A powder return structure for a tablet press

Abstract

This utility model relates to the technical field of tablet presses, and in particular to a powder return structure for tablet presses. The powder return structure of this utility model includes a powder return box with an extraction chamber connected to an extraction pipe. The powder return box has a first side and a second side facing away from each other. The first side has a first extraction port connected to the extraction chamber, used to absorb floating powder from the surface of the upper punch of the tablet press. The second side has a second extraction port connected to the extraction chamber, used to absorb floating powder from the surface of the material tray and the lower punch of the tablet press. By establishing a directional airflow channel, the dispersed floating powder is concentrated and drawn into the extraction chamber. The design of the extraction ports facing away from each other enables simultaneous removal of floating powder from multiple locations. The extraction chamber acts as a negative pressure source, connected to an external vacuum system through the extraction pipe to form a stable airflow, avoiding cross-contamination of floating powder during the tableting process and improving the consistency of tablet forming quality.

Description

Technical Field

[0001] This utility model relates to the technical field of tablet presses, and in particular to a powder return structure for tablet presses. Background Technology

[0002] As a core dosage form in the pharmaceutical, food, and chemical industries, the consistency of tablet quality directly affects the safety and efficacy of products. In industrial production, tablet presses are the core equipment for high-speed compression molding of powder materials. Through a die system, high pressure is applied to the powder filling the die holes to form tablets with a predetermined shape and density.

[0003] During tableting, the upper and lower punches compress the powder to form tablets. However, during this process, powder adheres to the surface of the punches, affecting the quality of tablets in subsequent compressions. Furthermore, fine flash powder is generated after tablet clearance, and its presence also affects the quality of tablets in the next compression. Utility Model Content

[0004] The purpose of this invention is to provide a powder return structure for tablet presses, which reduces the impact of flash powder and floating powder on the surface of the punch on the quality of tablets in the next compression.

[0005] To solve the above-mentioned technical problems, this utility model provides a powder return structure for a tablet press.

[0006] The present invention relates to a powder return structure for a tablet press, comprising a powder return box and an air extraction pipe disposed on the powder return box;

[0007] The powder return box is provided with an air extraction chamber, which is connected to the air extraction pipe;

[0008] The powder return box has a first side and a second side facing away from each other; the first side has a first air extraction port communicating with the air extraction chamber, the first air extraction port being used to absorb floating powder on the surface of the upper punch of the tablet press; the second side has a second air extraction port communicating with the air extraction chamber, the second air extraction port being used to absorb floating powder on the surface of the material tray and the surface of the lower punch of the tablet press.

[0009] Furthermore, the first air extraction port has a first flared structure.

[0010] Furthermore, the first side is provided with an inclined surface, and a first through hole communicating with the air extraction chamber is provided on the inclined surface. A cover plate is also provided on the inclined surface, and there is a gap between the inclined surface and the cover plate to form the first air extraction port and the first flared structure.

[0011] Furthermore, the second air extraction port has a second flared structure.

[0012] Furthermore, the second side is provided with a second through hole communicating with the air extraction chamber, and the second side is also provided with a groove extending from the edge of the second side to the second through hole. The cross-sectional area of ​​the groove gradually decreases from the edge of the second side to the second through hole to form the second flared structure.

[0013] Furthermore, the powder return box includes a first housing and a second housing that are fixedly connected, and the air extraction chamber is formed by the first housing and the second housing, with the first side located on the first housing and the second side located on the second housing.

[0014] Furthermore, the first housing and / or the second housing have grooves to enclose the air extraction chamber.

[0015] Furthermore, the powder return structure for the tablet press also includes a positioning pin and an adjusting screw. The second housing has a positioning hole and an adjusting hole. The positioning hole and the positioning pin are used to position the powder return structure for the tablet press. The adjusting hole and the adjusting screw are used to adjust the distance between the second housing and the material tray plane of the tablet press.

[0016] Furthermore, the powder return structure for the tablet press also includes a locking component, one end of which is threadedly connected to the second housing to lock the powder return structure for the tablet press onto the tablet press.

