CN110153419B

CN110153419B - Liquid level environment 3D printing mechanism

Info

Publication number: CN110153419B
Application number: CN201910463432.9A
Authority: CN
Inventors: 谢兆贤; 倪建成; 乔鑫; 林莉莎; 陆思诺; 高峰
Original assignee: Qufu Normal University
Current assignee: Qufu Normal University
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2021-04-27
Anticipated expiration: 2039-05-30
Also published as: CN110153419A

Abstract

The invention belongs to the technical field of machining, and particularly relates to a liquid level environment 3D printing mechanism which comprises a working liquid tank, a lifting platform, a driving device, an operation device and a powder spreading device, wherein the lifting platform comprises a working table surface positioned in the working liquid tank, a laser machining head and an electric discharge machining head are arranged on a working assembly, insulating machining liquid is injected into the working liquid tank, and the driving device drives the lifting platform to move up and down relative to the working liquid tank so that a laser machining interface of the laser machining head is kept below the liquid level. The working environment of the 3D printing mechanism is a liquid level environment, so that the metal powder can be prevented from being oxidized due to temperature rise caused by laser irradiation in the processing process; the heat can be quickly dissipated; meanwhile, the insulating processing liquid provides a liquid medium for discharging, and in addition, the invention integrates the functions of metal laser 3D printing, discharging processing, laser cutting and laser welding on the laser processing head and the discharging processing head, thereby realizing the possibility that one mechanism carries out multiple processing modes.

Description

Liquid level environment 3D printing mechanism

Technical Field

The invention belongs to the technical field of machining, and particularly relates to a liquid level environment 3D printing mechanism.

Background

The traditional metal laser 3D printer processes parts and parts in the air for molding, and the possible influence on the precision of a workpiece caused by the fact that the metal powder is oxidized due to overhigh temperature due to laser irradiation cannot be avoided. In addition, the traditional metal laser 3D printer only has a 3D printing single function and cannot perform subsequent finish machining on a workpiece.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art and provide a liquid level environment 3D printing mechanism.

The technical scheme adopted by the invention is as follows: the utility model provides a liquid level environment 3D printing mechanism, includes work cistern, elevating platform, drive arrangement, operation device, shop's powder device, the elevating platform is including the table surface who is located the work cistern, be provided with laser beam machining head and discharge machining head on the operation device, shop's powder device relative table surface displacement and spread to table surface and send raw materials powder, inject insulating processing liquid in the work cistern, drive arrangement drive elevating platform relative work cistern reciprocates and makes the laser beam machining interface of laser beam machining head keep in the liquid level below.

The operation device comprises a base and a multi-degree-of-freedom mechanical arm connected to the base, the laser processing head and the discharge processing head are arranged at the end part of the multi-degree-of-freedom mechanical arm, and the base is connected with the upper edge of the working liquid tank and is matched with the working liquid tank in a sliding mode.

The working devices are two or three and are respectively arranged at two or three upper edges of the working liquid tank.

Spread the powder device and include the shop powder working face of making by transparent material, shop powder dolly, set up the shop powder ware on spreading the powder dolly with the working solution groove grafting, be equipped with a plurality of through-holes on spreading the powder working face, shop powder dolly sets up and freely moves on spreading the powder working face, shop powder ware spreads to send raw materials powder to table surface through the through-hole.

The operation device slides complex X axle slider, Y axle slide rail with X axle slide rail fixed connection, slides complex Y axle slider, the Z axle drive arrangement who is connected with Y axle slider including being located the outside X axle slide rail of work cistern both sides, with X axle slide rail, the spout that supplies Y axle slide rail to pass is equipped with to the lateral wall of work cistern both sides, Y axle slider, Z axle drive arrangement all are located the work cistern, and laser processing head and discharge machining head set up the lower tip at Z axle drive arrangement.

The operation device is provided with at least two devices which are arranged up and down.

