Thin-wall cylinder welding fixture with space transfer molded surface and welding method thereof

Abstract

The invention relates to the technical field of aero-engine welding, in particular to a thin-wall cylinder welding clamp with a space transfer molded surface and a welding method thereof.The thin-wall cylinder welding clamp comprises a base and a supporting plate fixedly connected with the base through a supporting column, a base plate is fixedly arranged on the upper surface of the supporting plate, a pressing plate is arranged above the base plate, and a welding opening is formed in the pressing plate; one end of the pressing plate is rotatably fixed on the supporting plate through a hinge, and the other end of the pressing plate is fixedly connected with the supporting plate through a buckle; a cavity is formed in the base plate and communicated with a ventilation pipe fixedly arranged at the bottom of the supporting plate, a welding seam argon protection groove is formed in the base plate, and ventilation holes communicated with the cavity are formed in the inner wall of the welding seam argon protection groove. The special welding fixture is designed according to the structural characteristics of thin wall and large diameter of the barrel to control the welding deformation and improve the welding quality, and by selecting a reasonable welding sequence and a pre-deformation method, the welding deformation and the welding stress are further reduced, and the production efficiency of the barrel is improved.

Description

Technical Field

[0001] The invention relates to the field of aviation engine welding technology, and in particular to a thin-walled cylinder welding fixture with a spatial transition profile and a welding method thereof. Background Art

[0002] The front section of the air intake casing is a thin-walled cylinder made of titanium alloy. Its structure is as follows: Figure 1 As shown in the figure, the cylinder structure is installed at the front of the aircraft engine and is one of the core parts of the aircraft engine. It is an important component for bearing loads and air intake. It becomes the most core component of the front section of the air intake casing. Therefore, the manufacturing accuracy and processing efficiency of the thin-walled cylinder determine the performance and output of the front section of the air intake casing.

[0003] At present, the thin-walled cylinder is mainly welded into a four-petal cylinder along the outer wall longitudinally by argon arc welding. Due to the high dimensional accuracy requirements of the cylinder, the cylinder has a complex spatial transition surface structure, a thin cylinder wall, a large diameter, and poor rigidity of the cylinder; and titanium alloy has large deformation during welding and is difficult to correct at room temperature. The weld is easily contaminated by air during the welding process, resulting in defects such as brittleness, cracks, and pores in the weld, which makes the work efficiency of welding the cylinder low and difficult to meet the needs of improving the performance and increasing the output of aircraft engines. Therefore, it is urgent to design a special welding fixture to improve the welding processing quality and processing efficiency of the thin-walled cylinder. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a thin-walled cylinder welding fixture with a spatial transition surface and a welding method thereof, aiming to improve the welding processing quality and processing efficiency of the thin-walled cylinder.

[0005] The technical solution adopted by the present invention is: a thin-walled cylinder welding fixture with a spatial transition surface, comprising: a base and a pillar fixedly arranged on the base, the top of the pillar fixedly connected to the support plate, the support plate being arranged parallel to the base; the upper surface of the support plate is fixedly provided with a pad for carrying the thin-walled cylinder to be welded, a pressure plate is provided above the pad, a welding opening is provided on the pressure plate, one end of the pressure plate is rotatably fixed on the hinge, the hinge is fixedly arranged on the support plate, and the other end of the pressure plate is fixedly connected to the support plate by a buckle; a cavity is provided inside the pad, and the cavity is connected to a ventilation pipe fixedly arranged at the bottom of the support plate, the pad is provided with a weld argon gas protection groove, and a plurality of groups of ventilation holes connected to the cavity are evenly distributed on the inner wall of the weld argon gas protection groove;

[0006] Furthermore, a mounting hole is provided at the end of the support plate, and the top end of the support column is inserted into the mounting hole;

[0007] Furthermore, a card plate is provided on the support plate, and both ends of the card plate are downwardly bent card edges, and a card head is provided in the middle of the card plate, and the card head is plugged into the mounting hole, and the distance between the two card edges is the width of the support plate;

