A laser welding method for engine igniters

Abstract

This invention relates to a laser welding method for engine igniters. The method includes: laser spot welding and circumferential welding of an oxidizer nozzle and a fuel nozzle; laser spot welding of a secondary fuel nozzle and an inner bottom; laser spot welding of an ignition nozzle and an inner bottom, and a fuel nozzle and an inner bottom; laser spot welding and circumferential welding of a head blank and an inner bottom; laser circumferential welding of an ignition nozzle and an inner bottom; laser circumferential welding of a secondary fuel nozzle and an inner bottom; laser circumferential welding of a fuel nozzle and an inner bottom; and laser circumferential welding of an ignition nozzle and a head blank, and an oxidizer nozzle and a head blank. The weld penetration depth can reach 0.8–4.0 mm, making it more suitable for welding in small areas. The weld seam becomes narrower, which can be reduced to 0.8 mm. The weld seam width effectively solves the problems of easy weld collapse, easy weld penetration, and weld leakage. It is superior to arc welding and plasma arc welding in terms of efficiency, quality, and working environment pollution. The pressure resistance and sealing performance exceed the test indicators and do not deform under pressure.

Description

Technical Field

[0001] This invention belongs to the field of welding engine igniters, and specifically relates to a laser welding method for engine igniters. Background Technology

[0002] With the continuous development of aerospace technology, the requirements for related product technologies are also constantly increasing. As a device that provides fuel to aviation equipment and stabilizes the flame, the engine igniter is mainly composed of a head and a body. The head is composed of an inner bottom, a head blank, several oxidizer nozzles, several fuel nozzles, and several auxiliary fuel nozzles, etc., consisting of dozens of parts. It requires the welding of nearly 90 welds. The welds are located in close proximity and are numerous. Moreover, it operates under high-pressure and sealed conditions, and must withstand at least 3~12MPa of hydraulic pressure and 3~5MPa of air pressure. This places high demands on the strength and sealing performance of each weld.

[0003] Currently, the welding of engine ignition devices uses plasma arc welding and electric arc welding methods.

[0004] Although the energy density of plasma arc welding is much higher than that of arc welding, it is still insufficient for the narrow weld seam conditions of the igniter. When using plasma arc welding for fuel nozzles, auxiliary fuel nozzles and inner bottoms, due to the large number of weld seams of the igniter and the narrow and close spacing, defects such as weld leakage and weld collapse are easy to occur due to the limitations of the igniter structure. The yield rate is very low, which affects the airtightness and pressure resistance of the product.

[0005] Traditional arc welding has high heat input and low welding efficiency. To make the igniter meet the needs of plasma arc welding, the design needs to be changed to increase the size of the igniter. This not only increases the design and material costs of the product, but also increases its subsequent launch weight. In addition, the product is prone to thermal deformation, which can lead to assembly failure, affect assembly accuracy, and reduce production efficiency.

[0006] Laser welding utilizes a high-energy-density laser beam as a heat source, offering advantages such as a small range of metallographic changes in the heat-affected zone, reduced deformation, the ability to focus the laser beam to weld small and closely spaced components, and high welding efficiency. Therefore, developing a laser welding method suitable for engine igniters can effectively improve the quality of the igniters after welding. Summary of the Invention

[0007] The present invention aims to solve at least one of the above-mentioned technical problems. The present invention provides a laser welding method for engine igniters, which meets the various weld requirements of igniters. After welding, the pressure-bearing performance and sealing performance of the igniter are significantly improved and no deformation occurs under pressure.

[0008] The technical solution adopted by this invention to solve its technical problem is:

[0009] A laser welding method for an engine igniter, the method comprising:

[0010] S1: Assemble the oxidizer nozzle and fuel nozzle;

[0011] After laser spot welding along the annular trajectory at the connection between the fuel nozzle and the oxidizer nozzle, laser welding is then performed along the same annular trajectory to form the first annular weld. The penetration depth of the first annular weld is 1~1.3mm and the weld width is 1.2~1.3mm.

[0012] S2: Assembly of auxiliary fuel nozzle and inner bottom;

[0013] Laser spot welding will be performed along the circular trajectory at the connection point between the auxiliary fuel nozzle and the reverse side of the inner bottom.

[0014] S3: Assemble the ignition nozzle, the fuel nozzle and the oxidizer nozzle from step S1 onto the inner bottom and head blank;

[0015] Laser spot welding is performed along a circular trajectory at the connection point between the ignition nozzle and the reverse side of the inner bottom.

[0016] Laser spot welding is performed along a circular trajectory at the connection point between the fuel nozzle and the reverse side of the inner bottom.

[0017] S4: After laser spot welding along the annular trajectory connecting the head blank and the inner bottom, laser welding is then performed along the same annular trajectory to form a second annular weld. The penetration depth of the second annular weld is 2.0~2.2mm and the penetration width is 1.1~1.3mm.

[0018] S5: A third ring weld is formed by laser welding along the annular trajectory of the laser spot welding between the ignition nozzle and the reverse side of the inner bottom. The penetration depth of the third ring weld is 0.8~0.9mm and the penetration width is 0.85~0.95mm.

[0019] S6: A fourth ring weld is formed by laser welding along the annular trajectory of the laser spot welding between the auxiliary fuel nozzle and the inner bottom reverse side. The penetration depth of the fourth ring weld is 0.8~0.9mm and the penetration width is 0.8~0.9mm.

[0020] S7: The fifth ring weld is formed by laser welding along the circular trajectory of the spot welding between the fuel nozzle and the inner bottom. The penetration depth of the fifth ring weld is 0.8~0.9mm and the weld width is 0.8~0.9mm.

[0021] S8: Laser welding is performed along the annular trajectory at the connection between the ignition nozzle and the head blank to form the sixth ring weld. The penetration depth of the sixth ring weld is 1.5~1.7mm and the penetration width is 1.1~1.3mm.

[0022] The seventh ring weld is formed by laser welding along the annular trajectory at the connection between the oxidant nozzle and the head blank. The penetration depth of the seventh ring weld is 1.5~1.71mm and the penetration width is 1.1~1.3mm.

[0023] Furthermore, in step S1, during assembly, one end of the oxidizer nozzle is inserted into the fuel nozzle until it makes contact with the limit position.

[0024] Furthermore, in step S1, when laser spot welding the oxidant nozzle and the fuel nozzle, the annular trajectory is set around the outer circumference of the fuel nozzle and the oxidant nozzle, and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +0.5~+2.2mm. Spot welding can be used to fix the oxidant nozzle and the fuel nozzle first, further improving the welding accuracy.

[0025] Furthermore, a three-jaw chuck is used to clamp and fix the oxidizer nozzle and the fuel nozzle.

[0026] Furthermore, in step S1, during laser welding of the first ring weld, the welding power is 600~800w, the welding speed is 30~50mm / s, and the laser defocusing amount is -8~-4mm. By using negative defocusing amount, a larger defocusing amount can be used to eliminate weld porosity defects, enhance weld strength, and further meet the aspect ratio requirement.

