JP4965312B2 - Energizing upsetter method and apparatus - Google Patents

Description

  The present invention relates to the field of an energizing upsetter method and apparatus for molding a stopper portion on the outer periphery of a parking rod when a parking lock cam is attached to the parking rod.

  2. Description of the Related Art Conventionally, a vehicle automatic transmission has a built-in device that locks a vehicle by swinging a parking pole and engaging a pawl of the parking pole with a parking gear provided on a drive shaft. This parking lock device mechanically locks the drive wheels so that the vehicle does not move when the shift lever is operated to the parking range (see Patent Document 1).

A stopper part for positioning the parking lock cam is attached to the parking rod constituting one part of the parking lock device.
6A and 6B show an example when a stopper part is inserted into a parking rod and attached to a rod outer peripheral surface at a predetermined position by a conventional method.

The parking rod 51 is, for example, a round bar material made of mild steel. The length is about 260 to 280 mm and the outer diameter is about 7 to 8 mm.
The stopper part 52 has an outer diameter of about 10 mm and is larger than the outer diameter of the parking rod. The length is about 7 to 8 mm, and the overall shape of the part is conical. A through hole 53 having a diameter of about 8 to 9 mm is formed in the stopper component 52 in the axial direction, and a parking rod 51 is inserted into the through hole 53 and fixed at a predetermined position.

  As shown in FIG. 6A, a taper surface 55 is formed which gradually decreases in thickness from a large diameter portion 54 having a contact surface formed at the rear portion to a small diameter portion at the tip and is inclined in a conical shape. The conical stopper part 52 has a small diameter end joined to the outer periphery of the parking rod by arc welding.

FIG. 7 is a part view partially showing a structural example of a conventional product composed of a parking rod, a stopper part, a parking lock cam, and a compression coil spring.
The stopper part 52 literally stops the parking lock cam 56 that swings the outer periphery of the parking rod 51 at a predetermined position.

  In this case, the compression coil spring 57 is inserted between the lock cam 56 and the locking portion (not shown), and the cylindrical tip 58 of the parking lock cam 56 receives the elastic force of the compression coil spring 57 and always comes into contact with the stopper 52 with a large diameter. The flat surface of the portion 54 is pressed.

The parking rod 51 and the stopper part 52 are conventionally configured as separate parts as separate parts, and arc welding has generally been used for assembling the single parts as described above.
JP-A-7-137555

  When assembling the parking rod and the stopper, arc welding equipment has been used. However, the problem in this case is that the influence of arc heat is large and irregularities and steps are generated on the surface of the welded part. It takes a lot of work and is difficult to manufacture at a low cost because of the large number of parts.

Furthermore, the energizing upsetter device according to claim 1 of the present invention includes the following.
A first electrode that clamps one of the regions with a predetermined clamping interval in the vicinity of the region where the stopper portion of the rod-shaped material is formed;
A second electrode for clamping the other side of the region corresponding to the electrode;
A pressure mechanism that relatively moves at least one of the electrodes to generate an upset force necessary in the axial direction of the rod-shaped material,
The first electrode has at least a divided portion;
In addition, a clamp and electrode surface having a concave curved cross section that is in axial contact with the outer peripheral surface of the rod-shaped material is formed on the two facing divided surfaces.
The split electrode on one side moves in a direction perpendicular to the axis of the rod-shaped material with respect to the other split electrode, thereby performing an opening / closing operation necessary for clamping and unclamping the rod-shaped material,
The second electrode corresponding to the first electrode is integrally formed with an upset groove for forming the stopper portion, and the upset groove has a cross section substantially the same shape as the outer peripheral surface of the stopper portion. None and having a volume substantially equal to the stopper portion,
Moreover, the upsetting groove is provided with a communication hole opened in the axial direction of the rod-shaped material,
The communication hole is divided into at least two, and the dividing direction is the axial direction of the rod-shaped material,
In addition, the two divided divided surfaces are formed with a substantially concave curved clamp and electrode surface that matches the shape of the outer peripheral surface of the rod-shaped material and contacts in the axial direction.
In the first electrode and the second electrode, at least one of the divided electrodes is driven in a direction substantially perpendicular to the axis of the rod-shaped material, and the rod-shaped material is clamped and unclamped with the other divided electrode. The opening / closing operation necessary for the operation is performed.

