How to remove a weld bead

Abstract

To enable removal of bead in a molten condition.SOLUTION: A removal method of weld bead comprises the step of: (a) preparing a scraper whose material has a melting temperature higher than a melting temperature of a base material that is an object of weldment and a melting temperature of a weld rod; (b) generating molten pool where the base material and the weld rod are melt together by heating the base material and the weld rod at a temperature lower than the melting temperature of the scraper; (c) separating at least a part of materials configuring a bulge part that protrudes from the molten pool relative to a surface of the base material of the bead through moving the scraper toward the bulge while the molten pool is melt; and (d) discharging at least a part of materials in a rear direction opposite to the front direction where the scraper moves in the step (c) through moving the scraper along a second face in an opposite direction to a first face where the scraper faces the base material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for removing a weld bead. [Background technology]

[0002] As a technique for removing beads generated by welding, for example, a removal method using a cutting tool is known, as described in Patent Document 1. The removal method of Patent Document 1 is a method in which unnecessary beads are scraped off with a cutting tool when the beads are in a solidified state after welding.

[0003] The removal of the bead is generally performed by using a rotary cutting tool. Specifically, an end mill is used as the cutting tool. In this bead removal, when removing the solidified bead, the removed bead may be welded to the cutting tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-124782 A Summary of the Invention [Problem to be solved by the invention]

[0005] Rotary cutting tools require a drive system to rotate the cutting tool. In addition, rotary cutting tools scatter chips around the tool as they cut the bead while rotating. In order to recycle the material, the scattered chips need to be collected. Therefore, scattering chips makes the bead removal process, including collection, more difficult.

[0006] In addition, the above technology requires waiting for the bead to solidify, which lengthens the product cycle time. Furthermore, the lower the temperature of the bead, which is mainly composed of aluminum or soft iron, the more likely it is to adhere to the cutting tool during removal. Therefore, when removing the bead, a coolant liquid is sprayed on the cutting tool, which requires work to prevent adhesion.

[0007] Therefore, there has been a demand for a technology that can remove the molten bead without extending the cycle time and without the need to prevent welding. Furthermore, there has been a demand for this removal technology that uses a cutting tool that does not require a driving facility and does not scatter cutting chips. [Means for solving the problem]

[0008] The present disclosure can be realized in the following forms.

[0009] (1) According to one embodiment of the present disclosure, there is provided a method for removing a weld bead, comprising the steps of: (a) preparing a scraper made of a material having a melting point higher than that of a base metal to be welded and that of a welding rod; (b) heating the base metal and the welding rod at a temperature lower than the melting point of the scraper to generate a molten pool in which the base metal and the welding rod are fused together; (c) moving the scraper from the molten pool to a protruding portion of the bead that is higher than the surface of the base metal by the scraper while the molten pool is molten, and separating at least a portion of the material constituting the protruding portion from the base metal by the scraper; and (d) discharging the at least a portion of the material in a direction opposite to the direction of movement of the scraper in the step (c), that is, backward, opposite to the forward direction of movement of the scraper. This embodiment can shorten the cycle time compared to an embodiment in which the raised portion is removed after the bead has cooled. Furthermore, the raised portion can be removed from the base material without rotating the cutting tool. Therefore, the raised portion that has left the base material can be removed without scattering. Furthermore, the raised portion that has left the base material is discharged behind the scraper. Therefore, it is easier to collect the raised portion compared to a case in which the raised portion that has left the base material scatters around. (2) In the removal method of the above form, the scraper may further have a third surface arranged on the opposite side to the first surface, and the rear edge of the second surface may be arranged above and behind the front edge of the third surface in the position of the scraper during the movement, and the step (d) may include a step of solidifying at least a portion of the material flowing over the scraper by the movement of the scraper, behind the rear edge of the second surface and above the third surface. By adopting such an embodiment, the raised portion in a molten state can be solidified on the scraper. That is, the removed bead can be recovered at a lower temperature than the raised portion in a molten state. Therefore, compared to when recovering the raised portion in a molten state, there is no temperature restriction and the bead can be easily recovered. Furthermore, compared to when recovering the raised portion in a solidified state, since the raised portion is removed at a higher temperature, welding between the scraper and the raised portion is less likely to occur. That is, the work of preventing welding can be reduced. (3) In the above-described removal method, the scraper may be provided with a recovery section behind the second surface for recovering the material removed by the scraper, and the method may further include, after step (d), a step (f) of recovering at least a portion of the material discharged as the removed material by the recovery section. By adopting such an embodiment, the removed raised portion can be collected by a scraper, thereby reducing the risk of the removed raised portion falling onto the base material. (4) In the removal method of the above embodiment, the scraper may have a protrusion protruding from the first surface, and step (c) may include a step of abutting a tip of the protrusion against a surface of the base material to smooth out any irregularities on the surface of the molten pool from which the material has been detached. By adopting such an embodiment, it is possible to reduce the roughness of the surface of the bead after the bead is removed. (5) In the removal method according to the above aspect, the welding may be performed for the manufacture of a battery. When used in welding for battery manufacturing, it can prevent defects caused by interference between the weld bead and parts. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of a device for removing a weld bead. [Diagram 2] FIG. 2 is an explanatory diagram showing the shape of a scraper 200. [Diagram 3] FIG. 2 is an explanatory diagram showing removal of a bead by a scraper 200. [Figure 4] 13 is an explanatory diagram showing the discharge of the removed material Wb13 by the scraper 200. FIG. [Diagram 5] 1 is a flow chart showing steps of a method for removing a weld bead. [Figure 6] 1 is an explanatory diagram showing the generation of a molten pool Wb10 by arc welding. [Figure 7] 13 is an explanatory diagram showing a scraper 200 moving toward a molten pool Wb10. FIG. [Figure 8] FIG. 2 is an explanatory diagram showing the end of welding with the welding rod 100. [Figure 9] 1 is an explanatory diagram showing a base material Ob after removal of beads. FIG. [Figure 10] FIG. 2 is an explanatory diagram showing the configuration of an apparatus 10a equipped with a scraper 200a. [Figure 11] 13 is an explanatory diagram showing collection of the removed matter Wb13 by the collection section 280. FIG. [Figure 12]13 is a flowchart showing the process of recovering the removed matter Wb13 by the recovery unit 280. [Figure 13] FIG. 13 is an explanatory diagram showing the configuration of an apparatus 10b equipped with a scraper 200b. [Figure 14] 13 is an explanatory diagram showing a protrusion 290 of a scraper 200b. FIG. [Figure 15] 10 is an explanatory diagram showing the relationship between a protrusion 290 and a molten pool Wb10. FIG. [Figure 16] 13 is a flowchart showing a process of leveling the molten pool Wb12 by the protrusion 290. [Figure 17] FIG. 2 is an explanatory diagram showing a cooling path 241. [Figure 18] FIG. 13 is an explanatory diagram showing the configuration of an apparatus 10d equipped with a scraper 200d. [Figure 19] FIG. 1 is an explanatory diagram showing the configuration of an apparatus 10e equipped with a scraper 200e. [Figure 20] FIG. 13 is an explanatory diagram showing the configuration of an apparatus 10f equipped with a scraper 200f. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A. First embodiment: A1. Equipment configuration: 1 is an explanatory diagram showing a device configuration for removing a weld bead according to a first embodiment of the present disclosure. In the following description, the z-axis direction is the vertical direction. The x-axis direction is the direction of arrow AM10, which is the bead removal direction. The direction of arrow AM10 will be described in detail later. The y-axis direction is the direction perpendicular to the z-axis and x-axis.

