JP2777480B2 - Rotary viscometer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary viscometer for measuring a viscosity by bringing a rotor into contact with a liquid whose viscosity is to be measured, and rotating the rotor via a spring to measure the viscosity. The present invention relates to a rotary viscometer capable of automatically measuring viscosity characteristics in a super-bottom flow region by a spring relaxation method.

[Background Art] As this type of rotary viscometer, Journal of Paint Technology, 38
Vol. 502, November 1966 (Journal of Paint Technolo
gy Vol.38, No.502, Nov.1966), “Set ring with a shear rate range of 0.001 to 1.0 s ^-1 by applying the spring relaxation method of a cone plate type viscometer by TC PATTON. A New Method for the Vis in Paint, Leveling and Penetration "
cosity measurement of Paint in Settling, Sagging, Le
velling and Penetration Shear Rate Range of 0.001
to 1.0 Reciprocal Seconds Using a Cone / Plate Sprin
g Relaxation Technique), which is disclosed therein. This viscometer is a general-purpose rotary viscometer with a cone-plate type rotor in the measuring section (Well-Boo Brookfield Micro Viscometer RT V-cone plate type) (Wells-B
rookfield Micro Viscometer RTV Cone Plate Model)
It is.

FIG. 4 shows an outline of the configuration of this type of viscometer. In this type of viscometer, a scale disk 3 is attached to a drive shaft 2 rotated by a drive motor 1 with a speed reducer. A rotor shaft 5 is connected to a lower end 2 ′ of the drive shaft 2 via a spring 4.
At the lower end of the rotor shaft 5, a sample liquid 9 whose viscosity is to be measured is sandwiched between the cone-shaped rotor 6 and the plate 7 and narrowed. This state is shown enlarged in FIG.

On the other hand, a pointer 8 extending above the scale disk is attached to the rotor shaft 5, and the relative amount of angular displacement between the drive shaft 2 and the rotor shaft 5 is read by the position of the pointer 8 on the scale disk 3. be able to. That is, if the torsion spring constant of the spring 4, the dimensions of the rotor 6, and the rotor rotation speed are determined, the index of the pointer 8 on the scale disk 3 is proportional to the viscosity of the sample liquid. Can be requested.

In the description of the operating principle of the viscometer used in the report,
The operating principle is shown assuming that the rotor shaft 5, the rotor 6, and the pointer 8 engage the lower end 2 'of the drive shaft via the spring 4. However, in such a structure, the rotor shaft 5 system is unstable. Therefore, in an actual viscometer, as shown in FIG. 6, the rotor shaft 5a is supported by a pivot 11 and a jewel bearing 12, and the runout at the upper end is stopped by a pin 13 penetrating the shaft hole. In each of the other parts, a is added to the reference number drawn from the corresponding part in FIG. However, the fourth
A spiral spring is used for 4a corresponding to the spring 4 in the figure. 17
Is a jacket for keeping the sample solution at a constant temperature, and circulating water can flow from a separately prepared constant temperature bath.

Further, in the present viscometer, when the viscosity is measured, the pointer 8a and the scale disk 3a are also rotating, so that it is difficult to read the finger index during rotation. Thus, the standard operation of the present viscometer is performed by the following method. After the finger stabilizes after the viscometer starts rotating, the clamp lever shown in FIG.
14 is pushed down with a finger, and the lifting tip 15 is pushed up with the fulcrum at 14 '. Along with this, the scale disk shaft 16 engaged with the lifting tip 15 and the scale disk 3a connected thereto are pulled upward. As a result, the pointer 8a and the scale disk
In a state where the knurled groove (not shown) formed in the outer peripheral portion of 3a meshes and rotates, the pointer 8a is clamped to the scale disk 3a while maintaining the finger strength. When the motor is stopped in this state, the pointer 8a stops while being clamped by the scale disk 3a, so that the finger index can be easily read. When the clamp lever 14 is released, the pointer 8a and the scale disk
The engagement of 3a is released, and the pointer 8a is released and returns to the scale index 0.

This report reports the measurement of the viscosity in an ultra-low flow region by a spring relaxation method utilizing the relaxation of a spiral spring using the above-mentioned viscometer. In the viscosity measurement by relaxation of the spring, before filling the sample liquid between the cone and the plate, and before attaching the measuring part, the position where the spiral spring of the viscometer becomes full scale (the pointer is 100 ), And then rotate the rotor by hand until the pointer is clamped in that position. When the spiral spring is involved, the rotor at the lower end of the rotor shaft is gently turned by hand so that the pointer indicates 100 scales. In order to fix the pointer at this position, that is, to fix the spiral spring in a wound state, the clamp lever is pressed down, and then a rubber band is wound around the lever to fix the clamp lever in a depressed state.
After that, the state is kept until the lever is loosened to perform the actual viscosity measurement. Next, the viscosity is measured according to the following procedure.

Set the stopwatch to zero, release the lever holding the pointer at 100 divisions, and start the stopwatch at the same time. The scale is then read at appropriate time intervals (eg, every 10-15 seconds at start, every 30 seconds at end). The measurement time is completed in a few minutes. The measurement is terminated when the amount of change from the previous read value is less than one division.

The data thus obtained is plotted on semilog graph paper. Scale reading is a logarithmic scale (2 cycles)
FIG. 7 exemplifies the obtained curve with the time data taken on a uniform scale. The viscosity at an arbitrary point on the curve, and the shear stress and shear rate corresponding to that point are determined as follows.

First, the shear stress is determined from a coordinate value that cuts a logarithmic axis by drawing a horizontal straight line to the left from a point to be determined. This reading is proportional to the shear stress τ and can be converted to a shear stress expressed in dyne / cm ² by multiplying by an appropriate constant.

If the maximum torque of the spiral spring of the viscometer (corresponding to full scale 100 graduations Yubido) and M _100, torque Ms for any finger of S is given by equation (1).

Ms = (S / 100) M ₁₀₀ (1) As shown in the enlarged view of the cone-shaped rotor section in Fig. 5, shear stress applied to the sample liquid filled between the rotating cone of the viscometer and the stationary plate. The relationship between τ and the torque M applied to the cone has the relationship of equation (2), where r is the radius of the cone.

