A mold flow channel structure for reducing residual stress and its application method

Abstract

The present application relates to a mold runner structure for reducing residual stress and an application method thereof, and relates to the field of injection molding technology. The mold runner structure for reducing residual stress includes a runner platform, a main runner is provided in the runner platform, a plurality of branch runners for docking with a mold forming cavity are provided in the runner platform, and the plurality of branch runners are all connected to the main runner, and a plurality of injection ports for docking with an injection molding machine nozzle are provided on the runner platform, and the plurality of injection ports are all connected to the main runner. The coordination of the various components in the present application can enable the molten material to enter the mold forming cavity more evenly, thereby reducing the residual stress caused by uneven local pressure and avoiding the influence of residual stress on the molded product.

Description

Technical Field

[0001] The present application relates to the field of injection molding technology, and in particular to a mold flow channel structure for reducing residual stress and an application method thereof. Background Art

[0002] Injection molding technology occupies an important position in modern manufacturing and is widely used in many industries such as automobiles, electronics, and home appliances. As industrial production continues to increase its requirements for product quality and performance, mold design and manufacturing have become key links in improving the quality of injection molding products.

[0003] Traditional injection molds mainly include a runner structure and a cavity structure. The runner structure includes a runner for transmitting molten material. One end of the runner is connected to the nozzle of the injection molding machine, and the other end is connected to the molding cavity of the cavity structure. The molten material enters the runner through the nozzle of the injection molding machine and is injected into the molding cavity through the runner to be solidified and molded.

[0004] In actual injection molding operations, when the molten material passes through the runner and enters the molding cavity, residual stress is likely to occur due to uneven local pressure, which will have a serious impact on the dimensional accuracy and mechanical properties of the injection molded product, and may easily cause deformation, cracking and other problems in the molded product. Summary of the invention

[0005] In order to improve the problems existing in the above-mentioned technology, the present application provides a mold runner structure for reducing residual stress and an application method thereof.

[0006] The present application provides a mold flow channel structure for reducing residual stress and an application method thereof, which adopts the following technical solutions:

[0007] A mold runner structure for reducing residual stress includes a runner platform, a main runner is provided in the runner platform, a plurality of branch runners for docking with a mold forming cavity are provided in the runner platform, and the plurality of branch runners are all connected to the main runner, and a plurality of injection ports for docking with an injection molding machine nozzle are provided on the runner platform, and the plurality of injection ports are all connected to the main runner.

[0008] By adopting the above technical solution, a plurality of injection ports are provided on the runner table, and the injection ports are used to connect with the nozzle of the injection molding machine. The molten material enters each injection port through the nozzle of the injection molding machine. Under the action of the plurality of injection ports, the molten material can enter the main channel through various areas of the main channel, and the molten material can thus flow smoothly and evenly in the main channel. After that, the molten material flows into each branch channel and enters the mold forming cavity through each branch channel. Since a plurality of branch channels are provided on the runner table, and the plurality of branch channels are connected with various positions of the mold forming cavity, the molten material can enter the mold forming cavity more evenly, thereby reducing the residual stress caused by uneven local pressure and avoiding the influence of residual stress on the molded product.

[0009] Optionally, the flow channel platform includes a first flow channel plate and a second flow channel plate, a heating element is provided on the first flow channel plate and / or the second flow channel plate, the main flow channel includes a first main flow groove and a second main flow groove which are relatively arranged, the first main flow groove is opened on the first flow channel plate and is connected to the plurality of injection ports, the second main flow groove is opened on the second flow channel plate and is connected to the plurality of branch channels, and the first flow channel plate is detachably connected to the second flow channel plate via a connecting member.

[0010] By adopting the above technical solution, the first flow channel plate and the second flow channel plate are arranged opposite to each other and are detachably connected through a connecting piece. When the first flow channel plate and the second flow channel plate are connected, the first main flow groove and the second main flow groove are jointly arranged to form a main flow channel for the molten material to flow. The heating element operates to ensure the temperature of the molten material when it flows, to avoid partial solidification of the molten material due to temperature drop, and to ensure the smooth flow of the molten material. When the molten material flow is abnormal or before the mold is used, the first flow channel plate and the second flow channel plate can be separated, and then the overall situation in the main flow channel can be checked or cleaned to avoid the molten material being retained in some areas of the main flow channel, thereby generating a stagnant area to affect its normal flow.

