Electric tool

Abstract

An electric tool (100), comprising an adjustment sleeve (4), wherein the adjustment sleeve (4) has a first arm of force (41), by means of which a transmission arm (311) is driven to rotate and a mode switching member (31) is moved from a first position to a second position; the adjustment sleeve (4) further has a second arm of force (42); when the mode switching member (31) is maintained at the first position, the transmission arm (311) and the second arm of force (42) are misaligned in an axial direction, such that when the adjustment sleeve (4) rotates, the second arm of force (42) cannot come into contact with the transmission arm (311); and when the mode switching member (31) is maintained at the second position, the transmission arm (311) moves to axially overlap with the second arm of force (42), such that when the adjustment sleeve (4) is rotated in a direction opposite a first direction, the second arm of force (42) drives the mode switching member (31) to rotate, thereby preventing a torsion spring (34) from not being able to get the mode switching member (31) of the electric tool (100) reset due to excessive circumferential resistance, and thus ensuring that the electric tool (100) can be smoothly switched from an impact gear back to a drilling gear.

Description

power tools Technical Field

[0001] This application relates to the field of power tool technology, and in particular to mode switching mechanisms for power tools. Background Technology

[0002] An impact drill is a type of power tool that has two functional modes: drill mode and impact mode, depending on the operational requirements. In drill mode, the output shaft of the impact drill only outputs torque, while in impact mode, the output shaft outputs torque and also reciprocates along its axis, achieving the impact function. Switching between the two functional modes is generally achieved by rotating an adjusting sleeve. For example, rotating the adjusting sleeve forward causes the mode switching component inside the impact drill to rotate and retract a certain distance, thus providing axial space for the output shaft to reciprocate, at which point the impact drill enters impact mode. When the adjusting sleeve is rotated in the reverse direction, the adjusting sleeve removes the limiting effect on the mode switching component, and the torsion spring inside the impact drill drives the mode switching component to rotate in the opposite direction and return to its original position, at which point the impact drill enters drill mode.

[0003] However, when the aforementioned impact drill switches from impact mode to drill mode by rotating the adjusting sleeve, the axial force of the torsion spring is too large, which causes the circumferential friction of the mode switching component to be too large or other resistance. This prevents the circumferential torque of the torsion spring from driving the mode switching component to rotate in the opposite direction and move forward to complete the reset, thus preventing the impact drill from switching from impact mode to drill mode. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a power tool that solves the problem that the mode switching mechanism of the power tool cannot rotate in the opposite direction and move forward to complete the reset due to excessive circumferential resistance, thus failing to ensure that the power tool can smoothly switch from impact mode back to drilling mode.

[0005] Therefore, this application provides the following technical solution: an electric tool, comprising:

[0006] chassis;

[0007] The output shaft is rotatably supported within the housing.

[0008] An impact mechanism includes a mode switching component, a movable ratchet fixed to the output shaft, and a stationary ratchet fixed to the housing and disposed opposite to the movable ratchet. The mode switching component can move along the axial direction of the output shaft to a first position and a second position. When the mode switching component moves to the first position, it prevents the stationary ratchet from engaging with the movable ratchet. When the mode switching component moves to the second position, it allows the stationary ratchet to engage with the movable ratchet.

[0009] An adjustment sleeve is rotatably supported on the housing and located on the outer periphery of the mode switching component. The adjustment sleeve has a first lever arm, and the mode switching component has a transmission arm that can abut against the first lever arm. When the adjustment sleeve is rotated in a first direction, the first lever arm drives the transmission arm to rotate and moves the mode switching component from a first position to a second position.

[0010] The adjusting sleeve also has a second lever arm;

[0011] When the mode switching component is held in the first position, the transmission arm and the second force arm are misaligned in the axial direction, and when the adjusting sleeve rotates, the second force arm cannot contact the transmission arm;

[0012] When the mode switching component is held in the second position, the transmission arm moves to overlap with the second lever arm axially, and rotates the adjusting sleeve in a direction opposite to the first direction, causing the second lever arm to drive the mode switching component to rotate.

[0013] A further improvement is that the first lever arm and the second lever arm are protrusions extending from the inner wall of the adjusting sleeve to the mode switching component;

[0014] The transmission arm is a protrusion extending from the outer wall of the mode switching component to the adjustment sleeve. The first lever arm and the second lever arm abut against the side wall of the transmission arm to drive the transmission arm to rotate.

[0015] A further improvement is that the axial distance between the first lever arm and the front end of the adjusting sleeve is less than the axial distance between the second lever arm and the front end of the adjusting sleeve.

[0016] A further improvement is that the circumferential distance between the first lever arm and the second lever arm is greater than or equal to the width of the transmission arm.

