41.What is the fit characteristic when the fundamental deviation of the axis is m?
Answer: belong to transition fit, average is to have small transition fit.Suitable for it4i-t7, assembled with hammer or press, usually recommended for tight assembly.H6/n5 fit is interference fit.
42.What is the fit characteristic when the fundamental deviation of the axis is n?
A: it is a transition fit, the average interference ratio of m axis is a little larger, rarely get clearance, suitable for it4-it7, with hammer or press assembly, usually recommended for tight assembly.H6/n5 fit is interference fit.
43.What is the fit characteristic when the fundamental deviation of the axis is p?
Answer: it is interference fit, interference fit with H6 or H7, transition fit with H8 hole.For non-ferrous parts, it is a lighter pressing fit and easy to disassemble when needed.For steel, cast iron or copper, steel assembly is a standard press fit.
44.What is the fit characteristic when the fundamental deviation of the axis is r?
Answer: belong to interference fit, for iron parts for medium fit, for non-iron parts, for light driving fit, when needed can be removed.When the diameter is over 100mm, it is interference fit; when the diameter is smaller, it is transition fit.
45.What is the fit characteristic when the fundamental deviation of the axis is s?
A: interference fit, for permanent and semi-permanent assembly of steel and iron parts.A considerable amount of binding force can be produced.When using an elastic material, such as a light alloy, the mating property is comparable to that of the p-axis of an iron part.For example, sleeve ring pressure mounted on the shaft, seat, etc.When the size is large, in order to avoid damage to the matching surface, it is necessary to have thermal expansion or cold contraction assembly.
46.The fundamental deviation of the axis is t;U;V.X;Y;What is the fit property at z?
Answer: belong to interference fit, interference amount increases in turn, generally not recommended.
47.When to choose the base shaft system?
A: the shaft is directly made of cold drawn steel with a certain tolerance grade (generally grade 8 to 11) and not machined according to the tolerance band of the reference shaft.At this time, different hole tolerance zone positions can be selected to form a variety of different matching requirements.In agricultural machinery and textile machinery, this situation is more.
Machining size less than 1mm precision shaft than processing the same level of hole is much more difficult, so in instrument manufacturing, watch and clock production, radio and electronics industry, usually used after the smooth rolling forming of the thin wire directly do shaft, then choose the base shaft system with better economic benefits than the base hole system.
Considering from the structure, the Mondays root shaft is matched with several holes in different parts, and each has different matching requirements. At this time, the base shaft system should be considered.
48.How does it fit with standard parts?
Answer: if cooperate with standard part, should decide to cooperate with system with standard part as datum part.For example, in the support structure of the rolling bearing, the outer ring of the rolling bearing and the box hole shall adopt the base shaft system, the inner ring of the bearing and the shaft journal shall adopt the base hole system, the box hole shall be made by J7, and the shaft journal shall be made by k6.
49.What is the tolerance level for the grinding process?
Answer: should take IT1 ~ IT5.
50.What is the tolerance level for the grinding process?
Answer: should take IT4 ~ IT7.
51.What is the tolerance level for diamond machining?
Answer: should take IT5 ~ IT7.
52.What is the tolerance level for diamond boring machining method?
Answer: should take IT5 ~ IT7.
53.What is the tolerance level for circular grinding?
Answer: should take IT5 ~ IT8.
54.What range of tolerance should be taken for flat grinding process?
Answer: should take IT5 ~ IT8.
55.What is the tolerance level for broaching process?
Answer: should take IT5 ~ IT8.
56.Fine car fine boring method, should take tolerance level what range?
Answer: should take IT7 ~ IT9.
57.What is the tolerance level for reaming?
Answer: should take IT6 ~ IT10.
58.Milling processing method, what should be the tolerance level range?
Answer: should take IT8 ~ IT11.
59.Planer, insert machining method, should take what range of tolerance level?
Answer: should take IT10 ~ IT11.
60.What is the tolerance level for rolling and extrusion process?
Answer: should take IT10 ~ IT11.