Lithium battery pack for power tools and power tools

Abstract

The application discloses a lithium battery pack for electric tools and the electric tools, which comprises a tool body, a holding member, a locking device arranged on the holding member to lock the tool body to prevent it from rotating, and a battery pack arranged on the holding member and connected with the locked tool body through a switching device in the holding member to establish an electric power connection. The application provides the lithium battery pack for electric tools and the electric tools, when the tool is stuck and the reverse torque exceeds a preset value, the locking device is automatically unlocked, the tool body is twisted relative to the holding member, the conductive sheet is separated from the contact groove, the electric power connection is disconnected, and no electronic detection element is needed, so that the response is fast and the reliability is high.

Description

Technical Field

[0001] This invention relates to the field of power tool technology, and in particular to lithium battery packs for power tools and power tools. Background Technology

[0002] When a lithium-ion battery angle grinder jams during use, the machine body will experience a violent, momentary twist due to the reaction force of the motor torque. This recoil force can easily twist the user's hand, and is one of the common causes of injury from handheld power tools.

[0003] More seriously, because the lithium battery is directly mounted and fixed to the machine body, when the machine body twists and swings, the battery pack will be thrown out along with it, which can easily collide at high speed with the workpiece, the ground, or surrounding hard objects. After being subjected to a violent impact, the internal cells of the lithium battery may short-circuit or thermally run away, which may lead to fire or even explosion, causing serious personal injury and property damage.

[0004] Currently, the main protective measures against jerking and recoil fall into the following categories: incorporating a mechanical clutch in the transmission system to slip and release force under overload; using electronic sensors to detect anomalies and cut off power; or adding an auxiliary handle for the user to grip with both hands to counteract the recoil force. However, clutch response is delayed, electronic systems are at risk of failure, and auxiliary handles cannot eliminate the direct impact of recoil force on the arms. More importantly, none of these solutions change the fundamental structural element of "the battery being fixed to the body," meaning the risk of the battery being impacted by the body during swings remains.

[0005] Therefore, there is an urgent need for a comprehensive protection solution that can prevent users from twisting their hands, avoid battery impact damage at the source, and has a simple and reliable structure that does not rely on complex electronic controls. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a lithium battery pack for power tools and the power tool itself. This application separates the battery pack from the tool body by rotatably mounting the tool body onto a grip and then mounting the battery pack onto the grip, thus preventing the battery pack from twisting when the tool body is rotated.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a lithium battery pack for power tools and a power tool, comprising a tool body, a grip, wherein the tool body is rotatably mounted on the grip, and a locking device is provided on the grip to lock the tool body and prevent its rotation, and a battery pack mounted on the grip, wherein the battery pack is electrically connected to the locked tool body via an adapter within the grip. The locking device is an elastic lock; when the torsional force on the tool body exceeds the locking force, the locking device releases the lock on the tool body, causing it to twist relative to the grip and disconnecting the electrical connection.

[0008] Its beneficial effect is that when the tool jams or the anti-torque exceeds the preset value, the locking device automatically unlocks, the tool body twists relative to the grip, the conductive plate separates from the contact groove, the power connection is disconnected, no electronic detection element is required, and the response is fast and the reliability is high.

[0009] In the above scheme, preferably, the grip is provided with a handle for the user to hold, and a rotating shaft is fixedly provided on or around the rotation axis of the tool body and is rotatably mounted on the grip through the rotating shaft.

[0010] In the above scheme, preferably, the gripping member is provided with a mounting groove, the locking device is provided on the mounting groove, and a locking groove is provided on the tool body. The locking device is elastically guided and slidably provided with a locking head, which is inserted into the locking groove to lock the tool body on the gripping member.

[0011] In the above scheme, preferably, the locking groove is provided with a second inclined surface, and the locking head abuts against the second inclined surface to cause the tool body to jam. When the torsional force is greater than the locking force of the locking device, the locking head can slide out along the second inclined surface to release the locking of the tool body.

[0012] In the above scheme, preferably, the mounting groove is further provided with a conductive sheet, and the tool body is provided with a matching contact groove. When the tool body is locked, the conductive sheet and the contact groove are matched and connected to establish an electrical connection.

[0013] In the above scheme, preferably, the tool body is equipped with a protective device, the protective device including an airbag, the airbag being used to automatically inflate and deploy after the tool body is twisted relative to the grip, so as to form a buffer layer on the impact side of the tool body.

