JP2011047508A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket improving sealability. <P>SOLUTION: In the gasket 10 wherein at least a body portion is composed of a metal plate, a bead 30 includes a first area 31 contacting in one point with respect to a cover and contacting in two points with respect to a housing, and a second area 32 contacting in two points with respect to the cover and contacting in three points with respect to the housing in a cross section perpendicular to a longitudinal direction of the gasket 10 in a held state of the gasket 10 between the housing and the cover. The first area 31 is provided near each through-hole 20 respectively inserted with a bolt, and the second area 32 is provided in a position separated away from each through-hole 20. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a gasket having at least a main body portion made of a metal plate.

  2. Description of the Related Art Conventionally, as a gasket for sealing a gap between two members, a gasket having a main body portion made of a metal plate is known. Such a conventional gasket will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view showing a state where a gasket according to a conventional example is sandwiched between two members. In addition, in FIG. 7, sectional drawing cut | disconnected perpendicularly | vertically to the longitudinal direction of the gasket is shown.

  The gasket 100 according to the conventional example is sandwiched between the housing 50 and the cover 60, thereby sealing a gap between the housing 50 and the cover 60. In the gasket 100 configured as described above, the main body portion is configured by a metal plate, and as a characteristic thereof, there is an advantage that plastic processing can be performed. Therefore, in such a gasket 100, generally, a bead 101 is formed along the longitudinal direction of the gasket 100, and the sealing performance is enhanced.

  That is, when the bead 101 is formed, the three corners of the bead 101 come into contact with the housing 50 and the cover 60 when sandwiched between the housing 50 and the cover 60. Therefore, since the contact pressure is concentrated in the vicinity of the contact portion, it is possible to improve the sealing performance as compared with the case where the gasket is planarly contacted with the housing 50 and the cover 60 without providing the bead 101.

  However, when the housing 50 or the cover 60 is die-cast, a cast hole can be formed on the surface. In the example shown in FIG. 7, a case where a cast hole Z is formed on the surface of the housing 50 is shown. As in the example shown in FIG. 7, if the casting hole Z happens to be formed at a position where the corner portion of the bead 101 contacts the housing 50, a gap is formed between the corner portion and the casting hole Z. This will cause the sealing performance to deteriorate.

Japanese Patent Laid-Open No. 62-261755 Utility Model Registration No. 2589387

  An object of the present invention is to provide a gasket having improved sealing performance.

  The present invention employs the following means in order to solve the above problems.

That is, the gasket of the present invention is
A gasket that is sandwiched between two members fixed to each other by a plurality of bolts and seals a gap between the two members,
A gasket having a bead provided along the longitudinal direction of the gasket and a plurality of insertion holes through which the plurality of bolts are respectively inserted, and at least a main body portion is made of a metal plate (even if it is made only of a metal plate) Or the surface of the metal plate may be covered with an elastic body or the like)
The bead is
In a state in which the gasket is sandwiched between the two members, the first member is in contact with one member of the two members at one location and in contact with the other member at two locations in a cross section perpendicular to the longitudinal direction of the gasket. Area,
In a state in which the gasket is sandwiched between the two members, a second portion that is in contact with one member of the two members at two locations and is in contact with the other member at three locations in a cross section perpendicular to the longitudinal direction of the gasket. An area, and
A first region is provided in the vicinity of each insertion hole, and a second region is provided at a position away from each insertion hole.

  According to the present invention configured as described above, in the vicinity of the insertion hole through which the bolt is inserted, the bead is 1 in one of the two members in a cross section perpendicular to the longitudinal direction of the gasket. It touches at a place and touches the other member at two places. Thereby, in the vicinity of the insertion hole, it is possible to suppress a decrease in the contact pressure with respect to the two members of the bead over time. Therefore, it is possible to suppress a decrease in axial force with time in the shaft portion of the bolt.

  Further, by being away from the insertion hole through which the bolt is inserted, at a position where the clamping force by the two members is low, the bead is in a cross section perpendicular to the longitudinal direction of the gasket with respect to one of the two members. It touches at two places, and touches the other member at three places. Thereby, even if the location where contact is insufficient between a bead and two members arises, the fall of a sealing performance can be suppressed.

