A stamping device and stamping method for stamping parts

Abstract

This invention discloses a stamping device and method for stamping parts, relating to the field of stamping technology. It includes a blank holder that slides up and down along the die opening direction. A punch mounted on an upper die is slidably disposed at the middle position of the blank holder. A first reset member is provided between the lower punch and the upper die. A material support plate mounted on a lower die is provided below the blank holder. A screw is fixed to the lower die below the lower punch, and a lower core is connected to the screw via a spiral groove. At least three sets of flanging cutters are provided on the upper end face of the lower core. The flanging cutters are slidably connected to the lower core. A second reset member is provided between the flanging cutters and the lower core. This stamping device and method combine the stretching and flanging processes, allowing for the sharing of a single mold and a single workstation, effectively reducing overall production costs. Furthermore, because the two processes are performed in one mold, there is no need to transfer the workpiece between two workstations, saving production time.

Description

Technical Field

[0001] This invention relates to the field of stamping technology, specifically to a stamping device and stamping method for stamping parts. Background Technology

[0002] Precision aluminum alloy forgings are complex-shaped, high-precision aluminum alloy forgings produced on forging equipment. The production process involves using a hydraulic device to bring the workpiece (e.g., sheet metal) into contact with the die surface and using a stamping method to form the required shape (e.g., grooves or holes on the sheet metal surface). This process requires no cutting or machining and is widely used in the preparation of aluminum alloy sheet metal workpieces.

[0003] In aluminum alloy forming processes, stretching and flanging typically require two sets of dies, performed at two different stations. This is especially true for parts with cylindrical shapes featuring undercuts during stretching, where two sets of dies significantly increase costs. Firstly, it adds another set of dies; secondly, it requires an additional press; and thirdly, transferring the workpiece between the two presses takes time, resulting in low overall efficiency. Furthermore, for thinner aluminum alloy parts, a single, integral flanging operation increases the likelihood of breakage and cracks. Therefore, we propose a stamping device and method for stamping parts. Summary of the Invention

[0004] The purpose of this invention is to provide a stamping device and a stamping method for stamping parts, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a stamping device and stamping method for stamping parts, comprising a blank holder that slides up and down along the die opening direction, a first nitrogen spring provided between the blank holder and the upper die, a punch mounted on the upper die and slidably disposed at the middle position of the blank holder, the punch consisting of an upper punch and a lower punch, the upper punch being cylindrical and sliding with the middle of the drawing depth as the boundary between the upper punch and the lower punch, a second nitrogen spring provided between the upper punch and the upper die, a first reset member provided between the lower punch and the upper die, a support plate mounted on the lower die below the blank holder, a third nitrogen spring connected between the support plate and the lower die, and the support plate being centered on the axis of the lower punch. Divided into two halves, the material support plate closes as it moves downward along the mold opening direction, forming a stretching and flanging cavity. The lower mold is fixed with a screw below the lower punch, and a lower core is connected to the screw through a spiral groove. At least three sets of flanging blades are arranged in a circumferential array around the axis on the upper end face of the lower core. The flanging blades are slidably connected to the lower core. A second reset member is provided between the flanging blades and the lower core. In the initial state, one end of the flanging blade extends beyond the upper end face of the lower core and slides under the contact of the lower punch, causing the workpiece to be flanged. During the contact of the lower punch with the flanging blades, the lower core rotates under the action of the screw, causing the flanging blades to rotate circumferentially. A third reset member is provided between the lower core and the lower mold.

[0006] Preferably, the working surface of the flanging blade is curved, and the working surface is in line contact with the workpiece.

[0007] Preferably, a rolling shaft is rotatably mounted on the flanging cutter block. Multiple sets of rolling shafts are provided, and the contact points between the rolling shafts and the workpiece form an action surface to generate rolling pressure.

[0008] Preferably, the circumferential surface of the rolling shaft is concave towards the axis, and the circumferential edge line corresponding to the cross section through the axis is always in contact with the workpiece at two points.

[0009] Preferably, the circumferential surface of the rolling shaft is convex and spindle-shaped.

[0010] Preferably, a tuning fork-shaped mounting bracket rotates on the flanging cutter block, and the two ends of the rolling shaft are rotatably connected to the mounting bracket. When the flanging cutter block moves in a spiral motion, the rolling shaft changes its tilt angle according to the shape of the workpiece surface.

