JPH0214655B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the hardness of granules, and particularly proposes a device that can directly measure the hardness of granular or fine granular drugs by crushing them. It is something.

Measuring the hardness of granular and fine-grained drugs is extremely important in evaluating their physical properties, but conventionally, this measurement involves storing these granules in a ball mill and rotating them to determine their friability. However, with this method, it is impossible to directly know the hardness of each individual granule, and it is also difficult to measure the hardness of individual granules when mixed with other agents such as lubricants. In the case of hardness systems, there are problems such as difficulty in making good measurements, and the development of an apparatus that can measure the hardness of each grain has been awaited.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a granule hardness measuring device that can detect the essential hardness of each granule by squeezing and crushing the granules. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 is a schematic diagram showing the overall configuration of a granule hardness measuring device according to the present invention. In the figure, reference numeral 1 denotes a weighing device consisting of a base plate part 1a on which granules 10 serving as a measurement sample are placed, and a load meter part 1b connected to this so as to measure the load applied to the base plate part 1a. It is placed on a dovetail base 2. This scale 1 is equipped with at least a display 1c that displays a load measurement value (or weighed value) or a terminal 1d that outputs an analog electrical signal according to the load measurement value (the example has both). Especially when using only the display section 1c, it is preferable to use one that can hold the peak value. In addition, this weighing device 1 has a displacement detection means such as a differential transformer connected to the base plate part 1a, and based on the output of this detection means, in order to zero the displacement and therefore the displacement of the base plate part 1a. A so-called electrodynamic balanced type is desirable, which includes an electromagnetic actuator that applies a driving force to a portion connected to the base plate portion 1a, and displays and outputs a value related to the current supplied to the electromagnetic actuator as load information. A microscope 3 is placed on the side of the weighing device 1 in order to observe the granules 10 during the hardness measurement. This is because, in the case of a configuration in which the microscope 3 is located at the same position, the trouble of changing and adjusting the field of view of the microscope 3 in accordance with the progress of the test is relieved. The output terminal 1d is connected to the X input terminal 4x of the XY recorder 4.

5 is located above the center of the base plate portion 1a.
The pressurizer 5 is disposed directly facing the cylindrical column, and has a form in which a downward conical pedestal is connected to the lower end of the cylinder. A sleeve 5c for connection with a drive rod 6a, which will be described later, is fixed thereto. The pressurizer 5 is mounted on a base plate portion 1a which is substantially immovable as the drive rod 6a moves up and down.
The granules 10 between the pressure element 5 and the base plate part 1a are sandwiched between the pressure element 5 and the plate part 1a and crushed between them. That is,
The pressurizer 5 and the plate portion 1a constitute a pair of clamping members that clamp and crush the measurement sample. Mounting plate 5a
A length measurement sensor 7a is attached to a portion of the lower surface of the presser 5 which is outside the position where the presser element 5 is disposed and which faces the base plate portion 1a. The length measurement sensor 7a is provided to measure the dimension between the pressurizer 5 and the base plate part 1a together with the length measurement device main body 7b.The length measurement sensor 7a has a built-in induction coil and a detection coil (both (Some devices also serve as a coil), length measuring device body 7
The length measuring sensor 7a and the base plate part 1a are capable of generating an eddy current in the base plate part 1a made of a conductor by a high frequency current applied to an induction coil from b, and a magnetic field caused by this eddy current can be generated by a detection coil. The distance measuring device itself, which consists of the length measuring sensor 7a and the length measuring device body 7b, is a known device. It is something. The length measuring device main body 7b is equipped with a display section 7c for displaying the length measurement results and a terminal 7d for outputting an analog electrical signal according to the length measurement results, and this output terminal 7d is connected to the Y input terminal 4 of the X-Y recorder 4.
connected to y. Note that the lower end surface of the length measurement sensor 7a is positioned slightly above the lower end surface of the pressure element 5 so as not to prevent the pressure element 5 and the platform portion 1a from clamping and pressing the granules 10. , The zero adjustment of the length measuring device main body 7b is performed to compensate for the difference between the lower end surfaces so that the display on the display section 7c and the output content on the output terminal 7d represent the distance dimension between the pressurizer 5 and the base plate section 1a. Apply.

