Gasket

Abstract

To provide a gasket capable of suppressing tilting of a main body part.SOLUTION: A gasket 10 comprises: a body part 11 that is inserted into a mounting groove 3 provided in a first member 1, and is compressed by a groove bottom 4 of the mounting groove and an opposite surface 9 of a second member 8 facing the groove bottom to seal between the first member and the second member; and protrusion parts 18 each of which is provided to protrude in a groove width direction from a first side surface 16A of the body part on the groove bottom side and on at least one side in the groove width direction, and which is bent toward a groove opening 3a side in the state that the body part is inserted into the mounting groove, is interposed between the first side surface and a groove wall 5 of the mounting groove and abuts against the groove wall to avoid contact between the first side surface and the groove wall.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gasket. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a gasket has been known that is inserted into a mounting groove provided in a first member to provide a seal between the first member and a second member. For example, Patent Document 1 below discloses a gasket that is provided with a gasket body and protrusions on both sides extending obliquely downward from both sides of the gasket body, and is pressed into a gasket fitting groove. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-156840 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the gasket described in Patent Document 1, the protrusions on both sides protrude from the middle of the gasket body in the groove depth direction, so there is a concern that the gasket body may be easily tilted when the gasket body inserted into the gasket fitting groove is compressed. If the gasket body is tilted in this way, the side surface of the end portion on the bottom side of the groove may come into contact with and stick to the groove wall, resulting in a decrease in sealing performance.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a gasket that can suppress contact between a main body portion and a groove wall. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the gasket of the present invention is characterized in that it comprises a main body portion that is inserted into a mounting groove provided in a first member and is compressed by the groove bottom of the mounting groove and the opposing surface of a second member facing it to seal between the first member and the second member, and a protrusion that is provided to protrude in the groove width direction from a first side surface on at least one side in the groove width direction of the groove bottom side of the main body portion, and is bent toward the groove opening side when the main body portion is inserted into the mounting groove, so as to avoid contact between the first side surface and the groove wall of the mounting groove and to abut against the groove wall.

[0007] In the above gasket, a protruding dimension along a groove width direction of the protruding portion in a natural state before being inserted into the mounting groove may be equal to or greater than half a groove depth dimension of the mounting groove. In the gasket, the protruding portion may be provided with an abutment portion that protrudes in a groove width direction and abuts against the groove wall when the main body is inserted into the mounting groove. In the gasket, the protruding portion may be provided with an abutment portion that protrudes in a groove width direction and abuts against the first side surface when the main body is inserted into the mounting groove. In addition, in the above gasket, the main body portion may have a straight portion that is inserted into a straight groove portion that is formed in a straight line in the mounting groove, and the protrusions may be provided on both side surfaces of the straight portion on the groove bottom side in the groove width direction. Furthermore, in the above gasket, the main body portion may have a curved portion that is inserted into a curved groove portion formed in a curved shape in the mounting groove, and the protrusion may be provided on the first side surface of the convex side that is on one side in the groove width direction of the curved portion, and the main body portion may abut against the first side surface and a groove wall of the mounting groove when inserted and compressed into the mounting groove. In the gasket, the protruding portion may be elongated in a protruding direction, and a side surface that abuts against the groove wall may be curved in a cross section perpendicular to the longitudinal direction. In addition, in the above gasket, the protrusion includes a first protrusion provided on the first side surface and a second protrusion provided on a second side surface on the concave side, which is the other side in the groove width direction of the curved portion, and the protrusion dimension of the second protrusion along the groove width direction in its natural state before insertion into the mounting groove may be smaller than the protrusion dimension of the first protrusion along the groove width direction. Effect of the Invention

