KR100763939B1 - Apparatus of generating torsional deflection and viscometer using the same - Google Patents

Abstract

It is an object of the present invention to provide a displacement generator which can be made small in size and which can conveniently generate a displacement which resists flow in contact with the fluid. It is also an object of the present invention to provide an apparatus for measuring physical properties of a fluid having a novel structure that is easy to manufacture small, accurate measurement is possible, and has excellent sensitivity by using the displacement generator as described above. To this end, in the present invention, a rotation displacement generator that allows a probe of a predetermined length to generate a rotational displacement around a central axis, comprising a piezoelectric actuator connected to one side of the probe to rotate the probe in the axial direction. Piezoelectric actuators provide a rotational displacement generator made by attaching one or more piezoelectric elements to an elastic body. The present invention also provides an apparatus for measuring physical properties of a fluid employing such a rotation displacement generator as a mechanism part.

Description

Rotational displacement generator and device for measuring physical properties of fluids using it {Apparatus of generating torsional deflection and viscometer using the same}

1 is a view showing a schematic configuration of an apparatus for measuring physical properties of a fluid according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the structure of a mechanism part of the apparatus for measuring physical properties of fluid shown in FIG. 1. FIG.

3 is a plan view seen from the direction III of FIG.

4 shows schematically the driving principle of a monomorph actuator.

5 is a plan view illustrating a state in which the probes shown in FIGS. 2 and 3 are rotated by an angle.

6 is a view showing a schematic configuration of an apparatus for measuring physical properties of a fluid according to a second embodiment of the present invention.

FIG. 7 is an exploded perspective view showing the configuration of a mechanism part of the apparatus for measuring physical properties of fluid shown in FIG. 6; FIG.

8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7.

9 is an exploded perspective view showing the configuration of a modification of the mechanism shown in FIG. 7;

10 is a cross-sectional view taken along the line X-X of FIG.

11 is an exploded perspective view showing a configuration of another modification of the mechanism shown in FIGS. 7 and 9.

12 is a perspective view of a piezoelectric actuator used for a mechanism part constituting an apparatus for measuring physical properties of a fluid according to a third embodiment of the present invention.

FIG. 13 is a view schematically showing a configuration of a mechanism part constituting an apparatus for measuring physical properties of a fluid according to a third embodiment of the present invention. FIG.

FIG. 14 is a sectional view taken along the line XIV-XIV in FIG. 13; FIG.

15 is a view showing another modified example of the mechanism shown in FIG. 13;

16 is a view showing the operation of the piezoelectric actuator used in the physical property measurement device of the fluid according to the fourth embodiment of the present invention.

FIG. 17 is a view schematically showing a configuration of a mechanism part used in a device for measuring physical properties of a fluid according to a fourth embodiment of the present invention. FIG.

<Explanation of symbols for main parts of drawing>

20, 120, 220, 420, 520: Mechanism part

21, 521: piezo actuator

23: elastic body 25: housing

26, 126, 426, 526: probe 27: cover

30: power supply unit 40: control unit

50: display unit 60, 160: container

70: fluid 126a: thread

128, 528: outer finish 129, 529: inner finish

130: finish support rod 328: mass part

421: piezoelectric element 429: finish

430, 530, 535: fixed member

S1, S2: piezoelectric elements for driving R1, R2: piezoelectric elements for sensing

The present invention relates to a rotation displacement generator and an apparatus for measuring physical properties of a fluid using the same. More particularly, the present invention provides a rotation displacement generator that can be easily manufactured in a small size using a piezoelectric element, and a mechanism for generating such rotation displacement. It relates to a device for measuring the physical properties of fluids.

Fluids have the property of resisting flow as they flow, which is called viscosity. That is, when a fluid is flowing, a force that tries to prevent motion from each other by an intermolecular pulling force between each layer in the fluid or between the fluid and the solid is a viscosity. This magnitude of viscosity is referred to as viscosity or viscosity.

Usually the viscosity of a fluid varies with temperature and pressure. For liquids, the viscosity decreases with increasing temperature and the viscosity increases with increasing pressure. When fluid elements in adjacent parts flow at different speeds in a moving fluid, a velocity gradient occurs between the two adjacent parts, which are associated with shear stress. Fluids whose shear stress is directly proportional to the velocity gradient are called Newtonian fluids, and all other fluids are called non-Newtonian fluids.

Such a device for measuring the viscosity of the fluid is called a viscometer (viscometer), the type that is currently used a lot, such as capillary viscometer, rotary viscometer, falling viscometer. The principle and function of this viscometer will be briefly described as follows.

