Positioning tool for grinding thin-wall workpiece

Abstract

The utility model provides a positioning tool for grinding a thin-wall workpiece. The positioning tool comprises a mandrel, an expansion sleeve and a locking nut, one end of the mandrel is provided with a conical stop block matched with the inner diameter of a thin-wall workpiece to be ground, the other end of the mandrel is provided with a threaded section matched with the locking nut, the locking nut is arranged on the threaded section of the mandrel, and the threaded section is provided with scale marks corresponding to the opening diameter of the expansion sleeve. A conical ring is arranged on the core shaft between the conical baffle block and the threaded section; the outer conical surface of the conical ring abuts against the inner conical surface of the expansion sleeve, and the expansion sleeve can move in the axial direction of the mandrel by rotating the locking nut. The scale corresponding to the expansion diameter of the expansion sleeve is arranged at one end, close to the locking nut, of the central shaft, so that the moving distance of the locking nut is controlled, the expansion diameter of the expansion sleeve can be accurately controlled, and a machined workpiece is prevented from being damaged due to the fact that the expansion diameter is too large.

Description

Technical Field

[0001] The utility model relates to the field of processing, in particular to a positioning tool for grinding thin-walled workpieces. Background Art

[0002] Cylindrical thin-walled parts are widely used in the mechanical field and are also recognized as one of the difficult-to-machine parts. Since the difference between the inner and outer diameters of this type of workpiece is relatively small, thin-walled parts are generally clamped by a mandrel or directly clamped by a three-jaw chuck during lathe processing. The workpiece also needs to be aligned after clamping, so the processing efficiency is low and deformation is easily caused during clamping.

[0003] Prior art CN202110949636.0 discloses a thin-walled copper bushing processing and positioning tool, including an outer circle positioning component and an inner hole tensioning component; the outer circle positioning component includes a ferrule body and a clamping nut, the ferrule body is a stepped shaft, the large end of the ferrule body is provided with a cylindrical groove with the same diameter as the outer diameter of the copper bushing, the length of the cylindrical groove is less than the length of the copper bushing, the locking nut is threadedly connected to the large end of the ferrule body, and the copper bushing is locked in the cylindrical groove; the inner hole tensioning component The parts include a mandrel, a positioning sleeve and a positioning nut. The mandrel is a stepped shaft, including a connecting section, a limiting section, a tensioning section and a screw section connected in sequence. The positioning sleeve is composed of multiple groups of L-shaped tensioning plates. The tensioning section is a truncated cone with the large end facing the limiting section. The long side of the L-shaped tensioning plate is provided with an inclined surface used in conjunction with the tensioning section. The outer surface of the positioning nut is provided with an annular groove used in conjunction with the short side of the L-shaped tensioning plate. The positioning nut is threadedly connected to the screw section. The long side of the L-shaped tensioning plate is used to support the copper bushing. Although the invention realizes the positioning processing of the thin wall of the cylinder through the inner hole tensioning component, the following problems still exist:

[0004] 1. When tightening the nut, there is no reference for the tightening distance of the nut. Due to the ductility of the metal, it is easy to cause the inner diameter of the cylinder to become larger or cause the expansion sleeve to break through the thin wall of the cylinder, affecting the structural accuracy and efficiency.

[0005] 2. The versatility of the tooling is limited. It is designed mainly for thin-walled cylinders of specific sizes. For thin-walled cylinders of different diameters, lengths or other materials, the tooling may need to be redesigned or adjusted, which is not conducive to rapid changeover on the production line and adapting to diversified production needs. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a positioning tool for grinding thin-walled workpieces. By setting a scale corresponding to the opening diameter of the expansion sleeve at one end of the center axis close to the locking nut, the moving distance of the locking nut can be controlled, so that the opening diameter of the expansion sleeve can be accurately controlled to prevent it from being too large to damage the processed workpiece.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] Provided is a positioning tool for grinding thin-walled workpieces, comprising: a mandrel, an expansion sleeve, and a locking nut;

[0009] One end of the core shaft is provided with a conical stopper matching the inner diameter of the thin-walled workpiece to be ground, and the other end is provided with a threaded section cooperating with a locking nut. The locking nut is arranged on the threaded section of the core shaft, and the threaded section is provided with scale lines corresponding to the opening diameter of the expansion sleeve. A conical ring is provided on the core shaft between the conical stopper and the threaded section; the outer conical surface of the conical ring abuts against the inner conical surface of the expansion sleeve, and the expansion sleeve can be moved axially along the core shaft by rotating the locking nut.

