JP2007022138A - Tire for wheel-in-motor vehicle, and wheel system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire for a wheel-in-motor vehicle which sufficiently eliminates fear of the reduction in stability of a car body resulting from a rapid internal pressure reduction without spoiling the cushioning property and the wear resistance and so forth of the tire, and at the same time, sufficiently reduces the outer diameter of the tire. <P>SOLUTION: This tire 13 is applied to a pair of wheel-in-motor type wheels which are fitted on each side section of a step 2. In a rubber outer skin 11, a closed cell foam 12 of which the apparent specific gravity is 0.78 to 5.4 mN/cm<SP>3</SP>, and of which the expansion ratio is 1,275 to 100% is housed and arranged. Then, the outer diameter D is set to be 120 to 450 mm, and the grounding width W is set to be 50 to 100 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In this invention, a pair of wheels incorporating a motor is attached to both sides of one vehicle body step, and the balance of the vehicle is controlled by sensing the movement of the center of gravity of the operator standing on the step by a gyro mechanism or the like. In addition, a tire for a small and light single-seat wheel-in-motor vehicle capable of controlling the running and stopping of the vehicle based on the movement of the center of gravity of the control vehicle, and a wheel using the tire. It is about the system.

  For such a wheel-in-motor vehicle that does not have a suspension device such as a so-called four-wheel vehicle, the cushioning property is used in order to exhibit a running stability on an unpaved road surface and a shock absorbing function on a road surface step. An excellent pneumatic tire is used, and in order to secure a space for housing the motor inside the wheel, the tire and the inner diameter of the wheel have been made sufficiently large.

  However, when a pneumatic tire is used for such a vehicle, there is a risk that the stability of the vehicle body is impaired due to a sudden decrease in internal pressure due to tire puncture, etc., and the vehicle may fall over due to loss of control. Yes, as the inner diameter of the tire and wheel increases, the outer diameter of the tire also inevitably increases, and the ground height of the vehicle body step becomes high, making it difficult to get on and off the vehicle. There was a problem.

  Here, as a means for suppressing the increase of the outer diameter while increasing the inner diameter of the tire, it is conceivable to increase the flatness of the tire and reduce the cross-sectional height thereof. If it is extremely large, the tire width is also considerably widened, so that there is another problem that it becomes impossible to secure a sufficient clearance in the wheel housing depending on the vehicle.

  For this reason, in order to eliminate the risk of a rapid decrease in the tire internal pressure and to reduce the outer diameter of the tire to a small diameter as required without the risk of tire interference in the wheel housing, the tire itself is simply Although it is proposed to use a solid tire that has a solid structure with a single rubber material, in this case, the use of high-hardness rubber impairs cushioning, and the use of low-hardness rubber results in wear resistance of the tire. There was a problem that the property was impaired.

  An object of the present invention is to solve all the problems of the prior art, and the object of the present invention is to make rapid progress without impairing the cushioning property, wear resistance, etc. of the tire. Tire for wheel-in-motor vehicle and wheel system using the same, which can sufficiently eliminate the possibility of lowering the stability of the vehicle body due to a decrease in internal pressure and can sufficiently reduce the outer diameter of the tire To provide.

The tire for a wheel-in-motor vehicle according to the present invention is applied to a wheel-in-motor type wheel, and has an apparent specific gravity of 0.78 to 5.4 mN / cm ³ and a foaming rate in a rubber outer shell. Is housed and disposed of 1275 to 100% closed cell foam, the outer diameter is 120 to 450 mm, and the ground contact width is 50 to 100 mm.
Here, the storage arrangement of the foam in the rubber outer skin is performed under the form in which the inner peripheral surface of the foam is exposed to the inner peripheral side of the tire in the cross-section in the width direction of the tire. It can also be carried out as a form completely surrounded by a rubber shell.

  Also, here, the outer contour shape of the rubber hull in the cross section in the width direction of the tire, in particular, the contact surface contour shape is a toroidal curve shape for the type in which the inner pressure is filled between the rubber hull and the foam. However, in the case of a type that does not fill the internal pressure, a low flat shape or the like can be selected as appropriate.

  In such a tire, in order to further reduce the size and weight of the vehicle, it is preferable to set the outer diameter of the tire to 120 to 250 mm and the flatness ratio to 20 to 50%.

