CN212445065U

CN212445065U - Electric hammer drill

Info

Publication number: CN212445065U
Application number: CN202021133621.4U
Authority: CN
Inventors: 金松涛
Original assignee: Bosch Power Tools China Co Ltd
Current assignee: Bosch Power Tools China Co Ltd
Priority date: 2020-06-18
Filing date: 2020-06-18
Publication date: 2021-02-02
Anticipated expiration: 2030-06-18

Abstract

The electric hammer drill comprises a shell internally provided with a motor and a reduction gear and a working head assembled on the electric hammer drill, wherein the electric hammer drill forms a rotating working mode and a non-rotating working mode through a transmission device connected between the reduction gear and the working head, and the motor has a second rotating direction opposite to a first rotating direction for enabling the working head to rotate forward and output under the rotating working mode under the non-rotating working mode. This application commutates the motor under the class of non-rotation mode, on the basis that does not influence normal function and realize, has utilized the reverse direction meshing transmission power take off under the class of non-rotation mode of gear, has shared the wearing and tearing of gear, prolongs the life of gear train.

Description

Electric hammer drill

Technical Field

The application relates to the field of electric tools, in particular to an electric hammer drill.

Background

Many hand-held power tools, such as reciprocating saws, hammer drills, electric picks, and the like, utilize a motor to drive a tool bit of the power tool to perform a desired action. The tool is provided with a motion transmission mechanism between a motor and a tool head, and the gear transmission mechanism is widely applied to the application due to the advantages of compact structure, high transmission precision, wide application range, large transmission ratio and the like. In applications utilizing gear trains as the transmission, the teeth of the meshing gears are typically formed with a hardened layer to resist wear during meshing and to extend the useful life of the gears. However, after the gear is used and engaged for a long time, the hardened layer on the surface of the gear teeth gradually wears and even falls off, which further accelerates the wear of the gear, and the gear is a short plate of the whole tool life, thereby limiting the service life of the whole electric tool.

Accordingly, there is a need for improvement to overcome the technical problems in the prior art.

SUMMERY OF THE UTILITY MODEL

What this application will solve is that electric tool's gear wears fast problem.

In order to solve the technical problem, the application provides an electric hammer drill, including built-in casing that has motor and reduction gear and assemble in the working head of electric hammer drill, electric hammer drill forms rotatory class mode and non-rotatory class mode through connecting in transmission between reduction gear and the working head, the motor has rather than making under rotatory class mode the second rotation direction that the first rotation direction of working head corotation output is opposite under non-rotatory class mode.

Furthermore, the electric hammer drill is provided with a hammer pipe for driving the working head to rotate and a mode switching knob for driving the transmission device to shift gears, and the electric hammer drill obtains a specific working mode by detecting whether the hammer pipe rotates or the position corresponding to the mode switching knob.

Further, when the position of the mode switching knob and the related components is confirmed to be the non-rotation type working mode, the motor is switched to the second rotation direction.

Further, the electric hammer drill obtains the position of the mode switching knob and the related components thereof through a sensor or a mechanical transmission mode.

Furthermore, the electric hammer drill comprises a Hall sensor which is fixedly arranged on the shell and used for detecting signals related to the working mode.

Further, the electric hammer drill is provided with a forward and reverse rotation switch, and when the forward and reverse rotation switch is located at a forward rotation position, the rotation direction of the motor is a first rotation direction.

Further, when the forward and reverse rotation switch is located at the reverse rotation position, the motor always keeps the second rotation direction.

Furthermore, the electric hammer drill comprises a control circuit board which receives a forward and reverse rotation switch signal and sends a reversing signal to the motor.

Further, the rotation-type working mode comprises a single-drill mode and/or a hammer-drill mode; the non-rotating class of operating modes includes a single chisel mode.

Furthermore, the electric hammer drill comprises a control circuit board, and the control circuit board collects the working mode information of the electric hammer drill and controls the motor to commutate.

This application commutates the motor under the class of non-rotation mode, on the basis that does not influence normal function and realize, has utilized the reverse direction meshing transmission power take off under the class of non-rotation mode of gear, has shared the wearing and tearing of gear, prolongs the life of gear train.

