GB 4909.5-1985 Test methods for bare wires - Bending test - Repeated bending

This test method is applicable to the inspection of the bending performance of copper, aluminum and their alloy conductors with a nominal diameter of 0.8 to 8.0 mm, and circular and non-circular cross-section conductors with a nominal size of less than 20 mm (such as rods and tram lines, etc.). This test method is to fix one end of the test piece, and bend the free end along a cylindrical surface of a specified radius in 90° directions in both directions until the specified number of times or until the test piece breaks. GB 4909.5-1985 Bare wire test method Bending test Repeated bending GB4909.5-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test methods for bare wtres
Bend test
Reversebend test
UDC621.315.14
GB 4909.5—85bzxz.net
The provisions adopted in this standard are consistent with those of the international standard ISO2625 (1973) and refer to BS standard 1639 (1964). 1 Applicable examples
1.1 This test method is applicable to the inspection of the bending properties of copper, aluminum and their alloy conductors with a nominal diameter of 0.8 to 8.0 mm, the cross-section with a nominal size of less than 20 mm and non-circular cross-section conductors (such as rods and tram lines, etc.). 1.2 This test method is to fix one end of the test piece, and perform a 90° bending test in the positive and negative directions from the cylindrical surface of the specified radius at the outlet end, and bend it to the specified number of times or until the test piece breaks. 2 Test equipment
2.1 The repeated bending test machine for circular cross-section conductors is shown in Figure 1 and should meet the following requirements: the clamping die should have sufficient hardness, and the surface of the measuring column in contact with the test piece should be polished, and its surface roughness should be R, 0.63μ. The clamping die should ensure that the axis of the test piece and the center line of the test machine lever are located in the same plane, and the plane is parallel to the clamping surface. The center lines of the two bending cylinders of the clamping die should be parallel to each other. The plane of the two center lines is perpendicular to the center line of the lever at the starting position. There should be an appropriate distance between the center line of the bending cylinder and the highest point of the clamping surface.
2.2 The repeated bending test device for conductors with special cross-sections is shown in Figure 2. Issued by the National Bureau of Standards on January 31, 1985
Implemented on December 1, 1985
GE 4909.5—85
Figure 1 Repeated bending test machine for cross-section conductors
Figure 2 Repeated bending test device for conductors with special shapes d—diameter of circular conductor! α—Narrow side of the conductor with special cut surface 1—Radius of the bending cylinder, h—Distance from the top surface of the support to the bottom surface of the guide block, distance from the plane of the axis of the cylindrical support to the nearest point of contact with the specimen; r—Distance from the rotation axis of the operating handle to the top plane of the cylindrical support: 2—Gap between the specimen and the cylindrical support; 1—Push rod or sleeve 2—Test piece: 3—Guide block, 4—Push rod rotation axis, 5—Bent cylinder A and B; 6—Support, 7—Support clamping surface; B—Nearest point of contact of the specimen, 9—Guide groove, 10—Vise
3 Preparation of specimens
3.1 Sampling Take 5 specimens of about 300mm in length from one end of the specimen that has passed the appearance inspection. When sampling, try to avoid stretching, torsion, bending or other mechanical damage to the specimen. 3.2 Straightening The specimen should be straightened carefully by hand. If necessary, the specimen can be placed on a wooden pad and tapped lightly with wood. 4 Test steps
4.1 Select the die according to the table and install it on the testing machine or clamp, mm
Nominal size of the test piece d(a)
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