CN112952233A

CN112952233A - Battery pack, electric tool and method for manufacturing battery pack

Info

Publication number: CN112952233A
Application number: CN201911173674.0A
Authority: CN
Inventors: 王良均
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2021-06-11
Also published as: WO2021104354A1

Abstract

The invention relates to a battery pack which comprises a shell, wherein a plurality of battery monomers are arranged in the shell, the peripheral wall of each battery monomer is respectively and independently wrapped with a cylindrical battery monomer wrapping piece, and the battery monomer wrapping pieces are detachably sleeved outside the battery monomers and are tightly attached to the battery monomers. The single battery body is separately sleeved with the single battery body wrapping piece, so that the single battery body can be combined randomly to form a battery pack with various forms, and the battery pack has better heat-conducting property. Furthermore, an electric tool with such a battery pack and a method for producing such a battery pack are proposed.

Description

Battery pack, electric tool and method for manufacturing battery pack

Technical Field

The present invention relates to the field of battery technology, and more particularly, to a battery pack, an electric tool having the battery pack, and a method of manufacturing the battery pack.

Background

In many applications, a plurality of battery cells are combined into a battery pack, and the battery pack is placed in a housing to form a battery pack. The battery package can produce the heat at the charge-discharge in-process, leads to battery temperature to rise, in order to avoid the too high battery life that influences of battery package temperature, needs in time reliably derive the heat.

In the related art, the single cell holder with heat conductivity is in interference fit with the plurality of battery cells, so that the heat conduction efficiency of the battery can be improved.

The inventor finds out in the process of implementing the technology that: the monomer retaining pieces can only accept a plurality of fixed storage battery monomers, and if the monomer retaining pieces are used on battery packs with different battery cell combinations, different monomer retaining pieces are needed, so that the universality is not strong.

Disclosure of Invention

In view of this, it is necessary to provide a battery pack in order to solve the problem of poor versatility of the cell holder.

The utility model provides a battery pack, includes the shell, the battery monomer that has a plurality of mutual electric connection in the shell, each independent parcel of every free periphery wall of battery has the battery monomer parcel piece of tube-shape, battery monomer parcel piece detachably cover is in the battery monomer external and with the battery monomer closely laminates.

Above-mentioned battery package, battery monomer cover have battery monomer parcel piece alone, therefore battery monomer can make up the group battery of formation multiple form wantonly, and this group battery has better heat conductivility.

In one embodiment, the cell wrap is made of a thermally conductive plastic or a phase change material.

In one embodiment, the inner wall of the battery cell wrapping piece is provided with a hollow part along the axial direction of the battery cell wrapping piece.

In one embodiment, the single battery is a peeled single battery with a bare conductive outer layer, and the single battery wrapping piece is in direct contact with the conductive outer layer of the single battery.

In one embodiment, the battery cells are arranged in parallel to form a stacked structure including at least one layer, the outer wall of the battery cell wrapping piece is provided with a plurality of flat portions along the axial direction of the battery cell wrapping piece, and two adjacent battery cells are attached in a manner that the flat portions are in contact with each other.

In one embodiment, the number of the flat parts is 4, and the 4 flat parts are uniformly distributed along the circumferential direction around the axis of the battery cell wrapping piece.

In one embodiment, the battery pack further comprises a first bracket and a second bracket which fix the plurality of battery cells together, and two ends of the battery cells in the axial direction are respectively fixed to the first bracket and the second bracket.

In one embodiment, two ends of the battery cell in the axial direction are exposed out of the battery cell wrapping piece, and the battery cell wrapping piece is located between the first support and the second support.

In one embodiment, the first bracket and the second bracket are respectively provided with accommodating holes, the number of the accommodating holes is consistent with the number of the single batteries, and two ends of each single battery are respectively inserted into the accommodating holes of the first bracket and the second bracket.

The electric tool comprises a shell, a motor accommodated in the shell and an actuating mechanism driven by the motor to work, wherein the shell further comprises a matching part, and the matching part can be used for removably mounting the battery pack in any one of the above modes.

Above-mentioned electric tool, detachably matched stack between the coupling portion of battery package and electric tool. The battery monomer in the battery pack is independently wrapped with a battery monomer wrapping piece for heat conduction. Therefore, the battery monomers can be combined at will to form the battery pack, and each battery monomer in the battery pack obtained by combination is externally provided with a heat conducting element, so that the heat conducting performance of the whole battery pack is ensured.

