Patent Application
20060042940
The present invention relates to an alcohol concentration detecting apparatus for detecting an alcohol concentration in a liquid to be inspected, for example, a gasoline and an alcohol concentration detecting method using the same, and an alcohol concentration detecting sensor manufacturing method.
Conventionally, for example, a so-called high-octane gasoline having an octane value increased such as lead or a benzene based compound, or a gasoline into which an antiknocking agent such as methyl tertiary butyl ether or methyl-t-butyl ether (MTBE) is mixed has been used for a car or the like in order to prevent knocking.
However, there is a possibility that the lead, the benzene based compound or the like might influence an environment. Moreover, it is said that the methyl tertiary butyl ether or the methyl-t-butyl ether (MTBE) is cancer-causing. For this reason, it has been desired to develop the high-octane gasoline and an antiknocking agent in place of the antiknocking agent constituted by the methyl tertiary butyl ether or the methyl-t-butyl ether (MTBE).
Therefore, it has been proposed that alcohol, for example, ethanol is added, as the antiknocking agent, in an amount of approximately 10 to 15% to a gasoline.
However, such ethanol is added so that a torque is reduced. By excessively adding a gasoline corresponding to the amount of addition of the ethanol, therefore, it is necessary to cause the torque to be constant.
For this reason, it has been desired to detect the concentration of alcohol contained in a gasoline.
As a method of detecting the concentration of alcohol, conventionally, an optical alcohol concentration measuring apparatus for detecting the concentration of alcohol by utilizing the refractive index of a light has been disclosed as in Japanese Laid-Open Patent Publication No. Hei 5(1993)-223733 (see paragraphs (0017) to (0030) and FIG. 1) (which will be hereinafter referred to as “Patent Document 1”).
More specifically, in an optical alcohol concentration measuring apparatus 100 in the Patent Document 1, a light which is transmitted from a light emitting portion 102 through a liquid and has a wavelength with such a property that an absorption into alcohol such as ethanol is hard to perform is received by a first light receiving portion 104. Then, a detection signal corresponding to an alcohol concentration in the liquid is output as shown in FIG. 19.
Moreover, a light, which is transmitted from a second light emitting portion 106 through the liquid and has another wavelength with such a property that the absorption into the alcohol is easy, is received by a second light receiving portion 108. Then, a detection signal corresponding to the alcohol concentration in the liquid is output.
Consequently, the detection signal sent from the first light receiving portion 104 is compared with the detection signal sent from the second light receiving portion 108 and the alcohol concentration in the liquid is measured in a measuring portion 110.
As described in “Electrostatic Capacitance Type Alcohol Concentration Sensor” (see Norio Mima, Ikuo Hayashi, Ichiro Hosoya, The Society of Automotive Engineers of Japan, Annual Congress Preliminary Printing Collection 936, 1993-10, pages 257 to 260) (which will be hereinafter referred to as “Non-Patent Document 1”), conventionally, an electrostatic capacitance type alcohol concentration sensor has been proposed.
In the Non-Patent Document 1, there has been proposed a method of measuring the concentration of methanol mixed into a gasoline from an electrostatic capacitance between electrodes at an oscillation frequency by utilizing a difference in a specific inductive capacity between the gasoline and the methanol (the gasoline has a specific inductive capacity of 2 and the methanol has a specific inductive capacity of 33.6), thereby detecting the concentration of the methanol.
An electrostatic capacitance type alcohol concentration sensor 200 according to the Non-Patent Document 1 has such a structure that an outer electrode 204 and a center electrode 206 are attached through an insulating resin 208 into a housing 202 as shown in FIG. 20.
Since the optical alcohol concentration measuring apparatus according to the Patent Document 1 utilizes a transmitted light, however, it is easily influenced by the composition of a gasoline. For example, in the case in which a liquid to be inspected is not transparent due to an impurity, moreover, a measurement cannot be carried out or an accurate measurement cannot be performed.
In the electrostatic capacitance type alcohol concentration sensor utilizing an electrostatic capacitance according to the Non-Patent Document 1, furthermore, a moisture is apt to enter alcohol and a short circuit is generated between electrodes if the moisture, an electrolyte or the like is present between the electrodes. Accordingly, an insulating treatment for the surface of the electrode is required and a structure thereof is complicated.