[0010] It should be noted that radial positioning is achieved through the close fit between the conical stopper and the inner diameter of the workpiece, and then the locking nut is rotated to make the expansion sleeve move axially along the core shaft, the inner conical surface of the expansion sleeve abuts against the outer conical surface of the conical ring and gradually opens, exerting uniform radial pressure on the inner wall of the workpiece to achieve axial positioning, and utilizing the conical stopper and the expansion sleeve for dual positioning to achieve precise matching of the inner diameter of the workpiece and provide stable axial clamping force to ensure the stability of the workpiece during the grinding process; and setting scale lines on the threaded section to correspond one-to-one to the opening diameter of the expansion sleeve makes it easy for the operator to intuitively and accurately adjust the position of the expansion sleeve, accurately control the degree of tightening, improve the clamping accuracy, and effectively prevent the expansion sleeve from opening too much and damaging the workpiece.

[0011] Preferably, a cutting plane is provided on the circumferential surface of the threaded section of the mandrel along the axial direction of the mandrel, and a scale bar is provided on the cutting plane.

[0012] It should be noted that the setting of the cutting plane provides a flat carrier for the scale bar, ensuring the clarity and accuracy of the scale line. The operator can judge the moving distance of the expansion sleeve by observing the scale bar, and then accurately control the opening degree of the expansion sleeve, which improves the ease of use and precision control capability of the positioning tooling, and helps to improve the efficiency and quality of the grinding process.

[0013] Preferably, a positioning block is provided at one end of the core shaft away from the threaded section, the conical stopper is detachably mounted on the core shaft between the positioning block and the threaded section, the conical ring is arranged on the core shaft between the conical stopper and the threaded section through a limiting device, and the distance between the conical stopper and the conical ring can be controlled by the limiting device.

[0014] It should be noted that the positioning block provides the basis for the installation of the conical stopper. The detachable design of the conical stopper facilitates the replacement of stops of different sizes to accommodate workpieces with different inner diameters. The limit device is arranged between the conical stopper and the conical ring. By adjusting the limit device to control the distance between the two, the position of the conical stopper can be precisely adjusted, so that the positioning tooling can be suitable for clamping workpieces of different lengths.

[0015] Preferably, the limiting device includes a limiting ring and a limiting nut, the limiting ring is coaxially arranged at one end of the conical ring close to the conical stop block, and a threaded hole is opened on the limiting ring, the limiting nut is arranged in the threaded hole, and the limiting nut is rotated to make the limiting nut abut against the core shaft.

[0016] It should be noted that the conical ring can be moved and fixed on the core shaft by rotating the limit nut to loosen or tighten it.

[0017] Preferably, the limiting device is a limiting cylinder, the limiting cylinder is sleeved on the core shaft, and two ends thereof are respectively in contact with a conical stopper and a conical ring.

[0018] It should be noted that by setting a limit cylinder to control the distance between the conical stopper and the conical ring, and by providing limit cylinders of different lengths to correspond to the clamping of workpieces of different lengths, not only the tooling structure is simplified and the clamping efficiency is improved, but also the positioning accuracy is ensured.

[0019] Preferably, the expansion sleeve comprises an elastic ring and a collar, the collar is sleeved on the outside of the conical ring, the collar is surrounded by a plurality of tensioning petals arranged around the circumference, and an annular groove is provided on the circumferential surface of the collar, and the elastic ring is arranged in the annular groove.

