Variable mold and press equipment

Abstract

The present invention provides a variable mold capable of changing molding conditions to correct molding errors due to springback of a material, and in one embodiment, the variable mold includes an upper mold portion and a lower mold portion, wherein the upper mold portion includes an upper mold cam, and the lower mold portion includes the lower mold body; a mounting portion connected to the lower mold body and on which a molded object is placed; and a molding portion connected to the lower mold body, disposed on one side of the mounting portion, including a lower mold cam corresponding to the upper mold cam, and moving linearly in a first direction toward the mounting portion by the upper mold cam and the lower mold cam, wherein the molding portion includes the lower mold cam; a base plate to which the lower mold cam is connected and configured to be movable in the first direction; an actuator having a portion fixed on the base plate; and a cam block connected to the actuator, wherein the cam block is connected to a plurality of actuators spaced apart in a second direction different from the first direction, and the actuator has a structure that is extendable and contractible in the first direction.

Description

[Technical Field]

[0001] The present invention relates to a variable die and a press device. [Background technology]

[0002] In the automotive industry, the trend toward higher strength materials has led to an increase in the use of bending techniques. Springback, which is inevitable in bending materials, is a phenomenon that occurs due to a combination of factors, such as the material's elastic modulus and stress distribution in the thickness direction, and it is not easy to accurately predict and correct this.

[0003] In the bending industry, attempts have been made to predict springback and improve the accuracy of product forming, such as by adding forming dies to the production process to compensate for springback based on the physical properties of the specific material.

[0004] However, this method has the drawback of being inefficient because a separate molding die must be prepared depending on the material's physical properties, and also has the drawback of not achieving the desired springback compensation effect.

[0005] In other words, even if the physical properties of the sample used to prepare the molding die are the same as those of the material actually processed, if the processing environment changes, the desired springback correction effect may not be achieved.

[0006] For example, with materials such as high-strength coiled steel sheets, the internal stress before forming may differ from that of the sample due to differences in the winding position and winding tension, etc., which can lead to the problem that the targeted springback correction effect cannot be achieved even if the physical properties are the same. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2010-0002958 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a variable die and press device that can change forming conditions to correct forming errors due to springback of the material. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides the following variable die and press device.

[0010] In one embodiment, the present invention includes an upper mold portion and a lower mold portion, wherein the upper mold portion includes an upper mold cam, and the lower mold portion Below a mold body; a placement section connected to the lower mold body and on which a molded object is placed; and a molding section connected to the lower mold body, arranged on one side of the placement section, including a lower mold cam corresponding to the upper mold cam, and moving linearly in a first direction toward the placement section by the upper mold cam and the lower mold cam; wherein the molding section includes the lower mold cam; a base plate to which the lower mold cam is connected and configured to be movable in the first direction; an actuator a portion of which is fixed on the base plate; and a cam block connected to the actuator; wherein the cam block is connected to a plurality of actuators spaced apart in a second direction different from the first direction, and the actuators have a structure that is extendable and contractible in the first direction.

[0011] In one embodiment, the present invention provides a press device comprising: a press body; a plurality of dies installed in the press body for shaping a material; and a moving unit for moving the material among the plurality of dies, wherein the plurality of dies include a first die for bending a portion of the material and a second die for re-shaping the bent portion of the material shaped by the first die, and the second die is the variable die. [Effects of the Invention]

[0012] With the above-described configuration, the present invention can provide a variable die and a press device that can change the forming conditions to correct forming errors due to springback.

