JP2004122176A - Method and apparatus for backward extrusion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extruding method and an extruding apparatus in which the buckling of a counter punch is hard to occur even when manufacturing extruded products having large dimension ratio L/D. <P>SOLUTION: A counter punch holder 33 for fixing the base part of the counter punch 32 is provided with a plurality of guide holes 33c arranged so as to surround the circumferential surface of the counter punch 32 and penetrated in parallel with the axial direction of the counter punch 32 , and knockout pins 34 are slidably inserted through the guide holes 33c. The knockout pin 34 is extended in parallel with the counter punch 32 and interposed between the circumferential surface of the counter punch 32 and the inner peripheral surface of the die hole 31. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a backward extrusion method and a backward extrusion apparatus for backwardly extruding a workpiece material inserted into a die hole by a counter punch installed inside the die hole to obtain an extruded product having a hole.
[0002]
[Prior art]
Conventionally, the work material inserted into the die hole is compressed by a counter punch installed inside the die hole and a punch entering the die hole, and the counter punch is used to extrude backward, and the extruded product having the hole formed is compressed. The resulting rearward extrusion device was configured, for example, as shown in FIGS. Into a die hole 11 formed in the die 1 and defining the outer diameter of the extruded product P, a counter punch 12 for extruding a workpiece material inserted into the die hole 11 backward to form a hole Pa in the extruded product P. Is erected. The base 12a of the counter punch 12 is fixed to a counter punch holder 13 connected and fixed to the die 1, and the rear end 12b is supported by a die plate 14, so that the processing pressure of the work material can be received. Have been.
[0003]
Between the die hole 11 and the counter punch 12, there is provided a cylindrical knockout sleeve 15 that fits into the inner peripheral surface 11a of the die hole 11 and the outer peripheral surface 12c of the counter punch 12. The knockout sleeve 15 is a counter punch. The guide 12 is slidable. The rear end 15b of the knockout sleeve 15 is supported by a sleeve spacer 16, and the knockout sleeve 17 is inserted into a guide hole 13c formed through the counter punch holder 13 and moves forward and backward with a knockout pin 17 connected to the sleeve spacer 16. As a result, the inside of the die hole 11 can be slid.
[0004]
The operation of the above-mentioned conventional extrusion processing apparatus is as follows. First, after the workpiece material is inserted into the die hole 11, the slide 2 moves in the direction approaching the die 1 side, and the punch 21 fixed to the slide 2 and the counter punch 12 installed inside the die hole 11. Compress work material between By compressing the workpiece material, the material flows between the inner peripheral surface 11a of the die hole 11 and the outer peripheral surface 12c of the counter punch 12, and an extruded product P having a hole Pa is formed (FIG. 7). . Thereafter, the knockout pin 17 advances in the direction of the die hole 11, and the tip 15 c of the knockout sleeve 15 supported by the sleeve spacer 16 projects from the die hole 11, and pushes the extruded product P out of the die hole 11. Discharge (FIG. 8).
[0005]
[Problems to be solved by the invention]
By the way, at the time of backward extrusion, in order to secure a molding space 18 for the extruded product P between the inner peripheral surface 11a of the die hole 11 and the outer peripheral surface 12c of the counter punch 12, the rear end side portion 15a of the knockout sleeve 15 ( It is necessary to retract the portion indicated by the dimension X) from the die hole 11 to the counter punch holder 13 side. Therefore, between the rear end portion 11b of the die hole 11 and the front end portion 13a of the counter punch holder 13, a space for accommodating the rear end portion 15a of the knockout sleeve 15 is required. It had to be long, and the size of die 1 was large.
[0006]
The counter punch 12 has its outer peripheral surface 12c supported by the knockout sleeve 15 so as to be kept in a straight line. However, when the backward extrusion is started, the rear end side of the knockout sleeve 15 as shown in FIG. The portion 15a moves into the die hole 11 and becomes a bare state without support. Further, since the knockout sleeve 15 is set in accordance with the shape of the extruded product P to be extruded backward, it is not possible to obtain a sufficient thickness depending on the shape of the extruded product P, and the strength for keeping the counter punch 12 in a linear state. May not be secured.
[0007]
Therefore, if the counter punch 12 is too elongated, there is a possibility that buckling deformation may occur due to the reaction force when the work material is pushed backward. The only way to suppress the length of the counter punch 12 is to shorten the length of the extruded product P. Therefore, only an extruded product in which the dimension ratio L / D of the axial dimension L and the radial dimension D is suppressed can be manufactured. Had occurred.
