JP2007331664A - Pneumatic tire internal pressure controller, pneumatic tire internal pressure control system, vehicle, and pneumatic tire internal pressure controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire internal pressure controller capable of improving a vehicle operating stability, a pneumatic tire internal pressure control system, a vehicle and a pneumatic internal pressure controlling method by using a pneumatic tire having a plurality of air chambers along a tread width direction. <P>SOLUTION: A pneumatic tire internal pressure controller 100 causes an internal pressure of an inside gas chamber (IN) positioned inside in a vehicle width direction when the tire is installed at a vehicle to be higher than an internal pressure of an outside gas chamber (OUT) positioned more outside in the vehicle width direction than in the inside gas chamber when the tire is installed at the vehicle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pneumatic tire internal pressure control device that controls the internal pressure of a pneumatic tire, a pneumatic tire internal pressure control system, a vehicle, and a pneumatic tire internal pressure control method.

  In particular, the present invention relates to a pneumatic tire internal pressure control device, a pneumatic tire internal pressure control system, and a pneumatic tire that control the internal pressure of a pneumatic tire having a plurality of air chambers along the tread width direction while being mounted on a vehicle. The present invention relates to an internal pressure control method. The present invention also relates to a vehicle including the pneumatic tire internal pressure control device or the pneumatic tire internal pressure control system.

  2. Description of the Related Art Conventionally, a so-called intelligent tire system that estimates a ground contact state (road surface μ) of a pneumatic tire mounted on a vehicle and controls a traveling state of the vehicle according to the estimated ground contact state is known (for example, patent document). 1).

  Specifically, the intelligent tire system estimates the ground contact state (road surface μ) of the pneumatic tire based on the output signal of the vibration sensor mounted on the rim wheel on which the pneumatic tire is assembled. Accordingly, the braking device of the vehicle or the engine speed can be controlled.

In recent years, even when a pneumatic tire is damaged, a plurality of air chambers (for example, three air chambers) along the tread width direction of the pneumatic tire so that the vehicle can travel a certain distance (so-called run-flat traveling). ) Has been proposed (for example, Patent Document 2).
Japanese Patent Laid-Open No. 2002-79815 (page 5-6, FIG. 2) Japanese Patent Laying-Open No. 2003-39914 (page 3, FIG. 1)

  By the way, the inventors of the present application have made extensive studies so far, and as a result, by setting the internal pressure of each air chamber provided in the pneumatic tire including the plurality of air chambers described above to an appropriate value, We learned that the stability of the vehicle, that is, the performance of whether the vehicle moves according to the driver's intention and expectations, can be improved.

  However, the above-described intelligent tire system only controls the braking device of the vehicle or the engine speed according to the estimated ground contact state, and in this patent document, by actively changing the internal pressure of the pneumatic tire, There is no disclosure about improving the steering stability of the vehicle.

  Therefore, the present invention has been made in view of such a situation, and an air that can improve steering stability of a vehicle by using a pneumatic tire including a plurality of air chambers along the tread width direction. An object of the present invention is to provide a tire pressure control device, a pneumatic tire pressure control system, a vehicle, and a pneumatic tire pressure control method.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is a pneumatic tire internal pressure control device (pneumatic tire internal pressure control device) that controls the internal pressure of pneumatic tires (pneumatic tires 20FL, 20FR, 20RL, 20RR) mounted on a vehicle (automobile 10). A pneumatic tire internal pressure control device 100), wherein the pneumatic tire has a plurality of air chambers (a main air chamber C1, an inner sub air chamber C2in, and an outer sub air chamber C2out) along a tread width direction; The inner pressure of the inner air chamber (inner auxiliary air chamber C2in) positioned on the inner side in the vehicle width direction when mounted on the vehicle is set to the outside air positioned on the outer side in the vehicle width direction than the inner air chamber when mounted on the vehicle. The gist is to include an internal pressure control unit (controller 110) that makes the pressure higher than the internal pressure of the chamber (outer side air chamber C2out).

  According to such a pneumatic tire internal pressure control device, a lateral force is generated from the inner side in the vehicle width direction toward the outer side in the vehicle width direction. The lateral force is similar to the camber thrust, and is a lateral force in the same direction as the camber thrust generated when a negative camber is applied to the pneumatic tire mounted on the vehicle.

  That is, according to such a pneumatic tire internal pressure control device, the steering stability of the vehicle can be improved as in the case where the negative camber is provided.

  A second feature of the present invention relates to the first feature of the present invention, and is a mode (for example, a normal travel mode and a sport travel mode) according to a road surface state where the pneumatic tire rolls or a traveling method of the vehicle. ) Is determined, and the internal pressure control unit changes the internal pressures of the plurality of air chambers based on the mode determined by the mode processing unit. The gist.

