JPS5876995A - Overheating alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a warning device for when the temperature of a rotating member of a running vehicle exceeds a set value. In practice, the function of the alarm system of this invention is to monitor the temperature of the tires or brake system.

It is well known that the tires of a moving car heat up due to the friction between the tires and the pavement.

Under normal conditions, that is, when the tire pressure is appropriate, heating is kept within an acceptable range.

However, if the air pressure in the tire is excessively low (for example, due to unnecessary handling of cheap pulp, or due to small holes or wear in the cheap tire) or due to heat absorption from outside (for example, in the brake system). Tires may overheat due to excessive heat (such as when exposed to sunlight for long periods of time) or when exposed to direct sunlight for a long period of time. As a result, the tread may peel off and the tire may explode, which is extremely dangerous.

Generally, 1 tL of vulcanization in the tire manufacturing process is 140 to 155C, but it is considered dangerous if the temperature during use exceeds about 125C.

Temperature monitoring is also required in the brake system. This is because if the brakes are used for a long time, they tend to overheat. Generally, the allowable temperature of brake friction material is maximum 250G, and if it is instantaneous, it is 500 to 5 seconds.
It is considered to be oc.

When overheating occurs in this way, the problem 2') occurs.

As the 1st K temperature rises, the braking force decreases, and eventually the vehicle is no longer able to decelerate or stop sufficiently, leading to the 9th problem. Second, the generated heat is transferred to the tire, causing the above-mentioned situation.

In any of the above cases, the temperature of the rotating member is monitored while the vehicle is running, and if overheating occurs, an optical or acoustic warning is transmitted to a location that is easily visible to the driver, alerting the driver to the danger.

An object of the present invention is to provide a device for generating the above-mentioned alarm.

The device has one or more temperature sensors or temperature detectors connected to a transmitter. The transmitter rotates with the rotating member being monitored and activates the alarm.

This temperature sensor is a passive component. For example, bimetallic or magnets are used which are demagnetized when the temperature exceeds 90°.

The status of the temperature sensor is communicated by a device using electromagnetic waves, such as a small radio transmitter. Since this transmission range is sufficient to be on the order of several tens of meters, the power supply for the transistor is extremely small.

In general, neither the method of transmission nor the frequency (frequency bands distributed by international organizations need to be taken into account) are important.

When implemented, special operating conditions must be taken into account. That is, the problems that plague wireless transmitters must be solved by a number of circuit changes, technical and mechanical methods.

In terms of circuit design, it is desired to design a circuit that is small, durable, extremely simple, highly reliable, and inexpensive. In this way, electromagnetic waves of a single frequency can be easily generated, and information can be obtained based on the presence or absence of that frequency.

Generating electromagnetic waves of a specific frequency to notify abnormal situations is beneficial because it also saves power consumption. This is because when a detector detects an abnormality, (Only in this case) (because the tuteri needs to operate).

This electromagnetic wave can be generated by an oscillator or the like, which is used to generate a carrier wave in conventional wireless transmitters.

Simplifying the circuitry provides frequency stability, simplifies the radio receiver, and eliminates the risk that the transmitted electromagnetic waves will not be received if the transmitter and receiver are not tuned.

By taking measures such as those described above, the frequency can be stabilized without having to be reabsorbed by a fragile and expensive crystal oscillator.

Frequency can be stabilized by fabricating circuits such as thick film hybrid circuits.

This circuit has high mechanical strength and excellent heat dispersion within the circuit, and can also adjust the functions of circuit components and reliably perform frequency tuning.

Furthermore, looking at the circuit, it is better to sweep the frequency close to the tuning frequency. This has two purposes:
One is to tune the receiver to a certain frequency within the sweep range to eliminate reception errors of electromagnetic waves.The other is to tune the receiver to a certain frequency within the sweep range to eliminate reception errors of electromagnetic waves. Even if the driver is noisy, it is sufficient to easily configure it with a pump generator, ie, a sawtooth voltage generator.

Considering the situation, the installation must be something that does not require a conventional antenna.

Mechanically, it is necessary to have high reliability, which can be achieved by using a thick film hybrid circuit as the circuit and embedding the transmission circuit and power battery in resin.

The device is double wrapped in two types of resin. That is,
The inside is wrapped with silicone resin for shock absorption, and the outside is wrapped with fluorocarbon resin, which has high air shielding and shock absorption properties.

By manufacturing the transmitter and power battery as one unit,
Electrical contact is ensured. This is because the contact part does not come into contact with the atmosphere, cannot be used as a contact part, and there is no mistake in attaching the contact part in advance.

