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 nozzle 100 configured to discharge a sealant material 61; a displacement gauge 90 which measures a change of a distance to an inner surface of a tire 1 to which the sealant material 61 is applied; and a robot (a nozzle position control unit) 72 which controls a position of the nozzle 100 based on a measurement result of the displacement gauge 90.SELECTED DRAWING: Figure 17

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 a 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 inner surface in the tire radial direction of an inner liner. Patent Document 1 includes a preparation step of preparing a sealant material by mixing raw materials, and a coating step of rotating a vulcanized tire around a rotation axis and applying the sealant material prepared in the preparation step to the inner surface in the tire radial direction of the inner liner while moving the tire in the width direction and the radial direction with respect to a supply port for supplying the sealant material. In the coating step, a method for manufacturing a pneumatic tire is described in which the tire is rotated according to a preset rotational speed of the tire for each of a plurality of preset coating areas in the width direction of the tire with respect to the inner surface in the tire radial direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, 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 nozzle for discharging a sealant material, a displacement meter for measuring displacement in the distance to the inner surface of the tire on which the sealant material is to be applied, and a nozzle position control unit for controlling the position of the nozzle based on the measurement result of the displacement meter.

[0008] Another 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 displacement in the distance to the inner surface of the tire on which the sealant material is to be applied by a displacement meter, a step of controlling the position of the nozzle based on the measurement result of the displacement meter, and a step of discharging the sealant material by the nozzle.

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

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Figure 9

Figure 10

Figure 11

Figure 12

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Figure 14

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Figure 17

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, which is the center of rotation of the tire 1 extending in the front-back direction of the plane of the drawing of FIG. 1. In FIG. 1, the tire circumferential direction is indicated by an arrow R. FIG. 2 is a diagram schematically showing a cross section of the tire 1 in the tire rotation axis direction (tire width direction). 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 passenger car tire. 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] With reference to FIG. 2, the internal structure of the tire 1 will be briefly described. FIG. 2 shows a cross section of the tire 1 having a symmetric structure in 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 in which the tire 1 is mounted on a prescribed rim (not shown) and filled with a prescribed internal pressure.

[0013] In FIG. 2, reference numeral S1 denotes a tire equatorial plane perpendicular to the rotation axis G. In FIG. 2, the tire rotation axis direction (tire width direction) and the tire diameter direction in this specification are indicated by arrows X and Y, respectively. The tire rotation axis direction (arrow X direction) is a direction parallel to the rotation axis G and is the left-right direction of the plane of the cross-sectional view of FIG. 2. The inside in the tire rotation axis direction is a direction approaching the tire equatorial plane S1 and is the center side of the plane of the drawing in FIG. 2. The outside in the tire rotation axis direction is a direction away from the tire equatorial plane S1 and is the left side and the right side of the plane of the drawing in FIG. 2. The tire diameter direction (arrow Y direction) is a direction perpendicular to the rotation axis G and is the up-down direction of the plane of the drawing in FIG. 2. FIG. 1 shows the tire diameter direction Y. The outside in the tire diameter direction is a direction away from the rotation axis G and is the upper side of the plane of the drawing in FIG. 2. The inside in the tire diameter direction is a direction approaching the rotation axis G and is the lower side of the plane of the drawing 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 diameter 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 of the belt 21 in the tire diameter direction. 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 of the inner belt 22 in the tire diameter direction. 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 larger in length 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 larger in length 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, carcass plies that form the framework of the tire 1 are embedded inside the tire 1. The carcass plies are embedded inside the tire 1 in a manner that passes between a pair of bead cores 11 through a pair of sidewalls 30 and a tread 20. The carcass plies have a configuration in which a plurality of ply cords made of insulating organic fiber cords such as polyester or polyamide are coated with rubber. The belt 21 is disposed on the outer side in the tire radial direction of the carcass plies. Although omitted in Fig. 2, an inner liner as a rubber layer that constitutes the inner wall surface of the tire 1 is provided across a pair of beads on the inner cavity side of the carcass plies. The inner liner is made of 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 a region corresponding to the tread 20 of the tire inner cavity surface formed by the inner liner. The length of the sealant layer 60 in the tire rotation 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 rotation axis direction are preferably located outside the tire rotation axis direction than both ends of the ground contact surface 25a in the tire rotation axis direction. Also, the length of the sealant layer 60 in the tire rotation axis direction is smaller than the length of the belt 21 in the tire rotation axis direction, and each of both ends 60A of the sealant layer 60 in the tire rotation axis direction is preferably located inside the tire rotation axis direction than both ends 21A of the belt 21 in the tire rotation axis direction. As will be described later, the sealant layer 60 is formed by winding a strip-shaped sealant material 61 along the tire circumferential direction on the tire inner surface. 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] Figure 3 is a developed view showing a part of the circumferential direction of the inner surface of the tire where the sealant material 61 is attached to form the sealant layer 60. In Figure 3, the tire circumferential direction is indicated by R, and the tire rotation axis direction is indicated by X. As shown in Figure 3, the sealant layer 60 is formed by one strip-shaped sealant material 61 that is wound along the tire circumferential direction while being attached to the inner surface of the tire. 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 tire circumferential direction while winding it around the entire circumference of the application area of the sealant material 61 in the tire rotation axis direction on the inner surface of the tire, and shifting the winding path one by one in one direction (left direction in Figure 3) in the tire rotation axis direction. Thereby, the annular winding portions 62 formed by a plurality of sealant materials 61 extending in the tire circumferential direction are arranged in parallel in the tire rotation axis direction. Note that the sealant material 61 may be attached to the inner surface of the tire while shifting in the tire rotation axis direction for each turn, or may be attached in two or more layers overlapping at the same position in the tire rotation axis direction.

