WO2020064005A1

WO2020064005A1 - Hand-held power tool

Info

Publication number: WO2020064005A1
Application number: PCT/CN2019/109429
Authority: WO
Inventors: 张响亮; 吉绍山; 马建英
Original assignee: 苏州宝时得电动工具有限公司
Priority date: 2018-09-30
Filing date: 2019-09-30
Publication date: 2020-04-02

Abstract

A hand-held power tool (100), comprising a motor (120) having a motor case and an output shaft (126), and the motor case being provided with an air inlet hole and an air outlet hole (176); a housing, comprising a head housing (110) accommodating the motor and a gripping portion (130) provided at an angle with respect to the head housing (110), the housing being provided with an air inlet and an air outlet (177); and a fan (128), connected to the output shaft (126). The motor case has a head end (122) and a tail end (124) provided opposite each other, the air inlet hole comprises a first air inlet hole (123) provided at the head end (122) and a second air inlet hole (125) provided at the tail end (124), the air outlet hole (176) is provided between the head end (122) and the tail end (124), and the output shaft (126) protrudes from the head end (122). When the fan (128) is driven, by means of the output shaft (126), to rotate, a first heat dissipation air passage in which air enters the interior of the motor case from the first air inlet hole (123) and flows out from the air outlet hole (176) and a second heat dissipation air passage in which air enters the motor case from the second air inlet hole (125) and flows out from the air outlet hole (176) are formed in the motor case, so that air can flow into the motor case through at least two heat dissipation air passages in the hand-held power tool (100), increasing the air inlet amount of the motor case, and improving the heat dissipation effect of the head housing (110) and the motor (120).

Description

Hand-held power tools

This application requires that the application date is September 30, 2018, the application number is 201811161412.8, the invention name is "Angle Grinder", and the application date is September 30, 2018, the application number is 201811158952.0, and the invention name is "Handheld Tool The priority of a Chinese patent application is incorporated herein by reference in its entirety.

Technical field

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

Background technique

Hand-held electric tools are driven by a motor-driven work head. The user grasps work tools that perform cutting, drilling, and grinding on the workpiece. For example, angle grinders, sanders, electric circular saws, etc. require users to hold the tools for operation. . In work, the motor needs to be powered on. Current flows through the winding to generate a magnetic field, which causes the rotor to rotate and output torque. At the same time, the current will also generate a lot of heat in the winding.

Taking the angle grinder as an example, the angle grinder, also known as a grinder or disc grinder, is a hand-held power tool that uses a wheel to cut or grind. It is mainly used to cut, grind, and brush metal and stone. Wait. The traditional angle grinder enters the wind from one end of the handle, first cools the handle, then guides the wind to the end of the motor, passes through the motor, and finally winds out from the front of the motor to cool the handle and the motor.

In addition, in common motors, the fan is installed at one end of the motor. When the tool is running, the cooling air is driven by the fan from one end of the motor to the other end, which makes the cooling air path longer. In the initial stage of the air circuit, the temperature of the cooling air is low, and the part of the motor at this stage has a good cooling effect; at the end of the air path, the temperature of the cooling air is high, and the part of the motor in this stage has a poor cooling effect.

In the process of realizing the traditional technology, the applicant found that the traditional hand-held power tool has a long air path, a single air path, and a small air volume, and the cooling effect of the motor and the whole machine is not good.

Summary of the Invention

Based on this, it is necessary to provide a hand-held power tool for the problem that the cooling effect of the traditional hand-held power tool is not good in cooling.

A hand-held power tool includes a motor, which has a motor casing and an output shaft, and the motor casing is provided with air inlet holes and air outlet holes. The casing includes a head housing that houses the motor, and The holding portion is arranged at an angle, and the casing is provided with an air inlet and an air outlet; a fan is connected to the output shaft; wherein, the motor housing has oppositely arranged head ends and tail ends, and the air inlet hole includes a first An air inlet hole and a second air inlet hole provided at the tail end. The air outlet hole is provided between the head end and the tail end, and the output shaft protrudes from the head end. When the fan is driven to rotate by the output shaft, the inside of the motor housing is formed. There is a first cooling air path entering the motor casing from the first air inlet hole and flowing out of the air outlet hole, and a second cooling air duct entering the motor housing from the second air inlet hole and flowing out of the air outlet hole. road.

The above technical solution has at least the following technical effects: a first heat dissipation air path entering the motor housing from the first air inlet hole, a first heat dissipation airflow from the air outlet hole, and electric power entering from the second air inlet hole are formed in the angle grinder housing. The second heat dissipation air path flowing out of the air outlet inside the casing. The above two cooling air passages increase the amount of air entering the motor casing, and the lengths of the two cooling air passages are relatively short, which prevents the higher temperature cooling air from flowing in the motor, which can not only reduce the inside of the head case. The temperature can also enhance the cooling effect on the motor, reduce the temperature rise of the motor, and improve the overall cooling and cooling effect.

In one embodiment, the air outlet is disposed on the head case near the air outlet.

