JP2009058104A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket exercising sealing performance even in a portion having a level difference, without increasing the number of parts. <P>SOLUTION: The gasket 100 is provided with: an attachment part 110 having a first seal part 111 attached to a groove and attached closely to a bottom surface of the groove; and a second seal part 130 provided in an opposite side of the first seal part 111 via the attachment part 110. It is characterized in that the second seal part 130 is composed of: a first protruding part 131 provided along the groove; and a pair of second protruding parts 132, 133 provided integrally with the first protruding part 131 along both sides of the first protruding part 131. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gasket.

  In various apparatuses, a gasket is used to prevent leakage of fluid such as liquid or gas. For example, relatively large gaskets are used for automobile engines in various applications such as inlet manifolds, filter blankets, cylinder head covers, and cam covers.

  Generally, a gasket seals a gap between two surfaces. In the various applications described above, a groove is generally provided in a member having one of the two surfaces, and a gasket is generally attached to the groove. With reference to FIG. 9, the gasket which concerns on a prior art example is demonstrated. FIG. 9 is a schematic cross-sectional view of a conventional gasket.

  The gasket 300 according to the conventional example is mounted in a groove provided in a member having one of two surfaces, and seals a gap between these two surfaces. And the gasket 300 is provided with the mounting part 310 with which a groove | channel is mounted | worn, and the overhang | projection part 320 which protrudes on one member surface from a groove | channel side surface side, and is pinched | interposed between two surfaces. A first seal portion 311 that is in close contact with the groove bottom surface is provided at the tip of the mounting portion 310, and a second seal portion 330 is provided on the opposite side of the first seal portion 311 through the mounting portion 310. Is provided. Further, the overhanging portion 320 is provided with a pair of convex portions 341 and 342 that abut against the other of the two surfaces. With the above configuration, the gap between the two surfaces is sealed mainly by the first seal portion 311 and the second seal portion 330.

  Here, the depth of the groove in which the gasket is mounted may vary depending on the location due to the influence of groove processing, assembly tolerance, and the like. In recent years, in the case of an automobile engine, a material having low rigidity such as a resin material or aluminum tends to be used as a material of a member constituting the engine for the purpose of weight reduction. When the gasket is in close contact with a member made of such a material having low rigidity, the member is deformed unless the reaction force of the gasket is lowered. In view of the above, in recent years, a low reaction force is required for gaskets (see Patent Documents 1 to 4).

  In addition, when the member having the other surface of the two surfaces described above is composed of one member, the surface to which the gasket is in close contact is generally composed of a surface having no step, so that there is no problem. However, when the member having the other surface is composed of a plurality of members, the surface to which the gasket is in close contact becomes a surface having a step. Is required. Of course, even if the member having the other surface is composed of one member, if there is a step on the surface to which the gasket is in close contact, some device is similarly required.

In this way, when there is a step on the surface to which the gasket is in close contact, a technique for applying a liquid seal such as silicone rubber to the step portion is known as a technique for properly exhibiting the sealing performance (see Patent Document 5). . However, when a technique for applying a liquid seal is employed, a liquid seal is required separately from the gasket, and a process for applying the liquid seal is required. Moreover, although the gap of the stepped portion can be filled by applying a liquid seal, sufficient surface pressure cannot be obtained at the corner (E2 portion (see FIG. 6)), and the gasket is There is also a problem in that the gasket is stuck to the other surface, which makes it difficult to remove the gasket.
JP 2003-26913 A Japanese Patent Laid-Open No. 2002-71024 JP 2002-21635 A Japanese Patent Laid-Open No. 10-9395 JP 2006-132485 A

  An object of the present invention is to provide a gasket that can exhibit sealing performance even in a stepped portion without increasing the number of parts.

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

That is, the present invention
A mounting portion having a first seal portion attached to the groove and in close contact with the groove bottom surface of the groove;
A second seal portion provided on the opposite side of the first seal portion via the mounting portion;
In a gasket comprising:
The second seal part is provided integrally with the first convex part provided along the groove, the projection amount being smaller than that of the first convex part, and along both sides of the first convex part. It is comprised from a pair of 2nd convex part.

