Liquid silica gel injection mold convenient for gel amount control

Abstract

The invention relates to the technical field of injection molds, and discloses a liquid silica gel injection mold convenient for glue amount control, the liquid silica gel injection mold comprises an upper mold plate, a lower mold plate and a temperature control box, a splitter plate is arranged between the upper mold plate and the lower mold plate, the upper mold plate is provided with a glue injection port, and the glue injection port is connected with a plurality of liquid silica gel cold nozzles through the splitter plate; a main runner communicated with the glue injection port and a plurality of sub-runners communicated with the main runner are arranged in the splitter plate, the sub-runners are arranged below the main runner in a communicating manner, the sub-runners comprise a first sub-runner and a second sub-runner which are symmetrically arranged, and each of the first sub-runner and the second sub-runner comprises a first arc-shaped section, a second arc-shaped section and a converging section; the liquid silica gel cold nozzle comprises a valve needle driving assembly, a valve needle connected to the output end of the valve needle driving assembly and a cold nozzle body, the cold nozzle body is integrally connected to the lower portion of the valve needle driving assembly, one end of a piston piece of the valve needle driving assembly extends out of the upper die plate to be connected with an adjusting piece, and the other end of the piston piece extends into a cold nozzle runner to be connected with the valve needle to form an adjustable needle valve structure.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molds, and particularly to a liquid silicone injection mold facilitating glue volume control. Background Art

[0002] An injection mold is a tool for producing plastic products and also a tool for endowing plastic products with a complete structure and precise dimensions. Injection molding is a processing method used when mass-producing some parts with complex shapes. Specifically, it means injecting the heat-melted plastic into the mold cavity under high pressure by an injection molding machine, and after cooling and solidifying, a formed product is obtained. Liquid silicone, also known as liquid silicone rubber, is relative to solid high-temperature vulcanized silicone rubber. It is a liquid glue with the characteristics of good fluidity, fast vulcanization, and being safer and more environmentally friendly, and can fully meet the requirements of food grade. Liquid silicone has excellent tear resistance, resilience, anti-yellowing property, thermal stability, heat resistance and anti-aging property, etc. During the production process of liquid silicone products, a cold runner system needs to be set on the mold to accelerate the cooling and forming of the products.

[0003] Among various existing runner systems, the commonly used and runner system that can ensure the quality of the formed product is the valve pin hot runner system. A valve pin is provided on the valve pin runner system. The valve pin can move upward or downward in the vertical direction to open or close. When the finished product is demolded, the valve pin moves downward to close the hot nozzle. The stroke of the valve pin of the existing valve pin runner system is fixed, and the injection time is long, resulting in low injection efficiency. The glue inlet of the existing injection cold nozzle mainly adopts one-way glue inlet, and the injection precision is low. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a liquid silicone injection mold facilitating glue volume control to improve the injection precision.

[0005] The technical solution of the present invention is as follows: A liquid silicone injection mold facilitating glue volume control, comprising an upper template, a lower template and a temperature control box. A manifold plate is arranged between the upper template and the lower template. An injection port is arranged on the upper template. The injection port is connected with a plurality of liquid silicone nozzles through the manifold plate. A main runner communicated with the injection port and a plurality of sub-runners communicated with the main runner are arranged inside the manifold plate. The sub-runners are arranged below the main runner in a communicating manner. The sub-runners include a first sub-runner and a second sub-runner arranged symmetrically. Both the first sub-runner and the second sub-runner include a first arc segment, a second arc segment and a confluence segment. The radian of the first arc segment is smaller than that of the second arc segment. The liquid silicone nozzle includes a valve needle driving assembly, a valve needle connected to the output end of the valve needle driving assembly and a nozzle. First nozzle glue inlets and second nozzle glue inlets communicated with the nozzle runner are symmetrically arranged on both sides of the nozzle. The outlet end of the confluence segment of the first sub-runner is communicated with the first nozzle glue inlet. The outlet end of the confluence segment of the second sub-runner is communicated with the second nozzle glue inlet. The nozzle is integrally connected below the valve needle driving assembly. One end of the piston part of the valve needle driving assembly extends out of the upper template and is connected with an adjusting part, and the other end extends into the nozzle runner and is connected with the valve needle to form an adjustable needle valve structure.

