JP3438035B2 - Fluid viscosity measuring method and fluid viscosity measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the viscosity of a fluid based on the moving speed of a weight placed in a fluid to be measured, and an apparatus for realizing the method. The fluid to be measured includes, for example, lubricating oil used for rolling bearings, traction oil used for traction drive devices, engine oil and gear oil used for automobile engines, and various other oils.

[0002]

2. Description of the Related Art Conventionally, the viscosity of a fluid is measured using various high pressure viscometers. In short, this high-pressure viscometer is one in which a weight is put in a pressure chamber filled with a fluid and the weight is naturally dropped by its own weight. Then, the drop velocity of the weight is detected by the high-pressure viscometer, and the viscosity of the fluid is determined in consideration of the detection result and various measurement conditions.

The measurement conditions are atmospheric pressure and room temperature. In addition, when the fluid to be measured is the lubricating oil as exemplified above, the lubricating oil to be measured is approximated to the actual usage condition. Any pressure or heat is applied to.

[0004]

By the way, in the above-mentioned conventional example, since the weight is naturally dropped, that is, the weight is dropped by its own weight, the dropping speed of the weight is very slow, and it takes a lot of time for measurement. be pointed out. Moreover, under the condition that pressure is applied to the fluid, the measurement time becomes longer. By the way, if the fluid is, for example, 3 to 4.5 [G
It takes several months to measure under the pressure of [Pa]. Even if the weight is made of a dense material, the result is similar.

Further, as described above, when the time required for measurement becomes long, the viscosity cannot be accurately determined, for example, when the fluid is pressurized or heated, the lubricating oil solidifies and the viscosity increases. Is also pointed out.

Therefore, an object of the present invention is to reduce the time required for measurement.

[0007]

A first method for measuring fluid viscosity of the present invention is to rotate a container in which a fluid to be measured is filled and a weight is placed in the fluid around a rotation center. Centrifugal acceleration of the movement of the weight,
The moving speed of the weight is detected, and the viscosity of the fluid is obtained based on the detection result. In this fluid viscosity measuring method, the fluid may be pressurized or heated.

The first fluid viscosity measuring apparatus of the present invention obtains the viscosity of a fluid based on the moving speed of a weight placed in the fluid to be measured, and is filled with the fluid to be measured. A container in which a weight is placed in the fluid,
Centrifugal acceleration means for centrifugally accelerating the movement of the weight in the container,
And a detection means for detecting the moving speed of the weight.

The second fluid viscosity measuring device of the present invention obtains the viscosity of the fluid based on the moving speed of the weight placed in the fluid to be measured, and is filled with the fluid to be measured. A container in which a weight is placed in the fluid,
It includes a rotating body for holding the container at a required position deviated from the center of rotation, a driving means for centrifugally accelerating the movement of the weight by rotationally driving the rotating body, and a detecting means for detecting the moving speed of the weight.

The detecting means in the second fluid viscosity measuring device includes an irradiating means for irradiating the rotating body with light synchronized with the rotation of the rotating body, and an image taking means for photographing the rotating body irradiated with the light. Can be included. Further, the detecting means in the second fluid viscosity measuring device may be such that the photographing means for photographing the weight is attached to the rotating body together with the container in which the weight is arranged. Further, the second fluid viscosity measuring device can be provided with a means for pressurizing or heating the fluid.

In the above-mentioned present invention, in short, the weight is not forced to fall by its own weight as in the prior art, but is forcibly moved by the centrifugal force of rotation.
The moving speed of the weight can be increased as compared with the conventional example.
In particular, by controlling the number of rotations of the rotating body, the moving speed of the weight can be dramatically increased.

Since the moving speed of the weight can be increased in this way, the measurement in the case of heating the fluid is
The measurement can be completed before the oil component of the fluid, especially the lubricating oil, is altered.

Further, even when the fluid is pressurized as the measurement condition, the weight can be moved, and the measurement can be performed in the pressure application region, which has been impossible in the past.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described with reference to the embodiments shown in FIGS.

1 to 3 relate to one embodiment of the present invention, and FIG. 1 is a diagram showing a schematic configuration of a fluid viscosity measuring device,
FIG. 2 is a perspective view showing the rotary body alone of FIG. 1, and FIG. 3 is a sectional view showing a schematic configuration of a high-pressure viscometer.

