3D additive manufacturing equipment

Abstract

To provide a three-dimensional lamination molding device which can easily handle an exchange of an orifice.SOLUTION: A three-dimensional lamination molding device comprises a lens tube that houses a component for ejecting an electric charge particle beam toward a molding chamber, and forms a lens tube vacuum chamber. The lens tube comprises: a differential exhaust member that includes an orifice separating the lens tube vacuum chamber into an upstream side vacuum chamber and a downstream side vacuum chamber, and suppressing input and output of an air in those vacuum chambers; a separation wall having a concave part detachably receiving the differential exhaust member; an outer wall in which an open part communicating with the upstream side vacuum chamber is formed; a pressing member in which a base end part is detachably fixed to a neighbor of the open part, and which includes a pressing part for pressing the differential exhaust member to a tip end part; and a lid body that blocks the open part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional additive manufacturing apparatus. [Background technology]

[0002] In recent years, a three-dimensional additive manufacturing device has become known that irradiates a metal powder spread on a stage with a charged particle beam to melt and solidify the metal powder, and then stacks the solidified layers in sequence by moving the stage to form a three-dimensional object (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-174423 Summary of the Invention [Problem to be solved by the invention]

[0004] The 3D additive manufacturing apparatus includes a manufacturing chamber for forming a three-dimensional object and a lens barrel that houses components for emitting a charged particle beam toward the manufacturing chamber. The lens barrel forms a lens barrel vacuum chamber through which the charged particle beam passes. The charged particle beam enters the manufacturing chamber via the lens barrel vacuum chamber. When forming a three-dimensional object, the manufacturing chamber and the lens barrel vacuum chamber are each maintained in a vacuum state. The stage described above is also disposed inside the manufacturing chamber. The metal powder spread on the stage melts and solidifies when irradiated with the charged particle beam. During this process, the metal vapor and gas generated by the melting of the metal powder deteriorate the vacuum level in the manufacturing chamber. Furthermore, because the lens barrel vacuum chamber and the manufacturing chamber are connected to each other, a deterioration in the vacuum level in the manufacturing chamber also adversely affects the vacuum level in the lens barrel vacuum chamber. A deterioration in the vacuum level in the lens barrel vacuum chamber can lead to problems such as a shortened lifespan of the generator that generates the charged particle beam.

[0005] Therefore, in the three-dimensional additive manufacturing apparatus developed by the present applicant, the lens barrel vacuum chamber is divided into a first vacuum chamber, a second vacuum chamber, and a third vacuum chamber in the direction of emission of the charged particle beam, with the first vacuum chamber, in which the generator is located, being located at the most upstream position and the third vacuum chamber being located at the most downstream position. To achieve differential evacuation, an orifice is provided between the first and second vacuum chambers (at the boundary), and another orifice is provided between the second and third vacuum chambers (at the boundary). The degree of vacuum in the first vacuum chamber is set higher than that in the second vacuum chamber, and the degree of vacuum in the second vacuum chamber is set higher than that in the third vacuum chamber.

[0006] In the 3D additive manufacturing device configured as described above, the orifices prevent gas from flowing in and out between the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber, so that if the vacuum level in the manufacturing chamber deteriorates, it is possible to prevent the vacuum level in the first vacuum chamber from deteriorating as a result.

[0007] However, the present inventors have discovered that the three-dimensional additive manufacturing apparatus having the above-described configuration has a new problem, which will be explained in detail below. Inside the lens barrel, multiple electron lenses are arranged in series surrounding the third vacuum chamber to control the irradiation position of the charged particle beam, etc. Meanwhile, a powder supply mechanism is arranged in the fabrication chamber to spread metal powder on the stage. For this reason, the height dimension of the third vacuum chamber in the lens barrel is ensured to be long enough to accommodate the multiple electron lenses, and a large space is ensured above the stage in the fabrication chamber to accommodate the powder supply mechanism. Therefore, a sufficiently long distance is ensured between the stage arranged in the fabrication chamber and the second vacuum chamber of the lens barrel.

[0008] Furthermore, an orifice provided for differential pumping is designed based on a different design concept from an aperture provided for focusing a charged particle beam. Specifically, the diameter of the orifice is set to a value larger than the diameter of the charged particle beam passing through the orifice, and the diameter of the aperture is set to a value smaller than the diameter of the charged particle beam passing through the aperture. Therefore, while an aperture may be contaminated near the hole due to collision with the charged particle beam, an orifice is not hit by the charged particle beam and therefore does not have such a risk of contamination. Based on the above, the engineers (including the present inventor) involved in the design of the three-dimensional additive manufacturing device developed by the applicant recognized that there would be no particular problem in forming the orifice directly in the partition wall of the lens barrel.

[0009] However, after actually operating the 3D additive manufacturing device and then disassembling the inside of the lens barrel after a certain period of time, it was discovered that dirt had adhered around the orifice. Further investigation of the dirt revealed that it was a metal deposit. It was presumed that the metal deposit was formed when metal vapor generated by melting metal powder penetrated deeper into the third vacuum chamber than the engineers had anticipated, adhering to the periphery of the orifice, where it cooled and solidified. In light of these facts, the inventors gained new insight into the need for orifice maintenance and replacement, leading to the invention of this application.

