JP7587273B2 - Gasket and manufacturing method thereof - Google Patents

Description

The present invention relates to a gasket that is attached between two members, a first member and a second member, which are joined together, and a method for manufacturing the same.

Annular gaskets have been known for some time that are attached between two various components, such as between the heat exchanger cover and heat exchanger of an internal combustion engine, or between the cylinder block and oil pan, and that seal between the opposing surfaces of the two components by fastening the two components together. Such gaskets are composed of a rigid annular core portion and a sealing portion made of an elastic material such as a thermoplastic resin or rubber.

It is known that the gasket described above is manufactured by insert molding the core body with an adhesive applied thereto, or by insert molding the core body with a through hole (pierced hole) filled with a sealing material, in order to integrally join the core body and the seal part. However, when applying an adhesive to the core body to join the seal part, the adhesive is expensive and a process of applying the adhesive is required. In addition, forming a through hole in the core body requires a die that forms a through hole at the same time as punching a metal plate to manufacture the core body, or a process of forming a through hole in a post-processing after punching a metal plate to manufacture the core body. Therefore, when forming a through hole at the same time as the core body using a die, the die may become complicated and the cost may increase. In addition, even when forming a through hole in the core body by post-processing, the number of processes may increase due to the post-processing, which may result in an increase in costs.

The following Patent Document 1 discloses a gasket made entirely of rubber that is attached to a sheet metal cover. It describes a structure in which a protrusion is provided on the cover, the tip of the protrusion is deformed so as to expand from the base, and a gasket is provided there, so that the gasket does not easily come off the protrusion without using adhesive.
The following Patent Document 2 discloses a method for manufacturing a seal structure provided in a resin-based separator used as a sealing means for a fuel cell, which describes a manufacturing method in which protruding parts protruding from groove shoulders on both sides of a gasket retaining groove are plastically deformed by clamping a molding die so that they protrude toward the gasket retaining groove, and then a seal material is filled into the cavity.

JP 2002-106719 A Patent No. 5126472

In the gasket disclosed in Patent Document 1, the gasket itself attached to the protrusion has a sealing function, and in the resin-based separator disclosed in Patent Document 2, the gasket formed in the gasket retaining groove has a sealing function. Therefore, it is difficult to directly apply the configurations disclosed in Patent Documents 1 and 2 to a structure in which a portion having a sealing function is sandwiched between the opposing surfaces of two members and both sides of the core are sealed.

The present invention was made in consideration of the above circumstances, and aims to provide a gasket in which the core and sealing parts are firmly integrated while maintaining the original sealing performance between two components, and a manufacturing method thereof.

In order to achieve the above object, the gasket of the present invention is a gasket that is attached between two members, a first member and a second member, which are joined together, and includes an annular core portion and a seal portion made of an elastic material that is molded integrally with the core portion. The core portion includes a core body portion that is sandwiched between the opposing surfaces of the two members, a first concave joint groove, a second concave joint groove formed adjacent to the first joint groove, and a convex wedge portion formed on the groove shoulder of the first joint groove on the second joint groove side and protruding toward the opening of the first joint groove. The seal portion includes a seal body portion that seals between the opposing surfaces of the two members, and a joint portion formed by filling the elastic material up to the openings of the first joint groove and the second joint groove.

In order to achieve the above object, the manufacturing method of the gasket of the present invention is a manufacturing method of a gasket that is attached between two members, a first member and a second member, which are joined together, and has an annular core portion and a seal portion made of an elastic material that is insert-molded into the core portion, and the core portion has a core body portion that is sandwiched between the opposing surfaces of the two members, a concave first joint groove, a concave second joint groove formed adjacent to the first joint groove, and a protruding wedge portion that is in an upright state formed on the groove shoulder of the first joint groove on the second joint groove side, and is characterized by having a bending deformation process in which the wedge portion is bent toward the opening side of the first joint groove and arranged so that the wedge portion covers the opening portion, and a molding process in which a molding material is filled into the cavity of a molding die on which the core portion is placed, the seal portion is molded, and the molding material is filled up to the openings of the first joint groove and the second joint groove to integrally mold the joint portion.

The gasket of the present invention has the above-mentioned structure, so that the core portion and the seal portion are firmly integrated while maintaining the original sealing performance of sealing between two components.

In addition, because the manufacturing method of the gasket of the present invention has the above-mentioned configuration, it is possible to obtain a gasket in which the core portion and the sealing portion are firmly integrated while maintaining the original sealing performance of sealing between components.

