Single-cylinder injection and pre-molding device

Abstract

The utility model discloses a single-cylinder injection and pre-plasticization device which comprises an injection module, a pre-plasticization module and a control module, the injection module is connected with an external injection mold, and molten plastic is injected into the injection mold by the injection module; the heating module is arranged outside the injection module in a sleeving mode to form a heating area, and the heating area is used for melting plastic in the injection module; and the power module is connected with the injection module and drives the injection module to move. When the single-cylinder injection and pre-plasticization device is used for injection and pre-plasticization, the motion resistance is smaller, the response is quick, and meanwhile, the service life of the screw rod is longer.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic injection molding, in particular to a single-cylinder injection and pre-molding device. Background Art

[0002] The double cylinder injection and pre-plasticization device, the two injection cylinders and the screw are combined side by side, so that the movement axis of the two injection cylinders and the movement axis of the screw during injection are not on the same axis. Since the movement of the two injection cylinders during injection cannot be guaranteed to be absolutely synchronized, the screw is affected by the eccentric force during injection, which will shorten the service life of the screw and the sensitivity of the screw movement during injection is not high. At the same time, the two injection cylinders have two sets of sealing elements to seal the pistons and piston rods of the injection cylinders, so that the resistance of the two injection cylinders is large when they move. When the screw rotates for pre-plasticization, the pressure of the molten plastic at the front end of the screw moves the screw. The screw and the two injection cylinders are fixedly connected to the two injection cylinder pistons. When the screw rotates for pre-plasticization, the screw moves together with the pistons of the two injection cylinders, causing the pressure of the molten plastic at the front end of the screw to increase when the screw rotates for pre-plasticization. The displayed back pressure value and the actual back pressure value are quite different, which may cause the actual back pressure value to affect the temperature increase of the molten plastic. Summary of the invention

[0003] According to an embodiment of the utility model, a single-cylinder injection and pre-molding device is provided, comprising:

[0004] An injection module, which is connected to an external injection mold and injects molten plastic into the injection mold;

[0005] A heating module is sleeved on the outside of the injection module to form a heating zone for melting the plastic in the injection module;

[0006] The power module is connected to the injection module, and the power module drives the injection module to move.

[0007] Further, the injection module comprises:

[0008] Nozzle: The nozzle is used to flow out the molten plastic;

[0009] The barrel is connected to the nozzle, and the plastic is melted in the barrel;

[0010] Screw: The screw is arranged in the barrel, and the screw conveys the plastic to be melted to the heating zone for heating and melting;

[0011] A mixing element, which is arranged in the barrel and is used to mix the molten plastic;

[0012] Check ring, which is used to prevent the molten plastic from flowing back during injection;

[0013] The check ring and the mixing element are movably arranged in sequence at one end of the screw molten plastic outlet.

[0014] Furthermore, the screw is a screw with a single or double thread combination.

[0015] Furthermore, the injection module also includes: a feed port, which is connected to the other end of the screw, and the plastic to be melted reaches the screw through the feed port for transportation.

[0016] Furthermore, the heating module comprises: a first heating ring and a second heating ring; the first heating ring is sleeved on the nozzle for heating the nozzle; the second heating ring is sleeved on the barrel for heating and melting the plastic in the barrel.

[0017] Furthermore, the power module comprises:

[0018] An injection piston, one end of which is connected to the other end of the screw, and the injection piston drives the screw to move;

[0019] A rotating shaft, one end of which is slidably connected to the other end of the injection piston;

[0020] The power element is connected to the other end of the rotating shaft, and the power element drives the rotating shaft to rotate.

[0021] Furthermore, the power element is an oil motor or an electric motor.

[0022] Furthermore, the power module also includes:

[0023] Injection seat;

[0024] An injection cylinder, which is arranged inside the injection seat;

[0025] A first injection cylinder sleeve, which is disposed at one end of the injection cylinder barrel, and an injection piston passes through the first injection cylinder sleeve and moves in the injection cylinder barrel;

[0026] The second injection cylinder sleeve is arranged at the other end of the injection cylinder barrel, and the rotating shaft passes through the second injection cylinder sleeve and is connected with the injection piston.

[0027] Furthermore, the injection cylinder is provided with a first oil port and a second oil port. When the other end of the injection piston moves in the injection cylinder, the injection cylinder forms two chambers, and the first oil port and the second oil port are connected to the two chambers respectively.

[0028] According to the single-cylinder injection and pre-molding device of the embodiment of the utility model, during injection and pre-molding, the movement resistance is smaller, the response is quick, and the service life of the screw is longer.

[0029] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a single-cylinder injection and pre-plasticizing device according to an embodiment of the utility model. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings to further illustrate the present invention.

[0032] First, combine Figure 1 A single-cylinder injection and pre-molding device according to an embodiment of the utility model is described, which is used for plastic injection molding and has a wide range of application scenarios.

