JP2007118873A - Pneumatic tire, tire and rim wheel assembly, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly enable the control of the ground contact state of a pneumatic tire. <P>SOLUTION: In the pneumatic tire, an auxiliary air chamber 26 is formed in both shoulder ribs 28 outside a belt. By changing the pressure of the auxiliary air chamber 26, the ground contact state, in other words, the ground contact pressure, the ground contact length and the ground contact shape can be changed, or the pseudo camber angle can be changed. The auxiliary air chamber 26 is arranged inside a tread 16 outside the belt, and the width AQ of the auxiliary air chamber 26 is set in a range of ≥5% and <50% of the ground contact width TW. Thus, the volume of the pneumatic tire is relatively and sufficiently small with respect to a tire air chamber 11 formed between the pneumatic tire 10 and a rim wheel 12, The internal pressure (the volume) of the auxiliary air chamber 26 can be rapidly changed according to the state of a vehicle even in a traveling mode by taking out/putting in a gas of the small amount. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pneumatic tire, a tire / rim wheel assembly, and a vehicle, and more particularly, to a pneumatic tire, a tire / rim wheel assembly, and a vehicle capable of quickly controlling a ground contact state during traveling.

Generally, since a pneumatic tire is used in a state where the shape is fixed, it is difficult to change the tire performance in accordance with a change in road surface condition.
Therefore, for example, Patent Documents 1 and 2 disclose systems that improve various performances by controlling the pressure in the tire chamber.
JP 2005-189044 A. JP 2005-198363 A.

In the above conventional system, it is possible to change the ground contact state by changing the pressure in the tire chamber, but the volume of the tire chamber is large, and the tire air volume is changed according to the road surface condition and the running condition that change every moment. It is difficult to quickly control the pressure in the room.
The present invention has been made to solve the above-described problems, and an object thereof is to provide a pneumatic tire, a tire / rim wheel assembly, and a vehicle capable of quickly controlling a ground contact state.

  The invention according to claim 1 includes a carcass straddling a pair of bead cores, a belt disposed on the outer side in the tire radial direction of the carcass, a tread rubber layer disposed on the outer side in the tire radial direction of the belt, and the tread. A sub air chamber provided on at least one side of the tire layer in the tire width direction of the tire equatorial plane of the rubber layer and the sub air chamber are connected to each other to communicate gas between the sub air chamber and the outside of the tire to the sub air chamber. A communication passage that can be taken in and out, and when the width of the auxiliary air chamber measured along the tread when viewed in a cross section along the tire rotation axis is AW, and the ground contact width of the tread rubber layer is TW In addition, the width AW is characterized by being set within a range of 5% or more and less than 50% with respect to the ground contact width TW.

Next, the operation of the pneumatic tire according to claim 1 will be described.
In the pneumatic tire according to the first aspect, since the communication passage is connected to the sub air chamber provided in the tread rubber layer, the internal pressure in the sub air chamber can be changed from the outside of the tire.

  The auxiliary air chamber is provided at least on one side of the tire equatorial plane in the tire width direction. For example, by increasing the pressure of the gas in the auxiliary air chamber provided on one side of the tire equatorial plane in the tire width direction, the surface of the tread rubber layer where the auxiliary air chamber is provided expands outward in the tire radial direction. The tire diameter on the side where the auxiliary air chamber is provided can be increased in comparison with the side where the auxiliary air chamber is not provided. Thereby, the ground contact state (ground pressure, ground contact length, ground contact shape) of the tire can be controlled, and for example, the ground contact shape that is symmetrical with respect to the tire equator plane can be made asymmetric left and right.

  Also, when the tire diameter on one side and the other side of the tire equatorial plane changes, the pneumatic tire has a camber angle so as to incline to the side opposite to the side where the auxiliary air chamber is provided. The same effect can be achieved (a so-called pseudo camber angle can be provided).

  The auxiliary air chamber is disposed inside the tread rubber layer, and the width AW of the auxiliary air chamber is set within a range of 5% to less than 50% with respect to the ground contact width TW. The volume is relatively small (for example, 3.0% or less) with respect to the tire chamber formed between the two. For this reason, the internal pressure (volume) of the auxiliary air chamber can be quickly changed by taking in and out a small amount of gas.

When drainage grooves are formed in the tread rubber layer, the outermost portion of the auxiliary air chamber in the tire radial direction is positioned in the tire radial direction from the groove bottom so that the auxiliary air chamber is not exposed to the tread at the end of wear. It is preferable to be located inside.
Further, the auxiliary air chamber may be provided on both sides of the tire equator plane.

Here, if the width AW of the auxiliary air chamber is less than 5% of the ground contact width TW, the width of the auxiliary air chamber is too narrow, and the change of the ground contact state and the pseudo camber angle cannot be performed.
On the other hand, if the width AW of the auxiliary air chamber is 50% or more with respect to the ground contact width TW, the auxiliary air chamber cannot be disposed on both sides of the tire equatorial plane. In addition, if the auxiliary air chamber is too wide, the tread rubber width on both sides of the auxiliary air chamber (the width of the rubber portion where there is no cavity) is narrowed. A peeling failure tends to occur at the interface between the belt and the tread rubber layer toward the buttress portion, and the tire durability tends to be lowered.
The lower limit value of the width AW of the auxiliary air chamber is preferably 15% or more with respect to the ground width TW, and the upper limit value of the width AW of the auxiliary air chamber is preferably 25% or less with respect to the ground width TW.

