Center positioning device
By designing a top positioning device including a rotary disc, a top body, an elastic mechanism and a drive pin, the problem of low machining efficiency and difficult to guarantee the concentricity of large shaft parts in traditional processes is solved, and a single clamping is completed is achieved, which improves accuracy and efficiency.
Patent Information
- Application Number
- CN202421590946.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-08
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-08
AI Technical Summary
When processing large shaft parts, traditional top-notch positioning devices require multiple clamping, correction and processing, resulting in low production efficiency and difficulty in ensuring concentricity, especially in scenarios with high accuracy requirements.
A top positioning device including a turntable, a top body, an elastic mechanism and a drive pin is designed. By aligning the top body with the center of the end face of the workpiece, the elastic mechanism provides forward elastic force, and the driving pin abuts the workpiece, forming a firm connection to ensure concentricity and machining accuracy.
It realizes the completion of machining of large shaft parts at one time, improves production efficiency and processing accuracy, solves the problem of difficult to ensure concentricity at both ends, and ensures product quality.
Smart Images
Figure CN222919648U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of tooling, and particularly relates to a center positioning device. Background Art
[0002] The center positioning device is applicable to the turning processing of various shaft parts and is an important auxiliary tool in the turning processing of shaft parts. The center positioning device affects the machining accuracy, production efficiency, and finished product quality of the product.
[0003] However, when machining large shaft parts traditionally, the method of one center and one chuck, and segmented machining is usually adopted, that is, one end is machined first, and then the other end is machined. This process requires multiple clamping, alignment, and machining. Each clamping requires repositioning of the center hole, increasing the operation steps and time, resulting in low production efficiency. In addition, there is error accumulation between the two machining processes, making it difficult to ensure the concentricity of both ends of the workpiece and affecting the product quality. Especially for shaft parts with high precision requirements, segmented machining is difficult to meet the concentricity requirements. Summary of the Utility Model
[0004] Aiming at the deficiencies of the existing technology, the utility model provides a center positioning device, aiming to: through this center positioning device, realize the machining of large shaft parts in one clamping, and solve the problem of non-concentricity at both ends during the machining of large shaft parts.
[0005] To achieve the above purpose, the utility model is realized through the following technical solutions: a center positioning device, including a turntable, a center body, an elastic mechanism, and a set of driving pins. A center hole is provided in the center of the turntable, and the center hole is arranged along the rotation axis direction of the turntable. The center body is slidably installed in the center hole, and the front end of the center body is conical. The elastic mechanism is installed on the turntable and applies a forward elastic force to the center body. On the front end face of the turntable, a set of first mounting holes are arranged in a circular array around the rotation axis, the axis of each first mounting hole is parallel to the axis of the turntable, and a driving pin is slidably arranged in each first mounting hole. A receiving cavity communicating with the center hole is provided inside the turntable, and a floating disk is swingably installed in the receiving cavity. When the driving pin retreats under the action of a backward external force, it presses the floating disk to swing adaptively.
[0006] The center positioning device provided by the utility model is applicable to the scenario of precision machining of shaft parts. During clamping, the workpiece is placed between the center positioning device provided by the utility model and the center of the tailstock. The center body and the center of the tailstock are respectively aligned with the center of the workpiece. Under the action of the tightening force of the tailstock, the center body is pressed to move backward, and the driving pin starts to contact the workpiece until multiple driving pins abut against the workpiece, completing the clamping.
[0007] Among them, the tip body positions the center of the end face of the workpiece. The elastic mechanism provides a forward elastic force to the tip body, pressing the tip body tightly against the center of the end face of the workpiece. A plurality of driving pins are in contact with the workpiece to form a firm connection. The cooperation between the tip body and the driving pins enables the tip positioning device to finally clamp the workpiece, effectively controlling the concentricity of workpiece positioning and ensuring the machining accuracy.
[0008] In addition, the floating disk allows the driving pins to axially move within the first mounting holes. During the clamping process, when the pressure between each driving pin and the workpiece is uneven, the pressure difference causes the floating disk to swing, allowing the driving pins to adaptively move according to the shape of the workpiece end face, ensuring that at least three driving pins are pressed against the workpiece end face.
