Electric working machine and method for manufacturing stator of motor for electric working machine

Abstract

The present invention provides a method for manufacturing a stator of an electric working machine and a motor for an electric working machine. The stator (25) of the electric drill has: a stator core (27); a first insulator (28) which is held by the stator core (27); a plurality of windings (30) which are wound on the stator core (27) via the first insulator (28); a plurality of welding terminals (50) which are held by the first insulator (28) and are respectively connected to each winding (30); and a short-circuit component (32) which has a first sheet metal component (68A) to a third sheet metal component (68C) which can be connected to each welding terminal (50), and the short-circuit component (32) is fixed to the first insulator (28) by screws (76) in a detachable manner, whereby each welding terminal is respectively connected to the first sheet metal component to the third sheet metal component. According to the present invention, the stator and the controller can be easily electrically connected and separated, and the production efficiency and maintainability are excellent.

Description

Technical Field

[0001] The present invention relates to an electric working machine provided with a brushless motor as a driving source, and a method for manufacturing a stator of a motor for the electric working machine. Background Art

[0002] As is well known, electric working machines such as electric tools and gardening tools are equipped with brushless motors as driving sources. In particular, as disclosed in Patent Document 1, the present applicant has disclosed the following invention: in order to obtain a motor that can flow a large current even though it is small and space-saving, a welding terminal that is welded to the windings between windings is provided on the stator of the brushless motor, and a short-circuit component having a sheet metal component connected to a power line from a controller is used, the short-circuit component is assembled to the stator and the sheet metal component is connected to the welding terminal, so that the windings between the windings are short-circuited.

[0003] [Prior art literature]

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Publication No. 2015-56953 Summary of the invention

[0006] [Technical problem to be solved by the invention]

[0007] In the brushless motor of the prior art, the connection between the welding terminal and the short-circuit component is made by soldering. Therefore, there is a difficulty in inspecting the production process. In addition, as another aspect, since the quality of the connection also needs to be confirmed based on visual experience, quality deviation may occur.

[0008] On the other hand, from another perspective, when one of the stator and the controller fails, it is necessary to first remove the solder and then take out and separate both the stator and the controller, which takes a lot of effort and time for maintenance.

[0009] Therefore, an object of the present invention is to simplify the electrical connection and disconnection between a stator and a controller. More specifically, an object of the present invention is to provide an electric working machine having excellent productivity and maintainability and a method for manufacturing a stator of a motor for an electric working machine.

[0010]

Methods used to solve technical problems

[0011] In order to achieve the above-mentioned purpose, the invention recorded in technical solution 1 is an electric working machine, characterized in that it includes a motor having a stator and a rotor, the stator including: a stator core; an insulator, which is retained on the stator core; a plurality of windings, which are wound on the stator core via (through) the insulator; a plurality of winding terminals, which are retained on the insulator and are respectively connected to each winding; and a short-circuit component, which has a plurality of lead terminals that can be connected to each winding terminal, and the short-circuit component is fixed to the insulator in a detachable manner by screws, thereby each winding terminal is respectively connected to each lead terminal.

[0012] In the structure of claim 1, the invention described in claim 2 is characterized in that the short-circuit member is fixed to the insulator by connecting each winding terminal and each lead terminal with screws.

[0013] In the structure of claim 1 or 2, the invention described in claim 3 is characterized in that the short-circuit member has a resin insulating portion for holding the plurality of lead terminals, and the insulating portion is fixed to the insulator by the second screw.

[0014] In the structure of technical solution 3, the invention described in technical solution 4 is characterized in that the electric working machine has a rotor and a sensor circuit substrate, wherein the rotor is arranged on the inner side of the stator core; the sensor circuit substrate detects the position of the permanent magnet arranged on the rotor, and the sensor circuit substrate is fixed between the insulator and the short-circuit component by a second screw.

[0015] In order to achieve the above-mentioned purpose, the invention recorded in technical solution 5 is an electric working machine, characterized in that it includes a motor having a stator and a rotor, and the stator includes: a stator core; an insulator, which is retained in the stator core; a winding, which is wound on the stator core via (through) the insulator; a winding terminal, which is retained in the insulator and connected to the winding, and which is formed with an internal thread; and a lead terminal, which can be connected to the winding terminal, and the lead terminal is fixed to the winding terminal by a screw screwed into the internal thread, thereby making the winding terminal and the lead terminal conductive.