[0008] Since the gasket of the present invention has the above-mentioned configuration, it is possible to suppress contact between the main body portion and the groove wall. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2(a) is a schematic plan view of a gasket according to a first embodiment, and FIG. 2(b) is a cross-sectional view taken along line XX in FIG. [Diagram 2] 3A is a schematic vertical cross-sectional view showing the gasket inserted into a groove, and FIG. 3B is a schematic vertical cross-sectional view showing the gasket compressed. [Diagram 3] 5(a) and 5(b) are schematic vertical cross-sectional views showing modified examples of the protruding portion of the gasket of the first embodiment. [Figure 4] FIG. 6(a) is a schematic plan view showing a part of a gasket according to a second embodiment, and (b) is a schematic perspective view of (a). [Diagram 5] 3A is a schematic vertical cross-sectional view showing the gasket inserted into a groove, and FIG. 3B is a schematic vertical cross-sectional view showing the gasket compressed. [Figure 6] 13(a) is a schematic plan view showing a part of a gasket according to a modified example of the second embodiment, and (b) is a cross-sectional view taken along line YY in (a). FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, gaskets according to various embodiments will be described with reference to the drawings. Note that in some drawings, some of the detailed reference numerals used in other drawings are omitted.

[0011] 1 to 3 show an example and a modified example of the gasket according to the first embodiment. The gasket 10 according to this embodiment includes a main body 11 that is inserted into a mounting groove 3 provided in a first member 1 and is compressed by a groove bottom 4 of the mounting groove 3 and an opposing surface 9 of a second member 8 that faces the groove bottom 4, thereby sealing between the first member 1 and the second member 8. With this configuration, the main body 11 can seal between the first member 1 and the second member 8. The gasket 10 is provided with a protruding portion 18 that is provided to protrude in the groove width direction from at least one first side surface 16A on the groove bottom 4 side of the main body 11, and is bent toward the groove opening 3a when the main body 11 is inserted into the mounting groove 3, and is interposed between the first side surface 16A and the groove wall 5 of the mounting groove 3 to avoid contact between them and abut against the groove wall 5. With this configuration, the protruding portion 18 bent toward the groove opening 3a enters the gap between the first side surface 16A and the groove wall 5 of the mounting groove 3, and can suppress contact between the main body 11 and the groove wall 5. This makes it possible to suppress the first side surface 16A of the main body 11 from sticking to the groove wall 5 of the mounting groove 3, and makes the main body 11 more likely to deform in response to changes in size between the first member 1 and the second member 8 or changes in temperature, and also prevents settling, thereby suppressing deterioration of sealing performance. The details are explained below.

[0012] The first member 1 and the second member 8 sealed by the gasket 10 may be, for example, two opposing members among a head cover, a cylinder head, a cylinder block, an oil pan, and a chain cover that constitute an automobile engine, or may be two other members. The first member 1 and the second member 8 may be fastened in a direction along the groove depth direction of the mounting groove 3 by a bolt inserted into an insertion hole or a female screw hole provided in each member. The first member 1 and the second member 8 are provided on their peripheral portions with opposing surfaces 2, 9 that face each other approximately parallel to each other over the entire circumference. The opposing surface 2 of the first member 1 is provided with a concave mounting groove 3 formed along the entire circumference of the peripheral portion of the first member 1. As shown in Fig. 1(a), the mounting groove 3 is provided in a rectangular ring shape with rounded corners, and includes a straight groove portion 6 formed in a straight line and a curved groove portion 7 formed in a curved shape. As shown in Fig. 1(b), the mounting groove 3 is in a substantially rectangular groove shape. A groove opening 3a of this mounting groove 3 opens to the second member 8 side. This mounting groove 3 is defined by groove walls 5, 5 that are substantially perpendicular to the opposing surface 2 and define both sides in the groove width direction, and a groove bottom 4 that is substantially parallel to the opposing surface 2 and defines the groove bottom side.

[0013] The gasket 10 is integrally formed from a rubber material, and such a rubber material may be, for example, EPDM, NBR, H-NBR, ACM, AEM, FKM, or the like. As shown in FIG. 1(a), the main body 11 is formed in a rectangular ring shape with rounded corners corresponding to the ring-shaped mounting groove 3 into which it is fitted. The main body 11 has a straight portion 12 to be inserted into the straight groove portion 6 of the mounting groove 3. The main body 11 has a curved portion 13 to be inserted into the curved groove portion 7 of the mounting groove 3. If the mounting groove 3 is not formed in a ring shape, the main body 11 is formed in a shape corresponding to the mounting groove 3. As shown in FIG. 1(b), in a natural state before being inserted into the mounting groove 3 (not inserted into the mounting groove 3), the cross-sectional shape of the main body 11 cut along the groove width direction is elongated along the groove depth direction. The main body 11 is formed so that the dimension along the groove depth direction is larger than the groove depth dimension of the mounting groove 3, and the dimension along the groove width direction is smaller than the groove width dimension of the mounting groove 3.