Reference numeral 6 denotes a pneumatic actuator whose cylindrical body 6b is supported by support means (not shown), in which the cylindrical body 6b and a driving rod 6a loosely fitted concentrically thereto take a vertical posture, and the cylindrical body 6b of the driving rod 6a A sleeve 5c is attached to the outer lower end. The cylindrical body 6b is sufficiently thicker than the drive rod 6a, has a pressurized air supply hole 6c in the center side, and has an enlarged diameter at the upper end over an appropriate length.
There is a ventilation hole 6f on the upper end surface of this part, that is, on the ceiling.
The lower end portion is also enlarged in diameter over an appropriate length, and the lower end opening of the cylinder body 6b is airtightly connected to the periphery of the cylinder body and the opposing portion of the drive rod 6a at the lower end of this expanded diameter portion. A diaphragm 6d is interposed to seal the diaphragm 6d.
Furthermore, a diaphragm 6 is disposed between a position close to the upper end of the driving rod 6a in the cylinder body 6b sealed in this way and a wall surface of the enlarged diameter portion of the upper part of the cylinder body facing thereto.
A diaphragm 6e made of the same material as d is interposed. The upper diameter enlarged portion of the cylindrical body 6b is set to have a narrower cross-sectional area than the lower diameter enlarged portion. In other words, the area of the diaphragm 6d is larger than the area of the diaphragm 6e.

With this configuration, the pressure air supply hole 6
When pressurized air is supplied from c to the space sealed by the diaphragms 6d and 6e of the cylinder 6b, the diaphragms 6d and 6e bulge and deform downward and upward, respectively.
The free ends (inner peripheral ends) of the diaphragms 6d and 6e are intended to be displaced downward and upward, respectively. Since the inner circumferential ends of the diaphragms 6d and 6e are both fixed to the drive rod 6a, the drive rod 6a moves in the direction of the stronger force of the downward and upward deformation forces of the diaphragms 6d and 6e, depending on the difference between them. It is displaced by a corresponding force.

That is, here, since the diaphragm 6d has a wider area than the diaphragm 6e, the drive rod 6a is driven downward by a force equivalent to the area difference. (Note that when the pressure is reduced between the diaphragms 6d and 6e, the drive rod 6a is driven upwards.) Therefore, by keeping the above area difference small, the cylinder body 6b
Drive rod 6 with a force that is sufficiently weak compared to the change in the internal air pressure.
a is driven downward or upward. During this time, the diaphragm 6e also serves to hold the drive rod 6a in a vertical position and concentric with the cylinder 6b.
The diaphragms 6d and 6e may be made of different materials and have different thicknesses, regardless of the difference in area, so that the drive rod 6a is moved in one direction with the supply of pressurized air.

Reference numeral 8 denotes a fixed container placed on a table (not shown), and one end of the upper part of the container is connected to a pressurized air supply hole 6c, and the other end of a communication pipe 11 having a dehumidifier 9 provided in the middle thereof is opened. The container 8 is also provided with a pipe 12 which has one end opened near the bottom and the other end opened above the container.
1. Portions other than the tube 12 are sealed. Reference numeral 13 denotes a movable container suspended from a hanging line 15 wound around a pulley 14, and a drain formed downward at the bottom of the movable container and the pipe 12 are connected by a sufficiently long rubber pipe 16. The upper part of the container 13 is open, and the water 17 injected from here occupies about 1/3 of the container 8 in the illustrated state in which both the bottoms of the containers 8 and 13 are approximately at the same height.
In addition, a movable container 1 which is filled in the tube 12 and the rubber tube 16 and has approximately the same cross-sectional area as the fixed container 8 and is longer than the fixed container 8.
The water surface height in the container 3 is made to be the same as that in the fixed container 8. That is, the tube 12 and the rubber tube 1
A siphon is formed at 6. In addition, containers 8, 1
In the illustrated state in which the bottoms of the containers 3 and 3 are approximately at the same height, the initial connection may be performed so that the upper space of the container 8, the communication pipe 11, and the sealed space of the cylinder body 6b are at atmospheric pressure.

