CN202079740U - Conical screw injection machine - Google Patents

Abstract

The utility model conical screw injection machine mainly includes plasticizing parts, injection parts, mold clamping parts and a base, and consists of a feeding device, a screw, a machine barrel, a motor, a transmission device, a storage and injection system, a heating device, a mold and a mold clamping system. and so on. The plasticizing screw is a conical screw, and the number of the screws can be single screw, double screw or triple screw. Plasticization-injection separation structure is adopted: the material enters the storage tank after being plasticized by the screw, and the piston in the storage tank advances relative to the storage cylinder to reduce the volume for injection, and the melt in the storage tank is injected out of the nozzle and enters the mold. The cavity is molded. After the injection is finished, the piston in the storage cylinder retreats relative to the storage cylinder to increase the volume for storage. Before the metering section, only plasticization and mixing are completed, and the change in the volume of the storage tank only realizes storage and injection, and the screw rotation mechanism does not move back and forth relative to the material cylinder. The injection capacity does not depend on the ratio of the screw diameter to the plasticizing stroke, but only on the volume of the storage tank.

Description

Conical screw injection machine

technical field

The utility model conical screw injection machine can be used for the injection process in the processing of plastics, rubber, paint, paper pulp, medicine, feed, food, explosives and the like. The machine can be used for both experiments and direct production. the

Background technique

The working principle of the reciprocating screw injection machine is that the material is heated and plasticized in the barrel, and the material is further plasticized and transported to the end of the screw by the rotation of the screw in the barrel. When a certain amount is reached, the screw moves forward quickly to inject the material stored at the front end into the mold. Due to its simple structure and other characteristics, it has been widely used. the

In fact, the storage section of the traditional reciprocating screw injection machine is the continuation of the metering section, but the screw does not extend to this section, and the injection must be moved forward after the screw is rotated and plasticized. During injection, the mechanism related to screw rotation must move forward relative to the barrel. This causes the following limitations: (1) In order to ensure the injection pressure, the injection driving force must be very large; (2) The amount of material stored each time must be small, resulting in a small injection volume; (3) High-pressure injection and high-pressure injection are easily formed in the small barrel. Shearing causes the material to decompose; (4) Plasticization and injection must be carried out in sequence, and they are mutually restricted, resulting in a small range of injection volume, materials and molds applicable to the injection machine. (5) The traditional straight screw plasticization is not effective for polyvinyl chloride and other materials. Therefore, it is necessary to solve these problems. the

The utility model separates the storage section from the previous metering section. The volume change in the storage section is entirely for the purpose of injection, and the part before the metering section does not need to take into account this function but only completes plasticization and mixing. Secondly, the piston connected to the nozzle in the storage section moves to change the volume of the storage section, and there is no need to move the screw relative to the barrel to rotate the relevant mechanism. In this way, the separation of plasticizing and injection functions is realized, continuous plasticizing can be carried out, and the production rate is obviously improved; the injection capacity of this new type of injection machine is not limited by the ratio of screw diameter to plasticizing stroke like ordinary injection molding machines, only with storage It is related to the volume of the material cylinder. Smaller diameter screw can be used for plasticizing to obtain large injection capacity, and it can also injection mold super-large and miniature products. Since it is not limited by the requirements of injection movement, it is also possible to choose a large screw to increase the injection volume conveniently. the

Different from the ordinary cylindrical screw used in the traditional injection machine, the utility model adopts the high-efficiency plasticizing system of the conical screw on the basis of the plasticizing-injection separation structure, which obviously improves the plasticizing quality of the material. Conical screw extrusion has been successfully applied to difficult-to-process materials such as heat-sensitive materials such as polyvinyl chloride and high-fill composite materials. Moreover, the diameter of the tapered screw tail is increased, which improves the bearing capacity of the screw; the volume of the screw groove in the feeding section is large, the feeding amount is large, and it is easy to add a large volume of bulk powder; it is also conducive to heat conduction, and it is easier to realize heating or heating of the material. Cooling; the diameter of the screw in the discharge section is small, the peripheral speed is small, the shear generated is low, the frictional heat is small, and the risk of thermal damage is small; the volume of the screw groove gradually decreases along the extrusion direction, and the material is gradually compressed. So that the screw groove can be filled with material faster, ensuring continuous and gentle plasticization of the material. It can be seen that the combination of conical screw plasticizing system and plasticizing-injection separation process can solve many problems of traditional injection machines, expand its application range, and has the characteristics of high efficiency and energy saving. the

