Electric tool

Abstract

The utility model provides an electric tool. The electric tool comprises a shell; a first circuit board; and a second circuit board; wherein the first circuit board and the second circuit board are both arranged in the shell, the heating value of electronic elements on the first circuit board during working is larger than that of electronic elements on the second circuit board during working, and the first circuit board and the second circuit board are arranged at different positions in the shell. The electronic components are arranged on the first circuit board and the second circuit board which are physically independent from each other, so that the internal space of the shell is fully utilized, the electronic components are arranged in a dispersed manner, the distribution density of the electronic components on the first circuit board and the second circuit board is reduced, and heat dissipation is facilitated.

Description

Technical Field

[0001] This utility model relates to power tools, specifically to a power tool with a start switch. Background Technology

[0002] Various power tools are already available on the market, such as chainsaws, angle grinders, and cutting machines. Taking a cutting machine as an example, when cutting certain workpieces with high hardness or thickness, the cutting machine's current increases. At this time, the cutting machine generates a lot of heat. To cope with this situation, power tools need to have good heat dissipation capabilities. Utility Model Content

[0003] Therefore, this utility model provides an electric tool with good heat dissipation capabilities.

[0004] To solve the above-mentioned technical problems, the present invention provides an electric tool, which includes: a housing; a first circuit board; and a second circuit board; wherein the first circuit board and the second circuit board are both disposed inside the housing, the electronic components on the first circuit board generate more heat during operation than the electronic components on the second circuit board, and the first circuit board and the second circuit board are disposed at different positions in the housing.

[0005] Optionally, the housing includes a head and a grip portion connected to the head, with a first circuit board disposed in the head and a second circuit board disposed in the grip portion.

[0006] Optionally, the device also includes a drive unit disposed in the head, the drive unit including a motor and a fan, the fan facing a first end of the motor, and the first circuit board facing a second end of the motor opposite to the first end.

[0007] Optionally, the first circuit board is located between the motor and the end of the head, the end of the head being provided with an air outlet.

[0008] Optionally, the end of the head is formed with an air outlet, and the first circuit board is positioned opposite the air outlet.

[0009] Optionally, the head and the gripping part are T-shaped.

[0010] Optionally, the first circuit board includes multiple metal-oxide-semiconductor field-effect transistors.

[0011] Optionally, the head has a circular cross-section, and the first circuit board is circular.

[0012] Optionally, a heat sink connected to the first circuit board may also be included.

[0013] Optionally, the device also includes a drive unit, a controller, and a speed control assembly disposed in the housing. The controller is electrically connected to the drive unit. The speed control assembly includes a knob, a gear, and a rotary potentiometer. The knob is rotatably connected to the housing. The inner sidewall of the knob is provided with teeth that mesh with the gear. The rotary potentiometer is fixed in the housing and electrically connected to the controller. The gear is coaxially fixed to the rotating shaft of the rotary potentiometer. When the knob is rotated, it can drive the gear to rotate. The rotating shaft can synchronously follow the rotation of the gear. The controller adjusts the output of the drive unit according to the resistance change of the potentiometer caused by the rotation of the rotating shaft.

[0014] The present invention has the following advantages: by placing the electronic components on two physically independent first and second circuit boards, it is beneficial to make full use of the space inside the casing, and the dispersed arrangement of the electronic components reduces the distribution density of the electronic components on the first and second circuit boards, which is beneficial for heat dissipation. Placing the first circuit board, which contains electronic components with high heat generation, near the air outlet will further improve heat dissipation; furthermore, placing the first circuit board downstream of the airflow channel and near the air outlet can further improve heat dissipation efficiency. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a perspective view of a power tool according to an embodiment of the present utility model.

[0017] Figure 2 This is a perspective view of the power tool according to an embodiment of the present invention, in which some elements are omitted.

[0018] Figure 3 This is an exploded view of a power tool according to an embodiment of the present utility model.

[0019] Figure 4 This is an exploded view of the power tool according to an embodiment of the present invention.

[0020] Figure 5 This is a perspective view of a button assembly of a power tool according to an embodiment of the present invention.

[0021] Figure 6 This is a perspective view of the button assembly of a power tool according to an embodiment of the present invention.

[0022] Figure 7 This is an exploded plan view of the button assembly of a power tool according to an embodiment of the present invention.

[0023] Figure 8 This is a perspective view of the base of the button assembly of a power tool according to an embodiment of the present invention.

[0024] Figure 9 This is a perspective view of the power tool according to an embodiment of the present invention, in which some elements are omitted.

[0025] Figure 10 This is an exploded view of a power tool according to an embodiment of the present invention, wherein some elements are omitted.

[0026] Figure 11 This is an exploded view of the power tool according to an embodiment of the present invention, in which some elements are omitted.

[0027] Figure 12 This is a perspective view of the power tool according to an embodiment of the present invention, in which some elements are omitted.

