JPS63317744A - Rotary viscosimeter - Google Patents

Abstract

PURPOSE:To measure the value of the viscosity of a viscosity sample, by driving and rotating an outer rotary body, moving the viscosity sample with a spiral groove, which is formed in an inner static columnar body, and measuring rotary torque, which is applied on the inner columnar body. CONSTITUTION:An outer rotary cylinder body 15 is provided, with a minute gap part 14 being kept with respect to an inner static columnar body 13. When the rotary cylinder body 15 is driven and rotated with a geared motor 17, a viscosity sample, which is introduced through a fluid inlet port 12, is moved and discharged through a fluid discharge port 16 by way of a spiral groove 11 in the rotary cylinder body 15. At this time, rotary torque is generated in the static columnar body 13 by the viscosity resistance of the fluid. Therefore, the columnar body 13, which is coupled to a fixed side 3 with a spring 4, is rotated against the elasticity of the spring up to a balancing position with the viscosity rotating force of the fluid. At the same time, a viscosity-value display pointer 10 is rotated. Thus the viscosity value of the viscosity sample can be found by reading the position of the pointer 10 with a viscosity-value displaying scale plate 22.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable not only when the target fluid is a Newtonian fluid but also when the fluid has non-Newtonian fluid properties.
Regarding rotational viscometers that can accurately measure the viscosity even if the amount is small, it is possible to specify the viscosity by keeping the shear time and shear rate constant. The present invention relates to a rotational viscometer that is configured to enable accurate management of viscosity values and that is suitable for portable use and can be constructed in a small size and at low cost.

2. In the present invention, a paste with the properties of a non-Newtonian fluid is used as the fluid, in order to achieve a very large effect in measuring the viscosity of non-Newtonian fluids, which has traditionally been difficult to obtain accurate viscosity values. Although the explanation will focus on paste, it goes without saying that other fluids may be used instead of paste.

[Prior art and its problems] In today's era of co-electronics, demands for higher density and more complex electronic devices are increasing.

Hybrid microelectronics technology responds to these demands by mounting a combination of active elements with various functions and passive elements such as resistors and capacitors on a substrate to create light, thin, short, and small hybrid modules.

In the manufacturing process of a hybrid IC, the first step is a printing process on a substrate. As for printing.

Use a screen printing machine. Depending on the screen printing machine, various pastes (conductive paste, resistive paste, dielectric paste, solder paste, etc.) can be printed.

Resist ink and other functional material inks are printed on the substrate mainly by screen printing.

This printing requires high precision due to the nature of the hybrid IC. In such printing, the accuracy of the printed film thickness and the accuracy of the printed pattern are largely dependent on the functions of the screen printing machine, and are determined by the accuracy of the screen printing machine.

The most important and difficult management element for improving printing accuracy is managing the viscosity of the paste (ink) itself.

Due to the difficulty of controlling the viscosity of this paste, the current situation is that in most cases, it relies on the experience of printing engineers and laboratory measurements.

The difficulty in controlling the viscosity of pastes is that many pastes have non-Newtonian fluid properties and thixotropy, so they not only depend on ambient conditions such as temperature and humidity, but also due to This is also due to the fact that the viscosity is not constant even after kneading.

Therefore, after kneading the paste, measure the viscosity of the paste using a viscometer, supply the paste with a predetermined viscosity value to a screen printing machine, and even if it is printed on a substrate, the viscosity will change from moment to moment. The viscosity of the paste during printing is unstable, making it impossible to perform elaborate screen printing.

Moreover, during printing, the paste is further kneaded with a squeegee (corresponding to a "spatula" for applying the paste), so the viscosity of the paste becomes even more unstable, making it impossible to perform elaborate screen printing.

Conventionally, the viscometer used in screen printing is a rotating type in order to knead the viscosity of the paste stored in a tank, and the viscometer is designed to extract this rotational resistance as a viscosity value. It was relatively large and expensive.

This kind of rotational viscometer measures the viscosity of paste in a tank in a laboratory setting, and it is impossible to measure it directly on a screen printing machine, making it difficult to accurately measure and control the viscosity of paste. Therefore, elaborate screen printing cannot be achieved.

Also, as mentioned above, paste has the properties of a non-Newtonian fluid, but the viscosity of this non-Newtonian fluid changes greatly depending on the temperature, and the speed of the paste with the rotating body (shear rate) and shear time. Viscosity changes significantly.

For this reason, in the past, the viscosity of the paste was always measured using a stop watch at a fixed unit time, such as 5 minutes, for example, 3 minutes.

According to this method, it seems possible to measure the viscosity accurately, but in the case of fluids such as pastes that also have non-Newtonian fluid properties, it is difficult to know the exact viscosity value. This is impossible, and a different viscosity value is obtained each time it is measured.The current situation is that no sophisticated viscometer has appeared even in the long history of dozens of volumes.For this reason, viscosity values are used as a guideline. It is acknowledged by academic societies and experts that it was not possible to know the exact viscosity value because the viscosity value had to be dealt with.