  According to this invention, when a 1st convex part compresses, the deformation | transformation to the both sides in a 1st convex part can be suppressed by a pair of 2nd convex part integrally provided in the both sides. As a result, a decrease in the reaction force of the first convex portion can be suppressed. Therefore, according to the gasket of the present invention, the sealing performance can be exhibited even in a stepped portion.

  This point will be described in more detail. When there is a step on the surface to which the gasket is in close contact, the seal portion of the gasket is deformed along the step. In this case, stress concentrates on the portion of the gasket that hits the corner of the step, and the surface pressure applied to the “contact surface” by the gasket is the highest at the corner and the portion that hits the corner of the step. Is the smallest. Here, in order to make the seal part of the gasket easy to deform along the step, it is desirable to increase the flexibility of the seal part. Concentration increases the deformation of the seal portion, the surface pressure of the portion that hits the corner portion becomes too small, and the sealing performance of the portion decreases. On the other hand, according to the present invention, by providing the second convex portion as described above, it is possible to suppress a reduction in the reaction force of the first convex portion, and to exhibit a sealing property even at a stepped portion. Is possible.

  As described above, according to the present invention, the sealing performance can be exhibited even in a stepped portion without increasing the number of parts.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Example 1)
With reference to FIGS. 1-8, the gasket which concerns on Example 1 of this invention is demonstrated.

<Composition of gasket>
With reference to FIGS. 1-3, the structure of the gasket which concerns on Example 1 of this invention is demonstrated. FIG. 1 is a part of a plan view of a gasket according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of a gasket according to Embodiment 1 of the present invention. 2 is a sectional view taken along line XX in FIG. FIG. 3 is an enlarged view of a part of a schematic cross-sectional view of the gasket according to the first embodiment of the present invention.

  The gasket 100 according to the present embodiment is mounted in a groove provided in a member having one of two surfaces and seals a gap between these two surfaces.

  And the gasket 100 is provided with the mounting part 110 with which a groove | channel is mounted | worn, and the overhang | projection part 120 which protrudes on one member surface from a groove | channel side surface side, and is pinched | interposed between two surfaces. In addition, a first seal portion 111 that is in close contact with the groove bottom surface is provided at the tip of the mounting portion 110, and a second seal portion 130 is provided on the opposite side of the mounting portion 110 from the first seal portion 111. Is provided. Further, the protruding portion 120 is provided with a pair of convex portions 141 and 142 that abut against the other of the two surfaces. With the above configuration, the gap between the two surfaces is mainly sealed by the first seal portion 111 and the second seal portion 130.

  In addition, a plurality of pairs of protrusions 151 and 152 are provided on both side surfaces of the mounting portion 110 at predetermined intervals in the longitudinal direction. These protrusions 151 and 152 are provided in contact with both side surfaces of the groove to prevent the gasket 100 from falling, buckling or shifting in the groove.

  The mounting portion 110 is configured with inclined surfaces on both sides so that the width gradually decreases toward the tip. That is, as shown in FIG. 2, both side surfaces of the mounting portion 110 are inclined by the inclination angle α. Further, the overhang portion 120 is provided in order to further stabilize the mounting state of the gasket 100. Although this overhanging portion 120 is sandwiched between two surfaces, since the pair of convex portions 141 and 142 provided on the overhanging portion 120 are configured to abut against the other surface, the reaction force is increased. Can be suppressed.

  In the present embodiment, the second seal portion 130 has a first protrusion 131 provided along the groove, a protrusion amount smaller than that of the first protrusion 131, and along both sides of the first protrusion 131. And a pair of second convex portions 132 and 133 provided integrally with the first convex portion 131. The first protrusion 131 has a substantially semicircular cross section perpendicular to the longitudinal direction, and the second protrusions 132 and 133 have a substantially (1/4) circular cross section perpendicular to the longitudinal direction.

