Power tool

Abstract

The application provides an electric tool, and relates to a mode switching system thereof. The electric tool comprises a mode switching part which can be switched to a first position close to the static ratchet wheel or a second position away from the static ratchet wheel along the front-back direction; when the mode switching part is located at the second position, the output shaft is compressed towards the back, the static ratchet wheel cannot be engaged with the dynamic ratchet wheel, the electric tool further comprises a limiting part clamped to the back side of the output shaft, the elastic part presses the limiting part on the transmission assembly through the output shaft, and an impact length X between the step part and the mode switching part is formed. The electric tool provided by the application can perform torque adjustment and mode switching only by using one adjusting sleeve, and one annular support is omitted in the axial structure, so that the overall length of the electric tool is reduced.

Description

Technical Field

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

[0002] Electric drills with impact functions typically have several operating modes, such as screw drive, drill drive, and impact drive. When using screw drive mode, the control setting must be adjusted to screw drive. In this mode, the impact drill will determine when to switch gears based on the screw drive torque setting. When switching gears, the impact drill's rotary motor continues to rotate, but the screwdriver remains stationary, and the impact drill cannot output maximum torque. When using drill drive mode, the rotary motor and the drill bit maintain the same motion, outputting maximum torque and preventing gear switching. When using impact drive mode, in addition to retaining the original drill drive functions, the impact mechanism will be activated simultaneously to provide impact force, allowing for more efficient drilling operations on concrete walls or other hard objects.

[0003] However, existing electric drill impact structures involve arranging a bracket-like component on the shaft. The working mode of the electric drill is switched by whether or not the axial limit of this bracket-like component is engaged. For example, the Chinese utility model patent with authorization announcement number CN211053606U uses the cooperation of a ring bracket and a mode switching sleeve to switch working modes, and uses a torque adjustment sleeve to adjust the torque of the screw stop. This type of electric drill, which uses two adjustment sleeves and a ring bracket for torque adjustment and mode switching, adds multiple components in the axial direction, resulting in an excessively long overall length of the electric drill. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a power tool that can adjust torque and switch modes using only one adjusting sleeve, and eliminates a ring bracket in the axial structure, thereby reducing the overall length of the power tool.

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

[0006] shell;

[0007] The output shaft has a stepped portion on its front side that restricts the rearward movement of the output shaft;

[0008] A transmission assembly, housed in the housing, drives the output shaft;

[0009] An impact assembly includes a stationary ratchet and a movable ratchet. The stationary ratchet is fixedly connected to the housing, and the movable ratchet is fixedly connected to the output shaft and is disposed opposite to the stationary ratchet 45.

[0010] A mode switching component is located between the moving ratchet and the stepped portion and rotatably supports the output shaft. The mode switching component can be switched in the front-back direction to a first position close to the stationary ratchet or a second position far away from the stationary ratchet.

[0011] An elastic element, one end of which presses against the mode switching element, and the other end of which presses against the output shaft;

[0012] When the mode switching component is in the first position, the elastic element presses the moving ratchet against the mode switching component through the output shaft to disengage the moving ratchet from the stationary ratchet and form an impact length L between the stepped portion and the mode switching component, compressing the output shaft backward, and the stationary ratchet meshes with the moving ratchet.

[0013] When the mode switching component is in the second position, it compresses the output shaft backward, and the stationary ratchet and the moving ratchet cannot mesh. The power tool also includes a limiting component that is held at the rear side of the output shaft. The elastic component presses the limiting component against the transmission assembly through the output shaft, forming an impact length X between the stepped portion and the mode switching component. The impact length X is less than the impact length L.

[0014] A further improvement is that the mode switching component supports the output shaft via a rotating bearing;

[0015] The bearing is located between the moving ratchet and the stepped portion, and its outer ring is fixedly connected to the mode switching component, while its inner ring is clearance-fitted with the output shaft.

[0016] A further improvement is that the elastic element is a conical spring, with its front end pressing against the output shaft and its rear end pressing against the inner ring of the bearing.

[0017] A further improvement is as follows: when the mode switching component is in the second position, with the impact length X being 0, the stepped portion abuts against the front end of the bearing.

[0018] A further improvement is that the transmission assembly includes a motor and a planetary gear set, and the motor drives the output shaft through the planetary gear set;

[0019] The limiting component is a snap ring or an O-ring, which presses against the planetary gear set.

[0020] A further improvement is as follows: the power tool further includes an adjusting sleeve, which is rotatably supported on the housing and drives the mode switching component to move in the front-to-back direction via a transmission guide device. The transmission guide device includes:

[0021] A guide plate, which is fixedly connected to the housing, has guide protrusions extending toward the mode switching component;

[0022] A guide groove is formed in the outer shell, and the guide groove and the end face of the guide protrusion together form a guide path;

[0023] A first arm is formed in the mode switcher and passes through the guide groove. The first arm is driven by the mode switcher to move along the guide path.