A rotary viscometer is a device that measures the viscosity of a fluid by measuring the resistive force of a moving fluid on a cylinder or disc. Rotary viscometers measure the viscosity of the fluid's resistive force by measuring the difference between the torque required to rotate the probe placed in the atmosphere with the motor and the torque required to rotate the probe in contact with the fluid with the motor. do. However, the rotational viscometer has a disadvantage in that the size of the rotary viscometer is large due to the power transmission elements such as a belt and a gear installed between the motor and the probe for the rotation of the motor and the probe.

Falling-type viscometer is a device that measures the viscosity by measuring the terminal velocity (falling velocity) of the falling sphere in the liquid, if a separate sample is taken to measure the viscosity in the laboratory can be used as a means of measuring the viscosity, but for industrial It has a disadvantage that it is not suitable to measure the viscosity of the fluid by applying directly to the container containing the fluid.

A capillary viscometer is a device that measures the mass flow rate and pressure drop of a fluid under normal flow and measures the viscosity using Poiseuille's law. The steady flow state of a fluid is a flow in which the flow state of the fluid does not change with time and remains constant. A transient or transient flow is a fluid whose flow state changes with time. Is the state of flow. Existing capillary viscometer takes a lot of time to obtain the experimental results at a given shear rate because it is made in the steady state in viscosity measurement, even in this case there is a limit to make small for industrial use.

In addition, for these conventional viscometers, it is impossible to measure the density together. The kinematic viscosity is one of the many properties measured to determine the properties of a fluid, which is the viscosity divided by the density. In order to determine the kinematic viscosity, it was necessary to measure the density separately determined in the prior art. Often, to determine the density of a fluid, a method of measuring the weight and volume of the fluid and calculating it from the definition of density is used. However, in the laboratory it can be easy to measure in this way, but in the industrial field such a method of measuring weight and volume makes it difficult to determine the density.

In addition, when oil is used, such as a transmission of a turbine, an engine, or a vehicle, which constitutes various machinery, and the state of the oil affects the operation of the machinery, it is very necessary to measure various physical properties of the oil in real time. . However, conventional methods of measuring physical properties of fluids such as (absolute) viscosity, kinematic viscosity and density may be suitable for measuring in a laboratory, but are not suitable for providing such physical data to reflect the operation of a mechanical device in real time. Therefore, there is a great need to develop a device that can be manufactured in a small size that does not significantly affect the design of the existing mechanical device and at the same time accurately measure the physical properties of the fluid.

In addition, during the manufacturing process, check the state of the molten plastics, fermentation of foods such as miso or soy sauce, or other fine chemicals, polymers, adhesives, coating paints, general paints, aqueous solutions, two-phase or In order to check the condition of multi-phase fluids, it is necessary to develop a device for measuring the physical properties of fluids that is easy to manufacture and to accurately measure the physical properties of fluids in the industrial field. very big.

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a displacement generator that can be made small in size and can conveniently generate displacement resistant to flow in contact with a fluid.

It is also an object of the present invention to provide an apparatus for measuring physical properties of a fluid having a novel structure, which is easy to manufacture small using the displacement generator as described above, accurate measurement of viscosity, and excellent sensitivity.

An object of the present invention as described above, the displacement generating unit for generating a displacement in the direction of resistance to the viscous resistance in contact with the fluid; A power supply unit providing power to the displacement generator; A sensor unit installed in the displacement generating unit and outputting a signal according to the generated displacement; And a control unit supplying power from the power supply unit as an input signal to the displacement generating unit, and comparing the pre-stored data based on the output of the sensor unit to calculate physical property data of the fluid. By providing.

Here, the displacement generating unit, the probe in direct contact with the fluid; And a piezoelectric actuator connected to one side of the probe to rotate the probe in the axial direction.

Here, the piezoelectric actuator is preferably a monomorph actuator made by attaching an elastic body and a first piezoelectric element.

Here, the sensor unit preferably includes a second piezoelectric element attached to one surface of the monomorph actuator.

Herein, the controller may apply a driving signal to the first piezoelectric element, and calculate the viscosity by receiving an output signal from the second piezoelectric element that is deformed and generates a voltage signal as the monomorph actuator is deformed.

Here, the probe is made in a cylindrical shape, a plurality of piezoelectric actuators are installed, each of the plurality of piezoelectric actuators, one end is fixed to one side of the probe and the other end is fixed to the housing so that the probe is the central axis of the longitudinal direction It is desirable to generate a rotational displacement that rotates around.

Here, the plurality of piezoelectric actuators are disposed at regular intervals from each other, it is preferably fixed to form a substantially right angle to the probe.