[0017] A further improvement is that the side wall of the housing is formed with a circumferentially extending receiving groove, the receiving groove having a first depth portion and a second depth portion, and the depth of the second depth portion is greater than the depth of the first depth portion.

[0018] The mode switching component has a guide arm extending toward the receiving groove, the guide arm being held in the receiving groove;

[0019] When the guide arm is held at the first depth, the mode switching component is held at the first position;

[0020] When the guide arm is held at the second depth, the mode switch is held at the second position.

[0021] A further improvement is as follows: a cover plate is connected to the front end of the housing, and a guide portion extending toward the guide arm is provided on the cover plate. The guide portion is disposed opposite to the receiving groove. The guide portion has a first height portion and a second height portion and a sliding portion located between the first height portion and the second height portion. The height of the second height portion protruding from the cover plate is greater than the height of the first height portion.

[0022] The guide arm is driven by the adjusting sleeve to move along the extension direction of the guide portion;

[0023] When the guide arm moves to the first height, the mode switching component remains in the first position;

[0024] When the guide arm moves to the second height, the mode switching component remains in the second position.

[0025] A further improvement is as follows: the power tool includes a torsion spring, one end of which directly or indirectly abuts against the housing, and the other end abuts against the mode switch to drive the mode switch to reset from the second position to the first position;

[0026] When the mode switching component moves from the first position to the second position, the torsion spring is further compressed in the axial and circumferential directions;

[0027] When the mode switching component moves from the second position to the first position, the torsion spring releases its compressive force and pushes the guide arm to slide along the sliding part.

[0028] A further improvement is that one end of the torsion spring abuts against the stationary ratchet, and the other end abuts against the inner wall of the mode switching component.

[0029] A further improvement is that the housing has a large-diameter portion and a small-diameter portion, the large-diameter portion being used to house the gear set, and the small-diameter portion being used to house the impact mechanism.

[0030] A further improvement is that the adjusting sleeve is rotatably supported on the small diameter portion.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] This application provides a power tool in which a first lever arm and a second lever arm are axially misaligned on the inner wall of an adjusting sleeve. When the user rotates the adjusting sleeve forward, the first lever arm drives the mode switching component to rotate and move axially backward. At the same time, the second lever arm and the mode switching component are axially misaligned, so they cannot contact each other. The forward rotation of the adjusting sleeve is not affected, and the power tool can be smoothly switched from drill mode to impact mode. During the reverse rotation of the adjusting sleeve, since the mode switching component has moved axially backward to a second position where it can overlap with the second lever arm axially, the second lever arm can drive the mode switching component to rotate in the reverse direction. This avoids the torsion spring failing to reset the mode switching component due to excessive circumferential resistance of the mode switching mechanism, thereby ensuring that the power tool can be smoothly switched from impact mode back to drill mode. Attached Figure Description

[0033] Figure 1 is a schematic diagram of the structure of the power tool in a preferred embodiment of this application;

[0034] Figure 2 is a cross-sectional view of the power tool shown in Figure 1;

[0035] Figure 3 is a partial cross-sectional view of the power tool shown in Figure 1 in the screw position;

[0036] Figure 4 is a partial cross-sectional view of the power tool shown in Figure 1 in impact mode;

[0037] Figure 5 is an exploded view of the internal components of the power tool shown in Figure 1;

[0038] Figure 6 is a schematic diagram of the adjustment sleeve, mode switching component, and adjustment nut of the power tool shown in Figure 1;

[0039] Figures 7a-7c show the relative position changes of the first lever arm, the second lever arm, and the mode switching component of the power tool shown in Figure 1 when switching from screw mode to impact mode.

[0040] Figures 8a-8c are top views of the relative position changes of the first lever arm, the second lever arm, and the mode switching component of the power tool shown in Figure 1 when switching from screw mode to impact mode.

[0041] Figure 9 is a schematic diagram of the cooperation structure between the guide arm and the cover plate of the power tool shown in Figure 1 in screw mode and drill mode.

[0042] Figure 10 is a schematic diagram of the cooperation structure between the guide arm and the cover plate of the power tool shown in Figure 1 in the impact mode.

[0043] Figure 11a is a schematic diagram of the structure of the second lever arm and the clearance groove of the power tool shown in Figure 1 when they are closest;

[0044] Figure 11b is a schematic diagram of the structure of the second lever arm and the clearance groove of the power tool shown in Figure 1 when they begin to disengage.

[0045] Figure 12 is a cross-sectional view of the adjustment sleeve and adjustment nut assembly of the power tool shown in Figure 1;

[0046] Figure 13 is a top view of the adjusting nut of the power tool shown in Figure 1.

