Injection molding process for thin-walled workpieces

Abstract

The application relates to the injection molding field, in particular to a thin-wall workpiece injection molding process, which comprises the following steps: step S1, a movable mold core and a fixed mold core are combined for the first time, and the movable mold core and the fixed mold core form a molding cavity which is not completely closed after being combined for the first time; step S2, injection is carried out in the interior of the molding cavity; and step S3, the movable mold core and the fixed mold core are combined for the second time, so that the molding cavity is closed; the thickness of the closed molding cavity is less than or equal to 0.5 mm; the movable mold core is provided with a glue overflow groove which can be communicated with the closed molding cavity; and the closed molding cavity. The application has the effects of facilitating the guarantee of the injection fullness degree of a thin-wall area and reducing the occurrence of material shortage.

Description

Technical Field

[0001] This application relates to the field of injection molding, and in particular to an injection molding process for thin-walled workpieces. Background Technology

[0002] Thin-walled injection molded products are widely used in fields such as AI glasses, smart wearable devices, medical precision electronic components, and lightweight products. The miniaturization and lightweight design of related electronic products require the continuous reduction of the wall thickness of injection molded parts, which in turn places higher demands on the molding uniformity and structural integrity of thin-walled products.

[0003] In existing related technologies, injection molding of thin-walled workpieces employs a single-stage mold closing method. The injection mechanism injects molten rubber into a closed cavity at a set injection pressure and speed. The rubber flows and expands from the gate towards the end of the cavity, gradually solidifying under the cooling effect of the cavity walls. When the wall thickness and injection parameters are well-matched, single-stage mold closing injection molding allows for more complete filling of the cavity, resulting in a more uniform wall thickness distribution after molding. The appearance quality and structural strength meet the requirements for conventional thin-walled products.

[0004] Regarding the aforementioned technologies, when the required wall thickness of the product is further reduced to below 0.5mm, the flow resistance encountered by the rubber material after entering the closed cavity increases sharply as the wall thickness decreases. The rapid cooling effect of the cavity wall on the rubber material causes the temperature at the flow front to drop rapidly, resulting in poor filling of the rubber material in the thin-walled area and at the end of the cavity. This can easily lead to phenomena such as short shots, material shortages, and uneven wall thickness distribution in the product. Application content

[0005] To ensure full injection molding in thin-walled areas and reduce material shortages, this application provides an injection molding process for thin-walled workpieces.

[0006] This application provides a thin-walled workpiece injection molding process using the following technical solution: A thin-walled workpiece injection molding process includes the following steps: Step S1: The moving mold core and the fixed mold core are closed for the first time, and the moving mold core and the fixed mold core form an incompletely closed molding cavity after the first mold closing; Step S2: Inject molding material into the mold cavity; Step S3: The moving mold core and the fixed mold core close together for the second time, thereby closing the molding cavity; The thickness of the closed molding cavity is less than 0.5 mm, and the moving mold core is provided with an overflow groove that can connect to the closed molding cavity.

[0007] By adopting the above technical solution, the moving mold core and the fixed mold core form a partially closed molding cavity after the first mold closing. This allows the plastic material to expand within a relatively large flow space when injection into the molding cavity, thereby reducing the resistance when the plastic material flows towards the end of the cavity. This promotes full filling of the plastic material and reduces the occurrence of short shots and material shortages. Furthermore, when the moving mold core and the fixed mold core close the molding cavity for the second time, the plastic material continues to fill the thin-walled area under pressure. The overflow groove in the moving mold core connects to the closed molding cavity, allowing excess plastic material to enter the overflow groove. This effectively controls the thickness of the closed molding cavity, resulting in thin-walled workpieces with uniform wall thickness and lightweight construction, which helps to avoid overflow and uneven wall thickness.

[0008] Optionally, the overflow groove is isolated from the molding cavity during the first mold closing, and the overflow groove is connected to the molding cavity during the second mold closing.

[0009] By adopting the above technical solution, the overflow channel remains isolated from the molding cavity during the first mold closing, preventing the material from prematurely entering the overflow channel during the injection stage. This allows the material to concentrate and flow within the unclosed molding cavity, reducing material shortages caused by premature overflow. During the second mold closing, the overflow channel connects to the molding cavity, allowing excess material to enter during the second mold-mold core and stationary core closing process. This controls the cavity thickness while compressing it, resulting in thin-walled workpieces with uniform wall thickness and preventing excessive pressure in the molding cavity.

