Bidirectional extrusion self-centering tensioning device
By adopting a combined structure of a fixed mandrel and a sliding mandrel in the tightening device, combined with the symmetrical conical surface and extrusion nut design, the problems of large tightening resistance and uneven force in the existing technology are solved, and more efficient installation and more uniform tightening effect are achieved.
Patent Information
- Application Number
- CN202420629220.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-29
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-03-29
AI Technical Summary
In the prior art, the tightening device has a large resistance, resulting in low installation efficiency and uneven tightening force, which affects the centering accuracy.
A two-way extrusion self-centering tightening device is designed, and a combination structure of a fixed mandrel and a sliding mandrel is adopted. When the sliding mandrel is squeezed by the swell, it slides along the fixed mandrel to reduce friction resistance. Through the coordination of the symmetrical conical surface structure and the extrusion nut, the swell is guided to apply force from both ends to the middle to achieve uniform tightening.
The mandrel slide reduces tightening resistance, improves working efficiency, ensures a more uniform tightening force, and improves centering accuracy and installation efficiency.
Smart Images
Figure CN222569319U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tensioning devices, in particular to a bidirectional extrusion self-centering tensioning device. Background Art
[0002] At present, turning is often used instead of grinding in gear processing, which can avoid crack defects caused by grinding. When tightening gears on a lathe, tensioning is usually used for fixing.
[0003] In the prior art, most lathes use a rigid tapered mandrel to center the workpiece, which makes it difficult to move the workpiece up and down and has low efficiency. Some of the prior art technical solutions use elastic expansion sleeves for tensioning, and most of them use a conical structure design with a one-way inclined guide surface of the mandrel. An extrusion force is applied to the expansion sleeve from one side of the end with a smaller outer diameter, so that the expansion sleeve is squeezed and deformed by the movable extrusion nut and the fixed support end in a limited space, and expands in a direction away from the axis, thereby centering and tightening the workpiece. In this process, the expansion sleeve with an inclined contact cone surface with the mandrel will continue to be squeezed toward one end. Because the mandrel is fixed, the workpiece basically does not move relative to each other. The expansion sleeve encounters greater resistance during the extrusion process, and it takes a lot of effort to twist the extrusion nut, affecting the installation efficiency.
[0004] In this tightening method, the expansion sleeve usually starts to deform from the end with a smaller outer diameter close to the core shaft to tighten the workpiece. During the process, the force on the inner diameter of the workpiece is not very uniform, and the coaxiality is prone to being inaccurate. Manual correction is also required, which also affects the installation efficiency.
[0005] Therefore, designing a device that can slide the mandrel to reduce the tensioning resistance, improve work efficiency, and make the tensioning force more uniform is exactly the problem that the inventor wants to solve. Utility Model Content
[0006] In view of the deficiencies of the prior art, the purpose of the utility model is to provide a bidirectional extrusion self-centering tensioning device, which can realize the function of mandrel sliding, thereby reducing tensioning resistance and improving work efficiency, and making the tensioning force more uniform.
[0007] The technical solution adopted by the device of the utility model is: a two-way extrusion self-centering tensioning device, which includes a main body, the right end of the main body is connected with a connecting flange, the connecting flange is connected with a positioning flange through a connecting bolt, the right end of the connecting flange is connected with a connecting shaft, the right end of the connecting shaft is connected with a fixed core shaft, the fixed core shaft is provided with a keyway, the inner side of the keyway is provided with a positioning key, a sliding core shaft is slidably provided on the outer side of the fixed core shaft, a sliding groove is provided on the inner circular side wall of the sliding core shaft, the sliding groove and the positioning key are slidably matched, the outer surface of the sliding core shaft is two symmetrically arranged conical surfaces, the outer side of the sliding core shaft is provided with an expansion sleeve, the inner circular surface of the expansion sleeve is provided with conical surfaces that fit the sliding core shaft and are symmetrically distributed, the right end of the fixed core shaft is provided with an external thread, and the outer side of the right end of the fixed core shaft is threadedly connected with an extrusion nut.
[0008] Furthermore, both ends of the expansion sleeve are provided with symmetrically distributed pressure grooves, the left end of the extrusion nut is arranged on the inner side of the pressure groove at the right end of the expansion sleeve, and the pressure groove at the left end of the expansion sleeve is arranged on the outer side of the right end of the connecting shaft.
[0009] Furthermore, the difference between the outer diameter of the middle portion and the outer diameter of the end portion of the sliding mandrel is greater than 5 mm.
[0010] Furthermore, a contact structure is provided on the outer circumferential surface of the expansion sleeve.
[0011] Furthermore, there is a distance between the two ends of the contact structure and the end of the expansion sleeve, and the distance is not less than 3 cm.
[0012] Furthermore, the connecting shaft is arranged on the inner side of the positioning flange and is clearance-fitted.
