U.S. patent application number 10/569220 was filed with the patent office on 2007-04-19 for sheated-element glow plug having a particularly embedded contact element.
Invention is credited to Rainer Bach, Susanne Blank, Andreas Gaiser, Christoph Haluschka, Laurent Jeannel, Alexander Klonczynski, Peter Sossinka.
Application Number | 20070084845 10/569220 |
Document ID | / |
Family ID | 34202148 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070084845 |
Kind Code |
A1 |
Haluschka; Christoph ; et
al. |
April 19, 2007 |
Sheated-element glow plug having a particularly embedded contact
element
Abstract
A sheathed-element glow plug for an internal combustion engine
is described. It includes a plug housing, a connection part for the
electrical current that is situated on the plug housing as well as
a sheathed-element heater, which is usually in the form of a tube
including an embedded heating element. The connecting part and the
heating element are electrically coupled by a terminal pin and a
contact element. The terminal pin and the contact element are at
least partially surrounded within the housing by an electrically
insulating plastic sleeve.
Inventors: |
Haluschka; Christoph;
(Klingenberg, DE) ; Bach; Rainer; (Wiernsheim,
DE) ; Sossinka; Peter; (Ditzingen, DE) ;
Klonczynski; Alexander; (Ludwigsburg, DE) ; Jeannel;
Laurent; (Ditzingen-Hirschlanden, DE) ; Gaiser;
Andreas; (Ingersheim, DE) ; Blank; Susanne;
(Weimstadt, DE) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
34202148 |
Appl. No.: |
10/569220 |
Filed: |
June 23, 2004 |
PCT Filed: |
June 23, 2004 |
PCT NO: |
PCT/DE04/01308 |
371 Date: |
December 4, 2006 |
Current U.S.
Class: |
219/270 |
Current CPC
Class: |
F23Q 7/001 20130101 |
Class at
Publication: |
219/270 |
International
Class: |
F23Q 7/22 20060101
F23Q007/22 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2003 |
DE |
103 39 641.1 |
Claims
1-7. (canceled)
8. A sheathed-element glow plug for an internal combustion engine,
comprising: a plug housing; a connection part for the electrical
current which is situated on the plug housing; a tube having an
embedded heating element, the connection part and the heating
element being electrically coupled via a terminal pin and a contact
element; wherein the terminal pin and the contact element are at
least partially surrounded within the housing by an electrically
insulating plastic sleeve, the contact element having a cylindrical
shape, and wherein a sheathing of the contact element is completely
surrounded by the plastic sleeve.
9. The sheathed-element glow plug of claim 8, wherein the plastic
sleeve is a clamping sleeve.
10. The sheathed-element glow plug of claim 8, wherein the plastic
sleeve has elastic properties.
11. The sheathed-element glow plug of claim 8, wherein the plastic
sleeve is formed from a plurality of pieces.
12. The sheathed-element glow plug of claim 8, wherein the contact
element is elastic.
13. The sheathed-element glow plug of claim 8, wherein the contact
element is a graphite tablet.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a sheathed-element glow
plug for an internal combustion engine made up of a plug housing, a
connection part for the electrical current which is situated on the
plug housing as well as a sheathed-element heater, which is usually
in the form of a tube including an embedded heating element. The
connecting part and the heating element are electrically coupled by
a terminal pin and a contact element.
BACKGROUND INFORMATION
[0002] The contact element together with the terminal pin and the
connection area of the sheathed-element heater in the housing
interior forms the positive contact. Various methods are known from
the related art for securing the contact element within the housing
of the sheathed-element glow plug and insulating it from the
housing.
[0003] Frequently sheathed-element glow plugs having a small
diameter are requested. Since the electrical properties are
predetermined by the sheathed-element heater and the terminal pins,
or their dimensions are predetermined, little space remains between
the terminal pin and housing. The clamping sleeves must therefore
be made using a thin wall, which in the case of ceramic materials
is associated with high manufacturing complexity and costs.