  The contact width of the tread rubber layer here means that the pneumatic tire is mounted on a standard rim specified in JATMA YEAR BOOK (2005 edition, Japan Automobile Tire Association Standard), and the applicable size / ply in JATMA YEAR BOOK This is when the maximum load capacity is loaded with 100% internal pressure of the air pressure (maximum air pressure) corresponding to the maximum load capacity in the rating (bold load in the internal pressure-load capacity correspondence table). When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, the respective standards are followed.

  According to a second aspect of the present invention, in the pneumatic tire according to the first aspect, a position separated from the ground contact end toward the tire equatorial plane by a distance corresponding to ¼ of the ground contact width TW In this case, the auxiliary air chamber is arranged on the outer side in the tire width direction than the ¼ point.

Next, the operation of the pneumatic tire according to claim 2 will be described.
By arranging the auxiliary air chamber closer to the grounding end (outermost part of the grounding width in the tire axial direction), that is, outside the 1/4 point, the grounding shape can be easily changed, and the pseudo camber angle It is preferable because it is easy to attach.

  According to a third aspect of the present invention, in the pneumatic tire according to the first or second aspect, the tread rubber layer has a plurality of circumferential grooves extending along a tire circumferential direction. The auxiliary air chamber is characterized in that it is arranged on the outer side in the tire width direction than the circumferential groove on the outermost side in the tire width direction.

Next, the operation of the pneumatic tire according to claim 3 will be described.
In the case where a plurality of circumferential grooves extending along the tire circumferential direction are formed in the tread rubber layer, the auxiliary air chamber is disposed on the outer side in the tire width direction than the outermost circumferential groove in the tire width direction. As in item 2, it is preferable because the ground contact shape can be easily changed and the pseudo camber angle can be easily set.

  According to a fourth aspect of the present invention, in the pneumatic tire according to any one of the first to third aspects, the auxiliary air chamber is formed in an annular shape continuously in the tire circumferential direction. It is characterized by.

Next, the operation of the pneumatic tire according to claim 4 will be described.
If the internal pressure of the auxiliary air chamber is increased when the auxiliary air chamber is provided intermittently in the tire circumferential direction, the tread surface may be uneven in the tire circumferential direction. Therefore, the auxiliary air chamber is preferably formed in an annular shape continuously in the tire circumferential direction.

  According to a fifth aspect of the present invention, in the pneumatic tire according to any one of the first to fourth aspects, the thickness of the tread rubber layer is TG, and the tread surface from the tire equatorial plane to the auxiliary air chamber is The distance measured along EW, the width measured along the tread of the auxiliary air chamber, AW, the maximum height measured along the tire radial direction of the auxiliary air chamber as H, and measured along the tread. When the width of the belt is BW, EW <BW / 2 <EW + AW, EW <TW / 2 <EW + AW, and 0.1 <H / TG <0.5 are satisfied. It is a feature.

Next, the operation of the pneumatic tire according to claim 5 will be described.
Problems in the case of BW / 2 ≦ EW or EW + AW ≦ BW / 2 will be described below.
If there is a sub-air chamber (cavity) at the belt end position, it suppresses the heat generation of rubber around the belt end (= no rubber that generates heat), resulting in improved rolling resistance. Since there is no overlap between the end position and the auxiliary air chamber, the rolling resistance cannot be improved.

Problems in the case of TW / 2 ≦ EW or EW + AW ≦ TW / 2 will be described below.
When there is a secondary air chamber (cavity) at the contact end (directly below) in the tire width direction of the contact area, the contact pressure at the contact end decreases, the contact area increases, and the contact pressure distribution tends to be uniform However, in this case, since there is no auxiliary air chamber at the contact end, the contact pressure at the contact end becomes as high as that of the conventional tire (no auxiliary air chamber), and the contact area is expanded and the contact pressure is increased. Unable to achieve uniform distribution.

Problems in the case of H / TG ≦ 0.1 will be described below.
In this case, since the height of the auxiliary air chamber is too low, the auxiliary air chamber is crushed when the load contacts the ground, and the rubber above and below the auxiliary air chamber closely adheres to each other. Ground pressure distribution. As a result, the rolling resistance cannot be improved and the ground contact area cannot be increased.

Problems in the case of 0.5 ≦ H / TG will be described below.
In this case, since the height of the auxiliary air chamber is too high, the tread rubber gauge on the auxiliary air chamber becomes relatively thin, so that the deformation of the tread rubber on the auxiliary air chamber becomes too large at the time of grounding. As a result, the tread rubber on the auxiliary air chamber is destroyed at an early stage, and the tire durability is lowered.

  According to a sixth aspect of the present invention, in the pneumatic tire according to any one of the first to fifth aspects, the communication path opens to a tire inner surface side, and the auxiliary air is formed in the opening. A connection member for connecting a pipe for taking gas into and out of the chamber is attached.

Next, the operation of the pneumatic tire according to claim 6 will be described.
Since the connecting member is provided on the inner surface of the tire, for example, by connecting a pipe connected to the outside of the rim wheel to the connecting member, gas can be easily taken in and out (pressure adjustment) to the auxiliary air chamber via this pipe. Can be done.

  According to a seventh aspect of the present invention, in the pneumatic tire according to any one of the first to fifth aspects, the communication path opens to the tire inner surface side, and the communication path includes a first An on-off valve is attached.

Next, the operation of the pneumatic tire according to claim 7 will be described.
For example, when the pressure in the auxiliary air chamber is set in advance higher than that in the tire air chamber, and the pressure in the auxiliary air chamber is desired to be reduced midway, the first on-off valve is opened. As a result, part of the gas in the auxiliary air chamber is discharged into the tire air chamber, and the pressure in the auxiliary air chamber can be reduced.

