JP3546379B2 - Multistage forging machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is directed to a multi-stage press forming machine that sequentially press-forms a material from coarse to fine with a plurality of dies arranged side by side in a die block and a punch that moves forward and backward in opposition to the dies. The present invention relates to a multi-stage press forming machine in which a stamp is formed on the side surface of a molded product simultaneously with the press forming.
[0002]
[Prior art]
In a multi-stage press forming machine that forms bolts, nuts, and other various parts, a plurality of dies arranged side by side in a die block, and these dies are arranged to face each other, It has a plurality of punches to be moved forward and backward, and is configured so as to obtain a molded product of a predetermined shape by continuously forging raw material supplied sequentially between each corresponding die and punch from coarse to fine. ing.
[0003]
On the other hand, a molded product molded by this type of molding machine may have various types of identification marks engraved on its side surface. This is engraved by pressing a stamping punch on the side of the molded product.In this case, the punch must be pressed in a direction perpendicular to the axial direction of the molded product. Cannot do this engraving. Therefore, in the related art, the engraving process of the engraving is actually performed separately by a dedicated engraving machine or the like after forming the molded product by the multi-stage press forming machine.
[0004]
By the way, after forming a molded product as described above, when engraving a stamp on a side surface thereof, a stamping machine for engraving and a molded product obtained by a multi-stage press forming machine are supplied to the stamping machine. A supply device is required, and the equipment becomes complicated and large-scale, and there is a problem that time loss is increased. In addition, according to the stamping machine, there is a problem that swelling due to driving around the stamped characters and marks, burrs due to the cutting, and the like occur, and it is not possible to form a smooth surface.
[0005]
Accordingly, the present invention provides a method for engraving a stamp on a side surface of a molded article, which can be performed simultaneously with the forging of a product without providing a separate stamping machine, and further, has a smooth surface without swelling or burrs. It is an object of the present invention to provide a multi-stage press forming machine which can form an engraved mark and does not increase the size of the entire forming machine.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of claim 1 of the present application provides a method in which a plurality of dies arranged side by side in a die block and a plurality of punches which move forward and backward in opposition to the dies successively change the material from coarse to fine. In a multi-stage die forging machine that is designed to be forged in a specific manner, a specific die among the above-mentioned plurality of dies is provided to be able to advance and retreat in the axial direction with respect to a die holder, and the die is always set by a first spring. A stepped hole which is urged toward the punch side and pushes the die in the retreating direction against the first spring when the punch is advanced, while a stepped hole is opened in the side of the die to the inner side surface of the material storage recess . parts to form a comprises retractably head with stamping punch facing the inside concave tip into the hole portion from the hole portion in a direction perpendicular to the axial direction of the die, and its head a該刻mark punch after the second spring interposed between the parts and the hole of the step portion Direction, the head is normally projected radially outward from the die, and the stamping punch head is projected outward on the inner peripheral surface of the die holder when the die is advanced. When the die retreats, the head of the stamping punch is pushed into the hole against the second spring, and a guide portion having a tapered surface for projecting the tip portion from the hole into the concave portion of the die is formed. The feature is that it is provided.
[0007]
Further, according to the invention described in claim 2 of the present application, in the invention described in claim 1 described above, a fixing pin for punching is provided at the center of the die, and between the fixing pin and the die, A stripper for extruding the formed intermediate molded product or the final molded product to the outside is provided so as to be able to advance and retreat.
[0008]
In addition, the material storage recess is a concept including a polygonal, circular, or irregular shaped through-hole or recess.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 schematically illustrates a multi-stage press forming machine according to the present invention. As shown in FIG. 1, the press forming machine 1 includes a die block 3 fixed to a machine base 2 and a front surface of the die block 3. And a ram 4 that moves forward and backward with respect to the die block 3. The die block 3 is provided with dies 7a to 7d in which a plurality of dies 5a to 5d are mounted on the front end surfaces of the die holders 6a to 6d from coarse to fine, respectively. At one end, a cutter mechanism 8 for cutting a wire (not shown) supplied from a rear portion into a predetermined size is provided. On the other hand, the ram 4 is provided with punches 9a to 9d opposed to the dies 7a to 7d, respectively. These dies 7a to 7d and punches 9a to 9d form first to fourth forging stations A to D. The cutting material supplied from the cutter mechanism 8 is formed by the advancement of the ram 4 by each forging. In the stations A to D, forging is performed from rough to fine in order to obtain a molded product having a predetermined shape. Further, the machine base 2 is provided with a material transfer device (not shown) for transferring the cut material over the respective forging stations A to D.
[0010]
Here, the configurations of the mold 7d and the punch 9d in the final forging station will be described in more detail with reference to FIG.
