C / C Composite Plug Convex Surface Machining Fixture and Machining Method

Abstract

The present invention relates to a C / C composite material plug cone convex surface processing fixture, which includes a bottom plate and a supporting device for preliminarily supporting the plug cone part; a clamping mechanism for fixing the end of the plug cone part is provided at one axial end of the plug cone part, and a pushing device for pushing the plug cone part tightly into the C-shaped clamping opening of the clamping mechanism is provided at the other axial end of the plug cone part; a pressing device for pressing the plug cone part onto the supporting device is installed on the outer convex surface of the plug cone part; it also includes a balance supporting device for ensuring the balance of the supporting force in the circumferential direction of the plug cone part and a supporting rod member for preventing the deformation of the plug cone part, as well as a processing method for the plug cone part using the fixture. By clamping the two axial sides of the plug cone part blank, the present invention completes the rough milling and finish milling of the convex surface, outer side surface and top surface of the plug cone part in one clamping, reduces the positioning error caused by repeated clamping, improves the machining accuracy of the part, and also reduces the workload of workers and the error caused by multiple clamping to the part machining.

Description

Technical Field

[0001] The present invention relates to the field of processing composite material structures, and relates to a special fixture for a thermal protection component, and particularly relates to a special fixture for a thermal protection component capable of processing multiple surfaces, which is applied to the field of machine tool processing. Background Art

[0002] At present, carbon / carbon composite materials have high specific strength, wear resistance, and high temperature resistance, and have excellent mechanical properties and physical properties such as high specific strength, good dimensional stability, and small thermal expansion coefficient. Therefore, they have been widely used in many fields such as aviation, aerospace, advanced weapon systems, automobiles, electronics, environmental engineering, mechanical manufacturing, instrumentation, and nuclear industry.

[0003] Due to its high strength, hardness, high temperature resistance, corrosion resistance, light weight and other unique properties, C / C composite material has become a new type of material in the field of new materials. However, the blank of the C / C composite material circular arc-shaped bending structural part applied in the aviation field is a special-shaped structural part, and it is difficult to clamp and position. There are still many problems in the processing of its convex curved surface: since the circular arc-shaped bending structural part belongs to a thin-walled structure and the C / C composite material belongs to a difficult-to-machine material, it is difficult to position the part during processing, and it may also undergo processing deformation when subjected to cutting force during processing. The processing time is long and the processing accuracy is difficult to guarantee. Summary of the Invention

[0004] The purpose of the present invention is to avoid the deficiencies of the prior art and provide a fixture for automatically clamping and controlling processing deformation, which can realize one-time clamping and processing, thereby improving the processing efficiency of the convex surface of the C / C composite material plug cone, and a processing method therefor.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: a fixture for processing the convex surface of a C / C composite material plug cone, including a bottom plate, and a support device for preliminarily supporting the plug cone is provided on the bottom plate corresponding to the axial two ends of the plug cone; the concave curved surface of the plug cone is supported on the support device, so that the concave curved surface of the plug cone serves as the support bottom surface of the plug cone;

[0006] A clamping mechanism for fixing the end of the plug cone is provided at one axial end of the plug cone, and a pushing device for pushing the plug cone tightly into the C-shaped clamping opening of the clamping mechanism is provided at the other axial end of the plug cone; a pressing device for pressing the plug cone tightly on the support device is installed on the convex curved surface of the plug cone;

[0007] A balance support device is provided on the bottom plate corresponding to the two circumferential end faces of the curved surface of the plug cone. The balance support device provides a support force for ensuring the circumferential balance of the plug cone during processing after the clamping mechanism, the pushing device and the pressing device fix and press the plug cone;

[0008] It further includes a support rod member for preventing the deformation of the plug taper during the processing. The support rod member is installed on the concave curved surface of the plug taper, that is, on the bottom plate corresponding to the support bottom surface of the plug taper. The support rod members are arranged in pairs and equidistantly on both sides of the axis of the plug taper, and the ends of the support rod members are in contact with the concave curved surface of the plug taper.

