Pre-plasticizing device

Abstract

The utility model belongs to the technical field of injection molding, and particularly relates to a pre-molding device which comprises a base, a conveying shell is fixed to the top of the base, a motor is fixed to one side of the top of the base, a conveying channel is formed in the inner side of the conveying shell, and a feeding screw is installed in the conveying channel through a bearing. An extrusion cavity channel is formed in the lower portion of the interior of the conveying shell and is parallel to the conveying channel, electric heating pieces are evenly arranged in the extrusion cavity channel and the conveying channel, a hydraulic cylinder is fixed to the end, close to the motor, of the upper surface of the base, and a push head is slidably installed in the extrusion cavity channel; the motor and the spiral conveying rod are controlled through the coupler, molten raw materials can be conveyed into the extrusion cavity through rotation of the spiral rod in the pre-plasticizing stage, and when the raw materials in the extrusion cavity reach a threshold value, the coupler can be separated through an internal mechanism, the spiral conveying rod stops rotating, and damage to a machine body caused by internal pressure increase is prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of injection molding, and particularly relates to a pre-molding device. Background Art

[0002] Preplasticization is a process used in injection molding to improve the efficiency and quality of thermoplastic molding. Plasticization and injection are performed separately in two barrels or zones. This ensures uniform heating of the thermoplastic resin, consistent injection pressure, and reduced internal pressure in the part, facilitating the production of thin-walled products. Preplasticization also utilizes the cooling time after molding to increase the equipment's plasticizing capacity, shorten cycle times, and improve production capacity. This technology is widely used in injection molding equipment.

[0003] During the pre-molding stage, existing injection molding machines use a hydraulic unit to control the push rod and the opening and closing of the mold to move synchronously. However, when pushing the material, the spiral conveying rod inside continues to rotate, which may cause internal pressure to increase and cause damage to the machine body. If the spiral conveying rod is stopped during each push injection, the motor controlling the spiral conveying rod needs to be stopped and started reciprocatingly during multiple injection molding processes, which will affect the service life of the motor. Utility Model Content

[0004] In response to the problems existing in the prior art, the purpose of the present utility model is to provide a pre-molding device, which can disconnect the screw conveying rod from the motor during the injection molding process so that the screw rod no longer rotates, thereby preventing damage caused by excessive pressure inside the machine body.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A pre-plasticizing device comprises a base, a conveying shell is fixed on the top of the base, a motor is fixed on one side of the top of the base, a conveying channel is opened inside the conveying shell, a feeding screw is installed inside the conveying channel through a bearing, an extrusion cavity is opened at the lower part of the conveying shell, the extrusion cavity is parallel to the conveying channel, electric heating plates are evenly arranged inside the extrusion cavity and the conveying channel, a hydraulic cylinder is fixed on one end of the upper surface of the base close to the motor, a push head is slidably installed inside the extrusion cavity, a push rod is provided at the output end of the hydraulic cylinder, the end of the push rod away from the hydraulic cylinder is fixed to the end of the push head, a coupling A is provided at the output end of the motor, an extension shaft is provided on the side of the feeding screw close to the motor, the extension shaft passes through the rear end surface of the conveying shell, an I-shaped shaft sleeve is slidably installed on the end surface of the extension shaft away from the feeding screw, and a coupling B is provided at the end of the I-shaped shaft sleeve, and the coupling B corresponds to the coupling A.

[0007] Furthermore, a mounting plate is symmetrically provided below one end of the conveying shell close to the motor, a rotating shaft is installed between the two mounting plates through a bearing, a U-shaped fork rod is provided on the top of the rotating shaft, and the U-shaped fork rod is clamped on the I-shaped shaft sleeve.

[0008] Furthermore, a toggle rod is provided on the lower surface of the rotating shaft.

[0009] Furthermore, a fixed block is provided at one end of the push rod close to the hydraulic cylinder, a movable block is fixed to the surface of the push rod by bolts, and the bottom of the toggle rod is placed between the fixed block and the movable block.

[0010] Furthermore, a communication hole is formed at one end of the delivery channel and the extrusion cavity away from the motor, and a one-way valve is provided inside the communication hole.

[0011] Furthermore, an injection head is installed at the end of the extrusion cavity, and a control valve is provided inside the injection head.

[0012] Furthermore, a hopper is provided above one end of the conveying shell close to the motor.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the motor and the screw conveying rod are controlled by a coupling, and the rotation of the screw rod in the pre-plasticization stage can convey the molten raw material into the extrusion chamber. When the raw material inside the extrusion chamber reaches a threshold value, the coupling can be separated by the internal mechanism, and the screw conveying rod stops rotating to prevent the increase in internal pressure from causing damage to the machine body. Conversely, after the push injection is in place, the coupling can be overlapped and matched to allow the screw rod to rotate for the next pre-plasticization work, thereby realizing linkage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of the utility model;

[0015] Figure 2 This is a schematic diagram of the longitudinal front cross-sectional structure of the utility model;

[0016] Figure 3 For the utility model Figure 2 Schematic diagram of the enlarged structure of area A;

[0017] Figure 4 For the utility model Figure 2 Schematic diagram of the enlarged structure of area B.

