Powder measuring device, method for confirming or calibrating characteristics of sensor probe

Abstract

To provide a method for confirming or calibrating properties of a sensor probe, without detaching the same from a measuring device for measuring properties of mixed powder.SOLUTION: A method is configured so that, after measuring properties of mixed powder in which two or more kinds of powder are mixed, the mixed powder is sent to an appliance which executes processing of a post-process using the mixed powder. A powder measurement device M comprises: a sensor probe S3 for, for measuring properties of the mixed powder during operation for sending the mixed powder to the appliance, and receiving reflectance which contacts the mixed powder passing the vicinity thereof and reflects, or transmission light which transmits the mixed powder; and a reference sample M23 for, during operation for sending the mixed powder toward the appliance, facing the sensor probe S3 when the mixed powder does not exist in the vicinity of the sensor probe S3 for causing the sensor probe S3 to receive the reflectance which contacts the mixed powder and reflects, or transmission light which transmits the mixed powder, the properties of the reference sample being known already.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a powder measuring device and a sensor probe thereof for measuring the properties of a powder mixture in which two or more types of powder are mixed. [Background technology]

[0002] A rotary powder compression molding machine is well known in which die holes are provided on the table of a rotating plate, and an upper punch and a lower punch are slidably held above and below each die hole, and both the die holes and the punches are rotated horizontally to compress and mold (or tablet) the powder filled in the die holes when the pair of upper and lower punches passes between the upper and lower rolls. This type of powder compression molding machine is widely used in the manufacture of pharmaceutical tablets, food products, electronic components, etc.

[0003] In the past, at pharmaceutical tablet production sites, it was common to create intermediate products for each process, such as granulation, drying, granulation adjustment, and mixing, for the powder that constitutes the tablet, using a batch-type procedure that would ultimately result in compression (tabletting) using a molding machine.

[0004] However, in such a batch method, several scale-up processes are required to move from a small research and development scale molding machine to a large commercial scale molding machine. Then, experiments must be conducted to verify the scale-up at each stage, which increases the opportunities to use raw material powder and incurs huge costs. In addition, the batch method creates waiting times between each process. For example, in order to perform a compression process using a molding machine, it is essential to perform a mixing process to mix the powders prior to the compression process and to supply the powder completed by the mixing process to the molding machine. During that time, the molding machine stops operating and waits. In other words, it is difficult to supply intermediate products in a timely manner. In addition, there is the disadvantage that equipment design is required for each process, which occupies a large space. More specifically, a room is used for each process, and workers need to carry the intermediate products to the room for the next process.

[0005] Therefore, a system was developed that performs the powder mixing and compression processes continuously and supplies the mixed powder directly to the molding machine. With this system, the mixed powder can be replenished to the molding machine at the appropriate time while the powder compression tableting process by the molding machine continues.

[0006] A powder mixing and supplying device that performs a powder mixing process includes a plurality of feeders that each store powder and discharge the stored powder, and supplies the powder discharged by each feeder to a molding machine or other equipment that performs post-processing after mixing the powder. A typical example of a feeder is a fixed-volume feeder that continuously discharges a fixed amount of powder per specified time. A fixed-volume feeder sends out powder that falls from a hopper that stores powder using a screw feeder, table feeder, circle feeder (registered trademark), rotary feeder, etc., and measures the discharge flow rate of the powder discharged by the fixed-volume feeder per unit time using a measuring device, such as a load cell, and feedback-controls a motor that is a driving source of the screw feeder, etc., so that the discharge flow rate converges to a target flow rate.

[0007] The powder mixing and supplying device has a built-in measuring device that uses near-infrared spectroscopy (NIR, or near-infrared absorption spectroscopy) or the like to measure the properties of the powder, particularly the degree of mixing (presence or absence of segregation). The powder measuring device irradiates the powder with light waves (or electromagnetic waves) such as near-infrared light in the process of transferring the mixed powder toward a molding machine or the like, receives the reflected (or scattered) light or transmitted light with a sensor probe, measures the reflection and / or absorption of the light waves by the powder, and performs qualitative and quantitative analysis of the uniformity of the mixed powder and other aspects based on the spectrum. Defective powders whose properties such as uniformity deviate from the normal range are rejected within the powder mixing and supplying device and are not supplied to the molding machine (see, for example, the following patent documents for the above). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2020-168634 A Summary of the Invention [Problem to be solved by the invention]

[0009] When operating a powder mixing and supplying device, it is necessary to constantly check or calibrate the input / output characteristics of the sensor probe, which is an element of the measuring device, i.e., the relationship between the properties of the target powder and the signal output by the sensor probe that measures this.

[0010] The sensor probe facing the mixed powder being transferred is subject to the adhesion of dust or dirt, whether originating from the powder or not, to the sensor probe. The dust introduces noise into the spectrum of the reflected light or transmitted light that should be received by the sensor probe, and thus reduces the S / N ratio of the output signal from the sensor probe.

[0011] Even if this is not the case, the input / output characteristics of the sensor probe may change over time. If the powder mixture supply device continues to operate without noticing the change in the input / output characteristics of the sensor probe, the properties of the mixed powder cannot be accurately grasped, making it difficult to supply high-quality mixed powder to molding machines and other equipment.

[0012] In the conventional system, the operation was stopped once, the sensor probe was removed from the measuring device, the input / output characteristics of the sensor probe were calibrated, and if necessary, cleaning was performed, and the sensor probe was then reattached to the measuring device, and the system was then restarted. In this way, it was time-consuming to detach the sensor probe every time calibration was performed, and the system had to be temporarily stopped every time, which reduced the production efficiency of products using mixed powders.

[0013] The present invention was made in response to the above problems, and has as its intended purpose the ability to check or calibrate the characteristics of a sensor probe at any time without removing it from a measuring device, or to maintain high quality characteristics of the sensor probe while the measuring device is in operation. [Means for solving the problem]

[0014] In the present invention, after measuring the properties of a mixed powder in which two or more powders are mixed, the mixed powder is sent to an apparatus that performs a post-process using the mixed powder, A rotating body having a plurality of moving parts, each of which captures and transports a mixing member during operation of delivering the mixed powder toward the device; During operation of delivering the powder mixture to the device, Captured by each moving part of the rotating body a sensor probe for receiving light reflected from or transmitted through the powder mixture passing nearby the sensor probe in order to measure the properties of the powder mixture; The rotor is provided at a portion that separates a certain moving portion from another moving portion adjacent thereto, A powder measuring device was configured that includes a standard sample with known properties that is arranged so that when the mixed powder is not present in the vicinity of the sensor probe during operation of sending the mixed powder toward the equipment, the standard sample faces the sensor probe and receives the reflected light that hits it or the transmitted light that passes through it.

[0016] In addition, the term "powder" refers to an aggregate of minute solids, and is a concept that includes an aggregate of particles such as so-called granules, and an aggregate of powders smaller than particles. Specific examples of powders include powders containing a main ingredient, as well as excipients, binders, disintegrants, stabilizers, preservatives, etc. Powders that are a mixture of two or more types of powders are also a type of powder referred to in the present invention, and powders containing a main ingredient mixed with lubricants such as magnesium stearate also fall under the category of powders.

[0017] According to the present invention, while continuing to operate the powder mixing supply device and the equipment that performs downstream processing, when the mixed powder does not pass near the sensor probe, a standard sample is measured by the sensor probe, and the input / output characteristics of the sensor probe can be confirmed or calibrated by referring to the output signal of the sensor probe obtained as a result.

[0018] The powder measuring device includes a moving member that moves past the vicinity of the sensor probe, and in particular captures and transports the powder mixture that is delivered to the instrument. Rotating body with multiple moving parts If the above is provided, Rotating body It is preferable that the standard sample is provided at a position facing the sensor probe in the Rotating bodySince the light beam necessarily passes near the sensor probe, the characteristics of the sensor probe can be confirmed or calibrated during the process.

[0019] In addition, Rotating body a cleaning material that comes into contact with the sensor probe and wipes it off is provided at a portion facing the sensor probe; Rotating body Therefore, the dust or dirt adhering to the sensor probe due to the movement of the sensor probe can be cleaned and removed, and the characteristics of the sensor probe can be maintained at a high quality even during the operation of the measuring device.

[0020] Alternatively, a nozzle for ejecting gas to blow off and remove dust or dirt adhering to the sensor probe may be provided. Effect of the Invention

[0021] According to the present invention, the characteristics of a mixed powder can be checked or calibrated at any time without removing the sensor probe from a measuring device that measures the properties of the mixed powder. Also, the characteristics of the sensor probe can be maintained at high quality while the measuring device is in operation. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a side cross-sectional view of a rotary powder compression molding machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a main part of the rotary powder compression molding machine according to the embodiment. [Diagram 3] FIG. 2 is a cylindrical view of the rotary powder compression molding machine according to the embodiment. [Figure 4] FIG. 2 is a side view of a main part of the powder mixing and supplying device of the embodiment. [Diagram 5] FIG. 2 is a side cross-sectional view of a vertical mixer which is an element of the powder mixing and supplying device of the embodiment; [Figure 6] FIG. 2 is an enlarged side cross-sectional view of a main part of the vertical mixer according to the embodiment. [Figure 7] FIG. 4 is a side cross-sectional view showing another example of a vertical mixer. [Figure 8]FIG. 2 is a perspective view of a stirring shaft and a stirring blade (second mixing member) of a horizontal mixer which is an element of the powder mixing and supplying device of the embodiment. [Figure 9] FIG. 2 is a perspective view of a main part of the powder measuring device of the embodiment. [Figure 10] FIG. 2 is a plan view of a main part of the powder measuring device of the embodiment. [Figure 11] FIG. 4 is a perspective view of a case of the powder measuring device of the embodiment. [Figure 12] FIG. 4 is a perspective view of a driver of the powder measuring device of the embodiment. [Figure 13] FIG. 2 is a block diagram of a control system of the powder compression molding system according to the embodiment. [Figure 14] FIG. 2 is an enlarged side cross-sectional view showing a portion of the powder measuring device of the embodiment. [Figure 15] FIG. 2 is an enlarged side cross-sectional view showing a portion of the powder measuring device of the embodiment. [Figure 16] FIG. 2 is an enlarged side cross-sectional view showing a portion of the powder measuring device of the embodiment. [Figure 17] FIG. 2 is an enlarged side cross-sectional view showing a portion of the powder measuring device of the embodiment. [Figure 18] FIG. 2 is an enlarged side cross-sectional view showing a portion of the powder measuring device of the embodiment. [Figure 19] 5 is a graph showing a specific example of a measurement result obtained by the sensor probe of the powder measuring device of the embodiment. [Figure 20] FIG. 13 is a plan view of a main part of a powder measuring device according to a modified example of the embodiment. [Figure 21] FIG. 13 is a plan view of a main part of a powder measuring device according to a modified example of the embodiment. [Figure 22] FIG. 4 is a side cross-sectional view of a supply unit of the powder measuring device of the embodiment. [Figure 23] FIG. 4 is a side cross-sectional view of a supply pipe of the powder mixing supply device of the embodiment. [Figure 24] FIG. 4 is a timing chart showing a pattern of control performed by a control system of the powder compression molding system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An embodiment of the present invention will be described with reference to the drawings. First, an overall outline of a rotary powder compression molding machine (hereinafter referred to as a "molding machine") in this embodiment will be described. As shown in FIG. 1, a vertical shaft 2 serving as a rotating shaft is set up in a frame 1 of the molding machine, and a rotating plate 3 is attached to the upper part of the vertical shaft 2 via a connecting part 21. A worm wheel 7 is attached to the lower end side of the vertical shaft 2. A worm gear 10 meshes with the worm wheel 7. The worm gear 10 is fixed to a gear shaft 9 driven by a motor 8. The driving force output by the motor 8 is transmitted to the gear shaft 9 by a belt 11, and rotates the vertical shaft 2 via the worm gear 10 and the worm wheel 7. Then, as the vertical shaft 2 rotates, the rotating plate 3 and the punches 5 and 6 rotate.

