CN107245715B - A built-in sieve ring laser cladding nozzle - Google Patents

Abstract

The invention discloses a kind of built-in sieve mesh type loop laser melting-painting nozzles, including laser head coupling part, middle part sleeve part and nozzle segment, laser head coupling part includes the upper joint sleeve cylinder being connected with laser head, middle part sleeve part includes the sliding sleeve being connected with upper joint sleeve cylinder, protection glass is equipped between sliding sleeve lower end and cylindrical central sleeve upper end, protect glass water-cooled jacket respectively with sliding sleeve, cylindrical central sleeve is threadedly coupled, protection gas stomata is equipped in cylindrical central sleeve, nozzle segment includes the conical nozzle core being connected with cylindrical central sleeve, it is successively arranged on the outside of conical nozzle core and cylindrical central sleeve into powder set, air inlet set, water-cooled jacket.The present invention overcomes service lifes existing for existing laser melting-painting nozzle, and short, powder convergence diameter can not adjust, can not adapt to the shortcomings that different sized powders particles.

Description

A built-in sieve ring laser cladding nozzle

technical field

The invention relates to the technical field of laser processing, in particular to an annular coaxial laser cladding nozzle.

Background technique

Laser cladding technology is a new surface modification technology. It is a process method that fuses two or more materials with different properties by heating them together to give full play to their excellent properties. Laser cladding has the characteristics of fast heating and cooling speed, and the obtained cladding layer has fine microstructure, high strength, and its performance is obviously better than other cladding methods, so it has attracted extensive attention from material workers all over the world.

The design of powder feeding nozzle for laser cladding is a key technology in laser processing equipment. The function of the powder feeding nozzle is to transform the powder flow from the powder feeder into different shapes and enter the laser beam, which plays a role in controlling the injection angle and cross-sectional size of the powder flow. The structure and performance of the nozzle directly affect the cladding The effect of the process and the precision and quality of the formed parts. In-depth research on coaxial powder feeding nozzles has been carried out at home and abroad, and certain results have been achieved, but there are still many deficiencies, as follows: (1) In the absence of protective gas, the outlet of the powder feeding pipe is easy Clogging, which tends to cause the powder to flow out of the laser beam before reaching the substrate surface, creates areas where the cladding material is non-metallurgically bonded to the substrate. (2) The amount of powder feeding is uneven. During the implementation of the coaxial powder feeding laser cladding process, the flow of the cladding material in the laser beam is divergent, causing the powder spot diameter to exceed the laser spot diameter, and the powder beyond the laser spot diameter range is not fully heated in the laser beam. It will cause the cladding powder and the substrate surface to fail to form a metallurgical bond, which will directly lead to the deterioration of the surface of the formed part, and even lead to collapse in severe cases, making the forming process unable to continue. (3) The powder feeding nozzle cannot realize the precise coaxiality adjustment of the powder and the laser beam, resulting in the coaxial work of the powder spot and the laser beam. (4) The laser beam will reflect on the surface of the substrate, resulting in energy loss. In severe cases, the reflected laser beam may burn the nozzle. (5) The water-cooling pipeline cannot completely cool the lower end of the nozzle, causing the place close to the molten pool to be easily damaged by radiant heat. (6) The protective mirror glass cannot be completely cooled, and local overheating may easily cause the glass to break.

At present, there are mainly two types of coaxial powder feeding nozzles used in laser cladding forming: three-beam coaxial powder feeding nozzles and annular coaxial powder feeding nozzles. The three-beam coaxial powder feeding nozzle has three powder feeding channels symmetrically distributed with the laser beam as the axis. The inner diameter of the channel is 1~3mm. Under certain conditions, thicker and wider cladding layers are processed, as well as 3D cladding with larger inclination angle requirements. The annular coaxial powder feeding nozzle guides the powder particles through a conical gap to form an annular powder flow centered on the laser beam, which converges and enters the molten pool. This structural design can make the powder aggregation spot less than 0.4mm, that is, it can also obtain extremely high cladding efficiency for ultra-narrow cladding layers with a width of less than 1mm.

