Injection molding method and injection molding machine nozzle

Abstract

This invention discloses an injection molding method and an injection molding machine spraying device. The injection molding method includes: closing the injection mold and aligning the nozzle of the injection molding machine spraying device with the sprue of the injection mold; moving the valve needle of the injection molding machine spraying device from the closed position (nozzle closed) to the open position (nozzle open) to inject molten injection material into the cavity of the injection mold; after the cavity is filled with molten injection material, moving the valve needle from the open position to the closed position, such that the front end of the valve needle is inserted into the sprue and slightly embedded in the injection-molded part; after the injection-molded part has cooled and solidified, moving the valve needle back from the closed position to the disengaged position (disengaged from the injection-molded part); opening the injection mold and removing the injection-molded part from the injection mold. This invention utilizes the valve needle to remove injection material from the sprue, ensuring that the cooled and solidified injection-molded part does not have a protrusion corresponding to the sprue, thus improving injection molding efficiency and the quality of the injection-molded part.

Description

Technical Field

[0001] This invention relates to an injection molding method for injection molded products and an injection molding machine spraying device for injecting molten injection molding material into an injection mold. Background Technology

[0002] In existing technology, during injection molding, the injection molding machine nozzle is first connected to the sprue of the injection mold, and then the nozzle is opened to inject molten molding material into the mold cavity. After the molding material in the mold cools and solidifies, the mold can be opened and the molded product removed. However, in existing technology, the sprue of the injection mold is also filled with molding material during the injection process, which results in a protrusion on the molded product corresponding to the sprue. Therefore, in existing technology, this protrusion needs to be removed before demolding, which not only reduces injection molding efficiency but also reduces the quality of the molded product because cutting the protrusion can cause defects such as stringing on the product. Summary of the Invention

[0003] The purpose of this invention is to solve at least one aspect of the aforementioned problems and defects existing in the prior art.

[0004] According to one aspect of the present invention, an injection molding method is provided. The injection molding method includes the following steps:

[0005] S11: Close the injection mold and connect the nozzle of the injection molding machine's spraying device to the sprue of the injection mold;

[0006] S12: Move the valve needle of the injection molding machine spraying device from the closed position of the spraying hole of the nozzle to the open position of the spraying hole of the nozzle to inject molten injection material into the cavity of the injection mold;

[0007] S13: After the cavity of the injection mold is filled with molten injection material, the valve needle is moved from the open position to the closed position, so that the front end of the valve needle is inserted into the sprue and slightly embedded in the injection molded product.

[0008] S14: After the injection-molded product has cooled and solidified, the valve needle is moved back from the closed position to a disengaged position, separating it from the injection-molded product; and

[0009] S15: Open the injection mold and remove the injection molded product from the injection mold.

[0010] According to an exemplary embodiment of the present invention, in step S14, the valve needle moves back from the closed position to the disengaged position by a distance slightly greater than the embedding depth of the valve needle's front end into the injection molded article.

[0011] According to another exemplary embodiment of the present invention, the valve needle moves back from the closed position to the disengaged position by a distance within the range of 0.1 mm to 1.0 mm.

[0012] According to another exemplary embodiment of the present invention, in step S13, the embedding depth of the front end of the valve needle into the injection molded article is within the range of 0.05 mm to 0.2 mm.

[0013] According to another exemplary embodiment of the present invention, in step S14, when the valve needle is moved to the disengaged position, the injection orifice of the nozzle is still in the closed state, which is closed by the valve needle.

[0014] According to another aspect of the present invention, an injection molding machine sprue device is provided. The injection molding machine sprue device includes: a nozzle having an end adapted to abut with a sprue of an injection mold and a spray hole formed in said end; a valve needle movably disposed in said nozzle for opening and closing said spray hole; and a drive device adapted to drive the valve needle to move between an open position (opening the spray hole) and a closed position (closing the spray hole). After the cavity of the injection mold is filled with molten injection material, the drive device drives the valve needle from the open position to the closed position, such that the front end of the valve needle is inserted into the sprue and slightly embedded in the injection-molded article; after the injection-molded article has cooled and solidified, the drive device drives the valve needle back from the closed position to a disengaged position (disengaged from the injection-molded article).

