A sewing machine shaft sleeve positioning and clamping mechanism

Abstract

The present application relates to the technical field of mechanical manufacturing, and particularly relates to a sewing machine shaft sleeve positioning and clamping mechanism. The positioning device pulls the pull ring through the pull rod, the cylindrical outer expansion structure is axially pulled back and radially deformed at the matching taper position, so that the cylindrical outer expansion structure is elastically deformed, at this time, the diameter of the cylindrical outer expansion structure is increased to automatically position the shaft sleeve, the clamping position of the shaft sleeve can be finely adjusted at the same time of being pulled back, and the positioning accuracy is ensured. The clamping mechanism adopts a rear pulling clamping mode, the chuck inclined column is axially pulled back at the same time, the radial position of the clamping jaw is reduced, and the workpiece is clamped, the workpiece is clamped at the same time and is axially pulled back, so that the end face of the workpiece is tightly attached to the positioning surface, and the workpiece has high perpendicularity and high parallelism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical manufacturing, in particular to a sewing machine shaft sleeve positioning and clamping mechanism. BACKGROUND

[0002] Sewing machine shaft sleeve processing refers to a series of process flows of processing raw materials into shaft parts, and the first step before processing the raw materials is clamping, and the processing personnel will use a three-jaw chuck to clamp the workpiece, and then use the cutter on the lathe to cut the workpiece;

[0003] At present, the clamping method of the sewing machine shaft sleeve processing adopts a three-jaw chuck for clamping, and the shaft sleeve is clamped in the three-jaw chuck during the clamping process, and the position of the jaw teeth is adjusted to fix the shaft sleeve. This clamping method is simple and easy to operate, and is suitable for the processing of some simple shaped shaft sleeves. However, the precision of the three-jaw chuck is limited, and the clamping force is uneven due to the gap and elasticity between the clamping jaws when the three-jaw chuck clamps the shaft sleeve, which can easily cause the eccentricity or non-parallelism of the shaft sleeve, thereby affecting the processing precision and leading to a decrease in processing quality.

[0004] In view of the above situation, in order to overcome the above technical problems, the present application designs a case name, which solves the above technical problems. SUMMARY

[0005] The technical problem to be solved by the present application is that the existing clamping method of the sewing machine shaft sleeve processing adopts a three-jaw chuck for clamping, and the clamping force is uneven due to the gap and elasticity between the clamping jaws when the three-jaw chuck clamps the shaft sleeve, which can easily cause the eccentricity or non-parallelism of the shaft sleeve, thereby affecting the processing precision.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The sewing machine shaft sleeve positioning and clamping mechanism provided by the present application comprises a support, a clamping assembly and a positioning assembly, the clamping assembly is installed on the support, the clamping assembly adopts a rear pulling clamping method, clamps the workpiece while having an axial rear pulling action, makes the end face of the workpiece tightly adhere to the positioning surface, so as to ensure that the workpiece has high perpendicularity and high parallelism, and avoid the vibration and displacement of the workpiece, the positioning assembly is installed in the middle of the clamping assembly, the positioning assembly can realize automatic positioning of the workpiece through an outward expansion structure, and has a rear pulling action while the positioning assembly expands outward, can finely adjust the clamping position of the workpiece, and make the workpiece in the processing position.

[0008] Preferably, the positioning assembly comprises a cylindrical mounting seat, a pull rod, a slide column, a guide column, a pull ring, a cylindrical expansion structure and a fixing sleeve, the cylindrical mounting seat is fixedly installed in the middle of the clamping assembly, the pull rod is "middle" shaped, the pull rod is slidably installed in the inside of the cylindrical mounting seat and is used to link the clamping assembly and the positioning assembly by the "middle" shaped structure, the lower end surface of the guide column is fixedly installed on the upper surface of the cylindrical mounting seat, the lower end of the guide column is slidably installed with the pull ring used for transmitting power, the slide column is installed between the pull rod and the pull ring, the upper end of the guide column is slidably installed with the cylindrical expansion structure used for positioning by elastic deformation, the fixing sleeve is fixedly installed on the outside of the cylindrical expansion structure, the bottom surface of the fixing sleeve is fixedly installed on the upper surface of the cylindrical mounting seat, the inner wall of the cylindrical expansion structure and the outer wall of the conical guide column are attached during installation, which can ensure the installation accuracy, avoid cutting debris from entering the cylindrical expansion structure, reduce scratches and damage, and improve the service life of the mechanism, the installation holes are six in total, and the interval angle value of the installation holes in the circumferential direction is 60°, six installation holes are used here to increase the stability and balance of the positioning assembly, the installation holes are evenly distributed on the circumference, and the angles between them are equal, which can make the shaft sleeve be uniformly stressed during work, prevent uneven wear or deformation of the shaft sleeve during installation, and improve the rigidity and carrying capacity of the positioning assembly.

