JPH11123485A - Formation of boss part in metallic disk being pulley stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and integratedly forming a thick boss part on a center part of a metallic disk being is a pulley stock. SOLUTION: A center part of a metallic disk 1 which is a pulley stock is drawn in a cup shape in the thickness direction through pressing or spinning to form a cup-shaped part 12, a bottom part of the cup-shaped part 12 is cut to open, a columnar press inner die 3a of the outside diameter corresponding to the inside diameter of the cup-shaped part 12 is inserted in the cup-shaped part 12 whose bottom part is open, a press outer die 8a having a hole of the inside diameter larger than the outside diameter of the cup-shaped part 12 is concentrically fitted to an outer circumference of the cup-shaped part 12, an opening end of the bottom part of the cup-shaped part 12 is pressed to increase the thickness of the cup-shaped part 12 and to form a boss part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing a pulley by forming a belt hanging portion by rolling or other methods on the outer periphery of a single metal disk. The present invention relates to a method for integrally forming a boss.

[0002]

2. Description of the Related Art Pulleys having a belt hanging portion formed by rolling or other methods on the outer periphery of a single metal disk are widely used because of their light weight and ease of manufacture. As means for providing a boss on the pulley made of one metal disk, a small hole is formed in the center of the metal disk, and a punch having a diameter larger than this hole is press-fitted into this hole to form the metal disk. A burring method in which a tubular portion is formed at the center portion and the boss portion is used, and a hole is formed at the center of the metal disk, and a boss portion separately formed at the center of the metal disk is fixed by welding or the like. There is a way.

[0003]

According to the burring method described above, although the manufacturing is easy, the boss portion cannot be made thick, and the pulley main body and the boss portion, which require the most strength in the pulley, are required. The strength of the base is weak, and it is not suitable for pulleys that have a large load here. In order to increase the thickness of the boss portion manufactured by such a method, it is conceivable to increase the thickness of the metal disk serving as the base material, but increasing the thickness of the metal disk is intended for purposes such as weight reduction. On the other hand, there is a problem that the material is wasted and the cost is increased.

[0004] For this reason, as a boss portion of a pulley to which a large load is applied, generally, a boss portion having a required thickness is separately formed, and this boss portion is fixed to a central portion of a metal disk by welding or the like. Although this method can be used to make the boss part as thick as necessary, the cost is high because the boss part is separately manufactured, and the boss part is removed so that the boss part does not fall off the metal disk. It is necessary to pay sufficient attention to fixing by welding or the like, and it is necessary to pay sufficient attention to the center accuracy between the metal disk and the boss portion, so that there is a problem that manufacturing is troublesome.

An object of the present invention is to provide a method for easily forming a thick boss portion integrally at the center of a metal disk serving as a pulley material.

[0006]

According to the present invention, there is provided a method of forming a boss portion of a metal disk serving as a pulley material, wherein a central portion of the metal disk serving as a pulley material is cup-shaped in a plate thickness direction by pressing or spinning. A cup-shaped part is formed by squeezing the cup-shaped part, the bottom of the cup-shaped part is cut off and opened, and a cylindrical press inner die having an outer diameter corresponding to the inner diameter of the cup-shaped part is inserted into the cup-shaped part having the opened bottom. At the same time, a press outer die having a hole with an inner diameter larger than the outer diameter of the cup-shaped portion is fitted concentrically on the outer periphery of the cup-shaped portion, and the cup-shaped portion is pressed by pressing the bottom open end of the cup-shaped portion. It is characterized in that the boss portion is made thicker.

According to this method, a thick boss is integrally formed at the center of a metal disk serving as a pulley material.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 11 show steps of an embodiment of the present invention.