τ (Shear Stress) = 3M / 2πr ³ (2) By substituting equation (1) into equation (2), equation (3) is obtained.
Here, τ _s is the shear stress acting on the sample liquid when the scale index is S.

τ _s = 3 (S / 100) M ₁₀₀ / 2πr ³ (3) Consider a case where the pointer is firstly clamped in advance at the position of the scale index S ₀ . At this stage, the rotor:
Although the torsion reaction force of the spiral spring is applied, the rotation of the rotor is suppressed by the clamp mechanism. When the clamp is released at the start of measurement (t = 0), the spiral spring starts to loosen, and the rotor starts rotating.

Assuming that the change in the finger index during the short time dt is ds, the time
The minute angle dθ (unit radina) of the pointer movement during dt is
It is expressed by equation (4). Here, the constant C is a full scale value when 360 ° is divided at the same scale pitch with respect to the scale 100 engraved on the viscometer scale plate.

dθ = (ds / C) 2π (4) The rotation angular velocity of the pointer at an arbitrary time is represented by radian / secon
Expressed as d, ω = dθ / dt. The dθ in the equation (4) is
When converted to this expression, the expression (5) is obtained.

ω = dθ / dt (ds / dt) (2π / C) (5) In the cone and plate viscometer, the shear rate D can be calculated from the cone shape by setting the rotational angular velocity to ω and the cone angle to α (6 ) Expression.

D = ω / α (6) By substituting ω in equation (5) into equation (6), equation (7) is obtained.

D = (ds / dt) (2π / Cα) (7) The sample liquid viscosity η is defined as a ratio of the shear stress to the shear rate. That is, the basic equation of viscosity is given by equation (8).

η = (viscosity) = τ (shear stress) / D (shear rat
e) (8) By substituting D in equation (7) and τ _s in equation (3) into equation (8) and rearranging, equation (9) is obtained.

_{ds / S = (3M 100 Cα} / 4π 2 r 3 100η) dt ... than (9) (9), dlnS = (3M 100 Cα / 4π 2 r 3 100η) dt η = (3M 100 Cα / 4π 2 r 3 100) / (dlnS / dt)… (10) The numbers in parentheses are determined by the scale division specification of the full scale torque scale disk of the viscometer spiral spring, the dimensions of the cone, and the angle, so they are determined by the design of the viscometer. (11)
It can be simplified as shown in the equation. Here, K = 3M ₁₀₀ Cα / 4π ² r ³ 100 · 2.3.

η = K / dlogS / dt (11) The viscosity at an arbitrary point on the curve obtained from equation (11) as shown in FIG. 7 is obtained by drawing a straight line tangent to the point and calculating the slope of this tangent. Ask. The viscosity η can be obtained by calculation from the relationship inversely proportional to the slope dlogS / dt, as given by equation (11). In addition, the shear stress τ _{s at} this point is obtained from the equation (3), and the shear rate D is obtained from the relation of the equation (8). FIG. 7 exemplarily shows the values of the viscometer and the respective numerical values obtained from the measured data. The above is the summary of the report.

In the prior art described above, when performing viscosity measurement in an ultra-low flow region by spring relaxation, as a manipulation of the viscometer, previously rotate the spiral spring to the full-scale position by hand and push down the pointer clamp lever. In order to keep the pointer clamped, the clamp lever must be fixed with a rubber band or the like.When starting measurement, hold down the pointer clamp lever with your finger and remove the rubber band. Remove and remove your finger from the clamp lever as the standard time for the measurement start time.
It was necessary to read the scale index at required time intervals while watching the clock. This operation is not only very cumbersome,
There is a problem that two workers are required to read and record the scale while watching the time.

SUMMARY OF THE INVENTION A first object of the present invention is to provide a rotary viscometer capable of automatically measuring viscosity characteristics in an ultra-low flow region by a spring relaxation method.

A second object of the present invention is to provide a rotary viscometer capable of performing steady-state rotational viscosity measurement at a constant speed in addition to measurement by a spring relaxation method.

In order to achieve the first object, according to one aspect of the present invention, a rotor that is driven to rotate in contact with a liquid whose viscosity is to be measured, and a rotor that supports the rotor and transmits a rotational driving force to the rotor. A rotation shaft having a rotor shaft as a first drive shaft, a driving force source for rotating the rotor and an output shaft for outputting the driving force, a second drive shaft for transmitting the driving force to the rotor shaft, , A first connecting means for transmitting a driving force by elastically connecting the output shaft and the second driving shaft via the spring, and a rotor shaft rotatably bearing and supported. And a second connecting means for connecting the rotor shaft and the second drive shaft by bypassing the supporting means, the rotating viscometer comprising: Displacement detection that detects the rotational angular displacement between the motor and the rotor shaft Means and a viscosity calculating means for calculating viscosity from the obtained angular displacement, a restraining mechanism for restraining and releasing the rotation of the rotor shaft, and for separating and contacting the pivot and the bearing of the supporting means. A pivot protection means having a pivot separation mechanism, and a control means for controlling the driving of the rotation drive means and the pivot protection means. The pivot protection means restrains the rotor shaft from rotating, and controls the support means. At least a first state in which the pivot is separated from the bearing, and a second state in which the pivot of the supporting means is brought into contact with the bearing and the constraint of the rotor shaft is released, In the case of this control motor, the pivot protection means is in the first state at the start of measurement. A function of controlling to be in the second state at the time of measurement and to be in the first state at the end of measurement,
The rotational viscometer is provided with a function of controlling the torque of the spring of the first connecting means to be a preset target value at the start of measurement with respect to the rotational drive means. .

The control means, upon receiving an instruction to start measurement in a control mode for measuring viscosity by a spring relaxation method, until the first detection means detects that the pivot protection means is in the first state. The restraint mechanism and the pivot separating mechanism are driven to shift the pivot protection means to the first state. Next, when the first detecting means detects that the pivot protection means is in the first state, the rotary driving means is driven to apply the spring until the torque reaches a preset scale value. Energize. If the spring has already reached the preset target value or more, the spring is relaxed until the spring reaches the target value.