[0010] Optionally, the moving mold core is provided with an overflow component, which includes an overflow base and an overflow slider. The overflow base has a first glue groove and a second glue groove. The overflow slider slides and engages with the first glue groove, and the overflow slider is elastically connected to the overflow base. The first glue groove is connected to the molding cavity through the sliding of the overflow slider during the second mold closing. The first glue groove is connected to the overflow groove through the second glue groove.

[0011] By adopting the above technical solution, the overflow component located in the moving mold core allows the molding cavity to connect sequentially to the overflow channel via the first and second glue channels after the second mold closing, thus forming an overflow channel for excess material to be discharged, which facilitates the removal of excess material from the molding cavity. The overflow slider slides and is elastically connected to the overflow base, allowing it to slide under the push of the material during the second mold closing, thereby creating a connection between the first glue channel and the molding cavity, facilitating the entry of excess material into the overflow channel via the first and second glue channels. Simultaneously, the elastic connection of the overflow slider facilitates its reset after mold closing, thus enabling subsequent injection molding cycles to repeat.

[0012] Optionally, the glue overflow assembly further includes an adjusting turntable, which has a spiral glue groove extending through it. The first glue groove is connected to the second glue groove through the spiral glue groove. When the adjusting turntable rotates, the connection position between the spiral glue groove and the first glue groove changes along the depth direction of the first glue groove.

[0013] By adopting the above technical solution, the adjusting turntable is perforated with a spiral glue groove, and the first glue groove is connected to the second glue groove through the spiral glue groove. This allows excess glue to enter the overflow groove through the first glue groove, the spiral glue groove, and the second glue groove, thus forming a complete overflow flow path. This facilitates the stable discharge of excess glue from the molding cavity. When the adjusting turntable rotates, the connection position between the spiral glue groove and the first glue groove changes along the depth direction of the first glue groove. This allows the actual connection depth of the overflow flow path to be adjusted with the rotation of the adjusting turntable. This facilitates the adjustment of the excess glue outlet position according to the wall thickness requirements of different thin-walled workpieces, thereby improving the adaptability and adjustment flexibility of the overflow component for molding processes with different wall thicknesses.

[0014] Optionally, the overflow base is rotatably fitted with a drive rod, the end of which is located outside the moving mold core, and the drive rod is used to rotate the adjusting turntable.

[0015] By adopting the above technical solution, the drive rod rotates and engages with the overflow base, with the end of the drive rod located on the outside of the moving mold core. This allows the user to operate the drive rod from outside the moving mold core, thereby driving the adjusting turntable to rotate. This facilitates the adjustment of the connection position between the spiral glue groove and the first glue groove, allowing for the adjustment of the overflow flow path without needing to insert it into the mold. Furthermore, the rotational engagement of the drive rod and the overflow base ensures smooth rotation of the adjusting turntable, reducing the occurrence of misalignment of the overflow components during adjustment and thus helping to maintain the accuracy and stability of the overflow flow path adjustment.

[0016] Optionally, the adjusting turntable is equipped with an adjusting worm gear, and the driving rod is equipped with an adjusting worm, the adjusting worm meshing with the adjusting worm gear.

[0017] By adopting the above technical solution, the adjusting worm gear meshes with the adjusting worm wheel, allowing the rotation of the drive rod to be transmitted to the adjusting turntable via the adjusting worm gear and adjusting worm wheel. This results in a larger transmission reduction ratio for the adjusting turntable, facilitating fine adjustment of the connection position between the spiral glue groove and the first glue groove. Simultaneously, the meshing transmission between the adjusting worm wheel and the adjusting worm gear helps maintain the stability of the adjusting turntable's position after adjustment, reducing the occurrence of the turntable rotating on its own due to the force of the glue material. This, in turn, helps maintain the stability of the overflow position and overflow depth after the glue overflow flow path adjustment.

[0018] Optionally, the glue overflow base includes a first base, a second base, and a third base. The first glue groove is formed in the first base, the adjusting wheel is rotatably engaged with the second base, the second glue groove is formed in the third base, and the first base, the second base, and the third base are joined together by bolts.

