JP6238766B2 - Welding equipment - Google Patents

Description

  The present invention relates to a welding apparatus, and more particularly to a welding apparatus suitable for joining objects to be joined made of a laminate of a plurality of metal plates.

  In recent years, a stacked lithium ion battery in which a plurality of plate-like positive electrode and negative electrode are stacked via a separator has been used. FIG. 5A is a perspective view showing a state after lamination of the laminated lithium ion battery, and FIG. 5B is a perspective view showing a state where the tabs of the electrodes and the lead terminals are connected.

  In the stacked lithium ion battery, as shown in FIG. 5A, a positive electrode 100 made of a metal foil such as aluminum (Al) and a negative electrode 101 made of a metal foil such as copper (Cu) are separated from each other (not shown). ) Are alternately stacked. Each positive electrode 100 is provided with tabs 102 for lead joining. These tabs 102 are stacked as shown in FIG. 5B, and joined with lead terminals 104 for external connection at the joint 106. Is done. Similarly, each negative electrode 101 is provided with a tab 103 for lead bonding. These tabs 103 are stacked and bonded to a lead terminal 105 for external connection at a bonding portion 107.

  Conventionally, ultrasonic welding is used for joining the tab 102 and the lead terminal 104 and joining the tab 103 and the lead terminal 105. Ultrasonic welding is a method of joining by applying ultrasonic vibration parallel to the joining surface while applying a vertical pressure to the workpieces. However, ultrasonic welding has a problem that minute metal powder falls off the battery due to ultrasonic vibration during welding. In addition, if the number of tabs increases due to the increase in the number of electrodes due to the increase in battery capacity, the required welding energy increases, so it is necessary to increase the output of ultrasonic waves, and the tabs may be torn or cut. It was. In addition, there is a problem that the life of the ultrasonic equipment is shortened due to an increase in welding energy.

In view of this, a method has been proposed in which the object to be bonded is temporarily fixed by ultrasonic welding within a range in which the object to be bonded is not damaged or metal powder is generated (see Patent Document 1).
Resistance welding is a method of joining by joining an object to be joined between a pair of electrodes from above and below, passing an electric current between the electrodes, and melting the object to be joined by Joule heat generated.

Japanese Patent No. 5091171

According to the method disclosed in Patent Document 1, it is possible to suppress damage to an object to be joined, generation of metal powder, and shortening of the life of an ultrasonic device, which are problems in ultrasonic welding.
However, when resistance welding a plurality of plates made of Al (Al foil) as described above, the electric resistance of Al is low and it is difficult to generate heat. There was a problem that it was necessary. In addition, it is necessary to pass a large current through the electrode, and there is a problem that consumption of the electrode that becomes high temperature is severe. In particular, when a plurality of Al foils are joined using a commonly used Cu alloy electrode, Cu and Al, which are the main components of the electrode, are alloyed to form a Cu-Al alloy. As a result, the tip of the electrode is significantly consumed, so the electrode must be frequently polished.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a welding apparatus capable of realizing appropriate welding even when a laminated body of a plurality of plates is welded.

The welding apparatus according to the present invention includes an ultrasonic welding machine that applies ultrasonic vibration to a workpiece to temporarily fix the workpiece by ultrasonic welding, and irradiates laser beam to a temporary fixing portion of the workpiece. controls laser welding machine for laser welding, and prior Symbol object to be bonded to be able to move in the horizontal direction XY stage, the ultrasonic welder and the laser welder and the XY stage Te, the ultrasonic welding A control unit that performs the laser welding by moving the object to be bonded below the laser irradiation unit of the laser welding machine after the execution of the ultrasonic welding machine, wherein the ultrasonic welding machine An ultrasonic oscillating horn that simultaneously applies sonic vibrations is provided, and the control unit sequentially irradiates a plurality of temporary fixing points of the object to be bonded from the laser irradiation unit.
Moreover, one structural example of the welding apparatus of this invention WHEREIN: The said laser irradiation part is equipped with the galvano scanner for irradiating a laser beam to the several temporary fix location of the said to-be-joined object, It is characterized by the above-mentioned .

  According to the present invention, the temporary joining of the object to be joined by ultrasonic welding and the main welding of the object to be joined by laser welding make it possible to damage the object to be joined or cause the generation of metal powder that causes problems in conventional ultrasonic welding. Therefore, it is possible to suppress the shortening of the life of the ultrasonic welding machine, and it is not necessary to use a large capacity welding machine such as conventional resistance welding. Appropriate welding can be realized.

