JPS59130641A - Method and device for producing metallic bar having bulge at end - Google Patents

Abstract

PURPOSE:To enable efficient production of a desired metallic bar at a low cost with a simple device and constitution by grasping the metallic bar with two sets of electrodes arranged in the longitudinal direction thereof, conducting electricity to the electrodes and compressing longitudinally the bar material softened red hot. CONSTITUTION:Electrodes 3 grasping a metallic bar 2 between members 3a and 3b are provided apart from at some space from electrodes 1 grasping the bar 2 between members 1a and 1b. Electric current is conducted through the electrodes 1 and 2 to the bar 2 to soften red hot the bar. The end 2b of the bar is gradually extruded by advancing a pressing part 4 to bulge the bar 2 in the open space between the electrodes 1 and 3 to a spherical shape. A moving device 6 is then operated to drive the electrodes 1 so as to widen the space from the electrodes 3 and to grow the spherical bulge to the electrode 1 side, thereby forming a circular cylindrical bulge 2d. The bar 2 is grasped between rollers 5a and 5b provided freely loosely rotatably with the members 1a, 1b. The metallic bar having the highly mechanically strong bulge at the end is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to, for example, a guide rod or a protrusion of a molding die.
The present invention relates to a method and apparatus for manufacturing a metal rod having a bulge at its end, which is used as a push-out bottle or plan-v-, etc.

Conventionally, such metal residues having enlarged ends are produced by, for example, gripping a metal bar material with a pair of upper and lower dies, and pressing the end surface of the bar material with a punch driven in the length direction of the material. Using a press processing method such as upsetting in which the part is compressed and deformed within the cylindrical space of the upper and lower dies, or by using a relatively thick metal rod material with the same final diameter as the intended bulk part, the part other than the part that should be the bulk part is removed. It has been manufactured using a cutting method in which the outer periphery of the material is cut concentrically with the bulk portion to form a small diameter shaft.

However, since the enlarged end portion of the metal rod manufactured by the press working method is formed by compressive deformation, the metal structure is disordered, and the mechanical strength is not large9. When processing materials, the dies and punches put a lot of stress on them, which caused considerable wear and tear. In addition, when manufacturing by cutting, it took a long time for cutting to form the small diameter shaft portion, resulting in poor processing efficiency. Furthermore, since the metal bars used in die sronds and the like have extremely high hardness, it is necessary to use expensive carbide cutting tools, and the tools also wear out rapidly, resulting in high machining costs.

Therefore, it is an object of the present invention to
It is an object of the present invention to provide a method and an apparatus that can efficiently and economically produce a metal rod having an enlarged portion with high mechanical strength at its end.

The gist of the method of the present invention is that a metal bar material is sandwiched between a first member and a second member of a first electrode, and the metal bar material is held at an appropriate distance from the sandwiched portion by the first electrode. The metal bar material is sandwiched between a first member and a second member of the two electrodes to prevent the metal bar material from moving in the longitudinal direction, and then the first electrode,
After applying electricity to the metal rod material through a second electrode to make the metal rod material red-hot, one end side of the metal rod material is pressed toward the second electrode along its longitudinal direction, while the first 'f'
By gradually moving the ji pole so as to widen the distance between it and the second electrode, a cylindrical enlarged portion is formed on the outer periphery of the metal rod material between the first electrode and the second electrode. This is what I did.

Further, the gist of the device of the present invention is to provide a first electrode for sandwiching a metal rod material between a first member and a second member, and a first electrode for holding the metal rod material at an appropriate distance from a portion held by the first electrode. a second electrode sandwiching the metal rod between a first member and a second member; A pressing tool equipped on the first electrode side presses the metal bar material toward the two electrodes, and a pressing tool is attached to the first member and the second member of the first electrode to sandwich the metal bar material, and the metal bar material is When pressed by the suppressor and moved toward the second electrode, the 10th-ra and 20th-ra rotate and roll into contact with the metal rod material.
and a first electrode moving device that drives the first electrode so as to gradually widen the distance between the first electrode and the second electrode when the suppressor presses the red-hot metal rod material. 1
electrode.

A cylindrical enlarged portion is formed on the outer periphery of the metal rod material located between the second pole.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the present invention will be explained in detail based on the drawings of FIGS. 1 to 5. In the manufacturing apparatus of this example, the metal bar material 2, which has the same diameter as the shaft diameter of the target metal bar, has grooves A of the first member 1& of the 11f pole 1 and grooves B of the second member 1b. Sandwiched in between is Mizojo A.

