Hand-held power tool

Abstract

The application discloses a handheld electric tool, comprising: a head extending in the front-rear direction; a holding part protruding from the lower side of the head and extending to connect with a power supply device; a driving mechanism comprising a motor composed of a stator and a rotor, the motor further comprising at least three wires; the head is formed or fixedly connected with a wire clamping device, the wire clamping device is located between the head and the holding part to fix the wires. The above technical scheme provides a handheld electric tool with more stable motor output performance and longer service life of the power supply wire of the motor.

Description

Technical Field

[0001] This invention relates to a power tool, and more specifically to a handheld power tool. Background Technology

[0002] Handheld power tools are now widely used in various fields. Their advantages lie in their portability and ease of operation. The miniaturization of handheld tools further enhances the user experience and operational convenience, making them popular among users. However, under certain working conditions, during high-speed rotation or harsh operation, the power head of a handheld power tool vibrates significantly, causing the motor leads to bend and making the wires at and near the solder joints prone to breakage. This, to some extent, affects the lifespan of the motor leads. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a smaller handheld power tool.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A handheld power tool includes: a head extending in a front-rear direction; a grip protruding from the underside of the head and extending thereafter connected to a power supply; a drive mechanism including a motor consisting of a stator and a rotor, the motor further including multiple wires electrically connected to the power supply; and a wire clamping device formed or fixedly connected to the head, the wire clamping device being located between the head and the grip to secure the wires.

[0006] Furthermore, the wire clamping device has a plurality of clamping slots having a diameter approximately the same as that of the wire, and the wire is at least partially disposed within the clamping slots.

[0007] Furthermore, the stator has multiple coils wound around it, and at least two of the coils are connected to the conductor.

[0008] Furthermore, the wire clamping device also includes a plurality of connecting pieces, which are used to electrically connect the coil and the wire.

[0009] Furthermore, the connecting piece and the wire are electrically connected by solder.

[0010] Furthermore, the wire clamping device also includes an insulating sheet, and a plurality of the connecting pieces are fixedly installed to the insulating sheet so that they cannot conduct electricity to each other.

[0011] Furthermore, the side of the stator protrudes to form a first end, and the first end forms a slot, in which the insulating sheet is disposed.

[0012] Furthermore, the machine head also includes a machine barrel, the motor is disposed inside the machine barrel, the machine barrel has an anti-rotation part disposed opposite to the first end, the anti-rotation part has a receiving space, and the first end extends at least partially into the receiving space.

[0013] Furthermore, the wire clamping device is fixed to the anti-rotation part by means of screw fastening.

[0014] Furthermore, at least a portion of the wire clamping device is made of an elastic material. Attached Figure Description

[0015] Figure 1 This is a front view of the handheld power tool of the present invention;

[0016] Figure 2 yes Figure 1 A side view of the handheld power tool shown;

[0017] Figure 3 yes Figure 1 A side view of the head of a handheld power tool shown;

[0018] Figure 4 yes Figure 1 A cross-sectional view of the head of a handheld power tool is shown.

[0019] Figure 5a This is a perspective view of the head shell of one embodiment;

[0020] Figure 5b This is a perspective view of the head shell of another embodiment;

[0021] Figure 5c This is a perspective view of the head shell of another embodiment;

[0022] Figure 5d This is a perspective view of the head shell of another embodiment;

[0023] Figure 6 yes Figure 1 An exploded view of the head and handle of a handheld power tool.

[0024] Figure 7 yes Figure 3 An exploded view of part of the nose section of the aircraft shown.

[0025] Figure 8 yes Figure 3 The diagram shows the structure of the machine head's barrel and internal gear ring;

[0026] Figure 9 yes Figure 3 An exploded view of part of the nose section of the aircraft is shown.

[0027] Figure 10a This is a structural diagram of another embodiment where the internal gear ring is fixed to the barrel;

[0028] Figure 10b This is a structural diagram of another embodiment in which the internal gear ring is fixed to the barrel;

[0029] Figure 11 This is a structural diagram of one embodiment of stator anti-rotation of an electric motor;

[0030] Figure 12 This is a structural diagram of one embodiment of a nameplate being installed on the barrel;

[0031] Figure 13 This is a structural diagram of a wire clamping component as one embodiment;

[0032] Figure 14 This is a cross-sectional view of a handheld power tool as an example;

[0033] Figure 15 yes Figure 14 Exploded images of some components;

[0034] Figure 16 yes Figure 15 Structural diagram of the stator and stator pressure plate in the middle;

[0035] Figure 17 yes Figure 15 Structural diagram of the central fan and the second elastic element;

[0036] Figure 18 This is a partial cross-sectional view of a handheld power tool as another embodiment. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings.