[0028] Figure 13 This is an exploded view of the power tool according to an embodiment of the present invention.

[0029] Figure 14 This is an exploded view of the power tool according to an embodiment of the present invention. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0032] refer to Figure 1-4 In one embodiment, a power tool 100 (e.g., a cutting machine) includes a housing 10, a trigger switch 20 (see... Figure 4 and Figure 5 The housing 10 has a slide 11 and a button assembly 30. The trigger switch 20 is located inside the housing 10. (See also...) Figures 5 to 8The button assembly 30 includes a button 31, a base 32, and an elastic element 33. The base 32 and the elastic element 33 are disposed inside the housing 10. The button 31 is movably connected to the housing 10. The button 31 includes a body 311 and a trigger part 312 connected to the body 311 and located inside the housing 10. One end of the body 311 passes through the slide groove 11 and is exposed. One end of the elastic element 33 abuts against the base 32, and the other end of the elastic element 33 abuts against either the body 311 or the trigger part 312. The elastic element 33 is in a compressed state. In use, the body 311 can move from an initial position to a first position along the slide groove 11 after being pushed by the user. Subsequently, the body 311 can move into the housing 10 under pressure from the user, moving the trigger part 312 to a second position that can trigger the trigger switch 20. Finally, the body 311 can move from the second position back to the initial position under the push of the elastic element 33.

[0033] In one embodiment, the trigger switch 20 serves as the start switch for the power tool 100; that is, the power tool 100 is started when the trigger switch 20 is triggered. Understandably, the trigger switch 20 can also be used to control other functions that require prevention of accidental operation, as needed. Furthermore, the power tool 100 is not limited to a cutting machine; it can be other types of power tools, such as screwdrivers, electric grinders, and electric saws.

[0034] With the above structure, when needed, the user can use their thumb to push and then press the button 31 to trigger the trigger switch 20, thus starting the power tool 100. Furthermore, the user can simultaneously push and press the button while gripping the housing 10, enabling one-handed operation. Because triggering the trigger switch 20 requires two steps (pushing and then pressing), this effectively prevents the power tool 100 from being accidentally started by the user pressing or pushing the button 31. In addition, these two steps can be easily completed by the user using only their thumb, improving operational efficiency.

[0035] In the above embodiments, the base 32 is an independent element. It can be understood that in other embodiments, the base 32 may be part of the housing 10. In this case, there is no independent base 32, and the housing 10 has a corresponding structure inside to realize the function of the base 32.

[0036] In one implementation, the initial position refers to Figure 1 The position where the middle body 311 abuts or nearly abuts the bottom end of the slide groove 11; the first position refers to... Figure 1The position where the main body 311 abuts against the top A of the slide 11. In this way, when the user pushes the main body 311, the main body 311 abuts against the top of the slide 11 and cannot move, which allows the user to perceive that the main body 311 has reached the first position, without the need for the user to visually determine whether the main body 311 has been pushed to the first position, which helps to improve operating efficiency.

[0037] In one embodiment, the inner surface of the groove 11 of the housing 10 has a stop protrusion 12 protruding at a position corresponding to the initial position (see...). Figure 1 and Figure 3 The button 31 body 311 also includes a stepped surface 313 (see...). Figure 7 In the initial position, the stepped surface 313 of the body 311 is located above the stop protrusion 12. The stepped surface 313, in conjunction with the stop protrusion 12, prevents the body 311 from moving into the housing 10 when pressure is applied in the initial position. The stepped surface 31 and the stop protrusion 12 are in contact, or there is a very small gap between them. After the body 311 is subjected to pressure unintentionally applied by the user in the initial position, the body 311 cannot move into the housing 10 because the stepped surface 313 is in contact with the stop protrusion 12, or the stepped surface 313 will immediately come into contact with the stop protrusion 12. That is to say, in the first position, the body 311 cannot move into the housing 10. The stop protrusion 12 exists only on a portion of the inner surface of the groove 11. In this embodiment, in Figure 1 From a distance, only the lower half of the inner surface of the slide groove 11 has a stop protrusion 12. Thus, when the body 311 moves to the first position, since there is no obstruction from the stop protrusion 12, the body 311 can move into the interior of the outer shell 10 under the pressure of the user.

[0038] In one embodiment, the housing 10 includes a first half-shell 101 and a second half-shell 102, which are detachably connected together to form the housing 10. The first half-shell 101 and the second half-shell 102, when connected together, form a head 103 and a grip portion 104. The head 103 is used to house the drive mechanism, transmission mechanism, first circuit board 61, etc., of the power tool 100, while the grip portion 104 houses the battery, second circuit board 62, etc., and is held by the user during use. In one embodiment, a groove 11 is provided in the grip portion 104, and the button assembly 30 is mostly housed within the grip portion 104. The housing 10 is generally T-shaped, meaning that the length direction of the head 103 is approximately perpendicular to the length direction of the grip portion 104. In this embodiment, the grip portion 104 is generally cylindrical, and the groove 11 extends along the length direction of the grip portion 104. This arrangement is ergonomic because when a user holds the grip 104, their thumb extends roughly along the length of the grip 104. The arrangement of the slide groove 11 makes it easier for the user's thumb to apply force to the button 31 of the button assembly 30.