Alternatively, the probe may have a hollow cylindrical shape, and a plurality of piezoelectric actuators may be installed, and the plurality of piezoelectric actuators may be disposed inside the probes, and ends thereof may be fixed to both ends of the probes. Preferably, one end is fixed to the housing and generates a rotational displacement that rotates around the longitudinal central axis of the probe.

Here, a predetermined mass part may be attached to an opposite end portion of the probe fixed to the housing, and the plurality of piezoelectric actuators may be disposed in parallel to the length direction of the probe at regular intervals.

Alternatively, the piezoelectric actuator may include a piezoelectric element having a hollow portion formed in a cylindrical shape, and a fixing member fixed to an end portion of the piezoelectric element.

Here, the piezoelectric element is installed in the inside of the probe, it is preferable that the outer surface of the piezoelectric element and the inner surface of the probe are coupled to be deformed together with respect to the force in the circumferential direction.

Alternatively, the piezoelectric actuator is preferably formed by combining a plurality of piezoelectric elements together to have a cylindrical cylinder shape.

Here, the piezoelectric actuator has a hollow portion formed along a central axis thereof, and an outer fixing member and an inner fixing member are inserted into and fixed to the hollow portion, and the outer fixing member is fixed to an outer end of the probe.

In all the physical property measuring devices of the fluids mentioned so far, it is preferable that the probe is at least five times longer than the diameter.

In addition, the object of the present invention as described above, a rotation displacement generator that allows a probe of a predetermined length to generate a rotational displacement around a central axis, piezoelectric actuator connected to one side of the probe to rotate the probe in the axial direction Wherein the piezoelectric actuator is achieved by providing a rotational displacement generator made by attaching one or more piezoelectric elements to an elastic body.

Here, the probe is made in a cylindrical shape, a plurality of piezoelectric actuators are installed, each of the plurality of piezoelectric actuators, one end is fixed to one side of the probe and the other end is fixed to the housing so that the probe is the central axis of the longitudinal direction It is desirable to generate a rotational displacement that rotates around.

Here, the plurality of piezoelectric actuators are disposed at regular intervals from each other, it is preferably fixed to form a substantially right angle to the probe.

Alternatively, the probe may have a hollow cylindrical shape, and a plurality of piezoelectric actuators may be installed, and the plurality of piezoelectric actuators may be disposed inside the probes, and ends thereof may be fixed to both ends of the probes. Preferably, one end is fixed to the housing and generates a rotational displacement that rotates around the longitudinal central axis of the probe.

Here, it is preferable that a predetermined mass part is attached to the opposite end where the probe is fixed to the housing, and the plurality of piezoelectric actuators are arranged side by side in the longitudinal direction of the probe at regular intervals from each other.

In addition, the object of the present invention as described above is a rotation displacement generator that allows a probe of a predetermined length to generate a rotational displacement around a central axis, the piezoelectric actuator is connected to one side of the probe to rotate the probe in the axial direction And the piezoelectric actuator is achieved by providing a rotational displacement generator comprising a piezoelectric element made in a cylindrical shape and a fixed member coupled to the piezoelectric element.

Here, the piezoelectric element is installed in the inside of the probe, it is preferable that the outer surface of the piezoelectric element and the inner surface of the probe are coupled to be deformed together with respect to the force in the circumferential direction.

Here, the piezoelectric actuator is preferably made by combining a plurality of piezoelectric elements to have a cylindrical cylinder shape.

Here, the piezoelectric actuator has a hollow portion formed along a central axis thereof, and an outer fixing member and an inner fixing member are inserted into and fixed to the hollow portion, and the outer fixing member is fixed to an outer end of the probe.

Here, the probe is made in a cylindrical shape, a plurality of piezoelectric actuators are installed, some of the plurality of piezoelectric actuators are used for driving, some are used for the measurement of the rotational displacement generated by the driving piezoelectric actuators It is preferable.

Hereinafter, with reference to the accompanying drawings will be described in detail a specific embodiment of the present invention.

<First Embodiment>

1 is a view schematically showing the configuration of a device for measuring the physical properties of a fluid according to a first embodiment of the present invention.

As illustrated in FIG. 1, the apparatus for measuring physical properties of a fluid according to the first exemplary embodiment of the present invention includes a mechanism 20, a power supply 30, and a controller 40.

The mechanism part 20 includes a probe 26 in contact with a fluid, a displacement generator for generating a displacement in a direction in which the probe 26 resists a viscous resistance, and a displacement generated in the displacement generator. It includes a sensor unit for outputting a signal. Although the detailed configuration of the displacement generating part and the sensor part is not revealed by the cover 27 in FIG. 1, the displacement generating part rotates the probe 26 extending below the housing 25 of the mechanical part in place about its central axis. It generates a rotational displacement in the direction. In addition, the sensor unit functions to output a relative magnitude in which the rotational displacement of the probe differs from each other in the air and in a state of being submerged in the fluid.

