CN1139455C - Adjustable wide-band bidirectional symmetrical powder-feeding laser melting-painting nozzle - Google Patents

Abstract

The invention belongs to the technical field of laser material processing, and relates to an adjustable broadband bidirectional symmetrical powder feeding laser cladding nozzle. It consists of an upper body and a lower body that are connected to each other; the lower body includes an outer cone coaxially arranged, a middle rectangular body, a lower rectangular cone, a replaceable rectangular nozzle, and a set of rectangular wide-band powder feeding heads and cooling water channels. It consists of two sets of powder feeding seats; the middle rectangular body is set between the outer cone and the lower rectangular body, and extends downward to connect with the replaceable rectangular nozzle. The two groups of powder feeding seats are symmetrically installed on the lower part of the outer cone and outside the replaceable rectangular nozzle. on both sides. The invention has the advantages of practicality, multi-performance and convenient use, and is especially suitable for wide application fields such as large-area powder feeding laser cladding.

Description

Adjustable broadband bidirectional symmetrical powder feeding laser cladding nozzle

Technical Field The present invention belongs to the technical field of laser material processing, and in particular relates to the structural design of a wide-band powder feeding nozzle for large-area laser cladding.

Background technology Laser processing is a new type of processing method using high-energy laser beams, and is an advanced material processing method in the contemporary era. Laser processing has many obvious advantages over conventional processing methods, and its application range is also very wide, such as: laser surface treatment (laser phase transformation hardening, laser remelting, laser alloying, laser cladding, laser microprocessing, laser surface roughening, etc.) Chemical), laser welding, laser cutting, laser drilling, laser marking, laser micromachining, etc. Laser cladding is a new method of using high-energy laser beams to obtain high-performance coatings on the surface of metal materials. It refers to adding metal elements or alloys while the laser beam melts the local surface of the material to change the surface microstructure of the material and change its composition. Coating method, the coating material has its own metallurgical system, and forms a thin-layer metallurgical bond with the substrate. The substrate has little dilution of the coating, which can achieve excellent surface wear resistance, corrosion resistance, erosion resistance, fatigue resistance, and high temperature oxidation resistance. , anti-friction and other properties; the heat input of the laser cladding process is small, the thermal cycle is very short, the thermal damage and thermal deformation to the substrate are less, and the composition, concentration, shape and area size of the cladding area can be controlled. The overall performance of the laser cladding layer is significantly better than that of conventional thermal spraying, plasma spraying, surfacing and other coatings, so it can be widely used in the strengthening and repairing of molds, the strengthening and repairing of valves and valves, the strengthening and repairing of metallurgical rolls, Strengthening and repairing of blades, strengthening and repairing of precious shaft parts, strengthening and repairing of large precious parts, partial repair of large precious castings, key friction pairs of motor vehicles (cylinder liners, piston rings, cams, crankshafts, tappets, valves etc.), strengthening and repairing of key parts of mining machinery, various pumps, compressors, blower parts, power plant parts, paper and cardboard production equipment, textile machinery and other fields, can significantly increase the use of parts The service life is improved, the performance of parts is improved, and the economic benefits are obvious.

The inventor has invented "vertical loading and unloading split type laser cladding coaxial powder feeding nozzle" (application number 00100041.1, publication number CN 1255411A) in this field. The outer cone, the cooling water baffle and the nozzle form a multi-layer concentric cone, including a coaxial optical path channel, a powder path channel, a protective gas channel and a cooling water channel. The powder channel is composed of a middle cone and an outer cone. The upper part of the outer cone contains four tangential inlets to introduce powder, and a microporous sieve is placed under the tangential inlets. The four-way powder flow entering the powder channel is quickly dispersed on the circumferential surface of the sieve ring driven by the conveying gas, and then leaks down evenly from dozens of micropores uniformly distributed on the circumference of the sieve ring, and flows along the powder channel to the After downward movement and aggregation, a uniform converging coaxial powder cone flow is formed at the exit, which makes the laser cladding isotropic and overcomes a series of shortcomings such as the anisotropy of single-tube lateral powder feeding and cladding. The invention has the advantages of simultaneous cooling of three layers of cones, flexible and convenient vertical loading and unloading, active uniformization of powder flow, flexible adjustment of spot diameter, replaceable inner cone head, anti-laser reflection at the end and powder recovery, etc., and is suitable for single-channel laser Cladding and laser rapid manufacturing, laser alloying, laser phase transformation hardening and laser welding and other occasions with converging narrow beams.