In this case, an electrostatic capacitance Cs is expressed in the following equation.
Cs=ε0(S/D)(εra(α/100εrg(1−α/100)) Equation 1
Herein, S represents an opposed area of an electrode, D represents a distance between the electrodes, ε0 represents a specific inductive capacity of a vacuum (8.854E-12F/m), εra represents a specific inductive capacity of alcohol, εrg represents a specific inductive capacity of a gasoline, and α represents an alcohol concentration (%).
As is apparent from the Equation, accordingly, it is preferable to increase the opposed area of the electrode to increase the electrostatic capacitance Cs in order to obtain the excellent results of the measurement. When the opposed area of the electrode is thus increased, however, the size of the electrostatic capacitance type alcohol concentration sensor itself is increased as in the Non-Patent Document 1. For this reason, handling, an application to a car and the like are also restricted in respect of a design.
In the electrostatic capacitance type alcohol concentration sensor according to the Non-Patent Document 1, furthermore, the sensor is to be connected to a body of a gasoline piping in a car or the like, for example. However, a noise such as an electromagnetic wave or the like which is generated from the body influences an alcohol concentration detecting circuit so that an accurate measurement cannot be carried out.
For this reason, an insulating structure is added to the connecting portion of the sensor and the piping or the whole large-sized sensor is to be put in an insulating shield container. Consequently, the apparatus becomes complicated and large-sized.
In consideration of such existing circumstances, it is an object of the present invention to provide an alcohol concentration detecting apparatus for detecting an alcohol concentration in a liquid to be inspected such as a gasoline which is small-sized and compact, can be installed everywhere and can have the degree of freedom of a design, has an excellent insulation between electrodes and is not influenced by a moisture, can carry out shielding in order not to be influenced by an electromagnetic wave generated from a body of a car or the like, and furthermore, can execute an accurate measurement for the alcohol concentration. Furthermore, it is an object to provide an alcohol concentration detecting method using the same apparatus, and an alcohol concentration detecting sensor manufacturing method.
In order to solve the problems and to attain the object in the conventional art described above, the present invention has been made and provides an alcohol concentration detecting apparatus in which an alcohol concentration in the liquid to be inspected is detected by introducing a liquid to be inspected between electrodes of an alcohol concentration detecting sensor and by measuring a change in a specific inductive capacity of the liquid to be inspected between the electrodes with an oscillation frequency,
By such a structure, it is possible to reduce a distance between the electrodes by using the electrode wiring pattern formed on the base material resin film. As is apparent from Equation 2 which will be described below, therefore, an electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor is constituted by the base material resin film, the electrode wiring pattern formed on the base material resin film, and the insulating resin covering the surface of the electrode wiring pattern. Therefore, the sensor itself is flexible, thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Furthermore, the surface of the electrode wiring pattern is covered with the insulating resin. Therefore, an insulation between the electrodes is excellent and is not influenced by a moisture, and shielding can be carried out in order to prevent the influence of an electromagnetic wave generated from the body of a car or the like. Furthermore, an accurate measurement for the alcohol concentration can be executed.
Moreover, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with the passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
In addition, the alcohol concentration detecting apparatus according to the present invention is characterized in that the alcohol concentration detecting sensor body is stuck onto a substrate.
By such a structure, the alcohol concentration detecting sensor body is stuck onto the substrate. Therefore, it is easy to assemble and attach the alcohol concentration detecting sensor body into the apparatus.
Furthermore, the alcohol concentration detecting apparatus according to the present invention is characterized in that the electrode wiring pattern is obtained by selectively etching a conductive metallic foil laminated on one of surfaces of the base material resin film, thereby forming a wiring pattern taking a predetermines shape.