[0006] As can be seen from the above solution, the injection port is used for injecting glue into the mold. The manifold plate realizes double-layer flow splitting through the main runner and the sub-runners, facilitating the injection molding of products. The manifold plate is used for flow splitting to realize the simultaneous injection molding of multiple products. The first arc segment is used to accelerate the flow rate after flow splitting. The confluence segment is used to realize injection molding after two-way glue inlet. The second arc segment is used for the connection between the first arc segment and the confluence segment. After the liquid silicone flows through the first sub-runner and the second sub-runner respectively from the main runner, it enters the nozzle runner from both sides of the valve needle at the same time. In this invention, through the combination of double-layer runners and two-way glue inlet, the glue inlet inside the liquid silicone nozzle is uniform, avoiding problems such as the valve needle being deflected by the glue liquid, resulting in a decrease in the glue outlet quality. Through the two-way glue inlet structure inside the manifold plate and the adjustable needle valve structure, the uniformity of glue outlet is improved, thereby improving the injection molding quality of products.

[0007] The valve needle drive assembly includes a cylinder body, a piston member slidably arranged inside the cylinder body, and an adjusting member. One end of the piston member extends out of the cylinder body through the adjusting member and is connected to a clamping member, and the other end is connected to the valve needle. The valve needle is arranged corresponding to the injection port at the bottom of the cold nozzle. The cold nozzle is integrally formed at the bottom of the cylinder body. A limiting hole adapted to the adjusting member is arranged on the end face of the piston member through an installation fixing block. It can be seen that the cylinder body and the cold nozzle are integrally formed to improve the overall sealing performance and avoid glue overflow during injection molding. The clamping member is used to clamp the adjusting member, thereby locking the adjusting member. One end of the piston member is connected to the adjusting member to achieve adjustment of the stroke of the piston member in the cylinder body on the mold. The valve needle is retracted and extended in alignment with the injection port, and the injection port is blocked by the valve needle to stop the injection molding of the mold.

[0008] The cold nozzle comprises a cold nozzle body, a cold nozzle jacket is disposed on the outer surface of the cold nozzle body, a cooling cavity is formed between the cold nozzle jacket and the cold nozzle body, a coolant is installed in the cooling cavity, the cold nozzle flow channel is disposed at the center of the cold nozzle body, a valve needle guide block adapted to the valve needle is disposed in the cold nozzle flow channel. It can be seen that the cooling cavity is used to make the liquid silicone flowable at a temperature lower than the solidification temperature, which is convenient for cooling the liquid silicone, so that it can maintain liquid state to realize continuous injection molding, and the valve needle guide block is used to guide the up and down movement of the valve needle.

[0009] It also includes an air circuit integration module, which includes an air circuit integration block. The upper surface of the upper template is provided with a plurality of cylinder pipe joint slots corresponding to the cylinder body. An air intake pipe is provided in the cylinder pipe joint slots. The air intake pipe is connected to the cylinder body, and the side of the cylinder body is connected to the air circuit integration block through the air intake pipe. It can be seen that the air circuit integration block is used to integrate the air circuits of multiple liquid silicone cold nozzles on the injection mold, and the pipe joints on the cylinder are connected to the air circuit integration block through the cylinder pipe joint slots to facilitate unified control.

[0010] A guide block is arranged at the top of the cylinder body, and a guide hole adapted to the installation and fixing block is arranged on the guide block. It can be seen that the guide block is used to guide the installation and fixing block through the guide hole.

[0011] The upper template is provided with a wire pressing plate on the slot of the cylinder pipe joint. It can be seen that the wire pressing plate is used to press the air intake pipe.

[0012] The glue injection port is connected to the upper template through a sprue bushing. An adjustment through-hole corresponding to the cold nozzle is provided on the upper surface of the sprue bushing, and the adjustment through-hole is coaxially arranged with the guide hole. Thus, the adjustment through-hole is used to adjust the position of the piston member in the cylinder by adjusting the adjusting member on the surface of the sprue bushing, so as to adjust the stroke of the valve needle.

