Sealant application device and manufacturing method of sealant tire

Abstract

To provide a sealant application device which inhibits influence caused by an inner surface shape of a tire to which a sealant material is applied to achieve high uniformity of a thickness of a sealant layer, and to provide a manufacturing method of a sealant tire.SOLUTION: A sealant application device 70 includes: a liner sensor (a measurement unit) 80 which measures an inner surface shape of a tire 1; a control device (a nozzle position setting unit) 81 which sets nozzle position information for determining a position of a nozzle 100 configured to discharge a sealant material 61 relative to an inner surface of the tire 1 based on the inner surface shape; and a robot (a nozzle position control unit) 72 which controls the position of the nozzle 100 based on the nozzle position information.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a sealant application device and a method for manufacturing a sealant tire.

Background Art

[0002] Conventionally, a pneumatic tire having a puncture prevention function in which a hole in the tire formed at the time of puncture is automatically closed by a sealant layer provided on the inner surface of the tire is known. For example, Patent Document 1 describes this type of technology.

[0003] Patent Document 1 relates to a method for manufacturing a pneumatic tire having a sealant layer on the radially inner surface of the inner liner. Patent Document 1 includes a preparation step of preparing a sealant material by mixing raw materials, and a vulcanized tire is rotated around a rotation axis, and while moving the tire in the width direction and the radial direction with respect to a supply port for supplying the sealant material, the sealant material prepared in the preparation step is applied to the radially inner surface of the inner liner in the tire width direction. In the application step, a method for manufacturing a pneumatic tire is described in which the tire is rotated according to a preset rotation speed of the tire for each of a plurality of preset application areas in the tire width direction with respect to the radially inner surface of the tire.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the inner surface shape of a tire may have height differences such as unevenness (displacement in the tire diameter direction). For example, the inner surface of a tire is not a perfect circle and does not necessarily have a smooth surface. The height difference in the inner surface shape of the tire causes displacement in the distance between the nozzle and the inner surface of the tire, resulting in variations in the thickness of the sealant layer.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a sealant application device and a method for manufacturing a sealant tire that can achieve high uniformity in the thickness of the sealant layer.

Means for Solving the Problems

[0007] One aspect of the present invention is a sealant application device for forming a sealant layer on the inner surface of a tire, including a measurement unit for measuring the inner surface shape of the tire, a nozzle position setting unit for setting nozzle position information for determining the position of a nozzle that discharges a sealant material with respect to the inner surface of the tire based on the inner surface shape, and a nozzle position control unit for controlling the position of the nozzle based on the nozzle position information.

[0008] Also, one aspect of the present invention is a method for manufacturing a sealant tire for forming a sealant layer on the inner surface of a tire, including a step of measuring the inner surface shape of the tire, a step of setting nozzle position information for determining the position of a nozzle that discharges a sealant material with respect to the inner surface of the tire based on the inner surface shape, and a step of controlling the position of the nozzle based on the nozzle position information.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a sealant application device and a method for manufacturing a sealant tire that can achieve high uniformity in the thickness of the sealant layer.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a side view of a tire 1 manufactured by the manufacturing method according to the embodiment. G in FIG. 1 indicates a rotation axis that is the rotation center of the tire 1 extending in the front-back direction of the drawing of FIG. 1. In FIG. 1, the tire circumferential direction is indicated by an arrow R. FIG. 2 is a view schematically showing a cross-section in the tire rotation axis direction (tire width direction) of the tire 1. The tire 1 according to the embodiment is a pneumatic tire that is mounted on a rim (not shown) and filled with internal pressure by air or the like in its inner cavity. The tire 1 according to the embodiment is a tire for a passenger car. Note that the manufacturing method of the tire according to the embodiment is also applicable to the manufacturing methods of tires for various vehicles such as light trucks, trucks, and buses.

[0012] The internal structure of the tire 1 will be briefly described with reference to Fig. 2. Fig. 2 shows a cross-section of the tire 1 having a structure symmetric about the direction in which the rotation axis G shown in Fig. 1 extends. The cross-sectional view of Fig. 2 shows the state of the tire 1 in a no-load state where the tire 1 is mounted on a specified rim (not shown) and filled with a specified internal pressure.

[0013] In Fig. 2, reference symbol S1 denotes the tire equatorial plane perpendicular to the rotation axis G. In Fig. 2, the tire rotation axis direction (tire width direction) and the tire radial direction in this specification are indicated by arrows X and Y, respectively. The tire rotation axis direction (the direction of arrow X) is a direction parallel to the rotation axis G and is the left-right direction of the paper surface in the cross-sectional view of Fig. 2. The inner side in the tire rotation axis direction is the direction approaching the tire equatorial plane S1 and is the central side of the paper surface in Fig. 2. The outer side in the tire rotation axis direction is the direction away from the tire equatorial plane S1 and is the left and right sides of the paper surface in Fig. 2. The tire radial direction (the direction of arrow Y) is a direction perpendicular to the rotation axis G and is the up-down direction of the paper surface in Fig. 2. Fig. 1 shows the tire radial direction Y. The outer side in the tire radial direction is the direction away from the rotation axis G and is the upper side of the paper surface in Fig. 2. The inner side in the tire radial direction is the direction approaching the rotation axis G and is the lower side of the paper surface in Fig. 2.