[0013] Furthermore, the present invention can provide a variable die and a press device that can accurately form a single part even when the degree of springback varies depending on the formed shape. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of a die used in a conventional press machine. [Figure 2] 1 is a schematic diagram of a molded product. [Figure 3] 3 is a graph showing measurements of the molded shapes of the molded products A to D in FIG. 2. [Figure 4] FIG. 1 is a conceptual diagram of a variable mold according to an embodiment of the present invention. [Figure 5] FIG. 2 is a schematic front view of a variable mold according to an embodiment of the present invention. [Figure 6] FIG. 6 is a schematic plan view of the variable mold of the embodiment of FIG. 5. [Figure 7a] 7A to 7C are enlarged views of the cam block portion of FIG. 6 in various states. [Figure 7b] 7A to 7C are enlarged views of the cam block portion of FIG. 6 in various states. [Figure 7c] 7A to 7C are enlarged views of the cam block portion of FIG. 6 in various states. [Figure 8] 6 is a schematic view showing how the variable mold according to the embodiment of FIG. 5 molds a workpiece. [Figure 9] 1 is a graph showing the measurement results of the molded shape of a molded product molded using a variable mold of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the present invention. However, in describing preferred embodiments of the present invention in detail, if it is determined that a detailed description of related well-known functions or configurations may unnecessarily obscure the gist of the present invention, such detailed description will be omitted. Furthermore, the same reference numerals will be used throughout the drawings for parts having similar functions and operations. In this specification, terms such as "top," "upper," "upper surface," "bottom," "lower," "bottom surface," "side," etc. are used based on the drawings and may actually differ depending on the direction in which elements or components are arranged.

[0016] Furthermore, throughout the specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" through another element therebetween. Furthermore, unless otherwise specified, "comprising" a certain component does not mean excluding other components, but may further include other components.

[0017] FIG. 1 shows a schematic diagram of a die used in a conventional press machine.

[0018] As shown in Fig. 1, the mold 1 used in the press device includes an upper mold section 10 and a lower mold section 20. The upper mold section 10 is connected to a movable section that moves up and down of a press body provided in the press device, and moves up and down in accordance with the movement of the movable section, while the lower mold section 20 is connected to a fixed section of the press body. Although not shown, the press device positions the object P to be molded between the upper mold section 10 and the lower mold section 20, and may include a moving unit that pulls out a molded product formed by the mold 1 from the object P, or an operator may be able to move the object P or the molded product.

[0019] The press device can be fitted with multiple dies to perform multiple moldings simultaneously. When molding is performed using a cam such as that shown in FIG. 1, the cam block 28 moves in a first direction, i.e., horizontally, to mold the molded object P. Therefore, before molding using the die of FIG. 1, the molded object P can be pre-molded using another die to bend a portion of the molded object P, and then molded accurately using the die of FIG. 1.

[0020] In the specification of the present invention, the X direction in Figure 1 can be referred to as the width direction, left-right direction, or movement direction of the cam block 26 of the molding workpiece P, or the first direction; the Y direction can be referred to as the length direction, movement direction, or second direction of the molding workpiece P; and the Z direction can be referred to as the height direction, up-down direction, or third direction of the molding workpiece P.

[0021] The mold 1 in Fig. 1 includes an upper mold section 10 and a lower mold section 20. The upper mold section 10 includes an upper cam 11, a pressure plate 15 for fixing the position of the workpiece P during molding, and a spring 16 for elastically supporting the pressure plate 15. The upper cam 11 has an inclined surface formed so as to convert the vertical movement of the movable part of the press body into movement in a first direction (X direction in Fig. 1) toward the workpiece P. The lower mold section 20 includes a placement section 21 on which the workpiece P is placed, a lower cam 25 with an inclined surface formed to correspond to the upper cam 11, a slide structure 24 that allows the lower cam 25 to move in the first direction, and a cam block 28 that is connected to the lower cam 25 and forms the workpiece P.

[0022] In the case of such a die 1, the workpiece P is formed into a single shape, but the high-strength steel materials that are currently being used, particularly steel materials with tensile strengths of giga-level or higher, have variations in the physical properties of the material due to manufacturing characteristics. When forming using a die 1 with a single shape, the degree of springback varies depending on the variations in the material, causing variations in the shape after forming and leading to product defects. Therefore, the present invention provides a variable die that can change the formed shape based on the physical properties of each steel material.

