Sound-absorbing material attaching device, sound-absorbing material attaching method, and method for manufacturing pneumatic tire including the same

Abstract

To make it possible to attach easily a sound absorbing material to an inner surface of a tread part.SOLUTION: A sound absorbing material applying device 1 for applying a sound absorbing material 2 to an inner surface Tb of a tread part T2 of a pneumatic tire T includes: a bead widening tool 3 for widening a space between bead portions T3 in an axial direction of a tire; and an insertion tool 4 for inserting the sound absorbing material 2 into the inner surface Tb from between the bead portions T3 with widened intervals.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a sound-absorbing material application device, a sound-absorbing material application method, and a pneumatic tire manufacturing method including the same. [Background technology]

[0002] Patent Document 1 listed below describes an application device for applying a strip-shaped sponge material to the inner surface of a tire tread. This application device is attached to a support device. The support device inserts and removes the application device through a bead seat hole in the tire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-202765 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in recent years, fuel-efficient tires and high-profile tires for SUVs, which have seen increasing demand, tend to have smaller axial spacing between the bead portions. This makes it difficult to insert the application device into the tire cavity of these types of tires, which in turn makes it difficult to apply the sound-absorbing material to the inner surface of the tread portion.

[0005] The present disclosure has been devised in consideration of the above-mentioned problems, and its main purpose is to provide a sound-absorbing material application device and method for applying sound-absorbing material that can easily apply sound-absorbing material to the inner surface of the tread portion, and a method for manufacturing a pneumatic tire that includes the same. [Means for solving the problem]

[0006] The present disclosure relates to a device for attaching sound-absorbing material to the inner surface of a tread portion of a pneumatic tire having the tread portion and a pair of bead portions, the device including a bead widening tool for widening the axial spacing between the pair of bead portions, and an insertion tool for inserting the sound-absorbing material onto the inner surface from between the pair of bead portions whose spacing has been widened. [Effects of the Invention]

[0007] The sound-absorbing material attachment device, sound-absorbing material attachment method, and pneumatic tire manufacturing method including the same of the present disclosure employ the above-described configuration, thereby making it possible to easily attach sound-absorbing material to the inner surface of the tread portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view showing an embodiment of a sound-absorbing material attachment device according to the present disclosure. [Figure 2] 2 is a side view of the holding portion of the sound-absorbing material attachment device of FIG. 1. [Figure 3] FIG. 10 is a perspective view for explaining an overview of an upper positioning portion. [Figure 4] FIG. [Figure 5] 10 is a flowchart illustrating an example of a processing procedure of an attachment method according to the present disclosure. [Figure 6] FIG. 10 is a front view showing a modified example of a tire using a bead widening tool. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a front view showing a simplified embodiment of a sound-absorbing material attachment device (hereinafter sometimes simply referred to as "device") 1. FIG. 2 is a side view of the device 1. As shown in FIGS. 1 and 2, the device 1 of this embodiment is for attaching sound-absorbing material 2 to a pneumatic tire (hereinafter sometimes simply referred to as "tire") T. The tire T used in the device 1 of the present disclosure is preferably a tire for passenger cars, such as a fuel-efficient tire or a high-profile tire for an SUV. However, the tire T may also be a tire for other passenger cars or a tire for heavy loads.

[0010] The tire T includes, for example, a tread portion T2 and a pair of bead portions T3 (shown in FIG. 6). The tire T also includes, for example, a pair of sidewall portions T4. The tread portion T2 includes an outer surface Ta that comes into contact with the road surface during running, and an inner surface Tb located on the opposite side of the outer surface Ta in the tire radial direction. The inner surface Tb forms the inner cavity of the tire T. Each sidewall portion T4 extends radially inward from both ends of the tread portion T2 in the tire axial direction. The sidewall portion T4 has a tire maximum width position M. Each bead portion T3 is connected to each sidewall portion T4 and extends radially inward in the tire radial direction. Each bead portion T3 has a bead toe Tc located radially inward. The bead toe Tc is an end portion that can come into contact with the rim (not shown).

[0011] In this specification, the tire maximum width position M is the position that protrudes furthest outward in the tire axial direction in the tire cross-sectional contour shape (not shown) in the normal state, excluding letters, patterns, rim protectors, etc. provided on the sidewall portion T4.

[0012] The "normal state" refers to a state in which the tire T is mounted on a normal rim (not shown) and is adjusted to a normal internal pressure with no load.

