JP3147709B2 - Chain guide for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain guide for an internal combustion engine, and more particularly to an improvement in the strength of a guide body for supporting a contact body, an improvement in durability of the guide body, and an increase in weight and It can be implemented in the conventional space without causing a significant increase in cost, can suppress the vibration of the chain cover and reduce engine noise, can improve the sealing performance between the chain cover and the cylinder head, and can reduce the weight. The present invention relates to a chain guide for an internal combustion engine that can be implemented by using a conventional space without increasing the cost and the cost.

[0002]

2. Description of the Related Art An internal combustion engine mounted on a vehicle includes a series internal combustion engine having cylinders arranged in series, an opposed internal combustion engine having cylinders opposed to each other, and a cylinder having a V-shape. V-type internal combustion engines.

As shown in FIG. 6, a V-type internal combustion engine 202
The lower case 206 is attached below the substantially V-shaped cylinder block 204 to support the crankshaft 208, and the oil pan 210 is attached to the lower case 206. The V-type internal combustion engine 202 has a cylinder block 204.
The cylinder heads 212R and 212L on the respective sides are placed above the, and the intake camshafts 214R and 214L on the respective sides and the exhaust camshafts 216R and 216L on the respective sides are pivotally supported. Each side head cover 218R / 218L is attached to each side cylinder head 212R / 212L to form a V-shaped side bank 2
20R and 220L are arranged.

The internal combustion engine 202 has a crankshaft axis A
The valve driving force transmission mechanism 222 is disposed at one end in the direction. The valve train driving force transmission mechanism 222 is connected to the crankshaft 20.
8 has a crank sprocket 224 at one end in the direction of the axis A.
Is installed. A right intake cam sprocket 226R and a right exhaust cam sprocket 228R are attached to one end of the right intake cam shaft 214R and the right exhaust cam shaft 216R in the direction of the axis A, respectively. Left intake camshaft 214L
A left intake cam sprocket 226L and a left exhaust sprocket 228L are attached to one end of the left exhaust cam shaft 216L in the direction of the axis A.

[0005] The right intake camshaft 214R further includes a crankshaft axis A of the right intake cam sprocket 226R.
A right intermediate sprocket 230 is attached to one end in the direction.

As shown in FIG. 5, a crankshaft 208 and a left intake camshaft 21 are attached to the left cylinder head 212L.
4L and the left exhaust camshaft 216L,
The left intermediate shaft 232 is attached to one end of the crankshaft axis A direction. The left intermediate shaft 232 is provided with a left intermediate sprocket 234 and a left camshaft sprocket 236 pivotally supported. The left intermediate sprocket 234 and the left camshaft sprocket 236 are integrally provided and supported by the left intermediate shaft 232.

An idle shaft 238 is attached to the cylinder block 204 between the banks 220R and 220L at one end in the direction of the axis A of the crankshaft, and an idle sprocket 240 is supported on the idle shaft 238. Have

The crank sprocket 224, the right intermediate sprocket 230 and the left intermediate sprocket 23
The timing chain 242 is wound around the idle sprocket 4 and the idle sprocket 240. The right intake cam sprocket 226R and the right exhaust cam sprocket 2
The right cam chain 244R is wound around the 28R. A left cam chain 244L is wound around the left intake cam sprocket 226L and the left exhaust cam sprocket 228L.

As a result, the valve driving force transmitting mechanism 222
When the crankshaft 208 of the V-type internal combustion engine 202 rotates clockwise (direction of arrow B), the rotation of the crankshaft 208 is controlled by the timing chain 242 to the right cam chain 24.
4R and the left side cam chain 244L, the respective intake camshafts 214R and 214L and the respective exhaust camshafts 216R.
216L to open and close each intake valve and each exhaust valve (not shown).