  In the present embodiment, the width A of the first protrusion 131 is 0.6 mm, and the width B of the second protrusions 132 and 133 is 0.3 mm. The protrusion amount (height) C of the second protrusions 132 and 133 is 0.3 mm, and the protrusion amount (height) C + D of the first protrusion 131 is 0.5 mm. That is, the first protrusion 131 protrudes further by D (0.2 mm) than the second protrusions 132 and 133. Further, the curvature radius R1 of the first protrusion 131 and the curvature radius R2 of the second protrusions 132 and 133 are both 0.3 mm. In addition, these dimensions can be appropriately set according to the application location, the material of various components, and the like.

In addition, the material of the gasket 100 according to the present embodiment is an elastomer, and more specifically, an acrylic rubber, a nitrile rubber, a fluorine rubber, or the like can be employed. For example, gaskets for various uses used in engines are designed so that the cross-sectional shape thereof is usually a vertically long shape having a height of 5 to 20 mm and a width of 1.5 to 6 mm. In the case of the gasket 100 according to the present embodiment, the aspect ratio of the cross-sectional shape is designed to be 0.2 to 0.3.

<Function of gasket>
In particular, the function of the gasket 100 according to the present embodiment will be described with reference to FIGS. FIG. 4 is a schematic cross-sectional view showing a state before completion of mounting of the gasket according to Embodiment 1 of the present invention. FIG. 5 is a schematic cross-sectional view showing a state where the gasket according to the first embodiment of the present invention is completely attached. FIG. 5 shows a cross section perpendicular to the longitudinal direction. FIG. 6 is a schematic cross-sectional view showing a state where the gasket according to the first embodiment of the present invention is completely attached. In addition, in FIG. 6, the cross section (cross section which cut | disconnected the center surface of the width direction of a gasket) parallel to a longitudinal direction is shown. FIG. 7 is a schematic cross-sectional view for explaining the behavior of the second seal portion in the gasket according to the embodiment of the present invention.

  The gasket 100 which concerns on a present Example is mounted | worn with the groove | channel provided in the member which has one side of two surfaces as above-mentioned, and seals the clearance gap between these two surfaces. In this embodiment, the member having one of the two surfaces is the head cover 500, and the member having the other of the two surfaces is constituted by the cylinder head 600a and the chain cover 600b. I will explain.

  The head cover 500 is provided with a groove 501. The mounting portion 110 of the gasket 100 is mounted in the groove 501. As shown in FIG. 4, after mounting the mounting portion 110 of the gasket 100 in the groove 501, the cylinder head 600a, the chain cover 600b, and the head cover 500 are assembled. The mounting portion 110 of the gasket 100 is set to have a height larger than the depth of the groove 501 and a width smaller than the width of the groove 501 (see FIG. 4).

  When the cylinder head 600a and the chain cover 600b and the head cover 500 are assembled, the gasket 100 is formed by the surface of the cylinder head 600a and the groove bottom surface 501a of the groove 501 in the head cover 500, and the surface of the chain cover 600b and the groove 501 in the head cover 500. The groove bottom surface 501a is compressed in the vertical direction. As a result, the first seal portion 111 of the gasket 100 is in close contact with the groove bottom surface 501a, and the second seal portion 130 is in close contact with the surface of the cylinder head 600a or the surface of the chain cover 600b. In addition, the pair of convex portions 141 and 142 provided on the overhang portion 120 are also in close contact with the surface of the cylinder head 600a or the surface of the chain cover 600b.

  With the above configuration, the gap between the two surfaces is mainly sealed by the first seal portion 111 and the second seal portion 130.

  Here, in the present embodiment, as described above, the member having the other of the two surfaces is constituted by the cylinder head 600a and the chain cover 600b. Therefore, the other surface is not a flat surface, and a step is formed as shown in FIG. Thereby, the 2nd seal part 130 of gasket 100 changes so that a level difference may be met. In this case, stress concentrates on the portion of the gasket 100 that hits the corner of the step (the portion indicated by arrow E1 in FIG. 6), and the surface pressure applied to the other surface by the gasket 100 is the portion E1 that hits the corner. Is the highest, and the portion that hits the corner of the step (the portion indicated by arrow E2 in FIG. 6) is the smallest.