[0038] See appendix Figure 1 The present invention provides an electric tool 100, specifically a handheld electric tool, wherein in the embodiment of the present invention it is an impact wrench, but it can also be an impact screwdriver or an electric drill.

[0039] like Figure 1 and Figure 2As shown, the handheld power tool 100 includes a head 101 and a grip 104. The head 101 is fixedly connected to the grip 104. The head 101 houses a drive mechanism 200, a transmission mechanism 400, and an output mechanism 300. The drive mechanism 200 includes a motor and a drive shaft; the transmission mechanism 400 includes a gear assembly 410 and connects the drive mechanism 200 and the output mechanism 300; the output mechanism includes an output shaft 332 and a working attachment connected to the output shaft 332. The drive mechanism 200, transmission mechanism 400, and output mechanism 300 are sequentially and drively connected within the head 101 along the extension direction of a straight line 102 (defined as the axial direction). The grip 104 is located below the head 101 (the vertical direction of the handheld power tool 100 is consistent with the upright direction in the illustration), allowing the user to hold it in their hand. The grip 104 includes a trigger 105, which the user pulls to activate the handheld power tool 100. A control mechanism (not shown) is located within the grip 104. This control module is responsible for the electronic control of the handheld power tool 100 and will not be described in detail here. The present invention does not limit the specific location of the control module. A power supply device is connected to the lower part of the grip 104. This power supply device supplies power to the power tool 100; in this embodiment, the power supply device is a battery pack. The battery pack is electrically connected to the control mechanism and the drive mechanism 200, providing power to the drive mechanism 200. Of course, the power tool can also be an AC tool, in which case the power supply device includes a plug and power cord for connection to AC power.

[0040] For ease of description, Figure 1 and Figure 2 The forward / backward and left / right directions are defined as shown in the figure. See also Figure 1 and Figure 2 The majority of the body of the handheld power tool 100 is enclosed in a housing 110. In this embodiment, the housing 110 includes a barrel 111 located at the head 101, a head housing 112, a tail housing 113, and a handle housing 114 located at the grip portion 104. The handle housing 114 is generally symmetrical about line 103. In one embodiment, the handle housing 114 is composed of a left handle housing 114a and a right handle housing 114b. The left handle housing 114a and the right handle housing 114b can be plastic parts, and their surfaces are at least partially covered with an anti-slip material such as rubber or silicone to obtain a better feel. In fact, the barrel 111 and the head housing 112 are also generally symmetrical about line 103. Unlike the handle housing 114, the barrel 111 is a single piece, and the head housing 112 is also a single piece. Optionally, the barrel 111 is a metal part, and the head housing 112 is also a metal part.

[0041] See Figure 3As shown in Figure 5, the head housing 112 is located at the front end of the entire head 101, and the rear end of the head housing 112 extends into the front end of the barrel 111. The barrel 111 is located behind the head housing 112. In one embodiment, the barrel 111 and the head housing 112 are connected by a thread. That is, the portion of the head housing 112 extending into the barrel 111 has an external thread 135, and the portion of the barrel 111 that contacts the head housing 112 has an internal thread 136. When the head housing 112 is screwed into the barrel 111, the external thread 135 of the head housing 112 and the internal thread 136 of the barrel engage to form a threaded connection. Traditional screw connections require additional space for the screw post and screw hole, increasing the radial dimension of the head 101. In contrast, threaded connections do not require additional radial space, reducing the radial dimension of the head 101. This allows the handheld power tool 100 to be used in narrower spaces, improving the user experience.

