Plastic injection molding machine with an injection unit disposed at the center of a toggle clamp mechanism

Abstract

A plastic injection molding machine with an injection component arranged at the center of the toggle clamp mechanism. It adopts an outward-turning toggle clamp mechanism, which creates a central space to accommodate the injection component, enabling the parallel arrangement of the clamp mechanism and the injection component. This significantly reduces the overall length of the machine, which is approximately 50% of that of machines of the same specification, and the overall mass is about 70% of that of machines of the same specification. It uses less material, has a low cost, and more machines can be arranged per unit area. Small machines can easily enter the freight elevator and be transported to multiple floors for use, which is conducive to the intensive use of land. The injection component is directly fixed at the center of the clamp mechanism away from the frame, and the central position of the nozzle is not affected by the deformation of the frame, ensuring good nozzle position retention. By removing the screws of the injection cylinder base and the barrel fixing plate, as well as the relevant oil pipes and wires, the injection component can be taken out as a whole, making it extremely convenient to replace the barrel, screw, and for maintenance and repair. The mold is installed at the side end of the machine. After the product is demolded, it falls from the side along the product hopper, which neither interferes with the operation nor is convenient for collection and transportation by the conveyor belt.

Description

Technical Field

[0001] The present invention relates to a plastic injection molding machine, and more particularly to a plastic injection molding machine with an injection component disposed at the center of a toggle clamping mechanism group. Background Art

[0002] In existing horizontal plastic injection molding machines, the structural layout is centered around the mold. On one side, a toggle clamping mechanism is arranged, and on the other side, an injection component is arranged. The clamping mechanism and the injection component are fixed on a frame-shaped machine frame welded by section steel. The disclosed technologies include: the patent with the patent number ZL.2007.2.0150759.3 applied by our company in 2007, the patent with the application number 02236521.4 applied by Hongyang Machinery Co., Ltd. in Taiwan, China in 2020, the patent with the application number 98204223.X applied by Huaqin Machinery Factory Co., Ltd. in 1998, the United States Patent with the patent number 5,252,286, and the United States Patent Publication No.: US2002 / 0068109A1. The above technologies belong to the same structure, and the piston rod of the moving mold cylinder is fixed to the moving template. The large tie rods and the working plates connected to both ends of the large tie rods have no relative movement with the machine frame during operation. To meet the usage requirements, the ejection cylinder must be fixed at the center of the moving template. Therefore, it is impossible to arrange the injection component at the center of the toggle clamping mechanism group in the above structures. The clamping mechanism and the injection component must be arranged in series on the left and right, resulting in a long length, a large floor area, poor rigidity, easy deviation of the nozzle center, difficulty in replacing the barrel and the screw. Also, since the mold is in the middle of the whole machine, the products just fall at the operation station, which is not only inconvenient for operation but also difficult to directly transport by a conveyor belt. Moreover, it uses a lot of materials and has a high cost. Summary of the Invention

