Patent Description:
The present invention relates to a battery module assembly apparatus using vision and an assembly method using the same, and more particularly to a battery module assembly apparatus using vision capable of accurately recognizing the position at which a battery cell and a busbar will be electrically connected to each other and minimizing poor contact therebetween due to foreign matter at the time of electrical connection therebetween and an assembly method using the same.

A secondary battery, which has high ease of application based on product family and electrical characteristics, such as high energy density, has been universally applied to an electric vehicle (EV) or a hybrid electric vehicle (HEV) driven by an electrical driving source as well as portable devices. Such a secondary battery has attracted attention as a new energy source capable of enhancing environmental friendliness and energy efficiency in that the secondary battery has a primary advantage of remarkably reducing the use of fossil fuels and in that no by-products due to the use of energy are generated.

There are a lithium-ion battery, a lithium polymer battery, a nickel-cadmium battery, a nickel-hydride battery, and a nickel-zinc battery as secondary batteries that are widely used at present. The operating voltage of such a unit secondary battery cell, i.e. a unit battery cell, is about <NUM>. 5V to <NUM>. In the case in which output voltage higher than the above operating voltage is required, therefore, a plurality of battery cells may be connected to each other in series to constitute a battery module.

Of course, a plurality of battery modules may be connected to each other in parallel or in series depending on required charge and discharge capacities to constitute a battery pack.

Meanwhile, in order to satisfy required output voltage, a plurality of cylindrical battery cells is received in a battery module, and the battery cells are connected to each other via a busbar in order to increase energy density. For the cylindrical battery cell, however, a positive electrode and a negative electrode are located very close to each other, and the areas of portions having corresponding polarities are small, whereby connection between the cylindrical battery cell and the busbar is not easily achieved.

In connection therewith, <FIG> is a view showing an apparatus for bonding a conventional battery cell. Referring to <FIG>, a battery module assembly apparatus includes a supply unit configured to supply a battery module to the apparatus, a transfer unit configured to transfer the supplied battery module to a work position, a vision type camera configured to scan the transferred battery module, and a welding unit configured to bond the battery module. The battery module transferred by the transfer unit is scanned through the vision type camera to set coordinates and is moved to the position of the welding unit based on the information such that bonding is performed by the welding unit.

In the conventional art, a bonding position is set using the vision type camera, and then bonding is performed. Since there is no light source configured to illuminate the battery module, however, it is difficult to accurately recognize the position of the battery module. In particular, there is a possibility of the battery module being contaminated by various kinds of foreign matter, such as dust, until the battery module reaches the welding unit, whereby welding defects may occur.

Document <CIT> discloses a battery module assembling equipment of known type.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery module assembly apparatus using vision capable of accurately scanning the positions of a module case and a battery cell received in the module case such that the battery cell can be bonded to a busbar at a predetermined position and an assembly method using the same.

It is another object of the present invention to provide a battery module assembly apparatus using vision capable of removing foreign matter attached to the region of the battery cell to be bonded, thereby minimizing bonding defects, and an assembly method using the same.

In order to accomplish the above objects, a battery module assembly apparatus as defined in the appended claims is provided.

In addition, an assembly method is also provided.

A battery module assembly apparatus using vision according to the present invention and an assembly method using the same have a merit in that a plurality of vision units scans a battery module, and a cylindrical battery cell and a busbar are bonded to each other based on the result, whereby it is possible to perform bonding at a correct position.

In addition, the battery module assembly apparatus using vision according to the present invention and the assembly method using the same have an advantage in that a washing unit configured to wash only a portion to be bonded is provided, whereby it is possible to minimize bonding defects due to foreign matter.

Furthermore, the battery module assembly apparatus using vision according to the present invention and the assembly method using the same have a merit in that an illumination portion having high illuminance is provided, whereby it is possible to improve reliability in result of scanning by a vision camera.

Hereinafter, a battery module assembly apparatus using vision according to the present invention and an assembly method using the same will be described with reference to the accompanying drawings.

<FIG> is a perspective view showing a battery module according to a preferred embodiment of the present invention, and <FIG> is a sectional view of a cylindrical battery cell according to a preferred embodiment of the present invention.

Referring to <FIG> and <FIG>, the battery module <NUM> according to the present invention includes a module case <NUM>, a cylindrical battery cell <NUM>, a busbar <NUM>, and a cover case <NUM>.

The module case <NUM>, which has a hexahedral outer shape, is provided with a space configured to receive the cylindrical battery cell <NUM>, and a plurality of openings (not shown), through which terminals of the cylindrical battery cell <NUM> are exposed to the outside in a state in which the cylindrical battery cell is upright, is formed in the upper end of the module case <NUM>.

Meanwhile, as shown in <FIG>, a battery cell received in the battery module according to the present invention is a cylindrical battery cell <NUM>, which may be manufactured by receiving an electrode assembly <NUM> having a wound type structure in a metal can <NUM>, injecting an electrolytic solution into the metal can <NUM>, and coupling a cap assembly <NUM> having an electrode terminal formed thereon to the open upper end of the metal can <NUM>.

