JP4759417B2 - Rotary powder compression molding equipment - Google Patents

Description

  The present invention relates to a rotary powder compression molding apparatus for producing a powder compression molded product such as a tablet by compressing powder.

Conventionally, the weight of a powder compression molding product to be molded is detected by detecting the molding pressure applied to the lower compression roll at the time of compression molding with a load cell and adjusting the height of the weight adjustment track by feedback control based on the detected pressure. In addition to the weight control to keep the pressure constant, when the molding pressure applied to the upper compression roll exceeds the upper limit during compression molding, the coil spring that biases the upper compression roll is compressed to buffer the pressure. A powder compression molding apparatus is known (for example, see Patent Document 1).
Japanese Patent No. 2941226 (paragraphs 0085 to 0099, 0118 to 0120, FIGS. 1 to 4)

  The maximum value of the molding pressure of a compression molded product molded by a rotary powder compression molding apparatus for producing tablets or the like is generally about 10000 kgf (98.0 kN). For example, when a load cell that can withstand a molding pressure of 10,000 kgf is used to detect the molding pressure of a compression molded product molded in a low pressure region of 2500 kgf (24.5 kN) or less, the output voltage from the load cell is It is known to be low and unstable.

  For this reason, a load cell incorporated in the rotary powder compression molding apparatus is selected and used having a resolution capable of withstanding the pressure in the target molding region and outputting a stable output. For example, in a rotary powder compression molding apparatus that performs compression molding in a low pressure region of 2500 kgf (24.5 kN) or less, a load cell having a resolution suitable for the low pressure region is used, and 2500 kgf (24.5 kN) to 10,000 kgf (98. In a rotary powder compression apparatus that performs compression molding in a high pressure region up to 0 kN), a load cell having a resolution suitable for the high pressure region is used.

  It is also known that the load cell has a higher compressive strength and a higher load cell having a higher target molding pressure, and a lower load cell having a lower target molding pressure. Therefore, in a rotary powder compression molding apparatus incorporating a load cell having a low pressure resistance, if the high pressure molding is performed, the load cell will be damaged. Conversely, a rotary powder compression molding apparatus incorporating a load cell having a high pressure resistance. Thus, when low-pressure molding is performed, proper weight control may be difficult due to an output failure in which the output voltage from the load cell becomes unstable.

  Under these circumstances, in conventional rotary powder compression molding apparatuses such as the rotary powder compression molding apparatus described in Patent Document 1, high-pressure and low-pressure load cells and springs for energizing them are prepared in advance. It is considered that this can be dealt with by exchanging in accordance with the molding pressure. Alternatively, a low-pressure or high-pressure dedicated machine suitable for the target molding pressure region may be installed.

  However, with the former measure, it takes a lot of time to replace it, and it also takes time to calibrate the control device according to this replacement. It's hard to say. In the latter measure, two rotary powder compression molding apparatuses for low pressure molding and high pressure molding are required, so that the equipment burden is large.

  An object of the present invention is a rotary powder compression molding apparatus that can perform compression molding at a molding pressure ranging from high pressure to low pressure without causing breakage of the load cell or poor output, less labor in operation, and can reduce the equipment burden. Is to provide.

  The present invention inserts the tip portion of the scissors that can move up and down into the mortar provided on the rotating disk, and narrows the tip spacing of the top and bottom scissors by passing these scissors between the top and bottom compression rolls, It is premised on a rotary powder compression molding apparatus for compressing and molding the powder supplied into the die.

  In order to solve the problems, the present invention provides a high-pressure load cell that detects a molding pressure applied during powder compression molding from one of the upper and lower compression rolls, a high-pressure spring receiver that supports the load cell, and the spring. A transmission shaft having one end connected to the receiver and extending in a direction in which a molding pressure is applied to the high pressure load cell, and a low pressure that is disposed in contact with the other end of the transmission shaft and detects a molding pressure lower than the high pressure load cell. Between the high pressure biasing position and the high pressure biasing release position along the direction of approaching and separating from the high pressure spring receiver between the low pressure load cell and the high pressure spring receiver. The high pressure load screw is disposed between the high pressure adjustment screw and the high pressure adjustment screw and the high pressure spring receiver, and the high pressure adjustment screw is disposed at the high pressure biasing position. A high pressure spring that releases the bias of the high pressure load cell in a state where the high pressure adjustment screw is disposed at the high pressure bias release position, and a low pressure spring receiver on which the low pressure load cell is supported A low-pressure adjusting screw movably disposed between a low-pressure urging position and a low-pressure urging release position along a direction approaching and separating from the low-pressure spring receiver, and the low-pressure adjusting screw and the low-pressure spring. The low pressure load cell is biased with a biasing force that is smaller than the biasing force of the high pressure spring in a state where the low pressure adjustment screw is disposed at the low pressure biasing position. A low-pressure spring for releasing the bias of the low-pressure load cell in a state where the low-pressure adjusting screw is disposed at the release position.

