JP6894111B2 - Viscosity / elasticity measuring device and viscosity / elasticity measuring method - Google Patents

Description

The present invention relates to a viscoelasticity / elasticity measuring device for measuring viscoelasticity / elasticity, which is a mechanical property of a substance, and a viscoelasticity / elasticity measuring method.

Conventionally, in order to detect the mechanical properties of a target substance, viscosity (sometimes referred to as viscosity in the following description) and elasticity have been measured (see, for example, Patent Document 1).
Viscoelasticity measurement is used for quality control, performance evaluation, and raw materials in the manufacturing process of pharmaceuticals, foods, paints, inks, cosmetics, chemical products, paper, adhesives, fibers, plastics, beer, detergents, concrete admixtures, silicon, etc. It is an indispensable measurement technology for management and research and development.
In the conventionally known viscosity measurement method, torque for driving is applied to a rotating probe (rotor) in contact with the measurement target sample in a non-contact manner, and the viscosity of the target sample is determined from the rotation speed of the rotating probe. There is an apparatus for non-contact measurement (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

In Patent Document 1, a conductive globules are submerged in a sample as a rotor, a predetermined torque is applied non-contactly, and the viscosity of the sample is measured non-contactly from the rotation speed of the globules.
In Patent Document 2, a disk-shaped rotor is floated on the sample surface using either or both of buoyancy and surface tension, a predetermined torque is applied in a non-contact manner, and the rotation speed of the rotor is used to determine the sample. Viscosity is measured non-contact.
In Patent Document 3, the tip of the center of rotation of the lower part of the rotor is formed in a convex shape, the tip of which is in contact with the inner bottom of the container for accommodating the sample, and the rotation shaft is provided on the upper part of the rotor. , This rotating shaft is held by a rotatable mechanism, and the direction of the rotating shaft is fixed. Then, a predetermined torque is applied to the rotor in a non-contact manner, and the viscosity of the sample is measured in a non-contact manner from the rotation speed of the rotor.

Japanese Unexamined Patent Publication No. 2009-264982 Japanese Unexamined Patent Publication No. 2012-242137 Japanese Unexamined Patent Publication No. 2016-031352

However, in Patent Document 1 described above, the flow velocity of the sample around the globules is not known for non-Newtonian liquids, and the shear rate that gives viscosity cannot be uniquely determined, and measurement of low viscosity such as pure water is performed. I can't get the accuracy.
In Patent Document 2, when measuring the viscosity, it is necessary to accurately measure the distance (floating height) between the rotor and the bottom of the container, but the measurement varies depending on the amount of the sample contained in the container. In order to measure the above distance for each time, a highly accurate measuring instrument is required. In addition, the levitation height fluctuates due to evaporation of the sample, a change in the specific gravity of the sample due to a change in temperature, or a change in the wettability between the rotor and the sample. Therefore, the measurement accuracy of the viscosity of the sample may change depending on the surrounding environment.

In Patent Document 3, the friction between the rotating shaft provided on the upper part of the rotor and the mechanism for holding the rotating shaft reduces the measurement accuracy for a sample having low viscosity such as pure. In order to improve the accuracy, it is necessary to give a high-speed rotation of one rotation or more per second, and it is not possible to improve the accuracy of viscosity measurement in the low shear rate range. In addition, when a sample evaporated in the container condenses between the rotating shaft and the mechanism that holds the rotating shaft, the surface tension of the condensed sample affects the rotation speed of the rotor and reduces the measurement accuracy. May be done.

The present invention has been made in view of such circumstances, and the sample container containing the substance to be detected can be inexpensive and disposable, and the viscosity of the sample substance over a wide range from low viscosity to high viscosity can be obtained. An object of the present invention is to provide a viscosity / elasticity measuring device and a viscosity / elasticity measuring method capable of measuring easily and with high accuracy as compared with the prior art.

In order to solve the above-mentioned problems, the viscosity / elasticity measuring device of the present invention is made of a material having conductivity in part or in whole, and has a rotor having a protruding protrusion at the center of rotation at the lower part thereof and viscosity. The sample container in which the rotor is placed and the rotor is time-varying in a state where the substance to be detected is put in and the protrusion is in contact with the bottom of the inner surface of the rotor in contact with the substance to be detected. A rotation control unit that applies a magnetic field, induces an induced current in the rotor, and applies rotational torque to the rotor by Lorentz interaction between the induced current and the magnetic field applied to the rotor to rotate the rotor. A rotation detection unit that detects the rotation speed of the rotor and a viscous elasticity detection unit that detects the viscosity and elasticity of the substance to be detected in contact with the rotor according to the rotation speed of the rotor. The rotor is rotationally symmetric, the axis of rotational symmetry of the rotor is the axis of rotation, the buoyancy position due to the buoyancy generated corresponding to the portion of the rotor submerged in the detection target substance, and the center of gravity of the rotor. each of the positions is above the rotary shaft, and Ri vertically downward near the center of gravity relative to the center of buoyancy position, the rotor is relative to the upper portion of the circular bottom plate, of the bottom plate in a plan view A column-shaped floating portion is provided so that the outer periphery and the outer periphery of the column overlap, the floating portion has a large buoyancy as compared with the bottom plate, and the buoyancy position is the detection of the rotor. It is characterized in that it occurs corresponding to the floating portion submerged in the target substance.

The viscosity / elasticity measuring device of the present invention is characterized in that the radius of the rotor is determined by the following equation (14) .
The viscosity / elasticity measuring device of the present invention is characterized in that the floating portion has a hollow inside of the cylinder and has a cylindrical shape.

The viscoelasticity / elasticity measuring device of the present invention is characterized in that the distance between the center of gravity position and the buoyancy center position is set to be equal to or greater than the distance having a restoring force for holding the rotation axis in the rotation of the rotor in the vertical direction. And.

The viscosity / elasticity measuring device of the present invention stores a storage unit that stores standard data obtained by previously measuring the relationship between the rotational torque applied to the rotor in a plurality of substances whose viscosity is known and the rotational speed of the rotor. Further, it is characterized in that the viscosity / elasticity of the detection target substance is obtained by comparing the relationship between the rotation torque and the rotation speed of the detection target substance detected by the viscosity detection unit and the standard data.

The viscoelasticity / elasticity measuring device of the present invention is characterized in that a mark is attached to the surface of the rotor, and the rotation detection unit detects the rotation number of the rotor by detecting the rotation of the mark. And.

The viscosity / elasticity measuring device of the present invention detects the number of rotations of the rotor by irradiating the rotor of the rotor with a laser and optically measuring the reflected light or the change in the interference pattern. It is characterized by doing.

The viscoelasticity / elasticity measuring device of the present invention is characterized in that the rotor is formed so as to be thinner in proportion to the distance from the rotation axis in the radial direction of the rotor.

The viscoelasticity / elasticity measuring device of the present invention is characterized in that the rotor bottom plate is formed so as to be thinner in proportion to the distance from the rotation axis in the radial direction of the rotor bottom plate.

In the method for measuring viscosity / elasticity of the present invention, a sample container contains a substance to be detected to be detected for viscosity and elasticity, and a part or the whole is composed of a conductive material, and a protrusion is formed at the center of rotation at the lower portion thereof. The process of arranging the rotor having the protrusions in contact with the substance to be detected in a state where the protrusions are in contact with the bottom of the inner surface of the rotor, and applying a time-varying magnetic field to the rotor to apply the rotor. The process of inducing an induced current in the rotator and applying rotational torque to the rotator to rotate it by the Lorentz interaction between the induced current and the magnetic field applied to the rotator, and the number of rotations of the rotator. The detection process and the viscosity detection process of detecting the viscosity / elasticity of the substance to be detected in contact with the rotor according to the number of rotations are included, the rotor is rotationally symmetric, and the axis of rotational symmetry of the rotor rotates. The buoyancy position due to the buoyancy generated corresponding to the portion of the rotor submerged in the detection target substance and the center of gravity position of the rotor are both on the rotation shaft and the center of gravity position. There Ri vertically downward near to the center of buoyancy position, relative to the top of the rotor is circular bottom plate, the separated portion of the cylindrical shape as the outer periphery of the outer periphery and the bar of the bottom plate overlaps in a plan view It is characterized in that the floating portion has a large buoyancy as compared with the bottom plate, and the floating center position is generated corresponding to the floating portion submerged in the detection target substance of the rotor. To do.

As described above, according to the present invention, the sample container containing the substance to be detected is inexpensive and disposable, and the viscosity of the sample substance over a wide range from low viscosity to high viscosity is compared with the conventional one. Therefore, it is possible to provide a viscosity / elasticity measuring device and a viscosity / elasticity measuring method capable of measuring easily and with high accuracy.

