CN111424277B

CN111424277B - Laser cladding powder feeder

Info

Publication number: CN111424277B
Application number: CN202010473071.9A
Authority: CN
Inventors: 时晓宇; 王守仁; 温道胜; 王高琦; 朱国栋; 肖滕; 李金坤; 薛成龙; 杨冰冰
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2022-02-08
Anticipated expiration: 2040-05-29
Also published as: CN111424277A

Abstract

The invention discloses a laser cladding powder feeder, which comprises the following steps of stirring and heating powder in a stirring barrel, evaporating water vapor, and scattering the clustered powder, so that the powder has better fluid property. And a powder disc is arranged below the stirring barrel, and an annular groove is formed in the powder disc and used for receiving powder transferred from the stirring barrel. And a scraper is further arranged on the surrounding shell which surrounds the powder disc and is fixedly arranged so as to scrape the powder in the ring groove, so that the powder on the powder disc is better in dispersion uniformity, the powder amount weighed by the unit ring groove is basically consistent, and the precision of feeding by utilizing the rotation of the powder disc is greatly improved.

Description

Laser cladding powder feeder

Technical Field

The invention relates to a laser cladding powder feeder.

Background

Regarding the laser cladding powder feeder, it can be seen from chinese patent document CN110777377A of the application of the university of denn, and some laser cladding powder feeders are described in the background section thereof. In the embodiment of the invention, the problem of controlling the powder feeding speed is solved firstly. It is understood that the cladding material used for laser cladding has relatively small particle size, in other words, the specific surface area is relatively large, and is easy to absorb moisture, and although the powder has some properties of fluid, the powder has relatively poor fluidity, and particularly, under the condition of moisture absorption, the powder is extremely easy to be blocked or retarded in a relatively thin powder feeding pipe, so that the powder feeding speed is not uniform.

In chinese patent document CN110777377A, a lateral transfer structure is adopted, which comprises a drum, a lateral hole is opened on the lateral surface of the drum, powder enters the lateral hole at the source end, and is discharged at the destination end, and the powder feeding speed can be adjusted by adjusting the rotation speed of the drum. Because the powder material enters the side hole by means of gravity, enters the target end from the side hole based on gravity and is transported in the horizontal direction, the accuracy of powder material transportation is greatly influenced by the depth and the shape of the side hole, and particularly when the powder material at the source end is more, a certain compaction degree can exist, so that the capacity of the side hole is changed, and the transportation accuracy is influenced.

Further, since the chinese patent document CN110777377A does not consider the influence of moisture absorption of powder on the powder feeding speed and precision, such as the aforementioned problem that powder may be clamped in the side hole, the reason for this is also related to moisture absorption of powder, and relatively dry powder is not easily clamped in the hole or the groove.

In chinese patent document CN209010602U, the part for adjusting the feeding speed is located between the powder storage device and the stirring device with a housing to form the feeding opening, on the one hand, the distance between the two parts and the nozzle is relatively far, and the influence of the speed adjustment on the nozzle is very small. In particular, it is difficult to adjust the feeding speed between the powder storage device and the housing by changing the feeding caliber, and it is known that the caliber and the feeding speed have a certain correlation, but the controllability of the correlation is very poor, in other words, accurate feeding cannot be achieved.

The current feed is focused on the control of the feeding speed, the control of the feeding precision is mostly lacked, even if the feeding speed is controlled, the distance between the adjusting node and the nozzle is too far, and the control of the speed is caused by the existence of more subsequent links, so that a larger accumulative error is generated.

Disclosure of Invention

In view of the above, the present invention provides a laser cladding powder feeder with easier control of feeding speed and feeding precision.

