JP6044782B2 - Head gasket - Google Patents

Description

  The present invention relates to a head gasket, and more specifically, in an internal combustion engine in which a chain case is joined via a cylinder block joined to each other and a FIPG applied to an end face of the cylinder head, a plurality of gasket members are superposed. Thus, the present invention relates to a head gasket interposed between the cylinder block and the cylinder head.

  An internal combustion engine generally includes a cylinder block and a cylinder head, and the cylinder head is supplied with lubricating oil for lubricating the valve operating mechanism. For this reason, in order to seal the lubricant so that it does not leak or ooze out from the joint between the cylinder block and the cylinder head, it is generally performed with a head gasket sandwiched between the cylinder block and the cylinder head. .

  In such an internal combustion engine, there is a further one in which a chain for driving the valve mechanism is disposed on one end face of the cylinder block and the cylinder head. In this case, as schematically shown in FIG. 3, a gasket having fluidity such as liquid is applied to the end surfaces of the assembled cylinder block 1 and cylinder head 2 in accordance with the shape of the chain case. A chain case 3 for covering the chain is joined through an applied FIPG (Formed In Place Gasket) 5. In the present application, the applied liquid gasket itself is referred to as FIPG3. The end surfaces of the cylinder block 1 and the cylinder head 2 and the joint portion of the chain case 3 constitute a so-called three-surface mating portion.

  By the way, as a head gasket 4 ′ interposed between the cylinder block 1 and the cylinder head 2, a plurality of metal gasket members 40 ′ are used in order to ensure a surface pressure between the cylinder block 1 and the cylinder head 2. , 40 'is polymerized. In such a head gasket 4 ′, for example, as shown in FIG. 4, the gasket members 40 ′ and 40 ′ made of thin plates are individually molded in substantially the same shape, and the superposed gasket members 40 ′ and 40 ′ are mutually connected. In order to prevent displacement, generally, for example, a caulking portion 45 ′ is formed at a position indicated by a one-dot chain line in FIG. 4, and the gasket members 40 ′ and 40 ′ are joined to each other.

  Moreover, in the head gasket formed by superposing a plurality of gasket members, as disclosed in Patent Document 1, a planar shape in which at least two metal gasket members are connected in a line-symmetric relationship from a thin metal material. It is known that the metal gasket members are formed, the connected metal gasket members are bent around the connecting portion, and the metal gasket members are stacked on each other.

  In the gasket disclosed in Patent Document 1, connecting portions are partially formed on the longitudinal sides of each metal gasket member (in FIG. 1 and FIG. 2 of Patent Document 1, two locations), and the metal gasket members are connected to each other. Has been.

JP-A-6-207673

  However, in the case where the chain case is joined as described above, the three-surface mating portion of the head gasket 4 ′ is located at the edge located on the end face side of the cylinder block 1 and the cylinder head 2, that is, between both It is located on the side in the short direction (width direction) of the sandwiched head gasket 4 '. On the other hand, among the above conventional techniques, as shown in FIG. 3, a plurality of gasket members 40 'and 40' which are simply molded individually are superposed and joined together by caulking portions 45 '. In FIG. 5, as shown in FIG. 5, there is a case where the gap G is generated at the end edges of the gasket members 40 ′ and 40 ′ by forming the caulking portion 45 ′. In this case, when a gap G occurs particularly at the edge located on the side where the three surfaces are aligned, as shown in FIG. 6, a gap S is generated between the FIPG 5 to be applied later. And there existed problems, such as the path | route from which the lubricating oil supplied to the cylinder head 2 oozes out outside by this clearance gap S.

  Further, among the above conventional techniques, even in Patent Document 1, the connecting portion of each metal gasket member is formed on the side in the longitudinal direction that is not located on the end face side that joins the chain case. The edges of the metal gasket members may deviate from each other, causing a gap with the FIPG to be applied in the same manner as shown in FIG. 6, and as a result, the lubricating oil oozes out to the outside. was there.

  The present invention has been made in order to solve the above-mentioned problems, and even if a plurality of gasket members are superposed with a simple configuration, the cylinder block and the end located on the end face side of the cylinder head are joined together. To provide a head gasket for constructing a seal structure that can be sealed without causing a gap between the edges and generating a gap with the FIPG, and thus preventing lubricant from seeping out. With the goal.

  In order to achieve the above object, the head gasket of the present invention superimposes a plurality of gasket members in an internal combustion engine in which a chain case is joined via a cylinder block joined to each other and a FIPG applied to the end face of the cylinder head. The head gasket is interposed between the cylinder block and the cylinder head, and the edges to be arranged on the end face side of each gasket member are connected to each other by a connecting portion, Formed symmetrically with respect to each other across the fold line of the connecting portion, the plurality of gasket members are superposed by being bent at the fold line of the connecting portion, and the connecting portion is disposed on the end face side. It is interposed between a cylinder block and the cylinder head.