[0013] The sub-runner is communicated and arranged below the main runner through a runner glue inlet, and a vertical runner is connected between the main runner and the sub-runner. Thus, the vertical runner is used to connect the main runner and the vertical runner. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a schematic partial structural diagram of the present invention; Figure 3 is another schematic partial structural diagram of the present invention; Figure 4 is a cross-sectional view of the runner of the present invention; Figure 5 is a cross-sectional view of the manifold plate of the present invention; Figure 6 is a cross-sectional view of the present invention; Figure 7 is a schematic structural diagram of the cold nozzle of the present invention; Figure 8 is a partial cross-sectional view of the liquid silicone cold nozzle. Detailed Embodiments

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0016] Such as Figures 1 to 8As shown in the figure, the present invention is a liquid silicone injection mold facilitating glue amount control, including an upper template 1, a lower template 2 and a temperature control box. A flow splitter plate 3 is arranged between the upper template 1 and the lower template 2. A glue injection port 11 is arranged on the upper template 1. The glue injection port 11 is connected with a plurality of liquid silicone cold nozzles 4 through the flow splitter plate 3. A main flow channel 31 communicated with the glue injection port 11 and a plurality of sub-flow channels 32 communicated with the main flow channel 31 are arranged inside the flow splitter plate 3. The sub-flow channels 32 are communicated and arranged below the main flow channel 31. The sub-flow channels 32 include a first sub-flow channel and a second sub-flow channel which are symmetrically arranged. Both the first sub-flow channel and the second sub-flow channel include a first arc section 321, a second arc section 322 and a confluence section 323. The radian of the first arc section 321 is smaller than that of the second arc section 322. The liquid silicone cold nozzle 4 includes a valve needle driving assembly 5, a valve needle 51 connected to the output end of the valve needle driving assembly 5 and a cold nozzle 6. First cold nozzle glue inlets 411 and second cold nozzle glue inlets 412 communicated with a cold nozzle flow channel 64 are symmetrically arranged on both sides of the cold nozzle 6. The outlet end of the confluence section 323 of the first sub-flow channel is communicated with the first cold nozzle glue inlet 411. The outlet end of the confluence section 323 of the second sub-flow channel is communicated with the second cold nozzle glue inlet 412. The cold nozzle 6 is integrally connected below the valve needle driving assembly 5. One end of a piston member 53 of the valve needle driving assembly 5 extends out of the upper template 1 and is connected with an adjusting member, and the other end extends into the cold nozzle flow channel 64 and is connected with the valve needle 51 to form an adjustable needle valve structure. In this embodiment, a cold nozzle heat insulation block 65 is arranged at the bottom of the cold nozzle 6. Heating rods or heating coil bars are embedded in the upper template 1 and the lower template 2 for quickly curing and shaping the silicone product after heating. The stroke of the valve needle 51 is adjusted by driving the piston member 53 to move through the adjusting member to adjust the glue output amount. A structural member 100 is injection molded through an injection port 60 at the bottom of the cold nozzle 6.

[0017] The valve needle driving assembly 5 further includes a cylinder block 52. The cold nozzle 6 is integrally formed at the bottom of the cylinder block 52. The piston member 53 is slidably arranged in the cylinder block 52. One end of the piston member 53 extends out of the cylinder block 52 through the adjusting member and is connected with a pressing member, and the other end is connected with the valve needle 51. The valve needle 51 is correspondingly arranged with the injection port 60 at the bottom of the cold nozzle 6. A limiting hole 531 adapted to the adjusting member is arranged on the end face of the piston member 53 through a mounting and fixing block 55. In this embodiment, the cold nozzle 6 and the cylinder block 52 adopt an integrally formed structure, which can effectively prevent external dust and water vapor from entering and has a good sealing effect.

[0018] The cold nozzle 6 includes a cold nozzle body 61, and a cold nozzle jacket 62 is sleeved outside the cold nozzle body 61. A cooling cavity 63 is formed between the cold nozzle jacket 62 and the cold nozzle body 61. A coolant is filled in the cooling cavity 63. A cold nozzle runner 64 is provided at the center of the cold nozzle body 61. A valve needle guide block 641 adapted to the valve needle 51 is provided in the cold nozzle runner 64. First cold nozzle glue inlets 411 and second cold nozzle glue inlets 412 communicating with the cold nozzle runner 64 are symmetrically arranged on both sides of the cold nozzle 6. The outlet ends of the two confluence sections 323 are respectively communicated with the first cold nozzle glue inlet 411 and the second cold nozzle glue inlet 412. In this embodiment, an injection port 60 corresponding to the valve needle 51 is provided at the bottom of the cold nozzle 6. The cold nozzle 6 is made of stainless steel. The cooling cavity 63 adopts a double spiral structure, so that the coolant flows along the spiral structure to provide an efficient cooling effect. The coolant can be water, and the cooling water keeps the silicone fluid state to prevent the cold glue from solidifying.

