JP2006291143A - Apparatus for reforming fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for reforming fuel, unaffected with liquid level and of a method of reforming fuel with ultrasonic application. <P>SOLUTION: An ultrasonic oscillation means (an ultrasonic oscillator 2, a driving circuit 3) oscillating an ultrasonic wave SW from the bottom surface (a bottom outer surface 4a) and an ultrasonic frequency-variable means (a reflected wave detector 5, a control means 6) changing frequency f of the ultrasonic SW from the ultrasonic oscillation means (the ultrasonic oscillator 2, the driving circuit 3) corresponding to liquid level H of a fuel F in the fuel container 4 are set on the bottom surface (the bottom outer surface 4a) of the fuel container 4. The ultrasonic oscillation means (the ultrasonic oscillator 2, the driving circuit 3) generates stationary wave of the fuel F in the fuel container 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel reformer that reforms fuel by applying ultrasonic waves.

  2. Description of the Related Art Conventionally, there is a technique for reforming a fuel by applying ultrasonic waves to the fuel. In this technique, ultrasonic waves are applied to the fuel, and the bond of the fuel is dissociated and softened by pressure amplitude energy transmitted through the fuel molecules. Alternatively, cavitation is generated in the fuel by the applied ultrasonic wave, and the bond of the fuel is dissociated and softened by the decay energy.

  For example, the following Patent Documents 1 to 3 disclose techniques for reforming fuel by providing an ultrasonic transducer in a container and applying ultrasonic waves to the fuel in the container.

JP 2002-308603 A JP 2003-105343 A Japanese translation of PCT publication No. 2003-524061

  However, when an ultrasonic vibrator is provided in a container as in the conventional technique described above, the position and quantity of reforming efficiency change depending on the remaining amount of fuel in the container. Cannot be fully utilized. This is because the amount of fuel supplied into the container is not always constant, although the softening of the fuel is efficiently performed at a specific portion of the ultrasonic waveform (specifically, the portion of the displacement node). In addition, since the remaining amount changes as the fuel is used, the number and position of the nodes of the ultrasonic waveform vary depending on the distance from the ultrasonic transducer to the liquid level of the fuel (that is, the liquid level height). This is because it changes and sufficient reforming is not performed.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a fuel reforming apparatus that can improve the inconvenience of the conventional example and can perform sufficient fuel reforming without being affected by the fuel level. .

  In order to achieve the above object, according to the first aspect of the present invention, the ultrasonic oscillation means for oscillating ultrasonic waves from the bottom surface is disposed on the bottom surface of the fuel container, and the liquid level of the fuel in the fuel container is adjusted. Accordingly, ultrasonic frequency variable means for changing the frequency of ultrasonic waves from the ultrasonic oscillator means is provided.

  According to the fuel reforming apparatus of the first aspect, the ultrasonic wave having the optimum frequency corresponding to the fuel level can be irradiated to the fuel and reflected effectively from the fuel level. Fuel reforming can be sufficiently performed without being affected by the liquid level, that is, according to the change in the liquid level. In particular, as in the invention described in claim 4, efficient fuel reforming can be sufficiently performed by generating a standing wave in the fuel in the fuel container, that is, up to the fuel level. .

  In order to achieve the above object, according to the second aspect of the present invention, an ultrasonic oscillation means for oscillating ultrasonic waves from the bottom surface is disposed on the bottom surface of the fuel container, and ultrasonic waves from the ultrasonic oscillation means are provided. An ultrasonic reflection plate for reflection is provided at a predetermined position in the fuel container.

  According to the fuel reforming apparatus of the second aspect, since the distance between the ultrasonic oscillating means and the ultrasonic reflector is fixed, the ultrasonic reflector at a predetermined position regardless of the liquid level of the fuel. Can reflect ultrasonic waves. For this reason, the fuel can be sufficiently reformed without being affected by the height of the liquid level by irradiating the ultrasonic wave with a certain optimum frequency to the fuel and reflecting it with the ultrasonic reflector. Even in such a case, as in the invention described in claim 4, efficient fuel reforming is sufficiently achieved by generating a standing wave in the fuel in the fuel container, that is, up to the ultrasonic reflector. Can be done.

  In order to achieve the above object, in the invention described in claim 3, an ultrasonic oscillation means for oscillating ultrasonic waves from the side surface is provided on the side surface of the fuel container.

  According to the fuel reforming apparatus of the third aspect, the other side surface of the fuel container can be used as an ultrasonic reflector. Further, the ultrasonic wave oscillated from the side surface of the fuel container is not affected by the liquid level of the fuel. Therefore, the fuel reforming apparatus according to claim 3 can perform sufficient fuel reforming without being influenced by the liquid level. Even in such a case, as in the invention described in claim 4, efficient fuel reforming can be achieved by generating a standing wave in the fuel in the fuel container, that is, between each side surface of the fuel container. Well done.

  The fuel reforming apparatus according to the present invention can sufficiently perform fuel reforming without being affected by the liquid level height even if the liquid level changes as the fuel is used.

  Embodiments of a fuel reformer according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

  A fuel reformer according to a first embodiment of the present invention will be described with reference to FIG. Reference numeral 1 in FIG. 1 indicates the fuel reformer of the first embodiment.

  First, the fuel reformer 1 is provided with an ultrasonic oscillator that oscillates the ultrasonic wave SW. In the first embodiment, the ultrasonic oscillator 2 that oscillates the ultrasonic wave SW and the drive circuit 3 that drives the ultrasonic vibrator 2 constitute ultrasonic oscillating means.

