阅读说明：本技术 电子束粉末床增材制造振动式铺粉装置 (Vibration type powder paving device for additive manufacturing of electron beam powder bed ) 是由 张向东 唐辉 张建飞 黄汉超 吴宗霖 黄奉宾 郭文明 唐强 秦远 刘强 李黎 于 2019-12-20 设计创作，主要内容包括：本发明公开了一种电子束粉末床增材制造振动式铺粉装置,其下料机构的前、后装粉箱的出粉口处于铺粉平台的前、后部上方；其铺粉机构包括通过移动机构安装于铺粉平台上方前、中、后刮刀,移动机构包括于铺粉平台前、后端作往复运动的左、右移动架,中刮刀固定安装于左、右移动架上,前、后刮刀通过抬刀机构安装于左、右移动架上,移动架向前移动时抬刀机构抬起前刮刀而下降后刮刀,移动架向后移动时抬刀机构抬起后刮刀而下降前刮刀；成型机构包括设于升降架上的成形缸,成形时升起的成形缸于铺粉平台的避让口处平齐于台面。本发明破坏了颗粒群松散堆积结构,提高了粉末层的致密度,让颗粒与颗粒之间得以充分接触,改善了粉层的导电性。(The invention discloses a vibration type powder paving device for additive manufacturing of an electron beam powder bed, wherein powder outlets of a front powder box and a rear powder box of a blanking mechanism are positioned above the front part and the rear part of a powder paving platform; the powder spreading mechanism comprises a front scraper, a middle scraper and a rear scraper which are arranged above a powder spreading platform through a moving mechanism, the moving mechanism comprises a left moving frame and a right moving frame which reciprocate at the front end and the rear end of the powder spreading platform, the middle scraper is fixedly arranged on the left moving frame and the right moving frame, the front scraper and the rear scraper are arranged on the left moving frame and the right moving frame through a cutter lifting mechanism, the cutter lifting mechanism lifts the front scraper and descends the rear scraper when the moving frame moves forwards, and the cutter lifting mechanism lifts the rear scraper and descends the front scraper when the moving frame moves backwards; the forming mechanism comprises a forming cylinder arranged on the lifting frame, and the forming cylinder lifted during forming is parallel and level to the table top at the avoidance port of the powder spreading platform. The invention destroys the loose accumulation structure of the particle group, improves the density of the powder layer, leads the particles to be fully contacted and improves the conductivity of the powder layer.)

1. Electron beam powder bed vibration type powder paving device, including based on the unloading mechanism, spread powder mechanism and the forming mechanism that shop powder platform (1) set up, its characterized in that:

the blanking mechanism comprises a front powder loading box (2) and a rear powder loading box (3), and powder outlets of the front powder loading box (2) and the rear powder loading box (3) are respectively positioned above the front part and the rear part of the powder laying platform (1);

the powder spreading mechanism comprises a front scraper (5), a middle scraper (6) and a rear scraper (7), the front, middle and rear scrapers (5, 6 and 7) are mounted above the powder spreading platform (1) through a moving mechanism, the moving mechanism comprises a left moving frame (8) and a right moving frame (8) which are driven by a transmission mechanism to do linear reciprocating motion at the front end and the rear end of the powder spreading platform (1), the middle scraper (6) is fixedly mounted on the left moving frame (8) and the right moving frame (8), a vibrator (9) is arranged on the middle scraper (6), the front and rear scrapers (5 and 7) are mounted on the left moving frame (8) and the right moving frame (8) through a cutter lifting mechanism, when the left moving frame (8) and the right moving frame (8) move forwards, the cutter lifting mechanism lifts the front scraper (5) and lowers the rear scraper (7), and when the left moving frame (8) moves backwards, the cutter lifting mechanism lifts the rear scraper (7) and lowers the front scraper;

the forming mechanism comprises a forming cylinder (4) which is arranged at the bottom of the powder laying platform (1) and is arranged on the lifting frame (20), an avoiding opening matched with the forming cylinder (4) is formed in the powder laying platform (1), and the forming cylinder (4) which is lifted during forming is parallel and level to the avoiding opening in the powder laying platform (1).

