Method for manufacturing tire with sound absorbing material

Abstract

To provide a method for manufacturing a tire with sound absorbing material that enables appropriate and easy assembly work of attaching a sound absorbing member to an inner peripheral surface of a tire body such that end portions thereof are in close contact with each other.SOLUTION: This method for manufacturing a tire with sound absorbing material comprises a step of attaching a sound absorbing material 21 having one end 21a and the other end 21b to an inner peripheral surface 11a of a tire body 1 such that a sound absorbing material non-attachment region 11b where the sound absorbing material 21 is not attached is formed between the one end 21a and the other end 21b along a circumferential direction of the tire, and a step of arranging a sound absorbing auxiliary piece 22 having a length L21 in the circumferential direction of the tire based on a length L2 in the circumferential direction of the tire of the sound absorbing material non-attachment region 11b.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a tire with sound-absorbing material. [Background technology]

[0002] BACKGROUND ART Conventionally, a method for manufacturing a tire with sound-absorbing material is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a method for manufacturing a tire with sound-absorbing material, which includes a step of attaching a noise damper, which is longer than the length of the inner circumferential surface, to the inner circumferential surface of the tire body in an annular shape by butting the end faces together. In the above-mentioned Patent Document 1, the noise damper is manufactured by cutting a linear sponge roll so that it is longer than the length of the inner circumferential surface of the tire body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-202856 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, a straight sponge roll is cut to a length longer than the length of the inner circumferential surface of the tire body to manufacture a noise damper, so the sponge roll needs to be cut with precision. However, when cutting the sponge roll to a length longer than the length of the inner circumferential surface of the tire body, the longer the length of the sponge roll to be cut, the more likely errors are to accumulate when measuring the length of the sponge roll, which is prone to stretching, making it difficult to cut the sponge roll with precision. This poses a problem in that it is difficult to properly and easily assemble the sound-absorbing member to the inner circumferential surface of the tire body so that the ends are in close contact with each other.

[0006] This invention has been made to solve the above-mentioned problems, and one object of this invention is to provide a method for manufacturing a tire with sound-absorbing material that enables the work of assembling the sound-absorbing member to the inner surface of the tire body so that the ends are in close contact with each other to be performed appropriately and easily. [Means for solving the problem]

[0007] In order to achieve the above object, a method for manufacturing a tire with sound-absorbing material according to one aspect of the present invention comprises the steps of: attaching the sound-absorbing material having one end and the other end to the inner surface of the tire body so that a sound-absorbing material-free area where no sound-absorbing material is attached is formed along the circumferential direction of the tire between the one end and the other end; and arranging a sound-absorbing auxiliary piece having a length in the circumferential direction of the tire based on the length in the circumferential direction of the tire of the sound-absorbing material-free area.

[0008] In one aspect of the present invention, a method for manufacturing a tire with sound-absorbing material includes disposing a sound-absorbing auxiliary piece having a circumferential length based on the circumferential length of a non-sound-absorbing-material region where no sound-absorbing material is attached. This allows the use of a sound-absorbing auxiliary piece having a short length corresponding to the non-sound-absorbing-material region where no sound-absorbing material is attached. Since the length of the sound-absorbing auxiliary piece is short, errors are less likely to accumulate when measuring the length of the sound-absorbing auxiliary piece compared to when the length is long, and forming errors (errors during cutting) can be reduced. This allows the sound-absorbing auxiliary piece to be formed (cut out) with high precision as a sound-absorbing member. This allows the sound-absorbing auxiliary piece with a circumferential length formed with high precision to be placed in the non-sound-absorbing-material region, allowing the sound-absorbing member to be properly and easily assembled to the inner circumferential surface of the tire body. As a result, the work of assembling the sound-absorbing member to the inner circumferential surface of the tire body so that the ends are in close contact with each other can be properly and easily performed.

[0009] If the sound-absorbing member is too long relative to the length of the inner circumferential surface of the tire body, the ends of the sound-absorbing member will overlap at the connection points of both circumferential ends of the sound-absorbing member, or the sound-absorbing member will become wavy on the inner circumferential surface of the tire. In this case, the sound-absorbing member cannot be brought into close contact with the inner circumferential surface of the tire body, and there is a risk that the sound-absorbing member will fall off. Furthermore, if the sound-absorbing member is too short relative to the length of the inner circumferential surface of the tire body, the both circumferential ends of the sound-absorbing member will not abut, in which case the sound-absorbing performance of the sound-absorbing member will decrease and the sound-absorbing member will be more likely to fall off. In the method for manufacturing a tire with sound-absorbing material according to one aspect of the present invention, as described above, by accurately forming short auxiliary sound-absorbing pieces corresponding to the non-sound-absorbing material areas where no sound-absorbing material is attached and arranging them between one end and the other end of the sound-absorbing material, the sound-absorbing material can be properly and easily assembled to the inner circumferential surface of the tire body so that the ends are in close contact with each other, thereby preventing the sound-absorbing material from falling off the inner circumferential surface of the tire body and preventing a decrease in sound-absorbing performance.Furthermore, it is also possible to effectively prevent the need for re-attachment of the sound-absorbing material due to the sound-absorbing material being too long or too short and not being able to be attached properly.

[0010] The method for manufacturing a tire with sound-absorbing material according to the above aspect preferably further includes the steps of measuring the circumferential length of the non-sound-absorbing material region of the tire, and forming the auxiliary sound-absorbing piece based on the measured circumferential length of the non-sound-absorbing material region. This configuration allows a short auxiliary sound-absorbing piece to be formed based on the measurement results (actual measurements) of the non-sound-absorbing material region where no sound-absorbing material is attached, thereby enabling the auxiliary sound-absorbing piece to be formed more accurately as a sound-absorbing member. Furthermore, even if there are individual differences in the inner circumferential length of the tire body, it is possible to accurately form the auxiliary sound-absorbing piece of an appropriate length.

[0011] In the method for manufacturing a tire with sound-absorbing material that includes the step of measuring the circumferential length of the non-sound-absorbing material region, preferably, in the step of arranging the auxiliary sound-absorbing piece, the auxiliary sound-absorbing piece is compressed and fitted into the non-sound-absorbing material region. With this configuration, the auxiliary sound-absorbing piece is compressed and fitted into the non-sound-absorbing material region that is between one circumferential end and the other circumferential end of the sound-absorbing material that is attached to the inner circumferential surface of the tire body, and therefore, the elastic force of the fitted auxiliary sound-absorbing piece that attempts to restore itself in the circumferential direction makes it possible to assemble the sound-absorbing material and the auxiliary sound-absorbing piece into the inner circumferential surface of the tire body so that they are in reliable close contact with each other in the circumferential direction.

[0012] The method for manufacturing a tire with sound-absorbing material according to the above aspect preferably further includes a step of forming the length from one end to the other end of the sound-absorbing material to be shorter than the length of the inner circumferential surface of the tire body in the circumferential direction of the tire, prior to the step of attaching the sound-absorbing material. With this configuration, when the sound-absorbing material formed to be shorter than the length in the circumferential direction of the tire is attached to the inner circumferential surface of the tire body, it is possible to reliably provide a sound-absorbing material-free area in which the sound-absorbing auxiliary piece is to be arranged.