  Here, the ultrasonic transducer 2 of the first embodiment is provided on the bottom surface of the fuel container 4 so that the vibration surface 2 a thereof is parallel to the liquid level Fs of the fuel F in the fuel container 4. More specifically, the ultrasonic vibrator 2 is installed on a part of the outer surface (hereinafter referred to as “bottom outer wall surface”) 4 a on the bottom surface of the fuel container 4.

  In addition, as the drive circuit 3 according to the first embodiment, one that can change the ultrasonic frequency f of the ultrasonic transducer 2 steplessly is used.

  Further, in this fuel reformer 1, the frequency of the ultrasonic wave SW (hereinafter referred to as "ultrasonic frequency") f oscillated from the ultrasonic oscillation means is set according to the liquid level height H of the fuel F. The ultrasonic frequency variable means for oscillating the ultrasonic wave SW from the ultrasonic wave oscillating means at the ultrasonic frequency f is provided. Specifically, the ultrasonic frequency varying means according to the first embodiment includes a reflected wave detecting means 5 for detecting a reflected wave of the ultrasonic wave SW from the liquid level Fs of the fuel F in the fuel container 4, and the reflected wave detecting means. And a control means 6 for setting the ultrasonic frequency f based on the detection signal 5.

  Here, the reflected wave detecting means 5 has the same position as the above-described ultrasonic vibrator 2 on the bottom outer wall surface 4a of the fuel container 4, that is, the distance between the detecting portion 5a and the liquid level Fs of the fuel F. It arrange | positions in the position equivalent to the distance between the liquid level Fs and the vibration surface 2a of the ultrasonic transducer | vibrator 2. FIG. Here, the reflected wave detecting means 5 is arranged in the vicinity of the ultrasonic transducer 2 on the bottom outer wall surface 4 a of the fuel container 4. As the reflected wave detection means 5 of the first embodiment, for example, a reflected wave detection microphone is used.

  For example, when the fuel container 4 is a fuel tank of an automobile, an electronic control unit (ECU) mounted on the vehicle may be used as the control means 6.

  In the first embodiment, the control means 6 sets an ultrasonic frequency fb optimum for fuel reforming according to the liquid level height H of the fuel F in the fuel container 4, and at the optimum ultrasonic frequency fb The drive circuit 3 is controlled to oscillate the ultrasonic wave SW from the ultrasonic vibrator 2.

  Here, the liquid surface height H is obtained by the control means 6 from the following equation 1 using the detection signal of the reflected wave detection means 5 described above. In Equation 1, “T” indicates that after the ultrasonic wave SW is irradiated, the reflected wave from the liquid surface Fs of the fuel F of the ultrasonic wave SW is an inner surface (hereinafter referred to as “inside the bottom portion”) It is referred to as “wall surface”.) Time until reaching 4b, that is, reciprocation time until the irradiated ultrasonic wave SW returns to the bottom inner wall surface 4b. Further, “a” is the speed of sound of the ultrasonic wave SW in the fuel, and is a set value determined in advance for each fuel F to be used.

    H = (T · a) / 2 (1)

  When measuring the liquid level height H, the control means 6 of the first embodiment gives an instruction to the drive circuit 3 to oscillate the ultrasonic wave SW from the ultrasonic vibrator 2 with a pulse signal, Based on the detection signal from the reflected wave detection means 5 that detects the reflected wave of the ultrasonic wave SW, the time T required for the round trip path (2H) of the ultrasonic wave SW is calculated. And this control means 6 substitutes the time T in the said Formula 1, and calculates | requires the present liquid level height H. FIG. Here, this control means 6 may perform the measurement of the liquid level height H every predetermined time, or may always perform it.

  The liquid level height H may be obtained from a detection signal of a measuring means using a float or the like that measures the remaining amount of fuel F, for example. In such a case, the reflected wave detection means 5 becomes unnecessary.

  The optimum ultrasonic frequency fb described above is a frequency f that generates a standing wave of the ultrasonic wave SW from the bottom inner wall surface 4b of the fuel container 4 to the liquid level Fs of the fuel F. Here, In the meantime, the frequency f is set to be an integer n times the half wavelength of the wavelength of the ultrasonic wave SW (hereinafter referred to as “ultrasonic wave wavelength”) λ.

  That is, by adjusting the ultrasonic wavelength λ and the integer n corresponding to the liquid level height H satisfying the relationship of the following formula 2 and oscillating the ultrasonic wave SW, the traveling wave and the reflected wave from the liquid level Fs are obtained. Is generated between the bottom inner wall surface 4b of the fuel container 4 and the liquid level Fs of the fuel F.

    H = n · (λ / 2) (2)

  In the first embodiment, the ultrasonic transducer 2 oscillates based on the following formula 4 obtained by substituting λ (= 2H / n) of the formula 2 into the following formula 3. The control means 6 obtains the ultrasonic frequency f of the ultrasonic wave SW.

    f = a / λ (3)

    f = a / λ = (a · n) / 2H (4)

  Specifically, the control means 6 obtains an ultrasonic frequency f by substituting the measured current liquid level height H and a predetermined integer n into the above equation 4, and determines this according to the liquid level height H. It is set as the optimum ultrasonic frequency fb of the ultrasonic wave SW that can generate a standing wave.

