Pressure device for a foam strip in a tire and method for pressing it down

Abstract

The present invention relates to a device for pressing a foam strip onto the inner tread of a tire, characterized in that the device comprises a pressing unit comprising a carrier device and a pressing element, wherein the carrier device is a carrier device for the pressing element and wherein the pressing element is an inflatable element that extends over the entire outer circumference of the carrier device and is expandable at least in the radial direction. Furthermore, a method for pressing a foam strip onto the inner tread of a tire is described.

Description

[0001] The present invention relates to a pressing device for a foam strip in a tire and a method for pressing a foam strip in a tire.

[0002] When driving, vehicle tires generate rolling noise. To minimize this noise, a foam strip is inserted into the tire cavity, located between the rim and the tire. Without the foam strip, the tire cavity acts as a resonator, amplifying air vibrations that are transmitted to the vehicle structure. The foam strip is glued into the tire and reduces the resonance of the tire cavity.

[0003] One method for inserting a foam strip is known, for example, from CN113696528A. A foam strip cassette containing the foam strip is inserted into the tire. The foam strip is unrolled from the cassette and applied to the inside of the tire using adhesive. A disadvantage of this method of inserting the foam strip into the tire is that the connection between the foam strip and the inside of the tire is only made by a roller on the cassette. The pressure on the foam strip, and thus the connection between the foam strip and the inside of the tire, is therefore minimal.

[0004] Furthermore, a device for inserting a foam ring into a tire is known from EP2727713B1, in which the foam ring is supported by radially outwardly movable segments and fingers arranged between the segments. By moving the segments radially outward, the foam ring is pressed against the inside of the tire. A disadvantage of this device is its complex structure.

[0005] The object of the present invention is therefore to provide a solution by means of which a foam element applied to the inner tread of a tire can be pressed onto the inner tread of the tire in a simple and reliable manner.

[0006] The invention is based on the finding that this object can be achieved by using a pressing element which is an inflatable element.

[0007] According to a first aspect, the invention therefore relates to a device for pressing a foam strip onto the inner tread of a tire. The device is characterized in that the device comprises a pressing unit comprising a support device and a pressing element, wherein the support device is a support device for the pressing element, and wherein the pressing element is an inflatable element that extends over at least part of the outer circumference of the support device and is expandable at least in the radial direction.

[0008] A foam strip is a flexible strip of foam material. The ends of the strip may be attached to each other, forming a foam ring.

[0009] A tire is a motor vehicle tire. The inner tread of the tire is the radially inward-facing part of the tire's interior. Thus, the inner tread is opposite the part of the outer side of the tire where the tread is usually located.

[0010] The device for pressing the foam strip is also referred to below as the pressing device or pressing device. Pressing refers to the pressing of a foam strip onto the inner tread, whereby the foam strip was previously applied to the inner tread and thus at least temporarily fixed. In this case, the foam strip is applied and thus fixed using adhesive.

[0011] According to the invention, the device comprises a pressing unit. The pressing unit is the assembly unit by means of which pressure or force can be applied to the foam strip inserted into the tire.

[0012] The pressing unit comprises a support device and a pressing element. The support device represents a support device for the pressing element. The support device is the part of the pressing unit to which the pressing element is attached and via which inflation fluid can preferably be introduced into the pressing element. The support device preferably has a central axis from which at least one component, which can also be referred to as a boundary plate, extends preferably perpendicular to the central axis. The boundary plate has a flat shape and is made of a rigid material. The shape of the boundary plate can be round or square. In particular, the boundary plate can, for example, have a square or polygonal shape, a circular or oval shape. The boundary plate is preferably a circular component.The limiting plate of the support device extends radially from the center axis of the support device. In the simplest case, the support device is formed by two limiting plates and, if provided, a connecting element between them.

[0013] Unless otherwise stated, terms such as radial and axial correspond to the radial or axial direction of the support device. Radial refers to a direction running from the center axis of the support device, in particular a boundary plate, along the radius. Axial refers to a direction parallel to the center axis of the support device, in particular a boundary plate. When the support device is inserted into a tire, the center axis of the support device preferably lies in the center axis of the tire.

[0014] The pressing element is the element that is at least partially in contact with the foam strip when expanded.