  Moreover, in this invention, since it becomes possible to weld several temporary fix locations one by one in order by using laser welding, the large area of a to-be-joined object can be welded.

  Further, in the present invention, by using a galvano scanner, it is possible to irradiate a plurality of temporarily fixed portions with laser light in a short time.

It is a block diagram which shows the structure of the welding apparatus which concerns on embodiment of this invention. It is a figure explaining operation | movement of the ultrasonic welding in embodiment of this invention. It is the top view and sectional drawing of the to-be-joined object after ultrasonic welding. It is a figure explaining operation | movement of the laser welding in embodiment of this invention. It is a perspective view which shows the state after lamination | stacking of a lamination type lithium ion battery, and the state which connected the tab and lead terminal of the electrode.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a welding apparatus according to an embodiment of the present invention. The welding apparatus according to the present embodiment is capable of moving the ultrasonic oscillation horn 1 that applies ultrasonic vibration to the workpiece 10 and the ultrasonic oscillation horn 1 in the vertical direction. A vertical mechanism 2 that can be pressed by the oscillation horn 1, a power source 3 that supplies power to the ultrasonic oscillation horn 1, an XY stage 4 that can move the workpiece 10 in the horizontal direction, and a laser welding machine 5, a galvano scanner 7 (laser irradiation unit) that irradiates the workpiece 10 with laser light transmitted from the laser welding machine 5 through the optical fiber 6, and a control unit 8 that controls the entire welding apparatus. The ultrasonic oscillating horn 1, the vertical mechanism 2, and the power source 3 constitute an ultrasonic welding machine.

  Next, the bonded object 10 of the present embodiment will be described. The object to be bonded 10 includes a plate member 11 made of Al or an Al alloy (lead terminals 104 and 105 in FIGS. 5A and 5B) and Al or Al disposed on the plate member 11. Laminated body 12 (tabs 102 and 103 in FIGS. 5A and 5B) made of a plurality of plates made of an alloy, and a protective plate made of Al or Al alloy disposed on laminated body 12 And the like member 13. The thickness of the plate member 11 is, for example, about 1 mm. The thickness per sheet of the plurality of sheets (Al foil) constituting the laminate 12 is, for example, about 10 μm to 150 μm. The plate-like member 13 is provided for the purpose of preventing the laminated body 12 from being damaged. The plate member 13 is preferably made of the same material as the laminate 12. The thickness of the plate-like member 13 is about 100 μm, for example.

  Hereinafter, the operation of the welding apparatus will be described. First, the control unit 8 moves the XY stage 4 in the horizontal direction (the direction perpendicular to the stacking direction of the stacked body) to move the workpiece 10 to a position directly below the ultrasonic oscillating horn 1, thereby moving the vertical mechanism 2, the ultrasonic oscillating horn 1 is lowered to pressurize the workpiece 10 from above as shown in Fig. 2. In this state, the control unit 8 supplies power to the ultrasonic oscillating horn 1 from the power source 3. As a result, the ultrasonic oscillating horn 1 generates ultrasonic vibrations.

  When ultrasonic vibration is applied from the ultrasonic oscillating horn 1 to the workpiece 10, the workpiece 10 is melted by frictional heat generated on the bonding surface (bonding surface between the plates) of the workpiece 10. However, in the present embodiment, the energy of ultrasonic vibration is lowered as compared with normal ultrasonic welding. That is, the cumulative value of the ultrasonic vibration energy of the present embodiment is lower than the cumulative value of the ultrasonic vibration energy necessary for welding the workpiece 10 only by ultrasonic welding. Supply power from the power source 3 and power supply time (welding time) are set in advance. In this way, by temporarily reducing the energy of ultrasonic vibration, temporary fixing is performed to such an extent that the plates of the object to be bonded 10 are in close contact with each other. The user of the welding apparatus performs a welding test for setting welding conditions in advance using the object to be joined 10, and the plates of the object to be joined 10 are within a range in which damage to the object 10 and metal powder do not occur. What is necessary is just to preset the power supply value and welding time at the time of close_contact | adherence in the memory | storage part 18. FIG.