[0017] Furthermore, the second housing is made of engineering plastic.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] By establishing a directional airflow channel, dispersed floating powder is concentrated and drawn into the suction chamber. The back-to-back suction port design enables simultaneous removal of floating powder from multiple locations. The first suction port targets floating powder on the surface of the upper punch, while the second suction port simultaneously treats floating powder on the surfaces of the material tray and lower punch. The suction chamber acts as a negative pressure source, connected to an external vacuum system via a suction pipe to create a stable airflow, preventing cross-contamination of floating powder during tableting and improving the consistency of tablet forming quality. Optimized airflow path design reduces energy consumption while ensuring effective suction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of one embodiment of the powder return structure for a tablet press according to the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the powder return structure for a tablet press from another perspective;

[0022] Figure 3 for Figure 1 The main view of the powder return structure of the tablet press in the middle;

[0023] Figure 4 for Figure 3 A cross-sectional view of the powder return structure of the tablet press in the middle;

[0024] Figure 5 for Figure 1 A partial schematic diagram of the powder return structure used in conjunction with the tablet press.

[0025] Figure label:

[0026] 1. Toner return box;

[0027] 10. Evacuation chamber;

[0028] 20. First housing; 21. First air extraction port; 22. Inclined surface; 23. First through hole; 24. Cover plate;

[0029] 30. Second housing; 31. Second air extraction port; 32. Second through hole; 33. Settlement groove; 34. Positioning hole; 35. Adjustment hole;

[0030] 4. Extraction pipe;

[0031] 5. Locking components;

[0032] 6. Upper punch; 7. Material tray; 8. Lower punch. Detailed Implementation

[0033] The powder return structure for the tablet press of this utility model will be described below with reference to the schematic diagrams, which illustrate the preferred embodiments of this utility model. It should be understood that those skilled in the art can modify the utility model described herein while still achieving the advantageous effects of this utility model. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit this utility model. Based on the teachings of this specification, those skilled in the art can form new technical solutions through cross-combination of different implementation methods without creating technical contradictions. Such modifications should all be considered to fall within the protection scope of this patent.

[0034] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly.

[0037] For example, a "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "electrical connection" can refer to a direct electrical connection or an indirect electrical connection through an intermediate medium.

[0038] The present invention will be described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0039] The following is in conjunction with the instruction manual appendix. Figure 1 To be continued Figure 5 This paper introduces the powder return structure for tablet presses according to the present invention.

[0040] In some of these embodiments, such as Figure 1 and Figure 2 As shown, the powder return structure for the tablet press of this utility model includes a powder return box 1 and an air extraction pipe 4 disposed on the powder return box 1.

[0041] The powder return box 1 is provided with an air extraction chamber 10, which is connected to the air extraction pipe 4.

[0042] like Figure 3 , Figure 4 and Figure 5 As shown, the powder return box 1 has a first side and a second side facing away from each other; the first side has a first air extraction port 21 communicating with the air extraction chamber 10, and the first air extraction port 21 is used to absorb the floating powder on the surface of the upper punch 6 of the tablet press; the second side has a second air extraction port 31 communicating with the air extraction chamber 10, and the second air extraction port 31 is used to absorb the floating powder on the surface of the material tray 7 and the surface of the lower punch 8 of the tablet press.

[0043] By establishing a directional airflow channel, dispersed floating powder is concentrated and drawn into the suction chamber 10. The back-to-back suction port design enables simultaneous removal of floating powder from multiple locations. The first suction port 21 targets floating powder on the surface of the upper punch 6, while the second suction port 31 simultaneously treats floating powder on the surfaces of the material tray 7 and the lower punch 8. The suction chamber 10 acts as a negative pressure source, connected to an external vacuum system via the suction pipe 4 to form a stable airflow, avoiding cross-contamination of floating powder during tableting and improving the consistency of tablet forming quality. Optimized airflow path design reduces energy consumption while ensuring effective suction.

[0044] In some embodiments, the first air extraction port 21 has a first flared structure.

[0045] By setting the first flared structure, the air intake area of ​​the air extraction port is effectively increased, forming a more significant airflow diffusion effect under the same negative pressure conditions. The suction range can cover a wider area of ​​the surface of the punch rod 6 on the material tray, avoiding the residual floating powder in local areas due to the lack of airflow coverage. The floating powder is immediately captured by the airflow after it is generated, resulting in high floating powder suction efficiency and avoiding the floating powder rebound phenomenon caused by airflow turbulence.

