US 2018/0272513 A1Published application

Extraction process of a glow plug pencil for a motor vehicle and the tooling set for the implementation of such a process

AssigneeHubitools S.A.

InventorYannick Dudot

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Abstract

The invention involves the extraction process of a glow plug pencil (23) or a broken pencil (23) which is stuck in a cylinder head (13) housing (11) of a glow plug engine comprising a lower (19) and upper (17) part, so that the upper part (17) forms a shoulder (21) with the lower part (19), the pencil (23) being stuck in the lower part (19). The process is remarkable in that it includes a step (a) for drilling a bore in the pencil (23) according to the longitudinal direction of the latter which is performed with the use of a drill bit (1) comprising a drilling part (5) with flutes (7) and a shank (3) respectively having a diameter smaller and greater than the lower part diameter (19) of the housing (11) so that the shank (3) forms a shoulder (9) with the drilling part (5), and in that step a) for drilling the bore includes the drilling of the pencil (23) until the said shoulder (9) of the drill bit (1) is positioned to a stop against the shoulder (21) of the housing (11).

Claims10

Dependent claims

Extraction process for a glow plug pencil or a broken pencil which is stuck in a glow plug housing comprising a lower and upper part, the upper one with a diameter greater than the lower part diameter so that the housing features a shoulder the pencil being stuck in the lower part of the plug housing, the process comprising the following steps:

a) drilling a bore in the pencil according to the longitudinal direction of the latter with a drill bit comprising a drilling part with flutes and a shank, the drilling part having an inner diameter smaller than a pencil diameter;
b) forming a thread in the bore drilled at step a) in the pencil using a tap, the tap with having a tapping part with at least a flute and at least a comb and a tap shank, the tapping part has a diameter greater than the bore and smaller than the pencil diameter;
c) screwing an extractor in the thread, the extractor having a threaded head through which the latter is screwed on the pencil and located on one of extractor shank ends;
d) extracting the pencil by removing the extractor screwed in the pencil,
wherein the drill bit (1) is selected so that the drill bit shank (3) has a diameter greater than the diameter of the drilling part so that the drill bit includes a second shoulder, and the diameter of the lower part of the plug housing, and in that step a) for the drilling of the bore includes the drilling of the pencil until the second shoulder of the drill bit is positioned to a stop against the first shoulder of the glow plug housing.

2 more elements

A tool set for the implementation of the extraction process for a glow plug pencil, this stuck in a glow plug housing comprising a lower and upper parts, this lower part has a predetermined diameter “d”, the pencil being stuck in the said lower part, the tool set includes at least a drill bit with a drilling part and a shank, the shank has a diameter greater than the drilling part diameter related to the drill bit so that the drill bit has a shoulder and is selected with a diameter greater than the diameter related to the lower part of the plug housing, and in that the tool set also includes one or several elements selected from among:

at least a tap for threading the bore of the pencil;
at least an extractor for extracting the pencil;
a sledge hammer to remove the extractor;
a push bar to expel the pencil;
a collector to retrieve the pencil in a combustion chamber;
and
at least a centering device for positioning and guiding one or several elements selected from among:
a drill bit during the boring operation of the pencil;
a tap during the thread operation of the bore;
an extractor when screwing the latter in the thread of the pencil;
a push bar during the driving out operation of the pencil.

8 more elements

Dependencies are inferred from the claim text.