[0047] Explanation of reference numerals in the attached drawings: 100, power tool; 1, housing; 11, receiving groove; 111, first depth section; 112, second depth section; 12, large diameter section; 13, small diameter section; 2, output shaft; 3, impact mechanism; 31, mode switching component; 311, transmission arm; 312, guide arm; 32, moving ratchet; 33, stationary ratchet; 34, torsion spring; 35, bearing; 4, adjusting sleeve; 41, first lever arm; 42, second lever arm; 43, internal thread; 5, motor; 6, clutch mechanism; 61, locking pin; 62, steel ball; 7, torque adjustment mechanism; 71, adjusting nut; 711, clearance groove; 712, external thread; 713, limiting notch; 714, connecting post; 72, elastic element; 8. Cover plate; 81. Guide section; 811. First height section; 812. Second height section; 813. Sliding section; 9. Transmission mechanism; 91. Planetary gear set; 911. Planetary gear; 912. Planetary carrier; 913. Internal gear ring; 914. Limiting protrusion. Detailed Implementation

[0048] The terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the application. For example, terms such as "upper," "lower," "front," and "rear" that indicate orientation or positional relationship are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the application and simplifying the description, and are not intended to indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the application.

[0049] The specific embodiments of this application will be described below with reference to the accompanying drawings.

[0050] This invention provides an electric tool 100, specifically an impact drill, as shown in Figures 1 and 2. The electric tool 100 includes a housing 1 and, arranged sequentially along the output direction, a motor 5, a transmission mechanism 9, a clutch mechanism 6, a torque adjustment mechanism 7, an adjustment sleeve 4, an impact mechanism 3, and an output shaft 2. The housing 1 includes a handle for gripping and a cylindrical barrel, the rear half of which is a large-diameter section 12, and the front half is a small-diameter section 13. Power is provided by the motor 5 and transmitted to the output shaft 2 via the transmission mechanism 9. During transmission, the clutch mechanism 6 enables the electric tool 100 to operate in screw mode, the torque adjustment mechanism 7 enables the setting of different torques for screw mode, and the impact mechanism 3 enables the electric tool 100 to operate in impact mode. The adjustment sleeve 4 is rotatably supported on the small-diameter section 13, and by rotating the adjustment sleeve 4, the electric tool 100 can be cyclically switched between screw mode, drill mode, and impact mode.

[0051] To facilitate a clear explanation of the specific content of the technical solution of this invention, the following definitions are made: the rotation axis 101 of the output shaft 2 and the direction parallel to it are defined as the axial direction; the radial direction of the circumference with the rotation axis 101 of the output shaft 2 as the central axis is defined as the radial direction; the output direction of the output shaft 2 is defined as the forward direction; and the direction opposite to the output direction of the output shaft 2 is defined as the rearward direction.

[0052] As shown in Figure 2, the motor 5 is housed in the large-diameter portion 12 of the housing 1. It can be powered by a power source to rotate the rotor inside, and the power is transmitted forward by the transmission mechanism 9 which is connected to the rotor. As shown in Figures 3, 4, and 5, the transmission mechanism 9 may include one or more stages of planetary gear sets 91, which include multiple planetary gears 911 connected to the rotor, a planet carrier 912 supporting the planetary gears 911, and an internal gear ring 913 meshing with the multiple planetary gears 911. The foremost planet carrier 912 is connected to the output shaft 2 to transmit power.

[0053] Referring to Figures 3, 4, and 5, the clutch mechanism 6 is housed in the large-diameter portion 12 of the housing 1. It interrupts the transmission connection between the motor 5 and the output shaft 2 when the power tool 100 reaches the clutch torque by releasing the circumferential rotational lock on the internal gear ring 913. The clutch mechanism 6 includes a locking pin 61 pressing against the internal gear ring 913 and an elastic element 72 providing locking force to the locking pin 61. The front end face of the internal gear ring 913 has a forward-extending limiting protrusion 914. The rear end of the locking pin 61 abuts against the limiting protrusion 914 via a steel ball 62 to restrict the rotation of the internal gear ring 913. In this embodiment, the elastic element 72 is a plurality of small springs evenly distributed circumferentially around the small-diameter portion 13 of the housing 1. Of course, in other embodiments, the elastic element 72 can also be a large spring arranged around the small-diameter portion 13. When the load on the output shaft 2 reaches the preset clutch torque, the limiting protrusion 914 on the internal gear ring 913 can push the locking pin 61 forward, and the internal gear ring 913 can rotate circumferentially. The power tool 100 is engaged, and the torque of the motor 5 cannot be transmitted to the output shaft 2.