  In the present invention, when powder compression molding is performed in a high pressure molding pressure region, the high pressure spring is contracted by placing the high pressure adjusting screw at the high pressure biasing position, and the high pressure load cell is biased by this spring. On the other hand, the low pressure adjusting screw is placed in the low pressure bias release position to make the low pressure spring free. Thereby, the molding pressure at the time of high pressure molding is applied to the high pressure load cell, and the molding pressure can be detected by this high pressure load cell. When the excessive molding pressure on the high pressure side exceeding the urging force of the high pressure spring is buffered by the compression deformation of the high pressure spring, the low pressure load cell can escape freely even though the transmission shaft pushes the low pressure load cell. Therefore, excessive molding pressure can be prevented from being applied to the low pressure load cell.

  In the present invention, when powder compression molding is performed in the low pressure molding pressure region, the low pressure spring is contracted by placing the low pressure adjusting screw at the low pressure biasing position, and the low pressure load cell is attached to the spring. The high pressure adjustment screw is placed at the high pressure bias release position to make the high pressure spring free. As a result, the molding pressure in the low-pressure molding is applied to the low-pressure load cell via the high-pressure load cell, the high-pressure spring receiver, and the transmission shaft that have strength to withstand high-pressure molding. Can be detected. When a low pressure side excessive molding pressure exceeding the biasing force of the low pressure spring acts on the low pressure load cell, the low pressure coil spring can be compressed and deformed to be buffered.

  As described above, the high-pressure load cell and the low-pressure load cell are properly used according to the molding pressure, so that the high-pressure load cell, the high-pressure coil spring corresponding thereto, the low-pressure load cell and the low-pressure coil spring corresponding thereto are used as replacement parts. These can be used easily and quickly compared to the case where they are prepared and replaced each time the molding pressure is changed. In addition, compression molding from low pressure to high pressure can be performed with a single compression molding apparatus without requiring dedicated machines for high pressure and low pressure, and the equipment burden can be reduced accordingly. At the same time, the low-pressure load cell is not damaged at the molding pressure in the case of high-pressure molding. Furthermore, in the case of low pressure molding, the molding pressure is detected not by the high pressure load cell but by the low pressure load cell, so that no output failure occurs as in the case of detecting the low pressure molding pressure by the high pressure load cell.

  Since the present invention is a single rotary powder compression molding apparatus that switches between a high-pressure load cell and a low-pressure load cell according to the molding pressure, the pressure cell ranges from high pressure to low pressure without causing damage to the load cell or poor output. It is possible to perform compression molding at the molding pressure, reduce labor and reduce the equipment burden.

  An embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a rotary powder compression molding apparatus, for example, a rotary tableting apparatus, includes a rotary tableting machine 10 as a rotary powder compression molding machine and a control panel (not shown).

  The rotary tableting machine 10 includes a rotary disc 11 having a circular shape in a plan view, and a plurality of mortars 12 having a mortar hole penetrating in the axial direction in the central portion are surrounded by a peripheral portion of the mortar mounting portion of the rotary disc 11. Installed side by side at regular intervals in the direction. The rotary tableting machine 10 includes a powder feeder 13. The lower surface opening of the powder feeder 13 is in contact with the upper surface of the rotating disk 11. Powder that is a raw material to be compression-molded is supplied to the powder feeder 13 from a raw material hopper 14 disposed thereabove. The powder fluidized in the powder supplier 13 is supplied to the die 12 when the die 12 passes through the lower surface opening of the powder supplier 13 as the turntable 11 rotates.

  The rotary tableting machine 10 includes an upper punch 15 and a lower punch 16 corresponding to each die 12. The upper rod 15 and the lower rod 16 penetrate through a rod guide hole provided in a rod mounting portion (not shown) of the turntable 11 so as to be slidable in the vertical direction. The upper end portion (tip portion) of the lower punch 16 is slidably inserted into the mortar hole of the corresponding mortar 12 to form the bottom of the mortar hole. The lower end portion (tip portion) of the upper punch 15 is inserted into and removed from the corresponding mortar hole of the mortar 12 from above. The rotary tableting machine 10 includes an upper cam (not shown) having an upper guideway for moving each upper punch 15 up and down, and various lower guide guide tracks for moving each lower punch 16 up and down. I have. Of the lower guide guide track on which the lower end of the lower punch 16 slides, the weight adjusting track 17 disposed at the powder supply position, and the push-up track that pushes a compression molded product such as a compressed tablet onto the die 12. Only 18 is shown in FIG. The upper rod guide track and the lower rod guide track allow the upper rod 15 and the lower rod 16 to move in the axial direction necessary for compression molding.