  In the present embodiment, as described above, the second seal portion 130 includes the first convex portion 131 and the pair of second convex portions 132 and 133. And the 1st convex part 131 which protrudes most is contact | adhered fundamentally with respect to the other surface.

Here, the first protrusion 131 protrudes further than the pair of second protrusions 132 and 133 and has a narrower width than the entire width of the second seal portion 130. Accordingly, the first convex portion 1
31 is configured such that its rigidity is relatively small and flexibility is high. Thereby, even if the level | step difference is large, the 1st convex part 131 is comprised so that it may closely_contact | adhere along a level | step difference. Thus, the 1st convex part 131 exhibits the function which deform | transforms along a level | step difference.

  Then, as shown in FIG. 7, when the first convex portion 131 receives pressure P from the other surface, a force Q is applied to the first convex portion 131 so that the flesh escapes to both sides. As a result, in the first convex portion 131, when the flesh is deformed too much so as to escape to both sides, the distribution of the surface pressure on the other surface is dispersed, the surface pressure becomes insufficient, and the sealing performance is lowered. End up.

  However, in this embodiment, as described above, the pair of second convex portions 132 and 133 provided integrally with the first convex portion 131 are provided along both sides of the first convex portion 131. Thereby, the deformation | transformation to the both sides in the 1st convex part 131 can be suppressed. As a result, a reduction in the surface pressure of the first convex portion 131 can be suppressed. Thus, the 2nd convex parts 132 and 133 exhibit the function which controls the deformation to the both sides in the 1st convex part 131.

  In addition, in order to exhibit the function in which the 1st convex part 131 deform | transforms along a level | step difference, and the 2nd convex parts 132 and 133 exhibit the function to suppress the deformation | transformation to the both sides in the 1st convex part 131, these Needless to say, it is necessary to set the shape dimension to an appropriate value. In particular, the dimension of the radius of curvature is important.

  For example, if the height, width, and curvature of the first convex portion 131 are too small, the volume is insufficient, so if the step is large, the first convex portion 131 does not adhere to the corner of the step, The surface pressure to the corner of the first convex portion 131 is lowered. In addition, if the height, width, and curvature of the first convex portion 131 are too large, the flexibility of the first convex portion 131 is lowered, and if the step is large, the first convex portion 131 cannot be sufficiently deformed along the step, and is formed at the corner of the step. On the other hand, the 1st convex part 131 does not closely_contact | adhere, or the surface pressure to the corner part of the 1st convex part 131 will become low.

  If the height, width, and curvature of the second protrusions 132 and 133 are too small, the deformation of the first protrusion 131 to both sides cannot be suppressed so much. The first convex portion 131 does not adhere, or the surface pressure on the corner portion of the first convex portion 131 becomes low. In addition, if the height, width, and curvature of the second convex portions 132 and 133 are too large, the reaction force becomes large when the second convex portions 132 and 133 come into contact with the other surface. Regardless of the presence or absence, it becomes impossible to meet the demand for reducing the reaction force of the gasket 100.

  As described above, when A = 0.6 mm, B = 0.3 mm, C = 0.3 mm, D = 0.2 mm, and R1 = R2 = 0.3 mm, the step on the other surface is 0.4 mm. Even in the case, the sealing property can be suitably exhibited. Of these, the curvature radii R1 and R2 are the most important design items. Note that it is desirable that these radii of curvature be as large as possible because distortion during compression can be suppressed. The cross-sectional shape of the gasket 100 is preferably symmetrical with respect to the center plane in the width direction. By making it bilaterally symmetric, the gasket 100 can be prevented from falling or buckling when the gasket 100 is compressed.