[0010] An object of the present invention is to provide a three-dimensional additive manufacturing device that can easily accommodate maintenance and replacement of an orifice. [Means for solving the problem]

[0011] The present invention provides a three-dimensional additive manufacturing apparatus including a lens barrel that houses components for emitting a charged particle beam toward a manufacturing chamber and that forms a lens barrel vacuum chamber through which the charged particle beam passes. The lens barrel includes: a differential pumping member that divides the lens barrel vacuum chamber into an upstream vacuum chamber and a downstream vacuum chamber in the direction of emission of the charged particle beam and has an orifice that prevents gas from passing between the upstream vacuum chamber and the downstream vacuum chamber; a partition wall having a recess that detachably receives the differential pumping member; an outer wall that has an opening that communicates with the upstream vacuum chamber; a pressing member whose base end is detachably fixed near the opening and whose tip end has a pressing portion that presses the differential pumping member; and a cover that is detachably attached to the outer wall to close the opening. [Effects of the Invention]

[0012] According to the present invention, maintenance and replacement of the orifice can be easily performed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus according to a first embodiment of the present invention. [Figure 2] 1 is an enlarged longitudinal cross-sectional view of a portion of a three-dimensional additive manufacturing apparatus according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a plan view showing the arrangement of the differential pumping member and the pressing member. [Figure 4] FIG. 10 is an enlarged longitudinal cross-sectional view of a portion of a three-dimensional additive manufacturing apparatus according to a second embodiment of the present invention. [Figure 5] FIG. 10 is an enlarged longitudinal cross-sectional view of a portion of a three-dimensional additive manufacturing apparatus according to a third embodiment of the present invention. [Figure 6] FIG. 10 is an enlarged longitudinal cross-sectional view of a portion of a three-dimensional additive manufacturing apparatus according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

[0015] First Embodiment FIG. 1 is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus according to a first embodiment of the present invention. 1, a three-dimensional additive manufacturing apparatus 10 includes a manufacturing chamber 12 for forming a three-dimensional object, and a lens barrel 16 that houses components for emitting a charged particle beam 14 toward the manufacturing chamber 12. The charged particle beam 14 is, for example, an electron beam. A vacuum pump 18 is connected to the manufacturing chamber 12, and vacuum pumps 20 and 22 are connected to the lens barrel 16.

[0016] The manufacturing chamber 12 is a chamber for creating a vacuum state by evacuating the air inside the manufacturing chamber 12 using a vacuum pump 18. The manufacturing chamber 12 is equipped with a powder supply mechanism 24, a manufacturing table 26, a manufacturing box 28, a collection box 30, a stage 32, and a stage movement mechanism 34.

[0017] The powder supply mechanism 24 supplies metal powder 36, which is the powder material used to form the molded object, onto the molding table 26. The powder supply mechanism 24 has a hopper 24a, a powder dropper 24b, and a squeegee 24c. The hopper 24a is a container for storing metal powder. The powder dropper 24b is a device that drops the metal powder stored in the hopper 24a onto the molding table 26. The squeegee 24c is an elongated member that is long in the depth direction of FIG. 1. The squeegee 24c spreads the metal powder dropped by the powder dropper 24b over the molding table 26 and the stage 32. The squeegee 24c is movable back and forth in the left and right directions of FIG. 1 to uniformly spread the metal powder over the entire surfaces of the molding table 26 and the stage 32.

[0018] The modeling table 26 is arranged horizontally inside the modeling chamber 12. The modeling table 26 is arranged below the powder supply mechanism 24. The center of the modeling table 26 is open. The shape of the opening of the modeling table 26 is circular or angular in plan view.

[0019] The modeling box 28 is formed in a cylindrical shape. The modeling box 28 is arranged to surround the stage 32. The cross-sectional shape of the modeling box 28 is the same as the shape of the opening of the modeling table 26. For example, if the opening shape of the modeling table 26 is circular in a plan view, the cross-sectional shape of the modeling box 28 will also be circular. The upper end of the modeling box 28 is connected to the edge of the opening of the modeling table 26.

[0020] The collection box 30 is a box for collecting excess metal powder 36 from the metal powder 36 supplied onto the modeling table 26 by the powder supply mechanism 24. One collection box 30 is provided on each side of the movement direction of the squeegee 24c.

[0021] The stage 32 is provided so as to be movable in the vertical direction. The stage 32 moves in the vertical direction along the inner peripheral surface of the modeling box 28. A sealing member 38 is attached to the outer periphery of the stage 32. The sealing member 38 is a member that maintains sliding properties and airtightness between the outer periphery of the stage 32 and the inner peripheral surface of the modeling box 28. The sealing member 38 is made of a heat-resistant and elastic material.

[0022] The stage movement mechanism 34 is a mechanism that moves the stage 32 in the vertical direction. The stage movement mechanism 34 includes a shaft 34a and a drive unit 34b. The shaft 34a is connected to the underside of the stage 32. The drive unit 34b includes a motor and a power transmission mechanism (not shown), and drives the power transmission mechanism using the motor as a drive source to move the stage 32 together with the shaft 34a in the vertical direction. The power transmission mechanism is configured, for example, by a rack and pinion mechanism, a ball screw mechanism, or the like.

[0023] In the molding chamber 12 having the above-described configuration, a molded object is formed in the following procedure. First, the powder supply mechanism 24 spreads a layer of metal powder 36 on the stage 32. Next, the part inside the lens barrel 16 irradiates the metal powder 36 on the stage 32 with the charged particle beam 14. At this time, the part inside the lens barrel 16 is scanned with the charged particle beam 14 based on two-dimensional data obtained by slicing three-dimensional computer-aided design (CAD) data of the target object to a certain thickness. This melts and solidifies one layer of metal powder 36.

[0024] Next, the stage 32 is lowered by one layer by driving the stage moving mechanism 34. Thereafter, for the next layer, the metal powder 36 is spread and the charged particle beam 14 is irradiated in that order. This results in solidified layers of metal powder 36 being stacked. Thereafter, the above operation is repeated until the fabrication of the object is complete. The fabrication of the object is completed when the metal powder 36 has been melted and solidified for the number of layers required to fabricate the object. Through this procedure, the desired object is obtained.

[0025] The column 16 is mounted on the fabrication chamber 12. The column 16 houses a generator 40 that generates the charged particle beam 14 and an electron lens group 42 that controls the charged particle beam 14 generated by the generator 40. For example, if the charged particle beam 14 is an electron beam, the generator 40 is composed of an electron gun. The electron lens group 42 controls the refraction, convergence, scanning, etc. of the charged particle beam 14 using a magnetic field or an electric field.