[0012] The apparatus 10 shown in FIG. 1 welds a base metal Ob and removes a bead produced by welding. The welding performed by the apparatus 10 is consumable electrode welding. Specifically, it is MIG welding. In the welding performed by the apparatus 10, the base metal Ob is, for example, aluminum. The melting point Tm1 of the base metal Ob is about 660° C. when the material is aluminum. The apparatus 10 includes a welding rod 100, a scraper 200, and a support 300.

[0013] The welding rod 100 generates a molten pool Wb10 in which the base material Ob and the welding rod 100 are fused together by heating the base material Ob and the welding rod 100 itself at a temperature Tm4 lower than the melting point Tm3 of the scraper 200. More specifically, the welding rod 100 generates a molten pool Wb10 on the base material Ob by melting the base material Ob and the welding rod 100 itself by arc discharge Ar. That is, the welding rod 100 performs arc welding by joining the base material Ob and the welding rod 100 itself by melting them by arc discharge Ar. The welding rod 100 is sent toward the base material as the welding progresses. The welding rod 100 is, for example, A5183, an aluminum alloy in JIS Z 3232. The melting point Tm2 of this welding rod 100 is about 660°C. The melting point Tm3 of the scraper 200 described later is about 3387°C. The heating temperature Tm4 by arc welding is a temperature between the melting point Tm2 and the melting point Tm3. For example, the heating temperature Tm4 by arc welding is about 2500°C. The welding rod 100 is a torch of a welding robot. The welding rod 100 generates an arc discharge Ar by a welding machine provided in the welding robot. The welding rod 100 can be moved by a robot arm of the welding robot during welding. To facilitate understanding of the technology, the welding machine and the robot arm are omitted from FIG. 1. The movement direction of welding is called the direction of arrow AM10 in FIG. 1.

[0014] The scraper 200 separates at least a part of the material constituting the protruding portion Wb11 rising from the molten pool Wb10 above the surface Obs1 of the base material Ob of the bead from the base material Ob while the molten pool Wb10 is melting. This function is achieved by the scraper 200 moving while the molten pool Wb10 is melting. The removed part of the material is called the removed material Wb13. Furthermore, the scraper 200 solidifies the removed material Wb13 flowing on the scraper 200 by the movement of the scraper 200. In addition, the scraper 200 discharges the removed material Wb13 toward the rear Am20, which is opposite to the forward direction Am10, which is the movement direction of the scraper 200. This discharge is a relative operation as viewed from the scraper 200. This discharge will be described in detail later. The moving direction Am10 of the scraper 200 moving in the forward direction Am10 is the same as the moving direction Am10 of the welding rod 100. In Fig. 1, the forward direction Am10 is the +x direction, and the backward direction Am20 is the -x direction.

