Patent Description:
A secondary battery is widely used as a power source not only for small electronic devices such as mobile devices, laptops and cameras, but also recently for electric scooters (E-scooters), electric vehicles (EV), hybrid electric vehicles (HEV), and the like, which are attracting attention as alternatives to scooters or vehicles using fossil fuels.

A small electronic device is equipped with one secondary battery cell or two to four secondary battery cells, but a medium or large device such as an electric scooter or an electric vehicle is equipped with a secondary battery pack. The secondary battery pack includes at least one secondary battery module, and the secondary battery module includes a plurality of secondary battery cells.

In addition, the secondary battery pack may be configured to further include various devices (for example, a BMS, a current sensor, a fuse, etc.) for controlling the charging and discharging of the secondary battery module and a pack case for safely accommodating the various devices.

Meanwhile, a handle is sometimes attached to a pack case so that the battery pack may be easily transported and installed. In particular, since a battery pack mounted to an electric scooter is relatively small compared to a battery pack mounted to an electric vehicle, a handle is often attached to the pack case for the convenience of a user who carries the battery pack.

In most cases, the handle is attached in a hook-type method or a bolt-type method. Among them, the bolt-type method is more preferred because the hook-type method has weaker impact resistance than the bolt-type method. Patent Document <NUM> (<CIT>) and Patent Document <NUM> (<CIT>) disclose an example in which a handle is attached to a case in a bolt type, respectively.

However, in the handle fixing structure of a bolt type according to the prior art, a gap may be generated between the handle and the case due to the phenomenon that the screw is loosened due to the torque applied by vibration. Since the small battery pack for an electric scooter is used in an environment that is continuously subjected to vibration, a vibration test is performed after the product is completed. At this time, the product defect rate caused by the gap of the handle is not small.

Further prior art is described in <CIT>, <CIT>, <CIT> and <CIT>.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery pack, which may prevent a gap from being generated at a handle by blocking loosening of a screw even in a continuous vibration environment.

In one aspect of the present disclosure, there is provided a battery pack, comprising: a case configured to accommodate battery cells; and a handle attached to an outer side of the case, wherein the handle includes: a handle bottom cover fixedly coupled to the case by a screw member; a handle plate disposed to be layered on the handle bottom cover and having a perforated hole through which the screw member passes; and a handle top cover configured to cover the handle plate and coupled to the handle bottom cover, wherein the handle plate has a thread formed in the perforated hole, and wherein the handle top cover includes a screw loosening prevention member formed to protrude on an inner surface thereof and configured to press a top end of the screw member located at an upper surface of the handle plate.

The screw member may be configured to be screwed to the perforated hole and a fastening groove formed at the case, respectively.

The screw member may include a head portion configured to form the top end of the screw member; and a shaft portion configured to extend from the head portion to pass through the handle plate and the handle bottom cover so that a distal end thereof is interposed in the fastening groove.

The head portion may have a screwdriver groove configured to rotate by a screwdriver and an expansion plate formed to radially extend from the screwdriver groove.

The screw loosening prevention member may be configured to be in perpendicular contact with the expansion plate.

The screw loosening prevention member may be configured in a pipe shape that has an inner diameter greater than the screwdriver groove without exceeding the expansion plate and is in perpendicular contact with the expansion plate.

The expansion plate may have a pin hole formed therethrough in a thickness direction, and the screw loosening prevention member may include an anti-rotation pin configured to be inserted into the pin hole.

The screw loosening prevention member may be configured in a pipe shape that has an inner diameter greater than the screwdriver groove without exceeding the expansion plate and is in perpendicular contact with the expansion plate, and the anti-rotation pin may be formed to protrude from a bottom end of the pipe shape.

A hooking hole may be formed in any one of the handle bottom cover and the handle top cover, and a hook configured to be hooked in the hooking hole may be provided to the other of the handle bottom cover and the handle top cover.

The case may include a case housing; and a case cover coupled to the case housing, wherein the case cover may be formed to be concave between a left side portion and a right side portion thereof, and the handle may be configured such that both ends thereof are fixedly coupled to the left side portion and the right side portion.

The screw member may have a distal end fixed to a fastening groove formed at the case, and the fastening groove may include an insert nut, and the insert nut has a sawtooth pattern formed at an outer side thereof along a circumferential direction.