  On the other hand, when the pressure in the auxiliary air chamber is set lower than that in the tire air chamber in advance and the pressure in the auxiliary air chamber is to be increased in the middle, the first on-off valve is opened. Thereby, a part of gas in the tire air chamber is discharged into the sub air chamber, and the pressure in the sub air chamber can be increased.

  In addition, since it is difficult to directly operate the first on-off valve inside the tire from the outside of the tire and the rim wheel, the first on-off valve is a solenoid valve that can be remotely operated. It is preferable to take measures such as passing the wiring through the rim wheel and pulling it out of the rim wheel.

  According to an eighth aspect of the present invention, the pneumatic tire according to any one of the first to seventh aspects further includes a pressure sensor that detects an internal pressure of the auxiliary air chamber.

Next, the operation of the pneumatic tire according to claim 8 will be described.
In the pneumatic tire according to claim 8, the internal pressure of the auxiliary air chamber can be detected by a pressure sensor.

  A ninth aspect of the present invention is the pneumatic tire according to any one of the first to eighth aspects, further comprising a transmission unit that wirelessly transmits pressure detection data detected by the pressure sensor. It is said.

Next, the operation of the pneumatic tire according to claim 9 will be described.
In the pneumatic tire according to claim 9, the pressure detection data detected by the pressure sensor can be wirelessly transmitted by the transmission means, and the transmitted pressure detection data is received by the tire and the receiver disposed outside the rim wheel. Can be received. Note that when pressure detection data is transmitted using wiring without using a wireless device, a slip ring or the like is separately required between the rim wheel and the vehicle body, and wiring is complicated.

  A tire / rim wheel assembly according to a tenth aspect is characterized in that the pneumatic tire according to any one of the first to ninth aspects is assembled to a rim wheel.

Next, the operation of the tire / rim wheel assembly according to claim 10 will be described.
Since the pneumatic tire according to any one of claims 1 to 9 is assembled to the rim wheel, the tire / rim wheel assembly according to claim 10 is filled with gas in the tire chamber. So, it can be used on a vehicle. Other operations are the same as those of the first to ninth aspects, and will not be described.

  According to an eleventh aspect of the present invention, in the tire / rim wheel assembly according to the tenth aspect, a second on-off valve is attached to the rim wheel, and the second on-off valve has one connection port. It arrange | positions on the rim wheel outer side, and the other connection port is connected to the 1st piping connected with the said auxiliary air chamber, It is characterized by the above-mentioned.

Next, the operation of the tire / rim wheel assembly according to claim 11 will be described.
In order to increase the pressure by filling the sub-air chamber with gas, for example, by connecting a high-pressure hose from an air compressor or a tank filled with gas at high pressure to the second on-off valve, Gas can be supplied to the auxiliary air chamber via the valve and the first pipe. In order to reduce the internal pressure of the auxiliary air chamber, the second on-off valve may be opened to discharge the gas in the auxiliary air chamber to the atmosphere.

  The invention according to claim 12 is the tire / rim wheel assembly according to claim 10, wherein the first gas tank is provided in the rim wheel and is filled with a gas to be supplied to the auxiliary air chamber, It has the 2nd piping which connects a subair chamber and the 1st gas tank, It is characterized by the above-mentioned.

Next, the operation of the tire / rim wheel assembly according to claim 12 will be described.
In the tire / rim wheel assembly according to the twelfth aspect of the present invention, for example, the first gas tank is previously filled with gas at a high pressure. By supplying the gas in the first gas tank to the sub air chamber via the second pipe, the pressure in the sub air chamber can be increased.

  According to a thirteenth aspect of the present invention, in the tire / rim wheel assembly according to the twelfth aspect of the present invention, the first gas tank is provided in a wheel disc portion.

Next, the operation of the tire / rim wheel assembly according to claim 13 will be described.
In the tire / rim wheel assembly according to the thirteenth aspect, since the first gas tank is provided in the wheel disc portion, the inner diameter of the rim does not become smaller than the conventional one.

  According to a fourteenth aspect of the present invention, in the tire / rim wheel assembly according to the twelfth aspect of the present invention, the first gas tank does not have a diameter smaller than the inner diameter of the drop portion on the side of the drop portion of the rim. It is characterized by being formed.

Next, the operation of the tire / rim wheel assembly according to claim 14 will be described.
In the tire / rim wheel assembly according to claim 14, since the first gas tank is formed on the side of the drop portion of the rim so as not to be smaller than the inner diameter of the drop portion, the inner diameter of the rim is conventional. There is no small diameter in comparison.

  A fifteenth aspect of the present invention is the tire / rim wheel assembly according to any one of the twelfth to fourteenth aspects, wherein the rim wheel includes a first gas tank and a sub air chamber. It has the 1st pressure change means which changes the internal pressure of the above-mentioned sub air chamber by performing gas movement between.

Next, the operation of the tire / rim wheel assembly according to claim 15 will be described.
When changing the internal pressure of the auxiliary air chamber, the gas is moved between the first gas tank and the auxiliary air chamber using the first pressure changing means. For example, if the gas in the first gas tank is moved to the sub air chamber, the pressure in the sub air chamber can be increased. Further, if the gas in the auxiliary air chamber is moved to the first gas tank, the pressure in the auxiliary air chamber can be reduced.

