CN117697697A - Electric tool - Google Patents

Abstract

The present application provides a power tool, relating to a mode switching system thereof, the power tool comprising: a mode switching member switchable in a front-rear direction to a first position close to the static ratchet or a second position away from the static ratchet; when the mode switching piece is positioned at the second position, the output shaft is compressed towards the rear, the static ratchet wheel and the movable ratchet wheel cannot be meshed, the electric tool further comprises a limiting piece clamped at the rear side of the output shaft, and the elastic piece is used for propping the limiting piece against the transmission assembly through the output shaft and forming an impact length X between the step part and the mode switching piece. The application provides an electric tool, it only adopts an adjusting collar to carry out torsion adjustment and mode switching, and has saved an annular support in axial structure to electric tool's complete machine length has been reduced.

Description

Electric tool

Technical Field

The present disclosure relates to the field of power tools, and in particular, to a mode switching system for a power tool.

Background

Electric drills with a percussive function typically have several modes of operation, such as screw flights, drill flights, percussive flights, etc. When using the screw gear, the control gear must be adjusted to the screw gear; at this time, the percussion drill can decide when to jump gear according to the screw gear torque setting, and the percussion drill rotating motor continuously rotates during jump gear, but the screw driver keeps a static state, and the percussion drill cannot output the maximum torque. When the electric drill gear is used, the rotary motor and the front end drill bit always keep the same action, and the maximum torque force is output to maintain the gear jump. When the impact gear is used, besides the original electric drill gear function, the impact mechanism is started to provide impact, so that drilling operation can be more effectively carried out on cement walls or other hard objects.

However, in the existing electric drill impact structure, a bracket part is arranged on a shaft, and the working mode of the electric drill is switched by limiting the bracket part axially, for example, the Chinese patent application publication No. CN211053606U discloses that the annular bracket is matched with a mode switching sleeve to switch the working mode, and the torsion of a screw gear is adjusted by adopting a torsion adjusting sleeve.

Disclosure of Invention

To the not enough of prior art, the aim at of this application provides electric tool, and it only adopts an adjusting collar to carry out torsion adjustment and mode switching, and has saved an annular support in axial structure to electric tool's complete machine length has been reduced.

Therefore, the application provides the following technical scheme: a power tool, the power tool comprising:

a housing;

an output shaft having a stepped portion on a front side thereof for restricting rearward movement of the output shaft;

a transmission assembly which is accommodated in the housing and drives the output shaft;

the impact assembly comprises a static ratchet wheel and a dynamic ratchet wheel, wherein the static ratchet wheel is fixedly connected in the shell, and the dynamic ratchet wheel is fixedly connected with the output shaft and is arranged opposite to the static ratchet wheel 45;

a mode switching member which is located between the movable ratchet and the stepped portion and rotatably supports the output shaft, the mode switching member being switchable in a front-rear direction to a first position close to the stationary ratchet or a second position away from the stationary ratchet;

an elastic member, one end of which abuts against the mode switching member, and the other end of which abuts against the output shaft;

when the mode switching piece is positioned at a first position, the elastic piece presses the movable ratchet wheel against the mode switching piece through the output shaft so as to separate the movable ratchet wheel from the static ratchet wheel, form an impact length L between the step part and the mode switching piece, compress the output shaft towards the rear, and the static ratchet wheel is meshed with the movable ratchet wheel;

when the mode switching part is positioned at the second position, the output shaft is compressed towards the rear, the static ratchet wheel and the movable ratchet wheel cannot be meshed, the electric tool further comprises a limiting part clamped at the rear side of the output shaft, the elastic part is used for propping the limiting part against the transmission assembly through the output shaft, the impact length X between the step part and the mode switching part is formed, and the impact length X is smaller than the impact length L.

The further improvement scheme is as follows: the mode switching piece rotatably supports the output shaft through a bearing;

the bearing is positioned between the movable ratchet wheel and the step part, the outer ring of the bearing is fixedly connected with the mode switching piece, and the inner ring of the bearing is in clearance fit with the output shaft.

The further improvement scheme is as follows: the elastic piece is a conical spring, the front end of the elastic piece is propped against the output shaft, and the rear end of the elastic piece is propped against the inner ring of the bearing.

The further improvement scheme is as follows: when the mode switching member is located at the second position, the stepped portion abuts against the front end of the bearing in a state where the impact length X is 0.

The further improvement scheme is as follows: the transmission assembly comprises a motor and a planetary gear set, and the motor drives the output shaft through the planetary gear set;

the limiting piece is a clamp spring or an O-shaped ring and is propped against the planetary gear set.

The further improvement scheme is as follows: the electric tool further includes an adjusting sleeve rotatably supported to the housing, the mode switching member is driven to move in a front-rear direction by a transmission guide device, and the transmission guide device includes:

the guide plate is fixedly connected to the shell, and a guide lug extends towards the mode switching piece;

the guide groove is formed in the shell, and the guide groove and the end face of the guide lug are arranged together to form a guide path;

a first arm formed at the mode switching member and passing through the guide groove, the first arm being driven by the mode switching member to be movable along the guide path;

a second arm, the mode switching member extending toward the adjustment sleeve;

a drive flange, the adjustment sleeve extending toward the mode switch member;

the transmission flange is overlapped with the second arm to transmit the external force received by the adjusting sleeve to the mode switching member so that the mode switching member moves along the guide path.