[0015] The expanded state refers to the state of the compression element in which it is completely filled with inflation fluid, i.e., inflated. The pressure in the compression element is preferably adjusted so that the compression element expands to its maximum shape and does not change this shape even when subjected to external force.

[0016] The pressing element extends over at least part of the outer circumference of the carrier device. The outer circumference of the carrier device is the outer edge of the carrier device which is at the greatest distance from a central axis of the carrier device. If the carrier device consists of boundary plates, the pressing element extends at least part of the outer circumference of each boundary plate. The pressing element thus covers at least part of the outer circumference of the carrier device. If there is a distance in the circumferential direction between the parts of the pressing element, each part of the pressing element is preferably designed such that, upon inflation and expansion, it enlarges in the circumferential direction to such an extent that the parts of the pressing element bear against one another in the circumferential direction.

[0017] The pressing element is an inflatable element. An inflatable element is one that has an interior space into which fluid can be introduced, thereby changing the shape and / or size of the element. The pressing element is therefore preferably made of a flexible material that is impermeable to fluid. In particular, the pressing element can consist of a flexible, air-impermeable material. According to one embodiment, the material of the pressing element can be an expandable material. The expandability can be adjusted on the one hand by the material of the pressing element and on the other hand by the thickness of the material. For example, the pressing element can be made of a plastic film.

[0018] The pressing element is expandable at least in the radial direction. The expansion is achieved in particular by filling the pressing element with an inflation fluid. In particular, the pressing element is expandable in the direction from the center axis of the support device in the radial direction over the outer circumference of the support device. For this purpose, the pressing element preferably has a shape that allows expansion in the radial direction over the outer circumference of the support device. A pressing element is referred to as expandable if the dimension of the pressing element is increased at least in some regions in the radial direction from an uninflated or evacuated state to an inflated or expanded state.

[0019] In addition to expansion in the radial direction, the pressing element can also be expandable in the axial direction and / or in the circumferential direction. Particularly in the case of a multi-part pressing element in which the parts of the pressing element are distributed over the circumference of the support device, the parts of the pressing element are preferably also expandable in the circumferential direction in addition to the radial direction.

[0020] The support device can be designed as a single piece with the pressing element. In this embodiment, the support device can be made of plastic, for example, in particular comprise plastic plates. The pressing element, for example made of plastic film, can be welded to this support device. Alternatively, the pressing element is detachably connected to the support device. In this embodiment, the support device can be made of metal, for example, and the pressing element, for example made of a plastic film, can be connected to the support device, for example, via pins or screws.

[0021] The pressing unit is preferably designed such that the outer circumference of the support device is smaller than the rim opening of the tire. In the inflated state of the pressing element, the outer circumference of the pressing element is preferably larger than the inner diameter of the foam strip applied to the inner tread, and more preferably larger than or equal to the inner diameter of the inner tread of the tire.

[0022] By providing the pressing device for the foam strip with a pressing element which extends over at least part of the outer circumference of the carrier device, represents an inflatable element and is expandable at least in the radial direction, a number of advantages can be achieved.

[0023] In particular, a force can be applied to the foam strip in a simple manner by introducing fluid into the pressing element. The control of individual segments, as described in the prior art, is not necessary in this case. The pressing device can be used to press the foam strip introduced into the tire against the inner tread of the tire. This can improve the bond created by the adhesive applied to the foam strip or the inner tread. On the one hand, this can increase the distribution of the adhesive, which is usually applied in beads, on the inner tread. On the other hand, the penetration of the adhesive into the foam strip can be achieved, thereby further increasing the adhesive surface.

[0024] According to a preferred embodiment, the pressing element extends over the entire outer circumference of the carrier device.

[0025] By radially expanding the pressing element provided over the entire circumference of the support device, the pressing element can be brought into contact with the foam strip simultaneously over the entire inner circumference. Furthermore, with a pressing element with a round cross-section, further inflation of the pressing element can increase the contact area between the foam strip and the pressing element in the axial direction. Finally, by further increasing the pressure within the pressing element, the force on the foam strip can be increased. Thus, with the pressing device according to the invention, the foam strip can be pressed evenly over the circumference with a uniformly increasing force. In comparison to the prior art, in which only individual segments are used for pressing, no shear stress is exerted on the surface of the foam strip with the pressing device according to the invention.In addition, uniform pressure can be maintained across the entire circumference for a longer period of time, further improving the bond between the foam strip and the tire's inner tread. The foam strip is typically applied to the tire as a flat strip, meaning it has no curvature across the width of the inner tread before insertion. After application, which in the prior art is only carried out selectively using a pressure roller or by pressing segmentally, the foam strip generally tends to return to its original state due to residual stress, meaning it has no curvature across the width. This causes the applied foam strip to detach from the inner tread.

