CN211333061U

CN211333061U - Electric tool

Info

Publication number: CN211333061U
Application number: CN201922428022.9U
Authority: CN
Inventors: 顾伟; 汤庆云
Original assignee: Bosch Power Tools China Co Ltd
Current assignee: Bosch Power Tools China Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-08-25
Anticipated expiration: 2029-12-30
Also published as: DE102020216556A1; BR102020026808A2

Abstract

A power tool, comprising: a bit holder configured to be able to clamp an impact type bit and a non-impact type bit, a working mode gear comprising an impact type gear and a non-impact type gear, and a decision element electrically connected to the bit holder and the working mode gear and configured to not perform or de-rate an output action corresponding to the impact type gear if the bit holder clamps a non-impact type bit and the working mode gear is in the impact type gear.

Description

Electric tool

Technical Field

The present application relates to a power tool.

Background

In the case of existing power tools, the shank of the plug-in drill used is fixedly clamped in a drill holder of the power tool. The user selects the operating mode of the power tool via an operating mode shift rotatably provided on the power tool. Depending on the different operating modes of the power tool, different types of plug-in drills can be fixed in the drill holder. For the rotary drive, the shank of the plug-in drill has a non-cylindrical cross section, for example a so-called "SDS Plus" profile, which has two driving grooves which are diametrically opposite one another, extend in the longitudinal direction of the shank and are open toward the rear end. Complementary driving ribs on the inner circumferential surface of the drill holder form a positive fit with these driving grooves when the plug-in drill is inserted into the drill holder.

In the conventional power tool, the position of the operation mode shift (i.e., the current operation mode of the power tool) may be detected by a sensor. The power tool may automatically apply an optimized configuration (e.g., rotational speed and output power, etc.) corresponding to the current operating mode based on the detected operating mode.

It should be noted that, for example, only SDS Plus drill bits may be used in the hammer drilling mode and the drilling mode, misuse of non-SDS Plus drill bits may result in power tool failure or even damage. The bit holder typically rotates with the bit, requiring a judgment element to determine whether bit misuse has occurred. The existing electric tool is lack of a misuse prevention device with a simple structure and a corresponding alarm device.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problem, the present application provides an electric tool, including: a bit holder configured to be able to clamp both percussive and non-percussive drill bits, a working mode gear comprising an impact gear and a non-impact gear, and a decision element electrically connected to the bit holder and the working mode gear and configured to not affect the execution of a drilling action but not to execute a percussive action or to de-rate the execution of a percussive action if the bit holder clamps a non-percussive drill bit and the working mode gear is in the impact gear.

With the power tool of the present application, the operating mode stop can be combined with the drill bit type to determine drill bit misuse. The decision element may issue an alarm in case of a bit misuse and not perform or de-rate an output action corresponding to the impact-like gear to avoid malfunction or damage of the power tool.

Drawings

The foregoing and other aspects of the present application will be more fully understood and appreciated by reference to the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view of a power tool of the present application;

FIG. 2 shows a schematic view of a bit holder and a decision element of the power tool of FIG. 1; and

fig. 3 shows a cross-sectional view of the bit holder of the power tool of fig. 1.

Detailed Description

To assist those skilled in the art in understanding the subject matter claimed herein, specific embodiments thereof are described below in detail with reference to the accompanying drawings.