[0033] like Figure 1 As shown, the single-cylinder injection and pre-molding device of the embodiment of the utility model comprises an injection module 1, a heating module 2 and a power module 3.

[0034] Specifically, Figure 1 As shown, the injection module 1 is connected with the external injection mold, and the injection module 1 injects the molten plastic into the injection mold; the heating module 2 is sleeved on the outside of the injection module 1 to form a heating zone for melting the plastic in the injection module 1; the power module 3 is connected with the injection module 1, and the power module 3 drives the injection module 1 to move. Compared with the double-cylinder injection, the structure is simple and the manufacturing cost is low.

[0035] Further, if Figure 1 As shown, the injection module 1 includes: a nozzle 11, a barrel 12, a screw 13, a mixing element 14 and a check ring 15; the nozzle 11 is used to flow out the molten plastic; the barrel 12 is connected to the nozzle 11 through a connecting piece 16, and the plastic is melted in the barrel 12; the screw 13 is arranged in the barrel 12, and the screw 13 transports the plastic to be melted to the heating zone for heating and melting; the mixing element 14 is arranged in the barrel 12, and is used to mix the molten plastic; the check ring 15 is used to prevent the molten plastic from flowing back when the screw 13 is injected; the check ring 15 and the mixing element 14 are movably arranged in sequence at one end of the molten plastic outlet of the screw 13.

[0036] Furthermore, the screw 13 is a screw with a single or double thread combination 13. The screw with a single or double thread combination 13 in this embodiment can melt the plastic raw material better and improve the quality of the product.

[0037] Further, if Figure 1 As shown, the injection module 1 further comprises: a feed port 17, which is connected to the other end of the screw 13. The plastic to be melted reaches the screw 13 through the feed port 17 and is then transported by the screw 13. While being transported, the heating module 2 heats and melts the plastic.

[0038] Further, if Figure 1As shown, the heating module 2 includes: a first heating coil 21 and a second heating coil 22; the first heating coil 21 is sleeved on the nozzle 11 for heating the nozzle 11; the second heating coil 22 is sleeved on the barrel 12 for heating and melting the plastic in the barrel 12.

[0039] Further, if Figure 1 As shown, the power module 3 includes: an injection piston 31, a rotating shaft 32 and a power element 33; one end of the injection piston 31 is connected to the other end of the screw 13 through a transmission sleeve 18, and the injection piston 31 drives the screw 13 to move; one end of the rotating shaft 32 is slidably connected to the other end of the injection piston 31; the power element 33 is connected to the other end of the rotating shaft 32, and the power element 33 drives the rotating shaft 32 to rotate.

[0040] The injection piston 31 and the screw 13 in this embodiment are on the same axis. Compared with the two injection pistons 31 of the double-cylinder injection, the single-cylinder injection has smaller friction resistance, faster response and more sensitive action switching during injection and pre-molding.

[0041] Furthermore, the power element 33 is an oil motor or an electric motor.

[0042] Further, if Figure 1 As shown, the power module 3 also includes: an injection seat 34, an injection cylinder 35, a first injection cylinder sleeve 36 and a second injection cylinder sleeve 37; the injection cylinder 35 is arranged inside the injection seat 34; the first injection cylinder sleeve 36 is arranged at one end of the injection cylinder 35, and the injection piston 31 passes through the first injection cylinder sleeve 36 and moves in the injection cylinder 35; the second injection cylinder sleeve 37 is arranged at the other end of the injection cylinder 35, and the rotating shaft 32 passes through the second injection cylinder sleeve 37 and is connected to the injection piston 31.

[0043] Further, if Figure 1 As shown, the injection cylinder 35 is provided with a first oil port 351 and a second oil port 352. When the other end of the injection piston 31 moves in the injection cylinder 35, the injection cylinder 35 forms two chambers, and the first oil port 351 and the second oil port 352 are connected to the two chambers respectively.

[0044] In this embodiment, when the screw 13 rotates for pre-molding, since there is only one injection piston 31, only one set of sealing elements (not shown in the figure) is needed for sealing. The resistance of one set of sealing elements is smaller, so that the molten pressure at the front end of the screw 13 during the rotation of the screw 13 for pre-molding is reduced, the back pressure control is easier, the difference between the displayed back pressure value and the actual back pressure value is reduced, it is not easy to cause the temperature of the molten plastic to rise, and the quality of the molten plastic is effectively improved.

[0045] During injection, the hydraulic oil provided by the external hydraulic pump enters one of the chambers in the injection cylinder 35 through the external hydraulic valve from the second oil port 352 at a set pressure and flow rate. The chamber is the injection chamber. When the hydraulic oil enters the chamber, it will push the injection piston 31 to move forward at a set force and speed, and at the same time drive the screw 13 to move together. The check ring 15 at the front end of the screw 13 retreats under the action of the molten plastic pressure to seal the screw groove of the screw 13 to prevent the molten plastic at the front end of the screw 13 from flowing back during the injection of the screw 13. At this time, the molten plastic enters the injection mold through the nozzle 11 to form a finished product or semi-finished product.

