JP2001182790A - Chain tensioner device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the compact chain tensioner device of an internal combustion engine which draws a chain to give proper tension to the chain, when it is pushed to a tensioner by an adjuster. SOLUTION: The chain tensioner device 30 of the internal combustion engine 2 provides the chain 20 winding around crank sprockets 16, 18 with crankshafts 10, 12 of the internal combustion engine 2 and a cam sprocket 14 with a cam shaft 8, and draws the chain 20 to give proper tension to the chain 20 when it is pushed to the tensioner 26 by the adjuster 28. The tensioner 26 is mounted outside the chain 20, and the adjuster 28 is dislocated inside the chain 20 on a cylinder head 6, to direct the load front the loose side of the chain 20 towards the tension side. The tensioner arm 32, which connects the adjuster 28 with the tensioner 26, has a curved shape arm having C cross section projecting from the surface of the internal combustion engine 2, partly covering the adjuster. The end of tensioner arm 32 is mounted to the tensioner 26 and another end is fixed with the pad of the adjuster 28, by which the tensioner arm 32 is attached to the adjuster 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain tensioner device for an internal combustion engine, and more particularly to a chain tensioner device for an internal combustion engine that pulls in a chain when an adjuster presses the chain to apply an appropriate tension to the chain.

[0002]

2. Description of the Related Art An engine has a crankshaft that converts a reciprocating motion of a piston into a rotary motion. The driving force, which is the rotational force from the crankshaft, is transmitted to, for example, a camshaft, and the camshaft converts the rotating operation into an opening and closing operation of an intake and exhaust valve.

At this time, a chain is wound around a crank sprocket mounted on the crankshaft and first and second cam sprockets mounted on two first and second camshafts respectively. It is a driving force transmission path.

A tensioner is provided near the chain, and the tensioner is pressed against the chain by an adjuster to apply an appropriate tension to the chain.

[0005] As the chain tensioner device for the internal combustion engine, there is one disclosed in Japanese Utility Model Publication No. 1-306682. The chain tensioner disclosed in this publication,
A bending allowance is provided at the tip of the rod, which is biased by a spring in the direction in which the chain tensioner is pressed against the chain, and which cannot be moved in the opposite direction to the biasing direction of the spring by a ratchet, by bending the rod into a U-shape. By connecting the spring plate, the front end of the panel plate is hooked to the front end of the chain tensioner, and the spring plate absorbs the axial distance between the sprockets around which the chain is generated due to the heat change due to engine cold and warm. And prevent the chain from being overstretched.

[0006]

In a conventional chain tensioner for an internal combustion engine, as shown in FIG. 5, a crank sprocket 114, an intake first cam sprocket 116, and an exhaust A second side cam sprocket 118 is provided, and a chain 120 is wound around the crank sprocket 114 and the first and second cam sprockets 116 and 118.

Since the chain 120 causes tooth skipping and noise during operation, the first guide portion 122 is disposed on the tight side of the chain 120, that is, near the outside of the right chain 120 in FIG. A second guide 124 is provided between the first and second cam sprockets 116 and 118 and near the outside of the chain 120,
The chain 120 on the loose side, ie, the left side chain in FIG.
A tensioner 126 is swingably disposed in the vicinity of the outside.

An adjuster 128 is provided on the cylinder block 106 outside the chain 120 and outside the swinging end of the tensioner 126 to press the tensioner 126.

Then, the tensioner 126 is pressed against the chain 120 by the pushing force of the adjuster 128,
Proper tension is secured.

