Strong demolding structure of a mold

Abstract

The present application belongs to the field of mould, provide a kind of strong demoulding structure of mould, be set in the front mould of mould, structure includes the columnar insert piece inserted in the fixed hole of mould front mould core and the intermediate insert pin inserted in the column position hole of insert piece, the bottom of insert piece and intermediate insert pin are used to form the columnar component with annular undercuts of product between the annular undercuts of product, insert piece is formed by left half insert piece and right half insert piece, the top of left half insert piece forms protruding hanging table and hanging table is embedded in the guide slot of right half insert piece, left half insert piece and right half insert piece are height limited based on hanging table and guide slot, and guide when left half insert piece moves in radial direction;The present application can solve the problem of product pulling injury or deformation in prior art by using strong demoulding operation on small undercuts.

Description

Technical Field

[0001] This invention relates to the field of molds, and more particularly to a strong demolding structure for molds. Background Technology

[0002] In plastic molds, some products have small undercut surfaces or annular small undercut surfaces. For these small undercut surfaces, the conventional demolding method is to use sliding blocks or angled ejectors. If the mold is compact and there is insufficient space for the product to operate, direct forced demolding is generally used. However, this can easily cause the small undercut surfaces of the product to be scratched or deformed, affecting the product's size and functionality. Summary of the Invention

[0003] In view of the above technical problems, the present invention provides a strong demolding structure for a mold to solve the problem of product tearing or deformation when using strong demolding operation on small undercut surfaces in the prior art.

[0004] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0005] This invention discloses a strong demolding structure for a mold, disposed in the front mold of the mold. The structure includes a columnar insert inserted into a fixing hole in the front mold core and an intermediate insert pin inserted into a columnar hole in the insert. A columnar component with an annular undercut surface is formed between the bottom of the insert and the intermediate insert pin. The insert is formed by a left half insert and a right half insert joined together. The top of the left half insert forms a protruding mounting platform, which is embedded in a guide groove of the right half insert. The left and right half inserts are height-limited based on the mounting platform and the guide groove, and the left half insert is guided during radial movement. A first guide is formed on the surface of the left half insert from top to bottom. The right half insert has a first reset surface and a first tube positioning surface. The surface of the right half insert has a second guide surface, a second reset surface, and a second tube positioning surface corresponding to the left half insert. The outer diameter of the first tube positioning surface and the second tube positioning surface is equal to the inner diameter of the fixing hole. The first reset surface and the second reset surface are concave arc-shaped surfaces. The outer diameter of the second guide surface is equal to the inner diameter of the fixing hole. The outer diameter of the first guide surface is smaller than the inner diameter of the fixing hole. In the mold closed state, the left half insert and the right half insert are located inside the fixing hole. In the mold open state, the first tube positioning surface, the second tube positioning surface, the first reset surface, and the second reset surface are located outside the fixing hole.

[0006] Furthermore, a first cup head is formed at the top of the intermediate insert pin, and a first wire spring is limited in the A plate of the mold. The intermediate insert pin passes through the first wire spring. When the mold is in the closed state, the reset pin on the sprue push plate of the mold presses against the first cup head, causing the first cup head to compress the first wire spring. When the mold is opened, the mold first separates the sprue push plate and the A plate, causing the reset pin to disengage from the intermediate insert pin. The first wire spring causes the intermediate insert pin to disengage from the columnar component of the product.

[0007] Furthermore, a second cup head is formed on the top of the right half insert, and a second wire spring is limited in the fixing hole. When the mold is opened, the columnar component of the product pulls the insert, causing the second cup head to compress the second wire spring.

[0008] Furthermore, the protruding length of the undercut surface of the columnar component of the product is less than the travel distance of the first guide surface when it moves radially.

