JP3307128B2 - Drawing press type - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a single-action drawing press type called a cushion draw type, and more particularly to a structure for supporting a blank holder with a cushion pin of a die cushion device.

[0002]

2. Description of the Related Art A typical structure of a single action type drawing press type is shown in FIG. This conventional structure is roughly divided into a punch 2 fixed to a holster 1, a blank holder (cushion pad) 3, and a die 4 as an upper die. The blank holder 3 arranged on the outer periphery of the punch 2 is elastically supported so as to be vertically movable by a plurality of cushion pins 5 of a die cushion device (not shown), and forms a lower die 6 together with the punch 2.

When the die 4 as an upper die facing the lower die 6 descends together with the slide (press ram) 7, the peripheral portion of the blank material W previously placed on the lower die 6 becomes The blank material W is constrained by pressing with the die 4, and in the process of descending to the bottom dead center position, the blank material W is narrowed down to the die 4 side by the cooperation of the die 4 and the punch 2 to be formed into a predetermined panel shape. Will be.

In such a press-type structure, as for the bolster 1 to which the punch 2 is fixed, as shown in FIG. 4, the position of the cushion pin 5 is changed according to the size of the molded product, that is, the size of the press die. Are formed in advance so that the cushion pin 5 can be inserted and arranged by appropriately selecting an optimum position from the many pin holes 8, 8. ing.

On the other hand, as shown in FIG. 4, although it is possible to arbitrarily select a predetermined position from among a large number of pin holes 8, 8,. In the vertical and horizontal directions, the bolster 4 has the largest L ₁ and L ₂ dimensions from the center of the
Therefore, the cushion pin 5 cannot be arranged outside the position a.

For this reason, for example, when the size of the press die is increased due to the increase in the size of the molded product, as shown in FIG. 5, one of the existing pin holes 8, 8. The backup plate 9 is attached to the lower surface of the blank holder 3 by bolts 10 while the cushion pin 5 is
Then, the backup plate 9 is brought into contact with the cushion pin 5 so that the force of the cushion pin 5 is transmitted to the blank holder 3 via the backup plate 9.

[0007]

However, in the structure shown in FIG. 5, the connection between the blank holder 3 and the backup plate 9 and the contact position between the backup plate 9 and the cushion pin 5 are offset. Therefore, a bending force is applied to the backup plate 9 when the blank holder 3 is operated, and an excessive force is applied to the bolt 10 connecting the blank holder 3 and the backup plate 9. For this reason, the backup plate 9 and the bolt 10 must have sufficient strength to be rugged, resulting in an increase in size and cost, and a problem in durability. . This phenomenon becomes more conspicuous as the offset amount increases, that is, as the size of the press die increases, so that the size of the molded product that can be molded is necessarily restricted.

Further, in the structure shown in FIG. 5, since the backup plate 9 must be attached from the back side of the blank holder 3 in a state where the punch 2 and the blank holder are combined, workability at the time of attachment and disassembly is required. Has the disadvantage of being extremely bad.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to solve the problem of the strength of a member corresponding to the backup plate and reduce the size and cost of the member. Another object of the present invention is to provide a press-type structure in which the workability of mounting the members is improved.

[0010]

According to a first aspect of the present invention, there is provided a punch, which is disposed around the punch and is elastically supported by a cushion pin of a die cushion device so as to be able to move up and down and together with the punch. A blank holder constituting a lower die, comprising an ascending and descending die as an upper die disposed opposite to the lower die, the blank material pressed and constrained by the blank holder and the die, and a die and a punch. In a drawing press die which is formed by drawing into the die side in cooperation to form a predetermined shape, a vertical guide sliding surface is formed on the outer peripheral surface of the punch, and the punch moves vertically while being guided by the guide sliding surface. The slider is supported by the cushion pin, and a holder support surface is formed on the outer peripheral surface of the slider opposite to the side in contact with the punch, and the slider is brought into contact with the holder support surface. It is characterized in that by supporting the blank holder slider so that.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the vertical dimension of the guide sliding surface and the holder supporting surface is determined by changing the vertical dimension of the guide sliding surface and the holder supporting surface. Is set to be larger than the distance between

According to a third aspect of the present invention, in addition to the configuration of the second aspect, a vertical holder supporting surface and a horizontal supporting surface are provided on an outer peripheral surface of the slider opposite to a side in contact with the punch. Is formed, and the blank holder is fitted to and supported by the stepped portion.

According to a fourth aspect of the present invention, in addition to the configuration of any one of the first to third aspects, a plurality of guide sliding surfaces are formed on an outer peripheral surface of the punch, and each guide sliding surface is provided. An independent slider is provided for each, and a blank holder is supported by the plurality of sliders.