The energizing upsetter device according to claim 2 of the present invention includes:
In the first electrode and the second electrode, the upper and lower limits of the gap formed between the divided electrodes when the rod-shaped material is clamped from both sides are set to 0.1 mm or more and less than 0.6 mm.

The energizing upsetter device according to claim 3 of the present invention comprises:
After forming a stopper portion that is plastically deformed in the upsetting groove and projecting to the outer periphery of the material, a mechanical high pressure is generated in the axial direction of the rod-shaped material, whereby the material including the stopper portion is Ejecting means for separating from the electrode is provided.

The present invention is compared with a conventional method and apparatus for assembling a single part of a parking rod and a parking lock cam integrally by arc welding, and has a length necessary for forming a stopper portion in advance from a single metal rod-shaped material. By preparing a rod-shaped material, it is possible to plastically process the stopper on the outer periphery of the parking rod in a short time due to resistance heat generation, so the number of parking lock cam parts and the number of processing steps can be reduced.
In other words, since it can be easily molded from a single soft steel round bar using resistance heat generation, the yield of the material is good, the number of manufacturing steps, the number of parts, the equipment cost, etc. can be reduced, and the cost can be greatly reduced.
In addition, it is possible to reduce the unevenness and level difference that occur in the conventional welded part by integrally installing upsetting grooves having a volume approximately equal to the outer shape of the stopper part for the lock cam on one of the electrodes, increasing the quality and mechanical strength and durability. Will also improve.
Further, if the final setting amount of the axial gap formed between the first electrode and the second electrode at the time of upsetting is narrowed to about 1.5 mm, the outer peripheral surface of the material is set within the upsetting groove region. Since the wall thickness of the bulging stopper portion can be compressed flat from the axial direction, a stopper portion with a smooth and natural finish can be made without any burrs in the large diameter portion 54 of the stopper portion.

  The present invention is realized by an energizing upsetter device for forming a stopper portion on the outer periphery of the parking rod when the parking lock cam is attached to the parking rod.

The present invention is an energizing upsetter method and apparatus for molding a parking lock cam stopper 51a on the outer periphery of the parking rod 51 shown in FIGS.
FIG. 1 shows an apparatus for carrying out the method of the present invention.
FIG. 2 is a cross-sectional view of the second electrode taken along the line XX of FIG.
FIG. 3 is a schematic view for explaining a section and operation of an apparatus for carrying out the method of the present invention.
FIG. 4 is a workpiece view after energization upsetter molding by the method and apparatus of the present invention. FIG. 4A shows a conical stopper portion, and FIG. 4B shows a cylindrical stopper portion.
FIG. 5 shows an operation flowchart of the present invention.

  In this case, the parking rod is indicated by a round bar 50 made of a mild steel material. The parking rod and the stopper portion are integrally formed from this single material. In particular, the stopper portion is softened by resistance heat generation and molded by compression within a constant volume.

  As shown in FIGS. 1 to 4, the upsetter device 10 of the present invention has a first electrode 1 and the other second electrode 2 disposed between them, and as a power welding unit for energization between these pair of electrodes, like a resistance welding machine. A transformer is connected, and between the transformer and the main power source, a control device including a power source control unit having a timer unit and a contactor unit for controlling the current value and energization time of the energization transformer is connected.

  This control device has a built-in setting unit for setting the CPU and the current value, energization time, upset force and other control elements necessary for upset processing, and the sequence program required for upset processing is stored mechanically or It is executed by various electrical operations.

  The pressurizing mechanism is generally a cylinder and is arranged on at least one of the electrodes. The sequence program is used to open and close the electromagnetic valve and move the distance between the other electrodes to generate the pressure applied to the upsetter. is there.

  In this case, a cylinder (fluid pressure system) is generally used, but an actuator such as an electric motor may also be used.

  The second electrode 2 is integrally and three-dimensionally formed with an upright groove 3 having a concave cross section, and this upset groove 3 is an inner peripheral surface substantially conforming to the conical outer peripheral shape of the stopper portion 50a. Thus, a volume substantially equal to the size of the stopper portion 50a can be accommodated.

  The rod-shaped material is clamped and held between the first electrode 1 and the other second electrode 2 with a predetermined clamp interval E. The predetermined clamping interval E between the electrodes 1 and 2 is set as an upset allowance (dimension) by a compression movement distance corresponding to a stopper portion volume in a region where the stopper portion 50a is formed.