The valve driving force transmitting mechanism 222 has a chain tensioner 246 on the loose side of the timing chain 242 and chain guides 248 and 250 on the tight side of the timing chain 242. The chain tensioner 246 is pivotally supported by the right cylinder head 212 </ b> R so as to be swingable by a swing shaft 252.
, And is pushed toward the timing chain 242 to apply a predetermined tension. The chain guide 248 is attached to the right cylinder head 212R. The chain guide 250 is attached to the cylinder block 204.

The valve driving force transmitting mechanism 222 includes a right cam chain 244R and a left cam chain 244L.
Chain tensioner 256 that applies a predetermined tension to
R and a left chain tensioner 256L are provided respectively. The right chain tensioner 256R and the left chain tensioner 256L are connected to the right cylinder head 212, respectively.
It is attached to the R and left cylinder head 212L.

Further, the valve driving force transmitting mechanism 222 includes:
Right cam chain 244R and left cam chain 244
The right chain guide 258R and the left chain guides 258L and 260 for suppressing vibration are provided at L.
Right chain guide 258R and left chain guide 2
58L and 260 are attached to the right cylinder head 212R and the left cylinder head 212L, respectively. Reference numeral 262 denotes a chain cover.

A chain guide for such an internal combustion engine is disclosed in Japanese Utility Model Laid-Open No. 61-80330, Japanese Utility Model Laid-Open No. 3-49.
454 and Japanese Utility Model Laid-Open No. 3-77839.

The chain guide disclosed in Japanese Utility Model Laid-Open Publication No. Sho 61-80330 is provided by being attached to a chain cover via an elastic body.

The chain guide disclosed in Japanese Utility Model Laid-Open Publication No. 3-49454 is provided with a pair of guide members slidably contacting the cam chain on one of the outer peripheral side and the inner peripheral side of the cam chain. A guide member slidably contacting the cam chain is provided on one of the outer peripheral side and the inner peripheral side of the cam chain facing the intermediate portion of the guide member.

The chain guide disclosed in Japanese Utility Model Laid-Open Publication No. 3-77839 is composed of a guide piece that comes into contact with the chain and a mounting piece that is mounted on an installation surface at right angles to the guide piece. A projection is formed on at least one of the attachment pieces and a portion separated from the installation surface.

[0017]

In the valve driving force transmitting mechanism 222, the chain guides 248 and 250 are provided on the timing chain 242, and the right chain guide 258R and the right chain guide 258R are provided on the right cam chain 244R and the left cam chain 244L, respectively. Left chain guide 258L
・ 260 is provided.

Each of the chain guides 248, 250, and 2
The chain guide 260 attached to the left cylinder head 212L of the 58R, 258L, 260 is shown in FIG.
As shown in the figure, the contact body 264 and the guide body 266 are provided. The contact body 264 is a left cam chain 244L.
The vibration is suppressed by being brought into contact with either one of the outer side surface 268 and the inner side surface 270. In the illustrated example, the contact body 264
Is in contact with the outer surface 268 of the left cam chain 244L.

The guide main body 266 includes a main body support 27.
2 and the main body mounting portion 274 are formed in a substantially L-shape. The contact body 264 is supported and provided on the main body support portion 272. The main body mounting portion 274 is connected to the main body support portion 2.
72 is formed on one side in the width direction of the left cam chain 244L via a bent portion 276 to form a mounting hole 278.

The guide main body 266 makes the contact body 264 supported by the main body support portion 272 contact the outer side surface 268 of the left cam chain 244L, and the mounting bolt 280 inserted through the mounting hole 278 of the main body mounting portion 274 to the left. The cylinder head 212L is attached to the left cylinder head 212L by being screwed into the attachment screw hole 284 of the attachment boss 282 of the cylinder head 212L.

However, in order to make the mounting of the chain guide 260 compact, the mounting boss 282 to which the main body mounting portion 274 is mounted is positioned between one side in the width direction of the left cam chain 244L and the left cylinder head 212L. In addition, the guide body 266 is formed in a substantially L-shape to have a cantilever structure.