[0015] FIG. 2 is an explanatory diagram showing the shape of the scraper 200. The scraper 200 is made of a material having a melting point Tm3 higher than the melting point Tm1 of the base metal Ob to be welded and the melting point Tm2 of the welding rod 100. For example, this material is tungsten. The melting point of tungsten is about 3387°C. Therefore, as described above, the melting point Tm3 is about 3387°C. The scraper 200 has a first surface 210s, a second surface 220s, a third surface 230s, and a fourth surface 240s.

[0016] The first surface 210s is a surface of the scraper 200 that faces the base material Ob when removing the bead. In FIG. 2, the direction facing the base material Ob is the -z direction. The second surface 220s and the third surface 230s are surfaces on the opposite side to the first surface 210s. The second surface 220s and the third surface 230s are inclined in the -z direction from the rear Am20 of the scraper 200 toward the front Am10. The tip 270s of the scraper 200 is defined by the connection portion of the first surface 210s and the second surface 220s. The second surface 220s has an edge 221s of the rear Am20 of the scraper 200. The third surface 230s has an edge 231s of the front Am10 of the scraper 200. The edge 221s of the rear Am20 of the second surface 220s is disposed at the upper Am30 and rear Am20 in the posture during the movement of the scraper 200 compared to the edge 231s of the front Am10 of the third surface 230s. As a result, a step 260s due to the difference in height between the second surface 220s and the third surface 230s is formed on the surface opposite to the first surface 210s. The upper Am30 is the +z direction in FIG. 2. The posture during the movement of the scraper 200 is the posture when removing the removed matter Wb13. The posture of the scraper 200 in FIG. 2 represents the posture during the movement of the scraper 200.

[0017] The fourth surface 240s is a pair of surfaces located on both sides of the first surface 210s, the second surface 220s, and the third surface 230s. That is, the fourth surface 240s is a surface located on the left and right sides of the scraper 200, which has a front surface Am10 and a rear surface Am20.

[0018] The support part 300 supports the scraper 200 as shown in FIG. 2. More specifically, the support part 300 supports the scraper 200 from both sides by being connected to the fourth surface 240s of the scraper 200. The connection part with the scraper 200 is called the connection part 310. The end of the support part 300 opposite to the end supporting the scraper 200 is connected to the robot arm of the welding robot. That is, the support part 300 is connected to the scraper 200 and the robot arm. By adopting such an embodiment, the support part 300 moves the scraper 200 in the movement direction Am10 of the welding rod 100 along the movement of the welding by the robot arm. In order to facilitate understanding of the technology, the robot arm is omitted from the illustration in FIG. 2. The support part 300 receives heat due to welding through the scraper 200. Therefore, the support part 300 is made of a material having a melting point Tm3 to prevent melting. For example, the material of the support portion 300 is tungsten.

[0019] Furthermore, the support part 300 can change the angle with respect to the scraper 200. As shown in FIG. 2, the support part 300 can rotate the connection part 310 with the scraper 200 in the direction of the arrow Am40. Therefore, the support part 300 can change the angle R1 of the scraper 200 with respect to the base material Ob by adjusting the angle with respect to the scraper 200. By adopting such an embodiment, as shown in FIG. 1, the support part 300 can adjust the angle R1 at which the tip 270s of the scraper 200 is inserted into the base material Ob. That is, the support part 300 can adjust the force required to separate the removed material Wb13 from the molten pool Wb10. This force is a force perpendicular to the surface Obs1 of the base material Ob. In FIG. 2, this force is a force in the +z direction. In addition, the support part 300 can adjust the distance between the base material Ob and the tip 270s of the scraper 200 by adjusting the angle R1. That is, the support portion 300 can adjust the amount of the removed matter Wb13 to be removed from the raised portion Wb11.

[0020] A2. Removing the weld bead: FIG. 3 is an explanatory diagram showing the removal of a bead by the scraper 200. FIG. 3 shows a cross section of the scraper 200 and the molten pool Wb10 located at the III-III cross section in FIG. 2. The molten pool Wb10 shown in FIG. 3 is in a state in which the removed object Wb13 is melted by the arc welding of the welding rod 100. During this state, the scraper 200 moves in the moving direction Am10 of the welding rod 100, so that the tip 270s of the scraper 200 enters the raised portion Wb11 that is raised above the surface Obs1 of the base material Ob. The scraper 200 separates the removed object Wb13 from the base material Ob. More specifically, the scraper 200 inserts the tip 270s into the raised portion Wb11, thereby placing the removed object Wb13 on the second surface 220s. The second surface 220s of the scraper 200 is inclined in the -z direction from the rear Am20 to the front Am10 of the scraper 200. Therefore, the scraper 200 applies a force in the +z direction to the removed object Wb13 by moving the removed object Wb13 relatively backward Am20 along the second surface 220s inclined in the -z direction. Therefore, the scraper 200 removes the removed object Wb13.

[0021] As described above, the scraper 200 removes the object Wb13 by moving the object Wb13 relatively backward to Am20. This relative movement of the object Wb13 is caused by the scraper 200 moving forward Am10 with respect to the object Wb13. In other words, this movement is not caused by applying a force toward the backward Am20 to the object Wb13. In the following description, unless otherwise specified, the movement of the object Wb13 refers to the relative movement from the scraper 200.

