Powder compression molding machine

Abstract

In a rotary powder compression molding machine, the improper leakage of powder from the feed shoe used for powder filling to the outside is to be appropriately prevented with a simple configuration. [Solution] The bottom plate X22 of the housing of the feed shoe, which fills the die holes on the table of a turntable with powder, has a through window X221 formed therein for dropping in powder that expands in the rotational direction as the die holes move. Furthermore, a sealing material X25 extending in the rotational direction is attached to the lower surface of the bottom plate X22 at positions offset inward and outward along the radial direction perpendicular to the rotational direction from the through window X221. In addition, a slitting plate X26 that expands in the radial direction is attached to the lower surface of the bottom plate X22 near the end of the through window X221 along the rotational direction. The starting and ending ends of the sealing material X25 are supported by a backing plate X23 and a slitting plate X26.

Description

Technical Field

[0004] , , ,

[0001] The present invention relates to a rotary powder compression molding machine that compresses powder to form pharmaceutical tablets, foods, electronic components, etc.

Background Art

[0002] A large number of mortise holes are provided on the outer periphery of the table of a rotating disk, and upper and lower punches are slidably held above and below each mortise hole, respectively. The table and the punches are both rotated horizontally. When the mortise hole passes directly below the powder filling device, powder is filled into the mortise hole. Then, when the pair of upper and lower punches passes between the upper and lower rolls, the powder in the mortise hole is compression molded or tableted. A rotary powder compression molding machine is known.

[0003] As a filling device mounted on the molding machine, a stirring feed chute that incorporates rotating stirring blades and injects powder into the mortise holes while stirring the powder is the mainstream. A through window (powder supply port for the mortise hole) that expands along the rotation direction of the table and the mortise hole is drilled in the bottom plate of the feed chute. The powder in the feed chute is dropped into the mortise holes of the table through this through window. A rubbing plate and a sealing material are attached to the lower surface side of the bottom plate facing the upper surface of the table. The rubbing plate is located near the end of the through window and rubs off the excess powder filled into the mortise hole from the feed chute. The sealing material is located at positions biased inward and outward along the radial direction perpendicular to the rotation direction as seen from the through window, and suppresses the diffusion of powder to parts other than the mortise holes of the table (for example, refer to the following patent document).

[0004] If the sealing material is not properly attached to the bottom plate of the feed shoe (including cases where the sealing material is partially wavy), or if the sealing material is dragged on the table and twisted during the operation of the molding machine, creating a gap between the sealing material and the table surface, powder may leak out of the feed shoe. The leaked powder may contaminate the table and, consequently, the inside of the molding machine over a wide area. The powder used as raw material for molded products often contains substances harmful to the human body. In addition, when manufacturing two-layer or multi-layer tablets, two or more feed shoes may be installed in the molding machine, and the constituent materials for each layer may be filled into the die cavity from each feed shoe. If powder leaking from any of the feed shoes improperly enters the die cavity, the amount or ratio of the components in the molded product may fluctuate, potentially adversely affecting the quality of the molded product.

[0005] Therefore, leakage of powder outside the feed shoe must be avoided as much as possible. Of course, even the feed shoes of existing molding machines are designed to securely hold the sealing material to the bottom plate and to prevent any gaps from forming between the sealing material and the top surface of the table. However, the structure for assembling the sealing material to the bottom plate is complex and tends to have a large number of parts. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-027917 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention aims to appropriately prevent improper leakage of powder from a feed shoe used for powder filling, which is mounted on a rotary powder compression molding machine, using a simple configuration. [Means for solving the problem]

