JPH10315720A - Pneumatic tire internal pressure detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire internal pressure detecting device that can be fitted to various different rims regardless of the shape of a well part while suppressing the increase of fitting cost. SOLUTION: A case 1 for enclosing a wireless sensor unit including air pressure sensor is fitted to a well part 12 of a rim 11, and this case 1 is held by a strap 6 annularly mounted on the well part 12 of the rim 11. In a pneumatic tire internal pressure detecting device of such constitution, the case 1 is composed of a cover part 2 to be mounted with the air pressure sensor, and a base part 3 interposed between the cover part 2 and the well part 12 of the rim 11, and the base part 3 can be replaced with one corresponding to the shape of the well part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for constantly detecting the internal pressure of a pneumatic tire. Related to the device.

[0002]

2. Description of the Related Art Conventionally, as a method of attaching a device for observing a tire air chamber state such as an air pressure sensor or a temperature sensor to a rim of a wheel, a sensor mounting hole is formed in the rim.
A sensor is inserted into this hole, or a valve stem and a sensor are integrally formed by using a valve stem mounting hole.

However, when the sensor mounting hole is provided in the rim as described above, there is a possibility that the original function of the rim, such as the strength and airtightness of the rim, may be reduced. Also, when the valve stem and the sensor are integrally configured, if the sensor circuit includes a control circuit such as a determination circuit and a battery, etc., the overall size increases, so at least the sensor portion is provided in the well portion of the rim. By arranging, the rim assemblability is secured while protecting the circuit. However, since the shape of the rim well and the distance from the valve mounting hole to the well portion vary depending on the design of the rim, it is necessary to prepare an extremely large number of variations corresponding to these.

Therefore, a case for accommodating a wireless sensor unit including an air pressure sensor is attached to the well of the rim, and the case is held by a metal band annularly mounted on the well of the rim. A device has been proposed. Such an internal pressure detecting device can be installed independently in the well portion of the rim independently of the valve stem.

However, in the above-described internal pressure detecting device, there is a problem that the case of the air pressure sensor cannot be attached when the well portion of the rim has a taper angle that is inclined with respect to the tire rotation axis. .
That is, in general, the air pressure sensor is composed of a diaphragm, and it is necessary to arrange the membrane surface of the diaphragm in the normal direction of the tire rotation axis in order to perform accurate detection, so that the arrangement angle cannot be easily changed. is there.
In addition, when the case of the air pressure sensor is adapted to the well shape, it is necessary to prepare an extremely large number of variations as in the case where the valve stem and the sensor are integrally formed, so that the mounting cost is greatly reduced. Will increase.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an internal pressure of a pneumatic tire which can be mounted on various rims regardless of the shape of a well portion while suppressing an increase in mounting cost. It is to provide a detection device.

[0007]

In order to achieve the above object, the present invention provides a pneumatic tire internal pressure detecting device in which a case accommodating a wireless type sensor unit including an air pressure sensor is attached to a well portion of a rim. In a device for detecting the internal pressure of a pneumatic tire, wherein a case is held by a strap mounted annularly on a well portion of the rim, a cover portion mounting the case at least the air pressure sensor, A base part interposed between the well part and the base part, and the base part can be exchanged according to the shape of the well part.

[0008] As described above, the case is composed of at least the cover portion on which the air pressure sensor is mounted, and the base portion interposed between the cover portion and the well portion of the rim, and the base portion conforms to the shape of the well portion. The internal pressure detecting device can be attached to various different rims regardless of the shape of the well portion by making it freely replaceable. Moreover,
According to the present invention, since only a plurality of types of bases of the case need to be prepared according to the shape of the well, the mounting cost is not significantly increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 9 show a pneumatic tire internal pressure detecting device according to an embodiment of the present invention. In the figure, a well portion 12 which is depressed in a radial direction is provided on an outer peripheral surface of a rim 11 in order to facilitate attachment and detachment of a tire.

A case 1 for housing a wireless sensor unit including an air pressure sensor is provided in a well 12 of the rim 11.
It is designed to be attached to. The air pressure sensor is composed of, for example, a diaphragm that detects air pressure,
The membrane surface of the diaphragm is vertically arranged in the case 1. The wireless sensor unit includes a pressure transducer, a control circuit, an oscillation circuit, a power supply, and the like. The result of the pressure detection by the air pressure sensor of the case 1 is wirelessly transmitted to an external display or the like.

The case 1 includes a cover 2 shown in FIGS. 5A to 5C, a base 3 shown in FIGS. 6A to 6C,
7A to 7C, and one of the bases 3 and 4 is combined with the cover 2 according to the shape of the well 12. ing. The cover 2 forms a box-shaped container, and has an air pressure sensor, a control circuit, and the like mounted therein. A pair of left and right hooks 2a is provided at both ends of the lower surface of the cover portion 2, and the pair of left and right hooks 2a engage with the base portions 3 and 4. Also, the cover 2
A groove 2b for placing a strap to be described later
Are formed.

