Powder material supply device and powder material supply method for laser processing apparatus

Abstract

To continuously supply powder material to an adjustment tank where a moving-up / down shaft for adjusting a discharge amount of the powder material is arranged, and als to discharge the powder material continuously associatively with the moving-up / down shaft.SOLUTION: A powder material supply device comprises: an adjustment tank 12 where a moving-up / down shaft 13 for adjusting the discharge amount of the powder material is arranged; a discharge amount measurement sensor 16 which measures the powder material discharged from the adjustment tank 12 to a following process in a discharge path F12 thereof; and a discharge amount control part 18B which feeds a measurement result of the discharge amount measurement sensor 16 back to control the moving-up / down shaft 13. The powder material supply device further comprises: a storage tank 11 for the powder material supplied to the adjustment tank 12; a supply amount measurement sensor 14 which measures the amount of powder in the adjustment tank; and a supply amount control part 18A which controls the amount of powder supplied from the storage tank 11 to the adjustment tank 12 according to the measurement result of the supply amount measurement sensor 14.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a powder material supply apparatus and a powder material supply method for a laser processing apparatus that performs laser processing while supplying a powder material to an irradiation portion of a laser beam.

Background Art

[0002] Laser processing apparatuses that emit laser light from an optical fiber have been put into practical use in applications such as laser welding and laser soldering. In overlay welding and thermal spraying, a coating is formed for the purpose of improving the heat resistance, corrosion resistance and wear resistance of the material itself. For example, in a laser powder cladding apparatus, a molten material (powder material) as a raw material is irradiated with laser light, heated and melted, and formed into a coating to coat the surface of a base material. In such a laser powder cladding apparatus, the surface of the base material is irradiated with laser light, and a molten material (such as a powder material) is supplied from a supply nozzle disposed on the outer circumference on the optical axis of the irradiated laser light, thereby melting the molten material and performing cladding processing. In the pre-process of the laser processing portion irradiated with laser, a supply apparatus for the molten material that is the raw material is disposed, and is provided with a component that ejects the material from an ejection nozzle.

[0003] FIG. 5 and FIG. 6 show a conventional powder material supply apparatus 101 for a laser processing apparatus according to the applicant of the present application. The apparatus includes a powder tank provided with a vertically movable shaft 102 that adjusts the supply amount of the powder material, and ejects the powder material using gas supplied from a carrier gas supply port 103. The vertically movable shaft 102 is rotated and moved vertically by a motor disposed above.

[0004] Here, the following patent documents are disclosed regarding laser processing apparatuses. Patent Document 1 discloses an apparatus (100) comprising: a laser apparatus (110) for material processing using a laser beam (112), configured to direct the laser beam (112) onto a processing area of ​​a workpiece (10); at least one feeder (130) for a feeder material, configured to supply the feeder material to the processing area; and an interferometer (140) configured to measure the distance to the surface of the workpiece (10) using an optical measuring beam (142). Patent Document 2, in its abstract, states, "(Problem) To provide a method for manufacturing a three-dimensional molded object that can level material powder in a more suitable manner." It then discloses, "(Solution) A method for manufacturing a three-dimensional molded object, comprising the steps of (i) irradiating a light beam onto a predetermined location in a powder layer to sinter or melt and solidify the powder at the predetermined location to form a solidified layer, and (ii) forming a new powder layer on the obtained solidified layer, and irradiating a light beam onto a predetermined location in the new powder layer to form a further solidified layer, wherein a powder layer is formed by leveling the material powder, and the amount of material powder being leveled is detected." Patent Document 3 discloses a laser processing apparatus in which "a condenser lens (3) is arranged so as to penetrate a supply nozzle (4), and a plurality of optical fibers (1) and a plurality of collimator lenses (2) are arranged parallel to each other around the supply nozzle (4), so that the optical fibers (1) and collimator lenses (2) remain in parallel arrangement, and the molten material (9) supplied from the supply nozzle (4) is irradiated with a laser along the axis (O) from the nozzle tip opening (4a) to the welding site (base material) (BM)." [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-6719 [Patent Document 2] Japanese Patent Publication No. 2002-97532 [Patent Document 3] Patent No. 6757877 [Overview of the project] [Problems that the invention aims to solve]