[0016] In the structure of claim 5, the invention described in claim 6 is characterized in that the internal thread is formed integrally with the winding terminal.

[0017] In order to achieve the above-mentioned purpose, the invention recorded in Technical Solution 7 is a method for manufacturing a stator of an electric motor for an electric working machine, characterized in that, in an electric motor for an electric working machine having a stator and a rotor, the method for manufacturing the stator includes a first step, a second step and a third step, wherein, in the first step, the winding is wound while the insulator is maintained on the stator core; in the second step, the winding wire is fused to the winding terminal maintained on the insulator; in the third step, the lead terminal for connecting the lead wire is threadedly fixed on the winding terminal, thereby making the lead terminal and the winding terminal conductive.

[0018] In the structure of claim 7, the invention described in claim 8 is characterized in that the winding terminal has an internal thread for screw fixing in an integrally formed manner.

[0019] [Effects of the invention]

[0020] According to the present invention, the conduction between the terminals is achieved by screw fixing, thereby stabilizing the production operation. As a result, the operation time is also shortened, and the production efficiency can be improved. In addition, in the case that one of the stator and the controller fails, the two can be easily separated by removing the screws, thereby facilitating the maintenance of one of the two, and thus having excellent maintainability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an overall picture of the electric drill.

[0022] Figure 2 It is a central longitudinal section view of the electric drill.

[0023] Figure 3 This is a partial enlarged view of the brushless motor.

[0024] Figure 4 This is a perspective view of the stator as seen from the front.

[0025] Figure 5 This is a perspective view of the stator from the rear.

[0026] Figure 6 These are explanatory diagrams of a stator, wherein (A) indicates a front view, (B) indicates a side view, and (C) indicates a back view.

[0027] Figure 7 This is a three-dimensional exploded view of the stator.

[0028] Figure 8 It is an explanatory diagram of the first insulator, wherein (A) shows a front view, (B) shows a bottom view, and (C) shows an AA cross section.

[0029] Fig. 9The figures are perspective views of the welding terminal, wherein (A) shows a perspective view viewed from the clamping piece side, and (B) shows a perspective view viewed from the opposite side of the clamping piece.

[0030] Fig.10 These are explanatory diagrams of a sensor circuit substrate, wherein (A) indicates a front view, (B) indicates a side view, (C) indicates a rear view, and (D) indicates a bottom view.

[0031] Fig.11 This is an exploded perspective view of the sensor circuit board.

[0032] Fig.12 The figures are perspective views of the short-circuit component, wherein (A) is a perspective view when viewed from the front, and (B) is a perspective view when viewed from the rear.

[0033] Fig.13 These are explanatory diagrams of a short-circuit component, wherein (A) shows a front view, (B) shows a side view, and (C) shows a back view.

[0034] Fig.14 It is a three-dimensional exploded view of the short-circuit components.

[0035] Fig.15 These are explanatory diagrams of the first to third sheet metal components, wherein (A) indicates a front view, (B) indicates a side view, (C) indicates a back view, and (D) indicates a bottom view.

[0036] Fig.16 is a partial cross-sectional view of the electric drill at the first insulator portion.

[0037] Fig.17 This is a perspective view of the stator according to the modification example as viewed from the front.

[0038] Fig.18 This is a perspective view of the stator according to the modification example as viewed from the front.

[0039] Fig.19 This is a perspective view of the stator according to the modification example as viewed from the front.

[0040] Fig. 20 These are explanatory diagrams of a stator according to a modified example, wherein (A) shows a front view, (B) shows a side view, and (C) shows a back view.

[0041] Fig.21 This is a central longitudinal sectional view of a stator according to a modification example.

[0042] Fig. 22 This is a central longitudinal sectional view of a grinding machine using a stator according to a modified example.

[0043] [Description of Reference Numerals]

[0044] 1: electric drill; 2: main body; 3: handle; 4: battery installation part; 6: main body shell; 7, 7A: brushless motor; 11: spindle; 25, 25A: stator; 26: rotor; 27: stator core; 28: first insulator; 29: second insulator; 30: winding; 30a: magnetic wire; 31, 31A: sensor circuit substrate; 32: short-circuit component; 37: holding part; 38: first protrusion; 39: second protrusion; 40: threaded boss; 50: welding terminal; 51: clamp Holding piece; 52: Insertion piece; 53: Nut portion; 54: Internal thread; 55: Base plate portion; 56: Rotation detection element; 57: Resin portion; 60: Signal line; 65: Insulating portion; 66: Boss; 68A: First sheet metal component; 68B: Second sheet metal component; 68C: Third sheet metal component; 69A~69C: Short-circuit piece; 72: Power line; 75, 76: Screws; 85: Rotating shaft; 87: Permanent magnet; 111: Controller; 112: Control circuit substrate; 120: Grinder. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0046] (Overall description of the electric drill)