Spread the powder device including be located the outside X axle slide rail of work cistern both sides, with X axle slide rail matched with X axle slider that slides, with X axle slider fixed connection's Y axle slide rail, with Y axle slide rail matched with Y axle slider that slides, spread the powder ware with Y axle slider is connected, work cistern both sides lateral wall is equipped with the spout that supplies Y axle slide rail to pass, Y axle slider, shop powder ware all are located the work cistern, spread the powder device setting in operation device below.

The invention has the following beneficial effects: the working environment of the 3D printing mechanism is that the printing mechanism is processed and molded in the liquid level environment of the insulating processing liquid, so that the metal powder can be prevented from being oxidized due to the temperature rise caused by the irradiation of laser on the metal powder in the processing process; but also can quickly dissipate heat through contact with the working solution; meanwhile, the insulating processing liquid provides a liquid medium for the discharging process, and in addition, the metal laser 3D printing, discharging processing, laser cutting and laser welding functions are integrated on the laser processing head and the discharging processing head, so that the possibility that one mechanism carries out multiple processing modes is realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is within the scope of the present invention for those skilled in the art to obtain other drawings based on the drawings without inventive exercise.

FIG. 1 is a schematic structural view of example 1;

FIG. 2 is a schematic view showing the construction of a working liquid bath in example 1;

FIG. 3 is a schematic structural diagram of the lifting platform;

FIG. 4 is a schematic flow diagram of a single axis single task;

FIG. 5 is a schematic flow diagram of single axis multitasking;

FIG. 6 is a schematic flow diagram of a multi-axis single task;

FIG. 7 is a schematic flow diagram of multi-axis multitasking;

FIG. 8 is a top view of example 2;

FIG. 9 is a side view of the working liquid bath in example 2;

in the figure, 1, the working fluid bath; 101, a chute; 102, a gap; 2, a lifting platform; 201, a work table; 202, a connecting plate; 203, a drive connection; 3, a driving device; 4, a working device; 401, a base; 402, a multi-degree-of-freedom mechanical arm; 6, a powder spreading device; 601, paving a powder working face; 602, a via hole; 603, spreading a powder trolley; 604, a powder spreader; 7, processing a laser head; 8, an electric discharge machining head; 9, an X-axis slide rail; 10, an X-axis slide; 11, Y-axis slide rails; 12, a Y-axis slider; 13, a Z-axis driving device; and 14, pulse power supply.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

The terms of direction and position of the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "top", "bottom", "side", etc., refer to the direction and position of the attached drawings. Accordingly, the use of directional and positional terms is intended to illustrate and understand the present invention and is not intended to limit the scope of the present invention.

Example 1:

as shown in fig. 1, a liquid level environment 3D printing mechanism includes the following structures:

the working liquid tank 1 is a square container, insulating processing liquid is filled in the working liquid tank, and a liquid working environment is provided for laser 3D printing, discharge machining, laser cutting and laser welding;

the lifting platform 2, as shown in fig. 3, comprises a working platform 201, a driving connection part 203 and a connection plate 202 connecting the working platform 201 and the driving connection part 203, wherein the working platform 201 is located in the working fluid tank 1, the driving connection part 203 is located at the side edge above the working fluid tank 1, the driving connection part 203 is connected with a driving device 3, and the working platform 201 can move up and down relative to the working fluid tank 1 by the driving of the driving device 3;

the working device 4 comprises two groups, each group distributed on two side edges of the working liquid tank 1 comprises a base 401 and a multi-degree-of-freedom mechanical arm 402, a laser processing head 7 and a discharge processing head 8 are arranged at the end part of the multi-degree-of-freedom mechanical arm 402, the multi-degree-of-freedom mechanical arm 402 is formed by sequentially connecting a plurality of arms, and the arms are connected through a waterproof rotary joint structure to form the multi-degree-of-freedom mechanical arm structure. The waterproof rotary joint structure between the arms in the multi-degree-of-freedom mechanical arm 402 can adopt a joint group part structure disclosed in a patent CN201720400385.X, so that the free rotation is realized and the capability of working under the liquid surface is realized; one or more arms in the multi-degree-of-freedom mechanical arm 402 may adopt a hydraulic cylinder with a telescopic structure, so that the attitude can be adjusted conveniently to enable the laser processing head 7 and the discharge processing head 8 to process along a target path;