[0023] Meanwhile, Figure 2 shows a schematic diagram of a formed product, and Figure 3 is a graph showing measurements of the formed shape at positions A to D of the formed product in Figure 2. As shown in Figure 2, when the radii of curvature r1 and r2 of the formed product change along the length of the product, i.e., along the direction of product movement toward the front where the product appears U-shaped (the Y direction in Figure 1), the degree of springback can vary even for the same material. Points A, B, C, and D in Figure 2 are four points at the same height on the formed product, but at different positions left and right (X direction) and front and back (Y direction), and the distances from the reference position at these points are shown in Figure 3. The run number indicates the order in which the product was produced, with one product being formed in each run. The formed shape does not change depending on the run number.

[0024] As shown in Figure 3, it can be seen that the distance from the reference position varies depending on the position in a product formed at one time, and that this tendency is maintained even when the number of times is changed. That is, it can be seen that at positions where additional springback occurs, additional springback continues to occur, and at those positions, it can be seen that springback occurs differently when the radius of curvature of the formed product is different, i.e., distortion occurs in the formed product. Therefore, in order to form an accurate shape even with different springbacks, it is necessary to adjust the forming in the movement direction of the product (Y direction). The present invention provides a variable mold that can adjust the forming, i.e., adjust distortion, in the movement direction of the product.

[0025] FIG. 4 shows a conceptual diagram of a variable mold according to one embodiment of the present invention.

[0026] 4, the variable mold 1 includes an upper mold part 10 and a lower mold part 20, and the upper mold part 10 includes an upper cam 11, a pressure plate 15 for fixing the position of the workpiece P during molding, and a spring 16 for elastically supporting the pressure plate 15. The upper cam 11 has an inclined surface formed so as to convert the vertical movement of the movable part of the press body into movement in a first direction (X direction) toward the workpiece P.

[0027] The lower mold section 20 includes a placement section 21 on which the workpiece P is placed, a lower cam 25 having an inclined surface formed to correspond to the upper cam 11, a slide structure 24 that allows the lower cam 25 to move in a first direction, and a cam block 28 that is connected to the lower cam 25 and forms the workpiece P. In the embodiment of Fig. 4, actuators A1 and A2 that adjust the length in the X direction are disposed at different positions in the Y direction of the cam block 28. That is, the cam block 28 can be adjusted to rotate about the vertical direction (Z direction) by adjusting the lengths of the actuators A1 and A2, which allows the cam block 28 to be adjusted to accommodate variations in the material of the workpiece P or springback that occurs differently in a single workpiece P depending on the molding process.

[0028] In this embodiment, the position of the cam block 28 is adjusted along two axes, and such position adjustment can adjust not only the overall position of the cam block 28 (position in the X direction), but also the rotation of the cam block 28 (rotation around the Z axis), and can also adjust distortions that may occur in the molded product.

[0029] A variable mold according to another embodiment of the present invention is disclosed in Figures 5 and 6. Figure 5 shows a schematic front view of a variable mold 1 according to one embodiment of the present invention, and Figure 6 shows a schematic plan view of the variable mold 1 according to one embodiment of the present invention.

[0030] 5 and 6, the variable mold 1 includes an upper mold part 10 and a lower mold part 20, and the upper mold part 10 includes an upper cam 11, a pressure plate 15 for fixing the position of the workpiece P during molding, and a spring 16 for elastically supporting the pressure plate 15. The upper cam 11 has an inclined surface formed so as to convert the vertical movement of the movable part of the press body into movement in a first direction (X direction) toward the workpiece P.

[0031] The lower mold section 20 includes a lower mold body 22 that is connected to the press body; a placement section 21 that is connected to the lower mold body 22 and on which the molded object P is placed; and a molding section that is connected to the lower mold body 22, is arranged on both sides of the placement section 21, includes lower mold cams 25 that correspond to the upper mold cam 11, and moves linearly in a first direction toward the placement section 21 by the upper mold cam 11 and the lower mold cam 25.

