JP2885007B2 - Chain tensioner device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hydraulic chain tensioner device.

[0002]

2. Description of the Related Art For example, a chain drive for transmitting the rotational force of an engine crankshaft to a camshaft on a cylinder head is provided with a hydraulic chain tensioner for adjusting the tension of the chain by hydraulic pressure.

[0003] As this kind of chain tensioner device,
Conventionally, for example, there is one shown in FIG.
No. 2043, reference).

The chain tensioner device 1 includes a shoe 2 that slides on a chain (not shown), a cylindrical plunger 4 slidable in the direction in which the chain extends, and a cylinder 6 in which a damping chamber 5 is defined by the plunger 4. When,
An oil passage for feeding lubricating oil to the damping chamber 5 via a check valve (not shown) is provided.

In FIG. 6, reference numeral 10 denotes a stopper pin for holding the plunger 4 retracted into the cylinder 6 when assembling the chain tensioner device 1 to the engine block.

The shoe 2 has a locking hole 20 for engaging the tip of the stopper pin 10.

After the chain tensioner device 1 has been assembled to the engine block, the stopper pin 10 is removed, whereby the plunger 4 is pushed out of the cylinder 6 to press the shoe 2 against the chain.

[0008]

However, at the time of assembling such a conventional chain tensioner device 1, when placing the chain on the shoe 2, it is necessary to pull the chain in a direction away from the shoe 2. Therefore, there is a problem that the work of engaging the shoe 2 with the chain becomes difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to improve the assemblability of a hydraulic chain tensioner device.

[0010]

According to the first aspect of the present invention,
The shoe includes a shoe that slides on the chain, a plunger slidable in the chain tension direction, means for urging the plunger in the chain tension direction during operation, and a stopper pin that locks the plunger in a retracted state during assembly. In the chain tensioner device, a guide is provided on the head of the stopper pin, and a slope surface for guiding the shoe on the shoe while sliding the chain when assembling the guide is formed.

[0011]

When the chain tensioner device is assembled to the engine block, the plunger is held in the retracted state via the stopper pin.

Since the stopper pin is provided with a guide having a slope surface inclined alongside the shoe, the chain can be guided on the shoe while sliding on the slope surface of the guide at the time of the assembling. The work of assembling the chain tensioner device can be easily performed without pulling the chain away from the shoe.

After assembling the chain tensioner device,
The stopper pin is removed. When the chain tensioner device is operated, the plunger is pushed out of the cylinder by a biasing means such as a spring, and applies tension to the chain via the shoe.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a chain tensioner device provided in an automobile engine will be described below with reference to the accompanying drawings.

As shown in FIG. 4, an intake cam sprocket 33 connected to an intake camshaft and an exhaust cam sprocket 34 connected to an exhaust camshaft are provided at the front of the left bank of the V-type engine. Crank sprocket and intake cam sprocket connected to shaft 3
2, the chain 17 is wound around the intake cam sprocket 33 and the exhaust cam sprocket 34, and the torque of the crankshaft is transmitted to each camshaft. A chain tensioner 1 that adjusts the tension of the chain 17 by hydraulic pressure is provided between the sprockets 33 and 34.

As shown in FIG. 5, the chain tensioner device 1 includes a shoe 2 which is in sliding contact with a chain 17, a body 3 which is fixed to the engine block 30, and a sliding direction of the chain 17 with respect to the body 3. A possible cylindrical plunger 4 is provided.

As means for urging the plunger 4 in the tensioning direction of the chain 17, a cylinder 6 for slidably fitting the plunger 4, a spring 8 interposed between the plunger 4 and the cylinder 6, a plunger 4 A damping chamber 5 is defined between the cylinder 6 and the cylinder 6, and a reservoir chamber 9 that guides hydraulic pressure to the damping chamber 5 via a check valve 7.

The body 3 has its joint surface 19 joined to the engine block 30 and is fastened through a plurality of bolts. Lubricating oil discharged from the oil pump is pressure-fed to the reservoir chamber 9 from an oil passage formed in the engine block 30.

An oil hole 11 opening into the reservoir chamber 9 is formed in the body 3, and a plug 13 having an oil hole 12 communicating with the oil hole 11 is press-fitted. The check valve 7 is seated at the opening of the oil hole 12 with respect to the damping chamber 9 by the urging force of the spring. Check valve 7 is in damping chamber 5
When the pressure of the reservoir chamber 9 becomes lower than the pressure of the reservoir chamber 9, the valve is opened, and the lubricating oil of the reservoir chamber 9 flows into the damping chamber 5 through the oil holes 11 and 12, while the pressure of the damping chamber 5 is higher than the pressure of the reservoir chamber 9. When this happens, the valve closes.