[0011] Optionally, a sealing gasket is provided on one side of the first flow channel plate opposite to the second flow channel plate, and the connecting member includes a connecting screw, which passes through the first flow channel plate and is threadedly connected to the second flow channel plate.

[0012] By adopting the above technical solution, when the first flow channel plate and the second flow channel plate are connected, the connecting screw is passed through the first flow channel plate, the end of the connecting screw is abutted against the first flow channel plate, and the connecting screw is rotated to thread the connecting screw and the second flow channel plate. The sealing gaskets on the first flow channel plate and the second flow channel plate are squeezed and fit tightly, so that the first flow channel plate and the second flow channel plate are tightly connected, thereby preventing the molten material from leaking through the docking position between the first flow channel plate and the second flow channel plate.

[0013] Optionally, the heating element includes a heating tube, which is disposed in the first flow channel plate and / or the second flow channel plate and is used for allowing a heating medium to flow.

[0014] By adopting the above technical solution, when the molten material flows in the main channel, a heating medium with a higher temperature is introduced into the heating tube. The flow of the heating medium in the heating tube makes the corresponding flow channel plate have a higher temperature, thereby achieving a uniform increase in the temperature of each area in the main channel.

[0015] Optionally, the cross-section of the branch channel gradually decreases in a direction approaching the mold forming cavity.

[0016] By adopting the above technical solution, the cross section of the runner gradually decreases from the end close to the main runner to the end close to the mold forming cavity, thereby effectively reducing the shear force of the molten material when entering the mold forming cavity, and preventing the molten material from being over-sheared at the position of injection into the mold forming cavity, which causes stress concentration. In addition, since the cross section of the runner gradually decreases as it approaches the mold forming cavity, that is, the cross section of the runner reaches the minimum value at the connection to the mold forming cavity, it can ensure that the molten material has a high flow rate before entering the mold forming cavity, so that the mold forming cavity can be quickly filled, and the efficiency of injection molding is also improved.

[0017] Optionally, the flow branch channel includes a plurality of connecting sections connected end to end, each of the connecting sections includes a buffer section and a contraction section, and the cross section of the buffer section is larger than that of the contraction section.

[0018] By adopting the above technical solution, the whole runner adopts a variable cross-section setting. The cross-section of the buffer section is larger than that of the contraction section so that more molten material can flow in. The contraction section can increase the flow rate of the molten material, and the buffer section provides a buffer for the molten material passing through the contraction section. The cooperation of the two can increase the speed of the molten material passing through the runner while ensuring the total flow volume, thereby allowing the molten material to quickly fill the mold molding cavity.

[0019] Optionally, a shielding sensor and a temperature sensor are provided at the connection position between the branch channel and the main channel.

[0020] By adopting the above technical solution, the flow of molten material in the main channel and the branch channel will block the blocking sensor, that is, the blocking sensor is used to sense the flowing molten material. When the blocking sensor senses that no molten material has passed for a period of time, it means that the corresponding branch channel or main channel area is blocked. At this time, timely inspection and maintenance can be carried out to avoid affecting the flow of molten material. The temperature sensor is used to sense the temperature in the corresponding area, and then control the temperature of the molten material in the area.

[0021] Optionally, a circular chamfer is provided at a butt joint between the main flow channel and the branch flow channel.

[0022] By adopting the above technical solution, the setting of the arc chamfer makes the connection between the main channel and the branch channel smoother, so that the molten material can flow into the branch channel more smoothly through the main channel, avoiding the molten material from being stuck at the connection position between the main channel and the branch channel.

[0023] Optionally, the injection port is threadedly connected to a cover for closing the injection port.

[0024] By adopting the above technical solution, the injection port is used to dock with the injection molding machine nozzle and allow the molten material extruded by the injection molding machine to enter the main channel. In the actual operation process, the number of injection ports opened can be selected according to the fluidity of the molten material. When the fluidity of the molten material is good, a small number of injection ports can meet the requirements of smooth flow of the molten material. At this time, some injection ports can be closed by capping; when the fluidity of the molten material is poor, the number of open injection ports can be increased to allow multiple injection ports to inject the molten material synchronously, thereby ensuring that the molten material flows smoothly and evenly in the main channel.

