Powder bed laser melting forming technology equipment for various metal forming

Abstract

The invention discloses a powder bed laser melting forming technology equipment for forming various metals, including a forming chamber, a forming cylinder, a powder discharge cylinder, a forming cylinder driving device and a powder container. The forming cylinder can be longitudinally lifted and lowered and is arranged below the forming chamber. The forming cylinder driving device drives the cylinder body of the forming cylinder to lift and lower, and the upper end of the cylinder body of the forming cylinder can be in close contact with the lower surface of the bottom plate of the forming chamber. The piston in the forming cylinder is actively and sealably inserted into the powder inlet on the bottom plate of the forming chamber, and the upper end of the powder discharge cylinder is sealed and fixed to the lower side surface of the bottom plate of the forming chamber. The side wall of the powder discharge cylinder is provided with at least one powder discharge channel penetrating along the radial direction thereof, and the powder discharge cylinder sleeve is arranged on the outer side of the forming cylinder insert, and the outer wall of the forming cylinder is in close contact with the inner wall of the powder discharge cylinder. When the cylinder body of the forming cylinder descends, the powder in the forming cylinder can be connected with the inlet of the powder discharge channel, and the outlet of the powder discharge channel is connected with the inlet of the powder container. The invention realizes the laser melting forming of metal powders of various materials and forms formed parts with various materials.

Description

Technical Field

[0001] The invention relates to a laser melting technology, in particular to a powder bed laser melting forming technology equipment used for forming a variety of metals. Background Art

[0002] SLM is the most mature, stable, common and popular additive manufacturing method used in industrial production today.

[0003] At present, SLM equipment has a forming cylinder fixedly installed under the forming chamber. The piston in the forming cylinder is moved in an inch motion to add powder layer by layer, and then the laser cladding processing is carried out layer by layer. This results in the formed product only being formed with one kind of metal powder, and it is impossible to achieve the splicing of multiple materials. The formed product has a single material. Some products that require multiple materials cannot be formed, which limits the use of SLM processing technology. Summary of the invention

[0004] In order to make up for the above shortcomings, the present invention provides a powder bed laser melting forming technology equipment for forming a variety of metals, and the powder bed laser melting forming technology equipment for forming a variety of metals can realize laser melting forming of products composed of a variety of materials.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a powder bed laser melting forming technology equipment for forming various metals, including a forming chamber, a forming cylinder, a powder discharge cylinder, a forming cylinder driving device and a powder container. The forming cylinder can be longitudinally lifted and lowered and is arranged below the forming chamber. The forming cylinder driving device drives the cylinder body of the forming cylinder to lift and lower. The upper end of the cylinder body of the forming cylinder can be in close contact with the lower surface of the bottom plate of the forming chamber. The piston in the forming cylinder can be dynamically sealed and inserted into the powder inlet on the bottom plate of the forming chamber. The upper end of the powder discharge cylinder is sealed and fixedly positioned with the lower side surface of the bottom plate of the forming chamber. The side wall of the powder discharge cylinder is provided with at least one powder discharge channel penetrating along the radial direction thereof. The powder discharge cylinder sleeve is arranged on the outside of the forming cylinder insert, and the outer wall of the forming cylinder is in close contact with the inner wall of the powder discharge cylinder. The lowering of the cylinder body of the forming cylinder can make the powder inside it communicate with the inlet of the powder discharge channel, and the outlet of the powder discharge channel is communicated with the inlet of the powder container.

[0006] As a further improvement of the invention, at least one radial groove extending longitudinally is provided on the inner wall of the powder discharge cylinder, the upper end of the radial groove passes through the upper end surface of the powder discharge cylinder, and the lower end of the radial groove is connected to the inlet of the powder discharge channel.

[0007] As a further improvement of the invention, the radial grooves on the inner wall of the powder discharge cylinder are evenly spaced along the circumferential direction of the powder discharge cylinder, and the powder discharge channel is also evenly spaced along the circumferential direction of the powder discharge cylinder. The radial grooves are connected to the powder discharge channel one by one, and the radial grooves form the inlet of the powder discharge channel.

[0008] As a further improvement of the invention, a powder outlet pipe is installed at the outlet of the powder discharge channel, the outlet of the powder outlet pipe is directly opposite to the powder container, and a powder discharge valve is installed on the powder outlet pipe, which can open and close the powder outlet pipe.

