Crankshaft machining positioning tool
By introducing an adjustable center frame and ball bearing support structure into the crankshaft machining positioning fixture, the problems of insufficient precision and stability in the machining of large crankshafts are solved, and high-precision and high-stability crankshaft machining effects are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2026-03-31
AI Technical Summary
In the existing technology, the combination of three-jaw chuck and ejector pin is difficult to meet the requirements of high precision and high stability in the machining of large crankshafts. Especially under long-term machining or heavy load conditions, it cannot effectively support large crankshafts, resulting in insufficient machining accuracy and stability.
The crankshaft machining positioning fixture includes a base, a three-jaw chuck, ejector pins, and a center support with multiple adjustable positions. The center support abuts against the crankshaft side wall, sharing the load-bearing capacity of the three-jaw chuck and ejector pins. The ball bearings contact the crankshaft to reduce friction, achieving support and limiting, and adapting to crankshafts of different sizes.
It improves the positioning accuracy and stability during crankshaft machining, extends service life, reduces crankshaft wear and bending deformation, and adapts to the machining needs of crankshafts of different sizes.
Smart Images
Figure CN224058741U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of crankshaft machining positioning devices, and in particular to a crankshaft machining positioning fixture. Background Technology
[0002] As one of the core components of an engine, the crankshaft's machining accuracy directly affects the engine's performance and lifespan. The machining quality of the crankshaft not only relates to the engine's power output and smoothness but also directly impacts the overall vehicle's performance and lifespan. Therefore, improving the positioning accuracy and stability during crankshaft machining has become a key focus in the industry. In existing crankshaft machining processes, a three-jaw chuck combined with a center pin is commonly used for clamping and positioning. Three-jaw chucks are widely used in machining small and medium-sized workpieces due to their simple operation and wide applicability. Furthermore, to improve the machining stability of large crankshafts, auxiliary support devices, such as center supports, are often used. However, these methods have certain limitations in practical applications. For example, while three-jaw chucks can achieve rapid clamping, they can easily lead to instability, especially with large crankshafts due to their significant weight, affecting machining accuracy. In existing technologies, the combination of a three-jaw chuck and a center pin is insufficient to meet the high precision and stability requirements of complex crankshaft machining processes. In the machining of large crankshafts, such as marine engine crankshafts, the excessive size and weight make traditional clamping methods completely unsuitable. Especially under long-term processing or heavy-load conditions, the crankshaft cannot be clamped and processed by relying solely on the support of a three-jaw chuck and a center pin. A support device is needed to assist in the clamping and processing without affecting the use of a rotary ring to process the crankshaft. Utility Model Content
[0003] The purpose of this application is to overcome the above-mentioned technical problems and provide a crankshaft machining positioning fixture.
[0004] A crankshaft machining positioning fixture includes a base, a three-jaw chuck at one end of the base, and a center pin fixedly connected to the other end of the base. Multiple center supports are mounted on the base, which abut against and support the sidewalls of the crankshaft. By adopting this technical solution, during user operation, the center supports abut against and support the sidewalls of the crankshaft, sharing the load-bearing capacity of the three-jaw chuck and center pin, extending their service life. They also provide support and load-bearing for the crankshaft, preventing bending deformation during machining and improving machining accuracy. Preferably, the top of the center support has a clearance groove, and symmetrical top rods are provided on both sides of the center support. A support rod is provided in the middle of the center support, and both the support rods and top rods abut against and support the sidewalls of the crankshaft. By adopting this technical solution, during user operation, the support rods abut against the bottom of the crankshaft, providing support and load-bearing for the crankshaft. The two top rods abut against the symmetrical sides of the crankshaft, limiting the crankshaft's movement and reducing lateral bending due to uneven force during machining. Preferably, the end of the push rod is provided with multiple balls, which protrude from the end of the push rod and abut against the side wall of the crankshaft; the end of the support rod is provided with multiple balls of the same structure, which protrude from the end of the support rod and abut against the side wall of the crankshaft. By adopting the above technical solution, when the user uses the equipment, the balls abut against the crankshaft, replacing the push rod and support rod in direct contact with the crankshaft. The balls can change sliding into rolling, thereby reducing crankshaft wear. Preferably, the center frame has receiving cavities on both sides, and a sleeve is rotatably connected within the receiving cavity. The sleeve has an internal thread, and a screw is fixedly connected to the end of the push rod away from the crankshaft. The screw is threaded into the sleeve. By adopting the above technical solution, when the user uses