TWI796248B - Shell forming die - Google Patents

Abstract

The invention discloses a shell forming die, for forming a to-be-formed part into a shell with a convex sharp angle, the shell forming die includes: a die cavity with an inner concave sharp corner corresponding to the convex sharp angle of the shell; a punch for extruding the to-be-formed part, so that the to-be-formed part is deformed in the die cavity to have a first arced corner and a side wall, and the side wall is connected to one end of the first arced corner; and a pushing block is arranged adjacent to the punch, and its moving direction is the same as that of the punch, is used to push an end face of the side wall, so that at least part of the material of the first arced corner and/or the side wall is plastically deformed to form the convex sharp angle and a second arced corner adjacent to one end of the convex sharp angle simultaneously.

Description

Shell Forming Mold

The invention relates to a stamping forming technology, in particular to a shell forming method and a forming die.

With the rapid growth of the 3C product market, in addition to the performance of 3C products such as notebook computers and mobile phones, product appearance is also the focus of consumers' attention. Due to the high unit price of metal itself and the relatively complicated forming process, 3C products with metal shell parts have become a symbol of high-end products. Following the trend of 3C products, the thickness of metal shell parts is getting thinner and the styling lines are sharp and fashionable. This trend has brought considerable challenges to the forming of metal shell parts.

Among the existing processing methods of metal shell parts, drawing technology has the lowest forming cost and the fastest forming speed. Extruded and bent, the material at the rounded corner is subjected to considerable tensile stress on the side close to the mold cavity, which causes the thickness of the material at the rounded corner to become thinner, which is likely to cause the following defects: when the radius of the rounded corner is too small, it is easy to be difficult for the forming process The middle is broken at the fillet, which limits the radius of the fillet and makes it difficult to form a sharp angle; the rigidity of the fillet of the shell becomes poor; and the dimensional error of the fillet is caused.

How to provide a stamping forming technical solution for the manufacture of metal shell parts to solve the above problems has become one of the issues that people in this technical field are concerned about.

The object of the present invention is to provide a shell forming method and a forming mold thereof, which can form sharp-edged metal shells by stamping technology.

Another object of the present invention is to provide a shell forming method and its forming die, which can avoid material thickness thinning and cracking at arc corners of metal shells during stamping.

Another object of the present invention is to provide a shell forming method and its forming die, which can form a metal shell with uniform material thickness by stamping technology.

Another object of the present invention is to provide a shell forming method and its forming die, which can be used to form metal shells with arc angle dimensional accuracy by stamping technology.

According to above-mentioned purpose, the present invention provides a kind of casing forming method, and its step comprises: provide a to-be-formed part and a mould; Pressurize this to-be-formed part with a punch of this mold and a mold cavity, make this to-be-formed part Forming a first arc angle, one end of the first arc angle is connected to a bottom, and the other end is connected to a side wall; The ejector block and the first arc constrained by the mold cavity and/or at least part of the material of the side wall are plastically deformed to simultaneously form an outwardly convex corner and a second arc adjacent to one end of the outwardly convex corner, so as to Form a shell.

In one embodiment, the other end of the protruding corner is adjacent to the side wall.

R₂

2t₂。 In one embodiment, the shell has a thickness t ₂ , the second arc angle has a radius R ₂ , and the thickness t ₂ has the following relationship with the radius R ₂ : t ₂

R ₂

2t ₂ .

In one embodiment, the object to be formed is a plate, and the plate is a fiber metal laminate (FML).

In one embodiment, the object to be formed is a shell blank, and the shell blank includes a bend.

In one embodiment, the curved angle is a third arc angle or an oblique angle.

In one embodiment, the mold further includes a lower mold and a side module, the lower mold and the side module are combined to form a mold cavity of the mold, and the workpiece to be formed is squeezed by the punch in the mold cavity The adjacent part of the lower mold and the side module forms the first arc angle.