Fig. 1 shows a schematic view of the power tool of the present application. The electric power tool includes a housing 1, a spindle 2, a bit holder 3, a judging member 4, an operation mode shift 13, an alarm member 14, a bit 15, a grip 16, a power cord 17, and a switch 18. A spindle 2 is rotatably disposed in the housing 1 for rotation about an axis of rotation a under drive of a motor (not shown) to perform the primary function of the power tool. A bit holder 3 is fixed to the spindle 2 and protrudes from the housing 1 for holding a bit therein, such as a percussive-type bit and a non-percussive-type bit. Percussive type bits include SDS type bits and other types of bits. SDS-type bits include SDS bits, SDS Plus bits, and SDS Max bits. Non-percussive type bits include round shank, square shank, or hexagonal shank bits. The bit holder 3 comprises an SDS clamp head and a three jaw chuck with a common bit holding cavity. The judgment element 4 is provided in the housing 1 separately from the bit holder 3. The operating mode gear 13 is rotatably arranged on the housing 1 and comprises an impact-type gear (e.g. hammer drilling gear and chisel gear) and a non-impact-type gear (e.g. drill gear). The decision element 4 is configured to cause an alarm element 14 provided on the housing 1 and electrically connected to the decision element 4 to sound an alarm in an audible or visual manner in case the type of drill bit clamped on the bit holder 3 does not correspond to the position in which the operating mode 13 is located. The drill bit 15 is clamped in the drill bit holder 3 in a form-fitting manner. A grip 16 is attached to the housing 1 for providing additional stability when operating the power tool. The power cord 17 is connected to the motor to provide power. A switch 18 is pivotally connected to the housing 1 to control the starting and stopping of the motor.

Since the bit holder 3 is fixed to the main shaft 2, it rotates together with the main shaft 2. In this case, a method of transmitting information on the drill held in the drill holder 3 acquired by the drill holder 3 to the judging member 4 provided in the housing 1 will be described below.

Fig. 2 shows a schematic view of a bit holder of the power tool in fig. 1. The bit holder 3 includes a control unit 5 and a conductive ring, and is configured to be electrically connected to the judging element 4 via the conductive ring and a conductive brush in contact with the conductive ring. In this particular embodiment, the bit holder 3 comprises a first conductive ring 6 and a second conductive ring 7. The bit holder 3 is configured to be electrically connected to the judging element 4 via a first conductive ring 6 and a first conductive brush 8 in contact with the first conductive ring 6, and a second conductive ring 7 and a second conductive brush 9 in contact with the second conductive ring 7. It should be noted that the bit holder 3 may comprise more conductive rings to suit different applications. The judging element 4 is configured to supply power to the control unit 5 via the first conductive brush 8 and the first conductive ring 6. The control unit 5 comprises at least two sensors. In the present embodiment, the control unit 5 includes a first sensor 11 and a second sensor 12. The control unit 5 is configured to transmit the signals generated by the first and

second sensors

11, 12 to the decision element 4 via the second conductive ring 7 and the second conductive brush 9.

Fig. 3 shows a cross-sectional view of the bit holder of the power tool of fig. 1. In the present embodiment, the drill 15 is a percussion type drill. The first sensor 11 and the second sensor 12 are disposed so as to be spaced apart by an angle θ in the circumferential direction of the bit holder 3. In view of the geometry of the percussive type drill bit, θ is less than 180 °. In the present embodiment, the first sensor 11 and the second sensor 12 are hall sensors and are configured to measure the distance between them and the drill bit held in the bit holder 3, respectively. In the case where no drill bit is clamped in the bit holder 3, the distances between the first sensor 11 and the second sensor 12 and the drill bit are set to be equal to the first and second preset distances, respectively. In the case where the impact type drill is held in the bit holder 3, the distances between the first and

second sensors

11 and 12 and the impact type drill are a first preset length a and a second preset length b, respectively.

The judgment logic of the misuse prevention function of the present application will be described below. The judging element 4 judges the type of the drill bit by recognizing the shank profile information of the drill bit inserted into the bit holder 3 in a contact or non-contact manner. The following description will be given by taking a non-contact system as an example. In the case where the distance measured by the first sensor 11 is equal to the first preset length a and the distance measured by the second sensor 12 is equal to the second preset length b, the judging element 4 judges that the drill bit held in the bit holder 3 is a percussive type drill bit. The judging element 4 judges that the drill bit held in the drill bit holder 3 is a non-impact type drill bit, when the distance measured by the first sensor 11 is not equal to the first preset length a and is not equal to the first preset distance and the distance measured by the second sensor 12 is not equal to the second preset length b and is not equal to the second preset distance. In the case where the distance measured by the first sensor 11 is equal to the first preset length and the distance measured by the second sensor 12 is equal to the second preset length, the judging member 4 judges that no drill is clamped in the drill holder 3.