[0014] Its beneficial effect is that, while the main body is twisted, the relative displacement of the magnetic pull component is used to pull the switch component in a purely mechanical way, so that the airbag is inflated and deployed to form a buffer layer, and the secondary handle is unlocked and popped out, providing the operator with an additional grip point and effectively reducing the risk of injury.

[0015] In the above-described embodiment, preferably, a secondary handle is also included. The secondary handle is equipped with a guide member and is elastically guided to slide within a mounting hole in the tool body, and is locked in place by a locking device. The locking device is configured to automatically unlock after the tool body is twisted relative to the grip.

[0016] In the above scheme, preferably, the mounting groove is a C-shaped groove, and the tail of the tool body is located in the C-shaped groove and locked by the locking device. The mounting groove is provided with a first magnetic suction member, and a magnetic pull member is slidably arranged on the tool body in the C-shaped groove position. The magnetic pull member is magnetically connected to the first magnetic suction member, and the magnetic pull member is connected to the protective device and the locking device to unlock them after the tool body is twisted relative to the gripping member.

[0017] In the above scheme, preferably, the protective device includes a gas storage tank containing high-pressure gas, and a switch is elastically guided and slidably configured on the gas storage tank. The switch is connected to the rear end of a magnetic pull member via an elastic pull rope, so that the switch can be pulled to slide when the elastic pull rope is tightened, thereby inflating the airbag component from the gas storage tank.

[0018] In the above scheme, preferably, the locking device includes an elastic locking tongue, the rear end of which is connected to the switch via a pull rope, so that when the switch is pulled, the elastic locking tongue is simultaneously pulled back to retract the unlocking secondary handle, so that the secondary handle automatically pops out.

[0019] The beneficial effects of the present invention are as follows: The present invention provides a lithium battery pack and power tools for power tools. When the tool jams or the reverse torque exceeds a preset value, the locking device automatically unlocks, the tool body twists relative to the grip, the conductive sheet separates from the contact groove, and the power connection is disconnected. No electronic detection element is required, and the response is fast and the reliability is high. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram showing the disassembled parts of the present invention.

[0022] Figure 3 This is a cross-sectional view of the mounting slot location for the present invention.

[0023] Figure 4 This is a cross-sectional view of the present invention.

[0024] Figure 5 This is a partial enlarged view of the location of the protective component of the present invention.

[0025] Figure 6 This is a partial enlarged view of the location of the locking device of the present invention.

[0026] Figure 7 This is a schematic diagram of the gripping component of the present invention.

[0027] Figure 8 This is a partially enlarged view of the mounting position of the secondary handle of the present invention. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1:

[0029] See Figures 1-7 A lithium battery pack and power tools are used for power tools, including a tool body 1, a grip 2, and a battery pack 4. In this embodiment, the tool body 1 is an angle grinder. A coaxial line of the output shaft of the tool body 1 or a rotating shaft 11 parallel to the output shaft is provided around the output shaft. A shaft hole is provided on one end of the grip 2. The tool body 1 is rotatably mounted on the shaft hole of the grip 2 via the rotating shaft 11. To ensure that the two can rotate relative to each other, a bushing or bearing is provided on the shaft hole, and a limiting member is provided on the rotating shaft 11 to limit the grip 2 on the rotating shaft 11 so that the tool body 1 can rotate relative to the grip 2.

[0030] The grip 2 is provided with a handle 21 for the user to hold, and the secondary handle can be directly installed on the grip 2, so that when the tool body 1 is stuck and twisted, neither the left nor right hand will be twisted.

[0031] The other end of the gripper 2 is provided with a mounting groove 22, which is a C-shaped mounting groove. The tail of the tool body 1 can rotate into the mounting groove 22 from the opening of the C-shaped groove. The mounting groove 22 is elastically telescopically equipped with a locking device for locking the tool body 1, and a locking groove 13 is provided on the tail of the tool body 1 to cooperate with it.

[0032] The locking device specifically includes a locking head 31, a guide shell 32, and a first elastic element 33. The guide shell 32 is symmetrically fixed on the upper and lower end walls of the C-shape in the mounting groove 22. The locking head 31 is guided and slidably disposed within the guide shell 32. The first elastic element 33 is located on the bottom surface of the locking head 31 and the bottom surface of the inner cavity of the guide shell 32, so that the locking head 31 extends upward to the upper and lower end walls of the C-shape under the action of the first elastic element 33. When the tool body 1 abuts against the groove wall of the C-shaped groove on one side of its tail, and the locking groove 13 is aligned with the locking head 31, the locking head 31 abuts against the locking groove 13. Under the action of the first elastic element 33, the tool body 1 is locked, preventing it from rotating.