In one embodiment, during the step of pushing the push block against the end face of the side wall, the punch continues to press against the bottom of the workpiece to be formed, and the push block pushes the end face of the side wall downward, so that the first A curved corner and/or plastically deforms at least part of the material of the sidewall to form the outwardly convex corner.

In one embodiment, the mold further includes a lower mold, the lower mold has the mold cavity, the mold cavity has a concave sharp corner, and the workpiece to be formed is squeezed by the punch in the mold cavity and adjacent to the mold cavity. The first arc angle is formed at the concave sharp corner.

In one embodiment, during the step of pushing the push block against the end surface of the side wall, the punch continues to press against the bottom of the object to be formed, and the push block presses down against the first part of the object to be formed. For arc corners, a resisting groove of the pushing block pushes against the end surface of the side wall, so that at least part of the material of the first arc corner and/or the side wall is plastically deformed to form the outwardly convex sharp corner.

According to the above-mentioned purpose, the present invention provides a shell forming die, which is used to form a workpiece to be formed into a shell with a protruding sharp corner. The shell forming mold includes: a mold cavity with a corresponding shell An inner concave sharp corner of the outer convex sharp corner; a punch, used to extrude the to-be-formed part, so that the to-be-formed part is deformed into a first arc angle and a side wall in the mold cavity, and the side wall is connected to at one end of the first arc angle; and a pusher block, which is arranged adjacent to the punch, and whose movement direction is the same as the punch, and is used to push an end surface of the side wall so that the punch and the punch The cavity or the ejector block and the first arc angle constrained by the cavity and/or at least part of the material of the side wall are plastically deformed to fill the concave corner to form the convex corner of the shell, And at the same time, a second arc angle is formed, and the second arc angle is adjacent to the convex sharp corner.

In one embodiment, the mold cavity is formed by a lower mold and a side module, and the concave sharp corner is located at the adjacent part of the lower mold and the side module.

In one embodiment, when the pushing block moves to contact the side module, the side module can move with the pushing block, and when the upper surface of the side module is at the same height as the end surface of the side wall of the workpiece to be formed, The pushing block touches and then pushes the end surface of the side wall.

In one embodiment, the pushing block pushes the side wall, causing the first arc angle and/or at least part of the material of the side wall to be plastically deformed, so as to fill the punch, the lower mold and the side module. Space.

In one embodiment, the pushing block pushes against the side wall, so that at least part of the material of the first arc and/or the side wall is plastically deformed, and attached to the lower mold and the side module.

In one embodiment, the mold cavity is located in the lower mold, and a corner of the pushing block close to the mold cavity and facing the inner wall of the mold cavity is provided with an abutment groove, and the abutment groove is used to push the to-be-formed The end face of the side wall of the piece.

In one embodiment, the pushing block has a nose, the nose is adjacent to the abutting groove, and is used to press against the to-be-formed part when the abutting groove pushes the end surface of the side wall of the to-be-formed part pieces.

In one embodiment, the pushing block pushes against the side wall, so that at least a part of the material of the first arc and/or the side wall is plastically deformed to fill the space formed by the lower mold and the pushing block.

In one embodiment, the pushing block pushes against the side wall, so that at least part of the material of the first arc and/or the side wall undergoes plastic deformation, and sticks to the lower mold.

In one embodiment, the pushing block has a relief groove for accommodating a corresponding pin of the object to be formed, so as to prevent the pin from being damaged when the pushing block pushes against the side wall of the object to be formed.

The shell forming method of the present invention is to push the side wall of the workpiece to be formed by pushing the push block of a forming mold, and form arc angles and sharp angles in the form of local material plastic deformation Features, which have the following effects: the ratio of the radius of the arc corner of the shell to the thickness of the part to be formed can be close to 1, and the sharp corners show a sense of sharpness, which is in line with the current market trend of 3C shells; through the plastic deformation of local materials The material filling effect can prevent the material thickness at the arc corner from becoming thin and cracked, and improve the production yield; it can make the thickness of the arc corner of the shell part uniform, improve the rigidity of the shell part, and help the shell part to be lighter and thinner; and can ensure Dimensional accuracy at the arc corner of the shell.