  The weight adjusting track 17 is supported by a track lifting mechanism 19. The track elevating mechanism 19 includes an elevating drive motor 20, an elevating shaft 21, a gear 22, and a drive gear 23. The elevating drive motor 20 is composed of a servo motor, for example, and a drive gear 23 is fixed to the output shaft thereof. A weight adjusting track 17 is fixed to an upper end portion of a lifting shaft 21 that is lifted and lowered along a guide (not shown). A gear 22 is screwed into a screw portion formed at the lower part of the lifting shaft 21. The gear 22 is meshed with the drive gear 23. For this reason, as the elevating drive motor 20 is rotated forward or backward, the elevating shaft 21 and the weight adjusting track 17 are moved up and down.

  The lower rod guide track includes a lowering track (not shown) arranged immediately before the weight adjusting track 17. When the lower iron 16 is lowered along the lowering trajectory, the powder in the powder feeder 13 is sucked into the mortar hole and filled, and immediately after the filling, the lower iron 16 moves up the inclined surface 17a of the weight adjusting orbit 17. By sliding up, surplus powder is discharged into the powder feeder 13 from the mortar hole, and while the lower punch 16 slides on the horizontal weighing surface 17b of the weight adjusting track 17 after the discharge, the mortar 16 slides. When the upper end of the hole is rubbed by the rear wall 13a of the powder feeder 13, the amount of powder supplied to the die 12 is weighed. Therefore, by changing the height position of the weight adjusting track 17 by the track lifting mechanism 19, the amount of powder supplied into the die 12 is changed, and the weight of a compression molded product such as a tablet to be manufactured is changed accordingly. .

  The rotary tableting machine 10 includes an upper compression roll 24 and a lower compression roll 25. The upper compression roll 24 is disposed above the turntable 11 at the compression molding position, and the lower compression roll 25 is disposed below the turntable 11 at the compression molding position. The upper compression roll 24 and the lower compression roll 25 move the upper collar 15 and the lower collar 16 that pass between them in the axial direction so that the tip portions approach each other. Thereby, the tip space | interval of the upper punch 15 and the lower punch 16 is narrowed, and the powder in the die 12 is compression-molded.

  The compression-molded molded product P is pushed onto the upper surface of the die 12 as the lower punch 16 slides on the push-up track 18. The rotary tableting machine 10 includes a scraper 26. The scraper 26 is arranged at a molded product take-out position from which the compression molded product P is extruded. The molded product P pushed out onto the upper surface of the die 12 is taken out of the rotating disk 11 by the scraper 26 and guided to a predetermined position by a chute.

  As shown in FIGS. 2 and 3, a roll fixing bracket 2 is fixed to the upper frame 1 of the apparatus frame included in the rotary tableting machine 10. The roll fixing bracket 2 has a roll shaft 3 (see FIG. 1) extending in a horizontal direction (a direction perpendicular to the paper on which FIG. 2 and FIG. 3 are drawn) and is not movable in the axial direction and can be rotated around the axis. It is supported. The roll shaft 3 has a non-eccentric shaft portion (not shown), an eccentric shaft portion (not shown), and a non-circular lever mounting shaft portion 3a arranged so as to be aligned in the axial direction.

  The shaft center A of the eccentric shaft portion is eccentric with respect to the shaft center B of the roll shaft 3, and this amount of eccentricity is indicated by a symbol E in FIG. An upper compression roll 24 is rotatably supported on the outer periphery of the eccentric shaft portion via a bearing (not shown). The shaft centers of the non-eccentric shaft portion and the lever mounting shaft portion 3a are the same as the shaft center B. One end portion of the buffer lever 4 is rotatably fitted and attached to the outer periphery of the non-eccentric shaft portion. An L-shaped adjustment lever 5 is fitted and attached to the lever attachment shaft portion 3a, and both ends of the adjustment lever 5 are fixed to the roll fixing bracket 2 using bolts 6, respectively. These bolts 6 are loosened and the roll shaft 3 is rotated about the axis center B via the adjustment lever 5 to change the relative position between the eccentric shaft portion of the roll shaft 3 and the upper compression roll 24. Thus, adjustment to change the height position of the upper compression roll 24 is possible. 2 and 3, reference numeral 2a indicates an arc-shaped escape hole for escaping the bolt 6, and reference numeral 2b indicates an eccentricity scale.

  In FIG. 2 and FIG. 3, reference numeral 7 denotes a spring receiving plate that is positioned directly below the buffer lever 4 and is fixed to the upper frame 1. A stopper pin 8 is attached to the spring receiving plate 7 so as to penetrate the spring receiving plate 7 upward. A coil spring 9 is sandwiched between the stopper pin 8 and the free end of the buffer lever 4. When the upper flange 15 is not in contact with the upper compression roll 24, the coil spring 9 biases the buffer lever 4 upward so that the buffer lever 4 does not rotate downward about the non-eccentric shaft portion by its own weight or the like. is doing. A pressure member 4 a that is harder than the buffer lever 4 is fixed to the upper surface of the free end of the buffer lever 4.