  A plurality of ribs (protrusions) 9 are two-dimensionally arranged on the tip surface of the ultrasonic oscillating horn 1 facing the object to be bonded 10, and vibration is generated at the contact portion between the rib 9 and the object to be bonded 10. Concentrate energy. Therefore, as shown in the plan view of FIG. 3A, a plurality of temporary fixing points 20 are formed on the article 10 after ultrasonic welding. Further, as shown in the cross-sectional view of FIG. 3B, a depression is generated in the temporary fixing portion 20 due to pressurization and melting during ultrasonic welding.

After the ultrasonic welding is completed, the control unit 8 moves the XY stage 4 to move the workpiece 10 to a position directly below the galvano scanner 7. The galvano scanner 7 includes a mirror that reflects the laser beam transmitted from the laser welding machine 5 through the optical fiber 6 and a motor that moves the mirror, so that the laser beam from the laser welding machine 5 can be irradiated to a desired position. It has become.
The control unit 8 controls the laser welding machine 5 and the galvano scanner 7 to sequentially irradiate a plurality of temporary fixing points 20 of the workpiece 10 with laser light as shown in FIG.

  By irradiating the laser beam, the object to be bonded 10 at the temporary fixing point 20 is heated and melted to obtain bonding. If the workpiece 10 is moved to a predetermined position directly below the ultrasonic oscillating horn 1, the temporary fastening location 20 on the workpiece 10 is determined by the arrangement of the ribs 9 of the ultrasonic horn 1. , Become a known position. Then, if the article to be bonded 10 is moved to a predetermined position directly below the galvano scanner 7, the laser beam may be irradiated to the position of the known temporary fixing point 20. The positioning with the position can be easily realized. The control unit 8 controls the laser welding machine 5 to set welding conditions and moves the galvano scanner 7 to control the irradiation position of the laser beam.

  The laser output value and laser irradiation time (welding time) per location of the workpiece 10 are preset in the storage unit 15. The user of the welding apparatus performs a welding test for setting welding conditions in advance using the object to be joined 10, and presets the laser output value and welding time when appropriate welding is obtained in the storage unit 15. You just have to.

  Thus, in the present embodiment, the workpiece 10 is temporarily fixed by ultrasonic welding, and the welding of the workpiece 10 is performed by laser welding. In the present embodiment, by reducing the energy of ultrasonic vibration, it is possible to suppress damage to the workpiece 10, generation of metal powder, and shortening of the life of the ultrasonic oscillating horn 1, which are problems in ultrasonic welding. it can. Further, by using laser welding, it is possible to weld a plurality of temporary fixing points 20 one by one in order, so that a wide area of the workpiece 10 can be welded, as in the case of resistance welding. A large-capacity welding machine is not required. Further, in the present embodiment, by using the galvano scanner 7, it is possible to irradiate the plurality of temporary fixing points 20 with laser light in a short time.

  The control unit 8 according to the present embodiment can be realized by a computer having a CPU (Central Processing Unit), a storage device, and an interface, and a program that controls these hardware resources. The CPU executes the processing described in the present embodiment in accordance with a program stored in the storage device.

  The present invention can be applied to a technique for joining a laminate of a plurality of metal plates.

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic oscillation horn, 2 ... Vertical mechanism, 3 ... Power supply, 4 ... XY stage, 5 ... Laser welding machine, 6 ... Optical fiber, 7 ... Galvano scanner, 8 ... Control part, 9 ... Rib, 10 ... Joined Thing, 11, 13 ... plate-like member, 12 ... laminated body, 15 ... memory | storage part, 20 ... temporary fix location.

Claims (2)

An ultrasonic welding machine that applies ultrasonic vibration to the object to be bonded and temporarily fixes the object to be bonded by ultrasonic welding;
A laser welding machine that performs laser welding by irradiating a laser beam to a temporarily fixed portion of the workpiece ;
An XY stage capable of moving the object to be joined in a horizontal direction;
The ultrasonic welding machine, the laser welding machine, and the XY stage are controlled, and the laser welding is performed by moving the workpiece under the laser irradiation unit of the laser welding machine after performing the ultrasonic welding. And a control unit that
The ultrasonic welding machine includes an ultrasonic oscillating horn that simultaneously applies ultrasonic vibrations to a plurality of locations of the objects to be joined,
The said control part is a welding apparatus characterized by irradiating a laser beam to the some temporary fix location of the said to-be-joined object sequentially from the said laser irradiation part . The welding device according to claim 1 ,
The said laser irradiation part is equipped with the galvano scanner for irradiating a laser beam to the several temporary fix location of the said to-be-joined object, The welding apparatus characterized by the above-mentioned.

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