JPH0261340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a pulley by increasing the wall thickness of a specific portion of a metal plate, and an apparatus for carrying out the method.

[Conventional technology]

Methods for forming pulleys from sheet metal have been known for a long time, and in most cases are described in U.S. Pat.
No. 2,685,856 (August 10, 1954, Witsquier et al.), U.S. Pat. No. 1,828,464 (October 20, 1931, Harrison et al.), etc. Both of these patents are V
1 V-groove where the belt is applied and power is transmitted to the V-belt.
The present invention relates to a method of manufacturing a pulley having only one book. U.S. Patent No. 2,892,431 (June 20, 1952)
According to the method shown in Killian et al., it is also possible to produce a V-pulley having two V-grooves by drawing and drawing. However, this method requires a complicated machine, and at the same time, there is a problem that uneven thickness of the metal material occurs when forming the V-groove, and the pulley wall around the V-groove becomes thinner, which may cause the pulley to break during use. There is also.

Another method uses a die to form a pulley with more than one V-groove, as disclosed in U.S. Pat. No. 3,368,376 (Feb. 13, 1968, Pulley Bide). However, this method requires a complex die consisting of arcuate expansion segments;
To the best of the applicant's knowledge, it has never been put to practical use industrially.

In any of the above-mentioned methods, the pulley wall becomes thin when forming the V-groove on the pulley side wall, which may cause pulley damage. According to the method described above, this
One reason is that considerable thickness deviation inevitably occurs when forming the V-groove, and it is difficult to cause metal movement so that the thickness of all parts of the V-groove is appropriate after forming is completed. . Therefore, a fairly thick metal plate must be used to form the pulley so that the final pulley has sufficient strength to withstand the torsional stresses that are applied to the pulley during operation and tend to distort the pulley's circular shape. .

Pulleys manufactured using conventional drawing and drawing methods are also available.
It could be used to hang a V-shaped belt with one side flat and the other side concave. However, other types of belts, namely belts called poly V belts, have also been widely used for power transmission in special machines. The poly-V belt is flat on one side and has a plurality of serrations, typically six rows, on the other side. The use of this poly-V belt requires the formation of relatively close together, acute-angled V-shaped grooves on the pulley surface that match the serrated profile of the poly-V belt. Manufacturing pulleys has traditionally been difficult and requires a large amount of metal material. For this reason, if the pulley is manufactured using conventional drawing and drawing techniques or die forging techniques such as that proposed by Previte in US Pat. No. 3,368,376, the pulley wall must be relatively thick. Pulleys made in this manner are heavy and expensive to manufacture, and are not advantageous for use in automobiles, where low price and light weight are desired from the viewpoint of marketability. The lack of effective, low-cost, lightweight pulleys has prevented the widespread adoption of poly-V belts in automotive applications, despite their inherent advantages.

In most draw drawing or die forging methods, a flat metal plate is first drawn to form a blank (hereinafter referred to as a "blank") with a base and an upright cylindrical wall. Pulley grooves are formed on the surface of this blank by rolling or die forging.

[Problem to be solved by the invention]

Therefore, it is necessary to select a flat metal plate whose blank wall after drawing is thick enough to form a V-groove of appropriate strength for the intended use of the pulley. However, when squeezed, the thickness of the blank wall becomes the same as the base thickness or slightly thinner. Accordingly, with current processing methods, the metal sheet thickness is determined by the minimum allowable thickness of the blank wall. The base need not be of the same thickness or strength as the wall, since the stress on the base during pulley forming is less than the stress on the wall. Thus, from a cost standpoint, pulley blanks with thicker walls than bases often have many advantages.

It is an object of the present invention to increase the generally cylindrical wall of a pulley blank without increasing the thickness of the base of the blank, thereby increasing the strength and thickness not otherwise obtainable from the sheet metal of the pulley material. An object of the present invention is to provide a method and apparatus for manufacturing a pulley having a certain wall portion.