[0054] Referring to Figures 3, 4, and 5, the torque adjustment mechanism 7 is used to adjust the biasing force applied by the elastic element 72 to the locking pin 61 by changing the degree of compression of the elastic element 72, thereby adjusting the clutch torque of the power tool 100. The torque adjustment mechanism 7 includes an adjusting nut 71 sleeved on the small diameter portion 13 and an elastic element 72 pressing against the locking pin 61 and the adjusting nut 71. The adjusting nut 71 can move back and forth along the axis 101 under the drive of the adjusting sleeve 4. In this embodiment, the adjusting nut 71 is connected to the adjusting sleeve 4 by engaging with the external thread 712 on the outer ring and the internal thread 43 on the inner wall of the adjusting sleeve 4. The inner ring of the adjusting nut 71 has a limiting notch 713 that matches the outer contour of the small diameter portion 13. When the user rotates the adjusting sleeve 4, the adjusting nut 71 can move back and forth under the driving force of the engagement of the external thread 712 and the internal thread 43 and the guiding action of the limiting notch 713, thereby changing the degree of compression of the elastic element 72. Different degrees of compression of the elastic element 72 correspond to different locking forces of the locking pin 61 on the internal gear ring 913. This locking force corresponds to the clutch torque of the power tool 100. The greater the locking force, the less likely the power tool 100 is to engage, thereby adjusting the clutch torque of the clutch mechanism 6. Of course, the connection between the adjusting sleeve 4 and the adjusting nut 71 is not limited to this. In other embodiments, the adjusting nut 71 can also engage with the adjusting sleeve 4 by thread to move back and forth under the drive of the adjusting sleeve 4.

[0055] Referring to Figures 3 and 4, the impact mechanism 3 is used to switch the power tool 100 between drilling mode and impact mode, thereby enabling the power tool 100's output shaft 2 to operate in two ways: either rotating only or rotating while moving axially. In this embodiment, the impact mechanism 3 includes a movable ratchet 32 ​​and a stationary ratchet 33 arranged opposite to each other. The stationary ratchet 33 is fixedly disposed inside the housing 1, and the movable ratchet 32 ​​is located in front of the stationary ratchet 33 and fixedly sleeved on the output shaft 2. The stationary ratchet 33 and the movable ratchet 32 ​​are arranged opposite to each other inside the housing 1, and their opposing end faces are both toothed surfaces. When the movable ratchet 32 ​​rotates with the output shaft 2 and moves closer to the stationary ratchet 33, the movable ratchet 32 ​​and the stationary ratchet 33 will continuously contact or move away from each other, generating a reciprocating force along the axial direction of the output shaft 2, which pushes the output shaft 2 to reciprocate back and forth along the rotation axis 101, thereby realizing the impact function. When the impact function is not required, simply separate the moving ratchet 32 ​​from the stationary ratchet 33 and restrict the axial movement of the output shaft 2 so that it cannot drive the moving ratchet 32 ​​to move axially. This invention restricts the axial movement of the output shaft 2 through a mode switching component 31, as shown in Figures 3 and 4. The mode switching component 31 is arranged around the output shaft 2 and is limited by a bearing 35 engaging with the stepped surface of the output shaft 2. The outer ring of the bearing 35 is fixedly connected to the mode switching component 31, and the inner ring is interference-fitted with the output shaft 2, axially limiting the stepped surface on the first half of the output shaft 2. Of course, in other embodiments, the mode switching component 31 can also directly limit the axial movement of the output shaft 2. The mode switching component 31 can move axially between a first position and a second position. When the mode switch 31 drives the bearing 35 to move backward to the second position shown in Figure 4, the output shaft 2 can move axially a short distance, and the power tool 100 is in impact mode. When the mode switch 31 drives the bearing 35 to move forward to the first position shown in Figure 3, the axial movement of the output shaft 2 is restricted by the bearing 25, and the power tool 100 is in drill mode. The impact mechanism 3 also includes a torsion spring 34 that drives the mode switch 31 to return from the second position to the first position to achieve reset. The rear end of the torsion spring 34 can be directly fixed to the housing 1, or it can be fixed to the stationary ratchet 33 as in this embodiment, while the front end of the torsion spring 34 is fixed to the inner wall of the mode switch 31. The torsion spring 34 is initially in a state of axial and circumferential compression. When the mode switch 31 moves from the first position to the second position, the torsion spring 34 is further compressed in the axial and circumferential directions. When the mode switch 31 is in a free state with its movement unrestricted, the torsion spring 34 releases the compressive force and applies a biasing force to the mode switch 31 in both the axial and circumferential directions, causing the mode switch 31 to reset from the second position to the first position.

