JP6645657B2 - Electron beam welding equipment - Google Patents

Description

  The present invention relates to an electron beam welding device and an orifice.

  There is an electron beam welding apparatus that irradiates a workpiece with an electron beam in a vacuum chamber and welds the workpiece. Patent Document 1 discloses an example of such an electron beam welding apparatus.

JP 2006-095553 A

  In the above-described electron beam welding apparatus, when the work is irradiated with the welding beam, the work is melted or evaporated, and sputter molecules are released. Such sputter molecules may adhere to the filament and have an undesirable effect on the electron beam welding equipment. The inventors of the present application have recalled that the electron beam welding apparatus described above is provided with a vacuum chamber having a filament and a sample chamber for accommodating a workpiece. However, sputter molecules could flow into the vacuum chamber.

  The present invention provides an electron beam welding apparatus capable of suppressing sputter molecules from flowing into a vacuum chamber having a filament.

The electron beam welding apparatus according to the present invention,
An electron gun for generating an electron beam;
A sample chamber in which the welding object to be irradiated with the electron beam is arranged,
The electron gun section,
A first vacuum chamber;
A second vacuum chamber connected to the first vacuum chamber via a first opening and provided on the sample chamber side with respect to the first vacuum chamber;
A first orifice provided in the first opening,
The first orifice suppresses sputter molecules generated from the welding object when the electron beam is irradiated on the welding object from flowing into the first vacuum chamber from the second vacuum chamber. It has a hole.

The orifice according to the present invention,
An electron gun for generating an electron beam;
A sample chamber in which the welding object to be irradiated with the electron beam is arranged,
The electron gun section,
A first vacuum chamber;
A second vacuum chamber connected to the first vacuum chamber via a first opening and provided on the sample chamber side with respect to the first vacuum chamber;
An orifice provided in the first opening, wherein the orifice is provided in the first opening,
There is a hole for suppressing sputter molecules generated from the welding object when the electron beam is irradiated on the welding object from flowing into the first vacuum chamber from the second vacuum chamber.

  ADVANTAGE OF THE INVENTION According to the electron beam welding apparatus concerning this invention, it can suppress that a sputter molecule flows into the vacuum chamber which has a filament.

FIG. 2 is a cross-sectional view schematically illustrating the electron beam welding apparatus according to the first embodiment. FIG. 2 is a cross-sectional view schematically illustrating a main part of the electron beam welding apparatus according to the first embodiment. FIG. 2 is a cross-sectional view schematically illustrating a main part of the electron beam welding apparatus according to the first embodiment. FIG. 2 is a diagram schematically illustrating a locus of sputter molecules in the electron beam welding apparatus according to the first embodiment. FIG. 2 is a diagram schematically showing a locus of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment. FIG. 2 is a diagram schematically showing a locus of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment. FIG. 3 is a diagram schematically illustrating movement of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment. FIG. 3 is a diagram schematically illustrating movement of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment. FIG. 3 is a diagram schematically illustrating movement of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment. FIG. 3 is a diagram schematically illustrating movement of sputter molecules in a main part of the electron beam welding apparatus according to the first embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and a repeated description will be omitted as necessary.

Embodiment 1
The electron beam welding apparatus 100 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically showing an electron beam welding apparatus according to the first embodiment. 2 and 3 are cross-sectional views schematically showing main parts of the electron beam welding apparatus according to the first embodiment. 1 to 6, the right-handed xyz coordinates are defined. That is, in FIGS. 1 to 6, the horizontal direction in the drawing is the X direction, and the vertical direction in the drawing is the Z direction.

  The electron beam welding apparatus 100 includes an electron gun unit 110, a sample chamber 120, a turbo molecular pump (TMP) 162, a turbo molecular pump (TMP) 164, a mechanical booster pump (MP) 165, and a rotary pump (RP) 166.

  The turbo molecular pump (TMP) 162 is also called a first vacuum pump. The turbo molecular pump (TMP) 164 is also called a second vacuum pump. Although a turbo molecular pump is used as the first and second vacuum pumps in this embodiment, other types of vacuum pumps such as a diffusion pump (diffusion pump) may be used. Similarly, the mechanical booster pump (MP) 165 and the rotary pump (RP) 166 may be replaced with another type of vacuum pump.