[0013] The method for manufacturing a tire with sound-absorbing material according to the above aspect preferably further includes, prior to the step of arranging the auxiliary sound-absorbing piece, a step of applying an adhesive to at least one of one end surface portion and the other end surface portion of the auxiliary sound-absorbing piece that abuts against one end surface and the other end surface of the sound-absorbing material in the circumferential direction of the tire. With this configuration, the circumferential end surface of the auxiliary sound-absorbing piece can be adhered to the circumferential end surface of the sound-absorbing material with adhesive, with the auxiliary sound-absorbing piece arranged between the one end and the other end of the sound-absorbing material in the circumferential direction, thereby effectively preventing the auxiliary sound-absorbing piece from falling off the inner circumferential surface of the tire body.

[0014] In the method for manufacturing a tire with sound-absorbing material that includes the step of measuring the circumferential length of the non-sound-absorbing material region, preferably, in the step of measuring the circumferential length of the non-sound-absorbing material region, a distance sensor arranged radially inward of the inner circumferential surface of the tire body is used to measure the distance to the inner surface of the sound-absorbing material attached to the inner circumferential surface of the tire body and the distance to the inner circumferential surface of the tire body, thereby measuring the circumferential length of the non-sound-absorbing material region based on the results of detecting the positions of one end and the other end of the sound-absorbing material in the tire circumferential direction. With this configuration, the length of the non-sound-absorbing material region on the inner circumferential surface of the tire body where no sound-absorbing material is attached can be easily and accurately measured by measurement using the distance sensor, and therefore the circumferential length of the auxiliary sound-absorbing piece to be placed in the non-sound-absorbing material region can be easily and accurately obtained.

[0015] In a method for manufacturing a tire with sound-absorbing material, the circumferential length of the non-sound-absorbing material region is measured based on the results of detecting the positions of one end and the other end of the sound-absorbing material in the tire circumferential direction, preferably, in the step of measuring the circumferential length of the non-sound-absorbing material region, the tire body is rotated relative to the distance sensor while measuring the distance to the inner surface of the sound-absorbing material attached to the inner circumferential surface of the tire body and the inner circumferential surface of the tire body using the distance sensor, thereby measuring the circumferential length of the non-sound-absorbing material region based on the relative rotation angle of the tire body and the measurement results from the distance sensor. With this configuration, the length of the non-sound-absorbing material region on the inner circumferential surface of the tire body can be measured using the distance sensor while rotating the tire body relative to the distance sensor, making it easy to measure the entire inner circumferential surface of the tire body.

[0016] In this case, preferably, in the step of measuring the circumferential length of the region without sound-absorbing material, the tire body is rotated relative to the distance sensor while measuring the distance to the inner circumferential surface of the tire body to obtain the diameter of the inner circumferential surface of the tire body, and the circumferential length of the region without sound-absorbing material is measured based on the obtained diameter of the inner circumferential surface of the tire body and the relative rotation angle of the tire body corresponding to the portion of the inner circumferential surface of the tire body where sound-absorbing material is not attached. With this configuration, even if the diameter of the tire body is not uniform due to individual differences in tires, the diameter (radius) of the inner circumferential surface of the tire body can be obtained for each tire using the distance sensor, and therefore the circumferential length of the region without sound-absorbing material can be obtained with high accuracy by multiplying the diameter (radius) of the inner circumferential surface of the tire body by the rotation angle.

[0017] In a method for manufacturing a tire with sound-absorbing material, the circumferential length of the non-sound-absorbing material region is measured based on the results of detecting the positions of one end and the other end of the sound-absorbing material in the tire's circumferential direction. Preferably, in the step of measuring the circumferential length of the non-sound-absorbing material region, a distance sensor is used to measure the distance to the inner surface of the sound-absorbing material attached to the inner circumferential surface of the tire body and the distance to the inner circumferential surface of the tire body, thereby inspecting the state of attachment of the sound-absorbing material and measuring the circumferential length of the non-sound-absorbing material region. This configuration allows the state of attachment of the sound-absorbing material to be inspected simultaneously with the measurement to obtain the circumferential length of the non-sound-absorbing material region on the inner circumferential surface of the tire body. Therefore, the process of measuring the non-sound-absorbing material region and the process of inspecting the attachment state can be performed in parallel, thereby reducing work time. Furthermore, if the inspection reveals that the sound-absorbing material is not properly attached, the sound-absorbing material attachment process can be redone before the sound-absorbing auxiliary piece is prepared and placed in the non-sound-absorbing material region. As a result, it is possible to prevent a decrease in the efficiency of the work of assembling the sound-absorbing member.

[0018] In the manufacturing method for a tire with sound-absorbing material that includes the step of forming the auxiliary sound-absorbing piece, preferably, the step of forming the auxiliary sound-absorbing piece forms the auxiliary sound-absorbing piece having a trapezoidal shape when viewed in the direction of the tire main body rotation axis. With this configuration, the auxiliary sound-absorbing piece can be configured so that the circumferential length of its radially inner surface is shortened and the circumferential length of its radially outer surface is lengthened to fit the shape of the non-sound-absorbing material-attached region, which is the gap between one end and the other end of the arc-shaped sound-absorbing material in the circumferential direction. This allows the auxiliary sound-absorbing piece to be fitted between one end and the other end of the sound-absorbing material in the circumferential direction so that the degree of radial compression of the auxiliary sound-absorbing piece is uniform. This also effectively prevents the auxiliary sound-absorbing piece from falling off the inner circumferential surface of the tire main body.

[0019] In the manufacturing method of a tire with sound-absorbing material that includes the step of forming the auxiliary sound-absorbing pieces, preferably, in the step of forming the auxiliary sound-absorbing pieces, the auxiliary sound-absorbing pieces are formed from a sponge material of the same quality as the sound-absorbing material formed from sponge material. This configuration allows the sound-absorbing material and the auxiliary sound-absorbing pieces to be formed by cutting the same sponge material, thereby efficiently forming the sound-absorbing material and the auxiliary sound-absorbing pieces. Furthermore, since a sound-absorbing member made of the same sponge material is provided on the inner circumferential surface of the tire body, uniform sound-absorbing performance can be achieved around the entire circumference of the tire body. [Effects of the Invention]