  A third feature of the present invention relates to the second feature of the present invention, wherein the mode processing unit includes, as the mode, a normal road surface mode (dry road surface mode), and the pneumatic tire more than the normal road surface mode. A low μ road mode (for example, a snow road surface mode) selected when the vehicle travels on a low μ road (for example, a snow road surface) having a low coefficient of friction with a road surface, and the internal pressure control unit When the low μ road mode is selected by the processing unit, the gist is to make at least the internal pressure of the inner air chamber lower than that in the normal road surface mode.

  A fourth feature of the present invention relates to the second or third feature of the present invention, wherein the mode processing unit includes, as the mode, a normal travel mode, and a grip limit of the pneumatic tire as compared with the normal travel mode. A sports travel mode that is selected when the vehicle travels in a state in which a force close to is applied, and the internal pressure control unit, when the sport travel mode is selected by the mode processing unit, the normal travel mode The gist is to increase the internal pressure of the outer air chamber.

  A fifth feature of the present invention relates to the third feature of the present invention, wherein the pneumatic tire has a main air chamber (main air chamber C1) provided between the inner air chamber and the outer air chamber. Furthermore, the gist of the invention is that the internal pressure control unit makes only the internal pressure of the inner air chamber lower than that of the normal road surface mode without changing the internal pressure of the main air chamber.

  A sixth feature of the present invention relates to the fourth feature of the present invention, wherein the pneumatic tire has a main air chamber (main air chamber C1) provided between the inner air chamber and the outer air chamber. Furthermore, the gist of the invention is that the internal pressure control unit raises only the internal pressure of the outer air chamber higher than that in the normal travel mode without changing the internal pressure of the main air chamber.

  A seventh feature of the present invention relates to the third feature of the present invention, wherein the pneumatic tire further includes a main air chamber provided between the inner air chamber and the outer air chamber, and the internal pressure When the low μ road mode is selected by the mode processing unit, the control unit specifically determines that the friction coefficient is low and is on ice as the friction coefficient decreases, or the friction When the coefficient is around 0.1, the gist is to reduce the internal pressure of the main air chamber.

  An eighth feature of the present invention relates to the fifth to seventh features of the present invention, and is summarized in that the inner air chamber and the outer air chamber have a smaller volume than the main air chamber.

  The ninth feature of the present invention is the pneumatic tire according to the first feature of the present invention (pneumatic tires 20FL, 20FR, 20RL, 20RR) and the pneumatic tire according to the first to eighth features of the present invention. The gist of the present invention is a pneumatic tire internal pressure control system including an internal pressure control device (pneumatic tire internal pressure control device 100).

    A tenth feature of the present invention is a vehicle (automatic four-wheeled vehicle 10) including the pneumatic tire internal pressure control device (pneumatic tire internal pressure control device 100) according to the first to eighth features of the present invention. The gist.

  An eleventh feature of the present invention is a vehicle (automatic four) equipped with a pneumatic tire internal pressure control system (pneumatic tires 20FL, 20FR, 20RL, 20RR and a pneumatic tire internal pressure control device 100) according to the ninth feature of the present invention. The gist is that it is a wheeled wheel 10).

  A twelfth feature of the present invention is a pneumatic tire internal pressure control method for controlling an internal pressure of a pneumatic tire mounted on a vehicle, wherein the pneumatic tire has a plurality of air chambers along a tread width direction. And the inner pressure of the inner air chamber located on the inner side in the vehicle width direction when mounted on the vehicle is greater than the inner pressure of the outer air chamber positioned on the outer side in the vehicle width direction than the inner air chamber when mounted on the vehicle. The gist is to make it higher.

  A thirteenth aspect of the present invention relates to the twelfth aspect of the present invention, wherein a mode corresponding to a road surface state where the pneumatic tire rolls or a mode of travel of the vehicle is determined, and the determined mode is Based on this, the gist is to change the internal pressure of the plurality of air chambers.

  According to the characteristics of the present invention, a pneumatic tire internal pressure control device and a pneumatic tire internal pressure control capable of improving the steering stability of a vehicle using a pneumatic tire including a plurality of air chambers along the tread width direction. A system, a vehicle, and a pneumatic tire internal pressure control method can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Overall schematic configuration of vehicle)
FIG. 1 is an overall schematic diagram of a four-wheeled vehicle 10 constituting a vehicle in the present embodiment. The automobile 4 is a passenger car that runs using an engine or a motor (not shown) as a power source.