[0020] It should be noted that the elastic ring provides a closing elastic force for the sleeve ring, so that its inner wall can fit tightly with the outer wall of the conical ring.

[0021] Preferably, the collar is enclosed by three tensioning petals, cutting planes are provided on both sides of the tensioning petals, and adjacent cuts of the tensioning petals are located on the same plane.

[0022] It should be noted that the tensioning petal structure design makes the force distribution of the expansion sleeve uniform, improves the stability of clamping the workpiece, reduces the risk of deformation of the workpiece during the grinding process, and is conducive to improving grinding accuracy and workpiece quality.

[0023] Preferably, an inner circumferential surface of one end of the collar away from the conical ring is provided with an embedding groove, and the collar is embedded with the end of the locking nut through the embedding groove.

[0024] It should be noted that the snap-in connection between the snap-in groove and the end of the locking nut enhances the operational linkage between the expansion sleeve and the locking nut, improves the overall working stability of the positioning tooling, and ensures smooth and precise control of the tightening process.

[0025] Beneficial effects of the utility model:

[0026] The utility model provides a positioning tool for grinding thin-walled workpieces, which realizes radial positioning through the close cooperation between the conical stopper and the inner diameter of the workpiece, the inner conical surface of the expansion sleeve abuts against and gradually opens the outer conical surface of the conical ring, and exerts uniform radial pressure on the inner wall of the workpiece to realize axial positioning. This design not only ensures the precise matching of the inner diameter of the workpiece, but also provides a stable axial clamping force, effectively guarantees the stability of the workpiece during the grinding process, and avoids processing errors caused by inaccurate positioning. The cutting plane on the threaded section of the mandrel provides a flat carrier for the scale bar, which ensures the clarity and accuracy of the scale line, so that the operator can accurately judge the moving distance of the expansion sleeve and accurately control The opening degree of the expansion sleeve further improves the ease of use and precision control ability of the positioning tooling. In addition, the positioning block, detachable conical stopper, limit device and other designs enable the tooling to flexibly adapt to workpieces of different inner diameters and lengths, enhancing the versatility and practicality of the tooling. The limit device adopts a rotating limit nut or selects limit cylinders of different lengths to easily and quickly achieve precise adjustment of the position of the conical stopper and the conical ring, ensuring the adaptability and accuracy of workpiece clamping. With its precise and reliable dual positioning and accurate expansion sleeve opening control, it significantly improves the efficiency, accuracy and quality of thin-walled workpiece grinding and reduces the risk of workpiece damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a three-dimensional schematic diagram of a positioning tool for grinding a thin-walled workpiece according to Example 1 of the utility model.

[0028] Figure 2 This is a cross-sectional view of a positioning tool for grinding a thin-walled workpiece according to Example 1 of the utility model.

[0029] Figure 3 This is a schematic diagram of the installation structure of the expansion sleeve and the locking nut in Example 1 of the utility model.

[0030] Figure 4 This is a schematic diagram of the disassembly of the ring of Example 1 of the utility model.

[0031] Figure 5 This is a schematic diagram of the installation structure of the conical ring and the limiting device in Example 1 of the utility model.

[0032] Figure 6 This is a three-dimensional schematic diagram of a positioning tool for grinding a thin-walled workpiece according to Example 2 of the utility model.

[0033] Figure 7 This is a cross-sectional view of a positioning tool for grinding a thin-walled workpiece according to Example 2 of the utility model.

[0034] In the figure: 1, core shaft; 11, threaded section; 12, positioning block; 2, expansion sleeve; 21, elastic ring; 22, collar; 221, tensioning petal; 222, ring groove; 223, embedding groove; 3, locking nut; 4, conical stopper; 5, conical ring; 6, scale bar; 7, limiting device; 71, limiting ring; 72, limiting nut; 73, limiting cylinder.