The further improvement scheme is as follows: a guide inclined plane is formed between the inner end surface of the guide plate and the inner end surface of the guide lug so as to form a guide path between the guide plate and the guide lug;

when the first arm abuts against the inner end face of the guide plate, the mode switching piece is located at a second position;

when the first arm abuts against the inner end face of the guide lug, the mode switching piece is located at a first position.

The further improvement scheme is as follows: the inner end surface of the guide lug is provided with a guide rib to be abutted against the first arm.

The further improvement scheme is as follows: the mode switching member is also connected with a reset member for driving the mode switching member to move from a first position to a second position along the guide path when the transmission flange is separated from the second arm.

The further improvement scheme is as follows: the reset piece is a torsion spring, two ends of the reset piece are respectively provided with a connecting pin, one connecting pin is fixedly connected with the static ratchet wheel, and the other connecting pin is fixedly connected with the inner wall of the mode switching piece.

Compared with the prior art, the application has the following beneficial effects:

1. the utility model provides an electric tool constructs the adjusting sleeve into two segmentation strokes, adjusts torsion size at first section stroke, and at second section stroke drive mode switching piece removal in order to switch operating mode, and the mode switching piece is the cover to be established in output shaft periphery, and this kind of electric tool has saved the length of mode switching key spare in axial structure, only adopts an adjusting sleeve to adjust torsion and switch operating mode moreover, and the reduction complete machine length that can to a great extent.

2. The application provides electric tool, but the mode switching piece of adoption axial displacement is spacing back to output shaft axial, and the output shaft can be in screw shelves, drill mode down stretch out and produce "virtual position", makes complete machine length increase, and this application adopts the locating part to carry out spacing to the output shaft to prevent that it from stretching out forward, avoids "virtual position" production for this purpose.

3. The utility model provides an electric tool is established at output shaft outlying mode switching piece by the cover and carries out axial spacing to the output shaft, consequently the output shaft only with mode switching piece sliding friction under the impact mode, with the shell between do not take place friction, electric tool can not wearing and tearing to the shell under the impact mode.

Drawings

Fig. 1 is a schematic view of a power drill according to a preferred embodiment of the present application;

fig. 2 is a schematic view of the internal structure of the drill shown in fig. 1;

FIG. 3 is a schematic view of the structure of the drill gear housing of FIG. 1;

FIG. 4 is a schematic illustration in partial cross-section of the internal structure of the gearbox housing of FIG. 3;

FIG. 5 is a schematic view of the structural cooperation of the drill sleeve and adjustment nut of FIG. 1;

fig. 6 is a schematic view of the clutch mechanism of the electric drill of fig. 1;

FIG. 7 is a schematic view of the structural cooperation of the drill adjustment nut and shift washer of FIG. 1;

fig. 8 is a schematic view of the drill adjustment nut and shift washer of fig. 1 in a drill mode;

fig. 9 is a schematic view of the drill adjustment nut and shift washer of fig. 1 in an impact mode;

FIG. 10 is a schematic view of the internal structure of the drill gear housing of FIG. 1;

fig. 11 is a schematic view of the power drill mode switching member of fig. 1 in a first position;

fig. 12 is a schematic view of the drill mode switching member of fig. 1 in a second position;

fig. 13 is a schematic view of the structural cooperation of the drill guide plate and the mode switching member of fig. 1;

fig. 14 is a schematic view of the structure of the drill guide plate of fig. 1;

FIG. 15 is a schematic view of the structural cooperation of the drill mode switching member and compression spring of FIG. 1;

fig. 16 is a schematic view of the structure of the drill adjustment sleeve of fig. 1;

FIG. 17 is a top plan view of the drill adjustment sleeve of FIG. 1 in driving engagement with a mode switching member;

fig. 18 is a schematic view of the internal structure of the gear housing of the drill of fig. 1 in a screw or drill mode when the drill is not provided with a stop;

fig. 19 is a schematic view of the internal structure of the gear housing of the power drill of fig. 1 in an impact mode when no stop is provided;

fig. 20 is a schematic view showing the internal structure of the gear housing of the power drill of fig. 1 in a screw or drill mode when the stop is provided;

fig. 21 is a schematic view showing the internal structure of the gear housing of the electric drill of fig. 1 in an impact range mode when the stopper is provided;

fig. 22 is an exploded view of the assembly of the drill gearbox housing of fig. 1.