<Excellent points of this embodiment>
According to the gasket 100 according to the present embodiment, even if there is a step on the surface (the other surface) to which the gasket 100 is in close contact, the first convex portion 131 is deformed along the step. Moreover, even if the first convex portion 131 receives pressure P from the other surface and the flesh tends to escape to both sides, the pair of second convex portions 132 and 133 cause the first convex portion 131 to be deformed to both sides. Can be suppressed. As a result, a reduction in the surface pressure of the first convex portion 131 can be suppressed. Therefore, according to the gasket 100 which concerns on a present Example, a sealing performance can be exhibited also in the part with a level | step difference. And according to the gasket 100 which concerns on a present Example, even if the gasket 100 single-piece | unit has a level | step difference, a sealing performance can be exhibited, and a liquid seal etc. are not required.

  Moreover, the 2nd seal | sticker part 130 is comprised from the 1st convex part 131 and a pair of 2nd convex part 132,133, and can make the cross-sectional area comparatively large as a whole. Therefore, stress concentration generated in the second seal portion 130 when the gasket 100 is compressed can be alleviated, and damage due to stress concentration can be suppressed. Since the reaction force of the entire gasket 100 can be set to the same level as that of the conventional product, the gasket 100 according to the present embodiment can be used in the same manner as the conventional product even when there is no step on the contact surface.

(Example 2)
FIG. 8 shows a second embodiment of the present invention. In the first embodiment, the case of the configuration including the overhang portion has been described, but in the present embodiment, the case of the configuration including no overhang portion will be described. FIG. 8 is a schematic cross-sectional view of a gasket according to Embodiment 2 of the present invention.

  Similar to the gasket 100 according to the first embodiment, the gasket 200 according to the present embodiment includes a mounting portion 210 that is mounted in the groove. In addition, a first seal portion 211 that is in close contact with the groove bottom surface is provided at the tip of the mounting portion 210, and a second seal portion 230 is provided on the side opposite to the first seal portion 211 through the mounting portion 210. Is provided. It should be noted that both sides of the mounting portion 210 in this embodiment are not inclined.

  Furthermore, the second seal portion 230 includes a first convex portion 231 provided along the groove, and a projection amount smaller than that of the first convex portion 231, and the first convex portion along both sides of the first convex portion 231. 231 and a pair of second convex portions 232 and 233 provided integrally. The first convex portion 231 has a substantially semicircular sectional shape perpendicular to the longitudinal direction, and the second convex portions 232 and 233 have a substantially (¼) circular sectional shape perpendicular to the longitudinal direction. is there.

  As described above, the gasket 200 according to the present embodiment does not include the overhang portion 120 and the pair of convex portions 141 and 142 provided in the overhang portion 120 in the gasket 100 according to the first embodiment. The configuration is the same as that of the gasket 100 according to the first embodiment except that both side surfaces of the portion 210 are not inclined.

  Therefore, also in the gasket 200 according to the present embodiment, the same effect as in the case of the first embodiment can be obtained. In addition, the gasket 200 according to the present embodiment is slightly inferior in terms of the maximum principal strain as compared with the gasket 100 according to the first embodiment, but the sealing performance against the stepped portion (the higher the maximum surface pressure is better) and the reaction force is low. It is excellent in terms of safety. These are clear from the FEM analysis results shown below.

(FEM analysis results)
The result of the FEM analysis which evaluates the sealing performance with respect to a level | step difference is demonstrated about the gasket 100 concerning Example 1 and the gasket 100 which concerns on a conventional product. FIG. 10 is a schematic diagram showing a model of FEM analysis. 11 to 13 are tables showing FEM analysis results.

In FIG. 10, the arrow T indicates the gasket. In this analysis, the length L of the gasket T was set to 7.5 mm, and the standard hardness “Duro A” of the gasket T was set to 50. For the conventional product and the gasket 100 according to Example 1, the height h0 was set to 7.95 mm, the width d0 was set to 6.0 mm, and the inclination angle α was set to 2.0 degrees (see FIG. 2 for the position of the dimensions). (See FIG. 4). For the gasket 200 according to Example 2, the height h0 was set to 7.95 mm, and the width d0 was set to 1.79 mm (see FIG. 8 for the position of dimensions). Further, the depth H of the groove 501 was set to 4.50 mm, and the width W of the groove 501 was set to 3.15 mm (refer to FIGS. 4 and 8 for the position of dimensions). Further, regarding the dimensions of the second seal portions 130 and 230 in the gasket 100 according to the first embodiment and the gasket 200 according to the second embodiment, A = 0.6 mm, B = 0.3 mm, C = 0.3 mm, D = 0.2 mm, and R1 = R2 = 0.3 mm.

