Ejecting mechanism for an automotive drawing die

Abstract

The present invention discloses an ejection mechanism for an automotive drawing die, which includes a blank holder, a limit insert block, a cylinder, a ejector pin, a connecting column and a pin. A bottom column is provided at the bottom end of the blank holder, the limit insert block is installed at the bottom end of the bottom column, the cylinder is installed at the bottom end of the limit insert block. Through holes communicating with each other are vertically formed at corresponding positions on the blank holder and the bottom column. At the upper and lower ends of the middle part of the limit insert block, a first blind hole and a second blind hole communicating with each other are respectively provided. The first blind hole has the same radius as the through hole and is larger than the radius of the second blind hole. The ejector pin is arranged in the through hole and the first blind hole. A groove is formed at the bottom end of the ejector pin, the connecting column is inserted into the groove, a pin hole is formed at the top of the connecting column, and a kidney-shaped hole communicating with the groove is formed at the bottom of the ejector pin. The pin is inserted into the pin hole and the kidney-shaped hole. The piston rod of the cylinder is connected upward to the connecting column. The present invention is improved aiming at the problem that the existing drawing die is prone to produce drawing marks, and has the advantage of not being prone to produce drawing marks.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive drawing dies, and particularly to an ejection mechanism for an automotive drawing die. Background Art

[0002] Due to the improvement of current automotive production efficiency, it is necessary to improve the production efficiency of automotive body panels to adapt to the design cycle of vehicle models. Manual production of body panels in dies wastes a lot of time in processes such as the placement and positioning of panels and the transfer between front and back processes. Therefore, using automated production will be the mainstream trend for future automotive body panel production, and die design also needs to keep pace with the times to adapt to development.

[0003] Drawing dies play a huge role in the automated production line of automotive body panels. A drawing die generally includes an upper die, a blank holder, and a lower die from top to bottom. Among them, the upper die is generally concave, the lower die is generally convex, the blank holder is an annular part with a hollow in the middle, and the blank holder and the lower die are connected by an elastic buffer. During operation, the panel is placed on the blank holder. First, the upper die moves downward until it cooperates with the blank holder to clamp the panel tightly. Then, the blank holder and the upper die move downward together. Thus, the panel is gradually drawn and formed between the upper die and the lower die. After the drawing and forming, the formed panel needs to be removed from the die. However, the panel will tightly adhere to the blank holder after drawing and forming, making it very difficult to remove. In the design of traditional drawing dies, in order to allow the automated manipulator to pick up the panel, a relief is often designed so that the manipulator can reach the bottom of the panel and pick it up. However, for drawing dies, since the panel flows and forms on the die surface, the requirements for the die surface are very high. The design of the relief will cause draw marks on the panel during the process of flowing and forming, affecting the surface quality of the product. Therefore, it is necessary to design an ejection mechanism that allows the manipulator to have enough space to pick up the panel without affecting the product quality. Among them, a cylinder can meet the ejection requirement. First, when setting the cylinder to eject the material, holes need to be drilled on the die surface so that the ejector pin can move up and down to eject the panel. However, there will be an error of 2 - 3 mm in the stroke of the cylinder. As a result, when the cylinder retracts, there will often be situations of over-retraction and under-retraction. Both over-retraction and under-retraction will cause the height of the die surface to be inconsistent. In the next drawing process, draw marks will also appear on the panel. Therefore, there is an urgent need for an ejection mechanism that can eliminate the return error of the cylinder.

[0004] In view of the above technical problems, the present invention discloses an ejection mechanism for an automotive drawing die. The present invention has the advantages of being able to eliminate the return error of the cylinder, no draw marks will appear when the panel is drawn and formed, and the quality of automotive body panels is improved. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide an ejection mechanism for an automotive drawing die, so as to solve the technical problems in the prior art that draw marks will be generated during the drawing and forming process of sheet metal parts in the drawing die, reducing the quality of automotive body panels. The present invention has the advantages of being able to eliminate the return error of the cylinder, no draw marks will appear during the drawing and forming of sheet metal parts, and improving the quality of automotive body panels.