On the other hand, each of the base portions 3 and 4 has a plate shape, and has a pair of batteries 5 mounted on its upper surface. Although the battery 5 can be mounted on the cover 2 side, it is preferably mounted on the bases 3 and 4 because it is relatively heavy. These base parts 3 and 4 are made of urethane resin,
It is made of a material having excellent workability, such as epoxy resin and engineering plastic, and having heat insulating properties.

Locking grooves 3a and 4a for locking the hooks 2a of the cover 2 are provided on the side surfaces of the bases 3 and 4, respectively. The lower surfaces of the base portions 3 and 4 are each formed in a curved shape so as to match the radius of curvature of the well portion 12 in a side view in a side view, and the taper of the well portion 12 in a tire rotation axis direction in a front view. It is shaped to match the angle. That is, the lower surface of the base portion 3 is inclined with respect to the tire rotation axis direction in a front view, and the lower surface of the base portion 4 is parallel to the tire rotation axis direction in a front view.

Next, a method of mounting the internal pressure detecting device configured as described above will be described. First, when the well portion 12 of the rim 11 has a taper angle as shown in FIG. 1, the base portion 3 whose lower surface is inclined is selected, and the well portion 12 has a taper angle as shown in FIG. If not, the base 4 whose lower surface is parallel to the tire rotation axis direction is selected, and the case 1 is assembled from one of the bases 3 and 4 and the cover 2.

The case 1 is attached to the well portion 12 by bonding the base portion 3 or 4 to the well portion 12 via a flexible double-sided heat-resistant tape. It is held by the wrapped strap 6. The strap 6 is made of a heat-resistant resin fiber such as nylon 6, nylon 66, aramid or the like as a plain woven material (textile). The strap 6 can be fixed by connecting both ends to each other by a known fastener (buckle). Further, the strap support 7 shown in FIGS. 8A to 8C is connected to the well portion 12 via a heat-resistant double-sided tape.
Alternatively, the strap support 8 shown in FIGS.
Are attached at predetermined intervals in the circumferential direction, and the strap support 7 or 8 holds the strap 6 in the rim width direction.

Grooves 7b and 8a for arranging the strap 6 are formed on the upper surfaces of the strap supports 7 and 8, respectively. The lower surfaces of the strap supports 7 and 8 are each formed substantially flat in a side view, and are formed so as to match the taper angle of the well portion 12 with respect to the tire rotation axis direction in a front view. That is, the lower surface of the strap support 7 is inclined with respect to the tire rotation axis direction in a front view, and the lower surface of the strap support 8 is parallel to the tire rotation axis direction in a front view. The strap supports 7 and 8 located on the opposite side of the case 1 are made of metal such as lead, and the strap supports 7 and 8 serve as counterweights 9 with respect to the weight of the case 1.
Is also used.

According to the internal pressure detecting device of the present invention described above,
The case 1 is composed of the cover 2 on which the air pressure sensor is mounted and the bases 3 and 4, and these bases 3 and 4 are exchanged according to the shape of the well 12.
The well portion 12 can be attached to the rim 11 having various shapes. In addition, since only a plurality of types of base portions 3 and 4 having a simple structure need to be prepared according to the shape of the well portion 12, the mounting cost does not increase significantly.

Further, the present invention is extremely effective when the air pressure sensor housed in the case 1 is constituted by a diaphragm. That is, the membrane surface of the diaphragm needs to be arranged in the normal direction of the tire rotation axis in order to avoid the influence of the centrifugal force, but by using the base portions 3 and 4 having an appropriate inclination angle, the membrane surface of the diaphragm is Since the surface can always be arranged in the normal direction of the tire rotation axis, accurate internal pressure detection can be performed.

In the present invention, since the case 1 is composed of the cover 2 and the bases 3 and 4, these can be composed of different materials. For example, while the cover 2 is made of a material that emphasizes strength,
The base portions 3 and 4 are preferably made of a heat-insulating material such as urethane resin, epoxy resin, and engineering plastic. When a material having heat insulating properties is used for the base portions 3 and 4 as described above, even if heat generated in a brake or the like is transmitted to the rim 11, the base portions 3 and 4 can be used.
The circuit and the battery in the case 1 can be protected from heat by the heat insulating effect of.

The bases 3 and 4 are preferably bonded to the well 12 via a flexible double-sided tape. By interposing the flexible double-sided tape between the base portions 3 and 4 and the well portion 12 as described above, the rotational movement of the case 1 with respect to the rim 11 can be prevented, and the well portion of the case 1 can be prevented. 12 can be stabilized.