1A is a schematic plan view of a gasket according to an embodiment of the present invention, and FIG. 1B is a schematic enlarged view of a portion X in FIG. 1(a) is a cross-sectional view taken along line Y-Y' in FIG. 1(b), and FIG. 1(b) is a schematic longitudinal cross-sectional view in a state where a gasket is attached between a first member and a second member in FIG. 1A is a schematic vertical cross-sectional view of a core body part placed in a molding die, FIG. 1B is a schematic plan view of a main part of the core body part, FIG. 1C is a schematic perspective view of the core body part, and FIG. 1D is a schematic enlarged view of part Z in FIG. 1A. 3A is a schematic vertical cross-sectional view of the molding die of FIG. 3A in a clamped state, and FIG. 3B is a schematic vertical cross-sectional view of the molding die of FIG. 3A in a clamped state, and FIG. 3B is a schematic vertical cross-sectional view of the molding die of FIG. 3A in a clamped state, and FIG. 3B is a schematic vertical cross-sectional view of the molding die of FIG. 3A in a clamped state. 5A to 5D are schematic vertical cross-sectional views of gaskets according to other embodiments of the present invention. 1A is a schematic plan view of a core portion used in a gasket according to yet another embodiment of the present invention, and FIG. 1B is a schematic plan view of a gasket in which a seal portion is joined to the core portion of FIG.

The following describes an embodiment of the present invention with reference to the drawings. Note that in some drawings, some of the reference numerals used in other drawings are omitted.

<Gasket>
The gasket 1 shown in Figures 1 and 2 is attached between two members, a first member 4 and a second member 5, which are joined together, and includes an annular core portion 2 and a seal portion 3 made of an elastic material that is molded integrally with the core portion 2. The core portion 2 includes a core body portion 20 that is sandwiched between the opposing surfaces 4a, 5a of the two members, a concave first joint groove 23, and a concave second joint groove 24 formed adjacent to the first joint groove 23. The core portion 2 further includes a convex wedge portion 25 that is formed on the groove shoulder of the first joint groove 23 on the second joint groove 24 side and protrudes toward the opening portion 23a of the first joint groove 23. The seal portion 3 includes a seal body portion 30 that seals between the opposing surfaces 4a, 5a of the two members, and a joint portion 31 that is formed by filling the elastic material up to the opening portions 23a, 24a of the first joint groove 23 and the second joint groove 24.
In the present specification, the gasket 1 will be described with the first member 4 side being the upper side and the second member 5 side being the lower side in a state where the gasket 1 is attached between two members.

In this embodiment, the first member 4 is a member disposed above the second member 5. Examples of the first member 4 and the second member 5 include a heat exchanger cover and exchanger of an internal combustion engine, a cylinder block, and an oil pan. The gasket 1 of this embodiment is a member that seals between the opposing surface 4a of the first member 4 and the opposing surface 5a of the second member 5 as described above. The shape of the gasket 1 in a plan view shown in FIG. 1(a) is made to conform to the shapes of the opposing surfaces 4a, 5a of the first member 4 and the second member 5.

The gasket 1 shown in FIG. 1(a) comprises an annular core portion 2 and a seal portion 3 made of an elastic material integrally molded with the core portion 2. The core portion 2 is formed by punching a plate material of a metal material having rigidity, such as a cold-rolled steel plate or a stainless steel plate, or by injection molding using a thermoplastic resin material. The seal portion 3 is integrally molded on the inner peripheral surface 2a side of the core portion 2. The inner peripheral surface 2a side of the upper surface 20a and the lower surface 20b of the core body main body portion 20, which is sandwiched between the opposing surfaces 4a and 5a of the two members, has notched step portions 21, 21 formed in a notched shape toward the center side in the vertical direction (thickness direction) of the core portion 2. In addition, a plurality of joining recesses 22 extending outward from the notched step portions 21 are provided at appropriate positions on the upper surface 20a. At appropriate positions on the core body main body 20, multiple bolt holes 26 are provided that penetrate vertically for assembling the first member 4 and the second member 5 with bolts that serve as fasteners.