In Chinese patent CN104694922A, a coaxial powder feeding nozzle is proposed, the main parts of which are connected by bolts. The size and quantity of the powder outlet are not easy to adjust. Moreover, it does not adopt a cooling device near the molten pool of the nozzle, which is more likely to cause the nozzle to be damaged by radiant heat and reduce the service life of the nozzle. U.S. Patent No. 5,477,026 proposes a multi-layer annular cone nozzle, which adopts a modular structure, which is convenient for replacing parts, and there is a large space for powder to enter the powder pipe, which can play a steady flow effect. The main disadvantage is that the uniformity of the powder flow at the outlet of the nozzle is poor, and the powder is easy to melt and block the powder outlet at the outlet at the bottom end, and secondly, the nozzle cannot adjust the diameter of the powder convergence.

Contents of the invention

Purpose of the invention: In order to solve the above problems, the present invention aims to provide a built-in sieve ring laser cladding nozzle with long service life, adjustable powder convergence diameter, and suitable for powder particles of different sizes.

In order to achieve the above object, the present invention adopts the following technical solution: a built-in sieve ring laser cladding nozzle, including a laser head connection part, a middle sleeve part and a nozzle part; the laser head connection part includes an upper connection sleeve The upper end of the upper connecting sleeve is connected with the laser head; the middle sleeve part includes a sliding sleeve, a protective glass water cooling sleeve, a central sleeve, and a protective glass. The upper end of the sliding sleeve is connected with the lower end of the upper connecting sleeve, and the sliding sleeve There is a protective glass between the lower end and the upper end of the central sleeve, and a protective glass water-cooling sleeve is provided between the lower end of the sliding sleeve and the upper end of the central sleeve. There is a middle water inlet nozzle and a middle water outlet nozzle on the top, and two opposite protective gas holes are arranged at the position of the central sleeve close to the protective glass, and the lower end of the central sleeve is tapered; the nozzle part includes a conical nozzle core, The powder inlet sleeve, the air inlet sleeve, the water cooling sleeve, the annular sieve plate, the upper end of the conical nozzle core and the lower end of the central sleeve are connected through thread fit, and the powder inlet sleeve, the inlet The air jacket, water cooling jacket, powder inlet jacket, inlet jacket, and water cooling jacket are all cylindrical in the upper half, and the lower half is conical. There is a powder inlet nozzle at the upper end, an annular sieve plate is arranged between the lower end of the powder inlet sleeve and the lower end of the central sleeve, and a small powder outlet hole is arranged on the annular sieve plate, and the upper end of the air inlet sleeve and the upper end of the powder inlet sleeve are connected by thread fit , the upper end of the air intake sleeve is provided with an air intake nozzle, the upper end of the water cooling sleeve and the upper end of the air intake sleeve are fixed by welding, the upper end of the water cooling sleeve is provided with an upper water outlet, and the lower end of the water cooling sleeve is provided with a lower water inlet nozzle and an arc-shaped baffle.

Further, the upper end of the sliding sleeve extends into the connecting sleeve and can slide up and down along the connecting sleeve, and a plurality of screw holes are uniformly distributed on the outer circle of the lower end of the connecting sleeve, and centering screws are inserted into the screw holes, and through the centering The screw clamps the sliding sleeve and keeps the sliding sleeve concentric with the upper connecting sleeve.

Further, a sealing ring is provided between the outer circle of the protective glass and the water-cooling jacket of the protective glass.

Further, the inner surface of the upper end of the conical nozzle core and the inner surface of the lower end of the central sleeve smoothly transition, and there is an annular gap between the outer edge of the upper end of the conical nozzle core and the outer edge of the lower end of the central sleeve, and the annular The edge part of the inner ring of the sieve plate is snapped into the annular notch.

Further, a plurality of staggered flow guide baffles are arranged between the water cooling jacket and the air inlet jacket from top to bottom.

Further, multiple powder inlet nozzles and air inlet nozzles are arranged around the central sleeve.

Further, the number of the powder inlet nozzle and the air inlet nozzle are the same and their positions correspond to each other.

Further, the diameter of the small powder outlet hole is greater than or equal to 0.2mm and less than or equal to 3mm.