[0008] Furthermore, reinforcing ribs are provided around the contact points between the pillar, the base and the support plate;

[0009] Furthermore, the upper surface of the backing plate is provided with a groove matching the shape of the cylinder to be welded;

[0010] Furthermore, the cavity of the backing plate is filled with metal wire;

[0011] Furthermore, the cross section of the welding joint is in the shape of an inverted trapezoid;

[0012] Furthermore, the hinge includes: a support, which is arranged on the outside of the pad and located at one end of the support plate close to the pillar, the support is fixed to the upper surface of the support plate by screws, a rotatable shaft is provided on the support, the rotation axis of the shaft is perpendicular to the weld seam of the cylinder to be welded, and one end of the pressure plate is fixedly connected to the shaft;

[0013] Furthermore, the buckle includes: a card seat, a column, a gasket and a locking bolt, wherein the card seat is fixed to the outer side of the support plate, a ball groove is provided on the top of the card seat, the bottom end of the column is a ball shaft, and the top end of the column has an external thread; the ball shaft is rotatably arranged in the ball groove, the end of the pressure plate has a U-shaped opening, the column passes through the U-shaped opening at the end of the pressure plate and is connected to the top end of the column by the gasket, and is locked by the locking bolt and the external thread at the top end of the column; the outer side of the gasket is provided with an opening;

[0014] The present invention also provides a method for welding a thin-walled cylinder using the welding fixture, comprising the following steps:

[0015] Step 1: Preparation before welding;

[0016] Pickle the thin-walled cylinder to be welded, and then use stainless steel wire wheels and other grinding tools to mechanically clean the weld to remove debris on the surface of the weld;

[0017] Step 2: Clamp parts:

[0018] Clamp the thin-walled cylinder to be welded onto the welding fixture, and ensure that the backing plate and the pressure plate of the welding fixture can fit the shape of the thin-walled cylinder to be welded tightly, and apply the clamping force evenly;

[0019] Step 3: Soldering:

[0020] The assembly tack welding is performed first using a welding sequence of interval welds, followed by argon arc welding of all welds.

[0021] The beneficial effects of the present application are:

[0022] The present application designs a special welding fixture according to the material properties of titanium alloy and the structural characteristics of the thin-walled and large-diameter cylinder body, so as to control the welding deformation, improve the welding quality, and further reduce the welding deformation and welding stress through the selection of reasonable welding sequence and pre-deformation method, so as to ensure the diameter and profile size of the cylinder body; at the same time, the welding parameters are reasonably adjusted, the welding qualified rate is improved, the appearance of the weld is beautified, and the overall manufacturing level of the titanium alloy cylinder body is improved.

[0023] And through the preset program, the automatic welding of the split hot forming cylinder body can be realized by applying the welding robot, and the single piece size precision and appearance quality of the front section cylinder body of the air intake casing manufactured by applying the automatic welding process of complex profile are high, the product qualified rate is more than 90%, and the problem of low product qualified rate is solved. At the same time, the production efficiency of the cylinder body is improved, and the input cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the front section of the air intake casing;

[0025] Figure 2 It is a schematic view of the overall structure of the welding fixture of the present application;

[0026] Figure 3 It is a schematic view of the structure of the pad of the present application;

[0027] Figure 4 It is a schematic view of the structure of the pressing plate of the present application;

[0028] Figure 5 It is a schematic view of the structure of the clamping plate of the present application;

[0029] In the figure: 1, base; 2, support column; 21, reinforcing rib; 3, support plate; 31, mounting hole; 311, clamping plate; 312, clamping edge; 313, clamping head; 32, lifting hole; 4, pad; 41, groove; 42, argon protection groove of weld; 5, folding page; 51, support; 52, screw; 53, rotating shaft; 6, clasp; 61, clamping seat; 62, ball shaft; 63, vertical column; 64, gasket; 65, locking bolt; 7, pressing plate; 71, rotating head; 72, fixed end; 8, air pipe. DETAILED DESCRIPTION

[0030] The technical solutions adopted by the present application will be clearly and completely explained and described below in combination with the drawings and specific embodiments of the specification.