[0046] After injection and pressure holding are completed, the screw 13 retreats a certain distance at a set force and speed to release the molten plastic pressure caused by the pressure holding at the front end of the screw 13. The hydraulic oil provided by the external hydraulic pump enters another chamber in the injection cylinder 35 through the first oil port 351 through the external hydraulic valve at a set pressure and flow rate. The chamber is a retreat chamber. When the hydraulic oil enters the chamber, it will push the injection piston 31 to retreat at a set force and speed, and at the same time make the screw 13 retreat together.

[0047] During pre-molding, after the screw 13 has completed injection molding, pressure holding, and retreat, there is very little molten plastic at the front end of the screw 13, which cannot meet the requirements of re-injection and pressure holding. The molten plastic at the front end of the screw 13 needs to be supplemented. At this time, the hydraulic oil directly driven by the external motor or provided by the external hydraulic pump enters the oil motor through the external hydraulic valve at the set pressure and flow rate to drive the oil motor to rotate. The rotation of the motor or the oil motor will drive the rotating shaft 32, the injection piston 31 and the screw 13 to rotate together. The unmelted granular plastic at the discharge port 17 will be transported forward along the screw groove of the rotating screw 13, and will be compressed, sheared, and mixed by the screw groove of the screw 13, and will be heated externally by the first heating coil 21 and the second heating coil 22. The unmelted granular plastic will gradually melt and mix as the screw 13 rotates. When it finally reaches the output end of the screw 13, it has been completely melted and can be injected again.

[0048] Above, refer to Figure 1 The invention describes a single-cylinder injection and pre-molding device according to an embodiment of the utility model. During injection and pre-molding, the movement resistance is smaller, the response is faster, and the service life of the screw is longer.

[0049] It should be noted that, in this specification, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0050] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A single cylinder injection and pre-plasticization device, characterized in that: Include: An injection module, the injection module is connected to an external injection mold, and the injection module injects molten plastic into the injection mold; A heating module, which is sleeved on the outside of the injection module to form a heating zone for melting the plastic in the injection module; A power module is connected to the injection module, and the power module drives the injection module to move.

2. The single-cylinder injection and pre-plasticizing device according to claim 1, characterized in that: The injection module comprises: A nozzle, the nozzle is used to discharge the molten plastic; A barrel, the barrel is connected to the nozzle, and the plastic is melted in the barrel; A screw, the screw being arranged in the barrel, and the screw conveying the plastic to be melted to the heating zone for heating and melting; A mixing element, which is disposed in the barrel and is used to mix the molten plastic; A check ring, the check ring is used to prevent the molten plastic from flowing back; The check ring and the mixing element are movably arranged in sequence at one end of the screw.

3. The single-cylinder injection and pre-molding device according to claim 2, characterized in that: The screw is a screw with single and double threads.

4. The single cylinder injection and pre-molding device according to claim 2 or 3, characterized in that: The injection module further comprises: a feed port, the feed port is connected with the other end of the screw, and the plastic to be melted reaches the screw through the feed port for transportation.

5. The single-cylinder injection and pre-molding device according to claim 3, characterized in that: The heating module comprises: a first heating ring and a second heating ring; the first heating ring is sleeved on the nozzle for heating the nozzle; the second heating ring is sleeved on the barrel for heating and melting the plastic in the barrel.

6. The single-cylinder injection and pre-molding device according to claim 3, characterized in that: The power module comprises: An injection piston, one end of which is connected to the other end of the screw, and the injection piston drives the screw to move; A rotating shaft, one end of which is connected to the other end of the injection piston; A power element is connected to the other end of the rotating shaft, and the power element drives the rotating shaft to rotate.

7. The single cylinder injection and pre-plasticization device according to claim 6, characterized in that: The power element is an oil motor or an electric motor.

8. The single cylinder injection and pre-molding device according to claim 6, characterized in that: The power module also includes: Injection seat; An injection cylinder, the injection cylinder being arranged inside the injection seat; a first injection cylinder sleeve, the first injection cylinder sleeve being arranged at one end of the injection cylinder barrel, the injection piston passing through the first injection cylinder sleeve and moving in the injection cylinder barrel; A second injection cylinder sleeve, wherein the second injection cylinder sleeve is arranged at the other end of the injection cylinder barrel, and the rotating shaft passes through the second injection cylinder sleeve and is connected to the injection piston.

9. The single-cylinder injection and pre-molding device according to claim 8, characterized in that: The injection cylinder is provided with a first oil port and a second oil port. When the other end of the injection piston moves in the injection cylinder, the injection cylinder forms two chambers. The first oil port and the second oil port are connected to the two chambers respectively.

Images