JP5614546B2 - Roller chain - Google Patents

Description

  The present invention relates to a roller chain for transmitting power, and more particularly to a roller chain with improved lubricating oil retention performance.

This type of roller chain is used in various fields for power transmission. For example, a roller chain for driving a cam of an engine described in Patent Document 1 can be given. The roller chain described in Patent Document 1, the outer plate pairs consisting of a pair of outer plates facing each other with a predetermined distance, and the inner chromatography plates also made of a pair of inner plates facing each other with a predetermined distance The pairs are alternately arranged so as to overlap each other in the longitudinal direction.

  At the overlapping portion of the adjacent outer plate pair and inner plate pair, both ends of the bush are fixed to the opposing inner plates, and both ends of the roller pins inserted into the bush are fixed to both outer plates, respectively. . As a result, each pair of plates is connected so as to be able to be bent via the bush and the roller pin, thereby forming an annular roller chain as a whole. Each bush supports a roller rotatably between both inner plates, and these rollers mesh with a sprocket to enable power transmission.

  The roller chain is stretched between the sprocket of the crankshaft of the engine and the sprocket of the intake / exhaust camshaft. The roller is meshed with each sprocket to drive the intake / exhaust camshaft in synchronization with the rotation of the crankshaft. . The roller chain is guided by a chain guide while being tensioned by a tensioner and travels on a predetermined path, and is lubricated by supplying lubricating oil from an oil jet disposed on one side of the travel path.

  Lubricating oil supplied from the oil jet is held between the rollers of the roller chain, and is sequentially used for lubrication while the roller chain is traveling. In Patent Document 1, oil grooves are formed on the opposing surfaces of the outer plate and the inner plate so as to connect the bushes, and the lubricating oil between the rollers is guided between the bushes and the roller pins through these oil grooves. Used for lubrication.

JP 2003-294089 A

  As described above, in the roller chain described in Patent Document 1, with the knowledge that the lubrication between the bush and the roller pin is insufficient, the lubricating oil held between the rollers passes through the oil groove. Leads between bush and roller pin. However, since the bushes are originally close to each roller, the lubricating oil naturally flows to the bush side even if there is no oil groove, and it is difficult to say that it is a very useful measure.

  Rather, it is between the roller chain and the chain guide or tensioner that it is prone to lack of lubrication, which is a fundamental problem caused by supplying the lubricant at one point (oil jet position) in the chain travel path. ing. That is, as described above, the lubricating oil supplied from the oil jet is held between the rollers of the roller chain, and is sequentially provided for lubrication between the roller and the sprocket while the chain is running. This lubrication is performed with lubricating oil that gradually leaks from between the rollers to the outer periphery of the chain.

  However, the roller chain consists essentially of a configuration necessary for the intended power transmission, and no positive measures are taken to keep the lubricating oil between the rollers. For this reason, the lubricating oil between the rollers immediately after being supplied from the oil jet leaks to the outer peripheral side of the chain, and the lubricating oil between the rollers decreases before reaching the position of the oil jet again through a predetermined path. . Therefore, there is a problem that the lubricating oil tends to be insufficient, particularly at a position immediately before the oil jet, and the lubrication performance is liable to deteriorate, and the wear of the roller chain or the chain guide or the tensioner is promoted.

  The present invention has been made to solve such problems, and the object of the present invention is to provide insufficient lubrication between a roller chain and a member such as a chain guide or tensioner in all regions on the chain travel path. It is an object of the present invention to provide a roller chain that can prevent wear and promote wear due to insufficient lubrication.