As shown in FIG. 1(b), which is an enlarged view of the X portion in FIG. 1(a), the joining recess 22 is provided with two first joining grooves 23, 23 and a second joining groove 24. The first joining groove 23 is a recess recessed further downward from the notched step portion 21, and its opening portion 23a extends along the circumferential direction of the core body main body portion 20 and has a rectangular shape with rounded corners in a plan view. The bottom surface 23b of the first joining groove 23 has a rectangular shape with rounded corners that is slightly smaller than the opening portion 23a in a plan view. The two first joining grooves 23, 23 are arranged side by side with a gap in the width direction perpendicular to the circumferential direction of the core body main body portion 20. The first joining groove 23 on the inner circumferential side is disposed adjacent to the notched step portion 21, and the first joining groove 23 on the outer circumferential side is formed along the edge portion on the outer circumferential side of the joining recess 22 and is disposed adjacent to the upper surface 20a of the core body main body portion 20. Between the first joining grooves 23, 23, a concave second joining groove 24 adjacent to the first joining groove 23, 23 is provided. The second joining groove 24 is provided substantially flush with the notched step portion 21. In addition, a wedge portion 25, 25 formed by bending a plate body so as to cover the opening portion 23a, 23a of the first joining groove 23, 23 is formed on the groove shoulder of the first joining groove 23, 23 on the second joining groove 24 side. In this embodiment, the other surface (lower surface) 25b of the wedge portion 25 is bent at an angle close to a right angle to the inner side wall 23c of the first joining groove 23. That is, in this embodiment, the wedge portion 25 adjacent to the first joining groove 23 on the inner circumference side is bent toward the inner circumference side, and the wedge portion 25 adjacent to the first joining groove 23 on the outer circumference side is bent toward the outer circumference side. In addition, the wedge portion 25 is formed so that its tip portion 25d is located at approximately the center of the groove width of the first joining groove 23. The wedge portion 25 is disposed at approximately the center of the longitudinal direction of the first joining groove 23, and its longitudinal dimension is shorter than the longitudinal dimension of the first joining groove 23.

The seal portion 3 is made of an elastic material and is integrally molded and fixed to the core portion 2. Examples of elastic materials include rubber materials such as EPDM, NBR, H-NBR, ACM, AEM, and FKM. The elastic material constituting the seal portion 3 is not limited to the above-listed materials or rubber materials, and may be a resin material having elasticity, etc., and may be selected appropriately according to the design.

The inner circumferential side of the seal portion 3 has a seal body portion 30 that seals between the opposing surfaces 4a, 5a of the first member 4 and the second member 5. This seal body portion 30 is provided along the inner circumferential surface 2a of the core portion 2 and is formed to protrude in the vertical direction from the upper surface 20a and the lower surface 20b of the core body portion 20 (see FIG. 2(a)). When the gasket 1 is assembled to the first member 4 and the second member 5, the seal body portion 30 contacts the opposing surfaces 4a, 5a and elastically deforms to seal between the opposing surfaces 4a, 5a (see FIG. 2(b)).

The seal portion 3 is fixed to the notched step portions 21, 21 provided on the upper surface 20a and the lower surface 20b of the core body main body portion 20. Furthermore, the seal portion 3 has a joint portion 31 in which an elastic material is filled up to the opening portions 23a, 23a of the first joint grooves 23, 23 and the opening portion 24a of the second joint groove 24. The joint portion 31 in the first joint groove 23 is filled up to the opening portion 23a by filling the elastic material between the bottom surface 23b of the first joint groove 23 and the other surface 25b of the wedge portion 25. As shown in FIG. 2(a), which is a cross-sectional view taken along the line Y-Y' in FIG. 1, the seal portion 3 in the portion other than the seal body portion 30 is configured to be approximately flush with the upper surface 20a, the lower surface 20b of the core body main body portion 20 and one surface (upper surface) 25a of the wedge portion 25.