[0026] The improved bond between the tire and the foam strip achieved according to the invention counteracts the inherent stress and thus the detachment of the foam strip. In particular, the adhesive surface between the inner tread and the foam strip can be increased.

[0027] The pressing element can have a round shape in plan view when inflated. The pressing element can, in particular, have an oval outer circumference. In particular, the outer circumference can be a circle or an ellipse. In a support device in which the boundary plates each have a circular shape and the pressing element extends over the entire circumference of the support device, the pressing element represents a ring when inflated.

[0028] According to one embodiment, the pressing element, when inflated, represents a circular ring. A circular ring is referred to as a torus. In this embodiment, the pressing element therefore has a shape created by a vertical circle rotating around the central axis of the support device. The advantage of a ring is that the pressure present in the pressing element can be distributed evenly across the outer circumference of the pressing element.

[0029] Alternatively, the shape of the pressing element in the inflated state can also deviate from that of a circular ring. For example, the shape rotated around the central axis can be an ellipse instead of a circle. The shape of the pressing element in the inflated state preferably corresponds to the inner contour of the tire. Thus, the outer circumference of the pressing element in the inflated state can be formed by a straight or convexly curved outer wall that lies parallel to the central axis of the support device. From this wall, the height of the pressing element in the inflated state can decrease towards the support device. The height here refers to the dimension of the pressing element in the inflated state that lies parallel to the central axis of the support device. In the inflated state of the pressing element in the tire, the height of the pressing element is therefore in the width direction of the tire.

[0030] The pressing element preferably has at least one supply opening for supplying inflation fluid. Air can be used as the inflation fluid, and this will also be referred to as such below. By providing a supply opening, the pressing element can be inflated during the process of pressing the foam strip, and the pressure in the pressing element can be adjusted. According to a preferred embodiment, the pressing element has at least one supply opening for inflation fluid in the radially inward-facing inner side. Since the radially outward-facing outer side of the pressing element represents the contact area via which the pressing element comes into contact with the foam strip, the supply opening on the inner side is outside the contact area and therefore does not influence the contact. In the case of an annular pressing element, the at least one supply opening is provided on the inner circumference of the ring.

[0031] According to one embodiment, the feed opening extends over the entire circumference of the radially inward-facing inner side of the pressing element. In this embodiment, the pressing element therefore has only one feed opening. In this embodiment, the feed opening thus forms an annular slot or gap. An advantage of the embodiment in which the feed opening extends over the entire circumference of the inner side of the pressing element, in particular a ring, is that the inflation fluid can be distributed evenly in the pressing element and pressure changes in the pressing element can also be quickly implemented. Thus, the force exerted by the pressing element on the foam strip can also be changed evenly and quickly.

[0032] According to one embodiment, the carrier device comprises a first and a second limiting plate. The first limiting plate is also referred to below as the upper limiting plate and the second limiting plate as the lower limiting plate. The limiting plates are preferably each circular in shape. The limiting plates extend in the radial direction from the central axis of the carrier device. The limiting plates are preferably arranged parallel to one another at a distance from one another. By providing the limiting plates, the expansion of the pressing element can be limited in two directions. In the inflated state, the pressing element extends over the outer circumference of the limiting plates at least in the radial direction outwards. In addition, the pressing element can also extend in the axial direction over the limiting plates in the axial direction, i.e. upwards and downwards.

[0033] According to one embodiment, the first and second limiting plates are movably connected to one another via a connecting element, by which the distance between the limiting plates can be adjusted. The connecting element can be, for example, a threaded rod or a threaded tube. The limiting plates can be moved toward or away from one another on or via this connecting element. Depending on the tire type, the distance between the limiting plates can thus be adjusted.

[0034] According to one embodiment, the pressing element is attached to the periphery of the first and second limiting plates. The attachment can be detachable or non-detachable. In the embodiment in which the pressing element is attached to the periphery of the limiting plates, the gap between the limiting plates forms the annular feed opening for the pressing element.