[0009] Furthermore, the support device is a pair of support plates respectively arranged at the two axial ends of the plug taper. The width of the support plate is matched with the circumferential width of the plug taper. An installation inclined surface adapted to the concave curved surface of the plug taper is provided on the end surface of the support plate in contact with the plug taper.

[0010] It also includes that at the top of at least one support plate in contact with the plug taper, there is a support block for supporting the top of the concave curved surface of the plug taper, and a support curved surface matching the top curved surface of the concave curved surface is provided on the top surface of the support block.

[0011] Furthermore, the clamping mechanism includes an inclined support. The inclined support is installed on the support device through at least a pair of bolts. The included angle between the inclined installation axis of the inclined support and the radian center line of the concave curved surface of the plug taper is a, so as to ensure the adaptive clamping of the clamping mechanism to the plug taper.

[0012] An inverted L-shaped bracket is installed on the inclined support. One end of the inverted L-shaped bracket is fixed on the top surface of the inclined support. The other end of the inverted L-shaped bracket is provided with a pressing block through a first screw nut. One end of the screw of the first screw nut passes through the inverted L-shaped bracket, and the nut of the first screw nut is installed at one end of the screw passing through the inverted L-shaped bracket. The pressing block is fixedly installed at the other end of the screw.

[0013] The first screw nut, the pressing block, the inverted L-shaped bracket and the top surface of the inclined support form a C-shaped clamping opening for clamping the axial end face of the plug taper. After the pushing device pushes the axial end of the plug taper tightly into the C-shaped clamping opening, the clamping strength of the C-shaped clamping opening on the plug taper is adjusted through the first screw nut and the pressing block.

[0014] Furthermore, the pushing device includes a pushing plate. One end of the pushing plate is pressed on the axial end face of the plug taper. The other end of the pushing plate is installed on the support device through an upper screw and a lower screw. The upper screw is used for pressing and fixing the pushing plate, and the lower screw is used for stabilizing the pushing plate surface to prevent the plate surface from warping.

[0015] Furthermore, the included angle a is 30° - 60°.

[0016] Furthermore, the pressing device includes a pressing plate with a width matching the circumferential width of the plug taper. Both ends of the pressing plate are installed on the machine tool or the bottom plate through a second screw nut.

[0017] The pressing plate has a concave surface adapted to the convex curved surface of the plug cone member, and the concave surface is in contact with the convex curved surface when the plug cone member is pressed.

[0018] Further, the balance support device is arranged on the bottom plate corresponding to the central position of the axial length of the plug cone member;

[0019] The balance support device includes a pair of balance support blocks corresponding to the circumferential two end faces of the plug cone member. The pair of balance support blocks are rotatably installed at both ends of the support shaft through bearings. The support shaft is installed on the bottom plate through a bearing seat. The pair of balance support blocks are connected to the bottom plate through tension springs;

[0020] At one end of the balance support block, there is a convex surface in contact with the circumferential end face of the plug cone member. At the other end of the balance support block, there is a first screw. On the bottom plate, there is a second screw. Both ends of the tension spring are installed on the first screw and the second screw, so that the convex surface of the balance support block is in a higher position, and the balance support block provides an upward supporting force for the plug cone member.

[0021] Further, the support rod member is a cylindrical support rod with a ball head top structure. The ball heads of a pair of support rod members are symmetrically in contact with the concave curved surfaces on both sides of the central axis of the plug cone member. The radial angle of the ball heads at the contact points of the concave curved surfaces is 45 - 60 degrees, which is used to prevent the deformation of the plug cone member during the processing.