In this embodiment, the core portion 2 is made of a metal material or a thermoplastic resin material, and the wedge portion 25 is formed by bending, so that the wedge portion 25 can be easily formed. The wedge portion 25 is also formed by bending so as to cover the opening portion 23a of the first joining groove 23. The elastic material is filled between the bottom surface 23b of the first joining groove 23 and the other surface 25b of the wedge portion 25. Therefore, since the wedge portion 25 covers the elastic material present in the first joining groove 23, the joining portion 31 is suppressed from peeling off from the inside of the first joining groove 23. Furthermore, since the elastic material spreads to the opening portion 23a of the first joining groove 23 and the opening portion 24a of the second joining groove 24 to form the joining portion 31, the core portion 2 and the seal portion 3 are firmly integrated. In this way, the gasket 1 of this embodiment maintains the original sealing performance of sealing between two members as shown in FIG. 2(b), while the core body part 2 and the seal part 3 are firmly integrated. In addition, the seal part 3 is also filled and fixed to the cutout step parts 21, 21 of the upper surface 20a and the lower surface 20b of the core body main body part 20, so that the core body part 2 and the seal part 3 are more firmly integrated. In addition, the circumference of the folded base part 25c of the wedge part 25 is filled with the seal part 3, and one surface (upper surface) 25a is approximately flush with the seal part 3, so that the concentration of stress on the wedge part 25 is suppressed when the gasket 1 is attached between the first member 4 and the second member 5. In addition, one surface (upper surface) 25a of the wedge part 25 is not covered with an elastic material and is exposed from the seal part 3. As shown in FIG. 1(a), the gasket 1 of this embodiment has four joints 31 filled into the joint recess 22 and spaced apart in the circumferential direction.

<Production Method>
Next, a method for manufacturing the gasket 1 shown in FIGS. 1 and 2 will be described with reference to FIGS.
The gasket 1 is manufactured by insert molding the seal portion 3 made of an elastic material into the core portion 2. In this manufacturing process, the wedge portion 25 before the bending deformation process described later is a raised convex portion formed on the groove shoulder of the first joining groove 23 of the core portion on the side of the second joining groove 24. This wedge portion is bent toward the opening portion 23a of the first joining groove 23, and the wedge portion 25 is arranged so as to cover the opening portion 23a (bending deformation process). Then, a molding material is filled into the cavity 130 of the molding die 100 on which the core portion 2 is placed, and the seal portion 3 is molded, and the molding material is filled up to the opening portions 23a and 24a of the first joining groove 23 and the second joining groove 24 to integrally mold the joining portion 31 (molding process).
The manufacturing method of the gasket 1 will be described in detail below. In the wedge portion 25 in the standing state shown in Figures 3(a) to 3(d), the surface on the second joining groove 24 side is one surface 25a, and the surface on the first joining groove 23 side is the other surface 25b. After the bending deformation process, the one surface 25a of the wedge portion 25 faces upward, and the other surface 25b faces downward.

3(a) to (d), the core body 2 used in the manufacturing method of this embodiment has a convex wedge portion 25 in an upright state formed on the groove shoulder of the first joining groove 23 of the core body 2 on the second joining groove 24 side. The wedge portion 25 is a plate body, and one surface 25a thereof is inclined toward the adjacent first joining groove 23 side from the base 25c to the tip 25d. The other surface 25b of the wedge portion 25 is configured to be approximately flush with the inner wall 23c of the first joining groove 23 and is approximately perpendicular to the bottom surface 23b of the first joining groove 23. In other words, the wedge portion 25 is formed such that the inclination from the base 25c to the tip 25d of the one surface 25a on the second joining groove 24 side is greater than the inclination from the base 25c to the tip 25d of the other surface 25b on the first joining groove 23 side. 3(a) to 3(d), the tip 25d of the wedge portion 25 has a curved shape on one side 25a that slopes upward toward the adjacent first joining groove 23, and a flat shape on the other side 25b. Also, as shown in 3(b) and 3(c), the wedge portion 25 is disposed at approximately the center of the first joining groove 23 in the longitudinal direction, and its longitudinal dimension is shorter than the longitudinal dimension of the first joining groove 23.

The molding die 100 is composed of an upper die 110 and a lower die 120. The upper die 110 and the lower die 120 are provided with cavity surfaces 111, 121 that form a cavity 130 when clamped. The upper die 110 is formed with a gate portion 112 that is connected to the cavity surface 111 for supplying molding material r from the outside into the cavity 130. The upper die 110 and the lower die 120 are arranged so that their respective cavity surfaces 111, 121 face each other. The cavity 130 is a space that is filled with the molding material, and its shape follows the shape of the seal portion 3.

Next, each step for manufacturing the gasket 1 will be described.
In the bending deformation process, the core portion 2 is first placed on the cavity surface 121 of the lower mold 120 (see FIG. 3A). Then, the upper mold 110 and the lower mold 120 are clamped together. At this time, the tip portion 25d of the wedge portion 25 abuts against the cavity surface 111 of the upper mold 110, and as the clamping process progresses, the upright wedge portion 25 is bent toward the opening portion 23a of the adjacent first joint groove 23 by the pressure of the upper mold 110 (bending deformation process). When the clamping process is completed, the other surface 25b of the wedge portion 25 is bent at an angle close to a right angle to the inner wall 23c of the first joint groove 23 (see FIG. 4A).