[0020] According to the present invention, as described above, the work of assembling the sound-absorbing member onto the inner circumferential surface of the tire body so that the ends are in close contact with each other can be performed appropriately and easily. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic cross-sectional view showing a tire with sound-absorbing material according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the tire with sound-absorbing material taken along line II-II in FIG. [Figure 3] 1 is an enlarged view showing an auxiliary sound-absorbing piece of a tire with sound-absorbing material according to one embodiment of the present invention. [Figure 4] 1 is a perspective view showing an auxiliary sound-absorbing piece of a tire with sound-absorbing material according to one embodiment of the present invention. FIG. [Figure 5] 1 is a flowchart illustrating the steps of assembling a sound-absorbing member in a method for manufacturing a tire with sound-absorbing material according to one embodiment of the present invention. [Figure 6] 1 is a cross-sectional view showing a state before a sound-absorbing material is attached to a tire body according to an embodiment of the present invention. [Figure 7] 4A to 4C are cross-sectional views showing a process of attaching a sound-absorbing material to a tire body according to one embodiment of the present invention. [Figure 8] 1 is a cross-sectional view illustrating a process for measuring the length in the circumferential direction of the tire of an area on the inner circumferential surface of a tire body where sound-absorbing material is not attached according to one embodiment of the present invention. FIG. [Figure 9] 1 is a cross-sectional view illustrating a process for measuring the length in the circumferential direction of the tire of an area on the inner circumferential surface of a tire body where sound-absorbing material is not attached according to one embodiment of the present invention. FIG. [Figure 10] 1 is a cross-sectional view illustrating a process for measuring the length in the circumferential direction of the tire of an area on the inner circumferential surface of a tire body where sound-absorbing material is not attached according to one embodiment of the present invention. FIG. [Figure 11] 10A and 10B are cross-sectional views illustrating a process of fitting an auxiliary sound absorbing piece according to one embodiment of the present invention. [Figure 12] 5A to 5C are diagrams illustrating the process of forming (cutting out) the auxiliary sound absorbing piece according to one embodiment of the present invention. [Figure 13] FIG. 2 is a perspective view showing the shape (rectangular parallelepiped shape) of the auxiliary sound absorbing piece before assembly according to one embodiment of the present invention. [Figure 14] 10A to 10C are diagrams illustrating a process of applying adhesive to the end surface of an auxiliary sound absorbing piece according to one embodiment of the present invention. [Figure 15] FIG. 10 is a perspective view showing the shape (trapezoidal shape) of an auxiliary sound absorbing piece before assembly according to a modified embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] (Configuration of tires with sound-absorbing material) The configuration of a tire 100 with sound-absorbing material according to an embodiment of the present invention will be described with reference to FIGS.

[0024] As shown in Figures 1 and 2, the tire 100 with sound-absorbing material is attached so as to surround the outer periphery of a wheel 3, is filled with air, and is configured to support a load by air pressure. In other words, the tire 100 with sound-absorbing material is a pneumatic tire. The tire 100 with sound-absorbing material is attached to a moving body via the wheel 3 so as to rotate about a rotation axis A. The moving body is, for example, a vehicle such as a passenger car, truck, or bus. The vehicle moves by being driven by a drive unit including, for example, at least one of an engine and a motor.

[0025] The tire 100 with sound-absorbing material includes a tire body 1 and a sound-absorbing member 2. As shown in Fig. 2, the sound-absorbing member 2 is provided inside the tire body 1 in a circumferential shape along the circumferential direction (direction θ).

[0026] The tire body 1 includes a tread portion 11, a sidewall portion 12, and a bead portion 13. The tread portion 11 is the portion that comes into contact with the ground, and has an uneven tread pattern formed on its outer surface. The sidewall portion 12 is connected to the tread portion 11 and forms the side surface of the tire body 1. The bead portion 13 comes into contact with the wheel 3 and is configured to fix the tire body 1 to the wheel 3.

[0027] The sound-absorbing member 2 absorbs noise generated from the tire body 1. For example, the sound-absorbing member 2 absorbs noise generated in a frequency range of approximately 200 to 250 Hz due to air column resonance (cavity resonance) inside the tire body 1 when a mobile object is running. The sound-absorbing member 2 is attached to the inner circumferential surface 11a of the tire body 1. Specifically, the sound-absorbing member 2 is attached circumferentially to the inner circumferential surface 11a on the inside of the tread portion 11 of the tire body 1.

[0028] In this embodiment, the sound-absorbing member 2 includes a sound-absorbing material 21 and an auxiliary sound-absorbing piece 22, as shown in FIGS. 2 to 4. The sound-absorbing material 21 is attached to the inner circumferential surface 11a of the tire body 1, and has a circumferential length L1 (see FIG. 2) that is shorter than the length L0 (see FIG. 6) of the inner circumferential surface 11a of the tire body 1. The auxiliary sound-absorbing piece 22 is fitted between one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21 that is attached to the inner circumferential surface 11a of the tire body 1. As shown in FIG. 2, the auxiliary sound-absorbing piece 22 has a circumferential length L2 that is shorter than the circumferential length L1 of the sound-absorbing material 21.

[0029] As shown in Fig. 1, the sound-absorbing member 2 has a width Wa, which is the length in the rotation axis direction (Z direction), and a thickness t, which is the length in the radial direction (R direction). The width Wa is, for example, approximately 60 mm or more and 100 mm or less. The thickness t is, for example, approximately 10 mm or more and 30 mm or less. The circumferential length of the sound-absorbing member 2 is the same length L0 as the circumferential length L0 of the inner circumferential surface 11a of the tire body 1.

[0030] The sound-absorbing material 21 and the auxiliary sound-absorbing pieces 22 that make up the sound-absorbing member 2 are made of the same material. The sound-absorbing member 2 is made of, for example, a sponge material. The sound-absorbing member 2 is made of, for example, a sponge material that contains ether-based polyurethane. The sound-absorbing member 2 is also attached without gaps over the entire circumferential direction of the inner circumferential surface 11a of the tire main body 1.

[0031] 1 to 4, in this embodiment, the sound absorbing auxiliary piece 22 is fitted between one circumferential end 21a and the other circumferential end 21b of the sound absorbing material 21 in a state of being compressed in the circumferential direction. In other words, the sound absorbing auxiliary piece 22 before assembly (before compression) has a length L21 (see FIG. 11) in the circumferential direction (where L21>L2), relative to the length L2 (see FIG. 2) between one circumferential end 21a and the other circumferential end 21b of the sound absorbing material 21. This point will be described in detail in the manufacturing method of a tire with sound absorbing material, which will be described later.

[0032] The length L2 is, for example, not less than 20 mm and not more than 300 mm. Preferably, the length L2 is not less than 20 mm and not more than 100 mm. More preferably, the length L2 is not less than 20 mm and not more than 50 mm.

[0033] Furthermore, the length L21 is, for example, 5 mm to 30 mm longer than the length L2, and preferably 10 mm to 15 mm longer than the length L2.

[0034] It is preferable that the lengths L2 and L21 are approximately the same regardless of the inner diameter of the tire body 1. In other words, regardless of the inner diameter of the tire body 1, the sound-absorbing material 21 is formed to have a length such that one end 21a and the other end 21b in the circumferential direction are separated by approximately the same length L2 when attached to the inner circumferential surface 11a of the tire body 1. This makes it possible to fit a sound-absorbing auxiliary piece 22 of approximately the same length L21 between one end 21a and the other end 21b of the sound-absorbing material 21 regardless of the inner diameter of the tire body 1. As a result, handling of the sound-absorbing auxiliary piece 22 when fitting it between one end 21a and the other end 21b of the sound-absorbing material 21 can be easily performed.

[0035] The sound-absorbing auxiliary piece 22 is fitted between one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21 in a state in which it is compressed in the circumferential direction at a higher compression rate than the sound-absorbing material 21. The compression rate is the ratio ((L21-L2) / L21) of the length (L21-L2) that is shortened by compression after the sound-absorbing material 21 and the sound-absorbing auxiliary piece 22 are assembled to the tire body 1 to the natural length (L21) before the sound-absorbing material 21 and the sound-absorbing auxiliary piece 22 are assembled to the tire body 1. In other words, the larger the value of the compression rate, which is the ratio of the shortening before and after compression, the more compressed the state is, and the higher the compression rate. In this embodiment, for example, the compression rate ((L21-L2) / L21) is preferably 0.1 or more and 0.7 or less. The compression rate ((L21-L2) / L21) is more preferably 0.3 or more and 0.5 or less.