  A wheel system using a tire for a wheel-in motor vehicle according to the present invention is a wheel system in which any of the above-described tires is mounted around a rim of a wheel having an inner diameter of 80 to 400 mm to form a pair of wheels. Each wheel is connected to each side portion of the vehicle body step of the wheel-in motor vehicle via a motor housed within the inner diameter of the wheel.

  Here, for example, in the case of a small tire having a tire outer diameter of 120 to 250 mm and the rubber outer skin does not have a skeleton reinforcing member corresponding to a so-called carcass, bead core, etc., the tire slips on the rim. In order to prevent detachment from the rim, etc., at least one of the rubber outer shell and the foam is chemically or physically fixed to the peripheral surface of the rim by vulcanization or the like, and the contact portion of the tire with the peripheral surface of the rim In addition, a diameter expansion constraining layer made up of a non-extensible or low-extensible cord or the like is embedded to prevent the deformation of the contact portion, and the wheel is provided with a convex portion that prevents rim detachment and rim sliding. Etc. are effective.

  By the way, in such a wheel system, for example, under the filling posture of a predetermined internal pressure (for example, 80 kPa) between the rubber outer shell and the foam, the inner surface of the rubber outer shell and the foam surface on the equator plane of the tire The ratio (d / H) of the distance d to the radial distance H between the inner surface of the rubber skin and the wheel rim surface can be set to 0 to 0.2.

  Here, the tire in which the ratio (d / H) is 0 is of a type that does not fill the inner pressure between the rubber shell and the foam, and the wheel system using such a tire has an outer diameter of 120. A tire having a diameter of ˜250 mm and a flatness ratio of 20% to 50% is mounted around a rim of a wheel having an inner diameter of 80 to 400 mm to form a wheel, and each wheel is on each side of a vehicle body step of a wheel-in motor vehicle. Connected to the wheel through a motor housed within the inner diameter of the wheel, where the inner surface of the rubber outer shell and the wheel at a distance d between the inner surface of the rubber outer shell and the foam surface on the equator plane of the tire. The ratio (d / H) to the distance H to the rim surface is 0, and the ratio of the rubber shell cross-sectional area to the foam cross-sectional area in the cross-section in the width direction of the wheel is 15/85 to 85/15. It is obtained by the range.

  In the tire according to the present invention, when the foam is housed and disposed in the rubber sheath, and the type is filled with a predetermined internal pressure between them, the cushioning performance is exhibited with the filled internal pressure and the foam. In addition, even if puncture or the like occurs in the rubber shell and the internal pressure leaks suddenly, the stability of the vehicle body is sufficiently secured by supporting the shoulder of the load by the foam, and the required Can exhibit the cushioning properties.

  On the other hand, in the type that does not fill the internal pressure, it is possible to exert excellent cushioning properties by the internal foam while ensuring the wear resistance by the rubber shell.

Here, when the apparent specific gravity of the foam is less than 0.78 mN / cm ³ and the foaming ratio exceeds 1275%, the rigidity of the tire is insufficient to contribute to supporting the load of the foam, and the steering of the vehicle Stability will be impaired.
On the other hand, if the apparent specific gravity exceeds 5.4 mN / cm ³ and the foaming rate is less than 100%, the tire rigidity becomes too high and the cushioning property is insufficient, and the impact input from the road surface step makes the passenger uncomfortable, In addition, there is a high possibility that the motor unit, the control unit, etc. of the vehicle will be damaged.

Moreover, in this tire, by making the outer diameter 120 to 450 mm, it is possible to realize a reduction in size and weight of the vehicle as expected while ensuring a sufficient wheel inner diameter necessary for housing the motor. it can.
That is, if the outer diameter is less than 120 mm, it is difficult to secure the required wheel inner diameter, and it is difficult to get over the step on the stepped road surface, and if it exceeds 4500 mm, it is difficult to reduce the vehicle size and weight. In addition, the step height is too high, making it difficult to get on and off.

Moreover, by setting the ground contact width of the tire to 50 to 100 mm, sufficient load supporting strength can be imparted to the tire without impairing the handling performance of the vehicle.
In other words, if the ground contact width is less than 50 mm, the tire cannot be given sufficient strength to support the vehicle and the occupant. If it exceeds 100 mm, the handling of the vehicle becomes worse and the size of the vehicle becomes smaller. Realization of weight reduction becomes difficult.

