Rubber piston compression molding machine for pre-filled syringe and compression molding method of rubber piston compression molding machine

Abstract

The invention relates to the technical field of rubber piston compression molding, in particular to a rubber piston compression molding machine for a pre-filled syringe and a compression molding method of the rubber piston compression molding machine. The compression molding device comprises a workbench, a compression molding mold is arranged on the upper side of the workbench and comprises an upper mold and a lower mold, and a plurality of compression molding mechanisms are arranged in the upper mold. After compression molding of a piston is completed through the compression molding mold and the upper mold and the lower mold are separated, the moving mechanism can relieve downward pressing of the compression molding mechanism so that the compression molding mechanism can move upwards, in the upward moving process of the compression molding mechanism, the compression molding mechanism can drive the material pushing mechanism to move, and the moving material pushing mechanism moves upwards along with the compression molding mechanism and moves downwards along with the compression molding mechanism. When the piston is pressed, the edge of the piston arranged on the conical block in a sleeving mode is pushed outwards and downwards through stretching of the clamping groove ring block and the straight rod, then the compression molding mechanism moves upwards to drive the piston to extrude the bottom of the upper mold, the piston falls off from the compression molding mechanism, and therefore the trouble of manually removing the piston is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber piston compression molding, and specifically, to a rubber piston compression molding machine for pre-filled syringes and a compression molding method thereof. Background Art

[0002] A pre-filled syringe is a syringe pre-filled with medicine. The needle of the pre-filled syringe is designed precisely, the piston system adopts special materials and designs, the syringe design focuses on user experience, has a simple and intuitive operation mechanism, which is convenient for medical staff to quickly master the usage method. Medical-grade glass is a commonly used material for pre-filled syringes because of its good chemical stability and suitability for storing medicine. Polypropylene and polycarbonate are commonly used medical-grade plastics for making the barrel and piston of the syringe.

[0003] Currently, when manufacturing the piston, compression molding or injection molding can be used. When making the piston, an installation cavity is arranged inside the piston, and a clamping groove is arranged in the installation cavity to facilitate the connection between the piston and the push rod. When currently compression molding the piston, the rod for pressing out the clamping groove itself does not move. After the piston is compression molded, it is necessary to manually remove the piston sleeved on the rod, which reduces the automation degree of the compression molding machine. At the same time, during the process of piston compression molding, because the rod first contacts the rubber for compression molding the piston, most of the rubber in the mold for making the piston will be extruded out. After the piston is compression molded, the extruded rubber in the mold will form a film. When removing the piston from the mold, the piston and the film are removed together, so that a large amount of rubber cannot be used to make the piston but forms a film, resulting in waste of rubber. In order to improve the automation degree of the compression molding machine and reduce the waste of rubber during the compression molding process, this solution provides a rubber piston compression molding machine for pre-filled syringes and a compression molding method thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a rubber piston compression molding machine for pre-filled syringes and a compression molding method thereof to solve the problems raised in the above background art.

[0005] To achieve the above object, one of the objects of the present invention is to provide a rubber piston compression molding machine for pre-filled syringes, which includes a workbench. An installation frame is fixedly installed on the upper side of the workbench. A compression molding die is arranged on the upper side of the workbench. The compression molding die includes an upper die and a lower die. A number of compression molding mechanisms are arranged inside the upper die, and a pushing mechanism is arranged on each compression molding mechanism. A moving mechanism for driving the upper die to move up and down is arranged on the upper side of the compression molding die. The lower die is arranged on the upper side of the workbench. The moving mechanism drives the upper die to approach the lower die. During the closing process of the upper die and the lower die, the moving mechanism pushes the compression molding mechanism downward. During the downward movement of the compression molding mechanism, the pushing mechanism is received into the compression molding mechanism. When the compression molding is completed, the moving mechanism drives the upper die to move upward, so that the piston moves upward together with the upper die. At the same time, the moving mechanism releases the extrusion on the compression molding mechanism, so that the compression molding mechanism drives the pushing mechanism to remove the piston sleeved on the compression molding mechanism from the compression molding mechanism.

[0006] As a further improvement of this technical solution, the compression molding mechanism includes a compression molding rod. A clamping groove ring and a conical block are fixed at the bottom of the compression molding rod. A spring is sleeved on the compression molding rod. A vertically arranged arc-shaped chute is opened at a position near the lower end inside the compression molding rod. The lower end of the arc-shaped chute penetrates through the clamping groove ring and communicates with the outside. A straight chute is opened on one side of the arc-shaped chute. The lower end of the straight chute penetrates through the lower side of the conical block. The lower end of the straight chute is arranged towards a position deviating from the center of the conical block. The middle positions of the straight chute and the arc-shaped chute are interconnected.

[0007] As a further improvement of this technical solution, the pushing mechanism includes an arc-shaped rod and a straight rod. The arc-shaped rod is slidably arranged inside the arc-shaped chute, and the straight rod is slidably arranged inside the straight chute. A number of teeth are fixed on the side walls of the arc-shaped rod and the straight rod that are close to each other. The teeth at the positions where the arc-shaped rod and the straight rod are close to each other are meshed with each other.

