Precise centering clamp for annular thin-wall part

Abstract

The invention belongs to the field of machining, and particularly relates to a precise centering clamp for an annular thin-wall part. A precise centering clamp for an annular thin-wall part is reasonable in structure, has the self-adaptive adjusting capacity and can achieve precise centering. The precise centering clamp comprises a clamp base and the like. A bottom supporting piece is arranged at the top of the clamp base and can support and place workpieces with different diameters, a circle of rails are arranged on the top of the clamp base in the radial direction of the clamp base, adapters are arranged on the rails in a sliding mode and are in an L shape, clamping jaw bodies are connected to the inner side faces of the adapters, and the clamping jaw bodies can be detached. According to the clamping jaw, the clamping jaw body is divided into two parts through the arc-shaped groove, the clamping jaw body has an open space, so that the two faces of the clamping jaw body can make contact with the outer side wall of the annular thin-wall part, the stress points of the clamping jaw body and the annular thin-wall part are increased, the annular thin-wall part is better fixed, and the clamping jaw body can be prevented from being damaged due to stress.

Description

Technical Field

[0001] This invention belongs to the field of machining, and in particular relates to a precision centering fixture for annular thin-walled parts. Background Technology

[0002] In the field of machining, annular thin-walled parts are widely used in aerospace, precision instruments, and automobile manufacturing industries. The machining accuracy of their inner walls directly affects the overall performance of the parts. To ensure machining quality, annular thin-walled parts typically require high-precision centering and clamping to ensure they maintain a stable position and orientation during machining.

[0003] Currently, multi-jaw linkage fixtures (such as three-jaw chucks or dedicated multi-point centering fixtures) are mostly used for centering and clamping of annular thin-walled parts. Multiple fixtures move radially towards the center of the workpiece simultaneously, applying centripetal force from the outer wall to achieve clamping. However, this type of clamping method has significant technical drawbacks in practical applications.

[0004] Due to manufacturing precision issues, installation errors, and wear from long-term use, the working surfaces of each fixture cannot achieve complete contact with the outer surface of the annular thin-walled part, resulting in uneven distribution of stress points during clamping. This localized stress concentration not only easily causes localized damage to the fixture and shortens its service life, but more seriously, it can cause elastic or plastic deformation of the thin-walled workpiece during clamping, damaging its original geometric accuracy and affecting the shape, positional accuracy, and dimensional consistency of subsequent machining.

[0005] Therefore, there is an urgent need to develop a precision centering fixture for annular thin-walled parts that has a reasonable structure, adaptive adjustment capabilities, and can achieve precise centering. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention provides a ring-shaped thin-walled part precision centering fixture with reasonable structure, adaptive adjustment capability, and the ability to achieve precise centering.

[0007] The technical solution is as follows: A precision centering fixture for annular thin-walled parts includes a fixture base, a bottom support, a track, an adapter, a jaw body, and an adaptive clamping structure. The bottom support is provided on the top of the fixture base, which can support and place workpieces of different diameters. A track is provided on the top of the fixture base along its radial direction, and an adapter is slidably mounted on the track. The adapter is L-shaped, and the jaw body is connected to the inner side of the adapter. The jaw body is detachable, and the inner side of the jaw body has an adaptive clamping structure to ensure that the jaw body can better clamp the workpiece.

[0008] Furthermore, the bottom support includes a positioning plate and a support column. A ring of positioning plates is arranged radially on the top of the fixture seat. The positioning plates are installed offset from the track. A row of positioning holes is opened on each positioning plate. A support column is inserted into the positioning hole of each positioning plate. Each support column is equidistant from the axis of the fixture seat.

[0009] Furthermore, an arc-shaped adaptation groove is provided on the circumferential contact surface between the adapter and the gripper body.

[0010] Furthermore, the adaptive clamping structure consists of an arc-shaped groove vertically formed on the inner side of the gripper body, and fixing teeth provided on the inner side of the gripper body.

[0011] Furthermore, it also includes a centering block and a support block. A centering block is provided on the lower part of the inner side of the adapter, and a support block with a height lower than the centering block is provided on the inner side of the centering block. The upper surface of the support block and the inner side of the centering block form a stepped surface.

[0012] Furthermore, it also includes a centering ring, which is placed on top of the support block.

[0013] Furthermore, the Rockwell hardness of the centering ring is greater than that of the centering block.

