There is a growing need for the maintenance of four-wheeled low-speed electric vehicles, with 9 of the 10 masters working on two-wheeled electric vehicles often in trouble, while the masters who repair four-wheeled vehicles are more delicious. A clearly marked road map is essential for the repair of the four-wheeler — it details the route of the reverse gear, the reverse image, the direction of components such as probes, electrical parameters, spare parts functions and the wiring method, which will help the master quickly clear the logic of the circuit。
You need to know the signs on the map. In the graphic symbol, the circle represents the contours of the electric motor, and the two-polar breaker displays a visual disconnection function; in the text symbol, m represents the electrical motor, l represents the fireline, on is open, run is activated; and there are specification parameters such as core numbers, nominal cross-sections, which determine the performance of the conductor and the layout of the line. These symbols are like the "ciphers" of the circuits, so they can read the route。
The low-speed electric four-wheeler drive system is typically equipped with 2. 8 kw never-drusher. The battery is a 60v system of 12 v120 ah x 5, with a maximum speed of 45 km/h, a 15 per cent slope and a continuation of 120 km. The power plant has the characteristics of a low-speed constant rectangular, high-speed constant power, with a low-speed large-turned rectangular efficiency of 0. 75-0. 85 and a high-speed constant power efficiency of 0. 8-0. 9, which allows vehicles to climb up the slopes and save electricity at high speed。
Several typical failures were encountered in maintenance. For example, there's no electricity in the car. Check if the emergency switch and the ignition switch are on, if the insurance is burned, then the dc converter's voltage is measured. – when the ignition switch is open, 60 v voltage between the dc converter's red and black lines and 12 v voltage between the blue line and the green line, if not the dc converter. If the entire vehicle has electricity but cannot walk, check whether the switch safety, the electronic switch is normal, the direct-flow contacts are inhaled, and the controller and the electric power are working. There are also slots that correspond to abnormalities, which may be caused by the location of the electronic changer, the fault of the cable, or by the widening of the gap following the high temperature of the electric magnet. Interference problems are also common, for example, in front of a loudspeaker vehicle, on foot charge signal lights, most of which are power or system interference, requiring a charger to be cut off by a diode or an instrument indicator light to be filtered。
Day-to-day maintenance should also be focused on several points: checking whether batteries are charged properly, leaks are leaking, the connection lines are loose; the electrics turn around with flexibility, noise and short circuits; the controller has an abnormal light; the tire pressure is normal and the brake system is not in question. The power supply must be switched off before repairing it。
Finally, there are three techniques to understand the circuit map: first, tracking the flow of electricity and how it is distributed from the source to the component; second, distinguishing between the type of line, the size of the power line, the colour of the colour (e. G. The red orthodox), the detail of the signal line, the transmission of sensor information, and the control of the line; and third, keeping an eye on nodes and branches, where the current is diverted, and studying how they are connected to clear the circuit logic. If you've got this, you can easily read the map and quickly find the failure point。
