Knowledge of structural design of sheet metal parts (VII): Dimensional tolerance of sheet metal parts

Knowledge of structural design of sheet metal parts (VII): Dimensional tolerance of sheet metal parts

Tolerance is one of the important factors affecting product quality and price. When manufacturing parts, experience tells us that no matter how much cost and time are invested, it is almost impossible to accurately process them according to the dimensions marked on the drawing. Product design should meet the needs of users in terms of performance and economy. From the enterprise itself, it must also maintain normal profits. Therefore, the tolerance must be determined by the performance and economy of the product. Therefore, the design should fully grasp the principle of tolerance.  (1) dimensional tolerance of punching parts. (2) side…
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Knowledge of structural design of sheet metal parts (VI): Configuration criteria of common screw bottom holes of sheet metal parts

Knowledge of structural design of sheet metal parts (VI): Configuration criteria of common screw bottom holes of sheet metal parts

1. Hole flanging There are many types of hole flanging. This criterion only focuses on the inner hole flanging of the thread to be processed, as shown in the figure. (the diameter and flanging height of the bottom hole and flanging hole of uterine screw are commonly used in sheet metal parts) 2. Through holes and countersunk seats for screws and bolts The structural dimensions of screw, bolt through hole and countersunk seat are selected in the following table. For the countersunk seat of countersunk screw, if the plate is too thin to ensure through hole D2 and countersunk hole…
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Knowledge of structural design of sheet metal parts (V): Reasonable configuration criteria for improving part strength

Knowledge of structural design of sheet metal parts (V): Reasonable configuration criteria for improving part strength

1. In order to improve the strength of long sheet metal parts, reinforcement bars should be designed. 2. Bending at the corner of the bending part can strengthen the rib. 3. Stiffener Pressing ribs on plate-shaped metal parts helps to increase the structural rigidity. See the table for the structure and size selection of stiffeners. 4. Limit dimensions of convex spacing and convex edge spacing The limit dimensions of convex spacing and convex edge spacing are selected in the following table.
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Knowledge of structural design of sheet metal parts (IV): Configuration criteria of stretched parts

Knowledge of structural design of sheet metal parts (IV): Configuration criteria of stretched parts

Configuration criterion of deep drawing parts a. The shape of drawing parts shall be as simple and symmetrical as possible. b. The size proportion of each part of the drawing part shall be appropriate, and the drawing parts with wide flange and large depth shall be avoided as far as possible. (d convex > 3D, H ≥ 2D) because such parts need more drawing times. c. The fillet radius of deep drawing parts shall be appropriate, and the fillet radius shall be larger as far as possible, so as to facilitate forming and reduce the number of deep drawing.  (1)…
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Structural design knowledge of sheet metal parts(III): Structural criteria for bending parts

Structural design knowledge of sheet metal parts(III): Structural criteria for bending parts

1. Minimum bending radius of plate When the material is bent, on the fillet area, the outer layer is stretched and the inner layer is compressed. When the material thickness is constant, the smaller the inner radius R is, the more serious the tension and compression of the material are; When the tensile stress of the outer fillet exceeds the ultimate strength of the material, cracks and fractures will occur. Therefore, too small bending fillet radius should be avoided in the structural design of bending parts. The minimum bending radius is specified for this purpose. L bending radius refers to…
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Structural design knowledge of sheet metal parts(II): Structural design criteria

Structural design knowledge of sheet metal parts(II): Structural design criteria

When designing product parts, the problem of easy manufacture must be considered. Try to think of some methods, which can not only make processing easy, but also save materials, increase strength and avoid waste products. Therefore, designers should pay attention to the following manufacturing matters. The manufacturability of sheet metal parts refers to the difficulty of parts in punching, bending and stretching. Good technology should ensure less material consumption, less number of processes, simple die structure, high service life and stable product quality. In general, the biggest impact on the manufacturability of sheet metal parts is the performance of materials,…
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Knowledge of structural design of sheet metal parts (I): Introduction

Knowledge of structural design of sheet metal parts (I): Introduction

Opening Preface: Sheet metal (metal plate;; sheetmetal), a processing technology, has not yet had a relatively complete definition of sheet metal. According to a definition in a foreign professional journal, it can be defined as: sheet metal is a comprehensive cold working process for sheet metal (usually less than 6mm), including shearing, punching / cutting / compounding, folding, riveting, splicing, forming (such as automobile body), etc. Its remarkable feature is that the thickness of the same part is the same. Sheet metal has the characteristics of light weight, high strength, conductivity (which can be used for electromagnetic shielding), low cost…
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Is that true? Japan just pressed it, and the whole world was silent in six seconds

Is that true? Japan just pressed it, and the whole world was silent in six seconds

Some time ago, there was an article on wechat that "Japan will silence the whole world in six seconds with such a gentle press" and burst the circle of friends. In the article, a short video was sent to put the two iron blocks together. With a gentle press of your finger, they were tightly combined The video made people marvel at the seamless cooperation of the two parts. The article introduced that such technology came from a Japanese township enterprise with only 18 employees, boasting that this Japanese mold factory is an exclusive precision technology, and it is unclear…
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In simple terms, understand the reducer, the core component of industrial robot

In simple terms, understand the reducer, the core component of industrial robot

The reducer, the core component of industrial robot, is the core of mechanical transmission. The speed and accuracy of robot are related to the reducer. The reducer used by industrial robot mainly includes harmonic reducer and RV Reducer. 1、 Harmonic reducer 1. The motor shaft is connected to the wave generator, and the manipulator is connected to the hard base of the flexible gear ring 2. The flexible gear ring has n gear positions less than the rigid gear ring 3. The wave generator rotates once, and the flexible gear ring moves n gear positions 4. High deceleration ratio can…
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In addition to turning, milling, grinding and drilling, what new technologies are there in machining?

In addition to turning, milling, grinding and drilling, what new technologies are there in machining?

With the development of science and technology, machining technology is no longer limited to turning, milling, grinding and drilling, and more processing technologies have emerged, which meet the functions of product production and manufacturing and make up for the shortcomings of traditional processing; Now let's learn about these new machining processes! 1、 Metal injection molding (MIM) 1. Introduction: metal injection molding (MIM) is a near net shape forming process suitable for producing small, three-dimensional complex shapes and products with special performance requirements. This technology is a new near net shape forming technology of powder metallurgy, which introduces modern plastic injection…
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