[0024] The mode switching component has a second arm extending toward the adjustment sleeve;

[0025] A transmission flange is provided on the adjusting sleeve, which extends toward the mode switching component.

[0026] The transmission flange engages with the second arm to transmit the external force received by the adjustment sleeve to the mode switching member, causing the mode switching member to move along the guide path.

[0027] A further improvement is that a guide slope is formed between the inner end face of the guide plate and the inner end face of the guide protrusion to form a guide path between the two.

[0028] When the first arm abuts against the inner end face of the guide plate, the mode switching component is in the second position;

[0029] When the first arm abuts against the inner end face of the guide protrusion, the mode switching component is in the first position.

[0030] A further improvement is that the inner end face of the guide protrusion is formed with a guide rib to abut against the first arm.

[0031] A further improvement is that the mode switching component is also connected to a reset component, which is used to drive the mode switching component to move from the first position to the second position along the guide path when the transmission flange is separated from the second arm.

[0032] A further improvement is as follows: the reset component is a torsion spring, with connecting feet formed at both ends. One connecting foot is fixedly connected to the stationary ratchet, and the other is fixedly connected to the inner wall of the mode switching component.

[0033] Compared with the prior art, this application has the following beneficial effects:

[0034] I. This application provides an electric tool in which the adjusting sleeve is constructed with a two-stage stroke. In the first stage of the stroke, the torque is adjusted, and in the second stage of the stroke, the mode switching component is moved to switch the working mode. The mode switching component is sleeved on the outer circumference of the output shaft. This type of electric tool eliminates the length of the mode switching key in the axial structure and uses only one adjusting sleeve to adjust the torque and switch the working mode, which can greatly shorten the overall length of the machine.

[0035] 2. This application provides an electric tool in which, after the output shaft is axially limited by an axially movable mode switch, the output shaft will extend forward in screw mode and drill mode, resulting in "play" and increasing the length of the whole machine. Therefore, this application uses a limiting device to limit the output shaft to prevent it from extending forward and avoid the generation of "play".

[0036] Third, this application provides an electric tool in which a mode switching component sleeved around the output shaft axially limits the output shaft. Therefore, in impact mode, the output shaft only slides and rubs against the mode switching component and does not rub against the housing. The electric tool will not wear the housing in impact mode. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the electric drill in a preferred embodiment of this application;

[0038] Figure 2 for Figure 1 A schematic diagram of the internal structure of the electric drill shown.

[0039] Figure 3 for Figure 1 The diagram shows the structural schematic of the electric drill gearbox housing.

[0040] Figure 4 for Figure 3 A half-sectional view of the internal structure of the gearbox housing shown;

[0041] Figure 5 for Figure 1 The diagram shows the structural fit between the electric drill adjusting sleeve and the adjusting nut.

[0042] Figure 6 for Figure 1 The diagram shows the structure of the electric drill clutch mechanism;

[0043] Figure 7 for Figure 1 The diagram shows the structural fit between the adjusting nut and the gear-adjusting washer of the electric drill.

[0044] Figure 8 for Figure 1 The diagram shows the structure of the electric drill adjusting nut and the gear adjusting washer when the electric drill is in drill mode.

[0045] Figure 9 for Figure 1 The diagram shows the structure of the electric drill adjusting nut and gear adjusting washer when the electric drill is in impact gear mode.

[0046] Figure 10 for Figure 1 The diagram shows the internal structure of the electric drill gearbox housing.

[0047] Figure 11 for Figure 1 The diagram shows the structure of the drill mode switcher when it is in the first position.

[0048] Figure 12 for Figure 1 The diagram shows the structure of the drill mode switch when it is in the second position.

[0049] Figure 13 for Figure 1 The diagram shows the structural fit between the drill guide plate and the mode switching component.

[0050] Figure 14 for Figure 1 The diagram shows the structure of the electric drill guide plate.

[0051] Figure 15 for Figure 1 The diagram shows the structural cooperation between the drill mode switching component and the compression spring.

[0052] Figure 16 for Figure 1 The diagram shows the structure of the electric drill adjusting sleeve.

[0053] Figure 17 for Figure 1 The top view of the drill adjustment sleeve and mode switching component in the transmission connection state shown.

[0054] Figure 18 for Figure 1 The diagram shows the internal structure of the gearbox housing when the electric drill is in screw or drill mode without a stopper.

[0055] Figure 19 for Figure 1 The diagram shows the internal structure of the gearbox housing when the electric drill is in impact mode without a limiter;

[0056] Figure 20 for Figure 1 The diagram shows the internal structure of the gearbox housing when the electric drill is in screw stop or drill stop mode with the limit device configured.

[0057] Figure 21 for Figure 1 The diagram shows the internal structure of the gearbox housing when the electric drill is in impact mode with the limit device installed.

[0058] Figure 22 for Figure 1 The exploded view of the assembly of the electric drill gearbox housing is shown.

