JPS6241443A - Link plate for silent chain - Google Patents

Abstract

PURPOSE:To prevent an extreme folding phenomenon of a chain to aim at facilitating the handling of the chain and at preventing erroneous function, by improving the shapes of shoulder and back sections of a link plate having small tooth dimension. CONSTITUTION:A drive link plate 1 is formed with a back section 10 and shoulder sections 11, 12 on both sides of the back section 10, at the side which is remote from teeth 4, 5 arranged on both side of a center line O-O. Projections 13, 14 are formed in the shoulder section 13, 14 or the back section 10, as means for preventing the drive link plate from turning in.

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a link plate for a silent chain,
More specifically, by shortening only the teeth of the link plates, it is possible to increase the root diameter of the sprocket, and when the chain is bent, one link plate can go over the shoulder of the other link plate. It is related to the ink plate that prevents it from going backwards.

(B) Prior art As shown in FIG. 6, in a link plate for a silent chain that has been commonly used in the past, a pair of tooth slots H in a link plate a are formed in a pair of holes formed in the link plate. Since the difference between the pitch p between C and the distance from the center of the C to the end of the link is larger,
Even if the silent chain tries to bend around the connecting pin, the tip of the tooth will touch the tip d or shoulder e of the lb of the adjacent link plate, as shown in Figure 6. The tip of the tooth will not go over the shoulder of the link plate and into the back of the link plate.

However, in recent years, silent chains have come to be used for power transmission in motorcycles and other vehicles, and in order to meet the demands for higher performance and more compact motorcycles, it has become necessary to integrate power transmission mechanisms that use silent chains. It has become. For this reason, it is necessary to reduce the number of sprocket teeth for silent chains as much as possible to make them more compact.However, in silent chains using conventional link plates as shown in Figure 6, interference occurs at the root of the sprocket teeth. This causes problems such as a so-called undercut phenomenon occurring at the root of the teeth, and the diameter of the root of the sprocket becoming smaller, resulting in a smaller shaft diameter of the crankshaft, resulting in insufficient strength.

As a way to solve this problem, as shown in FIG. One possible method is to cut off the tip of the glass.

However, with this method, when the chain is packed in a folded state, or when extremely strong string vibrations are applied to the chain during operation, the link plates may be in the state shown by the chain line in Figure 7. From there, further center line (line passing through the center of the two holes...the same applies hereafter)X-
The center line Y-Y of the adjacent link with respect to X rotates in the direction of the arrow, so that the angle α between them becomes smaller, or the center line z-7 rotates counterclockwise with respect to the center line Y-Y. As the tooth rotates, the angle β becomes smaller, and the tip d of the tooth becomes the shoulder.

If the chain goes around or goes over the chain, the tip of the tooth may hit the shoulder of the link plate and be unable to return even if you try to straighten the chain. In particular, when P is approximately equal to the sum of the tooth height H and the distance from the center of the hole to the end of the link plate, the tip of the tooth strongly hits the shoulder, which is particularly problematic.

(・→ Problem to be solved by the present invention) The problem to be solved by the present invention is to solve the problem by improving the shape of the shoulder or back part of a silent chain link plate with only small teeth. The purpose is to prevent the bending phenomenon, simplify handling, and prevent malfunctions.

(Means for Solving the 4 Problems) In order to solve the above problems, the present invention provides a pair of holes into which the connecting member is inserted, a back portion formed on one side of the large size, and a hole continuous to the back portion. A link plate for a silent chain having a shoulder portion is provided, and when the link plate is connected to at least one of the shoulder portion and the back portion of the link plate, the adjacent link plate extends beyond the shoulder portion or the back portion. The structure is provided with a wrap-around prevention means to prevent this.

(e) Effect In the above configuration, when a silent chain is made by connecting multiple link plates with connecting members, even when the chain is folded, one link plate is placed in between and one link plate is adjacent to the other. The link plate will not come around beyond the shoulder or back of the other link plate by hitting the wraparound prevention means.

(f) Examples Examples of the silent chain link plate according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a power transmission link plate (hereinafter referred to as a drive link plate) 1 for a silent chain according to an embodiment of the present invention.

In the figure, reference numerals 2 and 3 indicate holes into which link connecting members, such as connection pins, are inserted, and 4 and 5 indicate teeth provided at positions corresponding to the holes 2 and 3, respectively.

Each tooth 4 and 5 has an outer tooth surface 6 which is oblique with respect to a line connecting the centers of holes 2 and 3 (hereinafter referred to as center line) O-OK,
8 and the inner bite surfaces 7,9.

The tips of the teeth 4 and 5 are shaved off compared to the conventional ones, and the tooth height H' is reduced.

The height of the gold teeth 4 and 5 is H/, the distance between the centers of the two holes 2 and 3, or the pitch, is P, and the center line from the center of one hole is O-0.
Letting L' be the distance to the intersection of the line and the extension of the outer bite surface, H' is determined to satisfy the relationship H' (P - L').

