CN110394769B

CN110394769B - Electric tool

Info

Publication number: CN110394769B
Application number: CN201810371235.XA
Authority: CN
Inventors: 郑祥格; 谢炬烽
Original assignee: Bosch Power Tools China Co Ltd
Current assignee: Bosch Power Tools China Co Ltd
Priority date: 2018-04-24
Filing date: 2018-04-24
Publication date: 2022-03-01
Anticipated expiration: 2038-04-24
Also published as: CN110394769A; WO2019206022A1; DE112019002136T5

Abstract

The present application provides an electric tool, including: a clamping device for clamping or releasing the drill bit; an impact device including an impact portion driven to impact the drill bit and a power source for supplying power; the impact part is provided with a bearing position and an unloading position and can reciprocate between the bearing position and the unloading position; at the load-bearing position, the impact portion is coupled with the power source and is capable of impacting a drill bit; at the unloading position, the impact portion is decoupled from the power source; and a reset mechanism for providing a reset force for holding the impact portion in the unloaded position; the impact portion is held in the unloaded position when the force transmitted by the drill bit to the impact portion is less than the reset force provided by the reset mechanism. According to the technical scheme of this application, can not keep the impact portion in the uninstallation position when the drill bit supports the pressure work piece, effectively avoid various maloperations.

Description

Electric tool

Technical Field

The present invention relates to power tools, and more particularly, to a power tool having a reset mechanism.

Background

In the prior art, an electric hammer and an electric drill are both mature electric tools. Among them, the electric hammer is used for impact and drilling, and the electric drill is mainly used for drilling. To perform different functions, these power tools typically employ different drills, such as: fluted shank drills, round shank drills, hexagonal drills, or the like. There are some drill bits having a relatively small size, and for these drill bits, if they are not completely clamped during assembly or standby, there is a high possibility that the drill bits are impacted and ejected due to malfunction, thereby inducing safety accidents.

Disclosure of Invention

The main technical problem that this application will solve is to provide the tool holding system who improves the maloperation condition.

In order to solve the above technical problem, the present application provides an electric power tool including: a clamping device for clamping or releasing the drill bit; an impact device including an impact portion driven to impact the drill bit and a power source for supplying power; the impact part is provided with a bearing position and an unloading position and can reciprocate between the bearing position and the unloading position; at the load-bearing position, the impact portion is coupled with the power source and is capable of impacting a drill bit; at the unloading position, the impact portion is decoupled from the power source; and a reset mechanism for providing a reset force for holding the impact portion in the unloaded position; the impact portion is held in the unloaded position when the force transmitted by the drill bit to the impact portion is less than the reset force provided by the reset mechanism.

According to the technical scheme of the application, the reset mechanism is arranged to provide reset force for keeping the impact part at the unloading position; the impact part can be kept at the unloading position when the drill bit does not abut against the workpiece or when the force transmitted to the impact part by the drill bit is smaller than the reset force provided by the reset mechanism, so that various misoperation can be effectively avoided.

Drawings

The present application will be more fully understood from the detailed description given below with reference to the accompanying drawings, in which like reference numerals refer to like elements in the figures. Wherein:

fig. 1 shows a schematic axial sectional view of an embodiment of a power tool.

Detailed Description

Referring to fig. 1, an electric tool according to an embodiment of the present application includes: a gripping device 100 for gripping or releasing the drill bit 400; an impact device 200 having an impact portion 210 driven to impact the drill bit 400 and a power source for supplying power; and a reset mechanism 300 for providing a reset force for holding the striking part 210 at the unloading position b. The impact portion 210 has a loading position a and an unloading position b, and can reciprocate between the loading position a and the unloading position b; when the striking part 210 moves to the loading position a, the striking part 210 is coupled with a power source and can strike the drill 400; when the impact part 210 moves to the unloading position b, the impact part 210 is decoupled from the power source; and the reset mechanism 300 provides reset force for keeping the impact part at the unloading position, so that the impact part 210 can be kept at the unloading position b when the drill bit does not press against the workpiece or when the force transmitted from the drill bit 400 to the impact part 210 is less than the reset force provided by the reset mechanism 300, thereby effectively avoiding various misoperation.

The components of the power tool, such as the clamping device 100, the impact device 200, and the return mechanism 300, will be described one by one.

