Hot runner structure capable of reducing injection molding pressure and injection mold

Abstract

The utility model provides a hot runner structure capable of reducing injection molding pressure and an injection mold, and belongs to the field of mold structures. The hot runner structure capable of reducing the injection molding pressure comprises a main runner and a plurality of sub-runners connected with the tail end of the main runner, and further comprises more than one flat discharging structure, the sub-runners are provided with a plurality of groups with the same number as the discharging structures, one side of each discharging structure is provided with a feeding port, and the other side of each discharging structure is provided with a discharging port. One side of each discharging structure is communicated with all the discharging ports of the sub-runners in the corresponding group, the other side of each discharging structure is provided with a discharging port connected with a product cavity, and the width of the discharging port of each discharging structure is in a long strip shape or a long strip arc shape far larger than the height of the discharging port. By widening the runner of the discharge port, the injection molding pressure reaching a product cavity is effectively reduced, so that the appearance quality of a product is improved.

Description

Technical Field

[0001] The utility model relates to the field of die structures, in particular to a hot runner structure for reducing injection pressure, and also relates to an injection mold comprising the hot runner structure for reducing injection pressure. Background Art

[0002] A hot runner mold is a mold that uses a heating device to keep the melt in the runner from solidifying all the time. Due to the advantages of easy molding, short molding time, etc., the hot runner has been widely used in the current market.

[0003] A hot runner is a channel for injecting molten material into the product cavity of a hot runner mold. At present, at the end of the hot runner, injection molding is carried out by setting one or more conical dispensing heads, such as Figure 1 As shown, two sub-runners 2 are separated from the main runner 1, and two dispensing heads 3 are arranged at the ends of the sub-runners for injection molding on both sides of the product. However, for products with a relatively large area, in order to make the glue guiding smoother and the fluidity better, and to smoothly fill the entire product cavity with the molten material, usually the method of increasing the injection pressure and increasing the flow rate of the molten material is adopted. However, when the injection pressure increases, pressure marks will inevitably be generated, thus affecting the appearance of the product. Summary of the Utility Model

[0004] In order to solve the problem of pressure marks on the appearance surface of the product caused by the increase in pressure in the prior art, the utility model provides a hot runner structure for reducing injection pressure, and also provides an injection mold comprising the hot runner structure for reducing injection pressure.

[0005] The hot runner structure of the utility model for reducing injection pressure, the hot runner structure includes a main runner, a plurality of sub-runners connected to the end of the main runner, and also includes more than one flat-shaped discharging structure. The sub-runners are provided with a plurality of groups having the same number as the discharging structures. One side of the discharging structure is an inlet, which is connected to all the outlets of the sub-runners in the corresponding group. The other side of the discharging structure is an outlet connected to the product cavity. The width of the outlet of the discharging structure is a long strip or long strip arc that is much larger than the height of the outlet.

[0006] Furthermore, a converging bridge is arranged on the side of the discharging structure connected to the outlet of the sub-runner, and an inlet matching and communicating with the outlet of the sub-runner is arranged on the converging bridge.

[0007] Furthermore, the converging bridge is a tubular structure matching the shape and width of the inlet of the discharging structure. The arc tubular structure is provided with a discharging end on the side close to the discharging structure and having the same shape as the inlet of the discharging structure.

[0008] Furthermore, the width of the inlet of the discharging structure is 10-20 times the height.

[0009] Further, the converging bridge is an arc-shaped tubular structure that connects all the shunt channels. There are discharge ports on the converging bridge, the number of which is the same as that of the discharge structures. There are several discharge ends on the side of the arc-shaped tubular structure close to the discharge structure, and the shapes and positions of the discharge ends correspond one by one to the feed ports of the discharge structures.

[0010] Further, the width of the discharge port of the discharge structure is not less than the width of the feed port.

[0011] Further, the longitudinal section of the discharge structure from the feed port to the discharge port is a gradually narrowing triangle.

[0012] Further, the shape of the discharge structure is a sector, a square or a trapezoid.

[0013] The present utility model also provides an injection mold including the hot runner structure for reducing injection pressure. The injection mold includes a front mold core, a rear mold core and a product cavity surrounded by the front mold core and the rear mold core. The main runner vertically penetrates the front mold core. The shunt channels and the discharge structures are arranged on the front mold core or the rear mold core, and injection is carried out into the product cavity through more than one discharge structure.