[0035] According to one embodiment, the pressing unit comprises a fluid supply line for supplying the inflation fluid into the interior of the pressing element. A fluid guide channel is formed in the fluid supply line. In the embodiment in which the support device comprises an upper and lower limiting plate, the fluid guide channel leads to the distance between these limiting plates. The fluid supply line can be connected to a passage opening in the lower or upper limiting plate of the support device.

[0036] According to one embodiment, the fluid supply line comprises a first supply channel and a second supply channel, which are displaceable relative to one another. In this embodiment, the fluid guide channel is formed by these two supply channels and represents a telescopic fluid guide channel. At least one fluid outlet opening is preferably provided in the first supply channel. The first supply channel is also referred to as the upper supply channel and the second supply channel as the lower supply channel. The embodiment with two telescopic supply channels, in which a fluid outlet opening is provided in one supply channel, makes it easy to ensure reliable supply of the fluid to the pressing element even when the distance between the first and second limiting plates changes.

[0037] The upper supply channel is preferably attached to the underside of the upper boundary plate. The lower supply channel is preferably attached to the underside of the lower boundary plate. In this embodiment, the lower boundary plate preferably has a passage opening for the upper supply channel.

[0038] According to one embodiment, the pressing device has a base part for supporting the tire. The base part can be a table. The pressing unit is preferably provided on the base part. The pressing unit can be partially integrated into the base part or attached to it. In particular, the support device, comprising a first and a second limiting plate, can be attached to the base part so that it can be displaced upwards.

[0039] According to one embodiment, the pressing device comprises centering elements, which are preferably arranged in the surface of the base part. The centering elements can be, for example, ball rollers. The centering elements serve to align the center axis of a tire placed on the base part with the center axis of the support device, i.e., to center the tire relative to the center axis of the support device. This centering occurs automatically when the pressing element is inflated.

[0040] According to a further aspect, the present invention relates to a method for pressing a foam strip onto the inner tread of a tire. The method is characterized in that it is carried out using a pressing device according to the invention.

[0041] Advantages and features described with regard to the device apply - where applicable - correspondingly to the method according to the invention and vice versa and are described only once if necessary.

[0042] According to one embodiment, the method comprises the step of inflating the pressing element after it has been introduced into the interior of the tire.

[0043] According to one embodiment, the device comprises a first limiting plate and a second limiting plate and the method comprises the step of adjusting the distance between the first and second limiting plates.

[0044] The invention is described in more detail below with reference to the accompanying figures. They show: Fig. 1: a schematic, perspective view of an embodiment of the pressing device according to the invention; Fig. 2: a schematic, perspective view of an embodiment of the pressing unit with the pressing element in the evacuated state; Fig. 3: a schematic perspective view of the pressing unit according to Fig. 2 with the pressing element in the inflated state; Fig. 4: a schematic simplified sectional view of the press unit according to Fig. 2 with the pressing element in the inflated state; Fig. 4a: a schematic simplified sectional view of another embodiment of a pressing unit with the pressing element in the inflated state; Fig. 5: a schematic, perspective partial sectional view of the pressing unit according to Fig. 2; Fig. 6: a schematic perspective view of the pressing unit according to Fig. 2; Fig. 7: a schematic sectional view of the pressing unit according to Fig. 2; Fig. 8: a schematic sectional view of a tire part without pressing treatment.

[0045] In Fig. Figure 1 shows an embodiment of a pressing device 1 according to the present invention. In the illustrated embodiment, the pressing device 1 comprises a base part 10 and a pressing unit 11.

[0046] In Fig. 2 is a schematic bottom view of the pressing unit 11 of the Fig. 1, where the view in the Fig. 2 is a bottom view of the pressing unit 11. The pressing unit 11 comprises a lower limiting plate 112 and an upper limiting plate (111 in Fig. 1) and a pressing element 110. The limiting plates 111, 112 form the support device of the pressing unit 11 and the pressing element 110 represents an inflatable element.

[0047] The pressing element 110 is in Fig. 2 in an evacuated state. In this state, there is no fluid in the interior of the pressing element 110. In Fig. Figure 3 shows the pressing element 110 in the inflated state. As can be seen from this illustration, the pressing element 110 has a circular ring shape when inflated.