[0015] According to an exemplary embodiment of the present invention, the distance by which the valve needle moves back from the closed position to the disengaged position is slightly greater than the embedding depth of the valve needle's front end into the injection molded article.

[0016] According to another exemplary embodiment of the present invention, the valve needle moves back from the closed position to the disengaged position by a distance within the range of 0.1 mm to 1.0 mm.

[0017] According to another exemplary embodiment of the present invention, the front end of the valve needle is embedded in the injection molded article to a depth within the range of 0.05 mm to 0.2 mm.

[0018] According to another exemplary embodiment of the present invention, when the valve needle is moved to the disengaged position, the injection orifice of the nozzle remains in the closed state, which is closed by the valve needle.

[0019] According to another exemplary embodiment of the present invention, the driving device includes a linear electric cylinder and a controller for controlling the linear electric cylinder, wherein the mover of the linear electric cylinder is connected to the valve needle, such that the valve needle can move linearly together with the mover.

[0020] According to another exemplary embodiment of the present invention, the driving device includes a servo motor, a transmission mechanism connected between the servo motor and the valve needle, and a controller for controlling the servo motor. The transmission mechanism is used to convert the rotational motion of the servo motor into linear movement of the valve needle.

[0021] According to another exemplary embodiment of the present invention, the driving device includes a cylinder, the cylinder comprising: a cylinder body having a first inner cavity; and a first piston member movably disposed in the first inner cavity and movable between a first position and a second position. When the first piston member is moved from the first position to the second position, the valve needle is moved by the first piston member from the open position to the closed position.

[0022] According to another exemplary embodiment of the present invention, a second inner cavity, isolated from the first inner cavity, is further formed in the cylinder body; the cylinder further includes a second piston member movably disposed in the second inner cavity. The second piston member is used to push the first piston member from the second position to the third position. When the first piston member is pushed from the second position to the third position by the second piston member, the valve needle is moved from the closed position to the disengaged position by the first piston member.

[0023] According to another exemplary embodiment of the present invention, the first piston member has a first piston rod connected to the valve needle, and the second piston member has a second piston rod, the second piston rod being movable between an extended position and a retracted position; when the second piston rod moves from the retracted position to the extended position, the first piston member is pushed from the second position to the third position by the second piston member; when the first piston member is moved from the first position to the second position, the second piston rod is pushed from the extended position to the retracted position by the first piston member.

[0024] According to another exemplary embodiment of the present invention, two first gas passages communicating with the first inner cavity and a second gas passage communicating with the second inner cavity are formed in the cylinder body, the two first gas passages and the second gas passage being used to connect to a gas control circuit.

[0025] According to another exemplary embodiment of the present invention, the drive device further includes a gas control circuit. The gas control circuit is connected to two first gas passages and one second gas passage of the cylinder, and is used to control the movement of the first piston and the second piston.

[0026] According to another exemplary embodiment of the present invention, the gas control circuit includes: a gas source; a pipeline connected between the gas source and the cylinder; a solenoid valve disposed on the pipeline; and a controller for controlling the solenoid valve.

[0027] According to another aspect of the present invention, an injection molding method is provided. The injection molding method includes the following steps:

[0028] S21: Provide the aforementioned injection molding machine spraying device;

[0029] S22: Connect the nozzle of the injection molding machine spraying device to the sprue of the injection mold;

[0030] S23: Move the first piston of the cylinder from the second position to the first position, so that the valve needle moves from the closed position to the open position, so as to inject molten injection material into the cavity of the injection mold;

[0031] S24: After the cavity of the injection mold is filled with molten injection material, the first piston is moved from the first position to the second position, so that the valve needle moves from the open position to the closed position;

[0032] S25: After the injection-molded product has cooled and solidified, the first piston is pushed to a third position by the second piston, causing the valve needle to move to a disengagement position from the injection-molded product; and

[0033] S26: Open the injection mold and remove the injection molded product from the injection mold.

