JP2002311003A - Adhesion measuring device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure adhesion applied to an object at high precision by correct ly measuring sound pressure strength. SOLUTION: An ultrasonic vibrator 4 generates ultrasonic waves based on a sine wave AC voltage amplified by a high speed amplifier 3. Sound radiation force in a loop direction of sound pressure is applied on particle 22, and force is generated in a direction of a horn 5. An amplifier 63 measures sound pressure strength corresponding to vibration of a probe 61, and result of measurement is supplied to an arithmetic unit 7. The arithmetic unit 7 computes adhesion generated at the particle 22 using the sound pressure strength A from the sound pressure measuring device 6 and other parameters.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive force measuring device and method, and more particularly to an adhesive force measuring device and method for measuring the adhesive force of an object using ultrasonic standing waves.

[0002]

2. Description of the Related Art When the particle size of a particle is on the order of a few μm, the behavior is largely different from that of a macro world which can be usually seen. The reason for this is that the adhesive force naturally generated on these fine particles is orders of magnitude greater than that of gravity. For example, even if toner particles are adhered to a flat plate and the front and the back of the flat plate are reversed, most of the toner particles remain attached to the flat plate without being dropped by gravity. Note that this phenomenon is sufficiently observed even with uncharged toner particles. The adhesive force here is a combined force of various forces such as van der Waalska and liquid bridging force. In the case of charged particles, the adhesive force is a resultant force obtained by further adding a mirror image force.

[0003] Regarding the technical research for evaluating and analyzing such adhesion, various measuring methods have been proposed so far. As a typical example of such a measurement method, a measurement method such as an electric field method or a centrifugal separation method has been proposed as described in, for example, "Particle Handbook (Asakura Shoten)" p210.

However, the conventional adhesive force measuring apparatus using the measuring method cannot simultaneously satisfy three important items of the basic performance. The first item is the reliability of the adhesive force measurement result, that is, “accuracy”. Next, the second item is
It is "simple" such as the time required for measurement and the ease of handling of the measuring device. Generally, the adhesive force of an object greatly changes with time within a few seconds immediately after the adhesion. At this time, if the time required for the measurement takes more than ten minutes, it becomes difficult to evaluate the actual adhesive force. Finally, the third item is “measurement environment” related to the measurement environment. In the following description, it will be described in detail which of the three items the conventional adhesive force measuring device does not satisfy.

[0005] An electric field method, which is one of the representative measurement methods, applies a direct current between two conductive parallel electrode plates in a vacuum to apply electrostatic force to charged particles adhering to the surface of the electrode plate. The adhesive force is calculated from the strength of the electric field at the time of application and separation. In the case of the electric field method, the time for applying the electric field itself is very short, and is less than one minute in total.

However, since the electric field strength that can be applied is limited by the Paschen's law regarding the discharge phenomenon, the upper limit is increased by making the vacuum state. Therefore, since it takes several minutes for the decompression time to make a vacuum state,
"Simplicity" has some problems. Further, since the "measurement environment" is limited to a vacuum, the water adsorbed between the particles or the particles and the electrode plate is removed.
As a result, there is a problem that the liquid bridging force, which greatly affects the adhesion, disappears, and the adhesion state of the measurement target is greatly changed.

[0007] On the other hand, the individual charge amounts of the charged particles to be measured also vary considerably. Therefore, the charge amount distribution of the charged particles is measured by another measuring method, and the average value is used as a substitute index. However, at the time of measuring the adhesive force, it is not possible to obtain information as to where the particles adhere and how much the charge amount. Therefore, this causes the "accuracy" of the measurement result to be somewhat low. Further, the adhesive force of the toner layer formed on the intermediate transfer member or the paper in the transfer process cannot be directly measured.

In a centrifugal separation method, which is another typical measurement method, a flat plate to which particles to be measured are attached is fixed on a drum surface capable of high-speed rotation, and the drum is rotated to separate the particles. The centrifugal force acting in the direction is calculated as the adhesive force. Thus, when the centrifugal force overcomes the adhesive force, the particles are exfoliated. The adhesive force is mrω
₁ ² (where m, r, and ω ₁ are respectively the mass of the particle, the radius of the centrifuge, and the angular velocity).

The centrifugal separation method, unlike the electric field method, has a great advantage in terms of "accuracy" because the above-mentioned formula does not include a charge amount having large variations. Further, it is also possible to directly measure the adhesive force of the toner layer formed on the intermediate transfer member or paper in a transfer process such as electrophotography. In addition, since measurement can be performed in a normal environment, there is no problem in terms of the “measurement environment”.