[0056] Referring to Figures 3, 4, and 5, the power tool also includes an adjusting sleeve 4, whose rotating support is located at the small-diameter portion 13 of the housing 1. The adjusting sleeve 4 surrounds the adjusting nut 71 and the mode switching element 31. The power tool 100's switching between screw, drill, and impact modes is achieved by rotating the adjusting sleeve 4. Rotating the adjusting sleeve 4 causes the threaded adjusting nut 71 to move axially back and forth, thereby adjusting the power tool 100 to the screw mode until the clutch mechanism 6 disengages, at which point the power tool 100 is in drill mode. Continuing to rotate the adjusting sleeve 4, causing the mode switching element 31 to rotate and move from the first position to the second position, puts the power tool 100 in impact mode.

[0057] The adjustment sleeve 4 and the mode switching component 31 are connected by a pair of lever arms that can transmit force. As shown in Figure 6, in this embodiment, the inner wall of the adjustment sleeve 4 has a first lever arm 41 extending radially inward, and the outer wall of the mode switching component 31 has a transmission arm 311 extending radially outward. When the mode switching component 31 is in the first position, the first lever arm 41 and the transmission arm 311 overlap axially. When the adjustment sleeve 4 is rotated to switch the power tool 100 from the drill setting to the impact setting, the side of the first lever arm 41 will abut against the side of the transmission arm 311, thereby enabling the first lever arm 41 to drive the transmission arm 311 to rotate. The transmission arm 311 then drives the mode switching component 31 to rotate and move axially backward along the guide rail provided on the housing 1, moving from the first position to the second position.

[0058] As shown in Figures 9 and 10, the guide rail on the housing 1 is formed by a cover plate 8 fixed to the front end of the housing 1. The cover plate 8 can be fixedly connected to the front end face of the small diameter portion 13 of the housing 1 by screws. The side wall of the small diameter portion 13 has a plurality of circumferentially extending receiving grooves 11. The receiving grooves 11 can be divided into a first depth portion 111 and a second depth portion 112, the depth of the first depth portion 111 being less than the depth of the second depth portion 112. The rear end face of the cover plate 8 has a plurality of guide portions 81 extending into the receiving grooves 11 and extending axially rearward. The guide portions 81 have a first height portion 811 corresponding to the first depth portion 111 in axial position, a second height portion 812 corresponding to the second depth portion 112 in axial position, and a sliding portion 813 for connecting the first height portion 811 and the second height portion 812. The height of the second height portion 812 protruding from the rear end face of the cover plate 8 is greater than the height of the first height portion 811. The receiving groove 11 on the housing 1 and the guide portion 81 on the cover plate 8 together form a guide rail that moves the mode switching member 31 between a first position and a second position under the drive of the adjusting sleeve 4. The outer wall of the mode switching member 31 has a guide arm 312 that extends radially outward and is inserted into the receiving groove 11. When the guide arm 312 is located in the spatial position formed by the cooperation of the first depth portion 111 and the first height portion 811, the mode switching member 31 is located in the first position; when the guide arm 312 is located in the spatial position formed by the cooperation of the second depth portion 112 and the second height portion 812, the mode switching member 31 is located in the second position. In this embodiment, the outer wall of the mode switching member 31 has two relatively short guide arms 312 and one relatively long transmission arm 311, wherein the transmission arm 311, in conjunction with the guide portion 81 on the cover plate 8, also plays a guiding role.

[0059] When the mode switch 31 is biased by the torsion spring 34, the torsion spring 34 is always in a compressed state in the axial and circumferential directions. During the process of the adjusting sleeve 4 moving the mode switch 31 from the first position to the second position, the guide arm 312 moves from the first height portion 811 to the second height portion 812, closely adhering to the guide portion 81. In the second position, the torsion spring 34 is further compressed in the axial and circumferential directions. When the user rotates the adjusting sleeve 4 in the opposite direction, the first force arm 41 moves away from the transmission arm 311. At this time, the torsion spring 34 releases its axial and circumferential compressive force, driving the mode switch 31 to move from the second position back to the first position. The power tool 100 also switches from the impact mode to the drill mode. However, in practice, if the axial biasing force of the torsion spring 34 is too large, or the friction coefficient between the guide part 81 and the transmission arm 311 increases, or the mode switching component 31 gets stuck against the inner wall of the housing 1, the biasing force applied by the torsion spring 34 to the mode switching component 31 in the circumferential direction will be less than the resistance experienced by the mode switching component 31. This will prevent the torsion spring 34 from driving the mode switching component 31 to reset and move from the second position to the first position, and the power tool 100 will be unable to switch from the impact gear to the drill gear. To address this, in this embodiment, a second lever arm 42 extending radially inward is provided on the inner wall of the adjusting sleeve 4. When the adjusting sleeve 4 is rotated in the reverse direction, the side of the second lever arm 42 can abut against the side of the transmission arm 311, thereby driving the transmission arm 311 to rotate in the reverse direction. With this structure, even if the above-mentioned problem occurs, the mode switching component 31 can still reset and move from the second position to the first position.

