JP2003146033A - Tire internal pressure alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire internal pressure alarm device capable of suppressing adhesion of oil droplets included in a tire inner hollow part to a pressure sensor pressure sensitive part and enhancing reliability of a pressure detecting function. SOLUTION: A sheet sealing an opening to a casing outer side face of a through-hole guiding an internal pressure to the pressure sensitive part of a pressure sensor is applied to the casing outer side face, and a detour passage opened to a wall face of the through-hole and the tire inner hollow part is provided on the casing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a tire internal pressure alarm device for monitoring a tire pressure condition in a vehicle and notifying a driver of an abnormality.

[0002]

2. Description of the Related Art Conventionally, a tire mounted on a rim of a vehicle is used to detect the air pressure of a tire, and information regarding this air pressure is transmitted to a receiver provided on the vehicle side by radio waves to notify a driver of an abnormal air pressure. A tire internal pressure warning device for informing is known, and such an internal pressure warning device is shown in FIGS. 3 to 4.

FIG. 3 is a schematic cross-sectional view showing a mounted state of the tire internal pressure warning device 91. The tire internal pressure alarm device 91 is formed integrally with a cylindrical valve device 95 for injecting internal pressure into the tire 97, and is attached to the well portion side surface 94 of the rim 92. The tire internal pressure alarm device 91 is arranged in the well portion of the rim as close as possible to the outer peripheral surface of the well portion bottom surface 93 so as not to interfere with the tire 97 when the tire 97 is assembled to the rim 92.

FIG. 4 is a schematic sectional view showing the arrangement of parts in the conventional tire internal pressure alarm device 91. The tire internal pressure alarm device 91 includes an electronic board 81, a flat battery 82 for supplying electric power to the electronic board 81, and an antenna 84 for transmitting a processed signal to a receiver on the vehicle body side. A pressure sensor 83 for detecting the internal pressure of the tire and a semiconductor element are mounted on the electronic board 81, and the semiconductor element and the electronic board 8 are mounted.
The circuit pattern provided in 1 constitutes a signal processing circuit for processing the detected pressure signal.

Since the antenna 84 is connected to the signal circuit of the electronic board 81, it is patterned and stretched around the peripheral portion of the electronic board 81, or in the vicinity of the upper surface or the lower surface of the electronic board 81. It is stretched and arranged.

Further, the tire internal pressure alarm device 91 includes a lid portion 87 arranged substantially parallel to the electronic board 81 and a lid portion 8.
Casing 8 having an edge portion 88 projecting in a direction surrounding the electronic substrate 81 and the flat battery 82 from the peripheral edge of the casing 7.
It has 5. This casing 85 is used for the valve device 9
It is fixed to the well portion side portion 94 of the rim 92 integrally with 5, and protects the electronic substrate 81 and the flat battery 82 and supports them. Furthermore, after disposing the electronic substrate 81 and the flat battery 82 in the casing 85,
A sealing resin 86 that is injected and solidified is provided to fix these components and prevent corrosion of these components.

The tire internal pressure alarm device 91 is provided with the rim 9
It is necessary to suppress the height of the electronic substrate 81 and the flat battery 82 in the mounting posture so that the electronic substrate 81 and the flat plate-shaped battery 82 are accommodated in the well portion 2 of the rim 92.
Are arranged almost parallel to each other and are composed of two layers.

In the electronic board 81 and the flat battery 82, the flat battery 82 has a larger mass, and when the rim is rotated,
In order to surely support the flat battery 82 on which a larger centrifugal force acts, the conventional tire internal pressure alarm device 91 shown in FIG.
As shown in FIG. 5, the flat battery 82 is placed in contact with the lid portion 87 of the casing 85. As a result, the tire internal pressure alarm device 91, in the mounting posture, has the coin battery 82.
Is arranged on the side of the rim 92 that is separated from the well portion bottom surface 93, as compared with the electronic substrate 81.

[0009]

The conventional tire internal pressure alarm device 91 as described above has the following problems, and a fundamental solution has been demanded.

Since the tire internal pressure alarm device 91 is used by being attached to the rim, it is designed to be as lightweight and compact as possible. Since the pressure sensor 83 used for this also needs to be small, an element that utilizes the change in its electrical characteristics due to pressure is generally used, and the pressure sensitive portion of this element is also extremely small. Is normal.

On the other hand, in the tire inner space surrounded by the tire and the rim, for example, an oil component such as grease may be applied to the rim and the tire may be inserted so as to facilitate the work when mounting the tire. Yes, as a result, in the tire inner space,
Small oil droplets float, which happens to be the pressure sensor 83.
When it adheres to the pressure-sensitive part, the pressure-sensitive part is narrow, and the entire pressure-sensitive part is blocked by oil droplets, which may cause a situation in which accurate pressure cannot be detected. Although this frequency is low, when there is an abnormality in the function for detecting pressure, there is no means for checking whether or not the abnormality has occurred, so there is a need to improve the reliability of this pressure detection function.

