JP3484271B2 - Method for positioning conical rotor of conical-plate type viscometer and jig for positioning conical rotor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of positioning a conical rotor of a cone-plate type rotary viscometer with respect to a flat plate, and a jig used for carrying out the method.

[0002]

2. Description of the Related Art In a conventional cone-plate type rotary viscometer, as shown in FIG. 5, a cone rotor 2 is installed so as to face a plate 1 holding a liquid substance.
It is connected to the torsion wire 4 via the rotor shaft 3. When there is relative rotation of the flat plate 1 or the conical rotor 2 (the flat plate 1 is rotating in the viscometer in the figure), viscous torque acts on the conical rotor, and the torsion wire is twisted in proportion to this torque. Reference numeral 6 denotes a declination reading sensor that reads the amount of twist (declination) of the rotor shaft 3. An output signal of the declination reading sensor 6 is sent to the control unit 7, and the output signal of the control unit 7 is transmitted to the rotor shaft. It is fed back to the torquer 5 provided in the middle of 3. Based on the signal from the eccentricity reading sensor 6, the torquer 5 emits a reverse torque that opposes the viscous torque, restores the twist of the torsion wire 4, and finally the reverse torque automatically balances with the viscous torque.
Feedback control is configured so that the deflection angle becomes zero.

By the way, in such a cone-plate type rotational viscometer, as a general rule, it is arranged so that the apex of the cone is in contact with the plate surface as shown in FIG. In this regular arrangement, the viscous torque T and the shear velocity D are expressed by the following equations (1) and (2).

[0004]

[Equation 1]

[0005]

[Equation 2]

Here, η is the viscosity of the liquid to be measured, ω is the rotation speed, R is the radius of the conical rotor, and φ is the inclination angle of the conical rotor. Equation (2) means that the shear velocity is uniform everywhere in the conical rotor, which is a major feature of the cone-plate type rotary viscometer. The actual conical tip is slightly truncated at the top of the conical rotor, as shown in FIG. 7, to avoid friction in the measurement. Also in this case, the normal arrangement is that the virtual apex of the cone is in contact with the flat plate surface. If it is not a regular arrangement and the apex is separated from the flat plate by ε as shown in FIG. 8, the viscous torque and the shear rate are expressed by the following equations (3) and (4).

[0007]

[Equation 3]

[0008]

[Equation 4]

Here, r is the distance measured from the apex of the conical rotor in the radial direction. Since there is a term of r in the equation (4), the shear rate changes depending on the position displaced from the apex of the conical rotor in the radial direction, and the characteristic of “uniform shear rate” of the cone-plate type rotary viscometer is , Indicates that it will collapse.
The following Table 1 is a value obtained by the equation (3) for the degree of influence ΔT / T (%) of ε on the viscous torque by taking three conical rotors as an example. Effect on viscous torque ΔT / T (%) = 3
ε / 2Rφ, and as an example, in order to set ε with the degree of influence on the viscous torque at 0.5%, that is, in order to position the conical rotor, it is necessary to perform in units of 10 ⁻⁶ m. I understand.

[0010]

[Table 1]

Taking the same conical rotor as an example, the influence degree ΔT / T (%) of the machining tolerance ΔR of R on the viscous torque is (1)
From the formula, the degree of influence on viscous torque ΔT / T (%)
= 3ΔR / R, as shown in Table 2 below. Although the radius R of the conical rotor is affected by the cube of the third power, it can be understood that the outer diameter machining can be performed with high precision, and thus the influence on the viscous torque is small.

[0012]

[Table 2]

Taking the same conical rotor as an example, the influence degree ΔT / T (%) of the machining tolerance δ of the cone angle φ on the viscous torque is calculated from the equation (1).
(%) = Δ / φ, which is shown in Table 3 below. As can be seen from the table, the effect of the machining error of the cone angle φ is quite large.

