A variable-diameter inner half-tube curved surface multi-point positioning clamping numerical control milling clamp

Abstract

The utility model discloses a kind of variable-diameter inner half pipe curved surface multi-point positioning clamping numerical control milling clamps, processing clamp includes: the small end positioning plate and large end positioning plate of obliquely arranged, the plane of small end positioning plate and large end positioning plate is perpendicular to each other;Two sides of small end positioning plate are provided with the small end adjustable clamp plate movable along its oblique direction, and the two sides of large end positioning plate are provided with the large end adjustable clamp plate movable along its oblique direction, and the center of large end positioning plate is provided with fixed clamp plate near the edge of small end positioning plate;Among them, the small end of the small end positioning plate is used to place inner half pipe blank;The large end of the large end positioning plate is used to place inner half pipe blank;Small end adjustable clamp plate is used to clamp the small end of inner half pipe blank, and large end adjustable clamp plate is used to clamp the large end of inner half pipe blank, and fixed clamp plate is used to clamp the top inner wall of the large end of inner half pipe blank. It solves the problem that the existing technology in inner half pipe processing clamp is difficult to adapt to different states of blank, and the clamping process is time-consuming and laborious.

Description

[Technical Field]

[0001] This utility model belongs to the field of aerospace mechanical processing technology, specifically relating to a multi-point positioning and clamping CNC milling fixture for curved surfaces of variable-diameter inner half-pipes. [Background Technology]

[0002] The gas-fired inner tube is a crucial structural component in aerospace liquid rocket engines. Operating in harsh environments, it is made of high-temperature alloy materials. The blank is forged from a 17mm thick sheet metal, resulting in low precision and poor consistency. It lacks accurate features for positioning, and the thinnest part after machining is only 6mm. Furthermore, the heat treatment states of different batches of sheet metal vary significantly, leading to uneven residual stress within the blank and resulting in substantial differences between the blank and the model. This places high demands on subsequent surface machining of the part. Relying solely on three contouring clamps for positioning and clamping cannot meet the requirements for precise and efficient machining. During machining, fixtures are needed to ensure the inner tube is in the correct position and clamped, preventing positional changes and workpiece deformation caused by clamping loosening due to cutting forces and vibrations. Existing fixtures for inner tube machining are generally ill-suited to different blank conditions, and the clamping process is time-consuming and labor-intensive, failing to meet actual machining needs and impacting the efficiency and quality of tube bending. Because the inner tube blank weighs about 20kg, is small in size and has a large wall thickness, the loading, unloading and scribing processes of conventional CNC milling are complicated. In addition, the edges of the large and small ends are rough after cutting, which makes clamping difficult. This also increases the labor intensity and safety risks of workers, as well as the out-of-tolerance rate and non-conforming rate of parts. [Utility Model Content]

[0003] The purpose of this invention is to provide a multi-point positioning and clamping CNC milling fixture for curved surfaces of variable-diameter inner half-tubes, in order to solve the problems in the existing technology of inner half-tube machining fixtures that are difficult to adapt to blanks in different states, cannot guarantee positioning accuracy, and have high cutting resistance of blanks after clamping.

[0004] The present invention adopts the following technical solution: a variable diameter inner half-tube curved surface multi-point positioning and clamping CNC milling fixture, based on an inner half-tube blank, the two ends of the inner half-tube blank are divided into a large end and a small end according to the size of the opening;

[0005] The machining fixture includes: a small end positioning plate and a large end positioning plate that are set at an inclination. The extension lines of the two plates intersect to form an inverted V shape. Both the small end positioning plate and the large end positioning plate are polygonal plate structures. The shape of the polygonal structure matches the inner wall shape of the large end or small end of the corresponding inner half tube blank. The surfaces of the small end positioning plate and the large end positioning plate are perpendicular to each other.

[0006] The top surface of the small end positioning plate is provided with adjustable small end clamps on both sides, which can move along its tilt direction. The top surface of the large end positioning plate is provided with adjustable large end clamps on both sides, which can move along its tilt direction. A fixed clamp is provided at the center of the top surface of the large end positioning plate near the edge of the small end positioning plate.

[0007] The small-end positioning plate is used to place the small end of the inner half-tube blank, and the small-end positioning plate is parallel to the surface where the small end of the inner half-tube blank is located; the large-end positioning plate is used to place the large end of the inner half-tube blank, and the large-end positioning plate is parallel to the surface where the large end of the inner half-tube blank is located; the small-end adjustable clamping plate is used to clamp the inner walls on both sides of the small end of the inner half-tube blank, the large-end adjustable clamping plate is used to clamp the inner walls on both sides of the large end of the inner half-tube blank, and the fixed clamping plate is used to clamp the top inner wall of the large end of the inner half-tube blank.