[0026] The electron lens group 42 includes a first electron lens 44, a second electron lens 46, a third electron lens 48, and a fourth electron lens 50. The generator 40, the first electron lens 44, the second electron lens 46, the third electron lens 48, and the fourth electron lens 50 correspond to components for emitting the charged particle beam 14 toward the manufacturing chamber 12. The first electron lens 44 is housed in a first lens housing chamber 41 of the electron tube 16. The second electron lens 46, the third electron lens 48, and the fourth electron lens 50 are housed in a second lens housing chamber 43 of the electron tube 16.

[0027] The lens barrel 16 also forms a lens barrel vacuum chamber 52 through which the charged particle beam 14 passes. The lens barrel vacuum chamber 52 is a space formed by the main body (described later) of the lens barrel 16 together with the first lens housing chamber 41 and the second lens housing chamber 43 described above. The lens barrel vacuum chamber 52 is spatially connected to the manufacturing chamber 12. The lens barrel vacuum chamber 52 is divided into multiple (three in this embodiment) vacuum chambers in the emission direction Z of the charged particle beam 14 (the direction indicated by the arrow in the figure), namely, a first vacuum chamber 54, a second vacuum chamber 56, and a third vacuum chamber 58. In the emission direction Z of the charged particle beam 14, the first vacuum chamber 54 is located on the most upstream side, and the third vacuum chamber 58 is located on the most downstream side.

[0028] The generator 40 described above is housed in a first vacuum chamber 54. The vacuum pump 20 is connected to the first vacuum chamber 54, and the vacuum pump 22 is connected to a second vacuum chamber 56. The first electron lens 44 is disposed below an orifice 60 to surround the second vacuum chamber 56. The second electron lens 46, the third electron lens 48, and the fourth electron lens 50 are disposed below an orifice 62 to surround the third vacuum chamber 58. The first electron lens 44, the second electron lens 46, the third electron lens 48, and the fourth electron lens 50 are disposed in series in the emission direction Z of the charged particle beam 14.

[0029] An orifice 60 is provided between (at the boundary between) the first vacuum chamber 54 and the second vacuum chamber 56, and an orifice 62 is provided between (at the boundary between) the second vacuum chamber 56 and the third vacuum chamber 58. The two orifices 60, 62, together with the two vacuum pumps 20, 22, are provided to differentially evacuate the lens barrel vacuum chamber 52 of the lens barrel 16. The second vacuum chamber 56 is disposed between the two orifices 60, 62. In other words, the second vacuum chamber 56 is an intermediate chamber for differential evacuation. The orifice 60 prevents gas from flowing in and out between the first vacuum chamber 54 and the second vacuum chamber 56, and the orifice 62 prevents gas from flowing in and out between the second vacuum chamber 56 and the third vacuum chamber 58. The diameter of the orifice 62 is set to a size such that the charged particle beam 14 does not hit the orifice 62 when it passes through the orifice 62. This also applies to the orifice 60.

[0030] The column vacuum chamber 52 is formed to penetrate through the electron lens group 42. The column vacuum chambers 52 are differentially evacuated in the emission direction Z of the charged particle beam 14 so that the upstream vacuum chamber has a higher degree of vacuum than the downstream vacuum chamber. Specifically, the first vacuum chamber 54 is evacuated by the vacuum pump 20 to a first degree of vacuum higher than the second degree of vacuum, and the second vacuum chamber 56 is evacuated by the vacuum pump 22 to a second degree of vacuum higher than the third degree of vacuum. The third vacuum chamber 58 is evacuated by the vacuum pump 18 to a third degree of vacuum equivalent to that of the modeling chamber 12.

[0031] The main body of the optical column 16 is mainly composed of an outer wall 71, an upper wall 72, three partition walls 73, 74, and 75, and two inner walls 76 and 77. The outer wall 71 and the upper wall 72 separate the vacuum space formed inside the optical column 16 from the atmospheric space outside the optical column 16. The outer wall 71 is oriented parallel to the emission direction Z of the charged particle beam 14, and the upper wall 72 is oriented perpendicular to the emission direction Z of the charged particle beam 14. The outer wall 71 is arranged to surround the interior of the optical column 16, and therefore can be referred to as a side wall or a peripheral wall. The upper wall 72 is arranged at the top of the optical column 16 so as to close the upper opening of the outer wall 71.

[0032] The partition wall 73 is a wall that separates the first vacuum chamber 54 and the first lens housing chamber 41 in the emission direction Z of the charged particle beam 14. The partition wall 74 is a wall that separates the first lens housing chamber 41 and the second vacuum chamber 56 in the emission direction Z of the charged particle beam 14. The partition wall 75 is a wall that separates the second vacuum chamber 56 and the second lens housing chamber 43 in the emission direction Z of the charged particle beam 14.

[0033] The inner wall 76 is a wall that separates the second vacuum chamber 56 and the first lens housing chamber 41 in a direction perpendicular to the emission direction Z of the charged particle beam 14. The inner wall 76 is arranged in a direction parallel to the emission direction Z of the charged particle beam 14. The inner wall 77 is a wall that separates the third vacuum chamber 58 and the second lens housing chamber 43 in a direction perpendicular to the emission direction Z of the charged particle beam 14. Like the inner wall 76, the inner wall 77 is arranged in a direction parallel to the emission direction Z of the charged particle beam 14.

[0034] Inside the lens barrel 16 configured as described above, the charged particle beam 14 generated by the generator 40 passes through the lens barrel vacuum chamber 52. More specifically, the charged particle beam 14 generated by the generator 40 passes from the first vacuum chamber 54 through an orifice 60 to enter a second vacuum chamber 56, and then passes through an orifice 62 to enter a third vacuum chamber 58 and the fabrication chamber 12. In the fabrication chamber 12, the charged particle beam 14 forms a beam spot at the beam irradiation position on the stage 32, and is controlled by the electron lens group 42 so that this beam spot moves (scans) on the stage 32 based on the two-dimensional data.