It is a schematic block diagram which shows the structural example of the viscosity / elasticity measuring apparatus by one Embodiment of this invention. It is a figure which shows the structural example of the sample container and the rotor in the viscosity / elasticity measuring apparatus shown in FIG. It is a conceptual diagram which looked at the sample container 2 from the side in order to explain the arrangement of the rotor 1 in the sample 100 housed in a sample container 2. It is a conceptual diagram which looked at the sample container 2 from the side in order to explain the other arrangement of the rotor 1 in the sample 100 housed in a sample container 2. It is a top view which shows the fixed state of the magnet provided for generating a rotating magnetic field in a magnet fixing base 7. It is a figure which shows the relationship between the rotation speed ΩM of a motor 4 and the rotation speed ΩD of a rotor 1 in the corresponding standard sample in a standard sample having a plurality of different viscosity ηs. It is a figure which shows the shear rate dependence of each sample (sample A and sample B) obtained from the relationship diagram shown in FIG. It is a figure which shows the electromagnet which the yoke 10 and the teeth 10a, 10b, 10c and 10d protruding from this yoke 10 are arranged on the reference two-dimensional plane. It is a schematic diagram which shows another structural example of the shape of the rotor bottom plate in the rotor 1. It is a figure which shows the relationship between the rotation speed ΩM (that is, the rotation torque) of a motor 4 and the rotation angle θ where a rotor 1 stops. It is a figure which shows the relationship between elasticity and the ratio of a rotation speed and a rotation angle.

Hereinafter, the viscosity / elasticity measuring device according to the embodiment of the present invention will be described with reference to the drawings. 1 and 2 are schematic configuration diagrams showing a configuration example of a viscosity / elasticity measuring device according to an embodiment of the present invention. FIG. 1 shows the overall configuration of the viscosity / elasticity measuring device. FIG. 2 is a diagram showing a configuration example of a sample container and a rotor in the viscosity / elasticity measuring device shown in FIG.
In FIG. 1, the viscosity / elasticity measuring device according to the present embodiment includes a rotor 1, a sample container 2, a first magnet 3_1, a second magnet 3_2, a third magnet 3_3, a fourth magnet 3_4, a motor 4, and a rotation detection sensor. 5. The sample base 6, the magnet fixing base 7, and the viscosity measuring unit 8 are provided.

As shown in FIG. 2, the rotor 1 is formed by a rotor bottom plate 1A and a floating portion 1B. The rotor bottom plate 1A is made of a disk-shaped member, for example, a metal material, and a part or all (whole) thereof is made of a conductor (for example, a metal material). For example, only a part of the rotor bottom plate 1A uses a conductor such as aluminum, and the other part can be made of a material such as plastic or vinyl. That is, the rotor bottom plate 1A may be created by attaching a commercially available aluminum foil or the like to the upper surface of a plastic disk. Thereby, an inexpensive rotor bottom plate 1A can be easily formed from a commercially available plastic disk and a commercially available alum foil.

The floating portion 1B is a cylindrical (rectangular cylinder) shaped floating body coaxial with the rotor bottom plate 1A, and the outer circumference overlaps with the outer circumference of the rotor bottom plate 1A in a plan view from the upper surface. That is, the cross section perpendicular to the central axis of the floating portion 1B and the rotor bottom plate 1A overlap in a plan view. Further, the floating portion 1B is formed so as to have a large buoyancy as compared with the rotor bottom plate 1A. As a result, the rotor 1 has a shape that is rotationally symmetric with respect to the central axis of the rotor bottom plate 1A (the central axis of the floating portion 1B), and rotates about the central axis. It faces the vertical (vertical) direction with respect to the surface of the bottom plate 1A.
Further, since rotation is detected on either one of the rotor bottom plate 1A and the floating portion 1B (described later), it can be detected on either surface (rotor bottom plate 1A in this embodiment) by an image sensor or the like. A size mark is provided.

The sample container 2 is composed of a sample container main body 21 and a sample container lid 22. Further, the sample container 2 accommodates a detection object (hereinafter, referred to as a sample) to be measured for measuring viscosity (that is, viscosity coefficient) η as a mechanical property. Each of the sample container main body 21 and the sample container lid 22 is made of a material such as glass or plastic. The sample container main body 21 is a cylindrical sample container such as a small petri dish. The inner diameter of the sample container main body 21 may be slightly larger than the diameter of the rotor bottom plate 1A (and the floating portion 1B) of the rotor 1.

The sample container lid 22 is used to completely block the sample 100 from the external environment (outside air, etc.) in order to prevent evaporation of the sample 100 and contamination of foreign substances contained in the sample container main body 21, and is necessary. If you don't have one, you don't have to prepare. In the sample container 2, the rotor 1 is arranged so that the rotor bottom plate 1A and the floating portion 1B are in contact with the sample 100 which is the detection target, that is, a part or the whole is submerged in the detection target. ing. As the sample container 2, both the sample container main body 21 and the sample container lid 22 can use a commercially available petri dish made of glass or plastic. Therefore, as the sample container 2, a disposable commercially available sample container can be used as the sample container, and it can be prepared at low cost.

As described above, in this embodiment, the rotor 1 and the sample container 2 can be inexpensive. Therefore, when the biomaterial or the like becomes the sample 100, the rotor 1 and the sample container 2 can be easily discarded even if a substance that requires special attention for disposal is targeted for measurement.
As a result, similar to post-treatment problems such as incineration and sterilization, it can be done as easily as disposing of other medical devices.

FIG. 3 is a conceptual diagram of the sample container 2 as viewed from the side in order to explain the arrangement of the rotor 1 in the sample 100 housed in the sample container 2. In FIG. 3, the floating portion 1B is arranged on the upper surface of the rotor bottom plate 1A and has a tubular shape having only an outer peripheral surface having an open upper portion, and the inside 200 is a space. Due to the space inside 200, a buoyancy corresponding to the specific gravity of the sample 100 is generated with respect to the rotor 1. For the outer peripheral surface of the floating portion 1B, a plate made of resin or the like having a tubular shape, or a cylinder made of a resin pipe cut perpendicular to the central axis and formed by the outer peripheral wall of the cut pipe is used. be able to. Further, as the floating portion 1B, a cylinder in which the internal space is sealed, a cylinder in which the internal 200 is filled with other members, or a cylinder having no internal space may be used. When a cylinder having no internal space is used as the floating portion 1B, a part or all of the bottom surface of the floating portion 1B may be formed of metal or the like, and the floating portion 1B itself may be used as the rotor 1. Even in this case, it is necessary to satisfy the relationship between the buoyancy center and the center of gravity described below.

The mark 30 is arranged on the upper surface of the side wall of the floating portion 1B. The mark 30 may be arranged at a position readable by the imaging device on the upper surface of the rotor bottom plate 1A. The change in the position of the mark 30 is optically read by a sensor, an image pickup device, or the like, the number of rotations of the rotor 1 is obtained, and the rotation speed of the rotor 1 is calculated. In the present embodiment, the rotor bottom plate 1A is formed of a metal disk.
Further, on the lower surface of the rotor bottom plate 1A, a metal projecting portion 1C that comes into contact with the inner surface bottom portion of the sample container main body 21 is provided. The protrusion 1C is in contact with the bottom surface of the groove 21C provided on the bottom surface of the inner surface of the sample container body 21. The rotor 1 rotates with the protrusion 1C inserted into the groove 21C. Therefore, the distance between the lower surface of the rotor bottom plate 1A and the inner bottom surface of the sample container main body 21 is kept constant with high accuracy, and the shear rate of the rotor bottom plate 1A in the sample 100 can be kept stable. The accuracy of the viscosity measurement of the sample 100 is improved.

In the present embodiment, about 60% of the weight of the rotor 1 is the mass of the members constituting the rotor bottom plate 1A, and the remaining about 40% of the weight of the rotor 1 is the mass of the members constituting the floating portion 1B. is there. When the weight of the rotor 1 is about 1.3 g (grams), the magnitude of gravity applied to the rotor 1 is 1.3 grams. Here, when the volume of the hollow portion inside the rotor 1 is about 0.8 cm ³ and the specific gravity of the sample is 1.0 g / cm ³ , the buoyancy applied to the rotor 1 is 0.8 g at the maximum. is there. Therefore, the rotor 1 does not completely float in the sample 100 housed in the sample container 2, and the portion having a predetermined volume is shown in FIGS. 3 (a) and 3 (b), respectively. It will be in a sunk state.

FIG. 3A shows a state in which the rotor 1 is stable and self-supporting in the sample 100 housed in the sample container 2. In the rotor 1 that is self-supporting in the sample, the floating center 202 is applied to the rotor 1 by the floating portion 1B so that the position of the floating center 202 is farther from the protruding portion 1C as compared with the position of the center of gravity 201. The buoyancy is adjusted. The vector 202B of the buoyancy applied to the buoyancy center 202 (buoyancy based on the specific gravity of the rotor 1 and the specific gravity of the sample) faces the upper direction perpendicular to the liquid surface of the sample 100 and the direction away from the liquid surface. .. On the other hand, the vector 201 due to gravity (mass of the rotor 1) applied to the center of gravity 201 is oriented in the lower direction perpendicular to the liquid surface of the sample 100 and away from the liquid surface. When each of the vector 201B and the vector 202B is on the same straight line 150 perpendicular to the liquid surface of the sample 100, that is, parallel to the straight line 150 on the straight line 150 perpendicular to the liquid surface of the sample 100 passing through the center of gravity 201. In the case of, it is stable and independent with respect to the sample 100. That is, in the present embodiment, since the position of the floating center 202 in the rotor 1 is configured to be farther from the protrusion 1C as compared with the position of the center of gravity 201, the rotation axis of the rotor 1 is set. By holding in the vertical direction, the rotor 1 becomes self-supporting in the sample 100.

