CN215749004U - Hand-held electric tool - Google Patents

Abstract

The utility model belongs to the technical field of electric tools and discloses a handheld electric tool. The electric tool comprises an electric tool body, a speed regulator box and a constant-power speed regulator; the electric tool body comprises a shell, a motor and a fan, wherein the motor is arranged in the shell, and the fan is connected with a rotating shaft of the motor; the casing is provided with a first air inlet at the bottom of a rotating shaft close to the motor, an air outlet is further arranged on the casing, a speed regulator box used for installing a constant-power speed regulator is arranged on one side of the casing in the circumferential direction of the rotating shaft of the motor, a second air inlet is formed in the speed regulator box, and the first air inlet and the second air inlet are communicated with the air outlet. The heat dissipation effect of the handheld electric tool is improved and the service life of the electric tool is prolonged by utilizing the air from the first air inlet and the second air inlet to dissipate heat of the motor and the constant-power speed regulator respectively.

Description

Hand-held electric tool

Technical Field

The utility model relates to the technical field of electric tools, in particular to a handheld electric tool.

Background

The electric tool is a hand-held or movable mechanical tool which takes a motor or an electromagnet as power and drives a working head to work through a transmission mechanism. The hand-held electric tool has the characteristics of light structure, small volume, light weight, small vibration, low noise, flexible operation, convenient control and operation, convenient carrying and use, firmness, durability and the like, can greatly reduce the labor intensity, improve the working efficiency, realize the mechanization of manual operation, and thus is widely applied to the fields of buildings, house decoration, automobiles, machinery, electric power, bridges, gardening and the like, and enters families in a large quantity.

In order to ensure the service life of the electric tool, the motor in the electric tool is protected from overpower and is fully utilized. For this purpose, the armature current is kept at the desired value for a long time when the electric motor is operated at different rotational speeds. On one hand, the purpose is to prevent the motor from being overheated due to the increase of current and reducing the service life of the motor when the rotating speed of the electric tool is reduced at a high load; on the other hand, when the motor cannot be fully utilized in order to operate the electric tool under low load, the high-frequency vibration caused by overhigh rotating speed of the motor can not damage the internal parts of the tool. Therefore, for reasonable use of the motor, the motor is guaranteed to operate under the rated current for a long time without change. The constant power speed regulator is used for ensuring the constant power load operation of the motor, and the plate constant power of the motor is equal to the power required by the load, so that the armature current is generally unchanged no matter what rotating speed the motor operates at, the motor is reasonably utilized, and the constant power requirement of the load is also met.

Most of existing hand-held electric tools do not use a constant power speed regulator, even if the electric tools are provided with the constant power speed regulator, the constant power speed regulator is also mostly arranged at the axial tail end of the motor and shares the same air inlet with the motor, so that the axial size of the motor is increased, the electric tools are heavy and heavy integrally, the temperature of airflow after the constant power speed regulator is cooled is increased, the heat dissipation effect of the motor is reduced, the motor is overheated, and the service life of the electric tools is shortened.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a handheld electric tool which is good in heat dissipation effect and long in service life.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the hand-held electric tool comprises an electric tool body, a speed regulator box and a constant-power speed regulator; the electric tool body comprises a shell, a motor and a fan, wherein the motor is arranged in the shell, and the fan is connected with a rotating shaft of the motor; the bottom of the shell, which is close to the rotating shaft of the motor, is provided with a first air inlet, and the shell is also provided with an air outlet; the casing is provided with a speed regulator box for accommodating the constant-power speed regulator along one circumferential side of the rotating shaft of the motor, the speed regulator box is provided with a second air inlet, and the first air inlet and the second air inlet are both communicated with the air outlet.

Optionally, the air inlet direction of the first air inlet and the air inlet direction of the second air inlet are both parallel to the axial direction of the rotating shaft of the motor.

Optionally, the speed governor box includes a housing and a protective cover, two ends of the housing are respectively provided with a first opening and a second opening, the first opening is connected with a side wall of the electric tool body, and the protective cover is connected to the second opening and configured to be capable of opening or closing the second opening.

