A combustion chamber flame tube pre-evaporation tube installation fixture

Abstract

The present invention relates to an installation fixture for pre-evaporation pipes of a combustion chamber flame tube, which includes a chassis, a positioning disc, a positioning bracket, a square shaft and a setscrew. Ten receiving teeth are convexly provided radially outward along the edge of the chassis, and a hollow part is formed between adjacent two receiving teeth; five sliders are evenly distributed along the edge of the positioning disc; a square shaft and a liftable setscrew are arranged along the axial direction of the positioning disc on each slider, and the bottom end of the square shaft is connected to a positioning bracket for supporting the pre-evaporation pipe; during clamping, five pre-evaporation pipes are placed on corresponding positioning brackets, and the pre-evaporation pipes are clamped by the setscrew and the positioning bracket; then the positioning disc is coaxially arranged above the combustion chamber flame tube, the setscrew, the square shaft, the positioning bracket and the pre-evaporation pipe are inserted into the annular cavity of the combustion chamber flame tube, the inlet pipe of the pre-evaporation pipe is inserted into the welding hole at the bottom of the combustion chamber flame tube, and the welding hole and the inlet pipe are welded and fixed at the corresponding hollow part of the chassis.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine part processing, and particularly to a pre-evaporation tube installation fixture for a combustion chamber flame tube. Background Art

[0002] The combustion chamber of a certain type of engine is an annular reflux combustion chamber with pre-evaporation tubes. Its core component, the flame tube, is a short-ring type thin-wall structure. As Figure 1 shown, the combustion chamber flame tube is composed of an annular inner side wall 11, an arc-shaped bottom wall 13, and an annular outer side wall 12. More than ten thousand cooling holes, main combustion holes, and dilution holes are distributed on the surfaces of the annular inner side wall 11 and the annular outer side wall 12. Ten welding holes 15 are evenly distributed on the arc-shaped bottom wall 13. A narrow annular cavity 14 is formed between the annular inner side wall 11 and the annular outer side wall 12; ten pre-evaporation tubes 2 need to be assembled in the annular cavity 14 of each combustion chamber flame tube. As Figure 2 shown, the pre-evaporation tube 2 is a tee-shaped three-way pipeline arranged in a T shape, including a connecting pipe 24 and an inlet pipe 21, a first outlet pipe 22, and a second outlet pipe 23 placed on the same side of the connecting pipe. The inlet pipe communicates with the middle of the connecting pipe 24. The first outlet pipe 22 and the second outlet pipe 23 are symmetrically arranged on both sides of the inlet pipe 21 and communicate with the ends of the connecting pipe 24. The length of the inlet pipe 21 is greater than the lengths of the two outlet pipes. After the inlet pipe 21 is inserted into the welding hole 15 in the annular cavity 14, it is welded and fixed, so that the outlets of the 20 outlet pipes are evenly distributed in the annular cavity 14. The position accuracy of the pre-evaporation tube 2 after welding is relatively critical. If it does not cooperate well with the nozzle, it will affect the evaporation rate of the fuel in the pre-evaporation tube 2, and further affect the OTDF (Outlet Temperature Distribution Factor), and carbon deposition will occur. At the same time, the position of the outlet of the pre-evaporation tube 2 and the flow direction of the outlet air flow have a great influence on the main combustion zone. If the outlet of the pre-evaporation tube 2 is too close to the arc top of the flame tube, the residence time of the oil-gas mixture in the pre-evaporation tube 2 in the main combustion zone will be shortened, which will also damage the flow field of the recirculation zone, resulting in incomplete combustion of the fuel in the main combustion zone and affecting the OTDF.

[0003] Limited by the size of the annular cavity 14, it is impossible to directly send the pre-evaporation tube into the annular cavity 14 by hand and make large adjustments to the pre-evaporation tube 2 in the annular cavity 14. Therefore, the assembly of the above parts is not easy to implement, the processing efficiency is low, and the qualified rate is low. Therefore, designing an installation fixture that can send the pre-evaporation tube into the annular cavity according to a preset position is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a pre-evaporation tube installation fixture for a combustion chamber flame tube with a simple structure and easy assembly.