  Here, the above-described integer n may be prepared as a predetermined value determined in advance for each fuel container 4, for example, may be prepared as a variable value that is variable according to the liquid level height H. Good. In any case, the integer n is preferably a value with the best reforming efficiency obtained by experiment or simulation, for example.

  For example, when the speed of sound a of the ultrasonic wave a = 1500 (m / s), the integer n = 4, and the liquid level height H = 150 mm, these are substituted into Equation 4 to obtain the ultrasonic frequency f = 20 kHz. The control means 6 sets the ultrasonic frequency f (= 20 kHz) as the optimum ultrasonic frequency fb, and controls the drive circuit 3 so as to oscillate the ultrasonic wave SW having the optimum ultrasonic frequency fb.

  Thus, λ / 2 = 37.m between the bottom inner wall surface 4b of the fuel container 4 and the liquid level Fs of the fuel F due to the traveling wave of the ultrasonic wave SW having the optimum ultrasonic frequency fb and the reflected wave from the liquid level Fs. A standing wave of 5 mm is generated. For this reason, the positions of the nodes P1 to P5 of the standing wave are fixed, and the pressure amplitude energy is added to the fuel molecules in the nodes P1 to P5 of the fixed positions, so that the fuel is softened. Fuel reforming is performed well.

  Here, it is assumed that the fuel F is used and the liquid level height H is lowered. In this case, since the control means 6 measures the liquid level height H every predetermined time or constantly as described above, the optimum ultrasonic frequency fb1 corresponding to the lowered liquid level height H1 is expressed by the above-described equation. 4 and the drive circuit 3 is controlled so as to oscillate the ultrasonic wave SW having the optimum ultrasonic frequency fb1.

  As a result, a standing wave is generated between the bottom inner wall surface 4b of the fuel container 4 and the liquid level Fs where the fuel F has decreased, so that fuel reforming is efficiently performed at each node of the standing wave.

  As described above, the fuel reformer 1 according to the first embodiment generates a standing wave of the ultrasonic wave SW between the bottom inner wall surface 4b of the fuel container 4 and the liquid level Fs of the fuel F, thereby improving the fuel efficiency. In addition, since the standing wave can be generated according to the change of the liquid level Fs of the fuel F, the efficiency of fuel reforming can be improved. That is, the fuel reforming apparatus 1 according to the first embodiment can perform efficient fuel reforming without being affected by the liquid level height H of the fuel F.

  Further, in this fuel reformer 1, since it is possible to generate such standing waves and perform efficient fuel reforming, it is necessary to arrange a plurality of ultrasonic vibrators in the fuel container 4. In addition, there is no need to install an ultrasonic vibrator having a large vibration surface. For this reason, according to this fuel reformer 1, it is possible to perform fuel reforming while suppressing the power consumption required to drive the ultrasonic vibrator 2.

  Here, in the first embodiment, since the ultrasonic transducer 2 is disposed on the bottom outer wall surface 4a of the fuel container 4, the above-described equation 4 when setting the optimum ultrasonic frequency fb is strictly Therefore, the thickness of the fuel container 4 must be taken into consideration. For this reason, the vibration surface 2a of the ultrasonic vibrator 2 may be exposed inside the fuel container 4 so that the thickness does not need to be taken into consideration. For example, the ultrasonic vibrator 2 is installed so that the vibration surface 2 a and the bottom inner wall surface 4 b of the fuel container 4 are flush with each other. In such a case, the above-described reflected wave detecting means 5 is arranged so as to be flush with the vibration surface 2a of the ultrasonic transducer 2.

  As described above, according to the fuel reforming apparatus 1 of the first embodiment, the efficiency is improved while suppressing the power consumption required for driving the ultrasonic vibrator 2 without being influenced by the liquid level height H of the fuel F. Good fuel reforming can be sufficiently performed.

  Thereby, for example, when the fuel container 4 is used as a fuel tank of an automobile, the fuel (gasoline or light oil) F is sufficiently reformed by the fuel reforming apparatus 1 of the first embodiment. Even if there are a lot of heavy components such as hydrocarbons, they are likely to be atomized after reforming and also easily evaporated. For this reason, by improving the atomization characteristics and evaporation characteristics of such fuel F, the emission performance at the start of the engine when the engine is cold such as at the start of cryogenic temperature is improved (reduction of HC emissions), and further, the smoke And black smoke emissions are also reduced. Further, even if the fuel F does not contain a large amount of such heavy components, the atomization characteristics and evaporation characteristics of the fuel F are also improved, so that the emission performance at the time of engine start and operation is improved (HC Reduction of emissions).

  Although the drive circuit 3 according to the first embodiment is a circuit that can vary the ultrasonic frequency f steplessly, the drive circuit 3 can vary the ultrasonic frequency f only stepwise. In some cases, the ultrasonic frequency f and the integer n may be selected step by step for each predetermined liquid level height H.

  Next, a second embodiment of the fuel reformer according to the present invention will be described with reference to FIGS. Reference numeral 11 in FIG. 2 shows the fuel reformer of the second embodiment.

  First, in the fuel reformer 11, as an ultrasonic oscillation means of the second embodiment, an ultrasonic vibrator 12 installed on a part of the bottom outer wall surface 4a of the fuel container 4, and the ultrasonic vibrator 12 And a drive circuit 13 for driving the.

  Here, in the first embodiment described above, the liquid level height H of the fuel F, which changes every moment, is measured using the reflected wave from the liquid level Fs of the fuel F, and according to the liquid level height H. Then, the optimum ultrasonic frequency fb for generating a standing wave between the bottom inner wall surface 4b of the fuel container 4 and the liquid level Fs of the fuel F is set.