[0014] The tire 1 includes a pair of beads 10 provided on both sides in the tire rotation axis direction, a tread 20 forming a ground contact surface with the road surface, and a pair of sidewalls 30 extending between the pair of beads 10 and the tread 20.

[0015] The pair of beads 10 constitute the inner portion of the tire 1 in the tire radial direction. In order to increase the rigidity of this portion, the bead 10 includes rubber with a high modulus. The bead 10 includes an annular bead core 11 in which a plurality of wound metal bead wires are coated with rubber. The bead core 11 serves to fix the tire 1 to the rim.

[0016] The tread 20 includes a belt 21 and a tread rubber 25 disposed on the outer side in the tire radial direction of the belt 21. The tread rubber 25 has a ground contact surface 25a that contacts the road surface. A plurality of main grooves 26 extending in the circumferential direction are formed in the ground contact surface 25a.

[0017] The belt 21 is a member that reinforces the tread 20. The belt 21 of the embodiment has a two-layer structure including an inner belt 22 and an outer belt 23 disposed on the outer side in the tire radial direction of the inner belt 22. Both the inner belt 22 and the outer belt 23 have a structure in which a plurality of belt cords such as steel cords are covered with rubber. The inner belt 22 is longer in the tire rotation axis direction than the outer belt 23. Therefore, each of both ends 21A of the belt 21 in the tire rotation axis direction is constituted by the end of the inner belt 22 in the tire rotation axis direction. Note that the outer belt 23 may be longer in the tire rotation axis direction than the inner belt 22. Further, the belt 21 may have a single-layer structure or a structure of three or more layers.

[0018] The sidewall 30 includes a sidewall rubber 31 that constitutes the outer sidewall surface of the tire 1. The sidewall rubber 31 bends the most when the tire 1 acts as a cushion and is usually made of a flexible rubber having fatigue resistance.

[0019] Although omitted in FIG. 2, a carcass ply that constitutes a ply serving as the skeleton of the tire 1 is embedded inside the tire 1. This carcass ply is embedded inside the tire 1 in a manner that passes between a pair of bead cores 11 and through a pair of sidewalls 30 and the tread 20. This carcass ply has a configuration in which a plurality of ply cords made of insulating organic fiber cords such as polyester or polyamide are covered with rubber. The belt 21 is disposed on the outer side in the tire radial direction of this carcass ply. Although omitted in FIG. 2, an inner liner as a rubber layer that constitutes the inner wall surface of the tire 1 is provided between a pair of beads on the inner cavity side of the carcass ply. This inner liner is made of an air permeation resistant rubber and prevents the air inside the tire inner cavity from leaking to the outside.

[0020] As shown in FIG. 2, the tire 1 according to the present embodiment further includes a sealant layer 60. The sealant layer 60 is disposed over the entire circumference in the tire circumferential direction in at least the region corresponding to the tread 20 on the tire inner cavity surface formed by the inner liner. The length of the sealant layer 60 in the tire rotational axis direction is larger than the ground contact surface 25a of the tread 20, and both ends 60A of the sealant layer 60 in the tire rotational axis direction are preferably located outside the tire rotational axis direction than both ends of the ground contact surface 25a in the tire rotational axis direction. Further, the length of the sealant layer 60 in the tire rotational axis direction is smaller than the length of the belt 21 in the tire rotational axis direction, and each of both ends 60A of the sealant layer 60 in the tire rotational axis direction is preferably located inside the tire rotational axis direction than both ends 21A of the belt 21 in the tire rotational axis direction. As will be described later, the sealant layer 60 is formed by winding a belt-shaped sealant material 61 along the tire inner surface in the tire circumferential direction. As the sealant material 61, one having adhesiveness is preferably used, and it is attached to the tire inner cavity surface by the adhesiveness. The thickness of the sealant layer 60 is preferably 2 mm or more.

[0021] FIG. 3 is a development view showing a part of the circumferential direction of the tire inner surface to which the sealant material 61 is attached and the sealant layer 60 is formed. In FIG. 3, the tire circumferential direction is indicated by R, and the tire rotational axis direction is indicated by X. As shown in FIG. 3, the sealant layer 60 is formed by one belt-shaped sealant material 61 attached while going around along the tire inner surface in the tire circumferential direction. The sealant layer 60 has a plurality of annular winding portions 62 and a plurality of transition portions 63 formed by the sealant material 61.