[0059] Meaning of the reference numerals in the diagram:

[0060] 1. Electric drill

[0061] 10. Outer shell; 11. Main body outer shell; 12. Gearbox outer shell; 121. Mounting part; 122. Stop rib; 123. Guide groove; 13. Handle part.

[0062] 20. Transmission assembly; 21. Motor; 22. Planetary gear set; 23. Clutch mechanism; 231. Internal meshing gear; 232. Steel ball; 233. Pin.

[0063] 30. Torque assembly; 31. Adjusting sleeve; 311. First thread; 312. Slot; 313. Drive flange; 32. Adjusting nut; 321. Second thread; 322. Second mating surface; 323. Mounting post; 33. Compression spring; 34. Skip-off washer; 341. Locking block; 342. First mating surface; 343. Abutment ring surface; 35. Anti-rotation washer.

[0064] 40. Impact assembly; 41. Guide plate; 411. Guide protrusion; 412. Guide ramp; 413. Guide rib; 42. Mode switching component; 421. First arm; 422. Second arm; 423. Fitting ramp; 43. Reset component; 431. Connecting foot; 44. Moving ratchet; 45. Stationary ratchet; 46. Bearing.

[0065] 50. Output component, 51. Output shaft, 511. Stepped part, 52. Elastic element, 53. Limiting element. Detailed Implementation

[0066] 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.

[0067] The specific embodiments of this application will be described below with reference to the accompanying drawings.

[0068] Reference Figure 1 For ease of explanation, the power tool provided in this application is an example of an electric drill 1, which can switch between screw mode, drill mode and impact mode to meet different user needs.

[0069] Reference Figure 2The electric drill 1 includes a housing 10 and a transmission assembly 20, a torque assembly 30, an impact assembly 40, and an output assembly 50 supported on the housing 10. The transmission assembly 20 transmits power to the output assembly 50, driving the output shaft 51 of the output assembly 50 to rotate around the axis 101 to output power. The torque assembly 30 and the impact assembly 40 are used to change the output torque and output form of the output shaft 51.

[0070] To facilitate a clear explanation of the technical solution, the following definitions are made: the direction of the axis 101 on which the output shaft 51 rotates and the direction parallel to the axis 101 are defined as the axial direction; the radial direction of the circumference with the axis 101 as the central axis is defined as the radial direction; the power output direction along the output shaft 51 is defined as the forward direction; and the direction opposite to the power output of the output shaft 51 is defined as the rearward direction.

[0071] Reference Figure 2 The outer casing 10 includes a main casing 11 and a gearbox casing 12, which can be integrally formed or connected and fixed by fasteners. The main casing 11 and the gearbox casing 12 can provide support and housing space for the transmission assembly 20. The main casing 11 can also be formed with a handle 13 for the user to hold.

[0072] The transmission assembly 20 includes a motor 21 supported on the main housing 11, a planetary gear set 22 supported on the gearbox housing 12, and a clutch mechanism 23. The power source provided by the motor 21 is transmitted to the output shaft 51 via the planetary gear set 22, which can be composed of a single-stage or multi-stage gear set. The clutch mechanism 23 is used to interrupt the torque output from the motor 21 to the output shaft 51 when the torque applied to the output shaft 51 exceeds a set threshold.

[0073] Reference Figure 3 A mounting portion 121 for supporting the impact assembly 30 is formed at the front end of the gearbox housing 12. To ensure a smooth and harmonious overall appearance of the housing 10, the diameter of the mounting portion 121 can be set smaller than that of other parts of the gearbox housing 12, so as to provide sufficient installation space for supporting the torque assembly 30 and the impact assembly 40. Of course, the installation positions of the torque assembly 30 and the impact assembly 40 are not limited to this, and the torque assembly 30 and the impact assembly 40 can be set in appropriate positions according to the actual structure of the electric drill 1.

