JPH03162648A - Viscosity measuring instrument - Google Patents

Abstract

PURPOSE:To measure viscosity stably for a long period without increasing the scale of the instrument nor being affected by an atmosphere where the instrument is used by vibrating the lower flat part of a ring spring by an electromagnet and putting a vibration piece in spring vibrating motion in the flat direction of the ring spring. CONSTITUTION:The ring spring 1 is obtained by forming a beltlike magnetic steel material flatly and annularly and its straight parts 11 and 11 in the flat direction are elastic in their facing direction. A shaft 4 is fitted to the lengthwise center part of the lower straight part 11 of the spring 1. The vibrating piece 5 almost in a square thin plate shape is fitted to the lower end of the shaft 4 while having its plate surface at right angles to the axial direction of the shaft 4. This vibrating piece 5 is dipped in liquid. Then an oscillator 20 oscillates a sine wave having the same current value while the frequency is varied to vibrate the shaft 4 and a signal processor 30 detects the frequency at which the amplitude becomes maximum in the detection result of a displacement detector 3 as a resonance frequency. Consequently, the obtained amplitude and frequency are used to find the viscosity from a specific expression.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus used for measuring the viscosity of a viscous sample such as a liquid.

[Prior art]

Conventional viscosity measuring devices that measure the viscosity of liquid using vibration phenomena include those that use a tuning fork as a vibration source and those that use a subica.

FIG. 2 is a schematic side view of a conventional viscosity measuring device using a tuning fork. This device has thin plate-like vibrating pieces 5, 5 attached to each end of a tuning fork 1, one of which is attached to a measuring liquid L1.
, the other is immersed in a reference liquid Lt of known viscosity, and the electromagnet 2
By excitation, the vibrating pieces 5.5 are vibrated at a frequency that resonates with the electromagnet 2, and the amplitude of each vibrating piece 5.5 is detected by the displacement detector 3 provided near the tuning fork 1. If the excitation force of the electromagnet 2 is kept constant, the amplitude of the vibrating piece 5 changes depending on the viscous resistance of the liquid. The viscosity of the measurement liquid L can be determined by comparing the amplitude in the reference liquid L2 with the amplitude in the reference liquid L2.

FIG. 3 is a schematic side view of a conventional viscosity measuring device using a speaker. In this device, a cone 81 made of paper material is attached to the inner surface of the speaker 8. and,
One end of the rod-shaped shaft 4 is attached to the center of the cone 81 . A thin plate-shaped vibrating piece 5 is provided at the other end of the shaft 4, and the cone 81 and the shaft 4
The vibrating piece 5 constitutes a spring system that vibrates in the axial direction of the shaft 4.

Further, an annular plate 41 for detecting the axial displacement of the shaft 4 is attached to one end of the shaft 4 in the axial direction so that the shaft 4 is fitted into the center thereof. When measuring viscosity, the vibrating piece 5 is immersed in the measuring liquid, and the cone 8 is
l is vibrated by the excitation of the electromagnet 2, and the vibrating piece 5 is vibrated at a frequency that resonates with the electromagnet 2 based on the relationship between the mass of the shaft 4 and the vibrating piece 5 and the spring constant of the spring system, and the shaft axis of this vibrating piece is vibrated. The amplitude of the directional vibration is detected by a displacement detector 3 provided near the annular plate 4l. In this case, if the excitation of the electromagnet 2 and the force B are kept constant, the amplitude of the vibrating element 5 changes in accordance with the viscous resistance of the measurement liquid, so the viscosity of the measurement liquid can be determined from the magnitude of this amplitude.

[Problem to be solved by the invention]

However, in the device using the tuning fork 1 as described above, it is necessary to increase the size of the tuning fork 1 in order to suppress overheating of the tuning fork 1 when the temperature of the measuring liquid Ll (7) is 1300°C to 1500'C. However, if this increase in size becomes excessive, the above-mentioned resonance state cannot be obtained in practice. For this reason, it was difficult to impart heat resistance to the tuning fork 1, and it could not be applied to the measurement of the viscosity of Takaon fluid.

Further, the device using the speaker as described above can be applied to measuring the viscosity of high-temperature fluid, but the cone 81 is made of paper material and deteriorates when used for a long period of time. There is a risk that the vibration characteristics may change significantly due to changes in the turbidity and humidity of the atmosphere. For example, if a device that maintains the temperature and humidity constant is added to this device in order to suppress changes in the vibration characteristics, the measurement device may become unnecessary. There was the problem of increasing the size.

The present invention was made in view of the above circumstances, and by using a ring spring as a vibration source, it can be used for measuring high-temperature fluids, and by forming the ring spring with a magnetic material, it is possible to increase the size of the device. It is an object of the present invention to provide a viscosity measuring device that can perform stable measurements over a long period of time without being influenced by the atmosphere in which it is used.