Optionally, the second air inlet is disposed on at least one of the housing and the protective cover.

Optionally, the cover is hinged to the housing.

Optionally, the first air inlet and the second air inlet are both of a grid structure.

Optionally, the governor housing and the electric tool body are integrally formed.

Optionally, the electric tool body includes a housing, and the first air inlet and the air outlet are both disposed on the housing.

Optionally, the electric tool body further includes a wind blocking ring, the wind blocking ring is installed between the fan and the motor rotor and is close to the wind outlet, and the wind blocking ring is used for guiding the airflow out of the housing.

Optionally, the power tool body further comprises a first grip and a second grip; the first handle is parallel to the axial direction of the rotating shaft of the motor and is connected with the shell; the second handle is connected to the casing, and the extending direction of the second handle is perpendicular to the axial direction of the rotating shaft of the motor.

Compared with the prior art, the utility model has the beneficial effects that:

according to the handheld electric tool provided by the utility model, the first air inlet is formed in the bottom of the rotating shaft of the motor, the speed regulator box is arranged on one side of the periphery of the electric tool body, and the second air inlet is formed in the speed regulator box, so that cooling air flows respectively enter from the first air inlet and the second air inlet and respectively dissipate heat of the motor in the electric tool body and the constant-power speed regulator in the speed regulator box. Compared with the prior art, the handheld electric tool provided by the utility model can be provided with the constant-power speed regulator to ensure the constant-power operation of the electric tool and prolong the service life; the speed regulator box is arranged in the circumferential direction of the rotating shaft of the motor, so that the axial size of the electric tool can be effectively reduced, the structure of the electric tool is more compact, and the electric tool is convenient to use; and first air intake and second air intake independently set up each other not to influence, dispel the heat to motor and constant power speed regulator respectively, and the radiating effect is better, has prolonged electric tool's life greatly.

Drawings

FIG. 1 is an isometric view of a hand held power tool provided by an embodiment of the present invention;

FIG. 2 is an exploded view of a hand held power tool provided by an embodiment of the present invention;

fig. 3 is a cross-sectional view of a hand held power tool provided by an embodiment of the present invention.

In the figure:

100. an electric tool body; 110. a first air inlet; 130. a housing; 131. an intermediate cover; 132. a front housing; 140. an electric motor; 141. a rotor; 142. a stator; 150. a fan; 160. a wind-shield ring; 171. a first grip; 172. a second grip;

200. a speed governor box; 210. a second air inlet; 220. a housing; 230. a protective cover; 240. a third opening;

300. a constant power speed regulator.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The preferred embodiments of the hand-held power tool of the present invention will be described with reference to the accompanying drawings. In an embodiment of the utility model, the hand-held power tool is in particular a hand-held electric chain saw. Further, the type of the hand-held electric tool is not limited to the hand-held electric chain saw, and may be, for example, an electric hammer, an electric drill, a grass trimmer, an angle grinder, or the like.

As shown in fig. 1, the hand-held power tool of the present embodiment includes a power tool body 100, a governor housing 200, and a constant power governor 300. The electric tool body 100 includes a housing 130, a motor 140, and a fan 150, the motor 140 is installed inside the housing 130, the fan 150 is connected to a rotating shaft of the motor 140, the housing 130 is provided with a first air inlet 110 at a bottom of the rotating shaft of the motor 140, the housing 130 is further provided with an air outlet, the housing 130 is provided with a governor box 200 accommodating the constant power governor 300 at one circumferential side of the rotating shaft of the motor, and the governor box 200 is provided with a second air inlet 210. The first air inlet 110 is communicated with the second air inlet 210, and is communicated with the air outlet, which together form a cooling air flow channel inside the hand-held electric tool. Specifically, the cooling airflow path includes a first cooling airflow path for cooling motor 140 and a second cooling airflow path for cooling constant power governor 300. The first cooling airflow channel is formed by the first intake vent 110, the cavity inside the housing 130, and the air outlet, and the second cooling airflow channel is formed by the second intake vent 210, the cavity inside the housing 130, and the air outlet.