FIG. 3B shows a state in which the rotor 1 is tilted by some kind of shaking (some force is applied) in the sample 100 housed in the sample container 2. In FIG. 3B, some force is applied to the rotor 1, and the angle θ is between the direction of the straight line 150 perpendicular to the liquid surface of the sample 100 and the direction of the straight line 160 perpendicular to the upper surface of the rotor bottom plate 1A. It's different. At this time, each of the vector 201B and the vector 202B does not exist on the same straight line 150 perpendicular to the liquid surface of the sample 100. That is, each of the vector 201B and the vector 202B is not on the same straight line 150 perpendicular to the liquid surface of the sample 100. In order to obtain a buoyancy equal to the gravity of the sample 100 equal to the volume of the sample 100 excluded by the portion of the rotor 1 submerged in water, tilt as shown in the figure to the larger volume of the portion submerged in the sample 100. The position of the buoyancy 202 moves. That is, in the present embodiment, since the position of the buoyancy center 202 is configured to be farther from the protrusion 1C than the position of the center of gravity 201, the rotation axis of the rotor 1 is restored in the vertical direction. The rotor 1 itself has the restoring force to make it.

In the above case, the rotational moment (torque) is set to the rotor 1 so that each of the vector 201B and the vector 202B returns to the same straight line 150 perpendicular to the liquid surface of the sample 100 and the rotor 1 becomes stable. It takes. A torque for rotating the rotor 1 with respect to the central axis is applied to this rotational moment, and the torque is similarly applied to the rotor 1 even when the rotor 1 is rotating. As a result, the rotating shaft 11 is located on the same straight line as the straight line 150, the liquid level of the sample 100 and the upper surface of the rotor bottom plate 1A are parallel to each other, and the rotor for obtaining the highly accurate viscosity of the sample 100 is obtained. The rotation speed of 1 can be obtained. Then, as the rotor 1 arranged in the sample 100 housed in the sample container 2 rotates, the sample 100 sandwiched between the rotor bottom plate 12 and the sample 100 has a shear flow having a predetermined shear rate. Is generated, and a viscous torque is generated with respect to the rotation of the rotor 1 due to the shear stress based on this shear flow (described later).

FIG. 4 is a conceptual view of the sample container 2 as viewed from the side in order to explain another arrangement of the rotor 1 in the sample 100 housed in the sample container 2. In FIG. 4, the floating portion 1B is arranged on the upper surface of the rotor bottom plate 1A, and the upper portion has a tubular shape having only an outer peripheral surface sealed by a lid 1D, and the inside 300 is a space. The lid 1D is a disk having a thin resin thickness. Due to the space of the inside 300, a buoyancy corresponding to the specific gravity of the sample 100 is generated with respect to the rotor 1. For the outer peripheral surface of the floating portion 1B, a plate made of resin or the like having a tubular shape, or a cylinder made of a resin pipe cut perpendicular to the central axis and formed by the outer peripheral wall of the cut pipe is used. be able to.

Further, as the floating portion 1B, a cylinder whose inner portion 300 is filled with other members or a cylinder having no internal space may be used. In this case, it is not necessary to provide the lid 1D for the floating portion 1B.
When the viscosity is measured with the rotor 1 completely submerged in the sample 100 as shown in FIG. 4, the sample 100 is in contact with the entire lower surface of the lid 1D and the entire lower surface of the sample container lid 21, that is, , The inside of the sample container 2 is filled with the sample 100. In the sample container 2, the sample 100 is filled in the space sandwiched between the sample container main body 21 and the sample container lid 22. As a result, with the rotation of the rotor 1 arranged in the sample 100 housed in the sample container 2, the sample 100 sandwiched between the rotor bottom plate 12 and the lid 1D and the sample 100 is displaced. Viscous torque is generated with respect to the rotation of the rotor 1 (described later).
At this time, in order to improve the measurement accuracy of the viscosity of the sample 100, the distance between the lower surface of the rotor bottom plate 1A and the inner bottom surface of the sample container body 21 and the upper surface of the lid 1D and the lower surface of the sample container lid 21 are opposed to each other. The same applies to the distance.

In the present embodiment, about 60% of the weight of the rotor 1 is the mass of the members constituting the rotor bottom plate 1A, and the remaining about 40% of the weight of the rotor 1 is the mass of the members constituting the floating portion 1B. is there. When the weight of the rotor 1 is about 1.3 g (grams), the magnitude of gravity applied to the rotor 1 is 1.3 grams. Here, when the volume of the hollow portion inside the rotor 1 is about 0.8 cm ³ and the specific gravity of the sample is 1.0 g / cm ³ , the buoyancy applied to the rotor 1 is 0.8 g at the maximum. is there. Therefore, the rotor 1 does not completely float in the sample 100 housed in the sample container 2, and all of the rotor 1 in the sample 200 as shown in FIGS. 4 (a) and 4 (b). Is completely sunk.

FIG. 4A shows a state in which the rotor 1 is sunk in a stable state in the sample 100 housed in the sample container 2. In the rotor 1 that is self-supporting in the sample, the floating center 202 is applied to the rotor 1 by the floating portion 1B so that the position of the floating center 202 is closer to the position of the protrusion 1C than the position of the center of gravity 201. The buoyancy is adjusted. The vector 202B of the buoyancy applied to the buoyancy center 202 (buoyancy based on the specific gravity of the rotor 1 and the specific gravity of the sample) faces the upper direction perpendicular to the liquid surface of the sample 100 and the direction away from the liquid surface. .. On the other hand, the vector 201 due to gravity (mass of the rotor 1) applied to the center of gravity 201 is oriented in the lower direction perpendicular to the liquid surface of the sample 100 and away from the liquid surface. When each of the vector 201B and the vector 202B is on the same straight line 150 perpendicular to the liquid surface of the sample 100, that is, parallel to the straight line 150 on the straight line 150 perpendicular to the liquid surface of the sample 100 passing through the center of gravity 201. In the case of, it floats in a stable state with respect to the sample 100.

FIG. 4B shows a state in which the rotor 1 is floating in an unstable state in the sample 100 housed in the sample container 2. In FIG. 4B, some force is applied to the rotor 1, and the angle θ is between the direction of the straight line 150 perpendicular to the liquid surface of the sample 100 and the direction of the straight line 160 perpendicular to the upper surface of the rotor bottom plate 1A. It's different. At this time, as in the case of FIG. 3B, each of the vector 201B and the vector 202B does not exist on the same straight line 150 perpendicular to the liquid surface of the sample 100.

That is, a rotational moment (torque) is applied to the rotor 1 so that each of the vector 201B and the vector 202B returns to the same straight line 150 perpendicular to the liquid surface of the sample 100 and the rotor 1 becomes stable. A torque for rotating the rotor 1 with respect to the central axis is applied to this rotational moment, and the torque is similarly applied to the rotor 1 even when the rotor 1 is rotating. As a result, the rotating shaft 11 is located on the same straight line as the straight line 150, the liquid level of the sample 100 and the upper surface of the rotor bottom plate 1A are parallel to each other, and the rotor for obtaining the highly accurate viscosity of the sample 100 is obtained. The rotation speed of 1 can be obtained.

In FIG. 1, a sample container 2 filled with a sample 100 is provided on the upper surface of the sample table 6. At the lower part of the sample table 6, a magnet fixing table 7 to which the motor shaft 4a of the motor 4 is connected is provided in parallel with the sample table 6. By rotating the motor shaft 4a of the motor 4, the magnet fixing base 7 is rotated. A first magnet 3_1 (third magnet 3_3) and a second magnet 3_2 (fourth magnet 3_4) are provided on the upper surface of the magnet fixing base 7.

The magnet fixing base 7 is a flat plate-shaped plate member for fixing a magnet that generates a rotating magnetic field. For example, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 is fixedly provided on the upper surface of the magnet fixing base 7. The magnet fixing base 7 is arranged so as to be parallel to the rotor bottom plate 1A. Each of the first magnet 3_1 and the second magnet 3_3 is provided so that the S pole is in contact with the upper surface side of the magnet fixing base 7 and the N pole is opposed to the rotor bottom plate 1A. Each of the second magnet 3_2 and the fourth magnet 3_4 is provided so that the north pole is in contact with the upper surface side of the magnet fixing base 7 and the south pole is opposed to the rotor bottom plate 1A.

Therefore, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet has a magnetic pole having a polarity different from that of the adjacent magnet facing the lower surface of the sample container 2. Further, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet is a rectangular parallelepiped, and the upper surfaces are arranged in parallel with each other so that the heights of the upper surfaces are the same.

