JPH0914398A - Ring gear and its manufacture - Google Patents

Abstract

PURPOSE: To manufacture a ring gear of necessary precision at low cost by forming a tooth form by a die having a tooth form to form a tooth form to be molded on one surface of a belt type metallic material having specified width, winding this belt type metallic material in a circular shape and welding its abutted end. CONSTITUTION: A die having a tooth form to mold tooth forms 2,2... as a ring gear to manufacture is installed on a press machine and pressure molded on one surface of a sectionally square belt type metallic material. Thereafter, the belt type metallic material on which the tooth form 2 is formed is wound in an annulus shape with the tooth form 2 outside in the case of an external tooth ring gear and its abutted ends 6a, 6a are connected by welding 7. Thereafter, a material 6' made in an annulus shape is stored in a mold for finishing having a tooth form for formal finishing on an inner peripheral surface, a mandrel is press fit in an inner periphery of the annulus material 6', the tooth form 2 of the annulus material 6' is press fit in a tooth form for finishing of the mold for finishing and the tooth form 2 is finished in a normal shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring gear and its manufacturing method.

[0002]

2. Description of the Related Art Ring gears used for various purposes often have a relatively large diameter, and the thickness of the ring portion is often relatively thin. Manufacturing of such a ring gear is performed by forming a tooth profile by cutting using a machine tool such as a bob machine and a gear cutting machine as in the conventional general gear. This is the same for the external gear and the internal gear.

[0003]

Therefore, particularly in the case of a large-diameter ring gear, the number of teeth is large, and it takes a great deal of labor to manufacture a ring gear by cutting a tooth profile using a machine tool as in the conventional case. However, there was a problem that the cost would be extremely high. Moreover, even a ring gear that does not require high precision has excessive precision, which is not suitable for the actual situation.

In view of this, it is an object of the present invention to provide a ring gear and a method for manufacturing the ring gear, in which the tooth profile of the gear can be formed without cutting and a ring gear with a required accuracy can be manufactured at low cost.

[0005]

As a means for solving the problems of the above-mentioned conventional techniques, the present invention provides a tooth mold for forming a tooth profile to be formed on one surface of a strip-shaped metal material having a predetermined width. A tooth profile is formed by a pressing die having, and a ring gear formed by winding this band-shaped metal material in a circular shape and welding its abutting ends, and a tooth profile to be formed on one surface of the band-shaped metal material having a predetermined width. A step of pressing a tooth profile with a pressing die having a tooth profile for forming, a step of winding a band-shaped metal material on which the tooth profile is formed into an annular shape, a step of welding its abutting end, and the annular shape The method of manufacturing a gear, comprising the steps of: storing the formed material in a finishing die around which a regular finishing tooth die is provided, and press-fitting the tooth profile formed on the material into the finishing tooth die to finish-form. It is in.

[0006]

[Function] A ring gear having a tooth row on the outer peripheral surface (or inner peripheral surface) is formed by winding a band-shaped metal material having a tooth profile row formed by pressing on one surface into an annular shape and welding the abutting ends thereof. Put this in a finishing die, and in the case of an external tooth ring gear, press-fit the inner circumference of the ring gear to the finishing tooth die with a mandrel etc. and finish-mold it. By fitting and pressurizing the outer periphery of the ring gear, finish molding is performed, and the ring gear is manufactured by these.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

A stamping die 4 having a toothing die 3 for molding tooth shapes 2, 2 ... As a ring gear 1 (FIG. 6) to be manufactured is used, and the pressing die 4 is mounted on a press machine 5 as shown in FIG. For example, a tooth row is formed on one surface of the material 6 by pressure forming on one surface of the strip-shaped metal material 6 having a rectangular cross section. In this case, as shown in FIGS. 1A to 1C, the strip-shaped metal material 6
Has substantially the same length as the die 4 in the length direction of the die 4, and has a width M
The width of the die 4 is approximately ½ of the width of the die 4, as shown in FIG.
As shown in (C), the strip-shaped metal material 6 is gradually pressed and the intermediate portion in the up-down direction bulges outward (FIG. 2B), and the meat of the strip-shaped metal material 6 is the width M of the die 4. Gradually filled in the direction,
At the final point in time, as shown in FIG. 2C, all of the pressing die 4 in the width M direction is filled to form the tooth profile 2. The width and the thickness of the band-shaped metal material 6 can be determined by backcalculating from the dimensions of the ring gear 1 to be molded.

