JPH0890296A - Rotary press for compression molding powder - Google Patents

Abstract

PURPOSE: To improve the malfunction of a worm in a shock absorber. CONSTITUTION: In a rotary press for compression molding powder, an eccentric bearing shaft 93 of at least either an upper roll 81 or a lower roll 91 is provided with a worm wheel 98 for transmitting the turning of the eccentric bearing shaft 93 to a shock absorber 110. The shock absorber 110 is equipped with a gear part which is provided turnably engaged with the worm wheel 98; a shaft 113 movable back and forth which contains a cavity 112 inside and which is slidable in the axial direction in accordance with the turning of the worm wheel 98; a pressing means which is provided inside the cavity 112 of the shaft 113 movable back and forth and by which the shaft 113 is pressed in the direction of one end of the shaft; and an adjusting means for adjusting the pressing force of the pressing means.

Description

Detailed Description of the Invention

[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.
Moreover, the present invention relates to a shock absorber that absorbs an abnormal load generated in 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 addition, 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. In this case, the worm wheel is mounted so that it can slide in the axial direction of the support shaft.

[0005]

It has been pointed out that, in this type of rotary powder compression molding machine, severe wear also occurs at the meshing portion between the worm wheel and the worm. Also, when the worm wheel rotates due to an abnormal reaction force acting on the roll, that is, an impact load, the worm is normally moved in the axial direction to absorb the impact load, but in some cases, the worm can be rotated. In addition, a load may act directly on the rotating shaft that is slidably supported. That is, when the worm wheel rotates due to an impact load, a force that pushes the rotary shaft in the direction opposite to the worm wheel is generated, which may cause the rotary shaft to bend. As described above, when the rotary shaft bends, it becomes difficult for the worm to slide, the reaction force cannot be absorbed, and in the worst case, the shock absorber may be destroyed.

The present invention has been made on the basis of the above-described investigation results, and it is an object of the present invention to provide a rotary powder compression molding machine capable of effectively eliminating the above-mentioned problems with a simple structure. .

[0007]

The present invention takes the following means in order to achieve such an object. That is, in the rotary powder compression molding machine according to the present invention, a rotary disk is disposed 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 the dies are provided above and below each mortar. Keep the upper and lower punches slidable vertically and compress 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 rotary powder compression molding machine configured to perform molding, a worm wheel for transmitting rotation of the eccentric support shaft to a shock absorber is provided on at least one eccentric support shaft of an upper roll and a lower roll, A device includes a gear portion that is rotatably provided by meshing with the worm wheel, has a cavity inside, and is provided with an advancing / retreating shaft that is slidably provided in the axial direction according to the rotation of the worm wheel. In the cavity of the advancing / retreating axis Biasing means for vignetting urging the forward and backward axis in one axial end direction, characterized by comprising an adjustment means for adjusting the biasing force of the biasing means.

As a shock absorber in the present invention, typically, a forward / backward shaft has a hollow worm forming a gear portion, and a first shaft body fixed to one end of the worm and closing the one end thereof. A second shaft body that is internally provided in the worm and that is slidably supported so as to project from the other end, and biasing means is provided internally in the worm and is provided in the first shaft body. The adjustment means may include a spring that rotatably abuts against the adjustment means, and the adjustment means may include a rod body that can change the stop position of one end of the spring in the axial direction.

[0009]

According to the present invention, since the advancing / retreating shaft having the gear portion meshing with the worm wheel is slidable, even if an impact load acts on the shock absorber, the advancing / retreating shaft itself slides to bend the advancing / retreating shaft. There is no waste. Therefore, the gear portion operates in response to the movement of the worm wheel, the movement of the worm wheel is not hindered, and the impact load is reliably absorbed by the biasing means.

Moreover, since the urging means is provided within the cavity of the advancing / retreating shaft despite urging the advancing / retreating shaft, the shock absorber has the advancing / retreating shaft from either one of the shaft ends. It can be made smaller than the biased one. Moreover, since the urging means is covered with the advancing / retreating shaft, it is possible to prevent the adhesion of powder, the entrapment of foreign matter, etc., and to improve the durability.

[0011]

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.

In this rotary powder compression molding machine 100, a rotary disk 3 is arranged in a frame 1 so as to be horizontally rotatable via a vertical shaft 2, and a plurality of dies 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. Then, with the tips of the upper punch 5 and the lower punch 6 inserted into the die 4, first,
The powder filled in the mortar 4 is compression-molded by passing it between the upper roll 81 for pre-compression and the lower roll 91, and then passing it between the upper roll 82 and lower roll 92 for main compression. You can do it. 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 fixed 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 mortar portion provided between the upper pestle holding portion 32 and the lower pestle holding portion 31 and provided with a plurality of mortar mounting holes for detachably fitting the mortar 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. 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 attached near the upper end of the upright shaft 2, and is guided to the upper rolls 81, 82. At the reaching position, the upper rolls 81 and 82 are guided to a lower position where they enter below. Further, the lower punch 6 is moved up and down by a lowering device 61 provided on the lower side of the turntable 3, and the lower rolls 91, 92 are
After the compression by the above is completed, when the molded product molded by the compression is taken out from the die 4, it is guided to the highest position.

