A bending mold and a bending method

Abstract

This invention discloses a bending forming die, comprising a concave die, a central punch, side punches, and a compression spring. Two side punches are symmetrically distributed on both sides of the central punch, and the central punch is movable relative to the side punches. The concave die has a groove and two inclined forming surfaces, the intersection of the extension lines of the two inclined forming surfaces being located within the groove. The central punch has a bending head, which is positioned corresponding to the groove. The bending head has a V-shaped cross-section and an upper surface. A compression spring is disposed between the side punches and the central punch, and the side punches abut against the upper surface of the bending head under the action of the compression spring. The bending head and the two side punches together form a V-shaped punch. This invention can produce bent parts with good dimensional accuracy using only any single-action press and requiring only one bending forming action. The die structure of this invention is simple, and it features convenient operation, high forming accuracy, and high processing flexibility.

Description

Technical Field

[0001] This invention relates to a bending forming mold and a bending method, belonging to the field of sheet metal bending forming technology. Background Technology

[0002] In practical engineering applications, conventional bending methods for sheet metal often result in significant springback, requiring multiple bends and affecting product dimensional accuracy. Pull bending processes impose strict requirements on part shape and have low processing efficiency. While pressure bending reduces springback, it requires significant forming force, lowering die durability, and can cause indentations on the sheet metal surface, affecting appearance quality. Springback-compensating bending methods suffer from poor processing flexibility; a single die can only maintain high-precision forming for specific materials and specifications. Summary of the Invention

[0003] In order to overcome the problems existing in the prior art, the present invention provides a bending forming mold and bending method, which helps to reduce springback after bending. The specific technical solution is as follows.

[0004] A bending forming die, characterized in that it includes a concave die, a central punch, a side punch, and a compression spring;

[0005] The two side punches are symmetrically distributed on both sides of the central punch, and the central punch is movable relative to the side punches;

[0006] The concave mold has a groove and two inclined forming surfaces, and the intersection of the extension lines of the two inclined forming surfaces is located in the groove;

[0007] The central punch mold has a bending head, which is arranged corresponding to the groove, and the cross-sectional width of the bending head is smaller than the cross-sectional width of the groove; the cross-section of the bending head is V-shaped, and the bending head has an upper surface;

[0008] A compression spring is provided between the side punch and the center punch, and the side punch abuts against the upper surface of the bending head under the action of the compression spring; the bending head and the two side punches together form a V-shaped punch.

[0009] Using the above technical solution, the bending head and the two side punches together form a V-shaped punch, which, in conjunction with the die, can bend the sheet metal. At the same time, after the sheet metal is bent, the central punch can continue to press down relative to the side punches for further bending, thereby reducing the springback of the bent sheet metal.

[0010] Furthermore, the central punch includes a vertical support component, a horizontal support component, and the bending head. Two side punches are located on either side of the vertical support component. The bending head is fixed to the lower end of the vertical support component and is also located below the side punches. The horizontal support component is fixedly connected to the vertical support component and is located above the side punches. The compression spring is located between the horizontal support component and the side punches. The horizontal support component is provided to better position the compression spring and ensure that the side punches can move between the bending head and the horizontal support component. The vertical support component can serve as a sliding guide for the side punches, defining the relative movement position between the side punches and the vertical support component.

[0011] Furthermore, the horizontal support component is provided with a through hole, and the side punch is provided with a threaded hole corresponding to the through hole. A bolt passes through the through hole and is screwed into the threaded hole, and a compression spring is sleeved on the bolt. The compression spring applies a downward elastic force to the side punch, causing the side punch to abut against the upper surface of the bending head. The bolt both positions the compression spring and allows the distance between the horizontal support component and the side punch to change, accommodating further downward pressure from the central punch. Simultaneously, by replacing different compression springs, the elastic force of the compression spring can be adjusted, that is, the pressure of the side punch pressing against the sheet metal can be adjusted to adapt to the bending requirements of different materials.

[0012] Based on the same inventive concept, this invention also relates to a bending method, which employs the aforementioned bending forming mold and mainly includes the following steps:

[0013] 1) The sheet metal is placed on the concave mold, and the central punch and the side punch move downward together to bend the sheet metal. The bent sheet metal is clamped between the concave mold and the side punch.

[0014] 2) While keeping the side punches tightly against the plate, the center punches move further downward to press down on the plate. At this time, the side punches separate from the upper surface of the bending head.

[0015] 3) The central punch and the side punches move upward to remove the sheet metal.

[0016] Further, in step 2) above, the distance by which the central punch moves downward is 0.08-0.5 times the thickness of the plate; preferably, the distance by which the central punch moves downward is 0.1 times the thickness of the plate.

