JPS6381240A - Monitor device for physical parameter and usage thereof - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application and Problems to be Solved by the Invention The present invention relates to a device for monitoring physical parameters.In particular, the present invention relates to a device for monitoring physical parameters. The present invention also relates to a method of using an apparatus for monitoring physical parameters.The present invention also relates to a method of using an apparatus for monitoring physical parameters. The parameters are pressure or force, temperature, and humidity.In this regard, in particular, the present invention relates to a particular transducer for monitoring tire pressure, and to a method of monitoring tire pressure. The present invention
The present invention relates to tires and wheels equipped with the transducer, and also relates to a vehicle equipped with these tires and wheels.

SUMMARY OF THE INVENTION An electrically operable passive monitoring means provided in one form of the invention has a resistivity and a characteristic capacitance and inductance. Since the selected one of the characteristic capacitance and inductance is variable, the natural frequency changes in response to changes in the monitored parameter.

Said passive monitoring means is used with a transducer for monitoring physical parameters.

The monitoring means has a characteristic inductance and a capacitance, but no separate capacitance or inductance.

In one embodiment, the monitoring means comprises a long conductive wire wound in the form of a coil, with spacing between adjacent turns of the coil.

If the parameter being monitored is pressure or force, each turn of the coil is elastically arranged with respect to each other. An elastic flexible membrane is disposed between each turn of the coil and each turn of the coil is secured to the membrane. In use, as the membrane deflects under the action of a monitored pressure or force, the spacing between each turn changes, the characteristic inductance or capacitance of the coil changes, and the natural frequency of the coil changes. . In this configuration, the coils can also be arranged side by side.

If the parameter being monitored is temperature or humidity,
The monitoring means may include conduit forming means for forming a conduit for introducing gas in close proximity to the coil. When the temperature or humidity of the gas changes, the characteristic inductance or capacitance of the coil changes and the natural frequency of the coil changes.

The conduit forming means comprises a long tube. This tube is
It is disposed between each turn of the coil and is formed into a coil shape together with the coiled conductive wire.

As will be apparent to those skilled in the art, the monitoring means can be formed in a variety of ways. To this end, in another embodiment of the invention, the monitoring means comprises at least two spaced conductors arranged in the form of a two-wire transmission line or a coaxial cable.

If the monitored parameter is pressure or force, the spacing between the conductors or the effective length of the conductors is varied;
Changing the natural frequency of the monitoring means.

If the monitored parameter is temperature or humidity of the gas, the monitoring means comprises conduit forming means for forming a conduit. This conduit introduces gas into the space adjacent to the conductor.

It is also possible to arrange more than one conducting wire.

The conductors are elastically arranged spaced apart from each other and adjacent to each other. A gas conduit may be placed between adjacent conductors. The ends of some or all of the conductors can be joined to form an infinite coil. Alternatively, each conducting wire can be made to form a DC open circuit without being coupled. Alternatively, each conductor may be coupled to a separate impedance element. It is also possible to connect each end of adjacent conductors by a separate impedance element.

In connection with applying pressure or force, the conductors can be elastically spaced in a variety of ways. These conductors can therefore be fixed to an elastic flexible material.

This flexible material flexes as the monitored pressure or force changes, thus changing the spacing between the conductors. It is also possible to keep the spacing between the conductors constant and to vary the effective length of the conductors. In this case, the ends of the conductors are terminated at the shorted end of the spring load. In use, these terminals:
Vary in response to applied pressure or force, changing the effective length of the conductor.

As mentioned above, one way to vary the characteristic inductance and/or capacitance of the circuit of the monitoring means when used with a pressure transducer is to vary the spacing of the conductors or vary the length of the conductors. It is. However, this can also be achieved in other ways. For example, the electromagnetic values such as permittivity and magnetic permeability of the medium between each turn of the coil or between the conductors are varied while keeping the spacing and effective length of the conductors constant. in this case,
The monitoring means comprises a dielectric medium placed between each turn of the coil or between the conductors depending on the conditions. The dielectric constant of the dielectric medium is variable in response to changes in the pressure or force applied thereto, thereby changing the natural frequency of the monitoring means.

