CN110962016B

CN110962016B - Angle grinder

Info

Publication number: CN110962016B
Application number: CN201811161412.8A
Authority: CN
Inventors: 张响亮; 吉绍山; 马建英
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2022-04-15
Anticipated expiration: 2038-09-30
Also published as: CN110962016A

Abstract

The invention relates to an angle grinder, comprising: a housing; the motor is arranged in the shell and is provided with an output shaft, and the shell of the motor is provided with an air inlet hole and an air outlet hole; the transmission mechanism is connected with the output shaft and is driven by the output shaft to rotate; the working head is connected with the transmission mechanism and is driven by the transmission mechanism to rotate; the holding part is connected with the shell, the holding part and the shell are arranged at an angle, and the holding part is provided with a first air inlet. Wherein, the shell is provided with a second air inlet; the shell is provided with an air outlet at a position close to the air outlet; the casing is internally provided with a first air inlet, flows through the holding part, enters the motor through the air inlet hole, flows out from the air outlet hole, and flows out from the first heat dissipation air duct of air exhaust from the air outlet, and flows out from the second air inlet, enters the motor through the air inlet hole, flows out from the air outlet hole, and flows out from the second heat dissipation air duct of air exhaust from the air outlet. The angle grinder comprises at least two radiating air channels, and the integral radiating and cooling effect is improved.

Description

Angle grinder

Technical Field

The invention relates to the technical field of electric tools, in particular to an angle grinder.

Background

An angle grinder (also called a grinder or a disc grinder) is a hand-held electric tool for cutting and grinding glass fiber reinforced plastics, and is mainly used for cutting, grinding and brushing metal and stone materials.

The traditional angle grinder cools the handle firstly by air intake from one end of the handle, then guides the air to the tail end of the motor, passes through the motor and finally exhausts the air from the front end of the motor, thereby cooling and dissipating the heat of the handle and the motor.

In implementing the conventional technique, the applicant found that: the cooling effect of the traditional angle grinder cooling mode is poor.

Disclosure of Invention

Therefore, it is necessary to provide an angle grinder aiming at the problem of poor cooling effect of the traditional angle grinder cooling method.

An angle grinder, comprising: the motor is arranged in the shell and is provided with an output shaft, and the shell of the motor is provided with an air inlet and an air outlet; the transmission mechanism is connected with the output shaft and is driven by the output shaft; the working head is driven by the output shaft to rotate through the transmission mechanism; the holding part is connected with the shell, the holding part and the shell are arranged at an angle, and the holding part is provided with a first air inlet; the shell is provided with a second air inlet; the shell is provided with an air outlet at a position close to the air outlet; the air inlet of the first air inlet flows through the holding part and enters the motor through the first air inlet hole and the second air inlet hole, flows out of the air outlet hole and enters the motor through the first heat dissipation air channel for air exhaust of the air outlet, and flows out of the air outlet hole and enters the motor through the first air inlet hole and the second air inlet hole, and flows out of the air outlet hole and exits from the air outlet hole and exhausts through the air outlet hole.

The technical scheme at least has the following technical effects: the angle grinder is internally provided with a first heat dissipation air duct which is used for supplying air from a first air inlet and exhausting air from an air outlet through the holding part and the motor, and a second heat dissipation air duct which is used for supplying air from a second air inlet and exhausting air from the air outlet through the motor. The two heat dissipation air channels can reduce the temperature in the holding part, can also enhance the cooling effect on the motor, reduce the temperature rise of the motor and improve the overall heat dissipation cooling effect.

In one embodiment, the motor has opposite head and tail ends, the output shaft extends out of the head end, and the air outlet is arranged between the head end and the tail end.

In one embodiment, the air inlet holes include a first air inlet hole and a second air inlet hole, the first air inlet hole is disposed at the head end, and the second air inlet hole is disposed at the tail end.

In one embodiment, an isolation rib plate is arranged between the inner wall of the holding part, the outer wall of the shell of the motor and the inner wall of the shell at a position close to the air outlet, and the isolation rib plate isolates the air outlet from the first air inlet, so that air entering from the first air inlet enters the motor through the first air inlet.

