JP2001205452A - Ultrasonic welding equipment, ultrasonic welding method, closed battery and producing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic welding equipment and method which prevent sticking and to provide a closed battery and a producing method thereof in which a relief valve is accurately operated. SOLUTION: This ultrasonic welding equipment is provided with an anvil 6 which supports a body to be welded, a horn 2 which clamps and presses the body to be welded with the anvil and moves back and forth in a direction approximately vertical to the clamping and pressing direction, an ultrasonic actuator 1 which reciprocates the horn, and a clamping and pressing mechanism 5 which clamps and presses the body to be welded between the horn and anvil. Therein, at least one part of the contact surface of horn with the body to be welded or the contact surface of anvil with the body to be welded is formed of ceramic and, thereby, the sticking is prevented. Further, a rupture disk and an energizing plate are welded by using this ultrasonic welding equipment and this closed battery is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic welding apparatus, an ultrasonic welding method, a sealed battery, and a method of manufacturing the same.

[0002]

2. Description of the Related Art First, problems of a conventional ultrasonic welding device will be described, and problems of a sealed battery manufactured by using the conventional ultrasonic welding device will be described.

[0003] In the ultrasonic welding method, ultrasonic vibration is applied to a horn tip at the tip of a horn by an ultrasonic actuator, and the horn tip presses and vibrates a joint surface of a workpiece to be welded supported on an anvil. This is a welding method for welding. The surface of the joint surface of the workpiece is destroyed by ultrasonic vibration, and the joint is diffusion-bonded in a solid phase.

[0004] This ultrasonic welding method has "low heat generation during welding, little change in physical properties and little embrittlement", "possible to join different materials which cannot be achieved by fusion welding", "flux and insert materials". However, when applied to the welding of light metals such as aluminum, the object to be welded adheres to the horn tip or anvil.
There was a problem that the phenomenon occurs. That is,
As a result of the horn tip's pressurization and ultrasonic vibration acting not only on the joint surface of the work piece but also on the contact surface between the horn tip and the work piece and the contact surface between the anvil and the work piece, sticking occurs. It will be. Once this sticking occurs, the work pieces are deposited one after another, and the contact surface with the horn tip and the anvil is deformed in the work pieces. There were problems such as a decrease in the durability of the tip and the anvil, and a problem that ultrasonic welding having a desired bonding strength could not be performed due to the sticking.

In order to solve the problem caused by such sticking, as shown in Japanese Patent Application Laid-Open No. 7-124761,
A method of applying an organic substance such as oil to a contact surface of a horn or an anvil has been proposed. However, in this method, "40
"Continuous welding can be performed only about 0 times", or "It is necessary to remove organic substances attached to the workpiece after welding", or "A mechanism is required to apply an appropriate amount of organic substances to the horn or anvil". Is not practical because of the drawbacks of

Therefore, at present, there is no effective ultrasonic welding apparatus for avoiding sticking.
For this reason, even a work to be welded by the current ultrasonic welding apparatus is used for a product or the like while including a problem caused by sticking. Therefore, many problems occur when manufacturing and using these products and the like. This problem is particularly remarkable in sealed batteries. Therefore, a problem in a case where parts of a battery are welded using a conventional ultrasonic device will be described below.

[0007] When the temperature of the sealed battery rises abnormally or when the battery is charged with an excessive voltage, an abnormal gas may be generated inside the outer can housing and the internal pressure may increase. At this time, if gas is blown out of the battery, there is a risk that the equipment using the battery may fail.If the internal pressure exceeds a predetermined value, the electrical conduction is automatically cut off, and the gas is further discharged. It has a safety valve that has a function that is not generated. Specifically, when a predetermined internal pressure is applied to the inside of the housing, the rupture disk is deformed and separated from the current-carrying plate that has been fixed to each other in advance.

[0008] When the conduction is interrupted in this way, there is no possibility that the gas will be generated any more, so that it is possible to prevent the ejection of the gas.

In order to satisfy the above functions, the rupture disk and the conductive plate need to be joined with a predetermined joining force. If the bonding force between the rupture disk and the conducting plate is too strong, the current is not interrupted even if the internal pressure exceeds a predetermined value, and this may cause a rupture of the outer can housing, which is very dangerous. On the other hand, if the joining force is too weak, the current may be interrupted despite normal use. Therefore, the rupture disk and the conductive plate need to be joined with an accurate joining force. When the outer can housing is made of iron (nickel plating), the rupture disk and the like are practically made of aluminum.