[Means to solve the problem]

The viscosity measuring device according to the present invention immerses a vibrating piece that works in conjunction with a vibration source vibrated by an electromagnet into a viscous sample, measures the amplitude of the vibrating piece vibrating in the sample, and uses this measurement result as a The viscosity measuring device for determining the viscosity of the sample based on the vibration source is provided with a ring spring made of a band-shaped magnetic material that is shaped like a flat ring and has elasticity in the flat direction, and the ring spring and the vibrating piece are connected to each other. are interlocked and connected in the flat direction of the ring spring.

[Function] In the present invention, the vibration source is equipped with a flat annular ring spring, and when the lower flat part of this ring spring is vibrated with an electromagnet, the vibrating piece causes spring vibration in the flat direction of the ring spring. can be used to measure viscosity.

[Examples] The present invention will be specifically described below based on drawings showing examples thereof. FIG. 1 is a schematic side view of a viscosity measuring device according to the present invention.

In the figure, reference numeral 1 indicates a belt-shaped magnetic net material formed into a flat annular shape with two straight parts 11 and two curved parts 12, 12 facing each other, and the straight parts 11, 11 in the flat direction. It is a ring spring that has elasticity in the direction in which the two are opposite to each other.

Said curved portion 12. A rod-shaped fixing member 12 is provided on the outer peripheral surface of 12.
0 and 120, respectively, and the ring spring 1 is fixed at a predetermined position by fixing members 120 and 120 with its flat direction being the vertical direction.

Further, a rod-shaped shaft 4 is attached to a longitudinally central portion of the straight portion 11 on the lower side of the ring spring l, with the axial length direction being the vertical direction. A shaft 4 is provided on the upper end side of the shaft 4.
An annular plate 41 for detecting displacement in the axial direction is attached to the center of the annular plate 41 in such a manner that the shaft 4 is fitted therein. Further, at the lower end of the shaft 4, a substantially square thin plate-shaped vibrating piece 5 is provided.
The mask is attached so as to face in a direction perpendicular to the axial direction of the shaft 4. Further, near the annular plate 4l,
A displacement detector 3 for detecting vertical displacement of the annular plate 41 is provided, and the displacement detector 3 provides the detection result to the signal processing device 30. Further, an electromagnet 2 excited by an oscillator 20 is disposed at the center of the ring of the ring spring 1 . The oscillator 20 oscillates a sine wave whose frequency can be changed within a predetermined range to the electromagnet 2, and the electromagnet 2 is excited by the manually generated sine wave, and its magnetic force causes the ring spring 1 to vibrate in its flat direction. to vibrate the shaft 4 in its axial length direction.

When measuring the viscosity of a liquid to be measured using a device configured as described above, the vibrating piece 5 is immersed in the liquid.

Then, the oscillator 20 oscillates a sine wave of the same current while changing the frequency to vibrate the shaft 4, and the signal processing device W30 sets the frequency at which the amplitude becomes the maximum among the detection results of the displacement detector 3 as the resonance frequency. Detected by Using the amplitude and frequency thus obtained, the viscosity η is determined from the measurement principle equation shown in (1) below.

π ] A′ 1 H However, r1 : Resonance frequency in air f : Resonance frequency in measurement liquid E1 : Amplitude at resonance in air E : Amplitude at resonance in measurement liquid A : Vibrating element Area of both sides Ro : Mechanical spring constant ρ : Density of the measuring liquid In the device using the ring spring l in this way, by increasing or decreasing the plate thickness and plate radius of the ring spring l, a mechanical spring suitable for the measuring liquid can be obtained. Constant Rl. It is possible to have l.

Now, the dimensions of ring spring 1 are plate thickness 0.6 mm and plate width 30.
Using the apparatus as described above, with a maximum outer diameter of the ring of 220 mm and a minimum outer diameter of the ring of 30 mm, the viscosity range was 0.1 to 4 mm.
As a result of actually measuring the viscosity of 0P CC melt powder over a long period of time, it was found that while conventional devices using speakers required device replacement every few months, the device of the present invention does not require device replacement. Met.

In this example, the ring spring is fixed using a fixing member attached to its curved part, but the fixing member is not limited to this, and the ring spring may be suspended from above by attaching a fixing member to the straight part of the ring spring. good.

〔effect〕

As detailed above, the viscosity measuring device according to the present invention can be used to measure high-temperature fluids by using a ring spring as a vibration source, and since the ring spring is made of a magnetic material, it is possible to increase the size of the device. The present invention has excellent effects, such as enabling stable measurement over a long period of time without being affected by the atmosphere in which it is used.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the configuration of a viscosity measuring device according to the present invention, Fig. 2 is a schematic side view of a conventional viscosity measuring device using a tuning fork, and Fig. 3 is a conventional viscosity measuring device using a speaker. FIG. 2 is a schematic side view of the device.

Claims (1)

[Claims] 1. A vibrating piece that is linked to a vibration source vibrated by an electromagnet is immersed in a viscous sample, the amplitude of the vibrating piece vibrating in the sample is measured, and based on the measurement results, In the viscosity measuring device for determining the viscosity of the sample, the vibration source includes a ring spring made of a band-shaped magnetic material formed into a flat ring shape and having elasticity in the flat direction,
A viscosity measuring device characterized in that the ring spring and the vibrating piece are interlocked and connected in a flat direction of the ring spring.