[0011] Preferably, the screw causes the flanging cutter to rotate at an angle that is at least twice the circumferential angle between two adjacent flanging cutters, and the workpiece completes flanging when the flanging cutter rotates to the middle of its stroke.

[0012] Preferably, the initial contact surface between the flanging blade block and the lower punch is an arc-shaped surface.

[0013] Preferably, a stamping method for a stamping part stamping device includes the following steps:

[0014] S1 is a single stretching process in which the upper and lower punches move synchronously downward relative to the workpiece to stretch the workpiece.

[0015] S2 secondary stretching: after the upper punch fully contacts the workpiece, the lower punch continues to move downward to complete the stretching of the flanged part.

[0016] S3 flanging, flanging includes the following two sub-steps:

[0017] A1 expansion and flanging: the lower punch moves down and drives the flanging blade to slide. During the rotation of the lower core, the flanging blade expands radially outward and rotates circumferentially to form an overall expansion.

[0018] After the A2 mold is expanded, the lower core continues to rotate, driving the flanging cutter block to rotate, thereby fixing the flanging position.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] This invention combines the stretching and flanging processes into one, allowing the use of a single mold and a single workstation, thereby effectively reducing overall production costs. Furthermore, since the two processes are performed in one mold, there is no need to transfer workpieces between the two workstations, saving production time.

[0021] The present invention uses a rolling method for flanging, which can effectively avoid scratches on the surface of the workpiece. Especially for some thin workpieces, the use of rotary rolling can reduce the possibility of workpiece breakage and cracking, and improve the yield rate. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall half-section structure of the present invention;

[0023] Figure 2 This is a schematic diagram of a half-section of the lower core.

[0024] Figure 3 for Figure 2 Enlarged schematic diagram of the structure in area A;

[0025] Figure 4 This is a schematic diagram of a half-section of the flange cutting tool block;

[0026] Figure 5 This is a schematic diagram of the flanging process on the working surface of the flanging cutter block;

[0027] Figure 6 A top view of the trajectory of the flanging blade block;

[0028] Figure 7 This is a schematic diagram of the trajectory of the front view of the flanging cutter block;

[0029] Figure 8 A schematic diagram showing the various states of the lower punch being stretched.

[0030] Figure 9 This is a schematic diagram of one embodiment of a rolling shaft;

[0031] Figure 10 To distinguish the rolling shaft from Figure 9 Another embodiment diagram;

[0032] Figure 11 This is a structural diagram of the mounting bracket.

[0033] In the diagram: 1-Pressure ring; 2-Punch; 21-Upper punch; 22-Lower punch; 3-Material support plate; 4-Screw; 5-Lower core; 51-Spiral groove; 52-Slide groove; 6-Flanging cutter block; 61-Limiting strip; 7-Second reset component; 8-Third reset component; 9-Rolling shaft; 10-Mounting bracket. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1 and Figure 8 This invention provides a technical solution: a stamping device for stamping parts, the upper die mainly including a pressure ring 1, an upper punch 21, and a lower punch 22. The pressure ring 1 is used to pre-press the edge of the area of ​​the workpiece that needs to be stretched. A first nitrogen spring is provided between the pressure ring 1 and the upper die base. Compared with ordinary linear springs, the nitrogen spring has a relatively constant initial pressure value and will not compress before reaching this pressure. The upper punch 21 is an annular cylindrical body, and its lower end can extend to near half the depth of the stretching area of ​​the workpiece. A second nitrogen spring is provided between the upper end of the upper punch 21 and the upper die base. The stroke of the first nitrogen spring is greater than that of the second nitrogen spring. The lower punch 22 has a T-shaped cross-section. A first reset member is provided between the upper end of the lower punch 22 and the upper die base. The first reset member is preferably a helical spring. The elastic force of the helical spring will generate a larger reaction force as the stretching or compression stroke increases. The lower punch 22 provides the extension of the lower edge of the workpiece during stretching, such as... Figure 1 As shown, when stretching and flanging are combined, if punch 2 cannot move down to the lowest point of the stretch, a state as shown in 8b2 will occur, where the lower end of the stretch converges towards the axis. Only when the stretching and flanging are combined will the lower end of the stretch converge towards the axis. Figure 8 As shown in b3, it can be fully stretched. Since the flip plate needs enough space, after the lower punch 22 moves down and stretches, space needs to be made for the flipping edge. Therefore, the first reset member is used to move the lower punch 22 up and return it to the state of being in contact with the upper punch 21.