Meaning of reference numerals in the drawings:

1. an electric drill is used for the electric drill,

10. the shell, 11, the main body shell, 12, the gear box shell, 121, the mounting part, 122, the stop convex rib, 123, the guide groove, 13 and the handle part,

20. the transmission component, 21, the motor, 22, the planetary gear set, 23, the clutch mechanism, 231, the internal gear, 232, the steel ball, 233, the pin,

30. the torque component, 31, the adjusting sleeve, 311, the first screw thread, 312, the clamping groove, 313, the transmission flange, 32, the nut, 321, the second screw thread, 322, the second joint surface, 323, the mounting post, 33, the compression spring, 34, the jump stop washer, 341, the clamping block, 342, the first joint surface, 343, the abutting ring surface, 35, the rotation stop washer,

40. impact assembly, 41, guide plate, 411, guide projection, 412, guide slope, 413, guide rib, 42, mode switching member, 421, first arm, 422, second arm, 423, fitting slope, 43, reset member, 431, connection leg, 44, movable ratchet, 45, static ratchet, 46, bearing,

50. output assembly, 51, output shaft, 511, step, 52, elastic piece, 53, spacing piece.

Detailed Description

The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Words such as "upper", "lower", "front", "rear", and the like, indicating an azimuth or a positional relationship are merely based on the azimuth or the positional relationship shown in the drawings, and are merely for convenience of description and to simplify the description, and do not indicate or imply that the apparatus/elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present application.

The following describes specific embodiments of the present application with reference to the drawings.

Referring to fig. 1, for convenience of explanation, the electric tool provided in the present application uses an electric drill 1 as an example, and the electric drill 1 can be switched between a screw gear, a drill gear and an impact gear to meet different use requirements of users.

Referring to fig. 2, the electric drill 1 includes a housing 10, a transmission assembly 20 supported by the housing 10, a torsion assembly 30, a striking assembly 40, and an output assembly 50. The transmission assembly 20 transmits power to the output assembly 50, and drives the output shaft 51 of the output assembly 50 to rotate around the axis 101 to output power, and the torsion assembly 30 and the impact assembly 40 are used for changing the output torque and output form of the output shaft 51.

For the convenience and clarity of description of the technical solution, the following definitions are made: the direction of the axis 101 defining the rotation of the output shaft 51 and the direction parallel to the axis 101 are axial; a radial direction defining a circumferential direction about the axis 101 as a central axis; defining the power output direction along the output shaft 51 as the front; the direction opposite to the power output of the output shaft 51 is defined as the rear.

Referring to fig. 2, the housing 10 includes a main housing 11 and a gear case housing 12, which may be integrally formed or fastened by fasteners. The main housing 11 and the gear housing 12 may provide support and accommodation space for the drive assembly 20. The main body housing 11 may also be formed with a handle portion 13 for a user to grasp.

The transmission assembly 20 includes a motor 21 supported by the main body housing 11, a planetary gear set 22 supported by the gearbox housing 12, and a clutch mechanism 23. The power source provided by the motor 21 is transmitted to the output shaft 51 by the planetary gear set 22, and the planetary gear set 22 may be constituted by one-stage or multi-stage gear sets. The clutch mechanism 23 is configured to interrupt the torque output of the motor 21 to the output shaft 51 when the torque applied to the output shaft 51 is greater than a set threshold.

Referring to fig. 3, a mounting portion 121 for supporting the impact assembly 30 is formed at the front end of the gear case housing 12, and in order to streamline and coordinate the overall appearance of the housing 10, the diameter of the mounting portion 121 may be set smaller than other portions of the gear case housing 12 so as to provide a sufficient mounting space for supporting the torsion assembly 30 and the impact assembly 40. Of course, the mounting positions of the torsion assembly 30 and the impact assembly 40 are not limited thereto, and the torsion assembly 30 and the impact assembly 40 may be disposed at appropriate positions according to the actual structure of the electric drill 1.

Referring to fig. 4, 5 and 6, the torsion assembly 30 for adjusting the output torsion when the drill 1 is in screw gear includes an adjustment sleeve 31 rotatably supported on the mounting portion 121, an adjustment nut 32 axially movable along the mounting portion 121, and a biasing member coupled to the adjustment nut 32. The inner wall of the adjustment sleeve 31 is formed with a first screw 311, and the outer circumferential surface of the adjustment nut 32 is formed with a second screw 321 which is coupled to the first screw 311. The outer circumferential surface of the mounting portion 121 is formed with a stopper rib 122 for restricting the circumferential rotation of the adjustment nut 32, the inner wall profile of the adjustment nut 32 is adapted to the outer circumferential profile of the mounting portion 121, and when the adjustment sleeve 31 is rotated, the adjustment nut 32 can be moved axially along the mounting portion 121 to compress the biasing members to different degrees, thereby adjusting the output torque of the electric drill 1 in screw range in combination with the clutch mechanism 23. Wherein the biasing member may be embodied as a compression spring 33, as shown in fig. 4. The clutch mechanism 23 includes a ring gear 231 drivingly connected to the planetary gear set 22, a steel ball 232 and a pin 233 held in engagement with the front end surface of the ring gear 231, and a compression spring 33 for biasing the pin 233. The front end face of the ring gear 231 is provided with a protrusion, under normal condition, the steel ball 232 is pressed on the front end face of the ring gear 231 due to the force of the compression spring 33, so that the protrusion of the front end face of the ring gear 231 can not pass over the steel ball 232, the ring gear 231 is fixed relative to the housing 10, and the planetary gear set 22 acting with the ring gear 231 drives the output shaft 51 to rotate. When the torque applied to the output shaft 51 exceeds the torque threshold provided by the compression spring 33, the torque applied to the ring gear 231 by the planetary gear set 22 is sufficient to overcome the force of the compression spring 33 applied to the ring gear 231, and the projection on the front end surface of the ring gear 231 passes over the steel ball 232, at this time, the ring gear 231 rotates relative to the housing 10, the output shaft 51 is in a clutched state, and the torque output thereof is cut off, i.e., a jump takes place.