[0036] (Manufacturing method for tires with sound-absorbing material) Next, a method for manufacturing a tire with sound absorbing material will be described with reference to FIG. 2 and FIGS.

[0037] In the manufacturing method for a tire with sound-absorbing material, the sound-absorbing member 2 is assembled to the inner circumferential surface 11a of the tire body 1 according to the sound-absorbing member assembly procedure shown in Fig. 5, thereby manufacturing the tire with sound-absorbing material 100 shown in Fig. 2. Note that the work of assembling the sound-absorbing member 2 to the inner circumferential surface 11a of the tire body 1 may be performed by a worker, or may be performed by a manufacturing device equipped with a robot or the like.

[0038] In step S1 of FIG. 5, the sound-absorbing material 21 is formed to have a length L1 that is shorter than the length L0 of the inner circumferential surface 11a of the tire body 1. In other words, the length from one end 21a to the other end 21b of the sound-absorbing material 21 is formed to be shorter than the circumferential length of the inner circumferential surface 11a of the tire body 1. The length L0 of the inner circumferential surface 11a of the tire body 1 is calculated from the design value of the inner diameter of the tire body 1. In other words, the length L0 is calculated by L0 = (inner diameter (diameter) of the tire body 1) × π. The length L1 is shorter than the length L0 by, for example, 20 mm or more and 300 mm or less. Preferably, the length L1 is shorter than the length L0 by 20 mm or more and 100 mm or less. More preferably, the length L1 is shorter than the length L0 by 20 mm or more and 50 mm or less. The sound-absorbing material 21 is formed, for example, by cutting out the sound-absorbing material 21 using a cutting method similar to the cutting method of the auxiliary sound-absorbing piece 22 described below.

[0039] In step S2 of FIG. 5, the formed sound-absorbing material 21 is attached to the inner circumferential surface 11a of the tire body 1, as shown in FIGS. 6 and 7. Specifically, after an adhesive is applied to the inner circumferential surface 11a of the tire body 1 shown in FIG. 6, the sound-absorbing material 21 is attached to the inner circumferential surface 11a of the tire body 1. The adhesive is, for example, a one-component, room-temperature curing silicone rubber adhesive. In this way, the sound-absorbing material 21 is assembled to the inner circumferential surface 11a of the tire body 1 by a length L1 that is shorter than the circumferential length L0 of the tire body 1. In other words, when the sound-absorbing material 21 having one end 21a and the other end 21b is attached to the inner circumferential surface 11a of the tire body 1, the sound-absorbing material 21 is attached so that a sound-absorbing-material-free region 11b where the sound-absorbing material 21 is not attached is formed between the one end 21a and the other end 21b along the circumferential direction of the tire.

[0040] 5, as shown in Figures 8 to 10, the length L2 in the circumferential direction of the tire of the region 11b where no sound-absorbing material is attached on the inner circumferential surface 11a of the tire main body 1 is measured. Specifically, a distance sensor 200 arranged radially inward of the inner circumferential surface 11a of the tire main body 1 is used to measure the distance H1 to the inner surface 21c of the sound-absorbing material 21 attached to the inner circumferential surface 11a of the tire main body 1 and the distance H0 to the inner circumferential surface 11a of the tire main body 1, thereby measuring the length L2 in the circumferential direction of the tire of the region 11b where no sound-absorbing material is attached based on the results of detecting the positions of one end 21a and the other end 21b of the sound-absorbing material 21 in the circumferential direction.

[0041] Here, distance sensor 200 is disposed inside tire body 1 and measures the distance to inner circumferential surface 11a of tire body 1 or sound-absorbing material 21. Distance H1 to sound-absorbing material 21 (see FIG. 8) is smaller than distance H0 to inner circumferential surface 11a of tire body 1 by the thickness of sound-absorbing material 21.

[0042] 8 and 9, while rotating the tire body 1 relative to the distance sensor 200, the distance sensor 200 is used to measure the distances (H1 and H0) to the inner surface 21c of the sound-absorbing material 21 attached to the inner circumferential surface 11a of the tire body 1 and to the inner circumferential surface 11a of the tire body 1, thereby measuring the length L2 of the sound-absorbing material-free region 11b in the tire circumferential direction based on the rotation angle of the tire body 1 and the measurement results by the distance sensor 200. For example, the tire body 1 is rotated relative to the distance sensor 200 by rotating the tire body 1.

[0043] In addition, by measuring the distance (H0) to the inner circumferential surface 11a of the tire body 1 while rotating the tire body 1 relative to the distance sensor 200, the diameter (radius R1) of the inner circumferential surface 11a of the tire body 1 is obtained, and the length L2 in the circumferential direction of the tire of the non-sound-absorbing material area 11b is measured based on the obtained diameter (radius R1) of the inner circumferential surface 11a of the tire body 1 and the rotation angle θ1 (see Figure 10) of the tire body 1 corresponding to the part of the inner circumferential surface 11a of the tire body 1 where the sound-absorbing material 21 is not attached.

[0044] More specifically, the length L2 of the area 11b on the inner circumferential surface 11a of the tire body 1 where the sound absorbing material is not attached in the circumferential direction of the tire is calculated as L2 = R1 × θ1 (rad) based on the rotation angle θ1 during measurement of the distance H0 to the inner circumferential surface 11a of the tire body 1 and the inner diameter (radius R1) of the tire body 1 based on the distance H1. The inner diameter (radius R1) of the tire body 1 is calculated by adding the distance between the distance sensor 200 and the center of the tire body 1 and the measured distance H0 to the inner circumferential surface 11a.

[0045] 5, the attachment state of the sound-absorbing material 21 is inspected in parallel with the process of measuring the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction. Specifically, as shown in FIGS. 8 and 9, the tire main body 1 is rotated relative to the distance sensor 200, and the attachment state of the sound-absorbing material 21 is inspected by measuring the distance H1 to the inner surface 21c of the sound-absorbing material 21 attached to the inner circumferential surface 11a of the tire main body 1 and the distance H0 to the inner circumferential surface 11a of the tire main body 1. In other words, if the sound-absorbing material 21 is properly attached to the inner circumferential surface 11a of the tire main body 1, the distance to the inner surface 21c of the sound-absorbing material 21 falls within a certain range. On the other hand, if the sound-absorbing material 21 is attached in a wavy manner in the radial direction, the distance to the inner surface 21c of the sound-absorbing material 21 does not fall within the certain range. Therefore, based on the distance measurement results by distance sensor 200, if the distance to inner surface 21c of sound-absorbing material 21 is within a certain range, it is determined that sound-absorbing material 21 is attached properly. If the distance to inner surface 21c of sound-absorbing material 21 is not within the certain range, it is determined that sound-absorbing material 21 is not attached properly. If it is determined that sound-absorbing material 21 is not attached properly, sound-absorbing material 21 is peeled off from inner circumferential surface 11a of tire body 1 and the work of attaching it again is performed.

