Method for manufacturing non-pneumatic tires

Abstract

To provide a method for manufacturing a non-pneumatic tire that can suppress insufficient adhesion between a support structure and a tread member.SOLUTION: A method for manufacturing a non-pneumatic tire 100 includes: a molding process of a support structure 50; a removal process of a mold release agent; and an attaching process of a tread member 32. In the molding process of the support structure 50, the ring-shaped support structure 50 that is connected to an axle and attaches the tread member 32 to an outer surface 31a is molded. In the removal process of the mold release agent, the outer surface 31a is irradiated with a laser beam to remove the mold release agent. In the attaching process of the tread member 32, the tread member 32 is attached to the outer surface 31a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a non-pneumatic tire. [Background technology]

[0002] Non-pneumatic tires, which are constructed without inflating air, have the advantage of not requiring maintenance for issues such as loss of air pressure or punctures.

[0003] The non-pneumatic tire described in Patent Document 1 includes a support structure that supports a load from a vehicle and a tread member provided on the outer periphery of the support structure. The support structure includes an inner annular portion, an outer annular portion that is concentrically provided on the outside of the inner annular portion, and a plurality of connecting portions that connect the inner annular portion and the outer annular portion. Patent Document 1 describes that the outer periphery of the molded support structure is buffed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-219009 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the non-pneumatic tire described in Patent Document 1, random unevenness is formed on the outer peripheral surface of the support structure when the outer peripheral surface is buffed. Abrasive powder generated by the buffing process may remain on the uneven outer peripheral surface, and if the tread member is bonded with the abrasive powder remaining, the adhesive strength becomes uneven, and the tread member is likely to peel off in areas where the adhesive strength is insufficient.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for manufacturing a non-pneumatic tire that can suppress insufficient adhesion between a support structure and a tread member. [Means for solving the problem]

[0007] One aspect of the present invention is a method for manufacturing a non-pneumatic tire, the method comprising the steps of: forming a ring-shaped support structure connected to an axle and having a tread member attached to its outer peripheral surface; irradiating the outer peripheral surface with a laser beam to remove a release agent; and attaching the tread member to the outer peripheral surface. Effect of the Invention

[0008] According to the present invention, insufficient adhesion between the support structure and the tread member can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a non-pneumatic tire. [Diagram 2] FIG. 2 is a cross-sectional view of the non-pneumatic tire taken along line AA shown in FIG. [Diagram 3] 3 is a view of the connecting member as seen from a direction B shown in FIG. 2. [Figure 4] 1 is a flowchart showing a method for manufacturing a non-pneumatic tire. [Diagram 5] FIG. 2 is a block diagram showing a functional configuration of a release agent removal device used in a release agent removal step. [Figure 6] FIG. 2 is a schematic diagram for explaining a scanning route of a laser beam. [Figure 7] 10 is a flowchart showing a method for manufacturing a non-pneumatic tire according to a modified example. [Figure 8] 13A and 13B are schematic diagrams for explaining irradiation of laser light according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described below based on preferred embodiments with reference to Figures 1 to 8. The same or equivalent components and members shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The dimensions of the members in each drawing are enlarged or reduced as appropriate for ease of understanding. Some of the members that are not important for explaining the embodiments are omitted in each drawing.

[0011] (Embodiment) Fig. 1 is a side view of a non-pneumatic tire 100, and Fig. 2 is a cross-sectional view of the non-pneumatic tire 100 taken along line AA shown in Fig. 1. The non-pneumatic tire 100 has a wheel 10, an inner ring 20, an outer ring 30, and a connecting member 40. The inner ring 20 is cylindrical, and the wheel 10 is attached to its inner circumference. The wheel 10 is circular in side view, and an axle is attached to its center. The inner ring 20 is connected to the axle via the wheel 10.

[0012] The outer ring 30 is cylindrical and is provided radially outward of the inner ring 20. The outer ring 30 has a cylindrical base portion 31 and a cylindrical tread member 32 bonded to the outer periphery of the base portion 31, and the outer periphery of the tread member 32 comes into contact with the ground.

[0013] The connecting member 40 has a long and narrow plate shape with a plate surface facing the tire circumferential direction and connects the inner ring 20 and the outer ring 30. As shown in Fig. 2, the connecting member 40 has a first plate member 41 extending from one end of the inner ring 20 in the width direction (axial direction) to the other end of the outer ring 30 in the width direction, and a second plate member 42 extending from the other end of the inner ring 20 in the tire width direction (axial direction) to one end of the outer ring 30 in the width direction.