FIG. 5 is a plan view showing a fixed state of a magnet provided for generating a rotating magnetic field in the magnet fixing base 7. FIG. 5A shows the arrangement of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet, respectively. Each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3___ is arranged alternately and symmetrically with respect to the rotation axis of the magnet fixing base 7. On the other hand, FIG. 5B shows the arrangement of the fifth magnet 3_5 and the sixth magnet 3_6, respectively.

In the present embodiment, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet are used, but any number of magnets may be used as long as a rotating magnetic field can be generated. That is, although not shown, a plurality of small magnets (N, N = 2n, n is an integer of n ≧ 1) are magnetized along the rotation direction of the rotor bottom plate 1A of the rotor 1 in the sample container 2. The magnetic poles on the upper surface of the above surface may be arranged so that the north pole and the south pole alternate. Further, the magnet fixing base 7 may be arranged on the upper part of the sample container 2 so as to face the liquid surface of the sample 100 filled in the sample container 2 so that the upper surface of the permanent magnet is a horizontal plane.

Returning to FIG. 1, the sample table 6 is a flat plate-shaped plate member for fixing the sample container 2 filled with the sample 100, and is arranged so that the upper surface is parallel to the upper surface of the magnet fixing table 7.
As a result, the rotor 1 can be used when the rotor bottom plate 1A and each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet rotate in the sample 100 inside the sample container 2. The upper surfaces of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet are parallel to the plane formed.
From the arrangement of the sample base 6, the magnet fixing base 7, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet described above, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and so on. Each of the fourth magnets can generate a magnetic field (which may be a magnetic field component that is perpendicular to the rotor 1) in the sample container 2.

The motor 4 is a drive mechanism that rotates the magnet fixing base 7 in the direction of the motor shaft 4a perpendicular to the surface of the magnet fixing base 7, and fixes the motor shaft 4a so as to be perpendicular to the upper surface of the magnet fixing base 7. Has been done.
Further, in a plan view, the rotation shaft 11 of the rotor 1 is arranged at a position where the rotor bottom plate 1A of the rotor 1 does not contact the inner wall of the sample container 2 and rotates in contact with the sample 100. , The sample container 2 and the motor 4 are arranged.
That is, in a plan view, the sample container 2 and the motor 4 are arranged at positions where the center of the bottom surface of the sample container 2 and the axial direction of the motor shaft 4a of the motor 4 overlap.

Further, when a rotating magnetic field is applied to the rotor bottom plate 1A of the rotor 1 in the sample 100 filled in the sample container 2 and the rotation shaft 11 is rotated as the center of rotation, the magnet fixing base 7 is rotated by the motor 4. Let me. As a result, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet rotates, and a rotating magnetic field is applied to the rotor bottom plate 1A. At this time, the rotating shaft 11 of the rotor 1 may deviate from the center of the bottom surface of the sample container 2 depending on the state in which the rotating magnetic field is applied to the rotor bottom plate 1A.
Here, in a plan view, the area of the bottom portion inside the sample container 2 is made larger than the area of the rotor bottom plate 1A of the rotor 1. As a result, even if the rotation shaft 11 of the rotor 1 deviates from the center of the bottom surface of the sample container 2, it does not come into contact with the inner side wall of the sample container 2. However, since the sample container 2 is made large, the amount of the sample 100 to be filled in the sample container 2 required for the measurement of the viscosity η increases.

Therefore, as shown in each of FIGS. 3 and 4, in the present embodiment, a smooth groove portion (recess) 21C is provided in a part of the inner bottom surface of the sample container main body 21. By providing the groove portion 21C, when the rotor 1 is rotated, the protrusion 1C (the convex portion which is the lower portion of the rotating shaft 11) of the rotor bottom plate 1A of the rotor 1 comes into contact with the groove portion 21C so as to coincide with the center. As such, it is arranged by gravity. The rotor 1 rotates with the protrusion 1C of the rotor bottom plate 1A inserted into the groove 21C. Therefore, the distance between the lower surface of the rotor bottom plate 1A and the inner bottom surface of the sample container main body 21 is kept constant with high accuracy, and the shear rate of the rotor bottom plate 1A in the sample 100 can be kept stable. The accuracy of the viscosity measurement of the sample 100 is improved.

FIG. 6 is a diagram showing the relationship between the rotation speed ΩM of the motor 4 and the rotation speed ΩD of the rotor 1 in the corresponding standard sample in the standard sample having a plurality of different viscosity ηs. In FIG. 6, the horizontal axis shows the rotation speed ΩMD (rotation speed ΩM − rotation speed ΩD) between the rotation speed ΩM and the rotation speed ΩD, and the vertical axis shows the rotation speed ΩD of the rotor 1. The viscosity η of each standard sample used here is different, for example, that is 0.5 (mPa · s) for sample A and 1.0 (mPa · s) for sample B. Then, from FIG. 6, the relationship between the rotation difference ΩMD and the rotation speed ΩD for each standard sample having different viscosity η, that is, the curve showing the correspondence of the slopes ΩD / ΩMD is obtained by the least squares method or the like. This slope ΩMD / ΩD is proportional to the viscosity η of each standard sample.

Returning to FIG. 1, the rotation detection sensor 5 is arranged at a position in the upper part of the sample container 2 as a position where a mark provided at a detectable position of the rotor 1 in the sample 100 of the sample container 2 can be detected. The position of the mark added to the rotor 1 (mark 30 provided on the upper surface of the side wall of each of the floating portions 1B of FIGS. 3 and 4) in rotation is optically detected. That is, the rotation detection sensor 5 emits laser light from the light irradiation unit, incidents the reflected light from the mark 30 of the rotor 1 on the light receiving unit, and outputs a detection electric signal corresponding to the intensity of the incident light.

Further, instead of the rotation detection sensor 5, an image pickup device in which an image sensor such as a lens and a CCD (Charge Coupled Device) is attached to the microscope is provided, and the mark attached to the rotor 1 moves in rotation of the rotor 1. The captured image captured by enlarging the state is output, and the number of rotations (that is, the number of rotations of the mark of the rotor 1 and the mark (provided on the upper surface of the side wall of each of the floating portions 1B in FIGS. When the mark 30) makes one rotation, the number of laps may be detected as 1). Further, in the rotor 1, the mark may be added (arranged) at the detectable position on the upper surface of the rotor bottom plate 1A, and the rotation speed of the rotor 1 may be measured by the imaging device. ..

Further, the inner surface of the rotor bottom plate 1A of the rotor 1, the outer peripheral surface of the side wall of the floating portion 1B, or the protrusion 1C is irradiated with a laser, and changes in reflection and interference patterns due to rotation are optically measured. , The configuration may be such that the number of rotations of the rotor 1 is detected.
Further, a part of the rotor bottom plate 1A or the floating portion 1B of the rotor 1 is replaced with a dielectric material, and the electrode pair in which the rotor bottom plate 1A or the floating portion 1B is sandwiched between the measuring electrodes is replaced with a magnet fixing base 7 as shown in FIG. Place it in a position that does not interfere with the rotation of the capacitor, and configure the capacitor. Then, in the rotation detection sensor 5, a dielectric as a mark for detecting rotation (for example, a mark 30 provided on the upper surface of the side wall of each of the floating portions 1B in FIGS. 3 and 4) is placed between the electrodes. When passing through, the detection electric signal is output. That is, the rotation detection unit 81 detects the capacitance change of the capacitor composed of the electrodes when the dielectric as a mark passes between the electrodes, and detects the number of times of the capacitance change in a predetermined period (for example, 1 second). However, it may be configured to detect the rotation speed of the rotor 110.

Here, by rotating the magnet fixing base 7 with the motor 4, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3___ is rotated, and a rotating magnetic field is used as a magnetic field that fluctuates with time. Is formed in the space on the upper surface of the magnet fixing base 7.
This rotating magnetic field applies torque to the rotor bottom plate 1A of the rotor 1 to rotate the rotor 1 in the sample 100 in the sample container 2 to cause a constant velocity rotational motion. Then, a method of measuring the viscosity η of the sample 100 from the rotation speed of the rotor 1 in the sample 100 will be described below.

The viscosity measuring unit 8 includes a rotation detecting unit 81, a viscosity detecting unit 82, a rotating magnetic field control unit 83, a standard data storage unit 84, and a device control unit 85.
The rotation detection unit 81 detects the rotation of the rotor 1 by the detection electric signal supplied from the rotation detection sensor 5, and sets the number of detections per unit time (for example, 1 second) to the number of rotations per unit time (rpm). : Revolutions per minute), the number of revolutions ΩD is calculated and output. Further, when the rotation detection unit 81 uses the image captured by the image pickup device instead of using the detection electric signal of the rotation detection sensor 5 in detecting the rotation speed of the rotor 1, the image pickup device captures and outputs the image. The mark added to the rotor 1 may be detected from the image by image processing, and the rotation speed ΩD per unit time may be obtained. Further, when the capacitor configuration is used, the rotation detection unit 81 detects the capacitance change of the capacitor composed of the electrode pair by the detection electric signal, and detects the number of times of the capacitance change in a predetermined period (for example, 1 second). However, it may be configured to detect the rotation speed ΩD of the rotor 1.

