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Figure 6 Schematic diagram for flanging-hole with thread for thin sheet connected
Table 3 The data of height(H) and Min removable times for flanging-hole with thread for thin sheet
connected Thread Material Inner diameter Outer High of of flanging-hole diameter of Min D1(Reference) flanging-hole(H) flanging-hole removable Plate D3 times thickness(T) (Tolerance 0～(Tolerance±(Time) +0.2) 0.1) M3 Steel <0.8 Forbid to form flanging-hole with thread of M3 0.8 1.0 ≥1.2
3、 The crazing and cracking of material is not allowed after flanging
1.1.6. Requirements for Riveting Quality
1、 0 lists some key riveting parameters.
Table 4 Riveting parameters
No. 1 2 3 4 Thickness of the Riveted Sheet (T2) 0.6 mm 0.8 mm 1 mm 1.2 mm Height of the Flanged Hole (h) 1.1 mm 1.2 mm 1.4 mm 1.6 mm Φ2.5 Φ2.5 2.5 2.5 Φ4.5 Φ4.5 12 30 Countersunk head screw M3 could be sunk into the plate surface, no need to use flanging-hole with thread. 2014-1-3
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Figure 7 Riveting procedure
2、 No iron scrap shall be found in riveting holes, and no visible deviation shall be found in riveting positions, and the number of cracks is no more than three. 3、 If the thickness of a metal sheet is greater than or equal to 0.8 mm, no bulge shall be found in the riveted surface. If a metal sheet is thinner than 0.8 mm, no dimple shall be found in the riveted surface, but embossments are allowed. 4、 After two sheets are riveted together, they must withstand the pulling force specified in 0.
Table 5 Minimum pulling force borne by riveted points
T1+T2 Pulling Force 0.8+0.8 or less ≥ 250 N 0.8+1.0 ≥ 350 N 1.0+1.0 ≥ 450 N 1.0+1.2 or greater ≥ 600 N 1.1.7. Exterior Requirements of parts The exterior requirements for metal sheet punching parts vary according to the products that the punching parts apply to, such as shelves, cabinets, and ejector levers.
1.2. Requirements for the Burr of Sheet-Metal Punching Parts
1.2.1. Definition of Burr Height：
Burr height is that which is left on the cross section of finished products for punching when blanking sheet metals, as shown in 0.
Figure 8 Burr height of sheet-metal structural parts
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1.2.2. Classifications of burr areas of structural parts
The Class A Area and Class B Area for the corners of structural parts according to burr requirements: Class A Area: touchable corner areas on the normal working position of products when delivered by sheet-metal suppliers and areas specially required in the design drawing, including but not limited to: 1、 Holes or slots for laying cables; 2、 Installation holes of connectors; 3、 Relatively sliding corners.
Class B Area: areas other than those in the Class A Area.
Identification examples of Class A Area and Class B Area of structural parts are as shown in 09, 010, 011, 012, and 013:
Corners visible when opening the door: Class A AreaFolded innersheet invisible All corners of cabling racks: when opening the door: Class A AreaClass B AreaTouchable corners: Class A AreaInstallation area of connectors: Class A Area
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Exposed corners: Class A Area
1. Unexposed corners after assembly: Class B Area2. Exposed corners after assembly: Class A Area, including but not limited to 3-13.13. Corners of 3. Exposed corners of frequently operated dismountable back door: parts: Class A Area Class A Area(e.g. lever)4. Corners of non- dismountable back door: Class B Area12. Corners of binding racks: Class A Area5. Exposed corners of square hole strips: Class A Area11. All exposed corners of the front door: Class A Area10. Panel corners: Class A Area (e.g. 6. Corners of slideway: transmission panel)Class A Area9. Four edges of accumulator cabinet: Class A Area; other inside corners: Class B Area8. Corners of dismountable parts: Class 7. All GPS cover boards and A Area (e.g. power protection cover and through holes: Class A Areaaccumulator cabinet cover)Figure 9 Identification of Class A and Class B Areas for outdoor cabinets
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1. Unexposed corners after assembly: Class B Area2. Exposed corners after assembly: Class A Area, including but not limited to 3-13.3. Exposed corners of dismountable back doors: Class A Area4. Corners of non- dismountable back doors: Class B Area DKBA
5. Exposed corners of square hole strips: Class A Area6. Corners of binding racks: Class A Area9. Exposed corners of front doors: Class A Area7. Corners around door frames: Class A Area8. Exposed corners of upper and lower enclosure frames: Class A Area
Figure 10 Identification of Class A and Class B Areas for indoor cabinet
1. Exposed corners of side plates: Class A Area8. Corners of reinforced ribs: Class B Area2. All corners of suspension loops: Class A Area7. Corners of backplate installation plates: Class A Area3. All corners of occulting bars: Class A Area4. Frontal corners of upper and 6. All corners of cabling racks: lower slideways: Class A AreaClass A Area5. Inside corners: Class B Area
Figure 11 Identification of Class A and Class B Areas for Subracks
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