In another aspect of the present disclosure, there is also provided an electric scooter, comprising the battery pack described above.

According to an embodiment of the present disclosure, it is possible to provide a battery pack, which may prevent a gap from being generated at a handle by blocking loosening of a screw even in a continuous vibration environment.

The effect of the present disclosure is not limited to the above, and effects not mentioned herein will be clearly understood by those skilled in the art from this specification and the accompanying drawings.

<FIG> is an exploded perspective view showing a case and a handle, employed at a battery pack according to an embodiment of the present disclosure, and <FIG> is an assembled perspective view showing the battery pack of <FIG>.

Referring to these drawings, a battery pack <NUM> according to an embodiment of the present disclosure includes battery cells (not shown), a case <NUM> for accommodating the battery cells, and a handle <NUM> attached to an outer side of the case <NUM>.

The battery cells may be lithium secondary batteries having a high energy density per unit weight. The lithium secondary battery may be classified depending on the shape of an exterior material into a can-type secondary battery in which an electrode assembly is accommodated into a metal can and a pouch-type secondary battery in which the electrode assembly is accommodated in a laminate sheet-type pouch.

The pouch-type secondary battery has advantages of easy stacking and high energy density, but has a disadvantage since it is weak against external impact due to low mechanical rigidity. Meanwhile, the can-type secondary battery has superior mechanical rigidity, so its durability against external impact is superior to that of the pouch-type secondary battery. In this regard, in the battery pack <NUM> of this embodiment, the can-type secondary battery may be employed as a battery cell. Of course, the scope of the present disclosure is not limited to the can-type lithium secondary battery. The can-type lithium secondary battery may be replaced with the pouch-type lithium secondary battery, or a secondary battery other than a lithium secondary battery such as a nickel-cadmium battery or a nickel-hydrogen battery.

The case <NUM> may include a case housing <NUM> and a case cover <NUM> coupled to the case housing <NUM>.

The case housing <NUM> may be provided in a box shape with one side open.

Although not shown in order not to obscure the the present disclosure, a cell module assembly including battery cells, a frame capable of holding the battery cells, a metal plate for electrically connecting the battery cells, a harness wire for voltage sensing, and a BMS for controlling the charging and discharging of the battery cells and a current sensor may be accommodated in the case housing <NUM>.

The case cover <NUM> is configured to cover the opening of the case housing <NUM>, and may be coupled to the case housing <NUM> by bolting and hooking the case housing <NUM>.

In addition, as shown in <FIG> and <FIG>, the case cover <NUM> may include a left side portion <NUM> and a right side portion <NUM> protruding in a substantially "U" shape, and a concave form may be formed between them. The configuration of the case cover <NUM> has an advantage that when both ends of the handle <NUM> are fixedly coupled to the left side portion <NUM> and the right side portion <NUM>, a space for a user to hold the handle <NUM> may be easily secured. In particular, even if the external shape of the handle <NUM> is made in a very simple shape as in this embodiment, the user may easily hold the handle <NUM>.

Seeing the configuration of the case cover <NUM> according to this embodiment in more detail, the case cover <NUM> further includes a handle installation groove <NUM> that is shaped such that a left end and a right end of the handle <NUM> are respectively fit into the left side portion <NUM> and the right side portion <NUM>. The handle installation groove <NUM> may act to accurately guide an assembly position of the handle <NUM> and hold the handle <NUM> not to be twisted in case of shock or vibration.

In addition, as shown in <FIG>, a fastening groove <NUM> may be provided at a bottom surface of the handle installation groove <NUM>. The fastening groove <NUM> may be provided to be recessed to a predetermined depth from the surface of the bottom surface, and an insert nut <NUM> may be provided in the fastening groove <NUM>. For reference, the insert nut <NUM> may be interposed in the fastening groove <NUM> of the case cover <NUM> by insert molding. The insert nut <NUM> has a sawtooth pattern on its outer surface along a circumferential direction and thus may sufficiently withstand the torque of a screw member <NUM>.

Meanwhile, the handle <NUM> according to the present disclosure has a handle loosening prevention structure that prevents the screw from loosening in an environment where continuous vibration is applied to the battery pack <NUM>.

Seeing main components of the handle <NUM> according to the present disclosure, the handle <NUM> includes a screw member <NUM>, a handle bottom cover <NUM>, a handle plate <NUM>, and a handle top cover <NUM>.