[0014]

[Table 3]

One of the conventionally proposed methods for positioning the conical rotor is to use a distance sensor such as a dial gauge or a laser displacement gauge to provide a reference surface for positioning the conical rotor (see FIG. 9). 2a) is a method of setting the distance between the flat plate and the conical rotor so that the flat plate 1 is located at a predetermined distance Ha from the flat plate 1. Another way is
As described in Japanese Utility Model Laid-Open No. 3-63846, the detection pin 2b serving as a positioning reference point is provided at the center of the top of the conical rotor.
Is provided, and after detecting the contact of the pin tip with the flat plate electrically, the detection pin 2b is positioned at a predetermined distance Hb from the flat plate 1 to set the distance between the flat plate and the conical rotor. Is.

In any of the above methods, the dimension from the positioning reference surface 2a of the conical rotor or the detection pin 2b, which is the positioning reference point, to the virtual apex of the cone is 10 ⁻⁶ as shown in Table 1. You have to know exactly in m units. However, a precise shape measurement of a conical rotor, which is a cone, in units of 10 ⁻⁶ m requires a special device such as a three-dimensional measuring device and requires a great deal of labor, which is not easy. is there.

Therefore, a method that has been put into practical use has been a method using a standard solution for calibrating a viscometer (JIS Z 8890) which does not require the shape measurement of a conical rotor. This method
Measure the standard solution with the cone-plate type rotary viscometer to be adjusted, and adjust the conical rotor so that the display / output of the viscometer matches the viscosity of the standard solution, that is, the viscous torque reaches a predetermined value. This is a method of adjusting the distance ε from the flat plate. For example, ε in the equation (3) is adjusted so that the viscous torque T becomes a predetermined value even if the cone angle φ has a processing error. As a result, the regular arrangement is not always obtained, and the uniformity of the shear rate is somewhat sacrificed, but the average effective shear rate becomes a difference that is not a problem in practical use. Also,
The viscous torque generated by each conical rotor has an instrumental error determined by the machining error of the cone angle φ as shown in Table 3. However, this also reduces the instrumental error by adjusting ε. The advantage is that any conical rotor produces a specified torque and can be treated as a compatible conical rotor.

[0018]

However, the method put to practical use has a problem in that it causes ambiguous and unclear positioning due to various error factors described below. That is, for example, if there is an error in the temperature control or temperature detection of the measurement liquid, including the amount of the viscosity error that occurs including the temperature error, as a result, the display / output of the viscometer matches the viscosity of the standard liquid. The conical rotor is arranged at the position of ε such that

Further, for example, when calibrating the torque-display / output conversion characteristic of the viscometer main body, if the reference torque given to the main body is accompanied by an error, the torque error is also included, and as a result, It means that the conical rotor is arranged at the position of ε such that the display / output of the viscometer matches the viscosity of the standard solution. In this way, the position where the conical rotor is arranged is set at a position where the conical rotor is absorbed in order to absorb the total error including the influence of various factors in addition to its geometrical shape. There was a problem that it was unclear and vague because it was not possible to clearly indicate whether or not it was a numerical value.

The present invention has been made in view of the above problems, and the positioning of the conical rotor can be determined only from the geometrical shape, and the effect of the machining error of the conical angle can be reduced. The purpose is to provide a method. Another object of the present invention is to provide a jig used for carrying out the above-mentioned conical rotor positioning method.

[0021]

In order to achieve the above object, in the invention described in claim 1, a flat plate holding a liquid substance and a circle processed into a conical angle φ'opposed to the flat plate. A method of positioning a conical-plate type rotary viscometer equipped with a conical rotor with respect to a conical rotor plate, wherein a design value of a radius of a bottom surface of the conical rotor is R, and a design value of a conical angle of the conical rotor is φ. 2 from the center of the conical rotor
The distance between the flat surface and the conical surface that is / 3R apart is 2/3
The feature is that the position of the conical rotor is determined so as to coincide with R · φ.

According to this method, as described below with reference to FIG. 1, the distance ε between the virtual vertex of the conical rotor and the flat plate is ε.
And the influence of the cone angle error on the torque can be reduced. Letting δ be the machining tolerance of the cone angle and φ ′ be the angle of the machined rotor,
There is a relationship of the following expression (5).

