JP2004508197A - Method of spinning a pulley from a tubular blank - Google Patents

Abstract

The present invention comprises a method of spinning a pulley using a tubular blank. The tubular blank is placed on a spinning machine mandrill. The hub is formed by spinning down, or inward, one end of the tubular blank, during which the other end is spun to form either a pulley or a sprocket. Is maintained in a cup shape. According to this process, the metal naturally thickens at the hub by retaining a constant volume of the metal during the spinning process, while reducing the diameter of the tube.

Description

[0001]
(Field of the Invention)
The present invention relates to a power transmission pulley, and more particularly to a method of spinning a pulley from a tubular blank.
[0002]
(Background of the Invention)
Pulleys and sprockets are widely known and used as means for transmitting power between shafts. Power transmission pulleys are made in several ways. The metal plate type is manufactured by spinning molding or a cam mold. In this way, the belt shape is formed by radial movement of the mold with respect to the blank.
[0003]
Representative of this technique is U.S. Pat. No. 4,840,607 (1989) to Hitchcock et al. Which describes a grooved area along the sides of the blank. Discloses a spin-formed multiple V-belt pulley formed using a "can-shaped" blank formed by pressing against a material. The invention could not only provide flexibility in the thickness of the hub region, but was not a single step.
[0004]
The prior art also relies on can-shaped blanks having a suitable pre-formed thickness for the web. The pulley is simply pressed into the presence of the preformed web thickness. Furthermore, preforming requires a forming step, which is performed before the spinning forming step, and is expensive to finish the part. Other conventional pulley technologies rely on horizontal forming, which, for example, as found in US Pat. No. 5,987,952, is the most advantageous of sheet metal for the described application. It does not bring about any plastic flow. The process relies on spinning the metal on the surface of the circular blank from the outside to the center until the brought metal is formed around a central pillar to form the hub. This process requires a certain diameter for the part and a blank that allows the required metal volume to be assembled. For small diameter parts, i.e. very long and thick hubs, there is not enough surface area to gather the required metal volume.
[0005]
What is needed is a method of spinning a pulley using a tubular blank. What is needed is a method of spinning a pulley from a tubular blank by gathering metal inward toward the hub end of the tubular blank. What is needed is a method of spinning a pulley using a tubular blank that provides more inward gathering of the gathered metal. The present invention meets these needs.
[0006]
(Summary of the Invention)
A primary feature of the present invention is to provide a method for spinning a pulley using a tubular blank.
[0007]
Another feature of the present invention is to provide a method for spinning a pulley from a tubular blank by gathering metal inwardly toward the hub end of the tubular blank.
[0008]
Another feature of the present invention is to provide a method of spinning a pulley from a tubular blank that provides more inward gathering of the gathered metal.
[0009]
Other features of the present invention will be apparent from and elucidated with the following description of the invention and the accompanying drawings.
[0010]
The present invention includes a method of spinning a pulley using a tubular blank. The tubular blank is placed on a spinning machine mandrel. The hub is formed by spinning down, or inward, one end of the tubular blank, during which the other end is spun to form either a pulley or a sprocket. Is maintained in a cup shape. According to this process, the metal naturally thickens at the hub by holding a constant volume of the metal during the spinning process, while reducing the diameter of the tube. The required shape is then formed on the rim of the pulley.
[0011]
(Detailed description of preferred embodiments)
FIG. 1 shows a cross-sectional view of a tubular blank. The tubular member or blank comprises a cut piece of tube, a pipe or a deep drawn cylindrical cup with the bottom removed. The tubular blank has a length L, a diameter D ₁ , and a thickness T ₁ .
[0012]
FIG. 2 shows a cross-sectional view of a tubular blank on a mandrel. The process begins by placing a tubular blank B on a suitably sized mandrel 10. During the diameter D ₁ is the blank and the mandrel, there may be white little clamping, also blanks, by means known in the art, it may be secured to the mandrel.
