Patent Description:
As the demands for portable electronic products such as notebooks, video cameras and cellular phones are rapidly increased in these days, and development of electric vehicles, energy storage batteries, robots, satellites, etc. is under active progress, numerous studies are being made on secondary batteries being used as the driving power source.

The electrode assembly mounted in the battery case is a power generating element, having a cathode/separator/anode stack structure, which can be charged and discharged, and the electrode assembly is classified into a jelly-roll type, a stacked type and a stacked/folded type. The jelly-roll type electrode assembly is configured to have a structure in which a long sheet type cathode and a long sheet type anode, to which active materials are applied, are wound in a state where a separator is interposed between the cathode and the anode, the stacked type electrode assembly is configured to have a structure in which a large number of cathodes having a predetermined size and a large number of anodes having a predetermined size are sequentially stacked in a state in which separators are interposed between the cathodes and the anodes, and the stacked/folded type electrode assembly is a combination of the jelly-roll type electrode assembly and the stacked type electrode assembly. Among them, the jelly-roll type electrode assembly has advantages in that manufacturing is easy and an energy density per unit weight is high.

Based on the shape of a battery case, a secondary battery is classified into a cylindrical battery where an electrode assembly is mounted in a cylindrical metal can, a prismatic battery where an electrode assembly is mounted in a prismatic metal can, and a pouch-shaped battery where an electrode assembly is mounted in a pouch-shaped case formed of an aluminum laminate sheet.

When manufacturing such various types of secondary batteries, parts may be combined using a welding apparatus. In a conventional welding apparatus, a welding rod is exposed to the outside and heat generated during welding is not controlled, so the welding rod is prepared in an overheated state before the progress of a next welding. Thus, there is a possibility that the electrode or separator of the welding part may be damaged.

In addition, in the conventional welding apparatus, the upper welding rod is not provided with a temperature measuring mechanism, and resistance fluctuates when the temperature of the welding rod changes, which makes it difficult to apply a uniform current. Even if the temperature is measured, the movement speed of the equipment is fast and the outer diameter of the welding rod is relatively small, which caused a problem that it was difficult to measure the temperature of the upper welding rod.

<CIT> (disclosing the preamble of claims <NUM> and <NUM>) describes an extremely small wire in a resistance welding apparatus which performs a thermocompression bonding or a spot welding.

<CIT> relates to a system and method for monitoring alignment, pressure, and temperature of electrodes of a welder.

It is an object of the present invention to provide a welding apparatus and a welding method that manage a heat of welding rods generated when welding secondary batteries and minimize welding defects.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a welding apparatus as defined in claim <NUM>, comprising: a welding rod; a temperature measuring jig section that measures the temperature of the welding rod; and a welding rod cooler section that cools the welding rod.

The temperature measuring jig section includes a main body portion; a temperature sensor positioned at the upper end of the main body portion; and a rotating shaft portion that rotates the main body portion to position the temperature sensor at the lower end part of the welding rod.

The rotating shaft portion may be formed on the main body portion, and rotate the main body portion in a horizontal direction around the rotating shaft portion.

The rotating shaft portion may rotate the main body portion between <NUM> degrees and <NUM> degrees.

The welding rod is formed of an upper welding rod and a lower welding rod, and the temperature sensor may come into close contact with the lower end of the upper welding rod through rotation to measure the temperature of the upper welding rod.

The welding rod cooler section includes a cooling panel; and a plurality of cooling holes formed in the cooling panel, wherein the cooling hole is connected to a blower, and a cold air flowing-in through the blower may passe through the cooling hole to be blown to the welding rod.

The cooling panel is formed in a shape curved toward the lower end part of the upper welding rod, so that the cold air may be blown to the lower end of the upper welding rod.

The plurality of cooling holes may be formed into <NUM> or less.

