JP2016031352A - Viscosity/elasticity measuring device and viscosity/elasticity measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a viscosity/elasticity measuring device that requires a smaller amount of sample substance to be detected than a conventional one, uses a disposable sample container for storing the substance to be detected as an inexpensive one and measures a wide range of viscosity of the sample substance from low viscosity to high viscosity.SOLUTION: A viscosity/elasticity measuring device according to the invention includes: a rotor that is partly or wholly made of a conductive material, includes a disk fixed vertically to a rotary shaft and includes a smoothly-convexed shaft tip of the rotary shaft; a sample container in which a sample whose viscosity is detected is placed and a rotor is arranged in a contacting state between the disk and the sample; a magnet that is arranged around the sample container and applies a magnetic field to the rotor; a rotation control part that applies a rotational magnetic field to the rotor by driving the magnet and rotates it by giving rotation torque; a rotation detection part that detects rotary speed of the rotor; and a viscosity/elasticity detection part that uses a value of rotation rate of the rotor to detect viscosity and elasticity of the sample contacting the rotor. A disk radius of the rotor is determined by a prescribed formula.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a viscosity / elasticity measuring apparatus and a viscosity / elasticity measuring method for measuring viscosity / elasticity which are mechanical properties of a substance.

Conventionally, in order to detect the mechanical properties of a target substance, viscosity (sometimes referred to as viscosity in the following description) and elasticity are measured (for example, see Patent Document 1).
Viscosity / elasticity measurement includes quality control, performance evaluation, 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.
Conventionally known methods for measuring viscosity include the following methods.

(1) Viscosity tube method, (2) Method of contacting vibrator, (3) Method of using surface acoustic wave, (4) Method of using rotor, (5) Method of dropping hard sphere, (6) Motion A light scattering method, (7) a Zim type viscosity measurement method, (8) an EMS (Electro-Magnetically Spinning) viscosity measurement method, and (9) a disk floating type EMS viscosity measurement method.

Japanese Patent No. 5093599

However, among the methods described above, the method (1) has the disadvantages that many operations such as washing the inside of the glass capillary tube are required for the measurement, and that the maintenance of the glassy viscometer is complicated. there were.
In addition, the methods (2) to (5) have a drawback that the viscosity of a low-viscosity material cannot be measured because accurate measurement is not possible unless the viscosity is at least 10 mPa · s (Pascal second) or more. .
Furthermore, the method (6) has a drawback that the measuring apparatus becomes large, and there is a difficulty that it cannot be applied to other than the transparent sample.

In the methods (7) and (9), the probe (rotor) floating on the surface of the sample (sample surface) is rotated by buoyancy, so energy loss to cause ripples on the sample surface is ignored. There is a disadvantage that it is impossible. In the methods (7) and (9), when a molecular adsorption film is formed on the surface of the sample, a measurement error occurs due to the surface viscoelasticity of the film, and further, rotation causes the object to sink. The density of the sample material needs to be known because it depends on the depth from the sample surface.
In all the methods (1) to (7), since the sample container is expensive and needs to be reused, it is necessary to clean the sample container after the measurement. Further, if the sample measured last time is not completely removed by this cleaning, the influence of the immediately preceding sample substance remains, and there is a restriction that the measurement of the viscoelasticity of the sample substance to be measured cannot be performed with high accuracy.

Further, the method (8) has a disadvantage that the viscosity measurement accuracy is limited by mechanical friction between the lower part of the rotor and the sample container. For example, when the viscosity of a sample material having a low viscosity such as pure water is measured, it is difficult to measure the viscosity with an accuracy higher than 1% due to the influence of mechanical friction. In the method (8), when an inexpensive aluminum sphere is used as the rotor, the smallest diameter aluminum sphere has a diameter of 1 mm. Therefore, as described in Patent Document 1, a theoretical pure viscosity is obtained. Measurement accuracy is limited to 10%.
Further, the above-described viscoelasticity measuring methods generally used so far have a drawback that a certain amount of sample material is required to obtain a certain accuracy.

In addition, there is a drawback in that the measurement accuracy is poor for sample materials having a viscosity of less than 10 mPa · s, and the measurement is based on a rotary viscometer or light scattering, which makes the apparatus large, making it impossible to perform simple measurements. There were restrictions.
For the reasons described above, the conventional principle-based method has a limitation that it is difficult to measure with a small amount of sample material regarding universal physical quantities of sample materials such as liquid and other soft materials such as viscosity and elasticity. is there. Further, in the method based on the conventional principle, it is difficult to measure a low-viscosity sample material with high accuracy, and as described above, it is necessary to completely clean the sample material attached to the measurement sample container. There is also a restriction.

  The present invention has been made in view of such circumstances, and the amount of the substance of the sample to be detected is smaller than that of the conventional example. An object of the present invention is to provide a viscosity / elasticity measuring apparatus and a viscosity / elasticity measuring method that can measure the viscosity of a sample material over a wide range from low viscosity to high viscosity.

  In order to solve the above-described problems, the viscosity / elasticity measuring apparatus of the present invention is partially or entirely made of a conductive material, and the disk is fixed so that the surface of the disk is perpendicular to the rotation axis. A rotor having a smooth convex shape at the tip of the rotating shaft, and a detection target substance whose viscosity is to be detected, and the surface of the disk is detected A sample container in which the rotor is arranged in contact with a target substance, a magnet that is arranged around the sample container and applies a magnetic field to the rotor, and the dynamic magnetic field application magnet is driven to A time-varying magnetic field is applied to the rotor, an induced current is induced in the disk of the rotor, and the rotor is rotated by Lorentz interaction between the induced current and the magnetic field applied to the rotor. A rotation control unit that rotates by applying torque; and a rotation speed of the rotor And a viscoelasticity detecting unit for detecting the viscosity and elasticity of the detection target substance in contact with the rotor based on the rotational speed of the rotor, and the disk of the rotor The radius is determined by the following equation (14).

  The viscosity / elasticity measuring apparatus according to the present invention is characterized in that the convex portion of the shaft tip of the rotating shaft of the rotor is in contact with the bottom of the inner surface of the sample container.

  The viscosity / elasticity measuring apparatus according to the present invention includes a storage unit for storing standard data in which a relationship between a rotational torque applied to the rotor in a plurality of substances whose viscosity is known and a rotational speed of the rotor is measured in advance. Further, the viscosity / elasticity of the detection target substance is obtained by comparing the standard data with the relationship between the rotational torque and the rotation speed of the detection target substance detected by the viscosity detection unit.

  The viscosity / elasticity measuring apparatus according to the present invention is characterized in that a mark is attached to the rotor, and the rotation detector detects the rotation speed of the rotor by detecting the rotation of the mark. .

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

  The viscosity / elasticity measuring apparatus of the present invention is characterized in that the bottom of the inner surface of the sample container in contact with the rotor is formed into a smooth flat surface or a smoothly curved concave shape.

  In the viscosity / elasticity measuring apparatus according to the present invention, a lid that closes the upper opening of the sample container is provided for the sample container, and the rotating shaft of the rotor is the sample filled with the detection target substance. It is provided rotatably between the bottom of the inner surface of the sample container and the inner surface of the lid.

  The viscosity / elasticity measuring apparatus of the present invention is formed such that the space inside the sample container is thicker in proportion to the distance from the rotation axis with respect to the diameter direction of the disk of the rotor. It is characterized by that.

