Wandering star wheel structure for rough grinding of glass
By designing a planetary gear structure made of PA engineering plastic, and using annular notches and stepped holes, the problem of dark cracks and edge breakage at the body position during the rough grinding of glass plates was solved, thereby improving the yield rate of glass plates and reducing costs.
Patent Information
- Application Number
- CN202422858651.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-21
AI Technical Summary
During the rough grinding process of glass plates, the existing planetary wheel structure makes the glass plate prone to dark cracks and edge breakage, resulting in an increased defect rate. In addition, traditional materials and processing technology increase costs and labor consumption.
Design a planetary wheel structure with a planetary wheel body made of PA engineering plastic. By opening annular notches and stepped holes on the back of the glass plate, the glass plate can be positioned and protected, avoiding edge chipping caused by shaking and overload during the grinding process. The precision carving process is eliminated, and the cost is reduced by injection molding.
This improved the yield rate of glass plates, reduced production costs and labor consumption, and ensured the stability of glass plates during the grinding process and the quality of finished products.
Smart Images
Figure CN223506963U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of fixture, especially a star wheel structure for glass rough grinding. BACKGROUND
[0002] Before the CNC (Computer numerical control, computer numerical control machine tool) working operation of the mobile phone backboard glass, the surface of the glass raw material often needs to be rough polished to reduce the glass thickness and realize the preliminary grinding of the glass. At present, the star wheel that can be loaded into the grinding machine is mainly used to clamp the glass plate to be rough ground in the industry, a hole with a straight body structure is formed on the star wheel to form a cavity, and during operation, the glass plate is loaded into the cavity, and the star wheel is driven in cooperation with the gear of the grinding machine to drive the glass plate to rotate relative to the grinding disc of the grinding machine, so that the rough grinding of the glass plate is realized through the contact grinding between the grinding disc and the glass plate. However, in the actual grinding process, under the double action of the grinding machine table pressure and the grinding pad, the pressure borne by the glass plate is as high as 300Kg or more, and the glass plate body position is extruded by the inner wall of the hole with a straight body structure, which is prone to dark crack and edge collapse, resulting in an increase in the glass plate defective rate. SUMMARY
[0003] Therefore, it is necessary to provide a star wheel structure for glass rough grinding which can protect the glass plate body position and improve the glass plate yield.
[0004] A star wheel structure for glass rough grinding is used for clamping the glass plate after one-time CNC machining. The back surface of the glass plate is provided with annular notches distributed along the edge of the glass plate and forming a step on the back side of the glass plate. The glass plate includes a secondary CNC cutting part surrounded by the step, a plate-shaped main body part fixed on the main surface of the secondary CNC cutting part and used for forming the step on the edge of the secondary CNC cutting part. The star wheel structure includes a star wheel main body, at least one through hole is formed in the star wheel main body, the through hole includes a first hole penetrating through the back surface of the star wheel main body and used for inserting the secondary CNC cutting part, and a second hole penetrating through the main surface of the star wheel main body and used for accommodating the plate-shaped main body part. The length of the first hole is equal to the length of the secondary CNC cutting part and smaller than the length of the second hole. The width of the first hole is equal to the width of the secondary CNC cutting part and smaller than the width of the second hole. The first hole is in communication with the second hole, and a shoulder part for abutting with the step is formed in the part of the second hole in communication with the first hole. The width of the shoulder part is greater than the width of the step.
[0005] In one embodiment, the inner wall of the second hole is a slope, the width of the second hole gradually increases along the back surface of the star wheel main body towards the main surface of the star wheel main body, and the length of the second hole gradually increases along the back surface of the star wheel main body towards the main surface of the star wheel main body.
[0006] In one embodiment, the inclination angle of the second hole is between 30° and 80°.
[0007] In one embodiment, the shoulder is provided with a shock-absorbing protective layer for conforming to the step.
[0008] In one embodiment, a non-circular limiting hole for the shaft to pass through is provided in the middle of the planetary wheel body.
[0009] In one embodiment, the planetary wheel body has three or four through holes distributed along a circular path, and at least one first leakage hole is provided on the side of the non-circular limiting hole, with the multiple through holes collectively surrounding the first leakage hole.
