A vacuum brazing method for a nozzle housing assembly

Abstract

The present invention discloses a vacuum brazing method for a nozzle housing assembly, comprising: loading a liner assembly into the inner hole of the nozzle housing; placing a first filler metal ring at the brazing seam to be welded between the liner assembly and the nozzle housing, fixing the liner assembly and the nozzle housing by using a process tab, and performing vacuum brazing to obtain a first assembly; inserting the end to be welded of the auxiliary oil pipe into the inclined cylindrical hole of the nozzle housing, and adjusting the length of the exposed end of the auxiliary oil pipe to the designed value; fixing the exposed end of the auxiliary oil pipe to the nozzle housing; placing a second filler metal ring at the brazing seam to be welded between the auxiliary oil pipe and the nozzle housing, and performing vacuum brazing to obtain the nozzle housing assembly; through a reasonable part welding sequence, the present invention performs vacuum brazing in stages to meet the requirements of the positional accuracy of part assembly; the liner assembly and the nozzle housing are fixed by using a process tab, and the exposed end of the auxiliary oil pipe is fixed to the nozzle housing, effectively ensuring the precise control of the positional accuracy among the liner assembly, the nozzle housing and the auxiliary oil pipe.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding, and particularly relates to a vacuum brazing method for a nozzle housing assembly. Background Art

[0002] As shown in the Figure 1-2 attached figure, a fuel nozzle housing assembly of a certain aeroengine includes a bushing assembly 3, a nozzle housing 4, and a sub-oil pipe 7; a countersunk hole is provided on the bushing assembly 3 for the sub-oil pipe 7 to penetrate and insert; the bushing assembly 3 includes a bushing 1 and a bushing seat 2 connected coaxially; one end of the nozzle housing 4 is provided with an inner hole, and the other end is provided with an inclined cylindrical hole; the bushing assembly 3 is assembled in the inner hole of the nozzle housing 4, one end of the sub-oil pipe 7 is inserted into the inclined cylindrical hole of the nozzle housing 4, and the other end of the sub-oil pipe 7 extends to the outside of the nozzle housing 4.

[0003] The nozzle housing assembly has the characteristics of complex and precise structure, many and concentrated weld seams, strict welding quality control, and high position tolerance requirements; since the weld seams to be welded of multiple single parts in the above nozzle housing assembly are densely distributed, and it is necessary to ensure the welding quality and assembly position tolerance requirements at the same time, while the conventional welding process and operation method cannot meet its structural design and processing requirements; therefore, it is urgent to design a welding method for the above nozzle housing assembly. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a vacuum brazing method for a nozzle housing assembly to solve the technical problems that the conventional welding process and operation method cannot meet the structural design and processing requirements of the nozzle housing assembly.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a vacuum brazing method for a nozzle housing assembly, including the following steps:

[0007] Step 1: Install the bushing assembly into the inner hole of the nozzle housing; place a first filler metal ring at the brazing seam to be welded between the bushing assembly and the nozzle housing, and fix the bushing assembly and the nozzle housing with a process tab to obtain the first part to be welded;

[0008] Step 2: Perform vacuum brazing on the first part to be welded to obtain the first assembly;

[0009] Step 3: Insert the end to be welded of the sub-oil pipe into the inclined cylindrical hole of the nozzle housing in the first assembly, and adjust the length of the exposed end of the sub-oil pipe to the designed value; then, fix the exposed end of the sub-oil pipe with the nozzle housing; then, place a second filler metal ring at the brazing seam to be welded between the sub-oil pipe and the nozzle housing to obtain the second part to be welded;

[0010] Step 4: Perform vacuum brazing on the second part to be welded to obtain the nozzle housing assembly.

[0011] Furthermore, in Step 1, the bushing assembly includes a coaxially connected bushing and a bushing seat; the bushing and the bushing seat are connected by vacuum brazing.

[0012] Furthermore, the process of connecting the bushing and the bushing seat by vacuum brazing is as follows:

[0013] Based on the burr positioning method, assemble and position the bushing and the bushing seat together; then, place the pre-wound filamentous filler metal ring at the brazing joint to be welded between the bushing and the bushing seat; then, after performing vacuum brazing, obtain the bushing assembly.

[0014] Furthermore, in Step 1, during the process of inserting the bushing assembly into the inner hole of the nozzle housing, insert the mandrel through the bushing assembly along the inclined cylindrical hole of the nozzle housing and then insert it to the bottom of the inner hole of the nozzle housing to position the bushing assembly; wherein, the mandrel is taken out after fixing the bushing assembly and the nozzle housing by using the process tabs.