[0023] In Figure 3, reference numeral 61A indicates the start end of winding of the sealant material 61, and reference numeral 61B indicates the end end of winding 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 Figure 3) in the tire rotation axis direction while winding as shown by the arrow F from the start end 61A to the end end 61B.

[0024] The winding portion 62 is formed by attaching the sealant material 61 to the inner surface of the tire parallel to the tire circumferential direction. The plurality of winding portions 62 are arranged in parallel so as to be adjacent to each other in a closely contacting state in the tire rotation axis direction. The plurality of transition 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 in the tire rotation axis direction of the already attached circumferential portion 62. 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 attachment hereinafter.

[0026] As the sealant material 61, for example, an adhesive sealing material in which a plasticizer such as polyisobutylene or polybutene, a tackifier 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 characteristics of low fluidity and being difficult to flow even during high-speed driving are preferred.

[0027] Next, a sealant coating device 70 for manufacturing the tire 1 having the above configuration will be described. The sealant coating 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 a sealant coating device 70 to which the manufacturing method according to the first embodiment is applied. FIG. 5 is a block diagram showing the functional configuration of the sealant coating device 70 to which the manufacturing method according to the first 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 displacement meter 90, 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 facing 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 between 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 the position of the gripped tire 1 from shifting.

[0035] The robot 72 has a nozzle 100 that discharges the sealant material 61 and is a nozzle position control unit that determines the 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 displacement meter 90 measures the distance to the inner surface of the tire 1 on which the sealant material 61 is applied. The displacement meter 90 is constituted by, for example, a non-contact optical sensor such as a reflective laser sensor.

[0037] FIG. 8 is a cross-sectional view in the tire rotation axis direction showing a state where the inner surface of the tire 1 is measured by the displacement gauge 90. The displacement gauge 90 is supported so that the relative position in the radial direction of the tire 1 is fixed in the positional relationship with the nozzle 100. In the present embodiment, the nozzle 100 and the displacement gauge 90 are 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. The displacement gauge 90 of the first embodiment is arranged to be orthogonal to the inner surface of the tire 1 in the same manner as the nozzle 100. 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. A cable 90A for communicating between the displacement gauge 90 and the control device 81 is connected to the displacement gauge 90.

[0038] FIG. 9 is a graph showing an example of the inner surface shape of the tire 1 in the tire circumferential direction at the center in the tire rotation axis direction. In FIG. 9, the horizontal axis represents the rotation angle [deg] in the circumferential direction, and the vertical axis represents the displacement [mm] in the radial direction. The displacement [mm] may be an actual measured value or a corrected value obtained by correcting the actual measured value.

