JP2000062419A - Tire air pressure detection transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a transmitter not transmit pressure data in the case of a tire air pressure detector unit by stopping the subsequent transmission control when the condition where the measured pressure is within a range of the set pressure continues for a fixed period. SOLUTION: When a transmission request is generated (S2) from a microcomputer, it is determined whether the measured pressure is within a range of set pressure or not (S4), and when the measured pressure is within a range of set pressure, further it is confirmed whether transmission is being stopped or not (S5). When transmission is being stopped, transmission is not executed to wait for the next transmission request, so a periodic transmission timer is cleared (S10). When transmission is not being stopped in the state S5, an air pressure measurement counter is incremented (S6). The count data is judged (S7), and in the case of overflow, transmission stop setting is performed so as to transfer to the mode of stopping the transmission control (S11), and hereinafter, the transmission control is not executed.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire pressure detection transmitter, and more particularly to a tire pressure detection transmitter capable of extending battery life. . 2. Description of the Related Art Conventionally, there has been a tire pressure detection transmitter with a built-in battery. As shown in FIG. 2, the tire pressure detection transmitter 1 is designed so that the microcomputer 2 starts operating when combined with the battery 7. In the case of such an apparatus, the microcomputer 2, the battery 7 and the circuit board are usually combined together and molded so as to be housed in one case. It was not possible to restart the microcomputer 2 by controlling the terminals and the like, so that when the battery 7 was combined, the system of the microcomputer 2 had to be started. The microcomputer 2 molded together with the battery measures the data detected by the pressure sensor from that time, and is controlled to periodically transmit the pressure measurement data from the transmission circuit 5 to the antenna 6. . [0003] However, the tire pressure detection transmitter constructed as described above has a tire pressure detection and transmission time period from the completion of manufacture and assembly until the tire is actually mounted on a tire. Although it was only stored in a warehouse by itself, it not only measured the pressure but also periodically transmitted the measurement data. Therefore, since pressure data is transmitted periodically during the storage period, there is a problem that even in the storage period, the same battery consumption occurs as when the tire is mounted. For this reason, the storage period is also included in the continuous use period of the tire pressure detection transmitter, and if the storage period is long, only the period,
The continuous use period after mounting on the actual tire is shortened, that is, the life of the tire pressure detection transmitter is shortened, which may be a factor that may cause user dissatisfaction.
Therefore, the present invention, when the tire pressure detector body,
The purpose is to provide a tire pressure detector that does not transmit pressure data. [0004] In order to achieve the above-mentioned object, an invention according to claim 1 of the present invention uses a battery as a power supply and measures a pressure sensor for measuring pressure, and a pressure sensor for measuring pressure. A microcomputer that issues pressure measurement instructions at regular intervals, a transmission circuit that converts pressure data sent from the microcomputer at regular intervals into a transmission waveform, and a transmission antenna that transmits the transmission waveform converted by the transmission circuit to the outside It is constructed and attached to the inside of the tire to transmit the pressure data inside the tire while the car is running. The tire pressure detection transmitter counts every time the state where the measured pressure is the set pressure is measured. If the measured pressure is not the set pressure, and if the measured pressure is not the set pressure, a barometric pressure measurement counter is controlled to reset the data counted so far. As an element, the air pressure measurement counters, when it reaches the counting count is set in advance, and inputs the inverted signal of the transmission request signal outputted from the microcomputer pressure measurement counter overflow signal AN
When the state where the measured pressure is the set pressure continues for a certain period of time by using the D circuit as a component, the transmission control thereafter is stopped to extend the life of the battery,
It is a means of problem solving. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration diagram of a tire pressure detection transmitter of the present invention. FIG. 2 shows a configuration diagram of a conventional tire pressure detection transmitter. FIG. 3 is a count control flowchart according to the present invention. In FIG. 1, a tire pressure detection transmitter 1 is shown.
