JP6259341B2 - Joining device - Google Patents

Description

  The present invention relates to a joining device for joining two metal members.

  An electric circuit consists of a power source that supplies electricity and electric parts that perform a certain function using electricity. Wiring connection or connection work is always required to build an electric circuit. I need it. In general, a large amount of arc welding using an electric discharge phenomenon (arc discharge) is often used for spot joining of discrete terminal members, particularly spot joining of copper bus bars. The arc welding method is a joining method in which the base material is welded using the heat of the arc generated in the air between the electrode and the base material, and the electrode is consumed (melted) by the arc heat (for example, MIG). There are two types: non-consumable electrode type (for example, TIG welding method) that does not wear out.

JP 2011-62723 A

  As described above, the arc welding method is a joining method in which the base metal is welded using the heat of the arc generated in the air between the electrode and the base material. Is also big. In particular, a bus bar, which is an elongated bar-like or plate-like conductor metal used to supply power to a large number of integrated circuits on a circuit board, is mounted on the circuit board and bonded in many places. In view of this, the magnitude of power consumption and the thermal effect on the surroundings when arc welding is used for spot joining between bus bars is a serious problem.

  Also, pure copper is preferably used as the material for the bus bar. Pure copper is roughly classified into two types: oxygen-free copper having a purity of 99.95% or more and tough pitch copper having a purity of 99.9% or less. Tough pitch copper is far more advantageous in terms of cost. However, when arc welding a tough pitch copper bus bar, blow holes are likely to occur. That is, in the case of tough pitch copper, hydrogen reacts with oxygen remaining inside the copper at a high temperature in an arc atmosphere to generate water vapor, and this water vapor becomes a blowhole without being diffused and released to the outside.

  Furthermore, it is a great disadvantage in terms of yield that a metal joint once formed by welding cannot be recovered (recovered) or re-used. For example, if there are 10 bus bar joints or joints on one circuit board and there is poor welding at one of them, even if the welding results at all the remaining nine locations are good, The entire electronic circuit on the circuit board becomes a defective product.

  The present invention solves the problems of the prior art as described above, and uses two metal members while using an arc, has low power consumption without affecting the surroundings, and is stable with high yield. Provided is a joining device capable of joining in a finished state.

The joining device of the present invention is a joining device for joining the joined parts of the first and second metal members, and has a non-consumable torch electrode, and the torch electrode and the joined part An arc generating portion that generates an arc that does not melt the welded portion at all or almost in between, and a wire-like or rod-like filler material is fed toward the arc, and after supplying a predetermined amount of the filler material, A filler material supply unit for retracting the additive material from the arc, and a filler material supply amount for measuring the amount of the filler material supplied to the arc by the filler material supply unit in one joining operation. have a measurement portion, the filler material supply amount measuring unit, an encoder for sequential measuring movement amount when the filler in the filler material feeder is advanced or retracted, once Before and after the start of the joining operation, And a first encoder output obtained from the encoder when the tip of the filler material arrives at the wire start position before the start of the joining operation. The amount of the filler material supplied to the arc from the value and the second encoder output value obtained from the encoder when the tip of the filler material arrives at the wire start position after completion of the joining operation And a calculation unit for obtaining the measured value of the filler material, and measuring the supply amount of the filler material with the tip of the filler material as a mark.

  In the above apparatus configuration, an arc is generated between the torch electrode and the bonded portion of both metal members, and this arc is used not only for melting the welded portion (arc welding) but for melting the meltable material. In this type of spot joining, in which the meltable material is melted and solidified by the heat of the arc to join the joined parts, the supply amount of the wire-like filler material given to the arc is melted on the joined parts. It is proportional to the amount of filler metal and, in turn, proportional to the amount of alloy formed by solidification of the molten filler material, and greatly affects the quality of brazing (joining strength, finish, etc.). In the joining apparatus of the present invention, the supply amount of the wire-like filler material given to the arc in the spot welding is measured by the filler material supply amount measuring unit, so that the user can present the measured value of the filler material supply amount presented. Can be effectively used as a barometer (quality control information) for assuring the quality of the spot junction.

  Further, in a preferred embodiment of the present invention, a gap between a position where the torch electrode of the bonded portion is in contact or a position between the tip of the torch electrode and the position of the torch electrode of the bonded portion is in contact. The filler material is supplied. As a result, the filler metal can be introduced into the arc column or core of the arc without removing the filler material at all times, and the melt material can be melted most efficiently and reliably, and the processing quality of spot welding by brazing is improved. It can be further enhanced.

  In another preferred embodiment, the location where the torch electrode of the bonded portion should contact is set at or near the gap of the bonded portion. As a result, an arc can be generated in or near the gap of the welded portion, and the filler material can be efficiently diffused in the gap.

  In another preferred embodiment, the filler metal is supplied into the arc after a predetermined time (preferably 0.1 to 0.5 seconds) after the arc is generated. Thereby, the influence which a base material receives can be decreased and wettability can be improved.

According to the joining apparatus of the present invention , having the above-described configuration, a stable finish with low power consumption and high yield without affecting the surroundings while using two metal members using an arc. Can be joined.