In order to achieve the above object, the invention of claim 1 is directed to an outer plate pair consisting of a pair of outer plates facing each other at a predetermined interval in the width direction, and a predetermined interval in the width direction inside the outer plates. a pair of inner over plate pairs consisting of an inner plate facing each other have to arrayed alternately to overlap each other in the longitudinal direction, at a location overlapping with the adjacent outer plate pair and the inner plate pair between the inner plate opposing Each roller that can mesh with the sprocket is disposed and supported rotatably by the roller pin, and both ends of each roller pin are respectively penetrated through the inner plate and the outer plate to connect each plate pair so as to form an annular shape as a whole, Power transmission while being lubricated by the lubricating oil supplied from the oil supply means In the la chain, at least one inner plate of the inner plate pair extends toward the other side of the inner plate pair and closes a part of the gap formed between the rollers to reduce the opening area of the gap. Protrusions are provided.

According to a second aspect of the present invention, the closing protrusion is offset on the outer peripheral side of the chain with respect to the center line of the inner plate connecting the roller pins so as to prevent interference with the sprocket teeth.
According to a third aspect of the present invention, the closing projection has a holding surface facing in the chain traveling direction on at least one side of the inner circumferential side of the chain.

In the invention of claim 4, the closing projection has a cross-sectional shape that becomes concave toward the inner peripheral side of the chain.
According to the invention of claim 5, the closing projection is formed by bending one side of the inner plate made of a metal plate, and is located on the inner peripheral side with respect to the edge portion on the outer peripheral side of the chain of the inner plate. .

According to the roller chain of the invention of claim 1 as described above, a pair of outer plates the outer plate pair consisting of a set arrayed and inner chromatography plate pairs consisting of inner plates alternately to roller pin each plate Thus, a closing projection for reducing the opening area of the gap between the rollers is provided on the opposing surface of at least one inner plate of the inner plate pair.

  The roller chain travels on a predetermined path by a guide such as a chain guide or a tensioner to transmit power, and lubrication oil is supplied from an oil supply means arranged on one side of the travel path so that the roller chain and the chain guide Lubricating between the tensioner. The supplied lubricating oil gradually leaks from the gaps between the rollers to the outer periphery of the chain and is used for lubrication. However, in the present invention, the opening area of the gaps between the rollers is reduced by the closing protrusions. Abrupt lubricating oil leaks from are prevented. Therefore, it is possible to continue lubricating by continuously leaking the lubricating oil from the gaps between the rollers until the position of the oil supply means is reached again, so that the roller chain is insufficiently lubricated in all regions on the chain traveling path, and thus wear due to insufficient lubrication. Can be prevented in advance.

According to the roller chain of the second aspect of the invention, since the closing protrusion is offset from the center line of the inner plate on the outer periphery side of the inner plate, interference between the closing protrusion and the sprocket teeth can be prevented in advance. .
According to the roller chain of the invention of claim 3, the holding surface facing the chain running direction is provided on at least one side of the closing protrusion on the inner circumferential side of the chain. The lubricating oil held between the rollers is transferred along with the roller chain while receiving a force in the chain running direction. The force at this time is effectively transmitted to the lubricating oil by the holding surface. On the other hand, the situation in which the lubricant is left behind and leaks between the rollers can be prevented more reliably.

According to the roller chain of the fourth aspect of the present invention, the closing protrusion has a concave cross section toward the inner circumferential side of the chain. For example, the centrifugal force acts on the roller chain in the sprocket outer peripheral region of the chain travel path, so that the lubricating oil held between the rollers is likely to leak to the outer peripheral side of the chain, but the lubricating oil suddenly leaks due to the closed projection on the concave cross section. Can be prevented.
According to the roller chain of the fifth aspect of the present invention, the closing protrusion is formed by bending one side of the inner plate made of a metal plate, and is positioned on the inner peripheral side with respect to the edge of the inner plate on the outer peripheral side of the chain. It was. Therefore, the inner plate with the closing protrusion can be manufactured at a low cost simply by bending the metal plate, and the closing protrusion is located on the inner circumference side of the chain. Wear can be prevented in advance.