The control means drives the restraining mechanism and the pivot separating mechanism until the second detecting means detects that the pivot protecting means is in the second state at the time of measurement, thereby causing the pivot protecting means to move to the second state. The state is shifted to 2.
When the second detecting means detects that the pivot protection means is in the second state, the viscosity calculating means is activated.

After the measurement is completed, the restraining mechanism and the pivot separating mechanism are driven until the first protection means detects that the pivot protection means is in the first state, and the pivot protection means is brought into the first state. Migrate.

According to such a configuration, in the viscosity measurement in the ultra-low flow region by the spring relaxation method, the constraint of the rotor shaft, the bias of the spring,
A series of operations such as release of the constraint on the rotor shaft, measurement, and constraint on the rotor shaft after the measurement can be automatically performed. Therefore, troublesome manual operations such as a spring winding by manually turning the relaxation rotor and a clamp holding operation by the rubber band are not required.

In the present invention, the angular displacement of the rotor shaft can be detected by an angular displacement detecting means such as an angle detector, and the viscosity can be calculated from the detection result by the viscosity calculating means.
Therefore, the angular displacement at any time can be automatically read, so that the number of persons involved in the measurement can be reduced. Moreover, the operators involved prepare for the measurement,
It is only necessary to give an instruction to start the measurement, the handling is easy, and the amount of work is small, so that the operability is good. In addition, by performing the biasing of the spring while detecting the angular displacement and controlling it by the control means, the biasing amount is always constant, so that the reproducibility is good even if the measurement is repeated.

In order to achieve the second object, according to another aspect of the present invention, the control means in the above aspect further has a control mode for measuring a viscosity by rotating the rotor at a constant speed. In the case of the mode, the pivot protection means is in the second state from the start of measurement to the end of measurement,
Further provided is a function of controlling the first driving state after the measurement is completed and a function of controlling the rotation driving means to rotate the second driving shaft from the start of the measurement to the end of the measurement. A rotary viscometer is provided.

When the control means receives an instruction to start measurement in a control mode for measuring viscosity by rotating the rotor at a constant speed,
Until the second detecting means detects that the pivot protecting means is in the second state, the restraining mechanism and the pivot separating mechanism are driven to shift the pivot protecting means to the second state. When the second detecting means detects that the pivot protection means is in the second state, the rotation driving means is driven.

Further, when receiving the instruction to end the measurement, the control means stops the rotation of the rotary drive means, and the control mechanism stops the rotation until the first detection means detects that the pivot protection means is in the first state. And the pivot separation mechanism is driven to shift the pivot protection means to the first state.

According to the above state, a control mode for measuring the viscosity by the spring relaxation method and a control mode for measuring the viscosity by rotating the rotor at a constant speed can be selected, and both can be automatically measured. You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a longitudinal sectional view showing a configuration of an embodiment of a rotary viscometer of the present invention.

 FIG. 1B is an enlarged sectional view of a part thereof.

FIG. 2 is a block diagram showing a system configuration of the control device of the embodiment.

FIG. 3 is a flowchart showing the outline of the operation of viscosity measurement in the above embodiment.

FIG. 4 is an explanatory view showing the operating principle of a cone-plate type rotary viscometer.

 FIG. 5 is an enlarged view of a cone plate portion.

FIG. 6 is a longitudinal sectional view showing the configuration of a conventional cone-plate type rotary viscometer.

FIG. 7 is a graph showing an example of data of viscosity measurement in an ultra-low flow region by a spring relaxation method.

FIG. 8A is an explanatory view showing a state in which a pivot and a bearing are separated from each other and a rotor shaft is locked in a rotary viscometer to which the present invention is applied.

FIG. 8B is an explanatory view showing a state in which the pivot and the bearing are in contact with each other and the rotor shaft is released in the rotary viscometer to which the present invention is applied.

FIG. 9A is a state transition diagram of a measurement operation at a constant rotation speed in the viscometer of the above embodiment.

FIG. 9B is a state transition diagram of a measurement operation by a spring relaxation method in the viscometer of the above embodiment.

FIG. 10 is a flowchart showing a viscosity measuring operation by the spring relaxation method of the above embodiment.

FIG. 11 is a flowchart showing a viscosity measurement operation at a constant rotation speed in the above embodiment.

FIG. 12 is a flowchart showing an end operation for viscosity measurement by the spring relaxation method of the above embodiment.

FIG. 13 is a flowchart showing an end operation of the above embodiment for measuring viscosity at a constant rotation speed.

FIG. 14 is a block diagram showing the configuration of another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described. Note that the present invention is not limited to the following embodiments.

FIG. 1A shows an outline of an embodiment of the rotational viscometer of the present invention. FIG. 1B shows a partial structure thereof.

As shown in FIG. 1A, a rotational viscometer of the present invention includes a plate 7a for holding a sample liquid, and a jacket surrounding the plate 7a and flowing a liquid for holding the sample liquid at a constant temperature.
17, a cone-shaped rotor 6a, a rotor shaft 5b (first drive shaft) for holding and rotating the cone-shaped rotor, and driving the rotor 6a via the rotor shaft 5b and measuring the viscosity. It includes a main body 100 and a pivot protection device 200 that constitutes a pivot protection means between the main body 100 and the rotor 6a.

The main body 100 includes a drive motor 21, a rotary joint 25, and an output shaft 22, which constitute a rotary drive unit, a second drive shaft 5c having a lower end connected to the rotor shaft 5b in the pivot protection device 200, First connecting means 400 for elastically connecting the output shaft 22 and the second drive shaft 5c; and the output shaft 22 and the second drive shaft 5c.
c and a rotary differential transformer 23 functioning as an angular displacement detecting means.

The first connecting means 400 includes an L-shaped member 4b, one end of which is connected near the lower end of the output shaft 22, and the other end of the L-shaped member 4b.
And a spiral spring 4a which is disposed between the driving shaft 5c and the connecting shaft 5c to elastically connect them. Also, the first connecting means 400
Is a sleeve 10b having one end on the L-shaped member 4b and the other end
And an arm member 4d for transmitting the rotational driving force of the output shaft 22 to the sleeve 10b.

