JP2005343277A - Wheel with roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly prevent generation of cracks for respective rollers 9 at a solid tire portion due to formation of a flange part 15a at a base end of a rotation shaft 15 mounted with a solid tire 10 in a wheel with rollers. <P>SOLUTION: Respective rollers 9 comprises a rotation shaft 15 supported by a rim part 3b rotatably around a rotary axis crossing in a radial direction with an axle 1 as a center, and a solid tire 10 mounted around it. A tire tip portion 12 partially enters a recessed part 17 formed at a tire base end portion 11. A part 15b swollen forward and backward and toward a tire outer periphery 19 is formed at an circular outer periphery of the flange part 15a, and the outer periphery on the tire outer periphery 19 side, and corner parts between tip ends on the tire tip portion 12 side and between base ends on the tire base end portion are formed in curved surfases respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a plurality of rollers that rotate in a direction orthogonal to a straight traveling direction of a wheel are arranged on a rim portion around a disc wheel portion having an axle at the center, and each roller is centered on the axle. A rotary shaft that is supported by the rim portion so as to be rotatable about a rotation axis that intersects the radial direction and that has a disc-like flange portion formed at the base end portion, and is mounted around the rotary shaft The tire outer peripheral surface is formed into a shape that forms an arc of a wheel outer peripheral circle by gradually increasing the diameter from the tip toward the base end, and the tire tip portion of each solid tire is With a roller that partially penetrates into a recess formed so that the inner diameter gradually decreases toward the front so that the tire proximal end is adjacent to the adjacent tire proximal end on the wheel outer circumference. Wheel It relates.

According to Patent Document 1 by the present applicant, this type of omnidirectional wheel with a rotating body is well known, and as shown in FIG. 6, the roller (rotating body) is rotatable on a support shaft provided along the rim portion. A solid tire 45 having a semi-spindle outer peripheral surface is mounted around an iron pipe-shaped rotating shaft 40 supported by the disk, and a disc-shaped flange portion 41 is provided at the base end portion of the rotating shaft 40 for reinforcement. Is formed to balance the compression deformation of the solid tire 45 whose diameter gradually increases toward the base end. Further, the outer peripheral portion of the flange portion 41 is formed as a curved portion 42 having the same plate thickness so as to enter the tire base end portion 45a that gradually becomes thinner from the base end portion of the rotating shaft 40 toward the base end side. .
Japanese Patent Laid-Open No. 2004-9818

  By such a roller structure having a rotating shaft with a flange, even if the diameter of the solid tire 45 increases toward the base end side, it is possible to suppress fluctuations in the amount of elastic compression or buffering action with respect to the wheel load. However, a relatively large shear stress is generated in the solid tire portion around the edge of the tip of the curved portion 42 over time, so that a crack is generated in the direction toward the axle as indicated by a dotted line, and the cut is gradually formed. There is room for improvement in terms of depth. As a countermeasure, it is conceivable to round the edge, but the effect is limited by the thickness of the flange portion 41, and the finish tends to vary.

  In view of such a point, the present invention can uniformly prevent the possibility of cracks in the solid tire portion due to the formation of the flange portion at the base end portion of the rotating shaft for each roller. The object is to provide a wheel with rollers of the kind mentioned at the beginning.

  In order to achieve this object, according to the present invention, a plurality of rollers rotating in a direction orthogonal to the straight traveling direction of a wheel are provided on a rim portion around a disc wheel portion having an axle at the center. In addition to being arranged, each roller is supported by the rim portion so as to be rotatable about a rotation axis intersecting with the radial direction centering on the axle, and a disc-shaped flange portion is formed at the base end portion. Consists of a rotating shaft and a solid tire mounted around the rotating shaft, and the outer peripheral surface of the tire has a shape that forms a circular arc of a wheel outer peripheral circle by gradually increasing the diameter from the tip toward the base end Formed so that the inner diameter of the tire end portion gradually decreases toward the front so that the tire front end portion of each solid tire is close to the adjacent tire base end portion on the wheel outer circumference circle. Is In a wheel with a roller that partially penetrates into the recess, a bulging portion that bulges toward the tire front end portion side, the tire base end portion side, and the tire outer peripheral surface side with respect to the flange portion on the circular outer peripheral portion of the flange portion The outer peripheral surface portion that bulges toward the tire outer peripheral surface side of the bulging portion, the corner portion between the distal end surface portion that bulges toward the tire distal end portion side and the proximal end surface portion that bulges toward the tire proximal end portion side, respectively, are curved. It was formed in the shape.

