CN104668562B - Shielding-free laser-path-coaxial powder conveying method and shielding-free laser-path-coaxial powder conveying device - Google Patents

Abstract

The invention discloses a shielding-free laser -path-coaxial powder conveying method and a shielding-free laser-path-coaxial powder conveying device. The shielding-free laser-path-coaxial powder conveying method includes the steps of (1) forming a non-laser area and a laser area in an optical path formed by the fact that a laser beam is focused on a base material focus point via an annular reflecting and focusing mirror; (2) arranging a powder conveying pipe, which is used for conveying powder materials to the base material focus point, in the non-laser area to be kept away from laser radiation, and enabling a spraying nozzle of the powder conveying pipe to be coaxial with the center of the laser beam. The shielding-free laser-path-coaxial powder conveying method and the shielding-free laser-path-coaxial powder conveying device have the advantages that the powder conveying pipe is kept away from direct radiation of high-power laser and prevented from being damaged, and complete coaxiality of the laser and powder conveying is achieved.

Description

Coaxial powder feeding method and powder feeding device without shielding laser optical path

technical field

The invention relates to the fields of laser powder forming and manufacturing and laser cladding, in particular to a coaxial powder feeding method and a powder feeding device without shielding the laser light path.

Background technique

With the development of science and technology, laser cladding forming technology is more and more widely used in the production process. Laser cladding forming refers to the metal raw material (powder or wire) which is melted and transported by laser under the direct drive of CAD model, which is scanned, melted and piled up layer by layer to directly form dense metal parts. One of the most critical technologies in this forming is how to deliver the laser and the material to be processed to the processing area synchronously for optical material coupling forming.

The existing feeding methods are divided into two types: optical external oblique axis feeding and optical internal coaxial feeding.

The principle of optical external oblique axis feeding is: do not change the path of light, let the laser beam enter directly along the axis, and arrange multiple feeding tubes evenly and obliquely at a certain angle around the laser beam. This feeding method is relatively simple and easy to implement, but the raw material sent from the feeding pipe will fall in a parabola due to the influence of its own gravity and air resistance, resulting in a larger falling area of the raw material and an uneven distribution of the raw material, which affects the processing accuracy.

The principle of coaxial feeding in the light is: relying on a certain method, the laser incident along the axis is reflected to the surroundings to form a circular beam. The beam forms a conical hollow laser-free area inside the nozzle, and the feeding from the outside The tube then feeds the material along the axis so that it coincides with the focal point of the incident laser. Although this feeding method is more complicated than optical external inclined axis feeding, in this method, the raw material is sent directly along the axis of the laser, and the self-gravity and air resistance it receives are collinear with the direction of motion, so the feeding method The method is more accurate than the optical external oblique axis feeding method.

Chinese invention patent CN101386111A discloses a cladding method and an internal optical wire feeding device for laser optical internal wire feeding. This method adopts the principle of optical internal coaxial feeding. The device uses a conical light mirror to convert the laser beam emitted by the laser into a ring beam, and then uses a ring focus lens to focus it into a ring cone beam, forming a cone-shaped hollow laser-free zone in the ring cone beam, and the wire feeding tube is placed here. In the laser-free area and coaxial with the ring cone beam, the wire is coaxially and vertically fed into the molten pool on the processing surface at the center of the ring cone beam during work, realizing coaxial wire feeding in the light. This method realizes the complete coaxiality of the focused beam and the feeding material, but the wire feeding tube needs to cross the beam when it reaches the hollow area from the outside of the ring cone beam, and when the laser is irradiated on the light-facing surface of the wire feeding tube, a lot of heat will be generated , and when the heat is too large, the wire feeding tube will be melted and the entire optical wire feeding device will fail. Therefore, this method is only suitable for medium and small power laser processing, and has certain limitations.

With the development of society, high-power laser forming gradually forms a trend, so it is necessary to design an optical feeding device, so that the whole device can avoid the direct irradiation of high-power laser, and can realize the complete coaxiality of laser and feeding.

Contents of the invention

The present invention aims to provide a method and device for coaxial powder feeding without shielding the laser light path, so that the powder spray head can avoid direct irradiation of high-power laser, avoid damage, and realize complete coaxiality of laser and material feeding.

In order to achieve the above object, the technical solution adopted in the present invention is:

A coaxial powder feeding method without shielding the laser light path, which includes

1) A non-laser area and a laser area are formed on the optical path where the laser beam is focused to the focal point of the substrate through the circular reflective focusing mirror;

2) Set the powder feeding tube that delivers the powder to the focal point of the substrate in the laser-free area to avoid laser irradiation, and the nozzle of the feeding tube is coaxial with the center of the laser beam.

Following is the further improved technical scheme of the present invention:

The laser beam is reflected to the annular reflective focusing mirror through the conoscopic mirror, and at least one non-reflective area is formed on the conical surface of the conoscopic mirror.