  The electron gun unit 110 and the sample chamber 120 are connected via an opening 153 to form an integrated vacuum device (vacuum chamber). The electron gun unit 110 emits an electron beam 140 toward the sample chamber 120. The electron gun section 110 is evacuated by two turbo molecular pumps 162 and 164. The sample chamber 120 is evacuated by a cascade-connected mechanical booster pump (MP) 165 and a rotary pump (RP) 166.

  The electron gun section 110 has vacuum chambers VC1 to VC3, a filament 111, a grid 112, an anode 113, an alignment coil 114, a lens coil 115, a deflection coil 116, and a vacuum valve 118.

  The vacuum chambers VC1 to VC3 and the sample chamber 120 are cascaded and connected in the Z direction.

  The filament 111 and the grid 112 are arranged in the vacuum chamber VC1. One end of the filament 111 is connected to the positive electrode of the DC power supply 130, and the other end is connected to the negative electrode of the DC power supply 130. As a result, a DC voltage is applied to the filament 111, and a current flows. The filament 111 is heated by Joule heat caused by the flow of electric current, and emits thermoelectrons. The vacuum chamber VC1 is evacuated by a turbo-molecular pump 162 connected via the opening 161.

  After passing through the grid 112, the thermoelectrons emitted from the filament 111 are given an accelerating voltage by an anode 113 described later, and become an electron beam 140. The grid 112 is configured to have a high potential with respect to the filament 111. By increasing the voltage between the grid 112 and the filament 111, the beam current of the electron beam 140 can be controlled. The electron beam 140 is guided from the vacuum chamber VC1 to the sample chamber 120 via the vacuum chambers VC2 and VC3 along the path B1.

  The vacuum chamber VC1 and the vacuum chamber VC2 are connected via an opening 151, and an orifice 171 is provided in the opening 151. Specifically, the opening 151 has a vacuum chamber VC1 side and a vacuum chamber VC2 side. It is provided to connect. The electron beam 140 is guided from the vacuum chamber VC1 to the vacuum chamber VC2 via the orifice 171.

  As shown in FIGS. 1 and 2, the orifice 171 has a hole 171 a through which the electron beam 140 can pass, and the hole 171 a has a smaller cross-sectional area than the opening 151. The cross-sectional shape of the hole 171a is, for example, a circular shape, but is not limited to a circular shape, and may be a variety of shapes such as an ellipse and a polygon. At least one return portion 171b is provided on the inner wall surface of the hole 171a. The return portion 171b is a plate-like portion protruding from the inner wall surface of the hole 171a, and is inclined toward the sample chamber 120 (in FIG. 2, the minus side in the Z-axis direction). The height of the return portion 171b, that is, the distance from the inner wall surface of the hole 171a to the tip of the return portion 171b may be larger than the later-described sputter molecule M4 (see FIG. 6).

  When one of the vacuum chambers VC1 and VC2 has a higher degree of vacuum than the other, the orifice 171 maintains the vacuum degree of the high-vacuum-side high-vacuum chamber while maintaining a low-vacuum low-vacuum state. Of spatter into the vacuum chamber on the side. The hole 171a of the orifice 171 only needs to have a shape that suppresses a later-described sputter molecule M4 (see FIG. 6) from flowing from the vacuum chamber VC2 to the vacuum chamber VC1, and for example, a cross-sectional area of such a size. Having.

  Further, the longer the orifice 171 is in the longitudinal direction (here, the Z-axis direction), the more the flow of the sputtered molecules M4 from the vacuum chamber VC2 to the vacuum chamber VC1 can be suppressed. For this reason, the length of the orifice 171 in the longitudinal direction is set to a length that allows other components of the electron beam welding apparatus 100, for example, the grid 12 and the vacuum valve 118 to secure necessary functions in the electron beam welding apparatus 100. More specifically, for example, it may be from the grid 112 or its vicinity to the vacuum valve 118 or its vicinity.

  The orifice 171 may be made of a material that has heat resistance necessary for the passage of the electron beam and is less likely to be magnetized. For example, the orifice 171 may be made of austenitic stainless steel. As such austenitic stainless steel, for example, there is a steel corresponding to SUS304 defined in JIS standards.

  The vacuum chamber VC2 and the vacuum chamber VC3 are connected via the opening 152, and the orifice 172 is provided in the opening 152, and more specifically, is provided on the opening 152 on the side of the vacuum chamber VC3. The electron beam 140 is guided from the vacuum chamber VC2 to the vacuum chamber VC3 via the orifice 172.