In addition, according to this method, viscosity measurements have to be repeated many times, making it difficult to measure the paste continuously, making it impossible to perform automated measurements, resulting in low production efficiency and the inability to accurately measure viscosity. It has the disadvantage of being troublesome.

This is because the shear time cannot be kept constant or the viscosity cannot be determined.

Yet again. Due to various factors such as the measurer and external conditions, it has not been possible to accurately control the viscosity of a non-Newtonian fluid such as paste.

In order to keep the shear time constant, attempts have been made to forcibly circulate the paste using a pump or the like and measure the viscosity of the paste, but this method has the following drawbacks: .

a1 The mechanism for forced circulation is complicated, and the device itself is large and expensive.

b. The disadvantage of a above is that the viscosity of the paste cannot be easily measured.

According to the C1 forced circulation, the force exerted by this affects the rotational torque obtained when trying to measure the viscosity of the paste, resulting in the drawback that the viscosity of the paste cannot be measured accurately and with good precision.

d. Also, if a falling forced circulation method is adopted,
This method has the disadvantage that the shear time cannot be kept constant, and the viscosity cannot be measured accurately as described above.

Furthermore, the forced circulation force type has the disadvantage that the passage for circulating the paste becomes large, and therefore the rotational viscometer itself becomes large and expensive.

[Problems to be solved by the invention] In order to meet the demand for higher precision in screen printing, the present invention aims to provide a rotational viscometer that is small, highly accurate, suitable for such portable devices, and can be constructed at low cost, and also to provide a rotational viscometer that can be constructed at low cost. By making it possible to keep the sliding time and speed of a fluid such as a paste constant even during crosstalk, the viscosity of the paste can be determined, and the viscosity of the paste can be determined each time. The object of the present invention is to provide a rotational viscometer that can automatically measure and manage accurate viscosity values of fluids such as paste without using a stopwatch each time.

In particular, for non-Newtonian fluids such as pastes, the viscosity generally changes when a friction stress is applied, and the viscosity also changes due to the friction of a one-turn viscometer, so it is necessary to specify the measurement time and determine the measured value. However, regarding this point, in the rotational viscometer of the present invention, the paste is automatically sucked up by the rotation of the cylinder, etc., which is a rotating body, and when the sliding speed is constant (the rotation is constant), it is discharged after a certain period of time. It keeps the paste circulating and is placed inside the main body of the one-turn viscometer so that the time during which the paste undergoes shearing is always constant, giving it the property of constant shear time, and it is a fluid such as paste that is shear time dependent. The objective was to enable continuous and accurate viscosity measurement.

The most useful specifications of a rotational viscometer for measuring the viscosity of fluids such as pastes are (1) that the viscosity measurement is not affected by the flow of the paste due to movement and kneading; (2)
In order to observe the thixotropy and flow curve of the paste, the rotation speed of the rotating body can be varied widely, for example, from 1 [rpm to lOO[rpm], and (3) the entire rotating body must not be submerged in the paste. (4) It is possible to measure the viscosity of even a small amount of paste, (5) It is robust, (6)
) It must be small, lightweight, and portable, and (7) It must be inexpensive.

(8) Even when the paste is mixed, the shear time and shear rate of the paste can be kept constant and measured, and as a result, the viscosity of the paste can be determined. The goal is to satisfy conflicting specifications.

The rotational viscometer of the present invention is a useful device that satisfies the above specifications (1) to (8), and solves the problems of conventional rotational viscometers that were unable to satisfy most of the above specifications. .

Means for Achieving the Problems of the Present Invention The problems of the present invention include: a stationary side member that is rotatably supported by being engaged with an elastic body such as a spring; a rotating body, a means for rotating the rotating body, a fluid inlet for flowing a fluid such as paste, which communicates with the minute gap, and the rotating body rotates opposite to the stationary side member. By doing so, a fluid outlet for discharging to the outside the fluid that has flowed into the micro-gap through the fluid inlet, and at least one of the stationary side member and the rotating body that face each other through the micro-gap. a fluid guide groove such as a spiral groove for actively flowing the fluid into the minute void through the fluid inlet formed on the surface of the fluid inlet and actively guiding the fluid to the fluid outlet; As the rotating body rotates, the viscosity of the fluid flowing into the micro-gap portion causes the rotational torque given to the stationary side member, which rotates against the elasticity of the elastic body, to be applied to the stationary side member or the elastic body. This is achieved by providing a rotational viscometer that is provided with a viscosity value display pointer provided in conjunction with at least one of them, and a viscosity value display section that allows the viscosity value of the fluid to be known by the movement of the pointer. can.

[Summary of the Invention] The outline of the rotational viscometer 1 of the present invention will be explained with reference to FIG. is fixed,
The upper end of the rotating shaft 5 is fixed to the lower end of the spring 4. The rotating shaft 5 is rotatably supported by a ball bearing 7.8 provided in a cylindrical bearing house 6 fixed to the stationary side 3. In the bearing house 6 above.

