JPH0731408U - Flat tire - Google Patents

Abstract

(57) [Summary] [Purpose] To improve riding comfort and reduce rolling friction in puncture-less tires. A punctureless tire main body 2 is mounted on a rim 3 of a wheel and has an annular first tire member 10
And a second tire member 11. The second tire member 11 is an annular member made of an elastic material that is fixed to the outer peripheral side of the first tire member 10. First tire member 10 and second
A sealed annular cavity 12 for absorbing shock is formed between the tire member 11 and the inner wall of the outer periphery of the annular cavity 12 when the load exceeds a certain level and the spring constant increases in accordance with the increase in the load. The leaf spring ring 14 is arranged so that

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a puncture tire, and more particularly to a puncture tire mounted on a wheel rim.

[0002]

[Prior art and its problems]

 As this type of puncture tire, for example, a solid tire disclosed in USP 4,446,903 is known. This solid tire is made of urethane foam rubber having a tread on the outer circumference, and a plurality of beads for preventing elongation due to centrifugal force are embedded inside the inner circumference. In this solid tire, if the cushioning properties of urethane foam rubber are improved to improve riding comfort, the amount of deformation on the ground contact surface increases and internal friction increases. When the internal friction increases, the elastic hysteresis loss increases, and the rolling friction increases in accordance with this elastic hysteresis loss. For this reason, power loss during traveling becomes large, and a large amount of power is required for traveling.

As a conventional technique for reducing rolling friction, a solid tire disclosed in Japanese Utility Model Laid-Open No. 55-127603 is known. In this solid tire, rubber with a substantially triangular cross section is fixed to the rim so that its apex contacts the ground, and the ground contact area is reduced to reduce rolling friction. However, since the solid tire has a triangular cross-section, it is difficult to improve the riding comfort, and it can be mainly used only for narrow applications such as racing bicycles.

An object of the present invention is to provide a puncture-less tire with good riding comfort and low rolling friction.

[0005]

[Means for Solving the Problems]

 A punctureless tire according to the present invention is mounted on a rim of a wheel, and includes a ring-shaped first tire member, a second tire member, and a shock absorbing means. The second tire member is an annular member made of an elastic material that is fixed to the outer peripheral side of the first tire member. The shock absorbing means is an annular closed cavity formed between the first tire member and the second tire member, and the load is increased when the load exceeds a certain load, which is arranged on the outer peripheral side of the closed cavity. Accordingly, the elastic member has an annular plate-like elastic member having a smaller spring constant.

[0006]

[Action]

 In the puncture-type tire according to the present invention, when the ground contact surface of the second tire member is elastically deformed during traveling, the plate-shaped elastic member constituting the shock absorbing means is flexed according to the load. This elastic member has a smaller spring constant as the load increases above a certain load. When the deformed portion is separated from the ground by the rotation, the elastic member restores the deformation of the second tire member.

Here, since the closed cavity is formed inside, the elastic hysteresis loss is smaller than that of the solid tire, and the rolling friction is accordingly reduced. Further, since it is not necessary to limit the shapes of the first tire member and the second tire member, it is possible to improve the ride comfort by appropriately determining the elastic constant of the plate-shaped annular member and the shape of the second tire member. It is possible to improve. Further, when the load increases above a certain level, the spring constant decreases, so when the load exceeds a certain level, the stroke increases and the impact is further mitigated, which improves ride comfort. Further, since the annular plate-shaped elastic member is arranged on the outer peripheral side of the closed cavity, puncture does not occur.

[0008]

【Example】

 In FIG. 1, a wheel 1 to which an embodiment of the present invention is applied is, for example, a tire main body 2 having the same shape as a 26 × 1 −3/8 inch bicycle tire, and a tire main body 2 for mounting the tire main body 2. It is mainly composed of a rim 3, a hub 5 arranged at the center, and a plurality of spokes 4 connecting the hub 5 and the rim 3.

The tire body 2 includes a first tire member 10 having a flat T-shaped cross section attached to the rim 3, and an outer diameter of 26 × 1-3 / fixed to the outer peripheral side of the first tire member 10. It has the same second tire member 11 as the bicycle tire of 8 inches. The first tire member 10 is an annular member made of urethane rubber that does not easily fall off the rim 3 and has a low elasticity. The second tire member 11 is an annular member made of urethane foam which is highly flexible in consideration of cushioning properties, and is an annular member for forming a closed annular cavity 12 having a substantially rectangular cross section with the first tire member 10. The groove 13 is formed inside. A wide accommodating portion 15 is formed at the bottom of the annular groove 13, and an annular leaf spring ring 14 is mounted therein.