  According to a sixteenth aspect of the present invention, in the tire / rim wheel assembly according to the tenth aspect of the present invention, a second gas pressure is changed between the atmosphere and the auxiliary air chamber by changing the internal pressure of the auxiliary air chamber. It has a pressure change means.

Next, the operation of the tire / rim wheel assembly according to the sixteenth aspect will be described.
When the internal pressure of the auxiliary air chamber is changed, the gas is moved between the auxiliary air chamber and the atmosphere using the second pressure changing means. For example, if the atmospheric gas (air) is moved to the auxiliary air chamber, the pressure of the auxiliary air chamber can be increased. Further, if the gas in the auxiliary air chamber is discharged (moved) to the atmosphere, the pressure in the auxiliary air chamber can be reduced.

  The invention according to claim 17 is the tire / rim wheel assembly according to claim 10, wherein the second gas tank is provided on an outer periphery of the rim wheel and is filled with a gas to be supplied to the auxiliary air chamber. And a third pipe that connects the sub-air chamber and the second gas tank, and an on-off valve that is connected to at least the third pipe.

Next, the operation of the tire / rim wheel assembly according to claim 17 will be described.
In the tire / rim wheel assembly according to the seventeenth aspect, for example, the second gas tank is previously filled with gas at a high pressure. By opening the on-off valve and supplying the gas in the second gas tank to the sub air chamber via the third pipe, the pressure in the sub air chamber can be increased.

According to an eighteenth aspect of the present invention, in the tire / rim wheel assembly according to the seventeenth aspect, the second gas tank is an annular tube made of an elastic body.
In the tire / rim wheel assembly according to the eighteenth aspect, the annular tube made of an elastic body can be filled with gas.

  According to a nineteenth aspect of the present invention, in the tire / rim wheel assembly according to the tenth aspect, the pneumatic tire is provided with the auxiliary air chambers on both sides of a tread rubber layer with a tire equatorial plane interposed therebetween, and the rim The wheel is provided with a double-acting cylinder driven by an actuator, one of the sub air chambers is connected to one cylinder chamber of the double acting cylinder, and the other sub air chamber is connected to the other cylinder chamber of the double acting cylinder. It is characterized by being connected.

Next, the operation of the tire / rim wheel assembly according to claim 19 will be described.
In the tire and rim wheel assembly according to claim 19, for example, by moving one of the cylinder rods of a double-acting cylinder with an actuator, the pressure in the auxiliary air chamber connected to the cylinder chamber on one side increases, and the other side The pressure in the auxiliary air chamber connected to the cylinder chamber can be reduced. If the cylinder rod is moved in the opposite direction, the pressure in the sub air chamber connected to the one cylinder chamber can be reduced, and the pressure in the sub air chamber connected to the other cylinder chamber can be increased.

A vehicle according to a twentieth aspect is characterized by mounting the tire / rim wheel assembly according to any one of the eleventh to nineteenth aspects.
Since the operation of the vehicle according to the twentieth aspect is the same as that of the eleventh to nineteenth aspects, the description is omitted.

  As described above, the pneumatic tire, the tire / rim wheel assembly, and the vehicle according to the present invention have the above-described configuration, so that the ground contact state can be quickly controlled. The braking and driving performance can be improved by changing the grounding state. In addition, the turning performance can be improved by changing the pseudo camber angle.

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a tire / rim wheel assembly 14 in which a pneumatic tire 10 is assembled to a rim wheel 12.
(Pneumatic tire structure)
As shown in FIG. 1, the pneumatic tire 10 of the present embodiment has a general structure except for an internal structure of a tread 16 described later, and includes a carcass 20 straddling a pair of bead cores 18. One or more belts 22 and a tread 16 are disposed on the radially outer side. The basic structure of the pneumatic tire 10 may be a radial structure or another structure such as a bias structure.
The tread 16 is formed with a plurality of circumferential grooves 24 (four in this embodiment) extending along the circumferential direction.

FIG. 2 shows a cross section when the tread 16 is developed into a flat plate shape.
A pair of sub-air chambers 26 having a hollow shape are formed inside the tread 16.
Here, when the width of the auxiliary air chamber 26 is AW and the grounding width of the tread 16 is TW, the width AW of the auxiliary air chamber 26 is set within a range of 5% or more and less than 50% with respect to the grounding width TW. Further, the lower limit value of the width AW is preferably 15% or more, and the upper limit value of the width AW is preferably 25% or less.

Further, when the position separated from the ground contact edge 16E toward the tire equatorial plane CL by a distance corresponding to 1/4 of the ground contact width TW is set to 1/4 point P, the auxiliary air chamber 26 is from 1/4 point P. Also, it is preferable to arrange the outer side in the tire width direction.
In the present embodiment, the auxiliary air chamber 26 is formed inside the shoulder rib 28 outside the outer circumferential circumferential groove 24 in the tire radial direction. The auxiliary air chamber 26 is continuous in the tire circumferential direction, and the shape viewed from the tire axial direction is annular.

  Further, the thickness of the tread 16 (belt outermost surface to tread surface) is TG, the distance measured along the tread surface from the tire equator surface CL to the sub air chamber 26 is EW, and the width dimension is measured along the tread surface of the sub air chamber 26. EW <BW / 2 <EW + AW where AW is the maximum height dimension measured along the tire radial direction of the auxiliary air chamber 26 and H is the width of the belt 22 measured along the tread surface. , EW <TW / 2 <EW + AW, and 0.1 <H / TG <0.5 are preferably satisfied.

