KR102178739B1 - Apparatus for bend-forming plate - Google Patents

Abstract

The present invention relates to a bending molding device, in which springback is measured and corrected continuously during molding of the material, in order to compensate the springback regardless of the physical properties of an input material. The bending molding device includes: a fixed die; a pair of pivoting punches which bend the material at a predetermined angle by relative movement with respect to the die, and can be rotated so that the angle with respect to the die is variable; and an angle adjusting unit installed adjacent to the die to adjust the angle of the pivoting punches when the pivoting punches press against the material.

Description

Bending molding device {APPARATUS FOR BEND-FORMING PLATE}

The present invention relates to a bending molding apparatus capable of continuously measuring and correcting a spring back during molding of a material such as a thin plate.

Due to the trend of increasing the strength of materials according to environmental and safety regulations, the cases in which simple bending molding has to be applied rather than using the stretching of the material are gradually increasing. Such bending molding is not a deformation that is stretched or reduced by constraining a target material, but is a processing method requiring only local deformation. Where local deformation occurs, tension and compression deformations are relatively large in the thickness direction of the material, resulting in a spring back phenomenon.

The springback of a material, one of the biggest obstacles in bending molding, is caused by complex causes such as the elastic modulus of the material and the stress distribution in the thickness direction, and predicts and corrects the springback based on the physical properties of the target material. Various methods have been proposed to do so, but it is not easy to accurately predict springback.

In particular, high-strength materials have a problem in that physical property deviations are relatively large due to various causes even if they are produced by the same composition and process. Therefore, springback is theoretically applied by applying the springback prediction equation of a high-dimensional function to the properties of the target material. Even if a mold capable of correcting is designed, if a different material within the physical property deviation is introduced, the mold cannot be corrected as much as expected for spring back, resulting in a problem with the shape fixability of the final product.

On the other hand, since mass production of a product is made in a continuous process, stopping the press during production and correcting the product or correcting defects such as spring back after final molding becomes a factor that hinders the productivity of the product.

(Patent Document 1) KR 423676 B1

Accordingly, the present invention provides a bending molding apparatus capable of securing shape freeze of the final product by continuously measuring and correcting the spring bag during material molding so that the spring bag can be corrected regardless of the physical properties of the material to be input. It has a purpose to provide.

Bending molding apparatus according to an embodiment of the present invention, a fixed die; At least one pivoting punch capable of bending the material at a predetermined angle by relative movement with respect to the die and rotatable so that the angle with respect to the die is variable; An angle adjusting unit installed spaced apart from the die and configured to adjust an angle of the pivoting punch when the pivoting punch presses against the material; And a bending angle measuring unit disposed away from the die to detect a bending angle of the material, wherein the angle adjusting unit includes: a motor installed on a support part spaced apart from the die; A transfer screw installed on the support and rotated by the motor; A movable nut screwed to the transfer screw and moved according to the rotation of the transfer screw; And a guide block mounted on the movable nut to move according to the movement of the movable nut, and guide the movement of the rotation punch while in contact with the rotation punch, and further comprising a control unit connected to the bending angle measurement unit and the motor. Including, the control unit calculates the bending angle of the bending-molded material, calculates a correction value of the angle adjustment unit based on a deviation between the detected bending angle and the target angle, and operates the motor according to the calculated correction value. And controlling the amount of movement of the guide block.

As described above, according to the present invention, it is possible to implement bending molding capable of correcting the spring back regardless of the physical properties of the material without requiring separate measures by the operator, and while securing the shape freeze of the final product, a continuous process You will get the effect that can promote the automation.

1 is a front view showing a bending molding apparatus according to an embodiment of the present invention.
2 is an operation state diagram of FIG. 1.
3 is a view showing a state in which a material is input to the bending molding apparatus according to an embodiment of the present invention.
4 and 5 are views schematically showing a process in which the bending angle is controlled in the bending molding apparatus according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 is a front view showing a bending molding apparatus according to an embodiment of the present invention, Figure 2 is an operating state diagram of FIG.