[0024] The rotating platen 3 rotates horizontally, i.e., spins on its own axis, around the axis of the vertical shaft 2. The rotating platen 3 is made up of a table (mortar disc) 31, an upper punch holding portion 32, and a lower punch holding portion 33. As shown in FIG. 2, the table 31 is substantially disk-shaped and has a plurality of die holes 4 at predetermined intervals along the direction of rotation on its outer periphery. The die holes 4 penetrate the table 31 in the vertical direction. The table 31 may be divided into a plurality of plates. Also, the table 31 may not directly have the die holes 4, but may have a die with the die holes 4 attached to it.

[0025] Above and below each die hole 4, an upper punch 5 and a lower punch 6 are placed, each of which can slide up and down independently relative to the die hole 4, with the upper punch body 52 held by the upper punch holding portion 32 and the lower punch body 62 held by the lower punch holding portion 33. The punch tip 53 of the upper punch 5 moves in and out of the die hole 4. The punch tip 63 of the lower punch 6 is always inserted in the die hole 4. The upper punch 5 and lower punch 6 rotate horizontally, i.e., revolve, around the axis of the vertical shaft 2 together with the turntable 3.

[0026] A rotary encoder 123 that detects the rotation angle and rotation speed of the gear shaft 9 and therefore the turntable 3 (the table 31, the die hole 4, and the punches 5 and 6) is connected to the end of the gear shaft 9 via a reduction gear 124. The rotary encoder 123 outputs a pulse signal each time the gear shaft 9 rotates a predetermined angle. By receiving this pulse train, the control device C of this system can detect the rotation angle and rotation speed of the turntable 3, that is, it can know which die hole 4 on the table 31 is currently in which position. The reduction gear 124 reduces the rotation speed of the gear shaft 9 to a value suitable for the input speed of the rotary encoder 123 and transmits it to the rotary encoder 123.

[0027] A feeder X, which is a filling device, is used to fill the die hole 4 of the rotating platen 3 with powder. The feeder X may be an open feeder that simply drops the powder into the die hole 4, or an agitating feeder that rotates a built-in agitating blade to agitate the powder and drop it into the die hole 4, but this embodiment assumes an agitating feeder. The feeder X is located on the outer periphery of the rotating table 31, particularly directly above the rotation path of the die hole 4. Powder is supplied to the feeder X from a discharge portion M6 of the powder measuring device M described later and a powder supply pipe 191 (shown in FIG. 4). A buffer tank 19 is used to supply powder to the inlet M5 of the powder measuring device M.

[0028] As shown in Fig. 3, on the revolution orbit of the upper punch 5 and the lower punch 6 around the axis of the vertical shaft 2, there are a pre-pressing upper roll 12 and a pre-pressing lower roll 13, and a main pressing upper roll 14 and a main pressing lower roll 15 which are paired vertically to sandwich the upper punch 5 and the lower punch 6. The pre-pressing upper roll 12 and the main pressing upper roll 14 press the head 51 of the upper punch 5, and the pre-pressing lower roll 13 and the main pressing lower roll 15 press the head 61 of the lower punch 6. The pre-pressing upper roll 12 and the pre-pressing lower roll 13, and the main pressing upper roll 14 and the main pressing lower roll 15 urge the upper punch 5 and the lower punch 6 in a direction to approach each other so that the powder filled in the die hole 4 is compressed from above and below by the tip surfaces of the punch tips 53 and 63.

[0029] The upper punch 5 and the lower punch 6 have heads 51 and 61 pressed by the rolls 12, 13, 14 and 15, respectively, and body parts 52 and 62 having a smaller diameter than the heads 51 and 61. The upper punch holding part 32 of the turntable 3 holds the body part 52 of the upper punch 5 so that it can slide up and down, and the lower punch holding part 33 holds the body part 62 of the lower punch 6 so that it can slide up and down. The tip parts 53 and 63 of the body parts 52 and 62 are thinner than the other parts so that they can be inserted into the die hole 4, and have a diameter approximately equal to the inner diameter of the die hole 4. As the punches 5 and 6 revolve, the rolls 12, 13, 14 and 15 approach the heads 51 and 61 of the punches 5 and 6, and come into contact with the heads 51 and 61 by climbing up onto them. Furthermore, the rolls 12, 13, 14, and 15 press the upper punch 5 downward and press the lower punch 6 upward. While the rolls 12, 13, 14, and 15 are in contact with the flat surfaces of the punches 5 and 6, the punches 5 and 6 continue to apply a required pressure to the powder in the die hole 4.

[0030] A load cell 120 is attached to the upper rolls 12 and 14 of the molding machine. The load cell 120 detects the pressure when the rolls 12, 13, 14, and 15 compress the powder in the die hole 4 through the punches 5 and 6. The control device C of this embodiment can know the magnitude of the pressure (pre-compression pressure) with which the pre-compression rolls 12 and 13 compress the powder and the magnitude of the pressure (main pressure) with which the main pressure rolls 14 and 15 compress the powder by receiving the signal output from the load cell 120 attached to the rolls 12, 13, 14, and 15. In addition, the signal provided from the load cell 120 takes the form of a pulse signal train that reaches a peak at the time when the pressure with which one pair of punches 5 and 6 compresses the powder in one die hole 4 becomes maximum. Therefore, the control device C can know the number of molded products manufactured per unit time in the molding machine by counting the number of the pulse train.

[0031] A molded product recovery section is located downstream from the pressure position by the main pressure upper roll 14 and the main pressure lower roll 15 in the direction of rotation of the turntable 3, upper punch 5, and lower punch 6. This molded product recovery section is equipped with a damper 17 that guides the molded product pushed out of the die hole 4. The damper 17 has a base end at the molded product recovery position 18 and extends so that its tip is closer to the center of the table 31 than the rotation trajectory of the die 4. The molded product pushed out of the die hole 4 by the lower punch 6 comes into contact with this damper 17 and moves toward the molded product recovery position 18.

[0032] To outline the manufacturing process of a molded product, first, as shown in Fig. 3, the lower punch 6 descends, and the powder (mixed powder) is filled from the feed shoe X into the die hole 4 into which the punch tip 63 of the lower punch 6 is inserted (filling process). Next, the lower punch 6 rises so that the amount of powder (mixed powder) filled in the die hole 4 becomes the required amount, and the powder overflowing from the die hole 4 is scraped off.

[0033] Then, the upper punch 5 descends, and the pre-compression upper roll 12 and the pre-compression lower roll 13 press against the head 51 of the upper punch 5 and the head 61 of the lower punch 6, and the tips 53, 63 of the punches 5, 6 perform pre-compression to compress the powder in the die hole 4. Next, the main compression upper roll 14 and the main compression lower roll 15 press against the head 51 of the upper punch 5 and the head 61 of the lower punch 6, and the tips 53, 63 of the punches 5, 6 perform main compression to compress the powder in the die hole 4 (compression molding process).

[0034] Thereafter, the lower punch 6 rises until the upper end surface of the punch tip 63 of the lower punch 6 is at substantially the same height as the upper end of the die hole 4, i.e., the upper surface of the table 31, and the molded product in the die hole 4 is pushed out from the die hole 4 onto the platen surface. The molded product coming out of the die hole 4 comes into contact with the damper 17 as the turntable 3 rotates, and moves along the damper 17 to the molded product recovery position 18.

[0035] The molded product recovery section of this molding machine is provided with a molded product rejection mechanism W for selecting specific molded products, such as sampling products or defective products, from a group of molded products to be recovered at a molded product recovery position 18. Specifically, an air passage 16 for circulating pressurized air (which may be an inert gas such as nitrogen or other types of gas) is formed inside the damper 17, and the tip of the air passage 16 is an air injection nozzle 16a that opens outward along the radial direction of the rotating platen 3. A control valve 122 for opening and closing the passage 121 is provided on a flow path 121 that connects an air supply source (not shown) such as a pump that supplies pressurized air to the air passage 16. The control valve 122 is, for example, an electromagnetic solenoid that opens in response to a control signal provided from the control device C.

[0036] When the control valve 122 is opened when a specific molded product pushed out of the die hole 4 passes near the air injection nozzle 16a before contacting the damper 17, pressurized air supplied from the air supply source is ejected from the air injection nozzle 16a via the flow path 121 and the air passage 16 in the damper 17. This ejected air blows the specific molded product outward from the table 31. The blown-out molded product does not reach the molded product recovery position 18 located further along the damper 17. Thus, in this molding machine, the flow passages 16, 121 for the air supplied from the air supply source, the injection nozzle 16a, and the control valve 122 constitute a molded product removal mechanism W.

[0037] Incidentally, the molded product removal mechanism W can also be used for sampling the compressed molded products.

[0038] Hereinafter, a detailed description will be given of the powder mixing supplying device Z, which is a device that supplies mixed powder to the buffer tank 19, in other words, a device that sends out mixed powder toward a supply pipe 191 directly connected to the feeder X of the molding machine. As shown in Fig. 4, in this embodiment, three measuring feeders Z1 (Z1a, Z1b, Z1c) are used in the powder mixing supplying device Z. The number of measuring feeders Z1 varies depending on the number of types of powder to be mixed, so it may be two or four or more, and is not particularly limited.

[0039] In this embodiment, the first measuring feeder Z1a, the second measuring feeder Z1b, and the third measuring feeder Z1c each measure and feed different kinds of powders, but they may also measure and feed the same kind of powders. In this embodiment, the first measuring feeder Z1a measures and feeds the main drug, the second measuring feeder Z1b measures and feeds powders such as excipients such as lactose, and the third measuring feeder Z1c measures and feeds the lubricant.

[0040] As shown in Fig. 4, the powder mixing and supplying device Z is composed of a first metering feeder Z1a, a second metering feeder Z1b, a vertical mixer Z3 (first mixer), a first connecting pipe Z2a connecting the metering feeders Z1 (Z1a, Z1b) and the vertical mixer Z3, a horizontal mixer Z4 (second mixer), a second connecting pipe Z2b connecting the vertical mixer Z3 and the horizontal mixer Z4, a third connecting pipe Z2c connecting the third metering feeder Z1c and the horizontal mixer Z4, a vertical mixer Z5 (third mixer), a fourth connecting pipe Z2d connecting the horizontal mixer Z4 and the vertical mixer Z5, and a fifth connecting pipe Z2e connecting the vertical mixer Z5 and the buffer tank 19. The arrangement and shape of the metering feeders (Z1a, Z1b, Z1c) can be changed and are not limited to the embodiment shown in Fig. 4.

[0041] Each of the first and second measuring feeders Z1a and Z1b measures and supplies powders, i.e., main agents and excipients, to the first connecting pipe Z2a. The third measuring feeder Z1c measures and supplies powders, i.e., lubricants, to the third connecting pipe Z2c (measurement supply process). These measuring feeders Z1 are, for example, known loss-in-weight type (integrated weight loss type) types, and are feedback-controlled devices in which the weight of the powder discharged from the feeder Z1 is constantly measured via a weight sensor, and whether the weight transition matches the set target discharge flow rate is compared, and the discharge speed of the feeder Z1 is increased or decreased in the direction in which the deviation between the two is reduced. In this way, the content of the main agent, etc. in the molded product is stabilized by supplying each powder to be supplied to the connecting pipes Z2a and Z2c while measuring it.