Upper roll 81 and lower roll 9 for preliminary compression
1, and the upper roll 82 and the lower roll 92 for the main compression are respectively paired up and down, and as shown in FIG.
Upper and lower rolls 8 for pre-compression with respect to the rotating direction of the turntable 3.
1, 91, upper and lower rolls for main compression 82, 92 in this order,
For example, they are arranged at an angle of 67 degrees. The pre-compression lower roll 91 has an eccentric portion 96 located between bearings 94 and 95 of an eccentric support shaft (hereinafter, simply referred to as a support shaft) 93.
Is rotatably fitted to the outer circumference of the support shaft 93 by a bearing 94,
It is supported on the lower part of the frame 1 via 95. A worm wheel 98 is fixed to the support shaft 93 of the lower roll 91 with a key 99. Worm wheel 98
Engages with the worm of the shock absorber 110 described later. Although not shown, a worm wheel 98 is fixed to the lower roll 92 for main compression as well as the lower roll 91 for preliminary compression.
Connected to

As shown in FIG. 2, the shock absorber 110 is provided with a worm 111 which is a gear portion which is rotatably engaged with the worm wheel 98 and has a cavity 112 therein.
And an advancing / retreating shaft 113 which is provided so as to be slidable in the axial direction in response to the rotation of the worm wheel 98, and which is provided in the cavity of the advancing / retreating shaft 113 and biases the advancing / retreating shaft 113 toward one axial end direction. Coil spring 120 as biasing means
And a pressing member 130 as an adjusting means for adjusting the urging force of the coil spring 120 and a rod body 131 with a screw.

The advancing / retreating shaft 113 includes a worm 111 having a cavity 112 therein, a first shaft 114 fixed to one end of the worm 111 and closing the one end thereof, and internally provided in the worm 111. The second shaft body 115 is provided so as to project from the other end and slidably supported. That is, the advancing / retreating shaft 113 is disposed inside the worm 111 having gear teeth formed on the outer periphery of the cylindrical body.
11, a second shaft body 115 including a body part 115a having the same length as that of the body part 11 and a shaft support part 115b having a smaller outer diameter protruding from the body part 115a is fixed, and the worm 111 and the second shaft body 115 are integrated. A first shaft body 114 is formed by being fixed to one end by a bolt 116. The first shaft body 114 and the second shaft body 115 are attached to each other by the slide bearing 117.
It is supported so as to be capable of reciprocating in the axial direction and in a direction opposite to the biasing direction of the coil spring 120, that is, capable of advancing and retracting. Then, at the end portion of the second shaft body 115 on the side opposite to the first shaft body 114, the threaded rod body 130 has the second shaft body 115.
It does not interfere with the slide of. 118 is
It is a thrust bearing. The end of the first shaft 114 that is not connected to the worm 111 is connected to a position adjusting device (not shown) as in the conventional case.

The coil spring 120 includes the second shaft 11
5, the end portion on the side of the first shaft 114 is rotatably supported by the thrust bearing 118 in the circumferential direction, and the other end is attached to the threaded rod body 1 via the pressing member 130.
At 31, the movement in the urging direction is prohibited. Although the coil spring 120 in this embodiment is formed by winding a wire having a circular cross section into a cylindrical shape, it may be formed by winding a wire having a rectangular cross section into a cylindrical shape. . A pressing member 130 is attached to the end of the coil spring 120 on the second shaft 115 side, and a rod body 131 with a screw that attaches the pressing member 130 to the frame 1 in the opposite biasing direction. Movement is prohibited.
That is, in the threaded rod body 131, the threaded portion 131a is formed on the large-diameter portion of one end portion thereof.
31a is screwed with the female thread portion of the frame 1 to be mounted, and a mounting hole 131b for mounting a handle on the other end.
Is provided. Therefore, the threaded rod body 131 is
The coil spring 120 can be rotated with respect to the second shaft body 115, and by rotating, the coil spring 120 can be pushed in the direction of the first shaft body 114 against the biasing force thereof. It is configured to adjust the power.