[Means to solve the problem]

According to the present invention, first of all, the entire cylindrical part is constructed such that the axial length of the cylindrical part is larger than the axial length of the completed cylindrical part in which the V-shaped groove is formed on the outside of the cylindrical part. A process of forming a substantially pot-shaped metal plate blank consisting of the cylindrical part and a circular base with a substantially uniform thickness; The cylindrical portion of the blank is partially crushed in the axial direction so that the metal plates overlap and do not touch each other when pressed inward. and then pressing the partially crushed corrugated portion radially inward against the outer circumferential surface of a cylindrical support member disposed concentrically inside the cylindrical portion with a roll, thereby compressing the cylindrical portion. A method of manufacturing a multi-groove V-pulley is provided, which includes the steps of: forming an inner circumferential surface of the pulley into a flat cylindrical surface, and roll-forming V-shaped grooves on the outer circumferential surface of the pulley.

Further, according to the present invention, the axial length of the cylindrical portion is greater than the axial length of the completed cylindrical portion with the V-shaped groove formed on the outside of the cylindrical portion, and the overall thickness is approximately Using a uniform substantially pot-shaped metal plate blank consisting of the cylindrical portion and a circular base, then:
The cylindrical portion of the blank is axially shaped so that the cross-sectional shape of the cylindrical portion at the axial center passing surface is corrugated to the extent that the metal plates do not overlap and come into contact with each other when pressed radially inward in the subsequent process. shortening the axial length of the cylindrical portion by partially crushing it in the direction;
Thereafter, the partially crushed corrugated portion is pressed radially inward to form a V-shaped groove by roll forming a multi-groove V.
An apparatus for use in a method for manufacturing a pulley, the apparatus comprising a concentric chuck on one side holding the preformed blank and a chuck on the other side concentric with the chuck on one side, one of which is pivoted to the other side. axially moving said cylindrical part by means of a mechanism for moving said cylindrical part in the direction and a roller having two spaced annular areas adapted to be moved towards said blank and projecting in the direction of and abutting said cylindrical part of said blank. It consists of a structure in which the length in the direction is shortened to form the wave-shaped part, a cylindrical support member arranged concentrically inside the cylindrical part, and a roll that presses the outer peripheral surface of the support member inward in the radial direction. There is provided an apparatus for manufacturing a multi-groove V pulley, including a structure in which the inner circumferential surface of the cylindrical portion is formed into a flat cylindrical surface and V-shaped grooves are roll-formed on the outer circumferential surface.

[Effect]

According to the present invention, by partially crushing the cylindrical portion of the blank in the axial direction, the length in the axial direction is shortened and the cross-sectional shape at the axis passing surface is made into a waveform. When pressing radially inward against the outer circumferential surface of the support member disposed concentrically inside the cylindrical portion, if the pressing is easy, the thickness of the cylindrical portion can be uniformly increased.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The simplest method for producing pulleys suitable for automotive poly V-belts is to first process a thin metal sheet into a pulley blank by deep drawing or spinning in the same manner as in the past. The sheet metal used in this case can be any sheet metal that is used for manufacturing pulleys by conventional drawing and drawing. The most common ones are aluminum sheets, hot-rolled low carbon steel sheets of practical quality, etc. The thickness of the metal sheet as shown in FIG. 1 is, for example, 0.08 inch (approximately 2 mm). Of course, metal plates thicker than this can also be used, and the upper limit of the thickness is determined by the intended maximum strength of the pulley and the counter pressure tolerance of the drawing machine or spinning drawing machine used for processing.

The present invention allows pulleys to be formed from thinner sheet metal with performance characteristics comparable to those that would otherwise be available only with pulleys formed from thicker special sheet metal. Since the advantages of the present invention are more pronounced as thinner metal plates are used, it is desirable to use thinner metal plates, i.e., 0.07 to 0.110 inches.

As described above, a pulley blank is formed in a conventional manner using a conventional deep drawing or rolling machine. In such a machine, a thin metal plate 1 shown in FIG. 1 is punched out into a circular shape, and then press-formed to form a substantially pot-shaped blank 15 having a base 10 and a cylindrical rising wall 11 as shown in FIG. . The dimensions of the blank are determined by the size of the processing equipment and the required dimensions of the final pulley, and can be formed to any size.

For example, in the case of a 6-inch pulley that is often used in automobiles, a 9-inch diameter disc is punched out and drawn to form a blank with a base diameter of 6.6 inches and a cylindrical rising wall 2 inches high. The blank 15 shown in FIG. 2 is representative.
The blank of FIG. 2 has a stepped base 10 and a cylindrical rising wall 11. The blank shown in FIG. The base 10 has a hole 12 through the center of the base for positioning the blank on the spinning drawer. A plurality of other holes may be provided for positioning or for tightening bolts when assembling the pulley.

