JP4723342B2 - Pneumatic tire and rim assembly - Google Patents

Description

  The present invention relates to an assembly of a pneumatic tire and a rim in which a band-shaped sound absorber made of a sponge material is disposed in a tire lumen.

  As one of tire noises, there is road noise generated in a frequency range of about 50 to 400 Hz, and the main cause is known as resonance vibration of air (cavity resonance) occurring in the tire lumen. Therefore, in order to reduce such road noise, the present applicant, for example, as shown in FIG. 11, a tire in which a band-shaped sound absorber b made of a sponge material extending in the tire circumferential direction within the tire lumen a is disposed. And a rim assembly c have been proposed (see, for example, Patent Document 1). The noise control body b can convert vibration energy of air in the tire lumen a into heat energy, and can effectively suppress cavity resonance in the tire lumen a.

JP 2002-67608 A

  By the way, in the general market, such an assembly c is often stored in the state of a composite in which the sound control body b is bonded to the tire in advance. However, sponge materials, particularly ether-based polyurethane sponges, which are preferable as the sound control body b, tend to be inferior in light resistance such as being easily deteriorated by ultraviolet rays. Therefore, when the composite is stored, there is a problem that the sponge material as the sound control body b is deteriorated by ultraviolet rays outdoors or indoors, and the required durability cannot be sufficiently exhibited.

The present invention has been devised in view of the above circumstances, and is based on the protection of at least the upper surface of the sound damper with a coating layer made of a specific resin, and prevents deterioration of the sound damper due to exposure. An object of the present invention is to provide an assembly of a pneumatic tire and a rim that can sufficiently exhibit the durability required for a sound control body.

According to the first aspect of the present invention, a rim, a pneumatic tire mounted on the rim, and a tire lumen surrounded by the rim and the pneumatic tire are fixed and extend in the tire circumferential direction. And a band-shaped noise control device made of a sponge material having a volume of 0.4 to 20% of the total volume of the tire lumen and facing toward the center of the tire lumen. A sound-damping body having an upper surface and a coating layer that covers and protects the upper surface of the sound- damping body, and the coating layer is formed by applying an emulsion of a silicon resin or a polyurethane resin. It is said.

In the invention of claim 2, the sponge material has open cells, and the coating layer seals open cells of the sponge material.
The invention according to claim 3 is characterized in that the sound damper is made of a polyurethane sponge material .
According to a fourth aspect of the present invention, the coating layer has a thickness of 0.10 to 0.50 mm.
According to a fifth aspect of the present invention, the sound damper is fixed to the inner surface of the tread, and the sound damper has a bottom surface on the inner surface of the tread and the upper surface facing the center side of the tire lumen. ,
In the tire meridian cross section including the tire axis,
The sound damper has a maximum thickness (tm) from the bottom surface to the top surface in a range of 5 to 45 mm, and the bottom surface width (W1) is larger than the maximum thickness value (tm). It has a horizontally long flat cross-sectional shape,
The top surface has a peak having the maximum value (tm) of the thickness, a valley bottom located on both sides of the peak and having a minimum thickness (ti), and from the peak to each valley bottom. A wave element composed of an extending inclined portion extends along a wavy curve repeated in the width direction, and both ends of the upper surface in the width direction terminate at the bottom of the valley or the inclined portion, and the both ends of the upper surface in the width direction. The thickness (te) from the bottom surface is characterized by being in the range of 1.0 to 15.0 mm.
The invention according to claim 6 is a composite body of a pneumatic tire and a sound damping body, and the sound damping device according to any one of claims 1 to 5 fixed to the pneumatic tire and an inner surface of the tread thereof. It is characterized by consisting of.