A long hole 9 with an appropriate opening angle width is formed, and a pointer 10 for displaying the viscosity value of the fluid passed through the long hole 9 is fixed horizontally to the connecting portion between the spring 4 and the rotating shaft 5. and rotates in conjunction with the spring 4 and rotating shaft 5.

An inner stationary cylindrical body 13 is fixed to the lower end of the rotating shaft 5, which has a spiral groove 11 formed therein for actively sucking a fluid such as a paste (not shown) through a fluid inlet 12 (described later) and sliding it up. are doing.

Note that the present invention is not limited to the spiral groove 11, and any suitable fluid guide groove such as a herringbone groove may be used, but particularly effective results have been obtained when a spiral groove is employed.

The upper part of the outer rotating cylinder 15, which is rotatably provided in the rotational viscometer main body 2 by a means not shown through the inner stationary cylinder 13 and the radial micro-gap 14, is formed to extend in the radial outward direction. A flange portion 15a is provided, and the flange portion 15a is
A toothed portion 15b is formed on the outer periphery of a.

The lower end of the outer rotating cylindrical body 15 is an open end, and the lower end of the cylindrical body 15 and the open upper end of the inner stationary cylindrical body 13 form a fluid inlet 12.

The fluid is supplied to the outer rotary cylindrical body 15 in the upper part 9 above the fluid inlet 12, for example, in the upper part than the spiral 11 of the static side columnar body 13, through the fluid inlet 12. A fluid discharge port 16 is formed for discharging the fluid that has been sucked into the rotational viscometer 14 and the fluid whose viscosity value has been measured by being drawn up is discharged to the outside of the rotational viscometer 1 .

Furthermore, within the rotational viscometer main body 2, a geared moniker 17 is fixed on a fixed side 18, and a toothed side portion 2 formed on the outer periphery of a gear 20 fixed to a rotating shaft 19 of this geared motor 17.
0a and the tooth side portion 15b formed on the outer rotating cylindrical body 15.
and are aligned.

Yet again. A viscosity value display scale plate 22 is fixed to a fixed side 21 that faces the above-mentioned viscosity value display pointer 10 via a gap. A see-through plate 23 made of transparent glass or plastic is formed on the rotational viscometer main body 2 so that the scale plate 22 and the viscosity value display pointer 10 can be seen through.

Therefore, the outer rotating cylinder 15 is connected to the geared motor 17.
When rotated by , the fluid, which is a viscous sample such as a highly viscous paste, enters the micro-cavity 14 from the fluid inlet 12 through the fluid inlet 12 formed at the lower end of the two-rotation axis meter 1. In order to generate rotational torque in the stationary side cylindrical body 13 due to the viscous resistance of the fluid, the cylindrical body 13 connected to the stationary side 3 by a spring 4 increases the elasticity of the spring 4 to a position where it balances with the viscous rotational force of the fluid. rotate against. As a result, the viscosity value display pointer 10 also rotates, so the position of the pointer 10 can be seen on the scale plate 22 through the see-through section 23.
You can find out the viscosity value of the fluid by reading it.

The outline of the invention of other embodiments will be made clear by the embodiments shown below, so the description thereof will be omitted.

[Example] A specific embodiment of the present invention will be described below.

FIG. 2 is a longitudinal cross-sectional view of a rotational viscometer 24 showing a first embodiment of the present invention. Close with
The lower opening end is closed with a lower cover plate 27 having a through hole. A cylindrical bearing housing 28 is fixed to the lower cover plate 27. Ball bearings 29 and 30 are provided at both upper and lower opening ends of the bearing housing 28, and rotatably support a hollow rotating shaft 31.

The lower end of the rotating shaft 31 is provided to protrude from a through hole formed in the lower cover plate 27, and the rotating cylindrical body 32 is fixed to the outer periphery of the protruding lower end of the rotating shaft 31 and integrated with the rotating shaft 31. and rotate it.

A fixed plate 33 is fixed on the bearing housing 28, and a geared motor 34 is fixed to this fixed plate 33.

A gear 36 is fixed to the rotating shaft 35 of the geared motor 34 and meshed with a gear 37 fixed to the one-rotation shaft 31.

A shaft 38 is inserted into the hollow part of the rotating shaft 31. The lower end of the shaft 38 is rotatably supported by a ball bearing 39 provided on the inner circumference of the upper part of the one-rotation cylindrical body 32.

A stationary cylindrical body 40 is fixed to the lower end of the shaft 38, and a cylindrical fluid circulation gap 41 with a minute gap is formed in the radial direction between the cylindrical body 40 and the rotating cylindrical body 32.

A lid 42 is fixed to the lower end opening of the rotating cylindrical body 32 for closing this opening. A fluid inlet 43 is formed at the lower end of the rotating cylindrical body 32 to allow fluid such as paste to flow into the gap 41 .

Instead of providing this fluid inlet 43, the lid 42 may be omitted and the fluid flowing into the gap 41 may be directly sucked up.