[0008] The present invention provides a rotary powder compression molding machine in which a die hole is provided that penetrates the table of a rotary disk, and an upper punch and a lower punch are slidably held above and below each die hole, and when the rotary disk is rotated horizontally and the die hole passes under the feed shoe, powder is filled into the die hole from the feed shoe, and when the pair of upper and lower punches pass between the upper roll and the lower roll, the powder filled in the die hole is compressed and molded to produce a molded product, wherein the feed shoe holds the powder to be filled into the die hole, and the rotational method of the movement of the die hole is on the bottom plate facing the upper surface of the table A powder compression molding machine was constructed comprising: a housing having a through-window formed therein for dropping in powder that expands in the direction; a sealing material located on the lower surface of the bottom plate, offset inward and outward along the radial direction perpendicular to the rotation direction from the through-window, protruding below the lower surface of the bottom plate and extending in the rotation direction; and a trimming plate located on the lower surface of the bottom plate, near the end of the through-window along the rotation direction, protruding below the lower surface of the bottom plate and expanding radially, and supporting the end of the sealing material between itself and the bottom plate.

[0009] Here, "powder" refers to an aggregate of minute particles, encompassing both aggregates of granules and other particles, and aggregates of powders smaller than granules. A mixture of multiple types of powders is also considered a powder. When a molded product is a pharmaceutical tablet, the main ingredient, excipients, lubricants, etc., are all powders, and a mixture of the main ingredient and other powders also falls under the category of a powder.

[0010] The above configuration effectively prevents improper leakage of powder from between the feed shoe and the table in a rotary powder compression molding machine. Because the end of the sealing material is supported by the bottom plate and the trimming plate of the feed shoe, the assembly structure of the sealing material is simplified, and the number of parts is reduced.

[0011] The sealing material, for example, has a base portion that abuts against or is close to the upper surface of the table, and a supported piece that extends from the end of the base portion in the direction of rotation and has a vertical dimension thinner than the base portion, and the supported piece is supported by the bottom plate and the scraping plate. By having the end of the base portion of the sealing material abut against the scraping plate in the direction of rotation, the scraping plate prevents displacement of the sealing material even if the sealing material is dragged by the rotating table, thereby preventing leakage of powder to the outside of the feed shoe.

[0012] If a groove is formed on the lower surface of the bottom plate at a position offset inward and outward from the through-window, and the groove is recessed upward and extends in the direction of rotation, and the sealing material is fitted into the groove, the sealing material can be attached to the bottom plate of the feed shoe more securely.

[0013] If an elastic body is embedded between the groove on the lower surface of the bottom plate and the sealing material, which presses the sealing material toward the upper surface of the table, the sealing material can be reliably brought into contact with the upper surface of the rotating table, preventing the powder from leaking out of the feed shoe.

[0014] If the seal material is provided with a backing plate that protrudes below the lower surface of the bottom plate, is located near the starting end of the through-window along the rotational direction and expands radially, and is also provided between it and the bottom plate to support the starting end of the seal material, the assembly structure of the seal material will be simplified at the starting end side as well, and the number of parts will be reduced. In addition, the backing plate itself will contribute to suppressing leakage of powder to the outside of the feed shoe. [Effects of the Invention]

[0015] According to the present invention, it is possible to appropriately prevent improper leakage of powder to the outside from the feed shoe for powder filling, which is mounted on a rotary powder compression molding machine, with a simple configuration. [Brief explanation of the drawing]

[0016] [Figure 1] A side cross-sectional view of a rotary powder compression molding machine according to one embodiment of the present invention. [Figure 2] Plan view showing the table and feed shoe of the turntable of the molding machine of the same embodiment. [Figure 3] Developed view showing the flow of the molding process of the molded product by the molding machine of the same embodiment and the vertical movement of the pestle following the rotation of the turntable. [Figure 4] Plan view showing the feed shoe mounted on the molding machine of the same embodiment. [Figure 5] Cross-sectional view taken along line I-I showing the feed shoe of the same embodiment. [Figure 6] Bottom view showing the feed shoe of the same embodiment. [Figure 7] Perspective view of the bottom plate of the feed shoe of the same embodiment as seen from below. [Figure 8] Exploded perspective view of the bottom plate member, contact plate, wear plate, elastic body and sealing material of the feed shoe of the same embodiment as seen from below. [Figure 9] Exploded perspective view of the contact plate, wear plate, elastic body and sealing material of the feed shoe of the same embodiment as seen from above. [Figure 10] Enlarged cross-sectional view taken along line II-II showing the region including the end portion of the sealing material in the feed shoe of the same embodiment.

