JP6697347B2 - Vehicular tire air pressure variable device - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle tire air pressure varying device capable of varying a tire ground contact area during traveling.

  As is well known, the air pressure of a tire mounted on a vehicle is maintained at a substantially constant pressure, and when the air pressure drops, an air inflator is used to supplement the air pressure. When the tire pressure is high, the contact area with the ground is narrowed, so rolling resistance is reduced, and fuel consumption can be improved by that amount, but steering stability and braking performance are relatively reduced.

  On the other hand, when the tire pressure is low, the contact area with the ground becomes wider and the rigidity in the camber direction increases, so steering stability and braking performance are improved, but rolling resistance is relatively increased. As a result, fuel efficiency deteriorates.

  Therefore, for example, to improve fuel efficiency by increasing air pressure on a dry road surface during fine weather, and lowering the air pressure to ensure steering stability and braking performance when traveling on a wet road surface or a curved road such as in the case of rain. Preferably.

  However, it is difficult for the driver to set the air pressure one by one according to the traveling conditions. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2000-301904), a tire is provided with a pressure adjusting means, and the pressure adjusting means narrows the width direction of the tire from both side surfaces or relaxes the narrow pressure. Therefore, a technique for varying the ground contact area is disclosed.

JP, 2000-301904, A

  According to the technology disclosed in the above-mentioned documents, if the driver narrows the width direction of the tire with the pressure adjusting means during traveling, the air pressure increases and the ground contact area with the road surface decreases, thereby improving fuel efficiency. be able to. On the other hand, if the narrow pressure is alleviated, the air pressure is reduced and the ground contact area with the road surface is widened, so that the steering stability and the braking force can be improved.

  However, the pressure adjusting means disclosed in this document narrows the ground contact area of the tire by pinching a pair of pressing portions oppositely arranged in the width direction of the tire by the elastic force of the coil spring, while the cam By expanding the pressing portion against the biasing force of the coil spring with the lever, the pressing force against the tire is relaxed and the ground contact area is widened.

  Therefore, a coil spring with high spring pressure is required in order to firmly maintain a narrow pressure condition on the tire during running, and therefore, a cam and a lever for expanding the pressing portion against the biasing force of the coil spring are required. A strong structure is required. As a result, when the pressure adjusting device is provided on all the wheels of the vehicle, there is a disadvantage that the weight of the tire wheel increases, and the rolling resistance increases correspondingly, which deteriorates fuel efficiency. Further, since the tire pressure is mechanically squeezed and relaxed, a complicated link mechanism is required, and there is a disadvantage that the product cost becomes high due to the complicated structure.

  In view of the above circumstances, the present invention provides a vehicle tire air pressure varying device having a simple structure and capable of easily varying the tire ground contact area during traveling without significantly increasing the weight applied to each wheel. The purpose is to provide.

  A vehicle tire air pressure varying device according to the present invention includes a pair of first air chambers provided on both sides in the tire width direction and a second air chamber provided between the first air chambers and provided in the tire width direction center. A first air passage communicating between the first air chambers, a second air passage communicating the second air chamber with the first air passage, and a second air passage interposed between the first air passage and the second air passage. 2 A flow path switching unit for selectively setting a flow direction of air pressure from the air chamber to the first air passage and a flow direction of air pressure from the first air passage to the second air chamber, and the flow path switching And a control unit for controlling the switching operation of the section, and has a wide contact area drabiri mode and a narrow contact area eco-tire mode as a tire contact mode, the control unit, the tire contact mode is selected as the drivabilty mode. In this case, the flow direction of the air pressure of the flow path switching unit is set to flow from the second air chamber to the first air passage, and when the eco-tire mode is selected, the second air passage is set to the second air passage from the first air passage. Set to flow to air chamber.

  According to the present invention, the pair of first air chambers are provided on both sides in the tire width direction, the second air chamber is provided in the center, and the control unit sets the air pressure distribution direction to the first direction when the tire grounding mode is set to the dribery mode. The internal pressure applied to the tire during running is set so that the flow from the first air chamber to the second air chamber is set when the eco-tire mode is set. Due to the change, the air pressure in the second air chamber is gradually sent to the first air chamber in the dribery mode, the air pressure in the first air chamber increases, and the ground contact area of the tire increases.

  On the other hand, in the eco-tire mode, the air pressure in the first air chamber is gradually sent to the second air chamber, the air pressure in the second air chamber increases and the ground contact area of the tire decreases.