[0008] As a further improvement of this technical solution, a clamping groove ring block is fixed at the lower end of the arc-shaped rod. The clamping groove ring block is adapted to the notch at the position where the arc-shaped chute penetrates through the clamping groove ring. The shape of the bottom of the straight rod is adapted to the shape of the straight chute penetrating through the bottom of the conical block. When the straight rod does not extend out of the straight chute, a complete cone is formed between the bottom of the straight rod and the conical block, and a complete ring is formed between the clamping groove ring block and the clamping groove ring.

[0009] As a further improvement of this technical solution, the upper die includes two side modules and a number of middle modules arranged between the two side modules. The number of middle modules and the two side modules are fixedly connected by a number of screw rods. A number of compression molding mechanisms are respectively arranged between the side modules and the middle modules and between the number of middle modules.

[0010] As a further improvement of the technical solution, a plurality of spring grooves and rod chutes arranged below the spring grooves are formed on the side walls between the side module and the middle module and between several middle modules. The compression rod is slidably arranged inside the rod chute. The spring is arranged inside the spring groove. A top pressure plate is fixed to the top of the compression rod. The top pressure plate blocks the spring. Meanwhile, a top placement groove is formed above the spring groove. The top pressure plate is slidably arranged inside the top placement groove. The spring pushes the compression rod upward.

[0011] As a further improvement of the technical solution, an arc-shaped offset groove communicating with the rod chute is formed on one side of the rod chute. A cylindrical chute is formed at one end of the arc-shaped offset groove. One end of the arc-shaped rod extends out from the upper side of the arc chute and is slidably arranged in the arc-shaped offset groove. A connecting rod is fixed to one end of the arc-shaped rod arranged in the arc-shaped offset groove. The other end of the connecting rod is fixed with a cylindrical rod. The central axis of the cylindrical rod and the central axis of the arc center of the arc-shaped rod are on the same line. The cylindrical rod is slidably arranged inside the cylindrical chute. When the compression rod moves upward inside the rod chute, the compression rod drives the pushing mechanism to move upward. During the upward movement, the arc-shaped rod rotates towards the direction close to the compression rod under the guidance of the arc-shaped offset groove. The rotating arc-shaped rod drives the clamping groove ring block to push the inner side wall of the piston after compression molding. And the rotating arc-shaped rod drives the straight rod to move downward, so that the straight rod pushes the piston downward.

[0012] As a further improvement of the technical solution, the moving mechanism includes two side frames fixed to the upper side of the upper mold. A bottom connecting plate is fixed at the lower position between the two side frames. An extrusion cavity is formed between the bottom connecting plate and the upper mold. A pressure plate is arranged in the extrusion cavity. A compression hydraulic rod for pushing the pressure plate to move up and down in the extrusion cavity is installed at the middle position of the upper side wall of the bottom connecting plate. The moving pressure plate presses down on the top pressure plate. An upper connecting plate is fixed at the upper position between the two side frames. A lower pushing hydraulic rod is installed at the top of the mounting frame. The piston rod of the lower pushing hydraulic rod is fixed at the middle position of the upper side of the upper connecting plate.

[0013] As a further improvement of the technical solution, a moving groove is formed on the upper side of the workbench. An inclined discharge chute is formed on one side of the moving groove and slopes downward. A conveying mechanism is arranged on the lower side of the lower mold. The conveying mechanism includes a sliding plate slidably arranged inside the moving groove. The sliding plate is arranged on the lower side of the lower mold and is connected to the lower mold by screws. A plurality of horizontal sliding rods are slidably connected to the sliding plate. The horizontal sliding rods are fixed inside the moving groove. A horizontal pushing hydraulic rod is fixedly installed on the lower side of the sliding plate. One end of the piston rod of the horizontal pushing hydraulic rod is fixed on the side wall of the moving groove away from the mounting frame.

[0014] The second object of the present invention is to provide a compression molding method for a rubber piston using a rubber piston compression molding machine for a pre-filled syringe as described above, including the following method steps: S1. The conveying mechanism conveys the lower mold out of the mounting rack, then places the rubber block to be extruded on the lower mold. After the rubber block is placed, the conveying mechanism conveys the lower mold to the lower side of the mounting rack; S2. The moving mechanism drives the upper mold to move downward. When the upper mold presses on the rubber block on the lower mold, the moving mechanism pushes the compression molding mechanism to move downward, so that the conical block presses the rubber block. At this time, the feeding mechanism is received inside the compression molding mechanism; S3. After the piston compression molding is completed, the moving mechanism drives the upper mold to move upward. After the upper mold and the lower mold are separated, the conveying mechanism drives the lower mold away from the mounting rack, and the moving mechanism releases the extrusion on the compression molding mechanism. At this time, the compression molding mechanism drives the feeding mechanism to move upward, and the upward moving feeding mechanism pushes down the piston sleeved on the conical block. At the same time, the upward moving compression molding mechanism squeezes the piston by means of the bottom of the upper mold, so that the piston is separated from the conical block.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the rubber piston compression molding machine for a pre-filled syringe and its compression molding method, the moving mechanism drives the upper mold to approach the lower mold, so that the upper mold and the lower mold approach each other. At the same time, during the approach of the upper mold and the lower mold, the compression molding mechanism extends downward, so that the compression molding mechanism extrudes the rubber placed in the mold on the lower mold. By making the compression molding mechanism move downward slowly, the situation that the compression molding mechanism extrudes the rubber before the lower mold and the upper mold come into contact can be avoided, and the situation that the rubber overflows outside the mold can be reduced. In this way, the content of the rubber placed in the mold is reduced, and the amount of the rubber overflowing outside is reduced. After the piston compression molding is completed, the film formed outside the piston is also correspondingly reduced. In this way, the consumption of rubber in the process of manufacturing the piston is reduced, and thus the cost can be saved and the production output of the piston can be increased.

