JP2008025409A - Cylinder head gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder head gasket capable of certainly preventing oozing-out of oil from between gasket base plates deposited on a cylinder head bolt. <P>SOLUTION: The cylinder head gasket 3 is integrally formed by vertically superposing an upper gasket base plate 32 and a lower gasket base plate 33. Further, a peripheral edge of a bolt insertion hole 36a opened to the upper gasket base plate 32 is formed to a cylindrical shape by downwardly folding it so as to surround a peripheral edge end of a bolt insertion hole 36b of the lower gasket base plate 33 from above to below. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cylinder head gasket interposed between a cylinder head and a cylinder block, and particularly relates to a measure for preventing oil from adhering to a bolt inserted into a bolt insertion hole from being spread between gasket substrates. .

Conventionally, as shown in the following technical document 1, a cylinder head gasket is integrally formed by vertically stacking at least two gasket substrates, and a plurality of combustion is formed on gasket substrates adjacent to the top and bottom of the laminate. The chamber holes are formed in a line, and a plurality of bolt insertion holes are formed around the plurality of combustion chamber holes. Then, with the cylinder head gasket interposed between the cylinder head and the cylinder block, the cylinder head and the cylinder are tightened from the cylinder head side by the bolt inserted into the cylinder block through the bolt insertion hole of the cylinder head gasket. It can be assembled in a state where the space between the opposing surfaces of the block is sealed.
Japanese Patent Laid-Open No. 11-264472

  By the way, the male head of the cylinder head bolt that is inserted into the cylinder block from the cylinder head through the bolt insertion holes of the upper and lower gasket substrates eliminates friction with the female thread of the cylinder block and provides accurate torque. Oil is applied so that tightening is performed.

  In that case, since the bolt insertion holes respectively drilled in the upper and lower adjacent gasket substrates are formed to have the same diameter, the cylinder head bolt with the oil applied to the male screw portion is connected to each bolt insertion hole of the upper and lower gasket substrates. When tightening by inserting into the bolt, the male screw part of the cylinder head bolt comes into contact between the peripheral edges of the bolt insertion holes of the upper and lower gasket substrates, and the oil passes between the peripheral edges of the bolt insertion holes by the contact. If it entered between the upper and lower gasket substrates, there was a risk that oil would ooze out between the gasket substrates after assembly after the bolts had been tightened.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a cylinder head gasket that can reliably prevent the oil adhering to the cylinder head bolt from oozing out between the gasket substrates. There is to do.

  In order to achieve the above object, the present invention presupposes a cylinder head gasket that is interposed between a cylinder head and a cylinder block and seals between the opposing surfaces of the cylinder head and the cylinder block. The above gasket substrates are stacked one above the other to be integrally formed, and a plurality of combustion chamber holes are formed in a row in the gasket substrate adjacent to the top and bottom of the stacked body, and a plurality of holes are formed around the plurality of combustion chamber holes. Bolt insertion holes are drilled. And, the bolt insertion hole peripheral edge of the upper gasket substrate located on the upper side is formed in a cylindrical shape so as to surround the bolt insertion hole peripheral edge of the lower gasket substrate located on the lower side from above to below. Yes.

  With this specific matter, the bolt insertion hole peripheral edge of the lower gasket substrate located on the lower side is surrounded from above by the bolt insertion hole peripheral edge formed in the cylindrical shape of the upper gasket substrate located on the upper side. Therefore, when the cylinder head bolt with the oil applied to the male screw portion is inserted into the bolt insertion holes of the upper and lower gasket substrates, the male screw portion of the cylinder head bolt is located between the peripheral edges of the bolt insertion holes of the upper and lower gasket substrates. There is no contact between them, and the inner side of the periphery of the bolt insertion hole of the upper gasket substrate is contacted and inserted. For this reason, even if the cylinder head bolt is tightened, oil is prevented from entering between the upper and lower gasket substrates through the peripheral edges of the bolt insertion holes of the upper and lower gasket substrates. It is possible to reliably prevent oil from seeping out between the upper and lower gasket substrates after the finished assembly.

  In short, oil is applied to the male screw portion by forming the peripheral edge of the bolt insertion hole of the upper gasket substrate into a cylindrical shape so as to surround the peripheral edge of the bolt insertion hole of the lower gasket substrate from above to below. After the cylinder head bolts are assembled, the cylinder head bolts are inserted into the bolt insertion holes of the upper and lower gasket boards and tightened by tightening the bolts through the holes between the peripheral edges of the bolt insertion holes. It is possible to reliably prevent oil from seeping out between the upper and lower gasket substrates.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the cylinder head gasket according to the present invention is applied to a V-type 8-cylinder engine (V-type internal combustion engine) for automobiles will be described.