In one embodiment, the air inlet includes a tail air inlet, and the tail air inlet is located near the tail end of the head shell; a first heat dissipation air duct is formed in the head shell, and the first heat dissipation air duct is inside the motor casing. When the fan is driven to rotate by the output shaft, the first cooling air duct enters the air from the tail air inlet, flows through the second cooling air path, and exhausts the air from the air outlet.

In one embodiment, the air inlet includes a head-end air inlet, and the head-end air inlet is provided near the head end of the head shell; a second heat dissipation air duct is formed in the head shell, and the second heat dissipation air duct and the motor casing When the fan is driven to rotate by the output shaft, the second cooling air duct enters air from the air inlet at the head end, flows through the second cooling air path, and exhausts air from the air outlet.

In one embodiment, the air inlet includes a handle air inlet provided on the holding portion, a third heat dissipation air duct is formed in the casing, the third heat dissipation air duct is in communication with the first heat dissipation air path, and the fan is driven to rotate by the output shaft At this time, the wind entering from the air inlet of the handle flows through the third heat dissipation air duct and enters the motor casing through the first air inlet.

In one embodiment, the air inlet includes a handle air inlet provided on the holding part, a third heat dissipation air duct is formed in the casing, the third heat dissipation air duct is in communication with the second heat dissipation air path, and the fan is driven to rotate by the output shaft At this time, the wind entering from the air inlet of the handle flows into the motor casing through the second air inlet after flowing through the third heat dissipation air duct.

In one embodiment, an electronic component is included in the holding part, including at least a circuit board and a switch assembly; wherein a heat sink is provided on the circuit board, the switch assembly is electrically connected to the circuit board, and the wind entering from the handle air inlet passes through Electronic component.

In one embodiment, the holding portion includes two Huff-type shells, and the handle air inlet is symmetrically disposed on the two Huff-type shells.

In one embodiment, an isolation rib is provided between the inner wall of the holding portion, the outer wall of the motor housing, and the inner wall of the casing. The isolation rib separates the air outlet hole from the first air inlet hole, so that The wind entering the handle air inlet enters the inside of the motor casing through the first air inlet.

In one embodiment, an isolation rib is provided between the inner wall of the holding portion, the outer wall of the motor casing and the inner wall of the casing, and the isolation rib separates the air outlet hole from the second air inlet hole, so that The wind entering the handle air inlet enters the inside of the motor casing through the second air inlet.

In one embodiment, the tail air inlet is disposed on a side wall and / or an end wall of the head shell.

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

In one embodiment, the fan is disposed near the air outlet.

In one embodiment, a working head and a transmission shaft sleeved on the output shaft are further included, and the working head is connected to the transmission shaft.

In one embodiment, two bearings are provided 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 provided with a locking ring, the locking ring is provided with a locking groove, and a locking component that can be matched with the locking groove is also provided in the radial direction of the transmission shaft to lock the rotation of the transmission shaft. motion.

In one embodiment, the locking assembly includes a lock button, a latch connected to the lock button, and an elastic member sleeved on the latch; the latch can overcome the resistance of the elastic member and cooperate with the slot to lock the transmission. With the rotational movement of the shaft, the elastic member is configured to provide an elastic force to reset the bayonet.

In one embodiment, a battery pack mounting portion is provided at an end of the holding portion remote from the head shell; the handheld power tool includes a battery pack removably connected to the battery pack mounting portion, and the battery pack is disposed to extend along the longitudinal axis. The shape is long, and the holding part has a longitudinally extending axis of the holding part. The battery pack has a mounting end mated with the battery pack mounting part and a bottom plane of the battery pack opposite to the mounting end. The angle is set, and the longitudinal axis is perpendicular to the output shaft axis.

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

A hand-held power tool includes: a casing, including a head casing, and a holding portion disposed at an angle of the head casing; a motor, disposed in the head casing, having a motor casing, an output shaft, and a fan; and the motor casing An air inlet is provided on the body; the motor housing has oppositely arranged head ends and tail ends, and the output shaft extends from the head end. The air inlet holes include a first air inlet hole provided at the head end and a second air inlet hole provided at the tail end. The air hole and the fan are arranged between the first air inlet hole and the second air inlet hole, and an air outlet hole is also provided on the motor casing near the fan.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a handheld power tool head shell according to a first embodiment of the present invention; FIG.

FIG. 2 is a schematic structural diagram of a handheld power tool head shell according to a second embodiment of the present invention; FIG.

3 is a schematic structural diagram of a handheld power tool head shell according to a third embodiment of the present invention;

4 is a cross-sectional view taken along A-A shown in FIG. 1;

5 is a schematic structural diagram of a handheld power tool according to an embodiment of the present invention;

6 is a schematic structural diagram of a holding portion of a handheld power tool according to an embodiment of the present invention;

Fig. 7 is a sectional view taken along C-C shown in Fig. 6;

FIG. 8 is a schematic diagram of another angle structure of a hand-held power tool according to an embodiment of the present invention.

FIG. 9 is a schematic perspective view of a state where a casing of a hand-held power tool according to the present invention is separated from a battery pack.

