A battery pack for electric tools

Abstract

The utility model belongs to the field of lithium battery electrical components and relates to a battery pack for electric tools, comprising a battery shell, wherein a plurality of groups of battery cells are arranged in the battery shell, each group of battery cells are connected in series to form a connection circuit, and the connection circuits are connected in series or in parallel to form a discharge circuit of the battery pack, a partition part is provided on the connection circuit of each group of battery cells, and a trigger mechanism for connecting the partition part is also provided, and the trigger mechanism is maintained in the battery shell, which effectively reduces the risk of short circuit and improves the safety of the battery pack.

Description

Technical Field

[0001] The utility model belongs to the field of lithium battery electrical components and relates to a battery pack which is detachably mounted on electric equipment, in particular to a battery pack for electric tools. Background Art

[0002] As people increase the usage time and power of electric tools, the capacity and power of lithium-ion battery packs are getting larger and larger. Large-capacity, high-power battery packs also lead to an increase in current or voltage. When the positive and negative terminals of the battery pack are short-circuited externally, hundreds or even thousands of amperes of short-circuit current will be generated. Such a large short-circuit current can cause damage to the circuit board and the electronic components on it, or even the battery cell itself, or even cause a fire and cause irreparable losses.

[0003] At present, the common way to deal with battery pack short circuit is to use battery short circuit protection circuit. The function of short circuit protection circuit is to shut down the discharge and cut off the short circuit current when the current exceeds the set threshold and lasts for more than the set delay time. However, short circuit protection circuit is not only expensive, but also has different quality from different manufacturers. There is an urgent need to provide a stable and reliable battery pack. Utility Model Content

[0004] The purpose of the utility model is to provide a battery pack for an electric tool. By designing the circuit inside the battery pack and the battery pack structure and setting a trigger mechanism, the risk of short circuit is reduced, so that the safety of the entire battery pack is greatly improved, and at the same time, the short-circuit protection circuit is omitted, thereby reducing the manufacturing cost.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model relates to a battery pack for an electric tool, comprising a battery shell, wherein a plurality of groups of battery cells are arranged in the battery shell, wherein each group of battery cells are connected in series to form a connection circuit, wherein the connection circuits are connected in series or in parallel to form a discharge circuit of the battery pack, and a partition is provided on the connection circuit of each group of battery cells, and a positive terminal and a negative terminal are provided at the mounting end of the battery shell, which are respectively connected to the positive electrode and the negative electrode of the discharge circuit of the battery pack connected in series or in parallel, and are used to be connected to the positive and negative ends of the electric tool; a trigger mechanism for connecting the partition is also provided on the battery shell, and before the battery pack is installed on the electric tool, the trigger mechanism is not in contact with the partition, and the discharge circuit is in a disconnected state, and after the battery pack is installed on the electric tool, the trigger mechanism is in contact with the partition, and the discharge circuit is in a connected state.

[0007] In the utility model, each group of battery cells are connected in series to form a connection circuit, and the connection circuits are connected in series or in parallel to form a discharge circuit of the battery pack. A partition is provided on the connection circuit of each group of battery cells. By disconnecting the battery cells inside the battery pack, even if the positive and negative electrodes are short-circuited for some reason, no current will be generated in the entire discharge circuit, thereby improving the safety of the battery. A trigger mechanism is provided on the battery housing, and the entire circuit can be conveniently connected by operating the trigger mechanism, thereby facilitating the use of the battery pack.

[0008] Furthermore, the trigger mechanism has an I-shaped cross section and includes a clamping portion, a contact portion and a connecting portion. Two ends of the connecting portion are each provided with a clamping portion and a contact portion, and the two contact portions are electrically connected.

[0009] The trigger mechanism of the utility model is configured as an I-shape including a snap-fit ​​portion, a contact portion and a connecting portion, so that the trigger mechanism can be retained in the battery pack and easily moved by external actuation to achieve a transition from an off state to an on state, while also facilitating the charging of the battery pack for reuse.

[0010] Furthermore, an operating hole is provided at the mounting end of the battery housing, and thickened portions are provided on the housing on both sides of the operating hole. A retaining groove is provided on the inner side of the thickened portion. Before the battery pack is installed on the power tool, the engaging portion of the trigger mechanism is located in the retaining groove, so that the trigger mechanism remains inside the battery housing.

