Forming injection mold for preshrinking optical thick-wall part
By using a pre-shrinking injection mold for optical thick-walled parts, and utilizing a thickness adjustment insert and a slanted sliding block design, the problems of shrinkage, discoloration, and uneven wall thickness in the molding process of optical thick-walled parts were solved, achieving efficient two-color injection molding and improving product quality and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-03-24
AI Technical Summary
Thick-walled optical components are prone to shrinkage cavities, discoloration, shrinkage deformation, and uneven wall thickness distribution during the molding process, resulting in long molding cycles and substandard product quality, which are difficult to effectively solve with existing technologies.
An injection mold for pre-shrinking optical thick-walled parts is adopted. Through the combination design of thickness adjustment inserts and inclined sliding blocks, the wall thickness adjustment and pre-shrinking of the cavity of the first color semi-finished product are realized. Combined with the wall thickness supplementation of the cavity of the second color finished product, the two-color injection molding process of optical thick-walled parts is optimized.
It improves the molding quality and efficiency of thick-walled optical components, shortens the molding cycle, avoids the problem of plastic yellowing, and increases the product qualification rate and production efficiency.
Smart Images
Figure CN224028239U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to optical thick -walled piece production technical field especially, and it is a kind of optical thick -walled piece pre-shrinking forming injection mold. BACKGROUND
[0002] General optical piece usually adopts single color injection molding, but for thick-walled optical piece, production forming cycle is long and is prone to shrinkage hole, discoloration and shrinkage deformation forming defects, therefore, for the production of optical thick -walled piece, two-color injection molding process can be considered.
[0003] In the field of two-color injection molding, the product of equal wall thickness is more conducive to injection molding and production, but due to part of product is generally L-shaped, the wall thickness in the middle reaches 25mm, and the thinnest part is only 4mm, due to the large difference in wall thickness, it is difficult to choose the appropriate wall thickness for single-color injection molding, and if the wall thickness is not accurately selected, the overall structure of the product may be deformed during the product shrinkage and warping process, and the product cannot pass the optical verification.
[0004] In addition, for the optical thick -walled piece with the above wall thickness of 25mm, if one-time integral injection molding is adopted, the mold needs to be pressure-kept and cooled sufficiently before opening, and the entire forming cycle is about 600 seconds, which is too long, reduces the production efficiency, and easily leads to uneven distribution of product wall thickness. During the one-time forming of the optical thick -walled piece, when the thin wall is filled and gradually solidified, the thick wall position of the product center is still in a molten state, and during the solidification process, the high molecular chain continuously shrinks and cannot obtain new material to fill in as compensation, at this time, the nearby molecular chain will be pulled, and finally a vacuum appears in the center of the product, forming a bubble defect, which leads to product defects and unqualified light distribution.
[0005] In addition, the one-time integral injection molding production of the optical thick -walled piece consumes such a long forming cycle, and the transparent plastic remaining in the screw of the injection molding machine is prone to yellowing or even carbonization and scorching due to the long plasticizing time, which leads to discontinuous normal production and needs to be improved. UTILITY MODEL CONTENTS
[0006] The utility model mainly solves the technical problem to provide a kind of optical thick -walled piece pre-shrinking forming injection mold, it is convenient to adjust and optimize pre-shrinking of the wall thickness of the first color semi-finished product cavity, improve the two-color injection molding quality and efficiency of optical thick -walled piece.
[0007] To solve the above technical problems, one technical scheme of the utility model is: provide a kind of optical thick-walled piece pre-shrinking's forming injection mold, for the injection molding of optical thick-walled piece, comprising: front mould assembly and corresponding rear mould assembly, the rear mould assembly includes rear template, first rear module and second rear module, the first rear module and second rear module are symmetrically arranged on rear template, the front mould assembly includes front template, oblique extraction slide block, thickness adjustment insert, first front module and second front module, the first front module is set on front template and corresponds with first rear module, the thickness adjustment insert is detachably set on front template and is located first front module side, after the closing of front mould assembly and rear mould assembly, first color semi-finished product cavity corresponding with optical thick-walled piece is enclosed by thickness adjustment insert, first front module and first rear module, the second front module is set on front template and corresponds with second rear module, the oblique extraction slide block is obliquely placed in front template, and front end extends into second front module, embedded groove corresponding with the front end of oblique extraction slide block and pointing to second rear module is provided in second front module, after the closing of front mould assembly and rear mould assembly, second color finished product cavity corresponding with optical thick-walled piece is enclosed by second front module, oblique extraction slide block and second rear module.
[0008] In a preferred embodiment of the utility model, the rear template is concave and has a first positioning groove corresponding to the first rear module and the second rear module, and the first rear module and the second rear module are arranged in the corresponding first positioning grooves.
[0009] In a preferred embodiment of the utility model, the front template is concave and has a second positioning groove corresponding to the first front module and the thickness adjustment insert, and the first front module and the thickness adjustment insert are arranged in the second positioning groove.
[0010] In a preferred embodiment of the utility model, the front template is concave and has a third positioning groove corresponding to the second front module, and the second front module is arranged in the corresponding third positioning groove.
