Needle valve type hot runner injection mold for producing plastic tableware

Abstract

The utility model provides a needle valve type hot runner injection mold for producing plastic tableware, and belongs to the technical field of injection molds. The injection mold comprises a movable mold plate, a fixed mold plate, needle valve assemblies, a front mold base, a rear mold base, a female mold and a male mold, the fixed mold plate, the front mold base and the female mold are sequentially fixed through bolts, the movable mold plate, the rear mold base and the male mold are sequentially fixed through bolts, sprues of the three needle valve assemblies are communicated with respective mold cavities, and a hot flow pipeline is fixed to the movable mold plate. The hot flow pipeline is provided with an injection port and three outlets, the outlets of the hot flow pipeline are connected with side connectors of the valve needle sleeve, a driving air cylinder is further fixed to the movable mold plate, a synchronous plate sliding front and back is arranged in the rear mold base, the rear ends of the valve needles are connected with synchronous rods, the three synchronous rods are all fixed to the same synchronous plate, and a telescopic rod of the driving air cylinder is connected to the synchronous plate. And the needle valve assemblies are uniformly controlled by one driving air cylinder, so that the mold cavities are synchronously and completely filled, and a plurality of high-quality plastic tableware can be simultaneously formed.

Description

Technical Field

[0001] The utility model belongs to the technical field of injection molds and relates to a needle valve type hot runner injection mold for producing plastic tableware. Background Art

[0002] Needle valve injection mold refers to a mold that uses the opening and closing action of a needle valve to control the opening and closing of the mold gate during injection molding. This injection molding method is suitable for molding multiple parts at a time, so needle valve hot runner injection molds are widely used. There are many mold cavities, and the glue injection of each cavity must be balanced, so the glue injection and the action of the valve needle must be synchronized, and multiple valve needles must be opened and closed at the same time, so as to ensure that the products of each cavity of the injection molding are synchronously filled and complete, the product pressure is balanced, and the quality standards are consistent. In the existing technology, each valve needle is controlled by a cylinder or an oil cylinder, so the above parameters are difficult to guarantee. Utility Model Content

[0003] The purpose of the utility model is to address the above-mentioned problems in the existing technology and to propose a needle valve type hot runner injection mold for producing plastic tableware. The needle valve assembly is uniformly controlled by a driving cylinder so that each mold cavity can be filled completely and synchronously, and multiple high-quality plastic tableware can be molded at the same time.

[0004] The purpose of the utility model can be achieved through the following technical solutions: a needle valve hot runner injection mold for producing plastic tableware, comprising a movable mold plate, a fixed mold plate, a needle valve assembly, a front mold seat, a rear mold seat, a concave mold and a convex mold, characterized in that the needle valve assembly comprises a valve needle and a valve needle sleeve, the front end of the valve needle sleeve has a gate, the valve needle is slidably arranged in the valve needle sleeve and can block the gate, the fixed mold plate, the front mold seat and the concave mold are fixed by bolts in sequence, the movable mold plate, the rear mold seat and the convex mold are fixed by bolts in sequence, the concave mold has three gradually increasing steps protruding from bottom to top, each increasing step has a bowl-shaped concave cavity, and the convex mold is provided with three corresponding to the concave mold from bottom to top. The decreasing step is gradually recessed on the upper surface, the increasing step is fitted with the decreasing step, the decreasing step has a convex arc-shaped protrusion, the arc-shaped protrusion cooperates with the concave cavity to form a mold cavity, the punch is provided with a mounting hole for fixing the needle valve assembly, the gates of the three groups of needle valve assemblies are connected with their respective mold cavities, a heat flow pipe is fixed on the movable mold plate, the heat flow pipe has an injection port and three outlets, the outlet of the heat flow pipe is connected with the side interface of the valve needle sleeve, a driving cylinder is also fixed on the movable mold plate, a synchronous plate that slides back and forth is provided in the rear mold base, a synchronous rod is connected to the rear end of the valve needle, the three synchronous rods are all fixed on the same synchronous plate, and the telescopic rod of the driving cylinder is connected to the synchronous plate.

