Technical analysis on the renewal of a certain auto parts

 

Grinding method Grinding method is mainly used to increase the inner diameter of the bearing and reduce the outer diameter of the bearing, so that the inner and outer diameter of the bearing reach the specified value. No matter which type of bearing has 3 main dimensions: inner diameter, outer diameter and width. Under normal circumstances, the three bearings with the same size should be selected. If they cannot be selected, bearings with similar sizes should be selected as much as possible, so that the bearing capacity of the substitute bearing is close to that of the original bearing. When contemporary bearings need to insert sleeves (inner sleeves or outer sleeves), the fit of sleeve and shaft or bearing housing hole should be the same as the original bearing. The old parts of steel, such as drill pipes and half shafts, are processed into). The method of replacing automobile oil seal. Modification method The modification method of the automobile oil seal is mainly to insert a sleeve (inner sleeve) on the shaft or insert a sleeve (outer) in the oil seal seat hole, so that the selected oil seal can be installed and used. A3 steel is commonly used for the outer jacket, and steel is commonly used for the inner jacket. The thickness of the outer sleeve and inner sleeve shall not be less than 1.5. An interference fit is adopted between the outer shell and the base hole of the crude oil seal, and the inner hole of the outer shell and the oil seal are matched with the base hole of the crude oil seal. An interference fit is adopted between the inner sleeve and the journal, and a fit between the crude oil seal and the journal is adopted between the inner sleeve and the oil seal. Matters needing attention The oil seal is generally not replaced, only when it leaks oil. Pay attention to the following matters when replacing.

When the oil seal is only slightly leaking, if there are accessories, the oil seal can be replaced; if there are no accessories, the car can still be driven for a short period of time to search for accessories. Be careful when disassembling the oil seal to prevent damage to the oil seal, shaft and oil seal seat hole, so as to facilitate further judgment of the cause of the oil leakage. Because the oil leakage is not necessarily caused by the damage of the oil seal, it may also be caused by other reasons (such as the wear of the shaft). Do not clean the rubber parts with gasoline. When assembling the sealing ring and the cup, pay attention to cleaning the sealing surface and the center of alignment, and pay attention to not loose between the shaft and the bearing. For important parts and oil seals used to prevent low cat oil leakage, the original specifications should be used as much as possible to avoid replacement. If the oil seal is basically normal, the main cause of oil leakage is the shaft scars or wear grooves, you can change the relative position of the oil seal and the shaft to make them continue to work. The specific method is: add a 0.3m 1.0 washer on the back of the oil seal so that no oil leaks at the oil seal. In addition, the spring can be slightly tightened to prevent oil leakage. High-quality oil seals can be used to replace low-quality oil seals.

When replacing the oil seal, it is best not to damage the size of the journal and the oil seal seat hole at the oil seal, so that the standard oil seal can be used immediately when the standard oil seal is obtained. The fit between the outer diameter of the oil seal and the oil seal seat hole must comply with the regulations to prevent damage to the oil seal seat hole due to loose fit. Note on the replacement of the combination switch. After the combination switch of the original car is damaged, a separate ordinary switch can be used to temporarily replace the damaged switch in the combination switch (the ordinary switch can be fixed in the spare switch hole on the dashboard or below it) , It can also be fixed in other suitable positions), but pay attention to the following two points when changing the combination switch: the diameter of the wire used for connection must not be reduced at will; do not cut off all the wire ends in the original car line, so that you can buy it It is easy to wire the new combination switch. The modification method of the electric gasoline pump The electric gasoline pump of imported cars is generally fully sealed. After the oil leaks, it cannot be repaired and must be replaced. In the case of unable to purchase accessories, a QBin transistor gasoline pump can be used instead, but at this time a bracket must be made to install the transistor gasoline pump. The flasher retrofit method At present, electronic flashers with hazard warning functions are generally installed on imported cars. After the electronic flasher burns out, if the original accessories cannot be purchased for a while, the domestic electric flasher can be used instead. However, although this kind of flasher can make the turn signal lamp send a turn signal, it cannot make the turn signal lamp send a hazard warning signal. If there is still a hazard warning signal, one electric flasher and one starting relay must be used to replace it. The specific method is: install the electric flasher and the starting relay on an iron plate with a length, width, and thickness of 10, 50, and 12 respectively, and hoist the iron plate under the dashboard, and then connect the wires (using the original The hazard alarm switch of the car). After the modification of the wiring method of the flasher on the imported car in Gongquan 1, two current loops through the flasher are generated when the hazard alarm switch is turned on. One of the current loops is: battery positive electrode, fuse, flasher battery terminal ~ flasher switch terminal, hazard alarm switch, right turn signal light, ground iron, battery negative electrode. The current in this loop makes the right turn signal light flash. The other current loop is: battery positive-fuse~flasher battery terminal~flasher switch terminal-hazard alarm switch, starter relay coil~grounding~battery negative electrode. The starter relay contacts can directly replace each other according to the flashing of the right turn signal light. To replace each other, the ground frequency of the generator must be switched on and off so that the left turn signal light flashes at the same time (the type is changed to the corresponding type when the contact is closed. For example. : When using the former to replace the latter, the battery needs to be changed from the outer ground generator to the inner ground generator through the fuse and starter relay contact to the left turn signal lamp, that is, the power supply to the field winding). At this time, the left and right turn signal lights flashed at the same time, and one of the two terminals was insulated from the rear cover of the generator, and the other signal was normal. One is connected to the back cover of the generator (grounding). Due to the coil current of the starting relay in the electric flasher circuit. For the electromagnetic vibrating regulator, the contact gap should be adjusted carefully, which is only about 0.3 people. Therefore, the blinking frequency of the turn signal lamp is not obvious and the spring force is not obvious, and sometimes the additional resistance should be further checked. For change. For a generator with a nominal voltage of 14V, the regulator’s regulating voltage should be adjusted for the car generator.

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