As shown in these drawings, a bending molding apparatus according to an embodiment of the present invention includes a die 10 fixed to support a material to be bent and molded; At least one pivoting punch 20 capable of rotating the material 1 at a predetermined angle by relative movement with respect to the die, and rotating so that the angle with respect to the die is variable; And an angle adjusting unit 30 installed adjacent to the die to adjust the angle of the rotating punch when the rotating punch presses against the material.

For convenience, a case where the bending molding apparatus according to an embodiment of the present invention is applied to a press and disposed vertically will be described as an example. However, the present invention is not limited thereto, and the principle of the present invention is not completely excluded even when the device is configured in a horizontal arrangement (when a rotating punch presses an upright material in a horizontal direction by a separate driving means). Reveal it.

The die 10 is formed so as to be capable of bending a material 1 such as a plate material, and is fixedly supported on the press base 11. This die is preferably formed to be at least slightly inclined toward the inside of the die with respect to the vertical plane as the top portion goes down.

At least one rotation punch 20 may be installed under the punch holder 21 mounted on the bottom surface of the press ram 12, which provides a pressing force (vertical load) while being moved up and down by a driving force. These pivoting punches are rotated at a predetermined angle when the press ram descends together with the punch holder, so that the material 1 placed on the die 10 can be bent formed.

In the position corresponding to the die 10 in the press ram 12 (usually in the center of the press ram), the press ram 12 comes into contact with the material 1 when the press ram 12 descends together with the rotation punch 20 and the punch holder 21 Thus, a blank holder 22 that presses the material with a constant pressure may be installed. An elastic member such as a gas spring or the like may be adopted as such a blank holder.

For the rotation of the rotation punch 20, the bending molding apparatus according to an embodiment of the present invention further includes at least one hinge part 40 provided in the punch holder 21 to support the rotation punch in a rotatable manner. Can be included. When the pivot punch is provided in pairs, the hinge portions of the pair are disposed to face each other.

The hinge part 40 includes a hinge bracket 41 fixed to the bottom of the punch holder 21 and positioned laterally away from the blank holder 22, and a hinge shaft 42 disposed horizontally on the hinge bracket. Can include.

On the other hand, the pivoting punch 20 may be provided with a hinge groove 24 in which the hinge shaft 42 can be inserted from the upper side thereof toward the inside thereof. In addition, a cam surface 26 or an inclined surface extending from the lower surface of the other side to the bottom surface may be formed in the rotary punch.

Here, the hinge groove 24 may have an insertion depth larger than the diameter of the hinge shaft 42 and may be formed such that there is a clearance through which the hinge shaft can move within the hinge groove.

It is configured in this way, in a state in which the hinge shaft 42 of the hinge portion 40 is inserted into the hinge groove 24 of the rotating punch 20, by the operation of the angle adjustment portion 30 described in more detail below. When a force is applied to or released from the cam surface 26 or the inclined surface of the rotating punch, the rotating punch can rotate at a predetermined angle with respect to the hinge shaft 42 and move toward the hinge bracket 41 or away from the hinge bracket. .

When the rotation punch 20 moves toward or away from the hinge bracket 41, the hinge shaft 42 of the hinge portion 40 is guided within the hinge groove 24 of the rotation punch and moves relative to each other.

In addition, the bending molding apparatus according to an embodiment of the present invention is interposed between a pair of rotation punches 20 when the rotation punches 20 are provided in pairs, and when the press ram 12 rises, a pair It may include at least one return member 50 to return each of the rotation punch to its original position.

The return member 50 is preferably an elastic member such as a coil spring, but is not limited thereto. When the return member is a coil spring, each end of the coil spring is fitted in the mounting groove 25 formed between the hinge groove 24 and the bottom surface on one side of the rotation punch 20, thereby forming a pair of rotation punches and Assembly between the return members can be made.

