CN105751455B - Spiral shell disk and plunger combination formula Coinjection molding apparatus - Google Patents

Abstract

The invention relates to a combined screw disk and plunger injection molding device, which includes an injection cylinder, an injection seat, a motor, a transmission mechanism, a seat, a centripetal thrust bearing, a hopper, a barrel, an electric heater, a mobile cylinder, gears and Plunger; the feature is that it also includes a plasticizing screw, which includes a turntable and a cylinder. There are more than three outer circumferential grooves on the cylindrical surface of the turntable, and more than three end surfaces on the right end of the turntable. The screw groove, the right end of the outer circumference screw groove communicates with the end surface screw groove; a central hole is provided on the turntable and the cylinder; the barrel includes a cylindrical plasticizing chamber and an injection cylinder, and the turntable is located in the plasticizing chamber and can rotate. The hopper is installed on the plasticizing chamber, the left end of the outer circumferential screw groove communicates with the hopper through a radial hole, and the end surface screw groove communicates with the right end of the outer circumferential screw groove and the left end of the injection barrel; the plunger and the injection barrel are in clearance fit. It has the advantages of simple and compact structure, easy cleaning of the barrel, strong plasticizing, crushing and extrusion capabilities, and good product quality.

Description

Screw plate and plunger combined injection molding device

technical field

The invention relates to a combined screw disk and plunger injection molding device, which is mainly used for plasticizing and injection molding polymer materials, and belongs to the technical field of polymer material injection molding.

Background technique

Plastic injection molding has the advantages of simple process, high production efficiency, and accurate product size, and can mold products with complex shapes in a short period of time.

The plasticizing injection device is one of the core structures of injection molding equipment. Its performance not only directly affects the efficiency of injection molding, production cost and production environment, but also has a decisive impact on the quality of injection products.

There are two kinds of the most common plasticizing injection devices at present, one is the screw plunger type, and the other is the reciprocating screw type.

The traditional screw plunger injection molding machine adds a set of single-screw extrusion feeding device only for plasticization to the plunger injection device. The material needs to be plasticized first through the single-screw plasticization device, and then It enters the injection barrel through the one-way valve. When the amount of material supplied reaches the measured value, the plasticizing screw stops rotating and the injection plunger starts to inject.

In the traditional reciprocating screw injection molding machine, the screw has two functions of plasticizing and injecting at the same time. The screw performs rotary motion to plasticize the material, and at the same time performs reciprocating axial motion to inject, so the complexity of the overall system is high. The cost is high, and during plasticization, along with the axial movement of the screw, the melt forms an insurmountable axial temperature difference.

Traditional injection machines also have a common feature, that is, the screw is generally used to plasticize the material. Although the plasticization of the screw has its advantages, for some materials, the screw has the disadvantage of not being strong in plasticizing, crushing and extruding.

Aiming at the problems existing in traditional injection machines, although many researchers have carried out explorations, they are all limited to local changes to the screw or plunger, without changing the fundamental reason for the existence of the above-mentioned overall system.

Among the many researchers, some researchers introduced vibration into the field of plastic processing and molding, and used the influence of screw vibration on the plasticizing extrusion process of materials to optimize the extrusion process and improve the quality of extruded products.

Some researchers use the vibration of plunger or piston to optimize the plasticizing, extrusion and injection process. Foreign literature ^[1,2] introduced the rheological injection molding machine developed by it. The polymer melt is first injected into the vibrating chamber from the barrel under the action of the screw, the direction of the valve is switched, and the vibration is applied by the piston. Then it is injected into the mold cavity by the piston, and while maintaining the pressure, the melt continues to be subjected to pressure vibration before the mold gate freezes.

To sum up, in the existing studies on the introduction of vibration in the injection and extrusion process, some optimize the injection and extrusion process by applying vibration to the screw, and some use the plunger or piston that is not installed in the same barrel as the screw. Vibration is applied to affect the polymer melt to improve the properties of the final product.

references:

[1 Ibar JP. Control of polymer properties by melt vibration technology: a review. Polymer Engineering and Science. 1998;38(1):1-20

[2] A.Minardi, M.Boudeulle, E.Duval, S Etienne. Effect of the molding conditions on the semicrystalline structure of polypropylene. Polymer. 1997,38(15):3957-3965.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a combination screw and plunger injection molding device, which has strong plasticizing, crushing and extrusion capabilities for various materials. The vibration is eliminated, the production process is improved, and the product quality is good.

