Попередньо розгорнутий або розточений отвір хонінгують спеціальною обертовою обернено-поступальною рухливою головкою з шістьома або більше хонінгувальними роздвижними брусками.
В результаті хонінгування отримується гладка і блискуча поверхня з точністю 6...7 квалітету.
Охолодження проводиться керосином, який сприяє видаленню абразивних зерен.
Верстати для хонінгування 3820; 3821; 3822 одно- і багатошпіндельні.
Переваги хонінгування в порівнянні з внутрішнім шліфуванням :
1) Обробка складних заготовок ( блоки циліндрів двигунів) ;
2) Легше досягається правильна циліндрична поверхня отвору, так як відсутній віджим інструмента, вібрація.
Недоліки - неможна видалити відхилення положення і напряму вісі отвору. Точність форми - 0,01...0,02мм для отвору діаметром 100...120мм.
Припуск на обробку - 0,5...0,1мм може бути знятий за 1...2хв.
Хонінгувальна головка обертається із швидкістю 60...75 м/хв при обробці заготовок із сталі.
Швидкість зворотно-поступального руху головки 12...15 м/хв. Хонінгувальні бруски виготовляють із абразивних матеріалів:
- електро корунда;
- карбіда кремнія ;
- ельбора (кубічного нітриду бора);
- синтетичних алмазів.
The term lexicology is composed of two Greek morphemes: “legis” (word) and “logos” (learning). Thus, the literal meaning of the term “lexicilogy” is “the study of words”.
There is general lexicology and special lexicology. General lexicology studies vocabulary in different languages of the world. Special lexicology studies the vocabulary of one language.
There is also historical lexicology and descriptive lexicology. Historical lexicology studies the changes of the vocabulary in the course of time. Descriptive lexicology studies the vocabulary at a given stage of its development. Historical lexicology uses the diachronic approach to the vocabulary, it focuses on the regularities of the development of the vocabulary. Descriptive lexicology uses the synchronic approach to the vocabulary; it describes the principles of the organization of the vocabulary as a system.
There also exist comparative lexicology, which studies the lexical systems of closely related languages aiming at their typological [ai] identity or differentiation; contrastive lexicology, which studies similarities and differences of related and non-related languages; and applied lexicology, which includes terminology and lexicography, translation, linguodidactics [i] and pragmatics of speech.
Lexicology is connected with other subjects such as phonetics, grammar, stylistics and history of the language. All these subjects study the word, but from different angles. Phonetics studies the sounds that make up a word. Grammar studies the use of words in speech. Stylistics studies the use of words in different situations: formal and informal. The history of the language tells about the development of words in different periods of their history: how the words changed – lost their endings, began to sound differently; it tells about the change of the phonetical and grammatical structure of the language.
Thus, in studying the word “information” the phonetician will investigate the phonemes that make up the phonetic shape of the word and the distribution of the stress (in-for-ma-tion – 4 syllables).
The grammarian will point out the part of speech to which the word “information” belongs (the noun) and the fact that this noun has no plural and genetive case forms and is followed by a verb in the singular (The information is important).
The lexicologist will state that the word consists of two morphemes: one root and one affixational morpheme, that it is built by affixation (the suffix “tion” is added to the stem “inform”), that it is a borrowing – the morphemes are of Romanic origin, that it is polysemantic, having (at least) 5 meanings: 1) communication of knowledge; 2) knowledge; 3) the act of informing against a person; 4) (a term in jurisdiction) a formal accusation of a crime; 5) a numerical quantity that measures the uncertainty in the outcome of the experiment to be performed. The first meaning is the primary meaning, the rest are secondary meanings. In the second meaning – knowledge obtained from investigation, study or instruction – it has synonyms: intelligence, news, facts, data.
The stylist will state the fact that the word is referred to the neutral layer of words, and is distinguished from its synonyms – “knowledge”, “learning”, “science”.
Lexicology consists of the following parts, or branches:
1. Etymology, which studies the origin of words and the connections of the vocabulary of the given language with the vocabularies of other languages.
2. Word-structure (word-building), which studies the elements the word consists of (morphemes: roots, affixes) and the patterns according to which words are built: affixation, composition, conversion, shortening, sound imitation, etc.
3. Semasiology [meisi], which studies the meaning of words, its types, paradigmatic classifications of words according to meaning (into homonyms, synonyms, antonyms) and types of the change of meaning.
4. Phraseology, which studies phraseological units (set expressions) and their classifications.
5. Lexicography, which deals with creation of dictionaries, their types and application.
Lexicology also studies the stylistic differentiation (stratification) of the vocabulary and variants and dialects of the language.
The methods used in lexicological research are componential analysis, transformational analysis, the contextual method, analysis of dictionary definitions, the statistical method and others. The componential analysis method is concerned with the components the meaning of the word comprises. The method of transformation consists in using one word for another in order to see the likeness or the difference. The contextual method reveals the meaning the word is used in a certain context. But the main method is that of observation of linguistic facts, of the word functioning in written and oral speech.
The basic unit of lexicology is the word. There are many definitions of the word, yet none of them is totally satisfactory. Despite the achievements of modern science, certain aspects of the nature of the word are still not clear to us. We know almost nothing about the mechanism by which a thought is converted into sound groups called words, or about the reverse process when the listener’s brain converts the sounds into thoughts. And yet, the word should be and can be defined, and the definition should be based on the most important characteristics of the word which are as follows:
1. The word is a unit of speech which serves the purposes of human communication. So the word can be defined as a unit of communication.
2. The word is the total of the sounds which compose it.
3. The word possesses both external and internal characteristics.
a) By external structure of the word we mean its morphological structure. For example, in the word “post-impressionists” the following morphemes can be distinguished: the prefixes post-, im-, the root “press”, the noun-forming sufixes –ion, -ist, and the grammatical suffix of plurality –s.
b) By the internal structure is understood the semantic structure of the word, or its meaning. Meaning is the word’s main aspect and it is only due to their meanings that words can serve the purposes of human communication.
c) The word possesses both external, formal and internal, semantic unity.
Formal unity implies that no other elements can be inserted between the component morphemes of the word which are permanently linked together (a blackbird vs a black bird – a black night bird).
The word’s semantic unity consists in the fact that it conveys only one concept. For example, the word “blackbird” conveys only one concept: the type of bird. The word-group “a black bird” conveys two concepts: a colour and a a type of animal.
4. The word can be used in different grammatical forms.
All that has been said about the word can be summed up as follows: the word is a unit used for purposes of human communication, materially representing a group of sounds, possessing a meaning, characterised by formal and semantic unity and a capacity for grammatical employment.