JPH03263Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention heats a long and thin workpiece such as a round bar using a current-carrying resistor, compresses it in the axial direction, and processes it in the die (bulge molding). The present invention relates to an electric heating type forging machine, and particularly to a workpiece contact device that electrically connects a workpiece placed in a die holder to the die holder.

(Conventional technology) Conventionally, the structure was as shown in FIG.

That is, die holder a to which one electrode is connected
A fitting hole c into which the workpiece b is loosely fitted is formed inside the fitting hole c, an annular die d is attached to the die holder a at the right end of the fitting hole c, and a conductive die is attached to the left side of the fitting hole c. The anvil e is slidably and closely fitted.

The anvil e has a dish-shaped recess f formed at its right end, and the work b
The structure was such that they were pressure-connected at a tapered surface formed on the outer periphery of the left end.

In FIG. 4, g is a chute that guides workpiece b, h is a connector that conducts electricity between die holder a and anvil e, and j and k are cooling oil passages.

In the conventional device described above, the current-carrying contact part a between the die holder a side and the workpiece b side is the left end surface of the workpiece b in the axial direction, so the workpiece b-1 fitted into the fitting hole c becomes the current-carrying path. becomes.

For this reason, especially when the outer circumferential surface of the work b-1 is a rough surface forming a so-called black scale, the outer circumferential surface is locally close to the inner circumferential surface of the fitting hole c, and this spark is generated at this part. I had something to do.

In addition, the above-mentioned current-carrying contact part A has a small contact area,
There were drawbacks such as difficulty in securing a sufficient amount of current.

(Problems to be Solved by the Invention) In the present invention, the current-carrying contact between the die holder a side and the workpiece b side is made at the outer periphery of the workpiece b, and at the same time in the vicinity of the die d where the workpiece b is bulged. The object of the present invention is to obtain a workpiece contact device that allows smooth energization by positioning the workpiece contact device.

(Means for solving the problems) In order to achieve the above object, the present invention is constructed as follows.

That is, a fitting hole into which a rod-shaped workpiece is fitted is formed in a die holder to which one electrode is connected, and an annular die and a chuck into which the workpiece is fitted are arranged close to each other in the axial direction. The outer periphery of the chuck is formed into a tapered surface that widens toward the die direction, and the remaining large diameter side leaving the small diameter side is divided in the circumferential direction, and the chuck is formed in the fitting hole. An actuating body having a tapered hole that can be fitted into the tapered surface of the actuating body is provided, and a drive mechanism is provided for reciprocating the actuating body in the axial direction.

(Function) Since the present invention has the above configuration, when the actuating body is axially moved in the chuck direction by the drive mechanism, the tapered hole of this actuating body engages with the tapered surface of the chuck, and this causes the large diameter side of the chuck to move axially in the chuck direction. It is pressed in the center direction and comes into pressure contact with the outer peripheral surface of the workpiece.

Further, since the large diameter side of the chuck presses against the outer circumferential surface of the workpiece from the outside in the radial direction, increasing the length of the chuck in the axial direction increases the contact area between the chuck and the workpiece.

Furthermore, since the chuck is close to the die,
The energization points in the axial direction of the workpiece will be concentrated at the portions to be formed.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

First, in the drawings, FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a side view showing the main parts thereof, and FIG. 3 is a sectional view thereof.

In FIG. 1, 1 is a cylindrical die holder whose axial center is hollow.

The hollow part of the die holder 1 has a large diameter at its left and right ends, and a cylindrical cooling bush 2 having a spiral wall 2a on the outer periphery is fitted into the right end to form a cooling oil passage 3, which further cools the hollow part of the die holder 1. A contact bush 4 made of a cylindrical body is fitted onto the inner periphery of the bush 2.

In addition, 3a and 3b in the figure are the inlet and outlet of cooling oil.

Further, the drive mechanism 5 is fitted into the left end of the hollow portion. The drive mechanism 5 is composed of a hydraulic cylinder mechanism, in which a piston 5-2 is fitted into a cylinder 5-1 so as to be movable left and right, and a cylindrical piston rod 5-3 is connected to the piston 5-2.

Note that 5-4 and 5-5 in the figure are hydraulic oil supply ports.

Further, the inner diameter of the intermediate portion of the hollow portion is approximately the same diameter and the same axis as the inner diameter of the contact bush 4 described above, and the cylindrical connector 6 and contactor 7, which form the operating body, are arranged around the inner circumference of the contact bush 4. They fit together so that they can slide in the direction, and are connected to each other by a split clamp 8.

The inner end of the connector 6 is threadedly fitted into the piston rod 5-3, and the inner diameter of the contactor 7 is formed into a tapered hole 7a that widens toward the right.

A cylindrical chuck 9 is fitted into the inner periphery of the tapered hole 7a.

As shown in FIGS. 2 and 3, this chuck 9 has an outer periphery at the left end 9a formed into a small-diameter annular cylinder, and an outer periphery at the right end into a tapered surface 9b that widens toward the right. , slit 9c
It is processed and divided into 8 parts in the circumferential direction.