-Description of overall engine configuration-
Before describing the structure of the cylinder head gasket, the overall configuration of the engine in which the cylinder head gasket is used will be described.

  FIG. 1 is a diagram showing a schematic configuration inside the engine when the V-type engine 1 according to the present embodiment is viewed from the axial direction of the crankshaft 14. As shown in FIG. 1, the V-type engine 1 has a pair of left and right banks 10 </ b> L and 10 </ b> R protruding in a V-shape at the top of a cylinder block 11. Each of the banks 10L and 10R includes cylinder heads 12L and 12R installed at the upper end of the cylinder block 11. In the cylinder block 11, a plurality of cylinders 13L, 13R,... (For example, four in each bank 10L, 10R) are arranged with a predetermined sandwich angle (for example, 90 °). Pistons are accommodated in these cylinders 13L, 13R,... So as to be able to reciprocate, and each piston is connected to the crankshaft 14 via a connecting rod so that power can be transmitted. Further, a crankcase 15 is attached to the lower side of the cylinder block 11, and a space extending from a lower portion in the cylinder block 11 to the inside of the crankcase 15 is a crank chamber 16. An oil pan 17 is provided further below the crankcase 15. In this case, the crankshaft 14 is provided so as to extend in the longitudinal direction of the vehicle body, and the V-type engine 1 is mounted vertically in the front portion of the vehicle body.

  Further, the cylinder heads 12L and 12R of the V-type engine 1 have a divided structure. Specifically, the cylinder heads 12L and 12R are configured by cylinder head bodies 121L and 121R attached to the upper surface of the cylinder block 11 and camshaft housings 122L and 122R assembled on the upper side of the cylinder head bodies 121L and 121R. In addition, intake ports 123L, 123R,... Are provided inside the cylinder heads 12L, 12R of the V-type engine E, and exhaust ports 124L, 124R,.

-Cooling device-
Next, a cooling device that supplies cooling water to the left and right banks 10L and 10R and the cylinder heads 12L and 12R of the cylinder block 11 will be described with reference to FIGS. FIG. 2 is a plan view of the cylinder block 11 of the V-type engine 1 according to this embodiment as viewed from above. Here, in FIG. 2, odd-numbered cylinder rows are arranged in the left bank 10L (lower bank in FIG. 2), and even-numbered cylinder rows are arranged in the right bank 10R (upper bank in FIG. 2). In the cylinder row of the left bank 10L, the cylinder located at the front end (left end in FIG. 2) in the cylinder row direction is the first cylinder # 1, and the cylinder located on the rear side (right side in FIG. 2) is the third cylinder. # 3, and the cylinder located on the rear side (right side in FIG. 2) is the fifth cylinder # 5, and the cylinder located on the rear end (right end in FIG. 2) is the seventh cylinder # 7. In the cylinder row of the right bank 10R, the cylinder located at the front end in the cylinder row direction (left end in FIG. 2) is the second cylinder # 2, and the cylinder located on the rear side (right side in FIG. 2) is the fourth cylinder. Cylinder # 4, and the rear side (right side in FIG. 2) The cylinder located in the sixth cylinder # 6, and will be described cylinder located at the rear end (in FIG. 2 the right end) as an eighth cylinder # 8. The form of the cylinder number is not limited to this.

  The cylinder block 11 is configured as an open deck type. That is, the water jackets 21 and 21 are opened on the top surfaces (the cylinder heads 12L and 12R side) of the left and right banks 10L and 10R of the cylinder block 11, and the water jackets 21 and 21 are connected to the left and right banks 10L and 10R. Are formed between the outer walls 101L, 101R of the banks 10L, 10R of the cylinder block 11 and the cylinder walls 102L, 102R,... So as to surround substantially the entire circumference of the cylinders 13L, 13R,.

  A water pump that is driven by a rotational force from the crankshaft 14 is provided at a front position between the left and right banks 10 </ b> L and 10 </ b> R of the cylinder block 11. Further, between the left and right banks 10L, 10R of the cylinder block 11, a cooling water passage 22 extending in the cylinder row direction (left-right direction in FIG. 2) is provided. The cooling water passage 22 is integrally partitioned from the circumferential direction by inner walls 103L and 103R of the banks 10L and 10R of the cylinder block 11 and front and rear shielding ribs 104a and 104b that shield both front and rear ends of the inner walls 103L and 103R. Then, it is covered with a lid 105 (shown in FIG. 1) from above and kept in a sealed state. The cooling water passage 22 is provided between the left and right banks 10L and 10R from the rear side to the rear end of the cylinder block 11 because the water pump is provided at the front side position between the left and right banks 10L and 10R. positioned.