[0017] This invention can produce bent parts with good dimensional accuracy using only any single-action press and a single bending forming action. The mold structure of this invention is simple and has the characteristics of convenient operation, high forming accuracy and great processing flexibility. That is, only one set of molds is needed to form bent parts of various materials and different specifications with high precision. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the bending forming mold of the present invention (bending first stage);

[0019] Figure 2 This is a schematic diagram of the bending forming mold of the present invention (bending stage 2);

[0020] Figure 3 This is a schematic diagram of the die cavity;

[0021] Figure 4 This is a schematic diagram of the central punch;

[0022] Figure 5 This is a schematic diagram of the side punch;

[0023] Figure 6 yes Figure 1 Enlarged view of region A in the middle;

[0024] Figure 7 This is a simulation diagram of bending using a traditional integrated bending punch, where (a) shows the angle before springback, (b) shows the angle after springback, and (c) shows the change in sheet thickness.

[0025] Figure 8 This is a simulation diagram of the bending of the split bending punch of the present invention, wherein (a) shows the angle before springback, (b) shows the angle after springback, and (c) shows the change in sheet thickness.

[0026] In the figure: 1. Die 1.1. Groove 1.1. Inclined forming surface 1.2. Center punch 2.1. Bending head 2.1. Upper surface 2.1.1. Vertical support component 2.2. Horizontal support component 2.3. Through hole 2.3.1. Side punch 3. Screw hole 3.1. Compression spring 4. Bolt 5. Plate 6. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings.

[0028] See Figures 1-6 A bending forming die, comprising a concave die 1, a central punch 2, a side punch 3, and a compression spring 4;

[0029] Two side punches 3 are symmetrically distributed on both sides of the central punch 2, and the central punch 2 can move relative to the side punches 3;

[0030] The die 1 has a groove 1.1 and two inclined forming surfaces 1.2, and the intersection of the extension lines of the two forming surfaces 1.2 is located inside the groove 1.1;

[0031] The central punch 2 has a bending head 2.1, which is set corresponding to the groove 1.1, and the cross-sectional width of the bending head 2.1 is smaller than the cross-sectional width of the groove 1.1; the cross-section of the bending head 2.1 is V-shaped, and the bending head 2.1 has an upper surface 2.1.1; the cross-sectional width of the bending head 2.1 is smaller than the cross-sectional width of the groove 1.1 to ensure that the bending head 2.1 can extend into the groove 1.1 to achieve secondary stretching of the bent plate.

[0032] A compression spring 4 is provided between the side punch 3 and the center punch 2. Under the action of the compression spring 4, the side punch 3 abuts against the upper surface 2.1.1 of the bending head 2.1; the bending head 2.1 and the two side punches 3 together form a V-shaped punch.

[0033] The central punch 2 includes a vertical support component 2.2, a horizontal support component 2.3, and a bending head 2.1. Two side punches 3 are located on either side of the vertical support component 2.2. The bending head 2.1 is fixed to the lower end of the vertical support component 2.2 and is also located below the side punches 3. The horizontal support component 2.3 is fixedly connected to the vertical support component 2.2 and is located above the side punches 3. A compression spring 4 is located between the horizontal support component 2.3 and the side punches 3. The horizontal support component 2.3 is provided to better position the compression spring 4 and ensure that the side punches 3 can move between the bending head 2.1 and the horizontal support component 2.3. The vertical support component 2.2 can serve as a sliding guide for the side punches 3, defining the relative movement position between the side punches 3 and the vertical support component 2.2. The vertical support component 2.2 and the horizontal support component 2.3 can be integrally formed or have a separate structure; the vertical support component 2.2 and the horizontal support component 2.3 can be detachably connected by fasteners. In a preferred embodiment, the bending head 2.1 is detachably connected to the vertical support component 2.2, so that when a bending head 2.1 with a different bending angle is required, it is convenient to replace the corresponding bending head 2.1.

[0034] Preferably, the horizontal support component 2.3 is provided with a through hole 2.3.1, and the side punch 3 is provided with a screw hole 3.1 corresponding to the through hole 2.3.1. The bolt 5 passes through the through hole 2.3.1 and is screwed into the screw hole 3.1, and the compression spring 4 is sleeved on the bolt 5. The compression spring 4 applies a downward elastic force to the side punch 3, so that the side punch 3 abuts against the upper surface 2.1.1 of the bending head 2.1. The bolt 5 not only positions the compression spring 4, but also allows the distance between the horizontal support component 2.3 and the side punch 3 to change, so as to accommodate further downward pressure from the central punch 2. At the same time, by replacing different compression springs 4, the elastic force of the compression spring 4 can be adjusted, that is, the pressure of the side punch 3 pressing against the plate 6 can be adjusted, so as to adapt to the bending requirements of different materials.