[0047] Figure 1 This is an overall view of a cordless drill as an example of an electric working machine. Figure 2 The electric drill 1 has a T-shaped body 2 extending in the front-rear direction and a handle 3 extending downward, and a battery pack 5 serving as a power source is mounted on a battery mounting portion 4 formed at the lower end of the handle 3 .

[0048] The shell of the main body 2 is formed by assembling the front shell 9 accommodating the coupling mechanism 10 and the main shaft 11 at the front of the cylindrical main shell 6 accommodating the brushless motor 7 and the planetary gear reduction mechanism 8 from the front using screws 12, 12..., and assembling the rear cover 13 at the rear of the main shell 6 at two upper and lower positions from the rear using screws 14, 14.

[0049] A mode switching ring 15 and a coupling adjustment ring 16 are provided in front of the front housing 9, and a chuck 17 is coaxially fixed to the front end of the spindle 11 in front of the coupling adjustment ring 16. The handle 3 is provided continuously with the main housing 6, and they are formed by assembling the left and right split housings 6a and 6b with screws 18, 18... A switch 19 for making a trigger switch 20 protrude forward is accommodated in the upper part of the handle 3, and a forward and reverse switching button 21 for motor rotation is provided on the upper side of the switch 19. A lamp 22 is provided above the trigger switch 20, and the lamp 22 has an LED for illuminating the front of the chuck 17.

[0050] (Description of brushless motor)

[0051] The brushless motor 7 housed in the rear portion of the main body housing 6 is an inner rotor type consisting of a stator 25 and a rotor 26. Figure 3 to Figure 6 As shown, the stator 25 has: a cylindrical stator core 27, which is formed by a plurality of laminated steel plates; a first insulator 28 and a second insulator 29, which are respectively arranged on the axial front and rear end surfaces of the stator core 27; and 6 windings 30, 30..., which are wound on the stator core 27 separated by the first insulator 28 and the second insulator 29.

[0052] Here, the first insulator 28 is arranged on the front side, and the sensor circuit board 31 and the short-circuit member 32 are mounted on the first insulator 28 .

[0053] Also like Figure 7 As shown, first, the stator core 27 has six teeth 33, 33, ... protruding toward the axial center side, and six core slots 34, 34, ... are formed between the teeth 33, 33.

[0054] Also like Figure 8 As shown, the first insulator 28 is an annular integrally formed part having the same diameter as the stator core 27, and has six protrusions 35, 35 ... formed on the inner circumference side, and the six protrusions 35, 35 ... protrude toward the axial center side and are located at a position where the teeth 33 of the stator core 27 extend forward in a continuous shape. In addition, six fitting parts 36, 36 ... that fit into the core slots 34 of the stator core 27 are protrudingly provided on the back side of the first insulator 28, and six sets of holding parts 37, 37 ... of the welding terminals 50 are protrudingly provided on the outer circumference side at positions corresponding to the fitting parts 36 on the front surface. The retaining portion 37 is a group consisting of a first protrusion 38 that is U-shaped when viewed from the front and a second protrusion 39 that is C-shaped when viewed from the front, arranged at a specified interval in a manner such that the openings of the U and C face each other, and between each retaining portion 37, 37, a pair of four threaded bosses 40, 40... are provided, separated to the left and right and protruding up and down, respectively. The four threaded bosses 40, 40... have a threaded hole in the center and a flange portion 41 extends at the root.

[0055] A pair of concave portions 42, 42 are formed on the left and right sides of the first insulator 28, and a pair of triangular first notches 43, 43 are formed on the upper and lower sides of the concave portions 42, 42. A quadrangular second notch 44 is formed in the upper center of the first insulator 28.

[0056] The second insulator 29 is also annular with the same diameter as the stator core 27, and has six protrusions 35, 35 ... formed on its inner circumference, which protrude toward the axial center and are located at a position where the teeth of the stator core 27 extend continuously to the rear. In addition, six fitting parts 36, 36 ... that fit into the core slots 34 of the stator core 27 are protrudingly provided on the front surface side of the second insulator 29. In addition, curved lateral notch parts 45, 45 are formed on the left and right sides of the second insulator 29, and a chamfered part 46 cut into a straight line is formed in the upper and lower centers.

