JP2003278860A - Tensioner with bar for sensing state of chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tensioner with a bar for sensing a state of a chain which surely sensesing a worn, expanding state of a timing chain without detaching any components built in an engine and considerably reducing a maintenance load for the timing chain. <P>SOLUTION: The tensioner with a bar for sensing the state of a chain is provided with a housing body 110 mounted on a wall E of an engine block, a plunge 120 urging with a spring in an projecting-free state toward the timing chain TC travelling in front of the housing body 110, and a sensing bar for the state of a chain projecting to outside the engine from a back side of the housing body 110 integrally provided with the plunger 120. Thus, the worn, expanding state of the timing chain is surely sensed from the outside of the tensioner. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tensioner used to apply proper tension to a timing chain that is wound around a crankshaft side sprocket and a camshaft side sprocket of a vehicle engine, and more particularly, The present invention relates to a tensioner capable of detecting wear elongation of a timing chain from outside the engine.

[0002]

2. Description of the Related Art Tensioners are widely used to suppress vibrations generated in a timing chain of a vehicle engine during traveling and to maintain proper tension. In such a tensioner, the plunger protruding from the housing body presses the back surface near the swing end of the tensioner lever that is swingably supported on the engine body side, so that the shoe surface of the tensioner lever is chained. It is configured to be in sliding contact with the slack side to apply tension.

[0003]

However, in the conventional tensioner as described above, it is possible to apply tension to the timing chain that is wound around the inside of the engine, but the wear elongation of this timing chain is applied from outside the engine. It could not be detected. That is, there is an unreasonable problem that even a timing chain in which wear elongation does not occur must be replaced for safety in legal inspection of the vehicle after a certain period of time, regular inspection, etc. Conversely, even with a timing chain that needs to be replaced soon after wear elongation begins to occur, it is not possible to reliably detect the extent of wear, which causes a serious inspection problem of missing the original replacement time. there were. For this reason, in order to detect the wear elongation of the timing chain with the conventional tensioner, it is necessary to remove the engine case and check how much the plunger of the tensioner has advanced, which is a troublesome and troublesome problem.

Further, in a direct-injection gasoline engine or a diesel engine of a type in which fuel is directly injected into a cylinder of an engine, a half-burn phenomenon in which flame propagation is interrupted during combustion, incomplete diffusion of fuel, etc. occur, and burning residue is generated. The soot (carbon soot) is likely to occur, and a large amount of such soot is mixed into the engine oil to induce oil deterioration. This oil deterioration significantly wears the timing chain that meshes with the sprocket, resulting in chain wear elongation. Since it occurs, there is an urgent problem that the above-mentioned problems should be given more importance.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to secure the wear elongation of the timing chain from the outside without removing any parts incorporated in the engine. It is to provide a tensioner with a chain state detection bar that can detect the above and can remarkably reduce the maintenance load of the timing chain.

[0006]

A tensioner with a chain condition detecting bar according to the present invention according to claim 1 can freely project toward a housing body mounted on an engine and a timing chain running in front of the housing body. In order to solve the above-mentioned problems, a plunger that is biased by a spring and a chain state detection bar that is provided integrally with the plunger and that projects from the rear part of the housing body toward the outside of the engine are provided. is there.

In the tensioner with a chain condition detecting bar according to a second aspect of the present invention, in addition to the structure described in the first aspect, a chain extension conversion scale is engraved on the protruding portion of the chain condition detecting bar. This further solves the above-mentioned problems.

The plunger in the tensioner with a chain state detecting bar of the present invention may be any one as long as it is biased by a spring so as to project from the front of the housing body toward the traveling timing chain, but hydraulic pressure is added. It may be biased by a spring.

The tensioner with a chain condition detecting bar according to the present invention is provided integrally with the plunger to ensure the wear elongation of the timing chain from the outside by the chain condition detecting bar protruding from the rear portion of the housing body toward the outside of the engine. As long as it can be detected, it may be either a tensioner that is hermetically mounted inside the engine, which is called an internal type, or a tensioner that is inserted and mounted from the outside, which is called an exterior type.

[0010]

According to the tensioner with a chain state detecting bar of the present invention, the housing body mounted on the engine, the plunger biased by the spring so as to project toward the timing chain traveling in front of the housing body, and A timing chain that is provided integrally with the plunger and has a chain state detection bar that protrudes from the rear part of the housing body toward the outside of the engine, and that is hung between the crankshaft side sprocket and the camshaft side sprocket. If wear elongation occurs when the engine is driven, the plunger protrudes from the housing body to the timing chain side in order to eliminate the decrease in chain tension due to this wear extension, and applies proper chain tension to the timing chain.