[0018] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0019] 1. Base; 2. Motor; 3. Conveying shell; 4. Conveying channel; 5. Feeding screw; 6. Electric heating plate; 7. Extrusion cavity; 8. Injection head; 9. Connecting hole; 10. One-way valve; 11. Control valve; 12. Hydraulic cylinder; 13. Push rod; 14. Push head; 15. Coupling A; 16. Extension shaft; 17. I-shaped shaft sleeve; 18. Coupling B; 19. Mounting plate; 20. Rotating shaft; 21. U-shaped shift fork rod; 22. Toggle rod; 23. Fixed block; 24. Movable block; 25. Hopper. DETAILED DESCRIPTION

[0020] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0021] Please refer to Figure 1-Figure 4 As shown, a pre-plasticizing device includes a base 1, a conveying shell 3 is fixed on the top of the base 1, a motor 2 is fixed on one side of the top of the base 1, a conveying channel 4 is opened inside the conveying shell 3, a feeding screw 5 is installed inside the conveying channel 4 through a bearing, and the internal raw material is conveyed by the rotation of the feeding screw 5, an extrusion cavity 7 is opened at the lower part of the conveying shell 3, the extrusion cavity 7 is parallel to the conveying channel 4, and electric heating plates 6 are evenly arranged inside the extrusion cavity 7 and the conveying channel 4 to heat and melt the internal raw material so that the plastic raw material is fluid. A hydraulic cylinder 12 is fixed on one end of the upper surface of the base 1 close to the motor 2, a push head 14 is slidably installed inside the extrusion cavity 7, and a push rod 13 is provided at the output end of the hydraulic cylinder 12. The hydraulic cylinder 12 only needs to control the push rod 13 Move forward to realize the injection work, the end of the push rod 13 away from the hydraulic cylinder 12 is fixed to the end of the push head 14, the output end of the motor 2 is provided with a coupling A15, and the side of the feed screw 5 close to the motor 2 is provided with an extension shaft 16, the extension shaft 16 passes through the rear end surface of the conveying shell 3, and the end surface of the extension shaft 16 away from the feed screw 5 is slidably installed with an I-shaped shaft sleeve 17, and the end of the I-shaped shaft sleeve 17 is provided with a coupling B18, and the surface of the extension shaft 16 is provided with a convex strip, and the inside of the I-shaped shaft sleeve 17 is provided with a groove corresponding to the convex strip, so that the I-shaped shaft sleeve 17 can slide on the axis and drive the extension shaft 16 to rotate together. The coupling B18 corresponds to the coupling A15, and the coupling B18 cooperates with the coupling A15 to control the rotation of the feed screw 5 through the motor 2.

[0022] Please refer to Figure 2 and Figure 3As shown, a mounting plate 19 is symmetrically provided below one end of the conveying shell 3 close to the motor 2, and a rotating shaft 20 is installed between the two mounting plates 19 through a bearing. A U-shaped fork rod 21 is provided on the top of the rotating shaft 20, and the U-shaped fork rod 21 is clamped on the I-shaped shaft sleeve 17. The rotation of the rotating shaft 20 is used to drive the I-shaped shaft sleeve 17 to slide axially, thereby controlling whether the coupling B18 and the coupling A15 are matched.

[0023] Among them, a toggle rod 22 is provided on the lower surface of the rotating shaft 20, and a fixed block 23 is provided at the end of the push rod 13 close to the hydraulic cylinder 12. A movable block 24 is fixed to the surface of the push rod 13 by bolts. The movable block 24 can adjust its position according to actual usage to control the space threshold inside the extrusion cavity 7. When a large volume product is required to be injected with more raw materials in a single time, the distance between the movable block 24 and the fixed block 23 can be adjusted to increase, and the bottom of the toggle rod 22 is placed between the fixed block 23 and the movable block 24.

[0024] Please refer to Figure 2 and Figure 4 As shown, a connecting hole 9 is opened at the end of the conveying channel 4 and the extrusion cavity 7 away from the motor 2, and a one-way valve 10 is arranged inside the connecting hole 9. The one-way valve 10 can ensure that the raw material fluid can only flow into the extrusion cavity 7 and cannot flow in the opposite direction.

[0025] Among them, an injection head 8 is installed at the end of the extrusion cavity 7, and a control valve 11 is provided inside the injection head 8. The control valve 11 is controlled by a computer and is only opened when injecting and pushing materials, and is in a closed state at other times.

