Plastic injection mold with exhaust structure

Abstract

The invention provides a plastic injection mold with an exhaust structure, which comprises an upper mold and a lower mold, a shape groove for accommodating the mold core is formed in the top of the lower mold, exhaust grooves communicated with the shape groove are formed in the left side and the right side of the top of the lower mold, a cooling cavity is formed in the lower mold and located on the outer side of the shape groove, and a water inlet pipe and a water outlet pipe communicated with the cooling cavity are connected to the front side and the rear side of the lower mold respectively. The invention belongs to the technical field of injection molds. The top of the lower mold is provided with the exhaust groove communicated with the shaped groove, so that a path for exhausting still exists after the upper mold and the lower mold are closed, no air is remained during injection molding of a product, and the arranged auxiliary exhaust assembly can improve the exhaust efficiency and effectively avoid the situation that the air is remained in the mold cavity, so that the product quality is improved. Therefore, the quality of injection products is further ensured.

Description

Technical Field

[0001] This disclosure belongs to the technical field of injection molds, and specifically relates to a plastic injection mold with a venting structure. Background Technology

[0002] Plastic injection molds are the core tools in plastic injection molding. They are precision production equipment used to mass-produce complex-shaped plastic parts efficiently. Their value far exceeds that of the injection molding machine itself, and the design and manufacturing level of the mold directly determines the quality, cost, and production efficiency of the final product.

[0003] In existing technologies, during injection molding, when molten plastic is injected into the mold cavity at high speed, the air already inside the cavity, as well as a small amount of gas that may be generated by the decomposition of the plastic itself, must be expelled. If these gases cannot be expelled in time, they will be compressed at high speed and trapped inside the cavity, leading to a series of product quality problems. Summary of the Invention

[0004] To address the above problems, the present invention provides a plastic injection mold with a venting structure, comprising:

[0005] The upper mold has a mold core machined on its bottom;

[0006] The lower mold has a groove on its top for accommodating the mold core. The top left and right sides of the lower mold have venting grooves that communicate with the groove. A cooling cavity is provided inside the lower mold on the outside of the groove. The front and rear sides of the lower mold are respectively connected to a water inlet pipe and a water outlet pipe that communicate with the cooling cavity. The left and right sides of the lower mold have mounting grooves on the outside of the cooling cavity. The top of the mounting groove has a suction groove that communicates with the venting groove on the side close to the groove.

[0007] An auxiliary venting assembly is installed in the mounting groove to improve the venting efficiency of injection molding. The auxiliary venting assembly includes a piston, a connecting pipe, and a spring element. The piston is slidably installed in the mounting groove. Multiple connecting grooves are opened on the side of the piston near the cooling chamber. The connecting grooves are slidably connected to the connecting pipe through the spring element. The side of the connecting pipe away from the piston extends into the cooling chamber.

[0008] Furthermore, the elastic component includes a support frame and a tension spring. The support frame is fixedly connected to the side of the connecting pipe near the cooling tank, and the side of the support frame near the piston is connected to the piston via the tension spring.

[0009] Furthermore, a sliding groove is provided on the side of the exhaust channel near the shaped groove, at an angle downward away from the shaped groove, and a cutting block for cutting off the overflow is slidably connected in the sliding groove.

[0010] Furthermore, a receiving groove is vertically formed on the side of the exhaust groove near the intake groove, and a top block for lifting the cutting block is placed in the receiving groove. The side of the top block near the piston has a protrusion forming a pressing part that contacts the top of the piston, and the top of the top block is machined with a guide surface for pushing the slice block to move.

[0011] Furthermore, an adjustment groove is provided on the top of the lower mold near the water outlet pipe. An adjustment block is connected to the adjustment groove by a support spring. The bottom of the adjustment block extends into the water outlet pipe to adjust the water outlet cross section.

[0012] Furthermore, the outer wall of the piston is provided with a plurality of annular grooves spaced apart, and a sealing ring that contacts the mounting groove is fixedly connected in the annular groove.

[0013] Furthermore, an anti-detachment ring is fixedly connected to the opening of the mounting groove, and a buffer pad is fixedly connected to the side of the anti-detachment ring near the piston.

[0014] Furthermore, a positioning groove is provided on the outer wall of the connecting pipe, and a sealing ring is connected in the positioning groove. The outer wall of the sealing ring abuts against the inner wall of the connecting groove.