[0025] An application method of a mold flow channel structure for reducing residual stress, using the above-mentioned mold flow channel structure for reducing residual stress, comprises the following steps:

[0026] Each injection port is connected to the injection molding machine nozzle, and the molten material enters the injection port through the injection molding machine nozzle;

[0027] Each branch channel is connected to the mold forming cavity, and each branch channel is evenly distributed around the mold forming cavity. The molten material is distributed to each branch channel through the main channel and enters the mold forming cavity through the branch channel.

[0028] In summary, the present application includes at least one of the following beneficial technical effects:

[0029] 1. Under the action of multiple injection ports, the molten material can enter the main channel through various areas of the main channel, so that the molten material can flow smoothly and evenly in the main channel. After that, the molten material flows into each branch channel and enters the mold molding cavity through each branch channel. Since multiple branch channels are opened on the runner table, the multiple branch channels are connected to various positions of the mold molding cavity, so that the molten material can enter the mold molding cavity more evenly, thereby reducing the residual stress caused by local uneven pressure and avoiding the influence of residual stress on the molded product;

[0030] 2. When the molten material flows abnormally or before the mold is used, the first runner plate and the second runner plate can be separated to check or clean the overall situation in the main runner to prevent the molten material from being retained in some areas of the main runner, thereby causing a stagnant area to affect its normal flow;

[0031] 3. The cross section of the runner gradually decreases from the end close to the main channel to the end close to the mold cavity, which can effectively reduce the shear force of the molten material when entering the mold cavity and prevent the molten material from being over-sheared at the position of injection into the mold cavity, resulting in stress concentration. In addition, since the cross section of the runner gradually decreases as it approaches the mold cavity, that is, the cross section of the runner reaches the minimum value at the connection to the mold cavity, it can ensure that the molten material has a higher flow rate before entering the mold cavity, so that the mold cavity can be quickly filled, and the efficiency of injection molding is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a cut-away side view of a mold runner structure for reducing residual stress in Example 1 of the present application;

[0033] Figure 2 is a top view of the second flow channel plate in Example 1 of the present application;

[0034] Figure 3 It is a sectional side view of a mold runner structure for reducing residual stress in Example 2 of the present application.

[0035] Explanation of the reference numerals: 1. flow channel platform; 101. first flow channel plate; 102. second flow channel plate; 2. main flow channel; 201. first main flow channel; 202. second main flow channel; 3. branch flow channel; 4. injection port; 5. heating element; 501. heating tube; 6. connecting element; 601. connecting screw; 7. connecting section; 701. buffer section; 702. contraction section; 8. arc chamfer; 9. sealing cover. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1-3 This application is described in further detail. Example 1

[0037] Example 1 of the present application discloses a mold flow channel structure for reducing residual stress. Figure 1 and Figure 2 The mold runner structure for reducing residual stress includes a runner platform 1, a main runner 2 is provided in the runner platform 1, a plurality of branch runners 3 for docking with the mold molding cavity are provided in the runner platform 1, and the plurality of branch runners 3 are all connected with the main runner 2, and a plurality of injection ports 4 for docking with the nozzle of the injection molding machine are provided on the runner platform 1, and the plurality of injection ports 4 are all connected with the main runner 2.

[0038] In the embodiment of the present application, the number of injection ports 4 is consistent with the number of runners 3, and the position of each injection port 4 corresponds one-to-one to the position of each runner 3. In other embodiments, the number and position of the injection ports 4 and the runners 3 can be adjusted according to factors such as the solidification rate of the material, the fluidity of the molten material, the position and shape of the mold forming cavity, etc.

[0039] Reference Figure 1 and Figure 2 The flow platform 1 includes a first flow channel plate 101 and a second flow channel plate 102, and the first flow channel plate 101 and the second flow channel plate 102 are provided with a heating element 5 for ensuring the temperature of the molten material when it flows. The main flow channel 2 includes a first main flow groove 201 and a second main flow groove 202 that are arranged opposite to each other, and the first main flow groove 201 and the second main flow groove 202 are jointly surrounded to form a main flow channel 2 for the molten material to flow; the first main flow groove 201 is opened on the first flow channel plate 101 and is connected with each injection port 4, the second main flow groove 202 is opened on the second flow channel plate and is connected with each branch flow channel 3, and the first flow channel plate 101 is detachably connected to the second flow channel plate 102 through a connecting piece 6.

[0040] In the embodiment of the present application, in order to make the molten material flow more smoothly in the main channel 2, a heating element 5 is provided in the first flow channel plate 101 and the second flow channel plate 102. In other embodiments, in order to reduce production costs, the heating element 5 can also be installed in one of the first flow channel plate 101 and the second flow channel plate 102.