Note that the volume of the sound damper is an apparent volume determined from the outer shape of the noise damper, and includes the volume occupied by the internal bubbles. Further, the “total volume of the tire lumen” is determined as a value V approximately obtained by the following equation (1) in a no-load state in which the assembly is filled with normal internal pressure.
V = A × {(Di−Dr) / 2 + Dr} × π (1)
In Formula (1), “A” is a tire lumen area obtained by CT scanning of the tire lumen in the normal state, and “Di” is a maximum outer diameter of the tire lumen in the normal state shown in FIG. , “Dr” is the rim diameter, and “π” is the circumference. In addition, “regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. The maximum air pressure for JATMA and the table “TIRE LOAD LIMITS AT for TRA” The maximum value described in “VARIOUS COLD INFLATION PRESSURES”. If ETRTO, “INFLATION PRESSURE”. However, when the tire is for a passenger car, the pressure is uniformly set to 200 kPa in consideration of the actual use frequency.

In the present invention, the noise damper to be disposed in lumen tire, at least the upper surface of the noise damper made of sponge material is covered and protected by co computing layer. The coating layer is formed by applying an emulsion of a silicon resin or a polyurethane resin. For this reason, it is possible to prevent the sound absorber from being deteriorated by the ultraviolet rays even when the sound absorber is stored in a state of being stuck to the tire in the market or the like. As a result, the durability required for the sound control body can be sufficiently exhibited while maintaining the effect of reducing road noise.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pneumatic tire and rim assembly 1 according to the present embodiment includes a rim 2, a tire 3 attached to the rim 2, and a tire interior surrounded by the rim 2 and the tire 3. And a sound damper 4 fixed in the cavity i.

  The rim 2 has a well-known structure including an annular rim body 2a on which the bead portion 3b of the tire 3 is mounted, and a disk-shaped disk 2b for fixing the rim body 2a to the axle. In this example, the case where the regular rim prescribed | regulated by the said standards, such as JATMA, is illustrated.

  The tire 3 is a tubeless tire, and as shown in FIG. 3, a tread portion 3t, a pair of sidewall portions 3s extending inward in the tire radial direction from both ends thereof, and inner ends of the sidewall portions 3s. The tire inner surface 3i is covered with an inner liner made of low air permeable rubber. Thereby, an airtight tire lumen i is formed by the tire inner surface 3i and the rim inner surface 2i. Various tires can be applied as the tire 3 without being restricted by the internal structure or category. However, passenger car tires that are strongly required to be quiet in the passenger compartment, especially radial tires for passenger cars having a flatness ratio of 50% or less are preferably employed.

  The tire 3 is reinforced by a cord layer including a carcass 6 straddling between the bead portions 3b and 3b, and a belt layer 7 disposed radially outside the carcass 6 and inside the tread portion 3t.

  The carcass 6 is formed of one or more, for example, one carcass ply 6A in which organic fiber cords are arranged at an angle of, for example, 70 to 90 ° with respect to the tire circumferential direction. Both ends of the carcass ply 6 </ b> A are folded around the bead core 8. The belt layer 7 is formed of a plurality of, for example, two belt plies 7A and 7B in which steel cords are arranged at an angle of, for example, 10 to 40 ° with respect to the tire circumferential direction. The belt layer 7 is improved in belt rigidity by crossing steel cords between plies. Note that a known band layer or the like may be provided outside the belt layer 7 as necessary.

Next, the noise damper 4 is provided with a noise damper 10 formed of an elongated strip of sponge material extending in the tire circumferential direction, and a coating layer 11 for covering at least the upper surface 10B of the front Symbol noise damper 10 Consists of including. Of the peripheral surfaces of the sound damper 10, the surface on which the sound damper 4 is fixed is referred to as a bottom surface 10A, and the surface facing the center side of the tire lumen i is referred to as the upper surface 10B.

  The band-shaped sound control device 4 is bonded and fixed to the tire inner surface 3i or the rim inner surface 2i along the tire circumferential direction using a double-sided adhesive tape, an adhesive, or the like. As a result, the noise suppressor 4 is prevented from freely moving in the tire lumen i during traveling, preventing damage to the noise suppressor 4 and stably exhibiting the resonance suppression effect. In particular, it is preferable that the sound control device 4 is bonded to the tire inner surface 3i, particularly the tread inner surface 3ti, from the viewpoint of rim assembly. The tread inner surface 3ti means a surface of the tire inner surface 3i located at the tread portion 3t that contacts the road surface. In this specification, at least the width region TW in the tire axial direction in which the belt layer 7 is disposed. including. As a particularly preferable aspect, the sound control device 4 is attached so that the center of the width thereof is located on the tire equator C.

