2.7. Designing details.
2.7.1, General Demands on Designing of Details of Agricultural Machinery.
Details of agricultural machinery can be produced in different ways. In order to fulfill the required function, a detail is to be produced of a corresponding material and to possess a definite shape. That's why choice of material and ways of its machining for production of a detail is a united task.
Specifying variants for a designed detail production, probable cost of each one should be estimated. Cost, first of all, depends upon material, production, accuracy and clearness of surface. That's why, firstly, details shouldn't be produced more accurately and cleaner, than it is required, and secondly, it is always necessary to seek for shortening of measuring circuits (for example, by means of its breakage), as it allows to use more accurate its with the same sum of tolerances.
In spite of diversity of materials, used in agricultural machine building, metals are still staying the main components of construction. Now material utilization factor (MUF) in agricultural machine building exists in the limits 0,8-0,85.Taking into account the immense volume of production of agricultural machinery in our country, it is evident that value MUF must be constantly increased. It means that, first of all, the technologies, giving minimum waste of metal and reducing machining of details, are to be used. First of all these are different kinds of casting.
Translate the following words.
Possess, definite shape, choice of material, ways, machining, estimated, cost, accuracy, clearness, surface, firstly, accurately and cleaner, seek for, fits, tolerances, diversity, staying the main components, it is evident, waste of metal, reducing machines of details, kinds of casting.
Find English counterparts for the following word combinations and memorize them :
Сельскохозяйственные машины, функция, укорочение, размерные цепи, разнообразие, основные компоненты, предел, объем производства, минимальный отход, различные виды литья.
Questions to the text:
1.Why is the choice of material and ways of its machining for trie
production of a detail a united task?
2.Why shouldn't details be produced more accurately and cleaner
than it is required?
3.What does the shortening of measuring circuits allow?
4.Why must the value of MUF be constantly increased in the pro
duction of the agricultural machinery?
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