In-mold zero-cutting structure of low-pressure injection mold
By designing a zero-cut structure in the mold in a low-pressure injection mold, and automatically cutting the excess periphery of the mask by using the pressure during mold clamping, the problem of wrinkling on the surface of the mask caused by the excess of the mask and low manual cutting efficiency is solved, and an efficient and accurate production process is achieved.
Patent Information
- Application Number
- CN202420528125.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-19
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-03-19
AI Technical Summary
In low-pressure injection molds, the excess periphery of the mask can easily cause wrinkles on the product surface after closing the mold and require manual cutting, which has low efficiency and poor accuracy.
A zero-cut structure in the mold is designed. By setting the cutting blocks and the zero-cutting head in the moving template, and setting the pressing blocks in the fixed template, the excess periphery of the mask is cut by using the pressure during mold clamping.
The mask is automatically cut when clamping, avoiding wrinkles on the surface of the product and manual cutting of excess parts of the mask, improving production efficiency and product quality, and reducing manual cutting costs.
Smart Images
Figure CN222554071U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a low-pressure injection mold in-mold zero-cut structure, belonging to the field of injection molds. Background Art
[0002] Injection molds are one of the main processing equipment for producing plastic products. When producing automotive interior decoration parts, such as A-pillars and B-pillars, there is a method of using cloth decoration, that is, a layer of cloth is attached to the surface of the A-pillar or B-pillar body, and the cloth is integrally formed with the body. This type of mold usually uses low-pressure injection molding, and the cloth is hung on the fixed mold side of the mold with a four-point hook. The area of the cloth is larger than the cavity surface of the fixed mold. The product body adopts an inverted mold or a positive side injection structure, that is, the glue is injected on the movable mold side of the mold, or on the fixed mold side of the mold, and a side injection structure is adopted. When the fixed mold and the movable mold are closed, the excess periphery of the cloth is clamped to prevent the cloth from shifting, and then the glue is injected and molded integrally with the product body. Then the mold is opened, and the periphery of the cloth loses its restraint. Since the product has just been injection molded, the heat has not been completely dissipated, which easily causes the periphery of the cloth to wrinkle, affecting the product quality. In addition, the excess cloth needs to be cut manually, which is inefficient and has poor manual cutting accuracy. Summary of the invention
[0003] The purpose of the utility model is to overcome the shortcomings of the prior art and to provide a low-pressure injection mold in-mold zero-cut structure which can perform in-mold zero-cutting on excess covering cloth while closing the mold so that the covering cloth just covers the surface of the product body without subsequent cutting, thereby achieving good product quality and high production efficiency.
[0004] The technical scheme of the in-mold zero-cut structure of the utility model low-pressure injection mold is as follows: it comprises a fixed mold plate and a movable mold plate, a mold cavity for product injection molding is provided between the fixed mold plate and the movable mold plate, a cloth is provided in the mold cavity, the periphery of the cloth is larger than the periphery of the mold cavity, an in-mold zero-cut mechanism is provided at the periphery where the cloth is larger than the excess periphery of the mold cavity, the in-mold zero-cut mechanism comprises a corresponding cutting block provided in the movable mold plate, an upwardly protruding zero-cutting cutter head is provided on the cutting block, the blade of the zero-cutting cutter head is a plano-convex surface of 0.3-0.8 mm, one side of the plano-convex surface is extended from top to bottom to the surface of the cutting block via a first inclined surface, the other side of the plano-convex surface is extended downward in a 90° vertical surface, transitions through an R angle, and then extends from bottom to top to the surface of the cutting block via a second inclined surface, a corresponding pressing block is provided in the fixed mold plate, the pressing block cooperates with the plano-convex surface, and zero-cuts the cloth at the periphery where the cloth is larger than the excess periphery of the mold cavity.
[0005] The utility model discloses a zero-cut structure in a low-pressure injection mold. During injection molding, the cloth is first laid on the cavity surface of the fixed mold plate. The periphery of the cloth is larger than the cavity surface so that the periphery covers the pressure block. Then, the dynamic mold plate and the fixed mold plate are driven by the power of the injection molding machine to close the mold. When the dynamic mold plate and the fixed mold plate are in contact, the pressure block cooperates with the blade of the zero-cut cutter head to cut the excess periphery of the cloth. Since the blade is a flat convex surface of 0.3-0.8 mm, and one side of the blade extends from top to bottom to the cutting surface through the first inclined surface, and the other side extends downward at a 90° vertical surface, transitions through the R angle, and then extends from bottom to top to the cutting surface through the second inclined surface, the unique shape can be used in large Its strength and service life are guaranteed under large mold clamping force, and the cloth can be cut smoothly. To be precise, the design of the flat convex surface of the blade allows the cloth to be broken by the huge mold clamping force. After being broken, it can also be clamped by the pressing block and the flat convex surface to prevent the cloth from losing its restraint and causing wrinkles and displacement. Then injection molding is carried out, and the molten plastic raw material enters the mold cavity and is integrally formed with the cloth to obtain a product with a cloth. Since the excess periphery of the cloth is cut off when the mold is closed, there is no need to cut the cloth after the product is taken out of the mold, thereby achieving the purpose of zero cutting in the mold. The zero cutting in the mold has good precision and high efficiency, which improves product quality and production efficiency and reduces the cost of manual cloth cutting.