[0015] Furthermore, in Step 1, the process of placing the first filler metal ring at the brazing joint to be welded between the bushing assembly and the nozzle housing and fixing the bushing assembly and the nozzle housing by using the process tabs to obtain the first part to be welded is as follows:

[0016] Place the first filler metal ring at the brazing joint to be welded between the bushing assembly and the nozzle housing; wherein, the first filler metal ring is placed close to the brazing joint to be welded between the bushing assembly and the nozzle housing.

[0017] Set a plurality of process tabs evenly along the circumferential direction of the inner hole of the bushing assembly and the inner hole of the nozzle housing between the bushing assembly and the nozzle housing; wherein, adopt the energy storage spot welding method to spot-weld the two ends of the process tab to the bushing assembly and the nozzle housing respectively.

[0018] Furthermore, the distance between the process tab and the first filler metal ring is greater than or equal to 1 mm, and a flow blocker is applied to the middle part of the process tab.

[0019] Furthermore, in Step 3, use a welding fixture to fix the exposed end of the auxiliary oil pipe and the nozzle housing.

[0020] Among them, the welding fixture includes a hollow cylindrical tube and a fixed ring plate, and the fixed ring plate is arranged at the first end of the hollow cylindrical tube; among them, one side of the fixed ring plate is in close contact with the end of the nozzle housing, and the other side of the fixed ring plate is connected to the first end of the hollow cylindrical tube;

[0021] The exposed end of the auxiliary oil pipe passes through the fixed ring plate and the hollow cylindrical tube in sequence, and the end of the exposed end of the auxiliary oil pipe is flush with the second end of the hollow cylindrical tube; alloy shims are fixedly connected between the outer circumferential surface of the fixed ring plate and the outer circumferential surface of the end of the nozzle housing and between the end of the exposed end of the auxiliary oil pipe and the second end of the hollow cylindrical tube.

[0022] Further, the alloy shims are connected to the fixed ring plate, the hollow cylindrical tube and the auxiliary oil pipe by energy storage spot welding.

[0023] Further, the second solder ring is arranged at the intersection line position between the auxiliary oil pipe and the nozzle housing; a solder compensation section is arranged in the semi-circular wedge-shaped space between the second solder ring and the inner wall of the inclined cylindrical hole of the nozzle housing.

[0024] Further, after step 4, it also includes the step of repairing the brazed seam at the auxiliary oil pipe;

[0025] Among them, the step of repairing the brazed seam at the auxiliary oil pipe is specifically as follows:

[0026] Conduct a weld quality inspection on the nozzle housing assembly in step 4. If there are defects in the brazed seam position of the auxiliary oil pipe, insert a pencil lead into the inner hole of the auxiliary oil pipe; then put a third solder ring on the pencil lead and apply an adhesive on the third solder ring; finally, perform vacuum brazing to obtain the repaired nozzle housing assembly.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The present invention provides a vacuum brazing method for a nozzle housing assembly. After positioning and vacuum brazing the liner assembly and the nozzle housing, the auxiliary oil pipe is assembled and vacuum brazed to the nozzle housing. Through a reasonable part welding sequence, vacuum brazing is carried out in stages, while ensuring the welding quality of the parts, meeting the requirements of the assembly position accuracy of the parts; among them, the liner assembly and the nozzle housing are fixed by using process shims, and the exposed end of the auxiliary oil pipe is fixed to the nozzle housing, effectively ensuring the precise control of the position accuracy among the liner assembly, the nozzle housing and the auxiliary oil pipe; the vacuum brazing method of the nozzle assembly can play an important engineering application reference value for the processing and manufacturing of the same type of parts.

[0029] Further, the mandrel is inserted through the liner assembly along the inclined cylindrical hole of the nozzle housing and into the bottom of the inner hole of the nozzle housing, achieving precise positioning of the liner assembly, and thus meeting the assembly position requirements of the subsequent sub-oil pipe in the nozzle housing.

[0030] Further, a welding fixture is used to fix between the exposed end of the sub-oil pipe and the nozzle housing, and the welding fixture is fixed to the sub-oil pipe and the nozzle housing by energy storage spot welding, ensuring the length of the sub-oil pipe protruding from the nozzle housing and ensuring the assembly accuracy of the sub-oil pipe.