In an embodiment of the present invention, there is provided a laser cladding powder feeder, including:

the compressed gas source provides powder feeding working gas;

the stirring device is provided with a stirring barrel and a stirring assembly for stirring the powder in the stirring barrel, wherein the lower end of the stirring barrel is provided with a nozzle for discharging;

the heating device is used for heating the powder in the stirring device;

the powder disc is arranged below the nozzle through a vertical rotating shaft and is provided with an annular groove which is coaxial with the powder disc and has an upward notch, and one side of the annular groove is a bearing side for bearing powder discharged from the nozzle;

the enclosing shell is fixedly installed and circumferentially surrounds the periphery of the powder disc, and a discharge hole is formed in the side opposite to the receiving side;

the scraping plate is positioned on the rear side of the surrounding shell corresponding to the bearing part of the bearing side in the rotation direction of the powder disc and is used for scraping the powder in the ring groove;

the guide plate is positioned on the side of the discharge port and used for guiding the powder in the annular groove into the discharge port;

the output of the driving device is connected with the rotating shaft so as to drive the powder disc to rotate;

and the nozzle is connected with the compressed air source and is used for receiving the material discharged from the discharge port through the adapter assembly.

Optionally, the gas path connecting the compressed gas source and the nozzle is a first branch;

and providing a second branch, wherein the second branch is used for connecting a compressed air source with the upper part of the stirring barrel.

Optionally, the stirring barrel is provided with a feed inlet for continuous feeding.

Optionally, the powder tray is positioned in a housing or a closed box body;

accordingly, the agitating barrel has an extension extending into the tank body or under the casing.

Optionally, the extension part is provided with a hopper mouth with a big top and a small bottom, and the hopper mouth is used for gathering powder and feeding the powder to the annular groove;

accordingly, the mouth is included in the mouth.

Optionally, a sieve tray is arranged at the lower part of the stirring barrel or at the upper side of the mouth part.

Optionally, the sieve tray is assembled on the agitator tank by a detachable connection structure.

Optionally, the ring groove is configured to:

the powder disc comprises a disc-shaped disc part and a cylindrical or spherical crown-shaped convex part coaxial with the disc part, wherein after the convex part occupies the upper end surface of the disc part, the remaining part of the upper end surface of the disc part forms a groove bottom, and the side surface of the convex part forms an inner side groove wall for determining the ring groove;

correspondingly, the surrounding shell forms an outer groove wall of the annular groove.

Optionally, the guide plate is a vertical plate with the root part connected to the rear frame of the discharge port and extending obliquely to the front side in the groove to the inner side groove wall;

the lower edge of the guide plate is in sliding fit with the bottom of the groove.

Optionally, the mouth is provided with a backing discharge speed adjustment structure or mechanism.

Compared with the traditional laser cladding powder feeder, in the embodiment of the invention, the powder is stirred and heated in the stirring barrel, so that water vapor is evaporated, and the cluster-shaped powder is scattered, so that the powder has better fluid property. And a powder disc is arranged below the stirring barrel, and an annular groove is formed in the powder disc and used for receiving powder transferred from the stirring barrel. And a scraper is further arranged on the surrounding shell which surrounds the powder disc and is fixedly arranged so as to scrape the powder in the ring groove, so that the powder on the powder disc is better in dispersion uniformity, the powder amount weighed by the unit ring groove is basically consistent, and the precision of feeding by utilizing the rotation of the powder disc is greatly improved.

Drawings

Fig. 1 is a schematic front view of a laser cladding powder feeder in an embodiment.

Fig. 2 is a schematic perspective view of a laser cladding powder feeder in an embodiment.

FIG. 3 is a schematic diagram of a feeding speed adjusting mechanism according to an embodiment.

In the figure: 1. the powder mixing device comprises an air inlet pipe, 2, a gas station, 3, a first branch, 4, a second branch, 5, a rotating motor, 6, a bucket nozzle, 7, a sieve tray, 8, a stirring assembly, 9, a powder inlet, 10, a stirring motor, 11, a stirring barrel, 12, a conical part, 13, a heating device, 14, a convex part, 15, a guide plate, 16, a box body, 17, a powder collecting pipe, 18, a connecting cone, 19, a nozzle, 20, a surrounding shell, 21, a scraping plate, 22, a disk part and 23, and a discharge hole.

