CN219649813U

CN219649813U - Electric tool

Info

Publication number: CN219649813U
Application number: CN202320585598.XU
Authority: CN
Inventors: 左常伟; 童树彬; 王旭; 陈斌斌
Original assignee: Nanjing Chervon Industry Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2023-09-08
Anticipated expiration: 2033-03-22

Abstract

The utility model discloses an electric tool, comprising: main casing, actuating mechanism, work head and coupling assembling, coupling assembling includes: at least one universal joint to rotate the working head about a first axis relative to the main housing; the universal joint includes: the input part, the output part and the holding part are defined that the maximum radial dimension of the largest part of the radial dimensions of the input part, the output part and the holding part is the maximum radial dimension of the universal joint, and the ratio of the maximum radial dimension of the universal joint to the outer diameter dimension of the motor is more than or equal to 0.1 and less than or equal to 0.9. The connection assembly of the electric tool can ensure strength in the torque transmission process. The compactness of the electric tool as a whole is improved.

Description

Electric tool

Technical Field

The utility model relates to a tool, in particular to a handheld electric tool.

Background

Power tools include hand-held power tools and table-top power tools. Among the hand-held power tools, the hand-held power tools for DIY lovers and home users have higher demands for flexibility of use conditions and compactness of products.

In the related art, rotary hand-held power tools such as screwdrivers and drills generally employ two types of straight or angular profiles to accommodate different usage scenarios. In the case where certain straight and angular orientations must be performed simultaneously, both tools must be at hand for constant alternate use.

Disclosure of Invention

In order to solve the defects in the prior art, the utility model aims to provide a miniaturized and stable-strength electric tool.

In order to achieve the above object, the present utility model adopts the following technical scheme:

a power tool, comprising: a main housing provided with an accommodation space; a driving mechanism at least partially accommodated in the accommodation space; the driving mechanism comprises a motor; the working head comprises an output shaft which rotates around an output axis under the drive of the driving mechanism; a coupling assembly connecting the output shaft and the drive mechanism, the coupling assembly including at least one universal joint to rotate the working head about the first axis relative to the main housing; wherein, the universal joint includes: an input part, an output part and a holding part, wherein the holding part is connected with the input part and the output part; the maximum radial dimension of the input part, the output part and the holding part is defined as the maximum radial dimension of the universal joint, and the ratio of the maximum radial dimension of the universal joint to the outer diameter dimension of the motor is greater than or equal to 0.1 and less than or equal to 0.9.

In some embodiments, the ratio of the maximum radial dimension of the universal joint to the outer diameter dimension of the motor is greater than or equal to 0.1 and less than or equal to 0.7.

In some embodiments, the working head comprises: the working head moves to a limiting position of the limit around the first axis, and when the working head is positioned at the limiting position, an included angle alpha between the axis of the input part and the axis of the output part is less than or equal to 85 degrees.

In some embodiments, the working head further comprises: a first position in which the axis of the input portion is parallel or coincident with the axis of the output portion.

In some embodiments, the limit positions include: the working head moves to a first limit position of limit along a first direction around a first axis and moves to a second limit position of limit along a second direction, and the first limit position and the second limit position are positioned at two sides of the first position.

In some embodiments, the ratio of the output torque of the output shaft when the working head is in the extreme position to the output torque of the output shaft when the working head is in the first position is greater than or equal to 0.5 and less than or equal to 1.

In some embodiments, the output torque of the output shaft is greater than or equal to 2.5n·m when the working head is in the first position.

In some embodiments, the retaining portion comprises a spherical cage and a corresponding spherical cage of balls.

In some embodiments, the drive mechanism includes a direct current power source.

A power tool, comprising: a main housing provided with an accommodation space; a driving mechanism at least partially accommodated in the accommodation space; the driving mechanism comprises a motor; the working head comprises an output shaft which rotates around an output axis under the drive of the driving mechanism; a coupling assembly connecting the output shaft and the drive mechanism, the coupling assembly including at least one universal joint to rotate the working head about the first axis relative to the main housing; wherein, the universal joint includes: the output shaft comprises an input part, an output part and a holding part, wherein the holding part is connected with the input part and the output part, the output part is connected with the output shaft, and the maximum output torque of the output shaft is more than or equal to 2.5 N.m.