[0031] Further, the solder compensation section is used to compensate the semi-ring wedge-shaped space between the second solder ring and the inner wall of the inclined cylindrical hole of the nozzle housing, effectively improving the vacuum brazing quality of the sub-oil pipe and the nozzle housing.

[0032] Further, when repairing the brazing seam at the sub-oil pipe after drilling and reaming the end and then welding, a graphite material pencil core is inserted into the sub-oil pipe. On the one hand, it acts as a support for placing the solder ring, and on the other hand, graphite can prevent the solder from flowing into the inner hole of the sub-oil pipe, thus realizing the repair welding of the parts and reducing the production cost. Description of the Drawings

[0033] Figure 1 is a schematic structural diagram of the nozzle housing assembly in the present invention;

[0034] Figure 2 is a schematic structural diagram of the liner assembly in the present invention;

[0035] Figure 3 is a flowchart of the vacuum brazing method for the nozzle housing assembly described in the embodiment;

[0036] Figure 4 is a schematic assembly structure diagram of the liner assembly and the nozzle housing in the embodiment;

[0037] Figure 5 is Figure 4 a partial enlarged schematic diagram at A in

[0038] Figure 6 is a schematic assembly structure diagram of the sub-oil pipe and the welding fixture in the embodiment;

[0039] Figure 7 is a schematic diagram of the solder placed at the sub-oil pipe in the embodiment;

[0040] Figure 8 is a schematic diagram of the operation for repairing the brazing seam at the sub-oil pipe in the embodiment.

[0041] Among them, 1 bushing, 2 bushing seat, 3 bushing cylinder assembly, 4 nozzle housing, 5 process tab, 6 first solder ring, 7 sub-oil pipe, 8 alloy tab, 9 welding fixture, 10 pencil lead, 11 second solder ring, 12 solder replenishment section, 13 third solder ring, 14 mandrel. Specific implementation mode

[0042] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clear and understandable, the following specific embodiments are used to further elaborate on the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] The present invention provides a vacuum brazing method for a nozzle housing assembly, including the following steps:

[0044] Step 1: Based on the burr positioning method, assemble and position the bushing 1 and the bushing seat 2 together; then, place the pre-wound filamentous solder ring at the brazing seam to be welded between the bushing 1 and the bushing seat 2; then, perform vacuum brazing to obtain the bushing cylinder assembly 3.

[0045] Step 2: Install the bushing cylinder assembly 3 into the inner hole of the nozzle housing 4; place the first solder ring 6 at the brazing seam to be welded between the bushing cylinder assembly 3 and the nozzle housing 4, and use the process tab 5 to fix the bushing cylinder assembly 3 and the nozzle housing 4 to obtain the first part to be welded.

[0046] In step 2 of the present invention, during the process of installing the bushing cylinder assembly 3 into the inner hole of the nozzle housing 4, the mandrel 14 is used to position the bushing cylinder assembly 3; specifically, the mandrel 14 is inserted into the bottom of the inner hole of the nozzle housing 4 through the bushing cylinder assembly 3 along the inclined cylindrical hole of the nozzle housing 4 to achieve the positioning of the bushing cylinder assembly 3; it should be noted that the insertion position of the mandrel 14 is the same as the installation position of the sub-oil pipe 7; the mandrel 14 is taken out after using the process tab 5 to fix the bushing cylinder assembly 3 and the nozzle housing 4.

[0047] In step 2 of the present invention, the process of placing the first solder ring 6 at the brazing seam to be welded between the bushing cylinder assembly 3 and the nozzle housing 4 and using the process tab 5 to fix the bushing cylinder assembly 3 and the nozzle housing 4 to obtain the first part to be welded is as follows:

[0048] Place the first solder ring 6 at the brazing seam to be welded between the bushing cylinder assembly 3 and the nozzle housing 4; among them, the first solder ring 6 is placed close to the brazing seam to be welded between the bushing cylinder assembly 3 and the nozzle housing 4.

[0049] A number of process tabs 5 are evenly arranged between the bushing assembly 3 and the nozzle housing 4 along the circumferential direction of the inner hole of the bushing assembly 3 and the inner hole of the nozzle housing 4. Among them, both ends of the process tab 5 are spot-welded to the bushing assembly 3 and the nozzle housing 4 respectively by using energy storage spot welding. Preferably, the distance between the process tab 5 and the first filler metal ring 6 is greater than or equal to 1 mm, and a flow blocker is applied to the middle part of the process tab 5.

[0050] Step 3: Perform vacuum brazing on the first part to be welded to obtain the first assembly.