[0009] As a further improvement of the invention, at least one powder discharge channel extending radially is provided on the upper end surface of the cylinder body of the forming cylinder, one end of the powder discharge channel is connected with the interior of the forming cylinder, and the other end of the powder discharge channel can be connected one-to-one with the inlet of the powder discharge channel on the side wall of the powder discharge cylinder as the forming cylinder descends.

[0010] As a further improvement of the invention, the powder discharge channel is an inclined structure in which the height of one end facing the inner side of the powder discharge cylinder is higher than the height of one end facing the outer side of the powder discharge cylinder.

[0011] As a further improvement of the invention, an outer cylinder is further provided, the upper end of the outer cylinder is fixedly sleeved on the outer side of the lower end of the powder discharge cylinder, and a accommodating space for the raising and lowering of the forming cylinder is formed inside the outer cylinder.

[0012] As a further improvement of the invention, the inner wall of the outer cylinder is sealingly connected to the outer wall of the powder discharge cylinder, the outer wall of the forming cylinder is in dynamic sealing contact with the inner wall of the powder discharge cylinder, a sealed space is formed between the outer cylinder, the powder discharge cylinder and the forming cylinder, and an oil circuit or an air circuit connected to the sealed space is also provided on the side wall of the outer cylinder.

[0013] As a further improvement of the invention, a forming bottom plate is further provided on the upper surface of the piston of the forming cylinder. The forming bottom plate can be flush with the bottom surface of the forming chamber, or can be higher than the bottom surface of the forming chamber by a set height.

[0014] As a further improvement of the invention, a frame, a laser melting system, a powder supply device and a powder scraping device are also provided. The forming chamber is fixedly installed on the frame. The powder supply device can supply forming powder to the forming chamber. The powder scraping device can scrape the powder on the bottom plate of the forming chamber into the forming cylinder to form a powder layer of specified thickness. The laser melting system is installed above the forming chamber. The laser melting system can perform laser melting forming on the powder layer in the forming cylinder.

[0015] The beneficial technical effect of the present invention is: the present invention fixes a powder discharge cylinder at the lower end of the forming chamber, seals the forming cylinder in the powder discharge cylinder, and enables the forming cylinder to move up and down to form a double-layer cylinder structure. The powder discharge channel on the side wall of the powder discharge cylinder is opened by the lowering of the forming cylinder to discharge the metal powder in the forming cylinder. This structure can discharge the metal powder in the forming cylinder without taking out the formed part, which is convenient for adding the second powder for laser melting forming again. The present invention realizes laser melting forming of metal powders of various materials through the cooperation of the forming cylinder and the powder discharge cylinder, and finally forms a formed part spliced ​​by various materials, which meets the demand of using different materials in different parts of the formed part and expands the application scope of SLM forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structural principle of the present invention;

[0017] Figure 2 It is a schematic cross-sectional view of a powder discharge cylinder of the present invention;

[0018] Figure 3 The figure is a schematic diagram of the forming process of laser melting two metal powders using the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0020] Embodiment: A powder bed laser melting forming technology equipment for forming various metals, including a forming chamber, a forming cylinder, a powder discharge cylinder 1, a forming cylinder driving device and a powder container 2. The forming cylinder can be longitudinally lifted and lowered and is arranged below the forming chamber. The forming cylinder driving device drives the cylinder body 3 of the forming cylinder to lift and lower. The upper end of the cylinder body 3 of the forming cylinder can be in close contact with the lower surface of the bottom plate 4 of the forming chamber. The piston 5 in the forming cylinder can be dynamically sealed and inserted into the powder inlet on the bottom plate 4 of the forming chamber. The upper end of the powder discharge cylinder 1 is sealed and fixedly positioned with the lower side surface of the bottom plate of the forming chamber. The side wall of the powder discharge cylinder 1 is provided with at least one powder discharge channel 6 that penetrates along its radial direction. The powder discharge cylinder 1 is sleeved on the outside of the forming cylinder insert, and the outer wall of the forming cylinder is in close contact with the inner wall of the powder discharge cylinder 1. The descent of the cylinder body 3 of the forming cylinder can make the powder inside it communicate with the inlet of the powder discharge channel 6, and the outlet of the powder discharge channel 6 is communicated with the inlet of the powder container 2.