[0008] Furthermore, each small-end adjustable clamping plate includes: a small-end adjustable support block, which is bolted to an oblong hole on the small-end positioning plate, the oblong hole extending in the same direction as the small-end positioning plate; and a small-end adjustable support block pressure plate, which is detachably connected to the small-end adjustable support block by bolts, for clamping the outer wall of the inner half-tube blank; the surfaces on the small-end support plate and the small-end adjustable support block that contact the inner half-tube blank are both contour surfaces of the theoretical model.

[0009] Furthermore, each large-end adjustable clamping plate includes: a large-end adjustable support block, which is bolted to an oblong hole on the large-end positioning plate, the oblong hole extending in the same direction as the large-end positioning plate; and a large-end adjustable support block pressure plate, which is detachably connected to the large-end adjustable support block by bolts, for clamping the outer wall of the inner half-tube blank; the surfaces of the large-end adjustable support block pressure plate and the large-end adjustable support block that contact the inner half-tube blank are both contour surfaces of the theoretical model.

[0010] Furthermore, the fixing clamp includes a large-end fixing support block, which is fixedly connected to the center of the top surface of the large-end positioning plate near the edge of the small-end positioning plate; it also includes a large-end fixing support block pressure plate, which is detachably connected to the large-end fixing support block by bolts, and is used to clamp the outer wall of the inner half-tube blank; the surfaces of the large-end fixing support block pressure plate and the large-end fixing support block that contact the inner half-tube blank are both contour surfaces of the theoretical model.

[0011] Furthermore, a cam connecting column mounting block is provided below the connecting plate, and a cam connecting column is provided through the cam connecting column mounting block; the axial direction of the cam connecting column is perpendicular to the extension direction of the connecting plate, and cams are connected to both ends of the cam connecting column; it is used to rotate with the cam connecting column to achieve contact with the side wall of the inner half tube blank and complete the leveling of the inner half tube blank.

[0012] Furthermore, the bottoms of the small-end positioning plate and the large-end positioning plate are connected to an H-shaped support frame. The H-shaped support frame includes a small-end support plate that is connected to the small-end positioning plate and is vertically arranged, and a large-end support plate that is connected to the large-end positioning plate and is vertically arranged. A connecting plate connects the small-end support plate and the large-end support plate.

[0013] Furthermore, it also includes two springs, each with its two ends connected between the cam and the connecting plate.

[0014] The beneficial effects of this utility model are as follows: In order to greatly improve the processing quality and efficiency of gas pipe bends, eliminate the problems of difficult and easy deviation in CNC machining of high-temperature alloy large curved surface parts caused by poor forging quality of pipe bend blanks, shorten the processing cycle of parts, reduce the processing cost of parts, and reduce the labor intensity of operators, this utility model provides a design method for a processing fixture for inner half-pipes. This fixture design method is adaptive to the structural size characteristics of parts and combined with adjustable support design, which greatly eliminates the deformation after processing of inner half-pipes.

[0015] The positioning method of this invention is to accurately position the inner half-tube blank using a process datum line. Clamping of the large and small ends is achieved through a conformal clamping mechanism that adapts to changes in the blank's dimensions. The rigidity enhancement device of this invention includes a cam connecting column, a cam, and a spring. This device dynamically adjusts the support in the intermediate area to suppress machining vibrations. The auxiliary device of this invention includes a cam connecting column mounting block and a connecting plate. This auxiliary device enables rapid connection between the fixture and the blank, as well as rigidity enhancement.

[0016] When machining medium to large-sized free-form internal gas pipe blanks in the aerospace field, the novel CNC milling machine tooling fixture structure of this utility model is used. The 0° and 90° reference lines in the design drawing are marked on the large and small ends of the inner half-pipe and selected as the process reference lines. The inner half-pipe blank is positioned at multiple points with reference to their positions. That is, multiple clamping blocks are used at both ends and spring-connected cams are used for floating positioning on the sides.

[0017] Advantages of using multi-point positioning:

[0018] Firstly, dimensional errors caused by springback and thermal expansion and contraction during the forging process result in poor forming accuracy of the inner tube blank. The actual blank may deviate from the theoretical model by more than 5mm, and even blanks from the same batch may vary in shape, exhibiting individual dimensional characteristics. This is the main reason why machining is prone to exceeding tolerances. Multi-point positioning is employed, with adjustable clamping blocks at both ends that can be adjusted according to the actual state of the blank. Cams and springs can also support lateral floating, thus ensuring the clamping of blanks in different states.