[0016] 2. In the rubber piston compression molding machine for prefilled syringes and its compression molding method, after the piston is compression molded by the compression molding die, the moving mechanism drives the upper die to move upward. After the upper die and the lower die are separated, the conveying mechanism drives the lower die away from the upper die, and the moving mechanism releases the downward pressure on the compression molding mechanism, causing the compression molding mechanism to move upward. During the upward movement of the compression molding mechanism, the compression molding mechanism drives the pushing mechanism to move. While moving upward following the compression molding mechanism, the moving pushing mechanism pushes the edge of the piston sleeved on the conical block outward and downward through the protrusion of the clamping groove ring block and the straight rod, and then drives the piston to squeeze the bottom of the upper die by the upward movement of the compression molding mechanism, causing the piston to fall off the compression molding mechanism. In this way, the trouble of manually removing the piston is eliminated. During the process of the pushing mechanism removing the piston, the worker only needs to place the raw material for compressing the piston on the lower die, thus accelerating the production speed of the piston and improving the automation degree of the piston manufacturing by the compression molding machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the workbench structure of the present invention; Figure 3 is a schematic diagram of the combined structure of the moving mechanism, compression molding die and conveying mechanism of the present invention; Figure 4 is a schematic diagram of the moving mechanism structure of the present invention; Figure 5 is a schematic diagram of the compression molding die structure of the present invention; Figure 6 is a schematic diagram of the lower die structure of the present invention; Figure 7 is a schematic diagram of the upper and lower side structures of the combined upper die and several compression molding mechanisms of the present invention; Figure 8 is a schematic diagram of the combined structure of the middle module and several compression molding mechanisms of the present invention; Figure 9 is a schematic diagram of the side module and middle module structure of the present invention; Figure 10 is a schematic diagram of the cylindrical sliding groove and arc-shaped offset groove structure of the present invention; Figure 11 is a schematic diagram of the combined structure of the compression molding mechanism and the pushing mechanism of the present invention; Figure 12 is a schematic diagram of the unfolded structure of the compression molding mechanism and the pushing mechanism of the present invention; Figure 13 is a partial structure schematic diagram of the compression molding mechanism of the present invention; Figure 14 is a schematic diagram of the structure of the pushing mechanism from two perspectives of the present invention; Figure 15 Structural schematic diagram of the compression molding mechanism and the pushing mechanism of the present invention when compression molding is completed; Figure 16 Structural schematic diagram of the compression molding mechanism and the pushing mechanism of the present invention when starting to push the piston; Figure 17 Structural schematic diagram of the compression molding mechanism and the pushing mechanism of the present invention when pushing the piston off; Figure 18 Structural schematic diagram of the compression molding mechanism and the pushing mechanism of the present invention after pushing the piston;

[0018] The meanings of each label in the figure are as follows: 1. Workbench; 11. Moving groove; 12. Horizontal sliding rod; 13. Discharge inclined port; 2. Mounting frame; 3. Moving mechanism; 31. Side frame; 32. Bottom connecting plate; 33. Upper connecting plate; 34. Pressing plate; 35. Compression molding hydraulic rod; 36. Lower pushing hydraulic rod; 37. Vertical sliding rod; 4. Compression molding die; 41. Side module; 42. Middle module; 43. Compression molding mechanism; 431. Main column rod; 432. Sub-column rod; 433. Spring; 434. Card slot ring; 435. Cone block; 436. Arc rod; 4361. Card slot ring block; 437. Connecting rod; 438. Cylindrical rod; 439. Top pressing plate; 44. Lower die; 45. Screw; 46. Spring groove; 461. Top placing groove; 47. Rod sliding groove; 48. Cylindrical sliding groove; 49. Arc offset groove; 5. Conveying mechanism; 51. Sliding plate; 52. Horizontal pushing hydraulic rod; 6. Straight sliding groove; 61. Straight rod; 62. Arc sliding groove. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0021] Example 1

[0022] See also Figures 1 - 18 As shown, one of the purposes of this embodiment is to provide a rubber piston compression molding machine for prefilled syringes, including a workbench 1, a mounting frame 2 is fixedly installed on the upper side of the workbench 1, the mounting frame 2 is a frame structure, the mounting frame 2 is fixed at one end of the upper side of the workbench 1, a compression mold 4 is arranged on the upper side of the workbench 1, the compression mold 4 includes an upper mold and a lower mold 44, the lower mold 44 is arranged on the upper side of the workbench 1, and a conveying mechanism 5 is arranged on the lower side of the lower mold 44, the conveying mechanism 5 drives the lower mold 44 to move closer to and away from the mounting frame 2 on the workbench 1, a moving groove 11 is opened on the upper side of the workbench 1, and a downwardly inclined discharge bevel 13 is opened on one side of the moving groove 11, the discharge bevel 13 runs through the side wall of the workbench 1, and the discharge bevel 13 is used to guide the piston falling from the compression mold 4, and the conveying mechanism 5 includes a sliding plate 51 slidably arranged inside the moving groove 11, and the sliding plate 51 is arranged on the lower side of the lower mold 44 and is connected to the lower mold 4 4 screws, so that the sliding plate 51 and the lower mold 44 are fixed together, and at the same time, a plurality of transverse sliding rods 12 are slidably connected to the sliding plate 51, and the transverse sliding rods 12 are fixed inside the moving groove 11. The plurality of transverse sliding rods 12 support the sliding plate 51, so that the sliding plate 51 can stably support the lower mold 44. At the same time, a transverse push hydraulic rod 52 is fixedly installed on the lower side of the sliding plate 51, and one end of the piston rod of the transverse push hydraulic rod 52 is fixed on the side wall of the moving groove 11 away from the mounting frame 2. When the piston rod of the transverse push hydraulic rod 52 is fully extended, the sliding plate 51 drives the lower mold 44 to the lower side of the mounting frame 2. When the piston rod of the transverse push hydraulic rod 52 is fully retracted, the sliding plate 51 drives the lower mold 44 away from the mounting frame 2. After the lower mold 44 is away from the mounting frame 2, the operator can place a rubber block for compression molding piston on the lower mold 44, wherein a plurality of piston mold grooves are provided on the lower mold 44, and the rubber block is placed in the piston mold grooves.