By the way, in such a tire, when the outer diameter is 120 to 250 mm, particularly small, and the flatness is 20 to 50%, the necessary wheel inner diameter is preferentially secured. As a result, the tire height here cannot be secured to form the inner pressure filling space between the rubber skin and the foam, so the tire here is a solid that has a two-layer structure of the rubber skin and the foam. Become a tire.
Therefore, various physical properties, characteristics, and the like of the tire can be easily achieved as expected based on appropriate selection of the material and volume ratio of the two.

  On the other hand, when the tire outer diameter exceeds 250 mm, or the tire flatness exceeds 50%, an internal pressure filling space is provided between the rubber shell and the foam as required. It is possible to ensure a dimensional allowance for forming the.

In the former wheel system according to the present invention using any of the tires as described above, the inner diameter of the wheel is set to 80 to 400 mm, so that it is required within the inner diameter of the wheel while reducing the size and weight of the vehicle. Can accommodate a motor with the ability.
That is, if the inner diameter of the wheel is less than 80 mm, the motor with the required output cannot be accommodated in the wheel, and if it exceeds 400 mm, the outer diameter of the tire cannot be reduced, and the reduction in size and weight of the vehicle is impeded. Will be.

In this system, when the ratio (d / H) of the distance d between the rubber outer skin inner surface and the foam surface to the distance H between the rubber outer skin inner surface and the wheel rim surface is 0.2 or less. In particular, when the internal pressure is filled between the rubber shell and the foam, the internal pressure leaks out, and the reduced diameter of the tire is kept sufficiently small to effectively prevent an unexpected decrease in vehicle stability. can do.
In other words, if the ratio (d / H) exceeds 0.2, the diameter difference between the pair of wheels becomes too large due to the puncture of the rubber shell, etc., so that stability may be lost and posture control may become impossible. Becomes higher.

On the other hand, in the latter wheel system according to the present invention, the ratio (d / H) is 0, and the foam always contacts the inner surface of the rubber outer skin. By setting the ratio to the foam cross-sectional area in the range of 15/85 to 85/15, both cushioning properties and wear resistance can be achieved at a sufficiently high level.
That is, when the ratio of the cross-sectional area of the rubber hull to the cross-sectional area of the foam is in the range of 0/100 to 14/86, the wear volume of the rubber hull is insufficient, and the required wear resistance cannot be exhibited. On the other hand, in the range of 86/14 to 100/0, the volume of the foam becomes too small to provide sufficient cushioning properties for the foam.

1 and 2 are respectively a side view and a cross-sectional rear view showing a main part of a wheel-in motor vehicle to which a tire and a wheel system according to the present invention are applied.
This small, lightweight single-seat vehicle has a steering wheel 1 and a vehicle body provided with a step 2 on which a single driver rides in a standing position, and a pair of wheel-in-motor wheels mounted on the left and right sides of the step 2 4, wherein each wheel 4 is connected to a step via a motor 6 housed within the inner diameter of the wheel 5.

  Here, in the vehicle shown in FIG. 2, in order to increase the stability of the vehicle, one auxiliary wheel 7 is provided at the center in the width direction of the rear end portion of step 2 in such a manner that the direction can be changed. This is different from that shown in FIG.

The tire according to the present invention used for such a vehicle has an apparent specific gravity of 0.78 to 5.4 mN in the rubber outer shell 11 as shown in FIG. / Cm ³ , and the closed-cell foam 12 having a foaming rate of 1275 to 100% is accommodated and disposed, and the outer diameter D, directly the outer diameter of the rubber outer skin is 120 to 450 mm, and the contact width W is 50 to 100 mm. It will be.

Note that the tire 13 shown in this figure has a relatively large outer diameter, and is necessary to support the load between the rubber outer skin 11 and the foam 12 in a state of being mounted around the wheel rim 14. When the predetermined internal pressure is filled, the distance H between the rubber outer surface and the wheel rim surface on the equatorial plane E of the tire 13 is the distance d between the inner surface of the rubber outer surface and the foam surface. The ratio (d / H) to the tire is a value in the range of more than 0 to 0.2, but the tire 13 has a small diameter in the range of 120 to 250 mm and a flatness in the range of 20 to 50%. Then, as shown in the same cross-sectional view in FIG. 4, it becomes difficult to secure a space for filling the internal pressure between the rubber outer skin 11 and the foam 12 in relation to the inner diameter dimension of the wheel 5. The inner surface of the rubber skin on the tire equatorial plane E And 0 the distance d between the foam surface, the distance d, and 0 the ratio of distance H discussed above.
On the other hand, it is a matter of course that a tire having a large diameter exceeding 250 mm in outer diameter can also be of a type that does not fill the internal pressure as shown in FIG.