[0039] 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 rotation axis side in the radial direction by the arm portion 77 of the gripping portion 75, the displacement (movement toward the inner side in the tire radial direction) of the gripping portion of the arm portion 77 becomes large. Also, at the joint portion of the inner liner of the tire 1, although not as large as the gripping portion, a relatively large displacement occurs in the same direction (the inner side in the tire radial direction) as the gripping portion.

[0040] In this embodiment, based on the measurement result of the displacement gauge 90, the position of the nozzle 100 is controlled, so that even on the inner surface where circumferential displacement as shown in FIG. 9 occurs, the thickness of the sealant layer 60 can be made uniform. The configuration of this embodiment is a tire holding device 71 (tire holding part) having a plurality of arm parts 77 (tire gripping parts) 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. The tire holding device 71 gives a plurality of local displacements in the tire radial direction to the inner surface of the tire 1 by the plurality of arm parts 77. The tire holding device 71 is particularly useful in the sealant application device 70, and even such a sealant application device 70 can form a sealant layer 60 having high uniformity on the inner surface of the tire 1.

[0041] 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 displacement gauge 90, 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 displacement gauge 90, and the control of the sealant application device 70 may be performed as a whole. Thus, the configuration of the control device 81 is not particularly limited.

[0042] The control device 81 of this 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 displacement of the distance to the inner surface of the tire 1 acquired by the displacement gauge 90.

[0043] 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 inner surface of the tire 1. The nozzle position information is created based on the distance based on the preset target sealant thickness and the displacement information acquired by the displacement meter 90. 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. Further, the distance based on the target sealant thickness may be set theoretically or empirically based on various elements such as the type of the sealant material 61, the type of the tire 1, the robot 72, etc. in addition to the thickness of the sealant layer 60.

[0044] In the first embodiment, since the relative position in the radial direction between the nozzle 100 and the displacement meter 90 is fixed, the distance from the nozzle 100 to the inner surface of the tire 1 can be calculated by reflecting the relative position in the measurement result of the displacement meter 90. For example, the distance from the nozzle 100 to the inner surface of the tire 1 is calculated by subtracting the relative distance in the radial direction between the reference position of the nozzle 100 and the reference position of the displacement meter 90 from the measurement result.

[0045] 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 displaces 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 maintained constant based on a signal from the control device 81. Further, since the nozzle 100 and the displacement meter 90 are fixed, the positions of the nozzle 100 and the displacement meter 90 may be controlled so that the distance d0 between the displacement meter 90 and the inner surface of the tire 1 as the measurement result of the displacement meter 90 is maintained constant.

[0046] 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 radial direction) than the position of the nozzle 100 in FIG. 10(a).

[0047] As shown in FIGS. 10(a) and 10(b), even if the inner surface shape of the tire 1 is different in the tire circumferential direction or the tire rotation axis direction, the position of the nozzle 100 is controlled based on the displacement of the actually measured distance to the inner surface, so that the radial distance d1 between the nozzle opening 101 of the nozzle 100 and the tire 1 is maintained constant.

[0048] Next, the flow of the method for manufacturing the sealant tire according to the first embodiment will be described. FIG. 11 is a flowchart showing the flow of the manufacturing process of the sealant tire according to the first embodiment.

[0049] In step S11, a tire holding process is executed in which the tire 1 is held by the gripping portion 75 of the tire holding device 71. In the tire holding process, the tire 1 is attached to the tire holding device 71 in a state where the tire 1 and the nozzle 100 are relatively rotatable in the tire circumferential direction. In the present embodiment, the tire 1 is disposed on the base portion 76 of the gripping portion 75 of the tire holding device 71, and the tire 1 is attached to the tire holding device 71 by fixing with the arm portion 77. In the present embodiment, the tire holding device 71 rotates the tire 1, so that the tire 1 rotates relative to the nozzle 100.

[0050] In step S12, a process is executed in which the control device 81 moves the nozzle 100 whose relative position is fixed to the displacement meter 90 to the planned coating start position inside the tire 1 by the robot 72.