As shown in FIG. 1, a communication hole 30 is formed in the pneumatic tire 10 from the auxiliary air chamber 26 toward the tire inner peripheral surface.
A tire connection member (connector) 34 for connecting a pipe 32 is fixed to the communication hole 30 on the tire inner peripheral surface side, and one end of the pipe 32 is connected to the tire connection member 34. ing. Since the pneumatic tire 10 is elastically deformed during traveling, the pipe 32 is preferably formed of a material such as rubber or synthetic resin that can be elastically deformed.

(Rim wheel structure)
The rim wheel 12 includes a valve (not shown in FIG. 1) for filling the tire air chamber with a gas such as air, and a rim for letting a gas such as air into and out of the right auxiliary air chamber 26. A connecting member 36 is attached. The other end of the pipe 32 is connected to the rim connection member 36.
Although not shown in FIG. 1, the tire connection member 34, the pipe 32, and the rim connection member 36 are also connected to the left side auxiliary air chamber 26, and the right side auxiliary air chamber 26, The left auxiliary air chamber 26 can supply gas independently.

  As shown in FIGS. 1 and 3, a pipe 40 is connected to the rim connection member 36. As shown in FIG. 3, the pipe 40 connected to the rim connection member 36 is connected to a pipe 42 from an air compressor 38 provided in the vehicle via a rotation seal 44. Thereby, air can be supplied to the auxiliary air chamber 26 even while the tire is rotating.

  In addition, an electrically controlled on / off valve 46, a pressure sensor 50, and an electrically controlled pressure release valve 52 are provided in the middle of the pipe 42, and an air compressor 38, an on / off valve 46, a pressure sensor 50, The pressure relief valve 52 is connected to the controller 54.

(Function)
Next, the operation of this embodiment will be described.
In the tire / rim wheel assembly 14 of the present embodiment, the pressure in the auxiliary air chamber 26 can be changed, thereby changing the grounding state (the grounding pressure, the grounding length and the grounding shape are changed, or the pseudo camber angle is changed. I can do it.

In order to increase the pressure in the auxiliary air chamber 26, the air compressor 38 is operated and the open / close valve 46 is opened. Increasing the auxiliary air chamber 26 to a desired internal pressure (for example, determined by the running state) can be realized by controlling the opening / closing of the opening / closing valve 46 while detecting the pressure with the pressure sensor 50.
On the other hand, in order to reduce the pressure in the auxiliary air chamber 26 to a desired internal pressure, the open / close valve 46 is closed, the pressure release valve 52 is opened while measuring the pressure, and the gas in the auxiliary air chamber is discharged to the atmosphere. Thereby, the pressure of the sub air chamber 26 can be reduced to a desired value.

Note that the pressure in the auxiliary air chamber 26 may be changed based on the state of the vehicle, or may be arbitrarily changed by the driver.
For example, when the pressure of the auxiliary air chamber 26 provided on one side of the tire equatorial plane CL in the tire width direction (for example, the right side of the drawing) is increased, the tread surface of the portion where the auxiliary air chamber 26 is provided becomes the tire diameter. Inflated to the outside in the direction, the tire diameter of the portion where the right side air chamber 26 is provided is increased, and the ground contact shape that is symmetrical with respect to the tire equatorial plane CL is left-right asymmetric (in this embodiment) The contact length on the right side of the tire equatorial plane CL becomes shorter.

  Further, since the tire diameter on the right side of the tire equatorial plane CL increases, the tire / rim wheel assembly 14 can perform the same operation as when the camber angle is provided so as to incline to the left side (so-called so-called). , Pseudo camber angle can be given.).

  The auxiliary air chamber 26 of the present embodiment is disposed inside the tread 16 outside the belt, and the width AW of the auxiliary air chamber 26 is set within a range of 5% or more and less than 50% with respect to the ground contact width TW. Therefore, the volume of the tire air chamber formed between the pneumatic tire 10 and the rim wheel 12 is relatively small, and a small amount of gas is taken in and out so that the vehicle can be moved even during traveling. The internal pressure (volume) of the auxiliary air chamber 26 can be quickly changed according to the state or the like.

  Further, since EW <BW / 2 <EW + AW and the auxiliary air chamber 26 is arranged on the belt end, heat generation of rubber around the belt end is suppressed (= for the auxiliary air chamber 26 which is a cavity, As a result, the rolling resistance can be improved.

  Moreover, since EW <TW / 2 <EW + AW and the auxiliary air chamber 26 which is a cavity is disposed under the grounding end 16E, the grounding pressure near the grounding end can be reduced and the grounding area is increased. It is possible to make the contact pressure distribution uniform.

  Further, since 0.1 <H / TG <0.5, the auxiliary air chamber 26 is not crushed at the time of ground contact, and the durability of the tread 16 can be ensured. Is definitely obtained.

When BW / 2 ≦ EW or EW + AW ≦ BW / 2, there is no overlap between the belt end position and the auxiliary air chamber 26, so that the rolling resistance cannot be improved.
When TW / 2 ≦ EW or EW + AW ≦ TW / 2, there is no auxiliary air chamber 26 immediately below the contact end, so that the contact pressure at the contact end 16E becomes as high as that of the conventional tire (no auxiliary air chamber). , Expansion of the contact area and uniform distribution of contact pressure cannot be achieved.

