Positioning auxiliary structure

Abstract

To provide a positioning auxiliary structure enabling positioning of a gasket without changing a shape of the gasket or a shape of a fitting groove.SOLUTION: A gasket 30 is formed into a prescribed shape where a shape in a non-installed state is a non-circular annular state. The gasket 30 has a first linear part 31 forming a linear state extending in a direction intersecting with an extending direction of the gasket 30 on its outer surface. A cover body 20 has a fitting groove 23 and a second linear part 51. The fitting groove 23 is extended in a mode forming the prescribed shape being the non-circular annular state and is formed in a groove shape where the gasket 30 is fitted. The second linear part 51 is provided on a side wall 20b and an inner peripheral surface of a flange part 20c, and is formed in a linear state extending in the same direction as the fitting direction of the gasket 30. The second linear part 51 is provided at a position side by side with the first linear part 31 in a direction intersecting an extending direction of the fitting groove 23, in a state where the gasket 30 is fitted to the fitting groove 23 at a normal position.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a positioning assistance structure. [Background technology]

[0002] Conventionally, a gasket has often been provided between two members for sealing (for example, Patent Document 1). In the seal structure described in Patent Document 1, an annular mounting groove is provided in one of two members (hereinafter, the mounting target member). An annular gasket is fitted into this mounting groove. The two members are then assembled with the gasket sandwiched between them. In this way, the gasket is interposed between the two members, and the gap between the members is sealed by the gasket.

[0003] In the above seal structure, the mounting groove and the gasket have a non-circular, three-dimensional shape, so that if the mounting position of the gasket relative to the mounting target component is shifted from the correct position, the degree of adhesion between the inner surface of the mounting groove and the outer surface of the gasket at the mounting groove and the bent portion of the gasket may decrease, leading to a decrease in sealing performance.

[0004] In the seal structure described in Patent Document 1, an engaging protrusion is provided on the outer surface of the gasket, and a notch is provided on the inner surface of the mounting groove in the mounting target component. When the gasket is mounted, the protrusion of the gasket engages with the notch of the mounting groove. Through this engagement, the gasket is positioned relative to the mounting target component. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4677283 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned seal structure, it is necessary to change the shape of the gasket and the shape of the mounting groove in order to position the gasket relative to the mounting target component. Such shape changes may unnecessarily change the contact pressure between the outer surface of the gasket and the inner surface of the mounting groove, which may result in a deterioration of the sealing performance. [Means for solving the problem]

[0007] The positioning assistance structure for solving the above problem is a positioning assistance structure that assists in positioning a gasket to a target attachment component, wherein the gasket has a predetermined shape that is a non-circular ring when not attached, and has a first linear portion that extends linearly on the outer surface of the gasket in a direction intersecting the extension direction of the gasket, and the target attachment component extends in a manner to form the predetermined shape that is a non-circular ring, and has a mounting groove that has a groove shape into which the gasket is fitted, and a second linear portion that is provided on the outer surface of a wall portion extending along the mounting groove, and is located in a position aligned with the first linear portion in a direction intersecting the extension direction of the mounting groove when the gasket is fitted into the mounting groove in the correct position, and that extends in the same direction as the mounting direction of the gasket.

