Abstract:
In order to achieve reduction of a space occupied in a plant for manufacturing pharmaceutical tablets or the like, there is provided a compression molding machine that includes a table, an upper punch and a lower punch, a molded product collection mechanism, a molded product reservoir, and a housing for accommodating a connection end of an air convey path connected to the molded product reservoir. In this configuration, there is no need to additionally provide a dust removing device or a lifter outside the machine.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a compression molding machine that compresses a powdery material to mold a pharmaceutical tablet, a food product, an electronic component, or the like. 
     2. Description of the Related Art 
     There has been known a compression molding machine in which die holes are provided so as to penetrate a table in a vertical direction, and an upper punch and a lower punch are retained above and below each of the die holes so as to be slidable in the vertical direction, so that a powdery material filled in each of the die holes is subject to tableting so as to be compressed and molded (refer to Japanese Unexamined Patent Publication No. 2010-023083, for example). 
     When a product molded into a tablet by such a compression molding machine is taken out, dust of an excessive powdery material, a lubricant, or the like may adhere to a surface of the molded product. Even in a case where such dust does not adhere to a surface of the molded product, the dust is discharged together with the molded product. In order to remove such dust from the molded product, there are cases of using a dust removing device for separating dust from a molded product that is being conveyed by pressurized air and collecting the separated dust (refer to Japanese Patent No. 4315905, for example). 
     The dust removing device described in Japanese Patent No. 4315905 also functions as a lifter for lifting upward molded products that are discharged from the compression molding machine. Such a configuration enhances usability in feeding the molded products into one of devices for performing various subsequent processes including classifying, coating (such as film coating and sugar coating), and packaging (such as canning) the molded products that have been lifted upward. 
     The dust removing device described above or a lifter not having such a powder removing function is provided outside the compression molding machine. Accordingly, such a device occupies a certain necessary space in a plant. 
     SUMMARY OF THE INVENTION 
     In view of the above circumstances, it is a desired object of the present invention to achieve reduction of a space occupied in a plant. 
     According to the present invention, a compression molding machine includes: a table having at least one die hole penetrating in a vertical direction; paired upper and lower punches each having a tip for sliding in the die hole to compress and mold a powdery material filled in the die hole; a molded product collection mechanism for collecting a molded product extracted from the die hole in the table; a molded product reservoir for temporarily reserving the molded product collected by the molded product collection mechanism; a convey path connected to the molded product reservoir so as to allow the molded product temporarily reserved to be conveyed therealong; and a housing for accommodating the table, the upper punch, the lower punch, the molded product collection mechanism, the molded product reservoir, and a connection end of the convey path, the connection end being connected to the molded product reservoir. Herein, a powdery material and dust each contain collective solid fine substances, and conceptually include a so-called granular material or a powdered substance smaller than particles. In the above configuration, there is no need to additionally provide a dust removing device or a lifter outside the machine, which realizes reduction in space. 
     Preferably, the compression molding machine further includes a gas supply device for supplying air into the convey path. In this configuration, the molded product can be conveyed in the convey path by means of air. The convey path allows the molded product to be conveyed by means of air as well as allows dust adhering to the molded product to be removed. 
     Further, preferably, the compression molding machine further includes a turning device for turning the convey path about the connection end connected to the molded product reservoir. In this configuration, it is possible to adjust the height of a molded product discharge end provided opposite to the connection end of the convey path. The height of the discharge end can be arbitrarily adjusted in accordance with presence of a subsequent process or details thereof. 
     The convey path is preferably turnable in a range of angles from a substantially horizontal state to a substantially vertical state. 
     Further, the convey path may be configured to be extensible. 
     The convey path is preferably provided with a molded product discharge end opposite to the connection end, and the discharge end is located in the housing. In the above configuration, the convey path can be accommodated in the housing in a case where further reduction in space is required or in a case where the compression molding machine itself is moved. 