It is a figure which shows the whole structure of the joining apparatus in one Embodiment of this invention. It is a perspective view which shows the to-be-joined part of the base material in embodiment. It is a flowchart which shows the procedure of the brazing method in embodiment. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the torch raising / lowering operation | movement in the said joining apparatus. It is a figure which shows one step of the melt material supply operation | movement and electricity supply operation | movement in the said joining apparatus. It is a figure which shows one step of the melt material supply operation | movement and electricity supply operation | movement in the said joining apparatus. It is a figure which shows one step of the melt material supply operation | movement and electricity supply operation | movement in the said joining apparatus. It is a figure which shows one step of the melt material supply operation | movement and electricity supply operation | movement in the said joining apparatus. It is a figure which shows one step of the melt material supply operation | movement and electricity supply operation | movement in the said joining apparatus. It is a side view which shows the structure of the melt material supply apparatus and the melt material supply amount measurement part in the said joining apparatus. It is a top view which shows the structure of the principal part of the filler material feeding head in the said joining apparatus. It is a flowchart figure which shows the control or calculation procedure of the control part in melt material front-end | tip position adjustment. It is a figure which shows typically each step of melt material front-end | tip position adjustment. It is a figure which shows one modification around the rectilinear drive member in embodiment. It is a figure which shows another modification around the rectilinear drive member in embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, the whole structure of the joining apparatus in one Embodiment of this invention is shown. This bonding apparatus has a stationary apparatus configuration that can suitably cope with spot bonding, particularly worship bonding (butt bonding), and is a unit-type apparatus that incorporates a DC power supply circuit, a control circuit, various drive circuits, and the like. Brazing (brazing or brazing or using an arc) on the main body 10 and a material to be joined (base material) on an electric component support (for example, a circuit board or a circuit assembly) S under supply and control of utility from the apparatus main body 10. And a gas cylinder 14 which is a supply source of a shielding gas, for example, argon gas.

  The joining head 12 is provided with a movable stage 18 and a torch stand 20 on a plate-like base 16, and a torch stand 20 mounted on the torch stand 20 so as to be movable up and down, and a support body independent of the torch stand 20 and the movable stage 18 ( The filler material feeding device 24 is held in a predetermined position and orientation (not shown).

  The movable stage 18 includes an XY stage 26 for moving the electric component support S in the XY direction in the horizontal plane, and a θ stage 27 for moving the electric component support S in the azimuth direction (θ direction) in the horizontal plane. And have. On the other hand, the torch stand 20 is provided with an elevating tower 30 having a built-in elevating drive unit (not shown) using, for example, a servo motor as a drive source on a fixed base 28. A straight drive member 34 is coupled to the lift drive unit of the lift tower 30 via a lift support shaft 32, and the torch 22 is attached to the straight drive member 34 so as to be integrally movable in the vertical direction. A mechanism for connecting the rectilinear drive member 34 and the torch 22 will be described in detail later.

  The torch 22 is fixed in the horizontal direction. The XY stage 26 and the θ stage 27 perform a movement operation in the XY direction and a movement (rotation) operation in the θ direction under the control signal sent from the apparatus main body 10 via the electric cable 36, respectively. It is possible to position the bonded portion WJ of the bonded material to be brazed on the mounted electrical component support S directly below the torch 22.

  The torch 22 is supplied with the power for brazing and the shielding gas SG in the present embodiment from the apparatus main body 10 via the hose 38 with a built-in electric cable, and is a cylindrical torch made of an insulator such as resin. It has a body 40 and a cylindrical or conical torch nozzle 42 attached to the lower end (tip) of the torch body 40, and a pencil-shaped torch electrode (tungsten electrode rod) 44 is placed in the torch body 40 and the torch nozzle 42. It is detachably mounted, and the lower end (tip) of the torch electrode 44 protrudes slightly (usually 2 to 3 mm) from the lower end (tip) of the torch nozzle 42.

  The apparatus main body 10 is provided with a display 46, operation buttons 48, a power switch 50 and the like on the front face of the unit in a touch panel form, and external connection terminals or connectors 52 are provided on the side face or back face of the unit. The shield gas SG sent from the gas cylinder 14 to the hose 15 is supplied to the torch 22 via the apparatus main body 10 and the hose 38.

In FIG. 2, an example of the to-be-joined material (base material) which can apply the spot joining in this embodiment is shown. In the example shown in the figure, for example, two elongated rod-like or plate-like metal members made of copper, for example, bus bars W ₁ and W ₂ are used as base materials, and upper end surfaces of both metal members W ₁ and W ₂ ( The top surfaces of the top surfaces are substantially flush with each other, and the upper ends of the top surfaces are integrated together. The upper ends of the metal members W ₁ and W ₂ combined together form a joined portion WJ. The other end (not shown) of each metal member W ₁ , W ₂ communicates with an electrical component (not shown) mounted on the electrical component support S, for example. Alternatively, one terminal member W ₁ is mounted on an electrical component support S, and the other end of the other terminal member W ₂ is mounted on another electrical component support (not shown). (Not shown).

Further, as shown in FIG. 2, a pair of contacts (contacts) C ₁ and C ₂ are detachably contacted with both metal members W ₁ and W ₂ from both the left and right sides, preferably avoiding the joined portion WJ. These contacts C ₁ and C ₂ are electrically connected to the positive electrode of the power supply circuit 76 (FIGS. 5A to 5E) in the apparatus main body 10 via the electric cable 56.

  The filler material feeding device 24 operates under a control signal sent from the device body 10 via the electric cable 62 so as to poke the wire-like filler material M against the supply destination (arc). It is configured to be sent out and retracted instantly. The filler material feeding device 24 is provided with a filler material supply amount measuring unit 110 that measures the amount of the wire-like filler material M supplied to the supply destination by one joining operation using an encoder. Yes. Detailed configurations and operations of the filler material feeding device 24 and the filler material supply amount measuring unit 110 will be described later.

  In this embodiment, as will be described later, the wire-like filler material M can always be introduced and melted into the arc column or core of the arc AC without removing the wire-like filler material M. It can be considered that the entire amount of the wire-like filler metal M sent out toward the joint portion WJ is effectively used for brazing.