  A flange portion is formed at the base end portion of the rotating shaft, thereby limiting the amount of elastic compression of the solid tire portion where the tire outer peripheral surface has a larger diameter than the tire front end. When the load applied to the bulging part from the tire outer peripheral surface on the wheel outer peripheral circle during running is received by the bulging part outer peripheral surface where the front and rear corner parts are curved, shear stress is locally applied to the tire part on the outer peripheral part of the flange part. Concentration is avoided.

  In order to ensure the integration of the solid tire with respect to the rotating shaft, according to claim 2, the flange portion is intermittently perforated in the circumferential direction, and the rubber solid tire surrounds the rotating shaft. , And is integrally formed with the rotating shaft so as to close the perforations. In order to facilitate turning of the electric wheelchair and to make it run smoothly with a small gap between the rollers, the electric wheelchair is used as a front wheel of an electric wheelchair having four wheels.

  According to the first aspect of the present invention, the diameter of the solid tire-type roller that can turn the vehicle in the forward / backward oblique or lateral direction without requiring turning in the direction of travel as in the case of a caster. When the flange portion adjusts the increase in the amount of elastic compression of the tire base end portion where the tire becomes relatively large, a curved bulge is formed on the outer peripheral portion thereof, so that the tire portion in the outer peripheral region of the flange portion is formed. Cracks are prevented and the durability of the roller is improved, and the thickness of the flange is expanded and shaped, making it easier to make the shape uniform and eliminating variations in durability performance from roller to roller. Is done. According to the invention of claim 2, the solid tire is reliably mounted on the rotating shaft by the tire portion entering the perforated portion during integral molding. According to the invention of claim 3, even when the solid tire type roller is adopted as an omnidirectional wheel in an electric wheelchair, the cushioning action of the solid tire is made uniform in the wheel outer peripheral direction and excellent durability is obtained.

  The wheel with a roller used for the front wheel of the electric wheelchair by embodiment of this invention is demonstrated based on FIG. 1 thru | or FIG. As shown in FIG. 4, this electric wheelchair is motor-driven by a rear wheel 5 and is provided with a seating portion 7 above the front wheel 6 supported by a tip portion of an arm 6a, and a seat back 8 is provided behind the seating portion 7. Yes. The front wheel 6 has a diameter large enough to easily overcome a step such as a sidewalk between the roads, and the front wheel 6 rotates on the rim portion 3b of the outer peripheral portion of the disc wheel portion 3 having the axle 1 at the center. A plurality of rollers 9 having the same shape rotating in a direction perpendicular to the surface are arranged.

  As shown in FIG. 1 and FIG. 2, each roller 9 has a die around the rotating shaft 15 made of iron pipe and having a disk-shaped flange portion 15a formed at the base end. In the state where the rubber solid tire 10 is attached to the semi-spindle shape from the integral molding by the above-described method, the shaft is rotated in a state in which the rubber penetrates and closes the perforations 15c formed intermittently in the circumferential direction in the flange portion 15a. 15 is integrally formed in a solid shape. The rotation shaft 15 of each roller 9 is flush with the radial circle with respect to the direction of the radius R1 centered on the rotation axis O of the axle 1 supported by the tip portion of the arm 6a, and is in the orthogonal direction, that is, 90. They are arranged so as to be rotatable around a rotation axis X1 that obliquely intersects at an angle smaller than 0 °. The number of rollers 9 is set to be as large as possible so that the gap 19a is made as small as possible and the step of the tire front end portion 12 in the gap is reduced in a range where the cost can be compromised. The crossing angle is defined according to the number.