[0032] The molding unit includes the lower cam 25; a base plate 23 to which the lower cam 25 is connected and configured to be movable in the first direction; actuators 26, 27 partially fixed on the base plate 23; and a cam block 28 connected to the actuators 26, 27; and the cam block 28 is connected to a first actuator 26 and a second actuator spaced apart in a second direction different from the first direction, and the actuators 26, 27 have a structure that is extendable and contractible in the first direction.

[0033] The lower cam 25 includes a cam structure 25a and a connecting portion 25b connected to the lower portion of the cam structure 25a, having a hollow structure to form a space in which the actuators 26 and 27 are disposed, and connected to the base plate 23. The base plate 23 is connected to the lower body 22 via a first LM guide G1, and the first LM guide G1 includes a rail extending in the first direction and a guide portion 23a that moves on the rail so that the lower cam 25 can be moved in the first direction by the upper cam 11. The base plate 23 moves the entire structure connected to the base plate 23 along the first direction.

[0034] The first and second actuators 26 and 27 are connected to the base plate 23. Outer portions of the first and second actuators 26 and 27 are fixed to the base plate 23. Here, the outer portions refer to portions located relatively apart from the molding workpiece P so that the cam block 28 can be moved in the X direction by the actuators 26 and 27. The first and second actuators 26 and 27 are located in the hollow portion of the connecting portion 25b.

[0035] The first actuator 26 includes a motor 26a fixed to the base plate 23, a screw 26b connected to the rotation shaft of the motor 26a and rotatable by the motor unit 26a, a moving block 26c having a thread formed on the inside thereof corresponding to the screw 26b, a support unit 26d rotatably supporting an end of the screw 26b that passes through the moving block 26c, a connecting member 26e connecting the moving block 26c and the cam block 28, a pin 26f connected to a connecting hole 28b of the cam block 28 in the connecting member 26a, and a protrusion 26g formed and protruding from the moving block 26c. In the first actuator, the motor 26a can be called a driving unit because it provides power, the screw 26b and the moving block 26c can be called an expandable unit because they move in a first direction, and the connecting member 26e can be called a connecting unit because it is connected to the cam block 28.

[0036] The moving block 26c is connected to the base plate 23 so as to be movable in a first direction. That is, the moving block 26c is connected to the base plate 23 via a second LM guide G2, and the protrusion 26g may be connected to the second LM guide G2.

[0037] Similar to the first actuator 26, the second actuator 27 includes a motor 27a fixed to the base plate 23, a screw 27b connected to the rotating shaft of the motor 27a and capable of being rotated by the motor 27a, a moving block 27c having a thread formed on the inside corresponding to the screw 27b, a support portion 27d for rotatably supporting the end of the screw 27b that has passed through the moving block 27c, a connecting member 27e connecting the moving block 27c and the cam block 28, a pin 27f connected to the connecting hole 28a of the cam block 28 in the connecting member 27a, and a protrusion 27g formed to protrude from the moving block 27c.

[0038] An external power source is connected to the motors 26a, 27a of the first and second actuators 26, 27, and a control unit (not shown) is connected to the motors 26a, 27a. By driving the motors 26a, 27a, the moving blocks 26c, 27c can be moved forward or backward along the first direction. When the moving blocks 26c, 27c move forward, the cam block 28 connected to the first and second actuators 26, 27 moves forward. The first and second actuators 26, 27 can move independently, and the cam block 28 can move forward / backward / rotate as the first and second actuators 26, 27 move independently.

[0039] Meanwhile, a distance measuring sensor 29 for measuring the moving distance of the actuators 26, 27 may be disposed on a side of the first and second actuators 26, 27. The distance measuring sensor 29 may include a laser sensor 29a that irradiates a laser toward the protrusions 26g, 27b and then detects the reflected laser. The laser sensor 29a is fixed to the base plate 23 and measures the distance between the protrusions 26g, 27g protruding from the moving blocks 26c, 27c, thereby measuring the moving distance of the cam block 28 by the first and second actuators 26, 27. The distance measuring sensor 29 is connected to the control unit and can confirm whether the motors 26a, 27a are accurately controlled.