[0074] Reference Figure 4 , Figure 5 , Figure 6The torque assembly 30 is used to adjust the output torque when the electric drill 1 is in the screw position. It includes an adjusting sleeve 31 rotatably supported on the mounting portion 121, an adjusting nut 32 movable axially along the mounting portion 121, and a biasing member connected to the adjusting nut 32. The inner wall of the adjusting sleeve 31 has a first thread 311, and the outer peripheral surface of the adjusting nut 32 has a second thread 321 that engages with the first thread 311. The outer peripheral surface of the mounting portion 121 has a stop rib 122 for restricting the circumferential rotation of the adjusting nut 32. The inner wall contour of the adjusting nut 32 is adapted to the outer peripheral contour of the mounting portion 121. When the adjusting sleeve 31 rotates, the adjusting nut 32 can move axially along the mounting portion 121, thereby compressing the biasing member to varying degrees. This, combined with the clutch mechanism 23, adjusts the output torque of the electric drill 1 when it is in the screw position. Wherein, as Figure 4 As shown, the biasing component can be specifically implemented as a compression spring 33. The clutch mechanism 23 includes an internal meshing gear 231 that is connected to the planetary gear set 22, a steel ball 232 and a pin 233 that are engaged with the front end face of the internal meshing gear 231, and a compression spring 33 that applies a biasing force to the pin 233. The front end face of the internal meshing gear 231 has a protrusion. Under normal conditions, the steel ball 232 is pressed against the front end face of the internal meshing gear 231 by the force of the compression spring 33, so that the protrusion on the front end face of the internal meshing gear 231 cannot pass over the steel ball 232. The internal meshing gear 231 is fixed relative to the outer casing 10, and the planetary gear set 22 that interacts with the internal meshing gear 231 drives the output shaft 51 to rotate. When the torque acting on the output shaft 51 exceeds the torque threshold provided by the compression spring 33, the torque of the planetary gear set 22 acting on the internal meshing gear 231 is sufficient to overcome the force of the compression spring 33 acting on the internal meshing gear 231. The protrusion on the front end face of the internal meshing gear 231 passes over the steel ball 232. At this time, the internal meshing gear 231 rotates relative to the outer casing 10, the output shaft 51 is in a clutch state, and its torque output is cut off, that is, a gear skipping occurs.

[0075] Reference Figure 6The torque assembly 30 also includes a shift washer 34 that can rotate circumferentially with the adjusting sleeve 31, and an anti-rotation washer 35 circumferentially fixed to the mounting portion 121. The front end face of the shift washer 34 has a first engagement surface 342 that engages with the adjusting nut 32 and an abutment ring surface 343 that engages with the anti-rotation washer 35. The shift washer 34 has a ring structure and can have three locking blocks 341 integrally formed on its outer circumferential surface. The inner wall of the adjusting sleeve 31 can extend axially to form a locking groove 312 that engages with the locking blocks 341. In this way, the shift washer 34 can be inserted into the adjusting sleeve 31 through the engagement of the locking blocks 341 and the locking groove 312, so that the shift washer 34 can rotate with the circumferential rotation of the adjusting sleeve 31. In addition, the locking blocks 341 can be made to protrude from the front end face of the shift washer 34 to increase the engagement area between the locking blocks 341 and the locking groove 312, thereby improving the engagement strength between the two. The adjusting nut 32 moves linearly back and forth, thereby compressing the compression spring 33 to varying degrees. The front end of the compression spring 33 is connected to the adjusting nut 32, and the rear end abuts against the shift washer 34. The biasing force of the compression spring 33 is transmitted to the pin 233 and the steel ball 232 through the shift washer 34. However, the adjusting nut 32 is circumferentially locked and cannot rotate, while the shift washer 34 rotates with the adjusting sleeve 31. Therefore, there is relative rotational movement between the rear end of the compression spring 33 and the shift washer 34. To achieve this assembly between the adjusting nut 32, the compression spring 33, and the shift washer 34, the compression spring 33 could be implemented as a large spring, which would be sleeved on the adjusting nut 32 and surround the outer periphery of the gearbox housing 12. However, if the compression spring 33 is implemented as a large spring, its elastic force variation range is small, resulting in a small torque adjustment range for the entire electric drill 1. Therefore, the compression spring 33 can also be implemented as a small spring, with several small springs circumferentially distributed around the outer periphery of the gearbox housing 12. Several mounting posts 323 are formed circumferentially at the rear end of the adjusting nut 32, extending rearward. Each small spring is fitted onto a mounting post 323. To prevent circumferential friction between the rear end of the small spring and the shift washer 34, which would affect the biasing force applied by the compression spring 33 to the clutch mechanism 23, an anti-rotation washer 35 can be provided between the compression spring 33 and the shift washer 34. The anti-rotation washer 35 has an annular structure, and its inner wall contour matches the outer periphery contour of the mounting portion 121. The circumferential rotation of the anti-rotation washer 35 is restricted by the stop rib 122 on the outer periphery of the mounting portion 121. The front end of the anti-rotation washer 35 abuts against the compression spring 33, and the rear end abuts against the shift washer 34. (Refer to...) Figure 7The portion of the front end face of the shift washer 34 that abuts against the anti-rotation washer 35 is an abutment annular surface 343. The abutment annular surface 343 and the first engagement surface 342 can be coaxial annular structures, and the abutment annular surface 343 is located within the ring formed by the first engagement surface 342. The first engagement surface 342 on the shift washer 34 is used to engage with the second engagement surface 322 on the adjusting nut 32. Both the first engagement surface 342 and the second engagement surface 322 have spaced outward protrusions and inward concave portions, and they have two engagement states: a first engagement state in which the outward protrusions of the two abut against each other, and a second engagement state in which the outward protrusion of one of the two and the inward concave portion of the other are fitted together. In some embodiments, the first engagement surface 342 and the second engagement surface 322 can be specifically implemented as follows: Figure 7 The annular waveform surface that matches the dimensions and contours shown can be joined in two ways: as follows Figure 8 The shown is the contact state where the wave crests meet, such as... Figure 9 The diagram shows the engagement state where one crest of a wave meets the trough of another. In this engagement state, the distance between the adjusting nut 32 and the shift washer 34 is smaller than the distance in the contact state. According to this structure, when the user rotates the adjusting sleeve 31, driving the adjusting nut 32 to gradually compress the compression spring 33 until the crest of the second mating surface 322 on the adjusting nut 32 contacts the crest of the first mating surface 342, the drill 1 switches from the screw setting to the drill setting. Because the distance between the shift washer 34 and the adjusting nut 32 in the engagement state is smaller than the distance in the contact state, the difference in distance between the two engagement states allows the adjusting nut 32 to continue moving backward. Therefore, the user can continue to rotate the adjusting sleeve 31, changing the two from the contact state to the engagement state, and the drill 1 can also switch from the drill setting to the impact setting.

