Embedded type cavity polishing jig and manufacturing method

Abstract

The invention relates to the technical field of polishing jigs, in particular to an embedded type cavity polishing jig and a manufacturing method. In the industry, CNC carving is adopted for producing a polishing jig, burrs and knife patterns are prone to being generated and need to be removed through manual grinding, and the machining efficiency is low; a fiber rubber plate is generally adopted as a polishing jig, the rigidity is too high, the flexibility is insufficient, and when brittle materials are polished, the defects of edge breakage, scratches, edge raised grains and the like are prone to occurring. According to the embedded type cavity polishing jig and the manufacturing method, the jig base plate is manufactured through the punch forming process, burrs and knife lines are avoided, manual grinding is not needed, and the machining efficiency is improved. The jig base plate is provided with the cavity, the flexible inlay strip is tightly attached to the inner wall of the cavity, and the flexible inlay strip can absorb collision energy during polishing, so that the defects of edge breakage, scratching, edge raised grains and the like of the polishing piece made of the fragile material are reduced, and the yield of the polishing piece is increased.

Description

Technical Field

[0001] This invention relates to the field of polishing fixture technology, and in particular to an inlaid cavity polishing fixture and its manufacturing method. Background Technology

[0002] In fields such as optics and electronics, the application of brittle materials (such as glass, ceramics, and sapphire) is becoming increasingly widespread. The surface polishing precision of these materials directly affects the final performance of the product. To ensure stable product positioning during polishing and avoid a decrease in polishing precision due to displacement, specialized polishing fixtures are typically used to fix the product in place. Currently, most mainstream polishing fixtures for brittle materials in the industry employ CNC engraving. These fixtures use fiberglass sheets as the base material and utilize CNC subtractive machining technology to directly engrave cavities for product positioning and slots for auxiliary fixation onto the base material. While this processing method can achieve integrated molding of the cavity and slots, meeting the basic requirements for product positioning to a certain extent, it still reveals many intractable defects in actual production applications, as follows: 1. Low processing efficiency, unable to meet mass production needs: CNC subtractive machining requires carving along the contour of the cavity and slot with a cutting tool, resulting in a long processing path. Taking a standard-sized polishing fixture for brittle materials as an example, the carving of the cavity and slot of a single fixture can typically take several hours. This long processing cycle makes it difficult to meet the industry's demand for mass production of polishing fixtures for brittle materials, severely restricting the production efficiency of downstream brittle material products. 2. Poor processing quality, additional processes and costs: During CNC machining, unavoidable vibrations during machine operation and wear of cutting tools after prolonged use can easily generate numerous burrs and tool marks on the inner walls and edges of the carved cavity. If these burrs and tool marks are not treated, they can scratch the product surface or affect positioning accuracy during product positioning, thus requiring a manual grinding and cleaning process. Manual grinding not only requires additional labor costs but may also lead to deviations in cavity dimensional accuracy due to the subjectivity of the grinding operation, further affecting the positioning effect of the fixture and significantly increasing the overall production cost and processing cycle of the fixture. 3. Low product yield, resulting in material waste and economic losses: The fiberboard material used in the fixture substrate is inherently rigid and lacks flexibility. Brittle materials, while having high hardness, have poor impact resistance and are prone to chipping and scratches. During the placement of brittle materials into the fixture cavity and subsequent polishing, the product edges frequently collide or rub against the rigid inner wall of the cavity, easily leading to defects such as chipping, surface scratches, and edge ripples. This significantly reduces the yield of products made from brittle materials.

[0003] In summary, existing CNC-based polishing fixtures for fiberboard have significant shortcomings in terms of processing efficiency, processing quality, and product yield, making it difficult to meet the current demand for efficient, high-quality, and high-yield production in the field of brittle material processing. Therefore, there is an urgent need for a new type of polishing fixture for brittle materials that can solve the above problems. Summary of the Invention

[0004] Based on this, it is necessary to provide an inlaid cavity polishing fixture to address the above-mentioned shortcomings, comprising: a fixture base plate, at least one cavity is formed on the surface of the fixture base plate, the cavity penetrates the fixture base plate, and a flexible inlay strip is fixedly connected to the inner wall of the cavity in close contact, the flexible inlay strip enclosing to form a placement position.

