inner portion in addition to the peripheral portion thereof, so that a bolt can be screwed into a cam cap via a collar inserted through the through hole. (See FIG. 4). Then, a sealing material is interposed between the through hole and the collar.

Japanese Unexamined Patent Publication No. 63-88375 Japanese Unexamined Patent Publication No. 2008-38760

By the way, as shown in Patent Document 2, when the head cover is fastened to the cam cap which is the covered body by bolts not in the peripheral portion but in the inner portion of the head cover, the width or diameter of the fastened surface of the covered body is used. If the size is small, it may not be possible to secure a space for interposing the sealing material between the through hole and the collar. Therefore, the seal between the through hole and the collar is not sufficiently sealed, and gas or the like in the cylinder head may leak to the outside from the bolt fastening portion, or outside air or muddy water containing dust may infiltrate into the cylinder head. Will be done.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gasket capable of suitably sealing a fastening portion with a fastening member even if the width or diameter of the surface to be fastened is small.

The gasket according to the present invention is a covered body in which a cover body made of synthetic resin having a through hole into which a tubular member is inserted and the cover body are integrally fastened by a fastening member inserted into the tubular member. A gasket placed between the body and the body, and is interposed between the one end surface of the tubular member in the axial direction and the fastened surface of the covered body facing the one end surface in a pressed state. The elastic sealing member is provided integrally with the surface sealing portion and is elastic between the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole in a state before fastening by the fastening member. The surface sealing portion includes a shaft sealing portion that is contacted and press-fitted with deformation, and the surface sealing portion has an annular first core material portion and an elastic material layer that covers the first core material portion. A disc portion orthogonal to the axial direction is provided, and the shaft seal portion extends axially from the disc portion and is integrally formed with the disc portion, and also has an outer peripheral surface of the tubular member and the through hole. A cylindrical portion extending so as to be interposed between the inner peripheral surface of the cylinder portion and the elastic sealing member integrally molded with the cylindrical portion are provided, and the cylindrical portion is an outer peripheral edge portion of the first core material portion. A second core material portion extending integrally along the axial direction is provided, and the second core material portion is covered with the elastic material layer covering the first core material portion and a series of elastic material layers. The elastic material layer is a compound layer formed by mixing a fiber material with a rubber base material, and the elastic sealing member is characterized by being a rubber elastomer .

According to the gasket of the present invention, even if the width and diameter of the fastened surface of the covered body are small, the surface sealing portion is interposed between one end surface of the tubular member and the fastened surface of the covered body. , It is possible to seal between one end surface of the tubular member overlapping in the axial direction and the fastened surface of the covered body. On the other hand, it is possible to seal between the tubular member and the through hole by press-fitting the shaft seal portion integrated with the surface seal portion between the inner peripheral surface of the tubular member and the outer peripheral surface of the through hole. can. Therefore, it is possible to prevent gas, oil, water, etc. existing on the covered body side from leaking to the outside through the through hole formed in the cover body. In addition, it is possible to prevent outside air containing dust, muddy water, and the like from entering the covered body .
Further, since the elastic material layer is a compound layer obtained by mixing a fiber material with a rubber base material, stress relaxation can be reduced as compared with an elastic material layer consisting only of a rubber base material, and the elastic sealing member is made of rubber. Since it is an elastomer, a sufficient reaction force can be obtained when sealing between the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole.

In the gasket of the present invention, in the pressed state of the surface sealing portion, a part of the elastic material layer is elastic between one end surface of the tubular member and the fastened surface of the covered body. It may be compressed as a target.
According to this, since the elastic material layer is elastically in close contact with each of the one end surface of the tubular member and the fastened surface of the covered body, the surface sealing portion is compared with the case of sealing with a rigid body such as a metal material. It is possible to improve the sealing property .

In the gasket of the present invention, the elastic sealing member of the shaft seal portion comes into contact with the first tightening allowance portion that comes into contact with the outer peripheral surface of the tubular member with a tightening allowance and the inner peripheral surface of the through hole with a tightening allowance. It may be provided with two tightening margins.
According to this, the gasket can be assembled to the cover body by press-fitting the shaft seal portion between the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole. Therefore, it is possible to save the trouble of managing the gasket.