The first air inlet 110 is arranged at the bottom of the rotating shaft of the motor 140, and the second air inlet 210 is arranged on the speed regulator box 200 at one side of the circumferential direction of the rotating shaft of the motor 140, so that cooling air flows respectively enter from the first air inlet 110 and the second air inlet 210, the heat of the motor 140 of the electric tool body 100 and the constant-power speed regulator 300 in the speed regulator box 200 is respectively dissipated, the cooled air flows out of the electric tool body 100 through the air outlet, independent heat dissipation of the motor 140 and the constant-power speed regulator 300 is realized, and the heat dissipation effect is better. Meanwhile, the governor housing 200 is disposed on one side of the casing 130 along the circumferential direction of the rotation shaft of the motor 140, so that the axial dimension of the electric tool can be effectively reduced, and the electric tool is more compact in structure and more convenient to use.

Further, the air inlet direction of the first air inlet 110 and the air inlet direction of the second air inlet 210 are both parallel to the axial direction of the rotating shaft of the motor 140. The structural arrangement ensures that cooling airflow can radiate heat along the axial direction of the rotating shaft of the motor 140, so that the cooling airflow can more smoothly circulate in the first airflow channel and the second airflow channel; simultaneously, the air current parallel after two strands of coolings converges for the air current flow direction in the electric tool body 100 is stable, has ensured the stability, smooth and easy of air inlet and air-out, and difficult emergence blocking phenomenon.

In this embodiment, the first intake vent 110 and the second intake vent 210 are both of a grid structure, but not limited to the grid structure, and may also be a mesh structure or other structures with holes. In addition, the first air inlet 110 and the second air inlet 210 may be formed as through holes without any blocking portions, and protective screens may be disposed thereon. Therefore, the grille or the filter screen at the air inlet can well prevent chips or sundries and the like from entering the electric tool, and the safe operation of the electric tool is ensured.

Referring to fig. 2, the governor housing 200 is composed of a housing 220 and a cover 230, the housing 220 is a structure with two open ends, the two ends of the housing are respectively provided with a first opening and a second opening, the first opening is connected with a side wall of the electric tool body 100, and the cover 230 is connected with the second opening and is configured to be capable of opening or closing the second opening. Therefore, the second air inlet 210, the first opening, the cavity inside the electric tool body 100, and the air outlet form a second cooling air flow channel for cooling the constant power speed governor 300. Optionally, the protective cover 230 is hinged to the housing 220, the protective cover 230 is used for protecting the constant-power governor 300 in the governor box 200 when closed, and meanwhile, when the constant-power governor 300 fails, the protective cover 230 can be conveniently opened, so that maintenance or replacement of the constant-power governor 300 is completed; and, the protecting cover 230 is fixed on the housing 220 by the screw when being closed, so as to improve the stability and the tightness of the connection, so as to better protect the constant power governor 300.

In this embodiment, the governor housing 200 and the power tool body 100 are integrally formed. Specifically, the housing 220 and the electric tool body 100 are integrally formed, and the integral forming mode simplifies the installation process of the handheld electric tool, shortens the production and processing time and improves the production efficiency. The governor housing 200 and the electric tool body 100 may be connected by other connection means, such as screw connection, welding, or the like.

The governor box 200 is further provided with a third opening 240, and the third opening 240 is used for accommodating a gear switch of the constant power governor 300. Alternatively, the third opening 240 and the second air inlet 210 are respectively disposed on different wall surfaces of the governor housing 200, and they do not interfere with each other. The second intake vent 210 is disposed on at least one of the housing 220 and the protective cover 230, and in this embodiment, the second intake vent 210 is disposed on the housing 230, and the third opening 240 is disposed on the protective cover 230.

Alternatively, with continued reference to fig. 2, the power tool body 100 includes a housing 130, and the first air inlet 110 and the air outlet are both disposed on the housing 130. The electric tool further includes an intermediate cover 131 and a front case 132, the intermediate cover 131 is located between the housing 130 and the front case 132, the intermediate cover 131 is used for fixing components inside the electric tool body 100, and the front case 132 is used for connecting with the housing 130 to form a cavity inside the electric tool body 100.

