Boots – shoes – and leggings
Patent
1994-04-07
1996-04-16
Cosimano, Edward R.
Boots, shoes, and leggings
33519, 33546, 33551, 335582, 364506, G01B 520
Patent
active
055089445
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The invention relates to an apparatus for checking geometric and dimensional characteristics of a shaft with cams, comprising a support structure with elements for the support and the mechanical reference of the shaft that define a longitudinal geometric axis, drive means, checking means, coupled to the support structure, comprising first checking elements adapted to cooperate with the outer surface of the cams and providing signals responsive to the radial dimensions of the cams, scanning means, and a memorizing, processing and display unit, connected to the checking means and to the scanning means, for processing said signals responsive to the radial dimensions of the cams.
The invention also relates to a method for checking the features of a shaft with cams, in particular parameters regarding the profiles of the cams, by means of an apparatus with checking elements, comprising the steps of generating mutual rotational displacements between the shaft and the checking elements, detecting, in the course of the rotation, by means of first checking elements, measurement values relating to the radial dimensions of the shaft that define actual profiles of said cams, and calculating values of deviation between the measurement values and the values of corresponding nominal profiles, for checking said parameters.
BACKGROUND ART
Among the dimensional inspections that are normally carried out on a camshaft for an internal combustion engine, in addition to the simple dimensional and geometric characteristics of the main journals and the cams, nowadays there are also those for checking other parameters of the cam profile as, for example, the slope and the slope variations of the profile. Inaccurate values of these parameters may, in fact, affect the running of the engine where the shaft is fitted, and cause, in particular, the improper opening and/or closing of the associated valves. In turn this may produce, for example, violent impacts between valves and valve seats, thereby causing noise, wear and damage to the valves and/or the detrimental-emission of combustion components and consequently the dispersion of pollutants into the atmosphere.
In order to be in a position to fully evaluate the above parameters, it is necessary to gain information pertaining to the profile trend of each cam.
A method and a device for measuring the profile of a cam are disclosed in British patent GB-A-1273479, wherein the radial dimensions of a cam placed in rotation are measured at specific angular positions and a suitable device controls the comparison made between measured values and corresponding desired values. The angular position of the cam with respect to a theoretical cam having the desired values is determined at first on the basis of a comparison, not described in detail, between a desired and a measured value.
In order to determine with greater accuracy the angular position of a cam there are also known devices as those described in British patent GB-A-1320929 and U.S. Pat. No. 3,731,386 wherein the angular position of the lobe of a cam is determined by employing one or more transducers to scan the profile of the cam and processing the signals so obtained. This way of operating may lead to inexact evaluations as it bases itself on not very sophisticated processings of data that result from measurement of a profile to be checked and therefore are presumably affected by error.
Thus the aforementioned methods and devices do not guarantee a precise measurement of a cam profile, and do not enable a rapid and strictly accurate inspection of an entire camshaft.
Another known method for checking the profile of a cam of a camshaft is described and illustrated in English patent application GB-A-2148007. While the shaft is axially rotated, signals relating to radial dimensions of the cam and signals relating to the angular position of the cam are sent in a continuous way to a processor unit that matches the values of one and the other type and compares these values with known nominal values of the cam profile. Befor
REFERENCES:
patent: 3234655 (1966-02-01), Skeels et al.
patent: 3269257 (1966-08-01), Hoglund
patent: 3532863 (1970-10-01), Enslein et al.
patent: 3731386 (1973-05-01), Kreiensen et al.
patent: 3805036 (1974-04-01), Michaud et al.
patent: 4622756 (1986-11-01), Marsden
patent: 5140534 (1992-08-01), Miller et al.
Cosimano Edward R.
Marposs S.p.A.
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