The width of a single cladding layer in laser cladding is often narrow, generally no more than 5mm. In order to achieve a larger cladding area, multiple transverse laps are required, and the lap rate generally does not exceed 30%. Since the laser cladding layer is often semi-elliptical, the surface smoothness, cladding efficiency and overall performance uniformity of the coating will be affected to a certain extent when multiple layers are overlapped. Therefore, under the conditions of sufficient laser power and broadened linear beam (the laser outputs a circular beam, there are many ways to convert it into a linear or rectangular wide beam, such as integrating mirrors, combined environments, scanning mirrors, binary optical elements, etc.), The use of broadband laser cladding can significantly improve the smoothness, performance uniformity and cladding efficiency of the cladding layer. Broadband powder feeding requires a broadband nozzle with good performance. However, the existing broadband nozzle simply uses a thin iron duck-shaped nozzle. During use, the nozzle will often be deformed and burned, powder clogged, powder uniformity is poor, and it cannot work for a long time. A series of problems make it difficult to meet the requirements of use.

SUMMARY OF THE INVENTION The purpose of the present invention is to overcome the deficiencies of the existing broadband cladding technology, and design a broadband bidirectional symmetrical powder feeding laser cladding nozzle, which has flexible and convenient vertical loading and unloading, bidirectional simultaneous broadband powder feeding, key Effective cooling of components, long-term stable work, stepless adjustment of defocus, step-by-step adjustment of powder feeding width, applicable to a variety of focal lengths of focusing lenses, etc., have the advantages of practicality, multi-performance, and convenient use, and are especially suitable for It is widely used in large-area powder-feeding laser cladding, large-area powder-feeding laser alloying, large-area preset powder laser cladding, large-area preset powder laser alloying, large-area laser remelting, and large-area laser phase transformation hardening. application field.

An adjustable broadband bidirectional symmetrical powder-feeding laser cladding nozzle proposed by the present invention is composed of an upper body and a lower body connected to each other; It consists of a rectangular cone, a replaceable rectangular nozzle, and two sets of powder feeding seats composed of an array of broadband powder feeding heads and a cooling water chamber; wherein, the middle rectangular body is set between the outer cone and the middle rectangular body, and downwards The extension is connected to the replaceable rectangular nozzle, and the two groups of powder feeding seats are symmetrically installed on the lower part of the outer cone and on both sides of the outside of the replaceable rectangular nozzle;

The inside of the powder feeding seat is a wedge-shaped cavity, and the inside of the rectangular wide-band powder feeding head is a fan-shaped structure, and its outlets have different widths. The cavity of the powder seat is in close contact, and the cooling water chamber is arranged outside the cavity of the powder feeding seat.

A cavity is formed between the outer cone and the lower rectangular cone, and the cavity is an internal cooling water channel; a rectangular slot wedge is formed between the middle rectangular body and the lower rectangular cone, and the slot wedge is an axial A protective gas channel; the center of the middle rectangular body is a rectangular cone cavity, and the rectangular cone cavity is an optical path channel.

The replaceable rectangular nozzle and the lower ends of the powder feeding seats on both sides form a reverse cone structure at the end of the nozzle.

Said upper body can be composed of an externally threaded sleeve, an internally threaded sleeve set inside it and an adjusting threaded cylinder arranged in the middle of the internally and externally threaded sleeve; the externally threaded sleeve is the connecting piece between the entire nozzle and the laser processing working head , the externally threaded sleeve, the internally threaded sleeve and the adjusting threaded cylinder form a vertically up and down directional defocus adjustment mechanism.

Can adopt buckle flap to connect between said upper and lower body, the buckle of this buckle flap is fixed on the lower end of threaded sleeve in the upper body, and flap is fixed on the lower external garden cone.

