JP2000028508A - Viscometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a potable viscometer which has a simple structure is easily handleable, while securing the measurement accuracy of viscosity over a wide range. SOLUTION: A viscometer 1 is structured to have a rotator 5 rotating while receiving viscosity resistance, a driving shaft 8 connecting the rotator 5 to its prime mover part 7, a torque detection part 10 for detecting a driving torque of the driving shaft 8, where the prime mover part 7 is provided with a motor, and the driving shaft 8 is provided with the torque detection part 10 with a torque sensor and a magnetic shield member 11 intercepting magnetism received from the prime mover part 7 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscometer for measuring the viscosity of a fluid, and more particularly to a portable device having a simple structure and easy handling while ensuring a wide range of viscosity measurement accuracy. For a suitable viscometer.

[0002]

2. Description of the Related Art A viscometer includes a rotor that rotates while receiving viscous resistance, a drive shaft that rotationally drives the rotor, and a torque detector that detects a drive torque of the drive shaft. In contrast, the viscosity of the fluid acting on the rotor is calculated.

[0003]

However, the conventional viscometer is constructed by elastically supporting the rotating part in order to secure the detection accuracy of the minute torque acting on the rotor, so that the viscometer can be accurately positioned on the horizontal part. In order to cover a wide range and ensure the accuracy of viscosity detection, the measurement is performed by combining the main body of the measuring instrument and various rotors according to the size of the viscosity to be detected. This necessitates not only the disadvantage of cost due to the complicated configuration but also the maintenance of measurement conditions and complicated handling.

SUMMARY OF THE INVENTION An object of the present invention is to provide a viscometer which has a simple structure and is easy to handle and suitable for carrying, while ensuring a wide range of measurement accuracy for viscosity.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, a rotor that rotates while receiving viscous resistance, a drive shaft connecting the rotor and its driving unit, and a drive shaft for the drive shaft A torque detector that detects torque, and in a viscometer that calculates the viscosity of the fluid acting on the rotor in comparison with the detected torque, an electric motor is arranged in the driving unit, and
The drive shaft is provided with a torque detection unit using a magnetostrictive torque sensor and a magnetic shield member that blocks magnetism received from the driving unit side.

In the viscometer, since the electric motor, the magnetostrictive torque sensor, and the magnetic shield member are provided between the electric motor and the magnetostrictive torque sensor, even if the DC motor is arranged in the driving part, the viscometer can be controlled by the magnetostrictive torque sensor without being affected by its magnetism. Since a wide range of torque detection accuracy can be ensured, high-precision viscosity measurement over a wide viscosity range is possible.

[0007] A magnetic coupling is provided between the drive shaft and the rotor for non-contact rotation of the rotor to define a gap between the rotor and the torque detector. By providing a magnetic shield member that blocks the magnetism caused by the magnetic coupling between the torque detection unit and the inspection fluid, it is possible to protect the torque detecting unit to prevent intrusion of foreign substances, and the magnetic shield member is used to protect the magnetic field of the magnetic coupling. Therefore, the handleability can be secured without impairing the torque detection accuracy. By forming the side of the magnetostrictive torque sensor with a magnetic shield member, the influence can be suppressed even in a magnetic environment, and the detection accuracy can be secured. The ring-shaped converter of the magnetostrictive torque sensor is formed by coating or plating a ferromagnetic material on the outer peripheral surface of the drive shaft. It is possible to reduce the size of the entire configuration and improve the handling while ensuring the torque detection accuracy.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the technical concept according to the present invention is applied will be described below. FIG. 1 is an internal structural view of a viscometer of the present invention due to partial breakage. Viscometer 1
Is a measuring cylinder 3 having a window 3a at the tip of a substantially cylindrical body frame 2.
The measuring cylinder 3 includes a detachable mounting seat 4 and a rotor 5 that rotates to receive viscous resistance in the measuring cylinder 3. The upper end of the main body frame 2 is a control unit 6 including an operation switch and a display unit. 6a indicates a connector for data output.

A driving unit 7 of a small DC motor with a speed reducer is provided in the main body frame 2, and a lower end of a driving shaft 8 extending from the driving unit 7 is connected to a lower end of a driving shaft 8 via a magnet coupling 9 for non-contact rotation. The rotor 5 is connected. Also,
A torque detector 10 is provided at an intermediate portion of the drive shaft 8. 8a shows a shaft coupling.

The magnet coupling 9 includes a magnet 9a fixed to the lower end of the drive shaft 8, a fixed shaft 9b defining a space between the rotor 5 and the torque detector 10, and extending downward. And a magnet 5a embedded in the rotor 5 provided in the above. A thrust bearing 9c is provided at the lower end of the fixed shaft 9b, and the magnet 5a on the rotor 5 side is opposed to the magnet 9a on the drive shaft side via the thrust bearing 9c. The driving force is transmitted while being held.

The torque detecting section 10 has a ring-shaped converting section 10.
This is constituted by a magnetostrictive torque sensor having a. The ring-shaped converter 10a has a small diameter formed on the outer peripheral surface of the drive shaft 8 by painting or plating a ferromagnetic material. The converter 10a is magnetized in the circumferential direction by a rotational magnetizing process or the like, so that when it receives a torsional torque, the direction of the magnetization is inclined according to the magnitude of the strain deformation, and the converter 10a
Generates a magnetic field around it.

An amorphous wire 10b for magnetic detection is provided facing the converter 10a. Further, magnetic shield portions 11 and 12 are provided on the driving portion 7 side and the magnet coupling 9 side of the torque detecting portion 10. The magnetic shield portion 12 on the side of the magnet coupling 9 supports the drive shaft 8 via a ball bearing 13 at the center thereof.