[0014] Fig. 3 is an arrow view of the connecting member 40 as viewed from the direction B shown in Fig. 2. The connecting member 40 has first plate members 41 and second plate members 42 arranged alternately in the tire circumferential direction. Returning to Fig. 2, the inner ring 20, the base portion 31 of the outer ring 30 and the connecting member 40 constitute a support structure 50 that supports a load from a vehicle. The inner ring 20, the base portion 31 of the outer ring 30 and the connecting member 40 that constitute the support structure 50 are all made of resin and are formed by integral molding. The support structure 50 uses a material such as thermosetting urethane.

[0015] The tread member 32 of the outer ring 30 is made of rubber and is bonded to the outer peripheral surface 31a of the integrally molded support structure 50. The tread member 32 is bonded to the outer peripheral surface 31a of the base portion 31 using, for example, an adhesive, double-sided tape, or the like.

[0016] 4 is a flowchart showing a method for manufacturing the non-pneumatic tire 100. The non-pneumatic tire 100 is manufactured through a molding step (S1) of the support structure 50, a release agent removal step (S2), and a tread member 32 attachment step (S3).

[0017] In the molding step (S1) of the support structure 50, a mold release agent is applied to a mold die, resin is filled, and the mold die is heated (for example, at 100°C to 160°C), and then cooled. After cooling, the support structure 50 is removed from the mold die. After the molding step of the support structure 50, the mold release agent remains on the outer peripheral surface 31a of the support structure 50. The mold release agent may be, for example, a composite coating type of a fluorine compound and silicone, which improves the releasability of the support structure 50. The mold release agent is applied to the mold die by a method such as spraying.

[0018] FIG. 5 is a block diagram showing the functional configuration of a release agent removing device 60 used in the release agent removing step. The release agent removing device 60 includes a laser irradiation unit 61, a control table 62, and a control unit 63, and irradiates the outer peripheral surface 31a of the support structure 50 with a laser beam to sublimate and remove the release agent. The laser irradiation unit 61 includes a laser oscillator 61a and an optical scanning unit 61b. The laser oscillator 61a may be a device using various laser oscillation methods, such as a CO2 laser, a fiber laser, or a YAG laser. The type of laser to be used may be appropriately selected since the absorption rate of the laser beam changes depending on the material of the support structure 50. For example, a CO2 laser exhibits performance such as a wavelength of 1064 nm and an output of 40 W.

[0019] The optical scanning unit 61b irradiates the laser light output from the laser oscillator 61a onto the target object using a reflection or focusing optical system. The optical scanning unit 61b moves the spot onto which the laser light is irradiated one-dimensionally or two-dimensionally by rotating optical elements such as a reflecting mirror and a focusing lens. The laser irradiation unit 61 is capable of laser scanning with a spot diameter of 20 μm, a scanning range of 200 mm×200 mm, and a scanning speed in the range of 10 to 1200 mm / s, for example.

[0020] The control stand 62 supports the support structure 50 rotatably about the tire axis, and has a rotation drive unit 62a that rotates the support structure 50. The control stand 62 also has a position drive unit 62b that adjusts the relative position of the support structure 50 and the laser irradiation unit 61 in three axial directions.

[0021] The control unit 63 controls the on / off of laser light irradiation by the laser irradiation unit 61 and the movement of the laser light spot position. The control unit 63 also controls the position adjustment of the support structure 50 by the control table 62 and the rotation of the support structure 50 around the tire axis. Information such as the external shape of the support structure 50 is input from an input unit 64.

[0022] 4, in the release agent removal step (S2), information such as the outer shape of support structure 50 is input to control unit 63 of release agent removal device 60, and support structure 50 is attached to control stand 62. The position of support structure 50 is adjusted to the start position for laser light irradiation, and a route for scanning the laser light from the start position to the end position is set based on the spot diameter of the laser light.

[0023] 6 is a schematic diagram for explaining the scanning route of the laser light. The laser light spot S travels along a route that repeats one revolution in the tire circumferential direction and a distance L1 in the tire width direction on the outer peripheral surface 31a of the support structure 50 from the starting position to the end position. The laser light spot S is moved so as to overlap with each revolution. That is, if the diameter of the laser light spot S is D, the following formula is satisfied. L1 <D ····(1)

[0024] When irradiating the laser light, the control stand 62 rotates the support structure 50 around the tire axis. In addition, the movement of the laser light spot S in the tire width direction may be performed by moving the irradiation position of the laser light by the laser irradiation unit 61, or the control stand 62 may move the support structure 50 in the tire width direction.

[0025] In the process of removing the release agent, the outer peripheral surface 31a of the support structure 50 is irradiated with laser light without leaving any gaps, thereby sublimating and removing the release agent.

[0026] In the step (S3) of attaching the tread component 32, an adhesive is applied to the outer peripheral surface 31a of the support structure 50, and after drying for a predetermined time, the tread component 32 is placed on the outer peripheral surface 31a. The adhesive is dried, for example, at a temperature of 80°C for a predetermined time of 10 minutes. The surface layer of the tread component 32 in contact with the adhesive is vulcanized, for example, at 110°C or higher, to complete the adhesion.