[0011]
A die 7d is mounted on the die block 3 as described above. The die 7d is provided with a die holder 6d fixed to the die block 3 and a die 5d provided on the die holder 6d so as to be able to advance and retreat in the axial direction. The die 5d is normally urged by the first spring 12 toward the punch 9d. A guide sleeve 14 is arranged behind the die holder 6d via a spacer 13.
[0012]
A fixing pin 15 for punching, whose front end protrudes into the die 5d through the stepped hollow portion 6d 'of the die holder 6d, is fixed to the front surface of the spacer 13 using a holding member 16. . On this fixing pin 15, a cylindrical stripper 17 whose front end is also inserted into the die 5d is slidably fitted and held. A knockout pin 18 is slidably fitted in the guide sleeve 14, and the spacer 13 and the holding member 16 slide between the front end surface of the pin 18 and the rear surface of the stripper 17. A plurality of push rods 21 movably inserted and held are interposed, and when the knockout pin 18 advances, the push rod 21 and the stripper 17 are pushed out to the front end position.
[0013]
On the other hand, a punch holder 22 is fixed to the ram 4, a punch case 23 is fitted and fixed in the holder 22, and the punch 9 d is fitted and held at a front portion of the case 23.
[0014]
The die 7d in the final forging station D configured as described above is provided with an engraving mechanism 24 for engraving the engraving in conjunction with the forging operation.
In the marking mechanism 24, a die 5d is provided in a stepped hollow portion 6d 'in a die holder 6d so as to be able to advance and retreat in the axial direction, and the die 5d is interposed between the die 5d and the holding member 16. The first spring 12 is normally urged toward the punch 9d side, and when the punch 9d advances into the die 5d, the die 5d is pushed in the retreating direction against the first spring 12 via the intermediate molded product. It has been made to be. On the other hand, on the side of the die 5d, there is formed a stepped hole 5d "which opens to the inner side surface of the material storage recess (hexagonal through hole) 5d '. There is provided a stamping punch 25 facing the inside of the recess 5d 'from the hole 5d''so as to be able to advance and retreat in a direction perpendicular to the axial direction of the die 5d. Here, the die 5d is constituted by two split dies 50d 'and 50d "and integrated with each other. The engraving punch 25 has a head 25a at one end, and has a head 25a at the other end. Surface) is provided with an engraved pattern 25b such as a character or a mark, and between the head 25a of the engraved punch 25 and the step of the hole 5d ″, the punch 25 is always biased in the backward direction. Two springs 26 are interposed. A concave groove 6d "is formed in the lower part of the inner peripheral surface on the tip side of the die holder 6d. When the die 5d advances, the head 25a of the stamping punch 25 projects outward from the die 5d when the die 5d advances. A guide body 27 is provided having a tapered surface 27a for allowing and a pressing surface 27b for pushing the head 25a of the engraving punch 25 into the hole 5d '' against the second spring 26 when the die 5d is retracted. That is, when the die 5d is moved to the forward position, the head 25a of the marking punch 25 protrudes outward from the die 5d due to the tapered surface 27a, so that the leading end of the stamp 25 is in the concave portion 5d 'of the die 5d. When the die 5d moves backward into the die holder 6d, the head 25a of the stamping punch 25 is pushed into the hole 5d "by the pressing surface 27b against the second spring 26, Its tip And it is adapted to plunge the marking pattern 25b from the hole portion 5d "in the recess 5d 'of the die 5d.
[0015]
In the embodiment shown in the drawings, the die 5d is constituted by two split dies 50d 'and 50d ", but may be constituted by one die.
[0016]
Next, the operation of the above embodiment will be described.
By the plurality of forging stations A to D described above, the material is sequentially forged from coarse to fine by the corresponding dies 5a to 5d and punches 9a to 9d to form, for example, hexagonal nuts. Here, in the final step, as shown in FIG. 2, the intermediate molded product S whose outer periphery is hexagonal and whose central portion has not been penetrated yet is transferred to a position in front of the die 5 d in the final forging station D. Immediately thereafter, the punch 9d is advanced by the ram 4, and the intermediate molded product S is stored in the die 5d.
[0017]
Then, as the ram 4 further advances, the punch 9d presses the intermediate molded product S housed in the die 5d with a large force. As a result, the intermediate molded product S is formed by forging the outer surface and both end surfaces into a shape corresponding to the inner surface shape of the die 5d, and the closed thin portion at the center thereof is punched out by the fixing pin 15 for punching, thereby obtaining a predetermined shape. A hexagonal nut N is formed as a final molded product having a through hole having a diameter.
