JP7563192B2 - Blasting Equipment - Google Patents

Description

This disclosure relates to a blast processing device.

Patent document 1 discloses a device that blows a powder-containing airflow onto a three-dimensional object created by additive manufacturing technology. This device uses the powder used to create the three-dimensional object as the powder to be blown.

JP 2016-153212 A

In the aircraft or medical fields, parts may be manufactured by additive manufacturing technology. In these fields, it is necessary to avoid contamination of parts. According to the device described in Patent Document 1, when a three-dimensional object is formed from metal powder, the metal powder is sprayed onto the three-dimensional object. However, metal powder has physical properties that make it highly explosive due to dust. Furthermore, in advanced technology products such as the automotive, aerospace, and medical fields, there is an increasing demand for foreign matter management, and there is a need for processing to reduce contamination of parts by foreign matter. For this reason, the present disclosure provides a technology that can improve the safety of operations while reducing contamination of the surface of an additively manufactured object made from a metal powder by foreign materials when blasting the additively manufactured object.

A blasting device according to one aspect of the present disclosure includes a processing chamber, a tank, an inert gas source, and a nozzle. The processing chamber contains an additive manufacturing object made of metal powder as a raw material. The tank stores a propellant having at least one metal element contained in the metal powder. The nozzle is disposed in the processing chamber and blasts the additive manufacturing object in the processing chamber using the propellant stored in the tank and the inert gas supplied from the gas source.

In this blasting device, the layered object is blasted using abrasives that contain at least one metal element contained in the metal powder that is the raw material of the layered object. This makes it possible to blast the surface of the layered object while reducing contamination of the surface of the layered object with different materials. The abrasives are then sprayed onto the layered object using an inert gas. This makes it possible to prevent dust explosions. This blasting device therefore improves operational safety while reducing contamination of the surface of the layered object with different materials.

In one embodiment, the blast processing device may include a sensor and a gas supply unit. The sensor detects the oxygen concentration in the treatment chamber. The gas supply unit supplies an inert gas to the treatment chamber based on the detection result of the sensor. In this case, the blast processing device can adjust the oxygen concentration in the treatment chamber based on the sensor detection result, thereby further improving the safety of operations.

In one embodiment, the gas supply unit may supply an inert gas to the processing chamber based on the detection result of the sensor so that the oxygen concentration in the processing chamber is 10% or less. By adjusting the atmosphere in the processing chamber so that the oxygen concentration is 10% or less, the safety of the operation can be further improved.

In one embodiment, the blast processing device may include a first classification unit that classifies the unmelted metal powder used in forming the additive manufacturing object and supplies it to the tank. In this case, the blast processing device can suppress a decrease in the accuracy of the blast processing when reusing the metal powder used in forming the additive manufacturing object. In addition, since there is no need to prepare abrasives of the same material as the molded object, costs can be reduced.

In one embodiment, the blast processing device may include a second classification section that classifies the abrasives used in the blast processing in the processing chamber and supplies the abrasives to the tank. In this case, the blast processing device can prevent a decrease in the accuracy of the blast processing when reusing the abrasives used in the blast processing of the layered object.

In one embodiment, a gas circulation system may be provided to circulate the inert gas recovered from the processing chamber to the nozzle. In this case, the blast processing device can efficiently reuse the inert gas.

According to the present disclosure, when blasting an additive manufacturing object made from metal powder as a raw material, it is possible to improve operational safety while reducing contamination of the surface of the additive manufacturing object with different materials.

FIG. 1 is a schematic diagram of a blast processing device according to an embodiment.

Various embodiments will be described in detail below with reference to the drawings. The same or equivalent parts in each drawing are given the same reference numerals.

[Overview of the object to be blasted]
FIG. 1 is a schematic diagram of a blast processing device according to an embodiment. The blast processing device 1 shown in FIG. 1 is a device for blasting a layered object L. The layered object L is an object manufactured by additive manufacturing technology, and is composed of a plurality of layers stacked up. An example of the additive manufacturing technology is a powder bed method. The powder bed method is a method of forming a shape by spreading metal powder in layers and irradiating it with a laser or the like to melt and solidify it. The additive manufacturing technology for manufacturing the layered object L is not limited to the powder bed method, and may be a binder jet method or a fused deposition model method. Examples of metals used in manufacturing the layered object L include maraging steel, stainless steel, aluminum, titanium, and nickel/cobalt alloys.