2. The electron beam powder bed additive manufacturing vibratory powdering device of claim 1, wherein: the cutter lifting mechanism comprises a left cutter scraping frame (11) and a right cutter scraping frame (11) which are driven by a left cutter lifting motor (10) and synchronously swing front and back, the left end and the right end of a front scraper (5) are arranged at the front ends of the left cutter scraping frame (11) and the right end of a back scraper (7) are arranged at the rear ends of the left cutter scraping frame (11) and the right cutter scraping frame (11).

3. The electron beam powder bed additive manufacturing vibratory powdering device of claim 2, wherein: the left scraper frame (11) and the right scraper frame (11) are provided with sensors (12) for monitoring whether the front scrapers (5) and the rear scrapers (7) lift the scrapers or not.

4. The electron beam powder bed additive manufacturing vibratory dusting device of any one of claims 1 to 3, characterized in that: and the front end and the rear end of the powder paving platform (1) are provided with limit switches (13) for preventing the powder paving mechanism from overtravel running.

5. The electron beam powder bed additive manufacturing vibratory dusting device of any one of claims 1 to 3, characterized in that: each scraper comprises a knife plate (16), a scraper blade (17) and a pressing strip (18), and the scraper blade (17) is clamped on the knife plate (16) by the pressing strip (18).

6. The electron beam powder bed additive manufacturing vibratory powdering device of claim 5, wherein: the scraping blades (17) of the front and the rear scrapers (5, 7) are thin plates or thin sheets, and the scraping blade (17) of the middle scraper (6) is a comb-tooth-shaped thin plate or thin sheet.

7. The electron beam powder bed additive manufacturing vibratory dusting device of any one of claims 1 to 3, characterized in that: the vibrator (9) is an ultrasonic vibrator.

8. The electron beam powder bed additive manufacturing vibratory dusting device of any one of claims 1 to 3, characterized in that: the transmission mechanism comprises a left synchronous belt transmission pair (14) and a right synchronous belt transmission pair (14) which are respectively connected with a left moving frame (8) and a right moving frame (8), and the left moving frame and the right moving frame (8) are respectively installed on a left guide rod (15) and a right guide rod (15) in a sliding mode.

Technical Field

The invention relates to powder paving technical equipment, in particular to an electron beam powder bed vibration type powder paving device for additive manufacturing.

Background

The powder spreading technology is a new technology developed recently, and the flowability of the powder is utilized to present a flat and fine powder surface under the action of a certain driving force. With the development of science and technology, the powder spreading technology is widely applied to the field of powder forming and is also one of important forming processes in the field of fused powder 3D printing.

The powder spreading process is generally to scrape and push loose particles falling freely from a powder box, and then to make the particles randomly stacked in a specified flaky space by virtue of the fluidity of the particle group. In the theory of particle population stacking as mentioned in materials science and engineering, there are two equilibrium states possible inside a stationary particle population: firstly, the particles with certain volume are all dropped on the positions of the pores to ensure that the occupied space is in a minimum state, and secondly, the instantaneous equilibrium state caused by dislocation necessarily exists in the particle groups, and even though the particles are packed most closely, the particle groups have about 26 percent of four-octahedron gaps and octahedron gaps. The electrostatic, polarization of those voids and particles severely hamper the conductive circuit to the conductive system or during the electron beam powdering process, causing the soot layer to collapse and be difficult to shape.

In recent years, a plurality of devices for spreading powder are proposed in magazines, journals and reviews at home and abroad, and the devices are mainly divided into the following devices:

1. the micro-jet powder spreading device has a complex mechanism and loose powder falling, and the design of a spray head of the micro-jet powder spreading device usually needs a large amount of manpower and financial resources.

2. The rotary drum type powder spreading device has certain compactibility but can cause local position stress concentration, and workpieces are easy to crack in the electron beam powder melting sintering process.

3. The powder outlet effect is not ideal when the hopper type powder spreading device is moved.

4. Scraper blade formula shop powder device for the most common shop powder mode in powder bed powder melting shop powder field, gives the scraper blade various inclination for improving compaction effect, nevertheless touches large granule powder in the actual process, especially to electron beam powder melting printing powder shop powder, the scraper blade of taking the inclination moves about jumped very obviously vertically, causes the powder granule crowd extremely loose.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the vibration type powder paving device for the additive manufacturing of the electron beam powder bed, which solves the problems of electric shock type electrostatic scattering and excessive forming collapse caused by loose powder particle groups in the conventional scraper type powder paving device.