the equipment, rotating the sleeve drives the screw to rotate. The screw slides along the axial direction of the sleeve, thus adjusting the distance between the push rod and the crankshaft, adapting to crankshafts of different sizes. Preferably, a limiting groove is formed on the outer wall of the sleeve, the limiting groove being arranged along the circumference of the sleeve, and a limiting bolt is provided on the central frame, the limiting bolt being inserted into the limiting groove. By adopting the above technical solution, when the user uses the sleeve, the limiting bolt is inserted into the limiting groove to limit the sleeve, preventing axial displacement during sleeve rotation and allowing the sleeve to rotate. Preferably, a first guide groove is formed on the side wall of the push rod, the first guide groove being arranged along the axial direction of the push rod, and a first guide rod is fixedly connected to the central frame, the first guide rod being inserted into the first guide groove. By adopting the above technical solution, when the user uses the sleeve to drive the guide column to slide, the first guide rod slides in the first guide groove, guiding and limiting the push rod, making the push rod slide more stably. Preferably, the central frame has a receiving groove at the position corresponding to the support rod, a worm gear is fixedly connected to the side wall of the support rod, a drive shaft is rotatably connected to the central frame, a worm is fixedly connected to the middle of the drive shaft, the worm gear and the worm mesh, a protective cover is provided on the worm gear and the worm, the protective cover is fixedly connected to the central frame, and both ends of the drive shaft extend out of the central frame.By adopting the above technical solution, when the user operates the system, rotating the drive shaft causes the support rod to slide vertically via a worm gear and worm, thus adjusting the distance between the support rod and the crankshaft to accommodate crankshafts of different sizes. Preferably, the support rod has a second guide groove on its side wall, which is axially aligned with the support rod. A second guide rod is fixedly connected to the center frame and inserted into the second guide groove. With this technical solution, when the user drives the support rod to slide, the second guide rod slides within the second guide groove, guiding and limiting the support rod's movement, making the sliding more stable. Preferably, the bottom of the center frame has a T-slot, and a T-shaped guide rail is fixedly connected to the top of the base. A locking bolt is threaded onto the center frame. With this technical solution, when the user operates the system, loosening the locking bolt allows the center frame to slide on the T-shaped guide rail, adjusting its position. The position of the center frame can be adjusted according to the crankshaft's crank, preventing interference between the rotary ring and the center frame during machining. Attached Figure Description
[0005] Figure 1 This is a schematic diagram of the overall structure of this application;
[0006] Figure 2 This is a cross-sectional view of this application;
[0007] Figure 3 This is a schematic diagram of the overall structure of the central frame.
[0008] Reference numerals: 1. Base; 11. Three-jaw chuck; 12. Ejector pin; 13. T-shaped guide rail; 2. Center frame; 21. T-shaped slide groove; 22. Locking bolt; 23. Relief groove; 24. Ejector rod; 241. Sleeve; 242. Screw; 243. Limiting groove; 244. Limiting bolt; 245. First guide groove; 246. First guide rod; 25. Support rod; 251. Worm gear; 252. Drive shaft; 253. Worm; 254. Protective cover; 255. Second guide groove; 256. Second guide rod; 26. Ball bearing; 27. Receiving cavity; 28. Receiving groove; 3. Crankshaft. Detailed Implementation
[0009] The following will be combined with the appendix Figure 1-3This application provides a clear and complete description of the technical solutions in the embodiments of this utility model. The described embodiments are only possible technical implementations of this utility model and not all possible implementations. Those skilled in the art can obtain other embodiments in combination with the embodiments of this utility model without creative effort, and these embodiments are also within the protection scope of this utility model. The inventors of this application have found that existing crankshaft machining fixtures have problems such as uneven clamping force and easy workpiece deformation. Therefore, this application mainly adopts the following solution to improve the positioning accuracy and stability during crankshaft machining. The crankshaft machining positioning fixture provided in the embodiments of this application includes a base 1. One end of the base 1 is provided with a three-jaw chuck 11, and the other end is fixedly connected with a pin 12. The base 1 is also provided with multiple adjustable center frames 2. The bottom of the center frame 2 is provided with a T-slot, the top of the base 1 is fixedly connected with a T-shaped guide rail 13, and the center frame 2 is threadedly connected with a locking bolt 22. Loosening the locking bolt 22 allows the center support 2 to slide on the T-shaped guide rail 13, thereby adjusting the position of the center support 2. The position of the center support 2 can be adjusted according to the crankshaft 3's cranks, preventing interference between the rotary ring and the center support 2 during machining. The center support 2 serves to abut against and support the side wall of the crankshaft 3, extending its service life by sharing the load-bearing capacity of the three-jaw chuck 11 and the ejector pin 12. Simultaneously, it provides support and load-bearing for the crankshaft 3, preventing bending deformation during machining and thus improving machining accuracy.
