KR100804962B1 - Equipment for measuring of twisting spring-back - Google Patents

Abstract

An equipment for measurement of spring-back distortion is provided to develop a measuring equipment that is capable of generating spring-back distortion to enable the particular part to be designed by considering spring-back distortion when manufacturing a particular part. An equipment for measurement of spring-back distortion includes: a bottom mold member(10) having a forming groove(11) bent to a predetermined radius of curvature such that the other side is longer than one side in a pair of facing sides in the longitudinal direction; a blank(20) laid down above the bottom mold member to cover the forming groove; a top mold member(30) that is disposed above the blank and presses residual parts except a part corresponding to the forming groove; and a punch member(40) inserted into the forming groove by applying force from the upper side of the blank to the forming groove of the bottom mold member to change shape of the blank according to that of the forming groove.

Description

Equipment for Measuring of Twisting Spring-back}

Conceptual diagram showing the type of springback of Figure 1,

Figure 2a is a schematic side view showing a conventional mold apparatus;

Figure 2b is a perspective view of a specimen for measuring a conventional spring back,

3 is a schematic cross-sectional view showing a measuring device of a torsion springback according to the present invention;

4 is a block diagram showing a main configuration of the apparatus according to the present invention;

5a is a perspective view showing a specimen molded by the apparatus according to the present invention;

Figure 5b is a view showing a state after trimming the specimen of Figure 5a,

Figure 6 is a perspective view showing the height measurement site for the measurement of the amount of torsion springback in the final specimen molded by the device according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: lower mold member 11: forming groove

12: protruding bead 20: blank

21: Psalm 22: groove

23: bead portion 24: half-closed portion

25: final specimen 30: upper part member

32: groove 40: punch member

The present invention relates to an apparatus for measuring torsion springback, and more particularly, it is possible to compensate for the shape change due to the torsion springback by measuring the torsion springback for a specific material type and thickness in advance and reflecting it in the design. To a torsion springback measuring device.

Generally, a bending mold is used to shape a plate-shaped steel sheet into a finished product of a desired shape.

This bending mold is applied to a press apparatus, which places the material on a die surface having a profile corresponding to the outward direction of the finished product and presses it at a predetermined pressure by a punch at the top to bend the material to a desired angle and shape.

However, the bending mold performs various angles and shape bending by using a punch and a die, and the material may be restored to its original state even if a force below the elastic limit is applied or a force higher than the elastic limit. This is called springback.

When the springback phenomenon is classified by type, as shown in FIG. 1, the springback (A) generating an angle change by the elastic recovery of the edge of the component, the wall bending springback (B) bending the wall of the component, and the component Twisting spring back (C) and the like.

When designing the mold, it is necessary to consider the springback by elastic recovery so that the part can be manufactured in the desired shape. Since the springback is different depending on the metal material and the shape of the part, it is difficult to quantitatively measure the springback of a specific part There is a problem, and in particular, the method of measuring the torsion springback has not been presented to date.

However, conventionally, the U bending test method as shown in Figs. 2A and 2B was used as a simple method for measuring the springback.

As shown in FIG. 2A, a die 1 having a predetermined molding groove 1a is provided in the related art, and the blank holder 2 is disposed so that the molding groove 1a is not covered on the upper portion of the die 1. The blank 3 is inserted between the die 1 and the blank holder 2, and then the die 1 and the blank holder 2 are pressed to prevent the blank 3 from moving.

After the punch 4 is disposed on the blank 3, the punch 4 is lowered, and the punch 4 applies a force to the blank 3 to form the forming groove of the die 1. The blank 3 is pushed into 1a), and the blank 3 becomes a specimen 5 of a predetermined shape as shown in Fig. 2B.

Therefore, in the related art, after fabricating the specimen 5 as shown in FIG. 2B by the above-described apparatus, the springback generated from the specimen 5 was measured, and the springback generated from the specimen thus manufactured is different depending on the situation. There is a problem in that it is impossible to represent a value and measure it quantitatively.

There may be several reasons why quantitative measurement of the springback by the conventional apparatus is impossible, and most representatively, when the punch presses the blank and pushes it into the forming groove formed in the die, the force is biased without being uniformly applied to the blank. For losing.

As described above, when a biasing force is generated in the punch, the blank cannot be uniformly entered into the forming groove, which causes a problem in that the deformation of the blank is also uneven, resulting in a large amount of variation in the measurement of the springback.

Moreover, since a mold having a symmetrical shape has been used in the related art, since a torsion phenomenon cannot be generated, a springback due to torsion cannot be measured.

The present invention has been proposed to solve the above problems, the object of which is to develop a measuring device that can generate a torsion springback to be designed in consideration of the torsion springback in the manufacture of a particular part.