[0023]

[Equation 5]

As shown in FIG. 1, the distance between the flat plate and the portion on the conical surface that is ⅔R in the radial direction from the center of the conical rotor is 2
When the position of the conical rotor is determined so as to match / 3R · φ, the distance ε between the virtual top of the conical rotor and the flat plate is expressed by the following equation (6). However, tanφ = φ, tanφ ′ = φ ′
And

[Equation 6]

The viscous torque T'of the conical rotor positioned as shown in the figure is expressed by the following equation (3).

[Equation 7]

Considering the ratio between the viscous torques T and T'of the cone angle φ which are normally arranged, from the equation (7) / (1),

[Equation 8]

Since φ = φ '+ δ from the equation (5),
Equation (8) is

[Equation 9] Becomes If the difference of T ′ with respect to T is ΔT, and is set as in equation (10),

[Equation 10]

The equation (9) is expressed as follows.

[Equation 11]

Using the equation (12), the degree of influence of the angular error on the viscous torque of the conical rotor treated in Table 3 is similarly obtained as shown in the following table.

[Table 4]

As shown in Table 4, it can be seen that the degree of influence is almost zero and is significantly improved. Further, the distance ε between the apex of the conical rotor and the flat plate can be specified by the value of the expression (6). Further, in the invention according to claim 2, a flat plate holding the liquid substance and a cone angle facing the flat plate
A method of positioning a conical-plate type rotary viscometer with respect to a flat plate of a conical rotor having a conical rotor processed to φ ', wherein a reference plane or a reference point of the conical rotor is determined, and a radius of a bottom surface of the conical rotor is determined. Where the design value is R and the design value of the cone angle of the conical rotor is φ, the location on the conical surface that is ⅔R away from the center of the conical rotor in the radial direction and the predetermined reference surface or reference point. The distance d between the reference plane or the reference point and the flat plate is 2 / 3R · φ ± d
The conical rotor is positioned so as to coincide with (the sign is − when the reference plane or the reference point is located above the top of the conical rotor, and the sign is + when it is in the opposite direction).

Since the position of the conical rotor is determined so that the distance between the reference plane or the reference point and the flat plate coincides with 2 / 3Rφ ± d, it is easy to accurately set the distance between the flat plate and the reference plane or the reference point. With, the setting of the conical rotor can be performed more easily. The invention according to claim 3 is a jig used for carrying out the method for positioning a conical rotor of a conical-plate type rotational viscometer according to claim 2, wherein the jig is a reference surface or a reference point of the conical rotor. A support body that supports the conical rotor with a support surface that can be in close contact, a movable body that is movable coaxially with the conical rotor in the direction of the central axis of the conical rotor, and one surface that is orthogonal to the central axis of the movable body. A distance meter that measures the axial movement distance of the movable body with reference to the position in close contact with the support surface of the support body, the surface of the movable body being 2 / 3R in the radial direction from the central axis. Drilled to a distance, when the conical rotor is installed with its reference surface or reference point in close contact with the support surface of the support,
The edge of the hole of the movable body is moved so as to abut the conical surface of the conical rotor, and the moving distance of the movable body at that time is obtained by the distance meter, so that 2 / in the radial direction from the center of the conical rotor. A distance d between a point on the conical surface 3R away and a reference surface or a reference point of the conical rotor is determined.

According to a fourth aspect of the present invention, there is provided a jig used for carrying out the method for positioning the conical rotor of the conical-plate type rotational viscometer according to the second aspect, which is a support for supporting the conical rotor. A body, a movable body coaxial with the conical rotor and movable in the central axis direction of the conical rotor, and movable in the central axis direction of the conical rotor, and the movable body restricts access to the conical rotor. With a reference pin driving body,
And one surface orthogonal to the central axis of the movable body is bored to a position spaced apart by 2 / 3R in the radial direction from the central axis, and the edge of the bored hole of the movable body is provided with a conical rotor. In the state of being in contact with the conical surface, the driving body is brought close to the conical rotor until it is regulated by the movable body, and the reference pin is driven into the conical rotor. The distance d between the point on the conical surface distant from the center of the conical rotor by 2 / 3R in the radial direction and the reference point of the conical rotor is defined by the tip of the driving body and the surface of the movable body. It is determined as the interval when closest to.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In this embodiment mode, FIG.
As shown in FIG. 3, the conical rotor 2 is arranged so as to face the flat plate 1. When the design value of the radius of the bottom surface of the conical rotor 2 is R and the design value of the conical angle of the conical rotor 2 is φ, the conical rotor 2 having the conical angle φ ′ is
1 and the state when the conical rotor 2 is positioned so that the distance h ₀ between the flat plate 1 and the point 2c on the conical surface that is 2 / 3R away from the center in the radial direction coincides with 2 / 3R · φ. Figure 2
Shown in. FIG. 1 shows a conical rotor with an angular error of −δ (φ ′ = φ−δ), and FIG. 2 shows an angular error of + δ (φ ′ = φ ′ =
It is a conical rotor with φ + δ). Further, a conical rotor having a designed conical angle φ with no angular error is also shown by an imaginary line.