[0076] When the drill 1 is switched to the impact mode, the impact assembly 40 can drive the output shaft 51 to perform an impact. (Refer to...) Figure 10 The impact assembly 40 includes a guide plate 41 fixed to the front end of the gearbox housing 12, a mode switching component 42 that can move rearward under the drive of the adjusting sleeve 31, a reset component 43 connected to the mode switching component 42, a moving ratchet 44 fixed to the output shaft 51, and a stationary ratchet 45 fixed inside the gearbox housing 12. The guide plate 41 can be fixed to the front end face of the gearbox housing 12 by screws or other fasteners, and its rear end face is provided with a rearwardly extending guide protrusion 411, as shown in the figure. Figure 13 , Figure 14 The rear end face of the guide plate 41 has three circumferentially distributed guide protrusions 411, and a guide ramp 412 is formed between the guide protrusions 411 and the rear end face of the guide plate 41. The mode switching component 42 moves along the guide ramp 412 from the rear end face of the guide plate 41 to the guide protrusions 411, completing the action of moving backward under the drive of the adjusting sleeve 31, thereby causing the mode switching component 42 to move from the rear end face of the guide plate 41 to the guide protrusions 411. Figure 11 The second position shown is moved to, as Figure 12 The first position is shown. In addition, in order to reduce the frictional resistance between the mode switching component 42 and the guide ramp 412 during relative movement, a guide rib 413 can be provided on the end face of the guide protrusion 411 along its length extension direction. The mode switching component 42 moves in contact with the guide rib 413, thereby reducing the frictional resistance between the mode switching component 42 and the guide ramp 412 by reducing the contact area between the two.

[0077] Reference Figure 10 , 11 , Figure 15 The mode switching component 42 can be a ring-shaped sleeve structure, with a bearing 46 fixed to its inner wall. The bearing 46 is clearance-fitted with the output shaft 51. In ring-shaped support-type mode switching structures, the bearing is fixedly sleeved on the output shaft. When the output shaft is impacted, the bearing will slide against the outer casing, causing wear on the outer casing 10. However, in some embodiments of this application, when the output shaft 51 is impacted, only the output shaft 51 slides relative to the inner ring of the bearing 46, and there is no relative sliding with the outer casing 10, thus avoiding wear on the outer casing 10.

[0078] Furthermore, the mode switching component 42 has a first arm 421 extending radially from its outer periphery, corresponding one-to-one in position and number to the aforementioned guide protrusions 411. The mode switching component 42 also has a second arm 422 extending radially from its outer periphery, and the inner wall of the aforementioned adjusting sleeve 31 has a corresponding transmission flange 313. Figure 16 (As shown). When the electric drill 1 switches from the drill mode to the impact mode, the user rotates the adjusting sleeve 31. At this time, the side wall of the transmission flange 313 overlaps with the side wall of the second arm 422. According to this structure, the adjusting sleeve 31 can drive the mode switching component 42 to rotate a certain angle. During the rotation of the mode switching component 42, the second arm 422 moves along the guide slope 412 from the rear end face of the guide plate 41 to the guide protrusion 411. In this way, the mode switching component 42 moves backward with the bearing 46. The mode switching component 42 moves from the second position to the first position, thereby providing the impact length for the output shaft 51.

[0079] Reference Figure 10 The mode switch 42 is also connected to a reset component 43, which can reset the mode switch 42 axially and radially. Since the adjusting sleeve 31 drives the mode switch 42 to rotate unidirectionally by connecting with the second arm 422 via the transmission flange 313, causing the mode switch 42 to rotate and move backward under the action of the guide plate 41, when the adjusting sleeve 31 rotates in the opposite direction, the mode switch 42 needs to be reset to its original position with the help of the reset component 43. The reset component 43 needs to reset the mode switch 42 both axially and circumferentially. Therefore, the reset component 43 can be specifically implemented as follows: Figure 17 The torsion spring shown. Figure 17In the middle, the reset member 43 has connecting feet 431 at both ends. One end can be fixedly connected to the gearbox housing 12 or the stationary ratchet 45, and the other end is fixedly connected to the mode switch member 42. When the adjusting sleeve 31 drives the mode switch member 42 to move along the guide track of the guide plate 41, the mode switch member 42 moves from the second position to the first position. It not only rotates circumferentially but also moves axially backward. Correspondingly, the reset member 43 is not only compressed circumferentially but also compressed axially. Therefore, when the adjusting sleeve 31 rotates in the opposite direction to make the transmission flange 313 move away from the second arm 422, the reset member 43 applies a biasing force to the mode switch member 42 not only circumferentially but also axially, so that the mode switch member 42 is reset from the first position to the second position.

