JP2001259783A - Hot die forging stock for bevel gear, manufacturing device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot die forging stock for a bevel gear, a manufacturing device and a manufacturing method thereof that a cutting margin for finishing the gear tooth can be reduced, the yield and the machining efficiency can be improved, and the forging load can be reduced by reducing excessive materials. SOLUTION: The hot die forging stock 1 for the bevel gear is formed in a notch between a tooth 5 and a tooth 5 while an outer circumferential edge of a flat surface of a body 8 forming a back side of the tooth 5 formed on an outer circumferential surface of a body 2 includes a back side, a tooth 5a on the back side appears on the flat surface, and the surface of the body 8 is formed into a smooth spherical or tapered surface from a center portion to the outer circumferential edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot stamping blank for bevel gears used in, for example, a differential mechanism of an automobile, and an apparatus and method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, this type of hot stamping blank for bevel gears
Reference numeral 51 had a shape as shown in FIG. That is, teeth 55 are formed on the outer peripheral surface centered on the center hole 53 of the main body 52 so as to be inclined from the bottom surface toward the plane, and the rear side, which is the upper end of the teeth, passes through the plane 56 further above it. The flat surface has a surplus 57 consisting of a flat surface on the outer peripheral side and a gentle taper surface on the inner peripheral side toward the center hole 53. Does not appear (not seen from a plane). Thus, such a crude material 51 is manufactured by hot (warm) die forging. Further, after manufacturing, it is annealed and formed by cold stamping forging with the surplus thickness 57 as shown by the chain line in FIG. Thereafter, the outer peripheral edge is cut so that the back side of the teeth 55 appears on the flat surface 61 by processing the chain line portion of the rough material 51, and the back surface shaping process is performed on the flat surface 61 to obtain a final product (see the solid line in FIG. 6). ). Processing after annealing may be performed at a customer who has purchased the manufactured crude material 51.

Since the conventional raw material 51 has the above-described shape, a large number of outer peripheral edges are cut to form teeth on the flat surface 61 of the main body 52 when manufacturing a final product by cutting. Therefore, there is a problem in that the yield of machining and the processing efficiency are not good due to an increase in the amount of cutting work, and the forging load is large and the holding of the mold is not good due to the large area of the flat surface on the back side.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the conventional problems as described above, can reduce the cutting allowance for toothing and the like, can improve the yield and improve the machining efficiency, An object of the present invention is to provide a hot stamping blank for bevel gears that can reduce a forging load due to a reduction in excess thickness, and an apparatus and method for manufacturing the same.

[0005]

In order to achieve the above object, the invention of a hot stamping blank for bevel gears according to claim 1 is a hot stamping for bevel gears having teeth formed on an outer peripheral surface of a main body. In the coarse material, an outer peripheral edge of a main body plane on the back side of the teeth is formed in a concave shape between the teeth including the back side, and the teeth on the back side are formed so as to appear on a plane. Are formed in a gentle spherical or tapered surface from the center to the outer peripheral edge.

According to a second aspect of the present invention, there is provided an apparatus for manufacturing a hot stamped rough blank for bevel gears according to claim 1 by hot stamping and forging. Equipped with a hot die forging machine in which a die is installed at a lower part and a punch is installed at an upper part, and a lower end part of a punch which is pushed into a die of the hot die forging machine. A tooth portion for forming a tooth continuous with the tooth on the outer peripheral edge of the main body plane is formed.

A third aspect of the present invention is a method of manufacturing a hot stamped rough blank for bevel gears according to claim 1 by hot stamping and forging. Forming teeth on the outer peripheral surface of the main body with a die of a hot stamping and forging machine, and simultaneously forming the teeth continuous with the teeth on the outer peripheral edge of the main body rear side plane with a punch in cooperation with the die. Features. According to a fourth aspect of the present invention, there is provided a method for manufacturing a hot stamping blank for bevel gears, wherein the hot stamping blank for bevel gears according to claim 1 is formed using a cold stamping and forging machine having the same structure as in claim 2. And forged by cold forging.

[0008]

An embodiment of the present invention will be described with reference to the drawings. 1A and 1B show a hot stamping blank for bevel gears, wherein FIG. 1A is a plan view with a half part omitted, FIG. 1B is a front sectional view, and FIG. 1C is a bottom view with a half part omitted. In the figure, reference numeral 1 denotes a hot stamping blank for bevel gears made of structural steel.
The teeth 5, 5a are formed in a continuous form inclined from the bottom surface toward the plane on the outer peripheral surface centered at. Tooth 5,5a
The outer peripheral edge of the plane of the main body 2 on the back side of the body is cut in a concave shape between the teeth 5, 5a and the teeth 5, 5a including the back side, so that the teeth 5a on the back side appear on the plane. ing. Reference numeral 6 denotes a concave portion formed by the cutting. The plane of the main body 2 is formed as a gentle spherical surface 8 from the center hole 3 toward the outer peripheral edge. The spherical surface 8 may not be a spherical surface as long as it is a gentle surface close to a final product described later, and may be a tapered surface, for example.

FIG. 2 shows an apparatus for producing the above-described hot stamping blank 1 for bevel gears. This production equipment has a die 12
And a hot stamping and forging machine 11 in which a pushing punch 13 is provided at an upper part. The punch 13 includes a punch 15 for forming the center hole 3, and a tooth 5 a disposed outside the punch 15 and pressed into the die 12, which is continuous with the tooth 5 formed by the die 12.
Is formed on the outer peripheral edge of the plane of the main body 2, and a tooth portion 17 for forming the teeth 5 a is formed at the lower end of the punch 16. Reference numeral 18 denotes an ejector, and 19 denotes a punch holder.