At this time, since the chain condition detecting bar provided integrally with the plunger is pulled in to the timing chain together with the plunger, the protruding amount of the chain condition detecting bar protruding from the rear portion of the housing body toward the outside of the engine. Changes. In this way
The wear elongation of the timing chain becomes visible from the outside.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of a preferred embodiment of a tensioner with a chain state detecting bar of the present invention (hereinafter, simply referred to as "tensioner") will be described with reference to the drawings. First, the tensioner 100 which is the first embodiment of the present invention will be described. 1 is an installation view of a tensioner that is a first embodiment of the present invention, FIG. 2 is a sectional view of the tensioner shown in FIG. 1, and FIG.
It is a principal part perspective view of the plunger shown in FIG.

The tensioner 100 of the present embodiment is a crankshaft side sprocket S in a motorcycle engine that does not require a hydraulic supply pump as shown in FIG.
1 was used as an external tensioner inserted and mounted from the outside of the engine in order to suppress the vibration generated during traveling of the timing chain TC hung between the camshaft side sprocket S2 and the camshaft side sprocket S2, and to maintain an appropriate tension. A timing chain TC that travels in front of the housing body 110 mounted on the engine block wall E.
A bottomed cylindrical plunger 120 that projects toward and is biased by a spring presses the back surface near the swing end of a tensioner lever TL pivotally supported by the engine block wall E so that the tensioner lever TL can swing. The shoe surface of the TL slidingly contacts the slack side of the timing chain TC to apply tension. Note that reference numeral TG in FIG.
Is a tensioner guide which is fixed to the engine block wall E and guides the timing chain TC so as not to shake laterally.

Now, the structure of the tensioner 100 of the present embodiment will be described in detail. As shown in FIGS. 2 to 3, the plunger 120 projects from the rear portion of the housing body 110 toward the outside of the engine. The chain state detection bar 130 is provided. That is, the chain state detecting bar 130 is integrally provided by being inserted into the inner cylindrical portion of the bottomed cylindrical plunger 120 and being screwed and fixed to the inner bottom of the plunger 120. And
A chain extension conversion scale 131 capable of quantitatively converting the chain extension generated inside the engine and detecting it outside the engine is engraved on the protruding portion of the chain state detection bar 130. 131 can be appropriately set according to various conditions such as the type of timing chain to be used and the installation status.

Reference numeral 140 in FIG. 2 is a plunger spring for urging the plunger 120 so as to project toward the tensioner lever TL, and reference numeral 150.
Is the lubricating oil for sliding the plunger 120 smoothly and the housing body 110 and the chain state detecting bar 130.
It is an O-ring that prevents leakage from between.

In the thus obtained tensioner 100 of this embodiment, when the timing chain TC, which is wound between the crankshaft side sprocket S1 and the camshaft side sprocket S2, is worn and stretched when the engine is driven, The plunger 120 tries to eliminate the decrease in the chain tension due to the wear elongation, and the housing main body 11
It projects from 0 to the timing chain TC side, and applies proper chain tension to the timing chain TC.

At this time, since the chain state detection bar 130 provided integrally with the plunger 120 is pulled into the timing chain TC side together with the plunger 120, the chain state protruding from the rear portion of the housing body 110 toward the outside of the engine. The protrusion amount of the detection bar 130 changes. Therefore, the wear elongation of the timing chain TC can be reliably detected from the outside without removing any parts incorporated in the engine, and the maintenance load of the timing chain TC can be significantly reduced.

Next, a tensioner 200 which is a second embodiment of the present invention will be described with reference to FIGS. However, since the tensioner 200 of the present embodiment is an exterior type that is basically inserted and mounted from the outside of the engine similar to the tensioner structure of the first embodiment described above, members having the same structure, action, and effect will be described. Description thereof will be omitted by giving corresponding reference numerals.

The most characteristic structure of the tensioner 200 of this embodiment is, as shown in FIGS. 4 to 5, that the plunger 220 has a chain state detecting bar 230 protruding from the rear portion of the housing body 210 toward the outside of the engine. Be prepared. That is, the chain state detecting bar 230 is configured such that the rear end portion of the plunger 220 is partially extended. The configuration other than this is the same as that of the first embodiment, and the same effects are achieved.

Further, a tensioner 300 which is a third embodiment of the present invention will be described with reference to FIG. However,
The tensioner 300 of the present embodiment is an exterior type that is basically inserted and mounted from the outside of the engine similar to the tensioner structure of the first embodiment described above, and therefore, members having the same structure, action, and effect are compatible. The description is omitted by attaching the reference numerals.