Drawings

The present application will be more fully understood by reference to the following detailed description of specific embodiments in conjunction with the accompanying drawings. Wherein:

FIG. 1 is a schematic view of a partial cross-sectional structure of an electric hammer drill according to the present application;

FIG. 2 shows a schematic structural view of the mode shift knob and gear assembly of the present application;

fig. 3 shows a schematic structural diagram of the mode switching knob and the dial thereof according to the present application.

Detailed Description

An embodiment of an electric hammer drill 100 according to the present invention will be described in detail below with reference to fig. 1 to 3. Some background discussion regarding the hammer drill 100 will be provided herein with respect to specific design details of the present application. Generally, electric hammer drills have three types of power outputs (single drill, single chisel and hammer), in which the single drill outputs only rotation, the single chisel outputs only impact, and the hammer simultaneously outputs both rotation and impact, it being seen that the single chisel mode is independent of the rotation output by the motor, while the single drill and hammer modes are related, and in most cases the direction of these rotary motions is also meaningful, e.g. in single drill, forward rotation facilitates drilling and chip ejection, while reverse rotation facilitates the ejection of the drill bit. This is why we choose the non-rotating type operation mode for commutation later on, because the premise of improved design is to ensure the normal use of the existing product.

The electric hammer drill 100 comprises a shell 30 internally provided with a motor 10 and a reduction gear 20 and a working head 40 assembled on the electric hammer drill 100, wherein the electric hammer drill 100 forms a rotary working mode (such as a single drill mode and/or a hammer drill mode) and a non-rotary working mode (a single chisel mode) through a transmission device 50 connected between the reduction gear 20 and the working head 40, and the motor 10 has a second rotating direction opposite to a first rotating direction output by positive rotation of the working head 40 under the non-rotary working mode. That is, if the direction in which the working head 40 is normally rotated and output in the rotation-type operation mode is defined as a first rotation direction of the motor 10, the motor 10 has a second rotation direction opposite to the first rotation direction in the non-rotation-type operation mode. This application is selected to commutate the motor rotation direction of non-rotatory class mode, on the basis that does not influence normal function and realize, has utilized the reverse direction meshing transmission power take off under the non-rotatory class mode of gear, has shared the wearing and tearing of gear, prolongs the life of gear train.

The electric hammer drill 100 is provided with a hammer pipe for driving the working head 40 to rotate and a mode switching knob 60 for driving the transmission device 50 to shift gears, and the electric hammer drill 100 obtains a specific working mode by detecting whether the hammer pipe rotates or the position corresponding to the mode switching knob 60. The judgment of the working mode can be various, and whether the judgment is direct or indirect, the judgment only needs to be carried out if the judged parameters have a substantial corresponding relation with the working mode of the electric hammer drill. When the position of the mode switching knob 60 and its associated components is determined to be a non-rotational type operation mode, the motor 10 is switched to a second rotational direction. Since the non-rotational type of operation does not output rotation itself, the associated switching is done inside the housing 30 and the user does not typically feel the switching. Specifically, the hammer drill 100 may obtain the position of the mode switching knob 60 and its associated components by means of a sensor (e.g., a hall sensor) or a mechanical transmission (e.g., the paddle 80 coupled to the mode switching knob 60). Specifically, in the present embodiment, the electric hammer drill 100 includes a control circuit board (not shown) for controlling the operation state of the motor and a hall sensor electrically connected to the control circuit board and fixedly disposed on the housing 30 to detect signals related to the working mode, the mode switching knob 60 mechanically drives the transmission device 50 to shift gears, and when the hall sensor acquires that the electric hammer drill 100 is in the non-rotation type working mode (for example, when the hall sensor senses that the dial associated with the single chisel mode is approaching and reaches a predetermined position, it is determined as the non-rotation type working mode), the hall sensor feeds back information to the control circuit board, thereby controlling the change of the internal rotation direction of the motor 10.