  The sound damper 10 has a substantially constant cross-sectional shape and extends in the tire circumferential direction. The “substantially constant cross-sectional shape” is used for the purpose of improving durability, and as shown in FIG. 2, tapered portions whose cross-sectional height gradually decreases are formed at both ends 10 e in the circumferential direction of the sound damper 10. It is because it has been. FIG. 2 shows a case in which a gap is formed between the end portions 10e and 10e of the sound damping body 10. However, by connecting the end portions 10e and 10e without any gap, The tool 4 may be formed in an annular shape. Further, as shown in FIG. 4 (A), the sound control device 4 may be spirally wound in the tire circumferential direction, and the sound control device 4 is divided into a plurality of pieces as shown in FIG. 4p may be intermittently arranged in the circumferential direction. Further, as shown in FIG. 4C, the sound control devices 4 may be arranged in a plurality of rows (for example, two rows).

  The sponge material forming the sound damping body 10 is a sponge-like porous structure. For example, in addition to a so-called sponge having open cells in which rubber or synthetic resin is foamed, animal fibers, plant fibers or synthetic fibers are used. Includes webs that are intertwined and connected together. The “porous structure” includes not only open cells but also closed cells. Preferably, a synthetic resin sponge such as an ether polyurethane sponge, an ester polyurethane sponge, or a polyethylene sponge, a rubber sponge such as a chloroprene rubber sponge (CR sponge), an ethylene propylene rubber sponge (EDPM sponge), or a nitrile rubber sponge (NBR sponge). Polyurethane sponges, particularly ether-based polyurethane sponges, are particularly preferred from the viewpoints of sound damping, light weight, foaming controllability, durability, and the like.

  If the specific gravity of the sponge material is too large, the tire weight is likely to increase. On the other hand, if the sponge material is too small, it is difficult to obtain sufficient strength and the effect of suppressing cavity resonance is reduced. From such a viewpoint, the lower limit of the specific gravity of the sponge material is preferably 0.005 or more, and more preferably 0.01 or more. The upper limit of the specific gravity is preferably 0.06 or less, more preferably 0.04 or less, and further preferably 0.03 or less.

  The volume Vs of the noise control body 10 is set to 0.4 to 20% of the total volume V of the tire lumen i. As described in Patent Document 1 described above, by securing 0.4% or more of the volume Vs of the noise control body 10 with respect to the total volume V of the tire lumen i, a remarkable 2 dB or more is obtained. Expected to reduce road noise. This noise reduction level can be said to be a value that can be clearly confirmed in the passenger compartment. From such a point of view, preferably, the volume Vs of the noise damper 10 is 1% or more, more preferably 2% or more, and more preferably 4% or more of the total volume V of the tire lumen i. On the other hand, if the volume Vs of the noise control body 10 exceeds 20% of the total volume V of the tire lumen i, the effect of reducing road noise will reach its peak, increase the cost, or deteriorate the weight balance of the assembly 1. It is easy to invite. From this point of view, the volume Vs of the sound damper 10 is particularly preferably 15% or less, more preferably 10% or less of the total volume V of the tire lumen i. In addition, such numerical limitation is not only in the case where the sound control device 4 is configured by one sound control body 10, but also in the case where it is formed by being divided into a plurality of or a plurality of sound control bodies 10, It has been confirmed that the same effect is exhibited if the total volume Vs is within the numerical range.