[0051] Step 4: Insert the welding end of the auxiliary oil pipe 7 into the inclined cylindrical hole of the nozzle housing 4 in the first assembly, and adjust the length of the exposed end of the auxiliary oil pipe 7 to the designed value. Then, fix the exposed end of the auxiliary oil pipe 7 to the nozzle housing 4. Next, place the second filler metal ring 11 at the brazing seam to be welded of the auxiliary oil pipe 7 to obtain the second part to be welded.

[0052] In step 4 of the present invention, a welding fixture 9 is used to fix the exposed end of the auxiliary oil pipe 7 to the nozzle housing 4. Among them, the welding fixture 9 includes a hollow cylindrical tube and a fixing ring plate, and the fixing ring plate is arranged at the first end of the hollow cylindrical tube. One side of the fixing ring plate is in close contact with the end of the nozzle housing 4, and the other side of the fixing ring plate is fixedly connected to the first end of the hollow cylindrical tube. The exposed end of the auxiliary oil pipe 7 passes through the fixing ring plate and the hollow cylindrical tube in sequence, and the end of the exposed end of the auxiliary oil pipe 7 is flush with the second end of the hollow cylindrical tube. That is, the length of the hollow cylinder is matched with the length of the exposed end of the auxiliary oil pipe 7. The outer circumferential surface of the fixing ring plate and the outer circumferential surface of the end of the nozzle housing 4, and between the end of the exposed end of the auxiliary oil pipe 7 and the second end of the hollow cylindrical tube are fixedly connected by alloy tabs 8. Among them, the alloy tabs 8 are connected to the fixing ring plate, the hollow cylindrical tube and the auxiliary oil pipe 7 by energy storage spot welding.

[0053] In step 4 of the present invention, the second filler metal ring 11 is arranged at the intersection line position between the auxiliary oil pipe 7 and the nozzle housing 4. A filler metal compensation section 12 is arranged in the semi-circular wedge-shaped space between the second filler metal ring 11 and the inner wall of the inclined cylindrical hole of the nozzle housing 4. The semi-circular wedge-shaped space between the second filler metal ring 11 and the inner wall of the inclined cylindrical hole of the nozzle housing 4 is compensated by using the filler metal compensation section 12, effectively improving the vacuum brazing quality of the auxiliary oil pipe 7 and the nozzle housing 4.

[0054] Step 5: Perform vacuum brazing on the second part to be welded to obtain the nozzle housing assembly.

[0055] Step 6: Inspect the weld quality of the nozzle housing assembly in Step 5. If there are defects at the brazed joint position of the auxiliary oil pipe 7, insert a pencil lead 10 into the inner hole of the auxiliary oil pipe 7; then, fit a third brazing filler metal ring 13 over the pencil lead 10 and apply an adhesive to the third brazing filler metal ring 13; finally, perform vacuum brazing to obtain the nozzle housing assembly after repair welding.

[0056] For the vacuum brazing method of the nozzle housing assembly of the present invention, after positioning and vacuum brazing the liner assembly 3 and the nozzle housing 4, the auxiliary oil pipe 7 is assembled and vacuum brazed to the nozzle housing 4. Through a reasonable part welding sequence, vacuum brazing is carried out in stages, which can ensure the welding quality of the parts while meeting the requirements of the assembly position accuracy of the parts. Among them, the liner assembly 3 and the nozzle housing 4 are fixed by using a mandrel and a process tab 5, and the exposed end of the auxiliary oil pipe 7 is fixed to the nozzle housing 4, effectively ensuring the precise control of the position accuracy among the liner assembly 3, the nozzle housing 4, and the auxiliary oil pipe 7. The vacuum brazing method of the nozzle housing assembly can play an important reference value for the processing and manufacturing of the same type of parts in engineering applications.

[0057] Embodiment

[0058] The processing process of the nozzle housing assembly of a certain type of aeroengine is described below.

[0059] As shown in the Figure 1 accompanying drawings, the nozzle housing assembly includes a liner assembly 3, a nozzle housing 4, and an auxiliary oil pipe 7. A countersunk hole is provided on the liner assembly 3 for the auxiliary oil pipe 7 to penetrate and insert. The liner assembly 3 includes a bushing 1 and a socket 2 connected coaxially, and the bushing 1 and the socket 2 are connected by vacuum brazing. One end of the nozzle housing 4 is provided with an inner hole, and the other end is provided with an inclined cylindrical hole. The liner assembly 3 is assembled in the inner hole of the nozzle housing 4, one end of the auxiliary oil pipe 7 is inserted into the inclined cylindrical hole of the nozzle housing 4, and the other end of the auxiliary oil pipe 7 extends to the outside of the nozzle housing 4.