By such a structure, it is possible to obtain an electrode wiring pattern having a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by etching. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Moreover, the present invention provides an alcohol concentration detecting apparatus in which an alcohol concentration in the liquid to be inspected is detected by introducing a liquid to be inspected between electrodes of an alcohol concentration detecting sensor and by measuring a change in a specific inductive capacity of the liquid to be inspected between the electrodes with an oscillation frequency,
By such a structure, it is possible to reduce a distance between the electrodes by using the electrode wiring pattern formed on the substrate. As is apparent from the Equation 2 which will be described below, therefore, an electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor is constituted by the substrate, the electrode wiring pattern formed on the substrate, and the insulating coat covering the surface of the electrode wiring pattern. Therefore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Furthermore, the surface of the electrode wiring pattern is covered with the insulating coat. Therefore, an insulation between the electrodes is excellent and is not influenced by a moisture, and shielding can be carried out in order to prevent the influence of an electromagnetic wave generated from the body of a car or the like. Furthermore, an accurate measurement for the alcohol concentration can be executed.
Moreover, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with the passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
In addition, the substrate is provided. Therefore, it is easy to assemble and attach the alcohol concentration detecting sensor into the apparatus.
Furthermore, the alcohol concentration detecting apparatus according to the present invention is characterized in that the electrode wiring pattern is obtained by selectively etching a conductive metallic thin film formed on one of surfaces of the substrate by sputtering, thereby forming a wiring pattern taking a predetermines shape.
By such a structure, it is possible to obtain an electrode wiring pattern having a thickness of 0.1 to 5 μm by sputtering at a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by the sputtering. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Moreover, the alcohol concentration detecting apparatus according to the present invention is characterized in that the insulating coat is formed by chemical vapor deposition (CVD).
By such a structure, it is possible to obtain, by the chemical vapor deposition (CVD), a very minute and thin insulating coat which is not influenced by the liquid to be inspected such as a gasoline or alcohol, for example, SiO2, Al2O3 and the like. Thus, the sensor itself can be thin, very small and compact.
Furthermore, the alcohol concentration detecting apparatus according to the present invention is characterized in that the electrode wiring pattern has such a shape that positive and negative electrodes which are comb-toothed are alternately intricate.
By such a structure, the positive and negative electrodes which are comb-toothed are formed to be alternately intricate. Therefore, the electrodes having a very small distance therebetween can be provided to be compact as a whole.
Accordingly, it is possible to obtain an electrode wiring pattern having a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by etching and sputtering, respectively. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the sensor itself is thinner, much smaller and more compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Moreover, the present invention provides an alcohol concentration detecting method of detecting an alcohol concentration in a liquid to be inspected by using the alcohol concentration detecting apparatus according to any of the aspects described above,
By such a structure, it is possible to reduce a distance between the electrodes by using the electrode wiring pattern formed on the base material resin film or the substrate. As is apparent from the Equation 2 which will be described below, therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Furthermore, the surface of the electrode wiring pattern is covered with the insulating resin or the insulating coat. Therefore, an insulation between the electrodes is excellent and is not influenced by a moisture, and shielding can be carried out in order to prevent the influence of an electromagnetic wave generated from the body of a car or the like. Furthermore, an accurate measurement for the alcohol concentration can be executed.
Moreover, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with the passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
In addition, the alcohol concentration detecting method according to the present invention is characterized in that the liquid to be inspected is a gasoline containing alcohol.
By such a structure, the alcohol concentration in the gasoline can be detected accurately and rapidly, and it is possible to control a torque to be constant by excessively adding a gasoline corresponding to the amount of addition of alcohol, for example, ethanol as an antiknocking agent.
Furthermore, the present invention provides a method of manufacturing an alcohol concentration detecting sensor, comprising:
By such a structure, it is possible to obtain an electrode wiring pattern having a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm. Consequently, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained. Furthermore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
In addition, the alcohol concentration detecting sensor manufacturing method according to the present invention comprising a substrate sticking step of sticking the alcohol concentration detecting sensor body obtained at the insulating resin applying step onto a substrate.
By such a structure, the alcohol concentration detecting sensor body is stuck onto the substrate. Consequently, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the alcohol concentration detecting sensor body can easily be assembled and attached into the apparatus.
Furthermore, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the base material resin film is a polyimide resin film.
By such a structure, the electrode wiring pattern can be formed on the flexible, thin and small polyimide resin film. Consequently, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the sensor itself is thin, very small and compact, and can be installed everywhere and the degree of freedom of a design can be increased.