A transducer for monitoring a physical parameter provided in another aspect of the present invention includes the monitoring means, an excitation means for exciting the monitoring means, and a transducer for detecting the natural frequency of the monitoring means. and a detection means for detecting the detection.

The excitation means includes an excitation coil. This excitation coil is
In a wireless manner, said monitoring means is electrically and/or
or magnetically coupled to excite the monitoring means and cause it to oscillate at a natural frequency. Note that the excitation coil is not mechanically coupled to the monitoring means.

an excitation coil (or other energy transmission device that transmits energy in a wireless manner) for exciting the monitoring means and causing it to oscillate at a natural frequency;
Located sufficiently close to the monitoring means. It is desired that the monitoring means do not influence the excitation means and at the same time that the excitation means do not influence the monitoring means. For this reason, the excitation coil is loosely coupled to the monitoring means.

The transducer includes pulse generating means.

The pulse generating means generates a series of pulses at a repetition rate well below the natural frequency of the monitoring means.

Therefore, in use, damped vibrations are generated in the monitoring means.

The detection means includes a detection coil. This detection coil connects the monitoring means electrically and/or in a wireless manner.
or magnetically coupled. It is also desirable that this detection means is not mechanically connected to the monitoring means. Preferably, the monitoring means is unaffected by the detecting means, and the detecting means is preferably unaffected by the monitoring means. The detection coil is thus loosely coupled to the monitoring means.

The invention further provides a tire comprising a casing and said monitoring means rotatably mounted within said casing.

If the monitoring means comprises a coil, the invention also relates to a tire to which the coil is fixed. The monitoring means is in communication at least in part and preferably in whole with the tire. In use, pressure is applied to the tire. For this purpose, the monitoring means can be provided on the inner surface of the tire, preferably on the side wall of the inner surface of the tire.

The monitoring means can also be fixed to the tube of the tire or to the rim to which the tire is coupled.

As an extension of this form of the invention, the tire is coupled to a rim to form a wheel. Furthermore, the invention also relates to a vehicle equipped with a pressure quadrature transducer according to the invention.

The excitation means and detection means of the transducer may be located adjacent to the external surface of the side wall of the casing.

The transducer described above has a simple and sophisticated structure, and is strong and reliable.This transducer is extremely durable and well-balanced, making it suitable for use in tires, etc. Do not disturb the target.

In yet another form of the invention, an electrical passive monitoring means having a characteristic capacitance and inductance and a resistivity is excited such that it oscillates at a natural frequency, and the said characteristic is energized in response to changes in the monitored parameter. changing the natural frequency of the monitoring means in response to a change in the parameter by changing a capacitance or characteristic inductance, and indicating a change in the monitored parameter by detecting a change in the natural frequency of the monitoring means; Provided is a method for monitoring physical parameters, including:

As mentioned above, the monitoring means comprises a long conductive wire wound in the form of a coil of spaced turns. When the monitored parameter is pressure or force, the method includes changing the spacing of each turn of the coil to change the characteristic capacitance or inductance of the coil in response to the pressure or force applied to the coil. , thereby changing the natural frequency of the coil.

If the monitored parameter is the humidity or temperature of a gas, the method includes introducing the gas in close proximity to each turn of the coil and, depending on the humidity or temperature of the gas, changing the characteristic capacitance or temperature of the coil. including changing the inductance and thereby changing the natural frequency of the coil.

The method includes introducing the gas adjacent each turn of the coil by conduit forming means. The conduit forming means is wound with a length of conductive wire and placed between each turn of the coil.

Also, as mentioned above, when the monitoring means comprises at least two conductors arranged in the form of a two-wire transmission line or a coaxial cable, and the monitored parameter is pressure or force, the method comprises: The method includes changing the spacing between the conducting wires.

The method includes varying the effective length of the conductor with a spring-loaded tapered shorted terminal. The terminal is responsive to applied pressure or force.

The method of the invention includes introducing a gas into a space proximate to the electrical conductor when the monitored parameter is the temperature or humidity of the gas.

Where the monitoring means comprises a single conductor wound in the form of a coil with a plurality of spaced turns, and the monitored parameter is pressure or force, the method comprises: It includes varying the natural frequency of the coil by varying the permittivity or permeability of the medium between each turn.