The viscosity detection unit 82 obtains the slope ΩD / ΩMD (= ΩM−ΩD) in the sample 100, and obtains the reciprocal ΩMD / ΩD of this slope, as in the case of the standard sample described above. At this time, the viscosity detection unit 82 controls the rotating magnetic field control unit 83 (described later) to rotate the motor 4 at a plurality of different rotation speeds ΩM, and sends a control signal to the rotation detection unit every time the rotation speed is changed. Output to 81. Each time a control signal is supplied from the viscosity detection unit 82, the rotation detection unit 81 inputs the rotation speed ΩD of the rotor 1 in the sample 100 placed in the sample container 2 at the rotation speed ΩM from the rotation detection sensor 5. Then, the rotation detection unit 81 outputs the detected rotation speed ΩD to the viscosity detection unit 82 in response to the control signal.

Then, the viscosity detection unit 82 reads out the viscosity η (mPa · s) corresponding to the reciprocal ΩMD / ΩD of the sample 100 from the viscosity detection table stored in the standard data storage unit 84 (described later), and reads this into the sample 100. Is output as the viscosity η (mPa · s) of. Here, when the empirical formula is stored in the standard data storage unit 84, the viscosity detection unit 82 reads the empirical formula from the standard data storage unit 84 and substitutes the reciprocal of the inclination ΩMD / ΩD for this empirical formula. Then, the viscosity η (mPa · s) of the sample 100 may be calculated and obtained.

The rotating magnetic field control unit 83 controls the rotation of the motor 4 so that the motor 4 rotates at a set rotation speed. As a result, the magnet fixing base 7 rotates via the motor shaft 4a, and the magnetic fields generated by each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 rotate and rotate. A rotating magnetic field is generated in which the child 1 is rotated at a constant velocity in the sample 100.

The standard data storage unit 84 stores a viscosity detection table showing the correspondence between the viscosity η (mPa · s) obtained from the relationship diagram of FIG. 6 and the reciprocal ΩMD / ΩD of the slope.
This viscosity detection table is created as follows. As described with reference to FIG. 6, in the viscosity measuring apparatus of the present embodiment, a standard sample whose viscosity is known in advance is placed (filled) in the sample container 2, the rotor 1 is placed in the standard sample, and a plurality of presets are set. When the motor 4 is rotated by the rotation speed ΩM of the above, the rotation speed ΩD of the rotor 1 corresponding to the rotation speed ΩM of each motor 4 is measured by the rotation detection unit 81 described above. The rotation speed ΩD for this standard sample is measured for a standard sample having a plurality of different viscosity ηs (a sample whose viscosity η is known in advance).
Further, instead of the viscosity detection table, an empirical formula showing the correspondence between the viscosity η (mPa · s) and the reciprocal of the slope ΩMD / ΩD may be stored.
The device control unit 85 controls the operation of each unit in the viscosity measuring unit 8.

FIG. 7 is a diagram showing the shear rate dependence of each sample (sample A and sample B) obtained from the relationship diagram shown in FIG. In FIG. 7, the horizontal axis shows the shear rate (1 / s), and the vertical axis shows the viscosity (viscosity, mPa · s) of the sample.
In this figure, it is shown that the viscosity of each sample depends on the shear rate, but the change in viscosity is due to the influence of the inertia of the sample, and the viscosity of the standard sample showing the standard viscosity. It can be corrected using a standard sample.
Pure viscosity (viscosity) is 0.9 (mPa · s) at room temperature. From this, it can be seen that the difference in viscosity can be detected with high accuracy by the present embodiment even for the sample A having a viscosity lower than that of the pure sample A.

Next, a method of applying rotational torque to the rotor bottom plate 1A of the rotor 1 will be described. In FIG. 1, the north pole and the fourth magnet 3___ of the first magnet 3_1 and the south pole of the second magnet 3_2 and the fourth magnet 3___ are perpendicular to a certain reference plane (plane including the rotor bottom plate 1A). A magnetic field is generated. This reference plane is a reference two-dimensional plane composed of the x-axis and the y-axis, and the axial direction of the rotation axis 11 of the rotor bottom plate 1A of the rotor 1 rotating in the two-dimensional plane is the z-axis.
Hereinafter, the z-axis component of the magnetic field at a point (x, y, z) in or near the reference two-dimensional plane is shown as Bz (x, y).

As already described, since the magnetic field is perpendicular to the reference two-dimensional plane, it is assumed that it does not depend on the z-axis, but even if it depends on the z-axis, there is no problem in the following explanation. Further, if there is a magnetic field component that is perpendicular to the reference two-dimensional plane, even if there is another magnetic field component that is not perpendicular to the reference two-dimensional plane, the rotor 1 rotates with respect to the rotor bottom plate 1A. It does not interfere with the application of torque.
In the following description, the rotor bottom plate 1A is formed of metal, and the rotational torque applied to the rotor bottom plate 1A is calculated. Further, for convenience, at first, orthogonal coordinates are adopted, the vertical upper side of the rotor bottom plate 1A is set to the + z direction, the rotor bottom plate 1A is raised in the xy plane, and the center of the rotor bottom plate 1A (rotation axis 11 and rotation). The origin is the intersection with the child bottom plate 1A). Further, the rotating magnetic fields generated by the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 due to the rotation of the magnet fixing base 7 are represented by the following equation (1).

In the above equation (1), r indicates the distance from the rotation axis, B _z indicates the magnetic field in the z-axis direction, B (r) indicates the magnetic field in the rotation radius direction, ω indicates the rotation angular velocity, and t indicates the rotation angular velocity. Time is indicated, n indicates the number of sets of magnets, and θ indicates the rotation angle of the magnet fixing base 7. In the case of the present embodiment shown in FIG. 1, n is 2 because the magnetic poles facing the sample table 6 are two sets of magnets having an N pole and an S pole.
Further, the electric field E generated (induced) by the time-varying magnetic field B is given by the following equation (2). The magnetic field B and the electric field E are vectors.

_{In this equation (2), it is assumed that the magnetic field B has the magnetic field B z} having only the z-direction component, but the following argument holds even if there are components other than the z-axis direction.
The current vector i (current vector of the induced induced current) flowing in the conductive disk-shaped rotor bottom plate 1A in the rotor 1 is i = σE, where σ is the conductivity. i and E are vectors. Since the divergence is "0" with respect to the current vector i, div i = 0. Therefore, for the electric field E, there is a vortex potential φ that satisfies the following equation (3).

In the above (3), E _x denotes an electric field in the x-axis direction in the two-dimensional coordinate system, E _y represents the electric field in the y-axis direction in the two-dimensional coordinate system.
Substituting the above equation (3) into the equation (2), the following equation (4) is obtained.

The following equation (5) can be obtained from the equations (2) and (4).

When the equation (5) is expressed by a concrete expression of the magnetic field, it is expressed as the following equation (6).

In the above equation (6), B (r) indicates the magnetic field in the radial direction of rotation, ω indicates the angular velocity of rotation, t indicates the time, n indicates the number of sets of magnets, and θ indicates the magnet fixing base 7. The rotation angle is indicated, and φ indicates the vortex potential.

The following equation (7) can be obtained from the above equation (6).

In the above equation (7), J _n (kr) indicates the type 1 Vessel function, k indicates the integral variable when executing the integration of the equation (7), r indicates the radius of gyration, and ω indicates the rotational angular velocity. , T indicates the time, and θ indicates the rotation angle of the magnet fixing base 7.
Further, in the above equation (7), the coefficient A (k) is the Hankel transform coefficient of B (r) and is represented by the following equation (8).

The following description shifts from a three-dimensional coordinate system to a cylindrical coordinate system. When the electric field Er in the radial direction and the electric field Eθ in the radial direction are obtained from each of the electric field Ex and the electric field Ey obtained by the equation (3), they can be expressed as the following equation (9). In the equation (9), θ indicates the rotation angle of the magnet fixing base 7, and r indicates the radius of gyration.

Considering the Lorentz interaction between the electric field (electric field based on the induced current) and the magnetic field in the above equation (9), the total integration of the radial components of the Lorentz force is obviously 0 due to the symmetry.
Further, the radial component is given by _{F θ} = σE _r B _z. The radial component is represented by the following equation (10) according to the equations (7) and (9). In equation (10), ω indicates the rotation angle velocity, θ indicates the rotation angle of the magnet fixing base 7, n indicates the number of sets of magnets, and the coefficient A (k) indicates the Hankel transform coefficient of B (r). Shown, J _n (kr) indicates the first-class Bessel function, k indicates the integral variable when performing the integration of Eq. (7), and r indicates the radius of gyration.

In the above equation (10), for the sake of simplicity, it is assumed that the distribution of the magnetic field in the radial direction can be approximated by the Bessel function. That is, when B (r) = B ₀ J _n (kr), the torque T given to the rotor bottom plate 1A by the rotating magnetic field can be obtained by the following equation (11). Here, B ₀ indicates the strength of the magnetic field. In equation (11), n indicates the number of sets of magnets, ω indicates the rotational angular velocity, B ₀ indicates the integral variable when performing the integration of equation (7), and J _n (kr) is the first. The seed Bessel function is shown.