When H / TG ≦ 0.1, the height of the auxiliary air chamber 26 is too low, the auxiliary air chamber 26 is crushed when the load is grounded, and the upper and lower rubbers are in close contact with each other. Heat generation, grounding shape, and grounding pressure distribution. As a result, the rolling resistance cannot be improved and the ground contact area cannot be increased.
When 0.5 ≦ H / TG, the height of the auxiliary air chamber 26 is too high, and the tread rubber gauge on the auxiliary air chamber becomes relatively thin. Too much. As a result, the tread rubber on the auxiliary air chamber is destroyed at an early stage, and the tire durability is lowered.

Here, when the width AW of the auxiliary air chamber 26 is less than 5% of the ground contact width TW, the width AW of the auxiliary air chamber 26 is too narrow, and the grounding state and the pseudo camber angle cannot be changed.
On the other hand, if the width AW of the auxiliary air chamber 26 is 50% or more with respect to the ground contact width TW, the auxiliary air chamber 26 cannot be disposed on both sides of the tire equatorial plane CL. In addition, when the width AW of the auxiliary air chamber 26 is too wide, the tread rubber width on both sides of the auxiliary air chamber 26 (the width of the rubber portion where there is no cavity portion) is narrowed. A peeling failure tends to occur at the interface between the belt 22 and the tread 16 from both ends of the auxiliary air chamber toward the tire buttress portion, and the tire durability is likely to be lowered.
[Second Embodiment]

  Next, a second embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 4A, in the rim wheel 12 of the present embodiment, a gas tank 56 having a hollow shape is formed in the disk portion 12A. Note that an air valve (with a valve core) (not shown) is attached to the gas tank 56 in order to fill the tank with gas from the outside of the rim wheel.

A pressure control valve 58 is attached to the gas tank 56, and the other end of the pipe 32 is connected to the pressure control valve 58 in this embodiment.
The pressure control valve 58 includes an on-off valve and a pressure sensor, and the on-off valve and the pressure sensor are connected to a controller 54 (not shown in FIG. 4) via wiring (not shown), a slip ring provided in the vehicle, and the like. Has been.

  Further, as shown in FIG. 4B, in the tire / rim wheel assembly 14 of the present embodiment, the tire connecting member 34 and the pipe 32 are connected at a position different from the portion shown in FIG. The pipe 32 is connected to an on-off valve 59 provided on the rim wheel 12. The on-off valve 59 is connected to the controller 54.

In the present embodiment, the gas tank 56 is filled with gas at a higher pressure than the tire air chamber 11.
When increasing the pressure in the auxiliary air chamber 26, the on-off valve of the pressure control valve 58 is opened. Thereby, the gas in a gas tank moves to the sub air chamber 26, and the pressure of the sub air chamber 26 can be raised. On the other hand, when the pressure in the auxiliary air chamber 26 is decreased, the on-off valve 59 is opened. Thereby, the gas in a gas tank is discharged | emitted to air | atmosphere, and the pressure of the subair chamber 26 can be reduced.

The internal pressure of the auxiliary air chamber 26 is set to a desired value by controlling the open / close valve of the pressure control valve 58 or the open / close valve 59 while measuring the pressure on the auxiliary air chamber side with the pressure sensor of the pressure control valve 58. It can be set.
In the present embodiment, since the gas tank 56 is provided in the disk portion 12A, the brake device of the vehicle can be disposed inside the rim as usual without reducing the inner diameter of the rim.
Other functions and effects are the same as those of the first embodiment.

[Third Embodiment]
Next, a third embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
The tire / rim wheel assembly 14 of the present embodiment is a modification of the tire / rim wheel assembly 14 according to the second embodiment described above. As shown in FIG. A gas tank 60 is formed on the side of 12B in the form of an annular cavity that is continuous in the circumferential direction.

In the present embodiment, the pressure control valve 58 is attached to the gas tank 60. In addition, an air valve (not shown) is attached to the gas tank 60 in order to fill the tank with gas.
Similarly to the second embodiment, the tire / rim wheel assembly 14 of the third embodiment also fills the gas tank 60 with gas at a pressure higher than that of the tire air chamber 11, and the pressure control valve 58 and the opening / closing valve 59. (Not shown in FIG. 5), the pressure in the auxiliary air chamber can be adjusted.

In this embodiment, since the gas tank 60 is provided on the side of the well portion 12B, the brake device of the vehicle can be disposed inside the rim as usual without reducing the rim inner diameter.
Other functions and effects are the same as those of the second embodiment.

[Fourth Embodiment]
Next, a fourth embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
Unlike the second embodiment and the third embodiment, the rim wheel 12 of the present embodiment has a general structure.

In the tire / rim wheel assembly 14 of the present embodiment, an annular tube 62 made of an elastic body such as rubber is disposed in the tire chamber instead of the gas tank of the second and third embodiments.
In the present embodiment, the pipe 32 is connected to the tube 62 via the pressure control valve 58.

Note that an air valve 64 is attached to the tube 62 in order to fill the tube with gas, and an end of the air valve 64 protrudes toward the inner peripheral side of the rim wheel.
In the present embodiment, the tube 62 is filled with gas at a pressure higher than that of the tire air chamber 11, and the pressure in the auxiliary air chamber is adjusted by the pressure control valve 58 and the on-off valve 59 (not shown in FIG. 6). it can.
Other functions and effects are the same as those of the second and third embodiments described above.

[Fifth Embodiment]
Next, a fifth embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.

  As shown in FIG. 7, in the tire / rim wheel assembly 14 of the present embodiment, a gas tank 60 is formed integrally with the rim wheel 12. The rim wheel 12 is provided with an air supply / exhaust device 66 for moving gas between the auxiliary air chamber 26 and the gas tank 60.

