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Our company SMALL HOLE DRILLING Ltd. in cooperation with the Technical university of Liberec – Department Vehicles and Engines  has successfully participated in research – ( November 2012 ) for the structural optimization in the design of spark plugs.

 

Title: adjustment in the classic case of spark plug for temperature measurement – drilling deep holes of very small diameter

 

Subject: drilling holes of a diameter of 0,46 mm ( drilling depth 22,4 mm, blind hole ). Drilling holes of diameter 0,46 mm for focusing temperature in the lower most part of the spark plug housing.

In the case of spark plug were drilled two holes ( circumferentially opposite ) into which were placed sheathed thermocouples ( diameter of thermocouples is 0,25 mm ). After creating two small holes diameter 0,46 mm were drilled two holes inclined at an angle of 18  degrees to bring two wires of thermocouples in.

The following is the final installation of the spark plug  ( mounting insulator with the central electrode ). 
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Brief description:

» deep hole drilling classic spark plug 

» fabrication of planar surfaces inside part of the spark plug

» microdrilling hole of diameter 0,46 mm ( drilling depth 22,4 mm, blind hole ) 

» drilling hole – diameter 1,1 mm

 

Title: adjustment chamber spark plug for temperature measurement – drilling deep holes of very small diameter

 

Brief description:
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» deep hole drilling chamber spark plug 

» fabrication of planar surfaces inside part of the chamber spark plug 

» microdrilling hole of diameter 0,46 mm ( drilling depth 25,5 mm, blind hole )

» drilling hole – diameter 1,1 mm

» welded to the casing bottom TIG welding

» drilling ” flash-out ” oblique holes having a diameter of 1,50 mm, 1,65 mm, 1,80 mm 

 

Effects of temperature measurements in the lowermost part of the spark plug housing , won the Technical University of Liberec reliable data to calibrate the computational modeling of temperature field
in spark plug housing ( especially in the part
at the bottom of the chamber spark plug )
which has been used in structural optimization
design of chamber spark plug.

Currently the production of 40 pieces of functional samples perforated ( chambers ) spark plugs which passed tests on the engine                ( still in testing ).

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Prof. Ing. Stanislav Beroun, PhD.
Technical university of Liberec
Department Vehicles and Engines
Student 2
461 17 Liberec

 

We wish much success!

Team SMALL HOLE DRILLING Ltd.