However, it takes a long time of about 10 to 15 minutes for the drum to reach the set number of revolutions. Further, when measuring the adhesive force distribution by gradually increasing the number of revolutions, it is necessary to confirm the attached state of the particles each time. Therefore, there is a need to repeat the cycle of rotation, adhesion distribution confirmation, rotation, and adhesion distribution confirmation, which requires a much longer measurement time. Thus, "simpleness"
Items are a major problem.

In order to solve the above-mentioned problem, the inventor of the present application has proposed in Japanese Patent Application No. 2000-261487 an apparatus and method for measuring an adhesive force (hereinafter referred to as "prior invention").

A first feature of the prior invention is that an acoustic radiation force is used as a force acting on particles. The acoustic radiation force is, for example, disclosed in Japanese Patent Application Laid-Open Nos. 9-193055 and 10
As described in JP-A-109283, a force generated when a particle floating in a sound field is irradiated with ultrasonic waves having an appropriate sound pressure intensity to cause the particle to be trumped at a node or a belly of the sound pressure. It is. The electric field method and the centrifugal separation method use an electrostatic force and a centrifugal force, respectively.

[0013] A second feature of the prior invention is that the irradiation frequency is changed to change the trumped particles into manipulate.
te). When applying this technique to the adhesion measurement technique, the force acting on the particles must be calculated. However, there is a problem that the general technology changes only the frequency of the radiated sound wave, so that the process fluctuates with time and a process of measuring and analyzing a complicated sound field distribution is required.

Therefore, the prior invention has an ultrasonic oscillator and a reflector so that the sound field does not fluctuate with time and can emit the acoustic radiation force in a simple sound field distribution state. The object was placed on the reflector, and the distance between the oscillation surface of the ultrasonic oscillator and the reflector was set to an integral multiple of a half wavelength of the ultrasonic wave to be irradiated. The prior invention measures the amplitude intensity of the ultrasonic wave acting on the particles, that is, the sound pressure intensity,
The acoustic radiation force is calculated using the sound pressure intensity. here,
In the measurement of sound pressure intensity, a probe part of a sound pressure meter capable of measuring sound pressure intensity has been inserted into a sound field formed between an oscillation surface of an ultrasonic oscillator and a reflector.

However, in the case of such a sound pressure measurement, if the size of the probe portion of the sound pressure gauge becomes a nonnegligible level as compared with the distance between the oscillation surface of the ultrasonic oscillation device and the reflector, the formation of the probe is caused by the presence of the probe. The resulting sound field distribution changes significantly compared to before the insertion. For this reason, erroneous measurement of the sound pressure intensity occurs, and the accuracy of the peeling force calculated based on this value is deteriorated. As a result, there has been a problem that the adhesive force cannot be measured accurately.

The present invention has been proposed in order to solve such a problem, and an adhesive force capable of measuring an adhesive force acting on an object with high accuracy by accurately measuring sound pressure intensity. It is an object to provide a measuring device and a method.

[0017]

First, the force and acoustic radiation force used in the present invention will be described.

As is well known in acoustics, when an object in the air or water is irradiated with ultrasonic waves, a force is applied to the object in one direction. This power is called the radiation forc
e). This force is analytically obtained using a fluid dynamics method when the shape of the object is relatively simple. When the shape of the object is a sphere and the sound wave is a plane traveling wave, the radiation force is given by equation (1).

[0019]

(Equation 1)

Where r is the radius of the sphere, I is the intensity of the incident sound wave, and c ₀ is the speed of sound of the medium. In addition, Y _P is called an acoustic radiation force function, and the elastic properties (density and compressibility) of a sphere and the propagation constant k = 2π / λ (where λ is a wavelength) of a sound wave in a liquid. the product of r,
It is a very complicated function that depends on kr.

Equation (1) is an equation of radiation power for a plane traveling wave. It is difficult to analytically determine the radiation force acting on a sphere for an arbitrary sound field distribution, but it is required for spherical particles with a smaller radius than the sound wavelength. Is given by equation (2).

[0022]

(Equation 2)

The case of a standing wave will be described with reference to a one-dimensional model. FIGS. 1A to 1D show the pressure p of the standing wave sound field, the particle velocity u _x , the time average value of the kinetic energy density <K _E >, and the time average value of the potential energy density < P _E > is schematically shown.

From FIG. 1, in the standing wave sound field, the following equation (3) is obtained.
There is a relationship.

[0025]

(Equation 3)

By substituting equation (3) into equation (2), the radiation power in the standing wave sound field is as shown in equation (4).

[0027]

(Equation 4)

Here, a dynamic potential U is defined as in the following equations (5a) and (5b).

