JPH10315701A - Vehicle tire and vehicle using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an electric motor car chair easy to escape from a side groove by concentrically providing first tire part and second tire part whose diameters are different on the side of the shaft direction. SOLUTION: A solid tire part 7b is arranged more inward than a pneumatic tire part 7a and has a wider width s 2 than a width s 1 of the pneumatic tire part 7a. On the outer peripheral surface of this solid tire part 7b, a plurality of projections 17b are formed in the circumferential direction. These projections 17b play a role of increasing rolling resistance of the solid tire part 7b. The pneumatic tire part 7b expands and contracts by adjusting air quantity. When the pneumatic tire part 7b expands, the diameter becomes larger than the diameter (R2×2) of a solid tire 7b and when the pneumatic tire part 7b contracts, the diameter becomes smaller than the diameter (R2×2) of the solid tire part 7b. In a normal traveling, the pneumatic tire part 7b expands by air and the diameter of the pneumatic tire part 7a is (R1×2) which is larger than the solid tire part 7b (R2×2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire for a vehicle, a vehicle using the same, and more particularly to a tire for a vehicle that easily escapes from a side gutter while maintaining a low rolling resistance when traveling on a normal road surface. The present invention relates to a vehicle tire that can run on both a road surface and a rough road surface such as sandy ground without changing tires.

[0002]

2. Description of the Related Art An electric wheelchair for the elderly and the physically handicapped has a maximum speed limited to a predetermined speed and can run on a sidewalk. In a vehicle that needs to travel on a road surface such as a sandy ground, a wide balloon tire suitable for traveling on such a road surface is mounted.

[0003]

However, there is a case where there is a gutter beside a sidewalk on which an electric wheelchair runs. Therefore, when the front wheel or the rear wheel of the electric wheelchair fits in this gutter, it is not easy for the elderly or the like to lift the wheel from the gutter by themselves. Also,
If the vehicle runs on a normal paved road with the balloon tires suitable for traveling on sandy ground, the balloon tires are wide and have a high rolling resistance against the paved road surface, resulting in poor fuel economy and noise. Becomes bigger. In order to avoid this, it is necessary to exchange tires between a normal road surface and a rough road surface such as sand.

An object of the present invention is to provide a tire in which an electric wheelchair can easily escape from a gutter. Another object of the present invention is to provide a tire that allows a vehicle to run on a normal road surface and a rough road surface such as sandy ground without changing tires while suppressing deterioration in fuel efficiency and the like.

[0005]

According to a first aspect of the present invention, there is provided a vehicle tire mounted on a vehicle and rolling on a ground contact surface, comprising a first tire portion and a second tire portion. ing. The diameter of the second tire portion is smaller than the diameter of the first tire portion. The second tire portion is provided concentrically on the axial side of the first tire portion.

When the vehicle tire according to the present invention is mounted on a vehicle, since the diameter of the first tire portion is larger than the diameter of the second tire portion, the first tire portion normally rolls on the ground contact surface. .
When the first tire portion falls into a gutter or the like,
When the tire portion is buried in sand or the like, the second tire portion comes into contact with the ground contact surface. When the second tire portion abuts on the tread, even if the first tire portion falls into the gutter, the second tire portion remains on the tread so that the first tire portion can escape from the gutter. Become. That is, if the vehicle tire described in this claim is mounted, the vehicle easily escapes from the side groove.

Further, since the second tire portion is in contact with the contact surface, the first tire portion is buried in sand or the like, and a sufficient frictional resistance is obtained between the first tire portion and the contact surface such as sand only. Even when the vehicle cannot travel without running, frictional resistance acts between the second tire portion and the ground contact surface, so that idling of the vehicle tire is suppressed. That is, by providing the second tire portion, the traveling performance of the vehicle on a rough road surface (ground contact surface) such as sandy ground is improved.