[0006] In the conventional device of the above-mentioned applicant, when material powder is introduced into the powder tank 105, the material powder falls along the inclined section of the powder tank and is discharged after the opening and closing amount is adjusted by the vertical movement shaft 102. However, when the amount of powder decreases, it becomes difficult to dispense the powder material, and depending on the inclination angle, the powder material that does not fall can become clogged. Furthermore, there was a problem in that it was difficult to coordinate the operation with the vertical movement shaft 102. Furthermore, while the discharge side of the conventional device described above detects the fall with a measuring unit, it had problems such as the inability to continuously supply and discharge powder material, and the difficulty in coordinating operation with the vertical movement shaft 102. In addition, laser processing equipment handles powders with particle sizes such as 30μm to 100μm or 50 to 150μm, but such powders are fine particles that float in the air, making them difficult to control, and it is also difficult to coordinate operation (synchronous drive) with the laser processing equipment itself. Therefore, the object of the present invention is to provide a powder material supply device for a laser processing apparatus that continuously supplies powder material to an adjustment tank where a vertically moving shaft for adjusting the amount of powder material discharged is located, thereby keeping the amount of powder in the adjustment tank constant, and performing continuous and stable discharge (supply to subsequent processes) of powder material while coordinating with the vertically moving shaft. [Means for solving the problem]

[0007] The present invention relates to a powder material supply device for a laser processing apparatus that performs laser processing while supplying powder material to a laser beam irradiation section, characterized in that it comprises a secondary adjustment tank on which a vertically moving shaft for adjusting the amount of powder material discharged is arranged, an discharge amount measurement sensor for measuring the amount of powder material discharged from the secondary adjustment tank to a subsequent process along its discharge path, and a discharge amount control unit that controls the vertically moving shaft by receiving feedback of the measurement results from the discharge amount measurement sensor. According to the present invention, the discharge measurement sensor measures the amount of powder material discharged, and the measurement result obtained is fed back to the discharge control unit, which controls the continuous discharge of the powder material. In other words, the discharge amount is adjusted by the vertical movement of the vertical movement shaft in the laser processing unit, so that the powder material can be discharged without interruption.

[0008] The present invention is characterized in that the emission measurement sensor includes an irradiation device that irradiates the powder material passing through the emission path with light or ultrasound, and a detector that detects the amount of attenuation of the light or ultrasound irradiated from the irradiation device on the opposite side of the emission path from the irradiation device. According to the present invention, by employing a method of measuring the discharge amount by irradiating the discharged powder material with light or ultrasound, mechanisms and processes for retaining the discharged powder material, such as tanks necessary for other discharge amount measurements by weight or volume, become unnecessary, thus enabling smoother discharge and supply of powder material to subsequent processes.

[0009] The present invention comprises a primary storage tank for storing powder material supplied to the secondary adjustment tank, a powder quantity measuring sensor for measuring the amount of powder in the secondary adjustment tank, and a supply quantity control unit that controls the amount of powder supplied from the primary storage tank to the secondary adjustment tank based on the measurement results of the powder quantity measuring sensor, and is characterized by adjusting the supply amount from the storage tank in order to maintain the amount of powder in the secondary adjustment tank within a predetermined range. According to the present invention, a powder quantity measuring sensor measures the amount of powder material in the secondary preparation tank and controls the amount of powder material supplied from the primary storage tank, thereby preventing the secondary preparation tank from becoming empty and maintaining the amount of powder in the preparation tank within a predetermined range, thereby achieving stable and continuous discharge of powder material.