[0042] As already mentioned, the first connecting pipe Z2a is a pipe connecting the first metering feeder Z1a and the second metering feeder Z1b to the vertical mixer Z3, and supplies the main drug discharged from the first metering feeder Z1a and the excipients discharged from the second metering feeder Z1b to the vertical mixer Z3. The second connecting pipe Z2b is a pipe connecting the vertical mixer Z3 to the horizontal mixer Z4, and supplies the mixed powder of the main drug and excipients discharged from the vertical mixer Z3 to the horizontal mixer Z4. The third connecting pipe Z2c is a pipe connecting the third metering feeder Z1c to the horizontal mixer Z4, and supplies the lubricant discharged from the third metering feeder Z1c to the horizontal mixer Z4. The fourth connecting pipe Z2d is a pipe connecting the horizontal mixer Z4 to the vertical mixer Z5, and supplies the mixed powder of the main drug, excipients and lubricant discharged from the horizontal mixer Z4 to the vertical mixer Z5. The fifth connecting pipe Z2e is a pipe that connects the vertical mixer Z5 and the buffer tank 19, and supplies the mixed powder of the main drug, excipient, and lubricant discharged from the vertical mixer Z5 to the buffer tank 19.

[0043] More specifically, the first connecting pipe Z2a is composed of a first branch pipe Z2a1 connected to the first metering feeder Z1a, a second branch pipe Z2a2 connected to the second metering feeder Z1b, and a main pipe Z2a3 connected to the first branch pipe Z2a1 and the second branch pipe Z2a2. The lower part of the main pipe Z2a3 is connected to the vertical mixer Z3. As a result, the powders metered and fed from the first metering feeder Z1a and the second metering feeder Z1b are mixed in the vertical mixer Z3 (first mixing process).

[0044] As shown in Fig. 5, Fig. 6 and Fig. 7, the vertical mixer Z3, which is the first mixer, is composed of a cover part Z36 having a supply port Z361 through which powder is supplied, a funnel-shaped first case Z31 located below the cover part Z36, a rotating agitation shaft Z33 located at the approximate center of the first case Z31, a stirring blade Z34 (first mixing member) attached to the stirring shaft Z33, a motor Z37 for rotating (rotating) the agitation shaft Z33, a powder passing member Z32 located at the bottom of the first case Z31 and having a plurality of holes Z321, an auxiliary blade Z35 (first mixing member) for encouraging the powder to pass through the holes Z321 of the powder passing member Z32, and a second case Z38 covering the powder passing member Z32. Here, both the stirring blade Z34 and the auxiliary blade Z35 are the first mixing members. In this embodiment, the configuration is such that both the stirring blade Z34 and the auxiliary blade Z35 are provided, but only one of them may be provided.

[0045] In the vertical mixer Z3, the stirring shaft Z33 does not necessarily need to be arranged vertically, and may be inclined. The vertical mixer Z3 may be any device that can stir and mix the powder supplied from the supply port Z361 while flowing downward.

[0046] The powder fed to the feed port Z361 of the vertical mixer Z3 is mixed by the rotation of the stirring blade Z34 (first mixing step). Of course, the powder may be mixed by the rotation of the auxiliary blade Z35.

[0047] The cover Z36 has a supply port Z361 and a shaft port Z362 for passing the stirring shaft Z33, and is shaped to cover the upper opening of the first case Z31. The cover Z36 is attached to the first case Z31 so that the powder does not spill or scatter from the first case Z31. The supply port Z361 of the cover Z36 is connected to the first connecting pipe Z2a. The powder supplied from the supply port Z361 into the first case Z31 is stirred and mixed by the rotation of the stirring blade Z34 and / or the auxiliary blade Z35. The powder passing member Z32 of the storage section Z30 has a plurality of holes Z321, and the mixed powder passes through the holes Z321 of the powder passing member Z32.

[0048] By adjusting the amount of powder supplied from the supply port Z361 or by increasing the rotation speed of the auxiliary blade Z35, the amount of powder supplied from the supply port Z361 can be made greater than the amount of powder passing through the hole Z321. Therefore, the powder remains in the storage section Z30 to a certain extent. In other words, in the vertical mixer Z3, at least a portion of the powder metered and supplied from the first metering feeder Z1a and the second metering feeder Z1b remains in the storage section Z30 (storing process), and is stirred by the auxiliary blade Z35, improving the degree of mixing of the powder. A plurality of supply ports Z361 may be provided.

[0049] The first case Z31 has an opening at its top, and the powder passing member Z32 is provided at its bottom. In this embodiment, the shape of the first case Z31 is substantially funnel-shaped, but is not limited to this shape, and may be any shape as long as it is configured to supply powder to the powder passing member Z32.

[0050] The stirring shaft Z33 is provided in the center of the first case Z31 in a plan view, and rotates (spins) by driving a motor Z37. Agitating blades Z34 are attached to the upper and central parts of the axial direction of the stirring shaft Z33, and an auxiliary blade Z35 is attached to the lower part. When the stirring shaft Z33 rotates, the stirring blades Z34 and the auxiliary blades Z35 rotate.

[0051] The stirring blade Z34 (first mixing member) stirs and mixes the powder supplied from the supply port Z361 into the first case Z31. The shape of the stirring blade Z34 may be any shape. In FIG. 5, the stirring blade Z34 has a rectangular tip and is arranged at two places on the stirring shaft Z33. On the other hand, the vertical mixer Z3 shown in FIG. 7 is partially different in structure from the vertical mixer Z3 shown in FIG. 5. In the vertical mixer Z3 shown in FIG. 7, the stirring blade Z34 is arranged at one place on the stirring shaft Z33 and has a different shape from the stirring blade Z34 in FIG. 5. Note that FIGS. 5 and 7 do not limit the shape or arrangement position of the stirring blade Z34.

[0052] As shown in FIG. 6, the powder passing member Z32 in the storage section Z30 is provided at the bottom of the first case Z31 and has a plurality of holes Z321. The powder passing member Z32 is covered by the second case Z38. The powder passing through the holes Z321 of the powder passing member Z32 is discharged from the outlet Z381 provided at the bottom of the second case Z38. The number and diameter of the holes Z321 are optional. With this configuration, the powder remains in the powder passing member Z32, improving the degree of mixing of the powder. In the first vertical mixer Z3a, the powder passing through the holes Z321 of the powder passing member Z32 is supplied to the horizontal mixer Z4 via the second connecting pipe Z2b.

[0053] The auxiliary blade Z35 agitates the powder in the storage section Z30. The auxiliary blade Z35 is provided in the center of the storage section Z30 in a plan view, and is provided below the agitation shaft Z33. In this embodiment, the shape of the auxiliary blade Z35 is structured to match the internal shape of the powder passing member Z32, and promotes the powder to pass through the hole Z321. The auxiliary blade Z35 is also a type of agitation blade.

[0054] In addition, the vertical mixer Z3 of this embodiment is equipped with the stirring blade Z34, but the vertical mixer Z3 may be composed of a second case Z38, a powder passing member Z32, and an auxiliary blade Z35. The second case Z38 covers the powder passing member Z32, has a substantially funnel-like shape, and has a discharge port Z381 at the bottom. The second case Z38 guides the powder that has passed through the hole Z321 of the powder passing member Z32 to the discharge port Z381.

[0055] The second connecting pipe Z2b is a pipe that connects the vertical mixer Z3 and the horizontal mixer Z4. The second connecting pipe Z2b is connected to the lower part of the vertical mixer Z3 and the upper part of the horizontal mixer Z4, and supplies the powder that has passed through the discharge port Z381 of the vertical mixer Z3 to the horizontal mixer Z4.

[0056] As shown in Fig. 4 and Fig. 24, the horizontal mixer Z4, which is the second mixer, is composed of a cylindrical case Z41, a rotating agitator shaft Z42 arranged in the approximate center of the case Z41, a motor Z43 that rotates (rotates) the agitator shaft Z42, and an agitator blade Z44 that is attached to the agitator shaft Z42 and moves the powder in an approximately horizontal direction by rotation. The horizontal mixer Z4 mixes the supplied powder, i.e., the main drug, excipients, etc., with the lubricant (second mixing step). In this embodiment, the case Z41 does not rotate (rotates), but the case Z41 may be configured to rotate. In this case, the degree of mixing of the powder is further improved.

[0057] The case Z41 has a plurality of supply ports at the top for supplying powder into the case Z41, and a discharge port Z413 for discharging the mixed powder from the case Z41. In this embodiment, two supply ports (a first supply port Z411 and a second supply port Z412) are used, and the second connecting pipe Z2b is connected to the first supply port Z411 in the case Z41 of the horizontal mixer Z4. The first supply port Z411 is a supply port for supplying a powder mixed with a main agent and an excipient into the case Z41. The mixed powder supplied into the case Z41 moves toward the discharge port Z413 of the case Z41 by the rotation of the stirring blade Z44. The second supply port Z412 is a supply port for supplying the lubricant provided from the third connecting pipe Z2c. The lubricant supplied into the case Z41 moves toward the discharge port Z413 of the case Z41 by the rotation of the stirring shaft Z42 and the stirring blade Z44. Any supply ports that are not in use are closed with lids.

[0058] The discharge port Z413 is disposed at the bottom of the case Z41. The discharge port Z413 is connected to the fourth connecting pipe Z2d. The mixed powder in the case Z41 is discharged from the discharge port Z413 by the rotation of the stirring blade Z44 and moves to the fourth connecting pipe Z2d.

[0059] The stirring shaft Z42 extends in the longitudinal direction of the case Z41 and is disposed in the approximate center in cross-sectional view. The stirring shaft Z42 rotates (spins) by being driven by a motor Z43. As shown in Fig. 8, a stirring blade Z44 is attached to the stirring shaft Z42. When the stirring shaft Z42 rotates, the stirring blade Z44 rotates, and the powder moves toward the discharge port Z413 while being mixed.

[0060] The stirring blade Z44 is for stirring and mixing the powder supplied from the supply ports (Z411, Z412) into the case Z41. The shape of the stirring blade Z44 may be any, but it is preferable that the stirring blade Z44 is configured to mix the powder and flow it toward the discharge port Z413. As shown in Fig. 8, in this embodiment, both ends of the stirring blade Z34 are widened, and the angle of the stirring blade Z44 with respect to the stirring shaft Z42 can be freely adjusted.

[0061] The third metering feeder Z1c is for metering and supplying the lubricant to the horizontal mixer Z4. A third connecting pipe Z2c is connected to the lower part of the third metering feeder Z1c. The lubricant in the third metering feeder Z1c is supplied to the horizontal mixer Z4 through the third connecting pipe Z2c (lubricant supplying step). The lubricant may be supplied to the horizontal mixer Z4 by a μR feeder (manufactured by Nisshin Engineering Co., Ltd.). A spraying device (spraying device) may be used to supply the lubricant to the horizontal mixer Z4.

[0062] The third connecting pipe Z2c includes a branch pipe Z2c1 and a main pipe Z2c2. One end of the branch pipe Z2c1 is connected to the lower part of the third measuring feeder Z1c, and the other end is connected to the main pipe Z2c2. The lower part of the main pipe Z2c2 is connected to the second supply port Z412 of the horizontal mixer Z4.

[0063] The fourth connecting pipe Z2d is a pipe that connects the horizontal mixer Z4 and the vertical mixer Z5. The fourth connecting pipe Z2d is connected to the lower part of the horizontal mixer Z4 and the upper part of the vertical mixer Z5, and supplies the powder that has passed through the discharge port Z413 of the horizontal mixer Z4 to the vertical mixer Z5.