  When a current is passed between the electrodes and the upset margin is heated and softened by the resistance heat generation, the stopper 50a is softened by pressing the rod-shaped material 50 held by the clamp in the axial direction A, Thereby, the rod-shaped material 50 is compressed while moving.

During this process, the stopper portion 50a that the upset margin swells in the upsetting groove 3 and protrudes to the outer periphery of the material is plastic molded.
In this case, when the distance e between the electrodes 1 and 2 is less than 0 mm, the flat portion is not molded. On the other hand, if the distance e exceeds 2.0 mm, the bulge of the stopper portion protrudes greatly and the outer diameter accuracy of the outer peripheral surface of the stopper portion cannot be maintained.

Next, the electrode structure of the upsetter device of the present invention will be described in detail.
The upsetter device 10 includes a first electrode 1 that clamps at a predetermined clamping interval E near one side outside the region where the stopper portion 50a of the rod-shaped material 50 is formed.
A second electrode 2 corresponding to the electrode and clamping the vicinity outside the region on the other side;
At least one of these electrodes has a pressurizing mechanism 4 that generates a pressing force necessary for upset molding in the axial direction of the rod-shaped material.

In this embodiment, the first electrode 1 is divided into at least two, and the divided electrodes 1a and 1b divided into two are clamps having a concave curved surface substantially matching the curved surface shape of the outer peripheral surface of the rod-shaped material 50. The cum electrode surfaces 1c and 1d are formed.
The concave curved surface of the electrode is in curved contact with the axial outer peripheral surface of the rod-shaped material.

The curved shapes of the clamp and electrode surfaces 1c and 1d of the first electrode 1 are the same as the curved shapes of the clamp and electrode surfaces 2c and 2d of the second electrode shown in the cross section of FIG.
The divided electrode 1a on one side moves the electrode support base 9 in a direction perpendicular to the axis yy of the rod-shaped material 50, that is, in the direction of the arrow ab, and clamps the rod-shaped material 50 against the other divided electrode 1b. The opening / closing operation required for unclamping is performed by being connected to a drive source (not shown) such as a cylinder or an electric motor.

On the other hand, an upset groove 3 for forming the stopper portion 50a is formed in the second electrode 2 integrally with the electrode.
The upsetting groove 3 has a three-dimensional concave section that is substantially the same in shape as the stopper portion 50a and accommodates a volume substantially equal to that of the stopper portion 50a.
A communication hole 5 for communicating the rod-shaped material 50 in the axis yy direction is formed in the upsetting groove 3.

  The communication groove 5 and the axial clamp groove 6 communicate with each other as they are, and clamp a part of the material outside the region forming the stopper portion 50a in the axial direction. The clamp groove 6 is divided into two at least in the axis yy direction (longitudinal direction) of the rod-shaped material 50 as in the first electrode 1.

  As shown in FIG. 2, clamped and electrode surfaces 2c and 2d having a concave curved cross section that are in contact with the outer peripheral surface of the rod-shaped material 50 and contact in the axial direction are formed on the two opposed electrode surfaces. ing.

  The split electrode 2a on one side opens and closes in a direction (arrow cd in the figure) perpendicular to the axis yy of the rod-shaped material, and clamps the rod-shaped material 50 on the other one-side electrode 2b. And the operation necessary for unclamping is performed.

  The structure of the divided electrode 2a of the second electrode 2 can also be applied to the first electrode 1. In this case, a communication hole 5 for communicating the rod-shaped material 50 in the direction of the axis yy is formed integrally with the first electrode 1, and a part (front or rear) of the communication hole is formed on the second electrode 2. Similarly to the split electrode 2a on one side, the drive cylinder is separated so as to open and close in the direction (arrow ab in the figure) where the split electrode intersects at right angles to the axis yy of the rod-shaped material. It is possible to clamp and hold a part of the material outside the region for forming the stopper portion 50a by using the above.

  Further, as shown in FIG. 2, the energizing upsetter 10 has a gap h dimension of 0.2 mm or less between the divided electrodes in the lateral direction when the rod-shaped material 50 is clamped and held by the first electrode 1 and the second electrode 2. By controlling, it is possible to reduce the adhesion of the protrusions that are enlarged on the stopper flat surface that projects to the outer periphery of the material 50 by the set amount of the gap h between the electrodes.

