JP2007309343A - Cylinder head gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cylinder head gaskets for suppressing the deformation of cylinder bores of an engine having three or more cylinders, and the deformation of cylinder heads. <P>SOLUTION: The cylinder head gaskets 1A-1D comprise one or more metal structural plates 10, 20 having three or more cylinder bore holes 2. One of the metal structural plates 10, 20 has at least one of a folded back portion 11 formed by folding back the periphery of each cylinder bore hole 2 and a bead 21. At least one of the folded back portion 11 and the bead 21 is formed wider near bolt holes and narrower between the bolt holes 4. On both longitudinal end sides of each of the cylinder head gaskets 1A-1D, it is formed wider even between the bolt holes 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cylinder head gasket having three or more cylinder bore holes for sandwiching and sealing between two members such as a cylinder head and a cylinder block of an engine, and more particularly, deformation of the cylinder bore. It is related with the cylinder head gasket which can suppress.

  The cylinder head gasket is sandwiched between the cylinder head of an automobile engine and a cylinder block (cylinder body) and is fastened by a head bolt to seal fluid such as combustion gas, oil, and cooling water. Yes.

  On the other hand, recently, the weight reduction of the engine has progressed, and the low rigidity of the engine has been further promoted. However, due to this low rigidity, the deformation is increasing at each part of the engine. Among them, the warp in the longitudinal direction of the cylinder head is a problem.

  This cylinder head warps because the bolt tightening area at both ends in the longitudinal direction of the engine is smaller than the other parts, but the bolt tightening force at both ends is greater than the other parts. Due to the fact that And this phenomenon has become more noticeable on low-rigidity cylinder heads that have been reduced in weight. In particular, in-line six-cylinder integrated heads have a large effect because the length of the cylinder head is long.

  When the cylinder head is warped in the longitudinal direction, a phenomenon occurs in which cylinder bore deformations at both ends (front side and rear side) of the engine become larger than those of other cylinders. This deformation of the cylinder causes inconveniences for the engine such as oil rise, increased frictional resistance in the cylinder and deterioration of fuel consumption. Therefore, warping of the cylinder head is an important problem to be solved.

  For example, when the cylinder block is an open deck type engine, as shown in FIG. 11, in the upper part of the cylinder, the cylinder bores (NO.1 and NO.4) at both ends in the longitudinal direction face the outside in three directions. Pulled and stretched triangular rice ball-shaped deformation occurs, and the cylinder bore (NO.2 and NO.3) arranged on the center side is pulled and extended in the width direction, that is, in the two directions facing the outside Deform the egg shape.

  Countermeasures against the warping of the cylinder head are taken according to the respective states in the engine structure and the gasket structure, and one of them is to increase the compression resistance at both ends of the cylinder head gasket from the other parts, thereby It is known that head warpage can be alleviated.

  On the other hand, regarding the increase / decrease in compression resistance, the second base material configuration is used to make the tightening load uniform and to suppress the bore deformation on the cylinder block side in the metal laminated gasket having a single cylinder hole (cylinder bore hole). A metal laminate in which a folded portion that forms a cylinder hole by folding the plate toward the first base metal component plate side is provided, and a folded width of the folded portion is narrower at a portion separated from the fastening bolt than a portion near the fastening bolt A shaped gasket has been proposed (see, for example, Patent Document 1).

However, since this cylinder head gasket relates to a gasket having a single cylinder bore hole, it does not address the problem of deformation in the longitudinal direction of the gasket having three or more cylinder bore holes. Cannot cope with head warpage.
Japanese Patent Laid-Open No. 11-36980

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a cylinder head gasket capable of suppressing deformation of a cylinder bore of an engine having three or more cylinders and deformation of the cylinder head. It is to provide.

  In order to achieve the above object, a cylinder head gasket according to the present invention is a cylinder head gasket composed of one or a plurality of metal component plates having three or more cylinder bore holes. In addition, at least one of a folded portion and a bead that is folded around each cylinder bore hole is provided, and at least one of the folded portion and the bead is formed so that the vicinity of the bolt holes is wide and the space between the bolt holes is narrow. On both ends in the longitudinal direction of the cylinder head gasket, a wide gap is formed even between the bolt holes.

  As this bead, a full bead is usually used, but a half bead may be used as long as it is a bead that seals around the cylinder bore hole. Also, a combination of several beads may be used. In the case of this combination, if at least one of the beads has the above-described configuration, it is included in the present invention. Further, even when both the folded portion and the bead are provided, at least one of the configurations may be used. Further, this bead or these beads may or may not be inside the folded portion. That is, the positional relationship between the folded portion and the bead is not limited. Furthermore, the folded portion and the bead are usually formed on different metal constituent plates, but may be formed on the same metal constituent plate.