[0023] Inside the upper mold, several compression molding mechanisms 43 are provided, and a pushing mechanism is arranged on each compression molding mechanism 43. A moving mechanism 3 for driving the upper mold to move up and down is arranged on the upper side of the compression molding die 4. The moving mechanism 3 drives the upper mold to approach the lower mold 44. During the closing process of the upper mold and the lower mold 44, the moving mechanism 3 pushes the compression molding mechanism 43 downward. During the downward movement of the compression molding mechanism 43, the pushing mechanism is received into the interior of the compression molding mechanism 43. When the compression molding is completed, the moving mechanism 3 drives the upper mold to move upward, causing the piston to move upward together with the upper mold. At the same time, the moving mechanism 3 releases the extrusion on the compression molding mechanism 43, enabling the compression molding mechanism 43 to drive the pushing mechanism to remove the piston sleeved on the compression molding mechanism 43 from the compression molding mechanism 43, thereby completing the automatic removal of the piston, eliminating the trouble of manual piston removal, and improving the automation degree of the compression molding machine.

[0024] The structure of the compression molding mechanism 43 is refined as follows. Please refer to Figures 11 - 13 As shown, the compression molding mechanism 43 includes a compression molding rod. A clamping groove ring 434 and a cone block 435 are fixed to the bottom of the compression molding rod. A spring 433 is sleeved on the compression molding rod. A vertically arranged arc-shaped chute 62 is opened at a position near the lower end inside the compression molding rod. The radian angle of the arc-shaped chute 62 is less than 180 degrees. The lower end of the arc-shaped chute 62 penetrates through the clamping groove ring 434 and communicates with the outside. A straight chute 6 is opened on one side of the arc-shaped chute 62. The lower end of the straight chute 6 penetrates through the lower side of the cone block 435. The lower end of the straight chute 6 is arranged towards a position deviating from the center of the cone block 435. At the same time, the arc-shaped chute 62 and the straight chute 6 are arranged on the same side of the compression molding rod, and the arc-shaped chute 62 and the straight chute 6 are located on the axis of symmetry of the compression molding rod. The middle positions of the straight chute 6 and the arc-shaped chute 62 are interconnected. The compression molding rod is composed of a main column rod 431 and a secondary column rod 432, and the main column rod 431 and the secondary column rod 432 are fixedly connected by screws.

[0025] The main column rod 431 and the secondary column rod 432 have the same shape, and the clamping groove ring 434 and the cone block 435 are separately arranged on the main column rod 431 and the secondary column rod 432.

[0026] The pusher mechanism includes an arc-shaped rod 436 and a straight rod 61. The arc-shaped rod 436 is slidably arranged inside the arc-shaped chute 62, and the straight rod 61 is slidably arranged inside the straight chute 6. A number of teeth are fixed on the side walls of the arc-shaped rod 436 and the straight rod 61 that are close to each other. The teeth at the positions where the arc-shaped rod 436 and the straight rod 61 are close to each other are meshed with each other. At the same time, the connection line from the center of the arc-shaped rod 436 to the point closest to the straight rod 61 is perpendicular to the straight rod 61. At the same time, slide bars are fixed on both sides of the arc-shaped rod 436 and the straight rod 61. Slideways are formed on the side walls of the arc-shaped chute 62 and the straight chute 6. The slide bars are slidably arranged in the slideways. The mutual cooperation of the slide bars and the slideways is used to limit the sliding distance of the arc-shaped rod 436 and the straight rod 61. At the same time, a clamping groove ring block 4361 is fixed at the lower end of the arc-shaped rod 436. The clamping groove ring block 4361 is adapted to the notch at the position where the arc-shaped chute 62 penetrates the clamping groove ring 434. The shape of the bottom of the straight rod 61 is adapted to the shape of the bottom of the tapered block 435 where the straight chute 6 penetrates. That is, when the straight rod 61 and the arc-shaped rod 436 do not extend out of the straight chute 6, a complete ring is formed between the clamping groove ring block 4361 and the clamping groove ring 434, and a complete cone is formed between the bottom of the straight rod 61 and the tapered block 435. The shape formed by them is as shown in Figure 7 the shape shown by the compression molding mechanism 43 in

