JPH063410B2 - Rotational viscometer with pivot protection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary viscometer that supports a rotor shaft and a rotor by means of a pivot, and in particular, when the viscosity is not measured, the pivot is separated from its bearing to protect the pivot. The present invention relates to a rotational viscometer with a protective device.

b. 2. Description of the Related Art Conventionally, in this type of viscometer, the operating principle of measurement (constant speed method) is as shown in FIG. 5, in which a rotary drive shaft 2 of a drive motor (for example, a synchronous motor) 1 is attached to a scale plate 3. The rotor shaft 5 is connected to the lower end 2 ′ of the drive shaft 2 via the spring 4, and the rotor 7 immersed in the sample solution 6 whose viscosity is to be measured is attached to the lower end of the rotor shaft 5. Has been. On the other hand, a pointer 8 extending above the scale plate 3 is attached to the rotor shaft 5, and the relative angular displacement amount of the drive shaft 2 and the rotor shaft 5 is read by the position of the pointer 8 on the scale plate 3. You can

With such a configuration, the rotor shaft 5 and the drive shaft 2 are arranged so that the torque generated in the rotor 7 due to the viscosity of the sample liquid 6 as the rotor 7 rotates is balanced by the elastic force of the spring 4.
From the amount of angular displacement when angularly displaced with respect to
The viscosity of can be measured. That is, if the torsion spring constant of the spring 4, the size of the rotor 7 and the number of rotations thereof are determined, the finger index of the pointer 8 on the scale plate 3 is proportional to the viscosity of the sample solution 6,
The viscosity of the viscous sample liquid can be calculated from the finger of the pointer 8.

In the above description of the measurement principle, the operation principle is shown assuming that the rotor shaft 5, the rotor 7, and the pointer 8 are connected to the lower end 2'of the drive shaft via the spring 4. However, in such a structure, the shaft system does not work. Since it is stable, the cross-sectional structure of an actual rotational viscometer
Shown in Figures and 7. FIG. 7 is an enlarged view of part A (pivot and its bearing) of FIG.

The angular displacement of the drive shaft 2 with respect to the rotor shaft 5 can be read as the finger index of the pointers 8 and 8a on the scale plates 3 and 3a as shown in FIG. 5 or 6, but as shown in FIG. Further, by interposing an angle detector 13 such as a rotary differential transformer between the drive shaft 2a and the pointer shaft 9a, the angular displacement amount can be transmitted as an electric signal. However, the principle of measurement is exactly the same as in FIG. Below, scale plate 3,
An angle detector including 3a and pointers 8 and 8a will be described as an example.

6 and 7, the rotor shaft 5a has its own weight supported by a pivot 11, a bearing (actually, a jewel bearing) 12, and a pointer shaft 9 extending upward through a U-shaped connecting member 10. The runout at the upper end is due to the pin 13 penetrating into the central shaft hole of the drive shaft 2a.
It is resting. Regarding other members, the drive motor 1a, the scale plate 3a, the spiral spring 4a, the sample liquid 6a, the rotor 7a, and the pointer 8a are shown in correspondence with the respective members in FIG. 1'a
Is a transmission of the drive motor 1a.

With such a structure, the contact surfaces of the pivot 11 and the bearing 12 include the rotor 7a assembled to the rotor shaft 5a, the rotor shaft 5a, the U-shaped connecting member 10, the pointer shaft 9, and the pointer 8a. Since the weight is applied as a thrust load, the rotor shaft 5a
Produces a friction torque for the rotation of. On the other hand, since the viscous resistance torque acting on the rotor 7a may be extremely small depending on the sample liquid to be measured, the pivot friction torque influences the measurement in the measurement of the low viscosity liquid and deteriorates the measurement accuracy.

Therefore, by reducing the spherical radius of the tip of the pivot 11 that contacts the bearing 12 to reduce the friction torque, this type of viscometer is compared to other industrial instruments that use normal pivots. , The load conditions are becoming severe.

Further, when the viscosity measurement is finished, in order to clean the rotor 7a, a so-called attachment / detachment operation is required to remove the rotor 7a from the rotor shaft 5a or replace it with another rotor. In such an operation, it is the actual situation that a failure frequently occurs such that an excessive force is applied to the pivot 11 to deform the pivot 11 or damage the bearing 12. There was also a problem of deterioration due to vibration and shock when the viscometer was transported.

Even during normal handling in this way, external force is applied due to attachment / detachment operations such as rotor replacement, and the pivot 11 and bearing 12
The conditions under which the viscometer can be damaged are extremely special compared to the conditions under which the pivot of a general industrial instrument is used, and the viscometer user needs to pay close attention to the handling operation.

