Dovetail-shaped sheet metal part one-time bending forming die and bending method

Abstract

The dovetail-shaped sheet metal part one-time bending forming die comprises an upper die assembly and a lower die assembly, the upper die assembly comprises an upper die body and die heads, the two sides of the upper die body are provided with inclined faces matched with the dovetail shape, upper fillet outer side forming faces and upper planes, and the die heads are symmetrically arranged on the bottom face of the upper die body. The outward end of the die head is provided with a lower fillet inner side forming face matched with the dovetail shape. When the die head is in a relaxed state, a certain gap is formed between the die head and the bottom face of the upper die body. The lower die assembly comprises a lower die base, two inserts are symmetrically arranged on the top of the lower die base, and a forming groove matched with the dovetail shape is formed in one side of each insert. When the two inserts are in a relaxed state, the opening width is larger than the maximum width of the dovetail shape, and when the upper die and the lower die are closed, the two inserts rotate in the opposite directions, so that the two forming grooves form the dovetail shape; one-time forming of the swallow-tail-shaped sheet metal part can be achieved only through interaction of the upper die and the lower die, additional driving or a reset mechanism such as a spring is not needed, and cost is lower.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bending, in particular to a dovetail-shaped sheet metal part one-time bending forming die and a bending method. BACKGROUND

[0002] The sheet metal part of dovetail structure has a wide application in the fields of mechanical manufacturing, automobile accessories, electronic equipment, etc. due to its unique shape. The traditional bending processing methods of the sheet metal part of dovetail structure are various, some of which adopt complex die structure to cooperate with cylinder driving device for bending, however, such device has a complex structure, high cost and high maintenance difficulty; some others adopt general bending machine to complete the bending through manual or mechanical hand positioning for multiple times, which has problems of low production efficiency, poor product consistency, high labor cost and safety hazards, etc. Moreover, the traditional method is not convenient enough in the demolding process after forming, which is prone to cause demolding difficulty and damage to the workpiece.

[0003] Therefore, it is of great significance to develop a device with simple structure, without complex driving device, which can realize one-time bending forming of the sheet metal part of dovetail structure and convenient demolding only by relying on the shape of the upper and lower dies, so as to improve the production efficiency, ensure the product quality and reduce the production cost. SUMMARY

[0004] The present application relates to the technical field of bending, in particular to a dovetail-shaped sheet metal part one-time bending forming die and a bending method.

[0005] The specific scheme of the present application is as follows: the dovetail-shaped sheet metal part one-time bending forming die comprises an upper die assembly and a lower die assembly, the upper die assembly comprises an upper die main body and a die head, the upper die main body is provided with a matching inclined surface, an upper round corner outside forming surface and an upper plane on both sides of the upper die main body, the die head is provided with a matching lower round corner inside forming surface on the end thereof facing outward, the two die heads are connected with the upper die main body through stepped screws, and the die head has a certain gap with the bottom surface of the upper die main body when the die head is in a relaxed state; the lower die assembly comprises a lower die seat, the lower die seat is provided with two circular-arc-shaped grooves on the top thereof, each of the two circular-arc-shaped grooves is provided with an insert block, the side of the insert block facing the lower die seat is provided with a circular-arc-shaped surface matching the circular-arc-shaped groove, and the other side of the insert block is provided with a forming groove matching the dovetail shape; the opening width of the two insert blocks in the relaxed state is greater than the maximum width of the dovetail shape, and the two forming grooves form the dovetail shape when the upper die and the lower die are closed.

[0006] Further, the bottom surface of the upper die main body is provided with a large-to-small trapezoidal table in the center thereof, the side of the die head facing the trapezoidal table is provided with a matching inclined surface, the die head is provided with a waist-shaped hole corresponding to the stepped screw, and the long axis of the waist-shaped hole is arranged in the transverse direction.

[0007] Furthermore, the forming groove includes an inclined surface matching the side of the dovetail shape, an outer forming surface with a lower rounded corner matching the dovetail shape, and a bottom plane matching the bottom of the dovetail shape.