A fluid outlet 4.1 is formed in the upper part of the rotating cylindrical body 32 for discharging the fluid that has flowed into the gap 41 through the fluid inlet 43 to the outside of the rotating cylindrical body 32.

In this embodiment, the first cylindrical body 40 is on the fixed side, and the rotating cylindrical body 32 surrounding the cylindrical body 40 rotates, so that the force due to the flow of the external fluid is applied to the cylindrical body 40. This has the effect of being protected by the outer rotating cylindrical body 32 from being affected by this.

However, if no external force acts on the rotating body.

The outer cylindrical body may be a fixed side, and the inner cylindrical body may be a rotating body.

Incidentally, the cylindrical body 32 does not necessarily have to be a cylinder, and in short, the rotating cylindrical body 32 rotates the fluid in the fluid circulation gap 41 formed between it and the cylindrical body 40, thereby increasing the height of the fluid. Fluid such as viscous paste is removed from the fluid outlet 43.
Any shape is acceptable as long as it can be discharged from the container.

Similarly, the cylindrical body 40 is not necessarily limited to a cylinder or a cylindrical shape.

The fluid circulation gap 41 is not just a radial gap, but a radial gap with a length that allows the fluid such as paste to rise through the gap 41 by one rotation of the cylindrical body 32. It is necessary to make the gap void.

In this way, by utilizing the high viscosity of fluids such as paste,
The characteristic of the rotational viscometer 24 of the present invention is that it utilizes the property that the fluid moves up through the void 41, and furthermore, after measurement,
A major feature of the rotational viscometer 24 is that the fluid that has ascended through the gap 41 is discharged so that it returns to its original position.

In this way, in order to allow the fluid to rise efficiently even in the gap 41 with a minute gap (length), the surface of the cylindrical body 32 facing the gap 41 is positively axially moved. Spiral groove 4 that facilitates upward movement of fluid
5 is formed.

Note that the depth of this spiral groove 45 is formed to be minute.

Further, if the spiral groove 45 is not formed on the inner surface of the nine-rotation cylinder 32 facing the gap 41, a spiral groove 46 shown by a dotted line may be formed on the outer periphery of the first cylinder 40, or one spiral groove 45. 46 may be formed.

The spiral direction of these spiral grooves 45 and 46 is a direction in which the upward movement of the fluid is promoted by the rotation of the cylindrical body 32 for one rotation. Here, the leading angle of the spiral is set to be sufficiently small, usually 10 degrees or less, preferably 5 degrees or less, 1, for example, 3 degrees.

Note that the spiral grooves 45 and 46 are fluid guide grooves for actively lifting the fluid up into the gap 41, but an appropriate fluid guide groove such as a herringbone groove, which is limited to spiral grooves, may be adopted. Good too.

The fixing plate 33 also has a shaft 8 formed protruding from the upper part of the two cylindrical bearing housing 33.

Viscosity value display pointer 47 constituting the fluid viscosity value display section
is fixed so as to be able to rotate in the horizontal direction together with the shaft 38, facing a see-through part 48 formed of a material such as transparent glass or plastic provided on the side surface of the main body 25.

A viscosity value display scale plate 50 fixed to the fixed side 49 is fixed to the back of the pointer 47.

The upper part of the shaft 38 is fixed to the lower end of the spring spring 52 by a connecting member 51.

The spring spring 52 has its upper end fixed to the upper cover plate 26 by a connecting member 53. That is, the shaft 38 is rotatably supported by a spring 52 fixed to the fixed side.

Note that any suitable means may be used to connect the spring spring 52 and the shaft 38 and to fix the spring spring 52 to the upper cover plate 26.

FIG. 3 shows a rotational viscometer 54 showing a second embodiment of the present invention, in which the upper opening end of a rotational viscometer main body 55 constituting the fixed side is connected to a lower cover plate 56, and the lower opening end is connected to a lower cover plate 56. It is closed by a plate 57. A bearing housing 58 is fixed to the lower cover plate 57, and a stationary side cylindrical body 60 is rotatably supported by a ball bearing 59 provided in the bearing housing 58. The lower end of the stationary cylindrical body 60 is closed by the same member.

A fluid outlet 61 is formed at the upper end of the stationary cylinder 60, and a fluid inlet 62 is formed at the lower end. Two cylindrical bearing houses 63 are fixed to the upper end of the stationary cylindrical body 60.

A rotary shaft 66 is rotatably supported by pole bearings 64 and 65 at both upper and lower opening ends of the bearing house 63.

A one-turn cylindrical body 67 is fixed to the lower end of the rotating shaft 66. A fluid inflow gap 68 is formed between the rotating cylindrical body 67 and the stationary cylindrical body 60.

A fluid such as a paste having the properties of a high-viscosity non-Newtonian fluid that has flowed into the fluid inflow gap 68 through the fluid inlet 62 is rotated by the rotation of the rotating cylindrical body 67. In order to make it easier to ascend the gap 68, a spiral groove 69 is formed along the axial direction on the outer periphery of the rotating cylindrical body 67. This spiral groove 69
requires that the leading angle of the spiral be sufficiently small.