[0021] When the equipment performs metal powder forming, the first metal powder 7 can be used for forming to form a partial structure of the product, and then the cylinder body 3 of the forming cylinder can be lowered to a certain height, and the powder discharge channel 6 of the powder discharge cylinder 1 can be opened, and the powder in the forming cylinder can flow along the powder discharge channel 6 to the powder container 2 for collection. During the process of discharging the metal powder in the forming cylinder, the piston 5 in the forming cylinder is also adjusted in height to make it flush with the upper end surface of the forming cylinder, and finally the first metal powder 7 in the forming cylinder is emptied, and then the cylinder body 3 of the forming cylinder is reset to the initial state, and the position of the piston 5 in the forming cylinder is adjusted to a position where the workpiece on it is flush with the upper surface of the bottom plate 4 of the forming chamber. At this time, the second metal powder 8 is added to the forming cylinder for forming. After the second metal powder 8 is formed, the forming cylinder is lowered again to discharge the powder. This can be repeated to achieve a product formed by laser melting of two or more metal powders, which solves the defect that the product can only be processed by laser melting of a single material, so that the product can be composed of a combination of multiple materials to meet the forming requirements of using different materials at different positions of the product.

[0022] At least one radial groove 9 extending in the longitudinal direction is provided on the inner side wall of the powder discharge cylinder 1 , the upper end of the radial groove 9 penetrates the upper end surface of the powder discharge cylinder 1 , and the lower end of the radial groove 9 is connected to the inlet of the powder discharge channel 6 .

[0023] A longitudinally extending radial groove 9 is provided on the inner side wall of the powder discharge cylinder 1, so that the inlet of the powder discharge channel 6 is increased in longitudinal dimension. When discharging powder, the cylinder body 3 of the forming cylinder is always connected with the inlet of the powder discharge channel 6 during the descending process, and the powder discharge is not limited by the thickness of the powder in the forming cylinder. The powder discharge channel 6 of the powder discharge cylinder 1 is preferably provided on the lower side wall of the powder discharge cylinder 1, so that the powder in the forming cylinder can be fully discharged. When discharging powder, the cylinder body 3 of the forming cylinder descends to be flush with its inner piston to avoid powder residue in the forming cylinder.

[0024] The radial grooves 9 on the inner wall of the powder discharge cylinder 1 are evenly spaced along the circumferential direction of the powder discharge cylinder 1, and the powder discharge channels 6 are also evenly spaced along the circumferential direction of the powder discharge cylinder 1. The radial grooves 9 are connected to the powder discharge channels 6 in a one-to-one correspondence, and the radial grooves 9 form the inlet of the powder discharge channels 6. It can realize the simultaneous powder discharge of multiple channels, with high powder discharge efficiency and uniform powder discharge, and can avoid powder residue in the forming cylinder.

[0025] The outlet of the powder discharge channel 6 is also provided with a powder discharge pipe 10, the outlet of the powder discharge pipe 10 is directly opposite to the powder container 2, and a powder discharge valve 11 is provided on the powder discharge pipe 10, and the powder discharge valve 11 can open and close the powder discharge pipe 10. The powder discharge channel 6 is opened and closed by the powder discharge valve 11, and the powder discharge can be effectively controlled.

[0026] At least one powder discharge cross-channel 12 extending in the radial direction is provided on the upper end surface of the cylinder body 3 of the forming cylinder, one end of the powder discharge cross-channel 12 is connected to the inside of the forming cylinder, and the other end of the powder discharge cross-channel 12 can be connected with the inlet of the powder discharge channel 6 on the side wall of the powder discharge cylinder 1 in a one-to-one correspondence as the forming cylinder descends. A groove-shaped powder discharge cross-channel 12 is formed on the upper end surface of the cylinder body 3 of the forming cylinder, so that the forming cylinder and the powder discharge channel 6 of the powder discharge cylinder 1 are always connected. The powder discharge can be controlled by controlling the opening and closing of the powder discharge channel 6 by the powder discharge valve 11. The groove-shaped powder discharge cross-channel 12 is provided on the top of the cylinder body of the forming cylinder, so that powder of any thickness in the forming cylinder can be discharged. At the same time, when discharging powder, it plays a guiding role in the flow of powder in the forming cylinder, so that the powder in the forming cylinder enters the powder discharge channel 6 of the powder discharge cylinder 1 along the powder discharge cross-channel 12 for discharge, thereby avoiding powder residue.

[0027] The powder discharge channel 6 is an inclined structure with a height of one end toward the inner side of the powder discharge cylinder 1 being higher than that of the other end toward the outer side of the powder discharge cylinder 1. The inclined channel can avoid powder residue and enable the powder to be completely discharged.