[0014] The main body 11 has a bottom side surface 14 which is a flat surface that abuts against the groove bottom 4 of the mounting groove 3 and is approximately parallel to the groove bottom 4, and an opening side surface 15 which abuts against the opposing surface 9 of the second member 8 and is approximately parallel to the opposing surface 9. FIG. 1(b) shows an example in which both sides of the bottom side surface 14 and the opening side surface 15 in the groove width direction are chamfered. The main body 11 has a first side surface 16A which faces the groove wall 5 on one side of the mounting groove 3 in the groove width direction, and a second side surface 16B which faces the groove wall 5 on the other side of the mounting groove 3 in the groove width direction. In the example of FIG. 1(b), the outer circumferential side of the main body 11 is the first side surface 16A, and the inner circumferential side of the main body 11 is the second side surface 16B. 1(b), the dimension of the groove bottom 4 side portion of the body 11 along the groove width direction is smaller than the dimension of the groove opening 3a side portion of the body 11 along the groove width direction, and steps 16a, 16a are formed in the middle of the first side 16A and the second side 16B in the groove depth direction due to the difference in dimensions. The steps 16a, 16a on both sides in the groove width direction make the dimension of the bottom side 14 along the groove width direction smaller than the dimension of the opening side 15 along the groove width direction.

[0015] The protrusions 18 are provided on both side surfaces 16A, 16B of the straight portion 12 of the main body 11 on the side of the groove bottom 4. With this configuration, it is possible to prevent the both side surfaces 16A, 16B of the straight portion 12 of the main body 11 from contacting the groove walls 5, 5 on both sides of the straight groove portion 6, and it is also possible to effectively prevent the main body 11 from tilting in the straight groove portion 6 of the mounting groove 3. The protrusions 18 are formed at intervals along the longitudinal direction of the straight portion 12 (the circumferential direction of the gasket 10). These multiple protrusions 18 may be provided at appropriate intervals so as to prevent contact of the main body 11 with the groove wall 5 between the protrusions 18, 18 adjacent in the longitudinal direction. In addition, the dimension of the protrusions 18 along the longitudinal direction of the straight portion 12 may be an appropriate dimension so as to cooperate with other protrusions 18 adjacent in the longitudinal direction to prevent contact of the main body 11 with the groove wall 5 between the protrusions 18, 18. In the illustrated example, the dimension of the protrusion 18 along the longitudinal direction of the straight portion 12 is configured to be equal to or greater than the protrusion dimension along the groove width direction. The protrusions 18, 18 formed on both side surfaces 16A, 16B of the main body 11 are formed symmetrically at approximately the same position in the longitudinal direction of the straight portion 12. FIG. 1(a) shows an example in which three pairs of protrusions 18, 18 are formed on each of the two straight portions 12 on the long side, and two pairs of protrusions 18, 18 are formed on each of the two straight portions 12 on the short side. Note that FIG. 1(a) shows an example in which no protrusions 18 are formed on the curved portion 13. Even in this configuration, the inclination of the curved portion 13 is regulated by the protrusions 18, 18 of the straight portions 12, 12 adjacent to both sides of the curved portion 13 in the circumferential direction.

[0016] Since the protrusions 18, 18 of the first side 16A and the second side 16B have the same configuration, in the following explanation, unless a distinction is necessary, one side will be used as an example, and the first side 16A and the second side 16B will also be explained as side 16. As shown in Fig. 1(a)(b), the protruding portion 18 may be formed in a thin plate shape whose thickness direction is the groove depth direction in a natural state (when not inserted into the mounting groove 3). In a natural state, the protruding portion 18 is formed so as to protrude substantially perpendicularly from the side surface 16 of the main body portion 11 and substantially parallel to the groove width direction. The protruding portion 18 protrudes from a portion on the side surface 16 of the main body portion 11 that is closer to the groove bottom 4 side than the center in the groove depth direction. The protruding portion 18 may protrude from a portion on the side surface 16 that is within a range of 1 / 3 of the dimension of the side surface 16 from the bottom surface 14 along the groove depth direction. In the illustrated example, the protruding portion 18 protrudes from a portion on the side surface 16 that is within a range of 1 / 4 of the dimension of the side surface 16 from the bottom surface 14 along the groove depth direction.