[0005] To solve the above technical problems, the pre-evaporation tube installation fixture for the combustion chamber flame tube provided by the present invention includes a chassis, a positioning disk, a positioning bracket, a square shaft, and a setscrew. Ten receiving teeth are protruded radially outward along the edge of the chassis, and the receiving teeth are evenly distributed on the edge of the chassis, and a hollow portion is formed between adjacent receiving teeth. When the combustion chamber flame tube is coaxially arranged on the chassis, the arc-shaped bottom wall of the combustion chamber flame tube contacts the chassis, and each welding hole on the arc-shaped bottom wall is respectively placed in the hollow portion between adjacent receiving teeth. Five sliders are evenly distributed on the edge of the positioning disk, and each slider protrudes radially outward along the edge of the positioning disk. A square shaft and a liftable setscrew are arranged along the axial direction of the positioning disk on each slider. The bottom end of the square shaft is connected to the positioning bracket. The positioning bracket includes a connecting portion, and support portions are respectively arranged at both ends on one side of the connecting portion, and a hollow area is formed between the two support portions. During clamping, five pre-evaporation tubes are placed on corresponding positioning brackets, the first outlet tubes and the second outlet tubes of each pre-evaporation tube are respectively placed on the two support portions, and the inlet tube passes through the hollow area. The bottom end of the setscrew passes through the slider and is placed above the connecting tube of the pre-evaporation tube, so that the pre-evaporation tube can be clamped after the setscrew descends. Then the positioning disk is coaxially arranged above the combustion chamber flame tube, the setscrew, the square shaft, the positioning bracket, and the pre-evaporation tube are inserted into the annular cavity of the combustion chamber flame tube, the inlet tube of the pre-evaporation tube is inserted into the welding hole at the bottom of the combustion chamber flame tube, and the welding hole and the inlet tube are welded and fixed at the corresponding hollow portion of the chassis. After welding the five pre-evaporation tubes, the positioning disk is removed, the setscrew, the square shaft, and the positioning bracket are taken out, and then five pre-evaporation tubes are clamped and the above actions are repeated to complete the assembly of ten pre-evaporation tubes.

[0006] Furthermore, the pre-evaporation tube installation fixture for the combustion chamber flame tube further includes a central shaft. A central hole of the chassis is provided at the center of the chassis, and a central hole of the positioning disk is provided at the center of the positioning disk. During assembly, the bottom end of the central shaft is placed in the central hole of the chassis, and the positioning disk is connected to the central shaft through the central hole of the positioning disk, so that the positioning disk and the chassis are coaxially arranged.

[0007] Furthermore, 3 to 5 positioning platforms are protruded along the axial direction on the edge of the chassis, and each positioning platform is arranged on non-adjacent receiving teeth. Threaded holes are arranged along the radial direction of the chassis on each positioning platform, so that when the combustion chamber flame tube is placed on the chassis, positioning bolts are screwed into the threaded holes to limit and fix the combustion chamber flame tube.

[0008] Furthermore, a first limiting groove is provided on one side of the central hole of the chassis, a second limiting groove and a third limiting groove are provided on one side of the central hole of the positioning disk, and limiting blocks that are clamped and matched with each limiting groove are respectively provided at the bottom and the top of the central shaft, so that the central shaft is limited after being assembled with the chassis and the positioning disk, and mutual rotation between the positioning disk and the chassis during assembly is avoided, which affects the alignment of the inlet tube of the pre-evaporation tube with the welding hole.

[0009] Furthermore, the angles of the second limiting groove and the third limiting groove on the circumference of the positioning disk differ by 36°. The positioning disk makes the second limiting groove and the third limiting groove engage with the limiting block at the top of the central axis twice respectively, so that the positions of the sliders during the two assemblies of the positioning disk differ by 36°. This allows for the rapid assembly of 10 pre-evaporation tubes, enabling the 10 pre-evaporation tubes to be quickly placed in their corresponding positions and improving the assembly efficiency.