[0015] In summary, the present invention has at least one of the following beneficial technical effects:

[0016] 1. The plastic injection mold with a venting structure has a venting groove on the top of the lower mold that communicates with the mold cavity. This ensures that there is still a path for venting after the upper and lower molds are closed, so that no air is left during product injection. The auxiliary venting component can improve the venting efficiency and effectively prevent air from remaining in the cavity, thereby further ensuring the quality of the injection molded product.

[0017] 2. This plastic injection mold with a venting structure, through the setting of an ejector block and a trimming block, can use the piston to reset after the plastic product is injected to move the ejector block upward, thereby pushing the trimming block to cut off the overflow material that has overflowed into the venting groove, optimizing the post-processing of the injection molded product, and thus effectively improving the production efficiency of the injection molded product;

[0018] 3. This plastic injection mold with a venting structure, through the setting of an adjustment block, can use the upper mold to press the adjustment block into the water outlet pipe after the upper and lower molds are closed. At this time, the drainage cross section of the water outlet pipe is greatly reduced, so the water supply of the inlet pipe is not proportional to the drainage of the outlet pipe. Therefore, when the water inlet pipe continuously supplies water, pressure will be generated in the cooling chamber, which can ensure the stability of piston movement, thereby ensuring the operational stability of the auxiliary venting component. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a plastic injection mold with a venting structure according to the present invention.

[0021] Figure 2 This is a schematic diagram of the state of a plastic injection mold with a venting structure during mold opening, according to the present invention.

[0022] Figure 3 This is a schematic diagram of the water inlet pipe and water outlet pipe in a plastic injection mold with a venting structure according to the present invention.

[0023] Figure 4 This is a schematic diagram of the auxiliary venting component in a plastic injection mold with a venting structure according to the present invention.

[0024] Figure 5 This is a schematic diagram of the auxiliary venting component in a plastic injection mold with a venting structure during the venting process, according to the present invention.

[0025] Figure 6 This is a schematic diagram of the elastic component in a plastic injection mold with a venting structure according to the present invention.

[0026] The reference numerals in the attached figures are as follows:

[0027] 1. Upper mold; 2. Lower mold; 3. Auxiliary venting assembly; 31. Piston; 32. Connecting pipe; 33. Elastic component; 331. Support frame; 332. Tension spring; 4. Mold core; 5. Shaped groove; 6. Venting groove; 7. Cooling chamber; 8. Water inlet pipe; 9. Water outlet pipe; 10. Mounting groove; 11. Suction groove; 12. Connecting groove; 13. Slide groove; 14. Trimming block; 15. Receiving groove; 16. Top block; 17. Extrusion section; 18. Guide surface; 19. Adjustment groove; 20. Support spring; 21. Adjusting block; 22. Annular groove; 23. Sealing ring; 24. Anti-detachment ring; 25. Buffer pad; 26. Positioning groove; 27. Sealing ring. Detailed Implementation

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0032] See also Figure 1 - Figure 6 As shown, according to an embodiment of the present invention, a plastic injection mold with a venting structure is provided, comprising:

[0033] Upper mold 1, with a mold core 4 machined on its bottom;

[0034] The lower mold 2 has a groove 5 machined on its top for accommodating the mold core 4. The left and right sides of the top of the lower mold 2 are provided with exhaust grooves 6 that communicate with the groove 5. The lower mold 2 has a cooling cavity 7 located outside the groove 5. The front and rear sides of the lower mold 2 are respectively connected to the water inlet pipe 8 and the water outlet pipe 9 that communicate with the cooling cavity 7. The left and right sides of the lower mold 2 are provided with mounting grooves 10 located outside the cooling cavity 7. The top of the mounting groove 10 is provided with an air intake groove 11 that communicates with the exhaust groove 6 on the side close to the groove 5.

[0035] The auxiliary exhaust assembly 3 is installed in the mounting groove 10 to improve the venting efficiency of injection molding. The auxiliary exhaust assembly 3 includes a piston 31, a connecting pipe 32 and an elastic member 33. The piston 31 is slidably installed in the mounting groove 10. Multiple connecting grooves 12 are opened on the side of the piston 31 near the cooling chamber 7. The connecting pipe 32 is slidably connected to each connecting groove 12 through the elastic member 33. The side of the connecting pipe 32 away from the piston 31 extends into the cooling chamber 7.