In such a rotational viscometer, a rotational viscometer equipped with a protection mechanism for protecting the pivot 11 at the time of attachment / detachment operation such as rotor replacement and at the time of transportation of the viscometer was devised by one of the inventors of the present application, and has already been applied. Registered (Actual Kosho 52-1
No. 0391).

As shown in FIG. 8, the present invention is provided with a cylindrical sleeve 18 slidable in the axial direction guided by an inner wall surface of a lower case 17 accommodating a pivot 11 and a bearing 12 thereof. A disc 19 is provided which is screwed to a screw portion 18a provided on the lower portion of the inner surface. The disc 19 has a hole in the center thereof through which the rotor shaft 5a freely passes, and an internal gear 20, for example, is fixed to the upper surface of the disc 19 to form a lower fitting member. As the upper fitting member, for example, an external gear having the same step pitch as the internal gear 20
21 is fixed to the rotor shaft 5a, and as described later, when the sleeve 18 moves slightly upward from the position of the lowermost end thereof, both gears 20 and 21 start to mesh with each other, so that the position and The thickness is set. On the other hand, one end of the pin 22 that is inserted through the opening 17a provided in the side wall of the lower case 17 is a sleeve 18, and the other end is a ring-shaped handle 23 that can slide up and down along the outer peripheral surface of the lower case 17. Mounting. Opening 17a
When the pin 22 is in contact with the lower end of the gear, the internal gear 20 and the external gear 21 are completely disengaged from each other, and when the pin 22 is in contact with the upper end of the pin 22, both gears 20 and 21 are completely meshed with each other, and Disk 1
It is pushed up to 9 so that the pivot 11 and its bearing 12 are completely separated. Further, 24 is a limit switch using a micro switch, and when the sleeve 18 moves upward and reaches a position where the internal gear 20 and the external gear 21 start to mesh with each other, the upper end of the sleeve 18 moves to the limit switch 24. The protruding pin 24a is pushed to operate the limit switch 24 to open the power supply circuit of the drive motor 1a.

With this configuration, when the rotational viscometer is not measuring, the sleeve 18 is positioned above to separate the pivot 11 from the bearing 12, and at the same time, the gears
By 20,21, the rotor shaft 5a is prevented from rotating,
Even when the viscometer is transported or the rotor 7a is attached or detached, the pivot 11 and its bearing 12 are not damaged.

c. However, in the conventional pivot protection mechanism described above,
When the user of the rotational viscometer finishes the viscosity measurement, the rotor 7a
Whenever the viscometer is used again after replacing the rotor 7a, the operation of sliding the ring-shaped handle 23 downward is required when the viscometer is replaced after the rotor 7a is replaced. Was needed. In particular, it is important to move the ring-shaped handle 23 upward when replacing the rotor 7a.
There has been a problem that accidents that damage the bearing 11 and its bearing 12 still occur frequently.

The present invention has been made in view of the above points, and its object is to solve the above-mentioned problems, and when the rotational viscometer is not used, the pivot and its bearing are always separated from each other, and It is an object of the present invention to provide a rotational viscometer with a pivot protection device which, when used, always brings the pivot and its bearing into contact with each other.

Another object of the present invention is to keep the pivot and its bearing in contact with each other when using the viscometer,
It is an object of the present invention to provide a rotary viscometer with a pivot protection device equipped with a control means that enables viscosity measurement.

d. Means for Solving the ProblemsThe constitution of the present invention for achieving the above-mentioned object is as follows: 1) A drive shaft equipped with an angle detector such as a scale plate which is rotationally driven by a drive unit, and a spring from the drive shaft. Pointer shaft that is elastically coupled with the pivot portion thereof, that is, the input rotation shaft of the detector, and the input rotation shaft are concentrically coupled via a U-shaped coupling member, and the shaft thereof. A rotor rotating shaft having upper fitting members provided therein, a case accommodating these rotating shafts, an inner surface of the case being slidably inserted and supported, and a lower fitting member provided on one end surface side thereof. A sleeve, and by sliding the sleeve in one direction, the fitting members are engaged with each other to restrain the input rotary shaft and the rotor rotary shaft, and the pivot portion and the bearing thereof. Parts and each other In those so as to between the sleeve driving means for sliding said sleeve,
Position detection that transmits a position signal when the sleeve D is slid to engage or disengage the two fitting members with each other, and the pivot portion and its bearing portion are completely separated from or in contact with each other. And means for controlling the drive of the sleeve drive means and the drive section based on a signal from the plate detection means.