[0022] A3.Solidification of the welding bead: As shown in FIG. 3, the removed material Wb13 flows on the scraper 200 due to the movement of the scraper 200. More specifically, the removed material Wb13 moves along the second surface 220s of the scraper 200. The removed material Wb13 reaches the step 260s by passing over the edge 221s of the rear Am20 of the second surface 220s. The step 260s allows the removed material Wb13 to reach the space between the second surface 220s and the third surface 230s. Air Ai1 flows in this space due to the movement of the scraper 200. Therefore, the scraper 200 and the removed material Wb13 are cooled by the flow of the air Ai1. This cooling is due to heat exchange between the removed material Wb13 and the air Ai1. Furthermore, this cooling is caused by heat exchange between the scraper 200 and the air Ai1, which occurs when the heat of the removed material Wb13 is thermally conducted to the scraper 200. Therefore, the removed material Wb13 is solidified at the rear Am20 of the edge 221s of the rear Am20 of the second surface 220s and at the upper Am30 of the third surface 230s.

[0023] A4. Welding bead discharge: Fig. 4 is an explanatory diagram showing the discharge of the removed material Wb13 by the scraper 200. Fig. 4 shows the state of the scraper 200 as viewed from the +z direction in Fig. 3. As the scraper 200 moves, the removed material Wb13 moves along the second surface 220s toward the rear Am20, which is opposite to the forward Am10, which is the moving direction of the scraper 200. Furthermore, the removed material Wb13 moves along the third surface 230s, and is discharged from the rear Am20 of the scraper 200.

[0024] A5. Weld bead removal process steps: Fig. 5 is a flow chart showing steps of a method for removing a weld bead. In step S100 of Fig. 5, a user prepares a scraper 200 made of a material having a melting point Tm3 higher than the melting point Tm1 of the base metal Ob to be welded and the melting point Tm2 of the welding rod 100. That is, the scraper 200 is attached to the device 10 as shown in Fig. 1, and becomes usable while the molten pool Wb10 is melting.

[0025] 5, the control unit of the welding robot in the apparatus 10 heats the base material Ob and the welding rod 100 to a temperature Tm4 lower than the melting point Tm3 of the scraper 200, thereby generating a molten pool Wb10 in which the base material Ob and the welding rod 100 are melted together. That is, the welding rod 100 starts welding the processing target of the base material Ob.

[0026] Fig. 6 is an explanatory diagram showing the generation of a molten pool Wb10 by arc welding. The welding rod 100 melts the base metal Ob and the welding rod 100 by performing an arc discharge Ar on the base metal Ob. Thus, a weld pool Wb10 is generated on the base metal Ob. To facilitate understanding of the technique, the scraper 200 and the support part 300 are omitted from Fig. 6.

[0027] 5, while the molten pool Wb10 is melting, the scraper 200 separates the removed material Wb13 from the base material Ob by the scraper 200. This step is performed by moving the scraper 200 from the molten pool Wb10 to a protruding portion Wb11 that protrudes higher than the surface Obs1 of the base material Ob of the bead.

[0028] 7 is an explanatory diagram showing the scraper 200 moving toward the molten pool Wb10. The scraper 200 moves toward the molten pool Wb10 while aligning its tip 270s along the base material Ob. Then, the scraper 200 removes the removal material Wb13, which will become a bead, from the molten pool Wb10, as shown in FIG.

[0029] 5, the scraper 200 solidifies the removed material Wb13 flowing on the scraper 200 by the movement of the scraper 200. This solidification is performed behind the edge 221s of the rear Am20 of the second surface 220s and above the third surface 230s Am30, as shown in FIG.

[0030] In step S140 of Fig. 5, the scraper 200 discharges the removed material Wb13 toward the rear Am20, which is opposite to the forward Am10, which is the moving direction of the scraper 200. This discharge is performed by moving the removed material Wb13 along the second surface 220s of the scraper 200, which is opposite to the first surface 210s facing the base material Ob, as shown in Fig. 4. Note that, in order to facilitate understanding of the technology, steps S120 to S140 have been described individually, but in actual welding, steps S120 to S140 are performed in parallel on Wb10 at different parts of the base material.

[0031] In step S150 of FIG. 5, the control unit of the welding robot checks the remaining processing target. This welding robot is a welding robot equipped with a welding rod 100. If there is a remaining processing target, the control unit of the welding robot advances the process to step S120 to continue welding. If there is no remaining processing target, the control unit of the welding robot ends welding. The scraper 200 advances in the movement direction Am10 of the welding rod 100 while the molten pool Wb10 is melting. Thus, the scraper 200 moves until there is no more of the molten pool Wb10 that has not yet been removed of the removal material Wb13. Therefore, the removal of the bead ends when the molten pool Wb10 disappears due to the end of welding.

[0032] FIG. 8 is an explanatory diagram showing the end of welding by the welding rod 100. The control unit of the welding robot ends the welding by stopping the arc discharge Ar. Thus, the generation of a new molten pool Wb10 stops. The scraper 200 continues to move in the movement direction Am10 of the welding rod 100 while the molten pool Wb10 is melting. Thus, the scraper 200 continues to move to the point where the welding rod 100 stopped welding, thereby removing the removed material Wb13 from the remaining molten pool Wb10. The scraper 200 finishes removing the bead because no new molten pool Wb10 is generated.