[0010] Furthermore, the square shaft includes a rectangular parallelepiped-shaped square shaft body. A first square hole is penetrated through the slider, and a second square hole is provided at the connecting portion of the positioning bracket. During assembly, the upper part of the square shaft body is inserted into the first square hole, and the lower part of the square shaft body is inserted into the second square hole. The cooperation of the square hole and the square shaft prevents the square shaft from rotating during assembly, which may cause the positioning bracket to shift and affect the alignment of the inlet pipe of the pre-evaporation tube with the welding hole.

[0011] Furthermore, a plug hole perpendicular to the second square hole is also provided at the connecting portion of the positioning bracket. The plug hole penetrates through the second square hole. An installation hole adapted to the plug hole is provided at the lower part of the square shaft body. When the lower part of the square shaft body is placed in the second square hole, the installation hole and the plug hole are aligned. A plug pin is inserted into the installation hole and the plug hole to limit and fix the square shaft and the positioning bracket. The length of the plug pin is greater than the length of the plug hole, so that the end of the plug pin is located outside the plug hole. After the pre-evaporation tube is welded, it is convenient to pull out the plug pin to separate the square shaft and the positioning bracket.

[0012] Furthermore, a concave area adapted to the tube ends of the first outlet pipe and the second outlet pipe of the pre-evaporation tube is provided on the upper end surface of the supporting portion of the positioning bracket. When the pre-evaporation tube is placed on the positioning bracket, the first outlet pipe and the second outlet pipe can quickly align with the concave area, improving the clamping efficiency.

[0013] Furthermore, the combustion chamber flame tube pre-evaporation tube installation fixture further includes an arc-shaped clamp. The arc-shaped portion at the front end of the clamp is adapted to the shape of the connecting pipe of the pre-evaporation tube. An elastic spherical hole is provided at the tail end of the arc-shaped clamp. A ball is fixedly provided at the bottom end of the top screw. During assembly, the ball is squeezed into the spherical hole so that the top screw is connected to the arc-shaped clamp, and the arc-shaped clamp can rotate around the ball. When the top screw is inserted into the annular cavity for lifting and lowering, the arc-shaped portion of the arc-shaped clamp can more easily hold against the connecting pipe of the pre-evaporation tube, and the rotation of the top screw will not affect the pre-evaporation tube.

[0014] Furthermore, the outer diameter of the positioning disk is the same as the outer diameter of the annular inner side wall of the combustion chamber flame tube. An annular step portion is provided along the edge at the bottom end of the positioning disk. When the positioning disk is placed above the combustion chamber flame tube, the annular inner side wall of the combustion chamber flame tube supports the annular step portion of the positioning disk.

[0015] The usage method of the above combustion chamber flame tube pre-evaporation tube installation fixture includes the following steps:

[0016] A. Put the chassis on the central shaft so that the limit block at the bottom of the central shaft is placed in the first limit groove; place the combustion chamber flame tube on the chassis so that the welding holes on the arc-shaped bottom wall are placed in the hollow part between two adjacent receiving teeth; fix the combustion chamber flame tube and the chassis through the positioning bolts.

[0017] B. Assemble the corresponding square shaft, slider, positioning bracket and positioning disc, and support the first group of 5 pre-evaporation tubes by the positioning bracket respectively. Adjust the setscrew so that the arc-shaped clamp limits and fixes the pre-evaporation tubes.

[0018] C. Put the positioning disc on the upper part of the central shaft so that the square shaft, positioning bracket and setscrew are inserted into the annular cavity as a whole. The second limit groove is clamped and matched with the limit block on the upper part of the central shaft to complete the insertion and matching of the first group of 5 pre-evaporation tubes and the welding holes.

[0019] D. Weld and fix the inlet tubes inserted into the welding holes one by one in the hollow part to complete the assembly of the first group of 5 non-adjacent pre-evaporation tubes.

[0020] E. After welding the first group of 5 pre-evaporation tubes, use tweezers to pull out the insertion pin so that the square shaft and the positioning bracket can be separated. Disconnect the positioning disc from the central shaft so that the setscrew and the square shaft are pulled out of the annular cavity, and then take out the positioning bracket in the annular cavity.