[0010]

Therefore, recently, ultrasonic welding, in which an object to be welded is sandwiched between a horn tip and an anvil to perform welding, has been used for joining a rupture disk and a current-carrying plate. In ultrasonic welding, a stable joining force can be obtained by clamping an object to be welded at a predetermined pressure and performing ultrasonic vibration at a predetermined frequency and amplitude. However, when the conventional ultrasonic welding device is used, a problem caused by sticking has occurred as described above. Specifically, the rupture disk is deformed or damaged, so that the rupture disk is cracked before the conduction is interrupted and gas is destroyed to the outside, or there is not enough bonding force, There is a problem that conduction is interrupted even at an internal pressure.

As described above, the conventional ultrasonic welding apparatus and the battery welded by the ultrasonic welding apparatus have various problems caused by the sticking phenomenon.

Accordingly, the present invention provides an ultrasonic welding device and an ultrasonic welding method for preventing the sticking phenomenon, and also provides a battery produced by using the ultrasonic welding device and the ultrasonic welding method, and a method for manufacturing the same. The purpose is to:

[0013]

According to the present invention, there is provided an anvil for supporting an object to be welded, and a horn for compressing the object to be welded against the anvil and reciprocating in a direction substantially perpendicular to the direction of the pressure. An ultrasonic actuator that causes the horn to make the reciprocating motion; and a squeezing mechanism that squeezes the object to be welded between the horn and the anvil. Or at least one of the contact surface of the anvil and the contact surface of the anvil with the workpiece to be welded is made of ceramics.

In this ultrasonic welding apparatus, ceramics are coated on the contact surface of the horn with the workpiece and / or the contact surface of the anvil with the workpiece. Non-metallic ceramics have the property of not adhering to metals and having sufficient hardness. Therefore, even when vibration and pressure are applied during ultrasonic welding, a sticking phenomenon in which a part of the workpiece adheres does not occur, and the resistance of the horn and the anvil can be improved. Also,
Since the occurrence of scratches and incomplete welding due to the sticking phenomenon are reduced in the workpiece, the yield can be improved.

Further, according to the present invention, an anvil for supporting an object to be welded, a horn for nipping the object to be welded against the anvil, and performing a reciprocating motion in a direction substantially perpendicular to the nipping direction, and An ultrasonic welding apparatus comprising: an ultrasonic actuator that performs a reciprocating motion; and a squeezing mechanism that squeezes the workpiece with the horn and the anvil.
An ultrasonic welding apparatus, wherein at least one of a contact surface of the horn with the workpiece and a contact surface of the anvil with the workpiece is formed of diamond-like carbon.

Further, according to the present invention, in the ultrasonic welding apparatus, the anvil can be supported so that the movement in the direction substantially perpendicular to the pinching direction is restricted by the fitting with the workpiece. An ultrasonic welding apparatus characterized by being an anvil having a shape.

In a conventional ultrasonic welding apparatus, as a method for fixing an object to be welded and an anvil or a horn, an anvil or a horn is formed by forming a contact surface into a fine uneven shape and clamping the anvil or the horn with a sufficiently large pressure. The method of making it bite into a workpiece and fixing it was used.

However, when the work to be welded is a thin part or has a three-dimensional shape, the usual fixing method may cause the anvil or horn to bite into the work and damage the welded part. The shape may be damaged by the narrow pressure. Therefore, by forming the anvil shape to fit into the shape of the workpiece, the workpiece can be fixed without impairing the shape of the workpiece. Furthermore, in the case of fixing by such fitting, adhesion may occur due to friction at the contact surface between the workpiece and the anvil. However, by coating this contact surface with ceramics, it is necessary to prevent such adhesion beforehand. Becomes possible. As described above, suitable ultrasonic welding can be performed without impairing the shape of the workpiece.

Further, according to the present invention, by pressing the two members between the horn and the anvil and reciprocating the horn in a direction substantially perpendicular to the pressing direction,
In the ultrasonic welding method for ultrasonically welding two members, one or both of the horn and the anvil have a contact surface with the member formed of ceramics, and the member is formed through the contact surface. Is an ultrasonic welding method characterized by pinching pressure.