[0010] In one embodiment, a second leakage hole is formed on the planetary wheel body between two adjacent through holes, and the diameter of the second leakage hole is larger than the diameter of the first leakage hole.
[0011] In one embodiment, the planetary wheel body has a plurality of teeth distributed along a ring path on its annular side surface.
[0012] In one embodiment, the planetary wheel body is made of PA engineering plastic.
[0013] In one embodiment, the planetary wheel body is integrally injection molded.
[0014] The planetary wheel structure for rough grinding of glass according to this utility model is designed with a stepped hole on the planetary wheel body consisting of a first hole and a second hole. After the secondary CNC cutting part of the glass plate is loaded into the first hole, the circumferential side of the secondary CNC cutting part abuts against the inner wall of the first hole, thereby positioning the glass plate and preventing the glass plate from shaking during grinding. The chipping defects generated on the secondary CNC cutting part during rough grinding of the glass plate can be eliminated by removing the secondary CNC cutting part during the secondary CNC machining of the glass plate. At the same time, the distance between the side of the plate-shaped main body (glass plate body) constituting the finished mobile phone back glass and the inner wall of the second hole is greater than 0. This can prevent the plate-shaped main body from developing dark cracks and chipping problems caused by overload during the rough grinding process when the plate-shaped main body abuts against the inner wall of the second hole. This achieves protection of the glass plate body and improves the yield of the final formed mobile phone back glass. Attached Figure Description
[0015] Figure 1 A schematic diagram of the glass plate structure after a single CNC machining process;
[0016] Figure 2 This is a schematic diagram of the planetary wheel structure in one embodiment of the present invention;
[0017] Figure 3 for Figure 2 A partially enlarged structural diagram of part A in the illustrated embodiment;
[0018] Figure 4 This is a schematic diagram of the planetary wheel structure and the glass plate in one embodiment of the present invention. Detailed Implementation
[0019] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model 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 full understanding of this utility model. However, this utility model can be implemented 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 this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.
[0020] Please combine Figures 1-4This utility model discloses a planetary wheel structure for rough grinding of glass, which can protect the position of a glass plate and improve the yield of glass plates. The planetary wheel structure is used to clamp a glass plate 10 after a first CNC machining. The back of the glass plate 10 has an annular notch 110 distributed along the edge of the glass plate 10, forming a step on the back side of the glass plate 10. The glass plate 10 includes a secondary CNC cutting section 120 surrounded by the step, and a plate-shaped main body 130 fixed to the main surface of the secondary CNC cutting section 120 and used to form a step at the edge of the secondary CNC cutting section 120. In this embodiment, the back of the glass plate 10 refers to the side of the glass plate 10 adjacent to the planetary wheel structure during the loading process, while the main surface of the glass plate 10 or the secondary CNC cutting section 120 refers to the side of the glass plate 10 away from the planetary wheel structure during the loading process. Furthermore, the glass plate 10 has at least one camera hole 140 that penetrates the plate-shaped main body 130. That is to say, before the glass plate 10 is loaded into the planetary gear structure for rough grinding, the basic shape of the glass plate 10 has been processed by a CNC process, and the camera hole 140 has been processed on the glass plate 10. In other words, the glass plate 10 loaded into the planetary gear structure for rough grinding is actually a back glass blank. The secondary CNC cutting part 120 of the back glass blank will be removed in the subsequent second CNC processing. The plate-shaped main body 130 with the camera hole 140 is retained as the main structure of the mobile phone back glass. That is, the thickness of the plate-shaped main body 130 is the thickness of the finished mobile phone back glass. In the prior art, the plate-shaped main body 130 of the glass plate 10 is inserted into the hole of the straight structure of the planetary wheel. The side (shaft) of the plate-shaped main body 130 abuts against the inner wall of the hole to achieve clamping and limiting of the glass plate 10. Since the glass plate 10 is subjected to a large pressure from the grinding machine table and grinding pad during rough grinding, the shaft of the plate-shaped main body 130 will chip. Since the plate-shaped main body 130 is finally formed into the finished mobile phone back glass, the chipping defect will lead to the defect of the mobile phone back glass.