The air supply / exhaust device 66 is composed of a small air compressor, a flow path switching valve, a pressure sensor, and the like. The gas supply / exhaust device 66 moves the gas in the gas tank to the sub-air chamber 26 or transfers the gas in the sub-air chamber to the gas tank 60. By moving, the pressure of the auxiliary air chamber 26 can be changed. The air supply / exhaust device 66 is connected to the controller 54 via a wiring (not shown) and a slip ring.
In addition, the effect at the time of changing the pressure of the sub air chamber 26 is the same as that of 1st Embodiment.

[Sixth Embodiment]
Next, a sixth embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. The present embodiment is a modification of the fifth embodiment described above, and the same reference numerals are given to the same components as those in the fifth embodiment, and the description thereof is omitted.

As shown in FIG. 8, the rim wheel 12 of the tire / rim wheel assembly 14 of this embodiment has a general structure, and an air supply / exhaust device 66 is attached to the rim wheel 12. In the present embodiment, the air supply / exhaust device 66 moves the gas between the sub air chamber 26 and the atmosphere, thereby changing the pressure of the sub air chamber 26.
In addition, the effect at the time of changing the pressure of the sub air chamber 26 is the same as that of 1st Embodiment.

[Seventh Embodiment]
Next, a seventh embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
In the sixth embodiment, the internal pressure of the auxiliary air chamber 26 is reduced by discharging the gas of the auxiliary air chamber 26 to the atmosphere. However, when the pressure of the auxiliary air chamber 26 is higher than that of the tire air chamber 11. The internal pressure of the auxiliary air chamber 26 can be reduced by discharging the gas in the auxiliary air chamber 26 to the tire air chamber 11.

In this case, as shown in FIG. 9, the internal pressure of the auxiliary air chamber 26 can be reduced by attaching an opening / closing valve 59 to the communication hole 30 and opening the opening / closing valve 59.
In addition, the effect at the time of changing the pressure of the sub air chamber 26 is the same as that of 1st Embodiment.

[Eighth Embodiment]
Next, an eighth embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
In the above-described embodiment, the gas previously filled in the gas tank or the air in the atmosphere is supplied to the sub air chamber 26. However, the gas in the tire air chamber 11 is supplied to the sub air chamber 26. You can also take.

In this case, as shown in FIG. 10, the pressure control valve 58 is attached to the communication hole 30, and when the pressure in the auxiliary air chamber 26 is increased, the opening / closing valve of the pressure control valve 58 is opened. On the other hand, when the pressure in the sub air chamber 26 is decreased, the gas in the sub air chamber may be discharged to the atmosphere.
In addition, the effect at the time of changing the pressure of the sub air chamber 26 is the same as that of 1st Embodiment.

[Ninth Embodiment]
Next, a ninth embodiment of the tire / rim wheel assembly of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
As shown in FIG. 11, in this embodiment, one auxiliary air chamber 26 is sandwiched between the tire equatorial plane and one cylinder chamber 68 </ b> R of the double rod double-acting cylinder 68 is sandwiched between the tire equatorial plane via the pipe 32. The other auxiliary air chamber 26 is connected to the other cylinder chamber 68 </ b> L of the double rod double acting cylinder 68 through the pipe 32.

The cylinder rod 70 of the double rod double acting cylinder 68 is movable by an electric actuator 72 controlled by a controller 54 (not shown in FIG. 11).
The double rod double acting cylinder 68 and the actuator 72 may be attached to the rim wheel 12 or to the vehicle.

  In the present embodiment, for example, by moving the cylinder rod 70 to the cylinder chamber 68R side by the actuator 72, the pressure in the cylinder chamber 68R can be increased and the pressure in the cylinder chamber 68L can be decreased. Further, by moving the cylinder rod 70 toward the cylinder chamber 68L, the pressure in the cylinder chamber 68L can be increased and the pressure in the cylinder chamber 68R can be decreased.

Note that the internal pressures of both the auxiliary air chambers 26 may be set in advance equal to the tire air chamber 11, or may be set higher or lower than the tire air chamber 11.
The actuator 72 is not limited to an electric type, and may be a pneumatic type or a hydraulic type.
In the present embodiment, the double rod double acting cylinder 68 is used to change the pressure balance of the auxiliary air chamber 26, but the above-described air supply / exhaust device 66 may be used instead of the double rod double acting cylinder 68.

[Other Embodiments]
In the above embodiment, the auxiliary air chamber 26 is formed in the shoulder rib 28 outside the outer circumferential circumferential groove 24 in the tire radial direction. The air chamber 26 may be formed.

Moreover, although the sub air chamber 26 of the said embodiment was an annular shape continuous in the tire circumferential direction, the sub air chamber 26 may be provided intermittently in the tire circumferential direction.
Further, when the tread 16 has a block pattern, the auxiliary air chamber 26 may be provided in each block.

In addition, one communication hole 30 may be provided for one auxiliary air chamber 26 to be used for both supply and exhaust, or two communication holes 30 may be provided, one for intake and the other for exhaust.
When the tire / rim wheel assembly 14 is provided with a pressure sensor, the pressure detection signal may be transmitted wirelessly using a wireless device in addition to the method of transmitting the pressure detection signal to the controller 54 via wiring.