[0060] Referring to Figure 6, the second lever arm 42 is formed on the inner wall of the adjusting sleeve 4 and is located behind the first lever arm 41. When the user rotates the adjusting sleeve 4 forward, the first lever arm 41 can abut against the transmission arm 311, while the second lever arm 42 is axially offset from the transmission arm 311, located axially behind the transmission arm 311, and cannot contact the transmission arm 311. When the first lever arm 41 drives the transmission arm 311 to rotate, the mode switching member 31 rotates and moves axially backward from the first position to the second position. At this time, because the transmission arm 311 moves axially backward, it overlaps with the second lever arm 42 axially. When the user rotates the adjusting sleeve 4 in the opposite direction, the second lever arm 42 can abut against the transmission arm 311 and drive the transmission arm to rotate in the opposite direction. In this embodiment, the second lever arm 42 can only drive the transmission arm 311 to move a small distance, and then the torsion spring 34 drives the mode switching member 31 to reset along the guide portion 81 on the cover plate 8 from the second position back to the first position. Of course, in other embodiments, due to the excessive resistance in the circumferential direction of the mode switching component 31, the second lever arm 42 needs to drive the transmission arm 311 to rotate until the second lever arm 42 and the transmission arm 311 are misaligned and separated in the axial direction.

[0061] As shown in Figures 7a-7c and 8a-8c, the positional relationship between the adjusting sleeve 4 and the mode switching component 31 in each mode is illustrated. In Figures 7a and 8a, the power tool 100 is in the screw position. The first arm 41 and the second arm 42 of the adjusting sleeve 4 are located circumferentially downstream of the transmission arm 311. When the adjusting sleeve 4 is rotated clockwise, the first arm 41 and the second arm 42 do not contact the transmission arm 311, and the mode switching component 31 is in the aforementioned first position. In Figures 7b and 8b, the power tool 100 is in the drill position. Because the second arm 42 of the adjusting sleeve 4 is axially misaligned with the transmission arm 311, the second arm 42 has passed over the transmission arm 311 from behind, and they do not contact each other. Meanwhile, the first arm 41 moves circumferentially upstream of the transmission arm 311. If the adjusting sleeve 4 is rotated clockwise further, the first arm 41 will drive the transmission arm 311 to rotate. As shown in Figures 7c and 8c, when the power tool 100 is in impact mode, the first lever arm 41 of the adjusting sleeve 4 drives the transmission arm 311 to rotate clockwise. The mode switching component 31 rotates while moving axially backward to the second position. At this point, the second lever arm 42 overlaps with the transmission arm 311 axially. When the user rotates the adjusting sleeve 4 counterclockwise, the second lever arm 42 drives the transmission arm 311 to rotate counterclockwise, resetting the mode switching component 31 to the first position. Furthermore, as shown in Figures 7a-7c and 8a-8c, the first lever arm 41 and the second lever arm 42 also have a certain circumferential distance, which is at least greater than the width of the transmission arm 311. This arrangement ensures that after the first lever arm 41 rotates clockwise, driving the transmission arm 311 to move the mode switching component 31 from the first position to the second position, the second lever arm 42 can be located circumferentially downstream of the transmission arm 311. Thus, when the adjusting sleeve 4 is rotated counterclockwise, the second lever arm 42 can drive the transmission arm 311 to rotate counterclockwise.

[0062] Referring to Figures 2 and 3, when the power tool 100 is in screw mode, considering the overall length, to minimize the length of the power tool 100, the adjusting nut 71 needs to be axially very close to, or even directly against, the first lever arm 41 in the 0 position. However, in this embodiment, a second lever arm 42 is also provided on the inner wall of the adjusting sleeve 4, located behind the first lever arm 41, to drive the mode switching component 31 back to the first position. Therefore, to avoid interference between the adjusting nut 71 and the second lever arm 42, the overall length of the power tool 100 needs to be increased to provide a certain axial distance between the front limit position of the adjusting nut (the position in the 0 position) and the first lever arm 41 to accommodate the second lever arm 42.

[0063] In this embodiment, considering that the adjusting nut 71 will axially retract as the adjusting sleeve 4 rotates, and that the adjusting sleeve 4 only needs to rotate a small angle for the adjusting nut 71 to make room for the second lever arm 42, an arc-shaped relief groove 711 can be recessed into the rearward front face of the adjusting nut 71. During the rotation of the second lever arm 42 with the adjusting sleeve 4 and the axial movement of the adjusting nut 71 with the adjusting sleeve 4, the relief groove 711 has sufficient space to accommodate the second lever arm 42, ensuring that the second lever arm 42 and the adjusting nut 71 will not interfere with each other in the axial and circumferential directions, regardless of whether the adjusting sleeve 4 is rotated in the forward or reverse direction.