In the figure, A shows the whole fluid viscosity measuring device, 1 is a high-pressure viscometer, 2 is a disk-shaped rotating body, 3 is a spindle unit, 4 is a rotating body 2 via a spindle unit 3. Is a motor for rotating the motor, 5 is a motor drive circuit, 6 is a stroboscope, 7 is a photographing camera, and 8 is a microcomputer (hereinafter abbreviated as a microcomputer). The above-mentioned rotating body 2, spindle unit 3, motor 4
Corresponds to the centrifugal accelerating means in the claims, and the stroboscope 6, the photographing camera 7, and the microcomputer 8 correspond to the detecting means in the claims.

The high-pressure viscometer 1 is called a known diamond anvil device, and as shown in FIG. 3, it is screwed to close a cylindrical case 9 and one end of a central hole of the case 9. A lid 10 and a slider 11 slidably fitted in an axially intermediate portion of the central hole of the case 9,
Pressure screw 12 screwed to the other end opening of the center hole of case 9
A spacer 13 interposed between the pressure screw 12 and the slider 11, a phosphor bronze gasket 14 and two diamond anvils 15 and 15 interposed between the slider 11 and the lid 10. I have it. The pressure chamber 17 as a container according to the present invention is configured by applying and closing the two diamond anvils 15, 15 on both sides of the through hole 16 provided at the center of the gasket 14.

The pressure chamber 17 is filled with a fluid 18 to be measured, and an appropriate weight 19 such as a steel ball is placed in the fluid 18. And
The fluid 18 in the pressure chamber 17 can be pressurized by screwing the pressure screw 12. The pressure generated by this is such that, although not shown, a ruby piece or the like is housed in the pressure chamber 17, the ruby piece is irradiated with laser light to excite the fluorescent line, and the relative relationship between the wavelength of this fluorescent line and the pressure is examined. It is designed to be detected. Also, the slider 1
The fluid 18 in the pressure chamber 17 can be heated by supplying hot air from the through hole 20 provided at the center of the pressure chamber 1. The temperature of the fluid 18 in the pressure chamber 17 is not shown, but it is not shown. Etc. Further, at the center of the lid 10, there is provided a through hole 21 as a viewing window that expands in diameter toward the outside. From this through hole 21,
The movement of the weight 19 in the pressure chamber 17 can be observed.

As shown in FIG. 2, the rotary body 2 has the above-mentioned high-pressure viscometer 1 at four circumferential positions, for example, four positions at 90 ° intervals.
Is provided with a pocket 22 for accommodating and holding. Then, the center of the case 9 of the high-pressure viscometer 1 is aligned in parallel with the center of rotation of the rotator 1, and the moving direction of the weight 19 of the high-pressure viscometer 1 is aligned with the radial direction of the case 9. There is. That is, by rotating the rotating body 2, the movement of the weight 19 is centrifugally accelerated. As shown in the figure, when four pockets 22 are provided, a maximum of four high-pressure viscometers 1 can be set at one time. However, it is also possible to set one to three high-pressure viscometers 1, and in that case, the balancer 23 for adjusting the rotational balance with respect to the remaining pockets 22.
May be attached. Of course, pocket 22
The number may be one or four or more.

The spindle unit 3 includes a spindle shaft 24 that is fixed through the center of rotation of the rotating body 2, bearing devices 25 and 26 that rotatably support both side portions of the spindle shaft 24 that sandwich the rotating body 2, and a spindle. And a coupling 27 for connecting the base end of the shaft 24 to the output shaft of the motor 4. The tip end side of the spindle shaft 24 is set to have a small diameter, and the tip end side bearing device 2
No. 5 has a structure in which two roller bearings are attached to the bearing case in order to allow thermal expansion of the spindle shaft 24. On the other hand, the base end side of the spindle shaft 24 is set to have a large diameter, and the bearing device 26 on the base end side has two angular ball bearings mounted on the bearing case in order to suppress the occurrence of vibration. It is configured.

The stroboscope 6 irradiates the rotating body 2 with light in synchronism with the rotation of the rotating body 2, and the photographing camera 7 is illuminated by the stroboscope 6 with the rotating body 2.
Is to shoot. The microcomputer 8 controls the operations of the stroboscope 6 and the motor drive circuit 5, and also controls the image processing for detecting the moving speed of the weight 19 based on the image taken by the photographing camera 7.

Next, the measuring method and procedure using the fluid viscosity measuring device A will be described.