[0041] Reference Figure 1 and Figure 2 The heating element 5 includes a plurality of heating tubes 501. A plurality of heating tubes 501 are arranged inside the first flow channel plate 101 and the second flow channel plate 102. The plurality of heating tubes 501 are arranged in parallel with each other and are used for the flow of heating medium. When the molten material flows in the main flow channel 2, a heating medium with a higher temperature is introduced into the heating tubes 501. The flow of the heating medium in the heating tubes 501 makes the corresponding flow channel plate have a higher temperature, thereby achieving a uniform increase in the temperature of each area in the main flow channel 2.

[0042] Reference Figure 1 and Figure 2, a sealing gasket (not shown in the figure) is fixed on the side opposite to the first flow channel plate 101 and the second flow channel plate 102, and the connecting member 6 includes a plurality of connecting screws 601, each connecting screw 601 is perpendicular to the first flow channel plate 101 and the second flow channel plate 102, and each connecting screw 601 passes through the first flow channel plate 101 and is threadedly connected to the second flow channel plate 102; when the first flow channel plate 101 and the second flow channel plate 102 are connected, the connecting screw 601 is passed through the first flow channel plate 101, the end position of the connecting screw 601 abuts against the first flow channel plate 101, and the connecting screw 601 is rotated to thread the connecting screw 601 and the second flow channel plate 102, and the sealing gaskets on the first flow channel plate 101 and the second flow channel plate 102 are squeezed and tightly fitted, so that the first flow channel plate 101 and the second flow channel plate 102 are tightly connected.

[0043] Reference Figure 1 The injection port 4 is threadedly connected with a cover 9 for closing the injection port 4. In actual operation, the number of injection ports 4 opened can be selected according to the fluidity of the molten material. When the fluidity of the molten material is good, a small number of injection ports 4 can meet the requirement of smooth flow of the molten material. At this time, some injection ports 4 can be closed by the cover 9; when the fluidity of the molten material is poor, the number of open injection ports 4 can be increased to allow multiple injection ports 4 to inject the molten material synchronously, thereby ensuring that the molten material flows smoothly and evenly in the main channel 2.

[0044] Reference Figure 1 , the cross section of the runner 3 gradually decreases in the direction close to the mold forming cavity, and the cross section of the runner 3 reaches the minimum value at the connection to the mold forming cavity, ensuring that the molten material has a high flow rate before entering the mold forming cavity, so that the mold forming cavity can be quickly filled. A circular arc chamfer 8 is provided at the docking position between the main channel 2 and the runner 3, so that the molten material can flow into the runner 3 through the main channel 2 more smoothly. An obstruction sensor and a temperature sensor (not shown in the figure) are installed at the docking position between the main channel 2 and the runner 3, that is, where the circular arc chamfer 8 is located. The obstruction sensor is used to sense the flowing molten material. When the obstruction sensor senses that no molten material has passed for a period of time, it means that the corresponding runner 3 or main channel 2 area is blocked. At this time, inspection and maintenance can be carried out in time to avoid affecting the flow of the molten material. The temperature sensor is used to sense the temperature in the corresponding area, and then control the temperature of the molten material in the area.

[0045] The implementation principle of a mold runner structure for reducing residual stress in Example 1 of the present application is as follows: a plurality of injection ports 4 are provided on the runner platform 1, and the injection ports 4 are used to connect with the nozzle of the injection molding machine. The molten material enters each injection port 4 through the nozzle of the injection molding machine. Under the action of the plurality of injection ports 4, the molten material can enter the main flow channel 2 through various regions of the main flow channel 2, and the molten material can thus flow smoothly and evenly in the main flow channel 2. After that, the molten material flows into each branch flow channel 3 and enters the mold forming cavity through each branch flow channel 3. Since a plurality of branch flow channels 3 are provided on the runner platform 1, and the plurality of branch flow channels 3 are connected to various positions of the mold forming cavity, the molten material can enter the mold forming cavity more evenly, thereby reducing the residual stress caused by uneven local pressure and avoiding the influence of residual stress on the molded product. Example 2

[0046] The difference between Example 2 of the present application and Example 1 is that: Figure 3 The branch channel 3 includes a plurality of connecting sections 7 connected end to end, and the plurality of connecting sections 7 are interconnected to form a candied haws-shaped cross section. Each connecting section 7 includes a buffer section 701 and a contraction section 702 , and the cross section of the buffer section 701 is larger than that of the contraction section 702 .