According to the electric tool, the connecting component is arranged to enable the working head to rotate around the first axis, and compared with the technical scheme that the driving mechanism and the working head rotate simultaneously, the electric tool is small in rotating part size and is more beneficial to being used in a narrow space. By defining the ratio of the maximum radial dimension of the universal joint to the outer diameter dimension of the motor, the connection assembly can be made strong during torque transfer. The compactness of the whole electric tool is improved, and better using effect is provided.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of the utility model with the working head in an extreme position;

FIG. 2 is a schematic perspective view of an embodiment of the present utility model with the working head in a first position;

FIG. 3 is a schematic illustration of the structure of one embodiment of the present utility model with the working head in the position as in FIGS. 1 and 2, respectively;

FIG. 4 is a cross-sectional view of the power tool of FIG. 3 taken along line A-A;

FIG. 5 is a schematic view of the internal structure of the power tool of FIG. 2, with a gear case housing partially in section;

FIG. 6 is an exploded view of a portion of the structure of a power tool showing primarily the main housing, the output shaft housing, the positioning assembly and the locking assembly in accordance with one embodiment of the present utility model;

fig. 7 is another perspective exploded view of a portion of the structure of a power tool according to one embodiment of the present utility model, showing primarily the main housing, the output shaft housing, the positioning assembly and the locking assembly.

Detailed Description

In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.

In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The utility model is described in detail below with reference to the drawings and the specific embodiments.

For clarity of explanation of the technical solution of the present utility model, upper, lower, left, right, front and rear sides are also defined as shown in fig. 1.

As shown in fig. 1 to 4, the power tool 1 includes a work head 10, a main housing 20, and a drive mechanism 30. The working head 10 can directly output power or be connected with other working accessories to output power, and the electric tool 1 can be a corresponding tool such as a screwdriver, a drill, a wrench and the like according to different working modes of the working head 10 or different output power. The working head 10 is connected to the main housing 20 and the working head 10 rotates relative to the main housing 20 about the first axis 101 under the influence of an external force. The working head 10 is connected to the driving mechanism 30 and outputs power under the action of the driving mechanism 30.

The working head 10 comprises an output shaft 11. The output shaft 11 is driven by the drive mechanism 30 to rotate about the output axis 102. In this embodiment, for example, a screw driver is used as an example, and the end of the output shaft 11 is further formed with a mounting groove 111 for mounting different heads, such as a standard hexagonal groove. In other alternative embodiments, for example where the power tool is a wrench, the output shaft 11 is formed or attached at its end with a mounting head for mounting the sleeve. In other alternative embodiments, such as where the power tool is a drill, the end of the output shaft 11 is connected to a chuck assembly for holding a drill bit.

The main housing 20 includes a grip 22 and a connection portion 21, the connection portion 21 being formed or connected to one end of the grip 22, the connection portion 21 being for connecting the working head 10. In the present embodiment, the main housing 20 extends entirely along the third axis 103. The connection portion 21 is located at an upper end portion of the main housing, that is, the working head 10 is connected to an upper end of the main housing 20. The connection portion 21 is formed with a first accommodation space. The grip portion 22 is disposed below the connection portion. The grip portion 22 is formed with a second accommodation space, and the first accommodation space and the second accommodation space communicate. The driving mechanism 30 is mostly disposed in the second accommodating space formed by the grip portion 22. It will be appreciated that the main housing 20 is generally straight tubular.

As shown in fig. 4 to 5, the driving mechanism 30 includes a motor 32 and a dc power supply 33. In the present embodiment, the motor 32 includes a drive shaft rotatable about a drive axis. In this embodiment, the drive axis coincides with the third axis 103. In other alternative embodiments, the drive axis and the third axis 103 are arranged parallel to each other but not coincident. In other alternative embodiments, the drive axis is disposed at an angle to the third axis 103. In the present embodiment, the motor 32 is specifically an electric motor, and in the following description, the motor 32 will be used instead of the motor, but this is not intended as a limitation of the present utility model.

In the present embodiment, the dc power supply 33 is specifically a battery or a battery pack. The battery or battery pack cooperates with a corresponding power circuit to power the power tool 1. Those skilled in the art will appreciate that the battery is a built-in rechargeable battery or an alternative standard battery. The dc power supply 33 may be a battery pack. In some embodiments, the DC power source 33 comprises a battery. In some embodiments, the dc power source comprises a plurality of batteries. It will be appreciated that the number of cells per cell will vary depending on the nominal voltage and capacity of the cell and these are not limiting on the spirit of the utility model. In this embodiment, the nominal voltage of the dc power supply 33 is less than or equal to 7.2V. In some embodiments, the nominal voltage of the dc power supply is less than or equal to 5V.

In this embodiment, the diameter of the grip portion is substantially uniform. In some embodiments, to increase the charge capacity of the dc power supply 33, and thus the operational life, the dc power supply 33 increases the width of the grip portion 22 at the corresponding position.

The main housing 20 may be provided near the end with a charging port such as one or more of a USB interface, a type-c interface, and a lighting interface. In the present embodiment, the charging port 231 is provided at the bottom. The dc power supply 33 is electrically connected to the charging port 231. In some embodiments, the dc power source 33 is a rechargeable battery that is removable from the grip portion 22. The power tool is not limited to the power supply using the dc power supply 33. The electric tool is matched with corresponding rectifying, filtering and voltage regulating circuits, so that not only can a direct-current power supply be used, but also alternating current can be used for supplying power.