It is the front view which looked at the tension state of the timing chain of an embodiment from the engine front. It is an expanded sectional view of the A section of Drawing 1 showing details of a timing chain. FIG. 3 is a view taken in the direction of arrow B in FIG. It is a figure which shows the inner plate seen from the direction corresponding to FIG. It is a figure which shows the inner plate seen from the direction corresponding to FIG. It is a figure which shows another example of the inner plate which has arrange | positioned the closing protrusion in the centerline vicinity. It is a figure which shows another example of the inner plate which made the closure protrusion arc-shaped cross section. It is a figure which shows another example of the inner plate which made the closing protrusion the square cross section. It is a figure which shows another example of the inner plate which carried out the inclination arrangement | positioning of the closing protrusion and made it the holding surface. It is a figure which shows another example of the inner plate which used the protrusion wall formed in the back side of the closing protrusion as the holding surface. It is a figure which shows another example of the inner plate which formed the closure protrusion by bending formation. It is a figure which shows the raw material of the inner plate before bending formation.

Hereinafter, an embodiment in which the present invention is embodied in a timing chain for driving an engine cam will be described.
FIG. 1 is a front view of the timing chain of this embodiment as viewed from the front of the engine.
A drive sprocket 2 fixed to the front end of the crankshaft 1 is disposed in the lower part of the engine, and an intake sprocket 4 fixed to the front end of the intake camshaft 3 and a front end of the exhaust camshaft 5 are fixed to the upper part of the engine. An exhaust sprocket 6 is provided. A timing chain 7 is stretched between these sprockets 2, 4, 6, a tensioner 8 is disposed on the left side of the timing chain 7, and a chain guide 9 is disposed on the right side. The tensioner 8 includes a tensioner lever 8b that is supported by a support shaft 8a so that the upper end of the tensioner 8 can swing and extends in the vertical direction along the timing chain 7, and a hydraulic unit 8c that urges the tensioner lever 8b toward the chain. Has been. The chain guide 9 has a shape extending in the vertical direction along the timing chain 7.

  As shown by the arrows in FIG. 1, during operation of the engine, the drive sprocket 2 rotates together with the crankshaft 1, and accordingly, the timing chain 7 is guided by the chain guide 9 while being tensioned by the tensioner 8, and is predetermined. Drive clockwise on the route. The rotation of the drive sprocket 2 is transmitted to the intake / exhaust sprockets 4 and 6 via the timing chain 7, whereby the intake / exhaust camshafts 3 and 5 are rotationally driven in synchronism with the rotation of the crankshaft 1 to operate the valve mechanism. By this, the engine is operated.

  An oil jet 10 (oil supply means) is disposed below the chain guide 9, and lubricating oil (engine oil) is continuously injected from the oil jet 10 toward the timing chain 7 during engine operation. . The timing chain 7 travels upward via the drive sprocket 2 immediately after the lubricating oil is injected from the oil jet 10 and then travels downward via the intake / exhaust sprockets 4 and 6 to reach the position of the oil jet 10 again. Repeat the above cycle.

  2 is an enlarged cross-sectional view of portion A of FIG. 1 showing details of the timing chain 7, FIG. 3 is a view taken along the arrow B of FIG. 2 showing details of the timing chain 7, and FIG. 4 is a view from a direction corresponding to FIG. FIG. 5 is a diagram showing the inner plate viewed from the direction corresponding to FIG. 2. In FIG. 4, members such as roller pins are partially shown together with the inner plate.

As a whole, the timing chain 7 is composed of an outer plate pair composed of a pair of outer plates 13 facing each other at a predetermined interval in the width direction (engine longitudinal direction), and one pair facing each other at a predetermined interval in the width direction. The inner plate pairs of inner plates 14 are alternately arranged in the longitudinal direction.
Outer plate 1 3 and the inner plate 14 is at an oval shape fabricated from respective metal plate. By a set of outer plates 1 3 of both the inner plate 14 of the inner plate pair inside each outer plate pair is positioned, and the outer plate pair and the inner plate pair adjacent the longitudinal direction are arranged to overlap each other ing. At the overlapping portion of the outer plate pair and the inner plate pair, both ends of the bush 15 are caulked and fixed to the inner plate 14 facing each other.