[0051] In step S13, a process is executed in which the control device 81 matches the position of the nozzle 100 to a distance based on the target sealant thickness. In this process, the control device 81 moves the nozzle 100 up and down by the robot 72 until the measurement result of the displacement gauge 90 matches the distance based on the target sealant thickness. Then, the control device 81 sets the position where the measurement result of the displacement gauge 90 matches the distance based on the target sealant thickness as the application start position of the nozzle 100, and the robot 72 controls the position of the nozzle 100 at the application start position. By this process, even when the inner surface of the tire 1 is not a perfect circle, such as when the tire 1 is deflected by the gripping of the gripping portion 75, the distance to the inner surface of the tire 1 at the start of application can be appropriately set.

[0052] In step S14, a process is executed in which the control device 81 applies the sealant material 61 while displacing the position of the nozzle 100 based on the distance to the inner surface measured by the displacement gauge 90. In this process, the sealant material 61 is applied while the measurement result of the displacement gauge 90 is reflected in real time in the position of the nozzle 100.

[0053] 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 turn with the movement in the tire rotation axis direction stopped, whereby one circumferential portion 62 is applied. The position of the nozzle 100 is stationary in the tire rotation axis direction in the circumferential portion 62, but is displaced in the tire radial direction based on the measurement result of the displacement gauge 90 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, the positions in both the tire radial direction and the tire rotation axis direction may be displaced depending on the inner surface shape.

[0054] Next, stop the movement in the tire rotation axis direction, and apply the circumferential portion 62 while displacing the position of the nozzle 100 based on the measurement result of the displacement meter 90 adjacent to the previously applied circumferential portion 62. By repeating the above operations, the sealant material 61 can be applied in steps to 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.

[0055] Next, a sealant application device 70 having a configuration different from that of the first embodiment will be described. In the description from the second embodiment onward, components that are common or similar to those of the first embodiment may be denoted by the same reference numerals, and detailed description thereof may be omitted.

[0056] Referring to FIG. 12, the displacement meter 90 according to the second embodiment will be described. FIG. 12 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 displacement meter 90 according to the second embodiment. In the second embodiment, the displacement meter 90 is fixed to the arm 72A of the robot 72 so as to be inclined with respect to the tire radial direction. The displacement meter 90 is arranged so as to be inclined with respect to the inner surface of the tire 1. Thereby, the measurement point can be brought closer to the application position of the nozzle 100 in the tire rotation axis direction, and real-time measurement can be performed more accurately. When the displacement meter 90 is inclined at an angle θ with respect to the tire radial direction (the direction orthogonal to the inner surface of the tire), the distance d1 between the nozzle opening 101 and the inner surface of the tire 1, or the distance d0 between the displacement meter 90 and the inner surface of the tire 1 may be calculated based on cos θ, and the position of the nozzle 100 may be controlled based on the calculated distance.

[0057] By adjusting the orientation of the displacement gauge 90 so that the measurement point of the displacement gauge 90 is on the front side in the traveling direction rather than at a position orthogonal to the nozzle 100, it becomes possible to measure the distance to the inner surface of the tire 1 immediately before coating. In this case, the orientation of the displacement gauge 90 is oblique with respect to both the tire rotation axis direction and the tire diameter direction. Considering the response performance (control time delay) of the robot 72, by setting the circumferential distance (distance in the traveling direction) from directly below the nozzle 100 to the measurement point, it is possible to effectively improve the followability of the position control of the nozzle 100 with respect to the actual distance to the inner surface of the tire 1. Also in this case, when the displacement gauge 90 is inclined at an angle θ with respect to the tire diameter direction, based on cos θ, the distance d1 between the nozzle opening 101 and the inner surface of the tire 1, or the distance d0 between the displacement gauge 90 and the inner surface of the tire 1 may be calculated, and the position of the nozzle 100 may be controlled based on the calculated distance.

[0058] Furthermore, a margin may be taken with respect to the circumferential distance from directly below the nozzle 100 to the measurement point, and delay control may be performed in which a delay is applied to the nozzle position control of the robot 72 in consideration of the margin. By using the delay control, even if the response performance of the position control of the robot 72 is low, the position control of the nozzle 100 can be performed precisely.

[0059] In the first and second embodiments, the displacement gauge 90 is configured to be fixed adjacent to the nozzle 100 in the tire rotation axis direction, but is not limited to this configuration. Next, referring to FIG. 13, the displacement gauge 90 according to the third embodiment will be described. FIG. 13 is a circumferential cross-sectional view of the tire showing a state in which the inner surface of the tire 1 is measured by the displacement gauge 90 according to the third embodiment.