The power supply unit 30 performs a function of providing power to the displacement generating unit.

The control unit 40 supplies the power from the power supply unit 30 as an input signal to the displacement generating unit, compares the stored data with the pre-stored data based on the output of the sensor unit, or calculates using a pre-stored formula. Perform the function of calculating data. Although the physical property data of the fluid which can be measured here is a viscosity normally, other physical property data, such as a density, can also be measured in some cases.

In addition, the apparatus for measuring physical properties of the fluid according to the first embodiment of the present invention may be provided with a separate thermometer (not shown) to measure the temperature of the fluid, and input the temperature data as a digital signal to the controller, such as viscosity. It can also be used to calculate property data.

In addition, the apparatus for measuring the physical properties of the fluid according to the first exemplary embodiment of the present invention may further include a display unit 50 to display the information on the data calculated by the controller for the user to view.

FIG. 2 is a perspective view illustrating a state in which a cover is opened in the apparatus for measuring physical properties of a fluid according to the first embodiment of the present invention shown in FIG. 1, and FIG. A plan view seen in the direction III is shown, and FIG. 4 is a schematic view showing the principle of construction of a piezoelectric actuator used in the mechanism of the device for measuring the physical properties of the fluid shown in FIG. 2, and FIG. 5 is compared with FIG. 3. The figure shows the state in which the probe is rotated by a predetermined angle.

As shown in Fig. 2 and 3, the displacement generating portion constituting the mechanism portion 20 of the physical property measurement device of the fluid, from the upper side to support the probe 26 extending from the lower side to be immersed in the fluid to be measured viscosity at least a portion. Two piezoelectric actuators 21 are included. It is preferable that the said probe 26 is cylindrical shape, and it is preferable that the length of the part submerged in the fluid of the viscosity measurement object of the lower part is 5 times or more of diameter. One end of the piezoelectric actuator 21 is fixed to the probe 26 and the other end of the piezoelectric actuator 21 is fixed to the housing 25.

It is preferable that the probe 26 has a cylindrical shape, considering that the shape of the ideal mechanism part when measuring the viscosity of the fluid is an infinitely long boundary system, and the side effect can be minimized. This is because the cylindrical shape is suitable for manufacturing for industrial use. The longer the length of the probe 26 is, the longer the length of the probe 26 is, because the longer the length can avoid the effect of the corner effect, and if the length is longer than 5 times, the corner effect becomes negligible.

Each of the piezoelectric actuators 21 includes a plate-shaped elastic body 23 that is thin and long compared to its width, and piezoelectric elements S1 and S2 attached to one surface of the elastic body 23.

When the piezoelectric actuator 21 shown in Figs. 2 and 3 is arranged in a state where one end is fixed as shown in Fig. 4, and a voltage is applied to both surfaces of the piezoelectric element S1, the piezoelectric element S1 Is transformed. The direction of deformation depends on the polarization direction of the piezoelectric element S1 and the voltage application direction of which the + or − voltage is applied. In any case, the polarization direction and the voltage application direction of the piezoelectric element S1 may be adjusted so that the length of the piezoelectric element S1 is longer or shorter.

If the length of the piezoelectric element S1 is adjusted to be longer as a voltage is applied, the piezoelectric actuator 21 is deformed in one direction as indicated by a dotted line in FIG. 4. The amount of deformation of the piezoelectric actuator 21 may be adjusted by adjusting the magnitude of the applied voltage.

When the appropriate voltage is applied from the mechanism 20 shown in FIG. 3 using the piezoelectric actuator 21 driven as described above, the probe 26 may be rotated as shown in FIG. 5. When the applied voltage is removed, the state shown in FIG. 3 is restored. By this principle, the displacement generator is operated.

On the other hand, in order to drive the piezoelectric actuator 21, even if a monomorphic form (monomorph) attached to the piezoelectric elements (S1, S2) on only one surface of the elastic body 23 can cause the above motion, if the piezoelectric elements ( When the piezoelectric actuator 21 is configured in a bimorph form to which S1, S2, R1, and R2 are attached, the displacement can be further increased.

In addition, in the state where the piezoelectric actuator 21 is configured in the form of bimorph, only the piezoelectric elements S1 and S2 on one side may be used for driving, and the piezoelectric elements R1 and R2 on the other side may be used for sensing. That is, the piezoelectric elements R1 and R2 which are not used for driving can be used as the sensor part among the mechanism parts constituting the fluid property measuring apparatus according to the first embodiment of the present invention.