[0022] The present invention also provides a processing method for the convex surface of a C / C composite material plug cone using the fixture, which is characterized by including the following steps:

[0023] First, fixedly install the bottom plate on the machine tool;

[0024] Secondly, place the concave curved surface of the plug cone member as the support surface on the support surface of the support plate. The concave vertex of the concave curved surface is placed corresponding to the support block, and then align it through a dial indicator or a micrometer to determine the position of the fixture and the plug cone member in the machine tool. Furthermore, adjust the pressing plate to press the plug cone member tightly in the C-shaped clamp;

[0025] Then, adjust a pair of bolts of the clamping mechanism to make the inclined support adapt to an angle of 30 - 60 degrees according to the radian of the plug cone member, and then tighten the first lead screw nut. At the same time, press the plug cone member through the lead screw nut by the pressing plate;

[0026] Next, install the support rod member to make the ball heads of the support rod member symmetrically in contact with the concave curved surfaces on both sides of the central axis of the plug cone member to ensure the smoothness of the processing surface during the processing; then hang both ends of the tension springs on both sides to the first screw and the second screw respectively, so that the balance support blocks at both ends tightly press both sides of the plug cone member to further fix the plug cone member;

[0027] Finally, rough milling is successively performed on the top surface, side surface, and end surface of the convex surface of the plug cone part; then, finish milling is performed on the plug cone part in the rough milling order, achieving one-time clamping from rough milling to finish milling of the plug cone part and avoiding repeated clamping errors.

[0028] Further, when there is a gap between the plug cone part and the support plate or support block, a gasket is added to make the two contact tightly.

[0029] The beneficial effects of the present invention are as follows: The present invention uses the clamping mechanism, pushing device, and pressing device to cooperate with each other to fix the C / C composite plug cone part on the base. At the same time, with the cooperation of the balance support device, the plug cone part arranged on the support device can maintain balance during processing, greatly improving the clamping efficiency of the plug cone part, and achieving rough milling and finish milling of the convex surface, outer side surface, and top surface of the plug cone part in one clamping process. The machined part surface after finish machining can be used as the reference for subsequent finish machining of the convex surface, reducing the positioning error caused by repeated clamping, improving the machining accuracy of the part, and also reducing the workload of workers and the error caused by multiple clamping to the part machining.

[0030] At the same time, by installing the support rod member on the bottom plate to better support the part, the rigidity of the part during processing is improved. The support rod member is a cylindrical rod structure with a spherical head top structure, which contacts the concave surface of the part. The support rod member not only plays a supporting role for the part during processing but also improves the rigidity of the workpiece, avoiding large deformation and machining vibration of the part during processing, resulting in part out-of-tolerance or even scrapping, and effectively improving the machining quality problem of the C / C composite plug cone part fixture. Description of the Drawings

[0031] Figure 1 It is the overall structural view of the fixture clamping the C / C composite plug cone part;

[0032] Figure 2 It is the structural schematic diagram of the fixture clamping the C / C composite plug cone part from another perspective.

[0033] In the figure: 1 - bottom plate; 2 - support device; 21 - support plate; 22 - support block; 23 - installation inclined surface; 3 - clamping mechanism; 31 - inclined support; 32 - pair of bolts; 33 - inverted L-shaped bracket; 34 - first lead screw nut; 35 - pressing block; 4 - pressing device; 41 - pressing plate; 42 - second lead screw nut; 43 - concave surface; 5 - plug cone part; 6 - support rod member; 7 - balance support device; 71 - support shaft; 72 - bearing seat; 73 - balance support block; 74 - first screw; 75 - second screw; 76 - tension spring; 8 - pushing device; 81 - pushing plate; 82 - upper screw; 83 - lower screw. Detailed Embodiments

[0034] The principles and features of the present invention will be described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0035] Example 1: As Figure 1 and Figure 2 shown, a C / C composite plug cone convex surface machining fixture includes a bottom plate 1. On the bottom plate 1 corresponding to the axial two ends of the plug cone part 5, there is a support device 2 for preliminarily supporting the plug cone part 5; the concave curved surface of the plug cone part 5 is supported on the support device 2, so that the concave curved surface of the plug cone part 5 serves as the support bottom surface of the plug cone part 5.

