CN113659762A

CN113659762A - Electric tool

Info

Publication number: CN113659762A
Application number: CN202110851378.2A
Authority: CN
Inventors: 余鸿东
Original assignee: Zhejiang Ken Tools Co ltd; Ken Holding Co ltd
Current assignee: Zhejiang Ken Tools Co ltd; Ken Holding Co ltd
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2021-11-16

Abstract

The invention discloses an electric tool, which comprises: the surface of the shell is provided with an air inlet; the motor is arranged inside the shell; the magnetic filter device is magnetic, and is arranged in the shell and positioned on an air channel between the air inlet and the motor. This electric tool utilizes magnetism of magnetic filter device to adsorb the iron powder in the wind channel that gets into in the casing, avoids the iron powder to get into between the stator rotor of motor, causes the air gap intercommunication between stator, the rotor, and then influences the power and the life-span of motor, and with the inside of magnetic filter device setting at the casing, the iron powder in the wind channel that magnetic filter device only inhales in the entering casing, and does not have the adsorption effect to the iron powder in the external environment, improves magnetic filter device's adsorption efficiency.

Description

Electric tool

Technical Field

The present invention relates to an electric power tool.

Background

At present, motors with permanent magnet structures (e.g., brushless motors) have been widely used in power tools. A large amount of iron powder exists in part of working environments of the electric tool, such as angle grinding, cutting and the like, and in addition, the iron powder enters the motor along a cooling air duct of the motor in a motor fan cooling mode. A part of iron powder can be adsorbed on the motor by the permanent magnet, and along with the accumulation of the iron powder, air gap communication between the stator and the rotor can be caused, so that the power and the service life of the motor are influenced; in addition, a part of iron powder can enter a bearing gap, and the service life of the bearing is reduced.

As shown in fig. 1 and 2, in order to prevent the iron powder from entering the inside of the motor, a filter screen 10 is usually disposed at an air inlet 20 of the electric tool, and the smallest aperture of the filter screen has a hundred meshes, which is equivalent to an aperture of 0.25mm, and is still too large in particle size compared with the fine iron powder, which is a little bit longer in time, and the iron powder still has adverse effects; however, if a thinner filter screen is used, the wind resistance of the filter screen is larger, the cooling air intake and the cooling wind speed of the motor are affected, and the cooling effect of the motor is poor. In another mode, an air channel between a stator and a rotor of the motor is closed, so that although the problem of entry of iron powder can be solved, the rotor is difficult to cool, and thus, when the motor works under a heavy load, the temperature of the rotor is sharply increased and exceeds the demagnetization temperature of the permanent magnet, the permanent magnet is demagnetized, and the motor fails.

Disclosure of Invention

The invention aims to overcome the defect that the service life of an electric tool is shortened when iron powder enters the electric tool, and provides the electric tool.

The invention solves the technical problems through the following technical scheme:

a power tool, comprising:

the surface of the shell is provided with an air inlet;

the motor is arranged inside the shell;

the magnetic filter device is magnetic, and is arranged in the shell and positioned on an air channel between the air inlet and the motor.

In this scheme, this electric tool utilizes magnetic filter's magnetism to adsorb the iron powder that gets into in the wind channel of casing, avoids between the iron powder gets into the stator rotor of motor, causes the air gap intercommunication between stator, the rotor, and then reduces the power and the life-span of motor, and with the inside of magnetic filter setting at the casing, the iron powder in the wind channel of magnetic filter only inhaling entering casing, and the iron powder to among the external environment does not have the adsorption, improves magnetic filter's adsorption efficiency.

Preferably, the magnetic filter device includes a first filter screen, the first filter screen covers the air duct, the first filter screen has magnetism, and the first filter screen has a plurality of filtering holes.

In this scheme, adopt above-mentioned structural style for magnetic field evenly distributes in the wind channel, improves absorption efficiency.

Preferably, first filter screen includes frame and wire side, the edge all around of wire side connect in the inner wall of frame, the wire side cover in the wind channel, be equipped with a plurality of on the wire side filter the hole, first filter screen pass through the frame install in the inside of casing, the wire side has magnetism.

In the scheme, the structure is adopted, so that the magnetic field is uniformly distributed in the air duct, and the installation and the fixation of the net surface are facilitated. Preferably, the first screen is a magnetized wire mesh. In other embodiments, the frame may have magnetic properties.