[0064] The vertical mixer Z5, which is the third mixer, can have the same configuration as the vertical mixer Z3 shown in Figures 5 to 7. Therefore, a description thereof will be omitted here. The upper end of the fourth connecting pipe Z2d is connected to the discharge port Z413 of the horizontal mixer Z4, and the lower end is connected to the supply port of the vertical mixer Z5. The vertical mixer Z5 has a stirring blade and an auxiliary blade attached to a stirring shaft that is vertical or inclined obliquely from the vertical. These stirring blades and auxiliary blades are both third mixing members. The powder supplied to the supply port of the vertical mixer Z5 through the fourth connecting pipe Z2d is mixed by the stirring blade and auxiliary blade that rotate together with the stirring shaft (third mixing process).

[0065] The fifth connecting pipe Z2e has an upper end connected to the discharge port of the vertical mixer Z5 and a lower end connected to the supply port Z361 of the buffer tank 19. The powder mixed by the vertical mixer Z5 is supplied to the buffer tank 19 from the discharge port of the vertical mixer Z5 through the fifth connecting pipe Z2e.

[0066] The lower part of the buffer tank 19 is connected to the powder compression molding machine. The mixed powder that has passed through the buffer tank 19 is supplied to a feed shoe X in the powder compression molding machine, and is finally compression molded in the die hole 4.

[0067] Thus, the mixed powder sent from the buffer tank 19 of the powder mixing supplying device Z to the powder compression molding machine has its properties, particularly the degree of mixing, measured by the powder measuring device M and other locations inside the powder mixing supplying device Z. If the degree of mixing or other properties are outside of a predetermined range, the defective mixed powder is removed, an alarm is sounded, the device is stopped, or other measures are taken. In other words, the powder mixing supplying device Z measures the properties of the mixed powder in real time and takes appropriate measures.

[0068] There are various methods for measuring the mixing degree and other properties of the mixed powder, such as Raman spectroscopy, infrared spectroscopy, X-ray diffraction, X-ray transmission measurement, high performance liquid chromatography (HPLC), etc., but any method may be used as long as it can measure the mixing degree and other properties of the mixed powder in real time. In this embodiment, near-infrared spectroscopy (NIR, or near-infrared absorption spectroscopy) is mainly used. That is, in order to evaluate the amount or ratio (ratio) of the main drug in the mixed powder moving from the powder mixing and supplying device Z to the feeder X of the molding machine, in other words, the uniformity of the mixed powder (whether segregation occurs or not), near-infrared light is irradiated to the moving mixed powder, the absorption and reflection (scattering) of light are measured, and the concentration of the main drug and other qualitative and quantitative analyses are performed based on the spectrum, and this is repeated at a predetermined cycle. As the measurement wavelength, a wavelength band that has no peaks of excipients or lubricants and is a specific absorption peak of the main drug is used. In addition, near-infrared spectroscopy can also measure the particle size of the mixed powder.

[0069] In this embodiment, a near-infrared sensor is used as a PAT (Process Analytical Technology) sensor for measuring the mixing degree of powder, etc. As shown in Fig. 4, in this embodiment, first, before the mixed powder is stored in the buffer tank 19, the mixing degree of the mixed powder, etc. is measured using a first sensor S1 which is a near-infrared sensor.

[0070] The powder mixed by the powder mixing supply device Z is temporarily stored in a buffer tank 19, which is a storage device, after the degree of mixing and the like is measured by a first sensor S1. The powder stored in the buffer tank 19 is again measured for the degree of mixing and the like by a near-infrared sensor S2, and is then supplied to the powder measuring device M. Note that the mixed powder may be further stirred and mixed in the buffer tank 19.

[0071] As shown in Figures 9 and 10, the powder measuring device M comprises a case M1, a rotating body M2 which is a moving member located within the case M1 and which captures and transports the mixed powder, a servo motor or stepping motor M3 which is a drive device for driving the rotating body M2, near-infrared sensors S2 and S3 which are sensors for measuring the properties of the mixed powder, in particular the degree of mixing, a powder removal section M4 for removing mixed powder with poor properties, an inlet M5 for introducing the mixed powder from the buffer tank 19 into the case M1, and a discharge section M6 which discharges the mixed powder into an agitating feeder X which is a filling device of the molding machine.

[0072] As shown in FIG. 11, the bottom surface of the case M1 is provided with a mounting hole M11 for installing a near-infrared sensor S3, a rejection hole M12 for dropping in and rejecting defective mixed powder, and a discharge hole M13 for discharging normal mixed powder to a powder supply pipe 191 connected to the feeder X of the molding machine. The rejection hole M12 is located in a powder rejection section M4, and the discharge hole M13 is located in a discharge section M6. An inlet M5 for supplying powder into the case M1 is provided at the top of the case M1. The mixed powder reaches the inside of the case M1 via a buffer tank 19 and the inlet M5. A second sensor S2, which is a near-infrared sensor for measuring the properties such as the degree of mixing of the mixed powder passing through the inlet M5, is provided at the inlet M5.

[0073] The rotor M2 has a plurality of blades M22 extending radially in a plan view, and the gaps between the blades M22 form pocket-like moving parts M21. A plurality of moving parts M21 are intermittently arranged along the rotation direction, i.e., the circumferential direction, of the rotor M2, and each of them captures the mixed powder supplied from the introduction port M5. The rotor M2 is driven by a motor M3 located above the rotor M2 to rotate horizontally. As the rotor M2 rotates, the mixed powder captured by each moving part M21 is pushed by the blades M22 and transferred.

[0074] The third sensor S3, which is a near-infrared sensor, is attached to the mounting hole M11 of the case M1 and is used to measure the properties such as the degree of mixing of the powder supplied to and captured by the moving part M21. When the degree of mixing of the powder captured by the moving part M21 is measured by the third sensor S3, the rotation of the motor M3 and the rotating body M2 may be temporarily stopped. In other words, the rotating body M2 may rotate intermittently. When the degree of mixing of the powder currently flowing in the pipe is measured by the sensors S1, S2, and S4, the measured value may be unstable. If the rotation of the rotating body M2 and the powder captured by the moving part M21 are stopped and measured by the sensor S3, the density of the powder in the moving part M21 is constant, and the properties such as the degree of mixing of the powder can be measured very accurately.

[0075] The powder removal unit M4 is composed of a case, a driver M41 that serves as a shutter, and a driver M42 that drives the driver M41. The case of the powder removal unit M4 is integrated with the case M1. The driver M41 is disk-shaped in this embodiment, and includes a protrusion M411 in the center that engages with the driver M42, and a notch M412 in one portion. The driver M42 includes a tip portion M421 that moves back and forth in the Y-axis direction shown in FIG. 10, and includes an engagement hole M422 on the tip side that engages with the protrusion M411 of the driver M41.

[0076] When the tip M421 of the driver M42 moves in the positive direction of the Y axis as shown in Fig. 10, the notch M412 of the driver M41 is located at the center of the exclusion hole M12 of the case M1. Conversely, when the tip M421 moves in the negative direction of the Y axis, the notch M412 comes out of the exclusion hole M12 of the case M1.

[0077] In other words, when the tip M421 moves in the negative direction with respect to the Y-axis direction by the driving device M42, the driving body M41 moves clockwise in conjunction with the tip M421, so that the notch M412 does not overlap with the exclusion hole M12. As a result, the powder in the moving part M21 of the rotating body M2 is not excluded. When the tip M421 moves in the positive direction with respect to the Y-axis direction by the driving device M42, the driving body M41 moves counterclockwise in conjunction with the tip M421, so that the notch M412 overlaps with the exclusion hole M12. As a result, the powder in the moving part M21 of the rotating body M2 is excluded.

[0078] In this embodiment, the driver M41 drives clockwise and counterclockwise to remove powder from the moving part M21 of the rotating body M2, but the driver M41 may rotate in only one direction to remove powder from the moving part M21.

[0079] When it is found that the degree of mixing of the powder measured by the first sensor S1, the second sensor S2, and / or the third sensor S3, i.e., the amount or ratio (proportion) of the main agent in the mixed powder, is outside a predetermined range, the mixed powder in the moving section M21 is removed by the powder removing section M4. Note that the mixed powder in the moving section M21 may be removed when all the measured values ​​of the degree of mixing by the first sensor S1, the second sensor S2, and the third sensor S3 are outside the predetermined range, or the mixed powder in the moving section M21 may be removed when the measured value by any of the sensors S is outside the predetermined range.

[0080] Incidentally, the powder removal section M4 can also be used for sampling mixed powders.

[0081] The mixed powder that is not removed by the powder removal section M4 reaches the discharge section M6, and moves to the powder supply pipe 191 through the discharge hole M13.

[0082] Here, a supplementary explanation will be given regarding the third sensor S3 of the powder measuring device M. The third sensor S3 irradiates light waves (or electromagnetic waves) on the powder during the process of transferring the mixed powder from the inlet M5 to the discharge part M6 (discharge hole M13) in the powder measuring device M, receives the reflected light (reflected wave) reflected by the powder or the transmitted light (transmitted wave) that has passed through the powder with a sensor probe, and measures the spectrum. In this embodiment, a reflective near-infrared sensor is assumed as the third sensor S3. That is, the sensor probe S3 irradiates near-infrared light on the mixed powder captured and transferred by the moving part M21 of the rotating body M2, and receives the reflected light reflected by the mixed powder.

[0083] The sensor probe S3 is located directly below the transport path of the mixed powder, faces upward, and faces the flowing mixed powder from below. In other words, the mixed powder to be measured passes directly above the sensor probe S3. Therefore, dust originating from the powder and dust not originating from the powder may adhere to the sensor probe S3. The dust causes noise to be mixed into the spectrum of the reflected light that is reflected by the mixed powder to be measured, which should be received by the sensor probe S3.

[0084] Even if this is not the case, the input / output characteristics of the sensor probe S3, i.e., the relationship between the properties of the powder to be measured and the signal output by the sensor probe S3 that measures the properties, may change as the sensor probe S3 changes over time. Therefore, it is necessary to check or calibrate the input / output characteristics of the sensor probe S3 from time to time.

[0085] In the powder measuring device M of this embodiment, the input / output characteristics of the sensor probe S3 can be confirmed or calibrated while the sensor probe S3 is attached to the attachment hole M11 of the case M1 without removing the sensor probe S3 from the case M1. For this purpose, as shown in Figs. 10 and 14, a standard sample (reference piece) M23 for calibrating the sensor probe S3 is attached to the blade M22 of the rotating body M2 in advance. The standard sample M23 is filled with a standard (reference) powder whose mixing degree and other properties are known and whose properties are always constant. In the example shown in Fig. 14, a recess is formed on the downward surface of the blade M22, which is recessed upward, and the standard sample M23 is embedded therein. The standard sample M23 may be provided on at least one blade M22 of the rotating body M2, but may be provided on each of the multiple blades M22.

[0086] The blade M22 of the rotating body M2 passes directly above the sensor probe S3 together with the powder captured by the moving part M21. The blade M22 is between the adjacent moving parts M21 and separates the moving parts M21. That is, as the rotating body M2 rotates, the mixed powder passes intermittently near the sensor probe S3, and when the mixed powder is not present near the probe S3, that is, when the blade M22 passes, the standard sample M23 provided on the downward surface of the blade M22 facing the probe S3 passes near the probe S3. Near-infrared light is irradiated from the sensor probe S3 to the standard sample M23, and the reflected light that hits the standard sample M23 is received by the probe S3. When the standard sample M23 provided on the blade M22 is measured via the third sensor S3, the rotation of the motor M3 and the rotating body M2 may be temporarily stopped.