As a result, in the configuration in which the tensioner is pressed, the adjuster is provided outside the chain and outside the swinging end of the tensioner, so that the width of the cylinder head and the cylinder block in the width direction becomes large. There is a disadvantage that it is difficult to make the layout compact and the weight increases, which is disadvantageous in practical use.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a chain for winding a crank sprocket mounted on a crankshaft of an internal combustion engine and a cam sprocket mounted on a camshaft in order to eliminate the above-mentioned disadvantages. In a chain tensioner device for an internal combustion engine that applies a proper tension to the chain by pressing a tensioner on the chain by an adjuster, a tensioner is attached to the outside of the chain, and a load direction is applied to a cylinder head inside the chain so that the load direction is on the loose side of the chain. The adjuster is disposed so as to be directed from the tensioner to the tension side, and a tensioner arm connecting the adjuster and the tensioner is formed into a curved shape having a cross section C that protrudes toward the surface side of the internal combustion engine so as to cover a part of the adjuster. When one end of this tensioner arm is attached to the tensioner The pad of the adjuster fixed to the other end, the tensioner arm through the pad may be mounted on the adjuster.

[0012]

According to the invention as described above, when the adjuster disposed between the tension side and the loose side of the chain presses the chain, the tension is pulled by the tension adjusting means to apply an appropriate tension to the chain, and the cylinder head and the cylinder are adjusted. The size of the block in the width direction is reduced, thereby achieving a compact layout.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a four-cycle internal combustion engine mounted on an automobile (not shown), 4 denotes a cylinder head, and 6 denotes a cylinder block.

The internal combustion engine 2 includes a cylinder head 4 and
And a cylinder block 6 mounted on the lower surface of the cylinder head 4.

A crankshaft 8 is provided on the lower surface of the cylinder block 6 so as to be pivotally supported. Two intake first camshafts 10 and an exhaust second camshaft 10 are provided on the cylinder head 4.
The camshaft 12 is provided so as to be pivotally supported.

And one end of the crankshaft 8;
That is, the crank sprocket 14 is mounted on the front side, which is one side of the internal combustion engine 2, and the first and second cam sprockets 16 and 18 are mounted on one ends of the first and second camshafts 10 and 12, respectively. Crank sprocket 1
4 and the first and second cam sprockets 16 and 18 are provided by winding the timing chain 20.

The tension side of the chain 20, that is, FIG.
In the above, a first guide portion 22 is provided near the outside of the right chain 20 and a second guide portion 24 is provided between the first and second cam sprockets 16 and 18 and near the outside of the chain 20. A tensioner 26 is disposed on the loose side of the chain 20, that is, near the outside of the chain 20 on the left side in FIG. 1, and the tensioner 26 is mounted on the cylinder block 6 so as to be swingable about the lower end.

Between the tension side and the loose side of the chain 20,
That is, an adjuster 28 is disposed on the cylinder head 4 inside the chain 20 so that the load direction is directed from the loose side of the chain 20 to the tight side, and the tensioner arm 32 connecting the adjuster 28 and the tensioner 26 is connected to the adjuster 28. The tensioner arm 32 is formed in a curved shape having a cross section C that protrudes toward the surface of the internal combustion engine 2 so as to cover a part of the tensioner arm. One end of the tensioner arm 32 is attached to the tensioner 26, and the pad 36 of the adjuster 28 is fixed to the other end. The tensioner arm 32 is connected to the adjuster 28 via the pad 36.
It is configured to be attached to.

More specifically, a tension adjusting means 30 for applying an appropriate tension to the chain 20 includes a tensioner 26, and a tensioner arm 32 which is an extension plate connecting the tensioner 26 and the adjuster 28.
And a fixing bolt 34 for fixing one end of the tensioner arm 32 to the tensioner 26.

When the adjuster 28 is disposed on the cylinder head 4 inside the chain 20, the load direction, which is the direction in which the adjuster 28 is pushed out of a plunger 38, which will be described later, is directed rightward in FIGS. It is arranged as much as possible.

Then, one end of the tensioner arm 32 is fixed to the tensioner 26 by a fixing bolt 34 from one side surface of the internal combustion engine 2. At this time, the wear-resistant pad 36 of the adjuster 28 is fixed to the other end of the tensioner arm 32, and the pad 3
6, the tensioner arm 32 is connected to the adjuster 28.
Attached to.