[0034] In the foregoing exemplary embodiments of the present invention, after the injection mold is filled with molten injection material, the front end of a valve needle is inserted into the sprue of the injection mold, and the molten injection material in the sprue is discharged by the valve needle, thereby ensuring that the cooled and molded injection-molded product has no protrusion corresponding to the sprue. Therefore, the present invention eliminates the need to cut the protrusion caused by the sprue, which not only improves injection molding efficiency but also improves the quality of the injection-molded product.

[0035] Other objects and advantages of the invention will become apparent from the following description of the invention with reference to the accompanying drawings, and will help to provide a comprehensive understanding of the invention. Attached Figure Description

[0036] Figure 1 This diagram shows a schematic of an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the valve needle is in the closed position of the nozzle and the nozzle is connected to the sprue of the closed injection mold;

[0037] Figure 2 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the valve needle is in the open position of the nozzle and no molten injection material has been injected into the injection mold;

[0038] Figure 3 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the valve needle is in the open position of the nozzle and the injection mold is filled with molten injection material;

[0039] Figure 4 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the valve needle is in the closed position of the nozzle and the injection mold is filled with molten injection material;

[0040] Figure 5 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the valve needle is in a disengaged position, having disengaged from the injection molded article that has cooled and formed in the injection mold.

[0041] Figure 6 A schematic diagram of an injection molding machine spraying device according to an exemplary embodiment of the present invention is shown, wherein the injection mold is opened and the injection molded article is removed;

[0042] Figure 7 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the injection molding machine spraying device is in a vertical position to inject injection molding material in a vertical direction;

[0043] Figure 8 This diagram shows an injection molding machine spraying device according to an exemplary embodiment of the present invention, wherein the injection molding machine spraying device is in an inclined position to inject injection material in an inclined direction. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0045] Furthermore, in the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments disclosed herein. However, it will be apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and apparatuses are illustrated to simplify the figures.

[0046] According to a general technical concept of the present invention, an injection molding method is provided. The injection molding method includes: closing an injection mold and aligning the nozzle of an injection molding machine's sprue with the gate of the injection mold; moving a valve needle of the injection molding machine's sprue from a closed position (closing the nozzle's injection orifice) to an open position (opening the nozzle's injection orifice) to inject molten injection material into the cavity of the injection mold; after the cavity of the injection mold is filled with molten injection material, moving the valve needle from the open position to the closed position, such that the front end of the valve needle is inserted into the gate and slightly embedded in the injection-molded article; after the injection-molded article has cooled and solidified, moving the valve needle back from the closed position to a disengaged position (disengaged from the injection-molded article); and opening the injection mold and removing the injection-molded article from the injection mold.

[0047] According to another general technical concept of the present invention, an injection molding machine sprue device is provided. The injection molding machine sprue device includes: a nozzle having an end adapted to abut with a sprue of an injection mold and a spray hole formed in said end; a valve needle movably disposed in said nozzle for opening and closing said spray hole; and a drive device adapted to drive the valve needle to move between an open position (opening the spray hole) and a closed position (closing the spray hole). After the cavity of the injection mold is filled with molten injection material, the drive device drives the valve needle from the open position to the closed position, such that the front end of the valve needle is inserted into the sprue and slightly embedded in the injection-molded article; after the injection-molded article has cooled and solidified, the drive device drives the valve needle back from the closed position to a disengaged position (disengaged from the injection-molded article).

[0048] According to another general technical concept of the present invention, an injection molding method is provided. The injection molding method includes: providing the aforementioned injection molding machine spraying device; connecting the nozzle of the injection molding machine spraying device to the sprue of an injection mold; moving a first piston of a cylinder from a second position to a first position, causing a valve needle to move from a closed position to an open position, to inject molten injection material into the cavity of the injection mold; after the cavity of the injection mold is filled with molten injection material, moving the first piston from the first position to the second position, causing the valve needle to move from the open position to the closed position; after the injection-molded article has cooled and solidified, pushing the first piston to a third position by a second piston, causing the valve needle to move to a disengaged position detached from the injection-molded article; and opening the injection mold and removing the injection-molded article from the injection mold.

