JP2017154648A - Tire air pressure alarm device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire air pressure alarm device for a vehicle capable of achieving enhancement of both of longevity and detection accuracy.SOLUTION: A tire air pressure alarm device 1 for a vehicle V comprises a wheel side unit 20, disposed inside a tire 4, including: a pressure sensor 21 for detecting a pressure of air in the tire 4; a temperature sensor 22 for detecting a temperature of the air in the tire 4; a power generating part 23 for converting energy associated with a rolling motion of the tire 4 to generate electric power; a power storage part 24 for storing electric power generated by the power generating part 23; and a transmission part 25 for transmitting information detected by the sensors 21 and 22 to a vehicle body side unit 10. The air pressure sensor 21 is exposed to a tire air chamber 6, while the power generating part 23 is embedded in an inner wall 4a of the tire 4 so as to be more isolated from the tire air chamber 6 than the air pressure sensor 21. The power storage part 24 is arranged so as to be adjacent to the air pressure sensor 21 and the power generating part 23 in an axial direction of the tire 4.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tire pressure alarm device for a vehicle, and more particularly to a vehicle tire in which a sensor unit including a pressure detection means for detecting tire air pressure and a transmission means for transmitting detected information is disposed inside the tire. The present invention relates to a pneumatic alarm device.

Conventionally, an air pressure alarm device (Tire Pressure Monitoring) that includes a pressure detection means for detecting tire air pressure inside the tire and a transmission means for transmitting information such as detected air pressure, and is capable of detecting tire air pressure abnormality. System: TPMS) is known.
When the tire air pressure is higher than the appropriate value, the riding feeling deteriorates due to the trumping phenomenon and the tire wears faster, and when the tire air pressure is lower than the appropriate value, the steering operability is lowered. In addition, fuel consumption deteriorates.
Therefore, it is important to maintain the tire air pressure at an appropriate level, and TPMS equipment is required in some countries.

  The wheel state acquisition device of Patent Document 1 includes a wheel side sensor unit including a tire pressure sensor, a tire air temperature sensor, and a communication device capable of transmitting the detection information, a tire pressure sensor, and a tire temperature sensor. A tire-side sensor unit capable of outputting the detection information to a communication device of the wheel-side sensor unit via a wire, the wheel-side sensor unit being attached to an air valve mounted on the wheel, and the tire-side sensor unit being a tire-side sensor unit. It is buried in the inner wall.

JP 2006-076417 A

In general, in TPMS, a sensor unit installed on a wheel is positioned and fixed to an air valve or a wheel via a predetermined mounting bracket or the like. Therefore, the number of parts increases, and there is a problem to be solved in terms of productivity such as manufacturing cost and installation work by an operator.
In addition, since the communication device and the battery configured by the transmission circuit and the transmission antenna are exposed to the air filled in the tire, there is a risk of being affected by corrosion due to moisture or the like, and shortening the life. is there.

It is also conceivable to embed a sensor unit for detecting the air pressure in the tire air chamber in the tire inner wall as in the tire side sensor unit of the wheel state acquisition device of Patent Document 1.
However, since the space from the so-called groove bottom of the tire to the inner space side end of the inner wall is about 10 to 12 mm, the sensor unit can be placed on the inner wall of the tire so as not to be exposed to air. Embedding is not physically easy.
On the other hand, by embedding the sensor unit as a whole in the inner wall of the tire, the effects of corrosion can be avoided, but the air pressure in the tire air chamber cannot be measured directly, ensuring sufficient sensor detection accuracy. There is a possibility that it cannot be done.

  An object of the present invention is to provide a tire pressure alarm device for a vehicle that can achieve both a long service life and detection accuracy of a sensor unit.

  The tire pressure alarm device for a vehicle according to claim 1 is provided with a sensor unit including pressure detecting means for detecting air pressure of the tire and transmitting means for transmitting information detected by the pressure detecting means. In the vehicle tire air pressure warning device, the sensor unit includes power generation means for generating energy by converting energy associated with rolling of the tire, and power storage means for storing electric power generated by the power generation means, The pressure detection means is exposed in the internal space of the tire, and the power generation means is embedded in the inner wall portion of the tire so as to be farther from the internal space than the pressure detection means.