As shown in FIG. 3, in the state in which the piezoelectric elements S1, S2, R1, and R2 are disposed on both surfaces of the elastic body, a voltage is applied to the piezoelectric elements S1 and S2 on one side thereof so that the probe 26 is predetermined. As the piezoelectric elements S1 and S2 on one side are rotated at an angle, the piezoelectric elements R1 and R2 on the other side that are deformed together generate a voltage proportional to the amount of deformation due to the physical characteristics of the piezoelectric elements. As such, when the voltage generated by the piezoelectric elements R1 and R2 on the other side is measured, the rotational displacement of the probe 26 may be measured. In addition, the rotational displacement of the probe 26 in the atmosphere at the time of applying a predetermined voltage and the rotational displacement of the probe 26 in the state in which the probe 26 is immersed for a predetermined depth or more in the fluid to be measured for viscosity By measuring this, the viscosity of the fluid can be calculated.

Meanwhile, as illustrated in FIGS. 2 and 3, the plurality of piezoelectric actuators 21 are preferably disposed at regular intervals from each other. This is because the force applied to the probe 26 by the piezoelectric actuator 21 must be uniform to rotate the probe 26 evenly. 2 and 3 show that the piezoelectric actuators 21 are fixed while being substantially perpendicular to the probe 26. However, the present invention is not limited thereto, and the piezoelectric actuators 21 may be connected to the probes. It also includes the case where it is fixed while having an inclination in 26).

Second Embodiment

6 is a view showing the configuration of the physical properties of the fluid measuring apparatus according to a second embodiment of the present invention, Figure 7 is an exploded perspective view schematically showing the configuration of the mechanism of the physical properties measuring device of the fluid shown in FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG.

As shown in FIG. 6, the apparatus for measuring physical properties of a fluid according to the second exemplary embodiment of the present invention includes a mechanism unit 120, a power supply unit 30, and a controller 40 as in the first exemplary embodiment.

The second embodiment differs from the first embodiment described above in that the structure of the mechanism 120 is different from that of the mechanism 20 of the first embodiment. The structure of the mechanism part 120 in 2nd Example is as follows.

As shown in FIG. 7, the mechanism 120 of the apparatus for measuring physical properties of the fluid according to the second embodiment of the present invention includes a hollow cylindrical probe 126 having a thread 126a formed at one side thereof, and the probe 126. Piezoelectric actuator 21 is installed on the inside. Two piezoelectric actuators 21 are installed, and the ends of the piezoelectric actuators 21 are fixed to the outer finishing member 128 and the inner finishing member 129 closing both ends of the probe 126. The outer finisher 128 is fixed to the probe 126 outside the end of the probe 126, and the inner finisher 129 is fixed to the probe 126 on the inner side of the probe, thereby substantially the piezoelectric body. The actuators 21 are arranged as fixed to both ends of the probe 126.

The two piezoelectric actuators 21 are arranged to be substantially 180 degrees with respect to the central axis of the probe 126, and since being disposed substantially parallel to the probe 126 is advantageous in reducing the space desirable. However, the piezoelectric actuator 21 is not necessarily arranged in parallel with the probe 126, but is also included in the present invention when the piezoelectric actuator 21 is disposed in an inclined manner without being disposed in parallel.

 As in the first embodiment, the piezoelectric actuator 21 has a shape in which the piezoelectric elements S1 and S2 for driving and the piezoelectric elements R1 and R2 for sensing are attached to the elastic body 23, respectively.

The probe 126 may be fixed to the wall surface of the container 160 containing the viscosity measurement fluid 70 by using the thread 126a formed on one side, and in the fixed state of the piezoelectric actuator 21. It is possible to measure the viscosity while causing rotational displacement by driving. The measurement method of the viscosity is the same as in the first embodiment.

9 shows a variant of the mechanism shown in FIG. 7, and FIG. 10 is a cross-sectional view taken along the line X-X of FIG. 9.

As shown in Fig. 9 and Fig. 10, in the mechanism part of the present modification, four piezoelectric actuators 21 are used and arranged at substantially right angles to each other. When four piezoelectric actuators 21 of the same type are used as described above, the rotational displacement of the probe 126 can be further increased, and the sensing piezoelectric elements R1 and R2 attached to the respective piezoelectric actuators 21 can be increased. ) Has the advantage of reducing the measurement error by combining the measured values.

11 shows another modification of the mechanism shown in FIG. 7.