[0042] To facilitate tightening the barrel 111 and head housing 112, making the assembly process easier and ensuring a more secure connection between them, a locking structure can be added to the head housing 112. See [link to relevant documentation]. Figure 5a A boss 161 is formed at the front end of the head housing 112. In one embodiment, the boss is shaped like a hexagonal flange, and a through hole 165 is formed at the center of the boss 161. An output shaft 332 is at least partially received within the head housing 112, and the front end of the output shaft 332 extends outward from the through hole 165 of the boss 161. The output shaft 332 can be connected to a working accessory and output power externally. Optionally, the boss 161 is integrally formed with the head housing 112. It is worth noting that the boss of the present invention is not limited to a hexagonal or even polygonal boss. See also Figure 5b The boss 162 is gear-shaped, and when the head housing 112 is assembled, force can be applied to the recessed area on the side of the boss 162. Similarly, a through hole 166 is formed in the center of the boss 162 to allow the front end of the output shaft 332 to extend outward from the through hole 166 of the boss 162. Optionally, the boss 162 is integrally formed with the head housing 112. Furthermore, the locking structure is not limited to the boss, and the locking structure does not necessarily have to be located at the front end of the head housing. See also... Figure 5c Multiple recesses 163 are circumferentially distributed around the head housing 112. When assembling the head housing 112, a robotic gripper can simultaneously grasp the multiple recesses 163 to apply force, or a corresponding tooling kit can be used to apply force to the multiple recesses 163. Optionally, the multiple recesses 163 are integrally formed with the head housing 112. Similarly, see... Figure 5dMultiple protrusions 164 are circumferentially distributed around the head housing 112. When assembling the head housing 112, the multiple protrusions 164 can be forceped using corresponding tooling kits. Optionally, the multiple protrusions 164 are integrally formed with the head housing 112.

[0043] Furthermore, to further prevent the threaded connection between the barrel 111 and the head housing 112 from loosening during use of the handheld power tool 100, anti-loosening adhesive can be applied to the threads. The tail housing 113 is located at the rear end of the head 101 and is fixed to the barrel 111 from the rear end of the head 101 by screws. That is, from front to back, the head housing 112, the barrel 111, and the tail housing 113 are connected in sequence to form the head 101 of the handheld power tool 100, and the barrel 111 connects the head housing 112 and the tail housing 113 in the middle.

[0044] See Figure 6 As shown, a first mounting hole is provided on the upper part of the handle housing 114, and a second mounting hole 119 is provided on the protruding part 117 at the lower part of the barrel 111, which mates with the first mounting hole; optionally, there are two second mounting holes 119 at the lower part of the barrel 111. The grip part 104 and the head 101 are connected by a first fastener 50. Specifically, the handle housing 114 and the barrel 111 are connected by a first fastener 50, which passes through the first mounting hole and the second mounting hole 119 to connect the handle housing 114 and the barrel 111. Optionally, a soft rubber sleeve 60 is provided between the first fastener 50 and the second mounting hole 119, with two soft rubber sleeves 60 symmetrically arranged in each second mounting hole 119. When the handheld power tool 100 is working, the soft rubber sleeve 60 can reduce the vibration at the barrel 111, reduce the vibration impact, and thus achieve a vibration reduction effect. During installation, the two soft rubber sleeves 60 are inserted into the second mounting holes 119 from both ends.

[0045] Because the handle housing 114 includes a left handle housing 114a and a right handle housing 114b, the first mounting hole includes a through hole 133 on the left handle housing 114a and a threaded hole 134 on the right handle housing 114b corresponding to the through hole 133. Optionally, the first fastener 50 is a screw, and the soft rubber sleeve 60 is placed in the second mounting hole 119 and fitted onto the screw post. The screw passes through the through hole 133 and connects to the threaded hole 134. To facilitate the installation and removal of the soft rubber sleeve 60, a limiting flange is provided at one end of the soft rubber sleeve 60. Soft rubber sleeves 60 are provided on both sides of the second mounting hole 119 to ensure vibration damping effect. During installation, the soft rubber sleeve 60 is inserted into the second mounting hole 119, the protrusion 117 of the barrel 111 is clamped between the first housing 101 and the second housing 102, and then locked by the first fastener 50.