As an example, when the base metal members W ₁ and W ₂ are each a bus bar made of a tough pitch copper square bar having a cross section of 2 mm × 2 mm, a tungsten bar having a diameter (φ) of 2.4 mm, for example, is used for the torch electrode 44. For the wire filler metal M, for example, a phosphor copper brazing wire having a diameter (φ) of 0.8 mm is used. In a normal base material, there is always some gap (for example, about 0.1 mm) at the contact interface between the metal members W ₁ and W ₂ . In the brazing of the welded portion WJ in this embodiment, as will be described later, the filler material (phosphorous copper braze) melted by arc heat in the vicinity of the top surface of the welded portion WJ is diffused by wetting, and the gap g Soaks in.

  Next, a mechanism for connecting the straight drive member 34 and the torch 22 in the joining apparatus of this embodiment will be described with reference to FIGS. 4A to 4F. As shown in the drawing, the torch body 40 is passed through the through-hole 34 a of the plate-like rectilinear drive member 34, and the hook-like or flange-like connecting member 66 fixed to the upper part or middle part of the torch body 40 is the rectilinear drive member 34. The torch body 40 is coupled to the rectilinear drive member 34 such that the torch body 40 is placed on the upper surface of the straight drive member 34.

In the torch elevating mechanism having such a configuration, while the lower end of the torch electrode 44 is floating in the air (FIG. 4A), when the elevating tower 30 lowers the rectilinear drive member 34, the connecting member 66 is the upper surface of the rectilinear drive member 34. The torch 22 is moved downward together with the rectilinear drive member 34 in the state of being placed on (Fig. 4B). Then, when the lower end of the torch electrode 44 comes into contact with the upper surface of the joined portion WJ of the base material (W ₁ , W ₂ ) (FIG. 4C) and the rectilinear drive member 34 is further lowered, the connecting portion 66 of the torch body 40 moves straight. Separated from the drive member 34 (FIG. 4D), the torch body 40 stands on the joined portion WJ independently of the rectilinear drive member 34 (FIG. 4D). At this time, the weight of the torch 22 is applied to the bonded portion WJ.

Further, when the straight drive member 34 is moved up to the original height position from the state where the lower end of the torch electrode 44 is in contact with the bonded portion WJ of the base material (W ₁ , W ₂ ) (FIG. 4E), In the middle, the connecting member 66 of the torch body 40 is placed on the rectilinear drive member 34, and the torch body 40 is also moved upward together with the rectilinear drive member 34 (FIG. 4F).

  In this embodiment, the sensor 70 for detecting the connection or separation state between the connection member 66 of the torch body 40 and the rectilinear drive member 34 is provided. The illustrated sensor 70 is composed of a vertical linear scale, and a scale portion 72 extending in the vertical direction attached to the side surface of the connecting member 66, and the scale portion 72 according to the relative height position of the rectilinear drive member 34. And a scale reading unit 74 attached to the linear drive member 34 so as to be optically read at a level. The scale reading unit 74 is composed of a reflective optical sensor, and is electrically connected to a control circuit in the apparatus main body 10 via an electric cable (not shown).

In this sensor 70, as long as the connecting member 66 of the torch body 40 is placed on the rectilinear drive member 34, the output signal of the scale reading unit 74 (even if the rectilinear drive member 34 moves up and down at an arbitrary height position ( (Reading value) is kept constant. However, when the rectilinear drive member 34 is separated from the connecting member 66 of the torch body 40, the relative position between the scale portion 72 and the scale reading portion 74 changes, and the output signal (read value) of the scale reading portion 74 changes. The control unit placed in the apparatus main body 10 can monitor the relative positional relationship between the rectilinear drive member 34 and the torch body 40 based on the output signal from the scale reading unit 74, and the rectilinear drive member 34 When the lower end of the torch electrode 44 contacts the joined portion WJ of the base material (W ₁ , W ₂ ) during the forward movement (downward movement), this can be detected. It should be noted that other types of sensors such as proximity sensors may be used instead of the optical sensors using such scales.

  Next, the operation of the bonding apparatus and the brazing method (spot bonding method) in this embodiment will be described with reference to FIGS. 3, 4A to 4F, and 5A to 5E.

First, in the state where the electrical component support S supporting the base material (W ₁ , W ₂ ) of tough pitch copper is placed on the stage 18, the XY stage 26 and the θ stage 27 are as described above. Positioning in the horizontal plane is performed under the control of the internal control unit. By this alignment operation, a preset position on the bonded portion WJ of the base materials (W ₁ , W ₂ ), that is, a position where the lower end of the torch electrode 44 should come into contact for energization start (hereinafter referred to as “energization start”). It is referred to as “position”.) Q is located directly below the torch electrode 44. In the case of spot joining as shown in the example (illustration joining), it is preferable to set the energization start position Q in the gap g or in the vicinity thereof on the top surface of the joined part WJ.

  Usually, since the XY coordinates are assigned to all the joined parts WJ to be joined on the electrical component support S, the alignment operation of the open loop control can be performed. However, it is also possible to perform a feedback control alignment operation using a monitor camera or the like.

When the bonded portion WJ of the base material (W ₁ , W ₂ ) is positioned directly below the torch electrode 44 on the stage 18 as described above, the gap between the filler material feeding device 24 and the bonded portion WJ is determined. But alignment is complete. That is, between the filler material feeding device 24 and the welded portion WJ, the tip of the last-stage sleeve 90 or the tip of the wire-like melt material M is on the welded portion WJ of the base material (W ₁ , W ₂ ). The energization start position Q is pointed obliquely from above (FIG. 5A).

  Apart from the alignment in the horizontal plane as described above, the torch start position of the torch 22 is adjusted to an appropriate height position through the elevating tower 30 by the control unit in the apparatus body 10 also in the height direction. However, when brazing under the same conditions is continuously performed for a plurality of joints of the same type, the brazing of the next time is performed by returning the torch 22 to a certain torch start position after the end of each brazing. Therefore, the initial height position adjustment can be omitted.

