When the front axle of an automobile is bent or twisted, the thermal straightening method can be adopted, that is, the parts of the front axle of an automobile are locally heated to 500-600℃, and then manually straightened. In addition, you can also use the hydraulic straightening machine of the front axle of the car for correction. This straightener can be calibrated and inspected at the same station, which not only ensures the calibration quality, but also improves the production efficiency.

Because the front axle of the front axle can't have any cracks, the wear thickness of the two leaf spring seats can't be reduced by more than 2mm. When two leaf spring seats lean against a standard plane, the maximum clearance should not be greater than 0.8 mm, the wear of anchor bolt holes and leaf spring positioning holes on the leaf spring seats should not be greater than 65438 0 mm, and the thinning of the end face of the main pin hole should not be greater than 2 mm.

2. Check the bending and twisting of the front axle.

Along the cross section direction of the front axle, the twist angle between the axes of the two main pin holes should be no more than 30', the inclination angle of the main pin hole and the axis distance of the main pin hole should comply with relevant regulations, the fit between the bushing and the steering knuckle kingpin is clearance fit, the axes of the upper and lower holes should be coaxial, the thread damage at the steering knuckle end should not exceed 2 teeth, and the straightness error of the tie rod should not exceed 2 mm ..

When assembling optical fiber horizontally and vertically, ensure that the small end of the taper neck of each ball pin is lower than the upper end face of the taper hole 1~2 mm, without looseness and jamming, all parts are connected in a semi-solid state, the cotter pin is complete, and the dustproof device is in good condition.

Repair of the front axle: the front axle is also called I-beam, and the inspection of the front axle generally tests the bending and twisting of the front axle.

3. How to repair the I-beam kingpin?

When the main pin hole of I-beam is worn, so that the fit clearance between the hole and the main pin is greater than 0. 10mm, it can be repaired by repair size method or insert method. When the end face of the main pin hole is worn, if it exceeds 2 mm, it can be filed by hand on the original basis.

First, pile up the lower end face of the ground, and then use mechanical processing to level it off. At this time, the upper end face with less wear can be used as the positioning reference to wear the lock pin hole of the king pin. Insert the lock pin into the lock pin hole and tighten it with the nut. If the shoulder of the thread root is not less than 2mm away from the boxing plane, the tapered hole should be added and re-drilled, or an enlarged locking pin should be used.

In use, whether the kingpin hole or the kingpin is worn, when the fit clearance exceeds 0. 10mm, it can be repaired by the repair size method or the insert method.

4. The inclination angle of the front axle is suitable for inspection.

If the vertical edge of the angle ruler is inclined from the vertical edge of the test bar, the front axle is inclined. Pulling inspection: Draw a thin line 1 in the center of the two main pin holes of the front axle 3.

Then measure the distance between the two steel plate bases and the cable with a steel ruler 2. Compared with the qualified front axle, a larger size means bending down, and a smaller size means bending up. Check with tester: put the tester base on the front axle steel plate base, and insert the spindle into the steering shaft pin hole.