Measures the pressure with the pressure sensor 3 and transmits data from the antenna 6 via the transmission circuit 5 at regular intervals. The microcomputer 2 in the tire pressure detection transmitter 1 obtains pressure data from the pressure sensor 3 at regular intervals (for example, every 15 seconds). The data is calculated inside the microcomputer 2. If the difference between the previous measured pressure data and the current measured pressure data value is equal to or less than a preset pressure fluctuation value, the microcomputer 2 calculates the data until the next measurement period. It is designed to be in a low power consumption mode (usually called a sleep mode) by itself and to minimize the consumption of the battery 4. When the pressure measurement performed at regular intervals is performed a fixed number of times, the pressure data measured at that time is output to the transmission circuit 5 and the data is transmitted to a receiver (not shown) via the transmission antenna 6. . This is usually called periodic transmission. [0008] By the way, a tire pressure detection transmitter is originally mounted on a tire, and its usefulness is generated only when the vehicle is in a running state. Usually, it is not necessary to keep the tire pressure detection transmitter attached to the tire at the time of storage, and it is considered that the tire pressure detection transmitter alone is usually stored in a storage warehouse, shelf, or the like. Therefore, during normal storage, the measured pressure is always at a constant atmospheric pressure. FIG. 1 shows an outline of a tire pressure detection transmitter according to the present invention. As an example, set pressure is 1 atm ± 0.2
Pressure. According to this figure, the measurement data of the pressure sensor 3 that performs the pressure measurement in response to the instruction from the microcomputer 2 is:
When the pressure is close to 1 atm, the microcomputer 2 outputs a count signal 7 to the 1 atm detection counter 8 added to the components in the present invention every time the pressure is measured, and the pressure measurement counter 8 sets a preset count value. Is reached, the count-over inversion signal 9 output from the atmospheric pressure measurement counter 8 becomes “L”, and even if the microcomputer 2 outputs the transmission request signal 10 as “H”, the output of the AND circuit 11 Becomes "L" (OFF state), as a result, the information of the transmission request signal 10 is not transmitted to the transmission circuit 5, and the transmission control is not performed. In this case, the tire pressure detection transmitter is in a storage state, and is in a so-called periodic transmission stop mode in which periodic transmission thereafter is temporarily stopped. Next, when the measured pressure data is not a value within the set pressure range, the reset signal 12 is output from the microcomputer 2 each time, so that the atmospheric pressure measurement counter 8 is reset and counted up to that time. The value is reset to zero. Therefore, the count-over inversion signal 9 output from the atmospheric pressure measurement counter 8 changes from “L” to “H”. In this case, when the microcomputer 2 outputs the transmission request signal 10 at “H”, the AND circuit 1
1 becomes "H" (ON state) and the transmission request signal 1
The information of 0 is transmitted to the transmission circuit 5 as it is, and the transmission control is performed. Next, the control of the present invention will be described with reference to FIG. When a transmission request is generated from the microcomputer 2 (S2),
It is determined whether the measured pressure is within the set pressure range (S
4) If it is out of the range, the atmospheric pressure measurement counter is cleared (S
3) Transmission control is performed as requested by the microcomputer 2 (S8). Then, the transmission stop flag is cleared so that the transmission control is performed thereafter (S9). If state S4
If the measured pressure is within the set range, it is further confirmed whether transmission is stopped (S5). Then, if the transmission is stopped, the transmission is not performed, and the periodic transmission timer is cleared to wait for the next transmission request (S10). If the transmission is not stopped in state S5, the atmospheric pressure measurement counter is incremented (S6). Then, it is determined whether or not the count data overflows (S7). And if it overflows,
In order to shift to the mode in which the transmission control is stopped, the transmission stop setting is performed (S11), and thereafter, the transmission control is not performed even if a transmission request from the microcomputer 2 occurs. By performing such control, the transmission stop mode can be set by measuring the set pressure a certain number of times, and unnecessary transmission control is not performed. Also,
By measuring the pressure outside the set range, the mode immediately shifts to the mode in which the normal transmission control is performed, and the state having the function as the tire pressure detection transmitter is obtained. This state may be considered assuming that the tire pressure detection transmitter of the present invention is mounted on a tire. Because the pressure inside the tire is about three times higher than the atmospheric pressure, when the tire pressure detection transmitter 1 is mounted inside the tire, pressure data other than the set pressure of 1 atmosphere is measured at the time of measurement. That is because it can be expected. As described above, transmission control is not performed during the storage period, and the battery life can be greatly extended. Taking this measurement result as an example, 10
When a 00 mAh battery is used, the current consumed for one transmission is 1 mA second, and the current consumed for performing one pressure measurement is 0.007 mA second, where the battery effective utilization rate is 50%. If the regular transmission is 10 minutes and the interval between the detectors is 15 seconds, it will last about 15 years. However, in the case of the conventional tire pressure detection transmitter, normal transmission is performed even during storage. In addition, the storage period in the warehouse etc. after manufacturing is 1
Considering the year, the actual usage period is 14 years. According to the present invention, since only pressure detection is performed during the storage period, the current consumption is reduced.
Since the total current consumption per year is only about 4 mAh, the period of regular transmission after mounting the tire is about 14.9 years, and the use period can be extended by nearly one year compared to the conventional method. This is because, in the storage state, only measurement control with very low current consumption is performed, and transmission control with high current consumption is performed after the tire is mounted on the tire. As described above, according to the present invention, while the tire pressure detection transmitter is stored, useless transmission is stopped, so that the conventional tire pressure detection can be performed. Compared with the transmitter, the battery consumption during storage can be greatly reduced, and its practicality is very large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a tire pressure detection transmitter according to the present invention. FIG. 2 is a schematic diagram of a conventional tire pressure detection transmitter. FIG. 3 is a count control flowchart according to the present invention. [Description of Signs] 1 Tire pressure detection transmitter 2 Microcomputer 3 Pressure sensor 4 Battery 5 Transmission circuit 6 Antenna 7 Barometric pressure measurement counter 8 Count over inversion signal 9 Transmission request signal 10 AND circuit 11 Reset signal

Claims (1)

Claims: 1. A pressure sensor that measures pressure using a battery as a power supply, a microcomputer that issues a pressure measurement instruction to the pressure sensor at regular intervals, and a pressure that is sent from the microcomputer at regular intervals. It is composed of a transmission circuit that converts data into a transmission waveform and a transmission antenna that transmits the transmission waveform converted by the transmission circuit to the outside. In the tire pressure detection transmitter that transmits the data, the count is incremented every time the measured pressure is at the set pressure, and if the measured pressure is not the set pressure, the data that has been counted up to that point is reset A pressure measurement counter controlled to be controlled is a constituent element, and the pressure measurement counter is a preset measurement count number. When the measured pressure reaches the set pressure, an AND circuit that receives the transmission request signal output from the microcomputer and the inverted signal of the overflow signal of the atmospheric pressure measurement counter as inputs is used as a component. A tire pressure detection transmitter characterized by not performing transmission control after that for a certain period of time to extend the life of the battery.