As previously discussed, it is still clear that the improved objectives of the present application are achieved when many hammer drills 100 are provided with forward and reverse rotation switches 70 due to operator demand for forward and reverse rotation outputs in a rotary-type mode of operation. Since the electric hammer drill 100 is mostly applied to the drilling and hammering mode, it is desirable to reduce the wear of the reduction gear 20 when outputting the forward rotation, and the first rotation direction is always the rotation direction of the motor when the electric hammer drill 100 outputs the forward rotation regardless of the presence or absence of the forward and reverse rotation switch 70. That is, when the forward/reverse switch 70 is located at the forward rotation position, the rotation direction of the motor 10 is the first rotation direction. When the forward/reverse switch 70 is in the reverse rotation position, the rotation direction of the motor 10 is already switched to the second rotation direction by the forward/reverse switch 70, so that the motor 10 is not reversed by switching the hammer drill 100 from the rotary type operation mode to the non-rotary type operation mode. That is, when the forward/reverse switch 70 is in the reverse position, the motor 10 always maintains the second rotation direction regardless of whether the electric hammer drill 100 is currently in the rotary type operation mode or the non-rotary type operation mode.

The above detailed description is merely illustrative of the present application and is not intended to be limiting. For example, the electric hammer drill in this embodiment includes a control circuit board (not shown) for receiving a forward and reverse rotation switch signal and sending a reversing signal to the motor, and in some other embodiments, there is also a possibility that the reversing of the end working head is realized by adding one more gear in the reduction gear transmission chain. In summary, those skilled in the art can make various changes and modifications without departing from the scope of the present application, and therefore all equivalent technical solutions also belong to the scope of the present application, and the protection scope of the present application should be defined by the claims.

Claims

1. An electric hammer drill (100) comprises a shell (30) internally provided with a motor (10) and a reduction gear (20) and a working head (40) assembled on the electric hammer drill (100), wherein the electric hammer drill (100) forms a rotation type working mode and a non-rotation type working mode through a transmission device (50) connected between the reduction gear (20) and the working head (40), and is characterized in that: the motor (10) has a second rotation direction opposite to the first rotation direction for enabling the working head (40) to rotate forward and output under the rotation type working mode under the non-rotation type working mode.

2. The electric hammer drill (100) according to claim 1, wherein the electric hammer drill (100) has a hammer tube for driving the working head (40) to rotate and a mode switching knob (60) for driving the transmission device (50) to shift gears, and the electric hammer drill (100) obtains a specific working mode by detecting whether the hammer tube is rotated or whether the mode switching knob (60) is correspondingly positioned.

3. The electric hammer drill (100) according to claim 2, wherein the motor (10) is switched to the second rotational direction when the position of the mode switching knob (60) and its associated components is determined to be the non-rotary type operation mode.

4. The electric hammer drill (100) according to claim 3, wherein the position of the mode switching knob (60) and its associated components is obtained by the electric hammer drill (100) through sensors or mechanical transmission.

5. The electric hammer drill (100) according to claim 4, wherein the electric hammer drill (100) includes a Hall sensor secured to the housing (30) for detecting signals associated with a non-rotating type of operating mode.

6. The electric hammer drill (100) according to claim 1, wherein the electric hammer drill (100) has a forward/reverse switch (70), and the rotation direction of the motor (10) is a first rotation direction when the forward/reverse switch (70) is in the forward rotation position.

7. The electric hammer drill (100) of claim 6, wherein the motor (10) always maintains the second rotational direction when the forward and reverse rotation switch (70) is in the reverse rotation position.

8. The electric hammer drill (100) according to claim 7, wherein the electric hammer drill (100) includes a control circuit board (80) that receives a forward and reverse rotation switch (70) signal and sends a reverse signal to the motor (10).

9. Electric hammer drill (100) according to any one of claims 1-8, wherein the rotary-type working mode comprises a single drill mode and/or a hammer drill mode; the non-rotating class of operating modes includes a single chisel mode.

10. An electric hammer drill (100) according to any one of claims 1 to 7, wherein the hammer drill (100) comprises a control circuit board (80), and the control circuit board (80) collects the operation mode information of the hammer drill (100) and controls the motor (10) to commutate.