As shown in FIG. 11, in the mechanism part of this modification, the mass part 328 is attached to the edge part of the probe 126, ie, the end surface of the outer finishing material 128. As shown in FIG. As the mass portion 328 is further attached, the rotation momentum of the probe 126 may be greater during the operation of the probe 126 causing the rotational displacement, which may help to measure the viscosity more accurately.

Also in the case of the probe 126 shown in Figs. 6 to 11, it is preferable that the length of the portion in contact with the fluid is longer than five times as long as the corner effect can be avoided.

Third Embodiment

12 to 14 are views for explaining the configuration of the physical property measurement device of the fluid according to the third embodiment of the present invention.

The physical property measurement apparatus of the fluid according to the third embodiment of the present invention described with reference to FIGS. 12 to 14 is basically installed and used on one side of the container containing the fluid in a manner similar to the second embodiment shown in FIG. Can be. The difference from the second embodiment is that the structure of the mechanism part is different.

As shown in Fig. 12, the third embodiment uses a piezoelectric actuator in which a torsional displacement occurs when a voltage is applied. The piezoelectric actuator includes a piezoelectric element 421 having a cylindrical shape having a hollow portion and a fixing member 430 fixed to the hollow portion of the piezoelectric element 421. When a voltage is applied to the piezoelectric element 421 in a predetermined direction in this configuration, a torsional displacement occurs about the fixing member 430. In addition, the direction of the torsional displacement may be adjusted by adjusting the direction in which the voltage is applied.

As shown in FIG. 13 and FIG. 14, the piezoelectric actuator shown in FIG. 12 is inserted into the hollow cylindrical probe 426 with one side closed, and the inner surface of the probe 426 and the piezoelectric element 421 are separated from each other. The outer surface is fixed to manufacture a rotation displacement generator 420. That is, when the torsional rigidity of the fixing member 430 is made much larger than the torsional rigidity of the probe 426, the probe 426 may generate rotational displacement about the fixing member 430. In this case, the fixing member 430 is fixed to the finishing material 429 fixed to the probe, and the finishing material is formed with a fixing means for fixing the container containing the fluid, for example, a screw thread 429a. The rotation displacement generator 420 functions as a mechanism of the apparatus for measuring the physical properties of the fluid according to the third embodiment of the present invention. In the case of using the mechanism configured as described above, the piezoelectric actuator performs the functions of generating rotational displacement and measuring at the same time.

On the other hand, a variety of methods for fixing the inner surface of the probe 426 and the outer surface of the piezoelectric element 421 may be used, if the rotational displacement of the desired probe 426 is coupled to each other only in the rotation direction Since the inner surface of the probe 426 and the outer surface of the piezoelectric element 421 may be formed in any shape, a method of processing the surface may be applied. Moreover, the method of using an adhesive etc. is also possible.

15 shows a modification of the mechanical part of the apparatus for measuring physical properties of a fluid according to the third embodiment of the present invention described with reference to FIGS. 12 to 14.

As shown in Fig. 15, the present modification is to change the use of one piezoelectric element in the mechanism part of the third embodiment to a plurality of relatively small piezoelectric elements. In such a configuration, there is an advantage that the driving voltage of the piezoelectric element can be lowered. In addition, although two piezoelectric elements 421a and 421b are illustrated here, three or more piezoelectric elements may be used in some cases. In addition, when a plurality of piezoelectric elements are provided, some piezoelectric elements may be used for driving rotation displacement generation, and the remaining piezoelectric elements may be used for displacement measurement.

Fourth Embodiment

16 and 17 are diagrams schematically showing the configuration of the device for measuring the physical properties of the fluid according to the fourth embodiment of the present invention.

The physical property measurement apparatus of the fluid according to the fourth embodiment of the present invention shown in FIGS. 16 and 17 may basically be installed and used on one side of the container containing the fluid in a manner similar to the second embodiment shown in FIG. have.

As shown in Fig. 16, the fourth embodiment uses a piezoelectric actuator 521 in which torsional displacement occurs when a voltage is applied similarly to the third embodiment. However, the difference from the piezoelectric actuator used in the third embodiment is that the piezoelectric actuator 521 is formed by combining a plurality of partially machined piezoelectric elements.

As shown in Fig. 16, for example, four partially machined and polarized piezoelectric elements are joined to each other to form a piezoelectric actuator 521 in the shape of a hollow cylinder. As shown in the drawing, the piezoelectric actuator 521 attaches an electrode and applies an electric potential, and the upper and lower parts generate a torsional displacement in opposite directions as shown in the drawing on the right. When the applied electric potential is removed, the piezoelectric actuator 521 returns to its original shape. . The deformed shape on the right side of the drawing is drawn by exaggerating the shape of the torsional displacement and is deformed only to the extent that it is difficult to visually check.