[0049] Figure 1 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the valve needle 3 is in the closed position of the nozzle 1 and the nozzle 1 is connected to the sprue 4a of the closed injection mold 4. Figure 2 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the valve needle 3 is in the open position of the nozzle 1 and no molten injection material has been injected into the injection mold 4. Figure 3 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the valve needle 3 is in the open position of the nozzle 1 and the injection mold 4 is filled with molten injection material. Figure 4 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the valve needle 3 is in the closed position of the nozzle 1 and the injection mold 4 is filled with molten injection material. Figure 5 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the valve needle 3 is in a disengaged position, having disengaged from the injection molded article 5 cooled and formed in the injection mold 4. Figure 6 A schematic diagram of an injection molding machine spraying device 100 according to an exemplary embodiment of the present invention is shown, wherein the injection mold 4 is opened and the injection molded article 5 is removed.

[0050] like Figures 1 to 6 As shown, in an exemplary embodiment of the present invention, an injection molding method is disclosed. The injection molding method includes the following steps:

[0051] S11: As Figure 1 As shown, the injection mold 4 is closed and the nozzle 1 of the injection molding machine spraying device 100 is connected to the pouring port 4a of the injection mold 4.

[0052] S12: As Figure 2and Figure 3 As shown, the valve needle 3 of the injection molding machine spraying device 100 is moved from the closed position of the spraying hole 11 of the nozzle 1 to the open position of the spraying hole 11 of the nozzle 1 to inject molten injection material into the cavity 40 of the injection mold 4.

[0053] S13: As Figure 4 As shown, after the cavity 40 of the injection mold 4 is filled with molten injection material, the valve needle 3 is moved from the open position to the closed position, so that the front end 3a of the valve needle 3 is inserted into the sprue 4a and slightly embedded in the injection molded product 5.

[0054] S14: As Figure 5 As shown, after the injection-molded part 5 has cooled and solidified, the valve pin 3 is moved back from the closed position to the disengagement position, so that the demolding of the injection-molded part 5 is not interfered with by the valve pin 3; and

[0055] S15: As Figure 6 As shown, the injection mold 4 is opened and the injection molded product 5 is removed from the injection mold 4.

[0056] In the aforementioned exemplary embodiments of the present invention, after the injection mold 4 is filled with molten injection material, the front end 3a of the valve needle 3 is inserted into the sprue 4a of the injection mold 4. The valve needle 3 is used to remove the molten injection material from the sprue 4a, thereby ensuring that the cooled and molded injection-molded product 5 has no protrusion corresponding to the sprue 4a. Therefore, the present invention eliminates the need to cut the protrusion caused by the sprue 4a, which not only improves injection molding efficiency but also improves the quality of the injection-molded product.

[0057] like Figures 1 to 6 As shown in the illustrated embodiment, in step S14, the movement distance of the valve needle 3 from the closed position to the disengaged position is slightly greater than the embedding depth of the front end 3a of the valve needle 3 into the injection molded product 5.

[0058] like Figures 1 to 6 As shown in the illustrated embodiment, the movement distance of the valve needle 3 from the closed position to the disengaged position is within the range of 0.1 mm to 1.0 mm.

[0059] like Figures 1 to 6 As shown in the illustrated embodiment, in step S13, the embedding depth of the front end 3a of the valve needle 3 into the injection molded product 5 is within the range of 0.05 mm to 0.2 mm.

[0060] like Figures 1 to 6 As shown in the illustrated embodiment, in step S14, when the valve needle 3 is moved to the disengaged position, the injection orifice 11 of the nozzle 1 is still in the closed state, which is closed by the valve needle 3.