Further, the tensioner arm 32 is formed in a curved shape protruding toward the surface side of the internal combustion engine 2 to avoid interference with the adjuster 28 while surrounding a part of the adjuster 28.

That is, the tensioner arm 32 is formed in an annular shape as shown in FIG. 1, and is formed in a C-shaped cross section as shown in FIG. 2, so that the tensioner arm 32 and the adjuster 28 surround a part of the adjuster 28. Avoid interference and ensure high rigidity.

Further, a pad 36 of the adjuster 28 is fixed to the other end of the tensioner arm 32. In order to ensure the transmission of the load between the pad 36 and the tip of the plunger 38 of the adjuster 28. That is, in order to prevent the generation of an extra component when the tensioner arm 32 swings together with the tensioner 26, the contact side of the pad 36 is formed in an arc shape as shown in FIG.

Next, the operation will be described.

The plunger 38 of the adjuster 28 is
When projecting rightward in FIGS. 1 and 2 by the urging force of the spring or the hydraulic pressure, the tip of the plunger 38
Is pressed, and the tensioner 26 is
, And the tensioner 26 is pressed against the chain 20 to apply an appropriate tension to the chain 20.

At this time, the pad 36 transmits the load from the adjuster 28 to the tensioner arm 32 while changing the contact position with the tip of the plunger 38 up and down by the swinging operation of the tensioner 26.

As a result, the adjuster 28 can be arranged between the tension side and the loose side of the chain 20, and the dimensions of the cylinder head 4 and the cylinder block 6 in the width direction can be made small, and the weight can be reduced. It is practically advantageous.

If the internal combustion engine 2 is mounted on a four-wheeled vehicle, the engine room can be made smaller and the cabin volume can be made larger, and the fuel efficiency can be improved by reducing the weight.

Further, the provision of the tension adjusting means 30 can be used without changing the conventional adjuster function, which is practically advantageous.

Further, the tension adjusting means 30 includes a tensioner 26, a tensioner arm 32 for connecting the tensioner 26 and the adjuster 28, and a fixing bolt 3 for fixing one end of the tensioner arm 32 to the tensioner 26.
4, the pressing force of the adjuster 28 can be reliably transmitted to the tensioner 26 via the tensioner arm 32, and the chain 20 can be pulled in by the tensioner 26 to apply an appropriate tension to the chain 20. It is.

FIGS. 3 and 4 show a second embodiment of the present invention. In the second embodiment, portions that perform the same functions as those in the first embodiment will be described with the same reference numerals.

In the first embodiment, the tension adjusting means 30 includes a tensioner 26, a tensioner arm 32 connecting the tensioner 26 and the adjuster 28, and a fixing bolt for fixing one end of the tensioner arm 32 to the tensioner 26. The feature of the second embodiment is that the tension adjusting means 40 is integrally formed.

That is, as shown in FIGS. 3 and 4, a tensioner portion, the tensioner portion and the adjuster 2
A tension transmission section is formed integrally with a tensioner arm section communicating with the tension transmission section 8 and functions as tension adjustment means.

Further, as shown in FIG. 3, the tension transmitting portion 42 is formed to have a C-shaped cross section projecting toward the surface of the internal combustion engine 2 and, as shown in FIG.
The adjuster 28 surrounds a part of the adjuster 28.
To avoid interference and ensure high rigidity.

When the plunger 38 of the adjuster 28 projects rightward in FIGS. 3 and 4 by the urging force of the spring or the hydraulic pressure, the tip of the plunger 38 pushes the pad 36 and the tensioner of the tension transmitting portion 42 The tensioner portion is pulled in through the arm portion, and the tensioner portion can be pressed against the chain 20 to apply an appropriate tension to the chain 20.

Thus, the adjuster 28 can be disposed between the tension side and the loose side of the chain 20, and the cylinder head 4 and the cylinder block 6 can be moved in the width direction similarly to the first embodiment. It is practically advantageous because the size can be reduced to be compact and the weight can be reduced.