For this reason, when the left cam chain 244L vibrates in the directions of the outer side surface 268 and the inner side surface 270 (vertical direction in FIG. 4), the chain guide 260 is provided with the bent portion 276 of the guide main body 266 and the main body mounting portion. Stress concentrates on 274, causing a problem in strength and lowering durability.

As countermeasures against such inconvenience, the thickness of the guide body 266 is increased to improve the strength,
Reinforcement by ribs or the like is conceivable.

However, increasing the thickness or reinforcing the ribs has the disadvantage of increasing the weight and the cost.

Further, as a support structure of the chain guide, as disclosed in Japanese Utility Model Application Laid-Open No. 61-80330, there is a structure in which a chain guide is attached to a chain cover via an elastic body.

However, the chain cover disclosed in this publication has a disadvantage that the vibration of the chain is amplified by the transmission of the vibration of the chain due to the attachment of the chain guide, and the vibration is amplified and the noise is released, as shown in FIG. There is a disadvantage that the seal between the head side mating surface 286 of the cylinder head 212L and the cover side mating surface 288 of the chain cover 262 is damaged by vibration, causing oil leakage.

In order to suppress such vibration of the chain cover, it is conceivable to increase the wall thickness or add a reinforcing rib. However, as described above, there is a disadvantage that the weight increases and the cost increases.

[0028]

SUMMARY OF THE INVENTION Accordingly, in order to eliminate the above-mentioned disadvantages, the present invention provides a contact that contacts one of an outer surface and an inner surface of a chain that transmits rotation of a crankshaft of an internal combustion engine. A body is provided to support the contact body on a main body support portion of the guide main body, and a main body mounting portion mounted to a cylinder head of the internal combustion engine is formed and provided on one side of the main body support portion in the width direction of the chain. An inner surface of a chain cover attached to the cylinder head to cover the chain by providing an engaging projection by extending and covering an end of the main body supporting portion on the other side in the width direction of the chain with the contact body; Forming and providing an engagement concave portion with which the engagement protrusion is engaged, and forming and providing a fastening boss portion on the chain cover at each end portion of the guide body in the running direction of the chain, this Boss portions with the clamping is characterized by comprising forming a length from the cover side mating surface of the one widthwise side of the chain reaches the engaging Gokubo portion in the width direction of the other side.

[0029]

According to the structure of the present invention, the chain guide
A contact body that contacts one of the outer surface and the inner surface of the chain is provided to be supported by the main body support of the guide main body, and a main body mounting portion that is attached to the cylinder head on one side of the main body support in the width direction of the chain. Is formed and provided with an engagement protrusion formed by extending and covering the edge of the main body supporting portion on the other side in the width direction of the chain with a contact body, and the engagement protrusion is formed on the inner surface of the chain cover that covers the chain. The guide body is supported by the cylinder heads and the chain covers on both sides by forming the engagement recesses to be engaged, and when the chain vibrates, the guide body is stressed like a conventional cantilever structure. Concentration can be avoided, and the strength can be improved without requiring an increase in thickness or rib reinforcement. Also, the chain cover is provided with a fastening boss formed at each end of the guide body at both ends in the running direction of the chain, and each of the fastening bosses is formed from a cover side mating surface on one side in the width direction of the chain. By being formed so as to reach the engagement recess on the other side in the width direction, the support rigidity of the chain cover can be increased, and the vibration of the chain cover can be suppressed.

[0030]

An embodiment 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. 3, reference numeral 2 denotes a V-type internal combustion engine mounted on a vehicle. In the V-type internal combustion engine 2, a lower case 6 is mounted below a substantially V-shaped cylinder block 4 to support a crankshaft 8, and an oil pan 10 is mounted on the lower case 6.