  In the viscosity / elasticity measuring method of the present invention, a sample container is filled with a detection target substance to be detected for viscosity and elasticity, and the detection target substance is partially or entirely made of a conductive material, Has a frame shape in which the surface of the disk is fixed perpendicularly to the rotation axis, and the detection target substance is a circle having a smooth convex shape at the tip of the rotation axis. A step of placing the plate in contact with the surface of the plate, and driving a dynamic magnetic field applying magnet arranged around the sample container to apply a time-varying magnetic field to the rotor, so that the disk of the rotor An induced current is induced in the rotor, and a process of rotating the rotor by applying rotational torque to the rotor by Lorentz interaction between the induced current and a magnetic field applied to the rotor, and detecting the rotational speed of the rotor Detection of contact with the rotor according to the process and the rotational speed Radius of the disc of the rotor and a viscosity detection step of detecting the viscosity and elasticity of the elephants material described later (14), characterized in that it is determined by the equation.

As described above, according to the present invention, the viscosity and elasticity are measured from the relationship between the rotational torque applied to the rotor rotating in contact with the object to be detected and the rotational speed, so that the viscosity ranges from low to high. Viscosity over a wide area can be measured with a simpler apparatus than in the past.
In particular, according to the present invention, the rotation of the rotor is inhibited by adjusting the weight of the rotor, the radius of the contact portion with the sample container bottom, and the rotation radius of the rotor according to a predetermined formula. Since the effect of mechanical friction with other than the sample can be arbitrarily reduced and the measurement accuracy can be improved, highly accurate measurement can be performed.
Further, according to the present invention, a test tube or the like can be used for a sample container in which an object to be detected is placed, and a rotor capable of mass production can be employed. Can be dispensed with, making the work more efficient.

It is a schematic block diagram which shows the structural example of the viscosity and elasticity measuring apparatus by one Embodiment of this invention. It is the conceptual diagram which looked at the sample container 2 explaining the arrangement | positioning in the sample container 2 of the rotor 1 from the side surface. It is a top view which shows the fixed state of the magnet provided in order to generate | occur | produce the rotating magnetic field in the magnet fixing stand. It is a figure which shows the magnetic field which a magnet generate | occur | produces with respect to the rotary blade 12 with respect to the outer side of the rotary blade 12 rotating from the rotating shaft 11 of the rotor 1. FIG. It is a figure which shows the relationship between the rotation speed (ohm) M of the motor 150, and each rotation speed (omega | ohm) D of the rotor 110 in a corresponding standard sample in the standard sample which has several different viscosity. It is a figure which shows the electromagnet by which the yoke 10 and the teeth 10a, 10b, 10c, and 10d which protruded from this yoke 10 are arrange | positioned on the reference | standard two-dimensional plane. 3 is a schematic diagram showing a new form of a sample container filled with a sample 100. FIG. 6 is a schematic diagram illustrating another configuration of a sample container filled with a sample 100. FIG. It is a schematic diagram showing the other structure of a rotor. It is a figure which shows the relationship between rotational speed (omega) M (namely, rotational torque) of the motor 4, and rotation angle (theta) which the floating rotor 1 stops. It is a figure which shows the relationship between elasticity and the ratio of a rotational speed and a rotation angle.

Hereinafter, a viscosity / elasticity measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration example of a viscosity / elasticity measuring apparatus according to an embodiment of the present invention.
In this figure, the viscosity / elasticity measuring apparatus in this 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. , A sample stage 6, a magnet fixing stage 7, and a viscosity measuring unit 8.

  The rotor 1 is partly or entirely (whole) made of a conductor (for example, a metal material). Moreover, the rotor 1 has the rotating shaft 11 and the disk shaped member, for example, the rotary blade 12 formed with the metal material. In addition, since the rotor 1 detects rotation (described later), a mark having a size that can be detected by an imaging element or the like is provided on any surface (rotary blade 12 in this embodiment).

  Further, only a part of the rotor 1 (particularly, the part of the rotor blade 12) uses a conductor such as aluminum, and the other part can be made of a material such as plastic or vinyl. The portion of the rotary blade 12 may be formed by, for example, attaching a commercially available aluminum foil or the like to the upper surface of a plastic disc. Thereby, the cheap rotor 1 can be easily formed from a commercially available plastic disk and a commercially available alum foil.

  The sample container 2 includes a sample container main body 21 and a sample container lid 22. Further, the sample container 2 accommodates a detection target object (hereinafter referred to as a sample) for measuring a viscosity (that is, a viscosity coefficient) η as a mechanical physical 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 only needs to be slightly larger than the diameter of the rotor blade 12 in the rotor 1.

  In the sample container lid 22, a hole through which the rotation shaft 11 of the rotor 1 passes is opened at the center. In the sample container 2, the rotor 1 is arranged so that the rotor blade 12 is in contact with the sample 100 that is the detection target, that is, part or all of the rotor 1 is submerged in the detection target. As the sample container 2, a commercially available petri dish or the like made of glass or plastic can be used for both the sample container main body 21 and the sample container lid 22. For this reason, the sample container 2 can be a disposable commercially available sample container and can be prepared at low cost.

As described above, in this embodiment, the rotor 1 and the sample container 2 can be made inexpensive. For this reason, 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 requiring special attention is discarded.
As a result, as with post-treatment problems such as incineration and sterilization, it can be easily performed as with the disposal of other medical devices.

FIG. 2 is a conceptual diagram illustrating the arrangement of the rotor 1 in the sample container 2 as viewed from the side. FIG. 2A shows a side surface of the sample container for explaining the arrangement of the rotor 1 in the sample container 2. FIG. 2B shows an enlarged view of a portion of region A in FIG.
The rotor holding part 50 has a rotating shaft holding hole 51 through which the rotating shaft 11 passes so that the rotating shaft 11 of the rotor 1 faces the vertical direction with respect to the ground.
The rotation shaft holding hole 51 is formed smoothly so that the inner surface in contact with the rotation shaft 11 reduces friction. Further, the rotor blade 12 of the rotor 1 is provided with a mark 30 on the surface 12s.

Here, the effect of gravity applied in the direction in which the rotating shaft 11 is tilted is extremely small as long as the rotating shaft 11 is oriented substantially in the vertical direction, and the frictional force at the contact portion between the rotating shaft 11 and the inner surface of the rotating shaft holding hole 51 is Can be ignored by the discussion below.
That is, in the actual structure of the rotating shaft holding hole 51, the rotating shaft 11 rolls on the inner surface of the rotating shaft holding hole 51 by making the inner diameter of the rotating shaft holding hole 51 slightly larger than the diameter of the rotating shaft 11. Exercise. For this reason, the frictional force at the contact portion between the rotating shaft 11 and the inner surface of the rotating shaft holding hole 51 is mainly rolling friction, and the influence on the rotation of the rotating shaft 11 is further slight.

Further, the sample container lid 22 is provided with a through hole 22h through which the rotary shaft 11 passes so as to overlap with the rotary shaft holding hole 51 in a plan view from the upper surface.
A groove portion 21 t into which the lower portion 11 e of the rotating shaft 11 of the rotor 1 is inserted is provided on the bottom surface 21 s inside the sample container main body 21. The groove 21t is provided at a position overlapping with each of the through hole 22h and the rotation shaft holding hole 51 in a plan view from the upper surface.
The groove portion 21t is formed smoothly so that the inner surface of the rotating shaft 11 that contacts the lower portion 11e is reduced in friction. The lower part 11e of the rotating shaft 11 is inserted in the groove part 21t. Here, the lower part 11e of the rotating shaft 11 is formed smoothly so that the lower surface in contact with the groove 21t is reduced in friction. For this reason, the frictional force at the contact portion between the inner surface of the groove 21t and the lower surface of the lower portion 11e of the rotating shaft 11 is mainly rolling friction, and the influence on the rotation of the rotating shaft 11 is even smaller.

