KR-20260062494-A - Press forming apparatus of side sill member for vehicle and press forming method thereof

KR20260062494AKR 20260062494 AKR20260062494 AKR 20260062494AKR-20260062494-A

Abstract

The present invention relates to a press forming apparatus and a forming method for a side sill member for an automobile, comprising: a lower mold having a seating portion formed thereon on which a side sill member pre-formed through a press is seated; at least one pair of forming surface processing control units installed on both sides of the lower mold so as to be movable in a direction close to or apart from the seating portion, and which press both sides of the side sill member seated on the seating portion, wherein the pressing position of pressing both sides of the side sill member is variable; an upper mold installed on the upper part of the lower mold so as to be movable vertically, which presses the central area of the side sill member seated on the seating portion while simultaneously pressing the forming surface processing control units in a direction close to the seating portion; and a control unit for controlling the operation of the upper mold and the forming surface processing control units; a material characteristic measurement step for measuring the material characteristics of a side sill member pre-formed through a press; and a first step for predicting the forming pressure and forming conditions of a press forming apparatus to form the side sill member based on the material characteristics of the side sill member measured in the material characteristic measurement step. The press forming method comprises a forming error correction step, a first press forming step in which the side seal member is fed into a press forming device and the side seal member is first formed at the forming pressure and forming conditions predicted in the first forming error correction step, a product shape detection step in which the shape of the side seal member formed through the first press forming step is detected, a second forming error correction step in which the shape of the side seal member detected in the product shape detection step is analyzed to determine the amount and type of springback displacement and the forming pressure and forming conditions of the press forming device according to the determined amount and type of springback displacement, and a second press forming step in which the side seal member is re-fed into the press forming device and the side seal member is secondarily formed according to the forming pressure and forming conditions of the press forming device predicted in the second forming error correction step. According to the present invention as described above, the defect rate of the finally manufactured side sill member can be significantly reduced by predicting the forming pressure and forming conditions of the press forming device based on the material characteristics, springback displacement amount, and type of the side sill member formed from an ultra-high-strength steel plate through a press, and correcting the forming error.

Inventors

이상구
남성우
이정흠
김대인

Assignees

대우공업 (주)

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (4)

A lower mold having a seating portion formed thereon for a side sill member pre-formed through a press; At least one pair of molding surface processing control parts are installed on both sides of the lower mold so as to be movable in a direction close to or apart from the seating portion, and press both sides of the side sill member seated on the seating portion, wherein the pressing position for pressing both sides of the side sill member is variable; An upper mold installed so as to be vertically movable on the upper part of the lower mold, and simultaneously pressing the central area of the side seal member seated on the seating portion and pressing the molding surface processing control portion in a direction close to the seating portion; A press forming device for a side sill member of an automobile, characterized by including a control unit for controlling the operation of the upper mold and the molding surface processing control unit.
In paragraph 1, The molding surface processing control part At least one pair of movable plates installed on both sides of the lower mold so as to be movable in a direction close to or farther from the seating portion; An operating cam having a block shape with open inner and outer sides, fixedly installed on the upper part of the movable plate, and which moves the movable plate in a direction close to the seating portion when one side is pressed by an upper mold; A forming cam that extends from one inner side of the operating cam toward the seating portion, and when the moving plate moves toward the seating portion, the extended inner end presses against one side of the side of the side sill member; A driving means for adjusting the inner end position of the forming cam, which is installed on one side of the moving plate and connected to one side of the forming cam, and which moves the forming cam in a direction close to or farther away from the seating portion to press one side of the side sill member; A press forming apparatus for a side sill member of an automobile, characterized by including an elastic member interposed between the inner end of the movable plate and the outer end of the seating portion, which applies an elastic force to cause the movable plate to return to a direction separated from the seating portion when the pressing force of the upper mold is released.
In paragraph 1, The above forming cam is A plurality of air supply channels are formed at regular intervals along the width direction to spray heated air through an inner end, and an installation space is further formed on one side of the inner end to communicate with the plurality of air supply channels along the width direction, A pressurizing block having a block shape corresponding to the above-mentioned installation space, wherein the upper and lower surfaces are slidably coupled in an inward or outward direction to one side of the inner surface of a corresponding molding cam, and a space is formed inside, wherein a plurality of first outlet holes communicating with the plurality of air supply passages and the space are formed on one side of the outer end, and a plurality of second outlet holes communicating with the space are formed on one side of the inner end; An elastic member having both ends fixedly coupled between the outer end of the pressure block and one side of the inner surface of the molding cam in which the installation space is formed; A press forming device for a side sill member of an automobile, further comprising a pressurizing guide including a rotating shaft rotatably installed on both opposing inner sides in the width direction of the pressurizing block in which the space is formed, arranged along the width direction of the space, a plurality of rotating blades formed as plate-shaped members protruding radially on one side of the outer surface of the rotating shaft corresponding to the plurality of first outlet holes, and a plurality of weight bodies eccentrically coupled to the other side of the outer surface of the rotating shaft arranged between the plurality of rotating blades.
A material property measurement step for measuring the material properties of a side sill member pre-formed through a press; A first forming error correction step for predicting the forming pressure and forming conditions of a press forming device to form the side sill member based on the material characteristics of the side sill member measured in the above material characteristic measurement step; A first press forming step of feeding the side sill member into a press forming device and first forming the side sill member with the forming pressure and forming conditions predicted in the first forming error correction step; A product shape detection step for detecting the shape of a side sill member formed through the above first press forming step; A second forming error correction step for analyzing the shape of the side sill member detected in the product shape detection step to determine the amount and type of springback displacement, and predicting the forming pressure and forming conditions of the press forming device according to the determined amount and type of springback displacement; A press forming method for a side sill member for an automobile, characterized by including a second press forming step of reintroducing the side sill member into the press forming device and secondarily forming the side sill member according to the forming pressure and forming conditions of the press forming device predicted in the second forming error correction step.