The base material (W ₁ , W ₂ ) on the stage 18 under the control of the control unit in the apparatus main body 10 from the state where the alignment or the initial height position has been adjusted as described above (FIG. 4A). Is soldered with the joining head 12. The flowchart of FIG. 3 shows the control procedure of the control unit when one spot bonding is performed. The control unit includes a microcomputer, a memory, various interfaces, and the like, and controls the operation of each unit in the apparatus and the entire sequence according to a predetermined program stored or stored in the memory. Prior to the start of spot welding, the control unit sets (saves) the encoder output value LE _i-1 of the filler material supply amount measuring unit 110 in FIG. 6 in a memory or a resist. Usually, the encoder output value LE _i-1 at the spot joining start, described later filler tip for arrived the tip of the wire-shaped filler material M after the end of the previous spot joining in a predetermined wire start position P _S It corresponds to the encoder output value when the position adjustment is completed.

First, the control unit operates the elevating drive unit of the elevating tower 30 to start the downward movement of the rectilinear drive member 34 (step S ₁ ). Since the lower end of the torch electrode 44 is floating in the air (FIG. 4A), when the downward movement of the linear drive member 34 is started, the torch 22 is also driven linearly with the connecting member 66 placed on the upper surface of the linear drive member 34. It moves downward together with the member 34 (FIG. 4B).

When the lower end of the torch electrode 44 comes into contact with the joined portion WJ at the energization start position Q (or in the vicinity thereof with a slight deviation) (step S ₂ ), the downward movement of the torch 22 ends there (FIG. 4C). Immediately thereafter, when the rectilinear drive member 34 is separated from the connecting member 66 of the torch body 40 (FIG. 4D), the control unit stops the downward movement of the rectilinear drive member 34 in response to the output signal of the sensor 70 (step S ₃ ). .

  Note that the control unit starts supplying the shield gas SG in the middle of the downward movement of the torch 22 or immediately after the end of the downward movement. The shield gas SG is supplied from the cylinder 14 to the torch 22 via the apparatus main body 10 and the hose 38. The torch 22 introduces the shield gas SG into the upper part of the torch body 40 and ejects the introduced shield gas SG from the opening of the torch nozzle 42 at a predetermined flow rate (for example, 5 liters / minute).

Thus, the control unit starts energization under the state where the lower end of the torch electrode 44 is in contact with the energization start position Q (or the vicinity thereof) on the bonded portion WJ (step S ₄ ). That is, the switch SW of the DC power supply circuit 76 composed of a constant current source is switched from the OFF state to the ON state in the apparatus main body 10. Then, the positive electrode of the DC power supply circuit 76 → the switch SW in the ON state → the electric cable 56 → the contacts C ₁ and C ₂ → the joined portion WJ → the torch electrode 44 → the electric cable 39 in the hose 38 → the negative electrode of the DC power supply circuit 76 A constant DC current i flows in the path or the closed circuit 78 (FIG. 5C).

The current value of the direct current i may be kept constant from the start to the end of energization, or may be switched stepwise or continuously in the middle. When maintaining a constant value throughout the energization time, when the arc is generated by separating the lower end of the torch electrode 44 from the welded portion WJ, the wire-shaped filler metal (phosphorous copper brazing) M having a melting point of 640 ° C. is rapidly melting. In addition, the to-be-joined part (tough pitch copper) WJ having a melting point of 1000 ° C. or higher is set to a current value I _M (for example, 70 to 90 A) at which arc heat is obtained that does not melt at all.

Alternatively, at the time of initial energization under this contact state, the current value of the current i may be controlled to a value I _S that is much lower than the value I _M suitable for brazing. That is, in order to extend the life of the torch electrode 44, it is preferable to generate arc discharge as weakly as possible at the moment when the tip of the torch electrode 44 is separated from the bonded portion WJ. On the other hand, in order to improve the wettability of the brazing that is started by separating the tip of the torch electrode 44 from the bonded portion WJ, an appropriate Joule heat is applied to the bonded portion WJ during energization at this stage (under the contact state). It is preferably generated and preheated. In this embodiment, from these two viewpoints, the current value I _S at the start of energization of the current i flowing in the closed circuit 78 is controlled within a range of 10 to 20 A, for example.

When the predetermined time T ₁ has elapsed from the start of energization (step S ₅ ), the control unit moves the linear drive member 34 slightly upward to set the lower end of the torch electrode 44 away from the bonded portion WJ (for example, 3 mm). Only upward (step S ₆ ), it is stopped at that height position. At the same time as or after completion of the separation of the torch electrode 44, the control unit controls the power supply circuit 76 to set the current value of the current i flowing in the closed circuit 78 to the initial current value I _S thus far. It switched to the normal current value I _M for further large soldering or spot welding than (step S _7).

In this way, the lower end of the torch electrode 44 is separated from the bonded portion WJ, and the current (arc current) i having a normal current value I _M flows in the closed circuit 78, whereby the bonded portion (tough pitch copper) having a melting point of 1000 ° C. or higher. ) An arc AC capable of rapidly melting the wire-like filler metal (phosphorous copper brazing) M having a melting point of 640 ° C. with little or no melting of WJ is generated in the space gap between the torch electrode 44 and the joined portion WJ. In particular, it is generated in the space gap between the lower end of the torch electrode 44 and the energization start position Q on the bonded portion WJ.