[0029]

(Equation 5)

Looking at equation (3), the compression ratio γ between the particles and the medium is
And a coefficient D + (1-γ) composed of a factor D representing the relationship between the particle and the density of the medium is D + (1-γ)> 0 or D + (1-γ)
It can be seen that the sign of F or U is inverted depending on whether (1-γ) <0. That is, when D + (1-γ)> 0, the radiation forces F and U acting on the particles are as shown in FIG. 1C, and the particles are represented by a node of sound pressure (a circle in the figure). Trapped point). Hereinafter, such behavior of the particles will be referred to as A-type behavior.

On the other hand, when D + (1-γ) <0, FIG.
As shown in (d), the particles are trapped in the loop of sound pressure. Hereinafter, this is referred to as a B-type behavior.

FIG. 2 shows the boundary where D + (1−γ) = 0 with respect to the ratio ρ / ρ ₀ between the density of the particles and the density of the medium and the ratio γ (= β / β ₀ ) of the compression ratio between the particles and the medium. It is shown. FIG. 2 also plots the positions of four types of substances (ecologic tissue, polystyrene, fused silica, and titanium) that have considerably different elastic properties in an aqueous solution for reference (Takeuchi Masao, Journal of the Acoustical Society of Japan, 52, 3, (1996), 2
03-209). In aqueous solutions, many substances exhibit A-type behavior, while air bubbles exhibit B-type behavior.

Here, when toner particles in the atmosphere and most of the solid substance are present on the reflector, the behavior type and the direction of action of the force will be examined. First, regarding the behavior, in the case of toner particles in the atmosphere and most solid substances, the density of the atmosphere, which is a gas, is about three orders of magnitude lower than that of a solid, so that ρ /
Since ρ ₀ is about 10 ³ and γ is almost 0, it is plotted in the extending direction of the black arrow shown in FIG. At this time, it is understood that the behavior of the A type is trapped in the node of the sound pressure.

That is, as shown in FIG. 3, with respect to the direction of the acting force, the particles are trapped in the nodes of the sound pressure, which is the direction in which the particles existing on the reflector are always peeled off.

The radiation force of the one-dimensional standing wave sound field is expressed by the following equation (6), where <E> is the sum of <P _E > and <K _E >, and x is the distance from the reflector. .

[0036]

(Equation 6)

In particular, sound pressure amplitude A [N / m ² ], angular frequency ω
Considering the one-dimensional standing wave sound field generated by the interference between the plane sound waves described above, the sound pressure p is expressed by the following equation (7).

[0038]

(Equation 7)

At this time, the equation (6) becomes the following equation (8).

[0040]

(Equation 8)

By inputting the sound pressure value of the sound field formed by the ultrasonic transducer and the density and sound velocity of the measurement environment into equation (8), it is possible to derive a general radiation force F acting on a certain particle size. it can.
In particular, when the particles are located on the reflection plate, the distance x of the particles from the reflection plate is the radius r of the particles, and is represented by Expression (9).

[0042]

(Equation 9)

The distance between the horn and the reflector where the standing wave is formed is nλ / 2 and (nλ / 2) + (λ / 4) (n
Is an integer of 1 or more).

Further, according to the present invention, the physical phenomenon that the reflection plate always becomes the antinode of the sound pressure, and A
Paying attention to the behavior of the type, placing a small object on which it is desired to evaluate and analyze the adhesive force on the reflector, and irradiating ultrasonic waves with a known sound pressure intensity to the adhesive force in the atmosphere with the reflector Can be measured.

Therefore, the adhesive force measuring device according to the present invention
Reflecting means on which particles are arranged and reflect ultrasonic waves,
Ultrasonic wave generating means for generating ultrasonic waves so that a standing wave is generated between the reflecting means, sound pressure measuring means for measuring the sound pressure of the ultrasonic wave on the reflecting means, and the sound pressure measuring means Calculating means for calculating a force generated in the particles as an adhesive force using the measured sound pressure.

Further, the method for measuring the adhesive force according to the present invention comprises: an ultrasonic wave generating step of generating an ultrasonic wave so that a standing wave is generated between the particles and the reflecting means for reflecting the ultrasonic wave; A sound pressure measuring step of measuring a sound pressure of an ultrasonic wave on the reflecting means, and a calculating step of calculating a force generated in the particles as an adhesive force using the sound pressure measured in the sound pressure measuring step. ing.

The ultrasonic wave generating means generates an ultrasonic wave so that a standing wave is formed between the ultrasonic wave generating means and the reflecting means. In order to form a standing wave, it is preferable that the distance between the ultrasonic wave generating means and the reflecting means is nλ / 2 or (nλ / 2) + (λ / 4) (n : An integer of 1 or more). When a standing wave is formed, the position of the reflector becomes a node of sound pressure,
The sound radiation force acts on the antinode of the sound pressure. Therefore,
Acoustic radiation force in the antinode direction of the sound pressure also acts on the spherical particles arranged on the reflecting means.