[0018]
In this case, when the ram 4, that is, the punch 9 d moves forward, the die 5 d retreats into the die holder 6 d via the intermediate molded product S. At this time, the taper surface 27a of the guide body 27 pushes the head 25a of the stamp 25 into the hole 5d "against the second spring 26, and the stamp pattern 25b at the tip of the hole 25d". Through the recess 5d 'of the die 5d. Thereby, the marking pattern 25b of the marking punch 25 is pressed against the outer peripheral surface of the nut N in the die 5b, and the pattern 25b is formed on the surface.
[0019]
Thereafter, when the ram 4 starts retreating, the die 5d is also pushed forward by the first spring 12. Along with this, the head 25a of the marking punch 25 moves radially outward along the tapered surface 27a by the second spring 26, and is pushed out of the die 5d. Thus, the stamping pattern 25b of the stamping punch 25 is released from the recess 5b 'of the die 5d, and subsequently the knockout pin 18 moves forward to advance the stripper 17 via the push rod 21. As a result, the nut N in the die 5d is extruded to the outside, whereby the nut N with the stamp X engraved on the outer surface as shown in FIG. 5 is completed.
[0020]
Therefore, the stamping process can be performed simultaneously with the head forming of the nut N without providing a separate stamping machine. Moreover, by performing the stamping in the molded state, there is no swelling or burrs around the stamping. It is possible to form a smooth in-plane stamp X. In addition, since the engraving mechanism is built in the mold 7d including the die 5d and the die holder 6d, the entire molding machine does not become large.
[0021]
In the above embodiment, the engraving X is engraved on the outer peripheral surface at the same time as the punching of the intermediate molded product S. However, the engraving X having the dummy die 5d and the punch 9d is provided. A forging station may be provided to perform only the processing.
[0022]
As described above, according to the multi-stage press forming machine according to the present invention, engraving of a stamp performed on a side surface of a formed product from a direction orthogonal to the axial direction is performed by forming the formed product in the press forming machine. This can be performed simultaneously or continuously, and the productivity of the molded product to be marked can be significantly improved. Therefore, the stamping can be performed at the same time as the forging of the molded product without providing a separate stamping machine. Moreover, by performing the stamping in the molding state, the stamping can be performed smoothly without any swelling and burrs around the stamping. Can be molded. In addition, the engraving mechanism is devised so that the engraving punch, which can move in and out, is compactly built in the mold including the die and the die holder, so that the entire molding machine does not become large.
[0023]
Further, if a fixing pin for punching is provided at the center of the die, and a stripper for extruding the formed intermediate molded product or the final molded product to the outside is provided between the fixing pin and the die so as to be able to advance and retreat. The stamping process can be performed simultaneously with the punching of the intermediate molded product or the final molded product.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a multi-stage press forming machine according to the present invention.
FIG. 2 is a vertical sectional side view of a main part of the pressure forming machine.
FIG. 3 is a vertical sectional side view showing an operation state of the main part.
FIG. 4 is a view taken in the direction of arrows AA in FIG. 3;
FIG. 5 is a side view of a product formed by the pressure molding machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Multi-stage press forming machine 3 Die block 5a-5d Die 5d 'Material storage recess 5d "Hole 6a-6d Die block 9a-9d Punch 12 First spring 25 Marking punch 26 Second spring 27 Guide body 27a Tapered surface

Claims (2)

In a multi-stage die forging machine in which a plurality of dies arranged side by side on a die block and a plurality of punches which move forward and backward in opposition to the die are used to continuously and continuously forge the material from coarse to fine. A specific die of the plurality of dies is provided in the die holder so as to be able to advance and retreat in the axial direction, and the die is normally urged to the punch side by a first spring. On the side of the die, a stepped hole that opens to the inner surface of the material storage recess is formed, and the tip of the hole is moved from the hole. A second spring for providing a stamping punch with a head facing the inside of the recess so as to be able to advance and retreat in a direction perpendicular to the axial direction of the die, and interposing the stamping punch between the head and the step of the hole; Biased in the retreat direction so that its head is always more radial than the die On the inner peripheral surface of the die holder, allowing the head of the stamping punch to protrude outward from the die when the die moves forward, and holding the head of the stamping punch to the second spring when the die retracts. A multi-stage press-forming machine, characterized in that a guide portion having a tapered surface is provided which presses against the inside of the hole and pushes the tip end thereof into the recess of the die from the hole. A fixing pin for punching is provided at the center of the die, and a stripper for extruding the formed intermediate molded product or the final molded product to the outside is provided between the fixing pin and the die so as to be able to advance and retreat. The multi-stage press forming machine according to claim 1, characterized in that:

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