Moreover, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the conductive metallic foil is a copper foil.
By such a structure, the electrode wiring pattern can be formed by the copper foil. Consequently, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which a high conductivity can be obtained and an alcohol concentration can be detected very accurately and rapidly.
In addition, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the insulating resin is constituted by at least one selected from an urethane resin, a polyimide resin and an epoxy type resin.
By using such a resin as the insulating resin, it is possible to easily apply the insulating resin onto the surface of the electrode wiring pattern.
Moreover, the present invention provides a method of manufacturing an alcohol concentration detecting sensor, comprising:
By such a structure, it is possible to obtain an electrode wiring pattern having a thickness of 0.1 to 5 μm by sputtering at a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm. Therefore, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained. Furthermore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Moreover, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the substrate is constituted by at least one selected from ceramics, glass and a resin substrate.
By such a structure, a conductive metallic thin film constituting the electrode wiring pattern can easily be formed, through sputtering, on the substrate constituted by such a material, and furthermore, the substrate formed by the same material is provided. Consequently, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor which can easily be assembled and attached into the apparatus.
Furthermore, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the conductive metallic thin film is constituted by at least one selected from platinum, nickel, copper and titanium.
By such a structure, it is possible to easily form the conductive metallic thin film constituting the electrode wiring pattern on the substrate by sputtering.
In addition, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the insulating coat is constituted by at least one minute insulating coat selected from SiO2, Al2O3 and the like.
By such a structure, it is possible to easily form the insulating coat on the surface of the electrode wiring pattern by chemical vapor deposition (CVD).
Moreover, the alcohol concentration detecting sensor manufacturing method according to the present invention is characterized in that the electrode wiring pattern has such a shape that positive and negative electrodes which are comb-toothed are alternately intricate.
By such a structure, the positive and negative electrodes which are comb-toothed are formed to be alternately intricate. Therefore, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the electrodes having a very small distance therebetween can be provided to be compact as a whole, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
An embodiment (example) of the present invention will be described below in more detail with reference to the drawings.
As shown in FIGS. 1 to 4, an alcohol concentration detecting apparatus 10 according to the present invention comprises an alcohol concentration detecting apparatus body 12, and a first passage 14 and a second passage 16 which are formed in the alcohol concentration detecting apparatus body 12.
As shown in an arrow of
On the other hand, in a state in which the liquid to be inspected which flows into the first passage 14 through the inspected liquid inlet port 18 then stays temporarily in the alcoholic content detecting chamber 56, the concentration of the alcohol content is detected by an alcohol concentration detecting sensor 58 if the liquid to be inspected contains alcohol. Then, the same liquid is then discharged from the alcohol content detecting chamber 56 through an inspected liquid discharge port 54 of the second passage 16.
In the alcohol concentration detecting sensor 58, a difference in an electrostatic capacitance is utilized depending on a difference between the specific inductive capacity of alcohol contained in the liquid to be inspected and the specific inductive capacity of the liquid to be inspected based on the following Equation 2.
Cs=ε0(S/D)(εra(α/100)+εrb(1−α/100)) Equation 2
Herein, S represents an opposed area of an electrode, D represents a distance between the electrodes, ε0 represents a specific inductive capacity of a vacuum (8.854E-12F/m), εra represents a specific inductive capacity of alcohol, εrb represents a specific inductive capacity of a liquid to be inspected, and α represents an alcohol concentration (%).
More specifically, as shown in a graph of
Moreover, the alcohol concentration detecting apparatus 10 according to the present invention which uses the alcohol concentration detecting sensor 58 comprises a detecting control portion 76 having a structure shown in a diagram of
As shown in
Moreover, resistors R1 to R3 are connected to a negative 82a of a power supply 82, and furthermore, the negative input of the amplifier 78 is connected between R1 and R2. Furthermore, the positive input of the amplifier 80 is connected between R2 and R3, and an end of R3 is grounded G2.
The outputs of the amplifiers 78 and 80 are connected to S and R inputs of a flip-flop circuit 84, respectively. The output of the flip-flop circuit 84 is input to the frequency counter of a computer 86.