[0019] A guide block 521 is provided at the inner top end of the cylinder block 52, and a guide hole adapted to the mounting and fixing block 55 is provided on the guide block 521. In this embodiment, a cylinder head is provided on the cylinder block 52, and a jack adapted to the adjusting member is provided on the cylinder head. The jack is correspondingly arranged with the limiting hole 531.

[0020] It further includes a gas circuit integration module. The gas circuit integration module includes a gas circuit integration block 7. A plurality of cylinder pipe joint slots 12 corresponding to the cylinder block 52 are provided on the upper surface of the upper template 1. An intake pipeline is provided in the cylinder pipe joint slots 12. The intake pipeline is communicated with the cylinder block 52. The side of the cylinder block 52 is communicated with the gas circuit integration block 7 through the intake pipeline. In this embodiment, the gas circuit integration module further includes a solenoid valve timing controller, which controls the opening sequence of a plurality of valve needles 51 on the mold. According to requirements, they can be opened simultaneously or in sequence. The intake pipeline is communicated with the cylinder block 52 through a trachea interface 54 communicated with the side of the cylinder block 52. By grooving on the mold, drilling holes in the mold is avoided, thereby reducing the mold processing difficulty.

[0021] A wire pressing plate 14 is provided on the upper template 1 at the cylinder pipe joint slots 12. In this embodiment, the wire pressing plate 14 is connected to the mold by screws, which is convenient for pressing the intake pipeline.

[0022] The injection port 11 is connected to the upper template 1 through a sprue bushing 8. An adjusting through hole 81 corresponding to the cold nozzle 6 is provided on the upper surface of the sprue bushing 8. The adjusting through hole 81 is coaxially arranged with the guide hole. In this embodiment, the guide hole is used for guiding when the adjusting member is adjusted.

[0023] The runner 32 is communicatively connected below the main runner 31 through a runner gate 320, and a vertical runner 33 is connected between the main runner 31 and the runner 32. In this embodiment, the main runner 31 and the runner 32 form an upper and lower double-layer structure through the vertical runner 33, so as to realize the diversion of the flow distribution plate 3 towards the liquid silicone cold nozzle 4.

[0024] The working process of the present invention is as follows: Liquid silicone enters the flow distribution plate 3 from the injection port 11 on the nozzle bushing 8, is divided into two paths through the main runner 31 and enters the runner 32 from the runner gate 320 downward. After the liquid silicone sequentially passes through the first arc section 321, the second arc section 322 and the confluence section 323 from both sides, it enters the cold nozzle runner bidirectionally from the cold nozzle inlets on both sides of the liquid silicone cold nozzle 4. The valve needle driving assembly 5 drives the piston member 53 to drive the valve needle 51 to move upward in the cold nozzle, and the bottom of the valve needle 51 moves away from the injection port 60 at the bottom of the cold nozzle 6. The injection port 60 at the bottom of the cold nozzle 6 is in an open state, so that the liquid silicone is injected downward and flows out. After the product is injection molded, the valve needle 51 moves downward under the drive of the piston member 53, and the end of the valve needle 51 blocks the injection port 60 at the bottom of the cold nozzle 6, thus completing the injection molding of the product. When it is necessary to adjust the stroke of the valve needle 51, the position of the piston member 53 in the cylinder block 52 is adjusted through the adjusting member, so as to adjust the upper limit stroke of the piston member 53. By changing the upward movement stroke of the valve needle 51, the glue output is adjusted.