  In the present invention, there are bolt arrangement, tightening force, cylinder structure, etc. that affect cylinder bore deformation, but not only in the vicinity of the bolt hole but also at the both ends in the longitudinal direction of the gasket where a large load is applied. A part or bead is formed widely, and the partial excessive load applied to the upper part of the cylinder is relaxed by receiving it in this wide region to suppress the deformation of the cylinder bore and the warp deformation of the cylinder head. It is.

  That is, at least one of the folded portion and the bead is formed widely in the vicinity of the bolt hole in which the fastening bolt is disposed and narrowed between the adjacent bolt holes, so that the surface pressure around each cylinder bore hole is increased. Equalize to prevent deformation of each cylinder bore. At the same time, at the outer part in the longitudinal direction of the gasket, which is a large deformation portion, at least one of the folded portion and the bead is formed wider to enhance the compression resistance than the other seal portions, and the load is more evenly distributed. Thereby, the warp deformation of the cylinder head is prevented. In addition, the magnitude | size of this folding | returning part or a bead can be calculated | required from the surface pressure distribution obtained from experiment or calculation.

  According to the cylinder head gasket of the present invention, at least one of the folded portion and the bead is formed so that the vicinity of the bolt holes is wide and the width between the bolt holes is narrow, and between the bolt holes at both ends in the longitudinal direction of the cylinder head gasket. Even if it is formed widely, the pressing force around the cylinder bore can be made more uniform, and the deformation of the cylinder bore of the engine can be suppressed, and the load applied to the cylinder head can be made uniform, and the engine cylinder head is warped and deformed. Can be suppressed.

  Next, an embodiment of a cylinder head gasket according to the present invention will be described with reference to the drawings. 1 to 10 are schematic explanatory diagrams, and the dimensions of the cylinder bore, the size of the folded portion, the size of the bead, etc. are actually shown so that the configuration can be more easily understood. Different from, exaggerated.

  A cylinder head gasket according to the present invention is a metal gasket sandwiched between an engine member of an engine cylinder head and a cylinder block (cylinder body), and includes a high-temperature and high-pressure combustion gas in a cylinder bore, a cooling water passage, Seals fluid such as cooling water and oil in the cooling oil passage.

  This cylinder head gasket is a cylinder head gasket for engines of 3 cylinders or more, and is a metal component plate (metal substrate) formed of mild steel plate, stainless annealed material (annealed material), stainless tempered material (spring steel plate), etc. It is configured to have one or more. Moreover, it manufactures according to the shape of engine members, such as a cylinder block.

  As shown in FIGS. 1 to 10, the cylinder head gaskets 1A to 1D include a cylinder bore hole (combustion chamber hole) 2, a liquid hole 3 for circulating cooling water and engine oil, and a fastening head bolt. Bolt holes 4 and the like are formed. Further, sealing means such as the folded portion 11 and the beads 21 are formed around the cylinder bore hole 2.

  A cylinder head gasket 1A according to the first embodiment shown in FIGS. 1 to 3 includes two metal component plates 10 and 20, and one metal component plate 10 and 20 includes a first metal component plate 10 and A folded portion 11 is provided by folding around the cylinder bore hole 2 of the second metal component plate 20. As shown in FIG. 2, a full bead 21 surrounding the cylinder bore 2 is provided in the second metal component plate 20 inside the folded portion 11. That is, the full bead 21 is disposed on the inner peripheral side from the end portion 11 a of the folded portion 11.

  In this cylinder head gasket 1A, the width Ba of the folded portion 11 shown in FIG. 2 is formed so that the vicinity of the bolt holes 4 is wide and the width between the bolt holes 4 is narrow. Widely formed even between the holes 4. In the first embodiment, the width Ba of the folded portion 11 is changed, but the width of the full bead 21 (the hatched portion in FIG. 3) Bb, that is, the first metal component plate 11 of the full bead 21 in FIG. The distance Bb of the missing part is not changed. The changing width ba of the turned-up portion 11 can be obtained with reference to the surface pressure distribution obtained from experiments and calculations with respect to the desired surface pressure distribution in the cylinder head gasket 1A.

  In the cylinder head gasket 1B of the second embodiment shown in FIGS. 4 and 5, the width of the full bead 21 (see FIG. 5) is adjusted in accordance with the change in the width Ba of the folded portion 11 of the cylinder head gasket 1A of the first embodiment. Bb is also formed in the vicinity of the bolt holes 4 so as to be narrow between the bolt holes 4, and at the both ends in the longitudinal direction of the cylinder head gasket 1B, even between the bolt holes 4. The changing width ba of the turned-up portion 11 and the changing width Bb of the full bead 21 can be obtained with reference to the surface pressure distribution obtained from experiments and calculations with respect to the desired surface pressure distribution in the cylinder head gasket 1B. it can.