As shown in FIGS. 3 and 4, the leaf spring ring 14 is a ring-shaped member in which the ends of an arc-shaped leaf spring whose cross section is curved toward the outer peripheral side are joined by, for example, welding. The outer diameter of the plate panel ring 14 is substantially equal to the inner diameter of the annular cavity 12 in the second tire member 11. As shown in FIG. 4 (a), the leaf spring ring 14 has a shape in which the degree of curvature of the cross section is large, and a load is applied to the storage portion 15 as shown in FIG. 4 (b). It is installed with a slight degree of bending and tension applied to the outer circumference. When a load is applied at the time of grounding, as shown in FIG. 4C, the center portion of the cross section is elastically deformed so as to recede toward the inner peripheral side.

FIG. 5 shows how the stroke changes with the load of the leaf spring ring 14 at this time. The leaf spring ring 14 is attached to the storage portion 15 by applying a load Ls. When a load larger than the load Ls and larger than the load Lm acts, the spring constant decreases as the load increases. As a result, the stroke of the leaf spring ring 14 is extended and the shock is easily absorbed.

Next, the operation of the wheel 1 during traveling will be described. When the wheel 1 is mounted on a bicycle and a load is applied to the bicycle, the ground contact portion of the tire body 2 is elastically deformed by the load. When the vehicle moves away from the ground contact surface by traveling, the elastic force of the second tire member 11 and the leaf spring ring 14 restores the original state. The internal friction at the time of elastic deformation is smaller than that of a solid tire because the annular cavity 12 is formed. As a result, elastic hysteresis loss is smaller than that of solid tires, and rolling resistance is reduced. Therefore, power loss during traveling is reduced, and power can be efficiently transmitted from the wheels to the ground. Further, since it is not necessary to limit the shape of the tire, it is possible to improve the riding comfort. Further, even if a hole is formed in the annular hollow portion 12, the second tire member 11 is supported by the leaf spring ring 14 so that it is not punctured. Further, when a load larger than the normal load is applied, the spring constant of the leaf spring ring 14 becomes small and the amount of deformation becomes large. Therefore, even if a large load is applied, it can be reliably absorbed by the large stroke, and the shock given to the driver is reduced.

[Other Embodiments] The present invention can be applied to wheels for other vehicles such as a hand cart and a forklift, instead of wheels for a bicycle.

[0014]

[Effect of device]

 In the puncture-type tire according to the present invention, an annular closed cavity is formed between the first tire member and the second tire member, and an annular plate-like elastic member is arranged on the outer peripheral side of the closed cavity. Therefore, compared with solid tires, internal friction is smaller and rolling resistance is smaller. Further, since it is not necessary to limit the shapes of the first tire member and the second tire member, it is possible to improve the riding comfort by appropriately determining the spring constant of the elastic member and the material of the second tire member. . In addition, since the spring constant decreases as the load increases, the amount of elastic deformation increases when a large load is applied, and riding comfort can be improved. Further, since the annular plate-shaped elastic member is arranged on the outer peripheral side of the closed cavity, puncture does not occur.

[Brief description of drawings]

FIG. 1 is a side view of a wheel according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of an elastic member.

FIG. 4 is a cross-sectional view showing the shape of the leaf spring ring when it is deformed.

FIG. 5 is a graph showing load characteristics of a leaf spring ring.

[Explanation of symbols]

 2 Tire Main Body 10 First Tire Member 11 Second Tire Member 12 Annular Cavity 14 Leaf Spring Ring

Claims (1)

[Scope of utility model registration request] 1. A puncture-less tire mounted on a rim of a wheel, comprising: an annular first tire member; and an elastic annular second tire member fixed to an outer peripheral side of the first tire member. An annular closed cavity portion formed between the first tire member and the second tire member, and a spring constant arranged on the outer peripheral side of the closed cavity portion at a certain load or more in accordance with an increase in the load. And a shock absorbing means having an annular plate-like elastic member having a small size.