Can solve above-mentioned technical problem's electron beam powder bed vibration type shop powder device of vibration material disk, its technical scheme includes based on shop's unloading mechanism that the powder platform set up, shop's powder mechanism and forming mechanism, the different is:

1. the blanking mechanism comprises a front powder filling box and a rear powder filling box, and powder outlets of the front powder filling box and the rear powder filling box are respectively positioned above the front part and the rear part of the powder paving platform.

2. Spread powder mechanism and include preceding scraper, well scraper and back scraper, preceding, well, back scraper pass through moving mechanism and install in spreading powder platform top, moving mechanism includes and moves the frame in the left and right that spread powder platform preceding, rear end make straight reciprocating motion under drive mechanism drives, well scraper fixed mounting is on left and right removal frame, is equipped with the vibrator on the well scraper, and preceding, back scraper is installed on left and right removal frame through lifting sword mechanism, and when left and right removal frame moved forward, lift sword mechanism and lift preceding scraper and descend the back scraper, and when left and right removal frame moved backward, lift sword mechanism and lift the back scraper and descend the preceding scraper.

3. The forming mechanism comprises a forming cylinder arranged at the bottom of the powder laying platform on the lifting frame, an avoiding opening matched with the forming cylinder is formed in the powder laying platform, and the forming cylinder lifted during forming is parallel and level to the avoiding opening in the powder laying platform.

The structure of the cutter lifting mechanism comprises a left cutter scraping frame and a right cutter scraping frame which are driven by a left cutter lifting motor and a right cutter lifting motor and synchronously swing front and back, wherein the left end and the right end of the front cutter are arranged at the front ends of the left cutter scraping frame and the right cutter scraping frame, and the left end and the right end of the back cutter are arranged at the back ends of the left cutter scraping frame and the right cutter scraping frame.

And furthermore, sensors for monitoring whether the front scraper and the rear scraper lift the scraper or not are arranged on the left scraper frame and the right scraper frame.

In order to prevent the over-travel operation of the powder paving mechanism, limit switches are arranged at the front end and the rear end of the powder paving platform.

One structure of each scraper comprises a knife board, a scraper blade and a pressing strip, wherein the scraper blade is clamped on the knife board by the pressing strip

Preferably, the blades of the front and rear scrapers are thin plates or sheets, and the blades of the middle scraper are comb-tooth-shaped thin plates or sheets.

The vibrator is preferably an ultrasonic vibrator capable of generating vibration in three dimensions.

One structure of the transmission mechanism comprises a left synchronous belt transmission pair and a right synchronous belt transmission pair which are respectively connected with a left moving frame and a right moving frame, and the left moving frame and the right moving frame are respectively installed on a left guide rod and a right guide rod in a sliding mode.

The invention has the beneficial effects that:

1. the vibrating powder spreading device for additive manufacturing of the electron beam powder bed is a combination of a scraper type powder spreading technology and a movable hopper type powder spreading device, and on the basis of the advantages of scraper type powder spreading, the front and rear scrapers of two alternate lifting knives can recycle the powder with the two ends being excessive.

2. In the structure of the invention, the vibration of the middle scraper has a compacting effect on the powder layer and simultaneously enables the small particle powder to be filled into the polyhedral gap formed by the large particle powder, thereby improving the conductivity of the powder layer and further reducing the probability of electrostatic dispersion.

3. In the structure of the invention, when the powder spreading device moves back and forth, the powder is vibrated by the comb-tooth-shaped middle scraper to form a corrugated surface, and is compacted and spread again by the front scraper or the rear scraper.

4. In the structure of the invention, all parts of the front scraper, the middle scraper and the rear scraper are made of metal materials suitable for high-temperature operation, and the installation and the maintenance are very convenient.

5. The invention can destroy the transient balance structures such as dislocation type bridges and stacking fault layers in loose stacking of particle groups, and the like, so that particles with small diameters are filled in polyhedral gaps formed by stacking large particles to improve the density of the particle groups, the particles are fully contacted with one another, and the electrical conductivity of a powder layer is improved, thereby facilitating a series of work such as fused powder forming in the additive manufacturing of electron beam powder beds.

Drawings

FIG. 1 is an isometric view of one embodiment of the present invention.

Fig. 2 is a front view of the embodiment of fig. 1.

Fig. 3 is an isometric view of the powder spreading mechanism of fig. 1 and 2.

