JPH08300083A - Internal gear manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a manufacturing method of an internal gear capable of simplifying the manufacturing process, improving the accuracy of the product, downsizing and strengthening the product, and improving the yield of the used material. [Structure] A plate-shaped material is press-formed into a cup shape, and then the formed cup-shaped material W is used to mold an internal gear 1
After the disk portion of the cup-shaped material W is clamped by the internal gear forming mold 1 and the clamping mold 2, the internal gear forming mold 1 is rotated while being rotated at a required number of revolutions. While pressing the molding roller 3 having a rotation axis parallel to the axis against the outer peripheral surface of the cup-shaped material W, the molding roller 3 is relatively moved along the internal gear molding die 1 to move the inner peripheral surface of the cup-shaped material W. The tooth profile is formed by cold plastic working.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a material formed into a cup shape by pressing, forging, or casting, and the tooth profile of an internal gear is formed on its inner peripheral surface by cold plastic working. The present invention relates to a method of manufacturing an internal gear.

[0002]

2. Description of the Related Art Many internal gears are used in automobile speed reducers and other machines. By the way, in the method of manufacturing an internal gear with a boss portion having a disk with a boss portion on one side,
As shown in FIG. 5 (A), a steel material cut into a required size is heated to a required temperature, a disk with a boss portion is formed by hot or warm forging, and further this is machined to a predetermined accuracy. 5, the bossed disc W1 and the pipe member W2, which has a tooth profile formed by machining on the inner peripheral surface of the pipe material, are welded together to form a bossed internal gear W3, and FIG.
As shown in (B), a steel material cut into a required size is heated to a required temperature and hot-forged to form a cup-shaped material W4 in the shape of an internal gear with a boss portion. There is a method of forming a tooth profile on the inner peripheral surface of W4 by machining to obtain an internal gear W5 with a boss. Further, in the method for manufacturing an internal gear having a disc on one side, as shown in FIG. 6, a steel material cut into a required size is heated to a required temperature,
Hot-forged cup-shaped material W6 roughly in the shape of an internal gear
Then, a tooth profile is formed on the inner peripheral surface of the cup-shaped material W6 by machining to form the internal gear W7.

[0003]

By the way, the conventional method for manufacturing an internal gear has the following problems. (1) Since the tooth profile is formed by machining on the inner peripheral surface of the material formed by hot or warm forging, the process of hot or warm forging and machining It requires a process, especially by forging the disk W1 with a boss,
In the case where the inner tooth portion is formed by the pipe member W2, a welding process is further required, the production efficiency is low due to an increase in the number of processes, the manufacturing cost is high, and heat distortion occurs during welding. (2) Since the tooth profile is formed by machining, when forming the tooth profile on the inner peripheral surface in the vicinity of the disc, it is necessary to allow the cutting tool to escape at the inner bottom part, so that the tooth profile is formed over the entire inner peripheral surface of the tubular part. It cannot be formed, and the effective length of the tooth becomes short.In order to secure the effective length of the tooth, it is necessary to lengthen the entire length of the product, and the metal flow is cut by machining, resulting in poor strength. Therefore, it is necessary to perform heat treatment in order to increase the strength of the machined product. (3) The yield of materials used is poor due to machining.

The present invention solves the problems of the above-mentioned conventional method of manufacturing an internal gear, and simplifies the manufacturing process, improves the accuracy of the product, reduces the size and strength, and improves the yield of the material used. The object is to provide a method for manufacturing a possible internal gear.

[0005]

In order to achieve the above object, a method for manufacturing an internal gear according to the first aspect of the present invention is such that a plate-shaped material is formed into a cup shape by pressing and then the formed cup-shaped material is formed. After fitting into the internal gear molding die and holding the disk portion of the cup-shaped material between the internal gear molding die and the clamping die, the internal gear molding die is rotated at the required rotation speed. While pressing the molding roller having a rotation axis parallel to the rotation axis of the cup-shaped material against the outer peripheral surface of the cup-shaped material, the teeth are formed on the inner peripheral surface of the cup-shaped material by relatively moving along the inner gear molding die. The main point is to form by cold plastic working.