As shown in fig. 1-3 and 6-7, the working head 10 further includes a moving portion 12 and an output shaft housing 13. Wherein the moving part 12 is formed or connected to the output shaft housing 13. The output shaft housing 13 wraps around the outer periphery of the output shaft 11, wherein the output shaft housing 13 does not substantially rotate with the output shaft 11 when the output shaft 11 rotates about the output axis 102.

The moving part 12 is connected to the main casing 20. In the present embodiment, the moving part 12 is movably connected to the connecting part 21 or is disposed in the first accommodating space. When the working head 10 rotates about the first axis 101 with respect to the main housing 20, the moving portion 12 rotates with the working head 10 about the first axis 101. The connection portion 21 of the main housing 20 is provided with a rotation groove 211, the output shaft 11 protrudes from the rotation groove 211, and the movement portion 12 is restricted in the rotation groove 211. Wherein the connection portion 21 comprises a guide portion having an arc shape or a shape similar to the arc shape, along which the working head 10 moves. In some embodiments, the rotation groove 211 may be a closed groove body formed with a space in which the moving part 12 is placed. In some embodiments, the rotating groove 211 may be an open groove, and has a limiting portion for limiting the movement of the moving portion 12, so that the rotating groove 211 forms a limiting groove with an opening in the first accommodating space by providing the limiting portion. The output shaft 11 protrudes from the rotation groove 211, and the outer diameter of the end of the output shaft 11 connected to the moving portion 12 is approximately equal to the width of the rotation groove, so that the end engages with the rotation groove 211. The rotation groove 211 is provided on the circumferential side (i.e., the side around the first axis 101) of the connection portion 21. In the present embodiment, the connecting portion 21 has a curved surface on the peripheral side, and the moving portion 12 has a curved surface corresponding to the shape of the connecting portion on the peripheral side. The surface of the moving part 12 is fitted to the inner surface of the connecting part 21 so that the moving part 12 can move along the rotating groove 211 on the connecting part 21.

As shown in fig. 4 to 5, in the present embodiment, the power tool 1 further includes a connection assembly 50. The working head 10 is rotated about the first axis 101 relative to the main housing 11 by the connection assembly 50. The connection assembly 50 transmits the torque output from the drive mechanism 30 to the output shaft 11. The power tool 1 includes a first transmission path. The first transmission path is the torque transmission path from the drive mechanism 30 through the connection assembly 50 to the output shaft 11. In the present embodiment, after the motor 32 is energized and started, the drive shaft of the motor 32 rotates to generate torque. The drive mechanism 30 transmits torque to the output shaft 11 through the connection assembly 50. The output shaft 11 outputs and acts on the fastener to thereby form a torque transmission path, i.e., a first transmission path, from the drive mechanism 30 through the coupling assembly 50 to the output shaft 11. It will be appreciated that when the working head 10 is rotated about the first axis 101 relative to the main housing 20, the axis P of the first transmission path varies with the rotation of the working head 10, i.e. the rotation of the output shaft 11, i.e. the starting point of the axis P of the first transmission path is the motor 32 and the ending point passes through the output shaft 11. The axis P of the first transmission path is then a curve or straight line from the motor 32 through the coupling assembly 50 to the output shaft 11. The first transmission path direction is a direction from the start point to the end point of the axis P of the first transmission path.

The connection assembly 50 includes: an input portion 50a connected to the drive mechanism 30 and an output portion 50b connected to the output shaft 11. The input portion 50a and the output portion 50b are two independent members connected to each other or are different portions of the same member. When the working head 10 is rotationally moved about the first axis 101 relative to the main housing 20, the components in the first transmission path are allowed to deform or the components in the first transmission path are allowed to displace in the direction of the first transmission path. That is, the set of parts in the first drive path includes at least one component that is a flexible structure, or a floating connection between at least two components in the set of parts in the first drive path. In this way, the axis P of the first transmission path can flex or change angle as the working head 10 rotates about the first axis 101, thereby releasing the axial restraint of the components in the first transmission path. In the present embodiment, the input portion 50a and the output portion 50b are mutually independent members connected to each other. When the working head 10 is rotationally moved about the first axis 101 with respect to the main housing 20, at least one of the drive mechanism 30, the input portion 50a, the output portion 50b, and the output shaft 11 is allowed to be displaced in the first transmission path direction. In some embodiments, the input 50a and output 50b are different parts of the same component, for example this component may be a flexible cable or shaft. The connection assembly 50 is allowed to deform as the working head 10 is rotationally moved about the first axis 101 relative to the main housing 20.