[0046] In one embodiment, the integrated barrel 111 serves as both the housing of the motor 210 and the housing of the gear assembly 410. The drive mechanism 200 includes a motor 210 and a drive shaft 220. The motor 210 converts electrical energy supplied by the battery pack into mechanical energy, and the drive shaft 220 transmits the rotational motion output by the motor 210 to the main shaft 320, ultimately converting the rotation of the main shaft 320 into rotational pulses for the rotational impact assembly 330. Specifically, the front end of the drive shaft 220 is provided with a drive gear (not shown), which is connected to other gears on the gear carrier 414, such as a planetary gear 415, for transmitting the rotation of the drive shaft 220 to the main shaft 320, thereby achieving power transmission. See also... Figures 7 to 8 The drive mechanism 200 is at least partially housed in the barrel 111. The internal space of the barrel 111 is approximately cylindrical. A partition 120 perpendicular to the drive shaft 220 is formed inside the barrel 111. The partition 120 divides the cylindrical cavity within the barrel 111 into two axially (front-back) different axially positioned cavities. One side of the partition 120 is the first cavity 131, and the other side is the second cavity 132. Figure 1 In the defined front-to-back direction, the motor 210 is installed in the first receiving cavity 131 located behind the partition 120, and the gear assembly 410 is installed in the second receiving cavity 132 located in front of the partition 120. A through hole 121 is provided in the center of the partition 120 for the drive shaft 220 to pass through. One end of the drive shaft 220 is fixedly connected to the motor 210 in the first receiving cavity 131, and the driving gear at the other end meshes with the gear assembly 410 in the second receiving cavity 132. Optionally, the through hole 121 is circular, and since the shape of the inner cavity of the barrel is approximately cylindrical, the partition 120 is roughly annular. Of course, the partition can also be set in other shapes to achieve a similar function. Optionally, the partition 120 is also a metal part, integrally formed with the barrel 111. The tail housing 113 is located at the rear end of the barrel 111. A plurality of first fasteners 50 pass sequentially from the rear end of the tail housing 113 through a plurality of mounting holes 151 in the tail housing 113, a plurality of mounting holes 152 in the motor end plate 211, and finally are fixed to a plurality of mounting holes 153 in the barrel 111. Optionally, the first fasteners 50 are screws, and the mounting holes 151, 152, and 153 are screw holes. Through the first fasteners 50 and their corresponding mounting holes, the motor 210 can be axially fixed within the enclosure of the tail housing 113 and the barrel 111, preventing axial movement of the motor 210. Of course, the method of fixing the motor 210 is not limited to using screws and mounting holes; the motor 210 can also be installed to the barrel 111 in other ways.

[0047] See Figure 7To better accommodate the motor 210, the barrel 111 is also designed with other adaptable structures, improving the performance of the handheld power tool 100 in multiple ways. In one embodiment, behind the partition 120, several axially extending positioning ribs 124 are distributed circumferentially on the inner wall of the barrel 111. These positioning ribs 124 not only enhance the strength of the barrel 111, but also center the motor 210 after it is installed in the barrel 111, improving the installation accuracy of the motor 210 and preventing the motor 210 from shaking inside the barrel 111, thus mitigating vibration during operation. In one embodiment, a ring of several discontinuous flanges 123 is distributed at the rear edge of the barrel 111. These flanges 123 may have the same shape and length, or they may have different shapes and lengths. After the motor 210 is installed into the barrel 111, these discontinuous flanges 123 are respectively inserted into the gap between the motor end plate 211 and the motor 210 body, thereby limiting the circumferential movement of the motor 210, improving the installation accuracy of the motor 210, and preventing the motor 210 from rotating relative to the barrel 111 during operation.

[0048] It is understood that the motors used in current power tools include a rotor and a stator, and can be divided into internal rotor motors and external rotor motors according to the rotor position. In this embodiment, motor 210 adopts an internal rotor rotation mode, which can be understood as the core in the middle of the motor being the rotating body. When motor 210 uses an internal rotor rotation mode, measures need to be taken to stop the stator of the motor from rotating. See also... Figure 11 As shown, the stator 215 has a protruding side that extends to form a first end portion 215a. The barrel 111 has an anti-rotation portion 111b opposite to the first end portion 215a. The first end portion 215a is disposed within the space formed by the anti-rotation portion 111b. Specifically, the anti-rotation portion 111b forms a groove that mates with the first end portion 215a, thereby preventing the stator 215 of the motor 210 from rotating. It is understood that this embodiment is only an exemplary method of preventing rotation and does not limit the specific shape or position of the first end portion 215a and the anti-rotation portion 111b. Those skilled in the art should make settings according to the actual situation.

[0049] See Figure 4 The motor 210 also includes a front bearing 213. See also Figure 7In one embodiment, a first bearing seat 122 is formed on one side of the partition 120. Specifically, the first bearing seat 122 is located in the first receiving cavity 131, and the first bearing seat 122 extends from the partition 120 and protrudes towards the rear of the barrel 111. When the motor 210 is installed in the barrel 111, the first bearing seat 122 accommodates the front bearing 213 of the motor 210 without occupying axial space, thus avoiding increasing the axial dimension of the barrel 111. In one embodiment, at least a portion of the surface of the barrel 111 is provided with a plurality of ventilation openings 125, which helps to improve the heat dissipation effect of the motor 210. Optionally, the plurality of ventilation openings 125 are circumferentially distributed on the side of the barrel 111. Further, the tail housing 113 is also provided with a plurality of ventilation openings 115. Optionally, the motor 210 uses an axial flow fan, and the plurality of ventilation openings 115 are circumferentially distributed on the side of the tail housing 113. When using the handheld power tool 100, because the vent 115 faces the air inlet of the fan 214 of the motor 210, the airflow enters from the vent 115 of the tail housing 113 and exits from the vent 125 of the barrel 111 under the drive of the fan 214 of the motor 210, achieving a good heat dissipation effect.