[0039] It should be noted that, in one embodiment, the power tool 100 may also include a decorative housing 105 (see Figure 1 The decorative shell 105 is fitted around the circumferential side of the grip portion 104 to prevent screws and other structures on the grip portion 104 from being exposed and affecting the aesthetics.

[0040] In one embodiment, the trigger switch 20 is fixed to the second circuit board 62, located below the trigger portion 312 of the button assembly 30. The trigger switch 20 includes a body 21 and a cantilevered spring 22 connected to the body 21. The spring 22 deflects under pressure from the trigger portion 312, ultimately triggering the trigger switch 20. After the body 311 of the button assembly 30 returns to its initial position, the spring 22 returns to its original position under its own elastic force.

[0041] In one embodiment, the base 32 of the button assembly 30 includes a substrate 321, the first side of which (i.e. Figure 8 The top surface (as seen from the top) is provided with a through hole 322, and the first side surface protrudes with two spaced-apart side plates 323 located on both sides of the through hole 322. In one embodiment, a positioning part 324 protrudes from the outer surface of one side plate 323, and the outer shell is provided with a receiving groove, specifically, a receiving groove 1011 is provided on the inner side wall of the first half shell 101 (see...). Figure 3The positioning part 324 is precisely received within the receiving groove 1011, positioning the base 32 relative to the outer shell 10. That is, except in the direction of insertion and removal of the positioning part 324, the positioning part 324 cannot move relative to the first half-shell 101. The outer surface of the other side plate 323 of the base 32 abuts against the second half-shell 102. Thus, in the direction of insertion and removal of the positioning part 324, the base 32 is sandwiched between the first half-shell 101 and the second half-shell 102. In this way, the base 32 is restricted in all directions, thereby fixing it to the outer shell 10. It is understood that the fixing method of the base 32 is not limited to the aforementioned situation; other conventional connection methods, such as adhesive bonding or heat fusion bonding, can be used as needed.

[0042] refer to Figure 7 In one embodiment, the body 311 of the button 31 is generally an elongated rotating body, with the portion of the body 311 near its top exposed in the groove of the housing 10. The body 311 has a guide groove 314 extending along its length near its bottom. The body 311 passes through a through hole 322 on the base 32. Figure 7 From the displayed perspective, the body 311 can move vertically upwards or downwards relative to the base 32. Furthermore, the size of the through-hole 322 is larger than the radial dimension of the body 311, allowing the body 311 to swing within a certain range relative to the base 32.

[0043] In one embodiment, the second side of the substrate 321 opposite to the first side is provided with two spaced-apart fixing blocks 325. Each fixing block 325 has a through hole 326, and both ends of a shaft 34 are respectively received in the through holes 326, thereby fixing the shaft 34 to the two fixing blocks 325. The shaft 34 passes through a guide groove 314 of the body 311. Thus, the body 311 of the button 31 can move relative to the base 32, but it cannot detach from the base 32; that is, the body 311 of the button 31 is movably connected to the base 32 with two degrees of freedom. Since the base 32 is fixed in the housing 10, the body 311 of the button 31 is movably connected to the housing 10 with two degrees of freedom. In this embodiment, the swinging of the body 311 relative to the base 32 within a certain range means that the body 311 can actually rotate relative to the housing 10. Understandably, in other embodiments, the body 311 may be configured to slide relative to the housing 10 in two directions, i.e., the body 311 can slide from an initial position to a first position after being pushed, and then slide from the first position to the second position.

[0044] In one embodiment, the elastic element 33 is a cylindrical helical spring, which is sleeved on the circumferential side of the body 311 of the button 31. Figure 7From the perspective of [the viewpoint], the top end of the elastic member 33 abuts against the trigger portion 312 of the button 31, the bottom end of the elastic member 33 abuts against the first side surface of the substrate 321, and the elastic member 33 is in a compressed state. Thus, the elastic member 33 can apply an upward thrust to the trigger portion 312, causing the body 311 to remain in the initial position under normal conditions.