[0022] The sealant layer 60 is formed by applying the strip-shaped sealant material 61 along the entire circumference of the application area of the sealant material 61 in the tire axial direction on the inner surface of the tire while circulating it along the tire circumferential direction and shifting the circulation path to one direction (left direction in FIG. 3) in the tire axial direction for each round. As a result, the annular circulation portions 62 formed by the plurality of sealant materials 61 extending in the tire circumferential direction are arranged in parallel in the tire axial direction. Note that the sealant material 61 may be attached to the inner surface of the tire while shifting in the tire axial direction for each round, or may be attached in two or more layers overlapping at the same position in the tire axial direction.

[0023] In FIG. 3, reference numeral 61A indicates the starting end of the sealant material 61, and reference numeral 61B indicates the ending end of the sealant material 61. The sealant material 61 is continuously attached from one end side to the other end side (from the right side to the left side in FIG. 3) in the tire axial direction while circulating as shown by the arrow F from the starting end 61A to the ending end 61B.

[0024] The circulation portion 62 is formed by attaching the sealant material 61 to the inner surface of the tire in parallel with the tire circumferential direction. The plurality of circulation portions 62 are arranged in parallel so as to be adjacent to each other in a closely contacting state in the tire axial direction. The plurality of shifting portions 63 are inclined at a predetermined angle with respect to the tire circumferential direction and are arranged in parallel so as to be adjacent to each other in a closely contacting state.

[0025] The transition portion 63 is provided at a predetermined position in the tire circumferential direction. After the sealant material 61 is attached to the tire inner surface almost one round to form one circumferential portion 62, the transition portion 63 is the portion where the sealant material 61 moves to one side in the tire rotation axis direction (the left side in FIG. 3). After passing through the transition portion 63, the next circumferential portion 62 is adhesively attached adjacent to one side of the already attached circumferential portion 62 in the tire rotation axis direction. The next circumferential portion 62 adjacent to one side in the tire rotation axis direction is repeatedly formed after passing through the transition portion 63, and the sealant layer 60 is formed. In this way, when attaching the sealant material 61 to the tire inner surface, the method of sequentially arranging the circumferential portions 62 parallel to the tire circumferential direction in the tire rotation axis direction while passing through the transition portion 63 is sometimes referred to as step pasting hereinafter.

[0026] As the sealant material 61, for example, an adhesive sealing material in which a plasticizer such as polyisobutylene or polybutene, an adhesion-imparting agent such as a thermoplastic olefin / diolefin copolymer, and a filler such as carbon black or silica are blended in unvulcanized or semi-vulcanized butyl rubber can be used. Note that the sealant material 61 is not limited to this and may be other known sealing materials that have been conventionally used. Also, those having a property of low fluidity and being difficult to flow even during high-speed driving are preferred.

[0027] Next, a sealant application device 70 for manufacturing the tire 1 having the above configuration will be described. The sealant application device 70 forms the above sealant layer 60 on the tire obtained by vulcanizing the green tire which is the prototype of the tire 1 molded to have the above configuration.

[0028] FIG. 4 is a diagram schematically showing the sealant application device 70 to which the manufacturing method according to the embodiment is applied. FIG. 5 is a block diagram showing the functional configuration of the sealant application device 70 to which the manufacturing method according to the embodiment is applied.

[0029] As shown in FIGS. 4 and 5, the sealant application device 70 includes a tire holding device 71, a robot 72, a sealant supply device 73, a line sensor 80, and a control device 81.

[0030] The tire holding device 71 is a tire holding part that holds the tire 1 to which the sealant material 61 is to be applied. The tire holding device 71 of the present embodiment has a gripping part 75 that grips the tire 1. The gripping part 75 is rotationally driven by the tire holding device 71 while gripping the tire 1. As a result, the tire 1 can rotate in the circumferential direction.

[0031] The tire holding device 71 has an encoder 74 for acquiring the rotation angle of the tire 1 gripped by the gripping part 75. The position in the tire circumferential direction can be acquired based on the rotation angle acquired by the encoder 74.

[0032] An example of the gripping part 75 will be described. FIG. 6 is a schematic view of the gripping part 75 that grips the tire 1 as viewed from the side. FIG. 6(a) shows the gripping part 75 before gripping the tire 1, and FIG. 6(b) shows the gripping part 75 after gripping the tire 1. FIG. 7 is a schematic view of the gripping part 75 that grips the tire 1 as viewed from the front. FIG. 7(a) shows the gripping part 75 before gripping the tire 1, and FIG. 7(b) shows the gripping part 75 after gripping the tire 1.

[0033] As shown in FIGS. 6 and 7, the gripping part 75 includes a base part 76 on which the tire 1 is disposed, and an arm part 77 as a tire gripping part that grips the tire 1 disposed on the base part 76.

[0034] The base portion 76 has a surface that faces the tire 1 in the tire rotation axis direction of the tire 1. The arm portion 77 is configured to be movable in the tire radial direction between an open position located on the outer side in the radial direction and separated from the tire 1 and a gripping position located on the inner side in the radial direction and in contact with the tire 1. When the arm portion 77 moves from the open position to the gripping position with respect to the tire 1 disposed on the base portion 76, the tire 1 is held in a state of being pressed from the outer side to the inner side in the tire radial direction. In the present embodiment, a plurality of arm portions 77 are arranged at equal intervals in the tire circumferential direction, and the tire 1 is gripped so as to be sandwiched by the plurality of arm portions 77. Thereby, when the tire 1 is rotationally driven by the tire holding device 71 and further when the sealant material 61 is applied, it is possible to suppress displacement of the position of the gripped tire 1.