[0046] 5, based on the length L2 of the non-sound-absorbing material region 11b in the circumferential direction of the tire measured in step S3, the auxiliary sound-absorbing piece 22 is formed having a length L21 that is longer than length L2. Specifically, the auxiliary sound-absorbing piece 22 having the length L21 in the circumferential direction is formed by cutting (cutting out). The auxiliary sound-absorbing piece 22 has a circumferential length L2 that is shorter than the circumferential length L1 of the sound-absorbing material 21. In other words, the auxiliary sound-absorbing piece 22 is formed based on the measured length L2 of the non-sound-absorbing material region 11b in the circumferential direction of the tire.

[0047] Here, the process of forming (cutting out) the sound absorbing auxiliary piece 22 will be described in detail with reference to FIG. 12 (FIGS. 12(A) to 12(D)).

[0048] 12, the auxiliary sound absorbing piece 22 is formed by cutting out an elongated piece of sponge material 20 having a width Wa and a thickness t. An apparatus 300 for cutting out the sponge material 20 includes, for example, a conveyor 301, a support table 302, a conveyor 303, a sensor 304, and a cutter 305.

[0049] Conveyor 301 sends out sponge material 20 towards support stand 302, above which cutter 305 is arranged. Support stand 302 supports sponge material 20 when sponge material 20 is cut by cutter 305. Conveyor 303 carries out sound-absorbing auxiliary pieces 22 formed by cutting.

[0050] The sensor 304 is used to detect the end of the sponge material 20. The sensor 304 is, for example, a laser displacement meter. The cutter 305 cuts the sponge material 20. The cutter 305 is, for example, an ultrasonic cutter that vibrates a blade to cut an object.

[0051] In the process of forming (cutting out) the sound absorbing auxiliary piece 22, as shown in Figure 12(A), the sponge material 20 is moved by a conveyor 301 toward a cutter 305. As shown in Figure 12(B), the end of the sponge material 20 is detected by a sensor 304, and then the amount of feed by the conveyor 301 is controlled.

[0052] 12(C), the sponge material 20 is fed by the conveyor 301 by a distance Lb obtained by adding the desired length L21 and the distance La from the sensor 304 to the cutter 305. The sponge material 20 is then cut by the cutter 305. As a result, an auxiliary sound absorbing piece 22 having the length L21 before assembly is cut out.

[0053] As shown in Figure 12 (D), the sound absorbing auxiliary pieces 22 cut to the length L21 before assembly are carried out by the conveyor 303. The remaining sponge material 20 is returned by the conveyor 301 until the end is detected by the sensor 304. Thereafter, steps (B) to (D) are repeated to sequentially form the sound absorbing auxiliary pieces 22. In addition to the sound absorbing auxiliary pieces 22, the sound absorbing material 21 may also be cut out by the same cutting method as the sound absorbing auxiliary pieces 22 described above.

[0054] 13, the sound-absorbing auxiliary piece 22 is cut so that one end surface 22a and the other end surface 22b in the circumferential direction are parallel to each other. That is, the sound-absorbing auxiliary piece 22 is cut so that one end surface 22a and the other end surface 22b in the horizontal direction are perpendicular to the circumferential direction. This forms the sound-absorbing auxiliary piece 22 having a rectangular parallelepiped shape (a rectangular shape when viewed in the width direction). The sound-absorbing auxiliary piece 22 is made of a sponge material 20 of the same quality as the sound-absorbing material 21 made of the sponge material 20.

[0055] 5, as shown in Fig. 14, adhesive is applied to one circumferential end (one end surface portion 22a) and the other circumferential end (other end surface portion 22b) of the formed sound-absorbing auxiliary piece 22. That is, prior to the step of fitting the sound-absorbing auxiliary piece 22, adhesive is applied to the one end surface portion 22a and the other end surface portion 22b of the sound-absorbing auxiliary piece 22 that abut against the circumferential end faces (one end 21a and the other end 21b) of the sound-absorbing material 21.

[0056] Now, with reference to FIG. 14, the application of adhesive to the one end surface portion 22a and the other end surface portion 22b of the auxiliary sound absorbing piece 22 will be described.

[0057] As shown in Fig. 14, device 300 further includes a sponge fixing unit 306, a sensor 307, and an adhesive applicator 308. Adhesive is applied to one end surface 22a and the other end surface 22b (see Fig. 13) of sound absorbing auxiliary piece 22 downstream in the transport direction of conveyor 303 of device 300. Note that Fig. 14 shows the case where adhesive is applied to one end surface 22a of sound absorbing auxiliary piece 22.

[0058] The sponge fixing portion 306 restricts movement of the sound absorbing auxiliary piece 22 by pressing down on the sound absorbing auxiliary piece 22 from above. The sensor 307 is used to detect the one end surface 22a and the other end surface 22b of the sound absorbing auxiliary piece 22. The sensor 307 is, for example, a laser displacement meter. The adhesive applicator 308 applies adhesive to the one end surface 22a and the other end surface 22b of the sound absorbing auxiliary piece 22. The adhesive applicator 308 is a roller with a rotation axis in the vertical direction. The adhesive applicator 308 moves while rotating from one side to the other in the front and back directions of the page to apply the adhesive.

[0059] More specifically, as shown in FIG. 14(A), the sound absorbing auxiliary piece 22 is moved by the conveyor 303 until one end surface portion 22a of the sound absorbing auxiliary piece 22 is detected by the sensor 307.

[0060] When one end surface 22a of the auxiliary sound absorbing piece 22 is detected by the sensor 307, as shown in Figure 14(B), movement by the conveyor 303 is stopped and the auxiliary sound absorbing piece 22 is fixed by the sponge fixing part 306. Then, adhesive is applied to one end surface 22a of the auxiliary sound absorbing piece 22 by the adhesive applicator 308. Similarly, adhesive is also applied to the other end surface 22b of the auxiliary sound absorbing piece 22.

[0061] In step S6 of FIG. 5, as shown in FIG. 11, a sound-absorbing auxiliary piece 22 having an adhesive applied to one end surface portion 22a and the other end surface portion 22b is fitted between one circumferential end 21a and the other circumferential end 21b of the sound-absorbing material 21. Specifically, the sound-absorbing auxiliary piece 22 having an adhesive applied thereto is fitted between one circumferential end 21a and the other circumferential end 21b of the sound-absorbing material 21 while being compressed in the circumferential direction. In this manner, the sound-absorbing member 2 is assembled to the inner circumferential surface 11a of the tire main body 1. In other words, the sound-absorbing auxiliary piece 22 having a tire circumferential length L21 based on the tire circumferential length L2 of the sound-absorbing material non-attached region 11b where the sound-absorbing material 21 is not attached is placed in the sound-absorbing material non-attached region 11b. The sound-absorbing auxiliary piece 22 is then compressed and fitted into the sound-absorbing material non-attached region 11b.

[0062] (Effects of the embodiment) In this embodiment, the following effects can be obtained.