[0033] The battery pack 4 is detachably connected to the lower end of the grip 2, for example, by means of a slide rail on the battery pack housing engaging with a corresponding guide groove at the lower end of the grip 2, and being locked in place by a spring-loaded buckle. The battery pack 4 internally encapsulates multiple battery cells to provide electrical power.

[0034] A conductive sheet 221 is provided on the vertical end face of the mounting groove 22. The conductive sheet 221 is connected to the positive and negative terminals of the battery pack 4 fixedly mounted on the grip 2 through internal conductive lines. A contact groove 14 is provided at the tail of the tool body 1. When the tool body 1 is locked in the mounting groove 22, the contact groove 14 is inserted into the conductive sheet 221, thereby establishing a power connection between the battery pack 4 and the tool body 1.

[0035] The conductive sheet 221 is oriented towards the C-shaped opening, consistent with the direction in which the tool body 1 enters the mounting groove 22. Therefore, when the tool body 1 is in the locked position, the conductive sheet 221 is precisely inserted into the contact groove 14 and forms an electrical contact, establishing a power connection. When the tool body 1 rotates relative to the gripper 2 and deviates from this locked position, the contact groove 14 disengages from the conductive sheet 221, thereby breaking the power connection.

[0036] The locking groove 13 is a V-shaped groove with a second inclined surface 131 that faces the rotation direction of the tool body 1 and slopes downwards. The top of the locking head 31 is provided with a first inclined surface 311 that matches the second inclined surface 131. Under the action of the first elastic member 33, the first inclined surface 311 abuts against the second inclined surface 131, thereby locking the tool body 1. The critical torsional torque required for the locking head 31 to disengage from the locking groove 13 can be changed by selecting the elastic coefficient of the first elastic member and changing the inclination angle of the second inclined surface 131.

[0037] During normal operation, the critical torque is greater than the counter-torque of normal operation and greater than or equal to the torque of the mechanical clutch installed within the tool body 1, thus ensuring reliable locking of the tool body 1. When the output shaft of the tool body 1 is jammed, the tool body 1 experiences a large torsional force instantaneously, exceeding the critical torque. Simultaneously, the mechanical clutch within the tool body 1 remains engaged, causing the tool body 1 to rotate relative to the gripper 2. Guided by the second inclined surface 131, the locking head 31 compresses the spring and slides out of the locking groove 13, thereby releasing the lock on the tool body 1. This allows the tool body 1 to rotate independently, and simultaneously, the power connection between the tool body 1 and the battery pack 4 is disconnected, automatically placing the tool body 1 in a power-off state.

[0038] The tool body 1 is also equipped with a protective assembly for alignment and protection. The protective assembly includes a sealed high-pressure gas tank, a switch 172, and an airbag. The airbag is attached to the torsional side wall of the tool body 1 and is in a deflated state with all air removed. The high-pressure gas tank is located inside the tail of the tool body 1 and is connected to the airbag via a pipe. The switch 172 is elastically guided and slidably mounted on the connecting pipe. The switch 172 has a channel hole. When not pulled, under the action of elastic force, the channel hole and the pipe hole are misaligned, thus blocking the pipe. When the switch 172 is pulled, the channel hole and the pipe hole align, allowing gas from the high-pressure gas tank to enter the airbag, causing the airbag to rapidly inflate and form an air cushion on the impact side.

[0039] A first magnetic attractor 222 is fixed on the inner wall of the mounting groove 22. The first magnetic attractor 222 can be one or more permanent magnets. A magnetic puller 16 is also movably disposed on the tail of the tool body 1. The magnetic puller 16 is tapered and made of ferromagnetic metal. The outer end face of the magnetic puller 16 is flush with or extends beyond the tail side wall of the tool body 1. The rear end is connected to one end of the switch 172 through an elastic pull rope 171.

[0040] When the tool body 1 is in the locked state, the front end of the magnetic pull member 16 aligns with and is attracted to the first magnetic member 222. At this time, the elastic pull rope 171 is taut, while the switch member 172 has not yet been pulled. When the tool body 1 is twisted relative to the grip member 2, the first magnetic member 222 remains stationary with the grip member 2, and the magnetic pull member 16 is attracted to the first magnetic member 222 and does not move. As a result, the elastic pull rope 171 is stretched. During the stretching process, the switch member 172 is first pulled to slide, so that it overcomes the elastic force used to restrict it at the rear end and slides. Then, the channel hole and the pipe hole are aligned, and the gas in the high-pressure gas tank is introduced into the airbag, so that the airbag rapidly expands on the impact side to form an air cushion, thereby forming a buffer layer.