[0009] Preferably, the guide column comprises a bottom column and a conical column, the pull ring is slidably installed on the bottom column, the pull ring is spaced apart from the bottom surface of the bottom column to fine-tune the position of the shaft sleeve workpiece clamping, the conical column is fixedly installed on the upper surface of the bottom column, and the top surface of the conical column is coplanar with the top surface of the cylindrical expansion structure to accurately control the size of the elastic deformation of the cylindrical expansion structure at the matching taper position, which can cooperate with the work of the cylindrical expansion structure, facilitate the installation and disassembly of the cylindrical expansion structure, and the existence of the taper can disperse the cutting force and prolong the service life of the conical guide column.

[0010] Preferably, the pull ring comprises a matching ring, a connecting ring and an arc-shaped boss, the matching ring is fixedly installed on the upper surface of the connecting ring, there are six arc-shaped bosses arrayed along the circumferential direction of the upper surface of the matching ring, and the interval angle value of the arc-shaped bosses in the circumferential direction is 60°, the outer wall of the arc-shaped boss is arc-shaped and will not interfere with the inner surface of the cylindrical expansion structure during installation, the design herein can facilitate the installation of the cylindrical expansion structure by evenly distributing the arc-shaped bosses on the circumference and making the angles between them equal.

[0011] Preferably, the cylindrical outer expansion structure comprises a matching bottom ring, a rectangular protrusion, a cylindrical expansion sleeve, a hollow tapered hole and a filling groove, the matching bottom ring is buckled on the outside of the matching ring, the inside of the matching bottom ring is provided with a rectangular protrusion for matching the arc-shaped boss, the rectangular protrusion has six and is arrayed along the ring, the included angle between the center lines of two adjacent rectangular protrusions is 60°, the inner wall of the rectangular protrusion is arc-shaped for matching the outer surface of the pull ring, the cylindrical expansion sleeve is fixedly installed on the upper surface of the matching bottom ring, the inside of the cylindrical expansion sleeve is a hollow tapered hole, and six filling grooves are opened on the circumferential surface of the cylindrical expansion sleeve for controlling the size of the radial force generated by the cylindrical outer expansion structure at the matching tapered surface position. The design here can facilitate the installation of the cylindrical outer expansion structure by uniformly distributing the rectangular protrusions on the circumference and making the angles between them equal, and the cylindrical outer expansion structure is uniformly stressed during matching. The filling groove is filled with rubber. The design here is to adjust and compensate the radial deformation generated during the expansion process, so that the workpiece is uniformly stressed. On the one hand, rubber can withstand sufficient elastic deformation, and on the other hand, rubber filling also has good sealing performance, which can prevent cutting debris from entering the inside of the cylindrical expansion sleeve and protect the normal operation of the structure. The outer surface of the cylindrical expansion sleeve is made of HRC60 vulcanized rubber material. The hardness of HRC60 vulcanized rubber is very high, which has excellent wear resistance and friction resistance, can effectively reduce the friction and wear between the cylindrical expansion sleeve and the workpiece, prolong the service life of the expansion sleeve, and the vulcanized rubber has good elasticity and plasticity, which can form a good seal when contacting with the workpiece to prevent cutting debris from entering the inside of the cylindrical expansion sleeve.

[0012] Preferably, the outer surface of the matching ring is inverted "L" shaped, the inner surface of the matching bottom ring is "L" shaped, and the "L" shaped inner surface of the matching bottom ring tightly fits with the inverted "L" shaped outer surface of the matching ring during matching to realize the same frequency movement of the pull rod and the cylindrical outer expansion structure. This design is to avoid cutting debris entering the cylindrical outer expansion structure, reduce scratching and damage, and improve the service life of the mechanism. On the other hand, it is to ensure the installation accuracy.

