Automatic injection molding flow adjusting mechanism for liquid silica gel injection molding system

Abstract

The utility model relates to the technical field of injection molding systems, in particular to an automatic injection molding flow adjusting mechanism for a liquid silica gel injection molding system. The cold runner system comprises a cold runner system mold, a plurality of pouring runner systems arranged on the cold runner system mold, and cold runner nozzle air cylinder assemblies which are arranged in a one-to-one mode and used for being matched with the pouring runner systems. The valve needle assembly is driven by the cold runner nozzle air cylinder assembly; and the adjusting mechanism is arranged in the cold runner system mold and independently controls the cold runner nozzle air cylinder assembly. The cold runner nozzle air cylinder assembly has the advantages that according to the technical scheme, the adjusting mechanisms capable of being independently controlled are independently arranged on the cold runner nozzle air cylinder assembly, the stroke distance of the cold runner nozzle air cylinder assembly is controlled through the adjusting assemblies, and therefore the purpose of reducing the glue outlet flow is achieved.

Description

Technical Field

[0001] This utility model relates to the field of injection molding system technology, and in particular to an automatic flow rate adjustment mechanism for liquid silicone injection molding systems. Background Technology

[0002] Silicone is widely used in the market because it does not release toxic substances, has a soft and comfortable feel, can withstand high and low temperatures (-60°C to +300°C), and possesses excellent physical and chemical properties. It is a strong elastomer with superior sealing properties compared to rubber, excellent electrical insulation, and resistance to chemicals, fuels, oils, and water, making it a good material for handling harsh environments. Industrial applications include oil seals, keyboard keys, electrical insulation materials, and automotive parts. Consumer products include pacifiers, artificial cannulas, respirators, goggles, shoe insoles, food containers, etc. Silicone can be divided into solid and liquid forms. The former is processed by thermoforming, while the latter is mainly injection molding. Although liquid silicone has higher equipment investment and raw material costs, its faster production speed, lower processing degree, and less waste make injection molding of liquid silicone a future trend in the precision, speed, and automation-oriented injection molding industry.

[0003] In existing technologies, liquid silicone is divided into A-component and B-component, which are controlled to a 1:1 ratio using a metering device. They are then thoroughly mixed using a static mixer before being injected into the injection tube for injection molding. Injecting liquid silicone into a cold runner system mold to produce silicone products offers advantages such as one-step molding, zero waste, and automation. However, liquid silicone has a low viscosity, allowing for faster filling speeds even at lower injection pressures during injection molding. Because of its excellent fluidity, it is difficult to ensure balanced ejection in each cavity during multi-cavity molding, leading to quality problems such as burrs, inconsistent weight, and dimensional inaccuracies.

[0004] Therefore, it is necessary to design an automatic flow adjustment mechanism for liquid silicone injection molding systems to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide an automatic flow adjustment mechanism for liquid silicone injection molding systems, so as to overcome the above-mentioned shortcomings of the existing technology.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An automatic flow rate adjustment mechanism for a liquid silicone injection molding system includes a gating system, a cold runner nozzle cylinder assembly for cooperating with the gating system, a valve needle assembly driven by the cold runner nozzle cylinder assembly, and an adjustment mechanism placed in the gating system and independently controlling the cold runner nozzle cylinder assembly. The adjustment assembly includes an adjustment rod that can move up and down and supports the valve needle assembly, a slider for driving the adjustment rod to move, and a stepper motor for driving the slider to move. The stepper motor has a connecting block at its driving end, and the slider has a slot at one end connected to the stepper motor, with the connecting block of the stepper motor embedded in the slot of the slider.

[0008] Preferably, a groove is provided between the upper fixed seat and the lower fixed seat for the slider to move, and the upper fixed seat and the lower fixed seat are fixed together by a fastener.

[0009] Preferably, the contact surface between the connecting block and the slot is an arc-shaped structure.

[0010] Preferably, the side of the slider that contacts the adjusting rod is set as an inclined plane.