[0021] F. Assemble the square shaft, slider, positioning bracket and positioning disc again, and support the second group of 5 pre-evaporation tubes by the positioning bracket respectively. Adjust the setscrew so that the arc-shaped clamp limits and fixes the pre-evaporation tubes.

[0022] G. Put the positioning disc on the upper part of the central shaft so that the square shaft, positioning bracket and setscrew are inserted into the annular cavity as a whole. The third limit groove is clamped and matched with the limit block on the upper part of the central shaft to complete the insertion and matching of the second group of 5 pre-evaporation tubes and the welding holes.

[0023] H. Weld and fix the inlet tubes inserted into the welding holes one by one in the hollow part to complete the assembly of the second group of 5 pre-evaporation tubes.

[0024] I. After welding the second group of 5 pre-evaporation tubes, use tweezers to pull out the insertion pin so that the square shaft and the positioning bracket can be separated. Disconnect the positioning disc from the central shaft so that the setscrew and the square shaft are pulled out of the annular cavity, and then take out the positioning bracket in the annular cavity, and separate the chassis and the combustion chamber flame tube to complete the assembly of all 10 pre-evaporation tubes.

[0025] Technical effects of the invention: (1) For the pre-evaporation tube installation fixture of the combustion chamber flame tube of the present invention, compared with the prior art, a receiving tooth is provided at the edge of the chassis. When the combustion chamber flame tube is placed on the chassis, it is supported by the receiving tooth, and the welding hole is placed in the hollow part between adjacent receiving teeth, which can reduce the weight of the chassis and facilitate welding; (2) The use of a square shaft, a positioning bracket and a setscrew in cooperation enables the pre-evaporation tube to be placed on the positioning bracket and limited and fixed before entering the annular cavity, facilitating the overall insertion of the square shaft, the positioning bracket and the setscrew into the annular cavity; (3) The cooperation of the square shaft through the square hole and the slider and the positioning bracket can prevent the positioning bracket from rotating in the annular cavity and affecting the assembly efficiency; (4) The cooperation of the setscrew through the clamp and the ball, and the setting of the arc part can easily clamp the clamp on the connecting pipe of the pre-evaporation tube, and the pre-evaporation tube will not rotate when the setscrew rotates; (5) By respectively providing limit grooves on the chassis and the positioning plate, the insertion positions of the square shaft, the positioning bracket and the setscrew can be conveniently limited; (6) The positioning bracket and the square shaft are limited and fixed by the insertion pin. After the pre-evaporation tube is welded and fixed, the insertion pin can be conveniently taken out, the positioning bracket and the square shaft are separated, and it is convenient to take out the positioning bracket and the square shaft from the annular cavity. Description of the Drawings

[0026] The present invention will be further described in detail below in conjunction with the drawings of the specification:

[0027] Figure 1 is a schematic structural diagram of the assembled combustion chamber flame tube and pre-evaporation tube in the prior art;

[0028] Figure 2 is a schematic structural diagram of the pre-evaporation tube;

[0029] Figure 3 is a schematic cross-sectional structural diagram of the assembled pre-evaporation tube installation fixture of the combustion chamber flame tube of the present invention and the pre-evaporation tube;

[0030] Figure 4 is a top view of the assembled pre-evaporation tube installation fixture of the combustion chamber flame tube of the present invention and the pre-evaporation tube;

[0031] Figure 5 is a schematic structural diagram of the chassis of the present invention;

[0032] Figure 6 is a schematic structural diagram of the positioning bracket of the present invention;

[0033] Figure 7 is a schematic structural diagram of the square shaft of the present invention;

[0034] Figure 8 is a schematic structural diagram of the setscrew of the present invention.

