Powdery-material feeding device and powdery-material feeding method

A powdery-material feeding device is configured to feed a powdery material to a compression-molding machine configured to obtain a molded product by filling a die bore with the powdery material and to compress the powdery material with punches. The powdery-material feeding device includes a detector configured to detect a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine, and a controller configured to control to remove the powdery material mixedly containing the biologically-originated foreign matter detected by the detector to avoid feeding of the powdery material mixedly containing the biologically-originated foreign matter to the compression-molding machine, or to control to stop the feeding of the powdery material to the compression-molding machine.

BACKGROUND

There has been known a rotary compression-molding machine including a table of a turret having die bores, an upper punch, and a lower punch slidably retained above and below each of the die bores, and configured to horizontally rotate the die bores and the punches together to compression mold a powdery material filled in the die bores when the paired upper and lower punches pass between an upper roll and a lower roll (see, for example, JP 2015-221458 A).

In a case where the compression-molding machine produces a molded product mixedly containing a metal piece, the metal piece can be sensed by checking the molded product with a metal detector. The molded product mixedly containing the metal piece can be distinguished and removed from normal molded products.

In another case where the powdery material fed to the compression-molding machine mixedly contains a biologically-originated foreign matter like a human hair or a bug, and molded products are produced from the powdery material, it is difficult to find a molded product containing such a biologically-originated foreign matter by checking completed molded products.

SUMMARY OF THE INVENTION

It is an exemplary object of the present invention to prevent the compression-molding machine from producing a molded product that mixedly contains a biologically-originated foreign matter.

The invention exemplarily provides a powdery-material feeding device configured to feed a powdery material to a compression-molding machine configured to obtain a molded product by filling a die bore with the powdery material and to compress the powdery material with punches. The powdery-material feeding device includes a detector configured to detect a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine, and a controller configured to control to remove the powdery material mixedly containing the biologically-originated foreign matter detected by the detector to avoid feeding of the powdery material mixedly containing the foreign matter to the compression-molding machine, or to control to stop the feeding of the powdery material to the compression-molding machine. This configuration prevents feeding, to the molding machine, of the powdery material mixedly containing the biologically-originated foreign matter.

The powdery-material feeding device is further configured to feed the compression-molding machine with mixed powdery materials containing at least two types of powdery materials. The powdery-material feeding device includes a detector configured to measure a mixing degree of the mixed powdery materials to be fed to the compression-molding machine. When the mixing degree of the mixed powdery materials detected by the detector is out of a predetermined range, the controller controls to remove the mixed powdery materials to avoid the feeding to the compression-molding machine or controls to stop the feeding of the mixed powdery materials to the compression-molding machine. This configuration prevents the feeding, to the molding machine, of the mixed powdery materials having a mixing degree out of a normal range as well as a biologically-originated foreign matter, to keep high quality of molded products.

When the powdery-material feeding device removes a powdery material mixedly containing foreign matter or powdery materials having an abnormal mixing degree, the powdery material fed from the powdery-material feeding device to the compression-molding machine can have a temporarily decreased flow rate per unit time. The compression-molding machine includes a rotary compression-molding machine and is configured to rotate a turret including a table having a die bore, and punch retaining portions vertically slidably retaining punches disposed above and below the die bore, along with the punches, and fill the die bore with a powdery material from a filling device disposed just above the table, to compress the powdery material filled in the die bore with the punches and to obtain a molded product. The controller controls to adjust a rotational speed of the turret and the punches of the rotary compression-molding machine to allow the powdery material in a feed pipe directly connected to the filling device and is further configured to feed the powdery material toward the filling device or in the filling device to have an upper surface level kept within a constant target range. This configuration achieves adjustment of an amount per unit time of a powdery material used by the molding machine in accordance with the flow rate of the powdery material fed from the powdery-material feeding device to the filling device.

Specifically, an increase in a rotational speed of the turret and the punches leads to an increase in an amount of the used powdery material per unit time, whereas a decrease in a rotational speed of the turret and the punches leads to a decrease in an amount of the used powdery material per unit time. An increase in an amount of the used powdery material per unit time leads to a decrease in an upper surface level of the powdery material in the feed pipe directly connected to the filling device or in the filling device, whereas a decrease in an amount of the used powdery material per unit time leads to an increase in an upper surface level of the powdery material in the feed pipe or in the filling device. When the upper surface level of the powdery material in the feed pipe or in the filling device is kept within a constant target range by adjustment of the rotational speed of the turret and the punches of the rotary compression-molding machine, the powdery material in the filling device constantly keeps pressure, and the filling device can keep filling the die bores with a constant amount of the powdery material. This leads to suppression of variation in weight, size, tableting pressure, and the like of the produced molded products.

The exemplary invention provides a method of feeding a powdery material to a compression-molding machine configured to obtain a molded product by filling a die bore with the powdery material and to compress the powdery material with punches. The powdery-material feeding method includes detecting a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine, and controlling to remove the powdery material mixedly containing the biologically-originated foreign matter detected during the detection to avoid feeding of the powdery material mixedly containing the foreign matter to the compression-molding machine or controlling to stop the feeding of the powdery material to the compression-molding machine.

The powdery-material feeding method is applied to feed the compression-molding machine with mixed powdery materials containing at least two types of powdery materials. The method further includes detecting by measuring a mixing degree of the mixed powdery materials to be fed to the compression-molding machine, and controlling to remove the mixed powdery materials to avoid feeding to the compression-molding machine or controlling to stop the feeding of the mixed powdery materials to the compression-molding machine when the mixing degree of the mixed powdery materials measured during the detection is out of a predetermined range.

The powdery-material feeding method is applied to the rotary compression-molding machine configured to rotate a turret including a table having a die bore, and punch retaining portions vertically slidably retaining punches disposed above and below the die bore, along with the punches, and fill the die bore with a powdery material from a filling device disposed just above the table, to compress the powdery material filled in the die bore with the punches and to obtain a molded product. The powdery-material feeding method further includes controlling to adjust a rotational speed of the turret and the punches of the rotary compression-molding machine to allow the powdery material in a feed pipe directly connected to the filling device and configured to feed the powdery material toward the filling device or in the filling device to have an upper surface level being kept within a constant target range.

A powdery material is an aggregate of minute solids and conceptually includes an aggregate of particles such as so-called granules and an aggregate of powder smaller than such particles. Examples of the powdery material include a powdery material containing a principal agent, an excipient, a binder, a disintegrant, a stabilizer, and a preservative. The powdery material according to the exemplary invention also includes a mixture of two or more types of powdery materials, and a powdery material containing the principal agent mixed with a lubricant such as magnesium stearate.

The exemplary invention may prevent the compression-molding machine from producing a molded product that mixedly contains a biologically-originated foreign matter.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

An exemplary embodiment of the exemplary invention will now be described with reference to the drawings. Initially described is an overview of an entire rotary compression-molding machine (hereinafter, referred to as the “molding machine”) according to the exemplary embodiment. As shown exemplarily inFIG. 1, the molding machine includes a frame1accommodating an upright shaft2that functions as a rotary shaft, and a turret3that is attached to a connection portion21disposed at the top of the upright shaft2. A worm wheel7is attached to the lower end of the upright shaft2. The worm wheel7meshes with a worm gear10. The worm gear10is fixed to a gear shaft9that is driven by a motor8. Drive power outputted from the motor8is transmitted to the gear shaft9by way of a belt11, so as to rotate the upright shaft2by way of the worm gear10and the worm wheel7. Rotation of the upright shaft2causes rotation of the turret3and punches5and6.

The turret3horizontally rotates about the upright shaft2, and more specifically, spins. The turret3includes a table (e.g., die disc)31, an upper punch retaining portion32, and a lower punch retaining portion33. As shown exemplarily inFIG. 2, the table31has a substantially circular disc shape, and has a plurality of die bores4that is disposed in an outer circumferential portion and is aligned in a direction of rotation at predetermined intervals. Each of the die bores4vertically penetrates the table31. The table31can alternatively include a plurality of divided plates. Instead of the die bores4formed directly in the table31, a die member including the die bores4can be attached to the table31.