Note that instead of this spiral groove 69, a stationary side cylindrical body 60 is used.
A spiral groove 70 that facilitates the upward movement of the fluid may be formed along the axial direction as shown by the dotted line on the inner periphery of the groove, or both spiral grooves 69 and 70 may be provided.
Note that the guide groove is not limited to the spiral groove as described in the first embodiment, but may be a guide groove such as a herringbone groove having the same function.

A fixing plate 71 is fixed on the lower cover plate 57.

A fixing member 72 is fixed to this fixing plate 71, and a guard motor 73 is fixed to this fixing member 72. On the rotating shaft 74 of the guard motor 73.

A gear 75 is fixed, and this gear 75 meshes with a gear 76 fixed to the rotating shaft 66.

The upper part of the bearing housing 58 is connected to the lower end of a spring spring 77 using an appropriate connecting member such as a coupling, and the upper end of the spring 77 is connected to the upper part of the stationary side cylindrical body 60 using an engaging member 79. It is fixed to the cover plate 56.

In the bearing house 63, a viscosity value display pointer 80 constituting a viscosity value display section for the fluid faces a see-through section 81 formed of a material such as transparent glass or plastic provided on the side surface of the main body 55. The bearing house 63
It is fixed so that it can rotate horizontally.

A viscosity value display scale plate 83 fixed to the fixed side 82 is fixed to the back of the pointer 80.

The rotational viscometer 54 of the second embodiment of the present invention has the above configuration.

As described above, 1 rotational viscometer 24 as an embodiment of the present invention
．． 54 is configured as described above.

Therefore, 1. To measure the viscosity of a fluid such as a paste using the rotational viscometer 24, 54 of the present invention, 9. the tip of the rotating cylinder 40 in the rotational viscometer 24 or the stationary cylinder 60 in the rotational viscometer 54; When the fluid inlet 43.62 of the gear 36.75 is inserted and the geared motor 34.73 is rotated, the gear 36.75 rotates, and the gear 37.76 that meshes with the gear 36.75 also rotates, so that the gear 37.75 rotates. The rotating shaft 31.66 to which 76 is fixed also rotates in the same direction.

When the rotating shaft 31.66 rotates, the rotating cylindrical bodies 327 and 67, which are each fixed to this rotating shaft, rotate,
A fluid such as a paste having the properties of a high viscosity non-Newtonian fluid is sucked up from the fluid inlet 43.62 and enters the paste inflow gap 41.68, and the spiral groove 4
5 (or/and 46) and 69 (or/and 70) to slide up the gap 41.68.

In this way, as the fluid rises through the gap 41.68, the cylindrical body 40.68 rotates once. When the fluid is at a constant speed, it is discharged from the fluid discharge port 44.61 provided above the stationary cylinder 60 in a constant sliding time, and the cylinder 40.6 rotates once.
It travels along the outer periphery of the stationary cylinder 60 to reach the lower part and returns to the original position, that is, the position where the fluid is located at the time of this viscosity measurement.

When the fluid slides up the gap 41.68, the stationary cylindrical body 40. Since the rotational torque in the rotational direction of the cylinder 321 and the rotating cylinder 67 is applied to the stationary cylinder 60, the stationary cylinder 110 connected to the spring 52.77 and the stationary cylinder 60 are connected to the spring 52.
It rotates against the elasticity of 77 until it reaches a balanced position.

Stationary side cylindrical body 40. When the stationary cylindrical body 60 rotates, the viscosity value display pointer 47.80 fixed to the shirt l-38 and the bearing house 63 also rotates, so the position of this pointer 47.80 is determined by the scale of the scale plate 50.83. By checking and reading 9, it is possible to know the viscosity value of the measured fluid such as paste.

Now, a method for measuring the viscosity of a fluid using the rotational viscometer 24 shown in FIG. 2 will be explained.

As shown in FIG. 4, the radius of the stationary cylindrical body 40 is R2,
The radius of the inner circumference of the rotating cylindrical body 32 is R1, and the stationary side cylindrical body 40
The rotation speed of the cylindrical body 32 per revolution is N [rpm]
, D[5ec
-'3. The rotational torque received by the fluid of the static and non-stationary column body 40 is M.

If the viscosity of the fluid is η, a linear equation holds true.

D=(4πN R+2) / (R12R22)・60
...(1) η= (7,5M(R12-R22)) / R+2
・R22・π2hN・ ・ ・ (2) However, in the above formulas (1) and (2), the advance angle of the spiral of the spiral groove 45 is sufficiently small, and the depth of the gap 41 and the spiral groove 45 is also equal to that of the stationary side cylindrical body 32. This is based on the assumption that the diameter is sufficiently small compared to the diameter of

'Therefore, the radius R2 of the stationary cylindrical body 32 is shown as an equivalent value taking into account the surface area ratio of the peaks and valleys of the spiral groove 45.

Further, as another analysis method, a method for determining the composite shear rate of a spiral groove will be explained with reference to FIG.

