阅读说明：本技术 一种笔记本壳体窄台阶成型方法 (Method for forming narrow steps of notebook shell ) 是由 张燕 于 2021-07-12 设计创作，主要内容包括：本发明属于金属冲压加工技术领域,涉及一种笔记本壳体窄台阶成型方法,步骤包括：打凸、拉伸、回挤和翻边。本发明能够成型台阶很窄的笔记本壳体,避免了产品大面积变形和翘曲问题,即使得到了尖转角也不会出现开裂。(The invention belongs to the technical field of metal stamping and processing, and relates to a method for forming a narrow step of a notebook computer shell, which comprises the following steps: and (4) carrying out embossing, stretching, back extrusion and flanging. The notebook shell with narrow steps can be formed, the problems of large-area deformation and warping of products are solved, and cracking cannot occur even if a sharp corner is obtained.)

1. A narrow step forming method for a notebook computer shell is characterized by comprising the following steps:

firstly, embossing: taking the flat surface of the material sheet as a base surface, punching a convex hull structure upwards, wherein the height from the upper surface of the convex hull structure to the base surface is lower than the expected height of the boss, and the edge of the convex hull structure is in a smooth transition structure with uniform thickness;

stretching: further stretching the convex hull structure to the height of a prospective boss, and meanwhile, enabling the transition region of the boss to the base surface to be in a structure with a thick upper part and a thin lower part, wherein the outer side of the boss is vertical;

③ extruding again: extruding the upper part of the transition region, forming a back extrusion structure on the inner side of the lower edge of the boss, and allowing the material on the lower part of the boss to flow upwards to form a sharp angle on the edge of the boss;

fourthly, flanging: and bending the outer side area of the boss downwards to form the edge of the notebook shell.

2. The narrow step molding method of notebook computer case according to claim 1, characterized in that: and the height of the convex hull structure obtained in the step of embossing is 1/2-2/3 of the height of the boss.

3. The narrow step molding method of notebook computer case according to claim 1, characterized in that: the back extrusion structure is composed of a plurality of shape-returning grooves which are equal in height and distributed at intervals.

4. The narrow step molding method of notebook computer case according to claim 3, characterized in that: the depth of the return groove is 1/10-1/5 of the thickness of the material.

5. The narrow step molding method of notebook computer case according to claim 1, characterized in that: and (d) forming an arched flanging pre-folding part on the edge of the material while punching the convex hull structure, and deforming the material outside the flanging pre-folding part into the folded edge.

Technical Field

The invention relates to the technical field of metal stamping, in particular to a method for forming a narrow step of a notebook shell.

Background

In recent years, the development of the domestic mold industry faces a plurality of dilemmas, the profitability of enterprises generally declines due to the increase of labor cost, the enterprises face a transformation period, and large, precise, complex and efficient molds with long service life are brought up with a new step along with the development of the mold technology in China. In recent years, a 3C product mold mainly for a notebook computer is taken as a representative, and in order to match the existing 5G technology and the aesthetic sense of people, a novel three-dimensional appearance of the product is considered while meeting the performance.

As shown in fig. 1 and 2, the edge of a boss 11 of a notebook computer shell with a keyboard surface at present has a narrow step 12, and the forming difficulty is that the width of the narrow step is almost equal to the thickness of a material, and the edge of the boss 11 has a sharp corner 111 with a small chamfer angle. The inner and outer side materials are too sharply turned by adopting a common stamping method, and are easy to break, and the shape of a sharp corner cannot be full.

For this reason, a new molding method has been developed to solve the above problems.

Disclosure of Invention

The invention mainly aims to provide a method for forming a narrow step structure of a notebook computer shell, which can ensure the forming precision of the narrow step structure on the notebook computer shell.