[0011] In a preferred embodiment of the utility model, the thickness adjustment insert is provided with a fastening screw connected to the front template.
[0012] In a preferred embodiment of the utility model, the optical thick-walled piece includes a vehicle lamp reflector.
[0013] In a preferred embodiment of the utility model, the thickness of the second color finished product cavity in the direction towards the oblique extraction slide block is greater than the thickness of the first color semi-finished product cavity in the direction towards the thickness adjustment insert.
[0014] In a preferred embodiment of the utility model, the front template is provided with a guide inclined groove corresponding to the oblique extraction slide block.
[0015] In a preferred embodiment of the utility model, the front template one side is provided with the oil cylinder, the oil cylinder end is provided with the slider spade base connected with the inclined extraction slider.
[0016] In a preferred embodiment of the utility model, after the rear mold assembly 180° rotation, the position switching of the first rear module and the second rear module is carried out.
[0017] The utility model discloses a kind of optical thick-walled piece pre-shrinking forming injection mould, by the replacement of thickness adjustment insert, first color semi-finished product cavity can be quickly adjusted at wall thickness, increase or reduce the wall thickness of first color semi-finished product cavity, optimize pre-shrinking problem, then realize the complement of wall thickness by second color finished product cavity, it is favorable to improve the two-color injection molding quality and pass rate of optical thick-walled piece, and can greatly shorten forming cycle, improve injection molding efficiency, avoid the problem that plastic is yellow due to plasticizing time being too long. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed to be used in the embodiment description will be simply introduced as follows, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor, wherein:
[0019] Figure 1 It is a structure schematic view of a preferred embodiment of the utility model one optical thick-walled piece pre-shrinking forming injection mould;
[0020] Figure 2 It is Figure 1 structure schematic view of rear mold assembly. DETAILED DESCRIPTION
[0021] The technical scheme in the embodiment of the utility model will be clearly and completely described as follows, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.
[0022] Please refer to Figures 1-2 , the utility model embodiment includes:
[0023] As Figure 1 Indicated, optical thick-walled piece pre-shrinking forming injection mould is used for the injection molding of optical thick-walled piece, taking the car lamp reflector of substantially L type as an example, the wall thickness of the middle of car lamp reflector reaches 25mm, and the thinnest place is only 4mm.
[0024] The forming injection mold comprises a front mold assembly 100 and a corresponding rear mold assembly 200, the rear mold assembly 200 comprising a rear mold plate 201, a first rear mold block 202 and a second rear mold block 203, as shown, the first rear mold block 202 and the second rear mold block 203 are symmetrically arranged on the rear mold plate 201, the rear mold plate 201 is concavely arranged with a first positioning groove 204 corresponding to the first rear mold block 202 and the second rear mold block 203, and the first rear mold block 202 and the second rear mold block 203 are arranged in the corresponding first positioning groove 204 respectively, which is convenient for assembly and accurate positioning. Figure 2
[0025] The wall thickness in the middle reaches 25mm, and the thinnest part is only 4mm,
[0026] In addition, the first rear mold block 202 and the second rear mold block 203 can be fixed in the first positioning groove 204 by screws, which is convenient for disassembly and assembly. After the mold is opened, the rear mold assembly 180° rotates, and the position switching of the first rear mold block 202 and the second rear mold block 203 can be performed.
[0027] The front mold assembly 100 comprises a front mold plate 101, an inclined pulling slider 110, a thickness adjusting insert 103, a first front mold block 102 and a second front mold block 106, and in addition, as shown, the rear mold assembly 200 further comprises a bottom plate and a ejector plate, and the front mold assembly 100 further comprises a face plate and a hot runner plate, which are not described here. Figure 1 The first front mold block 102 is arranged on the front mold plate 101 and corresponds to the first rear mold block 202, the thickness adjusting insert 103 is arranged on the front mold plate 101 and located on one side of the first front mold block 102, and in this embodiment, the front mold plate 101 is concavely arranged with a second positioning groove 104 corresponding to the first front mold block 102 and the thickness adjusting insert 103, and the first front mold block 102 and the thickness adjusting insert 103 are arranged in the second positioning groove 104 together, which has high positioning accuracy, and the thickness adjusting insert 103 is arranged with a fastening screw 105 connected with the front mold plate 101, which is convenient to replace.
[0028] After the front mold assembly 100 and the rear mold assembly 200 are closed, a first color semi-finished product cavity 1 corresponding to the optical thick-walled part is formed by the thickness adjusting insert 103, the first front mold block 102 and the first rear mold block 203, and in the trial production process by using an injection molding machine, the adjustment of the first color semi-finished product cavity 1 at the wall thickness can be quickly performed by replacing the thickness adjusting insert 103 of different sizes, the maximum wall thickness of the first color semi-finished product cavity can be increased or reduced, especially the adjustment of the maximum wall thickness part, which optimizes the pre-shrinkage problem and determines the most suitable thickness adjusting insert 103 in size.