[0040] The configuration in which the cam block 28 is connected to the first and second actuators 26, 27 will be described with reference to Fig. 7a. Figs. 7a to 7c are enlarged views of the cam block portion of Fig. 6 in each state, and Fig. 8 is a schematic view of how the variable mold according to the embodiment of Fig. 5 molds a molded product.

[0041] 7a, the first and second actuators 26, 27 include pins 26f, 27f connected to ends of connecting members 26e, 27e, and the pins 26f, 27f are inserted into first and second connecting holes 28a, 28b of the cam block 28 to connect the first and second actuators 26, 27 to the cam block 28. One of the first connecting hole 28a and the second connecting hole 28b is formed longer than the diameter of the pins 26f, 27f in a second direction, more precisely, in a direction parallel to the pressing surface 28c of the cam block 28, so that the cam block 28 can rotate around the Z direction.

[0042] The pins 26f, 27f of the first and second actuators 26, 27 are formed with circular cross sections to allow the cam block 28 to rotate. One of the first and second connecting holes 28a, 28b (the first connecting hole in this embodiment) is formed as a circular hole having an inner diameter corresponding to the pin 27f, so that in this embodiment, the first connecting hole 28a and the pin 27f of the second actuator 27 are connected so as to allow only rotation. Meanwhile, the other of the first and second connecting holes 28a, 28b (the second connecting hole in this embodiment) includes a pair of semicircular portions having an inner diameter corresponding to the pin 26f and a linear portion between the semicircular portions. The linear portion of the second connecting hole 28b extends in the second direction, i.e., a direction parallel to the pressure surface 28c, so that the length L of the second connecting hole 28b in the second direction is longer than the length D in the first direction. Such a shape of the second connecting hole 28b allows the circular pin 26f to move from the second connecting hole 28b, and the positions of the pins 26f, 27f of the first and second actuators 26, 27 are changed, thereby rotating the cam block 28.

[0043] Fig. 7a shows a state when the first and second actuators 26, 27 are located in the home position, and Fig. 7b shows a state in which the cam block 28 rotates when only the first actuator 26 advances toward the mounting portion 21, i.e., advances in the first direction. Fig. 7c shows a state in which the first and second actuators 26, 27 advance together, and the second actuator 27 advances further than the first actuator. Both the first and second actuators 26, 27 advance, and the cam block 28 as a whole advances from the home position, and the second actuator 27 advances further, causing the cam block 28 to rotate in the opposite direction to Fig. 7b.

[0044] 8 shows a state in which the molding units are arranged on both sides of the molding target P. First and second actuators 26, 27 are arranged on both sides of the molding target P, respectively, and adjust cam blocks 28 that mold the molding target P on both sides of the molding target P. The positions of the first and second connecting holes 28a, 28b in the cam blocks 28 arranged on both sides may be arranged line-symmetrically with respect to the molding target P, or, as shown in FIG. 8, the connecting holes 28a that are only capable of rotation may be arranged diagonally to each other.

[0045] 9 shows a graph measuring the formed shape of a formed product formed using the variable die 1 of the present invention. Initially, the degree of springback varied depending on the position, as in the graph of FIG. 3, but by moving and rotating the cam block 28 through the variable die 1 to form again, and then measuring the springback at each position again, the cam block 28 is moved and rotated to form, so that the desired shape can be quickly reached, and the desired shape can be accurately formed despite the difference in the amount of springback at each position.

