JP5636579B2 - gasket - Google Patents

Description

  The present invention is a gasket interposed between two members fastened by a fastening member, and in particular, the combined surface around the space to be sealed is inclined with respect to the fastening direction by the fastening member. The present invention relates to an annular gasket interposed therebetween.

  A gasket is interposed at the joint between the cylinder head of the automobile engine and the intake manifold. Patent Document 1 discloses a gasket that is interposed between a cylinder head of an V-type engine and an intake manifold. In the case of a V-type engine, the cylinder head is formed obliquely with respect to the engine body. Therefore, the joint portion with the intake manifold (both merged surfaces) is also relative to the body axis of the engine body (vertical line with respect to the installation surface). It is assumed that it is tilted. In Patent Document 1, when the tilted portion is fastened and joined by a fastening member such as a bolt, the tool interferes with the intake manifold, resulting in poor workability. Therefore, the fastening direction of the bolt is along the body axis of the engine. I am doing so. For this reason, the combined surface of the cylinder head and the intake manifold is inclined with respect to the fastening direction of the bolt.

JP-A-5-306777

  FIG. 5 is different in shape from the gasket disclosed in Patent Document 1, but as described above, in the portion where the combined surface of the cylinder head and the intake manifold is inclined with respect to the fastening direction of the fastening member. An example of the gasket interposed between the said coalescing surfaces is shown typically. As shown in the figure, the cylinder head 100 and the intake manifold 101 are formed in an inclined state with respect to the body axis of an engine body (not shown). Then, the cylinder head 100 and the intake manifold 101 are fastened together by bolts (not shown) in a state along the body axis, with the gasket 102 interposed between the combined surfaces 100a and 101a. As a result, the sealing target spaces 100b and 101b of the cylinder head 100 and the intake manifold 101 are sealed. The gasket 102 includes a core substrate 103 and annular gasket bodies 104 and 105 each having a chevron-shaped cross section made of a rubber molded body fixed and integrated on both surfaces of the core substrate 103.

  FIG. 5 shows an example in which the cylinder head 100 is made of a cast metal body such as aluminum, and the intake manifold is made of a synthetic resin molding. Recently, in order to improve fuel efficiency, automobiles have been made lighter in their components, and engines such as intake manifolds made of synthetic resin have been used. Normally, a metal gasket is interposed between the metal members to provide a seal between them, but at the joint between the synthetic resin member and the metal member, the synthetic resin member is deformed by the fastening pressure. For this reason, a gasket made of an elastic member such as rubber is interposed between the two so as to be sealed.

  In the joining structure of the cylinder head 100 and the intake manifold 101 as shown in the drawing, the direction along the one-dot chain line 106 with respect to the gasket bodies 104 and 105 by the merged surfaces 100a and 101a ( The compressive stress acts in the fastening direction of the bolt, that is, the direction along the body axis. Since the combined surfaces 100a and 101a are inclined with respect to the fastening direction of the bolt, as shown in the figure, the gasket 102 interposed therebetween is also inclined. When the combined surfaces 100a and 101a are fastened so as to reach the position indicated by the two-dot chain line, the gasket bodies 104 and 105 receive fastening pressure (compressive stress) along the fastening direction 106, and the fastening direction 106 and the core substrate. It deform | transforms so that the plate | board surface direction 103a of 103 may fall to the side which makes an obtuse angle (refer the part shown with the dashed-two dotted line of the gasket main bodies 104 and 105). As described above, when the gasket main bodies 104 and 105 are deformed so as to fall down at the time of fastening, the surface pressure between the combined surfaces 100a and 101a and the gasket main bodies 104 and 105 is not uniform in the circumferential direction, which affects the sealing performance. Will be affected. In particular, it is inevitable to use a gasket made of an elastic material such as rubber at the joint between the synthetic resin member and the metal member, and the combined surfaces of the members are inclined with respect to the fastening direction of the fastening member. In such a case, such a problem is likely to occur, and improvement has been desired.

  The present invention has been made in view of the above circumstances, and has a gasket body made of an elastic member such as rubber, and the gasket body falls down even when the united surface to be sealed is inclined with respect to the fastening direction. An object of the present invention is to provide a gasket that can be interposed between the combined surfaces without impairing the sealing performance.