The clamping device can be a common clamping device in the field of electric tools, and can also be an improved clamping device as long as the clamping device can be matched and connected with the impact device and the reset mechanism mentioned in the embodiment of the application. Some of the structural features of a clamping device will be described herein in connection with fig. 1 in order to better understand the present concepts. Specifically, the clamping device 100 includes a base 110. Wherein, set up the mounting hole that link up along the axial in this base member 110, this mounting hole one end extends to the assembly or the dismantlement mouth of all kinds of drill bits to adorn or take out all kinds of drill bits, and this end is defined as the front end in this scheme. The other end extends to connect to a percussion device described later in order to drive the drill bit loaded in to perform the work task, and this end is defined in this solution as the rear end.

In the direction from left to right in fig. 1, the first-type through hole and the second-type through hole are sequentially formed in the base 110. Wherein in this embodiment three through holes of the first type are inclined towards the front end and extend through the base body 110 for inserting the jaws 120 and thereby performing a clamping or releasing operation on the round shank drill bit. In addition, a second type of through hole is inclined toward the front end and penetrates the base body 110, which is used for inserting the locking pin 130 and thereby performing a clamping or releasing operation of the fluted drill.

In addition, a dust cap 140 may be added to the front end of the mounting hole to prevent dust from entering the mounting hole of the tool when the tool is not in use.

The aforementioned clamping device 100 is connected to the impact device 200 by means of a ball 500.

With continued reference to fig. 1, the impact device 200 is configured as a tube 230, and the impact portion 210 is disposed within the tube 230 and is capable of reciprocating along the tube 230 when driven, being driven by a power source when moving toward the rear end, and striking the assembled drill bit 400 when moving forward, thereby driving the drill bit 400 to impact a workpiece to achieve a desired machining.

The impact device 200 further includes a transmission part 220, the transmission part 220 being disposed between the impact part 210 and the power source, being capable of being coupled with the power source and transmitting power to the impact part 210; wherein, when the striking part 210 is at the loading position a, it is coupled with the power source via the transmission part 220 and is capable of striking the drill bit 400; when the striking part 210 is at the unloading position b, the striking part 210 is decoupled from the transmission part 220 and is not driven any more, so that it can be kept still.

In addition, the impact device 200 further includes a guide bushing 240, the guide bushing 240 is disposed around the impact portion 210, and the guide bushing 240 is disposed with a receiving groove 241 at a side close to the transmission portion 220; wherein, at the unloading position b, the transmission part 220 is held in the accommodating groove 241 and decoupled from the power source; therefore, the transmission part is fixed, and the transmission part can execute impact action without being continuously driven by a power source in a non-working state. At the loading position a, the impact portion 210 pushes the transmission portion 220 out of the receiving groove 241, and the transmission portion 220 is coupled to the power source and can impact the drill 400.

More specifically, a first accommodation cavity 242 is axially disposed in the guide bushing 240, and the reset mechanism 300 is disposed in the first accommodation cavity 242; in the unloading position b, the reset mechanism 300 presses the impact portion 210 against a first side of the first accommodating cavity 242 away from the power source. Thereby providing a space to limit the impact portion 210 to ensure that it can move between the loading position a and the unloading position b.

Optionally, the impact device 200 may further include a thrust collar 250, the thrust collar 250 is disposed around the impact portion 210, and the thrust collar 250 is used to provide cushioning for the impact portion 210 and absorb energy of the impact portion 210, so as to prevent the impact portion 210 from colliding rigidly with the tube 230 to be worn excessively.

At this time, a second accommodating cavity 251 may be axially disposed in the thrust collar 250, and an accommodating space c is defined by the second accommodating cavity 251 and the first accommodating cavity 242; in the unloading position b, the reset mechanism 300 presses the impact portion 210 against the first end of the accommodating space c away from the power source. Thereby forming a complete cavity space to confine the impact portion 210 and ensure that it can move between the loading position a and the unloading position b.

In a further embodiment, which is not shown, the guide bush does not have a first receiving space, but it is arranged on the side facing away from the transmission part against the end face. At this time, the first end of the return mechanism is supported on the abutting end surface, and the second end of the return mechanism applies a return force to the impact portion. This also makes it possible to press the impact portion into the unloading position b without any other external force.

The reset mechanism 300 and the impact portion may be connected in a variety of ways to achieve a reliable transfer of force. For example, the striking section 210 is provided with a boss 211 in the circumferential direction, and the reset mechanism 300 applies a reset force to the striking section 210 directly or indirectly against the boss 211.