10: Plate

11: First arc angle

12: Bottom

13: side wall

131: end face

14: The second arc angle

141: Outward convex sharp corner

15: Pin

20,20': Mold

21,21': Punch

22,22': Lower mold

23: side module

24,24': pushing block

241': abutting groove

242': Nose

243: let slot

25,25': mold cavity

251,251': concave sharp corner

30: shell

31: bottom

32: side wall

33: arc angle

34: Outward convex sharp corner

40: shell embryo

41: corner

42: bottom

43: side wall

44: First arc angle

45: bottom

46: side wall

461: end face

47: second arc angle

471: Outward convex sharp corner

R ₁ : Radius of the first arc angle

R ₂ : Radius of the second arc angle

S10: Steps of providing parts to be formed and molds

S20: Forming the first arc angle step

S30: Forming the second arc angle and sharp angle step

t ₁ : Thickness of the plate

t ₂ : Sheet thickness of shell blank

Fig. 1 is a flow chart of the steps of an embodiment of the shell forming method of the present invention.

2A to 2D are schematic cross-sectional views of a plate being formed by a mold through the shell forming method of the present invention.

Fig. 3 is a three-dimensional cross-sectional schematic view of a shell formed by the shell forming method of the present invention.

4A to 4C are schematic cross-sectional views of a shell blank formed by a shell forming method of the present invention with a mold.

5A to 5D are schematic cross-sectional views of a plate formed by another mold through the shell forming method of the present invention.

FIG. 6 is a schematic diagram of forming a shell with pins by a forming die of the present invention.

Fig. 7 is a side view of the forming mold of the present invention forming a shell with pins.

In order to make the above or other purposes, features and characteristics of the present invention more obvious and easy to understand, the relevant embodiments of the present invention are described in detail below in conjunction with the drawings. Therefore, only the elements related to the present invention are marked in the drawings, and the drawn elements are not drawn in the number, size ratio, etc. during implementation, and the layout of the elements may be more complicated.

The directional terms mentioned in the description of the present invention, such as "upper", "lower", "front", "rear", "left", "right", "inside", "outside", "side", etc., are only Refer to the drawing for directions. The directional terms used are only used to illustrate and understand the present invention, but not to limit the present invention.

Fig. 1 is a flow chart of the steps of the first embodiment of the shell forming method of the present invention, and Figs. 2A-2D are schematic cross-sectional views of a plate formed by a shell forming method of the present invention with a mold. Please refer to FIG. 1 and FIG. 2A~2C together. The steps of the shell forming method of this embodiment include: providing the workpiece to be formed and the mold step S10; forming the first arc angle step S20; and forming the second arc angle and sharp corner Step S30.

In the step S10 of providing the object to be formed and the mold, the object to be formed is a plate 10 (please refer to FIG. 2A ). In one embodiment, the plate material 10 can be a metal plate, and its material can be iron metal, aluminum metal, magnesium metal, titanium metal and so on. In another embodiment, the board 10 can be a fiber metal laminate (Fiber metal laminate, FML), which uses an adhesive to glue two or more layers of metal plates and fiber layers sandwiched between the metal plates. In addition, the fiber metal laminate can further include a circuit layer, an antenna layer, a coil layer, a chip layer, or a combination of the aforementioned layers between the metal plates. In other applications, the board 10 can be a thermoplastic composite board. In order to enable the subsequent forming steps to proceed smoothly, and there is no need to cut off the remaining material after forming, the shape of the plate 10 is obtained through analysis and experiments.

In the step S10 of providing the workpiece to be formed and the mold, the provided mold 20 includes a punch 21 , a lower mold 22 , a side module 23 and a pusher block 24 . The lower mold 22 and the side module 23 are assembled to form a mold cavity 25 of the mold 20 , and the mold cavity 25 is located at the adjacent part of the lower mold 22 and the side module 23 to form a concave sharp corner 251 . The pushing block 24 is arranged adjacent to the punch 21, and moves in the same direction, and can be driven separately.