[0019] By adopting the above technical solution, the overflow base is assembled from a first base, a second base, and a third base using bolts. The first glue groove, the adjusting turntable, and the second glue groove are each located on a different base, allowing the overflow base to be processed separately according to function. This reduces the processing difficulty of each base and facilitates the molding of the first glue groove, the adjusting turntable, and the second glue groove. Simultaneously, the bolted assembly of the first, second, and third bases allows for disassembly and assembly of the overflow base, facilitating the cleaning and maintenance of the first glue groove, the spiral glue groove, and the second glue groove inside the overflow base, thus helping to maintain the unobstructed flow of the overflow glue.

[0020] Optionally, the second base is provided with a base insertion ring, the base insertion ring is hollow and connected to the first adhesive groove through a spiral adhesive groove, the base insertion ring is inserted into the second adhesive groove, and the outer surface of the base insertion ring is attached to the second adhesive groove.

[0021] By adopting the above technical solution, the base insert ring is hollow and connected to the first glue groove through a spiral glue groove, allowing the glue to enter the interior of the base insert ring through the spiral glue groove, and then flow into the second glue groove through the base insert ring, thus forming a continuous and smooth glue overflow path. The base insert ring is inserted into the second glue groove, and the outer surface of the base insert ring is in contact with the second glue groove, so that a tight fit can be formed between the base insert ring and the second glue groove. This helps to reduce the occurrence of glue leakage from the connection between the base insert ring and the second glue groove, thereby helping to maintain the sealing and unobstructed flow of the glue overflow path in the assembled state.

[0022] Optionally, the end of the drive lever is provided with a torsion slot.

[0023] By adopting the above technical solution, a torsion slot is provided at the end of the drive rod, which allows the user to insert the drive tool into the torsion slot and apply rotational driving force, thereby making the drive rod rotate stably under the drive of the drive tool. This facilitates the rotation of the adjustment turntable from the outside of the moving mold core, reduces slippage between the drive tool and the drive rod, and helps to improve the convenience and stability of the overflow flow path adjustment.

[0024] Optionally, the overflow slider is mounted on the overflow base via a slider spring and a spring mounting block. The two ends of the slider spring are respectively mounted on the overflow slider and the spring mounting block, and the spring mounting block is detachably mounted on the overflow base via bolts.

[0025] By adopting the above technical solution, the overflow slider is mounted on the overflow base via a slider spring and a spring mounting block. Both ends of the slider spring are respectively mounted on the overflow slider and the spring mounting block, forming a stable elastic connection between the overflow slider and the overflow base. This allows the overflow slider to stably reset after the second mold closing, facilitating continuous subsequent injection cycles. Simultaneously, the spring mounting block is detachably mounted to the overflow base via bolts, allowing for the disassembly and assembly of the slider spring and spring mounting block. This facilitates the replacement of slider springs with different spring forces according to the overflow requirements of the molding cavity, thereby improving the adaptability of the overflow component to different injection molding conditions.

[0026] In summary, this application includes at least one of the following beneficial technical effects: After the moving mold core and the fixed mold core close for the first time, an open molding cavity is formed. This allows the material to expand within a relatively large flow space during injection, reducing the resistance as the material flows towards the end of the cavity. This promotes full filling and reduces the occurrence of short shots and material shortages. Furthermore, when the moving mold core and the fixed mold core close for the second time, the material continues to fill the thin-walled area under pressure. The overflow groove in the moving mold core connects to the closed molding cavity, allowing excess material to enter the overflow groove. This effectively controls the thickness of the closed molding cavity, resulting in thin-walled workpieces with uniform wall thickness and lightweight construction, which helps avoid overflow and uneven wall thickness. The overflow channel remains isolated from the molding cavity during the first mold closing, preventing the material from prematurely entering the overflow channel during the injection stage. This allows the material to concentrate and flow within the unclosed molding cavity, reducing material shortages caused by premature overflow. During the second mold closing, the overflow channel connects to the molding cavity, allowing excess material to enter during the second mold-mold core-fixed core closing process. This helps control the cavity thickness while compressing it, resulting in thin-walled workpieces with uniform wall thickness and preventing excessive pressure in the molding cavity. The overflow assembly located on the moving mold core allows the molding cavity to connect sequentially to the overflow channel via the first and second glue channels after the second mold closing, thus forming an overflow channel for excess material to drain. This facilitates the removal of excess material from the molding cavity. The overflow slider slides and is elastically connected to the overflow base, allowing it to slide under the pressure of the material during the second mold closing. This creates a connection between the first glue channel and the molding cavity, facilitating the flow of excess material into the overflow channel via the first and second glue channels. Furthermore, the elastic connection of the overflow slider allows it to reset after mold closing, facilitating subsequent injection molding cycles. Attached Figure Description

[0027] Figure 1This is a diagram illustrating the mold-closing state of the moving mold core and the fixed mold core in Embodiment 1 of this application.