  However, for example, when the fuel container 4 is input with vibrations or vibrations of a fuel tank of an automobile, the liquid level Fs undulates due to the vibrations or the like, and the accurate liquid level height H is measured. Can not do it. Therefore, depending on the use conditions of the fuel container 4, a standing wave cannot be generated by the ultrasonic wave SW having the optimum ultrasonic frequency fb set based on the measured liquid level height H, and efficient fuel reforming is possible. Can not do.

  Therefore, in the fuel reformer 11 of the second embodiment, the ultrasonic reflector 14 is disposed at a position in the fuel container 4 at a predetermined distance L from the vibration surface 12a of the ultrasonic vibrator 12. A standing wave is generated without being affected by a change such as a wave of the liquid surface Fs.

  Here, the ultrasonic reflection plate 14 reflects the ultrasonic wave SW oscillated from the ultrasonic vibrator 12, and is formed of a material capable of reflecting the ultrasonic wave SW such as aluminum. Note that the ultrasonic reflection plate 14 may be formed by depositing, for example, aluminum or the like only on the reflection surface 14a shown in FIG. As shown in FIG. 2, the ultrasonic reflector 14 of the second embodiment is held on the bottom inner wall surface 4 b of the fuel container 4 via the reflector holding member 15 at the interval L described above.

  In the second embodiment, in order to increase the number of standing wave nodes with good reforming efficiency of the fuel F, the above-described interval L, that is, the vibration surface 12a of the ultrasonic transducer 12 and the ultrasonic wave are used. It is preferable that the distance L between the reflecting plate 14 and the reflecting surface 14a is long.

  Thus, by providing the ultrasonic reflection plate 14 at a predetermined position in the fuel container 4, the distance L between the vibration surface 12a of the ultrasonic transducer 12 and the reflection surface 14a of the ultrasonic reflection plate 14 is fixed. be able to. For this reason, in this fuel reformer 11, the drive circuit 13 oscillates the ultrasonic wave SW of the optimum ultrasonic frequency fb fixed to the ultrasonic vibrator 12, and the traveling wave and the ultrasonic wave are oscillated. A standing wave composed of a reflected wave from the reflecting surface 14 a of the reflecting plate 14 can be generated between the vibrating surface 12 a of the ultrasonic transducer 12 and the reflecting surface 14 a of the ultrasonic reflecting plate 14.

  Here, the optimum ultrasonic frequency fb is a frequency that is an integer n times the half wavelength of the ultrasonic wavelength λ between the vibration surface 12 a of the ultrasonic transducer 12 and the reflection surface 14 a of the ultrasonic reflection plate 14. f, and the distance L between them can be obtained and set by the following formula 5 in which the liquid level height H of the formula 4 is replaced. As the integer n in Equation 5, for example, it is preferable to use a value with the highest reforming efficiency obtained by experiment or simulation.

    f = a / λ = (a · n) / 2L (5)

  According to the fuel reforming apparatus 11 of the second embodiment, even when the liquid level Fs of the fuel F changes such as undulations or the liquid level Fs of the fuel F decreases, a certain optimum is achieved. A standing wave can be generated between the vibration surface 12 a of the ultrasonic transducer 12 and the reflection surface 14 a of the ultrasonic reflector 14 by the ultrasonic wave SW having the ultrasonic frequency fb. For this reason, the positions of the nodes P1 to P5 of the standing wave can always be made constant regardless of the change in the liquid level Fs of the fuel F, and the fuel molecules are changed to the fuel molecules in the nodes P1 to P5 of the fixed position. Since the pressure amplitude energy is added and the softening of the fuel proceeds, efficient fuel reforming can be performed without being affected by the use conditions of the fuel container 4. That is, the fuel reforming apparatus 11 can perform efficient fuel reforming without being affected by changes in the liquid level height H of the fuel F, the waviness of the liquid level Fs, and the like.

  In the second embodiment, the ultrasonic reflector 14 is used to reflect the ultrasonic wave SW. Here, the ultrasonic reflector 14 has a higher acoustic impedance than the case where it is reflected by the liquid surface Fs of the fuel F as in the first embodiment, and the reflection efficiency of the ultrasonic wave SW can be improved. For this reason, since the pressure amplitude energy in each of the nodes P1 to P5 of the standing wave is increased as compared with the first embodiment, the reforming efficiency can be further improved.

  Furthermore, in the second embodiment, since the optimum ultrasonic frequency fb can be fixed, the ultrasonic frequency variable means including the reflected wave detection means 5 and the control means 6 used in the first embodiment is not necessary. Thus, it is possible to construct the fuel reformer 11 with a simple configuration and good reforming efficiency.

  Furthermore, since the standing wave is generated in the second embodiment as in the first embodiment, the fuel F can be used without using a plurality of ultrasonic vibrators or ultrasonic vibrators having a large vibration surface. The reforming efficiency can be improved, and the power consumption required for driving the ultrasonic transducer 12 can be suppressed.

  Here, even in the second embodiment, as illustrated in the first embodiment, the vibration surface 12a of the ultrasonic vibrator 12 is arranged inside the fuel container 4 so that the thickness of the fuel container 4 need not be taken into consideration. May be exposed.

  In the second embodiment, the vibration surface 12a of the ultrasonic transducer 12 and the reflection surface 14a of the ultrasonic reflector 14 need only be parallel to each other, and the vibration surface 12a is not necessarily in the fuel container 4. It is not necessary to be parallel to the liquid level Fs of the fuel F.