Detailed Description

It should be noted that, referring to fig. 3 of the specification, in the embodiment of the present invention, the rotating powder disk includes the convex portion 14 and the disk portion 22 in fig. 3, the powder disk rotates counterclockwise in the drawing, and the powder received in the annular groove defined between the enclosure 20 and the powder disk is first scraped by the scraper 21 fixedly provided and then sequentially guided by the guide plate 15. The scraper 21 is located on the rear side of the mouth 6 in fig. 1 in the counterclockwise direction of rotation as viewed in the material flow direction, and the guide plate 15 is attached to a rear frame defining the discharge port 23 and extends forward to the projection 14, thereby forming a guide surface for guiding the powder into the discharge port 23.

The above is a structure of a preferred embodiment of the invention and does not imply that such a structure is necessarily employed, for purposes of example, for purposes of basic reference frame determination.

It will be appreciated that as a mechanical device, there is a mechanical frame, which is not explicitly identified in fig. 1. Further, in mechanical analysis, a relatively fixed part can be understood as a frame to which a part is moved relatively. In addition, for relatively fixed components, such as the box 16 in fig. 1, which may be rack-mounted components, the skilled person will not misunderstand that they may be understood as racks themselves in the mechanism analysis, in which the racks are usually machine bodies, and the mechanisms themselves are a unit, and several mechanisms in a device may have their own respective racks.

In a laser cladding powder feeder shown in fig. 1 and 2, it comprises a gas station 2, and the gas station 2 is used as a gas source of a powder feeding working gas. It will be appreciated that in more applications, the plant will provide a general compressed gas station for distribution of gas through pipes for cost savings, and that in embodiments of the invention, plant gas sources may be used, or separate compression pumps or compressors may be provided.

It should be further noted that the powder feeding working gas is more often required to be an inert gas such as argon, and the centralized gas distribution application is more extensive.

In the construction shown in figure 1, stirring means are provided where it is necessary to effect stirring of the powder to disperse the agglomerated powder, under conditions where it is more likely to be stirred if heated to cause the powder to lose moisture. Thus, in a preferred embodiment, the heating means are provided adapted to the stirring means, which are preferably mounted on the relatively static stirring barrel 11.

Specifically, as can be seen in fig. 1, the stirring device includes a stirring barrel 11, the stirring barrel 11 is vertically disposed, the axis of the stirring shaft 11 is vertical, the stirring barrel 11 is a relatively closed barrel in the figure, and water vapor can overflow from the nozzle 6 along with the powder feeding gas.

If the second branch 4 in fig. 1 is absent, the mixing drum 11 may be an open structure, with the opening on the top, and can be charged in batches.

In the structure shown in fig. 1, the stirring barrel 11 is a relatively closed barrel body, and the side surface of the stirring barrel is provided with the feeding port 9, so that powder can be fed by, for example, gas conveying for continuous feeding.

The stirring assembly 8 is installed in the stirring barrel 11, the stirring assembly 8 comprises a stirring shaft, the stirring shaft is coaxial with the stirring barrel 11 in the figure 1, and a group of blades are arranged at the lower part of the stirring shaft.

Based on the principle of the invention, it is not necessary to stir the powder distributed in the axial direction of the stirring shaft wholly, but only part of the powder is stirred.

Accordingly, in the preferred embodiment of the present invention, the heating object of the heating device 13 is also the powder material being stirred, therefore, in the structure shown in fig. 1, the heating device 13 is installed at the tapered portion 12 in the figure, and the energy consumption and the torque of the stirring shaft can be saved as a whole.

In fig. 1, the lower end of the mixer drum 11 has a spout for discharging, which is located above the spout 6 in fig. 1 and constitutes an outlet of the spout 6.

In a more preferred embodiment, the heating means is arranged at the lower part of the conical portion 12.