In order to achieve the above object, according to a second aspect of the present invention, there is provided a welding method as defined in claim <NUM>, comprising: a step in which a temperature measuring jig section comes into close contact with the lower end of an upper welding rod to measure the temperature of the lower end of the upper welding rod; a step in which the temperature measuring jig section is detached from the lower end of the upper welding rod through rotation; a step in which the upper welding rod is moved in a direction in which the lower welding rod is positioned to perform a welding process; a step in which the upper welding rod is returned to the upper side after the welding process has been completed; and a step in which the temperature measuring jig section comes into close contact with the lower end of the upper welding rod through rotation to measure the temperature of the lower end of the upper welding rod again.

The welding method further includes a step in which the welding rod cooler section cools the lower end part of the upper welding rod.

It should be appreciated that the exemplary embodiments, which will be described below, are illustratively described to assist in the understand the present disclosure, and the present disclosure can be variously modified to be carried out differently from the exemplary embodiments described herein. However, in the description of the present disclosure, the specific descriptions and illustrations of publicly known functions or constituent elements will be omitted when it is determined that the specific descriptions and illustrations may unnecessarily obscure the subject matter of the present disclosure. In addition, in order to help understand the present disclosure, the accompanying drawings are not illustrated based on actual scales, but parts of the constituent elements may be exaggerated in size.

As used herein, terms such as first, second, and the like may be used to describe various components, and the components are not limited by the terms. The terms are used only to discriminate one component from another component.

Further, the terms used herein are used only to describe specific exemplary embodiments, and are not intended to limit the scope of the present disclosure. A singular expression includes a plural expression unless they have definitely opposite meanings in the context. It should be understood that the terms "comprise", "include", and "have" as used herein are intended to designate the presence of stated features, numbers, steps, movements, constitutional elements, parts or combinations thereof, but it should be understood that they do not preclude a possibility of existence or addition of one or more other features, numbers, steps, movements, constitutional elements, parts or combinations thereof.

Below, the structure of a welding apparatus according to one embodiment of the present disclosure will be described with reference to <FIG>.

<FIG> is a diagram showing a welding apparatus according to one embodiment of the present disclosure.

Referring to <FIG>, the welding apparatus according to the present embodiment includes a welding rod <NUM>, a temperature measuring jig section that measures the temperature of the welding rod <NUM>, and a welding rod cooler section <NUM> that cools the welding rod <NUM>. The welding rod <NUM> includes an upper welding rod <NUM> and a lower welding rod <NUM>, and a welding process can be performed between the upper welding rod <NUM> and the lower welding rod <NUM>. The welding rod <NUM> described later may refer to the upper welding rod <NUM>.

The temperature measuring jig section <NUM> includes a main body portion <NUM> formed in a bar shape, a temperature sensor <NUM> that is positioned at the upper end of the main body portion <NUM>, and a rotating shaft portion <NUM> that rotates the main body portion <NUM> to position the temperature sensor <NUM> at the lower end of the welding rod <NUM>. The temperature of the lower end of the welding rod <NUM> can be measured through the temperature sensor <NUM> positioned in the temperature measuring jig section <NUM>.

The conventional welding apparatus was not provided with a temperature sensor, so there was a problem that resistance fluctuates when the temperature of the welding rod changes, which makes it difficult to apply a uniform current to the welding rod. Further, even if the temperature sensor is provided, there was a problem that the outer diameter of the upper welding rod is relatively smaller than that of the lower welding rod, and thus it is difficult to accurately measure the temperature of the lower end part of the upper welding rod. Further, the production speed can be increased by using a plurality of welding rods in a general battery production process, but it was necessary to maintain a uniform temperature of the plurality of welding rods and realize uniform welding quality for each welding section.

On the other hand, according to the present embodiment, the temperature of the lower end part of the welding rod <NUM> is measured by using the temperature sensor <NUM> positioned at the upper end of the main body <NUM>, and the temperature of the welding rod is adjusted through the measured temperature, thereby capable of ensuring the uniformity of welding quality welding.

According to the present embodiment, the welding rod cooler section <NUM> includes a cooling panel <NUM> and a plurality of cooling holes <NUM> formed in the cooling panel <NUM>, and a blower <NUM>, and the cooling holes <NUM> is connected to a blower <NUM>, and the cold air flowing-in through the blower <NUM> passes through the cooling holes <NUM> to be blown to the lower end of the welding rod <NUM>.