In the gasket according to the present invention, the union surface around the space to be sealed in the two members tightened and joined by the fastening member is interposed between the union surfaces inclined without being orthogonal to the fastening direction by the fastening member. A gasket formed of a core substrate and an annular gasket body having an angled cross section made of an elastic body fixed and integrated on both surfaces of the core substrate, and the gasket body is a combined surface around the space to be sealed In the part located on the uppermost side and the lowermost side part of the inclined direction, the inclined portion located on the side where the fastening direction by the fastening member and the plate surface direction of the core substrate form an obtuse angle with respect to the plate surface of the core substrate The rising angle is a mountain-shaped cross-sectional shape that is smaller than the rising angle of the slope portion positioned on the acute angle side with respect to the plate surface of the core substrate .

  In the present invention, the gasket body has a mountain shape in which the cross-sectional shape of the portion located in the intermediate portion in the inclined direction is substantially line symmetrical, and the portion located in the intermediate portion and the uppermost side and the lowermost side portion It is desirable that the cross-sectional shape is formed so as to continuously change along the circumferential direction between the portions located. The gasket main body may be made of a rubber molded body.

  In the present invention, the two members may be a cylinder head and an intake manifold of an internal combustion engine. In this case, the cylinder head may be made of metal, and the intake manifold may be made of synthetic resin.

Since the combined surface around the space to be sealed in the two members in which the gasket of the present invention is interposed is inclined without being orthogonal to the fastening direction by the fastening member, in this combined state, the gasket is also in the combined surface. It interposes in an inclined state following the copying. The gasket of the present invention comprises a core substrate and an annular gasket body having an angled cross section made of an elastic body fixed and integrated on both surfaces of the core substrate. The two reaction surfaces are sealed by the compression reaction force. The gasket main body has an obtuse angle between the fastening direction by the fastening member and the plate surface direction of the core substrate at a position located on the uppermost side and the lowermost side of the united surface around the space to be sealed. The rising angle of the slope portion positioned on the side forming the core substrate with respect to the plate surface of the core substrate is smaller than the rising angle of the slope portion positioned on the side forming the acute angle with respect to the plate surface of the core substrate. Since the cross-sectional shape of the mountain is gentler than the latter slope part , the slope part located on the side forming the obtuse angle with respect to the perpendicular from the peak of the mountain shape to the core substrate is on the side making the acute angle. From the slope part located, it will form substantially thickly. Therefore, the resistance of the slope portion located on the obtuse angle side with respect to the fastening pressure (compression stress) accompanying the fastening is large, and the portions located on the uppermost side and the lowermost side portion in the inclination direction of the gasket body during fastening. Is less likely to be compressed and deformed so as to collapse. As a result, the compression surface pressure with the coalesced surface over the entire circumferential direction of the annular gasket body is made uniform, and the desired sealing performance is accurately exhibited.

  Even if the merged surface is inclined as described above, the fastening pressure acts substantially uniformly with respect to the width direction of the gasket in the intermediate portion in the inclined direction, so the cross-sectional shape of the portion located in the intermediate portion in the inclined direction However, when it is made into the substantially line symmetrical mountain shape, it does not deform | transform so that the gasket main body of this intermediate part may fall down either in the width direction. And the direction where the said fastening pressure acts with respect to the width direction of the gasket main body at the time of the fastening changes continuously between the part located in the middle part and the part located in the uppermost part and the lowermost part. However, it is assumed that the cross-sectional shape is formed so as to continuously change along the circumferential direction between the portion located in the intermediate portion and the portions located in the uppermost side and the lowermost side portion. As a result, the drag of the gasket body also changes in accordance with the change in fastening pressure, and the prevention of falling deformation over the entire circumference is more effectively exhibited.

  If the gasket body is made of a rubber molded body, it can be easily fixed and integrated with the core substrate by vulcanization molding, and the gasket body whose cross-sectional shape continuously changes along the circumferential direction is also simple. Can be formed. Then, the surface pressure is suitably expressed by the elastic reaction force unique to the rubber when interposed between the combined surfaces to be sealed in a compressed state, and the sealing between the combined surfaces is more surely performed.

  When the two members are a cylinder head and an intake manifold of an internal combustion engine, the above-mentioned specific problem can be caused by the fact that the combined surface is inclined with respect to the fastening direction at the joint between the cylinder head and the intake manifold. It will be eliminated as much as possible. Even when the cylinder head is made of metal and the intake manifold is made of synthetic resin, the gasket main body is made of an elastic member, so that there is no concern that the intake manifold will be deformed at the time of fastening.