[0035] If the orifice 62 were formed directly in the partition wall 75 of the lens barrel 16, when the area around the orifice 62 becomes dirty due to the adhesion of a metal deposition material, it would be necessary to disassemble at least half of the lens barrel 16 to remove the dirt. Furthermore, because the lens barrel 16 is mounted on top of the manufacturing chamber 12 and is heavy, disassembling the lens barrel 16 requires handling a heavy object at a high altitude. This would result in longer downtime for the 3D additive manufacturing device 10 due to maintenance and other reasons. Therefore, the first embodiment of the present invention employs the following configuration.

[0036] FIG. 2 is an enlarged longitudinal cross-sectional view of a portion of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. 2, the second vacuum chamber 56 is mainly defined by an outer wall 71, partition walls 74 and 75, and an inner wall 76. A differential pumping member 78 is attached to the partition wall 75, and an orifice 62 is formed in this differential pumping member 78. The differential pumping member 78 is a member that divides the lens barrel vacuum chamber 52 (see FIG. 1) into the second vacuum chamber 56 and the third vacuum chamber 58 in the emission direction Z of the charged particle beam 14. In this case, the second vacuum chamber 56 corresponds to the upstream vacuum chamber, and the third vacuum chamber 58 corresponds to the downstream vacuum chamber.

[0037] The differential pumping member 78 is a separate member from the partition wall 75 and is preferably made of a high-melting-point metal such as molybdenum or tungsten. The differential pumping member 78 has a predetermined thickness T and is formed in the shape of a flat plate. The differential pumping member 78 is also formed in a circular shape when viewed from the emission direction Z of the charged particle beam 14.

[0038] 3, the orifice 62 is formed in the center of the differential pumping member 78. The orifice 62 is formed in a circular shape when viewed from the emission direction Z of the charged particle beam 14. The hole diameter of the orifice 62 is as described above.

[0039] On the other hand, a recess 80 is formed in the partition wall 75. The recess 80 is a portion that receives the differential pumping member 78 in a positionable and detachable manner. The recess 80 is formed on the upper surface 75a of the partition wall 75. The recess 80 is circular when viewed from the emission direction Z of the charged particle beam 14, that is, it is formed in the same shape as the differential pumping member 78. The inner diameter of the recess 80 is slightly larger than the outer diameter of the differential pumping member 78.

[0040] The difference in size between the inner diameter of the recess 80 and the outer diameter of the differential pumping member 78 is set so as to satisfy at least the following conditions (a) and (b). (a) By fitting the differential pumping member 78 into the recess 80 , the differential pumping member 78 can be positioned so that the charged particle beam 14 passes through the orifice 62 . (b) The differential pumping member 78 can be attached to the recess 80 and removed from the recess 80 using tweezers or a dedicated jig. The recess 80 may be formed with a chamfered or tapered portion (not shown) to make it easier to receive the differential pumping member 78 . (c) In order to minimize the flow rate of gas passing through anything other than the orifice 62, the lower surface of the differential pumping member 78 and the seating surface of the recess 80 for the differential pumping member 78 can be in close contact with each other over a certain area or more.

[0041] The depth dimension (recess dimension) D of the recess 80 based on the upper surface 75a of the partition wall 75 is smaller than the thickness dimension T of the differential pumping member 78. Therefore, when the differential pumping member 78 is attached to the recess 80, a part of the differential pumping member 78 protrudes from the upper surface 75a of the partition wall 75. Therefore, when removing the differential pumping member 78 from the partition wall 75, the differential pumping member 78 can be easily taken out of the recess 80 by grasping the protruding portion of the differential pumping member 78 with tweezers or a dedicated jig or the like.

[0042] When the differential pumping member 78 is attached to the recess 80, the lower surface of the differential pumping member 78 and the bottom surface of the recess 80 are in close contact with each other at part F in FIG. 2 . Therefore, the gas passage between the second vacuum chamber 56 and the third vacuum chamber 58 is limited to the orifice 62. Furthermore, the orifice 62 is formed with a hole diameter that is sufficiently smaller than the inner diameter of the third vacuum chamber 58. Therefore, the orifice 62 prevents gas from entering or exiting between the second vacuum chamber 56 and the third vacuum chamber 58. Therefore, by evacuating the second vacuum chamber 56 with the vacuum pump 22, the degree of vacuum in the second vacuum chamber 56 can be maintained higher than the degree of vacuum in the third vacuum chamber 58. Furthermore, between the first vacuum chamber 54 and the second vacuum chamber 56, the gas passage is limited to the orifice 60, and the orifice 60 prevents gas from entering or exiting. Therefore, by evacuating the first vacuum chamber 54 with the vacuum pump 20, the degree of vacuum in the first vacuum chamber 54 can be maintained higher than the degree of vacuum in the second vacuum chamber 56. As a result, the degree of vacuum in the lens barrel vacuum chamber 52 can be maintained at different levels in stages by differential evacuation.

[0043] On the other hand, an opening 81 is formed in the outer wall 71 so as to penetrate the outer wall 71. The opening 81 is formed so as to lead to the second vacuum chamber 56. The opening 81 is formed to be large enough to allow the differential pumping member 78 held by tweezers, a jig, or the like (not shown) to be inserted into and removed from the second vacuum chamber 56. Incidentally, if the opening 81 is formed to be large enough to allow a person's hand to be inserted therein, it is possible to attach and detach the differential pumping member 78 to and from the recess 80 of the partition wall 75 through the opening 81 without using tweezers or the like.

[0044] A pressing member 82 and a lid 83 are attached to the outer wall 71. The pressing member 82 extends from the opening 81 in the outer wall 71 to the differential pumping member 78. The pressing member 82 has an integral pressing portion 84. The pressing portion 84 is a portion that presses the differential pumping member 78 attached to the recess 80 of the partition wall 75. The pressing member 82 is made of a leaf spring. As shown in FIG. 2, the pressing portion 84 is formed by being bent into a substantially V-shape when viewed from the side. The pressing portion 84 uses the spring properties of the pressing member 82 to elastically press the differential pumping member 78.