[0027] Fig. 7 is a flowchart showing a manufacturing method of a non-pneumatic tire 100 according to a modified example. This manufacturing method includes a step of forming irregularities on the outer peripheral surface (S13) after a step of removing the release agent. Steps S11, S12, and S14 are similar to steps S1, S2, and S3 in Fig. 4 described above, respectively, and therefore will not be described.

[0028] In the step of forming unevenness on the outer peripheral surface (S13), the output of the laser light is appropriately increased or decreased from the step of removing the mold release agent to the output for forming unevenness. Fig. 8 is a schematic diagram for explaining the irradiation of the laser light according to the modified example. In the step of forming unevenness on the outer peripheral surface (S13), the laser light is irradiated onto the outer peripheral surface 31a from the starting position to the end position by repeatedly turning the laser light on and off intermittently and moving the spot position of the laser light.

[0029] In the process of forming the unevenness on the outer peripheral surface, the diameter D of the spot is set to be smaller than the distance L2 between the center of the spot S irradiated with the laser light and the center of the adjacent spot S, so that the spots do not overlap. In other words, the following formula is satisfied. D <L2 ····(2)

[0030] In the step of forming the unevenness on the outer peripheral surface, recesses are formed on the outer peripheral surface 31a, and the spaces between the recesses are convex, resulting in an overall uneven state. The diameter of the recesses formed on the outer peripheral surface 31a by the step of forming the unevenness on the outer peripheral surface may be set to, for example, a range of 3 μm or more and 20 μm or less depending on the spot diameter of the laser light.

[0031] The depth of the recesses can be appropriately set depending on the material of the support structure 50 and the irradiation energy and spot diameter of the laser light. The adhesive enters the recesses formed in the outer circumferential surface 31a, thereby increasing the adhesive strength of the tread component 32.

[0032] Next, the operation of the non-pneumatic tire 100 will be described based on each step in the above-described manufacturing method. In the mold release agent removal step, the mold release agent adhering to the outer peripheral surface 31a of the support structure 50 of the non-pneumatic tire 100 is sublimated and removed by irradiating laser light. For example, polishing powder generated during buffing does not occur, and insufficient adhesion between the support structure 50 and the tread member 32 can be suppressed.

[0033] In the mold release agent removal step, the laser light spots are scanned on the outer peripheral surface 31a of the support structure 50 so as to satisfy the relationship of the above-described formula (1), whereby the spots overlap, and the mold release agent can be removed without gaps. Since the intensity distribution within the laser light spot is large at the spot center and small at the periphery, uniform irradiation energy can be achieved by overlapping the spots when scanning the laser light on the outer peripheral surface 31a.

[0034] The condition for the laser light spots to overlap is as shown in the above-described formula (1). However, in order to achieve uniform irradiation energy, the laser light may be irradiated under the condition of L1 < D / 2.

[0035] Also, as shown in the modified example, after the mold release agent removal step, an unevenness forming step of intermittently turning on and off the laser light irradiation on the outer peripheral surface 31a may be further added. By forming the unevenness on the outer peripheral surface 31a, the adhesive enters the recesses and the adhesive strength increases.

[0036] In the unevenness forming step of the outer peripheral surface 31a, the laser light spots are scanned so as to satisfy the above-described formula (2), whereby the spots do not overlap and the recesses can be easily formed. If the surface roughness Ra of the outer peripheral surface 31a is about 10 μm, peeling of the tread member in the support structure 50 is less likely to occur. Note that the surface roughness Ra represents the arithmetic mean roughness.

[0037] The support structure 50 is composed of an inner ring 20, an outer ring 30 (base portion 31), and a connecting member 40 that connects the inner ring 20 and the outer ring 30, whereby weight reduction can be achieved.

[0038] The connecting member 40 is configured by arranging first plate members 41 and second plate members 42 alternately in the circumferential direction. The first plate member 41 extends from one end of the inner ring 20 in the width direction to the other end of the outer ring 30 in the width direction. The second plate member 42 extends from the other end of the inner ring 20 in the width direction to one end of the outer ring 30 in the width direction. The first plate member 41 and the second plate member 42 can provide high rigidity to the non-pneumatic tire 100.

[0039] In the above embodiment, in the release agent removal step, an example has been shown in which the laser light spot repeats a route that moves around once in the tire circumferential direction on the outer peripheral surface 31a of the support structure 50, but it may repeat a route that goes back and forth in the tire width direction. In this case, the laser light spot repeats a route that moves from a start position on the outer peripheral surface 31a from one end to the other end in the tire width direction, moves in the tire circumferential direction, and then moves from the other end to one end again, making a round trip.