As one embodiment of the present utility model, the connection assembly 50 includes a universal joint 50c. In the present embodiment, the universal joint 50c includes a first universal joint 51 and a second universal joint 52 connected to each other, i.e., the universal joint 50c may be a double universal joint. The first and second universal joints 51, 52 may each provide at least two orthogonal degrees of rotational freedom. The specific structure of the universal joint will be described taking the first universal joint 51 as an example. The first universal joint 51 includes a first input portion 511, a first output portion 513, and a first holding portion 512. The first holding portion 512 connects the first input portion 511 and the first output portion 513. In this embodiment, the first retaining portion 512 is a spherical retainer composed of a spherical seat 5121 and a corresponding spherical head 5122. Either one of the first input portion 511 and the first output portion 513 is formed with or connected to a ball seat 5121, and the other is formed with or connected to a ball head 5122. In the present embodiment, one end of the first input portion 511 is connected to the driving mechanism 30, and the other end of the first input portion 511 is formed with a spherical seat 5121. One end of the first output portion 513 is formed with a ball 5122, and the other end is connected to the second universal joint 52. A ball is provided in the ball 5122 so that the ball 5122 is held in the ball seat 5121 and the first universal joint 51 achieves a variable angle power transmission. The dimension defining the largest portion of the radial dimensions of the first input portion 511, the first output portion 513, and the first holding portion 512 is the largest radial dimension R1 of the first universal joint 51. In the present embodiment, the diameter of the spherical seat 5121 is the maximum radial dimension R1 of the first universal joint 51. The ratio of the maximum radial dimension R1 of the first universal joint 51 to the outer diameter dimension R2 of the motor 32 is greater than or equal to 0.1 and less than or equal to 0.9. It should be noted that when the motor 32 is an inner rotor motor, the outer diameter of the motor 32 is the diameter of the stator laminations. When the motor 32 is an external rotor motor, the outer diameter of the motor 32 is the diameter of the rotor sleeve. In some embodiments, the ratio of the maximum radial dimension R1 of the first universal joint 51 to the outer diameter dimension R2 of the motor 32 is greater than or equal to 0.1 and less than or equal to 0.7. In some embodiments, the ratio of the maximum radial dimension R1 of the first universal joint 51 to the outer diameter dimension R2 of the motor 32 is greater than or equal to 0.1 and less than or equal to 0.6. In some embodiments, the ratio of the maximum radial dimension R1 of the first universal joint 51 to the outer diameter dimension R2 of the motor 32 is greater than or equal to 0.2 and less than or equal to 0.9.

As known in the related art, the outer diameter of the motor affects the performance of the motor. In the first transmission path, the connection assembly 50 needs to ensure sufficient strength so that torque can be transmitted to the output shaft 11. Without breaking or unintended deformation of the connection assembly during torque transfer. If the diameter or volume of the connection assembly 50 increases, the strength of the connection assembly is increased, but the use feeling of the product, the beauty of the product, and the cost of the product are also reduced. A relative balance and proper relationship between the connection assembly 50 and the motor 32 is required. The ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the motor 32 is defined to be greater than or equal to 0.1 and less than or equal to 0.9. In some embodiments, a ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the motor 32 is defined to be greater than or equal to 0.1 and less than or equal to 0.7. In some embodiments, a ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the motor 32 is defined to be greater than or equal to 0.2 and less than or equal to 0.7 so that the connection assembly 50 can secure strength during torque transfer. The compactness of the whole electric tool is improved, and better using effect is provided.

In some alternative embodiments, the connection assembly does not limit the number of universal joints involved. The number of the universal joints may be one or two or more, and this does not limit the essential content of the present utility model.

In some alternative embodiments, the first universal joint 51 is a cross-over universal joint. The first holding portion is a cross portion connecting the first input portion and the first output portion. The diameter of the first retaining portion is the diameter of the smallest circle that encloses the cross-shaft portion.

In the present embodiment, the first universal joint 51 and the second universal joint 52 are spherical universal joints having the same structure. In some embodiments, the first universal joint and the second universal joint may be of the same structure and different sizes. In some embodiments, the first universal joint and the second universal joint may be different structures of different sizes. It will be appreciated that when the universal joint 50c includes two or more individual universal joint pieces, the maximum radial dimension R1 of the universal joint 50c is the largest value in the radial dimensions of the input, output and holding portions of each individual universal joint piece in the universal joint 50c.