  3 and 4, the foam 12 accommodated in the rubber outer skin 11 is exposed on the inner peripheral surface of the tire 13, but the foam 12 is shown in FIGS. 5 (a) and 5 (b). As shown, it can also be surrounded by the rubber outer skin 11 over the entire circumference in the cross section, and according to this, the tire 13 can be attached to the wheel rim with the rubber outer skin 11 without the need for bead core reinforcement such as a bead core. The foam 12 can be easily fixed or fixed, and the shrinkage deformation of the foam 12 due to the external leakage of the gas in the foam can be advantageously suppressed.

  Here, in particular, in manufacturing the tire of the latter structure, when foam material is injected into an unvulcanized or vulcanized rubber shell and is then freely foamed to form foam 12. Since it is difficult to give the foam 12 the required shape, dimensions, etc., and to control the apparent specific gravity of the foam 12 as expected, The foam 12 is preferably accommodated in an unvulcanized rubber shell, and then the rubber shell is preferably vulcanized. In this case, for example, the foam material is subjected to a foaming reaction in a closed high-pressure vulcanizing press by a so-called filling method, and then immediately after forming the foamed foam at the time of unloading, it is put into a mold having a predetermined shape. It is preferable to form the required foam 12 through a process of performing secondary vulcanization.

  Further, in the type of tire 13 filled with the internal pressure, it is preferable that the outer contour shape of the rubber outer skin 11 in the illustrated cross section, in particular, the contour shape of the ground contact surface is a toroidal curve shape. For the unfilled type of tire 13, the same outer contour shape is appropriately selected as long as the required contact width W can be secured, regardless of the toroidal curve shape, and other low flat shapes or other shapes that are close to linear. can do.

  Here, for example, in the case of a tire having a tire outer diameter of 120 to 250 mm and a flatness ratio of 20 to 50% and not filled with internal pressure, the case shown in FIG. 4 and the case shown in FIG. In other words, regardless of whether the foam 12 is exposed on the inner peripheral surface of the tire 13, the ratio of the rubber skin cross-sectional area to the foam cross-sectional area in the cross-section in the width direction of the wheel 4 is 15 A range of / 85 to 85/15 is preferable.

  Further, in order to effectively prevent the tire as described above from slipping on the wheel rim 14 and coming off from the wheel rim 14, the rubber outer skin 11 particularly has a skeleton reinforcement corresponding to a carcass, a bead core or the like. Regardless of whether or not the tire 13 is of a type that fills the internal pressure when it has no members, at least one of the rubber outer skin 11 and the foam 12 is attached to the peripheral surface of the rim 14 by vulcanization or the like. , Chemical or physical fixing, and a diameter expansion constraining layer made of a non-extensible or low-extensible cord such as a steel cord or an aramid fiber cord in the contact portion of the tire 13 with the rim 14 At least one of arranging and preventing the deformation of the contact portion and providing the wheel 5 with a convex portion that prevents rim disengagement and rim slip It is preferable that the measures.

  One wheel system according to the present invention using such a tire has one of the above-described tires 13 having an inner diameter, more specifically, a rim inner diameter R as shown in FIGS. Is mounted around a rim 14 of a predetermined wheel 5 having a range of 80 to 400 mm to form a wheel 4, and each of the pair of wheels 4 is step 2 via a motor 6 accommodated within the inner diameter of the rim 14. In this case, the motor 6 is attached to the step 2 side together with a control circuit, a battery, and the like, and the output shaft of the motor 6 is connected to the disk 16 of the wheel 5.

  Therefore, based on the operation of the motor 6, the wheel 4 can be driven to rotate in a required manner, and can be accelerated / decelerated and stopped.

Under such a system, the tire 13 on the wheel rim can be either an internal pressure filling type or an internal pressure non-filling type as shown in FIGS.
In other words, the tire 13 of the wheel 4 has a distance d between the inner surface of the rubber hull and the surface of the foam on the equatorial plane E of the tire on the rim. The ratio (d / H) to the distance H between them can be any one in the range of 0 to 0.2.

  Further, in the same manner as described above, the other wheel system has a pair of wheels 4 each having a tire 13 mounted around the rim 14 of the wheel 5 having a rim inner diameter R of 80 to 400 mm. 4 and 5, the distance d between the inner surface of the rubber skin and the foam surface on the tire equatorial plane E is connected to each side portion of Step 2 via the motor 6 accommodated in the interior. As shown in the internal pressure non-filled tire shown in (b), 0 is set, so that the ratio (d / H) of the distance d to the distance H between the inner surface of the rubber skin and the wheel rim surface is set to 0. The ratio of the rubber shell cross-sectional area to the foam cross-sectional area in the cross-section in the width direction of the wheel 4 is in the range of 15/85 to 8/15 as described above.