[0017] The protruding dimension w1 of the protruding portion 18 in the groove width direction in the natural state (the dimension in the groove width direction from the side surface 16 to the tip of the protruding portion 18 in the protruding direction) is formed to be 1 / 2 or more of the groove depth dimension d of the mounting groove 3. With this configuration, the protruding portion 18 inserted into the mounting groove 3 is interposed between the side surface 16 of the main body portion 11 and the groove wall 5 of the mounting groove 3 over most of the groove depth direction, so that contact of the main body portion 11 with the groove wall 5 can be more effectively suppressed. The protruding dimension w1 of the protruding portion 18 may be an appropriate dimension so that the protruding portion 18 can be interposed between the side surface 16 of the main body portion 11 and the groove wall 5 of the mounting groove 3 in a portion that is 1 / 2 or more of the groove depth dimension d of the mounting groove 3 when inserted into the mounting groove 3. In the illustrated example, the protruding dimension w1 of the protruding portion 18 in the natural state is 2 / 3 or more of the groove depth dimension d of the mounting groove 3. It is preferable that the protrusion dimension w1 of the protrusion 18 is configured so that, when inserted into the mounting groove 3, it fits within the mounting groove 3, as shown in Fig. 2(a). With such a configuration, it is possible to prevent the protrusion 18 from being caught between the opposing surfaces 2, 9 when the first member 1 and the second member 8 are fastened. In the illustrated example, the protrusion dimension w1 of the protrusion 18 is set to be 4 / 5 or more of the groove depth dimension d of the mounting groove 3 when the main body 11 is inserted into the mounting groove 3 and compressed.

[0018] The protruding portion 18 is provided with a contact portion 20 that protrudes in the groove width direction and abuts against the groove wall 5 when the main body portion 11 is inserted into the mounting groove 3. Since the portion of the protruding portion 18 that protrudes in the groove width direction is configured as the abutting portion 20 that abuts against the groove wall 5, the contact area between the protruding portion 18 and the groove wall 5 can be reduced. This can reduce the sticking of the protruding portion 18 to the groove wall 5 and also reduce the thermal effect from the groove wall 5 to the main body portion 11. The protruding portion 18 is provided with an abutting portion 21 that protrudes in the groove width direction and abuts against the side surface 16 of the main body portion 11 when the main body portion 11 is inserted into the mounting groove 3. In this manner, the portion of the protruding portion 18 that protrudes in the groove width direction is configured as the abutting portion 20 that abuts against the side surface 16, so that the abutting portion 21 abutting against the side surface 16 of the main body portion 11 can reduce the contact area between the protruding portion 18 and the side surface 16 of the main body portion 11. This makes it possible to reduce the thermal effect from the groove wall 5 to the main body portion 11. That is, in this embodiment, the protruding portion 18 is provided with both the abutting portion 20 that abuts against the groove wall 5 and the abutting portion 21 that abuts against the side surface 16 of the main body portion 11. Therefore, the thermal effect from the groove wall 5 to the main body portion 11 can be more effectively reduced. These abutment portions 20, 21 are provided on part of the bent portion 19 that is bent toward the groove opening 3a at the protrusion 18 when the main body portion 11 is inserted into the mounting groove 3, and in this state are at a different position (or a shifted position) in the groove depth direction from the base end portion 18b of the protrusion 18.