SUMMARY OF THE INVENTION
[0004] The present invention relates in particular to embodiments
in which the contact is produced by an elastic conduction element
such as a graphite tablet. Ceramic clamping sleeves are used in
these embodiments for insulation and fixation. These sleeves
surround the terminal pin and the graphite tablet and thus prevent
contact with the housing. Simultaneously, they keep the contact
element in a defined position, thus ensuring a good contact with
the sheathed-element heater, i.e., the heating element.
[0005] An object of the present invention is to provide a
sheathed-element glow plug having a solidly secured contact
element, it being possible to secure and insulate the contact
element cost-effectively.
[0006] The object may be achieved by surrounding the terminal pin
and the contact element at least partially by an electrically
insulating plastic sleeve within the housing.
[0007] The use of a sleeve, preferably a plastic clamping sleeve,
produces a very simple insulation from the housing. In contrast to
ceramic sleeves, plastic sleeves have the advantage that it is
possible to manufacture them more simply and accordingly more
cost-effectively. This applies in particular to sleeves having thin
walls as is frequently needed in sheathed-element glow plugs.
[0008] Even with thin walls, plastics are capable of producing a
good insulation and are simultaneously robust enough to be able to
withstand additional processing steps. If, for example, a
supporting tube surrounding the housing is bonded to the housing,
which may be accomplished by pressing, swaging, soldering or
welding, often strong forces also act on the plastic sleeve.
[0009] Plastic sleeves may be easily manufactured in various sizes
and shapes. An advantageous embodiment is to manufacture the
plastic sleeve as a clamping sleeve.
[0010] To produce a good contact, the largest possible surfaces of
the contact element must be coupled to the heating element and the
terminal pins. For that reason, a cylindrical shape of the contact
element is provided for a tubular component such as the
sheathed-element glow plug. In order to ensure adequate insulation
from the housing, the plastic sleeve must therefore completely
surround the cylinder sheathing.
[0011] In contrast to ceramic materials, plastics having elastic
properties may also be provided. In one advantageous embodiment,
the plastic sleeve has elasticity in the radial and/or longitudinal
direction. The elasticity increases the robustness of the component
and reduces the probability of fracture during assembly or under
loads during operation.
[0012] The plastic sleeve may be of one piece or, in another
advantageous embodiment, it may also be formed from a plurality of
pieces. The individual parts may then be combined for
sheathed-element glow plugs of different types using the principle
of modularity.
[0013] Additional advantageous embodiments are found in the
description herein.
BRIEF DESCRIPTION OF THE DRAWING
[0014] FIG. 1 Shows a schematic sectional representation of a part
of a sheathed-element glow plug.
DETAILED DESCRIPTION
[0015] The parts of a sheathed-element glow plug 1 on which the
present invention is based are shown in FIG. 1. This
sheathed-element glow plug 1 is made up of a plug housing 2 and a
connection area 3 of a sheathed-element heater 4, which is not
shown in greater detail.
[0016] A terminal pin 5 is provided within housing 2. In order to
produce the electrical contact between terminal pin 5 and
connection area 3 of the heater, a contact element 6 is provided
between these two elements. This contact element is preferably
elastic. A contact element 6 of this type may be, for example, a
graphite tablet.
[0017] In order to secure contact element 6 and insulate the
contact element and terminal pin 5 from housing 2, according to the
present invention, a plastic sleeve 7 is inserted into housing 2,
terminal pin 4 being situated within the plastic sleeve. This
plastic sleeve 7 having a thin wall 8 may be produced simply and
cost-effectively.
[0018] A recess 9 is provided in connection area 3 into which
contact element 6 is at least partially insertable.
[0019] Sleeve 7 is preferably designed to be of one piece. It is
designed as a clamping sleeve and is thus in contact with inside
wall 10 of housing 2.
* * * * *