WO2015180391A1

WO2015180391A1 - Battery pack charging/discharging system and method for electric tool, and electric tool

Info

Publication number: WO2015180391A1
Application number: PCT/CN2014/089316
Authority: WO
Inventors: 翁磊
Original assignee: 浙江明磊工具实业有限公司
Priority date: 2014-05-30
Filing date: 2014-10-23
Publication date: 2015-12-03
Also published as: CN104065116A

Abstract

A battery pack charging/discharging system and method for an electric tool, and an electric tool. The battery pack charging/discharging system comprises a battery pack (100) and a charging dock (200), wherein a plurality of independently arranged batteries (110) are arranged in the battery pack (100), and both the positive electrode and the negative electrode of each battery are led out; and a parallel circuit (400) for charging the positive electrode and the negative electrode of each battery in parallel is formed in the charging dock (200), and a series circuit (500) for discharging the positive electrode and the negative electrode of each battery in series is formed in an electric tool (300). In the battery pack charging/discharging system, batteries in a battery pack are independently arranged, the batteries are connected in series when large-current discharging is needed, and the batteries are connected in parallel when charging is needed. When the charging voltage of the battery pack needs to be detected, there is no need to arrange a complicated detection circuit or sampling circuit.

Description

Battery pack charging and discharging system, method and power tool for power tool

Technical field

The present invention relates to the field of power tools, and in particular, to a battery pack charging and discharging system, a method, and a power tool for a power tool.

Background technique

Power tools, such as electric drills, electric screwdrivers, etc., typically have a battery pack that includes a plurality of chargeable and dischargeable dry batteries or lithium batteries. When the power tool is operated, a large current is required, so the batteries in the battery pack of the existing power tool are connected in series.

For example, the Chinese patent "charging device, and a combination of a charging device and a battery pack" disclosed in CN201266846 indicates that the battery pack includes a plurality of batteries, a positive terminal and a negative terminal disposed in series with the battery, and an electronic control unit connected to the battery, And a status indicating terminal connected to the electronic control unit. The above patents indicate that several cells within the battery pack are connected in series.

Further, as disclosed in Chinese Patent No. CN1967964, "Rechargeable Battery Module for Power Tools", it is pointed out that the battery assembly (20) is composed of a plurality of secondary batteries (21-24) connected in series, and a pair of battery packs. Output terminals (31, 32) are coupled to the battery pack to provide current to the battery pack for operating the power tool. The above patents also explicitly indicate that several cells within the battery pack are connected in series.

Since the batteries in the battery pack are connected in series when discharged, for convenience, the batteries are also connected in series when charging.

However, when the battery connected in series in the battery pack is used for charging, if one battery fails, the charging voltage of the other battery changes, so the charging voltage of each battery needs to be detected in real time, and the battery voltage of each battery in series is It is not necessary to set up a complicated detection circuit for detecting the state of charge when the battery in the battery pack is charged.

Summary of the invention

The technical problem to be solved by the present invention is that, in view of the above-mentioned deficiencies of the prior art, a battery pack charging and discharging system that facilitates voltage detection during charging without affecting discharge current during discharge is proposed.

The technical solution adopted by the present invention is to provide a battery pack charging and discharging system for a power tool, comprising a battery pack and a charging base, wherein the battery pack is provided with a plurality of independently arranged batteries, each of which is provided The positive and negative electrodes of the battery are all led out; a parallel circuit for charging the positive and negative electrodes of each battery in parallel is formed in the charging base; and a series circuit for discharging the positive and negative electrodes of each battery in series is formed in the power tool.

Further, the positive and negative electrodes of each battery lead two pairs of positive and negative leads, wherein a pair of positive and negative leads are electrically connected to a parallel circuit in the charging stand, and the other pair of positive and negative leads are electrically connected to a series circuit in the power tool.

Further, the positive and negative poles of each battery lead out a pair of positive and negative leads, and when the battery is discharged, the positive and negative leads are electrically connected with a series circuit in the power tool, and when the battery is charged, the positive and negative leads are charged and charged. The parallel circuit in the seat is electrically connected.

Further, the parallel circuit and the series circuit are printed on the PCB circuit board.

Further, the charging and discharging system further includes a plurality of pairs of metal domes, and metal pins that are insertably fixed between each pair of metal domes; the positive and negative electrodes are connected to corresponding metal domes, and the plurality of metal pins are connected to Series circuit or parallel circuit.

Further, the battery is a lithium battery or a dry battery.

The invention also provides a battery pack charging and discharging method for a power tool, comprising the steps of:

Leading the positive and negative electrodes of each battery in the battery pack;

When charging, the positive and negative poles of each battery in the battery pack are connected in parallel and then connected to the rechargeable battery pack for charging;

When discharging, connect the positive and negative poles of each battery in the battery pack in series and connect to Power tool power mechanism.