  As shown in FIG. 2A, each roller 9 is set such that the minimum diameter D1 on the front end side of the solid tire 10 is about 30 mm, the maximum diameter D2 on the base end side is about 60 mm, and the front-rear width W is 50 mm. Further, the diameter of the outer peripheral surface continuously decreases from the tire base end portion 11 toward the tire front end portion 12, and the circular arc is formed at a position where the tire outer peripheral surface 19 rotates to the wheel outer peripheral circle C1 of the front wheel 6. Therefore, each tire outer peripheral surface 19 is formed in a semi-spindle shape. Further, the outer periphery of a substantially frustoconical concave portion 17 in which the tire distal end portion 12 is formed in the tire proximal end portion 11 closer to the proximal end than the flange portion 15a (FIG. 2B) and the inner diameter gradually decreases toward the front. By partially penetrating the side half, the tire outer peripheral surface 19 rotated to the wheel outer peripheral circle C1 can come close to the tire base end portion 11 of the adjacent roller 9 with a gap 19a around several millimeters.

  As shown in FIGS. 1 and 3, the disc wheel portion 3 is formed as a bearing portion 3 a whose central portion is rotatably supported by the axle 1, and a concave groove 27 is formed on the outer peripheral portion around the rotational axis O. A rim portion 3b is formed. In this groove, the arc-shaped base 29 of the bearing arm 20 is attached with bolts 26 in order in a state where the arc-shaped base 29 of the bearing arm 20 partially enters and engages with the notch 29a. The bearing arm 20 provided with the ribs 28 on both sides enters the gap between the inner peripheral surface of the recess 17 and the tire outer peripheral surface 19, and further enters the gap between the tire front end portions 12 to belong to the two rotating shafts 15. The base end portion of the rotary shaft 15 is supported by the support shaft portion 21 at a midway position, and the tip end portion of the rotary shaft 15 of the adjacent roller 9 is supported at the tip position. The shaft portion 22 is rotatably supported.

  As shown in an enlarged view in FIG. 2A, the circular outer peripheral portion of the disc-shaped flange portion 15a of the rotating shaft 15 is separated from the distal end side and the rotating end 15 along the rotating shaft 15, that is, the radiation direction. A bulging portion 15b in the direction is formed in a ring shape over the entire circumference. The outer peripheral surface portion 150 is a flat surface inclined along the tire outer peripheral surface 19 where the diameter of the solid tire 10 gradually increases, and a corner portion between the curved base end surface portions 151 is formed in a curved shape. Yes. Further, the corner portion between the outer peripheral surface portion 150 and the distal end surface portion 152 that is flat in the radial direction is also formed in a curved surface shape. Furthermore, the thickness T between the top of the bulging portion 15b and the tire outer peripheral surface 19 is set to about 5 mm. At that time, the tire base end portion 11 is gradually thinned toward the base end by the substantially frustoconical inner peripheral surface, and therefore the thickness is increased to 5 mm as described above by further expanding the bulging portion 15b in the base end direction. On the other hand, if the thickness becomes thinner than that, the cushioning action as a tire is reduced, and the crack strength is reduced and peeling at the tire base end portion 11 occurs. It is terminated halfway without.

  The operation of the wheelchair employing the front wheel 6 configured in this way is as follows. The electric wheelchair can go straight without rotating the roller 9 and can move backward. The entire tire outer peripheral surface 19 of the roller 9 can form a substantially continuous wheel outer peripheral circle C1, and the gap 19a between the front and rear ends of the roller 9 is so small that the respective rotating operations do not interfere with each other. This prevents the stones from getting caught and ensures smooth running.