[0033] 9 is an explanatory diagram showing the base material Ob after the bead has been removed. After the bead has been removed by the scraper 200, the base material Ob is left with a molten pool Wb12 from which the removed material Wb13 has been removed from the molten pool Wb10. Therefore, after the molten pool Wb12 solidifies, the base material Ob is in a state without a protruding bead.

[0034] By adopting such an embodiment, the bead removal method of the present disclosure can shorten the cycle time compared to an embodiment in which the raised portion Wb11 is removed after the bead cools. Furthermore, the bead removal method of the present disclosure can remove the removed material Wb13 from the base material Ob without rotating the cutting tool. Therefore, the bead removal method of the present disclosure can remove the removed material Wb13 that has left the base material Ob without scattering. Therefore, the bead removal method of the present disclosure makes it easier to collect the removed material Wb13 by discharging it to the rear Am20 of the scraper 200 compared to the case in which the removed material Wb13 scatters around. Furthermore, the bead removal method of the present disclosure can solidify the removed material Wb13 in a molten state on the scraper. That is, the bead removal method of the present disclosure can collect the removed material Wb13 at a lower temperature compared to the case in which the removed material Wb13 in a molten state is collected. Therefore, the bead removal method of the present disclosure can collect the removed material Wb13 easily without temperature restrictions compared to the case in which the removed material Wb13 in a molten state is collected. Furthermore, the bead removal method of the present disclosure removes the removed matter Wb13 at a higher temperature than when the solidified removed matter Wb13 is collected, so that welding between the scraper 200 and the removed matter Wb13 is unlikely to occur. In other words, the bead removal method of the present disclosure can reduce the work required to prevent welding.

[0035] B. Second embodiment: FIG. 10 is an explanatory diagram showing the configuration of the device 10a including a scraper 200a equipped with a collecting section 280. In the second embodiment, the scraper 200a includes a collecting section 280 for collecting the removed material Wb13 at the rear Am20 of the second surface 220s. In the scraper 200a, the surface opposite to the first surface 210s is composed only of the second surface 220s. The second surface 220s will be described in detail later. Other points of the device 10a are the same as those of the device 10 of the first embodiment.

[0036] The collecting unit 280 collects the removed matter Wb13 removed by the scraper 200a. For example, the collecting unit 280 is a suction machine using a vacuum pump. The collecting unit 280 collects the removed matter Wb13 by sucking it from the rear Am20 of the second surface 220s. Furthermore, the collecting unit 280 cools the removed matter Wb13 by generating a flow of air Ai2 by suction. The collecting unit 280 can connect a nozzle portion, which is an inlet for suction, to the scraper 200a. For example, the collecting unit 280 is connected to the connection portion 310 of the scraper 200a and the support portion 300. To facilitate understanding of the technology, only the nozzle portion of the collecting unit 280 is illustrated in FIG. 10. The scraper 200a is composed of only the second surface 220s on the surface opposite to the first surface 210s. Therefore, the recovery section 280 recovers the removed matter Wb13 from the rear Am20 of the second surface 220s. In addition, the fourth surface 240s is positioned as a pair of surfaces located on both sides of the first surface 210s and the second surface 220s.

[0037] 11 is an explanatory diagram showing collection of the removed material Wb13 by the collection unit 280. The collection unit 280 performs suction from the rear Am20 of the second surface 220s while removing the beads. The removed material Wb13 discharged to the rear Am20 of the second surface 220s is collected by being sucked into the collection unit 280. The movement of the removed material Wb13 by the suction of the collection unit 280 is not a relative movement from the scraper 200. The removed material Wb13 receives a force toward the rear Am20 by the suction of the collection unit 280, and moves to the collection unit 280.

[0038] Fig. 12 is a flow chart showing the process of collecting the removed material Wb13 by the collecting unit 280. Step S141a is a process following step S140 in Fig. 5. The collecting unit 280 performs suction from the rear Am20 of the scraper 200a while removing the bead. Thus, the collecting unit 280 collects the removed material Wb13 discharged behind the scraper 200a. When the process proceeds to step S150 in Fig. 5 and welding is completed, the collecting unit 280 ends this process because the removed material Wb13 is no longer discharged.

[0039] By adopting such an embodiment, the method of removing the beads by the apparatus 10a can collect the removed matter Wb13 by the collection unit 280 provided in the scraper 200a, thereby reducing the risk that the removed matter Wb13 will fall onto the base material Ob.

[0040] C. Third embodiment: 13 is an explanatory diagram showing the configuration of an apparatus 10b including a scraper 200b having a protruding portion 290. In the third embodiment, the scraper 200b has a protruding portion 290 protruding from the first surface 210s. Other points of the apparatus 10b are the same as those of the apparatus 10 of the first embodiment.

[0041] FIG. 14 is an explanatory diagram showing the protrusion 290 of the scraper 200b. The protrusion 290 smooths out the unevenness of the surface of the molten pool Wb12 from which the removed material Wb13 has left. This is performed by bringing the tip 291s of the protrusion 290 into contact with the surface Obs1 of the base material Ob. The protrusion 290 protruding from the first surface 210s is formed from one of the two fourth surfaces 240s toward the other fourth surface 240s. That is, the protrusion 290 is formed so as to intersect with the moving direction Am10 of the scraper 200. Furthermore, the tip 291s of the protrusion 290 is formed so as to move from the front Am10 toward the rear Am20 when the scraper 200 moves. More specifically, in a cross section perpendicular to the y-axis, the cross-sectional shape of the protrusion 290 is triangular. Therefore, when the scraper 200 moves, the fifth surface 292s of the protrusion 290 facing the front Am10 is inclined in the +z direction from the rear Am20 toward the front Am10. In addition, the tip 291s is formed with a constant height h1 from the first surface 210s to the tip 291s. The height h1 is designed to reach the surface Obs1 of the base material Ob when removing the bead.