[0028] Figure 2 This is a cross-sectional view of the moving mold core and the fixed mold core in Embodiment 1 of this application.

[0029] Figure 3 yes Figure 2 An enlarged schematic diagram of the path of excess adhesive in part A.

[0030] Figure 4 This is an overall diagram of the adhesive overflow component in Embodiment 1 of this application.

[0031] Figure 5 This is an exploded view of the adhesive overflow component in Embodiment 1 of this application.

[0032] Figure 6 This is a cross-sectional view of the adhesive overflow component in Embodiment 1 of this application.

[0033] Figure 7 This is a diagram illustrating the interaction between the overflow slider and the adjusting turntable in Embodiment 1 of this application.

[0034] Figure 8 This is a diagram illustrating the fit between the adjusting worm and the adjusting worm wheel in Embodiment 1 of this application.

[0035] Explanation of reference numerals in the attached drawings: 1. Moving mold core; 101. Molding cavity; 102. Overflow groove; 2. Fixed mold core; 3. Overflow assembly; 31. First base; 311. First glue groove; 32. Second base; 321. Base insert ring; 33. Third base; 331. Second glue groove; 34. Overflow slider; 341. Slider spring; 342. Spring mounting block; 35. Adjusting turntable; 351. Spiral glue groove; 352. Adjusting worm gear; 36. Drive rod; 361. Torsion slot; 362. Adjusting worm. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0037] Example 1: This application discloses an injection mold for thin-walled workpieces. (Refer to...) Figure 1 The injection mold for thin-walled workpieces includes a moving mold core 1 and a fixed mold core 2. The moving mold core 1 and the fixed mold core 2 are used by an injection molding machine to perform injection molding, mold opening, mold closing, and demolding. Combined with... Figure 2 and Figure 3A molding cavity 101 is formed between the moving mold core 1 and the fixed mold core 2 through mold closing. The molding cavity 101 is used to accommodate molten plastic material and mold thin-walled workpieces. When the moving mold core 1 is brought close to the fixed mold core 2 by the injection molding machine for mold closing, the moving mold core 1 and the fixed mold core 2 enter the first mold closing state and the second mold closing state successively. In the first mold closing state, the molding cavity 101 is closed but not completely closed to the state for solidification, so that the molding cavity 101 has a large filling space, which is conducive to the expansion of the plastic material to the end of the cavity with less flow resistance. In the second mold closing state, the moving mold core 1 is brought closer to the fixed mold core 2, so that the molding cavity 101 is further closed until the molding cavity 101 is fixed in the solidified state, thereby compressing the plastic material to the thickness of the closed molding cavity 101. After closing, the molding cavity 101 has a thin-walled region with a thickness of less than 0.5 mm, so as to obtain thin-walled workpieces with a wall thickness of less than 0.5 mm.

[0038] Reference Figure 3 The moving mold core 1 is provided with an overflow groove 102, which is connected to the molding cavity 101 through two overflow components 3, so as to accommodate excess material in the molding cavity 101 during the second mold closing state. By adjusting the overflow components 3, the overflow groove 102 is separated from the molding cavity 101 during the first mold closing state, so that the overflow groove 102 and the molding cavity 101 are kept separated, thereby allowing the material to concentrate in the unclosed molding cavity 101 and flow to fill it, thereby reducing the material shortage caused by premature overflow of the material, and connecting to the molding cavity 101 during the second mold closing state. Furthermore, by adjusting the overflow components 3 to connect the overflow groove 102 to the molding cavity 101 during the second mold closing state, excess material in the molding cavity 101 can enter the overflow groove 102, which makes it easier to control the thickness of the closed molding cavity 101, and is beneficial to make the wall thickness of thin-walled workpieces more uniform.

