JP3575511B2 - Seal structure of internal combustion engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
2. Description of the Related Art Some engines mounted on automobiles include a valve drive device and are connected by a timing chain. Since the chain cover that protects and stores the device is mounted over the cylinder head and the cylinder block, the precision of the mounting surface and the application of the sealant are accurately performed.
The present invention relates to a seal structure of an internal combustion engine at a place where the chain cover is attached or the like.
[0002]
[Prior art]
Conventionally, when attaching a chain cover to an engine body composed of a cylinder head and a cylinder block, as shown in FIG. 7, the periphery of the chain cover 1 and the mounting surfaces of the end portions of the cylinder block 2 and the cylinder head 3 are bolted. Are combined. The cylinder block 2 and the cylinder head 3 are connected to each other by a bolt (not shown) with a head gasket 5 (see FIG. 6) interposed on a joint surface s overlapping each other. The chain cover 1 is configured such that a peripheral mating surface 6 shown in FIGS.
[0003]
Further, as shown in FIG. 9, a sealing groove 8 is formed in addition to the bolt hole 7 on the peripheral mating surface 6 of the chain cover 1, and the sealing groove 8 has a constant groove width W and a constant depth D and has an entire circumference. Are provided intermittently. When the sealing agent m is filled into the sealing groove 8 so as to be raised, and the mating surface 6 is joined to the mounting surface of the engine body, the sealing agent m is crushed, and the sealing agent m flows into a gap due to a slight dimensional error. To improve hermeticity. The sealing in this way prevents the oil in the cover from leaking to the outside. Further, Japanese Utility Model Laid-Open No. 4-110347 discloses a structure in which an oil pump body is disposed so that an upper end thereof is aligned with a cylinder block, and an upper end abuts on a head gasket. When the oil pump body thermally expands, the head gasket is lifted. The state is maintained and the sealing property is maintained.
[0004]
[Problems to be solved by the invention]
By the way, as shown in FIG. 6, each end face of the cylinder block 2 and the cylinder head 3 has a step portion p at the joint surface portion t at the time of mounting due to a variation in manufacturing tolerance. The sealing agent m flows into this portion and fills the gap, so that the sealing property is maintained.
However, the pitch a between the head gaskets of the tightening bolts 4a for fixing the cylinder head 3 is shorter than the pitch b between the head gaskets of the tightening bolts 4b for fixing the cylinder block 2, and the tightening force varies greatly. In some cases, the surface pressure of the mating surface 6 of the chain cover 1 may not be substantially uniform. For this reason, when the sealant m may be affected by the vibration during the operation of the engine, it is necessary to check the sealability many times.
[0005]
In addition, it is conceivable that the complicated inspection work is reduced, the position of the tightening bolt 4b of the cylinder block 2 is adjusted to the cylinder head 3, and the tightening bolt 4a is disposed at a target position around the joint surface t. In addition, since the design of the chain cover 1 on the mating surface side is changed or a structure for maintaining the strength is used, the cost is increased, and the number of parts is increased.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a seal structure of an internal combustion engine capable of improving the sealing performance without changing the cover shape and without increasing the number of parts and the cost.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a seal structure for an internal combustion engine, in which a chain cover is mounted on a mounting surface at an end of an engine body in which a cylinder block and a cylinder head are joined, and a gap is filled with a sealant. a seal groove formed in the mating surface provided along the periphery of the chain cover, formed larger as approaching the width and depth of the seal groove in the junction surface between the cylinder block and the cylinder head, further, the seal groove A rib that divides the groove width and extends in the groove direction is provided at a position where the groove width and the depth are increased .
[0008]
Further, in a seal structure of an internal combustion engine in which a chain cover is mounted on an attachment surface at an end portion of an engine body in which a cylinder block and a cylinder head are joined and a gap is filled with a sealant, the seal cover is provided along a peripheral edge of the chain cover. A seal groove is formed on the mating surface, and the width and depth of the seal groove are increased as approaching the joint surface between the cylinder block and the cylinder head. Further, a chain is formed on the mounting surface between the cylinder block and the cylinder head. The sealing groove is provided on the side of the tightening bolt for attaching the cover, on the side where the distance between the joint surface of the cylinder and the tightening bolt is longer .