The upper and lower punches5and6are disposed above and below each of the die bores4and are individually vertically slidable along the die bores4. The upper punch retaining portion32retains upper punch trunks52while the lower punch retaining portion33retains lower punch trunks62. The upper punches5each have a tip53that enters and exits corresponding one of the die bores4. The lower punches6each have a tip63that is kept inserted in corresponding one of the die bores4. The upper and lower punches5and6horizontally rotate about the upright shaft2along with the turret3, more specifically, revolve.

As shown exemplarily inFIG. 17, the gear shaft9has an end connected, by way of a reduction gear24, with a rotary encoder23configured to detect a rotation angle and a rotational speed of the gear shaft9as well as (the table31, the die bores4, and the punches5and6of) the turret3. The rotary encoder23outputs a pulse signal every time the gear shaft9rotates by a predetermined angle. Upon receipt of a train of the pulse signals, a controller C (shown exemplarily inFIG. 16) included in a compression-molding machine system according to the exemplary embodiment is configured to detect the rotation angle and the rotational speed of the turret3(i.e., find a current position of each of the die bores4on the table31). The reduction gear24reduces the rotational speed of the gear shaft9to be adapted to an input speed of the rotary encoder23and transmits the reduced rotational speed to the rotary encoder23.

A feeder X functioning as a filling device is provided to fill the die bores4of the turret3with a powdery material. The feeder X can be a gravity feeder configured to simply drop a powdery material into the die bores4or an agitated feeder configured to drop, into the die bores4, a powdery material being agitated by rotating an incorporated agitating rotor. The exemplary embodiment assumes that the feeder X is the agitated feeder. The feeder X is positioned on the outer circumferential portion of the rotating table31, particularly, just above a revolution orbit of the die bores4. The powdery material is fed to the feeder X from a powdery-material feed pipe191(shown exemplarily inFIGS. 10 and 11) functioning as a discharger M6of a powdery material mixing degree measurement device M to be described later. A buffer tank19is provided to feed a feeding unit M5of the powdery material mixing degree measurement device M with the powdery material.

As shown exemplarily inFIG. 3, a preliminary compression upper roll12, a preliminary compression lower roll13, a substantial compression upper roll14, and a substantial compression lower roll15are disposed on orbits of the upper and lower punches5and6that revolve about the upright shaft2. The preliminary compression upper roll12and the preliminary compression lower roll13, as well as the substantial compression upper roll14and the substantial compression lower roll15, are respectively paired in the vertical direction so as to sandwich the upper and lower punches5and6. The preliminary compression upper roll12and the substantial compression upper roll14each press a head51of each of the upper punches5, and the preliminary compression lower roll13and the substantial compression lower roll15each press a head61of each of the lower punches6. The preliminary compression upper roll12and the preliminary compression lower roll13, as well as the substantial compression upper roll14and the substantial compression lower roll15, bias the upper and lower punches5and6to come closer to each other, so that end surfaces of the tips53and63compress from above and below the powdery material filled in the die bores4.

The upper and lower punches5and6have the heads51and61pressed by the rolls12,13,14, and15, and the trunks52and62smaller in diameter than the heads51and61, respectively. The upper punch retaining portion32of the turret3vertically slidably retains the trunks52of the upper punches5, whereas the lower punch retaining portion33vertically slidably retains the trunks62of the lower punches6. The tips53and63of the trunks52and62are thinner than the remaining portions and are substantially equal in diameter to an inner diameter of the die bores4so as to be inserted to the die bores4. The punches5and6revolve to cause the rolls12,13,14, and15to come closer to the heads51and61of the punches5and6. The rolls12,13,14, and15come into contact with the heads51and61so as to step thereonto. The rolls12,13,14, and15further press the upper punches5downward and press the lower punches6upward. While the rolls12,13,14, and15are in contact with flat surfaces of the punches5and6, the punches5and6keep applying required pressure to the powdery material in the die bores4.

As shown exemplarily inFIG. 18, the upper rolls12and14of the molding machine each have a load cell121configured to detect pressure applied to compress the powdery material in the die bore4by the rolls12,13,14, and15via the punches5and6. The controller C, according to the exemplary embodiment receives signals transmitted from the load cells121disposed at the rolls12,13,14, and15to find a magnitude of the pressure applied to compress the powdery material by the preliminary compression rolls12and13(e.g., a preliminary compression pressure) and a magnitude of the pressure applied to compress the powdery material by the substantial compression rolls14and15(e.g., substantial compression pressure). The signals outputted from the load cells121form a pulse signal train having a peak when each of the pairs of punches5and6compresses the powdery material in a corresponding one of the die bores4with a maximum pressure. The controller C thus counts the number of pulse trains to find the number of molded products produced by the molding machine per unit time.

A molded-product collector is disposed downstream, in the direction of rotation of the turret3and the punches5and6, of the position where the substantial compression upper roll14and the substantial compression lower roll15apply pressure. This molded-product collector includes a guide member17configured to guide a molded product pushed out of each of the die bores4. The guide member17extends to have a proximal end located at a molded-product collecting position18and a distal end located closer to the center of the table31than a rotation locus of the die bores4. The molded product pushed out of each of the die bores4by the corresponding lower punch6comes into contact with the guide member17and moves toward the molded-product collecting position18.

A molded-product production process conducted by the molding machine will be described roughly. As shown exemplarily inFIG. 3, the lower punch6initially descends and the feeder X fills, with a powdery material (e.g., mixed powdery materials), the die bore4into which the tip63of the lower punch6is inserted. The lower punch6subsequently ascends such that the die bore4is filled with a required amount of the powdery material (e.g., mixed powdery materials), and the powdery material overflowing the die bore4is leveled.

The upper punch5then descends, and the preliminary compression upper roll12and the preliminary compression lower roll13press the head51of the upper punch5and the head61of the lower punch6, such that the tips53and63of the punches5and6preliminarily compress the powdery material in the die bore4. The substantial compression upper roll14and the substantial compression lower roll15subsequently press the head51of the upper punch5and the head61of the lower punch6, such that the tips53and63of the punches5and6substantially compress the powdery material in the die bore4.

The lower punch6then ascends until the upper end surface of the tip63of the lower punch6substantially reaches the level of the upper end of the die bore4(i.e., the top surface of the table31) and pushes a molded product out of the die bore4onto the surface of the turret3. The molded product pushed out of the die bore4is brought into contact with the guide member17by rotation of the turret3, and moves along the guide member17to the molded-product collecting position18.

The molded-product collector of the molding machine according to the exemplary embodiment has a molded-product removal mechanism W configured to select a specific molded product such as a sampled product or a defective product from among molded products collected at the molded-product collecting position18. Specifically, the guide member17is provided therein with an air passage16for a pressurized air flow, and the air passage16has a distal end functioning as an air spray nozzle16aopened outward in the radial direction of the turret3. A flow passage20connects an air feed source (not shown) such as a pump configured to feed pressurized air and the air passage16, and a control valve22is disposed on the flow passage20to open and close the flow passage20. Examples of the control valve22can include an electromagnetic solenoid configured to open in accordance with a control signal transmitted from the controller C.

If the control valve22is opened when the specific molded product pushed out of the die bore4passes by the air spray nozzle16abefore contacting the guide member17, then the air spray nozzle16asprays pressurized air fed from the air feed source through the flow passage20and the air passage16in the guide member17. The sprayed air blows the specific molded product outward from the table31. The blown molded product will not reach the molded-product collecting position18ahead of the guide member17. As described above, the molded-product removal mechanism W in the molding machine according to the exemplary embodiment includes the passages16and20for air fed from the air feed source, the air spray nozzle16a, and the control valve22.

The molded-product removal mechanism W is also configured to sample a tableted molded product.

Described below is a powdery-material feeding device Z configured to deliver a powdery material toward the feed pipe191directly connected to the feeder X of the molding machine. As shown exemplarily inFIGS. 4 and 5, the powdery-material feeding device Z according to the exemplary embodiment includes three measuring feeders Z1(Z1a, Z1b, and Z1c). The number of measuring feeders Z1changes depending on the number of types of powdery materials to be mixed. The powdery-material feeding device Z can include two, or four or more measuring feeders Z1with no particular limitation in the number thereof.

The first to third measuring feeders Z1ato Z1caccording to the exemplary embodiment measure and feed different types of powdery materials. These measuring feeders Z1ato Z1ccan alternatively measure and feed a single type of a powdery material. In the exemplary embodiment, the first measuring feeder Z1a, the second measuring feeder Z1b, and the third measuring feeder Z1cmeasure and feed a principal agent, a powdery material of an excipient like lactose, or the like, and a lubricant, respectively.