[0006] The present invention is realized through the following technical solutions: The present invention discloses an ejection mechanism for an automotive drawing die, including a blank holder, a limit insert, a cylinder, a ejector pin, a connecting column and a pin. Bottom columns are arranged at intervals at the bottom end of the blank holder. The limit insert is fixedly installed at the bottom end of the bottom column. A cylinder mounting plate is arranged at the top end of the cylinder, and the cylinder mounting plate is fixedly connected to the bottom end of the limit insert. Through holes communicating with each other are vertically opened at corresponding positions on the blank holder and the bottom column. First blind holes and second blind holes are respectively opened at the upper and lower ends in the middle of the limit insert. The first blind hole communicates with the second blind hole, and the centers of the first blind hole, the second blind hole and the through hole are on the same vertical axis. The radius of the first blind hole is equal to that of the through hole, and the radius of the second blind hole is smaller than that of the first blind hole. The ejector pin is arranged in the through hole and the first blind hole, and the outer wall of the ejector pin fits with the inner wall of the through hole and the inner wall of the first blind hole. The top end of the ejector pin is in the same plane as the top end of the blank holder. A groove is opened at the bottom end of the ejector pin. The top of the connecting column is inserted into the groove. The bottom of the connecting column is located in the second blind hole, and the top of the connecting column can slide up and down in the groove. A pin hole is horizontally opened at the top of the connecting column, and a kidney-shaped hole is horizontally opened at the bottom of the ejector pin. The kidney-shaped hole communicates with the groove. The pin is inserted into the pin hole and the kidney-shaped hole, and the pin is located in the middle of the kidney-shaped hole. An avoidance hole is arranged in the middle of the cylinder mounting plate. The end of the piston rod of the cylinder sequentially passes through the avoidance hole, the second blind hole and is fixedly connected to the bottom end of the connecting column upward.

[0007] Further, in order to facilitate the installation and disassembly between the piston rod of the cylinder and the connecting column, an external thread is arranged at the end of the piston rod of the cylinder, a screw hole is arranged at the bottom end of the connecting column, and an internal thread is arranged in the screw hole. The end of the piston rod of the cylinder is fixedly connected in the screw hole through the external thread and the internal thread.

[0008] Further, in order to facilitate the installation and disassembly between the blank holder and the limit insert and between the limit insert and the cylinder mounting plate, the blank holder and the limit insert are fixedly connected by welding, and the limit insert and the cylinder mounting plate are fixedly connected by bolts.

[0009] Further, in order to well eliminate the error generated after the cylinder returns, the height of the kidney-shaped hole is 7-9 mm.

[0010] The present invention has the following advantages: The present invention limits the ejector pin through the limiting insert block, so that when the ejector pin descends to contact the limiting insert block, it cannot continue to move downward. At this time, the top end of the ejector pin and the top end of the blank holder are located on the same plane. At the same time, a groove is provided at the bottom end of the ejector pin, the top of the connecting column is inserted into the groove, and the top of the connecting column can slide up and down in the groove. A pin hole is transversely provided at the top of the connecting column, and a waist-shaped hole is transversely provided at the bottom of the ejector pin. The waist-shaped hole is communicated with the groove, and the plug pin is inserted into the pin hole and the waist-shaped hole, and the plug pin is located in the middle of the waist-shaped hole. Thus, when the cylinder returns too much, the plug pin will move downward in the waist-shaped hole, and when the cylinder returns less, the plug pin will move upward in the waist-shaped hole, thereby eliminating the error generated after the cylinder returns. Thus, when drawing, the top end of the ejector pin can always be kept on the same plane as the top end of the blank holder, ensuring the flatness of the top surface of the blank holder, so that no drawing marks will be generated during the drawing forming process of the sheet metal, and improving the quality of the automotive panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a sectional view of the present invention;

[0012] Figure 2 is a partial structural sectional view of the blank holder;

[0013] Figure 3 is a sectional view of the limiting insert block;

[0014] Figure 4 is a sectional view of the ejector pin;

[0015] Figure 5 is a sectional view of the connecting column;

[0016] Figure 6 is a sectional view of the cylinder mounting plate.