  In this tire pressure alarm device for a vehicle, the sensor unit has power generation means for converting the energy accompanying rolling of the tire to generate electric power and power storage means for storing the electric power generated by the power generation means. The tire air pressure can be stably measured and transmitted without occurring. Since the pressure detection means is exposed to the tire internal space and the power generation means is embedded in the inner wall of the tire so as to be separated from the internal space rather than the pressure detection means, members other than the pressure detection means are exposed to the tire internal space. Without this, the pressure detection means can be exposed to the internal space of the tire to ensure the accuracy of detecting the air pressure.

The invention of claim 2 is characterized in that, in the invention of claim 1, the sensor unit has a temperature detecting means for detecting an air temperature in the internal space.
According to this configuration, the temperature of the air pressure can be corrected by the air temperature in the internal space, and the detection accuracy can be further improved.
A third aspect of the invention is characterized in that, in the second aspect of the invention, the temperature detecting means is exposed in an internal space of the tire.
According to this configuration, the temperature detection means can be exposed to the internal space of the tire to ensure the air temperature detection accuracy.

The invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the power generation means converts vibration or pressure change accompanying rolling of the tire into electric power.
According to this configuration, it is possible to generate electric power for driving the transmission unit and the like when the vehicle that needs to detect air pressure travels.

According to a fourth aspect of the present invention, in the first aspect of the present invention, at least one of the transmission unit and the power storage unit is disposed between the pressure detection unit and the power generation unit. It is characterized by that.
According to this structure, the dimension of the direction which cross | intersects the tire radial direction of a sensor unit can be shortened.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fifth aspects, at least one of the transmission unit and the power storage unit is provided in the circumferential direction or the axial direction of the tire to the pressure detection unit and the power generation unit. It is characterized by being arranged adjacent to each other.
According to this configuration, the sensor unit can be reduced in size.

  According to the tire pressure alarm device for a vehicle of the present invention, it is possible to achieve both the long life of the sensor unit and the detection accuracy.

1 is a schematic diagram of a vehicle equipped with a tire pressure alarm device according to a first embodiment. It is a principal part longitudinal cross-sectional view of a wheel. FIG. 3 is an enlarged view of a main part of FIG. 2. It is the IV-IV sectional view taken on the line of FIG. It is a perspective view of a sensor unit. It is a block diagram of a sensor unit. 6 is a perspective view of a sensor unit according to Embodiment 2. FIG. FIG. 4 is a diagram corresponding to FIG. 3. It is the IX-IX sectional view taken on the line of FIG. FIG. 6 is a view corresponding to FIG. 3 according to a third embodiment. FIG. 6 is a diagram corresponding to FIG. 3 according to a fourth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies the application of the present invention to a tire pressure alarm device for a vehicle, and does not limit the present invention, its application, or its use.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a tire pressure alarm device 1 is mounted on a vehicle V of the present invention.
The tire pressure alarm device 1 includes a vehicle body side unit 10 and four wheel side units 20 (sensor units) mounted for each wheel 2.
Hereinafter, in the figure, the arrow F direction is assumed to be the front, the arrow L direction is assumed to be the left, and the arrow U direction is assumed to be the upper side.

  As shown in FIG. 2, two pairs of front and rear wheels 2 include a metal wheel 3 connected to the vehicle body via a suspension (not shown), and a rubber tire fixed to a rim portion 3 a of the wheel 3. 4 etc., respectively. Since each wheel 2 is configured in the same manner, the left front wheel (wheel 2) will be mainly described as an example.

An air valve 5 capable of injecting pressurized air into a ring-shaped tire air chamber 6 (internal space) is provided on the side of the wheel 3.
The tire 4 is composed of a pair of left and right sidewalls extending radially outward and a tread that connects the outer peripheral edges of the pair of sidewalls. A bead wire made of a bundle of steel wires is housed in a portion of the sidewall that contacts the rim portion 3a.
The tread is formed with a plurality of groove portions 4a having a predetermined depth along the entire outer periphery, and an inner wall portion 4b made of a ring-shaped rubber lump between the bottom portion of the groove portions 4a and the contact portion with the tire air chamber 6. Is formed.