The conoscopic mirror is an arc conoscopic mirror formed by connecting at least two sections of inferior arcs.

The tapered surface of the conoscopic mirror is provided with at least one slope as a non-reflection area.

At least one non-reflection area is formed on the mirror surface of the reflection focusing mirror.

Further, the present invention provides a coaxial powder feeding device without shielding the laser light path, which includes

- Conoscopic mirrors for reflecting the laser beam;

—Annular reflective focusing mirror, which is used to reflect the laser beam reflected by the conoscopic mirror to the substrate and form a focus; its structural characteristics are:

There is at least one non-reflective area on the conical surface of the conoscopic mirror, and the non-reflective area makes at least one laser-free area formed between the reflective focusing mirror and the focal point on the substrate when the reflective focusing mirror reflects the laser light onto the substrate;

- The powder feeding pipe is arranged in the laser-free area, and the nozzle of the powder feeding pipe is located directly above the focal point; the conoscopic mirror, reflective focusing mirror and nozzle are coaxially arranged.

As a specific structural form, the conical surface of the conoscopic mirror has at least one inclined surface as a non-reflective area, and the area outside the inclined surface is a conical arc surface. This structure is referred to as a tangential conoscopic mirror.

Preferably, the horizontal projection of the laser-free zone is fan-shaped.

Preferably, the central angle of the inferior arc is greater than 60° and less than 180°.

As another specific structural form, the contour line of the cross section of the conoscopic mirror is formed by butt joints of at least two inferior arcs, and the connecting line of two adjacent inferior arcs of the conoscopic mirror forms a non-reflective area. As a result, a left arc conoscope and a right arc conoscope are formed between the two non-reflecting areas, and the existing conoscope (the entire cone is Surfaces are reflective areas), so that the laser emitted by the laser is scattered into multiple laser beams after being reflected by the arc conoscope. There is a part of no-laser area between these beams of light, and the feeding tube can be placed in this no-laser area to avoid direct laser irradiation, and can realize that the laser and the feeding material are completely coaxial.

Compared with the prior art, the beneficial effect of the present invention is: the present invention solves the situation that the coaxial powder feeding device in the light is only limited to low-power laser processing, and can completely avoid the direct irradiation of the laser for the wire feeding tube , to avoid burning failure, and to achieve complete coaxial laser and feeding.

The present invention will be further elaborated below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the front view of a kind of embodiment of the present invention;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the optical path sectional view of the plane at the dotted line in Fig. 1;

Fig. 4 is the side view of Fig. 1;

Fig. 5 is the schematic diagram of the left (right) arc conoscopic mirror of the present invention;

Fig. 6 is the reflection schematic diagram of the trimming type conoscopic mirror;

Fig. 7 is a partial enlarged view of the cross-section of the trimming type conoscopic lens;

In the picture:

1-Laser beam emitted by the laser; 2-Left arc conoscope; 3-Right arc conoscope; 4-Annular reflective focusing mirror; 5-Powder feeding tube; 6-Support arm; 7-Nozzle; 8- Substrate; 9-left arc conoscope laser beam; 10-no laser area; 11-right arc conoscope laser beam; 12-conical light mirror laser beam; 13-conical light mirror; Conoscopic mirror; 15-arc surface; 16-bevel.

detailed description

A coaxial powder feeding method without shielding the laser light path, which mainly divides the incident laser beam into a number of reflective areas and non-laser areas in a certain way, as shown in Figures 1 and 2, and consists of two inferior arcs. The arc conoscopic mirror divides the laser light in this way. The light beam in the reflective area is focused by the ring focus lens to form a ring cone beam and finally converges on the substrate, while in the non-laser area because there is no laser beam, there will be no laser beam from the plane where the ring focus lens is located to the plane where the substrate is located. Several segments of approximately cone-shaped laser-free areas appear. FIG. 3 is a cross-sectional view of the optical path of the plane at the dotted line in FIG. 1 . As shown in FIG. 3 , there is a laser-free region in the plane where no laser passes through at both ends. Therefore, as shown in Figure 4, the feeding pipeline located outside the ring cone beam can avoid the direct irradiation of the laser, and enter the interior of the laser through these non-laser areas, so as to achieve coaxiality with the center of the beam.

The invention discloses two different devices for splitting laser beams to realize the coaxial powder feeding method without shielding the optical path. One structural form is to make an arc conoscopic mirror composed of two inferior arcs. When the incident laser passes through the arc conoscopic mirror, two sections of laser reflection area and no laser area will be generated. The specific principles are shown in Figure 2 and Figure 5. Another structural form is to make a conical light mirror and perform certain processing on it, so that two symmetrical slopes are ground on the corresponding two sides of the conical light mirror. When the incident laser passes through the edge-cut conical light mirror There will be four sections of laser reflection areas and four sections of no laser areas. The specific principles are shown in Figures 6 and 7. As shown in FIG. 7 , the central angle β of the trimmed slope of the trimmed conoscopic mirror is less than 90°. FIG. 7 exemplifies the trimmed edges at both ends, and may also be multi-segment trimmed edges.