[0027] Furthermore, in step S2, during assembly, the auxiliary fuel nozzle is assembled in the first mounting hole of the inner bottom, further improving the positioning accuracy.

[0028] Furthermore, in step S2, when laser spot welding the auxiliary fuel nozzle and the inner bottom, the annular trajectory is set around the outer circumference of the auxiliary fuel nozzle and the first mounting hole, and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +0.5~1.5mm. The auxiliary fuel nozzle and the inner bottom can be fixed by spot welding first, which further improves the welding accuracy.

[0029] Furthermore, in step S2, a welding point is set every 60° on the circular trajectory.

[0030] Furthermore, in step S3, during assembly, the ignition nozzle is installed in the second mounting hole of the head blank and the third mounting hole of the inner bottom, and the head blank and the inner bottom are in limiting contact. The ignition nozzle can be used to position and assemble the head blank and the inner bottom first.

[0031] Furthermore, in step S3, when spot welding the ignition nozzle and the inner bottom with laser, the annular trajectory is set around the outer circumference of the ignition nozzle and the third mounting hole, and multiple spaced weld points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +1~2mm. The ignition nozzle and the inner bottom can be fixed by spot welding first.

[0032] Furthermore, in step S3, during assembly, the fuel nozzle is assembled in the fourth mounting hole of the inner bottom; the oxidizer nozzle is assembled in the fifth mounting hole of the head blank, further improving the positioning accuracy.

[0033] Furthermore, in step S3, when spot welding the fuel nozzle and the inner bottom with laser, the annular trajectory is set around the outer circumference of the fuel nozzle and the fourth mounting hole, and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~200W, and the laser defocusing amount is +1~2mm. The fuel nozzle and the inner bottom can be fixed by spot welding first, which further improves the welding accuracy.

[0034] Furthermore, in step S3, when laser spot welding the fuel nozzle to the inner bottom, a welding point is set every 60° on the circular trajectory.

[0035] Furthermore, in step S4, when laser spot welding the head blank and the inner bottom, the annular trajectory is set around the outer circumference of the head blank and the inner bottom, and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +1~2mm. The head blank and the inner bottom can be fixed by spot welding first, which further improves the welding accuracy.

[0036] Furthermore, in step S4, when laser spot welding the head blank and the inner bottom, a welding point is set every 10° on the circular trajectory.

[0037] Furthermore, in step S4, before laser welding of the second ring weld: apply anti-spatter oil; during laser welding: welding power 700~750w, welding speed 30~50mm / s, laser defocusing amount is +0.5~2.5mm; after laser welding: remove anti-spatter oil to protect the product and prevent splashes from adhering to the product during this process.

[0038] Furthermore, in step S5, during laser welding of the third ring weld, the welding power is 400~550w, the welding speed is 25~40mm / s, and the laser defocusing distance is +2~4.5mm, which further makes the weld sufficiently narrow and the penetration depth appropriate, avoiding improper use of a large defocusing distance-to-width ratio, which could cause the nozzle to collapse and the weld to fail to seal the product.

[0039] Furthermore, in step S6, before laser welding of the fourth ring weld: the whole is cooled to room temperature. During laser welding: the welding power is 400~500w, the welding speed is 30~40mm / s, and the laser defocusing amount is +2~3mm, which can reduce welding deformation. When the inner bottom thickness is relatively thin, by further controlling the welding power and welding speed, the penetration depth and width can be appropriate without welding through, thereby further improving the welding strength.

[0040] Furthermore, in step S7, during laser welding of the fifth ring weld, the welding power is 350~450w, the welding speed is 30~40mm / s, and the laser defocusing amount is +2~3mm. This can avoid excessive heat accumulation, which could lead to localized weld penetration defects and weld slag entering the product, thereby further improving the weld sealing effect.

[0041] Furthermore, in step S8, during laser welding of the sixth ring weld, the annular trajectory is set around the outer circumference of the ignition nozzle and the second mounting hole, the welding power is 700~850w, the welding speed is 25~35mm / s, and the laser defocusing amount is +1~3.2mm, which can make the weld depth and width appropriate without weld penetration, thereby further improving the welding strength.

[0042] Furthermore, in step S8, during laser welding of the seventh ring weld, the annular trajectory is set around the outer circumference of the oxidant nozzle and the fifth mounting hole, the welding power is 700~850w, the welding speed is 25~35mm / s, and the laser defocusing amount is +1~3.2mm, which can make the weld depth and width suitable without weld penetration, thereby further improving the welding strength.

[0043] Furthermore, it also includes:

[0044] S9: Assemble the ignition nozzle and head cover plate;

[0045] The eighth ring weld is formed by laser welding along the annular trajectory at the connection between the ignition nozzle and the head cover plate. The penetration depth of the eighth ring weld is 1.3~1.5mm and the penetration width is 1.2~1.3mm.

[0046] S10: The ninth ring weld is formed by laser welding along the trajectory at the connection between the support base and the head cover plate. The penetration depth of the ninth ring weld is 3.3~3.6mm and the penetration width is 2.9~3.1mm.

[0047] S11: Assemble the head side cover and the head top cover;

[0048] Laser spot welding along a circular trajectory at the connection between the head side cover and the head top cover;

[0049] S12: Laser spot welding along the annular trajectory at the connection between the body and the inner bottom, and then laser welding along the same annular trajectory to form the tenth ring weld. The penetration depth of the tenth ring weld is 2.0~2.2mm and the penetration width is 1.1~1.3mm.

[0050] S13: A connecting ring is assembled on the outside of the body and the inner bottom. The eleventh ring weld is formed by laser welding along the annular trajectory at the connection between the connecting ring and the head blank. The eleventh ring weld has a penetration depth of 3.3~3.6mm and a penetration width of 2.9~3.1mm.

[0051] S14: The twelfth ring weld is formed by laser welding along the circular trajectory of the laser spot welding between the head side cover plate and the head top cover plate. The penetration depth of the twelfth ring weld is 4.1~4.4mm and the penetration width is 3.4~3.6mm.

[0052] S15: The thirteenth ring weld is formed by laser welding along the annular trajectory between the head side cover plate and the head blank. The penetration depth of the thirteenth ring weld is 4.1~4.4mm and the penetration width is 3.4~3.6mm.

[0053] S16: The fourteenth ring weld is formed by laser welding along the annular trajectory at the connection between the connecting ring and the body. The penetration depth of the fourteenth ring weld is 3.3~3.6mm and the penetration width is 2.9~3.1mm.

[0054] Furthermore, in step S9, during assembly: the ignition nozzle is assembled into the sixth mounting hole of the head cover plate, further improving the positioning accuracy.

[0055] Furthermore, in step S9, during laser welding of the eighth ring weld, the annular trajectory is set along the outer circumference of the ignition nozzle and the sixth mounting hole, the welding power is 650~750W, the welding speed is 25~35mm / s, and the laser defocusing amount is +2~+4mm.