  The automobile 4 includes four tires, specifically, pneumatic tires 20FL, 20FR, 20RL, and 20RR that are assembled to the rim wheel 40. In FIG. 1, the pneumatic tire 20FR and the pneumatic tire 20RR mounted on the right side of the automobile 10 are not shown (see FIG. 3).

  The automobile 4 includes a steering wheel 30. When the driver P rotates the steering wheel 30, the pneumatic tire 20FL and the pneumatic tire 20FR are directed to the right or left side in the traveling direction.

  In addition, the automobile 10 includes a pneumatic tire internal pressure that controls the internal pressure of pneumatic tires 20FL, 20FR, 20RL, and 20RR (hereinafter abbreviated as “pneumatic tire” as appropriate) mounted on the automobile 10. A control device 100 (not shown in FIG. 1, refer to FIG. 3) is provided.

  The pneumatic tire internal pressure control device 100 includes the controller 110, the sensor unit 120, the operation panel 130, the compressor 140, the air tank 150, the rotary joint 151, and the like shown in FIG. A specific configuration of the pneumatic tire internal pressure control device 100 will be described later.

  The controller 110 controls the internal pressure of the pneumatic tire based on signals (instructions) output from the sensor unit 120, the operation panel 130, and the like.

  The sensor unit 120 includes various sensors that detect the traveling state of the automobile 10. Specifically, the sensor unit 120 includes an acceleration sensor, a steering angle sensor (or a steering torque sensor), and the like.

  The operation panel 130 is disposed on a dashboard (not shown). The operation panel 130 can cause the driver P (or a rider of the four-wheeled vehicle 10) to select a mode (road surface mode, travel mode) described later.

  The compressor 140 pumps the gas stored in the air tank 150 to the pneumatic tire. Specifically, the gas pumped by the compressor 140 is supplied to each pneumatic tire via an air hose 145 and a rotary joint 151 disposed on the inner side in the vehicle width direction of the rim wheel 40.

(Composition of pneumatic tire)
FIG. 2 is a cross-sectional view in the tread width direction of a pneumatic tire 20FL attached to the left front position of the automobile 10. As shown in FIG. The pneumatic tires 20FR, 20RL, 20RR have the same configuration as the pneumatic tire 20FL.

  As shown in FIG. 2, the pneumatic tire 20FL includes a tread 21 that is in contact with the road surface, sidewalls 22A and 22B, and beads 23 in the same manner as a conventional pneumatic tire. The bead 23 is locked by a bead seat 41 of the rim wheel 40.

  The pneumatic tire 20FL includes a carcass 24 that forms a skeleton of the pneumatic tire 20FL and a belt layer 25 that reinforces the carcass 24.

  The pneumatic tire 20FL is greatly different from the conventional pneumatic tire in the following points. That is, the pneumatic tire 20FL has a plurality of air chambers along the width direction of the tread 21 (hereinafter, appropriately abbreviated as “tread width direction”).

  Specifically, in the space inside the sidewall 22A, by providing the partition wall portion 31A and the partition wall portion 31B between the rim wheel 40 and the inner surface of the tread 21, the main air chamber C1 and the outer sub air chamber C2out are provided. (Outer air chamber) and inner auxiliary air chamber C2in (inner air chamber) are formed.

  The partition wall portion 31 </ b> A and the partition wall portion 31 </ b> B have an inner carcass 33 formed of the same material as the carcass 24. Moreover, the inner side bead 32 latched by the inner side bead sheet 42 is formed in the lower end of the partition part 31A and the partition part 31B.

  The main air chamber C1 is formed at a position including the tire equator line CL in the cross section in the tread width direction. The main air chamber C1 is provided between the inner sub air chamber C2in and the outer sub air chamber C2out.

  The inner auxiliary air chamber C2in is located on the inner side in the vehicle width direction when mounted on the four-wheeled vehicle 10. The outer side auxiliary air chamber C2out is located on the outer side in the vehicle width direction with respect to the inner side auxiliary air chamber C2in when mounted on the four-wheeled vehicle 10. Furthermore, the volumes of the outer side air chamber C2out and the inner side air chamber C2in are smaller than the volume of the main air chamber C1.

(Function block configuration of pneumatic tire internal pressure control system)
FIG. 3 is a functional block configuration diagram of the pneumatic tire internal pressure control system according to the present embodiment. In the present embodiment, the pneumatic tire internal pressure control system is configured by the pneumatic tires 20FL, 20FR, 20RL, and 20RR and the pneumatic tire internal pressure control device 100.

  The pneumatic tire 20FL is attached to the left front position of the automobile 10. The pneumatic tire 20FR is attached to the right front position of the automobile 10.