[0008] According to the above configuration, the gasket can be positioned relative to the target component by a simple operation of aligning the first linear portion of the gasket with the second linear portion of the target component without employing a structure for engaging the outer surface of the gasket with the inner surface of the mounting groove. Therefore, the gasket can be positioned without changing the shape of the gasket or the shape of the mounting groove. [Brief description of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view showing a cylinder head cover to which a positioning assistance structure according to an embodiment is applied, together with a cylinder head; [Diagram 2]FIG. 2 is a cross-sectional view of the cylinder head cover and the cylinder head. [Diagram 3] FIG. 2 is a bottom view of the cylinder head cover. [Figure 4] 4 is an exploded perspective view showing a first recessed portion and its periphery from the inner periphery side. FIG. [Diagram 5] 4 is an exploded cross-sectional side view showing a first recess and its periphery from the inner periphery side. FIG. [Figure 6] 4 is a side cross-sectional view showing an enlarged view of the mark protrusion and its surroundings from the inner periphery side. FIG. [Figure 7] FIG. 2 is a bottom view of the mark protrusion and its surroundings. [Figure 8] FIG. 13 is a bottom view of a mark protrusion and its surroundings according to another embodiment. [Figure 9] FIG. 13 is a bottom view of a mark protrusion and its surroundings according to another embodiment. [Figure 10] FIG. 11 is a side cross-sectional view showing an enlarged view of a colored portion and its periphery from the inner periphery side according to another embodiment. [Figure 11] FIG. 13 is a bottom view of a mark protrusion and its surroundings according to another embodiment. [Figure 12] 13 is an enlarged side view showing a first linear portion and its periphery of a gasket according to another embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of a positioning assistance structure will be described below with reference to Figures 1 to 7. The positioning assistance structure of this embodiment is applied to a cylinder head cover of an internal combustion engine. As shown in Figures 1 to 3, the cylinder head cover (hereinafter referred to as cover 10) includes a cover body 20 attached to a cylinder head 40 that constitutes an internal combustion engine, and an annular gasket 30 that seals between the cylinder head 40 and the cover body 20. The cover body 20 is made of a hard resin material. The gasket 30 is integrally molded from a flexible material such as rubber.

[0011] The cover body 20 has an annular mounting groove 23. A gasket 30 is attached to this mounting groove 23. The cover body 20 is fixed to the cylinder head 40 with the gasket 30 sandwiched between the cover body 20 and the cylinder head 40 (as shown in FIG. 2). In this embodiment, the cover body 20 corresponds to the mounting target member.

[0012] <Cover body> As shown in Figures 1 and 3, the cover body 20 has a top wall 20a facing the cylinder head 40, a side wall 20b provided around the entire periphery of the top wall 20a, and a flange portion 20c provided around the entire periphery of the side wall 20b.

[0013] The flange portion 20c is provided with a plurality of mounting portions 21 each having a bolt hole 22. The mounting portions 21 protrude from the flange portion 20c toward the outer circumferential side of the cover body 20. The mounting portions 21 are provided at intervals from one another in the circumferential direction of the cover body 20.

[0014] The cover 10 is attached to the cylinder head 40 by inserting bolts (not shown) into the bolt holes 22 and screwing them into the bolt holes 42 of the cylinder head 40 . <Mounting groove> 3 to 5, a bottomed rectangular mounting groove 23 is provided around the entire periphery on the back surface of the flange portion 20c. A gasket 30 is fitted and attached in the mounting groove 23. In the following description, the mounting groove 23, i.e., the inner periphery side and the outer periphery side of the gasket 30, will be simply referred to as the inner periphery side and the outer periphery side.

[0015] The mounting groove 23 extends in a manner that forms a predetermined non-circular annular shape. Specifically, the mounting groove 23 has a base 24 that extends along an imaginary plane V1 (see FIG. 5), and a first recessed portion 25 and a second recessed portion 26 that each protrude from the imaginary plane V1.

[0016] As shown in FIG. 5, the first recess 25 extends along the shape of the first protruding portion 45 of the cylinder head 40 (see FIG. 1) in such a manner that a part of the mounting groove 23 protrudes toward the side away from the cylinder head 40 (see FIG. 1). As shown in FIG. 3, the second recess 26 extends along the shape of the second protruding portion 46 of the cylinder head 40 in such a manner that a part of the mounting groove 23 protrudes toward the side away from the cylinder head 40 (see FIG. 1). As shown in FIG. 1, the first protruding portion 45 and the second protruding portion 46 have insertion holes 45a, 46a, 46b through which the intake camshaft or the exhaust camshaft (both not shown) of the internal combustion engine is inserted. Therefore, the first protruding portion 45 and the second protruding portion 46 protrude toward the cover 10 more than other parts of the cylinder head 40.

[0017] <Gasket> As shown in Figures 1 and 2, the gasket 30 has a generally rectangular cross section. The gasket 30 has a predetermined shape that is a noncircular annular shape when not attached. In more detail, as shown in Figures 1 and 3, the gasket 30 has a gasket base 34 attached to the base 24, a first bent portion 35 attached to the first recessed portion 25, and a second bent portion 36 attached to the second recessed portion 26.