[0061] like Figures 1 to 6 As shown, in another exemplary embodiment of the present invention, an injection molding machine spraying device is disclosed. This injection molding machine spraying device includes: a nozzle 1, a valve needle 3, and a drive device for moving the valve needle 3. The nozzle 1 has an end adapted to abut with a gating port 4a of an injection mold 4 and a spraying hole 11 formed in the end. The valve needle 3 is movably disposed in the nozzle 1 for opening and closing the spraying hole 11 of the nozzle 1. The drive device is adapted to drive the valve needle 3 between an open position (open spraying hole 11) and a closed position (closed spraying hole 11).

[0062] like Figures 1 to 6 As shown in the illustrated embodiment, after the cavity 40 of the injection mold 4 is filled with molten injection material, the drive device drives the valve needle 3 from the open position to the closed position, so that the front end 3a of the valve needle 3 is inserted into the sprue 4a and slightly embedded in the injection molded part 5. After the injection molded part 5 cools and solidifies, the drive device drives the valve needle 3 from the closed position back to the disengagement position, so that the demolding of the injection molded part 5 is not interfered with by the valve needle 3.

[0063] like Figures 1 to 6 As shown in the illustrated embodiment, the movement distance of the valve needle 3 from the closed position to the disengaged position is slightly greater than the embedding depth of the front end 3a of the valve needle 3 into the injection molded product 5.

[0064] like Figures 1 to 6 As shown in the illustrated embodiment, the movement distance of the valve needle 3 from the closed position to the disengaged position is within the range of 0.1 mm to 1.0 mm.

[0065] like Figures 1 to 6 As shown, in the illustrated embodiment, the embedding depth of the front end 3a of the valve needle 3 into the injection molded product 5 is within the range of 0.05 mm to 0.2 mm.

[0066] like Figures 1 to 6 As shown in the illustrated embodiment, when the valve needle 3 is moved to the disengaged position, the injection orifice 11 of the nozzle 1 is still in the closed state, which is closed by the valve needle 3.

[0067] like Figures 1 to 6 As shown, in the illustrated embodiment, the driving device includes a cylinder 2. The cylinder 2 includes a cylinder body 20 and a first piston member 21. The cylinder body 20 forms a first inner cavity 201. The first piston member 21 is movably disposed within the first inner cavity 201 and is capable of operating at a first position (…). Figure 2 and Figure 3 The position shown) and the second position ( Figure 1 and Figure 4The valve needle 3 moves between the positions shown. When the first piston 21 is moved from the first position to the second position, the valve needle 3 is moved from the open position to the closed position by the first piston 21.

[0068] like Figures 1 to 6 As shown in the illustrated embodiment, a second inner cavity 202, separated from the first inner cavity 201, is also formed in the cylinder body 20. The cylinder 2 further includes a second piston member 22, which is movably disposed within the second inner cavity 202. The second piston member 22 is used to push the first piston member 21 from... Figure 4 The second position shown is pushed to Figure 5 The third position is shown. When the first piston 21 is pushed from the second position to the third position by the second piston 22, the valve needle 3 is moved from the closed position to the disengaged position by the first piston 21.

[0069] like Figures 1 to 6 As shown in the illustrated embodiment, the first piston member 21 has a first piston rod 21a connected to the valve needle 3, and the second piston member 22 has a second piston rod 22a, which is movable between an extended position and a retracted position. When the second piston rod 22a moves from the retracted position to the extended position, the first piston member 21 is pushed from the second position to the third position by the second piston member 22. When the first piston member 21 is moved from the first position to the second position, the second piston rod 22a is pushed from the extended position to the retracted position by the first piston member 21.

[0070] like Figures 1 to 6 As shown in the illustrated embodiment, two first gas passages 2a communicating with the first inner cavity 201 and a second gas passage 2b communicating with the second inner cavity 202 are formed in the cylinder 20. The two first gas passages 2a and the second gas passage 2b are used to connect to a gas control circuit (not shown).