Further, according to the present invention, by pressing the two members between the horn and the anvil and reciprocating the horn in a direction substantially perpendicular to the pressing direction,
In the ultrasonic welding method of ultrasonically welding two members, one or both of the horn and the anvil has a contact surface with the member formed of diamond-like carbon, and through the contact surface An ultrasonic welding method comprising clamping the member.

Further, in the ultrasonic welding method, the other member may be ultrasonically welded in a state in which a movement in a direction substantially perpendicular to the pinching direction is restrained by fitting with the anvil. This is a characteristic ultrasonic welding method.

The ultrasonic welding method is characterized in that the ceramic is a ceramic containing chromium nitride or titanium nitride as a main component.

These ceramics can be easily coated on a horn or anvil by CVD or sputtering.

Further, according to the present invention, an insertion step of inserting a power generating element having a positive electrode and a negative electrode opposed to each other with a separator therebetween into an outer can housing having an opening; A connection step of electrically connecting to the bottom surface of the can housing, and after the connection step, a step of injecting an electrolytic solution inside the outer can housing, and when the pressure inside the outer can housing reaches a predetermined value. The rupture disk and the metal plate extending from the negative electrode or the positive electrode are welded by ultrasonic welding so that the shape is changed and the welded portion is separated and electrical conduction is interrupted. An ultrasonic welding step, a step of electrically connecting the rupture disk and the lid, and a step of closing the opening using the lid and sealing the outer can housing. In the manufacturing method of sealed batteries The ultrasonic welding step is to ultrasonically weld the metal plate and the rupture disk by using an anvil made of ceramic having a shape to be fitted to the rupture disk and having a contact surface with the rupture disk made of ceramics. A method for producing a sealed battery characterized by the following.

According to this method, it is possible to perform ultrasonic welding without damaging the shape of the rupture disk or making a scratch or the like. Therefore, it is possible to manufacture a sealed battery in which accurate operation of the rupture disk is guaranteed. It becomes possible.

Further, according to the present invention, an outer can housing having an opening, a power generating element having a positive electrode and a negative electrode inside the outer can housing and facing each other with a separator interposed therebetween; First connecting means for electrically connecting the outer can housing bottom surface, a lid for covering the outer can housing opening, the positive electrode or the negative electrode, and electrically connecting the lid The second connecting means to be connected and the intermediate means between the first connecting means or the second connecting means are provided, and the first or second connecting means is connected by ultrasonic welding. A sealed battery comprising: a rupture disk made of aluminum, which cuts off electrical conduction when the pressure inside the outer can housing reaches a predetermined value; and an electrolyte injected into the outer can housing. In the ultrasonic welding, A sealed battery, wherein a contact surface with a rupture disk is supported by an anvil made of ceramics and is ultrasonically welded to the first or second connection means.

[0027]

(First Embodiment) A first embodiment relates to an ultrasonic welding apparatus according to the present invention.

The configuration of the ultrasonic welding apparatus will be described with reference to FIG.

The ultrasonic welding device presses the workpiece to be welded between the ultrasonic actuator 1, the horn 2 connected to the ultrasonic actuator 1, the anvil 6, and the horn 2 and the anvil 6. And a pressurizing mechanism 5.

Hereinafter, each component will be described.

The ultrasonic actuator 1 reciprocates in the horizontal direction at a frequency of, for example, 40 kHz and an amplitude of 10 μm, as shown by an arrow 9 in FIG.

The horn 2 is connected to the ultrasonic actuator 1. The length and shape of the horn 2 are designed so that the horn tip 3 at the tip of the horn 2 resonates with the reciprocating motion of the ultrasonic actuator 1. Accordingly, the tip of the horn tip 3 moves in the direction of arrow 9 in conjunction with the reciprocating motion of the ultrasonic actuator 1 in a frequency of 40 kHz and amplitude
Reciprocate at 0 μm.

In the case of ultrasonic welding, the horn tip 3
It is desirable that the workpiece 8 that is in direct contact with the horn tip 3 be fixed to the horn tip 3. Accordingly, the pressing surface 4 on the bottom surface of the horn chip 3 has a fine uneven shape as shown in FIG. The material of the horn 2 is SKD and the contact surface is quenched. The pressing surface 4 is coated with diamond-like carbon using a CVD method.