[0035] It should be noted that these drawings and text descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Example 1

[0038] like Figure 1-Figure 5 As shown, a positioning tool for grinding a thin-walled workpiece includes: a mandrel 1, an expansion sleeve 2, and a locking nut 3;

[0039] A conical stopper 4 matching the inner diameter of the thin-walled workpiece to be ground is provided at one end of the core shaft 1, and a threaded section 11 cooperating with the locking nut 3 is provided at the other end. The locking nut 3 is arranged on the threaded section 11 of the core shaft 1, and the threaded section 11 is provided with scale lines corresponding to the opening diameter of the expansion sleeve 2. A conical ring 5 is provided on the core shaft 1 between the conical stopper 4 and the threaded section 11; the outer conical surface of the conical ring 5 abuts against the inner conical surface of the expansion sleeve 2, and the expansion sleeve 2 can be moved axially along the core shaft 1 by rotating the locking nut 3.

[0040] A cutting plane is provided on the circumferential surface of the threaded section 11 of the mandrel 1 along the axial direction of the mandrel 1 , and a scale bar 6 is provided on the cutting plane.

[0041] A positioning block 12 is provided at one end of the core shaft 1 away from the threaded section 11, and the conical stopper 4 is detachably mounted on the core shaft 1 between the positioning block 12 and the threaded section 11. The conical ring 5 is arranged on the core shaft 1 between the conical stopper 4 and the threaded section 11 through a limiting device 7, and the distance between the conical stopper 4 and the conical ring 5 can be controlled by the limiting device 7.

[0042] The limiting device 7 includes a limiting ring 71 and a limiting nut 72. The limiting ring 71 is coaxially arranged at one end of the conical ring 5 close to the conical stopper 4, and a threaded hole is opened on the limiting ring 71. The limiting nut 72 is arranged in the threaded hole, and the limiting nut 72 is rotated to make it abut against the core shaft 1.

[0043] The expansion sleeve 2 includes an elastic ring 21 and a collar 22. The collar 22 is sleeved on the outside of the conical ring 5. The collar 22 is surrounded by multiple tensioning petals 221 arranged around the circumference, and an annular groove 222 is opened on the circumferential surface of the collar 22. The elastic ring 21 is arranged in the annular groove 222.

[0044] The collar 22 is formed by enclosing three tensioning petals 221 . Cutting planes are provided on both sides of the tensioning petals 221 , and adjacent cuts of the tensioning petals 221 are located on the same plane.

[0045] An inner circumferential surface of one end of the collar 22 away from the conical ring 5 is provided with an embedding groove 223 , and the collar 22 is embedded with the end of the locking nut 3 via the embedding groove 223 .

[0046] The working principle and use method of a positioning tool for grinding thin-walled workpieces in this embodiment:

[0047] The present embodiment provides a positioning tool for grinding thin-walled workpieces, which realizes radial positioning by the close fit between the conical stopper 4 and the inner diameter of the workpiece, ensuring that the inner diameter of the workpiece and the conical stopper 4 are precisely matched in size, providing a stable reference for subsequent grinding, and the inner conical surface of the expansion sleeve 2 abuts against and gradually opens the outer conical surface of the conical ring 5, applying uniform radial pressure to the inner wall of the workpiece to realize axial positioning and clamping; the operator intuitively and accurately adjusts the position of the locking nut 3 according to the scale lines on the threaded segment 11, controls the opening diameter of the expansion sleeve 2, and thereby accurately controls the clamping force on the workpiece to avoid damaging the workpiece due to over-tightening or loosening the workpiece due to over-loosening.