In such a structure, the advancing / retreating shaft 113
Is always connected to the first shaft 114 by the coil spring 120.
Is urged in the direction, for example, the lower roll 9 for precompression.
When an abnormal reaction force acts on 1, the worm wheel 9
When 8 rotates, it moves in the direction of the threaded rod body 131 against the biasing force of the coil spring 120. That is, an abnormal reaction force during tableting causes the lower roll 91 for pre-compression.
When it acts on the eccentric part 9 of the support shaft 93 by this reaction force.
The pre-compression lower roll 91, which is rotatably fitted around the support shaft 6, rotates downward about a support shaft 93, and together with this, the support shaft 93.
Rotates. As a result, the worm wheel 98 fixed to the support shaft 93 rotates in the rotation direction of the support shaft 93, and applies a force in the anti-biasing direction to the worm 111 meshing with the worm wheel 98. Energize.
As a result, the coil spring 120 is compressed and the worm 111 moves against the urging force, and the first shaft body 114 and the second shaft body 114 connected to the worm 111 are fixed.
The shaft 115 moves (shows a state in which it slides in FIG. 3) to cushion an impact load due to an abnormal reaction force. In this case, even if a force due to an impact load acts on the worm wheel 98 in a direction perpendicular to the advancing / retreating shaft 113 (downward in the drawing in FIG. 3), the worm 111 does not have a structure in which it slides with respect to the mounting shaft. Even if such a force acts, the entire advancing / retreating shaft 113 slides in the anti-biasing direction, and effectively exhibits the cushioning function.

Further, in the advancing / retreating shaft 113, the coil spring 120 is attached to the first shaft 114 via the thrust bearing 118 in the second shaft 115, so that the advancing / retreating shaft 113 is rotated. It does not rotate. That is, even if the first shaft body 114 is rotated to adjust the height of the lower roll 91, that is, to adjust the preload, the coil spring 120 maintains the original position without being rotated by the thrust bearing 118. Therefore, even if the height of the lower roll 91 is adjusted, the coil spring 120
It does not affect the urging force of.

In this way, the advancing / retreating shaft 113 slides against the urging force of the coil spring 120 due to the rotation of the worm wheel 98, so the movement of the worm 111 with respect to the worm wheel 98 is not restricted, and a positive impact is ensured. Can absorb the load. Also, advance / retreat axis 1
Coil spring 12 that absorbs impact load inside 13
Since 0 is provided, the coil spring 120 can be compared to a structure in which the advancing / retreating shaft 113 is biased outside the one end thereof.
It is possible to eliminate a space for arranging the shock absorber and to reduce the size of the shock absorber. Moreover, coil spring 1
Since 20 is not exposed to the outside, damage is less likely to occur and durability can be improved.

The structure of each part is not limited to the illustrated embodiment, but in the above embodiment, the slide bearings 117 provided at both ends of the advance / retreat shaft 113 allow the advance / retract shaft 11 to move.
Although 3 slides with the slide bearing 117, for example, a structure may be adopted in which the advancing / retreating shaft 113 is rotatably and rotatably supported by a ball bush, and the advancing / retreating shaft 113 itself advances and retracts with respect to the frame 1.

Various modifications can be made without departing from the spirit of the present invention.

[0025]

As described in detail above, the present invention includes a gear portion that meshes with a worm wheel when an impact load due to an abnormal reaction force generated on a roll acts on a shock absorber. Since the advancing / retreating shaft itself slides, the advancing / retreating shaft does not bend, the movement of the worm wheel is not hindered, and the impact load can be reliably absorbed by the biasing means.

Moreover, since the urging means is provided in the cavity of the advancing / retreating shaft despite urging the advancing / retreating shaft, the shock absorber has the advancing / retreating shaft from either one of the shaft ends. It can be made smaller than the biased one. Moreover, since the urging means is covered with the advancing / retreating shaft, it is possible to prevent the adhesion of powder, the entrapment of foreign matter, etc., and to improve the durability.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing an enlarged main part of the embodiment.

FIG. 3 is a cross-sectional view showing an operating state of a main part of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Vertical shaft 3 ... Rotating plate 4 ... Mortar 5 ... Upper punch 6 ... Lower punch 8 ... Upper roll 9 ... Lower roll 110 ... Shock absorber 111 ... Worm 112 ... Cavity 113 ... Advance shaft 114 ... 1st shaft body 115 ... Second shaft body 120 ... Coil spring 130 ... Pressing member 131 ... Screw rod body

Claims (2)

[Claims] 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 much as possible and compresses the powder filled in the die by passing the upper and lower punches with the tips inserted into the die between the upper roll and the lower roll. In the molding machine, the eccentric support shaft of at least one of the upper roll and the lower roll is provided with a worm wheel for transmitting the rotation of the eccentric support shaft to the shock absorber, and the shock absorber meshes with the worm wheel. Provided with a gear portion rotatably provided therein and having a cavity inside so as to be slidable in the axial direction according to the rotation of the worm wheel, and provided within the cavity of the advance / retreat shaft. With an advancing / retreating axis in one axis end direction Rotary powder compression molding machine, wherein a biasing means, by comprising an adjustment means for adjusting the biasing force of the biasing means. 2. A reciprocating shaft, a hollow worm forming a gear portion, a first shaft body fixed to one end of the worm and closing the one end thereof, and internally provided in the worm, and the other side thereof. A second shaft body projecting from the end and slidably supported, and the urging means includes a spring provided inside the worm and rotatably abutting against the first shaft body. 2. The rotary powder compression molding machine according to claim 1, wherein the adjusting means comprises a rod body capable of changing the stop position of one end portion of the spring in the axial direction.