[0006] The utility model discloses a low-pressure injection mold mold-in-mold zero-cut structure, wherein a buffer mechanism is provided in the cutting block, wherein the buffer mechanism includes a buffer hole provided in the cutting block, a buffer pin and a buffer spring provided in the buffer hole, and the buffer pin passes through the buffer hole and is fixed to the movable mold plate. When the mold is closed, the pressing block is pressed down, and the buffer mechanism has a buffering effect on the cutting block, preventing the blade plane of the zero-cutting cutter head from contacting the pressing block too hard, reducing the wear of the blade plane, and reducing the noise generated during the contact. The inclination of the first inclined plane and the second inclined plane is 15-25°, generally 20°, and the length L1 of the first inclined plane and the second inclined plane is 20-30mm, generally 25mm. The length L2 of the vertical plane is 2.5-4.5mm, generally 3mm. The R angle is a 45°R angle. The design of the first inclined plane, the second inclined plane and the vertical plane can not only ensure the strength of the zero-cutting cutter head, prolong its service life, but also ensure that the covering cloth is cut smoothly. The peripheral length L3 of the covering cloth that is larger than the mold cavity is ≥10mm. By pre-calculating, for example, the shrinkage rate of the fabric after injection molding, a 10mm margin can usually ensure that the fabric achieves a zero trimming effect, so that the fabric and the product need to be cut after being integrally formed. However, the shrinkage rates of fabrics made of different materials are different, so the margin can be preset according to the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 This is a schematic diagram of the zero-cut structure in the low-pressure injection mold of the utility model;
[0008] Figure 2 yes Figure 1A local enlarged view of point A;
[0009] Figure 3 It is a cross-sectional schematic diagram of the zero-cutting cutter head of the utility model;
[0010] Figure 4 It is a schematic diagram of the cutting blocks of the utility model being distributed on the moving template. DETAILED DESCRIPTION
[0011] The utility model relates to a low-pressure injection mold mold zero-cut structure, such as Figure 1 — Figure 4 As shown, the mold includes a fixed mold plate 1 and a movable mold plate 2, and a mold cavity 3 for product injection molding is provided between the fixed mold plate and the movable mold plate. A cloth 5 is arranged in the mold cavity, and the periphery of the cloth 5 is larger than the periphery of the mold cavity 3. An in-mold zero-cut mechanism is arranged at the excess periphery of the cloth 5 larger than the mold cavity 3. The in-mold zero-cut mechanism includes a corresponding cutting block 6 arranged in the movable mold plate 2, and an upwardly protruding zero-cutting tool head 7 is arranged on the cutting block. The blade of the zero-cutting tool head 7 is a 0.3-0.8mm flat convex surface 72, one side of the flat convex surface 72 is extended from top to bottom to the surface of the cutting block through a first inclined surface 73, and the other side of the flat convex surface 72 is a 90° vertical surface 74 that is extended downward, and then transitions through an R angle, and then extends from bottom to top to the surface of the cutting block through a second inclined surface 75. A corresponding pressing block 8 is arranged in the fixed mold plate 1, and the pressing block 8 cooperates with the flat convex surface 72 to perform zero cutting on the excess periphery of the cloth 5 larger than the mold cavity 3.
[0012] During injection molding, the covering cloth 5 is first laid on the cavity surface of the fixed mold plate 1. The periphery of the covering cloth 5 is larger than the cavity surface, so that its periphery covers the pressing block 8. Then, the dynamic mold plate 2 and the fixed mold plate 1 are driven by the power of the injection molding machine to close the mold. While the dynamic mold plate and the fixed mold plate are in contact, the pressing block 8 cooperates with the blade 71 of the zero-cutting cutter head 7 to cut the excess periphery of the covering cloth 5. Since the blade is a flat convex surface of 0.3-0.8 mm, and one side of it extends from top to bottom to the cutting surface through the first inclined surface 73, and the other side is a 90° vertical surface 74 that extends downward, passes through the R angle transition, and then extends from bottom to top to the cutting surface through the second inclined surface 75. Its unique shape can not only be used under huge clamping force, but also can be used for cutting. The strength and service life of the cloth can be guaranteed, and the cloth can be cut smoothly. To be precise, the design of the flat convex surface 72 of the blade allows the cloth to be broken by the huge mold clamping force. After being broken, it can also be clamped by the pressing block 8 and the flat convex surface 72 to prevent the cloth from losing its restraint and causing wrinkles and displacement. Then, injection molding is performed, and the molten plastic raw material enters the mold cavity 3 and is integrally formed with the cloth 5 to obtain a product 9 with the cloth 5. Since the excess periphery of the cloth 5 is cut off when the mold is closed, there is no need to cut the cloth after the product is taken out of the mold, thereby achieving the purpose of zero cutting in the mold. The zero cutting in the mold has good precision and high efficiency, which improves product quality and production efficiency and reduces the cost of manual cloth cutting.