[0014] The beneficial effects are as follows: This invention divides the gripper body into two parts through an arc-shaped groove, providing an opening space for both surfaces of the gripper body to contact the outer wall of the annular thin-walled component. This increases the number of stress points between the gripper body and the annular thin-walled component, resulting in better fixation of the component and preventing damage to the gripper body due to stress. Furthermore, the fixing teeth on the inner side of the gripper body change the traditional surface or line contact mode to a point-fixing mode. This point contact significantly increases the actual contact area between the fixture and the workpiece, avoiding stress concentration caused by surface mismatch during large-area clamping. This effectively reduces the elastic or plastic deformation of the workpiece during clamping, maintains its original geometry, and improves machining accuracy. At the same time, the evenly distributed point contacts increase the working friction coefficient between the fixture and the outer wall of the part, allowing the workpiece to obtain the same amount of friction while using a smaller radial force, further reducing the elastic deformation of the part. Before machining the workpiece, the centering ring is placed on top of the support block, and then the jaw bodies are closed inward, so that the centering block contacts the outer surface of the centering ring. Before clamping the workpiece, it is ensured that the distance between each jaw body and the axis of the workpiece is equal. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention when clamping a workpiece.

[0016] Figure 2 This is a schematic diagram of the three-dimensional structure after the workpiece is removed according to the present invention.

[0017] Figure 3This is a three-dimensional structural diagram of the bottom support member of the present invention.

[0018] Figure 4 This is a three-dimensional structural diagram of the centering ring of the present invention during operation.

[0019] Figure 5 This is a three-dimensional structural diagram of the support block and centering ring of the present invention.

[0020] Reference numerals: 1_clamp base, 2_positioning plate, 3_positioning hole, 4_support column, 5_track, 6_adapter base, 6a_adaptation groove, 7_gripper body, 8_arc groove, 9_fixed tooth, 10_centering block, 11_support block, 12_centering ring. Detailed Implementation

[0021] The accompanying drawings in this disclosure are not drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this disclosure are only structural schematic diagrams.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] Example: A precision centering fixture for annular thin-walled parts, such as Figures 1-4As shown, the fixture includes a fixture base 1, a bottom support, a track 5, an adapter 6, a gripper body 7, and an adaptive clamping structure. The fixture base 1 has a bottom support on its top, which can support and place workpieces of different diameters to accommodate the processing of workpieces of different sizes. The bottom support includes a positioning plate 2 and support columns 4. A ring of positioning plates 2 is fixed radially to the top of the fixture base 1 by bolts. Each positioning plate 2 has a row of positioning holes 3, and a support column 4 is inserted into each positioning hole 3. The bottom of the workpiece is supported by the support columns 4. Each support column 4 is equidistant from the axis of the fixture base 1, ensuring that the bottom of the workpiece contacts the top of all the support columns 4. A track 5 is fixed radially to the top of the fixture base 1 by bolts. Installed offset from track 5, each track 5 has a sliding adapter 6. The adapter 6 is L-shaped, and the inner side of the adapter 6 is connected to the gripper body 7. The gripper body 7 is detachable. The circumferential contact surface between the adapter 6 and the gripper body 7 is provided with an arc-shaped adaptation groove 6a. When the gripper body 7 is fixed to the inner side of the adapter 6, the adaptation groove 6a allows the contact surface between the adapter 6 and the gripper body 7 to fit better. The inner side of the gripper body 7 has an adaptive clamping structure to ensure that the gripper body 7 can clamp the workpiece better. The adaptive clamping structure consists of an arc-shaped groove 8 vertically opened on the inner side of the gripper body 7 and a fixing tooth 9 provided on the inner side of the gripper body 7. The arc-shaped groove 8 divides the fixing tooth 9 on the inner side of each gripper body 7 into two sides, thereby increasing the contact points between the gripper body 7 and the workpiece.

[0024] A precision centering fixture for annular thin-walled parts, compared with existing technologies, first places the annular thin-walled part on top of a support column 4 when centering and clamping it. The support column 4 is inserted into different positioning holes 3 to support workpieces of different sizes. Then, the adapter seat 6 is controlled to move inward synchronously, causing the gripper body 7 to move inward synchronously until the gripper body 7 fixes the annular thin-walled part. After that, the gripper body 7 stops working, and the annular thin-walled part is then processed. When centering and clamping the annular thin-walled part, because the arc groove 8 divides the gripper body 7 into two parts, the gripper body 7 has an opening space when it contacts the annular thin-walled part. This allows both surfaces of the gripper body 7 to contact the outer wall of the annular thin-walled part, increasing the force points between the gripper body 7 and the annular thin-walled part, which can better fix the annular thin-walled part and also prevent the gripper body 7 from... Because of the stress damage, the service life of the gripper body 7 is improved. In addition, the fixing teeth 9 on the inner side of the gripper body 7 change the traditional surface contact or line contact mode to a point fixing mode. The point contact significantly increases the actual contact area between the fixture and the workpiece (when there is a large arc surface contact, due to the existence of shape and size errors, the actual contact surface is only in the layout, and the total contact area is smaller. After changing to the evenly distributed "point contact", there is a larger total contact area). This avoids the stress concentration problem caused by surface mismatch when clamping a large area. For thin-walled parts, this can effectively reduce the elastic or plastic deformation of the workpiece during the clamping process, maintain its original geometry, and improve the machining accuracy. At the same time, the evenly distributed point contact increases the working friction coefficient between the fixture and the outer wall of the part, so that while obtaining the same amount of friction force, a smaller radial force can be used, further reducing the elastic deformation of the part.