[0019] Secondly, the distance between the two end faces of the workpiece is large, and the part is prone to deformation during cutting. Using two-end positioning can improve the rigidity of the system and resist stress deformation. In addition, the finished product is a variable wall thickness structure, so the amount of material removed in each processing area is different. The cutting resistance is greater in the area with a large amount of material removed. Using multi-point positioning, the floating of cams and springs can overcome the cutting resistance during processing. Combined with two-end positioning, workpiece chatter is suppressed, displacement is avoided, and product quality is guaranteed.

[0020] The inner tube blank is positioned based on its location. Positioning from both ends has two advantages: first, the long span between the two positioning datums results in high positioning accuracy, meeting the machining accuracy requirements of the part; second, positioning from both ends provides high system rigidity, stable machining process, and allows for the addition of supports in the middle to further enhance system rigidity. This effectively solves the problems of low machining efficiency and out-of-tolerance issues, significantly shortening the machining cycle of medium-sized inner tubes. [Attached Image Description]

[0021] Figure 1 This is a schematic diagram of the structure of a multi-point positioning and clamping CNC milling fixture for a variable-diameter inner half-pipe curved surface according to the present invention;

[0022] Figure 2 This is a three-dimensional structural diagram of a multi-point positioning and clamping CNC milling fixture for a variable-diameter inner half-pipe curved surface according to one perspective.

[0023] Figure 3 This is a three-dimensional structural diagram of a multi-point positioning and clamping CNC milling fixture for a variable-diameter inner half-pipe curved surface according to another perspective.

[0024] Figure 4 This is a schematic diagram showing the installation relationship between a CNC milling fixture for multi-point positioning and clamping of a variable-diameter inner half-pipe curved surface and an inner half-pipe blank according to this utility model.

[0025] Figure 5 This is a schematic diagram of the baseline of the inner half-tube blank of this utility model.

[0026] Among them, 1. small end positioning plate, 2. small end support plate, 3. connecting plate, 4. base plate, 5. small end adjustable support block pressure plate, 6. small end adjustable support block, 7. cam connecting column mounting block, 8. cam connecting column, 9. cam, 10. large end adjustable support block pressure plate, 11. large end adjustable support block, 12. large end support plate, 13. large end positioning plate, 14. large end fixed support block, 15. large end fixed support block pressure plate, 16. spring, 17. inner half tube blank.

Detailed Implementation Methods

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] Gas bends are used as gas pipes in engines. They have different diameters at both ends; the larger diameter end is called the large end, and the smaller diameter end is called the small end. The planes of the large and small ends are perpendicular to each other. The gas bend blank is divided into two parts along its axis, resulting in an inner half-pipe blank and an outer half-pipe blank. After processing, the inner and outer half-pipes are finally welded together to form a complete gas bend.

[0029] For the inner half-tube, its bending radius is R, which is the radius of the circle where the inner and outer half-tubes intersect. This utility model proposes a multi-point positioning and clamping CNC milling fixture for the curved surface of a variable-diameter inner half-tube, based on an inner half-tube blank 17. The tooling of this utility model is dedicated to the pipe, and before designing the tooling, it will be matched and designed according to the various dimensions of the inner half-tube blank 17.

[0030] like Figure 1 As shown, the machining fixture includes: a small end positioning plate 1 and a large end positioning plate 13, which are inclined and intersect to form an inverted V shape. Both the small end positioning plate 1 and the large end positioning plate 13 are polygonal plate structures. The shape of the polygonal structure matches the inner wall shape of the large or small end of the corresponding inner half-tube blank 17, so as to better support and position the large or small end. The surfaces of the small end positioning plate 1 and the large end positioning plate 13 are perpendicular to each other.

[0031] The spacing between the small-end positioning plate 1 and the large-end positioning plate 13 is adjusted according to the bending radius R of the inner half-tube. The spacing should be chosen such that after the small end of the inner half-tube blank is placed on the small-end positioning plate 1, the inclined plane of the small-end positioning plate 1 coincides with the inclined plane of the 0° baseline of the theoretical model, and the inclined plane of the large-end positioning plate 13 coincides with the inclined plane of the 90° baseline of the theoretical model. The 0° baseline and 90° baseline of the theoretical model of the inner half-tube blank are as follows: Figure 5 As shown, the 0° baseline is located 20±1mm from the edge of the small end, and the 90° baseline is located 20±1mm from the edge of the large end.