[0060] As shown in FIG. 13, the displacement gauge 90 according to the third embodiment is fixed to the arm 72A of the robot 72 so as to be adjacent to the nozzle 100 in the tire circumferential direction. In terms of the traveling direction of the nozzle 100 that applies the sealant material 61, the displacement gauge 90 is located on the front side in the traveling direction of the nozzle 100. Also with this configuration, it is possible to measure the displacement of the distance to the inner surface of the tire 1 immediately before coating by the nozzle 100.

[0061] FIG. 14 is a cross-sectional view in the tire rotation axis direction showing a state where the inner surface of the tire 1 is measured by the displacement meter 90 according to the third embodiment. According to the configuration of the third embodiment, even in an R portion where the height difference of the inner surface of the tire 1 such as both ends in the tire rotation axis direction is large, since the displacement meter 90 is positioned in the circumferential direction with respect to the nozzle 100, the displacement of the distance to the inner surface of the tire 1 immediately before coating can be accurately measured. In this embodiment as well, the displacement meter 90 may be arranged obliquely with respect to the inner surface of the tire 1 so that the measurement point of the displacement meter 90 approaches the coating position of the nozzle 100 in the tire circumferential direction.

[0062] As described above, the embodiment in which the control for adjusting the position of the nozzle 100 in accordance with the measurement result of the displacement meter 90 is performed in real time has been described. However, the timing of the position control of the nozzle 100 is not limited to real-time control.

[0063] When the time of the measurement cycle based on the number of samplings in the displacement meter 90 is shorter than the time of the operation delay in the control of the robot 72, it may be difficult to perform real-time control. The time of the operation delay in the control of the robot 72 here is, for example, the time from the timing of issuing a movement command to the robot 72 to the timing of the robot 72 moving to the position corresponding to the movement command. More specifically, when the operation delay time (control delay time) from the movement command to the robot 72 until the movement of the robot 72 is completed is 5 ms, it is difficult to perform real-time control as described in the first to third embodiments unless the sampling of the displacement meter 90 is 200 Hz or less (the measurement cycle of the displacement meter 90 is 5 ms or more). There is a possibility that the position displacement of the nozzle 100 controlled by the robot 72 lags behind the measurement result of the displacement of the distance to the actual inner surface of the tire 1.

[0064] In the coating process, it is preferable that the position of the nozzle 100 is displaced at intervals corresponding to the measurement period of the displacement meter 90. Therefore, when the circumferential displacement of the inner surface of the assumed tire 1 is large and it is desired to frequently move the position of the nozzle 100, it may be desired to narrow the interval of the measurement period. For example, in order to accurately capture the unevenness of the inner surface shape of the tire 1, it may be desired to perform measurement by the displacement meter 90 at a measurement period exceeding 200 Hz (for example, 1000 Hz). However, it may be difficult to shorten the operation delay time in the control of the robot 72. In the fourth embodiment described below, an effective control method is executed in such a case.

[0065] Next, referring to FIG. 15, the fourth embodiment will be described. FIG. 15 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 displacement meter 90 according to the fourth embodiment.

[0066] As shown in FIG. 15, the displacement meter 90 according to the fourth embodiment is fixed to a support device 95 that can operate independently of the operation of the nozzle 100, and the relative position with respect to the nozzle 100 is not fixed, which is different from the device configuration of the above-described embodiment. The support device 95 may be any mechanism that can be independent of the operation of the nozzle 100, and may be arranged on the tire holding device 71 or may be a dedicated support device that supports the displacement meter 90.

[0067] In the fourth embodiment, after measuring the displacement of the distance to the inner surface of the tire 1 by the displacement meter 90 for at least one round, the coating process for one round by the nozzle 100 is executed. When the application of the sealant material 61 is performed a plurality of times in a circular motion like the step sticking as described above, the measurement by the displacement meter 90 for creating the nozzle position information for one round is executed every coating process. The position of the nozzle 100 is set based on the nozzle position information for one round.

[0068] Note that while the displacement meter 90 is measuring, the support device 95 supports the displacement meter 90 such that the distance between the center position of the nozzle 100 and the center position of the displacement meter 90 in the direction of the rotation axis is equal to the length of the nozzle opening 101. As a result, when the nozzle 100 is at the coating position after the third cycle, the displacement meter 90 can accurately measure the coating position for the next full rotation.

