An umbrella-shaped center structure for machining a middle hole shaft

Abstract

The utility model discloses an umbrella -like top centre structure for middle hole shaft processing relates to machining technical field, including umbrella -like top centre head, connecting column and quick -change connecting sleeve. The umbrella shape locating surface of umbrella -like top centre head is composed of conical surface and annular plane, and the circular recess is set up in the middle part of annular plane and is built -in top block, and the screw thread drive of connecting column can drive top block to retract in the recess, to adapt to the middle hole shaft center hole of different depth. The outer thread of connecting column rear end is linked with quick -change connecting sleeve, and quick -change connecting sleeve sets up standard taper interface and adapts lathe tailstock. The cross net -like antiskid texture is established to top block front end surface, and the annular sliding slot of umbrella -like top centre head other end cooperates with the slider of internal thread sleeve, and the length of top block is adjusted through the rotation internal thread sleeve drive connecting column. The structure has solved the problem of the positioning instability of traditional top centre because of the depth difference of center hole, has the advantages such as convenient adjustment, support stable, strong adaptability and installation efficient, is applicable to the high -precision processing of middle hole shaft.

Description

Technical Field

[0001] This utility model relates to the field of machining technology, specifically to an umbrella-shaped tip structure for machining a central hole shaft. Background Technology

[0002] In the field of machining, during the turning and grinding of shaft parts with central holes (such as drive shafts and motor rotors), it is usually necessary to use a center structure to position and support the shaft to ensure the coaxiality and accuracy of each machined surface. Traditional umbrella-shaped centers mainly rely on a combination of a conical surface and an annular plane to mate with the central hole of the shaft: the conical surface contacts the conical surface of the central hole to achieve axial positioning, and the annular plane abuts against the bottom surface of the central hole to increase the support area and prevent vibration or displacement of the shaft during machining. However, in actual production, the depth of the central hole of shafts with central holes of different batches or different specifications may vary significantly due to machining errors or design requirements. When the depth of the central hole is less than the distance from the annular plane of the center to the top of the conical surface, the annular plane cannot contact the bottom surface of the central hole, resulting in the center only being supported by a single point on the conical surface. The support rigidity is insufficient, and under the action of cutting forces, axial movement or radial oscillation is easily generated, which in turn causes problems such as out-of-tolerance machining dimensions and deterioration of surface roughness of the shaft. To address this issue, existing solutions typically involve replacing the center with a different specification or manually grinding the center's end face. However, replacing the center requires stopping the machine for adjustment, increasing auxiliary time, while manual grinding makes it difficult to control precision and can damage the surface hardness of the center, shortening its service life. In addition, if the annular plane of a traditional center does not make good contact with the bottom surface of the center hole, it will lead to uneven distribution of support force, which can easily cause relative sliding between the center and the shaft during high-speed rotation machining, and may even cause wear of the center or scrapping of the shaft.

[0003] Therefore, those skilled in the art have provided an umbrella-shaped tip structure for machining central shaft holes to solve the problems mentioned in the background art. Utility Model Content

[0004] The purpose of this invention is to provide an umbrella-shaped tip structure for machining a central hole shaft, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An umbrella-shaped center structure for machining a central hole shaft includes an umbrella-shaped center head, a connecting post, and a quick-change connecting sleeve. One end of the umbrella-shaped center head is an umbrella-shaped positioning surface, which is composed of a conical surface and an annular plane. The conical surface is used to mate with the conical surface of the central hole of the central hole shaft. A circular groove is formed in the middle of the annular plane, and a top block is placed in the circular groove. The other end of the umbrella-shaped center head is provided with a threaded hole that penetrates into the circular groove. The front end of the connecting post is provided with a front external thread, which is threadedly connected to the threaded hole. The end of the connecting post is fixedly connected to the top block.

[0007] As a further embodiment of this utility model: the other end of the connecting column is provided with a rear external thread, the connecting column is connected to the quick-change connecting sleeve through the rear external thread, and the quick-change connecting sleeve is provided with a standard tapered interface adapted to the machine tool tailstock.

[0008] As a further embodiment of this utility model: the front end face of the top block is flat and has anti-slip texture, and when the front end face of the top block is flush with the front end face of the annular plane, it is in the initial position. By rotating the connecting column, the top block can be driven to extend forward and beyond the annular plane.

[0009] As a further improvement of this utility model: the other end of the umbrella-shaped tip is provided with an annular groove on the outside of the threaded hole.

[0010] As a further improvement of this utility model: the outer side of the slide groove is provided with an internal threaded sleeve, and an annular slider adapted to the slide groove is fixedly connected to the side of the internal threaded sleeve near the umbrella-shaped tip.