The sound pressure measuring means measures the sound pressure of the ultrasonic wave applied to the particles, that is, the sound pressure of the ultrasonic wave on the reflecting means. The sound pressure measuring means needs to measure the sound pressure of the ultrasonic waves on the reflecting means without installing a measuring device between the ultrasonic wave generating means and the reflecting means.

The sound pressure measuring means may include, for example, a probe embedded in the reflecting means and an amplifier for measuring the sound pressure of the ultrasonic wave based on the vibration generated in the probe. Also, a table indicating a relationship between the energy input to the ultrasonic wave generating means and the sound pressure of the ultrasonic wave generated by the ultrasonic wave generating means is stored, and when the energy is input to the ultrasonic wave generating means, Referring to the table,
The sound pressure of the ultrasonic wave corresponding to the input energy may be measured.

It is preferable that the calculating means calculates the acoustic reflection power, that is, the adhesion, using the equation (9). Equation (9)
Contains the parameters of the medium and can determine the adhesion of spherical particles even in a vacuum. The particles mentioned here may be, for example, a powder such as a toner. Also,
According to the equation (9), the charge having a variation for each particle is not used as a parameter, so that the adhesive force can be accurately measured.

[0051]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 4 is a configuration diagram of an adhesive force measuring apparatus according to a first embodiment of the present invention.

The adhesive force measuring device includes a high frequency generator 1 for generating a sine wave AC voltage, a sound pressure adjusting device 2 for adjusting the sine wave AC voltage, and a high speed amplifier 3 for amplifying the sine wave AC voltage. An ultrasonic oscillator 4 that oscillates ultrasonic waves based on a sine AC voltage, a horn 5 that mechanically amplifies the vibration of the ultrasonic oscillator 4, and a stainless steel reflector to which particles 22 are attached. A sound pressure measuring device 6 for measuring the sound pressure on the plate 21 and an arithmetic device 7 for calculating the acoustic radiation force (adhesive force) generated on the particles 22 are provided.

The sound pressure adjusting device 2 adjusts the sine wave AC voltage value output from the high frequency generator 1 and the amplification factor of the high speed amplifier 3. Thereby, the number of levels of the acoustic radiation force can be increased without compromising the device configuration. Note that the sound pressure adjusting device 2 may be incorporated in any one of the high frequency generator 1 and the high speed amplifier 3.

The high speed amplifier 3 amplifies the sine wave AC voltage generated by the high frequency generator 1 or adjusted by the sound pressure adjusting device 2 and supplies the amplified voltage to the ultrasonic vibrator 4.

The ultrasonic transducer 4 is arranged at a position facing the particles 22 arranged on the reflection plate 21. As the ultrasonic vibrator 4, a bolted Langevin type vibrator (BLT) is used. The resonance frequency of the ultrasonic vibrator 4 is around 19.84 kHz.

The horn 5 is composed of, for example, an exponential horn, and is connected to the ultrasonic vibrator 4. The horn 5 mechanically amplifies the vibration of the ultrasonic vibrator 4,
The sound pressure of the ultrasonic wave generated by the ultrasonic vibrator 4 is amplified. The ultrasonic transducer 4 and the horn 5 may be of any type other than those described above, and any type may be used.

The distance between the tip 5a of the horn 5 and the reflecting plate 21 is set to a distance corresponding to a half wavelength of the ultrasonic wavelength.
At room temperature, this distance is 8.7 mm. Note that this distance may satisfy nλ / 2 or (nλ / 2) + (λ / 4) (n is an integer of 1 or more). Tip 5a of horn 5
When the ultrasonic waves are generated, they generate the same phase vibration (piston vibration) in the direction of the arrow shown in FIG.

The sound pressure measuring device 6 includes a probe 61 that vibrates according to the sound pressure intensity of the ultrasonic wave, a preamplifier 62 that performs preprocessing, and an amplifier 63 that measures the sound pressure.

The diameter of the probe 61 is 1/4 inch (≒ 6 m).
m). As shown in FIG. 5, the tip of one end of the probe 61 is covered with a shield 64 to prevent dust. The shape of the shield 64 is not particularly limited. For example, as shown in FIG. 6A, holes 29 are formed radially from the central axis in the radial direction,
For example, as shown in FIG. 6B, holes 29 may be arranged at equal intervals.

In the probe 61, the shield 64 is
1 is buried in the reflection plate 21 so as to be located on the flat surface. The position where the probe 61 is embedded in the reflection plate 21 is not particularly limited, but the sound field distribution is slightly disturbed as the distance from the horn center axis increases. Therefore, the probe 61
Is preferably closer to the central axis of the horn 5, as shown in FIG. For the same reason, the reflection plate 2
The position of the particles 22 attached to the horn 1 is also preferably closer to the central axis of the horn 5.