On the other hand, a normal road surface such as a paved road (ground contact surface)
When running on a vehicle, only the first tire portion of the vehicle equipped with the vehicle tire according to the present invention rolls on the contact surface, so that only the first tire portion generates rolling friction resistance with the contact surface. The second tire portion that is not grounded does not occur. That is, since the vehicle tire is composed of at least two tire portions having different diameters, the rolling friction of the vehicle tire when traveling on a normal road surface is compared with a case where a wide vehicle tire is simply mounted. Problems such as increased fuel resistance and reduced fuel economy and quietness can be suppressed.

As described above, when the vehicle tire according to the present invention is mounted on a vehicle, for example, a wheelchair, it is possible to easily escape from the side gutter while suppressing deterioration of the running performance of the wheelchair on a normal road surface. Can be. Also, if the vehicle tire according to the present invention is mounted on a vehicle that may travel on a rough road,
It is possible to improve the running performance on rough road surfaces such as sandy grounds while suppressing the deterioration of the running performance of the vehicle on a normal road surface.

According to a second aspect of the present invention, in the vehicle tire according to the first aspect, the rolling resistance between the first tire portion and the ground surface is smaller than the rolling resistance between the second tire portion and the ground surface. small. Here, since the rolling resistance of the second tire portion with the ground contact surface is larger than the rolling resistance of the first tire portion with the contact surface, the vehicle equipped with the vehicle tire according to the present invention is not suitable for use in a rough surface such as sand. When traveling on a rough road, the vehicle travels mainly due to rolling frictional resistance between the second tire portion and the road surface. That is, the second tire portion is a portion mainly for traveling on a rough road surface, and the first tire portion is a portion mainly for traveling on a normal road surface. The rolling resistance of the second tire portion is set to be large in order to improve the running performance on a rough road, and the rolling of the first tire portion is improved in order to improve the fuel efficiency and quietness when running on a normal road surface. The resistance is set small.

According to a third aspect of the invention, in the vehicle tire according to the first or second aspect, the width of the second tire portion is wider than the width of the first tire portion. Here, since the width of the second tire portion is wider than the width of the first tire portion, a vehicle equipped with the vehicle tire according to the present invention, for example, a wheelchair, has a small width during normal running and is Since the vehicle travels on the first tire portion having a small rolling resistance, fuel efficiency and quietness are good. On the other hand, when the first tire portion fits in the gutter, the width of the second tire portion is larger than the width of the first tire portion, so that the problem that the second tire portion gets stuck in the gutter is suppressed.

According to a fourth aspect of the present invention, there is provided a vehicle tire mounted on a vehicle and rolling on a ground contact surface, and includes a first tire portion and a second tire portion. The second tire portion is provided concentrically on the axial side of the first tire portion. The first tire portion is inflatable by air, and has a larger diameter than the second tire portion when inflated,
By adjusting the amount of air, the diameter can be smaller than the diameter of the second tire portion.

When the vehicle tire according to the present invention is mounted on a vehicle, the diameter of the first tire portion is larger than the diameter of the second tire portion when the first tire portion is inflated.
The tire rolls on the tread. Then, when the first tire portion falls into a gutter or the like, or when the first tire portion is buried in sand or the like, the second tire portion comes into contact with the ground contact surface. When the second tire portion abuts on the tread, even if the first tire portion falls into the gutter, the second tire portion remains on the tread so that the first tire portion can escape from the gutter. Become. That is, if the vehicle tire described in this claim is mounted, the vehicle easily escapes from the side groove.

Further, since the second tire portion is in contact with the ground contact surface, the first tire portion is buried in sand or the like, and a sufficient frictional resistance between the first tire portion and the ground surface such as sand is obtained. Even when the vehicle cannot travel without running, frictional resistance acts between the second tire portion and the ground contact surface, so that idling of the vehicle tire is suppressed. That is, by providing the second tire portion, the traveling performance of the vehicle on a rough road surface (ground contact surface) such as sandy ground is improved.

On the other hand, a normal road surface such as a paved road (ground contact surface)
When running on a vehicle, only the first tire portion of the vehicle equipped with the vehicle tire according to the present invention rolls on the contact surface, so that only the first tire portion generates rolling friction resistance with the contact surface. The second tire portion that is not grounded does not occur. That is, since the vehicle tire is composed of at least two tire portions having different diameters, the rolling friction of the vehicle tire when traveling on a normal road surface is compared with a case where a wide vehicle tire is simply mounted. Problems such as increased fuel resistance and reduced fuel economy and quietness can be suppressed.