And (3) identifying the figure number: 1. a powder laying platform; 2. a powder box is arranged in front; 3. then powder is put into a powder box; 4. a forming cylinder; 4-1, forming a workpiece cavity; 5. a front scraper; 6. a middle scraper; 7. a rear scraper; 8. a movable frame; 9. a vibrator; 10. a cutter lifting motor; 11. a doctor holder; 12. a sensor; 13. a limit switch; 14. a synchronous belt transmission pair; 15. a guide bar; 16. a cutting board; 17. scraping a blade; 18. layering; 19. a rack; 20. a lifting frame; 21. a substrate; 22. a motor reducer; 23. an insulating plate.

Detailed Description

The technical solution of the present invention will be further explained with reference to the embodiments shown in the drawings.

The invention discloses an electron beam powder bed additive manufacturing vibration type powder paving device which comprises a powder paving platform 1, and a blanking mechanism, a powder paving mechanism and a forming mechanism which are arranged on the basis of the powder paving platform 1.

Spread powder platform 1 (rectangular plate body) level and set up on rack 19, spread the length direction of powder platform 1 and be preceding, rear direction, width direction is left and right direction, spreads the central authorities of powder platform 1 and has seted up the shaping jar and dodge the mouth, as shown in fig. 1, fig. 2.

The blanking mechanism comprises a front powder filling box 2 and a rear powder filling box 3, the front powder filling box 2 and the rear powder filling box 3 are respectively arranged above the front end and the rear end of the powder spreading platform 1, and powder outlets of the front powder filling box 2 and the rear powder filling box 3 are respectively arranged above the front part and the rear part of the powder spreading platform 1, as shown in fig. 2.

The forming mechanism is arranged at the central position below the powder laying platform 1 and comprises a forming cylinder 4 which is arranged on a lifting frame 20 through a base plate 21 and an insulating plate 23, the base plate 21 and the lifting frame 20 are connected through a conducting wire in order to form a conducting loop of an electron beam, a workpiece forming cavity 4-1 is formed in the cylinder body of the forming cylinder 4, the lifting frame 20 drives the forming cylinder 4 to rise and fall, and the end face of the cylinder body of the forming cylinder 4 is matched in a forming cylinder avoiding opening of the powder laying platform 1 and is flush with the table top of the powder laying platform 1 at the upper limit position where the forming cylinder 4 rises, as shown in figure 2.

The powder spreading mechanism comprises a front scraper 5, a middle scraper 6, a rear scraper 7 and guide rods 15 arranged on the left side and the right side of the powder spreading platform 1, the left guide rod 15 and the right guide rod 15 (in the front direction and the rear direction) are respectively sleeved with a left moving frame 8 and a right moving frame 8 in a sliding manner, the left moving frame 8 and the right moving frame 8 are respectively connected with a left synchronous belt transmission pair 14 and a right synchronous belt transmission pair 14 arranged on the left side and the right side of the powder spreading platform 1, and the left synchronous belt transmission pair 14 and the right synchronous belt transmission pair 14 drive the left moving frame 8 and the right moving frame 8 to synchronously move back and forth on the left guide rod 15 and the right guide rod 15 under the driving of a; the middle scraper 6 is vertically arranged in the left and right directions and comprises a corresponding knife plate 16, a scraper 17 and a pressing strip 18, the pressing strip 18 clamps the scraper 17 on the knife plate 16, the scraper 17 is a comb-tooth-shaped thin plate or a thin sheet made of metal materials, the middle part of the left and right movable frame 8 is arranged at the left and right ends of the middle scraper 6 through the knife plate 16, and the lower end of the scraper 17 after installation and the table top of the powder laying platform 1 are kept in a powder laying gap, as shown in fig. 1 and 3.

The front scraper 5 is vertically arranged in the left and right directions and comprises a corresponding knife plate 16, a scraper 17 and a pressing strip 18, the lower part of the knife plate 16 is a wedge angle inclined forwards and downwards, the scraper 17 is clamped on one side surface of the knife plate 16 by the pressing strip 18, the other side surface of the knife plate 16 is provided with an ultrasonic vibrator 9, and the scraper 17 is a thin plate or a sheet made of a metal material; the rear scraper 7 is vertically arranged in the left and right directions and comprises a corresponding knife plate 16, a scraper 17 and a pressing strip 18, the lower part of the knife plate 16 is a wedge angle inclined towards the rear and the lower part, the scraper 17 is clamped on the knife plate 16 by the pressing strip 18, and the scraper 17 is a thin plate or a thin sheet made of a metal material, as shown in fig. 3.