Further, the base 10 of the blank need not have a stepped shape as shown in FIG. 2, but may have a flat or sloped shape as shown in FIGS. 2a and 2b. As indicated by the reference numeral 13 in FIG. 2b, not only one hole but also a plurality of holes may be provided in a desired arrangement. If necessary, U.S. Patent No. 2,696,740 (1954
(December 1, 2016)
The blank may also be attached to a hub formed from another piece of metal.

According to the method of the invention, the blank is mounted on a universal spinning and drawing machine. A machine of this type is itself a commercially available machine and is not shown here. This machine usually uses a workpiece (hereinafter referred to as "work").
A chuck that holds and rotates the work piece, and a tool holder that feeds the required tool back and forth with respect to the work rotation axis are provided. This machine is also configured to compress the workpiece along its axis of rotation. Third
In the figure, blanks having the shape shown in FIG.
It is installed between 0 and 0. The rotation axis of the blank is
It is shown by a straight line a-a passing through the chuck and blank. As is common in pulley spinning drawing technology, the blank is centered and positioned so that the axis of rotation of the blank coincides with the axis of rotation of the cylindrical blank wall. Such centering and positioning of the blank can be achieved by using the holding groove 21 provided in the lower chuck 20 and the center shaft 24 projecting from the upper chuck 23 and fitting into the hole 12, but other methods may also be used.

If desired, a cylindrical internal support member 60 may be secured to the lower chuck 20 for rotation therewith. The support member 60 has an upper chuck 2.
A recess 61 is provided in which the center shaft 24 is fitted when the lower chuck 20 and the lower chuck 3 are moved a predetermined distance. For the reasons described below,
It is preferable that the inner surface of the holding groove 21 be an inclined surface as shown by 25 in FIG. 3 rather than being vertical.

The upper chuck 23 is also provided with an annular inclined surface 26 opposite to the inclined surface 25, as shown in FIG.
If desired, the inner and outer flanges can be formed before the cylindrical upright wall is thickened and grooved therein.

Forming the inner and outer flanges in this step is not absolutely necessary, and as described later, they can be easily formed during the subsequent pulley forming step. However, as will be explained later, by forming the flanges in advance, partial "collapse" of the pulley wall can be better controlled, and in some cases it is more convenient to form both flanges first. It is. Figures 4a and 4b illustrate the method of flange formation. In FIG. 4a, the blank is positioned as in FIG. 3, and the roller 50 is shown approaching the blank. The roller 50 is rotatable about an axis c-c parallel to the axis a-a and movable back and forth with respect to the axis a-a. The roller 50 has a smooth, generally cylindrical outer surface 51 and two sloped sections 52, 53 adjacent to the cylindrical outer surface 51.

Further, as an alternative to the above, the roller may be made slightly concave if necessary. Such a roller may be mounted on a spring, as is well known in the art, so that when pressure is applied around it, the roller moves slightly up and down axially. In the example shown, this roller is not driven.

The lower chuck 20 and the upper chuck 23 are driven simultaneously, at the same speed, and in the same direction while supporting the blank 15 and the support member 60. During this rotation, roller 5
0 is moved to contact the surface of the blank 15. At the same time, the upper chuck 23 is lowered by a predetermined distance, and as a result, the surface 51 comes into contact with the blank wall 11, and as it advances further in the axial direction, the base portion 10 and the wall portion 11
The joint 16 with the blank is folded back by the pressure applied by the roller 51 to the blank. Slope portion 5 of roller
2 serves to smoothly bend the joint 16 of the metal plates.

Similarly, the sloped portion 53 serves to form a smoothly folded flange on the blank wall portion 17 furthest from the base of the blank. These flanges serve to hold the poly-V belt in place when the pulley is complete.

Although the above description will proceed assuming that the flange forming step described with respect to Figures 4a and 4b is not performed, those skilled in the art will appreciate that the method described below It is understood that a pulley blank with flanges 18 and 19 is also possible.

