JP3132274U - Punch holding mechanism of forging machine - Google Patents

Abstract

An object of the present invention is to improve the holding force of a punch by a collet chuck so that a punch can be easily and quickly replaced without taking out a die holder from a punch case.
A punch holding mechanism 11 is inserted into an outer periphery of a rear end portion of a punch 6, and a plurality of dividing grooves having front and rear tapered portions 12c and 12d and capable of elastically reducing the diameter are formed in a bowl shape. The collet chuck 12, the punch holder 13 having the collet chuck 12 holding hole 13 a and the outer peripheral threaded portion 13 b, and the rear tapered portion 12 d of the collet chuck 12 and the holding hole 13 a of the punch holder 13 are interposed. The chuck spacer 14 with the taper inner surface 14a, the pressure receiving member 15 fitted to the rear side of the punch holder 13 to receive the punch, and the inner screw screwed into the taper inner surface 16a and the screw portion 13b along the front taper portion 12c. And a fastening body 16 that pushes the collet chuck 12 rearward.
[Selection] Figure 2

Description

  The present invention relates to a punch holding mechanism of a forging machine that forms a molded product having a predetermined shape by forging a material with a die and a punch that moves forward and backward.

Technical background

  Conventionally, as this kind of punch holding mechanism, for example, as shown in FIGS. 11 to 13, a punch 21 and a frustoconical collet formed with a plurality of radially dividing grooves 22a. A chuck 22, a punch holder 24 that is detachably fixed to a punch case fixed to a ram (not shown) through appropriate fixing means, and a holding hole 24 b having a tapered inner surface 24 a on the tip side of the punch holder 24. It consists of a fastening screw 26 provided with a carbide tip 25 and a head portion 26a which are screwed into the rear portion and press the collet chuck 22 toward the tip side.

  When the punch 21 is attached to the punch holder 24, the collet chuck 22 is pressed against the tip-side tapered inner surface 24 a of the punch holder 24 by tightening the tightening screw 26, and the diameter of the collet chuck 22 is reduced to fix the punch 21. When the punch 24 is removed from the punch holder 24 and replaced, the collet chuck 22 is expanded by loosening the tightening screw 26 after removing the punch holder 24 from the punch case 23. Thus, the punch 21 can be pulled out from the collet chuck 22 and taken out.

  However, in the conventional punch holding mechanism described above, the collet chuck 22 has a frustoconical shape and has a one-side taper shape, so that the holding force of the punch 21 by the collet chuck 22 is limited, and is used several times. As a result, the entire shaft portion of the punch 21 cannot be held evenly, so that there is a problem that play or looseness easily occurs and uneven wear occurs. As a result, there is a problem that the shaft center of the punch 21 with respect to the die is displaced in a short period of time, and the tip end portion of the punch 21 is subjected to an uneven load, causing deformation, chipping, cracking, or the like. It was.

  Therefore, the present invention is intended to solve the problems of such a conventional configuration, effectively improving the holding force of the punch by the collet chuck, deformation of the punch, chipping, cracks, It is an object of the present invention to provide a punch holding mechanism of a forging machine that can prevent breakage and the like over a long period of time and can easily and quickly replace the punch without removing the die holder from the punch case on the ram side.

  In order to solve the above problem, the invention described in claim 1 of the present invention is a forging method in which a material is forged by a die and a punch that moves forward and backward to face the die to form a molded product having a predetermined shape. In the punch holding mechanism of a molding machine, the punch holding mechanism is inserted into the outer periphery of the punch and the rear end portion of the punch, has a circumferential groove in the middle portion, and inclines in a tapered manner from both ends of the circumferential groove to the front and rear. A collet chuck having a plurality of radial dividing grooves formed in a bowl shape so as to have a front and rear taper portion and elastically shrinkable, and a detachable ram side, and a collet chuck holding hole at the tip A punch holder having an outer peripheral thread portion, a chuck spacer with a tapered inner surface interposed between a rear taper portion of the collet chuck and the holding hole of the punch holder, and a rear portion side of the punch holder holding hole. Combined A pressure receiving member for receiving the rear end of the punch, a taper inner surface along the front taper portion of the collet chuck, and an inner screw portion screwed into the screw portion of the punch holder, and a tightening body for pushing the collet chuck backward. The collet chuck is pushed in backward by tightening the tightening body, and the collet chuck is compressed at both the front and rear taper parts to fasten and fix the punch, while the collet chuck is expanded by loosening the tightening body against the punch holder. It is characterized in that it has a diameter, and the punch can be pulled forward from the collet chuck.