In the conventional welding apparatus, a separate cooling means for the welding rod was not existed, and an air conditioner type blower was used, but in the case of an air conditioner type blower, there was a problem in that it was difficult to intensively cool at a desired position. Further, since the welding cycle is repeated rapidly in the battery production process, rapid cooling of the welding rod was sometimes required. According to this embodiment, the welding cycle can be proceeded at a speed at which one cycle circulates within one second.

In this regard, according to the present embodiment, a plurality of cooling holes <NUM> formed in the cooling panel <NUM> formed so as to have a curvature toward the lower end of the welding rod <NUM> are connected to the blower <NUM>, and the cold air flowing-in through the blower <NUM> passes through the cooling hole <NUM> formed toward the lower end of the welding rod <NUM> and is intensively blown to the lower end part of the welding rod where heat generation is relatively intense, thereby rapidly cooling the welding rod and improving the welding efficiency.

Below, the operation of the temperature measuring jig section and the welding rod cooler section according to the present disclosure will be described with reference to <FIG>.

<FIG> is a diagram showing a state in which the temperature measuring jig section according to the present disclosure enters the lower end of the upper welding rod where welding has been completed, and measures the temperature of the upper welding rod. <FIG> is a diagram showing a state in which the temperature measurement jig section according to one embodiment of the present disclosure completes the temperature measurement and detaches the lower end part of the upper welding rod, and then the upper welding rod proceeds the welding again.

Referring to <FIG>, in the temperature measuring jig section <NUM> according to the present embodiment, the rotating shaft portion <NUM> is formed on the main body portion <NUM> and can rotate the main body portion <NUM> in a horizontal direction around the rotating shaft portion <NUM>. The rotating shaft portion <NUM> may be fixed to a specific position outside the welding apparatus. At this time, the rotating shaft portion <NUM> can rotate the main body portion <NUM> between <NUM> degrees and <NUM> degrees. When the rotation of the main body portion <NUM> exceeds <NUM> degrees, the main body portion <NUM>, which was spaced apart, requires a relatively large amount of power to return to the lower end part of the upper welding rod for temperature measurement, and therefore, the rotation angle of the main body portion <NUM> is preferably formed within <NUM> degrees. Further, when temperature measurement is not performed, it is preferable that the rotation angle of the main body portion <NUM> is rotated at an angle that can be spaced apart from the welding rod <NUM> at least to thereby maintain an angle at which the main body portion <NUM> and the temperature measuring jig section <NUM> are positioned so as to be spaced apart from each other.

A temperature sensor <NUM> is mounted on the upper surface of the end of the main body portion <NUM>, and the temperature sensor <NUM> can come into close contact with the lower end part of the welding rod <NUM> through rotation to measure the temperature of the welding rod <NUM>.

Therefore, when the welding rod <NUM> performs welding, the end part of the main body portion <NUM> around the rotating shaft <NUM> is positioned at a position spaced apart from the lower end part of the welding rod <NUM>. When the upper welding rod <NUM> is spaced apart from the lower welding rod <NUM> after welding has been completed, as shown in <FIG>, the temperature sensor <NUM> mounted on the end part of the main body portion may be positioned at the lower end part of the upper welding rod <NUM> by rotating the main body portion <NUM> around the rotating shaft <NUM>. Further, after the temperature measurement has been completed through the temperature sensor <NUM>, as shown in <FIG>, the main body portion <NUM> is rotated in the outer direction of the welding rod around the rotating shaft portion <NUM> again, so that the main body portion <NUM> is positioned at a position spaced apart from the welding rod <NUM>. The above-described rotating step of the main body portion <NUM> may be repeatedly performed in proportion to the number of repeated welding progress.

At this time, the temperature sensor <NUM> may be positioned so as to be in contact with the lower end part of the upper welding rod <NUM>. Therefore, the rotating shaft part <NUM> and the main body portion <NUM> may be positioned on the same horizontal plane as the portion where the lower end part of the upper welding rod <NUM> is positioned when welding is not performed.