The sample container 2 is filled with a sample 100 in a space sandwiched between the sample container main body 21 and the sample container lid 22. Thereby, with the rotation of the rotor 1 arranged in the sample container 2, shear flow is generated in the sample 100 sandwiched between the rotor blade 12 and the sample 100, and the viscous resistance against the rotation of the rotor 1. Torque is generated. This viscous resistance torque will be described later.
In FIG. 2, the sample 100 is filled in a space between the sample container main body 21 and the sample container lid 22. However, when the sample 100 enough to fill the space between the sample container main body 21 and the sample container lid 22 cannot be prepared, the lower surface of the rotary blade 12 can be obtained even if the entire rotary blade 12 is not immersed in the sample 100. It is only necessary that the sample 100 is inserted so that the whole is in contact with the liquid surface of the sample 100. In this case, the viscous resistance torque that decreases because the upper surface of the rotary blade 12 is not in contact with the sample 100 may be predicted from the filling state of the sample 100.

Further, the rotor 1 rotates with the lower portion 11e of the rotating shaft 11 inserted into the groove portion 21t. Therefore, the distance between the lower surface of the rotary blade 12 and the bottom surface 21s inside the sample container main body 21 can be kept constant with high accuracy, and the displacement speed of the rotary blade 12 in the sample 100 can be stably maintained. The accuracy of 100 viscosity measurements is improved.
In FIG. 2, the sample container 2 filled with the sample 100 is provided on the upper surface of the sample stage 6. A magnet fixing base 7 to which the motor shaft 4 a of the motor 4 is connected is provided below the sample base 6 in parallel with the sample base 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 sample 3_2 (fourth magnet 3_4) are provided on the upper surface of the magnet fixing base 7.

  Returning to FIG. 1, the magnet fixing base 7 is a flat plate member that fixes a magnet that generates a rotating magnetic field. For example, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 are 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 rotary blade 12. Each of the first magnet 3 </ b> _ <b> 1 and the second magnet 3 </ b> _ <b> 3 is provided such 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 blade 12. Each of the second magnet 3_2 and the fourth magnet 3_4 is provided such that the N pole is in contact with the upper surface side of the magnet fixing base 7 and the S pole is opposed to the rotor blade 12.

  Therefore, each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet is arranged so that the magnetic poles having different polarities from the adjacent magnets face the lower surface of the sample container 2. In addition, 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 thereof are arranged in parallel to each other so that the height of the upper surface is the same.

  FIG. 3 is a plan view showing a fixed state of a magnet provided to generate a rotating magnetic field in the magnet fixing base 7. FIG. 3A shows the arrangement of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet. The first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 are alternately arranged symmetrically with respect to the rotation axis of the magnet fixing base 7. On the other hand, FIG. 3B shows the arrangement of each of the fifth magnet 3_5 and the sixth magnet 3_6.

  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 (N, N = 2n, n is an integer of n ≧ 1) small magnets are arranged along the rotation direction of the rotor blades 12 of the rotor 1 in the sample container 2. You may arrange | position so that the magnetic pole of an upper surface may alternate with N pole and S pole. 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 becomes a horizontal plane.

FIG. 4 is a diagram illustrating a magnetic field generated by a magnet with respect to the rotating blade 12 from the rotating shaft 11 of the rotor 1 toward the outer side of the rotating rotating blade 12.
Here, the declination θ takes one point on the circuit path 23, and this one point and the z axis are the rotation axes, and the clockwise direction from the x axis in the two-dimensional coordinate system composed of the x axis and the y axis. The rotation angle of the rotor 1 is shown. Therefore, the deflection angle θ increases from 0 to 2π [radian], and the circulation path 23 is made a round by 2π.

  That is, when the rotor 1 rotates in the counterclockwise direction, the rotor passes in the order of the first magnet 3_1 → the second magnet 3_2 → the fourth magnet 3_4 → the third magnet 3_3. At this time, when the declination θ is 0 to π / 2, the first magnet 3_1 is disposed, and from π / 2 to π, the second magnet 3_2 is disposed. From π to 3π / 2, the fourth magnet 3_4. Is an arrangement region of the third magnet 3_3 from 3π / 2 to π.

In FIG. 4, the z-axis is a vertical direction of a plane formed by the surfaces of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 (a two-dimensional plane including the x-axis and the y-axis). Is a coordinate axis parallel to. A white arrow represents a magnetic field vector composed of the magnitude and direction of the magnetic field at an arbitrary height z = z0.
Here, when the magnet fixing base 7 is rotated clockwise by the motor 4, each of the first magnet 3_1, the second magnet 3_2, the fourth magnet 3_4, and the third magnet 3_3 also rotates clockwise. In FIG. 4, each of the first magnet 3_1, the second magnet 3_2, the fourth magnet 3_4, and the third magnet 3_3 moves from 0 toward 2π, that is, toward the right in the figure. .

  At this time, the magnetic field applied to the rotor 1 has components in the z direction and the θ direction. When the thickness of the rotor is sufficiently smaller than the diameter, the θ direction component of the magnetic field does not greatly contribute to the torque generated in the rotor. The z-direction component of the magnetic field is increasing in the + z direction at the position of θ = 0, and the Lorentz current flows clockwise around this position from above, that is, as viewed from the + z direction. Torque acts on the current due to this current, magnetic field, and Lorentz interaction. Further, as the sum of the contributions of the torque around the rotation axis applied to the entire rotor, a torque that tries to rotate following the rotating magnetic field is generated in the rotor. The calculation of the magnitude of this torque will be described in detail later.

Returning to FIG. 1, the sample stage 6 is a flat plate member that fixes the sample container 2 filled with the sample 100, and is arranged such that the upper surface is parallel to the upper surface of the magnet fixing table 7.
As a result, the rotor 1 is moved in the sample 100 inside the sample container 2 when the rotating blade 12, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet rotate. The upper surface of each of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet is parallel to the plane formed.
From the arrangement of the sample table 6, the magnet fixing table 7, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet, the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and Each of the fourth magnets can generate a magnetic field perpendicular to the rotor 1 in the sample container 2 (or a perpendicular magnetic field component).

The motor 4 is a drive mechanism that rotates the magnet fixing base 7 in the direction of the motor shaft 4 a perpendicular to the surface of the magnet fixing base 7, and is fixed so that the motor shaft 4 a is perpendicular to the upper surface of the magnet fixing base 7. Has been.
Further, in plan view, the rotating shaft 11 of the rotor 1 is disposed at a position where the rotor blade 12 of the rotor 1 does not contact the inner wall of the sample container 2 and rotates in contact with the sample 100. A sample container 2 and a motor 4 are arranged.
That is, in plan view. The sample container 2 and the motor 4 are arranged at a position 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, a rotating magnetic field is applied to the rotor blade 12 of the rotor 1 in the sample 100 filled in the sample container 2, and the magnet fixing base 7 is rotated by the motor 4 when rotating around the rotating shaft 11. . Thereby, each of the 1st magnet 3_1, the 2nd magnet 3_2, the 3rd magnet 3_3, and the 4th magnet rotates, and a rotating magnetic field is given to rotary blade 12. 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 application state of the rotating magnetic field to the rotating blade 12.
Here, in plan view, the area of the bottom part inside the sample container 2 is made larger than the area of the rotor blade 12 of the rotor 1. Thereby, even if the rotating shaft 11 of the rotor 1 is deviated from the center of the bottom surface of the sample container 2, it does not come into contact with the side wall inside the sample container 2. However, since the sample container 2 is made large, the amount of the sample 100 filled in the sample container 2 necessary for measuring the viscosity η increases.