[0036] The support device 2 is a pair of support plates 21 respectively arranged at the axial two ends of the plug cone part 5. The width of the support plate 21 is set to match the circumferential width of the plug cone part 4. On the end face of the support plate 21 in contact with the plug cone part 4, there is an installation inclined surface 23 for adapting to the concave curved surface of the plug cone part 4.

[0037] It also includes that at the top of at least one support plate 21 in contact with the plug cone part 4, there is a support block 22 for cooperatively supporting the top of the concave curved surface of the plug cone part 4. On the top surface of the support block 22, there is a support curved surface matching the top curved surface of the concave curved surface.

[0038] At one axial end of the plug cone part 5, there is a clamping mechanism 3 for fixing the end of the plug cone part 5. At the other axial end of the plug cone part 5, there is a pushing device 8 for pushing the plug cone part 5 tightly into the C-shaped clamping mouth of the clamping mechanism 3; on the convex curved surface of the plug cone part 5, there is a pressing device 4 for pressing the plug cone part 5 onto the support device 2.

[0039] The clamping mechanism 3 includes an inclined support 31. The inclined support 31 is installed on the support device 2 through at least a pair of bolts 32. The included angle a between the inclined installation axis of the inclined support 31 and the radian midline of the concave curved surface of the plug cone part 5 is 30° - 60°, so as to ensure the adaptive clamping of the clamping mechanism 3 to the plug cone part 5.

[0040] An inverted L-shaped bracket 33 is installed on the inclined support 31. One end of the inverted L-shaped bracket 33 is fixed on the top surface of the inclined support 31. The other end of the inverted L-shaped bracket 33 is installed with a pressing block 35 through a first lead screw nut 34. One end of the lead screw of the first lead screw nut 34 passes through the inverted L-shaped bracket 33. The nut of the first lead screw nut 34 is installed at one end of the lead screw passing through the inverted L-shaped bracket 33, and the pressing block 35 is fixedly installed at the other end of the lead screw.

[0041] The top surfaces of the first lead screw nut 34, the pressing block 35, the inverted L-shaped bracket 33, and the inclined support 31 form a C-shaped clamping opening for clamping the axial end face of the plug cone part 5. After the pushing device 8 pushes the axial end of the plug cone part 5 tightly into the C-shaped clamping opening, the clamping strength of the C-shaped clamping opening on the plug cone part 5 is adjusted by the first lead screw nut 34 and the pressing block 35.

[0042] Balancing support devices 7 are provided on the bottom plate 1 corresponding to the two end faces in the circumferential direction of the curved surface of the plug cone part 5. The balancing support devices 7 provide a supporting force for ensuring the circumferential balance during the machining of the plug cone part 5 after the clamping mechanism 3, the pushing device 8, and the pressing device 4 fix and press the plug cone part 5.

[0043] The pushing device 8 includes a pushing plate 81. One end of the pushing plate 81 is pressed against the axial end face of the plug cone part 5, and the other end of the pushing plate 81 is installed on the support device 2 through an upper screw 82 and a lower screw 83. The upper screw 82 is used for tightly fixing the pushing plate 81, and the lower screw 83 is used to stabilize the surface of the pushing plate 81 to prevent the plate surface from warping. It also includes a support rod member 6 for preventing the deformation of the plug cone part 5 during the machining process. The support rod member 6 is installed on the concave curved surface of the plug cone part 4, that is, on the bottom plate 3 corresponding to the supporting bottom surface of the plug cone part 5. The support rod members 6 are arranged in pairs and at equal distances on both sides of the axis of the plug cone part 5, and the ends of the support rod members 6 are arranged in contact with the concave curved surface of the plug cone part 4.