  In this case, if the gap h between the divided electrodes is less than 0.1 mm, the clamping force is insufficient and the contact surface affects the sliding accuracy. Further, when the gap h dimension between the divided electrodes is 0.6 mm or more, a protruding bulge is generated in the flat portion, and the quality is deteriorated.

  The operational effect of the energizing upsetter method and apparatus of the present invention was confirmed based on the following condition values.

(1) Upset condition Electrode pressure: 8.0 kN, Energizing time: 60 cycles (including 10 upslope cycles), Energizing current: 6.7 kA, Clamp interval: 6.3 mm, Upsetter final interval: 1.5 mm Material of one electrode and second electrode: Chrome copper (CrCu)

(2) Material and shape of parking rod and stopper part Bar material: S35C, outer diameter: 7.08 mm, length: 280 mm, conical stopper part: length 9.5 mm, large diameter outer diameter: 10.2 mm , Small diameter part outer diameter: 9mm

  As a result of an experiment using the above experimental values as an example, it was confirmed that a stopper part that has no problem in accuracy and function can be directly molded from a single rod-shaped material to the outer periphery of the parking rod by utilizing the resistance heat generated by the energizing upsetter. .

  The operation of the apparatus of the present invention based on the above experimental values will be described with reference to the operation flowchart shown in FIG. 5. A rod-shaped material 50 having a prescribed size in which a parking rod and a stopper portion are formed from one soft steel round bar is prepared in advance. .

The opposing clamp interval E between the first electrode 1 and the second electrode 2 is set to a distance corresponding to the allowance for forming the stopper portion 50a.
When the first electrode 1 and the other second electrode 2 are in the return position, the left divided electrodes 1a and 2a shown in FIGS. 1 to 3 are on the left (arrows a and c in the figure). The electrode is waiting in the open position.

step 1
When the rod-shaped material 50 is set in the upsetter device, it is inserted into the upsetting groove 3 of the second electrode 2 in the vertical direction (similar to the axis yy direction in the figure) manually or by robot handling (not shown).

  In this case, the rod-shaped material 50 is inserted into the communication hole 5 and the clamp groove 6 that pass through the upsetting groove 3 integrated with the second electrode 2 and directly below this. In this case, the divided electrode 2a moves leftward and is open.

  The rod-shaped material 50 inserted into the upsetting groove 3 of the second electrode 2 is clamped and held so that the clamp / electrode surface 2c of the two divided electrodes and the concave concave surface of the clamp / electrode surface 2d match the shape of the material outer peripheral surface. The

Step 2
Next, when the pressurized mechanism 4 in the open state is operated and the compressed air injected into the return side air chamber of the air cylinder is discharged, the cylinder rod descends by its own weight such as the first electrode 1, the electrode support base 9, and the movable ram. The stopper surface of the electrode support at the tip of the cylinder rod comes into contact with the upper end of the rod-shaped material, and the rod-shaped material is pressed in the axial direction with a low pressure.

  When a low pressure is applied due to the weight of the cylinder, the lower end of the rod-shaped material 50 comes into contact with the stopper surface of the electrode base 7 and is positioned between the rod upper end and the rod lower end of the rod-shaped material 50 and a predetermined clamp interval E is set. The

  Next, the segment electrode 1a of the first electrode 1 is moved to the right (arrow b in the figure) to firmly clamp the stopper portion region of the rod-shaped material, and the positioning of the rod-shaped material is completed.

  The rod-shaped material 50 thus positioned is divided into divided electrodes 1a and 2a when the movable divided electrodes 1a and 2a of the first electrode 1 and the second electrode 2 are driven to the right (arrows b and d in the figure) by the drive cylinders. An upset allowance corresponding to the volume of the conical stopper portion, that is, a clamp interval E, is set in the stopper portion region by the divided electrodes 1b and 2b on the fixed side and 1a and 2a. The accurate upset cost is securely held by the clamp and the setting is completed.

Step 3
Thus, when the start switch is turned on, the start signal is transmitted to the control device, and the port of the electromagnetic valve of the pressurizing mechanism 4 is switched by the signal transmitted from the control device, and the high pressurizing operation is started in the air cylinder.

Step 4
Next, an ignition signal is input from the power supply control unit to an electronic switch such as a thyristor in the contactor unit, a large current is supplied to the primary circuit of the energizing transformer, and a predetermined upset current that is voltage-converted by the energizing transformer is a secondary circuit of the energizing transformer. Is supplied to the stopper portion region of the rod-shaped material 50 through the first electrode 1 and the second electrode 2 for a predetermined time.