Referring to FIG.
l+radius of stationary side cylindrical body 32° (radius to peak 45a of spiral groove 45) as r2. In the case where the radius of the valley portion 45b of the spiral groove 45 formed in the stationary side cylindrical body 32' is r3.

Ml: Amount of rotational torque between the trough 4.5 b between the rotating cylindrical body 40' and the stationary cylindrical body 32° 2: The peak 4 between the rotating cylindrical body 40' and the stationary cylindrical body 32'
Rotating torque Dl between 5a: Sliding speed D2 between the rotating cylindrical body 40'' and the trough 45b of the stationary cylindrical body 32': Sliding speed between the rotating cylindrical body 40' and the peak 45a of the stationary cylindrical body 32' Then, the resultant rotational torque M and the resultant shear rate can be obtained by a linear equation.

Composite rotational torque M = M1 + M2 (3) Composite sliding speed D = DI・(A, C)+D2・(^2/A)
(4) However, A1: trough 45 at 32° of the stationary side cylindrical body
Total surface area A2 of a: Peak portion 45 of stationary side cylindrical body 32'' Total surface area A of b: Combined surface area of trough 45a and peak 45b of stationary side cylindrical body 32' A=A+ +A2 (5) Above equation (4) )
can be found using the following method.

The viscous force F applied to the 32° cylindrical body at rest is expressed by the following equation from equation (3).

F:1IDIAI+η2D2A2 =ηDA (6) However, η, η! , η2 : Viscosity of the fluid Here, even if the fluid is a non-Newtonian fluid, different sliding speeds, ,D
If the difference between 2 and 2 is sufficiently small, it can be assumed that the viscosity ηl''=η2.

Therefore, by eliminating the viscosity η from the above equation (6), (
4) Equation can be obtained.

The methods shown in equations 3) to (6) above are simple calculation method examples as 2-examples, and it goes without saying that other suitable calculation method examples may be used.

For example, it can be calculated using a fluid dynamic analysis method of a screw pump, or an average shear rate and a fluid curve approximation formula.

Furthermore, a method for actually measuring the viscosity of a high viscosity fluid such as a paste with high accuracy will be described below.

Since fluids such as paste (ink) have the properties of high viscosity non-Newtonian fluids, the viscosity value at that time (shear rate) D of the rotating cylinder at 32° is as follows. Viscosity.

Here, as fluids, especially pastes, there are mainly pseudoplastic fluids and plastic fluids, and these pastes have rotational torque (shear stress) M on the Y axis and rotational speed (shear rate) on the X axis.
If D is taken, the flow curves 8 shown in Figures 6 and 7, respectively.
Draw 4.85.

Note that straight lines 86, 87, and 88 shown by dotted lines are rotational torque curves in the case of Newtonian fluid.

These straight lines 86, 87, and 88 increase in proportion to the number of revolutions and the rotational torque. The straight lines 86, 87°88 extend linearly at θ, θl, and θ2 degrees, respectively, whereas for a high viscosity fluid such as paste, the flow curve 84.8
As shown by 5, it is a fluid curve. This curve 8
As is clear from 3.84, the yield value f differs depending on the type of high viscosity fluid such as paste.

That is, the viscosity η is.

Viscosity η; (shear stress M)/(shear rate D) = M/
It is expressed as D=tanθ (7).

To be more precise, the sliding speed equation shown in equation (1) can be expressed as follows. Referring to FIG. The radius of is R1, and the cylindrical surface shear rate of the stationary cylindrical body 40 is D22.
Let the speed of each inner surface of the rotating cylindrical body 32 be Dl.

D1= ((2R22)/(R12R22))・(2
πN/60) (8)1)2-((2R+2>
/' (R12R22) )・(2πN/60)
(9) What is the average shear rate?

D-(DI+D2)/2 = ((R12+R22)/(R,2-R,,2)
)・(2πN/60) (10).

Based on this concept of average shear rate, if the formula (4) is calculated by calculating the 1 composite shear rate using the formula (4), a highly accurate average shear rate can be obtained.

If the material stretches in a straight line, the viscosity η with respect to the sliding speed is always constant.

However, as shown in FIGS. 6 and 7, in a non-Newtonian fluid paste, the viscosity η depends on the sliding speed, and the angles θ, θ1. θ2 is different, so just finding one point on the flow curve does not have much meaning.

Therefore, in order to determine the viscosity η of a high viscosity fluid such as a paste, measure the viscosity η at at least two points (for example, θ1 and θ2), calculate the ratio, and calculate the thixotropic index, which does not indicate the degree of thixotropy. , its flow curve 84 (
The same condition is adopted for curve 85.

It is useful to employ at least one of the following methods as a method for measuring this measurement content.

It is desirable to adopt all of them if possible.

Method: (a) Measure the viscosity at a constant rotational speed (shear rate) D. ...Thus, the viscosity value of a high viscosity fluid such as paste at a predetermined rotation speed can be determined in advance.