FIG. 10 is a schematic diagram of a motor of a handheld power tool according to the present invention.

FIG. 11 is another schematic perspective view of the motor of the handheld power tool according to the present invention.

FIG. 12 is a cross-sectional view of a motor of a handheld power tool according to the present invention.

detailed description

In order to make the foregoing objects, features, and advantages of the present invention more comprehensible, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Numerous specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the meaning of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be a centered element. When an element is considered to be "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 limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Please refer to FIG. 1, FIG. 4 and FIG. 6, the first embodiment of the present invention provides a hand-held power tool 100, which can improve the overall heat dissipation and cooling effect. In this embodiment, the handheld power tool 100 includes a casing, which includes a head casing 110 and a holding portion 130 disposed at an angle to the head casing 110. The casing is provided with an air inlet and an air outlet. The motor 120 is disposed in the head case 110 and has an output shaft 126, a motor case, and a fan. The motor case is provided with air inlet holes and air outlet holes 176. The output shaft 126 of the motor 120 is connected to a transmission mechanism, and the transmission mechanism is connected to the work head 150 to drive the work of the work head 150. The output shaft can also be connected directly to the work head. The working head 150 may be a cutting sheet for cutting, a grinding sheet for grinding, a polishing sheet for polishing, or the like. In practice, different working modes are implemented by different working heads 150. A safety shield 114 is fixedly connected to the outer side of the working head 150, and has a posture of semi-enveloping the working head 150. Other shields can be added according to the working mode to prevent sputtering of grinding particles and the like, thereby further improving safety. In this embodiment, a safety shield 114 is provided on the outside of the working head 150 for use as a matte shield, and a cutting shield may also be provided to improve safety.

The electric machine 120 includes a stator provided in a housing of the electric machine 120, wherein the stator is in interference fit with the housing of the electric machine 120. The stator belongs to the stationary part of the motor 120, and its main function is to generate a rotating magnetic field. In order to prevent the stator from rotating when the motor 120 starts and stops, an interference fit is set between the stator and the housing of the motor 120 to ensure that the stator is in a relatively stationary state.

The motor casing has opposite head ends 122 and tail ends 124, and the output shaft protrudes from the head ends. The air inlet hole includes a first air inlet hole 123 provided at the head end and a second air inlet hole 125 provided at the tail end. The output shaft protrudes from the head end, which is convenient for assembling the working head or other transmission mechanism. When the motor drives the fan to rotate, a first heat dissipation air path is formed in the head case from the first air inlet hole into the motor housing, and flows out from the air outlet hole, and the second air inlet hole enters the inside of the motor housing, The second heat dissipation air path flowing from the air outlet. The cooling air enters the air from the head end and the tail end of the motor, the air intake volume increases, and the cooling effect on the motor is better.

The working head 150 is driven and rotated by the output shaft, and may be directly driven or rotated by the output shaft 126 through the transmission mechanism. Through the transmission mechanism, the transmission mechanism can be connected to and driven by the output shaft 126.

The holding portion 130 is connected to the head case 110, and the holding portion 130 is disposed at an angle to the head case 110. The central axis of the holding portion and the axis of the output shaft may be perpendicular or may be disposed at other angles. The air outlet 177 is disposed on the head case 110 near the air outlet 176, so that the wind flowing out from the air outlet can be directly and quickly discharged from the air outlet to the outside of the cabinet. The air inlet includes a tail air inlet 173, and the tail air inlet 173 is provided near the tail end of the head shell; a first heat dissipation air duct is formed in the head shell, and the first heat dissipation duct and the second heat dissipation in the motor casing are formed. The wind is connected. When the fan is driven to rotate by the output shaft, the first cooling air duct enters air from the tail air inlet, flows through the second cooling air path, and exhausts air from the air outlet. The air flowing from the tail end air inlet into the casing enters the motor casing, which can cool the motor, and the tail air inlet is far away from the output shaft and far from the work area, so there is less dust and iron debris in the incoming wind. Wherein, the tail air inlet may be disposed on a side wall and / or an end wall of the head shell.

The air inlet also includes a head-end air inlet 172, which is located in the head case near the head end 122; a second heat-radiating air duct is formed in the head case 110, and the The first heat dissipation air path communicates. When the fan 128 is driven to rotate by the output shaft, the second heat dissipation air duct enters the air from the air inlet at the head end, flows through the second heat dissipation air path, and exhausts the air from the air outlet. The air flowing from the tail air inlet into the casing enters the motor casing, which can effectively cool the motor. In order to prevent dust and iron filings from flowing into the motor from the air inlet at the front end and the first air inlet with the wind, a protective net is provided at the first air inlet and / or the air inlet at the first end. Since the first air inlet and the head-end air inlet 172 are relatively close to the working head 150, when the work head 150 is in a working state, especially in a sanding condition, a large amount of workpiece debris is easily removed from the head-end air inlet 172. Inhalation enters the inside of the housing of the motor 120 through the first air inlet, which affects the operation of the motor 120. Therefore, the first air inlet and / or the head air inlet 172 is provided with a protective net, which can largely prevent workpiece debris from entering the interior of the housing of the motor 120. The mesh number of the protective net (the larger the mesh number, the smaller the mesh hole diameter) is generally 60 to 140. If the mesh number is too small, the mesh size is too large, and the workpiece debris easily passes through the mesh and cannot prevent it. If the mesh size is too large, the mesh size is too small, which affects the air intake effect.