The present invention also provides a power tool including a handle-shaped casing having an opening at a bottom thereof, the battery pack being located in the opening and causing the casing and the battery pack to form a closed casing; a plurality of independently arranged batteries, wherein the casing or the battery pack is further provided with a series circuit in which a plurality of independently arranged batteries are connected in series; and a charging base, wherein the charging base is provided with a plurality of independent A parallel circuit in which the positive and negative terminals of the battery are connected in parallel.

Further, the parallel circuit is electrically connected to the external battery pack through the battery pack plug.

Further, the power tool is an electric drill or an electric screwdriver.

The invention integrates the batteries in the battery pack independently, and needs to provide a large current discharge to connect the batteries in series, and when charging is required, the batteries are connected in parallel. After the parallel connection, the voltages of the batteries are the same. When it is necessary to detect the charging voltage of the battery pack, it is not necessary to set a complicated detection circuit and sampling circuit. At the same time, the present invention does not require any change to the external structure of the existing power tool and the charging stand, and is highly adaptable.

DRAWINGS

1 is a schematic structural view of a battery pack charging and discharging system for a power tool according to a preferred embodiment of the present invention;

2 is a schematic exploded view of a portable hand drill according to a preferred embodiment of the present invention;

3 is a schematic exploded view of a lithium electric two-speed electric drill according to a preferred embodiment of the present invention.

detailed description

The technical solutions of the present invention are further described below with reference to the accompanying drawings, but the present invention is not limited to the embodiments.

Please refer to FIG. 1. FIG. 1 is a schematic structural diagram of a battery pack charging and discharging system for a power tool according to a preferred embodiment of the present invention. In FIG. 1, the battery pack charging and discharging system includes a battery pack 100, a charging stand 200, and a battery pack. Applied to the power tool 300. Battery A plurality of independently arranged batteries 110 are disposed in the package. The positive and negative poles of each battery 110 are taken out; a parallel circuit 400 for charging the positive and negative electrodes of each battery 110 in parallel is formed in the charging base 200; and the positive and negative of each battery is formed in the power tool 300. A series circuit 500 of series discharges.

The independent setting described herein means that the batteries in the battery pack are neither connected in series nor connected in parallel, but are in an electrically isolated state from each other.

Referring to FIG. 1 , in FIG. 1 , the positive and negative poles of each battery 110 lead to two pairs of positive and negative leads, wherein a pair of positive and negative leads are connected in series to each other to form a series circuit 500 for the power tool. The power mechanism provides a power source, and the other pair of positive and negative leads are connected in parallel to each other to form a parallel circuit 400. The positive and negative ends of the parallel circuit 400 are connected to the rechargeable battery pack for charging the plurality of batteries 110.

The circuit structure in FIG. 1 can be directly printed on the PCB circuit board to make the entire circuit structure more tidy. Of course, in order to save cost, the above circuit structure can also be directly implemented by using wires.

More preferably, the above circuit structure can be realized by means of metal domes and metal pins. That is, the charging and discharging system further includes a plurality of pairs of metal domes, and metal pins that are insertably fixed between each pair of metal domes; the positive and negative electrodes are connected to corresponding metal domes, and the plurality of metal pins are connected to the series circuit Or parallel circuits.

The combination of metal domes and metal pins allows the combination of circuit and mechanical fastening to save space and cost.

In some power tools, when the charging stand and the battery pack are independently set, it is not necessary to cause the battery in the battery pack to simultaneously draw two sets of positive and negative leads, and only one set of positive and negative leads need to be taken out, when the charging stand is combined with the battery pack. When charging the battery in the battery pack, the contacts of the parallel circuit in the charging base can be combined with the positive and negative leads.

The above-described line direction in Fig. 1 is only used to indicate the configuration of an embodiment of the parallel circuit and the series circuit, and does not indicate that the line direction of the parallel circuit and the series circuit is actually the same. In actual use, the line direction can be adjusted according to the internal structure of different power tools, and for the electromagnetic compatibility requirements of the circuit, it is also possible to add such as on the line. Electrical components such as resistors, capacitors, and inductors.

The battery of this embodiment may be a common battery such as a lithium battery or a dry battery.

In this embodiment, the batteries are connected in parallel during charging, which can conveniently detect the charging voltage of the battery without setting up a complicated detection circuit and sampling circuit.

When discharging, the positive and negative electrodes of each battery in the battery pack are connected in series and connected to the power tool power mechanism.