  Further, the pneumatic tire 20RL is attached to the left rear position of the automobile 10. The pneumatic tire 20RR is attached to the right rear position of the automobile 10.

  The pneumatic tire internal pressure control device 100 includes a controller 110, a sensor unit 120, an operation panel 130, a compressor 140, an air hose 145, an air tank 150, a rotary joint 151, and an electro-pneumatic pressure conversion unit 160.

  The controller 110 controls the electro-pneumatic converter 160 based on signals output from the sensor unit 120, the operation panel 130, and the electro-pneumatic converter 160.

  In the present embodiment, the controller 110 controls the electro-pneumatic converter 160 based on a signal indicating a road surface mode or a travel mode output from the operation panel 130. The controller 110 controls the electro-pneumatic converter 160 to change the internal pressure of the outer auxiliary air chamber C2out, the inner auxiliary air chamber C2in, or the main air chamber C1 provided in each pneumatic tire.

In the pneumatic tire internal pressure control apparatus 100, the modes shown in Table 1 are provided.

  As shown in Table 1, in this embodiment, a dry road mode, a wet road mode, a snow road mode, and an ice road mode are prepared as modes (road surface modes) according to the road surface state in which the pneumatic tire rolls. .

  The dry road surface mode (normal road surface mode) is a mode selected when traveling on a dry asphalt road surface, and the road surface μ is about 0.7 to 0.8.

  The low μ road mode selected when the automobile 10 travels on a low μ road where the friction coefficient (μ) between the pneumatic tire and the road surface R is lower than that in the dry road surface mode. A road surface mode and an on-ice road surface mode are prepared.

  The wet road surface mode is a mode suitable for traveling on a wet asphalt road surface, and the road surface μ is about 0.45 to 0.6. The on-snow road surface mode is a mode selected when traveling on a snow-covered road surface, and the road surface μ is about 0.15. The icy road surface mode is a mode selected when traveling on an icy road surface, and the road surface μ is about 0.07.

  In addition, a normal travel mode and a sport travel mode are prepared as modes (travel modes) corresponding to the manner in which the automobile 10 travels.

  The normal travel mode is a mode suitable for the case where the four-wheeled vehicle 10 travels on a road having a relatively small curve, or travels in accordance with the speed of other vehicles (so-called traffic flow).

  The sport driving mode is a mode suitable for the case where the driver P of the automobile 10 performs acceleration / deceleration and steering operation more suddenly than in the normal driving mode, or travels on a curved road (winding road) or circuit. is there. That is, the sport travel mode is selected when the automobile 4 travels in a state where a force closer to the grip limit of the pneumatic tire is applied than in the normal travel mode.

  The controller 110 changes the internal pressure of the outer side air chamber C2out, the inner side air chamber C2in, or the main air chamber C1 provided in each pneumatic tire according to the above-described mode. In the present embodiment, the controller 110 constitutes an internal pressure control unit.

  In this embodiment, the controller 110 makes the internal pressure of the inner side auxiliary air chamber C2in higher than the inner pressure of the outer side auxiliary air chamber C2out in both modes. For example, when the normal road mode and the normal travel mode are selected, the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in are set to 100 kPa, 200 kPa, and 350 kPa, respectively (see FIG. 6). (See “Condition 2”).

  Further, the controller 110 changes the internal pressure of the outer side air chamber C2out, the inner side air chamber C2in, or the main air chamber C1 based on the determined mode. Specifically, the controller 110 changes the internal pressure of the outer auxiliary air chamber C2out or the main air chamber C1 based on the mode selected by the driver P operating the operation panel 130.

  When the driver P operates the operation panel 130 and the wet road surface mode, the snow road surface mode, or the ice road surface mode (low μ road mode) is selected, the controller 110 is inward of the dry road surface mode (normal road surface mode). Lower the internal pressure of the auxiliary air chamber C2in.

  For example, as shown in “condition 6” in FIG. 6, in the snowy road surface mode, the controller 110 changes the internal pressure of the inner auxiliary air chamber C2in (IN) from 350 kPa to 250 kPa. In this case, the controller 110 does not change the internal pressure of the main air chamber C1, remains 200 kPa, and makes only the internal pressure of the inner auxiliary air chamber C2in lower than in the normal road surface mode.

  Further, when the wet road surface mode, the snow road surface mode, or the ice road surface mode is selected, the controller 110 can also decrease the internal pressure of the main air chamber C1 as the road surface μ decreases. For example, as shown in “condition 7” in FIG. 6, in the on-ice road surface mode, the controller 110 changes the internal pressure of the main air chamber C1 (CTR) from 200 kPa to 180 kPa.