  One of the upper compression roll 24 and the lower compression roll 25, for example, on the upper compression roll 24 side, is provided with a pressure buffering device 31 that detects molding pressure and buffers excessive molding pressure. As shown in FIGS. 2 and 3, the pressure buffer 31 is formed by incorporating a high pressure side pressure buffer mechanism 31 a and a low pressure side pressure buffer mechanism 31 b so as to be aligned in series in the axial direction of the mechanism holder 32. . The high-pressure side pressure buffer mechanism 31a includes a part of the mechanism holder 32, a high-pressure load cell 41, a high-pressure spring receiver 42, a transmission shaft 43, a high-pressure adjusting screw 45, a high-pressure spring, for example, a high-pressure coil spring 46. And. The low pressure side pressure buffer mechanism 31 b includes another part of the mechanism holder 32, a low pressure load cell 44, a low pressure spring receiver 47, a low pressure adjustment screw 48, and a low pressure spring, for example, a low pressure coil spring 49. ing.

  The mechanism holder 32 is formed by connecting the first holder member 33 to the fourth holder member 36 and the stopper member 37 to each other.

  The first holder member 33 has a cylindrical shape with both ends opened, and is fixed to the upper frame 1 through the upper frame 1 in the vertical direction. A thread groove 33 a is formed in the upper part of the inner peripheral surface of the first holder member 33.

  The second holder member 34 has a short cylindrical shape with both ends opened. The second holder member 34 forms a lower end portion of the mechanism holder 32 and is connected to the lower end of the first holder member 33. The second holder member 34 is disposed directly above the free end of the buffer lever 4. The inner diameter of the second holder member 34 is smaller than the inner diameter of the first holder member 33. Thus, the end of the second holder member 34 on the first holder member 33 side functions as a stopper stopper 34 a that protrudes in a stepped manner with respect to the inner peripheral surface of the first holder member 33.

  The third holder member 35 is connected to the upper end of the first holder member 33 and protrudes above the upper frame 1. The third holder member 35 has a cylindrical shape with both ends opened, and an adjustment port 35a and a relief hole 35b are provided on the peripheral wall thereof. The inner diameter of the lower portion of the third holder member 35 is the same as or larger than the portion of the first holder member 33 where the thread groove 33a is provided. The stopper part 35c which consists of is provided.

  The fourth holder member 36 also has a cylindrical shape with both ends opened, and the fourth holder member 36 is connected to the upper end of the third holder member 35. The inner diameter of the fourth holder member 36 is larger than the diameter of the upper end opening of the third holder member 35, and a thread groove 36 a is formed in the upper part of the inner peripheral surface of the fourth holder member 36.

  The stopper member 37 is composed of an L-shaped bracket. The stopper member 37 is connected to the upper end portion of the fourth holder member 36, and the spaced apart portions of the stopper portion 37a of the stopper member 37 and the upper end portion of the fourth holder member 36 are used as an adjustment space. It has become.

  The high-pressure load cell 41 detects a high molding pressure when compression molding is performed using the rotary tableting device of the present invention in a high-pressure region. The high pressure region set in this case is, for example, in the range of 2500 to 10000 kgf (24.5 kN to 98 kN).

  The high pressure load cell 41 is fixed to a high pressure load cell mounting base 50, and the mounting base 50 is fixed to a high pressure spring receiver 42. Therefore, the high pressure load cell 41 is supported by the high pressure spring receiver 42. The high-pressure spring receiver 42 and the high-pressure load cell mounting base 50 can be made integrally. The high-pressure spring receiver 42 is disposed so as to penetrate the central portion of the second holder member 34 in the axial direction, and is prevented from rotating with respect to the second holder member 34 by a sliding key 51. The high-pressure spring receiver 42 is movable in the axial direction of the mechanism holder 32 with the inner peripheral surface of the first holder member 33 and the lower inner peripheral surface of the second holder member 34 as sliding guide surfaces. The high-pressure spring receiver 42 is restricted so that the step on the upper peripheral surface thereof moves further downward, that is, in the direction of the buffer lever 4 so as not to come out of the mechanism holder 32 from the position where it comes into contact with the stopper 34a. The pressure receiving protrusion 41a and the pressure member 4a included in the high pressure load cell 41 are always held in contact with each other.

  The transmission shaft 43 is made of a hard member such as a metal that transmits the molding pressure received by the high-pressure load cell 41 and extends in a direction in which the molding pressure is applied to the high-pressure load cell 41. The transmission shaft 43 is formed of a shaft main body 43a and an adjustment member 43b.