Preferably, the outer surface of the casing has a mounting opening for mounting and dismounting the first filter screen.

In this scheme, adopt above-mentioned structural style, need not to open the casing, just can install and regularly clear up convenient operation to first filter screen through the installing port.

Preferably, the magnetic filter device further includes a second filter screen, the second filter screen has no magnetism, the second filter screen covers the air duct, and the second filter screen is disposed adjacent to the first filter screen and upstream of the first filter screen.

In this scheme, adopt above-mentioned structural style, improve the filter effect.

Preferably, the number of the first filter screens is a plurality, and the first filter screens are arranged at intervals along the length direction of the air duct.

Preferably, the cross section of the casing is a U-shaped groove, and the first filter screen is adapted to and clamped in the U-shaped groove.

In this scheme, adopt above-mentioned structural style, be convenient for first filter screen takes out in the installing port, clears up first filter screen.

Preferably, the two filter screens are filter paper or filter cloth.

Preferably, the number of the holes of the first filter screen and the second filter screen is not more than 100.

In the scheme, the iron powder with a small diameter can be conveniently filtered by adopting the structural form. The mesh count is the number of mesh openings per inch of length.

Preferably, the magnetic filter device includes a magnet, the magnet is annular, and an outer peripheral surface of the magnet abuts against an inner wall of the air duct.

In the scheme, when wind flows through the middle of the magnetic ring, the iron powder is adsorbed by the magnetic ring. In other alternative schemes, a plurality of magnets are arranged on the inner wall of the air duct at intervals, and a magnetic field is formed on the air duct.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The positive progress effects of the invention are as follows: this electric tool utilizes magnetism of magnetic filter device to adsorb the iron powder in the wind channel that gets into in the casing, avoids the iron powder to get into between the stator rotor of motor, causes the air gap intercommunication between stator, the rotor, and then reduces the power and the life-span of motor, and set up magnetic filter device in the inside of casing, the iron powder in the wind channel that magnetic filter device only inhales in the entering casing, and does not have the adsorption effect to the iron powder in the external environment, improves magnetic filter device's adsorption efficiency.

Drawings

Fig. 1 is a schematic structural diagram of an electric tool according to the background art of the present invention.

Fig. 2 is a cross-sectional view taken along line a-a of fig. 1.

Fig. 3 is a schematic structural diagram of an electric tool according to a preferred embodiment of the invention.

Fig. 4 is a cross-sectional view taken along line B-B of fig. 3.

Fig. 5 is an exploded view of the housing and the first screen of fig. 4.

Description of reference numerals:

reference numerals of the background art

Filter screen 10

Air inlet 20

Reference numerals of the invention

Case 1

Air inlet 101

Motor 11

Magnetic filter device 12

First filter screen 121

Frame 1211

Net surface 1212

U-shaped groove 102

Detailed Description

The present invention will be more clearly and completely described below by way of examples and with reference to the accompanying drawings, but the present invention is not limited thereto.

Example 1

As shown in fig. 3 to 5, the present embodiment discloses a power tool including a housing 1, a motor 11, and a magnetic filter device 12. The surface of the machine shell 1 is provided with an air inlet 101, the motor 11 is arranged inside the machine shell 1, the magnetic filter device 12 has magnetism, and the magnetic filter device 12 is arranged inside the machine shell 1 and is positioned on an air channel between the air inlet 101 and the motor 11.

In this embodiment, this electric tool utilizes the magnetism of magnetic filter 12 to adsorb the iron powder that gets into in the wind channel of casing 1, avoid the iron powder to get into between the stator rotor of motor 11, cause the air gap intercommunication between stator, the rotor, and then reduce the power and the life-span of motor 11, and set up magnetic filter 12 in the inside of casing 1, magnetic filter 12 only inhales the iron powder that gets into in the wind channel of casing 1, and the iron powder to in the external environment does not have the adsorption, improve magnetic filter 12's adsorption efficiency.

Wherein, magnetic filter 12 includes first filter screen 121, and first filter screen 121 covers on the wind channel, and first filter screen 121 has magnetism, is equipped with a plurality of filtration pore on first filter screen 121 for magnetic field distributes uniformly in the wind channel, improves adsorption efficiency.