[0064] Referring to Figures 11a and 11b, to minimize disruption to the structural strength of the adjusting nut 71 while ensuring that the second lever arm 42 and the adjusting nut 71 do not interfere with each other, the position and arc length of the clearance groove 711 need to be determined. As shown in Figure 11a, when the power tool 100 is in its lowest screw position, the adjusting nut 71 is closest to the second lever arm 42, and their axial overlap is at its maximum, with one end of the clearance groove 711 close to the second lever arm 42. As shown in Figure 11b, when the power tool 100 is in its screw position and the adjusting sleeve 4 is rotated a certain angle in the positive direction, the adjusting nut 71 has moved axially backward a certain distance. The adjusting nut 71 and the second lever arm 42 are now axially offset, and the second lever arm 42 is completely disengaged from the clearance groove 711.

[0065] Combining the two extreme states between the second lever arm 42 and the clearance groove 711, as shown in Figure 12, the depth of the clearance groove 711 can be denoted as h, and the axial distance between the lower end face of the first lever arm 41 and the lower end face of the second lever arm 42 can be denoted as d. Then, h must be greater than or equal to d to ensure that the clearance groove 711 can accommodate the second lever arm 42 when the power tool 100 is in the state shown in Figure 11a. As shown in Figure 13, rotating the adjusting sleeve 4 causes the second lever arm 42 to rotate within the clearance groove 711 and form an arc trajectory. The included angle corresponding to this arc trajectory is α, and the external thread pitch of the adjusting nut 71 is denoted as C. Then, α must satisfy ≥ (d / C) × 360° so that the arc length of the clearance groove 711 can accommodate the second lever arm 42 throughout the entire movement of the adjusting sleeve 4. Furthermore, the included angle α must also satisfy α ≤ 90°. The included angle α should not be too large, otherwise it will occupy the circumferential adjustment space of the screw stop, thus shortening the torque adjustment range of the power tool 100.

[0066] Referring to Figure 6, the front end face of the adjusting nut 71 has a rearwardly recessed relief groove 711, and the rear end face of the adjusting nut 71 has multiple connecting posts 714 for mounting the elastic element 72. The area on the adjusting nut 71 where the elastic element 72 is mounted is a stress concentration area. Therefore, in order to avoid the relief groove 711 from affecting the structural strength of the adjusting nut 71, the relief groove 711 should be at least partially or even entirely set between two adjacent connecting posts 714 to prevent the adjusting nut 71 from becoming thinner in the area where the connecting posts 714 are formed.

[0067] In the power tool 100 of the present invention, when the user rotates the adjusting sleeve 4 forward to switch modes from drill mode to impact mode, the adjusting sleeve 4, through the first lever arm 41, drives the mode switching component 31 to rotate and move axially backward from the initial first position to a second position axially rearward, thereby providing space for the output shaft 2 to move axially. When the power tool 100 is in impact mode and the user rotates the adjusting sleeve 4 in reverse to switch modes from impact mode back to drill mode, the adjusting sleeve 4, through the second lever arm 42, drives the mode switching component 31 to rotate in the opposite direction, enabling it to overcome resistance and reset from the second position to the first position. During the aforementioned forward rotation of the adjusting sleeve 4, since the second lever arm 42 and the mode switching component 31 are misaligned axially, they cannot contact each other, and the forward rotation of the adjusting sleeve 4 is not affected; during the reverse rotation of the adjusting sleeve 4, since the mode switching component 31 has moved axially backward to a second position where it can overlap with the second lever arm 42 axially, the second lever arm 42 can drive the mode switching component 31 to rotate in the opposite direction.

[0068] The power tool 100 of the present invention, based on the above-mentioned addition of a second lever arm 42 located behind the first lever arm 41 to the inner wall of the adjusting sleeve 4 to ensure that the mode switching component 31 can be reset, provides a rearwardly recessed clearance groove 711 on the front end face of the adjusting nut 71 adjacent to the rear of the second lever arm 42 in order to neither affect the function of other components nor increase the overall length of the power tool 100. This clearance groove 711 can accommodate the second lever arm 42 during the rotation of the adjusting sleeve 4 and the simultaneous axial movement of the adjusting nut 71, until the adjusting nut 71 moves axially away from the second lever arm 42, so that the second lever arm 42 and the adjusting nut 71 will not interfere with each other in the axial and circumferential directions.

[0069] This application is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative solutions exist for the dual-speed ratchet wrench without departing from the principles and scope of this application. The scope of protection of this application is determined by the claims.