  Then, analysis was performed in the case where the step S between the cylinder head 600a and the chain cover 600b was 0.1 mm, 0.2 mm, 0.3 mm, and 0.4 mm. The analysis was performed when the gasket T was compressed so that the compression rate of the gasket T was 0.33, and the maximum surface pressure (MPa), the reaction force (N / mm) at the portion that hits the corner of the step, and The maximum principal strain was calculated. Here, regarding the sealing performance, if the maximum surface pressure with respect to the corner portion is 1.0 MPa or more, the sealing is possible, and if it is less than 1.0 MPa, the sealing is impossible.

  FIG. 11 compares the analysis results of the conventional product and the gasket according to Example 1. From this result, the gasket 100 according to the present example can reduce the maximum main strain as compared with the conventional product while keeping the reaction force equal to that of the conventional product, and improves the sealing performance at the step portion. I can see that In the case of the conventional product, sealing becomes impossible when the level difference becomes 0.4 mm, whereas in the case of the gasket 100 according to the present embodiment, the level difference becomes 0.4 mm. It can be seen that it can be sealed.

  FIG. 12 compares the analysis results of the gasket according to Example 1 and the gasket according to Example 2. From this result, for the gasket 200 according to Example 2, the maximum principal strain is inferior to that of Example 1 (similar to that of the conventional product), but the maximum surface pressure and reaction force at the portion hitting the corner of the step are as follows: It turns out that it is superior to Example 1. Therefore, it can be seen that the second embodiment is better when the step becomes large or when the rigidity of the material of the cylinder head 600a and the chain cover 600b is low.

  FIG. 13 compares the crushing amounts of the gasket 100 according to the first embodiment and the gasket 200 according to the second embodiment when the maximum surface pressure at the portion corresponding to the corner of the step reaches 1.0 MPa. From this result, it can be seen that the sealing in Example 2 can be performed with a smaller amount of crushing.

FIG. 1 is a part of a plan view of a gasket according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of a gasket according to Embodiment 1 of the present invention. FIG. 3 is an enlarged view of a part of a schematic cross-sectional view of the gasket according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a state before completion of mounting of the gasket according to Embodiment 1 of the present invention. FIG. 5 is a schematic cross-sectional view showing a state where the gasket according to the first embodiment of the present invention is completely attached. FIG. 6 is a schematic cross-sectional view showing a state where the gasket according to the first embodiment of the present invention is completely attached. FIG. 7 is a schematic cross-sectional view for explaining the behavior of the second seal portion in the gasket according to the embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of a gasket according to Embodiment 2 of the present invention. FIG. 9 is a schematic cross-sectional view of a conventional gasket. FIG. 10 is a schematic diagram showing a model of FEM analysis. FIG. 11 is a table showing FEM analysis results. FIG. 12 is a table showing FEM analysis results. FIG. 13 is a table showing FEM analysis results.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Gasket 110 Mounting part 111 1st seal | sticker part 120 Overhang | projection part 130 2nd seal | sticker part 131 1st convex part 132,133 2nd convex part 141,142 Convex part 151,152 Protrusion part 200 Gasket 210 Mounting part 211 1st seal | sticker Part 230 Second seal part 231 First convex part 232, 233 Second convex part 500 Head cover 501 Groove 501a Groove bottom face 600a Cylinder head 600b Chain cover

Claims (1)

A mounting portion having a first seal portion attached to the groove and in close contact with the groove bottom surface of the groove;
A second seal portion provided on the opposite side of the first seal portion via the mounting portion;
In a gasket comprising:
The second seal part is provided integrally with the first convex part provided along the groove, the projection amount being smaller than that of the first convex part, and along both sides of the first convex part. A gasket characterized by comprising a pair of second protrusions.

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