[0035] This invention also relates to a bending method, which uses the above-mentioned bending forming mold and mainly includes the following steps:

[0036] 1) Place the sheet 6 on the die 1, and move the central punch 2 and the side punch 3 downward together to bend the sheet 6. The bent sheet 6 is held between the die 1 and the side punch 3 (first stage of bending).

[0037] 2) While keeping the side punch 3 tightly against the plate 6, the center punch 2 moves further downward to press down on the plate 6. At this time, the side punch 3 separates from the upper surface 2.1.1 of the bending head 2.1 (first stage of bending).

[0038] 3) The central punch 2 and the side punch 3 move upward to remove the sheet metal 6.

[0039] Further, in step 2) above, the downward movement distance of the central punch 2 is 0.08-0.5 times the thickness of the sheet 6; preferably, the downward movement distance of the central punch 2 is 0.1 times the thickness of the sheet 6. The central punch 2 can continue to press down relative to the side punch 3 for further bending, thereby reducing the springback of the bent sheet 6.

[0040] Figures 7-8 The simulation shows the bending results of a 2mm thick sheet metal using a traditional one-piece bending die and a separate bending die (center and side dies) as described in this application. The springback angle after bending with the traditional one-piece bending die is 1.2 degrees, while the springback angle with the separate bending die is 0.3 degrees. The center die 2 moves further into the downward groove 1.1 by a distance equal to 0.1 times the thickness of the sheet metal 6. Furthermore, the minimum thickness of the sheet metal after bending using the two methods differs by only 0.01mm, indicating that the bending method of this application has a smaller impact on the sheet thickness variation.

[0041] The embodiments of the present invention have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention is not limited to the specific embodiments described above; these embodiments are merely illustrative and not limiting. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the scope of protection of the present invention.

Claims

1. A bending forming die, characterized in that, It includes a concave die (1), a central punch (2), a side punch (3), and a compression spring (4); The two side punches (3) are symmetrically distributed on both sides of the central punch (2), and the central punch (2) can move relative to the side punches (3); The die (1) has a groove (1.1) and two inclined forming surfaces (1.2), and the intersection of the extensions of the two inclined forming surfaces (1.2) is located in the groove (1.1); The central punch (2) has a bending head (2.1), which is provided corresponding to the groove (1.1), and the cross-sectional width of the bending head (2.1) is smaller than the cross-sectional width of the groove (1.1); the cross-section of the bending head (2.1) is V-shaped, and the bending head (2.1) has an upper surface (2.1.1). A compression spring (4) is provided between the side punch (3) and the center punch (2), and the side punch (3) abuts against the upper surface (2.1.1) of the bending head (2.1) under the action of the compression spring (4); the bending head (2.1) and the two side punches (3) together form a V-shaped punch; The central punch (2) includes a vertical support component (2.2), a horizontal support component (2.3), and a bending head (2.1). The two side punches (3) are located on both sides of the vertical support component (2.2). The bending head (2.1) is fixed to the lower end of the vertical support component (2.2) and is also located below the side punches (3). The horizontal support component (2.3) is fixedly connected to the vertical support component (2.2) and is located above the side punches (3). The compression spring (4) is located between the horizontal support component (2.3) and the side punches (3). The horizontal support component (2.3) is provided with a through hole (2.3.1), and the side punch (3) is provided with a screw hole (3.1) corresponding to the through hole (2.3.1). The bolt (5) passes through the through hole (2.3.1) and is screwed into the screw hole (3.1). The compression spring (4) is sleeved on the bolt (5).

2. A bending method, which employs the bending forming mold as described in claim 1, mainly includes the following steps: 1) Place the plate (6) on the concave mold (1), and move the central punch (2) and the side punch (3) downward together to bend the plate (6). The bent plate (6) is clamped between the concave mold (1) and the side punch (3). 2) While keeping the side punch (3) close to the plate (6), the center punch (2) moves further downward to press down on the plate (6). At this time, the side punch (3) separates from the upper surface (2.1.1) of the bending head (2.1). 3) The central punch (2) and the side punch (3) move upward to remove the plate (6).

3. The bending method according to claim 2, characterized in that, In step 2) above, the distance by which the central punch (2) moves downward is 0.08-0.5 times the thickness of the plate (6).

4. The bending method according to claim 3, characterized in that, The central punch (2) moves downward a distance equal to 0.1 times the thickness of the plate (6).

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