[0045] A notch 85 is formed in the pressing member 82. The pressing portions 84 are arranged on both sides of the notch 85 in the width direction Y of the pressing member 82, as shown in Fig. 3. In other words, the pressing portions 84 are formed in a bifurcated shape. The pressing member 82 presses the differential pumping member 78 from above with the pair of pressing portions 84, with the orifice 62 exposed through the notch 85. This makes it possible to avoid interference between the charged particle beam 14 passing through the orifice 62 and the pressing member 82 that presses the differential pumping member 78.

[0046] Furthermore, when the differential exhaust member 78 is held down by the holding member 82 as described above, the holding portion 84 is positioned on an imaginary center line 88 that is parallel to the width direction Y of the holding member 82 and passes through the center of the orifice 62, as shown in FIG. 3.

[0047] The pressing portion 84 is formed at the tip end of the pressing member 82 in the length direction X of the pressing member 82 (see FIG. 3), and a base end 86 is formed on the opposite side. The base end 86 of the pressing portion 84 is fixed to the outer wall 71 by a bolt 87. In addition, in the length direction X of the pressing member 82, the tip end of the pressing member 82 is disposed toward the center of the second vacuum chamber 56, and the base end 86 of the pressing member 82 is disposed toward the outer periphery of the second vacuum chamber 56. The base end 86 of the pressing member 82 is formed by being bent at a substantially right angle. A through hole 86a is provided in the base end 86. The through hole 86a is a hole for passing the male thread portion of the bolt 87 through.

[0048] A screw hole 71a is provided in the outer wall 71. The screw hole 71a is a hole for fixing a base end 86 of the holding member 82 to the outer wall 71 with a bolt 87. The screw hole 71a is disposed near the opening 81. The through hole 86a of the base end 86 is aligned with the screw hole 71a on the outer surface side of the outer wall 71, and in this state, the male thread portion of the bolt 87 passes through the through hole 86a and engages with the screw hole 71a. The head of the bolt 87 is disposed outward so that a tool such as a spanner or wrench can be easily fitted onto the head of the bolt 87. The base end 86 of the holding member 82 is fixed to the outer wall 71 when the bolt 87 is tightened, and is released from the fixation to the outer wall 71 when the bolt 87 is loosened. As a result, the base end 86 of the holding member 82 is detachably fixed near the opening 81. The holding member 82 extends obliquely downward from the base end 86 toward the holding portion 84.

[0049] The vicinity of the opening 81 to which the base end 86 of the pressing member 82 is fixed preferably refers to a position radially outward from a position spaced a distance of "L x 1 / 2" from the center of the orifice 62, more preferably a position radially outward from a position spaced a distance of "L x 2 / 3" from the center of the orifice 62, in the radial direction of the differential exhaust member 78 perpendicular to the emission direction Z of the charged particle beam 14, where L (mm) is the distance from the center of the orifice 62 to the outer surface of the outer wall 71.

[0050] When the base end 86 of the pressing member 82 is fixed to the outer wall 71 by the bolt 87 as in this embodiment, the base end 86 can be easily attached and detached by fixing the base end 86 near the opening 81. The attachment and detachment of the base end 86 described here refers to the work of tightening and loosening the bolt 87.

[0051] The lid 83 is attached to the outer wall 71 so as to close the opening 81. The lid 83 is fixed to the outer wall 71 with a plurality of bolts 89 (only two are shown in FIG. 2 ). A through hole 83a is provided in the lid 83. The through hole 83a is a hole for passing the male thread portion of the bolt 89. Meanwhile, a screw hole 71b is provided in the outer wall 71. Like the screw hole 71a described above, the screw hole 71b is arranged near the opening 81. The through hole 83a of the lid 83 is aligned with the screw hole 71b on the outer surface side of the outer wall 71, and in this state, the male thread portion of the bolt 89 passes through the through hole 83a and engages with the screw hole 71b. When the bolt 89 is tightened, the lid 83 is fixed to the outer wall 71, and when the bolt 89 is loosened, the lid 83 is released from the outer wall 71. In this way, the lid 83 is detachably attached to the outer wall 71.

[0052] A stepped portion 71c is formed on the outer surface of the outer wall 71. The screw holes 71a and 71b described above are formed in the recessed surface of the stepped portion 71c. The lid 83 is fitted into the stepped portion 71c. A groove 71d is formed in the stepped portion 71c, and a seal member 90 is attached to this groove 71d. The seal member 90 is a member that keeps the second vacuum chamber 56 airtight when the lid 83 is attached to the outer wall 71. For example, a rubber O-ring is used as the seal member 90.

[0053] In the three-dimensional additive manufacturing apparatus 10 configured as described above, if it becomes necessary to replace the orifice 62 for some reason, the following procedure can be followed. For ease of explanation, the differential pumping member 78 having the orifice 62 before replacement will be referred to as "78a," and the differential pumping member 78 having the orifice 62 after replacement will be referred to as "78b."

[0054] (Removal of the lid 83) First, the worker returns the pressure in the second vacuum chamber 56 to atmospheric pressure by venting. Next, the worker removes the bolts 89 that secure the lid 83. Next, the worker removes the lid 83 from the outer wall 71. This exposes the opening 81 to the outside.

[0055] (Removal of the holding member 82) Next, the worker removes the bolt 87 that secures the base end 86 of the holding member 82. Next, the worker removes the holding member 82 from the second vacuum chamber 56 through the opening 81. This completes the removal of the opening 81.

[0056] (Removal of differential exhaust member 78a) Next, the worker grasps the differential pumping member 78a with tweezers or a dedicated jig (not shown), and then removes the differential pumping member 78a from the second vacuum chamber 56 through the opening 81. This completes the removal of the differential pumping member 78a.

[0057] (Installation of differential exhaust member 78b) Next, the worker holds the differential pumping member 78b with tweezers or a dedicated jig (not shown), and then inserts the differential pumping member 78b into the second vacuum chamber 56 through the opening 81. Next, while still holding the differential pumping member 78b with the tweezers, the worker fits the differential pumping member 78b into the recess 80 of the partition wall 75. This positions the differential pumping member 78b. This completes the installation of the differential pumping member 78b.