The pulley 14 is fixed to the output shaft of the motor 18, and its forward rotation winds up the hanging line 15, and its reverse rotation lets out the hanging line 15, thereby raising and lowering the movable container 13 and lowering the water level in the fixed container 8. By raising and lowering the pressure in the sealed space, the pressure in the sealed space is changed to displace the diaphragms 6d and 6e, and as a result, the drive rod 6a and hence the pressurizer 5 are moved toward and away from the base plate portion 1a. Reference numeral 18a is a control unit for the motor 18, which performs not only start/stop and forward/reverse control of the motor 18, but also speed governing control using feedback control based on the output of a pulse generator (rotary encoder) interlocked with the motor 18. This is a well-known method. When the ascending speed of the movable container 13 is changed by this speed regulating control, the descending speed of the pressurizer 5 (the approaching speed to the platform portion 1a) is changed, and the pressurizing speed when clamping the granules 10 to crush them is changed. That will happen. Furthermore, movable container 1
3 is preferably configured to move up and down without swaying by means of a plurality of guide columns (not shown) configured to also serve as support legs for the motor 18.

The specific dimensions and specifications of each component mentioned above can be selected as appropriate depending on the object to be measured and the purpose.
In the case of the following granular drugs, the weighing device 1 should be one that can measure up to 20 g in 1 mg units, and the length measuring sensor 7a.
and 1/10 as a length measuring device consisting of the length measuring device main body 7b.
When a pressurizer capable of measuring up to 5 mm in 0 mm increments is used, and the diameter of the lower end surface of the presser element 5 is approximately 2 mm, and the movable container 13 is placed in the position shown in the figure (in this state, the granules to be measured are set or crushed). The separation distance between the pressurizer 5 and the base plate portion 1a (where the removed material is removed) is 10 mm.
It is recommended that the drive system of the pressurizer 5, that is, the specifications from the pneumatic actuator 6 to the motor 18, be selected so that the pressurizer 5 can be lowered at a speed of about 0 to 100 mm/min. Appropriate. In addition, the upper limit position of the presser 5 (lower limit position of the movable container 13) is set as shown in the figure, and a micro switch is provided, for example, in the lifting area of the movable container 13 so that the presser 5 automatically stops at the sample setting position. It is convenient to incorporate the control unit 18a into the control unit 18a and make it related to the start/stop control of the motor 18.

In the apparatus of the present invention constructed as described above, the granules 10 to be measured are placed in the sample setting position shown in the figure, and the granules 10 to be measured are placed in the region immediately below the pressurizer 5 of the platform portion 1a, and the granules 10 are set at a predetermined speed by the operation of the control unit 18a. The motor 18 is rotated in the normal direction, the XY recorder 4 is activated, and the granules 10 are observed using the microscope 13 if necessary.

For example, a chart as shown in FIG. 2 is drawn on the X-Y recorder 4 depending on the crushed state of the granules 10. That is, until the presser 5 comes into contact with the granules 10, the Y output, that is, the separation dimension between the presser and the plate part, decreases, while the X output, that is, the load, is 0.
With contact, the change in the Y output becomes minute, while the X output increases, and at the first crushing, the X output reaches its maximum value, the X output decreases, and the Y output also changes in the direction of decreasing the separation dimension. However, a load is applied again to the small particles generated by crushing, and the X output increases until the particles are crushed, resulting in a maximum value larger than that at the first crushing.
After this second crushing results in a fine particle shape, no further crushing occurs and the X output, that is, the load value becomes overscale. The motor 18 may be stopped when the X-Y recorder 4 monitors the overscale or when the crushing is confirmed a predetermined number of times by microscopic observation. The hardness is evaluated based on the load value at the first crushing (the first peak value), or by the average of the load values at multiple crushings (two times in the example in Figure 2). Furthermore, it may be performed depending on the object to be measured, the purpose of its evaluation, or the correspondence with conventional evaluation methods, such as by averaging the crushing load values for different pressurization speeds.

With the apparatus of the present invention constructed and used as described above, it becomes possible to directly measure the hardness of each grain, which was previously impossible. Therefore, when evaluating the hardness of a drug containing a binder, a lubricant, etc., it is possible to measure the hardness with good reproducibility, regardless of its composition, formulation, etc.

Further, when the displacement and load of the pressurizer are recorded on an X-Y recorder using the apparatus of the present invention, the process leading to crushing can also be accelerated.