[0063] In this embodiment, as described above, the auxiliary sound-absorbing piece 22 is disposed with a tire circumferential length L21 based on the tire circumferential length L2 of the non-sound-absorbing-material region 11b where the sound-absorbing material 21 is not attached. This allows the use of a sound-absorbing auxiliary piece 22 with a short length corresponding to the non-sound-absorbing-material region 11b where the sound-absorbing material 21 is not attached. Since the length of the sound-absorbing auxiliary piece 22 is short, errors are less likely to accumulate when measuring the length of the sound-absorbing auxiliary piece 22 compared to when the length of the sound-absorbing auxiliary piece 22 is long, and forming errors (errors during cutting) can be reduced. This allows the sound-absorbing auxiliary piece 22 of the sound-absorbing member 2 to be formed (cut out) with high precision. This allows the sound-absorbing auxiliary piece 22 with a circumferential length formed with high precision to be disposed in the non-sound-absorbing-material region 11b, allowing the sound-absorbing member 2 to be properly and easily assembled to the inner circumferential surface 11a of the tire main body 1. As a result, the sound-absorbing member 2 can be properly and easily assembled to the inner circumferential surface 11a of the tire main body 1 so that the ends of the sound-absorbing member 2 are in close contact with each other.

[0064] Furthermore, as described above, this embodiment includes the steps of measuring the length L2 of the non-sound-absorbing material region 11b in the circumferential direction of the tire, and forming the auxiliary sound-absorbing piece 22 based on the measured length L2 of the non-sound-absorbing material region 11b in the circumferential direction of the tire. This allows a short auxiliary sound-absorbing piece 22 to be formed based on the measurement result (actual measurement value) of the non-sound-absorbing material region 11b to which no sound-absorbing material 21 is attached, thereby making it possible to more accurately form the auxiliary sound-absorbing piece 22 as the sound-absorbing member 2. Furthermore, even if there are individual differences in the inner circumferential length of the tire main body 1, it is possible to accurately form the auxiliary sound-absorbing piece 22 of an appropriate length.

[0065] Furthermore, in this embodiment, as described above, in the step of arranging the sound-absorbing auxiliary piece 22, the sound-absorbing auxiliary piece 22 is compressed and fitted into the sound-absorbing material non-attached region 11b. As a result, the sound-absorbing auxiliary piece 22 is compressed and fitted into the sound-absorbing material non-attached region 11b, which is between one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21 that is attached to the inner circumferential surface 11a of the tire main body 1. Therefore, the sound-absorbing material 21 and the sound-absorbing auxiliary piece 22 can be assembled to the inner circumferential surface 11a of the tire main body 1 so as to be reliably in close contact with each other in the circumferential direction due to the elastic force of the fitted sound-absorbing auxiliary piece 22 that attempts to restore its original shape in the circumferential direction.

[0066] Furthermore, as described above, this embodiment includes a step of forming the length L1 from one end 21a to the other end 21b of the sound-absorbing material 21 to be shorter than the length L0 in the circumferential direction of the tire of the inner circumferential surface 11a of the tire main body 1, prior to the step of attaching the sound-absorbing material 21. This ensures that when the sound-absorbing material 21 formed to be shorter than the circumferential length of the tire is attached to the inner circumferential surface 11a of the tire main body 1, the sound-absorbing material-free region 11b in which the auxiliary sound-absorbing piece 22 is arranged can be provided.

[0067] Furthermore, in this embodiment, as described above, prior to the step of arranging the sound-absorbing auxiliary piece 22, a step of applying adhesive to at least one of the one end surface portion 22a and the other end surface portion 22b of the sound-absorbing auxiliary piece 22 that abut against one end surface and the other end surface in the tire circumferential direction of the sound-absorbing material 21 is provided. This allows the one end surface portion 22a and the other end surface portion 22b in the circumferential direction of the sound-absorbing auxiliary piece 22 to be bonded to the circumferential end surface of the sound-absorbing material 21 with adhesive, with the sound-absorbing auxiliary piece 22 arranged between the one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21. This effectively prevents the sound-absorbing auxiliary piece 22 from falling off the inner circumferential surface 11a of the tire main body 1.

[0068] Furthermore, in this embodiment, as described above, in the step of measuring the length L2 of the non-sound-absorbing material region 11b in the tire circumferential direction, distance sensor 200 arranged radially inward of inner circumferential surface 11a of tire body 1 is used to measure the distance to inner surface 21c of sound-absorbing material 21 attached to inner circumferential surface 11a of tire body 1 and the distance to inner circumferential surface 11a of tire body 1, thereby measuring length L2 of non-sound-absorbing material region 11b in the tire circumferential direction based on the results of detecting the positions of one end 21a and the other end 21b of sound-absorbing material 21 in the tire circumferential direction. This allows measurement by distance sensor 200 to easily and accurately measure length L2 of non-sound-absorbing material region 11b, where no sound-absorbing material 21 is attached to inner circumferential surface 11a of tire body 1, and therefore makes it possible to easily and accurately obtain length L21 of auxiliary sound-absorbing piece 22 arranged in non-sound-absorbing material region 11b.

[0069] Furthermore, in this embodiment, as described above, in the step of measuring the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction, the tire body 1 is rotated relative to the distance sensor 200, and the distance to the inner surface 21c of the sound-absorbing material 21 attached to the inner circumferential surface 11a of the tire body 1 and to the inner circumferential surface 11a of the tire body 1 is measured using the distance sensor 200, thereby measuring the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction based on the relative rotation angle of the tire body 1 and the measurement results by the distance sensor 200. In this way, the length L2 of the non-sound-absorbing-material region 11b on the inner circumferential surface 11a of the tire body 1 can be measured by the distance sensor 200 while the tire body 1 is rotated relative to the distance sensor 200, making it possible to easily measure the entire inner circumferential surface 11a of the tire body 1.

[0070] Furthermore, in this embodiment, as described above, in the step of measuring the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction, the diameter of the inner circumferential surface 11a of the tire body 1 is obtained by measuring the distance to the inner circumferential surface 11a of the tire body 1 while rotating the tire body 1 relative to the distance sensor 200, and the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction is measured based on the obtained diameter of the inner circumferential surface 11a of the tire body 1 and the relative rotation angle of the tire body 1 corresponding to the portion where the sound-absorbing material 21 is not attached to the inner circumferential surface 11a of the tire body 1. As a result, even if the diameter of the tire body 1 is not uniform due to individual differences between tires, the diameter (radius) of the inner circumferential surface 11a of the tire body 1 can be obtained for each tire using the distance sensor 200. Therefore, the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction can be accurately obtained by multiplying the diameter (radius) of the inner circumferential surface 11a of the tire body 1 by the rotation angle.

[0071] Furthermore, in this embodiment, as described above, in the step of measuring length L2 of non-sound-absorbing material region 11b in the tire circumferential direction, distance sensor 200 is used to measure the distance to inner surface 21c of sound-absorbing material 21 while it is attached to inner circumferential surface 11a of tire main body 1, and the distance to inner circumferential surface 11a of tire main body 1, thereby inspecting the attachment state of sound-absorbing material 21 and measuring length L2 of non-sound-absorbing material region 11b in the tire circumferential direction. This makes it possible to inspect the attachment state of sound-absorbing material 21 simultaneously with the measurement to obtain length L2 of non-sound-absorbing material region 11b on inner circumferential surface 11a of tire main body 1 in the tire circumferential direction, thereby reducing the work time. Furthermore, if the inspection reveals that the sound-absorbing material 21 is not properly attached, the work of attaching the sound-absorbing material 21 can be redone before the work of preparing the sound-absorbing auxiliary piece 22 and placing it in the sound-absorbing material non-attached area 11b is performed. As a result, it is possible to prevent a decrease in the efficiency of the work of assembling the sound-absorbing member 2.