As described above, it was found that the torque T acts on the rotor bottom plate 1A of the rotor 1 due to the rotating magnetic field. In an actual viscosity / elasticity measuring device, the rotor 1 rotates in the sample 100 due to the torque T acting on the rotor bottom plate 1A. Therefore, the rotation speed ΩM of the rotating magnetic field in the above is the rotation speed ΩM of the magnetic field. Replace with the rotation speed difference ΩM−ΩD, which is the difference from the rotation speed of the rotor bottom plate 1A of the rotor 1.
As a result, the eddy current generated in the conductor of the rotor bottom plate 1A of the rotor 1 receives the rotational torque (torque T), so that the rotational torque T is applied to the rotor bottom plate 1A of the rotor 1. become. As a result of the rotational torque being applied to the rotor bottom plate 1A of the rotor 1, the rotor 1 rotates in the sample 100 in the direction in which the rotational torque T is applied.

Further, as the rotor bottom plate 1A rotates, a viscous resistance torque due to the shear flow corresponding to the viscosity η of the sample 100 is applied to the rotor bottom plate 1A and the floating portion 1B. Due to this viscous resistance torque, the rotation speed ΩD of the rotor 1 does not reach the rotation speed ΩM of the magnetic field by the amount proportional to the viscous resistance torque.
Therefore, the magnitude of the rotational torque T applied to the rotor bottom plate 1A of the rotor 1 is the difference between the rotation speed ΩM of the rotating magnetic field (similar to the rotation speed of the motor 4) and the rotation speed ΩD of the rotor 1. It will be proportional. That is, when the rotation speed ΩD of the rotor 1 becomes constant, the constant rotation speed ΩD has an inversely proportional relationship with the viscosity η of the sample 100.

As described above, the rotation torque T applied to the rotor bottom plate 1A of the rotor 1, the rotation speed ΩD of the rotor 1 rotating in the sample 100, and the radius of the rotor 1 (that is, the rotor bottom plate 1A). Depending on the radius) r, the thickness (distance) between the rotor bottom plate 1A and the bottom of the inner surface of the sample container body 21, and the thickness (distance) between the lid 1D of the floating portion 1B and the sample container lid 22. It can be seen that the viscosity η of the sample 100 can be obtained.
Here, in the measurement of the viscosity η of the sample 100, the rotational torque T applied to the rotor bottom plate 1A of the rotor 1 is shown in FIG. 6 already described using a standard sample whose viscosity η is known in advance. As described above, it is obtained as a function of the rotation speed difference ΩMD between the rotation speed ΩM of the rotating magnetic field and the rotation speed ΩD of the rotor 1.

Further, when the sample 100 is filled only in the space below the rotor bottom plate 1A, that is, when the sample 100 is filled only between the bottom of the inner surface of the sample container main body 21 and the lower surface of the rotor bottom plate 1A, the sample 100 Is in contact with only the lower surface of the rotor bottom plate 1A. Therefore, when preparing the viscosity detection table shown in FIG. 6, it is necessary to measure the standard sample under the same conditions.
Further, if the density of the sample 100 for which the viscosity η is measured is known in advance, an appropriate sample having a uniform depth when the sample 100 is inserted into the sample container 2 of a common size corresponding to the density of the sample 100. A quantity of 100 is weighed with a scale. By this treatment, the depth of the sample 100 to be put into the sample container 2 at the time of measurement can be made uniform for each sample 100 having a different density.

Here, the accuracy of viscosity measurement in the viscosity / elasticity measuring device of the present embodiment will be described. In the viscosity / elasticity measuring device of the present embodiment, a known torque T is remotely applied to the rotor bottom plate 1A of the rotor 1 by a time-varying magnetic field (rotating magnetic field of rotation speed ΩM), and the rotation speed ΩD thereof. The viscosity η of the sample 100, which is the target substance, is measured by detecting.
The torque T applied to the rotor bottom plate 1A of the rotor 1 may be obtained from the magnitude of the given magnetic field by the above equation (11). Further, the measurement may be performed in advance using a standard sample having a known viscosity η. In principle, the accuracy of determining the magnitude of the torque T obtained from this can be arbitrarily improved, and in reality, it can be determined with an accuracy of 0.1% or more.

On the other hand, factors that determine the rotation speed ΩD of the rotor 1 include the protrusion 1C of the rotor bottom plate 1A of the rotor 1 and the groove portion inside the sample container body 21 in addition to the viscosity η of the sample 100 to be detected. _{The rotational torque T f} due to mechanical friction at the contact portion with the bottom surface of 21C can be mentioned. It has been theoretically and experimentally verified that the rotational torque T _f is as expressed by the following equation (12).

In the above equation (12), M indicates the weight of the rotor 1, ρ indicates the specific gravity of the sample 100, V indicates the volume of the portion of the rotor 1 submerged in the sample 100, and g indicates the gravitational acceleration. μ indicates the gravitational friction coefficient between the protrusion 1C of the rotor bottom plate 1A and the bottom surface of the groove 21C inside the sample container body 21, and Rc is the lower portion 11e of the rotation shaft 11 of the rotor 1 and the bottom surface 21s of the sample container body 21. The contact radius of the contact part is shown.

Further, due to the disk-shaped rotor bottom plate 1A having a radius R in the rotor 1, the rotation angle ω on the upper surface (the surface in contact with the lower surface of the rotor bottom plate 1A) with respect to the sample 100 having a thickness (depth) d, _{The torque T VIS} required to apply a strain having a rotation angular velocity of 0 on the lower surface (the surface in contact with the inner bottom surface of the sample container main body 21) is calculated by the following equation (13).

In the above equation (13), R indicates the radius of gyration of the rotor 1, η indicates the viscosity of the sample 100 which is the substance to be detected, and μ indicates the protrusion 1C of the rotor bottom plate 1A of the rotor 1 and the sample container body. The dynamic friction coefficient with the bottom surface of the groove portion 21C inside the 21 is shown, and d indicates the thickness of the sample 100 sandwiched between the rotor bottom plate 1A of the rotor 1 and the inner bottom surface of the sample container main body 21 facing each other.

Further, the coefficient α in the equation (13) is the required measurement accuracy of viscosity and elasticity. For example, when the required measurement accuracy α is 1%, α = 0.01. _{If the rotational torque T f} obtained from the equation (12) _{is smaller than α times the torque T VIS} obtained from the equation (13), that is, the required measurement accuracy α is obtained if the following equation (14) holds. be able to. _{The torque T-VIS} due to the viscosity of the sample 100 _{is superior to the torque Tf} of the mechanical friction due to the contact between the rotor 1 and the bottom surface 21s of the sample container body 21 by a magnitude of 1 / α times or more, thereby achieving an accuracy of α. Viscosity measurement is possible. Further, in order to stably rotate the rotor 1 in the sample 100, the rotor 1 is submerged in the sample 100, and the protrusion 1C of the rotor bottom plate 1A of the rotor 1 and the groove 21C inside the sample container body 21 are provided. Must be in contact with the bottom. Therefore, the relationship between the gravity applied to the rotor 1 and the buoyancy in the equation (14) is M-ρV> 0.

This measurement accuracy α is about 10% in the conventional method, but more preferably about 1%. Further, it is desired that an accuracy of about 0.1%, which is difficult to obtain by the conventional method, can be obtained.
As described above, according to the present embodiment, the amount of the sample 100, which is the substance to be detected, can be reduced as compared with the conventional measurement.
Further, according to the present embodiment, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 that generate the rotating magnetic field is directed toward the lower part of the sample table 6 on which the sample container 2 is arranged. It is possible to reduce the size of the viscoelasticity / elasticity measuring device as compared with the conventional one.

Further, as the magnet for generating the rotating magnetic field, two combinations of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 are used in FIG. In this case, in a plan view, a rotating magnetic field is generated by a combination of two sets in which two N poles and two S poles are alternately arranged. On the other hand, according to the equation (11), the number of sets of magnets for applying torque to the rotor bottom plate 1A of the rotor 1 may be any one or more sets, for example, two square magnets in a plan view. , The south pole and the north pole may be arranged so as to be staggered.

Further, the above-mentioned magnet fixing base 7 is rotated, and a rotating magnetic field is generated by using an electromagnet instead of generating a rotating magnetic field by the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3___. It may be configured.
FIG. 8 is a diagram showing an electromagnet in which a yoke 10 and teeth 10a, 10b, 10c, and 10d protruding from the yoke 10 are arranged on a reference two-dimensional plane. Winding CL1 is wound around the teeth 10a and 10c in different winding directions, and similarly, winding CL2 is wound around the teeth 10b and 10d in different winding directions to form an electromagnet.
Instead of rotating the magnet fixing base 7 with the motor 4 in FIG. 1 and generating a rotating magnetic field from the magnetic fields radiated by the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4, which are permanent magnets. A rotating magnetic field may be generated using the configuration of the electromagnet shown in FIG. 8 described above.