The method of the invention includes placing a suitable material between each turn of said coil, said material expanding or compressing as a monitored force or pressure applied to said material changes. The dielectric constant of changes.

The method also includes introducing a suitable material between each turn of the coil to change the dielectric constant of the medium between each turn of the coil in proportion to the force or pressure being monitored.

The method of the invention comprises causing said monitoring means to damped oscillation by exciting said monitoring means with a series of pulses having a repetition rate suitably lower than the natural frequency of said monitoring means.

〔Example〕

The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of a transducer according to the invention. The transducer 10 is a pneumatic tire 12
The tire 12 is attached to a rim 14 to form a wheel for a vehicle (not shown).

Transducer 10 includes passive monitoring means. This passive monitoring means consists of a single AI wire, this copper wire forming a coil 11 consisting of a plurality of turns 16. roll 1
The diameter of coil 11 increases as it moves away from side wall 24 of tire 12, so that coil 11 has a substantially truncated conical shape. The winding 16 is secured to a flexible membrane 18 made of a flexible rubber or plastic material with suitable elasticity. membrane 18
The small diameter end 20 of the tire 12 is fixed to the inner surface of the side wall 24 of the tire 12. On the other hand, the large diameter end 22 of the membrane 18 is fixed to the inner surface of the tread portion 26 of the tire 12. □
Therefore, the membrane 18 spreads between the sidewall portion 24 and the tread portion 26 inside the tire 12 . Therefore, membrane 18
forms a chamber 28 with the portion of the inner surface of the tire 12 covered by the membrane 18. The ends of the first turn and the last turn of the coil 11 are open circuits. The ends of these first and last turns can also be terminated with separate impedance elements.

The coil 11 formed by turns 16 has only characteristic inductance and capacitance and vibrates at its natural frequency. These characteristic inductances and capacitances change depending on the winding 160 spacing. Therefore, when the spacing between the windings 16 changes due to deflection of the membrane 18, the natural frequency of the coil 11 also changes.

That is, as the pressure within the general chamber 30 formed by the tire 12 and the rim 14 changes in response to the pressure within the chamber 28, the membrane 18 deflects and the resulting natural frequency is representative of the pressure within the wheel.

The coil 11 formed by the winding 16 can be excited by an excitation coil 32 placed close to the wheel in alignment with the winding 16. Furthermore, when the coil 11 is excited, its frequency can be detected by a similar detection coil 34 (see FIG. 12). This detection coil 34 is also arranged adjacent to the wheel, but diametrically opposite to the excitation coil 32. As shown in FIG. 12, the excitation coil 32 includes an amplifier 3 connected to a pulse generator 38.
A pulse is supplied from 6. The amplifier 36 is connected to the tire 12
Because the pulses are delivered at a repetition rate substantially lower than the natural frequency of the coil 11, damped oscillations occur in the coil 11. Further, the excitation coil 32 and the coil 11 are loosely coupled electrically and magnetically, and the coil 11
is sufficiently excited without substantially affecting the signal within the excitation coil 32.

The detection coil 34 is connected to a series circuit including an amplifier 40 , a signal conditioning circuit 42 , a frequency/DC voltage converter 44 , and a comparator 46 . Therefore, the detection coil 34 is
The vibration of the coil 11 is detected and a representative signal is provided. Since the detection coil 34 and the coil 11 are loosely coupled electrically and magnetically, the detection coil 34 does not affect the natural frequency of the coil 11. The signal provided by the detection coil 34 is amplified by an amplifier 40 and sent to the circuit 4.
2 and converted into a DC voltage signal, then the comparator 4
6 is compared with a predetermined value. At this time, if the signal from the transducer 44 differs from the predetermined value, indicating that the pressure within the tire 12 has fallen below the predetermined value, the comparator 46 provides an alarm signal. Each element shown in FIG. 12 is standard and can be easily realized by those skilled in the art. Therefore, detailed explanation of these elements will be omitted.

FIG. 2 shows a transducer 50 according to another embodiment of the invention. This transducer 50 is similar to transducer 10 shown in FIG. 1, and each element has the same reference numeral.