[0072] Furthermore, in this embodiment, as described above, in the step of forming the auxiliary sound-absorbing piece 22, the auxiliary sound-absorbing piece 22 is formed to have a trapezoidal shape when viewed in the rotational axis direction of the tire main body 1. This allows the circumferential length of the radially inner surface of the auxiliary sound-absorbing piece 22 to be shortened and the circumferential length of the radially outer surface to be lengthened so that the auxiliary sound-absorbing piece 22 fits the shape of the sound-absorbing material non-attached region 11b, which is the gap between one end 21a and the other end 21b in the circumferential direction of the arc-shaped sound-absorbing material 21. This allows the auxiliary sound-absorbing piece 22 to be fitted between the one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21 so that the degree of compression of the auxiliary sound-absorbing piece 22 in the radial direction is uniform. This also effectively prevents the auxiliary sound-absorbing piece 22 from falling off the inner circumferential surface 11a of the tire main body 1.

[0073] Furthermore, in this embodiment, as described above, in the step of forming the sound-absorbing auxiliary piece 22, the sound-absorbing auxiliary piece 22 is formed from sponge material 20 of the same quality as the sound-absorbing material 21 formed from sponge material 20. This allows the sound-absorbing material 21 and the sound-absorbing auxiliary piece 22 to be formed by cutting the common sponge material 20, thereby efficiently forming the sound-absorbing material 21 and the sound-absorbing auxiliary piece 22. Furthermore, because the sound-absorbing member 2 formed from sponge material 20 of the same quality is provided on the inner circumferential surface 11a of the tire body 1, it is possible to impart uniform sound-absorbing performance around the entire circumference of the tire body 1.

[0074] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0075] For example, in the above embodiment, as shown in FIG. 13 , an example of a configuration in which the sound absorbing auxiliary piece 22 is formed into a rectangular parallelepiped shape so that one circumferential end surface portion 22a and the other circumferential end surface portion 122b are parallel to each other is described. However, the present invention is not limited to this. In the present invention, as shown in a modified example in FIG. 15 , the one circumferential end surface portion 122a and the other circumferential end surface portion 122b of the sound absorbing auxiliary piece 122 do not have to be parallel to each other. In this modified example, the sound absorbing auxiliary piece 122 may be formed into a trapezoid shape in which the outer peripheral sides of the side surfaces 122c and 122d have a length L21 corresponding to the length L2 of the non-sound-absorbing-material region 11b in the tire circumferential direction, and the inner peripheral sides have a length L22 that is shorter than length L21. In other words, in the step of forming the sound absorbing auxiliary piece 122, the sound absorbing auxiliary piece 122 is formed to have a trapezoidal shape when viewed in the direction of the rotational axis of the tire main body 1. This allows the circumferential length of the radially inner surface of the sound absorbing auxiliary piece 122 to be shortened and the circumferential length of the radially outer surface to be lengthened so that the sound absorbing auxiliary piece 122 fits into the shape of the gap between one circumferential end 21a and the other circumferential end 21b of the arc-shaped sound absorbing material 21. As a result, the sound absorbing auxiliary piece 122 can be fitted between one circumferential end 21a and the other circumferential end 21b of the sound absorbing material 21 so that the degree of radial compression of the sound absorbing auxiliary piece 122 is uniform. This effectively prevents the sound absorbing auxiliary piece 122 from falling off the inner circumferential surface 11a of the tire body 1.

[0076] In addition, in the above embodiment, an example of a configuration in which the tire 100 with sound-absorbing material is a pneumatic tire that supports a load by internal air pressure has been shown, but the present invention is not limited to this. In the present invention, the tire with sound-absorbing material may be a tire other than a pneumatic tire. For example, the tire with sound-absorbing material may be a tire that has support parts such as spokes provided inside and supports a load by the support parts.

[0077] In the above embodiment, an example of a configuration was shown in which the length L2 of the non-sound-absorbing material area 11b in the circumferential direction of the tire was measured and obtained, but the present invention is not limited to this. In the present invention, the length of the non-sound-absorbing material area in the circumferential direction of the tire may be obtained based on the design values ​​of the tire and sound-absorbing material dimensions, or the length of the non-sound-absorbing material area in the circumferential direction of the tire may be obtained based on the length of the sound-absorbing material before it is applied.

[0078] Furthermore, in the above embodiment, an example of a configuration was shown in which the auxiliary sound-absorbing piece 22 was compressed and fitted between one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21 attached to the inner circumferential surface 11a of the tire main body 1, but the present invention is not limited to this. In the present invention, the auxiliary sound-absorbing piece may be fitted in an uncompressed state between one end and the other end in the circumferential direction of the sound-absorbing material attached to the inner circumferential surface of the tire main body. In other words, the auxiliary sound-absorbing piece may be formed so that its circumferential length is approximately the same as the length in the circumferential direction of the tire of the area on the inner circumferential surface of the tire main body where no sound-absorbing material is attached.

[0079] In the above embodiment, an ultrasonic cutter is used as the cutter 305 to cut the sponge material 20 to form the sound-absorbing material 21 and the auxiliary sound-absorbing pieces 22, but the present invention is not limited to this. In the present invention, the sponge material may be cut using a cutter other than an ultrasonic cutter to form the sound-absorbing material and the auxiliary sound-absorbing pieces. For example, the sponge material may be cut using a rotary cutter, a water jet cutter, or the like.

[0080] In the above embodiment, the sound-absorbing material 21 and the auxiliary sound-absorbing piece 22 are formed by cutting a long piece of sponge material 20, but the present invention is not limited to this. In the present invention, for example, the sound-absorbing material and the auxiliary sound-absorbing piece may be formed by resin molding, or the sound-absorbing material and the auxiliary sound-absorbing piece of a desired length may be formed by joining together short pieces of sponge material. Furthermore, the sound-absorbing material and the auxiliary sound-absorbing piece may be prepared (formed) by selecting from a plurality of pre-formed sponge materials of different lengths.

[0081] For example, the length of the area around the tire where the sound-absorbing material is not attached can be measured using a gauge or the like, and based on the measurement results, a sponge material of the corresponding length can be selected from a plurality of pre-formed sponge materials of different lengths in stages, to prepare a sound-absorbing auxiliary piece.

[0082] In the above embodiment, an example was shown in which one sound-absorbing material 21 and one auxiliary sound-absorbing piece 22 constitute one circumference of the sound-absorbing member 2 on the inner circumferential surface 11a of the tire main body 1, but the present invention is not limited to this. In the present invention, one circumference of the sound-absorbing member on the inner circumferential surface of the tire main body may also be constituted by a plurality of sound-absorbing materials and a plurality of auxiliary sound-absorbing pieces.

[0083] Furthermore, in the above embodiment, an example of a configuration was shown in which distance sensor 200 was used to measure length L2 of non-sound-absorbing material region 11b on inner circumferential surface 11a of tire main body 1 in the tire circumferential direction, but the present invention is not limited to this. In the present invention, for example, the length of the non-sound-absorbing material region on the inner circumferential surface of the tire main body in the tire circumferential direction may be measured by capturing an image of the inner circumferential surface of the tire main body with a camera. Furthermore, the length of the non-sound-absorbing material region on the inner circumferential surface of the tire main body in the tire circumferential direction may be measured by measuring the shape of the inner circumferential surface of the tire main body using a contact sensor.