As shown exemplarily inFIGS. 4 and 5, the powdery-material feeding device Z includes the first measuring feeder Z1a, the second measuring feeder Z1b, a vertical mixer Z3(e.g., a first mixer), a first connecting pipe Z2aconnecting the measuring feeders Z1(Z1aand Z1b) and the vertical mixer Z3, a horizontal mixer Z4(e.g., a second mixer), a second connecting pipe Z2bconnecting the vertical mixer Z3and the horizontal mixer Z4, a third connecting pipe Z2cconnecting the third measuring feeder Z1cand the horizontal mixer Z4, and a fourth connecting pipe Z2dconnecting the horizontal mixer Z4and the buffer tank19.FIG. 4is a perspective view showing a state where the powdery-material feeding device Z is attached to the molding machine.FIG. 5is a side view of the powdery-material feeding device Z. The measuring feeders (e.g., Z1a, Z1b, and Z1c) can be modified in terms of their disposition, shapes, and the like, and are not limited to the aspect shown exemplarily inFIGS. 4 and 5.

The first measuring feeder Z1aand the second measuring feeder Z1bmeasure the powdery materials, namely, the principal agent and the excipient or the like, respectively, and simultaneously feed the first connecting pipe Z2awith the powdery materials. The third measuring feeder Z1cmeasures the powdery material, namely, the lubricant, and simultaneously feeds the third connecting pipe Z2cwith the powdery material. These measuring feeders Z1are configured in accordance with the known loss in weight system (e.g., a loss integrated value system), and each conduct feedback control of causing a gravimetric sensor to constantly measure weight of a powdery material discharged from the feeder Z1, comparing to find whether or not the weight transitions to achieve a set target discharge flow rate, and increasing or decreasing a discharge rate of the feeder Z1to reduce a difference between. Measuring the powdery materials to be fed and simultaneously feeding the connecting pipes Z2aand Z2cwith the powdery materials stabilizes contents of the principal agent and the like in a molded product.

As described earlier, the first connecting pipe Z2aconnects the first measuring feeder Z1aand the second measuring feeder Z1bto the vertical mixer Z3, to feed the vertical mixer Z3with the principal agent discharged from the first measuring feeder Z1aand the excipient or the like discharged from the second measuring feeder Z1b. The second connecting pipe Z2bconnects the vertical mixer Z3and the horizontal mixer Z4, to feed the horizontal mixer Z4with the mixed powdery materials of the principal agent and the excipient discharged from the vertical mixer Z3. The third connecting pipe Z2cconnects the third measuring feeder Z1cand the horizontal mixer Z4, to feed the horizontal mixer Z4with the lubricant discharged from the third measuring feeder Z1c. The fourth connecting pipe Z2dconnects the horizontal mixer Z4and the buffer tank19, to feed the buffer tank19with the mixed powdery materials of the principal agent, the excipient, and the lubricant discharged from the horizontal mixer Z4.

More specifically, the first connecting pipe Z2aincludes a first branch pipe Z2a1connected with the first measuring feeder Z1a, a second branch pipe Z2a2connected with the second measuring feeder Z1b, and a main pipe Z2a3connected with the first branch pipe Z2a1and the second branch pipe Z2a2. The main pipe Z2a3has a lower end connected with the vertical mixer Z3. The vertical mixer Z3thus mixes the powdery materials measured and fed by the first measuring feeder Z1aand the second measuring feeder Z1b.

The second connecting pipe Z2b, the third connecting pipe Z2c, and the fourth connecting pipe Z2dwill be described later.

As shown exemplarily inFIGS. 5 to 8, the vertical mixer Z3includes a lid Z36having a feed port Z361for a powdery material, a first case Z31disposed below the lid Z36and having a funnel shape, an agitation shaft Z33disposed substantially in the center of the first case Z31and configured to spin, an agitating rotor Z34(i.e., a first mixing member) attached to the agitation shaft Z33, a motor Z37configured to rotate (i.e., spin) the agitation shaft Z33, a powdery material passing member Z32disposed below the first case Z31and having a plurality of bores Z321, an auxiliary rotor Z35(i.e., a first mixing member) configured to facilitate a powdery material to pass through the bores Z321of the powdery material passing member Z32, and a second case Z38covering the powdery material passing member Z32. The agitating rotor Z34and the auxiliary rotor Z35each function as the first mixing member. The configuration according to the exemplary embodiment includes both the agitating rotor Z34and the auxiliary rotor Z35, while the exemplary invention is also applicable to another configuration including only one of the agitating rotor Z34and the auxiliary rotor Z35.

The agitation shaft Z33of the vertical mixer Z3is not necessarily disposed vertically but can be slanted. The vertical mixer Z3has only to be configured to agitate and mix powdery materials while the powdery materials fed from the feed port Z361are flowing downward.

The powdery materials fed to the feed port Z361of the vertical mixer Z3are mixed by rotation of the agitating rotor Z34. The powdery materials can alternatively be mixed by rotation of the auxiliary rotor Z35.

The lid Z36includes the feed port Z361and a shaft port Z362allowing the agitation shaft Z33to pass therethrough, and is shaped to cover an upper opening of the first case Z31. The lid Z36is attached to the first case Z31so as to prevent a powdery material from spilling or scattering from the first case Z31. The feed port Z361of the lid Z36is connected with the first connecting pipe Z2a. The powdery materials fed from the feed port Z361into the first case Z31are agitated and mixed by rotation of the agitating rotor Z34and/or the auxiliary rotor Z35. The powdery material passing member Z32disposed at a reservoir Z30has the plurality of bores Z321through which the mixed powdery materials pass.

Adjustment in amount of the powdery materials fed from the feed port Z361or increase in a rotational speed of the auxiliary rotor Z35can cause the powdery materials fed from the feed port Z361to be larger in amount than the powdery materials passing through the bores Z321. A certain amount of the powdery materials will thus remain in the reservoir Z30. Specifically, at least part of the powdery materials measured and fed by the first measuring feeder Z1aand the second measuring feeder Z1bremain in the reservoir Z30in the vertical mixer Z3and is agitated by the auxiliary rotor Z35, to achieve improvement in mixing degree of the powdery materials. There can be included a plurality of feed ports Z361.

The first case Z31has the open top and the powdery material passing member Z32is disposed below the first case Z31. The first case Z31according to the exemplary embodiment has the substantially funnel shape, while the first case Z31is not limited to this shape but can have any shape if it is configured to feed the powdery material passing member Z32with a powdery material.

The agitation shaft Z33is disposed in the center of the first case Z31in a planar view and is driven to rotate (i.e., spin) by the motor Z37. The agitating rotor Z34is attached to each of the top and the center in the axial direction of the agitation shaft Z33, and the auxiliary rotor Z35is attached to the lower end in the axial direction of the agitation shaft Z33. Rotation of the agitation shaft Z33causes rotation of the agitating rotors Z34and the auxiliary rotor Z35.

The agitating rotors Z34(i.e., the first mixing members) agitate and mix the powdery materials fed from the feed port Z361into the first case Z31. The agitating rotors Z34can have any shape. The agitating rotors Z34shown exemplarily inFIGS. 5 and 6have a rectangular distal end and are disposed at two positions on the agitation shaft Z33. The vertical mixer Z3shown exemplarily inFIG. 8is configured partially differently from the vertical mixer Z3shown exemplarily inFIGS. 5 and 6. The vertical mixer Z3shown exemplarily inFIG. 8includes the agitating rotor Z34disposed at a single position on the agitation shaft Z33and shaped differently from the agitating rotors Z34shown exemplarily inFIGS. 5 and 6. The agitating rotors Z34are not limited in terms of their shapes or positions to those shown exemplarily inFIGS. 5, 6, and 8.

As shown exemplarily inFIG. 7, the powdery material passing member Z32at the reservoir Z30is disposed below the first case Z31and includes the plurality of bores Z321. The powdery material passing member Z32is covered with the second case Z38. A powdery material passing through the bores Z321of the powdery material passing member Z32is discharged from a discharge port Z381disposed at the bottom of the second case Z38. The number and the diameter of the bores Z321are set appropriately. Such a configuration allows powdery materials to remain at the powdery material passing member Z32and achieves improvement in mixing degree of the powdery materials. A powdery material passing through the bores Z321of the powdery material passing member Z32in a first vertical mixer Z3ais fed to the horizontal mixer Z4by way of the second connecting pipe Z2b.

