A material tube assembly for an injection molding machine injection system

Abstract

This invention discloses a material tube assembly for an injection molding machine injection system, including a locking platen, a melt cylinder, a nozzle, and a nozzle flange. The locking platen has a locking cavity, and the nozzle is fixed to the nozzle flange for injection. The front end of the melt cylinder has a flange connection portion integrally forged therewith. The outer diameter of the flange connection portion is smaller than the inner diameter of the locking cavity. The flange connection portion is connected and fastened to the nozzle flange, whose outer diameter is smaller than the inner diameter of the locking cavity, by several fasteners. The fastening force between the flange connection portion and the nozzle flange is sufficient to overcome the injection force generated when the nozzle injects material. This invention, by connecting the flange connection portion integrally formed with the melt cylinder to the nozzle flange, and ensuring that the fastening force between the flange connection portion and the nozzle flange overcomes the injection force generated when the nozzle injects material, allows the front end assembly of the melt cylinder to extend into the locking cavity without lengthening the nozzle, shortening the injection flow path and thus reducing the injection pressure loss during injection.

Description

Technical Field

[0001] This invention relates to the field of injection molding machine technology, and in particular to a material tube assembly for an injection system of an injection molding machine. Background Technology

[0002] Currently, the injection system tubing assembly of large injection molding machines includes a locking platen and a plasticizing device with melting and injection functions. The plasticizing device includes a melting cylinder, a connecting nut, and an injection device. The injection device includes a nozzle and a nozzle flange. The nozzle flange is tightened by the connecting nut, which is threaded to the outer wall of the melting cylinder. To accommodate enough screws to overcome the injection force generated when the injection device injects the material, the connecting nut is relatively large, preventing it from extending into the cavity of the locking platen. This results in a large nozzle flange, which also cannot extend into the cavity of the locking platen. Because the cavity of the locking platen is affected by the clamping force, its size cannot be adjusted according to the nozzle flange size (enlarging the cavity would cause deformation during mold closing). Since the nozzle needs to pass through the cavity of the locking platen, the only solution is to lengthen the nozzle to extend into and out of the cavity of the locking platen to inject the melt (plasticized material) into the mold cavity. However, lengthening the overall size of the nozzle is equivalent to lengthening the injection channel (which is formed by the inner cavity of the nozzle and the inner cavity of the nozzle flange), resulting in a greater loss of injection pressure during injection. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a material tube assembly for an injection system of an injection molding machine, which can effectively reduce the injection pressure loss of the nozzle during injection and save costs.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A feed tube assembly for an injection molding machine's injection system includes a locking platen and a plasticizing device. The locking platen has a locking cavity. The plasticizing device includes a melt cylinder, a nozzle, and a nozzle flange. The outer diameter of the nozzle is smaller than the outer diameter of the nozzle flange and is axially fixed to the nozzle flange for injecting glue. The front end of the melt cylinder has a flange connection portion integrally forged therewith. The outer diameter of the flange connection portion is smaller than the inner diameter of the locking cavity. The flange connection portion is connected and fastened to the nozzle flange, whose outer diameter is smaller than the inner diameter of the locking cavity, by a plurality of fasteners. The fastening force between the flange connection portion and the nozzle flange is sufficient to overcome the injection force generated when the nozzle injects glue.

[0006] Furthermore, a number of spaced heating elements are fitted onto the outer wall of the flange connection.

[0007] Furthermore, the gap between two adjacent heating elements is 5–6 mm.

[0008] Furthermore, the inner diameter of the flange connection is the same as the inner diameter of the melt cylinder.

[0009] Furthermore, the inner cavity of the nozzle is connected to the inner cavity of the nozzle flange to form an injection channel. The end of the nozzle flange facing away from the nozzle is connected and fastened to the end of the flange connection facing away from the molten glue cylinder by a plurality of fasteners. The inner cavity of the flange connection is connected to the injection channel.

[0010] Furthermore, a rotatable melting screw is provided inside the melting cylinder so that a melting chamber is formed between the melting cylinder and the melting screw.