[0003] The object of the present invention is to make up for the above deficiencies and disclose to the society a new type of plastic injection molding machine with a short overall machine length, a small floor area, strong rigidity, good maintainability of the nozzle center position, convenient replacement of the barrel and screw, convenient collection and transportation of products by a conveyor belt, low cost, and convenient operation. The mold clamping toggle lever turns outwards to make room in the middle to accommodate the injection component. The injection component is arranged at the center of the mold clamping toggle lever group, and the mold clamping mechanism and the injection component are arranged in parallel. The technical solution adopted by the present invention to solve the above technical problems is: a plastic injection molding machine with an injection component arranged at the center of the mold clamping toggle lever group. The large tie rods are sequentially sleeved with a moving platen, a fixed platen, a coupling sleeve, a barrel fixing plate, a moving mold push plate frame, and a toggle lever hinge plate. The fixed platen and the barrel fixing plate are respectively fixed to the coupling sleeve with screws. The fixed platen, the coupling sleeve, the barrel fixing plate, and the moving mold push plate frame are in clearance fit with the large tie rods. Nuts are screwed into both ends of the large tie rods. One end is pressed tightly into the moving platen by a screw passing through a pressure plate, and the other end is pressed tightly into the toggle lever hinge plate by a screw passing through a pressure plate. Four hinge holes are symmetrically arranged on the toggle lever hinge plate according to the cross center line. Four groups of short shaft rods are hinged to the toggle lever hinge plate. The other ends of the short shaft rods are respectively hinged to long toggle levers. The other ends of the long toggle levers are hinged to the barrel fixing plate. The middle parts of the four groups of short shaft rods are respectively hinged to two-force rods. The other ends of the two-force rods are hinged to the moving mold push plate frame. Guide rail sliders are respectively fixed to the downward-facing surfaces of the moving platen and the toggle lever hinge plate. The guide rail sliders are matched with linear guide rails to restrict the other five degrees of freedom of the guide rail sliders except the axial direction along the linear guide rails. The linear guide rails are fixed to the machine frame. The groove fixing seat is fixed to the machine frame. The barrel fixing plate is embedded in the groove of the groove fixing seat. The injection cylinder seat is fixed to the middle of the barrel fixing plate with screws. The barrel is fixed in the middle of the injection cylinder seat. The other end of the injection cylinder seat is fixed to the injection cylinder. The piston rod of the injection cylinder is fixed to the injection rod that can move relative to the inside of the barrel. The injection cylinder can drive the injection rod to move. For the plastic injection molding machine with the injection component arranged at the center of the mold clamping toggle lever group, moving mold cylinders are respectively fixed on both sides of the moving mold push plate frame. The piston rods of the moving mold cylinders are fixed to the toggle lever hinge plate. When the piston rods of the moving mold cylinders extend, the distance between the moving mold push plate frame and the toggle lever hinge plate increases. The short shaft rods and the long toggle levers tend to straighten. The toggle lever hinge plate, the large tie rods, and the moving platen move simultaneously. The distance between the moving platen and the fixed platen decreases, and a mold clamping force is formed under the action of the two-force rods. When the piston rods of the moving mold cylinders retract, the distance between the moving mold push plate frame and the toggle lever hinge plate decreases. The two-force rods pull the short shaft rods, and the short shaft rods and the long toggle levers turn outwards. The moving platen moves away from the fixed platen to complete the mold opening action. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic front view of a horizontal perspective cross-section Figure 2 is Figure 1 a partial cross-sectional top view schematic diagram with the machine frame, the injection component, and one large tie rod blocking the moving mold cylinder removed. Figure 3 is Figure 1 a schematic left view of an A-A cross-section. Figure 4 is Figure 1Schematic cross-sectional view of the injection part. The names of the reference numerals in the accompanying drawings of the specific implementation manner are: pressure plate 1, nut 2, moving plate 3, large tie rod 4, fixed plate 5, coupling sleeve 6, barrel 7, injection rod 8, barrel fixing plate 9, long toggle lever 10, injection cylinder seat 11, mold moving push plate frame 12, two-force rod 13, short shaft rod 14, toggle lever hinge plate 15, injection cylinder 16, guide rail slider 17, linear guide rail 18, frame 19, groove fixing seat 20, product blanking hopper 21, mold moving cylinder 22. A plastic injection molding machine with an injection part arranged at the center of the mold clamping toggle lever group. The large tie rod 4 is successively sleeved with the moving plate 3, fixed plate 5, coupling sleeve 6, barrel fixing plate 9, mold moving push plate frame 12, and toggle lever hinge plate 15. The fixed plate 5 and the barrel fixing plate 9 are respectively fixed to the coupling sleeve 6 with screws. The fixed plate 5, coupling sleeve 6, barrel fixing plate 9, and mold moving push plate frame 12 are in clearance fit with the large tie rod 4. Nuts 2 are