  As shown in FIGS. 1 and 3, the orifice 172 has holes 172a, 172b, and 172c through which the electron beam 140 can pass, and the holes 172a, 172b, and 172c are formed from the filament 111 side toward the sample chamber 120. They are continuous in order and pass through the orifice 172. The holes 172a, 172b, 172c have a smaller cross-sectional area than the opening 152. Specifically, the hole 172c has a circular cross-sectional shape having a diameter X3, the hole 172b has a circular cross-sectional shape having a diameter X2, and the hole 172a has a circular cross-sectional shape having a diameter X1. Have.

  The cross-sectional shape of the holes 172a, 172b, 172c is not limited to a circular shape, but may be various shapes such as an ellipse and a polygon. The diameters X1, X2, X3 are smaller in this order. The hole 172a has a smaller cross-sectional area than the hole 172b, and the hole 172b has a smaller cross-sectional area than the hole 172c. The cross-sectional area of the continuous holes 172c, 172b, 172a of the orifice 172 may be gradually reduced from the sample chamber 120 side to the filament 111 side, and more specifically, is gradually reduced in this order.

  Further, similarly to the orifice 171, the longer the orifice 172 is in the longitudinal direction (here, the Z-axis direction), the more the flow of the sputtered molecule M2 from the vacuum chamber VC3 to the vacuum chamber VC3 can be suppressed. Therefore, the length in the longitudinal direction of the orifice 172 is set to a length that allows other components of the electron beam welding apparatus 100, for example, the lens coil 115 and the deflection coil 116 to secure the functions necessary for the electron beam welding apparatus 100. I just need. Specifically, the length of the orifice 172 in the longitudinal direction may be determined so that the tip of the orifice 172 has the same height as the lens coil 115 (here, the position in the Z-axis direction).

  When one of the vacuum chambers VC2 and VC3 has a higher degree of vacuum than the other, the orifice 172 retains the degree of vacuum of the high-vacuum chamber on the high-vacuum side while maintaining a low degree of vacuum with a low degree of vacuum. Of spatter into the vacuum chamber on the side. The hole 172a of the orifice 172 only needs to have a shape that suppresses a later-described sputter molecule M2 (see FIG. 5) from flowing into the vacuum chamber VC2 from the vacuum chamber VC3. Having. Orifice 172 may be made of the same type of material as orifice 171.

  The vacuum chamber VC3 and the sample chamber 120 are connected via an opening 153, and the electron beam 140 is guided from the vacuum chamber VC3 to the sample chamber 120 via the opening 153.

  Here, the vacuum chamber VC1 is also referred to as a first vacuum chamber. The vacuum chamber VC2 is also called a second vacuum chamber. The vacuum chamber VC3 is also called a third vacuum chamber. Further, the vacuum chamber VC2 and the sample chamber 120 are connected via the vacuum chamber VC3, but this connection state is also described simply as the connection between the vacuum chamber VC2 and the sample chamber 120. The orifice 171 is also called a first orifice, and the orifice 172 is also called a second orifice. The opening 151 is also referred to as a first opening, and the opening 152 is also referred to as a second opening.

  An anode 113 is disposed inside the vacuum chamber VC2. The anode 113 is disposed in the opening 151 in the vacuum chamber VC2. A vacuum valve 118 is provided in an opening 152 between the vacuum chamber VC2 and the vacuum chamber VC3. The vacuum valve 118 opens or shuts off the space between the vacuum chamber VC2 and the vacuum chamber VC3. The vacuum chamber VC2 is evacuated by a turbo-molecular pump 164 connected via the opening 163.

  An alignment coil 114, a lens coil 115, and a deflection coil 116 are arranged in the vacuum chamber VC3. In the vacuum chamber VC3, the lens coil 115 and the deflection coil 116 are separated by a wall VC31. Of the space partitioned by the wall VC31, the space having the lens coil 115 and the deflection coil 116 may be under atmospheric pressure. The alignment coil 114 determines the origin position of the beam spot of the electron beam 140. The lens coil 115 determines the size of the beam spot of the electron beam 140. The deflection coil 116 controls the irradiation position of the electron beam 140 on the welding target.

