METHOD FOR SEALING OFF A GAP BETWEEN A THROTTLE VALVE PIVOTABLY MOUNTED IN A THROTTLE VALVE ASSEMBLY AND THROTTLE VALVE ASSEMBLY

PROCEDE PERMETTANT D'ETANCHEIFIER UN ESPACE SITUE ENTRE UN PAPILLON DES GAZ MONTE PIVOTANT DANS UN CARTER ET LEDIT CARTER

English Abstract

The invention relates to a throttle valve connection (1), in which a liquid
sealing mass (7, 8) is exclusively applied to an adjoining zone of a tubular
housing (2) and a throttle valve (3), using a cannula (9). The sealing mass
(7, 8) reaches the zone between the tubular housing (2) and the throttle valve
(3) by capillary force and subsequently hardens. This prevents a wetting of
the surface of the throttle valve (3) by the sealing mass (7, 8).

French Abstract

Procédé qui consiste à déposer une masse d'étanchéité (7, 8) liquide dans un carter (1) de papillon des gaz, à l'aide d'une canule (9), exclusivement dans une zone dans laquelle le papillon des gaz (3) est adjacent à un boîtier (2) tubulaire. La masse d'étanchéité (7, 8) parvient, sous l'effet de forces capillaires, dans la zone située entre le boîtier tubulaire (2) et le papillon des gaz (3), où ladite masse durcit. Une aspersion de masse d'étanchéité (7, 8) sur la surface du papillon des gaz (3) est ainsi évitée.

Claims

6
Claims
1. A method for sealing off a gap between a throttle
valve pivotably mounted in a throttle valve assembly
and a housing of the throttle valve assembly, in which
method the throttle valve is brought into a position
closing the housing and subsequently sealing compound
is introduced into the throttle valve assembly, the
sealing compound being applied in drop form into
regions of the throttle valve and of the housing which
abut one another, in a quantity sufficient for
distribution by means of the capillary forces,
characterized in that the sealing compound is applied
to at least one half of the throttle valve from that
side of the throttle valve which faces away from a
spherical segment.
2. A throttle valve assembly with a throttle valve
pivotably mounted in a tubular housing or housing
having a spherical segment and with a sealing compound
sealing off the throttle valve with respect to the
housing in the closing position, the sealing compound
being disposed solely in a gap between the throttle
valve and the housing, characterized in that the
sealing compound (7, 8) is a slip lacquer containing
molybdenum sulfide or polytetrafluoroethylene.

Description

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Description
Method for sealing off a gap between a throttle valve
pivotably mounted in a throttle valve assembly and
throttle valve assembly
The invention relates to a method for sealing off a gap
between a throttle valve pivotably mounted in a
throttle valve assembly and a tubular housing, or
housing having a spherical segment, of the throttle
valve assembly, said housing having a spherical
segment, in which method the throttle valve is brought
into a position closing the housing and subsequently
sealing compound is introduced into the throttle valve
assembly. The invention relates, furthermore, to a
throttle valve assembly with a throttle valve pivotably
mounted in a tubular housing or housing having a
spherical segment and with a sealing compound sealing
off the throttle valve with respect to the housing in
the closing position.
Throttle valve assemblies of the above type are used in
present-day motor vehicles for regulating a combustion
air stream of an internal combustion engine. In a
method, known from practice, for sealing off a gap
between the throttle valve and the housing, a vacuum is
generated on that side of the throttle valve which is
to be mounted toward the internal combustion engine.
The sealing compound is sprayed into the housing on the
other side of the throttle valve. As a result, leakage
air, which, in the installed state of the throttle
valve assembly, flows past the throttle valve when the
latter is in the closing position, can be reduced to a
minimum.
The known method has the disadvantage that it requires
a very high outlay and that that region of the housing

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and of the throttle valve which is located upstream of
the throttle valve in the direction of flow is covered
by sealing compound. Only a small part of the sealing
compound therefore arrives at the gap to be sealed off.
The problem on which the invention is based is to
develop a method of the type initially mentioned, in
such a way that the throttle valve can be sealed off
with respect to the housing particularly cost-
effectively. Furthermore, a throttle valve assembly
sealed off cost-effectively by means of this method is
to be provided.
The first-mentioned problem is solved, according to the
invention, in that the sealing compound is applied in
drop form into regions of the throttle valve and of the
housing which abut one another, in a quantity
sufficient for conduction by means of the capillary
forces.
By virtue of this arrangement, spray mists of the
sealing compound in the housing and on the throttle
valve are avoided. The sealing compound can be applied
exactly to the intended point, for example, by means of
a cannula. The entire sealing compound therefore
reaches the point to be sealed. Furthermore, the
sealing compound can be metered particularly accurately
by means of a cannula. Complicated atomization of the
sealing compound is not necessary in the method
according to the invention.
To assist the capillary forces, as in the known method,
an intended pressure difference could be set on both
sides of the throttle valve. In this case, however, the
throttle valve assembly must be mounted on the internal
combustion engine or a suction-extraction device in
order to generate the vacuum. Moreover, since the