  Also, there are few bead contact points in the vicinity of the insertion hole through which the bolt is inserted (the position where the pinching force by the two members is large), and there is a bead contact point at a position away from the insertion hole (the position where the pinching force by the two members is small). Is configured to increase. Therefore, variation in contact pressure (surface pressure) with respect to the two members of the beads can be suppressed, and stable sealing performance can be obtained.

  The bead may be provided so as to pass through the sealed region side with respect to the plurality of insertion holes.

  Thereby, it can prevent that a bead becomes non-contact with respect to two members in the outer side (opposite side of a sealing area | region) of an insertion hole.

  As described above, according to the present invention, the sealing performance can be improved.

FIG. 1 is a schematic plan view of a gasket according to an embodiment of the present invention. FIG. 2 is a schematic view (part of a view seen from the side) showing a state before the gasket according to the embodiment of the present invention is assembled. FIG. 3 is a schematic cross-sectional view (AA cross-sectional view in FIG. 1) of the gasket according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a state in which a gasket (corresponding to the AA cross section in FIG. 1) according to the embodiment of the present invention is sandwiched between two members. FIG. 5 is a schematic cross-sectional view (BB cross-sectional view in FIG. 1) of the gasket according to the embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a state in which a gasket according to an embodiment of the present invention (corresponding to the BB cross section in FIG. 1) is sandwiched between two members. FIG. 7 is a schematic cross-sectional view showing a state where a gasket according to a conventional example is sandwiched between two members. FIG. 8 is a schematic cross-sectional view showing a state in which the gasket according to the base technology in the embodiment of the present invention is sandwiched between two members.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the following examples are not intended to limit the scope of the present invention to those unless otherwise specified. Absent.

  The gasket which concerns on the Example of this invention is provided in order to seal the clearance gap between two members. More specifically, the present invention can be suitably applied when the two members are die-cast, such as a mission case and a hybrid vehicle inverter case.

  As explained in the background art, by providing a bead, it is possible to enhance the sealing performance by concentrating the contact pressure, but if there is a cast hole at the corner of the bead, the sealing performance is reduced. End up.

  Therefore, it is conceivable to suppress a decrease in sealing performance by increasing the number of contact locations. Hereinafter, the technology which is a premise in the gasket according to the embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view showing a state in which the gasket according to the base technology in the embodiment of the present invention is sandwiched between two members. In this gasket 110, the lateral width of the top portion on the protruding side of the bead 111 is increased. Thus, when the gasket 110 is sandwiched between the housing 50 and the cover 60, the top portion is greatly deformed, and the beads 111 are in contact with the housing 50 and the cover 60 at five locations. Therefore, even if there is a cast hole Z at a position where the bead 111 should come into contact and leakage occurs at one place, the sealing performance is maintained if it is sealed at another place.

  In the example shown in FIG. 8, the cast holes Z are formed on the surfaces of the housing 50 and the cover 60, respectively. Thereby, with respect to the housing 50, the gasket 110 should be sealed at three places, but a gap is generated between the bead 111 and the cast hole Z at one place on the right side in the drawing. However, since sealing is performed at two places in the center and the left side in the figure, the sealing performance is not affected.

  As described above, it is possible to suppress the deterioration of the sealing performance due to the cast hole Z as the number of contact portions of the beads with the housing 50 and the cover 60 is increased.

  However, when the gap between the housing 50 and the cover 60 is sealed, it may not always be sufficient when the sealing structure having the five contact portions as described above is adopted in all regions. This point will be described below.

  Since the clamping load between the housing 50 and the cover 60 is determined by the bolt axial force and is constant, the amount of bead compression decreases as the number of contact points increases. For this reason, as the number of contact points is increased, the temporal decrease in the contact pressure with respect to the housing 50 and the cover 60 becomes more significant. That is, since the housing 50 and the cover 60 are thermally expanded and contracted due to the change in the environmental temperature, the gap between the housing 50 and the cover 60 changes. As a result, the beads in the gasket are also repeatedly deformed, and the beads gradually sag due to deterioration over time. In this way, as the settling of the beads progresses, the contact pressure of the gasket with respect to the housing 50 and the cover 60 decreases significantly as the bead compression amount (compression ratio) decreases.