In one embodiment, the second air inlet includes a head end air inlet and a tail end air inlet, the head end air inlet is disposed at a position of the casing close to the head end, and the tail end air inlet is disposed at a position of the casing close to the tail end, and a first heat dissipation air channel entering the motor through the first air inlet hole and entering from the head end air inlet and a second heat dissipation air channel entering the motor through the second air inlet hole are formed.

In one embodiment, the side wall and the end wall of the casing are provided with the tail end air inlet at a position close to the tail end.

In one embodiment, the first air inlet holes and/or the head end air inlet are provided with a protective net.

In one embodiment, a fan is further disposed in the housing of the motor at a position close to the air outlet, and the fan is disposed on the output shaft.

In one embodiment, the holding part is internally provided with electronic components, and at least comprises a circuit board and a switch assembly; the circuit board is provided with a radiating fin, the switch assembly is electrically connected with the circuit board, and the switch assembly further comprises a switch button arranged outside the holding part.

In one embodiment, the holding portion comprises two symmetrical halves, the two halves are provided with the first air inlet, and the air entering from the first air inlet passes through the circuit board.

In one embodiment, the central axis of the grip portion is perpendicular to the axis of the output shaft.

In one embodiment, the motor further comprises a stator disposed in the housing of the motor, and the stator is in interference fit with the housing of the motor.

In one embodiment, the transmission mechanism includes a hollow transmission shaft sleeved on the output shaft.

In one embodiment, two bearings are arranged on the transmission shaft at intervals along the axial direction of the transmission shaft to support the transmission shaft.

In one embodiment, the transmission shaft is further sleeved with a locking ring, the locking ring is provided with a clamping groove, and a locking assembly capable of being matched with the clamping groove is further arranged in the radial direction of the transmission shaft so as to lock the rotation movement of the transmission shaft.

In one embodiment, the locking assembly comprises a lock shaft button, a bayonet lock connected with the lock shaft button and an elastic element sleeved on the bayonet lock; the bayonet lock can overcome the resistance of the elastic piece and is matched with the bayonet lock to lock the rotation of the transmission shaft, and the elastic piece is configured to provide elastic force for resetting the bayonet lock.

Drawings

FIG. 1 is a schematic view of the internal structure of a housing of an angle grinder in accordance with an embodiment of the present invention;

FIG. 2 is a cross-sectional view A-A shown in FIG. 1;

FIG. 3 is a schematic structural diagram of an angle grinder according to an embodiment of the present invention;

FIG. 4 is a schematic view of the inner structure of the holding portion of the angle grinder in accordance with one embodiment of the present invention;

FIG. 5 is a cross-sectional view C-C shown in FIG. 4;

FIG. 6 is a schematic view of another angle structure of the angle grinder according to an embodiment of the present invention.

Wherein: 100. the angle grinder 110, the machine shell 112, the isolation rib plate 114 and the safety shield

120. Motor 122, head end 124, tail end 126, output shaft

128. Fan 129, magnetic ring 130, holding part 132 and circuit board

134. Cooling fin 142, transmission shaft 144, locking ring 146 and clamping groove

150. Working head 160, battery pack 171 and first air inlet

172. Head end air inlet 173, tail end air inlet 176 and air outlet

177. Air outlet 180, locking assembly 182, lock shaft button 184 and elastic piece

186. Latch 190, switch assembly 192, switch button

194. Switch pull rod 196, return spring 198 and switch element

X, central axis Y of the holding part and axis of the output shaft

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

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 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, 3 and 5, an embodiment of the invention provides an angle grinder 100 capable of improving the overall heat dissipation and cooling effect. In this embodiment, the angle grinder 100 includes: a housing 110; a motor 120 disposed in the housing 110 and having an output shaft 126, and a housing of the motor 120 having an air inlet and an air outlet 176; a transmission mechanism connected to the output shaft 126 and driven by the output shaft 126; the working head 150 is driven by the output shaft 126 to rotate through a transmission mechanism; the holding portion 130 is connected to the housing 110, the holding portion 130 is disposed at an angle to the housing 110, and the holding portion 130 has a first air inlet 171. Wherein, the casing 110 is provided with a second air inlet; the casing 110 is provided with an air outlet 177 at a position close to the air outlet 176; the housing 110 is formed with a first heat dissipation air duct formed therein, which is used for supplying air from the first air inlet 171, flows through the holding portion 130, enters the interior of the motor 120 through the air inlet hole, flows out from the air outlet hole 176, and discharges air from the air outlet 177, and a second heat dissipation air duct formed therein, which is used for supplying air from the second air inlet, enters the interior of the motor 120 through the air inlet hole, flows out from the air outlet hole 176, and discharges air from the air outlet 177.