  By the way, the fuel reformer 11 of the second embodiment may be configured as shown in FIG. In the fuel reformer 11 shown in FIG. 3, the ultrasonic reflector 14 is suspended from the ceiling surface 4c of the fuel container 4 via the reflector holding member 15, and this also provides the same effects as described above. Can be played.

  As described above, according to the fuel reforming apparatus 11 of the second embodiment, the efficiency is improved while suppressing the power consumption required to drive the ultrasonic vibrator 12 without being affected by the liquid level height H of the fuel F. Good fuel reforming can be sufficiently performed.

  For this reason, when the fuel container 4 is used as a fuel tank of an automobile as exemplified in the first embodiment described above, effects such as improvement in emission performance by sufficient fuel reforming can be achieved.

  Next, a third embodiment of the fuel reformer according to the present invention will be described with reference to FIG. Reference numeral 21 in FIG. 4 indicates the fuel reformer of the third embodiment.

  First, in this fuel reformer 21, as an ultrasonic oscillation means of the third embodiment, an ultrasonic vibrator 22 installed on a part of the bottom outer wall surface 4a of the fuel container 4, and this ultrasonic vibrator 22 And a drive circuit 23 for driving the.

  Here, in Example 2 described above, in order to increase the number of nodes of the standing wave excellent in the reforming efficiency of the fuel F, the vibration surface 12a of the ultrasonic transducer 12 and the reflection surface of the ultrasonic reflection plate 14 are increased. The distance L between 14a is long.

  However, if the distance L is made long in this way, the liquid level Fs of the fuel F drops below the reflecting surface 14a of the ultrasonic reflecting plate 14 as the fuel F is used, and the standing wave The improvement effect of the reforming efficiency due to this cannot always be obtained.

  Therefore, in the fuel reformer 21 of the third embodiment, the ultrasonic reflector 24 is disposed so that the reflecting surface 24a is located at the lowermost end of the liquid level Fs of the fuel F in the fuel container 4 or below the lower end.

  Here, the lowermost end of the liquid level Fs of the fuel F is a position where the liquid level Fs does not decrease any more, for example, a position where the fuel pump 26 shown in FIG. . When the suction limit of the fuel F by the fuel pump 26 is regulated by, for example, a rib 27 standing on the bottom inner wall surface 4 b of the fuel container 4, the ultrasonic reflector 24 is disposed with reference to the rib 27. May be.

  The ultrasonic reflector 24 of the third embodiment is held on the bottom inner wall surface 4b of the fuel container 4 via a reflector holding member 25 as shown in FIG. The ultrasonic reflector 24 may be suspended from the ceiling surface 4c of the fuel container 4 by the reflector holding member 25, as in the fuel reformer 11 shown in FIG.

  As described above, the position of the ultrasonic reflector 24 in the fuel container 4 is lowered, and the distance L between the vibration surface 22 a of the ultrasonic transducer 22 and the reflection surface 24 a of the ultrasonic reflector 24 is shortened. In addition, the optimum ultrasonic frequency fb of the ultrasonic wave SW oscillated by the ultrasonic transducer 22 is set to a constant value using Expression 5 as in the second embodiment.

  On the other hand, when the distance L between the vibration surface 22a of the ultrasonic transducer 22 and the reflection surface 24a of the ultrasonic reflection plate 24 is shortened, the number of nodes of the standing wave therebetween decreases, and the fuel F is improved. Quality efficiency will decrease. Therefore, in order to eliminate such inconvenience and improve the reforming efficiency of the fuel F, the optimum ultrasonic frequency fb is set to a value higher than that of the second embodiment, for example.

  As a result, the fuel reforming device 21 of the third embodiment not only has the same effect as the fuel reforming device 11 of the second embodiment described above, but also in a situation where the fuel F is used (for example, an internal combustion engine (illustrated Since the standing wave can always be generated between the vibration surface 22a of the ultrasonic transducer 22 and the reflection surface 24a of the ultrasonic reflector 24 during the operation of (substantially)), the liquid level height H of the fuel F It is possible to always perform efficient and sufficient fuel reforming without being affected by the above.

  Here, even in the third embodiment, the vibration surface 22a of the ultrasonic vibrator 22 is arranged inside the fuel container 4 as illustrated in the first embodiment so that the thickness of the fuel container 4 need not be taken into consideration. May be exposed.

  Also in the third embodiment, similarly to the second embodiment, the vibration surface 22a of the ultrasonic transducer 22 and the reflection surface 24a of the ultrasonic reflector 24 need only be in parallel, and the vibration is not necessarily required. The surface 22a does not need to be parallel to the liquid level Fs of the fuel F in the fuel container 4.

  As described above, according to the fuel reforming device 21 of the third embodiment, the efficiency is improved while suppressing the power consumption required to drive the ultrasonic vibrator 22 without being affected by the liquid level height H of the fuel F. Good fuel reforming can be sufficiently performed.

  For this reason, when the fuel container 4 is used as a fuel tank of an automobile as exemplified in the first embodiment described above, effects such as improvement in emission performance by sufficient fuel reforming can be achieved.

  Next, a fourth embodiment of the fuel reformer according to the present invention will be described with reference to FIGS. Reference numeral 31 in FIG. 5 indicates the fuel reformer of the fourth embodiment.