In the gasket of the present invention, the width dimension of the fastened surface in the covered body is formed to be smaller than the inner diameter of the opening on the covered body side in the through hole, and the outer diameter of the disk portion in the surface sealing portion is It may be formed so as to be smaller than the inner diameter of the opening on the covered body side in the through hole and larger than the width dimension of the surface to be fastened.
According to this, the surface sealing portion is surely interposed between one end surface of the tubular member and the fastened surface of the covered body, and the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole are formed. In the meantime, the shaft seal portion can be reliably press-fitted.

According to the gasket of the present invention, even if the width and diameter of the surface to be fastened are small, the fastening portion can be preferably sealed.

(A) is an example to which the gasket according to the present invention is applied, and is a partially broken vertical cross-sectional view showing a state in which the cylinder head and the head cover are fastened with the gasket interposed therebetween, and (b) is (a). It is an enlarged view of the X part in 1 and is the figure which shows one Embodiment of the gasket which concerns on this invention. It is the same figure as FIG. 1 (b) which shows the modification of the same embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 (a) and 1 (b) show an example in which a gasket according to the present invention is interposed at a fastening portion between a cylinder head of an internal combustion engine and a head cover. In FIG. 1, a head cover 2 made of synthetic resin is fastened and integrated on a cylinder head 1 made of metal (including casting) via gaskets 3 and 4 at a peripheral portion and an inner portion. The gasket according to the present invention is mainly applied to the gasket 4 used in the inner portion.
In FIG. 1, the gasket 3 in the peripheral portion is made of an elastomer such as rubber, and is formed in an annular shape so as to be fitted into the annular groove 21 formed on the lower surface of the peripheral portion of the head cover 2. When the head cover 2 is fastened to the cylinder head 1 by the bolts 22, the gasket 3 in the peripheral portion is interposed between the upper surface surface 1a in the peripheral portion of the cylinder head 1 and the annular groove 21 in a compressed state. This prevents the high temperature gas from leaking to the outside of the cylinder head 1 and the inflow of external fluid including dust into the cylinder head 1.
In the present specification, the upper side of the paper surface of FIG. 1 is referred to as the upper side, and the lower side of the paper surface is referred to as the lower side.

In the gasket 4 of the present embodiment, the head cover 2 is formed by a head cover (cover body) 2 having a through hole 23 into which a collar (cylindrical member) 5 is inserted, and a bolt (fastening member) 6 inserted through the collar 5. It is arranged between the cylinder head (covered body) 1 to be integrally fastened. The gasket 4 of the present embodiment includes a surface sealing portion 41 and a shaft sealing portion 42. The surface seal portion 41 is interposed between the lower end surface (one end surface in the axis L direction) 5a of the collar 5 and the fastened surface 10a of the cylinder head 1 facing the lower end surface 5a of the collar 5 in a pressed state. Further, the shaft seal portion 42 is press-fitted between the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 of the through hole 23. The inner peripheral surface 230 of the through hole 23 includes a small diameter portion 230a having substantially the same diameter (slightly large) as the outer diameter of the collar 5, and a large diameter portion 230b connected in a stepped shape below the small diameter portion 230a. The through hole 23 is provided in the inner portion of the head cover 2 in the surface area direction, and is positioned so as to face the upper surface (fastened surface) 10a of the pedestal portion 10 provided in the inner portion of the cylinder head 1. The pedestal portion 10 is formed with a female screw portion 10b along the vertical direction (axis L direction). The pedestal portion 10 is provided as necessary due to the configuration of the cylinder head 1, and is formed in a block shape exposed on the upper part of the cylinder head 1 or in a bridge shape such as a bridge between facing peripheral portions. .. A downward boss portion 20 is formed on the lower surface of the head cover 2 facing the pedestal portion 10 and facing the fastened surface 10a, and the through hole 23 is formed in the boss portion 20. There is.

The surface sealing portion 41 includes an annular first core material portion 410 made of a metal material, and an elastic material layer 411 covering both surfaces of the first core material portion 410. Further, in the present embodiment, the first core material portion 410 is formed into a disk shape, and the second core material portion 420 extends upward integrally along the axis L direction from the outer peripheral edge portion of the first core material portion 410. Is formed. The second core material portion 420 is made of a metal material like the first core material portion 410, and is formed in a cylindrical shape. Both sides of the second core material portion 420 are covered with the elastic material layer 411 and a series of elastic material layers 421. The gasket 4 of the present embodiment includes a disk portion 4A composed of a first core material portion 410 and an elastic material layer 411, and a cylindrical portion 4B composed of a second core material portion 420 and an elastic material layer 421. The cylindrical portion 4B extends so as to be interposed between the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 (large diameter portion 230b) of the through hole 23, and the elastic sealing member 43 described later is integrated with the cylindrical portion 4B. The shaft seal portion 42 is formed by the molding.