[Blast Processing Equipment Overview]
1, the blast processing device 1 includes a cabinet body 10. The cabinet body 10 defines a processing chamber S therein. A nozzle 11 and a layered object L are housed in the processing chamber S, and the nozzle 11 blasts the layered object L. The nozzle 11 is connected to a tank 12 and a gas receiver tank 13 (an example of a gas circulation system).

The tank 12 is a container for storing the abrasive material. The tank 12 stores the abrasive material having at least one metal element contained in the metal powder, which is the raw material of the layered object L. In this case, the main material of the abrasive material may be the same as the main component of the metal powder, which is the raw material of the layered object L, and the other components may be materials that do not affect the performance or reliability of the layered object L. The abrasive material may also be the same metal powder as the raw material of the layered object L. The receiver tank 13 is a container for storing an inert gas. A gas cylinder 24, which is a gas source of the inert gas, is connected to the receiver tank 13. The inert gas is a non-oxygen gas, and examples of the inert gas include argon gas, nitrogen gas, and helium gas. The nozzle 11 sprays the abrasive material stored in the tank 12 to the layered object L together with the inert gas supplied from the gas cylinder 24 via the receiver tank 13. The spray method of the nozzle 11 may be either a suction type or a direct pressure type. Additionally, an inert gas generator 25 may be connected to the receiver tank 13 as a source of inert gas.

The receiver tank 13 is also connected to the processing chamber S via piping 14, and can directly supply inert gas to the processing chamber S. By directly supplying inert gas to the processing chamber S, the atmosphere during blast processing can be efficiently controlled. The atmosphere in the processing chamber S may be adjusted based on the detection results of an oxygen sensor 15 that detects the oxygen concentration in the processing chamber S.

The blasting device 1 includes a control unit 16 (an example of a gas supply unit) that controls all of the components, and the atmosphere in the processing chamber S may be adjusted by the control unit 16. The control unit 16 may be configured as a PLC (Programmable Logic Controller) as an example. The control unit 16 may include a computer system including a processor such as a CPU (Central Processing Unit), a memory such as a RAM (Random Access Memory) and a ROM (Read Only Memory), an input/output device such as a touch panel, a mouse, a keyboard, and a display, and a communication device such as a network card. The control unit 16 controls the amount of inert gas supplied from the receiver tank 13 to the processing chamber S based on the detection result of the oxygen sensor 15. As an example, the control unit 16 may supply the inert gas to the processing chamber S so that the oxygen concentration in the processing chamber S is 10% or less. In this case, the frequency of dust explosions can be reduced. As an example, the control unit 16 may supply the inert gas to the processing chamber S so that the oxygen concentration in the processing chamber S is 5% or less. In this case, the frequency of dust explosions can be further reduced.

[Injection material circulation system]
A first classifier 17 is connected to the tank 12. The first classifier 17 is a device that adjusts the particle size of the powder, and is, for example, a classification device. Unmelted metal powder collected during the production of the layered object L is supplied to the first classifier 17. The first classifier 17 sifts the unmelted metal powder and supplies only metal powder having a particle size suitable for blast processing to the tank 12. In this way, the metal powder that was used once in the production process is reused.

The processing chamber S is provided with a floor 10a that supports the layered object L. The floor 10a is made of a mesh-like member through which the abrasive material and the inert gas can flow. The abrasive material sprayed onto the layered object L passes through the floor 10a and falls to the bottom of the processing chamber S. A transport unit 18 is disposed at the bottom of the processing chamber S. The transport unit 18 collects the fallen abrasive material and transports it to the second classification unit 19. The second classification unit 19 is a device that adjusts the particle size of the powder, and is, for example, a classification device. The second classification unit 19 returns only the abrasive material having a particle size suitable for blast processing to the tank 12. In this way, the abrasive material used once for blast processing is reused.