The first step in processing a pulley blank according to the invention is the partial collapse of the wall 11 of the blank 15. There are two or three methods for this partial crushing. One method (although not the preferred method) is U.S. Pat.
This is the expansion method by Zachiko). This method is not a preferred method because it requires special equipment, which must be attached to a spinning drawing machine specifically for processing this step and removed during other processing operations. Another method, which is also not preferred, is to simply apply axial pressure to the upper chuck 23, thereby causing the cylindrical upright wall to curve as shown at 112 in FIG. In this case, the wall portion is irregularly curved. The holding member 60 is not required during the process of partially crushing the wall portion 11 to an approximate shape as shown by reference numeral 112, but may be provided if necessary. As is clear to those skilled in the art, the fourth
Even after forming the flanges 18, 19 by the method shown in FIGS. a and 4b, the irregular curvature still occurs.

Figures 6a and 6b show the wall section 1 which changes to the above method.
A preferred method of partially collapsing 1 is shown.

In Figures 6a and 6b, a pair of rollers 3
1 and 32 rotate around bb. There are compression springs 33 between these rollers, separating them from each other. Each roller has a sloped portion 34;
There is a rounded projecting portion 35 and a curved portion 36,
This curved portion is closest to the other roller. When both rollers 31 and 32 are moved toward the wall 11, the pair of rollers move toward both the projecting portions 3.
5 are placed at positions apart from each other by springs 33 so that they abut against the cylindrical wall portion 11 at positions considerably apart from each other.

In the process of partially crushing the blank cylindrical wall by the method shown in FIGS. 6a and 6b, chucks 20,
23 and thus rotate the blank 15;
The rollers 31 and 32 are moved to come into contact with the cylindrical wall portion 11. When the rollers 31, 32 come into contact with the wall 11, the rotation of the blank 15 is transmitted, and as a natural result, the rollers 31, 32 also begin to rotate. As a matter of course, the overhanging portions 35 of the rollers 32, 32 are most in contact with the cylindrical wall portion 11 of the blank. Overhang part 3
5 comes into contact with the cylindrical wall 11, the rollers 32, 32 are moved in the direction of the axis a-a, and at the same time the upper chuck 23 is moved in the direction of the lower chuck 20. Due to this operation, the cylindrical wall portion 11 of the blank is curved, but in this case, as the upper chuck 23 moves toward the lower chuck 20, the spring 33 is compressed, so that the overhanging portion 35
tends to always remain in contact with the initial contact, so that the curvature of the wall 11 is advantageously controlled. In this way, the blank wall
As shown in Figure b, it curves along the curved surface portion 36 of the roller. The distance by which the rollers 31, 32 are approached to the axis a--a, the design of the contour of the curved portion 36, the distance by which the upper chuck 23 is moved, etc. will be apparent to those skilled in the art. Generally, roller 3
1 and 32 are preferably moved until their opposing surfaces finally come into contact with each other. If you do this,
As shown by reference numeral 37, no gap remains at the joint between the curved surfaces of both rollers, and therefore no sharp edges or burrs are formed. However, even if sharp edges or burrs occur, they are not harmful as they can be removed in subsequent processing steps. roller 3
After retracting the chucks 1 and 32, further controlled crushing can be achieved by moving the upper chuck 23 and lower chuck 20 even closer together to the required distance.

Reference numeral 113 in FIG. 6b shows the shape of the wall portion formed by the method shown in FIGS. 6a and 6b after the partial collapse. In this case, the shape of the collapsed wall will be somewhat more regular than the shape of the collapsed wall using the method shown in FIG.

In the subsequent steps, the wall has the shape 112 (Figure 5).
However, the method of the present invention is equally applicable to a wall having a shape 113 (FIG. 6b). Whichever method is used to collapse the wall, the final height of the wall after collapse h ₁
(Fig. 5) should be 25 to 75% of the original height h of the wall (Fig. 2). Before crushing, Figure 4a, Figure 4
If the flanges have already been formed in the manner shown in Figure b, the collapse height h ₁ also includes the heights of the flanges 18 and 19.

The height of the holder 60 is determined as shown in FIG. 5 and FIG.
Advantageously, the height is such that 0 and the base 10 of the blank are in contact.

After the wall is crushed into the shape 112 or 113, the present invention enters the steps shown in Figures 7a and 7b as the final step to make a pulley for a poly V belt, or a pulley for a flat belt with increased wall thickness. Steps 8a and 8b are entered as the steps for making the pulley.