[0009] Furthermore, for the above-mentioned tip positioning device, the turntable includes a front cover and a rear cover that are detachably connected. The gap between the front cover and the rear cover forms a receiving cavity. The tip hole is provided at the center of the front cover, and the first mounting holes are provided on the front end face of the front cover. The detachable connection between the rear cover and the front cover has a simple and reliable structure, facilitating assembly and disassembly.
[0010] Furthermore, for the above-mentioned tip positioning device, the rear end of the floating disk has a convex portion, and the convex portion is spherical. A first limiting ring is provided between the rear cover and the floating disk. The front end of the first limiting ring has a recessed portion, and the recessed portion is spherical. The recessed portion is in sliding fit with the convex portion. The rear end of the first limiting ring presses against the rear cover. The first limiting ring is provided between the rear cover and the floating disk and fits with the floating disk, which can limit the axial displacement of the floating disk and at the same time allow the floating disk to swing around the rotation axis of the turntable.
[0011] Furthermore, for the above-mentioned tip positioning device, an elastic second limiting ring is provided between the front cover and the floating disk. One end of the second limiting ring presses against the front cover, and the other end presses against the floating disk. The second limiting ring is provided between the front cover and the floating disk, and the elasticity of the second limiting ring generates an elastic force between the floating disk and the limiting ring, restricting the forward and backward movement of the floating disk while allowing the floating disk to swing.
[0012] Furthermore, for the above-mentioned tip positioning device, a limiting step is provided at the rear end of the first mounting hole, and a limiting boss is provided at the rear end of the driving pin. The circumferential side of the limiting boss includes a first circumferential side face and a second circumferential side face. The first circumferential side face is in sliding fit with the side face of the limiting step, and the second circumferential side face is in sliding fit with the inner wall of the first mounting hole. The limiting step can limit the circumferential rotation of the driving pin, ensuring that the driving pin always remains stable during the machining process.
[0013] Furthermore, the top positioning device is provided with a second mounting hole adjacent to each first mounting hole, and the second mounting hole is arranged in a direction parallel to the axis of the first mounting hole. A stop bolt is detachably installed in each second mounting hole. The stop bolt includes a limiting portion and a connecting portion. A limiting groove is provided on a side of the driving pin close to the stop bolt. The limiting portion is inserted into the limiting groove. The stop bolt can limit the axial displacement of the driving pin and prevent the driving pin from falling off.
[0014] Furthermore, in the above-mentioned top positioning device, the elastic mechanism includes a thrust pin, a guide tube, a plug and a pressure spring. The guide tube is connected to the rear cover along the axis direction of the top body. The rear end of the thrust pin can be slidably arranged at the front end of the guide tube, and the front end of the thrust pin abuts against the rear end of the top body. The plug is detachably arranged at the rear end of the guide tube. The pressure spring is placed in the guide tube, with one end pressing on the rear end of the thrust pin and the other end pressing on the front end of the plug. The thrust pin and the top body are coaxially arranged and abut against each other, so that there is no relative displacement between the two. During the clamping process, the top body is compressed to drive the thrust pin to move backward, causing the pressure spring to deform in the guide tube and generate elastic force, and the thrust pin transmits the elastic force generated by the deformation of the pressure spring axially to the top body.
[0015] Furthermore, in the top positioning device, the thrust pin includes a columnar main body, and the outer wall of the rear end of the main body radially expands to form a limit section. The inner wall of the front end of the guide tube radially contracts to form an annular limit step. The inner diameter of the annular limit step is smaller than the outer diameter of the limit section. The annular limit step limits the range of movement of the thrust pin in the guide tube to prevent the thrust pin from detaching from the guide tube.
[0016] Furthermore, in the aforementioned top positioning device, the center of the rear end face of the thrust pin protrudes backward to form a first boss, and the first boss extends into the end hole at the front end of the pressure spring. The center of the front end face of the plug protrudes forward to form a second boss, and the second boss extends into the end hole at the rear end of the pressure spring. The first boss and the second boss are used to limit the positions of the two ends of the pressure spring, so that the pressure spring is deformed along the axial direction of the guide tube, so that the direction of the elastic force generated by the deformation of the pressure spring remains in the axial direction.