[0050] See Figure 12 As shown, the handheld power tool 100 also includes a nameplate 111f to identify the brand of the power tool and its corresponding parameter information. A slot 111e for mounting the nameplate 111f is formed on the barrel 111. During assembly, the nameplate 111f is pushed forward into the slot 111e and installed onto the barrel 111, and the tail housing 113 is then installed onto the barrel 111, thereby securing the nameplate 111f to the barrel 111. With this configuration, the nameplate 111f does not need to be replaced during after-sales maintenance of the handheld power tool 100, thus saving costs.

[0051] See Figures 8 to 9 The gear assembly 410 is mounted to the second receiving cavity 132 at the front end of the barrel 111. In one embodiment, the gear assembly 410 includes a non-rotating internal gear ring 411. Figure 8As shown, an inwardly protruding tooth 412 is formed within the internal gear ring 411 for meshing with a gear, for example, with a planetary gear 415 on the gear carrier 414, causing the planetary gear 415 to rotate within the internal gear ring 411, thereby driving the gear carrier 414 and the main shaft 320 to rotate. In one embodiment, the internal gear ring 411 has a first meshing portion, and the inner wall of the barrel 111 has a second meshing portion. The first meshing portion of the internal gear ring 411 meshes with the second meshing portion of the barrel 111, fixing the internal gear ring 411 to the barrel 111. Specifically, the internal gear ring 411 may have a plurality of axially protruding mounting feet 413 distributed circumferentially around the internal gear ring 411, and the inner wall of the barrel 111 has a plurality of mounting grooves 118 that mate with the mounting feet 413, wherein the plurality of mounting grooves 118 are disposed in front of the partition plate 120. Mounting foot 413 engages with mounting groove 118 to fix internal gear ring 411 inside barrel 111. Of course, the mounting method between internal gear ring 411 and barrel 111 is not limited to mounting foot and mounting groove. In one embodiment, an outer ring of teeth is formed on the outer side of internal gear ring 411, and an inner ring of teeth is formed on the inner wall of barrel 111. The outer teeth of internal gear ring 411 mesh with the inner teeth of barrel 111 to prevent internal gear ring 411 from rotating relative to barrel 111 in a circumferential direction. See also [other possible embodiment]. Figure 10a As shown, the mounting angle 413 of the internal gear ring 411 engages with the mounting groove 118 on the barrel 111 to limit the internal gear ring 411, while the internal gear ring limiting part 111a on the barrel 111 further limits the internal gear ring 411. During the production and assembly process, the internal gear ring 411 serves as an insert of the barrel 111, and the internal gear ring 411 is integrally formed with the barrel 111. As another possible embodiment, see [reference needed]. Figure 10b As shown, the mounting angle 413 of the internal gear ring 411 engages with the mounting groove 118 on the barrel 111 to limit the internal gear ring 411. Unlike the previous embodiment, the mounting angle 413 of the internal gear ring 411 and the mounting groove 118 on the barrel 111 are press-fitted, requiring tools to fix the internal gear ring 411 inside the barrel 111 during assembly. Furthermore, the internal gear ring 411 can also be indirectly installed to the barrel 111 via other auxiliary connecting parts, including but not limited to gaskets. In other words, as long as the internal gear ring 411 is installed inside the barrel 111, the invention does not limit its specific structure.

[0052] See Figure 4 The gear assembly 410 also includes a bearing 415. See [link / reference] Figure 8In one embodiment, a second bearing seat 126 is formed on the other side of the partition 120. Specifically, the second bearing seat 126 is located within the second receiving cavity 132, and the second bearing seat 122 extends from the partition 120 and protrudes towards the front of the barrel 111. When the gear assembly 410 is installed into the barrel 111, the second bearing seat 126 accommodates the bearing 415 of the gear assembly 410 without occupying axial space, thus avoiding increasing the axial dimension of the barrel 111. Further, the head housing 112 axially fixes the gear assembly 410. Specifically, see... Figure 9 As shown, after the head housing 112 is screwed into the barrel 111, the head housing 112 further presses the internal gear ring 411 and gear carrier 414 of the gear assembly 410 together through the gasket 70. In this way, the barrel 111, while serving as part of the housing and motor housing, also functions as a gearbox, reducing the number of parts, lowering assembly complexity, and reducing production costs. Moreover, since the traditional gearbox is eliminated, the overall structure of the head is more compact, and the radial dimension of the head is smaller, making it easier to apply in narrower spaces.

