This standard specifies the shape and structural elements that cold extruded parts should follow. This standard applies to ferrous and non-ferrous metal cold extruded parts. JB/T 6541-2004 Shape and Structural Elements of Cold Extrusion Parts JB/T6541-2004 Standard download and decompression password: www.bzxz.net

ICS25.010
J32
JB
Machinery Industry Standard of the People's Republic of China
JB/T6541--2004
replaces JB/T6541-1993|| tt||Cold extrusion parts
Shape and structure elements
Shape and structure elements for cold forging part2004-03-12 Released
2004-08-01 Implementation
The National Development and Reform Commission of the People's Republic of China released the foreword,
! Scope
2 symbols.
3 Classification of cold extruded parts
3.1 Classification of cold extruded parts by shape
3.2 Classification of cold extruded parts by process.||tt ||Structural requirements for cold extrusion parts...
4
4.1
4.2
4.3
4.4
4.5|| tt | | 4.6 | | tt | | 4.7 | The ratio of the bottom thickness and wall thickness of the extruded part, mesh
Forward extrusion die entrance angle 2α, reverse extrusion punch taper angle β composite extrusion part with skin position and thickness h1
cold The size and location of the pockets in the cold extruded parts with the inner and outer corner radius of the extruded parts
Forward extrusion of solid parts
Figure 2
Figure 3||tt| |Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Forward extrusion of hollow parts
Forward extrusion shape examples of solid parts
Forward extrusion shape examples of hollow parts
Reverse extrusion of cup-shaped parts
Reverse extrusion of cup-rod parts ,
Reverse extrusion part shape example
Cup-to-cup composite extrusion
Cup-to-rod composite extrusion
Rod-to-rod composite extrusion||tt ||Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17||tt| |Figure 18
Figure 19
Table
Examples of shapes of composite extruded parts
Forging and extrusion composite forming
Examples of shapes of extruded parts||tt| |Radial extrusion.
Radial extrusion part shape example
Compound extrusion part with skin position
Reverse extrusion part fillet radius
Forward extrusion Part fillet radius
Pocket depth and position
Aspect ratio of the inner hole of the cup-shaped reverse extrusion part
Table 2 Bottom thickness and wall thickness ratio of the cup-shaped reverse extrusion part , times
JB/T6541—2004
JB/T6541—2004
Foreword
This standard is based on JB/T6541—1993 "Shape and Structure of Cold Extruded Parts" Revision of "Elements". Compared with JB/T6541--1993, the main changes in this standard are as follows: the length-to-diameter ratio of the reverse extrusion inner hole, L/d, is generally limited by L/d, ≤ 2.5 for steel parts. If the mold design is effective Special device, its value can reach L/d,=5
increased by 3.2.5. Radial extrusion is more and more widely used in cold extrusion technology. For this reason, the principle of radial extrusion (Figure 14) and the shape example of radial extrusion parts (Figure 15) are added. This standard replaces JB/T6541-1993.
This standard is proposed by China Machinery Industry Federation. This standard is under the jurisdiction of the National Forging Standardization Technical Committee. This standard was drafted by: Shanghai Jiao Tong University, Beijing Institute of Mechanical and Electrical Engineering. The main drafters of this standard: Wu Gongming, Zhao Sue, Chen Jun, and Li Shezhao. The previous versions of the standard replaced by this standard are: JB/T6541-1993.
1 Scope
Shape and structural elements of cold extruded parts
This standard does not specify the shape and structural elements that cold extruded parts should follow. This standard applies to ferrous and non-ferrous metal cold extruded parts. 2 symbols
r,r
R.R2
2g-
B
S
hi
d| |tt||D,
Do
Lo
The fillet radius of the inner surface of cold extruded parts, in mm: The fillet radius of the outer surface of cold extruded parts, in mm ;The entrance angle of the forward extrusion die, the unit is (°); the dimension angle of the reverse extrusion punch, the unit is (\): the wall thickness of the extrusion part, the unit is mm:
extrusion part method Blue thickness or bottom thickness, in mm: Thickness of extruded parts with skin, in mm:
Inner diameter of cold extruded parts, in mm:
Outer diameter of cold extruded parts, in units mm:
The diameter of the hair, the unit is mm:
The length of the hair, the unit is mm:
The length of the extruded part of the forward extrusion part, the hole of the reverse extrusion cup Depth, unit is mm: L
1——Depth of the extrusion part cavity, unit is mm. 3 Classification of cold extruded parts
3.1 Classification of cold extruded parts by shape
a) Rotationally symmetric parts:
b) Simple axisymmetric and asymmetric parts; ||tt| |c) Extruded parts with grooves, tooth shapes, etc. 3.2 Cold extrusion parts are classified by process
3.2.1 Forward extrusion
The process is mainly divided into forward extrusion of solid parts (Figure 1) and forward extrusion of hollow parts (Figure 2). Figure t
Positive extrusion of solid parts
Figure 2 Positive extrusion of hollow parts
JB/T 6541—2004
JB/T6541—2004
An example of the shape of a positive extrusion solid part is shown in Figure 3, and an example of the shape of a positive extrusion hollow part is shown in Figure 4. Middle in middle
Figure 3 Example of forward extrusion shape of solid parts
Figure 4 Example of forward extrusion shape of hollow parts
3.2.2 Reverse extrusion
The process is mainly divided into cup shapes The piece is counter-extruded (Fig. 5) and the cup-rod piece is counter-extruded (Fig. 6). An example of the shape of the anti-extrusion part is shown in Figure 7,
Product
Figure 5 Cup-shaped part anti-extrusion
Figure 6 Cup-rod anti-extrusion
China, China and Austria
Face
Figure 7 Example of reverse extrusion shape
3.2.3 Composite extrusion
TF
Concave||tt The ||hulou
process is mainly divided into composite extrusion of cup and cup (Fig. 8), composite extrusion of cup and rod (Fig. 9), composite extrusion of rod and rod (Fig. 10), etc. An example of the shape of a composite extruded part is shown in Figure 11.