The elastic material layers 411 and 421 are compound layers formed by mixing a fiber material with a rubber material. Specifically, the compound layer contains a compound containing a base fiber composed of a compressible inorganic fiber other than asbestos and a compressible organic fiber, a rubber material, a rubber chemical, and an inorganic filler as a core material (a core material). It is a layer formed by coating the surface of the first core material portion 410 and the second core material portion 420). Further, the elastic sealing member 43 is made of an elastomer such as rubber. The elastic seal member 43 is integrally formed with the cylindrical portion 4B by insert molding, and is also formed in an annular shape. The elastic sealing member 43 is formed so as to straddle the end surface of the cylindrical portion 4B and cover the inner peripheral side and the outer peripheral side of the cylindrical portion 4B. The elastic sealing member 43 is configured to have a higher elastic modulus than the elastic material layers 411 and 421. The elastic seal member 43 includes a first tightening allowance portion 43a formed on the inner peripheral side of the elastic seal member 43 and in contact with the outer peripheral surface 5b of the collar 5 with a tightening allowance. Further, the elastic seal member 43 includes a second tightening margin portion 43b formed on the outer peripheral side of the elastic seal member 43 and in contact with the inner peripheral surface 230b of the through hole 23 with a tightening margin. The first tightening margin 43a is a ridge protruding toward the center of the gasket 4, while the second tightening margin 43b protrudes toward the side opposite to the center of the gasket 4 and is along the center of the gasket. It is a ridge with a substantially triangular cross section. When the shaft seal portion 42 is press-fitted between the collar 5 and the through hole 23, the first tightening margin portion 43a and the second tightening margin portion 43b are inside the outer peripheral surface 5b and the through hole 23 of the collar 5, respectively. It comes into contact with the peripheral surface 230 (large diameter portion 230b) with elastic deformation. In FIG. 1 (b), the shapes of the first tightening margin portion 43a and the second tightening margin portion 43b before elastic deformation are shown by a two-dot chain line.

In the present embodiment, the width dimension of the fastened surface 10a in the cylinder head 1 (outer diameter when the fastened surface 10a is circular) d2 is the inner diameter (large diameter portion) of the opening on the fastened surface 10a side in the through hole 23. It is formed smaller than the inner diameter of 43b) d. Further, the outer diameter d1 of the disk portion 4A in the surface sealing portion 41 is smaller than the inner diameter (same as above) d of the opening on the side to be fastened surface 10a in the through hole 23, and the width dimension of the fastened surface 10a (same as above). It is formed so as to be larger than d2.

Next, a procedure for fastening the head cover 2 at the inner portion of the cylinder head 1 using the gasket 4 configured as described above will be described. First, the collar 5 is inserted through the through hole 23 with the inner surface (lower surface) of the head cover 2 facing upward. Next, the shaft seal portion 42 of the gasket 4 is press-fitted between the inner peripheral surface 230 (large diameter portion 230b) of the through hole 23 and the outer peripheral surface 5b of the collar 5. In this state, the head cover 2 is inverted, and the gasket 4 is arranged so that the surface sealing portion 41 rests on the pedestal portion 10 of the cylinder head 1. At this time, since the first tightening margin portion 43a and the second tightening margin portion 43b of the elastic sealing member 43 are in contact with the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 of the through hole 23, respectively, with a tightening margin, the gasket 4 Is held by its tense reaction force. Therefore, when the head cover 2 is assembled to the cylinder head 1, the gasket 4 does not fall, and the labor of management at the time of assembling the gasket 4 can be omitted. Further, the bolt (fastening member) 6 provided with the washer 6a is inserted into the collar 5 and screwed into the female threaded portion 10b of the pedestal portion 10 of the cylinder head 1. The outer diameter of the washer 6a is larger than the inner diameter of the through hole 230 (small diameter portion 230a), and by screwing the bolt 6, the head cover 2 is inserted into the cylinder head 1 via the collar 5 and the surface sealing portion 41 of the gasket 4. It is fastened to the pedestal portion 10. At this time, although the head cover 2 is made of synthetic resin, the collar 5 and the boss portion 20 are present, so that the head cover 2 is prevented from being damaged at the time of fastening.