[0019] In this embodiment, the abutting portions 20, 21 are formed by bending the protruding portion 18 itself, which is formed in a thin plate shape, in the thickness direction. The abutting portions 20, 21 are formed in a ridge shape extending along the longitudinal direction of the straight portion 12, and are provided over the entire protruding portion 18 in the longitudinal direction of the straight portion 12. The abutting portion 20 that abuts against the groove wall 5 is formed in a mountain shape so as to be convex toward the groove wall 5 side, and the abutting portion 21 that abuts against the side surface 16 is formed in a mountain shape so as to be convex toward the side surface 16 side. In the illustrated example, the abutting portion 20 that abuts against the groove wall 5 is provided at a position approximately at the center of the protruding portion 18 in the protruding direction, the abutting portion 21 that abuts against the side surface 16 is provided so as to be connected to the abutting portion 20, and the abutting portion 20 that abuts against the groove wall 5 is provided near the tip portion 18a of the protruding portion 18 so as to be connected to the abutting portion 21. That is, the illustrated example shows an example in which two abutting portions 20 that abut against the groove wall 5 and one abutting portion 21 that abuts against the side surface 16 are provided. Moreover, these abutting portions 20, 21 are provided offset from each other in the protruding direction of the protruding portion 18 so as to bend in opposite directions alternately, so that a so-called corrugated portion is formed in the protruding portion 18. The abutting portions 20, 21 corresponding to the tops of the corrugated portions abut against the groove wall 5 and the side surface 16, respectively, so that the contact area of ​​the protruding portion 18 can be reduced. Moreover, since these abutting portions 20, 21 are provided offset from each other in the protruding direction of the protruding portion 18, even if the abutting portion 20 sticks to the groove wall 5, it is possible to avoid (reduce) the influence on the main body portion 11. Moreover, the corrugated portion may be configured to deform so as to extend toward the groove opening 3a between the main body portion 11 and the groove wall 5 when the gasket 10 is inserted into the mounting groove 3 and compressed, as shown in FIG. 2(b), and to have a substantially flat surface shape.

[0020] When the gasket 10 is inserted into the mounting groove 3, the protrusion 18 is bent substantially vertically at the base end 18b, as shown in Fig. 2(a), and is aligned with the groove wall 5 so that the tip end 18a faces the groove opening 3a. When the gasket 10 is inserted into the mounting groove 3 and is not compressed, the abutment portion 20 facing the groove wall 5 abuts against the groove wall 5, and the abutment portion 21 facing the side surface 16 abuts against the side surface 16. In the illustrated example, the abutment portion 21 facing the side surface 16 faces a portion of the side surface 16 that is closer to the groove opening 3a than the step 16a when inserted into the mounting groove 3. When the gasket 10 inserted into the mounting groove 3 is compressed in the groove depth direction, the main body 11 is compressed in the groove depth direction and elastically deformed, as shown in Fig. 2(b), and the dimension of the main body 11 along the groove width direction increases. In this state, the bottom side surface 14 and the opening side surface 15 of the main body 11 are in close contact with the groove bottom 4 and the opposing surface 9 of the second member 8, respectively, and the protrusion 18 contacts the side surface 16 of the main body 11 and the groove wall 5. In this embodiment, the protrusion 18 contacts the side surface 16 of the main body 11 and the groove wall 5 with a partial gap between the protrusion 18 and the side surface 16 of the main body 11 and the groove wall 5, due to the abutment portion 20 abutting the groove wall 5 and the abutment portion 21 abutting the side surface 16 of the main body 11.

[0021] Next, modified examples of the gasket of this embodiment will be described with reference to Figures 3(a) and 3(b). In each of the following modified examples, differences from the previously described example will be mainly described, and descriptions of configurations and effects of parts common to the previously described example will be omitted.

[0022] 3(a) shows a gasket 10A according to a first modified example. In this modified example, the configuration of the contact portions 20A and 21A is different from that of the above-described example. In this modification, the contact portions 20A, 21A are provided on both sides of the protrusion 18A in the thickness direction so as to increase the thickness of a portion of the bent portion 19 of the protrusion 18A on which they are provided. In the illustrated example, the contact portion 20A that contacts the groove wall 5 and the contact portion 21A that contacts the side surface 16 are formed at the same position in the protrusion direction of the protrusion 18A, but this is not limited thereto, and they may be formed at different positions in the protrusion direction of the protrusion 18A. In addition, in the illustrated example, a plurality of contact portions 20A, 21A (three in the illustrated example) are provided at intervals in the protrusion direction of the protrusion 18A, but the number is not limited thereto. The contact portions 20A and 21A have a semicircular cross-sectional shape when cut along the groove width direction of the protrusion 18A. The contact portions 20A and 21A may be formed in a ridge shape extending along the longitudinal direction of the straight portion 12, or may be provided at multiple locations along the longitudinal direction of the straight portion 12 with intervals between them.