2) When the control means starts the viscosity measurement, a. Simultaneously with the start of the operation, the sleeve driving means slides the sleeve to release the engagement between the fitting members and to bring the pivot portion and the bearing portion into contact with each other. B. When the sleeve drive means is stopped by the contact signal from the position detection means, the drive unit is rotationally driven to perform viscosity measurement, and when the viscosity measurement is finished, c. Stopping the rotational drive of the drive part and sliding the sleeve in the opposite direction by the sleeve drive means to separate the pivot part and its bearing part, d. A sequence control for stopping the sleeve driving means is performed by a separation signal from the position detecting means.

e. The rotational viscometer with the pivot protection device configured as described above is normally in a state where the pivot and its bearing are separated from each other when not in use, and when the drive motor is turned on during use, it is controlled by the control means. , Prior to driving the motor,
The separated pivot and its bearing are automatically brought into contact with each other to release the rotor shaft, and then the rotation of the motor is started.

When viscosity measurement is completed and the drive motor is stopped, the rotor shaft is automatically clamped (restrained) by the control of the control means and the pivot and its bearing are separated from each other to restore the normal state. This completely protects the pivot and its bearings without tampering with the measuring procedure.

f. Examples Hereinafter, preferred examples of the present invention will be exemplarily described in detail with reference to the drawings.

FIG. 1 is a sectional view of a main part of a rotary viscometer with a pivot protection device showing an embodiment of the present invention. In the figure,
Parts that are the same as or correspond to those in the figure are assigned the same reference numerals and explanations thereof are omitted.

The L-shaped metal fitting 30 is fixed to the upper end of the sleeve 18, and two limit switches (microswitches in this embodiment) 31 and 32 are arranged on the upper and lower sides with one side 30a therebetween. When the sleeve 18 moves upward, the pivot 11 and its bearing 12 are separated from each other, and the rotor shaft 5a is clamped (restrained), the one side 30a of the L-shaped metal fitting 30 operates the limit switch 31. Output a contact signal. On the contrary, the sleeve 18 moves downward and the pivot
When the rotor shaft 5a and the bearing 12 thereof come into contact with each other and the rotor shaft 5a is released, the limit switch 32 similarly operates to output a contact signal. In addition, one of the upper ends of the sleeve 18 has a block 3 provided with a screw hole 33a.
3 is fixed, and in the screw hole 33a of this block 33,
A screw shaft 34a connected to the output shaft of a clamping motor 34 fixed to the viscometer body is screwed. Therefore, by driving the clamping motor 34, the screw shaft 34a rotates in the forward or reverse direction, and the sleeve 18 moves upward or downward together with the block 33 screwed to the screw shaft 34a to move the pivot 11 and its bearing. 12 and separate or contact.

The control device 35 controls the drive motor 1a and the clamping motor 34 in a predetermined sequence according to a start or stop command.

FIG. 2 is a state transition diagram showing a state at each stage of a series of sequences of this viscometer. The operation of the viscometer will be described with reference to the figure. In the stopped state, the pivot 11 and the bearing 12 thereof are separated from each other, and the rotor shaft 5a is clamped and stopped. This state is the normal state.

When using a viscometer, when pressing a start switch (not shown) of the control device 35, the rotor shaft release operation state of
The control device 35 drives the clamping motor 34 to rotate its screw shaft 34a, slide the sleeve 18 downward to bring the pivot 11 into contact with the bearing 12, and release the rotor shaft 5a. At a position where the release is completely released, the limit switch 32 is operated by one side 30a of the L-shaped metal fitting 30 to stop the clamping motor 34. After the stop, the control device 35 drives and rotates the drive motor 1a to set the viscosity measurement state to measure the viscosity. Next, when stopping this viscous form, press a stop switch (not shown) of the control device 35,
Of the rotor shaft clamp operation state, the drive motor 1a is stopped, then the control device 35 drives the clamping motor 34 in the opposite direction to reversely rotate the screw shaft 34a,
By sliding the sleeve 18 upward, the pivot 11 and its bearing
12 and are separated from each other, and the rotor shaft 5a is clamped.
That is, after the rotor shaft clamping operation state of (1), the original normal state of the viscometer stopped state is restored.

In this way, with respect to the rotational viscometer, the control device 35 enters the viscosity measurement state from the normal state of the viscometer stop through the rotor shaft release operation state, and after the viscosity measurement is completed, the viscometer is stopped and the rotor shaft clamp operation state is set. It suffices to perform such a series of sequence control. According to a series of sequence control by the control device 35, conventionally, the user has
Forgetting to operate the release and clamp of 5a, it is possible to completely eliminate the accident caused by this.

FIG. 3 is an example of a time chart of a sequential operation of each part by the control device 35, and FIG. 4 is a control circuit diagram thereof (when the viscometer is stopped). In the figure, START SW is a start push button switch, STOP SW1 is a stop push button switch, STOP SW2 is a clamp motor clamp switch, M1 is a viscometer drive motor, M2 is a clamp motor, X1, X2, X3 is a relay, and LS1a, LS1b, LS2b are limit switch contacts.

