Exhaust structure of injection mold and injection mold
By setting grooves and through holes on the Haval block and embedding venting inserts, the problem of high-temperature and high-pressure air being difficult to expel quickly is solved, thereby improving the venting efficiency of injection molds and product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-03-31
AI Technical Summary
During the injection molding process of PET, PP, PE and PS preforms and tubular products, high temperature and high pressure air is difficult to expel quickly, resulting in quality problems such as flow marks, weld lines, shrinkage marks and scorch marks at the bottle mouth, which are more obvious when there are threads or local thick glue areas at the bottle mouth.
Through-holes and exhaust inserts are installed on the Haval block. The exhaust inserts have exhaust grooves to form airflow channels. Through the exhaust grooves and end exhaust channels that are staggered on the side exhaust channels, high-temperature and high-pressure gases can be quickly discharged.
This effectively avoids bottle mouth quality defects, improves product quality and production efficiency, and reduces processing complexity and costs.
Smart Images
Figure CN224060362U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of injection molding and compression molding equipment technology, specifically to an venting structure for an injection mold and an injection mold. Background Technology
[0002] PET, PP, PE, and PS preforms and tubular structures typically require injection molding to process the preforms. During injection molding, taking PET as an example, molten plastic at 280°C is rapidly filled at high speed and pressure, quickly injecting high-temperature, high-pressure air from the bottom of the preform. This high-temperature, high-pressure air moves towards the bottle neck and reaches the neck. If the high-temperature, high-pressure air at the neck cannot be quickly expelled, it can easily lead to problems such as flow marks, weld lines, shrinkage marks, scorch marks, or even material shortages at the neck. These problems are more likely to occur when there are threads or thick areas of plastic at the neck.
[0003] Therefore, in the injection molding process of PET, PP, PE and PS preforms and tubular structures, how to quickly release the high-temperature and high-pressure air injected to rapidly cool the structure of the bottle mouth with threads or local thick glue areas far from the gate is a technical problem that the industry urgently needs to solve.
[0004] Currently, the industry's technical solution involves setting two local side venting channels and a ring of end venting channels on the Haver block corresponding to the bottle neck molding position to discharge waste gas. However, due to part size limitations, the depth of the end and side venting channels cannot be excessively processed, generally within 0.035mm; otherwise, molten plastic may easily intrude into the corresponding area of the product, leading to problems such as flash and overflow. Therefore, in actual injection molding production, the end venting channels require high-pressure clamping by the injection molding machine, and the side venting channels require radial pressure through a cone to prevent flash. This results in the venting channels not being able to quickly expel air from the mold cavity, making the bottle neck prone to problems such as flow lines, weld lines, shrinkage marks, and scorch marks in actual production. Utility Model Content
[0005] To address the shortcomings of existing technologies, this utility model proposes a venting structure for injection molds and an injection mold itself, which can quickly vent high-temperature and high-pressure gas from the bottle opening into the product. The processing scheme is easy to implement, without requiring changes to the mold structure and operation mode, thus avoiding quality defects caused by insufficient venting.
[0006] The technical solution of this utility model is implemented as follows:
[0007] A venting structure for an injection mold, including
[0008] The Haval block has outwardly extending positioning parts on opposite sides, and a core injection channel through the middle of the positioning parts is formed. The Haval block has a grooved through hole and a side exhaust channel that are connected to the core injection channel.
[0009] An exhaust insert is provided with an exhaust groove and is embedded in the grooved through hole.
[0010] A further technical solution of this embodiment is that the Haval block includes at least two slotted through holes, the slotted through holes are symmetrically distributed on both sides of the parting surface of the Haval block, and the exhaust insert is provided in both slotted through holes.
[0011] A further technical solution of this embodiment is that the exhaust groove is disposed on the surface of the exhaust insert, and its opening faces the outside of the exhaust insert. When the exhaust insert is disposed in the slotted through hole, the exhaust groove and the inner sidewall of the slotted channel form an airflow channel.
[0012] A further technical solution in this embodiment is that the exhaust insert includes an integrally formed exhaust portion and an inlay portion, the exhaust portion and the inlay portion are disposed opposite to each other, the exhaust groove is located on the surface of the exhaust portion, and the thickness of the inlay portion is less than the thickness of the exhaust portion.
[0013] A further technical solution in this embodiment is that the exhaust grooves are distributed crisscrossingly on the surface of the exhaust section.