  The lower end portion (one end portion) of the shaft main body 43a is connected to the high pressure spring receiver 42, and the upper end portion (other end portion) of the shaft main body 43a is disposed in the third holder member 35 so as to face the adjustment port 35a. ing. A scale 43c is engraved on the outer peripheral surface of the other end of the shaft main body 43a.

  The adjustment member 43b is attached to the other end portion of the shaft main body 43a so as to be movable in the axial direction, and finely adjusts the length of the transmission shaft 43 by the movement. As the adjustment member 43b, for example, a bolt screwed to the other end of the shaft main body 43a so as to be able to advance and retreat can be suitably used. The adjustment member 43b is arbitrarily rotated from the adjustment port 35a.

  The low-pressure load cell 44 detects a low-pressure molding pressure when compression molding is performed using the rotary tableting device of the present invention in a low-pressure region. The low pressure region set in this case is, for example, a range of 2500 kgf (24.5 kN) or less.

  The low pressure load cell 44 is fixed to a low pressure load cell mounting base 52, and the mounting base 52 is fixed to a low pressure spring receiver 47. Therefore, the low pressure load cell 44 is supported by the low pressure spring receiver 47. The low-pressure spring receiver 47 and the low-pressure load cell mounting base 52 can be integrally formed. The low-pressure spring receiver 47 is disposed so as to penetrate the lower portion in the fourth holder member 36 in the axial direction, and is prevented from rotating with respect to the fourth holder member 36 by a slide key 53. The low-pressure spring receiver 47 is movable in the axial direction of the mechanism holder 32 with the upper opening of the third holder member 35 and the lower inner peripheral surface of the fourth holder member 36 as sliding guide surfaces. The low-pressure spring receiver 47 is restricted so that the step on the peripheral surface of the lower end portion is not moved further downward, that is, in the direction of the buffer lever 4 from the position where it contacts the upper opening edge 35a of the third holder member 35.

  The low-pressure load cell 44 is disposed on the upper part of the third holder member 35, and the output extraction portion 44b is passed through the escape hole 35b. The other end of the transmission shaft 43, that is, the adjustment member 43b is always held in contact with the pressure receiving protrusion 44a of the low pressure load cell 44. This abutting and holding is performed by adjusting the height position of the adjusting member 43b.

  The high pressure adjusting screw 45 is disposed between the low pressure load cell 44 and the high pressure spring receiver 42. Specifically, by adjusting the male thread portion formed on the outer peripheral surface of the high-pressure adjusting screw 45 to the screw groove 33a of the first holder member 33, the high-pressure adjustment is performed across the first holder member 33 and the second holder member 34. A screw 45 is built in the mechanism holder 32. A transmission shaft 43 passes through the center of the high-pressure adjusting screw 45. 2 and 3, reference numeral 54 denotes a sliding bearing that is held by the high-pressure adjusting screw 45 and that can slide the transmission shaft 43.

  The high-pressure adjusting screw 45 has a plurality of operation holes (only two shown) 45a in the upper part thereof. A tool (not shown) is inserted into and removed from the operation hole 45a through the adjustment port 35a, and the high-pressure adjustment screw 45 is rotated through the inserted tool. Accordingly, the high-pressure adjusting screw 45 is moved and adjusted across the high-pressure urging position and the high-pressure urging release position along a direction approaching and separating from the high-pressure spring receiver 42.

  FIG. 2 shows a state in which the high-pressure adjusting screw 45 is disposed at the high-pressure biasing position. The high-pressure biasing position can be arbitrarily set by aligning the upper end surface of the high-pressure adjusting screw 45 with the scale 43c within the range of the scale 43c. FIG. 3 shows a state in which the high-pressure adjusting screw 45 is disposed at the high-pressure bias release position. The arrangement of the high-pressure adjustment screw 45 at the high-pressure bias release position is defined by bringing the upper end surface of the adjustment screw 45 into contact with the stopper portion 35c.

  The high-pressure coil spring 46 is disposed between the high-pressure adjusting screw 45 and the high-pressure spring receiver 42. As shown in FIG. 2, in a state where the high pressure adjustment screw 45 is disposed at the high pressure biasing position, the high pressure coil spring 46 is sandwiched between the high pressure adjustment screw 45 and the high pressure spring receiver 42. . As a result, the high-pressure load cell 41 is biased toward the buffer lever 4 by the spring force of the high-pressure coil spring 46. A pressure member 4 a is held in contact with the pressure receiving protrusion 41 a of the high pressure load cell 41. In this state, when a high-pressure forming pressure exceeding the spring force (biasing force) of the high-pressure coil spring 46 is applied to the high-pressure load cell 41, the high-pressure coil spring 46 is contracted so that the excessive forming pressure can be buffered. It has become.

  As shown in FIG. 3, when the high-pressure adjusting screw 45 is disposed at the high-pressure bias release position, the high-pressure adjusting screw 45 is disposed away from the high-pressure coil spring 46, and the high-pressure coil spring 46 is Become free. Therefore, in this state, the bias of the high-pressure load cell 41 by the high-pressure adjusting screw 45 is released.

