QC/T 1127-2019Technical specifications and test methods for aluminium alloy control arm assemblies of passenger car MacPherson suspensions (English PDF)

3.1 Aluminum alloy control arm mount of Macpherson suspension

The triangle control arm, which is composed of aluminum arm, ball pin, rubber bushing, as shown in Figure 1, AND is used for Macpherson suspension (hereinafter referred to as the control arm assembly).

3.7 Maximum design axle load (FA)

The maximum axle load, which is specified by the vehicle manufacturer.

4.1 General requirements

4.1.1 The control arm assembly shall be free from defects, such as white spots, rust, scratches, bumps, folds, cracks, burrs, looseness.

4.1.2 The ball pin and the ball seat shall be cleaned before assembly. It shall be flexibly rotated after assembly, without loosening or jamming.

4.2 Material properties

Aluminum alloy materials shall comply with the provisions of GB/T 3190 and GB/T 3191, OR meet the requirements of the drawings.

4.3 Performance requirements

4.3.1 Aluminum body compressive strength limitation

When carrying out the test specified in 5.1, FC shall be within the range of [3FA, 4FA], OR meet the requirements of the drawing.

4.3.2 Aluminum body tensile strength limitation

When carrying out the test specified in 5.2, FP shall be within the range of [3FA, 4F], OR meet the requirements of the drawing.

4.3.3 Bushing press-off force

When carrying out the tests specified in 5.3, Fk shall meet the requirements of the drawings.

4.3.4 Longitudinal fatigue test

During the tests specified in 5.4, none of the following phenomena shall occur:

a) The aluminum alloy arm body has cracks, which have a length of more than 10 mm OR does not meet the requirements of the drawing;

b) The ball pin is cracked, broken, or slipped from the arm body;

5.4 Longitudinal fatigue test

Connect it to the test fixture, according to the actual vehicle installation method OR install it according to the manufacturer's requirements. Apply a longitudinal load Fx to the control arm assembly, through the center of the ball pin, as shown in Figure 5.

Figure 5 -- Schematic diagram of installation for test of longitudinal fatigue

5.4.2 The loading direction conforms to the provisions of 3.2. The loading load is positive, in the positive direction of the X-axis of the vehicle's coordinate system, negative otherwise.

5.4.3 Load size: -0.3FA to +0.7FA OR according to the requirements of the drawings. Loading waveform: Sine wave; loading frequency: 1 Hz ~ 3 Hz; number of loadings: 150000 times or according to the requirements of the drawings.

5.4.4 The installation torque of fasteners shall meet the requirements of the drawing.

5.4.5 During the test, the non-metallic parts shall be cooled by blowing air, so that the surface temperature does not exceed 70 °C.

5.5 Lateral fatigue test

5.5.1 Place the control arm assembly and the accompanying test piece horizontally. Connect it to the test fixture, according to the actual vehicle installation method OR install it according to the manufacturer's requirements. Apply a lateral load Fy, to the control arm assembly, through the center of the ball pin, as shown in the Figure 6.

Figure 6 -- Installation diagram for test of lateral fatigue test

5.5.2 The loading direction is in accordance with the provisions of 3.3. The loading load is based on the positive direction of the Y-axis of the vehicle's coordinate system as positive, otherwise it is negative.