  The cooling water passage 22 is provided with a communication port 221 that communicates with the discharge port of the water pump at a front position in the cylinder row direction. The communication port 221 opens at the front end of the lid 105. The cooling water discharged from the discharge port of the water pump is supplied from the communication port 221 to the front end of the cooling water passage 22.

  Further, the cylinders on the rear side in the cylinder row of the left bank 10L of the cooling water passage 22, for example, the inner walls 103L and 103R corresponding to the third to eighth cylinders # 3 to # 8, respectively, have six corresponding positions. Introducing ports 222, 222,... For introducing cooling water into the water jackets 21, 21 of the left and right banks 10L, 10R of the block 11 are opened. The cooling water introduced from the respective inlets 222 is supplied to the cooling water passage 22 side of the water jackets 21 and 21 of the left and right banks 10L and 10R (in FIG. 2, the upper side of the water jacket 21 of the left bank 10L and the right bank 10R). The water jacket 21 of the left and right banks 10L, 10R is introduced from the cooling water passage 22 side of the water jackets 21, 21 of the left and right banks 10L, 10R (the water jacket 21 of the left bank 10L in FIG. 2). Circulate around the front side in the cylinder row direction to the lower side and the upper side of the water jacket 21 of the right bank 10R, and circulate around the rear side in the cylinder row direction toward the anti-cooling water passage 22 side. . In this case, since the water pump is provided at the front side position between the left and right banks 10L and 10R, the front end of the cooling water passage 22 is the front cylinder in the cylinder row direction of the left bank 10L (for example, the first cylinder # 1) and This substantially corresponds to the cylinder (for example, the second cylinder # 2) on the front side in the cylinder row of the right bank 10R, and in this respect, the first cylinder # 1 on the front end in the cylinder row direction on the left bank 10L of the cooling water passage 22 and The inlet port cannot be opened at the corresponding position of the inner walls 103L and 103R corresponding to the second cylinder # 2 at the foremost end in the cylinder row direction of the right bank 10R.

  Further, at the rear end of the cooling water passage 22 in the cylinder row direction, a cooling water supply port 23a for supplying cooling water to the left and right cylinder heads 12L and 12R from the rear end of the cooling water passage 22 in the cylinder row direction, respectively. , 23b is established. As shown in FIG. 1, the cooling water supplied from the cooling water supply ports 23a and 23b is supplied from rear end portions of water jackets 125 and 125 extending in the cylinder row direction in the left and right cylinder heads 12L and 12R, respectively. The cooling water circulated in the water jackets 125 and 125 is led out outward (front of the vehicle body) from the front end portions of the cylinder heads 12L and 12R.

−Cylinder head gasket−
Next, FIG. 3 to FIG. 5 are used for the cylinder head gasket 3 that seals between the facing surfaces of the left and right banks 10L, 10R of the cylinder block 11 and the cylinder head bodies 121L, 121R of the left and right cylinder heads 12L, 12R. I will explain. 3 is a plan view of the cylinder head gasket as viewed from above, and FIGS. 4 and 5 are cross-sectional views of the cylinder head gasket cut in the vicinity of the bolt insertion holes.

  As shown in FIG. 3, between the upper surfaces of the left and right banks 10L, 10R of the cylinder block 11 and the lower surfaces of the cylinder head bodies 121L, 121R of the left and right cylinder heads 12L, 12R, 11 is shown only between the upper surface of the right bank 10R and the lower surface of the cylinder head body 121R of the right cylinder head 12R). The cylinder head gasket 3 is integrally formed by vertically stacking an upper gasket substrate 32 and a lower gasket substrate 33. Further, each cylinder # of the cylinder head gasket 3 in which the anti-cooling water passage 22 side of the water jackets 21 and 21 of the left and right banks 10L and 10R and the water jackets 125 and 125 of the left and right cylinder heads 12L and 12R face each other. 1 to # 8, the first to the first through which the cooling water from the water jackets 21 and 21 of the left and right banks 10L and 10R of the cylinder block 11 is led to the water jackets 125 and 125 of the left and right cylinder heads 12L and 12R. The fourth outlets 31a, 31b, 31c, 31d are opened sequentially from the front side in the cylinder row direction (left side in FIG. 3). In the cylinder head gasket 3, four combustion chamber holes 35, 35,... That are drilled in accordance with the cylinders 13 R, 13 R,. Further, around each combustion chamber hole 35, as shown in FIG. 4, a cylinder head bolt B for fastening the right bank 10R and the right cylinder head 12R of the cylinder block 11 (only one is shown in FIG. 4). Are inserted through a plurality of bolt insertion holes 36, 36,. In this case, each bolt insertion hole 36 formed in the cylinder head gasket 3 includes a bolt insertion hole 36a opened in the upper gasket substrate 32 and a bolt opened in the lower gasket substrate 33, as shown in FIG. It is comprised by the insertion hole 36b. 3, 37, 37,... Are oil return holes for returning the oil drilled in the cylinder head gasket 3, and 38 is a water hole through which cooling water flows.