  An object to be welded (members W1 and W2 in this example) is arranged in the sample chamber 120. The sample chamber 120 is constantly evacuated by a vacuum pump (mechanical booster pump (MP) 165, rotary pump (RP) 166) during the welding operation. In this example, the joint between the member W1 and the member W2 is irradiated with the electron beam 140 to form a molten metal portion 141 in which the member W1 and the member W2 are fused. As the molten metal part 141 cools and solidifies, the member W1 and the member W2 are welded.

  Next, with reference to FIGS. 1 and 4 to 10, the principle of suppressing the flow of sputter molecules into the vacuum chamber VC1 in the electron beam welding apparatus 100 according to the present embodiment will be described. FIG. 4 is a diagram schematically illustrating a locus of sputter molecules in the electron beam welding apparatus according to the first embodiment. FIGS. 5 and 6 are diagrams schematically showing the trajectories of sputter molecules in the electron beam welding apparatus according to the first embodiment. 7 to 10 are diagrams schematically showing movement of sputter molecules in the main part of the electron beam welding apparatus according to the first embodiment.

  When the members W1 and W2 are irradiated with the electron beam 140, metal atoms forming the members W1 and W2 are emitted as sputter molecules into the sample chamber 120 by the energy of the electron beam 140. As shown in FIG. 4, some sputtered molecules M2 emitted from the members W1 and W2 are drawn toward the filament 111 having a lower potential, and follow the path B2 opposite to the electron beam 140 to the filament 111. Then, it enters the hole 172c of the orifice 172. The remaining sputtered molecules M1 emitted from the members W1 and W2 do not go straight (accurately along the Z axis) to the filament 111 but go to the filament 111 at an angle to the Z axis. The sputter molecule M1 adheres to the outer portion of the hole 172c (see FIG. 3) in the orifice 172, the inner wall of the vacuum chamber VC3, or the wall VC31, or floats in the vacuum chamber VC3. Thus, the remaining sputter molecules M1 are collected by the vacuum chamber VC3 and the orifice 172.

  As shown in FIG. 5, a part of the sputtered molecule M2 that has entered the hole 172c of the orifice 172 passes through the hole 172b and the hole 172a and enters the vacuum chamber VC2. A part of the sputtered molecule M2 collides with any one of the inner wall surface of the hole 172c, the inner wall surface of the hole 172b, and the inner wall surface of the hole 172a and rebounds. May enter. The remainder of the sputtered molecule M2 that has entered the hole 172c adheres to any one of the inner wall surface of the hole 172c, the inner wall surface of the hole 172b, and the inner wall surface of the hole 172a. Since the cross-sectional area of the continuous holes 172c, 172b, 172a of the orifice 172 gradually decreases, the remainder of the sputtered molecules M2 easily adhere to the inner wall surfaces of the holes 172c, 172b, 172a. Thus, the rest of the sputtered molecules M2 are collected by the orifice 172.

  As shown in FIGS. 4 and 6, a part of the sputter molecules M3 that have entered the vacuum chamber VC2 pass through the vacuum chamber VC2 and enter the holes 171a of the orifice 171 (see FIG. 6). On the other hand, the remainder of the sputtered molecule M3 does not go straight (accurately along the Z-axis) to the hole 171a of the orifice 171, but goes to the filament 111 side at a certain angle with respect to the Z-axis. It adheres to the outer part or the inner wall of the vacuum chamber VC2, or collides with and drifts inside the vacuum chamber VC2. The remainder of these sputter molecules M3 may be exhausted to the outside of the vacuum chamber VC2 by exhaustion by the turbo molecular pump 164. As a result, the remaining sputter molecules M3 are collected by the vacuum chamber VC2 and the turbo molecular pump 164.

  Part of the sputtered molecules M4 that have entered the hole 171a collide with and adhere to the inner wall surface of the hole 171a. On the other hand, the remainder of the sputtered molecules M4 that have entered the hole 171a are collected by the inner wall surface of the hole 171a and the return portion 171b.

  Next, the collection of a part of the sputtered molecule M4 will be specifically described with reference to FIGS. As shown in FIG. 7, a part of the sputtered molecules M4 that have entered the hole 171a advances, for example, along the trajectory A1 toward the inner wall surface of the hole 171a and the return portion 171b. Here, the angle formed between the inner wall surface of the hole 171a and the return portion 171b is α.