[0018] The gasket base 34 extends along the base 24. The first bent portion 35 extends along the first recessed portion 25 in a manner that a portion of the gasket 30 protrudes toward the side adjacent to the cover body 20. The second bent portion 36 extends along the second recessed portion 26 in a manner that a portion of the gasket 30 protrudes toward the side adjacent to the cover body 20.

[0019] 1, the gasket 30 is bent at the boundary between the first bent portion 35 and the gasket base portion 34 and at the boundary between the second bent portion 36 and the gasket base portion 34. Therefore, the gasket 30 has a line (hereinafter, first linear portion 31) indicating an angled portion on the outer surface of these boundary portions. This first linear portion 31 is a bending ridge line at the bent portion of the gasket 30. The first linear portion 31 has a linear shape that extends on the outer surface of the gasket 30 in a direction perpendicular to the extension direction of the gasket 30 (hereinafter, extension direction).

[0020] 3 to 7, in this embodiment, a mark protrusion 50 is provided on the cover body 20. The mark protrusion 50 can be used to attach the gasket 30 to the cover body 20.

[0021] <Protruding mark> The mark protrusion 50 will be described in detail below. The mark protrusion 50 is provided on the inner peripheral surface of the side wall 20b and the flange portion 20c of the cover body 20 in a manner to protrude inward. In this embodiment, the inner peripheral surface of the side wall 20b and the flange portion 20c corresponds to the outer surface of the wall portion extending along the mounting groove 23. The mark protrusion 50 is provided in the vicinity of the boundary between the first recessed portion 25 and the base portion 24 (more specifically, on the inner peripheral side of the first recessed portion 25). The mark protrusion 50 has a cross section in the form of a two-step staircase and extends in the same direction as the mounting direction of the gasket 30 to the cover body 20. In this embodiment, the mounting direction of the gasket 30 is the same as the depth direction of the mounting groove 23 (more specifically, the base portion 24) and is the same as the direction perpendicular to the virtual plane V1 (see FIG. 5).

[0022] In this embodiment, the ridge lines of the angled portions of the two-step mark protrusion 50 constitute three linear portions 51, 52, 53 extending in the same direction as the mounting direction of the gasket 30. More specifically, the mark protrusion 50 has a second linear portion 51 located at the center of the three linear portions 51, 52, 53 in the arrangement direction, and a pair of sub-linear portions 52, 53 provided at positions sandwiching the second linear portion 51 in the arrangement direction. The mark protrusion 50 is in a two-step staircase shape, with a lower step portion 55 being a portion sandwiched between one of the pair of sub-linear portions 52, 53 and the second linear portion 51, and an upper step portion 56 being a portion sandwiched between the other of the pair of sub-linear portions 52, 53 and the second linear portion 51. In this embodiment, the step-shaped portion consisting of the lower step portion 55 and the upper step portion 56 corresponds to a step portion having a step shape in which one side portion protrudes more than the other side portion with the second linear portion 51 as the boundary.

[0023] <Second linear part> In this embodiment, the position of the second linear portion 51 is determined so that when the gasket 30 is fitted into the mounting groove 23 in the correct position, the position of the first linear portion 31 and the position of the second linear portion 51 have the following relationship.

[0024] 6 and 7, in this case, the first linear portion 31 and the second linear portion 51 are aligned in a direction perpendicular to the extension direction of the mounting groove 23 (the vertical direction in FIG. 7) when viewed from the mounting direction of the gasket 30. In this embodiment, a plane extending in a direction perpendicular to the extension direction of the mounting groove 23 when viewed from the mounting direction of the gasket 30 is defined as an "imaginary plane V2." In this embodiment, when the gasket 30 is fitted into the mounting groove 23 at the correct position, the imaginary plane V2 extends in a manner including the first linear portion 31, and the second linear portion 51 extends on the imaginary plane V2.

[0025] In this embodiment, the positions of the pair of sub-linear portions 52, 53 are determined as follows.

[0026] Based on the results of various experiments and simulations performed by the inventors, a range of positions for mounting the gasket 30 to the mounting groove 23 where the gasket 30 can fully exhibit its sealing function (hereinafter, the allowable position range) has been determined in advance. The positions of the pair of sub-linear portions 52, 53 are determined so that when the gasket 30 is mounted within the allowable position range, the position of the first linear portion 31 as viewed from the mounting direction is between the pair of sub-linear portions 52, 53 (the range indicated by "AR" in FIG. 7).