[0042] FIG. 15 is an explanatory diagram showing the relationship between the protrusion 290 and the molten pool Wb10. FIG. 15 shows a cross section of the scraper 200b and the molten pool Wb10 located at the XV-XV cross section in FIG. 14. To facilitate understanding of the technology, the step 260s is omitted. FIG. 15 shows the molten material Wb121 on the surface of the molten pool Wb12. The molten material Wb121 will be described later. When the scraper 200 moves, the tip 291s of the protrusion 290 is brought into contact with the surface Obs1 of the base material Ob. Therefore, the height h1 from the first surface 210s to the tip 291s is designed to be the height to the surface Obs1 of the base material Ob at this time.

[0043] Fig. 16 is a flowchart showing the process of smoothing the molten pool Wb12 by the protruding portion 290. Step S141b in Fig. 16 is a process following step S140 in Fig. 5. As shown in Fig. 15, the protruding portion 290 smoothes out the irregularities on the surface of the molten pool Wb12 from which the removed material Wb13 has been removed from the raised portion Wb11. These irregularities are the molten material Wb121.

[0044] 5, the scraper 200 applies a force in the +z direction to the material Wb13 to be removed, thereby removing the material Wb13. Therefore, the scraper 200 does not apply a force in the -z direction to the raised portion Wb11. Therefore, if a gap occurs between the tip 270s and the surface Obs1 of the base material Ob, the molten material Wb121 that has not been removed remains on the surface of the molten pool Wb12. This gap occurs when the tip 270s moves away from the surface Obs1 due to the shaking of the scraper 200 when it moves, or due to resistance from the molten material when it is removed.

[0045] In step S141b in FIG. 16, the scraper 200 moves, and the protrusion 290 reaches the molten material Wb121 as shown in FIG. 15. The protrusion 290 prevents the molten material Wb121 from moving from the protrusion 290 to the rear Am20 by the tip 291s. Therefore, the protrusion 290 moves the molten material Wb121 along the fifth surface 292s. The fifth surface 292s is inclined in the +z direction from the rear Am20 to the front Am10 when the scraper 200 moves. Therefore, the protrusion 290 applies a force in the -z direction to the molten material Wb121 in contact with the fifth surface 292s by moving to the front Am10. That is, the protrusion 290 applies pressure to the molten material Wb121 to form a molten pool Wb14 that smooths out the unevenness of the molten pool Wb12. The process proceeds to step S150 in FIG. 5, and when welding is completed, the process ends in order to finish leveling the remaining molten pool Wb12.

[0046] By adopting such an embodiment, the bead removal method using the device 10b can reduce the roughness of the bead surface after the bead is removed.

[0047] D. Fourth embodiment: FIG. 17 is an explanatory diagram showing a scraper 200c having a cooling path 241. In FIG. 17, the support portion 300 is omitted from illustration in order to facilitate understanding of the technology. In the above embodiment, the scraper 200 solidifies the removed material Wb13 by flowing the air Ai1 through the step 260s. However, the solidification of the removed material Wb13 is not necessarily limited to this form. The solidification of the removed material Wb13 may be in a form other than the step 260s, or may be achieved by providing both the step 260s and another form. For example, a fourth embodiment using the scraper 200c shown in FIG. 17 is exemplified. The scraper 200c has a through hole connecting the two fourth surfaces 240s. This through hole is called the cooling path 241. The scraper 200c does not have the step 260s. Therefore, the surface opposite to the first surface 210s is composed of only the second surface 220s. The other points of the device 10c constituted by the scraper 200c are the same as those of the device 10 of the first embodiment.

[0048] The cooling path 241 cools the scraper 200 with cooling water. More specifically, the cooling path 241 injects the cooling water from one of the two openings of the through hole toward the other, thereby causing the cooling water to flow inside the cooling path 241. For example, in FIG. 17, the cooling water passes through the cooling path 241 by flowing in the direction of the arrow Am50, which is the +y direction. The cooling path 241 cools the scraper 200 by exchanging heat between the cooling water and the scraper 200. That is, the removed material Wb13 is solidified by being cooled through the scraper 200.

[0049] E. Fifth embodiment: FIG. 18 is an explanatory diagram showing the device configuration of the device 10d including the scraper 200d having the collecting section 280a. In FIG. 18, the support section 300 is omitted from the illustration in order to facilitate understanding of the technology. In the above-mentioned second embodiment, the scraper 200a collects the removed matter Wb13 discharged from the rear Am20 of the second surface 220s by the collecting section 280. However, the collection of the removed matter Wb13 is not necessarily limited to this form. For example, the fifth embodiment is exemplified as the collecting section 280a shown in FIG. 18. The collecting section 280a is configured by bundling a plurality of thread-like members. The collecting section 280a collects the removed matter Wb13 in a molten state. Other points of the device 10d including the scraper 200d are the same as the device 10a of the second embodiment.