[0027] The upper mold includes two side modules 41 and several middle modules 42 arranged between the two side modules 41. The two side modules 41 and the several middle modules 42 are arranged side by side, and the several middle modules 42 and the two side modules 41 are fixedly connected by several screws 45. In this way, a shape with the same bottom area as the lower mold 44 is formed by combining the several middle modules 42 and the two side modules 41. At the same time, several compression molding mechanisms 43 are respectively arranged between the side module 41 and the middle module 42 and between the several middle modules 42, that is, on the side wall of the side module 41 close to the middle module 42, the side wall of the middle module 42 close to the side module 41, and the side wall of the middle module 42 close to another middle module 42. Compression molding mechanisms 43 are provided. At the same time, several spring grooves 46 and rod chutes 47 arranged on the lower side of the spring grooves 46 are opened on the side walls between the side module 41 and the middle module 42 and between the several middle modules 42. Among them, the corresponding spring grooves 46 and rod chutes 47 on the side module 41 and the middle module 42, and on the middle module 42 and the middle module 42 form a cylindrical space for arranging the compression rod and the spring 433. The compression rod is slidably arranged inside the rod chute 47, and the spring 433 is arranged inside the spring groove 46. At the same time, a top pressing plate 439 is fixed on the top of the compression rod. The radius of the top pressing plate 439 is larger than the radius size of the rod chute 47. The top pressing plate 439 blocks the spring 433, and the spring 433 pushes the compression rod upward to make the compression rod move upward. The upward movement distance of the top pressing plate 439 is the distance from the upper side of the clamping groove ring 434 after the compression rod compresses the block to the bottom of the side module 41. When the top of the top pressing plate 439 and the upper side wall of the side module 41 are on the same horizontal plane, the clamping groove ring 434 is in the position of the normal compression piston, and its position is as Figure 15 shown. At the same time, a top placing groove 461 is opened on the upper side of the spring groove 46, and the top pressing plate 439 is slidably arranged inside the top placing groove 461.

[0028] The moving mechanism 3 includes two side frames 31 fixed to the upper side of the upper mold. That is, the side module 41 and the middle module 42 are connected to the lower side of the side frame 31 by screws. A bottom connecting plate 32 is fixed at the lower position between the two side frames 31. An extrusion cavity is formed between the bottom connecting plate 32 and the upper mold. A pressing plate 34 is arranged in the extrusion cavity. The space for the pressing plate 34 to move up and down in the extrusion cavity is greater than the distance for the compression rod to move up and down. At the same time, a compression hydraulic rod 35 for pushing the pressing plate 34 to move up and down in the extrusion cavity is installed at the middle position of the upper side wall of the bottom connecting plate 32. The moving pressing plate 34 presses down on the top pressing plate 439. An upper connecting plate 33 is fixed at the upper position between the two side frames 31. The top of the mounting frame 2 is equipped with a lower pushing hydraulic rod 36. The piston rod of the lower pushing hydraulic rod 36 is fixed at the middle position of the upper side of the upper connecting plate 33. At the same time, a number of vertical sliding rods 37 are slidably connected to one side of the side frame 31. The two ends of the vertical sliding rods 37 are respectively fixed to the top of the mounting frame 2 and the top side wall of the workbench 1. The number of vertical sliding rods 37 restricts the stability of the side frame 31 moving up and down. When the piston rod of the lower pushing hydraulic rod 36 extends outwards, the lower pushing hydraulic rod 36 drives the upper mold to move downwards.

[0029] An arc-shaped offset groove 49 communicating with the rod chute 47 is opened on one side of the rod chute 47. A cylindrical chute 48 is opened at one end of the arc-shaped offset groove 49. One end of the arc-shaped rod 436 extends out from the upper side of the circular arc chute 62 and is slidably arranged in the arc-shaped offset groove 49. A connecting rod 437 is fixed at one end of the arc-shaped rod 436 arranged in the arc-shaped offset groove 49. The other end of the connecting rod 437 is fixed with a cylindrical rod 438. The central axis of the cylindrical rod 438 and the central axis of the arc-shaped rod 436 are on the same line. The cylindrical rod 438 is slidably arranged inside the cylindrical chute 48. When the compression rod moves upwards inside the rod chute 47, the compression rod drives the pushing mechanism to move upwards. During the upward movement of the arc-shaped rod 436, it rotates towards the direction close to the compression rod under the guidance of the arc-shaped offset groove 49. The rotating arc-shaped rod 436 drives the clamping groove ring block 4361 to push the inner side wall of the compressed piston, and the rotating arc-shaped rod 436 drives the straight rod 61 to move downwards, so that the straight rod 61 pushes the piston downwards. In this way, the piston is separated from the conical block 435, and its state is as Figure 16 shown. The upward moving compression rod pulls the piston upwards by means of the clamping groove ring 434. The pulled piston is blocked by the bottom of the upper mold. At this time, the edge of the piston is pushed outwards by the clamping groove ring block 4361, and its bottom is pushed downwards by the straight rod 61. Then, it contacts the extrusion of the upper mold and the clamping groove ring 434 on the upper opening position of the piston, so as to make the piston fall off from the conical block 435, and its structural state is as Figure 17 shown. After the piston leaves the conical block 435, the structure of the pushing mechanism is as Figure 18As shown, when the compression rod moves downward again, the compression rod drives the pushing mechanism, causing the protruding clamping groove ring block 4361 and the straight rod 61 in the pushing mechanism to retract into the interior of the compression rod, and its shape returns to the state shown by the compression mechanism 43 in Figure 7 In the middle.