Mode for Carrying Out the Invention

[0017] 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 "molding machine") A used for manufacturing a molded product in this embodiment will be described. As shown in FIG. 1, in the frame 1 of this molding machine A, a vertical shaft 2 serving as a rotating shaft is established, and a turntable 3 is attached to the upper part of the vertical shaft 2.

[0018] The rotary disk 3 rotates horizontally, i.e., spins, around the axis of the vertical shaft 2. The rotary disk 3 consists of a table (mortar disk) 31, an upper pestle holder 32, and a lower pestle holder 33. As shown in FIG. 2, the table 31 is substantially disc-shaped, and a plurality of mortar holes 4 are provided at predetermined intervals along the rotation direction D on its outer peripheral portion. Here, the table 31 (and the rotary disk 3 including the pestle holder 32 and the pestles 5 and 6) rotates counterclockwise in a plan view as represented by the arrow D in the figure. The mortar holes 4 penetrate the table 31 vertically. The table 31 may be divided into a plurality of plates. Also, instead of directly drilling the mortar holes 4 in the table 31 itself, a plurality of mortar members that are separate from the table 31 and detachable from the table 31 may be attached to the table 31, and mortar holes penetrating vertically are drilled in each of these mortar members.

[0019] As shown in FIGS. 1 and 3, above and below each mortar hole 4, an upper pestle 5 and a lower pestle 6 are arranged. The upper pestle 5 and the lower pestle 6 are held by the upper pestle holder 32 and the lower pestle holder 33, respectively, so that each can slide vertically with respect to the mortar hole 4. The pestle tip 53 of the upper pestle 5 enters and exits the mortar hole 4. The pestle tip 63 of the lower pestle 6 is always inserted into the mortar hole 4. The upper pestle 5 and the lower pestle 6 rotate horizontally, i.e., revolve, around the axis of the vertical shaft 2 together with the rotary disk 3 and the mortar holes 4.

[0020] A worm wheel 7 is attached to the lower end side of the vertical shaft 2. A worm gear Ten 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 and drives the rotary disk 3 and the pestles 5 and 6 connected to the vertical shaft 2 via the worm gear 10 and the worm wheel 7.

[0021] Powders that will be used as materials for compression molded products, such as pharmaceutical tablets, are fed from a powder supply device (not shown) into a hopper (or buffer tank) 19, and then supplied from the hopper 19 to feed shoes X (Xa, Xb). The powder supplied by the powder supply device to the molding machine A may be a mixture of several types of powders. When the molded product to be manufactured is a pharmaceutical tablet, the powder is a mixture of an active ingredient, excipients such as lactose, crystalline cellulose, and starch, and lubricants such as magnesium stearate and talc.

[0022] The powder is filled into each die cavity 4 of the table 31 from the feed shoe X. The feed shoe X (Xa, Xb), which is the filling device, is located on the outer circumference of the rotating table 31, in particular, directly above the rotational trajectory of the die cavity 4. As the table 31 rotates together with the turntable 3, the die cavity 4 is displaced relative to the feed shoe X. As shown in Figures 2 and 3, multiple feed shoes Xa, Xb can also be arranged in a single molding machine A.

[0023] As shown in Figures 2 and 3, on the orbital path of the pestles 5 and 6 around the axis of the vertical shaft 2, there are upper pre-pressure rolls 12 and 13, and upper main pressure rolls 14 and 15, which are positioned above and below the pestles 5 and 6, flanking them. The upper pre-pressure rolls 12 and 13, and the upper main pressure rolls 14 and 15, bias the upper and lower pestles 5 and 6 toward each other in order to compress the powder filled in the die cavity 4 from above and below with the tip surfaces of the pestle tips 53 and 63.