In order to achieve the above object, the present invention is achieved in this way, it is a screw disk and plunger combined injection molding device, including injection cylinder, injection seat frame, motor, transmission mechanism, seat, centripetal thrust bearing, hopper, Machine barrel, electric heater, mobile oil cylinder, gear and plunger; the injection oil cylinder, motor, transmission mechanism and machine barrel are all installed on the injection seat frame, and the push rod of the mobile oil cylinder is connected with the injection seat frame; it is characterized in that It also includes a plasticizing screw disk, the plasticizing screw disk includes a turntable and a cylinder integrated with it, and more than three outer circumferential screw grooves are arranged on the cylindrical surface of the turntable, and three screw grooves are arranged on the right end surface of the turntable. The above end surface screw groove, the right end of the outer circumference screw groove communicates with the end surface screw groove; a central hole is provided on the turntable and the cylinder; the barrel includes a cylindrical plasticizing chamber and an injection cylinder, and the turntable is located The hopper is installed in the plasticizing chamber, the left end of the outer circumferential screw groove communicates with the hopper, and the end face screw groove communicates with the right end of the outer circumferential screw groove and the left end of the injection barrel; the centripetal thrust bearing and The gears are all installed on the cylinder of the plasticizing screw, and the centripetal thrust bearing is installed on the seat; the right end of the plunger passes through the center hole of the turntable and the cylinder and is located in the injection cylinder, and the plunger and the injection cylinder are in clearance fit , the plunger is axially movable in the center hole of the turntable and cylinder and in the injection barrel.

The combined screw disk and plunger injection molding device is characterized in that it also includes a motion controller and a vibration device, the motion controller controls the vibration of the vibration device, and the vibration device is installed on the pusher between the plunger and the injection cylinder. between poles.

In this technical solution, the movement of the plunger driven by the vibration device is: axial vibration, circular vibration, axial vibration and circular vibration at the same time, or the vibration device drives the plunger to perform circular rotation.

In this technical solution, it is divided into two different situations.

Case 1 of this technical solution, the inner hole of the injection cylinder is a straight through hole, the outer cylindrical surface of the right part of the plunger and the whole section of the inner hole of the injection cylinder have gaps through which the molten material can pass, and the plunger is in the injection cylinder. At any axial position, the plasticized melt can enter the right end through the gap under pressure.

In the second case of the technical solution, the inner hole of the injection cylinder is a stepped hole, the part with a large diameter in the stepped hole communicates with the plasticizing chamber, the part with a small diameter in the stepped hole communicates with the injection hole, and the outer part of the right part of the plunger There is a certain gap between the cylindrical surface and the part with a large diameter in the stepped hole, and the plasticized melt can enter the right section of the injection cylinder through this gap under pressure, and the outer cylindrical surface of the right part of the plunger and the part with a small diameter in the stepped hole It is a sliding fit but the melt cannot pass through the fit gap.

In another technical solution, a one-way valve or a non-return head is provided at the right end of the plunger to prevent the material from flowing backward, and the one-way valve or the non-return head is located in the injection barrel, and the one-way valve or the non-return head is located in the injection barrel. The syringe can move axially.

Compared with the prior art, the present invention has the following advantages:

1. The plasticizing part of the plasticizing screw adopts more than three cylindrical outer circumferential screw grooves + end surface screw groove structure. This method changes the traditional screw plasticizing method, and uses external thread grooves and end surface screw grooves to plasticize and extrude Material is a change and improvement in principle. It has the advantages of extrusion, crushing, mixing, and strong plasticizing ability, which is beneficial to the plasticization and melting of materials. This is especially beneficial for those materials that are difficult to plasticize. .

2. Introducing vibration into the injection molding process of polymer materials can significantly optimize the processing process, reduce the effective viscoelasticity and viscosity of the polymer material melt, increase the flow rate, strengthen the mixing and shearing of materials, and significantly improve the molding The performance of the product, through the mechanical properties, DSC and density tests of the injection molded product after the vibration is applied, it is found that the tensile and impact strength of the injection molded product increases, the density becomes larger, the crystallinity of the sample increases, and the internal quality and appearance quality of the product All have been greatly improved and improved.