spread powder device 6, include the shop powder working face 601, shop powder dolly 603, the shop powder ware of setting on shop powder dolly 603 of making by transparent material with work fluid bath 1 grafting, be equipped with a plurality of through-holes 602 on shop powder working face 601, shop powder dolly 603 sets up and freely moves on shop powder working face 601, shop powder ware spreads to send raw material powder to table surface 201 through-hole 602. The powder paving device 6 can evenly pave metal powder according to the shape of the part. The powder paving working surface 601 is a moving interface of the powder paving trolley and is also a forming interface for 3D printing;

the pulse power supply 14 is connected to the working platform 201 in a positive stage, the discharge machining head 8 is connected to the negative electrode, when the discharge machining is realized, the working device 4 moves to enable the discharge machining head 8 to move to a corresponding position, namely, the discharge machining head 8 and a workpiece maintain a small discharge gap, the pulse power supply applies voltage between the two electrodes, and the liquid medium at the closest point of the electrodes under the current condition is broken down to form a discharge channel. The sectional area of the channel is very small, the discharge time is very short, so that the energy is highly concentrated, and the instantaneous high temperature generated in the discharge area is enough to melt and even evaporate the material, so that the method can be used for accurately machining the hole and the cavity in the metal workpiece formed by 3D printing.

The insulating processing liquid can be deionized water, kerosene, mineral oil and other liquid media (10-10) with certain insulating strength⁷Ω · m). The working fluid bath 1 can be connected to a purification device in which a porous adsorption material is arranged, and the insulating working fluid is caused to flow through the purification device during or after the electric discharge machining.

The driving device 3 is configured to be lifted and lowered by screw threads, and may be hydraulically lifted and lowered.

During laser processing, the powder spreading working surface 601 is inserted in the notch 102 of the working liquid tank 1, the lifting platform moves to a specified height, then the powder spreading trolley moves on the powder spreading working surface along the position of a part entity, metal powder is uniformly spread, and the laser processing head of the mechanical arm is adjusted to a proper position to continuously emit ultraviolet light with a specific wavelength for a plurality of times, so that the metal powder is melted, sintered, formed and cooled.

During discharge machining, the powder laying working surface 601 is taken out of the working liquid tank 1, the lifting table and the mechanical arm are adjusted to appropriate positions, the corresponding positions of the discharge machining head and the 3D printed workpiece are made to be close to each other as far as possible, and current is emitted continuously for a period of time.

The processing flow of the laser cutting and welding function is similar to the working flow of the discharge head.

The two groups of working devices 4 can realize four processing modes under the coordination operation: single-axis single-task, single-axis multi-task, multi-axis single-task, multi-axis multi-task, that is, two sets of working devices 4 can simultaneously perform machining of a single workpiece or machining of two workpieces. Specifically, the following setting may be made:

let S be the number of axes involved in the work, W be the workload of the work (i.e., the number of parts processed simultaneously), and M be the work mode. Further, S0 denotes the first working device 4 arm, and S1 denotes the second working device 4.

Wherein the content of the first and second substances,

s =1 indicates that the number of axes participating in the work is 1, and S =2 indicates that the number of axes participating in the work is 2;

w =1 indicates that the task amount of work is 1, and W =2 indicates that the task amount of work is 2;

m =0 denotes a laser 3D metal printing mode, M =1 denotes an electric discharge machining mode, M =2 denotes a laser cutting mode (selective laser sintering, i.e., SLS), and M =3 denotes a laser welding mode.