[0029]
[0030] The second front module 106 is set on the front template 101 and corresponds to the second rear module 203. In this embodiment, the front template 101 is recessed and a third positioning groove 112 corresponding to the second front module 106 is provided. The second front module 106 is set in the corresponding third positioning groove 112 and can be fixed with screws, so the structure is stable.
[0031] like Figure 1 As shown, the inclined sliding block 110 is placed obliquely in the front template 101, and its front end extends into the second front module 106. The second front module 106 is provided with an embedding groove 107 corresponding to the front end of the inclined sliding block 110 and pointing to the second rear module 203. In addition, the front template 101 is provided with a guide groove 108 corresponding to the inclined sliding block 110 for sliding guidance of the inclined sliding block 110.
[0032] In order to drive the inclined sliding block 110, a hydraulic cylinder 111 is provided on one side of the front template 101. The end of the hydraulic cylinder 111 is provided with a sliding block base 109 connected to the inclined sliding block 110. The extension and retraction of the hydraulic cylinder 111 indirectly drives the inclined sliding block 110 to move forward and backward.
[0033] After the front mold assembly 100 and the rear mold assembly 200 are closed, the second front module 106, the inclined sliding block 110, and the second rear module 203 form a second-color finished product cavity 2 corresponding to the optical thick-walled part. The thickness of the second-color finished product cavity 2 in the direction towards the inclined sliding block 110 is greater than the thickness of the first-color semi-finished product cavity 1 in the direction towards the thickness adjustment insert 103. The wall thickness is supplemented by the second-color finished product cavity 2 (the thickest part of the first-color semi-finished product cavity 1 is 20mm, and the wall thickness is supplemented by 5mm by the second-color finished product cavity 2). This is beneficial to improving the two-color injection molding quality and pass rate of the optical thick-walled part, shortening the molding cycle, and improving the injection molding efficiency.
[0034] After mold closing, the first injection molding is performed through the first color semi-finished product cavity 1 to form the optical thick-walled part semi-finished product (the thickest part of the first color semi-finished product cavity 1 is 20mm). The injection molding machine fills the material flow, the mold holds pressure and cools, and then the mold opens. The rear mold assembly 200 rotates 180° and then closes the mold. The second injection molding is performed using the second color finished product cavity 2 to achieve the 5mm wall thickness supplement. The injection molding machine fills the material flow, the mold holds pressure and cools, and then the mold opens to eject the optical thick-walled part. The first injection molding and the second injection molding constitute a complete molding cycle. The entire molding cycle is controlled within 150 seconds, which is much less than the previous 600 seconds.
[0035] In summary, the pre-shrinking injection mold for optical thick-walled parts disclosed in this utility model solves the difficulties in the molding process of optical thick-walled parts, optimizes the pre-shrinking problem, and improves the quality and efficiency of injection molding production of optical thick-walled parts.
[0036] The above are only embodiments of the present application, and do not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A pre-shrinking injection mold for optical thick-walled components, used for injection molding of optical thick-walled components, characterized in that, include: The front mold assembly and the corresponding rear mold assembly are provided. The rear mold assembly includes a rear template, a first rear module, and a second rear module. The first rear module and the second rear module are symmetrically arranged on the rear template. The front mold assembly includes a front template, a slanted sliding block, a thickness adjustment insert, a first front module, and a second front module. The first front module is arranged on the front template and corresponds to the first rear module. The thickness adjustment insert is detachably arranged on the front template and located on one side of the first front module. After the front mold assembly and the rear mold assembly are molded together, the thickness adjustment insert, the first front module, and the first rear module form a first-color semi-finished product cavity corresponding to the optical thick-walled part. The second front module is arranged on the front template and corresponds to the second rear module. The slanted sliding block is slantedly placed in the front template and its front end extends into the second front module. The second front module is provided with an embedding groove corresponding to the front end of the slanted sliding block and pointing to the second rear module. After the front mold assembly and the rear mold assembly are molded together, the second front module, the slanted sliding block, and the second rear module form a second-color finished product cavity corresponding to the optical thick-walled part.
2. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The rear template has a recessed first positioning groove that corresponds one-to-one with the first rear module and the second rear module, and the first rear module and the second rear module are respectively set in the corresponding first positioning groove.
3. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The front template has a recessed second positioning groove corresponding to the first front module and the thickness adjustment insert, and the first front module and the thickness adjustment insert are disposed in the second positioning groove.
4. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The front template has a recessed third positioning groove corresponding to the second front module, and the second front module is disposed in the corresponding third positioning groove.
5. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The thickness adjustment insert is equipped with fastening screws that connect to the front template.
6. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The optical thick-walled component includes a vehicle headlight reflector.
7. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The thickness of the second-color finished product cavity in the direction toward the inclined sliding block is greater than the thickness of the first-color semi-finished product cavity in the direction toward the thickness adjustment insert.
8. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, The front template is provided with a guide groove corresponding to the inclined sliding block.
9. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, A hydraulic cylinder is provided on one side of the front template, and a slider shovel base connected to the inclined slider is provided at the end of the hydraulic cylinder.
10. The injection mold for pre-shrinking optical thick-walled parts according to claim 1, characterized in that, After the rear module assembly rotates 180°, the positions of the first rear module and the second rear module are switched.