In addition, the bending molding apparatus according to an embodiment of the present invention is fixed to the bottom of the punch holder 21 to be spaced apart from the hinge portion 40, further comprising a stopper 60 to limit the movement of the pivoting punch 20 Can include.

Thereby, when each rotation punch 20 is rotated at a predetermined angle with respect to the hinge shaft 42 and its upper part moves away from the hinge bracket 41, it meets the stopper 60 and its movement is prevented. Accordingly, the hinge shaft is prevented from completely coming out of the hinge groove 24, so that the pivoting punch is not removed from the hinge portion 40.

The angle adjustment unit 30 includes a motor 32 installed on the support 31 positioned adjacent to the die 10; A transfer screw 33 installed on the support and rotated by a motor; A movable nut 34 that is screwed to the transfer screw and moved according to the rotation of the transfer screw; And a guide block 35 that is mounted on the movable nut and moves according to the movement of the movable nut, and guides the movement of the rotation punch while in contact with the rotation punch 20.

The motor 32 can rotate in a forward or reverse direction by controlling its operation by the control unit 70 to control the amount of movement of the movable nut 34 and the guide block 35 mounted thereon. In addition, when the position adjustment of the guide block is completed, the motor may fix the guide block so that the guide block cannot be moved.

In this way, the angle adjustment unit 30 moves the guide block 35 horizontally to change the distance between the guide block and the die 10, thereby facilitating the angle at which the rotation punch 20 rotates, that is, the bending angle. You can adjust it.

In addition, the angle adjustment unit 30 further includes an elevating unit 36 for elevating the support unit 31, and its height may be adjusted. As such an elevating part, for example, a fluid pressure cylinder with an actuating rod may be employed, and the actuating rod may be connected to the support part 31 by being installed on the press base 11.

Additionally, in the bending molding apparatus according to an embodiment of the present invention, a bending angle measuring unit 80 for detecting a bending angle of a material may be disposed around the die 10. As the bending angle measurement unit, for example, a camera for photographing the material 1 may be used.

The bending angle measurement unit 80 is not limited to the above-described camera, and at least one of any other optical displacement sensor, a non-contact displacement sensor such as a capacitive type, a differential transformer type, a magnetic type, or a contact type displacement sensor It may be employed as a measurement unit.

The position of the bending angle measurement unit 80 may be determined to be an appropriate place inside or outside the press so that interference does not occur in bending molding.

The control unit 70 may be connected to the bending angle measurement unit 80, and may calculate the bending angle of the material 1 by processing an image captured by a camera, for example. In FIGS. 1 and 2, for convenience, a plurality of controllers are shown, but it is obvious that they may be configured as a single controller.

On the other hand, if the bending angle measurement unit 80, the control unit 70, the angle adjustment unit 30, the elevating unit 36, etc. are arranged independently for each part where bending is formed in the material (1), the material is formed into an asymmetric shape. It is possible to do.

Hereinafter, the operation of the bending molding apparatus according to an embodiment of the present invention will be described.

3 is a view showing a state in which a material is input to a bending molding apparatus according to an embodiment of the present invention, and FIGS. 4 and 5 are a process of controlling a bending angle in a bending molding apparatus according to an embodiment of the present invention. These are drawings schematically showing.

First, the material 1 may be formed in advance to have a plurality of blanks 2 at least partially cut off as shown in FIG. 3 for continuous bending molding. Each blank can be bent formed into a symmetrical or asymmetrical shape by the bending molding apparatus according to an embodiment of the present invention.

The height of the angle adjustment unit 30 may be adjusted by the lifting unit 36, and when the angle adjustment units are disposed on both sides of the die 10, these angle adjustment units may have the same or different heights.

Initially, the guide block 35 of the angle adjustment part 30 is located sufficiently far from the die 10.

A blank 2 to be molded of the material 1 is placed on the die 10.

As the press ram 12 descends, the punch holder 21 and a pair of rotation punches 20 mounted on the bottom thereof also descend. In addition, the blank holder 22 also descends together to contact the blank 2 of the material 1 and fixes the blank to the die 10 with a constant pressure.