  Next, the cross-sectional shape and the like in the cross section in the width direction (the tire meridian cross section including the tire shaft) of the noise damper 10 are not particularly restricted, but as shown in FIG. 6, the bottom surface on the side bonded to the tread inner surface 3ti. The maximum value tm of the thickness t between 10A and the upper surface 10B facing the center of the tire lumen i is in the range of 5 to 45 mm, and the width W1 of the bottom surface 10A is larger than the maximum value tm of the thickness. It is formed with a large laterally flat cross-sectional shape. The maximum value tm and the width W1 of the thickness are measured in a state (normal temperature and normal pressure) before the rim assembly with the noise control device 4 attached to the tire 3. The maximum value tm of the thickness is measured in a direction perpendicular to the bottom surface 10A, and the width W1 is measured along the bottom surface 10A.

  The inventors performed a tire removal test on an assembly in which a noise control body having a rectangular cross section is arranged on the inner surface 3ti of the tread. And the damage condition of the sound control body 10 was investigated. As shown in FIG. 5, the tire removal test was performed by a plurality of workers using a tire changer (not shown) and a tire lever f. The operator is not informed in advance of the presence of the sound control body. In addition, many types of sample assemblies were used, including various sound absorbers with different maximum thicknesses tm and tires with different flatness ratios.

  When the tire 3 is removed from the rim 2, the tire lever f is inserted into the tire lumen i. The insertion length is determined depending on the type of tire (category, flatness, etc.), operator technique, wrinkles during operation, etc. Varies depending on the situation. However, as a result of the test, it was found that the number of damages of the sound control body is reduced in the assembly having the sound control body in which the maximum thickness tm is limited to 5 to 45 mm. The reason for this is that the insertion length of the tire lever f is limited by the general knowledge of the operator who tries to prevent the contact between the tire lever f and the tire inner surface 3i, and therefore the sound damper with a small thickness t is used. On the other hand, contact opportunities are expected to decrease. However, when the flat tire has a flatness ratio of 50% or less, the tire lever f tends to come into contact with the side surface of the sound control body more frequently.

Therefore, when further experiments were repeated, as shown in FIG. 6, in the tire meridian section,
(1) A peak 20t where the thickness t has a maximum value tm, a valley bottom 21b which is located on both sides of the peak 20t and has a minimum value ti, and each valley bottom from the peak 20t The upper surface 10B of the sound damper 10 extends along a wavy curve 24 in which the wave element 23 composed of the inclined portion 22 extending 21b is repeated in the width direction:
(2) The width direction both ends 10Be of the upper surface 10B terminate at the valley bottom portion 21b or the inclined portion 22; and (3) The thickness te from the bottom surface 10A of the width direction both ends 10Be of the upper surface 10B is Be in the range of 1.0 to 15.0 mm;
Thus, it has been found that the tire lever f can be prevented from being damaged.

  In other words, when the upper surface 10B extends along the wavy curve 24, the sound damping body 10 has alternating peaks 20 having a large thickness and valleys 21 having a small thickness. It is formed. In addition, both end portions of the sound damper 10 are terminated at the trough portion 21, and the thickness te of the both end portions from the bottom surface 10 </ b> A is restricted to a range of 1.0 to 15.0 mm. The peak portion 20 is defined by a portion having a thickness larger than the amplitude center line KL with respect to the amplitude center line KL of the wavy curve 24, and the valley portion 21 is defined by the amplitude center line KL. The thickness t is defined by a smaller portion.

  1, 3, 6, and 8 show a case where the wavy curve 24 has a trapezoidal wave shape as a first embodiment of the sound damper 10. In the first embodiment, as shown in FIG. 6, the wavy curve 24 has the peak 20t formed of a linear upper side 30 parallel to the bottom surface 10A and the valley bottom 21b parallel to the bottom 10A. The trapezoidal wave-like curve is formed by repeating the wave element 23 composed of the linear lower side 31 and the inclined portion 22 composed of the linear hypotenuse 32 in the width direction. The hypotenuse 32 can be provided with an arc portion having a radius of curvature that is sufficiently smaller than the entire length of the hypotenuse 32 at the connection with the upper side 30 and / or the lower side 31. Here, the radius of curvature sufficiently smaller than the entire length of the hypotenuse 32 means 42% or less of the total length of the hypotenuse 32, preferably 35% or less, more preferably 20% or less.