The anvil 6 is placed vertically below the horn tip 3 to sandwich the two workpieces 7 and 8 with the horn tip 3.

It is desirable that the workpiece 7 in direct contact with the anvil 6 be fixed to the anvil 6 during ultrasonic welding. Therefore, the contact surface between the anvil 6 and the workpiece 7 has a fine uneven shape. The material of the anvil 6 is quenched by SKD. The contact surface is coated with diamond-like carbon using a CVD method.

The pressing mechanism 5 is configured to apply a pressure for pressing the two workpieces 7 and 8 between the horn tip 3 and the anvil 6.

The operation of ultrasonic welding based on the above configuration will be described.

First, the two workpieces 7 and 8 will be described.

The workpiece 7 to be in direct contact with the anvil 6 is an aluminum plate.

Workpiece 8 to be in direct contact with horn tip 3
Is an aluminum plate.

The workpiece 7 is placed on the anvil 6, and the workpiece 8 is placed in the gap between the workpiece 7 and the horn tip 3, and ultrasonic welding is performed.

First, the pressure mechanism 5 is operated. Then, between the pressing surface 4 and the horn tip 3, the workpieces 7 and 8 are welded.
Is pinched. Thereafter, the ultrasonic actuator 1 is operated. Then, the horn tip 3 reciprocates in conjunction with the reciprocation of the horn 2 as shown in FIG.

The operation of the contact surface between the horn tip 3 and the workpiece 8, the contact surface between the workpiece 8 and the workpiece 7, and the contact surface between the workpiece 7 and the anvil 6 will be described below.

At the contact surface between the horn tip 3 and the workpiece 8, the convex portion on the surface of the pressing surface 4 bites into the workpiece 8 due to the pressure of the pressing mechanism 5. Due to this biting, the workpiece 8 reciprocates in conjunction with the reciprocation of the horn tip 3.

Since the pressing surface 4 is coated with diamond-like carbon, there is no possibility that the workpiece 8 made of aluminum adheres to the convex portion of the pressing surface 4.

Next, the contact surface between the workpiece 7 and the anvil 6 will be described.

Also at the contact surface between the workpiece 7 and the anvil 6, the projection of the contact surface is
Bites into the workpiece 7. Due to this biting, the workpiece 7 is fixed to the anvil 6.

Since the contact surface is coated with diamond-like carbon similarly to the pressing surface 4,
There is no possibility that the workpiece 7 made of aluminum adheres to the convex portion of the contact surface.

Next, the contact surface between the workpiece 7 and the workpiece 8 will be described.

The workpiece 8 reciprocates in conjunction with the reciprocating motion of the horn tip 3, while the workpiece 7 is
It is stationary because it is fixed to the anvil 6. Therefore, the workpiece 7 and the workpiece 8 are rubbed. Oxide on the surfaces of the workpieces 7 and 8 is removed by this friction, and clean aluminum comes close to each other, and the two are bonded by atomic bonding and diffusion bonding. Ultrasonic welding is performed by the above operation.

As described above, in the present embodiment, the surface in contact with the workpiece is coated with diamond-like carbon and subjected to ultrasonic welding. Since ceramics such as diamond-like carbon are nonmetals, various problems caused by sticking to metal and other objects to be welded, that is, (1) when sticking occurs, the object to be welded adheres to the horn tip or anvil. Therefore, it is time-consuming to remove it, and (2) it is possible to solve the problem that the workpiece is deformed or damaged because a part of the workpiece adheres to the horn tip or the anvil. Can be.

Further, since ceramics having high hardness have little wear, it is possible to stably perform ultrasonic welding for a long period of time.

In this embodiment, diamond-like carbon is coated. This is because diamond-like carbon can be coated at a temperature of about 400 ° C., so that there is no possibility of melting the quenched portion of the horn or anvil. However, depending on the material of the horn or the anvil, ceramics such as chromium nitride may be used.

In this embodiment, the horn cantilever type ultrasonic welding apparatus is shown, but a horn double-sided ultrasonic welding apparatus may be used. In this case, the life of the horn is prolonged because the deflection amount of the horn is smaller than that of the cantilever method.

In addition, the present invention is not limited to the present embodiment, but can be variously modified for the same purpose.

(Second Embodiment) A second embodiment relates to an ultrasonic welding apparatus according to the present invention.