The number and shape of the air inlets are not limited. On the premise of ensuring the strength of the housing of the motor 120, multiple air inlets may be provided, and the shape may be circular, oval, rectangular, or the like. The heat source of the motor 120 is the motor core. The casing of the motor 120 is provided with a plurality of air inlet holes, so that the wind entering from the air inlet at the head end or the air inlet at the tail end can flow more through the inside of the housing of the motor 120 , For the motor 120 core cooling and cooling. Of course, the wind entering from the air inlet at the head end or the air inlet at the tail end will also flow through the exterior of the housing of the motor 120 to improve the heat dissipation effect. Wind holes 176 may be provided at intervals around the circumferential contour of the casing of the motor 120, or a cylindrical opening may be opened along the circumferential contour of the casing of the motor 120 to form the ventilation holes 176. The wind flowing through the inside of the housing of the motor 120 is discharged from the air outlet 176 and directly flows to the air outlet 177.

The air inlet also includes a handle air inlet 171 provided at the holding portion 130. A third heat dissipation air duct is formed in the grip portion 130, and the third heat dissipation air duct is in communication with the first heat dissipation air path. When the fan is driven to rotate by the output shaft, the wind entering from the air inlet of the handle flows through the third heat dissipation air passage and enters the motor casing through the first air inlet. It can be seen that the third cooling air duct is connected with the first cooling air path. After entering the air from the first air inlet, first cool the holding part, then enter the head shell, cool the motor, and then discharge it from the air outlet. Lowering the temperature of the holding part makes the holding operation more comfortable, and also reduces the temperature of the head shell and the motor, ensuring the working efficiency and the life of the motor.

As shown in FIG. 6, an electronic component is disposed in the holding portion 130 and includes at least a circuit board 132 and a switch assembly 190. A circuit board 132 is disposed in the holding portion 130, and a heat sink 134 is disposed on the circuit board 132. Specifically, the circuit board 132 is electrically connected to the battery pack 160. The circuit board 132 constitutes a part of the working circuit. The circuit board 132 is an electronic component and is easy to generate heat and heat during work. Therefore, a heat sink 134 is provided on the circuit board 132. In order to reduce the temperature rise of the circuit board 132. The heat sink 134 can be made of aluminum alloy, has good thermal conductivity, and can dissipate heat to the circuit board 132. Since the electronic components and the motor 120 both generate high heat, in order to improve the heat dissipation capability, in this embodiment, the grip portion 130 is provided with a handle air inlet 171, and the wind entering from the handle air inlet 171 can take away the grip 130 The heat generated inside enters the inside of the housing of the motor 120 through the air inlet, takes away the heat generated by the motor 120, flows out from the air outlet 176, and exhausts the air from the air outlet 177 to form a third heat dissipation air duct.

The motor 120 is further connected with a magnetic ring 129 to suppress high-frequency noise. A magnetic ring 129 is provided between the switching element 198 and the motor 120. The magnetic ring 129 can be used to reduce noise and improve the performance of the handheld power tool 100. Improve operator comfort.

Referring to FIG. 1, at a position close to the air outlet 176, an isolation rib 112 is provided between the inner wall of the holding portion 130, the outer wall of the housing of the motor 120 and the inner wall of the head case 110. It is isolated from the first air inlet so that the wind entering from the handle air inlet 171 can enter the motor 120 through the first air inlet. The function of the isolation rib 112 is to guide the wind from the holding portion 130, and to block the wind from the holding portion 130 from being directly discharged through the air outlet 176 and the air outlet 177, so that the wind from the holding portion 130 can be blocked. More through the first end 122 of the motor 120, enter the inside of the housing of the motor 120 through the first air inlet, and then discharge the head shell 110 to increase the heat radiation path of the wind from the holding portion 130, and play the role of the heat from the holding portion 130. Greater cooling effect of wind.

The holding portion 130 is further provided with a switch assembly 190. The switch component 190 is electrically connected to the circuit board 132. The switch component 190 is used to control the on-off of the working circuit, and then control the working state of the handheld power tool 100. The switch assembly 190 includes a switch button 192 provided outside the grip portion 130, a switch lever 194 provided in the grip portion 130 connected to the switch button 192, a return spring 196 connected to the switch lever 194, and a switch lever 194, The switching element 198 is connected to the return spring 196. At the same time, the switch assembly 190 is also electrically connected to the motor 120, specifically, the switch element 198 is electrically connected to the motor 120 to control the working state of the motor 120.

