JP2002079343A - Die unit of heading machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily press-fit a die into a die case in a die unit of a heading machine. SOLUTION: Dies 22 and 23 and spacers 24 and 25 are inserted in the cylindrical die case 21 from a rear end, and a cover member 26 is screwed into a female screw 21d provided on an inner circumferential surface of the rear end of the case 21 to assemble the die unit 14. The dies 22 and 23 are press-fitted into a tapered surface 21a of an inner circumference of a forward end of the die case via the spacers 24 and 25 by tightening a plurality of press-fitting bolts 27...27 from a rear side of the cover member 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a die unit in a press forming machine for forming a material into a predetermined shape by using a pair of dies and punches, and belongs to the field of metal working technology.

[0002]

2. Description of the Related Art A pair of a die and a punch are arranged to face each other, and a material supplied between the die and the punch is driven into the die by the punch to form the material into a product having a predetermined shape. Although the forging machine is widely used, in such a forging machine, it is necessary to change the die according to the shape of the product to be molded. Therefore, for example, Japanese Patent Publication No. 56-37883 discloses this. As described above, a structure is adopted in which the die is housed in a die case to form a unit, and this unit is removably fitted into a mounting hole provided in the molding machine body.

[0003] In this case, as described in the above publication, the conventional die unit has a die case 1 formed in a cylindrical shape as shown in FIG. A tapered surface 1a whose diameter becomes smaller toward the side, and a female screw 1b is provided on the inner peripheral surface of the rear end portion, and the outer peripheral surface of the die 2 is also formed as a tapered surface. With the spacer 3 fitted in
The cover member 4 is screwed into the female thread 1b at the rear end of the die case 1, and the die 2 is pressed into the tapered surface 1a at the front end of the die case via the spacer 3 by tightening the cover member 4. Was sometimes configured to do so.

[0004]

However, in the case of a die unit using a tapered surface as described above, if the pressing force due to the tightening of the cover member 4 from the rear is insufficient, the die 2 can be moved to the front end of the die case. Rattling in the tapered surface 1a of the portion, the dimensional accuracy of the product is reduced, and improper interference between the die 2 and a punch (not shown) occurs, leading to early wear and damage of the die and the punch. It will be.

[0005] Therefore, the die 2 is moved by the die case 1 with a large force.
In order to press-fit into the tapered surface 1a, the cover member 4 is tightened with a large torque to the female screw 1b at the rear end portion of the die case. In order to tighten the cover member 4, a powerful torque wrench with a long arm is required, and as a result, the assembling work of the die unit has been a large-scale and difficult work requiring a large work place and a large amount of labor.

SUMMARY OF THE INVENTION The present invention addresses the above-described problems in a heading machine and has a main object of facilitating an assembling operation of a die unit. And to prevent a decrease in durability due to fatigue of the die and the die case.

[0007]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized in that it is configured as follows.

That is, the invention according to claim 1 of the present application (hereinafter referred to as the invention)
The present invention relates to a die unit attached to a main body of a head forming machine, wherein a front end inner peripheral surface is a tapered surface having a diameter decreasing toward a front end side, and a female screw is formed on a rear end inner peripheral surface. The cylindrical die case fitted into the circular mounting hole provided in the main body, and the outer peripheral surface is a tapered surface whose diameter becomes smaller toward the distal end side, from the rear to the tapered surface of the die case front end portion A die to be fitted, a spacer fitted into the die case so as to be located behind the die, and a cover member screwed to a female screw at a rear end of the die case; The member is provided with a plurality of press-fit bolts around the center axis of the die unit, which press-fit the die into the tapered surface of the die case front end via the spacer by tightening from the rear side of the member. And said that you are.

The invention according to claim 2 (hereinafter referred to as second invention)
In the die unit according to the first aspect of the present invention, the outer diameter of the front end portion of the die case does not become larger than the inner diameter of the mounting hole of the main body even after expansion due to press-fitting of the die into the tapered surface. The diameter is smaller than the outer diameter of a portion behind the front end by a predetermined amount.

According to a third aspect of the present invention, in the die unit of the first aspect, when the front end of the die case is fitted in the mounting hole of the main body, Set to protrude more than a predetermined amount,
A ring member for suppressing expansion of the front end of the die case is fitted to the outside of the protrusion.

With the above configuration, each invention of the present application operates as follows.