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throttle valve is slightly distorted by the vacuum,
during the injection of the sealing compound into the
housing the vacuum must be set very accurately to the
vacuum occurring when the internal combustion engine is
idling. The method according to the invention requires
a particularly low outlay when the two sides of the
throttle valve are brought into pressure equilibrium
before the sealing compound is applied.
In what are known as E-gas systems, in which the
throttle valve is pivoted by means of an electrically
operable servomotor, a blockage of the throttle valve
after the curing of the sealing compound can be avoided
in a simple way when, after a curing of the sealing
compound, current is applied to a servomotor driving
the throttle valve and consequently the throttle valve
is pivoted.
The second-mentioned problem, to be precise the
provision of a throttle valve assembly sealed off cost-
effectively by means of the method, is solved,
according to the invention, in that the sealing
compound is disposed solely in a gap between the
throttle valve and the housing.
By virtue of this arrangement, only a particularly
small quantity of sealing agent is necessary, since the
throttle valve itself and part of the housing are not
covered by sealing agent. The throttle valve assembly
according to the invention thereby has a particularly
cost-effective design. A further advantage of the
invention is that a spherical segment is not
contaminated by the sealing compound.
The invention permits numerous embodiments. To make its
basic principle even clearer, two of these are

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illustrated in the drawing and are described below. In
the drawing:
fig. 1 shows a sectional illustration through a
throttle valve assembly in the region of a
throttle valve shaft,
fig. 2 shows a sectional illustration through the
throttle valve assembly from figure 1 along the
line II-II,
fig. 3 shows a sectional illustration through a
further embodiment of the throttle valve
assembly in the region of the throttle valve,
fig. 4 shows a sectional illustration through the
throttle valve assembly from figure 3 along the
line IV-IV.
Parts corresponding to one another are given the same
reference symbols in all the figures.
Figure 1 shows a throttle valve assembly 1 with a
tubular housing 2 and with a throttle valve 3 pivotably
mounted in the latter. The throttle valve 3 is fastened
on a throttle valve shaft 4 mounted in the tubular
housing 2. The tubular housing 2 has mountings 5, 6 for
the throttle valve shaft 4. The throttle valve assembly
1 illustrated is in the closing position, in which the
throttle valve 3 closes the tubular housing 2.
Figure 2 shows the throttle valve assembly 1 from
figure 1 in a sectional illustration along the line
II-II. In the lower half of the throttle valve assembly
1, it is illustrated that the throttle valve 3 is
sealed off with respect to the wall of the tubular
housing 2 by means of a sealing compound 7. The sealing

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compound 7 is cured. In the event of a pivoting of the
throttle valve 3, the sealing compound 7 remains on the
tubular housing 2. The upper half shows the throttle
valve assembly 1 during the application of liquid
5 sealing compound 8 into the regions of the tubular
housing 2 and of the throttle valve 3 which are
adjacent to one another. The sealing compound 8 is
applied in drop form by means of a cannula 9 and is
transported into the gap between the tubular housing 2
and the throttle valve 3 by means of the capillary
forces. The sealing compound 8 can subsequently cure.
The sealing compound 7, 8 may be, for example, a slip
lacquer which cures after the volatilization of the
solvent and contains, for example, molybdenum sulfide
or polytetrafluoroethylene. The slip lacquer may
selectively cure or be baked at room temperature.
Figure 3 shows a further embodiment of the throttle
valve assembly 1. This differs from that from figure 1
in that the throttle valve 3 is adjustable by an
electrically drivable servomotor 10.
As figure 4 shows in a sectional illustration through
the throttle valve assembly 1 from figure 3 along the
line IV-IV during the application of the sealing
compound 7, 8, the housing 3 has, near the throttle
valve 3, two spherical segments 11 located opposite one
another. These spherical segments 11 allow a
particularly good meterability of the air throughput
through the housing 2 in the case of small opening
angles of the throttle valve 3. The introduction of the
sealing compound 7, 8 takes place as in the throttle
valve assembly 1 described in figures 1 and 2. Here,
however, after the curing of the sealing compound 7, 8,
current can be applied to the servomotor 10 and the
throttle valve 3 be pivoted.

Representative Drawing