[0013] The "genuine rim" is a rim that is defined for each tire by the standard system that includes the standard on which tire T is based, such as a "standard rim" for JATMA, a "design rim" for TRA, or a "measuring rim" for ETRTO.

[0014] The "normal internal pressure" is the air pressure determined for each tire by each standard in the standard system including the standard on which tire T is based, and is the "maximum air pressure" in the case of JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the case of TRA, and the "INFLATION PRESSURE" in the case of ETRTO.

[0015] The sound absorbing material 2 is made of, for example, sponge, polyester nonwoven fabric, polystyrene nonwoven fabric, etc. Although not particularly limited, the sound absorbing material 2 is preferably a sponge with a specific gravity of 0.06 to 0.08. In this embodiment, the sound absorbing material 2 is formed as a long strip (shown in FIG. 4). A known adhesive is applied to one surface 2e of the sound absorbing material 2, and the surface is adhered to the inner surface Tb.

[0016] The device 1 of this embodiment includes a bead widening tool 3 and an inserting tool 4. The device 1 further includes, for example, a retaining tool 5. The bead widening tool 3 has a function of widening the axial distance La (shown in FIG. 6) between a pair of bead portions T3. The inserting tool 4 has a function of inserting the sound-absorbing material 2 from between the pair of bead portions T3 where the distance La has been widened onto the inner surface Tb. The retaining tool 5 has a function of holding the tire T rotatably. In this specification, the terms "tire axial direction," "tire radial direction," and "tire circumferential direction" in the device 1 respectively refer to the directions when the tire T is mounted on the device 1.

[0017] The holder 5 of this embodiment includes a frame 7 and a drive unit 8.

[0018] The frame 7 is configured to include a pair of side frames 7L, 7R arranged on both sides of the tire T in the tire axial direction, and a horizontal joint frame piece 7C that joins the side frames 7L, 7R. The joint frame piece 7C is formed, for example, from a plurality of pieces spaced apart in the up-down direction (vertically).

[0019] The drive unit 8 has a function of rotating the tire T around the tire rotation axis. In this embodiment, the drive unit 8 is attached to the frame 7. In this embodiment, the drive unit 8 is configured to include a tire support member 11, a positioning member 12, and a pressing member 13.

[0020] The tire support member 11 holds the tire T in an upright position. The tire support member 11 of this embodiment includes a pair of support rollers 11a, 11b. The pair of support rollers 11a, 11b are arranged parallel to each other with a distance therebetween in the tire circumferential direction. The support rollers 11a, 11b of this embodiment are capable of contacting the outer surface Ta of the tread portion T2, extend along the tire axial direction, and are arranged horizontally. Both ends of the pair of support rollers 11a, 11b are rotatably supported by the frame 7. One of the support rollers 11a is rotationally driven by a motor (not shown) of a well-known structure.

[0021] The positioning member 12 has a function of maintaining the axial position of the tire T placed on the pair of support rollers 11a, 11b. The positioning member 12 can, for example, hold the tire T rotatably while sandwiching it from both sides of the sidewall portion T4. The positioning member 12 includes, for example, an upper positioning portion 12A that positions the upper portion of the tire T in an upright state, and a lower positioning portion 12B that positions the lower portion of the tire T in an upright state.

[0022] The upper positioning portion 12A and the lower positioning portion 12B each include a side support 15 that contacts and holds the sidewall portion T4. The side support 15 is configured to include, for example, a roller 16 and a roller holding portion 17 that rotatably holds the roller 16. The roller 16 in this embodiment is arranged so that its axis 16c faces, for example, the rotation axis of the tire T. The side support 15 is formed in a pair, arranged on both sides in the tire axial direction. The pair of side support members 15 sandwich the tire T from both sides in the tire axial direction.

[0023] FIG. 3 is a perspective view of the upper positioning unit 12A. As shown in FIG. 3, the upper positioning unit 12A includes, for example, a plurality of side supports 15 and a first moving member 18 for moving each side support 15. The upper positioning unit 12A of this embodiment has four side supports 15, with two disposed on each side of the tire T in the axial direction. The two side supports 15 disposed on each side in the axial direction are spaced apart in the tire circumferential direction. The first moving member 18 includes a bifurcated support portion 18a that supports roller holding portions 17 spaced apart in the tire circumferential direction, and a base portion 18b that can move the support portion 18a in the tire axial direction. The support portion 18a holds each side support 15 so that they cannot move relative to each other. The base portion 18b has a well-known structure, for example, a ball screw mechanism or a cylinder mechanism.