[0025] like Figure 5 As shown, to improve the accuracy of workpiece centering, a centering block 10, a support block 11, and a centering ring 12 are also included. The centering block 10 is located on the lower part of the inner side of the adapter 6. The inner side of the centering block 10 is a vertical plane. A support block 11, lower than the height of the centering block 10, is located on the inner side of the centering block 10. The upper surface of the support block 11 forms a stepped surface with the inner side of the centering block 10. The centering ring 12 is placed on top of the support block 11. Before workpiece processing, the centering ring 12 is placed on top of the support block 11, and then the gripper body 7 is... The centering blocks 10 and 10 are brought together inwards, so that the outer surface of the centering ring 12 contacts the centering block 10. This is to ensure that the distance between each gripper body 7 and the axis of the workpiece is equal before clamping the workpiece, thereby improving the subsequent clamping accuracy. The Rockwell hardness of the centering ring 12 is greater than that of the centering block 10. The centering ring 12 is made of 40Cr and has a hardness of HRC55-60 after heat treatment. The centering block 10 is made of Q235 material and has a hardness of HRC15-20. This can prevent the centering ring 12 from being damaged by the centering block 10.

[0026] Although this disclosure has been described with respect to only a limited number of embodiments, those skilled in the art who benefit from this disclosure will understand that various other embodiments can be devised without departing from the scope of the invention. Therefore, the scope of the invention should be limited only by the appended claims.

Claims

1. A precision centering fixture for ring-shaped thin-walled parts, characterized in that, The utility model relates to a self -adaptation clamping structure of fixture, including clamp seat (1), bottom support, track (5), adapter seat (6), clamping jaw body (7) and adaptive clamping structure, clamp seat (1) top is provided with bottom support, and bottom support can support and place workpieces of different diameters, and a circle of track (5) is set up in the radial direction of clamp seat (1) top, and the adapter seat (6) is slidably arranged on the track (5), and the adapter seat (6) is L-shaped, and the inner side of adapter seat (6) is connected with clamping jaw body (7), and clamping jaw body (7) can be detached, and the inner side of clamping jaw body (7) has adaptive clamping structure to ensure that clamping jaw body (7) can better clamp workpieces.

2. The precision centering fixture for a ring-shaped thin-walled part according to claim 1, characterized in that The bottom support includes positioning plates (2) and support columns (4), and a circle of positioning plates (2) is arranged in the radial direction of the top of the clamp seat (1), the positioning plates (2) are installed staggered with the tracks (5), a row of positioning holes (3) are formed in each positioning plate (2), one support column (4) is inserted into each positioning hole (3) on each positioning plate (2), and each support column (4) is the same distance from the axis of the clamp seat (1).

3. The precision centering fixture for ring-shaped thin-walled parts according to claim 1, characterized in that The circumferential contact surface of the adapter seat (6) and the clamping jaw body (7) is provided with an arc-shaped adaptive groove (6a).

4. The precision centering fixture for ring-shaped thin-walled parts according to claim 1, characterized in that The adaptive clamping structure is an arc-shaped groove (8) vertically formed in the inner side of the clamping jaw body (7) and a fixing tooth (9) arranged on the inner side of the clamping jaw body (7).

5. The precision centering fixture for ring-shaped thin-walled parts according to claim 1, characterized in that The utility model also includes a centering block (10) and a support block (11), the inner side of the adapter seat (6) is provided with the centering block (10) at the lower part, the inner side of the centering block (10) is provided with the support block (11) which is lower than the centering block (10) in height, and the upper surface of the support block (11) and the inner side of the centering block (10) form a stepped surface.

6. The precision centering fixture for ring-shaped thin-walled parts according to claim 5, characterized in that The utility model also includes a centering ring (12), which is placed on the top of the support block (11).

7. The precision centering fixture for ring-shaped thin-walled parts according to claim 6, characterized in that The Rockwell hardness of the centering ring (12) is greater than the Rockwell hardness of the centering block (10).

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