JP2884029B2 - Gear forging method and forging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming gears by using a water-cooled forging device in which cooling water is applied directly to a die in order to suppress a rise in the temperature of the die, and to a forming device therefor.

[0002]

2. Description of the Related Art With the practical use of gear forging, high quality gears have been manufactured. In the forging process, particularly in the hot forging process, the mold may be overheated and may be damaged. For this reason, cooling is required, and conventionally, means for directly applying cooling water to the mold to suppress the temperature rise of the mold has been employed.

[0003]

The tooth profile is the most important part for a gear and requires high precision. However, since the tooth profile is a fine pitch uneven shape, in the case of a tooth shape with chamfer, it is necessary to overcome advanced technology itself by pushing the material into the uneven shape and forming it faithfully to the chamfer tip. This is one issue that must be avoided. Even more, if the cooling water 10 accumulates in the uneven portion, the cooling water 10 is confined in the tooth forming tooth mold 5 by pushing the raw material 9 and evaporates instantaneously. , Resulting in underfilling (FIG. 3).

[0004]

SUMMARY OF THE INVENTION The present invention eliminates the adverse effect of volume expansion due to the vaporization of cooling water and facilitates pushing the material into the tooth mold for forming teeth. In addition to suppressing the temperature rise of the mold by directly applying it, the cooling water that has entered the tooth forming tooth mold by high pressure air blown out from the dead end part of the tooth forming tooth mold during gear molding is eliminated. In a forging method of a gear and a forging apparatus for directly applying cooling water to a mold to suppress a rise in a mold temperature, an air ejection port is provided at a dead end portion of a tooth form forming tooth mold, and the air ejection port is provided in the cavity. Gear forging device that can blow high-pressure air into the gear.

[0005]

[Function] By blowing off the cooling water in the tooth form forming tooth form, an inflated gas that inhibits pushing is not generated, and the tooth form forming tooth form is densely filled, so that a highly accurate tooth form with no underfill is formed. can do.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gear forging method and a gear forging apparatus according to the present invention will be described with reference to the drawings. The figure shows a forging apparatus, wherein 1 is a punch, 2 is a die, and the punch 1 and the die 2 are arranged to face each other. A cavity 4 having a tooth mold 3 is formed. The punch 1 is provided coaxially with the cavity 4 so as to be movable in the axial direction via a driving mechanism (not shown). A guide chamfer forming tooth mold 5 is integrally connected to the concave portion of the tooth form forming tooth mold 3. A dead end corresponding to a tip of the chamfer forming tooth mold 5 is provided outside the die 2. An air outlet 7 of the communicating air hole 6 is open (FIG. 2), and the air hole 6 is connected to an air hose 8 that supplies compressed air from a compressor outside the die 2. Although not shown, a cooling water discharge nozzle is provided on the side of the cavity opening surface of the die 2.

According to the forging device thus formed,
When the material 9 is pressed into the cavity 4 by the action of pressing the punch 1 against the die 2, the material 9 is plastically deformed into the shape of the cavity 4 and becomes a gear having a tooth profile around.
Although the temperature of the die rises due to the heat of the heated material and the processing heat generated due to deformation, the overheating is prevented by the cooling water discharged from the cooling water discharge nozzle. Although the cooling water relentlessly enters into the tooth form forming tooth, air is blown out from the air outlet every time the material is pressed in, and blown off by the air. Therefore, since the cooling water is not trapped, the material can be smoothly pushed in, and a highly accurate tooth profile without underfill can be formed.

[0008] In addition, during tooth formation, a high compressive force acts on the tooth forming tooth mold, which is incomparable to the air blowing pressure, so that the compressed air is forced into the air hole from the air outlet. The material is surely spread to the tip. That is, the air holes for supplying air also function as air escape holes.

The present invention can be applied not only to the type in which the punch moves up and down, but also to the high-speed type in which the punch moves horizontally. In particular, in such a high-speed type, the mold is easily overheated, so cooling is indispensable. The effect of removing the cooling water by blowing air is high.

Although the embodiment has been described with reference to a gear forging having a single row of teeth, it is needless to say that the present invention can be applied to forging of a gear having a plurality of rows of teeth. An air ejection hole is provided in a portion to be a dead end of the mold.

[0011]

According to the present invention, the cooling water in the tooth forming tooth mold can be efficiently removed, and the air holes also serve as escapes of the compressed air, so that there is a great benefit in improving the accuracy of the tooth shape.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a forging device according to the present invention.

FIG. 2 is an explanatory view showing a dead end portion of a tooth form forming tooth mold.

FIG. 3 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1. Punch, 2. Die, 3. Tooth profile forming die, 4.
..Cavity, 5 • Chamfer forming tooth mold, 6 ••
Air hole, 7 ... spout, 8 ... air hose, 9 ... material, 10 ... cooling water.

Claims (2)

(57) [Claims] 1. A cooling water is directly applied to a mold to suppress a temperature rise of the mold, and at the time of gear forming, enters into the tooth forming tooth by high pressure air blown out from a dead end portion of the tooth forming tooth. A forging method for a gear, characterized in that blown cooling water is removed. 2. A forging device in which cooling water is applied directly to a mold so as to suppress a rise in the temperature of the mold, wherein an air ejection port is provided at a dead end portion of the tooth mold for forming a tooth profile, and the air ejection port is inserted into the cavity from the air ejection port. Gear forging device capable of blowing high-pressure air.