First, according to any of the first to third inventions,
After inserting the die and the spacer from the rear end of the cylindrical die case, screwing the cover member into the female screw on the inner periphery of the rear end of the case, and tightening a plurality of press-fit bolts from the rear side of the cover member. The tips of these bolts push the die into the tapered surface of the inner periphery of the front end of the die case via the spacer. In this case, since a plurality of press-fit bolts are provided around the center axis of the die,
By simply tightening the individual bolts with a normal force using a normal tool, the die as a whole is pressed into the tapered surface at the front end of the die case with a large force.

Since the front end of the die case expands in accordance with the amount of press-fit of the die into the tapered surface, the outer diameter of the front end is measured in advance, and the value is compared with the value after press-fitting the die. By measuring the expansion amount by comparing the above, the press-fit state of the die can be grasped. Therefore, it is possible to press-fit the die into an appropriate state by tightening the press-fit bolt while measuring the amount of expansion.

According to the second aspect of the present invention, since the outer diameter of the front end of the die case is smaller than the rear part by a predetermined amount, the front end of the case expands due to the press-fitting of the die as described above. Can be fitted into the mounting hole of the main body. Therefore, it is not necessary to delete the expanded portion to fit into the mounting hole, whereby the amount of expansion can be measured as necessary even after press-fitting the die, and the die of the die corresponding to the amount of expansion can be measured. It is possible to grasp the press-fit state, particularly the magnitude of the shrink force for holding the die from the surroundings.

[0015] Further, since the outer diameter of the front end of the die case is reduced, a gap is secured between the outer peripheral surface of the front end of the die case and the mounting hole of the main body. Even when the die and the front end of the die case expand due to the forging heat, the front end of the die case does not seize in the mounting hole.

Further, according to the third aspect of the present invention, the ring member is fitted to a portion of the front end of the die case that protrudes from the front surface of the main body. In addition, the impact expansion of the die and the die case is suppressed, and the fatigue of the die and the die case due to the repetition of the expansion at the time of driving the material is reduced.

[0017]

Embodiments of the present invention will be described below.

FIG. 1 is a schematic view of a multi-stage press forming machine using a die unit according to the present embodiment. The press forming machine 10 includes one side of a press working space provided in a main body 11. And a ram 13 is disposed on the other side so as to be able to advance and retreat in opposition to the die block 12, and die units 14... 14 and punch units 15. Are attached three by three, and each opposed die unit 14
And three punching stations S with the punch unit 15
1, S2 and S3 are configured.

At one end of the die block 12, a cutter device 16 for cutting a wire a supplied from the outside into a predetermined size is provided, and a material b obtained by cutting the wire a by the cutter device 16 is provided. , And are sequentially supplied to the forging stations S1 to S3 by a material transfer device (not shown). Then, at each of the forging stations S1 to S3, as the ram 13 advances, the respective materials are driven into the dies constituting the die units 14... 14 by the punches constituting the punch units 15. The product is discharged from the station S3.

Next, the structure of the die unit 14 of the die unit 14 to which the present invention is applied, for example, the die unit 14 of the second forging station S2 will be described.

As shown in FIG. 2, this die unit 14
Has a structure in which a first die 22, a second die 23, a first spacer 24, and a second spacer 25 are accommodated in a cylindrical die case 21 from the front end side, and a cover 26 is attached to a rear end. Have been.

The inner peripheral surface of the front end of the die case 21 is a tapered surface 21a whose diameter decreases toward the distal end, and the outer peripheral surfaces of the first and second dies 22, 23 also correspond to the tapered surface 21a. The first and second dies 22, 23 are fitted in the tapered surface 21a of the die case 21 adjacent to the front and rear sides.
Here, the first die 22 has a cavity 22b having a predetermined shape.
The second die 23 is provided with a through-hole 23 b of the knockout pin 31. The outer peripheral surface 21b at the front end of the die case 21 is smaller in diameter by a predetermined dimension x (radius) than the outer diameter (reference outer diameter) of the middle or rear part.

A portion of the die case 21 following the tapered surface 21a is a cylindrical surface 21c having a larger diameter than the tapered surface 21a, and the first and second spacers 24, 25 are formed in the cylindrical surface 21c. Are fitted adjacent to each other in the front-rear direction, and the front end face of the first spacer 24 is in contact with the rear end face of the second die 23. Here, the through holes 24 of the knockout pin 31 are also provided in the first and second spacers 24 and 25.
a, 25a are provided.