[0008] Furthermore, the upper end of the insert is provided with an inner rounded corner forming surface that matches the dovetail shape and a plane that matches the top of the dovetail shape.

[0009] Furthermore, the upper mold body, mold head, lower mold base, and inserts are all made of high-strength, high-hardness metal materials to ensure that they do not deform during multiple bending and forming processes and to guarantee forming accuracy.

[0010] Furthermore, the opposing surfaces of the two inserts are flat, and in the relaxed state, these flat surfaces are aligned with the center of the lower mold base.

[0011] This invention also provides a bending method for one-time forming of dovetail-shaped sheet metal parts, using the aforementioned bending mold, with the following specific steps: S1, the workpiece is placed on the lower mold assembly, and the upper mold assembly descends until the mold head contacts the workpiece; S2, the upper mold body continues to descend, the mold head is in close contact with the upper mold body, and then the upper mold body and mold head continue to press the workpiece into the forming grooves of the two inserts; S3, the upper mold assembly continues to descend, pressing the workpiece to the bottom, and the downward pressure pushes the two inserts to rotate along the arc-shaped grooves on both sides, and the inserts cooperate with the upper mold assembly to achieve dovetail forming; S4, the upper mold assembly returns, and the two inserts gradually return to their original position due to their own weight, causing the workpiece and the upper mold assembly to separate from the two inserts; S5, the mold head and the workpiece slide downward due to their own weight to form a preset gap, and finally the workpiece separates from the upper mold assembly along its length.

[0012] Compared with existing technologies, this invention has the following advantages: The invention utilizes a unique design for the lower die, lower die insert, and upper die structure. The lower die insert is symmetrically arranged in two parts, with a cylindrical contact surface with the lower die. The upper die is designed as a split type, with the die head at the dovetail connected to the upper die body by screws and a gap provided to create a movement space. Relying solely on the interaction of the shapes of the upper and lower dies, when the upper die presses down, the die head is pressed and forms a single unit with the upper die body, the insert rotates into position, and when the upper die returns, the die head and workpiece separate under gravity, creating a gap. Simultaneously, the insert utilizes self-realignment, eliminating the need for additional drive structures such as cylinders or reset mechanisms such as springs, thus enabling one-time bending and easy demolding of dovetail-shaped sheet metal parts. Compared with traditional bending devices using complex drive mechanisms, this invention has a simple structure, low cost, and convenient maintenance. Compared with traditional multi-process bending methods, this invention significantly shortens the processing cycle and improves production efficiency; it avoids the cumulative errors caused by multiple positioning, improving product dimensional accuracy and consistency; it reduces manual operation, lowers labor intensity and labor costs, and also improves the safety of the production process. This device is highly versatile and can be adapted to the processing needs of dovetail-shaped sheet metal parts of different specifications by changing the lower mold insert. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the upper mold assembly and the lower mold assembly of the present invention;

[0014] Figure 2 This is a schematic diagram showing the state in which the die head of the upper die assembly just contacts the workpiece during the operation of this invention;

[0015] Figure 3 This is a schematic diagram of the upper mold assembly in the downward pressing state during the operation of this invention;

[0016] Figure 4 This is a schematic diagram showing the state in which the bottom surface of the workpiece just contacts the insert when the present invention is in operation;

[0017] Figure 5 This is a schematic diagram of the upper mold assembly being pressed down to the bottom to form a dovetail shape during the operation of this invention;

[0018] Figure 6 This is a schematic diagram showing the upper mold assembly and the workpiece returning to the insert state during the operation of this invention;

[0019] Figure 7 This is a schematic diagram showing the workpiece being prepared to detach from the upper mold during the operation of this invention;