  The low pressure adjusting screw 48 is disposed between the stopper portion 37 a of the stopper member 37 and the low pressure spring receiver 47. Specifically, the male screw portion formed on the outer peripheral surface of the low pressure adjusting screw 48 is screwed into the screw groove 36 a of the fourth holder member 36, so that the mechanism holder 32 is low pressure across the fourth holder member 36 and the stopper member 37. Adjustment screw 48 is incorporated. A hollow shaft 55 passes through the center of the low-pressure adjusting screw 48. The hollow shaft 55 is fixed to the low-pressure spring receiver 47 by a screw shaft 56 that penetrates the hollow shaft 55. The free end portion of the hollow shaft 55 passes through the stopper portion 37a and is supported by the stopper portion 37a. A scale 55 a is engraved on the outer periphery of the upper portion of the hollow shaft 55. 2 and 3, reference numeral 57 indicates a sliding bearing that is held by the low-pressure adjusting screw 48 and that can slide the hollow shaft 55.

  The low-pressure adjusting screw 48 has a plurality of operation holes (only two shown) 48a in the upper part thereof. A tool (not shown) is inserted into and removed from the operation hole 48a through the adjustment space between the stopper portion 37a and the upper end portion of the fourth holder member 36, and the low-pressure adjustment screw 48 is rotated through the inserted tool. Operated. Accordingly, the low-pressure adjusting screw 48 is moved and adjusted across the low-pressure urging position and the low-pressure urging release position along the direction approaching and separating from the low-pressure spring receiver 47.

  FIG. 3 shows a state in which the low pressure adjusting screw 48 is disposed at the low pressure biasing position. This low pressure biasing position can be arbitrarily set within the range of the scale 55a by aligning the upper end surface of the low pressure adjusting screw 48 with the scale 55a. FIG. 2 shows a state in which the low pressure adjusting screw 48 is disposed at the low pressure bias release position. The arrangement of the low-pressure adjustment screw 48 at the low-pressure bias release position is defined by bringing the upper end surface of the adjustment screw 48 into contact with the stopper portion 37a.

  The low-pressure coil spring 49 is disposed between the low-pressure adjusting screw 48 and the low-pressure spring receiver 47. The spring force of the low-pressure coil spring 49 is smaller than the spring force of the high-pressure coil spring 46. As shown in FIG. 3, in a state where the low pressure adjusting screw 48 is disposed at the low pressure biasing position, the low pressure coil spring 49 is sandwiched between the low pressure adjusting screw 48 and the low pressure spring receiver 47. . Accordingly, the low pressure load cell 44 is biased toward the buffer lever 4 by the spring force of the low pressure coil spring 49. An adjustment member 43b of the transmission shaft 43 is held in contact with the pressure receiving protrusion 44a of the low pressure load cell 44. In this state, when a low-pressure molding pressure exceeding the spring force (biasing force) of the low-pressure coil spring 49 is applied to the low-pressure load cell 44, the low-pressure coil spring 49 is contracted so that excessive molding pressure can be buffered. It has become.

  As shown in FIG. 2, in a state where the low pressure adjustment screw 48 is disposed at the low pressure bias release position, the low pressure adjustment screw 48 is disposed away from the low pressure coil spring 49, and the low pressure coil spring 48 is Become free. Therefore, in this state, the bias of the low pressure load cell 44 by the low pressure adjusting screw 48 is released.

  The molding pressure in the high pressure region detected by the high pressure load cell 41 is supplied to the high pressure weight control unit 58 (see FIG. 1) in the control panel (not shown), and the low pressure detected by the low pressure load cell 44. The molding pressure in the region is supplied to the low pressure weight control unit 59 (see FIG. 1) in the control panel (not shown). In each of the high pressure weight control unit 58 and the low pressure weight control unit 59, a reference value, that is, an upper limit value and a lower limit value of a target molding pressure are set. The high pressure weight control unit 58 and the low pressure weight control unit 59 determine whether the value of the molding pressure supplied thereto is within the reference value, and the value of the molding pressure supplied to the upper limit value or the lower limit value. In the case of detachment, a weight control signal corresponding to the degree of detachment is given to the elevating drive motor 20 of the track elevating mechanism 19 through a motor drive circuit (not shown) to perform feedback control.

  The rotary tableting device having the above-described configuration is a powder compression molding in the high pressure region without being affected by the low pressure side pressure buffer mechanism 31b, and a low pressure region without being affected by the high pressure side pressure buffer mechanism 31a. Since powder compression molding can be switched, it is possible to perform powder compression molding from low pressure to high pressure while using a single rotary tableting device.

  That is, when powder compression molding is performed in the high pressure region, first, the high pressure side buffer mechanism 31a is set so as to function effectively, and the mechanism 31b is set in a free state so that the low pressure side buffer mechanism 31b does not function. .