There can be a boss at the lower end of the inner threaded sleeve in said upper body, and a groove can be arranged in the middle of the lower body garden cone, and they can realize accurate positioning during installation. There may be a positioning wedge in the inner side of said upper external threaded sleeve, and a positioning groove at a corresponding position outside the internal threaded sleeve.

Function and characteristics of the present invention are as follows:

(1) The main body of the nozzle of the present invention adopts the basic structure of the outer garden and the inner side, including a rectangular optical path channel, a rectangular axial protective gas channel and an internal cooling water channel, passing through the internal cooling water channel and the cooling water channel of the external double-sided powder feeding seat , to ensure the effective cooling of the key parts of the whole nozzle and the long-term stable operation of the nozzle; the present invention specially sets a replaceable rectangular nozzle head at the end of the rectangular optical path channel, so that it can be replaced in case the end is burned due to laser reflection Keep using it to ensure long working hours.

(2) The present invention adopts double-sided symmetrical simultaneous broadband powder feeding structure to ensure the same direction before and after broadband laser cladding. The double-sided wide-band powder feeding structure includes double-sided rectangular powder feeding seats and multiple pairs of rectangular wide-band powder feeding heads. The powder feeding seat on both sides is connected with the main body, the structure is solid, and the outside is cooled by water. A wedge-shaped cavity is opened inside the powder feeding seat, and a rectangular wide-band powder feeding head is placed in the cavity. The upper part of the powder feeding head is an external powder inlet. After passing through the unique fan-shaped wedge gap, a uniform linear broadband powder flow is formed, which is sprayed from the end of the powder feeding head. The two-sided symmetrical broadband powder flow converges to form a linear broadband powder flow, which makes the cladding performance consistent in the front and rear directions of broadband laser cladding. By replacing four groups of rectangular wide-band powder feeding heads with different fan-shaped wedge-slit outlet widths, graded broadband powder feeding is realized.

(3) The present invention adopts a two-body split structure, and the upper body realizes the transition connection with various laser processing heads with threads or screws, and the nozzle can be conveniently connected with any laser processing head. The upper and lower bodies are connected by clasps to realize flexible and convenient split vertical loading and unloading functions, and the powder, gas, and water pipelines will not be entangled during loading and unloading.

(4) The upper body of the nozzle of the present invention adopts the basic structure of a double-layer threaded sleeve, and an additional adjustment thread is placed in the middle of the inner and outer threaded sleeves to realize the stepless adjustment of the defocus amount; through a positioning wedge in the outer sleeve and the inner sleeve The positioning groove in the barrel ensures that the lower body of the nozzle moves vertically up and down without rotation during adjustment, ensuring the consistency of broadband powder feeding and broadband laser beam.

(5) The nozzle head at the end of the broadband nozzle of the present invention and the powder feeding seats on both sides are designed as a reverse cone structure facing the workpiece, which can not only reflect and focus the harmful laser energy reflected on the surface of the workpiece back to the melting pool, but also improve the The utilization rate of laser beam energy can be improved, and the powder flow bounced and sputtered on the surface of the workpiece can be reflected back to the molten pool to improve the utilization rate of the powder.

(6) Due to its good water cooling performance, the wide-band nozzle of the present invention can work at a relatively close distance from the workpiece, and both the axial protective gas in the middle and the powder-feeding inert gas on both sides can form a good gas protection for the surface of the high-temperature molten pool environment.

The applicable fields of the nozzle of the present invention are large-area powder-feeding laser cladding, large-area powder-feeding laser alloying, large-area preset powder laser cladding, large-area preset powder laser alloying, large-area laser remelting, large-area laser Wide range of applications such as phase transformation hardening.

Description of drawings

Fig. 1 is a schematic cross-sectional view of an embodiment of a bidirectional adjustable broadband laser cladding powder feeding nozzle of the present invention.

Fig. 2 is a partial side view of Fig. 1, showing the structure of the powder feeding seat.