[0057] Furthermore, each holding portion 37 of the first insulator 28 holds a welding terminal 50. Fig. 9 As shown, the welding terminal 50 has a clamping piece 51 formed by folding a strip of metal in half, and is used to weld the magnetic wire (winding wire) 30a of the winding 30. In addition, an insertion piece 52 is formed on one of the left and right side edges of the metal, and the first protrusion 38 of the holding part 37 is inserted from the front, and a cylindrical nut part 53 is formed on the other side to be inserted from the front into the second protrusion 39 of the holding part 37. The nut part 53 is a part in which the metal is curled into a C shape and an internal thread 54 is formed on the inner circumference.

[0058] When the insertion piece 52 is inserted into the first protrusion 38 and the nut portion 53 is inserted into the second protrusion 39 with the clamping piece 51 facing radially outward, each welding terminal 50 is held on a concentric circle in a posture parallel to the axial direction of the first insulator 28 .

[0059] The windings 30, 30 ... are wound around the teeth 33 of the stator core 27 via the protrusions 35 of the first insulator 28 and the second insulator 29, but one magnetic wire is sequentially wound around the teeth 33 adjacent in the circumferential direction. The magnetic wire 30a connecting the windings 30, 30 is welded while being wound around the outside of the holding portion 37 and clamped by the clamping pieces 51 of the welding terminal 50, thereby being electrically connected to the welding terminals 50.

[0060] like Fig.10 and Fig.11 As shown, the sensor circuit substrate 31 is composed of a substrate portion 55 and a resin portion 57 covering the substrate portion 55, wherein the substrate portion 55 is equipped with three rotation detection elements 56, 56... that detect the position of the permanent magnet 87 provided on the rotor 26 and output a rotation detection signal.

[0061] The substrate portion 55 is in the shape of a ring having an outer diameter that is accommodated inside the holding portion 37. Four protrusions 58, 58 ... are provided on the outer periphery of the substrate portion 55 to protrude radially outward. The four protrusions 58, 58 ... have through holes 59 corresponding to the threaded bosses 40, 40 ... of the first insulator 28. The threaded bosses 40 are passed through the through holes 59, and the protrusions 58 are abutted against the flange portion 41 and positioned on the front surface of the first insulator 28. A lead-out portion 61 for collectively leading out the signal lines 60, 60 ... of the rotation detection element 56 is provided at the center of the lower portion of the substrate portion 55. A plurality of notches 62, 62 ... are formed on the outer periphery of the substrate portion 55 except for the protrusions 58 and the lead-out portion 61.

[0062] In addition, the resin portion 57 is insert-molded in the substrate portion 55, covers the surface, back surface, and lead portion 61 of the substrate portion 55 except the protrusion 58, and is integrated with the substrate portion 55. The notch 62 of the substrate portion 55 is buried in the resin portion 57, thereby improving the bonding force with the resin portion 57. A plurality of thick-walled portions 63, 63, ... extending in the radial direction are formed on the rear surface of the resin portion 57, which can ensure the rigidity of the sensor circuit substrate 31 and distinguish the surface and back surface.

[0063] like Fig.12 and Fig.13 As shown in the figure, the short-circuit component 32 is annular with a diameter substantially the same as that of the sensor circuit substrate 31, and four cylindrical bosses 66, 66 ... are protruded in an integral manner on the outer periphery of the resin insulating portion 65, and each threaded boss 40 of the first insulator 28 can be engaged with the four cylindrical bosses 66, 66 ... from the rear. A protruding piece 67, 67 ... is formed toward the rear at the root side of the rear surface of each boss 66, and the sensor circuit substrate 31 can be coaxially held inside each protruding piece 67.

[0064] In addition, if Fig.14 As shown, the insulating part 65 is insert-molded with three sheet metal parts, namely, the first sheet metal part 68A, the second sheet metal part 68B, and the third sheet metal part 68C. Among these sheet metal parts, the first sheet metal part 68A is bent into a U-shape, and a pair of short-circuit pieces 69A, 69A having through holes 70 are formed at its left and right ends, and the short-circuit pieces 69A, 69A are respectively extended outward in the left and right directions. The second sheet metal part 68B is formed in an arc shape, and a pair of short-circuit pieces 69B, 69B having through holes 70 are formed on its lower right side and upper left side. The third sheet metal part 68C is formed in an arc shape, and a pair of short-circuit pieces 69C, 69C having through holes 70 are formed on its lower left side and upper right side.