[0010] The present invention is characterized in that powder material is supplied from the primary storage tank until the amount of powder in the secondary adjustment tank reaches a predetermined range, and the vertical movement shaft is positioned so that the powder material in the secondary adjustment tank is not discharged. According to the present invention, overloading is prevented by performing the discharge operation when the secondary preparation tank is empty, and the discharge operation is not performed until the amount of powder in the preparation tank reaches a predetermined range, thereby minimizing the yield before stable discharge of the powder material is achieved.

[0011] The present invention relates to a method for supplying powder material by a powder material supply device in a laser processing apparatus that performs laser processing while supplying powder material to a laser beam irradiation section, characterized in that, in a secondary adjustment tank where a vertically moving shaft for adjusting the amount of powder material discharged is arranged, the vertically moving shaft is controlled by feeding back the measurement results from an discharge measurement sensor that measures the amount of powder material discharged from the adjustment tank to a subsequent process along its discharge path, and the amount of powder supplied from the primary storage tank to the secondary adjustment tank is controlled by a primary storage tank for the powder material supplied to the secondary adjustment tank and a powder amount measurement sensor that measures the amount of powder in the secondary adjustment tank, thereby maintaining the amount of powder in the secondary adjustment tank within a predetermined range, and minimizing changes in the amount of powder discharged due to increases or decreases in the amount of powder in the secondary adjustment tank, as well as the movement of the vertically moving shaft during the discharge of the powder material. According to the present invention, by using an discharge volume measurement sensor and a powder volume measurement sensor, it is possible to minimize changes in the discharge volume caused by controlling the vertical movement of the shaft during the discharge of powder material (during supply to the next process), thereby achieving stable and continuous discharge of powder material. Furthermore, the laser processing apparatus is equipped with a supply amount control unit that controls the amount of powder material supplied, and the supply amount control unit has the same inverted cone shape as the secondary adjustment tank in which an up-and-down moving shaft for adjusting the amount of powder material discharged is arranged, and it is possible to drive it synchronously with the secondary adjustment tank and / or to perform feedback control, and the supply amount control unit is capable of feedback control with respect to the secondary adjustment tank and / or is capable of driving it synchronously with the up-and-down movement of the up-and-down moving shaft. [Effects of the Invention]

[0012] According to the present invention, a powder quantity measuring sensor measures the amount of powder material in the secondary preparation tank and controls the supply amount from the primary storage tank, thereby continuously supplying the powder material to the laser processing unit and preventing the secondary preparation tank from becoming empty. Furthermore, in conventional devices, the amount of powder material discharged changes depending on the increase or decrease in the amount of powder in the secondary preparation tank, requiring delicate control of the vertical movement shaft. However, according to the present invention, a stable and continuous supply of powder material becomes possible. [Brief explanation of the drawing]

[0013] [Figure 1] This is an internal structure diagram showing the powder material supply device of the laser processing apparatus of the present invention. [Figure 2] This is an internal structure diagram showing the powder material supply device of the laser processing apparatus of the present invention. [Figure 3] This is an internal structure diagram showing the powder material supply device of the laser processing apparatus of the present invention. [Figure 4] This is a process flow illustrating the control in the control unit of the powder material supply device of the laser processing apparatus of the present invention. [Figure 5]It is an internal structural diagram of a powder material feeder of a conventional laser processing apparatus. [Figure 6] It is an internal structure of a powder material feeder of a conventional laser processing apparatus. [Figure 7] It is a diagram illustrating an application example of the powder material feeder of the laser processing apparatus according to the present invention. [Figure 8] It is a diagram illustrating an application example of the powder material feeder of the laser processing apparatus according to the present invention. [Figure 9(a)] It is a diagram illustrating an application example of the powder material feeder of the laser processing apparatus according to the present invention. [Figure 9(b)] It is a diagram illustrating an application example of the powder material feeder of the laser processing apparatus according to the present invention. MODE FOR CARRYING OUT THE INVENTION