Furthermore, the wiring of one of the electrodes of the alcohol concentration detecting sensor 58 branches and is connected to a positive 82b of the power supply 82 through resistors RA and RB. A transistor 88 is connected between the resistors RA and RB, and the output of the transistor is connected between the output of the flip-flop circuit 84 and the computer 86. G3 denotes a ground of the transistor 88.
In the detecting control portion 76 having such a structure, a square-wave voltage shown in
As is expressed in the following Equation 3, consequently, a relationship between an oscillation frequency f and an electrostatic capacitance Cs is obtained.
1/T=f=RA/(RA+2RB)·1/Cs(Hz) Equation 3
In this case, it is possible to determine an amplitude T by properly setting a duty ratio/(RA+2RB). In the present example, 1.44 was employed for the duty ratio.
From such a relationship, a correlation is taken based on the graph of
The data in
As is apparent from the Equation 2, in order to obtain the excellent result of a measurement, it is preferable that the distance D between electrodes should be reduced to increase the electrostatic capacitance Cs.
In the alcohol concentration detecting apparatus 10 according to the present invention, therefore, the alcohol concentration detecting sensor 58 is constituted in the following manner.
More specifically,
As shown in FIGS. 9 to 12, the alcohol concentration detecting sensor 58 includes an alcohol concentration detecting sensor body 11 constituted by a base material resin film 92, electrode wiring patterns 94 and 96 formed on the base material resin film 92, and an insulating resin 98 covering the surfaces of the electrode wiring patterns 94 and 96. The alcohol concentration detecting sensor body 11 is stuck to a substrate 13 with an adhesive which is not shown.
In this case, it is preferable that a polyimide resin film should be used for the base material resin film 92 in consideration of a flexibility, a chemical resistance and the like. As shown in
Furthermore, the electrode wiring pattern 94 on a positive side and the electrode wiring pattern 96 on a ground (a negative side) have such shapes that positive electrodes 94a and negative electrodes 96a which are comb-toothed are alternately intricate, respectively. In
By such a structure, a plurality of electrodes having a very small distance therebetween can be provided to be compact as a whole.
In this case, while a length L1 of the electrode is not particularly restricted as shown in
While a width W1 of each of the positive electrode 94a and the negative electrode 96a is not particularly restricted as shown in
While the numbers of the positive electrodes 94a and the negative electrodes 96a which are comb-toothed are not particularly restricted, moreover, in consideration of the electrostatic capacitance, they are preferably equal to or larger than 1, and more preferably, are more increased. In the present example, 64 pairs (128 in total) comb-toothed electrodes were used.
While a thickness T2 of each of the electrode wiring patterns 94 and 96 is not particularly restricted as shown in
In this case, the electrode wiring patterns 94 and 96 are obtained by selectively etching a conductive metallic foil laminated on one of the surfaces of the base material resin film 92 to form wiring patterns taking predetermined shapes as will be described below.
Although such a conductive metallic foil is not particularly restricted, a copper foil is preferable. Consequently, a high conductivity can be obtained and the concentration of alcohol can be detected very accurately and rapidly.
Furthermore, it is preferable that the insulating resin 98 should be formed by at least one insulating resin selected from an urethane resin, a polyimide resin and an epoxy type resin.
By using such a resin as the insulating resin 98, it is possible to easily apply the insulating resin onto the surfaces of the electrode wiring patterns 94 and 96.
While a thickness T3 of the insulating resin 98 is not particularly restricted as shown in
While the material of the substrate 13 is not particularly restricted, furthermore, in consideration of a specific inductive capacity, it is possible to employ a glass substrate, a ceramics substrate, a resin substrate or the like. Although the thickness is not particularly restricted, it is preferably set to be 100 to 1000 μm, and more preferably, 250 to 600 μm in consideration of an insulating property, a strength and the like. In the present example, a thickness of 360 μm was employed.