[0031] Firstly, the present application provides a thin-walled cylinder welding fixture with a space switching profile, as shown in Figure 2 , which comprises:

[0032] The base 1 serves as the foundation of the entire welding fixture and is used to support the entire welding fixture on the ground and maintain stability. One end of a support column 2 is fixedly provided on the base 1 in the longitudinal direction, and a support plate 3 is fixedly connected to the other end of the support column 2, so that the support plate 3 is located above the base 1 and is arranged parallel to the base 1;

[0033] Preferably, the support plate 3 can be fixedly connected to the support plate 3 by opening a mounting hole 31 at the end of the support plate 3 and inserting the end of the support 2 into the mounting hole 31. Figure 5 As shown, a clamping plate 311 can also be provided on the support plate 3. The two ends of the clamping plate 311 are downwardly bent clamping edges 312, and a clamping head 313 is provided in the middle. The clamping head 313 is plugged into the mounting hole 31. The distance between the two clamping edges 312 is the width of the support plate 3, which is used to reinforce the plugging of the support plate 3 and the pillar 2 to prevent shaking.

[0034] In addition, as a preferred technical solution, reinforcing ribs 21 can be added around the contact points between the pillar 2 and the base 1 and the support plate 3 to improve the supporting strength of the pillar 2. Furthermore, lifting holes 32 can be fixed at the four corners of the support plate 3 to facilitate the use of the lifting holes 32 to cooperate with the lifting equipment to move the entire welding fixture.

[0035] The backing plate 4 is used to support the two halves of the cylinder to be welded from below and to position the cylinder to be welded. Figure 2-3 As shown, the backing plate 4 is fixedly arranged on the upper surface of the support plate 3, and its material is preferably metal copper. The two halves of the cylinder to be welded can be placed on the backing plate 4 in a manner of butting the cylinder walls, and the cylinder walls to be welded are kept above the backing plate 4, and the weld to be welded is parallel to the backing plate 4. The upper surface of the backing plate 4 is provided with a groove 41 that matches the shape of the cylinder to be welded, so that the cylinder to be welded can be placed more stably on the backing plate 4, thereby realizing the positioning of the cylinder to be welded;

[0036] Furthermore, a cavity is provided inside the backing plate 4, and the cavity is connected to a vent pipe 8 fixedly provided at the bottom of the support plate 3, and the vent pipe 8 is used to be connected to an external argon gas source. A weld argon gas protection groove 42 is also provided on the backing plate 4, and the weld argon gas protection groove 42 is provided below the weld of the cylinder to be welded. The surface of the weld argon gas protection groove 42 can be pre-coated with a solder resist to avoid welding adhesion. A plurality of groups of vent holes are evenly provided on the inner wall of the weld argon gas protection groove 42, and the vent holes are all connected to the cavity, that is, when the outer walls of the two-lobed cylinder are welded, argon gas can be introduced into the cavity of the backing plate 4 through the vent pipe 8, and sprayed to the weld of the two-lobed cylinder from the plurality of vent holes provided on the weld argon gas protection groove 42, so as to prevent the weld of the titanium alloy cylinder from being contaminated by air during the welding process and causing defects;

[0037] Preferably, during ventilation, metal wire may be filled in the cavity of the backing plate 4 to break up the argon flow ejected from the ventilation holes.

[0038] The pressing plate 7 is arranged above the backing plate 4 and is used to cooperate with the backing plate 4 to fix the cylinder to be welded. Specifically, Figure 4 As shown, a welding port 73 is provided in the middle of the pressing plate 7 to be welded to the weld seam of the cylinder. The cross section of the welding port 73 is preferably in the shape of an inverted trapezoid, so as to leave space for the welding gun during welding and facilitate the introduction and concentration of the solder.