[0025] Finally, it should be emphasized that the above does not limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A liquid silicone injection mold that is convenient for glue quantity control, comprising an upper mold plate (1), a lower mold plate (2) and a temperature control box, a diverter plate (3) is arranged between the upper mold plate (1) and the lower mold plate (2), and a glue injection port (11) is arranged on the upper mold plate (1), characterized in that: The injection port (11) is connected to a plurality of liquid silicone cold nozzles (4) via the diverter plate (3); a main channel (31) connected to the injection port (11) and a plurality of branch channels (32) connected to the main channel (31) are arranged inside the diverter plate (3); the branch channels (32) are arranged below the main channel (31); the branch channels (32) include a first branch channel and a second branch channel that are symmetrically arranged; the first branch channel and the second branch channel both include a first arc segment (321), a second arc segment (322) and a converging segment (323); the curvature of the first arc segment (321) is smaller than that of the second arc segment (322); the liquid silicone cold nozzle (4) includes a valve needle drive assembly (5), a valve needle drive assembly (5) connected to the valve needle drive assembly (5); A valve needle (51) and a cold nozzle (6) are provided on the output end of the component (5); a first cold nozzle glue inlet (411) and a second cold nozzle glue inlet (412) which are connected to the cold nozzle flow channel (64) are symmetrically arranged on both sides of the cold nozzle (6); the outlet end of the confluent section (323) of the first branch flow channel is connected to the first cold nozzle glue inlet (411); the outlet end of the confluent section (323) of the second branch flow channel is connected to the second cold nozzle glue inlet (412); the cold nozzle (6) is integrally connected to the bottom of the valve needle driving component (5); one end of the piston member (53) of the valve needle driving component (5) extends out of the upper mold plate (1) and is connected to an adjusting member, and the other end extends into the cold nozzle flow channel (64) and is connected to the valve needle (51) to form an adjustable needle valve structure.

2. A liquid silicone injection mold that is easy to control the amount of glue according to claim 1, characterized in that: The valve needle drive assembly (5) also includes a cylinder body (52), the cold nozzle (6) is integrally formed at the bottom of the cylinder body (52), the piston member (53) is slidably arranged in the cylinder body (52), one end of the piston member (53) extends out of the cylinder body (52) through the adjusting member and is connected to a clamping member, and the other end is connected to the valve needle (51), the valve needle (51) is arranged corresponding to the injection port (60) at the bottom of the cold nozzle, and a limiting hole (531) adapted to the adjusting member is arranged on the end surface of the piston member (53) through an installation fixing block (55).

3. A liquid silicone injection mold that is easy to control the amount of glue according to claim 2, characterized in that: A guide block (521) is provided at the top end of the cylinder body (52), and a guide hole adapted to the mounting and fixing block (55) is provided on the guide block (521).

4. The liquid silicone injection mold for easy glue quantity control according to claim 1, characterized in that: The cold nozzle (6) comprises a cold nozzle body (61), the cold nozzle body (61) having a cold nozzle flow channel (64) arranged at the center thereof, and a valve needle guide block (641) adapted to the valve needle (51) being arranged in the cold nozzle flow channel (64).

5. The liquid silicone injection mold for easy glue quantity control according to claim 2, characterized in that: It also includes an air circuit integration module, the air circuit integration module including an air circuit integration block (7), the upper surface of the upper template (1) is provided with a plurality of cylinder pipe joint slots (12) corresponding to the cylinder body (52), an air intake pipe is provided in the cylinder pipe joint slot (12), the air intake pipe is connected to the cylinder body (52), and the side of the cylinder body (52) is connected to the air circuit integration block (7) through the air intake pipe.

6. The liquid silicone injection mold for easy glue quantity control according to claim 5, characterized in that: The upper mold plate (1) is provided with a wire pressing plate (14) on the cylinder pipe joint slot (12).

7. The liquid silicone injection mold for easy glue quantity control according to claim 3, characterized in that: The glue injection port (11) is connected to the upper mold plate (1) via a sprue sleeve (8); an adjustment through hole (81) is provided on the upper surface of the sprue sleeve (8) corresponding to the cold nozzle (6); the adjustment through hole (81) is coaxially arranged with the guide hole.

8. The liquid silicone injection mold for easy glue quantity control according to claim 1, characterized in that: The branch flow channel (32) is arranged below the main flow channel (31) and is in communication with the flow channel glue inlet (320), and a vertical flow channel (33) is connected between the main flow channel (31) and the branch flow channel (32).

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