As shown in FIG. 17, fixing members 530 and 535 are provided in the hollow portion of the piezoelectric actuator 521 shown in FIG. 16, and are provided inside the cylindrical probe 526. A slight gap is formed between the outer surface of the piezoelectric actuator 521 and the inner surface of the probe 526. In the fixing member, the outer fixing member 530 and the inner fixing member 535 are separated from each other inside the hollow part of the piezoelectric actuator 521. The outer fixing member 530 is fixed to the outer finisher 528, and the outer finisher 528 is fixed to the outer end of the probe 526. The inner end of the probe 526 is fixed to the inner finish 529. The inner fixing member 535 is fixed to the inner finishing material 529. In addition, the inner finishing material may be formed with a coupling means for engaging with the wall surface of the container containing the fluid, as shown in the figure simply a thread (529a) can be fastened to the coupling hole of the container wall surface.

When a voltage is applied to the piezoelectric actuator 529 in a predetermined direction in this configuration, a torsional displacement occurs about the inner fixing member 535. That is, when the torsional rigidity of the inner fixing member 535 and the outer fixing member 530 is much larger than the torsional rigidity of the probe 526, the probe 526 rotates about the inner fixing member 535. It can cause displacement. In addition, the direction of the torsional displacement may be adjusted by adjusting the direction in which the voltage is applied.

A rotational displacement generator as shown in FIG. 17 is used as a mechanism part of the physical property measuring device of the fluid as shown in FIG. 6 to complete the fluid property measuring device according to the fourth embodiment of the present invention.

In the case of using the mechanism configured as described above, the piezoelectric actuator performs the functions of generating rotational displacement and measuring at the same time.

Although not separately illustrated, it is also possible to increase rotational displacement or lower the driving voltage by using a plurality of piezoelectric actuators as shown in FIG. 16 in series.

In the above-described embodiments, the structure in which the mechanism part including the displacement generator is fixed to the wall of the container is only shown in the form of a screw thread formed at the inner end thereof, but a separate flange may be used and other fixing means may be used. Also belongs to the scope of the present invention.

As described above, according to the present invention, there is provided a rotation displacement generator capable of repeatedly rotating a probe having a length longer than a diameter with respect to a central axis. In particular, this rotational displacement generator can be made small in size by using a piezoelectric element as an actuator, and has a linear improvement in viscosity measurement performance when it is used in a viscosity measuring device because the applied voltage and displacement have a linear relationship. In addition, the rotational displacement generator can generate repetitive rotational displacement.

On the other hand, by adding a mass at the end of the displacement generator to generate a greater rotation momentum, by increasing the interval for obtaining linear data, when used in the physical properties of the fluid, the sensitivity of the physical properties of the fluid measuring device Can improve.

In addition, the use of a viscosity measuring device employing such a rotational displacement generator as a mechanism portion can provide a device for measuring the physical properties of a fluid that is small in size and capable of accurately measuring real-time viscosity. In particular, by using the piezoelectric element as the actuator and the sensor, the operation of the mechanism part can be precisely controlled by the voltage signal, and the viscosity can be accurately measured according to the viscosity of the fluid to be measured.

Apparatus for measuring the physical properties of fluids according to the present invention has a structure that is easy to fabricate a small size is suitable for use in the industrial field to check the state of the raw materials or products in the fluid state during the manufacturing process. In addition, it is possible to manufacture a mechanical device such as a turbine or an engine so small that it can be mounted without changing the existing design of the mechanical device. This enables to check the state of lubricants and the like that greatly affect the operation of the mechanical device. Suitable for

So far, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary and will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. . Therefore, the true technical protection scope of the present invention should be defined by the technical spirit of the appended claims.

Claims (30)