The circumferential contour size of the holding portion 130 matches the holding range of the hand, which is convenient for the operator to hold the operation for a long time. Electronic components and the like are also provided in the holding portion 130 to constitute a working circuit to control the operation of the motor 120. The traditional motor is set in the grip, and the motor generates a certain amount of heat during work, and this heat is transferred to the grip, so that when the operator uses the handheld power tool in the grip, the heat is transferred to the operator's On the hand, it affects the comfort of the operator. In this embodiment, the motor 120 is disposed in the head case 110, the holding portion 130 is connected to the head case 110, and the holding portion 130 and the head case 110 are disposed at an angle. In this way, by setting the motor 120 outside the gripping portion 130, the temperature rise of the gripping portion 130 is further reduced, the operator's operating comfort is improved, and the circumferential contour size of the gripping portion 130 can be reduced, which is convenient for operation Personnel hold for a long time. The motor 120 is disposed in the head housing 110 and is close to the working head 150, which can also reduce the torque output path of the motor 120 and reduce the loss of torque in the transmission process. Further, the holding portion 130 and the head case 110 are disposed at an angle. It can be understood that the holding portion 130 and the head case 110 are neither parallel nor collinear. The specific angle is determined according to the actual production to facilitate the operation of the operator. . In other words, the holding portion 130 is disposed at an angle to the head shell 110, which can also be understood as the central axis X of the holding portion 130 and the axis Y of the output shaft 126 are not parallel, that is, the central axis X of the holding portion 130 and the output shaft 126 The axis Y is neither coincident or side-by-side. In some specific embodiments, the central axis X of the holding portion 130 is perpendicular to the axis Y of the output shaft 126. From the external shape, the head shell 110 and the holding portion 130 have an approximately vertical relationship. The hand-held power tool 100 is in the shape of a gun as a whole, and has a more compact structure in the axial direction of the output shaft 126. The connection between the holding portion 130 and the head shell 110 is basically located in the middle of the head shell 110, which is convenient for operators to hold and operate.

Referring to FIG. 5, the holding portion 130 includes two Huff-type housings symmetrically. The handle air inlets 171 are symmetrically disposed on the two Huff-type housings, and the wind entering from the handle air inlets 171 passes through the circuit board 132. Huff-type housing is also called half-type housing, which is a common way of forming the housing in power tools. Most of the housing is divided into two parts along the axis of the housing, which facilitates the assembly of components in the housing. internal. The gripping portion 130 is usually formed by joining two symmetrical parts to facilitate disassembly and maintenance of the components in the gripping portion 130. As shown in FIG. 5, there are handle air inlets 171 on the upper and lower sides of the holding portion 130. The handle air inlet 171 is located at the position of the holding portion 130 and is close to the circuit board 132 to ensure entry from the handle air inlet 171. The wind can pass through the circuit board 132 to cool and cool the circuit board 132.

The hand-held power tool 100 further includes a battery pack 160. A battery pack mounting portion 1628 is provided at an end of the grip portion away from the head case. The battery pack 160 can be mated with the battery pack mounting portion 1628 in an insertion manner in a direction indicated by an arrow R. The battery pack 160 is fixedly connected or detachably connected to the holding portion 130, and provides a power source for the work of the handheld power tool 100. A battery pack or a battery pack composed of a plurality of batteries is installed in the battery pack 160. The battery may be a rechargeable battery or a non-rechargeable battery. The battery pack 160 has a mounting end 1632 matching the battery pack mounting portion 1628 and a bottom plane 1636 of the battery pack opposite the mounting end 1632. The battery pack 160 is provided with a plurality of batteries (not shown in the figure) arranged in parallel. The battery pack 160 is arranged in an elongated shape extending along the longitudinal axis Z, and the longitudinal axis Z is perpendicular to the output shaft axis Y in different planes. The angle of inclination of the axis of the holding portion and the bottom plane of the battery pack is between 100 and 120 degrees. The holding part is connected to the middle part of the head shell, and the holding part and the head shell are T-shaped. The axis of the grip portion passes through the head case and the battery pack. The length of the grip is set between 85mm and 115mm. The projection of the center of gravity of the handheld power tool to the plane of the bottom surface of the battery pack falls within the outline of the bottom surface of the battery pack, so that the bottom surface of the battery pack can support the handheld power tool upright on the horizontal plane.

In some embodiments, referring to FIG. 7, the transmission mechanism includes a hollow transmission shaft 142 sleeved on the output shaft 126. The portion of the output shaft 126 protruding from the head end 122 has a certain length, but is not directly connected to the working head 150. Instead, a hollow transmission shaft 142 is provided around the output shaft 126, and the transmission shaft 142 and the output shaft 126 are in interference. In cooperation, the output shaft 126 can drive the transmission shaft 142 to rotate. In this way, the entire motor 120 can be prevented from being replaced after the output shaft 126 is damaged, and only the transmission shaft 142 needs to be replaced, which reduces the maintenance cost.