[0014] A further technical solution in this embodiment is that an exhaust surface is provided on the side of the exhaust portion away from the inlay portion, the depth of the exhaust surface is 0.004mm to 0.015mm, and the end face of the exhaust portion is an arc surface.
[0015] A further technical solution of this embodiment is that the Haval block is provided with an end exhaust channel and at least one pair of side exhaust channels. The end exhaust channels are distributed around the top circumference of the positioning part, and the side exhaust channels are symmetrically arranged and distributed between the slotted through holes.
[0016] A further technical solution in this embodiment is that the outer side of the positioning part is a conical surface, and the outer surface of the exhaust part near the inlay part is flush with the outer surface of the positioning part.
[0017] A further technical solution in this embodiment is that the exhaust insert and the slotted through hole are interference fit.
[0018] This utility model also proposes an injection mold, including a venting structure, a core, a mounting base, a flange, a cavity, and a cavity bottom as described in any of the preceding claims, wherein the core, mounting base, Haver block, flange, cavity, and cavity bottom are coaxially arranged.
[0019] Compared with the prior art, the present invention has the following advantages:
[0020] This invention adds an exhaust insert with an exhaust groove to the existing side exhaust channel. By embedding the exhaust insert into the grooved through hole on the side, the high-temperature and high-pressure gas inside the mold can be fully discharged, and processing can be carried out without changing the original mold structure and operation mode. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of the structure of an injection mold according to the present invention;
[0023] Figure 2 This is a top view of the Haver block in the prior art;
[0024] Figure 3 for Figure 2 Side sectional view;
[0025] Figure 4 This is a schematic diagram of the venting structure of an injection mold according to the present invention;
[0026] Figure 5 This is a perspective view of the Haval block in this utility model;
[0027] Figure 6 This is a cross-sectional view of the Haval block in this utility model;
[0028] Figure 7 This is a perspective view of the exhaust insert in this utility model;
[0029] Figure 8 This is a left view of the exhaust insert in this utility model;
[0030] Figure 9 This is a right view of the exhaust insert in this utility model;
[0031] Figure 10 This is a top view of the exhaust insert in this utility model;
[0032] Figure 11 This is a bottom view of the exhaust insert in this utility model.
[0033] Attached image labels:
[0034] 1-Haval block; 11-Positioning part; 12-Cut through hole; 13-Side exhaust channel; 14-End exhaust channel;
[0035] 2-Exhaust insert; 21-Exhaust groove; 22-Exhaust section; 23-Inlay section; 24-Exhaust surface;
[0036] 3-Core injection; 4-Mounting base; 5-Flange; 6-Cavity. Detailed Implementation
[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0038] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for 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 utility model. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 utility model based on the specific circumstances.
[0040] Injection molds typically include a half block and a cavity. The cavity is used to shape the body of the preform, while the half block is used to shape the neck of the preform. The half block can be separated in half to remove the preform from the cavity. High-temperature and high-pressure gas moves from the bottom of the preform to the neck through the core, thus shaping the molten plastic into a preform.
[0041] Haval blocks, commonly used in existing injection molds, such as Figure 2 and Figure 3 As shown, there is a top venting channel, namely end venting channel C, on the end face of the Haver block. Inside, there are two local side venting channels: side venting channel A and side venting channel B. Within the Haver block, in an area forming a 90-degree angle with side venting channels A and B, there is no venting channel, creating a trapped air zone. For PET preforms or similar products made of PP, PE, or PS with threads and thick plastic sections, the injection molding speed will be affected. The quality of the threaded bottle neck, nozzle, and corresponding areas will always be affected, such as fullness, dimensional accuracy, and product measurement precision.
[0042] Example 1
[0043] To solve the above problems, such as Figure 1 , Figures 4-11 As shown, this utility model discloses a venting structure for an injection mold, including a Haver block 1 and a venting insert 2. The Haver block 1 has outwardly extending positioning portions 11 on opposite sides. The center of the positioning portion 11 forms an injection core 3 channel that penetrates the Haver block 1. The Haver block 1 has a slotted through hole 12 that communicates with the injection core 3 channel and a side venting channel 13. The outer surface of the positioning portion 11 is configured as a conical surface, which is used to ensure that the components in the injection mold are coaxially arranged by positioning through the conical surface.
[0044] Furthermore, such as Figure 6 As shown, the projection of the slotted through hole 12 onto the parting surface of the Haver block 1 spans the middle and the positioning part 11. By enlarging the slotted through hole 12, the volume of the exhaust insert 2 is increased, and the exhaust groove 21 on it can more effectively exhaust high-temperature and high-pressure gas. At the same time, it avoids the problem that the positioning part 11 is too thin and it is difficult to process the hole only in the positioning part 11.