[0023] 3(b) shows a gasket 10B according to a second modified example. This modified example differs from the above-mentioned examples in that the protruding portion 18B does not have a contact portion that protrudes in the groove width direction and contacts the groove wall 5 when the gasket 10B is inserted into the mounting groove 3, but only has a contact portion 21B that contacts the side surface 16. The gasket 10B is configured such that the protruding portion 18B has a surface that faces and contacts the groove wall 5 when the gasket 10B is inserted into the mounting groove 3. The abutment portion 21B is provided only on the tip 18a of the protrusion 18B. As in the first modification, the abutment portion 21B protrudes from the protrusion 18B so as to increase the thickness of a portion of the bent portion 19 of the protrusion 18B where the abutment portion 21B is provided. With such a configuration, when the gasket 10B is arranged so that the bottom side surface 14 faces upward, the weight of the abutment portion 21B causes the protrusion 18B to bend so that the tip 18a of the protrusion 18B faces downward. This makes it easier to insert the gasket 10B into the mounting groove 3 that opens downward. In the illustrated example, the cross-sectional shape of the contact portion 21B cut along the groove width direction is formed into a substantially triangular shape tapering toward the groove opening 3a in the groove depth direction in the natural state of the protrusion 18B. The contact portion 21B may be formed into a ridge shape extending along the longitudinal direction of the straight portion 12, or may be provided at multiple locations spaced apart in the longitudinal direction of the straight portion 12.

[0024] Next, an example and a modified example of a gasket according to a second embodiment will be described with reference to Fig. 4 to Fig. 6. Note that in this embodiment, differences from the first embodiment will be mainly described, and a description of the configuration and effects of parts common to the first embodiment will be omitted. As shown in Figures 4(a) and 4(b), the gasket 10C according to this embodiment includes a main body portion 11A formed in a serpentine shape along the longitudinal direction. In this embodiment, the main body portion 11A is formed in a serpentine shape by combining straight portions 12 and curved portions 13. The straight portions 12 are provided with protrusions 18 similar to those in the above-mentioned example. In this embodiment, the curved portions 13 are also provided with protrusions 18C.

[0025] The protrusion 18C is provided on the side surface 16 of the convex side of the curved portion 13, which is at least one side in the groove width direction on the side of the groove bottom 4. This protrusion 18C abuts against the side surface 16 and the groove wall 5 of the mounting groove 3 when the main body 11A is inserted into the mounting groove 3 and compressed. With this configuration, it is possible to suppress contact between the side surface 16 of the convex side of the curved portion 13 and the groove wall 5 of the curved groove portion 7, which are likely to come into contact when the main body 11A is inserted into the mounting groove 3 and compressed. In this embodiment, a plurality of protrusions 18C are provided on the curved portion 13. These multiple protrusions 18C have the same configuration, so in the following, when it is not necessary to distinguish between them, one of them will be described as an example.

[0026] The protruding portion 18C is elongated in the protruding direction, and the side surface 20B (the surface of the protruding portion 18C on the groove bottom 4 side in the natural state) that abuts against the groove wall 5 is formed in a curved shape in a cross section perpendicular to the longitudinal direction. With this configuration, since the protruding portion 18C is elongated in the protruding direction, it is easy to mold the curved portion 13, which is difficult to increase in the circumferential direction of the mounting groove 3. In addition, since the side surface 20B of the protruding portion 18C that abuts against the groove wall 5 is curved in a cross section perpendicular to the longitudinal direction, the contact area with the groove wall 5 can be reduced without impairing moldability. In other words, it is difficult to provide the above-mentioned abutment portions 20, 20A in the curved portion 13, but this side surface 20B functions like the above-mentioned abutment portions 20, 20A. FIG. 4(b) shows an example in which the side surface 20B has a convex curved surface shape that is convex toward the groove bottom 4 in the natural state of the protrusion 18C, but is not limited to this and may have, for example, a concave curved surface shape or may be formed into other curved shapes.