The present invention has been made in view of the above problems, and prevents the oil content from adhering to the pressure-sensitive portion of the pressure sensor, and thus has a highly reliable pressure detecting function for the tire internal pressure. The purpose is to provide.

[0013]

The present invention has been made in order to achieve the above object, and its gist structure and operation will be described below.

The tire internal pressure alarm device according to claim 1 is
A tire internal pressure alarm that includes a pressure sensor that detects the pressure in the inner space of the tire mounted on the rim and a casing that houses an electronic board, and a through hole that guides pressure to the pressure-sensitive portion of the pressure sensor is provided in the casing. In the device, a sheet for closing the opening of the through hole to the outer surface of the casing is attached to the outer surface of the casing, and a bypass passage opening to the wall surface of the through hole and the inner space of the tire is provided in the casing. Is.

This tire internal pressure alarm device according to the present invention is
A sheet for closing the opening of the through hole to the outer surface of the casing is attached to the outer surface of the casing, and a bypass passage opening to the wall surface of the through hole and the inner space of the tire is provided in the casing. Oil droplets on the part do not directly enter the through hole. In addition, since the bypass passage opening to the wall surface of the through hole and the tire inner space is provided in the casing, the inner pressure of the tire inner space can be guided to the pressure sensitive portion of the pressure sensor, and moreover, the tire inner space. From the pressure sensor to the pressure-sensitive part of the pressure sensor passes through the bypass passage, through the through hole, and then to the pressure-sensitive part of the pressure sensor. However, the probability of reaching the pressure sensitive portion of the pressure sensor can be suppressed, and the frequency of oil droplets adhering to the pressure sensitive portion can be greatly reduced.

The tire internal pressure alarm device according to claim 2 is
The sheet according to claim 1, wherein the sheet is a sticker.

According to this tire internal pressure alarm device, since the sheet is made into a sticker in which a serial number or a precautionary note for use in addition to this is described, these items of information necessary for quality assurance are described. The sticker can also have the function of the sheet, and it is not necessary to separately provide a sheet for closing the opening of the through hole, and the cost can be reduced.

The tire internal pressure alarm device according to claim 3 is
In any one of Claims 1-2, at least two or more said bypass passages are provided.

In this tire internal pressure alarm device, since at least two bypass passages are provided, even if one of the bypass passages is closed and the internal pressure cannot be introduced from this passage, the remaining bypass passages will not be introduced. The pressure can be introduced from the passage, and the reliability of the pressure detection function can be ensured.

The tire internal pressure alarm device according to claim 4 is
In any one of Claims 1-3, the inlet / outlet to the tire inner space of the valve device for filling a tire with internal pressure fluid was attached in a casing, and was provided in the casing outer surface from this inlet / outlet. An internal pressure filling passage communicating with the opening is provided, and at least one of the bypass passages is opened to the wall surface of the internal pressure filling passage.

In this tire internal pressure alarm device, at least one of the bypass passages is opened on the wall surface of the internal pressure filling passage that extends from the inlet / outlet of the valve device to the tire inner space to the opening provided on the outer surface of the casing. When the tire is filled with the internal pressure from the valve device, the oil droplets staying in the bypass passage can be blown into the inner space of the tire to remove the oil droplet from the bypass passage.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a tire internal pressure warning device according to the present invention will be described below with reference to FIGS. The tire internal pressure warning device described below is also used by being attached to the rim in the state shown in FIG. 3, like the conventional tire internal pressure warning device 91.

FIG. 1 is a partial cross-sectional view showing a tire internal pressure alarm device 10 of the first embodiment, taken in a cross section passing through the axis of a rim in its mounting posture. The tire internal pressure alarm device 10 includes an electronic board 11 and an electronic board 11
It has a flat battery 12 for supplying electric power to the antenna and an antenna 14 for transmitting a processed signal to a receiver on the vehicle body side. A pressure sensor 13 for detecting the internal pressure of the tire and another semiconductor element are mounted on the electronic board 11, and the other semiconductor element and the circuit pattern provided on the electronic board 11
A signal processing circuit that processes the detected pressure signal is configured.

Further, the tire internal pressure alarm device 10 has a through hole 35 for guiding the internal pressure to the pressure sensor 13 and is arranged adjacent to the electronic board 11 and substantially parallel to the lid 32.
The casing 31 is configured to include an edge portion 33 protruding from the peripheral edge of the lid portion 32 in a direction surrounding the electronic substrate 11 and the flat plate-shaped battery 12. The casing 31 is integrated with the valve device 21 and is fixed to the well portion side portion 22 of the rim, and the electronic substrate 11 and the flat battery 12 are fixed.
It protects and supports them. further,
In the casing 31, the electronic board 11 and the flat battery 12 are provided.
After arranging and, the sealing resin 36 is injected and fixed, which fixes these parts and prevents corrosion of these parts.