[0024] The upper pestle 5 and lower pestle 6 each have heads 51 and 61 that are pressed by the rolls 12, 13, 14, and 15, and bodies 52 and 62 that are smaller in diameter than the heads 51 and 61. The upper pestle holder 32 of the rotating disc 3 holds the body 52 of the upper pestle 5 so that it can slide up and down, and the lower pestle holder 33 holds the body 62 of the lower pestle 6 so that it can slide up and down. The tip portions 53 and 63 of the bodies 52 and 62 are even thinner than the rest of the body and have a diameter approximately equal to the inner diameter of the die hole 4, so that they can be inserted into the die hole 4. As the pestles 5 and 6 revolve, the rolls 12, 13, 14, and 15 approach the heads 51 and 61 of the pestles 5 and 6 and make contact with them by riding on top of them. Furthermore, rolls 12, 13, 14, and 15 push the upper pestle 5 downwards and the lower pestle 6 upwards. While rolls 12, 13, 14, and 15 are in contact with the flat surfaces on the pestles 5 and 6, the pestles 5 and 6 continuously apply constant pressure to the powder inside the die cavity 4.

[0025] Downstream from the pressurizing position by the main upper roll 14 and main lower roll 15, along the rotation direction D of the turntable 3 and punches 5 and 6, there is a collection point for the finished molded product. A damper (or scraper) 17 is installed at this collection point.

[0026] The vertical movement of the upper pestle 5 and lower pestle 6 is caused by cam rails R1, R2, R3, R4, and R5. Rails R1, R2, R3, R4, and R5 extend along the rotation direction D of the turntable 3 and the pestles 5 and 6, and engage with the heads 51 and 61 of the pestles 5 and 6, guiding and moving the pestles 5 and 6 up and down.

[0027] As shown in Figure 3, on the rotational trajectory of the head 51 of the upper punch 5, there is an upward rail (upward cam) R1 that lifts the upper punch 5 upstream of the damper 17 and pulls its punch tip 53 out of the die hole 4, and a downward rail (downward cam) R2 that pushes down the upper punch 5 upstream of the rolls 12 and 14 and inserts its punch tip 53 into the die hole 4 in preparation for subsequent powder compression.

[0028] On the rotational trajectory of the head 61 of the lower punch 6, there is a push-up rail R3 that lifts the lower punch 6 upstream of the damper 17 so that its punch tip 63 is at approximately the same height as the top surface of the table 31, a lowering device R4 that pulls down the lower punch 6 upstream of or near the first feed shoe Xa so that the volume of the die hole 4 above the punch tip 63 corresponds to the amount of powder to be filled into the die hole 4 from the feed shoe Xa, and a lowering device R5 that further pulls down the lower punch 6 upstream of or near the second feed shoe Xb so that the volume of the die hole 4 above the punch tip 63 corresponds to the amount of powder to be filled into the die hole 4 from the feed shoe Xb. In the latter half of the lowering device rail R5, the lower punch 6 is slightly pulled down so that the powder inside the die hole 4 after the amount has been adjusted does not spill out of the die hole 4 due to centripetal force, etc.

[0029] To give an overview of one example of the manufacturing process for a molded product, as shown in Figure 3, first, the lower punch 6, with its punch tip 63 inserted into the die cavity 4, descends to expand the internal volume of the die cavity 4 to the required size, and as the die cavity 4 passes directly below the first feed shoe Xa, powder is poured from the feed shoe Xa into the die cavity 4. Before filling the die cavity 4 with powder from the feed shoe Xa, a spraying device (not shown) that sprays a lubricant may spray and apply the lubricant to the inner circumferential surface of the die cavity 4, the upper surface of the punch tip 63 of the lower punch 6 inserted into the die cavity 4, and the lower surface of the punch tip 53 of the upper punch 5 positioned above the die cavity 4.

[0030] Next, the lower punch 6 descends further, expanding the internal volume of the die cavity 4 to the required size, and as the die cavity 4 passes directly beneath the second feed shoe Xb, powder is poured from the feed shoe Xb into the die cavity 4. This creates a two-layer structure within the die cavity 4, with the powder filled from the first feed shoe Xa forming the lower layer and the powder filled from the second feed shoe Xb forming the upper layer. The powder in the lower layer and the powder in the upper layer may differ in type, composition, and contained components, or they may be the same.