Further, according to the method of manufacturing an internal gear of the second aspect of the present invention, a cup-shaped material formed by forging or casting is fitted into an internal gear molding die, and the disk portion of the cup-shaped material is used for internal gear molding. After sandwiching between the mold and the sandwiching mold, while rotating at the required number of rotations, press the molding roller having the rotation axis parallel to the rotation axis of the internal gear molding die against the outer peripheral surface of the cup-shaped material. However, the gist is to form the tooth profile on the inner peripheral surface of the cup-shaped material by cold plastic working by moving the tooth profile relatively along the internal gear molding die.

In the above first and second inventions,
An internal gear with a boss can be manufactured by using a cup-shaped material having a boss.

[0008]

According to the present invention, the cup-shaped material is formed by pressing, forging, or casting, while the forming roller is pressed against the outer peripheral surface of the cup-shaped material, and the cup-shaped material is relatively moved along the internal gear forming die. Since the tooth profile is formed on the inner peripheral surface of the material by cold plastic working, the manufacturing process can be simplified. Further, since the tooth profile is formed by cold plastic working by rotational forming, it is possible to form the tooth profile over the entire length of the inner peripheral surface of the tubular portion, and the metal flow is not cut so that it is cold-formed. The strength of the product is increased by the internal stress generated during the plastic working, and it is possible to improve the precision, downsizing and strength of the product and improve the yield of the material used.

Further, by using the cup-shaped material having the boss portion, the internal gear with the boss portion can be easily manufactured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing an internal gear according to the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a diagram showing an internal gear manufacturing method using a plate material for deep drawing, for example, a carbon steel plate, a low alloy steel plate, an aluminum alloy plate, etc., to produce an internal gear by combining press working and roller forming. 1 shows an embodiment (first embodiment) of a method for manufacturing an internal gear of the invention.

First, the required plate-shaped material (specifically, when the outer diameter of the internal gear to be manufactured is 80 to 170 mm, it is desirable to use a plate having a plate thickness of approximately 3.2 mm or more. However, the present invention is not limited to this.) Is pressed into a cup shape having an outer diameter calculated in advance according to the material thickness from the mass of the internal gear to be manufactured, and the cup-shaped material W is formed. obtain. (Fig. 1 (A))

Next, the cup-shaped material W is fitted into the internal gear molding die 1 having the tooth profile 1H formed on the outer peripheral surface. (Figure 1
(B)) In this case, the inner diameter of the cup-shaped material W is set to the internal gear molding die 1
The outer diameter of the cup-shaped material W is slightly larger than the outer diameter of the inner-shaped gear W, so that the cup-shaped material W can be reliably fitted into the internal gear molding die 1.

After that, after the disk portion of the cup-shaped material W is clamped by the internal gear forming mold 1 and the clamping mold 2, the internal gear forming mold 1 is rotated while being rotated at a required rotation speed. The forming roller 3 having a rotation axis parallel to the axis is formed into a cup-shaped material W.
The tooth profile is formed by cold plastic working on the inner peripheral surface of the cup-shaped material W by relatively moving it along the inner gear molding die 1 while pressing it against the outer peripheral surface of. (FIG. 1 (C)) Incidentally, after the tooth profile is formed on the inner peripheral surface of the tubular portion, the outer peripheral surface, the end portion and the like are processed by machining (race processing) or the like as necessary, that is, the product, that is, , And the internal gear Wa shown in FIG.

In this case, the sandwiching die 2 is substantially the center of the disk portion of the cup-shaped material W fitted into the internal gear forming die 1, that is, the two dies 1 and 2 are on the same rotation axis. The cup-shaped material W is clamped and supported. The pressure for sandwiching the forming material W between the molds 1 and 2 is such that when the internal gear forming mold 1 is rotated and the cup-shaped material W is subjected to cold plastic working by the forming roller 3, Determine the shape material W so that it can be firmly supported. In addition, the internal gear molding die 1
The forming roller 3 having an axis of rotation parallel to the axis of rotation of the cup-shaped material W is arranged in the radial direction of the outer peripheral position of the internal gear molding die 1 into which the cup-shaped material W is fitted, depending on the material, shape and size of the cup-shaped material W. One or a plurality of them are arranged at substantially equal intervals or at appropriate intervals. When a plurality of forming rollers 3 are arranged, they may be arranged in the same shape and size, or may be arranged in different shapes and sizes. It is selected according to the material, shape, and size of W. Further, the molding roller 3 may be arranged at an equal distance from the rotation center of the molding die 1 or may be arranged at a different distance from each other. In response to the,
To choose. Further, the pressures for pressing the forming roller 3 against the outer peripheral surface of the cup-shaped material W can be set to the same pressure or different pressures. Then, this pressure is applied in a direction perpendicular to the rotation axis of the internal gear molding die 1. Also, the internal gear molding die 1
And the cup-shaped material W clamped by the clamping die 2
Is a predetermined number of rotations for both molds 1 and 2, for example, 18 per minute
While rotating at 0 to 700 revolutions, the molding roller 3 is directed from one end position of the internal gear molding die 1 toward the other end, in parallel with the rotation axis of the internal gear molding die 1, and at a predetermined feed rate. , For example, relatively move at a feed rate of 0.2 m / min. The rotation speed of the cup-shaped material W, the feed speed of the forming roller, the pressing force, the moving pressure, etc., are
It is determined according to the material, shape, and size of the.

