The KPD series is a low-voltage rail powered electric flatcar, which is sent to the flatcar through a conductive rail to a step-up transformer and driven by a motor. Its main advantage is that it is not only safe but also not afraid of scalding, smashing, or cross transportation due to the absence of cables. Based on the unique working principle of electric flatcars, the installation requirements for the tracks of electric flatcars are different from those of ordinary tracks. It is required that the tracks of electric flatcars be insulated from each other to achieve a certain resistance value.
1、 Process characteristics
(1) In response to the insulation requirements of the flat car track, insulation treatment is applied to the bolts, and insulation elastic pads are added under the track pressure plate, effectively increasing the insulation resistance value between the tracks.
(2) Due to the rusting of tracks and the complexity of the environment between tracks, the resistance values measured by instruments such as electric meters are often not the true resistance values. In practice, this project summarizes the use of electric welding machines for resistance value testing experiments.
2、 Operation points
1. Processing of reserved holes
First, remove the loose concrete and stones in and around the reserved holes of the equipment foundation, then clean up the debris in the reserved holes, and finally use a small blower to clean the holes. If there is leakage of steel bars in the reserved holes, it should be dealt with in a timely manner to ensure that the steel bars cannot come into contact with the embedded bolts.
2. Installation of tracks
The only difference between track installation and regular track installation is the addition of elastic insulation pads under each track pressure plate.
3. Installation of bolts
(1) Bolt insulation treatment: In order to ensure the insulation of bolts when they are wet with water, the bolts should be soaked in melted asphalt. That is, after the asphalt melts, the part below the bolt thread should be soaked twice, and then taken out and dried.
(2) The specific method of bolt installation is: ① The oil and rust on the anchor bolts must be cleaned thoroughly. ② After inserting the bolt, its horizontal position and top height should be corrected and fixed The amount of water used for mixing grout should be reduced compared to the recommended amount, and the specific amount of water added should depend on the site requirements When anchoring bolts with grouting material, the following requirements should be met: the mixed grouting material should be poured into the bolt holes, and vibration and insertion are strictly prohibited during grouting. The bolts should not be adjusted after grouting is completed; When it is difficult to directly inject grout during grouting construction, a flow channel is used as an auxiliary construction method; During the grouting process, if there is surface bleeding, dry grout should be spread to absorb the moisture.
4. Copper bar installation
For the installation of track copper bars, bolt connections should be used, and then the copper bars should be connected to the channel steel with bolts. The connection between copper bars should be made by welding with copper bars.
5. Resistance testing experiment
After the installation of the track and copper bars, a resistance test experiment needs to be conducted on the track. Testing was conducted using an electric welding machine, and the experimental results were accurate. The specific method is to connect one end of the grounding wire of the welding machine to one track, and use a welding gun to test the welding of the other track. If only induced sparks are generated and cannot be welded, it indicates that the resistance value meets the requirements. If welding slag can be generated, it indicates that the current is connected and the resistance value cannot meet the requirements.
6. Concealed orbit
Conceal the already installed track with asphalt sand to ensure insulation, and use concrete to conceal the remaining parts.