  As described above, both ends of the sound damper 10 are terminated at the valley 21 and the thickness te of both ends is regulated to 15.0 mm or less. Therefore, contact between the tire lever f and the sound control body 10 is further avoided. Moreover, the sound damper 10 is composed of gentle inclined portions 22 from both end portions thereof to the peak portion 20t. By such an inclined portion 22, as shown in FIG. 7, a portion that easily interferes with the tire lever f is removed. Accordingly, contact between the tire lever f and the sound control body 10 is further avoided. The inclined portion 22 approximates an arcuate locus fL drawn by the tip of the tire lever f. Therefore, even if the tire lever f comes into contact with the sound damping body 10, the frictional force between the tire lever f and the inclined portion 22 is small, and the tip of the tire lever f does not easily bite into the sound damping body 10. And by these interaction, the remarkable damage of the damping body 10 and peeling from the tire 3 of the damping body 10 can be prevented effectively.

  If the thickness te of the both ends exceeds 15.0 mm, both ends of the sound damper 10 are likely to interfere with the tire lever f. Therefore, the thickness te is preferably 15.0 mm or less, more preferably 10.0 mm or less, and even 7.0 mm or less from the viewpoint of preventing damage to the sound damper 10. However, when the thickness te is smaller than 1.0 mm, it is difficult to obtain an effect of improving the productivity of the sound damper 10, and therefore the thickness te is 1.0 mm or more, further 3.0 mm or more, 4.0 mm or more is preferable. Further, the minimum thickness ti is preferably 1.0 mm or more, more preferably 3.0 mm or more, and further preferably 4.0 mm or more from the viewpoint of improving productivity. In particular, the thickness te of the both end portions is equal to the minimum value ti of the thickness, that is, the end portions of the sound damping body 10 are terminated at the valley bottom 21b to prevent damage to the sound damping body 10. From the viewpoint of improving productivity. However, if the thickness is within the range, the thickness te is larger than the minimum value ti, that is, both end portions or one end portion of the sound damper 10 are terminated on the inclined portion 22 different from the valley bottom portion 21b. You may do it.

  In addition, in the wavy curve 24 that determines the contour shape of the upper surface 10B, if the amplitude H is too small, the surface area of the upper surface 10B becomes small and the resonance suppression effect in the tire lumen i tends to decrease, and conversely it is too large. However, the inclined portion 22 becomes steep, which is disadvantageous for preventing damage to the sound damper 10. From such a viewpoint, the lower limit value of the amplitude H is preferably 4 mm or more, more preferably 8 mm or more, and more preferably 10 mm or more, and the upper limit value is 44 mm or less, further 40 mm or less, further 35 mm or less, and further 30 mm. The following is preferred.

  1, 3, and 6, the number of peaks 20 t formed on the top surface 10 </ b> B of the sound damping body 10 is one, particularly the top surface 10 </ b> B is formed by one wave element 23, that is, the sound damping body 10. A case is shown in which both ends of each end at the valley bottom 21b. However, the number of peak portions 20t formed on the upper surface 10B may be two or more, and FIG. 8 shows an embodiment in which the number of formations, particularly, the upper surface 10B is formed by two wave elements 23.

  When the number of the peak portions 20t is 2 or more, the surface area of the upper surface 10B is increased, so that a higher resonance suppression effect can be exhibited. In addition, valleys 21 are formed between the peaks 20. The valley portion 21 facilitates deformation of the mountain portion 20 inward in the width direction when the tire lever f comes into contact with the inclined portion 22. Therefore, the sound control body 10 can be released from the tire lever f, and the biting of the tire lever f can be further suppressed. Moreover, since the trough part 21 exhibits a heat dissipation effect, it is also useful for preventing the thermal damper 10 from being thermally destroyed.

  If the width W1 of the bottom surface 10A is too large, the workability of attaching to the tire inner surface 3i tends to be lowered. From such a viewpoint, the width W1 of the bottom surface 10A is preferably 100% or less, more preferably 70% or less of the tread width TW.

