TUBELESS PNEUMATIC VEHICLE TIRE

PNEU DE VEHICULE SANS CHAMBRE

English Abstract

Tubeless pneumatic vehicle tire comprising a tread (1) that has a plurality of spikes (5), further comprising sidewalls (3), bead regions (2) and an airtight inner ply (4) that forms the inner face (4a) facing the interior of the pneumatic vehicle tire, a noise damping ply (6, 6', 6") being circumferentially mounted in the area of the inner face (4a) lying opposite the tread (1). The noise damping ply (6) has a maximum degree of absorption in the range of 300 to 500 Hz.

French Abstract

Pneu de véhicule sans chambre, comprenant une bande de roulement (1) pourvue d'une pluralité de crampons (5), des flancs (3) et des zones de talon (2) ainsi qu'une couche intérieure (4) conçue de manière étanche à l'air et formant la face intérieure (4a) orientée vers le compartiment intérieur du pneu de véhicule. Une couche d'absorption acoustique (6, 6,', 6'') est disposée dans la zone, opposée à la bande de roulement (1), de la face intérieure (4a), de manière périphérique et annulaire. La couche d'absorption acoustique (6) présente son taux d'absorption maximal dans la plage de 300 Hz à 500 Hz.

Claims

6
.. Patent claims
1. A tubeless pneumatic vehicle tire having a tread provided with a
multiplicity of
spikes, sidewalls and bead regions and also having an airtight inner layer
which
forms the inner side facing the interior of the pneumatic vehicle tire,
wherein a
noise damping layer is applied in an annularly encircling manner to that
region of
the inner side that is located opposite the tread, characterized in that the
noise
damping layer exhibits its maximum degree of absorption in the range from 300
Hz
to 500 Hz.
2. The pneumatic vehicle tire as claimed in claim 1, characterized in that the
noise
damping layer consists of a thermoplastic or elastomeric foam.
3. The pneumatic vehicle tire as claimed in claim 1 or 2, characterized in
that the
noise damping layer consists of polyurethane foam.
4. The pneumatic vehicle tire as claimed in any one of claims 1 to 3,
characterized in
that the noise damping layer has a constant width of 30% to 100% of the width
of
the tire contact patch.
5. The pneumatic vehicle tire as claimed in claim 4, characterized in that the
constant
with of the noise damping layer is of at least 80% of the width of the tire
contact
patch.
6. The pneumatic vehicle tire as claimed in any one of claims 1 to 5,
characterized in
that the noise damping layer has a constant thickness of 5% to 20% of the
constant
width.
7. The pneumatic vehicle tire as claimed in any one of claims 1 to 6,
characterized in
that that side of the noise damping layer that faces the interior of the tire
is provided
with a multiplicity of elevations.
Date Recue/Date Received 2023-03-07

7
8. The pneumatic vehicle tire as claimed in any one of claims 1 to 6,
characterized in
that that side of the noise damping layer that faces the interior of the tire
is provided
with a multiplicity of recesses.
Date Recue/Date Received 2023-03-07

Description

CA 02994992 2018-02-07
=
W02017/032476 1
PCT/EP2016/064156
Description
Tubeless pneumatic vehicle tire
The invention relates to a tubeless pneumatic vehicle tire having a tread
provided with a
multiplicity of spikes, sidewalls and bead regions and also having an airtight
inner layer
which forms the inner side facing the interior of the pneumatic vehicle tire,
wherein a noise
damping layer is applied in an annularly encircling manner to that region of
the inner side
that is located opposite the tread.
Pneumatic vehicle tires provided with spikes represent a different noise
source compared
with unspiked winter tires. A specific rolling noise is generated in
particular by the hard-
metal pins of the spikes striking the ground surface while the tire is
rolling. By optimizing
the positions of the spikes in the tread, the objectively measured and
subjectively perceived
rolling noise of spiked tires can be improved, but has not yet achieved the
noise level of a
spike-free winter tire. The number of spikes used in the tread has been
increased
considerably in recent years from around 130 per tread to over 200 per tread,
depending on
the tire size. As a result, the conflict of aims between an optimum
arrangement of the spikes
in the tread in order to achieve good force transmission on an icy ground
surface and the
objectively measurable and the subjectively perceived rolling noise has been
intensified.
In the patent literature, in particular, there are a number of proposed
solutions in which, in
order to reduce the outwardly emitted and audible noise and the noise level in
the interior of
the vehicle, foam is introduced into the interior of the tire. Thus, for
example, DE 198 06
135 Al discloses a method for producing a pneumatic vehicle tire having a
sound-
absorbing foam layer adhering to the inner layer, wherein the tire is already
covered with
the foam layer before vulcanization and the foam layer is chemically and/or
mechanically
bonded to the inner layer during vulcanization. In the case of the tubeless
pneumatic vehicle
tire known from DE 197 50 229 Al, a layer of closed-cell foam, which is bonded
to the tire
by adhesion, is located on the tire inner side, adhering to the latter.