[0046] As described above, the present invention has been described mainly with reference to the embodiment, but it goes without saying that the present invention is not limited to this and can be implemented in various modified forms. [Explanation of symbols]

[0047] 1: Variable mold 10: Upper mold part 11: Upper cam 20: Lower mold part 21: Placement section 22: Lower die body 23: Base plate 24: Slide structure 25: Lower cam 26: First actuator 27: Second actuator 26a, 27a: Motor 26b, 27b: Screw 26c, 27c: Moving blocks 26d, 27d: Support part 26e, 27e: connecting members 26f, 27f: pin 28: Cam Block 28a, 28b: First and second connecting holes

Claims

1. A variable mold, It includes an upper mold section and a lower mold section, the upper die portion includes an upper die cam; The lower mold portion is A lower die body, a placement portion connected to the lower mold body and on which a molding object is placed; a forming unit connected to the lower mold body, disposed on one side of the placement unit, including a lower mold cam corresponding to the upper mold cam, and linearly moving in a first direction toward the placement unit by the upper mold cam and the lower mold cam; Including, The molding portion is The lower die cam; a base plate to which the lower die cam is connected and configured to be movable in the first direction; an actuator having a portion fixed on the base plate; a cam block connected to the actuator; Including, A plurality of actuators are connected to the cam block and spaced apart in a second direction different from the first direction, The actuator includes a structure that is extendable and contractible in the first direction.

2. the actuator includes a driving unit fixed to the base plate, an extension / contraction unit connected to the driving unit, and a connecting unit connecting the extension / contraction unit and the cam block, The variable mold according to claim 1 , wherein the distance of the extendable portion in the first direction is adjusted by the driving portion.

3. The variable mold according to claim 2 , further comprising a distance sensor connected to the base plate for measuring the position of the extension or connection portion.

4. the actuators include a first actuator and a second actuator disposed spaced apart from the first actuator in the second direction; the second direction is a direction perpendicular to the first direction in a horizontal plane including the first direction, the first actuator is connected to a first connecting hole formed in the cam block by a pin; the second actuator is connected to a second connecting hole formed in the cam block by a pin; The variable mold according to claim 1 , wherein at least one of the first connecting hole and the second connecting hole has a length greater than a diameter of the pin.

5. the first connecting hole has an inner diameter corresponding to the diameter of the pin; The variable mold according to claim 4 , wherein the second connecting hole has a length in the second direction that is greater than a diameter of the pin.

6. The variable mold according to claim 1 , wherein the base plate and the lower mold body are connected via a first LM guide that allows movement only in the first direction.

7. The variable mold according to claim 2 , wherein the base plate and the connecting portion are connected via a second LM guide that allows movement only in the first direction.

8. The actuator is A motor; a screw rotated by the motor; a moving block having a thread formed thereon corresponding to the screw; a connecting member that connects the moving block and the cam block; Including, The variable mold according to claim 1 , wherein the moving block is connected to the base plate via a second LM guide extending in the first direction.

9. The variable mold according to claim 1 , wherein the molding sections are arranged on both sides of the placing section.

10. The actuator is coupled to a control unit; The variable mold according to claim 9, wherein the control unit adjusts the distance of the actuator in the first direction in consideration of a molding result of the molding object after molding.

11. A press device, The press body and A plurality of dies installed in the press body for molding a material; a moving unit that moves the material among the plurality of molds; Including, The plurality of molds include a first mold that bends a part of the material, and a second mold that re-molds the bent part of the material molded by the first mold, 2. A press machine, wherein the second die is a variable die according to claim 1.

12. the actuators include a first actuator and a second actuator disposed spaced apart from the first actuator in the second direction; the second direction is a direction perpendicular to the first direction in a horizontal plane including the first direction, the first actuator is connected to a first connecting hole formed in the cam block by a pin; the second actuator is connected to a second connecting hole formed in the cam block by a pin; The press device according to claim 11, wherein at least one of the first connecting hole and the second connecting hole has a length greater than a diameter of the pin.

13. the first connecting hole has an inner diameter corresponding to the diameter of the pin; The press device according to claim 12, wherein the second connecting hole has a length in the second direction that is greater than a diameter of the pin.

14. The actuator A motor; a screw rotated by the motor; a moving block having a thread formed thereon corresponding to the screw; a connecting member that connects the moving block and the cam block; Including, The press apparatus according to claim 12, wherein the moving block is connected to the base plate via a second LM guide extending in the first direction.

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