[0027] <effect> The operation of this embodiment will now be described. In this embodiment, the gasket 30 is attached to the cover body 20 by fitting the gasket 30 into the attachment groove 23 of the cover body 20. This attachment is performed by utilizing the mark protrusion 50. More specifically, the gasket 30 is fitted into the attachment groove 23 of the cover body 20 in such a manner that the first linear portion 31 of the gasket 30 and the second linear portion 51 of the cover body 20 are aligned in a direction perpendicular to the extension direction of the attachment groove 23 as viewed from the attachment direction of the gasket 30.

[0028] As a result, the gasket 30 can be accurately positioned relative to the cover body 20 by a simple task of aligning the first linear portion 31 and the second linear portion 51, without employing a structure for engaging the outer surface of the gasket 30 with the inner surface of the mounting groove 23. Therefore, according to this embodiment, the gasket 30 can be positioned without changing the shape of the gasket 30 or the shape of the mounting groove 23.

[0029] In addition, when the gasket 30 is attached to the cover body 20, it can be confirmed that the gasket 30 is attached in the correct position based on the positional relationship between the first linear portion 31 and the second linear portion 51 and the positional relationship between the first linear portion 31 and the pair of sub-linear portions 52, 53. In detail, it can be determined that the gasket 30 is attached in the correct position by the fact that the first linear portion 31 of the gasket 30 and the second linear portion 51 of the cover body 20 are aligned in a direction perpendicular to the extension direction of the attachment groove 23 as viewed from the attachment direction of the gasket 30. In addition, it can be determined that the gasket 30 is attached within the above-mentioned allowable position range by the fact that the first linear portion 31 of the gasket 30 is located between the pair of sub-linear portions 52, 53 as viewed from the attachment direction of the gasket 30.

[0030] <Effects> According to this embodiment, the following effects can be obtained. (1) The gasket 30 has a predetermined shape that is a noncircular annular shape in an unattached state. The gasket 30 has a first linear portion 31 that is linear and extends in a direction perpendicular to the extension direction of the gasket 30 on its outer surface. The cover body 20 has an attachment groove 23 and a second linear portion 51. The attachment groove 23 extends in a manner that forms the predetermined shape that is a noncircular annular shape, and forms a groove shape into which the gasket 30 is fitted. The second linear portion 51 is provided on the inner peripheral surfaces of the side wall 20b and the flange portion 20c, and forms a line that extends in the same direction as the attachment direction of the gasket 30. The second linear portion 51 is provided at a position aligned with the first linear portion 31 in a direction perpendicular to the extension direction of the attachment groove 23 when the gasket 30 is fitted in the attachment groove 23 at the correct position.

[0031] According to this embodiment, by using the first linear portion 31 and the second linear portion 51, the gasket 30 can be positioned without changing the shape of the gasket 30 or the shape of the mounting groove 23.

[0032] (2) The second linear portion 51 extends on an imaginary plane V2 that extends in a direction perpendicular to the extension direction of the mounting groove 23 when viewed from the mounting direction of the gasket 30, and that extends in a manner that includes the first linear portion 31.

[0033] According to this embodiment, it is possible to confirm that the first linear portion 31 and the second linear portion 51 are aligned in a direction perpendicular to the extension direction of the mounting groove 23, i.e., a direction that is easy to see visually, so that the gasket 30 can be easily positioned.

[0034] (3) The cover body 20 has a pair of sub-linear portions 52, 53. The pair of sub-linear portions 52, 53 are provided at positions sandwiching the second linear portion 51 on the inner peripheral surfaces of the side wall 20b and the flange portion 20c. The pair of sub-linear portions 52, 53 form lines extending in the same direction as the mounting direction of the gasket 30. According to this embodiment, in addition to indicating the target mounting position of the gasket 30 by the second linear portion 51, the pair of sub-linear portions 52, 53 sandwiching the second linear portion 51 therebetween can indicate the allowable range of the mounting position of the gasket 30. Therefore, the position serving as an index for positioning the gasket 30 can be indicated with a high degree of freedom.