For this reason, as shown in FIG. 2, in the present embodiment, a smooth groove (concave portion) 21 t is provided in a part of the bottom surface 21 s of the sample container 2. By providing this groove portion 21t, when the rotor 1 rotates, the lower portion (convex portion) 11e of the rotating shaft 11 of the rotor 1 is arranged by gravity so as to come into contact with the groove portion 21t in the center. .
Further, the upper portion of the rotating shaft 11 of the rotor 1 can be fixed by passing through the rotating shaft holding hole 51 of the rotor holding portion 50, and the position of the rotor 1 and the rotating shaft 11 can be prevented from shifting. . At this time, as described above, the resistance torque generated by friction at the contact portion between the rotating shaft holding hole 51 of the rotor holding portion 50 and the rotating shaft 11 of the rotor 1 is the axial direction of the rotating shaft 11 of the rotor 1. Is oriented in a direction perpendicular to the bottom of the sample container 2, the friction between the rotating shaft 11 and the inner surface of the rotating shaft holding hole 51 of the rotor holding portion 50 is rolling friction. For this reason, since the friction between the rotating shaft 11 and the inner surface of the rotating shaft holding hole 51 of the rotor holding portion 50 is sufficiently smaller than the sliding friction, the contribution of the rotor 1 to the rotational resistance is sufficiently small. Become.

In FIG. 1, the rotating shaft 11 of the rotor 1 has a rod-like shape, and the rotor holding portion 50 has a rotating shaft holding hole 51 that surrounds the rotating shaft 11.
However, it is not necessarily limited to this structure. For example, the rotary shaft 11 is configured as a cylinder, and is configured in a pipe shape having an open top and a hollow hole. And it is good also as a structure which inserts the rod-shaped rotor holding | maintenance part 50 in the open hollow hole of the upper part of a rotating shaft, and rotates the rotor 1. FIG. In this case, in order to reduce mechanical friction generated by the contact between the inner surface of the hollow hole of the rotating shaft 11 and the rotor holding portion 50, lubricating oil may be filled into the hollow hole. Further, as already described in the present embodiment, the lower portion 11e of the rotary shaft 11 has a structure in which the cylinder is closed and has a smooth shape in order to reduce mechanical friction with the groove 21t.

  FIG. 5 is a diagram showing the relationship between the rotational speed ΩM of the motor 4 and each rotational speed ΩD of the rotor 1 in the corresponding standard sample in a plurality of standard samples having different viscosities η. In FIG. 5, the vertical axis represents the rotational difference ΩMD (rotational speed ΩM−rotational speed ΩD) between the rotational speed ΩM and the rotational speed ΩD, and the horizontal axis represents the rotational speed ΩD of the rotor 1. The viscosity η of each standard sample used here is different, for example, 0.5 (mP · s), 1.0 (mP · s), and 2.0 (mP · s). Then, from FIG. 5, a straight line indicating the relationship between the rotational difference ΩMD and the rotational speed ΩD for each standard sample having different viscosities η, that is, the slope ΩD / ΩMD is obtained by the least square 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 direction of the sample container 2 as a position where a mark provided on the surface of the rotor blade 12 of the rotor 1 in the sample 100 of the sample container 2 can be detected. The position of the mark on the surface of the rotor blade 12 (mark 30 in FIG. 2A) is optically detected. That is, the rotation detection sensor 5 emits laser light from the light irradiating unit, makes reflected light from the mark on the upper surface of the rotary blade 12 incident 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 imaging device in which a lens and an imaging device such as a CCD (Charge Coupled Device) are added to a microscope is provided, and the moving state of the mark on the rotary blade 12 of the rotor 1 is enlarged and imaged. A picked-up image is output, and the number of revolutions (that is, the number of revolutions of the mark on the rotary blade 12 and the number of revolutions is 1 when the mark (mark 30 in FIG. 2A) rotates once) is detected from the image processing. May be.

In addition, the upper surface of the rotor blade 12 of the rotor 1 or the lower part 11e of the rotating shaft 11 is irradiated with laser, and reflection and interference pattern changes due to the rotation are optically measured. It is good also as a structure to detect.
Further, a part of the rotor blade 12 of the rotor 1 is replaced with a dielectric, and an electrode pair in which the rotor blade 12 is sandwiched between measurement electrodes is arranged at a position that does not interfere with the rotation of the magnet fixing base 7 as shown in FIG. Configure the capacitor. The rotation detection sensor 5 detects an electrical signal when a dielectric as a mark for detecting rotation (for example, provided at the position of the mark 30 in FIG. 2A) passes between the arranged electrodes. Is output. That is, when the dielectric as a mark passes between the electrodes, the rotation detection unit 81 detects a change in the capacitance of the capacitor constituted by the electrodes, and detects the number of times of the change in the capacitance during a predetermined period (for example, 1 second). In addition, the rotational speed of the rotor 110 may be detected.

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_4 rotates, and the rotating magnetic field is a magnetic field that varies with time. Is formed in a space on the upper surface of the magnet fixing base 7.
Torque is applied to the rotor blades 12 of the rotor 1 by the rotating magnetic field, and the rotor 1 is rotated in the sample 100 in the sample container 2 to perform a constant speed rotation motion. A method for measuring the viscosity η of the sample 100 from the rotation speed in the sample 100 of the rotor 1 will be described below.

The viscosity measurement unit 8 includes a rotation detection unit 81, a viscosity detection 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 based on the detection electric signal supplied from the rotation detection sensor 5, and determines the number of detections per unit time (for example, 1 second) as the number of rotations per unit time (rpm : Revolutions per minute), and output the rotation speed ΩD. In addition, the rotation detection unit 81 does not use the detection electric signal of the rotation detection sensor 5 in detection of the number of rotations of the rotor 1 but uses an image picked up by the image pickup device. The mark of the rotor blade 12 of the rotor 1 may be detected from the image by image processing, and the rotational 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 configured by the electrode pair based on the detection electric signal, and detects the number of times of the capacitance change in a predetermined period (for example, 1 second). Alternatively, the rotational speed ΩD of the rotor 1 may be detected.

  As in the case of the standard sample described above, the viscosity detector 82 obtains the slope ΩD / ΩMD (= ΩM−ΩD) of the sample 108 and obtains the reciprocal ΩMD / ΩD of this slope. 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 number of rotations is changed. 81. The rotation detection unit 81 inputs the rotation speed ΩD of the rotor 1 in the sample 100 in the sample container 2 at the rotation speed ΩM from the rotation detection sensor 5 every time a control signal is supplied from the viscosity detection unit 82. Then, the rotation detection unit 81 outputs the detected rotation speed ΩD to the viscosity detection unit 82 corresponding to the control signal.

  Then, the viscosity detector 82 reads the viscosity η (mP · 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). Is output as the viscosity η (mP · s). 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 inverse of the slope ΩMD / ΩD for this empirical formula. The viscosity η (mP · s) of the sample 100 may be calculated and obtained.

  The rotating magnetic field control unit 83 performs rotation control on the motor 4 so that the motor 4 rotates at the set number of rotations. Thereby, the magnet fixing base 7 rotates via the motor shaft 4a, and the 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 rotate and rotate. A rotating magnetic field for rotating the child 1 in the sample 100 at a constant speed is generated.

The standard data storage unit 84 stores a viscosity detection table indicating the correspondence between the viscosity η (mP · s) obtained from the table in FIG. 5 and the reciprocal of the slope ΩMD / ΩD.
This viscosity detection table is created as follows. As described with reference to FIG. 5, 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, and the rotor 1 is placed in the standard sample. When the motor 4 is rotated at the rotation speed ΩM, 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 is measured for the standard sample with respect to a plurality of standard samples having different viscosity η (samples whose viscosity η is known in advance).
Further, instead of the viscosity detection table, an empirical formula indicating the correspondence between the viscosity η (mP · 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 measurement unit 8.

Next, a method for applying rotational torque to the rotor blades 12 of the rotor 1 will be described. In FIG. 1, a magnetic field perpendicular to a certain reference plane (a plane including the rotor blades 12) by the N pole of the first magnet 3_1 and the fourth magnet 3_4 and the S pole of the second magnet 3_2 and the fourth magnet 3_3. Will occur. This reference plane is a reference two-dimensional plane composed of an x-axis and a y-axis, and the axial direction of the rotary shaft 11 of the rotor blade 12 of the rotor 1 rotating in this two-dimensional plane is the z-axis.
Hereinafter, the z-axis component of the magnetic field at the reference two-dimensional plane or a point (x, y, z) in the vicinity thereof is shown as Bz (x, y).