R₁

3t₁，其中R₁為第一弧角11的半徑，t₁為板材10的厚度。較佳地，在製品的側壁13的一端面131是位於側模塊23的一上表面231下方。 In forming the first arc angle step S20, the plate 10 is press-formed by the mold 20, so that the plate 10 forms a first arc angle 11, one end of the first arc angle 11 is connected to a bottom 12, and the other end is connected to a side wall 13 (please refer to the figure 2B). When the die 20 executes the stamping stroke, the punch 21 first moves toward the lower die 22, and the plate 10 is pushed by the punch 21 into the mold cavity 25, and is squeezed by the punch 21 in the mold cavity 25 to gradually deform into a "U" shape. The product in process (semi-finished product) of " shape section, and form the first arc angle 11 at the adjoining place of lower mold 22 and side module 23. The first arc angle 11 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the first arc angle 11 and the thickness of the plate 10: 2t ₁

R ₁

3t ₁ , where R ₁ is the radius of the first arc 11 , and t ₁ is the thickness of the plate 10 . Preferably, an end surface 131 of the side wall 13 of the product is located below an upper surface 231 of the side module 23 .

The cutting shape of the sheet material 10 is determined through analysis and experimentation. After the first arc forming step S20, a product in process with the same height as the side wall 13 and no remaining material can be obtained, which enables the subsequent forming steps to proceed smoothly.

In order to make the stamping process of some plates 10 (such as magnesium alloy or titanium alloy plates, thermoplastic composite plates) go smoothly, the mold 20 further includes a heating module (not shown) for heating or maintaining the temperature of the plates 10 .

R₂

2t₁，其中R₂為第二弧角14的半徑，t₁為板材10的厚度。 Please refer to FIG. 2C , in the step S30 of forming the second arc and sharp corners, the punch 21 continues to press against the bottom 12 of the product to fix the product and keep the bottom 12 of the product flat. Then the pusher block 24 moves toward the side module 23 (i.e. downward). When the pusher block 24 contacts the side module 23, the side module 23 then moves down with the pusher block 24. When the end face 131 of the side wall 13 of the product is at the same height, the pushing block 24 touches and then pushes the end face 131 of the side wall 13. During the process of pushing the side wall 13, the first arc angle constrained by the punch 21 and the mold cavity 25 11 and/or at least part of the material of the side wall 13 is plastically deformed to fill the space (including the concave sharp corner 251) formed by the punch 21, the lower mold 22 and the side module 23, so that the first The arc angle 11 is reshaped into a second arc angle 14, and an outer convex corner 141 is formed at the adjacent part of the second arc corner 14 and the side wall 13, and the outer convex corner 141 is correspondingly located at the adjacent part of the lower mold 22 and the side module 23 The concave sharp corner 251 of. The second arc angle 14 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the second arc angle 14 and the thickness of the plate 10: t ₁

R ₂

2t ₁ , where R ₂ is the radius of the second arc 14 , and t ₁ is the thickness of the plate 10 .

In another embodiment, under different mold design parameters, in the process of pushing the push block 24 against the side wall 13, at least The local material is plastically deformed, and moves to the space (including the concave sharp corner 251) formed by the punch 21, the lower die 22, and the side module 23, and sticks to the lower die 22 and the side module 23, so that the finished product The first arc angle 11 is reshaped into the second arc angle 14, and an outer convex corner 141 is formed at the adjoining position of the second arc angle 14 and the side wall 13, as shown in FIG. 2D.