In this fastened state, the surface seal portion 41 is interposed between the lower end surface 5a of the collar 5 and the upper surface (fastened surface) 10a of the pedestal portion 10 in a pressed state. When the surface seal portion 41 is pressed, the elastic material layer 411 constituting the surface seal portion 41 is compressed. Therefore, due to the compression reaction force, between the lower end surface 5a of the collar 5 and the upper surface 10a of the pedestal portion 10. Is well sealed. In particular, since the elastic material layer 411 is elastically in close contact with each of the lower end surface 5a of the collar 5 and the fastened surface 10a of the cylinder head 1, the surface sealing portion 41 is compared with the case of sealing with a rigid body such as a metal material. It is possible to improve the sealing property. In addition, since the elastic material layer 411 is a compound layer made by mixing a fiber material with a rubber base material, stress relaxation can be reduced as compared with an elastic material layer made of only a rubber base material. Further, the shaft seal portion 42 is in a state of being press-fitted between the inner peripheral surface 230 (large diameter portion 230b) of the through hole 23 and the outer peripheral surface 5b of the collar 5. In this press-fitting state, the first tightening margin portion 43a of the elastic sealing member 43 elastically contacts the outer peripheral surface 5b of the collar 5 with a predetermined tightening margin, and the second tightening margin portion 43b is the inner circumference of the through hole 23. It elastically contacts the surface 230 (large diameter portion 230b) with a predetermined tightening allowance. As a result, the space between the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 of the through hole 23 is well sealed. Therefore, the fastening portion of the inner portion between the cylinder head 1 and the head cover 2 is properly sealed by the bolt 6, and the leakage of the internal fluid and the infiltration of the external fluid at this portion are prevented.

In the sealing structure using the gasket 4 of the present embodiment, the width dimension d2 of the upper surface 10a of the pedestal portion 10 which is the fastened surface is small, but the outer diameter d1 of the disk portion 4A in the surface sealing portion 41 is the fastened surface 10a. It is formed larger than the width dimension d2 of. Therefore, the surface sealing portion 41 can be reliably interposed between the lower end surface 5a of the collar 5 and the surface to be fastened 10a. Further, since the inner diameter d of the large diameter portion 230b in the through hole 23 is larger than the outer diameter d1 of the disk portion 4A, it is between the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 (large diameter portion 230b) of the through hole 23. The shaft seal portion 42 can be reliably press-fitted. Since the disk portion 4A and the cylindrical portion 4B are reinforced by the integrated first core material portion 410 and the second core material portion 420, a series of shapes of the disk portion 4A and the cylindrical portion 4B are maintained. Further, since the cylindrical portion 4B functions as the core material of the shaft sealing portion 42, a sufficient antiverse is sufficient when sealing between the outer peripheral surface 5b of the collar 5 and the inner peripheral surface 230 of the through hole 23 by the elastic sealing member 43. You can get power.
In parallel with or before and after the fastening operation in the inner portion, the fastening operation between the cylinder head 1 and the head cover 2 by the bolt 22 via the gasket 3 is also performed in the peripheral portion. As a result, the cylinder head 1 and the head cover 2 are also prevented from leaking the internal fluid and infiltrating the external fluid in the peripheral portion.

FIG. 2 shows a modified example of the embodiment. In this example, the second core material portion 420 constituting the cylindrical portion 4B is not covered with the elastic material layer 421 as in the above example, and the elastic sealing member 43 is directly integrally fixed to the second core material portion 420. ing. Since the elastic sealing member 43 is integrated with the second core material portion 420 without interposing the elastic material layer, this integration is strengthened in the case of insert molding.
Since the other configurations are the same as those of the above-described embodiment, the same reference numerals are given to the common parts and the description thereof will be omitted.