[0017] Furthermore, in the above-mentioned center positioning device, an annular groove is provided on the inner wall of the center hole, and a rubber ring is placed in the annular groove. The inner side of the rubber ring is pressed against the outer wall of the center body. The friction force generated by the extrusion between the rubber ring and the center body prevents the center body from falling off from the center hole before clamping or after cutting.
[0018] As can be seen from the above technical solutions, the present utility model has the following beneficial effects: The center positioning device provided by the present utility model aligns the center body with the workpiece center to ensure the concentricity of both ends of the shaft-like part during the machining process. At the same time, the driving pin clamps the workpiece to complete the clamping of the workpiece. Through one-time clamping and machining, the cutting work of the shaft-like part can be completed, improving production efficiency and machining accuracy, effectively solving the problem of non-concentricity at both ends of large shafts, and ensuring product quality. In addition, the front cover and rear cover of the turntable, the thrust pin, the guide tube and the plug of the elastic mechanism, as well as the center body, the driving pin and the stop bolt all adopt detachable connection structures. The above structures are easy to disassemble and install, facilitating technicians to replace and maintain the center positioning device. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is the front view of the center positioning device;
[0020] Figure 2 is the sectional view of the center positioning device along the A-A plane in Embodiment 1;
[0021] Figure 3 is the sectional view of the turntable;
[0022] Figure 4 is the sectional view of the center positioning device along the B-B plane in Embodiment 1;
[0023] Figure 5 is the enlarged view of the floating disk and the first limit ring;
[0024] Figure 6 is the enlarged view at the driving pin;
[0025] Figure 7 is the structural schematic diagram of the driving pin;
[0026] Figure 8 is the exploded view of the elastic mechanism;
[0027] Figure 9 is the sectional view of the center positioning device along the A-A plane in Embodiment 2;
[0028] Figure 10 For Figure 9 the enlarged view at the P position in
[0029] In the figure: 1, turntable; 2, center body; 3, elastic mechanism; 4, drive pin; 11, front cover; 12, rear cover; 13, accommodation cavity; 14, floating disk; 15, first mounting hole; 16, second mounting hole; 17, annular groove; 18, rubber ring; 19, center hole; 21, first connection hole; 31, thrust pin; 32, guide tube; 33, plug; 34, compression spring; 41, stop bolt; 42, limit groove; 43, limit boss; 121, connecting rod; 122, screw; 141, first limit ring; 142, second limit ring; 143, protruding part; 144, recessed part; 145, gasket; 151, limit step; 311, main body; 312, limit section; 313, first boss; 321, annular limit step; 322, internal thread; 331, second boss; 332, spiral groove; 411, limit part; 412, connecting part; 431, first circumferential side; 432, second circumferential side. Detailed implementation manners
[0030] Embodiment 1
[0031] As Figure 1 , Figure 2 , Figure 3 shown, a center positioning device includes a turntable 1, a center body 2, an elastic mechanism 3 and six drive pins 4. A center hole 19 is provided at the center of the turntable 1, and the center hole 19 is arranged along the rotation axis direction of the turntable 1. The center body 2 is slidably installed in the center hole 19, and the front end of the center body 2 is conical. The elastic mechanism 3 is installed on the turntable 1 to apply a forward elastic force to the center body 2. On the front end face of the turntable 1, six first mounting holes 15 are arranged in a circular array around the rotation axis. The axis of each first mounting hole 15 is parallel to the axis of the turntable 1, and a drive pin 4 is slidably arranged in each first mounting hole 15. An accommodation cavity 13 communicating with the center hole 19 is provided inside the turntable 1, and a floating disk 14 is swingably installed in the accommodation cavity 13. When the drive pin 4 is pressed backward by an external force, the floating disk 14 is forced to swing adaptively.
[0032] The center positioning device in this embodiment is applicable to the scenario of precision machining of shaft parts. During clamping, the workpiece is placed between the center positioning device and the tailstock center. The center body 2 and the tailstock center are respectively aligned with the center of the workpiece. Under the action of the tightening force of the tailstock, the center body 2 is pressed backward, and the drive pin 4 starts to contact the workpiece until multiple drive pins 4 abut against the workpiece, completing the clamping.