[0021] In this embodiment, the planetary wheel structure includes a planetary wheel body 20, which is generally circular plate-shaped. At least one through hole 210 is provided on the planetary wheel body 20 for embedding a glass plate 10 after a single CNC machining operation. The through hole 210 includes a first hole 211 penetrating the back side of the planetary wheel body 20 and used for inserting a secondary CNC cutting part 120, and a second hole 212 penetrating the main surface of the planetary wheel body 20 and used for receiving the plate-shaped main body part 130. In other words, the through hole 210 is actually a stepped hole. The back side of the planetary wheel body 20 refers to the side of the planetary wheel body 20 facing away from the glass plate before the glass plate is loaded, and the main surface of the planetary wheel body 20 refers to the side of the planetary wheel body 20 adjacent to the glass plate before the glass plate is loaded. The length of the first hole 211 is equal to the length of the secondary CNC cutting section 120 and less than the length of the second hole 212. The width of the first hole 211 is equal to the width of the secondary CNC cutting section 120 and less than the width of the second hole 212. The first hole 211 and the second hole 212 are connected. A shoulder 213 for fitting against the step is formed in the part of the second hole 212 that is connected to the first hole 211. The width of the shoulder 213 is greater than the width of the step. This can be understood as follows: the inner contour shape and size of the first hole 211 are adapted to the outer contour shape and size of the secondary CNC cutting part 120. The width of the part protruding from the secondary CNC cutting part 120 (i.e., the step) on the plate-shaped main body 130 is smaller than the width of the shoulder 213 at the connection between the first hole 211 and the second hole 212. Thus, when the glass plate is loaded into the through hole 210, the circumferential side of the secondary CNC cutting part 120 abuts against the inner wall of the first hole 211 to limit the glass plate along the rotation direction of the planetary wheel body 20, preventing the glass plate from rotating relative to the planetary wheel body 20 during the rotation of the planetary wheel body 20, thereby ensuring the reliability of the glass plate grinding operation. Meanwhile, the back of the plate-shaped main body 130 abuts against the shoulder 213 in the non-contact area (i.e., the step) of the secondary CNC cutting part 120, and the annular side (the body of the plate-shaped main body 130) of the plate-shaped main body 130 does not contact the inner wall of the second hole 212, thereby preventing the body of the plate-shaped main body 130 from chipping under the pressure of the inner wall of the second hole 212.
[0022] The aforementioned planetary wheel structure for rough glass grinding designs the through hole 210 on the planetary wheel body 20 as a stepped hole composed of a first hole 211 and a second hole 212. After the secondary CNC cutting part 120 of the glass plate is inserted into the first hole 211, the circumferential side of the secondary CNC cutting part 120 abuts against the inner wall of the first hole 211, achieving positioning of the glass plate and preventing the glass plate from shaking during grinding. Edge chipping defects generated on the secondary CNC cutting part 120 during rough glass grinding can be mitigated. The secondary CNC machining is achieved by removing the secondary CNC cutting part 120. At the same time, the distance between the side of the plate-shaped main body 130 (glass plate body) constituting the finished mobile phone back glass and the inner wall of the second hole 212 is greater than 0. This can avoid the problem of dark cracks and edge breakage of the plate-shaped main body 130 caused by overload during the rough grinding process when the plate-shaped main body 130 abuts against the inner wall of the second hole 212. This protects the glass plate body and improves the yield of the final formed mobile phone back glass.
[0023] It should be noted that the common glass rough grinding planetary wheels in the industry are made by fine carving glass fiber boards (mainly FR-4 glass fiber boards) to obtain planetary wheels with cavities (glass plate clamping holes). During the fine carving of the cavity, the glass fiber powder generated during the cutting process floats inside the fine carving machine tool. The tiny particles of glass fiber powder will affect the accuracy of the fine carving machine's lead screw. After the cavity structure is finely carved, burrs on the rubber plate need to be cleaned, resulting in high labor costs. The material turnover in multiple processes further increases labor costs. In addition, after the cavity is finely carved, due to the material, the cavity body cannot achieve a high degree of smoothness, which can cause dark cracks or edge chipping problems due to friction when the glass plate contacts the cavity. In this embodiment, the planetary wheel body 20 is made of PA engineering plastic. PA engineering plastics are made by adding glass fibers to polyamide resin (nylon), which increases the tensile strength of the polyamide resin by about 2 times. The shrinkage rate of polyamide resin is 1% to 2%, and it possesses excellent mechanical properties, including high mechanical strength, high softening point, heat resistance, low coefficient of friction, wear resistance, self-lubrication, shock absorption, sound absorption, oil resistance, resistance to weak acids, alkalis, and common solvents, as well as good electrical insulation and weather resistance. Furthermore, in this embodiment, the planetary wheel body 20 is integrally injection molded. This eliminates the need for precision carving of the fiberglass board to obtain the planetary wheel body 20, thus eliminating additional processes and achieving cost reduction and efficiency improvement. By eliminating the precision carving process in the planetary wheel manufacturing process, time, materials, and labor are saved in the overall production process, improving the processing efficiency of the planetary wheel structure and reducing its manufacturing cost.