[0009] The technical solution disclosed herein has the following beneficial effects:

[0010] By designing the insert, utilizing the minute gap between the first guide surface of the left half insert and the fixing hole, and the absence of gap between the first tube surface and the fixing hole, the left half insert cannot move during mold closing. During mold opening, after the first tube surface disengages from the fixing hole, the first guide surface can move radially under tension, causing the left half insert to detach from the product first, followed by the right half insert. Compared to traditional strong demolding methods, this disclosure causes very little or no damage to the product, improves product quality, and requires no additional power source during the movement of the insert. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view of the strong demolding structure in the embodiments of this specification;

[0012] Figure 2 for Figure 1 Enlarged structural diagram of the middle part;

[0013] Figure 3 This is a cross-sectional view of the front mold core, insert, and intermediate insert in the embodiments of this specification;

[0014] Figure 4 This is a schematic diagram of the front mold core in the embodiments of this specification;

[0015] Figure 5 This is a schematic diagram of the product structure in the embodiments of this specification;

[0016] Figure 6 This is an exploded structural diagram of the product, insert, and center pin in the embodiments of this specification;

[0017] Figure 7 This is an exploded structural diagram of the insert and intermediate pin in the embodiments of this specification;

[0018] Figure 8 This is a cross-sectional view of the insert and the center pin in the embodiments of this specification.

[0019] The following are explanations of the reference numerals in the attached figures:

[0020] 1. Front mold core; 101. Fixing hole; 2. Insert; 21. Right half insert; 211. Guide groove; 212. Second guide surface; 213. Second reset surface; 214. Second tube position surface; 215. Second cup head; 22. Left half insert; 221. Hanging platform; 222. First guide surface; 223. First reset surface; 224. First tube position surface; 3. Middle insert pin; 31. First cup head; 4. Product; 41. Columnar component; 5. First wire spring; 6. Sprue push plate; 7. Reset pin; 8. A plate; 9. Fastening assembly; 10. Panel. Detailed Implementation

[0021] The exemplary implementation will now be described more fully with reference to the accompanying drawings.

[0022] The accompanying drawings are merely illustrative of this disclosure. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. It is understood that the scale of the various components in the drawings does not constitute a limitation of this disclosure.

[0023] like Figure 1-8As shown in the embodiment of this specification, a strong demolding structure for a mold is provided, which is disposed in the front mold of the mold. The structure includes a columnar insert 2 inserted into the fixing hole 101 of the front mold core 1 of the mold and an intermediate insert pin 3 inserted into the column position hole of the insert 2. The bottom of the insert 2 and the intermediate insert pin 3 are used to form a columnar component 41 with an annular undercut surface for the product 4. The insert 2 is formed by the left half insert 22 and the right half insert 21. The top of the left half insert 22 forms a protruding hanging platform 221, and the hanging platform 221 is embedded in the guide groove 211 of the right half insert 21. The left half insert 22 and the right half insert 21 are height-limited based on the hanging platform 221 and the guide groove 211, and the left half insert 22 is guided when it moves radially. The surface of the left half insert 22 forms a first guide surface 222 from top to bottom. The right half insert 21 has a first reset surface 223 and a first tube positioning surface 224. The surface of the right half insert 21 has a second guide surface 212, a second reset surface 213 and a second tube positioning surface 214 corresponding to the left half insert 22. The outer diameter of the first tube positioning surface 224 and the second tube positioning surface 214 is equal to the inner diameter of the fixing hole 101. The first reset surface 223 and the second reset surface 213 are concave arc surfaces. The outer diameter of the second guide surface 212 is equal to the inner diameter of the fixing hole 101. The outer diameter of the first guide surface 222 is smaller than the inner diameter of the fixing hole 101. In the mold closed state, the left half insert 22 and the right half insert 21 are located inside the fixing hole 101. In the mold open state, the first tube positioning surface 224, the second tube positioning surface 214, the first reset surface 223 and the second reset surface 213 are located outside the fixing hole 101.

[0024] In this design, since the outer diameter of the first guide surface 222 is smaller than the inner diameter of the fixing hole 101, meaning there is a small gap between the first guide surface 222 and the fixing hole 101, and the outer diameter of the first tube surface 224 is equal to the inner diameter of the fixing hole 101, meaning there is no gap between the first tube surface 224 and the fixing hole 101, the left half insert 22 cannot move when the mold is closed. When the mold is opened, after the first tube surface 224 disengages from the fixing hole 101, the first guide surface 222 can move radially under the action of tension, so that the left half insert 22 disengages from the product 4 first, and the right half insert 21 disengages from the product 4 later. Compared with the traditional strong demolding method, this disclosure causes very little or no damage to the product 4, thus improving the quality of the product 4.