If the internal combustion engine 2 is mounted on a four-wheeled vehicle, the engine room can be made smaller and the cabin volume can be made larger, as in the case of the first embodiment. Can be improved.

Further, the provision of the tension adjusting means 40 allows the conventional adjuster function to be used without changing the same as in the first embodiment, which is practically advantageous.

Further, as the tension adjusting means 40,
Tensioner part, this tensioner part and adjuster 2
By using the tension transmitting portion 42 formed integrally with the tensioner arm portion communicating with the fixing member 8, a fixing bolt is not required, the number of parts can be reduced, and the same as in the first embodiment described above. In addition, the pressing force of the adjuster 28 can be reliably transmitted to the tensioner portion via the tensioner arm portion of the tension transmission portion 42, and the chain 20 is pulled in by the tensioner portion.
An appropriate tension can be applied to the chain 20.

[0042]

As described above in detail, according to the present invention, a chain for winding a crank sprocket mounted on a crankshaft of an internal combustion engine and a cam sprocket mounted on a camshaft is provided. A chain tensioner device for an internal combustion engine that applies an appropriate tension to the chain by pressing the tensioner with an adjuster, a tensioner is attached to the outside of the chain, and the load direction is directed to the cylinder head inside the chain from the loose side of the chain to the tight side. An adjuster is provided, and a tensioner arm that connects the adjuster and the tensioner is formed in a curved shape having a cross section C that protrudes toward the surface of the internal combustion engine so as to cover a part of the adjuster, and one end of the tensioner arm is connected to the tensioner. Attach the adjuster pad to the other end and attach Since the tensioner arm is mounted on the adjuster via the arm, the adjuster can be disposed between the tension side and the loose side of the chain, and the cylinder head and the cylinder block can be made compact to reduce the weight. This is practically advantageous. Also,
If the internal combustion engine is mounted on a four-wheeled vehicle, the engine room can be reduced, the cabin volume can be increased, and the fuel efficiency can be improved by reducing the weight.
Further, the conventional adjuster function can be used without changing the function, and the chain can be pulled in by the pressing force of the adjuster to apply an appropriate tension to the chain, which is practically advantageous.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a chain tensioner device for an internal combustion engine showing a first embodiment of the present invention.

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

FIG. 3 shows a second embodiment of the present invention, and FIG.
It is an expanded sectional view by the II line.

FIG. 4 is a schematic front view of a tensioner device of the internal combustion engine.

FIG. 5 is a schematic front view of a chain tensioner device for an internal combustion engine showing a conventional technique of the present invention.

[Explanation of symbols]

 Reference Signs List 2 internal combustion engine 4 cylinder head 6 cylinder block 8 crankshaft 10 first camshaft for intake 12 second camshaft for exhaust 14 crank sprocket 16 first cam sprocket 18 second cam sprocket 20 timing chain 26 tensioner 28 adjuster 30 tension adjustment Means 32 Tensioner arm 34 Fixing bolt 36 Pad 38 Plunger

Claims (1)

[Claims] 1. A chain for winding a crank sprocket mounted on a crankshaft of an internal combustion engine and a cam sprocket mounted on a camshaft, and a tensioner is pressed on the chain by an adjuster to apply an appropriate tension to the chain. In a chain tensioner device for an internal combustion engine to be provided, a tensioner is mounted outside the chain.
Check the load direction on the cylinder head inside the chain.
The adjuster is directed from the loose side of the
And connect the adjuster and the tensioner.
So that the tensioner arm covers a part of the adjuster
Formed into a curved shape with a C-shaped cross section protruding toward the surface of the internal combustion engine
And attach one end of this tensioner arm to the tensioner.
And the adjuster pad is fixed to the other end.
The tensioner arm is attached to the adjuster via the pad.
Chain tensioner device for an internal combustion engine, characterized in that it is.