  As a result, it is possible to easily switch the tire ground contact mode between the drabli mode and the eco tire mode during traveling without providing a complicated link mechanism. Further, since the structure is simple, it is possible to prevent the fuel consumption from deteriorating correspondingly without significantly increasing the weight applied to each wheel.

Overall configuration diagram of the air pressure variable device according to the first embodiment Similarly, a schematic configuration diagram of the air pressure varying device when the tire grounding mode is set to the drabli mode Similarly, a schematic configuration diagram of a pneumatic pressure varying device when the tire grounding mode is set to eco tire mode Similarly, a flowchart showing a tire grounding mode setting routine Similarly, a cross-sectional view of the main part of the tire in a state where the tire grounding mode is set to the drabli mode Similarly, a cross-sectional view of the main part of the tire with the tire grounding mode set to eco tire mode Schematic configuration diagram of a pneumatic pressure varying device according to a second embodiment of the present invention. Similarly, a flowchart showing a tire grounding mode setting routine

  An embodiment of the present invention will be described below with reference to the drawings.

[First Embodiment]
1 to 6 show a first embodiment of the present invention. Reference numeral 1 in FIG. 1 denotes a vehicle such as an automobile, and wheels 2 are arranged on the front, rear, left and right sides of the vehicle 1. As shown in FIGS. 5 and 6, each wheel 2 includes a tire wheel 3 and a tire 4 respectively. And a pair of first tube 5a and second tube 5b. The pair of first tubes 5a are arranged on both sides in the width direction of the tire 4, and the second tube 5b is arranged between the first tubes 5a in the center of the tire 4 in the width direction. A first air chamber 5s and a second air chamber 5e are formed in each tube 5a, 5b.

  Further, an air valve 6 communicating with the first air chamber 5s is attached to a first tube 5a on the outer side in the width direction of the tire 4, and a valve cap 6a is attached to the air valve 6. A tire chuck as a valve connector provided in an air inflator (not shown) as an air pressure source is connected to the air valve 6 to fill the first tube 5a with air pressure.

  An air pressure switching unit 7 is incorporated in each wheel 2. As shown in FIGS. 2 and 3, the air pressure switching unit 7 includes a first air passage 8a that communicates between the first air chambers 5s and 5s, and a communication between the first air passage 8a and the second air chamber 5e. It has the 2nd air passage 8b which carries out, and the channel switching part 9 inserted in this 2nd air passage 8b.

  The flow path switching unit 9 is provided with first and second air dividing passages 8c and 8d which divide the middle of the second air passage 8b into two forks. The air dividing passages 8c and 8d are arranged in the opposite directions. A pair of first and second one-way valves 9a and 10b that are arranged are respectively interposed. Although not shown, the first air passage 8a and the second air passage 8b on the second tube 5b side are communicated with each other through a bypass passage, and a normally closed bypass valve is provided in this bypass passage. There is.

  The first one-way valve 9a allows only the outflow of air pressure from the second tube 5b to the second tube 5a, while the second one-way valve 9b allows only the inflow of air pressure from the first tube 5a to the second tube 5b. To do.

  Further, each of the air dividing passages 8c and 8d is selectively communicated with the second air passage 8b on the side communicating with the first air passage 8a through the two-position switching valve 10 so that the air pressure distribution direction is changed. Can be switched. The 2-position switching valve 10 is a 4-port latch (self-holding) double solenoid valve, and is switched by a drive signal (one-shot pulse) from a control unit 21 described later.

  Further, the air valve 6 is provided with a chuck detection switch 11 as a connection detection means. The chuck detection switch 11 is turned on when the tire chuck provided on the air inflator is attached to the air valve 6, and turned off when the tire chuck is removed. Although the above-described air pressure switching unit 7 is shown incorporated in the tire wheel 3, it may be incorporated in the tire 4.

  The control unit 21 is mainly composed of a microcomputer and has a well-known CPU, ROM, RAM, non-volatile memory, etc., and various programs executed by the CPU, fixed data, etc. are stored in the ROM. There is. The chuck detection switch 11 and the ground mode selection switch 12 are connected to the input side of the control unit 21. The grounding mode selection switch 12 is a dual switch having a drivability (drivability) mode switch 12a and an economy tire (hereinafter referred to as "eco tire") mode switch 12b, and is provided adjacent to the steering wheel and its periphery. Any one of them is selected by the switch operation of the operator (mainly the driver). In this case, the ground mode selection switch 12 may be a touch switch displayed on the monitor.

  Two signal lines extending from the two-position switching valve 10 and a signal line extending from the chuck detection switch 11 are connected to the control unit 21 via a slip ring 13 arranged at the rotation center of the wheel 2. Has been done. The air pressure of each tire 4 is set to a specified pressure, and each tire 4 is filled with the specified air pressure using an air inflator.