[0048] In the embodiment shown, the pressing unit 11 has a first limiting plate 111 and a second limiting plate 112. The first limiting plate 111 is also referred to below as the upper limiting plate and the second limiting plate 112 as the lower limiting plate. The pressing element 110 is fastened to the outer circumference of the limiting plates 111, 112. For this purpose, connecting pins are provided along the circumference on the upper side of the upper limiting plate 111 and on the underside of the lower limiting plate 112. One end of the material of the pressing element 110 can be fastened to the upper limiting plate 111 and the other end of the material of the pressing element 110 can be fastened to the lower limiting plate 112. In the embodiment shown, a perforated ring is provided in each case, in which holes are provided corresponding to the position of the connecting pins.The respective end of the pressing element 110 can be clamped between the limiting plate 111 or 112 and the corresponding perforated ring. The pressing element 110 can also have openings provided corresponding to the positions of the connecting pins. In this embodiment, the ends of the pressing element 110 are connected to the respective limiting plate 111, 112 via the connecting pins and clamped between the respective limiting plate 111, 112 and the corresponding perforated ring. For this purpose, the perforated rings can be connected to the connecting pins of the limiting plates 111, 112 via screws or nuts. In addition, one or more seals (not shown) can be provided between the limiting plate 111, 112 and the pressing element 110.

[0049] The upper limit plate 111 and lower limit plate 112 each represent a circular plate. The diameter of the lower limit plate 112 is smaller than the diameter of the rim opening of the tire 2, i.e., the inner diameter of the tire. The limit plates 111, 112 are arranged parallel to each other.

[0050] A portion of a fluid supply line 12 extends from the lower boundary plate 112 of the pressing unit 11. This fluid supply line 12 comprises a line connection 124, via which the fluid supply line 12 can be supplied with fluid, in particular air. A fluid guide channel 120 is formed in the fluid supply line 12, via which air can be guided to and in particular into the pressing element 110.

[0051] The pressing element 110 can be inserted into the interior of the tire with the limiting plates 111, 112. The limiting plates 111, 112 extend parallel to the rim openings of the tire 2 inside the tire 2. For insertion into the tire, the pressing element 110 is evacuated, i.e., the air is removed from the pressing element 110. This state of the pressing element 110 is shown in Fig. 2 shown schematically.

[0052] After the pressing element 110 with the limiting plates 111, 112, i.e., the support device, has been inserted into the tire 2, fluid, in particular air, can be introduced into the pressing element 110 via the fluid supply line 12. This inflates the pressing element 110 and expands in the radial direction. The pressing element 110 thus comes into contact with the foam strip 22, which is adhered to the inner tread of the tire 2. The outer diameter of the pressing element 110 in the inflated state is preferably larger than the inner diameter of the foam strip 22 inserted into the tire 2 and can be larger than or equal to the inner diameter of the inner tread 21 of the tire 2.After the first contact of the pressing element 110 with the foam strip 22, with a further increase in the pressure in the pressing element 110 and thus further expansion of the pressing element 110 in the radial direction, the force increases uniformly over the surface of the inner side of the foam strip 22. As a result, no shear stress acts on this surface of the foam strip 22.

[0053] Before filling the pressing element 110, the position of the limiting plates 111, 112 relative to each other can be adjusted. In particular, the distance between the limiting plates 111, 112 is changed. The distance can be adjusted, for example, to the distance between the rim openings of the tire 2, and preferably to a smaller distance.

[0054] With reference to the Fig. 5 to 7, an embodiment of a structure that enables adjustment of the distance between the limiting plates 111, 112 is described.

[0055] As can be seen from Fig. 5, the upper limiting plate 111 is connected to the lower limiting plate 112 via a connecting element 113. The connecting element 113 can in particular be a threaded rod or a threaded tube. In the embodiment shown, the upper limiting plate 111 is mounted on the connecting element 113 via a bearing, which is fastened to the connecting element 113 in a rotationally fixed manner. The upper limiting plate 111 is rotatably held on the connecting element 113 via the bearing. At the upper end of the connecting element 113, an adjusting element 13 is also provided, which is connected to the connecting element 113 in a rotationally fixed manner. The adjusting element 13 is a crank in the embodiment shown. In addition, the connecting element 113 is rotatably connected to the lower limiting plate 112. In the embodiment shown, a connecting web 114 is provided on the lower limiting plate 112 for this purpose.A through-hole is provided in the connecting web 114, which preferably has an internal thread. By rotating the adjusting element 13, the connecting element 113 is screwed into or out of the connecting web 114. This moves the upper limiting plate 111 toward or away from the lower limiting plate 112, thus adjusting the distance between the limiting plates 111, 112.