Referring to fig. 6, the torsion assembly 30 further includes a detent washer 35 secured to the mounting portion 121 as a detent washer 34, zhou Xianggu that is rotatable circumferentially with the adjustment sleeve 31. The front end surface of the jump ring 34 is formed with a first engagement surface 342 for engaging with the adjustment nut 32 and an abutment annular surface 343 for engaging with the rotation stop washer 35. The trip stop washer 34 is of an annular structure, three clamping blocks 341 can be integrally formed on the outer peripheral surface of the trip stop washer, the clamping grooves 312 matched with the clamping blocks 341 can axially extend on the inner wall of the adjusting sleeve 31, and therefore the trip stop washer 34 can be inserted into the adjusting sleeve 31 through the matching of the clamping blocks 341 and the clamping grooves 312, and the trip stop washer 34 can rotate along with the circumferential rotation of the adjusting sleeve 31. In addition, the clamping block 341 may protrude from the front end surface of the jump stop washer 34, so as to increase the clamping area of the clamping block 341 and the clamping groove 312, thereby improving the clamping strength of the clamping block 341 and the clamping groove. The adjusting nut 32 moves linearly back and forth, so that the compression springs 33 are compressed to different degrees, the front ends of the compression springs 33 are connected with the adjusting nut 32, the rear ends of the compression springs 33 are abutted against the jump stop washers 34, and the biasing force of the compression springs 33 is transmitted to the pin 233 and the steel ball 232 through the jump stop washers 34. However, the adjusting nut 32 is locked circumferentially and cannot be rotated, while the jump ring 34 rotates with the adjusting sleeve 31, so that there is a relative rotational movement of the rear end of the compression spring 33 and the jump ring 34. If it is desired to realize such an assembly among the adjustment nut 32, the compression spring 33, and the jump ring 34, the compression spring 33 may be implemented as a large spring which is fitted around the adjustment nut 32 and surrounds the outer circumference of the gear housing 12, however, if the compression spring 33 is implemented as a large spring, the elastic force variation interval thereof is small, resulting in a small torsion adjustment range of the electric drill 1 as a whole. Therefore, the compression spring 33 may be implemented as a small spring, a plurality of small springs are circumferentially distributed on the outer periphery of the gear case housing 12, a plurality of mounting posts 323 are circumferentially formed at the rear end of the adjusting nut 32, the mounting posts 323 extend rearward, and each small spring is sleeved on the mounting post 323. In order to avoid that the compression spring 33 applies a biasing force to the clutch mechanism 23 due to circumferential friction between the rear end of the small spring and the jump ring 34, a rotation stopping washer 35 may be disposed between the compression spring 33 and the jump ring 34, the rotation stopping washer 35 may have a ring-shaped structure, the inner wall profile of the rotation stopping washer 35 is adapted to the outer circumferential profile of the mounting portion 121, the circumferential rotation of the rotation stopping washer 35 is limited by a stop rib 122 on the outer circumference of the mounting portion 121, the front end surface of the rotation stopping washer 35 abuts against the compression spring 33, and the rear end surface abuts against the jump ring 34. Referring to fig. 7, the portion of the front end surface of the jump ring 34 for abutting against the anti-rotation pad 35 is an abutting annular surface 343, the abutting annular surface 343 and the first joint surface 342 may be in a coaxial annular structure, and the abutting annular surface 343 is located in a ring surrounded by the first joint surface 342. A first engagement surface 342 on the jump stop washer 34 is adapted to engage a second engagement surface 322 on the adjustment nut 32. The first and second engagement surfaces 342, 322 each have spaced apart outer and inner protrusions and recesses, which have two engagement states: a first engagement state in which the outer protrusions of the two are in contact with each other, and a second engagement state in which one of the outer protrusions of the two is fitted into the inner recess of the other. In some embodiments, the first joint surface 342 and the second joint surface 322 may be implemented as annular wave surfaces with size and contour matching as shown in fig. 7, and the two joint states may be: in the abutting state in which the peak and the peak are engaged as shown in fig. 8, and in the fitted state in which one peak and the other trough are engaged as shown in fig. 9, the pitch between the adjusting nut 32 and the jump ring 34 in the fitted state is smaller than the pitch in the abutting state. With this structure, when the user rotates the adjustment sleeve 31 to drive the adjustment nut 32 to gradually compress the compression spring 33 until the crest of the second engaging surface 322 on the adjustment nut 32 abuts against the crest of the first engaging surface 342, the electric drill 1 is switched from the screw stage to the drill stage; since the space between the jump washer 34 and the adjusting nut 32 in the engagement state is smaller than the space between the two engagement states, the difference between the two engagement states allows the adjusting nut 32 to move backward, so that the user can rotate the adjusting sleeve 31 continuously to switch the two engagement states from the engagement state to the engagement state, and the electric drill 1 can also switch from the drill position to the impact position.