  Further, when the drivability mode switch 12a provided in the grounding mode selection switch 12 is turned on, the first solenoid 10a of the two-position switching valve 10 is caused to project, and the first air splitting in which the first one-way valve 9a is interposed. The passage 8c is communicated with and cuts off the second air dividing passage 8d in which the second one-way valve 9b is interposed. On the other hand, when the eco-tire mode switch 12b is turned on, the second solenoid 10b of the two-position switching valve 10 is caused to project so as to communicate with the second air dividing passage 8d in which the second one-way valve 9b is interposed and the first one-way. The first air division passage 8c in which the valve 9a is interposed is shut off.

  The tire ground contact mode switching executed by the control unit 21 described above is specifically processed according to the tire ground contact mode setting routine shown in FIG.

  In this routine, first, in step S1, it is checked whether or not switch signals from the mode switch portions 12a and 12b of the ground mode selection switch 12 are detected. If detected, the process proceeds to step S2, or is not detected. If you exit the routine.

  When the process proceeds to step S2, when the drivabilty mode switch 12a is ON, that is, when the drivabilty mode is selected as the tire ground contact mode, the process proceeds to step S3. On the other hand, when the eco-tire mode switch 12b is ON, that is, when the eco-tire mode is selected as the tire ground contact mode, the process proceeds to step S4.

  When the process proceeds to step S3, the tire ground contact mode is set to the drabli mode and the routine is exited. On the other hand, if the process proceeds to step S4, the tire ground contact mode is set to the eco tire mode and the routine is exited.

  In the drive mode of step S3, the control unit 21 outputs a one-shot pulse to the first solenoid 10a of the two-position switching valve 10. Then, as shown in FIG. 2, the first solenoid 10a is driven to communicate the first air dividing passage 8c with the first air passage 8a and the second air dividing passage 8d.

  When the tire 4 is running, the internal pressure of the tire 4 is constantly changed by an external force such as unevenness of the road surface. When the second tube 5b is pressed from the surroundings, the air pressure filled in the second air chamber 5e is changed to the first one-way valve 9a. And is gradually sent to the first air chamber 5s of the first tube 5a arranged on both sides thereof.

  As a result, the air pressure of the first air chamber 5s becomes relatively higher than the air pressure of the second air chamber 5e, and as shown in FIG. 5, the ground contact area of the tread portion of the tire 4 with respect to the road surface becomes wider, and accordingly, Tire grip power is increased, and steering stability and braking performance are improved.

  On the other hand, in the eco-tire mode of step S4, the control unit 21 outputs a one-shot pulse to the second solenoid 10b of the two-position switching valve 10. Then, as shown in FIG. 3, the second solenoid 10b is driven to communicate the second air division passage 8d with the first air passage 8a and to block the first air division passage 8c.

  When the vehicle 1 is run in this state, the first tube 5a is pressed from the surroundings due to the change in the internal pressure applied to the tire 4, and the air pressure filled in the first tube 5a passes through the second one-way valve 9b, and It is gradually fed to the second tube 5b sandwiched between the first tubes 5a. As a result, the air pressure of the second tube 5b becomes relatively high, and as shown in FIG. 6, the ground contact area of the tread portion of the tire 4 with respect to the road surface becomes narrower, so that the rolling resistance is reduced and fuel consumption is improved. be able to.

  When a driver or the like attaches a tire chuck provided on the air inflator to the air valve 6 in order to replenish the tire 4 with air pressure, the chuck detection switch 11 is turned on. When the control unit 21 detects this ON signal, the control unit 21 is of a normally closed type that is interposed in a bypass passage that connects the first air passage 8a and the second air passage 8b on the second air chamber 5e side. Open the valve. Then, the first and second air chambers 5s and 5e are communicated with each other through the bypass passage, and the air pressures of the tubes 5a and 5b (both air chambers 5s and 5e) become substantially equal.

  In this state, both tubes 5a and 5b (both air chambers 5s and 5e) are filled with a prescribed air pressure from the air inflator. Then, when the tire chuck is removed from the air valve 6 after the tire 4 has been filled with the prescribed air pressure to a predetermined value, the chuck detection switch 11 is turned off, and the control unit 21 closes the bypass valve to cause the tubes 5a to close. , 5b (both air chambers 5s, 5e) are disconnected from each other.