[0014] Further, it also includes an A plate arranged above the front mold core and a heat insulation plate arranged between the A plate and the front mold core. There are several temperature zones on the side of the front mold core away from the rear mold core, and reinforcing ribs are arranged between the temperature zones. There are grooves corresponding to the reinforcing ribs on the heat insulation plate. The lower surface of the heat insulation plate is limited and attached to the bottom surfaces of the respective temperature zones through the reinforcing ribs and the groove structure. Heating and cooling channels are arranged on the front mold core, and the heating and cooling channels are evenly distributed on the respective temperature zones.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] Based on the existing original runner, the runner is creatively widened in design, and the original dispensing method is changed to a linear discharge port, so that the runner area is larger. Without the need to additionally increase pressure, the colloid can flow more smoothly and is easier to reach the product cavity, thereby avoiding pressure marks formed due to increased pressure.

[0017] By setting multiple temperature zones, the mold cavity can be uniformly heated or cooled to maintain the mold temperature balance. The mold temperature balance control makes the glue guiding smoother and the fluidity of the fluid better, thereby reducing the pressure drop, further reducing the injection pressure, and greatly improving the pressure mark problem. Description of the Drawings

[0018] To more clearly illustrate the solutions in the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of the hot runner structure of the prior art;

[0020] Figure 2 Schematic diagram of the hot runner structure of the present utility model;

[0021] Figure 3 Schematic diagram of the injection mold structure of the present utility model;

[0022] Figure 4 and Figure 5 Schematic diagram of the exploded structure of the injection mold of the present utility model. Detailed implementation manners

[0023] Unless otherwise defined, all technical and scientific terms used in the present utility model have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs; the terms used in the description of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model; the terms "including" and "having" and any variations thereof in the description and claims of the present utility model and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of the present utility model or the above drawings are used to distinguish different objects and are not used to describe a specific order.

[0024] Referring to "embodiments" in the present utility model means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present utility model. The phrase appearing at various positions in the description does not necessarily refer to the same embodiment, nor is it an exclusive, independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present utility model can be combined with other embodiments.

[0025] To enable those skilled in the art of the present technology to better understand the solutions of the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the drawings.

[0026] Such as Figure 2As shown, in order to avoid the pressure marks caused by increasing the injection pressure and affecting the appearance of the product, in this example, the existing hot runner structure is improved. Specifically, the hot runner structure in this example includes a main runner 1 and 4 sub-runners 2 connected to the end of the main runner 1. It also includes 2 flat-shaped discharging structures 5. The sub-runners 2 are divided into 2 groups with the same number as the discharging structures 5. One side of the discharging structure 5 is an inlet, which is connected to all the outlets of the sub-runners 2 in the corresponding group. The other side of the discharging structure 5 is an outlet connected to the product cavity. The width of the outlet of the discharging structure is a long strip or long arc shape that is much larger than the height of the outlet.

[0027] This example is for the speaker panel 7 product. Since there is a speaker mounting hole in the middle of the speaker panel 7, the hot runner structure in this example is arranged in the middle of the speaker panel 7, and injection molding is carried out from the two discharging structures 7 in the middle to both sides.

[0028] Preferably, in order to enable the material in the sub-runner 2 to smoothly reach the discharging structure 5 in this example, a converging bridge 4 is provided on the side of the discharging structure connected to the outlet of the sub-runner. The converging bridge 4 is provided with an inlet that matches and communicates with the outlet of the sub-runner 2.

[0029] The converging bridge in this example is a tubular structure that matches the shape and width of the inlet of the discharging structure. The arc-shaped tubular structure is provided with a discharging end on the side close to the discharging structure that is consistent with the shape of the inlet of the discharging structure 5. The end of the sub-runner 2 is integrated with the converging bridge 4. Compared with the existing sub-runner where the flow rate is limited by the pipe diameter, this example can greatly increase the flow rate into the discharging structure 5 and effectively decompose the injection pressure.

