If the switch rail is not closely attached to the basic rail, the train wheelsets will impact the tip of the switch rail, and the wheel load will be transferred from the basic rail to the switch rail prematurely, which will easily lead to the failure of the switch and seriously affect the safety and stability of train operation.

Close-fitting cross section of turnout rail

When the switch point rail is not closely attached to the basic rail, the lateral force of the wheel-rail on the switch point rail is obviously increased, which may increase the degree of tight attachment, and the lateral crossing will aggravate this phenomenon, thus affecting the service life of the switch.

The contradiction between the defects of domestic 18# high-speed turnout switch rail and the lack of technical standards and handling experience of maintenance personnel is increasingly prominent. Habitually, the data of poor frame size are not used effectively, and even the high-speed turnout is blindly considered to have good structure and equipment, which makes the deep-seated and structural problems of the turnout not fully discovered and rectified.

Sectional view of repulsion force of turnout rail

If we strengthen the treatment of switch rail diseases, innovate treatment methods and improve treatment efficiency, we can put more energy into other work and equipment maintenance, the equipment quality and TQI can be better, the equipment deterioration is slower, and the indirect benefits cannot be estimated.

Remedial measures for loose adhesion of switch rail

According to the field practice and renovation experience, the reasons for the poor adhesion of the switch rail of the passenger dedicated line 18 high-speed turnout are deeply analyzed, and the renovation countermeasures are formulated one by one:

1. Maintenance personnel know little about the technical standards of turnouts and lack experience.

Remediation countermeasures: create a good learning atmosphere for business skills, strengthen turnout business training, and ensure that the professional skills of maintenance personnel are effectively improved.

2. The control force of each part of the turnout decreases and the turnout deviates.

Countermeasures: Measure the absolute position of turnout with track measuring instrument, confirm the front and rear position and center position of turnout, and ensure the accurate positioning of turnout.

3. The size of turnout frame is poor.

Countermeasures: Control the frame size between the two basic rails strictly according to the standard, and adjust the position of the two basic rails by adjusting the bent basic rails in the case of straight strands, so that the frame size is within the allowable range.

Cross-sectional view of close contact between turnout rail and basic rail

4. The basic track direction is not good.

Countermeasures: Straighten the direction of the basic rail and correct the position and vector of the bending point of the basic rail.

5. There is a gap between the basic rail, the rail bracket and the shoulder of the sliding bed.

Countermeasures: Straighten the heart rail or basic rail, straighten the direction and change the gauge.

6, the length of the top iron does not meet, resulting in hard bending of the switch rail.

Remedial measures: add a pad adjustment piece between the top iron and the basic rail to solve the problem that the top iron is too short, and polish or replace the too long top iron. When adjusting the length of the top iron, it is necessary to avoid blindly adding adjusting parts to eliminate the tightness of the top iron, which will cause the top iron to be too strong and the top rail to bend.

7. There is a fat edge between the working edge of the basic rail and the non-working edge of the switch rail, which leads to the loose or false joint of the switch rail.

Remediation countermeasures: Strengthen the inspection of switch point rail and basic rail, polish the "fat edge" in time when it is found, and be careful not to scratch the rail surface.

8. Insufficient clearance between rollers will lead to excessive conversion resistance.

Countermeasures: Adjust the roller to ensure the standard clearance, ensure that the rotation of turnout rail is converted from sliding friction to rolling friction, and reduce the conversion resistance.