[0032] The small-end positioning plate 1 has adjustable small-end clamps on both sides of its top surface, which can move along its inclined direction. The large-end positioning plate 13 has adjustable large-end clamps on both sides of its top surface, which can move along its inclined direction. A fixed clamp is provided at the center of the top surface of the large-end positioning plate 13 near the edge of the small-end positioning plate 1. The small-end adjustable clamps are used to clamp the inner walls on both sides of the small end of the inner half-tube blank 17, the large-end adjustable clamps are used to clamp the inner walls on both sides of the large end of the inner half-tube blank 17, and the fixed clamp is used to clamp the top inner wall of the large end of the inner half-tube blank 17.

[0033] In some embodiments, such as Figure 2As shown, each small-end adjustable clamping plate includes: a small-end adjustable support block 6, which is bolted to a slotted hole on the small-end positioning plate 1. The extension direction of the slotted hole is the same as that of the small-end positioning plate 1. By moving within the slotted hole, for example, a stroke adjustment of ±5mm can be achieved; it also includes a small-end adjustable support block pressure plate 5, which is detachably connected to the small-end adjustable support block 6 by bolts, and is used to clamp the outer wall of the inner half-tube blank 17; the clamping force generated between the two is perpendicular to the axis of the inner half-tube blank 17; the surfaces on the small-end support plate 2 and the small-end adjustable support block 6 that contact the inner half-tube blank 17 are both contoured surfaces of the theoretical model. The contoured surface mentioned in this utility model refers to a curved surface used to simulate or approximate the actual surface shape of the corresponding position of the inner half-tube blank.

[0034] In some embodiments, such as Figure 3 As shown, each large-end adjustable clamping plate includes: a large-end adjustable support block 11, which is bolted to a slotted hole on the large-end positioning plate 13, the extension direction of which is the same as that of the large-end positioning plate 13. Movement within the slotted hole allows for stroke adjustment, for example, ±5mm. It also includes a large-end adjustable support block pressure plate 10, which is detachably connected to the large-end adjustable support block 11 via bolts, used to clamp the outer wall of the inner half-tube blank 17; the clamping force generated between the two is perpendicular to the axis of the inner half-tube blank 17; the surfaces of the large-end adjustable support block pressure plate 10 and the large-end adjustable support block 11 that contact the inner half-tube blank 17 are contoured surfaces of the theoretical model.

[0035] In some embodiments, the fixing clamp includes a large-end fixing support block 14, which is fixedly connected to the top center of the large-end positioning plate 13 near the edge of the small-end positioning plate 1; it also includes a large-end fixing support block pressure plate 15, which is detachably connected to the large-end fixing support block 14 by bolts, and is used to clamp the outer wall of the inner half-tube blank 17; the surfaces of the large-end fixing support block pressure plate 15 and the large-end fixing support block 14 that contact the inner half-tube blank 17 are both contour surfaces of the theoretical model.

[0036] In some embodiments, a cam connecting post mounting block 7 is provided below the connecting plate 3, and a cam connecting post 8 is provided through the cam connecting post mounting block 7. The cam connecting post mounting block 7 is provided with a clearance fit hole, allowing the cam connecting post 8 to rotate freely and be axially fixed. The axial direction of the cam connecting post 8 is perpendicular to the extension direction of the connecting plate 3, and cams 9 are connected to both ends of the cam connecting post 8. The cam 9 has an involute profile and is used to rotate with the cam connecting post 8 to achieve contact with the side wall of the inner half-tube blank 17. When adjusted so that both sides are in contact with the cam 9, the leveling of the inner half-tube blank 17 is achieved.

[0037] In some embodiments, the bottoms of the small end positioning plate 1 and the large end positioning plate 13 are connected to an H-shaped support frame. The H-shaped support frame includes a small end support plate 2 connected to the small end positioning plate 1 and vertically arranged, and a large end support plate 12 connected to the large end positioning plate 13 and vertically arranged. A connecting plate 3 is connected between the small end support plate 2 and the large end support plate 12.

[0038] In some embodiments, two springs 16 are also included, each spring 16 having its two ends connected to the cam 9 and the connecting plate 3 by screws. This assists in blank alignment and reduces chatter between the tool and the workpiece during machining.