[0011] The trigger mechanism is retained inside the battery housing and is connected to the outside through an operating hole to avoid being exposed and affecting the installation of the battery pack and is not easily damaged. A thickened portion is provided on the housing, and a stopping groove is provided on the inner side of the thickened portion. Before the battery pack is installed on the power tool, the engaging portion of the trigger mechanism is located in the stopping groove. The thickened portion has a certain strength and is installed in cooperation with the engaging portion, so as to firmly hold the trigger mechanism and prevent it from falling off during transportation or storage.

[0012] Furthermore, the electric tool is provided with an actuator that cooperates with the trigger mechanism. After the battery pack is installed on the electric tool, the actuator actuates the trigger mechanism, so that the trigger mechanism contacts the partition part and the discharge circuit is in a connected state.

[0013] The utility model provides an actuating member on the electric tool. After the battery pack is installed on the electric tool, the actuating member actuates the trigger mechanism to put the discharge circuit in a connected state, which is convenient for operating the trigger mechanism. The circuit is connected only after installation, thereby effectively improving the safety of the battery pack.

[0014] Furthermore, the actuating member is a rod-shaped member or a protrusion provided on the electric tool.

[0015] The rod-shaped member or the protrusion makes it easy to extend into the operating hole, which is convenient for actuation. At the same time, the cooperation between the rod or the protrusion and the slot hole can also play a guiding role, which is convenient for the installation of the battery pack.

[0016] Furthermore, the battery cell is a lithium-ion battery cell.

[0017] Lithium-ion cells make the battery pack reusable.

[0018] Furthermore, the engaging portion is in the shape of a convex sphere, and the retaining groove is in the shape of a concave sphere matching therewith.

[0019] The spherical fit between the snap-fit ​​portion and the stop groove can not only reliably retain the trigger mechanism inside the battery housing when not installed, but also can be easily disengaged during installation and easily re-engaged.

[0020] Furthermore, the trigger mechanism is located between the positive terminal and the negative terminal, and the operating hole is opposite to the trigger mechanism.

[0021] The positive terminal and the negative terminal are located at the installation end of the battery pack, and the trigger mechanism is arranged between the positive terminal and the negative terminal, so that the trigger mechanism is closer to the power tool and is easy to be actuated.

[0022] Furthermore, a protective device is provided on the outer side of the operating hole.

[0023] The protective device is arranged outside the operation hole to prevent dust or liquid from entering the battery pack, thereby improving the safety of the battery pack.

[0024] Compared with the prior art, the utility model provides a battery pack for an electric tool, which has the following beneficial effects:

[0025] 1. In the utility model, each group of battery cells is internally connected in series to form a connection circuit, and the connection circuits are connected in series or in parallel to form a discharge circuit of the battery pack. A partition is provided on the connection circuit of each group of battery cells. This arrangement disconnects the battery cells inside the battery pack. Even if the positive and negative poles are short-circuited for some reason, no current will be generated in the entire discharge circuit. An actuator is provided on the power tool, and the battery pack is connected only after it is installed on the power tool, which effectively improves the safety of the battery pack.

[0026] 2. A trigger mechanism is provided on the battery housing. The trigger mechanism is provided in an I-shape including a snap-fit ​​portion, a contact portion and a connecting portion. The trigger mechanism can be retained in the battery pack and easily moved by external actuation to achieve a transition from an off state to an on state. It is also convenient for charging the battery pack for reuse.

[0027] 3. An operating hole is provided to connect the trigger mechanism to the outside, so as to avoid exposure that affects the installation of the battery pack and is not easily damaged. Through the shape matching of the snap-fit ​​portion and the retaining groove, the trigger mechanism is reliably retained inside the battery housing and can be easily disengaged, which is convenient for transportation, storage and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The utility model is a schematic diagram of the overall structure of a battery pack for an electric tool.

[0029] Figure 2 The utility model is a schematic diagram of a series circuit of a battery pack for an electric tool.

[0030] Figure 3 The utility model is a schematic diagram of a parallel circuit of a battery pack for an electric tool.

[0031] Figure 4 This is a schematic diagram of a trigger mechanism of a battery pack for an electric tool before being actuated.

[0032] Figure 5 This is a schematic diagram of a trigger mechanism of a battery pack for an electric tool after being activated according to the utility model.

[0033] Figure 6 It is a schematic diagram of a battery short circuit protection circuit in the prior art.