[0005] Furthermore, a guide rod is fixed on the front die base, and guide holes for the guide rod to pass through are opened on the concave die and the convex die.

[0006] Furthermore, a material return cavity is opened in the front mold base, a material return plate is provided in the material return cavity, a material return rod is passed through the incremental step, the front end of the material return rod extends into the mold cavity, the rear end of the material return rod is fixed on the material return plate, and a push rod is passed through the fixed mold plate, the front end of which is connected to the material return plate.

[0007] Furthermore, the gates of the three needle valve assemblies are all connected to the uppermost end of the mold cavity.

[0008] Furthermore, a guide slide column is fixed on the fixed template, and the guide slide column passes through the stripping plate.

[0009] The screw extruder fills the molten plastic from the injection port, and the plastic enters the valve needle sleeve of each needle valve assembly along the hot flow pipe. The drive cylinder is started to pull the valve needle backward, thereby opening the gate at the front end of the valve needle sleeve, and the plastic enters the mold cavity. After being filled, it is cooled and shaped, and the movable mold plate moves backward. The unloading cylinder drives the ejector rod to move forward, driving the ejector plate and ejector rod forward, so that the ejector rod pushes the tableware product out of the cavity to complete the unloading.

[0010] Compared with the prior art, the needle valve hot runner injection mold for producing plastic tableware has the following advantages:

[0011] 1. The stepped punch and die can be closed accurately and quickly, and the tableware products are staggered front and back during unloading without affecting each other.

[0012] 2. The needle valve assembly is uniformly controlled by a driving cylinder, so that each mold cavity can be filled completely synchronously, and multiple high-quality plastic tableware can be molded at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of a needle valve hot runner injection mold for producing plastic tableware.

[0014] Figure 2 is a cross-sectional view of the needle valve assembly.

[0015] In the figure, 1. movable mold plate; 2. fixed mold plate; 3. needle valve assembly; 31. valve needle; 32. valve needle sleeve; 33. gate; 34. side interface; 4. front mold base; 5. rear mold base; 6. die; 7. punch; 8. mold cavity; 9. heat flow pipe; 10. driving cylinder; 11. synchronization plate; 12. synchronization rod; 13. guide rod; 14. material withdrawal cavity; 15. material withdrawal plate; 16. material withdrawal rod; 17. ejector rod; 18. guide slide column. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0017] like Figure 1As shown, the needle valve hot runner injection mold for producing plastic tableware includes a movable mold plate 1, a fixed mold plate 2, a needle valve assembly 3, a front mold base 4, a rear mold base 5, a concave mold 6 and a punch 7. The fixed mold plate 2, the front mold base 4 and the concave mold 6 are fixed in sequence by bolts, and the movable mold plate 1, the rear mold base 5 and the punch 7 are fixed in sequence by bolts.

[0018] like Figure 2 As shown, the needle valve assembly 3 includes a valve needle 31 and a valve needle sleeve 32. The front end of the valve needle sleeve 32 has a gate 33. The valve needle 31 is slidably arranged in the valve needle sleeve 32 and can block the gate 33. The female mold 6 has three gradually increasing steps protruding from bottom to top, each of which has a bowl-shaped cavity. The male mold 7 has three gradually decreasing steps concave from bottom to top corresponding to the female mold 6. The increasing steps fit the decreasing steps. The decreasing steps have a protruding arc-shaped protrusion. The arc-shaped protrusion cooperates with the cavity to form a mold cavity 8. The male mold 7 has a mounting hole for fixing the needle valve assembly 3. The gates 33 of the three groups of needle valve assemblies 3 are connected to their respective mold cavities 8. The gates 33 of the three groups of needle valve assemblies 3 in this embodiment are all connected to the uppermost end of the mold cavity 8. A heat flow pipe 9 is fixed on the movable template 1. The heat flow pipe 9 has an injection port and three outlets. The outlet of the heat flow pipe 9 is connected to the side interface 34 of the valve needle sleeve 32. A driving cylinder 10 is also fixed on the movable template 1. A synchronous plate 11 that slides back and forth is provided in the rear mold base 5. A synchronous rod 12 is connected to the rear end of the valve needle 31. The three synchronous rods 12 are all fixed on the same synchronous plate 11. The telescopic rod of the driving cylinder 10 is connected to the synchronous plate 11.