     The collection mechanism may be provided, for example, with a molded product chute for allowing the molded product extracted from the die hole to fall from a upper surface of the table. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a vertical sectional view of a main body of a compression molding machine according to an embodiment of the present invention; 
         FIG. 2  is a plan view of a main part in the main body of the compression molding machine according to the embodiment; 
         FIG. 3  is a view of the cylindrical projection showing a relationship between punches and rolls in the main body of the compression molding machine according to the embodiment; 
         FIG. 4  is a front view schematically showing an entire configuration of the compression molding machine according to the embodiment; 
         FIG. 5  is a front view schematically showing another entire configuration of the compression molding machine according to the embodiment; 
         FIG. 6  is a front view schematically showing still another entire configuration of the compression molding machine according to the embodiment; and 
         FIG. 7  is a front view schematically showing an entire configuration of a compression molding machine according to a modification of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Described below is an embodiment of the present invention with reference to the drawings. A compression molding machine according to the present embodiment includes a so-called rotary tableting machine and a dust removing device provided integrally with each other. The compression molding machine according to the present embodiment includes a table  3   a , paired upper and lower punches  5  and  6 , a powdery material supply mechanism, a molded product collection mechanism, a molded product reservoir  20 , a convey path  21 , and a housing  1 . The table  3   a  is provided with at least one die hole  4  that penetrates in a vertical direction. The paired upper and lower punches  5  and  6  are located above and below each die hole  4 . The powdery material supply mechanism includes a feed shoe  16  that fills a powdery material into each die hole  4 . The molded product collection mechanism collects, from the table  3   a , a molded product obtained by compressing and tableting the powdery material in the die hole  4 . The molded product reservoir  20  temporarily reserves the collected molded product. The convey path  21  allows the molded product reserved in the molded product reservoir  20  to be conveyed therealong by means of air as well as causes dust adhering to the molded product to be removed therefrom. The housing  1  accommodates the table  3   a , the punches  5  and  6 , the powdery material supply mechanism, the molded product collection mechanism, the molded product reservoir  20 , the convey path  21 , and the like. 
       FIGS. 1 to 3  each show the compression molding machine. Specifically, the housing  1  of the compression molding machine is configured by a frame  1   a  as a base, an outer casing  1   b  that surrounds, from every lateral direction, an internal space above the frame  1   a , and a top plate  1   c  that closes the internal space from above. There is provided an upright shaft  2  that stands in the internal space and functions as a rotary shaft, and a turret  3  is attached to a connection portion  2   a  that is located at an upper portion of the upright shaft  2 . 
     The turret  3  horizontally rotates about the upright shaft  2 , more specifically, spins. The turret  3  is configured by the table (die disc)  3   a , an upper punch retaining portion  3   b , and a lower punch retaining portion  3   c . As shown in  FIG. 2 , the table  3   a  has a substantially circular disc shape, and a plurality of die holes  4  are provided in an outer peripheral portion thereof so as to be aligned in a direction of rotation and be spaced apart from each other at predetermined intervals. The die holes  4  each penetrate the table  3   a  in the vertical direction. The table  3   a  may be composed of a plurality of divided plates. Instead of the die holes  4  provided directly in the table  3   a , a plurality of die members may be provided separately from the table  3   a  so as to be detachably attached to the table  3   a . In this case, the die members are each provided with a die hole that penetrates in the vertical direction. 
     The upper punch  5  and the lower punch  6  are retained above and below corresponding one of the die holes  4 , by the upper punch retaining portion  3   b  and the lower punch retaining portion  3   c , so as to be individually slidable in the die hole  4  in the vertical direction. Each upper punch  5  has a tip  53  that enters and exits the corresponding die hole  4 . Each lower punch  6  has a tip  63  that is always inserted in the corresponding die hole  4 . The upper punch  5  and the lower punch  6  horizontally rotate about the upright shaft  2  together with the turret  3 , more specifically, revolve. 
     The upright shaft  2  is provided, at the lower end, with a worm wheel  7 . The worm wheel  7  meshes with a worm gear  10 . The worm gear  10  is fixed to a gear shaft  9  that is driven by a motor  8 . Drive power outputted from the motor  8  is transmitted to the gear shaft  9  by way of a belt  11 , so as to drive to rotate the upright shaft  2  by way of the worm gear  10  and the worm wheel  7 , and further to rotate the turret  3  as well as the punches  5  and  6 . 
     A shown in  FIGS. 2 and 3 , a pre compression upper roll  12 , a pre compression lower roll  13 , a main compression upper roll  14 , and a main compression lower roll  15  are provided on orbits of the punches  5  and  6  that revolve about the upright shaft  2 . The pre compression upper roll  12  and the pre compression lower roll  13 , as well as the main compression upper roll  14  and the main compression lower roll  15 , are respectively paired in the vertical direction so as to sandwich the punches  5  and  6 . The pre compression upper roll  12  and the pre compression lower roll  13 , as well as the main compression upper roll  14  and the main compression lower roll  15 , respectively bias the upper and lower punches  5  and  6  to bring the upper and lower punches  5  and  6  close to each other, so that the tips  53  and  63  compress from above and below the powdery material, which is filled in each of the die holes  4  by the feed shoe  16 . 