[0036] In this embodiment, observation Figure 1 and Figure 3 It can be seen that by setting up an upper mold 1 and a lower mold 2, the bottom of the upper mold 1 is machined with a mold core 4, and the top of the lower mold 2 is provided with a groove 5 for accommodating the mold core 4, so that when the upper mold 1 and the lower mold 2 are closed, a cavity for injection molding is formed in the middle. At the same time, a cooling cavity 7 is provided in the lower mold 2 outside the groove 5. The front and rear sides of the lower mold 2 are respectively connected to the water inlet pipe 8 and the water outlet pipe 9, which are connected to the cooling cavity 7. Coolant can be injected into the cooling cavity 7 after injection molding to improve the cooling efficiency of the product, thereby improving the injection molding efficiency.

[0037] During injection molding, when molten plastic is injected into the mold cavity at high speed, the air already inside the cavity, as well as a small amount of gas that may be generated from the decomposition of the plastic itself, must be expelled. If these gases cannot be expelled in time, they will be compressed at high speed and trapped inside the cavity, leading to a series of product quality problems.

[0038] Therefore, observe Figure 2 It can be observed that an venting groove 6, which communicates with the forming groove 5, is provided on the top of the lower mold 2. At this time, the upper mold 1 and the lower mold 2 are as follows: Figure 1 When the mold is closed, a gap is left between the upper mold 1 and the lower mold 2 for venting, which can improve the injection molding quality.

[0039] However, in order to avoid increased injection molding costs due to increased overflow, the venting groove 6 cannot be made large. This will significantly reduce the air expulsion efficiency, resulting in a small amount of air remaining in the cavity when the injection is too fast, which will affect the injection molding quality.

[0040] Therefore in Figure 1 and Figure 4 It can be seen that the lower mold 2 has mounting grooves 10 on the left and right sides outside the cooling cavity 7. The top of the mounting groove 10 is provided with a suction groove 11 that communicates with the exhaust groove 6 on the side near the groove 5. At the same time, the mounting groove 10 is provided with an auxiliary exhaust component 3 to improve exhaust efficiency. The auxiliary exhaust component 3 includes a piston 31, a connecting pipe 32 and a spring member 33. The piston 31 is slidably disposed in the mounting groove 10. Multiple connecting grooves 12 are provided on the side of the piston 31 near the cooling cavity 7. The connecting grooves 12 are all slidably connected to the connecting pipe 32 through the spring member 33. The side of the connecting pipe 32 away from the piston 31 extends into the cooling cavity 7.

[0041] When the product is being injection molded, as the molten plastic is injected into the mold cavity, coolant is simultaneously supplied into the cooling cavity 7. The coolant entering the cooling cavity 7 flows through the connecting pipe 32 into the connecting groove 12, thereby pushing the piston 31 within the mounting groove 10. Figure 5 As shown, the space between the left side of the piston 31 and the mounting groove 10 increases, thereby generating negative pressure. This creates negative pressure in the suction groove 11, allowing air to be drawn into the exhaust groove 6. Under the pressure of the negative pressure, the pressure difference between the inside and outside of the cavity increases, thus improving the air discharge efficiency. This effectively solves the problem of residual air during injection molding, thereby effectively improving the quality of injection molded products.

[0042] In a further preferred embodiment of the invention, such as Figure 6 As shown, the elastic component 33 includes a support frame 331 and a tension spring 332. The support frame 331 is fixedly connected to the side of the connecting pipe 32 near the cooling tank. The side of the support frame 331 near the piston 31 is connected to the piston 31 through the tension spring 332. After injection molding is completed, as the coolant stops being injected, the pressure on the tension spring 332 weakens. At this time, the tension spring 332 will pull the piston 31 to reset, so that the auxiliary exhaust component 3 can still stably draw air during the next injection molding, ensuring the stability of continuous use of the injection mold.

[0043] In a further preferred embodiment of the present invention, due to the arrangement of the venting groove 6, when the molten plastic fills the mold cavity, it will inevitably overflow into the venting groove 6, which will cause burrs to appear on the edges of the plastic product. Therefore, observation... Figure 5 It can be seen that the venting groove 6 is provided with a sliding groove 13 on the side close to the shaped groove 5, which is diagonally downward away from the shaped groove 5. A cutting block 14 for cutting off the overflow is slidably connected in the sliding groove 13, so that the cutting block 14 can be used to actively cut off the burrs, optimize the subsequent processing of injection molded products, and further improve the production efficiency of injection molded products.

