JB/T 9175.1-1999 JB/T 9175.1-1999 Precision blanking parts structure processability JB/T9175.1-1999 Standard download decompression password: www.bzxz.net

JB/T9175.1—1999
This standard is equivalent to the chapter "Structural Processability of Precision Blanking Parts" in VDI3345-80 "Precision Blanking". Since the relative depth of the half-punching limit is also one of the important structural processability of precision blanking parts, 2.2.6 (relative depth of half-punching) is added. This standard is a revision of JB/Z272-86 "Structural Processability of Precision Blanking Parts". During the revision, the original standard was edited and the main technical content was not There are changes.
This standard replaces JB/Z272-86 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Forging Standardization. The responsible drafting unit of this standard: Beijing Institute of Mechanical and Electrical Engineering. The main drafters of this standard: Zhao Yanqi, Tu Guangqi, Li Ronghong. 207
1 Scope
Machinery Industry Standard of the People's Republic of China
: Structural processability
Precision blanking parts
Structural processability of fine blanked parts This standard applies to strong edge pressing precision blanking parts 2 Structural processability of fine blanking parts
2.1 General principles
JB/T 9175.1---1999
Replaces JB/Z 272-86
2.1.1 The processability of precision blanking parts refers to the difficulty of the parts during precision blanking. Under normal circumstances, the factors affecting the processability of precision blanking parts are:
The geometric shape of the part;
The size and form and position tolerance of a part;
The quality of the shear surface;
Material and thickness.
Among them, the geometric shape of the part is the main influencing factor. 2.1.2 The influence of the geometric shape of the part on the processability is called the structural processability of the precision blanking parts. The geometric shape of the precision blanking parts should be as simple as possible, with regular geometric shapes as much as possible, and avoid sharp corners, while meeting the technical requirements. Correct design of precision blanking parts is conducive to improving product quality and improving mold Tool life and reduce production costs. 2.1.3 The maximum size range of parts that can achieve precision blanking mainly depends on the strength of the mold, and is also related to the shear surface quality, mold life, etc.
This standard provides a chart of the maximum range of fillet radius, groove width, cantilever, ring width, aperture, hole margin, gear module, etc. It divides the difficulty of precision blanking of parts of various geometric shapes into three levels: SI represents easy;
S2 represents medium;
—S3 represents difficult. www.bzxz.net
The mold life decreases with the increase of the difficulty of precision blanking. Within the range of S:, the die punching components are made of high-speed tool steel (a0.2=3000N/mm), and the material to be precision blanked is ≤600 N/mm2.
Below the range of S, it is generally not suitable for fine blanking. 2.2 Structural elements of precision blanking parts
2.2.1 Fillet radius
The relationship between the difficulty of precision blanking and the fillet radius and material thickness is shown in Figure 1. The corners of the inner and outer contours of precision blanking parts must be rounded to ensure the life of the mold and the quality of the parts. The fillet radius should be as large as possible within the range allowed by technical requirements. It is related to the part angle, part material, thickness and strength. Approved by the State Bureau of Machinery Industry on June 24, 1999, 208
Implementation on January 1, 2000
IR≥0.6AR
ir 0.6AR
ar = AR
JB/T 9175. 1--1999
30°60°90°120°
4.0#2.0 Yuan
1.00.50.3
Example: It is known that the material thickness of the part with angle 30 is 3mm and the radius is 1.45mm. It can be found from Figure 1 that the difficulty of adding .T is between S. and S.
2.2.2 Slot width and cantilever
The width and length of the precision blanking slot and the width and length of the cantilever depend on the thickness and strength of the part material. Their width should be increased as much as possible and their length should be reduced to improve the life of the mold. The relationship between the difficulty of precision blanking and the groove width, cantilever and material thickness is shown in Figure 2. 15
amin = 0. 6 t
bmin - 0. 6t
Lmax 15a
101112131415
JB/T9175.1—1999
Example: Given that the groove width a or cantilever width b of the part is 4mm and the material thickness is 5mm, it can be found from Figure 2 that the processing difficulty is S: 2.2.3 Ring width
The relationship between the difficulty of precision blanking and the ring width and material thickness is shown in Figure 3. 101
Example: Given that the ring width of the part is 6mm and the material thickness is 6mm, it can be found from Figure 3 that the processing difficulty is between S. and S. 2.2.4 Aperture and hole margin
The relationship between the difficulty of precision blanking and the aperture, hole margin and material thickness is shown in Figure 4. Qun=0.6t
d nin 0.6r
Example: It is known that the aperture of the part is 3.5mm and the material thickness is 5mm. From Figure 4, the difficulty of adding 1 is S.: 210
2.2.5 Gear module
JB/T9175.1-1999
The relationship between the difficulty of precision blanking and the gear module and material thickness is shown in Figure 5. 1.5
Example: It is known that the gear module is 1.4mm and the material thickness is 4.5mm. From Figure 5, the difficulty is S:. 2.2.6 Relative depth of half-punching
Figure 6 shows a precision blanking and half-punching composite process part. The degree of deformation of the half-punching in Figure 6
is represented by C and calculated according to formula (1): C a
Where C. Relative depth of half-punching, mm;
t-·Material thickness, mm;
h-—Deepness of half-punching punch pressed into the material, mm. The limit relative depth of half-punching of low carbon steel is Cb-70%. .
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