[0013] The cutting block 6 is provided with a buffer mechanism, which includes a buffer hole 61 provided in the cutting block 6, a buffer pin 62 and a buffer spring 63 provided in the buffer hole, and the buffer pin 62 passes through the buffer hole 61 and is fixed to the movable mold plate 2. When the mold is closed, the pressing block 8 is pressed down, and the buffer mechanism has a buffering effect on the cutting block 6, preventing the blade plane 72 of the zero-cutting head 7 from contacting the pressing block 8 too hard, reducing the wear of the blade plane, and reducing the noise generated when touching. The inclination of the first inclined surface 73 and the second inclined surface 75 is 15-25°, generally 20°, and the length L1 of the first inclined surface and the second inclined surface 75 is 20-30mm, generally 25mm. The length L2 of the vertical surface 74 is 2.5-4.5mm, generally 3mm. The R angle is a 45°R angle. The design of the first inclined surface, the second inclined surface and the vertical surface can not only ensure the strength of the zero-cutting head, prolong its service life, but also ensure that the covering cloth is cut smoothly. The excess perimeter length L3 of the cover cloth 5 is greater than or equal to 10 mm over the cavity 3. By pre-calculating, for example, calculating the shrinkage rate of the cover cloth after injection molding, a 10 mm margin can usually ensure that the cover cloth achieves a zero trimming effect, so that the cover cloth and the product need to be cut after being integrally formed. However, the shrinkage rates of covers (cloths) of different materials are different, and the margin can be preset according to the actual situation.
[0014] The in-mold zero-cut structure of this solution is suitable for low-pressure injection molds with inverted glue port (glue injection from the movable mold side) and low-pressure molds with upright glue port and side glue injection structure (glue injection from the fixed mold side). The attached drawings do not show the glue injection structure and other components of this mold, but this should not limit its scope of use.
Claims
1. A low-pressure injection mold with an in-mold zero-cut structure, comprising a fixed mold plate (1) and a movable mold plate (2), a mold cavity (3) for product injection molding is provided between the fixed mold plate and the movable mold plate, a covering cloth (5) is provided in the mold cavity, and the periphery of the covering cloth (5) is larger than the periphery of the mold cavity (3), characterized in that: An in-mold zero-cut mechanism is provided at the portion where the covering cloth (5) is larger than the mold cavity (3). The in-mold zero-cut mechanism comprises a corresponding cutting block (6) provided in the movable mold plate (2), and a zero-cutting knife head (7) protruding upward is provided on the cutting block. The blade of the zero-cutting knife head (7) is a 0.3-0.8 mm flat convex surface (72). One side of the flat convex surface (72) extends from top to bottom to the surface of the cutting block via a first inclined surface (73), and the other side of the flat convex surface (72) is a 90° vertical surface (74) extending downward, transitioning through an R angle, and then extending from bottom to top to the surface of the cutting block via a second inclined surface (75). A corresponding pressing block (8) is provided in the fixed mold plate (1). The pressing block (8) cooperates with the flat convex surface (72) to perform zero-cutting on the portion where the covering cloth (5) is larger than the mold cavity (3).
2. The low-pressure injection mold in-mold zero-cut structure according to claim 1, characterized in that The cutting block (6) is provided with a buffer mechanism, the buffer mechanism comprising a buffer hole (61) provided in the cutting block (6), a buffer pin (62) and a buffer spring (63) provided in the buffer hole, and the buffer pin (62) passes through the buffer hole (61) and is fixed to the movable template (2).
3. The low-pressure injection mold in-mold zero-cut structure according to claim 1, characterized in that The inclination of the first inclined surface (73) and the second inclined surface (75) is 15-25°, and the length L1 of the first inclined surface and the second inclined surface (75) is 20-30 mm.
4. The low-pressure injection mold in-mold zero-cut structure according to claim 1, characterized in that The length L2 of the vertical surface (74) is 2.5-4.5 mm.
5. The low-pressure injection mold in-mold zero-cut structure according to claim 1, characterized in that The R angle is 45°.
6. The low-pressure injection mold in-mold zero-cut structure according to claim 1, characterized in that The excess circumferential length L3 of the covering cloth (5) over the mold cavity (3) is ≥10 mm.