Specifically, the circumferential contour dimension of the gripping portion 130 matches the gripping range of the hand, facilitating long-time hand-held operation by the operator. The grip portion 130 is also provided therein with electronic components and the like for constituting an operating circuit to control the operation of the motor 120. Traditional motor setting is in the portion of gripping, and the during operation motor can produce certain heat, and this heat can transmit for the portion of gripping to when operating personnel uses the angle grinder at handheld portion of gripping, the heat can transmit on operating personnel's the hand, comfort level when the influence operating personnel uses. In this embodiment, the motor 120 is disposed in the casing 110, the holding portion 130 is connected to the casing 110, and the holding portion 130 is disposed at an angle to the casing 110. With this arrangement, by disposing the motor 120 in addition to the grip portion 130, the temperature rise of the grip portion 130 is further reduced, the operation comfort of the operator is improved, the circumferential contour dimension of the grip portion 130 can be reduced, and the operator can grip the grip portion for a long time. The motor 120 is disposed in the housing 110 and close to the working head 150, which can also reduce the output path of the torque of the motor 120 and reduce the loss of the torque in the transmission process. Further, the holding portion 130 is disposed at an angle to the housing 110, which can be understood that the holding portion 130 is neither parallel to nor collinear with the housing 110, and the specific angle is determined according to actual production, so as to facilitate operation of an operator. In other words, the holding portion 130 is disposed at an angle to the housing 110, and it can also be understood that the central axis X of the holding portion 130 is not parallel to the axis Y of the output shaft 126, that is, the central axis X of the holding portion 130 and the axis Y of the output shaft 126 are neither coincident nor parallel. In some specific embodiments, the central axis X of the holding portion 130 is perpendicular to the axis Y of the output shaft 126, the housing 110 and the holding portion 130 are approximately perpendicular to each other in terms of external shape, the angle grinder 100 is gun-shaped as a whole, the structure is more compact in the axial direction of the output shaft 126, and the connection position of the holding portion 130 and the housing 110 is substantially located in the middle of the housing 110, so that the holding operation of a worker is facilitated.

The angle grinder 100 further includes a battery pack 160, and the battery pack 160 is fixedly connected or detachably connected with the holding portion 130 to provide a power source for the operation of the angle grinder 100. The battery pack 160 is provided with a battery or a battery pack composed of a plurality of batteries, and the batteries can be rechargeable batteries or non-rechargeable batteries. Fig. 6 is a schematic view of another angle of the angle grinder 100.

The output shaft 126 of the motor 120 is connected to a transmission mechanism, and the transmission mechanism is connected to the working head 150 to drive the working head 150 to work. The working head 150 may be a cutting blade for cutting, a grinding blade for grinding, a polishing blade for polishing, or the like. In practice, different operating modes are achieved by different working heads 150. The outer side of the working head 150 is fixedly connected with a safety shield 114 in a posture of semi-surrounding the working head 150, and other shields can be additionally arranged according to the working mode to prevent the sputtering of grinding particles and the like, thereby further improving the safety. In this embodiment, a safety guard 114 is disposed outside the working head 150 to serve as a sanding guard, and a cutting guard may be further disposed to improve safety.