[0056] In the Fig. 4 and Fig. 4a shows schematic sectional views of embodiments of the pressing unit with different pressing elements 110. In the Fig. 4, the pressing element 110 has the shape of a circular ring. In the Fig. 4a, the shape of the pressing element 110 corresponds to the inner contour of the tire 2.

[0057] In the Fig. In the embodiment shown in Figures 5 to 7, the fluid guide channel 120 formed in the fluid supply line 12 is also two-part. In particular, the fluid guide channel 120 consists of two channel parts. In particular, a lower supply channel 122 and an upper supply channel 121 are provided. The supply channels 121, 122 each have a tubular shape and are displaceable relative to one another in the axial direction. Thus, the fluid guide channel 120 is telescopic. In the embodiment shown, the outer diameter of the upper supply channel 121 is smaller than the inner diameter of the lower supply channel 122. The upper supply channel 121 is attached to the underside of the upper limiting plate 111. The lower supply channel 122 is attached to the underside of the lower limiting plate 112. In the embodiment shown, two fluid outlet openings 123 are provided in the lateral surface of the upper supply channel 121.The fluid outlet openings 123 extend in the axial direction and are arranged diametrically opposite one another. The fluid outlet openings 123 can also be referred to as a slot or gap. The fluid outlet openings 123 can extend over the entire length of the upper supply channel 121 or can end at a distance from at least the upper end of the supply channel 121.

[0058] In the lower limiting plate 112, in the Fig. In the embodiment shown in Figures 5 to 8, a passage opening is provided through which the upper supply channel 121 can penetrate into the lower supply channel 122. The connecting web 114 extends diametrically across this passage opening. The width of the connecting web 114 corresponds to the width of the fluid outlet opening 123.

[0059] A line connection 124 is provided at the lower end of the lower supply channel 122. Via this line connection 124, a fluid can be introduced from a fluid source (not shown) into the fluid guide channel 120 and in particular into the lower supply channel 122. As can be seen from the Fig. 5 and Fig. 6, the fluid flows via the lower supply channel 122 to the upper supply channel 121 and leaves it via the fluid outlet openings 123. From the fluid outlet opening 123, the fluid flows into the interior of the pressing element 110. The distance between the first and second limiting plates 111, 112 at the edge forms the supply opening to the pressing element 110.

[0060] With reference to Fig. 1, the implementation of an embodiment of the method for pressing a foam strip 22 in a tire 2 is described below.

[0061] In Fig. 1 shows an embodiment of the pressing device 1. The base part 10 has a surface on which the tire 2 can be placed. In the embodiment shown, the base part 10 represents a table. Centering elements 100 are mounted in the surface of the base part 10. These can in particular be rollers, balls, or ball rollers. In addition, the pressing device 1 comprises a pressing unit 11, of which Fig. 1 only the limiting plates 111, 112, the adjusting element 13 for the upper limiting plate 111 and a part of the fluid supply line 12 as well as an adjusting element 14 for the lower limiting plate 112 are visible. The pressing element is in the Fig. 1 not shown. The adjustment element 14 can be used to adjust the relative position of the lower limiting plate 112 to the surface of the base part 10 on which the tire is placed. Furthermore, Fig. 1 shows a linear guide 15, which serves to adjust the height of the lower limit plate 112. In the embodiment shown, an adjustment aid 16 is also provided, which comprises a foldable arm, which can be engaged when the upper limit plate 111 reaches a certain height above the base part 10, or the height of the upper limit plate 111 can be limited.

[0062] In the embodiment shown, the pressing device 1 further comprises an operating unit 17, via which in particular the fluid supply to the pressing element 110 can be adjusted.

[0063] Although for the adjustment of the heights of the upper and lower limit plates 111, 112 according to the Fig. 1 mechanical elements are used, it is also within the scope of the invention that the limiting plates 111, 112 are moved by electrical or hydraulic means and their position is detected, for example, by sensors.

