JPH1047158A - Chain cover structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the rigidity and sealing performance of a second mating part by providing a cylinder block and first and second mating parts for a cover side to be respectively abutted on first and second cylinder heads in a chain cover, and providing a projecting part which is projected outwardly on the second mating part on the cover side. SOLUTION: A timing chain 34 which is a driving force transmission mechanism for valve operation to be provided on one end side of a crankshaft of an internal combustion engine is covered with a chain cover 36. First and second mating parts 38, 40 on a cover side are provided on each end of the chain cover, and first and second mating parts 54, 56 on a head side are provided on each side in the width direction across the axis of the crankshaft on a cylinder head 8. A projecting part 64 which is projected outward of the internal combustion engine is provided on the second mating part 40 on the cover side astride an abutting part between the second mating part for the head of the cylinder block to constitute a second bank of the engine and the second mating part for the block of the second cylinder head 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain cover structure for an internal combustion engine, and more particularly, to improving the sealing performance of a second mating surface on the cover side of a chain cover and preventing leakage of lubricating oil. Can be easily implemented only by changing the shape of a part of the second mating surface on the cover side, without any significant increase in cost and weight, and without changing processing equipment or assembly man-hours. The present invention relates to a chain cover structure for an internal combustion engine that can be used.

[0002]

2. Description of the Related Art In an internal combustion engine of a vehicle or the like, a serial internal combustion engine having cylinders arranged in series, an internal combustion engine having opposed cylinders arranged opposite to each other, and cylinders are arranged in a V-shape. There are V-type internal combustion engines and the like.

FIGS. 4 to 6 show a V-type internal combustion engine. 4, reference numeral 102 denotes an internal combustion engine, 10
4 is a cylinder block, 106 is a first cylinder head,
108 is the second cylinder head, 110 is the first bank, 1
Reference numeral 12 denotes a second bank. This internal combustion engine 102 is substantially V
The first and second cylinder heads 106 and 108 are placed on the V-shaped cylinder block 104 via the first and second head gaskets 114 and 116, respectively, and the first and second banks 110 and 112 are formed in a V-shape. It is arranged.

The internal combustion engine 102 has a first bank 110
The first cylinder hole (not shown) of the cylinder block 104 forming the second bank 112 and the second cylinder hole (not shown) of the cylinder block 104 forming the second bank 112 are connected to the first head bolt of the first cylinder head 106 as shown in FIG. The hole 118 and the second head bolt hole 120 of the second cylinder head 108 are offset by an offset amount a.
As a result, the internal combustion engine 102 is
Are offset from the second bank 112 to one end side in the direction of the crankshaft axis A by an offset amount a.

As described above, the first bank 110 is offset from the second bank 112 to one end in the direction of the crankshaft axis A, and one end of the internal combustion engine 102 in the direction of the crankshaft axis A is provided by a valve train driving force transmission mechanism. A certain timing chain 1
22 are provided.

The timing chain 122 is covered by a chain cover 124. The chain cover 124 is provided with first and second mating surfaces 126 and 128 on the cover side, and the first and second mating surfaces 126 and 128 are respectively provided with the first and second mounting hole bosses 130 and 132 on the cover side. , Cover side first and second mounting holes 134 and 136 are provided.

The chain cover 124 has first and second mounting bolts 138 in first and second mounting holes 134 and 136 of the cover side first and second mounting hole bosses 130 and 132, respectively.
140 is inserted, and the cylinder block 104 and the first
By screwing into the mounting holes (not shown) on each side of the second cylinder heads 106 and 108, the timing chain 12
2 and the first and second cylinder heads 106 and 10 at one end in the direction of the crankshaft axis A.
8 to form a chain chamber 142.

The internal combustion engine 102 is, as shown in FIG.
At a portion where the three members of the cylinder block 104, the second cylinder head 108, and the chain cover 124 are joined, a step L occurs due to a variation in manufacturing tolerance, and the cover-side second mating surface 128 abuts on the head-side second mating surface 146. Surface pressure may be insufficient.

For this reason, there is a liquid between the cover-side second mating surface portion 128 of the chain cover 124, the block-side second mating surface portion 144 of the cylinder block 104, and the head-side second mating surface portion 146 of the second cylinder head 108. By applying or filling a gasket (not shown), leakage of lubricating oil from the chain chamber 142 is prevented.