Because the electronic components and the motor 120 in the holding portion 130 generate high heat, in order to improve the heat dissipation capability, in this embodiment, the holding portion 130 is provided with the first air inlet 171, the wind entering from the first air inlet 171 can take away the heat generated in the holding portion 130, and then enters the inside of the housing of the motor 120 through the air inlet hole, takes away the heat generated by the motor 120, flows out from the air outlet hole 176, and exhausts air from the air outlet 177, thereby forming a first heat dissipation air duct. Further, the housing 110 is further provided with a second air inlet, air entering from the second air inlet enters the housing of the motor 120 through the air inlet hole, heat generated by the motor 120 can be taken away, flows out of the air outlet hole 176, and is then discharged out of the housing 110 through the air outlet 177 to form a second heat dissipation air duct. Wherein, the number and the shape of the air inlet holes are not limited. On the premise of ensuring the strength of the shell of the motor 120, a plurality of air inlet holes can be arranged, and the shape can be circular, oval, rectangular and the like. The heating source of the motor 120 is a motor core, and the housing of the motor 120 is provided with a plurality of air inlet holes, so that the air entering from the second air inlet can flow through the housing of the motor 120 more, and the cooling and heat dissipation of the motor 120 core are realized. Of course, the wind entering from the second wind inlet can also flow through the outside of the housing of the motor 120, so as to improve the heat dissipation effect. The air outlets 176 may be spaced around the circumferential profile of the housing of the motor 120, or a cylindrical opening may be provided along the circumferential profile of the housing of the motor 120 to form the air outlets 176. The wind flowing through the inside of the housing of the motor 120 is discharged from the wind outlet 176 and directly flows to the wind outlet 177. The air inlet hole, the first air inlet 171, the second air inlet, the air outlet hole, and the air outlet 177 may be holes with a larger area or a plurality of holes with a smaller area, and the external shapes of the holes are not limited as long as the air inlet and the air outlet can be achieved.

The technical scheme at least has the following technical effects: the angle grinder 100 is formed with a first heat dissipation air duct for exhausting air from the air outlet 177 via the holding portion 130 and the motor 120 by feeding air from the first air inlet 171, and a second heat dissipation air duct for exhausting air from the air outlet 177 via the motor 120 by feeding air from the second air inlet. The two heat dissipation air ducts can not only reduce the temperature in the holding part 130, but also enhance the cooling effect on the motor 120, reduce the temperature rise of the motor 120 and improve the overall heat dissipation and cooling effect.

In some embodiments, motor 120 has opposite leading end 122 and trailing end 124, output shaft 126 extends from leading end 122, and air outlet 176 is disposed between leading end 122 and trailing end 124. The head end 122 is closer to the working head 150 than the tail end 124. The air outlet 176 is disposed at a position between the head end 122 and the tail end 124, and is specifically disposed on the housing of the motor 120. In this embodiment, the air outlet 176 is disposed toward the tail end 124 and is far from the working head 150, so as to prevent the exhausted hot air from becoming the working environment of the working head 150.

Further, the air inlet holes include a first air inlet hole and a second air inlet hole, the first air inlet hole is disposed at the head end 122, and the second air inlet hole is disposed at the tail end 124. The shape of the first air inlet hole and the shape of the second air inlet hole can be a combination of a plurality of circular holes or strip-shaped holes, and can also be a single hole with a larger area. The head end 122 is disposed on the first air inlet hole, and the tail end 124 is disposed with the second air inlet hole, so that more air can flow into the inside of the casing of the motor 120, thereby improving the heat dissipation effect.

Further, referring to fig. 1 and 4, a separation rib 112 is disposed between an inner wall of the holding portion 130, an outer wall of the housing of the motor 120, and an inner wall of the housing 110 at a position near the air outlet hole 176, and the separation rib 112 separates the air outlet hole 176 from the first air inlet hole, so that the air entering from the first air inlet 171 enters the interior of the motor 120 through the first air inlet hole. Thus, the heat dissipation path of the first heat dissipation air duct is specifically that air enters from the first air inlet 171, flows through the holding portion 130, enters the motor 120 through the air inlet hole, flows out from the air outlet hole 176, and is exhausted from the air outlet 177. The isolation rib plate 112 is used for guiding the wind from the holding portion 130, and can prevent the wind from the holding portion 130 from directly discharging from the wind outlet 177 through the wind outlet 176, so that more wind from the holding portion 130 enters the interior of the housing of the motor 120 through the first wind inlet via the head end 122 of the motor 120, and then is discharged out of the housing 110, thereby increasing the heat dissipation path of the wind from the holding portion 130, and performing a greater cooling and heat dissipation function of the wind from the holding portion 130.

