JPS6344598Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sheet metal pulley for a timing belt in a vehicle or the like.

Cast metal pulleys, which have traditionally been used for timing belts, have recently been replaced by sheet metal pulleys that can be manufactured by press working due to demands for lighter weight and lower costs.

FIG. 1 shows a typical sheet metal pulley 1. As shown in FIG. That is, this sheet metal pulley 1 is normally manufactured by deep drawing a single thin plate, whereby the side plate 3 is integrally formed so as to cover one side of the rim portion 2, and the rim portion rectangular wave-shaped teeth 4 are formed on the circumferential surface of the side plate 2, and a bowl-shaped boss mounting plate portion 5 is formed by protruding the center portion of the side plate 3 into the inner cavity of the toothed rim portion. It is.

The sheet metal pulley 1 can be easily manufactured by normal sheet metal processing using a press, and has the advantage of being lightweight and reducing costs. In comparison, the strength is inferior, and in particular, since the toothed rim portion 2 is forced to have a cantilevered structure by the molded upper side plate 3, there is a risk that harmful deflection or deformation may occur due to the load applied by the belt.

In order to solve such problems, conventionally, as shown in FIG. There are some intended for reinforcement against bending or deformation.

Therefore, in order to achieve a satisfactory reinforcing effect with this reinforcing means, it is necessary to increase the taper angle and make the slope steeper. If the entire length of the tooth 4 is formed to have a steep slope, the height of the entire length of the tooth 4 will inevitably become higher as the taper angle becomes steeper. However, considering the current situation where a thin plate must be pressed and bent alternately to form very narrow peaks and valleys around the entire circumference of the rim portion 2, it is necessary to form teeth that can be formed using press processing technology. There are limits to the height of the peaks and the depth of the valleys, and making the slope steeper than these limits causes problems such as thinning of the side walls and impractical use.

Therefore, the above-mentioned taper processing by press molding is practically difficult, and in the end, the conventional method cannot achieve the desired reinforcement purpose. In addition, if the peaks of the belt come into contact with the bottom surface of the valleys 6 of the teeth 4 of the pulley due to the design of the belt and the sheet metal pulley 1, or due to belt elongation or wear, the valleys 6
Since the entire length of the bottom surface is tapered, there is also the drawback that the belt may shift along the taper, causing it to shift to one side or fall off.

The present invention aims to solve the above-mentioned drawbacks of the prior art while achieving a good reinforcement purpose, and FIGS. 2 to 6 show embodiments constructed in accordance with this purpose.

In the figure, the sheet metal pulley 1 is formed by deep drawing a sheet metal using a press, etc., and as explained based on FIG. Molded in one piece,
Teeth 4 having a rectangular wave shape are formed on the rim portion on the inner circumferential surface and outer circumferential surface of the plate thickness.

In the sheet metal pulley 1 of the present invention, the peaks 7 of the teeth 4 are arranged so as to extend linearly and parallel to each other in the belt hanging surface area, and the bases of the valleys 6 of the teeth 4 are connected to the side plate 3. A slanted trough 6b is formed on the outer and inner surfaces of the plate thickness, and the slanted trough 6b is arranged so as to exist in the belt hanging surface area, that is, the extension area of the parallel ridges 7, and the slanted trough 6b 6b, a parallel valley portion 6a parallel to the tooth ridges 7 is formed on the outer and inner surfaces of the plate thickness, and the parallel valley portion 6a is formed in the above-mentioned belt hanging surface area, that is, an extension of the parallel ridges 7. the sloping valley portion 6b and the connected bent portion of the side plate 3 are used as a first fulcrum _P1 for the load on the rim portion;
The continuous bent part of the inclined valley part 6b and the parallel valley part 6a is defined as the second fulcrum _P2 , and by forming the inclined valley part 6b, the length of the parallel valley part 6a, that is, from the tip of the tooth 4 to the second The length of the parallel valley part 6a between the fulcrum _P2 is made as short as possible, and the structure is such that bending does not occur even if the wall is thin.
A steeply sloped valley portion 6b is arranged between the second fulcrum P ₂ and the first fulcrum P ₁ to provide a good bracing effect on the rim portion 2,
That is, it is designed to have a reinforcing effect.