Although not shown, the cylinder block 1
04, first cylinder head 106 and chain cover 12
Similarly, a liquid gasket (not shown) is applied or filled at a portion where the three members 4 and 4 are joined to prevent leakage of lubricating oil from the chain chamber 142.

[0011] As such a chain cover structure for a V-type internal combustion engine, there are those disclosed in JP-A-4-63954 and JP-A-4-119347.

Japanese Patent Laid-Open Publication No. 4-63954 discloses a cam chain arranged on one side in the axial direction of a crankshaft of an engine in which a cylinder head is attached to a cylinder block via a head gasket, and surrounds the cam chain. A cam chain cover attached to the cylinder block and the cylinder head, a notch provided in a part of the head gasket, and a core which engages with the notch and is provided with the cam chain cover to serve as an oil seal. An elastic member having a material is provided.

[0013] Japanese Utility Model Laid-Open Publication No. 4-119347 discloses a cylinder block and a chain case made of dissimilar materials disposed adjacent to each other. A cylinder head gasket is formed between the cylinder block and the cylinder head. In the engine seal structure that is sandwiched and joined, the portion of the cylinder block adjacent to the chain case is formed of a member made of the same material as the chain case, and the upper end surface is in contact with the lower surface of the cylinder head gasket cylinder head. It is provided so as to abut on a portion to be formed.

[0014]

In the internal combustion engine 102, the first bank 110 is connected to the second bank 1
12 is offset to one end side in the direction of the crankshaft axis A. Therefore, as shown in FIG. 5, the second bank 112 is offset from the first bank 110 at the one end in the crankshaft axis A by the offset amount a at one end in the crankshaft axis A direction. .

As a result, the distance between the second head bolt hole 120 of the second cylinder head 108 and the head-side second mating surface 146 with which the cover-side second mating surface 128 of the chain cover 124 abuts is the first distance. The distance from the first head bolt hole 118 of the cylinder head 106 to the head-side first mating surface 148 with which the cover-side first mating surface 126 of the chain cover 124 abuts is larger than the separation distance.

Therefore, during operation of the internal combustion engine 102,
The vibration of the three members of the cylinder block 104, the second cylinder head 108, and the chain cover 124 causes the head-side second mating surface 146 of the second cylinder head 108 to abut the cover-side second mating surface 128 of the chain cover 124. Adversely affect the sealing performance.

In particular, in the second bank 112, the rigidity of the chain chamber wall portion 150 on which the head side second mating surface portion 146 of the second cylinder head 108 is provided becomes insufficient, and the chain side second mating surface portion 128 vibrates. There is a disadvantage that the performance is reduced and lubricating oil leaks.

As countermeasures against such inconvenience, the rigidity of the chain chamber wall 150 is improved, and the number of tightening the second mounting bolts 140 is increased. However, the increase in the rigidity of the chain chamber wall 150 and the increase in the number of tightening the second mounting bolts 140 increase the cost, weight, and the number of parts due to the change in the shape of the second cylinder head 108. There is an inconvenience that changes the assembly man-hour.

[0019]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention mounts the first and second cylinder heads on a substantially V-shaped cylinder block, respectively, to form a first V-shaped cylinder block. A second bank is provided, and a valve train driving force transmission mechanism is provided at one end in the crankshaft axis direction of the internal combustion engine in which the first bank is offset to one end side in the crankshaft axis direction from the second bank. A chain cover that covers the valve train driving force transmission mechanism and is attached to the cylinder block and the first and second cylinder heads at one end in the axial direction of the crankshaft is provided. The chain cover constitutes the first bank. The cylinder block and the first
A cover-side first mating surface that is in contact with the cylinder head, and a cover-side second mating surface that is in contact with the cylinder block and the second cylinder head that constitute the second bank; The cover-side second mating surface is provided with a protruding portion that protrudes outward.

The projecting portion is provided on the side of the cover which straddles a portion where the second mating surface portion for the head of the cylinder block and the second mating surface portion for the block of the second cylinder head which constitute the second bank are in contact with each other. A cover provided on a second mating surface portion and straddling a portion where the second mating surface portion for the head of the cylinder block and the second mating surface portion for the block of the second cylinder head which constitute the second bank are in contact with each other; Two cover-side second mounting hole bosses respectively provided on the first side second mating surface portion are connected to each other, and further, the second mating surface portion for the head of the cylinder block constituting the second bank and the second cylinder Two cover-side second members respectively provided on the cover-side second mating surface portions that straddle a portion where the head comes into contact with the block second mating surface portions.
The mounting hole boss is provided so as to protrude so as to reach the outermost end face.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A chain cover according to the present invention has a structure in which the first bank is offset from the second bank to one end in the axial direction of the crankshaft. A projecting portion projecting outward is provided on the cover-side second mating surface that is in contact with the cylinder block of the second bank and the second cylinder head that are offset from the other end in the axial direction.