In the screw plasticizing system, single-screw, twin-screw, triple-screw or even multi-screw systems can be used. For example, in a twin-screw extruder, the convex rows of two screws are staggered and opposed to each other to form a "C-shaped" chamber. The material is sheared, rubbed, heated, and kneaded to enhance the mixing and plasticizing effect; The forward conveying capacity of the material is large, and the output is high; the two screws mesh with each other, the self-cleaning effect is good, and the decomposition and carbonization of the material is reduced, so it is widely used in the extruder. In the same way, multi-screw can further increase production. In this way, applying twin-screw, triple-screw or even multi-screw plasticizing systems to the plasticizing-injection separation process of the utility model will greatly improve the plasticizing efficiency and quality of materials, and has unique advantages for forming large-scale injection-molded products. the

Utility model content

The utility model conical screw injection machine is mainly composed of a feeding device, a screw, a machine barrel, a motor, a transmission device, a material storage and injection system, a heating device, a mold and a mold clamping mechanism and the like. In the utility model, the injection machine adopts a plasticizing-injection separation structure, the screw rod is a conical screw rod, and the number of the screw rods can be single screw rod, double screw rod or triple screw rod. the

In the utility model, the plasticizing-injecting separation structure separates the storage section from the previous metering section. A non-reverse device is installed at the head of the plasticizing screw to ensure that the material flows from the plasticizing barrel to the storage section with little or no backflow. The internal volume of the storage section is changed by controlling the movement of the piston connected with the nozzle relative to the storage cylinder, and the screw rotating mechanism is not required to move back and forth relative to the storage cylinder. The volume change in the storage section only realizes injection, and the part before the metering section only completes plasticization and mixing. the

When the new injection machine is working, the material enters the storage tank after being plasticized by the screw, and the piston in the storage tank advances relative to the storage tank to reduce the volume for injection, and the melt in the storage tank is injected out of the nozzle and enters the mold cavity. After the injection is finished, the piston in the storage cylinder retreats relative to the storage cylinder to increase the volume for storage. The injection capacity of this new type of injection molding machine is not limited by the ratio of screw diameter to plasticizing stroke like ordinary injection molding machines, but is only related to the volume of the storage tank. Realize the separation of plasticizing and injection functions, and can carry out continuous plasticizing, which can significantly increase the production rate; it can use small diameter screw to plasticize to prepare large-capacity or even super-large-capacity injection products. the

Different from the ordinary straight cylindrical screw in the conventional injection machine, the screw in the utility model adopts a conical screw to ensure the continuous and gentle plasticization of the material, and can process heat-sensitive materials; increase the bearing capacity of the screw; the volume of the screw groove in the feeding section is large , easy to add larger bulk density powder. the

The number of screws in the injection machine can be single screw, twin screw or triple screw. When twin-screw or triple-screw is used, the arrangement of the screws and the direction of rotation can be combined in various ways, which need to be selected according to different materials and process requirements to obtain the best products with the minimum energy consumption. the

The effect of the utility model: the screw rod of the injection machine in the utility model is a conical screw rod, which is especially suitable for injection processing of difficult-to-process materials such as powder materials and heat-sensitive materials. The injection machine adopts a plasticizing-injection separation structure, which significantly increases the output and expands the scope of application of the injection machine. The screw can be twin-screw or triple-screw, which enhances the mixing effect of materials in plasticization and increases the output at the same time. the

Description of drawings

Figure 1 Structural schematic diagram of the utility model conical screw injection machine

Figure 2 Schematic diagram of the structure of the utility model conical screw injection machine when twin screws are used

Figure 3 is a schematic diagram of the screw arrangement when the conical three-screw is arranged in a straight line.

