CN218170270U - Electric tool - Google Patents

Abstract

A power tool (100) comprising: a tool housing (110); a tool holder (120) attached to a front end of the tool housing (110) and adapted to mount a tool; a drive motor (22) housed inside the tool housing (110); and a transmission mechanism (30) housed inside the tool housing (110) for transmitting the power of the drive motor (22) to the cutter, the power tool (100) further comprising a damping chamber and a damping medium housed in the damping chamber and freely movable in the damping chamber, wherein the damping medium comprises a solid medium and/or a liquid medium, the damping chamber being formed on at least one of: the tool housing (110), an additional member attached to the inside or outside of the tool housing and remaining stationary relative to the tool housing (110) during operation of the power tool.

Description

Electric tool

Technical Field

The present invention relates to an electric tool, for example a hand-held electric tool, in particular a hand-held electric tool that outputs a percussion motion and/or a rotary motion, such as a hammer, a drill or a hammer drill.

Background

Hand-held power tools, particularly hammers, drills or hammer drills for drilling or chiseling hard workpieces such as stone, concrete or the like, can vibrate during operation, for example due to the interaction between the tool and the workpiece, due to the operation of a drive motor in the power tool, due to the reciprocating linear movement of a piston, striker or the like in the power tool, or due to the rotation of gears or the like in the power tool. The vibrations are transmitted to the hand of the operator through the tool housing of the electric tool, causing discomfort and even injury to the operator.

Solutions developed to mitigate this vibration are mostly aimed at vibrating in a certain direction or directions, or vibrating at a certain frequency or frequencies. The structures used are often relatively complex, at the expense of increasing the volume and/or weight of the power tool.

SUMMERY OF THE UTILITY MODEL

The utility model aims at reducing the vibration generated when the electric tool is operated.

This object is achieved by a power tool. The electric tool of the present application includes: a tool housing; a tool holder attached to the front end of the tool housing and adapted to mount a tool; a drive motor housed within the tool housing; a transmission mechanism housed inside the tool housing for transmitting power of the drive motor to the cutter, wherein the electric tool further comprises a damping chamber and a damping medium housed in the damping chamber and freely movable in the damping chamber, wherein the damping medium comprises a solid medium and/or a liquid medium, and the damping chamber is formed on at least one of: the tool housing, an additional member attached to an interior or exterior of the tool housing and held stationary relative to the tool housing during operation of the power tool.

In one embodiment, the solid media comprises one or more of: spherical solid or hollow bodies, ellipsoidal solid or hollow bodies, polyhedral solid or hollow bodies, and cylindrical solid or hollow bodies; and/or the liquid medium is water or oil.

In one embodiment, the solid media comprises a steel ball cluster.

In one embodiment, the filling rate of the damping medium in the damping chamber is 50-80%; and/or the largest outer dimension of the solid medium is no greater than 5mm.

In one embodiment, the power tool defines one or more vibration dampening chambers extending along a longitudinal axis along which the cutters are inserted into the cutter head, and the vibration dampening chambers include one or more vibration dampening chambers arranged symmetrically with respect to a longitudinal plane passing through the longitudinal axis.

In one embodiment, the damping chamber comprises one or more housing damping chambers and/or one or more additional damping chambers, wherein: said tool housing including a motor housing portion housing said drive motor and a main housing portion housing said transmission mechanism, each of said one or more housing dampening chambers being provided by one or both of said motor housing portion and main housing portion; and the one or more additional damping chambers are provided by one or more additional members attached within a void space inside the tool housing or attached outside the tool housing and stationary during operation of the power tool.

In one embodiment, the transmission mechanism includes an impact transmission assembly for converting rotary motion output by a drive motor into reciprocating linear motion of the cutter along a longitudinal axis, the impact transmission assembly including a wobble bearing driven by the output shaft of the drive motor, at least one of the one or more additional members being disposed in a spatial region adjacent the wobble bearing within the tool housing.

In one embodiment, the transmission mechanism includes a rotary transmission assembly for transmitting the rotary motion output by the drive motor to the tool to rotate the tool.

In one embodiment, the power tool is a hand-held power tool.

In one embodiment, the power tool is a hammer or a hammer drill.

The utility model discloses an electric tool is through setting up the damping cavity on the part of rigid and provide the damping medium that can freely remove in the damping cavity, has realized the purpose of the vibration energy that produces when absorbing the electric tool operation. The vibration damping medium can freely move in the vibration damping chamber when the electric tool is operated, and the medium can collide with each other when being in a solid form, so that vibration energy can be absorbed, vibration transmitted to the hand of an operator is reduced, and the comfort of the operator is improved. The utility model provides a simple structure, easy realization and with low costs.