Specific Embodiments The present invention designs a split-type laser cladding wide-band powder feeding nozzle with bidirectional symmetrical powder feeding and adjustable width vertical loading and unloading. Its embodiments are described as follows in conjunction with the accompanying drawings:

The main structure of this embodiment is shown in FIG. 1 . The broadband nozzle consists of upper and lower parts. The upper body of the nozzle is composed of an externally threaded sleeve 11, an internally threaded sleeve 12 and an adjusting threaded cylinder 13. The lower body of the nozzle, that is, the main body of the nozzle, consists of an outer cone 21, a middle rectangular body 22, a lower rectangular cone 23, a replaceable rectangular nozzle 25, Both sides of the symmetrical powder feeding seat 24 and its outer cooling water channel 27 are composed of arrays of rectangular wide-band powder feeding heads 26 . The upper and lower parts are connected by buckle flaps. The externally threaded sleeve 11 is the connection between the entire nozzle and the laser processing head, and the externally threaded sleeve 11, the internally threaded sleeve 12 and the adjusting threaded cylinder 13 form a vertically up and down directional defocus adjustment mechanism. The inner cone cavity of the middle rectangular body 22 and the replaceable rectangular nozzle 25 form an internal focused laser beam channel 30; the middle rectangular body 22 and the lower rectangular cone 23 form an axial shielding gas channel 31; the outer circular cone 21 and the lower rectangular cone 23 forms the internal cooling water channel 32; the rectangular wide-band powder feeding head 26 is a wide-band powder feeding channel; the replaceable rectangular spray head 25 and the lower ends of the powder feeding seats on both sides form the reverse cone structure at the end of the nozzle.

Function and characteristic of this embodiment:

(1) The outer cone 21 of the present embodiment adopts the basic structure of the inner side of the outer garden, and includes an internal focused laser beam channel 30 composed of a middle rectangular body 22 and a replaceable rectangular nozzle 25; the middle rectangular body 22 and the lower rectangular cone 23 constitutes a rectangular axial shielding gas channel 31; an inner cooling water channel 32 composed of an outer cone 21 and a lower rectangular cone 23, and two groups of powder feeding seats 24 symmetrical on both sides are equipped with an outer cooling water channel 27; The internal cooling water channel 32 and the external cooling water channel 27 of the double-sided powder feeding seat ensure the effective cooling of the lower rectangular cone 23, the replaceable rectangular nozzle 25 and the symmetrical powder feeding seat 24 in the lower body of the nozzle, thereby ensuring the wide-band nozzle. Stable work for a long time; the present invention specially sets a replaceable rectangular nozzle 25 at the end of the rectangular optical path channel, so that it can be replaced and continued to be used in case the end is burned due to laser reflection, ensuring long-term work.

(2) This embodiment adopts a double-sided symmetrical simultaneous broadband powder feeding structure to ensure the same direction before and after broadband laser cladding. The double-sided wide-band powder feeding structure includes a double-sided rectangular powder feeding seat 24 and multiple pairs of rectangular wide-band powder feeding heads 26. The double-sided powder feeding seat 24 is connected with the outer cone 21. The structure is solid. The inner side is cooled by the internal cooling water channel 32, and the outer side is cooled. It is cooled by its self-assigned cooling water channel 27, and the inside and outside are cooled simultaneously with the wide-band powder feeding head. There is a wedge-shaped cavity inside the powder feeding seat 24, and a rectangular wide-band powder feeding head 26 is placed in the cavity. The upper part of the powder feeding head is an external powder inlet. The powder flows through the unique fan-shaped wedge gap 28 to form a uniform linear wide-band powder flow, which is sprayed from the end of the powder feeding head. The two-sided symmetrical broadband powder flow converges to form a linear broadband powder flow, which makes the cladding performance consistent in the front and rear directions of broadband laser cladding. By replacing four sets of rectangular wide-band powder feeding heads with different fan-shaped wedge seam 28 outlet widths, 10-30mm graded wide-band powder feeding can be realized.

(3) This embodiment adopts a two-body split structure, and the upper body is threaded to realize transitional connection with various laser processing heads. This nozzle can be easily connected with any laser processing head. The upper and lower bodies are connected by clasps to realize flexible and convenient split vertical loading and unloading functions. The lower body of the nozzle can be easily separated from the processing head vertically for necessary adjustments, cleaning, and installation of focusing mirrors. winding. Accurate positioning is realized by the groove on the boss at the lower end of the internally threaded sleeve 12 and the groove in the middle of the outer garden cone 21 during installation.