The inner surface of B does not come into direct contact with the circumferential surface of the material 20 (see FIG. 4). The metal rod material 2 is inserted between the grooves C of the first member 3a and the grooves of the second member 3b of the second electrode 3 at an appropriate distance from the part held by the first electrode 1. They are directly gripped and fixed by the inner surfaces of each groove C and D (see Fig. 6). First electrode 1. A round bar-shaped pressing tool 4 that presses one end of the metal rod material 2, which has become red-hot by applying electricity through the second electrode 3, along its longitudinal direction toward the second electrode 3 moves toward the first electrode 1. freely equipped. The metal rod material 2 is held on the first electrode 1 side by the first
The metal bar material 2 is pressed by the pressing tool 4 by the grooved 10th lug 5a and the 20th lug 5b which are freely rotatably attached to the first member 1a and the second member 1b of the electrode 1. When moving toward the second electrode 3 side, the tenth lathe 5a and the twentieth lager 5b roll into contact with the metal rod material 2. In the first electrode 1 and the second electrode 3, the first member l a
*3 a is interlocked with each hydraulic or pneumatic operating cylinder 7.8, and the operation of the cylinder 7.8 moves the second members 1b and 3b up and down by a required stroke, and an appropriate positioning means or stopper is activated.・It is stopped and held at the material clamping position by the cooperation of the following. The drive device 9 of the suppressor 4 and the first electrode moving device 6 are similarly constructed of hydraulic cylinders. The first member 1a of the first electrode and the fluid pressure operation cylinder 7.9 are connected to the guide groove 1 of the identification base 10.
The hydraulic cylinder 6 is fixed to a movable machine frame 12 that moves linearly along a fixed base 0. The first member 3a of the second electrode and the fluid pressure operation cylinder 8
is fixed to a fixed machine frame 13 fixed to a fixed base 10. In the figure, 16 indicates each second member 11 of the first and second electrodes.
), 3b Gaitod. 13a is the second electrode 30
This is an insulating layer interposed at the base.

The first electrode 1 side of the metal rod material 2 is in the groove E of the roller 5a.
and the groove F of the 20th lug 5b (the 5th
), the tip 2a of the material 2 protruding from the second electrode 3 is
The metal rod slides along the straight groove 15 of the fixed frame 13 and comes into contact with a longitudinal length 14 for determining the length of the metal rod. 10th-ra 5 of the first electrode 1
a and the 20th line 5b are made of a conductor.

Thus, in the state shown in FIG. 1, when a current is passed through the metal rod material 2 through the first electrode and the second electrode 3, the metal rod material 2 becomes red hot and becomes soft.

When the temperature becomes moderate, the current is either stopped or the current is continued to the extent that it does not harden again, and the end 2b of the metal rod material 2 is gradually pushed out toward the second electrode 3 by driving the pressing tool 4. Then, the metal rod material 2 in the open space between the first electrode 1 and the second electrode 3 swells and becomes a spherical enlarged part 2c (
Figure 2). Here, the moving device 6 is operated while the pushing action by the pressing tool 4 is maintained, and gradually the first
When the electrode 1 is driven so as to widen the distance between it and the second electrode, the spherical enlarged portion 2c of the metal rod material 2 grows toward the first electrode 1 while keeping its diameter approximately, and forms a circle. A columnar enlarged portion 2d is formed (FIG. 3).

Therefore, the operations of the pressing tool 4 and the moving device 6 are stopped, the second members 1b and 3b of each electrode are moved upward to take out the metal bar product, and then the first electrode 1 is moved again by the moving device 6. υReturn to the original position, and the suppressor 4 is also returned to the original position, and another gold PA bar material is charged in the same way and manufactured one after another.

Note that the metal rod material 2 is pressed by the pressing tool 4 and the second pole 3
When moving to the side, the 10th-ra 5a and the 20th-ra
Since the rubber 5b rotates and rolls into contact with the metal rod material 2, the friction is very small, so that the red-hot and soft outer peripheral surface of the metal rod material 2 is not pulled and damaged.

Furthermore, the formation of the spherical enlarged portion 2C and the degree of growth thereof into the cylindrical enlarged portion 2d are influenced by the current value applied to the metal rod material 2, the pressing force of the pressing tool 4, and the speed of movement of the first electrode 1. Ru. Incidentally, as the metal bar material 2, either an unhardened material or a hardened material can be used.