  And when the contact pressure with respect to the housing 50 and the cover 60 of a gasket falls and the fastening part by a bolt exists in the vicinity, the force (tensile force) given to an axial direction with respect to the axial part of a bolt falls. Resulting in. That is, there arises a problem that the axial force of the bolt decreases. Thereby, sealing performance will fall or a bolt will loosen and fastening force may fall further.

  Therefore, increasing the number of contact points as described above in the vicinity of the fastening portion by the bolt may rather cause a decrease in sealing performance. Therefore, as described below, in the gasket according to the embodiment of the present invention, the sealing performance is improved while the fastening force by the bolt is stabilized.

(Example)
With reference to FIGS. 1-6, the gasket which concerns on the Example of this invention is demonstrated.

<Overall configuration>
An overall configuration of the gasket according to the embodiment of the present invention will be described. The gasket 10 according to the present embodiment is provided to seal a gap between the inner hollow housing 50 and a cover 60 for closing an opening formed in the housing 50. Both the housing 50 and the cover 60 are die-cast. The cover 60 corresponds to one member of the two members, and the housing 50 corresponds to the other member of the two members.

  The main part of the gasket 10 is composed of a metal plate (steel plate) 11. More specifically, for example, it is made of cold rolled steel or stainless steel. And both surfaces of this metal plate 11 are covered with rubber layers 12 and 13 which are elastic bodies, respectively. It is also preferable to coat the surfaces of these rubber layers 12 and 13 with a coating agent according to a desired function.

  The housing 50 and the cover 60 are configured to be fixed by fastening a plurality of (six in this embodiment) bolts 70. The gasket 10 is provided with a plurality (six in this embodiment) of insertion holes 20 through which a plurality of bolts 70 (shaft portions thereof) are respectively inserted. The gasket 10 is provided with a bead 30 along the longitudinal direction thereof. The bead 30 is provided so as to pass through the sealed region side (inside) with respect to the plurality of insertion holes 20 (see FIG. 1). The bead 30 is obtained by embossing the metal plate 11 into an embossed shape.

  And the bead 30 concerning a present Example differs in a structure by the position. Specifically, it has two types of structures. Hereinafter, the bead 30 will be described in more detail.

<Bead>
The bead 30 according to the present embodiment is configured by a convex portion that protrudes to one side (in the present embodiment, the cover 60 side) over the entire area in a state where no external force is applied. Two types of structures are provided so that the action when sandwiched by the cover 60 is different. That is, the structure differs between the vicinity of the insertion hole 20 and the position away from the insertion hole 20. More specifically, in FIG. 1, the bead 30 has a different structure in a first region 31 indicated by a dotted line and a second region 32 indicated by a thick line.

In the 1st field 31, it is constituted so that the width of the peak part by the side of the projection in bead 30 may become narrow (refer to Drawing 3). Accordingly, the bead 3 is formed by the housing 50 and the cover 60.
When 0 is sandwiched, the top portion is not greatly deformed. Therefore, the bead 30 is in contact with the cover 60 at one position (X1 in FIG. 4) in the cross section perpendicular to the longitudinal direction of the gasket 10 in a state where the gasket 10 is sandwiched between the housing 50 and the cover 60. Is contacted at two locations (X2 and X3 in FIG. 4). That is, the top portion (X 1) of the bead 30 is in contact with the cover 60, and the lower ends (X 2, X 3) on both sides in the width direction of the bead 30 are in contact with the housing 50.

  In 2nd area | region 32, it is comprised so that the width | variety of the top part by the side of the protrusion in bead 30 may become large (refer FIG. 5). Accordingly, when the bead 30 is sandwiched between the housing 50 and the cover 60, the top portion is greatly deformed. Therefore, the bead 30 is in contact with the cover 60 at two locations (Y1, Y2 in FIG. 6) in a cross section perpendicular to the longitudinal direction of the gasket 10 in a state where the gasket 10 is sandwiched between the housing 50 and the cover 60. It contacts the housing 50 at three locations (Y3, Y4, Y5 in FIG. 6). That is, both ends (Y1, Y2) in the width direction of the top portion of the bead 30 are in contact with the cover 60, and the top portion is deformed so that the vicinity of the center is directed to the housing 50 side. Thus, the lower end (Y3, Y5) on both sides in the width direction of the bead 30 and the portion (Y4) corresponding to the back side near the center of the top portion in a state where no external force is received contact the housing 50.