A displacement generator for generating a displacement in contact with the fluid to resist the viscous resistance; A power supply unit providing power to the displacement generator; A sensor unit installed in the displacement generating unit and outputting a signal according to the generated displacement; And And a control unit supplying power from the power supply unit as an input signal to the displacement generating unit, and calculating and calculating physical property data of the fluid by performing comparison operation with previously stored data based on the output of the sensor unit. And the sensor unit includes a piezoelectric element in which an electromotive force is generated according to the displacement generated by the displacement generator. The method of claim 1, The displacement generating unit, A probe in direct contact with the fluid; And a piezoelectric actuator connected to one side of the probe to rotate the probe in the axial direction. The method of claim 2, The piezoelectric actuator is a physical property measurement device of the fluid, characterized in that the monomorph actuator is made by attaching the elastic body and the first piezoelectric element. The method of claim 3, wherein The piezoelectric element of the sensor unit is a physical property measurement device of a fluid, characterized in that the second piezoelectric element further attached to one surface of the monomorph actuator. The method of claim 4, wherein The controller applies a driving signal to the first piezoelectric element, and calculates a viscosity by receiving an output signal from the second piezoelectric element that is deformed as the monomorph actuator is modified to generate a voltage signal. Physical property measuring device. The method of claim 2, The probe is a physical property measuring device of the fluid, characterized in that made in the shape of a cylinder. The method of claim 6, A plurality of piezoelectric actuators are installed, Each of the plurality of piezoelectric actuators is fixed to one side of the probe and the other end is fixed to the housing so as to generate a rotational displacement to rotate the probe around the central axis in the longitudinal direction. The method of claim 7, wherein The plurality of piezoelectric actuators are arranged at regular intervals from each other, Apparatus for measuring the physical properties of the fluid, characterized in that fixed to form a substantially perpendicular to the probe. The method of claim 2, The probe has a hollow cylinder shape, A plurality of piezoelectric actuators are installed, The plurality of piezoelectric actuators are disposed inside the probe and each end thereof is fixed to both ends of the probe, The probe has a physical property measuring device of the fluid, characterized in that the one end is fixed to the housing to generate a rotational displacement to rotate around the central axis in the longitudinal direction of the probe. The method of claim 9, And a mass part having a predetermined mass is attached to the opposite end fixed to the housing of the probe. The method of claim 9, The plurality of piezoelectric actuators are physical properties measurement device of the fluid, characterized in that arranged in parallel to the longitudinal direction of the probe at regular intervals. The method of claim 2, The piezoelectric actuator is a piezoelectric element formed in a cylindrical shape with a hollow portion, And a fixing member fixed to the longitudinal opening of the piezoelectric element. The method of claim 12, The piezoelectric element is installed inside the probe, And an outer surface of the piezoelectric element and an inner surface of the probe are coupled to be deformed together with respect to a circumferential force. The method of claim 2, The piezoelectric actuator is a physical property measurement device of the fluid, characterized in that a plurality of piezoelectric elements are formed to be coupled together to have a cylindrical cylinder shape. The method of claim 14, The piezoelectric actuator has a hollow portion formed along its central axis, The outer fixing member and the inner fixing member is inserted and fixed to the hollow portion, And the outer fixing member is fixed to the outer end of the probe. The method according to any one of claims 1 to 15, The probe is a physical property measuring device of the fluid, characterized in that the length is more than five times longer than the diameter. A rotation displacement generator that enables a probe of a predetermined length to generate rotational displacement about a central axis, A piezoelectric actuator connected to one side of the probe to rotate the probe in an axial direction, The piezoelectric actuator is made of one or more piezoelectric elements attached to an elastic body, The probe has a hollow cylinder shape, A plurality of piezoelectric actuators are installed, The plurality of piezoelectric actuators are disposed inside the probe and each end thereof is fixed to both ends of the probe, And the probe has a one end fixed to the housing and generating a rotational displacement that rotates about a central axis in the longitudinal direction of the probe. delete delete The method of claim 17, The plurality of piezoelectric actuators are arranged at regular intervals from each other, And a fixed rotational angle substantially at right angles to the probe. delete The method of claim 17, Rotational displacement generator, characterized in that a predetermined mass portion is attached to the opposite end of the probe is fixed to the housing. The method of claim 17, And the plurality of piezoelectric actuators are arranged side by side in the longitudinal direction of the probe at regular intervals from each other. A rotation displacement generator that enables a probe of a predetermined length to generate rotational displacement about a central axis, A piezoelectric actuator connected to one side of the probe to rotate the probe in an axial direction, The piezo actuator is, And a fixed member coupled to the piezoelectric element, the piezoelectric element having a cylindrical shape. The method of claim 24, The piezoelectric element is installed inside the probe, And an outer surface of the piezoelectric element and an inner surface of the probe are coupled to deform together with respect to the circumferential force. The method of claim 24, The piezoelectric actuator is a rotational displacement generator characterized in that the plurality of piezoelectric elements are made to be coupled together to have a cylindrical cylinder shape. The method of claim 26, The piezoelectric actuator has a hollow portion formed along its central axis, The outer fixing member and the inner fixing member is inserted and fixed to the hollow portion, And the outer fixing member is fixed to the outer end of the probe. The method of claim 24, And the probe is made in the shape of a cylinder. The method of claim 24, And a plurality of piezoelectric actuators are installed. The method of claim 29, And some of the plurality of piezoelectric actuators are used for driving, and some are used for measuring rotational displacement generated by the driving piezoelectric actuator.

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