A fixing jig for processing an injection mold core

Abstract

The utility model discloses a kind of for processing injection mold core's fixed jig, including a jig body, its upper portion and / or lower portion is evenly provided with multiple inlay holes with prismatic core unit main body contour adaptation;The hole bottom plane of the inlay hole and the datum plane of jig body form a preset angle, and the upper end of each inlay hole is evenly provided with a notch. When using, multiple core units are placed in inlay hole one-time, and the slanted surface structure of hole bottom realizes batch, unified angle positioning, and the longitudinal edge to be processed is exposed through the notch of upper end. The utility model successfully transforms the traditional complex single-piece angle alignment into simple, efficient batch surface grinding, greatly improves production efficiency and product consistency, and significantly reduces the skill requirement to operator.

Description

[Technical Field] This utility model relates to the field of injection mold processing equipment technology, and in particular to a fixing fixture for processing injection mold cores. [Background Technology] In the fields of modern semiconductor packaging and optoelectronic device manufacturing, such as the production of high-precision plastic products like LED chip brackets, precision injection molding technology is widely relied upon. The mold structure for these products is extremely complex, typically featuring a core sleeve in the rear mold core. This sleeve contains dozens or even hundreds of independent mold core units arranged in an array to mold the product details.

[0001] In the high-temperature, high-pressure injection molding process, to ensure that the molten plastic can smoothly and completely fill every tiny corner of the mold, and at the same time quickly expel the gas generated by the plastic extrusion within the mold cavity, an effective venting structure must be installed in the mold. Poor venting is a major cause of molding defects such as overflow, missing cups, air marks, and scorching. In this technical field, a mature and widely adopted solution is to form a tiny air-entraining groove between each individual mold core unit and the inner wall of the nesting hole of the mold core sleeve, utilizing the fitting clearance. The formation of this air-entraining groove relies on the precision grinding of a specific side angle of each mold core unit during the mold manufacturing stage to form a side edge with extremely high requirements for size and angle.

[0002] However, the current processing methods for this side edge have significant drawbacks. Currently, the industry generally relies on general-purpose but complex tools such as sinusoidal magnetic tables to perform tedious angle alignment and positioning of individual core units, followed by single-piece grinding, a process that is repeated endlessly. This traditional single-piece processing mode firstly leads to extremely low production efficiency, severely restricting the manufacturing and maintenance cycle of molds; secondly, this method is highly dependent on the personal experience of the operators, making standardization difficult and resulting in high labor costs; more importantly, because unavoidable minor errors exist in each manual clamping, the consistency of cores produced in batches is difficult to guarantee, ultimately affecting the overall performance of the mold and the yield rate of the products. [Utility Model Content] The purpose of this utility model is to provide a fixing fixture for processing injection mold cores, which aims to solve the problems of low processing efficiency, poor product consistency, and excessively high skill requirements for operators caused by relying on manual single-piece alignment and positioning in the prior art.

[0003] This utility model is achieved through the following technical solution: A fixture for processing injection mold cores includes a fixture body capable of fixing multiple core units. The main body of each core unit is a polygonal prism with a boss on one side. The upper and / or lower parts of the fixture body are uniformly provided with multiple inlay holes that conform to the outline of the main body of the core unit. The bottom plane of the inlay hole forms a preset angle α with the reference plane of the fixture body. The upper end of each inlay hole is provided with a notch for exposing the longitudinal edge of the core unit for grinding.

[0004] The fixture for processing injection mold cores as described above has a cuboid body, and one side wall of the fixture perpendicular to the depth direction of the insert hole can abut against the boss of the core unit to axially position the core unit.

[0005] As described above, the fixture for processing injection mold cores has a fitting clearance L between the inner wall of the inlay hole and the outer wall of the main body of the core unit, and the fitting clearance L is less than or equal to 0.005 mm.

[0006] The fixture for processing injection mold cores as described above, wherein the preset angle α satisfies the relationship: 30°≤α≤60°.

[0007] The pre-set angle α of the fixture used for processing injection mold cores as described above is 45°.

[0008] The fixture for processing injection mold cores as described above has 20-30 inlay holes.

[0009] As described above, in the fixture for processing injection mold cores, a plurality of the insert holes are arranged parallel to each other along the length of the fixture body.

[0010] As described above, in the fixture for processing injection mold cores, the inlay hole is a through hole that runs through the width direction of the fixture body.

[0011] The fixture for processing injection mold cores as described above is made of tool steel with magnetic conductivity and a hardness of HRC59-62.