Description

Press forming apparatus of side sill member for vehicle and press forming method thereof The present invention relates to a press forming apparatus and a forming method for a side sill member for an automobile, and more specifically, to a press forming apparatus and a forming method for a side sill member for an automobile that can significantly reduce the defect rate of the finally manufactured side sill member by predicting the forming pressure and forming conditions of the press forming apparatus based on the material characteristics, springback displacement amount, and type of the side sill member pre-formed from an ultra-high-strength steel plate through a press, and correcting the forming error. Recently produced automobiles are becoming more intelligent for the convenience of drivers and passengers, and the adoption of convenience features is accelerating. Along with this, the application of safety devices to further enhance passenger safety is also increasing. In this context, the vehicle body frame is the most critical element for ensuring passenger safety, and it is manufactured in various forms and structures. In particular, the application of ultra-high-strength steel plates with a tensile strength of 1.2 GPa to 1.5 GPa is actively being carried out in order to improve the safety performance and reduce weight of automobiles, especially in side sill members, seat cross members, and front side members, where structural and crash stability are required within the vehicle body frame. Meanwhile, the side sill members of the vehicle frame are located on both sides of the vehicle body and function to absorb and transmit impacts occurring in the vehicle body, and in particular, to maintain the safety zone of the driver and passenger seats from such impacts; thus, they are a very important element directly related to safety in the event of an accident. These side sill members are typically formed using a press, but press forming often results in many limitations regarding the shape of the product to be formed, the thickness of the material, and the material, such as ultra-high-strength steel sheets. In other words, when a side sill member is manufactured by press forming an ultra-high-strength steel plate with a tensile strength of 1.2 GPa to 1.5 GPa, excessive spring back occurs, making shape control difficult and frequently resulting in forming defects. In particular, in the case of conventional press forming devices for forming side sill members as described above, there was a problem in that even if springback occurred after forming the side sill member, it was not possible to correct it or change the forming conditions of the press according to the degree of deformation of the springback. Therefore, there is an urgent need for a press forming device and forming method capable of compensating for springback even if it occurs after forming the side sill member, or changing the forming conditions of the press according to the degree of deformation of the springback. FIG. 1 is a perspective view of a side sill member for an automobile formed through a press forming device according to an embodiment of the present invention. FIG. 2 is a drawing for explaining the springback occurrence area of a side sill member for an automobile. FIG. 3 is a schematic diagram for explaining a press forming device according to an embodiment of the present invention, FIG. 4 is a perspective view of a molding surface processing control unit according to one embodiment of the present invention, FIGS. 5a to 5c are drawings for explaining the operation of a press forming device according to an embodiment of the present invention, FIG. 6 is a schematic cross-sectional view of a forming cam according to another embodiment of the present invention, FIG. 7 is a schematic perspective view of a pressure induction unit according to another embodiment of the present invention, FIGS. 8a and 8b are drawings for explaining the operation of a forming cam according to another embodiment of the present invention, FIG. 9 is a flowchart for explaining a press forming method according to an embodiment of the present invention. The present invention will be described in more detail below with reference to the drawings. It should be noted that identical components in the drawings are indicated by the same reference numerals wherever possible. Furthermore, detailed descriptions of known functions and configurations that could unnecessarily obscure the essence of the invention are omitted. FIG. 1 is a perspective view of a side sill member for an automobile formed through a press forming device according to an embodiment of the present invention, and FIG. 2 is a drawing for explaining the springback occurrence area of a side sill member for an automobile. Referring to FIGS. 1 and 2, a side sill member (100) for an automobile, formed through a press forming device according to one embodiment of the present invention, is installed on both sides of a