[0045] In one embodiment, the bottom end of the elastic member 33 is required not only to abut against the first side surface of the substrate 321, but also to be immobile relative to the substrate 321. Therefore, the base 32 also includes a barrel portion 327 protruding from the first side surface of the substrate 321. The barrel portion 327 communicates with the through hole 322 of the substrate 321, and the inner side surface of the barrel portion 327 is approximately flush with the inner side surface of the through hole 322. The body 311 passes through the barrel portion 327 first and then through the through hole 322. The bottom end of the elastic member 33 is tightly fitted onto the outer side surface of the barrel portion 327, thus fixing the bottom end of the elastic member 33 to the substrate 321 of the base 32. With this structure, after the body 311 of the button 31 swings from the initial position to the first position relative to the base 32, the bottom end of the elastic member 33 is fixed to the base plate 321 of the base 32, and the other parts of the elastic member 33 follow the movement of the body 311, thereby causing the elastic member 33 to bend. If the external force from the user acting on the body 311 disappears at this time, the elastic member 33 begins to recover its deformation from the bent state, thereby driving the body 311 to swing back from the first position to the initial position.

[0046] In one embodiment, the trigger portion 312 of the button 31 includes a fixing portion 3121 and a cantilever 3122. The fixing portion 3121 is fixed to the circumferential side of the body 311, and the cantilever 3122 is fixed to the fixing portion 3121. The extension direction of the cantilever 3122 is inclined relative to the body 311. When the body 311 is in the initial position, the end of the cantilever 3122 is above the end of the spring contact 22 of the trigger switch 20 that is connected to the body 21. When the body 311 moves to the first position, the end of the cantilever 3122 is above the free end of the spring contact 22 of the switch 20. At this time, if the user applies pressure to the body 311, the body 311 moves into the housing 10, moving from the end of the trigger portion 311 to the free end of the spring contact 22 of the trigger switch 20. The end of the trigger portion 312 will eventually contact the free end of the spring contact 22 and cause it to deflect, thereby triggering the trigger switch 20.

[0047] In one embodiment, a limiting member 35 is also fixed to the body 311 of the button 31. This limiting member 35 is generally a curved square plate, with a length and width greater than the length and width of the groove 11 of the housing 10. The limiting member 35 is located above the trigger portion 312, inside the housing 10, and directly opposite the groove 11. Thus, the limiting member 35 blocks the groove 11 from the inside of the housing 10, allowing the user to see only the limiting member 35 from the outside of the housing 10. This prevents components inside the housing 10 from being seen through the groove 11, thus maintaining the aesthetics of the power tool 100. When the body 311 is in its initial position, the limiting member 35 abuts against the inner surface of the housing 10. This prevents particles from entering the interior of the housing 10 through the groove 11 and also prevents the body 311 from being excessively exposed outside the groove 11 due to the pushing force of the elastic member 33.

[0048] As described above, the body 311 of button 31 is indirectly connected to the housing 10 with two degrees of freedom. The elastic element 33 applies a pushing force to the body 311, keeping it in the initial position under normal conditions. In use, the user first pushes the body 311 along the slide groove 11 of the housing 10 until the body 311 abuts against the other end of the slide groove 11. The user then applies pressure to the body 311, causing it to move inward into the housing 10. The trigger part 312 follows the body 311 and moves towards the trigger switch 20. During this process, the trigger part 312 contacts the spring piece 22 of the trigger switch 20 and pushes it to deflect until the trigger switch 20 is activated. During this process, the elastic element 33 first bends and then is compressed. When the user releases the body 311, the elastic element 33 rebounds, driving the body 311 back from the second position to the initial position.

[0049] In one embodiment, the head 103, because it houses the drive unit and transmission mechanism, and the transmission mechanism is connected to the execution module (e.g., the blade of a cutting machine and related protective cover), has a total weight greater than, or even significantly greater than, the total weight of the grip 104 and its related components. In this case, the center of gravity of the power tool 10 is located within the area defined by the head 103. If the button 31 of the button assembly 30 is far from the center of gravity of the power tool 10, it means that the user's grip position on the grip 104 is further away from the center of gravity of the power tool 10, requiring the user to apply more force to maintain the stability of the power tool 10. Therefore, the distance between the button 31 and the center of gravity of the power tool 100 is less than the distance between the trigger switch 20 and the center of gravity of the power tool 100. This arrangement allows the button 31 to be closer to the center of gravity of the power tool 100. Figures 1 to 3In this view, the button 31 is positioned between the head 103 and the trigger switch 20 along the length of the grip portion 104. In this view, when the body 311 of the button 31 is pushed to the first position, it moves toward the head 103.

[0050] The actuator module (e.g., the blade of a cutting machine) of the power tool 100 is connected to the drive shaft of the transmission device. If the drive shaft is free to rotate when replacing / installing the actuator module, it may cause inconvenience to the replacement / installation operation. To solve this problem, the power tool 100 also includes a locking structure 70, which can lock the drive shaft, thereby facilitating the user's operation of replacing / installing the actuator module.