As described above, since the magnetic field is perpendicular to the reference two-dimensional plane, it is assumed that the magnetic field does not depend on the z axis. However, depending on the z axis, there is no problem in the following description. In addition, if there is a magnetic field component perpendicular to the reference two-dimensional plane, the rotational torque applied to the rotor blades 12 of the rotor 1 even if there are other magnetic field components that are not perpendicular to the reference two-dimensional plane. It does not interfere with giving.
In the following description, the rotor blade 12 is made of metal, and the rotational torque applied to the rotor blade 12 is calculated. Also, for convenience, orthogonal coordinates are initially adopted, the vertical upper direction of the rotor blade 12 is set to the + z direction, the rotor blade 12 is raised in the xy plane, and the center of the rotor blade 12 (the rotary shaft 11 and the rotor blade 12 (The intersection of Further, the rotating magnetic field generated by the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 as the magnet fixing base 7 rotates is expressed by the following equation (1).

In the above equation (1), r represents the distance from the rotation axis, B _z represents the magnetic field in the z-axis direction, B (r) represents the magnetic field in the rotational radius direction, ω represents the rotational angular velocity, and t is Time indicates n, 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 there are two sets of magnets having N and S poles as the magnetic poles facing the sample stage 6.
The electric field E generated by the magnetic field B that varies with time 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 a magnetic field B _z having only a z-direction component, but the following argument holds even if there are components other than the z-axis direction.
The current vector i flowing through the conductive disk-shaped rotor blade 12 in the rotor 1 is i = σE, where σ is the conductivity. i and E are vectors. Since the divergence is “0” for the current vector i, div i = 0. Therefore, for the electric field E, there exists a vortex potential φ that satisfies the following expression (3).

In the above equation (3), E _x represents an electric field in the x-axis direction in the two-dimensional coordinate system, and E _y represents an electric field in the y-axis direction in the two-dimensional coordinate system.
The above equation (3) is substituted into equation (2) to obtain the following equation (4).

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

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

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

  From the above equation (6), the following equation (7) is obtained.

In the above equation (7), J _n (kr) represents a first-type Bessel function, k represents an integration variable for executing the integration of equation (7), r represents a rotation radius, and ω represents a rotation angular velocity. , T represents time, and θ represents the rotation angle of the magnet fixing base 7.
In the above equation (7), the coefficient A (k) is the Hankel transform coefficient of B (r) and is expressed by the following equation (8).

  The following description moves 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 respectively obtained from the electric field Ex and the electric field Ey obtained by the expression (3), they can be expressed as the following expression (9). In the equation (9), θ represents the rotation angle of the magnet fixing base 7, and r represents the rotation radius.

In the above equation (9), when considering the Lorentz interaction between the electric field and the magnetic field, the total integral of the radial components of the Lorentz force is obviously zero due to symmetry.
The radial component is given by F _θ = σE _r B _z . This radial component is expressed by the following equation (10) by the equations (7) and (9). In equation (10), ω represents the rotational angular velocity, θ represents the rotational angle of the magnet fixing base 7, n represents the number of magnet pairs, and the coefficient A (k) represents the Hankel transformation coefficient of B (r). J _n (kr) represents the first type Bessel function, k represents an integration variable when executing the integration of Expression (7), and r represents the radius of rotation.

In the above equation (10), for the sake of simplicity, the radial distribution of the magnetic field can be approximated by a Bessel function. That is, when B (r) = B ₀ J _n (kr), the torque T given to the rotating blade 12 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 represents the number of magnet pairs, ω represents the rotational angular velocity, B ₀ represents an integration variable when performing the integration of equation (7), and J _n (kr) represents the first A seed Bessel function is shown.

As described above, it has been found that the torque T acts on the rotor blade 12 of the rotor 1 by the rotating magnetic field. In the actual viscosity / elasticity measuring apparatus, the rotor 1 rotates in the sample 100 by the torque T acting on the rotor blade 12, so that the rotational speed ΩM of the rotating magnetic field is the same as the rotational speed ΩM of the magnetic field. The rotation speed difference ΩM−ΩD, which is the difference from the rotation speed of the rotor blade 12 of the child 1, is replaced.
As a result, the eddy current generated in the conductor of the rotor blade 12 of the rotor 1 receives the rotation torque (torque T), whereby the rotation torque T is applied to the rotor blade 12 of the rotor 1. . As a result of the rotation torque being applied to the rotor blades 12 of the rotor 1, the rotor 1 rotates in the direction in which the rotation torque T is applied in the sample 100.

In addition, a viscous resistance torque due to shear flow corresponding to the viscosity η of the sample 100 is applied to the rotating blade 12 as the rotating blade 12 rotates. Due to this viscous resistance torque, the rotational speed ΩD of the rotor 1 does not reach the rotational speed ΩM of the magnetic field by an amount proportional to the viscous resistance torque.
Therefore, the magnitude of the rotational torque T applied to the rotor blade 12 of the rotor 1 is proportional to the difference between the rotational speed ΩM of the rotating magnetic field (similar to the rotational speed of the motor 4) and the rotational speed ΩD of the rotor 1. Will do. That is, when the rotational speed ΩD of the rotor 1 becomes constant, the constant rotational speed ΩD has an inversely proportional relationship with the viscosity η of the sample 100.

As described above, the rotational torque T applied to the rotor blade 12 of the rotor 1, the rotational speed ΩD of the rotor 1 rotating in the sample 100, the radius r of the rotor 1, the rotor blade 12 and the sample container It can be seen that the viscosity η of the sample 100 can be determined by the thickness between the bottom of the inner surface of the main body 21 and the thickness between the rotary blade 12 and the sample container lid 22.
Here, in the measurement of the viscosity η of the sample 100, the rotational torque T applied to the rotor blades 12 of the rotor 1 is as shown in FIG. 5 described above using a standard sample whose viscosity η is known in advance. Further, it is obtained as a function of a rotational speed difference ΩMD between the rotational speed ΩM of the rotating magnetic field and the rotational speed ΩD of the rotor 1.

Further, when the sample 100 is filled only in the space below the rotary blade 12, that is, when the sample 100 is filled only between the bottom of the inner surface of the sample container body 21 and the lower surface of the rotary blade 12, the sample is 12 contacts only the lower surface.
Therefore, when creating the viscosity detection table shown in FIG. 5, it is necessary to measure the standard sample under the same conditions.
If the density of the sample 100 for measuring the viscosity η is known in advance, an appropriate sample having a uniform depth can be obtained when the sample 100 is inserted into the sample container 2 having a common size corresponding to the density of the sample 100. Weigh 100 with a balance. By this processing, the depth of the sample 100 put into the sample container 2 at the time of measurement can be made uniform for each sample 100 having different densities.

Here, the accuracy of the viscosity measurement in the viscosity / elasticity measuring apparatus of the present embodiment will be described. In the viscosity / elasticity measuring apparatus according to the present embodiment, a known torque T is applied remotely to the rotor blade 12 of the rotor 1 by a time-varying magnetic field (rotating magnetic field having a rotational speed of ΩM), and the rotational speed ΩD is obtained. By detecting, the viscosity η of the sample 100 as the target substance is measured.
The torque T applied to the rotor blades 12 of the rotor 1 may be obtained from the above formula (11) from the magnitude of the applied magnetic field. Alternatively, the measurement may be performed in advance using a standard sample having a known viscosity η. The determination accuracy of the magnitude of the torque T obtained from this can be arbitrarily improved in principle, and can actually be determined with an accuracy of 0.1% or more.