The invention realizes the purpose through the following technical scheme: a method for forming narrow steps of a notebook shell comprises the following steps:

firstly, embossing: taking the flat surface of the material sheet as a base surface, punching a convex hull structure upwards, wherein the height from the upper surface of the convex hull structure to the base surface is lower than the expected height of the boss, and the edge of the convex hull structure is in a smooth transition structure with uniform thickness;

stretching: further stretching the convex hull structure to the height of a prospective boss, and meanwhile, enabling the transition region of the boss to the base surface to be in a structure with a thick upper part and a thin lower part, wherein the outer side of the boss is vertical;

③ extruding again: extruding the upper part of the transition region, forming a back extrusion structure on the inner side of the lower edge of the boss, and allowing the material on the lower part of the boss to flow upwards to form a sharp angle on the edge of the boss;

fourthly, flanging: and bending the outer side area of the boss downwards to form a folded edge of the notebook shell.

Specifically, the height of the convex hull structure obtained in the step of embossing is 1/2-2/3 of the height of the boss.

Specifically, the back extrusion structure is composed of a plurality of shape grooves which are equal in height and distributed at intervals.

Furthermore, the depth of the return groove is 1/10-1/5 of the material thickness.

Specifically, the convex hull structure is punched out, meanwhile, an arched flanging pre-folding part is formed at the edge of the material, and the material outside the flanging pre-folding part is deformed into the folded edge.

The technical scheme of the invention has the beneficial effects that:

the notebook shell with narrow steps can be formed, the problems of large-area deformation and warping of products are solved, and cracking cannot occur even if a sharp corner is obtained.

Drawings

FIG. 1 is a perspective view of a notebook housing;

FIG. 2 is an enlarged view of a portion of the portion A of FIG. 1;

FIG. 3 is a diagram of material variation in narrow step position;

fig. 4 is an enlarged partial view of the location of the swage ring of the back extrusion punch.

The figures in the drawings represent:

1-notebook shell, 11-convex hull structure, 11' -boss, 111-sharp corner, 112-back extrusion structure, 12-narrow step, 13-folded edge, 131-folded edge pre-folding part;

2-back extrusion punch and 21-material pressing ring.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

Example (b):

as shown in fig. 1 to 3, the method for forming a narrow step of a notebook computer shell according to the present invention includes the steps of:

taking a flat material sheet surface as a base surface, upwards punching a convex hull structure 11, wherein the height from the upper surface of the convex hull structure 11 to the base surface is lower than the height of an expected boss 11', and the edge of the convex hull structure 11 is in a smooth transition structure with uniform thickness;

secondly, further stretching the convex hull structure 11 to the height of an expected boss 11 ', and meanwhile, enabling a transition region from the boss 11 ' to a base surface to be of a structure with a thick upper part and a thin lower part, wherein the outer side of the boss 11 ' is vertical;

thirdly, extruding the upper part of the transition area to be thin, and forming a back extrusion structure 14 on the inner side of the lower edge of the boss 11 ', so that the material on the lower part of the boss 11 ' flows upwards, and the edge of the boss 11 ' forms a sharp angle;

and fourthly, bending the outer side area of the boss 11' downwards to form a folded edge 13 of the notebook shell.

As shown in FIG. 3, the height of the convex hull structure 11 obtained in the convex forming step is 1/2-2/3 of the height of the boss 11'. The boss 11' is transited by the lower convex hull structure 11, so that the problem of breaking caused by too much stretching at one time can be avoided.

As shown in fig. 3 and 4, the backward extrusion structure 112 is composed of a plurality of equal-height and spaced-apart circular grooves. The back extrusion punch 2 on the die has a plurality of material pressing rings 21 with a shape-returning structure for extruding a back-forming groove, and the defect of the position of the back-forming groove can cause the material to move to the vacant position of the die cavity, so that the sharp corner 111 can be full.

The depth of the return groove is 1/10-1/5 of the material thickness. This avoids the material being too thin and affecting strength.

As shown in fig. 3, the convex hull structure 11 is punched out, and at the same time, an arched flanging pre-folding part 131 is formed at the edge of the material, and the material outside the flanging pre-folding part 131 is deformed into the folded edge 13. The flanging pre-folding part 131 can lead the material to release stress in advance, so that the flanging pre-folding part 13 and the convex hull structure 11 can be molded simultaneously to prevent the direct flanging from leading the material to be pulled to the edge to cause the deformation of the boss 11'.

What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.