[0035] In the figure: annular inner wall 11, annular outer wall 12, arc bottom wall 13, annular cavity 14, welding hole 15, pre-evaporation tube 2, inlet tube 21, first outlet tube 22, second outlet tube 23, connecting tube 24, chassis 3, receiving teeth 31, hollowed-out part 32, positioning platform 33, positioning bolt 34, chassis central hole 35, first limiting groove 36, positioning disk 4, slider 41, pressing plate 42, limiting pin 43, positioning nut 44, screw 45, fixing pin 46, first square hole 47, annular step part 48, U-shaped groove 49, central shaft 5, positioning bracket 6, connecting part 61, supporting part 62, sunken area 63, second square hole 64, insertion hole 65, insertion pin 66, hollowed-out area 67, square shaft 7, square shaft body 71, threaded section 72, mounting hole 73, top screw 8, clamp 81, ball 82, end cap 83, positioning disk central hole 9, second limiting groove 91, third limiting groove 92. Specific embodiments

[0036] Embodiment 1

[0037] As Figures 3 to 8 shown, the pre-evaporation tube installation fixture for the combustion chamber flame tube of this embodiment includes a chassis 3, a positioning disk 4, a positioning bracket 6, a central shaft 5, a square shaft 7 and a top screw 8. 10 receiving teeth 31 protrude radially outward along the edge of the chassis 3. The receiving teeth 31 are evenly distributed on the edge of the chassis 3 so that the angle between adjacent receiving teeth 31 is 36°. A hollowed-out part 32 is formed between adjacent receiving teeth 31; 3 positioning platforms 33 protrude axially along the edge of the chassis 3. Each positioning platform 33 is arranged on non-adjacent receiving teeth 31. Screw holes are arranged radially along the chassis 3 on each positioning platform 33. When the combustion chamber flame tube is coaxially arranged on the chassis 3, the arc bottom wall 13 of the combustion chamber flame tube contacts the chassis 3, and each welding hole 15 on the arc bottom wall 13 is respectively placed in the hollowed-out part 32 between adjacent receiving teeth 31. A positioning bolt 34 is screwed into the screw hole to limit and fix the combustion chamber flame tube; 5 sliders 41 are evenly distributed on the edge of the positioning disk 3. Each slider 41 protrudes radially outward along the edge of the positioning disk 4, and each slider 41 can slide radially along the positioning disk 4 to adjust the position of the slider 41. Pressing plates 42 with U-shaped grooves 49 are arranged on the positioning disk 4. The two sides of the U-shaped groove 49 of each pressing plate 42 are fixedly connected to the positioning disk 4 through screws 45 respectively. The slider 41 is pressed in the U-shaped groove 49 of the pressing plate 42. Through holes are also arranged on each slider 41 and the positioning disk 4. When the slider 41 moves to align the through hole on the slider 41 with the through hole on the positioning disk 4, a limiting pin 43 is used to limit the slider 41 and the positioning disk 4 to prevent the slider 41 from sliding radially along the positioning disk 4, but the slider 41 can rotate around the limiting pin 43 under the action of an external force to finely adjust the position of the slider 41.

[0038] On each slider 41, a square shaft 7 and a liftable setscrew 8 are axially arranged along the positioning disc 4. The bottom end of the square shaft 7 is connected to the positioning bracket 6. The positioning bracket 6 includes a connecting portion 61. At both ends on one side of the connecting portion 61, support portions 62 are respectively arranged. A hollow area 67 is formed between the two support portions 62. On the upper end surface of the support portion 62, a recessed area 63 adapted to the tube ends of the first outlet pipe 22 and the second outlet pipe 23 of the pre-evaporation tube 2 is provided. During clamping, the pre-evaporation tube 2 is placed on the corresponding positioning bracket 6. The first outlet pipe 22 and the second outlet pipe 23 of each pre-evaporation tube 2 are respectively placed on the recessed areas 63 of the two support portions, and the inlet pipe 21 passes through the hollow area 67 and is arranged.