Here, the electrode assembly <NUM> is manufactured by sequentially stacking a positive electrode <NUM>(a), a negative electrode <NUM>(b), and a separator <NUM>(c) and winding the same in a round shape.

A cylindrical center pin <NUM> is inserted into a hollow core portion <NUM> formed in a central region of the electrode assembly <NUM>. The center pin <NUM> is generally made of a metal material in order to provide predetermined strength. The center pin <NUM> serves to fix and support the electrode assembly <NUM>, and serves as a path configured to discharge gas generated due to internal reaction when the battery cell is charged and discharged and is operated.

Meanwhile, a positive electrode terminal <NUM>(a) is formed so as to have a protruding shape at a middle region of the upper end of the cap assembly <NUM>, and the remaining region of the cap assembly <NUM> constitutes a negative electrode terminal <NUM>(b).

Of course, the cylindrical battery cell <NUM> is not particularly restricted as long as the positive electrode terminal <NUM>(a) and the negative electrode terminal <NUM>(b) are exposed or protrude from the upper end of the cap assembly <NUM>.

The busbar <NUM>, which is configured to connect a plurality of cylindrical battery cells <NUM> to each other in series or in parallel, is located in parallel to the cylindrical battery cells <NUM> in a state of being spaced apart therefrom by a predetermined distance.

The cover case <NUM>, which is configured to protect the upper part of the cylindrical battery cell <NUM> received in the module case <NUM>, is provided with an opening <NUM> configured to expose the upper surface of the cylindrical battery cell <NUM>. In addition, the cover case is provided with a plurality of protrusions <NUM> protruding by a predetermined height in order to protect the cylindrical battery cell <NUM> from external impact applied from above.

<FIG> is an overall perspective view of a battery module assembly apparatus having vision according to a preferred embodiment of the present invention, and <FIG> is an enlarged perspective view showing the interior of the battery module assembly apparatus having vision according to the preferred embodiment of the present invention.

Referring to <FIG> and <FIG>, the battery module assembly apparatus according to the present invention includes a transfer unit <NUM>, a vision unit <NUM>, a washing unit <NUM>, and a bonding unit <NUM>.

The transfer unit <NUM> is configured to move a battery module <NUM> in a state in which a cylindrical battery cell <NUM> to be bonded is received therein forwards and rearwards (an X-axis direction). Specifically, the transfer unit <NUM> includes a seating die <NUM> having a flat structure configured to support the battery module <NUM> in a state of being in tight contact with the bottom surface of the battery module <NUM> and a rail <NUM> configured to provide a movement path of the seating die <NUM>.

Here, it is preferable for a plurality guide portions <NUM> each having a predetermined height to be provided at corners of the seating die <NUM>, and it is more preferable for an "L"-shaped marker <NUM>' to be formed at the upper surface of each guide portion <NUM>, which will be described below.

The vision unit <NUM> is configured to scan the upper surface of the battery module <NUM> transferred in a state of being seated on the seating die <NUM> in order to determine whether the module case <NUM> is seated at a predetermined position, and is configured to scan the position of the cylindrical battery cell <NUM> received in the module case <NUM> and to transmit the result to the washing unit <NUM> and the bonding unit <NUM>.

The vision unit <NUM> configured to perform the above functions includes a first vision unit <NUM> and a second vision unit <NUM>. Specifically, the first vision unit <NUM> is located ahead of the second vision unit, i.e. a position at which the battery module <NUM> is primarily scanned after the battery module is seated on the seating die <NUM> by a worker or a separate seating means (not shown), and includes a first vision camera <NUM> and a first illumination portion <NUM>.

Here, a pair of first illumination portions <NUM> may be provided in a state of being spaced apart from each other by a predetermined distance. The first vision camera <NUM> is located above the pair of first illumination portions <NUM> to scan the upper surface of the battery module <NUM> that is moved.

That is, the first vision camera <NUM> scans the extent of twisting of the position at which the module case <NUM> is located and the position of the cylindrical battery cell <NUM> received in the module case <NUM> based on the marker <NUM>' of the guide portion <NUM>.

The second vision unit <NUM> is located behind the first vision unit <NUM>, and includes a second vision camera <NUM> and a second illumination portion <NUM>. The second vision camera <NUM> and the second illumination portion <NUM> are identical in construction and function to the first vision camera <NUM> and the first illumination portion <NUM>, respectively.

Here, the reason that the vision unit is constituted by the first vision unit <NUM> and the second vision unit <NUM>, which perform the same function while forming a pair is that it is necessary to improve accuracy in bonding and to minimize a defect rate.

That is, in the present invention, the module case <NUM> having the cylindrical battery cell <NUM> received therein is moved along the rail <NUM> in order to minimize the movement distance of the washing unit <NUM> and the bonding unit <NUM>, accurate movement of which is required, and therefore it is necessary to compare the result of the first vision unit <NUM> and the result of the second vision unit <NUM> with each other in order to determine again whether the module case is twisted during movement thereof.