[0005] Preferably, the inner wall of the cavity is recessed with at least one groove, and the surface of the flexible inlay strip opposite to the inner wall of the cavity is provided with a toothed strip that cooperates with the groove, and the number of toothed strips is the same as the number of grooves.

[0006] Preferably, when the number of grooves is at least two, the grooves are evenly spaced on the inner wall of the cavity.

[0007] Preferably, the groove is a trapezoidal groove with a narrow opening and a wide bottom, and the cross-section of the rack perpendicular to its extension direction is an inverted trapezoid.

[0008] Preferably, the fixture substrate is made of fiberboard, the flexible insert strip is made of elastic polymer material, and the interface between the inner wall of the cavity and the flexible insert strip has a molecular-level fusion of 2 mm.

[0009] Preferably, the fixture substrate has a recessed inlet that communicates with the cavity.

[0010] Preferably, the surface of the fixture substrate is provided with a plurality of overflow holes spaced evenly from each other, the overflow holes being used to allow excess polishing liquid to flow out during polishing.

[0011] The present invention also provides a method for manufacturing an inlaid cavity polishing fixture, which is used to manufacture the aforementioned inlaid cavity polishing fixture, specifically including the following steps: Step S1: Stamping of substrate. Place a standard-sized fiberboard under a stamping machine and stamp it in one go using a mold to obtain a fixture substrate with a cavity. Step S2: Injection molding of flexible insert strips, placing the fixture substrate in the injection mold; Step S21: Material pretreatment, drying the elastic polymer material particles at 60℃-120℃ for 50min-90min; Step S22: Heating and melting, using segmented heating, the temperature is gradually increased from 180℃ to 250℃ to completely melt the elastic polymer material particles; Step S23: Mold closing, performed at three speeds (25%, 35%, 30%). Step S24, at 245℃-260℃ and 1450kgf / cm² 2 ±300kgf / cm 2 Under high pressure, molten elastic polymer material particles are injected into the mold cavity, and the injection time is 6s±3s; Step S25: Pressure holding, using 160 kgf / cm² 2 ±20kgf / cm 2 The pressure is maintained at a rate of 15 mm / s ± 5 mm / s, and the holding time is < 0.3 s; Step S26: Use room temperature water cooling to shape the elastic polymer material. The cooling time is 13s ± 3s. Step S27: Mold opening, with three speeds (3%, 25%, 15%). Step S28: Demolding. Use ejector pins to eject the product. The ejection time is 1-3 seconds. Step S3, post-processing: Check for defects such as insufficient glue, burrs, and deformation, and polish the burrs to complete production.

[0012] The aforementioned inlaid cavity polishing fixture and its manufacturing method utilize a one-time stamping process to obtain the fixture substrate. The stamped fixture substrate is free of burrs and tool marks, eliminating the need for manual polishing and significantly reducing processing time and improving efficiency. An injection molding process is used to form a flexible inlay strip that tightly adheres to the inner wall of the cavity of the mold substrate. During polishing, the flexible inlay strip is used to fix the brittle material polishing part. This flexible inlay strip effectively absorbs vibrations generated during polishing, reducing defects such as chipping, scratches, and edge wavy lines in the brittle material polishing part, thus improving the yield rate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an inlaid cavity polishing fixture in one embodiment of the present invention; Figure 2 for Figure 1 An enlarged view of region A in the illustrated embodiment; Figure 3 This is a schematic diagram of the structure of an inlaid cavity polishing fixture in another embodiment of the present invention.

[0014] Explanation of reference numerals in the attached drawings: 100-Jig base plate, 100a-Cavity, 100b-Groove, 100c-Inlet, 100d-Overflow hole, 200-Flexible insert strip, 200a-Placement position, 210-Rack. Detailed Implementation