The magnetic shield portion includes a magnetic material inside,
By arranging a small-permeability material having a small magnetic permeability, such as an aluminum material, on the outer side, magnetism from the driving portion 7 and the magnet coupling 9 is blocked. Further, in order to block intrusion of magnetism from the outer peripheral portion, a torque detecting unit 1 is provided.
The main body frame 2a on the side of 0 is formed in a similar two-layer magnetic shield structure.

In the viscometer 1 configured as described above, the rotation of the driving unit 7 is transmitted to the rotor 5 via the magnetic coupling 9 by the operation of the control unit 6, and the rotor 5 is placed in the measurement fluid. When immersed, the viscous resistance according to the viscosity
And the drive shaft 8 receives a torsional torque.

When the drive shaft 8 receives a torsional torque, the conversion unit 10a receives a torsion via the drive shaft 8, and generates a magnetic field on the outer periphery according to the strength of the torsion. By detecting the strength of this magnetic field via the amorphous wire 10b, the magnitude of the torque acting on the drive shaft 8 can be grasped. At this time, by forming the conversion section 10a to have a small diameter by painting or the like, it is possible to detect a minute torque.

The viscometer 1 connects the driving unit 7 and the magnetostrictive torque sensor 10 via the magnetic shield member 11 to the drive shaft 8.
Therefore, even when a small-sized and large-torque DC motor is arranged in the driving unit 7, it is possible to detect the minute torque with high accuracy by the magnetostrictive torque sensor while minimizing the influence of the magnetism of the motor. it can.

Further, by interposing a magnetic coupling 9 which is driven to rotate in a non-contact manner between the drive shaft 8 and the rotor 5, the intrusion of a test fluid or other foreign matter is prevented and the torque detecting section 10 is protected. Therefore, simple handling including washing after measurement is possible. In this case, by providing a magnetic shield member 12 between the magnetic coupling 9 and the torque detecting unit 10 for blocking the magnetism of the magnetic coupling, the influence of the magnetism of the magnetic coupling 9 is suppressed and the torque from the rotor 5 is increased. It can be detected with accuracy.

Further, by forming the main body frame 2a on the side of the magnetostrictive torque sensor with a magnetic shield member, detection accuracy can be secured without being affected even in a magnetic environment.

As described above, the viscometer of the present invention can be reduced in size and cost with a simple configuration while ensuring the detection accuracy of viscosity over a wide range. Therefore, the viscometer can be configured to a size equivalent to a penlight, so that it is carried in a work site in a pocket,
Viscosity measurement can be easily performed regardless of the target fluid and without having to select a main body or a rotor.

[0020]

The viscometer according to the present invention has the following effects. Since a magnetic shield member is provided between the electric motor and the magnetostrictive torque sensor, even when a high-output DC motor or the like is arranged in the driving part, the magnetic effect is suppressed to a small extent, and the magnetostrictive torque sensor has a wider range. Since the detection accuracy of torque can be ensured, high-precision measurement can be performed in a wide viscosity range.

Therefore, the viscometer of the present invention can be miniaturized with a simple configuration, and can detect a wide range of viscosities without having to use a measuring device main body and various rotors for each viscosity region. Therefore, the viscosity of the test fluid can be easily measured by carrying it to the work site due to its easy handling.

A magnetic coupling is provided between the drive shaft and the rotor for non-contact rotation of the rotor, thereby defining a space between the rotor and the torque detector. By providing a magnetic shield member intercepting the magnetism due to the magnetic coupling, the torque detector can be protected to prevent the intrusion of the test fluid or other foreign matter, and the magnetic shield member can be used to protect the magnetic force of the magnetic coupling. Since the influence is suppressed, the handleability can be ensured without impairing the torque detection accuracy. By forming the side of the magnetostrictive torque sensor with a magnetic shield member, the influence can be suppressed even in a magnetic environment, and the detection accuracy can be secured. The ring-shaped converter of the magnetostrictive torque sensor is formed by coating or plating a ferromagnetic material on the outer peripheral surface of the drive shaft. It is possible to reduce the size of the entire configuration and improve the handling while ensuring the torque detection accuracy.

[Brief description of the drawings]

FIG. 1 is an internal structural view of a viscometer according to the present invention, which is partially broken.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Viscometer 2 Body frame 2a Body frame (magnetic shield part) 3 Measuring cylinder 5 Rotor 5a Magnet 7 Drive part (motor) 8 Drive shaft 9 Magnet coupling 9a Magnet 9b Fixed shaft 10 Torque detecting part (Magnetostrictive torque sensor) 10a Converter 10b Amorphous wire 11, 12 Magnetic shield member

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[Procedure amendment]

[Submission date] June 14, 1999 (1999.6.1
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (4)

[Claims] A rotor that rotates while receiving viscous resistance;
A drive shaft that connects the rotor and its driving unit is provided, and a torque detector that detects a drive torque of the drive shaft is provided. The viscosity of the fluid acting on the rotor is calculated by comparing the detected torque. A viscometer, wherein a motor is arranged in the driving unit, and a drive shaft is provided with a torque detecting unit using a magnetostrictive torque sensor and a magnetic shield member for blocking magnetism received from the driving unit side. 2. A magnetic coupling for rotationally driving the rotor in a non-contact manner between the drive shaft and the rotor to define a space between the rotor and the torque detector. 2. The viscometer according to claim 1, wherein a magnetic shield member for blocking magnetism due to the magnetic coupling is provided between the viscometer and the coupling. 3. The magnetic sensor according to claim 1, wherein the side of the magnetostrictive torque sensor is constituted by a magnetic shield member.
The described viscometer. 4. The viscometer according to claim 1, wherein the ring-shaped converter of the magnetostrictive torque sensor is formed by painting or plating a ferromagnetic material on an outer peripheral surface of a drive shaft.