[0035] (4) The mark convex portion 50 has a two-step shape, with the portion sandwiched between one of the pair of sub-linear portions 52, 53 and the second linear portion 51 being a lower step portion 55, and the portion sandwiched between the other of the pair of sub-linear portions 52, 53 and the second linear portion 51 being an upper step portion 56.

[0036] According to this embodiment, the ridge lines of three corners of the two-step marker protrusion 50 can be made into the second linear portion 51 and the pair of sub-linear portions 52, 53. This makes it possible to clearly show the second linear portion 51 and the pair of sub-linear portions 52, 53 as lines with no width on the inner circumferential surfaces of the side wall 20b and the flange portion 20c.

[0037] (5) The first linear portion 31 is a bending ridgeline at a bent portion of the gasket 30. According to this embodiment, in the gasket 30 having a bent portion, the bending ridgeline at the bent portion can be used as the first linear portion 31 that serves as an index for positioning the gasket 30.

[0038] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0039] The width of the lower step portion 55 and the width of the upper step portion 56 constituting the mark protrusion 50 can be set arbitrarily. In short, the widths can be set in such a manner that the second linear portion 51 indicates the target mounting position of the gasket 30, and the pair of sub-linear portions 52, 53 can indicate the allowable range of the mounting position of the gasket 30.

[0040] The shape of the mark protrusion 50 can be changed as desired as long as it can indicate the second linear portion 51 and the pair of sub-linear portions 52, 53. As the shape of such a mark protrusion 50, for example, (Configuration A) or (Configuration B) described below can be adopted.

[0041] (Configuration A) As shown in Fig. 8, the shape of the mark protrusion 60 can be a pentagonal cross-section that extends in the mounting direction of the gasket 30 (the direction perpendicular to the paper surface in Fig. 8). In this example, the base end portion of the mark protrusion 60 has a rectangular cross-section, and the tip portion of the mark protrusion 60 has a triangular cross-section.

[0042] With this configuration, the ridge lines of the three corners of the tip portion having a triangular cross section can be made into three linear portions (specifically, a second linear portion 61 and a pair of sub-linear portions 62, 63) that extend in the same direction as the installation direction of the gasket 30.

[0043] (Configuration B) As shown in FIG. 9, the shape of the mark protrusion 70 can be formed to have a groove 75 with a V-shaped cross section on the top surface thereof that extends in the same direction as the mounting direction of the gasket 30. With this configuration, the portion corresponding to the bottom of the V-shaped groove 75 can be made into the second linear portion 71, and the ridge lines corresponding to both opening ends of the V-shaped groove 75 can be made into a pair of sub-linear portions 72, 73.

[0044] Instead of providing the marking protrusions 50 on the inner peripheral surfaces of the side wall 20b and the flange portion 20c, recesses may be provided to indicate the three linear portions 51, 52, and 53. As the recesses, for example, a recess having a cross section in the shape of a two-step staircase may be used.

[0045] It is also possible to provide a combination of a convex portion and a concave portion on the inner peripheral surface of the side wall 20b and the flange portion 20c to represent the three linear portions 51, 52, and 53. In this configuration, for example, a staircase portion having a concave portion constituting a lower step of a two-step staircase and a convex portion constituting an upper step of the two-step staircase can be provided.

[0046] 10, the side wall 20b and the inner peripheral surface of the flange portion 20c may be provided with a first colored portion 85 colored with a first color (e.g., red) and a second colored portion 86 colored with a second color (e.g., blue) different from the first color. In this example, the first colored portion 85 and the second colored portion 86 are adjacent to each other and extend in the same direction as the mounting direction of the gasket 30.

[0047] According to this configuration, a portion corresponding to the boundary between the first colored portion 85 and the second colored portion 86 can be shown as a second linear portion 81. In addition, an end portion of the first colored portion 85 opposite the boundary and an end portion of the second colored portion 86 opposite the boundary can be shown as a pair of sub-linear portions 82, 83.

