JPH0747190Y2 - Rotary powder compression molding machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary powder compression molding machine for compressing powder to form tablets and the like, and in particular,
In addition, it relates to the improvement of the portion that supports the lower roll.

[0002]

2. Description of the Related Art As a rotary powder compression molding machine for molding tablets, electronic parts, etc., a rotary disk is horizontally rotatably arranged through a vertical shaft in a frame, and a plurality of mortars are mounted on the rotary disk. In addition to being provided at a predetermined pitch, the upper and lower punches are held above and below each die so that they can slide up and down, and the upper and lower punches with the tip of the punch inserted in the die are placed between the upper and lower rolls. It is known that the powder filled in the die is compression-molded by passing the powder.

In such a molding machine, the supporting shaft of the upper roll is supported on the upper part of the frame via a pair of bearings, and the supporting shaft of the lower roll is supported on the lower part of the frame via a pair of bearings. There is.

In order to measure the load acting on the roll during tableting, for example, the upper roll supporting portion located between both bearings of the support shaft is eccentric, and one end of the support shaft is placed outside the bearing. There are many cases where the load cell is extended and an arm is fixed to the free end and the load cell is biased by the tip of the arm.

Further, in this type of molding machine, for example, in order to make it possible to adjust the tableting thickness and to absorb the impact when an abnormal reaction force acts on the roll during tableting, for example, a support is provided. The lower roll supporting portion located between both bearings of the shaft is eccentric, one end of the support shaft is extended to the outside of the bearing, and a worm wheel is attached to the extending free end of the worm wheel. Generally, the shock absorber is made to mesh with the worm of such a shock absorber.

[0006]

In a rotary powder compression molding machine of this type, however, the contact surface of the arm with respect to the load cell is easily worn, and the wear causes the load cell pressing direction to change improperly. There is a problem that the detected value is likely to be wrong. Further, in such a molding machine, it is pointed out that the meshing portion between the worm wheel and the worm also undergoes severe wear.

By the way, such wear is remarkable as compared with a normal contact portion or a meshing portion, and therefore the inventors of the present invention have conducted extensive studies to find out the cause thereof. As a result, they found that the wear was caused by the bending of the support shaft. That is, since the conventional support shaft is supported by a pair of bearings located on both sides of the roll, if a large load is applied to the roll during tableting, the support shaft bends and extends outward from the bearing. The free end is tilted. Therefore, a complicated movement due to bending is added to the rotation of the arm attached to the extended free end of the support shaft, and the pressure receiving end of the load cell is designed to be pressed at a right angle by the contact surface of the arm. Nevertheless, it has been found that a slight sliding in the surface direction is caused between the pressure receiving end and the contact surface, and the contact surface is worn. Further, for the same reason, it has been found that the teeth of the worm wheel attached to the extended free end of the support shaft are excessively slid at the meshing portion between the worm wheel and the teeth are abnormally worn.

The present invention has been made based on the results of the above investigation, and an object of the present invention is to provide a rotary powder compression molding machine which can effectively eliminate the above-mentioned problems with a simple structure. .

[0009]

The present invention takes the following means in order to achieve such an object. That is, in the invention according to claim 1 of the present application, a rotary disk is arranged so as to be horizontally rotatable via a vertical shaft, a plurality of dies are provided on the rotary disk at a predetermined pitch, and upper punches are provided above and below each mortar. And the lower punch is held so that it can slide up and down, and the upper and lower punches with the tip of the punch inserted into the die are passed between the upper roll and the lower roll to compress and mold the powder filled in the die. In the rotary powder compression molding machine configured as described above, the support shaft supporting the roll is supported by the first, second, and third bearings, and the eccentric portion located between the first and second bearings of the support shaft has the above-mentioned structure. The roll is rotatably mounted, and an arm member for urging the load detection element is attached to a portion located between the second and third bearings.