Therefore, the most characteristic structure of the tensioner 300 of this embodiment is, as shown in FIG. 6, a ratchet pawl 311 pivotally supported by a housing body 310.
Ratchet locking mechanism 3 in which is engaged with ratchet teeth 321 engraved on one outer peripheral surface of the plunger 320.
60, and the ratchet locking mechanism 360 prevents the plunger 320 from returning due to abnormal tension in the timing chain TC generated when the engine is driven.
Basically, the same operational effects as those of the first embodiment described above are obtained.

Further, a tensioner 400 which is a fourth embodiment of the present invention will be described with reference to FIG. However,
The tensioner 400 of the present embodiment is an exterior type that is basically inserted and mounted from the outside of the engine similar to the tensioner structure of the second embodiment described above, and therefore, members having the same structure, action, and effect are compatible. The description is omitted by attaching the reference numerals.

Ratchet type hydraulic tensioner 4 of this embodiment
The most characteristic structure of 00 is to supply the supplied oil to the plunger receiving hole 411 and the plunger 420 as shown in FIG.
And a hydraulic valve mechanism 470 for preventing the reverse flow of the high pressure oil chamber 412 formed between
The hydraulic valve mechanism 470 prevents the timing chain TC generated when the engine is driven from returning to the plunger 420 due to abnormal tension, but basically the same operational effect as that of the second embodiment described above is achieved. Note that reference numeral 471 in FIG. 7 is a ball seat, and reference numeral 472.
Is a check ball, reference numeral 473 is a retainer, and reference numeral 474 is an oil supply hole communicating with an external oil supply source (not shown).

A tensioner 500 according to the fifth embodiment of the present invention will be described with reference to FIGS. 8 to 9. As shown in FIG. 8, the tensioner 500 of the present embodiment suppresses the vibration generated when the timing chain TC, which is a silent chain wound between the crankshaft side sprocket S1 and the camshaft side sprocket S2 of the engine, travels. In addition, in order to maintain proper tension, the timing chain TC is used as an internal tensioner that is hermetically mounted inside the engine and that travels in front of the housing body 510 mounted on the engine block wall E. A bottomed cylindrical plunger 520, which projects toward the spring and is biased by a spring, presses the back surface near the swing end of the tensioner lever TL pivotally supported by the engine block wall E so that the tensioner lever TL is supported. The shoe surface slides into contact with the slack side of the timing chain TC to add tension. It has become to so that. Reference numeral TG in FIG. 8 is a tensioner guide that is fixed to the engine block wall E and guides the timing chain TC so as not to shake laterally.

Now, the structure of the tensioner 500 of this embodiment, which is most characterized, will be described in detail. As shown in FIG. 9, the plunger 520 has a housing body 51.
The chain state detection bar 530 is provided so as to project from the rear portion of 0 toward the outside of the engine. That is, the chain state detection bar 530 is the bottomed cylindrical plunger 52.
It is inserted into the inner cylindrical portion of No. 0, is screwed and fixed to the inner bottom of the plunger 520, and is integrally provided. The chain extension conversion scale 531 is engraved on the protruding portion of the chain state detection bar 530.

Reference numeral 540 in FIG. 9 is a plunger spring for urging the plunger 520 to project toward the tensioner lever TL, and reference numeral 550 is a housing for the lubricating oil for sliding the plunger 520 smoothly. An O-ring for preventing leakage from between the main body 510 and the chain state detection bar 530, reference numeral 560 is
This is an O-ring that prevents engine oil floating in the engine from leaking between the engine block wall E and the chain state detection bar 530.

The tensioner 500 of the present embodiment thus obtained is the same as that of the external tensioner of the first embodiment described above except that the method of attachment to the engine is different. It is possible to obtain substantially the same operational effects as the exterior tensioner of the first embodiment.

Further, a tensioner 600 which is a sixth embodiment of the present invention will be described with reference to FIG. However, since the tensioner 600 of the present embodiment is an internal type that is hermetically mounted inside the engine, which is basically the same as the tensioner structure of the fifth embodiment described above, it has the same structure / operation / operation.
The members having the effect are denoted by the corresponding reference numerals, and the description thereof will be omitted.

Therefore, the most characteristic structure of the tensioner 600 of this embodiment is, as shown in FIG. 10, a ratchet pawl 61 that is pivotally supported by a housing body 610.
1 is provided with a ratchet locking mechanism 660 adapted to mesh with ratchet teeth 621 engraved on one side of the outer periphery of the plunger 620, and the ratchet locking mechanism 660 causes the plunger 620 due to abnormal tension to the timing chain TC generated when the engine is driven. However, basically the same operational effect as that of the fifth embodiment described above is obtained.