[0065] like Fig.15As shown, these three sheet metal parts 68A to 68C are insert-molded in the insulating portion 65 in a state where they overlap on concentric circles in a non-contact state, with the second sheet metal part 68B being arranged in front of the left side of the first sheet metal part 68A and the third sheet metal part 68C being arranged in front of the right side of the first sheet metal part 68A.

[0066] Accordingly, six short-circuit pieces 69A to 69C electrically connected to each other diagonally are radially protruded from the outer periphery of the insulating portion 65 , and the six short-circuit pieces 69A to 69C correspond to the welding terminals 50 held on the first insulator 28 .

[0067] In addition, a connection piece 71 is formed by bending forward at the center of the lower end of the first sheet metal part 68A, and the connection piece 71 is located between the short-circuit pieces 69B and 69C on the lower sides of the second sheet metal part 68B and the third sheet metal part 68C, and the power lines 72, 72 ... (leads) of the U phase, V phase and W phase are spot welded to the rear surface of the connection piece 71 and the front surface of the short-circuit pieces 69B and 69C on the lower sides of the second sheet metal part 68B and the third sheet metal part 68C. A plurality of guide ribs 73, 73 ... are formed in parallel on the lower back side of the insulating part 65 in the vertical direction, and the guide ribs 73, 73 ... separate the power lines 72 from each other and guide and hold the power lines 72 downward from the sheet metal parts 68A to 68C.

[0068] Further, exposure holes 74 , 74 . . . are formed on the front and rear surfaces of the insulating portion 65 to expose the sheet metal members 68A to 68C and improve heat dissipation.

[0069] (Description of the manufacturing process of the stator)

[0070] Next, the manufacturing process of the above-mentioned stator will be described.

[0071] First, the first insulator 28 and the second insulator 29 are molded, and the windings 30 are sequentially wound around the teeth 33 in a single row as described above on the stator core 27 holding the welding terminals 50 on the holding portions 37 .

[0072] Next, in the first insulator 28 , the magnet wire 30 a between the windings 30 , 30 is welded to each welding terminal 50 .

[0073] On the other hand, on the rear surface of the short-circuit member 32 , the protrusions 58 are aligned with and overlapped with the bosses 66 of the insulating portion 65 from behind, and the sensor circuit board 31 is held by the protruding piece 67 .

[0074] Next, four screws 75 , 75 . . . that penetrate through the bosses 66 and the protrusions 58 from the front are screwed to the screw bosses 40 of the first insulator 28 , thereby fixing the sensor circuit board 31 and the short-circuit member 32 to the first insulator 28 .

[0075] Next, when six screws 76 , 76 . . . passing through the short-circuiting pieces 69A to 69C from the front are screwed to the internal threads 54 of the nut portions 53 of the welding terminals 50 , the short-circuiting pieces 69A to 69C are fixed by the screws 76 and conduction is established.

[0076] Thus, the stator 25 can be obtained in which the welding terminals 50, 50 located at the central symmetrical positions are short-circuited via the first sheet metal member 68A to the third sheet metal member 68C. In the stator 25, the six welding terminals 50, 50 ... electrically connected to the magnetic wires 30a, 30a ... between the six windings 30, 30 ... sequentially wound around the stator core 27 are electrically connected to each other at the diagonal points via the first sheet metal member 68A to the third sheet metal member 68C, forming a so-called triangular connection of parallel windings.

[0077] like Figure 3 As shown, the outer periphery of the stator core 27 is held by support ribs 80, 80, ..., and as shown in FIG. Fig.16 As shown, the protrusions 81, 81 protruding from the inner surfaces of the split shells 6a, 6b are respectively engaged with the recesses 42 formed on the side surfaces of the first insulator 28, whereby the stator 25 manufactured as described above is housed in a state of being positioned axially and circumferentially, wherein the support ribs 80, 80...are respectively protruding from the inner surfaces of the split shells 6a, 6b of the main shell 6 along the circumferential direction.

[0078] When the motor is assembled to the housing of other electric tools, the first notch portion 43 , the second notch portion 44 , the lateral notch portion 45 and the chamfered portion 46 can also be used.

[0079] (Explanation of other structural parts)

[0080] On the other hand, Figure 2 , 3 As shown, the rotor 26 includes a rotating shaft 85 located at the axis center, a cylindrical rotor core 86 arranged around the rotating shaft 85 , and four plate-shaped permanent magnets 87 , 87 . . . buried in the rotor core 86 .