  In this case, the high-pressure adjusting screw 45 is moved downward (in the direction of the upper compression roll 24) by the tightening operation and disposed at the high-pressure biasing position, and the upper end surface of the high-pressure adjusting screw 45 is graduated from the transmission shaft 43. Adjust to the desired value of 43c. As a result, the high-pressure coil spring 46 is compressed, and the buffer pressure (set pressure) is set in the range of 2500 to 10,000 kgf (24.5 to 98.0 kN). On the other hand, the low pressure adjusting screw 48 is loosened and moved upward until the upper end of the screw 48 hits the stopper portion 37a of the stopper member 37, and the low pressure adjusting screw 48 is arranged at the low pressure release position. As a result, the low-pressure coil spring 49 is brought into a free state. The above set state is shown in FIG.

  By operating the rotary tableting device from this state, powder compression molding is performed in a high pressure region. In this compression molding, as the upper collar 15 passes through the upper compression roll 24, the molding pressure in the high pressure region acting on the upper compression roll 24 via the upper collar 15 is transferred via the buffer lever 4 to the high pressure load cell 41. Added to. When the molding pressure in the high pressure region is lower than the high pressure side buffer pressure (high pressure side set pressure) determined by the biasing force of the high pressure coil spring 46, a voltage corresponding to the pressure is supplied from the high pressure load cell 41 to the high pressure weight. It is supplied to the control unit 58, and weight control is performed by feedback control under high pressure molding.

  When the molding pressure in the high pressure region becomes higher than the high pressure side buffer pressure (high pressure side set pressure) determined by the urging force of the high pressure coil spring 46, the high pressure region resists the urging force of the high pressure coil spring 46. Since the load cell 41 is moved by being pushed by the buffer lever 4, it is possible to prevent the high-pressure load cell 41 from being damaged by an excessive molding pressure.

  In this case, the low pressure load cell 44 is pushed through the high pressure side buffer mechanism 31a. That is, the high-pressure load cell 41, the high-pressure spring receiver 42, and the transmission shaft 43 move together with the high-pressure load cell 41, so that the low-pressure load cell 44 is pushed. However, since the low-pressure coil spring 49 is in a free state, the low-pressure load cell 44, the low-pressure load cell mounting base 52, the low-pressure spring receiver 47, the hollow shaft 55, and the screw shaft 55 follow the movement of the high-pressure load cell 41. Then move. Therefore, since the excessive molding pressure exceeding the high pressure region is not applied to the low pressure load cell 44 having a lower strength than the high pressure load cell 41, the low pressure load cell 44 and the like are not damaged.

  When performing powder compression molding in the low pressure region, first, the low pressure side buffer mechanism 31b is set to function effectively, and the mechanism 31a is set in a free state so that the high pressure side buffer mechanism 31a does not function. .

  In this case, the low-pressure adjusting screw 48 is moved downward (in the direction of the upper compression roll 24) by the tightening operation and disposed at the low-pressure biasing position, and the upper end surface of the low-pressure adjusting screw 48 is graduated from the hollow shaft 55. Adjust to the desired value of 55a. As a result, the low-pressure coil spring 49 is compressed, and the buffer pressure (set pressure) is set within a range of 2500 kgf (24.5 kN) or less. On the other hand, the high pressure adjusting screw 45 is loosened and moved upward (in the direction of the low pressure load cell 44) until the upper end of the screw 45 comes into contact with the stopper portion 35c of the third holder member 35, thereby releasing the high pressure adjusting screw 45 from the high pressure. Place in position. Thereby, the high-pressure coil spring 49 is brought into a free state. The above set state is shown in FIG.

  By operating the rotary tableting device from this state, powder compression molding is performed in the low pressure region. In this compression molding, as the upper collar 15 passes through the upper compression roll 24, the molding pressure in the low pressure region acting on the upper compression roll 24 via the upper collar 15 is transferred via the buffer lever 4 to the high pressure load cell 41. Added to. In this case, since the high-pressure coil spring 46 is in a free state, the high-pressure load cell 41 and the high-pressure load cell mounting base 50, the high-pressure spring receiver 42, and the transmission shaft 43 are adjusted by the adjusting member 43 b of the transmission shaft 43. The low pressure load cell 44 is pushed. At this time, the high pressure load cell 41 having higher strength than the low pressure load cell 44 can be treated as a rigid body. Since the low pressure side molding pressure acting on the high pressure load cell 41 is lower than the high pressure side molding pressure, the high pressure load cell 41 is not damaged by the low pressure side molding pressure.

  Therefore, when the molding pressure in the low pressure region is lower than the low pressure side buffer pressure (low pressure side set pressure) determined by the biasing force of the low pressure coil spring 49, the voltage corresponding to the pressure is reduced from the low pressure load cell 44. The weight control unit 59 is supplied to the weight control unit 59 to perform weight control by feedback control under low pressure molding.