The auxiliary rotor Z35agitates a powdery material in the reservoir Z30. The auxiliary rotor Z35is disposed in the center of the reservoir Z30in a planar view and is attached to the lower end of the agitation shaft Z33. The auxiliary rotor Z35according to the exemplary embodiment is shaped to follow the inner shape of the powdery material passing member Z32and facilitates a powdery material to pass through the bores Z321. The auxiliary rotor Z35is also configured as a type of an agitating rotor.

The vertical mixer Z3according to the exemplary embodiment includes the agitating rotor Z34. The vertical mixer Z3can alternatively be configured by the second case Z38, the powdery material passing member Z32, and the auxiliary rotor Z35. The second case Z38covers the powdery material passing member Z32, has a substantially funnel shape, and has the discharge port Z381at the bottom. The second case Z38guides a powdery material passing through the bores Z321of the powdery material passing member Z32to the discharge port Z381.

The second connecting pipe Z2bconnects the vertical mixer Z3and the horizontal mixer Z4to be described later. The second connecting pipe Z2bis connected to the bottom of the vertical mixer Z3and the top of the horizontal mixer Z4, to feed the horizontal mixer Z4with the powdery materials passing through the discharge port Z381of the vertical mixer Z3.

As shown exemplarily inFIG. 5, the horizontal mixer Z4functioning as the second mixer includes a cylindrical case Z41, an agitation shaft Z42disposed substantially in the center of the case Z41and configured to spin, a motor Z43configured to rotate (i.e., spin) the agitation shaft Z42, and an agitating rotor Z44attached to the agitation shaft Z42and configured to rotate to move a powdery material substantially horizontally. The horizontal mixer Z4mixes the fed powdery materials, namely, the principal agent and the excipient or the like with the lubricant. The case Z41according to the exemplary embodiment does not rotate (i.e., spin), but can alternatively be configured to rotate. This may achieve further improvement in mixing degree of the powdery materials.

The case Z41has a top including a plurality of feed ports that allows powdery materials to be fed into the case Z41, and a discharge port Z413that allows mixed powdery materials to be discharged from the case Z41. The configuration according to the exemplary embodiment includes two feed ports (e.g., first and second feed ports Z411and Z412), and the second connecting pipe Z2bis connected to the first feed port Z411of the case Z41of the horizontal mixer Z4. The first feed port Z411feeds the case Z41with the mixed powdery materials of the principal agent and the excipient or the like. The agitating rotor Z44rotates to move the mixed powdery materials fed into the case Z41toward the discharge port Z413of the case Z41. The second feed port Z412feeds the lubricant from the third connecting pipe Z2c. The agitation shaft Z42and the agitating rotor Z44rotate to move the lubricant fed into the case Z41toward the discharge port Z413of the case Z41. Any of the feed ports not in use may be closed by a lid.

The discharge port Z413is disposed at the bottom of the case Z41. The discharge port Z413is connected with the fourth connecting pipe Z2dto be described later. The agitating rotor Z44rotates to discharge the mixed powdery materials from the case Z41through the discharge port Z413to the fourth connecting pipe Z2d.

The agitation shaft Z42extends in a longitudinal direction of the case Z41and is disposed substantially in the center in a sectional view. The agitation shaft Z42is driven to rotate (i.e., spin) by the motor Z43. As shown exemplarily inFIG. 9, the agitating rotor Z44is attached to the agitation shaft Z42. Rotation of the agitation shaft Z42causes rotation of the agitating rotor Z44to simultaneously mix and move the powdery materials toward the discharge port Z413.

The agitating rotor Z44is configured to agitate and mix the powdery materials fed into the case Z41through the feed ports (e.g., Z411and Z412). The agitating rotor Z44can have any shape, but is preferably configured to simultaneously mix and move the powdery materials toward the discharge port Z413. As shown exemplarily inFIG. 9, the agitating rotor Z44according to the exemplary embodiment is shaped to have both expanded ends, and is attached to the agitation shaft Z42at a freely adjustable angle.

The third measuring feeder Z1cis configured to measure and feed a lubricant to the horizontal mixer Z4. The third connecting pipe Z2cis connected to the bottom of the third measuring feeder Z1c. The lubricant in the third measuring feeder Z1cis fed to the horizontal mixer Z4through the third connecting pipe Z2c. The lubricant can alternatively be fed to the horizontal mixer Z4by a μR feeder (e.g., manufactured by Nisshin Engineering Inc.). The lubricant can still alternatively be fed to the horizontal mixer Z4by an atomizer (e.g., spray device).

The third connecting pipe Z2cincludes a branch pipe Z2c1and a main pipe Z2c2. The branch pipe Z2c1has a first end connected to the bottom of the third measuring feeder Z1c, and a second end connected to the main pipe Z2c2. The lower end of the main pipe Z2c2is connected to the second feed port Z412of the horizontal mixer Z4.

The fourth connecting pipe Z2dhas an upper end connected with the discharge port Z413of the horizontal mixer Z4and a lower end connected with the feed port Z361of the buffer tank19. The mixed powdery materials are fed through the discharge port Z413of the horizontal mixer Z4and the fourth connecting pipe Z2dto the buffer tank19.

The buffer tank19has a bottom connected to the compression-molding machine. The mixed powdery materials passing through the buffer tank19are delivered toward the feeder X in the molding machine by way of the powdery material mixing degree measurement device M and are eventually compression molded in the die bores4.

The powdery-material feeding device Z according to the exemplary embodiment checks whether or not the mixing degree of the mixed powdery materials is within an appropriate range and whether or not the mixed powdery materials mixedly contain a biologically-originated foreign matter, like a human hair or a bug, and then feeds the powdery materials to the feeder X of the molding machine.

Examples of a method of measuring a mixing degree of mixed powdery materials include Raman spectroscopy, infrared spectroscopy, X-ray diffraction, X-ray transmission measurement, and high performance liquid chromatography (HPLC). Any one of these methods is applicable if the mixing degree of the mixed powdery materials is promptly measured. The same applies to a method of sensing foreign matter mixedly contained in a powdery material. Any method is applicable if such foreign matter is promptly detected. There is also an adoptable manner of irradiating, with near infrared light or the like, a powdery material passing a predetermined detection position on a powdery material flow passage, causing the near infrared light or the like having transmitted through the powdery material to be incident on a camera sensor to obtain an image of the transmitted light, and analyzing the obtained image to detect foreign matter like human hair or a bug.

There are provided detectors S1to S5configured to detect the mixing degree of the mixed powdery materials and to detect a foreign matter. These detectors S1to S5are dependent, in terms of their specific aspect, on a detection method thereof. The exemplary embodiment assumes adoption of a near infrared reflectance (NIR), or a near infrared absorption spectrum method. Specifically, in order to evaluate an amount or a percentage (i.e., ratio) of the principal agent in the mixed powdery materials (i.e., uniformity of the mixed powdery materials) (whether or not the mixed powdery materials are segregated), the mixed powdery materials moving from the powdery-material feeding device Z toward the feeder X of the molding machine are irradiated with near infrared light to measure light absorption (e.g., by detecting and dispersing transmitted light or reflected light) for qualitative and quantitative analyses of a concentration and the like of the principal agent based on a spectrum thereof. These analyses are repeatedly conducted at predetermined cycles. A measured wavelength falls in a wavelength range including a unique absorption peak of the principal agent and no peak of the excipient or the lubricant. The near infrared reflectance also enables measurement of particle diameters of the mixed powdery materials to sense the foreign matter mixedly contained in the powdery materials. When the near infrared reflectance method is adopted, process analytical technology (PAT) sensors functioning as the detectors S1to S5are configured by probes each including a near infrared sensor.

The mixed powdery materials delivered toward the feeder X of the molding machine by way of the buffer tank19of the powdery-material feeding device Z have the mixing degree promptly measured by the powdery material mixing degree measurement device M or the sensors S1to S5disposed on an upstream or a downstream of the powdery material mixing degree measurement device M, and are also promptly checked whether or not the foreign matter is mixedly contained. The mixed powdery materials having a mixing degree out of a predetermined range or mixedly containing the foreign matter are inhibited from being fed to the feeder X. This case also involves issuance of an alarm sound, a suspension of the powdery-material feeding device Z and the molding machine, and the like.