[0015] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0016] This invention discloses an inlaid cavity polishing fixture, such as Figure 1 , Figure 2 , Figure 3 As shown, the fixture includes: a fixture base plate 100, with an overflow hole 100d and at least one cavity 100a on its surface. The overflow hole 100d allows excess polishing liquid to flow out during polishing. The cavity 100a extends through both sides of the fixture base plate 100, allowing the polishing fixture to simultaneously polish both sides of the workpiece, significantly reducing polishing time. A flexible insert strip 200 is tightly and fixedly connected to the inner wall of the cavity 100a, forming a placement position 200a for placing brittle material workpieces. During use, the brittle material workpiece is placed in the placement position 200a for polishing. The flexible insert strip 200, used to fix the brittle material workpiece, forms a flexible buffer zone on the rigid fixture base plate 100. When the brittle material workpiece is polished, the flexible insert strip 200 can absorb the impact energy of the workpiece edge, preventing direct contact between the brittle material workpiece and the fixture base plate 100, greatly reducing defects such as chipping, scratches, and edge wavy lines on the brittle material workpiece. Without the flexible insert strip 200 in the cavity 100a, the probability of defects in the polished part is: edge chipping 15%, scratches 5%, and edge wavy lines 10%. However, after polishing using the polishing fixture provided by this invention, the probability of defects in the polished part is significantly reduced: edge chipping <6%, scratches <3%, and edge wavy lines <1%. Furthermore, the fixture substrate 100 is formed by stamping, which, compared to CNC engraving, not only has a faster forming speed but also results in a smooth, burr-free inner wall of the cavity 100a of the stamped fixture substrate 100, eliminating the need for subsequent polishing and greatly shortening the production cycle. Existing polishing fixtures using CNC machining require 3000 seconds for 15-piece stacking and 600 seconds for single-piece machining. The fixture manufacturing method provided by this invention has a single-piece machining time of only 45 seconds.

[0017] It should be noted that the placement position 200a formed by the cavity 100a and the flexible inlay strip 200 on the fixture substrate 100 of the present invention can be adjusted in shape according to actual needs. In one embodiment, such as Figure 1 , Figure 2 As shown, the placement position 200a formed by the flexible inlay strip 200 is circular and is used for polishing watch crystals made of glass or other hard and brittle materials; in another embodiment, such as Figure 3 As shown, the placement position 200a formed by the flexible inlay strip 200 is a rounded rectangle, used for polishing glass or other hard and brittle materials for mobile phone screens or back covers, and can also be used for polishing glass or other hard and brittle materials for electronic product screens or back covers.

[0018] In one embodiment, such as Figure 1 , Figure 2 , Figure 3 As shown, the inner wall of the cavity 100a is recessed with multiple grooves 100b, which are evenly spaced from each other. The flexible insert strip 200 has multiple protruding teeth 210 on the side opposite to the inner wall of the cavity 100a. The teeth 210 can engage with the grooves 100b, and the number of teeth 210 and grooves 100b is the same. In this embodiment, the grooves 100b extend along the axial direction of the cavity 100a and are elongated. The teeth 210 on the flexible insert strip 200 engage and fix with the grooves 100b on the inner wall of the cavity 100a, preventing the flexible insert strip 210 from rotating with the brittle material polished part during polishing. This also increases the collision buffer space, further reducing defects such as chipping, scratches, and edge wavy lines in the brittle material polished part, thus improving the yield rate of the brittle material polished part. In other embodiments, the extension direction of the groove 100b can be arranged circumferentially along the inner wall of the cavity 100a, or inclined along the inner wall of the cavity 100a, or wavy along the inner wall of the cavity 100a.

[0019] In one embodiment, such as Figure 1 , Figure 2 , Figure 3 As shown, the groove 100b set on the inner wall of the cavity 100a is a trapezoidal groove with a narrow opening and a wide bottom. Correspondingly, the cross-section of the rack 210 perpendicular to its extension direction is an inverted trapezoid. The trapezoidal structure increases the contact area between the groove 100b and the rack 210, making the force more uniform and the energy transfer more consistent, further reducing the risk of defects such as chipping, scratches, and edge wavy lines in polished parts made of brittle materials.