When forming the first arc angle step S20, the plate 10 is pressurized by the punch 21 and the lower die 22 to form the first arc angle 11, and the side of the material at the first arc angle 11 that is close to the mold cavity is subjected to considerable stress due to bending. Tensile stress can easily cause the thickness of the material at the first arc angle 11 to become thinner, or even rupture. In the step S30 of forming the second arc angle and the sharp corner, the pushing block 24 pushes the end surface 131 of the side wall 13 to form plastic deformation of the material and can have a feeding effect on the first arc angle 11, which can avoid the first arc angle In 11 places, the thickness of the material was thinned or broken due to severe bending. The implementation of the present invention is not limited to the step S20 of forming the first arc angle, and then performing the step S30 of forming the second arc angle and the sharp corner. The execution of the two steps is allowed to overlap in time, and the operator can shape according to the shell The situation selects the appropriate step execution sequence.

The shell forming method of the present invention pushes the side wall 13 of the product in process by the pusher block 24 of the forming mold 20, and forms the second arc angle 14 and the outwardly convex sharp angle 141 in a manner of plastic deformation of the material. The second arc angle The ratio of the radius at 14 to the thickness of the part to be formed can be close to 1, and the convex corner 141 shows a sharp feeling, which is in line with the current trend of 3C shell parts; it can avoid the material thickness at 14 of the second arc angle from becoming thin and cracking , improve production yield; can make the thickness of the second arc angle 14 uniform, improve the overall rigidity of the shell, and help the shell to be thinner; and can ensure the dimensional accuracy of the second arc angle 14.

Fig. 3 is a three-dimensional cross-sectional schematic view of a shell formed by the shell forming method of the present invention. According to the above steps, the plate 10 can be processed into a shell 30. The shell 30 has a bottom 31, a side wall 32, and an arc 33 connecting the bottom 31 and the side wall 32, and the arc 33 is adjacent to the side wall 32. There is a convex corner 34 on the outer surface. The bottom 31 of the shell 30 shown in FIG. 3 is arc-shaped, but the implementation of the present invention is not limited thereto, and the bottom of the shell can also be flat.

In the case formed by the shell forming method disclosed in the above embodiments, the outer convex corner is located at the adjacent part of the arc corner and the side wall, but the implementation of the present invention is not limited thereto, and the outer convex corner can be located on the arc At the corner, or at the abutment of the arc corner and the bottom.

4A to 4C are schematic cross-sectional views of a shell blank formed by a shell forming method of the present invention with a mold. In the embodiment disclosed in Fig. 4A ~ 4C, the to-be-formed part provided by the step S10 of the mold to be formed is a shell blank 40 (please refer to Fig. 4A), which includes a corner 41, the corner 41 One end of the angle 41 is connected to a bottom 42 , and the other end of the angle 41 is connected to a side wall 43 . The corner 41 can be a bevel or a third arc angle, and the corner 41 shown in FIG. 4A is a bevel. The forming step of the shell blank 40 includes: providing a plate, preforming and cutting off the remaining material. The preforming step uses a blank mold (not shown) to form the corner 41 . The steps of forming the shell blank 40 should be known to those skilled in the art, and will not be described in detail here.

Similarly, the sheet material forming the shell blank 40 can be a metal sheet, and its material can be iron metal, aluminum metal, magnesium metal, titanium metal, etc. FIG. In another embodiment, the sheet material is a fiber metal laminate. In addition, the fiber metal laminate can further sandwich a circuit layer, an antenna layer, a coil layer, a chip layer, or the aforementioned A combination of layers. In other applications, the sheet material forming the shell blank 40 may be a thermoplastic composite sheet.

R₁

3t₂，其中R₁為第一弧角44的半徑，t₂為殼件初胚40的板料厚度。較佳地，在製品的側壁46的一端面461是低於側模塊23的上表面231。 In forming the first arc angle step S20, the shell blank 40 is press-molded by the mold 20, so that the shell blank 40 forms a first arc angle 44, one end of the first arc angle 44 is connected to a bottom 45, and the other end is connected to a The side wall 46 (please refer to FIG. 4B ). When the mold 20 executes the stamping stroke, the punch 21 first moves toward the lower die 22, and the shell blank 40 is squeezed by the punch 21 in the mold cavity 25 and gradually deformed into a product in process with a "U"-shaped cross section, and A first arc 44 is formed at the adjacent part of the lower mold 22 and the side module 23 . The first arc angle 44 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the first arc angle 44 and the sheet material thickness of the shell blank 40: 2t ₂

R ₁

3t ₂ , wherein R ₁ is the radius of the first arc angle 44, and t ₂ is the sheet thickness of the shell blank 40. Preferably, an end surface 461 of the side wall 46 of the product is lower than the upper surface 231 of the side module 23 .