[0034] Among them, in the figure: 1, battery case; 2, positive terminal; 3, negative terminal; 4, trigger mechanism; 4-1, snap-fitting part; 4-2, contact part; 4-3, connecting part; 5, battery cell; 6, negative electrode; 7, positive electrode; 8, partition part; 9, stop groove; 10, actuator; 11, thickened part; 12, operating hole. DETAILED DESCRIPTION

[0035] The following is a clear and explicit description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. The descriptions herein are merely exemplary embodiments, which are only for the purpose of illustration and are not intended to limit the scope of the present invention. Therefore, it should be understood that various modifications and variations may be made thereto without departing from the scope of the present invention.

[0036] like Figure 1-3As shown, the embodiment of the utility model provides a battery pack for electric tools, which can be electric screwdrivers, electric drills, electric labeling machines, electric medical devices, etc., including a battery housing 1, in which multiple groups of battery cells 5 are installed. The number and voltage of the battery cells are selected according to needs. Each group of battery cells are connected in series to form a connection circuit. The connection circuits are finally connected to form a discharge circuit of the battery pack. The connection mode can be selected in series or in parallel, depending on the requirements for the output voltage. A partition part 8 is provided on the connection circuit of each group of battery cells. The mounting end of the battery housing 1 is provided with a positive terminal 2 and a negative terminal 3, which are respectively connected to the positive electrode 7 and the negative electrode 6 of the battery pack discharge circuit connected in series or in parallel, and are used to connect to the positive and negative ends of the electric tool. Through the connection of the positive and negative terminals with the positive and negative electrodes, the battery pack supplies power to the electric tool.

[0037] like Figure 1 , 4 -5, the battery housing 1 is also provided with a trigger mechanism 4 for connecting the partition 8. Before the battery pack is installed in the power tool, the trigger mechanism 4 does not contact the partition 8, and the discharge circuit is in a disconnected state. After the battery pack is installed in the power tool, the trigger mechanism 4 contacts the partition 8, and the discharge circuit is in a connected state. It should be noted that the partition 8 can be provided with one or more. Figure 2 and Figure 3 A plurality of partition parts 8 are shown. In this embodiment, a plurality of trigger mechanisms 4 may be provided accordingly, or the trigger mechanism may remain as one and the number of corresponding contact parts may be increased, and both may be provided as required.

[0038] The trigger mechanism has an I-shaped cross section, including a clamping portion 4-1, a contact portion 4-2 and a connecting portion 4-3, and a clamping portion 4-1 and a contact portion 4-2 are respectively provided at both ends of the connecting portion 4-3, and the two contact portions 4-2 are electrically connected. The main body of the trigger mechanism can be made of plastic material, and a conductor is embedded inside to form mutually conductive contacts, which can be conveniently manufactured by injection molding, but is not limited to the above materials.

[0039] like Figure 4-5 As shown, the mounting end of the battery housing 1 is provided with an operation hole 12, and the housing on both sides of the operation hole 12 is provided with a thickened portion 11, and the inner side of the thickened portion 11 is provided with a retaining groove 9. For ease of manufacturing, the thickened portion and the retaining groove can be formed together with the battery housing. Before the battery pack is installed in the power tool, the engaging portion 4-1 of the trigger mechanism 4 is located in the retaining groove 9, so that the trigger mechanism 4 is kept inside the battery housing 1.

[0040] The electric tool is provided with an actuator 10 that cooperates with the trigger mechanism 4. After the battery pack is installed in the electric tool, the actuator 10 actuates the trigger mechanism 4 so that the trigger mechanism 4 contacts the partition portion 8, and the discharge circuit is in a connected state. The actuator 10 can be in any shape that is convenient for operation, and is preferably a rod-shaped member or a protrusion provided on the electric tool, and can also play a guiding role during installation. The engaging portion 4-1 is a convex spherical shape, and the retaining groove 9 is a concave spherical shape that cooperates therewith. The spherical fit between the engaging portion and the retaining groove can not only reliably keep the trigger mechanism inside the battery housing when not installed, but also can be easily disengaged during installation, and is convenient for re-engaging.

[0041] Reference Figure 5 The battery cell is a lithium-ion battery cell. Lithium batteries are more widely used and can be recharged and used repeatedly. In order to facilitate charging, a retaining mechanism (not shown in the drawings) can be provided in the battery housing 1. When the trigger mechanism 4 is actuated, the partition portion 8 is turned on. At this time, the trigger mechanism can be held in the on position by the retaining mechanism. Even if the battery pack is removed from the power tool, the trigger mechanism 4 remains in this position and will not move. This will facilitate charging and reuse of the battery pack. Moreover, the discharge circuit is allowed to remain in the on state because after the battery pack begins to be used, it will not be idle for a long time, and the risk of short circuit will be reduced.