As shown exemplarily inFIGS. 10 and 11, the configuration according to the exemplary embodiment includes a first sensor S1configured to initially measure the mixing degree of the mixed powdery materials and/or check whether or not the mixed powdery materials contain a biologically-originated foreign matter before the mixed powdery materials are reserved in the buffer tank19.

After the first sensor S1measures the mixing degree of the powdery materials and/or checks whether or not the mixed powdery materials contain foreign matter, the mixed powdery materials are temporarily reserved in the buffer tank19as a reservoir. After a second sensor S2measures the mixing degree of the powdery materials reserved in the buffer tank19and/or checks whether or not the powdery materials contain foreign matter again, the powdery materials are fed to the powdery material mixing degree measurement device M. The mixed powdery materials can optionally be further agitated and mixed in the buffer tank19.

As shown exemplarily inFIGS. 12 and 13, the powdery material mixing degree measurement device M includes a case M1, a rotator M2as a movable member in the case M1, a motor M3as a driver for the rotator M2, second and third sensors S2and S3configured to measure a mixing degree of powdery materials and/or check whether or not foreign matter is contained, a powdery-material removal mechanism M4configured to remove defective mixed powdery materials, the feeding unit M5configured to introduce the mixed powdery materials from the buffer tank19into the case M1, and the discharger M6configured to discharge the mixed powdery materials to the agitated feeder X functioning as a filling device of the compression-molding machine.

As shown exemplarily inFIG. 14, the case M1has a bottom surface including an attachment bore M11allowing the third sensor S3to be mounted therein, a removal bore M12(the powdery-material removal mechanism M4) for removal of a powdery material, and a discharge bore M13(the discharger M6) for discharge of a powdery material to the powdery-material feed pipe191. The case M1has a top surface on which the feeding unit M5configured to feed the case M1with a powdery material is mounted. The mixed powdery materials enter the case M1by way of the buffer tank19and the feeding unit M5. The feeding unit M5is provided with the second sensor S2configured to measure a mixing degree of the mixed powdery materials passing through the feeding unit M5and to check whether or not foreign matter is mixedly contained.

The rotator M2includes a plurality of movable portions M21. The feeding unit M5feeds the movable portions M21with the mixed powdery materials. The rotator M2is driven to rotate by the motor M3positioned above the rotator M2.

The third sensor S3is attached to the attachment bore M11of the case M1, and is configured to measure a mixing degree of a powdery material fed to the movable portions M21and/or check whether or not the powdery material fed to the movable portions M21mixedly contains the foreign matter.

The powdery-material removal mechanism M4includes a case, a drive body M41, and a driver M42configured to drive the drive body M41. The case of the powdery-material removal mechanism M4is provided integrally with the case M1. The drive body M41according to the exemplary embodiment has a circular disc shape, and includes a center projection M411engaged with the driver M42, and a partial cutoff portion M412. The driver M42has a distal end M421configured to drive forward and backward along a Y axis indicated inFIG. 13, and an engagement bore M422disposed at the distal end and engaged with the projection M411of the drive body M41.

In a state where the distal end M421of the driver M42moves in a positive direction along the Y axis as indicated inFIG. 13, the cutoff portion M412of the drive body M41is located in the center of the removal bore M12of the case M1. In another state where the distal end M421moves in a negative direction along the Y axis, the cutoff portion M412is spaced apart from the removal bore M12of the case M1.

Specifically, in the case where the driver M42drives to move the distal end M421in the negative direction along the Y axis, the drive body M41is driven clockwise together therewith and the cutoff portion M412is not overlapped with the removal bore M12. A powdery material in the movable portions M21of the rotator M2is not removed in this case. In the other case where the driver M42drives to move the distal end M421in the positive direction along the Y axis, the drive body M41is driven counterclockwise together therewith and the cutoff portion M412is overlapped with the removal bore M12. The powdery material in the movable portions M21of the rotator M2is removed in this case.

The drive body M41according to the exemplary embodiment is driven clockwise and counterclockwise to remove the powdery material in the movable portions M21of the rotator M2. The drive body M41can alternatively be configured to rotate only in one direction to remove the powdery material in the movable portions M21.

If any of the first to third sensors S1to S3measures a mixing degree of the powdery materials (i.e., an amount or a percentage (i.e., ratio) of the principal agent in the mixed powdery materials, being out of the predetermined range), or detects a biologically-originated foreign matter mixedly contained in the mixed powdery materials, then the powdery-material removal mechanism M4removes the mixed powdery materials in the movable portions M21. The mixed powdery materials in the movable portions M21can be removed in a case where all the first to third sensors S1to S3have measurement values of mixing degrees out of the predetermined range or all the sensors S1to S3sense foreign matter, or in another case where any of the sensors S1to S3has a measurement value out of the predetermined range or any of the sensors S1to S3senses foreign matter.

The powdery-material removal mechanism M4is also configured to sample the mixed powdery materials.

The mixed powdery materials not removed by the powdery-material removal mechanism M4pass through the discharge bore M13to reach the powdery-material feed pipe191. The mixed powdery materials move to the discharger M6in this case.

A fourth sensor S4is configured to measure a mixing degree of the mixed powdery materials moved to the powdery-material feed pipe191and/or check whether or not foreign matter is mixedly contained before the mixed powdery materials are guided into the agitated feeder X functioning as a filling device of the compression-molding machine. Furthermore, a fifth sensor S5is configured to measure a mixing degree of the mixed powdery materials and/or check whether or not foreign matter is mixedly contained, also in the agitated feeder X of the compression-molding machine according to the exemplary embodiment.

If the fourth sensor S4and/or the fifth sensor S5disposed downstream of the powdery-material removal mechanism M4measures a mixing degree of the powdery materials out of the predetermined range or the fourth sensor S4and/or the fifth sensor S5senses a biologically-originated foreign matter, then the mixed powdery materials in the feeder X are once filled in each of the die bores4of the table31of the molding machine and are compression molded by the upper and lower punches5and6into the shape of a molded product. The molded product is then removed by the molded-product removal mechanism W before reaching the molded-product collecting position18. Specifically, in the compression-molding machine, the control valve22is opened when the die bore4filled with defective mixed powdery materials tableted into a molded product passes by the air spray nozzle16a, and the air spray nozzle16asprays air to blow the molded product out of the table31.

The molded-product removal mechanism W removes a molded-product compression molded in any of the die bores4also in a case where any of the load cells121detects that compression pressure applied to the powdery material compressed in the die bore4is out of a predetermined range.

Summarized again below is a flow of continuous production of compression molded products by the molding machine system according to the exemplary embodiment. Initially, the first measuring feeder Z1asimultaneously measures and feeds the principal agent, and the second measuring feeder Z1bsimultaneously measures and feeds the excipient or the like. The vertical mixer Z3functioning as the first mixer is subsequently fed with the powdery materials of the principal agent and the excipient or the like and mixes the powdery materials therein. In the vertical mixer Z3, the agitating rotor Z34rotates about the agitation shaft Z33disposed substantially vertically, to mix the powdery materials of the principal agent and the excipient or the like.

The horizontal mixer Z4functioning as the second mixer is fed with the mixed powdery materials of the principal agent and the excipient or the like subjected to the mixing by the first mixer, and mixes the powdery materials again. In the horizontal mixer Z4, the agitating rotor Z44rotates about the agitation shaft Z42disposed substantially horizontally, to mix the powdery materials of the principal agent and the excipient or the like. Such a process achieves improvement in mixing degree of the at least two types of powdery materials (e.g., the principal agent and the excipient or the like), and causes less segregation of the principal agent. The powdery materials having been mixed by the horizontal mixer Z4can optionally be fed to an additional vertical mixer to be mixed again. This will achieve further improvement in mixing degree of the powdery materials.

The powdery materials are preferred to be reserved at least partially during mixing by the first mixer. Specifically, the powdery materials pass through the plurality of bores Z321of the powdery material passing member Z32. The reservoir Z30reserves powdery materials by increase in an amount of the powdery materials to be fed to the first vertical mixer Z3ato be more than the powdery materials passing through the bores Z321or increase in a rotational speed of the auxiliary rotor Z35. The powdery materials then pass through the bores Z321while being agitated and mixed by the auxiliary rotor Z35.