[0008]
In view of such circumstances, the present invention provides an extrusion method and an extrusion processing apparatus in which buckling of a counterpunch is less likely to occur even when an extruded product having a large dimensional ratio L / D is manufactured while keeping the length of the counterpunch short. It is something to try to provide.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the work material inserted into the die hole is compressed by the counter punch installed inside the die hole and the punch entering the die hole, and the counter punch is used to perform backward extrusion. A backward extrusion method,
On a counter punch holder for fixing the base of the counter punch, a plurality of guide holes arranged so as to surround the outer peripheral surface of the counter punch are formed so as to penetrate in parallel with the axial direction of the counter punch,
Insert a knockout pin slidably into the guide hole,
Extending the knockout pin parallel to the counter punch and interposing between the outer peripheral surface of the counter punch and the inner peripheral surface of the die hole,
When inserting the work material into the die hole and allowing the punch to enter, the knockout pin is used to secure a molding space for an extruded product between the inner peripheral surface of the die hole and the outer peripheral surface of the counter punch. Retreat to the counter punch holder side,
After the backward extrusion is completed and the punch is withdrawn from the die hole, the knockout pin is advanced so that the tip of the knockout pin projects from the die hole and the extruded product is discharged from the die hole. A backward extrusion method is provided.
[0010]
According to the invention of claim 2, the work material inserted into the die hole is compressed by a counter punch installed inside the die hole and a punch entering the die hole, and the counter punch is used to perform backward extrusion. A rear extrusion device,
A plurality of guide holes arranged so as to surround an outer peripheral surface of the counter punch are formed in a counter punch holder for fixing a base portion of the counter punch in parallel with an axial direction of the counter punch,
A knockout pin is slidably inserted into the guide hole,
The knockout pin extends parallel to the counter punch and is interposed between an outer peripheral surface of the counter punch and an inner peripheral surface of the die hole,
When allowing the punch to enter the die hole into which the work material has been inserted, the knockout pin is used to secure a molding space for an extruded product between the inner peripheral surface of the die hole and the outer peripheral surface of the counter punch. Retreat to the counter punch holder side,
After the backward extrusion is completed and the punch is withdrawn from the die hole, the knockout pin is advanced so that the tip of the knockout pin projects from the die hole and the extruded product is discharged from the die hole. A rear extrusion device is provided.
[0011]
According to the first and second aspects of the present invention, it is necessary to lengthen the counter punch in order to secure a molding space for extruded products, that is, to secure a space for accommodating the knockout sleeve, as in the conventional rear extrusion device. There is no. In addition, the portion of the knockout pin other than the portion in contact with the extruded product is held linearly by the knockout pin supported by the inner peripheral surface of the die hole and the guide hole, so that it easily buckles even when a large processing pressure is applied. Never. Therefore, even when an extruded product having a large dimensional ratio L / D is manufactured, the buckling of the counter punch is less likely to occur.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 to FIG. 6 are views for explaining the rearward extruder of the present embodiment. The rear extrusion apparatus is for extruding a workpiece material inserted in a die hole backward by a counter punch installed in the die hole to obtain an extruded product having a hole formed therein. The rear extrusion apparatus includes a die 3 having a die hole 31 into which a work material W is inserted and a counter punch 32 installed inside the die hole 31, and a punch 41 which enters the die hole 31 and compresses the work material W. Is configured in combination with the slide 4 to which is attached.
[0014]
The die hole 31 receives the cylindrical workpiece material W to be subjected to the backward extrusion, and defines the outer diameter of the extruded product P obtained by the backward extrusion with the inner peripheral surface 31a. Inside the die hole 31, a counter punch 32 for axially compressing the work material W inserted into the die hole 31 in cooperation with the punch 41 and extruding the work material W backward is coaxial with the die hole 31. It is installed as follows. The base 32a of the counter punch 32 is fixed to a counter punch holder 33 that is connected and fixed to the rear end side of the die hole 31 in the die 3. The counter punch 32 and the counter punch holder 33 have rear ends 32b and 33b supported by a die plate 5 connected and fixed to the die 3, and can receive a processing pressure generated when the work material W is compressed.
[0015]
As shown in FIG. 6, the counter punch holder 33 has three (plural) guide holes 33c arranged so as to surround the outer peripheral surface 32c of the counter punch 32 at intervals in the circumferential direction. The counter punch 32 is formed so as to penetrate in parallel with the axial direction of the counter punch 32 so as to contact the outer peripheral surface 32 c of the counter punch 32. Although the root 32a of the counter punch 32 has a larger diameter than the other portion (outer peripheral surface 32c) of the counter punch 32, the portion protruding into the guide hole 33c due to the formation of the groove 32d. Has been removed. An operation pin hole 51 having the same cross section as the guide hole 33c is formed in the die plate 5 so as to be connected to the guide hole 33c.
