CN108605667B

CN108605667B - Electric tool

Info

Publication number: CN108605667B
Application number: CN201611110408.XA
Authority: CN
Inventors: 杨庆辉
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2016-12-06
Filing date: 2016-12-06
Publication date: 2021-07-13
Anticipated expiration: 2036-12-06
Also published as: CN108605667A

Abstract

An electric tool comprises a main body, a motor, a fan, a working accessory and a brake control circuit, wherein the motor and the fan are arranged in the main body, the fan is driven by the motor to rotate, the working accessory is detachably connected to the main body, the brake control circuit comprises a control switch and a winding assembly, the control switch and the motor are electrically connected to form a running loop and a brake loop, and the winding assembly is electrically connected between the control switch and the motor to store energy in the running loop and generate counter electromotive force in the brake loop to brake the motor to stop driving the fan. In the electric tool, the brake control circuit is used for braking when the motor stops, so that the rotation time of the fan is shortened, the fan stops rotating after the working accessory is detached from the main body, and the personal safety of an operator is guaranteed.

Description

Electric tool

Technical Field

The invention relates to the field of gardening electric tools, in particular to an electric tool with a brake control circuit.

Background

Power tools for circular arts are devices for sweeping or cleaning grass or other surfaces, such as suction blowers and the like, which typically have a body with a port for removably attaching a blow pipe and/or a suction pipe. The blowing pipe is used for blowing, and high-speed airflow blown from the blowing pipe blows fallen leaves and other objects scattered on the ground to gather; the suction pipe is used for sucking air, the impeller rotates at high speed, and the formed suction airflow sucks the ground fallen leaves and dust together so as to crush the ground fallen leaves and discharge the ground fallen leaves and the dust into the dust collection bag through the dust collection pipe.

However, due to the detachable connection design of the blowing and sucking pipe and the main body, the blowing and sucking pipe can be frequently detached, and if the fan accommodated in the main body is still rotating during detachment, an operator can easily contact the rotating fan to cause injury, so that the blowing and sucking machine may have certain potential safety hazards and does not meet the safety requirements.

Disclosure of Invention

In view of the above, there is a need for a power tool with a brake control circuit to reduce fan down time for safety.

An electric tool comprises a main body, a motor, a fan, a working accessory and a brake control circuit, wherein the motor and the fan are arranged in the main body, the fan is driven by the motor to rotate, the working accessory is detachably connected to the main body, the brake control circuit comprises a control switch and a winding assembly, the control switch and the motor are electrically connected to form a running loop and a brake loop, and the winding assembly is electrically connected between the control switch and the motor to store energy in the running loop and generate counter electromotive force in the brake loop to brake the motor to stop driving the fan.

In one embodiment, the control switch comprises a first switch assembly comprising a first activation switch and a first brake switch and a second switch assembly comprising a second activation switch and a second brake switch; the first starting switch, the second starting switch and the motor are electrically connected to form the running loop, and the first brake switch, the second brake switch and the motor are electrically connected to form the brake loop.

In one embodiment, the first switch component comprises a first common terminal, a first selection terminal and a second selection terminal for selecting the first common terminal, and the second switch component comprises a second common terminal, a third selection terminal and a fourth selection terminal for selecting the second common terminal; the motor comprises a first end and a second end which are connected with two ends of a power supply; the first selection end is electrically connected with the first end of the motor, and the second selection end is electrically connected with the third selection end and is simultaneously electrically connected with the second end of the motor; the fourth selection terminal is electrically connected with the power supply, and the winding assembly is electrically connected between the first common terminal and the second common terminal.

In one embodiment, the winding assembly includes a first winding connected in series between the power source and the first terminal and a second winding connected in series between the first common terminal and the second common terminal.

In one embodiment, the winding assembly includes a first winding and a second winding connected in series between the first common terminal and the second common terminal.

In one embodiment, the first switching assembly and the second switching assembly are controlled synchronously or asynchronously.

In one embodiment, the brake control circuit further comprises an activation switch electrically connected between the first end of the motor and the power source.

In one embodiment, the electric tool is a blowing and sucking machine, and the working accessory is a blowing/sucking pipe detachably arranged on the main body.

In the electric tool, the brake control circuit is used for braking when the motor stops, so that the rotation time of the fan is shortened, the fan stops rotating after the working accessory is detached from the main body, and the personal safety of an operator is guaranteed.

Drawings

FIG. 1 is a circuit diagram of a brake control circuit according to a first embodiment of the present invention;

fig. 2 is a circuit diagram of a brake control circuit according to a second embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, in the preferred embodiment of the present invention, the power tool includes a main body, a motor 10, a fan (not shown), working accessories, and a brake control circuit 20. The motor 10 and the fan are both disposed in the main body, and the fan is driven by the motor 10 to rotate at a high speed and generate a blowing and sucking air flow. The working accessory is detachably connected to the main body, and the brake control circuit 20 is electrically connected with the motor 10 and is used for braking when the motor 10 stops rotating so as to shorten the rotating time of the fan driven by the motor 10, ensure that the fan stops rotating after the working accessory is detached from the main body, and ensure the personal safety of an operator.

In this embodiment, the power tool is a suction blower and the working attachment is a blowpipe and/or suction pipe removably attached to the body. It is understood that in other embodiments, the power tool may be other tools, and the working accessory may also be other accessories that can be detachably disposed, and is not limited herein.

Specifically, the brake control circuit 20 includes a control switch 21 and a winding assembly. The control switch 21 is electrically connected to the motor 10, and forms a running circuit for starting the motor 10 and a braking circuit for braking the motor 10. The winding assembly is electrically connected between the control switch 21 and the motor 10, and stores energy in a run circuit and generates a back electromotive force in a braking circuit, thereby performing braking of the motor 10.