First, the vehicle body side unit 10 will be described.
As shown in FIG. 1, the vehicle body side unit 10 includes an ECU (Electronic Control Unit) 11, an antenna 12 electrically connected to the ECU 11, an alarm device 13, and the like.
The ECU 11 compares the detected air pressure of each tire air chamber 6 with a predetermined reference pressure during traveling of the vehicle V, so that when the air pressure of any tire air chamber 6 falls below the reference pressure, An abnormality in the air pressure of the tire 4 is determined and notified.
Here, the predetermined reference pressure is, for example, a determination pressure obtained through experiments or the like that may cause a reduction in air performance by a certain rate due to a decrease in air pressure.
The reference pressure is corrected based on the detected air temperature of each tire air chamber 6 when determining the air pressure.

The ECU 11 includes a CPU (Central Processing Unit), a ROM, a RAM, an in-side interface, an out-side interface, and the like.
Various programs and data for determining air pressure abnormality are stored in the ROM, and a processing area used when the CPU performs a series of processes is provided in the RAM.
The antenna 12 receives the detected pressure value and the detected temperature value of the tire air chamber 6 transmitted from each wheel side unit 20, and outputs them to the ECU 11.
The alarm device 13 includes a warning lamp, a buzzer, a display, or the like, and is configured to notify an occupant of an abnormal air pressure state based on a determination result of the ECU 11.

Next, the four wheel side units 20 attached to each wheel 2 will be described.
Since the four wheel side units 20 mounted on each wheel 2 are configured in the same manner, the wheel side unit 20 of the left front wheel will be mainly described as an example.
As shown in FIGS. 2, 3, and 4, the wheel side unit 20 is embedded in the inner wall portion 4 b in a state of being partially exposed to the tire air chamber 6.
The wheel side unit 20 is preliminarily disposed in an injection mold for the tire 4 and then fixed at a predetermined accommodation position in the tire 4 by injecting a molten rubber material.

  As shown in FIGS. 3 to 6, the wheel side unit 20 includes a pressure sensor 21 (pressure detection unit), a temperature sensor 22 (temperature detection unit), a power generation unit 23 (power generation unit), and a power storage unit 24 (power storage). Means), the transmission unit 25 (transmission means), the case 26 (covering means) and the like are integrated as a single component.

The pressure sensor 21 is formed such that the lower end side surface portion (the inner end surface portion in the radial direction of the tire 4) is partially exposed to the tire air chamber 6.
The pressure sensor 21 is, for example, a diaphragm type sensor having a stress application surface, a so-called pressure-sensitive conductive rubber whose resistance value changes in inverse proportion to air pressure applied from outside, and a switch element on both sides of the switch element. The pressure is measured by sandwiching between a pair of electrodes and measuring a change in resistance value therebetween. And the lower end side part of the pressure sensor 21 is arrange | positioned below (diameter direction inner side) rather than the lower end side part (diameter direction inner end surface part) of the inner wall part 4b.
The temperature sensor 22 is provided adjacent to the pressure sensor 21 so as to be adjacent to the front and rear, and similarly to the pressure sensor 21, the lower end side surface portion is formed to be partially exposed to the tire air chamber 6.

As shown in FIGS. 3 and 4, the power generation unit 23 is located above the pressure sensor 21 and the temperature sensor 22 (outside in the radial direction of the tire 4) so as to be farther from the tire air chamber 6 than the pressure sensor 21 and the temperature sensor 22. Are arranged so as to overlap each other in a slightly separated state. The power generation unit 23 is formed such that the upper end side surface portion (the outer end surface portion in the radial direction of the tire 4) is exposed in the inner wall portion 4b and is in direct contact with the inner wall portion 4b.
The power generation unit 23 is configured by a piezoelectric element that converts energy accompanying rolling of the tire 4 to generate power, for example, a piezo element that is a ferroelectric.
Therefore, the power generation unit 23 performs a power generation operation by repeating the deformation that is compressed and deformed when the upper side surface portion enters the contact area of the tire 4 and returns to the shape when the upper end side surface part separates from the contact area.