First, a metal plate is punched out by press working or the like to form a metal disk 1, and a lower cylindrical press inner die 3 having a lower portion supported by a base plate 2;
And a lower die 6 composed of a receiving die 5 slidably fitted on the outer periphery of the cylindrical press and urged upward by a spring 4, and a cylindrical press inner die 3 located coaxially with the cylindrical press inner die 3. A press outer die 8 having a press hole 7 having an inner diameter forming a gap corresponding to the thickness of the metal disk 1 and fitting to the outer periphery of the cylindrical press inner die 3; Pressing die 1 slidably fitted in press hole 7 and urged downward by spring 9
The metal disk 1 is set between the upper die 11 and the upper die 11 (FIG. 1).

Next, the upper mold 1 is pressed by a press machine (not shown).
1 is pressed to the lower die 6 side, and the outer die 8 of the upper die 11 is pressed.
Is fitted to the outer periphery of the cylindrical press inner die 3 of the lower die 6, thereby squeezing the center of the metal disk 1 into a cup shape in the plate thickness direction to form a cup-shaped portion 12 (FIG. 2).

The squeezing of the cup-shaped portion 12 is performed by sequentially changing the diameter of the lower cylindrical press inner die 3 to a smaller one.
The squeezed cup-shaped portion 12 is squeezed a plurality of times by changing the receiving die 5 and the press outer die 8 and the presser die 10 of the upper die 11, and gradually reducing the diameter of the cup-shaped portion 12 and increasing it. Thus, a cup-shaped portion 12 having a required diameter and length is formed (FIGS. 2, 3, 4, and 5).

Next, the punch 13 set on the lower mold 6 is inserted into the cup-shaped part 12, and the die 14 set on the upper mold 11 is pushed in from the bottom side of the cup-shaped part 12,
The bottom of the cup-shaped portion 12 is punched out and cut open (FIG. 6).

Next, a cylindrical press inner die 3a having an outer diameter corresponding to the inner diameter of the cup-shaped portion 12 having the bottom opened and inserted into the cup-shaped portion 12 is provided on the base plate 2 of the lower die 6. A support surface 15 for supporting the lower surface of the metal disk 1 having the cup-shaped portion 12 formed at the center thereof and abutting against the outer peripheral end of the metal disk 1 to restrict the radial expansion of the metal disk 1
The upper die 11 is provided with a hole 16 having a diameter larger than the outer diameter of the cup-shaped part 12, and the lower die 8a presses the upper surface of the metal disk 1 on the lower surface. Then, a cylindrical press body 17 having an outer diameter corresponding to the inner diameter of the hole 16 of the press outer die 8a and an inner diameter corresponding to the outer diameter of the cylindrical press inner die 3a is set.

Then, while inserting the cylindrical press inner die 3a of the lower die 6 into the cup-shaped portion 12, the metal disk 1
Is supported on the support surface 15 of the receiving die 5a, and then the upper die 1
The hole 16 of the press outer die 8a is inserted into the cylindrical press inner die 3
a is fitted concentrically to the outer periphery of the cup-shaped portion 12 into which the inserted metal plate 1 is inserted, and the lower surface thereof presses the upper surface of the metal disk 1. As a result, the outer peripheral surface of the cup-shaped portion 12 and the hole 16
A gap will be formed between the inner peripheral surface and the inner peripheral surface. When the cylindrical press body 17 is lowered from this state, the cylindrical press body 17 fits around the outer periphery of the cylindrical press inner die 3a,
The bottom opening end of the cup-shaped portion 12 is pressed. At this time, the upper and lower surfaces of the metal disk 1 have a receiving die 5a and a press outer die 8.
a, and since the metal disk 1 is restricted from spreading in the radial direction by the support surface 15 of the receiving die 5a,
The cup-shaped part 12 pressed by the cylindrical press body 17 is
It escapes into the gap between the outer peripheral surface of the cup-shaped portion 12 and the inner peripheral surface of the hole 16 of the outer press die 8a, and becomes thicker (FIG. 7).

In this manner, the thick boss portion 18 is integrally formed at the center of the metal disk 1 serving as the pulley material. The metal disk 1 on which the boss 18 is formed in this manner
Is formed on the outer periphery of the belt. The means for forming the belt hanging portion is not particularly limited, and is formed by a known means.