[0045] like Figure 5 , Figure 6 As shown, the Haval block 1 includes at least two slotted through holes 12, which are symmetrically distributed on both sides of the parting surface of the Haval block 1. Each slotted through hole 12 contains an exhaust insert 2. Those skilled in the art will understand that the slotted through holes 12 and the side exhaust channels 13 are spaced apart in the Haval block 1 to achieve the effect of venting trapped air. In this embodiment, the slotted through holes 12 are located in an area at a 90-degree angle to the side exhaust channels A and B, to maximize the venting of trapped air from the product space.
[0046] Furthermore, the venting insert 2 is provided with a venting groove 21, and the venting insert 2 is embedded in the slotted through hole 12. The shape of the venting insert 2 is consistent with the slotted through hole 12, so as not to change the original outer contour of the original Haver block 1, so that the Haver block 1 in this embodiment can still maintain coaxiality with other components through conical surface positioning in the injection mold, and maintain the closedness of the mold product space. Specifically, the venting insert 2 includes an integrally formed venting part 22 and an inlay part 23. The venting part 22 and the inlay part 23 are arranged opposite to each other. The venting groove 21 is located on the surface of the venting part 22, and the thickness of the inlay part 23 is less than the thickness of the venting part 22. The venting part 22 is accommodated in the positioning part 11, and the inlay part 23 is accommodated in the middle of the Haver block 1. The venting insert 2 and the slotted through hole 12 of the Haver block 1 have the same shape, so that the processing of the Haver block 1 can be carried out on the basis of the original structure, and the excavated profile can be used for the processing of the venting insert 2, reducing processing costs and complexity.
[0047] like Figure 7 As shown, the venting groove 21 is disposed on the surface of the venting insert 2, with its opening facing outwards. When the venting insert 2 is disposed in the slotted through hole 12, the venting groove 21 and the inner wall of the slotted channel form an airflow channel. By setting the venting groove 21 on the outer surface, the cumbersome process of drilling holes is eliminated, improving the processing yield of the venting insert 2. At the same time, directly slotting from the outside allows for precise control of the depth of the venting groove 21, avoiding the problem of flash caused by plastic seepage due to the venting groove 21 being too deep.
[0048] like Figures 7 to 11 As shown, the exhaust grooves 21 are distributed in a crisscross pattern on the surface of the exhaust section 22. The crisscrossing exhaust grooves 21 can effectively improve exhaust efficiency.
[0049] like Figures 8 to 11 As shown, an exhaust surface 24 is provided on the side of the exhaust section 22 away from the inlay section 23. The depth of the exhaust surface 24 is 0.004mm to 0.015mm, and the end face of the exhaust section 22 is an arc surface. The height of the exhaust surface 24 is lower than the height of the outer surface of the exhaust section 22. When the exhaust insert 2 is located in the slotted through hole 12, the high-temperature and high-pressure gas enters the exhaust groove 21, which is connected to the outside, through the gap between the exhaust surface 24 and the inner wall of the slotted through hole 12, and quickly transfers the gas to the outside of the mold. The end face of the exhaust section 22 faces the forming space of the mold, and its arc surface smoothly transitions with the inner wall of the Haver block 1, together forming the forming space of the bottle preform mouth.
[0050] A further technical solution of this embodiment is that the Haval block 1 is provided with an end exhaust channel 14 and at least a pair of side exhaust channels 13. The end exhaust channels 14 are distributed around the top circumference of the positioning part 11, and the side exhaust channels 13 are symmetrically arranged and distributed between the slotted through holes 12.
[0051] Furthermore, the outer side of the positioning part 11 is a conical surface, and the outer surface of the exhaust part 22 near the inlay part 23 is flush with the outer surface of the positioning part 11. The outer surface of the exhaust insert 2 in the slotted through hole 12 is flush with the conical surface of the outer surface of the Haval block 1, and the size and shape fit together, so that the positioning part 11 forms a complete conical surface, which cooperates with the inner cone of the mounting base 4 to constrain the Haval block 1 on the central axis.
[0052] Furthermore, the exhaust insert 2 and the slotted through hole 12 are interference fit, making the Haval block 1 and the exhaust insert 2 form a whole.
