1. Vehicle layout plan for pure electric commercial vehicles
Compared with pure electric passenger vehicles, the layout space of pure electric commercial vehicles is more generous. This section will briefly discuss the principles and main contents of the layout of pure electric commercial vehicles.
The layout of a pure electric commercial vehicle should meet the requirements of safety, environmental protection, relevant regulations, international conventions, and corresponding functional and performance requirements. The overall balance of the whole vehicle is the basis of vehicle layout. The design should put the service performance in the first place, and then consider the problems in the order of manufacturing, maintenance, and appearance, so that the whole vehicle is easy to use, bad repair, easy to build, and good-looking. The layout of the whole vehicle is coordinated and compatible with the appearance concept. Pure electric commercial vehicles should focus on the assembly requirements of high-voltage components.
The high-voltage components of pure electric commercial vehicles are mainly composed of electric drive systems, energy storage devices, electric accessories, electric control units, power receiving devices and other related high-voltage components. The electric control units between the various systems ensure the safe operation of the entire vehicle.
① According to market demand, energy storage devices such as power battery packs mainly have bottom-mounted middle section plus rear section and top-mounted plus bottom-mounted rear section layout forms: bottom-mounted devices should fully consider the heat dissipation, heat preservation requirements and collision resistance requirements of energy storage devices, and top-mounted storage The corresponding protective cover should be added to the energy device.
②Electric accessories and electronic control units are mainly arranged under the rear seats of the vehicle and the rear high-voltage component compartment. The electronic control unit and the rear wall ensure a certain safety distance.
③If there is a power receiving device, the power receiving device is generally arranged on the roof of the car.
The design of low-floor or low-entry pure electric passenger cars should meet the national standard GB 19260)-2016 ``Low-floor and low-entry city bus structure requirements''. The overall space design requirements such as the height of stepping from the ground and the height of the cabin.
Among them, the requirements for the width of the front wheel cover are as follows:
① For low-floor, low-entry passenger cars with a length of ≤9m, the width of the passage between the front wheel covers is ≥550mm.
②For low-floor passenger cars with a length of >9m, the width of the passage between the front wheel covers is ≥800mm
③For low-entry passenger cars with a length of >9m, the width of the passage between the front wheel covers is ≥600mm.
The width of the passage between the rear wheel covers is ≥500mm; the width of the passage between the wheel covers should be measured from the floor surface to the upper 1800mm range. When the vehicle is in normal driving quality and the body lifting system is not working, the longitudinal gradient of the channel gradient should not exceed 8%, and the lateral gradient should not exceed 5%.
The height of the first step off the ground should be measured when the body is in normal driving quality and placed on a flat horizontal surface. The specific requirements are as follows:
1 For low-floor passenger cars-the first step distance from the ground ≤ 360mm
The first-stage stepping distance of a low-entry passenger car with a 2m air suspension is ≤360mm. The first-stage with a mechanical suspension
Distance from the ground to step ≤380mm
The typical layout of high-voltage components for low-floor pure electric passenger cars is shown in Figure 2-50. The power battery pack is generally arranged at the bottom of the rear section and the bottom space under the seat or on the roof, and the electric drive system is arranged at the bottom of the rear section. The electronic control components are arranged in the rear high-voltage electrical device compartment.
The pure electric truck adopts the electric drive axle scheme. The power battery pack can be arranged in the middle or on both sides of the two longitudinal beams of the chassis and the rear of the cab. The arrangement of the power battery pack should meet the requirements of the bodywork space. Avoid moving parts on the vehicle chassis and consider the vehicle's center of gravity distribution and vehicle load distribution. In addition, reliable mechanical and electrical connections need to be provided between the power battery pack and the vehicle, and the requirements for heat dissipation and heat preservation must be fully considered. The outer dimensions, axle load and quality limits of trucks shall meet the requirements of GB1589-2016 Outer Dimensions, Axle Loads and Quality Limits of Automobiles, Trailers, and Automobile Trains'', and meet the following conditions:
①Should not exceed the maximum allowable axle load limit of the front axle.
②Should not exceed the maximum allowable axle load limit of the rear axle (group).
③Should not exceed the maximum design total mass of the vehicle.
④ The minimum axle load of the steering shaft should meet the vehicle design requirements.
⑤ The minimum axle load of the drive shaft (group) should meet the vehicle design requirements.
Schematic diagram of the typical layout of high-voltage components of pure electric trucks
Comments