  A roller pin 16 is inserted into each bush 15, and both ends of each roller pin 16 protrude in the width direction from the bush 15 and are fixed by caulking to the opposing outer plates 13. Thereby, each plate pair is connected via the bush 15 and the roller pin 16 so as to be able to be bent, thereby forming a timing chain 7 having an annular shape as a whole. Rollers 17 are rotatably supported between the opposing inner plates 14 on each bush 15, and these rollers 17 mesh with the drive sprocket 2 and intake / exhaust sprockets 4, 6 through the timing chain 7. Power transmission is performed.

  The lubricating oil injected from the oil jet 10 leaks to the outer periphery of the chain while being held between the rollers 17 of the timing chain 7, and between the timing chain 7 and the chain guide 9 and the tensioner 8 located on the outer periphery of the chain travel path. Lubricate. However, as described in [Problems to be Solved by the Invention], the lubricating oil between the rollers 17 suddenly leaks to the outer peripheral side of the chain, and between the rollers 17 until the position of the oil jet 10 is reached again. There is a problem that the lubricating oil leaks out and a sufficient lubricating action cannot be obtained. In comparison with the configuration of the present embodiment, the tensioner 8 positioned immediately after the lubricating oil is injected from the oil jet 10 is lubricated with the timing chain 7 by a large amount of lubricating oil, whereas the tensioner 8 immediately before the oil jet 10 is lubricated. The chain guide 9 located at is insufficiently lubricated and insufficiently lubricated.

Therefore, in the present embodiment, the shape of the inner plate 14 of the timing chain 7 is devised to improve the holding performance of the lubricating oil between the rollers 17 to suppress the sudden leakage of the lubricating oil. The countermeasures will be described in detail.
As shown in FIGS. 2 to 5, closing projections 18 are provided on the opposing surfaces of all the inner plates 14 to the mating side. The closing protrusion 18 is welded to the inner plate 14 at the base end and protrudes toward the inner plate 14 on the other side. Further, the closing protrusion 18 has a square plate shape, is parallel to the center line C (in other words, the chain traveling direction) of the inner plate 14 connecting the roller pins 16, and is chained by a dimension a with respect to the center line C. It arrange | positions so that it may offset to an outer peripheral side. The tips of the closing protrusions 18 of the inner plates 14 facing each other correspond to each other through a slight gap, and a part of the gap between the rollers 17 is closed by these closing protrusions 18, so that the gap extends toward the inner circumference side of the chain. The opening area is reduced. Here, as shown in FIGS. 2 and 3, the closing protrusions 18 provided on each inner plate 14 exist between every other roller 17, and the opening area as described above is between the rollers 17 having the closing protrusions 18. Reduction has been made.

  When the lubricating oil is injected from the oil jet 10 to the timing chain 7, the opening area of the gap between the rollers 17 is reduced between the rollers 17 where the closing protrusions 18 exist, and therefore between the rollers 17 where the closing protrusions 18 do not exist. Compared to the above, the amount of lubricating oil leaked from the gap to the outer periphery of the chain is remarkably reduced. Therefore, when the lubricating oil is injected from the oil jet 10 and the timing chain 7 travels upward through the drive sprocket 2, a sudden leakage of the lubricating oil is prevented between the rollers 17 where the closing projections 18 are present, and thereafter the absorbing oil is absorbed. The lubricating oil continues to be held between the rollers 17 until it travels downward through the exhaust sprockets 4 and 6 and reaches the position of the oil jet 10 again, and the leakage of the lubricating oil to the outer periphery of the chain continues.