However, in this embodiment, the turns 16 of the coil 11 are all in the same plane and have a spiral shape, and the membrane I8 is ring-shaped. The membrane 18 is secured at one end 20 to a sidewall portion 24 adjacent the rim 14 and at the other end 22 to a sidewall portion adjacent the tread portion 26, thereby forming a chamber 52. The operation of this embodiment is similar to that shown in FIG. 1, so a description of the operation will be omitted.

FIG. 3 shows a transducer 60 according to yet another embodiment of the invention. This transducer 60 is composed of four layers. A first layer of windings 16 is secured to the sidewall 24 and subsequent windings 16 are secured to the membrane 18. A series of chambers 54 are formed. The operation of this embodiment is also similar to that of transducers 10 and 50, and will be understood by those skilled in the art, so a description thereof will be omitted.

FIG. 4 shows a transducer 70 according to yet another embodiment of the invention, in which each turn 16 of the coil is separated by a member 72. In this embodiment, each turn 16 of the coil is separated by a member 72. Part 7
2 is made of a suitable dielectric material and has a predetermined dielectric constant. Member 72 is connected to a cylindrical base 78. An end ``of the base 78 is flexibly connected to the inner surface of the tread portion 26 by M76 to form a chamber.

The member 72 is attached in a suitable resilient manner, such as by a spring element 74, so that the position of the member 72 is
0, it changes depending on the pressure inside the tire 12.

The single-turn coil 79 is provided adjacent to the side wall portion 24 of the tire 12 and functions as a pickup. The operation of this transducer 70 is similar to the previously described embodiments, with the characteristic inductance and/or capacitance of the coil formed by turns 16 varying depending on the degree of expansion and contraction of member 72 between turns 16. do.

FIG. 5 shows a transducer 80 according to yet another embodiment of the invention. In this embodiment, coil 11
The winding 16 is fixed to the protrusion 82 . The protrusion 82 protrudes inward from the inner surface of the side wall portion 24 . In this example, when the pressure within the tire 12 changes, the deflection of the sidewall 24 changes, the spacing between turns 16 changes,
This changes the characteristic inductance and/or capacitance, and the natural frequency of the coil 11 changes.

FIG. 6 shows a transducer according to yet another embodiment of the invention, where each reference numeral is the same as previously described. In this embodiment, transducer 10 includes a coil 90 formed of a spiral circular winding 92 of conductive wire. As shown in FIG. 7, the windings 92 are arranged in layers. Each adjacent layer and adjacent turns of the coil 90 within each layer are connected to a hollow flexible tube 94.
separated by corresponding turns of . Flexible tube 94 is made of a non-conductive material, such as a synthetic plastic material. tube 9
4 separates adjacent turns of winding 92. tube 9
4 and the winding 92 are housed in a flexible potting resin 96 such as silicone rubber.

8 and 9 illustrate embodiments of transducer 10. FIG. In the embodiment of the invention shown in FIG. 8, wire 92 is wound in three layers, with each turn of an adjacent layer separated by a corresponding turn of tube 94. In the embodiment of the invention shown in FIG. Adjacent turns within the same layer are made of flexible potting resin 9
separated only by 6.

In FIG. 9, conductive wire 92 is placed around a central flexible tube 98. In FIG. Flexible tube 98 is made of a non-conductive material, such as a synthetic plastic material. The conductive wire 92 is held in place by the embedding resin 96 around the flexible tube 98 .

If the flexible tubes 94 or 98 are sealed, changes in the pressure of the air surrounding the transducer 10 will compress or expand the flexible tubes. The degree of compression or expansion produced is increased by the relative looseness of flexible tube 94 or 98 to allow compression.

The pressure applied to the transducer 10 is applied to the flexible tube 94.
or 98, the characteristic capacitance or inductance of the coil 90 changes, thereby changing the frequency of the coil 90.

The change in frequency of coil 90 is directly proportional to the pressure applied to coil 90 by the air within tire 12.

For example, a coil with a natural frequency of about 1600 KHz can be excited with pulses having a repetition rate of about 160 pulses of 7 seconds to generate suitably damped oscillations in the coil.

FIG. 11 shows a transducer 100, which is used to monitor the temperature or humidity of a gas. In this embodiment of the invention,
Transducer 100 includes passive monitoring means 102 having a plurality of conductors 104.