[0025] The top of the intermediate insert 3 forms a first cup head 31. A first wire spring 5 is limited in the A plate 8 of the mold. The intermediate insert 3 passes through the first wire spring 5. When the mold is in the closed state, the reset pin 7 on the sprue push plate 6 of the mold presses against the first cup head 31, causing the first cup head 31 to compress the first wire spring 5. When the mold is opened, the mold first separates the sprue push plate 6 and the A plate 8, causing the reset pin 7 to disengage from the intermediate insert 3. The first wire spring 5 causes the intermediate insert 3 to disengage from the columnar component 41 of the product 4.

[0026] In order to reduce the obstruction of the columnar component 41 of product 4 to insert 2 during demolding, the restoring force of the first spring 5 is used to force the intermediate insert 2 to detach from the columnar component 41 of product 4 when the mold is opened. At the same time, based on the design of the reset pin 7, when the mold is closed, the reset pin 7 presses against the intermediate insert 3 to reset the intermediate insert 3, thus completing the cyclic operation of the intermediate insert 3.

[0027] The top of the right half insert 21 forms a second cup head 215, and a second wire spring is limited in the fixing hole 101. When the mold is opened, the columnar part 41 of the product 4 pulls the insert 2, causing the second cup head 215 to compress the second wire spring.

[0028] During mold opening, product 4 is secured to the rear mold, while the insert 2 of the front mold is secured to the undercut surface of the columnar component 41. Thus, when the front and rear molds separate, the columnar component 41 of product 4 moves the insert 2. At this time, the second cup head 215 compresses the second wire spring, and the first tube surface 224, the second tube surface 214, the first reset surface 223, and the second reset surface 213 extend from the fixing hole 101 of the front mold core 1 (at this time, the first guide surface 222 and the second guide surface 212 are still within the fixing hole 101). Because the fixing hole 101 does not radially limit the first tube surface 224, and the first… Since there is a gap between the guide surface 222 and the fixing hole 101, when the product 4 drives the insert 2 to extend, the tension causes the left half insert 22 to move radially and the left half insert 22 to loosen from the columnar component 41. During this process, the second wire spring provides the insert 2 with a restoring force. That is, after the columnar component 41 of the product 4 is completely loosened from the insert 2, the second wire spring can drive the insert 2 to reset, so that the first tube surface 224, the second tube surface 214, the first reset surface 223, and the second reset surface 213 return to the fixing hole 101, and the left half insert 22 is radially reset using the large arc surface seat of the first reset surface 223.

[0029] The protruding length of the undercut surface of the columnar component 41 of product 4 is less than the travel distance of the first guide surface 222 when it moves radially.

[0030] The radial movement of the first guide surface 222 is to provide space for the columnar component 41 to loosen. Therefore, when its radial movement stroke is greater than the protruding length of the protruding annular flange of the undercut surface, it ensures that these annular flanges are not damaged during demolding.

[0031] In summary, product 4 is PP+GF 30%, and the two columnar parts 41 have a single-sided 0.15mm annular undercut surface on the outside, and no R-corner at the root, which results in a small demolding operation space.

[0032] The annular small undercut surface (0.15mm undercut on one side) of product 4 is formed by insert 2 (left half insert 22, right half insert 21) set in the front mold, and a middle insert pin 3 is made in the column hole; the left half insert 22 is guided by the hanging platform 221 on the right half insert 21 for height limit and radial movement, and the first reset surface 223 of the left half insert 22 uses a large arc surface for reset; the outer diameter of the second guide surface 212 and the second tube surface 214 of the right half insert 21 is R7.5mm, which corresponds to the fixing hole 101 of the front mold core 1. The outer diameter of the first tube surface 224 of the left half insert 22 is R7.5mm, while the outer diameter of the first guide surface 222 is R7.1mm, so it can move radially in the hole of the R7.5mm fixing hole 101 of the front mold core 1 during forced release.

