JPS61211556A - Link for silent chain - Google Patents

Abstract

PURPOSE:To prevent noise due to collision between a link and a sprocket by forming the link tooth flank such that the tooth flank of the link tooth will slip contact with the tooth flank of the sprocket upon gearing of the chain link with the sprocket. CONSTITUTION:Point O' is set on the extension of a line passing through the centers of a pair of holes 2, 3 to be inserted with a coupling member while being separated by same distance P with that between the centers of said holes 2, 3. While the radius R of a circle circumscribing with the tooth flank of a sprocket 10 around the point O' when two adjoining links at the extended side of said line will gear with the sprocket 10 and become standstill with respect to the sprocket 10 is obtained. The inside tooth flank 7 at the extended side of line is formed by an arched face having the curvature of R around the point O' while the inside tooth flank 9 of the tooth 5 is also formed symmetrically with the inside tooth flank 7 against the center line of the link 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a link for a silent chain, and more specifically, the link teeth slide into contact with the sprocket teeth at the start of engagement with the sprocket or when separating from the sprocket. Regarding links for silent chains.

(b) Prior art In a winding transmission mechanism having a connection part at each pitch, such as a silent chain or a roller chain, when the chain is wrapped around a sprocket, rotational movement is performed around the connection part. Such a winding transmission mechanism generates a unique noise during operation, and the sources of this noise are: ■ The impact of the chain parts together, ■ The string vibration of the chain span, and ■ The collision between the link plate and the sprocket. The meshing sounds that occur can be classified into three types.

Among these noises, the sounds generated by ■ and ■ are white noise-like sounds, and when used as components of four-wheeled vehicles or two-wheeled vehicles, it is easy to implement side noise countermeasures and does not pose much of a problem. The resulting meshing noise is a periodic high-pitched sound that is proportional to the number of sprocket rotations and the number of teeth. As shown in Fig. 4, this sound occurs when the link plate (a) completes its rotational movement around the link pin (p) just before it engages with the sprocket (b).
This occurs when the tooth surface C of the sprocket B collides with the tooth surface d of the sprocket B at point A, and it is extremely unpleasant to the ear and has the property of making it difficult to take sound insulation measures.

In order to reduce such noise, there have conventionally been methods to reduce the collision speed by changing the meshing pressure angle between the sprocket and the chain;
As shown in Publication No. 7333 or US Pat. No. 3,495,468, the tooth surface of the sprocket is shaved off in places so that it does not come into contact with the chain, thereby dispersing meshing synchronization, or Or JP-A-57-22
As shown in Japanese Patent No. 443, a method has been adopted in which link plates with different meshing timings are arranged irregularly in one chain to scatter the meshing periods.

However, the above method (■) cannot be expected to be very effective, and the methods (■) and (2) have little difference between periodic peak sounds and other sounds (thus, the harshness is reduced, but the low-frequency sounds are new). There is a problem that can occur.

(c) Problems to be Solved by the Invention The problem to be solved by the invention is that when the links of the silent chain are engaged with the sprocket, the teeth of the links slide into the teeth of the sprocket so that the teeth mesh with each other. This is to prevent the generation of noise due to collision between the link and the sprocket.

(B) Means for Solving the Problems In order to solve the above problems, the present invention provides a pair of holes into which the connecting member is inserted, and a sprocket tooth that is formed at a position corresponding to the crest hole. A silent chain link having a pair of intervening link teeth, the link teeth being defined by an inner tooth surface and an outer tooth surface that are oblique with respect to a line passing through the center of the pair of holes, the inner tooth surface is centered on a point that is on an extension of said line and is spaced from the center of the hole corresponding to the tooth defined by said inner tooth surface by the same distance as the distance between the centers of said pair of holes, and that is two adjacent points. When the link is fixed on the outer periphery of the sprocket, the point is the center of curvature, and the radius of curvature is the radius of the circle circumscribing the tooth surface of the tooth of the sprocket that engages with the sprocket. formed and composed.

(e) Effect In the above configuration, when power is transmitted by connecting a large number of links with connecting members and wrapping an endless chain around a sprocket, the link has already completed engagement just before the link engages with the sprocket. The link tooth rotates about the link that is stationary with respect to the sprocket, and the link tooth enters between the teeth of the sprocket, and at this time, the tooth surface of the link tooth slides into contact with the tooth surface of the sprocket.

(4 examples Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a link 1 for a silent chain according to an embodiment of the present invention is shown. In the same figure, 2 and 3
is a hole into which a connecting member of the link, such as a connecting pin, is inserted;
4 and 5 are link teeth provided at positions corresponding to holes 2 and 3, respectively.

Each link tooth 4 and 5 is defined by an outer flank 6, 8 and an inner flank 7, 9 which are oblique with respect to the line xx connecting the centers of the holes 2 and 3.

The inner tooth surface 7 is on the extension line of the line x-x and the distance between the center of the hole 2 and the center of the hole 3, that is, the pitch p
It is formed of an arcuate surface having a radius of curvature H and centered at a point O' separated by a distance. This point O' is connected to another adjacent link (not shown) connected by a connecting member (not shown) K inserted into the hole 2 corresponding to the link tooth 4 defined by the inner tooth surface 7. It is also the center of one of the holes.

The radius of curvature R is such that the further adjacent link connected to the adjacent other link with the center at point 0' has sprocket 1.
When the sprocket is in a stationary state by meshing with tooth No. 0, as shown in FIG.
, llb, the tooth surface 12 of the tooth 11b that contacts the inner tooth surface.
1) is the radius of curvature of the circular arc circumscribing.