[0058] (Installation of the holding member 82) Next, the worker inserts the pressing member 82 into the second vacuum chamber 56 through the opening 81. At this time, the worker brings the pressing portion 84 of the pressing member 82 into contact with the upper surface of the differential pumping member 78b, and in this state aligns the through-hole 86a of the base end portion 86 of the pressing member 82 with the screw hole 71a of the outer wall 71. This causes the pressing member 82 to elastically deform and generate a spring force, which causes the pressing portion 84 to press the differential pumping member 78b.

[0059] Next, the worker inserts the bolt 87 into the screw hole 71a through the through-hole 86a of the base end 86. Next, the worker tightens the bolt 87 with a predetermined force to fix the base end 86 of the holding member 82 to the outer wall 71. At this stage, the installation of the holding member 82 is complete. At this time, the worker can visually check the arrangement of the differential pumping member 78b and the holding member 82 in the second vacuum chamber 56 through the opening 81.

[0060] (Installation of the lid 83) Next, the worker closes the opening 81 with the lid body 83 by fitting the lid body 83 into the stepped portion 71c of the outer wall 71. Next, the worker inserts the bolt 89 through the through hole 83a of the lid body 83 and engages it with the screw hole 71b. Next, the worker tightens the bolt 89 with a predetermined force to secure the lid body 83 to the outer wall 71. At this time, the seal member 90 is pressed by the lid body 83 and elastically deforms, thereby sealing the second vacuum chamber 56. This completes the installation of the lid body 83.

[0061] The replacement of the orifice 62 is completed through the procedure described above. Replacement of the orifice 62 is primarily necessary when the area around the orifice 62 is contaminated by the adhesion of metal deposition, but it may be performed for other reasons. Alternatively, the differential pumping member 78 removed from the second vacuum chamber 56 using the procedure described above may be cleaned to remove any contamination such as metal deposition, and then the differential pumping member 78 may be returned to the second vacuum chamber 56 using the procedure described above. Furthermore, the differential pumping member 78 may be detached and attached to inspect whether any abnormalities have occurred in the differential pumping member 78, including the degree of contamination around the orifice 62. In other words, the attachment and detachment of the differential pumping member 78 is not limited to replacement of the orifice 62, and may also be performed for maintenance such as cleaning and inspection of the differential pumping member 78 including the orifice 62, or for other purposes.

[0062] As described above, in the three-dimensional additive manufacturing apparatus 10 according to the first embodiment of the present invention, the orifice 62 is formed in the differential pumping member 78 that separates the second vacuum chamber 56 and the third vacuum chamber 58, and the recess 80 that detachably receives the differential pumping member 78 is formed in the partition wall 75 of the lens barrel 16. In addition, in the three-dimensional additive manufacturing apparatus 10, the differential pumping member 78 attached to the recess 80 is held down by the holding member 82, and the base end 86 of the holding member 82 is fixed by the bolt 87 near the opening 81. The lid 83 is detachably attached to the outer wall 71 so as to close the opening 81. This allows the orifice 62 and the differential pumping member 78 to be replaced, and maintenance such as cleaning and inspection of the orifice 62 to be performed, simply by attaching and detaching the holding member 82 and the lid 83. Therefore, the three-dimensional additive manufacturing apparatus 10 allows for easy maintenance and replacement of the orifice 62. Furthermore, the differential pumping member 78 having the orifice 62 can be replaced in a short time, which significantly reduces downtime of the device due to maintenance, etc. of the three-dimensional additive manufacturing device 10. Furthermore, with the three-dimensional additive manufacturing device 10, by preparing differential pumping members 78 with orifices 62 having different diameters and / or shapes, it is possible to easily accommodate changes in the diameter and / or shape of the orifices 62.

[0063] Furthermore, in the three-dimensional additive manufacturing apparatus 10 according to the first embodiment, the base end 86 of the pressing member 82 is fixed to the outer wall 71 by a bolt 87. Therefore, the worker performing the work of attaching the pressing member 82 can visually check through the opening 81 whether the pressing portion 84 of the pressing member 82 is properly holding the differential exhaust member 78 during and / or after the attachment work. Furthermore, if the differential exhaust member 78 is not properly held down, for example, because the orientation of the pressing member 82 is shifted, the worker can redo the attachment work of the pressing member 82.

[0064] Furthermore, in the three-dimensional additive manufacturing device 10 according to the first embodiment, the pressing member 82 is configured using a leaf spring, which is an elastic body. This makes it possible to suppress variations in the force when the pressing portion 84 of the pressing member 82 presses the differential exhaust member 78.

[0065] Furthermore, in the three-dimensional additive manufacturing device 10 according to the first embodiment, the pressing portion 84 of the pressing member 82 is disposed on an imaginary center line 88 that passes through the center of the orifice 62. This allows the pressing member 82 to press the differential exhaust member 78 in a balanced and stable state.

[0066] Furthermore, in the three-dimensional additive manufacturing apparatus 10 according to the first embodiment, the depth dimension D of the recess 80 is smaller than the thickness dimension T of the differential pumping member 78, and therefore a part of the differential pumping member 78 is disposed protruding from the upper surface 75a of the partition wall 75. This allows the differential pumping member 78 to be easily removed from the recess 80 by grasping the protruding portion of the differential pumping member 78 with tweezers or the like.

[0067] The first vacuum chamber 54, located upstream of the orifice 60, is configured to be openable for maintenance of the generator 40 and the like, and since the orifice 60 is farther from the manufacturing chamber 12 than the orifice 62, it is less susceptible to deposition and other contaminants. Therefore, the orifice 60 may be formed in a differential pumping member, as in the case of the orifice 62, or may be formed directly in the partition wall 73. Furthermore, when the orifice 60 is formed in a differential pumping member, the differential pumping member may be attached to the partition wall 73 with bolts or the like, or may be held down by a holding member, as in the first embodiment. This also applies to other embodiments described below.