In this embodiment, the power tool body further includes a motor 140, a fan 150, and a wind deflector 160, and a constant power governor 300 is connected to the motor 140 to control the constant power load operation of the motor 140. The motor 140 is composed of a rotor 141 and a stator 142. The rotor 141 is composed of a rotor core, a rotor winding, a rotating shaft, a bearing and the like, wherein the rotor core is used as a part of a magnetic circuit of the motor, and the rotor winding is arranged in an iron core groove; the rotor winding cuts the stator rotating magnetic field to generate induced electromotive force and current, and electromagnetic torque is formed to rotate the motor; the rotating shaft is used for mounting the rotor and extending out of the front shell 132 for driving the working head to rotate, specifically, the working head can be a chain saw, and can also be a grinding sheet, a polishing sheet or a drill bit and the like; the bearing is installed at the bottom of the rotation shaft of the rotor 141 to fix the rotor 141 to the housing 130. In this embodiment, the stator 142 includes a stator core, a stator winding, and a base, where the stator core is used to embed the stator winding, and the stator winding is energized with current to generate a rotating magnetic field. Preferably, the stator core and the rotor core are both made of silicon steel.

Specifically, the stator 142 is fixed to the bottom of the casing 130, and in this embodiment, a screw hole is formed in the bottom casing 130 along the axial direction of the rotating shaft of the motor 140, and the stator 142 is fixed in the casing 130 by a screw fitting the screw hole. The top of the rotating shaft of the rotor 141 is fitted with a through hole in the middle cover 131, and the bearing at the bottom of the rotating shaft of the rotor 141 is fitted with a groove at the bottom of the housing 130. Two fixing screws for fixing the bearing of the motor rotor 141 are provided at the bottom of the housing 130 in a direction perpendicular to the axial direction of the rotating shaft of the motor 140; one end of the rotor 141 of the motor is installed in the bearing, a groove is provided in the axial bottom of the rotating shaft of the motor 140, the groove is installed in cooperation with a protruding part on the inner wall of the bottom of the casing 130, the other end of the rotating shaft of the motor 140 is installed in a through hole of the front casing 132, and is fixedly installed by adopting another bearing to connect the rotor 141 and the electric tool body 100, so that the low-resistance rotation of the rotor is ensured.

In this embodiment, the fan 150 is mounted on the top of the rotating shaft of the rotor 141, fixed on the rotating shaft of the rotor 141, and configured to rotate together with the rotor 141. The wind blocking ring 160 is installed between the fan 150 and the rotor core of the rotor 141 and is close to the air outlet, and the wind blocking ring 160 is hermetically connected with the inner wall of the casing 130, so that the cooling air flow from the motor 140 and the speed governor box 200 passes through and is guided to the air outlet by the wind blocking ring to be discharged outwards, thereby playing a role of guiding air and being beneficial to discharging the cooled air flow. Under the above structure, the rotor 141 drives the fan 150 to rotate when rotating, negative pressure is generated inside the housing 130 when the fan 150 rotates, cooling air flows enter from the first air inlet 110 and the second air inlet 210 respectively in two paths, and the cooling air flow of the first air inlet 110 enters the motor 140 from bottom to top to cool the motor 140; the cooling air flow of the second air inlet 210 enters the speed regulator box 200 to cool the constant power speed regulator 300, and the two cooled air flows are converged to the wind shielding ring 160 and flow out of the air outlet under the guidance of the wind shielding ring 160. Therefore, two different cooling air flows are respectively introduced into the two independently arranged air inlets, and are not mutually influenced, so that the two cooling air flows respectively dissipate heat of the motor 140 and the constant-power speed regulator 300, and a better heat dissipation effect is obtained.