Compared with the existing laser cladding nozzle equipment, the present invention has the following advantages:

(1) The size and quantity of the powder outlet can be adjusted, and the diameter of the powder convergence can be adjusted to achieve good powder-light matching;

(2) While the nozzle core is protected by increasing the distance from the molten pool, it also provides measures for easy replacement;

(3) Improve the cooling method of the existing protective glass.

(4) The concentricity between the sliding sleeve 3 and the upper connecting sleeve 1 is ensured by the centering screw 2, which avoids the concentricity error caused by processing and installation;

(5) It is suitable for powder particles of any size, and at the same time improves the aggregation, stability and powder utilization of the powder.

(6) Optimize the water cooling channel, reduce water consumption and avoid mutual entanglement caused by too many pipelines.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic diagram of the layout of the powder outlet holes on the annular sieve plate;

In the figure: 1. Upper connecting sleeve; 2. Centering screw; 3. Sliding sleeve; 4. Protective glass water cooling jacket; 5. Water inlet in the middle; 6. Powder inlet; 7. Air inlet; 8. Upper water nozzle; 9. Powder inlet sleeve; 10. Air intake sleeve; 11. Water cooling jacket; 12. Guide baffle; 13. Lower water inlet; 14. Conical nozzle core; 1. Central sleeve; 17. Protective air hole; 18. Middle spout; 19. Seal ring; 20. Protective glass; 21. Small hole for powder outlet;

Detailed ways:

The present invention will be further explained below in conjunction with the accompanying drawings.

As shown in Figure 1, a built-in mesh ring laser cladding nozzle of the present invention includes a laser head connection part, a middle sleeve part and a nozzle part.

The laser head connection part includes an upper connection sleeve 1, the upper end of the upper connection sleeve 1 is connected with the laser head, and the laser cladding nozzle of the present invention is connected with the laser equipment through the upper connection sleeve 1.

The middle sleeve part includes a sliding sleeve 3 , a protective glass water cooling jacket 4 , a central sleeve 16 and a protective glass 20 . The upper end of the sliding sleeve 3 is connected to the lower end of the upper connecting sleeve 1. In this embodiment, the upper end of the sliding sleeve 3 extends into the connecting sleeve 1 and can slide up and down along the connecting sleeve 1. A plurality of screw holes are evenly distributed in the circle, and the centering screw 2 is penetrated into the screw hole, and the sliding sleeve 3 is clamped by the centering screw 2 and the sliding sleeve 3 is kept concentric with the upper connecting sleeve 1 . A protective glass 20 is provided between the lower end of the sliding sleeve 3 and the upper end of the central sleeve 16, and a protective glass water cooling jacket 4 is provided outside the lower end of the sliding sleeve 3 and the upper end of the central sleeve 16, and the protective glass water cooling jacket 4 is connected to the sliding sleeve 3 respectively. , the central sleeve 16 is threaded, and a sealing ring 19 is provided between the outer circle of the protective glass 20 and the protective glass water cooling jacket 4, and the middle water inlet nozzle 5 and the middle water outlet nozzle 18 are arranged on the protective glass water cooling jacket 4. The position of the cylinder 16 close to the protective glass 20 is provided with two opposite protective air holes 17, and the lower end of the central sleeve 16 is tapered.