(b) Viscosity at low rotation speed DL is ηL, high rotation speed D
Find the thixotropic index when the viscosity of u is ηU.

The thixotropic index can be expressed by a linear equation.

Thixo index = ηL/ηu (tt) In the above example, a radial gap type rotational viscometer was explained as a nine rotational viscometer, but the invention is not limited to this, and an axial gap type or other structure may be used. 1. It goes without saying that the structure may be modified as appropriate without departing from the spirit of the present invention.

Further, in the above embodiment, the rotating body is supported using a spring, but the rotating body is not limited to the spring, but may be constructed using other suitable elastic bodies.

Although the rotational viscometer has the configuration shown above in order to be constructed at low cost, it requires necessary electrical circuits such as means for changing the rotational speed of the motor, means for changing the rotational speed of the motor, and temperature correction means. It goes without saying that you can add
It goes without saying that the rotational viscometer may be provided with various groups of changeover switches and the like, taking design specifications, cost, etc. into consideration as appropriate.

In the above embodiment, a spring is interposed between the means for rotating the rotating body and the stationary side member, and the viscosity value display pointer is linked to the stationary side member.
The viscosity value display pointer needle may be linked to the pi. Also, in practice, although it is not very desirable in terms of design, a spring is interposed between the means for rotating the rotating body and the rotating body, and the viscosity value display pointer is rotated in conjunction with the rotating body or the spring. It's okay. however.

In this case, the stationary side member must be kept in a fixed state, and when reading the viscosity value, it is convenient to fix the viscosity value display pointer with an appropriate means such as an electromagnet.

[Effect of the invention] The rotational viscometer of the present invention has the following effects.

1) For example, let's take a screen printing machine as an example.

Conventionally, screen printing machines rely on the experience of printing engineers and laboratory measurements to control the viscosity of the paste, and since the paste has non-Newtonian fluid properties, it is difficult to know the exact viscosity value. This made it impossible to accurately control the viscosity, making it impossible to perform highly accurate screen printing.

This is because the paste has the properties of a non-Newtonian fluid as described above, and is also thixotropic, and because the amount of paste on the printing press is small, it was not possible to know the exact viscosity of the paste. .

However, according to the rotational viscometer of the present invention, even if the amount of paste on the screen printing machine is small, or even if the paste has non-Newtonian fluid properties and thixotropic properties, the shear time and shear rate are constant. Since conditions can be set, the viscosity of the paste can be measured with high accuracy, and the viscosity of the paste can be measured immediately before printing, allowing highly accurate screen printing.

(2) The rotational viscometer of the present invention can be configured to be small and lightweight, and is therefore portable.

It is easy to carry anywhere you need it, and you can easily measure the viscosity of a fluid anywhere.

(3) The rotational viscometer of the present invention can measure the viscosity of a fluid by simply inserting its tip into the fluid to be measured. It is possible to measure the viscosity of a small amount of paste, etc.
This makes it possible to measure the viscosity of fluids in small areas, which is difficult to do with conventional rotational viscometers.

(4) Since it is possible to measure the viscosity of small amounts of fluids such as pastes, it is possible to measure the viscosity of many AV1 constant fluids such as pastes arranged in various shapes compared to conventional rotational viscometers. is possible.

(5) Since it is possible to measure the viscosity of a small amount of fluid such as paste, viscosity measurement is not affected by the flow of the fluid to be measured such as paste during movement and kneading.

(6) Rotating body 1, for example, 1 [rpm] to 100 [r
pm] and has a structure that allows for a wide variable range,
The thixotropy and flow curve of a fluid to be measured, such as a paste, can be easily investigated, allowing highly accurate viscosity control.

(7) According to the rotational viscometer of the present invention, the time and speed at which a continuously kneaded fluid such as a paste to be measured is discharged from the core inserted into the rotational viscometer can be calculated. Because it can be kept constant, that is.

Since the shear time and shear speed can be kept constant, the viscosity value can be accurately measured and managed.

In particular, for non-Newtonian fluids such as pastes, the viscosity generally changes depending on the rubbing time and speed, and the viscosity also changes due to the rubbing of a one-turn viscometer, so it is necessary to specify the measurement time and determine the measured value. In the rotational viscometer of the present invention,
1. For kneading a fluid such as a paste, etc. 1. For example, by rotating a cylinder, etc., the fluid such as a paste is suctioned by itself, and under a constant shear rate (constant rotation), it is discharged after a certain period of time to form a paste, etc. (However, this circulation is different from the conventional forced circulation method, which has drawbacks.) In order to keep circulating the fluid (this circulation is different from the conventional forced circulation method, which has drawbacks), the time required for the fluid such as paste to be rubbed inside the axis meter body per rotation is The viscosity can be kept constant and the viscosity can be measured continuously and accurately even for fluids such as pastes that are dependent on the rubbing time.

(8) Other 1 The rotational viscometer of the present invention has the characteristics of being compact, inexpensive, and robust.

