JPH0824984A - Electrode of electric forged upsetting machine - Google Patents

Abstract

PURPOSE:To enable the continuous using for long term without hindrance to the inserting/removing of a driving shaft by forming an annular notch parts expanded with the diameter while continuing with an engaging hole to the upper and the lower end edges of the polygonal engaging hole fitted to the driving shaft. CONSTITUTION:The engaging groove 19 is notched on the outer peripheral surface of an electric conductive plate 18 and further, the horizontal engaging hole 20 having a hexagonal shape is penetrated on the axial line. The annular notches 21 expanded with the diameter while continuing with the engaging hole 20 are formed to chamfers at both end edges of the engaging hole 20, and arch-state notch parts 22 are formed to the chamfers at both end edges on the upper and the lower parts of the outer peripheral surface of the electric conductive plate 18, too. By this constitution, the electric conductive plate 18 is heated, and even in the case of developing the burr 23 at the upper end edge of the engaging hole 20 and at both end edges on the upper and the lower parts of the outer peripheral surface, this burr is not projected to the passage of a driving tool, and even in the case of using for the long term, the driving tool can easily be pulled out from the electric conductive plate 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long-life electrode used in an electric stretching machine.

[0002]

2. Description of the Related Art For example, an engine valve for an internal combustion engine is manufactured by forming a raw material into a rough body having substantially the same shape as a product, and then machining the rough body. As shown, long rod-shaped material
(1) was made into a primary coarse shape body (2) whose one end was expanded into a substantially spherical shape by an electric shrinking machine (A), and this was hot forged by a press machine to give a secondary coarse shape body (3). There is a way to.

The electric stretching machine (A) has an upper rotary electrode (4).
And a lower electrode (5), a pusher (6) below the lower electrode (5) which is moved up and down by a hydraulic device, and a power supply (7) for supplying power to both electrodes (4) and (5).

FIG. 3 shows the structure of the rotary electrode (4). As shown in FIG. 2, the rotating electrode (4) having a bottom with a reduced diameter and facing in the vertical direction is provided with a pair of left and right suspension support members (8) so that the electric stretching machine can operate.
It is supported by a horizontal immovable member (9) (A) so as to be rotatable, detachable, and immovable vertically. On the inner surface of the upper large diameter part (4a), there are four engaging protrusions (1
0) are projected inward at equal intervals.

The conductive plate (11) has a cylindrical shape, and four engaging grooves (12) facing up and down are cut on the outer peripheral surface of the conductive plate (11). A hole (13) is provided therethrough. The conductive plate (11) has an engaging groove (12) in which the engaging groove is formed in the rotary electrode (4).
They are fitted by engaging with (10) without slack, and their upper surfaces are aligned with each other in the same plane. The driving tool (14) comprises a horizontally thick hexagonal engaging plate (16) fixed to the lower end of a vertically extending drive shaft (15), and the engaging plate (16) is provided with an engaging hole (16). If the drive shaft (15) is intermittently rotated by a motor (not shown) by being removably fitted in 13), the rotating electrode (4) rotates in synchronization.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Rotating electrode (4) described above
The conductive plate (11) is made of copper, and the inside of the upper edge of the engagement hole (13) is located at a position isolated from the outside air, so the heat dissipation is poor, and the temperature becomes high during the work of contracting the work. Therefore, if the stretching operation is repeated many times, as shown in FIG. 4, the end edge portion gradually deforms inward, and a flash (17) occurs. In such a case, it becomes difficult to disassemble each of these members, for example, when the rotary electrode (4) is replaced, and it is often necessary to carry out repair processing. It is an object of the present invention to provide an electrode for an electric stretcher that does not need to be repaired even if it is continuously used for a long period of time.

[0007]

According to the present invention, the above-mentioned problems are solved by energizing a work held between upper and lower electrodes,
In an electric stretching machine in which the upper end of the work is expanded by pressing it toward the upper electrode, the upper electrode is connected to the rotating electrode with which the upper end of the work contacts and the bottomed hole in the upper part. It is made of a conductive plate that is detachable, is fitted in a detent, and has a polygonal engagement hole into which the drive shaft is inserted, and engages with the upper edge of the periphery of the engagement hole. The problem is solved by forming an annular notch that continuously expands in diameter with the hole.

[0008]

According to the present invention, since a notch having a diameter that is continuous with the engagement hole is formed at the upper edge of the periphery of the engagement hole of the conductive plate, the engagement hole can be prevented from rising due to the temperature rise during the contraction. Even if the upper edge is deformed and burrs are generated inward, the upper edge does not protrude to the passage of the drive shaft, and therefore, it can be continuously used for a long period of time.

[0009]

EXAMPLE FIG. 1 shows a conductive plate (18) used for the electrode of the present invention.
Since the other members are the same as those described above, the same reference numerals are given and the description thereof will be omitted. On the outer peripheral surface of the conductive plate (18),
The engaging groove (19) similar to the above is cut, and on the axis,
A hexagonal engagement hole (20) similar to the above is provided.

At the upper and lower edges of the engaging hole (20), the engaging hole (20)
An annular notch (21) that continuously expands in diameter is cut and chamfered, and arcuate notches (22) are also cut and chamfered at both upper and lower edges of the outer peripheral surface of the conductive plate (18). .

Therefore, the conductive plate (18) is heated and the engaging hole (2
The same burrs as above (23) on the upper edge of (0)
Even if occurs, it does not protrude into the passage of the driving tool (14), and even if it is continuously used for a long period of time, the driving tool (14) does not move from the conductive plate (18).
Can be easily pulled out.

[0012]

According to the present invention, even if the upper edge of the engaging hole is deformed due to the temperature rise during work shrinkage and a burr is generated inward, a drive shaft for rotating the electrode is provided. It does not project up to the entrance / exit passage, so there is no hindrance to insertion / removal of the drive shaft, and therefore it can be used continuously for a long period of time.

[Brief description of drawings]

FIG. 1 is an enlarged front view of a central longitudinal section of a conductive plate used for an electrode of the present invention,

FIG. 2 is a front view of an electric shrinking machine showing a work shrinking step.

FIG. 3 is an exploded perspective view of a conventional electrode.

FIG. 4 is an enlarged front view of the center of the conductive plate.

[Explanation of symbols]

 (A) Electric stretching machine (1) Material (2) Primary rough body (3) Secondary rough body (4) Rotating electrode (4a) Upper part (5) Lifting electrode (6) Pusher (7) Power supply (8) Suspension support (9) Immovable part (10) Engagement ridge (11) Conductive plate (12) Engagement groove (13) Engagement hole (14) Drive tool (15) Drive shaft (16) Engagement plate (17) Burr (18) Conductive plate (19) Engagement groove (20) Engagement hole (21) Annular notch (22) Arc notch (23) Burr

Claims (1)

[Claims] 1. An electric stretcher in which the work sandwiched between the upper and lower electrodes is energized and pressed toward the upper electrode to expand the diameter of the upper end of the work. , A conductive plate having a rotating electrode with which the upper end of the work abuts, and a polygonal engaging hole which is detachably and non-rotatably fitted in a bottomed hole in the upper part thereof, and in which a drive shaft is fitted on an axis line. And an annular notch having a diameter that continuously increases with the engagement hole is formed at an upper edge of the periphery of the engagement hole.