[0013] Preferably, the clamping assembly comprises a cylindrical chuck, a chuck inclined column, a clamp, a base plate and a limiting groove, the cylindrical chuck is installed on the support, the inside of the cylindrical chuck is slidably installed with a chuck inclined column for providing power to the clamping assembly, the clamp is fixedly installed on the upper end face of the chuck inclined column, the base plate is fixedly installed on the lower end of the cylindrical chuck, and the limiting groove is opened on the upper end face of the base plate to control the axial displacement distance of the chuck inclined column. The pull rod is slidably installed in the inside of the cylindrical chuck. This design can convert the axial tension of the pull rod into the radial clamping force of the clamp.

[0014] Preferably, the chuck inclined column lower end is provided with a sliding groove for converting the axial tension of the pull rod into the radial clamping force of the clamp, the inner wall of the sliding groove is arc-shaped, and interference with the sliding groove will not occur when the pull rod moves to the limit position, the chuck inclined column has three, the interval angle value of the three chuck inclined columns in the circumferential direction of the cylindrical chuck is 120°, the interval angle value of the chuck inclined columns is 120°, the workpiece can be fixed on three points on the cylindrical chuck, the contact area between the workpiece and the cylindrical chuck is increased, better fixing stability is provided, the vibration and displacement of the workpiece during machining are reduced, and the machining precision and quality are ensured, the chuck inclined column is made of HRC60 carburized steel, the HRC60 carburized steel has high hardness and strength, can provide better carrying capacity and durability, the HRC60 carburized steel has a certain elasticity, can play a buffering and shock-absorbing role, and the stability and working efficiency of the chuck inclined column are improved.

[0015] The beneficial effects of the present application are as follows:

[0016] 1. The sewing machine shaft sleeve positioning and clamping mechanism, the upper end of the pull rod is slidably connected in the positioning assembly, the cylindrical outer swelling structure is axially pulled back and radially deformed at the matching taper position, automatic positioning of the workpiece can be realized, the other end of the pull rod is slidably connected in the clamping assembly, the chuck inclined column is axially pulled back, the radial position of the clamping jaw is reduced, and the workpiece is clamped, so that the workpiece has high perpendicularity and high parallelism.

[0017] 2. The sewing machine shaft sleeve positioning and clamping mechanism, the positioning device pulls back the pull ring through the pull rod, the cylindrical outer swelling structure is axially pulled back and radially deformed at the matching taper position, so that the cylindrical outer swelling structure is elastically deformed, the diameter of the cylindrical outer swelling structure is increased to automatically position the shaft sleeve, the clamping position of the shaft sleeve can be fine-tuned while being pulled back, and the positioning accuracy is ensured.

[0018] 3. The sewing machine shaft sleeve positioning and clamping mechanism, the clamping assembly adopts a back-pulling clamping mode, the chuck inclined column is axially pulled back, the radial position of the clamping jaw is reduced, and the workpiece is clamped, the pull rod drives the chuck inclined column to be axially pulled back while clamping the workpiece, the end face of the workpiece is tightly attached to the positioning surface, so that the workpiece has high perpendicularity and high parallelism. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0020] The above and other aspects of the present application will now be described, by way of example only, with reference to the accompanying drawings in which:

[0021] Figure 1 is a schematic view of the present application;

[0022] Figure 2 is a schematic view of the positioning and clamping assembly of the present application;

[0023] Figure 3 is a sectional view of the present application in the direction of A-A; Figure 2

[0024] Figure 4 is a schematic view of the positioning assembly of the present application;

[0025] Figure 5 is a front view of the present application based on Figure 4

[0026] Figure 6 is a sectional view of the present application in the direction of B-B; Figure 5

[0027] Figure 7 is a parts view of the cylindrical mounting base of the present application based on Figure 4

[0028] Figure 8 is a top view of the present application based on Figure 7

[0029] Figure 9 is a front view of the present application based on Figure 7

[0030] Figure 10 is a sectional view of the present application in the direction of C-C; Figure 9

[0031] Figure 11 is a parts view of the pull ring of the present application based on Figure 4

[0032] Figure 12 is a front view of the present application based on Figure 11

[0033] Figure 13 is a sectional view of the present application in the direction of D-D; Figure 12

[0034] Figure 14 is a parts view of the cylindrical expansion structure of the present application based on Figure 4

[0035] Figure 15 is a front view of the present application based on Figure 14 ​​​​​​​​​​​​

[0036] Figure 16 is the application in Figure 15 the E-E direction sectional view;

[0037] Figure 17 is the application in Figure 15 the F-F direction sectional view.