3. Compared with other forms of vibration introduced in plastic processing and molding, this patent has the advantages of simple and reliable structure.

Description of drawings

Fig. 1 is a schematic structural view of Embodiment 1 of the present invention;

Fig. 2 is the structural representation of cylinder among Fig. 1;

Fig. 3 is the schematic structural view of the plasticizing screw disk in Fig. 1;

Fig. 4 is a schematic diagram of the screw groove on the end surface of the plasticizing screw disk in Fig. 3;

Fig. 5 is a schematic structural diagram of Embodiment 2 of the present invention;

Fig. 6 is a schematic structural diagram of Embodiment 3 of the present invention.

detailed description

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not constitute a conflict with each other.

In the description of the present invention, the orientations or positional relationships indicated by the terms "left" and "right" are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and do not require that the present invention must be based on a specific orientation. construction and operation, therefore, should not be construed as limiting the invention.

Embodiment one

As shown in Figures 1 to 4, it is a combined screw and plunger injection molding device, including an injection cylinder 1, an injection stand 2, a motor 3, a transmission mechanism 4, a seat 5, and a centripetal thrust bearing 6 , hopper 7, barrel 9, electric heater 10, mobile cylinder 13, gear 14 and plunger 15;

The injection cylinder 1, the motor 3 and the transmission mechanism 4 are all installed on the injection seat frame 2, and the push rod of the mobile oil cylinder 13 is connected with the injection seat frame 2, so that the push rod of the mobile oil cylinder 13 can push the injection seat frame 2 to move ;

Described plasticizing screw disk 8 comprises rotating disk 81 and cylinder 82, and described cylinder 82 is positioned at the left end of rotating disk 81, and is provided with more than three outer circumferential screw grooves 811 on the cylindrical surface of described rotating disk 81, on the rotating disk 81 The right end face is provided with more than three end face screw grooves 812, and the right end of the outer circumference screw groove 811 communicates with the end face screw groove 812; a central hole is provided on the rotating disk 81 and the cylinder 82; Groove 812 should be identical, can be three, four, five or more;

The barrel 9 is installed on the injection stand 2, the barrel 9 includes a cylindrical plasticizing chamber 91 and an injection cylinder 92, the turntable 81 is located in the plasticizing chamber 91 and can rotate, and the hopper 7 is installed in the plasticizing chamber 91. On the chamber 91, the left end of the outer circumferential screw groove 811 communicates with the hopper 7 through the radial hole on the plasticizing chamber 91, and the end face screw groove 812 communicates with the right end of the outer circumferential screw groove 811 and the left end of the injection cylinder 92; the outer circumferential screw groove 811 And the screw groove 812 on the end surface is used as a material crushing, mixing, grinding, plasticizing and transportation channel to complete the plasticizing and melting of the material;

The centripetal thrust bearing 6 and the gear 14 are all installed on the cylinder 82, and the centripetal thrust bearing 6 is installed on the seat 5; the right end of the plunger 15 passes through the center hole of the rotating disk 81 and the cylinder 82 and is positioned at the injection In the cylinder 92, the plunger 15 is in clearance fit with the injection cylinder 92, and the plunger 15 is axially movable in the center hole of the turntable 81 and the cylinder 82 and the injection cylinder 92.

In order to inject the molten material into the mold cavity in a pulsating manner, a motion controller 12 and a vibration device 11 are also included in this embodiment, the motion controller 12 controls the vibration of the vibration device 11, and the vibration device 11 is installed on the plunger 15 Between the top and the push rod of the injection cylinder 1; the movement of the plunger 15 driven by the vibration device 11 is: axial vibration, circular vibration, axial vibration and circular vibration at the same time, or the vibration device 11 drives the plunger 15 to perform circular motion.