The AC voltage generated by the power generation unit 23 is stored in the power storage unit 24.
The power storage unit 24 is parallel to the axial direction of the tire 4 of the pressure sensor 21 (temperature sensor 22) and the power generation unit 23 and is adjacent to the pressure sensor 21 (temperature sensor 22) and the power generation unit 23 at a position near the left side. Is arranged.
The power storage unit 24 includes a rectification mechanism using an AC / DC converter that converts an AC voltage into a DC voltage, a transformation mechanism that includes a DC / DC converter that converts the rectified voltage into a predetermined voltage, and a transformed voltage. The battery is equipped with a storage mechanism such as a lithium ion battery.

As shown in FIG. 6, the transmission unit 25 includes a transmission circuit 25a and an antenna 25b. The transmitter 25 transmits the pressure value and temperature value of the tire air chamber 6 detected by the pressure sensor 21 and the temperature sensor 22 to the antenna 12.
The transmission circuit 25a includes, for example, an amplifier that amplifies the detection values detected by the pressure sensor 21 and the temperature sensor 22 to a predetermined level, a switch mechanism that outputs a signal amplified by the amplifier, and the switch mechanism in advance. An operating mechanism that operates at set intervals is provided, and the identification ID code set for each wheel 2 and the pressure value and temperature value of the tire air chamber 6 are output to the vehicle body side unit 10 from the antenna 25b.

Next, the case 26 will be described.
The case 26 is formed of a synthetic resin, for example, acrylic resin, and covers the outer surfaces of the sensors 21 and 22 and the respective parts 23 to 25 except for the lower side surfaces of the pressure sensor 21 and the temperature sensor 22 and the upper side surface of the power generation unit 23. It is comprised so that it may coat | cover.
The case 26 includes a rectangular upper wall portion 26a, a rectangular lower wall portion 26b parallel to the upper wall portion 26a, and front and rear side wall portions 26c that connect the upper wall portion 26a and the lower wall portion 26b. It is formed in a cubic structure.

  As shown in FIGS. 3 and 4, the upper wall portion 26 a has a rectangular opening through which the power generation unit 23 can be inserted, and is disposed on the lower side (in the radial direction) than the upper end side surface portion of the power generation unit 23. ing. Therefore, the upper end side portion of the power generation unit 23 and the upper end side portions of the front, rear, left and right side portions are in direct contact with the inner wall portion 4b. The lower wall portion 26b has a rectangular opening through which the pressure sensor 21 and the temperature sensor 22 can be inserted. The vertical wall portion 26d has a rectangular shape in a plan view, and a vertical wall portion at a position near the vertical wall portion 26d. The step part 26e which continues to 26d is provided.

The vertical wall portion 26 d is formed so as to extend downward from the lower wall portion 26 b corresponding to the periphery of the pressure sensor 21 and the temperature sensor 22.
The lower end portion of the vertical wall portion 26d is disposed below the lower end side surface portions of the pressure sensor 21 and the temperature sensor 22, and is formed so as to be exposed to the tire air chamber 6.
The step portion 26e is connected to the upper end portion of the vertical wall portion 26d and is formed so as to be substantially orthogonal to the vertical wall portion 26d. Thereby, the lower wall part 26b and the level | step difference part 26e are embed | buried in the inner wall part 4b.

The front, rear, left and right side wall portions 26 c are arranged so as to be substantially parallel to the radial direction of the tire 4. As shown in FIGS. 3 to 5, the front and rear, left and right side wall portions 26 c are uniformly formed with engaging portions 26 f that are convex over the entire circumference in the middle step and have a substantially rectangular cross section.
Since the inner wall portion 4b is disposed below the engaging portion 26f and the inner wall portion 4b is disposed below the step portion 26e, the engaging portion 26f and the step portion 26e are connected to the tire air of the wheel side unit 20. This corresponds to a fall prevention mechanism for preventing the fall into the chamber 6.

