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Tillämpning av klämkraftsmätning på kritiska förband inom produktion

Holm, Rickard and Johansson, Thomas (2009) In Examensarbete
Machine Elements
Abstract
Title: Elongation controlled tightening
Authors: Rickard Holm and Thomas Johansson
Supervisors: Magnus Danielson, Head of DEMD, Scania CV AB
Tor Ronnholm – Quality Technician, DEMD, Scania CV AB
Unto Ojaniemi – Quality Engineer, DEMD, Scania CV AB
Problem Discussion: Within Scania’s engine assembling the engines are assembled,
tested and painted. Based on the customers increased demands
on higher power and torque, longer service life, experienced
quality and decreasing of weight Scania increases their
demands on their engines. The most frequently used method
of assembling engines is using screw joints. To be able to
optimize the screw joints based on weight, service life etc. the
tightening of the screws has to result in the... (More)
Title: Elongation controlled tightening
Authors: Rickard Holm and Thomas Johansson
Supervisors: Magnus Danielson, Head of DEMD, Scania CV AB
Tor Ronnholm – Quality Technician, DEMD, Scania CV AB
Unto Ojaniemi – Quality Engineer, DEMD, Scania CV AB
Problem Discussion: Within Scania’s engine assembling the engines are assembled,
tested and painted. Based on the customers increased demands
on higher power and torque, longer service life, experienced
quality and decreasing of weight Scania increases their
demands on their engines. The most frequently used method
of assembling engines is using screw joints. To be able to
optimize the screw joints based on weight, service life etc. the
tightening of the screws has to result in the right amount of
preload. Since most of the tightenings presently is based on
the friction, the scatter of the preload can be very large. A
method of more accurately determining the preload is to
measure its elongation when the screw is loaded. Based on
this, the preload can be calculated. The great advantage of this
method is that it’s completely independent of the friction
between the screw and the clamped parts, the effect of gaskets
etc.
Purpose: The purpose of the master thesis is to investigate the ultrasonic
technique and its potential in production; the affecting factors,
under what conditions the technique can be used and the
reliability of the measurements. Another purpose is to evoke
an interest of the technique at the companies who makes
tightening equipments.
Methodology: The thesis is divided into four parts. The first part is dedicated
to understand the technology and build up a knowledge base
for the authors. This will be done partly by doing theoretical
studies and partly by doing practical studies with the
equipment that Scania has got. The second part is dedicated to
gather information and benchmarking, to see what equipment
and knowledge is available in the area, both within and outside
of Scania. In the third part, a pilot will be built up to be able to
test tightening equipments controlled by the elongation. The
fourth part is devoted to evaluation and analyzing of the
results from the third part.
Tillampning av klamkraftsmatning pa kritiska forband inom produktion
IV
Conclusions: The technique of elongation controlled tightening will, when
used in production; reduce the spread of preload in screw
joints. This results in both lower material and assembling costs
depending on the more optimized joint. The optimization leads
to usage of smaller bolts and weight being saved. The
technique also leads to less need of control after tightening
because the previously used control parameters can be used as
checking parameters. (Less)
Please use this url to cite or link to this publication:
author
Holm, Rickard and Johansson, Thomas
supervisor
organization
alternative title
Elongation controlled tightening
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Elongation controlled tightening, Clamp force, Preload, Ultrasound, Screw joints, Scania
publication/series
Examensarbete
language
Swedish
id
1734861
date added to LUP
2010-12-02 16:15:33
date last changed
2010-12-02 16:15:33
@misc{1734861,
  abstract     = {Title: Elongation controlled tightening
Authors: Rickard Holm and Thomas Johansson
Supervisors: Magnus Danielson, Head of DEMD, Scania CV AB
Tor Ronnholm – Quality Technician, DEMD, Scania CV AB
Unto Ojaniemi – Quality Engineer, DEMD, Scania CV AB
Problem Discussion: Within Scania’s engine assembling the engines are assembled,
tested and painted. Based on the customers increased demands
on higher power and torque, longer service life, experienced
quality and decreasing of weight Scania increases their
demands on their engines. The most frequently used method
of assembling engines is using screw joints. To be able to
optimize the screw joints based on weight, service life etc. the
tightening of the screws has to result in the right amount of
preload. Since most of the tightenings presently is based on
the friction, the scatter of the preload can be very large. A
method of more accurately determining the preload is to
measure its elongation when the screw is loaded. Based on
this, the preload can be calculated. The great advantage of this
method is that it’s completely independent of the friction
between the screw and the clamped parts, the effect of gaskets
etc.
Purpose: The purpose of the master thesis is to investigate the ultrasonic
technique and its potential in production; the affecting factors,
under what conditions the technique can be used and the
reliability of the measurements. Another purpose is to evoke
an interest of the technique at the companies who makes
tightening equipments.
Methodology: The thesis is divided into four parts. The first part is dedicated
to understand the technology and build up a knowledge base
for the authors. This will be done partly by doing theoretical
studies and partly by doing practical studies with the
equipment that Scania has got. The second part is dedicated to
gather information and benchmarking, to see what equipment
and knowledge is available in the area, both within and outside
of Scania. In the third part, a pilot will be built up to be able to
test tightening equipments controlled by the elongation. The
fourth part is devoted to evaluation and analyzing of the
results from the third part.
Tillampning av klamkraftsmatning pa kritiska forband inom produktion
IV
Conclusions: The technique of elongation controlled tightening will, when
used in production; reduce the spread of preload in screw
joints. This results in both lower material and assembling costs
depending on the more optimized joint. The optimization leads
to usage of smaller bolts and weight being saved. The
technique also leads to less need of control after tightening
because the previously used control parameters can be used as
checking parameters.},
  author       = {Holm, Rickard and Johansson, Thomas},
  keyword      = {Elongation
controlled tightening,Clamp force,Preload,Ultrasound,Screw joints,Scania
},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbete},
  title        = {Tillämpning av klämkraftsmätning på kritiska förband inom produktion},
  year         = {2009},
}