In this embodiment, the connection assembly 50 further includes an intermediate piece 53. The intermediate piece 53 is used for displaying logo or special shaping of the product or for displaying the shape of the product, or may be used for displaying product information, such as indicating the rotation angle of the working head 10 about the first axis 101, indicating the rotation speed of the output shaft 11. In some embodiments, the middleware 53 is provided with a status display unit, where the status display unit includes a liquid crystal display/Light-Emitting Diode (LCD/LED) display screen, a buzzer, a Light-Emitting Diode component, or other components with a prompt function, which is used for displaying or prompting a status when the electric tool is in an abnormal working state or has low electric quantity. The specific prompting mode is different according to different product definitions and requirements. It will be appreciated that specific hinting means are well known to those skilled in the art. It will be appreciated that the intermediate piece is not a component of the universal joint 50c and that its dimensions are not the dimensions of the universal joint 50c.

As shown in fig. 1-3, the working head 10 includes a limit position, which is a position where the working head 10 moves to a limit about the first axis 101, and a first position, which is a position where the axis of the input portion 50a is parallel or coincident with the axis of the output portion 50b. In the present embodiment, the axis of the input portion 50a coincides with the drive axis of the motor 32 and the third axis 103. The axis of the output portion 50b coincides with the output axis 102 of the output shaft 11. As shown in fig. 2, when the working head 10 is in the first position, the third axis 103 coincides with the output axis 102. The angle α between the third axis 103, which is the axis of the input portion 50a, and the output axis 102, which is the axis of the output portion 50b, is 0 °. As shown in fig. 1, when the working head 10 is in the extreme position, the angle α between the axis of the input portion 50a, i.e., the third axis 103, and the axis of the output portion 50b, i.e., the output axis 102, is less than or equal to 85 °. In some embodiments, α is less than or equal to 70 °, 60 °, or 50 ° when the working head 10 is in the extreme position. By limiting the angle alpha between the axis of the input part 50a, i.e. the third axis 103, and the axis of the output part 50b, i.e. the output axis 102, in the limit position, the output torque of the output shaft 11 is ensured, and the torque transmission efficiency of the connecting assembly is ensured. When the working head 10 is in the first position, the torque transfer efficiency of the connection assembly 50 is highest. When the working head 10 is in the extreme position, the torque transfer efficiency of the connection assembly 50 is lower than that in the first position. In this embodiment, in the limit position, the angle α between the axis of the input portion 50a, i.e. the third axis 103, and the axis of the output portion 50b, i.e. the output axis 102, is less than or equal to 85 °, so that the ratio of the output torque of the output shaft 11 when the working head 10 is in the limit position to the output torque of the output shaft 11 when the working head 10 is in the first position is greater than or equal to 0.5 and less than or equal to 1, and the torque transmission efficiency of the connection assembly is ensured. In some embodiments, the ratio of the output torque of the output shaft 11 when the working head 10 is in the extreme position to the output torque of the output shaft 11 when the working head 10 is in the first position is greater than or equal to 0.6 and less than or equal to 1. In the present embodiment, when the working head 10 is located at the first position, the output torque of the output shaft 11 is greater than or equal to 2.5n·m.

In the present embodiment, the limit positions include: the working head 10 moves in a first direction about a first axis 101 to a first extreme position of limitation. Also included between the first position and the first limit position are a plurality of positions for locking the working head 10. As shown in fig. 6-7, the power tool 1 further includes a positioning assembly 40. The positioning assembly 40 is used to position the rotational position of the working head 10 about the first axis 101 relative to the main housing 20. The positioning assembly 40 is provided between the moving portion 12 and the connecting portion 21, and couples the moving portion 12 and the connecting portion 21 to stop the working head 10 at the set position.

The positioning assembly 40 includes a base 41, a positioning member 42, and a positioning slot 43. The positioning groove 43 is provided in plurality. A plurality of positioning grooves 43 are provided inside the connecting portion 21. In the present embodiment, the outside of the connection portion 21, i.e., the side that can be observed by the user, is provided with a plurality of angle indicators 213. The number of angle indicators 213 is the same as the number of detents 43. The base 41 is provided on the work head 10. In the present embodiment, the base 41 is provided on the output shaft housing 13. The base 41 extends in the direction of the first axis 101. The positioning member 42 connects the moving portion 12 and the connecting portion 21. Wherein, locating piece 42 one end is connected base 41, and the other end can the separation and reusability connect constant head tank 43. The positioning member 42 is movable in the base 41 with respect to the moving portion 12. The movement of the positioning member 42 is caused by the rotation of the working head 10 in the direction about the first axis 101, and the number of positioning grooves 43 corresponds in shape to the positioning member 42. When the positioning groove 43 is connected with the positioning piece 42, positioning of the working head 10 is completed. Wherein each positioning slot 43 corresponds to a different rotation angle of the working head 10.