The output shaft 22 and the second drive shaft 5c are rotatably mounted between the output shaft 22 and the second drive shaft 5c in holes (not shown) provided on respective end faces of the output shaft 22 and the second drive shaft 5c. A pin 13a is provided to stop the steady movement. Output shaft 22 and second drive shaft 5
The holes (not shown) provided on each end face of c have a depth that allows a slight axial displacement of the pin 13a, that is, the rotor shaft 5b.
And a pin 13a corresponding to the axial displacement of the second drive shaft 5c.
Is provided so as to secure a depth capable of absorbing the axial displacement.

The pivot protection device 200 includes a pivot 11 and a bearing 12 that constitute support means for rotatably bearing and supporting the rotor shaft. The pivot protection device 200 bypasses the pivot 11 and the bearing 12 so that the rotor shaft 5b and the second A channel-type connecting member 10a functioning as a second connecting means for connecting the drive shaft 5c, a restraining mechanism and a pivot separating mechanism functioning as a pivot protecting means to be described later, and first and second detecting states of the pivot protecting means. There are provided limit switches 31 and 32 functioning as a second detecting means and an L-shaped metal fitting 30 for turning on and off the limit switches 31 and 32, and these are housed in a case 27 except for a part.

The pivot 11 is attached to a lower end of the second drive shaft 5c. On the other hand, the bearing 12 is mounted on the lower side 10d of the channel-type member 10c mounted on the lower end of the sleeve 10b provided around the second drive shaft 5c. The pivot 11 and the bearing 12 are mounted coaxially. The sleeve 10b is rotatably supported by a flange 27a above the case 27.
The arm member 4d is connected to the upper end of the sleeve 10b as described above.

In the case 27, as shown in FIGS. 1A and 1B,
A sleeve 28 is accommodated so as to be displaceable in the axial direction. A screw portion 28a is provided at a lower portion of the inner surface of the sleeve 28, and a disk 41 is screwed to the screw portion 28a. In the center of the disk 41, a through hole 41a through which the rotor shaft 5b can freely pass is provided. On the upper surface of the disc 41, a first engagement member, for example, an internal gear 42 is provided. A second engaging member that engages with the internal gear 42, for example, the external gear 40 is provided on the rotor shaft 5b.

When the internal gear 42 is displaced along with the axial displacement of the sleeve 28, the external gear 40 meshes with the internal gear 42, and further comes into contact with the displaced disk 41, so that the external gear 40 itself, together with the rotor shaft 5b, Is attached to the rotor shaft 5b so as to be displaced.

At the upper part of the sleeve 28, a block 33 provided with a screw hole 33a is attached. On the other hand, the flange 27a
The lock motor is located at a position facing this block 33.
34 are located. The motor 34 is provided with a screw shaft 34a having a screw as an output shaft. The screw shaft 34a is screwed into the screw hole 33a of the block 33. The lock motor 34 rotates the screw shaft 34a forward or backward to displace the block 33 upward or downward. The sleeve 28 is displaced in the axial direction with the displacement of the block 33.

The displacement stroke of the sleeve 28 is
It is set to the length required to separate 12 from. That is, the internal gear 42 is displaced to engage with the external gear 40, and further, the disk 41 is brought into contact with the external gear 40, and this external gear
The length is set so that the pivot 11 can be separated from the bearing 12 by pushing up 40.

One side of the L-shaped bracket 30 is attached to the upper part of the sleeve 28. In the L-shaped bracket 30, the other side 30a projects outside the sleeve 28, and the above-described limit switch 3
It is arranged to be located between 1,32. That is, one side
30a is arranged so as to be displaced in accordance with the axial displacement of the sleeve 28, to turn on the limit switch 31 at the upper limit of the displacement, and to turn off the limit switch 32 at the lower limit of the displacement. Therefore, the limit switches 31 and 32 are arranged at intervals corresponding to the displacement stroke of the sleeve 28, including the drive stroke of one of the switch units.

The control device 35 is configured, for example, as shown in FIG. The control device 35 shown in FIG. 2 is connected to the viscometer main body 100, and is a drive control unit for transmitting and receiving measurement data and control signals.
360, an information processing unit 350 for processing measurement data from the drive control unit 360, controlling the operation of the drive control system, and the like, and an input / output unit 370 for inputting and outputting information to and from the information processing unit 350.

An information processing unit 350, a central processing unit (CPU) 351 for performing control for viscosity measurement and processing of measurement data,
A memory 352 for storing programs executed by the U351, various data, processing results, etc., a data bus 353, measurement data,
An interface board (IB) 354 for controlling input / output of control signals and the like and an input / output interface 355 are provided.

The memory 352 mainly includes a ROM (read only memory) for storing programs and a RAM (random access memory) for storing data. The stored program includes, for example, a program that executes the following procedure.

First, there are the following procedures for measuring the viscosity by the spring relaxation method.

An instruction to start measurement in a control mode for measuring viscosity by a spring relaxation method is received; a restraining mechanism and a pivot separating mechanism until the first detecting means detects that the pivot protection means is in the first state. To move the pivot protection means to the first state; when it is detected that the pivot protection means is in the first state, the rotation driving means is driven to change the biased state of the spring to that state. Setting the torque to a preset target value; driving the restraining mechanism and the pivot separating mechanism until the second detecting means detects that the pivot protecting means is in the second state; To the second state; when it is detected that the pivot protection means is in the second state, the viscosity calculation means is activated to execute the viscosity measurement; Until the detecting means detects that the pivot protection means is in the first state, the restraining mechanism and the pivot separating mechanism are driven to shift the pivot protection means to the first state; The procedure for measuring the viscosity by rotation is as follows.