Furthermore, the third measuring feeder Z1csimultaneously measures and feeds the lubricant. The lubricant is fed to the horizontal mixer Z4in the exemplary embodiment, but can alternatively be fed to a second vertical mixer Z3b, the feeder X, or the like, with no limitation in feeding destination of the lubricant to the horizontal mixer Z4. The lubricant can be fed by the μR feeder (e.g., manufactured by Nisshin Engineering Inc.) or by an atomizer (e.g., spray device).

The mixed powdery materials including the principal agent, the excipient or the like, and the lubricant are fed to the buffer tank19of the molding machine.

As shown exemplarily inFIG. 16, the controller C in the molding machine system according to the exemplary embodiment causes the sensors S1to S3to repeatedly measure mixing degrees of the mixed powdery materials before and after being fed to the buffer tank19, and causes the sensors S1to S3to repeatedly check whether or not the mixed powdery materials mixedly contain a biologically-originated foreign matter. If the measured mixing degree of the mixed powdery materials is out of the predetermined range or if foreign matter is detected in the mixed powdery materials, then the controller C starts the driver M42of the powdery-material removal mechanism M4included in the powdery-material feeding device Z to remove the mixed powdery materials before being fed to the feeder X of the molding machine.

The mixed powdery materials fed to the feeder X are filled in the die bores4of the table31of the turret3in the molding machine. Prior to filling each of the die bores4with the powdery materials in the compression-molding machine, a lubricant (e.g., external lubricant) can optionally be sprayed to a lower end surface of the upper punch5, an upper end surface of the lower punch6, and an inner circumferential surface of the die bore4.

The mixed powdery materials filled in each of the die bores4are compression molded by the upper and lower punches5and6. The mixed powdery materials compression molded into a molded product are guided by the guide member17and are collected at the molded-product collecting position18.

However, the controller C in the compression-molding machine system according to the exemplary embodiment causes the sensors S4and S5to repeatedly measure the mixing degree of the mixed powdery materials fed to the feeder X and filled in the die bores4by the powdery-material feeding device Z, and further causes the sensors S4and S5to repeatedly check whether or not the mixed powdery materials mixedly contain a biologically-originated foreign matter. If the measured mixing degree of the mixed powdery materials is out of the predetermined range or if foreign matter is detected in the mixed powdery materials, then the molded-product removal mechanism W included in the molding machine removes a defective molded-product compression molded in the die bore4filled with the mixed powdery materials. Specifically, the control valve22is opened when the die bore4filled with the defective molded product passes by the air spray nozzle16a, and the air spray nozzle16asprays compressed air to blow the molded product out of the table31.

The controller C further causes the load cells121to measure a compression pressure applied from the punches5and6to the powdery materials in each of the die bores4to obtain a molded product. In a case where compression pressure is out of a predetermined range, the controller C causes the molded-product removal mechanism W to remove a defective molded-product compression molded in the die bore4having compression pressure out of the predetermined range. In a case where a powdery material filled in the die bore4is more than an appropriate amount, compression pressure measured by the load cell121exceeds the predetermined range. In another case where the powdery material filled in the die bore4is less than the appropriate amount, compression pressure measured by the load cell121is less than the predetermined range. In either one of the cases, the molded-product compression molded in the die bore4has weight, density, and hardness different from desired values and is regarded as defective.

When the die bore4assumed to be filled with the mixed powdery materials having a mixing degree out of the predetermined range or mixedly containing foreign matter or the die bore4receiving compression pressure out of the predetermined range (i.e., the possibly defective molded product), passes by the air spray nozzle16a, is found by referring to an output signal from the rotary encoder23.

When any of the sensors S1to S5detects the mixing degree of the mixed powdery materials out of the predetermined range or detects foreign matter mixedly contained in the mixed powdery materials, the controller C can stop the feeding of the powdery materials by the powdery-material feeding device Z or stop an operation of the molding machine.

Originally, the first measuring feeder Z1ais configured to feedback control weight (i.e., a flow rate) of the fed principal agent per unit time, the second measuring feeder Z1bis configured to feedback control weight of the fed excipient or the like per unit time, and the third measuring feeder Z1cis configured to feedback control weight of the fed lubricant per unit time. Furthermore, these powdery materials are to be mixed at a desired mixture ratio. Even in this configuration, the amounts of the powdery materials discharged from the measuring feeders Z1and fed to the mixers Z3and Z4can somehow deviate from initial target amounts. The powdery material fed from any of the measuring feeders Z1to the mixer Z3or Z4is sometimes smaller than the target amount. In such a case, the amount of the principal agent in the mixed powdery materials has a ratio larger or smaller than the desired ratio. A molded product obtained by compression-molding such mixed powdery materials is defective, failing to exert an expected drug effect.

Even if the mixer Z3or Z4fails to adequately mix the powdery materials and the mixed powdery materials fed to the feeder X of the molding machine have segregation of the principal agent or the excipient, molded products will be defective with different contents.

In view of this, the controller C of the molding machine system according to the exemplary embodiment adjusts, in accordance with the mixing degree measurement value of the mixed powdery materials by any of the first to fifth sensors S1to S5, the amounts of the powdery materials fed by the measuring feeders Z1ato Z1c, a rotational speed of the agitation shaft Z33, the agitating rotor Z34, and the auxiliary rotor Z35of the vertical mixer Z3, and a rotational speed of the agitation shaft Z42and the agitating rotor Z44of the horizontal mixer Z4. Examples of the controller C include a microcomputer system including a processor, a memory, an auxiliary storage device, and an input/output interface, a programmable controller, a general-purpose personal computer, and a general-purpose work station.

In a case where the absolute value of a difference between a target value and the amount or the percentage of the principal agent in the mixed powdery materials repeatedly measured by any of the first to fifth sensors S1to S5is more than a predetermined threshold (i.e., the percentage of the principal agent is inappropriately small or large) continuously for at least a certain period, at least one of the first to third measuring feeders Z1ato Z1cis regarded as failing to feed an appropriate amount of the powdery material. In this case, the controller C temporarily interrupts weight feedback control by the measuring feeders Z1themselves and adjusts a rotational speed of a drive motor of each of the measuring feeders Z1such that the amount or the percentage of the principal agent in the mixed powdery materials measured by any of the first to fifth sensors S1to S5is approximate to the target value. In a case where the measured amount or the measured percentage of the principal agent in the mixed powdery materials is less than the target value, the first measuring feeder Z1aincreases the amount of the discharged principal agent, and/or the second measuring feeder Z1bdecreases the amount of the discharged excipient or the like and the third measuring feeder Z1cdecreases the amount of the discharged lubricant. In another case where the measured amount or the measured percentage of the principal agent in the mixed powdery materials is more than the target value, the first measuring feeder Z1adecreases the amount of the discharged principal agent, and/or the second measuring feeder Z1bincreases the amount of the discharged excipient or the like and the third measuring feeder Z1cincreases the amount of the discharged lubricant.

Alternatively, if the absolute value of the difference between the target value and the amount or the percentage of the principal agent in the mixed powdery materials is more than the threshold continuously for at least the certain period, then the target value of the amount of the discharged powdery materials commanded by the controller C to the measuring feeders Z1ato Z1ccan be changed to optimize the amount of the fed principal agent. In a case where the measured amount or the measured percentage of the principal agent in the mixed powdery materials is less than the target value, the first measuring feeder Z1ahas a higher target value of the amount of the discharged principal agent, and/or the second measuring feeder Z1bhas a lower target value of the amount of the discharged excipient or the like and the third measuring feeder Z1chas a lower target value of the amount of the discharged lubricant.

In another case where the measured amount or the measured percentage of the principal agent in the mixed powdery materials is more than the target value, the first measuring feeder Z1ahas a lower target value of the amount of the discharged principal agent, and/or the second measuring feeder Z1bhas a higher target value of the amount of the discharged excipient or the like and the third measuring feeder Z1chas a higher target value of the amount of the discharged lubricant.