A method of manufacturing a battery pack is also provided, comprising the steps of:

providing a plurality of battery cells;

respectively wrapping cylindrical single battery wrapping pieces on each single battery;

fixing a plurality of battery monomers with the battery monomer wrapping pieces by using a bracket to form a battery pack with the battery monomers closely arranged;

the battery pack is arranged in a pack seat of a battery pack;

and covering the pack cover and the pack seat of the battery pack together to seal the battery pack in the pack seat.

In the manufacturing method, each single battery is respectively wrapped with the cylindrical single battery wrapping piece, so that the heat conduction effect of the single battery is guaranteed, the single batteries can be combined at will to form battery packs in different states and are limited by the structure of the single battery wrapping piece, and in the obtained battery pack, each single battery 20 in the battery pack is externally provided with the heat conduction element, so that the heat conduction performance of the whole battery pack is guaranteed.

In one embodiment, the battery cell wrapping member is a thermally conductive plastic, wherein the step of wrapping the cylindrical battery cell wrapping member on each battery cell includes:

heating the single battery pack to expand the inner hole of the single battery pack;

inserting the battery monomer into the inner hole of the battery monomer wrapping piece so that the battery monomer wrapping piece is tightly attached to the battery monomer

In the steps, the inner hole of the battery monomer wrapping piece is expanded in a heating mode, so that the battery monomer is easier to insert into the battery monomer wrapping piece, and the assembly efficiency is improved.

Drawings

Fig. 1 is a schematic structural diagram of a battery pack according to an embodiment of the invention;

fig. 2 is a cross-sectional view of the battery pack of fig. 1 taken along the length thereof;

fig. 3 is a cross-sectional view taken along the width direction of the battery pack in fig. 1;

fig. 4 is a schematic view of a stack of battery cells wrapped with a battery cell wrapper;

FIG. 5 is a schematic view of the stack structure shown in FIG. 4 combined with a bracket to form a battery pack;

fig. 6 is a schematic structural view of a battery cell wrapping member wrapping a battery cell;

fig. 7 is another schematic structural view of a battery cell wrapping member wrapping a battery cell;

fig. 8 is a schematic structural diagram of an electric tool according to an embodiment of the invention.

Elements in the drawings are numbered as follows:

100. battery pack

10. Outer shell 110, bag base 120 and bag cover

20. Battery monomer

30. Battery monomer wrapping 301, hollow 302 and flat part

40. Bracket 410, first bracket 420 and second bracket

200. Electric tool 210, housing 212, and attachment part

220. Electric machine

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, one embodiment of the present invention provides a battery pack 100 that may be used in a power tool. The electric tool at least comprises a battery pack, a motor powered by the battery pack and an actuating mechanism driven by the motor to work. The types of power tools include a variety of types, for example, they may be hand-held power tools, and more specifically, hand-held power tools such as electric drills, hammers, blowers, and the like.

Referring to fig. 2 and 3, fig. 2 illustrates a sectional structure along the length direction of the battery pack 100, and fig. 3 illustrates a sectional structure along the width direction of the battery pack 100. The battery pack 100 includes a housing 10 and a plurality of battery cells 20 disposed in the housing 10 and electrically connected to each other. The peripheral wall of each battery cell 20 respectively independently wraps up the battery cell parcel piece 30 of tube-shape, and battery cell parcel piece 30 detachably overlaps outside battery cell 20 and closely laminates with battery cell 20. The single battery pack 30 has a good thermal conductivity to conduct out heat released by the single battery 20 during operation, so as to improve the usage efficiency and prolong the service life. The battery cell 20 may be a rechargeable battery or a non-rechargeable battery.

In the battery pack 100, the battery cell 20 is individually wrapped with the battery cell wrapping member 30 for heat conduction. That is, each battery cell pack 30 corresponds to only one battery cell 20. Therefore, the battery monomers 20 can be combined at will to form the battery pack, and each battery monomer 20 in the battery pack obtained by combination is externally provided with a heat conducting element, so that the heat conducting performance of the whole battery pack is ensured.