When the drill 1 is switched to the striking mode, the striking assembly 40 can drive the output shaft 51 to strike. Referring to fig. 10, the striking unit 40 includes a guide plate 41 fixed to the front end of the gear case housing 12, a mode switching member 42 movable backward by the driving of the adjustment sleeve 31, a reset member 43 connected to the mode switching member 42, a movable ratchet 44 fixed to the output shaft 51, and a static ratchet 45 fixed to the inside of the gear case housing 12. The guide plate 41 may be fixed to the front end surface of the gear case housing 12 by a screw or other fastener, and the rear end surface thereof is provided with a guide protrusion 411 extending rearward, referring to fig. 13 and 14, the rear end surface of the guide plate 41 is formed with three guide protrusions 411 distributed circumferentially, and a guide inclined surface 412 is formed between the guide protrusion 411 and the rear end surface of the guide plate 41, and the mode switching member 42 moves from the rear end surface of the attaching guide plate 41 to the attaching guide protrusion 411 along the guide inclined surface 412, completing the action of moving rearward under the drive of the adjustment sleeve 31, thereby moving the mode switching member 42 from the second position shown in fig. 11 to the first position shown in fig. 12. In order to reduce frictional resistance between the mode switching member 42 and the guide inclined surface 412 during the relative movement, a guide rib 413 may be provided on the end surface of the guide projection 411 along the length extending direction thereof, and the mode switching member 42 moves in contact with the guide rib 413, thereby reducing frictional resistance between the mode switching member 42 and the guide inclined surface 412 by reducing the contact area therebetween.

Referring to fig. 10, 11 and 15, the mode switching member 42 may have an annular sleeve structure, and a bearing 46 is fixed to an inner wall thereof, and the bearing 46 is in clearance fit with the output shaft 51. In the mode switching structure of the ring bracket, the bearing is fixedly sleeved on the output shaft, and the output shaft can generate sliding friction with the shell during impact, so that the shell 10 is worn. In some embodiments of the present application, only the output shaft 51 slides relatively to the inner ring of the bearing 46 when the output shaft 51 impacts, and does not slide relatively to the housing 10, so that the housing 10 is prevented from being worn.

Further, the outer circumference of the mode switching member 42 radially extends with first arms 421 corresponding to the guide bosses 411 in position and number one by one. The outer periphery of the mode switching member 42 is also radially extended with a second arm 422, and the inner wall of the above-mentioned adjustment sleeve 31 is formed with a transmission flange 313 (shown in fig. 16) engaged therewith. When the electric drill 1 is switched from the drill position to the impact position, the user rotates the adjusting sleeve 31, and at this time, the side wall of the transmission flange 313 is overlapped with the side wall of the second arm 422, so that the adjusting sleeve 31 can drive the mode switching member 42 to rotate a certain angle, and during the rotation of the mode switching member 42, the second arm 422 moves along the guide inclined surface 412 from the rear end surface of the attaching guide plate 41 to the attaching guide protruding block 411, so that the mode switching member 42 moves backward with the bearing 46, and the mode switching member 42 moves from the second position to the first position to provide the impact length for the output shaft 51.

Referring to fig. 10, a reset member 43 is also connected to the mode switching member 42, and can reset the mode switching member 42 in the axial direction and the radial direction. Since the adjustment sleeve 31 is overlapped with the second arm 422 through the transmission flange 313 to drive the mode switching member 42 to rotate in one direction, so that the mode switching member 42 moves backward while rotating under the action of the guide plate 41, when the adjustment sleeve 31 rotates in the opposite direction, the mode switching member 42 needs to be reset to the original position by means of the reset member 43, and the reset member 43 needs to reset the mode switching member 42 in the axial direction and the mode switching member 42 in the circumferential direction, so that the reset member 43 can be implemented as a torsion spring as shown in fig. 17. In fig. 17, the reset member 43 has connection pins 431 formed at both ends thereof, one end of which can be fixedly connected to the gear case housing 12 or the static ratchet 45, and the other end of which is fixedly connected to the mode switching member 42. When the adjustment sleeve 31 drives the mode switching member 42 to move along the guide track of the guide plate 41, the mode switching member 42 moves from the second position to the first position, which is not only rotated circumferentially but also moved axially rearward, corresponding to the reset member 43, which is compressed not only circumferentially but also axially, so that when the adjustment sleeve 31 rotates reversely to move the transmission flange 313 away from the second arm 422, the reset member 43 applies a biasing force not only to the mode switching member 42 circumferentially but also to the mode switching member 42 in the axial direction, so that the mode switching member 42 is reset from the first position to the second position.