[0039] The square shaft 7 includes a square shaft body 71 in the shape of a cuboid. A threaded section 72 is provided at the top of the square shaft body 71. A first square hole 47 is penetrated through the slider 41. A second square hole 64 is provided in the connecting portion 61 of the positioning bracket 6. The connecting portion 61 of the positioning bracket 6 is further provided with a plugging hole 65 perpendicular to the second square hole 64. The plugging hole 65 passes through the second square hole 64. An installation hole 73 adapted to the plugging hole 65 is provided at the lower part of the square shaft body 71. During assembly, the upper part of the square shaft body 71 is inserted into the first square hole 47, and the threaded section 72 passes through the first square hole 47 and is placed on the upper side of the slider 41. By using a positioning nut 44 that is threadedly engaged with the threaded section 72, the square shaft 7 and the slider 41 can be limited to prevent the square shaft 7 from moving. The lower part of the square shaft body 71 is inserted into the second square hole 64. By using the cooperation of the square hole and the square shaft 7, the square shaft 7 will not rotate during the assembly process, causing the positioning bracket 6 to shift and affecting the alignment of the inlet pipe 21 of the pre-evaporation tube 2 with the welding hole. And when the lower part of the square shaft body 7 is placed in the second square hole 64, the installation hole 73 and the plugging hole 65 are aligned. A plugging pin 66 is used to insert into the installation hole 73 and the plugging hole 65 to limit and fix the square shaft 7 and the positioning bracket 6. The length of the plugging pin 66 is greater than the length of the plugging hole 65, so that the end of the plugging pin 66 is placed outside the plugging hole 65. After the pre-evaporation tube 2 is welded, it is convenient to use an external pair of tweezers to pull out the plugging pin 66, so that the square shaft 7 and the positioning bracket 6 are separated.

[0040] The setscrew 8 is in threaded fit with the slider 41. The bottom end of the setscrew 8 passes through the slider 41 and is placed above the communicating pipe 24 of the pre-evaporation pipe 2. A ball 82 is fixedly arranged at the bottom end of the setscrew 8, and an end cap 83 is fixedly arranged at the top end of the setscrew 8. Rotating the end cap 83 can control the lifting of the setscrew. The combustion chamber flame tube pre-evaporation pipe installation fixture further includes an elastic plastic arc-shaped clamp 81. The arc-shaped part at the front end of the clamp 81 is adapted to the shape of the communicating pipe 24 of the pre-evaporation pipe. An elastic spherical hole is arranged at the tail end of the arc-shaped clamp 81. During assembly, the ball 82 is squeezed into the spherical hole so that the setscrew 8 is connected to the plastic arc-shaped clamp 81, and the plastic arc-shaped clamp 81 can rotate around the ball 82. When the setscrew 8 is inserted into the annular cavity 14 for lifting and lowering, the arc-shaped part of the plastic arc-shaped clamp 81 can more easily hold against the communicating pipe 24 of the pre-evaporation pipe 2, and the rotation of the setscrew 8 will not affect the pre-evaporation pipe 2.

[0041] A chassis center hole 35 is arranged at the center of the chassis 3. A first limiting groove 36 is arranged on one side of the chassis center hole 35. A positioning disk center hole 9 is arranged at the center of the positioning disk 4. A second limiting groove 91 and a third limiting groove 92 are arranged on one side of the positioning disk center hole 9. The angles of the second limiting groove 91 and the third limiting groove 92 on the circumference of the positioning disk 4 differ by 36°. Limiting blocks that are in clamping fit with the respective limiting grooves are arranged at the bottom and top of the central shaft 5. During assembly, the bottom end of the central shaft 5 is placed in the chassis center hole 35, the limiting block at the bottom of the central shaft is placed in the first limiting groove 36, and the limiting block at the top of the central shaft 5 is placed in the second limiting groove 91 or the third limiting groove 92 so that the positioning disk 4 and the chassis 3 are coaxially arranged, avoiding relative rotation between the positioning disk 4 and the chassis 3 during assembly, which may affect the alignment of the inlet pipe 24 of the pre-evaporation pipe 2 with the welding hole.

[0042] The outer diameter of the positioning disk 4 is the same as the outer diameter of the annular inner side wall 11 of the combustion chamber flame tube. An annular step portion 48 is arranged along the edge at the bottom end of the positioning disk 4 so that when the positioning disk 4 is placed above the combustion chamber flame tube, the annular step portion 48 of the positioning disk is supported by the annular inner side wall 11 of the combustion chamber flame tube.