[0012] Compared with the prior art, the present invention has the following advantages: 1. This utility model, by setting multiple inlay holes, enables the clamping and positioning of dozens of core units at one time, transforming the traditional single-piece processing mode into a batch processing mode. It eliminates the tedious step of independently aligning each core unit, significantly shortening auxiliary time and multiplying overall processing efficiency, effectively reducing the manufacturing and maintenance cycle of precision molds.

[0013] 2. This invention ensures that each processed core unit is positioned under the exact same datum by fixing the processing angle α to the bottom of the inlay hole in the fixture body. All cores can be processed in a single clamping operation through a single surface grinding, fundamentally eliminating the problem of inconsistent angles and dimensions of finished products caused by human error during traditional manual alignment of single parts. This effectively guarantees the overall performance of the final mold and the yield rate of injection molded products.

[0014] 3. This invention cleverly transforms the complex problem of angle positioning into a simple "placement-tightening" two-dimensional planar operation. Operators no longer need to rely on complex instruments such as sine magnetic tables or personal experience for difficult angle settings; they only need to place the core into the hole and use the guide gauge for simple linear reciprocating motion to complete high-precision machining. This greatly lowers the operational threshold, allowing ordinary technicians to perform tasks that previously required experienced technicians, effectively reducing labor costs. [Attached Image Description] To more clearly illustrate the technical solutions in the embodiments of the utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0015] Figure 1 This is a three-dimensional schematic diagram of the fixture body in this embodiment; Figure 2 This is a front view of the fixture body in this embodiment; Figure 3 This is a three-dimensional schematic diagram of the jig body and multiple core units in the assembled state in this embodiment. Figure 1 ; Figure 4 This is a three-dimensional schematic diagram of the jig body and multiple core units in the assembled state in this embodiment. Figure 2 ; Figure 5 This is a front view schematic diagram of the jig body and multiple core units in the assembled state in this embodiment; Figure 6 This is an exploded view of the assembly of the fixture body and multiple core units in this embodiment; Figure 7 A three-dimensional schematic diagram of a possible core unit before grinding. Figure 8 A three-dimensional schematic diagram of a possible core unit after grinding. Figure 9 This is a partial reference diagram showing the completed assembly of the core unit and the mold core sleeve through the nested hole.

Detailed Implementation Methods

[0016] Please see the appendix Figures 1 to 9 The core component of the fixing fixture in this embodiment is a fixture body 2. Before delving into the structure and function of this fixture, it is necessary to explain the specific technical background to which it is applied. In the field of modern semiconductor packaging, such as the precision injection molding process of LED chip brackets, the mold structure typically includes a rear mold core. Inside the rear mold core is a mold core sleeve, on which multiple high-precision nesting holes are formed in a rectangular array to install and position multiple independent mold core units 1.

[0017] In the injection molding process, to ensure that the molten plastic completely fills the mold cavity and to avoid molding defects such as overflow and missing cups caused by the inability of gas to escape smoothly, tiny venting channels must be set at the parting surface of the mold or the mating points of the insert components. In this technical field, a mature solution is to pre-form a tiny venting groove 3 between each mold core unit 1 and the inner wall of the nesting hole of the mold core sleeve. The formation of this venting groove 3 relies on the precise grinding of one side corner of each mold core unit 1 before it is inserted into the sleeve, forming a specific side ridge.

[0018] Therefore, the mold core unit 1 to be fixed in this embodiment is the core working part constituting the aforementioned precision injection mold. The fixing fixture proposed in this embodiment is precisely to solve the pain points of the prior art in processing the side edges of the core unit 1, which involves cumbersome procedures, reliance on manual skills, low single-piece processing efficiency, and difficulty in ensuring product consistency. The main body of the mold core unit 1 is typically a prism with a polygonal cross-section, such as a square or hexagonal prism, and an integrally formed boss 11 is provided on one side of its main body. This boss 11 is used for positioning during the final mold assembly.

[0019] Specifically, in this embodiment, a plurality of inlay holes 21 are evenly provided on the upper part of the fixture body 2. The internal contour of these inlay holes 21 is adapted to the main contour of the mold core unit 1 to facilitate the stable insertion of the core unit 1. As a more preferred embodiment aimed at further improving operational convenience and economy, the inlay holes 21 can also be symmetrically arranged on the lower part of the fixture body 2, that is, inlay holes with the same structure are provided on both the upper and lower parts of the fixture body 2. This double-sided symmetrical design allows the fixture to be used in both directions, greatly improving the operational error tolerance on the production line; more importantly, when one side of the fixture's working surface or guide surface is worn due to long-term use, the operator can directly rotate it 180° to use a brand new, intact working surface, thereby doubling the overall service life of the fixture.