[0031] As shown in Figure 2, a nucleus insertion device may be installed between the first feed shoe Xa and the second feed shoe Xb along the rotation direction D of the table 31 and die hole 4. The nucleus insertion device is used in molding machine A when molding a nucleated product (a nucleated tablet containing a nucleus tablet or other inner nucleus, or a semiconductor integrated circuit chip (sometimes called an electronic device, IC tag, or RFID tag) etc., within a layer made of raw material powder). In this case, when the die hole 4, which has already been filled with powder by the first feed shoe Xa, passes near the insertion device, a nucleus is inserted into the die hole 4 from the insertion device. Then, when the die hole 4 reaches the vicinity of the second feed shoe Xb, additional powder is filled into the die hole 4 from the second feed shoe Xb to cover the nucleus.

[0032] However, the nuclear injection device is not an essential component. There is no limit to the number of feed shoes Xa and Xb installed on molding machine A; one unit is sufficient, or there can be three or more.

[0033] After filling the die cavity 4 with powder from the feed shoe X (Xa, Xb), as shown in Figure 3, the upper punch 5 descends, and the pre-pressing upper roll 12 and pre-pressing lower roll 13 press against the head 51 of the upper punch 5 and the head 61 of the lower punch 6, performing pre-compression by compressing the powder in the die cavity 4 with the punch tips 53 and 63 of both punches 5 and 6. Subsequently, the main compression upper roll 14 and main compression lower roll 15 press against the head 51 of the upper punch 5 and the head 61 of the lower punch 6, performing main compression by compressing the powder in the die cavity 4 with the punch tips 53 and 63 of both punches 5 and 6.

[0034] Finally, the lower punch 6 rises until the upper end surface of the punch tip 63 is at approximately the same height as the upper end of the die cavity 4, that is, the upper surface of the table 31, pushing the molded product inside the die cavity 4 out onto the table 31. The molded product that has left the die cavity 4 comes into contact with the damper 17 at the product discharge section 16 due to the rotation of the turntable 3 and is scraped off, and moves along the damper 17 towards the molded product chute 18.

[0035] Hereafter, additional information will be provided regarding each feed shoe X (Xa, Xb). In this embodiment, the feed shoe X is an agitating feed shoe that rotates a built-in agitating blade X1 to agitate the powder and drop it into the die hole 4. As shown in Figures 4 to 6, the feed shoe X mainly consists of a housing X2 that receives the powder supplied from the powder mixing and supplying device, one or more agitating blades X1 that rotate within the housing X2 and agitate the powder while dropping it from the housing X2 into the die hole 4 of the table 31, at least one motor (not shown) that outputs a driving force to rotate the agitating blades X1, and a transmission mechanism X3 that transmits the rotation of the motor's output shaft X4 to the shafts of each agitating blade X1.

[0036] The housing X2 is a flat enclosure-shaped structure with an internal space, formed by fixing a bottom plate member X22 to the lower part of the housing body X21. A powder inlet X211 for introducing powder into the housing X2 is provided on the upper surface of the housing body X21. The powder inlet X211 is connected to the hopper 19 of the molding machine A, and powder is supplied from the powder mixing and supply device to the feed shoe X via the hopper 19.

[0037] The bottom plate member X22 constitutes the bottom plate of the housing X2 and is a flat, dish-shaped member that closes off most of the internal space of the housing body X21 from below. The bottom plate member X22 has a window X221 that is roughly arc-shaped in plan view and penetrates the bottom plate member X22 vertically. The through window X221 is a drop opening (a supply opening for powder to the die hole 4) through which the powder to be filled into the die hole 4 of the table 31 of the molding machine A falls from inside the housing X2 toward the die hole 4. It extends along the rotation direction D of the table 31 and the die hole 4 so that in plan view it overlaps with the path through which the die hole 4 passes when the feed shoe X is positioned in the required position on the molding machine A.