[0044] The pressing device 4 includes a pressing plate 41 with a width matching the circumferential width of the plug cone part 5. Both ends of the pressing plate 41 are installed on the machine tool or the bottom plate 1 through the second lead screw nut 42; the pressing plate 41 has a concave surface 43 adapted to the convex curved surface of the plug cone part 5, and the concave surface 43 is arranged in contact with the convex curved surface when the plug cone part 5 is pressed.

[0045] The balancing support device 7 is arranged on the bottom plate 1 corresponding to the central position of the axial length of the plug cone part 5; the balancing support device 7 includes a pair of balancing support blocks 73 corresponding to the two end faces in the circumferential direction of the plug cone part 5. The pair of balancing support blocks 73 are rotatably installed at both ends of the support shaft 71 through bearings. The support shaft 71 is installed on the bottom plate 1 through a bearing seat 72. The pair of balancing support blocks 73 are connected to the bottom plate 1 through a tension spring 76; a convex surface in contact with the circumferential end face of the plug cone part 5 is provided at one end of the balancing support block 73, a first screw 74 is provided at the other end of the balancing support block 73, and a second screw 75 is provided on the bottom plate 1. Both ends of the tension spring 76 are installed on the first screw 74 and the second screw 75, so that the convex surface of the balancing support block 73 is in a relatively high position, and the balancing support block 73 provides an upward supporting force for the plug cone part 5.

[0046] The support rod member 6 is a cylindrical support rod with a ball head top structure. The ball heads of a pair of support rod members 6 are symmetrically in contact with the concave curved surfaces on both sides of the central axis of the plug taper member 5. The radial angle of the ball heads at the contact points of the concave curved surfaces is 45 to 60 degrees, which is used to prevent the deformation of the plug taper member 5 during the processing.

[0047] Embodiment 2: The present invention also provides a method for machining the convex surface of a C / C composite plug taper using a fixture, which is characterized by including the following steps:

[0048] First, fixedly install the bottom plate 1 on the machine tool;

[0049] Secondly, place the concave curved surface of the plug taper member 5 as the support surface on the support surface of the support plate 21. The concave vertex of the concave curved surface corresponds to the placement of the support block 22, and then align it through a dial indicator or a micrometer to determine the position of the fixture and the plug taper member 5 in the machine tool. Furthermore, adjust the tightening plate 81 to press the plug taper member 5 tightly in the C-shaped clamp;

[0050] Then, adjust a pair of bolts 32 of the clamping mechanism 3 to make the inclined support 31 adapt to an angle of 30 - 60 degrees according to the radian of the plug taper member 5, and then tighten the first lead screw nut 34. At the same time, press the plug taper member 5 through the lead screw nut 42 with the pressing plate 41;

[0051] When there is a gap between the plug taper member 5 and the support plate 21 or the support block 22, make them in close contact by adding gaskets.

[0052] Next, install the support rod member 6 to make the ball heads of the support rod member 6 symmetrically in contact with the concave curved surfaces on both sides of the central axis of the plug taper member 5 to ensure the smoothness of the machining surface during the processing; then hang the two ends of the two side tension springs 76 onto the first screw 74 and the second screw 75 respectively, so that the two ends of the balance support blocks 73 press tightly against both sides of the plug taper member 5 to further fix the plug taper member 5, that is, make the convex surfaces of the balance support blocks 73 in a relatively high position. The balance support blocks 73 on both ends will push up the plug taper member 5 to play a fixing role.