[0043] Embodiment 2

[0044] The usage method of the above-mentioned combustion chamber flame tube pre-evaporation pipe installation fixture includes the following steps:

[0045] A. Put the chassis 3 on the central shaft 5 so that the limiting block at the bottom of the central shaft 5 is placed in the first limiting groove 36; place the combustion chamber flame tube on the chassis 3 so that the welding hole on the arc-shaped bottom wall 13 is placed in the hollow portion 32 between two adjacent receiving teeth 31; fix the combustion chamber flame tube and the chassis 3 through the positioning bolt 34.

[0046] B. Assemble the corresponding square shaft 7, slider 41, positioning bracket 6 and positioning disc 5, and support the first group of 5 pre-evaporation tubes 2 by the positioning bracket 6 respectively. Adjust the setscrew 8 so that the arc-shaped clamp 81 limits and fixes the pre-evaporation tube 2.

[0047] C. Put the positioning disc 4 on the upper part of the central shaft 5, so that the square shaft 7, positioning bracket 6 and setscrew 8 are inserted into the annular cavity 14 as a whole. The second limiting groove 91 is engaged with the limiting block on the upper part of the central shaft 5 to complete the insertion and matching of the first group of 5 pre-evaporation tubes 2 with the welding holes.

[0048] D. Weld and fix the inlet tubes 21 inserted into the welding holes one by one in the hollow part 32 to complete the assembly of the first group of 5 non-adjacent pre-evaporation tubes 2.

[0049] E. After the welding of the first group of 5 pre-evaporation tubes 2 is completed, use tweezers to pull out the insertion pin 66 so that the square shaft 7 and the positioning bracket 6 can be separated. Disengage the positioning disc 4 from the central shaft 5, so that the setscrew 8 and the square shaft 7 are withdrawn from the annular cavity 14, and then take out the positioning bracket 6 in the annular cavity 14.

[0050] F. Assemble the square shaft 7, slider 41, positioning bracket 6 and positioning disc 5 again, and support the second group of 5 pre-evaporation tubes 2 by the positioning bracket 6 respectively. Adjust the setscrew 8 so that the arc-shaped clamp 81 limits and fixes the pre-evaporation tube 2 again.

[0051] G. Put the positioning disc 4 on the upper part of the central shaft 5, so that the square shaft 7, positioning bracket 6 and setscrew 8 are inserted into the annular cavity 14 as a whole. The third limiting groove 92 is engaged with the limiting block on the upper part of the central shaft 5 to complete the insertion and matching of the second group of 5 pre-evaporation tubes 2 with the welding holes.

[0052] H. Weld and fix the inlet tubes 21 inserted into the welding holes one by one in the hollow part 32 to complete the assembly of the second group of 5 pre-evaporation tubes 2.

[0053] I. After the welding of the second group of 5 pre-evaporation tubes 2 is completed, use tweezers to pull out the insertion pin 66 so that the square shaft 7 and the positioning bracket 6 can be separated. Disengage the positioning disc 4 from the central shaft 5, so that the setscrew 8 and the square shaft 7 are withdrawn from the annular cavity 14, and then take out the positioning bracket 6 in the annular cavity 14, and separate the chassis 3 and the combustion chamber flame tube to complete the assembly of all 10 pre-evaporation tubes 2.

[0054] When designing the above fixture, according to the distribution positions of the welding holes and the dimensions of the annular inner side wall 11, the arc-shaped bottom wall 13, and the annular outer side wall 12, the dimensions of the chassis, the receiving teeth, the first limiting groove, the positioning disc, the second limiting groove, the third limiting groove, the slider, the square shaft, and the setscrew are set. Through two assemblies of the positioning disc, the assembly of 10 pre-evaporation tubes is completed in two groups, making the space in the annular cavity relatively large during assembly and reducing the assembly difficulty.