  While manufacturing each of the wheel for wheel-in-motor vehicles, and the Example tire and comparative example tire which have the composition shown in Table 1, in the state which combined them into the wheel, the wear durability of the tire, the cushioning property and When the weather resistance was determined, the results shown in Table 2 were obtained.

Here, the wear durability is determined by measuring the wear amount of the rubber outer skin using a Lambourne wear tester (slip rate 5%), and evaluating the wear amount by index evaluation using the comparative tire 1 as a control.
The cushioning property is measured by measuring the deformation amount of the tire (protrusion depth of the protrusion) when a projection having a hemispherical shape with a tip of 10 ^φ is pressed against the tire with a force of 292N (40 kgf). Obtained by evaluating the index of Comparative Example Tire 1 as a control,
And durability was calculated | required by inspecting the presence or absence of the generation | occurrence | production of a surface crack after leaving outside for one month.
It should be noted that the larger the index value in Table 2, the better the result.

  According to Tables 1 and 2, it can be seen that the example tire 1 can greatly improve the cushioning property based on the filling of the foam, which is particularly remarkable in the example tire 2 that is also filled with air. Karu.

  On the other hand, although the comparative example tire 2 has improved cushioning properties under the action of the foam, the wear durability and weather resistance are greatly reduced, and the comparative example tire 3 has a low rubber hardness. It will be understood that the wear durability is lowered, and the comparative tire 4 cannot exhibit sufficient cushioning properties because the relative amount of foam is too small.

It is the side view and principal part cross-section rear view which show the single axle wheel in motor vehicle using this invention. It is a figure similar to FIG. 1 which shows the other vehicle using this invention. It is a principal part expanded sectional view of the width direction which shows the tire and wheel system concerning this invention. It is a figure similar to FIG. 3 which shows other embodiment of a tire about a half part. It is a figure similar to FIG. 3 which shows other embodiment of a tire about a half part. It is an approximate line sectional view showing each of an example tire and a comparative example tire in the state of a wheel.

Explanation of symbols

1 Handle 2 Step 4 Wheel 5 Wheel 6 Motor 11 Rubber outer shell 12 Foam 13 Tire 14 Rim 16 Disc D Outer diameter W Grounding width E Equatorial plane d, H Distance R Rim inner diameter

Claims (5)

A tire applied to a wheel-in-motor type wheel,
A closed cell foam having an apparent specific gravity of 0.78 to 5.4 mN / cm ³ and a foaming rate of 1275 to 100% is accommodated in the rubber shell, the outer diameter is 120 to 450 mm, and the grounding width is 50 to 100 mm. Tires for wheel-in motor vehicles.   The tire for a single-axle wheel-in-motor vehicle according to claim 1, wherein the outer diameter is 120 to 250 mm and the flatness ratio is 20 to 50%.   The tire according to claim 1 or 2 is mounted around a rim of a wheel having an inner diameter of 80 to 400 mm to form a wheel, and each of the pair of wheels is each side of a vehicle body step of a wheel-in motor vehicle. A wheel system using a tire for a wheel-in-motor vehicle, which is connected to the part via a motor housed within the inner diameter of the wheel.   The ratio (d / H) of the distance d between the inner surface of the rubber hull and the foam surface to the distance H between the inner surface of the rubber hull and the wheel rim surface (d / H) on the equator plane of the tire is 0 to 0. A wheel system using a tire for a wheel-in motor vehicle according to claim 3, wherein the wheel system is a wheel system. The tire according to claim 2 is mounted around a rim of a wheel having an inner diameter of 80 to 400 mm to form a wheel, and each pair of wheels is provided on each side of a vehicle body step of a wheel-in motor vehicle. The inner surface of the rubber shell and the surface of the wheel rim at a distance d between the inner surface of the rubber outer shell and the foam surface on the equator of the tire. The ratio (d / H) with respect to the distance H between the two is 0, and the ratio of the rubber shell cross-sectional area to the foam cross-sectional area in the cross-section in the width direction of the wheel is in the range of 15/85 to 85/15 A wheel system using tires for wheel-in motor vehicles.

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