[0051] Specifically, refer to Figures 9 to 11 The drive unit 40 includes a rotary motor 41 housed in the second half-shell 102 and fixed to the first half-shell 101 by screws. The transmission unit 50 includes an output shaft 51, a first gear 52 coaxially fixed to the output shaft 51, and a second gear 53 coaxially fixed to the motor shaft 411 of the rotary motor 41. The second gear 53 meshes with the first gear 52, and the motor shaft 411 drives the second gear 53 to rotate. The second gear 53 then drives the first gear 52 to rotate, and ultimately, the first gear 52 drives the output shaft 51 to rotate.

[0052] In one embodiment, the transmission device 50 further includes a bracket 54 and an end cap 55. The bracket 54 is housed in the first half-shell 101 and can be fixed to the first half-shell 101 with screws. The end cap 55 is located at one end of the first half-shell 101 and can be fixed to the second half-shell 102 with screws. It should be noted that the end cap 55 also constitutes part of the outer shell 10. In this case, the first half-shell 101, the second half-shell 102, and the end cap 55 together form the outer shell 10. The bracket 54 includes a generally disk-shaped base plate 541, which has a through hole through which the motor shaft 411 of the power supply 41 passes, and the second gear 53 is fixed to the portion of the motor shaft 411 that passes through the through hole. The end cap 55 is generally an open-end cylinder with a receiving space that provides sufficient receiving space for the motor shaft 411, the first gear 52, the second gear 53, and other structures protruding from the base plate 541 of the bracket 54.

[0053] In one embodiment, the end cap 55 further includes a receiving cavity 551, which communicates with the aforementioned receiving space and passes through the closed end 552 of the end cap 55. The transmission device 50 also includes a first bearing 561 and a second bearing 562, all housed within the receiving cavity 551. The first bearing 561 and the second bearing 562 are both connected to the output shaft 51 and fixed within the receiving cavity 551, providing support for the output shaft 51 and allowing it to rotate freely within the receiving cavity 551. A first connecting shaft 511 extends axially from one end of the output shaft 51, passing through the inner ring of the first bearing 561 and rotating with it. The first gear 52 is fixed to the connecting shaft. The other end of the output shaft 51 is provided with a receiving hole, and one end of a second connecting shaft 57 is fixed in the receiving hole. The execution module (e.g., the blade of a cutting machine) is fixed to the second connecting shaft 57. The second connecting shaft 57 can rotate synchronously with the output shaft 51, thereby driving the execution module to rotate.

[0054] In one embodiment, the second connecting shaft 57 includes a first shaft segment 571, a second shaft segment 572, and a third shaft segment 573 connected to each other. The end of the first shaft segment 571 is fixed in a receiving hole of the output shaft 51, and the inner ring of the second bearing 562 is fitted onto the first shaft segment 571. With this configuration, the output shaft 51 is supported by the first bearing 561 and the second bearing 562, and can rotate freely in the cavity 551 of the end cover 55, thereby driving the first shaft segment 571 connected thereto to rotate. In this embodiment, the cross-section of the third shaft segment 573 is non-circular, and the execution module is provided with a correspondingly shaped through hole, so that the execution module can fit snugly onto the third shaft segment 573, thus allowing the execution module to rotate together with the third shaft segment 573. A nut is connected to the end of the third shaft segment 573, which tightly abuts against the execution module to prevent it from disengaging from the third shaft segment 573.

[0055] In one embodiment, a groove 512 is provided on the circumferential side of the output shaft 51. The groove 512 extends parallel to the axial direction of the output shaft 51, and extends from one end of the output shaft 51 to the other end. In this embodiment, four grooves 512 are evenly provided on the circumferential side of the output shaft 51. It is understood that the number of grooves 512 can be selected according to actual needs in other embodiments, and is not limited to the aforementioned situation.

[0056] The locking structure 70 is positioned close to the actuator module (e.g., the blade of a cutting machine) to facilitate user operation when replacing / installing the actuator module. In one embodiment, the locking structure 70 includes a locking lever 71 and a spring-loaded locking button 72. The locking lever 71 is slidably connected to the housing 10, specifically to the end cover 55. The bottom end of the locking lever 71 faces the circumferential side of the output shaft 51. The spring-loaded locking button 72 is fixed to the top end of the locking lever 71. When pressure is applied, the spring-loaded locking button 72 drives the locking lever 71 from an unlocked position toward the circumferential side of the output shaft 51 until it reaches a locked position. In the locked position, the bottom end of the locking lever 71 is received in a groove 512, which prevents the output shaft 51 from rotating relative to the end cover 55. At this time, the second connecting shaft 57, coaxially connected to the output shaft 51, will not rotate, thus facilitating user replacement / installation of the actuator module.