Next, the operation and effect of the tire pressure alarm device 1 will be described.
According to the tire pressure alarm device 1, the wheel side unit 20 includes a power generation unit 23 that generates energy by converting energy associated with rolling of the tire 4, and a power storage unit 24 that accumulates the power generated by the power generation unit 23. Therefore, the air pressure of the tire 4 can be stably measured and transmitted without causing power shortage. Since the pressure sensor 21 is exposed to the tire air chamber 6 and the power generation unit 23 is embedded in the inner wall portion 4a of the tire 4 so as to be farther from the tire air chamber 6 than the pressure sensor 21, members other than the pressure sensor 21 are used as tires. Without being exposed to the air chamber 6, the pressure sensor 21 can be exposed to the tire air chamber 6 to ensure air pressure detection accuracy.

  Since the wheel side unit 20 has the temperature sensor 22 that detects the air temperature of the tire air chamber 6, the air pressure can be corrected by the air temperature of the tire air chamber 6, and the detection accuracy can be further improved. . Further, since the temperature sensor 22 is exposed to the tire air chamber 6, the temperature sensor 22 can be exposed to the tire air chamber 6 to ensure air temperature detection accuracy.

Since the power generation unit 23 converts the vibration or pressure change accompanying the rolling of the tire 4 into electric power, it is possible to generate electric power for driving the transmission unit 25 and the like when the vehicle V that needs to detect air pressure travels. .
Since the power storage unit 24 is disposed adjacent to the pressure sensor 21 (temperature sensor 22) and the power generation unit 23 in the axial direction of the tire 4, the wheel side unit 20 can be reduced in size.

Next, the wheel side unit 20A according to the second embodiment will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the member similar to Example 1. FIG.
In the first embodiment, the pressure sensor 21 (temperature sensor 22) is disposed so as to directly face the power generation unit 23, whereas in the second embodiment, the pressure sensor 21A is stored between the power generation unit 23A and the power generation unit 23A. It arrange | positions so that the part 24A may be interposed.

  As shown in FIGS. 7 to 9, the wheel side unit 20A includes a pressure sensor 21A, a temperature sensor 22A, a power generation unit 23A, a power storage unit 24A, a transmission unit 25A, a case 27, and the like. It is configured as one part.

  The pressure sensor 21 </ b> A is formed such that the lower side surface portion is partially exposed to the tire air chamber 6. The lower end side surface portion of the pressure sensor 21A is disposed below the lower end side surface portion of the inner wall portion 4b. The temperature sensor 22A is provided adjacent to the pressure sensor 21A so as to be adjacent to the front and rear, and is formed so that the lower end side surface portion is partially exposed to the tire air chamber 6 in the same manner as the pressure sensor 21A.

As shown in FIGS. 8 and 9, the power generation unit 23A is disposed above the pressure sensor 21A and the temperature sensor 22A so as to be separated from the tire air chamber 6 relative to the pressure sensor 21A and the temperature sensor 22A. The power generation portion 23A is formed so that the upper end side surface portion is exposed in the inner wall portion 4b and is in direct contact with the inner wall portion 4b.
The power storage unit 24A is interposed between the pressure sensor 21A (temperature sensor 22A) and the power generation unit 23A. The transmitting unit 25A is arranged to be parallel to the axial direction of the tire 4 and adjacent to the power storage unit 24A at a position near the left side.

Next, the case 27 will be described.
The case 27 is configured to cover the entire outer surface of the sensors 21A, 22A and the respective portions 23A, 24A, 25A except for the lower end side surface portions of the pressure sensor 21A and the temperature sensor 22A and the upper end side surface portion of the power generation unit 23A. Yes.
The case 27 includes a circular upper wall portion 27a, a circular lower wall portion 27b parallel to the upper wall portion 27a, and a cylindrical side wall portion 27c that connects the upper wall portion 27a and the lower wall portion 27b. It is formed into a cylindrical structure.