When the press ram 12 descends together with the punch holder 21, the rotation punch 20 comes into contact with the guide block 35 of the angle adjustment unit 30 to guide its downward movement.

During the stroke distance of the press ram 12, bending molding is made by pressing the blank 2 of the material 1 supported by the fixed die 10 toward the die. At this time, the angle of the rotary punch with respect to the horizontal plane is almost a right angle as shown in FIG.

The press ram 12 that has reached the bottom dead center rises and returns to its original position.

In the bending-molded blank 2, a spring-back phenomenon occurs due to the interaction of tensile and compressive residual stresses in the thickness direction, which is more frequent when the blank is a high-strength material.

The generated spring back of the blank 2 is measured by the bending angle measurement unit 80. For example, by detecting the bending angle using a bending angle measuring unit made of a camera, the amount of springback generated relative to the desired shape is measured.

The control unit 70 calculates the deviation between the detected bending angle and the target angle, calculates a correction value of the angle adjustment unit 30 based on the result, and controls the operation of the motor 32 according to the calculated correction value. Ultimately, the amount of movement of the guide block 35 is controlled.

As the transfer screw 33 is driven by the motor 32, the movable nut 34 moves, and the guide block 35 is moved toward the die 10 as shown in FIG. 5, thereby changing the distance between the guide block and the die.

As a result, the measured spring back affects the adjustment of the rotation angle of the rotation punch 20 through the guide block 35 of the angle adjustment unit 30, and can be reflected in the bending molding of the next blank (2). There will be.

The material 1 is moved so that the next blank 2 to be formed is placed on the die 10.

As the press ram 12 descends, the punch holder 21 and a pair of rotation punches 20 mounted on the bottom thereof also descend.

In this case, when the press ram 12 descends together with the punch holder 21, the lower cam surface 26 or the inclined surface comes into contact with the guide block 35 of the angle adjustment unit 30 to receive a force, and the hinge part Since it is rotatably supported by 40, the entire rotation punch 20 is rotated at a predetermined angle and moves laterally toward the die 10.

Here, since the rotation punch 20 is rotated with the portion in contact with the edge of the die 10 as a rotation center, the upper part of the rotation punch moves away from the hinge bracket 41 in the opposite direction to the lower part, and the hinge part ( The hinge shaft 42 of 40) moves relative to the hinge groove 24 of the pivoting punch. The upper part of the rotation punch meets the stopper 60 and its movement may be prevented.

During the stroke distance of the press ram 12, the next blank 2 of the material 1 supported by the fixed die 10 is moved while being rotated by the guide block 35 of the angle adjusting unit 30. By pressing the rotary punch 20 toward the die more than the previous blank, excessive bending molding is achieved than the previous blank. At this time, the angle with respect to the horizontal plane of the rotary punch has an acute angle of approximately 85 degrees, for example, as shown in FIG. 5.

Thereafter, the press ram 12, which has reached the bottom dead center, rises and returns to its original position.

As the press ram 12 rises, the punch holder 21 and a pair of rotation punches 20 mounted on the bottom thereof also rise.

The pair of rotation punches 20 move in a direction away from each other by the elastic force of the return member 50. Further, when the force applied by the guide block 35 is released, the rotation punch rotates in the reverse direction.

The bending angle measurement unit 80 measures the spring back of the bent-formed blank 2, and the control unit 70 calculates a correction value of the angle adjustment unit 30 based on the detected deviation between the bending angle and the target angle, The movement amount of the guide block 35 is finely adjusted according to the calculated correction value.

The process of fine-adjusting the guide block 35 of the angle adjusting unit 30 until the desired bending angle is measured by the bending angle measuring unit 80 and then bending the next blank 2 with a rotation punch 20 is repeated. do. The blank sacrificed to extract the bending molding conditions becomes a defective product, but compared to the cost of modifying the mold according to the variation in physical properties, the cost of the defective product is very low.