  In addition, when the sport driving mode is selected by the driver P operating the operation panel 130, the controller 110 increases the internal pressure of the outer side auxiliary air chamber C2out as compared with the normal driving mode.

  For example, as shown in “Condition 3” in FIG. 6, in the sport running mode (and the dry road surface mode), the controller 110 changes the internal pressure of the outer auxiliary air chamber C2out (OUT) from 100 kPa to 150 kPa. In this case, the controller 110 does not change the internal pressure of the main air chamber C1 and remains at 200 kPa, and makes only the internal pressure of the outer auxiliary air chamber C2out higher than in the normal travel mode.

  As described above, the sensor unit 120 includes various sensors that detect the traveling state of the four-wheeled vehicle 10. Specifically, the sensor unit 120 includes an acceleration sensor, a steering angle sensor, and the like.

  The operation panel 130 is provided on a dashboard (not shown) of the automobile 10. The operation panel 130 can cause the driver P to select the above-described mode. Specifically, the operation panel 130 allows the driver P to select a road surface mode (dry road surface mode, wet road surface mode, snow road surface mode or ice road surface mode) and a travel mode (normal travel mode or sport travel mode). it can.

  The operation panel 130 outputs a signal corresponding to the road surface mode and the travel mode selected by the driver P to the controller 110. In the present embodiment, the operation panel 130 constitutes a mode processing unit that determines a road surface mode and a travel mode.

  The compressor 140 injects gas (compressed air) into the air tank 150. The gas stored in the air tank 150 is supplied to each pneumatic tire via the air hose 145 and the rotary joint 151.

  The air tank 150 stores the gas supplied to each pneumatic tire. The air tank 150 is connected to the air chamber of the pneumatic tire through the electro-pneumatic converter 160, the air hose 145, and the rotary joint 151.

  The electro-pneumatic converter 160 adjusts the pressure of the gas supplied to each air chamber of the pneumatic tire. In addition, the electro-pneumatic converter 160 outputs information indicating the pressure of the gas supplied to each air chamber of the pneumatic tire to the controller 110.

(Operation of pneumatic tire internal pressure control system)
Next, the operation of the above-described pneumatic tire internal pressure control system (pneumatic tires 20FL, 20FR, 20RL, 20RR and the pneumatic tire internal pressure control device 100) will be described. Specifically, the adjustment operation of the internal pressure of each air chamber by the pneumatic tire internal pressure control system will be described.

  FIG. 4 shows an internal pressure adjusting operation flow by the pneumatic tire internal pressure control system. As shown in FIG. 4, in step S10, the driver P selects an appropriate road surface mode according to the state of the road surface on which the four-wheeled vehicle 10 travels. Specifically, the driver P operates the operation panel 130 to select any one of a dry road surface mode, a wet road surface mode, a snow road surface mode, and an ice road surface mode.

  Furthermore, the driver P selects an appropriate travel mode according to the manner of travel. Specifically, the driver P operates the operation panel 130 to select either the normal travel mode or the sport travel mode.

  In step S20, the pneumatic tire internal pressure control device 100 adjusts the internal pressure of the outer auxiliary air chamber C2out, the inner auxiliary air chamber C2in, or the main air chamber C1 to the air pressure according to the mode selected by the driver P.

  For example, when the dry road surface mode is selected as the road surface mode and the normal travel mode is selected as the travel mode, the internal pressures of the outer auxiliary air chamber C2out, the main air chamber C1, and the inner auxiliary air chamber C2in are 100 kPa, 200 kPa, and 350 kPa. These are set (see “Condition 2” in FIG. 6).

(Action / Effect)
Next, operations and effects of the pneumatic tire internal pressure control system according to the present embodiment will be described. FIG. 6 shows an evaluation index of the running feeling according to the internal pressure values of the outer auxiliary air chamber C2out, the main air chamber C1, and the inner auxiliary air chamber C2in. In FIG. 6, the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in are indicated as OUT, CTR, and IN.

  In FIG. 6, the test driver when the inner pressures of the outer side air chamber C2out (OUT), the main air chamber C1 (CTR), and the inner side air chamber C2in (IN) are all set to 200 kPa ("condition 1" in the figure). The evaluation index of other conditions is shown with the evaluation score of the running feeling of 100 as 100. It shows that driving feeling evaluation, ie, the handling stability of the four-wheeled vehicle 10, is so high that the value of an evaluation index is large.