[0010] Specifically, the top of the center frame 2 is provided with a clearance groove 23, and push rods 24 are provided on both sides of the center frame 2 symmetrically, while a support rod 25 is provided in the middle of the center frame 2. Both the push rods 24 and the support rod 25 are used to abut and support the side wall of the crankshaft 3. The support rod 25 is used to abut the bottom of the crankshaft 3, providing support and load-bearing for the crankshaft 3. The two push rods 24 abut on both sides of the crankshaft 3 symmetrically, which can limit the movement of the crankshaft 3 and reduce the risk of lateral bending of the crankshaft 3 due to uneven force during machining.
[0011] The end of the push rod 24 is provided with multiple balls 26, which protrude from the end of the push rod 24 and abut against the side wall of the crankshaft 3. Similarly, the end of the support rod 25 is also provided with multiple balls 26 of the same structure, which protrude from the end of the support rod 25 and abut against the side wall of the crankshaft 3. The contact between the balls 26 and the crankshaft 3 converts sliding friction into rolling friction, thereby reducing wear on the crankshaft 3. The balls 26 can be made of stainless steel, which has high wear resistance and corrosion resistance.
[0012] The center frame 2 has receiving cavities 27 on both sides, and a sleeve 241 is rotatably connected within the receiving cavity 27. The sleeve 241 has internal threads. A screw 242 is fixedly connected to the end of the push rod 24 away from the crankshaft 3. The screw 242 is threaded into the sleeve 241. A limiting groove 243 is provided on the outer wall of the sleeve 241, and the limiting groove 243 is arranged circumferentially along the sleeve 241. A limiting bolt 244 is provided on the center frame 2, and the limiting bolt 244 is inserted into the limiting groove 243. The limiting bolt 244 limits the sleeve 241, so that the sleeve 241 can only rotate on its own axis. By rotating the sleeve 241, the rotation of the sleeve 241 drives the screw 242 to rotate. The screw 242 slides along the axial direction of the sleeve 241, thereby adjusting the distance between the push rod 24 and the crankshaft 3 to adapt to crankshafts 3 of different sizes.
[0013] The side wall of the push rod 24 has a first guide groove 245, which is arranged along the axial direction of the push rod 24. A first guide rod 246 is fixedly connected to the center frame 2 and is inserted into the first guide groove 245. When the sleeve 241 drives the push rod 24 to slide, the first guide rod 246 slides in the first guide groove 245, which guides and limits the push rod 24, making the sliding of the push rod 24 more stable.
[0014] A receiving groove 28 is provided on the center frame 2 corresponding to the position of the support rod 25. A worm gear 251 is fixedly connected to the side wall of the support rod 25. A drive shaft 252 is rotatably connected to the center frame 2. A worm 253 is fixedly connected to the middle of the drive shaft 252. The worm gear 251 and the worm 253 mesh. A protective cover 254 is fitted over the worm gear 251 and the worm 253. The protective cover 254 is fixedly connected to the center frame 2. Both ends of the drive shaft 252 extend out of the center frame 2. By rotating the drive shaft 252, the drive shaft 252 drives the support rod 25 to slide vertically through the cooperation of the worm gear 251 and the worm 253, thereby adjusting the distance between the support rod 25 and the crankshaft 3 to accommodate crankshafts of different sizes.