[0041] Meanwhile, as the elastic rope 171 is stretched, it provides the tool body 1 with an elastic tension opposite to the torsional force, thereby further relieving the force on the tool body 1.

[0042] Furthermore, when the tool becomes overloaded and jams, the tool body 1 first twists and cuts off the power, ensuring that the operator's hand is not twisted while preventing the battery pack 4 from rotating, thus avoiding the risk of the battery pack 4 being twisted and impacted. At the same time, the switch 172 is pulled open, triggering the airbag to deploy and forming an air cushion on the impact side, further protecting the tool body 1.

[0043] Its working principle or usage method is as follows: The user operates the tool body 1 by holding the handle 21. During normal operation, the tool body 1 is reliably locked by the locking device.

[0044] When the output shaft of tool body 1 is jammed, tool body 1 is subjected to a large torsional force instantaneously. At this time, the mechanical clutch located inside tool body 1 is not disengaged, and the torsional force on tool body 1 exceeds the critical torque of the locking device on tool body 1. Consequently, tool body 1 rotates relative to gripper 2. Under the guidance of the second inclined surface 131, locking head 31 compresses the spring and slides out of locking groove 13, thereby releasing the lock on tool body 1. This allows tool body 1 to rotate independently. Simultaneously with the rotation, the power connection between tool body 1 and battery pack 4 is disconnected, and tool body 1 automatically enters a power-off state.

[0045] When the tool body 1 is twisted relative to the grip 2, the first magnetic suction member 222 remains stationary with the grip 2, while the magnetic pull member 16 is attracted to the first magnetic suction member 222 and does not move. As a result, the elastic pull rope is stretched. During the stretching process, the switch member 172 is pulled to slide, so that it overcomes the elastic force used to limit it at the rear end and slides. Then the channel hole and the pipe hole are aligned, and the gas in the high-pressure gas tank is introduced into the airbag member, so that the airbag member expands rapidly on the impact side to form an air cushion, thereby forming a buffer layer to protect the tool body 1.

[0046] Example 2:

[0047] The difference between this embodiment and Example 1 lies in the type of tool body; all other aspects are the same.

[0048] The tool body 1 can also be used for other lithium-ion electric tools such as lithium-ion drills and lithium-ion wrenches. The rotation position of one end of the grip 1 is set on or near the output axis of the electric tool, and the other end is used to install the battery pack 4 and lock the tool body 1. When the anti-torsion device inside the tool body 1 fails, this device can automatically detach the tool body 1 from the grip 2.

[0049] Example 3:

[0050] The difference between this embodiment and Example 1 is the installation position of the secondary handle; all other aspects are the same.

[0051] See Figures 1-8The tool body 1 has a mounting hole, and the auxiliary handle 15 is provided with a guide 151. The auxiliary handle 15 is guided and slidably disposed in the mounting hole by the guide 151, so that the axial direction of the auxiliary handle 15 is restricted. One end of the third elastic member 153 is fixedly disposed on the end face of the guide 151, and the other end is inserted into the mounting hole during installation and abuts against the bottom surface of the mounting hole. Then, under the action of the third elastic member 153, the guide 151 can be pushed out of the mounting hole.

[0052] The guide member 151 is provided with a locking ring 154, and an elastic locking tongue 152 is provided on the side wall of the mounting hole for elastic guidance and sliding. The elastic locking tongue 152 has an inclined surface on one side facing outward from the mounting hole, while the other side is a straight wall. When the guide member 151 is pushed inward, it abuts against the inclined surface at the front end of the elastic locking tongue 152, causing it to elastically retract downward into the side wall of the mounting hole. When the locking ring 154 is aligned with it, it is then inserted upward into the locking ring 154 under the action of the elastic element at its lower end. Since the rear end is a straight surface, it cooperates with the locking ring 154 to lock the secondary handle 15.

[0053] The lower end of the elastic locking tongue 152 is connected to the switch plate 172 via a pull rope. When the switch plate 172 is pulled, the elastic locking tongue 152 is pulled downward, thereby locking the auxiliary handle 15. Under the action of the third elastic element 153, it is pushed out of the mounting hole, thereby disengaging the auxiliary handle 15 from the tool body 1. This prevents the auxiliary handle 15 from twisting when the tool body 1 is twisted, thus protecting the user.