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

Further, the transmission shaft 142 is also sleeved with a locking ring 144, the locking ring 144 is provided with a locking groove 146, and a locking component 180 that can cooperate with the locking groove 146 is also provided in the radial direction of the transmission shaft 142 to lock the transmission Rotating motion of the shaft 142. A locking ring 144 with a slot 146 is also sleeved around the transmission shaft 142. The lock ring 144 is located between two bearings. The lock ring 144 and the transmission shaft 142 are also arranged in an interference fit. When the working head 150 needs to be replaced, in order to prevent the transmission shaft 142 from being driven and rotated together, the locking assembly 180 is first mated with the slot 146 to prevent the rotation of the locking ring 144, thereby preventing the rotation of the transmission shaft 142, and then the work is replaced. Head 150. The locking assembly 180 can prevent the transmission shaft 142 from rotating when the working head 150 is replaced, which facilitates the replacement of the working head 150 and improves work efficiency.

In some embodiments, the locking assembly 180 includes a lock shaft button 182, a latch 186 connected to the lock shaft button 182, and an elastic member 184 sleeved on the latch 186. The latch 186 can overcome the resistance of the elastic member 184 to move and Cooperating with the slot 146 to lock the rotational movement of the transmission shaft 142, the elastic member 184 is configured to provide an elastic force to reset the latch pin 186.

Specifically, by pressing the lock shaft button 182, the drive bayonet 186 moves against the resistance of the elastic member 184 toward the transmission shaft 142 until the bayonet 186 and the groove 146 cooperate to lock the transmission shaft 142. At this time, the elastic member 184 Compressed. Because an elastic member 184, such as a spring, is provided between the latch 186 and the lock shaft button 182, when the lock shaft button 182 is no longer pressed, the elastic force when the spring recovers pushes the lock pin 186 to reset.

Referring to FIG. 2, the second embodiment of the present invention provides another hand-held power tool having the same or similar structure as the first embodiment, and details are not described herein again. The hand-held power tool 100 includes a casing, which includes a head casing 110 and a holding portion 130 disposed at an angle to the head casing 110. The casing is provided with an air inlet and an air outlet. The motor 120 is disposed in the head case 110 and has an output shaft 126, a motor case, and a fan. The motor case is provided with air inlet holes and air outlet holes 176.

The motor casing has opposite head ends 122 and tail ends 124, and the output shaft protrudes from the head ends. The air inlet hole includes a first air inlet hole 123 provided at the head end and a second air inlet hole 125 provided at the tail end. When the motor drives the fan to rotate, a first heat dissipation air path is formed in the head case from the first air inlet hole into the motor housing, and flows out from the air outlet hole, and the second air inlet hole enters the inside of the motor housing, The second heat dissipation air path flowing from the air outlet. The cooling air enters the air from the head end and the tail end of the motor, the air intake volume increases, and the cooling effect on the motor is better.

The air outlet 177 is disposed on the head case 110 near the air outlet 176, so that the wind flowing out from the air outlet can be directly and quickly discharged from the air outlet to the outside of the cabinet. The air inlet includes a tail air inlet 173, and the tail air inlet 173 is provided near the tail end of the head shell; a first heat dissipation air duct is formed in the head shell, and the first heat dissipation duct and the second heat dissipation in the motor casing are formed. The wind is connected. When the fan is driven to rotate by the output shaft, the first cooling air duct enters air from the tail air inlet, flows through the second cooling air path, and exhausts air from the air outlet. The air flowing from the tail end air inlet into the casing enters the motor casing, which can cool the motor, and the tail air inlet is far away from the output shaft and far from the work area, so there is less dust and iron debris in the incoming wind. Wherein, the tail air inlet may be disposed on a side wall and / or an end wall of the head shell.

The holding portion 130 is connected to the head case 110, and the holding portion 130 is disposed at an angle to the head case 110. The central axis of the holding portion and the axis of the output shaft may be perpendicular or may be disposed at other angles. An electronic component is disposed in the holding portion 130 and includes at least a circuit board 132 and a switch assembly 190. A circuit board 132 is disposed in the holding portion 130, and a heat sink 134 is disposed on the circuit board 132. Specifically, the circuit board 132 is electrically connected to the battery pack 160. The circuit board 132 constitutes a part of the working circuit. The circuit board 132 is an electronic component and is easy to generate heat and heat during work. Therefore, a heat sink 134 is provided on the circuit board 132. In order to reduce the temperature rise of the circuit board 132. The heat sink 134 can be made of aluminum alloy, has good thermal conductivity, and can dissipate heat to the circuit board 132.

Since the electronic components and the motor 120 both generate high heat, in order to improve the heat dissipation capability, the air inlet also includes a handle air inlet 171 provided on the holding portion 130, and a third heat radiating duct is formed in the holding portion 130. The heat dissipation air duct is in communication with the first heat dissipation air path. When the fan is driven to rotate by the output shaft, the wind entering from the air inlet of the handle flows through the third heat dissipation air passage and enters the motor casing through the first air inlet. It can be seen that the third cooling air duct is connected with the first cooling air path. After entering the air from the first air inlet, first cool the holding part, then enter the head shell, cool the motor, and then discharge it from the air outlet. Lowering the temperature of the holding part makes the holding operation more comfortable, and also reduces the temperature of the head shell and the motor, ensuring the working efficiency and the life of the motor.