Referring to FIG. 2, the present invention further provides a power tool. In the embodiment, the power tool is a portable hand drill, which comprises a hollow casing 10 and a battery assembled by a left casing and a right casing. The bag 20, a switch mechanism 30, a motor 40, a gearbox mechanism, a center shaft 60, a rotary button 70 for controlling the motor 40 to be reversed, a red light pipe 80, and an elastic member connected to the rotary button 70 90. A charging interface 100 electrically connected to the battery pack 20.

The battery pack 20 is a rechargeable battery pack. The charging and discharging system in the battery pack is the charging and discharging system described above.

An outer surface of the vertically extending portion of the casing 10 is convexly provided with an anti-slip portion 11 made of a flexible material. The anti-slip portion 11 is arranged to enable the user to better handle the portable hand drill 1, which is more stable in operation; prevents the user from slipping during use, and effectively improves the safety of the portable hand drill 1 when used. The red light emitting tube 80, the switch mechanism 30 and the battery pack 20 are electrically connected in a loop. Setting the red light-emitting tube 80 can more intuitively display the working state of the portable hand drill 1 to avoid a safety accident. The motor 40 has an output shaft (not shown) and a motor gear 41 fixed to the output shaft. The rotary button 70, the push rod, the motor 40 and the battery pack 20 are electrically connected in a loop. The battery pack 20, the switch mechanism 30, the motor 40, The transmission mechanism and the center shaft 60 are housed in the casing 10. The center shaft 60, the gearbox mechanism and the motor 40 are coupled in sequence. The distal end of the central motor 60 at the distal end of the motor 40 is provided with a fixing hole (not shown) extending through the end surface thereof. The near motor 40 end of the center shaft 60 has a disk shape and extends toward the motor 40 to form three first connecting posts 61 arranged at equal intervals along the circumference. A central portion of the central shaft 60 is recessed to form a first recess 62.

The gearbox mechanism includes a transmission case 51 that is hollow and open at both ends, a center frame 52, three first gears 53, three second gears 54, a snap ring 55 having an open ring shape, and a The disc-shaped end caps 56 are both annular first spacers 57 and second spacers 58. The first spacer 57 is disposed between the snap spring 55 and the transmission case 51, and the second spacer 58 is disposed between the end cover 56 and the transmission case 51. The first spacer 57 and the second spacer 58 are provided to protect the circlip 55, the transmission case 51 and the end cover 56, thereby reducing the number of maintenance and prolonging the service life of the portable hand drill 1. The near motor 40 end of the transmission case 51 is provided with two oppositely disposed holding grooves (not shown). A third gear 521 is disposed at the end of the center frame 52 near the central axis 60. The second central connecting rod 522 is disposed at the distal center shaft 60 end of the center frame 52. The end cap 56 has a through hole 561 extending therethrough, and an outer side of the end cap 56 is formed with two lugs 562 disposed opposite to each other and corresponding to the retaining groove. The central shaft 60 is inserted into the transmission case 51. The circlip 55 is engaged in the first recess 62 and abuts against the end surface of the distal end of the gearbox housing 51. The first gear 53 respectively The third gear 521 is disposed in the middle of the first gear 53 and meshes with the first gear 53 . The second gear 54 is respectively fixed on the second connecting post 522 . The end cover 56 is disposed at the end of the motor case 51 of the transmission case 51, and the lug 562 is locked in the holding groove; the motor gear 41 is disposed in the middle of the second gear 54 through the through hole 561 and The second gear 54 meshes.

When using the portable hand drill 1, the operator first assembles the corresponding batch head on the fixing hole of the center shaft 60, and then starts the portable hand drill 1 through the switch mechanism 30, and the motor 40 starts to start, and the motor gear 41 is driven. Starting to rotate, the power of the motor 40 passes through the motor gear 41, the second gear 54, the third gear 521, and the first The gear 53 is finally transmitted to the central shaft 60, causing the central shaft 60 to start to rotate, thereby driving the bit to start the rotating work. When it is necessary to change the rotation direction of the motor 40, the rotation button 70 is applied. Under the action of the rotary button 70, the switch mechanism 30 drives the motor 40 to start reverse rotation. As with the above principle, the batch head starts to reverse the operation. . The elastic member 90 is provided in order to stabilize the state of the rotary button 70, prevent the motor 40 from suddenly reversing from the positive transition, and improve the safety of the portable hand drill 1 when it is used.

The portable hand drill 1 is provided with the position of the center shaft 60, the gearbox mechanism and the motor 40. The center shaft 60 not only has the function of the shaft but also the function of the drill chuck, so the portable hand drill 1 is not only omitted. Generally, the components of the drill chuck required for the hand drill are compact and reasonable, and the screws are basically not needed. Only the structure of the component itself is used for assembly and positioning, which is convenient for disassembly and assembly, and can be repaired without screwing a large number of screws. It also eliminates the trouble of screwing down and losing, which brings great convenience to the user.