[0014]

According to the structure of the first aspect, the slider is substantially sandwiched between the guide sliding surface on the punch side and the blank holder, and the slider is integrated with the blank holder with respect to the punch. It will move up and down while sliding. Then, the slider receiving the load of the blank holder receives a moment that tries to fall outward with the contact point with the cushion pin as a fulcrum, but the slider itself is backed up by being sandwiched between the punch and the blank holder and restrained. Therefore, the punch and the blank holder disperse and bear the moment in the falling direction. As a result, the slider does not need to be as strong as the conventional backup plate, and it is not necessary to mount the slider from the lower surface of the blank holder, so the workability when assembling and disassembling the slider is also improved. Is done.

According to the second aspect of the present invention, the vertical dimension of the guide sliding surface and the holder supporting surface is set to be larger than the distance between the guide sliding surface and the holder supporting surface. Thereby, the moment in the falling direction applied to the slider can be further suppressed.

According to the structure of the third aspect, a stepped portion including a vertical holder supporting surface and a horizontal supporting surface is formed on the outer peripheral surface of the slider opposite to the side in contact with the punch, and the stepped portion is formed. Since the blank holder is fitted to and supported by the shape part, the blank holder can be assembled to the slider from above, thereby improving the workability when assembling and disassembling the blank holder with the slider. It is further improved.

According to the structure of the fourth aspect, a plurality of guide sliding surfaces are formed on the outer peripheral surface of the punch, independent sliders are provided for each guide sliding surface, and a blank holder is mounted on the plurality of sliders. Due to the support, the number of processing steps and cost can be reduced as compared with the case where the slider is arranged all around the punch.

[0018]

1 and 2 show an embodiment of the present invention, in which parts common to those of the prior art shown in FIGS.

As shown in FIGS. 1 and 2, a slider receiving portion 11 is formed in the outer peripheral surface of a punch 12 fixed to the bolster 1, and the slider receiving portion 11 forms a guide sliding surface. Three wear plates 14 and 15 are fixed in a vertical posture. The slider receiving portion 11 is provided with a slider 16 that can move up and down along the wear plates 14 and 15. The position of the slider 16 is regulated by a give plate 17 and the cushion pin 5 is provided. The slider 16 is elastically supported by a die cushion device (not shown) via the cushion pin 5.

On the outer surface of the slider 16 opposite to the side in contact with the wear plate 14, there is formed a stepped portion 20 composed of a vertical holder supporting surface 18 and a horizontal supporting surface 19 continuous therewith. The blank holder 13 is fitted to and supported by the stepped portion 20 from above.

Here, the vertical dimension S ₁ of the holder support surface 18 is formed to be sufficiently larger than the distance S ₂ from the holder support surface 18 to the wear plate 14. the vertical length S ₄ wear plates 14 and 15 in contact with the dimension S ₃ and the slider 16 is formed larger than the length S ₁ of the holder supporting face 18.

The slider receiving portion 11 is provided with a punch 1
A total of four locations are formed at left and right symmetrical positions on the outer periphery of the slider 2, and a slider 16 similar to that shown in FIGS.

Therefore, according to the above structure, when the die 4 as the upper die is at the top dead center position, the force of the die cushion device (not shown) is transmitted to the slider 16 via the cushion pin 5, and 16 is the blank holder 1
3 and rises to a predetermined position and stands still.

On the other hand, when the die 4 descends during the press forming, the blank holder 13 is pushed down by the die 4, so that the slider 16 descends while being guided by the wear plates 14 and 15 together with the blank holder 13,
When the die 4 moves up again, the slider 16 is pushed up by the cushion pin 5 and returns to the original position together with the blank holder 13.

In the process of raising and lowering the blank holder 13, the step portion 20 of the slider 16 receiving the force of the blank holder 13 and the contact portion between the slider 16 and the cushion pin 5 are offset. Therefore, the slider 16 receives a moment in the outward falling direction with the contact portion with the cushion pin 5 as a fulcrum. However, since the slider 16 is sandwiched between the punch 12 and the blank holder 13 and is backed up by both, the moment received by the slider 16 is distributed to the punch 12 and the blank holder 13 which are in contact with the slider 16. Thus, the punch 12 and the blank holder 13 ultimately bear the burden. As a result, the slider 16 is not required to have such a high mechanical strength,
As a result, it is possible to sufficiently cope with a simple and small structure.

This means that a larger press die can be assembled to the bolster 1 without being restricted by the position of the pin hole 8 for the cushion pin 5 as shown in FIG. A larger molded product can be drawn by a press machine.

