JPH0156303B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a silent chain, and more specifically, it has a pair of long and short connecting pins each having an arcuate cross-sectional shape, and guides both ends of the long connecting pin. The present invention relates to a silent chain in which the shear strength of a connecting pin of a silent chain fixed by being fitted into a hole in a plate is increased.

(B) Prior Art As shown in Fig. 6B, a so-called lock joint type silent chain has a link plate a that has a pair of teeth b that mesh with the sprocket teeth and a pair of holes c at positions corresponding to the teeth. 3 and 5, and a pair of long and short connecting pins d and e having an arcuate cross section as shown in FIG. 6C are inserted into the hole c. and connect the link plates by inserting them into the 6th link plate at each end of the row.
It is constructed by arranging a guide plate f without drive teeth as shown in Figure A, and fitting and fixing both ends of a long connecting pin into an arcuate hole g of the guide plate f.

By the way, in a rotary joint type silent chain, it is essential to fix one of the pair of connecting pins to the guide plate and to allow the other connecting pin to swing freely with respect to the guide plate. Conventionally, only one long connecting pin was fixed to the guide plate as described above.

On the other hand, when tension is applied to the silent chain, the link plates a are alternately pulled in opposite directions, so that shearing force acts on the connecting pins, producing shearing stress. The maximum value of this shear stress occurs where the effective cross-sectional area of the connecting pin is the smallest, so in conventional silent chains, it is greatest at the root of the long connecting pin to the guide plate.

For this reason, in conventional silent chains, when a large load is applied, the long connecting pins break at this root portion, causing the problem that the chain becomes unusable.

(c) Problems to be solved by the present invention The problems to be solved by the present invention are to use a link plate stacked on a guide plate as an auxiliary plate, and to make some of the link plates in a link row thicker than other link plates. By doing so, the tensile strength of the silent chain can be made substantially uniform and large in an inexpensive manner.

(d) Means for Solving the Problems In order to solve the above problems, the present invention provides a plurality of link plates each having a pair of drive teeth that engage with the teeth of a sprocket and a pair of holes, which are inserted into the holes. In a silent chain, the guide is connected side by side in the lateral and subordinate directions by a pair of long and short connecting pins, and the ends of the long connecting pins are fitted and fixed into holes in guide plates arranged on both sides of the link plate. An auxiliary plate is stacked on the inside of the plate, and the end of the short connecting pin is fitted into the hole of the auxiliary plate, so that the thickness of at least one link plate in the link row without the guide plate is reduced to that of the other. The thickness is approximately twice or more than that of the link plate.

(e) Operation When the silent chain having the above structure is connected endlessly and hung on a sprocket to operate the driving sprocket, power is applied to the silent chain, and the power is transmitted from the silent chain to the driven sprocket. When tension is applied to the silent chain, a substantially equal shearing force is applied to the connecting pins as a whole.

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

1 and 2, a silent chain 1 according to this embodiment is shown. In the figure, 2 and 2' are link plates in which a pair of teeth 3 and a pair of holes 4 are formed, 5 is a guide plate in which a pair of arcuate holes 6 are formed, and 7 and 8 are mutually rotated into the holes 4. Long connecting pins (hereinafter referred to as long pins) and short connecting pins (hereinafter referred to as short pins) that are movably inserted.
Their shapes are the same as the conventional link plate, guide plate and connecting pin shown in FIG. A plurality of link plates 2 and 2' are lined up horizontally with a gap equal to the thickness of the link plates to form a row, and the adjacent link plate is inserted into the gap to insert the connecting pin 7 and the link plate into the hole 4. and 8 are inserted to connect them in the lateral and longitudinal directions. Guide plates 5 are arranged every other row on both outer sides of the horizontal rows of link plates. In this way, rows with guide plates on both sides (hereinafter referred to as guide rows) and rows without guide plates (hereinafter referred to as link rows) alternate over the entire length of the silent chain.

In the present invention, an auxiliary plate 2a having the same shape as the link plate 2 is placed on the inner side of the guide plate and between the link plate on the outer side of the link row and overlaps the guide plate 5. The long pin 7 is fitted into the hole 6 of the guide plate and fixed by caulking the end. Further, the short pin is inserted into the hole 4a of the auxiliary plate 2a superimposed on the guide plate 5. Further, among the link plates in the link row, the link plates 2' on both sides are approximately twice as thick as the other link plates 2. To make the thickness of the link plate 2' approximately twice the thickness of other link plates, you can stack two link plates 2 of the same thickness as shown in the figure, or It is also possible to use one with a uniform thickness.