[0024] In one embodiment, both the first hole 211 and the second hole 212 are rectangular holes with straight bodies. That is, the inner wall of the first hole 211 is a vertical surface extending along the height direction of the first hole 211, and the inner wall of the second hole 212 is a vertical surface extending along the height direction of the second hole 212. In another embodiment, the inner wall of the second hole 212 is a sloped surface. The width of the second hole 212 gradually increases from the back of the planetary wheel body 20 towards the main surface of the planetary wheel body 20, and the length of the second hole 212 gradually increases from the back of the planetary wheel body 20 towards the main surface of the planetary wheel body 20. In other words, the second hole 212 has a flared structure. The length and width of the upper part of the second hole 212 are smaller than the length and width of the lower part of the second hole 212, respectively, to reduce the difficulty of inserting the glass plate into the through hole 210. In addition, designing the inner wall of the second hole 212 as a sloped surface increases the internal space of the second hole 212, which can reduce the amount of material used in the planetary wheel structure, thereby reducing the processing cost of the planetary wheel structure. Furthermore, the tilt angle of the second hole 212 is between 30° and 80°, that is, the angle between the inner wall of the second hole 212 and the back of the planetary wheel body 20 is between 30° and 80°. Preferably, the tilt angle of the second hole 212 is 60°.
[0025] In one embodiment, the shoulder 213 is provided with a shock-absorbing protective layer for fitting against the step. This shock-absorbing protective layer can be a ring-shaped adhesive pad pasted on the shoulder 213, or it can be a silicone layer integrally molded with the planetary wheel body 20 by injection molding. By providing a shock-absorbing protective layer on the shoulder 213, shock absorption and protection of the plate-shaped main body 130 can be achieved, while preventing the plate-shaped main body 130 from being scratched, thereby improving the yield rate of glass plate processing.
[0026] In one embodiment, a non-circular limiting hole 220 for a rotating shaft is provided in the middle of the planetary wheel body 20. The non-circular limiting hole 220 penetrates the main surface and the back surface of the planetary wheel body 20. The inner contour shape of the non-circular limiting hole 220 is adapted to the outer contour shape of the rotating shaft. Thus, the circumferential limiting of the planetary wheel structure and the rotating shaft is achieved by the cooperation between the inner wall of the non-circular limiting hole 220 and the outer surface of the rotating shaft, preventing relative rotation between the two. Furthermore, the annular side surface of the planetary wheel body 20 is provided with a plurality of gear teeth 230 distributed along an annular path. The gear teeth 230 are used to mesh with gears driven by a motor on the grinding machine table, so that the planetary wheel structure and the glass plate mounted on the planetary wheel structure are rotated relative to the grinding disc by the motor and the gear, thereby realizing the grinding of the glass plate.
[0027] To improve the glass plate grinding efficiency, in one embodiment, the planetary wheel body 20 has three or four through holes 210 distributed along a circular path. By opening multiple through holes 210 on the planetary wheel body 20, multiple glass plates can be loaded onto the planetary wheel body 20 at one time, so that multiple glass plates can be processed simultaneously, thereby improving work efficiency. In this embodiment, the multiple through holes 210 are evenly opened on the planetary wheel body 20 along the circular path. In this way, when glass plates are loaded on each through hole 210, the planetary wheel body 20 is subjected to uniform force, which can avoid the problem of uneven pressure on the glass plate caused by the grinding disc due to the eccentric force on the planetary wheel body 20, thus ensuring the grinding effect of the glass plate. In other embodiments, the number of through holes 210 can be further increased or decreased according to the size of the planetary wheel body 20 and the glass plate, which will not be elaborated here.