[0011] Furthermore, the melting screw can also be moved back and forth inside the melting cylinder. The front end of the melting screw is threadedly connected to a glue-passing head. When the melting action is performed, the glue-passing head moves back with the melting screw and forms a metering chamber with the glue injection channel.

[0012] Furthermore, the glue-passing head has a connecting shaft and an extrusion part. The extrusion part is located at the front end of the connecting shaft. The extrusion part has several glue-passing grooves along its circumference. The connecting shaft is used to connect with the melting screw. A glue-passing cylinder is sleeved on the connecting shaft. One end of the glue-passing cylinder has several protrusions along its circumference. Each protrusion is inserted into a glue-passing groove and has a gap with the glue-passing groove under the limiting action of the inner wall of the flange connection. The other end of the glue-passing cylinder can fit with the sealing gasket sleeved on the connecting shaft and seal the glue material in the melting chamber into the metering chamber during the glue injection action.

[0013] Furthermore, the outer wall of the connecting shaft is provided with an annular protrusion arranged along its circumference, and the sealing gasket is limited between the annular protrusion and the molten adhesive screw.

[0014] Furthermore, the outer diameter of the flange connection is the same as the outer diameter of the nozzle flange.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention utilizes the characteristics of the molding blank formed by the melt cylinder. A flange connection part is designed and integrally forged at its front end. The fastening force between the flange connection part and the nozzle flange is sufficient to overcome the injection force generated when the nozzle injects glue. Therefore, the front end component of the melt cylinder can be extended into the mold cavity without lengthening the nozzle, thereby shortening the glue flow channel and reducing the injection pressure loss of the nozzle during glue injection, thus achieving the effect of saving costs. Attached Figure Description

[0017] Figure 1This is a cross-sectional view of the material tube assembly for the injection system of the injection molding machine of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the connection between the melt cylinder and the flange in a specific embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the plasticizing device in a specific embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the adhesive applicator structure in a specific embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the coating tube involved in a specific embodiment of the present invention.

[0022] In the diagram: 10, Melting cylinder; 101, Flange connection; 1011, Heating element; 102, Heating coil; 103, Feed port; 11, Nozzle; 110, Injection channel; 12, Nozzle flange; 20, Locking plate; 201, Locking cavity; 30, Fastener; 40, Melting screw; 50, Sealing gasket; 60, Glue feed head; 601, Connecting shaft; 602, Extrusion section; 6021, Glue feed groove; 603, Annular protrusion; 70, Glue feed cylinder; 701, Protrusion. Detailed Implementation

[0023] The present invention will now be described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0024] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "horizontal," "vertical," "top," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Implementation method:

[0027] Please refer to Figure 1-5 This invention discloses a material tube assembly for an injection molding machine injection system, including a locking platen and a plasticizing device. The locking platen 20 has a locking cavity 201. The plasticizing device includes a melt cylinder 10, a nozzle 11, and a nozzle flange 12. The outer diameter of the nozzle 11 is smaller than the outer diameter of the nozzle flange 12 and is fixed to the nozzle flange 12 along its axial direction for injecting glue. The front end of the melt cylinder 10 has a flange connection part 101 integrally forged therewith. The outer diameter of the flange connection part 101 is smaller than the inner diameter of the locking cavity, and the outer diameter of the flange connection part 101 is the same as the outer diameter of the nozzle flange 12, so that the flange connection part 101 can extend into the locking cavity. The flange connection 101 is connected and fastened to the nozzle flange 12, whose outer diameter is smaller than the inner diameter of the mold cavity, by a number of fasteners 30, so that the nozzle flange 12 can also extend into the mold cavity. While both the flange connection 101 and the nozzle flange 12 can extend into the mold cavity, the fastening force between the flange connection 101 and the nozzle flange 12 can overcome the injection force generated when the nozzle 11 injects glue. Therefore, the front end component of the melt cylinder can be extended into the mold cavity without lengthening the nozzle 11, thereby shortening the glue flow channel 110 and reducing the injection pressure loss of the nozzle 11 during glue injection, thus achieving the effect of saving costs.