Then, when a predetermined delay time T ₂ elapses after the tip of the torch electrode 44 is separated from the bonded portion WJ or the current value of the current i in the closed circuit 78 is switched to the normal value I _M (step S). ₈ ) At this timing, the control unit starts supplying the wire-shaped filler metal M into the arc AC through the filler material feeding device 24 (step S ₉ ).

This delay time T ₂ is determined in consideration of the optimum time for improving the wettability and the influence on the base material, and is usually selected in the range of 0.1 to 0.5 seconds. In addition, the operation of the filler material feeding device 24 is started so that the tip of the wire-like filler metal M enters the arc column of the arc AC with the just-in-time when the delay time T ₂ has elapsed. The timing may be slightly advanced.

  In this embodiment, since the tip of the wire-like filler material M is sent from obliquely upward toward the energization start position Q on the joined portion WJ, the wire-like filler material M is surely connected to the lower end of the arc column of the arc AC. It is introduced into the part and melts quickly by receiving arc heat at the introduction position. Then, the melted filler material <M> spreads to the periphery due to the slack, and penetrates into the gap g of the bonded portion WJ or inside (see FIG. 5D).

On the other hand, when the wire-like melt material M is fed into the arc AC by the melt material feeding device 24, the melt-material supply amount measuring unit 110 is moved according to the movement (forward movement) of the wire-like melt material M. Encoder output value E _i changes. The control unit sequentially captures and updates the encoder output value E _i from the filler material supply amount measurement unit 110.

Then, the control unit monitors the encoder output values E _i, when the increment Delta] E of the wire-shaped filler M encoder output values E _i from the start of the supply of has reached the set value Delta] E _S, the set amount The wire-like filler metal M is determined to have been supplied into the arc AC (step S ₁₀ ), and the filler-material feeder 24 is immediately controlled to retract the wire-like filler material M from the arc AC. (Step S ₁₁ ) Next, the switch SW of the power supply circuit 76 is turned off to stop energization (Step S ₁₂ ). Immediately after that, the supply of the shielding gas SG is also stopped. The backward movement speed when retracting the wire-like filler metal M from the arc AC is set to a value (for example, 200 mm / sec) that is several times higher than the forward movement speed during supply (for example, 10 to 80 mm / sec). The The moving distance when retreating is set to 3 mm, for example.

When the wire-like filler material M is retracted from the arc AC, the supply of the filler material to the welded portion WJ is stopped at that moment. When the energization stops, the arc disappears at that moment. When the arc disappears, the melted (liquid) filler material <M> diffused in and around the gap g of the joint WJ is immediately solidified by natural cooling in the atmosphere and solid metal or alloy [ M]. In this way, brazing welding joints (joints) are formed at the joints WJ of the base materials (W ₁ , W ₂ ).

Thereafter, the control unit moves the straight drive member 34 upward through the lift drive unit of the lift tower 30 and returns the torch 22 to the torch start position (step S ₁₃ ).

As described above, in this embodiment, the shield gas SC is supplied around the torch electrode 44 in a state where the tip of the torch electrode 44 is in contact with the bonded portion WJ of the base material (W ₁ , W ₂ ). However, energization is started between the torch electrode 44 and the bonded portion WJ. Then, while continuing to supply and energize the shield gas SC, the tip of the torch electrode 44 is moved away from the joined portion WJ, and the base material (W ₁ , W ₂ ) is placed between the torch electrode 44 and the joined portion WJ. An arc AC is generated that can quickly melt the filler material M with little or no melting. Then, the wire-like filler material M is supplied into the arc AC with a slight delay, the melt material M is melted by the heat of the arc AC, and the melted melt material <M> is diffused by wetting. Immerse in the gap g of the joint WJ. And after a certain period of time (or when the delivery amount or supply amount of the wire-like filler material M reaches the set value), the filler material M is retracted from the arc AC, and then the arc AC is extinguished, The melted (liquid) filler material <M> diffused around the gap g of the joined portion WJ and the periphery thereof is solidified.

Thus, in this embodiment, the arc AC generated between the torch electrode 44 and the bonded portion WJ of the base material (W ₁ , W ₂ ) is not the melting (arc welding) of the bonded portion WJ. Used exclusively for melting the soluble material M. As a result, a metal joint (joint) by brazing is obtained at the joint WJ. Therefore, for example, even if the base material (W ₁ , W ₂ ) is made of tough pitch copper, a blow hole as found in arc welding does not occur in principle.

  In addition, since the arc AC is generated by the touch start method, the wire-like filler material M is fed toward the position (energization start position Q) where the tip of the torch electrode 44 of the joined portion WJ is in contact, so The material M can be surely introduced into the arc column or core portion of the arc AC without being removed and can be melted most efficiently.

  In this embodiment, the amount (length) of the wire-like filler material M supplied to the arc between the torch electrode 44 and the welded portion WJ by the current spot welding by the filler feeding amount measuring unit 110 described later. ) Is measured, and the supply amount of the wire-like filler metal M in one spot joining is always managed as set, and the measured value, that is, the measured value of the filler material supply amount is displayed on the display 46 of the apparatus main body 10. Is provided to the user through a display output or other type of data output. In this type of spot joining, the supply amount of the wire-like filler material M applied to the arc is proportional to the amount of the filler material <M> melted on the welded portion WJ, and consequently the melt filler material <M. > Is proportional to the amount of the alloy [M] formed by solidification, and greatly affects the quality of the brazing process (bonding strength, finish, etc.). The user can utilize the presented melt material supply amount measurement value as a barometer (quality management information) for assuring the quality of the spot joint.

Furthermore, metal bonding formed by brazing is advantageous in terms of yield because it is easy to recover (recover) or redo even if the bonding is defective. Compared with arc welding, the arc heat generated between the torch electrode and the base metal is much weaker, that is, the arc current is much smaller (about 1/2). It has little effect and can save power consumption.