First, the pressure chamber 17 of the high-pressure viscometer 1 is filled with the fluid 18 to be measured, and the pressure chamber 17 is also filled.
A weight 19 is put in the container, and the fluid 18 is pressurized and heated as needed. The high-pressure viscometer 1 is set in the pocket 22 of the rotating body 2. At this time, the high-pressure viscometer 1 for the rotating body 2
The balance of the rotating body 2 is adjusted according to the number of sets, etc. When the number of sets of the high-pressure viscometer 1 is two or more, the same number of stroboscopes 6 and photographing cameras 7 are prepared.

In this way, the motor 4 rotates the rotating body 2 at the required number of rotations.

As a result, a centrifugal acceleration force is applied to the weight 19 of the high-pressure viscometer 1 set on the rotating body 2, so that the weight 19 is forcibly moved in one direction of the pressure chamber 17. .

After rotating the rotator 2, the stroboscope 6 irradiates the rotator 2 with light in synchronism with the rotation of the rotator 2, so that the illuminating position of the rotator 2, that is, the position where the high-pressure viscometer 1 exists. Is photographed by the photographing camera 7. At this time, the light irradiation position of the rotating body 2 looks as if it were stationary. As a result, the photographing camera 7 can photograph the inside of the pressure chamber 17 which is seen from the through hole 21 which is the viewing window of the high-pressure viscometer 1 in the rotating body 2 in a stationary state. Therefore, by examining the relative changes in the images sequentially captured by the photographic camera 7, it becomes possible to grasp the state of movement of the weight 19 over time. Here, the moving speed of the weight 19 is detected by performing image processing on the images sequentially shot by the shooting camera 7 by the microcomputer 8. The microcomputer 8 calculates the viscosity of the fluid 18 from the detection result of the moving speed of the weight 19 and various conditions such as the rotation speed of the rotating body 2.

As a method of calculating the viscosity, the sample liquid is a Newton's incompressible fluid and the Reynolds number is sufficiently small, as shown in the document "Lubrication Vol. 32, No. 6 (1987), page 45". Assuming that, the apparent viscosity μ _A can be obtained from the balance of the viscous resistance force D, the gravity W and the buoyancy force F by the following equation.

Μ _A = (ρ _S −ρ _L ) g (2a) ² / 18V In the above equation, ρ _S and ρ _L are the densities of the nickel sphere and the sample liquid, and the respective values considering the compressibility must be used. I have to. g, a and V are the acceleration of gravity, the radius of the sphere and the terminal velocity of the sphere.

In the fluid viscosity measuring method and the fluid viscosity measuring apparatus A described above, the weight 19 using the centrifugal acceleration force is used.
Since it is forcedly moved, the moving speed of the weight 19 can be increased as compared with the conventional example, and the time required for measurement can be shortened as compared with the conventional example. By the way, when the pressure is set to 3 to 4.5 [GPa], it takes about several hours, which is much shorter than the conventional example which required several months.

The moving speed of the weight 19 can be arbitrarily adjusted by controlling the number of rotations of the rotating body 2. Therefore, in the case where the fluid 18 is heated, the fluid 18 and especially the lubricating oil is used. The measurement can be completed before the components are altered, and the viscosity of the fluid 18 can be accurately determined. Further, even when the fluid 18 is pressurized as the measurement condition, the measurement can be performed in a short time. Furthermore, by forcibly moving the weight 19, it becomes possible to measure the shear viscosity of the fluid 18 which was impossible in the past. The shear viscosity is the same as the apparent viscosity μ _A shown in the above-mentioned document “Lubrication Vol. 32, No. 6 (1987), page 45”. In other words, water, oil, etc.
The viscosity when the two planes are moved relative to each other is the same regardless of the relative velocities of the two planes. Also changes. Therefore, when measuring the viscosity of a polymer or the like, it is necessary to change the relative speed and measure the viscosity at each speed as a measurement condition. In the conventional falling ball type, the relative speed (falling ball speed) is only one type of gravitational acceleration, and therefore the change in viscosity due to the change in polymer speed cannot be measured. Since the centrifugal acceleration can be changed by changing it, the velocity-viscosity relationship can be measured.

The present invention is not limited to the above embodiment, and various applications and modifications are possible.

(1) The high-pressure viscometer 1 may have various known structures in addition to those exemplified in the above embodiment.

(2) In the above embodiment, the microcomputer 8 is used to control the operation of the stroboscope 6 and the motor drive circuit 5, and the moving speed of the weight 19 is detected based on the image taken by the photographing camera 7. Although the processing is controlled, the above-described control by the microcomputer 8 can be manually processed individually.