[0024] As shown in FIG. 1 , the lower positioning portion 12B includes a side support 15 and a second moving member 19 for moving the side support 15. The lower positioning portion 12B of this embodiment has four side support members 15, with two disposed on each side of the tire T in the axial direction. The two side support members 15 disposed on each side of the tire axial direction are spaced apart in the tire circumferential direction. In this embodiment, the second moving member 19 is connected to each roller holding portion 17. The second moving member 19 can move the roller holding portion 17 in the tire axial direction and in the up-down direction. The second moving member 19 is formed of a well-known structure such as a cylinder mechanism.

[0025] The pressing member 13 of this embodiment includes a pressure roller 20 and a cylinder 21 for moving the pressure roller 20 in the up-down direction. The pressure roller 20 of this embodiment is formed of a pair of rollers 20a (shown in FIG. 3) spaced apart in the tire circumferential direction. Each of the pair of rollers 20a is rotatably held by, for example, the base 18b. The cylinder 21 is supported by, for example, the upper end of the joint frame piece 7C. In this embodiment, the lower end of the rod of the cylinder 21 is connected to the base 18b. The pressing member 13 can move the pressure roller 20 in the up-down direction together with the base 18b by extending the cylinder 21. As a result, the pressing member 13 applies a pressing force to the tire T between the pair of support rollers 11a, 11b and the pressure roller 20, thereby stabilizing the rotation of the tire T by the support roller 11a.

[0026] The bead widening tool 3 includes, for example, a bead widening portion 30 that moves the bead portion T3 axially outward. The bead widening portion 30 includes a first bead widening portion 30A disposed on one side in the tire axial direction and a second bead widening portion 30B (shown in FIG. 6) disposed on the other side in the tire axial direction. For example, the first bead widening portion 30A and the second bead widening portion 30B may be provided one by one, or multiple first bead widening portions 30A and multiple second bead widening portions 30B may be provided at intervals in the tire circumferential direction. In this embodiment, four first bead widening portions 30A and four second bead widening portions 30B are provided.

[0027] Each bead widening portion 30 includes a contact portion 31 and a moving portion (not shown) that can move the contact portion 31 in the tire axial direction and the tire radial direction. The moving portion is configured with a well-known structure such as a ball screw mechanism or a cylinder mechanism.

[0028] The contact portion 31 of this embodiment includes a guide roller portion 35 and a roller holder 36 that rotatably supports the guide roller portion 35. The contact portion 31 is formed, for example, in an L-shape in which the guide roller portion 35 and the roller holder 36 are connected in orthogonal directions.

[0029] The guide roller portion 35 is formed in a cylindrical shape. The guide roller portion 35 of this embodiment can come into contact with the tire T with its longitudinal direction oriented in the tire radial direction. The roller holder 36 includes a base portion 37 and a support shaft 38 extending in a direction perpendicular to the base portion 37. The base portion 37 extends, for example, in the tire axial direction. The support shaft 38 rotatably supports the guide roller portion 35 via, for example, a bearing (not shown). As a result, the guide roller portion 35 comes into contact with the bead portion T3 of the rotating tire T, and thereby rotates in response to the tire T.

[0030] As shown in FIG. 1, the insert 4 of this embodiment includes a wrapper 41 around which the sound-absorbing material 2 is wrapped, and a support 42 that supports the wrapper 41.

[0031] 4 is a front view of the wrapper 41. As shown in FIG. 4, the wrapper 41 includes a frame 43, a holding frame 44, a mount recovery unit 45, and an application roller 46.

[0032] The frame 43 is formed, for example, in the shape of a plate that supports the holding frame 44, the mount recovery unit 45, and the application roller 46. In the present embodiment, a guide roller 47 that guides the sound-absorbing material 2 to the application roller 46 is rotatably disposed on the frame 43.

[0033] The holding frame 44 holds the mount-attached sound-absorbing material 2A wound in a spiral shape. The mount-attached sound-absorbing material 2A is formed by attaching a mount P to one surface 2e of the sound-absorbing material 2. At this time, the mount P is oriented, for example, radially outward of the spiral. The holding frame 44 of this embodiment includes an annular peripheral frame portion 48 that surrounds the outer periphery of the spiral-shaped sound-absorbing material 2, and an outlet 49 that is connected to the peripheral frame portion 48 and through which the sound-absorbing material 2 is unwound and removed.