[0035] The robot 72 has a nozzle 100 that discharges the sealant material 61 and is a nozzle position control unit that determines a position for discharging the sealant material 61 with respect to the inner surface of the tire 1. Although the orientation of the nozzle 100 is not limited, in the present embodiment, it is position-controlled to be orthogonal to the inner surface of the tire 1 in the coating process. The robot 72 can hold the nozzle 100 at an appropriate position with respect to the tire 1 according to, for example, the type of the tire 1, the thickness of the sealant layer 60, and the like. The sealant supply device 73 supplies the sealant material 61 to the nozzle 100 held by the robot 72.

[0036] The line sensor 80 is a measurement unit that measures the inner surface shape of the tire 1. The line sensor 80 is constituted by, for example, a non-contact optical sensor such as a reflection type laser sensor. Note that the measurement unit is not limited to the line sensor 80, and a camera or the like that can measure the inner surface shape can also be used.

[0037] FIG. 8 is a cross-sectional view in the tire rotation axis direction showing a state in which the inner surface of the tire 1 is measured by the line sensor 80. At the time of measurement, the line sensor 80 is supported at a position where its longitudinal direction is along the tire rotation axis direction and the inner surface of the tire 1 can be measured.

[0038] The configuration and means for supporting the line sensor 80 are not particularly limited. The configuration for supporting the line sensor 80 may be the robot 72, the tire holding device 71, or a dedicated support device for supporting the line sensor 80. Note that the line sensor 80 may be configured to move to the outside of the tire 1 after measurement.

[0039] Due to its wide measurement range in the longitudinal direction, the line sensor 80 can widely measure the displacement in the tire rotation axis direction of the inner surface shape of the tire 1. In the present embodiment, the length L1 in the tire rotation axis direction (the tire width direction of the tire 1) in the measurement range is set to be equal to or greater than the length L2 in the rotation axis direction of the tire 1 in the preset sealant application range.

[0040] Note that FIG. 8 schematically shows the measurement range of the line sensor 80. The measurement range may be covered by a single measurement by the line sensor 80, or may be covered by measuring a plurality of times while shifting the line sensor 80 in the tire rotation axis direction. That is, the measurement range required to acquire the inner surface shape of the tire 1 does not necessarily have to coincide with the measurement range indicated by the performance of the line sensor 80 alone.

[0041] Also, the resolution in the tire rotation axis direction (the tire width direction of the tire 1) of the line sensor 80 is set to be equal to or less than the width of the nozzle opening 101 of the nozzle 100 (see FIG. 10). The tire rotation axis direction of the nozzle opening 101 is a direction parallel to the rotation axis direction of the tire 1.

[0042] The line sensor 80 measures the inner surface to which the sealant material 61 is applied from the inside of the tire 1 with respect to the tire 1 rotated by the tire holding device 71. Therefore, the scanning direction of the line sensor 80 is a direction corresponding to the tire circumferential direction. The line sensor 80 can acquire data for the entire inner circumference of the tire 1, for example, by continuing the measurement while the tire 1 makes one full rotation.

[0043] The inner surface shape measured by the line sensor 80 is stored in the control device 81 in association with the position in the tire circumferential direction. The position in the tire circumferential direction is determined by the rotation angle of the tire 1. The rotation angle can be obtained by an encoder 74 that measures the rotation by the tire holding device 71. Also, the rotation angle may be obtained using the signal of the rotational drive of the tire holding device 71.

[0044] FIG. 9 is a graph showing an example of the inner surface shape of the tire 1 in the circumferential direction at the center in the tire rotation axis direction. In FIG. 9, the horizontal axis is the circumferential rotation angle [deg], and the vertical axis indicates the displacement in the radial direction [mm]. Note that the displacement [mm] may be a measured value or a corrected value obtained by correcting the measured value.

[0045] As shown in FIG. 9, the inner surface of the tire 1 changes in the radial direction in accordance with the change in the rotation angle. For example, since the tire 1 set in the tire holding device 71 is pushed into the radial rotation axis side by the arm portion 77 of the gripping portion 75, the displacement of the gripping portion of the arm portion 77 (movement toward the inner side in the tire radial direction) is large. Also, at the joint portion of the inner liner of the tire 1, although not as much as the gripping portion, a relatively large displacement occurs in the same direction as the gripping portion (the inner side in the tire radial direction).

[0046] The measurement range of the line sensor 80 of the present embodiment is set to include at least the sealant application range in the tire rotation axis direction. Therefore, the circumferential shape information as shown in FIG. 9 is obtained throughout the tire rotation axis direction of the sealant application range. It can also be said that three-dimensional shape information of the sealant application range is obtained based on the measurement result of the line sensor 80.