The configuration of the ultrasonic welding device will be described.

The ultrasonic welding apparatus presses the object to be welded between the ultrasonic actuator 1, the horn 2 connected to the ultrasonic actuator 1, the anvil 6, and the horn 2 and the anvil 6. And a pressurizing mechanism 5.

What is different from the first embodiment is the shape of the anvil 6.

The components other than the anvil 6 have the same functions as those of the first embodiment, and therefore the description is omitted.

The shape of the anvil 6 is such that the workpiece 7 is restrained in the direction of ultrasonic vibration by being fitted to the anvil 6.

The shape of the workpiece 7 is a disk having a recess at the center as shown in FIG. Therefore, the shape of the anvil 6 has a convex portion in the center as shown in FIG. 5 and the convex portion is fitted with the concave portion of the workpiece 7 to thereby bring the workpiece 7 into the ultrasonic vibration direction. Can be restrained. The surface of the anvil 6 is coated with diamond-like carbon.

The operation of ultrasonic welding based on the above configuration will be described.

First, the workpiece 8 and the workpiece 7 will be described.

The work 8 to be directly contacted with the horn tip 3
Is a disk shape with a diameter of about 4 mm and a thickness of less than 1 mm,
The material is aluminum.

The workpiece 7 in direct contact with the anvil 6 has a diameter of about 8 mm and a thickness of 1 m, as shown in FIG.
It has a disk shape of less than m. At the center of the workpiece 7,
A conical protrusion having a diameter of about 1 mm is formed. A recess is formed at the center of the surface opposite to the surface having the projection.

The recess of the workpiece 7 is fitted to the projection of the anvil 6. Next, the workpiece 8 is placed on the workpiece 7 such that the projection of the workpiece 7 is in contact with the center of the workpiece 8.

Then, the pressing mechanism 5 is operated to bring the pressing surface 4 of the horn tip 3 into contact with the work 8,
And the workpiece 7 are sandwiched between the horn tip 3 and the anvil 6.

Thereafter, the ultrasonic actuator 1 is operated. The horn tip 3 reciprocates in the vertical direction of the pinching direction in conjunction with the reciprocation of the ultrasonic actuator 1.

The operation on the contact surface between the horn tip 3 and the workpiece 8, the contact surface between the workpiece 8 and the workpiece 7, and the contact surface between the workpiece 7 and the anvil 6 are described below with reference to FIG.
This will be described with reference to FIG.

At the contact surface between the horn tip 3 and the workpiece 8, the convex portion on the surface of the pressurizing surface 4 bites into the workpiece 8 due to the pressure of the pressing mechanism 5. Due to this biting, the workpiece 8 reciprocates in conjunction with the reciprocation of the horn tip 3.

Since the pressing surface 4 is coated with diamond-like carbon, there is no possibility that the workpiece 8 made of aluminum adheres to the convex portion of the pressing surface 4.

Next, the contact surface between the workpiece 7 and the workpiece 8 will be described.

While the workpiece 8 reciprocates, the workpiece 7 is substantially stationary as described later. For this reason, both rub. Due to this friction, the two are ultrasonically welded by the same operation as in the first embodiment.

Next, the contact surface between the workpiece 7 and the anvil 6 will be described.

First, the fact that the workpiece 7 is substantially stationary will be described. Regarding the direction of the reciprocating motion of the horn tip 3, the concave portion of the workpiece 7 and the convex portion of the anvil 6 are restrained by fitting. Further, in the direction perpendicular to this direction, the horn tip 3 is restrained by the pinch between the horn tip 3 and the anvil. Therefore, the workpiece 7 is almost stationary.

However, the fitting between the concave portion of the workpiece 7 and the convex portion of the anvil 6 may be loose fit.
In such a case, since there is friction at the contact surface between the workpiece 7 and the anvil 6, a sticking phenomenon may occur. However, since the surface of the convex portion of the anvil 6 is coated with diamond-like carbon, which is a ceramic, sticking does not occur due to such friction, and ultrasonic welding is performed normally.

As described above, by using the ultrasonic welding apparatus in which the horn tip 3 and the anvil 6 are coated with diamond-like carbon, the sticking phenomenon that aluminum or the like to be welded adheres to the surface of the horn or the anvil is prevented. can do.