As described above, the sheet metal pulley 1 of the present invention has a structure in which the belt hanging area, that is, the area where the parallel ridges 7 extend, has both the above-mentioned inclined valley part 6b and parallel valley part 6a, and is connected to the side plate 3. , the inclined valley portion 6b exists in the extension area of the parallel crest 7 on which the belt hangs, and the side plate 3
Since it is limited only to the extreme part of the valley 6 that connects to the tooth, it is possible to form the valley 6 to a desired depth by pressing, and the taper angle is smaller than when tapering the entire length of the valley 6 of the tooth. can be made larger to make it steeper, and therefore, in combination with forming the inclined valley part 6b in the belt hanging area, that is, the extension area of the parallel valley 7, the slope is added to the rim part 2, that is, the parallel valley 7. It is possible to sufficiently increase reinforcement against loads. Further, by forming the inclined valley portion 6b, the length of the parallel valley portion 6a of the tooth 4, that is, the distance from the second fulcrum to the tip of the tooth 4 in the extension area of the parallel peak 7 can be shortened as much as possible. It is possible to ensure sufficient stiffness against the bending load applied to the rim portion 2, that is, the parallel ridges 7, and in cooperation with the reinforcing action of the steeply sloped valley portion 6b that supports the parallel valley portion 6a, this eliminates the drawbacks of sheet metal pulleys. The strength problem of the barrel toothed rim portion 2 can be effectively overcome.

Further, even if the peaks of the belt come into contact with the bottoms of the valleys 6, there is an advantage that the belt does not shift in the lateral direction due to the existence of the parallel valleys 6a.

In addition, since the above-mentioned inclined valley part 6b and parallel valley part 6a are formed in the extending region of the parallel peak 7 in the belt hanging region and have the above-mentioned reinforcing function, the width of the rim part can be maintained as usual without increasing the width of the rim part. This has the advantage of not requiring a large pulley.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional sheet metal pulley, Fig. 2 is a perspective view of a sheet metal pulley according to the present invention, Fig. 3 is a rear view of the same, Fig. 4 is a front view of the same, and Fig. 5 is a sectional view of the same. FIG. 6 is an enlarged plan view of the tooth portion. 1... Sheet metal pulley, 2... Rim part, 3... Side plate, 4... Teeth, 5... Boss mounting plate part, 6...
Valley, 6a...parallel valley, 6b...slanted valley, 7...
...parallel mountain, P ₁ ... first fulcrum, P ₂ ... second fulcrum.

Claims (1)

[Scope of utility model registration request] A sheet metal consisting of a single metal plate in which a side plate is integrally molded so as to cover one side of a rim part, and the rim part is formed with teeth forming a rectangular wave state on the inner and outer peripheral surfaces of the plate thickness. In the pulley, the crests of the teeth are arranged so as to extend linearly and parallel to each other in the belt hanging surface area, and the base end of the trough of the teeth that connects to the side plate is sloped on the outer and inner surfaces of the plate thickness. A sloped valley is formed, and the sloped valley is arranged so as to exist in the belt hanging surface region, that is, the extending region of the parallel ridges, and further, the outer surface of the plate thickness and the part facing the valley tip connected to the sloped valley are A parallel valley portion parallel to the ridges of the teeth is formed on the inner surface, and the parallel valley portion is arranged so as to exist in the belt hanging surface area, that is, the extension area of the parallel ridges, and the inclined valley portion and the side plate are connected to a bent portion. A sheet metal pulley, characterized in that: is a first fulcrum for the load on the rim portion, and a continuous bent portion of the inclined trough and parallel trough is a second fulcrum.