screwed into both ends of the large tie rod 4. One end is pressed by a screw passing through the pressure plate 1 and screwed into the moving plate 3, and the other end is pressed by a screw passing through the pressure plate 1 and screwed into the toggle lever hinge plate 15. Four hinge holes are symmetrically arranged on the toggle lever hinge plate 15 according to the cross center line. Four groups of short shaft rods 14 are hinged to the toggle lever hinge plate 15. The other ends of the short shaft rods 14 are respectively hinged to the long toggle levers 10. The other ends of the long toggle levers 10 are hinged to the barrel fixing plate 9. The middle parts of the four groups of short shaft rods 14 are respectively hinged to the two-force rods 13. The other ends of the two-force rods 13 are hinged to the mold moving push plate frame 12. Guide rail sliders 17 are respectively fixed to the downward-facing surfaces of the moving plate 3 and the toggle lever hinge plate 15. The guide rail sliders 17 cooperate with the linear guide rail 18 to restrict the other five degrees of freedom of the guide rail sliders 17 except the axial direction along the linear guide rail 18. The linear guide rail 18 is fixed to the frame 19. The groove fixing seat 20 is fixed to the frame 19. The barrel fixing plate 9 is embedded in the groove of the groove fixing seat 20. The injection cylinder seat 11 is fixed to the middle of the barrel fixing plate 9 with screws. The barrel 7 is fixed in the middle of the injection cylinder seat 11. The other end of the injection cylinder seat 11 is fixed to the injection cylinder 16. The piston rod of the injection cylinder 16 is fixed to the injection rod 8 that can move relative to the inside of the barrel 7 in the barrel 7. The piston rod of the injection cylinder 16 can drive the injection rod 8 to move. For the plastic injection molding machine with the injection part arranged at the center of the mold clamping toggle lever group, mold moving cylinders 22 are respectively fixed to both sides of the mold moving push plate frame 12. The piston rods of the mold moving cylinders 22 are fixed to the toggle lever hinge plate 15. When the piston rods of the mold moving cylinders 22 extend, the distance between the mold moving push plate frame 12 and the toggle lever hinge plate 15 increases. The short shaft rods 14 and the long toggle levers 10 tend to straighten. The toggle lever hinge plate 15, large tie rod 4, and moving plate 3 move simultaneously. The distance between the moving plate and the fixed plate 5 decreases. A mold clamping force is formed under the action of the two-force rod 13. When the piston rods of the mold moving cylinders 22 retract, the distance between the mold moving push plate frame 12 and the toggle lever hinge plate 15 decreases. The two-force rod 13 pulls the short shaft rod 14. The short shaft rods 14 and the long toggle levers 10 turn outwards. The moving plate 3 moves away from the fixed plate 5 to complete the mold opening action.Working steps of a plastic injection molding machine with the above injection component arranged at the center of the toggle clamp group: First step: The piston rod of the moving mold cylinder 22 extends, the distance between the moving mold push plate frame 12 and the toggle joint plate 15 increases, the short shaft rod 14 and the long toggle 10 tend to straighten, the toggle joint plate 15, the large tie rod 4, and the moving platen 3 move simultaneously, the distance between the moving platen and the fixed platen 5 decreases, and a clamping force is formed under the action of the two-force rod 13. Second step: The piston rod of the injection cylinder 16 pushes the injection rod 8 to complete the injection action. Third step: The injection rod 8 retracts into the cylinder of the injection cylinder 16 to complete the feeding. Fourth step: The piston rod of the moving mold cylinder 22 retracts, the distance between the moving mold push plate frame 12 and the toggle joint plate 15 decreases, the short shaft rod 14 and the long toggle 10 turn outwards under the pulling of the two-force rod 13, and the moving platen 3 moves away from the fixed platen 5 to complete the mold opening action. Fifth step: Under the action of the ejection mechanism, the product in the mold is ejected to complete a production cycle. Advantages: The present invention adopts an outwards-turning toggle clamping mechanism to vacate the central space to accommodate the injection component, so that the clamping mechanism and the injection component are arranged in parallel, greatly reducing the overall length of the machine, about 50% of that of the same-specification machine, and the overall mass of the machine is about 70% of that of the same-specification machine. It uses less materials and has a low cost, and more machines can be arranged per unit area. Small machines can conveniently enter the freight elevator and be transported to multiple floors for use, which is conducive to intensive use of land. Since the injection component is directly fixed at the center of the clamping mechanism away from the frame, the central position of the nozzle is not affected by the deformation of the frame, so the nozzle position has good maintainability. The injection component can be taken out as a whole by removing the fixing screws of the injection cylinder seat and the barrel fixing plate and the relevant oil pipes and electric wires, and it is extremely convenient to replace the barrel, the screw and for maintenance and repair. The mold is arranged at the side end of the machine. After the product is ejected from the mold, it falls from the side along the product falling hopper 21, which does not interfere with the operation and is convenient for collection and transportation by the conveyor belt.