An instruction to start measurement in a control mode for measuring the viscosity by rotating the rotor at a constant speed is received. In response to the instruction, the restraining mechanism and the pivot separating mechanism are operated.
The driving is performed until the second protection means detects that the pivot protection means is in the second state. When the second detection means detects that the pivot protection means is in the second state, the restraining mechanism is used. And stopping the driving of the pivot separating mechanism and driving the rotation driving means; receiving an instruction from the outside to finish the measurement; stopping the driving of the rotation driving means in response to the instruction; The driving of the pivot protection means is detected by the first detection means to be in the first state; specific examples of these procedures are described in, for example, FIG.
This is shown in FIG. 10, FIG. 11, FIG. 12 and FIG.

The drive control unit 360 includes a rotation drive motor drive circuit 361 that drives the rotation drive motor 21 to rotate, a rotation drive motor interface 362 that outputs a control signal from the information processing unit 350 to the drive circuit 361, and a lock motor. 34, a lock motor interface 364 that outputs a control signal from the information processing unit 350 to the lock motor drive circuit 363, and an on / off signal of the limit switches 31 and 32. , An A / D converter 366 which converts the measured value of the rotary differential transformer 23 from analog to digital and sends it to the information processing unit 350, and an external device such as a computer system 390. An input / output interface 367 for connection. The computer system 390 includes, for example, a central processing unit (CP
U) 391, printer 392, memory 393, etc. are included.

The input / output unit 370 includes, for example, a keyboard 371 for externally executing / stopping instructions and inputting data to the control device 35, and a data display for displaying information output from the information processing unit 350. 372, a status display 373, and a mode display 374.

The keyboard 371 has a numeric keypad 371a for entering numbers,
It includes an execution / stop switch 371b for instructing execution / stop, and mode selection keys 371c and 371d. Mode selection key 37
1c selects the conventional viscosity measurement mode (ORD.MODE) by rotating the rotor at a constant speed, and 371d selects the viscosity measurement mode (SRMODE) by the spring relaxation method.

The data display 372 displays the measured viscosity and the rotation speed of the rotor by numbers. As the display element, for example, a numerical display element such as a light emitting diode is used.

The status display 373 has five display units 373a to 373e for indicating the state of the viscometer. These are, for example, light emitting diodes. Display 373a
Is stopped (STOP), 373b is locked (LOCKING), 373c is released (RELEASING), 373d is running (RUN), and 373e is measured (MEAS
URING) and corresponding to the state of the viscometer,
Each emits light.

The mode display 374 has a conventional viscosity measurement mode display (ORD.MODE) 374a by rotating the rotor at a constant speed and a viscosity measurement mode display (SRMODE) 374b by the spring relaxation method.

The pivot protection device 200 restrains the rotor shaft 5b and separates the pivot 11 from the bearing 12 in a first state.
A second state in which the constraint of 5b is released.
The control device 35 controls the driving of the lock motor 34 so that the pivot protection device 200 is brought into a target state in accordance with an instruction from the outside, and controls the driving of the rotary drive motor 21 in accordance with the state. I do.

Next, regarding the operation of the present embodiment, in addition to the above-described drawings,
This will be described with reference to FIGS. 3, 9A, 9B, 10, 10, 11, 12, and 13. FIG.

As shown in FIGS. 9A and 9B, the state of the rotational viscometer of this embodiment changes according to a series of sequences. 9A and 9B, “0” indicates a stopped state of the viscometer. At this time, the pivot 11 and the bearing 12 are separated from each other, and the rotation of the rotor shaft 5b is restricted. This state is the first state. “1” indicates a state in which the constraint on the rotor shaft 5b is released. “2” indicates that the viscometer rotates and is in a measurement state. In this case, the pivot 11 and the bearing 12 are in contact, and the rotor shaft 5b is released from the constraint. This state is the second state. “3” indicates a state in which the rotation of the rotor shaft 5b is restricted. Also, in FIG. 9B, “A”
Indicates that the device is in a spring up / up operation state. “B” indicates a spring relaxation measurement state.

 Next, this series of operations will be described.

First, the outline of the measurement operation of the viscometer of the present embodiment,
This will be described with reference to FIG.

At the start of measurement, when the power of the control device 35 is turned on (step 1001), the CPU 351 checks whether or not the contact of the limit switch 31 is on (step 1002). This can be known from a signal from the limit switch interface 365. If the limit switch 31 is off, the lock motor drive circuit 363 is instructed via the lock motor interface 364 to drive the lock motor 34 in a direction to raise the sleeve 28 (step 100).
3). At this time, the CPU 351 turns on the display unit 373b until the limit switch 31 is turned on. On the other hand, if the limit switch 31 is on, the lock motor 34 is not driven.

When the lock motor 34 is driven, the screw 34a rotates. With the rotation of the screw 34a, the block 33 screwed with the screw 34a is displaced in the axial direction, and the sleeve 28 to which the block 33 is fixed rises. When the sleeve 28 rises, the sleeve 28
The disk 41 fixed to is raised. As the disk 41 rises, the internal gear 42 provided on the disk 41 meshes with the external gear 40 fixed to the rotor shaft 5b. This allows
The rotation of the rotor shaft 5b is restricted by the sleeve 28. In addition, the disk 41 pushes up the external gear 40 by further raising the sleeve 28 slightly. Along with this, the rotor shafts 5b and 5c are pushed up, and the pivot 11 moves up and separates from the bearing 12. FIG. 8A shows this state.

By this operation, the rotor shaft 5b is in the restrained state, and the pivot 11 and the bearing 12 are in the separated state. Further, the constraint of the rotor shaft 5b and the separation between the pivot 11 and the bearing 12 are also performed at the end of the measurement, as described later.

Next, the measurement mode is determined (step 1004).
The measurement mode determination is performed by checking which of the mode selection keys 371c and 371d has been selected. If the spring relaxation method is selected, a spring relaxation viscosity measurement is performed (step 1005). On the other hand, if the viscosity measurement by the constant speed rotation is selected, the measurement is executed (step 1007). And when each measurement is finished,
Execute the end operation (steps 1006 and 1008),
The measurement operation ends.

Next, the viscosity measurement operation by the spring relaxation method will be described with reference to the flowchart of FIG.

