Thesis-1982-daSilva.pdf (6.62 MB)
An investigation relating to the design parameters of diaphragm mandrels
educational resource
posted on 2017-08-23, 14:29 authored by J. C. L. F. da SilvaThe aim of the present investigation was to establish the equations relating the deformations and the gripping pressure of diaphragm mandrels, as well
as to simplify them, enabling their utilization by a designer.
Diaphragm mandrels, to be used in lathe or finishing machining work, can be seen as revolution pieces constituted of an assemblage of elastic elements disposed around their revolution axis. The centering and gripping operations rely
only on the elastic forces generated when those elements are elasticly deformed.
The non-existence of metalic sliding parts distinguishes this type of mandrels
from the usual types and assures an high degree of repeatability and accuracy during
the machining operations.
Four fundamental stages constitute the present work. Firstly, the preliminary
design of the geometrical shape for the diaphragm mandrels has been developed in chapter 2. The second and third fundamental stages have been undertaken simultaneously. They are constituted of an theoretical and experimental analysis
in view to obtain the equations earlier refered. This analysis has been undertaken firstly on two different types of Specimen, simulating the constituting
elements of a diaphragm mandrel and finally on a third Specimen simulating an actual
section of the mandrel. The first Specimen simulated the tapered parts of
the mandrel, and the second type simulated the assemblage of those tapered parts
and the holding part in between them. On pages 42, 71 and 126 are represented
the first, the second and the third type of those Specimen, respectively. In chapter 3 is elaborated the theoretical analysis of the first type, in chapter 7 the
second type and in chapter 11 the third type. Their experimental analysis is
presented on chapter 4, 5 and 6 for the first type, on chapters 8, 9 and 10 for
the second one and on the chapter 12, 13 and 14 for the third type. The theoretical analysis, based upon the energy method enabled the calculations of deformations,
load forces and gripping pressure relationships, and from the experimental
work the experimental values have been obtained and used to verify the accuracy
of the theoretical analysis. Mechanical and electronic techniques have been used
during the experiments and close correlation between the predicted results and
the experimental ones have been obtained, this being stated in chapter 6, chapter
10 and chapter 14.
Finally the third stage of this investigation has been related with the
simplification of the theoretical expressions and their presentation in a tabled
way providing their use by a designer to characterize the behaviour of a mandrel
as well as to define its geometrical dimensions under a specific work situation,
chapter 17 and 18.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Rights holder
© J. C. L. Ferreira da SilvaPublisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
1982Notes
A Masters Dissertation, submitted in partial fulfilment of the requirements of the award of Master of Science of Loughborough University.Language
- en
Qualification name
- MSc
Qualification level
- Masters