[0011] As a further improvement of this utility model: the cross-section of the slide groove is T-shaped, and the cross-section of the slider is adapted to the slide groove.

[0012] As a further improvement of this utility model, the internal threaded sleeve is threadedly connected to the front external thread of the connecting column.

[0013] As a further improvement of this utility model: the top block is made of hard alloy material, and the anti-slip texture on the front end surface of the top block is a cross-mesh structure.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This invention solves the problem of contact failure caused by the difference in the depth of the center hole in traditional centers by using a retractable top block and an umbrella-shaped positioning surface. The top block is made of hard alloy with cross anti-slip texture to enhance friction and wear resistance, ensuring stable support. The threaded transmission structure (connecting column and internal threaded sleeve) enables precise adjustment of the top block extension length, with strong adaptability. The standard tapered interface of the quick-change connecting sleeve supports quick docking with the machine tool tailstock, improving tool changing efficiency. The overall structure increases the support area through surface contact, reduces machining vibration, and improves the coaxiality machining accuracy of the center hole shaft. It is especially suitable for batch production of shafts of different specifications in multiple batches, reducing the scrap rate caused by unstable positioning, and combining practicality and economy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an umbrella-shaped tip structure for machining a central hole shaft.

[0017] Figure 2 This is a schematic diagram of the annular plane in an umbrella-shaped tip structure for machining a central hole shaft.

[0018] Figure 3 This is a schematic diagram of the threaded hole and the slide groove in an umbrella-shaped tip structure for machining a central shaft.

[0019] Figure 4 This is a schematic diagram of the internal thread sleeve in an umbrella-shaped tip structure for machining a central hole shaft.

[0020] In the diagram: 1. Umbrella-shaped tip; 2. Connecting post; 3. Quick-change connecting sleeve; 4. Internal threaded sleeve; 5. Conical surface; 6. Annular plane; 7. Circular groove; 8. Top block; 9. Threaded hole; 10. Front external thread; 11. Rear external thread; 12. Slide groove; 13. Slider. Detailed Implementation

[0021] 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 of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] Reference Figures 1-4This embodiment provides an umbrella-shaped tip structure for machining a central hole shaft, including an umbrella-shaped tip 1, a connecting post 2, and a quick-change connecting sleeve 3. One end of the umbrella-shaped tip 1 is an umbrella-shaped positioning surface, which is composed of a conical surface 5 and an annular plane 6. The conical surface 5 is used to mate with the conical surface of the central hole of the central hole shaft. A circular groove 7 is provided in the middle of the annular plane 6, and a top block 8 is provided in the circular groove 7. The other end of the umbrella-shaped tip 1 is provided with a threaded hole 9 that penetrates into the circular groove 7. The front end of the connecting post 2 is provided with a front external thread 10, which is threadedly connected to the threaded hole 9, and the end of the connecting post 2 is fixedly connected to the top block 8.

[0024] The connecting column 2 is the core component for transmission and connection. Its front external thread 10 engages with the threaded hole 9 of the umbrella-shaped tip 1, converting the rotational motion into the linear motion of the top block 8.

[0025] Example 2

[0026] Reference Figures 1-4 This embodiment is based on the previous embodiment, but differs from the previous embodiment in that the other end of the connecting post 2 is provided with a rear external thread 11, the connecting post 2 is connected to the quick-change connecting sleeve 3 through the rear external thread 11, and the quick-change connecting sleeve 3 is provided with a standard tapered interface adapted to the machine tool tailstock.

[0027] The rear external thread 11 is used to connect the quick-change connecting sleeve 3 to achieve docking with the machine tool tailstock. It can quickly connect with the machine tool tailstock through a standard taper interface (such as Morse taper), which facilitates the replacement and installation of the center and improves processing efficiency.

[0028] Furthermore, the front end face of the top block 8 is flat and has anti-slip texture. When the front end face of the top block 8 is flush with the front end face of the annular plane 6, it is in the initial position. By rotating the connecting column 2, the top block 8 can be driven to extend forward and beyond the annular plane 6. The top block 8 is made of hard alloy material, and the anti-slip texture of the front end face of the top block 8 is a cross mesh structure.

[0029] When the depth of the central hole is appropriate, the annular plane 6 contacts the bottom surface of the central hole, increasing the support area and improving stability. The cross-shaped anti-slip texture on the front end face of the top block 8 can enhance the friction with the bottom surface of the central hole and prevent slippage. When the annular plane 6 cannot reach the bottom surface, the top block 8 extends to provide support. The threaded hole 9 and the front external thread 10 of the connecting column 2 form a threaded pair, converting the rotational motion into linear motion and driving the top block 8 to extend and retract.