[0030] Here, the upward and downward states of the arc rod 436 are refined. Please refer to Figure 10 , and the side of the arc offset groove 49 is marked in detail. Among them, the side of the arc offset groove 49 far from the rod chute 47 is successively d, a, and b from bottom to top, and the side of the arc offset groove 49 close to the rod chute 47 is successively c and e from bottom to top; When the top pressing plate 439 leaves the top placing groove 461 from inside the top placing groove 461, the state of the pushing mechanism is from Figures 15 - 17 The structural change. When the top pressing plate 439 is in the top placing groove 461, the state of the pushing mechanism is Figure 15 As shown. At this time, the side wall of the connecting rod 437 far from the straight rod 61 contacts d, and the outer side wall at the connection position of the connecting rod 437 and the arc rod 436 contacts the bending position where d and a are connected. When the compression rod drives the pushing mechanism to move upward, the cylindrical rod 438 moves upward in the cylindrical chute 48. During the upward movement of the connecting rod 437, the outer side wall at the connection position of the connecting rod 437 and the arc rod 436 slides in contact with a, and a guides one end of the connecting rod 437 to approach the rod chute 47. During the upward movement of the connecting rod 437, the arc rod 436 moves in the direction close to the rod chute 47. When the arc rod 436 moves, the arc rod 436 rotates around the axis of the cylindrical rod 438. The moving arc rod 436 slides in the arc chute 62, and the sliding arc rod 436 pushes the clamping groove ring block 4361 to protrude outward. During the sliding of the arc rod 436, the straight rod 61 makes one end of the straight rod 61 protrude from the cone block 435 by means of the tooth engagement between the straight rod 61 and the arc rod 436. During the protrusion of the clamping groove ring block 4361 and the straight rod 61, the state of the pushing mechanism is as Figure 16 As shown. When the clamping groove 434 contacts the lower side of the upper mold, the state of the pushing mechanism is as Figure 17 As shown. At this time, the side wall of the connecting rod 437 close to the arc rod 436 contacts c, the top of the arc rod 436 contacts b, and the outer side wall at the connection position of the connecting rod 437 and the arc rod 436 contacts the position where a and b are connected; When the top pressing plate 439 moves from away from the top placing groove 461 to entering the top placing groove 461, the state of the pushing mechanism is from Figures 17 - 15 The structural change. When the top pressing plate 439 is away from the top placing groove 461, the state of the pushing mechanism is Figure 17As shown, the side wall of the connecting rod 437 close to the arc-shaped rod 436 contacts c, the top of the arc-shaped rod 436 contacts b, and the outer side wall at the connecting position of the connecting rod 437 and the arc-shaped rod 436 contacts the position where a and b are connected. When the compression rod drives the feeding mechanism to move downward, c blocks the connecting rod 437, causing the side wall of the connecting rod 437 close to the arc-shaped rod 436 to move downward along c. During the downward movement of the connecting rod 437, since the cylindrical rod 438 is blocked by the cylindrical chute 48, the cylindrical rod 438 moves downward along the track of the cylindrical chute 48. During the downward movement of the cylindrical rod 438 along the cylindrical chute 48, the connecting rod 437 drives the arc-shaped rod 436 to rotate away from the rod chute 47, and the rotating arc-shaped rod 436 drives the straight rod 61 to move into the interior of the compression rod until the cylindrical rod 438 moves to the bottom of the cylindrical chute 48. At this time, the side wall of the connecting rod 437 contacts d, and the inner side wall of the arc-shaped rod 436 contacts e. At this time, the state of the feeding mechanism is Figure 15 the state shown.

[0031] When the device is in use, the operator places the rubber block in the piston die groove. After placement, the lower die 44 is conveyed to the lower side of the mounting frame 2 through the conveying mechanism 5. Then, the moving mechanism 3 drives the upper die to move downward. When the upper die presses on the rubber block on the lower die 44, the moving mechanism 3 pushes the compression mechanism 43 downward, causing the tapered block 435 to press the rubber block. At this time, the feeding mechanism is housed inside the compression mechanism 43. When the tapered block 435 contacts the rubber block, the compression rod is not fully extended. When the upper die and the lower die 44 are in close contact, the compression rod is fully extended. In this way, the amount of rubber extruded from the piston die groove by the compression rod is reduced, thereby reducing the waste of rubber. In this way, the content of rubber placed in the mold can be reduced, and the amount of rubber overflowing outward is reduced. After the piston is compressed, the film formed outside the piston is correspondingly reduced. In this way, the consumption of rubber during the production of the piston is reduced, thereby achieving the effect of cost savings and increased piston production.