According to the present embodiment, the rotation of the main body portion <NUM> via the rotation shaft portion <NUM> rotates in a direction perpendicular to the longitudinal direction of the welding rod <NUM>, so that the interference between the welding rod <NUM> and the temperature measuring jig section <NUM> can be minimized.

The cooling panel <NUM> constituting the welding rod cooler section <NUM> may be formed in a shape curved toward the lower end part of the welding rod <NUM>. The cooling panel <NUM> may be formed so as to have a constant radius of curvature R. At this time, the radius of curvature (R) can be adjusted according to the type of the welding rod to adjust the curved angle of the cooling panel <NUM>. Through this, the curved angle of the cooling panel <NUM> can be adjusted to suit the types of welding rods having various sizes and shapes, so that the cool air guided from the cooling hole <NUM> formed on the curved surface of the cooling panel <NUM> may be intensively blown to the portion where heat generation is intense.

According to the present embodiment, the plurality of cooling holes <NUM> may be formed into <NUM> or less. When the number of cooling holes <NUM> formed in the cooling panel <NUM> exceeds <NUM>, interference between cold airs blown through the cooling hole <NUM> occurs, and cooling of the lower end part of the welding rod <NUM> cannot be performed properly. Thus, the number of the cooling holes <NUM> is preferably formed to be <NUM> or less.

Below, a welding method according to one embodiment of the present disclosure will be described with reference to <FIG>.

Referring to <FIG>, in the welding method according to this embodiment, a step in which a temperature measuring jig section <NUM> comes into close contact with the lower end of an upper welding rod <NUM> to measure the temperature of the lower end of the upper welding rod <NUM>, a step in which the temperature measuring jig section <NUM> is detached from the lower end of the upper welding rod <NUM> through rotation, a step in which the upper welding rod <NUM> is moved in a direction in which the lower welding rod <NUM> is positioned to perform a welding process, a step in which the upper welding rod <NUM> is returned to the upper side after the welding process has been completed; and a step in which the temperature measuring jig section <NUM> comes into close contact with the lower end of the upper welding rod <NUM> through rotation to measure the temperature of the lower end of the upper welding rod <NUM> again, can be sequentially carried out.

As described above, the temperature sensor <NUM> is periodically positioned at the lower end part of the upper welding rod <NUM> via the repeated rotational movement of the main body portion <NUM>, whereby the temperature at the lower end part of the upper welding rod, which can change between repeated welding processes, can be repeatedly measured, so that the temperature of the welding rod can be controlled more precisely, and the welding quality can be improved.

According to the present embodiment, in each step of the above-described welding method, a step in which the welding rod cooler section <NUM> cools the lower end part of the upper welding rod <NUM> can be further included. Therefore, the welding process cycle is repeatedly performed, and thus the temperature measurement associated therewith s periodically performed. At the same time, the lower end part of the upper welding rod <NUM> is continuously cooled through the welding rod cooler section <NUM>, thereby improving overall welding quality.

Although the present invention has been shown and described with reference to preferred embodiments, the scope of the present invention is not limited thereto, and numerous other modifications and embodiments can be devised by those skilled in the art, without deviating from the scope of the present invention as defined in the appended claims.

Claim 1:
A welding apparatus comprising:
a welding rod (<NUM>);
a welding rod cooler section (<NUM>) that cools the welding rod;
the welding apparatus being characterised by the following:
a temperature measuring jig section (<NUM>) that measures the temperature of the welding rod (<NUM>); and
wherein:
the temperature measuring jig section (<NUM>) comprises
a main body portion (<NUM>);
a temperature sensor (<NUM>) positioned at the upper end of the main body portion (<NUM>); and
a rotating shaft portion (<NUM>) that rotates the main body portion (<NUM>) to position the temperature sensor (<NUM>) at the lower end part of the welding rod (<NUM>), and
the welding rod cooler section (<NUM>) comprises
a cooling panel (<NUM>); and
a plurality of cooling holes (<NUM>) formed in the cooling panel (<NUM>),
a blower (<NUM>),
wherein the cooling holes (<NUM>) are connected to the blower (<NUM>), and a cold air flowing-in through the blower (<NUM>) passes through the cooling hole (<NUM>) to be blown to the welding rod (<NUM>).