[0044] In a further preferred embodiment of the present invention, since the edge-cutting block 14 needs to cut off the burrs, it must be positioned near the groove 5 in the exhaust groove 6. This further reduces the exhaust space and affects the exhaust efficiency. Therefore, observation... Figure 4 It can be seen that the exhaust groove 6 has a vertically downward-facing receiving groove 15 on the side near the intake groove 11. A top block 16 for lifting the cutting block 14 is placed in the receiving groove 15. The top block 16 has a protruding pressing part 17 that contacts the top of the piston 31 on the side near the piston 31. The top of the top block 16 is machined with a guide surface 18 for pushing the slice block to move.

[0045] During injection molding, as the coolant is supplied, the piston 31 moves, causing the extrusion section 17 to lose support. Therefore, the unsupported top block 16 will... Figure 5As shown in the state, the top block 16 slides down, and when the top block 16 slides down, the cutting block 14 will naturally lose its support and slide down in the groove 13. At this time, the tip of the cutting block 14 will retract into the groove 13, thus ensuring that the venting performance of the venting groove 6 will not be disturbed during injection molding.

[0046] When the injection molded product has cooled down and is about to be opened, the piston 31 will reset, which will push the extrusion part 17 and the top block 16 upward. When the top block 16 moves upward, the guide surface 18 will push the trimming block 14 to reset, which can effectively cut off the burrs and ensure the stability of the trimming block 14.

[0047] In a further preferred embodiment of the present invention, due to the arrangement of the water outlet pipe 9, after water is supplied by the water inlet pipe 8, the coolant entering the cooling chamber 7 will be directly discharged through the water outlet pipe 9. Therefore, the coolant in the cooling chamber 7 may not be able to provide sufficient pressure for the piston 31 to move. Therefore, in order to ensure the stable operation of the piston 31, observation is required. Figure 2 and Figure 3 It can be seen that an adjustment groove 19 is provided on the top of the lower mold 2 near the water outlet pipe 9. An adjustment block 21 is connected to the adjustment groove 19 through a support spring 20. The bottom of the adjustment block 21 extends into the water outlet pipe 9 to adjust the water outlet cross section.

[0048] When the upper mold 1 and the lower mold 2 are closed, the upper mold 1 will press the adjusting block 21 into the water outlet pipe 9. At this time, the drainage cross section of the water outlet pipe 9 is greatly reduced. Therefore, the water supply of the water inlet pipe 8 is not proportional to the drainage of the water outlet pipe 9. As a result, when the water inlet pipe 8 continuously supplies water, pressure will be generated in the cooling chamber 7, which can ensure the movement stability of the piston 31, thereby ensuring the operation stability of the auxiliary exhaust assembly 3.

[0049] In a further preferred embodiment of the invention, such as Figure 4 As shown, the outer wall of the piston 31 is provided with a plurality of annular grooves 22 spaced apart. A sealing ring 23 that contacts the mounting groove 10 is fixedly connected in the annular groove 22. This can reduce the gap between the piston 31 and the mounting groove 10, improve the sealing performance between the piston 31 and the mounting groove 10, and thus ensure that when the piston 31 moves, a negative pressure for air intake can be stably generated between the piston 31 and the mounting groove 10, thereby ensuring the operational stability of the auxiliary exhaust assembly 3.

[0050] In a further preferred embodiment of the present invention, since the piston 31 is pushed to the side by the water pressure of the coolant, this will cause the piston 31 to continuously move and then dislodge from the mounting groove 10. This not only affects the use of the auxiliary exhaust assembly 3, but also causes coolant leakage. Therefore, observation Figure 4It can be seen that an anti-detachment ring 24 is fixedly connected to the opening of the mounting groove 10. A buffer pad 25 is fixedly connected to the side of the anti-detachment ring 24 near the piston 31. When the piston 31 moves to the point where it comes into contact with the anti-detachment ring 24, it can no longer move, thereby effectively preventing the piston 31 from coming out of the mounting groove 10 and further ensuring the stability of the auxiliary exhaust assembly 3.

[0051] In a further preferred embodiment of the present invention, since the coolant enters the connecting groove 12 for connecting the connecting pipe 32 when the coolant pushes the piston 31 to move, in order to avoid coolant leakage, such as Figure 6 The outer wall of the connecting pipe 32 shown is provided with a positioning groove 26, and a sealing ring 27 is connected in the positioning groove 26. The outer wall of the sealing ring 27 abuts against the inner wall of the connecting groove 12, which can effectively improve the safety of the auxiliary exhaust assembly 3.