[0038] The stirring blade X1 is a component in which multiple blades extend radially from a central hub in a plan view, and is housed in the internal space of the housing X2, and stirs the powder inside the housing X2 with its blades. The illustrated example feed shoe X is equipped with a pair of stirring blades X1, and each stirring blade X1 rotates horizontally around a vertical axis with the hub as the center of rotation.

[0039] The transmission mechanism X3 is a gearbox having multiple meshing gears. The output shaft X4 of the motor is fixed to one of the gears, the hub, which is the shaft of one stirring blade X1, is fixed to one of the gears, and the hub, which is the shaft of the other stirring blade X1, is fixed to one of the other gears, thereby transmitting the driving force output by one motor to both stirring blades X1. The gear train of the transmission mechanism X3 is located directly above the stirring blades X1 within the housing X2. The motor is located above the housing X2, and the output shaft X4, which extends downward, enters the housing X2 by passing through a shaft hole drilled in the upper surface of the housing X2 and connects to the gears.

[0040] The motor is a servo motor or the like, whose rotational speed can be arbitrarily controlled, and the control device is capable of knowing the magnitude of the load torque currently acting on the motor and the magnitude of the applied current. The rotational speed of each stirring blade X1 is determined by the rotational speed of the motor and the gear ratio of the gear train of the transmission mechanism X3. By adjusting the number of teeth on each gear in the gear train within the transmission mechanism X3, the ratio of the rotational speed of one stirring blade X1 to the rotational speed of the other stirring blade X1 can also be arbitrarily changed. Furthermore, by adjusting the number of gears interposed between the motor and each stirring blade X1, the rotation direction of each stirring blade X1 can also be arbitrarily changed. That is, one stirring blade X1 can be rotated in the opposite direction to the other stirring blade X1, and both stirring blades X1 can be rotated in the same direction.

[0041] The number of motors that drive the stirring blades X1 is not necessarily less than the number of stirring blades X1. The number of motors may be the same as the number of stirring blades X1. If multiple stirring blades X1 and the same number of motors are used, and the output shaft of each motor is connected to a hub that serves as the axis of each stirring blade X1, then each motor individually drives each stirring blade X1. This allows for individual changes to the rotation speed and direction of each stirring blade X1 through control of the rotation speed and direction of each motor. Furthermore, the number of stirring blades X1 within the feed shoe X is not limited to two; there may be three or more.

[0042] The powder supplied from the hopper 19 to the feed shoe X is agitated by the stirring blade X1 within the housing X2, and then falls from the through-window X221 in the bottom plate X22 of the housing X2 toward the table 31 of the molding machine A, filling the die cavity 4. However, not all of the powder that falls from the through-window X221 is filled into the die cavity 4, and excess powder may leak to the outside from between the feed shoe X and the table 31. To prevent such powder leakage, a sealing material X25, a scraping plate X26, and a backing plate X23 are attached to the underside of the bottom plate X22 of the housing X2 facing the top surface of the table 31.

[0043] As shown in Figures 6 to 10, the sealing material X25 has a base portion X251 that is roughly arc-shaped in plan view along the side edge of the through-window X221, and supported pieces X252 that extend from the upper edges at the start and end of the base portion X251, respectively. The vertical dimension of the supported piece X252 is thinner than the vertical dimension of the base portion X251. The base portion X251 and supported piece X252 of the sealing material X25 extend along the rotational direction D of the table 31 and die hole 4. There is a pair of sealing materials X25, and they are arranged in parallel on the inside and outside of the through-window X221 (along the radial direction perpendicular to the rotational direction D) on the lower surface of the bottom plate X22. As shown in Figures 5 and 10, the sealing material X25 protrudes below the lower surface of the bottom plate X22 and seals the gap between the lower surface of the bottom plate X22 and the upper surface of the table 31. The sealing material X25 prevents powder that has fallen through the through-window X221 from leaking out of the feed shoe X and spreading to parts of the table 31 other than the die holes 4.