[Configuration of the filler supply amount measurement unit]

  Hereinafter, with reference to FIG. 6 and FIG. 7, the structure of the filler material supply apparatus 24 and the filler material supply amount measurement part 110 in this embodiment is demonstrated.

  As shown in FIG. 6, the filler material feeding device 24 has a wire reel 80 wound around the wire-like filler material M so that the wire-like filler material M can be smoothly fed out, and the wire-like filler material M is desired from the wire reel 80. A feeding roller 82 and a pressing roller 84 for feeding out at a speed, a servo motor (not shown) with a reverse feeding function for rotationally driving the feeding roller 82, and a wire-like filler material M in a straight line at various points on the wire moving path. A strainer 86 and a plurality of sleeves 88, 90,. Here, the sleeves 88 and 90 positioned on the downstream side of the wire moving path are attached to the filler material feeding head 92 disposed near the torch 22 and the joined portion WJ.

  The filler material feeding head 92 is attached to the thick plate-like base member 94 with the filler material guide portions or sleeves 88 and 90 of the filler material feeding device 24 via sleeve holders 96 and 98, respectively. A rotary encoder 112 and a filler material tip position adjusting unit 115 which are main components of the material supply amount measuring unit 110 are attached.

  The rotary encoder 112 is mounted on the base member 94. The rotary encoder 112 may be either an incremental type or an absolute type, and a pulley or roller 112a that rotates following the movement of the wire-like filler metal M and an amount or angle of rotation of the roller 112a are encoders. The main body 112b has an encoder output signal generation unit (not shown) that converts it into an electrical pulse signal.

  More specifically, as shown in FIG. 7, the rotary encoder 112 is arranged on the side of the support plate 116 fixed on the base member 94. On the other hand, a pressing roller 114 disposed to face the roller 112 a of the rotary encoder 112 is attached to a movable support plate 118 that is movably disposed alongside the fixed support plate 116 on the base member 94. A plurality of tension coil springs 124 stretched between the support plates 116 and 118 via spring support rods 120 and 122 allow the pressing roller 114 to elastically move to the roller 112a with the wire-like filler material M interposed therebetween. Pressed. Thereby, the wire-shaped filler metal M can move between the outer peripheral surface of the roller 112a of the rotary encoder 112 and the outer peripheral surface of the pressing roller 114 with almost no slip while receiving a large dynamic friction force.

  Thus, the rotation direction and the rotation amount of the rotary encoder 112 correspond to or are proportional to the movement direction and the movement amount of the wire filler metal M. Thus, an encoder output value representing the moving direction and moving amount of the wire filler metal M can be obtained from the rotary encoder 112.

The filler material tip position adjusting unit 115 is disposed near the tip of the direct acting actuator, for example, the air cylinder 126, which is attached to the lower surface of the base member 94, and the last stage sleeve 90 of the filler material feeding device 24. The position sensor 128 includes an arm-shaped or frame-shaped sensor support 130 that connects the drive shaft 126 a of the air cylinder 126 and the position sensor 128. By operating the air cylinder 126 and moving the drive shaft 126a forward or backward, a standby position P _O set behind the tip of the sleeve 90 on the wire moving path and a wire start position P set forward are set. _The position of the position sensor 128 can be switched with _S. Position sensor 128, the tip position of filler metal M is configured to whether it can, for example optically detected or determined to match or approximate to the nearest monitoring point, that the wire start position P _S.

In this embodiment, the control unit in the apparatus main body 10 has a function of calculating a measured value of the filler material supply amount based on an encoder output value from the rotary encoder 112, and a wire in the filler material tip position adjusting unit 115. the tip of Jo filler M such as wire start position P _S control function for arrived in, plays for any arithmetic function or control function in the filler metal supply amount measuring unit 110.

[Operation of the filler supply amount measuring unit (adjustment of the filler material tip position)]

  Next, with reference to FIG. 8 and FIG. 9, the operation of the filler material supply amount measuring unit 110 in this embodiment, particularly the procedure for adjusting the filler material tip position will be described. FIG. 8 shows the control or calculation procedure of the control unit in the filler material tip position adjustment. FIG. 9 schematically shows each stage of the filler material tip position adjustment.

In this embodiment, once after the spot welding is completed, the filler material tip position adjustment unit 115 under the control of the control section of the wire-like filler M tip for arrive to the wire start position P _S The filler material tip position adjustment is performed.

  As described above, the backward movement distance when the wire-shaped filler metal M is retracted from the arc AC is controlled to a constant value. For this reason, as shown in FIG. 9A, the tip of the wire-like filler material M after the end of spot welding is located somewhat forward of the tip of the sleeve 90. However, even if the processing conditions are the same, the strength and spread of the arc AC are slightly different for each spot welding, and the melting rate of the wire filler M is slightly different, so that the tip of the wire filler M after the spot welding is finished. The position is strictly indefinite.

First, the control unit reads the output value E _i of the rotary encoder 112 that has been stopped after the end of spot welding (step S ₂₀ ). Then, the control unit actuates the air cylinder 126, as shown in (b) of FIG. 9, moves the position sensor 128 which has been waiting at the standby position P _O far to the wire start position P _S (step S ₂₁ ).

Thereafter, the control unit, of FIG. 9 (c), (d), the distance the wire-shaped filler metal M variable through filler metal feeder 24 in the vicinity of the wire start position P _S (δp) Only the forward movement or backward movement (step S ₂₂ ), the process of reading and updating the output value E _i of the encoder 112 after this adjustment movement (step S ₂₃ ), and the position after the adjustment movement through the position sensor 128. The process of determining whether or not the tip position of the wire-like filler material M matches or approximates the wire start position P _S (step S ₂₄ ) is repeated as appropriate, so that the tip position of the wire-like filler material M is changed to the wire. It will close gradually to the start position P _S. Then, as shown in (e) of FIG. 9, when the tip position of the wire-shaped filler material M is equal or close to the wire start position P _S is where adjustment movement of the wire-shaped filler metal M (forward / backward ), And the output value E _i of the encoder 112 at this time is read as the final output value LE _i (step S ₂₅ ).