[0030] Furthermore, the other end of the umbrella-shaped tip 1 is provided with an annular groove 12 on the outside of the threaded hole 9; an internal threaded sleeve 4 is provided on the outside of the groove 12, and an annular slider 13 adapted to the groove 12 is fixedly connected to the side of the internal threaded sleeve 4 near the umbrella-shaped tip 1; the cross-section of the groove 12 is T-shaped, and the cross-section of the slider 13 is adapted to the groove 12; the internal threaded sleeve 4 is threadedly connected to the front external thread 10 of the connecting post 2.

[0031] The 12T-shaped cross-section design of the annular slide groove, in conjunction with the slider 13, allows the internal threaded sleeve 4 to rotate relative to the umbrella-shaped tip 1 while restricting its axial movement, ensuring the stability of the transmission structure. By rotating the internal threaded sleeve 4, the connecting column 2 is indirectly driven to rotate through its threaded engagement with the connecting column 2, thereby enabling the extension or retraction of the top block 8 and providing a more convenient operation method.

[0032] Working principle: In use, first, based on the estimated depth of the center hole of the central shaft, rotate the internal threaded sleeve 4 to drive the connecting column 2 to rotate. Since the front external thread 10 of the connecting column 2 is threadedly connected to the threaded hole 9 of the umbrella-shaped tip 1, and the end of the connecting column 2 is fixed to the top block 8, the rotation of the connecting column 2 will be converted into the axial movement of the top block 8 in the circular groove 7: when rotating clockwise, the top block 8 extends forward beyond the annular plane 6, and when rotating counterclockwise, it retracts to be flush with the front end face of the annular plane 6. After adjustment, insert the standard tapered interface of the quick-change connecting sleeve 3 into the corresponding tapered hole of the machine tool tailstock and fix it by threaded connection. During processing, the conical surface 5 of the umbrella-shaped tip 1 cooperates with the conical surface of the center hole to achieve initial positioning. If the depth is sufficient, the annular plane 6 and the front end face of the top block 8 abut against the bottom surface together; if the depth is insufficient, the protruding front end face of the top block 8 (cross-mesh anti-slip texture) abuts against the bottom surface, and the two provide stable support through surface contact.

[0033] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An umbrella-shaped tip structure for machining a central hole shaft, characterized in that, The device includes an umbrella-shaped tip (1), a connecting post (2), and a quick-change connecting sleeve (3). One end of the umbrella-shaped tip (1) is an umbrella-shaped positioning surface, which is composed of a conical surface (5) and an annular plane (6). The conical surface (5) is used to mate with the conical surface of the central hole of the central shaft. A circular groove (7) is provided in the middle of the annular plane (6). A top block (8) is provided in the circular groove (7). The other end of the umbrella-shaped tip (1) is provided with a threaded hole (9) that penetrates into the circular groove (7). The front end of the connecting post (2) is provided with a front external thread (10), which is threadedly connected to the threaded hole (9). The end of the connecting post (2) is fixedly connected to the top block (8).

2. The umbrella-shaped tip structure for machining a central hole shaft according to claim 1, characterized in that, The other end of the connecting post (2) is provided with a rear external thread (11). The connecting post (2) is connected to the quick-change connecting sleeve (3) through the rear external thread (11). The quick-change connecting sleeve (3) is provided with a standard taper interface adapted to the machine tool tailstock.

3. The umbrella-shaped tip structure for machining a central hole shaft according to claim 1, characterized in that, The front end face of the top block (8) is flat and has anti-slip texture. When the front end face of the top block (8) is flush with the front end face of the annular plane (6), it is in the initial position. By rotating the connecting column (2), the top block (8) can be driven to extend forward and beyond the annular plane (6).

4. The umbrella-shaped tip structure for machining a central hole shaft according to claim 1, characterized in that, The other end of the umbrella-shaped tip (1) is provided with an annular groove (12) on the outside of the threaded hole (9).

5. The umbrella-shaped tip structure for machining a central hole shaft according to claim 4, characterized in that, The outer side of the slide groove (12) is provided with an internal threaded sleeve (4), and the internal threaded sleeve (4) is fixedly connected to a ring-shaped slider (13) that is adapted to the slide groove (12) on the side near the umbrella-shaped tip (1).

6. The umbrella-shaped tip structure for machining a central hole shaft according to claim 5, characterized in that, The cross-section of the groove (12) is T-shaped, and the cross-section of the slider (13) is adapted to the groove (12).

7. The umbrella-shaped center tip structure for machining a central hole shaft according to claim 6, characterized in that, The internal threaded sleeve (4) is threadedly connected to the front external thread (10) of the connecting column (2).

8. The umbrella-shaped tip structure for machining a central hole shaft according to claim 1, characterized in that, The top block (8) is made of hard alloy material, and the anti-slip texture on the front end face of the top block (8) is a cross mesh structure.

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