As shown in the following table, in the present embodiment, the following relationship exists between the shift position of the operation mode shift, the type of the drill bit held by the bit holder, and the operation performed by the determination element.

When the operating mode shift 13 is in the non-impact type shift, the determination element 4 does not affect the execution of the output operation corresponding to the impact type shift when the drill holder 3 holds an impact type drill, a non-impact type drill, or no drill.

When the operation mode range 13 is in the impact-type range, the determination element 4 does not affect the execution of the output operation corresponding to the impact-type range when the impact-type drill is clamped by the bit holder 3. The judgment element 4 does not execute or derates the output operation corresponding to the impact type gear when the non-impact type drill bit is clamped or any drill bit is not clamped on the drill bit holder 3.

Although the application is illustrated and described herein with reference to specific embodiments, the application is not intended to be limited to the details shown. Rather, various details of the application may be modified within the scope and equivalents of the claims.

Claims

1. A power tool, characterized in that the power tool comprises:

a bit holder (3) configured to be capable of clamping a percussion-type bit and a non-percussion-type bit,

an operating mode gear (13) comprising an impact-type gear and a non-impact-type gear, and

a decision element (4) electrically connected to the bit holder and the working mode gear and configured to not perform or de-rate an output action corresponding to an impact type gear if the bit holder holds a non-impact type drill bit and the working mode gear is in the impact type gear.

2. The power tool of claim 1,

the percussive drill bit is a drill bit with axial percussive stroke grooves, and

the non-percussive type drill bit is a drill bit without an axial percussive stroke groove.

3. The power tool of claim 1,

the impact-type gear includes a hammer drill gear and a chisel gear, an

The non-impact gear comprises a drill gear.

4. The power tool of claim 1,

the judging element is configured to not influence the execution of the output action no matter whether the bit holder clamps an impact type bit or a non-impact type bit or not under the condition that the working mode gear is in a non-impact type gear.

5. The power tool of claim 1,

the percussive type drill bit includes an SDS type drill bit,

the non-percussive drill bit comprises a round, square or hexagonal shank drill bit, an

The bit holder includes an SDS clamp head and a three jaw chuck having a common bit holding cavity.

6. The power tool of claim 1,

the decision element is further configured to not perform or de-rate an output action corresponding to an impact type gear if the bit holder does not grip a bit and the operating mode gear is in the impact type gear.

7. The power tool according to any one of claims 1 to 6,

the judging element judges the type of the drill bit by recognizing shank profile information of the drill bit inserted into the bit holder in a contact or non-contact manner.

8. The power tool according to any one of claims 1 to 6,

the power tool comprises a sensor disposed in the bit holder and an electrically conductive ring (6, 7) electrically connected to the sensor, the sensor obtaining power from the power tool via the electrically conductive ring and an electrically conductive brush (8, 9) in contact with the electrically conductive ring.

9. The power tool of claim 8,

the power tool includes at least two sensors,

the at least two sensors are disposed at an angle (theta) apart in a circumferential direction of the bit holder and are configured to measure a distance from a bit shank held in the bit holder, respectively,

the power tool further comprises a control unit for processing the sensor data,

the at least two sensors are Hall sensors, an

The at least two sensors are spaced apart in the circumferential direction of the bit holder by an angle of less than 180 °.

10. The power tool according to any one of claims 1 to 6,

the power tool further comprises an alarm element (14), and

the alarm element is configured to audibly or visually issue a reminder if the bit holder is holding a non-impact type bit and the operating mode gear is in an impact type gear.