3(d), the wedge portion 25 is formed such that the inclination from the base 25c to the tip 25d of the one surface 25a on the second joining groove 24 side is greater than the inclination from the base 25c to the tip 25d of the other surface 25b on the first joining groove 23 side. Therefore, the wedge portion 25 is easily bent and deformed toward the opening portion 23a of the adjacent first joining groove 23 by the pressure of the upper mold 110 in the bending deformation process. Furthermore, the tip 25d of the wedge portion 25 has a curved shape on the one surface 25a side that is inclined upward toward the adjacent first joining groove 23 side, and a flat shape on the other surface 25b side. Therefore, when the upper mold 110 comes into contact with the tip 25d of the wedge portion 25 and starts bending the wedge 25, it slides smoothly along the curved surface 25a, making it easier to bend and deform the wedge portion 25 more reliably toward the opening portion 23a of the first joining groove 23.

The wedge portion 25 of the core portion 2 is bent and deformed by the bending deformation process, and the cavity 130 is formed by clamping the mold, and then the molding process is performed. In the molding process, molding material r from the outside is injection molded into the cavity 130 through the gate portion 112. This molding material r is an unvulcanized elastic material with fluidity. When the molding material r is filled into the cavity 130, the molding material is filled up to the opening positions 23a, 23a, 24a of the first joining grooves 23, 23 and the second joining groove 24. Since the wedge portion 25 does not completely close the opening position 23a but covers a part of it, the molding material r flows into the first joining groove 23 from the places not covered by the wedge portion 25 and fills it. After the molding material r filled in the cavity 130 is vulcanized, the mold is opened and released, and the excess elastic material vulcanized in the gate portion 112, etc. is cut off, thereby producing the gasket 1 shown in FIG. 1, etc., in which the core portion 2 and the seal portion 3 are integrally molded. In the molding process, the molding material r is filled up to the opening portions 23a, 24a of the first and second joint grooves 23 and 24, so that the joint portion 31 is molded at the same time as the seal portion 3 is molded.

According to the above-mentioned manufacturing method, the bending deformation process bends the standing wedge portion 25 to provide a bent wedge portion 25 that covers the opening portion 23a of the first joint groove 23. The bent wedge portion 25 prevents the joint portion 31 of the seal portion 3 from falling off the core portion 2, and strengthens the core portion 2 and the seal portion 3 as a single unit. In addition, in the bending deformation process of this embodiment, the standing wedge portion 25 is bent and deformed by the pressure of the upper mold 110 when the mold is closed, so that the wedge portion 25 that firmly integrates the core portion 2 and the seal portion 3 can be provided without increasing the number of steps in the manufacturing process.

In the molding process, the molding material r for forming the seal portion 3 is filled up to the openings 23a, 24a of the first and second joint grooves 23, 24, and the joint portion 31 is molded as a single unit. This eliminates the need to provide piercing holes in the core portion 2, which are difficult to control for tolerance, as in the past, and makes it possible to obtain a gasket 1 in which the core portion 2 and the seal portion 3 are firmly integrated while maintaining the original sealing performance. In addition, since there is no need to use adhesive, even combinations of different materials that are difficult to mold together because they are difficult to bond can be insert molded together, and the freedom in selecting materials for the core portion 2 and the seal portion 3 is improved without increasing the manufacturing process.

In the above-mentioned manufacturing method, the wedge portion 25 in the standing state is bent and deformed by the pressure of the upper mold 110 when the mold is closed, but the wedge portion 25 may be bent and formed by other methods. In the above-mentioned molding process, the molding material r, which is an unvulcanized elastic material, is injection molded from the gate portion 112, but the molding method is not limited to this, and the core portion 2 and the seal portion 3 may be integrally insert molded by various molding methods. In addition, the molding material r may be selected according to the selected molding method, and the molding die 100 may be selected according to the selected molding method. For example, if the molding method does not require the gate portion 112, the molding die 100 without the gate portion 112 is selected. In addition, the molding die 100 is not limited to one that uses two dies such as the upper mold 110 and the lower mold 120 of this embodiment. In addition, according to the manufacturing method of this embodiment, the application of adhesive or the like to the core portion 2 is not required, but this is not excluded, and the application of adhesive to the core portion 2 may be performed before the bending and deformation process. When the adhesive is applied to the core portion 2, the adhesive accumulates on the bottom surface 23b of the first bonding groove 23, ensuring a thick adhesive layer. In addition, during the bending deformation process, the upper mold 110 is unlikely to come into direct contact with the adhesive layer formed in the first bonding groove 23 or the second bonding groove 24, so the thickness of the adhesive layer is unlikely to be damaged, and improved adhesion after the molding process can be expected.

