KR20140031505A - A device for controlling blank holding force - Google Patents

Abstract

A device for controlling a blank holding force which provides a stable blank holding force to a panel of a forming-by-drawing machine is disclosed. The present invention includes: an upper forming part installed on the upper part of the panel of the forming-by-drawing machine, which produces products in a certain shape; a lower forming part which forms the panel by drawing cooperatively with the upper part and fixes the panel; a repulsive force providing part which is installed on the lower part of the panel and then provides a repulsive force to stabilize a blank holding force the panel receives. [Reference numerals] (AA) Cup

Description

Blank holding force control device {A DEVICE FOR CONTROLLING BLANK HOLDING FORCE}

The present invention relates to a blank holding force control device, and more particularly, to provide a constant blank holding force is transmitted to all the sides of the panel during the primary primary drawing molding, and by implementing this, the second crack is generated in the panel It relates to a control device for preventing that.

The present invention relates to a blank holding force control device of a drawing molding facility, and more particularly, by using a compressible elastic material located in the upper or lower mold lower portion of the panel that can be generated during the molding process by transmitting a constant repulsive force to all sides of the panel. It relates to a control device for preventing cracks.

In general, the drawing process among the various processes for manufacturing the panel is an important process that greatly affects the quality of the panel.

The drawing molding facility used for this drawing process is comprised so that it may have an upper mold | type, a lower mold | type, and a blank holder, and it has a structure which shape | molds a product of a predetermined shape by these vertical motions.

The general drawing molding equipment is operated to complete the product while the upper mold and the lower mold are completely matched while the panel to be molded is held by the die surface of the upper die and the blank holder.

At this time, the die surface of the upper die and the blank surface of the die holder are the first contacting parts of the panel to control the state of the material inflow generated during molding to have an absolute influence on the formability, so as to obtain excellent and stable molding quality. The holding force by the die surface of the molding and the die surface of the blank holder should be formed so as to hold the edge portion of the mold in a proper state.

As shown in FIG. 1A, the holding force of the panel 1 by the upper die 2 and the blank holder 3 is usually caused by the upper die 2 and the blank holder 3 contacting the panel 1 at a predetermined pressure. This is due to the generated frictional force, and additionally, the bead 4 is protruded on the die surface of the blank holder 3 to adjust the holding force by the size or height of the bead 4.

However, since the work to adjust the size or height of the bead (4) must be made directly by the operator in the field, there is a problem of increasing the workload, in particular the size or height of such a bead (4) by the experience of the operator If it is determined that it is not adjusted to fit the drawing has a problem that adversely affects the quality of the product.

In addition, during the drawing process using the existing single-acting press, the blank holding force acting on the panel 1 continuously increases, and in the latter part of the drawing process, an excessive blank holding force is applied to cause a defect such as breaking of the drawing product. There was a downside.

In addition, the cushion pin 6 provided in the bolster 5 in the forming press apparatus for forming the inner panel of the hood for a conventional vehicle shown in FIG. 1b is also already set the elastic force to the panel holding force to the extent desired by the operator ( It still shows its limitations in delivering to 1).

In addition, as shown in FIG. 1B, in the case of the cushion pin 6 used as the driving source of the blank holding force, the pressure increases linearly during the molding process, thereby limiting the expansion of the moldable range (product molding depth). It has been.

The present invention is to prevent the blank holding force is increased during the molding process as described above, in particular, by using a single-acting press rather than a double-acting press to maintain a constant blank holding force during the drawing process, the drawing processing is made smoothly There is this.

In relation to the blank holding force control device, Korean Patent Application Publication No. 10-2006-0109715 (October 23, 2006), 'blanking holding force control device for drawing molding equipment' and Korean Patent Publication No. 10-0471275 (2005) 02. 01) can be referred to 'pressing apparatus for the simultaneous molding of dissimilar panels'.

However, the 'blanking holding force control device of the drawing molding equipment' is to form a sufficient blanking holding force through the suction force generating unit for generating a suction force in the die surface to the blanking holder, the blanking holding force is gradually increased during the molding of the panel generates cracks There is still a problem that can be, and the 'simultaneous panel pressing device for heterogeneous panel' also press-molded the heterogeneous panel requiring a different blank holding force with a single press device to constantly maintain the blank holding force to be solved by the present invention. The problem to be solved is different from the maintenance, and no solution has been proposed to maintain the blank holding force constant during the molding process to prevent cracking of the plate.