The distance ε between the apex of the conical rotor and the flat plate when the conical rotor 2 is positioned as shown in FIG. 1 or 2 can be specified by the value of the expression (6) as described above. In addition, the degree of influence of the angular error on the viscous torque can be made extremely small. In the above method, it is necessary to accurately grasp the position of the point 2c on the conical surface that is 2 / 3R away from the center of the conical rotor in the radial direction. Therefore, a reference surface or reference point that has been conventionally used as the reference position of the conical rotor 2 and is easy to accurately set the distance from the flat plate is used, and the conical surface 2 / 3R away from the center of the conical rotor 2 in the radial direction. The distance d between the upper point 2c and the reference plane or the reference point is previously determined, and the distance between the reference plane or the reference point and the flat plate is 2
Positioning of the conical rotor so that it matches / 3R · φ ± d (the sign is − when the reference plane or the reference point is above the top of the conical rotor, and the sign is + when it is in the opposite direction). You can also

FIG. 3 shows a jig used to determine the distance d between the point on the conical surface distant from the center of the conical rotor 2 by 2 / 3R in the radial direction and the reference surface or the reference point. In the example of FIG. 3, the bottom surface 2a of the conical rotor 2 is used as a reference surface, and the jig 10 includes a support body 12, a movable body 14, and a dial gauge 16 which is a distance meter.

The support 12 has a hole 12b having a radius R, and the bottom surface of the hole 12b is a support surface 12a which can be brought into close contact with the bottom surface 2a of the conical rotor 2 and supports the conical rotor 2. The movable body 14 is slidably arranged in the hole 12b of the support body 12. Therefore, the movable body 14 can move coaxially with the conical rotor 2 and in the direction of the central axis of the conical rotor 2. The surface 14a of the movable body 14 that faces the support surface 12a and is orthogonal to the central axis of the conical rotor 2 is drilled to a position that is 2 / 3R away from the central axis of the conical rotor 2 in the radial direction. A circular edge 14c is formed at a distance of 2 / 3R in the radial direction.

The surface 14a opposite to the surface 14a of the movable body 14
One end 16a of the micro gauge 16 is fixed to the. The contact 16b of the micro gauge 16 is the support 12
Is directed toward the upper end surface 12c in the figure. In the jig 10 thus configured, the conical rotor 2 is attached to the bottom surface 2a.
Is in close contact with the support surface 12a of the support 12
2 and the surface 14a of the movable body 14 is moved toward the conical surface of the conical rotor 2, the edge 14c of the surface 14a contacts the conical surface. The distance between the movable body 14 and the support 12 at this time is measured by the micro gauge 16. Since the distance between the surface 14a and the surface 14b of the movable body 14 and the distance between the support surface 12a and the upper end surface 12c of the support 12 are known, from the result measured by the micro gauge 16, from the center of the conical rotor 2. It is possible to obtain the distance d between the location on the conical surface that is 2 / 3R away in the radial direction and the bottom surface 2a of the conical rotor 2.

When the distance d is determined by the jig 10 in this way, the distance between the bottom surface 2a of the conical rotor 2 and the flat plate 1 is 2
The bottom surface 2a of the conical rotor 2 so that it becomes / 3R · φ + d.
The position of can be set using a distance sensor such as a dial gauge or a laser displacement meter. This jig 10 has the effect of significantly simplifying the shape measurement of the conical rotor 2.