The present invention for achieving the above object is a lower mold having a shape groove bent in a predetermined radius of curvature so that the length of the other side is longer than the length of one of the pair of sides in the longitudinal direction facing each other absence;

A blank placed on the lower mold member so that the molding groove is covered;

An upper mold member which is disposed on the blank and presses a remaining portion except for a portion corresponding to the forming groove;

And a punch member which is inserted into the forming groove by applying a force toward the forming groove of the lower mold member on the blank so that the blank is deformed into the shape of the forming groove.

In addition, at least two protruding beads are provided in the lower mold member facing each other at the edge of the forming groove, the upper mold member is characterized in that the groove is provided to accommodate the projecting bead.

In addition, the blank is longer than the length of the forming groove is characterized in that both ends of the blank when pressed into the forming groove by the punch member to be in the form of a half-closed out of the forming groove.

In addition, the radius of curvature of the forming groove is characterized in that 500 ~ 700mm.

Figure 3 is a schematic cross-sectional view showing a measuring device of a torsion springback according to the present invention, Figure 4 is a block diagram showing the main configuration of the device according to the present invention, Figure 5a shows a specimen molded by the device according to the present invention Figure 5b is a view showing a state after trimming the specimen of Figure 5a, Figure 6 is a perspective view showing the height measurement site for the measurement of the amount of torsion springback in the final specimen molded by the apparatus according to the present invention.

First, the configuration of the present invention will be described with reference to FIG.

As shown in FIG. 3, the present invention is largely composed of a lower mold member 10, a blank 20, an upper mold member 30, and a punch member 40. As shown in FIG.

The lower mold member 10 is a component forming the lower part of the mold in a conventional mold process, the lower mold member 10 is provided with a molding groove 11 having a predetermined depth and length.

As shown in FIG. 4, the forming groove 11 is not a simple straight shape, but is bent in a predetermined radius of curvature.

That is, two sides of each of the forming grooves 11 face each other, and the length of the other side 11b is greater than the length of any one side 11a of the pair of longitudinal sides facing each other. It is long so as to form a curved shape as a whole.

When the forming groove 11 is bent in this manner, a blank, which will be described later, is placed on the lower mold member 10 and pressed to form the molded specimen in accordance with the shape of the forming groove 11. The difference occurs, which causes both sides of the specimen to be deformed asymmetrically to measure the torsional springback of the specimen having a predetermined length.

That is, the forming groove 11 of the bent shape in the lower mold member 10 is to form the blank 20 asymmetrically in order to experimentally simulate the non-rim springback phenomenon caused by the left and right asymmetrical deformation. .

According to the experiment, it was found that the curvature radius of the forming groove 11 is the most preferable for measuring the torsional springback because the asymmetrical deformation of the molded specimen is good.

In addition, in order to minimize the measurement deviation of the torsion springback by inducing a uniform deformation into the forming groove 11 into the forming groove 11 during molding, both sides of the forming groove 11 in the lower mold member 10 Protruding bead 12 is good to be provided.

The protruding bead 12 is to be provided in at least two places facing each other of the edge of the forming groove 11, it is preferably provided to maintain a predetermined interval with the edge of the forming groove (11).

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When the protruding bead 12 is provided on the lower mold member 10, the blank 20 is placed on the lower mold member 10 so that the blank 20 is inserted into the molding groove 11 by the punch member 40 which will be described later. Hold the blank 20 to prevent the lower mold member 10 and the upper mold member 30 from moving when entering, so even if the force applied to the punch member 40 is deflected to either side, the lower mold member 10 is irrespective of the deflection force. There is an effect that the blank 20 is constantly introduced on both sides of the uniform deformation is induced.

On the other hand, a blank 20 is placed on the upper portion of the lower mold member 10 as shown in Figure 4, the blank 20 is the molding groove when the molding groove 11 is provided in the lower mold member 10 (11) is placed to cover, when both the forming groove 11 and the protruding bead 12 is provided so that both the forming groove 11 and the protruding bead 12 is covered.

In particular, the blank 20 is preferably provided longer than the length of the forming groove 11, the reason is that the blank (20) formed when the blank 20 is pressed into the forming groove (11) 20) In other words, both ends of the specimen 21 are intended to form a half-closed form halfway in the forming groove 11, as shown in Figure 5a.

Both ends of the specimen 21 form a semi-closed shape so that the blanks 20 are uniformly introduced into the forming grooves 11 at both sides of the forming grooves 11 in which the protruding beads 12 are not formed. This is to induce uniform deformation of the specimen 21 even when the protruding bead 12 is not formed, as the protruding bead 12 is formed on the lower mold member 10.