(3) In the above embodiment, the photographing camera is fixed and the still image of the high-pressure viscometer rotating by the stroboscope is photographed. However, separately from this, the photographing camera is used together with the high-pressure viscometer to rotate the rotating body. Alternatively, the high-pressure viscometer may be attached to the camera for photographing. In this form, the stroboscope can be omitted.

(4) In the above embodiment, the movement of the weight is measured by the photographing camera. In addition to this, the weight 19 is adjacent to the pressure chamber 17 of the high-pressure viscometer 1 along the moving direction of the weight 19. By arranging a single row of light sources and photosensors or photosensors such as CCD arrays side by side,
The moving speed of 9 may be measured.

[0036]

According to the present invention, the weight is not dropped by its own weight as in the conventional case,
Since it is forcibly moved by the rotational centrifugal force, the moving speed of the weight can be increased as compared with the conventional example, and the time required for measurement can be shortened as compared with the conventional example. Moreover, by forcibly moving the weight, it becomes possible to measure the shear viscosity of the fluid, which was impossible in the past.

Particularly, in the invention of claim 1.3.4, since the container containing the fluid and the weight is held by the rotating body and the rotating body is rotated, the movement of the weight is centrifugally accelerated. By controlling the number of rotations, the moving speed of the weight can be dramatically increased.

According to the fifth and sixth aspects of the present invention, the movement of the weight in the rotating container can be photographed in a stationary state, and the moving speed of the weight can be accurately detected.

According to the invention of claim 7, the fluid can be pressurized or heated when the viscosity of the fluid is measured, and when the fluid to be measured is lubricating oil or the like, the actual use condition of the lubricating oil is reproduced. Easier to do.

As described above, according to the present invention, since the moving speed of the weight can be increased, the measurement in the case where the fluid is heated as claimed in claim 7 is performed before the fluid, especially the oil component of the lubricating oil, is deteriorated. The measurement can be completed and the viscosity of the fluid can be accurately determined. Similarly, when the fluid is pressurized as in claim 7, it is possible to move the weight in a short time. Therefore, it is possible to perform the measurement in the pressure application region, which was impossible in the past. Become.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a fluid viscosity measuring device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a single rotating body of FIG.

FIG. 3 is a sectional view showing a schematic configuration of a high-pressure viscometer.

[Explanation of symbols]

A Fluid viscosity measuring device 1 High pressure viscometer 2 rotating bodies 3 spindle unit 4 motor 5 Motor drive circuit 6 Stroboscope 7 shooting camera 8 microcomputer 17 Pressure chamber 18 fluid 19 weights

Claims (7)

(57) [Claims] 1. The velocity of movement of the weight is centrifugally accelerated by rotating a container, in which the fluid to be measured is filled and in which the weight is arranged, around a rotation center, thereby centrifugally accelerating the movement of the weight. A method for measuring fluid viscosity, which comprises detecting the viscosity of the fluid based on the detection result. 2. The fluid viscosity measuring method according to claim 1, wherein the fluid is pressurized or heated. 3. A fluid viscosity measuring device for determining the viscosity of a fluid based on the moving speed of a weight arranged in the fluid to be measured, wherein the fluid to be measured is filled and the weight is contained in the fluid. A fluid viscosity measuring device comprising: a container to be placed, a centrifugal accelerating means for centrifugally accelerating the movement of the weight in the container, and a detecting means for detecting the moving speed of the weight. 4. A fluid viscosity measuring device for determining the viscosity of a fluid based on the moving speed of a weight placed in the fluid to be measured, wherein the fluid to be measured is filled and the weight is placed in the fluid. A container to be placed, a rotating body that holds the container at a required position deviated from the center of rotation, a drive unit that centrifugally accelerates the movement of the weight by rotationally driving the rotating body, and a detection that detects the moving speed of the weight And a means for measuring fluid viscosity. 5. The detecting means according to claim 4 comprises: an irradiating means for irradiating the rotating body with light synchronized with the rotation of the rotating body; and an imaging means for photographing the weight in the rotating body irradiated with the light. A fluid viscosity measuring device comprising: 6. The fluid viscosity measuring device according to claim 4, wherein the detecting means is attached to the rotating body together with a container in which the weight is arranged, the imaging means for capturing the weight. 7. The fluid viscosity measuring device according to claim 4, further comprising means for pressurizing or heating the fluid.