Note that the positions of the link plates that approximately double the thickness are not limited to both sides of the link row as shown in the figure, but may be placed on the inner two link plates located symmetrically about the center line B-B. Furthermore, as shown in Figure 2, the thickness of the link plates on both sides of the link row is approximately doubled, and the thickness of the central link plate is also approximately doubled (therefore, the total of three link plates is approximately doubled). (double the thickness).

The silent chain 1 having the above structure is also connected to the driving and driven sprockets in the same manner as the conventional silent chain, and transmits power from the driving sprocket to the driven sprocket. When tension is applied to the silent chain, the link plates of the guide row and the link plates of the link row are pulled in opposite directions, so the long pin 7 and the short pin 8
A shear force acts on the Moreover, near both ends of the long pin 7, two pins, a long pin and a short pin, are inserted up to the hole in the auxiliary plate, and conventionally, the pull in the opposite direction between the outermost link plate of the link row and the guide plate In the chain of the present invention, a shearing force approximately equal to the shearing force generated by When it becomes a book, its effective cross-sectional area doubles. Therefore, the stress acting on the connecting pin becomes almost uniform, and the tensile strength also increases. In addition, the difference between the effective cross-sectional area of the link plates in the link row (proportional to the number and cross-sectional area of the link plates) and the effective cross-sectional area of the link plates in the guide row (including guide plates and auxiliary plates) can be reduced, so the chain Tensile strength can be made uniform over the entire tension.

Note that almost no shearing force acts between the guide plate 5 and the auxiliary plate because they receive a tensile force in the same direction.

In FIG. 3 a variant of the silent chain according to the invention is shown. In this embodiment, the link plate in the center of the link row is stacked with 4 (or 2 or 3) plates, and the other link plates are stacked with about 4
The thickness is doubled (may be 2 to 3 times), and the effective cross-sectional area of the link plate of the link row is made the same as the effective cross-sectional area of the link plate of the guide row.

(g) Effects The silent chain according to the present invention can have the following effects.

Breakage at both ends of the connecting pin can be completely prevented, and the allowable tensile strength of the chain can therefore be increased to the shear strength of the two connecting pins.

The tooth width of the sprocket that engages with the chain can be increased by the amount of the auxiliary plate, and the strength of the sprocket teeth can be increased by that amount.

Since the number of link plates in the conventional guide row is one less than the number of link plates in the link row, the contact pressure of the sprocket per link plate is higher than that of the link plate in the guide row, and the contact surface with the sprocket is higher than that of the link plate in the guide row. The movement of the link plates in the link row was hindered and the bending properties of the chain were deteriorated due to sagging and "burrs". However, in the present invention, the number of link plates can be made the same in both the guide row and the link row. Problems like this can be eliminated.

Since the link plate can be used as it is as an auxiliary plate, there is no need to make special parts and the cost can be reduced.

Since the effective cross-sections of the link plates in the link row and the effective cross-sectional areas of the link plates (including guide plates and auxiliary plates) in the guide row can be made close to each other, the strength of the chain can be made uniform.

[Brief explanation of drawings]

FIG. 1 is a side view of a part of an embodiment of the silent chain according to the present invention, with a part of the guide plate removed, and FIG. 2 is a side view of a part of the silent chain according to the present invention.
3 is a sectional view of another embodiment, FIG. 4 is a side view of a part of a conventional link plate, and FIG. 5 is a sectional view taken along line B-B in FIG. 3. cross section,
FIG. 6 is a perspective view of a link plate, a guide plate, and a connecting pin of a conventional silent chain. 1, 1'... Silent chain, 2, 2'...
Link plate, 2a... Auxiliary plate, 3...
Drive tooth, 4... hole, 5... guide plate, 6...
...Hole, 7, 8...Connection pin.

Claims (1)

[Claims] 1. A plurality of link plates each having a pair of driving teeth and a pair of holes that engage with the teeth of a sprocket are connected side by side in the horizontal and vertical directions by a pair of long and short connecting pins inserted into the holes, and the long connection is made. In a silent chain in which the ends of the pins are fitted and fixed into the holes of guide plates placed on both sides of the link plate, an auxiliary plate is placed overlappingly inside the guide plate to secure the ends of the short connecting pins. A silent chain fitted into a hole of the auxiliary plate, wherein the thickness of at least one link plate in the link row without the guide plate is about twice or more thicker than the thickness of the other link plates.