[0068] Second Embodiment FIG. 4 is an enlarged longitudinal cross-sectional view of a part of a three-dimensional additive manufacturing apparatus according to a second embodiment of the present invention. The three-dimensional additive manufacturing apparatus according to the second embodiment of the present invention differs from the first embodiment in the mounting structure of the presser member. Specifically, as shown in Fig. 4, a base end 860 of the presser member 820 is fixed to a lid body 830. A screw hole 830a is formed on the inner surface of the lid body 830. The screw hole 830a is a hole for fixing the base end 860 of the presser member 820 to the lid body 830 with a bolt 870. The screw hole 830a is formed so as not to penetrate the lid body 830. The screw hole 830a is also arranged near the opening 81.

[0069] Meanwhile, a through-hole 860a is provided in a base end 860 of the pressing member 820. The through-hole 860a is a hole for passing the male thread portion of a bolt 870 through. The through-hole 860a in the base end 860 is aligned with a screw hole 830a in the lid 830, and in this state, the male thread portion of the bolt 870 passes through the through-hole 860a and engages with the screw hole 830a. The base end 860 of the pressing member 820 is fixed to the lid 830 by tightening the bolt 870. A pressing portion 840 and a notch 850 are formed in the tip end of the pressing member 820. The shapes of the pressing portion 840 and the notch 850 are the same as those of the pressing portion 84 and the notch 85 in the first embodiment.

[0070] In the three-dimensional additive manufacturing device according to the second embodiment, when it becomes necessary to replace the orifice 62, the following procedure can be followed.

[0071] First, the worker returns the pressure in the second vacuum chamber 56 to atmospheric pressure by venting. Next, the worker removes the bolts 89 that secure the lid body 830. Next, the worker removes the lid body 830 from the outer wall 71. In this embodiment, the base end portion 860 of the pressing member 820 is fixed to the lid body 830. Therefore, the worker can remove the pressing member 820 and the lid body 830 at the same time.

[0072] Next, the worker performs the removal and installation of the differential exhaust member 78 in the same manner as in the first embodiment.

[0073] Next, the worker inserts the pressing member 820 into the second vacuum chamber 56 through the opening 81, and fits the lid body 830 onto the stepped portion 71c of the outer wall 71, thereby closing the opening 81 with the lid body 830. Next, the worker inserts the bolt 89 into the screw hole 71b through the through hole 83a of the lid body 830. Next, the worker tightens the bolt 89 with a predetermined force to secure the lid body 830 to the outer wall 71. This completes the installation of the pressing member 820 and the lid body 830.

[0074] As described above, in the three-dimensional additive manufacturing apparatus according to the second embodiment, the base end 860 of the pressing member 820 is fixed to the lid body 830 by the bolt 87. This allows the operator to handle the pressing member 820 and the lid body 830 as a single unit. This reduces the number of steps required for maintenance and replacement of the orifice 62.

[0075] Third Embodiment FIG. 5 is an enlarged longitudinal cross-sectional view of a part of a three-dimensional additive manufacturing apparatus according to a third embodiment of the present invention. The three-dimensional additive manufacturing apparatus according to the third embodiment of the present invention differs from the first embodiment in the configuration of the pressing member, which will be described in detail below. 5, the pressing member 821 has a base end 861 at one end in the length direction, and a through-hole 861a is provided in this base end 861. This is the same as in the first embodiment. However, unlike in the first embodiment, the pressing member 821 is made up of a cantilever beam 91 and a coil spring 92.

[0076] The cantilever beam 91 is made of, for example, a metal plate. A base end portion 861 of the pressing member 821 is formed at one end of the cantilever beam 91. Similarly to the first embodiment, the base end portion 861 of the pressing member 821 is fixed to the outer wall 71 by a bolt 87. A notch 93 is formed at the other end side (free end side) of the cantilever beam 91. The notch 93 is formed for the same purpose as the notch 85 (see FIG. 3) in the first embodiment.

[0077] The coil spring 92 is provided as an example of an elastic body. The upper end of the coil spring 92 is fixed to the tip (free end) of the cantilever beam 91 by, for example, welding or screwing. The coil spring 92 functions as a pressing portion that presses down the differential pumping member 78 attached to the recess 80. The lower end of the coil spring 92 contacts the upper surface of the differential pumping member 78 by the spring force of the coil spring 92 itself. The coil spring 92 is also arranged concentrically with the orifice 62 when viewed from the emission direction Z of the charged particle beam 14. This allows the differential pumping member 78 to be pressed down in a balanced and stable manner. The inner diameter of the coil spring 92 is set to be sufficiently larger than the diameter of the orifice 62 so that the charged particle beam 14 does not hit the coil spring 92.

[0078] According to the three-dimensional additive manufacturing device according to the third embodiment of the present invention, the same effects as those of the first embodiment can be obtained.

[0079] The lower end of coil spring 92 may be fixed to the upper surface of differential pumping member 78 by, for example, welding, screwing, or the like. When this configuration is adopted, the worker can handle presser member 821, which is made up of cantilever beam 91 and coil spring 92, and differential pumping member 78 as a single unit. Therefore, when removing presser member 821 from lens barrel 16, the worker can remove differential pumping member 78 together with presser member 821. Furthermore, when attaching presser member 821 to lens barrel 16, the worker can attach differential pumping member 78 together with presser member 821. Therefore, the worker does not need to hold differential pumping member 78 with tweezers or the like. Furthermore, the worker does not need to remove or attach differential pumping member 78 separately.

[0080] <Fourth embodiment> FIG. 6 is an enlarged longitudinal cross-sectional view of a part of a three-dimensional additive manufacturing apparatus according to a fourth embodiment of the present invention. The three-dimensional additive manufacturing apparatus according to the fourth embodiment of the present invention differs from the first embodiment in the configuration of the presser member. Specifically, as shown in FIG. 6 , the presser member 822 has an integral structure including a presser portion 842 and a base end portion 862. The presser member 822 is made of, for example, metal. The presser portion 842 presses down the differential pumping member 78 by contacting the upper surface of the differential pumping member 78. The presser member 822 also has a notch 852 formed therein to prevent the charged particle beam 14 from hitting the presser member 822. Meanwhile, a through-hole 862a is formed in a base end portion 862 of the presser member 822. The base end portion 862 is fixed to the outer wall 71 by a bolt 87, as in the first embodiment.