The mode switching member 42 is for limiting the output shaft 51 in the axial direction rearward, and when the mode switching member 42 is in the second position, the movable ratchet 44 fixed to the output shaft 51 cannot be engaged with the static ratchet 45. When the mode switching member 42 is driven to move backward by the adjusting sleeve 31, and the mode switching member 42 is in the first position, the user applies an external force to compress the output shaft 51 backward, and the movable ratchet 44 can be engaged with the static ratchet 45, so that the output shaft 51 can perform impact output. Referring to fig. 10, the movable ratchet 44 may be partially enclosed in the mode switching member 42, and may be sleeved on the output shaft 51 by an interference fit or other fastening method, and the static ratchet 45 is opposite to the movable ratchet 44 and is fixedly mounted in the mounting portion 121. The opposite end surfaces of the movable ratchet 44 and the static ratchet 45 are ratchet surfaces, and the distance between the two corresponds to the distance of the mode switching member 42 moving backwards. In the impact gear mode, the movable ratchet 44 approaches the static ratchet 45 along with the output shaft 51, so that the movable ratchet 44 is meshed with the static ratchet 45, and the ratchet surface of the movable ratchet 44 slides on the ratchet surface of the static ratchet 45, thereby generating an impact effect.

Referring to fig. 10, the output shaft 51 may be connected to the working head to output power to the outside, or may be used as the working head to output power to the outside itself, and may output power of different modes to the outside through the adjustment of the torsion assembly 30 and the impact assembly 40. The impact assembly 40 adopts the bearing 46 to axially limit the output shaft 51, and the front end of the bearing 46 is matched with the step 511 formed on the output shaft 51 to limit the backward movement of the output shaft 51, so that the working mode of the electric drill 1 is switched according to the position of the bearing 46 relative to the gear box shell 12; the rear end of the bearing 46 cooperates with the movable ratchet 44 to limit forward movement of the output shaft 51, preventing the output shaft 51 from being removed from the front end of the drill 1. An elastic member 52 is provided between the bearing 46 and the output shaft 51, and one end of the elastic member 52 abuts against the bearing 46 and the other end abuts against the stepped portion 511, thereby applying an axially forward biasing force to the output shaft 51. When the electric drill 1 is in a screw gear or a drill gear, the bearing 46 is positioned at the front end limit position and axially limits the output shaft 51, so that the output shaft 51 cannot bring the movable ratchet 44 into contact with the static ratchet 45; when the electric drill 1 is in the impact gear, the bearing 46 is driven by the adjusting sleeve 31 to move backwards and axially, at the moment, the surface of the workpiece abuts against the output shaft 51 to move backwards, the output shaft 51 can bring the movable ratchet wheel 44 into contact with the static ratchet wheel 45, and the two ratchet faces continuously slide relatively under the action of the elastic piece 52, so that the impact effect is generated.

However, in the process of switching the working modes of the electric drill 1 by using the torsion assembly 30 and the impact assembly 40, the output shaft 51 must be in a "virtual position", that is, when the mode switching member 42 is in the second position (far from the static ratchet wheel 45 and the electric drill 1 is in a screw gear or a drill gear) as shown in fig. 18, the output shaft 51 extends forward by a distance under the biasing force of the elastic member 52, that is, when the electric drill 1 is in the screw gear or the drill gear, the output shaft 51 extends forward until the front end face of the movable ratchet wheel 44 is limited by the bearing 46, and then, an impact length X is formed between the step 511 of the output shaft 51 and the mode switching member 52 as shown in fig. 18, and in this position, when a user uses the screw gear or the drill gear of the electric drill 1, the output shaft 51 or the chuck connected to the output shaft 51 has a larger "virtual position", so that the user needs to press the output shaft 51 inward by the length X and then starts screwing or drilling. While in the first position of the mode switching member 42 (near the stationary ratchet 45, the electric drill 1 is in the impact position) as shown in fig. 19, the output shaft 51 is restrained by the bearing 46 due to the abutment of the movable ratchet 44 against the bearing 46, and the impact length L is formed between the stepped portion 511 of the output shaft 51 and the mode switching member 42. The impact length X shown in fig. 18 is equal to the impact length L shown in fig. 19.

When the electric drill with the structure is used by a user, the use experience can be influenced by the existence of a virtual position of the impact length X in a screw gear or drill gear mode, and the whole length of the electric drill 1 can be increased due to the existence of the virtual position.