[Brief explanation of drawings]

FIG. 1 is a detailed explanatory diagram of the present invention, and FIG. 2 is a first diagram of the present invention.
FIG. 1 is a vertical cross-sectional view of a rotational viscometer as an example. Fig. 3 is a longitudinal cross-sectional view of a rotational viscometer as a second embodiment of the present invention, Figs. 4 and 5 are explanatory diagrams for determining the viscosity of a fluid such as paste, and Fig. 6 is a pseudoplastic Flow curve of fluid. FIG. 7 shows the flow curve of plastic fluid. [Explanation of symbols] 1...Rotational viscometer, 2...1 Rotary axis meter body, 3...
...Fixed side, 4...Spring, 5...Rotating shaft, 6...
Bearing house, 7.8...Ball bearing, 9
...Long hole, 10...Viscosity value display pointer, 11...
spiral groove. 12...Fluid inflow 0.13...Inner stationary cylindrical body,
14... Microgap portion, 15... Outer rotating cylindrical body, 1
5a... Flange part, 15b... Teeth side part, 16... Fluid discharge port, 17... Geared motor, 18... Fixed side, 19... Rotating shaft, 20... Gear, 20a...
Tooth side. 21... fixed side, 22... viscosity value display scale plate,
23... Transparent part, 24... Rotational viscometer, 25...
Rotational viscometer body, 26... Upper cover plate, 27... Lower cover plate, 28... Bearing housing, 29.30... Ball bearing. 31... Rotating shaft, 32... Rotating cylindrical body. 32"...Rotating cylindrical body, 33...Fixing plate. 34...Geared motor, 35...Rotating shaft. 36.37...Gear, 38...Shaft. 39...Ball bearing, 40... Stationary side cylindrical body, 40°... Stationary side cylindrical body. 41... Fluid circulation gap, 42... Lid. 43... Fluid inflow 0.44... Fluid Outlet, 4
5.46... Spiral groove, 47... Viscosity value display pointer, 48... Transparent part. 4... fixed side, 50... scale plate for viscosity value display, 5
1... Connection member, 52... Spring spring, 53...
... Connecting member, 54... Rotational viscometer, 56... Upper cover plate, 57... Lower cover plate. 58... Bearing housing, 59... Ball bearing, 60... Stationary side cylindrical body, 61... Fluid outlet, 62... Fluid inlet. 63...bearing house, 64.65...ball bearing, 66...rotating shaft. 67... Rotating cylindrical body, 68... Fluid inflow gap,
69.70...Spiral groove. 71...Fixing plate, 72...Fixing member. 73... Guard motor, 74... Rotating shaft. 75.76...Gear, 77...Spring spring, 7
8.79... Connecting member, 80... Pointer for viscosity value display, 81... Transparent part, 82... Fixed side, 83... Scale plate for viscosity value display. 84.85...Flow curve. 86,...,88...Rotational torque 2 rotation curve.

Claims (7)

[Claims] (1) a stationary side member, a rotating body provided to the stationary side member via a microgap, and means for rotating the rotating body;
A fluid inlet for flowing a fluid such as paste into the micro-gap, and a micro-gap formed by the rotating body rotating opposite to the stationary side member through the fluid inflow port. A fluid outlet for discharging the fluid that has flowed into the section to the outside, and a fluid inlet that is formed on at least one surface of the stationary side member and the rotating body, which face each other through the minute gap, A fluid guide groove such as a spiral groove for allowing the fluid to flow into the minute gap and actively guiding the fluid to the fluid outlet; The rotation is caused by an elastic body such as a spring engaged between the means for rotating the body and the viscosity of the fluid that flows into the minute gap when the rotating body rotates against the elasticity of the elastic body. The rotating torque applied to the body or the stationary member is controlled by a viscosity value display pointer provided in conjunction with at least one of the rotating body or the stationary member or the elastic body, and the movement of the pointer causes the rotational torque to be applied to the fluid. A rotational viscometer equipped with a viscosity value display section that allows you to know the viscosity value. (2) When the elastic body is engaged with the stationary side member, the stationary side member is rotatably supported, and the viscosity value display pointer is attached to either the elastic body or the stationary side member. Claim No. (1) provided in conjunction with
Rotational viscometer as described in section. (3) The stationary side member is a stationary side columnar body, and the rotating body is rotatably supported on the outside of the stationary side columnar body, facing the stationary side columnar body through a cylindrical minute gap. The rotational viscometer according to claim (2), which is a cylindrical body. (4) The stationary side member is a stationary side cylindrical body, and the rotating body is a rotating columnar body rotatably supported inside the stationary side cylindrical body via a cylindrical minute gap. , a rotational viscometer according to claim (2). (5) The rotational viscometer according to claim (1), wherein the fluid guide groove is a spiral groove formed along the axial direction. (6) Claims (1) to (5), wherein the fluid inlet is formed at the lower end of the rotating cylindrical body.
The rotational viscometer according to any one of paragraphs. (7) The rotational viscometer according to claim 6, wherein the fluid outlet is provided at a position above the fluid inlet of the rotating cylindrical body.