Investigation of the mechanism of the two-cylinder engine

Introduction

At this time, a strategy has been defined to accelerate the socio-economic development of our country for the long term. It is planned to accept and raise productive forces and production relations to a high-quality stage, to accelerate scientific and technological progress. At an accelerated pace, it is necessary to develop mechanical engineering, which is a key industry that determines the pace of technical re-equipment of all sectors of the national economy.

It is possible to solve such important economic tasks to increase the efficiency and quality of products by accurately designing the mechanism.

The goal of the course project is to consolidate the theoretical material and knowledge obtained during the study of the course, practical knowledge, skills in calculating mechanisms and machines used in transport, automotive and c/c engineering, as well as using reference data and materials of standard terminology. The course project consists of three sheets covering the main sections of the theoretical course.

The course project is carried out on an individual task. The mission of the course project provides for the study of a machine unit, which consists of a motor, a transmission gear mechanism, a working machine, and a cam control mechanism.

Design of cam mechanism

The widespread use of cam mechanisms is due to the fact that they easily reproduce the given law of motion of the driven link.

It should be borne in mind that when choosing the law of movement of the slave link, impacts in the cam mechanism may occur. The following groups of laws of movement are distinguished: with hard blows, with soft blows, without blows. Hard impacts in the cam mechanism occur when the pusher is lifted or lowered at a constant speed. With a sinusoidal law, movement occurs without hard and soft impacts (this law is recommended when designing high-speed cam mechanisms).

For the synthesis (design) of the cam mechanism, the following are specified: mechanism diagram; Maximum linear h or angular movement of the slave link; phase angles of rotation of a cam (removals - ϕу, distant standing ϕд. page, returns ϕв); Exit laws for the removal and return phase length of rocker arm l for rocker cam mechanisms. Based on the conditions of limiting the pressure angle, the main dimensions of the links of the cam mechanism are determined; minimum radius of cam, position of rocker relative to center of cam rotation, cam profile is designed by graphical or analytical methods.

Conclusion

During the course project, the skills of research and design of mechanisms and machines, use of reference literature were obtained.

During execution of the first sheet structural and kinematic analysis of the mechanism is performed.

When making the second sheet, reactions in kinematic pairs and values of balancing forces are determined.

During the execution of the third sheet, the following tasks were completed:

- calculation of gearing geometrical dimensions;

- determination of the coefficient of overlap of specific slips;