These conducting wires 104 are arranged parallel to each other and spaced apart from each other. A conduit forming means comprised of a long tube 106 is placed between adjacent conductors 104.

The gas whose temperature or humidity is to be monitored is introduced in close proximity to conductor 104 by tube 106 .

In use, as the temperature and/or humidity of the gas within tube 106 changes, the dielectric constant between adjacent conductors 104 changes, changing the natural frequency of transducer 100.

The transducer 100 is excited by an excitation coil and the natural frequency of the monitoring means 102 is detected by a detection coil similar to that described above.

Therefore, the excitation coil 32 and the detection coil 34 described above
can be used for transducer 100.

The circuit configurations of the coils 32 and 34 are as described above.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view showing a part of a wheel of a vehicle according to one embodiment of the present invention, and FIGS. 2 to 5 show other embodiments of the present invention, respectively. 6 is a partially sectional side view showing a pressure transducer according to another embodiment of the present invention, and FIGS. 7 to 9 are:
6 is a sectional view showing various embodiments of the transducer shown in FIG. 6, FIG. 10 is a partially sectional perspective view showing a tire having the transducer shown in FIG. 6, and FIG.
FIG. 12 is a perspective view of a transducer according to the invention for monitoring the temperature or humidity of a gas, and FIG. FIG. 2 is a block diagram showing a circuit for detecting vibrations generated therein. 10.50.60, 70.80. 100...Transducer, 11...Coil, 12...
- Tire, 14... Rim, 16... Coil winding, 18... Flexible membrane, 24...
Side wall portion, 26...Tread portion, 28...Chamber, 32...Excitation coil, 34...Detection coil, 36, 40...Amplifier, 38...Pulse generator, 42... Signal conditioning circuit, 44... Frequency/DC voltage converter, 46... Comparator. Margin below, 'ζ/ 6 ' Procedural amendment writing method) % formula % 1. Indication of the case 1988 Patent Application No. 166288 2. Name of the invention Physical parameter monitoring device and part 4. Address of the agent 105 Tokyo Toranomon-chome 8-10-5, Miyakominato-ku,
Date of amendment order @September 22, 1962 (shipment date) 6. Specification subject to amendment 7. Engraving of the statement of contents of the amendment (no change in content) 8. Engraving statement of catalog of attached documents 1 copy

Claims (1)