Step 5
Meanwhile, the stopper molding region is heated to a predetermined temperature, for example, an iron softening temperature of 800 degrees by resistance heat generation.

Step 6
When the stopper portion molding region is gradually heated, a high pressure is applied in the axial direction A of the rod-shaped material 50, and the material is compressed in the upsetting groove 3 while being moved to the upset allowance, and the plastic deformation is used to utilize the material. A conical stopper portion 50a extending to the outer periphery is upset.

  In this case, when the first electrode 1 and the second electrode 2 at the time of upsetting the final electrode tip gap reaches a set range of, for example, about 1.5 mm, the displacement during this electrode movement In the case of an air cylinder, the pressurization movement of the pressurization mechanism is stopped by checking with a position sensor or by checking the energization time corresponding to the heat capacity.

  When the pressurization mechanism is a mechanical system of servo motor, ball screw, and nut, the speed of the servo motor, such as an encoder, is controlled and positioned by a position sensor using digital control means.

Step 7
When the upset final position is reached, an energization stop signal is sent to the power control unit to cut off the upset current. These operations are controlled by a sequence program on the CPU.

  In this way, the final axial gap e formed between the first electrode 1 and the second electrode 2 at the time of upsetting is narrowed, so that the stopper 50a that swells in the region of the upsetting groove 3 is contacted. The contact surface 50b is compression-molded flat, and the function as the stopper portion 50a is sufficiently obtained.

Step 8
Thus, when the upsetting of the stopper portion of the rod-shaped material is completed, an opening signal is sent from the power control unit to the electromagnetic valve of the air cylinder that drives the divided electrode 2a of the second electrode 2, and the point is cut to unclamp (open port). Instead, the opening operation is started.

  Next, the air cylinder of the pressurizing mechanism 4 starts to be opened, and the divided electrode 1a of the first electrode 1 starts to unclamp, so that the rod-shaped material after the upsetting can be taken out.

Step 9
Thus, one cycle of upsetter molding is completed, and thereafter the same operation is repeated.

  When the ejecting operation is performed using the ejecting device 8, a stopper portion 50 a that is plastically deformed in the upsetting groove 3 and projecting to the outer periphery of the material is molded, and then the tip of the rod-shaped material 50 is directly below the electrode base 7. Thus, the rod is automatically projected in the direction of the axis yy of the rod-shaped material 50, and for this purpose, the processed material can be extracted from the upsetting groove 3.

  In this embodiment, the upsetter device 10 is upset in the axial direction A of the rod-shaped material 50 by the pressurizing mechanism 4 in the same direction as the attractive direction with respect to the ground. The upset force in the axial direction of the rod-shaped material can be applied horizontally from both sides of the first electrode and the second electrode, and the structure of the upsetter device can be reduced in size. In addition, the supply and unloading of workpieces can be automated.

  Further, in this embodiment, since the ejecting device 8 is disposed on the electrode base 7 at a position to receive the tip of the rod-shaped material 50 in the axis yy direction, even if the stopper portion 50a bites into the upsetting groove 3 after energization, the axis y Can be easily pulled out in the -y direction.

  The ejecting device 8 is formed by forming a stopper portion 50a that is plastically deformed in the upsetting groove 3 and projecting to the outer periphery of the material, and then the tip of the rod-shaped material 50 is moved from right below the electrode base 7 to the axis yy of the rod-shaped material 50. The rod is automatically protruded in the direction, whereby the processed material can be extracted from the upsetting groove 3.

The ejector device 8 is a mechanical elevating mechanism, and an actuator such as a cylinder or an electric motor is used as a drive source thereof.
Further, productivity is doubled if the means for ejecting after the opening / closing drive of the electrode and the energization is an automatic process.

  The present invention is compared with a conventional method and apparatus for assembling a single part of a parking rod and a parking lock cam integrally by arc welding, and has a length necessary for forming a stopper portion in advance from a single metal rod-shaped material. By preparing a rod-shaped material, it is possible to plastically process the stopper on the outer periphery of the parking rod in a short time due to resistance heat generation, so the number of parking lock cam parts and the number of processing steps can be reduced.

  In other words, since it can be easily molded from a single soft steel round bar using resistance heat generation, the yield of the material is good, the number of manufacturing steps, the number of parts, the equipment cost, etc. can be reduced, and the cost can be greatly reduced.