In this embodiment, a case where a motor is used as an actuator for sliding the sleeve 18 up and down is shown, but not limited to a motor, a solenoid, an electrostrictive actuator, a magnetostrictive actuator or the like can be used to obtain a required sliding stroke. If it can, it can be fully functional. Further, the limit switches 31 and 32 are not limited to the micro switches, but may be any switches that can detect the position using light, magnetism or the like. Further, these limit switches can be omitted if the actuator has a constant stroke.

That is, the technique of the present invention is not limited to the technique in the above-described embodiment, and may be implemented by means of another aspect having a similar function. Further, the technique of the present invention may be modified in various ways within the scope of the above configuration. Can be added.

g. EFFECTS OF THE INVENTION As is apparent from the above description, according to the present invention, in the conventional rotational viscometer, the drive means for sliding the sleeve and the both fitting members by sliding the sleeve are mutually connected. Position detection means for transmitting or receiving a position signal when engaging or disengaging with the pivot part and separating or contacting the pivot part and its bearing part from each other, and the drive based on the signal from the position detection part. Since the viscometer is not in use, the pivot and its bearing are always completely separated from each other because the viscometer is provided with a control means for driving and controlling the means. To be in complete contact. In addition, when using the viscometer, the pivot means and the bearing thereof must be brought into complete contact with each other by the sequence control of the control means, and then the viscometer drive unit is rotationally driven to perform the viscosity measurement. Protect.

In other words, (1) forgetting the clamping operation, removing and replacing the rotor, cleaning and cleaning the rotor will not deform or damage the pivot and damage its bearings.

(2) The pivot and its bearing are not damaged by shock or vibration when transporting or moving the viscometer without forgetting the clamp operation.

(3) Operations such as rotation and stop of the viscometer may be performed by simply pressing the start push button switch and the stop push button switch, which improves the operability.

(4) Even the unskilled person can easily operate the viscometer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a rotary viscometer with a pivot protection device showing an embodiment of the present invention, FIG. 2 is a state transition diagram showing the state of each step of the sequence, and FIG. FIG. 4 is a time chart showing a sequential operation, FIG. 4 is a control circuit diagram of a control device, FIG. 5 is a principle diagram of measurement of a rotary viscometer, and FIG. 6 is a sectional view showing a structure of a conventional rotary viscometer. FIG. 7 is an enlarged view of part A of FIG. 6, FIG. 8 is a cross-sectional view showing a conventional pivot protection mechanism, and FIG. 9 is a conventional rotational viscometer, which shows an angle detector that transmits an angular displacement amount as an electric signal. It is sectional drawing which shows the structure of the attached viscometer. 1a ... Drive motor, 5a ... Rotor shaft, 11 ... Pivot, 12 ... Bearing, 18 ... Sleeve, 31,32 ... Limit switch, 34 ... Clamping motor, 35 ... Control device.

Claims (2)

[Claims] 1. A drive shaft equipped with an angle detector which is rotationally driven by a drive unit, and a pointer shaft which is elastically connected to the drive shaft via a spring and has its pivot portion bearing, that is, the detection. An input rotary shaft of a container, a rotor rotary shaft concentrically connected from the input rotary shaft via a connecting member, and an upper fitting member provided on the shaft, a case for housing these rotary shafts, The case comprises a sleeve slidably inserted and supported on the inner surface of the case, and a lower fitting member is provided on one end surface side of the case. To restrain the input rotary shaft and the rotor rotary shaft,
In the one in which the pivot portion and the bearing portion thereof are separated from each other, sleeve driving means for sliding the sleeve,
Sliding the sleeve to engage the two fitting members with each other,
Alternatively, the sleeve driving means is disengaged, and position detecting means for transmitting a position signal when the pivot portion and the bearing portion are completely separated from or in contact with each other and the signal from the position detecting means are used. And a rotation viscometer with a pivot protection device, which comprises: a control unit that drives and controls the drive unit. 2. The control means, when starting the viscosity measurement, a. Simultaneously with the start of the operation, the sleeve driving means slides the sleeve to release the engagement between the fitting members and to bring the pivot portion and the bearing portion into contact with each other. B. When the sleeve drive means is stopped by the contact signal from the position detection means, the drive unit is rotationally driven to perform viscosity measurement, and when the viscosity measurement is finished, c. Stopping the rotational drive of the drive part and sliding the sleeve in the opposite direction by the sleeve drive means to separate the pivot part and its bearing part, d. The rotational viscometer with a pivot protection device according to claim 1, wherein sequence control for stopping the sleeve driving means is performed by a separation signal from the position detecting means.