  When the vehicle is steered diagonally, the front wheel 6 rotates about its axle 1 and the roller 9 also rotates about the rotation shaft 15 in accordance with the vector component force decomposed in the orthogonal direction of the traveling force, and the traveling direction of the wheelchair Turns diagonally forward or backward. At this time, the roller 9 is skewed without widening the width of the front wheel 6 due to non-turning of the roller 9. Since the tire outer peripheral surface 19 of the roller 9 is continuous with the outer periphery of the front wheel 6 having a sufficient diameter, the step of the road surface can be easily climbed without being caught.

  During traveling, the solid tire 10 of the roller 9 tends to increase in compressive deformation at the tire base end portion 11, but its compressive strength is compensated by the flange portion 15 a of the rotating shaft 15 and the tire portion in the vicinity thereof is compensated. The curved surface shape suppresses the generation of excessive shear stress. The unreinforced tire portion into which the bulging portion 15b closer to the base end has not penetrated is located between the tire portion near the bulging portion 15b and the tire tip portion 12 of the adjacent roller 9, thereby restricting compression deformation. Thus, fluctuations in the buffering action are suppressed.

  As shown in FIG. 5, the bulging portion can be modified in other modifications, and the bulging portion 15d has a perfectly circular cross section as shown in FIG. A according to the characteristics, shape, etc. of the solid tire. It is also conceivable that the bulging portion 15e is formed in a semi-elliptical shape on the base end side and enters the tapered base end portion.

The partial side view made into the partial cross section of the wheel with a roller by an embodiment of the invention. FIG. 2 is an enlarged view of the roller, where FIG. A is a cross-sectional view and FIG. B is a rear view of the rotating shaft. It is a front view of the bearing arm which supports the roller. It is a side view of the electric wheelchair using the wheel with the roller. It is a fragmentary sectional view of the roller by another embodiment. It is sectional drawing of the conventional roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axle 3 Disc wheel part 3b Rim part 6 Front wheel 9 Roller 10 Solid tire 11 Tire base end part 12 Tire tip part 15 Rotating shaft 15a Flange part 15b, 15d, 15e Swelling part 17 Recessed part 19 Tire outer peripheral surface 20 Bearing arm 150 Swelling Outer peripheral surface portion of the ridge portion 151 Base end surface portion of the bulge portion 152 Front end surface portion of the bulge portion C1 Wheel outer circumference circle

Claims (3)

A plurality of rollers rotating in a direction orthogonal to the straight direction of the wheel are arranged on the rim portion around the disc wheel portion having the axle at the center, and each roller is arranged in a radial direction around the axle. A rotating shaft that is supported by a rim portion so as to be rotatable around a rotation axis that intersects the rotating shaft and has a disc-shaped flange portion formed at the base end portion, and a solid tire that is mounted around the rotating shaft. The tire outer peripheral surface is formed into a shape that forms a circular arc of the wheel outer peripheral circle by gradually increasing the diameter from the tip toward the base end, and the tire tip portion of each solid tire is on the wheel outer peripheral circle. In the wheel with a roller partially invading into the recess formed so that the inner diameter gradually decreases toward the front so that the tire base end portion is adjacent to the tire base end portion adjacent to each other,
A bulging portion that bulges toward the tire front end portion side, the tire base end portion side, and the tire outer peripheral surface side with respect to the flange portion is formed on the circular outer peripheral portion of the flange portion, and the tire outer periphery of the bulging portion A roller characterized in that an outer peripheral surface portion that swells to the surface side, a corner portion between a front end surface portion that swells toward the tire front end portion side and a base end surface portion that swells toward the tire base end portion side, are formed into curved shapes, respectively. With wheels.   A perforation is intermittently formed in the circumferential direction of the flange portion, and a rubber solid tire is integrally formed with the rotation shaft so as to surround the rotation shaft and close the perforation. The roller wheel according to claim 1.     The wheel with roller according to claim 1 or 2, wherein the wheel wheel is used as a front wheel of an electric wheelchair having four wheels.

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