[0050] The collecting unit 280a collects the molten removed material Wb13 by capillary action. More specifically, the collecting unit 280a brings a bundle of multiple tubes into contact with the molten removed material Wb13, and adsorbs the removed material Wb13 that has entered between the tubes by capillary action. The collecting unit 280a is made of a material having a melting point Tm3. For example, the collecting unit 280a is a bundle of tungsten wires. The thickness and number of the tungsten wires are determined experimentally using the molten removed material Wb13. The scraper 200d does not have a step 260s, so it causes the molten removed material Wb13 to flow along the second surface 220s. As shown in FIG. 18, the collecting unit 280a is arranged on the second surface 220s in the flow path of the removed material Wb13. In this embodiment, the collection unit 280a comes into contact with the removed matter Wb13 flowing on the second surface 220s of the scraper 200d, and collects it by adsorbing it due to capillary action.

[0051] F. Sixth embodiment: FIG. 19 is an explanatory diagram showing the configuration of the device 10e including the scraper 200e having the collecting section 280b. In FIG. 19, the support section 300 is omitted from the illustration in order to facilitate understanding of the technology. FIG. 19 shows a sixth embodiment for collecting the removed material Wb13. The collecting section 280b is a container for storing the removed material Wb13. The scraper 200e does not have a step 260s because the collecting section 280b can also collect the removed material Wb13 in a molten state. Therefore, the surface opposite to the first surface 210s is composed only of the second surface 220s. Other points of the device 10e including the scraper 200e are the same as the device 10a of the second embodiment.

[0052] The collecting unit 280b collects the removed matter Wb13 removed by the scraper 200e. More specifically, the collecting unit 280b can store the removed matter Wb13 inside the collecting unit 280b. The collecting unit 280b is made of a material having a melting point Tm3. For example, the collecting unit 280b is a container made of tungsten. The collecting unit 280b is disposed behind the scraper 200e of the removed matter Wb13, Am20. The collecting unit 280b is connected to the rear of the second surface 220s so as to be connected to the flow path of the removed matter Wb13. By adopting such an embodiment, the collecting unit 280b can collect the removed matter Wb13 discharged from the second surface 220s.

[0053] G. Seventh embodiment: FIG. 20 is an explanatory diagram showing the device configuration of the device 10f composed of the scraper 200f. The scraper 200f has a filament shape. For example, the scraper 200f is a tungsten wire. Therefore, the melting point Tm3 of the scraper 200f is about 3387°C because the material is tungsten. Furthermore, the diameter d1 of this tungsten wire is smaller than the height h2 from the surface Obs1 of the base material Ob at the protruding portion Wb11. In FIG. 20, the diameter d1 is illustrated as being larger than the height h2 to facilitate understanding of the scraper 200f. The scraper 200f is supported by connecting both ends of the filament-shaped body to the connection portion 310 of the support portion 300 in the first embodiment. Other points of the device 10f composed of the scraper 200f are the same as those of the device 10 of the second embodiment.

[0054] By adopting such an embodiment, the scraper 200f can insert its main body between the removed object Wb13 and the surface Obs1. Therefore, the scraper 200f separates the removed object Wb13 from the base material Ob while the molten pool Wb10 is melting. Furthermore, the scraper 200f can discharge the removed object Wb13 that has exceeded its main body to the rear. Therefore, the seventh embodiment can remove the removed object Wb13 that has separated from the base material Ob without scattering it. Therefore, the seventh embodiment makes it easier to collect the removed object Wb13 by discharging it to the rear Am20 of the scraper 200f, compared to when the removed object Wb13 scatters around.

[0055] H. Other embodiments: In the above embodiment, the welding that generates the molten pool Wb10 is consumable electrode welding. However, the welding may be non-consumable electrode welding. For example, it may be laser welding. In the case of laser welding, the molten pool Wb10 is generated by a filler rod and a laser beam from a laser scanner. More specifically, the laser scanner irradiates the base material Ob and the filler rod, which has a melting point Tm2, ​​with laser beams to heat the base material Ob and the filler rod to a temperature Tm4. Thus, the laser scanner generates a molten pool Wb10 in which the base material Ob and the filler rod are melted together. The filler rod is, for example, an aluminum alloy A5183 in JIS Z 3232. The filler rod is moved along the movement of the laser beam by a robot arm. The scraper 200 realizes bead removal in the same manner as the device 10 by connecting the support 300 to the robot arm.

[0056] In the above embodiment, the melting point Tm1 of the base material Ob and the melting point Tm2 of the welding rod 100 are about 660°C because aluminum is used as the material. The melting point Tm3 of the scraper 200 is about 3387°C because tungsten is used as the material. The temperature Tm4 of the heating by arc welding is about 2500°C. However, each temperature is not limited to this condition. The melting point Tm3 of the scraper 200 may be higher than the melting point Tm1 of the base material Ob and the melting point Tm2 of the welding rod 100. The temperature Tm4 of the heating by arc welding may be lower than the melting point Tm3 of the scraper 200. For example, the following configuration can be exemplified. The base material Ob is mild steel with a melting point Tm1 of about 1500°C. The welding rod 100 is a lime-titania type welding rod according to JIS Z3211 E4303. The melting point Tm2 of this welding rod 100 is about 1500° C. The scraper 200 is made of ceramics with a melting point Tm3 of about 2700° C. The heating temperature Tm4 by arc welding is about 2000° C.