  Further, the invention described in claim 2 of the present invention is provided with a through hole that opens to the outside at a position facing the rear end of the chuck spacer in the punch holder, in addition to the configuration described in claim 1. A gap communicating with the through hole is provided between the chuck spacer and the pressure receiving member, and a plurality of communication grooves for cooling liquid extending in the axial direction are formed on the inner peripheral surface of the collet chuck and extending in the axial direction. A feature is that the coolant is linearly sprayed from the punch holder side to the punch tip side through the gap between the pressure receiving member and the chuck spacer and the communication groove on the inner surface of the collet chuck.

  According to the present invention, with the above-described configuration, when the punch is attached to the punch holder, the collet chuck is pushed rearward by tightening the fastening body, and the collet chuck is compressed at both the front and rear taper portions to thereby compress the shaft portion of the punch. The punch can be securely tightened and fixed while the whole is held evenly. As a result, the holding force of the punch by the collet chuck can be remarkably improved, and the occurrence of backlash and uneven wear of the collect chuck due to long-term use can be effectively suppressed. As a result, the punch tip is deformed by an uneven load. , Chipping, cracks, etc., or punch breakage can be prevented over a long period of time. In addition, the collet chuck can be expanded in diameter by loosening the clamping body with respect to the punch holder, and the fixing of the punch can be released. At the same time, the punch can be pulled forward from the collet chuck and replaced with a new punch easily and quickly. .

  In addition, a clearance is provided between the pressure receiving member in the punch holder and the rear end portion of the chuck spacer, and a communication groove for coolant that communicates with the clearance and extends in the axial direction on the inner peripheral surface of the collet chuck. By forming a plurality of the collet chucks from the punch holder side, the cooling liquid is linearly sprayed to the punch tip side through the gap between the pressure receiving member and the chuck spacer and the communication groove on the inner surface of the collet chuck. Coolant sprayed linearly from the internal communication groove is accurately applied to the most important molding part in molding, so that the punch and molded product can be reliably prevented from being burned, and the punch life can be greatly extended. it can. In addition, collet chucks, pressure-receiving members, chuck spacers, etc. located around the punch that heats up during forging can be cooled effectively, and punch deformation and cracks caused by temperature rise or punch breakage Etc. can be effectively prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of a forging molding machine according to the present invention. The molding machine 1 is a die block 3 fixed at a predetermined position of a machine base 2, and moves forward and backward toward the die block 3. And a ram 4. On the front surface of the die block 3, a plurality of dies 5...

  On the other hand, on the front surface of the ram 4, punches 6... 6 are fixedly arranged in parallel through punch cases 7... 7 so as to face the dies 5. ... 6 and dies 5 ... 5 constitute a plurality of forging stations.

  Further, on one side of the die block 3, a front side quill 8 of the machine base 2 and a material supply roll 9 for supplying a rod-shaped wire A introduced from the rear part of the machine base 2 are provided. A cutter 10 is mounted on the front surface of the quill 8, and the cutter 10 is reciprocally driven with a predetermined stroke in a direction in which the dies are juxtaposed through an appropriate drive mechanism (not shown). 8, the wire A fed forward is cut into a predetermined size. And the blank B cut | disconnected by the cutter 10 by the predetermined dimension is forge-processed in steps gradually in each forging station by a raw material transfer apparatus (not shown), and the product made into the predetermined shape is formed in the forging station of the last stage. It has come to be.

  In the present invention, as shown in FIGS. 2 to 4, in order to fix and hold any or all of the punches 6... 6 on the punch case 7 on the ram 4 side, the punch holding mechanism 11 is as follows. It was configured as follows.

  The punch holding mechanism 11 includes a punch 6, a collet chuck 12 that is fitted on the outer periphery of the rear end portion of the punch 6, a punch holder 13, a chuck spacer 14, and a pressure receiving force that is interposed at the center of the punch holder 13. The member 15 is constituted by a fastening body 16 that is screwed to the tip end portion of the punch holder and that compresses the collet chuck 12 by pushing it backward.