A specific structural form corresponding to the powder feeding method of the present invention is a coaxial powder feeding device with no shielding of the laser light path, as shown in accompanying drawing 1, the left arc conoscope 2 and the right arc conoscope 3 are in common The formed arc conoscopic mirror is arranged coaxially with the annular reflective focusing mirror 4 and the nozzle 7, and the axis of the support frame is perpendicular to the central axis. The laser beam 1 first irradiates the left and right arc conoscopic mirrors 2 and 3, and is reflected by the left and right arc conoscopic mirrors 2 and 3 onto the annular reflective focusing mirror 4 to form an annular beam and focus on the substrate 8. The arc conoscopic mirror is shown in Figure 2.

As shown in FIG. 2 , since the arc conoscope is used instead of the conoscope, two fan-shaped laser-free zones 10 can be formed when the laser is irradiated on the arc conoscope. Its principle is referring to accompanying drawing 5, and what laser beam is formed after the reflection of conical mirror 13 is semicircular conical mirror laser beam 12, and angle is 180 °. And left circular arc conoscopic mirror 2 its circle center o ' is positioned at below the circle center o of conical light mirror 13, and central angle is also less than 180 °, so what forms after the laser is reflected by left circular arc conoscope 2 is left circular arc cone The optical mirror laser beam 9 has an angle α smaller than 180°. As shown in Figure 2, when the laser passes through the arc conoscope composed of the left arc conoscope 2 and the right arc conoscope 3, two fan-shaped laser-free zones 10 can be formed. As shown in Fig. 4, the support arm 6 connecting the left and right arc conoscopic mirrors 2, 3 and the nozzle 7 is just arranged below the fan-shaped laser-free area 10, so that the direct irradiation of the laser 1 can be avoided.

The above-mentioned embodiments should be understood that these embodiments are only used to illustrate the present invention more clearly, and are not intended to limit the scope of the present invention. After reading the present invention, those skilled in the art will understand the various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of this application.

Claims (9)

1. a kind of unobstructed coaxial powder-feeding method of laser optical path is it is characterised in that include

1）, in laser beam（1）Through annular reflection focus lamp（4）Focus to base material（8）Formed in the light path of focus point and no swash Light area and have laser zone；

2）, will be to base material（8）Focal spot conveys the powder feeding pipe of powder（5）It is arranged in described no laser zone and avoid laser photograph Penetrate, powder feeding pipe（5）Shower nozzle and laser beam central coaxial；

Laser beam（1）Reflex to the reflection focus lamp of annular through conoscope（4）On, the conical surface of this conoscope forms at least one Place's non-reflective.

2. the unobstructed coaxial powder-feeding method of laser optical path according to claim 1 it is characterised in that described conoscope be to Few two sections of minor arcs connect the circular arc conoscope being formed.

3. the unobstructed coaxial powder-feeding method of laser optical path according to claim 1 is it is characterised in that the cone of described conoscope Face is provided with least one section inclined-plane as non-reflective.

4. the unobstructed coaxial powder-feeding method of the laser optical path according to one of claim 1-3 is it is characterised in that described reflection Focus lamp（4）Minute surface on form non-reflective at least.

5. the unobstructed coaxial powder feeding apparatus of a kind of laser optical path, including

Conoscope, for reflecting laser beam（1）；

The reflection focus lamp of annular（4）, for the laser beam that will come through conoscope reflection（1）Reflex to base material（8）Upper simultaneously shape Become focus；It is characterized in that,

At least one non-reflective is had on the conical surface of described conoscope, this non-reflective makes reflection focus lamp（4）Reflection laser To base material（8）In reflection focus lamp when upper（4）With base material（8）Form at least one no laser zone between upper focus（10）；

Powder feeding pipe（5）, it is arranged on described no laser zone（10）Interior, this powder feeding pipe（5）Shower nozzle（7）Positioned at described focus just Top；

Described conoscope, reflection focus lamp（4）And shower nozzle（7）Coaxially arranged.

6. the unobstructed coaxial powder feeding apparatus of laser optical path according to claim 5 are it is characterised in that the cone of described conoscope At least one inclined-plane as non-reflective is had on face（16）.

7. the unobstructed coaxial powder feeding apparatus of laser optical path according to claim 5 are it is characterised in that the horizontal stroke of described conoscope The contour line in section is formed by the docking of at least two sections of minor arcs, and the connecting line in adjacent two sections of minor arc faces of conoscope forms non-reflective Area.

8. unobstructed coaxial powder feeding apparatus of laser optical path according to claim 7 are it is characterised in that described no laser zone Floor projection is in sector.

9. the laser optical path according to claim 7 or 8 unobstructed coaxial powder feeding apparatus are it is characterised in that described minor arc Central angle is more than 60 ° and is less than 180 °.