The connection between the probe 61 and the preamplifier 62
It can be changed according to the free space below the reflector 21. FIG. 8 shows the probe 6 buried in the reflection plate 21.
1 is a sectional view of FIG. When the free space below the reflector 21 is narrow, the probe 61 and the preamplifier 62 may be connected using an angle changer 65 as shown in FIG. Thereby, the signal cable 66 can be shortened, and unexpected contact with peripheral members can be prevented. on the other hand,
When the free space below the reflection plate 21 is large, the probe 61 and the preamplifier 62 may be directly connected as shown in FIG.

The amplifier 63 passes through a preamplifier 62,
It is connected to the probe 61, converts the vibration of air transmitted to the probe 61 into an electric signal, measures the sound pressure intensity, and supplies the measured value to the arithmetic unit 7. The sound pressure measuring device 6 is generally of two types, a condenser microphone and an electrostrictive or piezoelectric microphone. In the present invention, either type may be used.

The arithmetic unit 7 stores the density ρ of the particles 22 to be measured, the density ρ _{0 of} the medium, the propagation constant k (= 2π / λ), etc., and sends the sound pressure amplitude (sound pressure) Strength) A
Is input, the following equation (10) is calculated, and the adhesive force F is calculated.
Ask for.

[0065]

(Equation 10)

R: radius of particle 22 c ₀ : sound velocity of medium D = 3 (ρ−ρ ₀ ) / (2ρ + ρ ₀ ) γ: compression ratio of particle to medium (= β / β ₀ ) The adhesive force measuring device performs a predetermined process according to the following procedure.

The ultrasonic transducer 4 is a high-speed amplifier 3
An ultrasonic wave is generated based on the sine wave AC voltage amplified by. As a result, a standing wave is formed between the horn 5 and the reflector 21, and at this time, the reflector 21 to which the particles 22 are adhered is formed.
Is the node of sound pressure. Therefore, the particles 22 include
A sound radiation force acts on the antinode of the sound pressure, and a force is generated in the horn 5 direction.

The amplifier 63 of the sound pressure measuring device 6 measures the sound pressure intensity according to the vibration of the probe 61, and supplies the measurement result to the arithmetic device 7.

Using the sound pressure intensity A from the sound pressure measuring device 6 and other parameters, the calculating device 7 calculates the acoustic radiation force generated in the particles 22 based on the equation (10). However, the sound pressure value A measured under the condition that a standing wave is formed is twice as large as the sound pressure value of the traveling wave without the reflector. Therefore, when substituting into equation (10),
It is necessary to convert the measured value of the sound pressure measuring device 6 to 1/2.

Next, the intensity level of the ultrasonic sound pressure applied to the particles 22 is changed in five stages by adjusting the high frequency generator 1, the sound pressure adjuster 2 and the high speed amplifier 3.

FIG. 9 is a diagram schematically showing the relationship between sound pressure and acoustic radiation force. As shown in FIG.
The relationship is proportional to the square of the sound pressure. FIG. 10 is a diagram illustrating a state in which the particles 22 on the reflecting plate 21 are gradually separated as the acoustic radiation force increases. Note that FIG.
(A) is a case where no acoustic radiation force acts on the particles 22, and the acoustic radiation force gradually increases as shown in FIGS. In addition, FIG.
(F) respectively corresponds to (b) to (f) in FIG.

According to FIGS. 9 and 10, as the sound pressure intensity of the ultrasonic waves increases, the magnitude of the acoustic radiation force acting on the φ10 μm particles also increases. With the start of the ultrasonic irradiation, the particles 22 having a small adhesive force are gradually separated from each other, and the particles 22 having a large adhesive force are separated when a high acoustic radiation force acts.

Here, in order to record the state in which the particles 22 adhered to the reflecting plate 21 are peeled off, an adhesive force measuring device having the following configuration may be used.

For example, as shown in FIG. 11, in addition to the configuration shown in FIG. 4, the adhesive force measuring device includes a microscope 8 for imaging spherical particles 22 disposed on a reflecting plate 21 and an image captured by the microscope 8. And an image recording unit 9 for recording the obtained image. The reflection plate 21 is made of a transparent member such as a glass material. In FIG. 11, the specific configuration of the sound pressure measuring device 6 is omitted.
The same applies to FIGS. 12 and 13 described later.

The microscope 8 is provided at a position facing the horn 5 with the reflector 21 interposed therebetween, and picks up an image of the particles 22 arranged on the reflector 21 from behind the reflector 21. The microscope 8 captures an image in synchronization with a change in sound pressure of an ultrasonic wave generated by the ultrasonic transducer 4, and supplies image data to an image recording device 9. The image recording device 9
The image data from the microscope 8 is recorded on a recording medium (not shown). As a result, the adhesive force measurement device
2 and the state where the particles 22 peel off from the reflection plate 21 can be recorded.