[0039] Specifically, refer to Figures 3 to 6The overflow assembly 3 includes an overflow base, an overflow slider 34, and an adjusting turntable 35. The overflow base includes a first base 31, a second base 32, and a third base 33, arranged sequentially downwards. These bases are joined together by bolts (not shown in the figure) to facilitate functional assembly, disassembly, and cleaning. The bottom of the first base 31 has a first glue groove 311, with its front end facing the molding cavity 101 to receive excess glue discharged from the molding cavity 101. The bottom of the second base 32 has an integrally formed base insert ring 321, which is a hollow rectangular shape. The third base 33 has a second glue groove 331, which can be connected to the first glue groove 311. The base insert ring 321 is inserted into and fitted into the second glue groove 331. The outer surface of the base insert ring 321 is attached to the second glue groove 331, so that the glue entering the first glue groove 311 from the overflow glue groove 102 is not easy to leak from the connection between the base insert ring 321 and the second glue groove 331, thereby helping to maintain the sealing and smoothness of the overflow glue flow path in the assembled state.

[0040] The overflow slider 34 slides linearly into the first glue groove 311, and is elastically connected to the overflow base via a slider spring 341. In the first mold-closing state, the overflow slider 34 normally closes the passage between the molding cavity 101 and the first glue groove 311. In the second mold-closing state, as the pressure inside the molding cavity 101 increases, the overflow slider 34 is pushed by the glue material to slide along the first glue groove 311, connecting the first glue groove 311 to the molding cavity 101, thereby guiding excess glue material from the molding cavity 101 into the first glue groove 311.

[0041] Reference Figure 6 The first end of the slider spring 341 is mounted on the overflow slider 34, and the second end of the slider spring 341 is mounted on the overflow base via a spring mounting block 342. The spring mounting block 342 is detachably mounted on the overflow base via bolts (not shown in the figure). The slider spring 341 allows the overflow slider 34 to retract to the designated position of the first glue groove 311 after the molding cavity 101 reaches the set pressure, and to elastically reset after the second mold closing, thus facilitating subsequent injection molding cycles. Simultaneously, the detachable design of the spring mounting block 342 allows the user to replace the slider spring 341 with one of different elastic forces according to the overflow requirements of the molding cavity 101.

[0042] Reference Figure 6 and Figure 7The bottom of the adjusting turntable 35 rotates and engages with the second base 32. A spiral glue groove 351 is formed through the adjusting turntable 35 along its thickness direction, extending from the center of the turning table 35 towards its edge with a gradually increasing radius. The first glue groove 311 connects to the second glue groove 331 via the spiral glue groove 351 and the base insert ring 321, allowing the overflow glue path to sequentially pass through the first glue groove 311, the spiral glue groove 351, the base insert ring 321, the second glue groove 331, and the overflow glue groove 102. When the adjusting turntable 35 rotates, the connection position between the spiral glue groove 351 and the first glue groove 311, i.e., the vertical overlap position, changes along the depth direction of the first glue groove 311. This allows the connection depth of the overflow glue path at the first glue groove 311 to be adjusted accordingly, facilitating the adjustment of the excess glue outlet position according to the different wall thicknesses of thin-walled workpieces.

[0043] The overflow base is rotatably fitted with a drive rod 36. The end of the drive rod 36 is located on the outside of the moving mold core 1, and the end of the drive rod 36 has a torsion slot 361, allowing the user to insert a drive tool into the torsion slot 361 and apply rotational driving force, reducing slippage between the drive tool and the drive rod 36, thereby facilitating the rotation of the adjusting turntable 35 on the outside of the moving mold core 1. (Refer to...) Figure 8 An adjusting worm gear 362 is coaxially fixedly mounted on the drive rod 36, and an adjusting worm wheel 352 is coaxially fixedly mounted on the bottom of the adjusting turntable 35. The adjusting worm gear 362 meshes with the adjusting worm wheel 352, so that the rotation of the drive rod 36 can be transmitted to the adjusting turntable 35 through the adjusting worm gear 362 and the adjusting worm wheel 352, thereby obtaining a large transmission reduction ratio, which facilitates fine adjustment of the connection position between the spiral glue groove 351 and the first glue groove 311. At the same time, the meshing transmission between the adjusting worm gear 362 and the adjusting worm wheel 352 helps to maintain the stability of the adjusting turntable 35 after adjustment.