[0048] The positions of the mark protrusion 50 and the first linear portion 31 are not limited to being located near the boundary between the first recess 25 and the base 24, but may be located at any position. An example of the above configuration is shown in FIG. 11. As shown in FIG. 11, the gasket 90 has a slip-prevention protrusion 97. The slip-prevention protrusion 97 is provided on a gasket base 94, which is a portion of the gasket 90 that is attached to the base 24. The slip-prevention protrusion 97 has a substantially triangular cross section on the outer surface of the gasket base 94 and extends in the same direction as the attachment direction of the gasket 90 (the direction perpendicular to the paper surface in FIG. 11). In this example, the ridge line of the tip of the slip-prevention protrusion 97 forms the first linear portion. The mark protrusion 100 having the second linear portion 101 and a pair of sub-linear portions 102, 103 is provided in a manner protruding inwardly at a portion of the inner peripheral surface of the side wall 20b and the flange portion 20c of the cover body 20 that corresponds to the inner peripheral side of the base 24. In this example, when the gasket 30 is fitted into the mounting groove 23 in the correct position, the first linear portion (more specifically, the above-mentioned ridge line) of the anti-slip protrusion 97 and the second linear portion 101 of the marker protrusion 100 are aligned in a direction perpendicular to the extension direction of the mounting groove 23 (the up and down direction in Figure 11) when viewed from the mounting direction of the gasket 30.

[0049] In order to prevent misalignment at the mounting groove 23 and the bent portion of the gasket 90, it is preferable that the marking protrusion 100 and the slip-out prevention protrusion 97 are disposed at the bent portion of the side wall 20b and the flange portion 20c or in the vicinity of the bent portion. The bent portion corresponds to, for example, the boundary portion between the first recessed portion 25 and the base portion 24.

[0050] The first linear portion 31 is not limited to the bend ridgeline of the bent portion of the gasket 30, but may be any portion having a characteristic shape different from other portions. For example, as shown in Fig. 12, the first linear portion 111 may be a portion corresponding to the parting line of the mold device used to manufacture the gasket 110, more specifically, a parting line 117 formed in the same portion.

[0051] The mark protrusions 50 may be provided on the outer circumferential surfaces of the side wall 20b and the flange portion 20c. The mark protrusion 50 may be provided in multiple locations, such as near the boundary between the first recess 25 and the base 24, or near the boundary between the second recess 26 and the base 24.

[0052] The pair of sub-linear portions 52, 53 may be omitted. The position of the second linear portion 51 may be determined so that the positions of the first linear portion 31 and the second linear portion 51 satisfy the following relationship when the gasket 30 is fitted in the mounting groove 23 at the correct position. That is, in this case, the first linear portion 31 and the second linear portion 51 are aligned in a direction that is not perpendicular to the extension direction of the mounting groove 23 and that intersects with the extension direction when viewed from the mounting direction of the gasket 30.

[0053] Even in this configuration, as in the above embodiment, by utilizing the first linear portion 31 and the second linear portion 51, the gasket 30 can be positioned without changing the shape of the gasket 30 or the shape of the mounting groove 23.

[0054] The positioning assistance structure according to the above embodiment is not limited to application to a cylinder head cover having a gasket with a generally rectangular cross-section, but can also be applied to a cylinder head cover having a gasket with any cross-sectional shape, such as a circular or elliptical cross-section.

[0055] In the above configuration, the first linear portion of the gasket may be non-linear (e.g., a curved line) when viewed from the mounting direction of the gasket. In this case, the positions of the first linear portion and the second linear portion may be set such that the imaginary plane V2 includes a part of the first linear portion and the second linear portion of the cover body extends on the imaginary plane V2. This allows the gasket to be positioned relative to the cover body by a simple task of aligning a specific portion of the first linear portion (e.g., a portion furthest from the cover body) with the second linear portion.

[0056] The positioning assistance structure according to the above embodiment is not limited to application to a cylinder head cover having a mounting groove in the form of a bottomed rectangular groove, but can also be applied to a cylinder head cover having a mounting groove of any groove shape, such as a groove shape with a U-shaped cross section.

[0057] The positioning assistance structure according to the above embodiment can be applied to a cylinder head cover, as well as to a chain cover of an internal combustion engine, or to an intake manifold formed by assembling a plurality of divided bodies together.