[0081] The rear end of the rotating shaft 85 is pivotally supported by a bearing 88 held by the rear cover 13, and a centrifugal fan 89 is installed in the front portion thereof. A plurality of exhaust ports 90, 90 ... are formed on the left and right sides of the rear cover 13, and a plurality of air inlets 91, 91 ... are formed on the left and right sides of the main body shell 6. Figure 1 ).

[0082] In addition, Figure 2 , 3In the figure, a transmission mechanism box 92 for accommodating the planetary gear reduction mechanism 8 is arranged in front of the brushless motor 7, and the front end of the rotating shaft 85 passes through the end cover 93 at the rear end of the closed transmission mechanism box 92 and is pivotally supported by a bearing 94 on the end cover 93, and a pinion 95 is fixed to the front end of the rotating shaft 85.

[0083] The planetary gear reduction mechanism 8 is a known structure in which three planetary carriers 97, 97 ... supporting a plurality of planetary gears 98, 98 ... revolving in the internal gears 96, 96 ... are arranged side by side in the axial direction, and the pinion 95 is meshed with the first-stage planetary gear 98. In addition, the second-stage internal gear 96 (hereinafter, marked as 96A for distinction) is fixed in the transmission mechanism case 92 and is arranged to be able to move forward and backward in the axial direction between a forward position and a reverse position, wherein the forward position is a position where the second-stage planetary gear 98 revolves, and the reverse position is a position where the second-stage internal gear 96A is meshed with the second-stage planetary gear 98 and the first-stage planetary carrier 97 at the same time, so that the planetary carrier 97 and the planetary gear 98 rotate integrally and the second-stage reduction is canceled. The speed switching ring 100 is connected to the internal gear 96A via a pin 99, and the locking protrusion 101 at the upper end of the speed switching ring 100 is connected to the speed switching button 103 on the upper surface of the main body case 6 via front and rear coil springs 102, 102. Therefore, by sliding the speed switch button 103 forward and backward, the internal gear 96A moves forward and backward via the speed switch ring 100, thereby selecting a low speed mode in the forward position and a high speed mode in the reverse position. The third-stage planetary carrier 97 is connected to the main shaft 11 pivotally supported by the front and rear bearings 104, 104 in the transmission mechanism case 92 so as to be rotatable as a whole.

[0084] In the coupling mechanism 10, the internal gear 96 (hereinafter, marked as 96B for distinction) meshing with the third-stage planetary gear 98 is held in a rotatable manner, and a pin (not shown) that is locked to the internal gear 96B from the front is provided on the transmission mechanism case 92 in front of it, and a coil spring 106 that presses the pin to the internal gear 96B via a washer 105 is installed on the outer periphery of the front end of the transmission mechanism case 92. The axial length of the coil spring 106 is changed by the retaining ring 107 that is threaded in the front and rear directions by the rotation operation of the coupling adjustment ring 16, thereby changing the pressing force on the internal gear 96B. Therefore, when the mode switching ring 15 is in the drive mode position, when the load in the rotation direction applied to the internal gear 96B via the main shaft 11 exceeds the pressing force of the coil spring 106, the internal gear 96B releases the locking of the pin and idly rotates, thereby disconnecting the torque transmission to the main shaft 11. On the other hand, when the mode switching ring 15 is in the drill mode position, the lock member 108 directly presses the washer 105 to prevent the internal gear 96B from idling, so the coupling does not operate and the main shaft 11 always rotates.

[0085] On the other hand, a terminal block 110 is provided in the battery mounting portion 4 to which the battery pack 5 is slidably mounted from the front, and a controller 111 is provided on the upper side thereof in parallel with the terminal block 110. The controller 111 is formed by accommodating a control circuit substrate 112 equipped with a microcomputer and switch elements (not shown) in a disk-shaped housing 113. A display portion 114 for displaying the mode, the remaining capacity of the battery, etc. is provided on the upper front surface of the control circuit substrate 112, and the display portion 114 is exposed on the upper surface of the battery mounting portion 4.