[0047] The control device 81 executes various controls of the sealant application device 70. The control device 81 is a computer including a processor, a main storage device, an auxiliary storage device, an input / output device, and the like. The control device 81 is connected to the tire holding device 71, the robot 72, the sealant supply device 73, the line sensor 80, etc., and transmits and receives various information. Note that the functions of the control device 81 may be distributed among the tire holding device 71, the robot 72, the sealant supply device 73, and the line sensor 80, and the control of the sealant application device 70 may be performed as a whole by each control device. Thus, the configuration of the control device 81 is not particularly limited.

[0048] The control device 81 of the present embodiment functions as a nozzle position setting unit that executes a process of controlling the position of the nozzle 100 with respect to the tire 1 by the robot 72 based on the inner surface shape of the tire 1 acquired by the line sensor 80.

[0049] The control device 81 creates nozzle information indicating the position of the nozzle 100 in the sealant application process described later. The nozzle position information is information indicating the position of the nozzle 100 with respect to the relatively rotating tire 1. The nozzle position information is created based on the distance based on the preset target sealant thickness and the shape information of the inner surface of the tire 1. The distance based on the target sealant thickness is information that determines the relative positional relationship of the nozzle 100 with respect to the inner surface of the tire 1 set to achieve the target thickness of the sealant layer 60. The distance based on the target sealant thickness may be, for example, the thickness of the target sealant layer 60. Also, the distance based on the target sealant thickness may be set theoretically or empirically based on various factors such as the type of the sealant material 61, the type of the tire 1, and the robot 72 in addition to the thickness of the sealant layer 60.

[0050] In the present embodiment, since the tire 1 rotates with respect to the nozzle 100, the nozzle position information becomes trajectory data indicating the circumferential displacement of the nozzle 100 with respect to the inner surface of the tire 1. The trajectory data can also be said to be information that determines the position of the nozzle 100 in the tire radial direction according to the rotation angle in the circumferential portion 62 excluding the transition portion 63.

[0051] When the application of the sealant material 61 is performed in a plurality of rounds like the step pasting as described above, the position of the nozzle 100 corresponding to the rotation angle is set for each round. The control device 81 creates trajectory data based on, for example, the distance based on the target sealant thickness and the inner surface shape corresponding to the circumferential position (the position in the tire rotation axis direction) among the inner surface shapes acquired by the line sensor 80. Since the resolution of the line sensor 80 is set to be equal to or less than the width of the nozzle opening 101 of the nozzle 100, the trajectory data for each round is accurately created without deviation from the actual inner surface shape in the tire rotation axis direction. When the inner surface shape is displaced in the tire rotation axis direction, at the time of applying the sealant material 61, even if the rotation angle is the same, the position of the nozzle 100 changes according to the inner surface shape in different rounds.

[0052] The position of the nozzle 100 controlled by the robot 72 will be described with reference to FIG. 10. FIG. 10 is a schematic diagram for explaining the position of the nozzle 100 that is displaced according to the inner surface shape. As shown in FIG. 10, the robot 72 controls the position of the nozzle 100 so that the distance d1 between the nozzle opening 101 of the nozzle 100 and the inner surface of the tire 1 is kept constant based on a signal from the control device 81. In the present embodiment, the nozzle 100 is fixed to the arm 72A of the robot 72. Note that the nozzle 100 is fixed to the arm 72A via the fixing portion 72B. A flow passage 73A for supplying the sealant material 61 from the sealant supply device 73 is connected to the nozzle 100. The flow passage 73A may be configured to be bendable.

[0053] FIG. 10(a) shows the position of the nozzle 100 for applying the sealant material 61 to a portion where the displacement of the inner surface shape of the tire 1 is 0 or relatively small, and FIG. 10(b) shows the position of the nozzle 100 for applying the sealant material 61 to a portion where the displacement of the inner surface shape of the tire 1 is large. The portions of the tire 1 shown in FIGS. 10(a) and 10(b) are different portions in the tire circumferential direction or the tire rotation axis direction. In this example, the position of the nozzle 100 in FIG. 10(b) is at a higher position (a position closer to the inner side in the tire diameter direction) than the position of the nozzle 100 in FIG. 10(a).

[0054] FIG. 10(c) shows the position of the nozzle 100 for applying the sealant material 61 to the R portions on both end sides in the tire rotation axis direction of the tire 1, which is a portion different from FIGS. 10(a) and 10(b) in the tire rotation axis direction. In this example, the position of the nozzle 100 in FIG. 10(c) is at a higher position than FIGS. 10(a) and 10(b) in order to conform to the inner surface shape of the R portion.

[0055] As shown in FIGS. 10(a) to 10(c), even if the inner surface shape of the tire 1 is different in the tire circumferential direction or the tire rotation axis direction, since the position of the nozzle 100 is controlled based on the actually measured inner surface shape, the radial distance d1 between the nozzle opening 101 of the nozzle 100 and the tire 1 is maintained constant.