[0044] The implementation principle of a thin-walled workpiece injection mold according to an embodiment of this application is as follows: Under the drive of the injection molding machine, when the moving mold core 1 and the fixed mold core 2 enter the first mold closing state, the molding cavity 101 is not completely closed to the state where the workpiece is to be solidified. At this time, the overflow groove 102 is separated from the molding cavity 101. The resistance encountered by the flow expansion of the rubber material in the not completely closed molding cavity 101 is small, and it is also easy for air to be discharged, which is conducive to the rubber material filling the end of the molding cavity 101 and the thin-walled area. After the injection is completed, the moving mold core 1 and the fixed mold core 2 begin the second mold closing, so that the molding cavity 101 is compressed and closed to the state where the workpiece is to be solidified. The rubber material in the closed molding cavity 101 is further compressed and fully fills the thin-walled area, and the excess rubber material enters the overflow groove 102 through the overflow component 3, making it easier to control the thickness of the closed molding cavity 101 to be below 0.5mm. Therefore, the full filling in the unclosed state and the compression filling in the closed state are carried out in succession, so that the thin-walled area receives a sufficient supply of rubber material, which helps to ensure the fullness of the injection molding in the thin-walled area and reduce the occurrence of material shortage.

[0045] Example 2: This application discloses an injection molding process for thin-walled workpieces, implemented using the injection mold described in Example 1, including the following steps: Step S1: The moving mold core 1 and the fixed mold core 2 are closed for the first time, and a forming mold cavity 101 is formed after the moving mold core 1 and the fixed mold core 2 are closed for the first time. At this time, the forming mold cavity 101 is closed but not completely closed to the state where the workpiece is to be solidified and formed.

[0046] The injection molding machine drives the moving mold core 1 to move towards the fixed mold core 2, causing the moving mold core 1 and the fixed mold core 2 to enter the first mold closing state. In the first mold closing state, a mold closing gap is maintained between the moving mold core 1 and the fixed mold core 2, and the molding cavity 101 is closed but not completely closed, making the filling space of the molding cavity 101 larger than the filling space in the second mold closing state. At the same time, the overflow slider 34 is held at the front end of the first glue groove 311 by the elastic action of the slider spring 341, closing the passage between the molding cavity 101 and the first glue groove 311, so that the overflow groove 102 is kept isolated from the molding cavity 101 by the overflow component 3. Furthermore, the unclosed state of the molding cavity 101 facilitates the discharge of air inside the molding cavity 101 to the outside, thereby reducing the occurrence of air entrapment.

[0047] Step S2: Inject molding into the mold cavity 101.

[0048] Molten plastic material is injected into the molding cavity 101 in its first closed state using the existing injection mechanism of the injection molding machine. The material expands towards the end of the molding cavity 101 within a large flow space, resulting in low flow resistance. This facilitates the material filling of the end and thin-walled areas of the molding cavity 101. Furthermore, the overflow groove 102 remains isolated from the molding cavity 101, ensuring that the injected material flows and fills within the unclosed molding cavity 101, thus reducing material shortages caused by premature overflow.

[0049] Step S3: The moving mold core 1 and the fixed mold core 2 close the mold for the second time, so that the forming mold cavity 101 is completely closed until the workpiece is solidified and formed.

[0050] The injection molding machine continues to drive the moving mold core 1 toward the fixed mold core 2 to close the mold. The closing gap between the moving mold core 1 and the fixed mold core 2 gradually decreases, causing the molding cavity 101 to be pressurized until it is completely closed to the state where the workpiece is to be solidified. During the closing process, the pressure inside the molding cavity 101 continues to rise, and the rubber material is further compressed and continues to fill the thin-walled area and the end of the cavity. As the pressure inside the molding cavity 101 continues to rise, the overflow slider 34 is pushed back along the first rubber groove 311 by the rubber material and compresses the slider spring 341, so that the first rubber groove 311 is connected to the molding cavity 101. Under the action of pressure, the excess rubber material in the molding cavity 101 enters the overflow groove 102 through the first rubber groove 311, the spiral rubber groove 351, the base insert ring 321, and the second rubber groove 331. After the moving mold core 1 and the fixed mold core 2 are closed in place, the thickness of the closed molding cavity 101 is limited to less than 0.5mm. The rubber material is cooled and formed in the closed molding cavity 101, thereby obtaining a thin-walled workpiece with uniform wall thickness.