In a case where the absolute value of the difference between the target value and the amount or the percentage of the principal agent in the mixed powdery materials repeatedly measured by any of the first to fifth sensors S1to S5is more than the threshold not continuously for at least the certain period but is more than the threshold instantaneously or only for a short period, (e.g., the principal agent, the excipient or the like, or the lubricant in) the mixed powdery materials moving toward the feeder X of the compression-molding machine is regarded as having segregation (i.e., locally having portions of high and low concentrations of the principal agent). In this case, the controller C changes (e.g., increases or decreases) a current rotational speed of each of the agitation shaft Z33and the agitating rotors Z34and Z35of the vertical mixer Z3, and/or changes (e.g., increases or decreases) a current rotational speed of each of the agitation shaft Z42and the agitating rotor Z44of the horizontal mixer Z4, for further improvement in mixing degree of the powdery materials.

Also, in the case where the absolute value of the difference between the target value and the amount or the percentage of the principal agent in the mixed powdery materials is more than the threshold continuously for at least the certain period, the controller C can control to change a current rotational speed of the agitating rotors Z34and Z35of the vertical mixer Z3and/or to change a current rotational speed of the agitating rotor Z44of the horizontal mixer Z4.

As described above, increasing or decreasing each of the amounts of the powdery materials discharged from the measuring feeders Z1ato Z1c, changing a rotational speed of the agitation shaft Z33of the vertical mixer Z3, or changing a rotational speed of the agitation shaft Z42of the horizontal mixer Z4can possibly cause change in flow rate per unit time of the mixed powdery materials fed to the powdery-material feed pipe191connected to the feeder X of the molding machine. When any of the sensors S1to S3detects a mixing degree of the mixed powdery materials is out of the predetermined range or detects a mixedly contained foreign matter, the powdery-material removal mechanism M4removes the powdery materials, to possibly temporarily decrease the flow rate per unit time of the mixed powdery materials fed to the powdery-material feed pipe191.

If the turret3and the punches5and6of the molding machine are kept rotating at a constant rotational speed despite variation in flow rate of the mixed powdery materials moving toward the powdery-material feed pipe191, then the mixed powdery materials accumulated in the powdery-material feed pipe191have an upper surface L at a varied level because the molding machine uses a constant amount of the mixed powdery materials per unit time. The level of the upper surface L of a powdery material in the powdery-material feed pipe191is raised in a case where the powdery material fed to the powdery-material feed pipe191has a flow rate per unit time more than the amount of the powdery material used by the molding machine per unit time. The level of the upper surface L of the powdery material in the powdery-material feed pipe191is lowered in another case where the powdery material fed to the powdery-material feed pipe191has a flow rate per unit time less than the amount of the powdery material used by the molding machine per unit time.

Large variation in a level of the upper surface L of the powdery material in the powdery-material feed pipe191disposed above and directly connected to the feeder X may lead to an increase or a decrease from the appropriate amount of the powdery material filled into the die bores4from the feeder X and defectiveness of the product molded in the die bores4.

In order to inhibit such a variation in an amount of the filled powdery material, the controller C according to the exemplary embodiment causes a sensor S6to detect the level of the upper surface L of the mixed powdery materials in the powdery-material feed pipe191and adjusts a rotational speed of the motor8, eventually the turret3and the punches5and6of the molding machine in accordance with the level of the upper surface.

As shown exemplarily inFIG. 19, the powdery-material feed pipe191has two capacitance level switches S61and S62each functioning as the sensor S6. The level switches S61and S62are configured to detect whether the level of the upper surface L of a powdery material accumulated in the powdery-material feed pipe191is higher or lower than the level switches S61and S62, respectively. The controller C is configured to determine, with use of the level switches S61and S62, whether the level of the upper surface L of the powdery material in the feed pipe191is above the upper level switch S61, is below the upper level switch S61and above the lower level switch S62, or is below the lower level switch S62. When the level of the upper surface L of the powdery material in the feed pipe191is below the upper level switch S61and above the lower level switch S62, the upper surface level of the powdery material is regarded as being within a desired target range.

In a case where the upper surface level of the powdery material in the powdery-material feed pipe191is not lower than the upper limit of the target range (i.e., when the upper surface level is not lower than the upper level switch S61), the controller C according to the exemplary embodiment increases a rotational speed of the turret3and the punches5and6of the molding machine in comparison to a case where the upper surface level is within the target range. This leads to an increase in an amount of the powdery material used by the molding machine per unit time and decrease in upper surface level of the powdery material in the powdery-material feed pipe191to be within the target range.

In another case where the upper surface level of the powdery material in the powdery-material feed pipe191is not higher than the lower limit of the target range (i.e., when the upper surface level is not higher than the lower level switch S62), the controller C decreases a rotational speed of the turret3and the punches5and6of the molding machine in comparison to the case where the upper surface level is within the target range. This leads to a decrease in an amount of the powdery material used by the molding machine per unit time and an increase in the upper surface level of the powdery material in the powdery-material feed pipe191to be within the target range.

When the rotational speed of the turret3and the punches5and6of the molding machine is controlled, a period of an increase in a rotational speed while the upper surface level of the powdery material in the powdery-material feed pipe191decreases from the upper limit toward the lower limit of the target range, and a period of a decrease in a rotational speed while the upper surface level of the powdery material in the feed pipe191increases from the lower limit toward the upper limit of the target range, can repeat alternately.

As indicated inFIG. 20, the controller C according to the exemplary embodiment controls, under such a condition, a rotational speed of the turret3and the punches5and6in a first period of an increase in a speed and a subsequent second period of an increase in the speed such that the second period is longer than the first period. For example, the rotational speed of the turret3and the punches5and6in the subsequent second period of an increase in the speed is made lower than the rotational speed of the turret3and the punches5and6in the first period of increase in speed.

The controller C also controls the rotational speed of the turret3and the punches5and6in a first period of decrease in speed and a subsequent second period of a decrease in the speed such that the second period is longer than the first period. For example, the rotational speed of the turret3and the punches5and6in the subsequent second period of an increase in the speed is made higher than the rotational speed of the turret3and the punches5and6in the first period of increase in speed. Such control eventually allows the upper surface level of the powdery material in the powdery-material feed pipe191to stably be kept without reaching the upper limit or the lower limit of the target range.

As already described, the powdery-material removal mechanism M4of the powdery-material feeding device Z configured to deliver a powdery material toward the powdery-material feed pipe191occasionally removes the defective powdery material without feeding to the powdery-material feed pipe191. Removal of such a powdery material by the powdery-material removal mechanism M4leads to a decrease in an amount of the powdery material delivered toward the powdery-material feed pipe191per unit time, so that the upper surface level of the powdery material in the powdery-material feed pipe191may be decreased.

In a case where the powdery-material removal mechanism M4removes the powdery material even though the upper surface level of the powdery material is below the upper level switch S61and above the lower level switch S62, the controller C according to the exemplary embodiment conducts a feed-forward control of decreasing a rotational speed of the turret3and the punches5and6of the molding machine in comparison to the contrast case. Specifically, when the controller C receives a signal indicating that the driver M42in the powdery-material removal mechanism M4operates and the powdery material captured by the movable portions M21of the rotator M2is dropped into the removal bore M12, the controller C decreases a current rotational speed of the turret3and the punches5and6. Assume that the rotational speed of the turret3and the punches5and6has a value obtained by multiplying the rotational speed immediately before the decrease in speed and a coefficient (larger than zero and) smaller than one.

When the controller C controls to decrease the rotational speed of the turret3and the punches5and6of the molding machine in response to removal of the powdery material by the powdery-material removal mechanism M4, the rotational speed is decreased preferably at a rate according to the rotational speed immediately before the decrease in speed.

In a case where the turret3and the punches5and6immediately before the decrease in speed have a relatively high rotational speed, the powdery-material feeding device Z feeds the powdery-material feed pipe191and eventually the feeder X with the powdery material originally having a large flow rate per unit time. Meanwhile, the powdery-material removal mechanism M4removes, at one time, the powdery material having a fundamentally constant amount equal to that of the powdery material captured by one of the movable portions M21of the rotator M2. Accordingly, in a case where the powdery material is removed while the turret3and the punches5and6have a relatively high rotational speed, the powdery-material feeding device Z feeds the powdery-material feed pipe191with the powdery material having a small decrease rate per unit time and such removal has a relatively small influence. The rotational speed of the turret3and the punches5and6of the molding machine can thus have a small decrease rate upon removal of the powdery material, so that the coefficient multiplied by the rotational speed immediately before the decrease in the speed is set to have a larger value.