[0020] Regardless of whether the mounting holes 21 are single-sided or double-sided, the core concept is that the bottom plane of each mounting hole 21 is not parallel to the reference plane of the fixture body 2, such as its bottom surface, but forms a preset angle α with it. In addition, in order to realize the processing of specific edges of the core unit 1, a notch 211 is specially opened at the opening end of each mounting hole 21.

[0021] Based on this structure, when the mold core unit 1 is inserted into the insert hole 21, it will naturally rest against the inclined bottom plane of the hole due to gravity, so that the main axis of the entire core unit 1 and the normal of the reference surface of the fixture body 2 form a precise preset angle α. At this time, the notch 211 located at the opening end can just expose a longitudinal edge of the core unit 1 that needs to be machined, so that the subsequent surface grinding equipment can directly contact and machine the edge.

[0022] Furthermore, as a preferred embodiment, the fixture body 2 is a precise hexagonal cuboid structure. One sidewall perpendicular to the depth direction of the insert hole 21 is designed as a flat reference surface, which can stably abut against the boss 11 of the core unit 1. When multiple core units 1 are installed into the fixture, their respective bosses 11 abut against this sidewall, thereby ensuring that all core units 1 have a uniform and precise positioning reference in the axial direction of the insert hole 21. This is crucial for ensuring the high dimensional consistency of all finished products after batch processing.

[0023] Furthermore, as an optional implementation, the plurality of the inlay holes 21 are arranged parallel to each other along the length direction of the fixture body 2. This linear array layout perfectly matches the reciprocating motion trajectory of the surface grinder table, which is beneficial for achieving an efficient and uniform grinding arrangement.

[0024] Furthermore, to achieve greater operational flexibility and a longer service life, the inlay hole 21 is designed as a through hole that runs through the width direction of the fixture body 2. This means that not only can the upper and lower surfaces of the fixture be used interchangeably, but its front and rear guide surfaces can also be used interchangeably, further enhancing the durability and economy of the fixture.

[0025] To ensure high stability and reliability of the invention during high-speed grinding, the inner wall of the insert hole 21 and the outer wall of the core unit 1 are designed to have extremely high fitting precision. Specifically, the fitting gap L between them is strictly controlled within a tolerance range of less than or equal to 0.005 mm. This fitting gap L can be achieved through a high-precision wire EDM process. This process ensures that the inner wall of the insert hole 21 has extremely high dimensional accuracy, contour accuracy, and surface finish, thus forming a near-seamless fit with the outer wall of the core unit 1, which has also undergone precision grinding.

[0026] The precise control of the clearance L is designed to effectively resist and absorb the cutting forces generated during grinding. When the high-speed rotating grinding wheel contacts the longitudinal edge of the core unit 1, a lateral force perpendicular to the feed direction is generated. Because of the large-area, uniform, and almost gapless contact between the inner wall of the insert hole 21 and the main body of the core unit 1, this lateral force is quickly transmitted and dispersed onto the highly rigid fixture body 2. This completely eliminates any slight deflection, wobbling, or vibration of the core unit 1 within the insert hole 21, thus ensuring that the machining angle set by the inclined plane at the bottom of the hole remains precisely constant throughout the entire dynamic machining process.

[0027] Furthermore, the preset angle α of the bottom plane of the inlay hole 21 is a core geometric parameter for achieving precise machining. The selection of its value directly determines the precise shape and size of the side edge formed on the mold core unit 1, and thus affects the final performance of the core unit 1 in actual injection molding production. In the field of precision injection mold design, the cross-sectional dimensions of the air-guiding and venting groove formed by the side edge of the core unit 1 and the inner wall of the mold core sleeve must be strictly controlled. If the groove is too small, the gas in the mold cavity cannot be effectively discharged during high-speed injection molding, which can easily lead to molding defects such as missing cups or air marks; conversely, if the groove is too large, molten plastic may enter the groove and form overflow, affecting product accuracy. At the same time, an excessively large side edge will also unnecessarily weaken the structural strength of the corners of the core unit 1.

[0028] Therefore, the preset angle α is an optimized result obtained after comprehensively considering the above engineering constraints. In this embodiment, the angle satisfies the relationship: 30°≤α≤60°. This range ensures that, through subsequent surface grinding processes, an air-guiding side ridge with dimensions within the general process window can be formed on the core unit 1.