FIG. 4 is a cross-sectional view showing another jig, in which the reference point of the conical rotor is determined, and the distance between the reference point and the point on the conical surface that is ⅔R in the radial direction from the center of the conical rotor. d
Used in the decision. The jig 20 shown in FIG.
And a movable body 24 and a reference pin driving body 26.

The support 22 has a cylindrical shape with a radius R,
One end surface thereof serves as a support surface 22a that supports the conical rotor 2. A movable body 24 having a hole 24b with a radius R is slidably arranged outside the support body 22. Therefore, the movable body 24 can move coaxially with the conical rotor 2 and in the direction of the central axis of the conical rotor 2. The bottom surface 24a of the hole 24b orthogonal to the central axis of the conical rotor 2 is drilled to a location that is 2 / 3R away from the central axis of the conical rotor 2 in the radial direction, and is 2 / 3R away from the central axis in the radial direction. A circular edge 24c is formed.

The reduced diameter hole 2 is communicated with the hole 24b of the movable body 24.
4d extends upward, and the reduced diameter portion 26a of the reference pin driving body 26 is slidably arranged in the reduced diameter hole 24d. An enlarged diameter portion 26b is provided above the reduced diameter portion 26a,
Since the expanded diameter portion 26b abuts and interferes with the movable body 24,
The reference pin driving body 26 is restricted from approaching the conical rotor 2 by the movable body 24.

In the jig 20 thus constructed,
The bottom surface 2a of the conical rotor 2 is the support surface 22 of the support 22.
When the surface 24a of the movable body 24 is moved toward the conical surface of the conical rotor 2 when installed on the support 22 in a state of being closely attached to a,
The edge 24c of the surface 24a abuts the conical surface. In this state, the expanded diameter portion 26b of the reference pin driving body 26 is moved to the movable body 2
4, the reference pin 2b driven into the top of the conical rotor 2 is pushed in until it comes close to and interferes with the conical rotor 2. At this time, the distance d between the tip of the reference pin driving body 26 and the surface 24a of the movable body 24 can be set in advance, and this distance d is on the conical surface 2 / 3R away from the center of the conical rotor 2 in the radial direction. Since the distance is equal to the distance between the reference pin 2b and the reference pin 2b, the reference pin 2b can be set to a predetermined height.

In this manner, the reference pin 2 is moved by the jig 20.
If b can be set, the position of the reference pin 2b of the conical rotor 2 is set to, for example, the actual flat plate 3-638 so that the distance between the reference pin 2b of the conical rotor 2 and the flat plate 1 becomes 2 / 3R.phi.-d.
It can be set by the method described in No. 46. This jig 20 makes it unnecessary to measure the shape of the conical rotor 2.

[0044]

As described above, according to the present invention as set forth in claim 1 or 2, since the positioning of the conical rotor can be determined only from the geometrical shape, the conventional viscosity standard solution is used. Unlike the method, the positioning accuracy is improved without being affected by other factors. Further, like the conventional method using the viscosity standard solution, it is possible to eliminate unclearness and ambiguity, and it is possible to express the distance between the top of the conical rotor and the flat plate from the machining tolerance of the cone angle. Further, since the viscosity standard solution is not used, troublesome work such as injection and cleaning of the solution is eliminated, and a thermostatic device or the like for temperature control is unnecessary.

Further, the influence of the processing error of the cone angle can be made very small. According to the third aspect of the invention, the shape measurement of the conical rotor is significantly simplified. According to the invention as set forth in claim 4, it is not necessary to measure the shape of the conical rotor, and the reference pin can be easily set.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of the present invention, and is an example in the case of a conical rotor having an angular error of −δ (φ ′ = φ−δ).

FIG. 2 is an explanatory view showing the method of the present invention, and is an example in the case of a conical rotor having an angular error of + δ (φ ′ = φ + δ).

FIG. 3 is a sectional view showing a jig of the present invention.

FIG. 4 is a sectional view showing a jig of the present invention.

FIG. 5 is an explanatory diagram showing the principle of a cone-plate type rotational viscometer.