Further, the cylindrical surface 21 of the die case 21
c, a female screw 21d is provided on the inner peripheral surface of the rear end portion, and the female screw 21d is provided with a male screw 26a at the front of the cover 26.
Is screwed. The cover 26 has a ring shape,
The front end face is the flange portion 25b of the second spacer 25.
A sleeve portion 25c extending rearward of the second spacer 25 penetrates the cover 26 and protrudes rearward.

Then, as shown in FIG.
The rear portion 6 is an engagement portion 26b of a tightening tool having a polygonal outer shape, and a large number (15 in the example of FIG. 1) are arranged at regular intervals on a circumference around a central axis on the inside thereof.
) Screw holes 26c... 26c are provided in these screw holes 26c.
27 are screwed respectively.

Next, a process of assembling the die unit 14 will be described.

First, the first and second dies 22, 23, the first and second spacers 24, 2 are placed on the die case 21 from the rear end.
5 is inserted in this order, the male screw 26a of the cover 26 is screwed into the female screw 21d at the rear end of the die case 21, and a predetermined tool is engaged with the tool engaging portion 26b to tighten the cover 26. Put in. In this case, the tightening with the tool may be performed until the front end surface of the cover 26 comes into contact with the rear surface of the flange portion of the second spacer 25, and it is not necessary to tighten with a particularly large torque. Therefore, the internal thread 2
Although 1d and male screw 26a have a considerably large diameter, it is not necessary to use a large tightening tool.

Next, in this state, the die press fitting bolts 27... 27 are screwed into the plurality of screw holes 26 c. Even after the tip of each bolt 27... 27 abuts against the rear surface of the flange portion 25 b of the second spacer 25, if these are evenly tightened, the second spacer 25 moves forward in the die case 21. By being pushed into
The second die 23 and the first 22 are pressed into the tapered surface 21 a at the front end of the die case 21 via the spacer 24.

In this case, the first and second dies 22, 2
27 is performed by evenly tightening the plurality of bolts 27... 27, the overall pressing force is sufficiently large even though the tightening torque for each bolt 27. The first and second dies 2 can be tightened simply by using
2, 23 can be press-fitted into the tapered surface 21a with a required pressing force.

Here, since the front end of the die case 21 expands in response to the press-fitting of the first and second dies 22, 23, for example, as shown by reference numeral c in FIG. The initial outer diameter of the front end of the die case is recorded by stamping or other means, and the outer diameter of the front end of the die case 21 is measured after press-fitting the dies 22 and 23. By calculating the amount of expansion by subtracting the value, the press-fit state of the dies 22, 23 can be determined. By tightening the bolts 27 so that the expansion amount becomes a predetermined amount, the press-fit state of the dies 22 and 23 can be set to an appropriate state.

In this embodiment, the die case 2
Since the outer diameter of the outer peripheral surface 21b at the front end of the die 1 is smaller than the standard outer diameter of the intermediate part and the rear part by the dimension x, as shown by a chain line in FIG. ,
Even if the front end of the die case 21 expands, when the die unit 14 is fitted in the mounting hole 12a of the die block 12, the expanded portion is deleted without interfering with the inner surface of the mounting hole 12a. Without the die unit 14
Can be fitted into the mounting hole 12a.

Therefore, the expansion amount of the front end of the die case can be measured at any time from the initial outer diameter and the outer diameter after the die press-fitting, and the shrink force corresponding to the expansion amount can be appropriately adjusted. Can be maintained.

The die unit 14 assembled as described above is fitted into the mounting hole 12a formed in the die block 12 of the main body of the forging machine following the load receiving member 32 as shown in FIG. And the through-hole 32a provided in the load receiving member 32 and the die unit 1
4, the knockout pin 31 is inserted into the through holes 24 a, 25 a, and 23 b provided in the first and second spacers 24 and 25 and the second die 23, and in this state, the fixing bolt 33 is provided on the outer surface of the die case 21. It is fixed to the die block 12 by being tightened into the recessed portion 21e.

The material b supplied from the upper forging station S1 shown in FIG. 1 is driven into the cavity 22a of the first die 22 by a punch,
The material b is formed into the shape of the cavity 22a, and then discharged from the cavity 22a by the knockout pin 31 and transferred to the lower-stage forging station S3.

The above description is about the case where the die unit 14 according to the present embodiment is applied to the second forging station S2. However, the die unit 14 may be applied to other stations as necessary. It is also possible.

Next, a second embodiment of the present invention will be described.