CA 02994992 2018-02-07
VV02017/032476 2
PCT/EP2016/064156
The invention is based on the object, in the case of a pneumatic vehicle tire
of the type
mentioned at the beginning, of reducing the objectively measurable and also
the
subjectively perceptible rolling noise generated by spikes in the tread during
rolling over
the ground surface.
The object set is achieved according to the invention in that the noise
damping layer
exhibits its maximum degree of absorption in the range from 300 Hz to 500 Hz.
Therefore, according to the invention, a noise damping layer is used in the
interior of the
tire, said noise damping layer being coordinated in a targeted manner with the
excitation
spectrum generated by the spikes in the tread while the tire is rolling on the
ground surface.
In the scope of extensive tests, it was found that, for example at a vehicle
speed of 80 km/h,
dominant frequencies of the noise induced by the spikes are in the range
around 400 Hz.
The vibrations excited by the spikes are damped and prevented from propagating
into the
interior of the vehicle. By way of the noise damping layer according to the
invention, the
objectively measurable and the subjectively perceptible rolling noise of
spiked tires can be
noticeably reduced.
In a preferred embodiment of the invention, the noise damping layer consists
of a
thermoplastic or elastomeric foam, preferably of polyurethane foam. Damping
layers made
of such foams can be realized particularly well in accordance with the desired
maximum
degree of absorption in the range from 300 Hz to 500 Hz.
Depending on the tire type and the number and arrangement of spikes,
particular
embodiments of the noise damping layer are particularly advantageous in order
to achieve
particularly good damping. According to one of these preferred embodiments,
the noise
damping layer has a constant width of 30% to 100% of the width of the tire
contact patch,
in particular of at least 80% of the width of the tire contact patch. Also
particularly
preferred is an embodiment in which the noise damping layer has a constant
thickness of
5% to 20% of its width.

CA 02994992 2018-02-07
VV02017/032476 3
PCT/EP2016/064156
To further improve sound damping, that side of the noise damping layer that
faces the
interior of the tire can be provided with a multiplicity of elevations or with
a multiplicity of
recesses.
Further features, advantages and details of the invention will now be
described in more
detail on the basis of the drawing. In the drawing:
Figure 1 shows a cross section through a tire in one embodiment of the
invention,
Figure 2 and figure 3 show cross sections through portions of variant
embodiments of
damping layers.
Figure 1 schematically shows the cross section of a tubeless radial pneumatic
vehicle tire
intended in particular for passenger vehicles, vans or light trucks, which is
suitable and
intended for use in wintry driving conditions and has a profiled tread 1, bead
region 2 and
sidewalls 3. The pneumatic vehicle tire also has an airtight inner layer 4
which covers and
forms the inner side 4a of the tire. Figure 1 also indicates that spikes 5 are
anchored in the
tread I. The spikes 5 have, in a known manner, a spike pin and a spike body,
wherein the
spike pin usually consists of a hard metal and the spike body is produced for
example from
aluminum.
In that region of the inner side 4a that is opposite the tread 1, a noise
damping layer 6 is
applied, in particular adhesively bonded, in an annular encircling manner to
the inner side
4a. The design and material of the damping layer 6 are such that the degree of
absorption of
the damping layer 6 is greatest in the frequency range from 300 Hz to 500 Hz.
In this way,
the sound absorption of the damping layer 6 is coordinated in a targeted
manner with the
excitation spectrum generated by the spikes in the tread during rolling. On
account of their
construction, spiked tires generate vibrations in the air column in the tire
while the tire is
rolling, said vibrations being caused by the spikes striking the road surface.
At a vehicle
speed of 80 km/h, a dominant frequency of the noise induced by the spikes lies
for example
in the range around 400 Hz.

CA 02994992 2018-02-07
VV02017/032476 4
PCT/EP2016/064156
In a preferred embodiment of the invention, the noise damping layer 6 consists
of a
thermoplastic or elastomeric foam, preferably of polyurethane foam. The
damping layer 6
has a constant width b which is between 30% and 100% of the width of the tire
contact
patch, in particular at least 80% of the tire contact patch. The in particular
constant
thickness d of the damping layer 6 is between 5% and 20% of the width and
therefore for
example between 20 mm and 50 mm, depending on the tire size.
Figure 2 and figure 3 show further variant embodiments of noise damping layers
6', 6"
made of foam. In the embodiment shown in figure 2, that side of the damping
layer 6' that
faces the interior of the pneumatic vehicle tire is provided with a
multiplicity of elevations
7 for example in the form of pyramids. The elevations 7 can also be configured
in the form
of cones, truncated cones and the like. In the embodiment shown in figure 3,
that side of the
damping layer 6" that faces the interior of the tire is provided with a
multiplicity of recesses
8, which can be configured as desired.

CA 02994992 2018-02-07
W02017/032476 5
PCT/EP2016/064156
List of reference numerals
1 ............. Tread
........ 2 Bead region
3 ............. Sidewall
4 ............. Inner layer
4a ............ Inner side
5 ............. Spikes
........ 6, 6', 6" Damping layer
7 ............. Elevation
8 ............. Recess
.............. Width
.............. Thickness

Representative Drawing