<Gasket according to another embodiment>
Next, gaskets according to other embodiments will be described with reference to Fig. 5. Figs. 5(a) to (d) are schematic vertical cross-sectional views of the respective embodiments corresponding to Fig. 2(a) (a cross-sectional view taken along line Y-Y' in Fig. 1(b)). In the following description, the configuration and effects of parts common to the gasket 1 of the first embodiment shown in Figs. 1 and 2 will be omitted.

The gasket 1A shown in FIG. 5(a) differs from the gasket 1 of the first embodiment in that the upper surface 20a and the lower surface 20b of the core body 20 are provided with cutout steps 21, 21, and the seal portion 3 is integrally molded on the outer circumferential surface 2b side of the core body 2, and the configuration of the other parts is substantially the same as that of the first embodiment. Even though the seal portion 3 is provided on the outer circumferential surface 2b side of the core body 2, the gasket 1A can seal between the opposing surfaces 4a, 5a of the first member 4 and the second member 5.

In the gasket 1B shown in Fig. 5(b), the first joint grooves 23, 23, the second joint grooves 24, and the wedge portions 25, 25 are formed on the upper surface 20a of the core body main body portion 20 facing the opposing surface 4a of the first member 4 and on the lower surface 20b of the core body main body portion 20 facing the opposing surface 5a of the second member 5. Furthermore, an elastic material is filled up to the opening portions 23a, 23a of the first joint grooves 23, 23 on the upper surface 20a side, and an elastic material is filled from the opening portions 23a, 23a of the first joint grooves 23, 23 on the lower surface 20b side to the bottom surfaces 23b, 23b. Therefore, since joint portions 31, 31 are formed on each of the upper surface 20a and the lower surface 20b, the joint between the core body portion 2 and the seal portion 3 is stronger. The gasket 1B shown in FIG. 5(b) is substantially similar in configuration to that of the first embodiment, except that the first joining grooves 23, 23, the second joining groove 24, the wedge portions 25, 25, and the joining portion 31 are formed on the underside 20b of the core portion 2.

The gasket 1C shown in FIG. 5(c) has a configuration in which the first joining groove 23 and the wedge portion 25 are formed on the inner circumference side of the gasket 1 of the first embodiment, and the first joining groove 23 and the wedge portion 25 are not formed on the outer circumference side of the gasket 1 of the first embodiment. In addition, the groove width of the second joining groove 24 is formed smaller than that of the first embodiment. The gasket 1C shown in FIG. 5(c) has a configuration in which the parts other than the first joining groove 23, the second joining groove 24, and the wedge portion 25 are substantially the same as those of the first embodiment. Even if there is only one first joining groove 23 and one wedge portion 25, the wedge portion 25 suppresses peeling of the joining portion 31, and the core portion 2 and the seal portion 3 are firmly integrated. Note that the gasket 1 of the first embodiment may have a configuration in which the first joining groove 23 and the wedge portion 25 are formed on the outer circumference side instead of the inner circumference side.

The core body 2 of the gasket 1D shown in FIG. 5(d) has a shape in which the core body 2 of the gasket 1 of the first embodiment is divided along the circumferential center. In the gasket 1D shown in FIG. 5(d), the core body 2 is composed of two members, a first core body 2A and a second core body 2B. The first core body 2A is disposed on the inner circumferential side of the second core body 2B and is adjacent to the second core body 2B via the seal portion 3.