However, when the reflecting plate 21 is made of a steel plate or paper, the state in which the particles 22 are separated cannot be recorded even by using the adhesion measuring device shown in FIG.
Therefore, an adhesive force measuring device as shown in FIG. 12 may be used.

The above-mentioned adhesive force measuring apparatus includes a rail 10 capable of moving the reflecting plate 21 in the horizontal direction in addition to the configuration shown in FIG. In this case, the microscope 8 is arranged not on the back side of the reflector 21 but on the front side of the reflector 21, that is, on the side of the ultrasonic transducer 4 or the horn 5.

In such a configuration, the ultrasonic vibrator 4
When the horn 5 irradiates the ultrasonic waves to the spherical particles 22, the rail 10 moves until the spherical particles 22 on the reflecting plate 21 are located directly below the microscope 8. The microscope 8 captures an image of the state of the spherical particles 22 on the reflection plate 21, and thereafter, the rail 10 returns to the ultrasonic irradiation position. Then, the ultrasonic vibrator 4 and the horn 5 irradiate the spherical particles 22 with ultrasonic waves whose sound pressure has been raised by one stage, and repeat the above-described process.

Thus, the adhesive force measuring apparatus can record the state of each particle 22 disposed on the reflection plate 21 even if the reflection plate 21 is made of an opaque material such as a copper plate.

When the reflection plate 21 is made of a steel plate or paper, an adhesion measuring device as shown in FIG. 13 can be used. The above-mentioned adhesive force measuring device includes a revolver 12 that can be rotated in a horizontal direction about a rotation shaft 11 in addition to the configuration shown in FIG. 11.

The revolver 12 is, as shown in FIG.
Horn 5 arranged to emit ultrasonic waves in the vertical direction
And a microscope 8 arranged to capture images in the vertical direction. As shown in FIG. 14, the horn 5 and the microscope 8 are opposed to each other with the rotating shaft 11 interposed therebetween, and are arranged at the same distance from the rotating shaft 11.

In the adhesive force measuring device having such a configuration, first, the ultrasonic vibrator 4 and the horn 5 irradiate the spherical particles 22 with ultrasonic waves. Next, the revolver 12 is rotated by 180 degrees so that the spherical particles 22 on the reflection plate 21 are located directly below the microscope 8. The microscope 8 is the reflector 2
An image of the state of the spherical particles 22 on 1 is taken, and thereafter, the revolver 12 rotates again by 180 degrees and returns to the original position. And
The ultrasonic vibrator 4 and the horn 5 irradiate the spherical particles 22 with ultrasonic waves having a sound pressure raised by one step, and repeat the above-described process.

Thus, the adhesive force measuring device can determine the adhesive force distribution of each spherical particle 22 disposed on the reflector 21 even when the reflector 21 is made of an opaque material. .

[Second Embodiment] Next, a second embodiment of the present invention will be described. The same portions as those in the first embodiment are denoted by the same reference numerals, and detailed description of the same portions will be omitted.

FIG. 15 is a diagram showing a configuration of an adhesive force measuring device according to the second embodiment of the present invention.

The adhesive force measuring device includes a high frequency generator 1 for generating a sine wave AC voltage, a sound pressure adjusting device 2 for adjusting the sine wave AC voltage, and a high speed amplifier 3 for amplifying the sine wave AC voltage. An ultrasonic oscillator 4 that oscillates based on a sine AC voltage to oscillate ultrasonic waves, a horn 5 that mechanically amplifies the vibration of the ultrasonic oscillator 4, and a reflection plate 21 on which particles 22 adhere. A sound pressure measuring device 6 for measuring sound pressure,
An arithmetic unit 7 for calculating the acoustic radiation force (adhesive force) generated on the particles 22 and a sound pressure arithmetic unit 16 for calculating the sound pressure generated on the reflecting surface of the reflecting plate 21 are provided.

The sound pressure calculating device 16 is connected to the sound pressure adjusting device 2. The sound pressure adjusting device 2 is connected to the high frequency generator 1 and the high speed amplifier 3 and controls the input energy to the ultrasonic vibrator 4.

The sound pressure calculation device 16 stores a measurement data table of the input energy to the ultrasonic vibrator 4 and the sound pressure intensity. The sound pressure calculation device 16 measures the input energy of the ultrasonic transducer 4 and checks the measurement data table to calculate a sound pressure intensity corresponding to the measured input energy. In addition, as the input energy, for example, at least one of power, current, and voltage input to the ultrasonic transducer 4 is preferable.