[0039] In this invention, the dimensions and positions of each component of the variable-diameter inner half-tube curved surface multi-point positioning and clamping CNC milling fixture are designed based on the precise dimensions of the pre-machined inner half-tube. The machining fixture is then fabricated according to these dimensions. This fixture is used to fix the inner half-tube blank to be machined, thereby completing the subsequent precision CNC machining. The method of using this variable-diameter inner half-tube curved surface multi-point positioning and clamping CNC milling fixture specifically includes the following:

[0040] Reference Figure 1 First, the large-end support plate 12 and the small-end support plate 2 are positioned by pins and connected by screws, and installed at both ends of the base plate 4 respectively; a connecting plate 3 is installed between the large-end support plate 12 and the small-end support plate 2, positioned by pins and connected by screws; the cam connecting column mounting block 7 is installed at the front end of the connecting plate 3; the large-end support plate 12, the large-end adjustable support block 11, the large-end adjustable support block pressure plate 12, the large-end fixed support block 14, the large-end fixed support block pressure plate 15 and screws are installed on the large-end positioning plate 13 at the corresponding positions; the small-end support plate 2, the small-end adjustable support block 6, the small-end adjustable support block pressure plate 5 and screws are installed on the small-end positioning plate 1 at the corresponding positions; the cam connecting column mounting block 7 is installed on the connecting plate 3; the cam connecting column 8 is inserted into the round hole on the cam connecting column mounting block 7; cams 9 are installed on both sides of the cam connecting column and leveled to align the cams on both sides; spring 16 is installed to tighten the cams.

[0041] When using, assemble the fixture as before.

[0042] Fix the base plate 4 to the CNC machine tool worktable with bolts. Loosen the screws on the positioning block pressure plates and the set screws on the adjustable positioning blocks. Place the bent pipe blank in the corresponding position on the fixture and fine-tune its position, such as... Figure 4 and Figure 5 As shown, the 0° reference line of the inner half-tube blank is aligned with the upper surface of the small end positioning plate 1, the 90° reference line is aligned with the upper surface of the large end positioning plate 13, and both cams are in contact with the blank bevel to achieve horizontal alignment of the half-tube workpiece.

[0043] Then adjust the positions of the adjustable support blocks on both sides to ensure good contact between each support block and the blank. Push the blank to make the contour surface of the large end fixed support block 11 of its inner wall fit. Adjust the waist-shaped hole fixing screws of the small end adjustable support block 6 and the large end adjustable support block 11. Slide the support block along the small end positioning plate 1 and the large end positioning plate 13 to the contact position of the inner wall of the blank. Rotate the threaded pair of the adjustable support block to finely adjust its extension amount. Tighten the waist-shaped hole screws to ensure that the support block has no displacement. Install the small end adjustable support block pressure plate 5 and the large end adjustable support block pressure plate 10 in sequence and tighten the pressure plate screws.

[0044] The blank is finely adjusted by the involute contour to level the two cams. After machining, the parts can be quickly disassembled by loosening the locking screws of the small-end adjustable support block pressure plate 5, the large-end adjustable support block pressure plate 10, and the large-end fixed support block pressure plate 15.

[0045] This utility model's inner half-tube tooling design meets the requirements of adaptive precision machining, significantly improving the finishing quality of the workpiece. The optimized tooling design simplifies the machining process, reduces operator difficulty, and allows for one-time machining on a five-axis precision CNC machine, reducing machining costs. The tooling design employs dynamic rigidity enhancement and vibration suppression technology, significantly improving the machining accuracy of under-supported sections of thin-walled parts with large curvature, and markedly reducing machining chatter and tool breakage rates. The tooling clamping structure is designed to conform to the curvature of the model, and the symmetrical clamping design ensures uniform pressure distribution, avoiding machining deformation caused by localized stress release. While facilitating loading and unloading, the overall tooling structure design fully meets the rigidity and strength requirements for machining.