The tensioner of each of the above-described embodiments of the present invention has been described with reference to the timing chain TC which is wound around the crankshaft side sprocket S1 and the camshaft side sprocket S2 of the engine.
It is needless to say that the present invention is applicable even to a timing belt that is wound around the crankshaft side sprocket S1 and the camshaft side sprocket S2 of the engine.

[0031]

The tensioner with a chain state detecting bar of the present invention comprises a housing body mounted on an engine, a plunger biased by a spring so as to project toward a timing chain traveling in front of the housing body, and By providing the chain state detection bar which is provided integrally with the plunger and protrudes from the rear portion of the housing body toward the outside of the engine, the following effects peculiar to the present invention are achieved.

According to the tensioner with the chain condition detecting bar of the first aspect, when the timing chain is worn and stretched when the engine is driven, the plunger protrudes from the housing body to the timing chain side to provide proper chain tension. In addition, the protrusion amount of the chain state detection bar protruding from the rear part of the housing main body to the outside of the engine changes, so that the wear elongation of the timing chain can be changed from the outside without removing any parts incorporated in the engine. It can be reliably detected, and the maintenance load of the timing chain in legal inspection and regular inspection of the vehicle can be significantly reduced.

According to the tensioner with a chain condition detecting bar of the present invention, in addition to the effect of the invention of claim 1, a chain extension conversion scale is engraved on the protruding portion of the chain condition detecting bar. As a result, the wear elongation of the timing chain can be quantitatively detected from the outside, so that the proper replacement timing of the timing chain can be grasped in advance.

In particular, when the tensioner with a chain condition detecting bar of the present invention is used in a direct injection type gasoline engine or a diesel engine, it is possible to reliably detect wear elongation which tends to occur in a timing chain due to oil deterioration due to soot. Because it is possible, abnormal growth of the timing chain in direct injection gasoline engine and diesel engine,
It is possible to effectively carry out maintenance such as chain replacement.

[Brief description of drawings]

FIG. 1 is an installation view of a tensioner with a chain condition detecting bar according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the tensioner shown in FIG.

FIG. 3 is a perspective view of a main part of the plunger shown in FIG.

FIG. 4 is a sectional view of a tensioner with a chain state detecting bar, which is a second embodiment of the present invention, for mounting.

5 is a perspective view of an essential part of the plunger shown in FIG.

FIG. 6 is a sectional view of a tensioner with a chain state detecting bar according to a third embodiment of the present invention, showing the attachment thereof.

FIG. 7 is a mounting sectional view of a tensioner with a chain condition detecting bar according to a fourth embodiment of the present invention.

FIG. 8 is an installation view of a tensioner with a chain condition detecting bar according to a fifth embodiment of the present invention.

9 is a sectional view of the tensioner shown in FIG.

FIG. 10 is a sectional view of a tensioner with a chain condition detecting bar according to a sixth embodiment of the present invention, showing the attachment thereof.

[Explanation of symbols]

100, 200, 300, 400, 500, 600
..Tensioners 110, 210, 310, 410, 510, 610.
..Tensioner main body 311,611 ... Ratchet pawl 412 ... High pressure oil chamber 120,220,320,420,520,620
..Plunger 321,621 ... Ratchet teeth 130,230,330,430,530,630
..Chain state detection bars 131, 231, 331, 431, 531, 631.
..Chain elongation conversion scale 140,240,340,440,540,640
..Plunger springs 150, 250, 350, 450, 550, 650
..O-rings 360, 660..ratchet locking mechanism 470..hydraulic valve mechanism 471..ball seat 472..check ball 473..retainer 474..oil supply hole S1 .. Shaft side sprocket S2 ・ ・ ・ Driven shaft side sprocket TC ・ ・ ・ Timing chain TG ・ ・ ・ Tensioner guide TL ・ ・ ・ Tensioner lever E ・ ・ ・ Engine block wall

Claims (2)

[Claims] 1. A housing body mounted on an engine, a plunger biased by a spring so as to project toward a timing chain traveling in front of the housing body, and a rear portion of the housing body integrally provided with the plunger. A tensioner with a chain condition detection bar, which is equipped with a chain condition detection bar protruding from the outside of the engine. 2. The chain condition detecting bar tensioner according to claim 1, wherein a chain extension conversion scale is engraved on a protruding portion of the chain condition detecting bar.