[0036] See Figure 1 , Figure 2 and Figure 3 The lower mold includes a material support plate 3, a screw 4, a lower core 5, and a flanging cutter block 6. The material support plate 3 has two semi-open lobes. Because it needs to open to the side after flanging to pick up the material, the material support plate 3 has two actions. First, during the pressing of the pressure ring 1, the two lobes merge to form a cavity (also with a spring for reset). Second, it continues to move down to drive the lower core 5. A third nitrogen spring is provided between the material support plate 3 and the lower mold base. The initial force of the third nitrogen spring is greater than the initial force of the first nitrogen spring corresponding to the pressure ring 1. Since the material support plate 3, which is similar to a wedge, is a conventional structure in the mold, it will not be described in detail.

[0037] The lower core 5 is frustum-shaped, with its lower end slidingly disposed in the lower mold base along the mold opening direction. A spiral groove 51 is formed at the lower end of the lower core 5, and a screw 4 adapted to the spiral groove 51 is fixed on the lower mold base accordingly. A step is also provided in the middle of the lower core 5, and a third reset member 8 is provided between the step and the lower mold base. The third reset member 8 is preferably a spiral spring. Several sliding grooves 52 are formed at the upper end of the lower core 5. The sliding grooves 52 are used to install the flanging cutter block 6. The sliding grooves 52 start from the upper end of the lower core 5 and extend radially outward along the axial direction of the lower core 5, forming an overall arc shape. The slide 52 is equipped with protrusions on both sides of the slide 52 to form a limited slide rail. The side walls of the flanged blade 6 are provided with limiting strips 61. The limiting strips 61 slide in the slide 52. At least three sets of flanged blades 6 are provided and are evenly distributed in the circumference. Preferably, there are four or five sets. If there are too few flanged blades 6, the lower core 5 needs to move down a large stroke. The arc surface of the flanged blade 6 and the arc surface of the slide 52 are both provided with semi-annular grooves. The two form a complete arc-shaped columnar groove. The second reset member 7 is provided in the columnar groove. The second reset member 7 is also preferably a helical spring, and its two ends are fixed to the flanged blade 6 and the slide 52 respectively.

[0038] like Figure 2 As shown, a flange can also be provided on the outer edge of the lower core 5, and a nitrogen spring can be installed through the flange;

[0039] See Figure 4 , Figure 5 , Figure 6 and Figure 7Specifically, the workpiece is first placed on the support plate 3, the upper die moves downward, and the pressure ring 1 contacts the workpiece first and applies pressure. At this time, the two halves of the support plate 3 close together as it moves downward to form a cavity. Then, the support plate 3 is limited by the third nitrogen spring and no longer moves. Because the initial force of the third nitrogen spring is greater than that of the first nitrogen spring, the pressure ring 1 moves upward relative to the upper die seat, and the punch 2 moves downward relative to the pressure ring 1, thus starting the stretching process. In the initial state, the two parts are stretched as a whole under the limitation of the upper punch 21. When the upper punch 21 is fully in contact with the workpiece, the initial force of the third nitrogen spring is greater than the sum of the second and first nitrogen springs, and the second nitrogen spring corresponding to the upper punch 21 is compressed. After compression, the pressure ring 1 moves downward. As the upper die holder continues to move downwards, the lower punch 22 moves downwards to continue stretching the remaining portion. The initial elastic force of the first reset member corresponding to the lower punch 22 is greater than the stretching force required for stretching the remaining portion, thus completing the stretching action. After the stretching action is completed, as the upper die holder continues to move downwards, the third nitrogen spring corresponding to the support plate 3 begins to compress, meaning that both the upper die and the support plate 3 move downwards as a whole and contact the flanging cutter block 6 on the lower core 5. Because the flanging cutter block 6 is in a position beyond the upper end face of the lower core 5 under the action of the second reset member 7, it begins to push the flanging cutter block 6 downwards. The sum of the initial compression forces of all the second reset members 7 is less than the initial force of the third reset member 8 and the friction force of the spiral groove 51, meaning that the flanging cutter block 6 slides first. Figure 4 and Figure 5 As shown, Figure 4 Y1 in the figure represents the line of action of the flanged surface, and the process is as follows: Figure 5 In the process, a1 and a2, starting from the edge, radially extrude the workpiece to create a flange. After sliding, the third reset piece 8 is compressed, and under the action of the screw 4, the lower core 5 rotates, entering the second stage, as shown below. Figure 6 As shown, due to the rotation of the lower core 5, the top view of the actual trajectory of the fixed point on the Y1 action line is spiral-like (a spatial spiral in three-dimensional space), therefore its front view is as follows. Figure 7 As shown, it is also a planar spiral shape. After the flanging blade 6 rotates for one cycle (that is, the circumferential angle between two adjacent flanging blades 6), the flanging is completed. However, the lower core 5 continues to rotate and rotates for at least one more cycle for pressing and shaping, finally completing the stretching and flanging.