The battery cells 20 may be arbitrarily combined to form a battery pack having superior heat conductive properties. For example, referring to fig. 4, a stacked structure in which 8 battery cells 20 are arranged in parallel and stacked in 2 layers is illustrated, wherein 4 battery cells 20 are arranged side by side in each layer, and a battery cell wrapping member 30 is sleeved outside each battery cell 20 in the stacked structure. Each of the battery cells 20 in the stacked structure may be formed as a battery pack in series and/or parallel. In this way, each battery cell 20 in the battery pack can be effectively thermally conducted. In other embodiments, the number of the battery cells 20 is not limited to 8, and is not limited to form a two-layer structure, and may be a stacked structure of one or more than two layers. It can be understood that, in any combination, since each battery cell 20 is independently wrapped by the heat conductive member, i.e., the battery cell wrapping member 30, the heat conductive performance of the assembled battery pack is ensured.

A plurality of battery cells 20 may be directly put into the housing 10 of the battery pack 100 one by one and formed in a stacked structure as shown in fig. 4, thereby operating in the form of a battery pack.

Referring to fig. 5, a plurality of battery cells 20 may be fixed by a bracket 40 to form an integrated battery pack, and then put into the housing 10 of the battery pack 100. In a specific embodiment, the bracket 40 includes a first bracket 410 and a second bracket 420. Both ends of the battery cell 20 in the axial direction are fixed to the first bracket 410 and the second bracket 420, respectively. The battery cell 20 is axially directed in the lengthwise direction of the battery cell, which is the case for cylindrical or strip-shaped battery cells. Specifically, the first bracket 410 fixes one ends of the plurality of battery cells 20 together, and the second bracket 420 fixes the other ends of the plurality of battery cells 20 together. By fixing the plurality of battery cells 20, into which the battery pack is to be assembled, with the bracket 40, the whole battery pack can be put together into the case 10 of the battery pack 100, enabling the manufacturing efficiency of the battery pack to be improved.

Referring to fig. 2 to 5, in some embodiments, when the plurality of battery cells 20 are fixed by the bracket 40, two ends of the battery cells 20 in the axial direction are exposed outside the battery cell wrapping member 30, and the battery cell wrapping member 30 is located between the first bracket 410 and the second bracket 420. That is, in the axial direction of the battery cell 20, the length of the battery cell wrapping 30 is smaller than that of the battery cell 20, and the battery cell wrapping 30 is fitted over the middle of the battery cell 20 and exposes both ends of the battery cell 20. Both ends of the battery cell 20 are used to be fixed to the bracket 40, so that the battery cell wrapping member 30 is only included in a portion of the battery cell 20 located between the first bracket 410 and the second bracket 420, thereby achieving the purpose of reducing the size of the battery cell wrapping member 30 and still ensuring the heat conduction effect to the battery cell 20.

As a specific solution, referring to fig. 3 and fig. 4, the first bracket 410 and the second bracket 420 are respectively provided with receiving holes (not numbered) whose number is equal to that of the battery cells 20, and two ends of the battery cells 20 are respectively inserted into the receiving holes of the first bracket 410 and the second bracket 420. Therefore, taking the first bracket 410 as an example, the first bracket 410 and each battery cell 20 are connected in a nested manner, and a simpler assembly manner is provided.

The battery cell pack 30 is provided in various ways. In one embodiment, referring to fig. 6, the cell casing 30 is made of a thermally conductive plastic, such as high density polyethylene. The thermal conductive plastic has good thermal expansion capacity, so that the inner hole of the battery monomer wrapping piece 30 can be enlarged by heating, the battery monomer 20 is conveniently loaded into the battery monomer wrapping piece 30, and the battery monomer wrapping piece 30 is matched with the battery monomer 20 more tightly.

In another embodiment, referring to fig. 7, the battery cell wrapping member 30 is made of a phase change material, so that it has a capability of performing a phase change process for changing physical properties, and the phase change material absorbs or releases a large amount of latent heat during the phase change process, thereby achieving a good heat conduction effect of the battery cell 20. When assembling the battery cell 20 to the battery cell pack 30, a proper force may be applied to insert the battery cell 20 into the inner hole of the battery cell pack 30.

In order to more conveniently insert the battery cells 20 into the inner holes of the battery cell wrapping members 30, referring to fig. 6, the inner walls of the battery cell wrapping members 30 are provided with hollows 301 along the axial direction of the battery cell wrapping members 30. The hollow 301 is a groove recessed from the inner wall surface of the battery cell wrapping member 30 by a certain depth in the radial direction, and the specific shape is not limited. The inner wall of the battery cell wrapping member 30 is hollowed out, so that the battery cell wrapping member 30 is easier to deform, and therefore the battery cell 20 is easier to insert into the battery cell wrapping member 30.