By such a structure, it is possible to reduce the distance between the electrodes by using the electrode wiring patterns 94 and 96 formed on the base material resin film 92. As is apparent from the Equation 2, therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor 58 is constituted by the base material resin film 92, the electrode wiring patterns 94 and 96 formed on the base material resin film 92, and the insulating resin 98 covering the surfaces of the electrode wiring patterns 94 and 96. For this reason, the sensor itself is flexible, thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be enhanced.
Since the surfaces of the electrode wiring patterns 94 and 96 are covered with the insulating resin 98, furthermore, an insulation between the electrodes can be enhanced and is not influenced by a moisture, and shielding can be carried out so as not to be influenced by an electromagnetic wave generated from a body of a car or the like. Furthermore, the alcohol concentration can be measured accurately.
Moreover, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
With reference to
As shown in
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According to the method of manufacturing the alcohol concentration detecting sensor 58 of the alcohol concentration detecting apparatus according to the present invention, it is possible to obtain an electrode wiring pattern in which a distance between electrodes is very small, for example, approximately 5 μm to 50 μm. Therefore, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the electrostatic capacitance Cs can be increased and the excellent result of the measurement can be obtained. Furthermore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be enhanced.
The alcohol concentration detecting sensor 58 according to the present example has basically the same structure as that of the alcohol concentration detecting sensor 58 according to the example shown in FIGS. 9 to 12. Therefore, the same components are indicated as the reference numerals having a dash and detailed description thereof will be omitted.
The alcohol concentration detecting sensor 58 according to the present example comprises a substrate 92′, electrode wiring patterns 94′ and 96′ formed on the substrate 92′, and an insulating coat 98′ covering the surfaces of the electrode wiring patterns 94′ and 96′.
In this case, the electrode wiring patterns 94′ and 96′ are obtained by selectively etching a conductive metallic thin film formed on one of the surfaces of the substrate 92′ through sputtering to provide a wiring pattern taking a predetermined shape.
While such a conductive metallic thin film is not particularly restricted, nickel, copper, platinum or the like can be used and the platinum is desirably used in consideration of an oxidation resistance or the like.
While a thickness T2 of each of the electrode wiring patterns 94′ and 96′ is not particularly restricted as shown in
While the material of the substrate 92′ is not particularly restricted, furthermore, in consideration of the fact that the material is not influenced by sputtering or the like, a glass substrate, a ceramics substrate such as alumina, a resin substrate or the like can be employed. While the thickness is not particularly restricted, it is preferably set to be 100 to 1000 μm, and more preferably, 250 to 600 μm in consideration of an insulating property, a strength or the like. In the present example, a thickness of 360 μm was used. A size depends on the size of a sputtering device, and desirably, 2-inch and 4-inch square sizes can be used.
While the insulating coat 98′ is not particularly restricted, moreover, it is preferably constituted by at least one minute insulating coat selected from SiO2, Al2O3 and the like.
In this case, it is preferable that the insulating coat 98′ should be formed by chemical vapor deposition (CVD).
By such a structure, it is possible to obtain, by the chemical vapor deposition (CVD), a very minute and thin insulating coat which is not influenced by a liquid to be inspected such as a gasoline or alcohol, for example, SiO2, Al2O3 or the like, and the sensor itself can be thin, very small and compact.
While a thickness T3 of the insulating resin 98′ is not particularly restricted as shown in
By such a structure, it is possible to reduce the distance between the electrodes by using the electrode wiring patterns 94′ and 96′ formed on the substrate 92′. As is apparent from the Equation 2, therefore, the electrostatic capacitance Cs can be increased and the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor is constituted by the substrate 92′, the electrode wiring patterns 94′ and 96′ formed on the substrate 92′, and the insulating coat 98′ covering the surfaces of the electrode wiring patterns 94′ and 96′. For this reason, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be enhanced.
Since the surfaces of the electrode wiring patterns are covered with the insulating coat 98′, furthermore, an insulation between the electrodes can be enhanced and is not influenced by a moisture, and shielding can be carried out so as not to be influenced by an electromagnetic wave generated from a body of a car or the like. Furthermore, the alcohol concentration can be measured accurately.
Moreover, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
In addition, the substrate 92′ is provided. Therefore, it is easy to assemble and attach the alcohol concentration detecting sensor into the apparatus.