The blank 20 is generally not limited to its shape as long as it meets the above requirements, but is different from the length of one side 11a of a pair of longitudinal sides facing each other, as shown in FIG. 4. If the length of the side (11b) of the forming groove 11 is bent in a predetermined curvature radius as a whole, the blank 20 is also bent so as to cover the forming groove 11 as a whole to correspond thereto It is advantageous to be provided for uniformly forming the blank 20.

As such, when the blank 20 is placed on the lower mold member 10, the upper mold member 30 is disposed on the blank 20 so as to coincide with the lower mold member 10.

Here, the upper mold member 30 presses the remaining portions except for the portions corresponding to the forming grooves 11 among the entire portions of the blank 20, typically the lower mold member 10 and the upper mold member 30. Is mounted on a press (not shown) to press the blank 20 inserted therebetween to not move.

In this case, when the protruding bead 12 is formed in the lower mold member 10, the upper mold member 30 is also inserted into the upper part member 30 in the middle corresponding to the protruding bead 12. It is preferable that a recess 32 is provided to hold the blank 20.

The groove 32 may accommodate the protruding bead 12 when the blank 20 is not present. Thus, when the upper mold member 30 is placed on the lower mold member 10, the protrusion bead 12 and the groove 32 are formed. Make sure that other parts that do not form) are in close contact.

Meanwhile, while the blank 20 to be molded is inserted between the lower mold member 10 and the upper mold member 30, the blank 20 is applied to the blank 20 by applying a predetermined force to the lower mold member 10. The punch member 40 is disposed between the upper mold member 30 so as to be deformed in the same shape as the molding groove 11 of.

The punch member 40 is disposed between the upper mold member 30 and applies a force toward the molding groove 11 of the lower mold member 10 on the blank 20 to form the blank 20 in the molding groove 11. By pushing inwards, the blank 20 is deformed in the shape of the forming groove 11.

Thus, a specimen made by the apparatus according to the present invention is shown in FIG. 5A, wherein in the specimen 21 formed by molding the blank 20, the groove part 22 corresponding to the forming groove 11 is formed. The bead part 23 and the half-close part 24 corresponding to the protruding bead 12 are formed.

In this state, the bead 23 and the half-closed part 24 are trimmed and removed, leaving only the groove part 22 as shown in FIG. 5B.

By removing the bead 23 and the half-closing portion 24 having a predetermined rigidity from the specimen 21, elastic recovery occurs in the groove portion 22 having a predetermined length and torsion springback occurs.

As such, the height of the upper edge of the groove portion 22 was measured for the final specimen 25 in which the torsion springback occurred, as shown in FIG. 6. The height difference between the planar plane and the other point is measured and used as a measure of the amount of torsional springback.

Therefore, the torsion springback in the material can be evaluated with the height difference obtained from the final specimen 25 for each material. Therefore, when forming a part of a predetermined shape using a material, such torsion springback is taken into consideration. It can be reflected in the design to compensate for the shape change caused by torsion springback in the future.

In the above, the present invention has been described in detail by using the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments, and those skilled in the art may be configured within the scope of the present invention. Substitution and modification of the elements are possible but this also belongs to the rights of the present invention.

According to the present invention as described above, it is possible to quantitatively analyze the torsion springback caused by non-uniform deformation due to the production of asymmetrical specimens. Considering the springback can be reflected in the design, there is a unique effect to compensate for the shape change caused by the torsional springback in the future.

Claims (4)

A lower mold member having a forming groove 11 bent at a predetermined curvature radius such that the length of the other side 11b is longer than the length of one side 11a of the pair of sides facing each other. 10; A blank 20 placed on the lower mold member 10 so that the molding groove 11 is covered; An upper mold member 30 disposed on the blank 20 to press the remaining portions except for the portions corresponding to the forming grooves 11; The punch member is inserted into the forming groove 11 by applying a force toward the forming groove 11 of the lower mold member 10 on the blank 20 so that the blank 20 is deformed in the shape of the forming groove 11 ( 40); measuring device of torsion springback comprising a. According to claim 1, At least two of the edges of the forming groove 11 in the lower mold member 10 is provided with a protruding bead 12, the upper mold member 30 is provided with the protruding bead 12 Measurement device of torsion springback, characterized in that provided with a groove (32) to accommodate. According to claim 1, wherein the blank 20 is longer than the length of the forming groove 11 is provided when both ends of the blank (20) when pressed into the forming groove 11 by the punch member (40) Measuring device for torsion springback, characterized in that to be in the form of half-closed halfway in the forming groove (11). The torsion springback measuring device according to any one of claims 1 to 3, wherein the radius of curvature of the forming groove is 500 to 700 mm.

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