[0038] In the figure: 1, support; 2, clamping assembly; 3, positioning assembly; 31, cylindrical mounting seat; 32, pull rod; 33, sliding column; 34, guide column; 35, pull ring; 36, cylindrical outer expansion structure; 37, fixed sleeve; 341, bottom column; 342, conical column; 351, matching ring; 352, connecting ring; 353, arc-shaped boss; 361, matching bottom ring; 362, rectangular protrusion; 363, cylindrical expansion sleeve; 364, hollow taper hole; 365, filling groove; 21, cylindrical chuck; 22, chuck inclined column; 23, clamp; 24, base plate; 25, limiting groove; 221, sliding groove. DETAILED DESCRIPTION

[0039] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the drawings and specific embodiments of the specification.

[0040] Example 1: As shown in Figure 1 , a sewing machine shaft sleeve positioning and clamping mechanism, comprising a support 1, a clamping assembly 2 and a positioning assembly 3, the clamping assembly 2 is installed on the support 1, the clamping assembly 2 adopts a rear-pulling clamping method, clamping the workpiece while pulling it axially backward, so that the end face of the workpiece is tightly attached to the positioning surface, to ensure that the workpiece has high perpendicularity and high parallelism, and to avoid vibration and displacement of the workpiece, the positioning assembly 3 is installed in the middle of the clamping assembly 2, the positioning assembly 3 can realize automatic positioning of the workpiece through the outer expansion structure, and also has a rear-pulling action while the positioning assembly 3 is expanding, which can fine-tune the clamping position of the workpiece and make the workpiece in the processing position.

[0041] As Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the positioning assembly 3 includes a cylindrical mounting seat 31, a pull rod 32, a sliding column 33, a guide column 34, a pull ring 35, a cylindrical expansion structure 36, and a fixing sleeve 37. The cylindrical mounting seat 31 is fixedly installed at the middle part of the clamping assembly 2. The pull rod 32 is in a "middle" shape. The pull rod 32 is slidably installed in the cylindrical mounting seat 31 and is linked with the clamping assembly 2 and the positioning assembly 3 by using the "middle" shape structure. The lower end surface of the guide column 34 is fixedly installed on the upper surface of the cylindrical mounting seat 31. The lower end of the guide column 34 is slidably installed with the pull ring 35 for transmitting power. The sliding column 33 is installed between the pull rod 32 and the pull ring 35. The upper end of the guide column 34 is slidably installed with the cylindrical expansion structure 36 for positioning by elastic deformation. The fixing sleeve 37 is fixedly installed on the outside of the cylindrical expansion structure 36. The bottom surface of the fixing sleeve 37 is fixedly installed on the upper surface of the cylindrical mounting seat 31. The inner wall of the cylindrical expansion structure 36 and the outer wall of the conical guide column are attached during installation. This ensures the installation precision and avoids cutting debris from entering the cylindrical expansion structure 36, reducing scratches and damage, and improving the service life of the mechanism. There are six installation holes, and the installation holes are spaced at an angle of 60° in the circumferential direction. Six installation holes are used to increase the stability and balance of the positioning assembly 3. By evenly distributing the installation holes on the circumference and making the angles between them equal, the shaft sleeve can be uniformly stressed during installation, preventing uneven wear or deformation of the shaft sleeve during installation. In addition, this angular distribution design can also improve the rigidity and carrying capacity of the positioning assembly 3.

[0042] During operation, the pull rod 32 is axially pulled back to pull the sliding column 33 back, and then the pull ring 35 pulls the cylindrical expansion structure 36 axially back. At this time, the cylindrical expansion structure 36 is axially pulled back and radially deformed at the matching taper position of the conical guide column, so that the cylindrical expansion structure 36 is elastically deformed. At this time, the diameter of the cylindrical expansion structure 36 increases to support and automatically position the shaft sleeve. The clamping position of the shaft sleeve can be adjusted at the same time, ensuring the positioning accuracy.