[0056] Furthermore, in step S10, during laser welding of the ninth ring weld, the welding trajectory is divided into several segments along the outer circumference of the support base and the head cover plate. The welding trajectory overlaps by 10~15mm between adjacent segments, the welding power is 2900~3200W, the welding speed is 15~25mm / s, and the laser defocusing amount is -6~-3mm, further optimizing the aspect ratio.

[0057] Furthermore, in step S10, during the laser welding of the ninth ring weld, coaxial air blowing and dual-side-shaft assisted air blowing are used to further improve the weld sealing performance.

[0058] Furthermore, in step S11, during assembly, the head cover plate is assembled into the seventh mounting hole of the head side cover plate, further improving the positioning accuracy.

[0059] Furthermore, in step S11, when laser spot welding the head side cover plate and the head top cover plate, the annular trajectory is set around the outer circumference of the head side cover plate and the seventh mounting hole, and multiple spaced weld points are welded along the annular trajectory. The spot welding power is 1200~1500W, the laser defocusing amount is +2~+5mm, and the aspect ratio is further optimized.

[0060] Furthermore, in step S12, when laser spot welding the body and the inner bottom, a circular trajectory is set around the outer circumference of the end of the body and the inner bottom, and multiple spaced weld points are welded along the circular trajectory. The spot welding power is 200W and the laser defocusing amount is +2mm.

[0061] Furthermore, in step S12, during laser welding of the tenth ring weld, the welding power is 700~850W, the welding speed is 30~50mm / s, and the laser defocusing amount is +0.5~2.5mm, further optimizing the aspect ratio.

[0062] Furthermore, in step S13, the connecting ring is composed of multiple arc-shaped connectors. When the eleventh ring weld is laser welded, the trajectory is an arc-shaped trajectory around the arc-shaped connector and the outside of the head blank. Each arc-shaped connector and the head blank are laser welded in multiple segments to form the eleventh ring weld. The welding power is 1400~1600W, the welding speed is 15~30mm / s, and the laser defocusing amount is -6~-2mm, which further improves the welding strength.

[0063] Furthermore, in step S13, the arc trajectory includes two segments with a welding length of 20°.

[0064] Furthermore, in step S14, when welding the twelfth ring weld, the welding power is 3200~3800W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm.

[0065] Furthermore, in step S15, when welding the thirteenth ring weld, the annular trajectory is set around the outer circumference of the head side cover plate and the head blank, the welding power is 3200~3800W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm.

[0066] Furthermore, in step S16, when welding the fourteenth ring weld, the annular trajectory is set around the outer circumference of the connecting ring and the head blank, the welding power is 2800~3000W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm, which further improves the sealing performance.

[0067] Compared with the prior art, the beneficial effects of the present invention are:

[0068] (1) This invention uses laser welding to replace the original electric arc welding and plasma arc welding. By taking into account the influence of laser welding stress on deformation and optimizing the assembly sequence, spot welding + circumferential laser welding, and matching the penetration depth and weld width, it successfully solves the problem of weld collapse and leakage caused by excessively wide welds when welding auxiliary fuel nozzles, fuel nozzles and inner bottoms using plasma arc welding, which makes it impossible to seal the product. The welds become narrower and more suitable for welding in small areas. Multiple welds can achieve sufficient penetration depth (0.8~4.0mm) and narrow weld width. While ensuring penetration depth, laser welding can reduce the weld width to 0.8mm, so that the welds no longer interfere with each other, meeting the various weld requirements of engine igniters. It effectively solves the problems of easy weld collapse and easy weld penetration and leakage, and is superior to arc welding and plasma arc welding in terms of efficiency, quality and working environment pollution.

[0069] (2) The present invention further uses different types of laser light sources, with a welding power range of 200w~3500w, a welding speed of 20~50mm / s, and a laser defocusing amount of -8~+8mm to optimize the welding index. After welding, the finished igniter was tested and its pressure bearing performance and airtightness exceeded the test index and it did not deform under pressure. Attached Figure Description

[0070] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0071] Figure 1 This is a welding flowchart of a real-time example of the present invention;

[0072] Figure 2 This is a schematic diagram of the welding position according to an embodiment of the present invention;

[0073] Figure 3 This is a metallographic image of the first circumferential weld in Embodiment 1 of the present invention;

[0074] Figure 4 This is the weld appearance of the first circumferential weld in Embodiment 1 of the present invention;

[0075] Figure 5 This is a schematic diagram of the weld joint between the auxiliary fuel nozzle and the inner bottom in Embodiment 1 of the present invention;

[0076] Figure 6 This is a metallographic image of the second circumferential weld in Embodiment 1 of the present invention;

[0077] Figure 7 This is the weld appearance of the second circumferential weld in Embodiment 1 of the present invention;

[0078] Figure 8 This is a metallographic image of the third ring weld of Embodiment 1 of the present invention;

[0079] Figure 9 This is the weld appearance of the third ring weld in Embodiment 1 of the present invention;

[0080] Figure 10 This is a metallographic image of the fourth ring weld of Embodiment 1 of the present invention;

[0081] Figure 11 This is the weld appearance of the fourth ring weld in Embodiment 1 of the present invention;

[0082] Figure 12 This is a metallographic image of the fifth ring weld of Embodiment 1 of the present invention;

[0083] Figure 13 This is the weld appearance of the fifth ring weld in Embodiment 1 of the present invention;

[0084] Figure 14This is a metallographic image of the sixth ring weld of Embodiment 1 of the present invention;

[0085] Figure 15 This is the weld appearance of the sixth ring weld in Embodiment 1 of the present invention;

[0086] Figure 16 This is a metallographic image of the seventh ring weld of Embodiment 1 of the present invention;

[0087] Figure 17 This is the weld appearance of the seventh ring weld in Embodiment 1 of the present invention;

[0088] Figure 18 This is a metallographic image of the eighth ring weld of Embodiment 1 of the present invention;

[0089] Figure 19 This is the weld appearance of the eighth ring weld in Embodiment 1 of the present invention;

[0090] Figure 20 This is a schematic diagram of the welding trajectory of the ninth ring weld in Embodiment 1 of the present invention;

[0091] Figure 21 This is a metallographic image of the ninth ring weld of Embodiment 1 of the present invention;

[0092] Figure 22 This is the weld appearance of the ninth ring weld in Embodiment 1 of the present invention;

[0093] Figure 23 This is a metallographic image of the tenth ring weld of Embodiment 1 of the present invention;

[0094] Figure 24 This is the weld appearance of the tenth ring weld in Embodiment 1 of the present invention;

[0095] Figure 25 This is a metallographic image of the eleventh ring weld in Embodiment 1 of the present invention;

[0096] Figure 26 This is the weld appearance of the eleventh ring weld in Embodiment 1 of the present invention;

[0097] Figure 27 This is a metallographic image of the twelfth ring weld in Embodiment 1 of the present invention;

[0098] Figure 28 This is a metallographic image of the thirteenth ring weld of Embodiment 1 of the present invention;

[0099] Figure 29 This is the weld appearance of the fourteenth ring weld in Embodiment 1 of the present invention;

[0100] Figure 30 This is a metallographic image of the fourteenth ring weld of Embodiment 1 of the present invention.