Furthermore, as a specific implementation form, the return mechanism 300 comprises a resilient element 310, the resilient element 310 holding the percussion part 210 pressed against the unloading position b when the force transmitted by the drill 400 to the percussion part 210 is smaller than the spring force provided by the resilient element 310.

Of course, in the teaching of the above-listed embodiments, it can be seen that there are many modifications to the specific arrangement position and structure form of the reset mechanism, as long as it can apply the reset force to the impact portion so as to be able to be held at the unloading position b when the impact portion is not subjected to other external forces.

Further, the power tool may be an electric hammer, a hammer drill, or a hand-held drill, as examples of specific applications.

The above detailed description is merely illustrative of the present application and is not intended to be limiting. In the present application, relative terms such as left, right, up, and down are used to describe relative positional relationships, and are not intended to limit absolute positions. Various changes and modifications can be made by one skilled in the art without departing from the scope of the present application, and 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 power tool, characterized by comprising:

a gripping device (100) for gripping or releasing a drill bit (400);

an impact device (200) including an impact portion (210) driven to impact the drill bit (400) and a power source for supplying power; wherein the impact section (210) has a loading position (a) and an unloading position (b) and is capable of reciprocating between the loading position (a) and the unloading position (b); -in the loading position (a), the percussion portion (210) is coupled with the power source and is capable of percussion with a drill bit (400); in the unloading position (b), the impact portion (210) is decoupled from the power source; and

a reset mechanism (300) for providing a reset force for holding the impact portion (210) in the unloaded position (b); the percussion part (210) is held in the unloading position (b) when the force transmitted by the drill bit (400) to the percussion part (210) is smaller than the reset force provided by the reset mechanism (300).

2. The power tool according to claim 1, further comprising a transmission portion (220), the transmission portion (220) being provided between the impact portion (210) and the power source, being capable of coupling with the power source and transmitting power to the impact portion (210); wherein, in the loading position (a), the percussion portion (210) is coupled with the transmission portion (220) and is capable of percussion with a drill bit (400); in the unloading position (b), the impact portion (210) is decoupled from the transmission portion (220).

3. The power tool according to claim 2, further comprising a guide bushing (240), wherein the guide bushing (240) is disposed around the striking portion (210), and the guide bushing (240) is provided with a receiving groove (241) at a side close to the transmission portion (220); wherein, at the unloading position (b), the transmission part (220) is held in the accommodation groove (241) and decoupled from the power source; at the loading position (a), the striking part (210) pushes the transmission part (220) out of the accommodation groove (241), and the transmission part (220) is coupled with a power source and capable of striking a drill bit (400).

4. The power tool according to claim 3, characterized in that a first housing cavity (242) is axially provided in the guide bushing (240), the return mechanism (300) being provided in the first housing cavity (242); wherein, at the unloading position (b), the reset mechanism (300) presses the impact part (210) against a first side of the first accommodating cavity (242) away from the power source.

5. The power tool of claim 4, further comprising a thrust ring (250), the thrust ring (250) being disposed around the impact portion (210), and the thrust ring (250) being configured to provide cushioning to the impact portion (210).

6. The power tool according to claim 5, characterized in that a second accommodating cavity (251) is axially arranged in the thrust ring (250), and the second accommodating cavity (251) and the first accommodating cavity (242) enclose an accommodating space (c); wherein, at the unloading position (b), the reset mechanism (300) presses the impact part (210) against the first end of the accommodating space (c) far away from the power source.

7. The power tool according to claim 3, characterized in that the guide bushing (240) is provided with an abutment end face on the side facing away from the transmission part (220), on which abutment end face a first end of the return mechanism (300) bears and a second end of the return mechanism (300) applies a return force to the impact part (210).

8. The power tool according to any one of claims 1 to 7, characterized in that the return mechanism (300) comprises a resilient element (310), the resilient element (310) holding the impact portion (210) against an unloading position (b) when the force transmitted by the drill bit (400) to the impact portion (210) is smaller than the resilient force provided by the resilient element (310).

9. The power tool according to any one of claims 1 to 7, wherein the striking portion (210) is provided with a boss (211) in a circumferential direction, and the return mechanism (300) abuts against the boss (211) to apply a return force to the striking portion (210).

10. The power tool according to any one of claims 1 to 7, characterized in that the power tool comprises: an electric hammer, a hammer drill or a hand-held drill.