The metal rod manufactured in this way, which has an enlarged portion at its end, can be used as a final product by being subjected to finishing treatment such as plating as it is, but if necessary, it can be used as a final product as shown in Figure 9. The tip of the cylindrical expanded portion 2d that continues to the unexpanded material end 2b and the expanded portion 2d that continues to the small diameter rod body.
The final product is finished by cutting the base end or the very surface layer of the outer peripheral surface of the thick carved part 2d.

As described above, according to the present invention, the cylindrical enlarged portion 2d is formed by compressing the metal rod material 2 in the length direction while softening it by energizing it, and therefore Compared to metal bullet products obtained by the Solenne processing method using intermittent compression deformation, it has an excellent tissue structure and high mechanical strength. In addition, in the conventional upsetting process in which a hard material is compressed and deformed in a closed space, wear and tear on dies, punches, etc. cannot be ignored, but in the present invention, as described above, a soft material is compressed and deformed in an open space. , 1st
No excessive force is applied to the V-pole or the second electrode, and wear and tear on these parts can be almost ignored. Furthermore, even if the base end and outer peripheral surface layer of the cylindrical enlarged portion 2d are cut as necessary,
The amount of cutting required for this finishing process is extremely small compared to cutting a small-diameter bar body from a large-diameter metal bar material1, and the work time required for finishing process is short and the labor burden is small. . Furthermore, wear and tear on the cutting tool is reduced, and its useful life can be extended.

As described above, according to the present invention, a metal rod having an enlarged portion with high mechanical strength at the end can be manufactured efficiently and at low cost using a relatively simple method and apparatus.

Note that the present invention is not limited to the above embodiments, and for example, as shown in Figure 7 and Stripe 8, each of the first members 1 a r 3 a of the first electrode l and the second electrode 3 The second members 1b and 3b may also be arranged vertically. Also,
Not only the 1' polarization 1 but also the second electrode 3 is provided with a suppressor, a pair of rollers, a moving device, etc., and both of the pressers press the red-hot metal rod material, and the two electrodes are mutually connected. They may be simultaneously moved in a direction in which the distance between them increases, and in this way, a cylindrical enlarged portion can be formed in an even shorter time. Furthermore, if the metal rod material 2 is rotated together with the electrode 1.3 when forming the ampulla, a longer cylindrical ampullae can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional front view of a manufacturing apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing the operating process, and FIG. 4 is an N-IV diagram of FIG. 1. Figure 5 is a cross-sectional view along the v-v' line in Figure 1, Figure 6 is the vt in Figure 1.
7 and 8 are longitudinal sectional views of the first electrode in other embodiments of the present invention, and FIG. 9 (a) is a front view of the end of the metal rod, and the figure (→ is a front view of the end of this material after finishing cutting. 1... First electrode, 1a... First member, 1b... Second member, 2... Metal bar material, 3...・Second electrode, 3a
... first member, 3b... second member, 4... pressing tool, 5a... first roller, 5b... 20th-ra, 6...
...Jth electrode moving device 0 paper 140 etc. evening picture 6 ￥9121 231-

Claims (2)

[Claims] (1) While a metal rod material is sandwiched between the first member and the second member of the first electrode, the metal rod material is placed at a suitable distance from the portion held by the first electrode. The metal bar material is sandwiched between the first member and the second member of the pole to prevent the metal bar material from moving in the longitudinal direction, and then electricity is applied to the metal bar material through the first electrode and the second electrode to remove the metal bar material. After the material is heated to red heat, one end of the metal bar material is heated along the longitudinal direction of the second material.
By gradually moving the first electrode so as to widen the distance between it and the second electrode while pressing toward the electrode, a circle is formed on the outer periphery of the metal bar material between the first electrode and the second electrode. A method for manufacturing a metal rod having an enlarged portion at an end, the method forming a columnar enlarged portion. (2) A first electrode that sandwiches the metal bar material between the first member and the second member, and a portion held by the first electrode) between the first member and the metal bar material at an appropriate distance. The 2nd part is held between the two members! is installed on the first electrode side, and presses one end side of the metal bar material, which becomes red hot due to electricity passing through the pole, the first electrode, and the second electrode, toward the second electrode along its longitudinal direction. The pressed tool is attached to the first and second members of the electrode to clamp the metal rod material, and the metal rod material is pressed by the pressing tool and the metal rod material is pressed against the second electrode.
When moving to the pole side, the 10th and 20th la rotate and make nine contact with the metal rod material, and when the pressing tool presses the red-hot metal rod material, a first electrode moving device that drives the first electrode so as to gradually widen the distance between the first electrode and the 211f pole; An apparatus for manufacturing a metal rod having an enlarged portion at its end.