KR-20260062495-A - Spring back compensation apparatus of seat cross member for vehicle and spring back compensation method thereof

KR20260062495AKR 20260062495 AKR20260062495 AKR 20260062495AKR-20260062495-A

Abstract

The present invention relates to a springback correction device and a correction method for a seat cross member of an automobile, comprising: a lower mold having a seating portion formed thereon on which a seat cross member pre-formed through a press is seated; at least one pair of molding surface processing control portions installed on both sides of the lower mold so as to be movable in a direction close to or farther from the seating portion, wherein the pressure position for pressing the two sides of the seat cross member seated on the seating portion 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 seat cross member seated on the seating portion while simultaneously pressing the molding surface processing control portions in a direction close to the seating portion; and a control unit for controlling the operation of the upper mold and the molding surface processing control portions. The invention further comprises a material characteristic measurement step for measuring the material characteristics of a seat cross member pre-formed through a press, and a molding pressure and molding conditions of a springback correction device for correcting the springback of the seat cross member based on the material characteristics of the seat cross member measured in the material characteristic measurement step. The springback correction method comprises: a first forming error correction step for predicting; a first press forming step for introducing the seat cross member into the springback correction device and performing a first forming of the seat cross 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 the seat cross member formed through the first press forming step; a second forming error correction step for analyzing the shape of the seat cross 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 springback correction device according to the determined amount and type of springback displacement; and a second press forming step for introducing the seat cross member back into the springback correction device and performing a second forming of the seat cross member according to the forming pressure and forming conditions of the springback correction device predicted in the second forming error correction step. According to the present invention as described above, the defect rate of the finally manufactured sheet cross member can be significantly reduced by predicting the forming pressure and forming conditions of a springback correction device based on the material characteristics, springback displacement amount, and type of the sheet cross member formed from an ultra-high-strength steel plate through a press, and correcting the springback displacement amount.

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 sheet cross member pre-formed through a press; At least one pair of molding surface processing control parts 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 pressing both sides of the seat cross member seated on the seating portion, wherein the pressing position for pressing both sides of the seat cross 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 region of the sheet cross member seated on the seating portion and pressing the molding surface processing control portion in a direction close to the seating portion; A spring back correction device for an automobile seat cross member, 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 seat cross member; A driving means installed on one side of the above-mentioned moving plate and connected to one side of the above-mentioned forming cam to move the above-mentioned forming cam in a direction close to or farther from the above-mentioned seating portion to press one side of the side of the above-mentioned seat cross member, and for adjusting the position of the inner end of the above-mentioned forming cam; A spring back correction device for an automobile seat cross member, 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 springback correction device for an automobile seat cross member, further comprising a pressure induction member including a rotating shaft rotatably installed on both opposing inner sides in the width direction of the pressure 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 sheet cross member pre-formed through a press; A first molding error correction step for predicting the molding pressure and molding conditions of a springback correction device to correct the springback of the sheet cross member based on the material characteristics of the sheet cross member measured in the above material characteristic measurement step; A first press forming step of feeding the above-mentioned seat cross member into the above-mentioned springback correction device and first forming the above-mentioned seat cross 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 sheet cross member formed through the above first press forming step; A second molding error correction step for analyzing the shape of the sheet cross member detected in the product shape detection step to determine the amount and type of springback displacement, and predicting the molding pressure and molding conditions of the springback correction device according to the determined amount and type of springback displacement; A method for correcting springback of a seat cross member for an automobile, characterized by including a second press forming step of reintroducing the seat cross member into the springback correction device and secondarily forming the seat cross member according to the forming pressure and forming conditions of the springback correction device predicted in the second forming error correction step.

Description

Spring back compensation apparatus of seat cross member for vehicle and spring back compensation method thereof The present invention relates to a springback correction device and method for a seat cross member for an automobile, and more specifically, to a springback correction device and method for a seat cross member for an automobile that can significantly reduce the defect rate of the finally manufactured seat cross member by predicting the forming pressure and forming conditions of a press forming device based on the material characteristics, springback displacement amount, and type of the seat cross member formed from an ultra-high-strength steel plate through a press, and correcting the springback displacement amount. 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, ultra-high-strength steel plates with a tensile strength of 1.2 GPa to 1.5 GPa are being actively applied to side sill members, seat cross members, front side members, and door impact members, which require structural and crash stability in the vehicle body frame, in order to improve the safety performance and reduce weight of the vehicle. Meanwhile, the seat cross member of the vehicle body frame is a skeletal structure installed on the floor panel and is used to increase the strength and rigidity of the vehicle body frame. It is installed perpendicular to the direction of travel of the vehicle between the side sill members located on both sides of the vehicle body and the center of the floor panel to prevent twisting or bending in the front-rear and left-right directions of the vehicle body, while simultaneously increasing side collision performance and bending rigidity to enhance occupant safety. It is a very important element directly related to safety in the event of an accident. These seat cross members are typically formed using a press, but press forming imposes many limitations on the shape of the product to be formed, the thickness of the material, and the forming process for materials such as ultra-high-strength steel sheets. In other words, when producing a seat cross member 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 causing frequent forming defects. In particular, in the case of conventional press forming devices for forming sheet cross members as described above, there was a problem in that it was not possible to correct for springback even if it occurred after forming the sheet cross member, or to change the forming conditions of the press according to the degree of deformation of the springback. Therefore, there is an urgent need for a device and method capable of compensating for springback even if it occurs after forming the sheet cross 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 an automobile seat cross member formed through a springback correction device according to one embodiment of the present invention. FIG. 2 is a drawing for explaining the springback occurrence area of an automobile seat cross member. FIG. 3 is a schematic diagram for explaining a springback correction 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 springback correction 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 springback correction 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 an automobile seat cross member formed through a springback correction device according to one embodiment of the present invention, and