On the other hand, the factors that determine the rotational speed ΩD of the rotor 1 include the lower part 11 e of the rotating shaft 11 of the rotor 1 and the bottom surface 21 s inside the sample container body 21 in addition to the viscosity η of the sample 100 to be detected. Rotational torque _Tf due to mechanical friction at the contact portion. It has been verified theoretically and experimentally that the rotational torque T _f is of the level indicated by the following equation (12).

  In the above equation (12), M represents the weight of the rotor 1, ρ represents the specific gravity of the sample 100, V represents the volume of the portion of the rotor 1 that is immersed in the sample 100, g represents the gravitational acceleration, μ represents a dynamic friction coefficient between the lower portion 11e of the rotating shaft 11 and the bottom surface 21s of the sample container body 21, and Rc represents a contact radius of a contact portion between the lower portion 11e of the rotating shaft 11 of the rotor 1 and the bottom surface 21s of the sample container body 21. Is shown.

In addition, the disk-shaped rotating blade 12 having a radius R in the rotor 1 makes the rotation angle ω on the upper surface (the surface in contact with the rotating blade 12) the lower surface (sample container) with respect to the sample 100 having a thickness (depth) d. A torque T _VIS necessary for applying a strain at a rotational angular velocity of 0 on the bottom surface 21s of the main body 21 is calculated by the following equation (13).

  In the above equation (13), Rc represents the contact radius of the contact portion with the container bottom at the bottom of the rotor, M represents the weight of the rotor 1, and V represents the volume of the portion of the rotor 1 that is immersed in the sample 100. Ρ indicates the specific gravity of the sample 100, g indicates the gravitational acceleration, R indicates the radius of rotation of the rotor 1, η indicates the viscosity of the sample 100 as the detection target substance, and μ indicates the rotation of the rotor 1. The dynamic friction coefficient between the lower part 11e of the shaft 11 and the bottom surface 21s of the sample container main body 21 is indicated, and d indicates the thickness of the sample 100 sandwiched between the rotor blade 12 of the rotor 1 and the bottom surface 21s of the sample container main body 21. .

Also, α is the required viscosity / elasticity measurement accuracy. 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, if the following equation (14) is established, the required measurement accuracy α is obtained. be able to. The torque T _VIS due to the viscosity of the sample 100 dominates the torque T _f of mechanical friction due to the contact between the rotor 1 and the bottom surface 21s of the sample container body 21 by a factor of 1 / α or more, thereby achieving an accuracy α. Viscosity measurement is possible.

The measurement accuracy α is about 10% in the conventional method, but more preferably about 1%. Furthermore, it is desired that about 0.1%, which is difficult accuracy with the conventional method, is obtained.
As described above, according to the present embodiment, the amount of the sample 100 that 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 arranged in the lower direction of the sample stage 6 on which the sample container 2 is disposed. It is possible to reduce the size of the viscosity / elasticity measuring apparatus as compared with the conventional one.

  Further, in FIG. 1, the combination of the first magnet 3_1, the second magnet 3_2, the third magnet 3_3, and the fourth magnet 3_4 is used as the magnet that generates the rotating magnetic field. In this case, the rotating magnetic field is generated by two sets of combinations in which two N poles and two S poles are alternately arranged in a plan view. On the other hand, according to the equation (11), the number of magnet sets that give torque to the rotor blades 12 of the rotor 1 may be any one or more, for example, two square magnets in plan view, You may arrange | position so that a south pole and a north pole may become alternate.

In addition, the above-described magnet fixing base 7 is rotated, and a rotating magnetic field is generated 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_4. It is good also as a structure.
FIG. 6 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. A winding CL1 is wound around the teeth 10a and 10c in different winding directions, and similarly, a winding CL2 is wound around the teeth 10b and 10d in different winding directions to constitute an electromagnet.
Instead of generating a rotating magnetic field from the magnetic fields emitted from 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, by rotating the magnet fixing base 7 by the motor 4 in FIG. You may generate | occur | produce a rotating magnetic field using the structure of the electromagnet shown in FIG. 6 mentioned above.

That is, a current is passed through the windings CL1 and CL2, a magnetic field perpendicular to the reference two-dimensional plane is generated, the direction of the flowing current is periodically changed, and a magnetic field perpendicular to the reference two-dimensional plane is generated. 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 different polarity from the other adjacent electromagnets. When the electromagnet is driven, the rotating magnetic field may be generated by changing the polarity of each electromagnet with time.
In this case, the rotating magnetic field control unit 83 causes a current to flow through the windings CL1 and CL2 in the electromagnet of FIG. 6, and periodically changes the direction of the flowing current to generate a rotating magnetic field.
As in the case where a magnet is already used, torque is applied to the rotor blade 12 of the rotor 1 by this rotating magnetic field, and the rotor blade 12 rotates around the rotating shaft 11 in the sample 100. Accordingly, the viscosity η of the sample 100 is obtained.

In addition, the rotating magnetic field control unit 83 may arbitrarily change the rotation period and the rotation direction of the rotating magnetic field to be applied to the rotor blade 12 of the rotor 1.
For example, by periodically sweeping the rotation direction of the rotating magnetic field and the rotation speed, a rotational torque that periodically changes can be applied to the rotor 1.

FIG. 7 is a schematic diagram illustrating another configuration of the sample container filled with the sample 100. According to the form of FIG. 7, the cross sections of the sample container main body 201 and the sample container lid 202 constituting the sample container 200 are triangular. That is, the cross section of each of the sample container main body 201 and the sample container lid 202 is formed so that the thickness decreases from the center to the outer periphery.
As a result, the thickness of the sample 100 sandwiched between the rotary blade 12 and each of the bottom surface 201s of the sample container main body 201 and the sample container lid 202 increases in proportion to the distance from the rotating shaft 11 of the rotor 1. . Thereby, uniform deformation of the shear rate can be realized everywhere in the sample 100 filled in the sample container 200. Therefore, the configuration of the sample container 200 is effective for measuring the viscosity and elasticity of a non-Newtonian fluid whose viscosity value varies depending on the shear rate. The mark 19 is a mark for detecting the rotation of the rotary shaft 11.

FIG. 8 is a schematic view showing another configuration of the sample container filled with the rotor and the sample 100. In FIG. 8, the rotor 401 includes a rotating blade 412 and a convex portion 411 as a rotating shaft of the rotating blade.
The sample container 420 includes a sample container main body 421 and a sample container lid 422. The sample 100 is filled in an internal space formed from each of the sample container main body 421 and the sample container lid 422. The entire bottom surface 421s of the sample container main body 421 is flat. That is, the bottom surface 421s of the sample container main body 421 in FIG. 9 is not provided with a groove like the groove portion 21t into which the rotating shaft 11 of the rotor 1 shown in FIG. 2 is inserted.

In the rotor 401, the rotor blade 412 is a disk-shaped member, and a convex portion 411 is provided at the center of the lower surface 412s facing the bottom surface 421s of the sample container main body 421.
The bottom portion 411e of the convex portion 411 of the rotor 401 that contacts the bottom surface 421s of the sample container main body 421 is the lowest point of the convex portion 411, and is formed in a smooth shape to reduce mechanical friction on the contact surface. ing. Further, the radius of curvature of the region where the bottom 411e of the convex portion 411 contacts the bottom surface 421s of the sample container main body 421 is RT.
Further, in the state of being immersed in the sample 100, the distance between the center of gravity position RG in consideration of the buoyancy of the rotor 401 and the bottom 411e of the convex portion 411 of the rotor 401 is h. The convex portion 411 of the rotor 401 is configured so that the condition of RT <h is satisfied.