As described above, the cold plastic working of the tubular portion of the cup-shaped material W is performed by the combination of the rotation of the cup-shaped material W sandwiched between the molds 1 and 2 and the pressing movement of the forming roller. This is continuously performed, and the inner teeth are simultaneously formed according to the tooth profile 1H formed on the outer peripheral surface of the inner gear forming die 1. At this time, the forming roller 3 is controlled by the CNC control so that the pressing force is kept constant, and the forming roller 3 is adjusted to adjust the outer peripheral shape of the cup-shaped material W, that is, the internal gear.
Rotates following the rotation of the cup-shaped material W so that the peripheral velocities of the forming roller 3 and the outer peripheral surface of the cup-shaped material W become equal. Further, in order to increase the strength by cold plastic working, a coolant is sprayed on the cold plastic working portion at a predetermined pressure to prevent heat generation during cold plastic working, and at the same time, between the forming roller 3 and the cup-shaped material W. Lubricate.

In the case of the first embodiment, the plate-shaped material is formed into a cup shape by press working, and the cup-shaped material is fitted into the internal gear forming die, but it is circular. While sandwiching the plate-shaped material of No. 2 between the opposite molds 1 and 2, and molding it into a cup shape with a molding roller,
It is also possible to mold the internal teeth at the same time.

FIG. 2 shows a second example of manufacturing an internal gear by using carbon steel, low alloy steel, aluminum alloy steel, and other metals and combining forging and roller forming.
The Example (2nd Example) of the manufacturing method of the internal gear of this invention is shown.

In the second embodiment, first, the cup-shaped material W0 having the boss portion B is formed by forging. (FIG. 2 (A)) In this case, heat treatment is performed to maintain the strength of the cup-shaped material W0, for example, in the case of carbon steel or low alloy steel, 8
Although annealing is performed at about 60 ° C., depending on the material of the cup-shaped material W0, for example, in the case of low carbon steel, the heat treatment can be omitted. Further, mechanical processing (lace processing) is performed in order to finish the inner peripheral surface of the tubular portion of the cup-shaped material W0 with a predetermined accuracy.

Next, the cup-shaped material W0 is fitted into the internal gear molding die 1 having the tooth profile 1H formed on the outer peripheral surface. (Fig. 2
(B))

After that, the disk portion of the cup-shaped material W0 is clamped by the internal gear molding die 1 and the clamping die 2, and then the internal gear molding die 1 is rotated while rotating at the required number of revolutions. The cup-shaped material W0 is relatively moved along the internal gear molding die 1 while pressing the molding roller 3 having a rotation axis parallel to the axis against the outer peripheral surface of the cup-shaped material W0.
The tooth profile is formed on the inner peripheral surface of by cold plastic working. (Fig. 2
(C)) Incidentally, after the tooth profile is formed on the inner peripheral surface of the tubular portion, the outer peripheral surface, the end portion and the like are processed by machining (race processing) or the like, if necessary, that is, the product, that is, FIG. The internal gear Wb with a boss portion shown in FIG.

The processing conditions such as the number of forming rollers 3 installed in the second embodiment are set to the material and shape of the cup-shaped material W0,
The determination according to the size or the like is the same as in the first embodiment.