Reference numeral 9d denotes a locking piece that partially projects outward in the radial direction from the right end of the chuck 9, and is loosely fitted between the right end of the contact bush 4 and the left end of the receiving ring 10 fitted to the right end of the cooling bush 2. This is to prevent movement in the axial direction.

Here, the inner diameter of the connector 6 and the chuck 9 are
The inner diameter of the workpiece W is set to be slightly larger than the outer diameter of the workpiece W, and this portion is used as the fitting hole 11 of the workpiece W.

An annular die 12 is provided on the inner periphery of the receiving ring 10.
mate.

The inner diameter of this die 12 is such that the left half has a slightly larger diameter than the outer diameter of the workpiece W, and the right half has a larger diameter to form the bulging portion of the workpiece W.

Note that 13 is a retaining ring that prevents the die 12 from moving in the axial direction.

Furthermore, an anvil 14 for setting the insertion amount of the work W is slidably inserted into the piston 5-3, and is adjusted by moving in the left-right direction via a push rod 15.

16 is one electrode connected to the left outer periphery of the die holder 1, and the current supplied from this part is
Each member is closely connected so as to flow to the left side of the work W via the die holder 1, cooling bush 2, contact bush 4, contactor 7, and chuck 9.

The other electrode 17 is connected to the right outer periphery of the work W protruding rightward from the die holder 1, so that the current flowing through the work W flows through this electrode 17.

Next, the manner of use of the above embodiment will be explained.

First, the anvil 1 is inserted through the push rod 15.
Set the axial position of 4.

Next, the workpiece W is fitted into the fitting hole 11, its left end is brought into contact with the right end of the anvil 14, and the other electrode 17 is connected to its right side.

In this state, when hydraulic oil is force-fed from the supply port 5-4 of the drive mechanism 5 and the piston 5-2 is actuated to the right, the contactor 7 (actuating body) is moved to the right via the piston rod 5-3 and the connector 6. I will have to move.

As a result, the taper hole 7a of the contactor 7
presses the tapered surface 9b of the chuck 9 to elastically deform the right portion of the chuck 9 in the axial direction, and its inner peripheral surface is pressed against the outer peripheral surface of the workpiece W.

In this state, from one electrode 16 to the die holder 1
When the current is applied to cooling bushing 2, contact bushing 4, contactor 7, and chuck 9
It flows to the left outer end (C) of the workpiece W, and then flows from this part to the right base end (E) of the workpiece W, and then reaches the other electrode 17.

As a result, the workpiece W is heated over time by the current-carrying resistance, and after being heated to a predetermined temperature for a predetermined time, the workpiece W is pressurized and compressed from the right end of the workpiece W to the left by a pressing mechanism (not shown), and the die 1
The second part expands and undergoes swaging processing.

In this case, a portion of the die holder 1 that is close to the current-carrying portion of the workpiece W is cooled via the cooling bush 2 by the cooling oil flowing through the cooling oil path 3 .

After the above molding, the piston 5-2 is moved to the left by the supply of hydraulic oil from the supply port 5-5, and the piston rod 5-3, connector 6, and contactor 7 are thereby moved to the left and taper. The hole 7a and the tapered surface 9b are separated, and the chuck 9
will be operated to open.

Next, the anvil 14 is moved to the right via the push rod 15, and the workpiece W is pushed out to the right.

(Effects of the invention) As is clear from the above explanation, in the present invention, the die holder side and the workpiece are crimped and connected at the outer periphery of the workpiece in the vicinity of the die where the workpiece is bulged. The contact area can be increased, and the energized parts of the workpiece can be concentrated in the parts required for molding.

Therefore, the present invention has the effect of being able to ensure a sufficient amount of current flow, reduce heat loss, and perform smooth current flow.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a side view of its main parts, FIG. 3 is a sectional view thereof, and FIG. 4 is a sectional view showing a conventional example. 1: Die holder, 2: Cooling bush, 2a:
Spiral wall, 3: Cooling oil path, 4: Contact bush, 5: Drive mechanism, 5-1: Cylinder, 5-
2: Piston, 5-3: Piston rod, 5-
4: Supply port, 5-5: Supply port, 6: Connector,
7: contactor, 7a: tapered hole, 8: split clamp, 9: chuck, 9a: left end, 9b:
Tapered surface, 9c:: slit, 9d: locking piece,
10: Reception ring, 11: Fitting hole, 12: Die,
13: retaining ring, 14: anvil, 15: push rod, 16: one electrode, 17: other electrode.

Claims (1)

[Scope of utility model registration request] A fitting hole into which a rod-shaped workpiece is fitted is formed in a die holder to which one electrode is connected, and an annular die and a chuck into which the workpiece is fitted into the fitting hole are arranged close to each other in the axial direction, The outer circumference of the chuck is formed into a tapered surface that widens toward the die direction, and the remaining large diameter side, leaving the small diameter side, is divided in the circumferential direction, and the chuck taper is formed in the fitting hole. 1. A workpiece contact device for an electrically heated forging machine, characterized in that an actuating body having a tapered hole that can be fitted into a surface is provided, and a drive mechanism for reciprocating the actuating body in an axial direction is provided.