(Prior Art 1) Korean Patent Publication No. 10-2006-0109715 (October 23, 2006) (Prior art 2) Korean Patent Publication No. 10-0471275 (2005.02.01)

The present invention has been proposed to solve the above problems, and is an apparatus for controlling the blank holding force of a panel to be processed during single-acting press processing so that the blank holding force is uniformly transmitted to all sides of the panel. An object of the present invention is to provide a blank holding force control device provided with a compressible elastic material (rubber, spring) under the die.

The blank holding force control apparatus according to an embodiment of the present invention for achieving the above object, together with the upper mold and the upper mold installed in the upper part of the panel in a drawing molding facility for forming a panel to manufacture a product of a predetermined shape A lower mold part for drawing the panel and fixing the panel and a repulsive force providing part installed at a lower part of the panel and providing a repulsive force so that a blank holding force transmitted to the panel is constantly transmitted; And a control unit.

      In addition, the lower die portion includes a lower die supporting the panel, a die holder provided on both sides of the lower die, and a die plate for fixing the die holder, and a lower plate for supporting the die plate is fixedly installed under the die plate. The repulsive force providing unit is formed of a compressible material.

     In addition, the repulsive force providing unit is characterized in that any one of the elastic rubber or the spring whose diameter and height is adjusted so that the blank holding force is constantly transmitted to the panel.

The present invention can achieve the following various effects due to the technical configuration as described above.

First, there is an advantage of eliminating the inconvenience of using a complicated structure and expensive double-acting press during normal press working.

Second, there is an advantage that the drawing process of the same panel as that of using a double-acting press is possible by using a single-acting press which is simple in structure and inexpensive than the double-acting press.

Third, there is an advantage that the blank holding force can be controlled by changing only the diameter and height of the compressible elastic material so that the blank holding force required for the panel is calculated in advance and then the blank holding force is constantly transmitted to all sides of the panel.

Fourth, in the case of a thin panel requires a relatively small blank holding force bar according to the present invention there is an advantage that can be implemented by changing the diameter and height of the compressible elastic material so that only a blank holding force of a precise degree required.

Figure 1a is a block diagram provided with a blank holder for transmitting a blank holding force to a conventional panel.
1B is a side sectional view of a forming press apparatus for forming an inner panel of a conventional vehicle hood.
Figure 2a is a configuration diagram installed elastic rubber which is a compressible elastic material capable of transmitting the blank holding force of the present invention.
Figure 2b is a schematic diagram of a spring installed a compressible elastic material capable of transmitting the blank holding force of the present invention.
Figures 3a and 3b is a state in which a constant blank holding force is transmitted to the panel in accordance with the operation of the present invention.
Figure 4 is a view comparing the compressive load according to the diameter and height of the elastic rubber of the compressible elastic material of the present invention.
Figure 5a is a diagram showing the relationship of the compression load according to the compression distance of the elastic rubber of the compressible elastic material of the present invention.
Figure 5b is a working pressure diagram from the start of molding to the completion of molding when using the elastic rubber of the compressible elastic material of the present invention.
Figure 6 is a view showing the thin cup drawing experiment results using the present invention.
7 is a view showing the U bending test results by applying the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2A, the blank holding force control apparatus of the present invention includes an upper mold portion 100 installed above the panel 1 in a drawing molding facility for forming the panel 1 to manufacture a product having a predetermined shape. The lower mold part 200 for drawing the panel 1 together with the upper mold part 100 and fixing the panel 1 and the blank holding force installed in the lower part of the panel 1 are transmitted to the panel 1. It includes a repulsive force providing unit 300 made of a compressible elastic material to provide a resilient force to be constantly transmitted.

And, Figure 2b is implemented by using a spring as a compressible elastic material of the blank holding force control apparatus of the present invention.

In the single-acting press to which the present invention is applied, the upper plate 140 is mounted on the press which reciprocates up and down by the action of the single-acting hydraulic cylinder, and the punch holder 150 and the upper die pressing device 120 It is installed.

A punch 130 for drawing a panel through the center of the upper die 110 is coupled to the lower portion of the punch holder 150, and a lower die 210 for supporting the panel 1 is provided at the bottom of the panel 1. The die holder 220 and the die plate 230 are provided.