[0080] The aforementioned mode switching component 42 is used to limit the output shaft 51 axially backward. When the mode switching component 42 is in the second position, the movable ratchet 44 fixed on the output shaft 51 cannot engage with the stationary ratchet 45. When the mode switching component 42 is driven backward by the adjusting sleeve 31, and the mode switching component 42 is in the first position, the user applies external force to compress the output shaft 51 backward, allowing the movable ratchet 44 to engage with the stationary ratchet 45, thereby enabling the output shaft 51 to perform impact output. (Refer to...) Figure 10 The movable ratchet 44 can be partially housed within the mode switching component 42, and can be fitted onto the output shaft 51 using an interference fit or other fastening method. The stationary ratchet 45 faces the movable ratchet 44 and is fixedly installed within the mounting portion 121. The end faces of the movable ratchet 44 and the stationary ratchet 45 are ratchet tooth surfaces, and the distance between them corresponds to the rearward movement distance of the mode switching component 42. In the impact mode, the movable ratchet 44 moves closer to the stationary ratchet 45 along with the output shaft 51, causing the movable ratchet 44 to mesh with the stationary ratchet 45. The ratchet tooth surface of the movable ratchet 44 slides on the ratchet tooth surface of the stationary ratchet 45, thereby generating an impact effect.

[0081] Reference Figure 10The output shaft 51 can be connected to a working head to output power externally, or it can act as a working head itself to output power externally. Through the adjustment of the torque assembly 30 and the impact assembly 40, it can output power in different modes. The impact assembly 40 uses a bearing 46 to axially limit the output shaft 51. The front end of the bearing 46 engages with the stepped portion 511 formed on the output shaft 51 to limit the rearward movement of the output shaft 51, thereby switching the working mode of the electric drill 1 according to the position of the bearing 46 relative to the gearbox housing 12. The rear end of the bearing 46 engages with the moving ratchet 44 to limit the forward movement of the output shaft 51, preventing the output shaft 51 from dislodging from the front end of the electric drill 1. An elastic element 52 is provided between the bearing 46 and the output shaft 51. One end of the elastic element 52 abuts against the bearing 46, and the other end abuts against the stepped portion 511, applying an axially forward biasing force to the output shaft 51. When the electric drill 1 is in screw mode or drill mode, the bearing 46 is in the front limit position, which limits the output shaft 51 axially, preventing the output shaft 51 from contacting the moving ratchet 44 with the stationary ratchet 45. When the electric drill 1 is in impact mode, the bearing 46 moves axially backward under the drive of the adjusting sleeve 31. At this time, the workpiece surface presses against the output shaft 51 to make it move backward, and the output shaft 51 can contact the moving ratchet 44 with the stationary ratchet 45. Under the action of the elastic element 52, the two ratchet surfaces continue to slide relative to each other, thereby producing an impact effect.

[0082] However, during the switching of the working mode of the electric drill 1 using the aforementioned torque component 30 and impact component 40, the output shaft 51 will inevitably exhibit "play" or "misalignment". Figure 18 As shown, when the mode switch 42 is in the second position (away from the stationary ratchet 45, and the drill 1 is in screw or drill mode), the output shaft 51 extends forward a certain distance under the biasing force of the elastic element 52. Figure 18 The image shows the position of the electric drill 1 when it is in screw or drill mode, with the output shaft 51 extended forward until the front end of the moving ratchet 44 is limited by the bearing 46. At this point, as shown... Figure 18 An impact length X is formed between the stepped portion 511 of the output shaft 51 and the mode switching component 52. In this position, when the user uses the screw stop or drill stop of the electric drill 1, there will be a significant "play" in the output shaft 51 or the chuck connected to the output shaft 51. The user needs to press the output shaft 51 inward by the length X before tightening the screw or drilling. However, as... Figure 19 As shown, when the mode switch 42 is in the first position (near the stationary ratchet 45, the electric drill 1 is in the impact gear), the output shaft 51 is limited by the bearing 46 because the moving ratchet 44 abuts against the bearing 46, and an impact length L is formed between the stepped portion 511 of the output shaft 51 and the mode switch 42. Figure 18 The impact length X shown is equal to Figure 19 The impact length L is shown.

[0083] When using the electric drill with the above structure, the user experience will be affected by the "dummy" impact length X in screw mode or drill mode. Moreover, the existence of this "dummy" will also increase the overall length of the electric drill 1.