[0017] In the figure: 1, blank holder; 2, limiting insert block; 21, first blind hole; 22, second blind hole; 3, cylinder; 31, cylinder mounting plate; 32, external thread; 311, relief hole; 4, ejector pin; 41, groove; 42, waist-shaped hole; 5, connecting column; 51, pin hole; 52, screw hole; 521, internal thread; 6, plug pin; 7, bottom column; 8, through hole. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following is a detailed description of the embodiments of the present invention. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments. In the description of the present invention, terms indicating orientation or positional relationships such as "front", "rear", "left", and "right" are only for convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0019] Embodiment 1

[0020] Embodiment 1 discloses an ejection mechanism for an automotive drawing die. As Figure 1 shown, it includes a blank holder 1, a limit insert 2, a cylinder 3, a ejector pin 4, a connecting column 5, and a pin 6. At the bottom end of the blank holder 1, bottom columns 7 are arranged at intervals. The blank holder 1 is annular and matches the shape of the sheet metal to be drawn. In this application, it is not described in detail in the accompanying drawings of the specification. Specifically, there are no less than three bottom columns arranged at intervals at the bottom of the blank holder 1. Thus, the drawn sheet metal can be well ejected upward from the blank holder 1 by the ejection mechanism, facilitating the clamping of the sheet metal by the manipulator. The limit insert 2 is fixedly installed at the bottom end of the bottom column 7. Specifically, the blank holder 1 and the limit insert 2 are fixedly connected by welding. At the top end of the cylinder 3, there is a cylinder mounting plate 31, and the cylinder mounting plate 31 is fixedly connected to the bottom end of the limit insert 2. Specifically, the limit insert 2 and the cylinder mounting plate 31 are fixedly connected by bolts (not marked in the figure); as Figure 1 and Figure 2 shown, through holes 8 are vertically and correspondingly opened on the blank holder 1 and the bottom column 7 and are communicated with each other; as Figure 1 and Figure 3 shown, at the upper and lower ends of the middle part of the limit insert 2, a first blind hole 21 and a second blind hole 22 are respectively opened. The first blind hole 21 is communicated with the second blind hole 22, and the centers of the first blind hole 21, the second blind hole 22, and the through hole 8 are on the same vertical axis. The radius of the first blind hole 21 is equal to that of the through hole 8, and the radius of the second blind hole 22 is smaller than that of the first blind hole 21; as Figure 1 , Figure 2 and Figure 3 shown, the ejector pin 4 is arranged in the through hole 8 and the first blind hole 21, and the outer wall of the ejector pin 4 fits with the inner wall of the through hole 8 and the inner wall of the first blind hole 21. The top end of the ejector pin 4 is on the same plane as the top end of the blank holder 1; as Figure 1 and Figure 4 shown, a groove 41 is opened at the bottom end of the ejector pin 4. The top of the connecting column 5 is inserted into the groove 41. The bottom of the connecting column 5 is located in the second blind hole 22, and the top of the connecting column 5 can slide up and down in the groove 41; as Figure 5 shown, a pin hole 51 is horizontally opened at the top of the connecting column 5;Figure 4 As shown, a waist-shaped hole 42 is horizontally opened at the bottom of the top column 4. The height of the waist-shaped hole 42 is 7-9 mm, and the waist-shaped hole 42 communicates with the groove 41; as Figure 1 , Figure 4 and Figure 5 shown, the bolt 6 is inserted into the pin hole 51 and the waist-shaped hole 42, and the bolt 6 is located in the middle of the waist-shaped hole 42; as Figure 6 shown, an avoidance hole 311 is provided in the middle of the cylinder mounting plate 31; as Figure 1 and Figure 6 shown, the end of the piston rod of the cylinder 3 sequentially passes upward through the avoidance hole 311 and the second blind hole 22 and is fixedly connected to the bottom end of the connecting column 5. Specifically, an external thread 32 is provided at the end of the piston rod of the cylinder 3, a screw hole 52 is provided at the bottom end of the connecting column 5, and an internal thread 521 is provided in the screw hole 52. The end of the piston rod of the cylinder 3 is screwed and fixed in the screw hole 52 through the external thread 32 and the internal thread 521.