[0057] In the above embodiment, the protrusion 290 is a component of the scraper 200b of the third embodiment. However, the protrusion 290 may be included in the components of the scraper in other embodiments other than the seventh embodiment. For example, the scraper 200a of the second embodiment may include both the collection portion 280 and the protrusion 290.

[0058] In the second embodiment, the scraper 200a including the collection portion 280 may include the step 260s in the first embodiment.

[0059] In the third embodiment, the scraper 200b having the protrusion 290 may be provided with a collecting section that collects the removed matter Wb13 in other embodiments. For example, the scraper 200b may be provided with the collecting section 280 in the second embodiment.

[0060] In the above-described fourth embodiment, the scraper 200c including the cooling passage 241 may include a collecting section that collects the removed matter Wb13 in other embodiments. For example, the scraper 200c may include the collecting section 280 in the second embodiment.

[0061] In the sixth embodiment, the scraper 200e including the collecting portion 280b may include the step 260s in the other embodiments. In this case, the collecting portion 280b is connected to the rear of the third surface 230s so as to be connected to the flow path of the removed matter Wb13.

[0062] In the seventh embodiment, the scraper 200f, which is a thread-like main body, may include the collection unit 280 of the second embodiment or the collection unit 280b of the sixth embodiment. In this case, the scraper 200f can collect the removed material Wb13 by connecting the collection unit 280 or the collection unit 280b to the connection unit 310.

[0063] The above embodiment can be used for various manufacturing processes that require removal of weld beads. As an example, the above embodiment can be used for manufacturing batteries. More specifically, the above embodiment can be used for manufacturing battery cases to prevent interference between parts due to beads.

[0064] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0065] 10...apparatus, 10a...apparatus, 10b...apparatus, 10c...apparatus, 10d...apparatus, 10e...apparatus, 10f...apparatus, 100...welding rod, 200...scraper, 200a...scraper, 200b...scraper, 200c...scraper, 200d...scraper, 200e...scraper, 200f...scraper, 210s...first surface, 220s...second surface, 221s...edge, 230s...third surface, 231s...edge, 240s...fourth surface, 241...cooling path, 260s...step, 270s...tip, 280...recovery section, 280a...recovery section, 280b ...recovery section, 290...protruding section, 291s...tip, 292s...fifth surface, 300...support section, 310...connection section, Ai1...air, Ai2...air, Am10...front, Am20...rear, Am30...upper, Am40...rotation direction, Am50...flow path direction, Ar...arc discharge, Ob...base material, Obs1...surface, R1...angle, Tm1...melting point, Tm2...melting point, Tm3...melting point, Tm4...temperature, Wb10...molten pool, Wb11...raised area, Wb12...molten pool, Wb121...molten material, Wb13...removed material, Wb14...molten pool, d1...diameter, h1...height, h2...height

Claims

1. 1. A method for removing a weld bead, comprising the steps of: (a) preparing a scraper made of a material having a melting point higher than the melting point of the base material to be welded and the melting point of the welding rod; (b) heating the base material and the welding rod at a temperature lower than the melting point of the scraper to generate a molten pool in which the base material and the welding rod are fused together; (c) while the molten pool is molten, moving the scraper from the molten pool to a protruding portion of the bead that is higher than the surface of the base metal, and removing at least a portion of the material constituting the protruding portion from the base metal by the scraper; (d) moving the at least part of the material along a second surface of the scraper opposite to the first surface facing the base material, thereby discharging the at least part of the material toward the rear, which is opposite to the forward movement direction of the scraper in step (c); The scraper further includes a third surface disposed opposite the first surface, The rear edge of the second surface is disposed above and rearward of the front edge of the third surface in the position during the movement of the scraper, The step (d) causing the movement of the scraper to solidify at least a portion of the material flowing over the scraper behind the trailing edge of the second surface and above the third surface.

2. 1. A method for removing a weld bead, comprising the steps of: (a) preparing a scraper made of a material having a melting point higher than the melting point of the base material to be welded and the melting point of the welding rod; (b) heating the base material and the welding rod at a temperature lower than the melting point of the scraper to generate a molten pool in which the base material and the welding rod are fused together; (c) while the molten pool is molten, moving the scraper from the molten pool to a protruding portion of the bead that is higher than the surface of the base metal, and removing at least a portion of the material constituting the protruding portion from the base metal by the scraper; (d) moving the at least part of the material along a second surface of the scraper opposite to the first surface facing the base material, thereby discharging the at least part of the material toward the rear, which is opposite to the forward movement direction of the scraper in step (c); The scraper includes a protrusion protruding from the first surface, The step (c) of the method for removing a weld bead includes a step of abutting the tip of the protrusion against the surface of the base material and smoothing out any irregularities on the surface of the molten pool from which the material has been separated.

3. 3. The method for removing a weld bead according to claim 2, comprising the steps of: The scraper includes a collection portion at the rear of the second surface for collecting material removed by the scraper, After the step (d), (f) A method for removing a weld bead, comprising the step of recovering the at least a portion of the discharged removed material by the recovery section.

Images