[0028] An outer cylinder 13 is also provided, the upper end of which is fixedly sleeved on the outer side of the lower end of the powder discharge cylinder 1, and a receiving space for the raising and lowering of the forming cylinder is formed in the outer cylinder 13. On the one hand, the outer cylinder 13 is fixedly connected to the powder discharge cylinder 1 to achieve stable positioning of the powder discharge cylinder 1, and at the same time, the outer cylinder 13 protects and accommodates the forming cylinder.

[0029] The inner wall of the outer cylinder 13 is sealed and connected to the outer wall of the powder discharge cylinder 1, and the outer wall of the forming cylinder is in dynamic sealing contact with the inner wall of the powder discharge cylinder 1. A sealed space is formed between the outer cylinder 13, the powder discharge cylinder 1 and the forming cylinder, and an oil circuit or an air circuit connected to the sealed space is also provided on the side wall of the outer cylinder. The outer cylinder 13 is fixedly connected to the powder discharge cylinder 1 to form a sealed integrated body, and the forming cylinder is sealed and connected to the lower section of the powder discharge channel 6 of the powder discharge cylinder 1, so that the outer cylinder 13 and the powder discharge cylinder 1 form a cylinder structure, and the forming cylinder forms a piston structure. The forming cylinder moves up and down under the action of hydraulic pressure or gas pressure. In addition, the forming cylinder can also be driven to move up and down by other means, such as a motor driving a screw nut mechanism, a motor driving a gear rack transmission mechanism, etc., which are equivalent replacement structures that can be easily thought of by those skilled in the art based on this patent and fall within the scope of protection of this patent.

[0030] The upper surface of the piston of the forming cylinder is also provided with a forming bottom plate 14, which can be flush with the bottom surface of the forming chamber or can be set higher than the bottom surface of the forming chamber. The forming bottom plate 14 is used to support the formed parts, and a slot can be provided on the forming bottom plate 14, so that when taking out the parts, the fork of the forklift is inserted into the slot to take out the forming bottom plate 14 and the formed parts thereon.

[0031] A frame, a laser melting system, a powder supply device and a powder scraping device are also provided. The forming chamber is fixedly installed on the frame. The powder supply device can supply forming powder to the forming chamber. The powder scraping device can scrape the powder on the bottom plate 4 of the forming chamber into the forming cylinder to form a powder layer of a specified thickness. The laser melting system is installed above the forming chamber. The laser melting system can perform laser melting forming on the powder layer in the forming cylinder. When the powder is laser melted and formed, the powder supply device quantitatively and intermittently supplies powder to the forming chamber. The scraper of the powder scraping device reciprocates on the surface of the bottom plate 4 of the forming chamber to scrape the powder into the forming cylinder, forming a powder layer of a set thickness in the forming cylinder. The laser melting system performs laser melting forming on the powder in the forming cylinder.

[0032] The product melting and forming process is as follows:

[0033] Step 1: Forming preparation state;

[0034] Step 2: The first metal powder 7 is used for laser melting forming. With the micro-dropping (inching) of the forming cylinder piston and the intermittent powder supply of the powder supply device, the first material part of the formed part is formed;

[0035] Step 3: the forming cylinder is lowered, and the upper end surface of the cylinder body 3 of the forming cylinder is flush with the piston, and the first metal powder 7 is discharged;

[0036] Step 4: When the first powder is completely discharged, the first metal powder 7 is discharged, the cylinder body 3 of the forming cylinder is raised to a state of being in close contact with the bottom plate 4 of the forming chamber, and the piston of the forming cylinder is adjusted to align the upper molded part with the surface of the bottom plate 4 of the forming chamber;

[0037] Step 5: Add the second metal powder 8 into the forming cylinder and fill the powder with the powder inlet of the forming bottom plate 14;

[0038] Step 6: Use the second metal powder 8 to perform laser cladding forming to complete the forming of the second material part;

[0039] Step 7: After the second metal powder 8 is formed, the forming cylinder descends and makes the upper end surface of the cylinder body 3 of the forming cylinder flush with the piston, and the second metal powder 8 is discharged;

[0040] Step 8: The second metal powder 8 is discharged;

[0041] Step 9: The forming cylinder is first raised, and then the piston in the forming cylinder is raised, and the forming bottom plate 14 on the forming cylinder piston and the formed part thereon are extended into the forming box, and the formed part can be taken out.