[0026] Please refer to Figure 1 As shown, a hopper 25 is provided above one end of the conveying shell 3 close to the motor 2 for temporarily storing the plastic granule raw materials.

[0027] The working principle of the present invention is as follows: the plastic raw material is placed inside the hopper 25, the hopper 25 is connected to the inside of the conveying channel 4, the motor 2 is started, the feeding screw 5 can be driven to rotate, and the plastic particles are heated and melted by the extrusion of the electric heating plate 6, so that the raw material forms a fluid, and the rotation of the feeding screw 5 will squeeze the fluid into the extrusion cavity 7 through the connecting hole 9, so that the pressure at the end of the extrusion cavity 7 increases. At this time, the control valve 11 is kept closed. When the pressure inside the extrusion cavity 7 increases, the push head 14 can be pushed back, and then the push rod 13 can be driven to move back. When the internal capacity of the extrusion cavity 7 reaches the prefabrication, the bottom of the toggle rod 22 can be moved back by moving the movable block 24 backward. It swings backward, and the rotating shaft 20 rotates clockwise, and then through the cooperation of the U-shaped fork rod 21 and the I-shaped shaft sleeve 17, the coupling B18 moves forward and disengages from the coupling A15. At this time, the coupling A15 is idling, and the feed screw 5 stops rotating. After the mold is closed, the hydraulic cylinder 12 drives the push rod 13 to move forward, and at the same time, the control valve 11 is opened to squeeze out the solution inside the extrusion cavity 7 through the push head 14 and inject it into the mold through the injection head 8. When the push head 14 reaches the front end, the fixed block 23 can drive the toggle rod 22 to rotate counterclockwise, and the coupling B18 and the coupling A15 are re-engaged, and the feed screw 5 rotates to carry out the next injection.

[0028] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention shall, unless otherwise specified or limited, be implemented in accordance with conventional means in the art.

Claims

1. A pre-molding device, comprising a base (1), Features: A conveying shell (3) is fixed on the top of the base (1), a motor (2) is fixed on one side of the top of the base (1), a conveying channel (4) is provided on the inner side of the conveying shell (3), a feeding screw (5) is installed inside the conveying channel (4) through a bearing, an extrusion cavity (7) is provided at the lower part of the conveying shell (3), the extrusion cavity (7) is parallel to the conveying channel (4), electric heating plates (6) are evenly arranged inside the extrusion cavity (7) and the conveying channel (4), a hydraulic cylinder (12) is fixed on one end of the upper surface of the base (1) close to the motor (2), and a push head (12) is slidably installed inside the extrusion cavity (7). 4), a push rod (13) is provided at the output end of the hydraulic cylinder (12), and the end of the push rod (13) facing away from the hydraulic cylinder (12) is fixed to the end of the push head (14), and a coupling A (15) is provided at the output end of the motor (2), and an extension shaft (16) is provided on the side of the feeding screw (5) close to the motor (2), and the extension shaft (16) passes through the rear end surface of the conveying shell (3), and an I-shaped shaft sleeve (17) is slidably installed on the end surface of the extension shaft (16) facing away from the feeding screw (5), and a coupling B (18) is provided at the end of the I-shaped shaft sleeve (17), and the coupling B (18) corresponds to the coupling A (15).

2. A pre-plasticizing device according to claim 1, Features: A mounting plate (19) is symmetrically arranged below one end of the conveying shell (3) close to the motor (2); a rotating shaft (20) is installed between the two mounting plates (19) via a bearing; a U-shaped shift fork rod (21) is arranged on the top of the rotating shaft (20); and the U-shaped shift fork rod (21) is clamped on the I-shaped shaft sleeve (17).

3. A pre-plasticizing device according to claim 2, Features: A toggle rod (22) is provided on the lower surface of the rotating shaft (20).

4. A pre-plasticizing device according to claim 3, Features: A fixed block (23) is arranged at one end of the push rod (13) close to the hydraulic cylinder (12); a movable block (24) is fixed to the surface of the push rod (13) by bolts; and the bottom of the toggle rod (22) is placed between the fixed block (23) and the movable block (24).

5. A pre-plasticizing device according to claim 4, Features: A connecting hole (9) is provided at one end of the conveying channel (4) and the extrusion cavity (7) away from the motor (2), and a one-way valve (10) is provided inside the connecting hole (9).

6. A pre-plasticizing device according to claim 5, Features: An injection head (8) is installed at the end of the extrusion cavity (7), and a control valve (11) is arranged inside the injection head (8).

7. A pre-plasticizing device according to claim 1, Features: A hopper (25) is provided above one end of the conveying shell (3) close to the motor (2).

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