R₂

2t₂，其中R₂為第二弧角47的半徑，t₂為殼件初胚40的板料的厚度。 Please refer to FIG. 4C, in forming the second arc angle and sharp corner step S30, the punch 21 continues to press against the bottom 45 of the product to fix the product and keep the bottom 45 of the product flat, and then the push block 24 moves forward The side module 23 moves in the direction (i.e. downward), and when the pushing block 24 contacts the side module 23, the side module 23 then moves down with the pushing block 24, and when the upper surface 231 of the side module 23 and the side wall 46 of the product in progress When the end face 461 is at the same height, the pushing block 24 touches and then pushes the end face 461 of the side wall 46. During the process of pushing the side wall 46, the first arc angle 44 and/or the side wall 46 constrained by the punch 21 and the mold cavity 25 Plastic deformation of at least part of the material to fill the space formed by the punch 21, the lower die 22 and the side module 23, so that the first arc angle 44 of the product is shaped into a second arc angle 47, and then The adjacent part of the second arc 47 and the side wall 46 forms an outwardly convex sharp corner 471 , and the outwardly convex sharp corner 471 is corresponding to the inner concave sharp corner 251 located at the adjacent part of the lower mold 22 and the side module 23 . The second arc angle 47 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the second arc angle 47 and the thickness of the sheet material of the shell blank 40: t ₂

R ₂

2t ₂ , where R ₂ is the radius of the second arc angle 47 , and t ₂ is the thickness of the blank 40 of the shell.

Similarly, according to the above steps, the shell blank 40 can be processed into a shell 30 as shown in Figure 3, which has a bottom 31, a side wall 32, and an arc 33 connecting the bottom 31 and the side wall 32, and On the outer side of the adjoining part of the arc corner 33 and the side wall 32 there is an outwardly protruding sharp corner 34 .

5A-5D are schematic cross-sectional views of a plate formed by another mold through the shell forming method of the present invention. Please refer to Fig. 1 and Fig. 5A ~ 5C together. In the step S10 of providing the part to be formed and the mold, the part to be formed in this embodiment is explained with a plate 10. Those who are familiar with the common knowledge in the technical field should be able to pass this The content previously disclosed in the specification is applied to the implementation of the shell blank. The type and material of the plate or shell blank are the same as those disclosed in the foregoing embodiments, and will not be repeated here.

In the step S10 of providing the workpiece to be formed and the mold, the provided mold 20' includes a punch 21', a lower die 22' and a pushing block 24' (please refer to FIG. 5A). A mold cavity 25' is formed in the lower mold 22', which has a concave sharp corner 251'. Pushing block 24' is arranged adjacent to punch 21', and travels in the same direction, and can be driven separately. A corner of the pushing block 24' close to the mold cavity 25' and facing the inner wall of the mold cavity 25' defines a resisting groove 241', and adjacent to the resisting groove 241' is a nose 242'.