When the working head 10 rotates from a certain angle to another angle, the positioning piece 42 moves into the mounting seat 43 from a certain positioning groove 43, and then moves into another positioning groove 43 from the mounting seat 43. In this embodiment, the positioning member 42 includes a ball 421 and a telescoping member 422. When the working head 10 is turned, the ball 421 moves in the groove of the adjacent positioning groove 43 until the groove wall is pressed by the groove wall, and the ball 421 biases the telescopic member 422. When the ball 421 enters one of the positioning grooves 43, the expansion piece 422 supports the ball 421 so that the ball 421 is held in the positioning groove 43.

As shown in fig. 4 to 6, the power tool 1 further includes a locking assembly 60, the locking assembly 60 being configured to lock the rotational position of the working head 10 relative to the main housing 20 about the first axis 101. It will be appreciated that the restraining force provided by the positioning assembly 40 is insufficient to ensure that the working head 10 and the main housing 20 do not move relatively during operation, that is, the positioning assembly 40 can restrain the working head 10 and the main housing 20 from moving relatively when positioning is completed, but the positioning state of the positioning assembly 40 is easily damaged when torque output is performed. And the locking assembly 60 may provide a locking force sufficient to maintain the working head 10 and the main housing 20 stably in a relatively locked state during operation.

The locking assembly 60 includes a first tooth 61, a second tooth 62, and a trigger 63. Wherein the first tooth 61 and the second tooth 62 intermesh. The first teeth 61 are formed around the circumference of the working head 10. In the present embodiment, the first teeth 61 are provided on the output shaft housing 13 and on the outer periphery of the first through hole 131. The trigger 63 is partially disposed outside the main housing 20 for triggering by a user. The trigger 63 is connected to the second tooth 62. The trigger 63 comprises a locked position and an unlocked position, wherein the first tooth 61 and the second tooth 62 are engaged with each other when the trigger 63 is in the locked position. When the trigger 63 is triggered to move to the unlocked position, the second tooth 62 is displaced to disengage from the first tooth 61, at which time the working head 10 is rotatable about the first axis 101 relative to the main housing 20. The trigger 63 is provided on the same side as the torque adjuster 173 and the switching operation. The trigger 63 is located in the upper position of the grip. Wherein the trigger 63 is provided at a position where a thumb can be operated when the user grasps the grip portion with his hand.

In this embodiment, the locking assembly 60 further includes a biasing element 64 coupled to the trigger 63. The biasing element 64 provides a biasing force that moves the trigger 63 from the unlocked position to the locked position, i.e., a biasing force that moves the second tooth 62 toward the first tooth 61. It will be appreciated that the number of detents 43 in the positioning assembly 40 corresponds to the first teeth 61.

In some embodiments, the limit positions include: the working head 10 moves about the first axis 101 and in a second direction to a second extreme position of limitation. The first limit position and the second limit position are positioned at two sides of the first position. The first position is an intermediate position, the first limit position is in front of the first position, and the second limit position is behind the first position. The second limit position and the first limit position may be symmetrically arranged relative to the first position, or the second limit position may be closer to the first position relative to the first limit position.

As shown in fig. 4-5, the drive mechanism 30 also includes a transmission assembly 31. Wherein the speed changing assembly 31, the motor 32 and the direct current power supply 33 are sequentially connected from top to bottom. In the present embodiment, the speed changing assembly 31, the motor 32, and the dc power supply 33 are disposed in the second accommodation space or at least mostly disposed in the second accommodation space.

The speed change assembly 31 is used to transmit the power output from the motor 32 to the output shaft 11. The transmission assembly 31 is disposed between the output shaft 11 and the motor 32, and the transmission assembly 31 is disposed at least partially or entirely in the grip portion 22, or may be disposed at least partially in the connection portion 21. In the present embodiment, the transmission mechanism 31 employs a planetary gear reduction mechanism. The transmission mechanism 31 includes a planetary gear set 311 and a gear case 312 of three or more stages. An internal tooth structure is provided inside the gear case housing 312. Since the principle of operation of a planetary gear reduction mechanism and the principle of speed reduction by such a transmission mechanism or the principle of planetary gear speed regulation are well known to those skilled in the art, a detailed description is omitted herein for the sake of brevity.