  Further, as shown in FIG. 9, as the sound damping body 10, the wavy curve 24 may be a sine wave shape, and the same effect as in the first embodiment of the trapezoidal wave shape can be obtained. In such a case, in order to approximate the inclined portion 22 by the locus fL of the tire lever f, a ratio H / Wp between the wave pitch Wp, which is the width of the wave element 23, and the amplitude H is set to 0.3. In the following, it is more preferable to set it to 0.25 or less.

Then, at least the upper surface 10B of the noise damper 10 is covered and protected by a coating layer 11 made of tree fat material.

  Examples of such resin materials include acrylic resins, styrene-acrylic resins, polyurethane resins, polyester resins, alkyd resins, acrylic-ethylene composite resins, acrylic-urethane composite resins, and acrylic-olefin composite resins. , Colloidal silica-acrylic composite resin, colloidal silica-urethane composite resin, silicon resin, silicon-acrylic composite resin, silicon-urethane composite resin, ethylene ionomer resin, polyolefin ionomer resin, and the like. Then, the coating layer 11 is formed by applying these to the upper surface 10B in the form of an emulsion alone or in combination of two or more.

  When two or more kinds are mixed and used, at least one of acrylic resin, styrene-acrylic resin, polyurethane resin, acrylic-urethane composite resin, and acrylic-olefin composite resin is used. It is preferable.

In particular silicone resin, and polyurethane resin, in addition to resistance to weathering, since the excellent flexibility, it is possible to maintain the characteristics of the sponge material, maintaining the noise dampers of said noise damper 10 has Can preferably be employed. In addition, the silicone resin and the polyurethane resin are more preferable when the sound control body 10 is formed of a polyurethane sponge material because the compatibility with the sponge material is good and the peel strength from the sponge material is excellent. Can be adopted.

  Moreover, the coating layer 11 can be formed efficiently and easily by applying the resin material in an emulsion state. The coating layer 11 does not necessarily need to seal open cells of the sponge material at the upper surface 10B, and can also prevent deterioration of the sponge material by applying a prescribed amount of coating. Of course, applying an amount sufficient to block open cells in the sponge material can surely suppress deterioration inside the sponge material.

The thickness of the coating layer 11 is preferably in the range of 0.10 to 0.50 mm, is less than 0.10 mm, the effect of improving weather resistance is not sufficiently exhibited. Conversely it can not be expected further increase of the resistance to weather improving effect beyond 0.5 mm, with causes an increase in unnecessary cost, which is disadvantageous to the tire vibration due to road noise reducing effect, and the weight imbalance. The weight per unit area when the emulsion of the resin material is applied is preferably ²⁰ to 100 g / m ² .

The coating layer 11 is, from the viewpoint of resistance to weather propensity is preferably formed on all surfaces other than the bottom surface 10A, an end surface of the side and circumferential direction of the width direction of the noise damper 10, the tire storage in sun is less likely to hit directly, the effect of improving weather resistance is small. That is, if the upper surface 10B that is likely to be directly hit by the sun is covered, the deterioration can be sufficiently suppressed, and the strength reduction due to the deterioration of the sound damper 10 during storage can be prevented. For this reason, it is preferable not to form the coating layer 11 on the side surface and the end surface of the sound damper 10 from the viewpoint of suppressing an increase in weight and cost or suppressing an increase in temperature of the sound damper 10 due to significant heat.

  On the other hand, since the coating layer 11 is thin and can pass sound vibrations, it can pass vibration waves of air generated in the tire lumen i and transmit them to the sound control body 10 (sponge material). As a result, part of the vibration energy of the cavity resonance is consumed as thermal energy, and road noise can be reduced. Further, since the coating layer 11 is thin, the flexibility of the sound damper 10 can be maintained, so that the rim assembly property is not deteriorated and the steering stability is not affected. Further, since the coating layer 11 is in close contact with the sound damping body 10, the above-described effect obtained by making the upper surface 10B of the sound damping body 10 into a wavy curve can be exhibited as it is.

