preface

Sheet metal parts are widely used in automobile surface covering parts and internal structure parts. As a controller structural engineer, I always bear the pressure of cost reduction. After investigating various schemes, I found that peers have changed the controller cover into a successful case of sheet metal stamping parts. In order not to make low-level mistakes in the design process, I consulted the information and displayed the common skills of sheet metal parts design here, and reviewed them together with all my peers.

The body of the

Sheet metal processing mainly has four major processes: blanking, bending, stretching, forming. Each process has its own specification requirements for design, and we will briefly elaborate on them from these four aspects.

First, the blanking

Blanking is divided into ordinary blanking and precision blanking, due to the different processing methods, blanking parts of the processing technology is also different. The upper cover of motor controller and other structural parts are only used for general blanking. The following is only to introduce the structure of ordinary blanking we can use. Tip 1.1 The shape and size of the blanking parts should be as simple and symmetrical as possible, so as to minimize waste when arranging.

Layout of blanking parts

Tips 1.2 The shape and inner hole of blanking parts should avoid sharp corners. There should be an arc connection at the connection of a straight line or curve with radius R≥0.5t. (T is material wall thickness)

Punching parts should avoid long cantilever and slot punching parts of the convex or concave part of the depth and width, under normal circumstances, should not be less than 1.5T (t for thickness), and should avoid narrow long incision and too narrow groove, in order to increase the corresponding part of the cutting edge strength of the mold.

1.4 Circular holes are preferred for punching, and the minimum size of the hole is required. The minimum size of the hole is related to the shape of the hole, the mechanical properties of the material and the thickness of the material.

Image.png Example of punching shape

material

Round hole diameter B

Rectangular hole short side wide B

High carbon steel

1.3 t

1.0 t

Low carbon steel, brass

1.0 t

0.7 t

aluminum

0.8 t

0.5 t

* T is the material thickness, the minimum punching size is generally not less than 0.3mm

Technique 1.5 Punching hole spacing and hole margin. The minimum distance between the punching edge of a part and the shape of the part and the hole is limited to a certain extent, as shown in the figure below. When the edge of the punching hole is uneven with the outer edge of the part, the minimum distance should not be less than the material thickness T; When parallel, it should not be less than 1.5T.