[0020] In one embodiment, the fixture substrate 100 is made of fiber-reinforced plastic sheet, and the flexible insert strip 210 is made of elastic polymer material, such as polycarbonate, polypropylene, silicone, polyurethane, or rubber. Fiber-reinforced plastic sheet is a high-performance rigid material that ensures the dimensional accuracy of the cavity during stamping of the fixture substrate 100. Furthermore, the fiber-reinforced plastic sheet is not easily deformed over long-term use, providing long-term stable rigid support. In another embodiment, the flexible insert strip 210 is made of polycarbonate or polypropylene. Its unique flexibility meets the impact energy absorption requirements during polishing, preventing chipping and scratches on brittle polished parts. Simultaneously, polycarbonate or polypropylene is wear-resistant, resisting repeated friction during polishing, resulting in a longer lifespan compared to ordinary rubber insert strips and reducing the frequency of consumable replacement. Using injection molding, a 2mm molecular-level fusion is formed between the inner wall of the cavity 100a and the interface of the flexible insert strip 210. Compared with conventional mechanical bonding or adhesion, the bonding strength is increased by 3-5 times. This can completely eliminate the relative displacement between the insert strip and the cavity under high-frequency vibration during polishing, ensuring long-term stable positioning accuracy. At the same time, the molecular-level fusion eliminates any microscopic gaps at the interface. On the one hand, it allows the buffer energy to be evenly transferred to the fixture substrate 100 through the fusion layer, avoiding product defects caused by local energy concentration. On the other hand, it can prevent polishing debris and coolant from seeping into the interface, preventing corrosion of the interface or bonding failure due to impurity accumulation, and extending the overall service life of the polishing fixture.

[0021] In one embodiment, such as Figure 1 , Figure 2 , Figure 3 As shown, the surface of the fixture substrate 100 is recessed with an injection port 100c communicating with the cavity 100a for injection molding to form the flexible insert strip 210. The number of injection ports 100c depends on the length and shape of the flexible insert strip 210. In one embodiment, such as... Figure 1 , Figure 2 As shown, when polishing the watch crystal, two glue inlets 100c are provided at any position where one diameter of the circular cavity 100a intersects the arc; in another embodiment, as... Figure 3 As shown, when polishing the mobile phone screen glass and back cover glass, two glue inlets are set on the long side of the rectangular cavity 100a, and one glue inlet 100c is set on the short side of the rectangular cavity 100a, with adjacent glue inlets 100c evenly spaced from each other.

[0022] This invention also provides a method for manufacturing an inlaid cavity polishing fixture, which is used to manufacture an inlaid cavity polishing fixture with a substrate made of fiber optic sheet and flexible inlay strips made of polycarbonate or polypropylene, specifically including the following steps: Step S1: Stamping of substrate. Place a standard-sized fiberboard under a stamping machine and stamp it in one go using a mold to obtain a fixture substrate with overflow holes and cavities.

[0023] Step S2: Injection molding of flexible insert strips. Place the fixture substrate in the injection mold. In this embodiment, PC material (polycarbonate) is selected as the injection molding material. In another embodiment, PP material (polypropylene) is selected as the injection molding material. Step S21: Material pretreatment. The polycarbonate or polypropylene particles are dried at 60℃-120℃ for 50min-90min to remove moisture from the surface of the polycarbonate or polypropylene particles and prevent the polycarbonate or polypropylene from degrading in subsequent processes.

[0024] Step S22: Heating and melting. Segmented heating is used, with the temperature gradually increased from 180℃ to 250℃ to ensure that the polycarbonate or polypropylene particles are completely melted. This prevents the polycarbonate or polypropylene particles from sticking together and hindering the normal flow of the melted material particles or decomposing prematurely during the injection molding process due to uneven heating.

[0025] Step S23: Mold closing. The mold is closed at three speeds (25%, 35%, and 30%). The three speeds in this step are based on the maximum mold closing speed of the equipment used. That is, the first speed of 25% is 25% of the maximum mold closing speed of the equipment, the second speed of 35% is 35% of the maximum mold closing speed of the equipment, and the third speed of 30% is 30% of the maximum mold closing speed of the equipment, to ensure that the mold closes smoothly, at high speed, and with low-pressure protective closure.

[0026] Step S24, at 245℃-260℃ and 1450kgf / cm² 2 ±300kgf / cm 2 Under pressure, molten polycarbonate or polypropylene material is injected into the mold cavity. The injection time is 6s±3s. The injection temperature in this step is slightly higher than the melting temperature to ensure the fluidity of the molten polycarbonate or polypropylene.