[0055] Obviously, the above embodiments are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And these obvious changes or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. A pre-evaporation tube installation fixture for a combustion chamber flame tube, characterized in that, it includes a chassis, a positioning disk, a positioning bracket, a square shaft and a setscrew. Ten receiving teeth are provided on the edge of the chassis protruding radially outward. The receiving teeth are evenly distributed on the edge of the chassis, and a hollow part is formed between adjacent receiving teeth. When the combustion chamber flame tube is coaxially arranged on the chassis, the arc-shaped bottom wall of the combustion chamber flame tube contacts the chassis, and each welding hole on the arc-shaped bottom wall is respectively placed in the hollow part between adjacent receiving teeth. Five sliders are evenly distributed on the edge of the positioning disk, and each slider protrudes radially outward along the edge of the positioning disk. A square shaft and a liftable setscrew are arranged along the axial direction of the positioning disk on each slider. The bottom end of the square shaft is connected to the positioning bracket. The positioning bracket includes a connecting part, and support parts are respectively arranged at both ends on one side of the connecting part, and a hollow area is formed between the two support parts. During clamping, five pre-evaporation tubes are placed on corresponding positioning brackets. The first outlet tube and the second outlet tube of each pre-evaporation tube are respectively placed on the two support parts, and the inlet tube passes through the hollow area. The bottom end of the setscrew passes through the slider and is placed above the connecting pipe of the pre-evaporation tube, so that the pre-evaporation tube can be clamped after the setscrew descends. Then the positioning disk is coaxially arranged above the combustion chamber flame tube, the setscrew, the square shaft, the positioning bracket and the pre-evaporation tube are inserted into the annular cavity of the combustion chamber flame tube, the inlet tube of the pre-evaporation tube is inserted into the welding hole at the bottom of the combustion chamber flame tube, and the welding hole and the inlet tube are welded and fixed at the corresponding hollow part of the chassis. It further includes a central shaft. A chassis central hole is provided at the center of the chassis, and a positioning disk central hole is provided at the center of the positioning disk. During assembly, the bottom end of the central shaft is placed in the chassis central hole, and the positioning disk is connected to the central shaft through the positioning disk central hole, so that the positioning disk and the chassis are coaxially arranged. A first limiting groove is provided on one side of the chassis central hole, a second limiting groove and a third limiting groove are provided on one side of the positioning disk central hole, and limiting blocks for clamping and cooperating with each limiting groove are respectively provided at the bottom and top of the central shaft.

2. The pre-evaporation tube installation fixture for a combustion chamber flame tube according to claim 1, characterized in that, the angle difference between the second limiting groove and the third limiting groove on the circumference of the positioning disk is 36°.

3. The pre-evaporation tube installation fixture for a combustion chamber flame tube according to claim 2, characterized in that, the square shaft includes a square shaft body in the shape of a cuboid. A first square hole is provided through the slider, and a second square hole is provided in the connecting part of the positioning bracket. During assembly, the upper part of the square shaft body is inserted into the first square hole, and the lower part of the square shaft body is inserted into the second square hole.

4. The pre-evaporation tube installation fixture for a combustion chamber flame tube according to claim 3, characterized in that, a plugging hole perpendicular to the second square hole is further provided in the connecting part of the positioning bracket. The plugging hole passes through the second square hole. An installation hole adapted to the plugging hole is provided at the lower part of the square shaft body. When the lower part of the square shaft body is placed in the second square hole, the installation hole and the plugging hole are aligned, and a plugging pin is inserted into the installation hole and the plugging hole to limit and fix the square shaft and the positioning bracket.

5. The installation fixture for the pre-evaporation tube of the combustion chamber flame tube according to any one of claims 1 to 4, characterized in that, it further includes an arc-shaped clamp. The arc-shaped part at the front end of the clamp is adapted to the shape of the communication pipe of the pre-evaporation tube. An elastic spherical hole is provided at the tail end of the arc-shaped clamp. A ball is fixedly arranged at the bottom end of the set screw. During assembly, the ball is squeezed into the spherical hole so that the set screw is connected to the arc-shaped clamp, and the arc-shaped clamp can rotate around the ball.

6. The installation fixture for the pre-evaporation tube of the combustion chamber flame tube according to claim 5, characterized in that, a concave area adapted to the shapes of the pipe ends of the first outlet pipe and the second outlet pipe of the pre-evaporation tube is provided on the upper end surface of the positioning bracket support part.

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