Since the operation flow is similar to that when M =0 and is relatively simple when M =1 or M =2 or M =3, we assume here that M = 0.

(1) Situation one

When S =1 and W =1, as shown in fig. 4, the operator puts the whole mechanism in a stable working environment, inputs a part (a part) to be machined including all the dimensions and precision requirements thereof at the computer terminal, and injects a specific liquid into the working liquid tank to the scale mark, and the system automatically performs multiple machining rounds. In each round of processing, the lifting platform descends by one layer with the thickness of 2mm, the powder laying trolley uniformly lays metal powder with the thickness of 2mm according to the shape of the workpiece, the first operation device continuously adjusts the proper posture, the laser irradiation is carried out along the powder laying path, the workpiece is cooled for a period of time after each round of processing, and then the next round of processing is carried out until the whole workpiece is processed.

(2) Situation two

When S =2 and W =1, as shown in fig. 5, the operator puts the whole mechanism in a stable working environment, inputs a part (a part) to be machined including all the dimensions and precision requirements thereof at the computer terminal, and injects a specific liquid into the working liquid tank to the scale mark, and the system automatically performs multiple machining rounds. In each round of processing, the lifting platform descends by 2mm, the powder laying trolley uniformly lays metal powder with the thickness of 2mm according to the shape of the workpiece, the first operating device and the second operating device continuously adjust proper postures to carry out laser irradiation to the middle point of the powder laying path along the two ends of the powder laying path, the powder laying path is cooled for a period of time after each round of processing, and then the next round of processing is carried out until the whole workpiece is processed.

(3) Situation three

When S =1 and W =2, as shown in fig. 6, the operator puts the entire mechanism in a stable working environment, inputs the parts (two parts) to be machined including all the dimensions and precision requirements thereof at the computer terminal, and injects a specific liquid into the working liquid tank to the scale lines, and the system automatically performs multiple machining cycles. In each round of processing, the lifting platform descends by 2mm, the powder spreading trolley uniformly spreads metal powder with the thickness of 2mm according to the shape of a first workpiece, the first operation device continuously adjusts the proper posture, laser irradiation is carried out along the powder spreading path, the powder is cooled for a period of time after each round of processing, and then the next round of processing is carried out until the first workpiece is processed. The second workpiece is then machined, the elevator table is raised to the maximum, and the next steps are the same as machining the first part. And finally, taking out the two parts.

(4) Situation four

When S =2 and W =2, as shown in fig. 7, the operator puts the entire mechanism in a stable working environment, inputs the parts (two parts) to be machined, including all the dimensions and precision requirements thereof, at the computer terminal, and injects a specific liquid into the working liquid tank to the scale marks, and the system automatically performs multiple machining cycles. In each round of processing, the lifting platform descends by 2mm, the powder laying trolley uniformly lays metal powder with the thickness of 2mm on two half planes of the lifting platform according to the shapes of the first workpiece and the second workpiece, the first operation device and the second operation device continuously adjust proper postures to respectively perform laser irradiation along powder laying paths of the two parts, the first operation device and the second operation device are cooled for a period of time after each round of processing, and then the next round of processing is performed until the two workpieces are all processed. And finally, taking out the two parts.

Example 2:

as shown in fig. 8 and 9, the difference from embodiment 1 is that the working device and the powder spreading device have different structures. The method comprises the following specific steps:

the operation device 4 is including being located the X axle slide rail 9 outside the work cistern 1 both sides, with X axle slide rail 9 complex X axle slider 10 that slides, with X axle slider 10 fixed connection's Y axle slide rail 11, with Y axle slide rail 11 complex Y axle slider 12 that slides, the Z axle drive arrangement 13 of being connected with Y axle slider 12, the lateral wall of work cistern 1 both sides is equipped with the spout 101 that supplies Y axle slide rail 11 to pass, Y axle slider 12, Z axle drive arrangement 13 all are located work cistern 1, and laser beam machining head 7 and discharge machining head 8 set up the lower tip at Z axle drive arrangement 13. The Z-axis driving device 13 may adopt a driving structure of a sliding rail and a sliding block, or may adopt a driving structure of a multi-stage telescopic hydraulic cylinder, or other telescopic driving structures, such as a waterproof multi-stage telescopic rod disclosed in patent CN 201110368864.5. Compared with the structure of embodiment 1, this embodiment has an advantage that it is easy to control, and the laser processing head 7 and the discharge processing head 8 can be accurately moved to the target position by the three coordinate data of x, y, z of the target processing position.