As shown in fig. 3-4, the distance from the rear end of the main housing to the front end of the output shaft is defined as the maximum distance L when the working head 10 is in the first position. The distance from the first axis 101 to the front end of the output shaft 11 is L1. It should be explained that, in the present embodiment, the clamping portion for clamping the accessory is formed on the shaft body of the output shaft, and the front end of the output shaft is the front end of the shaft body. In some embodiments, the output shaft includes a shaft body and a clamping portion fixedly connected to the shaft body, and the front end of the output shaft is a forward-most portion of the shaft body and the clamping portion. In some embodiments, the output shaft includes a shaft body and a clamping portion, the clamping portion is detachably connected to the shaft body, that is, when the electric tool is still capable of driving the accessory to work after the clamping portion is detached, the front end of the output shaft is the front end of the shaft body. In the present embodiment, the ratio of the distance L1 from the first axis 101 to the front end of the output shaft 11 to the maximum distance L is greater than or equal to 0.1 and less than or equal to 0.4. In some embodiments, the ratio of the distance L1 from the first axis to the front end of the output shaft to the maximum distance L is greater than or equal to 0.1 and less than or equal to 0.35. In some embodiments, the ratio of the distance L1 from the first axis to the front end of the output shaft to the maximum distance L is greater than or equal to 0.1 and less than or equal to 0.3 to make the working head more suitable for small spaces. In this embodiment, the distance L1 from the first axis to the front end of the output shaft is less than or equal to 65mm. In some embodiments, the distance L1 from the first axis to the front end of the output shaft is less than or equal to 60mm. In some embodiments, the distance L1 from the first axis to the front end of the output shaft is less than or equal to 55mm. In some embodiments, the distance L1 from the first axis to the front end of the output shaft is less than or equal to 50mm.

In some embodiments, the distance L3 of the first axis 101 to the rear end of the main housing is less than or equal to 230mm. In some embodiments, the distance L3 of the first axis 101 to the rear end of the main housing is less than or equal to 210mm. In some embodiments, the distance L3 of the first axis 101 to the rear end of the main housing is less than or equal to 195mm.

In the present embodiment, the direct current power supply 33 is built in the main housing. When the working head 10 is in the first position, the ratio of the length L2 of the dc power supply 33 to the maximum distance L from the rear end of the main housing to the front end of the output shaft is greater than or equal to 0.1 and less than or equal to 0.6. In some embodiments, when the working head 10 is in the first position, the ratio of the length L2 of the dc power source 33 to the maximum distance L from the rear end of the main housing to the front end of the output shaft is greater than or equal to 0.1 and less than or equal to 0.5. In some embodiments, when the working head 10 is in the first position, the ratio of the length L2 of the dc power source 33 to the maximum distance L from the rear end of the main housing to the front end of the output shaft is greater than or equal to 0.1 and less than or equal to 0.4, so as to make the electric tool compact. The length L2 of the dc power supply 33 is the length of the battery or battery pack of the dc power supply 33 in the direction of the third axis 103. In this embodiment, the weight of the power tool is 400g or less. In some embodiments, the dc power source 33 is a battery pack that is removably mounted in the main housing, and the dc power source 33 is partially mounted in the main housing. At this time, the length L2 of the dc power supply 33 is the length of the battery pack.

As shown in fig. 1 to 3 and fig. 6 to 7, the main housing 20 is provided with a window 14, and the window 14 is used for displaying the internal structure of the power tool 1. In the present embodiment, the window 14 is provided at the connection portion 21, and the position of the window 14 is opposite to the position of the connection assembly 50, so that a part of the structure of the connection assembly 50 is displayed in the window.

As shown in fig. 1-3, the power tool 1 further includes at least two switch assemblies and a controller that control different functions of the motor. The switch assembly includes an operating member and a corresponding switching element. The operating elements include a main switch operating element 171, a torque adjuster operating element 173, and a switching operating element. The main switch operating member 171 corresponds to a main switch for controlling the start and stop of the motor 32. The torque control operation member 173 and the switching operation member control the output torque of the output shaft 11 and the forward and reverse rotation states of the switching motor 32 by sending different signals to the controller. The main switch operating element 171 is provided at the junction between the grip portion 22 and the connecting portion 21. In the present embodiment, the main switch operating member 171 is provided on the side adjacent to the window portion 14. The switching operation member is coupled to the main switch operation member 171. The torque adjuster operating member 173 is provided on the grip portion 22. In some embodiments, the knob operation member 173 is disposed near the lower end portion of the grip 22. The torque adjuster 173 is provided on the same side as the window 14. That is, the main switch operating piece 171 and the knob operating piece 173 are disposed on the adjacent sides. It will be appreciated that the main switch operating member 171 is angularly offset from the torque adjuster operating member 173 on the main housing 20 about the third axis 103. In the present embodiment, a torsion indicator light 1721 is provided near the knob operation member 173. Different output torques are characterized by different display states of torque indicator 1721. The torsion indicator 1721 is disposed on the same side of the grip 22 as the torque adjuster 173. In other alternative embodiments, the switching operation member is provided separately from the main switch operation member 171, wherein the switching operation member is provided on the same side of the grip portion 22 as the main switch operation member 171.

In the present embodiment, the torque control operation member 173 is combined with a locking function or a locking member is provided in the vicinity of the torque control operation member 173. Namely, the connection and disconnection of the electric connection between the motor and the direct current power supply can be controlled through the locking piece.