R₁

4t₁，其中R₁為第一弧角11的半徑，t₁為板材10的厚度。較佳地，在製品的側壁13的一端面131是低於下模22’的上表面。 In the step S20 of forming the first corner, the plate 10 is press-formed by the mold 20 ′, so that the plate 10 forms a first corner 11, one end of the first corner 11 is connected to a bottom 12, and the other end is connected to a side wall 13 (please refer to Figure 5B). When the die 20' performs the stamping stroke, the punch 21' first moves toward the lower die 22', and the punch 21' pushes the plate 10 into the mold cavity 25', and is squeezed by the punch 21' in the mold cavity 25' and gradually becomes A work-in-progress (semi-finished product) having a "U"-shaped cross-section is formed, and a first arc 11 is formed adjacent to the concave sharp corner 251' of the lower mold 22'. The first arc angle 11 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the first arc angle 11 and the thickness of the plate 10: 2t ₁

R ₁

4t ₁ , where R ₁ is the radius of the first arc 11 , and t ₁ is the thickness of the plate 10 . Preferably, one end surface 131 of the side wall 13 of the product is lower than the upper surface of the lower mold 22'.

Similarly, the mold 20 may further include a heating module (not shown) to heat or maintain the temperature of the plate 10, so that the stamping process of part of the plate 10 (such as magnesium alloy or titanium alloy plate, thermoplastic composite plate) can be carried out smoothly. .

R₂

2t₁，其中R₂為第二弧角14的半徑，t₁為板材10的厚度。 Please refer to FIG. 5C, in forming the second arc angle and sharp corner step S30, the punch 21' continues to press against the bottom 12 of the product to fix the product and keep the bottom 12 of the product flat, and then the push block 24 'Moving in the direction of the lower die 22' (that is, downward), when the abutting groove 241' of the pushing block 24' touches the end surface 131 of the side wall 13, it begins to push the side wall 13, while the nose 242' presses against the first One arc 11, or the abutment of the first arc 11 and the bottom 12, depends on the design of the pusher block 24'. In the process that the sidewall 13 is pushed, at least part of the material of the first arc angle 11 and/or sidewall 13 constrained by the pushing block 24' and the mold cavity 25' is plastically deformed, and the lower mold 22' and the pushing part are filled. The space formed by the material block 24' (including the concave sharp corner 251') shapes the first arc corner 11 of the product into a second arc corner 14, and is formed at the adjoining place between the second arc corner 14 and the side wall 13 An outer convex corner 141, the outer convex corner 141 is corresponding to the inner concave corner 251' of the lower mold 22'. The second arc angle 14 is defined by at least one radius. In one embodiment, the following relationship exists between the radius of the second arc angle 14 and the thickness of the plate 10: t ₁

R ₂

2t ₁ , where R ₂ is the radius of the second arc 14 , and t ₁ is the thickness of the plate 10 .

In another embodiment, under different mold design parameters, in the process of pushing the push block 24' against the side wall 13, the first arc angle 11 and/or restricted by the push block 24' and the cavity 25' At least part of the material of the side wall 13 produces plastic deformation, and moves to the space (including the concave sharp corner 251 ') formed by the lower mold 22' and the pushing block 24', and sticks to the lower mold 22', and the first One arc angle 11 is shaped into a second arc angle 14 , and an outer convex corner 141 is formed at the adjoining portion of the second arc angle 14 and the side wall 13 , as shown in FIG. 5D .

In the step S30 of forming the second arc and sharp corners, if the sheet material 10 is of a material that is not easy to form, a heating module (not shown) can be specially installed near the concave sharp corner 251' of the lower die 22' to heat the second arc and sharp corners. The material at an arc angle 11 makes the plastic deformation of the material at this place proceed smoothly.

Fig. 6 and Fig. 7 are schematic diagrams of forming a shell with pins by the shell forming mold of the present invention. In one application scenario, the side wall of the shell has a connection required for the subsequent process. Pins, such as conductive pins required for anodizing, please refer to FIGS. 6 and 7 , the pins 15 extend from the end surface 131 of the side wall 13 along the direction of the side wall 13 . In order to successfully press the pusher block 24 against the end face 131 of the side wall 13 to complete the forming step S30 of the second arc and sharp corner, the pusher block 24 is provided with a relief groove 243 at the position corresponding to the pin 15, so that the groove 243 can accommodate Set its corresponding pin 15 so that the pin 15 will not be damaged when the pushing block 24 pushes against the side wall 13 . The grooves shown in Figures 6 and 7 are implemented on the molds shown in Figures 2A to 2C, but not limited thereto, and those skilled in the art should be able to refer to the explanations in this paragraph and Figures 6 and 7 FIG. 7, it is implemented on the mold shown in FIGS. 5A-5C.