[0033] Among them, the center body 2 positions the center of the end face of the workpiece. The elastic mechanism 3 provides a forward elastic force to the center body 2 to press the center body 2 tightly against the center of the end face of the workpiece. Multiple drive pins 4 abut against the workpiece to form a firm connection. The cooperation between the center body 2 and the drive pins 4 enables the center positioning device to finally clamp the workpiece, effectively controlling the concentricity of workpiece positioning and ensuring the machining accuracy.
[0034] In addition, the floating disk 14 allows the drive pins to axially move within the first mounting holes 15. During the clamping process, when the pressure between each drive pin 4 and the workpiece is uneven, the pressure difference causes the floating disk 14 to swing, allowing the drive pins 4 to adaptively move according to the shape of the workpiece end face, ensuring that at least three drive pins 4 are pressed against the workpiece end face.
[0035] As Figure 2 shown, the turntable 1 includes a front cover 11 and a rear cover 12, which are connected by a set of connecting rods 121. The gap between the front cover 11 and the rear cover 12 forms a receiving cavity 13. The center hole 19 is provided in the center of the front cover 11, and the first mounting holes 15 are provided on the front end face of the front cover 11. The front cover 11 and the rear cover 12 are connected by the connecting rods 121, enabling the front cover 11 and the rear cover 12 to be detachably connected, with a simple structure and easy to disassemble and install.
[0036] As Figure 4 shown, a set of screws 122 are provided on the rear cover 12, and the rear cover 12 is fixed to the chuck through the screws 122, so that the chuck drives the rear cover 12 to rotate, thereby making the center positioning device rotate. The screw connection can be easily disassembled and installed by rotating the nut, making the replacement and maintenance of the center positioning device more convenient.
[0037] As Figure 2 、 Figure 5 shown, the rear end of the floating disk 14 has a convex portion 143, and the convex portion 143 is spherical convex. A first limiting ring 141 is provided between the rear cover 12 and the floating disk 14. The front end of the first limiting ring 141 has a recessed portion 144, and the recessed portion 144 is spherical socket-shaped. The recessed portion 144 is in sliding fit with the convex portion 143. The rear end of the first limiting ring 141 presses against the rear cover 12. The first limiting ring 141 is provided between the rear cover 12 and the floating disk 14 and fits with the floating disk 14, which can limit the axial displacement of the floating disk 14 and at the same time allow the floating disk 14 to swing around the rotation axis of the turntable 1.
[0038] As Figure 2 shown, an elastic second limiting ring 142 is provided between the front cover 11 and the floating disk 14. One end of the second limiting ring 142 presses against the front cover 11, and the other end presses against the floating disk 14. The second limiting ring 142 is provided between the front cover 11 and the floating disk 14, and the second limiting ring 142 is elastic, generating an elastic force between the floating disk 14 and the second limiting ring 142, restricting the forward and backward movement of the floating disk 14 and at the same time allowing the floating disk 14 to swing.
[0039] As Figure 2As shown, a gasket 145 is provided between the first limiting ring 141 and the rear cover 12. One side of the gasket 145 presses against the front end of the rear cover 12, and the other side presses against the rear end of the first limiting ring 141. By adjusting the thickness of the gasket 145, the distance between the first limiting ring 141 and the rear cover 12 can be changed, thereby adjusting the axial position of the floating disk 14.
[0040] As Figure 6 , Figure 7 shown, a limiting step 151 is provided at the rear end of the first mounting hole 15, and a limiting boss 43 is provided at the rear end of the driving pin 4. The circumferential side of the limiting boss 43 includes a first circumferential side surface 431 and a second circumferential side surface 432. The first circumferential side surface 431 is in sliding fit with the side surface of the limiting step 151, and the second circumferential side surface 432 is in sliding fit with the inner wall of the first mounting hole 15. The limiting step 151 can limit the circumferential rotation of the driving pin 4 to ensure that the driving pin 4 always remains stable during the processing.