The first core portion 2A and the second core portion 2B are each formed in an annular shape. The first core portion 2A has notched step portions 21, 21 formed on the upper surface 20a and the lower surface 20b on the outer peripheral surface 2Ab side, and the second core portion 2B has notched step portions 21, 21 formed on the upper surface 20a and the lower surface 20b on the inner peripheral surface 2Ba side. The notched step portions 21, 21 in the portions adjacent to the first joining groove 23 of the first core portion 2A and the second core portion 2B function as the second joining groove 24. The wedge portions 25, 25 are formed on the groove shoulders of the first joining grooves 23, 23 of the first core portion 2A and the second core portion 2B, respectively. The wedge portion 25 of the first core portion 2A is formed on the groove shoulder on the outer periphery side (second joining groove 24 side) of the first joining groove 23 and is bent inward to cover the opening portion 23a of the first joining groove 23. The wedge portion 25 of the second core portion 2B is formed on the groove shoulder on the inner periphery side (second joining groove 24 side) of the first joining groove 23 and is bent outward to cover the opening portion 23a of the first joining groove 23.

The seal portion 3 has a seal body 30 formed at approximately the center between the first core portion 2A and the second core portion 2B. The seal body 30 has two protruding portions 30a, 30a that protrude in the vertical direction from the upper surface 20a and the lower surface 20b of the core portion 2, and a recess 30b with a bottom provided between the two protruding portions 30a, 30a. Even if the core portion 2 is divided into two or more portions, the core portion 2 (the first core portion 2A and the second core portion 2B) and the seal portion 3 are firmly integrated by filling the opening portions 23a, 24a of the first joining groove 23 and the second joining groove 24 with the joining portion 31. In addition, even if the seal body 30 is formed at the center of the width direction of the core portion 2, it is possible to seal between the opposing surfaces 4a, 5a of the first member 4 and the second member 5. In this embodiment, the seal body 30 is deformed by contacting the opposing surfaces 4a, 5a of the first member 4 and the second member 5 with the two protrusions 30a, 30a, thereby sealing the space between the opposing surfaces 4a, 5a. Note that in this embodiment, the first core portion 2A and the second core portion 2B are separate bodies formed in an annular shape, but the first core portion 2A and the second core portion 2B may be an integral body connected by a plurality of connecting portions provided at appropriate positions with intervals in the circumferential direction.

Next, a gasket 1E according to another embodiment will be described with reference to FIG. 6. In the following description, the configuration and effects of parts common to the gasket 1 of the first embodiment shown in FIG. 1 and FIG. 2 will be omitted.

Figure 6(a) is a schematic plan view showing one of the joining recesses 22 of the core body portion 2 used in the gasket 1E. The wedge portion 25 in Figure 6(a) shows the upright state before the bending deformation process. The upper surface 20a on the inner circumferential surface 2a side of the core body main body portion 20 and the lower surface 20b (not shown) are formed with notched steps 21, 21. The upper surface 20a is formed with a joining recess 22 that is connected to the notched step 21 and extends to the outer circumferential side and is substantially circular in plan view. The joining recess 22 is provided with two first joining grooves 23, 23 and a second joining groove 24 adjacent to the first joining grooves 23, 23. The first joining grooves 23, 23 are arc-shaped in plan view according to the curvature of the joining recess 22 that is circular in plan view. The first joining groove 23 on the inner circumference side is located close to the notched step portion 21, and the first joining groove 23 on the outer circumference side is formed along the edge of the joining recess 22 and is located adjacent to the upper surface 20a of the core body main body portion 20. In addition, the wedge portions 25, 25 shown in FIG. 6(a) are in an upright state and are formed on the groove shoulder of the first joining grooves 23, 23 on the second joining groove 24 side, and have an arc shape when viewed in a plane along the first joining grooves 23, 23.

6(b) is a schematic plan view of a gasket 1E in which the core body 2 and the seal portion 3 are integrally formed through a bending deformation process and a molding process on the core body 2 of (a). The seal portion 3 is formed on the inner peripheral surface 2a side of the core body 2, and the seal body 30, the first joint grooves 23, 23, and the second joint groove 24 are filled on the inner peripheral side of the seal portion 3 to form a joint portion 31. Even though the wedge portions 25, 25 are arc-shaped in plan view, they are deformed by the bending deformation process so as to cover the opening portions 23a, 23a of the adjacent first joint grooves 23, 23. In addition, the seal portion 3 filled around the wedge portions 25, 25 suppresses the concentration of stress caused by the first member 4 and the second member 5 combined with the wedge portions 25, 25. Even with the first joining grooves 23, 23 and the wedge portions 25, 25 formed in such an arc shape, peeling of the seal portion 3 is suppressed, and the core portion 2 and the seal portion 3 are firmly integrated.