[0039] The two ends of the pressing plate 7 are respectively a rotating head 71 and a fixed end 72. The rotating head 71 is used to connect with the hinge 5 to realize the pressing plate 7 to flip around the hinge 5. The fixed end 72 is used to connect and fix the buckle 6. That is, by controlling the pressing plate 7 to flip around the hinge 5, the pressing plate 7 is separated from the backing plate 4. After separation, the cylinder to be welded can be placed on the backing plate 4. After completion, the pressing plate 7 is flipped over and pressed against the cylinder to be welded. Then, the fixed end 72 of the pressing plate 7 is fixed to the buckle 6 to maintain the pressing force on the cylinder to be welded, thus completing the assembly process of the entire welding fixture.

[0040] Fold 5, such as Figure 3-4 As shown, it includes: a support 51, which is arranged on the outside of the pad 4 and is located on the support plate 3 at one end close to the pillar 2. It is fixed on the upper surface of the support plate 3 by a screw 52. A rotatable shaft 53 is provided on the support 51, and the rotation axis of the shaft 53 is perpendicular to the weld seam of the cylinder to be welded. By opening a through hole at the center of the rotating head 71 of the pressure plate 7 and fixing the shaft 53 in the through hole, the pressure plate 7 is flipped around the hinge 5.

[0041] Buckle 6, such as Figure 3-4 As shown, it includes: a holder 61, a column 63, a gasket 64 and a locking bolt 65, wherein the holder 61 is fixed to the outside of the support plate 3, that is, located outside the pad 4 and away from the hinge 5. A ball groove is provided on the top of the support plate 3, and the bottom end of the column 63 is a ball shaft 62. The top of the column 63 has an external thread; the ball shaft 62 is rotatably fixed in the ball groove, and a U-shaped opening is provided on the outside of the fixed end 72 of the pressure plate 7. The column 63 passes through the U-shaped opening on the outside of the fixed end 72 and is sleeved on the top of the column 63 by the gasket 64. The locking bolt 65 cooperates with the external thread on the top of the column 63 to lock it.

[0042] Furthermore, the outer side of the gasket 64 is provided with an opening for entry and exit when the column 63 is sleeved.

[0043] Secondly, the present invention also provides a thin-walled cylinder welding method using the above-mentioned welding fixture to control the welding deformation of the thin-walled cylinder, which specifically includes the following steps:

[0044] Step 1: Preparation before welding;

[0045] In order to prevent the weld of the thin-walled cylinder made of titanium alloy from being contaminated during the welding process, which may lead to defects such as brittleness, cracks, and pores in the weld, the thin-walled cylinder to be welded must be pickled before being clamped into the above-mentioned welding fixture. Then, a stainless steel wire wheel or other grinding tool is used to mechanically clean the weld (within a range of not less than 10 mm of the part joint) to clean the surface oxides, oil stains and other debris of the weld.

[0046] Step 2: Clamp parts:

[0047] By turning over the pressing plate 7, the thin-walled cylinder to be welded is clamped on the welding fixture, and it is ensured that the backing plate 4 and the pressing plate 7 of the welding fixture can closely fit the shape of the thin-walled cylinder to be welded, and the clamping force is evenly applied.

[0048] Step 3: Soldering:

[0049] First, after thorough pre-weld cleaning and assembly docking, use manual argon arc welding with low current and filler wire to perform assembly positioning welding. Furthermore, the four-petal cylinder is repaired before welding, a 1×45° groove is added at the weld, and an interval weld welding sequence is used during welding to ensure that the gap value of the later weld is slightly larger than the gap value of the earlier weld.

[0050] After the assembly positioning welding is completed, all welds are subjected to argon arc welding. Specifically, the heat input of the welding process is reduced by selecting a small current as much as possible within the standard range and shortening the welding time. At the same time, the welding speed is appropriately increased and the swing of the welding gun is reduced to control the weld width not to be too wide.

