A telescopic centre

Abstract

The utility model discloses a telescopic centre, relates to two centre locking structure technical field of super precision machine, including drive cylinder, fixed base and lathe frame, one side of fixed base is equipped with connecting shaft, and drive cylinder and connecting shaft all are connected with lathe frame, and the telescopic end fixed connection of drive cylinder has movable centre, and one side fixed mounting of fixed base has the positioning flange, positioning mechanism, positioning mechanism includes adjusting screw, spring and telescopic centre, and adjusting screw is installed at one end of connecting shaft through the screw joint, and spring and telescopic centre all are located in the inside of connecting shaft and fixed base, and one end movable sleeve of spring is connected in the screw rod outside of adjusting screw, and the other end fixed connection of spring has sliding block. The utility model relies on the telescopic characteristics of centre and the positioning flange of matched size to carry out the combination axial positioning, and the precision of positioning flange two sides grinding can reach 0.003mu m positioning reference, thereby can improve the axial positioning precision greatly, and the practicality is higher.

Description

Technical Field

[0001] This utility model relates to the technical field of locking structure for two centers of ultra-precision machine, and in particular to a retractable center. Background Technology

[0002] The two-center locking structure of an ultraprecision machining center is a mechanical device used to fix and position a workpiece, ensuring that the workpiece maintains a stable and precise position during machining. This structure typically includes two centers, located at opposite ends of the workpiece, which are fixed in place by rotation and clamping. The centers are key components for securing the workpiece ends and are usually made of high-strength materials to ensure durability and precision. The centers can be rotary centers, allowing the workpiece to rotate during machining.

[0003] With the increasing demands for high-precision workpiece positioning accuracy in the industrial sector, the existing two-center structure cannot meet the requirements for axial positioning. A new telescopic center structure has been researched to meet the requirements for high-precision positioning. For example, the axial positioning of traditional two-centers relies entirely on the depth of the center hole, which can only achieve a positioning accuracy of 0.05μm, making it difficult to meet the high axial positioning accuracy required today. Therefore, a telescopic center is urgently needed to solve the above-mentioned technical problems. Utility Model Content

[0004] This utility model discloses a retractable center, which, through the provision of a positioning mechanism, allows for the adjustment of spring pressure by rotating an adjusting screw according to the weight of different workpieces during operation. This adjusts the spring pressure to meet the radial preload of the retractable center. The workpiece is then placed between the retractable and movable centers, with one end of the center hole contacting the movable center. A drive cylinder is then activated, extending the center and, in conjunction with the movable center, pushing the workpiece forward. This allows the workpiece to first contact the retractable center for radial positioning. As the drive cylinder continues to extend, the retractable center, in conjunction with the movable shaft and slider, compresses the spring and moves backward until one axial end of the workpiece contacts the positioning flange, thus completing axial positioning. Subsequent ultra-precision machining can then proceed. This technical solution abandons the previous method of relying solely on the depth of the center for axial positioning, instead relying on the retractable nature of the center and a matching positioning flange for combined axial positioning. The positioning flange, after grinding on both sides, achieves a positioning reference accuracy of 0.003μm, significantly improving axial positioning accuracy. Therefore, this solution addresses the problems in the prior art.

[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0006] The present invention provides a retractable tip, comprising a drive cylinder, a fixed base, and a machine tool frame. A connecting shaft is provided on one side of the fixed base. Both the drive cylinder and the connecting shaft are connected to the machine tool frame. A movable tip is fixedly connected to the telescopic end of the drive cylinder. A positioning flange is fixedly installed on one side of the fixed base.

[0007] The positioning mechanism includes an adjusting screw, a spring, and a telescopic center. The adjusting screw is screwed to one end of a connecting shaft. The spring and the telescopic center are both located inside the connecting shaft and the fixed seat. One end of the spring is movably sleeved outside the screw of the adjusting screw, and the other end of the spring is fixedly connected to a slider. The other end of the slider is fixedly connected to a movable shaft, and the other end of the movable shaft is fixedly connected to a telescopic center. The other end of the telescopic center movably passes through the inner ring of the fixed seat and the positioning flange.

[0008] Furthermore, the positioning flange has three mounting holes, and the positioning flange is locked and fixed to one side of the fixing seat by three mounting screws.

[0009] Furthermore, a through-hole is provided laterally at the movable shaft, and a limiting guide rod is fixedly installed inside the movable shaft, the limiting guide rod passing through the movable groove.

[0010] Furthermore, the outer wall of the limiting guide rod is in contact with the inner wall of the movable groove, and the outer wall of the limiting guide rod is a smooth surface.

[0011] Furthermore, the size of the telescopic tip is smaller than the inner ring size of the positioning flange, and the telescopic tip moves through the fixed seat without contacting the fixed seat.