[0054] Example 4:

[0055] This embodiment makes the following further improvements based on embodiment 1 or 3: the grip 2 is provided with a plurality of handles 21 or grip holes according to the distance from the output shaft of the tool body 1, and each handle 21 is provided with a pressure sensor to identify the user's grip position.

[0056] The locking head 31 is piston-slidably disposed inside the guide shell 32, and a closed cavity is formed between the rear end of the locking head 31 and the guide shell 32. The bottom of the guide shell 32 is provided with an air inlet and an air outlet, and the air inlet is connected to an air tank or an air filling device. Different air pressure values ​​are matched to the closed cavity according to different gripping positions, thereby changing the critical torsional torque required for the locking head 31 to disengage from the locking groove 13, thus automatically distributing different critical torsional torques to different gripping positions.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium battery pack for power tools and power tools, characterized in that: Includes the tool body (1); The tool body (1) is rotatably mounted on the grip (2), and a locking device is provided on the grip (2) to lock the tool body (1) and prevent it from rotating. Battery pack (4), which is mounted on grip (2) and establishes a power connection with locked tool body (1) through a converter in grip (2); The locking device is an elastic lock. When the torsional force of the tool body (1) is greater than the locking force, the locking device releases the lock on the tool body (1), causing it to twist relative to the grip (2) and disconnecting the power connection.

2. The lithium battery pack and power tool according to claim 1, characterized in that: The grip (2) is provided with a handle (21) for the user to hold. A rotating shaft (11) is fixedly provided on or around the rotation axis of the tool body (1) and is rotated on the grip (2) via the rotating shaft (11).

3. The lithium battery pack and power tool according to claim 1, characterized in that: The grip (2) is provided with a mounting groove (22), the locking device is provided on the mounting groove (22), and a locking groove (13) is provided on the tool body (1). The locking device is provided with a locking head (31) that is elastically guided and slidably provided. The locking head (31) is inserted into the locking groove (13) to lock the tool body (1) on the grip (2).

4. The lithium battery pack and power tool according to claim 3, characterized in that: The locking groove (13) is provided with a second inclined surface (131), and the locking head (31) abuts against the second inclined surface (131) to cause the tool body (1) to jam. When the torsional force is greater than the locking force of the locking device, the locking head (31) can slide out along the second inclined surface (131) to release the locking of the tool body (1).

5. The lithium battery pack and power tool according to claim 3, characterized in that: The mounting slot (22) is also equipped with a conductive sheet (221), and the tool body (1) is provided with a matching contact groove (14). When the tool body (1) is locked, the conductive sheet (221) and the contact groove (14) are matched and connected to establish an electrical connection.

6. The lithium battery pack and power tool according to claim 1, characterized in that: The tool body (1) is provided with a protective device, which includes an airbag. The airbag is used to automatically inflate and deploy after the tool body (1) is twisted relative to the grip (2) to form a buffer layer on the impact side of the tool body (1).

7. The lithium battery pack and power tool according to claim 6, characterized in that: It also includes a secondary handle (15), on which a guide (151) is provided, and is elastically guided and slidably disposed in the mounting hole opened in the tool body (1) by the guide (151), and is locked by a locking device; The locking device is configured to automatically unlock after the tool body (1) is twisted relative to the grip (2).

8. The lithium battery pack and power tool according to claim 6, characterized in that: The mounting slot (22) is a C-shaped slot, and the tail of the tool body (1) is located in the C-shaped slot and locked by the locking device; The mounting slot (22) is provided with a first magnetic suction member (222). The tool body (1) is slidably configured with a magnetic suction pull member (16) in the C-shaped slot. The magnetic suction pull member (16) is magnetically connected to the first magnetic suction member (222), and the magnetic suction pull member (16) is connected to the protective device and the locking device to unlock the tool body (1) after it is twisted relative to the grip (2).

9. The lithium battery pack for power tools and the power tool according to claim 8, characterized in that: The protective device includes a gas storage tank () containing high-pressure gas, and a switch (172) is elastically guided and slidably disposed on the gas storage tank () and the switch (172) is connected to the rear end of the magnetic pull member (16) by an elastic pull rope, so as to pull the switch (172) to slide when the elastic pull rope is tightened, so that the gas storage tank () inflates the airbag.

10. The lithium battery pack for power tools and the power tool according to claim 9, characterized in that: The locking device includes an elastic locking tongue (152), the rear end of which is connected to the switch (172) via a pull rope, so that when the switch (172) is pulled, the elastic locking tongue (152) is pulled back to retract the unlocking secondary handle (15), so that the secondary handle (15) automatically pops out.

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