[0056] Further, the control device 81 sets an application start position (operation reference position) at which the discharge of the sealant material 61 is started by the nozzle 100 according to the rotation angle (measurement reference position) at the start of measurement by the line sensor 80. The control device 81 uses the rotation angle detected by the encoder 74 of the tire holding device 71 to control the robot 72 and the tire holding device 71 so that the position in the tire circumferential direction in the track data corresponds to the position in the tire circumferential direction in the application process.

[0057] In the present embodiment, the position of the nozzle 100 with respect to the tire 1 is controlled based on the inner surface shape of the tire 1 acquired by the line sensor 80, so that even on the inner surface where circumferential displacement as shown in FIG. 9 occurs, it is possible to make the thickness of the sealant layer 60 uniform. The configuration of the present embodiment is a tire holding device 71 (tire holding portion) having a plurality of arm portions 77 (tire gripping portions) configured to be movable in the tire radial direction between an open position located on the outer side in the radial direction and separated from the tire 1 and a gripping position located on the inner side in the radial direction and in contact with the tire 1. In a sealant application device 70 including the tire holding device 71 that gives a plurality of local displacements in the tire radial direction to the inner surface of the tire 1 by the plurality of arm portions 77, even such a sealant application device 70 can form a sealant layer 60 having high uniformity on the inner surface of the tire 1.

[0058] Next, the flow of the method for manufacturing a sealant tire will be described. FIG. 11 is a flowchart showing the flow of the manufacturing process of the sealant tire.

[0059] In step S11, a tire holding step of holding the tire 1 by the gripping portion 75 of the tire holding device 71 is executed. In the tire holding step, the tire 1 is attached to the tire holding device 71 in a state where the tire 1 and the nozzle 100 can rotate relative to each other in the tire circumferential direction. In the present embodiment, the tire 1 is placed on the base portion 76 of the gripping portion 75 of the tire holding device 71 and fixed by the arm portion 77, whereby the tire 1 is attached to the tire holding device 71. In the present embodiment, the tire holding device 71 rotates the tire 1, so that the tire 1 rotates relative to the nozzle 100.

[0060] In step S12, a tire measurement process is executed in which the inner surface of the tire 1 is measured by the line sensor 80. In the tire measurement process, while the line sensor 80 is arranged at a position where the inner surface of the tire 1 can be measured, measurement by the line sensor 80 is performed while the tire 1 is rotated by the tire holding device 71. By rotating the tire 1 at least one full turn, the inner surface shape of the entire circumference of the tire 1 is measured. When the width in the tire rotation axis direction within the measurement range of the line sensor 80 is narrower than the sealant application range, the inner surface shape of the entire circumference of the tire 1 is measured by rotating it a plurality of turns while moving the line sensor 80 in the tire rotation axis direction. The inner surface shape starts measurement from the measurement reference position and is stored in association with the rotation angle of the tire 1.

[0061] In step S13, a process of creating trajectory data (nozzle position information) based on the inner surface shape measured in step S12 is executed by the control device 81. The control device 81 creates trajectory data by offsetting the distance based on the target sealant thickness with respect to the inner surface shape (position in the tire diameter direction) associated with the rotation angle to the tire rotation axis side in the tire diameter direction.

[0062] In step S14, a process of associating the measurement reference position in the tire circumferential direction with the application start position at which the sealant material 61 is started to be applied by the nozzle 100 in the tire 1 is executed by the control device 81. The control device 81 controls the tire holding device 71 and the robot 72 to move the nozzle 100 to the application start position (operation start position).

[0063] In step S15, the control device 81 applies the sealant material 61 while controlling the position of the nozzle 100 based on the trajectory data while rotating the tire 1. The control device 81 displaces the position of the nozzle 100 according to the rotation angle based on the trajectory data by controlling the tire holding device 71 and the robot 72.

[0064] As described with reference to FIG. 3, while continuously discharging the sealant material 61 from the nozzle 100 and continuously rotating the tire 1 around the axis, the tire 1 is rotated approximately one full turn in a state where the movement in the tire rotation axis direction is stopped, thereby applying one circumferential portion 62. The position of the nozzle 100 is stationary in the tire rotation axis direction at the circumferential portion 62, but is displaced in the tire radial direction based on the track data in the radial direction. Next, when the nozzle 100 is moved to one side in the tire rotation axis direction by the width of the sealant material 61, a transition portion 63 is applied therebetween. In the transition portion 63, depending on the inner surface shape, the positions in both the tire radial direction and the tire rotation axis direction may be displaced.

[0065] Next, the movement in the tire rotation axis direction is stopped, and the circumferential portion 62 is applied while displacing the position of the nozzle 100 based on the track data adjacent to the previously applied circumferential portion 62. By repeating the above operations, the sealant material 61 can be step - pasted in the formation region of the sealant layer 60. When the sealant material 61 is applied and pasted over the entire formation region of the sealant layer 60, the discharge of the sealant material 61 from the nozzle 100 is stopped.