[0087] The properties of the standard sample M23 are known and constant, and it is naturally possible to predict the inherent spectrum of the light reflected from the standard sample M23 and the inherent signal output by the sensor probe M3 that receives the reflected light. Therefore, the control device C can confirm the current input / output characteristics of the sensor probe S3 by comparing the standard output signal of the sensor probe S3 that corresponds to the inherent spectrum with the actual output signal of the sensor probe S3 that receives the light reflected from the standard sample M23.

[0088] Fig. 19 shows a specific example of the measurement results by the sensor probe S3. The horizontal axis of Fig. 19 is time (hour), and the vertical axis is the absorbance of the measurement target obtained based on the output signal of the sensor probe M3 that received the reflected light. At each of the timings t1, t2, t3, t4, and t5 in Fig. 19, the standard sample M23 passes near, i.e. directly above, the probe S3, and the reflected light that hits the standard sample M23 and is reflected enters the probe S3. In Fig. 19, the absorbance of the standard sample M23 is shown by a dashed line, and the upper and lower limits of the appropriate range of the measurement result are shown by dashed double-dot lines.

[0089] If the output signal of the sensor probe S3 that measured the standard sample M23 is within the desired range, or if the difference between the ideal output of the sensor probe S3 and the actual output is smaller than a certain value, the input characteristics of the current sensor probe S3 are appropriate. In Fig. 19, the results of measuring the absorbance of the standard sample M23 at times t1, t2, t3, and t4 are within the appropriate range, and therefore the input / output characteristics of the sensor probe S3 at these times are appropriate.

[0090] On the other hand, if the output signal of the sensor probe S3 that measured the standard sample M23 is not within the desired range, or if the difference between the ideal output of the sensor probe S3 and the actual output is larger than a certain value, the current characteristics of the sensor probe S3 are inappropriate. In Fig. 19, the result of measuring the absorbance of the standard sample M23 at time t5 is not within the appropriate range, and therefore the input / output characteristics of the sensor probe S3 at this time are inappropriate.

[0091] When the control device C determines that the characteristics of the current sensor probe S3 are inappropriate, it may, for example, sound an alarm to that effect, light or blink a lamp, or stop the operation of the powder mixing and supplying device Z and / or the molding machine to prompt cleaning or replacement of the sensor probe S3. Alternatively, the control device C may change the calibration curve used when measuring the properties of the mixed powder, such as the degree of mixing, to match the characteristics of the current sensor probe S3.

[0092] When it is determined that the characteristics of the current sensor probe S3 are inappropriate, the probe S3 may be automatically cleaned. For example, as shown in FIG. 15, a nozzle M24 for spraying pressurized air (which may be an inert gas such as nitrogen or other types of gas) toward the sensor probe S3 is provided inside the case M1 of the powder measuring device M. The nozzle M24 is connected to an air supply source (not shown) such as a pump via a flow path (not shown) for passing the pressurized air, and a control valve M25 for opening and closing the flow path is provided on the flow path. The control valve M25 is, for example, an electromagnetic solenoid that opens in response to a control signal provided by the control device C. In addition, a shutter or valve M51 capable of blocking communication between the buffer tank 19 and the powder measuring device M is provided upstream of the powder measuring device M, between the buffer tank 19 and the inlet M5, or within the inlet M5.

[0093] If the control device C determines that the current characteristics of the sensor probe S3 are inappropriate, it first closes the shutter, valve, etc. M51 to temporarily block communication between the buffer tank 19 and the powder measuring device M, thereby preventing the mixed powder from flowing into the powder measuring device M. In this state, it continues to rotate the rotor M2, and discharges most or all of the mixed powder in the powder measuring device M from the discharge hole M12 (powder discharge section M4) and / or the discharge port M13 (discharge section M6) so that little or no powder remains in the measuring device M. Next, it opens the control valve M24, and jets pressurized air supplied from the air supply source from the nozzle M24, thereby blowing away and removing dust or dirt adhering to the sensor probe M3 with the pressurized air. Thereafter, the control valve M24 is closed to stop the air from being sprayed from the nozzle M24, and the closed shutter or valve M51 is opened to reconnect the buffer tank 19 and the powder measuring device M5, thereby allowing the mixed powder to flow into the powder measuring device M.

[0094] 10 and 16, a cleaning material M26 that comes into contact with and wipes off the sensor probe S3 may be attached in advance to the downward surface of the blade M22 of the rotating body M2. The cleaning material M26 is a brush or wiper rubber made of a material that does not damage the surface of the sensor probe S3 even if it rubs against it, such as a resin such as silicone rubber or nylon (polyamide). The cleaning material M26 comes into contact with and slides on the surface of the sensor probe S3 as the rotating body M2 and the blade M22 rotate, wiping off dust or dirt adhering to the sensor probe S3.

[0095] The above sensor S3 is a reflection type that receives light reflected from the mixed powder to be measured and measures the properties of the powder. In contrast, a transmission type sensor S3 may be used in the powder measuring device M that receives light transmitted through the mixed powder to be measured and measures the properties of the powder. In this case, as shown in FIG. 17, a light source S31 that emits light waves (electromagnetic waves, particularly near-infrared light) is disposed at a position facing the sensor probe S3 across the transfer path of the mixed powder. A window M27 is opened in the blade M22 of the rotor M2 so that the light waves can pass through, and a standard sample M23 is embedded in the window M27. With this structure, the transmitted light emitted from the light source S31 and transmitted through the standard sample M23 can be made incident on the sensor probe S3, making it possible to confirm or calibrate the characteristics of the sensor probe S3.

[0096] The standard sample M23 is not necessarily provided on the blade M22 of the rotor M2. As shown in Fig. 18, an openable shutter M14 may be provided to cover the surface of the sensor probe S3 from above, and the standard sample M23 may be attached to the downward surface of the shutter M14. When the properties of the mixed powder are normally measured, the shutter M14 is opened, that is, the shutter M14 is retracted from above the sensor probe S3 to expose the surface of the sensor probe S3, and the sensor probe S3 is made to face the powder to be measured. When the characteristics of the sensor probe S3 are to be confirmed or calibrated, the shutter M14 is closed to cover the surface of the sensor probe S3, as shown in Fig. 18, and the sensor probe S3 is made to face the standard sample M23 provided on the shutter M14.

[0097] The cleaning material M73 is also not necessarily provided on the blade of the rotating body M2. In the modified example shown in Figures 20 and 21, a cleaning mechanism M7 is added that can clean the sensor probe S3 as needed or periodically during operation of the powder measuring device M. The cleaning mechanism M7 includes a moving member M72 that moves so as to pass near the sensor probe M3, a servo motor or stepping motor M71 that is a drive device for driving the moving member M72, and a cleaning material M73 provided on the moving member M72.

[0098] The moving member M72 is a thin disk disposed between the blade M22 and the probe M3 at a height position directly below the rotating body M2 and directly above the sensor probe M3. Windows M721 are intermittently provided along the circumferential direction around the central axis of rotation of the moving member M72 on the outer periphery of the moving member M72, facing the sensor probe M3. The windows M721 transmit light waves (electromagnetic waves, particularly near-infrared light) irradiated toward the mixed powder, reflected light (reflected waves) reflected by the mixed powder, or transmitted light (transmitted waves) that has passed through the mixed powder.

[0099] Furthermore, a cleaning material M73 that comes into contact with and wipes the sensor probe S3 is attached between adjacent windows M721 on the downward surface of the outer periphery of the movable member M72. The cleaning material M73 is a brush, wiper rubber, or the like made of a material that does not damage the surface of the sensor probe S3 even if it rubs against the surface, similar to the cleaning material M26 shown in Fig. 16. The cleaning material M73 comes into contact with and slides against the surface of the sensor probe S3 as the movable member M72 rotates, wiping off dust or dirt adhering to the sensor probe S3.

[0100] A standard sample M74 may be provided between adjacent windows M721 on the outer periphery of the movable member M72. The standard sample M74, like the standard sample M23 shown in Fig. 14 and Fig. 17, is filled with a standard powder whose mixing degree and other properties are known and whose properties are always constant.

[0101] As shown in Fig. 20, the moving part M21 that captures the mixed powder in the rotating body M2 is located near, i.e. directly above, the sensor probe M3, and when the properties of the mixed powder are measured by the probe S3, the window M721 of the moving member M72 is positioned directly above the probe M3. Then, when the properties of the mixed powder are not being measured, the moving member M72 is rotated as shown in Fig. 21, and cleaning is performed by wiping the surface of the probe S3 with the cleaning material M73. When the characteristics of the sensor probe M3 are to be confirmed or calibrated, the standard sample M23 provided on the blade M2 ​​and the window M721 of the moving member M72 are positioned so as to overlap directly above the probe S3, or the standard sample M74 provided on the moving member M72 is positioned directly above the probe S3.

[0102] The mixed powder, whose properties are measured by the sensor S3 of the powder measuring device M and which has moved to the powder supply pipe 191 through the discharge part M6, has its degree of mixing and the like measured by a fourth sensor S4 which is a near-infrared sensor before being introduced into the agitating feeder X which is a filling device of the molding machine. Furthermore, in this embodiment, the degree of mixing and the like of the mixed powder is also measured in the agitating feeder X of the molding machine using a fifth sensor S5 which is a near-infrared sensor.

[0103] If the degree of mixing of the powders measured by the fourth sensor S4 and / or the fifth sensor S5 is outside a predetermined range, the mixed powder is once filled into the die hole 4 of the table 31 of the molding machine from the feeder X, and is compressed and molded into a molded product by the upper punch 5 and the lower punch 6. The molded product is then removed by the molded product removal mechanism W before it reaches the molded product recovery position 18. That is, in the molding machine, when the die hole 4 filled with the defective mixed powder and into which the molded product has been tableted passes near the air injection nozzle 16a, the control valve 122 is opened, and air is injected from the air injection nozzle 16a to blow the molded product out of the table 31.

[0104] Generally speaking, if the first sensor S1, the second sensor S2 and / or the third sensor S3 determine that the properties of the mixed powder are outside of a specified range, the mixed powder is rejected by the powder rejection section M4, and if the fourth sensor S4 and / or the fifth sensor S5 determine that the properties of the mixed powder are outside of a specified range, the mixed powder is rejected by the molded product rejection mechanism W after compression molding.

[0105] In addition, even if the load cell 120 determines that the compression pressure when compressing the powder in the die hole 4 is outside the specified range, the molded product compressed in the die hole 4 is rejected by the molded product rejection mechanism W.

[0106] The flow of continuous compression molding carried out by the powder compression molding system of this embodiment will be reviewed. First, the main agent is measured and fed by the first measuring feeder Z1a, and the excipients and the like are measured and fed by the second measuring feeder Z1b (measurement and feeding process). Next, the powders of the main agent and the excipients are fed to the vertical mixer Z3, which is the first mixer, and mixed (first mixing process). In the vertical mixer Z3, the stirring blade Z34 rotates around the stirring shaft Z33, which is a shaft in the approximately vertical direction, to mix the powders of the main agent and the excipients and the like.

[0107] The mixed powder of the main drug and excipients, etc., that has been through the first mixing step is supplied to the horizontal mixer Z4, which is the second mixer, and mixed again (second mixing step). In the horizontal mixer Z4, the stirring blade Z44 rotates around the stirring shaft Z42, which is a substantially horizontal shaft, and mixes the powder of the main drug and excipients, etc. Through this step, the degree of mixing of at least two types of powder (main drug and excipients, etc.) is improved, and segregation of the main drug is less likely to occur.