[0009]
Further, in a seal structure of an internal combustion engine in which a chain cover is mounted on an attachment surface at an end portion of an engine body in which a cylinder block and a cylinder head are joined and a gap is filled with a sealant, the seal cover is provided along a peripheral edge of the chain cover. A sealing groove was formed on the mating surface, and the width and depth of the sealing groove were increased as approaching the joint surface between the cylinder block and the cylinder head, and the groove width and depth of the sealing groove were further increased. A rib that divides the groove width and extends in the groove direction is provided at the location, and of the tightening bolts for mounting the chain cover on the mounting surface between the cylinder block and the cylinder head, the tightening bolts are connected to the joint surface of the cylinder. The seal groove is provided on a side having a longer distance to a mounting bolt.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
When the chain cover is mounted on the mounting surface of the engine body, a sealing agent is applied to a mating surface provided along the periphery of the chain cover. At this time, a portion having a wide groove width can be filled high, and a portion having a groove depth can easily maintain the raised height.
Therefore, when the chain cover is fitted, the sealant flows even in the gap larger than the normal gap, so that the sealant is filled in a large amount, so that the sealant can be reliably filled. Also, the screw can be tightened so strongly that no distortion occurs.
[0011]
Also, due to the mounting structure of the chain cover, if the distance between the joint surface of the cylinder and each of the tightening bolts is long, a step is likely to be formed on the mating surface and it is difficult to absorb the tightening force. Therefore, a seal groove having a large groove width and a large groove depth is formed on the side where the distance between the joint surface of the cylinder and the tightening bolt is long, and a large amount of sealant is used. Thereby, the gap is filled.
[0012]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 1 and 2, a bolt hole 7 and seal grooves 8 and 9 are provided in the mating surface 6 of the chain cover 1. The joining surface s where the cylinder head 2 and the cylinder block 3 overlap each other forms a joining surface portion t in a linear manner on the mounting surface at the end. The bolt hole 7 formed on the cylinder block 2 side is located farther from the joint surface portion t than the bolt hole 7 formed on the cylinder head 3 side of the chain cover 1.
[0013]
The seal groove 9 on the side of the cylinder block 2 closest to the joint surface portion t has a wider width as it is closer to the joint surface portion t, and the closer groove width W1 is larger than the farther groove width W2. Further, as shown in FIG. 2, the depth D1 of the groove closer to the bonding surface t is larger than the depth D2 of the groove farther.
[0014]
By forming the seal grooves 8 and 9 of the chain cover 1 in this manner, the amount of the sealing agent m filled in the seal groove 9 closest to the joint surface t can be held larger than in the related art. As shown in the figure, the sealing agent m can be raised on the mating surface 6 more than before. When the chain cover 1 is mounted on the engine body with the bolts 4 and the bolts 4a and 4b, the end on the cylinder block 2 side using the bolts 4b is retracted so that a step p is formed in the joint surface portion t.
[0015]
In the configuration of the present invention, even when the step p at the joint surface t between the cylinder block 2 and the cylinder head 3 becomes large, the step p is filled with the sealing agent m, and the sealing property of the joint surface t is improved. Also, since the width W and the depth D of the seal groove 8 formed in the conventional chain cover 1 are only partially increased, the cost of the cover is not affected without affecting the strength of the cover and without increasing the number of parts. It can be easily implemented without up. In addition, in response to vibration, the thickness and width of the sealant m are increased, so that the vibration resistance is improved and the life is extended.