The V-type internal combustion engine 2 has cylinder heads 12R and 12L on each side above the cylinder block 4.
Are mounted, and the respective intake camshafts 14R, 14L and the respective exhaust camshafts 16R, 16L are supported. Each of the cylinder heads 12R and 12L has a head cover 18R and 1 on each side.
8L is attached, and the side banks 20R and 20L are arranged in a V-shape.

The internal combustion engine 2 has a valve driving force transmission mechanism 22 at one end in the direction of the crankshaft axis A.
The valve train driving force transmission mechanism 22 has a crank sprocket 24 attached to one end of the crankshaft 8 in the direction of the axis A. A right intake cam sprocket 26R and a right exhaust cam sprocket 28R are attached to one end of the right intake cam shaft 14R and the right exhaust cam shaft 16R in the direction of the axis A, respectively. Left intake camshaft 14L and left exhaust camshaft 16
A left intake cam sprocket 26L and a left exhaust cam sprocket 28L are attached to L at one end in the direction of the axis A.

A right intermediate sprocket 30 is attached to the right intake camshaft 14R at one end of the right intake cam sprocket 26R in the direction of the crankshaft axis A.

The left cylinder head 12L has a crankshaft 8, a left intake camshaft 14L and a left exhaust camshaft 1 attached thereto.
6L, a left intermediate shaft 32 is attached to one end of the crankshaft axis A direction. The left intermediate shaft 32 is provided with a left intermediate sprocket 34 and a left camshaft sprocket 36 so as to be pivotally supported. The left intermediate sprocket 34 and the left cam shaft sprocket 36 are provided integrally and are supported by the left intermediate shaft 32.

An idle shaft 38 is mounted on the cylinder block 4 at one end in the direction of the crankshaft axis A, located between the banks 20R and 20L.
8 is provided with an idle sprocket 40 pivotally supported.

The crank sprocket 24, the right intermediate sprocket 30R and the left intermediate sprocket 34L
A timing chain 42 is wound around the idle sprocket 40 and the idle sprocket 40. A right cam chain 44R is wound around the right intake cam sprocket 26R and the right exhaust cam sprocket 28R. A left cam chain 44L is wound around the left intake cam sprocket 26L and the left exhaust cam sprocket 28L.

As a result, the valve driving force transmitting mechanism 22
Means that the crankshaft 8 of the V-type internal combustion engine 2 rotates clockwise (arrow B)
Direction), the rotation of the crankshaft 8 is controlled by the timing chain 42 through the right cam chain 44R and the left cam chain 44L to the respective intake camshafts 14R and 14L.
Then, the transmission is transmitted to the respective exhaust camshafts 16R and 16L to open and close the respective intake valves and the respective exhaust valves (not shown).

The valve driving force transmitting mechanism 22 includes a chain tensioner 46 on the loose side of the timing chain 42.
Are provided, and chain guides 48 and 50 are provided on the tension side of the timing chain 42. Chain tensioner 46
The right cylinder head 1 is pivotally movable by a pivot shaft 52.
2R, and is pushed toward the timing chain 42 by the adjuster 54 to apply a predetermined tension. The chain guide 48 is attached to the right cylinder head 12R. The chain guide 50 is connected to the cylinder block 4
Mounted on

The valve driving force transmitting mechanism 22 includes a right chain tensioner 56R and a left chain tensioner 56L for applying a predetermined tension to the right cam chain 44R and the left cam chain 44L, respectively. Right chain tensioner 56R and left chain tensioner 5
6L are attached to the right cylinder head 12R and the left cylinder head 12L, respectively.

Further, the valve driving force transmitting mechanism 22 is provided with a right chain guide 58R and left chain guides 58L and 60 for suppressing vibration on the right cam chain 44R and the left cam chain 44L, respectively. The right chain guide 58R and the left chain guide 58L / 60 are
They are mounted on the right cylinder head 12R and the left cylinder head 12L, respectively. Reference numeral 62 denotes a chain cover.