Further, in the invention according to claim 2 of the present application, the rotary disk is arranged so as to be horizontally rotatable via the vertical shaft, and a plurality of dies are provided on the rotary disk at a predetermined pitch, and the upper and lower dies of each dies are arranged. The upper and lower punches are held so that they can slide vertically, and the powder filled in the die is passed by passing the upper and lower punches with the tips of the punches inserted into the die between the upper roll and the lower roll. In a rotary powder compression molding machine configured to perform compression molding, a support shaft supporting a roll is supported by first, second, and third bearings, and an eccentricity located between the first and second bearings of the support shaft. The roll is rotatably mounted on a portion of the roller, and a worm wheel for transmitting the rotation of the support shaft to a shock absorber is attached to a portion located between the second and third bearings. And

[0011]

According to the invention of claim 1 of the present application, the support shaft for supporting the roll is supported by three bearings.
That is, in order to urge the load detecting element to the portion located between the first and second bearings that support the support shaft, and the portion located between the second and third bearings. The arm member of is attached. In this way, the roll mounting portion and the arm member mounting portion are each a shaft portion sandwiched between the two bearings, and when the roll mounting portion bends, the bearing causes displacement in the other portion. Doing is suppressed. Therefore, the contact surface of the arm member of the load detecting element is not always displaced with respect to the load detecting element, so that the contact surface is not worn and accurate load detection can be performed for a long period of time. .

According to the second aspect of the present invention, similarly to the first aspect of the invention, since the support shaft is supported by the bearings at three points, it is attached to the portion located between the second and third bearings. The worm wheel is not affected by the bending of the roll mounting portion. Therefore, the worm wheel does not tilt even when the roll mounting portion bends, wear of the meshing portion between the worm wheel and the worm is suppressed, and the roll height adjustment accuracy is not deteriorated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a rotary powder compression molding machine 1 according to the present invention.
The overall configuration of 00 is shown. However, in order to clarify the structure of the upper roll portion, AA shown in FIG.
It is shown by the cross section along the line.

In this rotary powder compression molding machine 100, a rotary disk 3 is disposed in a frame 1 so as to be horizontally rotatable via a vertical shaft 2, and a plurality of mortars 4 are provided on the rotary disk 3 at a predetermined pitch. At the same time, an upper punch 5 and a lower punch 6 are held above and below each die 4 so as to be vertically slidable. When the tips of the upper pestle 5 and the lower pestle 6 are inserted into the mortar 4, when they are passed between the upper roll 8 and the lower roll 9, the powder filled in the mortar 4 can be compression-molded. An upper roll 8 and a lower roll 9 are arranged above and below the turntable 3 about the vertical shaft 2. A powder filling mechanism 7 for filling the powder in the mortar 4 is attached from above the rotary disc 3 toward the rotary disc 3.

A vertical shaft 2 supported by a bearing 21 is arranged at a substantially central portion of the frame 1, and a worm wheel 22 is fixed near the lower end of the vertical shaft 2, and the worm wheel 22 is attached to the worm wheel 22. The rotational driving force of the motor 25 is transmitted via the worm 23 and the belt 24. A turntable 3 which is divided into three functional parts is fixed near the upper end of the vertical shaft 2. The turntable 3 includes a lower punch holding portion 31 which is provided in a lower portion of the turntable 3 and which holds the lower punch 6 slidably in the vertical direction, and an upper punch which is provided in an upper portion and holds the upper punch 5 slidably in the vertical direction. Holding part 3
2, and a die portion provided between the upper punch holding portion 32 and the lower punch holding portion 31 and provided with a plurality of die mounting holes for detachably fitting the die 4 on the same circumference. And 33. The upper punch holding part 32 and the lower punch holding part 31 are the upper punch 5
Also, a plurality of punch holding holes for slidably holding the lower punch 6 are provided respectively. In this turntable 3, the lower punch 6
The upper punch 5 and the mortar 4 are provided with punch-holding holes and mortar mounting holes, respectively, so that the centers thereof are located on the same straight line in the vertical direction.