  The cylinder head gasket 1C according to the third embodiment is composed of a plurality of metal component plates. In one first metal component plate 10 of the metal component plates, the cylinder bore hole 2 of the second metal component plate 20 is formed. A folded portion 11 is provided by folding around the periphery. Further, as shown in FIG. 6, on the outer peripheral side of the end portion 11 a of the folded portion 11, a full bead 21 is provided in the second metal constituting plate 20 so as to surround the cylinder bore hole 2. That is, the full bead 21 is arranged on the outer peripheral side from the end portion 11 a of the folded portion 11.

  In the cylinder head gasket 1C of the third embodiment shown in FIGS. 6 to 8, the width Ba of the folded portion 11 shown in FIG. 6 is constant, and the width (shaded portion in FIG. 8) Bb of the full bead 21 is set to the bolt hole. The vicinity of 4 is wide and the space between the bolt holes 4 is narrow, and at both ends in the longitudinal direction of the cylinder head gasket 1C, the space between the bolt holes 4 is also wide. In the third embodiment, the width Bb of the full bead 21 is changed without changing the width Ba of the folded portion 11. The changing width Bb of the full bead 21 can be obtained with reference to the surface pressure distribution obtained from experiments and calculations with respect to the desired surface pressure distribution in the cylinder head gasket 1C.

  In the cylinder head gasket 1D of the fourth embodiment shown in FIGS. 9 and 10, the width of the full bead 21 (shaded portion in FIG. 10) Bb and the width Ba of the folded portion 11 are wide in the vicinity of the bolt hole 4, and the bolt The width between the holes 4 is narrow, and the both ends of the cylinder head gasket 1D in the longitudinal direction are wide even between the bolt holes 4. However, in this case, the width Ba of the folded portion 11 changes, and the position of the end portion 11a of the folded portion 11 is different from that of the cylinder head gasket 1C of the third embodiment. The width Bb of 21 is also different from the cylinder head gasket 1C of the third embodiment. The changing width ba of the folded portion 11 and the changing width Bb of the full bead 21 can be obtained with reference to the surface pressure distribution obtained from experiments and calculations with respect to the desired surface pressure distribution in the cylinder head gasket 1D. it can.

  According to the cylinder head gaskets 1 </ b> A to 1 </ b> D having the above configuration, the wide folded portion 11 or the wide full bead 21 is disposed around each bolt hole 4 in which the fastening bolt that greatly affects the cylinder bore deformation is disposed. Since the large pressing force generated by fastening of the fastening bolt can be relieved by these, it is possible to prevent the pressing force from concentrating around the bolt hole 4. In addition, since the wide folded portion 11 or the wide full bead 21 is disposed on both ends in the longitudinal direction of the cylinder head gaskets 1A to 1D, a partial excessive load applied to the upper portion of the cylinder is applied to these wide folded portions 11 or The wide full bead 21 can be relaxed. Therefore, cylinder bore deformation and cylinder head warpage deformation can be suppressed.

  According to the configurations of the cylinder head gaskets 1A and 1D according to the first and fourth embodiments, both the width Ba of the folded portion and the width Bb of the full bead 21 are changed. The cylinder bore deformation countermeasure and the cylinder head warpage deformation countermeasure corresponding to the structure of the engine block can be performed more finely.

  In the above description, the full bead 21 has been described as a bead having an arc shape in cross section. However, the bead shape is not particularly limited in the present invention, and the cross shape may be an arc shape, a sine shape (cosine), a trapezoidal shape, or a triangular shape. (Yamagata) shape is also included.

It is a top view which shows the cylinder head gasket of 1st Embodiment. It is a fragmentary sectional view showing the cylinder head gasket of a 1st embodiment. It is a partial expanded plan view which shows the cylinder head gasket of 1st Embodiment. It is a top view which shows the cylinder head gasket of 2nd Embodiment. It is the elements on larger scale which show the cylinder head gasket of 2nd Embodiment. It is a fragmentary sectional view showing a cylinder head gasket of a 3rd embodiment. It is a top view which shows the cylinder head gasket of 3rd Embodiment. It is a partial enlarged plan view which shows the cylinder head gasket of 3rd Embodiment. It is a top view which shows the cylinder head gasket of 4th Embodiment. It is a partial enlarged plan view which shows the cylinder head gasket of 4th Embodiment. It is a figure which shows an example of the measurement result of a deformation | transformation of a cylinder bore.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A-1D Cylinder head gasket 2 Cylinder bore hole 3 Liquid hole 4 Bolt hole 10 1st metal component board 11 Folding part 11a End part of a folding part 20 2nd metal component board 21 Bead Ba Width of folding part Bb Width of bead

Claims (1)

  A cylinder head gasket composed of one or a plurality of metal component plates having three or more cylinder bore holes, wherein one of the metal component plates has a folded portion and a bead that are folded around each cylinder bore hole. At least one of the folded portion and the bead is formed so that the vicinity of the bolt holes is wide and the width between the bolt holes is narrow, and at both ends in the longitudinal direction of the cylinder head gasket, between the bolt holes, Cylinder head gasket is characterized by being widely formed.

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