Further, referring to fig. 1 and 3, the second air inlet includes a head end air inlet 172 and a tail end air inlet 173, the head end air inlet 172 is disposed at a position of the casing 110 near the head end 122, and the tail end air inlet 173 is disposed at a position of the casing 110 near the tail end 122, and a first second heat dissipation air channel is formed for supplying air from the head end air inlet 172 and entering the interior of the motor 120 through the first air inlet hole, and a second heat dissipation air channel is formed for supplying air from the tail end air inlet 173 and entering the interior of the motor 120 through the second air inlet hole. It can be known that the second heat dissipation air duct includes at least two sub-heat dissipation air ducts, and the specific heat dissipation path of the first second heat dissipation air duct is that air enters from the air inlet 172 at the head end, enters the inside of the motor 120 through the first air inlet hole, flows out from the air outlet hole 176, and exhausts from the air outlet 177; the second heat dissipation air duct has a specific heat dissipation path that air enters from the air inlet 173 at the tail end, enters the motor 120 through the second air inlet hole, flows out from the air outlet hole 176, and is discharged from the air outlet 177. The plurality of heat dissipation air ducts can further reduce the temperature rise of the electronic components and the motor 120 in the holding part 130, enhance the overall cooling effect, and avoid the failure of the angle grinder 100 caused by the temperature rise.

Further, referring to fig. 3, near the rear end 124, both the side wall and the end wall of the casing 110 are provided with a rear end air inlet 173. The motor 120 is surrounded by the casing 110 near the rear end 124 of the motor 120, and the casing 110 forms a side wall and an end wall capable of accommodating the rear end 124 of the motor 120, and the side wall and the end wall are provided with a rear end air inlet 173 to increase the amount of air to be supplied and increase the cooling rate.

Further, the first air inlet hole and/or the head end air inlet 172 are/is provided with a protective net. Because the first air inlet hole and the head end air inlet 172 are relatively close to the working head 150, when the working head 150 is in a working state, especially in a sanding condition, a large amount of generated workpiece debris is easily sucked from the head end air inlet 172 and enters the inside of the housing of the motor 120 through the first air inlet hole, so that the operation of the motor 120 is affected. Therefore, a protective net is provided at the first air inlet hole and/or the head end air inlet 172, which can largely prevent the workpiece debris from entering the inside of the housing of the motor 120. The mesh number (the larger the mesh number, the smaller the mesh aperture) of the protective net is generally 60-140, and if the mesh number is too small, the mesh is too large, so that workpiece scraps can easily pass through the mesh, and the effect of preventing the workpiece scraps cannot be achieved; if the mesh number is too large, the mesh is too small, which affects the air intake effect.

Further, referring to fig. 2, a fan 128 is disposed inside the housing of the motor 120 at a position close to the air outlet 176, and the fan 128 is disposed on the output shaft 126. The fan 128 is arranged to enhance the fluidity of the wind, and to axially and radially draw and discharge the wind, which flows through the interior of the housing of the motor 120 from the head end 122 and the tail end 124 of the motor 120 and the grip portion 130, radially discharge the wind from the air outlet 176 and then discharge the wind from the air outlet 177 out of the housing 110. The fan 128 is disposed on the output shaft 126 and driven by the output shaft 126 to rotate, the fan 128 has a plurality of blades, and the extending direction of each blade is parallel to the axis Y direction of the output shaft 126, so as to achieve the purposes of axial air suction and radial air discharge.

In some embodiments, referring to fig. 4, electronic components are disposed within the grip portion 130, including at least the circuit board 132 and the switch assembly 190. The holding portion 130 is provided with a circuit board 132, and the circuit board 132 is provided with a heat sink 134. Specifically, the circuit board 132 is electrically connected to the battery pack 160, the circuit board 132 forms a part of an operating circuit, and the circuit board 132 belongs to an electronic component, and is easy to generate heat and scald when in operation, so that the circuit board 132 is provided with the heat sink 134 to reduce the temperature rise of the circuit board 132. The heat sink 134 may be made of an aluminum alloy, and has good thermal conductivity, so as to dissipate heat from the circuit board 132.

Further, the grip portion 130 is further provided with a switch assembly 190. The switch assembly 190 is electrically connected to the circuit board 132, and the switch assembly 190 is used for controlling the on/off of the working circuit, so as to control the working state of the angle grinder 100. The switch assembly 190 includes a switch knob 192 disposed outside the grip portion 130, a switch rod 194 connected to the switch knob 192 and disposed inside the grip portion 130, a return spring 196 connected to the switch rod 194, and a switch element 198 connected to the switch rod 194 and the return spring 196. Meanwhile, the switch assembly 190 is electrically connected to the motor 120, and particularly, the switch element 198 is electrically connected to the motor 120 to control the operating state of the motor 120.