In addition, since there is no fear of scratches or poor welding due to sticking of the workpiece, ultrasonic welding can be performed without damaging the workpiece.

Further, as in the first embodiment, if the movement of the workpiece is restricted by forming fine irregularities on the contact surface of the anvil, the anvil bites into the workpiece, thereby damaging the workpiece. Would. However, in the case of this embodiment,
The shape of the anvil was made to fit with the work to be welded, and the movement of the work to be welded was restrained by this fitting.
Therefore, ultrasonic welding can be performed without damaging the shape of the workpiece.

As described above, it has become possible to perform ultrasonic welding for preventing sticking without impairing the shape of the workpiece.

As shown in FIG. 6, the horn shape may be formed so as to be fitted to the workpiece. In this case, ultrasonic welding can be performed without impairing the shapes of both workpieces.

The shape of the workpiece is not limited to the present embodiment. For example, as shown in FIG. 7, in a workpiece having a shape having convex portions at a plurality of locations,
The work to be welded is supported as an anvil that fits into the work to be welded. Alternatively, as shown in FIG. 8, if the workpiece has a shape including a plurality of planes, the workpiece is supported in an anvil shape so as to be fitted with the workpiece.

In addition, the present invention is not limited to the present embodiment, but can be variously modified for the same purpose.

(Third Embodiment) A third embodiment is directed to
The present invention relates to a battery obtained by welding the rupture disk 10 and the conductive plate 20 using the ultrasonic welding apparatus described in the first embodiment, and a method for manufacturing the battery. First, the configuration of the battery will be described, and then a method of manufacturing the battery will be described.

First, the structure of the battery will be described with reference to FIG. For example, a lithium ion secondary battery includes a cylindrical outer can housing 17 having an opening on the upper surface, and a lid 18 attached to the opening so as to substantially close the opening.
A power generator 11 formed by spirally winding a thin plate-like positive electrode 12 and negative electrode 14 with a separator 13 interposed therebetween is provided inside the outer can housing 17 and is not shown. The electrolyte is filled.

At the bottom of the outer can housing 17, an insulating sheet 21 and a negative electrode tab 16 connected to the negative electrode 14 of the power generating element are provided.

On the other hand, the lid 18 serving as the positive electrode terminal has a disk shape, and is in contact with the rupture disk 10 at the peripheral edge. The rupture disk 10 is a rupture disk, which is in contact with the lid 18 at the peripheral edge, forms a convex portion at the center, and is ultrasonically welded to the conductive plate 20 at the convex portion. Current plate 20
Has a thin disk shape of aluminum, is joined to the rupture disk 10 at the center, and is joined to the positive electrode tab 15 on the back surface. The energizing plate 20 is provided with a spacer 22
Thus, the movement in the direction of the lid 18 is restricted. The other end of the positive electrode tab 15 is connected to the positive electrode of the power generator 11. Next, a method for manufacturing such a lithium ion secondary battery will be described.

First, the rupture disk 10 and the energizing plate 20
Will be described. The configuration of the ultrasonic welding device is the same as that of the first embodiment. The aluminum rupture disk 10 has a disk shape with a diameter of less than 10 mm, and has a convex portion at the center. The current-carrying plate has a diameter of 5
It is a disk shape of aluminum of about millimeter. As in the first embodiment, after the current-carrying plate 20 is placed so as to face the rupture disk 7 fitted to the anvil 6, the horn tip 3 presses the plate from above. Horn tip 3
The pressing surface 4 has an uneven surface. This horn tip 3
However, since the current-carrying plate 20 is pressed in the vertical direction and reciprocates with an amplitude of about several tens of microns in the horizontal direction, ultrasonic welding is performed on the contact surface between the current-carrying plate 20 and the rupture disk 10.

A lithium ion secondary battery is manufactured using the current-carrying plate 20 and the rupture disk 10 welded in the above-described ultrasonic welding process.