[0058] <Additional Notes> The above embodiment includes the configurations described in the following supplementary notes. [Appendix 1] A positioning assistance structure that assists in positioning a gasket to a target component, wherein the gasket has a predetermined non-circular annular shape when not mounted, and has a first linear portion that extends linearly on an outer surface of the gasket in a direction intersecting the extension direction of the gasket, and the target component extends in a manner to form the predetermined non-circular annular shape, and has a mounting groove into which the gasket is fitted, and a second linear portion that is provided on an outer surface of a wall portion extending along the mounting groove, and is aligned with the first linear portion in a direction intersecting the extension direction of the mounting groove when the gasket is fitted into the mounting groove in the correct position, and the positioning assistance structure.

[0059] [Appendix 2] The positioning assistance structure described in [Appendix 1], wherein the second linear portion is a surface extending in a direction perpendicular to the extension direction of the mounting groove when viewed from the mounting direction, and extends in a manner that includes at least a portion of the first linear portion.

[0060] [Appendix 3] The attachment target component has a step portion having a stepped shape in which one side portion protrudes more than the other side portion, with the second linear portion as the boundary, providing a positioning assistance structure as described in [Appendix 1] or [Appendix 2].

[0061] [Appendix 4] A positioning assistance structure described in [Appendix 1] or [Appendix 2], having a pair of sub-linear portions provided at positions sandwiching the second linear portion on the outer surface of the wall portion and forming a line extending in the same direction as the installation direction.

[0062] [Appendix 5] The attachment target member has a two-step staircase portion, with a lower step being the portion sandwiched between one of the pair of sub-linear portions and the second linear portion, and an upper step being the portion sandwiched between the other of the pair of sub-linear portions and the second linear portion, as described in [Appendix 4].

[0063] [Appendix 6] The positioning assistance structure described in any one of [Appendix 1] to [Appendix 5], wherein the first linear portion is a bending ridge line in a bending portion of the gasket. [Explanation of symbols]

[0064] 10…Cover 20…Cover body 20a...Top wall 20b…Side wall 20c…Flange section 21…Mounting part 22...Bolt hole 23...Mounting groove 24...Base 25…First recess 26…Second recess 30, 90, 110…Gasket 31,111...First linear part 34,94…Gasket base 35…First bend 36…Second bend 40…Cylinder head 42…Bolt hole 45...first protrusion 45a...Through hole 45b...Through hole 46…Second protrusion 46a...Through hole 50, 60, 70, 100…Marking protrusions 51,61,71,81,101…Second linear part 52, 62, 72, 82, 102...Sub-line section 53, 63, 73, 83, 103...Sub-linear section 55…Lower section 56…Upper section 75...Groove 85...1st coloring section 86...Second coloring section 97…Protruding part to prevent slipping out 117…Parting line

Claims

1. A positioning assistance structure that assists in positioning a gasket to an attachment target member, The gasket has a predetermined shape that is a noncircular annular shape when not attached, and has a first linear portion that extends linearly on an outer surface of the gasket in a direction intersecting an extension direction of the gasket, The attachment target member is An attachment groove extending in the predetermined shape, which is a non-circular annular shape, and into which the gasket is fitted; a second linear portion provided on the outer surface of a wall portion extending along the mounting groove, and which is aligned with the first linear portion in a direction intersecting the extension direction of the mounting groove when the gasket is fitted into the mounting groove in the correct position, and which forms a line extending in the same direction as the mounting direction of the gasket.

2. The second linear portion is a surface extending in a direction perpendicular to the extension direction of the mounting groove when viewed from the mounting direction, and extends in the surface extending in a manner including at least a portion of the first linear portion. The positioning assistance structure according to claim 1 .

3. The attachment target member has a stepped portion having a stepped shape in which a portion on one side protrudes more than a portion on the other side with the second linear portion as a boundary. The positioning assistance structure according to claim 1 or 2.

4. a pair of sub-linear portions provided on an outer surface of the wall portion at positions sandwiching the second linear portion therebetween and extending in the same direction as the mounting direction; The positioning assistance structure according to claim 1 or 2.

5. The attachment target member has a two-step staircase portion, with a portion sandwiched between one of the pair of sub-linear portions and the second linear portion as a lower step portion, and a portion sandwiched between the other of the pair of sub-linear portions and the second linear portion as an upper step portion. The positioning assistance structure according to claim 4 .

6. The first linear portion is a bending ridge line in a bending portion of the gasket. The positioning assistance structure according to claim 1 or 2.

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