It is a top view which shows an example of the gasket of this invention. It is an expanded sectional view corresponding to the XX arrow line part in Drawing 1 showing the example of use of the gasket. It is a partially broken expanded sectional view of the XX line arrow part in FIG. It is a partial fracture expanded sectional view of the YY line arrow part in FIG. It is a figure similar to FIG. 2 which shows the usage example of the conventional gasket.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a gasket applied to a joint portion between a cylinder head and an intake manifold in an automotive V-type engine. The gasket 3 shown in the figure is interposed between the combined surfaces of three cylinder heads arranged in series in a bank on one side of a 6-cylinder V-type engine (not shown) and an intake manifold joined to each cylinder head. Therefore, it is configured as one gasket that collects three joint portions. The gasket 3 in the illustrated example includes a core substrate 4 in which three through holes 4a corresponding to seal target voids in each joint section described later are opened in parallel, and both surfaces of the core substrate 4 around the through holes 4a. It is composed of annular gasket bodies 5 and 6 having a chevron-shaped cross section that are fixedly integrated. Each of the gasket bodies 5 and 6 has a mountain-shaped cross section including inner peripheral slopes 5a and 6a and outer peripheral slopes 5b and 6b, and the slopes of these slopes 5a, 6a, 5b and 6b are circumferential. It is formed so as to differ depending on the portion of the direction. The core substrate 4 is made of a metal plate or a synthetic resin plate, and has bolt insertion holes 4b as fastening members for fastening the intake manifold to the cylinder head at four locations.

  In the illustrated example, the gasket bodies 5 and 6 are made of a rubber vulcanized molded body, and are integrally formed on a predetermined portion of the core substrate 4 by vulcanization molding. The rubber materials constituting the gasket bodies 5 and 6 include ethylene propylene rubber (EPDM), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), acrylic rubber (ACM), hydrogenated acrylonitrile butadiene rubber (HNBR), silicone. Rubber (VMQ), fluorosilicone rubber (FVMQ), fluoro rubber (FKM), etc. are employed. In addition, it is also possible to comprise the gasket main bodies 5 and 6 with the molded body of elastic resin.

  In the gasket 3, as shown in FIG. 2, the combined surface of the cylinder head and the intake manifold is inclined without being orthogonal to the bolt fastening direction (usually perpendicular to the engine installation surface). It is configured to be applied to. The white arrow shown in FIG. 1 has shown the inclination direction from which an arrow head part becomes downward. The upper side in the tilt direction means the arrowhead side of the white arrow, and the lower side means the arrowhead side. The bolt insertion hole 4b is formed in an elliptical shape in which the inclined direction is the major axis as it is disposed obliquely with respect to the bolt fastening direction. 2 and 3 are cross-sectional views along a line (XX line in FIG. 1) connecting the uppermost part and the lowermost part in the inclined direction of the annular gasket bodies 5 and 6; FIG. 2 shows a cross-sectional view corresponding to this portion in a state of being interposed between the cylinder head 1 and the intake manifold 2.

  As shown in FIG. 2, the cylinder head 1 includes a pair of banks (not shown) inclined in a V shape with respect to a body axis (normally perpendicular to the installation surface of the engine) of a V type engine body (not shown). Formed. The intake manifold 2 is fastened and integrated with the cylinder head 1 via the gasket 3 by means of bolts (not shown) as fastening members. Since the bank is inclined, the combined surfaces 1a and 2a of the cylinder head 1 and the intake manifold 2 formed in the bank are also inclined as shown in the figure. The white arrow shown in FIG. 2 also shows this inclination direction like FIG. The cylinder head 1 and the intake manifold 2 have seal target cavities 1b and 2b, and the gasket main bodies 5 and 6 are arranged at the peripheral edges of the openings of the seal target cavities 1b and 2b. In the illustrated example, the cylinder head 1 is made of a cast body made of a metal such as aluminum, and the intake manifold 2 is made of a molded body of synthetic resin.