  In addition, it is possible to reduce the unevenness and level difference that occur in the conventional welded part by integrally installing upsetting grooves having a volume approximately equal to the outer shape of the stopper part for the lock cam on one of the electrodes, increasing the quality and mechanical strength and durability. Will also improve.

  Further, a stopper portion that swells on the outer peripheral surface of the material in the region of the upsetting groove by narrowing the final axial gap formed between the first electrode and the second electrode during upsetting to about 1.5 mm. Since the wall thickness of the stopper can be flatly compressed from the axial direction, a stopper portion having a smooth and natural finish can be made without a burr in the large diameter portion 54 of the stopper portion.

  In the embodiment of the present invention, the upsetter processing of the conical stopper part of the parking lock device has been described. However, the present invention is not limited to this field, and can be applied to processing of parts for different purposes from a single metal rod-like material.

1 is an apparatus for carrying out the method of the present invention. It is sectional drawing of a 2nd electrode by the arrow XX of FIG. It is the schematic for the cross section of apparatus for enforcing the method of this invention, and operation | movement description. FIG. 4A shows a conical stopper portion, and FIG. B shows a cylindrical stopper portion in a work drawing after energization upsetter molding by the method and apparatus of the present invention. The operation | movement flowchart of this invention is shown. It is explanatory drawing which shows the conventional method. FIG. 6 is a partial view showing a structural example according to a conventional method including a parking rod, a stopper part, a parking lock cam, and a compression coil spring.

Explanation of symbols

1 First electrode 1a, 1b Split electrode
2 Second electrode 2a, 2b Split electrode 3 Upset groove 4 Pressurization mechanism 5 Communication hole 6 Clamp groove 7 Electrode base 8 Ejecting device 10 Current applicator device 50 Bar-shaped material 50a Stopper portion 50b Abutting portion 51 Parking rod 52 Stopper component 53 Through-hole 54 Large-diameter portion 55 Tapered surface 56 Parking lock cam 57 Compression coil spring 58 Cylindrical tip A Rod-shaped material axial direction E Clamp interval (upset allowance)
e Electrode upsetter final interval h Clearance between split electrodes y Axis

Claims (3)

The energizing upsetter device
A first electrode that clamps one of the regions with a predetermined clamping interval in the vicinity of the region that forms the stopper portion of the rod-shaped material;
A second electrode for clamping the other side of the region corresponding to the electrode;
A pressure mechanism that relatively moves at least one of the electrodes to generate an upset force necessary in the axial direction of the rod-shaped material,
The first electrode has at least a divided portion;
In addition, a clamp and electrode surface having a concave curved cross section that is in axial contact with the outer peripheral surface of the rod-shaped material is formed on the two facing divided surfaces.
The split electrode on one side moves in a direction perpendicular to the axis of the rod-shaped material with respect to the other split electrode, thereby performing an opening / closing operation necessary for clamping and unclamping the rod-shaped material,
The second electrode corresponding to the first electrode is integrally formed with an upset groove for forming the stopper portion, and the upset groove has a cross section substantially the same shape as the outer peripheral surface of the stopper portion. None and having a volume substantially equal to the stopper portion,
Moreover, the upsetting groove is provided with a communication hole opened in the axial direction of the rod-shaped material,
The communication hole is divided into at least two, and the dividing direction is the axial direction of the rod-shaped material,
In addition, the two divided facing surfaces are formed with a clamp and electrode surface having a concave cross-sectional surface that matches the shape of the outer peripheral surface of the rod-shaped material and contacts the axial direction.
In the first electrode and the second electrode, at least one of the divided electrodes is driven in a direction substantially perpendicular to the axis of the rod-shaped material, and the rod-shaped material is clamped and unclamped with the other divided electrode. The opening / closing operation necessary for the operation is performed. The energizing upsetter device according to claim 1 ,
In the first electrode and the second electrode, the upper and lower limits of the gap formed between the divided electrodes when the rod-shaped material is clamped from both sides are set to 0.1 mm or more and less than 0.6 mm. In the energizing upsetter device according to claim 1 or 2 ,
After forming a stopper portion that is plastically deformed in the upsetting groove and protrudes to the outer periphery of the material, a mechanical high pressure is generated in the axial direction of the rod-shaped material,
Thus, an ejecting means for separating the material including the stopper portion from the electrode is provided.

Images