FIG. 6 is a diagram illustrating a positional relationship between a conical rotor and a flat plate of a conventional cone-plate type rotary viscometer.

FIG. 7 is a diagram illustrating a positional relationship between a conical rotor and a flat plate of a conventional cone-flat plate rotational viscometer.

FIG. 8 is a diagram illustrating a positional relationship between a conical rotor and a flat plate of a conventional cone-plate type rotary viscometer.

FIG. 9 is a diagram illustrating a positional relationship between a conical rotor and a flat plate of a conventional cone-flat plate rotational viscometer.

[Explanation of symbols]

1 flat plate 2 conical rotor 2a bottom 2b Reference pin R Design value of the radius of the bottom of the conical rotor φ Design value of cone angle of conical rotor 10, 20 jig 12, 22 Support 12a support surface 14, 24 movable body 14a, 24a Surface of movable body 14c, 24c edge 16 rangefinder 26 Reference pin driven body

Claims (4)

(57) [Claims] 1. A method for positioning a conical rotor of a conical-plate type rotary viscometer with respect to a flat plate, the flat plate holding a liquid substance, and a conical rotor processed to have a conical angle φ ′ facing the flat plate. When the design value of the radius of the bottom surface of the conical rotor is R and the design value of the cone angle of the conical rotor is φ, the location on the conical surface that is 2 / 3R away from the center of the conical rotor in the radial direction and the flat plate The method for positioning a conical rotor of a conical-plate type rotary viscometer, characterized in that the position of the conical rotor is determined so that the distance between the two becomes equal to 2 / 3R · φ. 2. A method for positioning a conical rotor of a cone-plate type rotary viscometer with respect to a flat plate, comprising a flat plate holding a liquid substance and a conical rotor processed to have a conical angle φ ′ facing the flat plate. To determine the reference surface or reference point of the conical rotor, and set the design value of the radius of the bottom surface of the conical rotor to R,
When the design value of the conical angle of the conical rotor is φ, the distance d between the location on the conical surface radially ⅔R away from the center of the conical rotor and the predetermined reference surface or reference point is determined. The distance between the reference plane or the reference point and the flat plate is 2 / 3R · φ ± d (the sign is − when the reference plane or the reference point is located on the top of the conical rotor, and the sign is + when it is in the opposite direction). The position of the conical rotor is determined so as to coincide with (1). 3. A support body that supports the conical rotor on a reference surface of the conical rotor or a support surface that can be in close contact with a reference point, and a movable body that is movable coaxially with the conical rotor and in the direction of the central axis of the conical rotor. And a distance meter that measures a moving distance in the axial direction of the movable body with reference to a position where one surface orthogonal to the central axis of the movable body is in close contact with the support surface of the support body,
The surface of the movable body is ⅔ in a radial direction from the central axis.
When the conical rotor is installed with its reference surface or reference point in close contact with the support surface of the support, the edge of the hole of the movable body is cut into The conical rotor is moved so as to come into contact with the conical surface, and the moving distance of the movable body at that time is obtained by the distance meter, whereby the position on the conical surface radially separated by 2 / 3R from the center of the conical rotor and the conical rotor. The jig used for carrying out the method for positioning the conical rotor of the conical-plate type rotary viscometer according to claim 2, wherein the distance d from the reference plane or the reference point is determined. 4. A support body that supports the conical rotor, a movable body that is coaxial with the conical rotor and that is movable in the central axis direction of the conical rotor, and a movable body that is movable in the central axis direction of the conical rotor. A reference pin driving body whose access to the conical rotor is restricted by a movable body, and one surface of the movable body which is orthogonal to the central axis is ⅔R away from the central axis in the radial direction. With the edge of the hole of the movable body brought into contact with the conical surface of the conical rotor, the driving body is brought closer to the conical rotor until the movable body restricts the reference pin, and the reference pin is conical. By driving into the rotor, the tip of the reference pin of the conical rotor is determined as the reference point of the conical rotor, and the point on the conical surface radially separated by 2 / 3R from the center of the conical rotor and the reference point of the conical rotor. Interval of Is determined as the distance between the tip of the driving body and the surface of the movable body when they are closest to each other. jig.