The nozzle part includes a conical nozzle core 14 , a powder inlet sleeve 9 , an air inlet sleeve 10 , a water cooling jacket 11 , and an annular sieve plate 15 . The upper end of the conical nozzle core 14 and the lower end of the central sleeve 16 are threadedly connected, and a powder inlet sleeve 9, an air inlet sleeve 10, and a water cooling sleeve 11 are sequentially arranged outside the conical nozzle core 14 and the lower end of the central sleeve 16. The first half of the powder inlet cover 9, the air intake cover 10 and the water cooling cover 11 are cylindrical, and the lower half is conical. The upper end of the powder inlet sleeve 9 is connected with the central sleeve 16 through thread fit, the upper end of the powder inlet sleeve 9 is provided with a powder inlet nozzle 6, and an annular sieve plate 15 is arranged between the lower end of the powder inlet sleeve 9 and the lower end of the central sleeve 16. The annular sieve plate 15 is provided with a plurality of powder outlet holes 21, as shown in Figure 2, the diameter of the powder outlet holes 21 is greater than or equal to 0.2mm and less than or equal to 3mm, the number of powder outlet holes 21 can be adjusted according to the powder feeding Optimize and adjust parameters such as volume and powder feeding speed. The upper end of the air inlet sleeve 10 is threadedly connected with the upper end of the powder inlet sleeve 9. A plurality of air inlet nozzles 7 are arranged around the central sleeve 16 at the upper end of the air inlet sleeve 10. The upper end of the water cooling sleeve 11 and the upper end of the air inlet sleeve 10 are fixed by welding. Surrounding the central sleeve 16 at the upper end of the water-cooling jacket 11, there are upper water outlet nozzles 8 having the same number as the air inlet nozzles 7 and one-to-one corresponding positions. Between the water cooling jacket 11 and the air inlet jacket 10, a plurality of staggered flow guide baffles 12 are arranged from top to bottom. In this embodiment, the inner surface of the upper end of the conical nozzle core 14 and the inner surface of the lower end of the central sleeve 16 transition smoothly, and there is a gap between the outer edge of the upper end of the conical nozzle core 14 and the outer edge of the lower end of the central sleeve 16. An annular notch, the edge of the inner ring of the annular sieve plate 15 is snapped into the annular notch, and the annular sieve plate 15 is clamped by the tapered nozzle core 14 and the central sleeve 16 .

When the laser cladding nozzle is working, the adjustment of the coaxiality between the laser beam and the powder flow is realized through the centering screw 2 . Since the air inlet sleeve 10 and the powder inlet sleeve 9 are connected by threaded discs, the air inlet sleeve 10 can be adjusted up and down within a certain distance relative to the powder inlet sleeve 9, so that the lower end of the air inlet sleeve 10 and the conical powder inlet sleeve can be adjusted. 9 The angle between the lower ends, and then change the airflow angle, so as to realize the control of the size of the powder spots. The lower end of the water cooling jacket 11 is provided with an arc-shaped baffle 22, which can re-reflect the laser beam reflected from the substrate, which greatly improves the utilization rate of the laser beam energy.

The distance between the nozzle part and the molten pool can be adjusted by sliding the sleeve 3, and the tapered nozzle core 14 is detachably connected with the central sleeve 16 through threaded connection, which facilitates the replacement of annular sieve plates 15 with different apertures. Since the inner wall of the conical nozzle core 14 is a smooth curved surface, the powder splashed inside the conical nozzle core 14 can slide down by itself, which avoids blocking the powder outlet and improves the utilization rate of the powder.

In order to prevent the protective glass 20 from overheating, cooling water can be passed into the protective glass water cooling jacket 4 to cool the outer edge of the protective glass 20. There are two protective gas holes 17 below the protective glass 20, and the protective gas 20 can be cooled by introducing protective gas. The center is air-cooled, and the outer edge of the protective glass 20 is wrapped with a sealing ring 19, which can ensure the air pressure in the cavity of the central sleeve 16 and prevent the powder from rising and polluting the protective glass. In order to prevent local overheating of the nozzle part, forced water cooling is realized by passing cooling water into the water cooling jacket 11 . Cooling water flows in from the middle water inlet nozzle 5 of the protective glass water cooling jacket 4, then flows out from the middle water outlet nozzle 18, and the flowing cooling water enters the water cooling jacket 11 through the lower water inlet nozzle 13, and finally flows out from the upper water outlet nozzle 8. The cooling water is cooled according to the above path, which can not only reduce water consumption but also avoid mutual entanglement caused by too many pipelines.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (8)