[0057] For example, when the actuator module needs to be replaced, the user needs to unscrew the nut at the end of the third shaft segment 573. However, the freely rotating third shaft segment 573 obviously makes it difficult for the user to unscrew the nut. Therefore, the user can press the spring-loaded locking button 72. When the end of the locking lever 71 contacts the circumferential side of the output shaft 51, the user needs to manually rotate the actuator module to rotate the second connecting shaft 57, thereby causing the output shaft 51 to rotate. The purpose of this is to determine whether the end of the locking lever 71 is accommodated in a groove 512. If the end of the locking lever 71 is not accommodated in a groove 512, the user needs to continue manually rotating the actuator module until the output shaft 51 rotates to the appropriate position so that the end of the locking lever 71 enters a groove 512, thereby locking the output shaft 51 and, consequently, the third shaft segment 573. After the user releases the spring-loaded locking button 72, the spring-loaded locking button 72 returns to the unlocked position under the action of elastic force. In the unlocked position, the bottom end of the locking lever 71 leaves the groove 512. At this point, the output shaft 51 is no longer locked and can rotate freely.

[0058] In one embodiment, a protrusion 542 protrudes from the base plate 541 of the bracket 54, and two spaced-apart protrusions 543 protrude from the end of the protrusion 542. The spring-loaded locking button 72 includes a button 721 and a spring 722. A receiving hole 553 is provided on the circumferential side of the end cover 55, and a through hole for the locking rod 71 to pass through is provided at the bottom of the receiving hole 553. The button 721 is partially received in the receiving hole 553, and the portion not received in the button 721 is exposed on the circumferential side of the end cover 55. The locking rod 71 passes through the space between the two protrusions 543, and the spring 722 is fitted onto the locking rod 71. The two ends of the spring 722 abut against the button 721 and the two protrusions 543, respectively. In one embodiment, a retaining ring 711 is provided on the circumferential side of the locking rod 71. The retaining ring 711 is located on the side of the two protrusions 543 opposite to the spring 722. Figure 10 From the perspective of [unclear], the retaining ring 711 is located below the two protrusions 543, while the spring 722 is located above the two protrusions 543. The spring 722 is in a compressed state, applying a pushing force to the button 721, while the retaining ring 711 abuts against the protrusions 543, thereby preventing the locking lever 71 from disengaging from the bracket 54. With this configuration, the locking lever 71 and the button 721 can be slidably connected to the end cover 55 without disengaging from it.

[0059] refer to Figures 10 to 12 In one embodiment, the power tool 100 further includes a speed control assembly 80, which includes a knob 81, a gear 82, and a rotary potentiometer 83. The knob 81 is rotatably connected to the housing 10, and its inner sidewall is provided with teeth 811 that mesh with the gear 82. The rotary potentiometer 83 is fixed in the housing 10 and electrically connected to a controller that controls the drive device 40. The gear 82 is coaxially fixed to the rotating shaft of the rotary potentiometer 83. When the knob 81 is rotated, it drives the gear 82 to rotate, and the rotating shaft rotates synchronously with the gear 82. The controller adjusts the output of the drive device 40 according to the resistance change of the potentiometer caused by the rotation of the rotating shaft. For example, the controller can adjust the speed of the motor shaft 411 of the motor 41 according to the resistance change.

[0060] In one embodiment, the first half-shell 101 and the second half-shell 102 form a cylindrical cavity 106. The gear 82 and the rotary potentiometer 83 are disposed in the cylindrical cavity 106. The knob 81 is rotatably fitted onto the circumferential outer surface of the cylindrical cavity 106. The circumferential outer surface of the cylindrical cavity 106 is provided with a groove 1061, through which the gear 82 is partially exposed, thereby allowing the teeth 811 of the knob 81 to mesh with the gear 82. In one embodiment, a third circuit board 63 is disposed in the cylindrical cavity 106. The third circuit board 63 is electrically connected to the first circuit board 61 or the second circuit board 62, which is provided with a controller for controlling the drive device 40. The rotary potentiometer 83 is disposed on the third circuit board 63.

[0061] In one embodiment, the power tool 100 further includes a display module 90 for displaying information such as rotation speed and battery level. The display module 90 is partially housed within and detachably connected to the cylindrical cavity 106. For example, the cylindrical cavity 106 has multiple slots 1062 near its top on its circumferential outer surface, while the circumferential sidewall of the display module 90 has multiple hooks 91. These hooks 91 engage with the slots 1062 to detachably connect the display module 90 to the cylindrical cavity 106. An annular groove 107 is formed between the top of the display module 90 and the cylindrical empty cylinder 106. A protrusion 812 protrudes from the inner side of the knob 81, and this protrusion 812 is precisely received within the annular groove 107. The interaction between the protrusion 812 and the annular groove 107 prevents the knob 81 from detaching from the cylindrical empty cylinder 106 of the housing 10, and allows the knob 81 to rotate relative to the cylindrical empty cylinder 106. In one embodiment, the axis of the cylindrical empty cylinder 106 intersects the axis of the grip portion 104, and the angle between them can be 90 degrees or less. This arrangement allows the user's line of sight to naturally focus on the display module 90 when gripping the grip portion 104, facilitating the viewing of information displayed on the display module 90 during use.