Even if the steps shown in FIGS. 8a and 8b are carried out, if necessary, the step shown in FIG. 9 can be carried out subsequently to change the pulley to a poly V belt.

7a and 7b, one method of making pulleys for poly-V belts from crushed blanks having shapes 112 or 113 is described.
In Figure 7a, roller 40 rotates about axis dd parallel to axis a-a. The surface of the roller 40 is formed with spaced acute protrusions 41 to form V-shaped grooves 42. The number and shape of the protrusions 41 are the same as the number and shape of the protrusions of the poly V belt used in combination with this pulley. In the example of FIG. 7a, there are six protrusions 41 and 5.
There are grooves 42 at locations, the shape of which is the same as the profile used in conventional V-belts.

A transitional slope 43 is formed at the joint between the upper surface of the roller 40 and the working surface (V-groove surface). Similarly,
A transition slope 44 is formed at the junction of the lower surface of the roller and the working surface. The upper chuck 23 and the lower chuck 20 start rotating in the same direction at the same time, rotating the partially crushed blank. At this point, axis dd is advanced in the direction of axis a-a. When the working surface of roller 40 comes into contact with the blank, roller 4
0 also begins to rotate, and the bevel 43 joins the blank, pressing the wall portion 114 of the blank against the bevel 26 of the upper chuck 23 to form a flange. Similarly, ramp 44 presses portion 115 against ramp 25 of the lower chuck to form a lower flange.

These flanges have the same shape as the flanges 18, 19 formed by the method of Figure 4b. 4th b
If the processing shown in the figure has already been carried out and the flanges have already been formed, the slopes 43, 44 will simply fit into the already formed flanges, and if there is any deformation, some modification will be required.

The acute-angled protrusion 41 cuts and deforms the blank wall of the shape 112.

If the blank wall is not partially crushed, i.e. remains in the cylindrical wall 11 shown in FIG. 2, the sharp protrusion cuts deeply into the thin metal sheet of the wall. That will happen. At this time, if the metal sheet is relatively thin, that is, approximately
0.110 inch (approximately 2.89 mm) or less, and the depth from protrusion 41 to groove 42 is 0.125 inch (approximately 3.18 mm)
If so, the sharp protrusion 41 cuts completely or nearly cuts through the metal plate of the wall 11 before the metal material completely enters the groove 42, and thus the wall 11 strength is extremely reduced.

In accordance with the method of the present invention, the partial collapse of the feature 112 allows more metal material to be delivered to the working surface of the roller 40 than on a wall with a straight profile as in FIG. For this reason, even if the thin metal plate is 0.080 inches (approximately 2.03 mm) thick, it is possible to sufficiently fill a 0.125 inch (approximately 3.18 mm) groove with metal material while maintaining sufficient wall strength. .

Roller 40 advances toward axis a-a until groove 42 is completely filled with metal material. Figure 7b shows the final shape of the blank wall. As shown, there is a significant metal material thickness y between the tip of the overhang 41 and the inner surface 116 of the wall of the blank which bears against the outer surface 62 of the retainer 60. The inside of the groove 42 is completely filled with wall metal having a dimension x. Generally, metal material thin plates have a thickness of 0.070 to 0.130.
inch (approximately 1.78 to 3.30 mm), height h ₁ is 0.25 to 0.75 of height h, wall thickness + protrusion height (x in Figure 7b)
+y dimension) is approximately 1.5 to 2.5 of the thickness of the thin metal material plate.
You will get a pulley that is twice as large. The relative relationship between the dimension y and the dimension x is naturally determined by the shape and number of the protrusions 41 or the distance at which the roller 40 approaches the outer surface 62. As a condition for obtaining a high strength pulley for an automobile, the limit of the approach of roller 40 to outer surface 62 is such that the minimum wall thickness y is 0.040 inches (approximately 1.02 mm). Naturally, if the required pulley strength is low, the minimum thickness can be made smaller.

During the processing shown in FIG. 7b, the role of the holder 60 is very important. The outer surface 62 of the retainer 60 has a shape 112
This serves to ensure that the entire groove 42 is filled in the metal material of the blank wall.