[0032] After the compression molding is completed, the moving mechanism 3 drives the upper mold to move upward, separating the upper mold from the lower mold 44. After the upper mold and the lower mold 44 are separated, the conveying mechanism 5 drives the lower mold 44 away from the mounting frame 2. At this time, the operator can place a rubber block on the lower mold 44. After the upper mold and the lower mold 44 are separated, the compression molding hydraulic rod 35 drives the pressure plate 34 to move upward, releasing the extrusion of the pressure plate 34 on the top pressure plate 439. At this time, the compression molding rod drives the material pushing mechanism upward by the elastic force of the spring 433. The upward moving material pushing mechanism pushes down the piston sleeved on the conical block 435. At the same time, the upward moving compression molding mechanism 43 squeezes the piston by the bottom of the upper mold, causing the piston to disengage from the conical block 435. The disengaged piston falls into the discharge inclined port 13 through the moving groove 11, and the discharge inclined port 13 guides the piston away. During the process of the material pushing mechanism removing the piston, in order to ensure the dropping of the piston, the compression molding hydraulic rod 35 can drive the pressure plate 34 to move downward reciprocally three times, so as to ensure that the piston is pushed off the conical block 435 by the material pushing mechanism, thus eliminating the trouble of manually removing the piston. During the process of the material pushing mechanism removing the piston, the worker only needs to place the raw material for compressing the piston on the lower mold 44, which speeds up the production speed of the piston and improves the automation degree of the piston manufacturing by the compression molding machine.

[0033] The second object of the present invention is to provide a method for compressing a rubber piston by using the above-mentioned rubber piston compression molding machine for pre-filled syringes, including the following method steps: S1. The conveying mechanism 5 conveys the lower mold 44 out of the mounting frame 2, then places the rubber block to be extruded on the lower mold 44. After the rubber block is placed, the conveying mechanism 5 conveys the lower mold 44 to the lower side of the mounting frame 2. S2. The moving mechanism 3 drives the upper mold to move downward. When the upper mold squeezes the rubber block on the lower mold 44, the moving mechanism 3 pushes the compression molding mechanism 43 downward, causing the conical block 435 to squeeze the rubber block. At this time, the material pushing mechanism is received inside the compression molding mechanism 43. S3. After the piston compression molding is completed, the moving mechanism 3 drives the upper mold to move upward. After the upper mold and the lower mold 44 are separated, the conveying mechanism 5 drives the lower mold 44 away from the mounting frame 2. The moving mechanism 3 releases the extrusion of the compression molding mechanism 43. At this time, the compression molding mechanism 43 drives the material pushing mechanism to move upward. The upward moving material pushing mechanism pushes down the piston sleeved on the conical block 435. At the same time, the upward moving compression molding mechanism 43 squeezes the piston by the bottom of the upper mold, causing the piston to disengage from the conical block 435.

[0034] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification are only preferred examples of the present invention, and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A rubber piston molding machine for prefilled syringes, comprising a workbench (1), a mounting frame (2) being fixedly mounted on the upper side of the workbench (1), characterized in that: A compression mold (4) is arranged on the upper side of the workbench (1), and the compression mold (4) comprises an upper mold and a lower mold (44). A plurality of compression molding mechanisms (43) are arranged inside the upper mold, and each compression molding mechanism (43) is provided with a material pushing mechanism. A moving mechanism (3) for driving the upper mold to move up and down is arranged on the upper side of the compression mold (4). The lower mold (44) is arranged on the upper side of the workbench (1). The moving mechanism (3) drives the upper mold to approach the lower mold (44) and pushes the upper mold to move upward and downward. During the closing process of the upper mold and the lower mold (44), the moving mechanism (3) pushes the compression molding mechanism (43) to move downward, and during the downward movement of the compression molding mechanism (43), the pushing mechanism is received inside the compression molding mechanism (43); after the compression molding is completed, the moving mechanism (3) drives the upper mold to move upward, so that the piston moves upward along with the upper mold, and at the same time, the moving mechanism (3) releases the squeezing of the compression molding mechanism (43), so that the compression molding mechanism (43) drives the pushing mechanism to remove the piston sleeved on the compression molding mechanism (43) from the compression molding mechanism (43); The compression molding mechanism (43) comprises a compression molding rod, a vertically arranged circular arc groove (62) is provided at a position near the lower end of the compression molding rod, the lower end of the circular arc groove (62) passes through the clamping groove ring (434) and is connected to the outside, a straight groove (6) is provided on one side of the circular arc groove (62), the lower end of the straight groove (6) passes through the lower side of the cone block (435), the lower end of the straight groove (6) is arranged toward a position deviating from the center of the cone block (435), and the middle positions of the straight groove (6) and the circular arc groove (62) are connected to each other; The push mechanism comprises an arc rod (436) and a straight rod (61), wherein the arc rod (436) is slidably arranged inside the circular arc slide groove (62), and the straight rod (61) is slidably arranged inside the straight slide groove (6), and a plurality of teeth are fixed to the side walls of the arc rod (436) and the straight rod (61) close to each other, and the teeth of the arc rod (436) and the straight rod (61) at the positions close to each other mesh with each other.

2. The rubber piston molding machine for prefilled syringes according to claim 1, characterized in that: A clamping ring (434) and a cone block (435) are fixed to the bottom of the compression-molding rod, and a spring (433) is sleeved on the compression-molding rod.

3. The rubber piston molding machine for prefilled syringes according to claim 1, characterized in that: A groove ring block (4361) is fixed to the lower end of the arc rod (436); the groove ring block (4361) and the notch at the position where the arc slide groove (62) passes through the groove ring (434) are matched; the shape of the bottom of the straight rod (61) and the shape of the bottom of the straight slide groove (6) passing through the cone block (435) are matched; when the straight rod (61) does not extend out of the straight slide groove (6), a complete cone is formed between the bottom of the straight rod (61) and the cone block (435), and a complete ring is formed between the groove ring block (4361) and the groove ring (434).