[0069] Also, in the present embodiment, since the support device 95 can operate independently of the nozzle 100, it is not affected by the displacement of the position of the nozzle 100 during the coating process. Therefore, although the measurement process needs to be performed alone only at the beginning, it can be performed in parallel with the coating process from the second time onwards. Since the measurement is performed for each rotation, the displacement of the inner surface shape in the tire rotation axis direction can also be accurately measured. If the inner surface shape of the tire 1 is displaced, even if the rotation angle is the same, the position of the nozzle 100 will change according to the inner surface shape in different rotations.

[0070] Referring to FIG. 16, the flow of the method for manufacturing the sealant tire according to the fourth embodiment will be described. FIG. 16 is a flowchart showing the flow of the manufacturing process of the sealant tire according to the fourth embodiment. The processes of step S21, step S22, and step S23 are the same as the processes of step S11, step S12, and step S13, respectively.

[0071] In step S24, a process of measuring the distance to the inner surface of the tire 1 for one full rotation by the displacement meter 90 is executed. In this process, the displacement meter 90 continuously measures the inner surface of the tire 1 rotated by the tire holding device 71. The displacement meter 90 can obtain data for the entire inner circumference of the tire 1 by continuing the measurement while the tire 1 makes one full rotation. Also, the measurement results measured by the displacement meter 90 are 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. Alternatively, the rotation angle may be obtained using the signal of the rotational drive of the tire holding device 71.

[0072] In step S25, a process is executed in which the control device 81 operates the robot 72 based on the measurement result of the displacement meter 90 one week ago to move the position of the nozzle 100. 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 measurement result one week ago corresponds to the position in the tire circumferential direction in the coating process.

[0073] In step S26, a process is executed in which the control device 81 determines whether or not the condition for completing the coating is satisfied. If the condition is not satisfied (step S26; No), the control device 81 returns the process to step S24, measures the displacement for one round of the coating range corresponding to the next circumferential portion 62, and performs the coating of the circumferential portion 62 based on the measurement result in the next step S25. When the control device 81 satisfies the condition for completing the coating (step S26; Yes), the process ends. The condition for completing the coating is, for example, that the coating of the last circumferential portion 62 is completed. Detection of whether or not the coating of the last circumferential portion 62 is completed can use various means such as sensors (not shown) such as the number of revolutions, rotation angle, coating amount, etc.

[0074] In the fourth embodiment, the displacement meter 90 is supported by the support device 95 that operates independently of the nozzle 100, but is not limited to this configuration. For example, similar to the first embodiment, the relative position between the displacement meter 90 and the nozzle 100 can be fixed. In this case, if the measurement for the second and subsequent times is performed simultaneously with the coating process, since the displacement meter 90 interlocks with the operation of the nozzle 100, accurate measurement results cannot be obtained as it is. Therefore, by correcting the displacement of the nozzle 100 in consideration of the measurement results for the second and subsequent times, the influence of the displacement of the nozzle 100 can be eliminated and accurate measurement results can be obtained.

[0075] Regarding the correction of measurement results, the case where it is necessary to maintain the thickness of the sealant layer 60 at 3 mm will be described as an example. When the coating process and the measurement process are carried out in parallel, it is assumed that the position of the nozzle 100 is moved 2 mm inward in the tire diameter direction according to the measurement results one week ago. At this time, the measurement results of the displacement gauge 90 without correction will include the amount of movement (2 mm) of the nozzle 100 inward in the tire diameter direction in the unevenness of the actual inner surface shape. Therefore, the control device 81 can eliminate the influence of the displacement of the nozzle 100 by performing a correction process of subtracting the amount of movement (2 mm) of the nozzle 100 from the measurement results.

[0076] As described above, the appropriate control method may differ depending on the relationship between the measurement cycle of the displacement gauge 90 and the operation delay time in the control of the robot 72. Next, a fifth embodiment will be described in which an appropriate control method is automatically selected based on the relationship between the measurement cycle of the displacement gauge 90 and the operation delay time in the control of the robot 72.