After the rollers 40 have reached the position shown in Figure 7b, they are retracted to remove the fully formed pulley for the poly-V belt.

The pulley thus formed has flanges 18, 19 which give the pulley considerable dimensional stability.
and a series of grooves (roller 40) that engage the poly V-belt.
There is a protrusion 41 and a depressed groove 42).

Figures 8a and 8b show another example of a device configuration, forming a pulley with a flat surface. 8th
The roller 70 in figure a rotates about an axis e-e parallel to axis a-a. This roller has a flat surface 71 and two inclined parts 72, 73. The inclined portion 72 and the flat surface 71 are joined on the upper side of the roller, while the inclined portion 73 and the flat surface 72 are joined on the lower side of the roller. The width of the surface 71 is made slightly smaller than the width of the outer surface 62 of the holder 60. The slopes of the slopes 72 and 73 are the same as those of the slopes 72 and 73 for forming flanges.
Surfaces 26 and 25 are the objects of mutual interaction, respectively.
It is determined in relation to the slope of

The upper chuck 23 and the lower chuck 20 are simultaneously rotated in the same direction with the blank attached.
As shown in FIG. 8a, the roller 70 is opposed to the blank and the axis ee is advanced toward the axis aa. The flat surface 71 contacts the partially collapsed wall of the shape 112 and presses it further against the outer surface 62 of the holder 60 . At the same time, the inclined portion 72 of the roller 70,
73 squeezes a portion of the blank wall into the surface 26 of the upper chuck 23 and the surface 25 of the lower chuck 20, respectively, to form flanges. Because the blank wall is partially bulged or collapsed, there is more metal material in the flat surface formation than would be required to form a flat surface of the same thickness as the base metal material thickness. Therefore, the proximity of roller 70 to outer surface 62 forms a thick, smooth wall 111 toward this flat outer surface 62 . roller 7
The advance of 0 stops at a predetermined position.
This stopping position is determined in relation to the curvature of the shape 112 or the amount of collapse when forming the partially collapsed wall so that the newly formed wall portion 111 has a required thickness.

Generally, the thickness of the wall portion 111 is somewhat thicker than the thickness of the thin metal plate forming the base portion 10 (excluding other reinforcing members or the hub), and is approximately 1.25 to 2 times the thickness of the base portion 10. Preferably it is about 1.33 to 1.5 times. As the roller 70 is further advanced toward axis a-a, excess metal is squeezed out of the roller edges and the wall 111 becomes thinner, but this condition is undesirable and is not intended for purposes of this invention. do not have. It will be appreciated that with respect to the techniques disclosed herein, one skilled in the art can readily determine the amount of collapse necessary to form a wall 111 suitable for the required wall thickness.

If the flanges 18, 19 are already formed as shown in FIGS. 4a and 4b, the surfaces 72,
73 does not function to form a flange, but simply joins to the existing flanges 18 and 19 to prevent material metal from flowing out between surfaces 62 and 71 forming the newly thickened wall 111. do.

After the state shown in FIG.
Take it out from between.

In this way, a pulley with a smooth and strong wall 111 for a flat belt is formed. Pulley flanges 18, 19 serve to hold the flat belt in place.

Originally, the methods shown in Figs. 7a, b and 8a, b are methods for forming pulleys with flanges 18, 19, and generally it is preferable to have these flanges, and these flanges are according to the present invention. One advantage of the present invention is that it serves to prevent the V-belt from slipping off the pulley. However, if desired, the flanges 18, 19 may be removed by techniques known in the art for clipping unwanted flanges or burrs from spinning throttle pulleys or other conventional methods. Therefore, although these flanges constitute a desirable part of the present invention, pulleys without flanges can also be manufactured by the process of the present invention.

If necessary, after forming the wall 111, the pulley blanks are attached to the upper chuck 23 and the lower chuck 20.
Instead of taking it out from between the rollers 40 and 40 as shown in FIG. 9 following the processing shown in FIGS. 8a and 8b,
It can also be processed by The roller 40 is
The wall portion is approached in the same manner as explained in Sections 7a and 7b, but in this case, the roller 40
The active surface engages not a curved surface like shape 112 but an oblique surface 111 of increased thickness. As can be seen by comparing Figure 9 and Figure 7b, Figure 7a
The same results are obtained as seen in the processing plant of FIG. 7b.