[0043] Compared with the existing three-jaw chuck, the three-jaw chuck uses mechanical force to lock the shaft sleeve, which has certain positioning error and slight swing. This inaccurate positioning may cause axial deviation of the workpiece during machining, affecting the machining precision and quality. The positioning assembly 3 adopted in the design uses the cylindrical expansion structure 36 to support and automatically position the workpiece by expansion operation, ensuring the accurate positioning of the shaft sleeve. This positioning method can avoid the shift of the shaft sleeve during cutting or machining, ensuring the accurate machining of the workpiece.

[0044] As Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, the guide column 34 includes a bottom column 341 and a conical column 342, the pull ring 35 is slidingly installed on the bottom column 341, and the pull ring 35 is kept a certain distance from the bottom surface of the bottom column 341 for fine adjustment of the position of the sleeve workpiece clamping, and the conical column 342 is fixedly installed on the upper surface of the bottom column 341, and the top surface of the conical column 342 is coplanar with the top surface of the cylindrical expansion structure 36 to accurately control the size of the elastic deformation of the cylindrical expansion structure 36 at the matching conical surface position. Such design can match the work of the cylindrical expansion structure 36, facilitate the installation and disassembly of the cylindrical expansion structure 36, and the existence of the conical surface can disperse the cutting force and prolong the service life of the conical guide column.

[0045] As shown in Figure 11 , Figure 12 and Figure 13 , the pull ring 35 includes a matching circular ring 351, a connecting circular ring 352, and an arc-shaped boss 353, the matching circular ring 351 is fixedly installed on the upper surface of the connecting circular ring 352, the arc-shaped boss 353 is arrayed in the circumferential direction of the upper surface of the matching circular ring 351, there are 6 arc-shaped bosses 353, and the interval angle of the arc-shaped bosses 353 in the circumferential direction is 60°, the outer wall of the arc-shaped boss 353 is a circular arc, which will not interfere with the inner surface of the cylindrical expansion structure 36 during installation, and the design here can facilitate the installation of the cylindrical expansion structure 36 by uniformly distributing the arc-shaped bosses 353 on the circumference and making the angle between them equal, and the cylindrical expansion structure 36 is uniformly stressed during matching.

[0046] As shown in Figure 14 , Figure 15 , Figure 16 and Figure 17As shown, the cylindrical outward expansion structure 36 includes a matching bottom ring 361, rectangular protrusions 362, a cylindrical expansion sleeve 363, a hollow tapered hole 364, and filling grooves 365. The matching bottom ring 361 is snap-connected to the outside of the matching circular ring 351. The inside of the matching bottom ring 361 is provided with rectangular protrusions 362 for matching the arc-shaped protrusions 353. There are six rectangular protrusions 362 arranged in an array along the circular ring, and the included angle between the center lines of two adjacent rectangular protrusions 362 is 60°. The inner wall of the rectangular protrusions 362 is arc-shaped for matching the outer surface of the pull ring 35. The cylindrical expansion sleeve 363 is fixedly installed on the upper surface of the matching bottom ring 361. The inside of the cylindrical expansion sleeve 363 is a hollow tapered hole 364. Six filling grooves 365 are formed on the circumferential surface of the cylindrical expansion sleeve 363 for controlling the size of the radial force generated by the cylindrical outward expansion structure 36 at the matching tapered surface position. The design herein uniformly distributes the rectangular protrusions 362 on the circumference and makes the angle between them equal, which facilitates the installation of the cylindrical outward expansion structure 36 and uniformly applies force during matching. The filling grooves 365 are filled with rubber. The design herein is to adjust and compensate for the radial deformation generated during the outward expansion process, so that the workpiece is uniformly stressed. On the one hand, rubber can withstand sufficient elastic deformation. On the other hand, rubber filling also has good sealing performance, which can prevent cutting debris from entering the inside of the cylindrical expansion sleeve 363 and protect the normal operation of the structure. The outer surface of the cylindrical expansion sleeve 363 is made of HRC60 vulcanized rubber material. HRC60 vulcanized rubber has very high hardness, excellent wear resistance and friction resistance, which can effectively reduce the friction and wear between the cylindrical expansion sleeve 363 and the workpiece, prolong the service life of the expansion sleeve, and vulcanized rubber has good elasticity and plasticity, which can form a good seal when in contact with the workpiece to prevent cutting debris from entering the inside of the cylindrical expansion sleeve 363.