In another embodiment, the transmitter utilizes mutual induction between the negative and secondary windings. In this case - the primary winding is fixed to the vehicle body and one secondary winding is fixed to the rotating member, this secondary winding being in a position where it can oppose the primary winding for a short time with each revolution of the rotating member. is set to

Other features of the invention will become clear from the description based on the following drawings.

Next, one embodiment of the present invention will be described with reference to the drawings. 1st
The figure shows a tire 1 and a brake drum 2 of a car wheel.
In this figure, one temperature detector 3 is attached to the brake drum 2, and one or more temperature detectors 4 are attached to the tire l.

FIG. 2 is a block diagram of the device of the present invention, in which the temperature detector Ra is electrically connected to a transmitter T1, and the output side of this transmitter Ti is connected to a light or acoustic alarm G.
is wirelessly connected to a receiver R1 having a receiver R1.

FIG. 3 is a diagram of an oscillation circuit, in which NPN) transistor 5
The collector of is connected to the LC circuit 6.7 and further connected to the power supply 8.
connected to. Transistor 50 is connected to a voltage divider 9.10 arranged between power supply 8 and ground 11. A capacitor 12 serving as a filter is connected in parallel with the resistor 10.

The emitter of transistor 5 is connected to ground 11 via a resistor 13 and a capacitor 14 in parallel with resistor 13, and to a coil 15 which serves as an antenna.

Capacitor 16 is connected to capacitor 7 and capacitor 114.

The operation of the circuit shown in FIG. 3 is as follows. If the circuit is closed between power supply 8 and ground 110, capacitor 7 will be charged by power supply 8 until inhibition by transistor 5 occurs, after which capacitor 7 will discharge. Repeat this cycle again.

The oscillation frequency is determined by the inductance of the coil 6 and the capacitance of the capacitor 7.

A temperature detector is arranged in parallel with the switches 17, 18 (and possibly others). If the temperature is below the detected limit value, it acts as an open switch, and if it exceeds the limit value, it acts as a close switch. Therefore, the oscillator will not operate if the temperature is below the limit value, and will operate when the temperature exceeds the limit value and the circuit is closed.

If a plurality of switches, shown here as switches 17 and 18, are arranged in parallel, the oscillator will start operating as soon as one of them closes.

A diode 28 and a holding resistor 29 are arranged in parallel in the power supply circuit. This diode 28 emits light due to the operation of the oscillator.

In this circuit, only one frequency is oscillated, but this frequency can be changed by changing the amount of capacitor 70.

For the reasons stated above, it is desirable that the oscillation frequency be set within a narrow range and periodically varied between nine maximum and minimum frequencies. This is possible using the circuit shown in FIG. In this circuit, by modifying the bias at the base of transistor 5, the switching time of the transistor is changed, and thereby the oscillation frequency is also changed.

Referring to FIG. 4, the collector of PNP transistor 19 is connected to voltage <II8 through a resistor 20 and to ground 11 through a capacitor 21. Further, the cap of the transistor 19 is connected to the base of the NPN transistor 22 and is also connected to the ground 11 via the capacitor 23.

PNP) run raster 190 pace is transistor 2
The transistor 5 is connected to the collector of the transistor 2 and to the power supply via a resistor 24, and to the base of the transistor 5 via a capacitor 25 and a coil 26 arranged in series. Resistor @27 grounds the collector of transistor 22.

The operation is performed as follows. Transistor 19 operates as an oscillator, while transistor 22 operates as a switch that shorts out the voltage generated by the oscillator when it drops.

In reality, the operation of this circuit is performed by an integrated circuit having the same function. This integrated circuit is commercially available from several companies under the product name NE555.

As a receiver, a commercially available conventional frequency modulation receiver may be used. A rectifier is connected to the high frequency output terminal of this receiver so that a warning light can be turned on or an alarm can be activated.

Monitoring a large number of points creates the problem of sensing a malfunctioning wheel (or malfunctioning brake system) since the transmitters all operate at the same frequency. When the oscillator is activated, the switches 17, 18 are closed and the light emitting diode (LED) 28, held by the resistor wI 29, is activated. Accordingly, the driver notices the alarm and stops the vehicle to see which of the device's respective D-odes 28 are illuminated.

In another embodiment of FIGS. 5 and 6, the device includes a detector Ra(S) formed by the secondary winding of the transformer.
), and this detector Ra(S) has a number of alarms G1.
G2. G3... which operates Gn - is connected to the next winding Ti■. Details of this device are shown in Figure Ii6.

This device consists of three components. The first component is the secondary winding 30 of the transformer, to which is connected one or more switches 17,18.

This secondary winding is attached to the rotating member and used for monitoring during rotation. In each rotation, this secondary winding passes in front of the primary winding 31. This -order winding 31 is the second component, one end of which is &e.