[0041] As Figure 3 , Figure 6 shown, a second mounting hole 16 is provided adjacent to each first mounting hole 15. The second mounting hole 16 is arranged along a direction parallel to the axis of the first mounting hole 15. A stop bolt 41 is detachably mounted in each second mounting hole 16. The stop bolt 41 includes a limiting portion 411 and a connecting portion 412. A limiting groove 42 is provided on one side of the driving pin 4 close to the stop bolt 41. The limiting portion 411 is snapped into the limiting groove 42. The stop bolt 41 can limit the axial displacement of the driving pin 4 to prevent the driving pin 4 from falling off.
[0042] As Figure 2 shown, the elastic mechanism 3 includes a thrust pin 31, a guide tube 32, a plug 33 and a compression spring 34. The guide tube 32 is connected to the rear cover 12 along the axial direction of the tip body 2. The rear end of the thrust pin 31 is slidably arranged at the front end of the guide tube 32, and the front end of the thrust pin 31 abuts against the rear end of the tip body 2. The plug 33 is detachably arranged at the rear end of the guide tube. The compression spring 34 is placed in the guide tube 32, with one end pressing against the rear end of the thrust pin 31 and the other end pressing against the front end of the plug 33. The thrust pin 31 and the tip body 2 are coaxially arranged and in mutual abutment, so that there is no relative displacement between them. During the clamping process, the tip body 2 is pressed to drive the thrust pin 31 to move backward, causing the compression spring 34 to deform in the guide tube 32 to generate an elastic force. The thrust pin 31 transmits the elastic force generated by the deformation of the compression spring 34 to the tip body 2 along the axial direction.
[0043] As Figure 8As shown in the figure, the thrust pin 31 includes a columnar main body 311, and the outer wall of the rear end of the main body 311 radially expands to form a limiting section 312. The inner wall of the front end of the guide tube 32 radially contracts to form an annular limiting step 321. The inner diameter of the annular limiting step 321 is smaller than the outer diameter of the limiting section 312. The annular limiting step 321 limits the movement range of the thrust pin 31 in the guide tube 32 and prevents the thrust pin 31 from detaching from the guide tube 32.
[0044] As Figure 8 shown in the figure, a first boss 313 protrudes rearward from the center of the rear end face of the thrust pin 31, and the first boss 313 extends into the end hole at the front end of the compression spring 34. A second boss 331 protrudes forward from the center of the front end face of the plug 33, and the second boss 331 extends into the end hole at the rear end of the compression spring 34. The first boss 313 and the second boss 331 are used to limit the positions of both ends of the compression spring 34, so that the compression spring 34 deforms along the axis direction of the guide tube 32, so that the elastic force direction generated by the deformation of the compression spring 34 remains in the axis direction.
[0045] As Figure 8 shown in the figure, a spiral groove 332 is provided on the outer wall of the plug 33, and an internal thread 322 is provided on the inner wall of the rear end of the guide tube 32. The spiral groove 332 is in threaded cooperation with the internal thread 322. During assembly, the plug 33 is screwed into the rear end of the guide tube 32, and the spiral groove 332 is in threaded cooperation with the internal thread 322, which can apply a pre-tightening force to the compression spring 34. By adjusting the screwing depth of the plug 33, the pre-tightening force of the compression spring 34 can be adjusted.
[0046] Embodiment 2
[0047] The difference from Embodiment 1 is that in this embodiment:
[0048] As Figure 9 、 Figure 10 shown in the figure, an annular groove 17 is provided on the inner wall of the center hole 19, and a rubber ring 18 is placed in the annular groove 17. The inner side of the rubber ring 18 is pressed against the outer wall of the center body 2. Friction is generated by the extrusion between the rubber ring 18 and the center body 2, preventing the center body 2 from falling off from the center hole 19 before clamping or after cutting.
Claims
1. A top positioning device, characterized in that: The invention comprises a turntable (1), a top body (2), an elastic mechanism (3) and a group of driving pins (4); a top hole (19) is arranged in the center of the turntable (1), the top hole (19) is arranged along the rotation axis direction of the turntable (1), the top body (2) is slidably mounted in the top hole (19), and the front end of the top body (2) is conical; the elastic mechanism (3) is mounted on the turntable (1) to apply a forward elastic force to the top body (2); a group of first mounting holes (15) are arranged in a circular array around the rotation axis on the front end surface of the turntable (1), the axes of the first mounting holes (15) are parallel to the axis of the turntable (1), and a driving pin (4) is slidably mounted in each of the first mounting holes (15); a receiving cavity (13) connected to the top hole is arranged inside the turntable (1), and a floating disk (14) is swingably mounted in the receiving cavity (13); when the driving pin (4) is moved backward by a backward external force, it presses the floating disk (14) to swing adaptively.