[0013] Furthermore, a gear workpiece is arranged outside the contact structure, the length of the contact structure is smaller than the length of the inner circle of the gear workpiece, and the left end of the gear workpiece is in contact with the right end surface of the positioning flange.
[0014] Furthermore, there are gaps between the extrusion nut, the connecting shaft and the sliding mandrel.
[0015] The beneficial effects of the utility model device are:
[0016] 1. The utility model designs the mandrel into two parts, a fixed mandrel and a sliding mandrel. The sliding mandrel is squeezed by the expansion sleeve and slides along the fixed mandrel, thereby reducing the friction resistance received during the extrusion process. The sliding mandrel is designed to have a symmetrical conical surface structure to cooperate with the extrusion nut and the connecting shaft, so that the expansion sleeve can be guided to apply force from both ends to the middle to tighten and deform it, thereby realizing the function of mandrel sliding, thereby reducing the tightening resistance, improving work efficiency, and making the tightening force more uniform. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1It is a structural view of the utility model.
[0018] Explanation of the reference numerals: 1-main body; 2-connecting flange; 3-connecting bolt; 4-positioning flange; 5-connecting shaft; 6-fixed spindle; 7-expansion sleeve; 8-contact structure; 9-slide groove; 10-positioning key; 11-keyway; 12-sliding spindle; 13-pressing groove; 14-extrusion nut; 15-gear workpiece. DETAILED DESCRIPTION
[0019] The following is a further description of the present invention in conjunction with specific embodiments. These embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to the application.
[0020] See also Figure 1 This is a structural view of the utility model, a bidirectional extrusion self-centering tensioning device, which includes a main body 1, the main body 1 is used for docking and connection with a machine tool, the right end of the main body 1 is connected with a connecting flange 2, the connecting flange 2 is used to connect external docking components, the connecting flange 2 is connected to a positioning flange 4 through a connecting bolt 3, the right end of the connecting flange 2 is connected to a connecting shaft 5, the right end of the connecting shaft 5 is connected to a fixed core shaft 6, a key groove 11 is provided on the fixed core shaft 6, a positioning key 10 is provided on the inner side of the key groove 11, a sliding core shaft 12 is slidably provided on the outer side of the fixed core shaft 6, a slide groove 9 is provided on the inner circular side wall of the sliding core shaft 12, the slide groove 9 is slidably matched with the positioning key 10, so that the sliding core shaft 12 is slidably matched with the positioning key 10, and when the sliding core shaft 12 is subjected to external force, it can slide relative to the fixed core shaft 6 along the direction of the slide groove 9.
[0021] The outer surface of the sliding mandrel 12 is two symmetrically arranged conical surfaces. The difference between the outer diameter of the middle part and the outer diameter of the end part of the sliding mandrel 12 is greater than 5 mm. An expansion sleeve 7 is arranged on the outer side of the sliding mandrel 12. The inner surface of the expansion sleeve 7 is provided with a conical surface that fits the sliding mandrel 12 and is symmetrically distributed. The right end of the fixed mandrel 6 is provided with an external thread. The right end of the fixed mandrel 6 is threadedly connected with an extrusion nut 14. Both ends of the expansion sleeve 7 are provided with symmetrically distributed pressure grooves 13. The left end of the extrusion nut 14 is arranged on the inner side of the pressure groove 13 located at the right end of the expansion sleeve 7. The pressure groove 13 located at the left end of the expansion sleeve 7 is arranged on the outer side of the right end of the connecting shaft 5. The circumferential surface of the sliding mandrel 12 is designed to be a symmetrically arranged conical surface, and then designed The matching expansion sleeve 7 makes the expansion sleeve 7 shrink toward the left end when it is squeezed by the extrusion nut 14. During this process, the extrusion nut 14 and the connecting shaft 5 work together to continuously squeeze the expansion sleeve 7. The position of the sliding core shaft 12 moves with the continuous deformation of the expansion sleeve 7. The friction resistance encountered by the expansion sleeve 7 is smaller than the friction between the core shaft and the expansion sleeve 7 in a fixed state. The expansion sleeve 7 of the utility model is squeezed and deformed along the conical surface of the sliding core shaft 12 toward the middle part of the sliding core shaft 12 when both ends are stressed at the same time. The starting part of the deformation is located at both ends of the expansion sleeve 7, which can ensure that the inner circle of the gear workpiece 15 is evenly stressed during deformation, and will not cause axial deviation due to stress at one end.