3.2.4 Extrusion
The process consists of forging and extrusion (Figure 12). An example of the shape of the upsetting part is shown in Figure 13.
2
Picture 8 composite extrusion of one cup and one piece
Device
Download
Picture 10 composite extrusion of one rod and one rod||tt| |face
JB/T6541—2004
高楼
Figure 9 Cup and one rod composite extrusion
Figure 11 Example of composite extrusion shape||tt| | E | | tt | ||JB/T6541—2004
3.2.5 Radial extrusion
The direction of metal flow is perpendicular to the direction of movement of the punch, and branched parts and cup-shaped parts can be formed (Figure 14 ), an example of the shape of a radial extrusion part is shown in Figure 15.
Upper main building
Fleece ring
Upper concave mold
Work piece
Lower concave core
Lower energy
a ) | tt | tt||4.1 | Changes in mechanical properties: The structure of cold extruded parts must ensure sufficient die life: c
The structure of cold extruded parts should minimize the forming steps while ensuring the forming and die life; d) ||tt| |The structure of cold extruded parts should consider the influence of materials and subsequent heat treatment processes: e)
Asymmetrically shaped cold extruded parts can be merged into symmetrical shapes for extrusion. f)
Upper plate
Gross address
Lock
T. piece
Lower protruding floor
4.2 Anti-extrusion cup-shaped piece Aspect ratio
The aspect ratio of the inner hole of the cup-shaped reverse extrusion part L/d, see Table 1. When a special device is used for steel back-extrusion, the length-to-diameter ratio L/d can reach 5. 4
material
material
Lyfd.
pure| |tt||Table 1 Aspect ratio of inner hole of cup-shaped reverse extrusion parts
Aluminum
≤7
Ratio of bottom thickness and wall thickness of cup-shaped reverse extrusion parts| |tt||4.3
Copper
$5
The ratio h/S of the bottom thickness h and wall thickness S of the cup-shaped reverse extrusion part is shown in Table 2. Steel alloy
≤3
Table 2 Bottom thickness and wall thickness ratio of cup-shaped reverse extrusion parts
Material
Material
h/s|| tt||Pure aluminumbZxz.net
>0.5
4.4 forward extrusion die entrance angle 2α, reverse extrusion punch taper angle 6 and its alloys
≥1.0||tt| |JB/T6541—2004
Steel
≤2.5
Steel
≥1.2
2 The design of α angle should consider the rationality of the structure and the unit area Extrusion force, generally the mouth angle 2α of the forward extrusion die is 60°~120°, and the cone angle β of the reverse extrusion punch is 7°~9°. In special cases, it can be a flat-bottomed punch, and its interface should be rounded. . 4.5 Composite extruded parts with skin position and thickness ht Under normal circumstances, the cup-shaped extruded parts with skin position should be placed in the middle (Figure 16a), and the flat extruded parts with skin position should be placed at the big end (Figure 16b ),
The skin thickness h is greater than or equal to the wall thickness S.
a)
b)
Figure 16
Compound extrusion parts with skin position
4.6 Inner corner radius and outer circle of cold extrusion parts Corner Radius The outer ring corner radius R and the inner ring corner radius of the anti-extrusion part are generally the same as the fillet radius of the part. In special cases, they can be appropriately increased in order to facilitate the metal flow (Figure 17). It should be noted that the distance between the two fillets cannot be less than the wall thickness. The fillet radius R of positive extrusion parts is generally 3~10mm, and R2 is 0.5~1.5mm, see Figure 18. Figure 17 Corner radius of reverse extrusion parts
JB/T6541—2004
Figure 18 Corner radius of forward extrusion parts
4.7 Size and location of the pockets of cold extrusion parts| |tt||The depth 1 of the cavity should be smaller than the diameter d. When there is a cavity, the location of the cavity should be set at the symmetrical center of the part (Figure 19). Depth and location of the national point
Figure 19
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