[0066] According to the above - described embodiment, the following effects can be obtained.

[0067] (1) The sealant application device 70 according to the embodiment includes a line sensor (measurement unit) 80 that measures the inner surface shape of the tire 1, a control device (nozzle position setting unit) 81 that sets nozzle position information for determining the position of the nozzle 100 that discharges the sealant material 61 with respect to the inner surface of the tire 1 based on the inner surface shape, and a robot (nozzle position control unit) 72 that controls the position of the nozzle 100 based on the nozzle position information.

[0068] As a result, the sealant material 61 is applied while the nozzle 100 is displaced according to the actually measured inner surface shape of the tire 1. Therefore, thickness variations caused by the R portion and unevenness on the inner surface of the tire 1 are suppressed, and a sealant layer 60 having high uniformity can be formed on the inner surface of the tire 1. That is, the relative positional relationship between the inner surface of the tire 1 and the nozzle 100 (the distance between the tip of the nozzle 100 and the inner surface of the tire 1) set initially remains constant regardless of the inner surface shape of the tire. Generally, when the sealant layer 60 is disposed on the inner surface of the tire 1, the durability against heat and the like during high-speed driving decreases. It has been found that this durability is affected by the thickness of the sealant layer 60, and when the thickness of the sealant layer 60 is increased, the durability decreases. In this regard, with the configuration of the present embodiment, the sealant layer 60 can be accurately and uniformly applied over the application range with a thickness capable of holding air. Therefore, the thickness can be made as thin as possible while ensuring air retention, and both the durability and air retention of the tire 1 can be realized.

[0069] Generally, in the inner surface shape of a tire, height differences such as unevenness (displacement in the position in the tire diameter direction) may occur. For example, the inner surface of the tire is not a perfect circle and does not necessarily have a smooth surface. Also, R portions are formed in the inner surface shape at both ends in the tire rotation axis direction on the inner surface of the tire, and unevenness such as bladder marks may occur during the manufacturing process of the tire such as bladder marks. Even for such a tire, with the sealant application device 70 of the present embodiment, a sealant layer 60 having high uniformity can be formed on the inner surface of the tire 1.

[0070] Further, the configuration of the present embodiment is also effective even when the tire is deformed radially inward by the pressing of the device holding the tire in the process of applying the sealant material, and the shape of the inner surface of the tire is deformed. More specifically, the configuration of the present embodiment is a tire holding device 71 (tire holding portion) having a plurality of arm portions 77 (tire gripping portions) configured to be movable in the tire radial direction between an open position located radially outside and separated from the tire 1 and a gripping position located radially inside and in contact with the tire 1, and the tire holding device 71 that gives a plurality of local displacements in the tire radial direction to the inner surface of the tire 1 by the plurality of arm portions 77. Even in the sealant application device 70 including this, such a sealant application device 70 can form a sealant layer 60 having high uniformity on the inner surface of the tire 1.

[0071] (2) The control device 81 according to the embodiment of (1) creates the orbital data of the nozzle 100 indicating the circumferential displacement of the nozzle 100 with respect to the inner surface of the tire 1 as nozzle position information.

[0072] Thereby, the entire area of the sealant layer 60 can be formed more uniformly corresponding to the circumferential displacement by the orbital data.

[0073] (3) The sealant application device 70 according to the embodiment of (1) or (2) further includes a tire holding device (tire holding portion) 71 that holds the tire 1 so that the tire 1 and the nozzle 100 can rotate relative to each other in the tire circumferential direction. The line sensor 80 measures the inner surface shape in the circumferential direction by relatively rotating the tire 1 by the tire holding device 71. The control device 81 creates nozzle position information by associating the rotation angle at the time of measurement by the line sensor 80 with the inner surface shape in the circumferential direction, and the robot 72 controls the position of the nozzle 100 based on the rotation angle at the time of measurement and the nozzle position information.

[0074] Thereby, since the measured inner surface shape is associated with the rotation angle, the creation process of the orbital data (nozzle position information) for determining the position of the nozzle 100 in the application process can be executed without performing complicated processing.

[0075] (4) The line sensor 80 according to the embodiments of (1) to (3) is arranged along the tire rotation axis direction.

[0076] Thereby, the inner surface shape in the tire rotation axis direction (the tire rotation axis direction of the tire 1) in the application range of the sealant material 61 can be efficiently and widely measured by the line sensor 80.

[0077] (5) The length in the tire rotation axis direction in the measurement range of the line sensor 80 according to the embodiments of (1) to (4) is set so as to include the entire length in the tire rotation axis direction of the sealant application range.

[0078] Thereby, the entire sealant application range including the R portions at both ends of the inner surface in the tire rotation axis direction of the tire 1 where the distance between the nozzle 100 and the inner surface of the tire 1 is displaced can be reliably measured. Since the track data covering the entire sealant application range can be generated, the uniformity in the tire rotation axis direction can be further improved.