  When performing normal driving instead of sports driving on a dry road surface, as shown in “Condition 2”, the internal pressures of the outer auxiliary air chamber C2out, the main air chamber C1, and the inner auxiliary air chamber C2in are set to 100 kPa, 200 kPa, and 350 kPa, respectively. It is preferable to set. In addition, when performing sport driving on a dry road surface, as shown in “Condition 3”, the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in are set to 150 kPa, 200 kPa, and 350 kPa, respectively. Is preferred.

  When performing normal traveling on a wet road surface, as shown in “Condition 4”, it is preferable to set the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in to 100 kPa, 200 kPa, and 300 kPa, respectively. . Also, when running on a wet road, as shown in “Condition 5”, the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in should be set to 150 kPa, 200 kPa, and 300 kPa, respectively. Is preferred.

  Furthermore, on the snowy road surface, as shown in “Condition 6”, it is preferable to set the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in to 150 kPa, 200 kPa, and 250 kPa, respectively.

  On the ice road surface, as shown in “Condition 7”, it is preferable to set the internal pressures of the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in to 100 kPa, 180 kPa, and 250 kPa, respectively. On the road surface on ice, the internal pressure of the main air chamber C1 is also changed (from 200 kPa to 180 kPa).

  In addition, it was set as the form which can select only a road surface mode, without distinguishing with a driving mode (normal driving mode, sports driving mode) on a snowy road surface and an ice surface.

  FIGS. 7A to 7C illustrate the relationship of the internal pressures of typical combinations among the combinations of the road surface mode and the traveling mode shown in FIG. 7A to 7C, the outer side air chamber C2out, the main air chamber C1, and the inner side air chamber C2in are represented as OUT, CTR, and IN.

  FIG. 7B shows the internal pressure value (OUT / CTR / IN = 100/200/350 kPa) of each air chamber in the combination of the dry road surface mode and the normal traveling mode.

  FIG. 7A shows the internal pressure value (OUT / CTR / IN = 150/200/350 kPa) of each air chamber in the combination of the dry road surface mode and the sport running mode.

  FIG.7 (c) has shown the internal pressure value (OUT / CTR / IN = 100/200 / 250kPa) of each air chamber in snowy road surface mode.

  Comparing FIG. 7A and FIG. 7B, in the sport running mode, the internal pressure (shaded portion in the drawing) of the outer side auxiliary air chamber C2out is high. Further, comparing FIG. 7B and FIG. 7C, in the on-snow road surface mode, the internal pressure of the inner auxiliary air chamber C2in (the hatched portion in the figure) is low.

  As shown in FIG. 6 and FIGS. 7A to 7C, the running feeling evaluation of the test driver is increased by making the inner pressure of the inner auxiliary air chamber C2in higher than that of the outer auxiliary air chamber C2out. That is, when the inner pressure of the inner auxiliary air chamber C2in is made higher than that of the outer auxiliary air chamber C2out, the steering stability of the four-wheeled vehicle 10, specifically, the four-wheeled vehicle 10 moves as the driver P intends and expects. Whether or not the performance can be improved.

  When the internal pressure of the inner side auxiliary air chamber C2in is made higher than that of the outer side auxiliary air chamber C2out, a lateral force is generated from the inner side in the vehicle width direction toward the outer side in the vehicle width direction. The lateral force is similar to the camber thrust, and is a lateral force in the same direction as the camber thrust generated when a negative camber is applied to the pneumatic tire attached to the automobile 10.

  That is, according to the pneumatic tire internal pressure control system according to the present embodiment, the steering stability of the four-wheeled vehicle 10 can be improved as in the case where the negative camber is provided.

  In this embodiment, when the wet road surface mode, the snow road surface mode, or the ice road surface mode (low μ road mode) is selected, the internal pressure of the inner auxiliary air chamber C2in is adjusted to be lower than that in the dry road surface mode (normal road surface mode). . When the internal pressure of the inner side auxiliary air chamber C2in is lowered, the response of the four-wheeled vehicle 10 to a steering operation or the like becomes moderately slow, and the peaky characteristics of the four-wheeled vehicle 10 can be weakened. On a low μ road, the steering stability (particularly stability) of the automobile 4 can be improved by weakening the peaky characteristics of the automobile 4.

  Furthermore, in this embodiment, the internal pressure of the main air chamber C1 can be lowered as the road surface μ becomes lower. When the internal pressure of the main air chamber C1 is lowered, the peaky characteristics of the automobile 10 can be further weakened. For this reason, the stability of the four-wheeled vehicle 10 on an icy road surface can be further improved.