With respect to the aforementioned powder pan, it is pointed out in the foregoing that it includes the convex portion 14 and the pan portion 22 shown in fig. 3, and the convex portion 14 and the pan portion 22 are also a single pan body as a whole.

The powder disk is mounted below the mouthpiece by means of a vertical pivot shaft, and as mentioned above, has an annular groove (not shown, but clearly evident from fig. 3) coaxial with the powder disk and with an upward facing notch, one side of the annular groove being the receiving side for receiving the powder emerging from the mouthpiece, which is shown on the left in fig. 1.

In fig. 3, a housing 20 is provided around the powder pan, and the housing 20 is fixedly mounted on a frame, which may be the box 16 shown in fig. 1.

The surrounding shell 20 is circumferentially wrapped on the periphery of the powder disc and is in dynamic sealing fit with the powder disc, and polytetrafluoroethylene can be sprayed on the inner surface of the surrounding shell 20 to form a polytetrafluoroethylene coating so as to reduce the friction coefficient and improve the wear resistance.

In addition, in some embodiments, the inner surface of the enclosure 20, or the portion that mates with the powder pan, may be lined with a teflon slide.

In fig. 3, it can be seen that the enclosure 20 has a discharge opening 23 on the right side of the structure shown in fig. 3, and the discharge opening 23 is opposite to the receiving side, so that other components can be conveniently arranged, and space can be saved.

Further, as shown in fig. 3, the left side of the drawing is provided with a scraper 21 which is fixedly arranged relative to the powder pan, and in the structure shown in fig. 3, the scraper 21 is mounted on the enclosure 20, preferably welded.

In contrast, as described above, the scraper 21 is located on the rear side of the surrounding case 20 corresponding to the receiving-side receiving portion, based on the rotational direction of the powder pan.

In any pipeline transportation, the flowability of the powder is poor relative to the fluid, and the uniformity of the pipeline transportation is difficult to ensure. Similarly, the discharge from the nozzle 6 is uniform, and the nozzle 6 has a ridge structure with a high middle and low two sides on the powder tray based on the Newton internal friction force, and has a state that peaks are connected. Due to the existence of the scraper 21, the powder can be uniformly distributed in the ring groove effectively, the higher part of the material pile is scraped to the lower part, and more parts can be pushed forwards, so that the uniformity of powder blanking can be ensured.

It will be appreciated that, in relation to the fact that the material exiting the mouth 6 may be at a higher speed than the material exiting at the outlet 23, part of the powder may be eventually pushed out by the scraper 21, and a collection trough may be provided on the underside of the scraper 21.

Further, as described above, in order to facilitate the discharge of the powder, a guide plate 15 is provided on the discharge port 23 side for guiding the powder in the ring groove to the discharge port 23.

Suitably, a driving means is provided, which is connected to said rotating shaft so as to drive said powder disk in rotation.

In order to facilitate speed regulation, the driving device can adopt a servo motor to be matched with a reduction gearbox, or simply use the servo motor, so that the relative accuracy of the output rotating speed can be ensured.

The powder is finally supplied to the nozzles 19, and in fig. 1 the powder, which is conducted from the outlet 23, is connected directly via a powder collecting duct 17 to the first branch 3, which supplies the working gas, which is mixed with the powder in the first branch 3 and is ejected from the nozzles 19.

In fig. 1, the first branch 3 is necessary, the second branch 4 is an optional branch, and the second branch 4 is used for communicating the gas station 2 with the stirring barrel 11, so that the stirring barrel 11 maintains positive pressure, and rapid discharge of powder is facilitated.

The specific surface area of the powder is large, the powder is easy to blow away by wind, a certain distance exists between the hopper nozzle 6 and the powder tray, and the distance needs to be set for the purpose of convenient feeding.

Accordingly, the agitation vat 11 has an extension extending into the tank 16 or under the casing.