[0016]
A knockout pin 34 is slidably inserted through the guide hole 33c. The knockout pin 34 extends in parallel with the counter punch 32, and is interposed between the outer peripheral surface 32c of the counter punch 32 and the inner peripheral surface 31a of the die hole 31 to support the counter punch 32 from the periphery. I have. An operation pin 52 for supporting the rear end portion 34b of the knockout pin 34 is inserted into the operation pin hole 51, and operates to move the knockout pin 34 back and forth at the following timing.
[0017]
When the workpiece material W is inserted into the die hole 31 and backward punching is performed by the entry of the punch 41 (FIG. 3), the knockout pin 34 retreats toward the counter punch holder 33 and the inner peripheral surface of the die hole 31. A molding space 35 for extruded products is secured between 31a and the outer peripheral surface 32c of the counter punch 32. After the rearward extrusion is completed and the punch 41 withdraws from the die hole 31 (FIG. 5), the knockout pin 34 moves forward, and the extruded product P is discharged by causing the tip 34 a to protrude from the die hole 31.
[0018]
The punch 41 attached to the slide 4 is arranged so as to be coaxial with the die hole 31, the root 41a is fixed by a punch case 42, the rear end 41b is supported by a punch spacer 43, and the workpiece material W It is possible to receive the processing pressure generated when compressing the. The punch 41 pushes the work material W backward like the counter punch 32, and a punch sleeve 44 is fitted between the punch 41 and the die hole 31. A rear end portion 44a of the punch sleeve 44 is supported by a sleeve set plate 45, and a knockout guide pin 46 is supported on the sleeve set plate 45 so as to be slidable with respect to the punch case 42. The knockout guide pin 46 is configured to be slid back and forth by an operation rod 48 via a knockout plate 47.
[0019]
The operation of the above embodiment will be described. First, in a state where the slide 4 is separated from the die 3, the work material W is set at a position where it can be inserted into the die hole 31 by a manipulator (not shown) (FIG. 1). After the manipulator inserts a part of the workpiece material W into the die hole 31, the slide 4 approaches the die 3 and is completely pushed into the die hole 31 by the punch 41 (FIG. 2). In addition, concave portions Wa and Wb are formed at both ends of the work material W, so that the work material W and the counter punch 32 and the punch 41 can be reliably centered.
[0020]
When the slide 4 further approaches the die 3, the punch 41 enters the die hole 31, and the work material W is compressed by the counter punch 32 and the punch 41 and extruded backward, thereby forming an extruded product P (FIG. 3). At this time, the knockout pin 34 retreats to the counter punch holder 33 side in conjunction with the movement of the slide 4, and the extruded product molding space 35 is formed between the inner peripheral surface 31 a of the die hole 31 and the outer peripheral surface 32 c of the counter punch 32. Secure. Further, as the slide 4 advances, the operation rod 48 retreats relatively to the slide 4, and the punch sleeve 44 secures the molding space 35 by the material of the work material W flowing between the punch 41 and the die hole 31. To be retreated.
[0021]
When the slide 4 starts to retreat, the punch rod 44 is advanced relatively to the punch 41 by the operating rod 48, and the extruded product P is separated from the punch 41 (FIG. 4). When the slide 4 further retreats, the punch 41 and the punch sleeve 44 retreat from the die hole 31. The knockout pin 34 advances in conjunction with the movement of the slide 4, and pushes the extruded product P out of the die hole 31 (FIG. 5).
[0022]
As described above, the knockout pin 34 is extended to the inside of the die hole 31, and the extruded product P is directly extruded and discharged to the outside by the knockout pin 34, so that the cylinder used in the conventional rear extrusion device is used. Shaped knockout sleeves can be eliminated. Accordingly, it is not necessary to lengthen the counter punch in order to secure the accommodation space for the knockout sleeve, and it is possible to eliminate the cause of buckling deformation.
[0023]
Further, the knockout pin 34 is interposed so as to surround the outer peripheral surface 32c of the counter punch 32 and to be sandwiched between the outer peripheral surface 32c of the counter punch 32 and the inner peripheral surface 31a of the die hole 31. The part other than the part 32 in contact with the extruded product P is held linearly by the high-strength die hole 31, and does not easily buckle even when a large processing pressure is applied.
[0024]
In the present embodiment, the punch 41 is also extruded backward so as to form an extruded product P having holes formed at both ends. However, the present invention is not limited to this, and the punch 41 is fitted into the die hole 31. The size may be such that the work material W is only pressed against the counter punch 32.