In order to solve the problem that the output shaft 51 of the electric drill 1 has a "virtual position" when in screw gear or drill gear, which results in the increase of the overall length and affects the user experience, a limiting member 53 may be disposed on the output shaft 51, which limits the axial forward direction of the output shaft 51, so as to reduce or even eliminate the "virtual position" generated by the output shaft 51 extending forward when in screw gear or drill gear. In some embodiments, the limiting member 53 may be implemented as a snap spring or an O-ring fixedly clamped to the rear end of the output shaft 51, and the front end of the snap spring may abut against a planet carrier or other members of the planetary gear set 22. In some embodiments, the jump ring is clamped to the output shaft 51, so that the step 511 of the output shaft 51 abuts against the mode switching member 42, and at this time, as shown in fig. 20, an impact length X is formed between the step 511 of the output shaft 51 and the mode switching member 52, and when the electric drill 1 is in a screw gear or a drill gear, the jump ring limits the output shaft 51 so that the jump ring cannot extend forward, so as to completely eliminate a "virtual position" of the output shaft 51 in the screw gear or the drill gear mode. When the electric drill 1 is in the impact gear, as shown in fig. 21, the snap spring and the bearing 46 limit the output shaft 51 at the same time, so that the output shaft cannot extend forwards.

The positional states of the respective members of the electric drill 1 in the three modes of the screw range mode, the drill range mode, and the impact range mode, and the movement of the respective members of the electric drill 1 during the mode switching are specifically described below.

Referring to fig. 22, the gearbox housing 12, the torsion assembly 30, the impact assembly 40, and the output assembly 50 are assembled in this order of assembly as the working head portion of the power drill 1.

In some embodiments of the present application, the drill 1 has three modes of operation: screw gear mode, drill gear mode, impact gear mode. The switching of the working modes is realized by the adjusting sleeve 1, and a user operates the adjusting sleeve 1 to rotate around the shaft 101, so that the electric drill 1 is switched among three working modes, the output shaft 51 also corresponds to one working mode, and different forms of power are output to the outside. The power output from the output shaft 51 varies depending on the stop position of the user during the rotation of the adjustment sleeve 1.

The adjustment sleeve 31 has three rest positions corresponding to the three modes of operation of the drill 1 described above: a first stop bit, a second stop bit, and a third stop bit. 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 a screw gear mode; when the adjusting sleeve 31 stops at the second stop position, the electric drill 1 is in a drill mode; when the adjustment sleeve 31 is stopped in the third stop position, the electric drill 1 is in the impact range mode.

Referring to fig. 4, the adjustment sleeve 31 is stopped at the first stop position, and the adjustment nut 32 is located at the front end. As the user continues to rotate the adjustment sleeve 31, the adjustment nut 32 is driven by the adjustment sleeve 31 to move linearly rearward, thereby continually changing the amount of compression of the compression spring 33, and the compression spring 33 is subjected to different amounts of compression corresponding to different torque thresholds set by the drill 1 in the screw gear mode, and the clutch mechanism 23 cuts off the torque output from the motor 21 to the output shaft 51 when the torque applied to the output shaft 51 exceeds the torque threshold defined by the compression spring 33. The more rearward the adjustment nut 32 is moved, the greater the torque threshold defined by the drill 1.

The adjusting sleeve 31 continues to rotate so as to continuously drive the adjusting nut 32 to linearly move backwards until the outer part of the second joint surface 322 on the adjusting nut 32 abuts against the outer part of the first joint surface 342 on the jump ring 34 (refer to fig. 8), the adjusting sleeve 31 is located at the second stop position, and at this time, the electric drill 1 is a drill stop, and the clutch mechanism 23 does not cut off the torque output from the motor 21 to the output shaft 51.

When the adjusting sleeve 31 continues to rotate from the second stop position, the adjusting sleeve 31 drives the jump stop washer 34 to rotate and simultaneously drives the adjusting nut 32 to move linearly backwards until the outer protruding part of the second joint surface 322 on the adjusting nut 32 is engaged with the inner recessed part of the first joint surface 342 on the jump stop washer 34, and the adjusting sleeve 31 is located at the third stop position. At this time, the electric drill 1 is in a driving state, the impact assembly 40 is in a driving state, and the output shaft 51 outputs impact power to the outside. During the rotation of the adjustment sleeve 31 from the second stop position to the third stop position, the adjustment sleeve 31 may overlap the second arm 422 via the transmission flange 313 so as to move the driving mode switching member 42 from the first position shown in fig. 11 or 20 to the second position shown in fig. 12 or 21, so that the impact assembly 40 is in a driving state, and at this time, the output shaft 51 may move axially rearward, so that the driving ratchet 44 may abut the static ratchet 45, and thus the output shaft 51 outputs impact power to the outside.

After the adjustment sleeve 31 reaches the third stop position, the forward rotation cannot be continued, and the user can only reverse-drive the adjustment sleeve 31 to reverse-rotate from the third stop position to the second stop position. In this process, since the adjustment sleeve 31 and the mode switching member 42 are in lap joint driving connection with the second arm 422 through the driving flange 313, when the adjustment sleeve 31 rotates reversely, the driving flange 313 and the second arm 422 are separated, and the adjustment sleeve 31 cannot drive the mode switching member 42 to rotate reversely. It is therefore necessary to actuate the mode switching member 42 from the second position to the first position by means of the reset member 43 when the drill 1 is switched from the strike mode to the drill mode.