[0086] (Description of the action of the electric drill)

[0087] In the electric drill 1 configured as described above, when the trigger switch 20 is pressed, the switch 19 is turned on, and the brushless motor 7 is driven by the power of the battery pack 5. That is, the microcomputer of the control circuit board 112 obtains the rotation detection signal indicating the position of the permanent magnet 87 of the rotor 26 output from the rotation detection element 56 of the sensor circuit board 31, and obtains the rotation state of the rotor 26, and controls the on / off of each switch element according to the obtained rotation state, and rotates the rotor 26 by sequentially passing current to each winding 30 of the stator 25. Therefore, the rotating shaft 85 rotates, and the rotation reduced by the planetary gear reduction mechanism 8 is transmitted to the main shaft 11, so that the chuck 17 rotates. By operating the mode switching ring 15, a driving mode and a drilling mode can be selected, wherein the driving mode is a mode in which the coupling mechanism 10 that transmits rotation at a specified torque is disconnected and functions, and the drilling mode is a mode in which the coupling mechanism 10 does not function. By operating the coupling adjustment ring 16, the torque at which the coupling mechanism 10 works in the driving mode can be adjusted.

[0088] Furthermore, since each phase of the winding 30 of the brushless motor 7 is connected in parallel with each other, the winding resistance is reduced and a large current can flow. This parallel connection can be achieved by using the short-circuit component 32, so it can be achieved in a space-saving manner. That is, Figure 6 As shown in (B), since the short-circuit component 32 is assembled so as not to protrude forward from the tip of the first protrusion 38 of the holding portion 37, the space in front of the sensor circuit board 31 can be effectively utilized to install the short-circuit component 32, thereby maintaining a compact structure.

[0089] Furthermore, since six windings 30 are wound with one magnet wire, all windings 30 can be wound in one process, and there is no need for connecting wires to connect diagonal windings 30 and 30. The absence of connecting wires also leads to compactness.

[0090] In addition, since the sensor circuit board 31 is provided on one end side of the brushless motor 7 and power is supplied to the winding 30 from the same side, a large current can be supplied while maintaining compactness. In particular, since the sensor circuit board 31 and the short-circuit component 32 are provided in parallel in sequence on one end side of the stator 25, the sensitivity of the sensor is excellent.

[0091] (Effects of the invention related to screw fixing of welding terminal and sheet metal component)

[0092] The electric drill 1 of the above-mentioned method is constructed to include: a stator core 27; a first insulator 28 (insulator), which is retained by the stator core 27; a plurality of windings 30, 30..., which are wound on the stator core 27 via the first insulator 28; a plurality of welding terminals 50, 50... (winding terminals), which are retained by the first insulator 28 and connected to each winding 30; and a short-circuit component 32, which has a first sheet metal component 68A to a third sheet metal component 68C (a plurality of lead terminals) that can be connected to each welding terminal 50, and the short-circuit component 32 is fixed to the first insulator 28 by screws 76, 76... in a detachable manner, thereby each welding terminal 50 is respectively connected to the first sheet metal component 68A to the third sheet metal component 68C.

[0093] Therefore, the production operation can be stabilized without welding, and the operation time can be shortened, thereby improving the production efficiency. In addition, even if one of the stator 25 and the controller 111 fails, the two can be easily separated by removing the screws 75 and 76, thereby making it easy to repair one of the two, and thus having excellent maintainability. In addition, it becomes a reasonable structure that can electrically connect the welding terminal 50 and the first sheet metal member 68A to the third sheet metal member 68C by the screw 76, and can also fix the short-circuit member 32 and the first insulator 28.

[0094] In particular, here, the short-circuit component 32 is fixed to the first insulator 28 by connecting each welding terminal 50 and the first to third sheet metal components 68A to 68C with screws 76, 76, ..., thereby achieving a reasonable structure in which conduction between the terminals and fixation of the short-circuit component 32 can be simultaneously performed with the screws 76.

[0095] In addition, the short-circuit component 32 has a resin insulating portion 65 for holding the first sheet metal component 68A to the third sheet metal component 68C, and the insulating portion 65 is fixed to the first insulator 28 by a screw 75 (second screw). Therefore, the first sheet metal component 68A to the third sheet metal component 68C can be stably held and the short-circuit component 32 can also be reliably fixed.

[0096] In addition, it has a rotor 26 arranged on the inner side of the stator core 27, and a sensor circuit substrate 31 for detecting the position of a permanent magnet 87 arranged on the rotor 26. The sensor circuit substrate 31 is fixed between the first insulator 28 and the short-circuit component 32 by screws 75, so the sensor circuit substrate 31 can also be easily fixed by using the screws 75 for fixing the short-circuit component 32.