1 is a cross-sectional view of a tire / rim wheel assembly according to a first embodiment. It is an expanded sectional view of a tread. It is a block diagram which shows piping and wiring. (A), (B) is sectional drawing of the tire and rim wheel assembly which concerns on 2nd Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 3rd Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 4th Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 5th Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 6th Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 7th Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 8th Embodiment. It is sectional drawing of the tire and rim wheel assembly which concerns on 9th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 11 Tire air chamber 12 Rim wheel 12B Well part 12A Disk part 14 Tire / rim wheel assembly 24 Circumferential groove 26 Sub air chamber 28 Shoulder rib (land part)
DESCRIPTION OF SYMBOLS 30 Communication hole 32 Piping 34 Tire connection member 38 Air compressor 46 On-off valve 50 Pressure sensor 52 Valve 54 Controller 56 Gas tank 58 Pressure control valve 59 On-off valve 60 Gas tank 62 Tube 66 Supply / exhaust device 68 Double rod double acting cylinder 72 Actuator

Claims (20)

A carcass straddling a pair of bead cores;
A belt disposed on the outer side in the tire radial direction of the carcass;
A tread rubber layer disposed on the outer side in the tire radial direction of the belt;
A sub air chamber provided on at least one side of the tread rubber layer on the tire width direction of the tire equatorial plane;
A communication path connected to the auxiliary air chamber, allowing communication between the auxiliary air chamber and the outside of the tire to allow gas to be taken in and out of the auxiliary air chamber;
With
When the width of the auxiliary air chamber measured along the tread when viewed in a cross section along the tire rotation axis is AW and the ground contact width of the tread rubber layer is TW, the width AW is relative to the ground contact width TW. The pneumatic tire is characterized by being set within a range of 5% or more and less than 50%. When the position spaced from the ground contact edge to the tire equatorial plane side by a distance corresponding to 1/4 of the ground contact width TW is set to 1/4 point, the auxiliary air chamber is located outside the 1/4 point in the tire width direction. The pneumatic tire according to claim 1, wherein the pneumatic tire is disposed in A plurality of circumferential grooves extending along the tire circumferential direction are formed in the tread rubber layer, and the auxiliary air chamber is disposed on the outer side in the tire width direction than the circumferential groove on the outermost side in the tire width direction. The pneumatic tire according to claim 1, wherein the pneumatic tire is a tire. The pneumatic tire according to any one of claims 1 to 3, wherein the auxiliary air chamber is formed in an annular shape continuously in the tire circumferential direction. The thickness of the tread rubber layer is TG, the distance measured along the tread from the tire equatorial plane to the auxiliary air chamber is EW, the width dimension measured along the tread of the auxiliary air chamber is AW, When the maximum height dimension measured along the tire radial direction is H, and the width of the belt measured along the tread is BW,
Any one of claims 1 to 4, wherein EW <BW / 2 <EW + AW, EW <TW / 2 <EW + AW, and 0.1 <H / TG <0.5 are satisfied. The pneumatic tire according to claim 1. The communication path is open to the inner surface of the tire, and a connection member for connecting a pipe for taking gas into and out of the auxiliary air chamber is attached to the opening. The pneumatic tire according to any one of claims 1 to 5. The said communicating path is opened to the tire inner surface side, The 1st on-off valve is attached to the said communicating path, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Pneumatic tire. The pneumatic tire according to any one of claims 1 to 7, further comprising a pressure sensor that detects an internal pressure of the auxiliary air chamber. The pneumatic tire according to any one of claims 1 to 8, further comprising transmission means for wirelessly transmitting pressure detection data detected by the pressure sensor. A tire / rim wheel assembly comprising the pneumatic tire according to any one of claims 1 to 9 assembled to a rim wheel. A second on-off valve is attached to the rim wheel, and the second on-off valve has a first connecting port disposed outside the rim wheel and the other connecting port connected to the auxiliary air chamber. The tire / rim wheel assembly according to claim 10, wherein the tire / rim wheel assembly is connected to a pipe. A first gas tank provided in the rim wheel and filled with a gas to be supplied to the auxiliary air chamber;
A second pipe connecting the auxiliary air chamber and the first gas tank;
The tire / rim wheel assembly according to claim 10, comprising: The tire / rim wheel assembly according to claim 12, wherein the first gas tank is provided in a wheel disc portion. The tire / rim wheel assembly according to claim 12, wherein the first gas tank is formed on the side of the drop portion of the rim so as not to have a smaller diameter than the inner diameter of the drop portion. . The said rim wheel has a 1st pressure change means to change the internal pressure of the said sub air chamber by moving gas between the said 1st gas tank and the said sub air chamber. Item 15. The tire / rim wheel assembly according to any one of Items 12 to 14. 11. The tire / rim wheel set according to claim 10, further comprising a second pressure changing unit that changes an internal pressure of the auxiliary air chamber by moving a gas between the atmosphere and the auxiliary air chamber. Solid. A second gas tank provided on an outer periphery of the rim wheel and filled with a gas to be supplied to the auxiliary air chamber;
A third pipe connecting the auxiliary air chamber and the second gas tank;
An on-off valve connected to at least the third pipe;
The tire / rim wheel assembly according to claim 10, comprising: The tire / rim wheel assembly according to claim 17, wherein the second gas tank is an annular tube made of an elastic body. The pneumatic tire is provided with the auxiliary air chambers on both sides of the tread rubber layer across the tire equator plane,
The rim wheel is provided with a double acting cylinder driven by an actuator,
The one sub air chamber is connected to one cylinder chamber of the double acting cylinder, and the other sub air chamber is connected to the other cylinder chamber of the double acting cylinder. Tire / rim wheel assembly. A vehicle comprising the tire / rim wheel assembly according to any one of claims 10 to 19.

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