[0034] The backing paper recovery unit 45 has a peeling roller 50 that peels the backing paper P from the sound-absorbing material 2 taken out from the outlet 49, and a winding roller 51 that winds up and recovers the peeled backing paper P. The sound-absorbing material 2 from which the backing paper P has been peeled is guided by a guide roller 47.

[0035] The application roller 46 presses the sound-absorbing material 2, from which the backing P has been peeled off, against the inner surface Tb to apply it. The application roller 46 is rotatably held at the lower end of the rod of a cylinder 53 fixed to the frame 43 via a roller holder of a well-known structure.

[0036] As shown in FIG. 1 , the support body 42 includes at least a traverse unit 54, a vertically movable unit 55, and a tire size adjustment unit 56, for example. The traverse unit 54 moves the wound body 41 in the tire axial direction and inserts it into the cavity of the tire T through the opening in the bead portion T3. The vertically movable unit 55 moves the wound body 41 inserted into the cavity of the tire T radially outward, downward in this embodiment, so that the sound-absorbing material 2 is attached to the inner surface Tb. The tire size adjustment unit 56 moves the traverse unit 54 and the vertically movable unit 55 up and down to match the size (diameter) of the tire T. This makes it possible to attach the sound-absorbing material 2 to the inner surface Tb of tires T of various sizes.

[0037] Next, a method for attaching the sound-absorbing material 2 using the device 1 of this embodiment will be described. Fig. 5 is a flowchart showing an example of the processing steps of the attachment method of this embodiment. As shown in Fig. 5, the attachment method of this embodiment includes a widening step S2 of widening the axial axial gap La (shown in Fig. 6) between a pair of bead portions T3, and an insertion step S3 of inserting the sound-absorbing material 2 from between the widened bead portions T3 onto the inner surface Tb. The attachment method of this embodiment also includes a fixing step S1 of fixing the tire T.

[0038] First, a fixing step S1 is performed. As shown in Figures 1 and 2, in the fixing step S1, a tire T is inserted into a holder 5. At this time, the inserting tool 4 and the bead widening tool 3 are waiting outside the tire T (not shown).

[0039] In the fixing step S1, the tire T is placed on a pair of support rollers 11a, 11b of the drive unit 8. This places the tire T in an upright state. Next, in the fixing step S1, each side support body 15 of each positioning unit 12A, 12B is moved to a predetermined position on the sidewall portion T4 of the tire T by the first moving member 18 and the second moving member 19. In this embodiment, each side support body 15 is disposed at a position axially outward of the tire maximum width position M.

[0040] In addition, in the fixing step S1, the cylinder 21 of the pressing member 13 is extended downward. As a result, the tire T is sandwiched between the pressure roller 20 and the tire support member 11. In this way, in the fixing step S1, the tire T is positioned in the tire axial direction and the up-down direction.

[0041] Next, the width expanding step S2 is performed. Fig. 6 is a front view showing a modified example of the tire T using the bead widening tool 3. As shown in Fig. 6, in the width expanding step S2 of this embodiment, first, the contact portion 31 of the bead widening tool 3 is positioned axially inside the bead portion T3 of the tire T. Specifically, the moving unit (not shown) is driven to position each guide roller portion 35 in the inner cavity of the tire T.

[0042] Next, in the width increasing step S2, the guide roller portion 35 is brought into contact with the bead portion T3 at a predetermined position and moved axially outward. This increases the axial spacing La of the bead portion T3. The guide roller portion 35 is positioned, for example, so as to come into contact with the bead toe Tc. Furthermore, because the side support 15 of the positioning member 12 is disposed in the above-described position, even when the width increasing step S2 of this embodiment is performed, for example, the inner surface Tb of the tread portion T2 is prevented from protruding radially inward.

[0043] Next, an insertion step S3 is performed. In the insertion step S3 of this embodiment, the wound body 41, which has been waiting on the outside of the tire T, is placed at a predetermined position in the cavity of the tire T by the support body 42. Next, the support roller 11a is rotated, and the tire T is rotated. Next, the sound-absorbing material 2 is attached to the inner surface Tb of the tire T by the wound body 41. In this way, in the device 1 of this embodiment, contact between the insertion tool 4 and the bead portion T3 is suppressed, so the sound-absorbing material 2 can be attached with high precision.

