JPH0156304B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a silent chain, and more particularly, when the link plate is engaged with a sprocket, the inner flanks of the teeth of the link plate come into contact with the teeth of the sprocket, and then the inner flanks of the teeth of the link plate are different from the teeth of the sprocket. This invention relates to a silent chain in which impact and noise during meshing are reduced by making the outer flanks of the teeth of other link plates mesh with the teeth of the sprocket.

(b) Prior art Silent chains that are generally known in the past include one in which the outer flank of the link plate contacts the teeth of the sprocket when it engages with the sprocket, and one in which the inner flank of the link plate contacts the teeth of the sprocket. There is. Of these, in the former type, as shown in Fig. 5, when the silent chain is stretched out almost in a straight line and wrapped around the sprocket, one link plate _a2 constituting the silent chain lies on the engagement pitch line. When the outer flank C of a pair of teeth B ₂ of the other link plate A ₁ overlaps with that tooth, the inner flank d of the tooth B ₁ of A ₁ is made to protrude outward from ₁ , and when it engages with the sprocket. As shown in FIG. 6, the outer flank on the rear side in the direction of travel contacts the tooth t of the sprocket s,
When the silent chain is completely wrapped around the sprocket, the outer flank on the front side in the direction of movement also comes into contact with other teeth of the sprocket to eliminate play between the teeth of the sprocket and the teeth of the link plate. In this type of silent chain, the pitch P′ 1 between the outer flanks on the meshing pitch line of a pair of teeth of one link plate a is equal to the pitch P′ ₁ between the outer flanks on the meshing pitch line of the teeth of the other two link plates that overlap with that tooth. It is always larger than the pitch P′ ₂ between them.

On the other hand, in the latter type, as shown in Fig. 7, when the silent chain is stretched out almost in a straight line and wrapped around the sprocket, one link plate a constituting the silent chain is located on the meshing pitch line. ₁ ' pair of teeth b ₁ ' inner flank d ₁ ' overlaps the other link plate a ₂ ' tooth b ₂ ' outer flank c ₂ ' is made to protrude outward When the silent chain is engaged with the sprocket, the front inner flank in the direction of movement of one link plate comes into contact with the tooth t of the sprocket s, as shown in Fig. 8, and when the silent chain is completely wrapped around the sprocket, The rear inner flank in the direction of movement of the link plate also contacts other teeth of the sprocket to eliminate play between the teeth of the sprocket and the teeth of the link plate. In this type of silent chain, one link plate
The pitch P ₁ ″ between the outer flanks on the meshing pitch line of a pair of teeth a′ is always smaller than the pitch P ₂ ″ between the inner flanks on the meshing pitch line of the teeth of the other two link plates that overlap with that tooth. ing.

In such conventional silent chains, when the silent chain meshes with the sprocket, only the outer flanks or only the inner flanks of the overlapping link plates come into contact with the teeth of the sprocket, causing a large impact to these flanks. The added force not only caused premature wear of the flanks, but also caused harsh noise.

(c) Problem to be solved by the invention The problem to be solved by the invention is that when the silent chain engages with the sprocket, the outer flank of the tooth of one link plate and the tooth of the other link plate that overlaps with the tooth of one link plate. The aim is to prevent wear of the link plate flanks and reduce noise by bringing the inner flanks of the link plate into contact with the same tooth of the sprocket at the same time or at different times.

(d) Means for Solving the Problems In order to solve the above problems, the present invention provides a pair of teeth each defined by an inner flank and an outer flank, and a pair of holes into which the connecting member is inserted. In a silent chain formed by endlessly connecting a plurality of link plates by the connecting member, the shape of the inner flank and the outer flank is such that the pitch between the outer flanks on the pitch line of the paired teeth is P ₁ , P ₂ is the pitch between the inner flanks of the teeth of the other two link plates that mesh with the pair of teeth when the silent chain extends approximately in a straight line, and the inner side when the silent chain is wrapped around the sprocket. When the pitch between flanks is P ₃ , P ₂ > ≒ P ₁ > ≒
It is configured so that P ₃ .

(E) Function The silent chain having the above structure is hung on a pair of sprockets, and power is transmitted between the sprockets. When the silent chain meshes with the sprocket, the outer flanks of the teeth of the link plate and the inner flanks of the teeth of other link plates overlapping the teeth abut the same teeth of the sprocket, either at the same time or at different times.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

1 and 2, a portion of a first embodiment of the silent chain of the present invention is shown. In the figure, 1 is a silent chain, 2 is a silent chain, and 2 is a silent chain.
a link plate having a pair of teeth 3 defined by an outer flank 4 and an inner flank 5;
Reference numeral 7 denotes a connecting member, that is, a connecting pin, which is inserted into the hole 6 of the link plate 2 and rotatably connects the link plates.