[0101] The diagram shows the following markings: Oxidizer nozzle 1, Fuel nozzle 2, First ring weld 3, Secondary fuel nozzle 4, Inner bottom 5, First mounting hole 6, Ignition nozzle 7, Head blank 8, Second mounting hole 9, Third mounting hole 10, Fourth mounting hole 11, Fifth mounting hole 12, Second ring weld 13, Third ring weld 14, Fourth ring weld 15, Fifth ring weld 16, Sixth ring weld 17, Seventh ring weld 18, Support base 19, Head top cover plate 20, Sixth mounting hole 21, Eighth ring weld 22, Straight section 23, Arc section 24, Overlap position 25, Ninth ring weld 26, Head side cover plate 27, Seventh mounting hole 28, Body 29, Tenth ring weld 30, Connecting ring 31, Eleventh ring weld 32, Twelfth ring weld 33, Thirteenth ring weld 34, Fourteenth ring weld 35, Weld point 36. Detailed Implementation

[0102] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Example 1:

[0103] like Figure 1 and Figure 2 The image shows a preferred embodiment of the laser welding method for an engine igniter according to the present invention, the method comprising the following steps:

[0104] S1. Assemble the oxidizer nozzle 1 and the fuel nozzle 2: Insert one end of the oxidizer nozzle 1 into the fuel nozzle 2 until it makes contact at the limit position;

[0105] The oxidizer nozzle 1 and the fuel nozzle 2 are clamped and fixed using a three-jaw chuck;

[0106] Laser spot welding is performed along the annular trajectory at the connection between fuel nozzle 2 and oxidant nozzle 1. The annular trajectory is set around the outer circumference of fuel nozzle 2 and oxidant nozzle 1. Multiple spaced weld points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +2.2mm.

[0107] Then, laser welding is performed along the circular trajectory to form the first ring weld 3. The welding power is 400W, the welding speed is 50mm / s, and the laser defocusing amount is -6mm. Figure 3 and Figure 4 As shown, the penetration depth of the first ring weld 3 is 1.229 mm and the weld width is 1.271 mm. The weld surface is well protected and is silvery-white. Slight yellowing around the weld is acceptable. The weld has no defects such as porosity, lack of fusion, or bursting.

[0108] S2. Assemble the auxiliary fuel nozzle 4 and the inner bottom 5: The auxiliary fuel nozzle 4 is assembled in the first mounting hole 6 of the inner bottom 5. The thickness of the inner bottom 5 is 1 mm, and the assembly step between the auxiliary fuel nozzle 4 and the inner bottom 5 is less than 60 micrometers.

[0109] Laser spot welding is performed along a circular trajectory at the connection point between the auxiliary fuel nozzle 4 and the reverse side of the inner bottom 5. This circular trajectory is set around the outer circumference of the auxiliary fuel nozzle 4 and the first mounting hole 6. Figure 5 As described above, a welding point is set every 60° on the circular trajectory, and 6 spaced welding points 36 are welded along the circular trajectory. The spot welding power is 220W, the laser defocusing amount is +1mm, and the spot welding diameter is smaller than the diameter of the circumferential weld to be welded.

[0110] S3. Assemble the ignition nozzle 7, the fuel nozzle 2 and the oxidizer nozzle 1 from step S1 onto the inner bottom 5 and the head blank 8: First, use the ignition nozzle 7 to position and assemble the head blank 8 and the inner bottom 5. The ignition nozzle 7 is assembled in the second mounting hole 9 of the head blank 8 and the third mounting hole 10 of the inner bottom 5. The head blank 8 and the inner bottom 5 are in limited contact. Then, assemble the fuel nozzle 2 and the oxidizer nozzle 1 from step S1, so that the fuel nozzle 2 is assembled in the fourth mounting hole 11 of the inner bottom 5 and the oxidizer nozzle 1 is assembled in the fifth mounting hole 12 of the head blank 8. The assembly step of the ignition nozzle 7, the fuel nozzle 2 and the inner bottom 5 is less than 60 micrometers.

[0111] Laser spot welding is performed along the annular trajectory connecting the ignition nozzle 7 and the inner bottom 5. The annular trajectory is set around the outer circumference of the ignition nozzle 7 and the third mounting hole 10. A welding point is set every 45° on the annular trajectory. Eight spaced welding points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +1mm.

[0112] Laser spot welding is performed along the annular trajectory connecting the fuel nozzle 2 and the inner bottom 5. The annular trajectory is set around the outer circumference of the fuel nozzle 2 and the fourth mounting hole 11. A welding point is set every 60° on the annular trajectory. Six spaced welding points are welded along the annular trajectory. The spot welding power is 200W and the laser defocusing amount is +1mm.

[0113] S4: Laser spot welding along the annular trajectory connecting the head blank 8 and the inner bottom 5. The annular trajectory is set around the outer circumference of the head blank 8 and the inner bottom 5. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +1mm.

[0114] Before laser welding, anti-spatter oil is applied, and then laser welding is performed along the circular trajectory to form the second ring weld 13. The welding power is 750W, the welding speed is 50mm / s, and the laser defocusing distance is +2.2mm. After laser welding, the anti-spatter oil is wiped off. Figure 6 and Figure 7As shown, the penetration depth of the second ring weld 13 is 2.045 mm and the weld width is 1.159-1.244 mm.

[0115] S5: Laser welding is performed along the circular trajectory of the spot welding between the ignition nozzle 7 and the inner bottom 5 to form the third ring weld 14. The welding power is 500W, the welding speed is 35mm / s, and the laser defocusing amount is +4.2mm. Figure 8 and Figure 9 As shown, the penetration depth of the third ring weld 14 is 8.65 mm, the weld width is 0.85~0.95 mm, and the inner diameter of the weld does not collapse.

[0116] S6: After the entire assembly cools to room temperature, laser welding is performed along the circular trajectory of the spot welding between the auxiliary fuel nozzle 4 and the inner bottom 5 to form the fourth ring weld 15. The welding power is 500W, the welding speed is 35mm / s, and the laser defocusing amount is +4.2mm. Figure 10 and Figure 11 As shown, the penetration depth of the fourth ring weld 15 is 0.887 mm and the weld width is 0.8~0.9 mm. It does not penetrate through the weld and the inner diameter of the weld does not collapse.

[0117] S7: Laser welding along the circular trajectory of spot welding between fuel nozzle 2 and the inner bottom 5 forms the fifth ring weld 16. The welding power is 450W, the welding speed is 33mm / s, and the laser defocusing amount is +4.2mm. Figure 12 and Figure 13 As shown, the penetration depth of the fifth ring weld 16 is 0.882 mm and the weld width is 0.8~0.9 mm. It did not penetrate through the weld and the inner diameter of the weld did not collapse.