The other inner tooth surface 9 is the center line of the link Y-Y
The detailed explanation will be omitted since it can be formed in the same manner as described above in an antisymmetrical manner.

The outer tooth surfaces 6 and 8 may be flat or curved surfaces as long as they do not come into contact with the teeth of the sprocket 10 when the link meshes with the sprocket.

When a silent chain in which a large number of links 1 are connected is engaged with a sprocket, for example, sprocket 10
When the link rotates in the direction of the arrow and the links of the silent chain engage the sprocket in sequence, when the preceding link is stationary with respect to the sprocket, the next link is
', and the next link 1 also rotates in the same way, so that the slotted teeth 4 are connected to the sprocket teeth 11a and 111.
) will be busy. At this time, due to the nature of the arcuate curved surface of the inner tooth surface 7, the link tooth 4 slides between the teeth 11a and llb while the inner tooth surface 7 slides into contact with the flesh of the sprocket. Therefore, it is possible to prevent noise caused by conventional chains due to collisions between links and sprockets.

In FIG. 3, another embodiment of the silent chain link 11 is shown. In the same figure, 2' and 3'
is a hole, 4' and 5' are link teeth, 6' and 8' are outer tooth surfaces, and 7' and 9' are inner tooth surfaces.

In this embodiment, the outer tooth flank 6' is an arcuate surface having a center of curvature at the center O of a hole 3 other than the hole 2 corresponding to the link tooth 4' defined by the outer tooth flank and having a curvature R'. The other outer tooth surface 8' has a center of curvature at the center of the hole 2' which is different from the hole 3' corresponding to the link tooth 5' defined by the outer tooth surface 8' and has a radius of curvature R'. It is formed by an arc-shaped surface.

The radius of curvature R' is determined in the same manner as in the previous embodiment. That is, for example, when the link adjacent to the right side of link l' meshes with the outer periphery of the sprocket and becomes stationary with respect to the sprocket, the center of curvature is the center O of hole 2', and the two teeth of the sprocket into which link tooth 5' enters ( (not shown) is the radius of curvature of the circular arc surface that circumscribes the tooth surface of the tooth with which the tooth surface 8/ contacts.

In this embodiment, the inner tooth surfaces 7' and 9' may be flat or curved as long as they do not come into contact with the sprocket teeth during meshing operation. Furthermore, it may be formed into an arcuate surface with a curvature R', similar to the embodiment shown in FIG.

In the link 1' of this embodiment, when the link 1' engages with the sprocket, the outer tooth surface comes into sliding contact with the tooth surface of the corresponding sprocket tooth as in the previous embodiment, so that the link and the sprocket tooth do not interact with each other as in the prior art. Noise generation due to collisions can be prevented.

(H effect According to the present invention, the following effects can be achieved.

■ When a link meshes with a sprocket, the tooth surface of the link and the tooth surface of the corresponding sprocket come into sliding contact, causing the link tooth to slide between the teeth of the sprocket, eliminating collision between the teeth and creating a matching sound. can be prevented from occurring.

O In (2) above, when the link teeth slide between the sprocket teeth, part of the tension acting on the chain is shared, so the pressure between the connecting member and the inner surface of the hole in the link is reduced, and wear on the slotted connection can be reduced.

θ By randomly using the links of the present invention in the conventional chain (2) described above, it is possible to manufacture a chain that reduces meshing noise and does not generate low-frequency noise.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the silent chain link according to the present invention, and FIG. 2 shows how the curvature of the arcuate inner tooth surface of the link of FIG. 1 is taken and the meshing operation of the sprocket of the link. FIG. 3 is a plan view of a link for a silent chain according to another embodiment, and FIG. 4 is a diagram showing a state in which the links of a conventional silent chain collide with the teeth of a sprocket.

Claims (1)

[Claims] 1. A sprocket having a pair of holes into which the connecting member is inserted, and a pair of link teeth formed at positions corresponding to the holes and inserted between the teeth of the sprocket, the link teeth being inserted into the sprocket. In a silent chain link defined by an inner tooth surface and an outer tooth surface that are oblique with respect to a line passing through the centers of a pair of holes, the inner tooth surface is defined by the inner side surface on an extension of the line. The center is a point that is spaced from the center of the hole corresponding to the tooth that is the same distance as the distance between the centers of the pair of holes, and when two adjacent links are fixed on the outer periphery of the sprocket. The radius of the circle circumscribing the tooth surface of the sprocket tooth that engages with the link tooth as the center of curvature is the radius of curvature;
A silent chain link characterized by being formed with an arcuate surface. 2. It has a pair of holes into which the connecting member is inserted, and a pair of link teeth that are formed at positions corresponding to the holes and fit between the teeth of the sprocket, and the link teeth fit between the teeth of the pair of holes. In a link for a silent chain defined by an inner tooth surface and an outer tooth surface that are oblique with respect to a line passing through the center, the outer tooth surface corresponds to a link tooth different from the link tooth defined by the outer tooth surface. The center of the hole is the center of curvature, and when the adjacent link is fixed on the outer periphery of the sprocket, the center of curvature is the center of curvature, and the radius of the circle circumscribing the tooth surface of the tooth of the sprocket that engages with the other link tooth. A silent chain link characterized by being formed of an arcuate surface with a radius of curvature.