As shown in FIG. 11, a power generating element 11 as a power generating element includes a positive electrode 12 which is an aluminum thin film coated with an active material containing a carbonaceous material on both front and rear surfaces, and a separator which is a porous polypropylene sheet. 13 and a negative electrode 14, which is a copper thin film coated with an active material containing lithium nickel oxide, lithium cobalt oxide, etc., on both front and back surfaces thereof, is spirally wound so that the negative electrode is arranged on the outermost periphery. It is created through the following steps. Next, a rectangular tabular aluminum positive electrode tab 15 is ultrasonically welded to the positive electrode 12 of the power generator 11, and a nickel negative electrode tab 16 is ultrasonically welded to the negative electrode 13 of the electrode body 11. Then, FIG.
As shown in FIG. 3, the power generator 11 is attached to a negative electrode tab 16 in a cylindrical outer case 17 made of iron and open at the top.
Into contact with the bottom surface of the outer can housing 17. Thereafter, the negative electrode tab 16 and the bottom surface of the outer can housing 17 are electrically connected by spot welding.

On the other hand, the other end of the positive electrode tab 15 ultrasonically welded to the positive electrode 12 of the power generator 11 extends upward from the opening of the outer can housing 17 as shown in FIG. And the rupture disk 1 in the ultrasonic welding process.
The laser welding is performed between 0 and the welded current-carrying plate 20 as shown in FIG. After the electrolytic solution is injected into the outer can housing 17, the lid 18 is fitted into the opening, and the outer can housing 17 is hermetically sealed with a sealant 19 or the like. Through the above steps, a lithium ion secondary battery is manufactured. A cross-sectional view of the completed lithium ion secondary battery is shown in FIG.

[0093] The lithium ion secondary battery manufactured in this way is characterized by the action of the rupture disk 10 during overvoltage. Therefore, the operation of the rupture disk 10 at the time of overvoltage will be described below with reference to FIG.

At the time of an overvoltage, an abnormal gas is generated inside the outer casing 17, so that the internal pressure increases. At this time, the rupture disk 10 undergoes plastic deformation due to the internal pressure and is pushed toward the lid 18. On the other hand, the movement of the rupture disk 10 in the direction of the lid 18 is restricted by the spacer 22. Therefore, rupture disk 1
0 and the welding portion of the current-carrying plate 20 are separated to interrupt the electrical conduction. For this reason, generation of gas is suppressed, and ejection of gas to the outside of the battery is prevented.

In the present invention, since the sticking phenomenon is suppressed, the operation reliability of the safety valve is improved, and the yield can be improved. The present invention is not limited to the present embodiment, and can be modified in other sealed batteries having a safety valve.

[0096]

By using a horn or anvil coated with ceramics, it is possible to provide an ultrasonic welding apparatus and an ultrasonic welding method in which the sticking phenomenon is prevented. Further, by welding the rupture disk and the current-carrying plate using this ultrasonic welding method, a sealed battery having a safety valve that operates more accurately than in the past, and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic welding apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram of a horn tip of the ultrasonic welding device according to the first embodiment of the present invention.

FIG. 3 is a diagram of an anvil of the ultrasonic welding device according to the first embodiment of the present invention.

FIG. 4 is a view of a rupture disk as a work to be welded according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an operation of ultrasonic welding according to the first embodiment of the present invention.

FIG. 6 is a diagram of a modification of the first embodiment of the present invention.

FIG. 7 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 8 is a diagram of a modification of the first embodiment of the present invention.

FIG. 9 is a configuration diagram of ultrasonic welding according to a second embodiment of the present invention.

FIG. 10 is a configuration diagram of a lithium ion secondary battery according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a power generator according to a third embodiment of the present invention.

FIG. 12 is a diagram in which an electrode body according to a third embodiment of the present invention is inserted into an outer can housing.

FIG. 13 is a view showing a state where a current carrying plate and a positive electrode tab are laser-welded in the third embodiment of the present invention.

FIG. 14 is a view showing the operation of the safety valve of the lithium ion secondary battery according to the third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic actuator 2 Horn 3 Horn tip 5 Pressurization mechanism 6 Anvil 10 Rupture disk 20 Current plate

[Procedure amendment]

[Submission date] January 28, 2000 (2000.1.2
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

[0001] The present invention relates to an ultrasonic welding apparatus, an ultrasonic welding method, a sealed battery, and a method of manufacturing the same.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B06B 1/02 B06B 1/02 K 5H029 B23K 103: 10 B23K 103: 10 F term (Reference) 4E067 AA05 BF00 BF04 CA01 EB00 5D107 AA14 BB01 FF03 5H022 AA09 BB11 CC08 EE01 EE04 EE05 KK01 5H024 AA01 AA02 BB05 BB08 BB14 BB19 CC02 CC12 DD02 DD11 EE01 EE05 HH17 5H028 AA07 BB01 B03 BB01 A03 BB01 A03 BB01 CJ13 CJ30 DJ02 EJ01 EJ08 HJ15