[0020] In the diagram: 1. Upper mold body; 11. Upper plane; 12. Outer forming surface of upper rounded corner; 13. Inclined surface; 2. Step screw; 3. Mold head; 31. Inner forming surface of lower rounded corner; 4. Trapezoidal platform; 5. Lower mold base; 51. Arc-shaped groove; 6. Insert; 61. Outer forming surface of lower rounded corner; 62. Inclined surface; 63. Inner forming surface of upper rounded corner; 64. Plane; 65. Bottom plane. Detailed Implementation

[0021] See Figure 1The embodiment provides a one-time bending forming die for dovetail-shaped sheet metal parts, which comprises an upper die assembly and a lower die assembly, the upper die assembly comprises an upper die main body 1 and a die head 3, the upper die main body 1 is provided with a dovetail-shaped matching inclined surface 13, an upper round corner outer side forming surface 12 and an upper plane 11 on both sides, the die head 3 is arranged symmetrically on the bottom surface of the upper die main body 1 in a number of two, the outer end of the die head 3 is provided with a dovetail-shaped matching lower round corner inner side forming surface 31, the two die heads 3 are connected with the upper die main body 1 through a stepped screw 2, when the die head 3 is in a relaxed state, the die head 3 has a certain gap with the bottom surface of the upper die main body 1, the gap is set according to actual demolding requirements, and the gap ensures that the workpiece can be smoothly separated from the upper die main body 1 when the upper die assembly returns; the lower die assembly comprises a lower die seat 5, the top of the lower die seat 5 is symmetrically provided with two circular-arc-shaped grooves 51, one insert block 6 is arranged in each of the two circular-arc-shaped grooves 51, the side of the insert block 6 facing the lower die seat 5 is provided with a circular-arc-shaped surface matched with the circular-arc-shaped groove 51, and the other side of the insert block 6 is provided with a forming groove matched with the dovetail shape; the opening width of the two insert blocks 6 in the relaxed state is greater than the maximum width of the dovetail shape, and when the upper die and the lower die are combined, the two insert blocks 6 rotate in opposite directions to form the dovetail shape.

[0022] Further, the bottom surface of the upper die main body 1 is provided with a large-at-top-and-small-at-bottom trapezoidal table 4 in the center, the side of the two die heads 3 facing the trapezoidal table 4 is provided with a trapezoidal table 4 matched inclined surface, the die head 3 is provided with a waist-shaped hole corresponding to the stepped screw 2, and the long axis of the waist-shaped hole is arranged in the transverse direction.

[0023] Further, the forming groove comprises a dovetail-shaped side edge matched inclined surface 62, a dovetail-shaped lower round corner outer side forming surface 61 and a dovetail-shaped bottom matched bottom plane 65.

[0024] Further, the upper end of the insert block 6 is provided with a dovetail-shaped upper round corner inner side forming surface 63 and a dovetail-shaped top matched plane 64.

[0025] Further, the upper die main body 1, the die head 3 and the lower die seat 5 and the insert block 6 are all made of high-strength and high-hardness metal materials, so that deformation is avoided in the multiple bending forming process and forming precision is ensured.

[0026] Further, the opposite side of the two insert blocks 6 is a plane and the plane is aligned with the center of the lower die seat 5 in the relaxed state.

[0027] The embodiment also provides a bending method for one-time bending forming of a dovetail-shaped sheet metal part, and the bending method uses the above forming die, as shown in Figures 2-7, specifically comprising the following steps: S1, placing the workpiece on the lower die assembly, and lowering the upper die assembly to contact the workpiece at the die head 3; S2, continuing to lower the upper die body 1, and the die head 3 is in close contact with the upper die body 1, at this time the gap between the die head 3 and the upper die body 1 disappears, then the upper die body 1 and the die head 3 continue to press the workpiece into the forming groove of the two inserts 6; S3, continuing to lower the upper die assembly to press the workpiece to the bottom, the downward pressure drives the two inserts 6 to rotate to the two sides along the arc-shaped grooves, the upper end of the insert 6 extrudes the workpiece from the two sides to the center, and cooperates with the upper die assembly to realize the dovetail forming of the workpiece; S4, the upper die assembly returns, and the two inserts 6 gradually reset due to gravity, so that the workpiece and the upper die assembly are separated from the two inserts 6; S5, the die head 3 and the workpiece slide downward due to gravity, a preset gap is formed between the die head 3 and the upper die body 1, so that the pressure of the workpiece wrapping the upper die is greatly reduced, thereby reducing the friction between the workpiece and the upper die body 1, and finally moving the upper die assembly or the workpiece in the transverse direction, so that the workpiece is separated from the upper die assembly in the length direction.