[0064] To apply a foam strip 22 to the inner tread 21 of a tire 2, adhesive is first applied to the inner tread 21 of the tire 2, which faces the profile 20 of the tire 2. The adhesive is applied, in particular, in the form of beads. In a further step, the foam strip 22 is inserted into the tire 2 and fixed to the inner tread 21. This can be done, for example, using a pressure roller of a strip cassette. Alternatively, the adhesive can be applied to the foam strip 22 before the foam strip 22 is inserted into the tire 2. The steps of applying the adhesive and the foam strip 22 can be carried out on the base part 10 of the pressing device 1.However, it is also within the scope of the invention that these steps are carried out on a separate device and the tire 2, which is equipped with adhesive and the foam strip 22, is then placed on the base part 10 of the pressing device 1.

[0065] The tire 2 is positioned on the base part 10 such that the limiting plates 111, 112 are aligned with the rim openings of the tire 2. In particular, the limiting plates 111, 112 are located within the rim opening when viewed from above.

[0066] In a further step, the height of the lower limiting plate 112 and the relative position of the upper limiting plate 111 to the lower limiting plate 112 are adjusted. For this purpose, for example, the height of the lower limiting plate to the surface of the base part 10 can first be adjusted using the adjusting element 14 until this height is greater than the distance between the lower rim opening of the tire 2 and the surface of the base part 10. As a result, the lower limiting plate 111 lies inside the tire 2. Subsequently, the relative distance between the lower and upper limiting plates 112, 111 can be adjusted. This distance is set so that the upper limiting plate 111 also lies inside the tire 2.

[0067] Alternatively, the relative distance between the upper and lower limit plates 111, 112 can be adjusted first and then the height of the lower limit plate to the base part can be adjusted.

[0068] The distance between the rim openings in the axial direction is known for the respective tire 2, so that the relative distance between the limiting plates 111, 112 can be predetermined accordingly. If this predetermined distance is known, the subsequent adjustment of the height of the lower limiting plate 112 can be carried out using an adjustment aid 16, such as the one shown in Fig. 1 shown fold-out arm.

[0069] After the limiting plates 111, 112 are positioned in the tire 2, the pressing element 110 is filled with fluid. As the pressing element 110 expands, particularly in the radial direction, the radial outer side of the pressing element 110 comes into contact with the inner side of the foam strip 22. If the tire 2 has been placed offset from the support device, namely the limiting plates 111, 112 and the associated fluid supply line 12, on the base part 10 of the pressing device 1, this contact causes the tire 2 to move into a position centered around the central axis of the pressing unit 10, in particular the limiting plates 111, 112. This movement is assisted by the centering elements 100 of the base part 10, particularly since this eliminates the need to overcome frictional forces when moving the tire 2 on the base part 10, or rather, these frictional forces can be minimized.

[0070] In Fig. Figure 8 shows a sectional view of a tire component. In the embodiment shown, the tire 2 has a foam strip 22 applied to the inner tread 21 of the tire 2. The inner tread 21 lies opposite the outer side of the tire 2, where the tread 20 is provided. This outer side is also referred to as the tire tread. The foam strip 22 is held to the inner tread 21 by adhesive 23.

[0071] The condition that Fig. 8 depicts the state in which the foam strip has not yet been pressed by the pressing device. This view shows that the adhesive beads originally applied to the inner tread 21 of the tire 2 or to the foam strip 22 form ridges 230. The reason for this is that the foam strip 22 is bonded to the curved inner tread 21 and eventually attempts to return to its original position, i.e., flat alignment.

[0072] After pressing the foam strip 22 with the pressing device 1 according to the invention, in contrast to the non-pressed state after Fig.8 Although residual stresses, i.e. the tendency to return to the initial state, also occur when a foam strip 22 is pressed on, the adhesive surface, i.e. the contact between adhesive 23 and inner tread 21 of the tire 2 on the one hand and adhesive 23 and foam strip 22 on the other hand, is increased by the pressing.

[0073] With increasing holding time, i.e. the time over which the force is applied to the foam strip by the pressing element 110, the adhesion of the foam strip 22 to the inner running surface 21 is further improved.

[0074] The present invention is not limited to the illustrated embodiments. For example, the shape of the pressing element and / or the design of the fluid supply may differ from the illustrated embodiments.

[0075] According to one embodiment, the pressing device is designed to accommodate a wide range of tire dimensions. Depending on the tire type, the pressing device, which can also be referred to as a foam pressing station, can be adjusted using two hand cranks. Tire types can be of different sizes. The parameters to be considered include the inner and outer diameter, as well as the sidewall height and tire width.