Die unit 14 'according to this embodiment
Has substantially the same configuration as the die unit 14 according to the above embodiment, and includes first and second
Dies 22 'and 23' and first and second spacers 24 'and 2'
5 'is inserted from the rear end in this order, and the cover 2 is inserted into the female screw 21d' on the inner peripheral surface of the rear end of the die case 21 '.
6 'and the plurality of die press-in bolts 27'... 27 'provided on the cover 26' are tightened, so that the first and second dies 22 'and 23' are connected to the die case 2.
1 ′ is press-fitted into a tapered surface 21 a ′ of the inner peripheral surface at the front end.

Therefore, also in this embodiment,
The bolt 27 '... 2 with a normal force and a normal tool
By tightening 7 ', the first and second dies 22', 2 '
3 ′ is the tapered surface 2 of the inner peripheral surface of the front end of the die case 21 ′.
It is possible to press-fit into 1a 'with a required pressing force.

In the second embodiment, the front end of the die case 21 'is
The projection 21f 'is set so as to project a predetermined amount when it is fitted into the mounting hole 12a'.
4 and 5, an expansion suppressing ring member 28 'as shown in FIGS. 4 and 5 is fitted, and a bolt 34' inserted through bolt holes 28a '... 28a' provided in the ring member 28 '. .. 34 'are fastened to the front surface of the die block 12', so that the die unit 14 'is fixed to the die block 12'. Here, the ring member 28 'is not limited to a rectangular shape as shown, but may be a round shape or another shape.

Therefore, according to this embodiment, when the material is driven into the cavity 22b 'of the first die 22' by the punch during the forging of the material, the first die 22 is formed by the ring member 28 '. Of the first die 22 'and the die case 21' due to the repetition of the impact expansion. Become. Thereby, particularly when the cavity 22b 'is eccentric as in this embodiment, the die or die case is prevented from being damaged when the die or the die case is liable to be damaged due to the fatigue due to the repetition of the impact expansion, and the die case 21' is prevented. In addition, the durability of the first die 22 'is improved.

[0041]

As described above, according to the present invention, the die and the spacer are inserted from the rear end of the cylindrical die case, and the cover member is screwed onto the internal thread provided on the inner peripheral surface of the rear end of the case. After joining, the plurality of press-fit bolts are tightened from the rear surface side of the cover member to press-fit the die into the tapered surface of the die case front end inner circumference via the spacer. By using ordinary bolt tightening tools, the above-mentioned die can be brought into the required state using ordinary bolt tightening tools without the need for a large-scale tool, large labor, and a large work area as in the case of press-fitting the die. Press-fitting becomes possible. Therefore, when the die is changed due to a change in the product shape, the assembling work of the die unit is remarkably facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a pressure forming machine to which a die unit of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of the die unit according to the present embodiment, taken along line AA in FIG.

FIG. 3 is a rear view of the die unit taken along line BB of FIG. 2;

FIG. 4 is a sectional view of a die unit according to another embodiment of the present invention.

FIG. 5 is a front view of the die unit.

FIG. 6 is a cross-sectional view showing the structure of a conventional die unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Forging machine 12a Mounting hole 14 Die unit 21 Die case 21a Tapered surface 22, 23 Die 24, 25 Spacer 26 Cover member 27 Press-fit bolt

Claims (3)

[Claims] 1. A die unit attached to a main body of a heading molding machine, wherein a front end inner peripheral surface is a tapered surface whose diameter becomes smaller toward a front end side, and a female screw is formed on a rear end inner peripheral surface. A cylindrical die case fitted into a circular mounting hole provided in the base case, and an outer peripheral surface having a tapered surface whose diameter becomes smaller toward the front end side, is fitted from the rear to the tapered surface at the front end of the die case. A die, a spacer fitted into the die case so as to be located behind the die, and a cover member screwed to a female screw at the rear end of the die case, and the cover member has A plurality of press-fitting bolts are provided around the center axis of the die unit, which press-fit the die into the tapered surface at the front end of the die case through the spacer by tightening from the rear side of the member. Toss Die unit of a forging machine. 2. The outer diameter of the front end of the die case is such that the outer diameter of the front end of the die case does not become larger than the inner diameter of the mounting hole of the main body even after expansion due to press-fitting of the die into the tapered surface. The die unit of a pressure forming machine according to claim 1, wherein the diameter is smaller than the outer diameter by a predetermined amount. 3. The front end of the die case is set so as to protrude from the front surface of the main body by a predetermined amount when fitted in the mounting hole of the main body, and suppresses the expansion of the front end of the die case outside the protruding portion. The die unit of a pressure forming machine according to claim 1, wherein a ring member to be formed is fitted.