  In the head gasket of the present invention, the cylinder block to which the chain case is joined and the end edges of the gasket members to be arranged on the end face side of the cylinder head are connected to each other by a connecting portion. And each gasket member is shape | molded mutually symmetrically on both sides of the bending line of a connection part. Prior to joining the cylinder block and the cylinder head, the plurality of gasket members are polymerized by bending the head gasket formed in this way at the fold line of the connecting portion. At this time, the cylinder block to which the chain case is joined and the edge of each gasket member to be disposed on the end face side of the cylinder head are connected by the connecting portion, and therefore are overlapped to be aligned with each other. There is no deviation. Therefore, it is not necessary to form a caulking portion as in the prior art. The head gasket in which the gasket members are overlapped in this way is sandwiched between the cylinder block and the cylinder head in a state in which the connecting portion is disposed on the end face side (= three face mating portion side). The edges of the gasket members on the end face side where the FIPG is applied are connected to each other by a connecting portion, and the edges do not deviate from each other. Therefore, there is no gap between them, and therefore a head gasket that can constitute a seal structure that can reliably prevent the lubricating oil supplied into the cylinder head from oozing out is provided. can do.

It is the top view which showed one Embodiment of the head gasket of this invention in the unfolded state before bending. The head gasket of the present invention is sandwiched and assembled between a cylinder block and a cylinder head, and a partially enlarged cross-sectional view shown for explaining a state in which a chain case is assembled by applying FIPG to the end faces of the cylinder block and the cylinder head It is. 1 is a front view schematically showing an internal combustion engine to which the present invention is applied. It is the top view shown in order to demonstrate the conventional common head gasket which shape | molded each gasket member separately and superposed | polymerized and formed the crimp part. Partial enlargement shown exaggerated to explain a conventional head gasket in a state in which each gasket member is overlapped to form a caulking portion, thereby causing misalignment between the edges on the three-surface mating portion side. It is sectional drawing. As shown in FIG. 5, the head gasket according to the prior art in which the edge has shifted is sandwiched between the cylinder block and the cylinder head and assembled, so that the cylinder block and the FIPG applied to the end face of the cylinder head are assembled. FIG. 6 is a partial enlarged cross-sectional view shown to explain that a gap that causes the lubricant to ooze out occurs.

One embodiment of the head gasket of the present invention will be described mainly based on FIGS. 1 and 2.
An internal combustion engine to which the head gasket of the present invention is applied is formed by joining a chain case 3 to end faces of a cylinder block 1 and a cylinder head 2. A three-surface mating portion is formed between the end case and the chain case 3 joined to the end surface. A head gasket 4 is interposed between the cylinder block 1 and the cylinder head 2, and FIPG 5 is applied to the end faces of the cylinder block 1 and the cylinder head 2 to join the chain case 3. The head gasket 4 and the FIPG 5 constitute a seal structure of the internal combustion engine.

  The head gasket 4 of the present invention is composed of a thin metal plate that can be elastically deformed, and a plurality of gasket members 40, 40 and a connecting portion 41 that connects the gasket members 40, 40 adjacent to each other are continuous. So as to be integrally molded. Each gasket member 40, 40 is formed to have a shape corresponding to the joint surface between the cylinder block 1 and the cylinder head 2 when they are interposed between the cylinder block 1 and the cylinder head 2. This shape will be described in detail later. At least the edge of each gasket member 40, 40 to be disposed on the end surface side where the chain case 3 of the cylinder block 1 and the cylinder head 2 is joined (this end edge is “each end surface side”). The connecting portion 41 is provided on the side of the gasket member 40 in the short direction or the width direction. That is, for example, when the gasket members 40 and 40 are configured in two layers, the edge disposed on the end face side of the cylinder block 1 and the cylinder head 2 to which the chain case 3 of the two gasket members 40 and 40 is joined. Are connected to each other by the connecting portion 41. Therefore, in this case, as will be described later, when the gasket members 40 and 40 are overlapped with each other by being bent along the bending line l of the connecting portion 41 and sandwiched between the cylinder block 1 and the cylinder head 2, the connection is established. The part 41 is disposed only on the end face side of the cylinder block 1 and the cylinder head 2. On the other hand, for example, when the gasket member 40 is composed of three or more layers of gasket members 40, 40, 40..., The chain case 3 is used as a gasket member other than the gasket member 40 located at both ends of the series of gasket members 40. The cylinder block 1 to be joined and the edge arranged on the end face side of the cylinder head 2 and the edge opposite to this edge are connected to the adjacent gasket member 40 by connecting parts 41, 41, respectively. The gasket members 40 located at both ends of the gasket member 40 include an end edge disposed on the end face side of the cylinder block 1 and the cylinder head 2 to which the chain case 3 is joined, and an end edge facing the end edge. One of them is connected to the adjacent gasket member 40 by the connecting portion 41. Therefore, in this case, when the gasket members 40 and 40 are overlapped with each other and are sandwiched between the cylinder block 1 and the cylinder head 2 by bending along the bending line L of the connecting portion 41 as will be described later, The connecting portions 41 and 41 are disposed on both the end face side of the block 1 and the cylinder head 2 and the opposite side.