[0027] Like the protruding portion 18 of the straight portion 12 described above, this protruding portion 18C protrudes from a portion on the side surface 16 that is closer to the groove bottom 4 than the center in the groove depth direction. This protruding portion 18C is provided at approximately the same position as the protruding portion 18 of the straight portion 12 in the groove depth direction. The length dimension (protruding dimension) of this protruding portion 18C may be the same as the protruding dimension of the protruding portion 18 of the above-mentioned straight portion 12. In the illustrated example, the dimension of the protruding portion 18C along the circumferential direction of the main body portion 11A is about 1 / 2 of the length dimension (protruding dimension) of the protruding portion 18C. 4(a) and 4(b) show an example in which a plurality of protrusions 18C are formed on the first side surface 16A which is the convex side of the curved portion 13 adjacent to one circumferential side of the straight portion 12, and no protrusions 18C are formed on the convex side of the curved portion 13 adjacent to the other circumferential side of the straight portion 12, but the example is not limited to this. The protrusions 18C of the curved portion 13 may be provided at appropriate positions so as to suppress contact or inclination of the curved portion 13 with the groove wall 5, depending on the radius of curvature of the curved portion 13, the circumferential dimension of the curved portion 13, the protrusions 18 of the adjacent straight portion 12, etc.

[0028] As shown in FIG. 5(a), when the gasket 10C is inserted into the mounting groove 3 and is not compressed, this protrusion 18C is bent at the base end 18b and abuts against the groove wall 5 but does not abut against the side surface 16 of the main body portion 11A. When the gasket 10C inserted into the mounting groove 3 is compressed in the groove depth direction, as shown in Fig. 5(b), the main body 11A is compressed in the groove depth direction and elastically deformed, the dimension of the main body 11A along the groove width direction increases, and the protrusion 18C abuts against the side surface 16 of the main body 11A and the groove wall 5 of the mounting groove 3. The illustrated example shows an example in which, in this state, a gap is formed between the concave side surface 16 of the curved portion 13 and the opposing groove wall 5. In this way, in the curved portion 13, the concave side surface 16 is configured to be unlikely to come into contact with the groove wall 5 even if the protrusion 18C is not provided.

[0029] Next, modified examples of the gasket of this embodiment will be described with reference to Figures 6(a) and 6(b). Note that in the following modified examples, differences from the previously described example will be mainly described, and descriptions of configurations and effects of parts common to the previously described example will be omitted.

[0030] The gasket 10D according to this modification has a different configuration of the protrusions in the curved portion 13 from the above-mentioned examples. In this modification, the gasket 10D includes a first protrusion (protrusion 18C) provided on the first side surface 16A on the convex side, which is one side in the groove width direction of the curved portion 13, and a second protrusion 18D provided on the second side surface 16B on the concave side, which is the other side in the groove width direction of the curved portion 13. The protrusion dimension w3 along the groove width direction of the second protrusion 18D in the natural state is configured to be smaller than the protrusion dimension w2 along the groove width direction of the first protrusion (protrusion 18C). With this configuration, the protrusion dimension w3 of the second protrusion 18D on the second side surface 16B on the concave side of the curved portion 13, which is less likely to come into contact with the groove wall as described above, is reduced, thereby making it possible to more effectively suppress contact between the main body 11A in the curved portion 13 and the groove walls 5, 5 on both sides thereof while reducing the amount of molding material for the gasket 10D.

[0031] In this modification, the first protrusion on the convex side of the curved portion 13 is configured by the protrusion 18C similar to the above example. In the illustrated example, one protrusion 18C and one second protrusion 18D are formed on the curved portion 13, but a plurality of each may be formed. The second protruding portion 18D is provided so as to be at approximately the same position as the protruding portion 18C in the circumferential direction of the curved portion 13. Like the protruding portion 18C, the second protruding portion 18D also has a side surface 20B on the groove bottom 4 side in a natural state formed into a curved shape. The protruding dimension w3 of the second protruding portion 18D in the groove width direction in its natural state may be about 3 / 10 to 7 / 10 of the protruding dimension w2 of the protruding portion 18C in the groove width direction in its natural state. In the illustrated example, the protruding dimension w3 of the second protruding portion 18D is about 1 / 2 of the protruding dimension w2 of the protruding portion 18C. The protruding dimension w3 of the second protruding portion 18D may be less than 1 / 2 of the groove depth dimension d of the mounting groove 3. In this modification, the second protrusion 18D is formed closer to the groove opening 3a than the protrusion 18C in the groove depth direction. The second protrusion 18D may protrude from a portion of the second side surface 16B within a range of 1 / 3 of the dimension along the groove depth direction from the bottom side surface 14. Instead of this embodiment, the second protrusion 18D may be formed at approximately the same position in the groove depth direction as the protrusion 18C. In this case, the protrusion dimension w3 in the groove width direction of the second protrusion 18D may be formed larger than that of the above example.