[0029] Furthermore, as a preferred embodiment, the preset angle α is set to 45°. Choosing a 45° angle has several technical advantages: First, it allows for the formation of an air intake channel with the largest effective cross-sectional area while removing minimal material, achieving a balance between exhaust efficiency and core structure strength; second, 45° is one of the most commonly used, easiest to inspect, and most accurate standard angles in machining, simplifying the manufacturing and inspection process of the fixture itself in this embodiment, and resulting in a clear and stable profile of the final ground side edge.

[0030] Furthermore, in order to achieve efficient mass production, the number of the inlay holes 21 is usually set to 20 to 30. This number ensures the processing volume per batch while keeping the size and weight of the fixture body 2 within a reasonable range that facilitates manual operation.

[0031] To ensure the durability and ease of use of this invention, the material of the fixture body 2 has been specially selected. In a preferred embodiment, the fixture body 2 is made of magnetic tool steel, such as SKD-11 grade cold work die steel from the Japanese Industrial Standard, and undergoes a precision vacuum heat treatment process to achieve an overall hardness of HRC59-62. The use of magnetic tool steel allows the fixture to be directly placed on the electromagnetic chuck of a surface grinder, enabling quick and secure clamping; while the high hardness of HRC59-62 ensures the fixture has extremely high wear resistance, maintaining its machining accuracy over a long period.

[0032] To further illustrate the application of the fixing fixture proposed in the embodiments in actual engineering, a typical use case will be described below: Before processing, the operator first securely fixes a guide block with a straight guide surface on the worktable of the surface grinder, such as an electromagnetic chuck. Then, the operator inserts multiple mold core units 1 to be processed one by one into the inlay holes 21 of the fixing fixture of the present invention. During insertion, the boss 11 of the core unit 1 abuts against the side wall of the fixture body 2, thereby achieving precise preliminary positioning in the axial direction.

[0033] Once all core units 1 are installed, the operator places the fixture body 2, which carries multiple core units 1, onto the electromagnetic chuck and activates the magnetism, using the fixture body 2's own magnetism to firmly attach it to the worktable. At this point, the operator positions the fixture body 2 so that its long side facing the protrusion 11 of the core unit 1 is close to the guide gauge, and ensures that the end face of each core unit 1 extending from the fixture body 2 is in close contact with the guide surface of the guide gauge.

[0034] After the grinding process begins, the operator manually applies a continuous thrust parallel to the rotation axis of the grinding wheel, and simultaneously applies a lateral pressure to keep the fixture body 2 in constant contact with the guide gauge. Driven by this dual force, the fixture body 2 performs a stable and precise reciprocating linear motion along the guide surface of the guide gauge under the high-speed rotating grinding wheel. Since all core units 1 are tilted and positioned by the fixture body 2 at a fixed preset angle α, and the longitudinal edges to be machined are exposed through the notch 211, the surface grinding motion of the grinding wheel can simultaneously machine air-drawing side edges with consistent angle and dimension on all core units 1 in a single setup.

[0035] The entire process successfully transforms the traditional complex procedure of relying on precision instruments for single-piece angle alignment into a highly efficient and reliable manual batch processing flow guided by simple tooling, which greatly improves production efficiency and ensures the stability of product quality.

[0036] The above are implementation methods provided in conjunction with specific content, and it is not intended that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. A fixture for processing injection mold cores, comprising a fixture body (2) for fixing multiple core units (1), wherein the main body of the core unit (1) is a polygonal prism with a boss (11) on one side, characterized in that, The upper and / or lower parts of the fixture body (2) are evenly provided with a plurality of inlay holes (21) that are adapted to the main body contour of the core unit (1). The bottom plane of the inlay hole (21) forms a preset angle α with the reference plane of the fixture body (2). Each inlay hole (21) has a notch (211) at its upper end for the longitudinal edge of the core unit (1) to be exposed for grinding.

2. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The fixture body (2) has a cuboid structure, and one side wall of it perpendicular to the depth direction of the inlay hole (21) can abut against the boss (11) of the core unit (1) to axially position the core unit (1).

3. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The inner wall of the inlay hole (21) and the outer wall of the main body of the core unit (1) have a fitting gap L, which is less than or equal to 0.005 mm.

4. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The preset angle α satisfies the relationship: 30°≤α≤60°.

5. The fixing fixture for processing injection mold cores according to claim 4, characterized in that, The preset angle α is 45°.

6. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The number of the inlay holes (21) is 20-30.

7. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The plurality of the inlay holes (21) are arranged parallel to each other along the length direction of the fixture body (2).

8. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The inlay hole (21) is a through hole that runs through the width direction of the fixture body (2).

9. The fixing fixture for processing injection mold cores according to claim 1, characterized in that, The fixture body (2) is made of magnetic tool steel with a hardness of HRC59-62.

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