[0108] The first mixing step preferably includes a storage step for storing at least a part of the powder. That is, in the powder passing member Z32 having a plurality of holes Z321, the powder passes through the holes Z321, but the amount of powder supplied to the first vertical mixer Z3a is made greater than the amount of powder passing through the holes Z321, or the rotation speed of the auxiliary blade Z35 is increased, so that the powder is stored in the storage section Z30. The powder passes through the holes Z321 while being mixed by stirring with the auxiliary blade Z35.

[0109] In addition to the above, the lubricant is measured and supplied by the third measuring feeder Z1c (lubricant supplying step). In this embodiment, the lubricant is supplied to the horizontal mixer Z4, but the supply location of the lubricant is not limited to the horizontal mixer Z4, and the lubricant may be supplied to, for example, the second vertical mixer Z3b or the feeder X. The lubricant may also be supplied using a μR feeder (manufactured by Nisshin Engineering Co., Ltd.) or a spray device (spray device).

[0110] Furthermore, after the second mixing step by the horizontal mixer Z4, the powder is supplied to the vertical mixer Z5 and mixed therein (third mixing step), thereby further improving the degree of mixing of the powder.

[0111] The mixed powder produced by mixing the main ingredient, excipients, etc., and lubricant is supplied to a buffer tank 19 connected to the molding machine. The mixed powder supplied to the buffer tank 19 is then measured for its degree of mixing by sensors S2 and S3 in a powder measuring device M (measurement step). Of course, the mixed powder degree of the mixed powder may be measured by sensor S1 before the mixed powder is supplied to the buffer tank 19.

[0112] If the measured degree of mixing of the mixed powder is outside a predetermined range, the mixed powder is rejected by the powder measuring device M (rejection process). The mixed powder is then supplied to a feeder X, which is a filling device. The degree of mixing of the mixed powder may be measured by a sensor S5 in the feeder X, or may be measured by a sensor S4 immediately before the mixed powder is supplied to the feeder X.

[0113] The mixed powder supplied to the feeder X is filled into the die hole 4 provided on the table 31 of the turntable 3 of the molding machine (filling process). The mixed powder filled into the die hole 4 is compression molded by the upper punch 5 and the lower punch 6 (compression molding process). The compression molded mixed powder is collected as a molded product by the damper 17 at the molded product collection position 18. However, the control device C of this system repeatedly measures the degree of mixing of the mixed powder supplied to the feeder X by the powder mixing supply device Z and filled into the die hole 4 via the fourth sensor S4 and / or the fifth sensor S5, and if the measured degree of mixing of the mixed powder is outside a predetermined range, a defective molded product compressed and molded in the die hole 4 filled with the mixed powder is rejected by the molded product rejection mechanism W equipped in the molding machine (molded product rejection process).

[0114] Furthermore, the control device C measures, via the load cell 120, the compression pressure when the powder is compressed in each die hole 4 by the punches 5, 6 to form a molded product, and if the compression pressure is out of a predetermined range, the molded product removal mechanism W removes a defective molded product that was compression molded in the die hole 4 where the compression pressure was out of the predetermined range (molded product removal process). If the die hole 4 is filled with more powder than the appropriate amount, the compression pressure measured by the load cell 120 becomes larger than the predetermined range, and if the die hole 4 is filled with less powder than the appropriate amount, the compression pressure measured by the load cell 120 becomes smaller than the predetermined range. In either case, the weight, density, and hardness of the molded product compressed in the die hole 4 deviate from the desired values, resulting in a defective molded product.

[0115] The timing when a die hole 4 that is presumably filled with a defective mixed powder whose degree of mixing is outside the specified range or a die hole 4 whose compression pressure is outside the specified range, in other words a molded product that may be defective, passes near the air injection nozzle 16a can be obtained by referring to the output signal of the rotary encoder 123.

[0116] In addition, prior to the filling process of filling the die hole 4 of the table 31 in the molding machine with powder, a lubricant (external lubricant) may be sprayed onto the lower end surface of the upper punch 5, the upper end surface of the lower punch 6, and the inner surface of the die hole 4 (lubricant supply process).

[0117] Originally, the feed weight (flow rate) of the main ingredient per unit time is feedback-controlled by the first metering feeder Z1a, the feed weight of the excipients, etc. per unit time is feedback-controlled by the second metering feeder Z1b, and the feed weight of the lubricant per unit time is feedback-controlled by the third metering feeder Z1c, and the mixture ratio between them should be the desired ratio. Nevertheless, for some reason, the amount of powder discharged from the metering feeder Z1 and supplied to the mixers Z3 and Z4 may deviate from the original target amount. In fact, the amount of powder supplied from the metering feeder Z1 to the mixers Z3 and Z4 is often less than the target amount, and as a result, the amount of the main ingredient in the mixed powder may not meet the desired ratio or may be excessive. A molded product obtained by compression molding such a mixed powder is a defective product that cannot exhibit the expected medicinal effect.

[0118] Even if this is not the case, if the mixing of the powders in the mixers Z3 and Z4 is insufficient and segregation occurs in the main drug or excipients contained in the mixed powder supplied to the feeder X of the molding machine, the amount of contained ingredients will vary from one molded product to another, resulting in defective products.

[0119] Therefore, the control device C of the system of this embodiment adjusts the supply amount of each powder by each measuring feeder Z1a, Z1b, Z1c, the rotation speed of the stirring shaft Z33, the stirring blade Z34, and the auxiliary blade Z35 of the vertical mixer Z3, the rotation speed of the stirring shaft Z42 and the stirring blade Z44 of the horizontal mixer Z4, and the rotation speed of the stirring shaft and the stirring blade of the vertical mixer Z5, based on the measured value of the mixing degree of the mixed powder by the first sensor S1, the second sensor S2, the third sensor S3, the fourth sensor S4, and / or the fifth sensor S5. The control device C may be a microcomputer system equipped with a processor, a memory, an auxiliary storage device, and an input / output interface, a programmable controller, or a general-purpose personal computer or workstation.

[0120] When the absolute value of the deviation between the amount or ratio of the main drug contained in the mixed powder, which is repeatedly measured by the first sensor S1, the second sensor S2, the third sensor S3, the fourth sensor S4 and / or the fifth sensor S5, and the target value exceeds a predetermined threshold (i.e., the ratio of the main drug is unreasonably small or unreasonably large) for a certain period of time or more, it is considered that the amount of powder supplied by at least one of the first measuring feeder Z1a, the second measuring feeder Z1b and the third measuring feeder Z1c is not appropriate. In this case, the control device C interrupts the weight feedback control by the measuring feeder Z1 itself and adjusts the rotation speed of the drive motor of each measuring feeder Z1 so that the amount or ratio of the main drug in the mixed powder measured by the first sensor S1, the second sensor S2, the third sensor S3, the fourth sensor S4 and / or the fifth sensor S5 converges to the vicinity of the target value. For example, if the measured amount or ratio of the main drug in the mixed powder is below the target value, the amount of the main drug discharged by the first metering feeder Z1a is increased, and / or the amount of excipients, etc. discharged by the second metering feeder Z1b and the amount of lubricant discharged by the third metering feeder Z1c are decreased. Conversely, if the measured amount or ratio of the main drug in the mixed powder is above the target value, the amount of the main drug discharged by the first metering feeder Z1a is decreased, and / or the amount of excipients, etc. discharged by the second metering feeder Z1b and the amount of lubricant discharged by the third metering feeder Z1c are increased.

[0121] Alternatively, when the absolute value of the deviation between the amount or ratio of the main agent contained in the mixed powder and its target value exceeds the threshold value for a certain period of time, the target value of the powder discharge amount commanded to each of Z1a, Z1b, and Z1c from the control device C may be changed in order to optimize the supply amount. For example, if the measured amount or ratio of the main agent in the mixed powder is below the target value, the target value of the discharge amount of the main agent to be given to the first measuring feeder Z1a is raised from the previous value, and / or the target value of the discharge amount of the excipient, etc. to be given to the second measuring feeder Z1b and the target value of the discharge amount of the lubricant to be given to the third measuring feeder Z1c are lowered from the previous values. Conversely, if the measured amount or ratio of the main agent in the mixed powder exceeds the target value, the target value of the discharge amount of the main agent to be given to the first metering feeder Z1a is lowered from its previous value, and / or the target value of the discharge amount of the lubricant, etc. to be given to the second metering feeder Z1b and the target value of the discharge amount of the lubricant to be given to the third metering feeder Z1c are raised from their previous values.

[0122] Although the absolute value of the deviation between the amount or ratio of the active ingredient contained in the mixed powder and the target value, which is repeatedly measured by the first sensor S1, the second sensor S2, the third sensor S3, the fourth sensor S4 and / or the fifth sensor S5, does not exceed the threshold value for a certain period of time or more, if the absolute value of the deviation exceeds the threshold value instantaneously or for a short period of time, it is considered that segregation has occurred in the mixed powder (of the active ingredient, excipients, etc. or lubricant) moving toward the feeder X of the molding machine, i.e., localized areas with high and low concentrations of the active ingredient have been formed. In this case, the control device C changes (increases or decreases) the rotation speed of the stirring shaft Z33 and thus the stirring blades Z34 and Z35 of the vertical mixer Z3 from the previous speed, changes (increases or decreases) the rotation speed of the stirring shaft Z42 and thus the stirring blades Z44 of the horizontal mixer Z4 from the previous speed, and / or changes (increases or decreases) the rotation speed of the stirring shaft and thus the stirring blades of the vertical mixer Z5 from the previous speed, thereby further increasing the degree of mixing of the powder.

[0123] In addition, even if the absolute value of the deviation between the amount or ratio of the main agent contained in the mixed powder and its target value exceeds the threshold value for a certain period of time or more, control may be performed to change the rotation speed of the stirring blades Z34 and Z35 of the vertical mixer Z3 from the previous speed, change the rotation speed of the stirring blade Z44 of the horizontal mixer Z4 from the previous speed, and / or change the rotation speed of the stirring blade of the vertical mixer Z5 from the previous speed.

[0124] As described above, if the amount of powder discharged by each measuring feeder Z1a, Z1b, Z1c is increased or decreased, or the rotation speed of the agitator shafts Z33, Z42 of each mixer Z3, Z4, Z5 is changed, the flow rate per unit time of the powder flowing through the buffer tank 19 or the inlet M5, which is the supply section that supplies the mixed powder to the powder measuring device M, may fluctuate.

[0125] If the rotor M2 of the powder measuring device M is constantly rotated at a constant rotation speed even if the flow rate of the mixed powder in the buffer tank 19 or the inlet M5 changes, the amount of the mixed powder passing through the powder measuring device M per unit time does not change because it is captured and transported by the moving part M21 of the rotor M2, and therefore the height of the upper surface L1 of the mixed powder accumulated inside the buffer tank 19 or the inlet M5 fluctuates. That is, when the supply flow rate of the powder per unit time to each moving part M21 of the rotor M2 increases more than the transport flow rate of the powder per unit time by the powder measuring device M, the height of the upper surface L1 of the powder inside the buffer tank 19 or the inlet M5 rises. Conversely, when the supply flow rate of the powder per unit time to each moving part M21 of the rotor M2 decreases more than the transport flow rate of the powder per unit time by the powder measuring device M, the height of the upper surface L1 of the powder inside the buffer tank 19 or the inlet M5 decreases.

[0126] If the height of the upper surface L1 of the powder changes significantly inside the buffer tank 19 or the inlet M5, which is located above the powder measuring device M and directly connected to the powder measuring device M, the amount of powder supplied to each moving part M21 of the rotor M2 will increase or decrease from an appropriate amount, causing the density of the powder captured in each moving part M21, in other words the density of the powder to be measured by the sensor S3, to fluctuate. This may result in a decrease in the accuracy of the measurement of the powder properties by the sensor S3.

