HEATABLE DEVICE

DISPOSITIF CHAUFFABLE

English Abstract

The invention provides a heatable device (1) in the form of a flange adapted
to be inserted in the inlet manifold of an internal combustion engine between
the throttle valve (11) and the inlet manifold (12). The device is provided
with an integrated heating element such as a PTC element (3) or helical
resistance wire (5) to reduce the formation of ice on the throttle valve in
addition to the standard heating. The device is particularly suitable for
retro-fitting.

French Abstract

Cette invention se rapporte à un dispositif chauffable (1) se présentant sous la forme d'une bride et conçu pour être inséré dans le collecteur d'admission d'un moteur à combustion interne entre le papillon des gaz (11) et le collecteur d'admission (12). Ce dispositif comporte, en plus des moyens chauffants standards, un élément chauffant intégré tel qu'un élément PTC (3) ou un fil de résistance hélicoïdal (5) servant à réduire la formation de givre sur le papillon des gaz. Ce dispositif est particulièrement conçut pour être monté en rattrapage.

Claims

6
Claims
1. A heatable device (1) adapted to provide a source
of heat far reducing ice build up on a gas flow throttle
valve (11) and in an inlet tract (10) of an internal
combustion engine, the heating element being outside the gas
flow path through the tract, wherein the device is adapted
to be located adjacent to the gas flow throttle valve (11)
in an inlet tract (10), wherein
the dimensions of the device (1) are such that substantially
no adjustment of the position of the throttle valve (11)
relative to an inlet manifold part (12) of the tract (10) is
necessary to insert the device and the device is actuated
for a pre-determined time after starting the engine or after
actuation of the vehicle electrical system,
characterised in that
in addition to the heating element, the device comprises a
control (9) in the form of an integrated switch and an
integrated temperature sensor (3,5,9).
2. A heatable device according to Claim 1, wherein
the source of heat is a PTC element (3) integral with the
device.
3. A heatable device according to Claim 1 or Claim 2,
wherein the device is provided with a groove (4) extending
around the device, the source of heat being a heating
element (5) located in said groove.
4. A heatable device according to any one of Claims
1 to 3, wherein said heating element has substantially the
form of a helical resistance wire (5), wherein in the area
of bores (2a,2b) for connecting screws for connecting the
device to the tract the heating element is straight.
5. A heatable device according to Claim 1, wherein
the energy supply for the device (1) is taken from the

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vehicle flattery (8).
6. A heatable device according to Claim 1, wherein
the energy supply has a single pole.
7. A heatable device according to Claim 1, wherein
the device is located in the throttle valve housing.

Description

CA 02272899 1999-OS-25
WO 98/23857 PCT/IB97/01478
Heatable Device
. The invention relates to a heatable device adapted to
be located adjacent to a gas flow throttle valve in a fuel
inlet tract of an internal combustion engine.
The formation of ice on the throttle valve of the
engine of a motor vehicle is a well known problem,
particularly in countries where extremely cold and damp
conditions occur. If ice forms on the throttle valve, the
correct motion of this is impaired, which can in extreme
cases lead to a loss of control of the vehicle.
It has long been known to heat either the inlet tract
(e. g. DE 3917107) or even the spindle of the throttle valve
itself (e.g. DE 4122138) by various means such as using PTC
elements (e. g. EP 0138315) or other heating elements (e. g.
DE 3426469).
It has also been proposed (GB 863257) to provide a
gasket adapted to replace a gasket between the carburettor
and inlet manifold having a heating element located in a
recess in the gasket. The device is relatively crude and
suffers from the problem that the vehicle battery is rapidly
drained on use. This device suffers from the further
problem that it is not suitable for retrofitting.
The above solutions generally achieve their purpose but
suffer from design compromises such as restricting the cross
sectional area of the fuel flow path or being fairly bulky.
Additionally the known devices still do not work
satisfactorily under the most extreme conditions, such as in
Canada and the Scandinavian countries, or are expensive so
that they are not economic to use on mass production
vehicles.
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CA 02272899 1999-OS-25
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The-.~lresent invention seeks to provide a device to reduce or
prevent the build up of ice on the throttle valve and inlet
manifold that is compact, cheap to manufacture and can be
easily retro-fitted to vehicles in countries where it is
appropriate.
According to the present invention there is provided
a heatable device adapted to provide a source of heat for
reducing ice build up on a gas flow throttle valve and in an
inlet tract of an internal combustion engine, the. heating
element being outside the gas flow path through the tract,
wherein the device is adapted to be located adjacent to the
gas flow throttle valve in an inlet tract, wherein the
dimensions of the device are such that substantially no
adjustment of the position of the throttle valve relative to
an inlet manifold part o~ the tract is necessary to insert
the device and the device is actuated for a pre-determined
time after starting the engine or after actuation of the
vehicle electrical system, characterised in that in addition
to the heating element, the device comprises a control in
the form of an integrated switch and an integrated
temperature sensor.
The solution according to the invention has the advantage
that the device can be retro-fitted by dealers in the
countries where extreme icing is a problem which is not
satisfactorily solved by the normal inlet manifold heating
arrangements. Alternatively it rnay be fitted on the
production line to vehicles destined for those countries
without any design modifications being necessary or
increasing product assembly time or costs. A further
advantage of the invention is that by placing the heating
element outside the inner wall of the inlet tract, the gas
flow through the tract is not impaired at any stage. In a
preferred embodiment the device is adapted to be inserted
adjacent to the gas flow throttle valve. Preferably, the
source of heat is a PTC element
AMENDED SHEET