[0071] like Figures 1 to 6 As shown in the illustrated embodiment, the drive device further includes a gas control circuit. This gas control circuit is connected to two first gas passages 2a and one second gas passage 2b of the cylinder 2, and is used to control the movement of the first piston 21 and the second piston 22. Typically, this gas control circuit includes a gas source (not shown), a pipeline (not shown) connecting the gas source and the cylinder 2, a solenoid valve (not shown) mounted on the pipeline, and a controller (not shown) for controlling the solenoid valve. Note that the design of a gas control circuit that meets the requirements is not unique and can have many different variations.

[0072] although Figures 1 to 6 A specific exemplary embodiment of the driving device according to the present invention is shown; however, the driving device of the present invention is not limited to the illustrated embodiment.

[0073] Although not illustrated, in another exemplary embodiment of the invention, the drive device may include a linear electric cylinder and a controller for controlling the linear electric cylinder. The mover of the linear electric cylinder is connected to a valve needle 3, enabling the valve needle 3 to move linearly along with the mover. The controller controls the movement of the mover of the linear electric cylinder, allowing the valve needle 3 to be precisely moved to an open position, a closed position, and a disengaged position.

[0074] Although not illustrated, in another exemplary embodiment of the invention, the drive device may include a servo motor, a transmission mechanism connected between the servo motor and the valve needle 3, and a controller for controlling the servo motor. The transmission mechanism is used to convert the rotational motion of the servo motor into linear movement of the valve needle 3. The controller is used to control the rotation of the servo motor so that the valve needle 3 can be precisely moved to the open position, the closed position, and the disengaged position.

[0075] like Figures 1 to 6 As shown, in another exemplary embodiment of the present invention, an injection molding method is also disclosed. This injection molding method includes the following steps:

[0076] S21: Provide Figures 1 to 6 The injection molding machine spraying device 100 is shown.

[0077] S22: As Figure 1 As shown, the nozzle 1 of the injection molding machine spraying device 100 is connected to the sprue 4a of the injection mold 4.

[0078] S23: As Figure 2 and Figure 3 As shown, the first piston 21 of the cylinder 2 is moved from the second position to the first position, so that the valve needle 3 is moved from the closed position to the open position, so as to inject molten injection material into the cavity 40 of the injection mold 4.

[0079] S24: As Figure 4 As shown, after the cavity 40 of the injection mold 4 is filled with molten injection material, the first piston 21 is moved from the first position to the second position, so that the valve needle 3 moves from the open position to the closed position.

[0080] S25: As Figure 5 As shown, after the injection-molded product 5 has cooled and solidified, the first piston 21 is pushed to the third position by the second piston 22, causing the valve needle 3 to move to the disengagement position where it is separated from the injection-molded product 5; and

[0081] S26: As Figure 6 As shown, the injection mold 4 is opened and the injection molded product 5 is removed from the injection mold 4.

[0082] like Figure 6As shown in the illustrated embodiment, since the front end 3a of the valve needle 3 was slightly embedded into the injection molded product 5 before it cooled and solidified during the injection molding process, a shallow pit 5a will be formed on the surface of the injection molded product 5 after it has cooled and solidified. This shallow pit 5a will not affect the quality of the injection molded product 5.

[0083] like Figures 1 to 6 As shown in the illustrated embodiment, the injection molding machine's spraying device 100 is positioned horizontally, meaning the spray nozzle 11 of the nozzle 1 is horizontal, allowing for the injection of molding material into the injection mold 4 in a horizontal direction. However, the invention is not limited to this; the injection molding machine's spraying device 100 can also be positioned in any orientation within 360 degrees. For example, Figure 7 A schematic diagram of an injection molding machine spraying device 100 according to another exemplary embodiment of the present invention is shown, wherein the injection molding machine spraying device 100 is in a vertical orientation to inject injection molding material in a vertical direction. Figure 8 A schematic diagram of an injection molding machine spraying device 100 according to another exemplary embodiment of the present invention is shown, wherein the injection molding machine spraying device 100 is in an inclined position to inject injection molding material in an inclined direction.