It is connected to a generator 32, and the other end is connected to a resistor 33. a, e, the circuit of the generator 32 has an optocoupler 34, the emitter side of the power receiving end is connected to the pace of the NPN transistor 35, the collector side is connected to the collector of the transistor 35, and this collector is connected to the resistor 37. The power supply 36 is connected to the power supply 36 via the power supply 36. The emitter of transistor 35 is connected to the pace of transistor 38 and is connected to resistor 9.
39 to the transistor 35's own pace. The conductor of the (NPN) transistor 38 is connected to ground 40 via a resistor 41, connected to the power source 36 via the resistor 41, and serves as a direct output terminal 43.

The operation of this device is as follows. Switch 17.
When 18 is closed, a current change occurs in the negative circuit. This current change is controlled by the optocoupler 34 and the transistor 3
5 to the transistor circuit (current loop). As long as the switches 17.18 are in the open state, no signal will appear at the output terminal;
Closing 18 generates a signal, the frequency of which is proportional to the rotational speed of the rotating member, which activates the alarm.

Needless to say, the operation of this temperature sensing switch is performed by a small magnet.

That is, the circuit is kept open by the magnet attracting the piece of iron, but when the temperature of the magnet exceeds the key temperature, the magnet loses its ability to attract the piece of iron.

Although the invention has been described with reference to two preferred embodiments, it will be appreciated that many variations and modifications may be made within the scope of the invention.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view in the axial direction of a wheel in a state in which the device of the present invention is rolled over 4E, Fig. 2 is a block diagram of the device of the present invention, Fig. 3 is a circuit diagram of the oscillator, and Fig. 4 5 is a block diagram of another embodiment of the present invention operating by mutual induction, and FIG. 6 is a circuit diagram of the other embodiment. 1... Tire 2... Brake drum 3.
4...Temperature detector 5.22.35.38...NPN) Ranjistaro, 1
5...Coil 8.36...Power supply 17.1
8...Switch 19...PNP) Transistor 28...Diode 30...Secondary winding 3
1...-Next winding 32...a, c, generator 3
4...Optocoupler 43...Output end drying
Patent Attorney Oka 1) Hidehikoig 1

Claims (1)

[Claims] (l) An overheat warning device for a rotating member of a running vehicle, comprising one or more temperature detectors and a transmitter, the temperature detector being connected to the transmitter, and the temperature detector being connected to the transmitter. An alarm device characterized in that a transmitter rotates together with the rotating member to be monitored, and activates a light or acoustic alarm when the vehicle is approached. (2) The IIFll device according to claim 1, wherein the transformer (the ivy is a radio oscillator attached to the rotating member) and the alarm are operated by a radio receiver. (3) The transmitter has a fixed primary winding and is a secondary winding of a traveling pressure device, and the secondary winding and the secondary winding take opposite positions for a short time each time the rotating member rotates. An alarm device according to claim 1. (4) The radio oscillator acts as an efficient oscillator by using a thick film hybrid circuit, the thick film hybrid circuit being formed on a ceramic support, some of which are solid components and other parts. The device is characterized in that the part is an integrated circuit component. (5) Claims 1.2 to 9 are characterized in that the wireless transmitter has a small power supply battery, and the battery is wrapped in silicone resin and further wrapped in fluorocarbon resin. The alarm device described in item 5 or 1 of item 4. (6) Claim 111.2., wherein the wireless transmitter generates only a single wavelength carrier wave.
The alarm device according to any one of Items 4 and 5. (7) The alarm device according to claim 6, wherein the wireless transmitter does not include a conventional antenna, and a coil of an oscillation circuit serves as an antenna. (8) The radio transmitter may include a transistor as an oscillator, and by applying a sawtooth voltage to the transistor, the bias thereof may be varied and the oscillation frequency may be periodically varied within a narrow range. 8. The alarm device according to claim 7, wherein the alarm device is enabled. (9) Since the power source for the primary winding of the transformer is a 5.6° generator, the C0 generator circuit has an opto-coupler, and this opto-coupler connects the secondary winding to the 4. The alarm device according to claim 3, wherein a change in current that occurs when passing in front of the winding is transmitted to the output side of the circuit. (to) The alarm device according to claim 1, wherein the temperature detector is a bimetal that acts as a switch within the alarm generation circuit. Claim 1 characterized in that when the key temperature exceeds one temperature, the state always changes and acts as a switch.
Alarm device as described in section. (to) Claims 1 to 11, characterized in that the alarm generation circuit has one or more light emitting diodes, and lights up to issue an alarm signal when the temperature exceeds a set value. The alarm device according to any one of the above.