[0028] It should be noted that the fasteners 30 used for the flange connection 101 and the nozzle flange 12 are fastening screws. In this art, the connection between the flange connection 101 and the nozzle flange 12 requires 30 fastening screws, each with a torque of 270N, to fasten the flange connection 101 and the nozzle flange 12 in order to overcome the injection force generated when the nozzle 11 injects adhesive. Specifically, the 30 fastening screws form two circles around the circumference of the nozzle flange 12, with 15 screws forming one circle. The two circles of fastening screws are inner and outer ring fastening screws. Those skilled in the art will understand that by sequentially inserting the inner and outer ring fastening screws through the nozzle flange 12 and the flange connection 101 and fastening them, the injection force generated when the nozzle 11 injects adhesive can be overcome. The conventional nozzle flange 12 is connected to the connecting nut on the outer wall of the melt cylinder 10 by the aforementioned fastening screws. In order to overcome the injection force generated when the nozzle 11 injects glue, the outer diameter of the connecting nut is larger than the inner cavity of the mold locking plate (mold locking cavity). This results in the overall size of the conventional nozzle flange 12 being larger, which means that the front end assembly of the conventional melt cylinder 10 cannot extend into the mold locking cavity. It is only possible to extend into the mold locking cavity by lengthening the nozzle 11. Therefore, the inventors replaced the traditional connecting nut by designing an integrally forged flange connection 101 at the front end of the melt cylinder. Since the flange connection 101 and the melt cylinder are integrally forged, the outer diameter of the flange connection 101 is smaller than that of the traditional connecting nut, allowing the flange connection 101 to extend into the mold cavity. At the same time, the nozzle flange 12 connected to the flange connection 101 can also extend into the mold cavity. This allows the material tube assembly of the injection system of the injection molding machine of the present invention to extend the front end assembly of the melt cylinder into the mold cavity without lengthening the nozzle 11, thereby shortening the injection flow channel 110 and reducing the injection pressure loss of the nozzle 11 during injection. In addition, since the nozzle 11 does not need to be lengthened, the present invention can also save materials and reduce production costs.

[0029] It is worth noting that, since a heating coil 102 needs to be fitted on the outer wall of the nozzle 11, and the present invention does not require lengthening the nozzle 11, the heating coil 102 on the nozzle 11 of the present invention transfers heat to its inner wall more efficiently. At the same time, the present invention requires fewer heating coils to be fitted on the nozzle 11 than the traditional method, which not only saves the electricity used for heating the heating coils, but also reduces the amount of material used and lowers the cost compared to manufacturing a traditional nozzle 11.

[0030] In this embodiment, a plurality of spaced heating elements 1011 are fitted onto the outer wall of the flange connection 101. These heating elements 1011 are used to heat the flange connection 101, transferring heat into the inner wall of the flange connection 101 to heat the adhesive material within the flange connection 101 cavity, thereby improving the plasticizing effect of the adhesive material. The gap between two adjacent heating elements is 5-6 mm, which improves the efficiency of heating the adhesive material and further enhances the plasticizing effect.

[0031] In this embodiment, the inner diameter of the flange connection 101 is the same as the inner diameter of the melting cylinder. Since a rotatable and movable melting screw 40 is installed inside the melting cylinder, the melting screw 40 rotates within the melting cylinder 10, forming a melting chamber with the inner wall of the melting cylinder 10. Therefore, it can be understood that the plastic material enters the melting cylinder 10 through the feed port 103, and the melting screw 40 is driven by a motor (not shown) to rotate within the melting cylinder 10, thus conveying, compacting, melting, stirring, and pressurizing the plastic. Simultaneously, when the melting screw 40 rotates, friction and mutual movement occur between the plastic and the inner wall of the melting cylinder 10, the bottom surface of the screw groove of the melting screw 40, the screw ridge propelling surface, and between the plastic materials themselves. The heat generated by this friction is absorbed to increase the temperature of the plastic and melt it, thereby achieving the purpose of plasticizing the plastic.