[0062] In one embodiment, the housing 10 further includes a guide groove 108 surrounding the cylindrical hollow cylinder 106. A protrusion 813 protrudes from the bottom end of the knob 81, the protrusion 813 being received in the guide groove 108 and movable along it. In this embodiment, the guide groove 108 is not a continuous circular groove; it has two spaced-apart ends. When the protrusion 813 abuts against either end, it prevents the knob 81 from rotating further, thus providing feedback to the user that the knob 81 has reached its limit position.

[0063] refer to Figure 13 and Figure 14In one embodiment, the power tool 100 is a cutting machine, and its execution module is a circular blade. To prevent high-speed debris generated by the blade during the cutting process from splashing onto the user, the power tool 100 also includes a first guard 109 and a second guard 110. The first guard 109 is connected to the end cap 55, and the second guard 110 is connected to the first guard 109.

[0064] In one embodiment, a circular boss 553 protrudes from the closed end 552 of the end cap 55, and the receiving cavity 551 passes through the boss 553 (see...). Figure 11 The first protective cover 109 has a through hole 1091, through which it is fitted onto the boss 553. A first clamping plate 554 is fixed to the end face of the boss 553, and a second clamping plate 555 is fixed to the closed end 552 of the end cover 55. The first clamping plate 554 faces the inner side of the first protective cover 109, and the second clamping plate 554 faces the outer side of the first protective cover 109. An elastic gasket 556 is provided between the first clamping plate 554 and the inner side of the first protective cover 109, which is fitted onto the boss 553. The elastic gasket 556 undergoes elastic deformation due to the clamping of the first clamping plate 554 and the first protective cover 109, thereby applying a pushing force to the first protective cover 109, which makes the outer side of the first protective cover 109 tightly adhere to the second clamping plate 554. In one embodiment, the second clamping plate 554 is provided with a plurality of positioning protrusions 557, and the outer surface of the first protective cover 109 is provided with a plurality of positioning recesses 1092, the number of positioning recesses 1092 being greater than the number of positioning protrusions 557, and the plurality of positioning protrusions 557 being respectively received in the positioning recesses 1092. Due to the pushing force exerted by the elastic pad 556 on the first protective cover 109, the plurality of positioning protrusions 557 are stably locked in the positioning recesses 1092. When the user needs to adjust the first protective cover 109, he / she needs to apply external force to the first protective cover 109 to overcome the pushing force of the elastic pad 556. At this time, the first protective cover 109 can rotate relative to the end cap 55 until the first protective cover 109 rotates to the desired position. At this time, the plurality of positioning protrusions 557 have respectively entered another set of positioning recesses 1092. After the user stops applying external force to the first cover 109, the elastic pad 556 applies a pushing force to the first cover 109, causing the multiple positioning protrusions 557 to be stably locked in the set of positioning recesses 1092, thereby preventing the first cover 109 from rotating relative to the end cap 55.

[0065] In one embodiment, the second shield 110 is detachably fitted onto the circumferential outer surface of the first shield 109. The second shield 110 and the first shield 109 together can cover half of the circular blade. The arcuate inner surface formed by the second shield 110 and the first shield 109 around the edge of the circular blade can guide the debris generated when cutting the object toward the bottom surface, thereby preventing high-speed debris from flying toward the user.

[0066] In one embodiment, the two circumferential ends of the second cover 110 are provided with cantilevered spring pieces 111, and the inner surface of the spring pieces 111 is provided with hooks 112. The two hooks 112 are respectively engaged with the circumferential ends of the first cover 109, thereby detachably fitting the second cover 110 onto the circumferential outer surface of the first cover 109.

[0067] refer to Figure 2 The electronic components on the first circuit board 61 generate more heat during operation than the electronic components on the second circuit board 62. In other words, the electronic components that generate more heat during operation are arranged on the first circuit board 61, while the electronic components that generate less heat during operation are arranged on the second circuit board 62. This arrangement is intended to provide the power tool 100 with good heat dissipation capabilities, as will become clear and obvious from the following description. In one embodiment, the first circuit board 61 is provided with multiple heat-generating components such as metal-oxide-semiconductor field-effect transistors (MOSFETs). The MOSFETs are used to control the motor 41, and their placement between the motor 41 and the end of the head 103 also helps to reduce the wiring connection path between the first circuit board 61 and the motor 41. The second circuit board 62 is provided with a microcontroller (MCU) and charge / discharge management circuitry, etc.