[0084] Furthermore, in the above embodiment, an example of a configuration was shown in which the tire body 1 was rotated to measure the length L2 in the circumferential direction of the tire of the non-sound-absorbing material region 11b on the inner circumferential surface 11a of the tire body 1, but the present invention is not limited to this. In the present invention, the length in the circumferential direction of the tire of the non-sound-absorbing material region on the inner circumferential surface of the tire body may be measured by moving a measuring unit such as a distance sensor along the inner circumferential surface of the tire body without rotating the tire body. Furthermore, both the tire body and the distance sensor may be rotated, and the length in the circumferential direction of the tire of the non-sound-absorbing material region on the inner circumferential surface of the tire body may be measured while rotating the tire body relative to the distance sensor.

[0085] In the above embodiment, an example of a configuration was shown in which adhesive was applied to both the one end surface portion 22a and the other end surface portion 22b of the sound-absorbing auxiliary piece 22 that abut against the end surfaces of the one end 21a and the other end 21b in the circumferential direction of the sound-absorbing material 21, but the present invention is not limited to this. In the present invention, adhesive may be applied to only one of the one end surface portion 22a and the other end surface portion 22b of the sound-absorbing auxiliary piece that abut against the end surfaces of the one end and the other end in the circumferential direction of the sound-absorbing material, or adhesive may not be applied to both the one end surface portion 22a and the other end surface portion 22b.

[0086] In the above embodiment, the sound-absorbing material 21 and the auxiliary sound-absorbing pieces 22 are formed from the same sponge material 20, but the present invention is not limited to this. In the present invention, the sound-absorbing material and the auxiliary sound-absorbing pieces may be formed from different materials. Also, the sound-absorbing material and the auxiliary sound-absorbing pieces may be formed from a material other than sponge material that has sound-absorbing properties. For example, the sound-absorbing material and the auxiliary sound-absorbing pieces may be formed from nonwoven fabric.

[0087] Furthermore, in the above embodiment, an example of a configuration was shown in which a band-shaped sound-absorbing member made up of sound-absorbing material 21 and auxiliary sound-absorbing pieces 22 was attached to the inner circumferential surface 11a of tire main body 1, but the present invention is not limited to this. Multiple band-shaped sound-absorbing members arranged in the rotational axis direction (multiple rows) may be attached to the inner circumferential surface of the tire main body, or multiple stacked band-shaped sound-absorbing members arranged in the radial direction may be attached to the inner circumferential surface of the tire main body. [Explanation of symbols]

[0088] 1 Tire body 2. Sound-absorbing materials 11a Inner surface 11b Area without sound-absorbing material 20 Sponge material 21 Sound-absorbing material 21a (One end of sound-absorbing material) 21b (the other end of the sound-absorbing material) 21c (sound-absorbing material) inner surface 22, 122 Sound absorption auxiliary piece 22a (One end surface of the auxiliary sound-absorbing piece) 22b (the other end surface of the sound-absorbing auxiliary piece) 100 Tires with sound-absorbing material 200 distance sensor 305 Cutter 308 Adhesive application section L2 (length in the circumferential direction of the tire of the area without sound-absorbing material) L21 (sound absorbing auxiliary piece) length

Claims

1. a step of attaching a sound-absorbing material having one end and the other end to an inner circumferential surface of a tire body such that a sound-absorbing material-free region where the sound-absorbing material is not attached is formed along the circumferential direction of the tire between the one end and the other end; and a step of arranging a sound-absorbing auxiliary piece having a circumferential length of the tire based on the circumferential length of the tire in the area where the sound-absorbing material is not attached.

2. measuring the length of the region where the sound-absorbing material is not attached in the circumferential direction of the tire; 2. The method for manufacturing a tire with sound-absorbing material according to claim 1, further comprising the step of forming the auxiliary sound-absorbing piece based on the measured length of the non-sound-absorbing material region in the circumferential direction of the tire.

3. The method for manufacturing a tire with sound-absorbing material according to claim 2 , wherein in the step of arranging the auxiliary sound-absorbing piece, the auxiliary sound-absorbing piece is compressed and fitted into the non-sound-absorbing material area.

4. The method for manufacturing a tire with sound-absorbing material according to any one of claims 1 to 3, further comprising, prior to the step of attaching the sound-absorbing material, a step of forming the length from the one end to the other end of the sound-absorbing material to be shorter than the length of the inner surface of the tire main body in the circumferential direction of the tire.

5. 2. A method for manufacturing a tire with sound-absorbing material as described in claim 1, further comprising, prior to the step of arranging the sound-absorbing auxiliary piece, a step of applying adhesive to at least one of one end surface portion and the other end surface portion of the sound-absorbing auxiliary piece that abuts one end surface and the other end surface of the sound-absorbing material in the circumferential direction of the tire.

6. 3. A method for manufacturing a tire with sound-absorbing material as described in claim 2, wherein in the step of measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire, a distance sensor arranged radially inward of the inner circumferential surface of the tire body is used to measure the distance to the inner surface of the sound-absorbing material when attached to the inner circumferential surface of the tire body and the distance to the inner circumferential surface of the tire body, thereby measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire based on the results of detecting the positions of the one end and the other end of the sound-absorbing material in the circumferential direction of the tire.

7. 7. A method for manufacturing a tire with sound-absorbing material according to claim 6, wherein in the step of measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire, the tire body is rotated relative to the distance sensor while the distance sensor is used to measure the distance to the inner surface of the sound-absorbing material attached to the inner surface of the tire body and the inner surface of the tire body, thereby measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire based on the relative rotation angle of the tire body and the measurement result by the distance sensor.

8. 8. A method for manufacturing a tire with sound-absorbing material according to claim 7, wherein in the step of measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire, the tire body is rotated relative to the distance sensor while measuring the distance to the inner circumferential surface of the tire body, thereby obtaining the diameter of the inner circumferential surface of the tire body, and the length of the non-sound-absorbing material area in the circumferential direction of the tire is measured based on the obtained diameter of the inner circumferential surface of the tire body and the relative rotation angle of the tire body corresponding to the portion of the inner circumferential surface of the tire body where the sound-absorbing material is not attached.

9. 7. A method for manufacturing a tire with sound-absorbing material as described in claim 6, wherein in the step of measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire, the distance sensor is used to measure the distance to the inner surface of the sound-absorbing material when it is attached to the inner circumferential surface of the tire body and the distance to the inner circumferential surface of the tire body, thereby inspecting the attachment state of the sound-absorbing material and measuring the length of the non-sound-absorbing material area in the circumferential direction of the tire.

10. The method for manufacturing a tire with sound-absorbing material according to claim 2 , wherein in the step of forming the auxiliary sound-absorbing piece, the auxiliary sound-absorbing piece is formed to have a trapezoidal shape when viewed in the direction of the rotation axis of the tire main body.

11. The method for manufacturing a tire with sound-absorbing material according to claim 2 , wherein in the step of forming the auxiliary sound-absorbing piece, the auxiliary sound-absorbing piece is formed from a sponge material of the same quality as the sound-absorbing material formed from a sponge material.

Images