[0032] The different configurations described in the above examples may be modified, rearranged, or combined as necessary. The protrusions in the above examples are formed in a thin plate shape, but may be formed in other shapes that can bend in the groove depth direction when inserted into the mounting groove. In addition, the protrusions provided with the abutment parts in the above examples may be configured not to have abutment parts. In such a case, the protrusions may be configured to contact the groove walls when inserted into the mounting groove, or may be configured to contact the groove walls and the side surfaces of the main body when inserted into the mounting groove. The specific configuration of the gaskets 10, 10A to 10D according to the respective embodiments is not limited to the configurations described above, and various other modifications are possible. [Explanation of symbols]

[0033] 1 First member 3 Mounting groove 3a Groove opening 4 Groove bottom 5 Groove Wall 6 Straight groove 7 Curved groove 8 Second member 9 Opposite Surface 10,10A~10D Gasket 11, 11A Main body 12 Straight section 13 Curved section 16 Side 16A 1st side 16B 2nd side 18,18A~18C Protrusion 18D Second protrusion 20,20A When connecting 20B Side 21,21A,21B When connecting

Claims

1. a gasket comprising: a main body portion that is inserted into a mounting groove provided in a first member and is compressed by a groove bottom of the mounting groove and an opposing surface of a second member facing the groove bottom to form a seal between the first member and the second member; and a protrusion that is provided on the main body portion so as to protrude in the groove width direction from a first side surface on at least one side in the groove width direction of the groove bottom side, and that is bent toward an opening of the mounting groove when the main body portion is inserted into the mounting groove to avoid contact between the first side surface and a groove wall of the mounting groove and to abut against the groove wall.

2. In claim 1, A gasket characterized in that a protruding dimension along a groove width direction of said protruding portion in a natural state before being inserted into said mounting groove is equal to or greater than half a groove depth dimension of said mounting groove.

3. In claim 1 or 2, The gasket is characterized in that the protrusion is provided with an abutment portion that protrudes in a groove width direction and abuts against the groove wall when the main body is inserted into the mounting groove.

4. In claim 1 or 2, The gasket is characterized in that the protrusion is provided with an abutment portion that protrudes in a groove width direction and abuts against the first side surface when the main body is inserted into the mounting groove.

5. In claim 1 or 2, the main body portion includes a straight portion that is inserted into a straight groove portion that is formed in a straight line in the mounting groove, The gasket is characterized in that the protrusions are provided on both side surfaces of the straight portion on the bottom side of the groove in the groove width direction.

6. In claim 1 or 2, The main body portion includes a curved portion that is inserted into a curved groove portion that is formed in a curved shape in the mounting groove, The gasket is characterized in that the protrusion is provided on the first side surface of the convex side that is on one side in the groove width direction of the curved portion, and abuts against the first side surface and a groove wall of the mounting groove when the main body portion is inserted into the mounting groove and compressed.

7. In claim 6, A gasket characterized in that the protrusion is elongated in the protruding direction, and the side surface that abuts against the groove wall is curved in a cross-sectional view perpendicular to the longitudinal direction.

8. In claim 6, the protruding portion includes a first protruding portion provided on the first side surface and a second protruding portion provided on a second side surface on a concave side which is the other side in the groove width direction of the curved portion, A gasket characterized in that a protruding dimension of the second protruding portion along the groove width direction in a natural state before being inserted into the mounting groove is smaller than a protruding dimension of the first protruding portion along the groove width direction.

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