     The upper punch  5  and the lower punch  6  have head portions  51  and  61  that are pressed by the rolls  12 ,  13 ,  14 , and  15 , and shaft portions  52  and  62  that are smaller in diameter than the head portions  51  and  61 , respectively. The shaft portions  52  and  62  each have a distal end of a diameter smaller than remaining portions and substantially equal to the inner diameter of the die hole  4 , so as to be inserted into the die hole  4 . The punches  5  and  6  revolve to bring the rolls  12 ,  13 ,  14 , and  15  close to the head portions  51  and  61  of the punches  5  and  6 . The rolls  12 ,  13 ,  14 , and  15  move to step onto the head portions  51  and  61  and come into contact therewith. Further, the rolls  12 ,  13 ,  14 , and  15  roll over the head portions  51  and  61  and are displaced in the horizontal direction, during which pressing downward each upper punch  5  and pressing upward each lower punch  6 , respectively. While the rolls  12 ,  13 ,  14 , and  15  are in contact with top flat surfaces of the punches  5  and  6 , the punches  5  and  6  apply constant pressure onto the powdery material in the corresponding die hole  4 . 
     A product unloading portion  17  is provided ahead, in the directions of rotation of the turret  3  and the punches  5  and  6 , of the position where the main compression upper roll  14  and the main compression lower roll  15  apply pressure. At the product unloading portion  17 , the lower punch  6  ascends until the end surface of the tip  63  of the lower punch  6  reaches the height substantially same as that of the upper end of the die hole  4 , in other words, the upper surface of the table  3   a . The lower punch  6  then pushes the molded product out of the die hole  4 . 
     The product unloading portion  17  is provided with a guide member  18  that guides the molded product pushed out of the die hole  4 . The molded product extracted from the die hole  4  is brought into contact with the guide member  18  due to the rotation of the turret  3 , and is shifted along the guide member  18  toward a molded product chute  19  that is located at a position where molded products are collected. The guide member  18  may be replaced with an air spray device or the like. The air spray device blows the molded product pushed out of the die hole  4  toward the molded product chute  19 . The molded product chute  19  allows the molded product extracted from the die hole  4  to fall from the upper surface of the table  3   a . Accordingly, in the present embodiment, the guide member  18  (replaceable with an air spray device or the like) and the molded product chute  19  configure the molded product collection mechanism. 
     The molded product fallen along the molded product chute  19  is temporarily reserved in the molded product reservoir  20 . The molded product reserved in the molded product reservoir  20  is conveyed along the convey path  21 , which also serves as a dust removing device, and exits the compression molding machine. The convey path  21  has a substantially cylindrical shape, and is connected to the molded product reservoir  20 . Alternatively, the convey path  21  may be configured to be extensible. 
     The convey path  21  has a connection end that is connected, by way of a tube  22 , to an air compressor  26  as an exemplary gas supply device. Pressurized air discharged from the air compressor  26  flows in the tube  22  and is then blown out of the tube  22  in a direction along the inner peripheral surface of the convey path  21 , in other words, in a direction about an axis extending along the convey path  21 . As a result, the molded product reservoir  20  is brought into a vacuum state. Accordingly, air and the molded product are sucked from the molded product reservoir  20  into the convey path  21 . The air and the molded product thus having been sucked spirally whirl along the inner peripheral surface of the convey path  21  and flow away from the connection end. The gas supplied from the gas supply device may be air or any gas that does not affect products, such as nitrogen or oxygen. 
     The convey path  21  has a discharge end located opposite to the connection end. This discharge end is closed by a lid  24  that is provided with a large number of holes having a diameter smaller than that of the molded product. The lid has an outer surface connected to a dust collector (not shown) with a bendable duct  23  being interposed therebetween. Furthermore, the peripheral wall in the vicinity of the discharge end is provided with a molded product discharge port  25 . The molded product reserved in the molded product reservoir  20  and dust adhering to the molded product are flown by air discharged from the air compressor  26 , and spirally whirl to reach the vicinity of the discharge end. During this process, the dust adhering to the molded product is separated from the molded product. Negative pressure generated by the dust collector causes the dust to pass through the holes provided in the lid  24  to be sucked into the duct  23 . However, the molded product separated from the dust cannot pass through any one of the holes in the lid  24 , and is discharged out of the convey path  21  through the molded product discharge port  25 . 
     In the present embodiment, the convey path  21  can be turned upward and downward about the connection end by a turning device  27 . Accordingly, it is possible to change the heights of the discharge end as well as the molded product discharge port  25 . As shown in  FIG. 4 , in a case where the convey path  21  is provided substantially in the vertical direction, the discharge end and the molded product discharge port  25  are located in the housing  1 , more specifically, laterally inside the outer casing  1   b . In this case, the molded product may be taken upward out of a port provided in the top plate  1   c . As shown in  FIG. 5 , in another case where the convey path  21  is provided to be inclined, the discharge end and the molded product discharge port  25  can be exposed outside the housing  1 , more specifically, laterally outside the outer casing  1   b .  FIG. 5  also illustrates a known metal detector  0 , which senses and selects any product including a metal piece out of the molded products exiting the molded product discharge port  25 , so that products thus selected are collected in a defective product collecting container. As shown in  FIG. 6 , in still another case where the convey path  21  is turned so as to be provided substantially in the horizontal direction, the discharge end and the molded product discharge port  25  can be located at lower positions. In any one of the above cases, the connection end of the convey path  21  is located in the housing  1 . 
