Product category:
Coordinate measuring machines (CMM) and software
News Release from: Mitutoyo (UK) | Subject: Mitutoyo Euro-C 574 CMM
Edited by the Manufacturingtalk Editorial
Team on 01 April 2002
CMMs check valve clearance before engine
assembly
Three CMMs installed at a motorcycle manufacturer are playing a critical role in the assembly of engine cylinder heads where the correct setting of valve clearances is absolutely essential.
Three Mitutoyo CMMs installed at Triumph Motorcycles are playing a critical role in the assembly of engine cylinder heads where the correct setting of valve clearances is absolutely essential Each head has to be treated individually due to the manufacturing tolerances on each of several mating parts
This article was originally published on Manufacturingtalk on 24 Mar 2005 at 8.00am (UK)
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Traditionally this operation was carried out by an operator assembling the engine cylinder head with standard clearance setting shims.
Sometimes this very time consuming operation had to be repeated as one head can contain 16 valves.
It was realised that if the measurement of the valve clearance could be carried out before the assembly, considerable time could be saved.
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Mitutoyo was consulted concerning possible solutions of the measurement of the valve clearance, before the assembly of the head.
CMM or fixed gauges were identified as two possible solutions but the fixed gauge solution would have would have been very costly.
It was therefore decided to carry out trials to determine if a CMM could achieve the desired result.
Using the Mitutoyo Euro-C 574 CMM with Geopak-Win software, test part programs were produced to measure critical dimensions.
From these dimensions the required 'shim' for each valve was computed by the program and a list produced for assembly.
This exercise showed that the CMM could indeed produce the required information, both quickly and on a repeatable basis.
The fixturing was developed by Mitutoyo's Gauging Technology and Tooling division designing and building a universal locating fixture.
This is placed on the CMM table and can accommodate any of the configurations of engine.
Because the system was to be installed into a factory environment, the PC has a built-in touch screen and Geopak-Win can be fully operated from it.
To date Triumph has built over 10,000 engines using the CMM measured assemblies.
Following assembly, each engine is tested on a dynomometer and to date there has not been one failure due to incorrect valve settings, proving the consistency of using the CMM method.
The complete measurement and insertion of camshaft shims takes an average of six minutes for the four cylinder heads.
This is marginally quicker than the best time previously achieved by an experienced operator using the old method.
However, using the CMM means there is never any need to re-work and quality is assured. Request a free brochure from Mitutoyo (UK) ...
(This was Manufacturingtalk's Top Story on 29 March 2002).
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