  As a result, the amount of lubricating oil leaked in the first half region (including the position of the tensioner 8) of the chain travel path starting from the oil jet 10 that has been in an excessive tendency has been reduced, while the chain travel path has been in a shortage. The amount of leakage of lubricating oil in the latter half region (including the position of the chain guide 9) increases, and the amount of leakage of lubricating oil over the entire chain travel path is made more uniform. For this reason, not only the tensioner 8 that can be sufficiently lubricated in the past but also the chain guide 9 that has been insufficiently lubricated can be sufficiently lubricated, thereby causing troubles such as promoting the wear of the roller chain or the chain guide 9 and the tensioner 8. Can be prevented.

  In addition, in the present embodiment, the closing protrusion 18 is offset on the outer peripheral side of the chain with respect to the center line C of the inner plate 14 connecting the roller pins 16. Therefore, as shown in FIG. 2 in particular, a gap is always formed between the closing projection 18 and the teeth of the sprockets 2, 4, 6. It is possible to prevent troubles such as the generation of abnormal noise when it interferes with the noise.

By the way, the closing protrusion 18 of the present invention is not limited to the configuration described in the above embodiment and can be variously changed. Therefore, another example of the closing protrusion 18 will be described below.
First, in the above embodiment, the closing protrusion 18 is offset from the center line C of the inner plate 14 on the outer peripheral side of the chain. However, it does not necessarily have to be offset if it does not interfere with the teeth of the sprockets 2, 4, and 6. . Therefore, for example, as shown in FIG. 6, the offset dimension a is reduced, and the closing protrusion 18 is disposed near the center line C of the inner plate 14, or the closing protrusion 18 is disposed at a position completely coincident with the center line C. You may do it. In these cases, it is possible to shorten the length of the closing projection 18 required for closing the gap between the rollers 17 in the chain running direction, and as a result, it is possible to suppress an increase in the weight of the timing chain 7 due to the provision of the closing projection 18. The benefits of

  Moreover, in the said embodiment, although the closing protrusion 18 was formed in square plate shape, it does not restrict to this shape. For example, as shown in FIG. 7, the closing projection 18 may be formed in a circular arc shape that is concave toward the inner circumferential side of the chain, or is concave toward the inner circumferential side of the chain as shown in FIG. You may form in a cross-sectional angle | corner shape. For example, in the region corresponding to the sprocket outer periphery of the chain travel path, the centrifugal force acts on the timing chain 7, so that the lubricating oil held between the rollers 17 is more likely to leak to the chain outer peripheral side. Since the lubricating oil is retained in the inside, another advantage that a sudden leakage of the lubricating oil can be prevented more reliably is obtained.

  For example, as shown in FIG. 9, the surface of the closing protrusion 18 on the inner circumferential side of the chain may be used as a holding surface 21, and the closing protrusion 18 may be inclined so that the holding surface 21 faces the chain travel direction. Further, as shown in FIG. 10, a projecting wall 22 is formed on the rear side of the closing projection 18 in the chain traveling direction toward the inner circumferential side of the chain, and the surface of the projecting wall 22 facing the chain traveling direction is the holding surface 22a. It is good.

  The lubricating oil held between the rollers 17 is transferred together with the timing chain 7 while receiving a force in the chain traveling direction, and the force at this time is effectively transmitted to the lubricating oil by the holding surfaces 21 and 22a. For this reason, it is possible to prevent a situation in which the lubricating oil is left with respect to the travel of the timing chain 7, and a situation in which the remaining lubricating oil leaks from between the rollers 17 to the chain outer peripheral side. In the above-described embodiment in which the oil jet 10 is disposed at the lower part of the engine, the timing chain 7 runs upward immediately after the lubricating oil is injected, and gravity acts on the lubricating oil between the rollers 17. In this region that travels upward, prevention of leakage of the lubricating oil is particularly required. However, the above-described leaving of the lubricating oil (the falling of the lubricating oil) is more likely to occur due to gravity. Since the remaining of the lubricating oil due to the gravity is also prevented by the holding surfaces 21 and 22a, the leakage of the lubricating oil from between the rollers 17 can be more reliably prevented.