When the above condition is satisfied, the rotor 401 is configured such that the rotor wing 412 is in contact with the bottom surface 421s of the sample container body 421 while the bottom 411e of the convex portion 411 is in contact with the bottom surface 421s (plane) of the sample container body 421. The posture to keep level is stabilized. That is, the rotor blade 412 and the bottom surface 421 s of the sample container main body 421 are kept in parallel and in a horizontal plane only by arranging the rotor 401 while being immersed in the sample 100.
For this reason, it is not necessary to finely adjust the posture of the rotor 401, the shear rate in the entire sample 100 can be made stable and uniform, and the measurement of viscosity and elasticity can be realized with high accuracy. Further, it is not necessary to provide the rotation shaft holding hole 51 of the rotor holding portion 50 for stabilizing the rotation of the rotor 1 by inserting the rotation shaft 11 in the configuration of FIG. 2, and it is possible to reduce unnecessary mechanical contact. It is possible to improve the measurement accuracy. Moreover, since it is not necessary to provide the rotor holding | maintenance part 50, the structure of a viscosity and elasticity measuring apparatus can be simplified.

FIG. 9 is a schematic diagram illustrating another configuration of the rotor. In FIG. 9, the sample container 20 has the same configuration as in FIG. The rotor 1A has a configuration in which a member 11m is provided on the upper portion 11t of the rotating shaft 11 of the rotor 1 of FIG. This member 11m is formed of a material having magnetism.
Further, a rotor holding portion 600 is provided on the upper portion of the rotating shaft 11 in the axial direction so as to face the member 11m with a gap of a predetermined distance. The rotor holding part 600 is formed of a magnet. Therefore, the rotor holding | maintenance part 600 applies the force which pulls up the member 11m, ie, the rotor 1A upward. Here, the rotor holding part 600 and the groove part 21t formed in the bottom surface 21s of the sample container main body 21 are provided at positions overlapping in plan view. As a result, the rotating shaft 11 is always kept in the vertical direction because a force to be pulled upward is exerted. Moreover, the lower part 11e of the rotating shaft 11 and the inner surface of the groove part 21t formed in the bottom face 21s of the sample container main body 21 are each formed smoothly so that mechanical friction in contact is reduced.

The rotor 1A maintains the rotating blade 12 horizontal with respect to the bottom surface 21s of the sample container body 21 in a state where the lower portion 11e of the rotation shaft 11 is in contact with the inner surface of the groove portion 21t of the bottom surface 21s of the sample container body 21. Is stable. That is, the rotor blade 12 and the bottom surface 21 s of the sample container main body 21 are kept in parallel and in a horizontal plane only by disposing the rotor 1 </ b> A in the sample 100.
Therefore, in order to maintain the posture of the rotor 1A, it is not necessary to provide the rotation shaft holding hole 51 of the rotor holding portion 50 that inserts the rotation shaft 11 in the configuration of FIG. 2 and stabilizes the rotation of the rotor 1. As a result, it is possible to reduce excessive mechanical contact with the rotor 1A, and it is possible to realize measurement of viscosity and elasticity with high accuracy. Moreover, since it is not necessary to provide the rotor holding | maintenance part 50, the structure of a viscosity and elasticity measuring apparatus can be simplified.

Next, the measurement of elasticity using the viscosity / elasticity measuring apparatus according to the present embodiment will be described. This will be described with reference to the viscosity / elasticity measuring apparatus having the configuration shown in FIGS.
According to the present embodiment, instead of obtaining viscosity like a liquid, for a substance having an elastic modulus such as gel or rubber, or a substance such as a polymer solution in which an elastic modulus is generated by relaxation of viscosity, The viscosity and elastic modulus can be measured simultaneously by displacement from a stationary position when a constant torque is applied.

Here, the elastic modulus is a so-called 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. For this reason, after the rotation starts, the rotor 1 stops rotating at a rotation angle θ that balances the elastic force proportional to the spring constant of the sample and the rotational torque generated by the rotating magnetic field. By rotating the magnet fixing base 7 counterclockwise, the counterclockwise rotational torque is applied to the rotor 1 in the sample 100 as described above.

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

FIG. 10 is a diagram showing the relationship between the rotational speed ΩM (that is, rotational torque) of the motor 4 and the rotational angle θ at which the rotor 1 stops. In FIG. 10, the horizontal axis indicates the rotational speed ΩM of the motor 4, and the vertical axis indicates the rotation angle θ at which the rotor 1 stops.
That is, in the case of the viscosity / elasticity measuring apparatus shown in FIGS. 1 and 2, the magnet fixing base 7 is rotated by the motor 4, so that the first magnet 3_1, the second magnet 3_2, which are arranged on the magnet fixing base 7, Each 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 rotating magnetic field control unit 83 changes the rotation speed of the motor 4 according to preset steps, obtains the rotation angle θ for each rotation speed, and obtains the relationship between the rotation speed ΩM and the rotation angle θ. The graph shown in FIG. Here, the above-described processing is performed on a plurality of standard samples whose elasticity is known in advance in order to create standard data used for the elasticity measurement of the sample 100 whose elasticity is unknown, similarly to the viscosity. Similarly to the creation of the viscosity standard data, the standard sample is put in the sample container 2 and the rotation angle θ described above is measured.

FIG. 11 is a diagram illustrating the relationship between elasticity and the ratio of the rotation speed and the rotation angle. In FIG. 13, the horizontal axis indicates elasticity (elastic modulus: Pa), and the vertical axis indicates a 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 between the rotational speed ΩM and the rotational 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 rotation 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 it to the viscosity detection unit 82.
The viscosity detection unit 82 obtains a proportional coefficient between the rotation speed ΩM and the rotation angle θ supplied from the rotation detection unit 81, reads elasticity data corresponding to the proportional coefficient from the standard data in the standard data storage unit 84, The read data is output as the elasticity of the sample 100.

Moreover, it is also possible to measure elasticity and viscosity simultaneously by changing the rotational torque applied to the rotor blade 12 of the rotor 1 with time. In this case, the magnet for generating the rotating magnetic field is constituted by the electromagnet shown in FIG.
For example, after applying an exciting current to the electromagnet and applying a predetermined rotational torque to the rotor blade 12 of the rotor 1, the application of this exciting current is stopped, and the rotating state of the rotor 1 after stopping Observe.

At this time, the rotor 1 causes rotational vibration according to the elasticity of the sample 100 with which the rotor 1 is in contact. Here, the period and vibration time of the rotational vibration are proportional to the elasticity, and the attenuation rate of the amplitude of the rotational vibration is proportional to the viscosity.
Therefore, for each of a plurality of standard samples whose viscosity and elasticity are known in advance, a rotating magnetic field is applied to the rotor blade 12 of the rotor 1 with the attenuation rate, period and vibration time of the rotation vibration. The standard data is prepared and stored in the standard data storage unit 84 in advance.

Next, when measuring a substance to be measured having actual unknown viscosity and elasticity, the viscosity detector 82 determines the amplitude attenuation rate, period, and vibration time of the sample 100 that is the substance to be measured as a rotor. 1, the viscosity corresponding to the measured attenuation rate of the amplitude and the elasticity corresponding to the period and the vibration time are read from the standard data in the standard data storage unit 84, respectively.
Then, the viscosity detector 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 this embodiment, the viscosity and elasticity of the sample 100 can be simultaneously measured at the same time.

Further, by periodically sweeping the rotation direction of the rotating magnetic field applied to the rotor blade 12 of the rotor 1 and the rotational torque (the rotational speed ΩM of the motor 4), the rotor blade 12 of the rotor 1 is periodically moved. Can be applied.
The amplitude and phase of the rotational vibration of the rotor 1 are observed from the captured image obtained by imaging the mark 30 of the rotor 12 while changing the period of sweeping the rotational direction and the rotational torque. It becomes possible to measure elasticity independently.
That is, the observation of this rotational vibration is to detect the damped vibration after the magnetic field is erased as a frequency spectrum, and 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 apparatus (mechanical property measuring apparatus) shown in FIG. 1 will be described.
The sample container main body 21 used was a glass petri dish having an inner diameter of 40 mm and an inner side wall height of 10 mm. Then, 5 mL of the sample 100 as the substance to be measured was placed in the sample container main body 21, and then 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 standard samples whose viscosity is known in advance, three types of 0.5 (mPa · s), 1.0 (mPa · s), and 2.0 (mPa · s) were used as shown in FIG. .