     The turning device  27  may be arbitrarily configured as long as being capable of turning the convey path  21 . Nevertheless, the turning device  27  preferably includes a position detection mechanism and a position control mechanism, so as to be capable of stopping the turning convey path  21  at a desired position. Alternatively, the turning device  27  may be configured to manually turn the convey path  21 . Still alternatively, the turning device  27  may be configured to stop the turning convey path  21  at a desired position with use of a positioning pin or the like. 
     In the present embodiment, the compression molding machine includes the table  3   a  provided with at least one die hole  4  that penetrates in the vertical direction, the paired upper and lower punches  5  and  6  that respectively have the tips slidable in the corresponding die hole  4  so as to compress and mold the powdery material filled in the die hole  4 , the molded product collection mechanism that collects the molded product extracted from the die hole  4  in the table  3   a , the molded product reservoir  20  that temporarily reserves the molded product collected by the molded product collection mechanism, the convey path  21  that is connected to the molded product reservoir  20 , allows the molded product temporarily reserved in the molded product reservoir  20  to be conveyed therealong by means of air, as well as causes dust adhering to the molded product to be removed, and the housing  1  that accommodates the table  3   a , the upper punch  5  and the lower punch  6 , the molded product collection mechanism, the molded product reservoir  20 , and the connection end of the convey path  21  to be connected with the molded product reservoir  20 . Accordingly, there needs no additional provision of a dust removing device or a lifter outside the machine, and reduction is achieved in terms of the space occupied by such a device. 
     The convey path  21  is turnable about the connection end that is connected to the molded product reservoir  20 , so as to adjust the height of the molded product discharge end, which is located opposite to the connection end. In this configuration, the height of the discharge end can be arbitrarily adjusted in accordance with presence of a subsequent process or details thereof. 
     The convey path  21  is turnable in a range of angles from a substantially horizontal state to a substantially vertical state. Therefore, the discharge end of the convey path  21  can be largely exposed from the housing  1  when necessary. 
     The molded product discharge end, which is provided opposite to the connection end of the convey path  21 , can be located inside the housing  1 . Accordingly, the convey path  21  can be completely accommodated in the housing  1  in a case where further reduction in space is required or in a case where the compression molding machine itself is moved. 
     The collection mechanism is provided with the molded product chute  19  that allows the molded product extracted from the die hole  4  to be fall from the disc surface of the table  3   a . Therefore, the collection mechanism is not complicated in its configuration, which facilitates its maintenance work. 
     It is noted that the present invention is not limited to the embodiment detailed above. In particular, the convey path  21 , which allows the molded products reserved in the molded product reservoir  20  to be conveyed therealong, is not limited to an air convey path. As shown in  FIG. 7 , in place of the air convey path  21 , the compression molding machine may be equipped with a convey path  21 X that has a mechanical convey structure for conveying the molded products toward (the molded product discharge port  25  of) the discharge end by means of a bucket lifter, a belt conveyer, or a member reciprocating in a tube path. The convey path  21 X is generally provided with no function of removing dust that adheres to a molded product. 
     The convey path  21 X in this configuration is also turnable about the connection end that is connected to the molded product reservoir  20 . Therefore, it is possible to adjust the height of the discharge end that is located opposite to the connection end. As shown in  FIG. 7 , the molded product discharge end of the convey path  21 X can be located inside the housing  1 . The compression molding machine preferably includes the turning device  27  that turns the convey path  21 X in the range of the angles from a substantially horizontal state to a substantially vertical state. However, the convey path  21 X may not be necessarily turnable in the range of the angles from a substantially horizontal state to a substantially vertical state, due to the configuration of the convey structure (such as the bucket lifter and the belt conveyer). 
     The compression molding machine according to the embodiment described above is configured as a rotary tableting machine in which the table  3   a  and the punches  5  and  6  revolve. Alternatively, the compression molding machine may be configured as a tableting machine in which the table  3   a  and the punches  5  and  6  do not revolve but the feed shoe  16  does, a tableting machine of (a non rotary type but) a so-called vertical (reciprocating) type, or the like. 
     In the molded product collection mechanism, the molded product chute  19  may be replaced with a circular disc conveyer or a belt conveyer that conveys the molded products. Alternatively, such a circular disc conveyer or a belt conveyer may be provided in addition to the molded product chute  19 . 
     The specific configurations of other portions may be modified in various ways as long as not departing from the object of the present invention.