[0047] During operation, the positioning assembly 3 pulls the pull ring 35 backward through the pull rod 32, causing the cylindrical outward expansion structure 36 to axially pull backward and radially deform at the matching tapered surface position, so that the cylindrical outward expansion structure 36 elastically deforms. At this time, the diameter of the cylindrical outward expansion structure 36 increases to automatically position the shaft sleeve. The positioning assembly 3 pushes the pull ring 35 forward through the pull rod 32, causing the cylindrical outward expansion structure 36 to move forward. At this time, the cylindrical outward expansion structure 36 returns to its original size.

[0048] Compared with the existing three-jaw chuck, the positioning of the three-jaw chuck mainly relies on the contact between the claw teeth and the outer circle, and is affected by factors such as machining precision and claw tooth wear, so the positioning precision is not high enough. The cylindrical outer expansion structure 36 is in contact with the inner wall of the shaft sleeve part to achieve automatic positioning of the shaft sleeve part. The cylindrical outer expansion structure 36 is made of HRC60 vulcanized rubber material, which has very high hardness and can form a good seal when in contact with the workpiece, preventing cutting debris from entering the inside of the cylindrical expansion sleeve 363, and achieving high positioning precision.

[0049] As shown in Figure 3 , Figure 6 and Figure 11 , the outer surface of the matching ring 351 is inverted "L" shaped, the inner surface of the matching bottom ring 361 is "L" shaped, and the "L" shaped inner surface of the matching bottom ring 361 tightly fits with the inverted "L" shaped outer surface of the matching ring 351 when matched to achieve the same frequency movement of the pull rod 32 and the cylindrical outer expansion structure 36. This design avoids cutting debris from entering the cylindrical outer expansion structure 36, reduces scratching and damage, and improves the service life of the mechanism. On the other hand, it ensures the precision of installation.

[0050] When working, the inverted "L" shaped outer structure of the matching ring 351 cooperates with the "L" shaped inner structure of the matching bottom ring 361 in the cylindrical outer expansion structure 36. When the pull rod 32 is pulled axially backward, the slide column 33 fixedly connected with the connecting ring 352 drives the pull ring 35 to pull axially backward. At this time, the pull ring 35 drives the cylindrical outer expansion structure 36 cooperating therewith to pull axially backward.

[0051] Compared with the existing matching method, the existing matching method is difficult to disassemble. The "L" shaped clamping method used in the design ensures the precision of the matching and is simple to disassemble.

[0052] As shown in Figure 2 and Figure 3 , the clamping assembly 2 includes a cylindrical chuck 21, a chuck inclined column 22, a clamp 23, a bottom disc 24, and a limiting groove 25. The cylindrical chuck 21 is installed on the support 1. The cylindrical chuck 21 has a chuck inclined column 22 installed inside for providing power to the clamping assembly 2. The clamp 23 is fixedly installed on the upper end face of the chuck inclined column 22. The bottom disc 24 is fixedly installed on the lower end of the cylindrical chuck 21. The limiting groove 25 is provided on the upper end face of the bottom disc 24 to control the axial displacement distance of the chuck inclined column 22. The pull rod 32 is slidably installed inside the cylindrical chuck 21. This design can convert the axial pulling force of the pull rod 32 into the radial clamping force of the clamp 23.

[0053] When working, the chuck inclined column 22 is axially pulled back and the radial position is reduced, so as to clamp the positioned workpiece, and the chuck inclined column 22 is axially pushed forward and the radial position is increased, so as to release the clamped workpiece.

[0054] Compared with the existing three-jaw chuck, the working principle of the three-jaw chuck is to fix the workpiece by clamping, and the workpiece is prone to bending deformation or instability during machining, which affects the machining quality. The clamping mode adopted by the design is the rear pulling type. The clamping assembly 2 of the design realizes clamping by pulling the workpiece outward through the rear pulling cylindrical chuck 21, can uniformly distribute the clamping force, and reduce deformation and vibration.