[0053] See Figure 9 As shown, the output mechanism 300 of the present invention includes a main shaft 320 and a rotary impact assembly 330, wherein the rotary impact assembly includes an impact block 331 and an output shaft 332. The main shaft 320 is fixedly connected to the gear carrier 414 or integrally formed. The main shaft 320 is drively connected to the output shaft 332 and the drive shaft 220. The main shaft 320 is provided with a V-groove for forming a rotary impact, thereby converting the continuous rotary output of the motor 210 into impact-type rotary pulses. Specifically, the V-groove on the main shaft 320 is connected to the impact block 331 through a steel ball for driving the axial impact of the impact block 331, thereby realizing the axial and rotary motion of the main shaft 320. At the same time, the rotary impact assembly 330 also includes a spring 333, which is used to reset the impact block 331. The output shaft 332 is located at the front end of the machine head 101 and is used to output power externally; specifically, the output shaft 332 can be connected to a working accessory and output power externally. For impact wrenches, the working attachment is a socket; for impact screwdrivers, the working attachment is a screwdriver bit.

[0054] In some embodiments, motor 210 is a three-phase brushless motor, including a rotor with permanent magnets and electronically commutated three-phase stator windings U, V, and W. The three-phase stator windings U, V, and W are connected in a star configuration. Of course, the three-phase stator windings U, V, and W can also be connected in a delta configuration. However, it must be understood that other types of brushless motors are also within the scope of this disclosure. Brushless motors may include fewer or more than three phases. See also... Figure 13 and Figure 14As shown, the handheld power tool 100 also includes a cable clamping device 116. Specifically, the cable clamping device 116 is located vertically between the head 101 and the grip 104. The head 101 is formed or fixedly connected to the cable clamping device 116, which is located between the head 101 and the grip 104 to secure the cable 210a. The grip 104 protrudes from the lower side of the head 101 and extends to connect to the power supply device 500. Specifically, the cable clamping device 116 is also provided with a slot 116a for securing the cable 210a. The cable clamping device 116 is fixedly connected to the anti-rotation portion 111b on the barrel 111 by screws 116c. During assembly, the screws 116c are used to fix the cable clamping device 116 to the anti-rotation portion 111b on the barrel 111 through the screw holes 116b on the cable clamping device 116 and the screw holes 111d on the anti-rotation portion 111b. Conductors 210a are connected to the three-phase stator windings U, V, and W respectively via corresponding connecting pieces 210b. It can be understood that in this embodiment, a three-phase brushless motor is used; therefore, the three-phase stator windings U, V, and W need to be connected to independent conductors 210a respectively. Figure 13 As shown, three conductors 210a and three connecting pieces 210b are provided. The conductors 210a and connecting pieces 210b are electrically connected by solder. Furthermore, to ensure insulation between the three conductors 210a, the three connecting pieces 210b are fixedly connected to an insulating sheet 210c. Specifically, the connecting pieces 210b and the insulating sheet 210c are integrally formed. Of course, the connecting pieces 210b can also be installed onto the insulating sheet 210c by a tight fit or other fixing methods, as long as the connecting pieces 210b can be fixedly installed onto the insulating sheet 210c and the connecting pieces 210b remain insulated from each other. The connecting pieces 210b can be made of a conductive metal material. It can be understood that the U, V, and W phase windings of the motor 210 are first connected to the connecting pieces 210b, and then connected to the conductors 210a through the connecting pieces 210b. Preferably, the wire clamping device 116 can be made of a flexible and insulating material. During the operation of the handheld power tool 100, the power head vibrates significantly, causing the wire 210a to bend. Installing a wire clamping device 116 on the barrel 111 allows the solder joint and solder creep position between the wire 210a and the connecting piece 210b to move synchronously with the barrel 111, shifting the bend to the far end and improving wire lifespan. See also Figure 13 As shown, the insulating sheet 210c is fixedly connected to the first end 215a of the stator 215. Specifically, the first end 215a of the stator 215 forms a slot (not shown), and the insulating sheet 210c is disposed in the slot to be fixed to the stator 215.