[0048] When in use, according to the inner diameter and length of the thin-walled workpiece to be ground, select a suitable conical stopper 4 and install it on the core shaft 1, adjust the distance between the conical stopper 4 and the conical ring 5 through the limiting device 7 (limiting ring 71 and limiting nut 72) to adapt to the length of the workpiece, put the thin-walled workpiece to be ground on the adjusted conical stopper 4, so that its inner diameter is closely matched with the conical stopper 4 to achieve radial positioning, put the expansion sleeve 2 on the outside of the conical ring 5 to ensure that the inner conical surface of the expansion sleeve 2 is closely fitted with the outer conical surface of the conical ring 5, observe the scale line on the cutting plane of the threaded segment 11, rotate the locking nut 3 to make the expansion sleeve 2 move axially along the core shaft 1, and adjust the diameter of the workpiece according to the workpiece. According to factors such as material and thickness, the opening diameter of the expansion sleeve 2 is gradually adjusted according to the scale line indication until the appropriate clamping force is reached. At this time, the tensioning petal 221 of the expansion sleeve 2 is evenly pressed against the inner wall of the workpiece under the action of the elastic ring 21 to achieve axial positioning and clamping. After completing the above clamping, the positioning tooling together with the clamped workpiece is installed on the grinding machine for grinding. During the entire grinding process, the workpiece maintains stable radial and axial positioning to ensure machining accuracy. After grinding is completed, the locking nut 3 is rotated in the opposite direction to release the clamping force of the expansion sleeve 2 on the workpiece, the workpiece is removed, and then the components of the positioning tooling are cleaned to remove grinding residues to prepare for the next use.

[0049] Example 2

[0050] like Figure 6 and Figure 7 As shown, a positioning tool for grinding a thin-walled workpiece in this embodiment includes: a mandrel 1, an expansion sleeve 2, and a locking nut 3;

[0051] A conical stopper 4 matching the inner diameter of the thin-walled workpiece to be ground is provided at one end of the core shaft 1, and a threaded section 11 cooperating with the locking nut 3 is provided at the other end. The locking nut 3 is arranged on the threaded section 11 of the core shaft 1, and the threaded section 11 is provided with scale lines corresponding to the opening diameter of the expansion sleeve 2. A conical ring 5 is provided on the core shaft 1 between the conical stopper 4 and the threaded section 11; the outer conical surface of the conical ring 5 abuts against the inner conical surface of the expansion sleeve 2, and the expansion sleeve 2 can be moved axially along the core shaft 1 by rotating the locking nut 3.

[0052] A cutting plane is provided on the circumferential surface of the threaded section 11 of the mandrel 1 along the axial direction of the mandrel 1 , and a scale bar 6 is provided on the cutting plane.

[0053] A positioning block 12 is provided at one end of the core shaft 1 away from the threaded section 11, and the conical stopper 4 is detachably mounted on the core shaft 1 between the positioning block 12 and the threaded section 11. The conical ring 5 is arranged on the core shaft 1 between the conical stopper 4 and the threaded section 11 through a limiting device 7, and the distance between the conical stopper 4 and the conical ring 5 can be controlled by the limiting device 7.

[0054] The limiting device 7 is a limiting cylinder 73 , which is sleeved on the core shaft 1 , and has two ends that abut against the conical stopper 4 and the conical ring 5 , respectively.

[0055] The expansion sleeve 2 includes an elastic ring 21 and a collar 22. The collar 22 is sleeved on the outside of the conical ring 5. The collar 22 is surrounded by multiple tensioning petals 221 arranged around the circumference, and an annular groove 222 is opened on the circumferential surface of the collar 22. The elastic ring 21 is arranged in the annular groove 222.

[0056] The collar 22 is formed by enclosing three tensioning petals 221 . Cutting planes are provided on both sides of the tensioning petals 221 , and adjacent cuts of the tensioning petals 221 are located on the same plane.

[0057] An inner circumferential surface of one end of the collar 22 away from the conical ring 5 is provided with an embedding groove 223 , and the collar 22 is embedded with the end of the locking nut 3 via the embedding groove 223 .

[0058] Compared with Example 1:

[0059] The present embodiment provides a positioning tool for grinding thin-walled workpieces. By adopting a limiting cylinder 73 to replace the original limiting ring 71 and limiting nut 72, a limiting cylinder 73 of corresponding length can be directly selected during clamping to ensure the precise distance between the conical stopper 4 and the conical ring 5, thereby avoiding operational errors that may be introduced by rotating the limiting nut 72 multiple times, enhancing the accuracy of the positioning tool in clamping workpieces of different lengths, significantly improving the distance adjustment speed when clamping the workpiece, improving work efficiency, achieving structural simplification, improved clamping efficiency and enhanced positioning accuracy, and further improving the practicality and scope of application of the positioning tool.