Claims

1. A CNC milling fixture for multi-point positioning and clamping of curved surfaces of a variable-diameter inner half-pipe, characterized in that, Based on an inner half-tube blank (17), the two ends of the inner half-tube blank (17) are divided into a large end and a small end according to the size of the opening; The variable-diameter inner half-tube curved surface multi-point positioning clamping CNC milling fixture includes: a small end positioning plate (1) and a large end positioning plate (13) set at an inclination. The extension lines of the two intersect to form an inverted V shape. The small end positioning plate (1) and the large end positioning plate (13) are both polygonal plate structures. The shape of the polygonal plate structure matches the inner wall shape of the large end or small end of the corresponding inner half-tube blank. The surfaces of the small end positioning plate (1) and the large end positioning plate (13) are perpendicular to each other. The small end positioning plate (1) has adjustable small end clamps on both sides of its top surface that can move along its tilt direction. The large end positioning plate (13) has adjustable large end clamps on both sides of its top surface that can move along its tilt direction. The large end positioning plate (13) has a fixed clamp at the center of its top surface near the edge of the small end positioning plate (1). Wherein, the small end positioning plate (1) is used to place the small end of the inner half-tube blank (17), and the small end positioning plate (1) is parallel to the surface where the small end of the inner half-tube blank (17) is located; the large end positioning plate (13) is used to place the large end of the inner half-tube blank (17), and the large end positioning plate (13) is parallel to the surface where the large end of the inner half-tube blank (17) is located; the small end adjustable clamp is used to clamp the inner walls on both sides of the small end of the inner half-tube blank (17), the large end adjustable clamp is used to clamp the inner walls on both sides of the large end of the inner half-tube blank (17), and the fixed clamp is used to clamp the top inner wall of the large end of the inner half-tube blank (17).

2. The CNC milling fixture for multi-point positioning and clamping of curved surfaces of a variable-diameter inner half-pipe as described in claim 1, characterized in that, Each of the small-end adjustable clamps includes: a small-end adjustable support block (6), which is bolted to the waist-shaped hole on the small-end positioning plate (1), the extension direction of the waist-shaped hole being the same as the extension direction of the small-end positioning plate (1); and a small-end adjustable support block pressure plate (5), which is detachably connected to the small-end adjustable support block (6) by bolts, for clamping the outer wall of the inner half-tube blank (17); the surfaces of the small-end adjustable support block pressure plate (5) and the small-end adjustable support block (6) that contact the inner half-tube blank (17) are both contour surfaces of the theoretical model.

3. A multi-point positioning and clamping CNC milling fixture for curved surfaces of a variable-diameter inner half-pipe as described in claim 1 or 2, characterized in that, Each of the large-end adjustable clamps includes: a large-end adjustable support block (11), which is bolted to the large-end positioning plate (13) in a waist-shaped hole, the extension direction of which is the same as that of the large-end positioning plate (13); and a large-end adjustable support block pressure plate (10), which is detachably connected to the large-end adjustable support block (11) by bolts, for clamping the outer wall of the inner half-tube blank (17); the surfaces of the large-end adjustable support block pressure plate (10) and the large-end adjustable support block (11) that contact the inner half-tube blank (17) are both contour surfaces of the theoretical model.

4. The CNC milling fixture for multi-point positioning and clamping of curved surfaces of a variable-diameter inner half-pipe as described in claim 3, characterized in that, The fixed clamping plate includes a large end fixed support block (14), which is fixedly connected to the center of the top surface of the large end positioning plate (13) near the edge of the small end positioning plate (1); it also includes a large end fixed support block pressure plate (15), which is detachably connected to the large end fixed support block (14) by bolts and is used to clamp the outer wall of the inner half tube blank (17); the surfaces of the large end fixed support block pressure plate (15) and the large end fixed support block (14) that are in contact with the inner half tube blank (17) are both contour surfaces of the theoretical model.

5. A multi-point positioning and clamping CNC milling fixture for curved surfaces of a variable-diameter inner half-pipe as described in claim 1 or 2, characterized in that, The bottom of the small end positioning plate (1) and the large end positioning plate (13) are connected to an H-shaped support frame. The H-shaped support frame includes a small end support plate (2) connected to the small end positioning plate (1) and vertically arranged, and a large end support plate (12) connected to the large end positioning plate (13) and vertically arranged. A connecting plate (3) is connected between the small end support plate (2) and the large end support plate (12).

6. The CNC milling fixture for multi-point positioning and clamping of curved surfaces of a variable-diameter inner half-pipe as described in claim 5, characterized in that, A cam connecting column mounting block (7) is provided below the connecting plate (3), and a cam connecting column (8) is provided through the cam connecting column mounting block (7); the axial direction of the cam connecting column (8) is perpendicular to the extension direction of the connecting plate (3), and cams (9) are connected to both ends of the cam connecting column (8); the cam (9) is used to rotate with the cam connecting column (8) to achieve contact with the side wall of the inner half-tube blank (17) and complete the leveling of the inner half-tube blank (17).

7. A multi-point positioning and clamping CNC milling fixture for curved surfaces of a variable-diameter inner half-pipe as described in claim 6, characterized in that, It also includes two springs (16), each of which is connected at both ends between the cam (9) and the connecting plate (3).

Images