  In the case of the embodiment shown in FIG. 1, the connecting portion 41 is formed so as to be separated at two locations on both ends of the side in the short direction of the edge of the gasket member 40. A bending line L is set at the center of the connecting portion 41 as shown by a chain line in FIG. The fold line L is set so that the edges of the gasket members 40, 40 located on the three-surface mating portion side are aligned with each other when the connecting portion 41 is bent to superimpose the gasket members 40, 40. The head gasket 4 of the present invention is overlapped so that the edges located on the three-surface mating portion side of the gasket members 40 and 40 connected by the connecting portion 41 are aligned by being bent at the bending line L of the connecting portion 41. Therefore, the edges do not shift from each other. The connecting portion 41 of the present invention is not limited as long as the edges arranged on the three-surface mating portion side of the gasket member are aligned without being displaced by being bent along the folding line L, and separated in the short direction of the gasket member. It is not limited to forming in two places.

  The gasket members 40 are overlapped with each other by being bent at a bending line L of the connecting portion 41, and are formed to have a matching shape. Therefore, in the unfolded state before being folded in FIG. 1, the gasket members 40, 40 are formed in a shape that is line-symmetric with respect to the folding line L. Thus, in order to make the shape which made the some gasket member 40 and the connection part 41 continuous integrally, it can shape | mold easily in a short time by stamping out the metal thin plate which comprises the head gasket 4. FIG.

  The head gasket 4 molded as described above is bent at the fold line L of the connecting portion 41, so that the plurality of gasket members 40, 40 are superposed so as to be aligned with each other. Then, if necessary, FIPG 5 is applied to the upper surface of the cylinder block 1, and the head gasket 4 in which the gasket members 40, 40 are superposed is folded and the connecting portion 41 is positioned on the three-surface mating portion side. Further, the cylinder head 2 is placed thereon and fastened with a bolt or the like. Further, FIPG 5 is applied to the end faces of the cylinder block 1 and the cylinder head 2, and the chain case 3 is fastened and joined with a bolt or the like. The FIPG 5 applied to the end faces of the cylinder block 1 and the cylinder head 2 also enters between the cylinder block 1 and the cylinder head 2. At this time, as described above, the head gasket 4 of the present invention is superposed so that the edges located on the three-surface mating portion side of the gasket members 40 and 40 connected by the connecting portion 41 are aligned with each other. The FIPG 5 that has entered between the cylinder block 1 and the cylinder head 2 comes into close contact with the end edge of the head gasket 4 without forming a gap S (see FIG. 6 showing the prior art). Further, it is possible to reliably prevent the lubricating oil supplied to the cylinder head 2 from oozing out when the internal combustion engine is operated.

  The head gasket 4 of the present invention is not limited to the embodiment shown in the drawings, and as described above, the three or more gasket members 40, 40, 40. It can also be connected by. In this case, the connecting portion 41 is disposed not only on the end face side of the cylinder block 1 and the cylinder head 2 but also on the opposite side.

  1: Cylinder block, 2: Cylinder head, 3: Chain case, 4: Head gasket, 5: FIPG, 40: Gasket member, 41: Connecting part, L: Bending line

Claims (1)

In an internal combustion engine in which a chain case is joined via a cylinder block joined to each other and a FIPG applied to the end face of the cylinder head, a plurality of gasket members are superposed to form a space between the cylinder block and the cylinder head. A head gasket interposed between
Edges to be disposed on the end face side of each gasket member are connected to each other by a connecting portion, and are formed symmetrically with respect to each other with a bending line of the connecting portion interposed therebetween. A head gasket characterized in that the plurality of gasket members are superposed by being bent, and the connecting portion is interposed between the cylinder block and the cylinder head in a state where the connecting portion is disposed on the end face side.

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