[0068] refer to Figure 10 The drive unit 40 also includes a fan 42 coaxially connected to the motor shaft 411 of the motor 41. The fan 42 faces the first end of the motor 41 and is located between the drive unit 40 and the transmission device 50. The fan 42 can rotate with the motor shaft 411. The rotation of the fan 42 drives the airflow through the motor 41, thereby carrying away the heat generated by the motor 41 during operation. That is, due to the presence of the fan 42, an airflow channel is formed in the head 103 of the housing 10. Therefore, an air outlet 1031 is formed at the end of the head 103 away from the fan 42 (see...). Figure 3 The airflow passing through the motor 41 eventually leaves the housing 10 through the air outlet 1031 and is discharged to the outside of the housing 10.

[0069] In one embodiment, the first circuit board 61 faces the second end of the motor 41 opposite to the first end and is located between the ends of the motor 41 and the head 103. That is, the first circuit board 61 is located near and directly opposite the air outlet 1031 in the airflow channel in the head 103, so that the airflow flowing through the motor 41 will flow through the first circuit board 61, thereby carrying away the heat generated by the first circuit board 61 during operation. The airflow is finally discharged to the outside of the housing 10 through the air outlet 1031.

[0070] In one embodiment, the head 103 has a circular cross-section, and the first circuit board 61 is also approximately circular. This allows for full utilization of the internal space of the head 103 and maximizes the area of ​​the first circuit board 61, thereby facilitating heat dissipation and the placement of numerous electronic components. A through-hole is provided at the center of the first circuit board 61, which further promotes airflow. The first circuit board 61 can be fixed to the second end of the motor 41 with screws.

[0071] In one embodiment, the first circuit board 61 is also connected to a heat sink 64 (see Figure 10 The first circuit board 61 has electronic components that generate a lot of heat during operation mounted on its front side. A heat sink 64 is attached to the back of the first circuit board 61, and the heat sink 64 faces the air outlet 1031. The heat sink 64 can be fixed to the first circuit board 61 with screws or glue. The heat sink 64 facilitates the dissipation of heat generated by the electronic components on the first circuit board 61.

[0072] The reason why the electronic components that generate low heat during operation are located on the second circuit board 61 in the grip 104 is that the circumferential side of the grip 104 is covered with a decorative shell 105. Providing heat dissipation holes on the decorative shell 105 would affect the aesthetics. Since the electronic components on the second circuit board 61 generate low heat during operation, not providing heat dissipation holes has a minimal impact on the heat dissipation of the power tool 100. This way, both aesthetic appeal and heat dissipation requirements can be met simultaneously.

[0073] By placing the electronic components on two physically independent circuit boards, first 61 and second 62, it is beneficial to make full use of the space inside the housing 10 and to distribute the electronic components in a dispersed manner, thereby reducing the distribution density of the electronic components on the first 61 and second 62, which is beneficial for heat dissipation. Placing the first 61 near the air outlet 1031 is beneficial for heat dissipation, and placing the first 61 downstream of the airflow channel and near the air outlet 1031 can further improve the heat dissipation efficiency.

[0074] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this utility model.

Claims

1. A power tool, characterized in that, include: shell; First circuit board; and Second circuit board; The first circuit board and the second circuit board are both located inside the housing. The electronic components on the first circuit board generate more heat when working than the electronic components on the second circuit board. The first circuit board and the second circuit board are located in different positions within the housing.

2. The power tool according to claim 1, characterized in that, The housing includes a head and a grip portion connected to the head, a first circuit board disposed in the head, and a second circuit board disposed in the grip portion.

3. The power tool according to claim 2, characterized in that, It also includes a drive unit disposed in the head, the drive unit including a motor and a fan, the fan facing a first end of the motor, and the first circuit board facing a second end of the motor opposite to the first end.

4. The power tool according to claim 3, characterized in that, The first circuit board is located between the motor and the end of the head, the end of which is provided with an air outlet.

5. The power tool according to claim 2, characterized in that, An air outlet is formed at the end of the head, and the first circuit board is positioned opposite the air outlet.

6. The power tool according to claim 2, characterized in that, The head and the gripping part are T-shaped.

7. The power tool according to claim 1, characterized in that, The first circuit board includes multiple metal-oxide-semiconductor field-effect transistors.

8. The power tool according to claim 2, characterized in that, The head has a circular cross-section, and the first circuit board is circular.

9. The power tool according to claim 1, characterized in that, It also includes a heat sink connected to the first circuit board.

10. The power tool according to claim 1, characterized in that, It also includes a drive device, a controller, and a speed control assembly disposed in the housing. The controller is electrically connected to the drive device. The speed control assembly includes a knob, a gear, and a rotary potentiometer. The knob is rotatably connected to the housing. The inner sidewall of the knob is provided with teeth that mesh with the gear. The rotary potentiometer is fixed in the housing and electrically connected to the controller. The gear is coaxially fixed to the rotating shaft of the rotary potentiometer. When the knob is rotated, it can drive the gear to rotate. The rotating shaft can synchronously follow the rotation of the gear. The controller adjusts the output of the drive device according to the resistance change of the potentiometer caused by the rotation of the rotating shaft.

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