When working, the motor 3 drives the plasticizing screw disk 8 to rotate through the transmission mechanism 4 and the gear 14. The outer circumferential thread groove 811 and the end surface spiral groove 812 on the plasticizing screw disk 8 are used as materials for crushing, mixing, grinding, plasticizing and conveying. The material in the hopper 7 enters the outer circumferential thread groove 811 through the radial feed hole of the plasticizing chamber 91 of the barrel 9, moves to the right under the push of the rotating screw edge, and then enters the end surface spiral groove 812, and then goes along the The spiral groove 812 on the end surface moves toward the center of the circle, and finally moves toward the injection nozzle in the injection cylinder 92. After the system completes the mold clamping process, the moving cylinder 13 drives the injection seat frame 2 to move to the right, and drives the injection cylinder 1, motor 3, The overall plasticizing injection system including the transmission mechanism 4 and the barrel 9 moves to the right until the injection nozzle is connected with the mold, and then the pressure oil is injected into the injection cylinder 1 to push the vibration device 11 and the plunger 15 in the The injection cylinder 92 of the machine barrel 9 makes a linear motion, and at the same time, the vibrating device 11 will drive the plunger 15 to vibrate, inject the molten material in the injection cylinder 92 into the mold cavity in a pulsating manner, and make the plunger 15 continuously Pressurization and feeding, the vibration of the plunger 15 is maintained until the workpiece is cooled and shaped in the mold cavity; then the plunger 15 retreats from the injection barrel 92 of the barrel 9, and the rotating screw 8 starts the next round of plasticizing motion .

Embodiment two

As shown in Figure 5, it is a combination screw and plunger injection molding device, its structure and working principle are basically the same as the first embodiment, the difference is that the injection cylinder 92 is a stepped hole , the portion with a larger aperture in the stepped hole communicates with the plasticizing chamber 91, the portion with a smaller aperture in the stepped hole communicates with the injection hole, and there is a certain gap between the outer circular surface of the right part of the plunger 15 and the section with a larger aperture in the stepped hole. The melted material that has been plasticized can enter the right section of the injection cylinder 92 through the gap under pressure, and the outer circular surface of the right part of the plunger 15 is in a sliding fit with the part of the stepped hole of the injection cylinder 92 with a small diameter, but the melted material cannot It passes through the matching gap, but the volume of the small hole in the stepped hole must be greater than the minimum injection volume set by the injection machine. The working principle is basically the same as that of Embodiment 1, and will not be repeated here.

Embodiment Three

As shown in Figure 6, it is a combined screw and plunger injection molding device. Its structure and working principle are basically the same as those in Embodiment 1, except that a one-way valve 16 is installed at the right end of the plunger 15. (or the non-return head 16 ), the one-way valve 16 (or the non-return head 16 ) is located in the injection cylinder 92 , and the one-way valve 16 (or the non-return head 16 ) can move axially in the injection cylinder 92 . The non-return head is a device to prevent the molten material from flowing back during injection. Its working principle is very similar to that of a one-way valve. Since this technology is relatively mature and is not the focus of this patent, the structure of the non-return head will not be discussed here. The principle is described.

When working, the motor 3 drives the plasticizing screw disk 8 to rotate through the transmission mechanism 4 and the gear 14. The outer circumferential thread groove 811 and the end surface spiral groove 812 on the plasticizing screw disk 8 are used as materials for crushing, mixing, grinding, plasticizing and conveying. The material in the hopper 7 enters the outer circumferential thread groove 811 through the feed hole of the plasticizing chamber 91 of the barrel 9, moves to the right under the push of the rotating screw edge, and then enters the end surface spiral groove 812, and then spirals along the end surface. The groove 812 moves towards the center of the circle, and finally moves to the right along the injection cylinder 92 of the barrel 9, and fills the front end of the injection barrel 92 on the right side of the barrel 9 through the one-way valve 16 (or check head 16) at the right end of the plunger 15 ; After the system completes the mold clamping process, the moving cylinder 13 drives the injection seat frame 2 to move to the right, and drives the overall plasticizing injection system including the injection cylinder 1, the motor 3, the transmission mechanism 4 and the barrel 9 to move to the right, Until the injection nozzle is connected with the mold, and then the pressure oil is introduced into the injection cylinder 1, and the plunger 15 and the check valve 16 (or the non-return head 16) are pushed to make a linear motion in the injection cylinder 92 of the barrel 9. At the same time, the vibration device 11 will drive the plunger 15 and the one-way valve 16 (or the check valve 16) to vibrate, inject the molten material in the injection cylinder 92 of the barrel 9 into the mold cavity in a pulsating manner, and make the one-way valve 16 vibrate. Carry out continuous pressure maintenance and feeding to the valve or check head 16, and its vibration is maintained until the workpiece is cooled and shaped in the mold cavity; then the plunger 15 drives the check valve 16 (or check head 16) from the barrel 9 The injection cylinder 92 retreats, and the plasticizing screw disk 8 starts the next round of rotary plasticizing motion.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and deformations to these implementations without departing from the principle and spirit of the present invention still fall within the protection scope of the present invention.