In a preferred embodiment, the power tool body 100 is further provided with a handle, and the handle is used for an operator to operate the hand-held power tool in a hand-held manner, so as to conveniently control the hand-held power tool to perform work. Further, the grip comprises a first grip 171 and a second grip 172, wherein the first grip 171 is connected to the housing 130 along an axial direction parallel to the rotation axis of the motor 140; the second handle 172 is connected to the housing 130, and the extending direction of the second handle 172 is perpendicular to the axial direction of the rotating shaft of the motor 140. Specifically, the first grip 171 and the second grip 172 are both disposed on the housing 130, and the first grip 171 and the second grip 172 may be integrally formed with the housing 130 or detachably connected thereto. Preferably, the second grip 172 is provided with a switch of the hand-held power tool. When the hand-held electric tool is used, one hand holds the first grip 171, the other hand holds the second grip 172, such that one grip is used for applying force to the electric tool to operate the working head for working, such as cutting, polishing, drilling and the like, and the other grip is used for stabilizing the electric tool. Therefore, the electric tool can be conveniently operated, and the stable work of the electric tool can be ensured.

Further, as shown in fig. 3, the casing 130 is approximately cylindrical in shape, and is made of non-metal materials, such as glass fiber reinforced nylon, engineering plastics, or halogen-free flame retardant heat conductive materials.

In the handheld electric tool provided by this embodiment, the governor box 200 is disposed on the housing 130, the constant power governor 300 is disposed in the governor box 200, and the constant power governor 300 is connected to the motor 140 to control the constant power load operation of the motor 140, so that the working power of the motor 140 is equal to the power required by the load, and no matter what rotational speed the motor 140 operates at, the current in the motor 140 is generally unchanged, the motor 140 is reasonably utilized, and the constant power requirement of the load can also be satisfied.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the utility model. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (10)

1. A hand-held electric tool, characterized by comprising an electric tool body (100), a governor housing (200), and a constant power governor (300);

the electric tool body (100) comprises a machine shell (130), an electric motor (140) and a fan (150), wherein the electric motor (140) is arranged inside the machine shell (130), and the fan (150) is connected with a rotating shaft of the electric motor (140); a first air inlet (110) is formed in the bottom of the shell (130) close to the rotating shaft of the motor (140), and an air outlet is formed in the shell (130); the speed regulator box (200) used for containing the constant-power speed regulator (300) is arranged on one side of the circumferential direction of the rotating shaft of the motor (140) of the shell (130), the speed regulator box (200) is provided with a second air inlet (210), and the first air inlet (110) and the second air inlet (210) are communicated with the air outlet.

2. The hand-held power tool according to claim 1, wherein the air inlet direction of the first air inlet (110) and the air inlet direction of the second air inlet (210) are both parallel to the axial direction of the rotating shaft of the motor (140).

3. The hand-held power tool according to claim 1, wherein the governor housing (200) includes a housing (220) and a cover (230), the housing (220) having a first opening and a second opening at both ends thereof, respectively, the first opening being connected to a side wall of the housing case (130), the cover (230) being connected to the second opening and configured to be capable of opening or closing the second opening.

4. The hand-held power tool according to claim 3, wherein the second air inlet (210) is provided in at least one of the housing (220) and the cover (230).

5. The hand held power tool according to claim 3, wherein the cover (230) is hinged to the housing (220).

6. The hand-held power tool according to claim 1, wherein the first intake vent (110) and the second intake vent (210) are each of a grill structure.

7. The hand held power tool according to claim 1, wherein the governor housing (200) is of an integrally formed construction with the housing (130).

8. The hand held power tool according to claim 1, wherein the power tool body (100) further comprises a wind deflector (160), the wind deflector (160) being mounted between the fan (150) and the motor (140) rotor and adjacent to the air outlet, the wind deflector (160) being configured to direct the air flow out of the housing (130).

9. The hand-held power tool according to claim 8, wherein the air outlet is provided at a position on one side of the housing (130) in the circumferential direction of the rotation shaft of the motor (140) and close to the fan (150).

10. The hand-held power tool according to claim 8, wherein the power tool body (100) further comprises a first grip (171) and a second grip (172); the first grip (171) is connected to the housing (130) in an axial direction parallel to a rotation axis of the motor (140); the second handle (172) is connected to the housing (130), and the extending direction of the second handle (172) is perpendicular to the axial direction of the rotating shaft of the motor (140).

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