[0022] A contact structure 8 is provided on the outer circumferential surface of the expansion sleeve 7, and there is a spacing between the two ends of the contact structure 8 and the end of the expansion sleeve 7, and the spacing is not less than 3 cm. In order to ensure that the outer surface of the expansion sleeve 7 will not spread outward and get stuck on the inner circle end of the gear workpiece 15 due to the extrusion force during the extrusion process of the expansion sleeve 7 by the extrusion gear, a contact structure 8 with a spacing from the end of the expansion sleeve 7 is specially designed, and the contact structure 8 contacts the inner circle of the gear workpiece 15 through the contact structure 8. At the same time, the length of the contact structure 8 is less than the length of the inner circle of the gear workpiece 15, thereby ensuring that the contact structure 8 is completely placed in the inner circle of the gear workpiece 15 before the extrusion starts.
[0023] The connecting shaft 5 is arranged on the inner side of the positioning flange 4 and is clearance-fitted. There are gaps between the extrusion nut 14, the connecting shaft 5 and the sliding core shaft 12, and the distance of the gap is not less than 3 cm, which is sufficient to ensure that after the extrusion gear is extruded and the expansion sleeve 7 is extruded, the sliding core shaft 12 will not be pressed tightly against the end face of the connecting shaft 5. A gear workpiece 15 is arranged on the outside of the contact structure 8, and the left end of the gear workpiece 15 is in contact with the right end face of the positioning flange 4.
[0024] The utility model designs the mandrel into two parts, a fixed mandrel 6 and a sliding mandrel 12. The sliding mandrel 12 is squeezed by the expansion sleeve 7 and slides along the fixed mandrel 6, thereby reducing the friction resistance received during the extrusion process. The sliding mandrel 12 is designed to have a structure with symmetrical conical surfaces, and cooperates with the extrusion nut 14 and the connecting shaft 5, so that the expansion sleeve 7 can be guided to apply force from both ends toward the middle to make it tighten and deform, thereby realizing the function of mandrel sliding, thereby reducing the tightening resistance, improving work efficiency, and making the tightening force more uniform.
Claims
1. A bidirectional extrusion self-centering tensioning device, characterized in that: The invention comprises a main body (1), the right end of the main body (1) is connected to a connecting flange (2), the connecting flange (2) is connected to a positioning flange (4) via a connecting bolt (3), the right end of the connecting flange (2) is connected to a connecting shaft (5), the right end of the connecting shaft (5) is connected to a fixed core shaft (6), a key groove (11) is provided on the fixed core shaft (6), a positioning key (10) is provided inside the key groove (11), a sliding core shaft (12) is slidably provided outside the fixed core shaft (6), the sliding core shaft (12) is provided on the outside of the fixed core shaft (6), and the sliding core shaft (12) is provided on the inside of the fixed core shaft (6). A slide groove (9) is provided on the inner circular side wall of the moving core shaft (12), and the slide groove (9) is slidably matched with the positioning key (10). The outer surface of the sliding core shaft (12) is two symmetrically arranged conical surfaces. An expansion sleeve (7) is provided on the outer side of the sliding core shaft (12), and the inner circular surface of the expansion sleeve (7) is provided with a conical surface that fits the sliding core shaft (12) and is symmetrically distributed. The right end of the fixed core shaft (6) is provided with an external thread, and the outer side of the right end of the fixed core shaft (6) is threadedly connected with an extrusion nut (14).
2. A bidirectional extrusion self-centering tensioning device according to claim 1, characterized in that: Both ends of the expansion sleeve (7) are provided with symmetrically distributed pressing grooves (13); the left end of the extrusion nut (14) is arranged inside the pressing groove (13) located at the right end of the expansion sleeve (7); and the pressing groove (13) located at the left end of the expansion sleeve (7) is arranged outside the right end of the connecting shaft (5).
3. A bidirectional extrusion self-centering tensioning device according to claim 1, characterized in that: The difference between the outer diameter of the middle portion and the outer diameter of the end portion of the sliding mandrel (12) is greater than 5 mm.
4. A bidirectional extrusion self-centering tensioning device according to claim 1, characterized in that: A contact structure (8) is provided on the outer circumferential surface of the expansion sleeve (7).
5. A bidirectional extrusion self-centering tensioning device according to claim 4, characterized in that: There is a distance between the two ends of the contact structure (8) and the end of the expansion sleeve (7), and the distance is not less than 3 cm.
6. A bidirectional extrusion self-centering tensioning device according to claim 1, characterized in that: The connecting shaft (5) is arranged on the inner side of the positioning flange (4) and is clearance-fitted.
7. A bidirectional extrusion self-centering tensioning device according to claim 4, characterized in that: A gear workpiece (15) is arranged outside the contact structure (8), the length of the contact structure (8) is smaller than the length of the inner circle of the gear workpiece (15), and the left end of the gear workpiece (15) is in contact with the right end surface of the positioning flange (4).
8. The bidirectional extrusion self-centering tensioning device according to claim 1, characterized in that: There are gaps between the extrusion nut (14), the connecting shaft (5) and the sliding core shaft (12).