A liquid silicone injection mold facilitating glue volume control

Abstract

The present invention relates to the technical field of injection molds, and discloses a liquid silicone injection mold facilitating glue volume control, which includes an upper template, a lower template and a temperature control box. A flow splitter plate is arranged between the upper template and the lower template. A glue injection port is arranged on the upper template. The glue injection port is connected with a plurality of liquid silicone cold nozzles through the flow splitter plate. A main runner communicated with the glue injection port and a plurality of sub-runners communicated with the main runner are arranged inside the flow splitter plate. The sub-runners are communicated and arranged below the main runner. The sub-runners include a symmetrically arranged first sub-runner and a second sub-runner. Both the first sub-runner and the second sub-runner include a first arc section, a second arc section and a confluence section. The liquid silicone cold nozzle includes a valve needle driving assembly, a valve needle connected to the output end of the valve needle driving assembly, and a cold nozzle. The cold 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 cold nozzle runner and is 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 quality-guaranteed runner system for forming products 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 flow splitter 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 flow splitter plate. A main flow channel communicated with the injection port and a plurality of sub-flow channels communicated with the main flow channel are arranged inside the flow splitter plate. The sub-flow channels are arranged below the main flow channel in a communicating manner. The sub-flow channels 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 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 flow channel are symmetrically arranged on both sides of the nozzle. The outlet end of the confluence segment of the first sub-flow channel is communicated with the first nozzle glue inlet. The outlet end of the confluence segment of the second sub-flow channel 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 flow channel 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 flow splitter plate realizes double-layer flow splitting through the main flow channel and the sub-flow channels, facilitating the injection molding of products. The flow splitter 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-flow channel and the second sub-flow channel respectively from the main flow channel, it enters the nozzle flow channel simultaneously from both sides of the valve needle. In this invention, through the combination of double-layer flow channels 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, which may lead to a decline in the glue outlet quality. Through the two-way glue inlet structure inside the flow splitter 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 part in the cylinder body by adjusting the adjusting part 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 sub-runner. Brief Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of the present invention;

[0015] Figure 2 is a schematic partial structural diagram of the present invention;

[0016] Figure 3 is another schematic partial structural diagram of the present invention;

[0017] Figure 4 is a sectional view of the runner of the present invention;

[0018] Figure 5 is a sectional view of the manifold plate of the present invention;

[0019] Figure 6 is a sectional view of the present invention;

[0020] Figure 7 is a schematic structural diagram of the cold nozzle of the present invention;

[0021] Figure 8 is a partial sectional view of the liquid silicone cold nozzle. Detailed Description of the Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention.

[0023] Such as Figures 1 to 8As shown in the figure, the present invention is a liquid silicone injection mold convenient for glue volume 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. An injection port 11 is arranged on the upper template 1. The 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 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 arranged symmetrically. Both the first sub-flow channel and the second sub-flow channel include a first arc segment 321, a second arc segment 322 and a confluence segment 323. The radian of the first arc segment 321 is smaller than the radian of the second arc segment 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 segment 323 of the first sub-flow channel is communicated with the first cold nozzle glue inlet 411. The outlet end of the confluence segment 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. A structural member 100 is injection molded through an injection port 60 at the bottom of the cold nozzle 6.

[0024] The valve needle driving assembly 5 further 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 with a pressing member, and the other end is connected with the valve needle 51. The valve needle 51 is arranged corresponding to 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 body 52 adopt an integrally formed structure, which can effectively prevent external dust and water vapor from entering and has a good sealing effect.

[0025] The cold nozzle 6 includes a cold nozzle body 61, an outer sleeve 62 is provided outside the cold nozzle body 61, a cooling cavity 63 is formed between the cold nozzle outer sleeve 62 and the cold nozzle body 61, a coolant is installed in the cooling cavity 63, a cold nozzle flow channel 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 flow channel 64, a first cold nozzle glue inlet 411 and a second cold nozzle glue inlet 412 communicating with the cold nozzle flow channel 64 are symmetrically arranged on both sides of the cold nozzle 6, and 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, and 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.

[0026] A guide block 521 is provided at the inner top end of the cylinder block 52, and a guide hole adapted to the installation 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, and the jack is correspondingly arranged with the limiting hole 531.

[0027] 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 are provided on the upper surface of the upper template 1 corresponding to the cylinder block 52. An intake pipeline is provided in the cylinder pipe joint slots 12, and 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, and the solenoid valve timing controller 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.