The control switch 21 includes a first switch assembly 211 and a second switch assembly 212, the first switch assembly 211 including a first actuating switch and a first braking switch, and the second switch assembly 212 including a second actuating switch and a second braking switch. The first starting switch, the second starting switch and the motor 10 are electrically connected to form an operation loop, and the first brake switch, the second brake switch and the motor 10 are electrically connected to form a brake loop.

The first switch element 211 includes a first common terminal S1, a first selection terminal K1 for selecting the first common terminal S1, and a second selection terminal K2, and the second switch element 212 includes a second common terminal S2, a third selection terminal K3 for selecting the second common terminal S2, and a fourth selection terminal K4. The motor 10 includes a first end M1 and a second end M2 electrically connected to both ends of the power source 30, a first selection end K1 is electrically connected to the first end M1 of the motor 10, a second selection end K2 is electrically connected to a third selection end K3 and to the third selection end K3 and to the second end M2 of the motor 10, and a fourth selection end K4 is electrically connected to the power source 30.

In this embodiment, the first switch assembly 211 and the second switch assembly 212 are synchronously controlled double-pole double-throw switches. It will be appreciated that in other embodiments, the first and second switch assemblies 211 and 212 are single pole double throw switches, respectively, which may be controlled synchronously or asynchronously.

The winding assembly is electrically connected between the first common terminal S1 and the second common terminal S2 for storing energy in the operating circuit and generating a back emf in the braking circuit to brake the motor 10.

In one embodiment, the winding assembly includes a first winding 231 and a second winding 232. The first winding 231 is connected in series between the power source 30 and the first end M1 of the motor 10, and the second winding 232 is connected in series between the first common terminal S1 and the second common terminal S2. When the first common terminal S1 selects the second selection terminal K2 and the second common terminal S2 selects the fourth selection terminal K4, the power source 30, the first winding 231, the first switching element 211, the second switching element 212, the second winding 232, and the motor 10 form a running loop. When the first common terminal S1 selects the first selection terminal K1 and the second common terminal S2 selects the third selection terminal K3, the motor 10 is disconnected from the power source 30, the first switch element 211, the second switch element 212, the second winding 232 and the motor 10 form a braking circuit, and the second winding 232 generates a back electromotive force to generate a reverse current for braking the motor 10.

In another embodiment, the first and

second windings

231 and 232 are both connected in series between the first and second common terminals S1 and S2. When the first common terminal S1 selects the second selection terminal K2 and the second common terminal S2 selects the fourth selection terminal K4, the power source 30, the first winding 231, the first switching element 211, the second switching element 212, the second winding 232, and the motor 10 form a running loop. When the first common terminal S1 selects the first selection terminal K1 and the second common terminal S2 selects the third selection terminal K3, the motor 10 is disconnected from the power source 30, the first winding 231, the first switch element 211, the second switch element 212, the second winding 232 and the motor 10 form a braking circuit, and the first winding 231 and the second winding 232 generate back electromotive force to generate a reverse current of the braking motor 10.

Further, the brake control circuit 20 further includes a start switch 25, and the start switch 25 is electrically connected between the first end M1 of the motor 10 and the power supply 30.

In the electric tool of the invention, the brake control circuit 20 is used for braking when the motor 10 stops, thereby shortening the rotation time of the fan, ensuring that the fan stops rotating after the working accessory is detached from the main body and ensuring the personal safety of an operator.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An electric power tool characterized in that: the motor and the fan are arranged in the main body, the fan is driven by the motor to rotate, the working accessory is detachably connected to the main body, the brake control circuit comprises a control switch and a winding assembly, the control switch and the motor are electrically connected to form a running loop and a brake loop, and the winding assembly is electrically connected to the control switch and the motor to store energy in the running loop and generate counter electromotive force in the brake loop to brake the motor to stop driving the fan;

the control switch comprises a first switch component and a second switch component, the first switch component comprises a first public end, a first selection end and a second selection end, the first selection end and the second selection end are used for selecting the first public end, and the second switch component comprises a second public end, a third selection end and a fourth selection end, the third selection end and the fourth selection end are used for selecting the second public end; the winding assembly comprises a first winding and a second winding;

when the first common terminal selects the first selection terminal and the second common terminal selects the third selection terminal, the motor is disconnected from a power supply, the first switch component, the second winding or the first winding and the second winding and the motor form a brake loop, and the second winding or the first winding and the second winding generate back electromotive force to form a reverse current for braking the motor.

2. The power tool of claim 1, wherein: the first switch assembly comprises a first starting switch and a first braking switch, and the second switch assembly comprises a second starting switch and a second braking switch; the first starting switch, the second starting switch and the motor are electrically connected to form the running loop, and the first brake switch, the second brake switch and the motor are electrically connected to form the brake loop.

3. The power tool of claim 1, wherein: the motor comprises a first end and a second end which are electrically connected with two ends of a power supply; the first selection end is electrically connected with the first end of the motor, and the second selection end is electrically connected with the third selection end and is simultaneously electrically connected with the second end of the motor; the fourth select terminal is electrically connected to the power supply.

4. The power tool of claim 3, wherein: the first winding is connected in series between the power supply and the first terminal, and the second winding is connected in series between the first common terminal and the second common terminal.

5. The power tool of claim 3, wherein: the first winding and the second winding are connected in series between the first common terminal and the second common terminal.

6. The power tool of any one of claims 1-5, wherein: the first switch assembly and the second switch assembly are controlled synchronously or asynchronously.

7. The power tool of claim 5, wherein: the brake control circuit further includes a start switch electrically connected between the first end of the motor and the power source.

8. The power tool of claim 1, wherein: the electric tool is a blowing and sucking machine, and the working accessory is a blowing/sucking pipe detachably arranged on the main body.