[0047] The implementation principle of a mold runner structure for reducing residual stress in Example 2 of the present application is as follows: the branch channel 3 as a whole adopts a variable cross-section setting, the cross-section of the buffer section 701 is larger than the contraction section 702 and can allow more molten material to flow in, the contraction section 702 can increase the flow rate of the molten material, and the buffer section 701 provides a buffer for the molten material passing through the contraction section 702. The cooperation of the two can increase the speed of the molten material passing through the branch channel 3 while ensuring the total flow volume, thereby allowing the molten material to quickly fill the mold molding cavity. Example 3

[0048] Embodiment 3 of the present application discloses an application method of a mold flow channel structure for reducing residual stress, and the mold flow channel structure for reducing residual stress in embodiment 1 is applied, comprising the following steps:

[0049] Each injection port 4 is connected to the nozzle of the injection molding machine, and the molten material enters the injection port 4 through the nozzle of the injection molding machine;

[0050] Each branch channel 3 is connected to the mold forming cavity, and each branch channel 3 is evenly distributed around the mold forming cavity. The molten material is distributed to each branch channel 3 through the main channel 2 and enters the mold forming cavity through the branch channel 3.

[0051] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0052] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A mold runner structure for reducing residual stress, characterized in that: The invention comprises a runner platform (1), wherein a main runner (2) is provided in the runner platform (1), wherein a plurality of branch runners (3) are provided in the runner platform (1) for docking with a mold forming cavity, wherein the plurality of branch runners (3) are all connected with the main runner (2), wherein the runner platform (1) is provided with a plurality of injection ports (4) for docking with a nozzle of an injection molding machine, wherein the plurality of injection ports (4) are all connected with the main runner (2), wherein a cover (9) for closing the injection port (4) is threadedly connected at the injection port (4); the branch runner (3) comprises a plurality of connecting sections (7) connected end to end, wherein each of the connecting sections (7) comprises a buffer section (701) and a contraction section (702), wherein the cross section of the buffer section (701) is larger than that of the contraction section (702); the runner platform (1) comprises a first runner A plate (101) and a second flow channel plate (102), wherein a heating element (5) is arranged on the first flow channel plate (101) and / or the second flow channel plate (102), the main flow channel (2) comprises a first main flow groove (201) and a second main flow groove (202) which are arranged opposite to each other, the first main flow groove (201) is opened on the first flow channel plate (101) and is connected to the plurality of injection ports (4), the second main flow groove (202) is opened on the second flow channel plate (102) and is connected to the plurality of branch flow channels (3), the first flow channel plate (101) is detachably connected to the second flow channel plate (102) via a connecting piece (6); the number of injection ports (4) is consistent with the number of branch flow channels (3), and the position of each injection port (4) corresponds to the position of each branch flow channel (3) one by one.

2. The mold runner structure for reducing residual stress according to claim 1, characterized in that: A sealing gasket is provided on one side of the first flow channel plate (101) and the other side of the second flow channel plate (102), and the connecting member (6) comprises a connecting screw (601), wherein the connecting screw (601) passes through the first flow channel plate (101) and is threadedly connected to the second flow channel plate (102).

3. The mold runner structure for reducing residual stress according to claim 1, characterized in that: The heating element (5) comprises a heating tube (501), and the heating tube (501) is arranged in the first flow channel plate (101) and / or the second flow channel plate (102) and is used for the flow of a heating medium.

4. The mold runner structure for reducing residual stress according to claim 1, characterized in that: A shielding sensor and a temperature sensor are provided at the connection position between the branch channel (3) and the main channel (2).

5. The mold runner structure for reducing residual stress according to claim 1, characterized in that: A circular chamfer (8) is provided at the butt joint between the main flow channel (2) and the branch flow channel (3).

6. An application method of a mold flow channel structure for reducing residual stress, using a mold flow channel structure for reducing residual stress as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Each injection port (4) is connected to the nozzle of the injection molding machine, and the molten material enters the injection port (4) through the nozzle of the injection molding machine; Each branch channel (3) is connected to the mold forming cavity, and each branch channel (3) is evenly distributed around the mold forming cavity. The molten material is distributed to each branch channel (3) through the main channel (2) and enters the mold forming cavity through the branch channel (3).

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