Drawings

Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It is to be understood that the embodiments described below are merely illustrative of the principles of the present application and are not intended to limit the scope of the present application.

Fig. 1 schematically shows an exploded view of an electric tool according to an exemplary embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. It will be appreciated by persons skilled in the art that the present invention is not limited to this exemplary embodiment, and that the drawings are not necessarily drawn to scale.

Fig. 1 shows an exemplary power tool 100, a hammer drill, to which the present application can be applied, and the principle of the present application will be described in detail below by taking a hammer drill that outputs both impact motion and rotational motion as an example.

The illustrated power tool 100 includes a tool housing 110 and a tool holder 120 mounted to a front end of the tool housing 110, and a tool (not shown) for performing an operation on a workpiece is attached to the tool holder 120. In this application, "front end" refers to the end near the tool and the workpiece to be machined, and "rear end" refers to the end of the motorized tool 100 that is held by the operator's hand, as opposed to the front end. The front end and the rear end are opposite ends on the longitudinal axis L. The tool is inserted into the tool holder 120 along the longitudinal axis L.

A drive motor 22 for providing a driving force and a transmission mechanism 30 for transmitting the power of the drive motor 22 to the cutter are accommodated in the tool housing 110. Specifically, as illustrated, the tool housing 110 includes a main housing portion 10 and a motor housing portion 20, which may be separately formed and then attached or assembled together to define an interior space in communication with each other. The motor housing portion 20 and the tool rack 120 are attached to the rear end and the front end of the main housing portion 10, respectively, and house the drive motor 22 and the transmission mechanism 30, respectively, as described above.

In the hammer-drill embodiment of fig. 1, the tool of the power tool 100 is capable of outputting percussive and/or rotary motion to perform a hammer and/or drill operation on a workpiece. Accordingly, the transmission mechanism 30 of the power tool 100 includes an impact transmission assembly 310 for converting the rotational motion of the drive motor 22 into a reciprocating linear motion along the longitudinal axis L and transmitting the reciprocating linear motion to the cutter of the power tool 100, and a rotation transmission assembly 320 for transmitting the rotational motion of the drive motor 22 to the cutter of the power tool 100 to rotate the cutter.

Specifically, in the illustrated embodiment, the impact transmission assembly 310 may include a wobble bearing 312, a piston 314, an impact member 316, and a striker pin 318. The wobble bearing 312 is relatively rotatably mounted on the output shaft of the drive motor 22 or an intermediate shaft driven thereby and engages the piston 314 to convert the rotary motion output by the drive motor 22 into reciprocating linear motion of the piston 314 along the longitudinal axis L. An impact member 316 is partially received within the chamber 315 of the piston 314 and is capable of reciprocating along the longitudinal axis L also under the influence of air pressure within the chamber 315 as the piston 314 is driven by the wobble bearing 312. The impact member 316, for example, mechanically engages and drives a striker 318, which striker 318 in turn drives a tool inserted into the internal bore 122 of the tool holder 120, whereby a reciprocating motion along the longitudinal axis L is ultimately transmitted to the tool, which performs an impact motion or hammer operation. The rotary transmission assembly 320 basically includes a hammer tube 322 and a gear reduction mechanism (not shown) coupled between the drive motor 22 and the hammer tube 322 to transmit rotary motion and change rotational speed, such that the hammer tube 322 is rotatable independently of the piston 314, the impact member 316 and the striker pin 318 of the impact transmission assembly 310 disposed therein. The hammer tube 322 drives the tool holder 120 and the tool to rotate together to perform a drilling operation on the tool. The illustration is merely an exemplary transmission 30, and the transmission 30 is not a focus of the present application and will not be described in detail herein.

As shown, the main housing portion 10 of the tool housing 110 is formed with an internal cavity 40, the internal cavity 40 containing a freely movable cluster of steel balls 42. During operation of the power tool 100, the drive motor 22 rotates, the piston 314, the impact member 316, and the striker pin 318 of the impact transmission assembly 310 reciprocate axially, the hammer tube 322 of the rotary transmission assembly 320 and the gears of the gear reduction mechanism rotate, and the tool applies chiseling and/or drilling operations to a workpiece, the movement of these moving parts causing vibration of the power tool 100. At this point, the clusters of steel balls 42 are free to move or bounce (in either direction) within the interior cavity 40 and collide with one another, which can dissipate a significant portion of the vibrational energy, thereby greatly reducing the vibrational energy that is ultimately transmitted to the operator's hand. This is beneficial to reducing vibration on the hands of the operator and improving comfort.