[0028] In this embodiment, at least one first drain hole 240 is provided on the side of the non-circular limiting hole 220, and the plurality of through holes 210 together surround the first drain hole 240. Furthermore, a second drain hole 250 is provided on the planetary gear body 20 between two adjacent through holes 210. The diameter of the second drain hole 250 is larger than the diameter of the first drain hole 240. That is, the second drain hole 250 is located outside the space surrounded by the plurality of through holes 210. Thus, during the glass plate grinding process, the cutting fluid inside the space surrounded by the plurality of through holes 210 can be discharged through the first drain hole 240, and the cutting fluid outside the space surrounded by the plurality of through holes 210 can be discharged through the second drain hole 250, thereby preventing the accumulation of cutting fluid on the surface of the planetary gear body 20. In addition, since the planetary wheel body 20 rotates continuously during the grinding process, the cutting fluid on the surface of the planetary wheel body 20 flows towards the edge of the planetary wheel body 20 under the action of centrifugal force, and there is less cutting fluid remaining in the middle of the planetary wheel body 20. Therefore, by making the diameter of the second drain hole 250 larger than the diameter of the first drain hole 240, a large amount of cutting fluid can be discharged through the second drain hole 250, while ensuring that the first drain hole 240 discharges cutting fluid with a smaller size. This avoids the deformation problem of the planetary wheel body 20 caused by the concentrated hole position and large hole area in the middle of the planetary wheel, and ensures the structural stability of the planetary wheel body 20.
[0029] 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.
[0030] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A planetary wheel structure for rough grinding of glass, used to clamp a glass plate after a single CNC machining operation, wherein the back of the glass plate has an annular notch distributed along the edge of the glass plate, forming a step on the back side of the glass plate; the glass plate includes a secondary CNC cutting section surrounded by the step, and a plate-shaped main body fixed to the main surface of the secondary CNC cutting section and used to form the step at the edge of the secondary CNC cutting section; characterized in that, The planetary wheel structure includes a planetary wheel body, on which at least one through hole is provided. The through hole includes a first hole that penetrates the back of the planetary wheel body and is used to insert a secondary CNC cutting part, and a second hole that penetrates the main surface of the planetary wheel body and is used to accommodate a plate-shaped main body part. The length of the first hole is equal to the length of the secondary CNC cutting part and less than the length of the second hole. The width of the first hole is equal to the width of the secondary CNC cutting part and less than the width of the second hole. The first hole and the second hole are connected, and a shoulder is formed in the part of the second hole that is connected to the first hole for fitting with the step. The width of the shoulder is greater than the width of the step.
2. The planetary gear structure for rough glass grinding according to claim 1, characterized in that, The inner wall of the second hole is a slope. The width of the second hole gradually increases from the back of the planetary wheel body to the main surface of the planetary wheel body, and the length of the second hole gradually increases from the back of the planetary wheel body to the main surface of the planetary wheel body.
3. The planetary gear structure for rough glass grinding according to claim 2, characterized in that, The inclination angle of the second hole is between 30° and 80°.
4. The planetary gear structure for rough glass grinding according to claim 1, characterized in that, The shoulder is provided with a shock-absorbing protective layer for fitting against the step.
5. The planetary gear structure for rough grinding of glass according to claim 1, characterized in that, The planetary wheel body has a non-circular limiting hole in the middle for the shaft to pass through.
6. The planetary gear structure for rough glass grinding according to claim 5, characterized in that, The planetary wheel body has three or four through holes distributed along a circular path, and at least one first leakage hole is provided on the side of the non-circular limiting hole, with the multiple through holes collectively surrounding the first leakage hole.
7. The planetary gear structure for rough glass grinding according to claim 6, characterized in that, A second leakage hole is formed between two adjacent through holes on the planetary wheel body. The diameter of the second leakage hole is larger than that of the first leakage hole.
8. The planetary gear structure for rough glass grinding according to claim 1, characterized in that, The planetary wheel body has several teeth distributed along a circular path on its annular side surface.
9. The planetary gear structure for rough grinding of glass according to claim 1, characterized in that, The planetary wheel body is made of PA engineering plastic.
10. The planetary gear structure for rough grinding of glass according to claim 1, characterized in that, The planetary wheel body is made by injection molding in one piece.