In the above disclosure, two chucks 20,
23 is rotated together with the blank 15 in the same direction and at the same speed, various rollers are brought into contact with the blank wall. In this case, a single or plural rollers (for example, roller 4
0 or roller 70) is free to rotate but is not driven. When the roller contacts the rotating blank wall, its rotation drives it at the same rotational speed as the blank.

It is also within the scope of the present invention to not drive the chucks 20, 23 freely in rotation, but instead to drive rollers that approach the blank wall. Although this is not a preferred method, it is also possible to connect both the roller and the chucks 20 and 23 to a drive source so that they are driven and rotated. The direction of rotation should be such that the roller and blank move in the same direction at the point of contact, but the contact points between the two do not have to be exactly the same, and depending on the situation, the contact point between the blank and the roller may move in the same direction. Although it is possible to obtain good results when the two move in opposite directions, this is generally not the preferred method. Examples of pulley fabrication according to the present disclosure are listed.

Example 1: A 6.6 inch diameter (approximately 167 cm
mm), height h = 2.0 inches (approximately 50.8 mm), and a blank having the shape shown in Figure 2 is drawn and formed. By the method shown in Figure 5
Partially crush until h ₁ = 1.0 inch (approximately 25.4 mm). Number of grooves: 6, groove pitch: 0.140 inch (approximately 2.64
Using a roller 40 with a groove 42 having a depth of 0.140 inches (about 2.64 mm), processing is performed according to the steps shown in FIGS. 7a and 7b. Tip of protrusion 41 and outer surface 62
Roller 40 is advanced toward axis a-a until the distance between the two ends is 0.050 inches (approximately 1.27 mm). In this way, a grooved pulley having two flanges (18 and 19 in the figure) with an outer diameter of about 6.6 inches (about 167 mm) and a pitch circle diameter of 6 inches (about 152 mm) for the V-belt support is obtained. Each groove measures 0.140 inches deep (approx.
2.64 mm), and the distance between the valley of the V-groove and the inner peripheral surface of the blank (y dimension in Figure 7b) is 0.050 inch (approximately 1.27 mm).
mm). The variation in depth between the six grooves is less than 0.002 inch (approximately 0.05 mm) and is not a problem. Dimensions around the pulley diameter are substantially constant.

Example 2: A blank having the same shape as the blank of Example 1 is preformed from a sheet metal 0.080 inch (approximately 2.03 mm) thick. The blank is partially crushed in the process shown in Figure 5, and the height h ₁ = 1.0 inches (25.4 mm).
Make it. The method of FIGS. 8a and 8b is carried out.
The distance between the surface 71 and the surface 62 of the roller 70 is 0.120.
3.12 mm (approx. 3.12 mm). Roller 70 is retracted and the blank is removed from between chucks 20 and 23. V-belt bearing diameter: 6.0 inches (approximately 152mm), V-belt bearing thickness:
Obtain a 0.120 inch smooth cylindrical V-belt bearing pulley.

Example 3: The pulley obtained by the method of Example 2 is subjected to the steps of FIG. 9 and its related steps. The roller 40 is attached to the protrusion 4
The distance between the tip of 1 and surface 62 is 0.050 inch (approx.
1.27mm). The roller 40 is moved back and the blank is taken out from between the chucks 20 and 23. A pulley similar to the poly V belt pulley formed in Example 1 is obtained.

The pulleys of Examples 1, 2, and 3 all showed high strength against forces that tend to deform the pulleys, and were determined to be suitable for use in automobiles, and in fact, in large trucks.

The present invention is not limited to the roller structure described and illustrated herein, nor is it limited to the exact pulley shape shown, and other configurations of the roller shape are within the scope of the present invention. It is clear that various changes can be made.