  The sound control device 4 configured as described above can be fixed to the tire inner surface 3i by various methods, but it is particularly preferable to adhere the double-sided adhesive tape from the viewpoint of cost and workability. And the sound control tool 4 is adhere | attached on the pneumatic tire 3, and these can also be set sale etc. as a composite_body | complex of the pneumatic tire 3 and the sound control tool 4. FIG. In order to improve adhesiveness, it is desirable that the tire inner surface 3i be finished smooth. Usually, the tire inner surface 3i is formed with a ridge formed by transferring an exhaust groove formed on the surface of the vulcanization bladder, but it is desirable to remove and smooth the ridge. Also, by using a bladder with no exhaust groove on the surface, the tire inner surface can be finished flat from the beginning. In order to further improve the adhesion to the tire inner surface 3i, the tire is preferably vulcanized without applying a release agent to the tire inner surface 3i.

  Although the embodiment of the present invention has been described above, the above embodiment is merely an example, and it is needless to say that the present invention can be modified and implemented in various modes.

  A prototype of a tire and a noise control device is made by adhering a sound control device having the specifications shown in Table 1 to the inner surface of a tread of a radial tire for a passenger car (215 / 45R17). Went.

The sound control device uses an ether polyurethane sponge with a specific gravity of 0.016 (product number E16, Maruzu). Both ends in the tire circumferential direction are tapered at 45 ° as shown in FIG. gave. In each example, the total volume V of the tire lumen, the volume Vs and the cross-sectional shape (shown in FIG. 10) of the sound damper are the same, and the total volume V of the tire lumen is 25318 cm ³ . The volume Vs is 2300 cm ³ and the ratio Vs / V is 9.1%. Further, the sound control tool and the inner surface of the tread were bonded using a double-sided adhesive tape (manufactured by Nitto Denko Corporation, model 5000NS). The tire was vulcanized without applying a release agent to the inner surface of the tire, and a bladder without an exhaust groove on the surface was used as a bladder for forming the inner surface of the tire. For this reason, the inner surface of the tire is finished flat, and good adhesion to the sound control tool is obtained.

  Moreover, in the resin material in the coating layer in the table, SiO (silicon) was formed by applying a silicon paint (model number SE1980) manufactured by Toray Dow Corning Co., Ltd. with a roll coater. PU (polyurethane) was formed by applying polyurethane paint (model number HUX980) manufactured by Adeka Co., Ltd. with a roll coater. Further, after coating, it was dried in a drying oven at 80 ° C. for 20 minutes. In Examples 1 to 10, a coating layer is formed only on the upper surface, and in Example 11, a coating layer is formed on the entire surface.

  In addition, a noise suppression sample was cut from the noise suppression device before bonding to a length of 200 mm, and the anti-exposure performance test was performed on the noise suppression sample.

(1) Noise performance:
The composite is mounted on all wheels of a vehicle (2000 cc domestic FR car) with internal pressure (200 kPa) and rim (17 × 7 JJ), and a road noise measurement path (asphalt rough road) with one passenger. The vehicle interior noise when traveling at a speed of 60 km / h is measured at the driver's seat window side ear position, and the sound pressure level of the peak value of the air column resonance sound near 240 Hz is an increase / decrease value based on Comparative Example 1. Indicated. -(Minus) display means a reduction in road noise.

(2) Exposure resistance:
Using a sunshine carbon arc lamp type light resistance and weather resistance tester stipulated in JIS B7753, artificial light irradiation (90 minutes) and water spray (10 minutes) approximate to sunlight at a temperature of 63 ° C The cycle was repeated. Then, during the exposure time (24 to 300 hours), the weight reduction amount of the sound control body due to the deteriorated portion of the sponge material powdered and dropped off was measured. The smaller the weight loss, the better the exposure resistance.