Since the tire internal pressure alarm device 10 is provided so as to be housed in the well portion of the rim, it is necessary to suppress the height thereof. In the mounting posture, the electronic substrate 11 and the flat battery 12 are both placed. It is arranged substantially parallel to the bottom surface 23 of the well portion of the rim and has two layers.

In the tire internal pressure alarm device 10, the electronic substrate 11 and the well portion bottom surface 23 in the mounting posture.
Since the flat plate-shaped battery 12 is disposed between and, the pressure sensor 13 mounted on the electronic substrate 11 can be disposed close to the through hole 35 provided in the lid portion of the casing 31, The degree of freedom in designing the mounting position of the pressure sensor can be increased, and as a result, the cost of the device can be reduced.

FIG. 2A shows a tire internal pressure alarm device 10.
Is a plan view seen from the outer surface side of the lid portion 32 of the casing,
FIG. 2B is a side view thereof. A sticker 41 is attached to the outer surface of the casing 31 to close the opening of the through hole 35 that guides pressure to the pressure sensitive portion of the pressure sensor 13 to the inner space of the tire, and the detour passage opens to the wall surface of the through hole. 42 are provided crossing each other vertically and horizontally. The bypass passage 42 provided in the longitudinal direction extends on the outer surface of the casing to a portion to which the sticker is not attached, and opens there to the inner space of the tire.

Inlet / outlet port 26 to the inner space of the tire of the valve device
Is opened in the casing 31, and an internal pressure filling passage 27 connecting the inlet / outlet 26 and the tire inner space is formed in the casing 31.
It is provided inside. On the wall surface of the internal pressure filling passage 27,
When a part of the bypass passage 42 is opened and the internal pressure is filled from the valve device 21, the oil enemy remaining in the bypass passage 42 can be blown and removed from the bypass passage 42.

The sticker 41 has a manufacturer's name 43, a serial number 44, and a handling precaution 4
Item 5 required for quality assurance is described, and this sticker 41 can be made to function as a sheet for quality assurance and at the same time as a sheet for closing the opening of the through hole 35. .

[0030]

As is apparent from the above description,
According to the present invention, a sheet for closing the opening to the casing outer surface of the through hole that guides the internal pressure to the pressure sensitive portion of the pressure sensor is attached to the casing outer surface, and the wall surface of the through hole and the tire inner space are provided. Since the bypass passage opening to the casing is provided in the casing, it is possible to suppress the adhesion of oil drops contained in the tire inner space to the pressure-sensitive portion of the pressure sensor, and improve the reliability of the pressure detection function.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a tire internal pressure warning device according to the present invention.

FIG. 2 is a plan view and a side view showing a tire internal pressure alarm device.

FIG. 3 is a schematic cross-sectional view showing a mounted state of a tire internal pressure alarm device.

FIG. 4 is a sectional view showing a conventional tire internal pressure alarm device.

[Explanation of symbols]

10 Tire pressure warning device 11 Electronic board 12 Flat battery 13 Pressure sensor 14 antenna 21 Valve device 22 Side of well of rim 23 Bottom of well of rim 26 Inlet / outlet of valve device 27 Internal pressure filling passage 31 casing 32 Casing lid 33 Edge of casing 35 through hole 41 stickers 42 Detour passage 43 Manufacturer's name 44 cerial number 45 Notes on handling

Claims (4)

[Claims] 1. A pressure sensor for detecting a pressure in an inner space of a tire mounted on a rim, and a casing for accommodating an electronic board, the casing having a through hole for introducing pressure to a pressure-sensitive portion of the pressure sensor. In the tire internal pressure alarm device provided, a sheet for closing the opening of the through hole to the outer surface of the casing is attached to the outer surface of the casing, and the bypass passage opening to the wall surface of the through hole and the inner space of the tire is provided in the casing. Tire pressure warning device installed in the. 2. The sheet is a sticker.
The tire internal pressure alarm device described in. 3. The tire internal pressure warning device according to claim 1, wherein at least two or more bypass passages are provided. 4. An inlet / outlet to a tire inner space of a valve device for filling a tire with an internal pressure fluid is mounted in a casing, and an internal pressure filling passage is provided from this inlet / outlet to an opening provided on the outer surface of the casing. The tire internal pressure alarm device according to any one of claims 1 to 3, wherein at least one of the bypass passages is opened on a wall surface of the internal pressure filling passage.