  Subsequently, as shown in FIG. 8, the remaining sputtered molecules M4 collide with the return portion 171b. Here, when the sputtered molecules collide with the wall surface in the vacuum region, they are specularly reflected. When the sputtered molecules further collide with the wall surface, they are specularly reflected again. That is, the sputtered molecule repeats regular reflection every time it collides with the wall surface. Therefore, after colliding with the return portion 171b, the sputtered molecule M4 specularly reflects, moves along the trajectory A2, and proceeds toward the inner wall surface of the hole 171a. Further, the sputtered molecule M4 collides with the inner wall surface of the hole 171a, is specularly reflected, and proceeds toward the return portion 171b along the trajectory A3.

  The angle α formed between the inner wall surface of the hole 171a and the return portion 171b is preferably larger than 0 ° and smaller than 90 °. This is because the sputtered molecules collide with the return portion 171b and are specularly reflected, travel toward the inner wall surface of the hole 171a, and more reliably collect the sputtered molecules by the orifice 172.

  Subsequently, as shown in FIG. 9, the sputtered molecule M4 collides with the return portion 171b, is specularly reflected, and travels along the trajectory A4 toward the inner wall surface of the hole 171a.

  Subsequently, as shown in FIG. 10, the sputtered molecule M4 collides with the inner wall surface of the hole 171a, is specularly reflected, and proceeds toward the return portion 171b along the trajectory A5. As described above, the sputtered molecule M4 reaches the intersection or the vicinity of the inner wall surface of the hole 171a or the return portion 171b by repeating the collision and regular reflection with the inner wall surface of the hole 171a or the return portion 171b. Attached. Thereby, the sputtered molecules M4 are collected by the inner wall surface of the hole 171a and the return portion 171b.

  As described above, in the electron beam welding apparatus 100, sputter molecules are collected by the vacuum chamber VC3, the orifice 172, the vacuum chamber VC2, the turbo molecular pump 164, and the orifice 171. To prevent inflow. Therefore, the flow of sputter molecules into the vacuum chamber VC1 is suppressed. In addition, maintenance and cleaning of the vacuum chamber VC1 are improved.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist. For example, the orifice 172 may be provided in the opening 151 instead of the orifice 171, or the orifice 171 may be provided in the opening 152 instead of the orifice 172. Alternatively, the orifice 172 may be provided in the opening 151 and the orifice 171 may be provided in the opening 152. Further, the orifice 172 may further include a return portion, similarly to the orifice 171. Also, while the orifice 171 has the return portion 171b, the cross-sectional area of the hole 171a may be gradually reduced from the sample chamber 120 side toward the filament 111 side similarly to the orifice 172, for example, stepwise. May be reduced.

Reference Signs List 100 electron beam welding apparatus 110 electron gun section 111 filament 120 sample chamber 140 electron beam 151, 152, 153 opening section 164 turbo molecular pump 171 orifice 171a hole 171b return section 172 orifice 172a, 172b, 172c hole M1, M2, M3, M4 Sputtered molecules VC1, VC2, VC3 Vacuum chamber W1, W2 Member α angle

Claims (3)

An electron gun for generating an electron beam;
A sample chamber in which the welding object to be irradiated with the electron beam is arranged,
The electron gun section,
A first vacuum chamber;
A second vacuum chamber connected to the first vacuum chamber via a first opening and provided on the sample chamber side with respect to the first vacuum chamber;
A first orifice provided in the first opening;
A third vacuum chamber connected to the second vacuum chamber via a second opening and provided on the sample chamber side with respect to the second vacuum chamber;
A second orifice provided in the second opening ,
The first orifice suppresses sputter molecules generated from the welding object when the electron beam is irradiated on the welding object from flowing into the first vacuum chamber from the second vacuum chamber. a hole to possess,
The second orifice suppresses sputter molecules generated from the welding object when the electron beam is irradiated on the welding object from flowing into the second vacuum chamber from the third vacuum chamber. Has a hole to
The inner wall surface of the hole of the first orifice, and the inner wall surface of the hole of the second orifice have a smaller cross-sectional area from the sample chamber side toward the first vacuum chamber side,
The first orifice or the second orifice has a return portion,
The electron beam welding device , wherein the return portion protrudes from the inner wall surface of the hole of the first orifice having the return portion or the second orifice . The electron beam welding apparatus according to claim 1, further comprising a vacuum pump that exhausts the second vacuum chamber. Wherein said return part, the first orifice having a return part, or the second angle α formed by the front Kiana inner wall surface of the orifice greater than 0 °, less than 90 ° The electron beam welding apparatus according to claim 1 or 2 , wherein

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