  Then, rotational torque was applied to the rotor blades 12 of the rotor 1 on the surface of the standard sample to rotate the rotor 1. In this case, the lower surface of the rotary blade 12 is in contact with the sample 100. Here, the rotating blade 12 was provided with an aluminum sphere having a diameter of 2 mm as a lower portion 11 e with respect to the lower end of the rotating shaft 11, on an aluminum plate having a diameter of 28 mm and a thickness of 0.1 mm. The rotating shaft 11 was a glass tube having a diameter of 1.6 mm and a length of 30 mm.

Next, the rotating magnetic field control unit 83 drives the motor 4 to rotate the magnet fixing base 7.
As a result, the magnetic fields perpendicular to the rotor blades 12 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_4 are converted into the first magnet 3_1, the second magnet 3_2, and the third magnet. A rotating magnetic field is applied to the rotor blades 12 of the rotor 1 by rotating the magnet 3_3 and the fourth magnet 3_4. Due to this rotating magnetic field, the rotating blade 12 of the rotor 1 is applied with a rotating torque and rotates in the same direction as the rotating direction of the applied rotating magnetic field.
Then, for example, the rotation detection unit 81 stores a moving image of the mark 30 of the rotor blade 12 of the rotor 1 that is imaged by the rotation detection sensor (imaging device) as a captured image in a storage unit within itself, and the image The rotation period of the mark 30 is obtained by processing, and the rotation speed of the rotor 1 is obtained from the rotation period of the mark.

Each time the rotational speed ΩM of the motor 4 is changed, the rotational speed ΩD of the corresponding rotor 1 is obtained. As shown in FIG. 5, the rotational speed ΩD of the rotor 1 and the rotational speed ΩM for each standard sample having different viscosities. And the corresponding relationship with the difference of ΩM.
In FIG. 5, the relationship indicating the relationship between the rotational speed ΩD of the rotor 1 of each standard sample and the difference between the rotational speeds ΩM and ΩM is a straight line. For this reason, FIG. 5 shows that the viscosity can be obtained only from the relationship between the rotational 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.

Note that a program for realizing the function of the viscosity / elasticity measuring apparatus 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. Thus, processing for obtaining the viscosity of the sample may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.
The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program 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 the 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. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1,1A ... Rotor 2,200,420 ... Sample container 4 ... Motor 4a ... Motor shaft 5 ... Rotation sensor 6 ... Sample stand 7 ... Magnet fixing stand 8 ... Viscosity measuring part 11 ... Rotating shaft 11m ... Member 11t ... Lower part 12 ... Rotary blades 21, 201, 421 ... Sample container body 21s, 421s ... Bottom surface 21t ... Groove part 22,202,422 ... Sample container lid 22h ... Through hole 30 ... Mark 3_1 ... First electromagnet 3_2 ... Second electromagnet 3_3 ... Third Electromagnet 3_4 ... 4th electromagnet 50, 600 ... Rotor holding part 51 ... Rotating shaft holding hole 81 ... Rotation detecting part 82 ... Viscosity detecting part 83 ... Rotating magnetic field control part 84 ... Standard data storage part 85 ... Device control part 411 ... Convex Part

Claims (9)

Part or the whole is made of a conductive material, and the disk has a frame shape in which the surface of the disk is fixed perpendicular to the rotation axis, and the shaft tip of the rotation axis is smooth. A rotor formed in a convex shape;
A sample container in which a detection target substance to be detected for viscosity is put, and the rotor is arranged in a state where the surface of the disc is in contact with the detection target substance;
A magnet disposed around the sample container and applying a magnetic field to the rotor;
Driving the dynamic magnetic field application magnet to apply a time-varying magnetic field to the rotor, inducing an induced current in the disk of the rotor, and the induced current and the magnetic field applied to the rotor A rotation control unit for rotating the rotor by rotating torque by Lorentz interaction;
A rotation detector for detecting the rotation speed of the rotor;
A viscoelasticity detection unit that detects the viscosity and elasticity of the detection target substance in contact with the rotor according to the rotational speed of the rotor;
A viscosity / elasticity measuring apparatus, wherein the radius of the disk of the rotor is determined by the following equation.

R _c : Contact radius of the contact portion with the bottom of the sample container at the lower part of the rotor M: Weight of the rotor V: Volume of the portion immersed in the sample of the rotor ρ: Specific gravity of the sample g: Gravity acceleration R: Rotation of the rotor Blade radius η: Viscosity of the substance to be detected μ: Dynamic friction coefficient between the lower part of the rotor and the bottom of the sample container d: Thickness of the sample sandwiched between the rotor and the sample container α: Measurement accuracy of required viscosity and elasticity 2. The viscosity / elasticity measuring apparatus according to claim 1, wherein a convex portion of a tip portion of the rotating shaft of the rotor is in contact with a bottom portion of an inner surface of the sample container. A storage unit for storing standard data obtained by measuring in advance 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;
The viscosity / elasticity of the detection target substance is obtained by comparing the standard data with the relationship between the rotational torque and the rotation speed of the detection target substance detected by the viscosity detection unit. Item 3. The viscosity / elasticity measuring apparatus according to Item 2. The rotor is marked,
The viscosity / elasticity measuring apparatus according to any one of claims 1 to 3, wherein the rotation detecting unit detects the rotation number of the rotor by detecting the rotation of the mark. The rotational speed of the rotor is detected by irradiating the disk of the rotor with a laser and optically measuring a change in reflected light or an interference pattern. The viscosity / elasticity measuring apparatus according to claim 3. 6. The viscosity according to claim 1, wherein the bottom of the inner surface of the sample container in contact with the rotor is formed in a smooth flat surface or a smooth curved concave shape. Elasticity measuring device. A lid for closing the upper opening of the sample container is provided for the sample container,
The rotating shaft of the rotor is rotatably provided between the bottom of the inner surface of the sample container filled with the detection target substance and the inner surface of the lid. The viscosity / elasticity measuring apparatus according to claim 6. The space inside the sample container is formed so as to be thicker in proportion to the distance from the rotation axis with respect to the diameter direction of the disk of the rotor. Item 8. The viscosity / elasticity measuring device according to any one of Items 7 to 9. A sample container is filled with a detection target substance whose viscosity and elasticity are to be detected, and a part or the whole of the detection target substance is made of a conductive material. A rotor having a frame shape fixed vertically to the rotation shaft and having a smooth convex shape at the tip of the rotation shaft is disposed so that the detection target substance contacts the surface of the disk. Process,
A dynamic magnetic field application magnet arranged around the sample container is driven, a time-varying magnetic field is applied to the rotor, an induced current is induced in the disk of the rotor, the induced current and the induced current A process of rotating the rotor by applying a rotational torque by Lorentz interaction with the magnetic field applied to the rotor;
Detecting the rotational speed of the rotor;
A viscosity detecting process for detecting the viscosity / elasticity of the detection target material in contact with the rotor according to the rotational speed, and the radius of the disk of the rotor is determined by the following equation: Elasticity measurement method.

R _c : Contact radius of the contact portion with the bottom of the sample container at the lower part of the rotor M: Weight of the rotor V: Volume of the portion immersed in the sample of the rotor ρ: Specific gravity of the sample g: Gravity acceleration R: Rotation of the rotor Blade radius η: Viscosity of the substance to be detected μ: Dynamic friction coefficient between the lower part of the rotor and the bottom of the sample container d: Thickness of the sample sandwiched between the rotor and the sample container α: Measurement accuracy of required viscosity and elasticity

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