<Excellent point of gasket according to this example>
As described above, according to the gasket 10 according to the present embodiment, in the vicinity of the insertion hole 20 through which the bolt 70 is inserted, the bead 30 is in a cross section perpendicular to the longitudinal direction of the gasket 10 with respect to the cover 60. It contacts at one location and contacts the housing 50 at two locations. Thereby, in the vicinity of the insertion hole 20, it is possible to suppress a temporal decrease in the contact pressure of the bead 30 with respect to the cover 60 and the housing 50. Thereby, the time-dependent fall of the axial force in the axial part of the volt | bolt 70 can be suppressed. Therefore, a decrease in fastening force due to loosening of the bolt 70 can be suppressed. In addition, it is as having demonstrated in the base technology in the Example of this invention that the time-dependent fall of a contact pressure can be suppressed by reducing the contact location with respect to the cover 60 and the housing 50 of the bead 30. FIG.

  Further, since the bolt 70 is separated from the insertion hole 20 through which the bolt 70 is inserted, the bead 30 is formed on the cover 60 in a cross section perpendicular to the longitudinal direction of the gasket 10 at a position where the clamping force between the housing 50 and the cover 60 is low. The contact is made at two locations, and the housing 50 is contacted at three locations. Thereby, even if the location where the contact is insufficient between the bead 30 and the housing 50 or the cover 60 occurs due to a cast hole or the like, it is possible to suppress a decrease in sealing performance. In addition, it is as having demonstrated in the premise technique in the Example of this invention that the fall of a sealing performance can be suppressed by increasing the contact location with respect to the cover 60 and the housing 50 of the bead 30. FIG.

  Further, in the vicinity of the insertion hole 20 through which the bolt 70 is inserted (a position where the clamping force between the housing 50 and the cover 60 is large), the contact position of the bead 30 is small and a position away from the insertion hole 20 (the clamping between the housing 50 and the cover 60). The position where the force is small) is configured so that the number of contact points of the beads 30 increases. Therefore, variation in contact pressure (surface pressure) with respect to the housing 50 and the cover 60 of the bead 30 can be suppressed, and stable sealing performance can be obtained.

  Furthermore, in this embodiment, the bead 30 is configured to pass through the sealed region side (inside) with respect to the plurality of insertion holes 20. Therefore, the bead 30 can be prevented from coming out of contact with the housing 50 and the cover 60 outside the insertion hole 20 (on the side opposite to the sealed region).

DESCRIPTION OF SYMBOLS 10 Gasket 11 Metal plate 12, 13 Rubber layer 20 Insertion hole 30 Bead 31 1st area | region 32 2nd area | region 50 Housing 60 Cover 70 Bolt

Claims (2)

A gasket that is sandwiched between two members fixed to each other by a plurality of bolts and seals a gap between the two members,
In the gasket comprising a bead provided along the longitudinal direction of the gasket and a plurality of insertion holes through which the plurality of bolts are respectively inserted, and at least a main body portion is formed of a metal plate,
The bead is
In a state in which the gasket is sandwiched between the two members, the first member is in contact with one member of the two members at one location and in contact with the other member at two locations in a cross section perpendicular to the longitudinal direction of the gasket. Area,
In a state in which the gasket is sandwiched between the two members, a second portion that is in contact with one member of the two members at two locations and is in contact with the other member at three locations in a cross section perpendicular to the longitudinal direction of the gasket. An area, and
The gasket characterized by the 1st area | region being provided in the vicinity of each insertion hole, and the 2nd area | region being provided in the position away from each insertion hole.   The gasket according to claim 1, wherein the bead is provided so as to pass through the sealed region side with respect to the plurality of insertion holes.

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