Claims

1. A one-time folding forming die for a dovetail-shaped sheet metal part, comprising an upper die assembly and a lower die assembly, characterized in that: The upper die assembly comprises an upper die body and a die head, the upper die body is provided with a slope matched with the dovetail shape, an upper rounded outside forming surface and an upper plane on both sides, the die head is two in number and symmetrically arranged on the bottom surface of the upper die body, the end of the die head facing outward is provided with a lower rounded inside forming surface matched with the dovetail shape, and the two die heads are connected with the upper die body through step screws and have a certain gap with the bottom surface of the upper die body when the die head is in a relaxed state; the lower die assembly comprises a lower die seat, the top of the lower die seat is symmetrically provided with two circular arc grooves, one insert block is arranged in each of the two circular arc grooves, the side of the insert block facing the lower die seat is provided with a circular arc surface matched with the circular arc groove, and the other side of the insert block is provided with a forming groove matched with the dovetail shape; the opening width of the two insert blocks in the relaxed state is greater than the maximum width of the dovetail shape, and when the upper die and the lower die are closed, the two insert blocks rotate in opposite directions to form the dovetail shape.

2. The one-time bending forming die for a dovetail-shaped sheet metal part according to claim 1, characterized in that: The bottom surface of the upper die body is provided with a large-to-small trapezoidal table in the center, the side of the two die heads facing the trapezoidal table is provided with a slope matched with the trapezoidal table, and the die head is provided with a waist-shaped hole corresponding to the step screw, and the long axis of the waist-shaped hole is arranged in the transverse direction.

3. The one-time swaging die for a dovetail-shaped sheet metal part according to claim 1, characterized in that: The forming groove comprises a slope matched with the side edge of the dovetail shape, a lower rounded outside forming surface matched with the dovetail shape and a bottom plane matched with the bottom of the dovetail shape.

4. The one-time swaging die for a dovetail-shaped sheet metal part according to claim 1, characterized in that: The upper end of the insert block is provided with an upper rounded inside forming surface matched with the dovetail shape and a plane matched with the top of the dovetail shape.

5. The one-time swaging die for a dovetail-shaped sheet metal part according to claim 1, characterized in that: The upper die body, the die head, the lower die seat and the insert block are all made of high-strength and high-hardness metal materials to ensure that they are not deformed during multiple bending forming processes and ensure the forming precision.

6. The one-time swage die for bending forming a dovetail-shaped sheet metal part according to claim 1, characterized in that: The opposite side of the two insert blocks is a plane and the plane is aligned with the center of the lower die seat in the relaxed state.

7. A method of one-step forming of a dented metal piece, characterized in that: The bending die of any one of claims 1-6 is used in the following specific steps: S1, placing a workpiece on the lower die assembly, and lowering the upper die assembly until the die head contacts the workpiece; S2, continuing to lower the upper die body, the die head is tightly attached to the upper die body, and then the upper die body and the die head continue to press the workpiece into the forming grooves of the two insert blocks; S3, continuing to lower the upper die assembly to press the workpiece to the bottom, the downward pressure drives the two insert blocks to rotate along the circular arc grooves to the two sides respectively, and the insert blocks cooperate with the upper die assembly to realize dovetail forming; S4, the upper die assembly returns, the two insert blocks gradually reset due to gravity, and the workpiece and the upper die assembly are separated from between the two insert blocks; S5, the die head and the workpiece slide downward due to gravity to form a predetermined gap, and finally the workpiece is separated from the upper die assembly along the length direction.

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