[0084] To address the issue of increased overall machine length and negative user experience caused by "play" in the output shaft 51 of the electric drill 1 during screw or drill modes, a limiting member 53 can be installed on the output shaft 51. This limiting member restricts the forward axial movement of the output shaft 51, reducing or even eliminating the "play" caused by the output shaft 51 extending forward during screw or drill modes. In some embodiments, the limiting member 53 can be a retaining ring or O-ring fixedly attached to the rear end of the output shaft 51. The front end of the retaining ring can abut against the planetary carrier or other components in the planetary gear set 22. In some embodiments, the retaining ring engages with the output shaft 51, causing the stepped portion 511 of the output shaft 51 to abut against the mode switching member 42. Figure 20 As shown, the impact length X between the stepped portion 511 of the output shaft 51 and the mode switching component 52 is 0. When the drill 1 is in screw or drill mode, the retaining spring limits the output shaft 51, preventing it from extending forward, thus completely eliminating the "play" that exists in the output shaft 51 in screw or drill mode. When the drill 1 is in impact mode, as... Figure 21 The snap ring and bearing 46 shown simultaneously limit the output shaft 51, preventing it from extending forward.

[0085] The following describes in detail the positional status of each component of the electric drill 1 in three modes: screw mode, drill mode, and impact mode, as well as the movement of each component of the electric drill 1 during mode switching.

[0086] Reference Figure 22 The gearbox housing 12, torque assembly 30, impact assembly 40, and output assembly 50 are assembled in this order to form the working head of the electric drill 1.

[0087] In some embodiments of this application, the electric drill 1 has three working modes: screw mode, drill mode, and impact mode. Switching between working modes is achieved by an adjusting sleeve 1. The user operates the adjusting sleeve 1 to rotate it around the shaft 101, thereby switching the electric drill 1 between the three working modes. The output shaft 51 also corresponds to a specific working mode, outputting different forms of power. During the user's operation of the adjusting sleeve 1, the power output by the output shaft 51 varies depending on its stopping position.

[0088] Corresponding to the three working modes of the electric drill 1, the adjusting sleeve 31 has three stop positions: a first stop position, a second stop position, and a third stop position. When the adjusting sleeve 31 stops at any position between the first stop position and the second stop position, the electric drill 1 is in screw mode; when the adjusting sleeve 31 stops at the second stop position, the electric drill 1 is in drill mode; when the adjusting sleeve 31 stops at the third stop position, the electric drill 1 is in impact mode.

[0089] Reference Figure 4 When the adjusting sleeve 31 stops at the first stop position, the adjusting nut 32 is located at the front end. As the user continues to rotate the adjusting sleeve 31, the adjusting nut 32 is driven by the adjusting sleeve 31 to move linearly backward, thereby continuously changing the compression amount of the compression spring 33. The different compression amounts of the compression spring 33 correspond to different torque thresholds set by the electric drill 1 in screw mode. When the torque acting on the output shaft 51 exceeds the torque threshold limited by the compression spring 33, the clutch mechanism 23 will cut off the torque output from the motor 21 to the output shaft 51. The further the adjusting nut 32 moves backward, the greater the torque threshold limited by the electric drill 1.

[0090] The adjusting sleeve 31 continues to rotate, thereby driving the adjusting nut 32 to move backward in a straight line until the protrusion of the second mating surface 322 on the adjusting nut 32 abuts against the protrusion of the first mating surface 342 on the stop washer 34 (see reference). Figure 8 When the adjusting sleeve 31 is in the second stop position, the electric drill 1 is in the drill stop position, and the clutch mechanism 23 will not cut off the torque output from the motor 21 to the output shaft 51.

[0091] As the adjusting sleeve 31 continues to rotate from the second stop position, it drives the shift washer 34 to rotate and simultaneously drives the adjusting nut 32 to continue moving backward in a straight line until the outward protrusion of the second mating surface 322 on the adjusting nut 32 engages with the inward concave portion of the first mating surface 342 on the shift washer 34. At this point, the adjusting sleeve 31 is in the third stop position. At this time, the drill 1 is in impact mode, the impact assembly 40 is in drive mode, and the output shaft 51 outputs impact power. During the rotation of the adjusting sleeve 31 from the second stop position to the third stop position, the adjusting sleeve 31 can engage with the second arm 422 via the transmission flange 313, thereby driving the mode switching component 42 from... Figure 11 or Figure 20 The first position shown is moved to, as Figure 12 or Figure 21 The second position shown puts the impact assembly 40 in a driving state. At this time, the output shaft 51 can move axially backward, so that the moving ratchet 44 can engage with the stationary ratchet 45, thereby allowing the output shaft 51 to output impact power to the outside.