This link plate 2 has an outer flank 4 formed in a substantially linear shape and an inner flank 5 formed in an arc shape, so that when the silent chain 1 is extended substantially linearly, the meshing pitch line of the overlapping teeth of adjacent link plates is The inner flank 5 is formed to protrude from the outer flank. That is, P ₁ is the pitch between the outer flanks of a pair of teeth of the link plate 2 on the meshing pitch line, and one link plate 2, 2b when the silent chain is extended almost in a straight line.
Another link plate 2 overlapping the pair of teeth of
The pitch between the inner flanks of teeth 2a and 2c is P ₂ ,
When the silent chain 1 is wrapped around the sprocket 10 to form an arc shape as shown in FIG. 3, the other two link plates (for example, 2e in FIG. 3) overlap with a pair of teeth of one link plate (for example, 2e in FIG. 3). For example, the pitch on the meshing pitch line of teeth 2d and 2f in FIG.
right tooth of e and left tooth of link plate 2d)
When the pitch between the inner flanks on the meshing pitch line is _P3 , the inner flank 5 and the outer flank of each link plate are formed so that _P2 >≒ _P1 > _≈P3 . Here, ≒ means "approximately equal".

The silent chain with the above structure is hooked on the driving sprocket and the driven sprocket and transmits power between them in the same way as a normal silent chain. Different from conventional silent chains.

That is, as shown in FIG. 3, the teeth of the link plate (the teeth on the right side of the link plate 2a and the teeth on the left side of the link plate 2b overlapping with the teeth on the right side in FIG. 3) are aligned with the teeth 11 of the sprocket 10.
When meshing, when P ₂ > ≒ P ₁ > ≒ P ₃ , the inner flank 5 of the right tooth of the link plate 2a first hits on or near the pitch circle r of the teeth of the sprocket 10, and P ₂ ≒ P In the case of ₁ ≒ P ₃ , the inner flank of the right-hand tooth of link plate 2a and the outer flank of the left-hand tooth of link plate 2b, which overlaps that tooth, simultaneously first hit on or near the pitch circle r of the teeth of sprocket 10. . Then, as the chain advances further and wraps around the sprocket, and the link plate rotates around the connecting pin 6, the third
Like the link plate 2c shown in the figure, both outer flanks 4 contact the teeth 11 of the sprocket on the engagement pitch circle of the sprocket. It then maintains this state until it separates from the sprocket, meshing with the teeth of the sprocket and moving together.

In FIG. 4, a portion of another embodiment of the invention is shown. In this embodiment, the amount of protrusion of the inner flank of the link plate is made irregular for each row of the link plate within the range of P ₂ > P ₁ > P ₃ .

In this embodiment, the sound generated during meshing is made non-periodic, reducing harsh noise and mitigating impact.

(g) Effects According to the present invention, the following effects can be achieved.

When the silent chain meshes with the sprocket teeth, it can reduce and disperse the periodic noise when the silent chain meshes with the sprocket teeth because the inner flank contacts the sprocket teeth and then the outer flank contacts the teeth of the sprocket. .

The impact during meshing is alleviated, and the durability of the contact surfaces of the link plate teeth and sprocket teeth can be improved.

[Brief explanation of drawings]

Fig. 1 is a side view of a part of an embodiment of the silent chain of the present invention, Fig. 2 is a top view of the silent chain shown in Fig. 1, and Fig. 3 shows a state in which the silent chain shown in Fig. 1 is engaged with a sprocket. 4 is a side view of a part of another embodiment of the silent chain of the present invention, FIG. 5 is a diagram showing a part of an example of a conventional silent chain, and FIG. 6 is a side view of a part of an example of the conventional silent chain. FIG. 7 is a diagram showing a part of another example of the conventional silent chain, and FIG.
FIG. 3 is a diagram showing a state in which the silent chain shown in the figure is engaged with a sprocket. 1, 1'... Silent chain, 2... Link plate, 3... Teeth, 4, 4'... Outer flank, 5, 5', 5''... Inner flank.

Claims (1)

[Claims] 1. A plurality of link plates each having a pair of teeth defined by an inner flank and an outer flank and a pair of holes into which a connecting member is inserted are connected endlessly by the connecting member. In the silent chain, the shape of the inner flank and the outer flank is such that the pitch between the outer flanks on the pitch line when the teeth of the pair engage is P ₁ , and the shape of the inner flank and the outer flank is P 1 when the silent chain extends substantially in a straight line. P ₂ is the pitch between the inner flanks of the teeth of the other two link plates that mesh with the tooth, and P ₃ is the pitch between the inner flanks when the silent chain is wrapped around the sprocket, then P ₂ > ≒P A silent chain characterized by being formed so that ₁ > ≒ P ₃ . 2. The silent chain according to claim 1, wherein link plates having different arcuate projection amounts of the inner flanks are irregularly arranged in the longitudinal direction of the silent chain.