Claims

1. A plastic injection molding machine with an injection component disposed at the center of a toggle clamp group, characterized in that: The large tie rods (4) are sequentially sleeved with a moving platen (3), a stationary platen (5), a coupling sleeve (6), a barrel fixing plate (9), a mold moving push plate frame (12), and a toggle link hinge plate (15). The stationary platen (5) and the barrel fixing plate (9) are respectively fixed to the coupling sleeve (6) with screws. There is a clearance fit between the stationary platen (5), the coupling sleeve (6), the barrel fixing plate (9), the mold moving push plate frame (12) and the large tie rods (4). Nuts (2) are screwed into both ends of the large tie rods (4). One end is pressed tightly by a screw passing through a pressure plate (1) and screwed into the moving platen (3), and the other end is pressed tightly by a screw passing through the pressure plate (1) and screwed into the toggle link hinge plate (15). Four hinge holes are symmetrically arranged on the toggle link hinge plate (15) according to the cross center line. Four groups of short shaft rods (14) are hinged to the toggle link hinge plate (15). The other ends of the short shaft rods (14) are respectively hinged to long toggle links (10). The other ends of the long toggle links (10) are hinged to the barrel fixing plate (9). Two-force rods (13) are respectively hinged to some of the four groups of short shaft rods (14). The other ends of the two-force rods (13) are hinged to the mold moving push plate frame (12). Guide rail sliders (17) are respectively fixed to the downward-facing surfaces of the moving platen (3) and the toggle link hinge plate (15). The guide rail sliders (17) cooperate with linear guide rails (18) to restrict the other five degrees of freedom of the guide rail sliders (17) except for the axial direction along the linear guide rails (18). The linear guide rails (18) are fixed to the machine frame (19). The groove fixing seat (20) is fixed to the machine frame (19). The barrel fixing plate (9) is embedded in the groove of the groove fixing seat (20). The injection cylinder seat (11) is fixed to the middle of the barrel fixing plate (9) with screws. The barrel (7) is fixed in the middle of the injection cylinder seat (11). The other end of the injection cylinder seat (11) is fixed to an injection cylinder (16). The piston rod of the injection cylinder (16) is fixed to an injection rod (8) that can move relative to the inside of the barrel (7) within the barrel (7). The injection cylinder (16) can drive the injection rod (8) to move; Mold moving cylinders (22) are respectively fixed to both sides of the mold moving push plate frame (12). The piston rods of the mold moving cylinders (22) are fixed to the toggle link hinge plate (15). When the piston rods of the mold moving cylinders (22) extend, the distance between the mold moving push plate frame (12) and the toggle link hinge plate (15) increases. The short shaft rods (14) and the long toggle links (10) tend to straighten. The toggle link hinge plate (15), the large tie rods (4), and the moving platen (3) move simultaneously, and the distance between the moving platen and the stationary platen (5) decreases. A clamping force is formed under the action of the two-force rods (13). When the piston rods of the mold moving cylinders (22) retract, the distance between the mold moving push plate frame (12) and the toggle link hinge plate (15) decreases. The two-force rods (13) pull the short shaft rods (14), and the short shaft rods (14) and the long toggle links (10) turn outwards. The moving platen (3) moves in the direction away from the stationary platen (5) to complete the mold opening action.

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