That is, by providing the vibration reduction chamber (the inner cavity 40) on the main housing portion 10 that is stationary with respect to the moving members (the impact member and the rotary member) of the transmission mechanism 30 (the impact transmission assembly 310 and the rotary transmission assembly 320) and providing the vibration reduction medium (the steel ball 42 cluster) that can freely move in the vibration reduction chamber, the vibration of the electric power tool 100 can be reduced to a large extent.

In accordance with this principle, it is understood that the steel balls may be replaced by solid media of other materials, either solid or hollow, such as other metals or other dense non-metallic rigid hard materials. The solid medium is at least smaller in size than the internal cavity to ensure that the solid medium is free to move within the vibration cavity when the power tool 100 vibrates. Similar to steel balls, the solid media may include any other type of solid or hollow body that enables the vibrational energy generated when the power tool 100 is operated to be partially dissipated by collisions between the solid media. The solid medium is not limited to the illustrated spherical shape, and in the case where the above-described function can be achieved, the present application does not limit the shape of the solid medium, such as an ellipsoidal shape, a spherical shape, a polyhedral shape, a cylindrical shape, and the like. The shape, size, number, etc. of the individual solid media may be different from each other, or only one shape, one size of solid media may be provided as shown in the figure. Preferably, the filling rate of the damping medium in the damping chamber is 50-80% to ensure free movement of the damping medium within the damping chamber. Further, it is preferred that the maximum outer dimension of the solid medium, e.g. the outer diameter of the sphere, is not more than 5mm.

It is also conceivable that the damping medium in the damping chamber may be a liquid medium which is able to flow freely in the damping chamber, or a combination of the above-mentioned solid and liquid media. The liquid medium may be water, low viscosity oil, or the like. The use of a liquid medium or a combination of a liquid medium and a solid medium produces less noise than the use of a solid medium alone.

In the illustrated embodiment, an internal cavity 40 is provided in the main housing portion 10, and an opening to the interior of the internal cavity for filling or removing damping medium may be directed toward the motor housing portion 20 as illustrated, alternatively, the opening may be directed in any other direction, for example, the opening may be formed on the outer surface 12 or the inner surface 14. An additional cover and/or sealing element for the liquid damping medium (e.g., a sealing O-ring) may be provided to block or seal the opening, or the opening may be blocked or sealed by a mating component (motor housing portion 20 as shown).

Although only one lumen 40 is shown in the illustrated embodiment, one skilled in the art will appreciate that the size, shape, number, etc. of the lumens may be varied as desired.

As illustrated, the internal cavity 40 (housing damping chamber) provided on the tool housing 110 of the power tool 100 may be an annular chamber extending around the longitudinal axis L. Alternatively or additionally, the motor housing portion 20 also includes an annular chamber extending (e.g., toward the main housing portion 10) about the longitudinal axis L. Alternatively, the inner cavity 40 may not be annular in shape extending about the longitudinal axis L, but rather include two or more damping chambers spaced about the longitudinal axis L or symmetrically disposed about the longitudinal axis L. Preferably, the inner cavity 40 may be two or more damping chambers arranged symmetrically (e.g., arranged at the top and bottom, and/or on both sides with respect to the longitudinal plane P) with respect to the longitudinal plane P passing through the longitudinal axis L. This symmetrical arrangement helps to improve the comfort of the operator holding and operating the power tool and the balance and accuracy of operation of the power tool 100.

In addition to or in lieu of the internal cavity 40 provided in the main housing portion 10 of the tool housing 110, a vibration dampening chamber may be provided in the motor housing portion 20 of the tool housing 110, or in any other stationary (immovable during operation of the power tool) component located within the power tool 100, which may include any non-moving parts housed within the tool housing 110, or additional vibration dampening components provided separately to provide vibration dampening functionality. The additional vibration reduction member may be disposed outside the tool housing 110, e.g., attached to the outer surface 12 of the tool housing 110, or disposed inside the tool housing 110, e.g., in a spatial region a near the wobble bearing 312, such as attached to the inner surface 14 of the tool housing 110 in the spatial region a. Likewise, the additional damping chamber provided by the additional damping member may also be an annular damping chamber, or two or more damping chambers arranged spaced apart around the longitudinal axis L or symmetrically arranged about the longitudinal axis L. Preferably, the additional damping chamber may comprise two or more damping chambers arranged symmetrically with respect to the longitudinal plane P.