[0046] Preferably, such as Figure 1 As shown, the first side is provided with an inclined surface 22, and the inclined surface 22 is provided with a first through hole 23 communicating with the air extraction chamber 10. The inclined surface 22 is also provided with a cover plate 24, and there is a gap between the inclined surface 22 and the cover plate 24 to form the first air extraction port 21 and the first flared structure.

[0047] Specifically, the inclined surface 22 can be a planar or curved surface, with an inclination angle ranging from 15° to 60°, preferably 30° to 45°. The cross-sectional shape of the first through hole 23 is also specified. The cover plate 24 can be made of metal or engineering plastic and is fixed above the inclined surface 22 by bolts or clips. The width of the gap gradually increases along the airflow direction, forming a tapered flared structure with a cone angle of 5° to 20°.

[0048] The inclined surface 22 and the cover plate 24 cooperate to form a gap structure with specific geometric parameters. Specifically, the inclined surface 22 provides a guiding foundation for airflow, the first through hole 23 realizes negative pressure transmission, and the gradually expanding gap space simultaneously realizes the functions of suction inlet and airflow rectification. Thus, under the action of negative pressure, the airflow velocity decreases and the streamline distribution tends to be more uniform when passing through the flared structure, effectively avoiding the turbulence phenomenon generated by the traditional straight-through air intake, enabling the floating powder to be sucked in a more stable flow field, resulting in high floating powder removal efficiency on the surface of the upper punch 6, and without interfering with the airflow during the tableting process.

[0049] In some embodiments, the second air extraction port 31 has a second flared structure.

[0050] By setting a second flared structure, the air intake area of ​​the air extraction port is effectively increased, forming a more significant airflow diffusion effect under the same negative pressure conditions. The suction range can cover the working area of ​​the material tray and the movement trajectory of the lower punch 8, avoiding the residual floating powder in local areas due to the lack of airflow coverage. The floating powder is immediately captured by the airflow after it is generated, resulting in high floating powder suction efficiency and avoiding the floating powder rebound phenomenon caused by airflow turbulence.

[0051] Preferably, such as Figure 2 As shown, the second side is provided with a second through hole 32 communicating with the air extraction chamber 10. The second side is also provided with a groove 33 extending from the edge of the second side to the second through hole 32. The cross-sectional area of ​​the groove 33 gradually decreases from the edge of the second side to the second through hole 32 to form the second flared structure.

[0052] Specifically, the trough 33 can adopt a cross-sectional change method with linear tapering, curved tapering, or stepped tapering. Linear tapering achieves linear reduction of cross-sectional area through sidewalls with a constant slope; curved tapering uses parabolic or exponential curve sidewalls to achieve nonlinear velocity optimization; stepped tapering achieves segmented cross-sectional area change through a multi-stage stepped structure. The outlet end of the trough 33 matches the diameter of the second through hole 32. The transition area between the second through hole 32 and the outlet of the trough 33 must maintain a smooth curved surface connection to avoid airflow turbulence.

[0053] The gradually narrowing airflow channel formed by the settling groove 33 and the second through hole 32 enhances the local airflow velocity. Specifically, when the suction chamber 10 generates negative pressure, the external airflow accelerates along the gradually narrowing path of the settling groove 33, forming a high-speed airflow zone at the second through hole 32. This acceleration effect makes it easier for floating powder particles to be captured by the airflow, while the low-pressure zone generated by the gradually narrowing structure expands the effective suction range, improving the efficiency of floating powder suction in the edge area of ​​the material tray 7 and the floating powder removal rate on the surface of the lower punch 8. In addition, the flared structure also optimizes the airflow distribution, reduces eddy current generation, and prevents floating powder from accumulating at the edge of the suction port.

[0054] In some of these embodiments, such as Figure 3 and Figure 4 As shown, the powder return box 1 includes a first housing 20 and a second housing 30 fixedly connected. The air extraction chamber 10 is surrounded by the first housing 20 and the second housing 30. The first side is located on the first housing 20 and the second side is located on the second housing 30.