Next, the control unit determines the final output value LE _i of the rotary encoder 112 determined by the filler material tip position adjustment as described above, and the encoder output value set in the memory or register before the start of the current spot welding. calculates the LE _i-1 and the differential _{(LE i -LE i-1)} , the current wire feed amount measurement value LM _i (step S _26). That is, this difference (LE _i −LE _i−1 ) is the encoder output value LE _i− when the tip position of the wire filler metal M is the same (wire start position P _S ) before and after the current spot welding. ₁ and LE _i , which correspond to the current wire supply amount measurement value LM _i . The control unit stores the wire feed amount measurement value LM _i in the memory (storage), and displays on the display unit 46.

  As described above, in this embodiment, the amount (length) of the wire-like filler metal M supplied to the arc between the torch electrode 44 and the joined portion WJ in the current spot joining is measured through the rotary encoder 112. Since the monitor information of the measured value of the filler material supply amount is provided to the user, the user can provide the measured value of the melt material supply amount to the barometer (quality control information) for assuring the quality of the spot joint. Can be effectively utilized as.

In particular, in this embodiment, a rotary encoder 112 of the melt material supply amount measuring unit 110 is provided in the melt material feed head 92 of the melt material feed device 24, and near the tip of the wire-like melt material M. Since the movement amount or supply amount of the wire-like filler material M is measured, even if the wire-like filler material M bends on the upstream side of the wire movement path, the melt-material supply amount measuring unit 110 is not affected by this time. It is possible to accurately measure the supply amount or consumption amount of the wire-like filler material M in the spot joining.

[Other Embodiments or Modifications]

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above does not limit this invention. Those skilled in the art can make various modifications and changes in specific embodiments without departing from the technical idea and technical scope of the present invention.

  For example, a configuration in which the rotary encoder 112 of the filler material supply amount measuring unit 110 is attached to the feeding roller 82 of the filler material feeding device 24 is also possible. Further, instead of the feeding roller 82, a configuration in which a servo motor is attached to the rotary encoder 112 of the filler material supply amount measuring unit 110 to drive the filler material feeding is also possible. Even in these cases, it is preferable that the filler material tip position adjusting unit 115 is attached to the filler material feeding head 92 of the filler material feeding device 24 as in the above embodiment.

In the above-described embodiment, when the straight drive member 34 further descends after the lower end of the torch electrode 44 comes into contact with the upper surface of the base portion (W ₁ , W ₂ ) to be joined, The weight of the torch 22 was added. As another example (modification), as shown in FIG. 10, between the rectilinear drive member 34 and a part of the torch body 40 (for example, a hook-shaped spring receiving portion 140 fixed to the torch body 40), It is also possible to provide a spring member that can be elastically deformed in the direction in which the linear drive member 34 moves, for example, a coil spring 142. In this case, by using a compression coil spring for the coil spring 142, the load received by the bonded portion WJ when the torch electrode 44 comes into contact with the bonded portion WJ can be arbitrarily reduced from the own weight of the torch body 40. This is an advantageous form when the base material (W ₁ , W ₂ ) is a terminal member of a small precision electronic component. Alternatively, by using a tension coil spring as the coil spring 142, the load received by the welded portion WJ when the torch electrode 44 comes into contact with the welded portion WJ can be arbitrarily increased from the own weight of the torch body 40. The spring force of the coil spring 142 can be adjusted by providing a mechanism (not shown) for adjusting the position of the spring receiving portion 140.

  In the configuration in which the torch body 40 is attached to the rectilinear drive member 34 via the coil spring 142 in this way, the rectilinear drive member 34 may be moved linearly in an oblique direction or a horizontal direction, and the torch electrode 44 may be moved linearly in the same direction. Is possible.

  The plate-like form of the rectilinear drive member 34 in the above-described embodiment is an example, and the rectilinear drive member 34 can take the structure of a plate, a block, a cylinder, and a housing having an arbitrary shape. Similarly, the connecting member 66 can take any form.

  In the above-described embodiment, the torch 22 is directly attached to the rectilinear drive member 34. However, as shown in FIG. 11, a rectilinear movable member 144 such as an elevating rod is attached to the rectilinear drive member 34 so as to be integrally movable and separable in the vertical direction, and a torch is attached to a holder 146 coupled to the rectilinear movable member 144. The structure which attaches 22 so that attachment or detachment is possible is also possible.

Further, in the above-described embodiment, worship joining is performed in which the tip portions of the _two metal members W ₁ and W ₂ are joined together by brazing. However, although not shown in the drawing, it is possible to perform butt joining in which the tips or side surfaces of the _two metal members W ₁ and W ₂ are butted and brazed, and furthermore, the two metal members W ₁ and W ₂ are overlapped and brazed. Superposition joining is also possible.

  In addition, when supplying the wire-like melt material M in the arc AC, it is most preferable to send the melt material M aiming at the energization start position Q on the welded portion WJ. However, it is also possible to feed the filler material M directly over the energization start position Q, that is, through the gap between the tip of the torch electrode 44 and the energization start position Q. The shape of the filler material M is arbitrary, and is not limited to a wire, but may be, for example, a rod or a plate.