Referring to fig. 6, in a specific implementation, two hollows 301 are disposed on the inner wall of the single battery pack 30, wherein the two hollows 301 are disposed at an interval of 180 degrees, and the length of each hollow 301 is consistent with the axial length of the single battery pack 30. When the battery cell 20 is inserted into the battery cell wrapping member 30, the portions of the battery cell wrapping member 30 located at the two sides of the battery cell 20 are easy to deform, so that the battery cell 20 is easy to insert into the battery cell wrapping member 30.

In order to better dissipate heat generated during the operation of the battery cell 20, in the embodiment of the invention, the battery cell 20 is peeled in advance, so that when the battery cell wrapping member 30 is sleeved on the battery cell 20, the battery cell wrapping member 30 is in direct contact with the conductive outer layer of the battery cell. The conventional battery cell has a protective case covering a conductive outer layer of the battery cell, and exposing only the conductive outer layer covering both ends of the battery cell. In this embodiment, the single battery 20 does not have a protective casing, and the conductive outer layer of the single battery 20 is completely exposed, so that the conductive outer layer of the single battery 20 is wrapped by the single battery wrapping member 30, and the conductive outer layer and the single battery wrapping member are in direct contact, so as to conduct heat quickly.

The battery cells 20 having the battery cell pack 30 may be formed in a stacked structure including at least one layer by being arranged in parallel, thereby forming a battery pack of various forms. In order to reduce the volume of the assembled battery pack as much as possible, referring to fig. 6 and 7, the outer wall of the battery cell wrapping member 30 is provided with a plurality of flat portions 302 along the axial direction of the battery cell wrapping member 30, so that, as shown in fig. 2, two adjacent battery cells 20 in the battery pack are attached in such a manner that the flat portions 302 contact each other.

The wall thickness of the flat portion 302 is smaller than the wall thickness of other parts of the battery cell wrapping piece 30, so that the flat portions 302 of the battery cell wrapping pieces 30 on two adjacent battery cells 20 are attached to each other in a way of attaching to other parts, the size of the battery cells 20 in the arrangement direction can be reduced, the size of a battery pack formed by combination is small, and the battery pack is beneficial to being manufactured into a small-sized battery pack.

In a preferred embodiment, the number of the flat portions 302 is 4, and 4 flat portions 302 are uniformly distributed in the circumferential direction around the axis of the cell wrapping member 30. In this way, the battery cell wrapping member 30 has the flat portions 302 on the peripheral sides, so that the battery cells 20 having the battery cell wrapping member 30 have the flat portions 30 on the peripheral sides, on one hand, the battery cells 20 are more convenient to stack on other battery cells 20, and if the angle adjustment is not needed or the adjustment is performed by a very small angle; on the other hand, for a single battery cell 20, another battery cell can be stacked up, down, left and right, so that it is more convenient to combine to form battery packs in different states.

Referring to fig. 8, an embodiment of the invention further provides an electric tool 200 including the battery pack 100 of the above embodiment. Specifically, the power tool 200 includes a housing 210, a motor 220 accommodated in the housing 210, and an actuator (not shown) driven by the motor 220, wherein in fig. 8, a part of the housing 210 is removed to show the motor 220. The housing 210 has a mating portion 212, and the mating portion 212 can removably mount the aforementioned battery pack 100. I.e., the battery pack 100 and the coupling part 212.

The power tool, the battery pack 100 and the mating part 212 of the power tool 200 are detachably assembled. The battery cells 20 in the battery pack 100 are individually wrapped with the battery cell wrapping members 30 for heat conduction. Therefore, the battery monomers 20 can be combined at will to form the battery pack, and each battery monomer 20 in the battery pack obtained by combination is externally provided with a heat conducting element, so that the heat conducting performance of the whole battery pack is ensured.

An embodiment of the present invention also provides a method of manufacturing the battery pack 100, including the following steps.

And S100, providing a plurality of battery cells 20. The battery cell may specifically be the battery cell 20 subjected to the peeling process described above.

And S200, respectively wrapping the cylindrical single battery pack 30 on each single battery 20. Specifically, each battery cell 20 is inserted into one battery cell wrapping member 30, and both ends of the battery cell wrapping member 30 are exposed outside. The cell wrap 30 makes contact with the conductive housing of the peeled cell 20.

And S300, fixing the plurality of battery cells 20 with the battery cell wrapping pieces 30 by using a bracket 40 to form a battery pack with the battery cells 20 tightly arranged.