Further, the extension part is provided with a bucket mouth 6 with a big top and a small bottom, and the bucket mouth is used for gathering powder and feeding the powder to the ring groove.

In order to make the fed materials uniformly distributed, the outlet of the hopper mouth 6 can be a rectangular mouth, and the width of the rectangular mouth in the radial direction of the powder plate is the same as that of the ring groove.

Accordingly, the mouth is included in the mouth.

The powder with the granularity of 200 meshes is not uniform, so the powder with the granularity of 200 meshes is a material which can pass through the sieve with the granularity of 200 meshes, but the powder after passing through the sieve still has the problem of excessive granularity caused by clustering for various reasons such as clustering of the powder. For this purpose, a sieve tray 7 is provided at the lower part or upper side of the mouth of the agitator tank 11 to filter out large-particle powders.

As described above, the content of large-particle powder is not large, and therefore, the problem of clogging of the sieve tray 7 with large-particle powder does not occur.

Furthermore, the sieve tray 7 should be replaceable in order to accommodate different applications. For example, with the mouth 6, by way of a flange connection, at the lower mouth of the cone 12 in fig. 1.

In some embodiments, the sieve tray 7 may be of the insert type; the form is installed at the lower end of the conical part 12, the corresponding slot of the inserting plate is generally provided with a left slot, a right slot and a top slot, the three slots are opposite to three edges of the inserting plate, the whole body is a U-shaped slot, and the inserting plate can be inserted from the reserved slot opening.

In a preferred embodiment, the ring groove is configured to:

the powder plate comprises a disc-shaped disc part 22 and a cylindrical or spherical crown-shaped convex part 14 coaxial with the disc part 22, after the convex part 14 occupies the upper end surface of the disc part 2, the remaining part of the upper end surface of the disc part 22 forms a groove bottom, and the side surface of the convex part 14 forms an inner side groove wall defining a ring groove, so that the structure is convenient for the arrangement of the guide plate 15.

Accordingly, the surrounding shell 20 forms the outer groove wall of the annular groove.

In fig. 3, the guide plate 15 is a vertical plate whose root is connected to the rear frame of the discharge port 23 and extends obliquely to the front side in the groove to the inner side groove wall.

Accordingly, the lower edge of the guide plate 15 is in sliding engagement with the bottom of the slot.

In order to regulate the feeding speed as a whole, the mouth is provided with a preceding stage discharging speed regulating structure or mechanism, preferably an electric gate valve with adjustable opening degree.

Claims

1. A laser cladding powder feeder, comprising:

the compressed gas source provides powder feeding working gas;

the heating device is used for heating the powder in the stirring device;

the nozzle is connected with the compressed air source and is used for receiving the material discharged from the discharge port through the adapter assembly;

the ring groove is configured as follows:

correspondingly, the surrounding shell forms the outer side groove wall of the ring groove;

the guide plate is a vertical plate with the root part connected to the rear frame of the discharge port and extending to the front side in the groove to the inner side groove wall;

the lower edge of the guide plate is in sliding fit with the bottom of the groove;

the gas circuit connecting the compressed gas source and the nozzle is a first branch circuit;

2. The laser cladding powder feeder of claim 1, wherein the agitator has a feed port for continuous feed.

3. The laser cladding powder feeder of claim 1, wherein the powder tray is located within a housing or enclosed box;

4. The laser cladding powder feeder of claim 3, wherein the extension has a large top and a small bottom for gathering powder to feed to the ring groove;

accordingly, the mouth is included in the mouth.

5. The laser cladding powder feeder of claim 1, 3 or 4, wherein a sieve tray is provided at a lower portion of the stirring barrel or at an upper side of the mouth.

6. The laser cladding powder feeder of claim 5, wherein the sieve tray is assembled on the agitator barrel by a detachable connection structure.

7. The laser cladding powder feeder of claim 1, wherein the nozzle is provided with a pre-staging discharge speed adjustment structure or mechanism.