The controller is disposed on the control circuit board 16. The control circuit board 16 includes: a PCB circuit board (Printed Circuit Board) and an FPC circuit board (Flexible Printed Circuit board). The controller adopts a special control chip, such as a singlechip and a micro control module MCU (Microcontroller Unit).

The operating member is connected with the corresponding switch. The switch is electrically connected with the controller. The controller makes corresponding control actions to the motor through different signals sent by the switch.

The control circuit board 16 is electrically connected to the driving mechanism 30, and the control circuit board 16 is disposed in the holding portion 22 and is parallel or substantially parallel to the driving mechanism 30 or the third axis 103, where substantially parallel refers to a case where an angle between the control circuit board 16 and the driving mechanism 30 or the third axis 103 is less than or equal to 10 °.

As shown in fig. 2, the power tool 1 further includes a lighting assembly 15. An illumination assembly 15 is provided on the work head 10 and provides illumination light illuminating the work area. The illumination assembly 15 rotates with the working head 10 about the first axis 101, always providing illumination light illuminating the working position of the output shaft 11. The lighting assembly 15 includes a lighting element for emitting light, which is disposed within the output shaft housing 13 and on one side of the output shaft 11. In other alternative embodiments, the illumination element is disposed around the output shaft.

As shown in fig. 4 to 7, in the present embodiment, the connection portion 21 includes a left connection portion 214 and a right connection portion 215 that are assembled with each other. Wherein, the right connecting portion 215 is integrally formed with the grip portion 22. That is, the substantially cylindrical grip portion 22 is integrally formed with the right connecting portion 215. The left connecting portion 214 is detachably connected to the right connecting portion 215 so that the strength of the main housing 20 is improved. The bottom of the main housing 20 further includes a lower cover 23, and the lower cover 23 is coupled to a lower end opening of the right coupling portion 215. The charging port 231 is provided on the lower cover 23.

For the user to hold more comfortably, the outer peripheral portion of the main housing is coated with a soft material such as rubber, silicone, soft plastic. In this embodiment, the soft material is disposed near the grip and the working head.

The foregoing has shown and described the basic principles, principal features and advantages of the utility model. It will be appreciated by persons skilled in the art that the above embodiments are not intended to limit the utility model in any way, and that all technical solutions obtained by means of equivalent substitutions or equivalent transformations fall within the scope of the utility model.

Claims

1. A power tool, comprising:

a main housing provided with an accommodation space;

a driving mechanism at least partially accommodated in the accommodation space; the driving mechanism comprises a motor;

the working head comprises an output shaft which is driven by the driving mechanism to rotate around an output axis;

a coupling assembly connecting the output shaft and the drive mechanism, the coupling assembly including at least one universal joint to rotate the working head about a first axis relative to the main housing;

wherein, the universal joint includes: an input portion, an output portion, and a holding portion, the holding portion connecting the input portion and the output portion; the maximum radial dimension of the input portion, the output portion, and the holding portion is defined as the maximum radial dimension of the universal joint, and the ratio of the maximum radial dimension of the universal joint to the outer diameter dimension of the motor is greater than or equal to 0.1 and less than or equal to 0.9.

2. The power tool of claim 1, wherein a ratio of a maximum radial dimension of the universal joint to an outer diameter dimension of the motor is greater than or equal to 0.1 and less than or equal to 0.7.

3. The power tool of claim 1, wherein the working head comprises: when the working head is positioned at the limit position, an included angle alpha between the axis of the input part and the axis of the output part is less than or equal to 85 degrees.

4. The power tool of claim 3, wherein the working head further comprises: a first position in which the axis of the input portion is parallel or coincident with the axis of the output portion.

5. The power tool of claim 4, wherein the limit position comprises: the working head moves to a first limit position of limit around a first axis along a first direction and moves to a second limit position of limit around the first axis along a second direction, and the first limit position and the second limit position are positioned on two sides of the first position.

6. The power tool according to claim 4, wherein a ratio of the output torque of the output shaft when the working head is in the limit position to the output torque of the output shaft when the working head is in the first position is greater than or equal to 0.5 and less than or equal to 1.

7. The power tool of claim 6, wherein the output torque of the output shaft is greater than or equal to 2.5N-m when the working head is in the first position.

8. The power tool of claim 1, wherein the retainer comprises a spherical cage and a corresponding spherical head.

9. The power tool of claim 1, wherein the drive mechanism comprises a dc power source.

10. A power tool, comprising:

a main housing provided with an accommodation space;

wherein, the universal joint includes: the output device comprises an input part, an output part and a holding part, wherein the holding part is connected with the input part and the output part, the output part is connected with the output shaft, and the maximum output torque of the output shaft is more than or equal to 2.5 N.m.