[0011] Preferably, a limiting groove is formed on the upper surface of the slider, and a limiting pin is installed in the upper fixed seat; part of the positioning pin is placed in the limiting groove of the slider.

[0012] The beneficial effects of this utility model are as follows: This technical solution sets up an adjustable mechanism that can be controlled independently for each cold runner nozzle cylinder assembly. By adjusting the stroke distance of the cold runner nozzle cylinder assembly, the dispensing flow rate is reduced, thereby solving the problem of unbalanced dispensing in the cold runner system, reducing the product defect rate, and solving a series of problems caused by unbalanced dispensing in the cold runner system. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an automatic injection flow adjustment mechanism for a liquid silicone injection molding system according to the present invention;

[0014] Figure 2 This is a cross-sectional view of an automatic injection flow adjustment mechanism for a liquid silicone injection molding system according to the present invention.

[0015] Figure 3 This is a structural layout diagram of the cold runner nozzle cylinder assembly, valve needle assembly, and adjustment mechanism for an automatic injection flow adjustment mechanism in a liquid silicone injection molding system according to the present invention.

[0016] Figure 4This is a connection structure diagram of a stepper motor and a slider bracket for an automatic injection flow adjustment mechanism in a liquid silicone injection molding system according to the present invention.

[0017] In the diagram: 1. Cold runner system mold; 3. Cold runner nozzle cylinder assembly; 4. Valve needle assembly; 5. Adjustment mechanism; 51. Lower fixed seat; 52. Upper fixed seat; 53. Adjusting rod; 54. Slider; 55. Stepper motor; 56. Groove; 551. Connecting block; 541. Slot; 542. Limiting groove; 521. Limiting pin; 31. Piston. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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 on this utility model.

[0020] Reference Figures 1 to 4 An automatic flow rate adjustment mechanism for a liquid silicone injection molding system includes a cold runner system mold 1, a plurality of gating runner systems placed in the cold runner system mold, a cold runner nozzle cylinder assembly 3 configured one-to-one to cooperate with the gating runner systems, a valve needle assembly 4 driven by the cold runner nozzle cylinder assembly, and an adjustment mechanism 5 placed in the cold runner system mold and independently controlling the cold runner nozzle cylinder assembly.

[0021] The adjustment mechanism is set separately for a set of cold runner nozzle cylinder assemblies. The adjustment assembly 5 includes a lower fixed seat 51 placed on the cold runner nozzle cylinder assembly, an upper fixed seat 52 placed on the upper fixed seat, an adjustment rod 53 that passes through the lower fixed seat and can move up and down to support the cylinder piston of the cold runner nozzle cylinder assembly, a slider 54 placed between the lower fixed seat and the upper fixed seat and used to drive the adjustment rod to move, and a stepper motor 55 that drives the slider to move.

[0022] A groove 56 is provided between the upper fixed seat and the lower fixed seat to allow the slider to move; and the upper fixed seat and the lower fixed seat are fixed together by a fastener; the groove 56 is for the slider to be installed.

[0023] The stepper motor 55 is provided with a connecting block 551 at its drive end. The slider 54 is connected to the stepper motor at one end and has a slot 541. The connecting block 551 of the stepper motor 55 is embedded in the slot 541 of the slider. The connecting block 551 and the slot 541 can be T-shaped structures. The connecting block 551 is inserted into the slot 541, and the two are interlocked. The contact end face of the connecting block 551 and the slot 541 is an arc-shaped structure. When the stepper motor is driven to extend or retract, there is a certain gap between the connecting block 551 and the slot 541. Since the end is arc-shaped, when there is a deviation in the horizontality or verticality, it will cause jamming with the slider. The contact end face will be subjected to force to adjust, thereby avoiding the problem of the slider movement getting stuck due to the swaying of the connecting rod. The slot-type connection method makes it easy to install the stepper motor's 55 lead screw and slider, ensuring accurate positioning. Simultaneously, the special design of the electric motor connecting rod head reduces the precision requirements for both motor mechanism and mold machining, avoiding motor seizure issues caused by positioning errors in the motor spindle and valve needle connection mechanism. The valve needle stroke drive mechanism has a stop design for motor zeroing, ensuring high repeatability of motor motion data.