[0033] During mold opening, under the action of the sprue pull rod assembly and the fastening assembly 9, the A plate 8 and the sprue push plate 6 open for the first time, and the sprue breaks off. At this time, the reset pin 7 leaves the middle insert pin 3. Under the action of the first spring 5, the middle insert pin 3 disengages from the middle hole of the columnar component 41 of the product 4, reducing the obstruction when the left half insert 22 and the right half insert 21 are axially pulled. The sprue push plate 6 and the panel 10 open for the second time, and the runner and the sprue automatically fall off. When the A plate 8 and the rear mold open for the third time, the product 4 is pulled to the rear mold by the force of the glue position in the middle deep cavity. At this time, under the action of the annular undercut surface of the product 4, the left half insert 22 and the right half insert 21 in the front mold core 1 are brought out together to the limit distance (first guide surface 222 and second guide surface 212), and the first tube surface 224 of the left half insert 22 is forcibly disengaged. This causes the first guide surface 222 to move radially away from the left undercut position of the columnar component 41, releasing the deformation space. The right undercut surface can then be easily ejected from the right half insert 21, thus ensuring the shape and size requirements of the undercut surface of product 4. After product 4 is separated from the left half insert 22 and the right half insert 21, the right half insert 21 is reset under the action of the second wire spring, and the left half insert 22 is simultaneously axially reset. When the left half insert 22 enters the fixing hole 101 of the front mold core 1, it uses its large arc surface first reset surface 223 to perform radial reset. The A plate 8 and the rear mold plate then open, and the mold opening is completed. Then product 4 is ejected by the ejector pin in the rear mold. Then the mold is closed. During the mold closing process, the middle insert pin 3 is pressed and reset under the action of the reset pin 7. Then the mold is injected with glue, and the next working cycle begins.

[0034] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A strong demolding structure for a mold, characterized in that, The structure, disposed in the front mold of the mold, includes a columnar insert inserted into a fixing hole in the front mold core and an intermediate insert pin inserted into a columnar hole in the insert. A columnar component with an annular undercut surface is formed between the bottom of the insert and the intermediate insert pin. The insert is formed by a left half-insert and a right half-insert joined together. The top of the left half-insert forms a protruding mounting platform, which is embedded in a guide groove of the right half-insert. The left and right half-inserts are height-limited based on the mounting platform and the guide groove, and the left half-insert is guided during radial movement. A first guide surface and a first reset surface are formed on the surface of the left half-insert from top to bottom. The right half of the insert has a second guide surface, a second reset surface, and a second tube surface corresponding to the left half of the insert. The outer diameters of the first tube surface and the second tube surface are equal to the inner diameter of the fixing hole. The first reset surface and the second reset surface are concave arc surfaces. The outer diameter of the second guide surface is equal to the inner diameter of the fixing hole. The outer diameter of the first guide surface is smaller than the inner diameter of the fixing hole. In the mold closed state, the left half of the insert and the right half of the insert are located inside the fixing hole. In the mold open state, the first tube surface, the second tube surface, the first reset surface, and the second reset surface are located outside the fixing hole.

2. The strong demolding structure of a mold according to claim 1, characterized in that, The top of the intermediate insert has a first cup head. A first wire spring is positioned in the A plate of the mold. The intermediate insert passes through the first wire spring. When the mold is in the closed state, the reset pin on the sprue push plate of the mold presses against the first cup head, causing the first cup head to compress the first wire spring. When the mold is opened, the mold first separates the sprue push plate and the A plate, causing the reset pin to disengage from the intermediate insert. The first wire spring causes the intermediate insert to disengage from the columnar component of the product.

3. The strong demolding structure of a mold according to claim 1, characterized in that, The top of the right half insert has a second cup head, and a second wire spring is limited in the fixing hole. When the mold is opened, the columnar part of the product pulls the insert, causing the second cup head to compress the second wire spring.

4. The strong demolding structure of a mold according to claim 1, characterized in that, The protruding length of the undercut surface of the columnar component of the product is less than the travel distance of the first guide surface when it moves radially.

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