  First, in the fuel reformer 31, as an ultrasonic oscillation means of the fourth embodiment, an ultrasonic vibrator 32 installed on a part of the bottom outer wall surface 4a of the fuel container 4, and the ultrasonic vibrator 32 And a drive circuit 33 for driving the.

  Here, when the distance L between the vibration surface 12a of the ultrasonic vibrator 12 and the reflection surface 14a of the ultrasonic reflector 14 is made longer as in the fuel reformer 11 of the second embodiment described above, the fuel F As the liquid level Fs decreases, the improvement effect of the reforming efficiency due to the standing wave cannot always be obtained. On the other hand, in the above-described fuel reforming apparatus 21 of the third embodiment, the ultrasonic reflector 24 is disposed so that the reflecting surface 24a is positioned at the lowermost end of the liquid surface Fs of the fuel F or below the lower end of the liquid surface Fs. The reduction in the reforming efficiency associated with this is eliminated by increasing the optimum ultrasonic frequency fb of the ultrasonic wave SW.

  However, in the fuel reforming apparatus 21 of the third embodiment, no matter how the optimum ultrasonic frequency fb of the ultrasonic wave SW is increased, the reduction in reforming efficiency accompanying the decrease in the number of standing wave nodes is completely eliminated. It is difficult to compensate for this, and particularly when the amount of the fuel F in the fuel container 4 is large, the fuel reforming is performed only at a very small portion. Therefore, in such a situation, the fuel reforming apparatus 11 of the second embodiment is improved. Quality efficiency will decrease.

  Therefore, in the fuel reformer 31 of the fourth embodiment, the ultrasonic reflector 34 is moved in accordance with the liquid level height H of the fuel F, so that the uppermost end of the liquid level Fs of the fuel F in the fuel container 4 ( Fuel reforming by standing waves is always performed from the full tank state) to the lowest end.

  Specifically, in the fourth embodiment, an ultrasonic reflector 34 that can move in the vertical direction according to the liquid level height H of the fuel F is disposed above the ultrasonic transducer 32 in the fuel container 4. Deploy. Here, the four guide members 35 shown in FIG. 6 that hold the ultrasonic reflection plate 34 so that the reflection surface 34a is parallel to the vibration surface 32a of the ultrasonic transducer 32 and guide it in the vertical direction are shown in FIG. The ultrasonic reflecting plate 34 is provided in a floating structure so that the ultrasonic reflecting plate 34 can be moved up and down in accordance with the liquid level height H of the fuel F. In FIG. 5, only two guide members 35 are shown for convenience of illustration.

Here, as shown in FIG. 7, for example, the ultrasonic reflecting plate 34 of the fourth embodiment includes a floating portion 34A made of a polymer material having a hollow 34A ₁ inside, and a reflection provided on the lower surface of the floating portion 34A. A floating structure is formed by the part 34B. In such a case, the reflecting portion 34B may be configured by evaporating aluminum or the like on the lower surface of the floating portion 34A.

  Thereby, even if the liquid level height H of the fuel F changes, the ultrasonic reflection plate 34 moves up and down with at least the reflection surface 34a always in contact with the fuel F according to the change.

  On the other hand, in the fuel reforming apparatus 31 of the fourth embodiment, the ultrasonic reflector 34 moves up and down in accordance with the change in the liquid level height H of the fuel F as described above. And the distance L between the reflection surface 34a of the ultrasonic reflection plate 34 and the liquid level height H also change.

  Therefore, in the fourth embodiment, as shown in FIG. 5, the ultrasonic frequency variable means including the reflected wave detecting means 5 and the control means 6 similar to the first embodiment is provided, and the liquid level height H of the fuel F is provided. Fuel reforming is performed by appropriately setting the optimum ultrasonic frequency fb in accordance with the change in.

  For example, when the fuel F in the fuel container 4 is full, the control means 6 uses the following equation 6 in which the liquid level height H in equation 2 is replaced with the distance L, and the ultrasonic transducer 32 is used. The distance Lmax between the vibration surface 32a and the reflection surface 34a of the ultrasonic reflection plate 34 is obtained.

    L = n · (λ / 2) (6)

  Then, the control means 6 obtains the ultrasonic frequency f by substituting the measured distance Lmax and the predetermined integer n into the above-described equation 5, and obtains a standing wave according to the liquid level height H of the fuel F. The optimum ultrasonic frequency fbmax of the ultrasonic wave SW that can be generated is set, and the drive circuit 33 is controlled to oscillate the ultrasonic wave SW of the optimum ultrasonic frequency fbmax.

  Here, the integer n may be prepared as a predetermined value determined in advance for each fuel container 4 in the same manner as in the first embodiment. For example, the integer n varies depending on the liquid level height H. It may be prepared as a value. In any case, the integer n is preferably a value with the best reforming efficiency obtained by experiment or simulation, for example.

  Thereby, the standing wave composed of the traveling wave of the ultrasonic wave SW having the optimum ultrasonic frequency fbmax and the reflected wave from the reflecting surface 34a of the ultrasonic reflecting plate 34 is reflected on the vibrating surface 32a of the ultrasonic transducer 32 and the ultrasonic wave reflected. Since it occurs between the reflecting surface 34a of the plate 34, pressure amplitude energy is added to the fuel molecules at each node of the standing wave, the softening of the fuel proceeds, and the fuel reforming is performed efficiently.

  On the other hand, when the liquid level height H is decreased by using the fuel F, the control means 6 sets the optimum ultrasonic frequency fb according to the liquid level height H at that time based on the above-described equation 5. Then, the drive circuit 33 is controlled to oscillate the ultrasonic wave SW having the optimum ultrasonic frequency fb.