Further, the strap 6 is preferably made of a heat-resistant resin such as nylon 6, nylon 66, or aramid. That is, the conventional metal band had to be made of a metal such as stainless steel having corrosion resistance to the atmosphere in the tire, so that the production cost was high. , The manufacturing cost can be reduced.

The strap 6 may be simply wound around the well portion 12, but when the well portion 12 has a taper angle with respect to the tire rotation axis direction, the strap 6 is rotated around the case 1 by tightening. There is a possibility that the position of the case 1 is shifted due to the moment being applied. If the position of the case 1 shifts, a measurement error occurs,
Alternatively, the case 1 may be damaged by contact with the tire when the tire is attached or detached.

For this purpose, at least one strap support 7, 8 is attached to the well portion 12 of the rim 11,
It is preferable that the position of the strap 6 in the rim width direction be held by the strap supports 7 and 8. By providing the strap supports 7 and 8, the position of the strap 6 can be stabilized even when the width of the well portion 12 is wide such as in a truck or a bus.

It is preferable that the strap supports 7 and 8 not only hold the strap 6 but also serve as a counterweight 9 for the case 1.
Since the strap supports 7 and 8 also serve as the counterweight 9 in this manner, the balance of the entire wheel can be maintained without any additional counterweight.

In the above embodiment, two types of base portions are prepared. In the present invention, two or more types of many base portions can be prepared according to the shape of the well portion. A large number of well shapes can be accommodated by the base portion. The sensor unit housed in the case 1 is mainly for detecting air pressure, but may be provided with a means for physically measuring the internal environment of the tire, such as a thermometer.

[0026]

As described above, according to the present invention, the case accommodating the wireless sensor unit including the air pressure sensor is attached to the well portion of the rim, and the case is annularly mounted on the well portion of the rim. In the internal pressure detecting device for a pneumatic tire that is held by a strap, the case includes at least a cover portion on which a pneumatic pressure sensor is mounted, and a base portion interposed between the cover portion and a well portion of a rim. By making the base part freely replaceable with one that matches the shape of the well part, it is possible to attach the internal pressure detection device to various rims regardless of the shape of the well part while suppressing an increase in installation cost. Will be possible.

[Brief description of the drawings]

FIG. 1 is a front view exemplifying a state in which an internal pressure detecting device for a pneumatic tire according to an embodiment of the present invention is installed in a well portion (inclined) of a rim.

FIG. 2 is a front view illustrating a state in which the internal pressure detecting device for a pneumatic tire according to the embodiment of the present invention is installed in a well portion (no inclination) of a rim.

FIG. 3 is a front view showing a use state of the internal pressure detecting device of FIG. 1;

FIG. 4 is a side view showing a use state of the internal pressure detecting device of FIG. 1;

5 (a) is a front view showing a cover part in FIGS. 1 and 2, FIG. 5 (b) is a side view thereof, and FIG. 5 (c) is a top view thereof.

FIG. 6A is a front view showing a base part in FIG. 1,
(B) is its side view, (c) is its top view.

FIG. 7A is a front view showing a base unit in FIG. 2;
(B) is its side view, (c) is its top view.

8A is a front view illustrating a strap support according to the present invention, FIG. 8B is a side view thereof, and FIG. 8C is a top view thereof.

9A is a front view illustrating another strap support according to the present invention, FIG. 9B is a side view thereof, and FIG. 9C is a top view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Cover part 3, 4 Base part 6 Strap 7, 8 Strap support 11 Rim 12 Well part

Claims (7)

[Claims] 1. A pneumatic tire in which a case accommodating a wireless sensor unit including an air pressure sensor is attached to a well portion of a rim, and the case is held by a strap mounted annularly on the well portion of the rim. In the internal pressure detecting device, the case comprises at least a cover part on which the air pressure sensor is mounted, and a base part interposed between the cover part and the well part of the rim, and the base part is formed of the well part. An internal pressure detector for pneumatic tires that can be replaced according to its shape. 2. The pneumatic tire internal pressure detecting device according to claim 1, wherein said air pressure sensor is constituted by a diaphragm, and a film surface of said diaphragm is arranged in a direction normal to a tire rotation axis. 3. The pneumatic tire internal pressure detecting device according to claim 1, wherein the base portion is made of a material having heat insulating properties. 4. The device according to claim 1, wherein said base portion is bonded to said well portion through a flexible double-sided tape.
The internal pressure detecting device for a pneumatic tire according to any one of claims 1 to 3. 5. The pneumatic tire internal pressure detecting device according to claim 1, wherein the strap is made of a heat-resistant resin. 6. The rim according to claim 1, wherein at least one strap support is attached to a well portion of the rim, and the position of the strap in the rim width direction is held by the strap support. Pressure sensor for pneumatic tires. 7. The pneumatic tire internal pressure detecting device according to claim 1, wherein the strap support also serves as a counterweight for the case.