[0084] Those skilled in the art will understand that the embodiments described above are exemplary and can be improved upon. The structures described in the various embodiments can be freely combined without causing structural or principle conflicts, and these changes should fall within the protection scope of this invention.

[0085] Although the invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to illustrate preferred embodiments of the invention and should not be construed as limiting the invention.

[0086] While some embodiments of the general concept of the invention have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept of the invention, the scope of which is defined by the claims and their equivalents.

[0087] It should be noted that the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude multiple elements. Furthermore, any reference numerals in the claims should not be construed as limiting the scope of the invention.

Claims

1. A method of injection molding, characterized in that, comprising the steps of: S11: closing an injection mold (4) and abutting a nozzle (1) of a sprue device (100) of an injection molding machine to a sprue gate (4a) of the injection mold (4); S12: moving a valve needle (3) of the sprue device (100) from a closed position closing a jet hole (11) of the nozzle (1) to an open position opening the jet hole (11) of the nozzle (1) to inject molten injection material into a cavity (40) of the injection mold (4); S13: after the cavity (40) of the injection mold (4) is filled with the molten injection material, moving the valve needle (3) from the open position to the closed position so that a front end (3a) of the valve needle (3) is inserted into the sprue gate (4a) and slightly embedded into an injection molded article (5); S14: after the injection molded article (5) is cooled and molded, moving the valve needle (3) from the closed position back to a disengagement position disengaging from the injection molded article (5); and S15: opening the injection mold (4) and taking out the injection molded article (5) from the injection mold (4).

2. The injection molding method according to claim 1, wherein: in the step S14, a moving distance of the valve needle (3) from the closed position back to the disengagement position is slightly larger than an embedding depth of the front end (3a) of the valve needle (3) embedded into the injection molded article (5).

3. The injection molding method according to claim 2, wherein: the moving distance of the valve needle (3) from the closed position back to the disengagement position is within a range of 0.1 mm to 1.0 mm.

4. The injection molding method according to claim 2, wherein: in the step S13, the embedding depth of the front end (3a) of the valve needle (3) embedded into the injection molded article (5) is within a range of 0.05 mm to 0.2 mm.

5. The injection molding method according to claim 1, wherein: in the step S14, when the valve needle (3) is moved to the disengagement position, the jet hole (11) of the nozzle (1) is still in a closed state closed by the valve needle (3).

6. An injection molding machine dispensing apparatus characterized by, comprising: a nozzle (1) having an end portion adapted to be abutted to a sprue gate (4a) of an injection mold (4) and a jet hole (11) formed in the end portion; a valve needle (3) movably provided in the nozzle (1) for opening and closing the jet hole (11); and a driving device adapted to drive the valve needle (3) to move between an open position opening the jet hole (11) and a closed position closing the jet hole (11), after the cavity (40) of the injection mold (4) is filled with the molten injection material, the driving device drives the valve needle (3) to move from the open position to the closed position so that a front end (3a) of the valve needle (3) is inserted into the sprue gate (4a) and slightly embedded into an injection molded article (5) molded, After the injection-molded product (5) is cooled and formed, the drive device drives the valve needle (3) to move from the closed position back to a disengaged position disengaged from the injection-molded product (5).

7. The injection-molding machine sprue device according to claim 6, characterized in that: The moving distance of the valve needle (3) from the closed position back to the disengaged position is slightly greater than the embedding depth of the front end portion (3a) of the valve needle (3) embedded into the injection-molded product (5).

8. The injection-molding machine sprue device according to claim 6, characterized in that: The moving distance of the valve needle (3) from the closed position back to the disengaged position is within the range of 0.1 mm to 1.0 mm.

9. The injection-molding machine sprue device according to claim 6, characterized in that: The embedding depth of the front end portion (3a) of the valve needle (3) embedded into the injection-molded product (5) is within the range of 0.05 mm to 0.2 mm.