The projecting portion is a cover-side second mating surface that straddles a portion where the second mating surface for the head of the cylinder block constituting the second bank and the second mating surface for the block of the second cylinder head are in contact with each other. And a cover-side second mating surface portion straddling a portion where the second mating surface portion for the head of the cylinder block constituting the second bank and the second mating surface portion for the block of the second cylinder head are in contact with each other. The two cover-side second mounting hole bosses are connected to each other, and further, the contact between the head second mating surface of the cylinder block forming the second bank and the block second mating surface of the second cylinder head is performed. The two cover-side second members respectively provided on the cover-side second mating surface portion straddling the contacted portion.
The mounting hole is provided so as to protrude so as to reach the outermost end surface of the boss portion.

Thus, the chain cover covers the second side of the cover, which straddles the portion where the second mating surface for the head of the cylinder block constituting the second bank and the second mating surface for the block of the second cylinder head come into contact with each other. The rigidity of the mating surface can be improved by the protrusion.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes an internal combustion engine, 4 denotes a cylinder block, 6 denotes a first cylinder head, 8 denotes a second cylinder head, 10 denotes a first bank, and 12 denotes a second bank.

The internal combustion engine 2 has first and second mating surface portions 14 and 16 for heads formed on a substantially V-shaped cylinder block 4.
And the first and second cylinder heads are provided with first and second mating surfaces 18 and 20 for blocks, respectively.

The internal combustion engine 2 has first and second mating surfaces 14 and 16 for the head of the cylinder block 4, respectively.
The first and second mating surface portions 18 for the blocks of the first and second cylinder heads 6.8 via the head gaskets 22 and 24
The first and second cylinder heads 6 and 8 are placed by contacting the first and second cylinder heads 6 and 8 with the head bolts (not shown) of the respective sides and screwing the cylinder blocks 4 into the V-shaped first and second banks. 10.12 are provided.

As shown in FIG. 3, the internal combustion engine 2 has a first
As shown in FIG. 2, the first cylinder hole 26 of the cylinder block 4 forming the bank 10 and the second cylinder hole 28 of the cylinder block 4 forming the second bank 12 are connected to the first head bolt of the first cylinder head 6. The hole 30 and the second head bolt hole 32 of the second cylinder head 8 are offset by an offset amount a. Thereby, the internal combustion engine 2
The first bank 10 is offset from the second bank 12 to one end side in the direction of the crankshaft axis A by an offset amount a.

As described above, the valve driving drive is provided at one end of the internal combustion engine 2 in the direction of the crankshaft axis A, in which the first bank 10 is offset from the second bank 12 by one end a in the direction of the crankshaft axis A. A timing chain 34 as a force transmission mechanism is provided.

The timing chain 34 is covered by a chain cover 36. The chain cover 36 is provided with first and second cover-side mating surface portions 38 and 40 on each side in the width direction intersecting with the crankshaft axis A, and the first and second cover-side mating portions 38 and 40 are provided.
Cover-side first and second mounting hole bosses 42 and 44 are provided on the second mating surfaces 38 and 40, and cover-side first and second mounting holes 46 and 48 are provided.

Each of the cylinder blocks 4 is provided with a first block on each side in the width direction crossing the crankshaft axis A.
The second mating surface portions 50 and 52 are provided, and the block side first and second mounting holes (not shown) are provided. In addition, the first
The second cylinder heads 6 and 8 are respectively provided with head-side first and second mating surfaces 54 and 56 on respective sides in the width direction intersecting the crankshaft axis A, and the head-side first and second mounting holes ( (Not shown).

The chain cover 36 has first and second mating surface portions 38 and 40 on the cover side, and first and second mating surface portions 50 and 52 on the block side of the cylinder block 4 and the first and second cylinder heads 6 and 8, respectively. The first and second mounting surfaces 54 and 56 are brought into contact with the head side and the first and second mounting holes 46 and 48 of the cover side first and second mounting hole bosses 42 and 44 are respectively provided. By inserting the bolts 58 and 60 and screwing them into the first and second mounting holes (not shown) on each side of the cylinder block 4 and the first and second cylinder heads 6 and 8,
It is attached to the cylinder block 4 and the first and second cylinder heads 6.8 at one end side in the direction of the crankshaft axis A so as to cover the timing chain 34, and forms a chain chamber 62.