Further, referring to fig. 3, the grip portion 130 includes two symmetrical halves, and both halves are provided with the first air intake vent 171, and the air entering from the first air intake vent 171 passes through the circuit board 132. The holding portion 130 is generally formed by two symmetrical parts, which facilitates the disassembly and maintenance of the devices in the holding portion 130. As shown in fig. 3, the first air inlets 171 are disposed on the upper and lower sides of the holding portion 130, and the first air inlets 171 are located at the position of the holding portion 130, close to the circuit board 132, so as to ensure that the wind entering from the first air inlets 171 can pass through the circuit board 132, thereby cooling and dissipating the heat of the circuit board 132.

In some embodiments, referring to fig. 4, a magnetic ring 129 is also connected to the motor 120 to suppress high frequency noise. The magnetic ring 129 is arranged between the switch element 198 and the motor 120 and is positioned at the holding part 130 or the position close to the motor 120, and the magnetic ring 129 can play a good role in noise reduction, so that the use performance of the angle grinder 100 is improved, and the comfort level of operators is improved.

Further, the motor 120 further includes a stator disposed within the housing of the motor 120, wherein the stator is in interference fit with the housing of the motor 120. The stator is a stationary component of the motor 120 and is primarily responsible for generating a rotating magnetic field. In order to prevent the stator from rotating when the motor 120 is started or stopped, the stator is in interference fit with the housing of the motor 120, so that the stator is in a relatively static state.

In some embodiments, referring to fig. 1 and 5, the transmission mechanism includes a hollow transmission shaft 142 sleeved on the output shaft 126. The portion of the output shaft 126 extending out of the head end 122 has a certain length, but is not directly connected to the working head 150, but a hollow transmission shaft 142 is sleeved outside the output shaft 126, and the transmission shaft 142 and the output shaft 126 are in interference fit, so that the output shaft 126 can drive the transmission shaft 142 to rotate. So set up, can prevent to change whole motor 120 after output shaft 126 damages, only need change transmission shaft 142 can, reduced cost of maintenance.

Further, two bearings are provided on the transmission shaft 142 at intervals along the axial direction of the transmission shaft 142 to support the transmission shaft 142. On the basis of supporting the transmission shaft 142, the double bearings can further ensure the rotation stability of the transmission shaft 142, reduce the shaking phenomenon of the transmission shaft 142, also ensure the rotation stability of the working head 150 and improve the working accuracy of the working head 150.

Further, the transmission shaft 142 is further sleeved with a locking ring 144, the locking ring 144 is provided with a locking groove 146, and a locking assembly 180 capable of cooperating with the locking groove 146 is further provided in the radial direction of the transmission shaft 142 to lock the rotational movement of the transmission shaft 142. A locking ring 144 having a locking groove 146 is further sleeved outside the transmission shaft 142, the locking ring 144 is located between the two bearings, and the locking ring 144 and the transmission shaft 142 are also configured to be in interference fit. When the working head 150 needs to be replaced, in order to prevent the transmission shaft 142 from being driven to rotate, the locking assembly 180 is firstly matched with the clamping groove 146 to prevent the locking ring 144 from rotating, so that the transmission shaft 142 is prevented from rotating, and then the working head 150 is replaced. The locking assembly 180 can prevent the transmission shaft 142 from rotating when the working head 150 is replaced, thereby facilitating the replacement of the working head 150 and improving the working efficiency.

In some embodiments, the locking assembly 180 includes a lock shaft button 182, a detent 186 connected to the lock shaft button 182, and a resilient member 184 sleeved on the detent 186; the detent 186 is movable against the resistance of the resilient member 184 and cooperates with the detent 146 to lock the rotational movement of the drive shaft 142, the resilient member 184 being configured to provide a resilient force to reset the detent 186.