  The punch 6 is a hexagonal bolt bolt punch and has a cylindrical pin shape. As shown in FIGS. 5 to 8, the collet chuck 12 has a through hole 12a that can be fitted to the outer periphery of the rear end portion of the punch 6, and has a circumferential groove 12b in the middle portion in the longitudinal direction. There are front and rear taper portions 12c and 12d that are tapered in front and rear from both ends, and radial dividing grooves 12e... 12e, 12f. Eight are formed in a shape. The punch holder 13 has a cylindrical shape and is detachably attached to the ram 4 side by appropriate attaching means (not shown) such as a fixing bolt, while a tip end portion includes a collet chuck holding hole 13a and an outer peripheral screw portion 13b. A fitting hole 13d of a pressure receiving member, which will be described later, is formed at the rear end portion via a step portion 13c. The chuck spacer 14 is cylindrical and has a tapered inner surface (through hole) 14a along the rear tapered portion 12d of the collet chuck 12. Between the holding hole 13a of the punch holder 13 and the rear tapered portion 12d of the collet chuck 12. Is intervened. The pressure receiving member 15 is fitted to the rear side of the fitting hole 13 d of the punch holder 13 and receives the rear end of the punch 6. The fastening body 16 has a taper inner surface 16a along the front taper portion 12c of the collet chuck 12 and an inner screw portion 16b screwed to the outer peripheral screw portion 13b of the punch holder 13, and the collet chuck 12 is moved rearward by tightening. It is configured to push in. Further, a locking portion 16c. Of a jig (not shown) for rotating the fastening body 16 is provided on the outer peripheral portion of the fastening body 16. 16c is formed. In FIG. 2, reference numeral 17 denotes a support member built in the back of the punch case 7.

  The collet chuck 12 is pushed backward by tightening the tightening body 16 to compress the collet chuck 12 at both the front and rear taper portions 12c and 12d to fasten and fix the punch 6, while the tightening body 16 is fixed to the punch holder 13. However, the diameter of the collet chuck 12 is increased by loosening the punch 6 so that the punch 6 can be pulled forward from the collet chuck 12.

  Next, the operation of the forging machine 1 provided with the punch holding mechanism 11 configured as described above will be described.

  When the new punch 6 is attached to the punch holding mechanism 11, first, the fastening body 16 is loosened and retracted from the punch holder 13, and the collet chuck 12 is expanded by its elastic restoring force. Then, with the collet chuck 12 in an expanded state, the punch 6 to be replaced is pulled out from the collet chuck 12, and then a new punch 6 strikes the pressure receiving spacer 16 at the back of the collet chuck 12 from the front end opening. Plug in. Next, the tightening body 16 is screwed into the punch holder 13 and tightened. By tightening the tightening body 16, the front tapered portion 12 c of the collet chuck 12 is pushed backward by the tapered inner surface 16 a of the tightening body 16. As a result, the collet chuck 12 is reduced in diameter at both the front and rear taper portions 12c and 12d by the taper inner surface 16a of the tightening body 16 and the chuck space 14 taper inner surface 16a, and the entire shaft portion of the punch 6 is evenly distributed by the collet chuck 12. Can be securely tightened and fixed. Therefore, the holding force of the punch 6 by the collet chuck 12 can be remarkably improved, and at the same time, the holding force can be maintained over a long period of time to prevent the punch 6 from rattling or uneven wear. As a result, it is possible to prevent over a long period of time that an uneven load is applied to the tip of the punch 6 to cause deformation, chipping or cracking at the tip, or the punch 6 is broken.

  9 and 10 show another embodiment in which the punch holding structure 11 of the above-described embodiment is provided with a communication path for punch cooling by a coolant such as oil coolant. A through hole 13e that opens to the outside is provided at a position facing the rear end of the spacer 14 for use, and a clearance S that communicates with the through hole 13e is provided between the chuck spacer 14 and the pressure receiving member 15, and a collet chuck A plurality of coolant communication grooves 12g... 12g extending in the axial direction are formed on the inner peripheral surface of the coolant 12 and the coolant is supplied to the pressure holder 15 and the chuck spacer 14 from the punch holder 13 side. Are formed so as to be linearly sprayed to the front end side of the punch via the gap S between them and the communication grooves 12g... 12g on the inner surface of the collet chuck 12. In this case, the punch case 7 is provided with a communication hole 7a communicating with the through hole 13e of the punch holder 13, and a cooling liquid injection pump is connected to the communication hole 7a through a connection pipe, though not shown.