An elastic rubber that provides repulsion by adjusting its diameter and height to match the value of the blank holding force to be transmitted to the panel 1, which can be seen as the core of the present invention, is installed under the lower die 210.

The elastic rubber 310, which is a compressible elastic material, is compressed until the lower surface portion 160 of the upper die reaches the upper surface 250 of the die holder 220, and thus the reaction force due to the action and reaction is lowered. This repulsive force is a constant blanking holding force transmitted to the panel 1.

That is, the repulsive force formed in the elastic rubber from the start of molding to the end of molding throughout the drawing process acts as a driving source of the blanking holding force.

To this end, the present invention, first, to grasp the load-displacement characteristics of the compressible elastic material through various kinds of material compression experiments of different diameters and heights of the compressible elastic material (elastic rubber, spring) before the drawing processing of the panel, To select a compressible elastic material having the blank holding force necessary for the drawing processing of the panel.

Figure 4 shows the load change according to the diameter of the rubber which is one of the compressible elastic materials, it can be seen that the larger the diameter of the rubber, the greater the compression load value at the same compression distance.

As shown in Fig. 4, when the lower die for supporting the panel is lowered while compressing the elastic rubber, which is a compressible elastic material installed at the lower portion thereof, the compression distance generated in the rubber is 17 mm. If the panel requires a blank holding force corresponding to this compression load of 11.5 KN, an elastic rubber having a diameter of 60 mm and a height of 57 mm is installed at the bottom of the lower die to configure a constant blank holding force to be transmitted to the panel.

In the same principle, when the blank holding force required for the panel 1 is equivalent to 6.2 KN, an elastic rubber having a diameter of 50 mm and a height of 57 mm is installed below the lower die die 210 so that the blank holding force is applied to the panel 1. It is configured to be delivered to a constant.

5A is a view showing the compression distance and the compressive load relationship by using the elastic rubber having the diameter and height as described above.

Due to the configuration as described above, in the case of a cushion pin installed in the conventional blank holder lower portion and the predetermined elastic force is transmitted, a problem in which the operator cannot transmit the desired blank holding force is solved.

In addition, when a high pressure is applied to the panel 1, a crack occurs. On the contrary, when a low pressure is applied, the panel 1 is wrinkled. In particular, when drawing a thin plate such as an ultra-thin plate, the blank is blank. If the holding force is high, cracks are generated in the punch shoulder portion in contact with the punch, and thus the blank holding force has to be set very low. Therefore, the usefulness of the present invention will be greater if very small blank holding force is required.

Figure 5b shows the operating pressure diagram when using the elastic rubber of the present invention corresponding to the blank holding force applied to the panel 1, compared to the conventional cushion pin corresponding to the conventional working pressure is constant during the molding is completed and completed You can see that it is maintained.

Figure 6 shows the experimental results of the stainless steel thin cup drawing having a thickness of 0.15 mm, in particular Figure 6 (a) is the result of processing by the conventional method of increasing the blank holding force according to the processing depth, drawing through It can be seen that the fracture occurred in the punch shoulder portion during processing, Figure 6 (b) is a result of the experiment when using the compressible elastic material of the present invention that the punch shoulder portion is not completely formed without fracture You can check it.

In the case of using the elastic rubber, which is a compressible elastic material as described above, the blank holding force acting on the panel 1 is different as the diameter thereof is different, and the applicant has a diameter of 40 mm and 60 mm, respectively, in order to confirm this. U bending test was performed using the same rubber member as 60 mm, which is shown in FIG. 7.

FIG. 7A is a case where an elastic rubber having a diameter of 40 mm and a height of 60 mm is used, and FIG. 7B is a case where an elastic rubber having a diameter of 60 mm and a height of 60 mm is used. As the holding force is different, the shape of the product is different.

In another embodiment of the present invention, the repulsive force providing unit 300 is formed of a spring 320 that can adjust its diameter and height to correspond to the value of the blank holding force to be transmitted to the panel 1.

That is, in consideration of the type and thickness of the panel 1, a spring to which a constant blank holding force is transmitted is installed below the lower die 210 so that no crack is generated in the panel 1.