[0040] Next, features of the manufacturing method of the non-pneumatic tire 100 according to the embodiment will be described. The manufacturing method of the non-pneumatic tire 100 according to the embodiment includes a molding step of the support structure 50, a release agent removal step, and a tread member 32 attachment step. In the molding step of the support structure 50, a ring-shaped support structure 50 is molded, which is connected to an axle and has the tread member 32 attached to its outer peripheral surface 31a. In the release agent removal step, the outer peripheral surface 31a is irradiated with a laser beam to remove the release agent. In the tread member 32 attachment step, the tread member 32 is attached to the outer peripheral surface 31a. According to this manufacturing method of the non-pneumatic tire 100, the release agent is sublimated and removed by irradiation with a laser beam, so that no abrasive powder is generated, which is generated, for example, in a buffing process, and insufficient adhesion between the support structure 50 and the tread member 32 can be suppressed.

[0041] In addition, in the release agent removal process, the laser beam is scanned so that the spots of the laser beam overlap on the outer peripheral surface 31a. According to this method for manufacturing the non-pneumatic tire 100, the spots of the laser beam overlap when scanning the outer peripheral surface 31a, thereby making it possible to uniformize the irradiation energy.

[0042] In addition, after the release agent removal step, the method further includes an unevenness forming step of forming unevenness on the outer peripheral surface by intermittently irradiating the laser light on and off. According to this manufacturing method for the non-pneumatic tire 100, by forming unevenness on the outer peripheral surface 31a, adhesive enters the recesses and the adhesive strength of the tread member 32 is increased.

[0043] In the unevenness forming step, the laser light is irradiated so that the spots do not overlap. According to this manufacturing method for the non-pneumatic tire 100, the spots do not overlap, and recesses can be easily formed.

[0044] In addition, the support structure 50 has an inner ring 20 connected to an axle, a base portion 31 of the outer ring 30 to which the tread member 32 is attached, and a connecting member 40 that connects the inner ring 20 and the outer ring 30. According to this manufacturing method for the non-pneumatic tire 100, the weight of the manufactured non-pneumatic tire 100 can be reduced.

[0045] The connecting member 40 is configured by circumferentially arranging a first plate member 41 extending from one widthwise end of the inner ring 20 to the other widthwise end of the outer ring 30, and a second plate member 42 extending from the other widthwise end of the inner ring 20 to one widthwise end of the outer ring 30. According to this manufacturing method for the non-pneumatic tire 100, it is possible to increase the rigidity of the manufactured non-pneumatic tire 100.

[0046] The above description is based on the embodiments of the present invention. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications and changes are possible within the scope of the claims of the present invention, and that such modifications and changes are also within the scope of the claims of the present invention. Therefore, the descriptions and drawings in this specification should be treated as illustrative rather than restrictive. [Explanation of symbols]

[0047] 20 inner ring, 30 outer ring, 31a outer circumferential surface, 32 tread member, 40 connecting member, 41 first plate member, 42 second plate member, 50 support structure, 100 non-pneumatic tire.

Claims

1. a molding process for molding a ring-shaped support structure that is connected to an axle and has a tread member attached to an outer peripheral surface thereof; a step of supporting the support structure rotatably around a tire axis and attaching the support structure to a control stand having a rotation drive unit that rotates the support structure; a removing step of removing the release agent by irradiating the outer peripheral surface with a laser beam by repeatedly moving a spot of the laser beam in a tire circumferential direction or reciprocating in a tire width direction; a bonding step of bonding the tread member to the outer circumferential surface; A method for manufacturing a non-pneumatic tire, comprising:

2. The method for manufacturing a non-pneumatic tire according to claim 1 , wherein the removing step scans the outer circumferential surface with overlapping spots of laser light.

3. 3. The method for manufacturing a non-pneumatic tire according to claim 1, further comprising, after the removing step, a step of forming irregularities on the outer peripheral surface by intermittently irradiating a laser beam on and off.

4. The method for manufacturing a non-pneumatic tire as described in Claim 3, characterized in that the unevenness forming process irradiates laser light so that the spots do not overlap.

5. 5. The method for manufacturing a non-pneumatic tire according to claim 1, wherein the support structure includes an inner ring connected to an axle, an outer ring to which the tread member is attached, and a connecting member connecting the inner ring and the outer ring.

6. 6. The method for manufacturing a non-pneumatic tire as described in claim 5, characterized in that the connecting member is composed of a first plate member extending from one widthwise end of the inner ring to the other widthwise end of the outer ring, and a second plate member extending from the other widthwise end of the inner ring to one widthwise end of the outer ring, arranged in a circumferential direction.

Images