[0042] In another embodiment, in order to facilitate the battery pack to be charged and used multiple times, a similar actuator may be provided on the charger to operate the trigger mechanism. In this case, the trigger mechanism may also include an elastic member (not shown) for restoring the trigger mechanism to the state before use by elastic force after the battery pack is removed from the power tool. This is undoubtedly conducive to improving the safety of the battery and preventing short circuits from occurring at any time. In addition, a guide member may be provided on the battery housing 1 to facilitate the movement of the trigger mechanism in a predetermined direction.

[0043] like Figure 1 , 4 As shown in FIG. 5 , the trigger mechanism 4 is located between the positive terminal 2 and the negative terminal 3, and the operating hole 12 faces the trigger mechanism 4. The trigger mechanism 4 can also be arranged on the side of the battery housing 1, which is not limited.

[0044] In some embodiments, a protective device is provided on the outside of the operation hole 12, such as an easily removable item such as tape, which can prevent dust and liquid from entering the battery housing before use, and can be torn off to expose the trigger mechanism when in use. When the trigger mechanism 4 is made of plastic, it also has a protective function, and in this case, no protective device may be provided.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A battery pack for an electric tool, characterized in that: The invention comprises a battery housing (1), wherein a plurality of groups of battery cells (5) are arranged in the battery housing (1), wherein each group of battery cells are connected in series to form a connection circuit, wherein the connection circuits are connected in series or in parallel to form a discharge circuit of a battery pack, and a partition (8) is provided on the connection circuit of each group of battery cells. The mounting end of the battery housing (1) is provided with a positive terminal (2) and a negative terminal (3), which are respectively connected to the positive electrode (7) and the negative electrode (6) of the discharge circuit of the battery pack connected in series or in parallel, and are used to connect to the positive and negative ends of an electric tool; the battery housing (1) is also provided with a trigger mechanism (4) for connecting the partition (8). Before the battery pack is installed on the electric tool, the trigger mechanism (4) is not in contact with the partition (8), and the discharge circuit is in a disconnected state. After the battery pack is installed on the electric tool, the trigger mechanism (4) is in contact with the partition (8), and the discharge circuit is in a connected state.

2. A battery pack for an electric tool according to claim 1, characterized in that: The trigger mechanism (4) has an I-shaped cross section and comprises a clamping portion (4-1), a contact portion (4-2) and a connecting portion (4-3); one clamping portion (4-1) and one contact portion (4-2) are respectively arranged at two ends of the connecting portion (4-3); and the two contact portions (4-2) are electrically connected.

3. A battery pack for an electric tool according to claim 2, characterized in that: An operating hole (12) is provided at the mounting end of the battery housing (1), thickened portions (11) are provided on the housing on both sides of the operating hole (12), and a retaining groove (9) is provided inside the thickened portion (11). Before the battery pack is mounted on the electric tool, the engaging portion (4-1) of the trigger mechanism (4) is located in the retaining groove (9), so that the trigger mechanism (4) is retained inside the battery housing (1).

4. A battery pack for an electric tool according to claim 3, characterized in that: The electric tool is provided with an actuating member (10) that cooperates with the trigger mechanism (4). After the battery pack is installed on the electric tool, the actuating member (10) actuates the trigger mechanism (4), so that the trigger mechanism (4) contacts the partition portion (8), and the discharge circuit is in a connected state.

5. A battery pack for an electric tool according to claim 4, characterized in that: The actuating member (10) is a rod-shaped member or a protruding portion arranged on the electric tool.

6. A battery pack for an electric tool according to any one of claims 1 to 5, characterized in that: The battery cell is a lithium ion battery cell.

7. A battery pack for an electric tool according to claim 3, characterized in that: The engaging portion (4-1) is in the shape of a convex sphere, and the retaining groove (9) is in the shape of a concave sphere matching therewith.

8. A battery pack for an electric tool according to claim 3, characterized in that: The trigger mechanism (4) is located between the positive terminal (2) and the negative terminal (3), and the operating hole (12) faces the trigger mechanism (4).

9. A battery pack for an electric tool according to claim 8, characterized in that: A protective device is arranged on the outer side of the operating hole (12).

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