The shell forming method of the present invention uses a forming die to pressurize a piece to be formed, and pushes the side wall of the piece to be formed with its pusher block, forming arc angles and sharp corners in a manner of local material plastic deformation, and can be formed. Metal shells with sharp angles; local material plastic deformation forms a filling effect, which can avoid material breakage at the arc corners due to severe bending, and improve production yield; can make the thickness of the arc corners of the shell parts uniform, and improve the rigidity of the shell parts; And it can ensure the dimensional accuracy of the arc corner of the shell.

The above descriptions are only the preferred implementation modes or examples of the technical means adopted by the present invention to solve the problems, and are not intended to limit the scope of the patented implementation of the present invention. That is, all equivalent changes and modifications that are consistent with the scope of the patent application of the present invention, or made according to the scope of the patent of the present invention, are covered by the scope of the patent of the present invention.

10: Plate

20: Mold

21: Punch

22: Lower mold

23: side module

24: push block

25: Mold cavity

251: concave sharp corner

Claims (10)

A shell forming die is used to form a workpiece to be formed into a shell with a protruding sharp corner, the shell forming die includes: a cavity having a concave cusp corresponding to the convex cusp of the shell; a punch for extruding the to-be-formed part so that the to-be-formed part is deformed in the mold cavity to have a first arc and a side wall connected to one end of the first arc; and A pushing block is arranged adjacent to the punch, and its moving direction is the same as that of the punch, and is used to push an end surface of the side wall, so that the punch and the cavity or the pushing block and the die The first arc angle constrained by the cavity and/or at least part of the material of the side wall is plastically deformed to fill the concave corner, form the outer convex corner of the shell, and at the same time form a second arc corner, the The second arc corner is adjacent to the convex sharp corner. The shell forming mold according to claim 1, wherein the mold cavity is formed by a lower mold and a side module, and the concave sharp corner is located at the adjacent part of the lower mold and the side module. The shell forming mold as described in claim 2, wherein when the pushing block moves to contact the side module, the side module can move with the pushing block, and when the upper surface of the side module is in contact with the part to be formed When the end faces of the side walls are at the same height, the pushing block touches and then pushes the end faces of the side walls. The shell forming mold according to claim 3, wherein the pushing block pushes the side wall, causing plastic deformation of at least part of the first arc angle and/or the side wall, and filling the punch, the lower mold and the space formed by the side modules. The shell forming mold as claimed in item 3, wherein the pusher block pushes the side wall, so that at least part of the material of the first arc and/or the side wall is plastically deformed, and sticks to the lower mold and the side module. The shell forming mold as described in claim 1, wherein the mold cavity is located in the lower mold, and a corner of the pushing block close to the mold cavity and facing the inner wall of the mold cavity is provided with an abutment groove, and the abutment groove It is used to push the end face of the side wall of the workpiece to be formed. The shell forming mold as claimed in item 6, wherein the pushing block has a nose, and the nose is adjacent to the abutting groove, and is used to push the end surface of the side wall of the object to be formed in the abutting groove , press against the workpiece to be formed. The shell forming die as claimed in item 6, wherein the pushing block pushes the side wall, causing plastic deformation of at least part of the first arc angle and/or the side wall, and filling the lower die and the pushing The space formed by the block. The shell forming mold according to claim 6, wherein the pushing block pushes the side wall, causing plastic deformation of at least a part of the first arc angle and/or the material of the side wall, and adhering to the lower mold. The shell forming mold as described in Claim 1, wherein the push block has a groove for accommodating a pin of the corresponding part to be formed, so as to prevent the push block from pushing against the part to be formed damage the pin when touching the side wall.

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