The manufacturing process of the hot stamping blank 1 for bevel gears by the manufacturing apparatus as described above will be described in order with reference to FIG. First, as preforming, a toothless wasteland shape having a predetermined height and a predetermined diameter is formed by a hot stamping and forging machine (FIG. 3A). Next, the main body 2 ′ is to be finished molded.
Is inserted into the hot stamping and forging machine 11, and the teeth 5 are formed on the outer peripheral surface of the main body 2 by the die by the pressing action of the punch 16 against the die 12 of the forging machine. At this time, the outer peripheral edge of the plane of the main body 2 is formed including the back side by the punch 16 cooperating with the die 12, and the teeth 5a continuous with the teeth 5 are formed on the outer peripheral edge of the plane of the main body 2, and the teeth 5, 5a are formed. And teeth 5, 5a
A recess 6 is formed between them. At the same time as this molding, the plane is formed into a spherical surface 8 by the punch 16 and
At 15, a center hole 3 ′ for inserting the shaft is formed in the main body 2 (FIG. 3B). After that, using a hole punch (not shown)
The center hole 3 'is punched to form the center hole 3 (FIG. 3C). With this, the finish forming of the raw material 1 is completed.

The manufactured raw material 1 is further subjected to cold forging and cutting by a cold stamping and forging machine (not shown) at a customer or the like to obtain a final product. This will be described with reference to FIG. First, the crude material 1 after production
Is subjected to a softening heat treatment. In addition, crude material 1 is used for cold stamping and forging machines.
, And the teeth 5, 5a are further cold-formed by the forging machine (FIG. 4A). And finally, when the flat side of the rough material 1 is formed into a tapered surface 22 inclined downward from the center hole 3 toward the outer peripheral edge by performing a shaping process such as a cutting process of a surplus wall on the flat spherical surface 8 using a lathe or the like. Final product shown by solid line
21 (FIG. 4B). At this time, the opening edge of the center hole 3 is also cut to have a rounded shape. This figure 4
The steps (A) and (B) may be performed at a customer who has purchased the raw material 1 or may be performed at the same place as the place where the raw material 1 is manufactured.

As can be seen by comparing FIG. 4B with FIG. 6 of the related art, the production of the hot stamped blank 1 for bevel gears by this production method is a method of cutting excess material when the final product is obtained. Since the cost can be reduced, the amount of cutting is small. Therefore, the yield can be improved and the processing efficiency can be improved.

The hot stamping blank 1 for bevel gears described above is only a preferred example, and the design of details such as, for example, not requiring a center hole is various within the scope described in the claims. Changes are possible.

[0014]

Since the present invention has the above-described structure, it is possible to reduce a cutting allowance for toothing and the like and to improve the yield as compared with the conventional hot stamping blank for bevel gears. And the processing efficiency can be improved. Also,
There is an excellent effect that the forging load can be reduced by reducing the excess thickness.

[Brief description of the drawings]

FIG. 1 shows a hot stamping blank for bevel gears according to an embodiment of the present invention, wherein (A) is a plan view with a half part omitted, (B) is a front sectional view, and (C) is a half part omitted. FIG.

FIG. 2 is a vertical sectional view of a manufacturing apparatus of a hot stamping blank for bevel gears, in which a right half is omitted.

3 (A) to 3 (C) are drawings showing a manufacturing process of a hot stamping blank for bevel gears.

4 (A) and 4 (B) are drawings showing a manufacturing process of a hot stamping blank for bevel gears.

5A and 5B show a conventional hot stamping blank for bevel gears, in which FIG. 5A is a plan view with a half part omitted, FIG. 5B is a front sectional view, and FIG. 5C is a bottom view with a half part omitted.

FIG. 6 is a view illustrating a process of manufacturing a conventional hot stamping blank for bevel gears.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot stamping rough material for bevel gear 2 Main body 3 Center hole 5,5a tooth 6 Concave notch 8 Spherical surface 11 Hot stamping forging machine 12 Dies 13,15,16 Punch 17 Tooth part

Claims (4)

[Claims] 1. A hot stamping blank for bevel gears having teeth formed on an outer peripheral surface of a main body, wherein an outer peripheral edge of a main body plane on a rear side of the teeth includes a rear side and is concave between the teeth. For bevel gears, wherein the bevel gear is formed so as to be formed in a notch shape, so that the teeth on the back side appear on a plane, and the main body plane is formed as a gentle spherical surface or a tapered surface from the center to the outer peripheral edge. Hot stamping material. 2. An apparatus for manufacturing a hot stamping blank for bevel gears according to claim 1 by hot stamping and forging, wherein a die is provided at a lower portion and a punch is provided at an upper portion. A tooth portion for forming a continuous tooth of the outer peripheral surface of the main body formed by the die on the outer peripheral edge of the main body plane is formed at the lower end of the punch which is pressed into the die of the hot stamping and forging machine. An apparatus for manufacturing a hot stamping rough material for bevel gears. 3. A method for producing a hot stamping rough material for bevel gears according to claim 1 by hot stamping and forging, wherein teeth are formed on an outer peripheral surface of a main body by a die of a hot stamping and forging machine. A method of manufacturing a hot stamping raw material for bevel gears, wherein teeth cooperating with the dies are formed simultaneously with the teeth on the outer peripheral edge of the flat surface on the rear side of the main body by a punch. 4. A bevel gear manufactured by cold forging the hot stamped rough material for bevel gears according to claim 1 using a cold stamping and forging machine having the same structure as in claim 2. Method for producing hot stamping blanks.