The drive link plate IK has a back portion 10 and shoulders 11 on both sides of the back portion on the side opposite to the teeth 4 and 5 with respect to the center line O-0.
, 12 are formed. In the conventional driving link plate, the shoulder part is formed of an arcuate surface with a radius of curvature of r smaller than L' and the center of curvature is the center of the hole, as shown by the chain line in Fig. 1. In the embodiment, the protrusion 13 has a distance from the center of the hole to the tip having a value R larger than L/
．． 14 is formed at a position offset to the center line ○-0. These protrusions 13 and 14 form means for preventing the drive link plate from turning around. Further, the back portion 11 is cut out in a straight line.

In FIG. 2, a drive link plate 1a of another embodiment is shown.
It is shown. This driving link play (1a) has the entire shoulders 11a, 12a protruding so that their tips touch a radius of curvature R' larger than L', thereby forming a wraparound prevention means.

The rest of the structure is the same as the previous embodiment.

FIG. 3 shows a portion of a silent chain in which the drive link plates of FIG. 2 are connected by connecting pins (not shown). In the link plate of this embodiment, even if the siren 1 chain is bent at the connecting position as shown by the chain line, the teeth of the adjacent link plate one space apart can be bent.
Since the tip of the tooth a hits the shoulder 11a formed in a protruding shape, the tip of the tooth is prevented from getting over the shoulder and turning toward the back as shown by the arrow U. This means that no matter how the chain tries to bend, the tips of the teeth will always hit the shoulder, preventing the tips of the teeth from turning past the shoulder.

This anti-circumvention function is achieved in the same manner as in the drive link plate of FIG. 1, by the projections 13, 14 formed on the shoulders 11, 12 coming into contact with the tips of the teeth.

In FIG. 4, a further embodiment of a drive link plate 1b is shown. In this drive link plate, the shoulders 11b and 12b have a radius of curvature r smaller than L'.
However, the height of the back portion 10b, that is, the height F from the center line ◯-0 is greater than L', thereby forming a means for preventing rotation. The rest of the structure is the same as the previous embodiment.

In the drive link plate of this embodiment, the tip of the tooth of the adjacent drive link plate can be freely rotated to the shoulder position of the other drive link plate, but it hits the back and cannot be rotated further. Wrapping is prevented.

Figure @5 shows an embodiment in which the present invention is applied to a guide link plate that is not directly involved in power transmission and prevents a silent chain from coming off a sprocket.

The guide link plate 21 has, instead of a pair of teeth, a pair of inclined surfaces 26, 28 substantially similar to the outer tooth surfaces of the drive link plate and a surface 27 parallel to the center line o' - o'.
It has a guide portion 24 defined by a shoulder portion 3.
The anti-wrapping means formed at 1.32 are formed by projections 33.34 in substantially the same way as in the embodiment of FIG.

The operation of this four-guide link plate is the same as that of the previous driving link plate, and by simply providing the guide link plate with a rotation prevention means, it is possible to prevent the silent chain from being bent excessively.

Furthermore, the guide link plate may be provided with wraparound prevention means as shown in FIGS. 2 and 4.

In the above embodiments, the protrusions are formed on the entire back or shoulders, but they may be locally small and may have any shape.

(g) Effects The links and plates according to the present invention can have the following effects.

■ Since only the teeth of the link plate can be made smaller, the diameter of the sprocket tooth bottom can be increased, and undercuts can be prevented, allowing large power transmission even with a small size.

■ Since the silent chain can be prevented from being bent excessively, there will be no malfunction due to string vibration during operation, and even if it is folded and packed, it can be immediately unfolded, making it easy to handle.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a first embodiment of a link plate for a silent chain according to the present invention, FIG. 2 is a plan view of a link plate according to the 62nd embodiment of the present invention, and FIG. 4 is a plan view of a link plate according to a third embodiment of the present invention, FIG. 5 is a plan view of a link plate according to a fourth embodiment of the present invention, and FIG. 6 is a conventional link plate. FIG. 7 is a diagram illustrating the rotation of a link plate in which only the teeth are reduced. 1.1a + lb, 21: link plate 2 + 3
+ 2a, 3a H2b+ 3 bg22123
: Hole 4, 5, 4a, 5a, 4b, 5b124,
25: Teeth 13.14: Protrusion (5 people outside) Figure 1 Figure 2

Claims (1)

[Claims] A link plate for a silent chain having a pair of holes into which a connecting member is inserted, a back portion formed on one side of the hole, and a shoulder portion continuous to the back portion, wherein at least the shoulder portion and the back portion of the link plate A link plate for a silent chain, characterized in that a link plate for a silent chain is provided with a wraparound prevention means for preventing an adjacent link plate from wrapping around beyond the shoulder or back when the link plates are connected.