It should be noted that the chain cover 36 has first and second chains.
The space side between the banks 10 and 12 also covers the first and
First and second mounting surfaces 38 and 40 are provided, and are brought into contact with head-side first and second mating surfaces (not shown) on the space side of the first and second cylinder heads 6.8 to perform first and second mounting. Bolt 58
・ Attached by 60.

The cover-side first mating surface 38 of the chain cover 36, the block-side first mating surface 50 of the cylinder block 4, and the head-side first mating portion of the first cylinder head 6.
Between the mating surface 54 and the cover-side second mating surface 40 of the chain cover 36 with the block-side second mating surface 52 of the cylinder block 4 and the head-side second mating surface 56 of the second cylinder head 8. Prevents the leakage of lubricating oil from the chain chamber 62 by applying or filling a liquid gasket (not shown).

In the internal combustion engine 2, the first bank 10 is offset from the second bank 12 to one end in the direction of the crankshaft axis A, so that the second bank 12 is shifted to the first end in the direction of the crankshaft axis A. It is offset from the bank 10 by the offset amount a on the other end side in the direction of the crankshaft axis A.

As a result, the second cylinder head 8
The separation distance from the head bolt hole 32 to the head-side second mating surface portion 56 where the cover-side second mating surface portion 40 of the chain cover 36 comes into contact is the first distance of the first cylinder head 6.
The distance from the head bolt hole 30 to the head-side first mating surface 54 with which the cover-side first mating surface 38 of the chain cover 36 abuts is larger than the separation distance.

As shown in FIGS. 1 and 2, an internal combustion engine 2 is provided on the cover side second mating surface 40 of the chain cover 36.
Is provided with a protruding portion 64 protruding outward.

The projecting portion 64 is provided on the second mating surface 16 for the head of the cylinder block 4 constituting the second bank 12.
And the second mating surface 2 for the block of the second cylinder head 8
Cover side second mating surface portion 4 that straddles the portion that comes into contact with zero
0.

The projecting portion 64 is provided in the second bank 12.
2 provided on the cover-side second mating surface portion 40 that straddles the portion where the second head mating surface portion 16 of the cylinder block 4 and the second mating surface portion 20 for block of the second cylinder head 8 contact each other. The two cover-side second mounting hole bosses 44 are connected and provided.

Further, the projecting portion 64 is provided in the second bank 1
2 is provided on the cover-side second mating surface portion 40 that straddles a portion where the second head mating surface portion 16 of the cylinder block 4 and the second mating surface portion 20 for block of the second cylinder head 8 come into contact with each other. The two cover-side second mounting hole boss portions 44 are provided so as to protrude so as to reach the outermost end surfaces 66 of the boss portions 44.

As described above, the chain cover 36 is
The bank 10 is offset from the second bank 12 to one end in the direction of the crankshaft axis A, and the one end of the internal combustion engine 2 in the direction of the crankshaft axis A is offset from the first bank 10 to the other end in the direction of crankshaft axis A. A projecting portion 64 projecting outward is provided on the cover-side second mating surface portion 40 that is in contact with the cylinder block 4 and the second cylinder head 8 of the second bank 12 located.

The protruding portion 64 is provided on the cover-side second mating surface portion 40 that straddles the portion where the second head mating surface portion 16 and the second block mating surface portion 20 are in contact with each other.
The two cover-side second mounting hole boss portions 44 provided on the cover-side second mating surface portion 40 straddling the portion where the head second mating surface portion 16 and the block second mating surface portion 20 are in contact with each other. And two cover-side second mounting hole bosses respectively provided on the cover-side second mating surface portion 40 which straddles a portion where the second head mating surface portion 16 and the second block mating surface portion 20 are in contact with each other. Outermost end surface 66 of part 44
Is provided so as to protrude.

As a result, the chain cover 36 is
The rigidity of the cover-side second mating surface portion 40 that straddles the portion where the second head mating surface portion 16 of the cylinder block 4 constituting the bank 12 and the second mating surface portion 20 of the second cylinder head 8 come into contact with each other is projected. This can be improved by the part 64.