[0051] The implementation principle of the thin-walled workpiece injection molding process in this embodiment is as follows: The injection molding machine drives the moving mold core 1 and the fixed mold core 2 to perform the first mold closing, so that the molding cavity 101 is not closed to the state where the workpiece is to be solidified, and the overflow groove 102 is separated from the molding cavity 101. When injection molding is performed into the molding cavity 101, the material expands towards the end of the cavity in a large filling space, with low flow resistance, which is conducive to the material fully filling the end of the molding cavity 101 and the thin-walled area, and the material will not enter the overflow path in advance. When the moving mold core 1 and the fixed mold core 2 perform the second mold closing, the molding cavity 101 is closed by pressure to the state where the workpiece is to be solidified, and the material is further compressed into the thin-walled area. The excess material is guided into the overflow groove 102 through the overflow component 3, so that the thickness of the closed molding cavity 101 is controlled to be below 0.5mm. Therefore, the low-pressure expansion filling in the unclosed state and the high-pressure compression filling in the closed state are carried out in sequence, so that the thin-walled area is successively subjected to low-resistance expansion and compression compensation, which helps to ensure the fullness of the injection molding in the thin-walled area and reduce the occurrence of material shortage.

[0052] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A thin-walled workpiece injection molding process, characterized in that: Includes the following steps: Step S1: The moving mold core (1) and the fixed mold core (2) are closed for the first time, and the moving mold core (1) and the fixed mold core (2) form an incompletely closed molding cavity (101) after the first mold closing; Step S2: Inject molding into the mold cavity (101); Step S3: The moving mold core (1) and the fixed mold core (2) are closed for the second time, so that the molding cavity (101) is closed; The thickness of the closed molding cavity (101) is less than 0.5 mm. The moving mold core (1) is provided with an overflow groove (102). The overflow groove (102) can be connected to the closed molding cavity (101).

2. The injection molding process for thin-walled workpieces according to claim 1, characterized in that: The overflow groove (102) is separated from the molding cavity (101) during the first mold closing, and the overflow groove (102) is connected to the molding cavity (101) during the second mold closing.

3. The injection molding process for thin-walled workpieces according to claim 2, characterized in that: The moving mold core (1) is provided with an overflow component (3). The overflow component (3) includes an overflow base and an overflow slider (34). The overflow base has a first glue groove (311) and a second glue groove (331). The overflow slider (34) slides and engages with the first glue groove (311). The overflow slider (34) is elastically connected to the overflow base. The first glue groove (311) is connected to the molding cavity (101) through the sliding of the overflow slider (34) during the second mold closing. The first glue groove (311) is connected to the overflow groove (102) through the second glue groove (331).

4. The injection molding process for thin-walled workpieces according to claim 3, characterized in that: The glue overflow assembly (3) also includes an adjusting turntable (35), which has a spiral glue groove (351) extending through it. The first glue groove (311) is connected to the second glue groove (331) through the spiral glue groove (351). When the adjusting turntable (35) rotates, the connection position between the spiral glue groove (351) and the first glue groove (311) changes along the depth direction of the first glue groove (311).

5. The injection molding process for thin-walled workpieces according to claim 4, characterized in that: The overflow base is rotatably fitted with a drive rod (36), the end of which is located outside the moving mold core (1). The drive rod (36) is used to rotate the adjusting turntable (35).

6. The injection molding process for thin-walled workpieces according to claim 5, characterized in that: The adjusting turntable (35) is equipped with an adjusting worm gear (352), and the driving rod (36) is equipped with an adjusting worm (362), which meshes with the adjusting worm gear (352).

7. The injection molding process for thin-walled workpieces according to claim 6, characterized in that: The glue overflow base includes a first base (31), a second base (32), and a third base (33). The first glue groove (311) is formed on the first base (31). The adjusting wheel is rotatably fitted to the second base (32). The second glue groove (331) is formed on the third base (33). The first base (31), the second base (32), and the third base (33) are connected by bolts.

8. The injection molding process for thin-walled workpieces according to claim 7, characterized in that: The second base (32) is provided with a base insert ring (321). The base insert ring (321) is hollow and connected to the first adhesive groove (311) through a spiral adhesive groove (351). The base insert ring (321) is inserted into the second adhesive groove (331), and the outer surface of the base insert ring (321) is attached to the second adhesive groove (331).

9. The injection molding process for thin-walled workpieces according to claim 5, characterized in that: The end of the drive lever (36) is provided with a twisting slot (361).

10. The injection molding process for thin-walled workpieces according to claim 3, characterized in that: The overflow slider (34) is mounted on the overflow base via a slider spring (341) and a spring mounting block (342). The two ends of the slider spring (341) are respectively mounted on the overflow slider (34) and the spring mounting block (342). The spring mounting block (342) is detachably mounted on the overflow base via bolts.

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