Forging method and forging apparatus

Patent metadata

Field	Value
Publication number	US-2016354835-A1
Application number	US-201615172281-A
Country	US
Kind code	A1
Filing date	Jun 3, 2016
Priority date	Jun 4, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A forging method is set in a shaping hole of a die body, and the forging material is pressed with a punch to perform plastic shaping of the forging material. Ultrasonic vibration having a vibration frequency is applied to the die body with a vibration applying apparatus during the plastic shaping of the forging material. The vibration frequency is converged to a resonance frequency of the die body when the vibration frequency is within a tracking range of the vibration applying apparatus during the plastic shaping of the forging material. When the tracking range is shifted in accordance with a discontinuous change of the resonance frequency during the plastic shaping of the forging material to deviate from the vibration frequency, the reference frequency is changed so as to fall within a shifted tracking range.

First claim

What is claimed is:

1 . A forging method comprising:
setting a forging material in a shaping hole of a die body; pressing the forging material with a punch to perform plastic shaping of the forging material; applying ultrasonic vibration having a reference frequency as an initial value of a vibration frequency to the die body with a vibration applying apparatus during the plastic shaping of the forging material; and converging the vibration frequency to a resonance frequency of the die body during the plastic shaping of the forging material when the vibration frequency is within a tracking range of the vibration applying apparatus, wherein when the tracking range is shifted in accordance with a discontinuous change of the resonance frequency during the plastic shaping of the forging material to deviate from the vibration frequency, the reference frequency is changed so as to fall within a shifted tracking range.

2 . The forging method as recited in claim 1 ,
wherein a contact state of the forging material with respect to a shaping hole inner peripheral surface of the die body changes during the plastic shaping of the forging material from an insufficient contact state to a sufficient contact state, and wherein the reference frequency is changed after shifting of the contact state from the insufficient contact state to the sufficient contact state.

3 . The forging method as recited in claim 1 ,
wherein the forging material is extruded rearward so as to be filled into a punch outer peripheral gap between a punch outer peripheral side surface and a shaping hole inner peripheral surface of the die body during the plastic shaping of the forging material, wherein a contact state of the forging material with respect to the punch outer peripheral side surface changes during a process that the forging material is being filled in the punch outer peripheral gap from an insufficient contact state to a sufficient contact state, and wherein the reference frequency is changed after shifting of the contact state of the forging material with respect to the punch outer peripheral side surface from the insufficient contact state to the sufficient contact state.

4 . The forging method as recited in claim 1 , further comprising:
obtaining a time of shifting a contact state of the forging material with respect to a shaping hole inner peripheral surface of the die body from an insufficient contact state to a sufficient contact state based on an elapsed time from a start time of the plastic shaping of the forging material by the punch; and determining a time of changing the reference frequency based on the obtained time.

5 . The forging method as recited in claim 1 , further comprising:
obtaining a punch load at a time of shifting of a contact state of the forging material with respect to a shaping hole inner peripheral surface of the die body from an insufficient contact state to a sufficient contact state; and determining a time of changing the reference frequency based on the obtained punch load.

6 . The forging method as recited in claim 3 , further comprising:
obtaining a time of shifting of the contact state from the insufficient contact state to the sufficient contact state based on an elapsed time from a start time of the plastic shaping of the forging material by the punch; and determining a time of changing the reference frequency based on the obtained time.

7 . The forging method as recited in claim 3 , further comprising:
obtaining a punch load at a time of shifting of the contact state from the insufficient contact state to the sufficient contact state; and determining a time of changing the reference frequency based on the obtained punch load.

8 . The forging method as recited in claim 1 ,
wherein application of vibration by the vibration applying apparatus is stopped immediately before changing the reference frequency, and the application of vibration by the vibration applying apparatus is restarted when the reference frequency is changed.

9 . A forging apparatus comprising:
a die body having a shaping hole; a punch configured to be driven into the shaping hole to perform plastic shaping of a forging material in the shaping hole, a vibration applying apparatus configured to apply ultrasonic vibration having a reference frequency as an initial value of a vibration frequency to the die body; and a reference frequency changing device configured to change the reference frequency of the vibration applying apparatus during the plastic shaping of the forging material.

10 . The forging apparatus as recited in claim 9 ,
wherein the vibration applying apparatus includes a vibrator attached to the die body and an ultrasonic vibration device.

11 . The forging apparatus as recited in claim 9 , further comprising:
a timer configured to measure an elapsed time from a start of the plastic shaping of the forging material by the punch during the plastic shaping of the forging material, wherein the reference frequency changing device is configured to change the reference frequency based on the elapsed time.

12 . The forging apparatus as recited in claim 9 , further comprising:
a load detector configured to detect a load of the punch applied to the forging material, wherein the reference frequency changing device is configured to change the reference frequency at a time when the load of the punch has reached a reference frequency changing load value set in advance based on information from the load detector during the plastic shaping of the forging material while applying the ultrasonic vibration to the die body.

Assignees

• Showa Denko Kk

Inventors

• MIYASHITA Ichitami

Classifications

• B21J5/006

  using ultrasonic waves · CPC title

• B21J5/02

  Die forging; Trimming by making use of special dies {; Punching during forging} · CPC title

• B21J9/20 Primary

  Control devices specially adapted to forging presses not restricted to one of the preceding subgroups · CPC title