First, an input of a measurement execution instruction is received (step 15
01). In response to the execution instruction, the CPU 351 sets the spring 4a to the target peak value biased state. In this state, since the rotor shaft 5b is in the constrained state, when the rotation driving pulse motor 21 is rotationally driven, the spring 4a is wound up or unwound, and the biased state changes.

In the measurement by the spring relaxation method according to the present embodiment, the winding speed of the spring is not directly related to the measurement. However, a low speed is selected in order to reduce the variation in the stop position when stopping after completing the hoisting. For example, in practice, the speed can be about 5 rpm. Further, the speed of the pulse motor 21 can be changed according to the instruction. The speed can be changed, for example, by changing the pulse rate of the pulse train drive signal. The speed instruction is, for example, registered in the RAM in advance, and based on this,
By sending a speed command to the rotation drive motor drive circuit 361. Further, the rotation drive motor drive circuit 361 may be provided with an instruction function for speed setting.

When adjusting the biasing state of the spring, the winding angle θ of the spring is
The A / D converter 366 is detected by the rotary differential transformer 23.
Is converted to a digital value and sent to the CPU 351.
The CPU 351 compares the spring winding angle θ with the target peak value Θ (step 1502), and activates the rotation drive pulse motor drive circuit 361 according to the result, and rotates the rotation drive pulse motor 21. Control. Here, if θ> バ ネ, since the spring 4a is in a state of being wound up to a target value or more, the pulse motor 21 is reversely rotated so as to wind up the spring 4a (step 1503). On the other hand, if θ <Θ, the spring
Since 4a is not being wound up to the target value,
The pulse motor 21 is normally rotated so that the spring 4a is wound up to the target value (step 1504).

Here, the target peak value Θ is, for example,
Can be input using the numeric keypad 371a. The input value is stored, for example, in a RAM together with information on mode selection. The CPU 351 performs various determinations with reference to the information in the RAM.

In the case of θ> Θ, the spring 4a may be completely wound up once, and then again wound up to the target peak value. Further, after the measurement is completed, the spring 4a may be automatically wound back.

When θ = Θ, the CPU 351 does not drive the pulse motor 21 but activates the lock drive motor drive circuit 363 to control the lock drive motor 34 to be driven in the release direction (step 1506). The CPU 351 continues this release operation until the limit switch 32 is turned on (step 1507), and turns on the display 373c.

That is, in the release operation, together with the lock operation, the lock drive motor 34 is moved so that the sleeve 28 is lowered.
Is drive-controlled. When the lock motor 34 is driven,
The screw 34a rotates. With the rotation of the screw 34a, the block 33 screwed with the screw 34a is displaced in the axial direction, and the sleeve 28 to which this is fixed is lowered. When the sleeve 28 descends, the disk 41 fixed to the sleeve 28 descends. With the lowering, the external gear 40 pushed up by the disk 41 lowers, and the pivot 11 lowers and comes into contact with the bearing 12. Further, the internal gear 42 and the external gear 40 are disengaged from each other, whereby the restriction of the rotor shaft 5b by the sleeve 28 is released. FIG. 8B shows this state.

When the limit switch 32 is turned on, the release operation is stopped, and the spring relaxation measurement is performed. At this stage, 8B
As shown in the figure, the rotor shaft 5b is in a rotatable state,
At the same time, the pivot 11 and the bearing 12 are in contact with each other. In this measurement, the rotor 6a rotates while being driven against the viscosity torque of the sample liquid by the relaxation torque of the spring 4a. This rotation is detected by the rotary differential transformer 23. CPU351
Samples the rotation angle displacement data from the rotary differential transformer 23 via the A / D converter 366 as spring relaxation data at a predetermined cycle (step 1508).

During this time, the CPU 351 determines the elapsed time t since the measurement start time.
Is compared with a predetermined sampling period T (step 1509). If t <T, the measurement operation is continued, and the display unit 373e is turned on during that time. When t ≧ T, the measurement is terminated by outputting the measurement end signal (step 1510).

The sampling period and sampling period are
It can be registered in advance using the keyboard 371. The sampling period is selected, for example, from one to several seconds. The sampling period is, for example, from 10 minutes.
Selected for about 20 minutes. This registration is performed, for example, in the memory 352.
Can be done with RAM. The elapsed time t is, for example,
It can be obtained by providing a timer for displaying the elapsed time. Further, the sampling period T may be set in advance by, for example, providing a timer. in this case,
The comparison with t is not required, and the measurement is ended when the end signal is output from the timer.

The spring relaxation data is stored in, for example, the RAM of the memory 352, and the CPU 351 performs a calculation for obtaining the viscosity based on the data. The result is stored in the RAM and displayed on the data display 372.

Note that the measurement data may be sent to the computer system 390 and temporarily stored in the memory 393, and the CPU 391 may calculate the viscosity based on this data. In this case, the computer system printer 39
2 can be printed out. Further, it can be displayed in the form of numerical values, charts, and the like on a display (not shown).

Thereafter, a measurement end operation is performed. This action is
As shown in the figure, first, a stop instruction is received (step
1601). This stop instruction uses the above-mentioned measurement end signal in the case of the measurement by the spring relaxation method. Upon receiving the stop instruction, the CPU 351 causes the lock drive motor drive circuit 363 to drive the lock drive motor 34 in a direction to restrain the rotor shaft 5b, that is, in a direction to raise the sleeve 28 (step 1602). This is continued until the contact of the limit switch 31 is turned on (step 1603). During this time, the display unit 373b is turned on. Then, when the limit switch 31 is turned on, the drive of the lock drive motor 34 is stopped, and the display unit 373a is turned on.

Thus, a series of operations for measuring the viscosity by the spring relaxation method is completed.

Next, regarding the viscosity measurement operation at a constant rotation speed, the eleventh
This will be described with reference to the flowchart in FIG.