[0079] (6) The resolution in the tire rotation axis direction of the line sensor 80 according to the embodiments of (1) to (5) is equal to or less than the width of the opening 101 of the nozzle 100.

[0080] According to the configuration of the present embodiment, since the inner surface shape in the tire rotation axis direction is measured by the line sensor 80 having a resolution equal to or less than the width of the opening 101 that determines the width of the circumferential portion 62 of the sealant layer 60, a sealant layer 60 having high accuracy and high uniformity can be formed on the inner surface of the tire 1 even in the tire rotation axis direction.

[0081] (7) The line sensor 80 as the measurement unit according to the embodiments of (1) to (6) measures data for the entire inner circumference of the tire 1.

[0082] Thereby, the inner surface shape of the entire inner circumference of the tire 1 can be reflected in the track data (nozzle position information), and a sealant layer 60 having higher uniformity can be formed over the entire circumference of the tire 1.

[0083] (8) The manufacturing method of the sealant tire according to the embodiment includes a step of measuring the inner surface shape of the tire 1, a step of setting nozzle position information for determining the position of the nozzle 100 that discharges the sealant material 61 with respect to the inner surface of the tire 1 based on the inner surface shape, and a step of controlling the position of the nozzle 100 based on the nozzle position information.

[0084] Also, according to the manufacturing method of the sealant tire according to the embodiment, since the sealant material 61 is applied while the nozzle 100 is displaced according to the actually measured inner surface shape of the tire 1, variations in thickness due to the R portion and unevenness on the inner surface of the tire 1 are suppressed, and a sealant layer 60 having high uniformity can be formed on the inner surface of the tire 1. That is, the relative positional relationship between the inner surface of the tire 1 and the nozzle 100 (the distance between the tip of the nozzle 100 and the inner surface of the tire 1) set initially is constant regardless of the inner surface shape of the tire.

[0085] Although the embodiments have been described above, the present invention is not limited to the above embodiments, and modifications, improvements, etc. can be made within the scope that can achieve the object of the present invention, and they are included in the scope of the present invention.

[0086] For example, in the above embodiment, an example of applying the sealant material 61 by step-by-step pasting has been described, but the application method of the sealant material 61 is not limited to the configuration of the embodiment. For example, the present invention can also be applied to a configuration in which the sealant material 61 is applied in a spiral shape in the application step. Also, in the above embodiment, the configuration is such that the position of the nozzle 100 is changed while the tire 1 is rotated, but the present invention can also be applied to a configuration in which the nozzle 100 is moved with respect to the tire 1.

Explanation of reference numerals

[0087] 1 Tire 60 Sealant layer 61 Sealant material 70 Sealant application device 71 Tire holding device (tire holding portion) 72 Robot (nozzle position control portion) 73 Sealant supply device 80 Line sensor (measurement unit) 81 Control device (nozzle position setting unit) 100 Nozzle

Claims

1. A sealant application device for forming a sealant layer on an inner surface of a tire, A measurement unit that measures an inner surface shape of the tire; a nozzle position setting unit that sets nozzle position information that determines a position of a nozzle that ejects a sealant material with respect to an inner surface of the tire based on a shape of the inner surface; a nozzle position control unit that controls the position of the nozzle based on the nozzle position information; A sealant application device comprising:

2. The nozzle position setting unit is creating, as the nozzle position information, trajectory data of the nozzle indicating a circumferential displacement of the nozzle with respect to the inner surface of the tire; The sealant applicator of claim 1 .

3. a tire holding portion that holds the tire so that the tire and the nozzle are relatively rotatable in a circumferential direction of the tire; the measurement unit measures the inner surface shape in a circumferential direction by relatively rotating the tire using the tire holding unit, the nozzle position setting unit creates the nozzle position information by correlating a rotation angle at the time of measurement by the measurement unit with the inner surface shape in a circumferential direction; the nozzle position control unit controls the position of the nozzle based on the rotation angle at the time of the measurement and the nozzle position information. The sealant applicator according to claim 1 or 2.

4. The measurement unit is a line sensor arranged along the tire rotation axis direction. The sealant applicator according to claim 1 or 2.

5. The length of the measurement range of the measurement unit in the tire rotational axis direction is set to include the entire length of the sealant application range in the tire rotational axis direction. The sealant applicator according to claim 1 or 2.

6. The resolution of the measurement unit in the tire rotation axis direction is equal to or less than the width of the opening of the nozzle. The sealant applicator according to claim 1 or 2.

7. The measurement unit measures data for the entire circumference of the inner surface of the tire. The sealant applicator according to claim 1 or 2.

8. A method for manufacturing a sealant tire by forming a sealant layer on an inner surface of a tire, comprising the steps of: measuring an inner surface shape of the tire; setting nozzle position information for determining a position of a nozzle for discharging a sealant material with respect to an inner surface of the tire based on the shape of the inner surface; controlling the position of the nozzle based on the nozzle position information; A method for producing a sealant tire comprising the steps of:

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