[0019] A guide rod 13 is fixed on the front die base 4, and a guide hole for the guide rod 13 to pass through is opened on the concave die 6 and the convex die 7. The guide rod 13 is provided so that the concave die 6 and the convex die 7 can be closed more quickly and accurately.

[0020] A material stripping cavity 14 is formed in the front die base 4, a material stripping plate 15 is provided in the material stripping cavity 14, a material stripping rod 16 is passed through the incremental step, the front end of the material stripping rod 16 extends into the die cavity 8, the rear end of the material stripping rod 16 is fixed to the material stripping plate 15, a push rod 17 with a front end connected to the material stripping plate 15 is passed through the fixed die plate 2, a guide slide column 18 is fixed on the fixed die plate 2, and the guide slide column 18 passes through the material stripping plate 15.

[0021] Injection molding process: The screw extruder fills the molten plastic from the injection port, and the plastic enters the valve needle sleeve 32 of each needle valve assembly 3 along the hot flow pipe 9, and the driving cylinder 10 is started to pull the valve needle 31 backward, thereby opening the gate 33 at the front end of the valve needle sleeve 32, and the plastic enters the mold cavity 8. After being filled and cooled and shaped, the movable mold plate 1 moves backward, and the unloading cylinder drives the ejector 17 to move forward, driving the stripper plate 15 and the stripper rod 16 forward, so that the stripper rod 16 pushes the tableware product out of the cavity to complete the unloading.

[0022] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A needle valve hot runner injection mold for producing plastic tableware, comprising a movable mold plate, a fixed mold plate, a needle valve assembly, a front mold base, a rear mold base, a concave mold and a convex mold, characterized in that: The needle valve assembly includes a valve needle and a valve needle sleeve. The front end of the valve needle sleeve has a gate. The valve needle is slidably arranged in the valve needle sleeve and can block the gate. The fixed template, the front mold seat and the female mold are fixed by bolts in sequence. The movable template, the rear mold seat and the male mold are fixed by bolts in sequence. The female mold has three increasing steps that gradually protrude from bottom to top, and each increasing step has a bowl-shaped cavity. The male mold is provided with three decreasing steps that gradually concave from bottom to top corresponding to the female mold. The increasing steps fit the decreasing steps, and the decreasing steps have convex arc-shaped protrusions. The arc-shaped protrusion cooperates with the concave cavity to form a mold cavity. The punch is provided with a mounting hole for fixing the needle valve assembly. The gates of the three sets of needle valve assemblies are connected with their respective mold cavities. A heat flow pipe is fixed on the movable mold plate. The heat flow pipe has an injection port and three outlets. The outlet of the heat flow pipe is connected to the side interface of the valve needle sleeve. A driving cylinder is also fixed on the movable mold plate. A synchronous plate that slides back and forth is provided in the rear mold base. A synchronous rod is connected to the rear end of the valve needle. The three synchronous rods are all fixed on the same synchronous plate, and the telescopic rod of the driving cylinder is connected to the synchronous plate.

2. A needle valve hot runner injection mold for producing plastic tableware according to claim 1, characterized in that: A guide rod is fixed on the front die seat, and guide holes for the guide rod to pass through are opened on the concave die and the convex die.

3. A needle valve hot runner injection mold for producing plastic tableware according to claim 2, characterized in that: A material stripping cavity is provided in the front die base, a material stripping plate is provided in the material stripping cavity, a material stripping rod is passed through the incremental step, the front end of the material stripping rod extends into the die cavity, the rear end of the material stripping rod is fixed on the material stripping plate, and a push rod is passed through the fixed die plate, the front end of which is connected to the material stripping plate.

4. A needle valve hot runner injection mold for producing plastic tableware according to claim 3, characterized in that: The gates of the three needle valve assemblies are all connected to the uppermost end of the mold cavity.

5. The needle valve hot runner injection mold for producing plastic tableware according to claim 3, characterized in that: A guide slide column is fixed on the fixed template, and the guide slide column passes through the stripping plate.

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