  As a result, a standing wave is generated between the vibrating surface 32a of the ultrasonic transducer 32 and the reflecting surface 34a of the descending ultrasonic wave reflecting plate 34. Therefore, each of the standing waves P1 to P5 efficiently. Fuel reforming is performed.

  As described above, according to the fuel reforming apparatus 31 of the fourth embodiment, the useful effects of the second embodiment and the third embodiment described above can be obtained, and the liquid level Fs of the fuel F in the fuel container 4 can be obtained. Between the uppermost end and the lowermost end of the fuel, the fuel reforming by the standing wave can always be efficiently performed without being affected by the liquid level height H of the fuel F.

  Here, even in the fourth embodiment, the vibration surface 32a of the ultrasonic transducer 32 is arranged inside the fuel container 4 as illustrated in the first embodiment so that the thickness of the fuel container 4 need not be taken into consideration. May be exposed.

  In the fourth embodiment, it is only necessary that the vibration surface 32a of the ultrasonic transducer 32 and the reflection surface 34a of the ultrasonic reflector 34 are parallel to each other, and the vibration surface 32a is not necessarily in the fuel container 4. It is not necessary to be parallel to the liquid level Fs of the fuel F.

  As described above, according to the fuel reforming apparatus 31 of the fourth embodiment, the efficiency is improved while suppressing the power consumption required to drive the ultrasonic vibrator 32 without being affected by the liquid level height H of the fuel F. Good fuel reforming can be sufficiently performed.

  For this reason, when the fuel container 4 is used as a fuel tank of an automobile as exemplified in the first embodiment described above, effects such as improvement in emission performance by sufficient fuel reforming can be achieved.

  Next, a fifth embodiment of the fuel reformer according to the present invention will be described with reference to FIG. Reference numeral 41 in FIG. 8 shows the fuel reformer of the fifth embodiment.

  First, in the fuel reformer 41, as an ultrasonic oscillating means of the fifth embodiment, an ultrasonic vibrator 42 that oscillates an ultrasonic wave SW, and a drive circuit 43 that drives the ultrasonic vibrator 42, Is provided.

Here, in the fifth embodiment, the ultrasonic transducer 42 is an outer surface (hereinafter referred to as “side outer wall surface”) 4d ₁ of the first side surface 4d of the fuel container 4 as shown in FIG. The inner surface (hereinafter referred to as “side inner wall surface”) 4e ₁ of the second side surface 4e of the fuel container 4 disposed in a part of the fuel container 4 and facing the first side surface 4d is reflected by the ultrasonic wave SW. Use as a surface. Therefore, the ultrasonic transducer 42 is arranged so that the vibration surface 42a and the side inner wall surface 4e ₁ of the second side surface 4e are parallel to each other.

Furthermore, the ultrasonic transducer 42 is provided on the side outer wall surface 4d ₁ of the _first side surface 4d in order to enable fuel reforming even when the liquid level Fs of the fuel F in the fuel container 4 decreases. Arrange on the lower side. However, when there is an obstacle such as the rib 27 shown in FIG. 4 on the path of the ultrasonic wave SW oscillated from the ultrasonic vibrator 42, the ultrasonic wave is at a position where the obstacle can be avoided. The vibrator 42 is disposed.

In addition, when the fuel container 4 of the fifth embodiment is formed of a material that does not easily reflect the ultrasonic wave SW, the ultrasonic wave SW is irradiated on the side inner wall surface 4e ₁ of the second side surface 4e described above. For example, a reflecting member capable of reflecting the ultrasonic wave SW made of aluminum or the like is provided. In the fifth embodiment, it is assumed that the ultrasonic wave SW is reflected by the side inner wall surface 4e ₁ of the second side surface 4e.

Thus, the ultrasonic transducer 42 is installed in the first side surface 4d of the fuel container 4, the side inner wall surface 4e ₁ of the second side surface 4e which is opposite to the first side surface 4d as a reflecting surface of the ultrasonic SW By using it, the path length L of the ultrasonic wave SW can be fixed. For this reason, in the fuel reforming apparatus 41, the drive circuit 43 oscillates the ultrasonic wave SW having the fixed ultrasonic frequency fb fixed to the ultrasonic vibrator 42, and the traveling wave and the second wave. it is possible to generate a standing wave composed of a reflected wave from the side inner wall surface 4e ₁ aspect 4e between the side inner wall surface 4d ₂ of the first side surface 4d and the side inner wall surface 4e ₁ of the second side surface 4e.

Here, the optimum ultrasonic frequency fb is an integer n times the half wavelength of the ultrasonic wavelength λ between the side inner wall surface 4d ₂ of the first side surface 4d and the side inner wall surface 4e ₁ of the second side surface 4e. The frequency f is obtained by Equation 5 described above and can be set. As the integer n in Equation 5, for example, it is preferable to use a value with the highest reforming efficiency obtained by experiment or simulation.

According to the fuel reforming apparatus 41 of the fifth embodiment, the first side surface 4d side is affected by the ultrasonic wave SW having a certain optimum ultrasonic frequency fb without being affected by the liquid level height H of the fuel F. A standing wave can be generated between the inner wall surface 4d ₂ and the side inner wall surface 4e ₁ of the second side surface 4e. For this reason, the position of each node P1 to P13 of the standing wave can always be made constant regardless of the change of the liquid level Fs of the fuel F, and the fuel molecule is changed to the fuel molecule in each node P1 to P13 of the fixed position. Since the pressure amplitude energy is added and the softening of the fuel proceeds, efficient fuel reforming that is not affected by the liquid level height H of the fuel F can be performed.