In addition, in the device of the present invention, the clamping member or presser is differentially moved by the difference in deformation force between two diaphragms deforming in opposite directions, so that mechanical frictional force is applied to the drive section of the presser. It is possible to perform measurements by displacing the presser without any vibration and without any action.
In addition, by setting the difference in deformation force to an appropriate value, an extremely weak force can be applied to the pressurizer, and a load of several mg, which is suitable for measuring the hardness of granular and fine granular drugs, can be easily obtained. Can be done. In addition to the fact that no mechanical frictional force acts as described above, this embodiment is configured to change the internal pressure of the cylindrical body 6b by raising and lowering the container 13, so that the granules are gradually and without vibrations. Since the applied load can be increased, there is no possibility that variations in the manner of increasing the load will be superimposed on variations in the hardness of the individual objects to be measured, and reliability is extremely high. Further, when the dehumidifier 9 is provided in the middle of the communication pipe 11 as in the embodiment, it is effective in preventing rust of the diaphragm and other pneumatic actuators, and stable use over a long period of time is possible. Note that the liquid contained in the containers 8 and 13 is not limited to water, and may be silicone oil or the like.

If you only need to know the peak value of the load at the time of crushing, use a load cell that can hold the peak value, stop the motor as soon as the crush is confirmed by observation with the microscope 3, and then check the load cell. A configuration that records the peak value of is also sufficient. Needless to say, in this case, a length measurement sensor or the like is not required.

As described above, in the present invention, the movable clamping member that crushes the granules is supported by a diaphragm, and is displaced by changes in atmospheric pressure, so that no mechanical frictional force is applied to the clamping member. Therefore, the clamping member is driven by the difference in the amount of deformation of the two diaphragms deforming in opposite directions. It is possible to apply an extremely weak load to the granules, and when applied to the measurement of the hardness of granular and fine granular drugs, it has excellent effects such as extremely high measurement accuracy and reliability.

[Brief explanation of drawings]

The drawings show examples of the present invention, and FIG. 1 is a schematic diagram showing the overall configuration of the apparatus of the present invention, and FIG. 2 is a chart showing an example of measurement results. DESCRIPTION OF SYMBOLS 1... Weighing device, 1a... Base plate part, 1b... Load meter, 4... X-Y recorder, 5... Pressure element, 6...
...Air pressure actuator, 7a...Length measurement sensor,
8, 13... Container, 18... Motor.

Claims (1)

[Scope of Claims] 1. A pair of clamping members arranged so as to be able to approach and separate in order to clamp and crush granules, a load cell connected to one clamping member, and the other clamping member. a rod connected to the other clamping pressure member, and a drive means for moving the other clamping pressure member toward and away from the one clamping pressure member, and the drive unit includes a rod connected to the other clamping pressure member. and a cylindrical body which is loosely fitted into the rod and configured to supply pressurized air, and at two positions in the axial direction of the cylindrical body, due to changes in the air pressure inside the cylindrical body, the axial direction of the cylindrical body is mutually changed. It is characterized by including a pneumatic actuator that is interposed between the cylinder and the rod so as to deform in opposite directions, and includes two diaphragms that drive the rod in the axial direction by the difference in deformation force. Hardness measuring device for granules. 2. The driving means includes a pneumatic actuator, two liquid storage containers that are connected to each other by a flexible siphon, and a speed-controlled motor that is connected to one of the liquid storage containers to move the liquid container up and down. 2. The granule hardness measuring device according to claim 1, wherein a non-liquid storage space is provided in the upper part of the other liquid storage container, and the space is connected in communication with the cylinder of the pneumatic actuator. 3. A pair of clamping members arranged opposite each other so as to be able to approach and separate in order to clamp and crush the granules, a length measuring means for measuring the distance between the clamping members, and a length measuring means connected to one of the clamping members. a load cell connected to the other clamping pressure member and moving the other clamping pressure member toward and away from the one clamping pressure member, and measuring the length measuring means and the load cell. means for displaying results in association with each other; the driving means includes a rod connected to the other clamping pressure member; a cylinder loosely fitted to the rod and configured to supply pressurized air;
At two positions in the axial direction of the cylinder, the rod is interposed between the cylinder and the rod so that they deform in opposite directions in the axial direction of the cylinder due to changes in the air pressure inside the cylinder, and the deformation A granular hardness measuring device comprising a pneumatic actuator having two diaphragms that drive a rod in its axial direction using a force difference. 4. The driving means includes a pneumatic actuator, two liquid storage containers connected to each other by a flexible siphon, and a speed-controlled motor connected to one of the liquid storage containers to move it up and down. 4. The granular hardness measuring device according to claim 3, wherein a non-liquid storage space is provided in the upper part of the other liquid storage container, and the space is connected in communication with the cylinder of the pneumatic actuator.