[0118] S8: Laser welding is performed along the annular trajectory at the connection between the ignition nozzle 7 and the head blank 8 to form the sixth annular weld 17. The annular trajectory is set around the outer circumference of the ignition nozzle 7 and the second mounting hole 9. The welding power is 800W, the welding speed is 35mm / s, and the laser defocusing amount is +3.2mm. Figure 14 and Figure 15 As shown, the penetration depth of the sixth ring weld 17 is 1.554 mm and the weld width is 1.15~1.25 mm, and it is not fully penetrated.

[0119] A seventh ring weld 18 is formed by laser welding along a ring trajectory at the connection between the oxidant nozzle 1 and the head blank 8. The ring trajectory is set around the outer circumference of the oxidant nozzle 1 and the fifth mounting hole 12. The welding power is 800W, the welding speed is 35mm / s, and the laser defocusing amount is +3.2mm. Figure 16 and Figure 17 As shown, the penetration depth of the seventh ring weld 18 is 1.705 mm and the weld width is 1.15~1.25 mm, and it is not fully penetrated.

[0120] S9. Assemble the ignition nozzle 7 and the head cover plate 20: The ignition nozzle 7 is assembled in the sixth mounting hole 21 of the head cover plate 20.

[0121] The eighth circumferential weld 22 is formed by laser welding along the annular trajectory at the connection between the ignition nozzle 7 and the head cover plate 20. The annular trajectory is set along the outer circumference of the ignition nozzle 7 and the sixth mounting hole 21. The welding power is 650W, the welding speed is 25mm / s, and the laser defocusing amount is +2.2mm. Figure 18 and Figure 19 As shown, the penetration depth of the eighth ring weld 22 is 1.455 mm and the weld width is 1.15~1.25 mm;

[0122] S10: Laser welding is performed along the trajectory at the connection between the support base 19 and the head cover plate 20 to form the ninth ring weld 26, such as... Figure 20 As shown, the welding trajectory along the outer circumference of the support base 19 and the head cover plate 20 is divided into four segments, including two straight segments 23 on both sides and two arc segments 24 at the top and bottom. The welding trajectory overlaps by 10mm between adjacent segments. The welding power is 300W, the welding speed is 20mm / s, the laser defocusing distance is -6mm, and coaxial air blowing and dual-side-axis assisted air blowing are used. Figure 21 and Figure 22 As shown, the penetration depth of weld 26 in the ninth ring is 3.419 mm and the weld width is 3 ± 0.06 mm.

[0123] S11. Assemble the head side cover 27 and the head top cover 20: The head top cover 20 is assembled in the seventh mounting hole 28 of the head side cover 27.

[0124] Laser spot welding is performed along the annular trajectory at the connection between the head side cover plate 27 and the head top cover plate 20. The annular trajectory is set around the outer circumference of the head side cover plate 27 and the seventh mounting hole 28. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 1500W and the laser defocusing amount is +5mm.

[0125] S12: Laser spot welding along the annular trajectory connecting the body 29 and the inner bottom 5. The annular trajectory is set around the end of the body 29 and the outer circumference of the inner bottom 5. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 200W and the laser defocusing amount is +2mm.

[0126] Then, laser welding is performed along the same circular trajectory to form the tenth ring weld 30. The welding power is 800W, the welding speed is 50mm / s, and the laser defocusing distance is +2.2mm. Figure 23 and Figure 24 As shown, the penetration depth of the tenth ring weld 30 is 2.045 mm and the weld width is 1.159 mm;

[0127] S13: A connecting ring 31 is assembled on the outside of the body 29 and the inner bottom 5. The connecting ring 31 consists of two arc-shaped connecting parts. An eleventh ring weld 32 is formed by laser welding along the annular trajectory at the connection point between the connecting ring 31 and the head blank 8. The trajectory is an arc-shaped trajectory around the arc-shaped connecting parts and the outside of the head blank 8. The arc-shaped trajectory includes two segments with a welding length of 20°. Each arc-shaped connecting part is laser welded to the head blank 8 to form the eleventh ring weld 32. The welding power is 1600W, the welding speed is 20mm / s, and the laser defocusing amount is -6mm. Figure 25 and Figure 26 As shown, the penetration depth of the eleventh ring weld 32 is 3.419 mm and the weld width is 3 ± 0.06 mm.

[0128] S14: Laser welding is performed along the annular trajectory of laser spot welding between the head side cover plate 27 and the head top cover plate 20 to form the twelfth ring weld 33. The welding power is 3500W, the welding speed is 20mm / s, and the laser defocusing amount is +6mm. Figure 27 As shown, the penetration depth of weld 33 in the twelfth ring is 4.117 mm and the weld width is 3.488 mm.

[0129] S15: Using a fixture to clamp the entire assembly, laser weld along the annular trajectory between the head side cover plate 27 and the head blank 8 to form the thirteenth ring weld 34. The annular trajectory is set around the outer circumference of the head side cover plate 27 and the head blank 8. The welding power is 3500W, the welding speed is 20mm / s, and the laser defocusing amount is +5mm. Figure 28 As shown, the penetration depth of weld 34 in the thirteenth ring is 4.182 mm and the weld width is 3.408 mm.

[0130] S16: Using a fixture to clamp the entire assembly, laser welding is performed along the annular trajectory at the connection point between the connecting ring 31 and the body 29 to form the fourteenth ring weld 35. The annular trajectory is set around the outer circumference of the connecting ring 31 and the head blank 8. The welding power is 3000W, the welding speed is 25mm / s, and the laser defocusing amount is +5mm. Figure 29 and Figure 30 As shown, the penetration depth of weld 35 in the fourteenth ring is 3.419 mm and the weld width is 2.903 mm.

[0131] After welding, the finished igniter was tested and its pressure-bearing performance and airtightness both exceeded the test indicators. It did not deform under pressure and met the requirements of withstanding hydraulic pressure of 3~12MPa and air pressure of 3~5MPa. Example 2:

[0132] like Figure 1 and Figure 2 The image shows a preferred embodiment of the laser welding method for an engine igniter according to the present invention, the method comprising the following steps:

[0133] S1. Assemble the oxidizer nozzle 1 and the fuel nozzle 2: Insert one end of the oxidizer nozzle 1 into the fuel nozzle 2 until it makes contact at the limit position;

[0134] The oxidizer nozzle 1 and the fuel nozzle 2 are clamped and fixed using a three-jaw chuck;

[0135] Laser spot welding is performed along an annular trajectory at the connection between fuel nozzle 2 and oxidant nozzle 1. The annular trajectory is set around the outer circumference of fuel nozzle 2 and oxidant nozzle 1. Multiple spaced weld points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +2.2mm.