When the desired bending angle is measured, bending molding is continuously performed without adjustment of the angle adjustment unit 30 from a new blank thereafter.

Even after the bending molding conditions, that is, the bending angle, are determined, the spring back of the blank can be continuously measured, and accordingly, shape freezeability can be maintained even in the case of variations in physical properties within or between materials.

When the bending molding for all the blanks 2 of the material 1 is completed, a new material is introduced, and the guide block 35 of the angle adjustment unit 30 is moved to the initial position located sufficiently far from the die 10. Return and start over from the beginning of the process described above from the first blank of new material.

As described above, in the bending molding apparatus according to an embodiment of the present invention, the measurement and correction of the spring back may be performed by bending several times. In particular, during the process of extracting the bending molding conditions, no separate measures are required by the operator, and even if a material of other physical properties is input, it can be corrected and reflected in production during continuous bending regardless of the physical properties of the material. There is an advantage that does not hinder.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

1: material 2: blank
10: die 20: rotating punch
30: angle adjustment unit 36: elevating unit
40: hinge part 50: return member
60: stopper 70: control unit
80: bending angle measurement unit

Claims (14)

Fixed die;
At least one pivoting punch capable of bending the material at a predetermined angle by relative movement with respect to the die and rotatable so that the angle with respect to the die is variable;
An angle adjusting unit installed spaced apart from the die and configured to adjust an angle of the pivoting punch when the pivoting punch presses against the material; And
A bending angle measuring unit disposed away from the die to detect the bending angle of the material
Including,
The angle adjustment unit,
A motor installed on a support part spaced from the die;
A transfer screw installed on the support and rotated by the motor;
A movable nut screwed to the transfer screw and moved according to the rotation of the transfer screw; And
A guide block mounted on the movable nut, moving according to the movement of the movable nut, and guiding the movement of the rotating punch while in contact with the rotating punch
Including,
Further comprising a control unit connected to the bending angle measurement unit and the motor,
The control unit calculates the bending angle of the bend-molded material, calculates a correction value of the angle adjustment unit based on the deviation between the detected bending angle and the target angle, and controls the operation of the motor according to the calculated correction value. A bending molding device that adjusts the amount of movement of the guide block.
The method of claim 1,
The rotating punch is installed on a punch holder mounted on a press ram providing a pressing force,
The bending molding apparatus further comprises at least one hinge portion provided in the punch holder and rotatably supporting the rotation punch.
The method of claim 2,
The hinge portion, a bending molding apparatus comprising a hinge bracket fixed to the punch holder and a hinge shaft disposed on the hinge bracket.
The method of claim 3,
The pivoting punch is provided with a hinge groove formed so that the hinge shaft can be inserted from the top of one side toward the inside,
The hinge groove has an insertion depth greater than a diameter of the hinge shaft, and a clearance for the hinge shaft to move exists within the hinge groove.
The method of claim 4,
The rotary punch is a bending molding apparatus, characterized in that the cam surface or inclined surface extending from the bottom of the other side to the bottom surface is formed.
The method of claim 2,
When the rotation punches are provided in pairs, the bending molding apparatus further comprises at least one return member interposed between the pair of rotation punches.
The method of claim 2,
A bending molding apparatus further comprising a stopper fixed to the punch holder to be spaced apart from the hinge portion, and restricting movement of the pivoting punch.
delete The method of claim 1,
The angle adjustment unit further includes an elevating unit for raising and lowering the support unit, and the height is adjusted.
delete delete The method of claim 1,
The bending angle measurement unit bending molding apparatus, characterized in that at least one of a camera, a non-contact displacement sensor, and a contact displacement sensor.
The method according to any one of claims 1 to 7, 9 and 12,
The bend forming apparatus, characterized in that the material has a plurality of blanks that are at least partially cut off for continuous bending forming.
The method of claim 13,
A portion of the plurality of blanks is bent formed by the rotation punch until a desired bending angle is measured, and the bending angle is measured by the bending angle measuring unit and then sacrificed.

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