[0044] Although particularly preferred embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the illustrated embodiments and can be modified and implemented in various forms.

[0045] [Note] The present disclosure includes the following aspects.

[0046] [Disclosure 1] A device for attaching a sound-absorbing material to an inner surface of a tread portion of a pneumatic tire having a tread portion and a pair of bead portions, a bead widening tool for widening the axial distance between the pair of bead portions; an inserting tool for inserting the sound absorbing material into the inner surface from between the pair of bead portions whose interval is widened, Sound-absorbing material application device. [Disclosure 2] The sound-absorbing material application device according to Disclosure 1, wherein the bead widening tool includes a plurality of contact portions that can come into contact with each of the pair of bead portions. [Disclosure 3] The sound-absorbing material attachment device according to Disclosure 2, wherein each of the contact portions is rotatable together with the pneumatic tire. [Disclosure 4] A method for attaching a sound-absorbing material to an inner surface of a tread portion of a pneumatic tire having a tread portion and a pair of bead portions, comprising: widening the axial distance between the pair of bead portions; and inserting the sound absorbing material into the inner surface from between the pair of bead portions whose interval has been widened. How to attach sound-absorbing material. [Disclosure 5] The sound-absorbing material attaching method according to Disclosure 4, wherein the step of widening the gap includes moving the contact portions that have been brought into contact with the respective bead portions outward in the tire axial direction. [Disclosure 6] A method for manufacturing a pneumatic tire, including the sound-absorbing material attachment method described in Disclosure 4 or 5. [Explanation of symbols]

[0047] 1. Sound-absorbing material attachment device 2. Sound-absorbing material 3 Bead widening tool 4 Inserts T Pneumatic tire T2 tread area T3 bead part Tb inner surface

Claims

1. A device for attaching a sound-absorbing material to an inner surface of a tread portion of a pneumatic tire having a tread portion and a pair of bead portions, a bead widening tool for widening the axial distance between the pair of bead portions; an inserting tool for inserting the sound absorbing material into the inner surface from between the pair of bead portions whose interval is widened, The tire rotation axis of the tire rotation axis is set to 0.5 mm. the holding tool includes positioning members that hold the pneumatic tire from both sides of a sidewall portion to hold the position of the pneumatic tire in the tire axial direction, the positioning member includes an upper positioning portion that positions an upper portion of the pneumatic tire in an upright state, the upper positioning portion includes side support bodies arranged two on each side of the pneumatic tire in the tire axial direction, and a first moving member for moving each of the side support bodies in the up and down direction, Each of the side support members includes a roller that contacts and holds the sidewall portion, and a roller holding portion that rotatably holds the roller, the first moving member includes a bifurcated support portion that supports the roller holding portions spaced apart in the tire circumferential direction, The support portion holds the two roller holding portions so that they cannot move relative to the support portion. Sound-absorbing material application device.

2. The sound-absorbing material application device according to claim 1 , wherein the bead widening tool includes a plurality of contact portions that can come into contact with the pair of bead portions, respectively.

3. The sound-absorbing material application device according to claim 2 , wherein each of the contact portions is rotatable together with the pneumatic tire.

4. A method for attaching a sound-absorbing material to an inner surface of a tread portion of a pneumatic tire having a tread portion and a pair of bead portions, comprising: widening the axial distance between the pair of bead portions; and inserting the sound absorbing material into the inner surface from between the pair of bead portions whose interval has been widened, The method further includes a fixing step of positioning the pneumatic tire in an upright state in the tire axial direction and the up-down direction before the spreading step, the fixing step includes a step of arranging two roller holding portions that rotatably hold two rollers that contact and hold the sidewall portion of the pneumatic tire, and a bifurcated support portion that fixes the two roller holding portions, on both sides of the pneumatic tire in the tire axial direction, and moving the two roller holding portions to the inside in the tire axial direction. How to attach sound-absorbing material.

5. 5. The sound-absorbing material attaching method according to claim 4, wherein the step of widening the gap comprises moving the contact portions that are in contact with the respective bead portions outward in the tire axial direction.

6. A method for manufacturing a pneumatic tire, comprising the method for attaching a sound-absorbing material according to claim 4 or 5.

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