[0053] Finally, rough mill the top surface, side surface and end surface of the convex surface of the plug taper member 5 in sequence; then, according to the rough milling sequence, finish mill the plug taper member 5, realizing the one-time clamping from rough milling to finish milling of the plug taper member 5 and avoiding the repeated clamping error.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A C / C composite material plug cone convex surface processing fixture, characterized in that, It includes a bottom plate (1), and support devices (2) for preliminarily supporting a plug cone member (5) are provided on the bottom plate (1) corresponding to the axial two ends of the plug cone member (5); the concave curved surface of the plug cone member (5) is supported on the support device (2), so that the concave curved surface of the plug cone member (5) serves as the support bottom surface of the plug cone member (5). A clamping mechanism (3) for fixing the end of the plug cone member (5) is provided at one axial end of the plug cone member (5), and a pushing device (8) for pushing the plug cone member (5) tightly into the C-shaped clamping opening of the clamping mechanism (3) is provided at the other axial end of the plug cone member (5); a pressing device (4) for pressing the plug cone member (5) tightly on the support device (2) is installed on the convex curved surface of the plug cone member (5). Balanced support devices (7) are provided on the bottom plate (1) corresponding to the two circumferential end faces of the curved surface of the plug cone member (5). The balanced support devices (7) provide a support force for ensuring the circumferential balance during the processing of the plug cone member (5) after the clamping mechanism (3), the pushing device (8) and the pressing device (4) fix and press the plug cone member (5). It further includes a support rod member (6) for preventing the plug cone member (5) from deforming during the processing. The support rod member (6) is installed on the concave curved surface of the plug cone member (5), that is, on the bottom plate (1) corresponding to the support bottom surface of the plug cone member (5). The support rod members (6) are arranged in pairs and equidistantly on both sides of the axis of the plug cone member (5), and the ends of the support rod members (6) are in contact with the concave curved surface of the plug cone member (5); the support device (2) is a pair of support plates (21) respectively provided at the two axial ends of the plug cone member (5). The width of the support plate (21) is matched with the circumferential width of the plug cone member (5), and an installation inclined surface (23) adapted to the concave curved surface of the plug cone member (5) is provided on the end surface of the support plate (21) in contact with the plug cone member (5). It further includes that a support block (22) for cooperatively supporting the top of the concave curved surface of the plug cone member (5) is provided at the top of at least one support plate (21) in contact with the plug cone member (5), and a support curved surface matching the top curved surface of the concave curved surface is provided on the top surface of the support block (22). The balanced support device (7) is provided on the bottom plate (1) corresponding to the central position of the axial length of the plug cone member (5). The balanced support device (7) includes a pair of balanced support blocks (73) corresponding to the two circumferential end faces of the plug cone member (5). The pair of balanced support blocks (73) are rotatably installed at both ends of a support shaft (71) through bearings. The support shaft (71) is installed on the bottom plate (1) through a bearing seat (72), and the pair of balanced support blocks (73) are connected to the bottom plate (1) through a tension spring (76). One end of the described balance support block (73) is provided with a convex surface that contacts the circumferential end surface of the plug cone member (5). The other end of the balance support block (73) is provided with a first screw (74), and a second screw (75) is provided on the bottom plate (1). Both ends of the tension spring (76) are installed on the first screw (74) and the second screw (75), so that the convex surface of the balance support block (73) is in a higher position, and the balance support block (73) provides an upward supporting force for the plug cone member (5).

2. The C / C composite material plug cone convex surface processing fixture according to claim 1, characterized in that, The described clamping mechanism (3) includes an inclined support (31). The inclined support (31) is installed on the support device (2) through at least a pair of bolts (32). The included angle between the inclined installation axis of the inclined support (31) and the arc midline of the concave curved surface of the plug cone member (5) is a, so as to ensure the adaptive clamping of the clamping mechanism (3) to the plug cone member (5). An inverted L-shaped bracket (33) is installed on the inclined support (31). One end of the inverted L-shaped bracket (33) is fixed to the top surface of the inclined support (31). The other end of the inverted L-shaped bracket (33) is installed with a pressing block (35) through a first lead screw nut (34). One end of the lead screw of the first lead screw nut (34) passes through the inverted L-shaped bracket (33), and the nut of the first lead screw nut (34) is installed at one end of the lead screw passing through the inverted L-shaped bracket (33). The pressing block (35) is fixedly installed at the other end of the lead screw. The first lead screw nut (34), the pressing block (35), the inverted L-shaped bracket (33) and the top surface of the inclined support (31) form a C-shaped clamping opening for clamping the axial end surface of the plug cone member (5). After the pushing device (8) pushes the axial end of the plug cone member (5) tightly into the C-shaped clamping opening, the clamping strength of the C-shaped clamping opening on the plug cone member (5) is adjusted through the first lead screw nut (34) and the pressing block (35).