[0127] In order to suppress such fluctuations in the powder supply amount or density, the control device C of this embodiment obtains the height of the upper surface L1 of the mixed powder inside the buffer tank 19 or the inlet M5 via the sensor S6, and adjusts the rotational speed of the motor M3 of the powder measuring device M and ultimately the rotating body M2 depending on the height of the upper surface.

[0128] As shown in FIG. 22, two capacitance-type level switches S61 and S62 are attached to the buffer tank 19 or the inlet M5 as the sensor S6. Each of the level switches S61 and S62 detects whether the height of the upper surface L1 of the powder stored inside the buffer tank 19 or the inlet M5 is higher or lower than the corresponding level switch S61 or S62. The control device C can determine through the level switches S61 and S62 whether the height of the upper surface L1 of the powder inside the buffer tank 19 or the inlet M5 is higher than the upper level switch S61, lower than the upper level switch S61 and higher than the lower level switch S62, or lower than the lower level switch S62. When the height of the upper surface L1 of the powder inside the buffer tank 19 or the inlet M5 is lower than the upper level switch S61 and higher than the lower level switch S62, it can be said that the height of the upper surface of the powder is within a desired target range.

[0129] When the top surface height of the powder inside the buffer tank 19 or the inlet M5 becomes equal to or exceeds the upper limit of the target range, i.e., when the top surface height becomes equal to or higher than the upper level switch S61, the control device C of this embodiment increases the rotation speed of the rotor M2 of the powder measuring device M compared to when the top surface height is within the target range. This increases the flow rate of the powder transferred per unit time by the powder measuring device M, and makes it possible to lower the top surface height of the powder inside the buffer tank 19 or the inlet M5 to within the target range.

[0130] Conversely, when the top surface height of the powder inside the buffer tank 19 or the inlet M5 falls below the lower limit of the target range, i.e., when the top surface height falls below the lower level switch S62, the rotation speed of the rotor M2 is slowed down compared to when the top surface height is within the target range. This reduces the flow rate of the powder transported per unit time by the powder measuring device M, and makes it possible to raise the top surface height of the powder inside the buffer tank 19 or the inlet M5 to within the target range.

[0131] In controlling the rotational speed of the rotating body M2, periods of increasing the rotational speed, i.e., periods during which the height of the top surface of the powder in the buffer tank 19 or inlet M5 decreases from the upper limit to the lower limit of the target range, and periods of decelerating the rotational speed, i.e., periods during which the height of the top surface of the powder inside the buffer tank 19 or inlet M5 increases from the lower limit to the upper limit of the target range, may be repeated alternately.

[0132] Under such circumstances, the control device C of this embodiment may control the rotation speed of the rotating body M2 so that a certain speed-up period and the next speed-up period are longer than the previous one, as shown in Fig. 24. For example, the rotation speed of the rotating body M2 in the next speed-up period is made slower than the rotation speed of the rotating body M2 in a certain speed-up period.

[0133] In addition, the control device C controls the rotation speed of the rotor M2 so that a deceleration period and the next deceleration period are longer than the former. For example, the rotation speed of the rotor M2 in a certain acceleration period is made faster than the rotation speed of the rotor M2 in the next acceleration period. As a result of such control, the height of the top surface of the powder in the buffer tank 19 or the inlet M5 can be stabilized and ultimately converged to a state where it does not reach the upper or lower limit of the target range.

[0134] In addition, as described above, if the amount of powder discharged by each measuring feeder Z1a, Z1b, Z1c is increased or decreased, the rotational speed of the agitator shafts Z33, Z42 of each mixing device Z3, Z4, Z5 is changed, or the rotational speed of the rotor M2 of the powder measuring device M is changed, the flow rate per unit time of the powder flowing through the powder supply pipe 191 that supplies the mixed powder to the feeder X of the molding machine may fluctuate.

[0135] If the turntable 3 and punches 5 and 6 of the molding machine are constantly rotated at a constant rotation speed even though the flow rate of the mixed powder toward the powder supply pipe 191 has changed, the consumption amount of the mixed powder per unit time in the molding machine does not change, and the height of the upper surface L2 of the mixed powder accumulated inside the powder supply pipe 191 fluctuates. That is, when the supply flow rate of the powder to the powder supply pipe 191 per unit time increases more than the consumption amount of the powder by the molding machine per unit time, the height of the upper surface L2 of the powder inside the powder supply pipe 191 rises. Conversely, when the supply flow rate of the powder to the powder supply pipe 191 per unit time decreases more than the consumption amount of the powder by the molding machine per unit time, the height of the upper surface L2 of the powder inside the powder supply pipe 191 decreases.

[0136] Furthermore, if the height of the upper surface L2 of the powder inside the powder supply pipe 191, which is located above the feeder X and directly connected to the feeder X, fluctuates significantly, the amount of powder filled into the die hole 4 from the feeder X will increase or decrease more than the appropriate amount, creating the risk of the molded product formed in the die hole 4 being a defective product.

[0137] In order to suppress such fluctuations in the amount of powder filled, the control device C of this embodiment obtains the height of the upper surface L2 of the mixed powder inside the powder supply pipe 191 via the sensor S7, and adjusts the rotational speed of the motor 8 of the molding machine, as well as the turntable 3 and pestles 5 and 6, depending on the height of the upper surface.

[0138] As shown in FIG. 23, the powder supply pipe 191 is provided with two capacitance-type level switches S71 and S72 as the sensor S7. Each of the level switches S71 and S72 detects whether the height of the upper surface L2 of the powder accumulated inside the powder supply pipe 191 is higher or lower than the corresponding level switch S71 or S72. The control device C can determine, via the level switches S71 and S72, whether the height of the upper surface L2 of the powder inside the supply pipe 191 is higher than the upper level switch S71, lower than the upper level switch S71 and higher than the lower level switch S72, or lower than the lower level switch S72. When the height of the upper surface L2 of the powder inside the supply pipe 191 is lower than the upper level switch S71 and higher than the lower level switch S72, it can be said that the height of the upper surface of the powder is within a desired target range.

[0139] When the top surface height of the powder inside the powder supply pipe 191 becomes equal to or higher than the upper limit of the target range, i.e., when the top surface height becomes equal to or higher than the upper level switch S71, the control device C of this embodiment increases the rotation speed of the turntable 3 and punches 5, 6 of the molding machine compared to when the top surface height is within the target range. This increases the amount of powder consumed by the molding machine per unit time, and makes it possible to lower the top surface height of the powder inside the powder supply pipe 191 to within the target range.

[0140] Conversely, when the top surface height of the powder inside the powder supply pipe 191 falls below the lower limit of the target range, i.e., when the top surface height falls below the lower level switch S71, the rotation speed of the turntable 3 and punches 5, 6 of the molding machine is slowed down compared to when the top surface height is within the target range. This reduces the amount of powder consumed per unit time by the molding machine, and the top surface height of the powder inside the powder supply pipe 191 can be raised to within the target range.

[0141] In controlling the rotational speed of the turntable 3 and pestles 5, 6 of the molding machine, periods of increasing the rotational speed, i.e., periods during which the height of the top surface of the powder in the powder supply pipe 191 decreases from the upper limit to the lower limit of the target range, and periods of decelerating the rotational speed, i.e., periods during which the height of the top surface of the powder inside the supply pipe 191 increases from the lower limit to the upper limit of the target range, may be repeated alternately.

[0142] Under such circumstances, the control device C of this embodiment controls the rotation speeds of the turntable 3 and punches 5, 6 so that a certain speed-up period and the next speed-up period are longer than the former, as shown in Fig. 24. For example, the rotation speeds of the turntable 3 and punches 5, 6 in a certain speed-up period are made slower than the rotation speeds of the turntable 3 and punches 5, 6 in the next speed-up period.

[0143] Furthermore, the control device C controls the rotation speeds of the turntable 3 and the punches 5, 6 so that a deceleration period and the next deceleration period are longer than the former. For example, the rotation speeds of the turntable 3 and the punches 5, 6 in a certain acceleration period are made faster than the rotation speeds of the turntable 3 and the punches 5, 6 in the next acceleration period. As a result of such control, it is possible to ultimately converge the height of the top surface of the powder in the powder supply pipe 191 to a stable state that does not reach either the upper or lower limit of the target range.

[0144] As already described, the powder removal unit M4 of the powder mixing and supplying device Z, which sends out powder toward the powder supplying pipe 191, may remove defective powder without supplying it to the powder supplying pipe 191. When powder is removed in the powder removal unit M4, the amount of powder sent out toward the powder supplying pipe 191 per unit time decreases, which may cause a concern that the height of the upper surface of the powder inside the powder supplying pipe 191 may decrease.

[0145] Therefore, even if the height of the top surface of the powder is lower than the upper level switch S71 and higher than the lower level switch S72, when the powder removal unit M4 removes the powder, the control device C of this embodiment performs feedforward control to slow down the rotation speed of the turntable 3 and punches 5, 6 of the molding machine compared to when the powder removal unit M4 does not remove the powder. Specifically, when the control device C receives a signal indicating that the driving device M42 is operated in the powder removal unit M4 and the powder captured in the moving part M21 of the rotor M2 has been dropped into the removal hole M12, the control device C slows down the rotation speed of the turntable 3 and punches 5, 6 compared to before. The rotation speed of the turntable 3 and punches 5, 6 at this time is a value obtained by multiplying the rotation speed immediately before the deceleration by a coefficient (greater than 0) and smaller than 1.

[0146] In addition, when executing control to decelerate the rotational speed of the turntable 3 and punches 5, 6 of the molding machine in response to the removal of powder by the powder removal section M4, it is preferable to change the rate of deceleration depending on the rotational speed immediately before the deceleration.

[0147] In a situation where the rotation speed of the turntable 3 and the punches 5 and 6 immediately before the deceleration is relatively fast, the flow rate of the powder per unit time supplied from the powder mixing supply device Z to the powder supply pipe 191 and thus to the feedshoe X is originally large. On the other hand, the amount of powder removed by the powder removal unit M4 at one opportunity is equal to the amount of powder captured by one moving part M21 of the rotor M2, which is basically a constant amount. Therefore, when the removal of powder occurs under a situation where the rotation speed of the turntable 3 and the punches 5 and 6 is relatively fast, the rate of decrease in the amount of powder per unit time supplied from the powder mixing supply device Z to the powder supply pipe 191 is small, and the impact is relatively minor. Therefore, the rate of deceleration of the rotation speed of the turntable 3 and the punches 5 and 6 of the molding machine when the removal of powder occurs may be small, and the coefficient multiplied by the rotation speed immediately before the deceleration is set to a larger value.

[0148] On the other hand, when the rotation speed of the turntable 3 and the punches 5 and 6 immediately before the deceleration is relatively slow, the flow rate of the powder per unit time supplied from the powder mixing supply device Z to the powder supply pipe 191 is originally small. On the other hand, the amount of powder removed by the powder removal unit M4 at one opportunity is basically constant, and when the removal of powder occurs under the condition that the rotation speed of the turntable 3 and the punches 5 and 6 is relatively slow, the rate of decrease in the amount of powder per unit time supplied from the powder mixing supply device Z to the powder supply pipe 191 is large, and the impact is relatively serious. Therefore, it is necessary to set the rate of deceleration of the rotation speed of the turntable 3 and the punches 5 and 6 of the molding machine when the removal of powder occurs to be large, and the coefficient multiplied by the rotation speed immediately before the deceleration is set to be small.