[0014] The present embodiment is, as shown in Figs. 1 to 3, a powder material feeder 1 for a laser processing apparatus that performs laser processing while supplying powder material to a laser beam irradiation section. An adjustment tank (secondary tank) 12 in which a vertically moving shaft 13 for adjusting the discharge amount of powder material is disposed, and a storage tank (primary tank) 11 are disposed above the secondary adjustment tank, and a powder amount measurement sensor 14 for measuring the amount of powder material in the secondary adjustment tank is disposed in the adjustment tank 12. The apparatus further comprises the adjustment tank 12 in which the vertically moving shaft 13 for adjusting the discharge amount of powder material is disposed, and a discharge amount measurement sensor 16 that measures the powder material discharged from the adjustment tank 12 to a subsequent process in the discharge path F12. A control unit 18 includes a discharge amount control unit 18B that feeds back the measurement result of the discharge amount measurement sensor 16 to control the vertically moving shaft 13, and a supply amount control unit 18A that controls the amount of powder supplied from the primary storage tank to the secondary adjustment tank based on the measurement result of the powder amount measurement sensor 14 that measures the amount of powder in the secondary adjustment tank (Fig. 2). As for the powder material, powder materials such as metals are used as the molten material, but non-metallic materials such as ceramics can also be used and can be selected as appropriate. For example, any metallic material can be used, including stainless steel, nickel-based alloys (Inconel), tungsten carbide composites, copper alloys, brass, cobalt-chromium-molybdenum alloys, Stellite, and tool steel. Examples of powder material particle sizes include 30 μm to 100 μm and 50 μm to 150 μm, but are not limited to these. Furthermore, in electrode manufacturing equipment, for doping electrode materials, it is sometimes required to continuously supply minute amounts of lithium powder (powder), such as tens of milligrams / minute to a few grams / minute, with an accuracy of ±10% or less. In addition, powders for three-dimensional molding are widely used as raw materials for molded and shaped plastic products. Powders for three-dimensional molding are handled in various forms, such as pellets with a size in the millimeter range and powders with a size in the micrometer range. In the laser processing apparatus (main unit) 21, the powder material is ejected from the blowing nozzle 23a of the supply unit 23 at the tip of the inverted cone-shaped tank (cavity 5), and is supplied together with the carrier gas 24. An inert gas such as helium, argon, or nitrogen is used as the carrier gas 24, and furthermore, a shielding gas consisting of an inert gas is supplied to the outside of the carrier gas containing the powder material to suppress oxidation of the material during laser stacking. The flow rate control unit (supply amount control unit) 26 on the main body side 21 is equipped with a control valve and sprays the powder material 21 from the powder material supply device 1 onto the processing plate (workpiece) 27 under computer control. The powder material supplied from the main body side 21 is sprayed from the blowing nozzle 23a of the inverted cone-shaped supply unit 23, and has an inverted triangular configuration similar to the configuration of the adjustment tank 12 where the vertical movement shaft 13 for adjusting the amount of powder material discharged is located, making it easy to control the supply of powder material by computer. In other words, according to this embodiment, as shown in Figure 7, the material is injected from the blowing nozzle 23a of the inverted cone-shaped supply unit 23, and the material supply unit is capable of vertical movement, enabling synchronous drive with the adjustment tank (secondary side) 12 where the vertical movement shaft 13 is located, as well as feedback control. The flow rate control unit (supply amount control unit) 26 is structured to control the nozzle injection of powder (powder) taking into account the vertical movement of the vertical movement shaft 13. It also enables synchronous drive with the storage tank 11, and feedback control is possible. It is also possible to arrange a vertical movement shaft in the material supply unit 23 on the main body side 21, similar to the adjustment tank 21 on the secondary side, to achieve complete synchronous drive of these vertical movements. Furthermore, as shown in Figure 8, the vertical movement shaft 13 is configured to be driven synchronously with the adjustment tank (secondary side) 12, and feedback control is also possible. The powder material supply unit 23 on the main body side 21 is capable of vertical movement, and by arranging the vertical movement shaft, it is possible to achieve complete synchronous drive of these vertical movements. Synchronized drive with the melting function 24 and the surface temperature measurement sensor 31, which will be described later, is also possible. Furthermore, as shown in Figures 9(a) and 9(b), in addition to the above control, the sensor (surface temperature measuring sensor) 31 in the laser head can measure the surface temperature of the workpiece 27 in conjunction with the control of the laser transmitter 32, while supplying the material powder to the workpiece. This material powder supply while measuring the surface temperature of the workpiece 27 is then fed back to the powder material supply device 1.