[0055] Specifically, the first housing 20 and the second housing 30 can be fixedly connected by bolts, snap-fit ​​connections, or welding, with bolt connections facilitating disassembly and maintenance. As a preferred embodiment, the first housing 20 and the second housing 30 can be connected with a sealing ring to achieve an airtight connection. Specifically, the first housing 20 and the second housing 30 are fastened with bolts and a rubber sealing ring is provided at the mating surface. Further, the first housing 20 can be made of stamped metal sheet, and the second housing 30 can be made of injection molded engineering plastic, with stainless steel being the preferred material for the metal sheet to balance strength and corrosion resistance. The volume of the extraction chamber 10 can be adjusted by adjusting the groove depth of the first housing 20 or the second housing 30.

[0056] Modular design is achieved through a split-shell structure, where the first shell 20 integrates the powder recovery function of the upper punch 6, and the second shell 30 integrates the powder recovery function of the material tray 7 and the lower punch 8. This not only simplifies the manufacturing complexity of individual components but also facilitates independent maintenance or replacement for different functional areas. Furthermore, the modular design allows for the use of different materials or processes in manufacturing the first shell 20 and the second shell 30; for example, the second shell 30 can be made of wear-resistant engineering plastic to reduce frictional wear with the material tray.

[0057] In some of these embodiments, such as Figure 4 As shown, the first housing 20 and / or the second housing 30 have grooves to form the air extraction chamber 10.

[0058] Specifically, the groove can be provided on the inner surface of the first housing 20, and a closed suction chamber 10 is formed by the cooperation of the planar portion of the second housing 30 with the groove; alternatively, the groove can also be provided on the inner surface of the second housing 30, and a closed suction chamber 10 is formed by the cooperation of the planar portion of the first housing 20 with the groove. As a preferred embodiment, the groove can also be provided on the inner surfaces of both the first housing 20 and the second housing 30, with the two grooves arranged opposite each other to form a complete suction chamber 10. The cross-sectional shape of the groove can be rectangular, trapezoidal, or other suitable shapes, with a trapezoidal cross-section being beneficial for improving structural strength. The depth of the groove can be adjusted according to the required volume of the suction chamber 10.

[0059] The modular construction of the suction chamber 10 is achieved through a split shell structure. The combined design of the first shell 20 and the second shell 30 simplifies the manufacturing process and avoids complex one-piece molding. The use of grooves allows for precise control of the shape and size of the suction chamber 10, ensuring a stable suction effect.

[0060] In some of these embodiments, such as Figure 2 As shown, the powder return structure for the tablet press also includes a positioning pin and an adjusting screw. The second housing 30 has a positioning hole 34 and an adjusting hole 35. The positioning hole 34 and the positioning pin are used to position the powder return structure for the tablet press. The adjusting hole 35 and the adjusting screw are used to adjust the distance between the second housing 30 and the material tray plane of the tablet press.

[0061] Specifically, the locating pin can be a cylindrical pin or a tapered pin, with its diameter forming a transition fit or a small clearance fit with the locating hole 34 to ensure axial positioning accuracy. The adjusting screw can use standard thread specifications, such as M4 or M5 fine threads, with a thread engagement length of not less than 5mm to ensure adjustment stability. The adjusting hole 35 can be designed as a threaded through hole or a threaded blind hole, forming a threaded pair with the adjusting screw. The locating hole 34 can be set as a single hole or a symmetrically distributed double hole structure; the double hole structure can further improve positioning reliability. The head of the adjusting screw can be designed with common drive forms such as internal hexagon, Phillips head, or slotted head, facilitating operation with standard tools.

[0062] The axial positioning of the powder return structure is precisely achieved through the engagement of the positioning pin and the positioning hole 34, eliminating installation position deviations. Stepless vertical adjustment is achieved through the engagement of the adjusting screw and the adjusting hole 35, allowing precise control of the distance between the second housing 30 and the material tray plane. The two systems work together, ensuring both positioning accuracy during installation and adjustable working distance, maintaining the optimal working distance between the air extraction port, the punch, and the material tray. Adjustment requires no disassembly of parts; distance adjustment is achieved simply by turning the screw, significantly improving the maintainability and ease of operation of the equipment.

[0063] In some of these embodiments, such as Figure 2 As shown, the powder return structure for the tablet press also includes a locking member 5. One end of the locking member 5 is threadedly connected to the second housing 30 to lock the powder return structure for the tablet press onto the tablet press.