[0032] In this embodiment, the inner cavity of the nozzle 11 communicates with the inner cavity of the nozzle flange 12 to form an injection channel 110. The end of the nozzle flange 12 facing away from the nozzle 11 is connected and fastened to the end of the flange connection 101 facing away from the melting cylinder by the aforementioned fastening screw. The inner cavity of the flange connection 101 communicates with the injection channel 110. The front end of the melting screw is threadedly connected to a pass-through head 60. During the melting process, the pass-through head 60 retracts with the melting screw 40 and forms a metering chamber with the injection channel 110. In other words, the injection molding machine's control system drives the melting screw 40 to rotate within the melting cylinder 10 to melt and plasticize the material and bring it to the front end of the screw. As the amount of molten material at the front end of the screw increases, the pressure of the molten material increases due to the limited volume, pushing the melting screw 40 backward and allowing the plasticized material (melt) to enter the metering chamber, thus completing the metering of the melt.

[0033] In this embodiment, the glue-passing head 60 has a connecting shaft 601 and an extrusion part 602. The extrusion part 602 is located at the front end of the connecting shaft 601. The extrusion part 602 has a plurality of glue-passing grooves 6021 along its circumference. The connecting shaft 601 is used to connect with the melting screw. A glue-passing cylinder 70 is sleeved on the connecting shaft 601. A plurality of protrusions 701 are provided on one end of the glue-passing cylinder 70 along its circumference. Each protrusion 701 is inserted into each glue-passing groove 6021 and has a gap with the glue-passing groove 6021 under the limiting action of the inner wall of the flange connection part 101. The other end of the glue-passing cylinder can fit with the sealing gasket sleeved on the connecting shaft and seal the glue material in the melting chamber into the metering chamber during the glue injection action. Therefore, those skilled in the art can understand that after the glue melting is completed, the melt enters the glue-passing cylinder 70 through the gap between the sealing gasket 50 and the glue-passing cylinder 70, and then enters the glue injection channel 110 through the gap between the protrusion 701 and the glue-passing groove 6021. It is a well-known technique in the art to use the pressure in the metering chamber to be greater than the pressure in the melting chamber during the glue injection action. Therefore, the pressure difference between the metering chamber and the melting chamber can be used to move the glue-passing cylinder 70 backward, so that the glue-passing cylinder 70 and the sealing gasket 50 are in contact, thereby achieving the effect of sealing the glue material in the melting chamber and allowing it to enter the metering chamber.

[0034] In summary, the working principle of the plasticizing device is as follows: During pre-plasticizing, the motor (not shown) drives the melting screw 40 to rotate, continuously pushing the plastic falling from the feed port 103 on the melting cylinder into the screw channel (the gap between the melting screw and the inner wall of the melting cylinder) forward. The heating coil 102 on the outer wall of the melting cylinder 10 transfers heat to the plastic inside the melting cylinder 10. Under the dual action of external heating and the rotation and shearing of the melting screw, and after passing through the thermal process of each functional section of the melting screw, the plastic achieves plasticization and melting. During the melting process, the plasticized material flows through the glue cylinder 70 and into the front end of the glue head 60 under the action of the melting screw, generating back pressure and pushing the screw backward to complete the metering of the melt. After the melting is completed, the motor drives the melting screw to move forward and push the melt into the flow channel of the injection device and then inject it into the mold cavity.

[0035] In this embodiment, an annular protrusion 603 is provided on the outer wall of the connecting shaft 601 along its circumference. The sealing gasket 50 is limited between the annular protrusion 603 and the molten adhesive screw. The annular protrusion 603 is engaged with the front end of the molten adhesive screw to facilitate the limiting and fixing of the sealing gasket 50.