3. The C / C composite material plug cone convex surface processing fixture according to claim 1, characterized in that, The described pushing device (8) includes a pushing plate (81). One end of the pushing plate (81) is pressed against the axial end surface of the plug cone member (5). The other end of the pushing plate (81) is installed on the support device (2) through an upper screw (82) and a lower screw (83). The upper screw (82) is used for pressing and fixing the pushing plate (81), and the lower screw (83) is used to stabilize the surface of the pushing plate (81) to prevent the plate surface from warping.

4. The C / C composite material plug cone convex surface processing fixture according to claim 2, characterized in that, The included angle a is 30° - 60°.

5. The C / C composite material plug cone convex surface processing fixture according to claim 1, characterized in that, The described pressing device (4) includes a pressing plate (41) that matches the circumferential width of the plug cone member (5). Both ends of the pressing plate (41) are installed on the machine tool or the bottom plate (1) through a second lead screw nut (42). The pressing plate (41) has a concave surface (43) that is adapted to the convex curved surface of the plug cone member (5), and when the plug cone member (5) is pressed, the concave surface (43) is in contact with the convex curved surface.

6. The C / C composite material plug cone convex surface processing fixture according to claim 1, characterized in that, The described support rod member (6) is a cylindrical support rod with a ball head top structure. The ball heads of a pair of support rod members (6) are symmetrically in contact with the concave curved surfaces on both sides of the central axis of the plug cone member (5). The radial included angle of the ball heads at the contact points of the concave curved surfaces is 45 - 60 degrees, which is used to prevent the deformation of the plug cone member (5) during the processing.

7. A processing method for the C / C composite material plug cone convex surface using the fixture according to any one of claims 1-6, characterized in that, It includes the following steps: First, fixedly install the bottom plate (1) on the machine tool; Second, place the concave curved surface of the plug cone part (5) as the supporting surface on the supporting surface of the supporting plate (21), place the concave vertex of the concave curved surface corresponding to the supporting block (22), and then align it with a dial indicator or a micrometer to determine the position of the fixture and the plug cone part (5) in the machine tool. Furthermore, adjust the tightening plate (81) to press the plug cone part (5) tightly in the C-shaped clamp; Then, adjust a pair of bolts (32) of the clamping mechanism (3) to make the inclined support (31) adapt to an angle of 30 - 60 degrees according to the radian of the plug cone part (5), and then tighten the first lead screw nut (34). At the same time, press the plug cone part (5) through the lead screw nut (42) with the pressing plate (41); Next, install the support rod member (6) to make the ball head of the support rod member (6) symmetrically contact the concave curved surfaces on both sides of the central axis of the plug cone part (5) to ensure the smoothness of the machining surface during the machining process; then hang the two ends of the tension springs (76) on the first screw (74) and the second screw (75) respectively, and make the balance support blocks (73) at both ends press tightly against both sides of the plug cone part to further fix the plug cone part (5); Finally, rough mill the top surface, side surface and end surface of the convex curved surface of the plug cone part (5) in sequence; then, carry out finish milling on the plug cone part (5) according to the rough milling sequence, realizing one-time clamping from rough milling to finish milling of the plug cone part (5) and avoiding repeated clamping errors.

8. The processing method for the C / C composite material plug cone convex surface according to claim 7, characterized in that: When there is a gap between the plug cone part (5) and the supporting plate (21) or the supporting block (22), add a gasket to make the two contact tightly.

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