In another case where the turret3and the punches5and6have a relatively low rotational speed immediately before the decrease in speed, the powdery-material feeding device Z feeds the powdery-material feed pipe191with the powdery material originally having a small flow rate per unit time. Meanwhile, the powdery-material removal mechanism M4removes, at one time, the powdery material having a fundamentally constant amount. If the powdery material is removed while the turret3and the punches5and6have a relatively low rotational speed, then the powdery-material feeding device Z feeds the powdery-material feed pipe191with the powdery material having a large decrease rate per unit time and such removal has a relatively large influence. The rotational speed of the turret3and the punches5and6of the molding machine thus needs to have a large decrease rate upon removal of the powdery material, so that the coefficient multiplied by the rotational speed immediately before the decrease in speed is set to have a smaller value.

The exemplary embodiment provides the powdery-material feeding device Z configured to feed a powdery material to the compression-molding machine configured to obtain a molded product by filling the die bore4with the powdery material and to compress the powdery material with the punches5and6. The powdery-material feeding device Z includes the detector S1, S2, or S3configured to detect a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine. The controller C is configured to control to remove the powdery material mixedly containing the biologically-originated foreign matter detected by the detector S1, S2, or S3to avoid feeding of the powdery material mixedly containing the foreign matter to the compression-molding machine, or to control to stop the feeding of the powdery material to the compression-molding machine. The exemplary embodiment prevents feeding, to the compression-molding machine, of a powdery material mixedly containing a biologically-originated foreign matter, to effectively avoid production of a molded product containing the foreign matter.

The powdery-material feeding device Z according to the exemplary embodiment is configured to feed the molding machine with mixed powdery materials containing at least two types of powdery materials, includes the detectors S1to S3configured to measure a mixing degree of the mixed powdery materials to be fed to the compression-molding machine. When the mixing degree of the mixed powdery materials detected by any of the detectors S1to S3is out of the predetermined range, the controller C controls to remove the mixed powdery materials so as not to be fed to the molding machine or controls to stop feeding of the mixed powdery materials to the molding machine. The exemplary embodiment may prevent feeding, to the molding machine, of mixed powdery materials having a mixing degree out of a normal range, to effectively avoid production of a defective molded product not satisfying desired quality.

The feeder X as a filling device in the molding machine causes a powdery material to fall into the die bores4of the table31by weight of the powdery material. Excessiveness or shortage from the appropriate amount of the powdery material filled in the die bores4leads to finished products having weight, density, and hardness different from the desired values. The powdery material filled in the die bores4needs to have a variation in an amount as small as possible. Constantly keeping the upper surface level of the powdery material in the feed pipe191(i.e., constantly keeping pressure of the powdery material in the feeder X), is effective for constantly filling the die bores4with a constant amount of the powdery material from the feeder X. According to the exemplary embodiment, the powdery-material removal mechanism M4in the powdery-material feeding device Z occasionally removes the powdery material before being fed to the feeder X and the powdery material fed from the powdery-material feeding device Z toward the feeder X has a flow rate not necessarily constant per unit time. Correspondingly to the increased or decreased flow rate, the controller C adjusts a rotational speed of the turret3and the punches5and6of the rotary compression-molding machine to keep the upper surface level of the powdery material in the feed pipe191within the constant target range. This achieves a precisely stabilized appropriate amount of the powdery material filled in the die bores4, to keep high quality of the molded products obtained from the powdery material in the die bores4.

The invention is not limited to the exemplary embodiment detailed above. For example, the above exemplary embodiment applies the detectors S1to S5configured to check whether or not the mixed powdery materials to be fed from the powdery-material feeding device Z to the feeder X of the compression-molding machine mixedly contain a biologically-originated foreign matter and the detectors S1to S5configured to measure a mixing degree of the mixed powdery materials. The exemplary invention is also applicable to a case where the detectors for the former purpose and the detectors for the latter purpose are independent from each other or are disposed at positions different from each other.

Furthermore, a type of foreign matter possibly mixed in a powdery material can vary a calibration curve for detection of the foreign matter. In such a case, a detector (e.g., a near infrared reflectance probe) configured to detect a certain type of foreign matter (e.g., a human hair) can be disposed separately from a detector configured to detect a different type of a foreign matter (e.g., a bug).

The level of the upper surface L of the powdery material in the feed pipe191is detected by the two level switches S61and S62in the above exemplary embodiment. The sensor S6configured to detect a level of the upper surface L of the powdery material is, however, not limited to these level switches S61and S62. Examples of the sensor S6also include a contact level gauge configured to directly contact the powdery material accumulated in the feed pipe191and measure the level of the upper surface L, and a contactless level gauge configured to emit an ultrasonic wave or an electromagnetic wave toward the upper surface L of the powdery material and receive a reflected wave thereof to measure the level of the upper surface L of the powdery material. The level of the upper surface L of the powdery material can alternatively be obtained by photographing the interior of the feed pipe191with a camera sensor and analyzing a captured image with the controller C.

According to the above exemplary embodiment, a rotational speed of the turret3and the punches5and6of the molding machine is adjusted such that the level of the upper surface L of the powdery material in the feed pipe191directly connected to the filling device X is kept within the constant target range. Alternatively, the filling device X can have a level switch or a level gauge configured to obtain an upper surface level of a powdery material in the filling device X (particularly in a case where the filling device X is configured by a gravity feeder) in order for adjustment of a rotational speed of the turret3and the punches5and6of the molding machine such that the upper surface level of the powdery material in the filling device X is kept within the constant target range.

In this case, the rotational speed of the turret3and the punches5and6is increased if the upper surface level of the powdery material in the filling device X is not lower than the upper limit of the target range, whereas the rotational speed of the turret3and the punches5and6is decreased if the upper surface level of the powdery material in the filling device X is not higher than the lower limit of the target range.

In addition, when there are the period of an increase in a rotational speed of the turret3and the punches5and6to allow the upper surface level of the powdery material in the filling device X to be lowered from at or above the upper limit of the target range toward the lower limit of the target range and the period of a decrease in the rotational speed of the turret3and the punches5and6to allow the upper surface level of the powdery material in the filling device X to be raised from at or below the lower limit of the target range toward the upper limit of the target range, the controller C preferably controls the rotational speed of the turret3and the punches5and6such that the subsequent second period of increase in speed is longer than the first period of increase in speed, and preferably controls the rotational speed of the turret3and the punches5and6such that the subsequent second period of decrease in speed is longer than the first period of decrease in speed.

The controller C further preferably decreases the rotational speed of the turret3and the punches5and6in a case where the powdery-material removal mechanism M4included in the device Z configured to deliver a powdery material toward the feed pipe191and the filling device X, and removes the powdery material without feed of the predetermined amount of the powdery material to the feed pipe191.

The controller C can alternatively conduct a feedback control of precisely adjusting the rotational speed of the turret3and the punches5and6of the molding machine in accordance with a degree of a difference between the level of the upper surface L of the powdery material detected by the sensor S6and a target value (which can be a median value, the upper limit, or the lower limit of the target range) so as to keep the level of the upper surface L of the powdery material accumulated in the feed pipe191or in the filling device X within the target range. In a case where the upper surface level of the powdery material is higher than the target value, the rotational speed of the turret3and the punches5and6of the molding machine is decreased as the absolute value of the difference between the upper surface level and the target value is larger. In another case where the upper surface level of the powdery material is lower than the target value, the rotational speed of the turret3and the punches5and6of the molding machine is increased as the absolute value of the difference between the upper surface level and the target value is larger. The controller C embodies a controller in a control system, which can be designed in any appropriate manner. Examples of the manner of designing the controller in the control system include various manners such as a Proportional Integral Derivative (PID) control, a model-based predictive control, and a learning control.

Alternatively, in order to keep the level of the upper surface L of the powdery material accumulated in the feed pipe191or in the filling device X within the target range, the controller C can measure the flow rate of the powdery material fed to the feed pipe191with a flowmeter and control to increase the rotational speed of the turret3and the punches5and6if the flow rate is large.

Further, in order to keep the level of the upper surface L of the powdery material accumulated in the feed pipe191or in the filling device X within the target range, the controller C can measure a pressure (i.e., from the accumulated powdery material) in the feed pipe191or in the filling device X with a pressure gauge and control to increase the rotational speed of the turret3and the punches5and6if the internal pressure is large.

Moreover, specific configurations of the respective portions can be modified without departing from the scope of the exemplary invention.