For this reason, even if the chain cover 36 vibrates due to the operation of the internal combustion engine 2, the vibration of the chain cover 36 is reduced with respect to the cover side second mating surface portion 40 where the surface pressure is insufficient. The sealing performance of the cover side second mating surface portion 40 of the chain cover 36 can be improved, and leakage of lubricating oil from the chain chamber 62 can be prevented.

The chain cover 36 has a projection 6 on the cover side second mating surface 42 of the chain cover 36.
4, the sealing performance can be improved and the lubricating oil can be prevented from leaking. Therefore, it can be easily carried out only by changing a part of the cover side second mating surface portion 40 of the chain cover 36, and the cost and weight are greatly reduced. The present invention can be easily implemented without increasing the number of the processing facilities and the number of assembling steps.

[0045]

As described above, according to the present invention, the chain cover is provided at one end in the crankshaft axial direction of the internal combustion engine in which the first bank is offset to one end in the crankshaft axial direction from the second bank. An outwardly projecting portion is provided on a cover-side second mating surface portion that is in contact with the cylinder block of the second bank and the second cylinder head that are offset from the other bank on the other end side in the axial direction of the crankshaft. With this configuration, the cover-side second mating surface portion straddling the portion where the protrusion mating surface portion of the cylinder block constituting the second bank and the block second mating surface portion of the second cylinder head come into contact with each other. The rigidity can be improved.

Therefore, even if the chain cover vibrates due to the operation of the internal combustion engine with respect to the cover side second mating surface portion where the surface pressure is insufficient, the vibration can be reduced by the projecting portion. The sealing performance of the cover side second mating surface portion of the chain cover can be improved, and leakage of lubricating oil can be prevented.

Further, in this chain cover, the sealing performance can be improved and lubricating oil can be prevented by merely providing a protrusion on the cover side second mating surface of the chain cover. It can be easily implemented only by changing a part of the shape, and can be easily implemented without causing a significant increase in cost and weight, and without requiring a change in processing equipment and assembly man-hours.

[Brief description of the drawings]

FIG. 1 is a front view of a chain cover of an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a plan view of a cylinder block.

FIG. 4 is a front view of a chain cover of an internal combustion engine showing a conventional example.

FIG. 5 is a partially enlarged sectional view taken along line VV of FIG. 4;

FIG. 6 is a partially enlarged side view taken along arrow の of FIG. 4;

[Explanation of symbols]

 Reference Signs List 2 internal combustion engine 4 cylinder block 6 first cylinder head 8 second cylinder head 10 first bank 12 second bank 34 timing chain 36 chain cover 38 cover-side first mating surface 40 cover-side second mating surface 42 cover-side first mounting Hole boss portion 44 Cover-side second mounting hole boss portion 64 Projection

Claims (4)

[Claims] A first and a second cylinder head are mounted on a substantially V-shaped cylinder block, and a first and a second bank are arranged in a V-shape.
A driving force transmission mechanism for a valve train is provided at one end side in the crankshaft axis direction of the internal combustion engine offset to one end side in the crankshaft axis direction from the bank, and the driving force transmission mechanism for the valve train is covered at one end side in the crankshaft axis direction. A chain cover attached to the cylinder block and the first and second cylinder heads is provided. The chain cover covers the cylinder block and the first cylinder head constituting the first bank, respectively. A first side mating surface portion is provided, and a second side mating surface portion on the cover side is provided which is in contact with the cylinder block and the second cylinder head constituting the second bank. A chain cover structure for an internal combustion engine, characterized in that a protruding portion is provided on the internal combustion engine. 2. The method according to claim 1, wherein the projecting portion straddles a portion where the second mating surface portion for the head of the cylinder block and the second mating surface portion for the block of the second cylinder head which constitute the second bank are in contact with each other. The chain cover structure for an internal combustion engine according to claim 1, wherein the chain cover structure is provided on the cover-side second mating surface portion. 3. The projecting portion straddles a portion where the second mating surface portion for the head of the cylinder block and the second mating surface portion for the block of the second cylinder head abut on each other. 2. The chain cover structure for an internal combustion engine according to claim 1, wherein two cover-side second mounting hole bosses respectively provided on the cover-side second mating surface are connected to each other. 3. 4. The protruding portion straddles a portion where the second mating surface portion for the head of the cylinder block and the second mating surface portion for the block of the second cylinder head that make up the second bank are in contact with each other. 2. The chain cover of an internal combustion engine according to claim 1, wherein the two cover-side second mounting hole bosses respectively provided on the cover-side second mating surface portion are provided so as to protrude so as to reach the outermost end surfaces. Construction.