The working devices 4 are arranged at least two and are arranged up and down.

Spread the powder device including being located outside work cistern 1 both sides X axle slide rail 9, with X axle slide rail 9 complex X axle slider 10 that slides, with X axle slider 10 fixed connection's Y axle slide rail 11, with Y axle slide rail 11 complex Y axle slider 12 that slides, spread powder ware 604 with Y axle slider 12 connection, work cistern 1 both sides lateral wall is equipped with the spout 101 that supplies Y axle slide rail 11 to pass, Y axle slider 12, spread powder ware 604 and all be located work cistern 1, spread the powder device setting in operation device 4 below.

As shown in fig. 9, the two side walls of the working liquid tank 1 are provided with three parallel chutes 101, the upper two chutes 101 are used for installing the working device 4, and the lower chute 101 is used for installing the powder spreading device.

It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by relevant hardware instructed by a program, and the program may be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. The utility model provides a liquid level environment 3D printing mechanism which characterized in that: the device comprises a working liquid tank (1), a lifting platform (2), a driving device (3), an operating device (4) and a powder paving device (6), wherein the lifting platform (2) comprises a working table top (201) positioned in the working liquid tank (1), the operating device (4) is provided with a laser processing head (7) and a discharge processing head (8), the powder paving device is displaced relative to the working table top (201) and paves and conveys raw material powder to the working table top (201), insulating processing liquid is injected into the working liquid tank (1), and the driving device (3) drives the lifting platform (2) to move up and down relative to the working liquid tank (1) so that a laser processing interface of the laser processing head (7) is kept below the liquid level;

the working device (4) comprises a base (401) and a multi-degree-of-freedom mechanical arm (402) connected to the base (401), the laser processing head (7) and the discharge processing head (8) are arranged at the end part of the multi-degree-of-freedom mechanical arm (402), and the base (401) is connected with the upper edge of the working liquid tank (1) and is in sliding fit with the upper edge;

spread the powder device and include the shop powder working face (601), shop powder dolly (603) that make by transparent material of pegging graft with work fluid bath (1), set up the shop powder ware on shop powder dolly (603), be equipped with a plurality of through-holes (602) on shop powder working face (601), shop powder dolly (603) set up and freely move on shop powder working face (601), shop powder ware spreads to send raw materials powder to table surface (201) through-hole (602).

2. A meniscus environment 3D printing mechanism according to claim 1, wherein: the two or three working devices (4) are respectively arranged at the two or three upper edges of the working liquid tank (1).

3. A meniscus environment 3D printing mechanism according to claim 1, wherein: operation device (4) including being located outside work cistern (1) both sides X axle slide rail (9), with X axle slide rail (9) complex X axle slider (10) that slides, with Y axle slide rail (11) of X axle slider (10) fixed connection, with Y axle slide rail (11) complex Y axle slider (12) that slides, Z axle drive arrangement (13) of being connected with Y axle slider (12), work cistern (1) both sides lateral wall is equipped with spout (101) that supply Y axle slide rail (11) to pass, Y axle slider (12), Z axle drive arrangement (13) all are located work cistern (1), and laser beam machining head (7) and discharge machining head (8) set up the lower tip at Z axle drive arrangement (13).

4. A meniscus environment 3D printing mechanism according to claim 3, wherein: the operation devices (4) are arranged at least two and are arranged up and down.