In this embodiment, the first filter screen 121 includes a frame 1211 and a screen surface 1212, the peripheral edge of the screen surface 1212 is connected to the inner wall of the frame 1211, the screen surface 1212 covers the air duct, a plurality of filter holes are formed in the screen surface 1212, the first filter screen 121 is installed inside the casing 1 through the frame 1211, and the screen surface 1212 has magnetism. Preferably, the net surface 1212 is a magnetized iron wire net, which is simple to manufacture and low in cost. In other embodiments, the frame may have magnetic properties and the mesh surface may be non-magnetic; or the frame and the net surface are both magnetic.

Preferably, the outer surface of the cabinet 1 has a mounting opening for mounting and dismounting the first screen 121. When the iron powder on first filter screen 121 of clearance, need not to open casing 1, just can carry out regular clearance, convenient operation to first filter screen 121 through the installing port.

Furthermore, the cross section of the casing 1 is a U-shaped groove 102, and the first filter screen 121 is matched with the U-shaped groove 102 and clamped inside the U-shaped groove 102, so that the first filter screen 121 completely seals the air channel, the filtering effect is improved, the first filter screen 121 can be conveniently installed and detached through the installation opening, and the operation is simple and convenient.

Furthermore, the magnetic filter device 12 further includes a second filter screen (not shown in the figure), the second filter screen has no magnetism, the second filter screen is installed on the air duct, and the second filter screen is disposed adjacent to the first filter screen 121 and located at the upstream of the first filter screen 121, the air firstly removes dust through the second filter screen, and then flows through the first filter screen 121, so as to improve the filtering and iron powder adsorption effects.

On this basis, the quantity of first filter screen 121 is a plurality of, and a plurality of first filter screens 121 set up along the length direction interval in wind channel, improve the filter effect of iron powder. Wherein, the second filter screen is filter paper or filter cloth, is convenient for filter the tiny iron powder of diameter.

Preferably, the mesh number of the first screen 121 and the second screen is not more than 100, which facilitates filtering iron powder with a small diameter. Wherein the number of holes is the number of holes per inch of length.

Example 2

This embodiment is substantially the same as embodiment 1, except that: the magnetic filter device is a magnet which is annular, the outer peripheral surface of the magnet is abutted against the inner wall of the air duct, and a magnetic field is formed on the air duct. When wind flows through the middle of the magnetic ring, the iron powder is adsorbed by the magnetic ring. In other alternative embodiments, a plurality of magnets may be uniformly arranged on the inner wall of the air duct at intervals along the circumferential direction, so as to form a uniform magnetic field on the air duct.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. An electric power tool, characterized in that it comprises:

the surface of the shell is provided with an air inlet;

the motor is arranged inside the shell;

2. The power tool of claim 1, wherein the magnetic filter device comprises a first filter covering the air channel, the first filter having a plurality of filter holes, the first filter being magnetic.

3. The power tool of claim 2, wherein the first filter includes a frame and a mesh surface, a peripheral edge of the mesh surface is connected to an inner wall of the frame, the mesh surface covers the air duct, the mesh surface is provided with a plurality of the filter holes, the first filter is mounted inside the housing through the frame, and the mesh surface has magnetism.

4. The power tool of claim 2, wherein an outer surface of the housing has a mounting opening for mounting and dismounting the first filter screen.

5. The power tool of claim 2, wherein the magnetic filter device further comprises a second filter screen, the second filter screen being non-magnetic, the second filter screen being covered by the air channel, and the second filter screen being disposed adjacent to and upstream of the first filter screen.

6. The power tool of claim 2, wherein the number of the first filter screens is plural, and the plural first filter screens are arranged at intervals along the length direction of the air duct.

7. The power tool of claim 4, wherein the housing has a U-shaped cross-section, and the first filter is adapted to fit into and engage the U-shaped slot.

8. The power tool of claim 5, wherein the two screens are filter paper or filter cloth.

9. The power tool of claim 5, wherein the first and second screens have no more than 100 mesh openings.

10. The power tool of claim 1, wherein the magnetic filter includes a magnet having a ring shape, and an outer circumferential surface of the magnet abuts against an inner wall of the air duct.