The screw member <NUM> is a means for fixing the handle bottom cover <NUM> to the case cover <NUM>, and may be screwed to the fastening groove <NUM> of the case cover <NUM>. Any type of screw member <NUM> may be used as long as a screw capable of being screwed into the fastening groove <NUM> is formed.

Specifically, referring to <FIG> and <FIG>, the screw member <NUM> according to this embodiment may include a head portion <NUM> having a larger diameter and a shaft portion <NUM> having a smaller diameter than the head portion <NUM> and having a screw formed on an outer circumferential surface thereof.

The head portion <NUM> may include a screwdriver groove 211a provided to be rotated by a screwdriver and an expansion plate 211b extending radially from the screwdriver groove 211a. In this embodiment, the screwdriver groove 211a has a cross shape, but the screwdriver groove 211a may be replaced with a straight or hexagon wrench groove shape as desired. The expansion plate 211b may be provided in a disk shape around the screwdriver groove 211a. However, the expansion plate 211b does not have to be in a disk shape, and may be provided in a triangular plate shape or a square plate shape.

The shaft portion <NUM> may be provided to extend from the head portion <NUM> and pass through the handle plate <NUM> and the handle bottom cover <NUM> so that a distal end thereof may be fixed in a state of being screwed into the fastening groove <NUM> of the case cover <NUM>. For reference, the specifications such as thickness or length of the shaft portion <NUM> may be variously determined according to the specifications of the handle plate <NUM>, the handle bottom cover <NUM> and the fastening groove <NUM>.

The handle bottom cover <NUM> is a part that is fixedly coupled to the case cover <NUM> by the screw member <NUM>, and may be injection-molded with a plastic material.

The handle bottom cover <NUM> may be provided to accommodate the handle plate <NUM> and to be coupled to and released from the handle top cover <NUM>. At this time, a hook fastening method may be applied to facilitate coupling and releasing. To this end, in this embodiment, a hooking hole <NUM> is formed in the handle bottom cover <NUM>, and a hook <NUM> capable of being hooked into the hooking hole <NUM> is provided at the handle top cover <NUM>. Of course, contrary to this embodiment, it is also possible that the hook <NUM> is provided at the handle bottom cover <NUM> and the hooking hole <NUM> is provided in the handle top cover <NUM>.

The handle bottom cover <NUM> may have a length corresponding to a linear distance between the left side portion <NUM> and the right side portion <NUM> of the case cover <NUM>, and may be configured to have bottom grooves <NUM> formed at both ends thereof such that the screw member <NUM> is inserted therein. If both ends of the handle bottom cover <NUM> are aligned with the handle installation groove <NUM> of the left side portion <NUM> of the case cover <NUM> and the handle installation groove <NUM> of the right side portion <NUM> of the case cover <NUM>, the bottom groove <NUM> and the fastening groove <NUM> may be naturally matched up and down.

The handle plate <NUM> is a part arranged in a layer form on the handle bottom cover <NUM> and fixedly coupled to the case cover <NUM> together with the handle bottom cover <NUM> by the screw member <NUM>. Both ends of the handle plate <NUM> are provided with perforated holes <NUM> through which the screw member <NUM> may pass, and the handle plate <NUM> may be arranged in a layer form on the handle bottom cover <NUM> so that the perforated hole <NUM> is matched with the bottom groove <NUM>.

The handle plate <NUM> may be made of a metal material such as stainless steel. By adding the handle plate <NUM> with high strength on the handle bottom cover <NUM> made of plastic, it is possible to prevent the handle bottom cover <NUM> from being damaged when the screw member <NUM> is fastened thereto, and it is possible to strengthen the mechanical strength of the handle <NUM>.

In particular, as shown in <FIG>, the handle plate <NUM> of the present disclosure further includes a thread 231a formed in the perforated hole <NUM> so as to be screwed with the screw member <NUM>. The thread 231a is formed in the perforated hole <NUM> as above in order to provide a structure for forcing the screw member <NUM> to rise above the handle plate <NUM> when the screw member <NUM> is loosened. This will be described later in more detail.