[0092] Once the adjusting sleeve 31 reaches the third stop position, it can no longer rotate forward. The user must drive the adjusting sleeve 31 in the reverse direction to rotate it from the third stop position to the second stop position. During this process, since the adjusting sleeve 31 and the mode switching component 42 are connected to the second arm 422 via the transmission flange 313, the transmission flange 313 is separated from the second arm 422 when the adjusting sleeve 31 rotates in the reverse direction, and the adjusting sleeve 31 cannot drive the mode switching component 42 to rotate in the reverse direction. Therefore, the reset component 43 is needed to drive the mode switching component 42 from the second position to the first position, at which point the electric drill 1 switches from the impact mode to the drill mode.

[0093] As the adjusting sleeve 31 continues to rotate in the opposite direction, from the second stop position to the first stop position, the adjusting sleeve 31 drives the adjusting nut 32 to move forward in a straight line. The further the adjusting nut 32 moves forward, the smaller the torque threshold limit set by the electric drill 1 becomes.

[0094] According to the electric drill 1 provided in this application, under the premise that its structure can meet the requirement of having three working modes, the original ring support used for switching working modes is omitted, so that the thickness of the electric drill 1 is reduced by at least one ring support in the axial length, and the overall length of the machine is shortened.

[0095] 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

1. A power tool characterized by, The power tool includes: shell; The output shaft has a stepped portion on its front side that restricts the rearward movement of the output shaft; A transmission assembly, housed in the housing, drives the output shaft; An impact assembly includes a stationary ratchet and a movable ratchet, wherein the stationary ratchet is fixedly connected to the housing, and the movable ratchet is fixedly connected to the output shaft and disposed opposite to the stationary ratchet; A mode switching component is located between the moving ratchet and the stepped portion and rotatably supports the output shaft. The mode switching component can be switched in the front-back direction to a first position close to the stationary ratchet or a second position far away from the stationary ratchet. An elastic element, one end of which presses against the mode switching element, and the other end of which presses against the output shaft; When the mode switching component is in the first position, the elastic element presses the moving ratchet against the mode switching component through the output shaft to disengage the moving ratchet from the stationary ratchet and form an impact length L between the stepped portion and the mode switching component, compressing the output shaft backward, and the stationary ratchet meshes with the moving ratchet. When the mode switching component is in the second position, it compresses the output shaft backward, and the stationary ratchet and the moving ratchet cannot mesh. The power tool also includes a limiting component that is held at the rear side of the output shaft. The elastic component presses the limiting component against the transmission assembly through the output shaft, forming an impact length X between the stepped portion and the mode switching component. The impact length X is less than the impact length L.

2. The power tool according to claim 1, characterized in that, The mode switching component supports the output shaft via a rotating bearing. The bearing is located between the moving ratchet and the stepped portion, and its outer ring is fixedly connected to the mode switching component, while its inner ring is clearance-fitted with the output shaft.

3. The power tool according to claim 2, characterized in that, The elastic element is a conical spring, with its front end pressing against the output shaft and its rear end pressing against the inner ring of the bearing.

4. The power tool according to claim 2, characterized in that, When the mode switching component is in the second position, with the impact length X being 0, the stepped portion abuts against the front end of the bearing.

5. The power tool of claim 1, wherein, The transmission assembly includes a motor and a planetary gear set, and the motor drives the output shaft through the planetary gear set. The limiting component is a snap ring or an O-ring, which presses against the planetary gear set.

6. The power tool according to claim 1, characterized in that, The power tool further includes an adjustment sleeve, which is rotatably supported by the housing and drives the mode switching component to move in the front-back direction via a transmission guide device. The transmission guide device includes: A guide plate, which is fixedly connected to the housing, has guide protrusions extending toward the mode switching component; A guide groove is formed in the outer shell, and the guide groove and the end face of the guide protrusion together form a guide path; A first arm is formed in the mode switcher and passes through the guide groove. The first arm is driven by the mode switcher to move along the guide path. The mode switching component has a second arm extending toward the adjustment sleeve; A transmission flange is provided on the adjusting sleeve, which extends toward the mode switching component. The transmission flange engages with the second arm to transmit the external force received by the adjustment sleeve to the mode switching member, causing the mode switching member to move along the guide path.

7. The power tool of claim 6, wherein, A guide slope is also formed between the inner end face of the guide plate and the inner end face of the guide protrusion to form a guide path between the two. When the first arm abuts against the inner end face of the guide plate, the mode switching component is in the second position; When the first arm abuts against the inner end face of the guide protrusion, the mode switching component is in the first position.

8. The power tool of claim 7, wherein, The inner end face of the guide protrusion is formed with a guide rib to abut against the first arm.

9. The power tool of claim 6, wherein, The mode switching component is also connected to a reset component, which is used to drive the mode switching component to move from the first position to the second position along the guide path when the transmission flange is separated from the second arm.

10. The power tool of claim 9, wherein, The reset component is a torsion spring with connecting feet at both ends. One connecting foot is fixedly connected to the stationary ratchet, and the other is fixedly connected to the inner wall of the mode switching component.

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