Specifically, by pressing the shaft locking button 182, the detent 186 is driven to move toward the transmission shaft 142 against the resistance of the elastic member 184 until the detent 186 engages with the detent 146, thereby locking the transmission shaft 142, and the elastic member 184 is in a compressed state. Since the elastic member 184, such as a spring, is disposed between the detent 186 and the latch shaft button 182, the detent 186 is pushed to be reset by the elastic force of the spring when the latch shaft button 182 is not pressed any more.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the 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 angle grinder, comprising:

a machine shell, a first cover plate and a second cover plate,

the motor is arranged in the shell and provided with an output shaft, the motor is provided with a head end and a tail end which are opposite, the output shaft extends out of the head end, the shell of the motor is provided with air inlet holes and air outlet holes, the air inlet holes comprise a first air inlet hole and a second air inlet hole, the first air inlet hole is arranged at the head end, the second air inlet hole is arranged at the tail end, and the air outlet hole is arranged between the head end and the tail end;

the transmission mechanism is connected with the output shaft and is driven by the output shaft;

the working head is driven by the output shaft to rotate through the transmission mechanism;

the holding part is connected with the shell, the holding part and the shell are arranged at an angle, and the holding part is provided with a first air inlet;

the shell is provided with a second air inlet; the shell is provided with an air outlet at a position close to the air outlet; a first heat dissipation air duct which enters air from the first air inlet, flows through the holding part, enters the motor through the first air inlet hole and the second air inlet hole, flows out of the air outlet hole and exhausts air from the air outlet, and a second heat dissipation air duct which enters air from the second air inlet, enters the motor through the first air inlet hole and the second air inlet hole, flows out of the air outlet hole and exhausts air from the air outlet are formed in the shell;

the second air intake includes head end air intake and tail end air intake, the head end air intake is located being close to of casing the position of head end, the tail end air intake is located being close to of casing the position of tail end is formed with certainly head end air intake air, through first fresh air inlet gets into the inside first of motor the second heat dissipation wind channel, and certainly tail end air intake air, through the second fresh air inlet gets into the inside second of motor the second heat dissipation wind channel.

2. The angle grinder according to claim 1, wherein an isolation rib is provided between an inner wall of the grip portion, an outer wall of the housing of the motor, and an inner wall of the housing at a position close to the air outlet, and the isolation rib isolates the air outlet from the first air inlet, so that the air entering from the first air inlet enters the motor through the first air inlet.

3. The angle grinder of claim 1, further comprising a battery pack fixedly or removably connected to the grip portion.

4. The angle grinder of claim 1, wherein the tail end air intake is provided in each of a side wall and an end wall of the housing at a position near the tail end.

5. The angle grinder of claim 1, wherein the first air inlet hole and/or the head end air inlet hole is provided with a protective net.

6. The angle grinder of claim 1, wherein a fan is further provided in the housing of the motor adjacent to the outlet opening, the fan being provided on the output shaft.

7. The angle grinder of claim 1, wherein the grip portion has electronic components therein, including at least a circuit board and a switch assembly; the circuit board is provided with a radiating fin, the switch assembly is electrically connected with the circuit board, and the switch assembly further comprises a switch button arranged outside the holding part.

8. The angle grinder of claim 7, wherein the grip portion includes symmetrical halves each provided with the first air intake port, and the wind entering from the first air intake port passes through the circuit board.

9. The angle grinder of claim 1, wherein a central axis of the grip portion is perpendicular to an axis of the output shaft.

10. The angle grinder of claim 1, wherein the motor further includes a stator disposed within a housing of the motor, the stator being in an interference fit with the housing of the motor.

11. The angle grinder of claim 1, wherein the transmission mechanism includes a hollow transmission shaft sleeved on the output shaft.

12. An angle grinder as claimed in claim 11, wherein two bearings are provided on the drive shaft at intervals in the axial direction of the drive shaft to support the drive shaft.

13. The angle grinder as claimed in claim 11, wherein the transmission shaft is further sleeved with a locking ring, the locking ring is provided with a locking groove, and a locking assembly engageable with the locking groove is further provided in a radial direction of the transmission shaft to lock a rotational movement of the transmission shaft.

14. The angle grinder of claim 13, wherein the locking assembly comprises a lock shaft button, a bayonet pin connected with the lock shaft button, and an elastic member sleeved on the bayonet pin; the bayonet lock can overcome the resistance of the elastic piece and is matched with the bayonet lock to lock the rotation of the transmission shaft, and the elastic piece is configured to provide elastic force for resetting the bayonet lock.