[0042] If there is a third or fourth material, after the second material is discharged, the third or fourth metal powder can be formed according to the method of step 4 to step 6 until all types of metal powders are formed, and finally a molded part composed of multiple materials is formed.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A powder bed laser melting forming technology equipment for forming a variety of metals, characterized by: The invention comprises a forming chamber, a forming cylinder, a powder discharge cylinder (1), a forming cylinder driving device and a powder container (2); the forming cylinder is arranged below the forming chamber and can be lifted and lowered longitudinally; the forming cylinder driving device drives the cylinder body (3) of the forming cylinder to lift and lower; the upper end of the cylinder body of the forming cylinder can be in close contact with the lower surface of the bottom plate (4) of the forming chamber; the piston (5) in the forming cylinder can be inserted into the powder inlet on the bottom plate of the forming chamber in a dynamic and sealed manner; the upper end of the powder discharge cylinder is sealed and fixedly positioned with the lower side surface of the bottom plate of the forming chamber; at least one powder discharge channel (6) is provided on the side wall of the powder discharge cylinder and penetrates in the radial direction thereof; the powder discharge cylinder sleeve is arranged on the outer side of the forming cylinder insert, and the outer wall of the forming cylinder is in contact with the outer side of the forming cylinder. The inner wall of the powder discharge cylinder is in close contact, and the cylinder body of the forming cylinder descends so that the powder inside can be connected to the inlet of the powder discharge channel, and the outlet of the powder discharge channel is connected to the inlet of the powder container. The outlet of the powder discharge channel is also installed with a powder outlet pipe (10), and the outlet of the powder outlet pipe is directly opposite to the powder container. A powder discharge valve (11) is installed on the powder outlet pipe, and the powder discharge valve can open and close the powder outlet pipe. At least one powder discharge cross channel (12) extending radially thereof is provided on the upper end surface of the cylinder body of the forming cylinder, one end of the powder discharge cross channel is connected to the inside of the forming cylinder, and the other end of the powder discharge cross channel can be connected one-to-one with the inlet of the powder discharge channel on the side wall of the powder discharge cylinder as the forming cylinder descends.

2. The powder bed laser melting forming technology equipment for forming various metals as claimed in claim 1, characterized in that: At least one radial groove (9) extending in the longitudinal direction is provided on the inner side wall of the powder discharge cylinder, the upper end of the radial groove passes through the upper end surface of the powder discharge cylinder, and the lower end of the radial groove is connected to the inlet of the powder discharge channel.

3. The powder bed laser melting forming technology equipment for forming various metals as claimed in claim 2, characterized in that: The radial grooves on the inner wall of the powder discharge cylinder are evenly spaced along the circumferential direction of the powder discharge cylinder, and the powder discharge channels are also evenly spaced along the circumferential direction of the powder discharge cylinder. The radial grooves are connected to the powder discharge channels in a one-to-one correspondence, and the radial grooves form the inlet of the powder discharge channel.

4. The powder bed laser melting forming technology equipment for forming various metals according to claim 1, characterized in that: The powder discharge channel is an inclined structure in which the height of one end facing the inner side of the powder discharge cylinder is higher than the height of the other end facing the outer side of the powder discharge cylinder.

5. The powder bed laser melting forming technology equipment for forming various metals according to claim 1, characterized in that: An outer cylinder (13) is also provided, the upper end of which is fixedly sleeved on the outer side of the lower end of the powder discharge cylinder, and a receiving space for the raising and lowering of the forming cylinder is formed inside the outer cylinder.

6. The powder bed laser melting forming technology equipment for forming various metals as claimed in claim 5, characterized in that: The inner wall of the outer cylinder is sealingly connected to the outer wall of the powder discharge cylinder, the outer wall of the forming cylinder is in dynamic sealing contact with the inner wall of the powder discharge cylinder, a sealed space is formed between the outer cylinder, the powder discharge cylinder and the forming cylinder, and an oil path or an air path connected to the sealed space is also provided on the side wall of the outer cylinder.

7. The powder bed laser melting forming technology equipment for forming various metals as claimed in claim 1, characterized in that: A forming bottom plate (14) is also provided on the upper surface of the piston of the forming cylinder. The forming bottom plate can be flush with the bottom surface of the forming chamber, or can be higher than the bottom surface of the forming chamber by a set height.

8. The powder bed laser melting forming technology equipment for forming various metals as claimed in claim 1, characterized in that: A frame, a laser melting system, a powder supply device and a powder scraping device are also provided. The forming chamber is fixedly installed on the frame. The powder supply device can supply forming powder to the forming chamber. The powder scraping device can scrape the powder on the bottom plate of the forming chamber into the forming cylinder to form a powder layer of specified thickness. The laser melting system is installed above the forming chamber. The laser melting system can perform laser melting and forming on the powder layer in the forming cylinder.

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