As described above, when the first tire portion is inflated, the first tire portion rolls on the ground contact surface, but when the first tire portion falls into a gutter or when the first tire portion is in a sandy ground or the like. When buried in, the second tire portion comes into contact with the ground contact surface. When the first tire portion falls into a gutter or the like, the second tire portion remains on the ground contact surface, so that the first tire portion can escape from the gutter, and the first tire portion is buried in sand or the like. In this case, the rolling resistance between the second tire portion and the ground contact surface suppresses the idling of the vehicle tire.

However, when the first tire part falls into a gutter or the like, even if the second tire part rolls on the ground contact surface, there is a step due to the difference in diameter between the first tire part and the second tire part. Therefore, it cannot escape from the gutter smoothly. Further, since there is a step due to a difference in diameter between the first tire portion and the second tire portion, the first tire portion cannot escape from the side groove unless the angle of the vehicle tire with respect to the side groove is equal to or more than a predetermined value. Increasing the angle of the vehicle tire may cause both the first tire portion and the second tire portion to fall into the side grooves.

Further, when the first tire portion is buried in sand or the like, there is a step due to a difference in diameter between the first tire portion and the second tire portion, so that the stability of the vehicle deteriorates depending on the condition of the road surface. . Here, the diameter of the first tire portion can be made smaller than the diameter of the second tire portion by adjusting the amount of air. Therefore, when the first tire portion falls into a gutter or the like, if the second tire portion is rolled after the diameter of the first tire portion is made smaller or equal to the diameter of the second tire portion, the gutter can be smoothly formed. You can escape from Further, it is not necessary to form an angle of the vehicle tire with respect to the side groove in order to allow the first tire portion to escape from the side groove, thereby suppressing a problem that both tire portions are fitted into the side groove.

In this case, when the first tire portion is buried in sand or the like, the diameter of the first tire portion is adjusted to impair the stability of the vehicle by adjusting the diameter of the first tire portion. Therefore, it is possible to improve the traveling performance of the vehicle on a rough road surface such as a sandy ground. A vehicle according to a fifth aspect includes a main body, an axle, and a vehicle tire. The axle is rotatably mounted on the main body. The vehicle tire is a vehicle tire according to any one of claims 1 to 4, and is connected to an axle.

[0020]

1 and 2 show an electric wheelchair equipped with a vehicle tire according to an embodiment of the present invention. FIG. 1 is a top view of the wheelchair 1, and FIG. 2 is a side view of the wheelchair 1. The wheelchair 1 mainly includes a main body 2, a seat 3, a steering wheel 4, a front wheel (vehicle tire) 5, a left rear wheel (vehicle tire) 6, and a right rear wheel (vehicle tire) 7.
And a drive unit (not shown) in the drive unit cover 8 and an operation panel 20.

The front part of the main body 2 is inclined so that the driver's feet can be easily placed. The seat 3 is fixed to a rear part of the main body 2. The handle 4 is rotatably mounted on a front portion of the main body 2 via a bearing, and has a lower end divided into two branches and rotatably supports both ends of an axle to which the front wheel 5 is fixed. Further, an upper part of the steering wheel 4 is formed with an annular operation part 4a for the driver to grip and steer.

The front wheel 5 is a front wheel rim 5d fixed to the axle.
And a pneumatic tire portion (first tire portion) 5a and solid tire portions (second tire portions) 5b and 5c fixed to the outer peripheral surface of the front wheel rim 5d. Solid tire part 5
b and 5c are arranged on the left and right sides of the pneumatic tire portion 5a, and each have a width larger than the width of the pneumatic tire portion 5a. The pneumatic tire portion 5a expands and contracts by adjusting the amount of air. When the pneumatic tire portion 5a is inflated, its diameter is larger than the diameter of the solid tire portions 5b and 5c, and when it is contracted. Solid tire portions 5b, 5 with diameters
It becomes smaller than the diameter of c. During normal running, the pneumatic tire portion 5a is inflated by air, and the diameter of the pneumatic tire portion 5a is larger than the diameter of the solid tire portions 5b and 5c.