[0051] That is, the welding deformation during welding of thin-walled cylinders is controlled by the above method.

Claims

1. A thin-walled cylinder welding fixture with a spatial transition profile, comprising: A base (1) and a support (2) fixedly arranged on the base (1), the top end of the support (2) being fixedly connected to a support plate (3), and the support plate (3) being arranged parallel to the base (1); The upper surface of the support plate (3) is fixedly provided with a backing plate (4) for supporting the thin-walled cylinder to be welded, and a pressing plate (7) is provided above the backing plate (4), and a welding opening (73) is provided on the pressing plate (7). One end of the pressing plate (7) is rotatably fixed on the hinge (5), and the hinge (5) is fixedly provided on the support plate (3), and the other end of the pressing plate (7) is fixedly connected to the support plate (3) via a buckle (6); The invention is characterized in that a cavity is provided inside the backing plate (4), the cavity is connected to a vent pipe (8) fixedly arranged at the bottom of the support plate (3), a weld argon gas protection groove (42) is provided on the backing plate (4), and a plurality of groups of vent holes connected to the cavity are evenly distributed on the inner wall of the weld argon gas protection groove (42).

2. A thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: A mounting hole (31) is provided at the end of the support plate (3), and the top end of the support column (2) is inserted into the mounting hole (31).

3. A thin-walled cylinder welding fixture with a spatial transition profile according to claim 2, characterized in that: A card plate (311) is provided on the support plate (3), and both ends of the card plate (311) are downwardly bent card edges (312). A card head (313) is provided in the middle of the card plate (311), and the card head (313) is plugged into the mounting hole (31), and the distance between the two card edges (312) is the same as the width of the support plate (3).

4. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: Reinforcing ribs (21) are provided around the contact points between the support (2), the base (1) and the support plate (3).

5. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: The upper surface of the backing plate (4) is provided with a groove (41) that matches the shape of the cylinder to be welded.

6. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: The cavity of the backing plate 4 is filled with metal wire.

7. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: The cross section of the welding opening (73) is in the shape of an inverted trapezoid.

8. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: The hinge (5) comprises a support (51), the support (51) being arranged on the outside of the pad (4) and located on one end of the support plate (3) close to the pillar (2), the support (51) being fixed on the upper surface of the support plate (3) by means of screws (52), a rotatable shaft (53) being arranged on the support (51), the axis of rotation of the shaft (53) being arranged perpendicular to the weld seam of the cylinder to be welded, and one end of the pressing plate (7) being fixedly connected to the shaft (53).

9. The thin-walled cylinder welding fixture with a spatial transition profile according to claim 1, characterized in that: The buckle (6) includes: a card seat (61), a column (63), a gasket (64) and a locking bolt (65), wherein the card seat (61) is fixed to the outside of the support plate (3), and a ball groove is provided on the top of the card seat (61). The bottom end of the column (63) is a ball shaft (62), and the top end of the column (63) has an external thread; the ball shaft (62) is rotatably fixed in the ball groove, and a U-shaped opening is provided at the end of the pressure plate (7). The column (63) passes through the U-shaped opening at the end of the pressure plate (7) and is sleeved on the top end of the column (63) by the gasket (64), and is locked by the locking bolt (65) in cooperation with the external thread at the top end of the column (63); An opening is provided on the outer side of the gasket (64).

10. A welding method using the thin-walled cylinder welding fixture with a spatial transition profile according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Preparation before welding; Pickle the thin-walled cylinder to be welded, and then use stainless steel wire wheels and other grinding tools to mechanically clean the weld to remove debris on the surface of the weld; Step 2: Clamp parts: The thin-walled cylinder to be welded is mounted on the welding fixture, and the backing plate (4) and the pressure plate (7) of the welding fixture are ensured to be able to fit closely to the surface of the thin-walled cylinder to be welded, and the clamping force is applied evenly; Step 3: Soldering: The assembly tack welding is performed first using a welding sequence of interval welds, followed by argon arc welding of all welds.

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