[0060] As shown in the Figure 2 accompanying drawings, this embodiment provides a vacuum brazing method for a nozzle housing assembly, including the following steps:

[0061] Step 1: Vacuum braze the liner assembly

[0062] As shown in the Figure 3 accompanying drawings, based on the burr positioning method, the bushing 1 and the socket 2 are assembled and positioned together; the pre-wound filamentous brazing filler metal ring is placed at the brazed joint to be welded between the bushing 1 and the socket 2, and then furnace vacuum brazing is carried out to obtain the liner assembly 3. Among them, the pre-wound filamentous brazing filler metal ring is a filamentous HBAu82Ni brazing filler metal ring; the vacuum brazing temperature is 1060 °C, and the holding time is 20 min.

[0063] Step 2: Assemble the positioning bushing assembly on the nozzle housing

[0064] As shown in the appendix Figure 4-5 As shown, in step 21: Insert the bushing assembly 3 into the inner hole of the nozzle housing 4; specifically, insert the bushing assembly 3 after drilling and countersinking into the inner hole of the nozzle housing 4, and then insert the mandrel 14 through the bushing assembly 3 along the inclined cylindrical hole of the nozzle housing 4 and into the bottom of the inner hole of the nozzle housing 4 to position the bushing assembly 3 and ensure the positional tolerance requirements between the bushing assembly 3 and the nozzle housing 4; wherein, the mandrel 14 is taken out after fixing the bushing assembly 3 and the nozzle housing 4 by using the process tab 5.

[0065] Step 22: Place the first filler metal ring 6 at the brazing seam to be welded between the bushing assembly 3 and the nozzle housing 4; specifically, place the first filler metal ring 6 in close contact with the brazing seam to be welded between the bushing assembly 3 and the nozzle housing 4.

[0066] Step 23: Fix the bushing assembly 3 and the nozzle housing 4 by using the process tab 5 to obtain the first part to be welded; specifically, a number of process tabs 5 are evenly arranged between the bushing assembly 3 and the nozzle housing 4 along the circumferences of the inner holes of the bushing assembly 3 and the nozzle housing 4; adopt the energy storage spot welding method to spot-weld the two ends of the process tab 5 to the bushing assembly 3 and the nozzle housing 4 respectively; wherein, the distance d between the process tab 5 and the first filler metal ring 6 is greater than or equal to 1 mm; a flow blocker is applied to the middle part of the process tab 5, and the edge of the applied flow blocker is 4 mm away from the end of the process tab 5; preferably, the number of the process tabs 5 is three, and the three process tabs 5 are evenly arranged along the circumference; that is, the bushing assembly 3 and the nozzle housing 4 are connected by the method of evenly arranging and spot-welding three process tabs 5 along the circumference; wherein, the energy of the energy storage spot welding is 60 J, and two spots are welded on each process tab 5; preferably, the first filler metal ring 6 is a filamentous HBAu82Ni filler metal ring.

[0067] Step 3: Vacuum brazing the bushing assembly and the nozzle housing

[0068] Vacuum braze the first part to be welded to obtain the first assembly; wherein, the brazing temperature is 1020 °C and the holding time is 20 min.

[0069] Step 4: Assemble the positioning auxiliary oil pipe

[0070] Insert the welding end of the auxiliary oil pipe 7 into the inclined cylindrical hole of the nozzle housing 4 in the first component, and adjust the length of the exposed end of the auxiliary oil pipe 7 to the designed value; then, use a welding fixture 9 to fix the exposed end of the auxiliary oil pipe 7 to the nozzle housing 4.