[0044] On the lower surface of the base plate X22, recessed grooves X222 are pre-formed at positions offset inward and outward from the through-window X221, with the grooves extending upward along the rotational direction D of the table 31. Each sealing material X25 is fitted into these grooves X222. At this time, as shown in Figures 5 and 10, an elastic body X24 is embedded between the upper surface of the sealing material X25 and the bottom surface of the groove X222. The elastic body X24 is a wire or small-diameter tube made of a soft resin such as rubber, which has a roughly arc shape in plan view similar to the base of the sealing material X25. The elastic body X24 is compressed by the sealing material X25 and generates an elastic force, which pushes the sealing material X25 downward toward the table 31, causing the lower surface of the sealing material X25 to adhere tightly to the upper surface of the table 31.

[0045] The scraping plate X26 is positioned on the underside of the bottom plate X22 near the end of the through-window X221 along the rotational direction D of the table 31. The end X261 of the scraping plate X26 adjacent to the end of the through-window X221 extends more than the radial opening width of the through-window X221. The scraping plate X26 protrudes below the underside of the bottom plate X22 and seals the gap between the underside of the bottom plate X22 and the upper surface of the table 31. The scraping plate X26 also prevents powder that has fallen from the through-window X221 from leaking outside the feed shoe X and spreading to parts of the table 31 other than the die holes 4. In particular, the end X261 of the scraping plate X26 functions to scrape off any excess powder that is being filled from the feed shoe X into the die holes 4 of the table 31 as the table 31 rotates.

[0046] A notch X262 is formed on the upper surface of the end X261 of the trimming plate X26, recessing downwards. The supported piece X252 at the end of the sealing material X25 fits into this notch X262. That is, the supported piece X252 is placed in the notch X262. Then, the supported piece X252 of the sealing material X25 is supported between the lower surface of the base plate X22 and the upper surface of the end X261 of the trimming plate X26.

[0047] When the table 31 rotates, the sealing material X25 is dragged along the table 31. However, as shown in Figure 10, the end of the base X251 of the sealing material X25 comes into contact with and is tightly attached to the end X261 of the scraping plate X26 along the rotational direction D of the table 31, thereby suppressing the displacement of the sealing material X25.

[0048] The backing plate X23 is positioned on the underside of the bottom plate X22 near the starting end of the through-window X221 along the rotation direction D of the table 31. The backing plate X23 protrudes below the underside of the bottom plate X22 and seals the gap between the underside of the bottom plate X22 and the upper surface of the table 31. The backing plate X23 also prevents powder that falls from the through-window X221 from leaking out of the feed shoe X and spreading to parts of the table 31 other than the die holes 4.

[0049] Support pieces X231 extending to both sides are formed on both radial edges of the backing plate X26. The supported piece X252 at the starting end of the sealing material X25 is placed on these support pieces X231. The supported piece X252 of the sealing material X25 is supported between the lower surface of the base plate X22 and the upper surface of the support piece X231 of the backing plate X23.

[0050] The wear plate X26 and the backing plate X23 are each fixed to the underside of the bottom plate X22 of the housing X2 using bolts, screws, or other appropriate fasteners (not shown). These wear plate X26 and backing plate are detachable from the bottom plate X22 of the housing X2. The sealant X25 and elastic body X24 are also detachable from the bottom plate X22 of the housing X2. The sealant X25, elastic body X24, wear plate X26, and backing plate X23 can all be easily replaced if wear or other issues occur.

[0051] According to this embodiment, the sealing material X25 can be easily attached to the bottom plate X22 of the housing X2 of the feed shoe X. Moreover, the number of parts, including the trimming plate X26 and the backing plate X23, is reduced, and the structure is simple.

[0052] The sealing material X25 is supported not only by the groove X221 in the bottom plate X22 but also by the edge of the scraping plate X26. Therefore, even if the sealing material X25 is dragged on the table 31, it will not twist or become distorted, and the leakage of powder from the feed shoe X to the outside can be reliably prevented. Even when the feed shoe X is lifted away from the top surface of the table 31, the sealing material X25 will not fall off the feed shoe, and the sealing material X25 can be easily replaced in that state.