[0015] The powder material supply device 1 of this apparatus uses a method of dropping powder material from the upper primary storage tank 11 to the secondary adjustment tank 12 via a supply path F11, and then discharging it from the secondary adjustment tank 12 to the next process via a discharge path. Powder material is supplied from the primary storage tank 11 until the amount of powder in the secondary adjustment tank reaches a predetermined range, and the vertical movement shaft is positioned so that the powder material in the adjustment tank is not discharged. Therefore, a simple structure using gravity-feed supply and discharge enables continuous supply and discharge of powder material. Inside the secondary adjustment tank 12, an inverted cone-shaped inclined section is formed, and the vertical movement shaft 13 moves up and down relative to the tip opening to adjust the amount of opening and closing of the tip opening. Furthermore, the system includes a supply amount control unit 18A that controls the amount of powder supplied from the primary storage tank 11 to the secondary adjustment tank 12 based on the measurement results of a powder amount measuring sensor 14 that measures the amount of powder in the secondary adjustment tank 12. The supply amount from the primary storage tank 12 is adjusted to maintain the amount of powder in the secondary adjustment tank within a predetermined range (Figure 2).

[0016] The vertical shaft 13 of the powder material supply device (feeder) 1 only moves up and down and does not rotate. However, it works in conjunction with the discharge control unit 18B, which is controlled by the discharge measurement sensor 16, to continuously discharge an appropriate amount of powder material (supply it to the next process). In other words, the discharge control unit 18B adjusts the opening and closing amount by speeding up or slowing the vertical movement of the vertical shaft, thereby discharging an appropriate amount of powder.

[0017] (Control method) Next, the control unit 18 performs the following control. As shown in the flow diagram in Figure 4, the device (feeder) 1 is started after setting the target amount of powder material and the opening amount (initial position) of the vertical movement shaft 13 at the start of the device (feeder) 1. When this device (feeder) 1 is started, a solenoid that uses electromagnetic force to move the movable iron core in one direction is turned ON, thereby initiating laser irradiation and the discharge (injection) of the powder material. Finally, the injection (discharge) of the powder material is stopped by turning the solenoid OFF. During these processes, the discharge measurement sensor 16 located in the discharge path F12 provides feedback on the measurement results, and the discharge control unit 18B controls the vertical movement shaft 13 by controlling the vertical movement shaft 13.

[0018] Furthermore, a powder quantity measuring sensor 14 is located in the adjustment tank 12. When it detects that the amount of powder in the tank is less than a predetermined range, the storage tank 11 located above the adjustment tank 12 is activated. The powder quantity measuring sensor 14 can also detect when the powder in the secondary adjustment tank 12 is empty. If the amount of powder in the tank is empty or less than a predetermined range, it does not perform a discharge operation. When the amount of powder in the tank reaches a predetermined range, it starts the discharge operation.

[0019] The emission measurement sensor 16 includes an irradiation device that irradiates the powder material passing through the emission path F12 with light or ultrasound, and on the opposite side of the emission path from the irradiation device, there is a detector that detects the amount of attenuation of the light or ultrasound irradiated from the irradiation device, and the measured information is fed back to the emission control unit 18B.

[0020] In this embodiment, the powder quantity measuring sensor 14 is positioned on the upper surface of the secondary preparation tank 12 and consists of an irradiation unit that irradiates light or ultrasonic waves onto the lower side of the tank and a detector provided on the lower side of the tank opposite the irradiation unit. The configuration of the powder quantity measuring sensor 14 and the supply quantity control unit 18A is not limited and can be appropriately selected, such as determining the amount of powder in the tank by the attenuation of the irradiated light or ultrasonic waves, measuring the amount of powder by the weight of the tank, measuring the amount of powder by volume, or measuring by image data.