[0053] Example 2
[0054] like Figure 1 As shown, this utility model proposes an injection mold, including the above-mentioned venting structure, core 3, mounting base 4, flange 5, cavity 6, and cavity 6 bottom. The core 3, mounting base 4, Haver block 1, flange 5, cavity 6, and cavity 6 bottom are coaxially arranged. The core 3, mounting base 4, flange 5, and cavity 6 are positioned by conical surfaces to ensure coaxiality and no eccentricity. When the various components in the injection mold are pressed together, the outer surface of the venting insert 2 in the slotted through hole 12 is flush with the conical surface of the outer surface of the Haver block 1, and the size and shape fit together, so that the positioning part 11 forms a complete conical surface, which cooperates with the inner cone of the mounting base 4. The inner cone of the mounting base 4 provides a lateral force constraint for the combination of Haver block 1 and venting insert 2, ensuring that the pressure impact inside the cavity 6 during high-speed and high-pressure injection will not cause the venting insert 2 to separate from the Haver block 1.
[0055] Specifically, the mounting base 4 and the core assembly form the exhaust channel of the end exhaust channel C. In the mold locking state, the flange 5 and the cone of the mounting base 4 clamp the cone of the Haver block 1, thus forming the molding space for injection filling and establishing the mold exhaust channel system.
[0056] This invention adds two sets of venting inserts 2 to the existing end venting channel C, side venting channel A, and side venting channel B of the mold venting structure. This fundamentally solves the technical problem of the area at a 90-degree angle to side venting channels A and B, which becomes a dead zone where air cannot be vented and becomes trapped. Trapped air enters the venting groove 21, which is connected to the outside, through the gap between the venting surface 24 and the inner wall of the grooved through hole 12, and is quickly transferred to the outside of the mold. This improves product quality and speeds up the injection molding cycle.
[0057] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An exhaust structure of an injection mold characterized by comprising: The haver block (1) is provided with positioning portions (11) extending outward on opposite sides, and a core channel (3) is formed in the middle of the positioning portions (11) to pass through the haver block (1); a groove through hole (12) and a side exhaust channel (13) are formed in the haver block (1) and communicate with the core channel (3). An exhaust insert (2) is provided with an exhaust groove (21), and the exhaust insert (2) is embedded in the groove through hole (12). The haver block (1) includes at least two groove through holes (12) symmetrically distributed on both sides of the parting surface of the haver block (1), and the two groove through holes (12) are provided with the exhaust insert (2).
2. The venting structure of an injection mold according to claim 1, wherein The exhaust groove (21) is arranged on the surface of the exhaust insert (2) and opens outward, and when the exhaust insert (2) is arranged in the groove through hole (12), the exhaust groove (21) and the inner wall of the groove channel form an airflow channel.
3. The venting structure of an injection mold according to claim 1, wherein The exhaust insert (2) includes an exhaust portion (22) and an embedded portion (23) formed integrally, the exhaust portion (22) is arranged opposite to the embedded portion (23), the exhaust groove (21) is located on the surface of the exhaust portion (22), and the thickness of the embedded portion (23) is less than the thickness of the exhaust portion (22).
4. The venting structure of an injection mold according to claim 1, wherein The exhaust groove (21) is distributed longitudinally and transversely on the surface of the exhaust portion (22).
5. The venting structure of an injection mold according to claim 4, wherein The exhaust portion (22) is provided with an exhaust surface (24) on the side away from the embedded portion (23), the depth of the exhaust surface (24) is 0.004mm-0.015mm, and the end surface of the exhaust portion (22) is an arc surface.
6. The venting structure of an injection mold according to claim 4, wherein The haver block (1) is provided with an end exhaust channel (14) and at least one pair of side exhaust channels (13), the end exhaust channel (14) is distributed on the top circumference of the positioning portion (11), and the side exhaust channels (13) are symmetrically arranged and distributed between the groove through holes (12).
7. The venting structure of an injection mold according to claim 1, wherein The outer side of the positioning portion (11) is a conical surface, and the outer surface of the exhaust portion (22) close to the embedded portion (23) is flush with the outer surface of the positioning portion (11).
8. The venting structure of an injection mold according to claim 6, wherein The exhaust insert (2) and the groove through hole (12) are in interference fit.
9. The venting structure of an injection mold according to claim 1, wherein The exhaust structure of the injection mold, the core (3), the mounting seat (4), the flange (5), the cavity (6), and the bottom of the cavity (6) are coaxially arranged.
10. An injection mold characterized in that,