The gas exhausted from the processing chamber S is sent to the separator 20. The separator 20 separates the gas and the abrasives by centrifugal force. The abrasives separated by the separator 20 are supplied to the second classification section 19 described above. The second classification section 19 returns only the abrasives having a particle size suitable for blasting to the tank 12. In this way, the abrasives used once in blasting are reused. When the gas separated by the separator 20 is exhausted, it is exhausted to the outside via the dust collector 21.

[Inert gas circulation system]
The inert gas separated by the separator 20 is returned to the receiver tank 13 via a compressor 22 (an example of a gas circulation system). This allows the inert gas once used in the blasting process to be reused. The concentration of the inert gas returned to the receiver tank 13 may be adjusted. In this case, the inert gas is passed through an oxygen filter or the like before being returned to the receiver tank 13. An exhaust pump 23 is connected to the receiver tank 13, and the pressure inside the tank is adjusted. This makes it easy to take gas in and out of the receiver tank 13.

[Summary of the embodiment]
In the blasting processing device 1, the layered object L is blasted using abrasives having at least one metal element contained in the metal powder that is the raw material of the layered object L. The surface of the layered object L can be blasted while reducing contamination of the surface of the layered object L with different materials. The abrasives are sprayed onto the layered object L by an inert gas. This makes it possible to prevent dust explosions. Therefore, the blasting processing device 1 can improve operational safety while reducing contamination of the surface of the layered object L with different materials.

The blast processing device 1 can adjust the oxygen concentration in the processing chamber S based on the detection results of the oxygen sensor 15, thereby further improving operational safety. The blast processing device 1 can adjust the oxygen concentration in the processing chamber S to 10% or less, thereby further improving operational safety. In addition, by controlling the oxygen concentration in the processing chamber S to 10% or less, surface oxidation of the layered object L can also be suppressed.

When reusing the metal powder used in forming the layered object L, the blasting device 1 sifts out the unmelted metal powder using the first classification unit 17, and reuses only the metal powder having a particle size suitable for the blasting process. This makes it possible to prevent a decrease in the accuracy of the blasting process. When reusing the abrasives used in the blasting process of the layered object L, the blasting device 1 collects the abrasives that have fallen to the bottom of the processing chamber S, and reuses only the abrasives having a particle size suitable for the blasting process using the second classification unit 19. This makes it possible to prevent a decrease in the accuracy of the blasting process. Also, the blasting device 1 can reuse the inert gas used in the blasting process of the layered object L.

Although various exemplary embodiments have been described above, various omissions, substitutions, and modifications may be made without being limited to the above embodiments.

1...blast processing device, S...processing chamber, 11...nozzle, 12...tank, 13...receiver tank (an example of a gas circulation system), 16...control unit (an example of a gas supply unit), 20...separator, 22...compressor (an example of a gas circulation system), 24...gas cylinder, 25...inert gas generator.

Claims (4)

a processing chamber for accommodating an additive manufacturing object made of metal powder;
a tank for storing an abrasive material having at least one of the metal elements contained in the metal powder;
a source of inert gas;
a nozzle that is disposed in the processing chamber and blasts the layered object in the processing chamber using the abrasive stored in the tank and the inert gas supplied from the gas source;
A first classifier that classifies the unmelted metal powder collected during the manufacturing of the layered object and supplies the powder to the tank;
A second classifying unit that classifies the abrasives used in the blasting process in the treatment chamber and supplies the abrasives to the tank;
A blast processing device comprising: a sensor for detecting an oxygen concentration in the processing chamber;
a gas supply unit that supplies the inert gas to the processing chamber based on a detection result of the sensor;
The blasting apparatus according to claim 1 . The blasting device according to claim 2, wherein the gas supply unit supplies the inert gas to the processing chamber so that the oxygen concentration in the processing chamber is 10% or less based on the detection result of the sensor. The blast processing device according to any one of claims 1 to 3, further comprising a gas circulation system for circulating the inert gas recovered from the processing chamber to the nozzle.

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