[0021] (Comparison with conventional devices) Compared to the conventional apparatus shown in Figures 5 and 6, the present invention features a primary storage tank 11 positioned above the secondary adjustment tank 12, a simple drop-type structure, and the addition of a powder quantity measuring sensor 14 and a supply quantity control unit 18A located in the adjustment tank 12. Compared to the conventional apparatus, which required subtle control of the vertical movement shaft 13 in response to changes in discharge volume caused by increases or decreases in the powder material in the secondary adjustment tank, the present invention makes it possible to maintain the amount of powder material in the secondary adjustment tank within a predetermined range, enabling easy, stable, and continuous discharge of powder material. As described above, this embodiment can be widely applied to powder material supply devices for laser processing equipment. [Explanation of Symbols]

[0022] 1 Powder material supply device (feeder), 11. Primary storage tank (primary tank), 12. Secondary side adjustment tank (secondary side tank), 13 Up-and-down shaft, 14. Powder quantity measurement sensor, 15. Carry gas supply port, 16 Emission measurement sensors, 18 Control unit, 18A Supply amount control unit, 18B Emission control unit, 19. Solenoid control unit, F11 Powder material supply route, F12 Discharge route for powdered material, 21 Laser processing device (main unit), 23 Powder material supply unit, 23a Tip of spray nozzle, 26 Supply amount control unit

Claims

1. A powder material supply device for a laser processing apparatus that performs laser processing while supplying powder material to the laser beam irradiation area, The system comprises a secondary adjustment tank on which a vertically moving shaft for adjusting the amount of powder material discharged is arranged, an discharge measurement sensor for measuring the amount of powder material discharged from the secondary adjustment tank to the subsequent process along its discharge path, an discharge control unit for controlling the vertically moving shaft based on the measurement results of the discharge measurement sensor, and a primary powder material supply unit for supplying powder material to the secondary adjustment tank. The powder material supply device for a laser processing apparatus is characterized in that the primary side powder material supply unit has a powder passage with the same inverted cone shape as the secondary side adjustment tank, and controls the amount of powder material supplied from the primary side powder material supply unit to the secondary side adjustment tank, thereby suppressing fluctuations in the amount of powder in the secondary side adjustment tank.

2. The powder material supply device for a laser processing apparatus according to claim 1, characterized in that the discharge measurement sensor comprises an irradiation device that irradiates light or ultrasonic waves onto the powder material passing through the discharge path, and a detector positioned opposite the irradiation device across the discharge path and detecting the amount of attenuation of the light or ultrasonic waves.

3. The powder material supply device for a laser processing apparatus according to claim 1 or 2, characterized in that powder material is supplied from the primary storage tank until the amount of powder in the secondary adjustment tank reaches a predetermined range, and the vertical movement shaft is positioned so that the powder material in the secondary adjustment tank is not discharged.

4. A method for supplying powder material in a laser processing apparatus that performs laser processing while supplying powder material to the laser beam irradiation area, A step of measuring the amount of powder material discharged from a secondary adjustment tank, which is equipped with a vertically moving shaft for adjusting the amount of powder material discharged to a subsequent process, using an discharge measurement sensor in the discharge path, and controlling the vertically moving shaft based on the measurement result of the discharge measurement sensor, The process of supplying powder material from the primary side powder material supply unit to the secondary side adjustment tank, A method for supplying powder material for a laser processing apparatus, characterized in that, as the primary side powder material supply unit, a supply unit having a powder passage with the same inverted cone shape as the secondary side adjustment tank is used, and the amount of powder material supplied from the primary side powder material supply unit to the secondary side adjustment tank is controlled, thereby supplying powder material while suppressing fluctuations in the amount of powder in the secondary side adjustment tank.

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