[0071] As shown in the Figure 6 accompanying drawings, the welding fixture 9 includes a hollow cylindrical tube and a fixing ring plate, and the fixing ring plate is arranged at the first end of the hollow cylindrical tube; one side of the fixing ring plate is in close contact with the end of the nozzle housing 4, and the other side of the fixing ring plate is connected to the first end of the hollow cylindrical tube; preferably, the hollow cylindrical tube and the fixing ring plate are integrally formed; the exposed end of the auxiliary oil pipe 7 passes through the fixing ring plate and the hollow cylindrical tube in sequence, and the end of the exposed end of the auxiliary oil pipe 7 is flush with the second end of the hollow cylindrical tube; both between the outer circumferential surface of the fixing ring plate and the outer circumferential surface of the end of the nozzle housing 4 and between the end of the exposed end of the auxiliary oil pipe 7 and the second end of the hollow cylindrical tube are fixedly connected by alloy shims 8; wherein, the alloy shims 8 are connected to the fixing ring plate, the hollow cylindrical tube and the auxiliary oil pipe 7 by energy storage spot welding; preferably, the energy of the energy storage spot welding is 60J; in this embodiment, by using the welding fixture 9 and adopting the method of energy storage spot welding the alloy shims 8 to position and fix the auxiliary oil pipe, the length of the exposed end of the auxiliary oil pipe extending out of the nozzle housing can be guaranteed.

[0072] Step 5: Place filler metal at the auxiliary oil pipe

[0073] As shown in the Figure 7 accompanying drawings, place a second filler metal ring 11 at the brazing seam to be welded of the auxiliary oil pipe 7 in step 4, and arrange a filler metal compensation section 12 in the semi-circular wedge-shaped space between the second filler metal ring 11 and the inner wall of the inclined cylindrical hole of the nozzle housing 4, and use the filler metal compensation section 12 to compensate the semi-circular wedge-shaped space between the second filler metal ring 11 and the inner wall of the inclined cylindrical hole of the nozzle housing 4; finally, apply an adhesive to the second filler metal ring 11 and the filler metal compensation section 12 to prevent the second filler metal ring 11 and the filler metal compensation section 12 from falling off, and obtain the second part to be welded.

[0074] Among them, the second filler metal ring 11 is arranged at the intersection line position between the auxiliary oil pipe 7 and the nozzle housing 4; specifically, use tweezers to hold the second filler metal ring 11 and insert it into the small hole of the nozzle housing and fit it around the welding place of the auxiliary oil pipe 7; among them, the second filler metal ring 11 is a filamentous HBAu82Ni filler metal ring, and the filler metal compensation section 12 is a filamentous HBAu82Ni filler metal section; preferably, the filler metal compensation section 12 is positioned by energy storage electric welding, and the energy of the energy storage spot welding is 40J.

[0075] Step 6: Vacuum brazing the nozzle housing and the auxiliary oil pipe

[0076] Perform vacuum brazing on the second part to be welded to obtain the nozzle housing assembly; specifically, place the second part to be welded equipped with a welding fixture stably in a basket and put it into the furnace for welding to obtain the nozzle housing assembly; preferably, the brazing temperature is 1000 °C and the heat preservation time is 15 - 20 min.

[0077] Step 7: Repair the brazing seam at the auxiliary oil pipe

[0078] As shown in the Figure 8 figure, perform weld quality inspection on the nozzle housing assembly in Step 6. If there are defects in the brazing seam position of the auxiliary oil pipe 7, insert a pencil lead 10 into the inner hole of the auxiliary oil pipe 7; then put a third filler metal ring 13 on the pencil lead 10 and apply an adhesive on the third filler metal ring 13; finally, perform vacuum brazing to obtain the repaired nozzle housing assembly.

[0079] Specifically, after vacuum brazing the nozzle housing 4 and the auxiliary oil pipe 7, use the method of drilling and reaming to remove the preset weld depth; then check the weld quality through a sealing test or an airtightness test; if there are defects in the brazing seam position of the auxiliary oil pipe 7, the defective weld position should be repaired by welding. After repair, repeat the sealing test or the airtightness test for detection until the parts are qualified; among them, the repair process is as follows:

[0080] Insert a pencil lead 10 into the inner hole of the auxiliary oil pipe 7 after drilling and reaming the end, then use tweezers to hold the pre-wound third filler metal ring 13 and extend it into the nozzle housing 4 through the small hole to put it on the pencil lead 10, and apply a small amount of adhesive on the third filler metal ring 13, and finally put it into the furnace for vacuum brazing; among them, the third filler metal ring 13 uses a filamentous HBAu82Ni filler metal ring; the vacuum temperature is 1000 °C and the heat preservation time is 15 min.