In the valve driving force transmission mechanism 22, the timing chain 42 is provided with chain guides 48 and 50,
A right chain guide 58R and left chain guides 58L and 60 are provided on the right cam chain 44R and the left cam chain 44L, respectively.

Each of the chain guides 48, 50, 58R
The chain guide 60 attached to the left cylinder head 12L among the 58L and 60 includes a contact body 64 and a guide body 66 as shown in FIGS. The contact body 64 is formed of an elastic member and has an outer surface 68 and an inner surface 7 of the left cam chain 44L formed in an endless annular shape.
Vibration is suppressed by being brought into contact with either one of zero. In the illustrated example, the contact body 64 is in contact with the outer side surface 68 of the left cam chain 44L.

The guide main body 66 is formed in a substantially L-shape by a main body support portion 72 and a main body mounting portion 74. The contact body 64 is supported and provided on the main body support portion 72. The main body mounting portion 74 is formed continuously on one side in the width direction of the left cam chain 44L of the main body supporting portion 72 via a bent portion 76, and forms a mounting hole 78.

The guide main body 66 is formed by extending and covering the edge 80 on the other side in the width direction of the left cam chain 44L of the main body supporting portion 72 with the contact member 64 made of the elastic member. 82 are formed and provided.

A mounting boss 84 is formed and provided on the left cylinder head 12L, and a mounting screw hole 86 is formed in the mounting boss 84. The mounting boss 84 is provided between one side in the width direction of the left cam chain 44L and the left cylinder head 12L. The inner surface 88 of the chain cover 62 attached to the left cylinder head 12L and covering the left cam chain 44L includes
An engagement recess 90 to which the engagement protrusion 82 is engaged is formed and provided.

The chain cover 62 is provided with a cover-side mating surface 94 so as to match the head-side mating surface 92 of the left cylinder head 12L, and formed and provided with a fastening boss 96. The tightening hole 1 is formed in the tightening boss 96 so as to match the tightening screw hole 98 of the left cylinder head 12L.
00 is formed and provided.

The chain cover 62 is provided with fastening bosses 96 formed at both ends of the guide body 66 in the running direction of the left cam chain 44L.
As shown in FIG. 1, each of the fastening bosses 96 is formed to have a length extending from the cover side mating surface 94 on one side in the width direction of the left cam chain 44L to the engaging recess 90 on the other side in the width direction. Provided. Thereby, each fastening boss portion 96 is formed to have a length substantially corresponding to the height of the chain cover 62 in the direction of the crankshaft axis A.

Next, the operation will be described.

The chain guide 60 brings the contact body 64 into contact with the outer surface 68 of the left cam chain 44L, and the mounting bolt 102 inserted through the mounting hole 78 of the main body mounting portion 74 into the mounting screw hole 86 of the mounting boss portion 84. By screwing,
It is attached to the left cylinder head 12L. The chain cover 62 is configured such that the cover side mating surface 94 is matched with the head side mating surface 92 and the tightening bolt 104 inserted into the tightening hole 100 of the tightening boss portion 96 is screwed into the tightening screw hole 98. Attached to the left cylinder head 12L.

The guide main body 66 having the main body mounting portion 74 mounted on the left cylinder head 12L is formed of an elastic member formed by extending and covering with a contact body 64 by mounting the chain cover 62 on the left cylinder head 12L. The collision portion 82 is attached to the inner surface 88 of the chain cover 62.
Is engaged with the engagement recessed portion 90.

As a result, the chain guide 60 is provided on both sides in the width direction of the guide main body 66 on the left cylinder head 12.
When the left cam chain 44L vibrates, supported by the L and the chain cover 62, it is possible to avoid concentration of stress on the bent portion 76 as in the conventional cantilever structure,
Strength can be improved without requiring an increase in thickness or rib reinforcement. For this reason, the chain guide 60 can improve the strength of the guide body 66, and
6 can be improved, and since there is no need to increase the thickness or the rib reinforcement, the weight and the cost are not significantly increased.