<FIG> is an enlarged perspective view illustrating that the portion of the battery cell to be bonded is washed using a laser according to a preferred embodiment of the present invention.

In a process in which the cylindrical battery cell <NUM> is received in the module case <NUM> or in a process in which the cylindrical battery cell <NUM> is moved in a state of being received in the module case <NUM>, various foreign matter, such as dust or oil and fat, may be attached to the surface of the electrode, which may lead to poor welding.

In the present invention, the washing unit <NUM> is provided to minimize the number of battery modules discarded due to poor welding. Specifically, the washing unit <NUM> is provided at the lower end of a body thereof with a tip portion <NUM>, and a laser is applied through the tip portion <NUM> in order to wash the upper surface of the cylindrical battery cell <NUM>.

In particular, it is possible to wash only a region to be welded using a laser based on scanning results obtained by the first vision unit <NUM> and the second vision unit <NUM>, whereby it is possible to rapidly assemble the battery module while reducing energy consumption.

Meanwhile, the washing unit <NUM> is located in the order of the first vision unit <NUM>, the washing unit <NUM>, and the second vision unit <NUM>, or is located in the order of the first vision unit <NUM>, the second vision unit <NUM> and the washing unit <NUM>.

<FIG> is an enlarged perspective view illustrating that the battery cell and the busbar are bonded to each other via a wire according to the preferred embodiment of the present invention.

The bonding unit <NUM>, which electrically connects the positive electrode of the battery cell and the busbar to each other and electrically connects the negative electrode of the battery cell and the busbar to each other, is provided at the lower end thereof with a pointed nozzle portion <NUM>, and a molten conductive metal is discharged through the nozzle portion <NUM>.

That is, the bonding unit <NUM> is movable in an upward-downward direction, a leftward-rightward direction, and a forward-rearward direction, and performs bonding between the positive electrode of the battery cell <NUM> and the busbar and between the negative electrode of the battery cell <NUM> and the busbar in the form of a wire W while repeatedly moving based on scanning results obtained by the first vision unit <NUM> and the second vision unit <NUM>.

<FIG> is a flowchart showing a battery module assembly method according to a preferred embodiment of the present invention.

The assembly method using the battery module assembly apparatus using vision according to the present invention includes a first step of seating a battery module having a cylindrical battery cell <NUM> received therein on the transfer unit <NUM>; a second step of moving the transfer unit <NUM>; a third step of checking the position of the battery module <NUM> through the vision unit located on the movement path of the transfer unit <NUM>; and a fourth step of bonding an electrode of the cylindrical battery cell <NUM> received in the battery module <NUM> and a busbar <NUM> to each other.

Meanwhile, it is preferable to check the position of the battery module <NUM> twice in the third step, and it is more preferable to further perform a washing step before the fourth step.

That is, in the third step, the first vision unit <NUM>, the washing unit <NUM>, and the second vision unit <NUM> may be sequentially located, and therefore primary checking of the position of the battery module <NUM>, washing, and secondary checking of the position of the battery module <NUM> may be sequentially performed. In this case, the position of the battery module <NUM> can be checked before bonding even though the battery module <NUM> is somewhat misaligned during washing, whereby it is possible to accurately recognize a bonding position.

Also, in the third step, the first vision unit <NUM>, the second vision unit <NUM>, and the washing unit <NUM> may be sequentially located, and therefore primary checking of the position of the battery module <NUM>, secondary checking of the position of the battery module <NUM>, and washing may be sequentially performed. In this case, bonding may be performed immediately after washing, whereby a possibility of foreign matter attachment is reduced, and therefore it is possible to minimize bonding defects due to foreign matter.

One or more battery modules, each of which is assembled using the assembly method using vision according to the present invention, may be connected to each other in order to constitute a battery pack.

Claim 1:
A battery module assembly apparatus (<NUM>) using vision, the battery module assembly apparatus (<NUM>) comprising:
a transfer unit (<NUM>) configured to move forwards and rearwards or leftwards and rightwards when a battery module (<NUM>) having a cylindrical battery cell (<NUM>) received therein is seated on the transfer unit (<NUM>);
a vision unit (<NUM>) configured to check a position of the battery module (<NUM>);
a bonding unit (<NUM>) configured to electrically connect an electrode of the cylindrical battery cell (<NUM>) received in the battery module (<NUM>) and a busbar (<NUM>) to each other;
characterized in that the battery module assembly apparatus (<NUM>) further comprises a washing unit (<NUM>) configured to remove foreign matter from the cylindrical battery cell (<NUM>);
wherein the vision unit (<NUM>) comprises a first vision unit (<NUM>) and a second vision unit (<NUM>) and
wherein the first vision unit (<NUM>), the washing unit (<NUM>), and the second vision unit (<NUM>) are sequentially located in the named order, or wherein the first vision unit (<NUM>), the second vision unit (<NUM>), and the washing unit (<NUM>) are sequentially located in the named order.