  If comprised in this way, the cooling fluid injected linearly from the communicating grooves 12g ... 12g on the inner surface of the collet chuck 12 is accurately applied to the most important molding part in molding, and the punch 6 and the molded product are baked. Can be reliably prevented, and the life of the punch 6 can be greatly extended. In addition, the collet chuck 12, the pressure receiving member 15, the chuck spacer 14 and the like that are heated together with the punch 6 at the time of forging can be effectively cooled. 6 breakage and the like can be effectively prevented.

  In particular, the coolant sprayed to the outside from the communication grooves 12g... 12g of the collet chuck 12 is sprayed to the outside along the outer periphery of the punch 6 from the communication grooves 12g. There is no. Accordingly, the cooling liquid not only has the effect of cooling the tool such as the punch 6 but also has a real purpose of forming a hexagonal hole forming punch (a punch used when forming a hexagonal bolt) 6 as a molding material. When the square hole is formed, the punch 6 and the molded product are prevented from being burned and the wear is reduced. That is, the life of the punch 6 can be greatly extended by accurately applying the coolant injected linearly from the communication grooves 12g.

  The radial dividing grooves 12e... 12e, 12f... 12f of the collet chuck 12 are not limited to eight provided in a bowl shape. For example, four or ten are appropriately provided depending on the size. May be.

  It is a schematic plan view of the forging machine provided with the punch holding mechanism according to the present invention.   It is a longitudinal cross-sectional view of a punch holding mechanism.   It is a front view of the principal part.   It is AA sectional drawing of FIG.   It is a side view of a collet chuck.   It is a front view of a collet chuck.   It is the BB sectional view taken on the line of FIG.   It is CC sectional view taken on the line of FIG.   It is explanatory drawing of another embodiment.   It is a front view of the principal part.   It is explanatory drawing of a prior art example.   It is a side view of the collet chuck.   It is a front view of the collet chuck.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Forging machine 5 Die 6 Punch 11 Punch holding mechanism 12 Collet chuck 12b Circumferential groove 12c Front taper part 12d Rear taper part 12g Communication groove 13 Punch holder 13a Holding hole 13e Through hole 14 Spacer for chuck 14a Taper inner surface 15 Pressure receiving member 16 Tightening body 16a Tapered inner surface 16b Inner threaded portion S Clearance

Claims (2)

  In a punch holding mechanism of a forging machine that forms a molded product of a predetermined shape by forging a material with a die and a punch that moves forward and backward, the punch holding mechanism includes a punch and a rear end portion of the punch. A radially dividing groove that is inserted into the outer periphery, has a circumferential groove in the middle part, and has a front and rear taper part that inclines forward and backward from both ends of the circumferential groove, and can be elastically reduced in diameter. A collet chuck formed in a plurality of bowl shapes, a punch holder that is detachable on the ram side and has a holding hole for the collet chuck and an outer peripheral threaded portion at the tip, a rear taper portion of the collet chuck, and a punch holder A spacer for a chuck with a tapered inner surface interposed between the holding hole, a pressure receiving member that is fitted to the rear side of the holding hole of the punch holder and receives the rear end of the punch, and a front taper of the collet chuck. And a tightening body that pushes the collet chuck backward, and the collet chuck is pushed backward by tightening the tightening body. The collet chuck was compressed at both the front and rear taper parts, and the punch was tightened and fixed. On the other hand, the collet chuck was expanded by loosening the clamping body against the punch holder, and the punch could be pulled forward from the collet chuck. A punch holding mechanism of a forging machine characterized by the above.   The punch holder has a through hole that opens to the outside at a position facing the rear end of the chuck spacer, and a gap that communicates with the through hole between the chuck spacer and the pressure receiving member. A plurality of communication grooves for cooling liquid that communicate with the clearance on the peripheral surface and extend in the axial direction are formed, and the clearance between the pressure receiving member and the chuck spacer and the communication groove on the inner surface of the collet chuck from the punch holder side. The punch holding mechanism of the forging machine according to claim 1, wherein the punch holding mechanism is configured to linearly inject onto the tip end side of the punch.

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