1. A built-in sieve-type annular laser cladding nozzle, characterized in that: it includes a laser head connection part, a middle sleeve part and a nozzle part; the laser head connection part includes an upper connection sleeve (1), an upper connection sleeve The upper end of the cylinder (1) is connected with the laser head; the middle sleeve part includes a sliding sleeve (3), a protective glass water cooling jacket (4), a central sleeve (16), a protective glass (20), a sliding sleeve (3 ) upper end is connected with the lower end of the upper connecting sleeve (1), a protective glass (20) is provided between the lower end of the sliding sleeve (3) and the upper end of the central sleeve (16), and the lower end of the sliding sleeve (3) is connected with the central sleeve ( 16) There is a protective glass water-cooling jacket (4) on the outer side of the upper end, and the protective glass water-cooling jacket (4) is threadedly connected with the sliding sleeve (3) and the central sleeve (16) respectively, and the protective glass water-cooling jacket (4) is provided with a middle part The water inlet nozzle (5) and the middle water outlet nozzle (18) are provided with two protective air holes (17) opposite to each other at the position of the central sleeve (16) close to the protective glass (20), and the lower end of the central sleeve (16) It is conical; the nozzle part includes a conical nozzle core (14), a powder inlet sleeve (9), an air inlet sleeve (10), a water cooling jacket (11), an annular sieve plate (15), a conical nozzle core ( 14) The upper end and the lower end of the central sleeve (16) are threadedly connected, and a powder inlet sleeve (9), an air inlet sleeve (10), The water cooling jacket (11), the upper half of the powder inlet jacket (9), the air inlet jacket (10), and the water cooling jacket (11) are all cylindrical, and the lower half is conical, and the upper end of the powder inlet jacket (9) is It is connected with the center sleeve (16) through threads, the upper end of the powder inlet sleeve (9) is provided with a powder inlet nozzle (6), and the lower end of the powder inlet sleeve (9) and the lower end of the center sleeve (16) is provided with an annular sieve hole plate (15), the annular sieve plate (15) is provided with a small hole for powder outlet (21), the upper end of the air inlet cover (10) is connected with the upper end of the powder inlet cover (9) by thread fit, and the air inlet cover (10) can be Relative to the powder inlet sleeve (9), it can be adjusted up and down within a certain distance, so that the angle between the lower end of the inlet sleeve (10) and the lower end of the conical powder inlet sleeve (9) can be adjusted, thereby changing the airflow angle, thereby realizing the To control the size of powder spots, the upper end of the air intake sleeve (10) is provided with an air intake nozzle (7), the upper end of the water cooling sleeve (11) and the upper end of the air intake sleeve (10) are fixed by welding, and the upper end of the water cooling sleeve (11) is provided with an upper water outlet Mouth (8), water cooling jacket (11) lower end is provided with lower water inlet nozzle (13) and arc baffle plate (22). 2. A built-in sieve ring laser cladding nozzle according to claim 1, characterized in that: the upper end of the sliding sleeve (3) extends into the connecting sleeve (1) and can be moved along the connecting sleeve ( 1) Slide up and down, a plurality of screw holes are evenly distributed on the outer circle of the lower end of the connecting sleeve (1), and the centering screw (2) is inserted into the screw hole, and the sliding sleeve (3) is clamped by the centering screw (2) and Keep the sliding sleeve (3) concentric with the upper connecting sleeve (1). 3. A built-in sieve-type annular laser cladding nozzle according to claim 1, characterized in that a sealing ring (19) is provided between the outer circle of the protective glass (20) and the protective glass water cooling jacket (4) ). 4. A built-in sieve-type annular laser cladding nozzle according to claim 1, characterized in that: the inner surface of the upper end of the tapered nozzle core (14) and the inner surface of the lower end of the central sleeve (16) are smooth Transition, there is an annular notch between the outer edge of the upper end of the conical nozzle core (14) and the outer edge of the lower end of the central sleeve (16), and the edge of the inner ring of the annular sieve plate (15) is snapped into the annular notch Inside. 5. A built-in sieve ring laser cladding nozzle according to claim 1, characterized in that: between the water cooling jacket (11) and the air inlet jacket (10) there are multiple mutual Staggered deflector baffles (12). 6. A built-in sieve-type annular laser cladding nozzle according to claim 1, characterized in that: the powder inlet nozzle (6) and the air inlet nozzle (7) are arranged around the central sleeve (16). indivual. 7 . The built-in sieve ring laser cladding nozzle according to claim 6 , characterized in that: the number of the powder inlet nozzle ( 6 ) and the air inlet nozzle ( 7 ) are the same and their positions correspond to each other. 8. The built-in sieve ring laser cladding nozzle according to claim 1, characterized in that: the diameter of the small powder outlet hole (21) is greater than or equal to 0.2mm and less than or equal to 3mm.