(4) The upper body of the nozzle in this embodiment adopts the basic structure of double-layer threaded sleeves 11 and 12, and the stepless adjustment of the defocus amount of ±10mm can be realized by rotating and adjusting the threaded sleeve 13; The positioning groove in the inner threaded sleeve 12 ensures that the lower body of the nozzle moves vertically up and down without rotation during adjustment, and ensures the consistency between the broadband powder feeding and the broadband laser beam.

(5) The end of the broad-band nozzle in this embodiment can replace the rectangular nozzle 25 and the lower end of the rectangular wide-band powder feeding head 26 on both sides is designed as a reverse cone structure facing the workpiece, which can not only reflect harmful laser light from the surface of the workpiece The energy is re-reflected and focused back to the molten pool to improve the utilization rate of the laser beam energy, and it can also reflect the powder flow bounced and sputtered on the surface of the workpiece back to the molten pool to improve the utilization rate of the powder.

(6) The lower body of the broadband nozzle in this embodiment is composed of an inner cooling water channel 32 composed of an outer garden cone 21 and a lower rectangular cone 23, and an outer cooling water channel 27 equipped with a symmetrical powder feeding seat 24 on both sides to ensure good water cooling performance, the nozzle can work at a relatively close distance from the workpiece, the rectangular axial shielding gas channel 31 composed of the middle rectangular body 22 and the lower rectangular cone 23 and the inert gas of the rectangular wide-band powder feeding heads 26 on both sides can be used for high temperature melting The surface of the pool forms a good gas protection environment.

Claims (5)

1, a kind of adjustable wide-band bidirectional symmetry powder-feeding laser melting-painting nozzle is made up of the upper body that is coupled to each other and lower body two parts; It is characterized in that two groups of powder feeding seats (24) that this lower body comprises the cylindrical cone (21), intermediate rectangular body (22), bottom rectangular cone (23), replaceable rectangle shower nozzle (25) of coaxial setting, be made of array rectangle broadband feeding head (26) and cooling-water duct (27) are formed; Wherein, said intermediate rectangular body (22) is arranged between cylindrical cone (21), the bottom rectangular cone (23), said bottom rectangular cone (23) extension downwards links to each other with replaceable rectangle shower nozzle (25), and said two groups of powder feeding seats (24) symmetry is installed in the both sides of cylindrical cone (21) bottom and replaceable rectangle shower nozzle (25) outside; Said powder feeding seat (24) inside is wedge shape cavity, the inside of said array rectangle broadband feeding head (26) is sector structure, its outlet has different in width, its external dimensions closely contacts with the measure-alike of powder feeding seat (24) inner wedge cavity and with powder feeding seat (24) cavity, and said cooling-water duct (27) is located at powder feeding seat (24) the cavity outside.

2, adjustable wide-band bidirectional symmetry powder-feeding laser melting-painting nozzle as claimed in claim 1 is characterized in that form cavity between said cylindrical cone (21) and the bottom rectangular cone (23), this cavity is inner cooling-water duct (32); Form the rectangle board splitter between said intermediate rectangular body (22) and the bottom rectangular cone (23), this board splitter is axially to protect gas passage (31); Said intermediate rectangular body (22) center is the rectangular cone cavity, and this rectangular cone cavity is path channels (30).

3, adjustable wide-band bidirectional symmetry powder-feeding laser melting-painting nozzle as claimed in claim 1, it is characterized in that, said upper body is placed in the inner thread sleeve (12) in it and is arranged on the middle adjusting thread barrel (23) of internal and external threads sleeve and formed by external thread sleeve (11); This external thread sleeve, inner thread sleeve and adjusting screw thread are formed directed vertically defocusing amount governor motion.

4, adjustable wide-band bidirectional symmetry powder-feeding laser melting-painting nozzle as claimed in claim 1, it is characterized in that, said going up adopts the button lobe to connect between the lower body, the button of this button lobe is fixed on the lower end of upper body inner thread sleeve (12), and lobe is fixed on down on the external cone (21).

5, adjustable wide-band bidirectional symmetry powder-feeding laser melting-painting nozzle as claimed in claim 1 is characterized in that there is a boss said upper body inner thread sleeve (12) lower end, and lower body cone (21) has a groove on the centre.

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