[0081] Processing principle:

[0082] The vacuum brazing method of the nozzle housing assembly described in the present invention, in terms of position control, for the sub-oil pipe welded to the nozzle housing, one end thereof needs to pass through the liner assembly 3 and insert into the inclined cylindrical hole of the nozzle housing, while the other end of the sub-oil pipe needs to control the length extending out of the nozzle housing; in the present invention, the liner assembly and the nozzle housing are fixed by using process tabs, and the exposed end of the sub-oil pipe is fixed to the nozzle housing, effectively ensuring the precise control of the position among the liner assembly, the nozzle housing and the sub-oil pipe; the mandrel is inserted into the bottom of the inner hole of the nozzle housing through the inclined cylindrical hole of the nozzle housing after passing through the liner assembly, realizing the precise positioning of the liner assembly, and further meeting the assembly position requirements of the subsequent sub-oil pipe in the nozzle housing; the exposed end of the sub-oil pipe and the nozzle housing are fixed by using a welding fixture, and the welding fixture is fixed to the sub-oil pipe and the nozzle housing by using energy storage spot welding, ensuring the length of the sub-oil pipe extending out of the nozzle housing and ensuring the assembly accuracy of the sub-oil pipe.

[0083] In terms of welding quality control, taking the brazing seam to be welded between the nozzle housing and the sub-oil pipe as an example, from the perspective of pure welding quality, the position where brazing is implemented is the intersection line generated by two cylinders that are inclined to each other and have different diameters, that is, the space available for filler metal to fill at the brazing seam to be welded is an inclined circular cylinder; after welding, it is necessary to drill and ream holes to remove the preset weld depth, and then check the weld quality through a seal test or an airtight test; to save costs, the defective weld position will be repaired by welding, and after repair welding, the seal test or the airtight test will be continued until the part inspection is qualified.

[0084] The nozzle housing assembly in the present invention has the characteristics of complex and precise structure, a large number of welds and concentration. In the vacuum brazing method of the nozzle housing assembly, by reasonably arranging the welding sequence of each supporting part and specifically designing the welding parameters in stages; specifically, when assembling and positioning the liner assembly in the nozzle housing, the method of inserting a mandrel through the liner assembly and positioning with an energy storage spot welding process tab is adopted to meet the assembly position requirements of the subsequent sub-oil pipe in the nozzle housing; when assembling and positioning the sub-oil pipe in the nozzle housing, the sub-oil pipe is fixed by using a welding fixture and combining the positioning method of an energy storage spot welding tab, while ensuring the length of its exposed end extending out of the nozzle housing; when placing filler metal at the sub-oil pipe, the filamentous filler metal section is positioned by using energy storage spot welding in the semi-circular wedge-shaped space between the filler metal ring and the hole wall of the housing, compensating for the filler metal lacking due to structural reasons, and further improving the welding quality; when repairing the brazing seam at the sub-oil pipe after drilling and reaming the end, a graphite material pencil core is inserted into the sub-oil pipe. On the one hand, it acts as a support for placing the filler metal ring, and on the other hand, graphite can prevent the filler metal from flowing into the inner hole of the sub-oil pipe, thus realizing the repair welding of the part and reducing the production cost; while ensuring the welding quality of the part, the present invention meets the position requirements of the part assembly, and has important engineering application reference value for the processing and manufacturing of similar parts.

[0085] The above embodiments are only one of the implementation manners capable of implementing the technical solution of the present invention. The scope of protection required by the present invention is not limited to this embodiment only, but also includes any changes, substitutions and other implementation manners that are easily conceivable by any person skilled in the art within the technical scope disclosed by the present invention.

Claims

1. A vacuum brazing method for a nozzle housing assembly, characterized in that, It includes the following steps: Step 1: Install the bushing assembly (3) into the inner hole of the nozzle housing (4); place the first filler metal ring (6) at the brazing seam to be welded between the bushing assembly (3) and the nozzle housing (4), and fix the bushing assembly (3) and the nozzle housing (4) using the process tabs (5) to obtain the first part to be welded; Step 2: Perform vacuum brazing on the first part to be welded to obtain Assembly 1; Step 3: Insert the end to be welded of the auxiliary oil pipe (7) into the inclined cylindrical hole of the nozzle housing (4) in Assembly 1, and adjust the length of the exposed end of the auxiliary oil pipe (7) to the designed value; then, fix the exposed end of the auxiliary oil pipe (7) to the nozzle housing (4); next, place the second filler metal ring (11) at the brazing seam to be welded between the auxiliary oil pipe (7) and the nozzle housing (4) to obtain the second part to be welded; Step 4: Perform vacuum brazing on the second part to be welded to obtain the nozzle housing assembly; In Step 1, the bushing assembly (3) includes a bushing (1) and a bushing seat (2) connected coaxially; the bushing (1) and the bushing seat (2) are connected by vacuum brazing.