[Claims] 1. It has a specific resistance, a characteristic capacitance, and an inductance, and one of the characteristic capacitance and inductance is variable, so that the natural frequency changes according to changes in the monitored parameter. An electrically operable passive monitoring device used with a transducer to monitor a changing physical parameter. 2. A monitoring device according to claim 1, comprising a long conductive wire in the form of a coil, with a spacing between adjacent turns of the coil. 3. Each turn of the coil is elastically arranged with respect to each other;
A monitor device according to claim 2. 4. Arranging an elastic flexible membrane between each turn of the coil, fixing each turn of the coil to the flexible membrane, and during operation,
When the flexible membrane deflects under the effect of a monitored pressure or force, the spacing between each turn changes, the characteristic inductance or capacitance of the coil changes, and the natural frequency of the coil changes. A monitor device according to claim 3. 5. Conduit forming means for forming a conduit for introducing gas in proximity to the coil, the characteristic inductance or capacitance of the coil changing as the temperature or humidity of the gas changes, so that the characteristic inductance or capacitance of the coil changes. The monitor device according to claim 2, wherein the natural frequency changes. 6. The conduit forming means comprises a long tube, the tube is arranged between each turn of the coil, and the tube is formed into a coil shape together with the coiled conducting wire. monitoring equipment. 7. Monitoring device according to claim 1, comprising at least two spaced apart electrical conductors in the form of a two-wire transmission line or a coaxial cable. 8. When the monitored parameter is pressure or force, changing the spacing between the conductive wires or the effective length of the conductive wires changes the natural frequency of the monitoring means;
A monitor device according to claim 7. 9. When the parameter to be monitored is the temperature or humidity of the gas, a conduit forming means is provided for forming a conduit, and the gas is introduced into the space adjacent to the conducting wire by the conduit, claim 7. Monitoring equipment as described in Section. 10. A dielectric medium is disposed between each turn of the coil, and the natural frequency changes by changing the dielectric constant of the dielectric medium in response to a change in pressure or force applied to the dielectric medium, Monitor device according to scope 2. 11. Claim 7, wherein a dielectric medium is disposed between the conductive wires, and the natural frequency changes by changing the dielectric constant of the dielectric medium in accordance with the transformation of pressure or force applied to the dielectric medium. Monitoring device as described. 12. A physical parameter comprising a monitor means according to claim 1, an excitation means for exciting the monitor means, and a detection means for detecting the natural frequency of the monitor means. transducer for monitoring. 13. said excitation means comprises an excitation coil, said excitation coil being electrically and/or magnetically coupled to said monitoring means in a wireless manner for exciting said monitoring means and causing said monitoring means to oscillate at a natural frequency; The transducer according to claim 12, which oscillates. 14. Claim 14, comprising pulse generating means, said pulse generating means generating damped vibrations in said monitoring means by generating a series of pulses at a repetition rate sufficiently lower than the natural frequency of said monitoring means. The transducer according to item 13. 15. Transducer according to claim 12, wherein the detection means comprises a detection coil, which is electrically and/or magnetically coupled to the monitoring means in a wireless manner. 16. A tire comprising a casing and a monitor means according to claim 1, which is rotatably mounted in the casing together with the casing. 17. by exciting an electrical passive monitoring means having a characteristic capacitance and inductance and a resistivity such that it oscillates at a natural frequency and varying said characteristic capacitance or characteristic inductance in response to changes in the monitored parameter; , changing the natural frequency of the monitoring means according to a change in the parameter;
A method of monitoring a physical parameter comprising indicating a change in the monitored parameter by detecting a change in the natural frequency of said monitoring means. 18. Where the monitoring means comprises a long conductive wire in the form of a coil forming a plurality of spaced turns, and where the monitored parameter is pressure or force, in response to the pressure or force applied to the coil; 18. The method of claim 17, comprising varying the natural frequency of the coil by varying the spacing of each turn of the coil to vary the characteristic capacitance or inductance of the coil. 19. When said monitoring means comprises a long conductive wire in the form of a coil forming a plurality of spaced turns, and when said parameter to be monitored is humidity or temperature of a gas, said monitoring means comprises a length of conductive wire in the form of a coil forming a plurality of spaced turns, and when said parameter to be monitored is the humidity or temperature of a gas, said means proximate each turn of said coil. 18. The method according to claim 17, comprising changing the natural frequency of the coil by introducing the gas and changing the characteristic capacitance or inductance of the coil depending on the humidity or temperature of the gas. Method. 20. Introducing said gas in close proximity to each turn of said coil by means of a conduit forming means, said conduit forming means being wound with a length of conductive wire and disposed between each turn of said coil. The method according to scope item 19. 21. when said monitoring means comprises at least two conductors arranged in the form of a two-wire transmission line or a coaxial cable, and said monitored parameter is pressure or force;
20. The method of claim 19, comprising varying the spacing of the conductive wires. 22. When said monitoring means comprises at least two conductors arranged in the form of a two-wire transmission line or a coaxial cable, and said parameter to be monitored is the temperature or humidity of a gas, said 18. The method of claim 17, comprising introducing a gas. 23. When said monitoring means comprises a conductor in the form of a coil forming a plurality of spaced turns, and said monitored parameter is pressure or force, the dielectric constant of the medium between each turn of said coil; 18. The method of claim 17, comprising: changing the natural frequency of the coil by changing the magnetic permeability. 24, placing a suitable material between each turn of said coil, said material expanding or compressing to change the dielectric constant of said material as a monitored force or pressure applied to said material changes; 24. The method of claim 23, wherein: 25. Introducing a suitable material between each turn of said coil in proportion to the force or pressure being monitored to change the dielectric constant of the medium between each turn of said coil. The method according to paragraph 24. 26. The method of claim 17, comprising exciting the monitoring means with a series of pulses. 27, comprising causing said monitoring means to damped oscillation by exciting said monitoring means with a series of pulses having a repetition rate suitably lower than the natural frequency of said monitoring means. the method of.