[0053] It should be noted that the present invention is not limited to the embodiments described in detail above. The specific configuration of each part can be modified in various ways without departing from the spirit of the present invention. [Explanation of Symbols]

[0054] A... Rotary powder compression molding machine 3… Rotating disc 31... Table 32, 33...Pinch holding part 4…Mortar hole 5, 6...Pestle X...Feedshoe X1... Agitation blade X2... Housing X22…Bottom plate X221...Through-window X222…concave groove X23... backing plate X231…Support piece X24...Elastic body X25...Sealant X251…Base X252…Supported piece X253...End of base X26...Strip plate X261...end X262... Notch

Claims

1. A rotary powder compression molding machine is provided with die holes that penetrate the table of a rotating disc, and an upper punch and a lower punch are slidably held above and below each die hole, and when the rotating disc is rotated horizontally and the die hole passes under the feed shoe, powder is filled into the die hole from the feed shoe, and when the pair of upper and lower punches pass between the upper roll and the lower roll, the powder filled in the die hole is compressed and molded to produce a molded product. The aforementioned feed shoe, A housing that holds the powder to be filled into the die cavity, and has a through-window formed in the bottom plate facing the upper surface of the table for dropping the powder, which expands in the rotational direction as the die cavity moves, A sealing material is located on the lower surface of the bottom plate, offset inward and outward along the radial direction perpendicular to the rotational direction from the through-window, protruding below the lower surface of the bottom plate and extending in the rotational direction, On the lower surface of the bottom plate, near the end of the through-window along the rotational direction, a trimming plate is provided between it and the bottom plate, which protrudes below the lower surface of the bottom plate and expands in the radial direction, and which supports the end portion of the sealing material. A powder compression molding machine equipped with the following.

2. The powder compression molding machine according to claim 1, wherein the sealing material has a base portion that abuts against or is close to the upper surface of the table, and a supported piece that extends from the end of the base portion in the direction of rotation and has a vertical dimension thinner than that of the base portion, and the supported piece is supported by the bottom plate and the trimming plate.

3. The powder compression molding machine according to claim 2, wherein the end of the base of the sealing material abuts against the scraping plate along the rotational direction.

4. On the lower surface of the bottom plate, recessed grooves are formed at positions offset inward and outward from the through-window, which are recessed upward and extend in the direction of rotation. The powder compression molding machine according to claim 1, wherein the sealing material fits into the groove.

5. The powder compression molding machine according to claim 4, wherein an elastic body is embedded between the groove on the lower surface of the bottom plate and the sealing material, which presses the sealing material toward the upper surface of the table.

6. The powder compression molding machine according to 1, 2, 3, 4, or 5, comprising a backing plate that protrudes below the lower surface of the bottom plate, is located near the starting end of the through-window along the rotational direction and expands radially, and supports the starting end of the sealing material between itself and the bottom plate.

7. A feed shoe is applied to a rotary powder compression molding machine, which has die holes that penetrate the table of a rotating disc, and an upper punch and a lower punch are slidably held above and below each die hole, and when the rotating disc is rotated horizontally and the die holes pass under the feed shoe, powder is filled into the die holes from the feed shoe, and when the pair of upper and lower punches pass between the upper roll and the lower roll, the powder filled in the die holes is compressed and molded to produce a molded product. A housing that holds the powder to be filled into the die cavity, and has a through-window formed in the bottom plate facing the upper surface of the table for dropping the powder, which expands in the rotational direction as the die cavity moves, A pair of sealing materials are located on the lower surface of the bottom plate, offset inward and outward along the radial direction perpendicular to the rotational direction from the through-window, protruding below the lower surface of the bottom plate and extending in the rotational direction, On the lower surface of the bottom plate, near the end of the through-window along the rotational direction, a trimming plate is provided between it and the bottom plate, which protrudes below the lower surface of the bottom plate and expands in the radial direction, and which supports the end portion of the sealing material. A feed shoe equipped with the following features.

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