2. The vacuum brazing method of a nozzle housing assembly according to claim 1, characterized in that, The process of connecting the bushing (1) and the bushing seat (2) by vacuum brazing is as follows: Based on the burr positioning method, assemble and position the bushing (1) and the bushing seat (2) together; then, place the pre-wound filamentous filler metal ring at the brazing seam to be welded between the bushing (1) and the bushing seat (2); next, after performing vacuum brazing, obtain the bushing assembly (3).

3. A vacuum brazing method for a nozzle housing assembly according to claim 1, characterized in that, In Step 1, during the process of installing the bushing assembly (3) into the inner hole of the nozzle housing (4), insert the mandrel (14) through the bushing assembly (3) along the inclined cylindrical hole of the nozzle housing (4) and then into the bottom of the inner hole of the nozzle housing (4) to position the bushing assembly (3); among them, the mandrel (14) is taken out after fixing the bushing assembly (3) and the nozzle housing (4) using the process tabs (5).

4. A vacuum brazing method for a nozzle housing assembly according to claim 1, characterized in that In Step 1, the process of placing the first filler metal ring (6) at the brazing seam to be welded between the bushing assembly (3) and the nozzle housing (4) and fixing the bushing assembly (3) and the nozzle housing (4) using the process tabs (5) to obtain the first part to be welded is as follows: Place the first filler metal ring (6) at the brazing seam to be welded between the bushing assembly (3) and the nozzle housing (4); among them, the first filler metal ring (6) is placed close to the brazing seam to be welded between the bushing assembly (3) and the nozzle housing (4). Several process tabs (5) are evenly arranged circumferentially along the inner hole of the bushing assembly (3) and the inner hole of the nozzle housing (4) between the bushing assembly (3) and the nozzle housing (4); among them, using the energy storage spot welding method, weld the two ends of the process tab (5) to the bushing assembly (3) and the nozzle housing (4) by spot welding respectively.

5. A vacuum brazing method for a nozzle housing assembly according to claim 4, characterized in that, The distance between the process tab (5) and the first filler metal ring (6) is greater than or equal to 1 mm, and a flow blocker is applied to the middle part of the process tab (5).

6. A vacuum brazing method for a nozzle housing assembly according to claim 1, characterized in that, In Step 3, a welding fixture (9) is used to fix the exposed end of the auxiliary oil pipe (7) and the nozzle housing (4). Wherein, the welding fixture (9) includes a hollow cylindrical tube and a fixing ring plate, and the fixing ring plate is arranged at the first end of the hollow cylindrical tube; wherein, one side of the fixing ring plate is in close contact with the end of the nozzle housing (4), and the other side of the fixing ring plate is connected to the first end of the hollow cylindrical tube; The exposed end of the auxiliary oil pipe (7) passes through the fixing ring plate and the hollow cylindrical tube in sequence, and the end of the exposed end of the auxiliary oil pipe (7) is flush with the second end of the hollow cylindrical tube; the outer circumferential surface of the fixing ring plate and the outer circumferential surface of the end of the nozzle housing (4) and the end of the exposed end of the auxiliary oil pipe (7) and the second end of the hollow cylindrical tube are fixedly connected by alloy shims (8).

7. A vacuum brazing method for a nozzle housing assembly according to claim 6, characterized in that, The alloy shims (8) are connected to the fixing ring plate, the hollow cylindrical tube and the auxiliary oil pipe (7) by energy storage spot welding.

8. A vacuum brazing method for a nozzle housing assembly according to claim 1, characterized in that, The second solder ring (11) is arranged at the intersection line position between the auxiliary oil pipe (7) and the nozzle housing (4); a solder compensation section (12) is arranged in the semi-circular wedge-shaped space between the second solder ring and the inner wall of the inclined cylindrical hole of the nozzle housing.

9. A vacuum brazing method for a nozzle housing assembly according to claim 1, characterized in that, After Step 4, a step of repairing the brazing seam at the auxiliary oil pipe is further included; Wherein, the step of repairing the brazing seam at the auxiliary oil pipe is specifically as follows: Perform a weld quality inspection on the nozzle housing assembly in Step 4. If there are defects in the brazing seam position of the auxiliary oil pipe (7), insert a pencil lead (10) into the inner hole of the auxiliary oil pipe (7); then, a third solder ring (13) is sleeved on the pencil lead (10), and an adhesive is applied to the third solder ring (13); finally, vacuum brazing is performed to obtain the repaired nozzle housing assembly.

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