[0055] In some embodiments, see Figures 14 to 16As shown, a stator pressure plate 216 is also provided between the barrel 111 and the tail housing 113 to limit the stator 215 in the front-rear direction. The stator pressure plate 216 has screw holes. During assembly, the tail housing 113 is fixedly installed to the barrel 111 together with the stator pressure plate 216 by tightening screws. At this time, the tail housing 113 applies a forward thrust to the stator pressure plate 216, and further, the stator pressure plate 216 applies a forward thrust to the stator 215. It can be understood that due to accumulated errors and machining tolerances during the processing of the above components, there will be a certain gap between the stator pressure plate 216 and the stator 215 in the front-rear direction, so that the thrust applied by the tail housing 113 to the stator pressure plate 216 cannot be well transmitted to the stator 215, thus limiting the stator 215. To solve the above problem, in this embodiment, a first elastic element 212 is provided between the stator pressure plate 216 and the stator 215. Specifically, the motor 210 also includes a stator rear end cover 215c disposed at the rear end of the stator 215. An annular boss 215b is formed on the stator rear end cover 215c. The first elastic member 212 is sleeved on the annular boss 215b. Further, the stator rear end cover 215c is provided with multiple notches (not shown) along the circumferential direction. The multiple notches overlap with the projection of the first elastic member 212 on the plane perpendicular to the output shaft. When the first elastic member 212 undergoes elastic deformation, it can deform into the aforementioned notches.

[0056] It is understood that the first elastic element 212 can undergo a certain deformation under the action of force. When the tail housing 113 applies a forward thrust to the stator pressure plate 216, the stator pressure plate 216 applies a thrust to the stator rear end cover 215c through the first elastic element 212, and further applies a forward thrust to the stator 215, the first elastic element 212 deforms. The deformation of the first elastic element 212 depends basically on the magnitude of the thrust and the gap between the stator pressure plate 216 and the stator rear end cover 215c. Specifically, in this embodiment, the first elastic element 212 is an O-ring made of rubber. Of course, the elastic element 216 can also be provided on the stator pressure plate 216 or the stator rear end cover 215c, or integrally formed with the stator pressure plate 216 or the stator rear end cover 215c, and there is no limitation here.

[0057] To further limit the stator 215 in the front-rear direction, a barrel boss 111c is provided at the front end of the barrel 111. Specifically, the barrel boss 111c is provided on the inner wall of the barrel 111 and is integrally formed with the barrel 111. Specifically, the motor 210 also includes a stator front end cover 215d provided at the front end of the stator 215, and a barrel boss is also formed inside the barrel. The stator front end cover is partially located between the stator and the barrel boss in the front-rear direction. The barrel boss 111c and the stator front end cover 215d abut against each other in the front-rear direction to achieve limitation. Preferably, the barrel boss 111c is integrally formed with the barrel 111. During the assembly process, the motor 210 is first placed in the barrel 111 in the front-rear direction. When the stator front end cover 215d of the motor 210 contacts the barrel boss 111c, the first step of limitation in the front-rear direction is achieved. After the first elastic element 212 is fitted onto the annular boss 215b of the stator rear end cover 215c, the stator pressure plate 216 is placed, and finally the tail housing 113 and the stator pressure plate 216 are fixedly installed onto the barrel 111 with screws, completing the second step of limiting. It can be understood that after the above assembly is completed, the stator 215 is limited in the forward direction by the barrel boss 125b, and in the rearward direction by the first elastic element 212. Through the above technical solution, when the user is using the handheld power tool 100, even under relatively harsh working conditions, the stator 215 of the motor 210 will not displace in the forward and backward directions due to vibration.

[0058] In some embodiments, see Figures 14 to 17 As shown, the motor 210 also includes a rotor 218 and a rotor rear balance ring 219 disposed behind the rotor 218. Typically, a balance ring is installed on the shaft of a motor rotor for balancing purposes. In most existing motors, the rotor balance ring is installed outside the rotor end ring, serving to protect the rotor end ring and prevent destructive deformation due to temperature and centrifugal force during motor operation.

[0059] See Figure 14 As shown, the fan 214 and motor 210 are arranged sequentially inside the casing 111. When the motor 210 is working, the fan 214 rotates to generate airflow, thereby carrying away the heat generated on the motor 210. However, due to manufacturing errors or accumulated design errors, a certain gap exists in the front-to-back direction after the motor 210 and fan 214 are placed inside the casing 111. This gap makes the rotor rear balance 219 prone to loosening when the motor 210 is working, thus failing to adequately protect the rotor 218. To eliminate this gap, see [reference needed]. Figure 17As shown, a second elastic element 217 is also provided between the fan 214 and the rotor rear balance ring 219. Specifically, the fan 214 includes a first end (not shown) near the rotor rear balance ring 219, and a mounting portion 214a for placing the elastic element is formed or connected to the front side of the first end. Preferably, the mounting portion 214a is configured as an annular groove. The second elastic element 217 is installed in the aforementioned annular groove. Specifically, the second elastic element 217 and the annular groove can be installed with a tight fit, or they can be integrally formed, or other assemblies, which is not limited here. Of course, in the above solution, the mounting portion 214a for placing the second elastic element 217 is provided on the side of the first end of the fan 214 near the motor 210 mainly for considerations such as the size of 210 in the front-rear direction and the simplicity of design. If the above factors do not need to be considered during design, a groove can be provided on the rotor rear balance ring 219 for placing the elastic element. The placement position of the second elastic element 217 is not limited in this invention.