  As described above, according to the present embodiment, the tire 4 is divided into three chambers, that is, the first air chambers 5s on both sides and the second air chambers 5e sandwiched by the first air chambers 5s. The air chamber 5s and the second air chamber 5e are connected to each other by the first and second air passages 8a and 8b, and the flow passage switching unit 9 is interposed in the second air passage 8b. When the drivability mode is selected as the tire grounding mode by the switching operation, the air pressure of the second air chamber 5e is sent to the first air chamber 5s by utilizing the change in the external force applied to the tire 4 during traveling, and the eco tire When the mode is selected, the air pressure of the first air chamber 5s is sent to the second air chamber 5e via the flow path switching unit 9 to change the ground contact area of the tread portion of the tire 4. With a simple structure without using a complicated link mechanism, it is possible to easily change the ground contact area of the tread portion of the tire 4 during traveling, and it is possible to simplify the structure.

  Further, since a complicated link mechanism for varying the air pressure is not required, the weight applied to each wheel 2 does not increase remarkably, the increase in rolling resistance is suppressed, and the deterioration of fuel consumption can be prevented accordingly.

Further, when the air pressure is replenished to the tire 4 using the air inflator, the air chambers 5s and 5e are made to communicate with each other, so that the air pressure can be replenished to the air chambers 5s and 5e evenly. 2 Embodiments]
7 and 8 show a second embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

  The flow path switching unit 9 of the above-described first embodiment switches the two-position switching valve 10 to switch the first and second air division passages 8c and 8d to the second by depending on whether the tire ground contact mode is the drabli mode or the eco mode. It is designed to be selectively connected to the air passage. On the other hand, the flow path switching unit 9 of the present embodiment replaces the two-position switching valve 10 with the first and second valves on the second air passage 8b side of the first and second air dividing passages 8c and 8d. 15a and 15b are respectively interposed, and the first and second air dividing passages 8c and 8d are selectively connected to the second air passage by opening and closing the valves 15a and 15b.

  Further, in this embodiment, a pre-startup inspection switch (hereinafter, simply referred to as “inspection switch”) 14 is connected to the control unit 21. The inspection switch 14 is turned on by a driver or the like to self-check various check items such as maintenance, inspection, and diagnosis that are preset before starting. Includes tire pressure check. The air pressure is detected by an air pressure sensor provided in either or both of the first and second air chambers 5s and 5e.

  Next, the tire ground contact mode switching operation executed by the control unit 21 will be described in accordance with the tire ground contact mode setting routine shown in FIG.

  In this routine, first, in step S21, it is checked whether or not the switch signals from the chuck detection switch 11, the mode switch portions 12a and 12b of the ground mode selection switch 12, and the inspection switch 14 are detected. , Proceeds to step S22, and if not detected, exits the routine.

  In step S22, it is checked whether or not at least one of the chuck detection switch 11 and the inspection switch 14 is ON. When the chuck detection switch 11 is ON, the tire chuck of the air inflator is attached to the air valve 6 and the air pressure is filled, and when the inspection switch 14 is ON, the self-check before starting is performed. Executed.

  Then, when at least one of the chuck detection switch 11 and the inspection switch 14 is ON, the process branches to step S23, the first and second valves 15a and 15b are both opened, and the routine is exited.

  When both the first and second valves 15a and 15b are opened, the flow of air into and out of the second air chamber 5e of the second tube 5b becomes free, and the first air chamber 5s of the first tube 5a and the second tube 5e. Since the second air chamber 5e of 5b is communicated with, the first and second air chambers 5e, 5s can be filled with a prescribed air pressure via the air valve 6 as in the first embodiment. Furthermore, the air pressure in the tire 4 before starting can be self-checked.

  On the other hand, if it is determined in step S22 that both the chuck detection switch 11 and the inspection switch 14 are OFF, the process proceeds to step S24 to check whether or not the currently set tire grounding mode is the drabiri mode. Proceed to S25. In the case of the eco tire mode, the process proceeds to step S26.

  When the process proceeds to step S25, the first valve 15a is opened and the second valve 15b is closed in order to execute the drive mode, and the routine is exited. Then, the air pressure filled in the second air chamber 5e of the second tube 5b due to the change in the internal pressure of the tire 4 due to the vibration during traveling causes the first one-way valve 9a interposed in the first air dividing passage 8c. It is pushed up, passes through the first valve 15a, and is gradually sent to the first air chamber 5s of the first tube 5a to relatively increase the air pressure of the first air chamber 5s as shown in FIG.