Claims (9)

[Claims] 1. An anvil that supports an object to be welded, a horn that squeezes the object to be welded with the anvil, and reciprocates in a direction substantially perpendicular to the direction of the squeezing; An ultrasonic welding device comprising: a sound wave actuator; and a pressing mechanism that presses the workpiece with the horn and the anvil. A contact surface of the horn with the workpiece, or the coating of the anvil. An ultrasonic welding device, characterized in that at least one of a contact surface with a welded object is formed of ceramics. 2. An anvil for supporting an object to be welded, a horn for nipping the object to be welded against the anvil, and reciprocating in a direction substantially perpendicular to the direction of the pressure, An ultrasonic welding device comprising: a sound wave actuator; and a pressing mechanism that presses the workpiece with the horn and the anvil. A contact surface of the horn with the workpiece, or the coating of the anvil. An ultrasonic welding apparatus, wherein at least one of a contact surface with a welded object is formed of diamond-like carbon. 3. The ultrasonic welding apparatus according to claim 1, wherein the anvil can be supported such that movement in a direction substantially perpendicular to the pinching direction is restrained by fitting with the workpiece. An ultrasonic welding apparatus characterized in that the anvil has a special shape. 4. An ultrasonic welding method in which two members are pressed between a horn and an anvil, and the horn is reciprocated in a direction substantially perpendicular to the pressing direction to ultrasonically weld the two members. An ultrasonic wave, wherein either or both of the horn and the anvil have a contact surface with the member formed of ceramics, and press the member through the contact surface. Welding method. 5. An ultrasonic welding method for sandwiching two members between a horn and an anvil and reciprocating the horn in a direction substantially perpendicular to the direction of the sandwiching, thereby ultrasonically welding the two members. , Wherein either or both of the horn and the anvil have a contact surface with the member made of diamond-like carbon, and press the member through the contact surface. Ultrasonic welding method. 6. The ultrasonic welding method according to claim 4, wherein the other member is superimposed in a state in which the movement in the direction substantially perpendicular to the pinching direction is restrained by fitting with the anvil. Ultrasonic welding, an ultrasonic welding method. 7. The ultrasonic welding method according to claim 4, wherein the ceramic is a ceramic containing chromium nitride or titanium nitride as a main component. 8. An insertion step of inserting a power generation element having a positive electrode and a negative electrode opposed to each other with a separator therebetween into an outer can housing having an opening; and attaching the negative electrode or the positive electrode to a bottom surface of the outer can housing. A connection step of electrically connecting the battery pack with the battery, after the connection step, a step of injecting an electrolytic solution into the exterior can housing, and the shape changes when the pressure inside the exterior can housing reaches a predetermined value. An ultrasonic welding step of welding a rupture disk and a metal plate extending from the negative electrode or the positive electrode by ultrasonic welding so that a portion to be welded is separated and electrical conduction is interrupted. A method of electrically connecting the rupture disk and a lid; and a step of closing the opening using the lid to seal the outer can housing. In the ultrasonic melting, The contacting step is characterized in that the metal plate and the rupture disk are ultrasonically welded to each other by using an anvil made of ceramics and having a contact surface with the rupture disk, the shape being fitted to the rupture disk. Manufacturing method of sealed battery. 9. An outer can housing having an opening, a power generating element inside the outer can housing and having a positive electrode and a negative electrode facing each other with a separator interposed therebetween, the positive electrode or the negative electrode, and the outer can housing First connecting means for electrically connecting a body bottom surface; a lid for covering the opening of the outer can housing; a second electrode for electrically connecting the positive electrode or the negative electrode to the lid; A connecting means, provided between the first connecting means or the second connecting means, and connected to the first or second connecting means by ultrasonic welding; When the pressure inside the body reaches a predetermined value, the electrical continuity is interrupted,
A sealed battery comprising: a rupture disk made of aluminum; and an electrolyte injected into the exterior can housing, wherein the ultrasonic welding is supported by an anvil whose contact surface with the rupture disk is made of ceramics. A sealed battery characterized by being ultrasonically welded to the first or second connection means.