JP2513541B2 - Work positioning method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work having a tooth profile on the periphery thereof. For example, when a preform of a gear is set in a forging die to improve its accuracy by plastic working, the preform is The present invention relates to a work positioning method for accurately positioning a work with a forging die.

[0002]

2. Description of the Related Art As described above, when setting a work having a tooth profile around it, such as a gear preform, in the forging die, the preform tooth profile is used as a tooth shaping tooth in the forging die. Must be positioned to match. Conventionally, as a method of positioning a preform of a gear, for example, as described in Japanese Utility Model Publication No. 63-28193, a guide body provided on a die for guiding a work, and a guide body rotatably provided on the outer periphery of the guide body. Utilizing a work positioning device having a ring having unevenness on the inner periphery to support the work on the inner periphery, and an injection port provided on the guide body for injecting air in a direction of rotating the ring with respect to the unevenness, There is known a technique in which a work is supported on a workpiece and the ring is positioned by rotating the ring so that the concave portion formed on the workpiece and the convex portion formed on the core coincide with each other.

[0003]

According to the conventional method, since the concave portion formed on the work and the convex portion formed on the core are aligned with each other, the convex portion is indispensable to the work, and the work is a workpiece. It has been wasteful to form a convex portion on the preform that can be used only for positioning. The present invention is a rational positioning method developed for the purpose of effectively utilizing the tooth profile for positioning.

[0004]

According to the structure of the present invention, for a work having a tooth profile on the entire circumference, two or more positioning claws having engaging teeth matching the tooth profile at the tip are provided in the radial direction. The position of the work is once accurately determined by advancing to the position where it can mesh with the tooth profile, dropping the work into the center, and meshing the meshing teeth of the positioning claw with the tooth profile of the work. After that, a work positioning method for releasing the meshing with the positioning claw and guiding the work into the die, and for a work having a tooth profile on the entire circumference, two or more positioning claws provided with meshing teeth matching the tooth profile at the tip. By advancing from the radial direction toward the center, the work is finely rotated so that its tooth profile and the meshing teeth of the positioning claw mesh, and the position of the work is accurately divided once. After, there to release the engagement between the positioning pawl to the method of positioning the workpiece to be directed into the die.

[0005]

[Function] When the positioning claws are advanced in the radial direction with respect to the work, the meshing teeth with large undulations formed on the entire circumference of the work and the tooth profile with similar undulations mesh with each other by minute rotation of the work. Correctly positioned,
Further, in a work in which a chamfer having a face or a curved surface for guiding is provided in the tooth profile, it is guided by the chamfer surface and slightly rotates, and the tooth profile meshes with the meshing teeth of the positioning claws so that the position of the work is changed. Accurately determined. Especially in the former case, it is suitable for a tooth profile having a chamfer. In any of these methods, after the work position is accurately indexed, the engagement with the positioning claw is released and the work is guided into the die, so that even if the tooth tips come into contact with each other and indexing is not possible. , You can redo many times before being guided into the die.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for carrying out the work positioning method according to the present invention will be described by taking a cold forging die as an example.
Reference numeral 1 is a die for cold forging, around which tooth shaping teeth 2
The ejector 3 is provided at the center of the bottom surface of the upsetting recess 2 provided with a so as to be retractable. Incidentally, the contact surface of the ejector 3 with the work can be devised such that the surface roughness is roughened in order to prevent the product from freely rotating.
Positioning claws 4, 4, 4 are provided on the horizontal upper surface of the die 1 along the upper surface of the die 1 so as to slide in the three radial directions. The positioning claw 4 is provided at its tip with three meshing teeth 7 each of which matches a tooth profile 6 of a work 5 which is a preformed product of a gear, and a chamfer 7a having a guide face or a curved surface is provided at an upper part thereof. Has been formed. A guide chamfer 6a is also formed on the tooth profile 6. 8 is a punch, and the positioning claws 4,
4 and 4 are interlocked with the raising and lowering operation of the punch 8, and are advanced to a position where the meshing tooth 7 at the tip is meshed with the tooth profile 6 of the work 5 to be set by hydraulic pressure, a cam or a link mechanism, etc. Retreat toward the outer circumference of 2.