Further, since the slider 16 is disposed in the space between the punch 12 and the blank holder 13 so as to be sandwiched between them, it is advantageous in terms of space.
The occupied space for arranging the slider 16 can be reduced.

Further, when mounting the blank holder 13 on the slider 16, it is only necessary to assemble the blank holder 13 from above the slider 16 and fit the blank holder 13 into the stepped portion 20. Workability can be improved.

[0029]

According to the first aspect of the present invention, the holder supporting surface is formed on the outer peripheral surface of the slider which moves up and down along the guide sliding surface on the punch side, on the side opposite to the side in contact with the punch. Since the blank holder is supported so as to contact the holder support surface, the slider is sandwiched between the punch and the blank holder and is backed up by both. In addition, it is possible to disperse the load on the blank holder and load it. As a result, the slider is not required to have such a high strength, and the slider can have a simple and small structure, so that the cost can be reduced, the durability is improved, and the installation space is further improved. The above is also advantageous. And since it becomes a structure advantageous in intensity | strength as mentioned above, the size of a press type | mold is not restricted by the restriction | limiting of the pin hole position for the bolster side cushion pins unlike the conventional one, A larger press can be drawn using a large press die with a small press machine. In addition, since it is not necessary to mount the slider on the lower surface of the blank holder as in the related art, the workability at the time of assembling and disassembling is greatly improved.

According to the second aspect of the present invention, the length of the guide sliding surface and the holder supporting surface in the vertical direction is set to be larger than the distance between the guide sliding surface and the holder supporting surface. The moment can be further suppressed.

According to the third aspect of the present invention, a stepped portion including a vertical holder supporting surface and a horizontal supporting surface is formed on the slider, and a blank holder is fitted to and supported by the stepped portion. As a result, the position stability of the blank holder with respect to the slider is improved, and the blank holder can be attached to and detached from the slider from above, thereby further improving the workability when assembling and disassembling the press die. .

According to the fourth aspect of the present invention, a plurality of independent slicers are provided on the outer periphery of the punch, and the blank holder is supported by the plurality of sliders. For example, the sliders are arranged on the entire periphery of the punch. There is an advantage that the number of processing steps and cost can be significantly reduced as compared with the case.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of the present invention, and is a cross-sectional view taken along line aa of FIG. 2;

FIG. 2 is a plan view of a lower die in FIG. 1;

FIG. 3 is a sectional view showing a basic structure of a conventional drawing press die.

FIG. 4 is a sectional view showing another structure of a conventional drawing press die.

FIG. 5 is a plan view of the bolster shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Die (upper type) 5 ... Cushion pin 6 ... Lower type 11 ... Slider receiving part 12 ... Punch 13 ... Blank holder 14, 15 ... Wear plate (guide sliding surface) 16 ... Slider 18 ... Holder supporting surface 19 ... Horizontal Support surface 20: stepped portion W: blank material

Continuation of the front page (56) References JP-A-3-66423 (JP, A) JP-A-4-367326 (JP, A) JP-A-62-84836 (JP, A) Jpn. , U) Japanese Utility Model Application Showa 59-58523 (JP, U) Japanese Utility Model Application Laid-Open 2-32322 (JP, U) Japanese Utility Model Utility Model 3-70820 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) B21D 24/00 B21D 24/04

Claims (4)

(57) [Claims] 1. A punch, a blank holder disposed around the punch, elastically supported by a cushion pin of a die cushion device so as to be vertically movable and constituting a lower die together with the punch, and a lower die An upper die that can be raised and lowered is provided as an upper die that is opposed to the die. A vertical guide sliding surface is formed on the outer peripheral surface of the punch, and a slider that moves up and down while being guided by the guide sliding surface is supported by the cushion pin; A holder support surface is formed on the outer peripheral surface opposite to the side in contact with the punch, and the blank holder is supported on the slider so as to contact the holder support surface. Drawing press type, characterized in that is. 2. The vertical dimension of the guide sliding surface and the holder supporting surface is set to be larger than the distance between the guide sliding surface and the holder supporting surface. Drawing press type. 3. A stepped portion including a vertical holder supporting surface and a horizontal supporting surface is formed on the outer peripheral surface of the slider opposite to the side contacting the punch, and the blank holder is mounted on the stepped portion. 3. The device according to claim 2, wherein the fitting is supported.
The drawn press die described. 4. A plurality of guide sliding surfaces are formed on an outer peripheral surface of the punch, independent sliders are provided for each guide sliding surface, and the plurality of sliders support a blank holder. The drawing press die according to claim 1.