FIG. 3 shows an embodiment of an internal gear manufacturing method of the second invention of the present invention in which an internal gear is manufactured by combining casting and roller forming, for example, using aluminum alloy steel and other metals. Example)

In the third embodiment, first, a cup-shaped material W0 'having a boss portion B is formed by casting.
(Fig. 3 (A))

Next, the cup-shaped material W0 'is fitted to the internal gear molding die 1 having the tooth profile 1H formed on the outer peripheral surface. (Fig. 3
(B))

After that, the disc portion of the cup-shaped material W0 'is held between the inner gear forming die 1 and the holding die 2 and then,
While rotating at a required number of rotations, the molding roller 3 having a rotation axis parallel to the rotation axis of the internal gear molding die 1 is pressed against the outer peripheral surface of the cup-shaped material W0 ′, and the internal gear molding die 1 is pressed. A tooth profile is formed on the inner peripheral surface of the cup-shaped material W0 ′ by cold plastic working by moving the cup-shaped material W0 ′ relative to each other.
(FIG. 3 (C)) After the tooth profile is formed on the inner peripheral surface of the tubular portion, the outer peripheral surface, the end portion, and the like are processed by machining (race processing) or the like, if necessary, that is, the product, that is, The internal gear Wb with a boss shown in FIG.

The processing conditions such as the number of forming rollers 3 installed in the third embodiment are determined in accordance with the material, shape, size, etc. of the cup-shaped material W0 ', as in the second embodiment. .

[0028]

According to the invention described in claim 1 (first invention), while pressing the forming roller against the outer peripheral surface of the cup-shaped material formed by pressing the plate-shaped material,
Since the tooth profile is formed on the inner peripheral surface of the cup-shaped material by cold plastic working by relatively moving along the internal gear forming die, the manufacturing process can be simplified. Also,
Since the tooth profile is formed by cold plastic working by rotational forming,
A tooth profile can be formed over the entire length of the inner peripheral surface of the tubular portion, the metal flow is not cut, and the strength of the product is increased by the internal stress generated during cold plastic working. Higher precision, smaller size, higher strength, and higher yield of used materials can be achieved.

According to the invention described in claim 2 (the second invention), the molding roller is pressed against the outer peripheral surface of the cup-shaped material formed by forging or casting, and along the inner gear forming die. Since the tooth profile is formed by cold plastic working on the inner peripheral surface of the cup-shaped material by moving it relatively,
The manufacturing process can be simplified. Further, since the tooth profile is formed by cold plastic working by rotational forming, it is possible to form the tooth profile over the entire length of the inner peripheral surface of the tubular portion, and the metal flow is not cut so that it is cold-formed. The strength of the product is increased by the internal stress generated during the plastic working, and it is possible to improve the precision, downsizing and strength of the product and improve the yield of the material used.

According to the third aspect of the present invention, by using the cup-shaped material having the boss portion, the internal gear with the boss portion can be easily manufactured without increasing the number of manufacturing steps.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing process of an internal gear according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a manufacturing process of an internal gear according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a manufacturing process of an internal gear according to a third embodiment of the present invention.

FIG. 4 is an external view in which a part of an internal gear formed by the forming method of the present invention is cut away.

FIG. 5 is an explanatory view showing a manufacturing process of a conventional internal gear with a boss portion.

FIG. 6 is an explanatory view showing a manufacturing process of a conventional internal gear.

[Explanation of symbols]

 1 Internal gear forming die 2 Clamping die 3 Forming roller W Molding material W0 Molding material W0 'Molding material Wa Internal gear Wb Internal gear with boss

Claims (3)

[Claims] 1. A plate-shaped material is press-formed into a cup shape, and then the formed cup-shaped material is fitted into an internal gear forming die, and the disk portion of the cup-shaped material is formed into an internal gear forming metal. After sandwiching between the mold and the sandwiching mold, while rotating at the required number of rotations, while pressing the molding roller having the rotation axis parallel to the rotation axis of the internal gear molding die against the outer peripheral surface of the cup-shaped material. A method for manufacturing an internal gear, wherein a tooth profile is formed on the inner peripheral surface of a cup-shaped material by cold plastic working by moving the tooth profile relatively along an internal gear forming die. 2. A cup-shaped material formed by forging or casting is fitted into an internal gear molding die, and the disc portion of the cup-shaped material is sandwiched between the internal gear molding die and the sandwiching die. , While rotating at the required number of rotations, while pressing the molding roller having a rotation axis parallel to the rotation axis of the internal gear molding die against the outer peripheral surface of the cup-shaped material, The method for manufacturing an internal gear is characterized in that the tooth profile is formed on the inner peripheral surface of the cup-shaped material by cold plastic working by mechanically moving it. 3. The method for manufacturing an internal gear according to claim 1, wherein the cup-shaped material has a boss portion.