First, an input of a measurement execution instruction is received (step 17).
01). In response to the execution instruction, the CPU 351 instructs the lock motor 34 to be driven in a direction to lower the sleeve 28 (step 1702). This release operation is continued until the limit switch 32 is turned on. During this time, the CPU 351 turns on the display unit 373c. When the limit switch 32 is turned on, the release operation stops and the display
373d is turned on (step 1703). Then, it instructs the rotation drive motor drive circuit 361 to rotate the rotation drive motor 21 via the rotation drive motor interface 362 (step 1704). As described above, the rotation speed can be specified and changed, as described above.

In this state, the viscosity is measured. The measurement is performed by detecting the angular displacement between the output shaft 22 and the second drive shaft 5c with the rotary differential transformer 23 using the rotary differential transformer. The detected value of the rotary differential transformer 23 is the A / D converter 366
Is converted to a digital value by the interface board 354
Is sent to the information processing unit 350 via

The measurement data is stored in, for example, the RAM of the memory 352, and is processed by the CPU 351. The processing result is displayed on the data display 372 together with the separately determined rotational speed of the rotor.

Also in this case, the measurement data may be sent to the computer system 390 and temporarily stored in the memory 393, and the CPU 391 may calculate the viscosity based on this data. In this case, printing can be performed by the printer 392 of the computer system. Further, it can be displayed in the form of numerical values, charts, and the like on a display (not shown).

Next, the operation of the viscometer at the end of measurement will be described with reference to the flowchart shown in FIG.

First, a stop instruction is received while the rotary drive motor is rotating and the display unit 373d is lit (step
1801). This stop instruction is performed by inputting a stop operation by the execution / stop switch 371b. When the stop is commanded, the CPU 351 sends the rotation drive motor 2 to the rotation drive motor drive circuit 361 through the rotation drive motor interface 362.
Instruct 1 to stop (step 1802).

Next, the CPU 351 sets the lock motor interface 364
To the lock motor drive circuit 363 via the sleeve 2
An instruction is issued to drive the lock motor 34 in a direction to raise the position 8 (step 1803). And limit switch
This lock operation is continued until 31 is turned on. During this time,
The CPU 351 turns on the display unit 373b. Limit switch
When 31 is turned on, the locking operation is stopped and the display unit 373a is turned on (step 1804).

Thus, a series of operations of the viscosity measurement by the constant speed rotation is completed.

In the state after the end operations 1006 and 1008 shown in FIG. 3 are executed, the rotation of the rotor shaft 5b is restricted. Further, the pivot 11 and the bearing 12 are in a separated state. Therefore,
Even when operations such as cleaning and replacement of the rotor 6a are performed, damage to the pivot can be prevented. In addition, since the pivot protection is automatically executed in series in response to only the instruction of the end of the measurement, the user does not forget to lock and wash the rotor. Further, in this embodiment, since the state of the viscometer is displayed, the user can easily grasp the operating state of the viscometer, thereby preventing an erroneous operation from being performed.

Further, in the present embodiment, since the rotation drive motor is not driven while the lock motor is driven, the lock operation or the release operation and the viscosity measurement operation are prevented from being performed simultaneously.

Next, another embodiment of the present invention will be described with reference to FIG.

The embodiment shown in FIG. 14 is an example using a viscometer having the same viscometer main body 100 and pivot protection device 200 as the above-described embodiment, and the configuration of the control device is different from the control device of the above-described embodiment. With the exception of
Works similarly. Therefore, the following description focuses on the differences.

The control device according to the present embodiment uses a hardware logic circuit to control that the control device according to the above-described embodiment executes control using software using a computer.

In FIG. 14, this embodiment drives a pulse generator 301 for generating a drive signal, a sampling time timer 304 for determining a sampling time, and a rotor driving motor (see FIG. 1A) in the viscometer main body. Circuit 303 for performing automatic locking of the rotor shaft as in the case of FIG. 1A described above.
And an A / D converter 3 for converting a rotational angular displacement between the rotor and the drive motor detected by the rotary differential transformer into a digital value.
06, a comparator 307 that outputs a winding stop command signal when the rotation angle displacement reaches a preset winding finger index and outputs a rotation direction identification signal, and a signal from the pulse generator 301 and the comparator 307. A switch circuit 302 for switching whether or not to input a drive pulse of a pulse generator 301 to a driver circuit 303 in accordance with a signal; a signal processing device 308 for obtaining viscosity based on rotational angular displacement; and an output from the signal processing device 308. And a display unit 309 for displaying. To this, further computer systems 390 can be connected. The computer system 390 includes, for example, a CPU 391, a printer 392, and the like. FIG. 14 shows a constant temperature bath 38 for supplying a liquid for keeping the sample liquid at a constant temperature. It goes without saying that this can be connected to the embodiment shown in FIG. 1A.

The viscosity measurement in the ultra low speed flow region by the spring relaxation according to the present embodiment is performed by the rotor shaft automatic lock device 305,
Utilizing the fact that 1 is separated from the bearing 12 and is inhibited in the rotation direction at the same time as being unable to rotate, the pulse motor 21 is rotated at a constant speed while the rotor shaft 5b is locked, and the spiral spring 4a is wound up. (See Fig. 8A). Since this speed is the hoisting speed, the speed does not directly relate to the spring relaxation measurement, but when the hoisting is completed and stopped,
Select a low speed to reduce the variation of the stop position.

At this time, as the spiral spring 4a is wound up, the output shaft
Since the amount of angular displacement between 22 and the rotor shaft 5b increases, a digital value obtained by A / D-converting the output signal of the angle detector 23 is input to the comparator 307, and the desired winding value set manually by a key switch in advance is set in advance. Find the difference between When this value becomes 0 and the desired winding amount is reached, the winding is completed by stopping the pulse motor 21 (see FIG. 8A). Next, by releasing the rotor shaft lock, the rotor 6a is driven by the relaxation torque of the spiral spring 4a and driven to rotate against the sample liquid viscosity torque. The temporal change in the amount of angular displacement, that is, the change in the fingering degree from the release of the rotor shaft lock, is processed by the signal processing device 308, so that the viscous behavior of the sample liquid in the ultra-low flow region can be analyzed. The result can be displayed by the display 309.