As shown in FIGS. 7 to 9, the upper wall portion 27 a has a semicircular opening through which the power generation unit 23 </ b> A can be inserted, and is disposed below the upper end side surface portion of the power generation unit 23 </ b> A. 27b has a semicircular opening through which the pressure sensor 21A and the temperature sensor 22A can be inserted, and is arranged above the lower end side surface of the pressure sensor 21A and the temperature sensor 22A.
The side wall portion 27c is disposed so that its axial center is substantially parallel to the radial direction of the tire 4, and an engaging portion 27f having a concave shape and a rectangular cross section is formed uniformly in the middle step portion. Has been.
The lower wall portion 27b and the engaging portion 27f supported by the inner wall portion 4b correspond to a fall prevention mechanism that prevents the wheel side unit 20A from falling into the tire air chamber 6.

Since the wheel side unit 20A according to the second embodiment is disposed so that the power storage unit is interposed between the pressure sensor 21A (temperature sensor 22A) and the power generation unit 23A, the diameter of the tire 4 of the wheel side unit 20A. The dimensions in the axial direction and the circumferential direction that intersect the direction can be shortened.
Further, since the transmission unit 25A is disposed adjacent to the pressure sensor 21A and the power generation unit 23A in the axial direction of the tire 4, the wheel side unit 20A can be reduced in size.

Next, the wheel side unit 20B according to the third embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the member similar to Example 1,2.
In the second embodiment, the engagement portion 27f having a concave shape and a rectangular cross section is formed on the side wall portion 27c, whereas in the third embodiment, the engagement portion 28f having a convex shape and a substantially triangular cross section is formed on the side wall portion 28c. Forming.

As shown in FIG. 10, the case 28 covers the entire outer surface of the sensors 21A, 22A and the respective portions 23A, 24A, 25A except for the lower end side portions of the pressure sensor 21A and the temperature sensor 22A and the upper end side portion of the power generation unit 23A. It is comprised so that it may coat | cover.
The case 28 includes a circular upper wall portion 28a, a circular lower wall portion 28b parallel to the upper wall portion 28a, and a cylindrical side wall portion 28c that connects the upper wall portion 28a and the lower wall portion 28b. It is formed into a cylindrical structure.

The side wall portion 28c is disposed so that its axial center is substantially parallel to the radial direction of the tire 4, and the engagement portion 28f that is convex over the entire circumference in the middle step portion and has a triangular cross section is uniform. Is formed.
The engaging portion 28f includes a tapered inclined surface portion 28g that shifts in the axial direction of the wheel side unit 20B as it moves upward (away from the tire air chamber 6). The lower end portion of the inclined surface portion 28g is connected to the side wall portion 28c in an orthogonal shape.
The lower wall portion 28b and the engaging portion 28f supported by the inner wall portion 4b correspond to a fall prevention mechanism that prevents the wheel side unit 20B from falling into the tire air chamber 6.

Next, the wheel side unit 20C according to the fourth embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the member similar to Examples 1-3.
In the third embodiment, the engagement portion 28f having a convex shape and a substantially triangular cross section is formed on the side wall portion 28c, whereas in the fourth embodiment, the engagement portion 29f having a concave shape and a substantially triangular cross section is formed on the side wall portion 28c. Is forming.

As shown in FIG. 11, the case 29 covers the entire outer surface of the sensors 21A, 22A and the respective portions 23A, 24A, 25A except for the lower end side portions of the pressure sensor 21A and the temperature sensor 22A and the upper end side portion of the power generation unit 23A. It is comprised so that it may coat | cover.
The case 29 includes a circular upper wall portion 29a, a circular lower wall portion 29b parallel to the upper wall portion 29a, and a cylindrical side wall portion 29c that connects the upper wall portion 29a and the lower wall portion 29b. It is formed into a cylindrical structure.