10. The injection-molding machine sprue device according to claim 6, characterized in that: When the valve needle (3) is moved to the disengaged position, the injection hole (11) of the nozzle (1) is still in the closed state closed by the valve needle (3).

11. The injection-molding machine sprue device according to claim 6, characterized in that: The drive device comprises a linear motor and a controller for controlling the linear motor, a mover of the linear motor is connected with the valve needle (3) so that the valve needle (3) can move linearly together with the mover.

12. The injection-molding machine sprue device according to claim 6, characterized in that: The drive device comprises a servo motor, a transmission mechanism connected between the servo motor and the valve needle (3) and a controller for controlling the servo motor, the transmission mechanism is used for converting the rotary motion of the servo motor into the linear motion of the valve needle (3).

13. The injection-molding machine sprue device according to claim 6, characterized in that: The drive device comprises a pneumatic cylinder (2), The pneumatic cylinder (2) comprises: a cylinder body (20) formed with a first inner cavity (201); and a first piston member (21) movably arranged in the first inner cavity (201) and capable of moving between a first position and a second position, When the first piston member (21) is moved from the first position to the second position, the valve needle (3) is moved from the open position to the closed position by the first piston member (21).

14. The injection-molding machine sprue device according to claim 13, characterized in that: A second inner cavity (202) is further formed in the cylinder body (20) and is isolated from the first inner cavity (201); The pneumatic cylinder (2) further comprises: a second piston member (22) movably arranged in the second inner cavity (202), the second piston member (22) is used for pushing the first piston member (21) from the second position to a third position, When the first piston member (21) is pushed from the second position to the third position by the second piston member (22), the valve needle (3) is moved from the closed position to the disengaged position by the first piston member (21).

15. The injection molding machine sprue device according to claim 14, characterized in that: the first piston member (21) has a first piston rod (21a) connected with the valve needle (3), and the second piston member (22) has a second piston rod (22a) capable of moving between an extended position and a retracted position; when the second piston rod (22a) moves from the retracted position to the extended position, the first piston member (21) is pushed from the second position to the third position by the second piston member (22); when the first piston member (21) is moved from the first position to the second position, the second piston rod (22a) is pushed from the extended position to the retracted position by the first piston member (21).

16. The injection molding machine sprue device according to claim 15, characterized in that: two first gas passages (2a) in communication with the first inner cavity (201) and one second gas passage (2b) in communication with the second inner cavity (202) are formed in the cylinder (20), and the two first gas passages (2a) and the one second gas passage (2b) are used to be connected with a gas control circuit.

17. The injection molding machine sprue device according to claim 16, characterized in that: the driving device further comprises: a gas control circuit connected with the two first gas passages (2a) and the one second gas passage (2b) of the cylinder (2) for controlling the movement of the first piston member (21) and the second piston member (22).

18. The injection molding machine sprue device according to claim 17, characterized in that: the gas control circuit comprises: a gas source; a pipeline connected between the gas source and the cylinder (2); a solenoid valve arranged on the pipeline; and a controller for controlling the solenoid valve.

19. A method of injection molding, characterized by, comprising the following steps: S21: providing the injection molding machine sprue device (100) according to claim 14; S22: abutting the nozzle (1) of the injection molding machine sprue device (100) with the gate (4a) of the injection mold (4); S23: moving the first piston member (21) of the cylinder (2) from the second position to the first position, so that the valve needle (3) is moved from the closed position to the open position to inject the molten injection material into the cavity (40) of the injection mold (4); S24: after the cavity (40) of the injection mold (4) is filled with the molten injection material, moving the first piston member (21) from the first position to the second position, so that the valve needle (3) is moved from the open position to the closed position; S25: After the injection molded product (5) has cooled and formed, the first piston (21) is pushed to the third position by the second piston (22), so that the valve needle (3) is moved to the disengagement position that is disengaged from the injection molded product (5); and S26: Open the injection mold (4) and remove the injection molded product (5) from the injection mold (4).

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