  Although the joining apparatus in the above embodiment is a stationary type, a form mounted on a robot is also possible. In that case, the linear drive member 34 or the lifting support shaft 32 may be coupled to the robot arm. Similarly, the filler material feeding device 24 may be mounted on the same robot together with the torch 22 or may be mounted on another robot.

  The bonding apparatus in the embodiment includes the automatic alignment mechanism (XY stage 25, θ stage 26) on the stage 18 of the bonding head 12. However, the stage 18 can be configured as a manually movable stage, or the workpiece or the electrical component support S can be manually positioned on the fixed stage 18.

In the joined portion WJ, the material of the metal members W ₁ and W ₂ is not limited to copper or a copper alloy, and may be a conductor such as aluminum, aluminum alloy, or brass, and the material and terminals of the terminal member W ₁ the material of the member W ₂ may be different. Further, the shape of the metal members W ₁ and W ₂ may be arbitrary, and for example, the metal member W ₁ or W ₂ is not limited to a rod or plate having a rectangular cross section, and may be a rod or plate having a circular cross section.

Further, during spot welding, the controller controls the power supply circuit 76 so as to monitor the temperature of the bonded portion WJ using a temperature sensor, for example, a radiation thermometer, and to control the monitored temperature to a constant value or a certain range. It is also possible to variably control the initial current value I _S of the current i.

More specifically, the control unit monitors the temperature of the welded portion WJ through the temperature sensor while supplying the wire-like melted material M into the arc AC through the melt material feeding device 24, and The arc current i is controlled so that the temperature of WJ is higher than the melting point of the filler metal M and does not exceed the melting points of the base materials (W ₁ , W ₂ ). More specifically, the measured temperature of the bonded portion WJ is equal to or approximates a predetermined reference temperature (for example, 750 ° C.) that is higher than the melting point of the filler metal M and lower than the melting point of the base materials (W ₁ , W ₂ ). Thus, the current value I _M of the arc current i is controlled. For example, when the measured temperature of the welded portion WJ falls below the reference temperature, the current value I _M of the arc current i is increased to about 100 A, and when the measured temperature of the welded portion WJ exceeds the reference temperature, the arc current i The control for reducing the current value I _M to about 10 A is repeated.

  By controlling the temperature of the welded portion WJ and thus the temperature at which the wire filler metal M is melted, the efficiency, reliability and reproduction of brazing performed using the arc heat of the arc AC are controlled. Can be improved.

In addition to the radiation thermometer, for example, a thermocouple can be used as the temperature sensor. In that case, it is preferable to attach the contacts C ₁ and C ₂ (FIG. 2) rather than directly attaching the thermocouple to the bonded portion WJ.

DESCRIPTION OF SYMBOLS 10 Apparatus main body 12 Joining head 18 Movable stage 22 Torch 24 Filler material feeding apparatus 30 Lifting tower 34 Straight drive member 40 Torch body 44 Torch electrode 110 Filler material supply amount measuring part 112 Rotary encoder 115 Filler material front end position adjusting part 128 position sensor

Claims (7)

A joining device for joining the joined parts of the first and second metal members,
An arc generating part that has a non-consumable torch electrode and generates an arc that melts the to-be-joined part at all or hardly between the torch electrode and the to-be-joined part;
Sending a wire-like or rod-like filler material toward the arc, and supplying a predetermined amount of the filler material, and then feeding the filler material away from the arc;
A filler material supply amount measuring unit for measuring the amount of said filler material supplied to the arc possess by the filler material feeder by bonding a single operation,
The filler material supply amount measuring unit includes an encoder for successively measuring the amount of movement when the filler material advances or retracts in the filler material supply unit, and before the start of one joining operation and A filler material tip position adjusting portion for causing the tip of the filler material to reach a predetermined wire start position after completion, and when the tip of the filler material arrives at the wire start position before the start of the joining operation From the first encoder output value obtained from the encoder and the second encoder output value obtained from the encoder when the tip of the filler material arrives at the wire start position after completion of the joining operation. An arithmetic unit for obtaining a measurement value of the amount of the filler material supplied to the arc, and measuring the supply amount of the filler material with the tip of the filler material as a mark,
Joining device. The joining apparatus according to claim 1 , wherein the filler material tip position adjusting unit includes a position sensor for detecting a tip of the filler material at the wire start position. The arc generator includes a torch body that detachably mounts and holds the torch electrode, a power source for flowing a current in a closed circuit including the torch electrode and the bonded portion, and the bonded portion A moving mechanism that relatively moves the torch body, and starts energization in the closed circuit in a state where the tip of the torch electrode is in contact with the joined portion, and energization in the closed circuit The arc is generated between the torch electrode and the bonded portion by separating the tip of the torch electrode from the bonded portion while continuing ,
The moving mechanism includes a rectilinear drive member capable of linearly moving the torch body in parallel with the axial direction of the torch electrode with respect to the bonded portion, and a first mechanism for moving the torch electrode away from the bonded portion. A second position for bringing the tip of the torch electrode into contact with the joined portion, and a third position for separating the tip of the torch electrode from the joined portion by a predetermined distance suitable for arc generation. Moving the rectilinear drive member linearly between
The joining apparatus according to claim 1 . The joining apparatus according to claim 3 , wherein the filler material feeding unit supplies the filler material to a portion where the torch electrode of the joined portion is in contact. The filler metal feeder supplies the filler material on him the gap between the portion where the the tip of the torch electrode the torch electrode bonding portion was in contact, according to claim 3 Welding equipment. The joining apparatus according to claim 3 , wherein the filler material feeding unit puts the filler material into the arc after a delay of 0.1 to 0.5 seconds after the occurrence of the arc. The joining apparatus of Claim 3 which sets the location which the said torch electrode of the said to-be-joined part should contact in the clearance gap between the said to-be-joined parts, or its vicinity.

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