A left scraper frame 11 is arranged on the left moving frame 8, a front suspender and a rear suspender are respectively arranged on the right end surface of the left scraper frame 11, the lower part of the left end of the left scraper frame 11 is arranged on an output shaft of a left cutter lifting motor 10, and the left cutter lifting motor 10 is arranged on the left end surface of the left moving frame 8 through a motor base; a right scraper holder 11 is arranged on the right movable frame 8, a front boom and a rear boom are respectively mounted on the left end face of the right scraper holder 11, the lower portion of the right end of the right scraper holder 11 is mounted on an output shaft of a right cutter lifting motor 10, and the right cutter lifting motor 10 is mounted on the right end face of the right movable frame 8 through a motor base, as shown in fig. 1 and 3.

Preceding scraper 5 is installed on the preceding jib of left and right scraper frame 11 through corresponding cutting board 16, and is specific: the left and right upper ends of the cutting board 16 are respectively hinged at the lower ends of the left and right front suspension rods; the rear scraper 7 is installed on the rear suspender of the left scraper holder 11 and the right scraper holder 11 through the corresponding knife board 16, and is specific: the left and right upper ends of the cutting board 16 are respectively hinged at the lower ends of the left and right rear suspension rods; the left and right knife lifting motors 10 synchronously drive the left and right knife holders 11 to swing front and back, the left and right knife holders 11 swing forward while falling the front scraper 5 and lifting the rear scraper 7, the lower end of the scraper 17 of the falling front scraper 5 butts against the table top of the powder laying platform 1, the left and right knife holders 11 swing backward while falling the rear scraper 7 and lifting the front scraper 5, the lower end of the scraper 17 of the falling rear scraper 7 butts against the table top of the powder laying platform 1, and the front and rear side surfaces of the left and right moving holders 8 are respectively provided with sensors 12 for monitoring whether the front and rear scrapers 5 and 7 lift the knives, as shown in fig. 1 and fig. 3.

The method comprises the following operation steps:

1. the transmission mechanism moves the powder spreading mechanism to the front end of the powder spreading platform 1 (the front end of the powder spreading platform 1 is provided with a limit switch 13 for preventing the powder spreading mechanism from moving out of the powder spreading platform 1 forwards), the front powder loading box 2 discharges powder on the powder spreading platform 1 behind the powder spreading mechanism, and the rear scraper 7 is lifted and the front scraper 5 falls.

2. The forming cylinder 4 is raised flush on the table of the dusting table 1.

3. The transmission mechanism drives the powder spreading mechanism to move from the front end to the rear end, the vibrating middle scraper 6 contacts with the powder firstly, and the front scraper 5 contacts with the powder (is dragged and pressed on the powder) backwards towards the lower end of the scraping piece 17 inclined towards the front lower part, so that the powder discharged from the front powder box 2 is spread.

4. While passing through the forming cylinder 4, the powder laying mechanism lays powder in the workpiece forming chamber 4-1 of the forming cylinder 4.

5. The powder spreading mechanism continuously moves backwards to the rear end of the powder spreading platform 1 (the rear end of the powder spreading platform 1 is provided with a limit switch 13 for preventing the powder spreading mechanism from moving backwards out of the powder spreading platform 1), the front scraper 5 is lifted, and the rear scraper 7 falls.

6. And the rear powder loading box 3 is used for discharging powder on the powder spreading platform 1 in front of the powder spreading mechanism.

7. The transmission mechanism drives the powder spreading mechanism to move from the rear end to the front end, the vibrating middle scraper 6 contacts with powder firstly, and then the vibrating middle scraper 7 contacts with the powder (is dragged and pressed on the powder) backwards at the lower end of the scraping piece 17 inclined backwards and downwards, so that the powder discharged by the rear powder box 3 and the powder remained in the previous time are spread.

8. While passing through the forming cylinder 4, the powder laying mechanism lays powder in the workpiece forming chamber 4-1 of the forming cylinder 4.

9. The transmission mechanism drives the powder spreading mechanism to continuously move forwards to the front end of the powder spreading platform 1 so as to realize one-time reciprocating type vibration powder spreading.

10. The transmission mechanism drives the powder paving mechanism to operate according to the steps 1-9 repeatedly until the powder is completely paved in the workpiece forming cavity 4-1.