[0136] The first ring weld 3 is then formed by laser welding along the circular trajectory. The welding power is 750w, the welding speed is 30mm / s, the laser defocusing amount is -6mm, and the penetration depth of the first ring weld 3 is 1~1.3mm and the penetration width is 1.2~1.3mm.

[0137] S2. Assemble the auxiliary fuel nozzle 4 and the inner bottom 5: The auxiliary fuel nozzle 4 is assembled in the first mounting hole 6 of the inner bottom 5, and the thickness of the inner bottom 5 is 1mm.

[0138] Laser spot welding is performed along the annular trajectory connecting the auxiliary fuel nozzle 4 and the inner bottom 5. The annular trajectory is set around the outer circumference of the auxiliary fuel nozzle 4 and the first mounting hole 6. A welding point is set every 60° on the annular trajectory. Six spaced welding points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +1mm.

[0139] S3. Assemble the ignition nozzle 7, the fuel nozzle 2 and the oxidizer nozzle 1 from step S1 onto the inner bottom 5 and the head blank 8: First, use the ignition nozzle 7 to position and assemble the head blank 8 and the inner bottom 5. The ignition nozzle 7 is assembled in the second mounting hole 9 of the head blank 8 and the third mounting hole 10 of the inner bottom 5. The head blank 8 and the inner bottom 5 are in limited contact. Then, assemble the fuel nozzle 2 and the oxidizer nozzle 1 from step S1, so that the fuel nozzle 2 is assembled in the fourth mounting hole 11 of the inner bottom 5 and the oxidizer nozzle 1 is assembled in the fifth mounting hole 12 of the head blank 8.

[0140] Laser spot welding is performed along the annular trajectory at the connection between the ignition nozzle 7 and the inner bottom 5. The annular trajectory is set around the outer circumference of the ignition nozzle 7 and the third mounting hole 10. A welding point is set every 45° on the annular trajectory. Eight spaced welding points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +2mm.

[0141] Laser spot welding is performed along the annular trajectory connecting the fuel nozzle 2 and the inner bottom 5. The annular trajectory is set around the outer circumference of the fuel nozzle 2 and the fourth mounting hole 11. A welding point is set every 60° on the annular trajectory. Six spaced welding points are welded along the annular trajectory. The spot welding power is 200W and the laser defocusing amount is +2mm.

[0142] S4: Laser spot welding along the annular trajectory connecting the head blank 8 and the inner bottom 5. The annular trajectory is set around the outer circumference of the head blank 8 and the inner bottom 5. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 220W and the laser defocusing amount is +2mm.

[0143] Before laser welding, anti-spatter oil is applied, and then laser welding is performed along the circular trajectory to form the second ring weld 13. The welding power is 700w, the welding speed is 30mm / s, and the laser defocusing amount is +2.5mm. After laser welding, the anti-spatter oil is wiped off. The penetration depth of the second ring weld 13 is 2.0~2.2mm and the penetration width is 1.1~1.3mm.

[0144] S5: Laser welding is performed along the annular trajectory of the spot welding between the ignition nozzle 7 and the inner bottom 5 to form the third ring weld 14. The welding power is 400w, the welding speed is 40mm / s, the laser defocusing amount is +2.2mm, and the penetration depth of the third ring weld 14 is 0.8~0.9mm and the penetration width is 0.85~0.95mm.

[0145] S6: After the entire structure has cooled to room temperature, the fourth ring weld 15 is formed by laser welding along the circular trajectory of the laser spot welding between the auxiliary fuel nozzle 4 and the inner bottom 5. The welding power is 400w, the welding speed is 30mm / s, the laser defocusing amount is +2.2mm, and the penetration depth and width of the fourth ring weld 15 are 0.8~0.9mm and 0.8~0.9mm respectively.

[0146] S7: Laser welding is performed along the circular trajectory of spot welding between the fuel nozzle 2 and the inner bottom 5 to form the fifth ring weld 16. The welding power is 500w, the welding speed is 40mm / s, the laser defocusing amount is +3mm, and the penetration depth and width of the fifth ring weld 16 are 0.8~0.9mm and 0.8~0.9mm respectively.

[0147] S8: Laser welding is performed along the annular trajectory at the connection between the ignition nozzle 7 and the head blank 8 to form the sixth ring weld 17. The annular trajectory is set around the outer circumference of the ignition nozzle 7 and the second mounting hole 9. The welding power is 700w, the welding speed is 30mm / s, the laser defocusing amount is +1.5mm, and the penetration depth of the sixth ring weld 17 is 1.5~1.7mm and the penetration width is 1.1~1.3mm.

[0148] The seventh ring weld 18 is formed by laser welding along the annular trajectory at the connection between the oxidant nozzle 1 and the head blank 8. The annular trajectory is set around the outer circumference of the oxidant nozzle 1 and the fifth mounting hole 12. The welding power is 700w, the welding speed is 25mm / s, the laser defocusing amount is +2.2mm, and the penetration depth of the seventh ring weld 18 is 1.5~1.71mm and the penetration width is 1.1~1.3mm.

[0149] S9. Assemble the ignition nozzle 7 and the head cover plate 20: The ignition nozzle 7 is assembled in the sixth mounting hole 21 of the head cover plate 20.

[0150] The eighth ring weld 22 is formed by laser welding along the annular trajectory at the connection between the ignition nozzle 7 and the head cover plate 20. The annular trajectory is set along the outer circumference of the ignition nozzle 7 and the sixth mounting hole 21. The welding power is 750W, the welding speed is 35mm / s, the laser defocusing amount is +3mm, and the penetration depth of the eighth ring weld 22 is 1.3~1.5mm and the penetration width is 1.2~1.3mm.

[0151] S10: The ninth ring weld 26 is formed by laser welding along the trajectory at the connection between the support base 19 and the head cover plate 20. The welding trajectory is divided into four segments along the outer circumference of the support base 19 and the head cover plate 20, including two straight segments 23 on both sides and two arc segments 24 at the top and bottom. The welding trajectory overlaps by 15mm between adjacent segments. The welding power is 3200W, the welding speed is 25mm / s, the laser defocusing amount is -4mm, and coaxial air blowing and dual side-axis assisted air blowing are used. The penetration depth of the ninth ring weld 26 is 3.3~3.6mm and the penetration width is 2.9~3.1mm.

[0152] S11. Assemble the head side cover 27 and the head top cover 20: The head top cover 20 is assembled in the seventh mounting hole 28 of the head side cover 27.

[0153] Laser spot welding is performed along the annular trajectory at the connection between the head side cover plate 27 and the head top cover plate 20. The annular trajectory is set around the outer circumference of the head side cover plate 27 and the seventh mounting hole 28. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 1500W and the laser defocusing amount is +5mm.

[0154] S12: Laser spot welding along the annular trajectory connecting the body 29 and the inner bottom 5. The annular trajectory is set around the end of the body 29 and the outer circumference of the inner bottom 5. A welding point is set every 10° on the annular trajectory. 36 spaced welding points are welded along the annular trajectory. The spot welding power is 200W and the laser defocusing amount is +2mm.