[0030] Preferably, the width of the inlet of the discharging structure in this example is 10 - 20 times the height. The width of the outlet of the discharging structure 5 is not less than the width of the inlet, so as to enable the molten material to flow more smoothly. The longitudinal section of the discharging structure 5 in this example is a triangle that gradually narrows from the inlet to the outlet, effectively reducing the connection between the material in the hot runner structure and the product.

[0031] Since the middle of the speaker panel 7 in this example is a circular hole, therefore, the 4 sub-runners 2 in this example are arranged in a fan shape. The inlet of the discharging structure 5 in this example is an arc shape that matches the converging bridge 4, and the outlet of the discharging structure 5 is also an arc shape, making the overall discharging structure 5 of the present invention form a fan shape.

[0032] In this example, in order to improve the pressure balance within the sprue structure, each converging bridge 4 is connected by a connecting bridge 6 to form an arc-shaped tubular structure that connects all the runner channels 2 as a whole. The converging bridge is provided with discharge ports equal in number to the number of discharge structures. The arc-shaped tubular structure is provided with a number of discharge ends on the side close to the discharge structure 5, and the shapes and positions of the discharge ends respectively correspond one by one to the inlet ports of the discharge structure 5.

[0033] Of course, the number of the discharge structures 5 in this example is not limited to 2, and can be set to 3 or even more according to the structure of the product. The number of the runner channels 2 in this example is not limited to two groups of 4 either. For other products, the shapes and numbers of the runner channels 2 and the discharge structures 5 can be set according to the situation, and their structures and positions can also be adjusted according to the product. For example, if the molding structure accommodating the runner channels is square, then a square trapezoid or a square discharge structure can be set.

[0034] Of course, it is preferably that the width of the discharge port of the discharge structure 5 is not less than the width of the inlet port. If the width of the discharge port is slightly less than the width of the inlet port, it is also feasible and within the protection scope of the present invention.

[0035] The present invention creatively widens the end of the runner channel, changing the original dispensing method to a linear discharge port, making the runner channel area larger. Without the need to additionally increase pressure, the colloid can flow more smoothly and is more likely to reach the product cavity, thus avoiding pressure marks formed due to increased pressure.

[0036] In addition, even if the injection pressure of the sprue 1 is increased, through the gentle transition of the discharge structure 5, the molten material reaching the product cavity can be injected at a relatively stable flow rate throughout the product cavity, thereby making the appearance surface of the product better.

[0037] As Figures 3 - 5 shown, the present invention also provides an injection mold including the hot runner structure 302 for reducing injection pressure, which includes a front mold core 200, a rear mold core 300, and a product cavity provided between the front mold core 200 and the rear mold core 300. The product cavity includes an upper mold cavity surface 203 with a smooth top surface and a lower mold cavity surface 301 with a bottom functional structure. The hot runner structure includes a runner passing through the hot runner hole 600. Installation holes are provided in the middle of the upper mold cavity surface 203 and the lower mold cavity surface 301. The hot runner structure in this example is arranged in the installation hole in the middle of the rear mold core 300, and the upper end of the sprue 1 passes through the front mold core 200 and is connected to the runner. An installation groove 205 matching the hot runner structure is provided in the middle of the front mold core 200 in this example. Thus, a sealed structure is formed by enclosing the middle parts of the front mold core 200 and the rear mold core 300, where only the discharge port of the discharge structure 5 is connected to the product cavity and no glue can overflow from the product cavity in other places.

[0038] As Figure 4 and Figure 5 shown, in this example, in order to prevent premature cooling and shaping of the molten material during the flow process, which may affect the flow of the molten material, a heating and cooling channel 400 for arranging heating pipes and cooling pipes is provided on the front mold core 200. The heating and cooling channels 400 are arranged at intervals in sequence along the shape of the sound panel, and the distances from all the heating pipes to the upper mold cavity surface 203 are equal, and the distances from all the cooling pipes to the upper mold cavity surface 203 are equal. Thus, the mold temperature balance of the product cavity can be effectively achieved, so that the appearance of the molded material is smoother and there are no stress marks. Moreover, warping and deformation of the product caused by uneven mold temperature can be prevented.