  The peripheral edge of the bolt insertion hole 36a that opens in the upper gasket substrate 32 is bent downward so as to surround the peripheral edge of the bolt insertion hole 36b of the lower gasket substrate 33 from above to below. Is formed.

  Therefore, in the above embodiment, each bolt insertion hole 36 of the cylinder head gasket 3 is formed at the peripheral edge of the bolt insertion hole 36b of the lower gasket substrate 33 by the periphery of the bolt insertion hole 36a formed in the cylindrical shape of the upper gasket substrate 32. Since the cylinder head bolt B in which oil is applied to the male threaded portion Ba is inserted into the bolt insertion holes 36a and 36b of the upper and lower gasket substrates 32 and 33, the cylinder head is The male threaded portion Ba of the bolt B does not contact the peripheral edge of the bolt insertion hole 36b of the lower gasket substrate 33, and is inserted through the inner periphery of the bolt insertion hole 36a of the upper gasket substrate 32. . For this reason, even if the cylinder head bolt B is tightened, the oil is prevented from entering between the upper and lower gasket substrates 32 and 33 through the gap between the peripheral edges of the bolt insertion holes 36a and 36b. It is possible to reliably prevent oil from seeping out from between the upper gasket substrate 32 and the lower gasket substrate 33 after the assembly after the tightening of the bolt B is completed.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above embodiment, the cylinder head gasket of the V-type 8-cylinder engine 1 has been described. However, the present invention can be applied as a cylinder head gasket of any engine such as an in-line engine or a horizontally opposed engine in addition to the V-type engine.

  Further, in the above embodiment, the cylinder head gasket 3 in which the upper gasket substrate 32 and the lower gasket substrate 33 are stacked vertically and integrally formed is used, but a cylinder formed by stacking three or more gasket substrates vertically. A head gasket may be used. In this case, the peripheral edge of the bolt insertion hole of the upper gasket substrate located in the uppermost layer is positioned above the peripheral edge of the bolt insertion hole of each lower gasket substrate below it. It is bent downward so as to surround from below to form a cylindrical shape.

It is a figure which shows schematic structure inside the engine which looked at the V-type engine using the cooling device concerning embodiment of this invention from the axial center direction of the crankshaft. It is the top view which looked at the cylinder block of the V type engine from the upper part. It is a top view of a cylinder head gasket. It is sectional drawing which cut | disconnected the cylinder head gasket in the bolt insertion hole vicinity. It is sectional drawing of the bolt insertion hole vicinity in the state which inserted the cylinder head bolt.

Explanation of symbols

1 V-type engine (V-type internal combustion engine)
11 Cylinder blocks 12L, 12R
Cylinder head 3 Cylinder head gasket (laminate)
32 Upper gasket substrate 33 Lower gasket substrate 35 Combustion chamber hole 36 Bolt insertion hole 36a of cylinder head gasket Bolt insertion hole 36b of upper gasket substrate Bolt insertion hole of lower gasket substrate

Claims (1)

In a cylinder head gasket that is interposed between a cylinder head and a cylinder block and seals between the opposing surfaces of the cylinder head and the cylinder block,
At least two or more gasket substrates are stacked one above the other, and are integrally formed. A plurality of combustion chamber holes are formed in a row in the gasket substrate adjacent to the top and bottom of the stacked body. A plurality of bolt insertion holes are drilled around the chamber hole,
The peripheral edge of the bolt insertion hole of the upper gasket substrate located on the upper side is formed in a cylindrical shape so as to surround the peripheral edge of the bolt insertion hole of the lower gasket substrate located on the lower side from above to below. Cylinder head gasket characterized by

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