The chain guide 60 is attached to the chain cover 62 on the left cam chain 4 of the guide body 66.
Each of the fastening bosses 9 is located at each end of the 4L in the running direction.
6, and each of the tightening bosses 96 is formed to have a length extending from the cover side mating surface 94 on one side in the width direction of the chain to the engaging recess 90 on the other side in the width direction. Thereby, the support rigidity of the chain cover 62 can be increased, and the vibration of the chain cover 92 can be suppressed.

For this reason, this chain guide 60
The tightening by the three tightening bosses 96 can suppress the vibration of the chain cover 62 and reduce the engine noise, and the mating surfaces 92 and 94 between the chain cover 62 and the left cylinder head 12L by suppressing the vibration. Can be improved by using the conventional space without increasing the weight and the cost.

[0054]

As described above, according to the present invention, the chain guide has a structure in which the guide main body is supported by the cylinder heads and the chain covers on both sides, and is similar to a conventional cantilever structure when the chain vibrates. Concentration can be avoided, and the strength can be improved without requiring an increase in thickness or rib reinforcement. For this reason, this chain guide can improve the strength of the guide main body that supports the contact body, can improve the durability of the guide main body, and can increase the conventional space without increasing the weight and the cost. Can be carried out.

Further, the chain guide is located at both ends of the guide body in the running direction of the chain and is tightened by a tightening boss formed to extend from one side in the width direction of the chain to the other side in the width direction. Thus, the support rigidity of the chain cover can be increased and the vibration of the chain cover can be suppressed. Therefore, this chain guide can suppress the vibration of the chain cover and reduce the engine noise, can improve the sealing performance of the mating surface between the chain cover and the cylinder head, increase the weight and significantly increase the cost. It can be implemented with conventional space without significant increase.

[Brief description of the drawings]

FIG. 1 shows a chain guide according to an embodiment of the present invention; FIG.
FIG. 2 is an enlarged sectional view taken along line II of FIG.

FIG. 2 is an enlarged front view of a left bank of the internal combustion engine.

FIG. 3 is a front view of the internal combustion engine with a chain cover removed.

FIG. 4 is a chain guide showing a conventional example, IV-I in FIG. 6;
It is an expanded sectional view by the V line.

FIG. 5 is an enlarged sectional view taken along line VV in FIG. 6;

FIG. 6 is a front view of the internal combustion engine with a chain cover removed.

[Explanation of symbols]

 2 Internal combustion engine 4 Cylinder block 8 Crankshaft 12R Right cylinder head 12L Left cylinder head 42 Timing chain 44R Right cam chain 44L Left cam chain 60 Chain guide 62 Chain cover 64 Contact body 66 Guide body 68 Outer surface 70 Inner surface 72 Body support 74 body attachment portion 76 bent portion 78 attachment hole 80 end edge 82 engagement protrusion 90 engagement recess 96 fastening boss

Claims (1)

(57) [Claims] 1. A contact body that contacts one of an outer surface and an inner surface of a chain that transmits rotation of a crankshaft of an internal combustion engine is provided, and the contact body is provided to be supported by a main body supporting portion of a guide main body. A main body mounting portion is provided on one side of the main body supporting portion in the width direction of the chain, the main body mounting portion being mounted on a cylinder head of the internal combustion engine, and the end of the main body supporting portion on the other side in the width direction of the chain is contacted with the main body supporting portion. An engaging projection is formed by extending and covering with a body to form an engaging projection, and an engagement recessed portion to which the engaging projection is engaged is formed on an inner surface of a chain cover attached to the cylinder head and covering the chain. Provided , said
The chain cover of the guide body is attached to the chain cover.
Forming fastening bosses at both ends in the row direction
And each of these fastening bosses is located on one side in the width direction of the chain.
From the mating surface on the cover side to the other side in the width direction of the chain
A chain guide for an internal combustion engine, wherein the chain guide is formed to have a length that reaches the engagement recess .