[0028] The upper template 1 is provided with a wire pressing plate 14 on 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.

[0029] The injection port 11 is connected to the upper template 1 through a sprue bushing 8. An adjustment through hole 81 corresponding to the cold nozzle 6 is provided on the upper surface of the sprue bushing 8, and the adjustment through hole 81 is coaxially arranged with the guide hole. In this embodiment, the guide hole is used for guiding when adjusting the adjusting member.

[0030] The said runner 32 is connected and arranged below the main runner 31 through a runner gate 320, and a vertical runner 33 is connected between the main runner 31 and the said 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 manifold plate 3 towards the liquid silicone cold nozzle 4.

[0031] The working process of the present invention is as follows: Liquid silicone enters the manifold plate 3 from the injection port 11 on the sprue bushing 8, is divided into two paths downward through the main runner 31 and enters the runner 32 from the runner gate 320. After the liquid silicone passes through the first arc segment 321, the second arc segment 322 and the confluence segment 323 in sequence from both sides, it enters the cold nozzle runner bidirectionally from the cold nozzle gates 41 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. The bottom of the valve needle 51 moves away from the injection port 60 at the bottom of the cold nozzle 6, and 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 injected, the valve needle 51 moves downward driven by 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 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, and the amount of glue discharged is adjusted by changing the upward movement stroke of the valve needle 51.

[0032] 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 within the protection scope of the present invention.

Claims

1. A liquid silicone injection mold facilitating glue amount control, comprising 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), and a glue injection port (11) is arranged on the upper template (1), characterized in that: The glue injection port (11) is connected to a plurality of liquid silicone cold nozzles (4) through the flow dividing plate (3). A main flow channel (31) communicating with the glue injection port (11) and a plurality of branch flow channels (32) communicating with the main flow channel (31) are arranged inside the flow dividing plate (3). The branch flow channels (32) are arranged below the main flow channel (31) in a communicating manner. The branch flow channels (32) include a first branch flow channel and a second branch flow channel which are symmetrically arranged. Both the first branch flow channel and the second branch flow channel include a first arc segment (321), a second arc segment (322), and a confluence segment (323). The radian of the first arc segment (321) is smaller than the radian of the second arc segment (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 inlet (411) and a second cold nozzle glue inlet (412) communicating with the cold nozzle flow channel (64) are symmetrically arranged on both sides of the cold nozzle (6). The outlet end of the confluence segment (323) of the first branch flow channel is communicated with the first cold nozzle glue inlet (411), and the outlet end of the confluence segment (323) of the second branch 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 the 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. The valve needle driving assembly (5) further 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 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. A limiting hole (531) adapted to the adjusting member is arranged on the end surface of the piston member (53) through a mounting and fixing block (55). A guiding block (521) is arranged at the top end inside the cylinder body (52), and a guiding hole adapted to the mounting and fixing block (55) is arranged on the guiding block (521).

2. The liquid silicone injection mold facilitating glue amount control according to claim 1, wherein: The cold nozzle (6) includes a cold nozzle body (61). A cold nozzle flow channel (64) is arranged at the center of the cold nozzle body (61). A valve needle guiding block (641) adapted to the valve needle (51) is arranged inside the cold nozzle flow channel (64).

3. The liquid silicone injection mold facilitating glue volume control according to claim 2, wherein: 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 body (52) are arranged on the upper surface of the upper template (1). An air inlet pipe is arranged inside the cylinder pipe joint slots (12). The air inlet pipe is communicated with the cylinder body (52). The side of the cylinder body (52) is communicated with the gas circuit integration block (7) through the air inlet pipe.

4. A liquid silicone injection mold facilitating glue volume control according to claim 3, characterized in that: The upper template (1) is provided with a wire pressing plate (14) on the grooved cylinder pipe joint (12).

5. A liquid silicone injection mold facilitating glue volume control according to claim 1, characterized in that: The glue injection port (11) is connected to the upper template (1) through a sprue bushing (8). An adjustment through hole (81) corresponding to the cold nozzle (6) is provided on the upper surface of the sprue bushing (8), and the adjustment through hole (81) is coaxially arranged with the guide hole.

6. The liquid silicone injection mold convenient for glue amount control according to claim 1, wherein: The sub-runner (32) is connected and arranged below the main runner (31) through a runner glue inlet (320). A vertical runner (33) is connected between the main runner (31) and the sub-runner (32).

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