2. The top positioning device according to claim 1, characterized in that: The turntable (1) comprises a front cover (11) and a rear cover (12) which are detachably connected; the gap between the front cover (11) and the rear cover (12) forms the accommodating cavity (13); the top hole (19) is arranged at the center of the front cover (11), and the first mounting hole (15) is arranged at the front end surface of the front cover (11).
3. The top positioning device according to claim 2, characterized in that: The rear end of the floating plate (14) has a protrusion (143), and the protrusion (143) is in a spherical shape; a first limiting ring (141) is provided between the rear cover (12) and the floating plate (14); the front end of the first limiting ring (141) has a recessed portion (144), and the recessed portion (144) is in a spherical socket shape; the recessed portion (144) and the protrusion (143) are slidably matched; the rear end of the first limiting ring is pressed on the rear cover (12).
4. The top positioning device according to claim 3, characterized in that: A second elastic limiting ring (142) is provided between the front cover (11) and the floating plate (14); one end of the second limiting ring (142) is pressed on the front cover (11), and the other end is pressed on the floating plate (14).
5. The top positioning device according to claim 2, characterized in that: A limiting step (151) is provided at the rear end of the first mounting hole (15), and a limiting boss (43) is provided at the rear end of the driving pin (4); the circumferential side of the limiting boss (43) comprises a first circumferential side surface (431) and a second circumferential side surface (432); the first circumferential side surface (431) is slidably fitted with the side surface of the limiting step (151), and the second circumferential side surface (432) is slidably fitted with the inner wall of the first mounting hole (15).
6. The top positioning device according to claim 2, characterized in that: A second mounting hole (16) is provided adjacent to each of the first mounting holes (15), and the second mounting hole (16) is arranged along an axial direction parallel to the first mounting hole (15); a stopper bolt (41) is detachably installed in each of the second mounting holes (16); the stopper bolt (41) comprises a limiting portion (411) and a connecting portion (412); a limiting groove (42) is provided on a side of the driving pin (4) close to the stopper bolt (41); and the limiting portion (411) is snapped into the limiting groove (42).
7. The top positioning device according to claim 2, characterized in that: The elastic mechanism (3) comprises a thrust pin (31), a guide tube (32), a plug (33) and a pressure spring (34); the guide tube (32) is connected to the rear cover (12) along the axial direction of the top body (2); the rear end of the thrust pin (31) is slidably arranged at the front end of the guide tube (32), and the front end of the thrust pin (31) abuts against the rear end of the top body (2); the plug (33) is detachably arranged at the rear end of the guide tube (32); the pressure spring (34) is placed in the guide tube (32), one end of which is pressed against the rear end of the thrust pin (31) and the other end of which is pressed against the front end of the plug (33).
8. The top positioning device according to claim 7, characterized in that: The thrust pin (31) comprises a columnar main body (311), the outer wall of the rear end of the main body (311) radially expands to form a limiting section (312); the inner wall of the front end of the guide tube (32) radially contracts to form an annular limiting step (321); the inner diameter of the annular limiting step (321) is smaller than the outer diameter of the limiting section (312).
9. The top positioning device according to claim 7, characterized in that: The center of the rear end surface of the thrust pin (31) protrudes backwards to form a first boss (313), and the first boss (313) extends into the end hole at the front end of the pressure spring (34); the center of the front end surface of the plug (33) protrudes forwards to form a second boss (331), and the second boss (331) extends into the end hole at the rear end of the pressure spring (34).
10. The top positioning device according to claim 2, characterized in that: An annular groove (17) is provided on the inner wall of the top hole (19), and a rubber ring (18) is placed in the annular groove (17); the inner side of the rubber ring (18) is pressed against the outer wall of the top body (2).