That is, a current is passed through the winding CL1 and the winding CL2 to generate a magnetic field perpendicular to the reference two-dimensional plane, and the direction of the flowing current is periodically changed to generate a magnetic field perpendicular to the reference two-dimensional plane. It may be rotated to form a rotating magnetic field. That is, each electromagnet is driven so that each of the electromagnets arranged on the circumference has a polarity different from that of other adjacent electromagnets. When driving this electromagnet, the polarity of each electromagnet may be changed with time to generate a rotating magnetic field.
In this case, the rotating magnetic field control unit 83 applies a current to the windings CL1 and CL2 in the electromagnet of FIG. 7, and periodically changes the direction of the flowing current to generate a rotating magnetic field.
By this rotating magnetic field, torque is applied to the rotor bottom plate 1A of the rotor 1 as in the case where a magnet is already used, and the rotational movement of the rotor bottom plate 1A about the rotation shaft 11 as the rotation center is performed in the sample 100. To obtain the viscosity η of the sample 100.

Further, the rotating magnetic field control unit 83 may arbitrarily change the rotation cycle and the rotation direction of the rotating magnetic field applied to the rotor bottom plate 1A of the rotor 1.
For example, by periodically sweeping the rotation direction of the rotating magnetic field and the rotation speed, it is possible to apply a rotational torque that changes periodically to the rotor 1.

FIG. 9 is a schematic view showing another configuration example of the shape of the rotor bottom plate in the rotor 1. According to the form of FIG. 9, each of the sample container main body 21 and the sample container lid 22 is the same as the above-described form, but the rotor bottom plate 1A'constituting the rotor 1 has a triangular cross section. It has become. That is, the cross section of the rotor bottom plate 1A'is thick so that the distance between the lower surface of the rotor bottom plate 1A'and the inner bottom surface of the sample container body 21 increases from the central portion toward the outer peripheral portion in the radial direction. Is formed so that it gradually becomes thinner.
As a result, the thickness of the sample 100 sandwiched between the lower surface of the rotor bottom plate 1A'and the inner bottom surface of the sample container main body 201 increases in proportion to the distance of the rotor 1 from the rotating shaft 11. As a result, it is possible to realize a uniform deformation of the shear rate everywhere in the sample 100 housed in the sample container main body 21. Therefore, this form of the rotor bottom surface 1A'is effective for measuring the viscosity and elasticity of a non-Newtonian fluid whose viscosity value changes depending on the shear rate.

Next, the measurement of elasticity using the viscosity / elasticity measuring device according to the present embodiment will be described. The viscosity / elasticity measuring device having the configuration shown in FIGS. 1 and 3 (or FIG. 4) will be described.
According to this embodiment, for a substance having an elastic modulus such as gel or rubber, or a substance such as a polymer solution in which the elastic modulus is generated by relaxing the viscosity, instead of obtaining the viscosity like a liquid. It is possible to measure the viscosity and elastic modulus at the same time by the displacement from the stationary position when a constant torque is applied.

Here, the elastic modulus is, so to speak, a spring constant, and corresponds to a restoring force proportional to the rotational deformation of the sample 100.
Therefore, when there is elasticity in addition to viscosity, the restoring force due to the elastic modulus increases in proportion to the degree of strain. Therefore, after the rotor 1 starts rotating, the rotor 1 stops rotating at a rotation angle θ in which the elastic force proportional to the spring constant of the sample and the rotational torque due to the rotational magnetic field are balanced. As the magnet fixing base 7 rotates counterclockwise, as described above, a counterclockwise rotational torque is applied to the rotor 1 in the sample 100.

Then, the rotation of the floating rotor 1 is stopped at the position of the rotation angle θ where the rotational torque applied to the rotor 1 and the repulsive force due to elasticity are balanced.
Here, in the rotation detection unit 81, the motor 4 is not rotating, and the motor 4 is rotated at the position of the mark 30 of the rotary blade of the rotor 1 when the magnet fixing base 7 is stopped and at a predetermined rotation speed ΩM. After that, the rotation angle θ is obtained from each captured image with the position of the mark 30 when the rotation is stopped. Elasticity can be obtained from this angle θ.

FIG. 10 is a diagram showing the relationship between the rotation speed ΩM (that is, rotation torque) of the motor 4 and the rotation angle θ at which the rotor 1 stops. In FIG. 10, the horizontal axis represents the rotation speed ΩM of the motor 4, and the vertical axis represents the rotation angle θ at which the rotor 1 stops.
That is, in the case of the viscosity / elasticity measuring device shown in FIGS. 1 and 3, the magnet fixing base 7 is rotated by the motor 4, and the first magnet 3_1 and the second magnet 3_2 arranged on the magnet fixing base 7 are arranged. Each magnet of the third magnet 3_3 and the fourth magnet 3_4 generates a rotating magnetic field corresponding to the rotation speed of the motor 4.

Then, the rotation magnetic field control unit 83 changes the rotation speed of the motor 4 according to a preset step, obtains the rotation angle θ for each rotation speed, and obtains the relationship between the rotation speed ΩM and the rotation angle θ. Create the graph shown in 10. Here, for a plurality of standard samples whose elasticity is known in advance, the above-mentioned processing is performed in order to create standard data used for measuring the elasticity of the sample 100 whose elasticity is unknown as well as the viscosity. As in the case of creating the standard viscosity data, the standard sample is placed in the sample container 2 and the rotation angle θ described above is measured.

FIG. 11 is a diagram showing the relationship between elasticity and the ratio of rotation speed and rotation angle. In FIG. 11, the horizontal axis shows elasticity (elastic modulus: Pa), and the vertical axis shows the proportional coefficient between the rotation speed ΩM and the rotation angle θ. Here, the viscosity and the rotation angle θ are inversely proportional.
FIG. 11 shows standard data of elasticity used for elasticity measurement, which is created by associating the inclination (ratio of rotation speed ΩM and rotation angle θ) of each standard sample in FIG. 10 with the viscosity of the corresponding standard sample. is there.
In the actual measurement of the unknown elastic sample 100, the sample 100 to be measured is placed in the sample container 2, and the rotating magnetic field control unit 83 rotates the motor 4 at a preset rotational speed as in the case of the standard sample. ..

Then, the rotation detection unit 81 obtains the rotation angle θ for each rotation speed and outputs the rotation angle θ to the viscosity detection unit 82.
The viscosity detection unit 82 obtains a proportional coefficient between the rotation speed ΩM supplied from the rotation detection unit 81 and the rotation angle θ, and reads the elasticity data corresponding to the proportional coefficient from the standard data of the standard data storage unit 84. The read data is output as the elasticity of the sample 100.

It is also possible to measure elasticity and viscosity at the same time by changing the rotational torque applied to the rotor bottom plate 1A of the rotor 1 with time. In this case, the magnet that generates the rotating magnetic field is composed of the electromagnet shown in FIG. 7.
For example, after applying an exciting current to the electromagnet and applying a predetermined rotational torque to the rotor bottom plate 1A of the rotor 1, the application of the exciting current is stopped, and the rotation of the rotor 1 after the stop is stopped. Observe the condition.

At this time, the rotor 1 causes rotational vibration according to the elasticity of the sample 100 in contact with the rotor 1. Here, the period of rotational vibration and the vibration time are proportional to elasticity, and the attenuation rate of the amplitude of rotational vibration is proportional to viscosity.
Therefore, a rotating magnetic field is applied to the rotor bottom plate 1A of the rotor 1 with respect to the attenuation rate of the amplitude of the rotational vibration and the period and vibration time for each of a plurality of standard samples whose viscosity and elasticity are known in advance. As a result, standard data is created and stored in the standard data storage unit 84 in advance.

Next, when measuring a substance to be measured having an actual unknown viscosity and elasticity, the viscosity detection unit 82 uses a rotor to determine the attenuation rate of the amplitude of the sample 100, which is the substance to be measured, and the period and vibration time. The viscosity corresponding to the decay rate of the measured amplitude and the elasticity corresponding to the period and the vibration time are read out from the standard data of the standard data storage unit 84, respectively.
Then, the viscosity detection unit 82 outputs the viscosity and elasticity read from the standard data as the viscosity and elasticity of the sample 100 to be measured.
As described above, according to the present embodiment, the viscosity and elasticity of the sample 100 can be collectively measured at the same time.

Further, by periodically sweeping the rotation direction of the rotational magnetic field applied to the rotor bottom plate 1A of the rotor 1 and the rotation torque (rotational number ΩM of the motor 4), the rotor bottom plate 1A of the rotor 1 is subjected to. A periodic rotational torque can be applied.
Then, while changing the period for sweeping the rotation direction and the rotation torque, the amplitude and phase of the rotation vibration of the rotor 1 are observed from the captured image obtained by capturing the mark 30 of the rotor 1, thereby increasing the viscosity. It is possible to measure the elasticity independently.
That is, the observation of this rotational vibration detects the damped vibration after the magnetic field is erased as a frequency spectrum, which is basically the same as the measurement of viscosity and elasticity after the magnetic field is erased. ..