Claims (6)

1. A combined screw and plunger injection molding device, including an injection cylinder (1), an injection stand (2), a motor (3), a transmission mechanism (4), a seat (5), and a radial thrust bearing (6), hopper (7), barrel (9), electric heater (10), mobile cylinder (13), gear (14) and plunger (15); the injection cylinder (1), motor (3) , the transmission mechanism (4) and the machine barrel (9) are installed on the injection seat (2), and the push rod of the mobile cylinder (13) is connected with the injection seat (2); it is characterized in that it also includes a plasticizing screw Disk (8), the plasticizing screw disk (8) includes a turntable (81) and a cylinder (82) integrated with it, and more than three outer circumferential screw grooves are provided on the cylindrical surface of the turntable (81) (811), there are more than three end surface screw grooves (812) on the right end surface of the turntable (81), and the right end of the outer circumference screw groove (811) communicates with the end surface screw groove (812); on the turntable (81) and the cylinder (82) is provided with a central hole; the barrel (9) includes a cylindrical plasticizing chamber (91) and an injection cylinder (92), and the turntable (81) is located in the plasticizing chamber (91) and Rotatable, the hopper (7) is installed on the plasticizing chamber (91), the left end of the outer circumferential screw groove (811) communicates with the hopper (7), and the end face screw groove (812) communicates with the outer circumferential screw groove (811) The right end and the left end of the injection barrel (92); the centripetal thrust bearing (6) and the gear (14) are installed on the cylinder (82), and the centripetal thrust bearing (6) is installed on the seat (5); The right end of the plunger (15) passes through the center hole of the turntable (81) and the cylinder (82) and is located in the injection cylinder (92), the plunger (15) is in clearance fit with the injection cylinder (92), and the plunger (15) ) in the center hole of the turntable (81) and the cylinder (82) and the injection barrel (92) and can move axially. 2. The combined screw and plunger injection molding device according to claim 1, characterized in that it also includes a motion controller (12) and a vibration device (11), and the motion controller (12) controls the vibration device ( 11) vibration, the vibration device (11) is installed between the plunger (15) and the push rod of the injection cylinder (1). 3. The combined screw and plunger injection molding device according to claim 2, characterized in that the movement of the plunger (15) driven by the vibration device (11) is: axial vibration, circular vibration, and simultaneous Axial vibration and circular vibration, or the vibration device (11) drives the plunger (15) to perform circular rotation. 4. The combined screw and plunger injection molding device according to claim 1, characterized in that the inner hole of the injection barrel (92) is a straight through hole, and the outer cylindrical surface of the right part of the plunger (15) is in contact with The entire inner hole of the injection cylinder (92) has gaps through which the molten material can pass. When the plunger (15) is in any axial position of the injection cylinder (92), the plasticized molten material can pass through under pressure. The gap goes into the right end. 5. The combined screw and plunger injection molding device according to claim 1, characterized in that the inner hole of the injection cylinder (92) is a stepped hole, and the part with a large diameter in the stepped hole is connected with the plasticizing cavity (91 ) is connected, the part with small diameter in the stepped hole is connected with the injection hole, and there is a gap between the outer cylindrical surface of the right part of the plunger (15) and the part with large diameter in the stepped hole, and the plasticized molten material can pass through under pressure. This gap enters the right section of the injection barrel (92), and the outer cylindrical surface of the right part of the plunger (15) is slidingly fitted with the small portion of the stepped hole, but the molten material cannot pass through the fitting gap. 6. The combined screw and plunger injection molding device according to claim 1, characterized in that a one-way valve or a check head (16) is provided at the right end of the plunger (11) to prevent material backflow, The one-way valve or the non-return head (16) is located in the injection cylinder (92), and the one-way valve or the non-return head (11) can move axially in the injection cylinder (92).