[0015] A second guide groove 255 is provided on the side wall of the support rod 25, and the second guide groove 255 is arranged along the axial direction of the support rod 25. A second guide rod 256 is fixedly connected to the central frame 2, and the second guide rod 256 is inserted into the second guide groove 255. When the support rod 25 is driven to slide, the second guide rod 256 slides in the second guide groove 255, which guides and limits the support rod 25, making the sliding of the support rod 25 more stable.
[0016] The implementation principle of this embodiment is as follows: the crankshaft 3 is initially fixed by a combination of a three-jaw chuck 11 and an ejector pin 12. Multiple center supports 2 then provide support and limit the crankshaft 3 from different positions, ensuring its stability during processing and preventing bending deformation due to its own weight or uneven processing forces. The design of the ball bearings 26 transforms sliding friction into rolling friction, effectively reducing wear on the crankshaft 3. The adjustment mechanism of the ejector pin 24 and support rod 25 allows the fixture to adapt to the processing requirements of crankshafts 3 of different sizes, significantly improving the processing accuracy and stability of the crankshaft 3. The above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.
Claims
1. A crankshaft machining positioning fixture, characterized by: The base (1) is provided with a three-jaw chuck (11) at one end, and a thimble (12) is fixedly connected to the other end of the base (1), and a plurality of center supports (2) are arranged on the base (1), and the center supports (2) are used for abutting and supporting the side wall of the crankshaft (3).
2. The machining positioning fixture for a crankshaft according to claim 1, characterized in that: The top of the center support (2) is provided with a displacement slot (23), and the two sides of the center support (2) are provided with a top rod (24), and the middle of the center support (2) is provided with a supporting rod (25), and the supporting rod (25) and the top rod (24) are used for abutting and supporting the side wall of the crankshaft (3).
3. The machining positioning fixture for a crankshaft according to claim 2, characterized in that: The end of the top rod (24) is provided with a plurality of balls (26), and the balls (26) protrude from the end of the top rod (24) and abut against the side wall of the crankshaft (3); the end of the supporting rod (25) is provided with a plurality of balls (26) which are the same in structure, and the balls (26) protrude from the end of the supporting rod (25) and abut against the side wall of the crankshaft (3).
4. The machining positioning fixture for a crankshaft according to claim 2, characterized in that: The two sides of the center support (2) are provided with accommodating cavities (27), and the accommodating cavities (27) are rotatably connected with sleeves (241), and the sleeves (241) are provided with internal threads, and one end of the top rod (24) away from the crankshaft (3) is fixedly connected with a screw rod (242), and the screw rod (242) is threadedly connected in the sleeve (241).
5. The machining positioning fixture for a crankshaft according to claim 4, characterized in that: The outer side wall of the sleeve (241) is provided with a limiting slot (243), and the limiting slot (243) is arranged along the circumference of the sleeve (241), and the center support (2) is provided with a limiting bolt (244) which is inserted into the limiting slot (243).
6. The machining positioning fixture for a crankshaft according to claim 4, characterized in that: The side wall of the top rod (24) is provided with a first guide slot (245), and the first guide slot (245) is arranged along the axial direction of the top rod (24), and the center support (2) is fixedly connected with a first guide rod (246) which is inserted into the first guide slot (245).
7. The machining positioning fixture for a crankshaft according to claim 2, characterized in that: The center support (2) is provided with an accommodating slot (28) corresponding to the position of the supporting rod (25), and the side wall of the supporting rod (25) is fixedly connected with a worm wheel (251), and the center support (2) is rotatably connected with a transmission shaft (252), and the middle of the transmission shaft (252) is fixedly connected with a worm (253), and the worm wheel (251) and the worm (253) are engaged, and the worm wheel (251) and the worm (253) are provided with a protective cover (254), and the protective cover (254) is fixedly connected to the center support (2), and the two ends of the transmission shaft (252) extend out of the center support (2).
8. The machining positioning fixture for a crankshaft according to claim 2, characterized in that: The side wall of the supporting rod (25) is provided with a second guide slot (255), and the second guide slot (255) is arranged along the axial direction of the supporting rod (25), and the center support (2) is fixedly connected with a second guide rod (256) which is inserted into the second guide slot (255).
9. The machining positioning fixture for a crankshaft according to claim 1, characterized in that: The bottom of the center support (2) is provided with a T-shaped slot, the top of the base (1) is fixedly connected with a T-shaped guide rail (13), and the center support (2) is threadedly connected with a locking bolt (22).