[0055] As shown in Figure 2 Figure 3 The lower end of the chuck inclined column 22 is provided with a sliding groove 221 for converting the axial pulling force of the pull rod 32 into the radial clamping force of the clamp 23. The inner wall of the sliding groove 221 is arc-shaped, and when the pull rod 32 moves to the limit position, it will not interfere with the sliding groove 221. There are three chuck inclined columns 22, and the interval angle value of the three chuck inclined columns 22 in the circumferential direction of the cylindrical chuck 21 is 120°. The interval angle value of the chuck inclined column 22 is 120°, which can fix the workpiece on three points on the cylindrical chuck 21, increase the contact area between the workpiece and the cylindrical chuck 21, and provide better fixing stability. This can reduce the vibration and displacement of the workpiece during machining, ensure the machining precision and quality, and the chuck inclined column 22 is made of HRC60 carburized steel. HRC60 carburized steel has high hardness and strength, can provide better carrying capacity and durability, and has a certain elasticity, which can play a buffering and damping role, improve the stability and working efficiency of the chuck inclined column 22.

[0056] When working, the pull rod 32 is axially pulled back, the outer convex circular ring of the pull rod 32 drives the chuck inclined column 22 to be axially pulled back in the chuck inclined hole while the radial position is reduced, and the pull rod 32 is axially pushed forward. The outer convex circular ring of the pull rod 32 drives the chuck inclined column 22 to be axially pushed forward in the chuck inclined hole while the radial position is increased.

[0057] Compared with the existing three-jaw chuck, when the cutting force acts on the shaft sleeve workpiece, the cutting force is uniformly distributed on the three inclined columns through the support of the chuck inclined column 22, thereby improving the stability of the workpiece and reducing the vibration and deformation of the workpiece. And HRC60 carburized steel has very high strength and can withstand large force and wear, prolonging the service life.

[0058] In the working process of the present application, the worker first installs the shaft sleeve part on the positioning assembly 3, the positioning assembly 3 pulls the pull ring 35 through the pull rod 32, the cylindrical outer expansion structure 36 is axially pulled back and radially deformed at the matching taper position, so that the cylindrical outer expansion structure 36 is elastically deformed, at this time the diameter of the cylindrical outer expansion structure 36 increases to support and automatically position the shaft sleeve, the clamping assembly 2 pulls the pull rod 32 axially, the chuck inclined column 22 is axially pulled back in the chuck inclined hole while the radial position is reduced, so as to clamp the positioned workpiece, at this time the shaft sleeve part to be machined has completed positioning and clamping, after machining, the clamping assembly 2 pushes the pull rod 32 axially, the chuck inclined column 22 is axially pushed forward in the chuck inclined hole while the radial position is increased, so as to release the clamped workpiece, the positioning assembly 3 pushes the pull ring 35 through the pull rod 32, the cylindrical outer expansion structure 36 moves forward, at this time the cylindrical outer expansion structure 36 restores the original size, waiting for the worker to take out the shaft sleeve part. The above disclosed technical features are not limited to the disclosed combinations with other features, and those skilled in the art can also make other combinations between technical features according to the purpose of disclosure, so as to achieve the purpose of the present application.