The upper punch 5 held on the turntable 3 is guided to the highest position in the vicinity of the powder filling mechanism 7 by a guide rail 51 mounted near the upper end of the vertical shaft 2, and reaches the upper roll 8. On top of that, it is designed to be guided to a lower position where it enters under the roll 8. Further, the lower punch 6 is a lowering device 61 provided on the lower side of the turntable 3.
After being compressed by the lower roll 9,
When the molded product molded by compression is taken out from the die 4, it is guided to the highest position.

The upper roll 8 and the lower roll 9 form a pair in the upper and lower sides, each of which is composed of a pair of rolls for precompression 8A, 9A and main compression rolls 8B, 9B. In addition, in FIG. 1, both the upper roll 8 and the lower roll 9 are shown by the cross section along the line AA shown in FIG. The punches 5 and 6 are precompression rolls 8A and 9A, respectively.
After that, the pre-compression rolls 8A, 8A,
9A, the main compression rolls 8B, and 9B are arranged in this order. The upper roll 8 and the lower roll 9 include a first bearing S1, a second bearing S2, and a third bearing S3 in one bearing block SB.
It is attached to an eccentric portion OF of the support shaft AX which is supported via the shaft center eccentric from the shaft center. The support shaft AX is supported at three places, and from the vertical shaft 2 side, the first bearing S1,
The second bearing S2 and the third bearing S3 are arranged in this order. The first bearing S1 and the third bearing S3 respectively support both ends of the support shaft AX, and the second bearing S2 supports substantially the central portion of the support shaft AX. With such a bearing arrangement, the upper roll 8 and the lower roll 9 are rotatably mounted between the first bearing S1 and the second bearing S2 via the bearing.

A load cell lever LL serving as an arm member for urging a load cell LC serving as a load detecting element is provided between the second bearing S2 and the third bearing S3 on the support shaft AX to which the upper roll 8B for main compression is attached. Has been attached. The load cell lever LL is attached around the axis of the support shaft AX, and is constantly urged toward the load cell LC by the load cell spring LS. In addition, the support shaft AX to which the main compression lower roll 9B is attached is provided with a shock absorber DA for rotating the support shaft AX between the second bearing S2 and the third bearing S3.
A worm wheel WW for transmission to the. The shock absorber DA includes a stopper ST that stops the downward movement of the worm wheel WW, a worm W that meshes with the worm wheel WW, a rotary shaft SA to which the worm W is attached, and a rotary shaft SA that is attached upward in the thrust direction. A spring SP for urging, a motor OM with a torque limiter for rotating the rotary shaft SA by a desired amount, and a rotary shaft S.
And a potentiometer PM for detecting the rotation amount of A. In this shock absorber DA, when the motor OM is operated to rotate the rotating shaft SA, the rotation causes the worm wheel WW to swing upward or downward, and the support shaft AX to rotate clockwise or counterclockwise, The height of the main compression lower roll 9B can be slightly changed, and when an abnormal load acts on the support shaft AX, the spring SP is compressed and the worm wheel WW moves downward together with the rotation shaft SA. However, it is designed to absorb abnormal loads. As such a shock absorber DA itself, one well known in the art can be widely used, and for example, the one disclosed in Japanese Patent Publication No. 53-31464 may be used.