4. The rubber piston compression molding machine for prefilled syringes according to claim 2, characterized in that: The upper mold comprises two side modules (41) and a plurality of middle modules (42) arranged between the two side modules (41); the plurality of middle modules (42) and the two side modules (41) are fixedly connected via a plurality of screws (45); and a plurality of compression molding mechanisms (43) are respectively arranged between the side modules (41) and the middle modules (42) and between the plurality of middle modules (42).

5. The rubber piston molding machine for prefilled syringes according to claim 4, characterized in that: A plurality of spring slots (46) and a rod slide slot (47) arranged below the spring slot (46) are provided on the side walls between the side modules (41) and the middle modules (42) and between the plurality of middle modules (42); the compression molded rod is slidably arranged inside the rod slide slot (47); the spring (433) is arranged inside the spring slot (46); a top pressure plate (439) is fixed on the top of the compression molded rod; the top pressure plate (439) blocks the spring (433); and a top release slot (461) is provided on the upper side of the spring slot (46); the top pressure plate (439) is slidably arranged inside the top release slot (461); and the spring (433) pushes the compression molded rod upward.

6. The rubber piston molding machine for prefilled syringes according to claim 5, characterized in that: An arc-shaped offset groove (49) connected to the rod slide groove (47) is provided on one side of the rod slide groove (47); a cylindrical slide groove (48) is provided on one end of the arc-shaped offset groove (49); one end of the arc-shaped rod (436) extends from the upper side of the arc-shaped slide groove (62) and is slidably arranged in the arc-shaped offset groove (49); a connecting rod (437) is fixed to one end of the arc-shaped rod (436) arranged in the arc-shaped offset groove (49); a cylindrical rod (438) is fixed to the other end of the connecting rod (437); a central axis of the cylindrical rod (438) is aligned with the arc-shaped rod (436); 36) The center axes of the circles are on the same line, and the cylindrical rod (438) is slidably arranged inside the cylindrical slide groove (48). When the compression molding rod moves upward inside the rod slide groove (47), the compression molding rod drives the pushing mechanism to move upward, and the arc rod (436) rotates toward the compression molding rod under the guidance of the arc offset groove (49) during the upward movement. The rotating arc rod (436) drives the groove ring block (4361) to push the inner side wall of the piston after compression molding, and the rotating arc rod (436) drives the straight rod (61) to move downward, so that the straight rod (61) pushes the piston downward.

7. The rubber piston molding machine for prefilled syringes according to claim 1, characterized in that: The moving mechanism (3) comprises two side frames (31) fixed on the upper side of the upper mold, a bottom connecting plate (32) is fixed at a position located at the lower side between the two side frames (31), an extrusion cavity is formed between the bottom connecting plate (32) and the upper mold, a pressing plate (34) is arranged in the extrusion cavity, a compression hydraulic rod (35) is installed at the middle position of the upper side wall of the bottom connecting plate (32) to push the pressing plate (34) to move up and down in the extrusion cavity, the moving pressing plate (34) presses down the top pressing plate (439), an upper connecting plate (33) is fixed at a position located at the upper side between the two side frames (31), a push-down hydraulic rod (36) is installed at the top of the mounting frame (2), and the piston rod of the push-down hydraulic rod (36) is fixed at the middle position of the upper side of the upper connecting plate (33).

8. The rubber piston molding machine for prefilled syringes according to claim 1, characterized in that: A movable groove (11) is provided on the upper side of the workbench (1), and a downwardly inclined discharge bevel (13) is provided on one side of the movable groove (11). A conveying mechanism (5) is provided on the lower side of the lower mold (44), and the conveying mechanism (5) comprises a sliding plate (51) slidably arranged inside the movable groove (11), the sliding plate (51) is arranged on the lower side of the lower mold (44) and is screwed to the lower mold (44), and a plurality of transverse sliding rods (12) are slidably connected to the sliding plate (51), and the transverse sliding rods (12) are fixed inside the movable groove (11). A transverse push hydraulic rod (52) is fixedly installed on the lower side of the sliding plate (51), and one end of the piston rod of the transverse push hydraulic rod (52) is fixed on the side wall of the movable groove (11) away from the mounting frame (2).

9. A method for operating a rubber piston compression molding machine for a prefilled syringe according to any one of claims 1 to 8 to perform compression molding on a rubber piston, characterized in that: The method comprises the following steps: S1, the conveying mechanism (5) conveys the lower mold (44) out of the mounting frame (2), and then places the extruded rubber block on the lower mold (44). After the rubber block is placed, the conveying mechanism (5) conveys the lower mold (44) to the lower side of the mounting frame (2); S2, the moving mechanism (3) drives the upper mold to move downward, and when the upper mold squeezes the rubber block on the lower mold (44), the moving mechanism (3) pushes the compression molding mechanism (43) to move downward, so that the cone block (435) squeezes the rubber block, and at this time, the pushing mechanism is stored inside the compression molding mechanism (43); S3. After the piston has completed compression molding, the moving mechanism (3) drives the upper mold to move upward. After the upper mold and the lower mold (44) are separated, the conveying mechanism (5) drives the lower mold (44) away from the mounting frame (2). The moving mechanism (3) releases the compression molding mechanism (43). At this time, the compression molding mechanism (43) drives the pushing mechanism to move upward. The upward pushing mechanism pushes down the piston sleeved on the cone block (435). At the same time, the upward compression molding mechanism (43) squeezes the piston with the help of the bottom of the upper mold, so that the piston is separated from the cone block (435).

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