[0149] The powder measuring device M of this embodiment is combined with a powder compression molding machine to form a powder compression molding system. The powder compression molding machine is a rotary type that rotates a turntable 3 equipped with a table 31 provided with a die hole 4 and punch holding parts 32, 33 that hold punches 5, 6 arranged above and below the die hole 4 so that they can slide up and down, together with the punches 5, 6, and fills the die hole 4 with powder from a filling device X arranged directly above the table 31, thereby compressing the powder filled in the die hole 4 with the punches 5, 6 to form a molded product, and is equipped with a control device C that adjusts the rotation speed of the turntable 3 and the punches 5, 6 so that the top surface height of the powder in the supply pipe 191, which is directly connected to the filling device X and through which the powder discharged from the discharge part M6 of the powder measuring device M is supplied, falls within a certain target range.

[0150] Specifically, when the height of the top surface of the powder inside the supply pipe 191 is equal to or higher than the upper limit of the target range, the rotation speed of the turntable 3 and the pestles 5, 6 is increased compared to when this is not the case, and when the height of the top surface of the powder inside the supply pipe 191 is equal to or lower than the lower limit of the target range, the rotation speed of the turntable 3 and the pestles 5, 6 is decreased compared to when this is not the case.

[0151] When the rotation speed of the turntable 3 and the punches 5, 6 of the rotary powder compression molding machine is increased, the amount of powder consumed per unit time in the molding machine increases. Conversely, when the rotation speed of the turntable 3 and the punches 5, 6 is decreased, the amount of powder consumed per unit time decreases. When the amount of powder consumed per unit time is increased, the height of the top surface of the powder inside the supply pipe 191 directly connected to the filling device X decreases, and when the amount of powder consumed per unit time is decreased, the height of the top surface of the powder inside the supply pipe 191 increases.

[0152] In this embodiment, the rotation speed of the turntable 3 and the pestles 5 and 6 of the rotary type powder compression molding machine is controlled to constantly converge the top surface height of the powder inside the supply pipe 191 within a certain target range. That is, before the powder runs out in the filling device X, the rotation speed of the turntable 3 is lowered to reduce the powder consumption, and before the powder overflows, the rotation speed of the turntable 3 is increased to increase the powder consumption. This makes it possible to prevent a situation in which the operation of the molding machine must be stopped.

[0153] Maintaining a constant upper surface height of the powder inside the supply pipe 191 (or inside the filling device X), in other words, maintaining a constant pressure of the powder inside the filling device X, is also effective for constantly filling a constant amount of powder from the filling device X into the die hole 4. If the amount of powder filled into the die hole 4 is more or less than the appropriate amount, the hardness, density, and weight of the finished product will deviate from the desired values. Therefore, it is necessary to minimize the variation in the amount of powder filled into the die hole 4. If the amount of powder filled into the die hole 4 can be precisely controlled, the quality of the resulting molded product can be maintained high.

[0154] One of the reasons why the height of the upper surface of the powder inside the supply pipe 191 directly connected to the filling device X of the molding machine (or inside the filling device X) can be significantly reduced is when the removal unit M4 of the powder measuring device M that sends out the powder toward the supply pipe 191 removes defective powder without supplying it to the supply pipe 191. In such a case, it is also preferable to reduce the rotation speed of the turntable 3 and the punches 5 and 6 compared to other cases.

[0155] In this embodiment, the height of the upper surface L1 of the powder inside the supply unit 19, M5 is detected using two level switches S61, S62, and the height of the upper surface L2 of the powder inside the supply pipe 191 is detected using two level switches S71, S72, but the sensors S6, S7 for detecting the heights of the powder upper surfaces L1, L2 are not limited to such level switches S61, S62, S71, S72. For example, a contact type level meter that directly contacts the powder accumulated inside the supply unit 19, M5 or the supply pipe 191 to measure the height of the upper surfaces L1, L2, or a non-contact type level meter that measures the height of the powder upper surfaces L1, L2 by emitting ultrasonic waves or electromagnetic waves toward the powder upper surfaces L1, L2 and receiving the reflected waves can be used as the sensors S6, S7. Alternatively, it is also possible to photograph the inside of the supply unit 19, M5 or supply pipe 191 with a camera sensor, and analyze the obtained image in the control device C to obtain the heights of the upper surfaces L1, L2 of the powder.

[0156] In this embodiment, the rotation speeds of the turntable 3 and punches 5, 6 of the molding machine are adjusted so that the height of the upper surface L2 of the powder inside the supply pipe 191 directly connected to the filling device X falls within a certain target range. Alternatively, (particularly when the filling device X is an open feeder) a level switch or level gauge for obtaining the height of the upper surface of the powder inside the filling device X can be attached to the filling device X, and the rotation speeds of the turntable 3 and punches 5, 6 of the molding machine can be adjusted so that the height of the upper surface of the powder inside the filling device X falls within a certain target range.

[0157] In this case, when the height of the top surface of the powder inside the filling device X is equal to or higher than the upper limit of the target range, the rotation speed of the turntable 3 and the pestles 5, 6 is increased compared to when this is not the case, whereas when the height of the top surface of the powder inside the filling device X is equal to or lower than the lower limit of the target range, the rotation speed of the turntable 3 and the pestles 5, 6 is decreased compared to when this is not the case.

[0158] When the control device C provides a period in which it increases the rotational speed of the turntable 3 and the punches 5, 6 so that the height of the top surface of the powder inside the filling device X moves from a state where it is above the upper limit of the target range toward the lower limit of the target range, and a period in which it decelerates the rotational speed of the turntable 3 and the punches 5, 6 so that the height of the top surface of the powder inside the filling device X moves from a state where it is below the lower limit of the target range toward the upper limit of the target range, it is preferable to control the rotational speed of the turntable 3 and the punches 5, 6 so that a certain acceleration period and the next acceleration period are longer than the former, and to control the rotational speed of the turntable 3 and the punches 5, 6 so that a certain deceleration period and the next deceleration period are longer than the former.

[0159] The control device C may perform feedback control to finely adjust the rotation speed of the rotating body M2 of the powder measuring device M or the rotating disk 3 and the pestles 5 and 6 of the molding machine according to the deviation between the height of the upper surface L1, L2 of the powder detected via the sensors S6 and S7 and the target value (which may be the median value of the target range or the upper or lower limit of the target range) so that the height of the upper surface L1, L2 of the powder accumulated inside the supply unit 19, M5, or inside the supply pipe 191 or the filling device X falls within a target range. When the upper surface height of the powder is higher than the target value, the rotation speed is reduced as the absolute value of the deviation between the upper surface height and the target value increases. On the other hand, when the upper surface height of the powder is lower than the target value, the rotation speed is increased as the absolute value of the deviation between the upper surface height and the target value increases. In this case, it is arbitrary how to design the controller of the control system embodied by the control device C. As a design method of the control controller, various methods such as PID control, model predictive control, learning control, and the like can be adopted.

[0160] In order to keep the height of the upper surfaces L1, L2 of the accumulated powder inside the supply unit 19, M5, or inside the supply pipe 191 or the filling device X within a target range, the control device C may measure the flow rate of the powder supplied to the supply unit 19, M5 or the supply pipe 191 via a flow meter, and when the flow rate is high, may perform control to increase the rotational speed of the rotating body M2 or the turntable 3 and the pestles 5, 6 compared to when the flow rate is low.

[0161] Furthermore, in order to keep the height of the upper surfaces L1, L2 of the accumulated powder inside the supply unit 19, M5, or inside the supply pipe 191 or the filling device X within a target range, the control device C may measure the pressure (from the accumulated powder) inside the supply unit 19, M5, or inside the supply pipe 191 or the filling device X via a pressure gauge, and when the internal pressure is high, may perform control to increase the rotational speed of the rotating body M2 or the turntable 3 and the pestles 5, 6 compared to when the internal pressure is low.

[0162] In this embodiment, the powder measuring device M is configured to measure the properties of a mixed powder containing two or more powders and then send it to an equipment (rotary powder compression molding machine) that performs subsequent processing using the mixed powder.In order to measure the properties of the mixed powder while the mixed powder is being sent to the equipment, the powder measuring device M includes a sensor probe S3 that receives reflected light reflected from the mixed powder passing nearby or transmitted light that passes through the mixed powder, and standard samples M23, M74 with known properties that are arranged to face the sensor probe S3 when the mixed powder is not present in the vicinity of the sensor probe S3 while the mixed powder is being sent to the equipment and receive the reflected light reflected from the sensor probe S3 or the transmitted light that passes through the sensor probe S3.

[0163] According to this embodiment, it is possible to check or calibrate the characteristics at any time while continuing the operation of the powder mixing and supplying device Z including the powder measuring device M and the molding machine, without removing the sensor probe S3 from the measuring device M. Since the accuracy of the analysis of the properties of the mixed powder by the measuring device M (via the sensor S3) can be kept high, deterioration of the quality of the mixed powder supplied by the powder mixing and supplying device Z and further deterioration of the quality of the molded product produced by the molding machine can be prevented.

[0164] In this embodiment, the standard samples M23, M74 are provided at a portion (particularly, the blade M22) facing the sensor probe S3 of the moving members M2, M72 (particularly, the rotor M2 that captures and transfers the mixed powder to be sent to the device) that move so as to pass near the sensor probe S3, so that the configuration of the powder measuring device M is compact and not bulky. Moreover, the calibration process can be performed while continuing the transfer of the mixed powder (particularly, when the blade M22 passes near or stays near the sensor probe S3).

[0165] In addition, if the cleaning members M26, M73 that contact and wipe the sensor probe S3 are provided on the moving members M2, M72 at the portions (particularly the blade M22) facing the sensor probe S3, the sensor probe S3 can be cleaned while the mixed powder is being transferred, and the input / output characteristics of the sensor probe S3 can be maintained appropriately for a long period of time.

[0166] It is also preferable to provide a nozzle M24 for ejecting gas to blow off and remove dust or dirt adhering to the sensor probe S3.

[0167] The present invention is not limited to the embodiment described above in detail, and the specific configuration of each part can be modified without departing from the spirit of the present invention. [Explanation of symbols]

[0168] M…Powder measuring device M2: Moving part (rotating body) M22: Part that faces the sensor probe (blade) M23: Standard sample M24…Nozzle M26…Cleaning material S3…Sensor probe M7…Cleaning mechanism M72…moving parts M73…Cleaning material M74…Standard sample Z…Powder mixing supply device

Claims

1. The purpose of this device is to measure the properties of a mixed powder obtained by mixing two or more powders, and then to send the mixed powder to an apparatus that performs a post-process using the mixed powder, A rotating body having a plurality of moving parts, each of which captures and transports a mixing member during operation of delivering the mixed powder toward the device; a sensor probe for receiving reflected light or transmitted light that is transmitted through the mixed powder passing nearby the sensor probe, in order to measure properties of the mixed powder captured at each moving portion of the rotating body during operation of sending the mixed powder toward the device; The sensor probe is provided at a portion separating a certain moving portion of the rotating body from another moving portion adjacent thereto, and is arranged so that the sensor probe receives reflected light or transmitted light that is incident on the sensor probe and is reflected by the sensor probe when the mixed powder is not present in the vicinity of the sensor probe during the operation of feeding the mixed powder toward the device. A powder measuring device comprising:

2. A powder measuring device as described in claim 1, wherein a cleaning material is provided at a portion that separates a certain moving part in the rotating body from another moving part adjacent to it and faces the sensor probe, for contacting and wiping the sensor probe.

3. A powder measuring device as described in claim 1 or 2, further comprising a nozzle for ejecting gas to blow away and remove dust or dirt adhering to the sensor probe.

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