[0155] Then, laser welding is performed along the circular trajectory to form the tenth ring weld 30. The welding power is 700W, the welding speed is 30mm / s, the laser defocusing amount is +1mm, and the penetration depth of the tenth ring weld 30 is 2.0~2.2mm and the penetration width is 1.1~1.3mm.

[0156] S13: A connecting ring 31 is assembled on the outside of the body 29 and the inner bottom 5. The connecting ring 31 consists of two arc-shaped connecting parts. An eleventh ring weld 32 is formed by laser welding along the annular trajectory at the connection between the connecting ring 31 and the head blank 8. The trajectory is an arc-shaped trajectory around the arc-shaped connecting parts and the outside of the head blank 8. The arc-shaped trajectory includes two segments with a welding length of 20°. Each arc-shaped connecting part and the head blank 8 are laser welded to form the eleventh ring weld 32. The welding power is 1600W, the welding speed is 20mm / s, the laser defocusing amount is -6mm, and the penetration depth of the eleventh ring weld 32 is 3.3~3.6mm and the penetration width is 2.9~3.1mm.

[0157] S14: The twelfth ring weld 33 is formed by laser welding along the annular trajectory of the laser spot welding between the head side cover plate 27 and the head top cover plate 20. The welding power is 3200W, the welding speed is 15mm / s, the laser defocusing amount is +4mm, and the penetration depth of the twelfth ring weld 33 is 4.1~4.4mm and the penetration width is 3.4~3.6mm.

[0158] S15: The whole assembly is held in a fixture, and the thirteenth ring weld 34 is formed by laser welding along the annular trajectory between the head side cover plate 27 and the head blank 8. The annular trajectory is set around the outer circumference of the head side cover plate 27 and the head blank 8. The welding power is 3200W, the welding speed is 15mm / s, the laser defocusing amount is +4mm, and the penetration depth of the thirteenth ring weld 34 is 4.1~4.4mm and the penetration width is 3.4~3.6mm.

[0159] S16: The whole assembly is held in a fixture, and the fourteenth ring weld 35 is formed by laser welding along the annular trajectory at the connection between the connecting ring 31 and the body 29. The annular trajectory is set around the outer circumference of the connecting ring 31 and the head blank 8. The welding power is 2800W, the welding speed is 15mm / s, the laser defocusing amount is +4mm, and the penetration depth of the fourteenth ring weld 35 is 3.3~3.6mm and the penetration width is 2.9~3.1mm.

[0160] After welding, the finished igniter was tested and its pressure-bearing performance and airtightness exceeded the test indicators. It did not deform under pressure and could withstand hydraulic pressure of 3~12MPa and air pressure of 3~5MPa.

[0161] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0162] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly, referring to direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.

[0163] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laser welding method for engine igniters, characterized in that, The methods include: S1: Assemble the oxidizer nozzle (1) and the fuel nozzle (2); After laser spot welding along the annular trajectory at the connection between the fuel nozzle (2) and the oxidant nozzle (1), laser welding is then performed along the annular trajectory to form the first annular weld (3). The penetration depth of the first annular weld (3) is 1~1.3mm and the penetration width is 1.2~1.3mm. S2: Assemble the auxiliary fuel nozzle (4) and the inner bottom (5); Laser spot welding is performed along the annular trajectory connecting the auxiliary fuel nozzle (4) and the inner bottom (5) on the opposite side; S3: Assemble the ignition nozzle (7), the fuel nozzle (2) from step S1, and the oxidizer nozzle (1) onto the inner bottom (5) and the head blank (8); Laser spot welding along the annular trajectory at the connection between the ignition nozzle (7) and the reverse side of the inner bottom (5); Laser spot welding along the annular trajectory where the fuel nozzle (2) connects to the reverse side of the inner bottom (5); S4: After laser spot welding along the annular trajectory connecting the head blank (8) and the inner bottom (5), laser welding is then performed along the annular trajectory to form a second annular weld (13). The penetration depth of the second annular weld (13) is 2.0~2.2mm and the penetration width is 1.1~1.3mm. S5: Laser welding along the annular trajectory of the spot welding between the ignition nozzle (7) and the inner bottom (5) forms a third ring weld (14), with a penetration depth of 0.8~0.9mm and a weld width of 0.85~0.95mm. S6: The fourth ring weld (15) is formed by laser welding along the annular trajectory of the laser spot welding between the auxiliary fuel nozzle (4) and the inner bottom (5). The penetration depth of the fourth ring weld (15) is 0.8~0.9mm and the penetration width is 0.8~0.9mm. S7: Laser welding along the annular trajectory of spot welding between the fuel nozzle (2) and the inner bottom (5) forms the fifth ring weld (16), with a penetration depth of 0.8~0.9mm and a weld width of 0.8~0.9mm. S8: Laser welding is performed along the annular trajectory at the connection between the ignition nozzle (7) and the head blank (8) to form the sixth ring weld (17). The penetration depth of the sixth ring weld (17) is 1.5~1.7mm and the penetration width is 1.1~1.3mm. The seventh ring weld (18) is formed by laser welding along the annular trajectory at the connection between the oxidant nozzle (1) and the head blank (8). The penetration depth of the seventh ring weld (18) is 1.5~1.71mm and the penetration width is 1.1~1.3mm.

2. The laser welding method for an engine igniter according to claim 1, characterized in that, In step S1, during assembly, one end of the oxidant nozzle (1) is inserted into the fuel nozzle (2) until it makes contact with the limit position; When spot welding the oxidant nozzle (1) and the fuel nozzle (2) with laser, the annular trajectory is set around the outer circumference of the fuel nozzle (2) and the oxidant nozzle (1), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +0.5~+2.2mm. When laser welding the first ring weld (3), the welding power is 600~800w, the welding speed is 30~50mm / s, and the laser defocusing amount is -8~-4mm.

3. The laser welding method for an engine igniter according to claim 1, characterized in that, In step S2, during assembly, the auxiliary fuel nozzle (4) is assembled in the first mounting hole (6) of the inner bottom (5); When spot welding the auxiliary fuel nozzle (4) and the inner bottom (5) with laser, the annular trajectory is set around the outer circumference of the auxiliary fuel nozzle (4) and the first mounting hole (6), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W, and the laser defocusing amount is +0.5~1.5mm. In step S6, before laser welding of the fourth ring weld (15): the whole is cooled to room temperature. During laser welding: welding power 400~500w, welding speed 30~40mm / s, laser defocusing amount is +2~3mm.