A plug 25 is press-fitted into the plunger 4, and a leak-down orifice 2 is
6 is spirally carved. The air that has entered the damping chamber 5 is discharged to the chain chamber 35 through the leak down orifice 26.

In FIG. 1, reference numeral 10 denotes a stopper pin for holding the plunger 4 retracted into the cylinder 6 when assembling the chain tensioner device 1 to the engine block 30.

A hole 14 for inserting the stopper pin 10 is formed in the body 3, while a locking groove 15 for engaging the tip of the stopper pin 10 is formed in the plunger 4 in an annular shape over the entire circumference. .

When the chain tensioner device 1 with the stopper pin 10 removed is operated, the locking groove 15 is disposed so as to face the opening edge 16 of the cylinder 6, while the opening edge 16 of the cylinder 6 is tapered. The lubricating oil scattered to the chain chamber 35 is formed by expanding the diameter of the plunger 4 and the body 3.
After being attached to the like, it is collected in the locking groove 15 and is supplied from the locking groove 15 to the sliding portion of the cylinder 6 and the plunger 4.

The gist of the present invention is that a guide 21 is provided on the head of the stopper pin 10 and the guide 2 is provided.
Reference numeral 1 denotes a slope surface 22 for guiding the chain 17 onto the shoe 2 while sliding the chain 17 when the chain tensioner device 1 is assembled.

The guide 21 has a slope surface 22 inclined at a predetermined angle with respect to the sliding direction of the plunger 4, and
2 is formed in a wedge shape so that one end 23 is arranged at the same height as the shoe 2.

The configuration is as described above. Next, the operation will be described.

When the chain tensioner device 1 is assembled to the engine block 30, the stopper pin 10 is inserted through the hole 14 of the body 3 and the plunger 4 is inserted, as shown in FIG.
The plunger 4 is held in a state where the plunger 4 is retracted into the cylinder 6 by engaging with the locking groove 15.

Since the stopper pin 10 is provided with the guide 21 having the slope surface 22 inclined alongside the shoe 2, the chain 17 slides on the slope surface 22 of the guide 21 and is , And the assembling work of the chain tensioner device 1 can be easily performed without pulling the chain 17 away from the shoe 2.

After assembling the chain tensioner device 1, the stopper pin 10 is removed as shown in FIG.

During operation of the engine, the lubricating oil discharged from the oil pump is pressure-fed to the reservoir chamber 9 and supplied from the reservoir chamber 9 to the damping chamber 5 through the oil holes 11 and 12, and the plunger 4 is moved to the damping chamber 5. The lubricating oil pressure and the urging force of the spring 8 push the cylinder 17 out of the cylinder 6 to apply tension to the chain 17 via the shoe 2.

[0031]

As described above, according to the present invention, there are provided a shoe which comes into sliding contact with a chain, a plunger which is slidable in the direction in which the chain is tensioned, and means for urging the plunger in the direction in which the chain is tensioned during operation A stopper pin that locks the plunger in a retracted state when a guide is provided on the head of the stopper pin, and a slope surface that guides onto a shoe while sliding the chain when assembling the guide is provided. Because it is formed, the chain can be guided on the shoe while sliding on the slope surface of the guide at the time of assembly, and the assembly work can be easily performed without pulling the chain in the direction away from the shoe, Improve productivity and maintainability.

[Brief description of the drawings]

FIG. 1 is a side view of a chain tensioner device according to an embodiment of the present invention.

FIG. 2 is a perspective view of the chain tensioner device at the time of assembly.

FIG. 3 is a perspective view of the chain tensioner device after the assembly.

FIG. 4 is a partial front view of the engine.

FIG. 5 is a sectional view of the chain tensioner device.

FIG. 6 is a cross-sectional view of a conventional chain tensioner device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chain tensioner device 2 Shoe 4 Plunger 5 Damping chamber 6 Cylinder 8 Spring 10 Stopper pin 15 Locking groove 17 Chain 21 Guide 22 Slope surface

Claims (1)

(57) [Claims] 1. A shoe slidingly contacting a chain, a plunger slidable in a tension direction of the chain, means for urging the plunger in a tension direction of the chain during operation, and locking the plunger in a retracted state during assembly. A chain tensioner device comprising: a guide pin provided on the head of the stopper pin; and a slope surface for guiding the shoe on a shoe while sliding the chain when assembling the guide. apparatus.