[Brief explanation of the drawing]

1 is a diagram showing a sheet of metal for forming a pulley blank; FIG. 2 is a cross-sectional view of one form of a pulley blank formed from the sheet metal of FIG. 1; FIG. 2a and FIG. Fig. 2b is a sectional view of another shape of the base of the pulley blank, Fig. 3 is a sectional view of the pulley blank of Fig. 2 attached to a spinning drawing device, and Fig. 4a is a sectional view of the pulley blank of Fig. 2. Figure 4b is a partial cross-sectional view of the same blank, showing the flange forming method that may be carried out if necessary before partially crushing the blank, and Figure 5 is a partial cross-sectional view of the blank of Figure 2. 6a and 6b are partial cross-sectional views of the blank of FIG. 2 showing successive steps of another method of partially crushing the blank, and FIGS. 7a and 6b are partial cross-sectional views of the blank of FIG. Figures 8a and 7b show the successive steps of forming a V-groove in a partially crushed blank, and Figures 8a and 8b show the wall thickness of a partially crushed blank without forming a V-groove. 9 shows a method of forming a V-groove in the blank after the step of FIG. 8, showing the successive steps of increasing the thickness. 1... Metal thin plate, 10... Circular base, 11...
Cylindrical wall portion, 15...Pulley blank, 20,
23...chuck, 31, 32, 40, 50...
Roller, 41... Projection, 42... Groove, 60...
...Block, 112, 113...Wall section.

Claims (1)

[Scope of Claims] 1. First, the axial length of the cylindrical portion 11 is larger than the axial length of the completed cylindrical portion with the V-shaped groove formed on the outside of the cylindrical portion, The cylindrical portion 11 and the circular base portion 10 have substantially uniform overall thickness.
A substantially pot-shaped metal plate blank 15 consisting of
Next, the cross-sectional shape of the axis passing surface of the cylindrical portion is corrugated to the extent that the metal plates do not overlap and come into contact with each other when pressed radially inward in the subsequent process. , the cylindrical portion 11 of the blank 15
a step of shortening the length of the cylindrical portion 11 in the axial direction by partially crushing the cylindrical portion 11 in the axial direction; Pressing the outer peripheral surface of the support member radially inward with a roll to form the inner peripheral surface of the cylindrical part into a flat cylindrical surface and roll-forming a V-shaped groove on the outer peripheral surface. A method of manufacturing a V-pulley. 2. The manufacturing method according to claim 1, wherein the last step of the partially crushing step is performed without any support from the outside of the cylindrical portion. 3. The method according to claim 1 or 2, wherein both the inner and outer surfaces of the cylindrical portion are initially straight in the axial direction, and then a V-shaped groove is roll-formed on the outer surface of the cylindrical portion. Production method. 4. The final thickness of the cylindrical portion is 1.25 to 2 times the predetermined thickness of the substantially pot-shaped blank formed in advance.
The manufacturing method according to any one of Items 1 to 3. 5. The manufacturing method according to claim 4, wherein the thickness ratio is 1.33 to 1.5 times. 6. The cylindrical part 11 has a substantially uniform thickness, and the axial length of the cylindrical part 11 is greater than the axial length of a completed cylindrical part with a V-shaped groove formed on the outside of the cylindrical part. A substantially pot-shaped metal plate blank 15 consisting of a circular base 10 and a circular base 10 is used, and the cross-sectional shape of the cylindrical portion at the axial center passing plane is adjusted so that it is pressed radially inward in the subsequent process. The cylindrical portion 11 of the blank 15 is partially crushed in the axial direction to shorten the axial length of the cylindrical portion 11 so that the metal plates overlap and do not touch each other. A device used in a method for manufacturing a multi-groove V pulley in which a V-shaped groove is roll-formed by pressing the partially crushed corrugated portion radially inward, the device comprising: a concentric groove holding the preformed blank 15; a chuck 20 on one side, a chuck 23 on the other side concentric with the chuck on one side, a mechanism for moving one of these chucks in the axial direction toward the other side, and a mechanism suitable for moving toward the side of the blank and a chuck 23 on the other side concentric with the chuck on the one side; A structure in which the axial length of the cylindrical portion 11 is shortened to form the corrugated portion by means of rollers 31 and 32 having two separated annular regions 35 that protrude in the direction of the cylindrical portion and come into contact with the cylindrical portion. , a cylindrical support member 60 disposed concentrically inside the cylindrical portion, and a roll 40 that presses the outer periphery of the support member radially inward, the inner peripheral surface of the cylindrical portion being a flat cylindrical surface. A multi-groove V structure comprising:
Pulley manufacturing equipment. 7. The manufacturing apparatus according to claim 6, wherein the rollers are comprised of a pair of rollers 31 and 32, which are movable in the axial direction toward each other under spring bias.