[0012] Furthermore, a workpiece is clamped and fixed between the telescopic center and the movable center, one end of the workpiece is fitted and abutted against the positioning flange, and both ends of the workpiece are provided with center holes.

[0013] The present invention has the following advantages over the prior art:

[0014] 1. This technical solution incorporates a positioning mechanism. During operation, the adjusting screw is rotated according to the weight of different workpieces to modify the spring pressure, ensuring sufficient preload for the radial direction of the telescopic center. The workpiece is then placed between the telescopic and movable centers, with one end of the center hole contacting the movable center. The drive cylinder is then activated, extending to push the workpiece forward in conjunction with the movable center, allowing it to contact the telescopic center for radial positioning. As the drive cylinder continues to extend, the telescopic center, in conjunction with the movable shaft and slider, compresses the spring and moves backward until one axial end of the workpiece contacts the positioning flange, thus completing axial positioning. Subsequent ultra-precision machining can then proceed. This solution abandons the previous method of relying solely on the depth of the center for axial positioning, instead utilizing the telescopic nature of the center and a matching positioning flange for combined axial positioning. The positioning flange, after grinding on both sides, achieves a positioning datum accuracy of 0.003μm, significantly improving axial positioning accuracy and demonstrating high practicality.

[0015] 2. This technical solution is easy to use, adjust, maintain, and disassemble. When replacing the positioning flange, you only need to remove three mounting screws to remove the positioning flange and then reinstall the new positioning flange to achieve positioning switching. Moreover, the overall structure is simple and compact, making it suitable for installation inside machine tools. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the structure of this utility model from another perspective;

[0019] Figure 3 This is a schematic diagram of the exploded structure of the workpiece installation according to this utility model;

[0020] Figure 4 This is a schematic diagram of the exploded structure of the telescopic tip installation of this utility model;

[0021] Figure 5 This is a schematic diagram of the internal cross-sectional structure of the present invention;

[0022] Figure 6 This is a schematic diagram of the movable top mounting structure of this utility model.

[0023] In the diagram: 1. Drive cylinder; 2. Fixed base; 3. Machine tool frame; 4. Connecting shaft; 5. Movable center; 6. Positioning flange; 7. Adjusting screw; 8. Spring; 9. Telescopic center; 10. Slider; 11. Movable shaft; 12. Mounting hole; 13. Mounting screw; 14. Movable groove; 15. Limiting guide rod; 16. Workpiece. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0025] In the description of this utility model, it should be understood that the terms "surface", "side", "gap", "peripheral", etc., which indicate orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0026] Reference Figures 1-6 A retractable tip includes a drive cylinder 1, a fixed base 2 and a machine tool frame 3. A connecting shaft 4 is provided on one side of the fixed base 2. Both the drive cylinder 1 and the connecting shaft 4 are connected to the machine tool frame 3. A movable tip 5 is fixedly connected to the telescopic end of the drive cylinder 1. A positioning flange 6 is fixedly installed on one side of the fixed base 2.

[0027] The positioning mechanism includes an adjusting screw 7, a spring 8, and a telescopic tip 9. The adjusting screw 7 is screwed to one end of the connecting shaft 4. The spring 8 and the telescopic tip 9 are both located inside the connecting shaft 4 and the fixed seat 2. One end of the spring 8 is movably sleeved on the outside of the screw of the adjusting screw 7. The other end of the spring 8 is fixedly connected to a slider 10. The other end of the slider 10 is fixedly connected to a movable shaft 11. The other end of the movable shaft 11 is fixedly connected to the telescopic tip 9. The other end of the telescopic tip 9 movably passes through the inner ring of the fixed seat 2 and the positioning flange 6.

[0028] The positioning flange 6 has three mounting holes 12, and the positioning flange 6 is locked and fixed to one side of the fixed seat 2 by three mounting screws 13. The movable shaft 11 has a through movable groove 14, and a limit guide rod 15 is fixedly installed inside the movable shaft 11, which passes through the movable groove 14. The outer wall of the limit guide rod 15 fits against the inner wall of the movable groove 14, and the outer wall of the limit guide rod 15 is a smooth surface. The size of the telescopic tip 9 is smaller than the inner ring size of the positioning flange 6, and the telescopic tip 9 moves through the fixed seat 2 without contacting the fixed seat 2. A workpiece 16 is clamped and fixed between the telescopic tip 9 and the movable tip 5. One end of the workpiece 16 fits against the positioning flange 6, and both ends of the workpiece 16 have tip holes.