[0040] See Figure 9 The action line Y1 of the flanging blade block 6 is composed of multiple rolling shafts 9. A groove adapted to the rolling shaft 9 is opened on the action line of the action surface of the flanging blade block 6. The two ends of the rolling shaft 9 are rotatably installed on the groove and limited by snap rings. The rolling friction of the rolling shaft 9 replaces the sliding friction, thereby avoiding scratches on the workpiece surface.

[0041] In one embodiment, the cross-sectional line of the outer circumferential surface of the rolling shaft 9 on the flanging cutter block 6 is concave towards the axis. That is, the rolling shaft 9 is a columnar body with a large diameter at both ends and a small diameter in the middle. Only the two ends of the rolling shaft 9 are in contact with the workpiece. Each point on the rolling shaft 9 forms a Y1 line of action. The curvature of the concave cross-section of the rolling shaft 9 is greater than or equal to the final curvature of the Y1 line of action, so as to prevent multiple points on the rolling shaft 9 from contacting the workpiece and causing protrusion.

[0042] See Figure 10 In another embodiment, the outer circumferential surface of the rolling shaft 9 on the flanging cutter block 6 is convex, that is, the rolling shaft 9 is similar to a spindle structure, and its convexity means that only one point contacts the workpiece surface.

[0043] Furthermore, based on the embodiment with the protruding rolling shaft 9, the rolling shaft 9 is configured to be able to swing at both ends to change the position of the axis, i.e., as shown in the example... Figure 11 Specifically, a tuning fork-shaped mounting bracket 10 is installed on the line of action of the flanging cutter block 6. The mounting part of the mounting bracket 10 can rotate, and the fork part is rotatably mounted to both ends of the rolling shaft 9. Thus, the rolling shaft 9 can rotate on its own axis or around the mounting axis of the mounting bracket 10. Setting the rolling shaft 9 in a way that can change the axis angle can make it roll better, because as the flanging cutter block 6 slides and rotates on the lower core 5, its actual sliding angle relative to the workpiece changes. Therefore, this setting can make it adaptively change the angle, thus only rolling and avoiding sliding.

[0044] See Figure 4 In the initial state of the flange cutting block 6, the corner that first separates from the lower punch 22 is rounded to facilitate sliding and prevent scratches from forming on the punch 2.

[0045] A stamping method for a stamping device for stamping parts includes the following steps;

[0046] S1 is a single stretching operation, in which the upper punch 21 and the lower punch 22 move down relative to the workpiece simultaneously to stretch the workpiece.

[0047] S2 Secondary stretching: After the upper punch 21 fully contacts the workpiece, the lower punch 22 continues to move downward to complete the stretching of the flanged part.

[0048] S3 flanging, flanging includes the following two sub-steps:

[0049] A1 expansion and flanging: the lower punch 22 moves down and drives the flanging cutter block 6 to slide. During the rotation of the lower core 5, the flanging cutter block 6 expands outward radially and rotates circumferentially to form an overall expansion.