[0016]
The wide seal groove 9 provided with a rib 10 at the center thereof will be described with reference to FIGS. The rib 10 extending from the end of the seal groove 9 on the joining surface side to the middle part divides the groove width into two, and the sealant m is raised over the two divided grooves at the time of filling. In this case, the gap near the joining surface t of the mating surface 6 on the periphery of the chain cover is easily filled, and the sealing performance is improved. Further, the strength of the rib 10 and the swelling of the sealant by the rib 10 are facilitated, the rigidity of the mating surface 6 is increased, and the surface pressure is improved. This configuration can be easily implemented because the number of components does not change and the cost does not change much.
[0017]
【The invention's effect】
Since the present invention is configured as described above, a place where a larger amount of the sealing agent is provided on the mating surface of the chain cover than before can be formed, and the step formed on the mounting surface with the engine body is sufficiently filled with the sealing agent. Therefore, distortion at the time of mounting can be reduced and sealing performance can be improved. In addition, the life of each part is extended. In addition, since the size of the seal groove on the mating surface is merely changed, the number of parts and the cost are the same as those of the related art, so that it can be easily implemented.
Further, by providing the rib in the seal groove, the rigidity is increased, and the surface pressure and the sealability can be improved.
In addition, the seal groove is provided only in the cylinder block and the cylinder head where the distance between the joint surface and the bolt is longer, and the change operation is simple, so that the seal groove is widely used.
[Brief description of the drawings]
FIG. 1 is a partial back view of a chain cover according to an embodiment of the present invention.
FIG. 2 is a partial side view of the chain cover shown in FIG.
FIG. 3 is a partial rear view of a chain cover according to another embodiment.
FIG. 4 is a partial side view of the chain cover shown in FIG. 3;
FIG. 5 is a sectional view taken along the line AA shown in FIG. 3;
FIG. 6 is a partial side view of a conventional chain cover.
FIG. 7 is a front view of a conventional engine body and a chain cover.
FIG. 8 is a rear view of the chain cover shown in FIG. 7;
FIG. 9 is a partial rear view of the chain cover shown in FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chain cover 2 Cylinder block 3 Cylinder head 4a, 4b Tightening bolt 6 Fitting surface 9 Seal groove 10 Rib m Sealant t Joint surface

Claims (3)

In a seal structure for an internal combustion engine in which a chain cover is mounted on an attachment surface at an end portion of an engine body in which a cylinder block and a cylinder head are joined and a gap is filled with a sealant, a mating surface provided along a peripheral edge of the chain cover. A seal groove is formed in the seal groove, and the width and depth of the seal groove are formed larger as approaching the joint surface between the cylinder block and the cylinder head .
A seal structure for an internal combustion engine, wherein a rib that divides the groove width and extends in the groove direction is provided at a position where the groove width and the depth of the seal groove are increased . In a seal structure for an internal combustion engine in which a chain cover is mounted on an attachment surface at an end portion of an engine body in which a cylinder block and a cylinder head are joined and a gap is filled with a sealant, a mating surface provided along a peripheral edge of the chain cover. A seal groove is formed in the seal groove, and the width and depth of the seal groove are formed larger as approaching the joint surface between the cylinder block and the cylinder head.
The sealing groove is provided on the side of the tightening bolt for mounting the chain cover on the mounting surface between the cylinder block and the cylinder head, on the side where the distance between the joint surface of the cylinder and the tightening bolt is longer. Seal structure for internal combustion engine. In a seal structure for an internal combustion engine in which a chain cover is mounted on an attachment surface at an end portion of an engine body in which a cylinder block and a cylinder head are joined and a gap is filled with a sealant, a mating surface provided along a peripheral edge of the chain cover. A seal groove is formed in the seal groove, and the width and depth of the seal groove are formed larger as approaching the joint surface between the cylinder block and the cylinder head.
In a place where the groove width and depth of the seal groove are increased, a groove width is divided, and a rib extending in the groove direction is provided, and
The sealing groove is provided on the side of the tightening bolt for mounting the chain cover on the mounting surface between the cylinder block and the cylinder head, on the side where the distance between the joint surface of the cylinder and the tightening bolt is longer. Seal structure for internal combustion engine.

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