When the band-shaped metal material 6 is compressed and the tooth profile 2 is formed by press-fitting the tooth mold 3 of the pressing die 4, a part of the meat is formed on the band-shaped metal material 6 at both ends of the tooth bottom of the tooth profile 2. The excess meat 2a, 2a is projected to the outside, but this is removed by grinding or the like.

Next, in the case of an external toothed ring gear, the belt-shaped metal material 6 having the tooth profile 2 formed therein is annularly wound with the tooth profile 2 as the outer side, and the abutting ends 6a, 6a thereof are joined by welding 7.

After that, as shown in a cross section of an example in FIG. 5, the above-mentioned annular material 6'is housed in a finishing die 9 having a regular finishing tooth die 8 on its inner peripheral surface, and the annular material is The mandrel 10 is press-fitted onto the inner circumference of the 6'to force the tooth profile 2 of the annular material 6'to be press-fitted into the finishing tooth mold 8 of the finishing die 9 to form the tooth profile 2.
Is finished in a regular shape. When the annular material 6'is taken out from the finishing die 9 in this manner, the ring gear 1 having external teeth can be obtained.

In the case of a ring gear having internal teeth, it is possible to finish by using a finishing die having a regular finishing tooth die on the outer peripheral surface and pressing the outer periphery of the annular material 6 '.

S45C or the like is used as the material of the ring gear, and carbon steel of this type is preferable because the amount of deformation is small even if it is carburized and quenched after forming.

[0014]

As described above, according to the present invention, a tooth profile is formed on one surface of a strip-shaped metal material having a predetermined width by a pressing die, the material is wound into an annular shape, and its butt ends are welded. Since it becomes a ring gear by doing so, it can be obtained at a low cost in a smaller number of steps compared to the conventional method of cutting one tooth at a time.
By using the finishing die, the accuracy of the tooth profile can be increased, and it can be applied to mass-produced products with excellent effects.

[Brief description of the drawings]

FIG. 1 shows the relationship between a stamping die and a strip-shaped metal material according to the present invention, in which (A) is a side view and (B) is a side view.
(C) is a plan view.

2A to 2C are explanatory views showing the same molding process.

FIG. 3 is a front view showing a state in which a band-shaped metal material after tooth formation is wound in an annular shape and the butt ends are welded.

FIG. 4 is a sectional view of the same half.

FIG. 5 is a cross-sectional view showing a state of being placed in a finishing die for finishing.

FIG. 6 is a schematic perspective view of the ring gear after completion.

[Explanation of symbols]

 1 ring gear 2 tooth profile 3 tooth profile 4 pressing die 5 press machine 6 strip metal material 6'annular material 7 welding 8 finishing tooth model 9 finishing model 10 mandrel

Claims (2)

[Claims] 1. A surface of a strip-shaped metal material having a predetermined width,
A ring gear in which a tooth profile is formed by a pressing die having a tooth profile for forming a tooth profile to be molded, the band-shaped metal material is wound into a circular shape, and the butted ends thereof are welded. 2. One side of a strip-shaped metal material having a predetermined width,
A step of pressing a tooth profile with a pressing die having a tooth profile for forming a tooth profile to be molded, a step of winding a band-shaped metal material on which the tooth profile is formed into an annular shape, and a step of welding its butt ends The step of placing the annular material in a finishing die around which a regular finishing tooth die is provided, and press-fitting the tooth profile formed on the material into the finishing tooth die to finish-form Ring gear manufacturing method including.