[0050] After the A2 molding is completed, the lower core 5 continues to rotate, driving the flanging cutter block 6 to rotate, thereby fixing the flanging position.

[0051] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stamping device for stamping parts, comprising a blank holder (1) that slides up and down along the die opening direction, a first nitrogen spring provided between the blank holder (1) and the upper die, and a punch (2) slidably disposed at the middle position of the blank holder (1) and mounted on the upper die, characterized in that: The punch (2) consists of an upper punch (21) and a lower punch (22). The upper punch (21) and the lower punch (22) are separated by the middle of the stretching depth. The upper punch (21) is cylindrical and slides with the lower punch (22). A second nitrogen spring is provided between the upper punch (21) and the upper die. A first reset member is provided between the lower punch (22) and the upper die. A support plate (3) is installed on the lower die below the pressure ring (1). A third nitrogen spring is connected between the support plate (3) and the lower die. The support plate (3) is divided into two halves with the axis of the lower punch (22) as the center. The two halves of the support plate (3) close to form a stretching and flanging cavity during the downward movement along the mold opening direction. A screw is fixed below the lower punch (22) of the lower die. 4), and the screw (4) is connected to the lower core (5) through the spiral groove (51). At least three sets of flanging blades (6) are arranged in a circular array around the axis on the upper end face of the lower core (5). The flanging blades (6) and the lower core (5) are slidably connected. A second reset member (7) is provided between the flanging blades (6) and the lower core (5). In the initial state, one end of the flanging blade (6) extends beyond the upper end face of the lower core (5). It slides under the contact of the lower punch (22) and flanging the workpiece. During the process of the lower punch (22) contacting the flanging blades (6), the lower core (5) rotates under the action of the screw (4) and the flanging blades (6) rotate in a circular motion. A third reset member (8) is provided between the lower core (5) and the lower die.

2. The stamping device for stamping parts according to claim 1, characterized in that: The working surface of the flanging tool block (6) is curved, and the working surface is in line contact with the workpiece.

3. The stamping device for stamping parts according to claim 2, characterized in that: A rolling shaft (9) is rotatably mounted on the flanging cutter block (6). Multiple sets of rolling shafts (9) are provided. The contact point between the rolling shaft (9) and the workpiece forms an action surface to generate rolling pressure.

4. The stamping device for stamping parts according to claim 3, characterized in that: The circumferential surface of the rolling shaft (9) is concave towards the axis, and the circumferential edge line corresponding to its cross section through the axis is always in contact with the workpiece at two points.

5. A stamping device for stamping parts according to claim 3, characterized in that: The circumferential surface of the rolling shaft (9) is convex spindle-shaped.

6. A stamping device for stamping parts according to claim 5, characterized in that: A tuning fork-shaped mounting bracket (10) rotates on the flanging cutter block (6). The two ends of the rolling shaft (9) are rotatably connected to the mounting bracket (10). When the flanging cutter block (6) moves in a spiral shape, the rolling shaft (9) changes its tilt angle according to the shape of the workpiece surface.

7. A stamping device for stamping parts according to claim 1, characterized in that: The screw (4) causes the flanging cutter block (6) to rotate at an angle that is at least twice the circumferential angle between two adjacent flanging cutter blocks (6), and the workpiece completes flanging when the flanging cutter block (6) rotates to the middle of its stroke.

8. A stamping device for stamping parts according to claim 1, characterized in that: The initial contact surface between the flanged blade block (6) and the lower punch (22) is an arc-shaped surface.

9. The stamping method of the stamping device for stamping parts according to claim 1, characterized in that, Includes the following steps: S1 stretching, the upper punch (21) and the lower punch (22) move down relative to the workpiece simultaneously to stretch; S2 Secondary stretching: After the upper punch (21) fully contacts the workpiece, the lower punch (22) continues to move down to complete the stretching of the flanged part; S2 flanging, flanging includes the following two sub-steps: A1 expansion and flanging: the lower punch (22) moves down and drives the flanging blade (6) to slide. During the rotation of the lower core (5), the flanging blade (6) expands outward in the radial direction and rotates in a circular motion to form an overall expansion. After the A2 mold is solidified and expanded, the lower core (5) continues to rotate, driving the flanging cutter block (6) to rotate, thereby solidifying the flanging position.

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