The adjusting sleeve 31 continues to rotate reversely, and the adjusting nut 32 is driven to move forward linearly in the process of rotating reversely from the second stop position to the first stop position by the adjusting sleeve 31. The further the adjustment nut 32 is moved forward, the smaller the torque threshold defined by the drill 1.

According to the electric drill 1 provided by the application, on the premise that the structure of the electric drill 1 can meet three working modes, the original annular support for switching the working modes is omitted, so that the axial length of the electric drill 1 is reduced by at least one annular support, and the length of the whole electric drill is shortened.

The present application is not limited to the above-described embodiments. Those of ordinary skill in the art will readily appreciate that many alternatives to the dual speed ratchet wrench of the present application exist without departing from the principles and scope of the present application. The protection scope of the present application is subject to the claims.

Claims (10)

1. An electric power tool, characterized in that the electric power tool comprises:

a housing;

an output shaft having a stepped portion on a front side thereof for restricting rearward movement of the output shaft;

a transmission assembly which is accommodated in the housing and drives the output shaft;

the impact assembly comprises a static ratchet wheel and a dynamic ratchet wheel, wherein the static ratchet wheel is fixedly connected in the shell, and the dynamic ratchet wheel is fixedly connected with the output shaft and is arranged opposite to the static ratchet wheel 45;

a mode switching member which is located between the movable ratchet and the stepped portion and rotatably supports the output shaft, the mode switching member being switchable in a front-rear direction to a first position close to the stationary ratchet or a second position away from the stationary ratchet;

an elastic member, one end of which abuts against the mode switching member, and the other end of which abuts against the output shaft;

when the mode switching piece is positioned at a first position, the elastic piece presses the movable ratchet wheel against the mode switching piece through the output shaft so as to separate the movable ratchet wheel from the static ratchet wheel, form an impact length L between the step part and the mode switching piece, compress the output shaft towards the rear, and the static ratchet wheel is meshed with the movable ratchet wheel;

when the mode switching part is positioned at the second position, the output shaft is compressed towards the rear, the static ratchet wheel and the movable ratchet wheel cannot be meshed, the electric tool further comprises a limiting part clamped at the rear side of the output shaft, the elastic part is used for propping the limiting part against the transmission assembly through the output shaft, the impact length X between the step part and the mode switching part is formed, and the impact length X is smaller than the impact length L.

2. The power tool of claim 1, wherein the power tool comprises a power tool,

the mode switching piece rotatably supports the output shaft through a bearing;

the bearing is positioned between the movable ratchet wheel and the step part, the outer ring of the bearing is fixedly connected with the mode switching piece, and the inner ring of the bearing is in clearance fit with the output shaft.

3. The power tool according to claim 2, wherein the elastic member is a conical spring having a front end abutting against the output shaft and a rear end abutting against an inner race of the bearing.

4. The power tool according to claim 2, wherein when the mode switching member is located at the second position, the stepped portion abuts against the front end of the bearing in a state where the impact length X is 0.

5. The power tool of claim 1, wherein the transmission assembly comprises a motor, a planetary gear set, the motor driving the output shaft through the planetary gear set;

the limiting piece is a clamp spring or an O-shaped ring and is propped against the planetary gear set.

6. The power tool of claim 1, further comprising an adjustment sleeve rotatably supported to the housing, the mode switching member being driven to move in the front-rear direction by a transmission guide, the transmission guide comprising:

the guide plate is fixedly connected to the shell, and a guide lug extends towards the mode switching piece;

the guide groove is formed in the shell, and the guide groove and the end face of the guide lug are arranged together to form a guide path;

a first arm formed at the mode switching member and passing through the guide groove, the first arm being driven by the mode switching member to be movable along the guide path;

a second arm, the mode switching member extending toward the adjustment sleeve;

a drive flange, the adjustment sleeve extending toward the mode switch member;

the transmission flange is overlapped with the second arm to transmit the external force received by the adjusting sleeve to the mode switching member so that the mode switching member moves along the guide path.

7. The power tool according to claim 6, wherein a guide slope is further formed between an inner end surface of the guide plate and an inner end surface of the guide projection to form a guide path therebetween;

when the first arm abuts against the inner end face of the guide plate, the mode switching piece is located at a second position;

when the first arm abuts against the inner end face of the guide lug, the mode switching piece is located at a first position.

8. The power tool of claim 7, wherein an inner end surface of the guide projection is formed with a guide rib to abut the first arm.

9. The power tool of claim 6, wherein the mode switching member further comprises a reset member coupled to drive the mode switching member along the guide path from a first position to a second position when the drive flange is decoupled from the second arm.

10. The power tool according to claim 9, wherein the restoring member is a torsion spring, and both ends thereof are respectively formed with connection legs, one of which is fixedly connected with the static ratchet wheel, and the other of which is fixedly connected with the inner wall of the mode switching member.