  The cylinder head 1 and the intake manifold 2 are fastened together by fastening along the fastening direction 7 of the bolt shown in FIG. The fastening direction 7 indicated by the one-dot chain line in FIG. 2 does not indicate the fastening position of the bolt, but is a gasket interposed between the combined surfaces 1a and 2a of the cylinder head 1 and the intake manifold 2 and the combined surfaces 1a and 2a. 3 is shown for convenience in order to show the relative inclination state of 3. That is, the part (equivalent to the part shown as FIG. 3) of the gasket 3 corresponding to the cross section taken along line XX in FIG. 1 is shown in FIG. 2 between the combined surfaces 1a and 2a of the cylinder head 1 and the intake manifold 2. It is interposed in such a state. In such a state, when fastening is performed so that the combined surfaces 1a and 2a reach the two-dot chain line position shown in FIG. 2 by the bolts along the fastening direction 7, the gasket bodies 5 and 6 are moved along the fastening direction 7. The fastening direction 7 and the plate surface direction 4c of the core substrate 4 try to fall down to the side where the fastening direction 7 and the plate surface direction 4c form an obtuse angle with respect to the portions located at the uppermost side portion and the lowermost side portion in the inclined direction. Force acts.

Thus, the gasket main bodies 5 and 6 have an obtuse angle between the fastening direction 7 by the fastening member and the plate surface direction 4c of the core substrate 4 at the portions located in the uppermost part and the lowermost part in the inclined direction. The slopes 5a0, 5b0, 6a0, 6b0 located on the forming side have a mountain-shaped cross section that is gentler than the slopes 5b1, 5a1, 6b1, 6a1 located on the side forming the acute angle. That is, in the part located in the most upstream side portion and the most downstream side portion in the inclined direction, the vertical lines 5c and 6c (see FIG. 3) from the apexes of the gasket bodies 5 and 6 to the core substrate 4 are gentle. The inclined slope portions 5a0, 5b0, 6a0, 6b0 are formed thicker than the steep inclined slope portions 5b1, 5a1, 6b1, 6a1. Therefore, the drag force on the side of the slopes 5a0, 5b0, 6a0, 6b0 is large against the fastening pressure accompanying the fastening, so that the gasket bodies 5, 6 have a fastening direction 7 and a plate surface direction 4c of the core substrate 4. 2 does not fall down to the obtuse angle side, and is compressed in a state in which the surface pressure with the combined surfaces 1a and 2a is sufficiently obtained as shown by the two-dot chain line in FIG. Therefore, the sealing performance at this portion is sufficiently ensured.
The rising angles of the inclined surface portions 5a0, 5b0, 6a0, 6b0 positioned on the obtuse angle side and the inclined surface portions 5b1, 5a1, 6b1, 6a1 positioned on the acute angle side with respect to the core substrate 4 are the gasket body. It is appropriately set in consideration of the size of 5, 6 and the inclination angle of the combined surfaces 1a, 2a with respect to the fastening direction 7.

  4 is a cross-sectional view taken along line YY in FIG. 1 and shows a cross-sectional shape of the annular gasket main bodies 5 and 6 in the gasket 3 at the intermediate portion in the inclined direction. As described above, in the middle portion of the inclination direction of the gasket bodies 5 and 6, the bolt fastening direction 7 (not shown in FIG. 4) is along the perpendiculars 5c and 6c when viewed in the width direction of the gasket bodies 5 and 6. Direction. Accordingly, in this portion, the fastening pressure by the bolts acts uniformly in the width direction of the gasket bodies 5 and 6, so the gasket bodies 5 and 6 in this portion are substantially lines centered on the perpendiculars 5 c and 6 c. It has a symmetric cross-sectional shape. That is, the inclination angles of the pair of inclined surfaces 5a, 5b and 6a, 6b of the gasket bodies 5, 6 at the intermediate portion are substantially the same. And since each inner peripheral side slope part 5a, 6a and outer peripheral side slope part 5b, 6b of the gasket main bodies 5 and 6 are formed so that it may become a continuous surface along the circumferential direction, the slope part in this intermediate part 5a, 5b and 6a, 6b are the abbreviations of the gentle slopes 5a0, 5b0, 6a0, 6b0 and the steep slopes 5b1, 5a1, 6b1, 6a1 in the uppermost part and the lowermost part. It is formed so as to form an intermediate inclination angle. Thus, by making the cross-sectional shape of the gasket bodies 5 and 6 in the intermediate portion into a substantially line-symmetrical mountain shape, the fastening pressure by the bolts acts uniformly in the width direction of the gasket bodies 5 and 6. Good surface pressure with the combined surfaces 1a and 2a (see FIG. 2) at the portion is ensured.