[0064] Specifically, the locking component 5 can be a standard fastener such as a bolt, screw, or threaded rod. Threaded connection methods include, but are not limited to: direct connection via a machined internal threaded hole in the second housing 30; connection via a welded nut or press-fitted threaded bushing; and a composite connection structure using a double-ended stud and nut. The material of the locking component 5 is preferably stainless steel or alloy steel to meet strength and corrosion resistance requirements. As a preferred embodiment, an anti-loosening washer can be provided at the end of the locking component 5 to enhance its anti-loosening performance under vibration.

[0065] In some embodiments, the second housing 30 is made of engineering plastic.

[0066] The range of engineering plastics to be selected includes polyoxymethylene (POM), polyamide (PA), or polyetheretherketone (PEEK), with POM being a preferred embodiment due to its combination of high rigidity and wear resistance. The second shell 30 can be formed by injection molding or machining. During injection molding, the melt temperature must be controlled within the range of 200-300°C to ensure dimensional stability.

[0067] By replacing traditional metal materials with engineering plastics, the wear resistance and corrosion resistance of engineering plastics make them less prone to wear from contact with metal trays. In addition, the vibration-absorbing properties of engineering plastics can reduce vibration noise during equipment operation.

[0068] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A powder return structure for a tablet press, characterized in that, It includes a powder return box (1) and an air extraction pipe (4) disposed on the powder return box (1); The powder return box (1) is provided with an air extraction chamber (10), which is connected to the air extraction pipe (4); The powder return box (1) has a first side and a second side facing away from each other; the first side has a first air extraction port (21) communicating with the air extraction chamber (10), the first air extraction port (21) being used to absorb the floating powder on the surface of the upper punch (6) of the tablet press; the second side has a second air extraction port (31) communicating with the air extraction chamber (10), the second air extraction port (31) being used to absorb the floating powder on the surface of the material tray (7) and the surface of the lower punch (8) of the tablet press.

2. The powder return structure for a tablet press according to claim 1, characterized in that, The first air extraction port (21) has a first flared structure.

3. The powder return structure for a tablet press according to claim 2, characterized in that, The first side is provided with an inclined surface (22), and the inclined surface (22) is provided with a first through hole (23) communicating with the air extraction chamber (10). The inclined surface (22) is also provided with a cover plate (24). There is a gap between the inclined surface (22) and the cover plate (24) to form the first air extraction port (21) and the first flared structure.

4. The powder return structure for a tablet press according to claim 1, characterized in that, The second air extraction port (31) has a second flared structure.

5. The powder return structure for a tablet press according to claim 4, characterized in that, The second side is provided with a second through hole (32) communicating with the air extraction chamber (10). The second side is also provided with a groove (33) extending from the edge of the second side to the second through hole (32). The cross-sectional area of ​​the groove (33) gradually decreases from the edge of the second side to the second through hole (32) to form the second flared structure.

6. The powder return structure for a tablet press according to claim 1, characterized in that, The powder return box (1) includes a first housing (20) and a second housing (30) fixedly connected. The air extraction chamber (10) is surrounded by the first housing (20) and the second housing (30). The first side is located on the first housing (20) and the second side is located on the second housing (30).

7. The powder return structure for a tablet press according to claim 6, characterized in that, The first housing (20) and / or the second housing (30) have grooves to enclose the air extraction chamber (10).

8. The powder return structure for a tablet press according to claim 6, characterized in that, The powder return structure for the tablet press also includes a positioning pin and an adjusting screw. The second housing (30) has a positioning hole (34) and an adjusting hole (35). The positioning hole (34) and the positioning pin are used to position the powder return structure for the tablet press. The adjusting hole (35) and the adjusting screw are used to adjust the distance between the second housing (30) and the material tray plane of the tablet press.

9. The powder return structure for a tablet press according to claim 6, characterized in that, The powder return structure for the tablet press also includes a locking member (5), one end of which is threadedly connected to the second housing (30) to lock the powder return structure for the tablet press onto the tablet press.

10. The powder return structure for a tablet press according to claim 6, characterized in that, The second housing (30) is made of engineering plastic.

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