The handle top cover <NUM> is a part that covers the handle plate <NUM> and is coupled with the handle bottom cover <NUM>, and may be injection-molded with the same plastic material as the handle bottom cover <NUM>. As described above, the handle top cover <NUM> may be fixedly coupled to the handle bottom cover <NUM> by hooking the hook <NUM> into the hooking hole <NUM> of the handle bottom cover <NUM>. Additionally, an adhesion sheet <NUM> may be added between the handle plate <NUM> and the handle top cover <NUM> to further strengthen the fixability of the handle top cover <NUM>.

In particular, as shown in <FIG>, the handle plate <NUM> according to the present disclosure includes a screw loosening prevention member <NUM>.

The screw loosening prevention member <NUM> may be configured to protrude from an inner surface (a lower surface) of the handle top cover <NUM> and to press a top end of the screw member <NUM>, namely the head portion <NUM>, located on the upper surface of the handle plate <NUM>.

The screw loosening prevention member <NUM> according to this embodiment is positioned at both ends of the handle top cover <NUM>, and may be provided to perpendicularly contact the expansion plate 211b of the head portion <NUM> of the screw member <NUM>. More specifically, as shown in <FIG>, the screw loosening prevention member <NUM> may be implemented in a pipe shape having an inner diameter that is greater than the screwdriver groove 211a of the head portion <NUM> of the screw member <NUM> and does not exceed the expansion plate 211b.

For example, when the handle plate <NUM> and the handle bottom cover <NUM> are integrally fixed to the case cover <NUM> by the screw member <NUM> and the handle top cover <NUM> is coupled to the handle bottom cover <NUM>, the screwdriver groove 211a is placed in the inner space of the pipe shape, and the expansion plate 211b comes into perpendicular contact with the bottom end of the pipe shape.

Hereinafter, the structure for preventing loosening of the handle <NUM> as above will be described in detail.

After the handle bottom cover <NUM> and the handle plate <NUM> are disposed on the case cover <NUM> in order, the shaft portion <NUM> of the screw member <NUM> is interposed into the perforated hole <NUM>, and the screw member <NUM> is rotated in a clockwise direction by using a screwdriver until the expansion plate 211b of the screw member <NUM> comes into contact with the upper surface of the handle plate <NUM>, thereby being fastened to the case cover <NUM>. In this case, the shaft portion <NUM> of the screw member <NUM> may be screwed into the perforated hole <NUM> of the handle plate <NUM> and the fastening groove <NUM> of the case cover <NUM>, respectively.

After that, the hook <NUM> of the handle top cover <NUM> is hooked into the hooking hole <NUM> of the handle bottom cover <NUM> so that the handle top cover <NUM> is coupled with the handle bottom cover <NUM>. At this time, the screw loosening prevention member <NUM> is in perpendicular contact with the upper surface of the expansion plate 211b.

If the structure for preventing loosening of the handle <NUM> according to the present disclosure is used, even if a torque is applied to the screw member <NUM> in a counterclockwise direction due to vibration continuously applied to the battery pack <NUM>, since the screw loosening prevention member <NUM> presses the expansion plate 211b of the screw member <NUM> from above, the screw coupling is not loosened.

In other words, the screw loosening prevention member <NUM> is a means to prevent the screw member <NUM> from rising upward, and in order to utilize this screw loosening prevention member <NUM>, the thread 231a is further added to the perforated hole <NUM> of the handle plate <NUM>.

For example, assuming that torque is applied to the screw member <NUM> in a counterclockwise direction in a state where the thread 231a is not provided to the perforated hole <NUM> of the handle plate <NUM>, as the screw member <NUM> is loosened in the counterclockwise direction inside the fastening groove <NUM>, the entire handle <NUM> rises upward. That is, in this case, even if the screw loosening prevention member <NUM> is in contact with the expansion plate 211b, since the entire handle <NUM> rises in that state, the screw loosening prevention member <NUM> cannot function properly.

Meanwhile, in the same situation as above, if the thread 231a is provided to the perforated hole <NUM> of the handle plate <NUM> and the screw member <NUM> is doubly screwed into the fastening groove <NUM> and the perforated hole <NUM>, the screw member <NUM> is able to rise upward only when its screw coupling is loosened from both the fastening groove <NUM> and the perforated hole <NUM>. However, since the screw loosening prevention member <NUM> presses the screw member <NUM> perpendicularly not to rise above the handle plate <NUM>, the screw member <NUM> is not loosened from both the perforated hole <NUM> and the fastening groove <NUM>.