[0029] In the specific implementation process, during operation, the adjusting screw 7 can be rotated according to the weight of different workpieces 16 to modify the pressure of the spring 8 so as to meet the radial preload of the telescopic tip 9. Then, the workpiece 16 is placed between the telescopic tip 9 and the movable tip 5, and the tip hole at one end of the workpiece 16 is made to contact the movable tip 5. Then, the drive cylinder 1 is started to extend it, and the movable tip 5 pushes the workpiece 16 forward so that the workpiece 16 first contacts the telescopic tip 9 to perform radial positioning of the workpiece 16. As the drive cylinder 1 continues to extend, the telescopic tip 9 can cooperate with the movable shaft 11 and the slider 10 to compress the spring 8 and move backward until the axial end of the workpiece 16 contacts the positioning flange 6, thereby completing the axial positioning. Then, subsequent ultra-precision machining can be performed. Since this technical solution abandons the previous axial positioning that relies solely on the depth of the tip, it instead relies on the telescopic characteristics of the tip and the positioning flange 6 of the matching size for combined axial positioning. After grinding both sides of the positioning flange 6, the accuracy can reach a positioning reference of 0.003μm, thus greatly improving the axial positioning accuracy.

[0030] The positioning flange 6 has three mounting holes 12. The positioning flange 6 is locked and fixed to one side of the fixing seat 2 by three mounting screws 13. This is so that when the positioning flange 6 needs to be replaced, the positioning flange 6 can be removed by simply removing the three mounting screws 13, and then a new positioning flange 6 can be reinstalled. This achieves the purpose and effect of convenient use, easy adjustment, easy maintenance and easy disassembly.

[0031] Among them, the limiting guide rod 15 can cooperate with the movable groove 14 to limit and guide the movement of the movable shaft 11, thus ensuring the overall stability of the movable shaft 11.

[0032] The outer wall of the limiting guide rod 15 is in contact with the inner wall of the movable groove 14, and the outer wall of the limiting guide rod 15 is a smooth surface in order to ensure the overall stability of the movable shaft 11, while reducing the friction between the limiting guide rod 15 and the movable groove 14, so as to facilitate the movement of the limiting guide rod 15 in the movable groove 14.

[0033] The telescopic tip 9 is smaller than the inner ring size of the positioning flange 6, and the telescopic tip 9 moves through the fixed seat 2 without contacting the fixed seat 2. This is to facilitate the telescopic tip 9 to move, avoid movement obstruction and friction between the telescopic tip 9 and the positioning flange 6 and the fixed seat 2, and extend its overall service life.

[0034] The dimensions of the workpiece 16 are matched with the dimensions of the positioning flange 6. When processing different workpieces 16, the positioning flange 6 with matching dimensions can be disassembled and replaced to improve its applicability.

[0035] Understandably, this technical solution makes extensive use of common standard parts to facilitate maintenance and replacement of parts.

[0036] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A retractable tip, comprising a drive cylinder (1), a fixed base (2), and a machine tool frame (3), characterized in that: A connecting shaft (4) is provided on one side of the fixed seat (2). The driving cylinder (1) and the connecting shaft (4) are both connected to the machine tool frame (3). A movable center (5) is fixedly connected to the telescopic end of the driving cylinder (1). A positioning flange (6) is fixedly installed on one side of the fixed seat (2). The positioning mechanism includes an adjusting screw (7), a spring (8), and a telescopic tip (9). The adjusting screw (7) is screwed to one end of the connecting shaft (4). The spring (8) and the telescopic tip (9) are both located inside the connecting shaft (4) and the fixed seat (2). One end of the spring (8) is movably sleeved on the outside of the screw of the adjusting screw (7). The other end of the spring (8) is fixedly connected to a slider (10). The other end of the slider (10) is fixedly connected to a movable shaft (11). The other end of the movable shaft (11) is fixedly connected to a telescopic tip (9). The other end of the telescopic tip (9) movably passes through the inner ring of the fixed seat (2) and the positioning flange (6).

2. The retractable tip according to claim 1, characterized in that: The positioning flange (6) has three mounting holes (12), and the positioning flange (6) is locked and fixed to one side of the fixing seat (2) by three mounting screws (13).

3. A retractable tip according to claim 1, characterized in that: A through slot (14) is provided horizontally at the movable shaft (11), and a limiting guide rod (15) is fixedly installed inside the movable shaft (11), the limiting guide rod (15) passing through the movable slot (14).

4. A retractable tip according to claim 3, characterized in that: The outer wall of the limiting guide rod (15) is in contact with the inner wall of the movable groove (14), and the outer wall of the limiting guide rod (15) is a smooth surface.

5. A retractable tip according to claim 1, characterized in that: The telescopic tip (9) is smaller than the inner ring size of the positioning flange (6), and the telescopic tip (9) moves through the fixed seat (2) without contacting the fixed seat (2).

6. A retractable tip according to claim 1, characterized in that: A workpiece (16) is clamped and fixed between the telescopic tip (9) and the movable tip (5). One end of the workpiece (16) is in contact with the positioning flange (6), and tip holes are provided at both ends of the workpiece (16).

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