  When the molding pressure in the low pressure region becomes higher than the low pressure side buffer pressure (low pressure side set pressure) determined by the biasing force of the low pressure coil spring 49, the low pressure region resists the biasing force of the low pressure coil spring 49. Since the load cell 44 is pushed and moved by the transmission shaft 43, the low pressure load cell 44 can be prevented from being damaged by an excessive molding pressure.

  As described above, the rotary tableting machine 10 uses the high-pressure load cell 41 and the low-pressure load cell 44 in accordance with the molding pressure so that one of them is enabled and the other is disabled. 41 and a high-pressure coil spring corresponding thereto, a low-pressure load cell 44 and a low-pressure coil spring corresponding thereto are prepared as replacement parts, and these are compared with the case where they are replaced each time the molding pressure is changed. This can be used easily and quickly. In addition, compression molding from low pressure to high pressure can be performed with a single compression molding apparatus without requiring dedicated machines for high pressure and low pressure, and the equipment burden can be reduced accordingly.

  The present invention is not limited to the one embodiment. For example, the pressure buffer device 31 may be arranged along an oblique direction or a horizontal direction instead of the vertical direction. Further, the pressure buffer device 31 may be disposed on the lower compression roll 25 side. However, when the pressure buffer device 31 is disposed so as to extend below the lower compression roll 25, for example, when the pressure buffer device 31 is disposed on the upper compression roll 24 side as in the embodiment, the pressure buffer device 31 is disposed. It is preferable in that the apparatus frame does not need to be raised correspondingly to the arrangement height.

The figure which expand | deploys and shows schematically the structure of the rotary tableting machine which concerns on one Embodiment of this invention. Sectional drawing shown in the state which set the pressure buffer apparatus with which the rotary tableting machine of FIG. 1 was equipped so that it might be suitable for high pressure molding. Sectional drawing shown in the state which set the pressure buffer apparatus with which the rotary tableting machine of FIG. 1 was equipped so that it might be suitable for low pressure molding.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Roll axis | shaft, 4 ... Buffer lever, 10 ... Rotary type tableting machine (rotary powder compression molding machine), 11 ... Rotary disk, 12 ... Mortar, 15 ... Upper punch, 16 ... Lower punch, 19 ... Orbit raising / lowering mechanism 24 ... Upper compression roll, 26 ... Lower compression roll, 31 ... Pressure buffer, 41 ... High pressure load cell, 42 ... High pressure spring receiver, 43 ... Transmission shaft, 43a ... Shaft body, 43b ... Adjustment member, 44 ... Low pressure Load cell, 45 ... high pressure adjustment screw, 46 ... high pressure coil spring (high pressure spring), 47 ... low pressure spring receiver, 48 ... low pressure adjustment screw, 49 ... low pressure coil spring (low pressure spring)

Claims (1)

Insert the tip part of the scissors that can move up and down into the mortar provided on the rotating disk, and pass these scissors between the upper and lower compression rolls to narrow the tip spacing of the upper and lower scissors, In the rotary powder compression molding apparatus that compresses and molds the supplied powder,
A high-pressure load cell that detects a molding pressure applied during compression molding of the powder from one of the upper and lower compression rolls;
A high-pressure spring receiver on which the load cell is supported;
A transmission shaft having one end connected to the spring receiver and extending in a direction in which a molding pressure is applied to the high-pressure load cell;
A low pressure load cell that is disposed in contact with the other end of the transmission shaft and detects a molding pressure lower than the high pressure load cell;
A high-pressure adjusting screw disposed between the low-pressure load cell and the high-pressure spring receiver so as to be movable between a high-pressure biasing position and a high-pressure biasing release position in a direction approaching and separating from the high-pressure spring receiver. When,
The high pressure load cell is disposed between the high pressure adjustment screw and the high pressure spring receiver, and the high pressure load cell is biased in the state where the high pressure adjustment screw is disposed at the high pressure biasing position. A high-pressure spring for releasing the bias of the high-pressure load cell in a state where the high-pressure adjusting screw is disposed;
A low-pressure spring receiver on which the low-pressure load cell is supported;
A low-pressure adjusting screw that is movably disposed between a low-pressure biasing position and a low-pressure biasing release position along a direction approaching and separating from the low-pressure spring receiver;
The low pressure adjusting screw is arranged between the low pressure adjusting spring and the low pressure spring receiver, and the low pressure adjusting screw is biased by a biasing force smaller than that of the high pressure spring in the state where the low pressure adjusting screw is disposed at the low pressure biasing position. A low pressure spring that biases the load cell and releases the bias of the low pressure load cell in a state where the low pressure adjustment screw is disposed at the low pressure bias release position;
A rotary powder compression molding apparatus.

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