[0052] The implementation principle of the above embodiment is as follows: When the upper mold 1 and the lower mold 2 are closed, the upper mold 1 will press the adjusting block 21 into the water outlet pipe 9, so that the drainage section of the water outlet pipe 9 is smaller than the water inlet section of the water inlet pipe 8. At this time, the coolant injected into the cooling chamber 7 will accumulate in the cooling chamber 7 because the drainage speed is lower than the water supply speed. When the coolant fills the cooling chamber 7, the coolant that cannot be discharged in time will increase the pressure in the cooling chamber 7, thereby pushing the piston 31 to move to the side, increasing the space between the piston 31 and the mounting groove 10 and generating negative pressure.

[0053] The generation of negative pressure increases the pressure difference between the inside and outside of the cavity, thus increasing the air discharge efficiency in the cavity during injection molding. This effectively ensures the venting efficiency of the injection mold, prevents air from accumulating in the cavity, and guarantees the quality of the injection molded product.

[0054] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A plastic injection mold with a venting structure, characterized in that, include: The upper mold (1) has a mold core (4) machined at its bottom. The lower mold (2) has a groove (5) on its top for accommodating the mold core (4). The left and right sides of the top of the lower mold (2) are provided with exhaust grooves (6) that communicate with the groove (5). The lower mold (2) has a cooling cavity (7) located outside the groove (5). The front and rear sides of the lower mold (2) are respectively connected with a water inlet pipe (8) and a water outlet pipe (9) that communicate with the cooling cavity (7). The left and right sides of the lower mold (2) are provided with mounting grooves (10) located outside the cooling cavity (7). The top of the mounting groove (10) is provided with an air intake groove (11) that communicates with the exhaust groove (6) on the side close to the groove (5). The auxiliary exhaust assembly (3) is set in the mounting groove (10) to improve the injection molding exhaust efficiency. The auxiliary exhaust assembly (3) includes a piston (31), a connecting pipe (32) and an elastic element (33). The piston (31) is slidably set in the mounting groove (10). Multiple connecting grooves (12) are opened on the side of the piston (31) near the cooling chamber (7). The connecting grooves (12) are all slidably connected to the connecting pipes (32) through the elastic element (33). The side of the connecting pipes (32) away from the piston (31) extends into the cooling chamber (7).

2. A plastic injection mold with a venting structure according to claim 1, characterized in that, The elastic element (33) includes a support frame (331) and a tension spring (332). The support frame (331) is fixedly connected to the side of the connecting pipe (32) near the cooling groove. The side of the support frame (331) near the piston (31) is connected to the piston (31) through the tension spring (332).

3. A plastic injection mold with a venting structure according to claim 2, characterized in that, The exhaust groove (6) has a sliding groove (13) on the side near the groove (5) and in a direction away from the groove (5). A cutting block (14) for cutting off overflow is slidably connected in the sliding groove (13).

4. A plastic injection mold with a venting structure according to claim 3, characterized in that, The exhaust groove (6) has a vertically downward-facing receiving groove (15) on the side near the intake groove (11). A top block (16) for lifting the cutting block (14) is placed in the receiving groove (15). The top block (16) has a protruding pressing part (17) that contacts the top of the piston (31) on the side near the piston (31). The top of the top block (16) is machined with a guide surface (18) for pushing the slice block to move.

5. A plastic injection mold with a venting structure according to claim 4, characterized in that, An adjustment groove (19) is provided on the top of the lower mold (2) near the water outlet pipe (9). An adjustment block (21) is connected to the adjustment groove (19) by a support spring (20). The bottom of the adjustment block (21) extends into the water outlet pipe (9) to adjust the water outlet cross section.

6. A plastic injection mold with a venting structure according to claim 5, characterized in that, The outer wall of the piston (31) is provided with a plurality of annular grooves (22) spaced apart, and a sealing ring (23) that contacts the mounting groove (10) is fixedly connected in the annular groove (22).

7. A plastic injection mold with a venting structure according to claim 6, characterized in that, An anti-detachment ring (24) is fixedly connected to the opening of the mounting groove (10), and a buffer pad (25) is fixedly connected to the side of the anti-detachment ring (24) near the piston (31).

8. A plastic injection mold with a venting structure according to claim 7, characterized in that, The outer wall of the connecting pipe (32) is provided with a positioning groove (26), and a sealing ring (27) is connected inside the positioning groove (26). The outer wall of the sealing ring (27) abuts against the inner wall of the connecting groove (12).

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