[0027] Step S25: Pressure holding, using 160 kgf / cm² 2 ±20kgf / cm 2 The pressure is maintained at 15 mm / s ± 5 mm / s for a holding time of < 0.3 s to compensate for the shrinkage that occurs during the cooling and solidification of polycarbonate or polypropylene.

[0028] Step S26: Use room temperature water cooling to set the polycarbonate or polypropylene, with a cooling time of 13s ± 3s.

[0029] Step S27: Mold opening, with three speeds (3%, 25%, 15%). The three speeds in this step are based on the maximum mold closing speed of the equipment used. That is, the first speed of 3% is 3% of the maximum mold closing speed of the equipment, the second speed of 25% is 25% of the maximum mold closing speed of the equipment, and the third speed of 15% is 15% of the maximum mold closing speed of the equipment.

[0030] Step S28: Demolding. Use ejector pins to eject the product. The ejection time is 1-3 seconds.

[0031] Step S3, post-processing: Check for defects such as insufficient glue, burrs, and deformation, and polish the burrs to complete production.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An inlay cavity polishing fixture, characterized by, The utility model relates to a jig substrate (100) surface is provided with at least one cavity (100a), the cavity (100a) is through the jig substrate (100), the cavity (100a) inner wall closely fixedly connected with flexible inlay strip (200), and the flexible inlay strip (200) is enclosed and forms the placement site (200a). The cavity (100a) inner wall is recessed with at least one groove (100b), and the surface of the flexible inlay strip (200) opposite to the cavity (100a) inner wall is provided with a rack (210) matched with the groove (100b), and the number of the rack (210) and the groove (100b) is the same.

2. The inlay cavity polishing fixture of claim 1, wherein, When the number of the groove (100b) is at least two, the grooves (100b) are uniformly spaced on the cavity (100a) inner wall.

3. The tessellation cavity polishing fixture of claim 2, wherein, The groove (100b) is a trapezoidal groove with a narrow notch and a wide groove bottom, and the cross section of the rack (210) perpendicular to its extension direction is an inverted trapezoid.

4. The inlay cavity polishing fixture of claim 2, wherein, The jig substrate (100) is made of fiber glue board, the flexible inlay strip (200) is made of elastic polymer material, and the bonding surface of the cavity (100a) inner wall and the flexible inlay strip (200) has a molecular level fusion of 2 mm.

5. The tessellation cavity polishing fixture of claim 1, wherein, The jig substrate (100) is recessed with a glue inlet (100c) communicating with the cavity (100a).

6. The tessellation cavity polishing fixture of claim 1, wherein, The surface of the jig substrate (100) is also provided with a plurality of overflow holes (100d) uniformly spaced from each other, and the overflow holes (100d) are used to flow out the excess polishing liquid during polishing.

7. The tessellation cavity polishing fixture of claim 1, wherein, Specifically comprising the following steps:

8. A method of manufacturing an inlay cavity polishing jig for manufacturing the inlay cavity polishing jig according to claim 5, characterized by, Step S1, substrate stamping, placing a standard size fiber glue board under a punch, and using a mold to stamp once to obtain a jig substrate with a cavity; Step S2, injection molding of flexible inlay strip, placing the jig substrate in an injection mold; Step S21, material pretreatment, drying the elastic polymer material particles at 60-120 DEG C for 50-90 min; Step S22, heating and melting, using segmented heating, the temperature is raised from 180 DEG C to 250 DEG C in stages, so that the elastic polymer material particles are completely melted; Step S23, mold closing, mold closing is carried out in three stages (25%, 35%, 30%); Step S26, using normal temperature water cooling to make the elastic polymer material into shape, and the cooling time is 13s±3s; Step S24, injecting the molten elastic polymer material particles into the mold cavity at a pressure of 245°C-260°C and 1450 kgf / cm 2 ±300 kgf / cm 2 for 6 s ± 3 s. Step S25, pressure holding, pressure of 160 kgf / cm 2 ± 20 kgf / cm 2 pressure holding at a pressure of 160 kgf / cm Step S27, mold opening, mold opening is carried out in three stages (3%, 25%, 15%); Step S28, demolding, using a ejector pin to eject the product, and the ejection time is 1-3s; Step S3, post-processing, checking whether there are glue defects, burrs and deformation defects, polishing the burrs, and completing production. ​

Images