In such a structure, a very strong compressive force is temporarily applied to the upper roll 8 and the lower roll 9 via the upper punch 5 and the lower punch 6 during compression. The upper and lower support shafts AX may slightly bend between the first and second bearings S1 and S2 due to the compressive force at this time, but the bending causes the end portion of the support shaft AX to be inclined or displaced. Do the third bearing S
3 can effectively prevent it. for that reason,
The load cell lever LL attached to a position between the second bearing S2 and the third bearing S3 of the support shaft AX is the load cell L.
It does not slide up and down with respect to C, and urges the load cell LC according to the pressure applied to the main compression upper roll 8B. As described above, since the load cell lever LL can be prevented from slightly sliding, wear at the contact point between the load cell lever LL and the load cell LC is suppressed, and accurate compression force measurement can be performed for a long period of time. Similarly, in the support shaft AX of the lower roll 9, the tilting operation of the worm wheel WW attached to the portion between the second bearing S2 and the third bearing S3 can be prevented, and the worm wheel WW and the worm W can be prevented from tilting. The meshing portion does not wear due to excessive sliding, and the height of the main compression lower roll 9B can be accurately adjusted.

The present invention is not limited to the embodiment described above.

In addition, the configuration of each part is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0023]

As described in detail above, according to the first aspect of the present invention, the support shaft for supporting the roll is supported by the first, second and third bearings at three points, and the roll is mounted. Since the portion where the roll is mounted and the portion where the arm member is attached are divided by the bearing, even if the eccentric portion where the roll is mounted bends, the arm member slides on the load detection element surface. Can be prevented, unnecessary wear can be suppressed, and as a result, the compression force can be accurately detected for a long period of time.

The invention of claim 2 of the present application is based on claim 1.
Since the support shaft is supported by the bearings as in the invention, the worm wheel does not tilt even if the eccentric part bends, thus suppressing the slight wear of the meshing part between the worm and the worm wheel. Therefore, even when an abnormal load is applied, the load can be transmitted to the shock absorber and damage to the support shaft can be prevented.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a rotary powder compression molding machine according to an embodiment of the present invention.

FIG. 2 is a plan view showing an enlarged main part of the embodiment.

FIG. 3 is a side view showing an enlarged main part of a support shaft to which the upper roll of the embodiment is attached.

FIG. 4 is a side view showing an enlarged main part of a supporting shaft to which a lower roll is attached according to the embodiment, in a partial cross section.

[Explanation of symbols]

 1 ... Frame 2 ... Vertical shaft 3 ... Rotating plate 4 ... Mortar 5 ... Upper punch 6 ... Lower punch 8 ... Upper roll 9 ... Lower roll AX ... Spindle DA ... Shock absorber LC ... Load cell LL ... Load cell lever OF ... Eccentric part S1 ... 1st bearing S2 ... 2nd bearing S3 ... 3rd bearing W ... Worm WW ... Worm wheel

Claims (2)

[Scope of utility model registration request] 1. A rotary disk is horizontally rotatably arranged via a vertical shaft, and a plurality of dies are provided on the rotary disk at a predetermined pitch, and upper and lower punches are vertically slid above and below each mortar. Rotating powder compression that holds the powder as it is possible and compresses the powder filled in the die by passing the upper and lower punches with the tip of the punch inserted in the die between the upper roll and the lower roll. In a molding machine, a support shaft supporting a roll is supported by first, second, and third bearings, and the roll is rotatably mounted on an eccentric portion of the support shaft located between the first and second bearings. At the same time, the rotary powder compression molding machine is characterized in that an arm member for urging the load detection element is attached to a portion located between the second and third bearings. 2. A rotary disk is horizontally rotatably arranged via a vertical shaft, and a plurality of dies are provided on the rotary disk at a predetermined pitch, and an upper pestle and a lower pestle are vertically slid above and below each mortar. Rotating powder compression that holds the powder as it is possible and compresses the powder filled in the die by passing the upper and lower punches with the tip of the punch inserted in the die between the upper roll and the lower roll. In a molding machine, a support shaft supporting a roll is supported by first, second, and third bearings, and the roll is rotatably mounted on an eccentric portion of the support shaft located between the first and second bearings. At the same time, a worm wheel for transmitting the rotation of the support shaft to a shock absorber is attached to a portion located between the second and third bearings, and the rotary powder compression molding machine is characterized.