  As described above, the inner peripheral slopes 5a and 6a and the outer peripheral slopes 5b and 6b of the gasket bodies 5 and 6 are formed as continuous surfaces. The cross-sectional shape in the portion between the positions shown in FIG. 4 is the non-linearity in the portion located in the uppermost portion and the lowermost portion in the tilt direction from the line-symmetrical chevron shape portion in the portion located in the middle portion in the tilt direction It is made into the shape which changes continuously to a symmetrical chevron shape part. Between the part located in the intermediate part and the part located in the uppermost part and the lowermost part, the direction in which the fastening pressure acts on the width direction of the gasket bodies 5 and 6 at the time of fastening with the bolt is continuous. However, the cross-sectional shape is formed so as to continuously change along the circumferential direction between the portion located in the intermediate portion and the portions located in the uppermost side and the lowermost side portion. By adopting such a configuration, the drag force of the gasket bodies 5 and 6 also changes in accordance with the change in the fastening pressure, and the fall deformation over the entire circumference is more effectively prevented. The intake manifold 2 is made of a synthetic resin molded body, and the gasket bodies 5 and 6 are made of a rubber molded body, and are interposed between the combined surfaces 1a and 2a with a uniform surface pressure along the circumferential direction. This prevents the intake manifold 2 from being deformed.

  In the above embodiment, the example in which the gasket 3 of the present invention is applied to the joint portion between the cylinder head 1 of the engine and the intake manifold 2 is described. However, the present invention is not limited to this, and the combined surface is orthogonal to the fastening direction. If it is two members which are inclined without doing, the gasket of the present invention is preferably adopted. Further, the planar shape of the gasket 3 is not limited to the shape corresponding to the case where three seal target parts are arranged in parallel as shown in FIG. 1, and is formed individually for each seal target part. good. Furthermore, in the said embodiment, although the example applied between two metal-made and synthetic resin members was described, it is possible to apply to the joint part between metal members or between synthetic resin members. It is. Furthermore, the cross-sectional shape of the gaskets 5 and 6 is not limited to the chevron shape as shown in the figure, and other chevron shapes can be appropriately adopted as design matters. In addition, the gaskets 5 and 6 are formed so as to be connected to both surfaces of the core substrate 4 so as to cover the outer peripheral edge of the core substrate 4, the inner peripheral edge of the through hole 4a, and further the inner peripheral edge of the bolt insertion hole 4b. May be. In the illustrated example, such a connection portion is formed in part.

1 Cylinder head (one of two members)
1a Combined surface 1b Space to be sealed 2 Intake manifold (the other of the two members)
2a Combined surface 2b Space to be sealed 3 Gasket 4 Core substrate 4c Plate surface direction 5,6 Gasket body 5a, 5b Slope portion 6a, 6b Slope portion 5a0, 5b0 Slope portion 6a0, 6b0 Obtuse angle side Slope portion 5a1, 5b1 Slope portion on the acute angle side 6a1, 6b1 Slope portion on the acute angle side 7 Fastening direction

Claims (5)

The union surface around the space to be sealed in the two members tightened and joined by the fastening member is a gasket interposed between the union surfaces inclined without being orthogonal to the fastening direction by the fastening member,
It consists of a core substrate and an annular gasket body having an angled cross section made of an elastic body fixed and integrated on both surfaces of the core substrate,
The gasket main body has an obtuse angle between the fastening direction by the fastening member and the plate surface direction of the core substrate at a portion located on the uppermost side and the lowermost side of the combined direction around the space to be sealed. The rising angle of the slope portion positioned on the side with respect to the plate surface of the core substrate is a mountain-shaped cross-sectional shape that is smaller than the rising angle of the slope portion positioned on the side forming the acute angle with respect to the plate surface of the core substrate . A gasket characterized by. The gasket according to claim 1,
In the gasket body, the cross-sectional shape of the portion located in the intermediate portion in the inclined direction is a substantially line-symmetrical mountain shape, the portion located in the intermediate portion, the portion located in the uppermost side and the lowermost side portion, The gasket is characterized in that the cross-sectional shape is continuously changed along the circumferential direction. The gasket according to claim 1 or 2,
The gasket main body is formed of a rubber molded body. The gasket according to any one of claims 1 to 3,
The gasket characterized in that the two members are a cylinder head and an intake manifold of an internal combustion engine. The gasket according to claim 4,
The gasket is characterized in that the cylinder head is made of metal and the intake manifold is made of synthetic resin.

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