[0059] The description herein is provided to enable those skilled in the art to realize or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sewing machine bushing positioning and clamping mechanism comprising a support (1), characterized in that, It also includes clamping assembly (2) and positioning assembly (3), the positioning assembly (3) is installed in the middle part of clamping assembly (2); The positioning assembly (3) includes cylindrical mounting seat (31), pull rod (32), slide column (33), guide column (34), pull ring (35), cylindrical expansion structure (36) and fixed sleeve (37), the cylindrical mounting seat (31) is fixedly installed in the middle part of clamping assembly (2), the pull rod (32) is "middle" shape, the inside of the cylindrical mounting seat (31) is slidably installed with the pull rod (32) which is linked with clamping assembly (2) and positioning assembly (3) by using the "middle" shape structure characteristics, the lower end surface of the guide column (34) is fixedly installed on the upper surface of the cylindrical mounting seat (31), the lower end of the guide column (34) is slidably installed with the pull ring (35) for power transmission, the slide column (33) is installed between the pull rod (32) and the pull ring (35), the upper end of the guide column (34) is slidably installed with the cylindrical expansion structure (36) which realizes positioning by elastic deformation, the fixed sleeve (37) is fixedly installed on the outside of the cylindrical expansion structure (36), and the bottom surface of the fixed sleeve (37) is fixedly installed on the upper surface of the cylindrical mounting seat (31), the inner wall of the cylindrical expansion structure (36) and the outer wall of the guide column (34) are matched to avoid cutting debris entering the cylindrical expansion structure (36); The cylindrical expansion structure (36) includes matching bottom ring (361), rectangular protrusion (362), cylindrical expansion sleeve (363), hollow tapered hole (364) and filling groove (365); The guide column (34) includes bottom column (341) and conical column (342), the pull ring (35) is slidably installed on the bottom column (341), the pull ring (35) is kept a certain distance from the bottom surface of the bottom column (341) for the cylindrical expansion structure (36) to adapt to different radial deformation, the conical column (342) is fixedly installed on the upper surface of the bottom column (341), the existence of the conical surface can disperse the cutting force, the top surface of the conical column (342) is coplanar with the top surface of the cylindrical expansion structure (36) to accurately control the size of the elastic deformation of the cylindrical expansion structure (36) at the matching tapered surface position; The clamping assembly (2) includes cylindrical chuck (21), chuck inclined column (22), clamp (23), chassis (24) and limiting groove (25), the cylindrical chuck (21) is installed on the support (1), the inside of the cylindrical chuck (21) is slidably installed with the chuck inclined column (22) for providing power to the clamping assembly (2), the clamp (23) is fixedly installed on the upper end surface of the chuck inclined column (22), the chassis (24) is fixedly installed on the lower end of the cylindrical chuck (21), the limiting groove (25) is opened on the upper end surface of the chassis (24) to control the axial displacement distance of the chuck inclined column (22), the pull rod (32) is slidably installed in the inside of the cylindrical chuck (21); The chuck inclined column (22) is made of carburizing steel material with HRC60; the outer surface of the cylindrical expansion sleeve (363) is made of vulcanized rubber material with HRC60; The pull ring (35) comprises a matching ring (351), a connecting ring (352) and an arc-shaped boss (353), the matching ring (351) is fixedly installed on the upper surface of the connecting ring (352), the arc-shaped boss (353) is arrayed with six along the circumferential direction of the upper surface of the matching ring (351), and the interval angle of the arc-shaped boss (353) in the circumferential direction is 60°, and the outer wall of the arc-shaped boss (353) is a circular arc which will not interfere with the inner surface of the cylindrical expansion structure (36) during installation. The matching bottom ring (361) is buckled to the outside of the matching ring (351), the inside of the matching bottom ring (361) is provided with a rectangular boss (362) for matching the arc-shaped boss (353), the rectangular boss (362) is arrayed with six along the circular ring, the included angle between the center lines of two adjacent rectangular bosses (362) is 60°, the inner wall of the rectangular boss (362) is a circular arc for matching the outer surface of the pull ring (35), the cylindrical expansion sleeve (363) is fixedly installed on the upper surface of the matching bottom ring (361), the inside of the cylindrical expansion sleeve (363) is a hollow taper hole (364), and six filling grooves (365) are arranged on the circumferential surface of the cylindrical expansion sleeve (363) for controlling the radial force generated by the cylindrical expansion structure (36) at the matching taper position. The clamping assembly (2) is installed on the support (1), the clamping assembly (2) pulls the chuck inclined column (22) through the pull rod (32) to reduce the radial distance of the clamp (23), so that the shaft sleeve end surface is tightly attached to the positioning surface while clamping the workpiece; the positioning assembly (3) pulls the pull ring (35) through the pull rod (32) to realize the positioning of the shaft sleeve by the axial backward pulling and radial deformation of the cylindrical expansion structure (36) at the matching taper position.

2. The mechanism according to claim 1, wherein: The outer surface of the matching ring (351) is a reverse "L" shape, the inner surface of the matching bottom ring (361) is an "L" shape, and the "L" shaped inner surface of the matching bottom ring (361) is tightly attached to the reverse "L" shaped outer surface of the matching ring (351) during matching to realize the same frequency movement of the pull rod (32) and the cylindrical expansion structure (36).

3. The mechanism according to claim 1, wherein: The lower end of the chuck inclined column (22) is provided with a sliding groove (221) for converting the axial pulling force of the pull rod (32) into the radial clamping force of the clamp (23), and the inner wall of the sliding groove (221) is a circular arc which will not interfere with the sliding groove (221) when the pull rod (32) moves to the limit position.

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