[0039] Preferably, in order to prevent heat loss, a heat insulation plate 500 is provided on the side of the A plate 100 close to the front mold core 200. A plurality of temperature zones 201 are provided on the surface of the front mold core away from the rear mold core, and reinforcing ribs 202 are provided between the respective temperature zones 201. Grooves corresponding to the reinforcing ribs are provided on the heat insulation plate 500, and the grooves also divide the heat insulation plate 500 into heat insulation units 501. Through the limiting of the reinforcing ribs 202 and the groove structure, the lower surface of the heat insulation plate 500 is made to fit the bottom surfaces of the respective temperature zones.

[0040] By setting a plurality of temperature zones, the mold cavity can be uniformly heated or cooled to maintain the mold temperature balance. The mold temperature balance control makes the glue guiding smoother and the fluidity of the fluid better. Thus, in cooperation with the runner structure of the present invention, the pressure drop is further reduced, the injection pressure is further lowered, and the problem of pressure marks is greatly improved.

[0041] The product processed by the mold structure of this example can be applicable to any article formed by injection molding, especially suitable for a product structure with a large area, and can effectively improve the problem of pressure marks caused by increasing the injection pressure for large-area products.

[0042] The above-described specific embodiments are the preferred embodiments of the present invention, and do not limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to this specific embodiment. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A hot runner structure for reducing injection pressure, characterized in that: The hot runner structure includes a main channel, several branch channels connected to the end of the main channel, and one or more flat discharge structures. The branch channels are provided with several groups with the same number as the discharge structures. One side of the discharge structure is a feed port, which is connected to all the discharge ports of the branch channels in the corresponding group. The other side of the discharge structure is a discharge port connected to the product cavity. The discharge port width of the discharge structure is a long strip or a long arc that is much larger than the height of the discharge port.

2. The hot runner structure for reducing injection pressure according to claim 1, characterized in that: A converging bridge is provided on one side of the discharge structure that is in communication with the outlet of the branch channel, and a feed port that matches and is in communication with the discharge port of the branch channel is provided on the converging bridge.

3. The hot runner structure for reducing injection pressure according to claim 2, characterized in that: The converging bridge is a tubular structure that matches the shape and width of the feed opening of the discharge structure, and a discharge end that is consistent with the shape of the feed opening of the discharge structure is provided on one side of the tubular structure close to the discharge structure.

4. The hot runner structure for reducing injection pressure according to claim 3, characterized in that: The width of the feed opening of the discharge structure is 10-20 times the height.

5. The hot runner structure for reducing injection pressure according to claim 2, characterized in that: The converging bridge is an arc tubular structure connecting all branch channels, and the converging bridge is provided with discharge ports having the same number as the discharge structures. The arc tubular structure is provided with a plurality of discharge ends on one side close to the discharge structure, and the discharge ends correspond to the shapes and positions of the feed ports of the discharge structure respectively.

6. The hot runner structure for reducing injection pressure according to any one of claims 1 to 5, characterized in that: The width of the discharge port of the discharge structure is not less than the width of the feed port.

7. The hot runner structure for reducing injection pressure according to claim 6, characterized in that: The longitudinal section of the discharge structure from the feed port to the discharge port is a gradually narrowing triangle.

8. The hot runner structure for reducing injection pressure according to any one of claims 1 to 5, characterized in that: The shape of the discharging structure is fan-shaped, square or trapezoidal.

9. An injection mold, comprising the hot runner structure for reducing injection pressure according to any one of claims 1 to 8, characterized in that: The injection mold includes a front mold core, a rear mold core and a product cavity enclosed by the front mold core and the rear mold core. The main flow channel vertically penetrates the front mold core. The branch flow channel and the discharge structure are arranged on the front mold core or the rear mold core. Injection is performed into the product cavity through one or more discharge structures.

10. The injection mold according to claim 9, characterized in that: It also includes an A plate arranged above the front mold core and an insulation plate arranged between the A plate and the front mold core. The front mold core is provided with a plurality of temperature zones on a side away from the rear mold core. Reinforcing ribs are provided between the temperature zones. The insulation plate is provided with grooves corresponding to the reinforcing ribs. The lower surface of the insulation plate is limited by the reinforcing ribs and the groove structure and is arranged to fit the bottom surfaces of the temperature zones. The front mold core is provided with heating and cooling channels, and the heating and cooling channels are evenly distributed on the temperature zones.

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