  In the present embodiment, when the sports travel mode is selected, the internal pressure of the outer side auxiliary air chamber C2out is adjusted to be higher than that in the normal travel mode. When the internal pressure of the outer side air chamber C2out increases, the rigidity of the pneumatic tire during cornering or the like increases, and the direct maneuverability required during sports running, for example, the response speed to the steering operation can be increased.

  In this embodiment, the internal pressure of the main air chamber C1 is not changed except for the on-ice road surface mode, and only the internal pressure of the outer auxiliary air chamber C2out is increased, or only the internal pressure of the inner auxiliary air chamber C2in is decreased. That is, the internal pressure of the main air chamber C1 whose volume is larger than that of the outer sub-air chamber C2out and the inner sub-air chamber C2in is not changed except on the ice road surface mode. For this reason, since only the internal pressures of the outer sub-air chamber C2out and the inner sub-air chamber C2in having a relatively small volume are adjusted, it is possible to adjust the inner pressure more quickly.

(Other embodiments)
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above-described embodiment of the present invention, the driver P selects an appropriate road mode and travel mode by operating the operation panel 130. However, for example, the controller 110 may select the travel mode based on the signal output from the sensor unit 120.

  FIG. 5 shows an internal pressure adjusting operation flow by the pneumatic tire internal pressure control system according to such a modified example. As shown in FIG. 5, in step S <b> 110, the pneumatic tire internal pressure control system detects a signal output from the sensor unit 120.

  In step S120, the pneumatic tire internal pressure control system determines whether or not the value of the detected signal satisfies a predetermined condition. Specifically, the pneumatic tire internal pressure control system is configured to change the value of a signal output from an acceleration sensor or a steering angle sensor included in the sensor unit 120 and a preset threshold value to the four-wheeled vehicle 10. It is determined whether the running state is normal running or sports running. In addition, you may determine with the driving | running | working state of the four-wheeled motor vehicle 10 being sport driving | running when the state exceeding the threshold value set beforehand is not only a threshold value but continues for the predetermined time.

  When the value of the detected signal satisfies a predetermined condition (YES in step S120), in step S130, the pneumatic tire internal pressure control system sets the outside auxiliary air to the air pressure according to the mode associated with the condition. The internal pressure of the chamber C2out, the inner auxiliary air chamber C2in, or the main air chamber C1 is adjusted.

  According to such a modified example, since the traveling state of the four-wheeled vehicle 10 is determined by the pneumatic tire internal pressure control system, the driver P does not need to select the traveling mode according to the traveling manner. In addition, a sensor that estimates the road surface μ may be provided in a pneumatic tire or the like, and the road surface state in which the automobile 4 travels may be determined by a pneumatic tire internal pressure control system.

  Further, in the above-described embodiment of the present invention, the internal pressure of the main air chamber C1 having a large volume is not changed except in the road mode on ice, but if the amount is small (about 20 kPa), the internal pressure of the main air chamber C1 is reduced. It may be changed. Furthermore, the internal pressure values in the above-described embodiments are merely examples, and different values may be used depending on the type of vehicle on which the pneumatic tire is mounted.

  In the above-described embodiment, the pneumatic tire provided with the three air chambers of the main air chamber C1, the outer sub air chamber C2out, and the inner sub air chamber C2in is used. However, for example, two air chambers and four air chambers are provided. Pneumatic tires may be used.

  Furthermore, instead of the pneumatic tire used in the above-described embodiment, a pneumatic tire including a plurality of air chambers inside the tread 21 may be used. Further, the air chamber may be formed by a chain bubble member such as chain foam rubber in which bubbles are chained with other bubbles. Alternatively, instead of the pneumatic tire used in the present embodiment, a tire tube having a plurality of air chambers may be used.

  In the above-described embodiment, the pneumatic tires 20FL, 20FR, 20RL, and 20RR are controlled. However, for example, only the pneumatic tires on the front side (pneumatic tires 20FL, 20FR) may be controlled.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