Claims

Power tools (100), including: Casing (1); The output shaft (2) is rotatably supported within the housing (1); The impact mechanism (3) includes a mode switching component (31), a movable ratchet (32) fixed to the output shaft (2), and a stationary ratchet (33) fixed to the housing (1) and disposed opposite to the movable ratchet (32). The mode switching component (31) can move in a first position and a second position along the axial direction of the output shaft (2). When the mode switching component (31) moves to the first position, it prevents the stationary ratchet (33) from engaging with the movable ratchet (32). When the mode switching component (31) moves to the second position, it allows the stationary ratchet (33) to engage with the movable ratchet (32). An adjusting sleeve (4) is rotatably supported on the housing (1) and located on the outer periphery of the mode switching member (31). The adjusting sleeve (4) has a first lever arm (41), and the mode switching member (31) has a transmission arm (311) that can abut against the first lever arm (41). When the adjusting sleeve (4) is rotated in a first direction, the first lever arm (41) drives the transmission arm (311) to rotate and moves the mode switching member (31) from a first position to a second position. Its features are: The adjusting sleeve (4) also has a second lever arm (42); When the mode switching component (31) is held in the first position, the transmission arm (311) and the second force arm (42) are misaligned in the axial direction. When the adjusting sleeve (4) rotates, the second force arm (42) cannot contact the transmission arm (311). When the mode switching component (31) is held in the second position, the transmission arm (311) moves to overlap with the second force arm (42) axially and rotates the adjustment sleeve (4) in a direction opposite to the first direction. The second force arm (42) drives the mode switching component (31) to rotate. The power tool according to claim 1, characterized in that: The first lever arm (41) and the second lever arm (42) are protrusions extending from the inner wall of the adjusting sleeve (4) toward the mode switching member (31); The transmission arm (311) is a protrusion extending from the outer wall of the mode switching component (31) to the adjustment sleeve (4). The first lever arm (41) and the second lever arm (42) abut against the side wall of the transmission arm (311) to drive the transmission arm (311) to rotate. The power tool according to claim 1, characterized in that: The axial distance between the first lever arm (41) and the front end of the adjusting sleeve (4) is less than the axial distance between the second lever arm (42) and the front end of the adjusting sleeve (4). The power tool according to claim 1, characterized in that: The circumferential distance between the first lever arm (41) and the second lever arm (42) is greater than or equal to the width of the transmission arm (311). The power tool according to claim 1, characterized in that: The housing (1) has a circumferentially extending receiving groove (11) formed on its side wall. The receiving groove (11) has a first depth portion (111) and a second depth portion (112), and the depth of the second depth portion (112) is greater than the depth of the first depth portion (111). The mode switching component (31) has a guide arm (312) extending toward the receiving groove (11), and the guide arm (312) is held in the receiving groove (11); When the guide arm (312) is held at the first depth portion (111), the mode switching member (31) is held at the first position; When the guide arm (312) is held at the second depth (112), the mode switch (31) is held at the second position. The power tool according to claim 5, characterized in that: The front end of the housing (1) is connected to a cover plate (8). The cover plate (8) is provided with a guide portion (81) extending toward the guide arm (312). The guide portion (81) is disposed opposite to the receiving groove (11). The guide portion (81) has a first height portion (811) and a second height portion (812) and a sliding portion (813) located between the first height portion (811) and the second height portion (812). The second height portion (812) protrudes from the cover plate (8) at a height greater than the height of the first height portion (811). The guide arm (312) is driven by the adjusting sleeve (4) to move along the extension direction of the guide portion (81); When the guide arm (312) moves to the first height portion (811), the mode switching member (31) remains in the first position; When the guide arm (312) moves to the second height portion (812), the mode switching member (31) remains in the second position. The power tool according to claim 6, characterized in that: The power tool (100) includes a torsion spring (34), one end of which directly or indirectly abuts against the housing (1), and the other end abuts against the mode switch (31) to drive the mode switch (31) to reset from the second position to the first position. When the mode switching component (31) moves from the first position to the second position, the torsion spring (34) is further compressed in the axial and circumferential directions; When the mode switching component (31) moves from the second position to the first position, the torsion spring (34) releases the compressive force and pushes the guide arm (312) to slide along the sliding part (813). The power tool according to claim 7, characterized in that: One end of the torsion spring (34) abuts against the stationary ratchet (33), and the other end abuts against the inner wall of the mode switching component (31). The power tool according to claim 1, characterized in that: The housing (1) has a large diameter portion (12) and a small diameter portion (13), the large diameter portion (12) being used to house the gear set and the small diameter portion (13) being used to house the impact mechanism (3). The power tool according to claim 9, characterized in that: The adjusting sleeve (4) is rotatably supported on the small diameter portion (13).

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