And S400, assembling the battery pack into the pack seat 110 of the battery pack 100.

Referring to fig. 2, the housing 10 of the battery pack 100 includes a pack holder 110 and a pack cover 120 coupled to the pack holder 110. Before the battery pack is put in, the pack cover 120 and the pack holder 110 are in an open state. The connection between the cover 120 and the seat 110 is flexible, for example, one end of the cover 120 is rotatably connected to the seat 110 to close or open the seat 110; or the bag cover 120 is detachably coupled to the bag base 110, when the bag cover 120 is separated from the bag base 110, the battery pack can be placed into the bag base, and when the bag cover 120 is closed to the bag base 110, the bag base 110 is closed.

And S500, covering the pack cover 120 and the pack seat 110 of the battery pack 100 together to seal the battery pack in the pack seat 110.

In the above manufacturing method, each single battery 20 is wrapped with the cylindrical single battery wrapping member 30, so as to ensure the heat conduction effect on the single battery 20, and the single batteries 20 can be combined to form battery packs in different states at will and are limited by the structure of the single battery wrapping member 30, so that in the obtained battery pack 100, each single battery 20 in the battery pack is provided with a heat conduction element, so as to ensure the heat conduction performance of the whole battery pack.

In a specific embodiment, the battery cell wrapping member 30 is a thermal conductive plastic, wherein the step of wrapping the cylindrical battery cell wrapping member on each battery cell, that is, the step S200, includes: heating the single battery pack 30 to expand the inner hole of the single battery pack 30; inserting the battery cell 20 into the inner hole of the battery cell wrapping piece so that the battery cell wrapping piece is tightly attached to the battery cell.

In the above steps, the inner hole of the cell wrapping member 30 is enlarged by heating, so that the battery cell 20 is more easily inserted into the cell wrapping member, and the assembly efficiency is improved.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a battery pack, its characterized in that, which comprises an outer shell, the battery monomer that has a plurality of mutual electric connection in the shell, each independent parcel of every free periphery wall of battery has the battery monomer parcel piece of tube-shape, battery monomer parcel piece detachably cover be in the battery monomer external and with the battery monomer closely laminates.

2. The battery pack of claim 1, wherein the battery cell pack is made of thermally conductive plastic or phase change material.

3. The battery pack according to claim 1, wherein the inner wall of the cell wrapping member is provided with a hollow along the axial direction of the cell wrapping member.

4. The battery pack of claim 1, wherein the battery cells are peeled and exposed with an outer conductive layer, and the battery cell wrapping member is in direct contact with the outer conductive layer of the battery cells.

5. The battery pack according to claim 1, wherein the plurality of battery cells are arranged in parallel to form a stacked structure including at least one layer, the outer wall of the battery cell wrapping member is provided with a plurality of flat portions along the axial direction of the battery cell wrapping member, and two adjacent battery cells are attached to each other such that the flat portions contact each other.

6. The battery pack according to claim 5, wherein the number of the flat portions is 4, and the 4 flat portions are uniformly distributed in the circumferential direction around the axis of the battery cell wrapping member.

7. The battery pack according to claim 1, further comprising a first bracket and a second bracket that fix the plurality of battery cells together, wherein both ends of the battery cells in the axial direction are fixed to the first bracket and the second bracket, respectively.

8. The battery pack according to claim 7, wherein the battery cells are exposed at both ends in the axial direction thereof outside the battery cell wrapping member, and the battery cell wrapping member is located between the first bracket and the second bracket.

9. The battery pack according to claim 8, wherein the first bracket and the second bracket are respectively provided with accommodating holes, the number of the accommodating holes is equal to that of the single batteries, and two ends of each single battery are respectively inserted into the accommodating holes of the first bracket and the second bracket.

10. An electric power tool comprising a housing, a motor housed in the housing, and an actuator driven by the motor, wherein the housing further comprises a mating portion to which the battery pack according to any one of claims 1 to 9 is removably mountable.

11. A method of manufacturing a battery pack, comprising the steps of:

providing a plurality of battery cells;

the battery pack is arranged in a pack seat of a battery pack;

12. The method of claim 11, wherein the cell wrapping is a thermally conductive plastic, and wherein the step of wrapping the cylindrical cell wrapping on each cell comprises:

and inserting the battery monomer into an inner hole of the battery monomer wrapping piece so that the battery monomer wrapping piece is tightly attached to the battery monomer.