[0021] The working process of the present invention is as follows: The drawing die generally includes an upper die (not marked in the figure), a blank holder 1, and a lower die (not marked in the figure) from top to bottom. Among them, the upper die is generally concave, the lower die is generally convex, and the blank holder 1 is an annular part with a hollow in the middle. The blank holder 1 is arranged at the top of the lower die through an elastic buffer (not marked in the figure). During work, first, the sheet metal is placed on the top of the blank holder 1, and then the upper die of the drawing die is controlled to move downward. Thus, the upper die gradually contacts the sheet metal on the blank holder 1 and continues to move downward. As a result, the elastic buffer is compressed and generates an upward pushing force on the blank holder 1, so that the upper die and the blank holder 1 clamp the sheet metal tightly. At this time, continue to control the upper die to move downward. At this time, the elastic buffer continues to be compressed, so that the upper die, the blank holder 1, and the sheet metal move downward together, so that the sheet metal is gradually drawn and formed between the upper die and the lower die. After the sheet metal is drawn and formed, first control the upper die to move upward to leave the lower die and the blank holder 1 in sequence, and then control the piston rod of the cylinder 3 to extend. Thus, the cylinder drives the connecting column 5 to move upward, and further controls the ejector pin 4 to move upward to push the sheet metal away from the blank holder 1. At this time, it is convenient for the manipulator to clamp the sheet metal. When closing the die again, the upper die moves downward to press the ejector pin 4 downward. When the ejector pin 4 is pressed down to contact the limit insert 2, it is limited and cannot continue to move downward. At this time, the top end of the ejector pin 4 and the top end of the blank holder 1 are located on the same plane. The upper die and the blank holder 1 clamp the sheet metal tightly. The error after the cylinder 3 returns is offset by the two ends of the pin 6 sliding up and down in the kidney-shaped hole 42. When the cylinder 3 returns more, the end of the cylinder piston rod is relatively lower than the original position. At this time, the two ends of the pin 6 will be below the middle of the kidney-shaped hole 42. When the cylinder 3 returns less, the end of the piston rod of the cylinder 3 is relatively higher than the original position. At this time, the pin 6 will be above the middle of the kidney-shaped hole 42. Thus, during the process of the upper die and the blank holder 1 continuing to move downward to draw the sheet metal, the top end of the ejector pin 4 always remains on the same plane as the top end of the blank holder 1, so as to ensure that no drawing marks appear during the drawing and forming process of the sheet metal, and improve the quality of the automotive panel.

Claims

1. An ejection mechanism for an automotive drawing die, characterized in that It includes a blank holder, a limit insert block, a cylinder, a top column, a connecting column and a pin. Bottom columns are arranged at intervals at the bottom end of the blank holder. The limit insert block is fixedly installed at the bottom end of the bottom column. A cylinder mounting plate is arranged at the top end of the cylinder, and the cylinder mounting plate is fixedly connected to the bottom end of the limit insert block. Through holes communicating with each other are vertically formed at corresponding positions on the blank holder and the bottom column. First blind holes and second blind holes are respectively formed at the upper and lower ends in the middle of the limit insert block. The first blind hole communicates with the second blind hole, and the centers of the first blind hole, the second blind hole and the through hole are on the same vertical axis. The radius of the first blind hole is equal to that of the through hole, and the radius of the second blind hole is smaller than that of the first blind hole. The top column is arranged in the through hole and the first blind hole, and the outer wall of the top column fits with the inner wall of the through hole and the inner wall of the first blind hole. The top end of the top column and the top end of the blank holder are on the same plane. A groove is formed at the bottom end of the top column. The top of the connecting column is inserted into the groove, the bottom of the connecting column is located in the second blind hole, and the top of the connecting column can slide up and down in the groove. A pin hole is horizontally formed at the top of the connecting column, and a kidney-shaped hole is horizontally formed at the bottom of the top column. The kidney-shaped hole communicates with the groove. The pin is inserted into the pin hole and the kidney-shaped hole, and the pin is located in the middle of the kidney-shaped hole. An avoidance hole is arranged in the middle of the cylinder mounting plate. The end of the piston rod of the cylinder sequentially passes through the avoidance hole, the second blind hole and is fixedly connected to the bottom end of the connecting column upward. An external thread is arranged at the end of the piston rod of the cylinder, a threaded hole is arranged at the bottom end of the connecting column, and an internal thread is arranged in the threaded hole. The end of the piston rod of the cylinder is screwed and fixed in the threaded hole through the external thread and the internal thread. The blank holder and the limit insert block are fixedly connected by welding. The limit insert block and the cylinder mounting plate are fixedly connected by bolts. The height of the kidney-shaped hole is 7-9 mm.

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