It is also possible to adopt the fastening structure shown in the embodiment also in the peripheral portions of the cylinder head 1 and the head cover 2. Further, the shapes of the surface seal portion 41, the shaft seal portion 42, the elastic seal member 43, and the like are not limited to the examples shown in the drawings, and may be other shapes. For example, in the above-described embodiment, the elastic sealing member 43 has a first tightening margin portion 43a and a second tightening margin portion 43b, but either of the first tightening margin portion 43a and the second tightening margin portion 43b. May be omitted. Further, the shapes of the first tightening margin portion 43a and the second tightening margin portion 43b are not limited to the ridges, and may be changed as appropriate.
Further, the thickness relationship between the first core material portion 410 and the second core material portion 420 and the elastic material layer 411,421 exaggerates the thickness of the elastic material layer 411,421 in the figure. Not limited to other thickness relations may be used. For example, the thickness of the elastic material layers 411 and 421 may be thinner than the thickness of the first core material portion 410 and the second core material portion 420. Further, in the above-described embodiment, the gasket 4 provided with the elastic material layers 411 and 421 is disclosed, but the gasket may be a gasket in which the elastic material layers 411 and 421 are not present.
Further, the first core material portion 410 and the second core material portion 420 are not limited to those made of a metal material, and may be made of, for example, a synthetic resin having a higher rigidity than the elastic material layers 411 and 421 .
In addition, it goes without saying that the shapes of the cylinder head 1 and the head cover 2 are also schematically shown in the figure and do not necessarily match the actual shapes. Further, in the embodiment, the gasket applied to the fastening portion between the cylinder head and the head cover has been described, but the present invention is not limited to this, and the cover body made of synthetic resin is airtightly or liquid-tightly fastened to the covered body. The present invention is equally applicable to other cases in which it is required to do so.

1 Cylinder head (covered body)
10a Fastened surface 2 Head cover (cover body)
23 Through hole 230 Inner peripheral surface 230a Small diameter part (inner peripheral surface)
230b Large diameter part (inner peripheral surface)
4 Gasket 4A Disk part 4B Cylindrical part 41 Surface sealing part 410 1st core material part 411 Elastic material layer 42 Shaft sealing part 420 2nd core material part 421 Elastic material layer 43 Elastic sealing member 43a 1st tightening margin 43b 2nd Tightening margin 5 collar (cylindrical member)
5a Lower end surface (one end surface)
5b Outer peripheral surface 6 bolts (fastening member)
d Inner diameter of the covered body side in the through hole d1 Outer diameter of the disk part in the surface seal part d2 Width dimension (outer diameter) of the to be fastened surface
L axis

Claims (4)

Arranged between a cover body made of synthetic resin having a through hole into which a tubular member is inserted and a covered body to which the cover body is integrally fastened by a fastening member inserted into the tubular member. It is a gasket that is used
A surface seal portion interposed between an axial end surface of the tubular member and a fastened surface of the covered body facing the one end surface in a pressed state.
The elastic sealing member is provided integrally with the surface sealing portion, and the elastic sealing member comes into contact with the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole with elastic deformation in the state before fastening by the fastening member. With a shaft seal that is press-fitted,
The surface sealing portion includes an annular first core material portion and an elastic material layer covering the first core material portion, and includes a disk portion orthogonal to the axial direction.
The shaft seal portion extends axially from the disc portion and is integrally formed with the disc portion, and is interposed between the outer peripheral surface of the tubular member and the inner peripheral surface of the through hole. A cylindrical portion extending and the elastic sealing member integrally molded with the cylindrical portion are provided.
The cylindrical portion includes a second core material portion that extends integrally along the axial direction from the outer peripheral edge portion of the first core material portion, and the second core material portion covers the first core material portion. Covered with an elastic layer and a series of elastic layers,
The elastic material layer is a compound layer formed by mixing a fiber material with a rubber base material, and the elastic sealing member is a gasket characterized by being a rubber elastomer . In the gasket according to claim 1,
In the pressed state of the surface sealing portion, a part of the elastic material layer is elastically compressed between the one end surface of the tubular member and the fastened surface of the covered body. A gasket characterized by. In the gasket according to claim 1 or 2.
The elastic seal member includes a first tightening allowance portion that comes into contact with the outer peripheral surface of the tubular member with a tightening allowance, and a second tightening allowance portion that comes into contact with the inner peripheral surface of the through hole with a tightening allowance. A gasket characterized by that. In the gasket according to any one of claims 1 to 3.
The width dimension of the surface to be fastened in the covered body is formed to be smaller than the inner diameter of the opening on the covered body side in the through hole.
The outer diameter of the disk portion in the surface seal portion is smaller than the inner diameter of the opening on the covered body side in the through hole, and is formed so as to be larger than the width dimension of the to be fastened surface. Gasket.

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