[0013]
Then, the mandrel and the blank are rotated by the head stock 10. The forming roller 12 is movable along the radial and axial directions of the device, as is known in the art, to properly shape the blank. To form the pulley, the mandrel rotates. The forming roller is moved to contact the side of the tubular blank at a location selected by the operator. As the forming rollers move inward, the metal shrinks as the diameter at the hub location around the tailstock decreases steadily. In this step, because the volume of the metal does not change, the diameter decreases, so that some of the ends of the shaft become thicker as the forming rollers move inward.
[0014]
FIG. 3 shows a cross-sectional view of a forming roller when forming a tubular blank. Forming roller 12 is shown to move toward the center of the radial M _1. When forming roller is moved inwardly, metal provided by, the front side of the forming rollers, whereby the hub 14 diameter D ₂ of the hub 14 is progressively reduced is molded. As the forming rollers continue to move inward, the metal is pulled and the hub is formed around tailstock 11. The forming roller 12 may follow the contour 15 of the mandrel 10 to give the finished part a suitable shape. It may taper the profile of the web requested by the user, resulting in a taper in thickness from the rim toward the hub region. The trajectory of the forming roller may likewise be adjusted about an axis to move inward to change the thickness of the web 17. In this manner, the thickness of the web may be tapered, varied, or kept constant, depending on the needs of the user. The web 17 may be similarly rotated and formed into a concave shape or a combined concave / convex shape for further strength.
[0015]
FIG. 4 shows a cross-sectional view of a fully formed pulley. The inner diameter D ₃ of the hub is determined by the width of the tailstock 11. Metals were received at the hub 14 has a very large the _second thickness T ₂ than the initial thickness T _1. Then, in order to finish the hub, the roller 13 for finishing to be moved in M ₂ direction is used to mold the final shape of the hub 14. The final shape, ie the shape of the hub 14, is created by the contour of the finishing rollers. The finishing roller 13 may have any user-required profile known in the art. The thickness of the hub may be maintained at _{T 2,} or, in order to mold the puller (puller), may be reduced to _{T 3.}
[0016]
Once the part is molded, it is removed from the mandrel for molding of the final shape of the rim or belt bearing surface 16 as required by the user. A shaping roller (not shown) is used to shape the surface of the belt bearing. The surface of the belt bearing may be the shape of a V-belt, a multi-ribbed shape, or any other shape known in metal forming means.
[0017]
While one form of the invention has been described, it will be obvious to those skilled in the art that modifications may be made in relation to the configuration of the various parts without departing from the spirit and scope of the invention.
[Brief description of the drawings]
FIG.
1 shows a cross-sectional view of a tubular blank.
FIG. 2
FIG. 4 shows a cross-sectional view of a tubular blank on a mandrel.
FIG. 3
FIG. 4 shows a cross-sectional view of a forming roller when forming a tubular blank.
FIG. 4
FIG. 4 shows a cross-sectional view of a fully formed pulley.

Claims (4)

Forming a tubular member having a length, a tubular member diameter, and an initial thickness,
Using the mandrel, rotate the tubular member,
Pressing the forming roller against the side surface of the tubular member, moving the forming roller radially inward against the tubular member,
Reducing the diameter of the tubular member along a portion of its length;
At the hub position, the dislodged metal is gathered inward around the tailstock,
Finish the movement of the forming roller,
Retract the forming roller,
A method for spinning a pulley, comprising steps. The method of spinning a pulley of claim 1, further comprising terminating the movement of the forming roller when the hub has a thickness greater than an initial thickness. 3. The method of spinning a pulley of claim 2, further comprising the step of pressing a finishing roller against the hub to shape the shape and thickness of the hub. Pressing a shaping roller against the belt receiving surface of the tubular member,
4. The method of spinning a pulley of claim 3 further comprising the step of moving a shaping roller to form a profile on the belt receiving surface.