[0076] The main element of the press unit consists of a lower and an upper limit plate, each of which can be adjusted in height. To ensure correct adjustment and thus repeatability, the height adjustment uses a scale.

[0077] To begin the process, a pressing element, such as an inflatable ring made of plastic film, is inserted between the two limiting plates. This ultimately takes on the function of pressing the foam strip against the tire. In its initial position, this ring is folded in on itself, as all the air has been previously sucked out. This reduces the diameter to make it easier to place the tire on the table. It is not important whether the tire is placed centered. Once the ring is filled with air, the tire can center itself via ball transfer rollers, preferably integrated into the table.

[0078] The ring can be filled to a pressure that allows it to inflate and exert force on the foam strip. A certain maximum pressure can be specified that must not be exceeded to prevent the ring from bursting. Safety sensors can be installed to monitor the ongoing process to ensure this pressure is not exceeded.

[0079] Once the ring has been inflated and thus reached its working position, it presses the previously applied foam strip against the inner tread of the tire with a specific force. After a specific holding time, the air chamber is evacuated as completely as possible, and the tire can be removed from the foam pressing station.

[0080] The reason for holding the pressing force for a certain period of time is that better properties regarding the adhesion between the foam strip and the inner tread of the tire have been demonstrated. Reference symbol 1 pressing device 10 Base part 100 centering element 11 Press unit 110 Press element 111 upper limit plate 112 lower limit plate 113 Connecting element 114 connecting bridge 12 Fluid supply line 120 fluid guide channel 121 first supply channel 122 second supply channel 123 Fluid outlet opening 124 Line connection 13 Adjustment element upper plate 14 Adjustment element lower plate 15 Linear guide 16 Adjustment aid 17 Control unit 2 tires 20 Profile 21 inner tread 22 foam strips 23 Adhesive 230 jetty S fluid flow QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 113696528A

[0003] EP 2727713B1

[0004]

Claims

[1] Device for pressing a foam strip (22) onto the inner tread (21) of a tire (2), characterized by in that the device comprises a pressing unit (11) which comprises a support device and a pressing element (110), wherein the support device is a support device for the pressing element (110) and wherein the pressing element (110) represents an inflatable element which extends over at least part of the outer circumference of the support device and is expandable at least in the radial direction. [2] Device according to claim 1, wherein the pressing element (110) extends over the entire outer circumference of the support device. [3] Device according to one of claims 1 or 2, wherein the pressing element (110) in the inflated state represents a ring with a circular ring shape. [4] Device according to one of claims 1 to 3, wherein the pressing element (110) has at least one supply opening for inflation fluid in the radially inwardly facing inner side. [5] Device according to claim 4, wherein the feed opening extends over the entire circumference of the inside of the pressing element (110). [6] Device according to claim 1 to 5, wherein the support device comprises a first limiting plate (111) and a second limiting plate (112). [7] Device according to claim 6, wherein the first and second limiting plates (111, 112) are movably connected to one another via a connecting element (113) by means of which the distance between the limiting plates (111, 112) can be changed. [8] Device according to one of claims 6 or 7, wherein the pressing element (110) is fixed to the periphery of the first and second limiting plates (111, 112). [9] Device according to one of claims 1 to 8, wherein the pressing unit comprises a fluid supply line (12) for supplying the inflation fluid into the interior of the pressing element (110). [10] Device according to claim 9, wherein the fluid supply line (12) comprises a first supply channel (121) and a second supply channel (122) which are displaceable relative to one another, and at least one fluid outlet opening (123) is introduced into the first supply channel (121). [11] Device according to one of claims 1 to 10, wherein the device has a base part (10) for placing the tire (2) and the pressing unit (11) is provided on the base part (10). [12] Method for pressing a foam strip onto the inner tread (21) of a tire (2), characterized by that the method is carried out with a device according to one of claims 1 to 11. [13] A method according to claim 12, wherein the method comprises the step of inflating the pressing element (110) after introduction into the interior of the tire (2). [14] A method according to any one of claims 12 or 13, wherein the device comprises a first limiting plate (111) and a second limiting plate (112), and the method comprises the step of adjusting the distance between the first and second limiting plates (111, 112).

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