FIG. 16 is a diagram showing an example of measured data of the current value (normalized current) input to the ultrasonic transducer 4 and the sound pressure intensity (normalized sound pressure) of the ultrasonic wave applied to the particles 22. . According to the figure, since the input current value and the sound pressure intensity have high correlation and have linearity, it is possible to derive a regression equation for obtaining the sound pressure intensity from the input current value. In this case, there is no problem in calculating the irradiation sound pressure intensity from the input current value using the regression equation without performing the collation work with the measurement data table. As a result, the arithmetic unit 7 can calculate an accurate adhesive force using the sound pressure intensity obtained by the sound pressure arithmetic unit 16.

When the adhesion of the particles 22 is measured in the atmosphere, the conventional electric field method cannot be realized due to the necessity of disposing the sample under a vacuum condition. Even in this case, the adhesion of the particles 22 can be measured.

The adhesion measuring device may further include a display device (not shown) for displaying the magnitude of the adhesion of each particle 22 in addition to the configuration shown in FIG.

FIG. 17 is a diagram showing an example of an adhesive force distribution displayed on the display device. The display device displays the adhesive force distribution based on the calculation result of the calculation device 7. The vertical and horizontal axes indicate the position of the spherical particle 22 on the reflecting plate 21 in a two-dimensional plane, that is, the coordinate position. The size of the data point corresponds to the magnitude of the adhesive force of the spherical particle 22 arranged at that position. Therefore, the display device displays each particle 22.
It is possible to display an adhesive force distribution in which the radius of the data point increases with an increase in the adhesive force so that the adhesive force can be easily visually recognized.

In the conventional centrifugal method, it takes about 10 to 15 minutes to reach the set rotation speed.
"Ease of use" was a major problem. On the other hand, the adhesive force measuring device can measure the adhesive force in one second or less in the case of one level, and about one minute in the case of five levels. Therefore, the measurement can be performed in an extremely short time as compared with the conventional measurement method.

In the first and second embodiments, a stainless steel plate is used for the reflection plate 21, but it is not necessary to use a stainless steel plate. If there is no problem. Whether or not the reflector 21 can be used is the highest priority as to whether or not it can reflect ultrasonic waves, which largely depends on the product of sound speed and density (acoustic impedance) of the atmosphere and the material of the reflector. Most of the solid substance has a value that is about three orders of magnitude larger than the acoustic impedance of the atmosphere, so that it can be a reflector. Therefore, the material of the reflection plate 21 may be a solid, and the specific material is not limited.

[Third Embodiment] Next, a third embodiment of the present invention will be described. The same portions as those in the above-described embodiment are denoted by the same reference numerals, and detailed description of the same portions will be omitted.

FIG. 18 is a configuration diagram of an adhesive force measuring device according to the third embodiment. The third embodiment is a composite type of the first and second embodiments. That is, the adhesive force measuring device includes a high frequency generator 1 for generating a sine wave AC voltage, and a sound pressure adjusting device 2 for adjusting the sine wave AC voltage.
And high-speed amplifier 3 for amplifying sine wave AC voltage
An ultrasonic oscillator 4 that oscillates ultrasonic waves based on a sine AC voltage, a horn 5 that mechanically amplifies the vibration of the ultrasonic oscillator 4, and a reflector 21 on which particles 22 adhere. Sound pressure measuring device 6 for measuring the sound pressure of the sound, computing device 7 for calculating the acoustic radiation force (adhesive force) generated on the particles 22, and sound pressure for calculating the sound pressure generated on the reflecting surface of the reflecting plate 21 And an arithmetic unit 16.

Here, the sound pressure calculating device 16 always generates the latest measurement data table based on the sound pressure measured by the sound pressure measuring device 6. Specifically, the sound pressure calculation device 16 measures the energy (for example, voltage) input to the ultrasonic transducer 4 and inputs the sound pressure intensity of the ultrasonic wave measured by the sound measurement device 6, The measured voltage and the corresponding sound pressure intensity are written in the measurement data table. Therefore, the sound pressure calculation device 16 can always store the latest and accurate measurement data table by correcting the change of each data of the measurement data table caused by the change of the measurement environment.

Thus, even if any trouble occurs in the sound pressure measuring device 6, the adhesive force measuring device can measure the adhesive force by using the latest data table stored in the sound pressure calculating device 16. Can continue.

[0099]

As is apparent from the above description, according to the adhesive force measuring apparatus and method according to the present invention, an ultrasonic wave is generated so as to generate a standing wave between the reflecting means and the reflecting means. By measuring the sound pressure of ultrasonic waves and calculating the force generated on the particles as the adhesive force using the measured sound pressure, the sound pressure intensity can be measured without disturbing the sound field, and as a result, high measurement accuracy Can be used to measure the adhesion.

[Brief description of the drawings]

FIG. 1 shows the pressure p of the standing wave sound field, the particle velocity ux, the time average <KE> of the kinetic energy density, the potential
It is the figure which showed the time average value <PE> of energy density typically.