[0060] See Figures 14 to 17 As shown, when the second elastic member 217 is placed in the annular groove 214a on the fan 214, the length of the second elastic member 217 in the front-rear direction is greater than the depth of the annular groove 214a. When the tail housing 113 is fastened to the barrel 111 with screws, the interference fit of the second elastic member 217 can eliminate the aforementioned gap, thereby pressing the rotor rear balance ring 219 in the front-rear direction. In this way, even when the motor 210 is rotating at high speed or the power tool is working under various conditions, the rotor rear balance ring 219 can press the rotor 218, thus improving the service life of the motor 210.

[0061] In other embodiments, see Figure 18 As shown, the motor 210 is housed in the tail housing 113c, and is preferably an internal rotor motor. The motor 210 includes a rotor 218 disposed inside and a stator 215 disposed outside the rotor 218. A rotor front balance ring 219c is also provided at the front end of the rotor 218. The motor 210 also includes a motor bearing 210d, which is sleeved on the output shaft of the motor 210. Unlike some of the embodiments described above, a second elastic member 217c for limiting the rotor 218 in the longitudinal direction is disposed between the rotor front balance ring 219c and the motor bearing 210d, and the fan 214c directly abuts against the rotor rear balance ring 219, thereby achieving the positioning of the rotor 218 in the longitudinal direction. The positioning method of the stator 215 in the longitudinal direction also differs from some of the embodiments described above. See [link to previous section]. Figure 18As shown, in this embodiment 11c, the motor 210 is disposed within the receiving space formed by the tail housing 113c, and the stator pressure plate 216c is disposed at the front end of the stator 215. Specifically, the stator pressure plate 216c is disposed at the front end of the stator front end cover 215d. A first elastic member 212c is disposed between the stator pressure plate 216c and the stator front end cover 215d, thereby achieving the positioning of the stator 215 in the front-rear direction.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1.A hand-held electric power tool, comprising: a head extending in a front-rear direction; a handle located at a lower side of the head and connected with a power supply device; the head comprising at least a driving mechanism, the driving mechanism comprising a motor composed of a stator and a rotor, the motor further comprising a plurality of wires, the wires being electrically connected with the power supply device; wherein, the head is formed or fixedly connected with a wire clamping device, the wire clamping device being located between the head and the handle to fix the wires; the wire clamping device further comprising a plurality of connecting pieces, the connecting pieces being synchronously moved with the head at the welding positions between the connecting pieces and the wires. 2.The hand-held electric power tool according to claim 1, wherein, the wire clamping device is formed with a plurality of clamping grooves having substantially the same diameter as the wires, the wires being at least partially arranged in the clamping grooves. 3.The hand-held electric power tool according to claim 2, wherein, the stator is wound with a plurality of coils, at least two of the coils being connected with one of the wires. 4.The hand-held electric power tool according to claim 3, wherein, the connecting pieces are used to electrically connect the coils with the wires. 5.The hand-held electric power tool according to claim 4, wherein, the connecting pieces are electrically connected with the wires through soldering. 6.The hand-held electric power tool according to claim 5, wherein, the wire clamping device further comprises an insulating piece, the connecting pieces being fixedly installed to the insulating piece to make them unable to conduct electricity. 7.The hand-held electric power tool according to claim 6, wherein, a side surface of the stator is protruded to form a first end portion, the first end portion is formed with a slot, and the insulating piece is located or arranged in the slot. 8.The hand-held electric power tool according to claim 7, wherein, the head further comprises a barrel, the motor is arranged in the barrel, the barrel is formed with a rotation-stopping portion arranged opposite to the first end portion, the rotation-stopping portion is formed with a containing space, and the first end portion is at least partially extended into the containing space. 9.The hand-held electric power tool according to claim 8, wherein, the wire clamping device is fixed to the rotation-stopping portion through screw fastening. 10.The hand-held electric power tool according to claim 1, wherein, at least a part of the wire clamping device is made of elastic material.

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