Figure 4 Schematic diagram of screw arrangement when conical three-screws are arranged in a triangle

specific implementation plan

Implementation plan one:

As shown in Fig. 1, the conical screw injection machine of the utility model mainly includes plasticizing parts, injection parts, mold clamping parts and bases, etc. The plasticizing part includes: a motor 1, a transmission device 2, a feeding device 3, a heating device 4, a barrel 5, a non-return device 6, a screw 10, and a screw head 12. The injection part includes a storage cylinder 13, a piston 7, a nozzle 8, a flow channel 14, a frame rod 11 and a hydraulic cylinder 15, etc. The piston 7 and the nozzle 8 are connected together to form a flow channel 14 inside. Mold 16 can be installed between the templates of clamping device 9, and drives the moving mold half of mould. the

Working principle: the mold 16 is closed under the drive of the clamping device 9 . The material is fed from the feeding port 3, and the screw 10 is driven by the motor 1 to rotate the plasticized material. Under the action of back pressure, the material enters the storage tank 13 through the non-return device 6 . The machine base pull rod 11 drives the machine base as a whole (the screw rotation system (1, 2, 10), material barrel and material storage cylinder are fixed on the machine base) to retreat and expand the volume to fully store materials. Adjust the nozzle to be in contact with the gate of the mold. Under the action of the hydraulic cylinder 15, the machine base rod 11 drives the machine base to move forward rapidly. The material passes through the flow channel 14 and enters the mold 16 through the nozzle 8. After cooling under pressure, the mold is opened and the product is ejected. So far, an injection process has been completed. During injection, the screw can rotate continuously for plasticization, or it can be paused to wait for injection to complete replasticization. After the injection was completed, the machine base pull rod 11 drives the machine base as a whole to retreat and then store materials. Repeatedly, the entire injection molding is formed. the

Implementation plan two:

The plasticizing process can adopt various screw forms such as conical twin-screws, in-line arrangement of conical three-screws and triangular arrangement of conical three-screws shown in Figure 2, Figure 3 and Figure 4, to increase production and expand the scope of application of the equipment. the

Implementation plan three:

The principle is similar to that of Embodiment 1, but the difference is that the screw rotation system (1, 2, 10) and the barrel are placed on the base of the injection machine without moving back and forth, and the pull rod is fixed on the base of the injection machine or the fixed template of the fixed mold clamping system. The hydraulic cylinder 15 drives the piston 7 and the nozzle 8 to move back and forth. Reduce the storage volume and increase the material pressure to inject, and increase the storage volume to make more materials flow from the plasticizing barrel to the storage tank. the

Implementation plan four:

The principle is similar to that of Embodiment 3, except that the pull rod is fixed on the movable platen of the mold clamping system, and the hydraulic cylinder 15 drives the piston 7 and the nozzle 8 to move back and forth through the pull rod. The mold closing movable platen moves forward to drive the piston to reduce the storage volume for injection, and the movable platen moves backward during mold opening to drive the piston to move and expand the storage volume for storage. the

Implementation plan five:

In conventional injection molding, materials enter the mold cavity through nozzles, runners and gates. When molding large-scale products, the nozzle can be omitted, and the material in the storage tank can be injected into the mold cavity through the tubular runner and gate connected to the inner hole of the piston. the

Claims (3)

1. conical screw injector, mainly comprise plasticizing parts, injection member and matched moulds parts and base, form by feeding device, screw rod, machine barrel, motor, transmission device, bin stock and injecting systems, heater, mould and matched moulds system etc., it is characterized in that: adopt conical screw plasticizing system and plasticizing-injection separate type.

2. conical screw injector according to claim 1 is characterized in that: plasticizing can be single screw rod, twin-screw or three screw rod various ways with conical screw.

3. conical screw injector according to claim 1, it is characterized in that: material enters material storage jar in the plasticizing-injection separate type behind spiro rod plasticizing, the relative bin stock cylinder body of material storage jar inner carrier advances and dwindles volume and inject, melt injection delivery nozzle in the material storage jar is entered die cavity carry out moulding, injection finishes, and the relative bin stock cylinder body of material storage jar inner carrier retreats and increases volume and carry out bin stock; Only finish plasticizing and mixing before the metering section, the variation of material storage jar internal volume only realizes bin stock and injection, and the relative barrel of rotary screw does not move forward and backward; Injection capacity does not depend on screw diameter and the ratio that plastifies stroke, and is only relevant with the material storage jar volume.

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