FIG. 2 shows boundaries where D + (1−γ) = 0 with respect to the ratio ρ / ρ ₀ of the density of the particles to the density of the medium and the ratio γ (= β / β ₀ ) of the compressibility of the particles and the medium. FIG.

FIG. 3 is a diagram showing directions of forces acting on particles existing on a reflector.

FIG. 4 is a diagram showing a configuration of an adhesive force measuring device according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a state in which a shield is covered by an opening of a probe.

FIG. 6 is a front view illustrating the shape of a shield.

FIG. 7 is a diagram for explaining a buried position of a probe on a reflection plate.

FIG. 8 is a cross-sectional view of the probe in a state where the probe is buried in a reflector.

FIG. 9 is a diagram schematically showing the relationship between sound pressure and acoustic radiation force.

FIG. 10 is a diagram showing a state in which particles on a reflector are gradually separated as the acoustic radiation force increases.

FIG. 11 is a diagram showing another configuration of the adhesive force measuring device.

FIG. 12 is a diagram showing another configuration of the adhesive force measuring device.

FIG. 13 is a diagram showing another configuration of the adhesive force measuring device.

FIG. 14 is a front view of the revolver.

FIG. 15 is a diagram showing a configuration of an adhesive force measuring device according to a second embodiment of the present invention.

FIG. 16 is a diagram showing an example of measurement data of an input current value and an irradiation sound pressure intensity level.

FIG. 17 is a diagram illustrating an example of an adhesive force distribution displayed on the display device.

FIG. 18 is a diagram illustrating a configuration of an adhesive force measuring device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency generator 2 Sound pressure adjusting device 3 High speed amplifier 4 Ultrasonic transducer 5 Horn 6 Sound pressure measuring device 7 Computing device 16 Sound pressure computing device

Claims (8)

[Claims] 1. A reflecting means on which particles are arranged and reflecting an ultrasonic wave; an ultrasonic wave generating means for generating an ultrasonic wave so as to generate a standing wave between the reflecting means; An adhesive force measuring device comprising: a sound pressure measuring unit that measures a sound pressure of an ultrasonic wave; and a calculating unit that calculates a force generated in the particles as an adhesive force using the sound pressure measured by the sound pressure measuring unit. . 2. The sound pressure measuring means includes a probe buried in the reflecting means, and an amplifier for measuring a sound pressure of the ultrasonic wave based on vibration generated in the probe. The adhesion measuring device according to claim 1. 3. The sound pressure measuring means stores a table showing a relationship between energy input to the ultrasonic wave generating means and a sound pressure of an ultrasonic wave generated by the ultrasonic wave generating means. 2. The adhesive force measuring device according to claim 1, wherein when energy is inputted to the sound wave generating means, the sound pressure of the ultrasonic wave corresponding to the inputted energy is measured with reference to the table. 4. A table which stores a relationship between energy input to said ultrasonic wave generating means and a sound pressure of an ultrasonic wave generated by said ultrasonic wave generating means, and stores a sound pressure by said sound pressure measuring means. The table is updated each time is measured, and the sound for estimating the sound pressure of the ultrasonic wave generated by the ultrasonic wave generating means is referred to when the energy is input to the ultrasonic wave generating means. The adhesive force measuring device according to claim 2, further comprising a pressure estimating unit. 5. An ultrasonic wave generating step of generating an ultrasonic wave so that a standing wave is generated between a particle disposed and a reflecting means for reflecting the ultrasonic wave, and a sound pressure of the ultrasonic wave on the reflecting means. And a calculating step of calculating a force generated in the particles as an adhesive force using the sound pressure measured in the sound pressure measuring step. 6. The method for measuring an adhesive force according to claim 5, wherein in the sound pressure measuring step, the sound pressure of the ultrasonic wave is measured based on a vibration generated in a probe embedded in the reflection unit. . 7. The sound pressure measuring step includes the steps of: referring to a table showing a relationship between energy used in the ultrasonic wave generating step and sound pressure of ultrasonic waves generated in the ultrasonic wave generating step. 6. The method for measuring an adhesive force according to claim 5, wherein when energy is used in the ultrasonic wave generating step, a sound pressure of an ultrasonic wave corresponding to the used energy is measured. 8. A table that stores a relationship between energy input to the ultrasonic wave generation step and sound pressure of an ultrasonic wave generated by the ultrasonic wave generation step, and stores a sound pressure in the sound pressure measurement step. The table is updated each time is measured, and the sound for estimating the sound pressure of the ultrasonic waves generated in the ultrasonic generation step is referred to when the energy is used in the ultrasonic generation step. 7. The method according to claim 6, further comprising a pressure estimation step.