Therefore, in the battery pack <NUM> according to the present disclosure, since the handle <NUM> is fixed to the case cover <NUM> as described above, the handle <NUM> may not be separated even in a continuous vibration environment.

<FIG> is a diagram showing a screw member according to another embodiment of the present disclosure, <FIG> is a diagram showing a screw loosening prevention member <NUM> according to another embodiment of the present disclosure, and <FIG> is a sectional view showing a screwing structure of the case cover <NUM> and the handle <NUM> according to another embodiment of the present disclosure.

Next, another embodiment of the present disclosure will be described with reference to <FIG>. The same reference numerals denote the same members, and the same members will not be described again, and features different from the former embodiment will be mainly described.

Another embodiment of the present disclosure is substantially identical to the former embodiment, except for the screw member <NUM> and the screw loosening prevention member <NUM>.

As shown in <FIG>, the screw member <NUM> according to this embodiment may further include a pin hole 211c formed through the expansion plate 211b in a thickness direction. At least one pin hole 211c may be provided along a circumferential direction of the expansion plate 211b.

In addition, as shown in <FIG>, the screw loosening prevention member <NUM> according to this embodiment may further include an anti-rotation pin 243a provided to be inserted into the pin hole 211c.

The anti-rotation pin 243a is formed to protrude further downward from the bottom end of the pipe shape and may be provided in a one-to-one relationship with the pin hole 211c.

After the handle plate <NUM> and the handle bottom cover <NUM> are fixed to the case cover <NUM> by the screw member <NUM>, while the handle top cover <NUM> is being coupled to the handle bottom cover <NUM>, the anti-rotation pin 243a may be interposed into the pin hole 211c of the screw member <NUM> as shown in <FIG>.

According to the configuration of this embodiment as above, since the anti-rotation pin 243a is interposed into the pin hole 211c of the screw member <NUM>, the rotation of the screw member <NUM> may be blocked during vibration. In this case, even if the thread 231a is not provided to the perforated hole <NUM>, the screw member <NUM> itself cannot rotate, so the screw coupling may not be loosened in the fastening groove <NUM>.

In addition, in the former embodiment, the screw loosening prevention member <NUM> having a pipe shape is able to press the screw member <NUM> perpendicularly because the handle top cover <NUM> is hooked to the handle bottom cover <NUM>. However, if a very large torque is applied due to vibration, the hook <NUM> may be damaged as an external force is concentrated on the hook <NUM>.

However, in this embodiment, the force applied to the hook <NUM> may be distributed since the screw loosening prevention member <NUM> acts to press the screw member <NUM> perpendicularly and simultaneously hold the screw member <NUM> not to rotate. Therefore, according to this embodiment, even if vibration is continuously applied to the battery pack <NUM>, it is possible to prevent the screw member <NUM> from being loosened, in a more stable way.

Meanwhile, the battery pack <NUM> according to the present disclosure described above may be applied to an electric scooter. That is, the electric scooter according to the present disclosure may include the battery pack <NUM> as a power source. The use of the battery pack <NUM> is not necessarily limited to an electric scooter, and the battery pack <NUM> may also be applied to, for example, an electric quick board, an electric vehicle, an energy storage device, and the like.

Claim 1:
A battery pack (<NUM>), comprising:
a case (<NUM>) configured to accommodate battery cells; and
a handle (<NUM>) attached to an outer side of the case (<NUM>),
wherein the handle (<NUM>) includes:
a handle bottom cover (<NUM>) fixedly coupled to the case (<NUM>) by a screw member (<NUM>);
a handle plate (<NUM>) disposed to be layered on the handle bottom cover (<NUM>) and having a perforated hole (<NUM>) through which the screw member (<NUM>) passes; and
a handle top cover (<NUM>) configured to cover the handle plate (<NUM>) and coupled to the handle bottom cover (<NUM>),
wherein the handle plate (<NUM>) has a thread (231a) formed in the perforated hole (<NUM>), and
wherein the handle top cover (<NUM>) includes a screw loosening prevention member (<NUM>) formed to protrude on an inner surface thereof and configured to press a top end of the screw member (<NUM>) located at an upper surface of the handle plate (<NUM>).