As another method of selecting the rubber material constituting the repulsive force providing unit 300 of the present invention, the spring 320 also considers the compression load generated in the spring according to the compression length through the experiment in advance of the height and diameter It is selected to transmit a constant blank holding force.

In the blank holding force control apparatus of the present invention, the lower die portion 200 includes a die die 210 supporting the panel 1, a die holder 220 provided on both sides of the die die 210, and the die holder 220. It includes a die plate 230 for fixing, the lower plate 240 for supporting the die plate 230 is fixedly installed below the die plate 230, the repulsive force providing unit 300 is made of a compressible material Characterized in that formed.

The present invention is characterized in that it further comprises a die holder 220 is installed on both lower sides of the lower die die 210 to control the height of the upper die 110 during the drawing process.

Referring again to FIG. 2A, die holders 220 are installed on both lower sides of the lower die 210 supporting the panel 1, and the die holders 220 are disposed on the upper surface of the die plate 230 supporting them. To be coupled, the die plate 230 is supported by the lower plate 240.

The die holder 220 plays a role in which the upper die 110 is no longer lowered while the upper die 110 coupled to the upper plate 140 is lowered during the drawing process of the panel 1.

Because of this, the compressible elastic material (elastic rubber, spring) installed under the lower die die 210 maintains the compressed state by a certain height, and the repulsive force, that is, the blank holding force, generated while maintaining the compressed state is constant across the front of the panel. Is to be delivered.

In the blank holding force control apparatus of the present invention, the upper die portion 110 includes an upper die 110, an upper die pressing device 120, an upper plate 140, a punch 130, and a punch holder 150. It is done.

The upper die 110 serves to closely adhere the panel 1 together with the lower die 210, and the upper die 110 is fixed to the panel by an upper die pressing device 120 fixed to the upper plate 140. Press (1).

Thereafter, the punch 130 provided at the center of the upper plate 140 is draw-molded while moving downward.

Referring to Figure 3a will be described the operation of the blanking holding force control apparatus of the present invention.

When the upper plate 140 is mounted on the press for reciprocating up and down, and then descends vertically, the upper die pressing device 120 fixed to the upper plate 140 and the upper die 110 are interlocked to move downward vertically. While pressing the lower die die 210 and the panel 1 installed on the compressible elastic material.

At this time, the resilient force is generated while the compressible elastic material is compressed until the lower surface portion 160 of the upper die reaches the upper surface portion 250 of the die holder, and the repulsive force is a blank holding force acting on the panel.

Thereafter, when the upper plate 140 is continuously lowered, the upper die 110 is no longer lowered by the die holder 220, and the punch mounted to the upper plate 140 causes the panel 1 to lower the die die 210. By drawing between them, a cup of the desired shape is formed.

The blank holding force is kept constant during the cup forming process.

3B is a view showing an operation process when the repulsive force providing unit 300 of the present invention is a spring 320, the operation process is the same as the elastic rubber 310 of the resilient force providing unit 300 is a compressible elastic material Omit.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

1 panel 100 upper part
110: upper die 120: upper die pressurizing device
130: punch 140: upper plate
150: punch holder 160: lower surface of the upper die die
200: lower die 210: lower die
220: die holder 230: die plate
240: lower plate 250: upper surface of the die holder
300: resilience providing unit 310: elastic rubber
320: spring

Claims (3)

An upper mold part 100 installed on the panel in a drawing molding facility for forming a panel 1 to manufacture a product having a predetermined shape;
A lower mold part 200 which draws the panel 1 together with the upper mold part 100 and fixes the panel 1;
A repulsive force providing unit 300 installed below the panel 1 to provide a repulsive force so that the blank holding force transmitted to the panel 1 is constantly transmitted; Blank holding force control device comprising a.
The method according to claim 1,
The lower die portion 200 includes a lower die die 210 supporting the panel 1, a die holder 220 provided on both sides of the lower die die 210, and a die plate 230 for fixing the die holder 220. ),
The lower plate 240 supporting the die plate 230 is fixed to the lower portion of the die plate 230,
The repulsive force providing unit 300 is a blank holding force control device, characterized in that formed of a compressible material.
The method according to claim 2,
The repulsive force providing unit 300 is a blank holding force control device, characterized in that any one of the elastic rubber 310 or the spring 320 is adjusted in diameter and height so that the blank holding force is constantly transmitted to the panel (1) .

Images