After the time set in the sampling time timer 304 elapses, the timer 304 issues a rotor shaft lock command signal, activates the rotor shaft automatic lock device 305, locks the rotor shaft 6a, and stops the viscometer. Return to the state and end the measurement.

According to the configuration of the present invention, the viscosity measurement for analyzing the viscosity characteristics of the sample liquid in the ultra-low flow rate region by the above-described spring relaxation can also be automatically performed sequentially except for the operation of charging the viscometer of the sample liquid. .

In each of the above embodiments, the displacement of the sleeve is performed by the lock motor. However, the present invention is not limited to this. For example, a linear motor, a solenoid, or the like can be used as an actuator. The limit switch is not limited to a macro switch, but may be an optical switch, a magnetic switch, a pressure-sensitive switch, or the like.

The present invention is not limited to the above-described embodiment, but may be implemented by another mode that performs a similar function. In addition, various changes and additions can be made to the present invention within the scope of the technical idea disclosed above.

Claims (13)

(57) [Claims] 1. A rotor which is driven to rotate in contact with a liquid whose viscosity is to be measured, a rotor shaft which is a first drive shaft that supports the rotor and transmits a rotational driving force to the rotor, and drives the rotor to rotate. A driving force source for outputting the driving force, a rotation driving means having an output shaft for outputting the driving force, a second driving shaft for transmitting the driving force to the rotor shaft, and a spring. First connecting means for elastically connecting the second drive shaft and the second drive shaft to transmit a driving force; supporting means having a pivot and a bearing for rotatably bearing and supporting the rotor shaft; A rotational viscometer that includes a second connecting unit that connects the rotor shaft and the second drive shaft by bypassing the support unit, wherein the angular displacement detecting unit detects a rotational angular displacement of the rotor shaft, and Viscosity to calculate viscosity from the obtained angular displacement Calculating means, a restraining mechanism for restraining and releasing the rotation of the rotor shaft, and a pivot protecting means having a pivot separating mechanism for separating and contacting the pivot and the bearing of the supporting means; and A driving means and a control means for controlling the driving of the pivot protection means, wherein the pivot protection means restrains the rotor shaft from rotating and separates the pivot of the support means from the bearing; A second state in which the pivot of the support means is brought into contact with the bearing and the constraint of the rotor shaft is released, and the control means has a control mode for measuring the viscosity by a spring relaxation method. In the mode, the pivot protection means is in the first state at the start of the measurement, in the second state at the start of the measurement, and at the end of the measurement at the start of the measurement. (1) a function of controlling the rotation drive means so that the torque of the spring of the first connection means becomes a preset target value at the start of measurement. Rotary viscometer characterized by the following. 2. The rotary viscometer according to claim 1, wherein said control means further comprises a control mode for measuring viscosity by rotating said rotor at a constant speed, and in this mode, said pivot protection means. On the other hand, from the start of measurement to the end of measurement, a function of controlling to be in the second state, and after the end of measurement, to be in the first state. Up to a function of controlling the second drive shaft to rotate. 3. The rotary viscometer according to claim 1, wherein said control means is a control mode for measuring the viscosity by a spring relaxation method in accordance with a mode selection signal, and a control mode for rotating the rotor at a constant speed. Is executed in one of the control modes for measuring. 4. The rotary viscometer according to claim 1, wherein first detecting means for detecting that the pivot protection device is in a first state, and wherein the pivot protection device is in a second state. And second detection means for detecting 5. A rotary viscometer according to claim 4, wherein said control means is a control mode for measuring viscosity by rotating a rotor at a constant speed, and said second detection means is configured to:
On the condition that the pivot protection means detects that the pivot protection means is in the second state, it has a function of controlling the rotation drive means to rotate. 6. A rotary viscometer according to claim 4, wherein said control means is a control mode for measuring viscosity by a spring relaxation method, and said first detection means is provided with a pivot protection when starting measurement. It has a function of controlling the rotation driving means to rotate in a condition that the means detects that the means is in the first state. 7. A rotary viscometer according to claim 4, wherein said control means receives a command to start measurement in a control mode for measuring viscosity by a spring relaxation method, and pivots said first detection means. Means for executing a procedure of driving the rotation driving means to adjust the torque of the spring until a predetermined value is reached, provided that the protection means is detected to be in the first state. At the time of measurement, the restraining mechanism and the pivot separating mechanism are driven to shift the pivot protection means to the second state until the second detection means detects that the pivot protection means is in the second state. When the second detecting means detects that the pivot protection means is in the second state, means for executing a procedure for activating the viscosity calculating means, and after the measurement is completed, the first detecting means performs the pivoting operation. Means for driving the restraining mechanism and the pivot separating mechanism to shift the pivot protection means to the first state until it is detected that the pivot protection means is in the first state. 8. The rotary viscometer according to claim 7, further comprising display means for indicating an operation state. 9. The rotary viscometer according to claim 4, wherein said control means receives a command to start measurement in a control mode for measuring viscosity by rotating the rotor at a constant speed. By driving the restraining mechanism and the pivot separating mechanism until the pivot protection means is detected to be in the second state, the pivot protection means is shifted to the second state.
Detecting that the pivot protection means is in the second state by the detecting means, means for executing a procedure for driving the rotation driving means, and upon receiving an instruction to end the measurement, stops the rotation of the rotation driving means. And performing a procedure of driving the restraining mechanism and the pivot separating mechanism to shift the pivot protection means to the first state until the first detection means detects that the pivot protection means is in the first state. Means. 10. The rotary viscometer according to claim 9, wherein
There is further provided a display means for indicating an operation state. 11. A rotary viscometer according to claim 1, wherein said first connecting means has a spiral spring for elastically connecting said rotary drive means and a second drive shaft. 12. The rotary viscometer according to claim 1, wherein the angular displacement detecting means has a rotary differential transformer and electrically detects the angular displacement. 13. The rotary viscometer according to claim 1, wherein a torque of a spring of the first connecting means is set to a preset target value at the time of starting measurement with respect to the rotary driving means of the control means. Such a control function includes both a case where the spring torque is made larger than the current value and a case where the spring torque is made smaller.