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integral with the device. Alternatively the device may be
provided with a groove extending around the device, the
source of heat being a heating element located in said
groove. Preferably said heating element is a helical
resistance wire. However, in the area of bores for
connecting screws for connecting the device to the tract the
heating element may be straight.
Preferably the dimensions of the device are such that
substantially no adjustment of the position of the throttle
valve relative to an inlet manifold part of the tract is
necessary to insert the device.
Preferably the energy supply for the heating element is
taken from the vehicle battery. The energy supply may have
a single pole.
Embodiments of the invention will now be described by
way of example with reference to the drawings in which:
Figure 1 shows the device of the invention in-situ;
Figure 2 shows a flange-like insert with an integral
PTC element and
Figure 3 shows a flange-like insert with a channel
containing a heating element.
Figure 1 schematically shows a part of an internal
combustion engine having the device of the invention. The
device 1 is located between the part of the inlet tract 10
of an internal combustion engine 14 having the throttle
valve 11 and the inlet manifold 12. A thermally conducting
gasket l3a,b is placed on both sides of the device 1 to act
as the seal between the device 1 and the inlet manifold 12
and the inlet tract 10 having the throttle valve 11. The
gasket l3a,b thus enables heating of the throttle valve
housing. The device 1 is fairly thin in the longitudinal
axis of the tract so that it may be inserted into the inlet

CA 02272899 1999-OS-25
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tract between the throttle valve and the inlet manifold
without requiring any substantial adjustment work on or
repositioning of these two parts. The electrical supply for
the device 1 is taken from the vehicle battery 8.
The device shown in full lines in figure 1 is
particularly suitable for retro-fitting. Alternative
arrangements are shown in broken lines in figure 1 where the
heating element is located directly in the housinq_ of the
throttle valve 11 or also upstream of the throttle valve.
Figure 2 shows the flange-like device 1 which is
essentially annular with four equidistant regions of
enhanced diameter, which regions have bores 2a-d to receive
the screws joining the throttle valve to the inlet manifold.
A PTC heating element 3 of known type is integrally joined
to the device 1 adjacent to the bore 2a. The PTC element
provides a localised heating to the inlet tract in the
region of the throttle valve. A thermally conducting gasket
is applied to the surface of the device 1 adjacent to the
throttle valve to ensure that the heat provided by the PTC
element is conducted around the inlet tract. The electrical
supply to the PTC element is taken from the vehicle battery
8.
Figure 3 shows an alternative embodiment of the device
1 having four bores 2a-d and a groove 4 extending around the
circumference of the device 1. A heating element 5, such as
helical resistance wire, for resistance heating_runs around
the groove 4. A thermally conducting gasket is then applied
on top of the groove. Between bores 2a and 2b the device 1
has a slightly larger diameter with respect to the remaining
ring-like structure and a recess 6 larger than groove 4 for
receiving the electrical supply and control device for the
heating element. The electrical supply is taken from the
vehicle battery 8 via a single pole, the earth pole being
provided by a mass 7 located in the recess 6.

CA 02272899 1999-OS-25
WO 98/23857 PCT/IB97/01478
The control device 9 is integrated into the PTC element
3 or in the recess 6 functions independently of any control
devices already on the vehicle and thus is particularly
suitable for the retro-fit market. A semi-conductor switch
element, such as a high side switch, is integrated into the
control device 9. A temperature sensor is integrated into
either the control device 9 or the heating element 3,5
itself. In addition the high side switch contributes to the
heating. When the temperature in the inlet tract is below
a certain pre-determined level, when ice could form, then
upon engine actuation ors-- alternatively, when there is any
actuation of the vehicle electrical system the switch will
actuate the heating element. It is also possible to limit
the time that the device operates. This control of the
actuation of the device prevents draining the battery or
reduction of the fuel consumption. Although the device is
shown here between the throttle valve and the inlet
manifold, it could also be placed on the side of the valve
remote from the manifold, if the inlet tract construction
was suitable.
The device of. the invention presents a low cost
solution suitable for the limited markets where the
situation will occur. Due to its small size the device of
the invention can be retro-fitted with only minor
modifications, at most, to the inlet tract. Hy integrating
the switching and temperature controls in the device,
reliability is enhanced and a compact size achieved.

Representative Drawing