  Further, when the process proceeds to step S26, the first valve 15a is closed and the second valve 15b is opened to execute the eco-tire mode, and the routine is exited. Then, due to the change in the internal pressure of the tire 4 during traveling, the air pressure filled in the first air chamber 5s of the first tube 5b passes through the second valve 15b and pushes up the second one-way valve 9b, and the second tube 5b. Flowing into the second air chamber 5e to relatively increase the air pressure in the second air chamber 5e as shown in FIG.

  As described above, in this embodiment, instead of the two-position switching valve 10 of the first embodiment, the first and second valves 15a and 15b are provided in the first and second air dividing passages 8c and 8d, Since the flow of air pressure is controlled, the structure can be simplified and good controllability can be obtained as compared with the first embodiment.

  Further, by opening both the first and second valves 15a and 15b, the air chambers 5s and 5e can be communicated with each other regardless of the currently set tire grounding mode (drivability mode or eco-tire mode). The air pressure can be easily filled from the air valve 6.

  The present invention is not limited to the above-described embodiments, and the tire 4 may be, for example, a tubeless tire instead of a tube tire. In this case, each of the air chambers 5s and 5e is defined by a partition wall integrally formed in the circumferential direction of the tire 4.

  Further, the air valve 6 may be attached to the second tube 5b so as to communicate with the second air chamber 5e. Furthermore, in a vehicle having a driving mode that emphasizes driving force and an eco mode that emphasizes fuel efficiency, in addition to the normal mode suitable for normal driving, the tire grounding mode may be linked to this driving mode. good. In this case, for example, in the normal mode, the driver can selectively set either the dribiri mode or the eco-tire mode, and the drivabili mode in the sports mode and the eco-tire mode in the eco mode are linked. Further, the inspection switch 14 shown in the second embodiment may be provided in the pneumatic pressure varying device of the first embodiment.

1 ... vehicle,
4 ... tires,
5a ... the first tube,
5b ... second tube,
5e ... second air chamber,
5s ... 1st air chamber,
6 ... Air valve,
7 ... Air pressure switching unit,
8a ... the first air passage,
8b ... second air passage,
8c ... first air dividing passage,
8d ... second air dividing passage,
9 ... Flow path switching unit,
9a ... first one-way valve,
9b ... second one-way valve,
10 ... 2 position switching valve,
10a ... the first solenoid,
10b ... second solenoid,
11 ... Chuck detection switch,
12 ... Grounding mode selection switch,
12a ... Drabili mode switch,
12b ... Eco-tire mode switch,
13 ... slip ring,
14 ... Pre-start inspection switch,
15a ... the first valve,
15b ... second valve,
21 ... Control unit

Claims (5)

A pair of first air chambers provided on both sides in the tire width direction,
A second air chamber sandwiched between the first air chambers and provided in the center in the tire width direction;
A first air passage communicating between the first air chambers,
A second air passage communicating the second air chamber with the first air passage;
It is interposed in the second air passage, and selectively selects an air pressure distribution direction from the second air chamber to the first air passage and an air pressure distribution direction from the first air passage to the second air chamber. A flow path switching unit to be set,
A control unit for controlling the switching operation of the flow path switching unit,
As a tire grounding mode, it has a wide contact area drabili mode and a narrow contact area eco-tire mode,
The control unit sets the flow direction of the air pressure of the flow path switching unit to the flow from the second air chamber to the first air passage when the dribery mode is selected as the tire grounding mode, and the eco-tire. An air pressure varying device for a vehicle tire, characterized in that when a mode is selected, the flow is set to flow from the first air passage to the second air chamber. 2. The tire pressure varying device for a vehicle tire according to claim 1, wherein the tire grounding mode is selected by operating a grounding mode selection switch. It has a sports mode that emphasizes driving force and an eco mode that emphasizes fuel efficiency as the driving modes of the vehicle.
The control unit sets the tire grounding mode to the drabli mode when the sports mode is selected as the traveling mode, and sets the tire grounding mode when the eco mode is set as the traveling mode. The air pressure varying device for a vehicle tire according to claim 1, wherein the eco tire mode is set. Connection detection means is provided for detecting attachment of a valve connector provided in an air pressure source to an air valve communicating with at least one of the first air chamber and the second air chamber,
The control unit causes the first air chamber and the second air chamber to communicate with each other when the connection detection unit detects the connection of the valve connector to the air valve. Item 1. A vehicle tire air pressure varying device according to item 1. An inspection switch is connected to the control unit,
5. The control unit causes the first air chamber and the second air chamber to communicate with each other in order to check the tire air pressure when the inspection switch is turned on. 5. A vehicle tire air pressure varying device according to.

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