The configuration of the gaskets 1, 1A, 1B, 1C, 1D, and 1E is not limited to the configuration of each of the above-mentioned embodiments. For example, the core body 2 may be configured by joining a plurality of members divided along a width direction perpendicular to the circumferential direction of the core body 2. The number and positions of the joints 31 formed in the gaskets 1, 1A, 1B, 1C, 1D, and 1E are not limited to those shown in FIG. 1(a). The first joint groove 23, the second joint groove 24, and the wedge portion 25 formed at a plurality of locations on the core body 2 may be formed on different surfaces of the upper surface 20a and the lower surface 20b of the core body 2 for each formation location. The configurations and shapes of the first joint groove 23, the second joint groove 24, and the wedge portion 25 are not limited to those described above. For example, the configurations of the first joint groove 23, the second joint groove 24, and the wedge portion 25 may be different between the upper surface 20a and the lower surface 20b of the core body 2. In addition, in each of the above-mentioned embodiments, the first joining groove 23 has a rectangular opening portion 23a extending along the circumferential direction of the core body portion 2, and the wedge portion 25 extends along the circumferential direction of the core body portion 2, but this is not limited to this. For example, the first joining groove 23 may have an opening portion 23a extending along the width direction perpendicular to the circumferential direction of the core body portion 2, and the wedge portion 25 may extend along the width direction of the core body portion 2 so as to cover the opening portion 23a extending in the width direction of the core body portion 2. In addition, the second joining groove 24 is configured to be approximately flush with the notch step portion 21, but may be recessed from the notch step portion 21. In addition, the configuration of the seal portion 3 is not limited to the above-mentioned one, and for example, the seal main body portions 30, 30 may be formed on the inner peripheral surface 2a side and the outer peripheral surface 2b side of the core body portion 2, respectively.

1, 1A, 1B, 1C, 1D, 1E Gasket 2 Core body portion 20 Core body main body portion 23 First joining groove 23a Opening portion 24 Second joining groove 24a Opening portion 25 Wedge portion 25a One side 25b Other side 25c Base portion 25d Tip portion 3 Seal portion 30 Seal main body portion 31 Joint portion 4 First member 4a Opposing surface 5 Second member 5a Opposing surface 100 Molding die 130 Cavity r Molding material

Claims (6)

A gasket that is attached between two members, a first member and a second member, which are joined together,
The sealing member is made of an elastic material and is integrally formed with the annular core portion.
The core portion includes a core body portion sandwiched between the opposing surfaces of the two members, a first concave joining groove, a second concave joining groove formed adjacent to the first joining groove, and a convex wedge portion formed on a groove shoulder on the second joining groove side of the first joining groove and protruding toward an opening of the first joining groove,
A gasket characterized in that the sealing portion has a seal main body portion that seals between the opposing surfaces of the two components, and a joint portion formed by filling the elastic material up to the opening positions of the first joint groove and the second joint groove. In claim 1,
A gasket characterized in that the core portion has the first joining groove, the second joining groove and the wedge portion formed on each of both surfaces facing the opposing surfaces of the two members. In claim 1 or 2,
The core portion is made of a metal material or a thermoplastic resin material,
The gasket is characterized in that the wedge portion is bent so as to cover an opening portion of the first joint groove. A method for manufacturing a gasket having an annular core portion and a seal portion made of an elastic material that is insert-molded into the core portion, the gasket being attached between two members, a first member and a second member, which are joined together, comprising:
The core portion includes a core body main body portion sandwiched between the opposing surfaces of the two members, a first concave joining groove, a second concave joining groove formed adjacent to the first joining groove, and a protruding wedge portion formed on a groove shoulder of the first joining groove on the second joining groove side,
a bending deformation process of bending the wedge portion toward an opening portion of the first joining groove so as to cover the opening portion;
A method for manufacturing a gasket, comprising a molding process of filling a molding material into a cavity of a molding die on which the core portion is placed, forming the sealing portion, and filling the molding material up to the opening positions of the first and second joining grooves to integrally form the joining portions. In claim 4,
A method for manufacturing a gasket, characterized in that in the bending and deforming process, the wedge portion in an upright state is bent and deformed toward the opening side of the first joining groove by the pressure from the molding die when the molding die is closed. In claim 4 or claim 5,
A method for manufacturing a gasket, characterized in that the wedge portion is a plate whose longitudinal cross section is formed in a tapered shape from the base to the tip, and the inclination from the base to the tip of one side on the second joining groove side is greater than the inclination from the base to the tip of the other side on the first joining groove side.

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