[0077] The configuration of the sealant application device 70 used in the fifth embodiment may be the same as the configuration of the first embodiment or the same as the configuration of the fourth embodiment. In the case of the same configuration as the first embodiment, as described above, a correction process for correcting the displacement of the nozzle 100 in consideration of the measurement results of the displacement gauge 90 after the second time is executed.

[0078] FIG. 17 is a flowchart showing the flow of the manufacturing process of the sealant tire of the fifth embodiment. The processes of step S31, step S32, and step S33 are the same as the processes of step S11, step S12, and step S13, respectively.

[0079] In step S34, a process is executed in which the control device 81 determines whether the set measurement period (time) is within the control delay time, that is, whether the measurement period (time) is shorter than the control delay time. The measurement period is, for example, a period (time) based on the number of samples of the displacement meter 90 set by the user or the displacement meter 90 to be used. The measurement period may be information input or selected by the user, or may be information automatically set by the displacement meter 90. When the set measurement period is within the control delay time (when the measurement period (time) is shorter than the control delay time), the control device 81 advances the process to step S36 (step S34; Yes). When the set measurement period is not within the control delay time (when the measurement period (time) is longer than the control delay time), the control device 81 advances the process to step S35 (step S34; No).

[0080] In step S35, a process is executed in which the control device 81 applies the sealant material 61 while displacing the position of the nozzle 100 based on the distance to the inner surface measured by the displacement meter 90. Step S35 is the same real-time process as step S14 and is a process with a relatively short time until application completion.

[0081] In step S36, a process is executed in which the displacement meter 90 measures the distance to the inner surface of the tire 1 for one full rotation. Next, in step S37, a process is executed in which the control device 81 operates the robot 72 based on the measurement result of the displacement meter 90 one rotation before and moves the position of the nozzle 100. In step S38, a process is executed in which the control device 81 determines whether the condition for completion of application is satisfied. Steps S36 to S38 are the same processes as the processes of steps S24 to S26, and relatively more precise nozzle position control is executed.

[0082] According to the above embodiment, the following effects are obtained.

[0083] (1) The sealant application device 70 according to the embodiment includes a nozzle 100 that discharges a sealant material 61, a displacement meter 90 that measures the displacement of the distance to the inner surface of the tire 1 to which the sealant material 61 is applied, and a robot (nozzle position control unit) 72 that controls the position of the nozzle 100 based on the measurement result of the displacement meter 90.

[0084] 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 is 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 to the application range with a thickness capable of holding air. Therefore, the thickness can be made as thin as possible while ensuring air holding, and both the durability and air holding property of the tire 1 can be realized.

[0085] Generally, in the inner surface shape of a tire, height differences such as unevenness (displacement of the position in the tire radial 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.

[0086] Further, the configuration of the present embodiment is also effective even when the tire is deformed radially inward by the pressing of the device that holds 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. The 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 is also effective. Even with such a sealant application device 70, a sealant layer 60 having high uniformity can be formed on the inner surface of the tire 1.

[0087] (2) The relative position in the radial direction of the nozzle 100 and the displacement meter 90 according to the embodiment of (1) with respect to the tire 1 is fixed.

[0088] Thereby, the distance from the nozzle 100 to the inner surface of the tire 1 can be calculated based on the fixed relative position from the measurement result of the displacement meter 90. There is no need to control the position of the displacement meter 90, and the measurement process can be executed with simple control.

[0089] (3) The sealant application device 70 according to the embodiment of (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 robot 72 measures the displacement meter 90 with respect to the inner surface of the tire 1 that is relatively rotated by the tire holding device 71 and controls the position of the nozzle 100 based on the measurement result of the displacement meter 90.

[0090] Thereby, since the measurement process and the application process are performed in parallel, the cycle time until the application is completed can be shortened, and the productivity can be improved.

[0091] (4) The sealant application device 70 according to the embodiment of (1) 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 displacement meter 90 measures the displacement of the distance to the inner surface of the tire 1 that is relatively rotated by the tire holding device 71 for one revolution. The robot 72 controls the position of the nozzle 100 based on the measurement result one revolution before of the displacement meter 90 with respect to the inner surface of the tire 1 that is relatively rotated by the tire holding device 71.

