Development of a small-class bus for urban passenger transportation - course

Contents

Introduction

1. Overview of analogues

1.1 REFUELLING POD

1.2 BAW Street

1.3 Hyundai County

1.4 Yutong

1.5 Higer KLQ6728G

2. Description of the vehicle

2.1 Classification of buses

2.2 Description of the designed bus

3. Bus Carrier System

3.1 Types of carrier systems

3.1.1 Frame carrier system

3.1.2 Body bearing system

3.1.3 Frame-body load-bearing system

3.2 Body as load-bearing system of the bus

Conclusion

List of literature

Application

Introduction

Buses are passenger exchanges designed for the simultaneous transportation of more than 8 passengers. According to the structural scheme, buses are divided into single, articulated and bus trains.

A single bus is a passenger PBX operating without trailers and semi-trailers. Single buses make up the predominant majority of passenger exchanges and are used in all types of passenger transportation provided for by GOST 2077475 and classification (inner-city, suburban, local traffic, intercity, tourist, general purpose, excursion, international and others).

In this course project, the development of a small-class bus for urban passenger transportation will be carried out, since they are most widespread in Russia.

2.2 Description of the designed bus.

Inner-city buses are designed for mass transportation of passengers throughout the city. They should provide the ability to travel passengers sitting and standing, quick exchange of passengers at stopping points, ease of boarding and disembarking. The layout of the cabin of city buses should facilitate the passage and create the opportunity to concentrate on storage sites. For this purpose, a combined three-row seating arrangement is envisaged in the cabin, the number of which is approximately 40% of the total capacity of the bus.

The high dynamic qualities of city buses and a small braking distance provide the movement of buses with high speeds. City buses must have a minimum of 2 doors.

Since city buses operate on routes with high traffic intensity and are mostly equipped with gasoline engines, they must have high-efficiency cabin ventilation, and in winter a good heating system.

Small-capacity city buses used in the public bus system, unlike departmental (service) buses, should be structurally more reliable and adapted for daily intensive operation and have a reinforced design of individual mechanisms, assemblies and assemblies.

The engine of a small-class city bus should be quite powerful, but, at the same time, environmentally friendly and economical. Ideally, it is a hybrid engine with a capacity of about 120160 hp, meeting the environmental standards of Euro 4. It should also be equipped with a pre-start heater, which will increase its service life and facilitate start-up on cold days.

It is reasonable to use a single disc clutch with a hydraulic off-drive. The automatic transmission will contribute to lower driver fatigue and greater concentration on the road situation, which, in turn, will increase safety. Rear drive with a self-locking differential that promotes better cross-country ability in winter ice conditions.

Suspension - pneumatic with telescopic shock absorbers of double action and stabilizers of transverse stability.

Service braking system - disc, double-circuit, pneumatic with ABS. Spare - each circuit of the working system. Auxiliary - engine brake.

The bus compartment should be of sufficient height (190-200 mm) for the comfortable transportation of standing passengers, and also equipped with handrails. The bus shall be low floor for ease of boarding and disembarking; the floor is flat, which will allow to accommodate more passengers and luggage in the cabin. The cabin should have enough hatches and opening windows for better ventilation on hot days and a powerful heating system for heating the cabin on cold days. Also for the purpose of warming of salon it is necessary to use double glasses (double-glazed window).

The interior should be equipped with a special conductor seat, which, along with the driver's, has heating and a large range of adjustments. The steering column must also be adjusted, and the steering mechanism is supplemented by a hydraulic booster to provide the driver with maximum comfort. Another important feature is the presence of an on-board computer. With its help, the driver, while driving, will be able to control the technical condition and parameters of the bus. Windshields, side windows and mirrors shall provide maximum visibility. The presence of parktronics will allow the driver to better navigate in close parking conditions.

3. The carrying system of the bus.

The supporting system is called a frame or body of a car. The load-bearing system is used to install and attach all parts of the car.

The carrier system is one of the most responsible, material-intensive and expensive systems of the car. If the material intensity, cost and complexity of manufacturing the entire car is taken as 100%, then the carrying system can be more than 50% of this. The durability of the carrier system determines the terms of major repairs of the car. The total mileage of the car during operation largely depends on it. The carrier system significantly affects many of the performance properties of the car.

3.1 Types of carrier systems.

Different types of carrier systems are used on cars. The carrier system largely determines the type and layout of the car. Depending on the type of carrier system, cars are divided into frame and frameless. In frame cars, the role of the carrier system is played by a frame (frame carrier system) or a frame together with a body (frame carrier system). In frameless cars, the functions of the carrier system are performed by a body (body carrier system), which is called a carrier.

3.1.1 Frame carrier system.

The frame carrier system is used on all trucks, trailers and semi-trailers, on off-road cars, large and upper classes and on individual buses. Besides the main frame, the load-carrying system of automotive dump trucks includes an additional shortened frame - an overframe, on which the cargo body is installed and the body lifting mechanism devices are attached. The frame carrier system is simple in design, technological in production and repair, as well as universal, as it ensures the unification of ordinary and special cars. In addition, the frame carrier system allows modifications of a car with different bodies to be produced on one chassis.

3.1.2 Body bearing system.

The body carrier system is used on cars of especially small, small and medium classes, as well as on most modern buses. The body bearing system allows you to reduce the weight of the car, its total height, lower the center of gravity and, therefore, increase its stability. However, the body carrier system does not provide good isolation of the passenger compartment from the vibration and noise of the operating units and mechanisms, as well as from the noise of the tires arising when they roll along the surface of the road.

3.1.3 Frame-body load-bearing system.

Frame-body load-bearing system is used only on buses. With a frame-body load-bearing system, the bus body does not have a base. Frame and body base are combined into a single structure. Frames (transverse arcs) of body frame are rigidly attached to frame crossbars. The frame and the body frame work together, taking on all the loads. The frame-body load-bearing system has a simple design, is technological in production and is convenient to repair. Compared to the frame bearing system, the frame body has a slightly lower body weight and a lower floor height.

The vehicle load-bearing system is subject to the following requirements :

- durability corresponding to the service life of the vehicle ;

- stiffness, which prevents violation of operating conditions of units and mechanisms in any operating conditions;

- easy installation of systems, units and mechanisms, low position of the center of gravity and low loading height of the car, significant suspension stroke and large turning angles of the controlled wheels of the car.

The durability of the carrier system, corresponding to the service life of the car, should ensure the service life of the carrier system itself, exceeding the durability of all mechanisms, assemblies and systems of the car, as well as increase the mileage of the car to overhaul and total mileage in operation.

The rigidity of the load-bearing system, which prevents violation of the operating conditions of the units and mechanisms of the car, should ensure their constant mutual position on the load-bearing system under any conditions and modes of movement, as well as prevent breakdowns and breaks in the attachment of units and mechanisms and jamming of windows, doors of the body and cab of the car.

The low position of the center of gravity of the car should increase its stability and, therefore, safety even at high speeds. A significant suspension stroke should increase the smoothness and cross-country ability of the car, and large turning angles of the controlled wheels should improve the handling and maneuverability of the car.

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