[0060] Finally, it should be noted that the above is only a preferred embodiment of the utility model, which is only used to illustrate the technical solution of the utility model, and is not used to limit the protection scope of the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model are included in the protection scope of the utility model.

[0061] In the description of the present invention, it needs to be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "upper end", "lower end", "upper surface", "lower surface", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connection" and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

Claims

1. A positioning tool for grinding a thin-walled workpiece, comprising: Mandrel (1), expansion sleeve (2), locking nut (3); characterized in that: One end of the mandrel (1) is provided with a conical stopper (4) matching the inner diameter of the thin-walled workpiece to be ground, and the other end is provided with a threaded section (11) matched with a locking nut (3); the locking nut (3) is arranged on the threaded section (11) of the mandrel (1); the threaded section (11) is provided with a scale line corresponding to the opening diameter of the expansion sleeve (2); a conical ring (5) is provided on the mandrel (1) between the conical stopper (4) and the threaded section (11); the outer conical surface of the conical ring (5) abuts against the inner conical surface of the expansion sleeve (2), and the expansion sleeve (2) can be moved axially along the mandrel (1) by rotating the locking nut (3).

2. A positioning fixture for grinding thin-walled workpieces as claimed in claim 1, characterized in that: A cutting plane is provided on the circumferential surface of the threaded section (11) of the mandrel (1) along the axial direction of the mandrel (1), and a scale bar (6) is provided on the cutting plane.

3. A positioning fixture for grinding thin-walled workpieces as claimed in claim 1, characterized in that: A positioning block (12) is provided at one end of the core shaft (1) away from the threaded section (11); the conical stopper (4) is detachably sleeved on the core shaft (1) between the positioning block (12) and the threaded section (11); the conical ring (5) is arranged on the core shaft (1) between the conical stopper (4) and the threaded section (11) via a limiting device (7); and the distance between the conical stopper (4) and the conical ring (5) can be controlled via the limiting device (7).

4. A positioning fixture for grinding thin-walled workpieces as claimed in claim 3, characterized in that: The limiting device (7) comprises a limiting ring (71) and a limiting nut (72); the limiting ring (71) is coaxially arranged at one end of the conical ring (5) close to the conical stopper (4); a threaded hole is provided on the limiting ring (71); the limiting nut (72) is arranged in the threaded hole; and the limiting nut (72) is rotated to make the limiting nut (72) contact the core shaft (1).

5. A positioning fixture for grinding thin-walled workpieces as claimed in claim 3, characterized in that: The limiting device (7) is a limiting cylinder (73), which is sleeved on the core shaft (1) and has two ends respectively abutting against a conical stopper (4) and a conical ring (5).

6. A positioning fixture for grinding thin-walled workpieces as claimed in claim 1, characterized in that: The expansion sleeve (2) comprises an elastic ring (21) and a collar (22). The collar (22) is sleeved on the outside of the conical ring (5). The collar (22) is enclosed by a plurality of tensioning petals (221) arranged around the circumference. An annular groove (222) is provided on the circumferential surface of the collar (22), and the elastic ring (21) is arranged in the annular groove (222).

7. A positioning fixture for grinding a thin-walled workpiece as claimed in claim 6, characterized in that: The collar (22) is formed by enclosing three tensioning petals (221), and cutting planes are provided on both sides of the tensioning petals (221), and adjacent cuts of the tensioning petals (221) are located on the same plane.

8. A positioning fixture for grinding a thin-walled workpiece as claimed in claim 6, characterized in that: An inner circumferential surface of one end of the collar (22) away from the conical ring (5) is provided with a snap-fitting groove (223), and the collar (22) is snap-fittedly connected to the end of the locking nut (3) via the snap-fitting groove (223).

Images