In summary, by providing a vibration damping chamber on a non-moving part of the power tool and providing a freely movable vibration damping medium in the vibration damping chamber, vibrations of any vibration direction and any vibration frequency generated during operation of the power tool can be effectively reduced. For liquid media or small-size solid media (such as the illustrated steel ball clusters), the size of the damping chamber does not need to be large, and the damping chamber is convenient to arrange. The damping chamber may be disposed within the tool housing of the power tool, or may be disposed in any void space within the tool housing (e.g., region a described above). The change of the external dimension of the electric tool is little or not required. Therefore, the structure is simple, the implementation is easy, and the cost is low. Advantageously, the additional damping member added in any void space within the tool housing may be removable so as to be able to be selectively added or deployed as the case may be.

Although the foregoing has been described with reference to a hammer drill capable of performing hammer and/or drill operations on a workpiece, it should be apparent that the principles of the present invention are equally applicable to drill tools that output only rotary motion (or drill operations), hammer tools that output only percussive motion (or hammer operations), and any other hand-held power tools that generate vibrations during operation.

The present invention has been described in detail above with reference to exemplary embodiments. It is clear that the embodiments described above and shown in the drawings are exemplary and should not be construed as limiting the invention. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention, and such changes and modifications may be made without departing from the scope of the invention.

Claims (10)

1. A power tool (100) comprising: a tool housing (110); a tool holder (120) attached to a front end of the tool housing (110) and adapted to mount a tool; a drive motor (22) housed inside the tool housing (110); a transmission mechanism (30) accommodated inside the tool case (110) for transmitting the power of the driving motor (22) to the cutter,

characterized in that the power tool (100) further comprises a damping chamber and a damping medium housed in the damping chamber and freely movable in the damping chamber, wherein the damping medium comprises a solid medium and/or a liquid medium, and the damping chamber is formed on at least one of: the tool housing (110), an additional member attached to the inside or outside of the tool housing and remaining stationary relative to the tool housing (110) during operation of the power tool.

2. The power tool (100) of claim 1, wherein the solid medium comprises one or more of: spherical solid or hollow bodies, ellipsoidal solid or hollow bodies, polyhedral solid or hollow bodies, and cylindrical solid or hollow bodies; and/or the liquid medium is water or oil.

3. The power tool (100) of claim 2, wherein the solid media comprises a steel ball cluster.

4. The power tool (100) according to claim 3,

the filling rate of the damping medium in the damping cavity is 50-80%; and/or

The solid medium has a maximum outer dimension of no more than 5mm.

5. The power tool (100) according to any one of claims 1 to 4, wherein the power tool (100) defines one or more damping chambers extending along a longitudinal axis (L), the cutters being inserted into the cutter holder (120) along the longitudinal axis (L), and the damping chambers comprising one or more damping chambers being arranged symmetrically with respect to a longitudinal plane (P) through the longitudinal axis (L).

6. The power tool (100) of claim 5, wherein the damping chamber comprises one or more housing damping chambers and/or one or more additional damping chambers, wherein:

the tool housing (110) comprising a motor housing portion (20) housing the drive motor (22) and a main housing portion (10) housing the transmission mechanism (30), each of the one or more housing dampening chambers being provided by one or both of the motor housing portion (20) and the main housing portion (10); and is provided with

The one or more additional damping chambers are provided by one or more additional members attached within a void space inside the tool housing or attached outside the tool housing and stationary during operation of the power tool.

7. The power tool (100) according to claim 6, wherein the transmission mechanism (30) comprises an impact transmission assembly (310) for converting a rotational motion output by a drive motor (22) into a reciprocating linear motion of the cutter along a longitudinal axis (L), the impact transmission assembly comprising a pendulum bearing (312) driven by an output shaft of the drive motor (22), at least one of the one or more additional components being provided in a spatial region (A) in the tool housing in the vicinity of the pendulum bearing.

8. The power tool (100) according to any one of claims 1 to 4, wherein the transmission mechanism (30) comprises a rotary transmission assembly (320) for transmitting the rotary motion output by the drive motor (22) to the cutter to rotate the cutter.

9. The power tool according to any one of claims 1 to 4, characterized in that the power tool (100) is a hand-held power tool.

10. The power tool according to claim 9, characterized in that the power tool (100) is a hammer or a hammer drill.

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