Since the left and right rear wheels 6 and 7 have the same structure, the right rear wheel 7 will be described. An enlarged view and an enlarged sectional view of the right rear wheel 7 are shown in FIGS. The right rear wheel 7 includes a rear wheel rim 7c, a pneumatic tire portion (first tire portion) 7a and a solid tire portion (second tire portion) 7b fixed to the outer peripheral surface of the rear wheel rim 7c. I have. The rear wheel rim 7 c is fixed to a rim fixing device 10 fixed to an end of the rear wheel axle 9 by a bolt 11.

The solid tire portion 7b is disposed inside the pneumatic tire portion 7a, and has a width s1 of the pneumatic tire portion 7a.
It has a width s2 wider than that. This solid tire part 7b
A plurality of protrusions 17b are formed in the circumferential direction on the outer peripheral surface of the solid tire portion 7b, and play a role of increasing the rolling resistance of the solid tire portion 7b. Also, the projection 17b
Are also arranged in the width direction of the solid tire portion 7b. Thereby, the skidding of the solid tire portion 7b is suppressed.

The pneumatic tire portion 7a expands and contracts by adjusting the amount of air. When the pneumatic tire portion 7a is inflated, its diameter is larger than the diameter (R2 × 2) of the solid tire portion 7b. When the tire is contracted, the diameter of the solid tire portion 7 is reduced.
b is smaller than the diameter (R2 × 2). In normal running, the pneumatic tire portion 7a is inflated by air,
The diameter of the pneumatic tire portion 7a is equal to the diameter of the solid tire portion 7b (R2 ×
The diameter (R1 × 2) is larger than 2). A plurality of grooves 17a are formed on the outer peripheral surface of the pneumatic tire portion 7a along the circumferential direction. Due to the presence of the groove 17a, the ground contact area of the pneumatic tire portion 7a when grounding on a normal paved road surface is reduced. Since the pneumatic tire portion 7a has the width s1 which is the same as the width of the wheel of the conventional wheelchair and the presence of the groove 17a, the rolling resistance is equal to or less than the wheel of the conventional wheelchair. .

The driving device is disposed in a driving device cover 8 fixed to the main body 2 below the seat 3 and mainly includes a battery, a motor for controlling a variable rotation speed, a reduction gear mechanism, and a rear wheel. And an axle 9. The rotation of the motor operated by the battery is reduced by the reduction gear mechanism to rotate the rear wheel axle 9. The operation panel 20 is fixed to the center of the operation section 4a of the handle 4. Operation panel 2
0 is provided with a main switch, operation buttons for controlling traveling speed and forward / reverse travel, a brake switch, other keys and warning lights.

Next, the operation of the wheelchair 1 will be described.
The driver sits on the seat 3 and turns the operation unit 4a of the steering wheel 4 to steer the front wheel 5, and operates switches on the operation panel 20 to move forward and backward to adjust the traveling speed. The wheelchair 1 mainly runs on the sidewalk, and a side groove may be provided beside the sidewalk. FIG.
5 shows a state in which the left rear wheel 6 of the wheelchair 1 running on the sidewalk 60 has fallen into the side groove 61 as viewed from the back. Here, the pneumatic tire portion 6a falls into the side groove 61, but the solid rear tire portion 6b comes into contact with the sidewalk 60, thereby preventing the entire left rear wheel 6 from falling into the side groove 61.