4. The laser welding method for an engine igniter according to claim 1, characterized in that, In step S3, during assembly, the ignition nozzle (7) is assembled in the second mounting hole (9) of the head blank (8) and the third mounting hole (10) of the inner bottom (5), and the head blank (8) and the inner bottom (5) are in limiting contact. When the laser spot welds the ignition nozzle (7) and the inner bottom (5), the annular trajectory is set around the outer circumference of the ignition nozzle (7) and the third mounting hole (10), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W and the laser defocusing amount is +1~2mm. In step S5, when the third ring weld (14) is laser welded, the welding power is 400~550w, the welding speed is 25~40mm / s, and the laser defocusing amount is +2~4.5mm. In step S8, when the sixth ring weld (17) is laser welded, the ring trajectory is set around the outer circumference of the ignition nozzle (7) and the second mounting hole (9), the welding power is 700~850w, the welding speed is 25~35mm / s, and the laser defocusing amount is +1~3mm.

5. The laser welding method for an engine igniter according to claim 1, characterized in that, In step S3, during assembly, the fuel nozzle (2) is assembled in the fourth mounting hole (11) of the inner bottom (5); the oxidizer nozzle (1) is assembled in the fifth mounting hole (12) of the head blank (8); When spot welding the fuel nozzle (2) and the inner bottom (5) with laser, the annular trajectory is set around the outer circumference of the fuel nozzle (2) and the fourth mounting hole (11), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W and the laser defocusing amount is +1~2mm. In step S7, when laser welding the fifth ring weld (16): the welding power is 350~450w, the welding speed is 30~40mm / s, and the laser defocusing amount is +2~3mm; In step S8, when the seventh ring weld (18) is laser welded, the annular trajectory is set around the outer circumference of the oxidant nozzle (1) and the fifth mounting hole (12), the welding power is 700~850w, the welding speed is 25~35mm / s, and the laser defocusing amount is +1~3mm.

6. The laser welding method for an engine igniter according to claim 1, characterized in that, In step S4, when the head blank (8) and the inner bottom (5) are laser spot welded, the annular trajectory is set around the outer circumference of the head blank (8) and the inner bottom (5), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W and the laser defocusing amount is +1~2mm. Before laser welding of the second ring weld (13): apply anti-spatter oil; during laser welding: welding power 700~750w, welding speed 30~50mm / s, laser defocusing amount +0.5~2.5mm; after laser welding: remove anti-spatter oil.

7. A laser welding method for an engine igniter according to any one of claims 1 to 6, characterized in that, include: S9: Assemble the ignition nozzle (7) and the head cover plate (20). The eighth ring weld (22) is formed by laser welding along the annular trajectory at the connection between the ignition nozzle (7) and the head cover plate (20). The penetration depth of the eighth ring weld (22) is 1.3~1.5mm and the penetration width is 1.2~1.3mm. S10: Laser welding is used to form a ninth ring weld (26) along the trajectory of the connection between the support base (19) and the head cover plate (20). The penetration depth of the ninth ring weld (26) is 3.3~3.6mm and the penetration width is 2.9~3.1mm. S11: Assemble the head side cover (27) and the head top cover (20). Laser spot welding along the annular trajectory at the connection between the head side cover plate (27) and the head top cover plate (20); S12: Laser spot welding along the annular trajectory at the connection between the body (29) and the inner bottom (5), and then laser welding along the annular trajectory to form the tenth ring weld (30). The penetration depth of the tenth ring weld (30) is 2.0~2.2mm and the penetration width is 1.1~1.3mm. S13: A connecting ring (31) is assembled on the outside of the body (29) and the inner bottom (5). An eleventh ring weld (32) is formed by laser welding along the annular trajectory at the connection between the connecting ring (31) and the head blank (8). The eleventh ring weld (32) has a penetration depth of 3.3~3.6 mm and a penetration width of 2.9~3.1 mm. S14: The twelfth ring weld (33) is formed by laser welding along the circular trajectory of the laser spot welding between the head side cover plate (27) and the head top cover plate (20). The penetration depth of the twelfth ring weld (33) is 4.1~4.4mm and the penetration width is 3.4~3.6mm. S15: Laser welding along the annular trajectory between the head side cover plate (27) and the head blank (8) forms the thirteenth ring weld (34), with a penetration depth of 4.1~4.4mm and a penetration width of 3.4~3.6mm. S16: Laser welding is performed along the annular trajectory at the connection between the connecting ring (31) and the body (29) to form the fourteenth ring weld (35), with a penetration depth of 3.3~3.6mm and a penetration width of 2.9~3.1mm.

8. The laser welding method for an engine igniter according to claim 7, characterized in that, In step S9, during assembly: the ignition nozzle (7) is assembled into the sixth mounting hole (21) of the head cover plate (20). When laser welding the eighth ring weld (22), the ring trajectory is set along the outer circumference of the ignition nozzle (7) and the sixth mounting hole (21), the welding power is 650~750W, the welding speed is 25~35mm / s, and the laser defocusing amount is +2~+4mm. In step S10, when the ninth ring weld (26) is laser welded, the outer circumference of the support base (19) and the head cover plate (20) is divided into several welding tracks, the adjacent welding tracks overlap by 10~15mm, the welding power is 2900~3200W, the welding speed is 15~25mm / s, and the laser defocusing amount is -6~-3mm. In step S11, during assembly, the head cover plate (20) is assembled in the seventh mounting hole (28) of the head side cover plate (27); When laser spot welding the head side cover plate (27) and the head top cover plate (20), the annular trajectory is set around the outer circumference of the head side cover plate (27) and the seventh mounting hole (28), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 1200~1500W, and the laser defocusing amount is +2~+5mm. In step S14, when welding the twelfth ring weld (33), the welding power is 3200~3800W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm. In step S15, when welding the thirteenth ring weld (34), the ring trajectory is set around the outer circumference of the head side cover plate (27) and the head blank (8), the welding power is 3200~3800W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm.

9. A laser welding method for an engine igniter according to claim 7, characterized in that, In step S12, when the laser spot welds the body (29) and the inner bottom (5), the annular trajectory is set around the end of the body (29) and the outer circumference of the inner bottom (5), and multiple spaced welding points are welded along the annular trajectory. The spot welding power is 180~220W and the laser defocusing amount is +2mm. When laser welding the tenth ring weld (30), the welding power is 700~850W, the welding speed is 30~50mm / s, and the laser defocusing amount is +0.5~2.5mm.

10. A laser welding method for an engine igniter according to claim 7, characterized in that, In step S13, the connecting ring (31) is composed of multiple arc-shaped connectors. When the eleventh ring weld (32) is laser welded, the trajectory is an arc-shaped trajectory around the arc-shaped connector and the head blank (8). The arc-shaped connector and the head blank (8) are laser welded in multiple segments to form the eleventh ring weld (32). The welding power is 1400~1600W, the welding speed is 15~30mm / s, and the laser defocusing amount is -6~-2mm. In step S16, when welding the fourteenth ring weld (35), the ring trajectory is set around the outer circumference of the connecting ring (31) and the head blank (8), the welding power is 2800~3000W, the welding speed is 15~25mm / s, and the laser defocusing amount is +4~+6mm.

Images