Furthermore, it is possible to obtain an electrode wiring pattern having a thickness of 0.1 to 5 μm by sputtering at a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by the sputtering. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
With reference to
As shown in
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As shown in
By such a structure, it is possible to obtain an electrode wiring pattern having a thickness of 0.1 to 5 μm by the sputtering at a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm. Therefore, it is possible to easily supply, on a large scale, an alcohol concentration detecting sensor in which the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained. Furthermore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
While the preferred examples of the present invention have been described above, the present invention is not restricted thereto. For example, while the description has been given to the case in which the alcohol concentration in the gasoline is detected in the examples, the present invention can also be applied to the case in which the concentration of alcohol in another liquid to be inspected is to be detected. Thus, various changes can be made without departing from the scope of the present invention.
(Advantage of the Invention)
According to the present invention, it is possible to reduce a distance between the electrodes by using the electrode wiring pattern formed on the base material resin film. As is apparent from the Equation 2, therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor is constituted by the base material resin film, the electrode wiring pattern formed on the base material resin film, and the insulating resin covering the surface of the electrode wiring pattern. Therefore, the sensor itself is flexible, thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Furthermore, the surface of the electrode wiring pattern is covered with the insulating resin. Therefore, an insulation between the electrodes is excellent and is not influenced by a moisture, and shielding can be carried out in order to prevent the influence of an electromagnetic wave generated from the body of a car or the like, and furthermore, an accurate measurement for the alcohol concentration can be executed.
According to the present invention, moreover, it is possible to obtain an electrode wiring pattern having a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by etching. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
According to the present invention, furthermore, it is possible to reduce a distance between the electrodes by using the electrode wiring pattern formed on the substrate. As is apparent from the Equation 2 described above, therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
In addition, the alcohol concentration detecting sensor is constituted by the substrate, the electrode wiring pattern formed on the substrate, and the insulating coat covering the surface of the electrode wiring pattern. Therefore, the sensor itself is thin, very small and compact, and can be installed everywhere so that the degree of freedom of a design can be increased.
Moreover, the surface of the electrode wiring pattern is covered with the insulating coat. Therefore, an insulation between the electrodes is excellent and is not influenced by a moisture, and shielding can be carried out in order to prevent the influence of an electromagnetic wave generated from the body of a car or the like. Furthermore, an accurate measurement for the alcohol concentration can be executed.
According to the present invention, furthermore, it is possible to obtain an electrode wiring pattern having a thickness of 0.1 to 5 μm by sputtering at a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by the sputtering. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
According to the present invention, moreover, it is possible to obtain, by chemical vapor deposition (CVD), a very minute and thin insulating coat which is not influenced by a liquid to be inspected such as a gasoline or alcohol, for example, SiO2, Al2O3 or the like. Thus, the sensor itself can be thin, very small and compact.
Furthermore, the electrode does not directly come in contact with the liquid to be inspected such as a gasoline. Therefore, a defective operation can be prevented from being caused by a deterioration with the passage of time, foreign matters in the gasoline or the like. Thus, it is possible to detect the alcohol concentration accurately and rapidly.
In addition, the substrate is provided. Therefore, it is easy to assemble and attach the alcohol concentration detecting sensor into the apparatus.
According to the present invention, moreover, the positive and negative electrodes which are comb-toothed are formed to be alternately intricate. Therefore, the electrodes having a very small distance therebetween can be provided to be compact as a whole.
Accordingly, it is possible to obtain an electrode wiring pattern having a very small distance between the electrodes, for example, within a range of approximately 5 μm to 50 μm by sputtering, respectively. Therefore, the electrostatic capacitance Cs can be increased so that the excellent result of the measurement can be obtained.
According to the present invention, furthermore, the alcohol concentration in the gasoline can be detected accurately and rapidly. Moreover, it is possible to control a torque to be constant by excessively adding a gasoline corresponding to the amount of addition of alcohol, for example, ethanol as an antiknocking agent. Thus, the present invention can produce many remarkable and peculiar functions and advantages, which is very excellent.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2002-286668 | Sep 2002 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP03/12504 | 9/30/2003 | WO | 3/29/2005 |