FIGS. 8 to 11 show an example of a process for forming a poly-V groove on the outer periphery of the metal disk 1 on which the boss portion 18 is formed. First, the metal disk 1 is clamped on both sides by clampers 19 and 20. FIG. Clamp from This clamper 19, 20
The relief portions 21 and 22 allow the outer peripheral portion of the metal disk 1 to be extruded to both sides by a roller die described later to form a cylindrical portion, and contact the inner peripheral surface of the cylindrical portion with this. Support surfaces 23 and 24 for supporting are formed.

The roller die 25 is pressed against the outer peripheral end surface of the metal disk 1 clamped by the clampers 19 and 20 in the axial direction and rotated. As a result, cylindrical portions 26 and 27 are formed symmetrically on both sides of the metal disc 1 in the escape portions 21 and 22 on the outer peripheral portion of the metal disc 1 (FIG. 9). And the inner peripheral surfaces of the cylindrical portions 26 and 27 are clampers 19 and 20.
The cylindrical portions 26 and 27 are pressed by the roller die 25 and the support surfaces 23 and 24,
The rim 28 is formed on the outer circumference of the metal disk 1 by the cylindrical portions 26 and 27 (FIG. 10).

Next, a V-groove forming roller die 30 having a plurality of V-shaped ridges 29 on the outer circumference is pressed against a rim 28 formed on the outer circumference of the metal disk 1 and rotated. As a result, a plurality of V grooves 31 are formed in the rim 28, and a poly V pulley is completed (FIG. 11).

[0019]

As described above, according to the present invention, a thick boss portion can be easily formed integrally with the center of a metal disk serving as a pulley material, and a metal circle serving as a pulley material can be formed. The thickness of the boss can be increased without increasing the thickness of the plate, so that the weight can be reduced, and further, the cost can be reduced because the manufacturing is easy.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a step of carrying out the present invention.

FIG. 2 is an explanatory view showing a step of carrying out the present invention.

FIG. 3 is an explanatory view showing a step of carrying out the present invention.

FIG. 4 is an explanatory view showing a step of carrying out the present invention.

FIG. 5 is an explanatory view showing a step of carrying out the present invention.

FIG. 6 is an explanatory view showing a step of carrying out the present invention.

FIG. 7 is an explanatory view showing a step of carrying out the present invention.

FIG. 8 is an explanatory view showing a step of carrying out the present invention.

FIG. 9 is an explanatory view showing the steps of the embodiment of the present invention.

FIG. 10 is an explanatory view showing a step of carrying out the present invention.

FIG. 11 is an explanatory view showing a step of carrying out the present invention.

[Explanation of symbols]

 Reference Signs List 1 metal disk 2 base plate 3, 3a cylindrical press inner die 4 spring 5, 5a receiving die 6 lower die 7 press hole 8, 8a press outer die 9 spring 10 holding die 11 upper die 12 cup-shaped part 13 punch 14 die die 15 Support Surface 16 Hole 17 Cylindrical Press Body 18 Boss 19,20 Clamper 21,22 Escape 23,24 Support Surface 25 Roller Dies 26,27 Cylindrical Part 28 Rim 29 V-mount 30 V-groove forming roller die

Claims (1)

[Claims] 1. A central portion of a metal disk serving as a pulley material is squeezed into a cup shape in a thickness direction by pressing or spinning to form a cup-shaped portion, and a bottom portion of the cup-shaped portion is cut off and opened. A cylindrical press inner die having an outer diameter corresponding to the inner diameter of the cup-shaped portion is inserted into the cup-shaped portion having an open bottom, and a hole having an inner diameter larger than the outer diameter of the cup-shaped portion is provided on the outer periphery of the cup-shaped portion. A boss portion of a metal disk serving as a pulley material, characterized in that a press outer die having concentricity is fitted concentrically, and the bottom opening end of the cup-shaped portion is pressed to thicken the cup-shaped portion to form a boss portion. Forming method. Method.