Referring to FIG. 3, the power tool of the battery pack charging and discharging system of the present invention is a lithium electric two-speed electric drill, and the lithium electric two-speed electric drill comprises a casing 7' with a vent, an electric drill body and an electric connection. The handle portion, the electric drill body includes a motor 6' installed in the casing 7', a torque sleeve 3' installed at the front end of the casing 7', and a drill chuck 1', a drill chuck 1' and a torque sleeve 3' A gearbox assembly 2' is axially mounted therebetween, and a transmission gear is disposed in the gearbox assembly 2'. A torque ring 4' for changing the magnitude of the torque is mounted in the torque sleeve 3'. The output shaft is axially coupled to the gearbox assembly 2', and a motor gear 5' is fitted over the output shaft of the motor 6', the motor gear 5' being in mesh with the toothing of the transmission gear; the casing A shifting button 14' is mounted on the top surface of the 7' through the shifting wire 15', a T-shaped groove is provided at the tail of the top surface of the casing 7', and horizontal and vertical horizontal bubbles 13 are installed in the T-shaped groove. '.

The handle portion includes a switch assembly 9' of the electric drill, a battery pack 8' and a bit holder 17', and the bit holder is disposed on the lower end surface of the handle portion, and the groove for preventing the bit is opened on the bit holder; a bottom surface of the handle portion is mounted with a PCB board 18', and the battery pack is mounted The bottom surface of the handle portion is electrically connected to the PCB board; the switch assembly is mounted on the upper end of the handle portion front casing 11' and is electrically connected to the PCB board.

The front cover 11' of the handle portion is further mounted with an illumination lamp 16' and electrically connected to the PCB board; the rear sleeve 12' of the handle portion is further provided with a push rod 10' for controlling the forward and reverse rotation of the motor; The battery pack uses a lithium battery and is also equipped with a lithium battery charger 19'.

The specific embodiments described herein are merely illustrative of the spirit of the invention. A person skilled in the art can make various modifications or additions to the specific embodiments described or in a similar manner, without departing from the spirit of the invention or as defined by the appended claims. The scope.

Claims

A battery pack charging and discharging system for a power tool, comprising: a battery pack and a charging base, wherein the battery pack is provided with a plurality of independently arranged batteries, and the positive and negative poles of each battery are led out; A parallel circuit for charging the positive and negative electrodes of each battery in parallel is formed in the charging base; and a series circuit for discharging the positive and negative electrodes of each battery in series is formed in the power tool.
The battery pack charging and discharging system according to claim 1, wherein each of the positive and negative electrodes of the battery leads to two pairs of positive and negative leads, wherein a pair of positive and negative leads are electrically connected to a parallel circuit in the charging stand, and A pair of positive and negative leads are electrically connected to the series circuit in the power tool.
The battery pack charging and discharging system according to claim 1, wherein a positive and negative electrode of each battery leads to a pair of positive and negative leads, and when the battery is discharged, the positive and negative leads and the electric circuit in the electric tool are connected in series. Connected, when the battery is charged, the positive and negative leads are electrically connected to a parallel circuit in the charging cradle.
The battery pack charging and discharging system according to claim 2 or 3, wherein the parallel circuit and the series circuit are printed on the PCB circuit board.
The battery pack charging and discharging system according to claim 2 or 3, wherein the charging and discharging system further comprises a plurality of pairs of metal domes, and metal pins that are insertably fixed between each pair of metal domes; The negative lead is connected to a corresponding metal dome, and the plurality of metal pins are connected to a series circuit or a parallel circuit.
The battery pack charging and discharging system according to claim 1, wherein the battery is a lithium battery or a dry battery.
A battery pack charging and discharging method for a power tool, comprising: the steps of:

Leading the positive and negative electrodes of each battery in the battery pack;

When charging, connect the positive and negative poles of each battery in the battery pack in parallel and connect to the charging power source for charging;

When discharging, the positive and negative electrodes of each battery in the battery pack are connected in series and connected to the power tool power mechanism.
A power tool comprising: a handle-shaped casing, the bottom of the casing having an opening, the battery pack being located in the opening and the casing and the battery pack forming a closed casing; the battery pack is provided with a plurality of a separately arranged battery, the casing or the battery pack is further provided with a series circuit connecting a plurality of independently arranged batteries with a positive pole and a negative pole; and a charging base, wherein the charging seat is provided with a plurality of independent settings The battery is connected in parallel with the positive and negative terminals of the battery.
The electric power tool according to claim 8, wherein said parallel circuit is electrically connected to an external power source through a power plug.