According to the cold forging die in which such a positioning mechanism is incorporated, the ejector 3 is pushed up to a predetermined position in the state where the punch 8 is first raised, and the positioning claws 4, 4 are provided. 4 has advanced to a position where it meshes with the tooth profile 6 of the workpiece 5 on which the meshing teeth 7 at the tip end are set, and the workpiece 5 preformed at the center thereof.
If you drop it and set it (Fig. 3), chamfer 6a,
The slanted surfaces of 7a slide against each other and the work 5 rotates slightly,
The tooth profile 6 fits into the meshing teeth 7 and is reliably positioned (FIG. 4). When the positioning is completed, the positioning claw 4,
4 and 4 are retracted to the outside of the upsetting recess 2, and the work 5 is guided by the ejector 3 into the upsetting recess 2 while being accurately positioned as the ejector 3 descends. And the tooth profile shaping tooth 2a in the upsetting recess 2 are surely matched (FIG. 5).

In the above embodiment, the case in which the chamfer 6a for guiding is formed on the tooth profile 6 has been described.
Work 5 without guide chamfer 6a formed
′, The work 5 ′ is first set in a state of being supported by the ejector 3, and the positioning claws 4, 4, 4
The workpiece 5 on which the meshing teeth 7 at the tip are set
The work is advanced to a position where it meshes with the tooth profile 6 of ′, and the work is forcibly rotated by a small amount to be fitted and positioned (FIGS. 6 and 7).

In the above-mentioned embodiment, the one incorporated in the cold forging die has been described, but the invention is not limited to the cold forging die, and it can be applied to all the working steps that require positioning. In that case, instead of the punch and the ejector. A pusher and an elevator mechanism are used respectively. If the tooth profile is a work that does not have a chamfer for guiding, the chamfer for guiding the interlocking teeth on the positioning claw may be omitted, and the chamfer for guiding the interlocking teeth on the upper end of the ejector may be omitted. It can be used together.

[0010]

According to the present invention, since the work is accurately and reasonably positioned by utilizing the meshing between the tooth profile and the meshing teeth, it is not necessary to form an unnecessary convex portion on the work as in the conventional case. It will be eliminated, work efficiency will be greatly improved, and danger will be eliminated.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an apparatus for carrying out a work positioning method according to the present invention in a cold forging die.

FIG. 2 is an explanatory diagram of a positioning claw.

FIG. 3A is an explanatory diagram showing a positioning step, and FIG. 3B is an explanatory diagram showing a meshed state.

4A is an explanatory diagram showing a positioning step, and FIG. 4B is an explanatory diagram showing a meshed state.

FIG. 5 is an explanatory diagram showing a meshing state between meshing teeth and a tooth profile.

FIG. 6 is an explanatory diagram of a positioning process in a modified embodiment.

7A and 7B are explanatory views showing the meshing state of the meshing teeth and the tooth profile in the modified embodiment.

[Explanation of symbols]

1 ... Die, 2 ... Upset recess, 2a ... Tooth shaping tooth,
3 ・ ・ Ejector, 4 ・ ・ Positioning claws, 5 ・ ・ Workpieces (gear preforms), 6 ・ ・ Tooth profile, 6a ・ ・ Chamfer, 7 ・ ・ Mating teeth, 7a ・ ・ Chamfer, 8 ・ ・ Punch.

Claims (2)

(57) [Claims] 1. A workpiece having a tooth profile on the entire circumference thereof, and two or more positioning claws each having a meshing tooth matching the tooth profile at the tip thereof can be meshed with the tooth profile from the radial direction toward the center. After the work has been advanced, the work is dropped into the center and the meshing teeth of the positioning claw and the tooth profile of the work are meshed to accurately determine the position of the work once, and then the meshing with the positioning claw is released. Positioning method for guiding the workpiece into the die. 2. With respect to a work having a tooth profile on the entire circumference, by advancing two or more positioning claws having engaging teeth matching the tooth profile at the tip from the radial direction toward the center, A method of positioning a work in which the tooth profile and the meshing teeth of the positioning claw are slightly rotated to mesh with each other, the position of the work is accurately determined, and then the meshing with the positioning claw is released to guide the work into the die.