Referring to FIG. 2, at a position close to the air outlet 176, an isolation rib 112 is provided between the inner wall of the holding portion 130, the outer wall of the housing of the motor 120, and the inner wall of the head case 110. It is isolated from the first air inlet so that the wind entering from the handle air inlet 171 can enter the motor 120 through the first air inlet. The function of the isolation rib 112 is to guide the wind from the holding portion 130, and to block the wind from the holding portion 130 from being directly discharged through the air outlet 176 and the air outlet 177, so that the wind from the holding portion 130 can be blocked. More through the first end 122 of the motor 120, enter the inside of the housing of the motor 120 through the first air inlet, and then discharge the head shell 110 to increase the heat radiation path of the wind from the holding portion 130, and play the role of the heat from the holding portion 130. Greater cooling effect of wind.

Referring to FIG. 3, the third embodiment of the present invention provides another hand-held power tool with the same or similar structure as the first embodiment, and details are not described herein again.

The hand-held power tool 100 includes a casing, which includes a head casing 110 and a holding portion 130 disposed at an angle to the head casing 110. The casing is provided with an air inlet and an air outlet. The motor 120 is disposed in the head case 110 and has an output shaft 126, a motor case, and a fan. The motor case is provided with air inlet holes and air outlet holes 176.

Since the electronic components and the motor 120 both generate high heat, in order to improve the heat dissipation capability, the air inlet also includes a handle air inlet 171 provided on the holding portion 130, and a third heat radiating duct is formed in the holding portion 130. The heat dissipation air duct is in communication with the second heat dissipation air path. When the fan is driven to rotate by the output shaft, the wind entering from the air inlet of the handle flows through the third heat dissipation air passage and enters the motor casing through the second air inlet. It can be seen that the third heat dissipation air duct is connected to the second heat dissipation air path. After entering the air from the first air inlet, first cool the holding part, then enter the head shell, cool the motor, and then discharge from the air outlet. Lowering the temperature of the holding part makes the holding operation more comfortable, and also reduces the temperature of the head shell and the motor, ensuring the working efficiency and the life of the motor.

Referring to FIG. 3, at a position close to the air outlet 176, an isolation rib 112 is provided between the inner wall of the holding portion 130, the outer wall of the housing of the motor 120, and the inner wall of the head case 110, and the isolation rib 112 will open the air outlet 176. It is isolated from the first air inlet so that the wind entering from the handle air inlet 171 can enter the motor 120 through the first air inlet. The function of the isolation rib 112 is to guide the wind from the holding portion 130, and to block the wind from the holding portion 130 from being directly discharged through the air outlet 176 and the air outlet 177, so that the wind from the holding portion 130 can be blocked. More through the first end 122 of the motor 120, enter the inside of the housing of the motor 120 through the first air inlet, and then discharge the head shell 110 to increase the heat radiation path of the wind from the holding portion 130 and exert the Greater cooling effect of wind.

The technical features of the above embodiments can be arbitrarily combined. In order to make the description concise, all possible combinations of the technical features in the above embodiments have not been described. However, as long as there is no contradiction in the combination of these technical features, they should be It is considered to be the range described in this specification.

The above embodiments only express several implementation manners of the present invention, and their descriptions are more specific and detailed, but they cannot be understood as a limitation on the scope of the invention patent. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent shall be subject to the appended claims.

Claims

A hand-held power tool, comprising:

A motor having a motor casing and an output shaft, and the motor casing is provided with an air inlet hole and an air outlet hole;

The casing includes a head casing for housing the motor and a holding part disposed at an angle to the head casing, and the casing is provided with an air inlet and an air outlet;

A fan connected to the output shaft;