The side wall portion 29c is disposed so that its axial center is substantially parallel to the radial direction of the tire 4, and an engagement portion 29f having a concave shape and a triangular cross section is formed uniformly in the middle step portion. Has been.
The engaging portion 29f includes a tapered inclined surface portion 29g that moves in the axial direction of the wheel side unit 20C toward the upper side. The upper end portion of the inclined surface portion 29g is continuous with the side wall portion 28c. The lower wall portion 29b and the engaging portion 29f supported by the inner wall portion 4b correspond to a fall prevention mechanism that prevents the wheel side unit 20C from falling into the tire air chamber 6.

Next, a modified example in which the embodiment is partially changed will be described.
1] In the above-described embodiments, the pressure sensor, the temperature sensor, and the power generation unit have been described by way of example using a rectangular or semicircular schematic diagram for convenience of explanation. Can be selectively set.

2] In the first embodiment, the example in which the power storage unit is disposed adjacent to the pressure sensor (temperature sensor) and the power generation unit in the tire axial direction has been described, but the transmission unit is the pressure sensor, power generation unit, and tire axial direction. May be arranged adjacent to each other. It is also possible to arrange the pressure sensor and the power generation unit so as to be sandwiched between the power storage unit and the transmission unit in the tire axial direction.
Furthermore, at least one of the power storage unit and the transmission unit may be disposed adjacent to the pressure sensor (temperature sensor) and the power generation unit in the tire circumferential direction, and the power storage unit and the transmission unit in the tire circumferential direction are arranged with the pressure sensor (temperature sensor) and You may arrange | position so that an electric power generation part may be inserted | pinched.

3] In the second to fourth embodiments, the pressure sensor (temperature sensor) and the power generation unit sandwich the power storage unit. However, the pressure sensor and the power generation unit may be disposed so as to sandwich the transmission unit. It is also possible to interpose both the transmission unit and the transmission unit.

4) In the above embodiment, the example in which the melted rubber material is injected after the wheel side unit is arranged in advance in the tire injection mold is described. The wheel side unit may be attached to the tire after forming and applying the adhesive.
Moreover, when forming an accommodation recessed part, it is also possible to form a spiral groove part in the inner periphery of an accommodation recessed part, and to provide the helical engaging part which can be screwed together with a spiral groove part in the side wall part of a case.

5] In the above-described embodiment, the example in which the wheel side unit is mounted on the inner wall portion of the tire tread has been described. However, the wheel side unit may be mounted on the inner wall portion of the sidewall.
6) In addition, those skilled in the art can implement the present invention in various forms added with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

V Vehicle 1 Tire pressure warning device 4 Tire 4b Inner wall portion 6 Tire air chamber 20, 20A to 20C Vehicle side units 21, 21A Pressure sensors 22, 22A Temperature sensors 23, 23A Power generation units 24, 24A Power storage unit 25 Transmission unit

Claims (6)

In a tire pressure alarm device for a vehicle in which a sensor unit including a pressure detection means for detecting an air pressure of a tire and a transmission means for transmitting information detected by the pressure detection means is disposed inside the tire.
The sensor unit includes power generation means for generating energy by converting energy associated with rolling of the tire, and power storage means for storing electric power generated by the power generation means,
A vehicle tire characterized in that the pressure detection means is exposed in an internal space of the tire and the power generation means is embedded in an inner wall portion of the tire so as to be farther from the internal space than the pressure detection means. Pneumatic alarm device.   2. The vehicle tire pressure alarm device according to claim 1, wherein the sensor unit includes a temperature detecting means for detecting an air temperature in the internal space.   The vehicle tire pressure alarm device according to claim 2, wherein the temperature detecting means is exposed in an internal space of the tire.   The tire pressure alarm device for a vehicle according to any one of claims 1 to 3, wherein the power generation means converts vibration or pressure change accompanying rolling of the tire into electric power.   5. The vehicle according to claim 1, wherein at least one of the transmission unit and the power storage unit is disposed between the pressure detection unit and the power generation unit. Tire pressure alarm device.   The at least one of the transmission means and the power storage means is disposed so as to be adjacent to the pressure detection means and the power generation means in the circumferential direction or the axial direction of the tire. 2. A tire pressure alarm device for a vehicle according to item 1.