Replaced by JB/T 7531-2005 JB/T 7531-1994 Design Specification for Spun Parts JB/T7531-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Design Specifications for Spinning PartswwW.bzxz.Net
1 Subject Content and Scope of Application
JB/T 7531 --- 94
This standard specifies the structural design principles and structural elements of metal spinning parts. This standard is used as the basis for spinning product designers to design spinning parts, and can also be used by spinning research and production personnel to formulate spinning processes. 2 Reference Standards
JB/T7532 Principles for Spinning Part Process Preparation
3 Terminology
3.1 Spinning
Spinning is a metal pressure processing method used to form thin-walled hollow rotating parts. It uses tools such as spinning wheels, rolling rods or balls to feed and apply pressure to the metal blank that rotates along the same axis as the spinning die, so that it produces continuous local plastic forming to form the required hollow rotating parts.
3.2 Ordinary spinning
The spinning method mainly changes the diameter of the blank to form the parts. The wall thickness is slightly thinned or thickened as the shape changes, and the distribution along the generatrix is ​​uneven.
3.3 Thinning spinning (powerful spinning)
During the spinning process, the blank wall thickness is thinned point by point and regularly under higher contact pressure without significant change in diameter. 3.4 Positive spinning
During the forming process, the flow direction of the deformed metal is alternate with the longitudinal feed direction of the spinning wheel. 3.5 Reverse spinning
During the forming process, the flow direction of the deformed metal is opposite to the longitudinal feed direction of the spinning wheel. 3.6 Sine law
When the conical part is thinned and spun, the basic law that the thickness change of the blank must follow is that at the same diameter, the workpiece thickness t is equal to the product of the plate thickness t and the sine value of the workpiece semi-cone angle α. 4 Classification of spun parts
4.1 Classification by shape of spun parts (see Figure 1): a.
Conical parts:
Simple parts (including those with bottom, without bottom and with steps on the inner and outer surfaces): Ellipsoidal parts;
Curved mother line parts (including two or more shapes combined). Approved by the Ministry of Machinery Industry of the People's Republic of China on October 25, 1994 and implemented on October 1, 1995
4.2 Classification by process
JB/T7531-94
Figure 1 Rotating body parts that can be spun
The forming process of pressed parts can be formed by one or several processing methods according to their process classification. Common examples are as follows: a.
Ordinary spinning preforming, thinned spinning ring-shaped products: thinned spinning preforming, ordinary spinning products; thinned spinning preforming, deep drawing products; deep drawing preforming, thinned spinning products: explosion preforming, thinned spinning products; thinned spinning preforming, explosion forming products; extrusion preforming, thinned spinning products; casting preforming, thinned spinning products; welding preforming, thinned spinning products. 5 Design specification of spun parts
General principles of spun parts structural design
Non-axisymmetric rotational parts cannot be spun; the shape of spun parts should be as simple as possible under the premise of meeting product needs; it should fully reflect economic rationality, that is, saving raw materials, reducing spinning processes, and reducing workpiece costs; it should consider the convenience of mold design and manufacturing required, and be conducive to improving the life of the mold; it should take into account the deformation characteristics of the spinning process and the changes in physical and mechanical properties caused by it; it should take into account the convenience and economy of rough preparation, which is conducive to metal deformation; JB/T 7531---94
products, and the factors affecting the heat treatment process during and after forming; h. All metal materials that can be cold or hot formed can be spun. Hot spinning process should generally be adopted for low plasticity and difficult to deform metals and some casting rough parts;
i, the convenience of loading and unloading of workpieces should be considered
5.2 Structural elements of spun parts
5.2.1 The wall thickness of spun parts
should try to adopt equal wall thickness structure. If it is a spun part with non-equal wall thickness, the wall thickness should decrease (or increase) in sequence. 5.2.2 The inner diameter of spun parts
should try to adopt equal inner diameter structure. If it is a spun part with non-equal inner diameter, its inner surface should avoid local inverted cone. 5.2.3 The transition of the spun part surface
should be smooth, and its fillet radius value should match the fillet radius of the spinning wheel used to process the product. 5.2.4 Steps of spun parts
The slope transition angles at both ends of the steps on the surface of spun parts should not be greater than 40°. 5.2.5 Inner Surface Fillet at the Bottom of Spinning Parts
For spin-formed parts, the inner surface bottom should be designed with a process fillet, and the R value should be 2 to 5 mm. 5.2.6 Shape Selection of Thinning Spinning Parts
For cone-shaped and ellipsoidal spin-formed parts formed by thinning spinning, the shape and size of the spin-formed parts should be selected according to the sine law. 5.3 Technical specifications for the structural design of spun parts
Select materials with good spinning performance (spinnability); see Table 1 of JB/T7532 for the limit thinning rate of commonly used materials; use the improvement of material performance after thinning spinning to reduce the weight of parts or use cheaper materials as a substitute; during thinning spinning, the bottom and wall thickness of the conical part should conform to the sinusoidal relationship as much as possible; the dimensional accuracy and surface roughness requirements of the solidified parts are reasonable: minimize the number and height of surface ribs; fully consider the performance characteristics and processing range of the spinning machine used; reduce the transition points of the spun part profile
5.4 Determination of the main process parameters of spun parts is as specified in JB/T7532. Additional notes:
This standard was proposed and submitted by the National Forging Standardization Technical Committee. This standard was drafted by the Beijing Nonferrous Metals Research Institute and the Beijing Institute of Mechanical and Electrical Engineering. The main drafters of this standard are Zhang Shunfu and Cai Fulin. 245
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