In the fifth embodiment, since the side inner wall surface 4e ₁ of the second side surface 4e is used as the reflection surface of the ultrasonic wave SW, the ultrasonic reflection plates 14 and 24 of the above-described second to fourth embodiments. , 34, the acoustic impedance is higher than the liquid level Fs of the fuel F as in the first embodiment, and the reflection efficiency of the ultrasonic wave SW can be improved. For this reason, since the pressure amplitude energy in each of the nodes P1 to P13 of the standing wave is increased as compared with the first embodiment, the reforming efficiency can be further improved.

  Further, even in the fifth embodiment, the optimum ultrasonic frequency fb can be fixed as in the second and third embodiments. Therefore, the reflected wave detecting means 5 and the control means used in the first and fourth embodiments. The ultrasonic frequency variable means consisting of 6 is not required, and the fuel reforming apparatus 41 having a high reforming efficiency can be constructed with a simple configuration.

  Furthermore, in the fifth embodiment, since standing waves are generated as in the first to fourth embodiments described above, a plurality of ultrasonic vibrators and ultrasonic vibrators having a large vibration surface are used. Even if it is not used, the reforming efficiency of the fuel F is improved, and the power consumption required for driving the ultrasonic vibrator 42 can be suppressed.

  Further, in the fuel reformer 41 of the fifth embodiment, since the fuel container 4 is generally longer in the entire width than in the entire height, the ultrasonic SW is oscillated in the height direction. The number of each section of the standing wave can be increased more than ˜4. Therefore, in the fifth embodiment, the reforming efficiency can be improved more effectively than the first to fourth embodiments described above.

  Here, even in the fifth embodiment, as illustrated in the first embodiment, the vibration surface 42a of the ultrasonic vibrator 42 is arranged inside the fuel container 4 so that the thickness of the fuel container 4 need not be taken into consideration. May be exposed.

  As described above, according to the fuel reforming apparatus 41 of the fifth embodiment, the efficiency is improved while suppressing the power consumption required for driving the ultrasonic vibrator 42 without being affected by the liquid level height H of the fuel F. Good fuel reforming can be sufficiently performed.

  For this reason, when the fuel container 4 is used as a fuel tank of an automobile as exemplified in the first embodiment described above, effects such as improvement in emission performance by sufficient fuel reforming can be achieved.

  If the obstacle such as the rib 27 described above cannot be avoided from the path of the ultrasonic wave SW, an ultrasonic reflector as in the second to fourth embodiments is provided at a position where the path length L can be maximized in the fuel container 4. It may be provided. At that time, the ultrasonic reflection plate is arranged so that the reflection surface thereof is parallel to the vibration surface 42 a of the ultrasonic transducer 42.

  As described above, the fuel reforming apparatus according to the present invention is useful for reforming the fuel in the fuel container, and is particularly efficient without being affected by the liquid level of the fuel in the fuel container. Suitable for fuel reforming technology.

It is a figure which shows the structure of Example 1 of the fuel reformer which concerns on this invention. It is a figure which shows the structure of Example 2 of the fuel reformer which concerns on this invention. It is a figure which shows the modification of the fuel reforming apparatus of Example 2. It is a figure which shows the structure of Example 3 of the fuel reformer which concerns on this invention. It is a figure which shows the structure of Example 4 of the fuel reformer which concerns on this invention. FIG. 6 is a view showing an ultrasonic wave reflector and a guide member as seen from an arrow A shown in FIG. 5. 6 is a diagram illustrating an example of a configuration of an ultrasonic reflector having a floating structure in Example 4. FIG. It is a figure which shows the structure of Example 5 of the fuel reformer which concerns on this invention.

Explanation of symbols

1, 11, 21, 31, 41 Fuel reformer 2, 12, 22, 32, 42 Ultrasonic vibrator 3, 13, 23, 33, 43 Drive circuit 4 Fuel container 4a Bottom outer wall surface 4d First side surface 4d ₁ Side outer wall surface 4e Second side surface 4e ₁ Side inner wall surface 5 Reflected wave detection means 6 Control means 14, 24, 34 Ultrasonic reflector 35 Guide member F Fuel fb Optimum ultrasonic frequency Fs Liquid level H Liquid level height P1 P13 Section SW Ultrasound

Claims (4)

  Ultrasonic oscillation means for oscillating ultrasonic waves from the bottom surface is disposed on the bottom surface of the fuel container, and the frequency of the ultrasonic waves from the ultrasonic oscillation means is variable according to the liquid level of the fuel in the fuel container. A fuel reformer comprising an ultrasonic frequency variable means for causing the fuel to change.   Ultrasonic wave oscillating means for oscillating ultrasonic waves from the bottom surface is disposed on the bottom surface of the fuel container, and an ultrasonic wave reflecting plate for reflecting ultrasonic waves from the ultrasonic wave oscillating means is provided at a predetermined position in the fuel container. A fuel reformer characterized by that.   A fuel reforming apparatus, wherein an ultrasonic oscillation means for oscillating ultrasonic waves from the side surface is disposed on a side surface of the fuel container.   The fuel reformer according to claim 1, 2 or 3, wherein the ultrasonic oscillating means generates a standing wave in the fuel in the fuel container.

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