[0036] Working principle of the invention:

[0037] Plastic enters the melting cylinder 10 through the feed port and is heated by the heating coil 102. Under high temperature conditions, the plastic is subjected to external force, causing the melting screw 40 to rotate within the melting cylinder 10. This process conveys, compacts, melts, stirs, and pressurizes the plastic. Simultaneously, as the melting screw 40 rotates, friction and mutual movement occur between the plastic and the inner wall of the melting cylinder 10, the screw, and between the plastic components. The heat generated by this friction is absorbed to raise the plastic temperature and melt it. Under the action of rotation, the granular plastic is turned into a molten state and extruded into the front cavity of the melt cylinder 10; the melt screw 40 is continuously retracted under the force of the plastic at the front end until a certain amount is reached, and the molten plastic is injected into the mold cavity through the injection channel 110. After cooling, the desired plastic product is formed. During the injection process, the sealing gasket 50 and the glue tube 70 are in contact to prevent the molten plastic from flowing back; and the fastening screw connects the nozzle flange 12 and the flange connection part 101 of the melt cylinder 10 to overcome the injection force generated by the nozzle 11 during injection.

[0038] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A material tube assembly for an injection molding machine injection system, comprising a locking platen (20) and a plasticizing device, wherein the locking platen (20) has a locking cavity (201), and the plasticizing device comprises a melting cylinder (10), a nozzle (11), and a nozzle flange (12), wherein the outer diameter of the nozzle (11) is smaller than the outer diameter of the nozzle flange (12) and is fixedly mounted on the nozzle flange (12) axially for injection, characterized in that: The front end of the melt cylinder (10) has a flange connection part (101) integrally forged therewith. The outer diameter of the flange connection part (101) is smaller than the inner diameter of the mold cavity (201). The flange connection part (101) is connected and fastened to the nozzle flange (12) whose outer diameter is smaller than the inner diameter of the mold cavity (201) by a number of fasteners (30). The fastening force between the flange connection part (101) and the nozzle flange (12) is sufficient to overcome the injection force generated when the nozzle (11) injects glue. The inner diameter of the flange connection (101) is the same as the inner diameter of the melt cylinder (10); The inner cavity of the nozzle (11) is connected to the inner cavity of the nozzle flange (12) to form a glue injection channel (110). The end of the nozzle flange (12) facing away from the nozzle (11) is connected and fastened to the end of the flange connection part (101) facing away from the melt cylinder (10) by a plurality of fasteners (30). The inner cavity of the flange connection part (101) is connected to the glue injection channel (110). The melt cylinder (10) is provided with a rotatable melt screw (40) so that a melt chamber is formed between the melt cylinder (10) and the melt screw (40); The melt screw (40) can also be moved back and forth inside the melt cylinder (10). The front end of the melt screw (40) is threadedly connected to a glue-passing head (60). When the melt is being melted, the glue-passing head (60) moves back with the melt screw (40) and forms a metering chamber with the glue injection channel (110). The glue-passing head (60) has a connecting shaft (601) and an extrusion part (602). The extrusion part (602) is located at the front end of the connecting shaft (601). The extrusion part (602) has several glue-passing grooves (6021) along its circumference. The connecting shaft (601) is used to connect with the melting screw (40) by thread. A glue-passing cylinder (70) is sleeved on the connecting shaft (601). One end of the glue-passing cylinder (70) has several protrusions (701) along its circumference. Each protrusion (701) is inserted into each glue-passing groove (6021) and has a gap with the glue-passing groove (6021) under the limiting action of the inner wall of the flange connection part (101). The other end of the glue-passing cylinder (70) can fit with the sealing gasket (50) sleeved on the connecting shaft (601) and close the glue material in the melting chamber into the metering chamber during the glue injection action.

2. The material tube assembly for an injection molding machine injection system as described in claim 1, characterized in that: A number of spaced heating elements (1011) are fitted on the outer wall of the flange connection (101).

3. The material tube assembly for an injection molding machine injection system as described in claim 2, characterized in that: The gap between two adjacent heating elements (1011) is 5-6 mm.

4. The material tube assembly for an injection molding machine injection system as described in claim 1, characterized in that: The outer wall of the connecting shaft (601) is provided with an annular protrusion (603) arranged along its circumference, and the sealing gasket (50) is limited between the annular protrusion (603) and the melt screw (40).

5. The material tube assembly for an injection molding machine injection system as described in claim 1, characterized in that: The outer diameter of the flange connection (101) is the same as the outer diameter of the nozzle flange (12).

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