[0092] Thereby, even when the time of the measurement cycle is shorter than the robot control delay time, the distance from the nozzle 100 to the inner surface of the tire 1 can be accurately maintained constant. Also, since the measurement cycle can be shortened, it becomes possible to measure the displacement in the circumferential direction of the tire 1 more precisely. The displacement of the nozzle 100 in the application process also becomes precise according to the measurement cycle, and the uniformity of the sealant layer 60 can be further improved.

[0093] (5) The nozzle 100 and the displacement meter 90 according to the embodiments of (1) to (4) are arranged so as to be aligned in the tire rotation axis direction.

[0094] Thereby, for example, even in real-time control, the nozzle 100 can be displaced following the displacement of the inner surface of the tire that changes in the tire circumferential direction, so that the sealant layer 60 can be formed uniformly.

[0095] (6) The nozzle 100 and the displacement meter 90 according to the embodiments of (1) to (4) are arranged such that the displacement meter 90 is aligned on the front side in the traveling direction with respect to the nozzle 100 in the tire circumferential direction.

[0096] Thereby, the entire sealant application range including the R portions at both ends of the inner surface of the tire 1 in the tire rotation axis direction where the distance between the nozzle 100 and the inner surface of the tire 1 is displaced can be reliably measured. Since the displacement of the entire sealant application range can be measured, the uniformity in the tire rotation axis direction can be further improved.

[0097] (7) The method for manufacturing a sealant tire according to the embodiment includes a step of measuring the displacement of the distance to the inner surface of the tire 1 on which the sealant material 61 is applied by the displacement meter 90, a step of controlling the position of the nozzle 100 based on the measurement result of the displacement meter 90, and a step of discharging the sealant material 61 by the nozzle 100.

[0098] Also, according to the method for manufacturing a sealant tire according to the embodiment, 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, 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 set initially (the distance between the tip of the nozzle 100 and the inner surface of the tire 1) is constant regardless of the inner surface shape of the tire.

[0099] As described above, the embodiments have been described. However, the present invention is not limited to the above embodiments, and even if modifications, improvements, etc. are made within the scope where the object of the present invention can be achieved, they are included in the scope of the present invention.

[0100] For example, in the above embodiment, an example of applying the sealant material 61 by step sticking has been described. However, 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. However, the present invention can also be applied to a configuration in which the nozzle 100 is moved relative to the tire 1.

Explanation of Reference Numerals

[0101] 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 81 Control device 90 Displacement gauge 100 Nozzle

Claims

1. A sealant application device for forming a sealant layer on an inner surface of a tire, A nozzle for discharging a sealant material; a displacement meter that measures a displacement of a distance to an inner surface of the tire to which the sealant is applied; a nozzle position control unit that controls the position of the nozzle based on the measurement result of the displacement meter; A sealant application device comprising:

2. The relative positions of the nozzle and the displacement meter in the radial direction of the tire are fixed. The sealant applicator of claim 1 .

3. a tire holding portion that holds the tire so that the tire and the nozzle can rotate relatively in a tire circumferential direction; The nozzle position control unit is a displacement meter measuring an inner surface of the tire that is rotated relatively by the tire holding portion, and controlling a position of the nozzle based on a measurement result of the displacement meter; The sealant applicator of claim 2.

4. a tire holding portion that holds the tire so that the tire and the nozzle can rotate relatively in a tire circumferential direction; the displacement meter measures a displacement of a distance to an inner surface of the tire that is relatively rotated by the tire holding portion for one revolution, The nozzle position control unit is a position of the nozzle is controlled based on a measurement result of the displacement meter from one revolution before with respect to an inner surface of the tire that is relatively rotated by the tire holding portion; The sealant applicator of claim 1 .

5. The nozzle and the displacement meter are arranged to be aligned in the tire rotation axis direction.

5. The sealant applicator according to claim 1.

6. The nozzle and the displacement gauge are arranged in a tire circumferential direction such that the displacement gauge is aligned ahead of the nozzle in a traveling direction.

5. The sealant applicator according to claim 1.

7. A method for manufacturing a sealant tire by forming a sealant layer on an inner surface of a tire, comprising the steps of: a step of measuring a displacement of a distance to an inner surface of the tire to which a sealant material is applied using a displacement meter; controlling the position of the nozzle based on the measurement result of the displacement meter; A step of discharging a sealant material from a nozzle; A method for producing a sealant tire comprising the steps of:

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