[0081] According to the three-dimensional additive manufacturing device according to the fourth embodiment of the present invention, maintenance and replacement of the orifice 62 can be easily performed, as in the case of the first embodiment.

[0082] The retaining portion 842 may be fixed to the upper surface of the differential pumping member 78 by, for example, welding, screwing, or the like. When this configuration is employed, the worker can handle the retaining member 822 and the differential pumping member 78 as a single unit. Therefore, when removing the retaining member 822 from the lens barrel 16, the worker can remove the differential pumping member 78 together with the retaining member 822. Furthermore, when attaching the retaining member 822 to the lens barrel 16, the worker can attach the differential pumping member 78 together with the retaining member 822. Therefore, the worker does not need to hold the differential pumping member 78 with tweezers or the like. Furthermore, the worker does not need to remove or attach the differential pumping member 78 separately.

[0083] <Modifications, etc.> The technical scope of the present invention is not limited to the above-described embodiments, but also includes forms in which various modifications and improvements are made within the scope that can derive specific effects obtained by the constituent elements of the invention and their combinations.

[0084] For example, in the first embodiment described above, a leaf spring is given as an example of an elastic body, and in the second embodiment described above, a coil spring 92 is given as an example of an elastic body, but the elastic body may be, for example, a laminated type spring in which multiple layers of corrugated spring plates are stacked, although this is not shown, or may be an elastic body other than a spring, such as a rubber-like elastic body.

[0085] In addition, in the first embodiment, the notch 85 is formed at the tip of the pressing member 82, but for example, a hole (not shown) may be formed instead of the notch 85. This also applies to the other embodiments.

[0086] Furthermore, in each of the above embodiments, the orifice 62 is formed in a circular shape, but this is not limiting, and the orifice 62 may be formed in a polygonal shape. In other words, the shape of the orifice 62 can be changed as desired. The same applies to the shape of the differential exhaust member 78.

[0087] Furthermore, in the first embodiment, the base end 86 of the pressing member 82 is fixed to the outer wall 71 by the bolt 87, but the present invention is not limited to this, and any structure may be employed as long as it is capable of fixing the base end 86 to the outer wall 71. For example, although not shown, a socket portion may be formed in the outer wall 71, and the base end 86 may be fixed to the outer wall 71 by inserting the base end 86 into this socket portion with a predetermined force. Alternatively, a socket portion may be formed in the outer wall 71, and the base end 86 may be fixed to the outer wall 71 by inserting a fixing pin into a through hole 86a of the base end 86 inserted into the socket portion. This also applies to the third and fourth embodiments.

[0088] In addition, in the above embodiment, a groove 71d is formed in the outer wall 71 and a sealing member 90 is attached to this groove 71d, but the sealing member 90 may also be attached to the lid body 83, or to both the outer wall 71 and the lid body 83.

[0089] In the above embodiment, two orifices 60, 62 are disposed in the lens barrel vacuum chamber 52 to divide the lens barrel vacuum chamber 52 into three vacuum chambers (first vacuum chamber 54, second vacuum chamber 56, and third vacuum chamber 58), but the present invention is not limited to this. In other words, the number of vacuum chambers into which the lens barrel vacuum chamber 52 is divided by the orifices can be changed as needed, and the number of orifices provided in the lens barrel 16 can also be changed. [Explanation of symbols]

[0090] 10...3D additive manufacturing device 12...Modeling room 14...Charged particle beam 16...Telescope tube 52...Tube vacuum chamber 54...1st vacuum chamber 56…Second vacuum chamber 58…Third vacuum chamber 60,62...Orifice 71...Exterior wall 75...Bulkhead 78...Differential pumping member 80...recess 81...Opening 82, 820, 821, 822...Pressing member 84, 840, 842...Pressing part 85, 93, 850, 852...Notches 86,860,861,862...Proximal end 92... Coil spring (holding part) 88...Imaginary center line Z…Emission direction

Claims

1. 1. A three-dimensional additive manufacturing apparatus comprising: a lens barrel that houses components for emitting a charged particle beam toward a manufacturing chamber and forms a lens barrel vacuum chamber through which the charged particle beam passes; The lens barrel comprises: a differential pumping member that divides the lens barrel vacuum chamber into an upstream vacuum chamber and a downstream vacuum chamber in the emission direction of the charged particle beam and has an orifice that prevents gas from passing between the upstream vacuum chamber and the downstream vacuum chamber; a partition wall that has a recess that detachably receives the differential pumping member; an outer wall that has an opening that communicates with atmospheric space and the upstream vacuum chamber; a pressing member that has a base end detachably fixed near the opening and a tip end that has a pressing portion that presses the differential pumping member; and a lid that is detachably attached to the outer wall so as to close the opening. 3D additive manufacturing equipment.

2. The base end of the pressing member is fixed to the outer wall. The three-dimensional additive manufacturing apparatus according to claim 1 .

3. The base end of the pressing member is fixed to the lid. The three-dimensional additive manufacturing apparatus according to claim 1 .

4. At least the pressing portion of the pressing member is made of an elastic material. The three-dimensional additive manufacturing apparatus according to claim 1 .

5. The pressing member is made of a leaf spring. The three-dimensional additive manufacturing apparatus according to claim 1 .

6. the orifice is provided in the center of the differential pumping member, The pressing member has a notch or a hole formed therein, The pressing portion presses the differential exhaust member while exposing the orifice through the notch or the hole. The three-dimensional additive manufacturing apparatus according to claim 1 .

7. The pressing portion is disposed on an imaginary center line passing through the center of the orifice. The three-dimensional additive manufacturing apparatus according to claim 6.

8. The depth of the recess is smaller than the thickness of the differential pumping member. The three-dimensional additive manufacturing apparatus according to claim 1 .

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