Wherein, the motor housing has a head end and a tail end opposite to each other, and the air inlet hole includes a first air inlet hole provided on the head end and a second air inlet hole provided on the tail end, and An air outlet hole is provided between the head end and the tail end, and the output shaft extends from the head end; when the fan is driven to rotate by the output shaft, a self-propelled fan is formed in the motor housing. An air inlet hole enters the inside of the motor housing, a first heat dissipation air path flowing out from the air outlet hole, and a second air inlet hole enters the inside of the motor housing, and exits from the air outlet. The second heat dissipation air path flowing out of the hole.
The hand-held power tool according to claim 1, wherein the air outlet is provided on the head case near the air outlet.
The hand-held power tool according to claim 1, wherein the air inlet includes a tail air inlet, and the tail air inlet is provided near the tail end of the head shell; the casing A first heat dissipation air duct is formed therein, and the first heat dissipation air duct is communicated with a second heat dissipation air path in the motor casing; when the fan is driven to rotate by the output shaft, the first heat dissipation air duct is from the tail The air is introduced into the end air inlet, flows through the second heat dissipation air path, and exhausts air from the air outlet.
The hand-held power tool according to claim 3, wherein the air inlet includes a head-end air inlet, and the head-end air inlet is provided at a position of the head case near the head end; the casing A second heat dissipation air duct is formed therein, and the second heat dissipation air duct is communicated with the first heat dissipation air path in the motor housing; when the fan is driven to rotate by the output shaft, the second heat dissipation air duct is from the first The air is introduced into the end air inlet, flows through the second heat dissipation air path, and exhausts air from the air outlet.
The hand-held power tool according to claim 4, wherein the air inlet further comprises a handle air inlet provided at a grip portion, and a third cooling air duct and a third cooling air duct are formed in the casing. In communication with the first heat dissipation air path, when the fan is driven to rotate by the output shaft, the wind entering from the handle air inlet passes through the third heat dissipation air duct and enters the motor housing through the first air inlet hole.
The hand-held power tool according to claim 4, wherein the air inlet includes a handle air inlet provided in a grip portion, and a third heat dissipation air duct is formed in the casing, and the third heat dissipation air duct and When the second heat dissipation air path is communicated, when the fan is driven to rotate by the output shaft, the wind entering from the air inlet of the handle flows through the third heat dissipation air duct and enters the motor casing through the second air inlet.
The hand-held power tool according to claim 3, wherein the air inlet includes a handle air inlet provided at a grip portion, and a third heat dissipation air duct is formed in the casing, and the third heat dissipation air duct and When the first cooling air path is communicated, when the fan is driven to rotate by the output shaft, the wind entering from the handle air inlet passes through the third cooling air duct and enters the motor housing through the first air inlet.
The hand-held power tool according to any one of claims 5 to 7, wherein an electronic component is provided in the holding portion, at least including a circuit board and a switch assembly; wherein the circuit board is provided with heat dissipation. Sheet, the switch assembly is electrically connected to the circuit board, and the wind entering from the handle air inlet passes through the electronic component.
The hand-held power tool according to any one of claims 5 to 7, wherein the holding portion includes two Huff-type housings, and the handle air inlet is symmetrically disposed on the two Huffs. Style housing.
The hand-held power tool according to claim 5 or 7, wherein an inner wall of the casing is provided with an isolation rib plate, and the isolation rib plate is used to connect the air outlet hole with the first air inlet. The holes are isolated so that the wind entering from the air inlet of the handle enters the inside of the motor casing through the first air inlet.
The hand-held power tool according to claim 6, wherein an inner wall of the casing is provided with an isolation rib for isolating the air outlet hole from the second air inlet hole. Open so that the wind entering from the air inlet of the handle enters the inside of the motor casing through the second air inlet.
The hand-held power tool according to claim 3, wherein the tail air inlet is disposed on a side wall and / or an end wall of the head shell.
The hand-held power tool according to claim 4, wherein the first air inlet and / or the head air inlet is provided with a protective net.
The hand-held power tool according to claim 1, wherein the fan is disposed near the air outlet.
The hand-held power tool according to claim 1, further comprising a transmission shaft sleeved on the output shaft, and the transmission shaft is used for mating with a working head.
The hand-held power tool according to claim 15, characterized in that, along the axial direction of the transmission shaft, two bearings are provided on the transmission shaft at intervals to support the transmission shaft.
The hand-held power tool according to claim 16, wherein a lock ring is sleeved on the transmission shaft, a locking groove is provided on the lock ring, and a movable shaft is provided in a radial direction of the transmission shaft. The locking component cooperates with the clamping slot to lock the rotary motion of the transmission shaft.
The hand-held power tool according to claim 17, wherein the locking assembly comprises a lock shaft button, a bayonet connected to the lock shaft button, and an elastic member sleeved on the bayonet; The bayonet can overcome the resistance movement of the elastic member and cooperate with the bayonet to lock the rotational movement of the transmission shaft. The elastic member is configured to provide an elastic force for resetting the bayonet.
The hand-held power tool according to claim 1, wherein a battery pack mounting portion is provided at an end of the holding portion remote from the head shell; and the hand-held power tool includes a removably connected to the head A battery pack of a battery pack mounting portion, the battery pack is provided in an elongated shape extending along a longitudinal axis, the grip portion has a longitudinally extending grip portion axis, and the battery pack has a The mounting end and the bottom plane of the battery pack opposite to the mounting end, the axis of the grip portion is disposed at an angle to the bottom plane of the battery pack, and the longitudinal axis is perpendicular to the output shaft axis on a different plane.
The hand-held power tool according to claim 19, wherein an axis of the grip portion is perpendicular to an axis of the output shaft.
A hand-held power tool, comprising:

A casing, including a head casing, and a holding portion disposed at an angle to the head casing;

A motor provided in the head case, having a motor case, an output shaft, and a fan, and the motor case being provided with an air inlet hole and an air outlet hole;

The motor housing has a head end and a tail end opposite to each other, the output shaft protrudes from the head end, and the air inlet hole includes a first air inlet hole provided on the head end and the air inlet hole provided on the head end. A second air inlet hole at the rear end, the fan is disposed between the first air inlet hole and the second air inlet hole, and the air outlet hole is provided on the motor casing near the fan.