[0025]
In the present embodiment, the punch 41 is moved forward and backward with respect to the die hole 31. However, the die hole 31 may be moved forward and backward with respect to the punch 41.
[0026]
In the present embodiment, the knockout pin 32 is retracted in conjunction with the movement of the slide 4. However, the present invention is not limited to this. The knockout pin 32 is set in a free state, and the work flowing between the counter punch 32 and the die hole 31 is moved. You may make it retreat by being pushed by the material of the raw material.
[0027]
The backward extrusion method and the backward extrusion device of the present invention are not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the scope of the present invention.
[0028]
【The invention's effect】
As described above, according to the present invention, as in the case of the conventional rear extruder, the counter punch is purposely lengthened in order to secure the molding space for the extruded product, that is, to secure the accommodation space for the knockout sleeve. No need. In addition, the portion of the knockout pin other than the portion in contact with the extruded product is held linearly by the knockout pin supported by the inner peripheral surface of the die hole and the guide hole, so that it easily buckles even when a large processing pressure is applied. Never. Therefore, the die can be reduced in size, and an excellent effect that buckling of the counter punch hardly occurs even when an extruded product having a large dimensional ratio L / D is manufactured can be obtained.
[Brief description of the drawings]
FIG. 1 is a view showing a state in which a workpiece material is set in a rearward extruder according to an embodiment of the present invention.
FIG. 2 is a diagram showing a state in which a workpiece material is pushed into a die hole of the rearward extruder according to the embodiment of the present invention.
FIG. 3 is a diagram showing a state in which backward extrusion is completed by the backward extrusion device according to the embodiment of the present invention.
FIG. 4 is a diagram showing a state in which a punch is separated from an extruded product that is rearward extruded by the rearward extruder according to the embodiment of the present invention.
FIG. 5 is a diagram showing a state in which an extruded product is discharged to the outside from a die hole of the rear extruder according to the embodiment of the present invention.
FIG. 6 is a sectional view taken along the line AA in FIG. 1;
FIG. 7 is a view showing a state in which backward extrusion by a conventional backward extrusion device is completed.
FIG. 8 is a view showing a state in which an extruded product is discharged from a conventional backward extruder.
FIG. 9 is a sectional view taken along line BB in FIG. 7;
[Explanation of symbols]
3 die 4 slide 31 die hole 31a inner peripheral surface 32 counter punch 32c outer peripheral surface 33c guide hole 33 counter punch holder 34 knockout pin 41 punch P extruded product W work material

Claims (2)

A backward extrusion method in which the workpiece material inserted into the die hole is compressed by a counter punch installed in the die hole and a punch entering the die hole, and the counter punch performs backward extrusion.
On a counter punch holder for fixing the base of the counter punch, a plurality of guide holes arranged so as to surround the outer periphery of the counter punch are formed so as to penetrate in parallel with the axial direction of the counter punch,
Insert a knockout pin slidably into the guide hole,
Extending the knockout pin parallel to the counter punch and interposing between the outer peripheral surface of the counter punch and the inner peripheral surface of the die hole,
When inserting the work material into the die hole and allowing the punch to enter, the knockout pin is used to secure a molding space for an extruded product between the inner peripheral surface of the die hole and the outer peripheral surface of the counter punch. Retreat to the counter punch holder side,
After the backward extrusion is completed and the punch is withdrawn from the die hole, the knockout pin is advanced so that the tip of the knockout pin projects from the die hole and the extruded product is discharged from the die hole. Back extrusion method characterized by the above-mentioned. A work material inserted into the die hole, compressed by a counter punch installed inside the die hole and a punch that enters the die hole, a rear extrusion device that performs rear extrusion by the counter punch,
A plurality of guide holes arranged so as to surround an outer peripheral surface of the counter punch are formed in a counter punch holder for fixing a base portion of the counter punch in parallel with an axial direction of the counter punch,
A knockout pin is slidably inserted into the guide hole,
The knockout pin extends parallel to the counter punch and is interposed between an outer peripheral surface of the counter punch and an inner peripheral surface of the die hole,
When allowing the punch to enter the die hole into which the work material has been inserted, the knockout pin is used to secure a molding space for an extruded product between the inner peripheral surface of the die hole and the outer peripheral surface of the counter punch. Retreat to the counter punch holder side,
After the backward extrusion is completed and the punch is withdrawn from the die hole, the knockout pin is advanced so that the tip of the knockout pin projects from the die hole and the extruded product is discharged from the die hole. A rearward extrusion device characterized by the above-mentioned.

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