In order for the pneumatic tire portion 6a to escape from the side groove 61 from the state in which the pneumatic tire portion 6a has fallen into the side groove 61 as shown in FIG. The vehicle returns to the sidewalk 60 over the corner of the side groove 61 side end of the sidewalk 60. Normally, the wheelchair 1 can be returned to the sidewalk 60 by performing the above.
In some cases, it is difficult to move the front wheel 5 largely rightward because the width of the sidewalk 60 is narrow. Then, since there is a step (R1-R2) due to a difference in diameter between the pneumatic tire portion 6a and the solid tire portion 6b, the tire cannot escape from the side groove 61 properly. In such a case, the air in the pneumatic tire portion 6a is evacuated so that the diameter of the pneumatic tire portion 6a approaches the diameter of the solid tire portion 6b (see FIG. 6). Thereafter, if the front wheel 5 is made to move forward slightly to the right, the left wheel 6 gradually escapes from the side groove 61. In addition, since the left wheel 6 escapes from the side groove 61 smoothly, the pneumatic tire portion 6a can be prevented from being rubbed against the corner between the side groove 61 and the sidewalk 60 and damaged.

On the other hand, when the wheelchair 1 of the present embodiment travels on a normal road surface (a sidewalk or the like), the solid tire portions 5b, 5c, 6b, 7b having a large width s2 and a high rolling resistance do not touch the road surface, Pneumatic tire portions 5a, 6 with low rolling resistance
Since only a and 7a are in contact with the road surface, fuel efficiency and quietness can be ensured as compared with a conventional wheelchair. [Other Embodiments] The vehicle tires (the front wheel 5, the left rear wheel 6, and the right rear wheel 7) described in the above embodiment can be mounted on a vehicle running on both a normal road surface and a sandy ground.

Here, the narrow pneumatic tire portions 5a, 6
a, 7a buried in sand, but wide solid tire part 5
Since the wheels b, 5c, 6b, and 7b are in contact with the sandy ground, the tires of the vehicle can be prevented from running idle. That is, the traveling performance of the vehicle on the sandy ground is improved. On the other hand, when traveling on a normal road surface, the solid tire portions 5b and 5
Since c, 6b, and 7b do not touch the road surface, and only the pneumatic tire portions 5a, 6a, and 7a with low rolling resistance touch the road surface, fuel efficiency and quietness are ensured as compared with conventional vehicles.

[0031]

According to the present invention, since the vehicle tire is composed of at least two tire portions having different diameters, the vehicle can easily escape from the side groove while suppressing the deterioration of the traveling performance of the vehicle on a normal road surface. Or, the traveling performance on rough roads such as sandy ground is improved.

[Brief description of the drawings]

FIG. 1 is a top view of a wheelchair according to an embodiment of the present invention.

FIG. 2 is a side view of a wheelchair.

FIG. 3 is an enlarged view of a right wheel.

FIG. 4 is an enlarged sectional view of a right wheel.

FIG. 5 is a schematic view of a state of a wheelchair.

FIG. 6 is a schematic diagram of a state of a wheelchair.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wheelchair (vehicle) 2 Main body 5 Front wheel (vehicle tire) 5a Pneumatic tire part (first tire part) 5b, 5c Solid tire part (second tire part) 6 Left rear wheel (vehicle tire) 6a Pneumatic tire part (First tire part) 6b Solid tire part (second tire part) 7 Right rear wheel (vehicle tire) 7a Pneumatic tire part (first tire part) 7b Solid tire part (second tire part)

Claims (5)

[Claims] 1. A tire for a vehicle mounted on a vehicle and rolling on a ground contact surface, comprising: a first tire portion; and a first tire portion provided concentrically on an axial side of the first tire portion. A second tire portion having a diameter smaller than the diameter of the vehicle tire. 2. The vehicle tire according to claim 1, wherein a rolling resistance of the first tire portion with the contact surface is smaller than a rolling resistance of the second tire portion with the contact surface. 3. The vehicle tire according to claim 1, wherein the second tire portion has a width wider than a width of the first tire portion. 4. A vehicular tire mounted on a vehicle and rolling on a ground contact surface, wherein a second tire is provided concentrically on an axial side of the first tire portion.
A tire portion, wherein the first tire portion is inflatable by air, and when inflated, the diameter is larger than the diameter of the second tire portion, and the diameter is adjusted by adjusting the amount of air. The second
A vehicle tire that can be smaller than the diameter of the tire portion. 5. A vehicle comprising: a main body; an axle rotatably mounted on the main body; and the vehicle tire according to claim 1, which is connected to the axle.