1 is an overall schematic diagram of a vehicle according to an embodiment of the present invention. It is a tread width direction sectional view of a pneumatic tire concerning an embodiment of the present invention. It is a functional block block diagram of the pneumatic tire internal pressure control system which concerns on embodiment of this invention. It is an adjustment operation | movement flowchart of the internal pressure by the pneumatic tire internal pressure control system which concerns on embodiment of this invention. It is an adjustment operation | movement flowchart of the internal pressure by the pneumatic tire internal pressure control system which concerns on the example of a change of this invention. It is a figure which shows the evaluation index | exponent of the driving | running | working feeling by the value of the internal pressure adjusted using the pneumatic tire internal pressure control system which concerns on embodiment of this invention. It is a figure which shows the relationship of the internal pressure of a typical combination among the combinations of the road surface mode and driving | running | working mode prescribed | regulated in the pneumatic tire internal pressure control system which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Automobile, 20FL, 20FR, 20RL, 20RR ... Pneumatic tire, 21 ... Tread, 22A, 22B ... Side wall, 23 ... Bead, 24 ... Carcass, 25 ... Belt layer, 30 ... Steering wheel, 31A, 31B: partition wall part, 32 ... inner bead, 33 ... inner carcass, 40 ... rim wheel, 41 ... bead seat, 42 ... inner bead seat, 100 ... pneumatic tire internal pressure control device, 110 ... controller, 120 ... sensor part, 130 ... Operation panel, 140 ... Compressor, 145 ... Air hose, 150 ... Air tank, 151 ... Rotary joint, 160 ... Electro-pneumatic converter, C1 ... Main air chamber, C2in ... Inner side air chamber, C2out ... Outer side air chamber, CL ... tire equator line, P ... driver, R ... road surface

Claims (13)

A pneumatic tire internal pressure control device for controlling the internal pressure of a pneumatic tire mounted on a vehicle,
The pneumatic tire has a plurality of air chambers along the tread width direction,
The inner pressure of the inner air chamber located on the inner side in the vehicle width direction when mounted on the vehicle is set higher than the inner pressure of the outer air chamber positioned on the outer side in the vehicle width direction than the inner air chamber when mounted on the vehicle. A pneumatic tire internal pressure control device including an internal pressure control unit. A mode processing unit for determining a mode according to a road surface state where the pneumatic tire rolls or a way of traveling of the vehicle;
2. The pneumatic tire internal pressure control device according to claim 1, wherein the internal pressure control unit changes internal pressures of the plurality of air chambers based on the mode determined by the mode processing unit. The mode processing unit is selected as a normal road surface mode and a low μ road selected when the vehicle travels on a low μ road having a lower coefficient of friction between the pneumatic tire and the road surface than the normal road surface mode. Mode
3. The pneumatic tire internal pressure control device according to claim 2, wherein, when the low μ road mode is selected by the mode processing unit, the internal pressure control unit lowers at least the internal pressure of the inner air chamber as compared with the normal road surface mode. . The mode processing unit includes, as the mode, a normal travel mode and a sport travel mode selected when the vehicle travels in a state where a force closer to the grip limit of the pneumatic tire is applied than in the normal travel mode. Have
4. The pneumatic tire internal pressure control device according to claim 2, wherein the internal pressure control unit raises the internal pressure of the outer air chamber higher than that in the normal running mode when the sports running mode is selected by the mode processing unit. . The pneumatic tire further includes a main air chamber provided between the inner air chamber and the outer air chamber,
4. The pneumatic tire internal pressure control device according to claim 3, wherein the internal pressure control unit makes only the internal pressure of the inner air chamber lower than that of the normal road surface mode without changing the internal pressure of the main air chamber. The pneumatic tire further includes a main air chamber provided between the inner air chamber and the outer air chamber,
5. The pneumatic tire internal pressure control device according to claim 4, wherein the internal pressure control unit raises only the internal pressure of the outer air chamber higher than the normal travel mode without changing the internal pressure of the main air chamber. The pneumatic tire further includes a main air chamber provided between the inner air chamber and the outer air chamber,
4. The pneumatic tire internal pressure according to claim 3, wherein when the low μ road mode is selected by the mode processing unit, the internal pressure control unit decreases the internal pressure of the main air chamber as the friction coefficient decreases. Control device.   The pneumatic tire internal pressure control device according to any one of claims 5 to 7, wherein the inner air chamber and the outer air chamber have a smaller volume than the main air chamber. A pneumatic tire according to claim 1;
A pneumatic tire internal pressure control system including the pneumatic tire internal pressure control device according to claim 1.   A vehicle comprising the pneumatic tire internal pressure control device according to claim 1.   A vehicle comprising the pneumatic tire internal pressure control system according to claim 9. A pneumatic tire internal pressure control method for controlling the internal pressure of a pneumatic tire mounted on a vehicle,
The pneumatic tire has a plurality of air chambers along the tread width direction,
The inner pressure of the inner air chamber located on the inner side in the vehicle width direction when mounted on the vehicle is set higher than the inner pressure of the outer air chamber positioned on the outer side in the vehicle width direction than the inner air chamber when mounted on the vehicle. Pneumatic tire internal pressure control method. Determine the mode according to the road surface state where the pneumatic tire rolls or the way the vehicle runs,
The pneumatic tire internal pressure control method according to claim 12, wherein internal pressures of the plurality of air chambers are changed based on the determined mode.

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