  As shown in the table, it can be confirmed that the formation of the coating layer can prevent deterioration due to exposure of the sound control tool while sufficiently exhibiting the road noise reduction effect. In particular, in order to sufficiently exhibit the effect of preventing deterioration, it can be confirmed that the thickness of the coating layer is preferably 0.10 mm or more as compared with Examples 2 and 4 and Examples 7 and 9. . Further, as compared with Examples 1, 3, 5 and Examples 6, 8, and 10, even if the coating layer thickness exceeds 0.5 mm, no further increase in the effect of preventing deterioration can be expected, and conversely the weight increase. It can be confirmed that this is disadvantageous. Moreover, as compared with Examples 1-5 and Examples 6-10, it can be confirmed that there is almost no difference in the deterioration prevention effect between the silicon resin and the polyurethane resin. Further, as compared with Examples 6 and 11, it can be confirmed that if the coating layer is formed on the upper surface, the deterioration preventing effect substantially equivalent to that formed on the entire surface can be obtained.

It is sectional drawing which shows the assembly of the pneumatic tire and rim | limb of this invention. It is the II end view. It is an expanded sectional view showing the composite of a tire and a sound control body. (A)-(C) are the perspective views which show schematically the other example of the formation state of a damping body. It is sectional drawing explaining the operation | work which removes a tire from a rim | limb using a tire lever. It is an enlarged view of a sound control body. It is a fragmentary sectional view explaining the positional relationship between a sound control body and a tire lever. It is sectional drawing which shows the other example of a damping body. It is sectional drawing which shows the other example of a noise suppression body. It is sectional drawing which shows the cross-sectional shape and dimension of a noise suppression body used for Table 1. FIG. It is a fragmentary sectional view of the tire assembly which shows an example of the conventional noise suppression tool.

Explanation of symbols

2 Rim 3 Pneumatic tire 3ti Tread inner surface 4 Damping tool 10 Damping body 10e Both ends 10A in the circumferential direction Bottom surface 10B Top surface 11 Coating layer 20 Summit 21 Valley bottom 22 Slope 23 Wave element 24 Wavy curve i Tire lumen

Claims (6)

A rim, a pneumatic tire attached to the rim, and a band-shaped sound damping tool fixed in a tire lumen surrounded by the rim and the pneumatic tire and extending in the tire circumferential direction,
The sound damper is made of a sponge material having a volume of 0.4 to 20% of the total volume of the tire lumen, and has a top surface facing the center side of the tire lumen, and the noise damper It said top surface comprising a coating layer which covers protection,
The assembly of a pneumatic tire and a rim, wherein the coating layer is formed by applying an emulsion of a silicone resin or a polyurethane resin .
  The pneumatic tire and rim assembly according to claim 1, wherein the sponge material has open cells, and the coating layer seals open cells of the sponge material. The pneumatic tire and rim assembly according to claim 1 or 2, wherein the sound damper is made of a polyurethane sponge material .
  The pneumatic tire and rim assembly according to any one of claims 1 to 3, wherein the coating layer has a thickness of 0.10 to 0.50 mm. The sound control tool is fixed to the inner surface of the tread, and the sound control body has a bottom surface on the inner surface side of the tread and the upper surface facing the center side of the tire lumen,
In the tire meridian cross section including the tire axis,
The sound damper has a maximum thickness (tm) from the bottom surface to the top surface in a range of 5 to 45 mm, and the bottom surface width (W1) is larger than the maximum thickness value (tm). It has a horizontally long flat cross-sectional shape,
The top surface has a peak having the maximum value (tm) of the thickness, a valley bottom located on both sides of the peak and having a minimum thickness (ti), and from the peak to each valley bottom. A wave element composed of an extending inclined portion extends along a wavy curve repeated in the width direction, and both ends of the upper surface in the width direction terminate at the bottom of the valley or the inclined portion, and the both ends of the upper surface in the width direction. The pneumatic tire and rim assembly according to any one of claims 1 to 4, wherein a thickness (te) from the bottom surface is in a range of 1.0 to 15.0 mm.   A composite of a pneumatic tire and a sound control body, comprising the pneumatic tire and the sound control tool described in any one of claims 1 to 5 fixed to the inner surface of the tread of the pneumatic tire.

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