Moreover, in the said embodiment, although the closing protrusion 18 was welded with respect to the inner plate 14, the formation method of the closing protrusion 18 is not limited to this, It can change variously. For example, the closing protrusion 18 may be formed by bending, or the closing protrusion 18 may be integrally formed with the inner plate 14 by casting.
FIG. 11 shows the inner plate 14 in which the closing protrusion 18 is formed by bending. In the manufacturing process of the inner plate 14, first, a metal plate of a material is stamped and formed into a shape of the inner plate 14 including the closing protrusion 18 shown in FIG. 12, and then the portion of the closing protrusion 18 is bent at a right angle. To do. As shown by a broken line in FIG. 12, the folding line L at this time is set to the inner peripheral side of the chain by the dimension b from the edge of the inner plate 14 on the outer peripheral side of the chain, that is, the sliding contact portion with respect to the chain guide 9 or the tensioner 8. To do. As a result, the closed closing protrusion 18 is positioned on the inner circumference side of the chain by a dimension b from the sliding contact portion. Accordingly, the inner plate 14 provided with the closing protrusion 18 can be manufactured at low cost by simply forming a bent metal plate, and the closing protrusion 18 is located on the inner circumferential side of the chain. There is also an advantage that wear of the closing projection 18 due to the friction can be prevented.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the timing chain 7 for driving the cam of the engine is embodied, but the target roller chain is not limited to this. For example, the present invention may be embodied in a roller chain for driving an oil pump that connects an engine crankshaft 1 and an oil pump shaft.
In the above embodiment, the closing protrusions 18 are provided on all inner plates 14 in the chain longitudinal direction. However, the closing protrusions 18 may be provided only on some inner plates 14, for example, on every other inner plate 14. Good. In addition, although the closing protrusions 18 are provided on the pair of inner plates 14 constituting the inner plate pair, the closing protrusions 18 may be provided only on one of the inner plates 14. In that case, if the closing protrusion 18 is extended toward the opposed inner plates 14, the gap between the rollers 17 can be reduced to an intended opening area.

2 Drive sprocket 4 Intake sprocket 6 Exhaust sprocket 10 Oil jet (oil supply means)
13 Outer plate 14 Inner plate 16 Roller pin 17 Roller 18 Closing protrusion 21, 22a Holding surface C Center line

Claims (5)

The outer plate pair and the inner chromatography plate comprising a pair of inner plates facing each other with a predetermined distance in the width direction inside of the both outer plate of a pair of outer plates facing each other with a predetermined distance in the width direction The pairs are alternately arranged so as to overlap each other in the longitudinal direction, and a roller that can mesh with the sprocket is disposed between the opposing inner plates at the overlapping portion of the adjacent outer plate pair and the inner plate pair. The roller pins are rotatably supported, and both ends of each roller pin are passed through the inner plate and the outer plate, respectively, so that the plate pairs are connected to form an annular shape as a whole, and supplied from the oil supply means. For roller chains that transmit power while being lubricated with lubricating oil Stomach,
Closure that extends toward at least one of the inner plate pairs toward the other side of the inner plate pair and closes a part of the gap formed between the rollers to reduce the opening area of the gap. A roller chain characterized by providing protrusions.   2. The roller according to claim 1, wherein the closing protrusion is offset on the outer peripheral side of the chain with respect to the center line of the inner plate that connects the roller pins so as to prevent interference with the teeth of the sprocket. chain.   3. The roller chain according to claim 1, wherein the closing protrusion has a holding surface facing in the chain traveling direction on at least one side of the inner circumferential side of the chain.   4. The roller chain according to claim 1, wherein the closing protrusion has a cross-sectional shape that is concave toward the inner peripheral side of the chain.   2. The closing protrusion is formed by bending one side of an inner plate made of a metal plate, and is located on an inner peripheral side of an edge portion on the outer peripheral side of the chain of the inner plate. 5. The roller chain according to any one of 4 to 4.

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