[0024] In order to effectively control the vertical movement distance of the adjusting rod, the side of the slider that contacts the adjusting rod is set with an inclined surface. The smaller the inclined surface of the slider and the adjusting rod, the more the adjusting rod moves downward, resulting in a decrease in the piston stroke. Similarly, the larger the inclined surface, the more the adjusting rod moves up and down, and the more the piston stroke increases, thereby achieving secondary control of the valve needle.

[0025] In order to limit the movement of the slider 54, a limiting groove 542 is formed on the upper surface of the slider, and a limiting pin 521 is installed in the upper fixed seat 52; part of the positioning pin 521 is placed in the groove of the limiting groove 542 of the slider. When the slider moves to the end and is blocked by the limiting pin 521, it will be blocked when it moves to the other end, thereby limiting the stroke of the slider.

[0026] To facilitate use with the slider 54, the surfaces that contact each other on one side of the inclined surface of the adjusting rod and the slider 54 are complementary surfaces, ensuring that the surfaces can contact each other when the adjusting rod and the slider are adjusted, thus ensuring the accuracy and efficiency of the movement and preventing jamming.

[0027] refer to Figure 3In this implementation, when the stepper motor returns to its limit and the slider limits the load, it automatically returns to zero. At this point, the cold runner nozzle cylinder has its maximum stroke and is positioned at the rightmost end. When the stepper motor moves to the left, the slider pushes the adjusting rod downward, thereby changing the stroke of the cold runner nozzle cylinder assembly. This causes the piston 31 of the cold runner nozzle cylinder assembly to change. The piston can move up and down under pneumatic action. The stroke distance of the piston is determined by the position of the adjusting rod. When the slider moves to the left, the adjusting rod moves downward, and the piston stroke decreases. When the slider moves to the right, the adjusting rod moves upward, and the stroke increases, thereby reducing the glue flow rate.

[0028] The advantages of this utility model are that this technical solution sets up an independent adjustable mechanism for each cold runner nozzle cylinder assembly, and controls the stroke distance of the cold runner nozzle cylinder assembly through the adjustable component, thereby reducing the glue flow rate, solving the problem of glue inlet imbalance in the cold runner system, reducing the product defect rate, and solving a series of problems caused by glue inlet imbalance in the cold runner system.

[0029] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An automatic flow rate adjustment mechanism for a liquid silicone injection molding system, comprising a gating system, a cold runner nozzle cylinder assembly configured to cooperate with the gating system, a valve needle assembly driven by the cold runner nozzle cylinder assembly, and an adjustment mechanism disposed in the gating system and independently controlling the cold runner nozzle cylinder assembly, the adjustment mechanism comprising an adjusting rod movable up and down and supporting the valve needle assembly, a slider for driving the adjusting rod to move, and a stepper motor for driving the slider to move, characterized in that: The stepper motor has a connecting block at its drive end. The slider has a slot at the end where it is connected to the stepper motor. The connecting block of the stepper motor is embedded in the slot of the slider. The contact surface between the connecting block and the slot is an arc-shaped structure.

2. The automatic injection flow adjustment mechanism for a liquid silicone injection molding system according to claim 1, characterized in that: The adjustment mechanism further includes a lower fixed seat placed on the cold flow channel nozzle cylinder assembly and an upper fixed seat disposed on the lower fixed seat. A groove for the slider to move is provided between the upper fixed seat and the lower fixed seat, and the upper fixed seat and the lower fixed seat are fixed together by a fastener.

3. The automatic flow rate adjustment mechanism for a liquid silicone injection molding system according to claim 2, characterized in that: The side of the slider that contacts the adjusting rod is set at an inclined plane.

4. The automatic injection flow adjustment mechanism for a liquid silicone injection molding system according to claim 3, characterized in that: A limiting groove is formed on the upper surface of the slider, and a limiting pin is installed in the upper fixed seat; part of the limiting pin is placed in the limiting groove of the slider.

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