Next, a specific application example in the viscosity / elasticity measuring device (mechanical physical property measuring device) shown in FIG. 1 will be described.
The sample container main body 21 used a glass petri dish having an inner diameter of 40 mm and an internal side wall height of 10 mm. Then, after 5 mL of the sample 100, which is the substance to be measured, was put into the sample container main body 21, the sample container main body 21 was sealed with the sample container lid 22. Here, for example, the temperature of the sample 100 was set to 20 ° C.
As shown in FIG. 6, two types of standard samples whose viscosities were known in advance were 0.5 (mPa · s) and 1.0 (mPa · s).

Then, a rotational torque was applied to the rotor bottom plate 1A of the rotor 1 on the surface of this standard sample to rotate the rotor 1. In this case, the lower surface of the rotor bottom plate 1A is in contact with the sample 100. Here, the rotor bottom plate 1A is a disk of an aluminum plate having a diameter of 20 mm and a thickness of 1 mm, and an aluminum ball having a diameter of 2 mm is attached as a protrusion 1C to the bottom surface of the disk at the center of rotation. For the floating portion 1B, a glass tube having an outer diameter of 20 mm, an inner diameter of 16 mm, and a length (height as a side wall) of 4 mm was used.

Next, the rotating magnetic field control unit 83 drives the motor 4 to rotate the magnet fixing base 7.
As a result, a magnetic field perpendicular to the rotor bottom plate 1A of the rotor 1 generated by the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3___ is applied to the first magnet 3_1, the second magnet 3_2, and the second magnet. A rotating magnetic field is applied to the rotor bottom plate 1A of the rotor 1 by rotating the 3 magnets 3_3 and the 4th magnet 3_4. Due to this rotating magnetic field, the rotor bottom plate 1A of the rotor 1 is applied with rotational torque and rotates in the same direction as the rotation direction of the applied rotating magnetic field.
Then, for example, the rotation detection unit 81 stores the rotating moving image of the mark 30 of the rotor bottom plate 1A of the rotor 1 as an image taken by the rotation detection sensor (imaging element) in its own internal storage unit. The rotation cycle of the mark 30 is obtained by image processing, and the rotation number of the rotor 1 is obtained from the rotation cycle of this mark.

Each time the rotation speed ΩM of the motor 4 is changed, the rotation speed ΩD of the corresponding rotor 1 is obtained, and as shown in FIG. 6, the rotation speed ΩD of the rotor 1 and the rotation speed ΩM are obtained for each standard sample having different viscosity. And find the correspondence with the difference of ΩM.
In FIG. 6, the relationship showing the relationship between the rotation speed ΩD of the rotor 1 of each standard sample and the difference between the rotation speeds ΩM and ΩM is a straight line. Therefore, FIG. 6 shows that the viscosity can be obtained only from the relationship between the rotation speed of the rotor 1 and the rotational torque applied to the rotor 1.
As a result, it can be seen that the viscosity can be accurately measured by using the standard data.

A program for realizing the function of the viscosity / viscoelasticity measuring device of FIG. 1 in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. Therefore, a process for determining the viscosity of the sample may be performed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices.
Further, the "computer system" shall also include a WWW system provided with a homepage providing environment (or display environment). Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Furthermore, a "computer-readable recording medium" is a volatile memory (RAM) inside a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, it shall include those that hold the program for a certain period of time.

Further, the program may be transmitted from a computer system in which this program is stored in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the above program may be for realizing a part of the above-mentioned functions. Further, a so-called difference file (difference program) may be used, which can realize the above-mentioned functions in combination with a program already recorded in the computer system.

1 ... Rotor 1A ... Rotor bottom plate 1A
1B ... Floating part 1C ... Protruding part 2 ... Sample container 4 ... Motor 5 ... Rotation detection sensor 6 ... Sample stand 7 ... Magnet fixing base 8 ... Viscosity measuring part 11 ... Rotating shaft 21 ... Sample container body 21C ... Groove 22 ... Sample container Lid 30 ... Mark 3_1 ... 1st electromagnet 3_2 ... 2nd electromagnet 3_3 ... 3rd electromagnet 3_4 ... 4th electromagnet 81 ... Rotation detection unit 82 ... Viscous detection unit 83 ... Rotation magnetic field control unit 84 ... Standard data storage unit 85 ... Device control Department

Claims (10)

A rotor that is partially or wholly made of a conductive material and has a protruding protrusion at the center of rotation at the bottom of the rotor.
A sample container in which a substance to be detected to be detected for viscosity is placed, and the rotor is arranged in a state where the protrusion is in contact with the bottom of the inner surface of the sample container in contact with the substance to be detected.
A time-varying magnetic field is applied to the rotor, an induced current is induced in the rotor, and a rotational torque is applied to the rotor by the Lorentz interaction between the induced current and the magnetic field applied to the rotor. Rotation control unit to rotate
A rotation detection unit that detects the rotation speed of the rotor,
It has a viscoelasticity detection unit that detects the viscosity and elasticity of the substance to be detected in contact with the rotor according to the number of rotation speeds of the rotor.
The rotor is rotationally symmetric, the axis of rotational symmetry of the rotor is the axis of rotation, and the buoyancy position due to the buoyancy generated corresponding to the portion of the rotor submerged in the detection target substance and the rotor There each of the center of gravity on the rotation axis, and Ri vertically downward near the center of gravity relative to the center of buoyancy position, the rotor is relative to the upper portion of the circular bottom plate, said bottom plate in a plan view A columnar floating portion is provided so that the outer periphery of the column and the outer periphery of the column overlap each other, the floating portion has a large buoyancy as compared with the bottom plate, and the buoyancy position is the rotor of the rotor. A viscosity / elasticity measuring device characterized in that it is generated corresponding to the floating portion submerged in the substance to be detected. The viscosity / elasticity measuring apparatus according to claim 1, wherein the radius of the rotor is determined by the following formula.

The viscosity / elasticity measuring device according to claim 1, wherein the floating portion has a hollow inside of the cylinder and has a cylindrical shape. The first to third claims are characterized in that the distance between the center of gravity position and the buoyancy position is set to be equal to or greater than the distance having a restoring force for holding the rotation axis in the rotation of the rotor in the vertical direction. The viscosity / elasticity measuring device according to any one of the items. Further having a storage unit for storing standard data obtained by previously measuring the relationship between the rotational torque applied to the rotor in a plurality of substances having known viscosity and the rotational speed of the rotor.
From claim 1, the viscoelasticity / elasticity of the detection target substance is obtained by comparing the relationship between the rotation torque and the rotation speed of the detection target substance detected by the viscoelasticity detection unit with the standard data. The viscoelasticity / elasticity measuring device according to any one of claims 4. A mark is attached to the surface of the rotor.
The viscoelasticity / elasticity measuring apparatus according to any one of claims 1 to 5 , wherein the rotation detecting unit detects the rotation speed of the rotor by detecting the rotation of the mark. According to claim 1, the number of rotations of the rotor is detected by irradiating the rotor of the rotor with a laser and optically measuring a change in the reflected light or an interference pattern thereof. The viscosity / elasticity measuring apparatus according to any one of claim 5. The viscoelasticity according to any one of claims 1 to 7 , wherein the bottom of the inner surface of the sample container in contact with the rotor is formed in a concave shape having a smooth flat surface or a smooth curved surface. Viscoelasticity measuring device. According to any one of claims 1 to 8 , the rotor is formed so as to be thinner in proportion to the distance from the rotation axis in rotation with respect to the diameter direction of the rotor. The described viscosity / elasticity measuring device. A rotor in which a substance to be detected to be detected for viscosity and elasticity is housed in a sample container, and a rotor which is partially or wholly made of a conductive material and has a protruding protrusion at the center of rotation at the lower portion thereof is detected. The process of arranging the protrusion in contact with the target substance in contact with the bottom of its inner surface,
A time-varying magnetic field is applied to the rotor, an induced current is induced in the rotor of the rotor, and the Lorentz interaction between the induced current and the magnetic field applied to the rotor causes the rotor to undergo a Lorentz interaction. The process of applying rotational torque to rotate,
The process of detecting the rotation speed of the rotor and
The rotor is rotationally symmetric, the axis of rotational symmetry of the rotor is the axis of rotation, and the rotation includes a viscous detection process for detecting the viscosity and elasticity of the substance to be detected in contact with the rotor based on the number of rotations. The buoyancy position due to the buoyancy generated corresponding to the portion of the child submerged in the detection target substance and the center of gravity position of the rotor are each on the rotation axis, and the center of gravity position is at the buoyancy center position. Ri vertically downward near against, to the upper of the rotor circular bottom plate provided with a separated portion of the cylindrical shape so as to overlap with the outer periphery of the bottom plate periphery and pillars are in a plan view, the float A method for measuring viscosity / elasticity , wherein the portion has a large buoyancy as compared with the bottom plate, and the buoyancy position is generated corresponding to the floating portion submerged in the detection target substance of the rotor. ..

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