[0097] On the other hand, in the electric drill 1 of the above-mentioned embodiment, it is constructed to have: a stator core 27; a first insulator 28 (insulator), which is retained by the stator core 27; a winding 30, which is wound on the stator core 27 via the first insulator 28; a welding terminal 50 (winding terminal), which is retained by the first insulator 28, is connected to the winding 30, and is formed with an internal thread 54; and a first sheet metal component 68A to a third sheet metal component 68C (lead terminal), which can be connected to the welding terminal 50, and the first sheet metal component 68A to the third sheet metal component 68C are fixed to the welding terminal 50 by using a screw 76 screwed into the internal thread 54, thereby making the welding terminal 50 and the first sheet metal component 68A to the third sheet metal component 68C conductive.

[0098] Therefore, welding is not required and the production operation can be stabilized, and the operation time is also shortened, thereby improving the production efficiency. In addition, even if one of the stator 25 and the controller 111 fails, the two can be easily separated by removing the screws 75 and 76, thereby making it easy to repair one of the two, and thus having excellent maintainability. In addition, since the internal thread 54 is formed on the welding terminal 50, the number of parts can be reduced, thereby suppressing the cost increase.

[0099] In particular, here, since the internal thread 54 is formed integrally with the welding terminal 50 , a nut is not required, and further cost reduction can be expected.

[0100] In addition, the shape and configuration of the sheet metal component and the form of the short-circuit component are not limited to the above forms, but can be appropriately changed. The short-circuit component can also be C-shaped or semicircular instead of annular. In addition, the sheet metal component can also be assembled on the surface of the short-circuit component without insert molding.

[0101] The shape of the welding terminal is not limited to the above-mentioned one. For example, instead of forming the internal thread into a curled nut portion, a separate nut may be welded.

[0102] In addition, the arrangement of the welding terminal is not limited to the above-mentioned manner, and it may be arranged at the position of the teeth, for example. Similarly, the arrangement of the threaded boss is not limited to the above-mentioned manner, and it may be arranged between the teeth, for example.

[0103] In the above embodiment, the screws 76 are used to connect and conduct the welding terminal 50 to the sheet metal members 68A to 68C. However, if the conduction between the terminals can be ensured by fixing the short-circuit member 32 with the screws 75 , the screws 76 may not be used.

[0104] Fig.17 This modification example is shown, and the screw 75 here is configured to fix the short-circuit component 32 and the first insulator 28 with a predetermined tightening force. If the screw 75 is screwed to the first insulator 28, the size is set so that it can be in close contact with the welding terminal 50 and each sheet metal component 68A to 68C of the short-circuit component 32, the internal thread 54 of the welding terminal 50 and the screw 76 can be omitted.

[0105] On the contrary, if the short-circuit member 32 can be stably supported by the screws 76 , the screws 75 for fixing the short-circuit member 32 can be omitted.

[0106] Fig.18 This modification is shown, where the screw 76 is configured to fix the short-circuit component 32 and the first insulator 28 (actually via the internal thread 54) relative to each other by a prescribed tightening force. When the screw 76 is fixed to the internal thread 54, the short-circuit component 32 and the first insulator 28 are threadedly fixed. In this case, it is necessary to set the size so that the sensor circuit substrate 31 does not shake. Therefore, the screw 75 is omitted here, and the threaded boss 40, the through hole 59 of the protrusion 58 of the sensor circuit substrate 31, and the boss 66 can also be omitted. In this case, it is also possible to provide a concave and convex portion that fits into each other between the short-circuit component 32 and the first insulator 28, or to provide a positioning portion that engages with the other side on either side.

[0107] (Effects of the invention related to the method for manufacturing a stator)

[0108] In the electric drill 1 of the above-mentioned method, a manufacturing method of the stator 25 of the brushless motor 7 (motor for electric working machine) is adopted, which includes the following steps, namely, a first step of winding the winding 30 while the first insulator 28 (insulator) is retained on the stator core 27; a second step of fusing the magnetic wire 30a (winding wire) of the winding 30 to the welding terminal 50 (winding terminal) retained by the first insulator 28; and a third step of making the first sheet metal parts 68A to the third sheet metal parts 68C and the welding terminal 50 conductive by screwing the first sheet metal parts 68A to the third sheet metal parts 68C connected to the power line 72 (lead wire) on the welding terminal 50.

[0109] Therefore, conventional welding is not required, and the assembly man-hours can be reduced. In addition, by adopting screw fastening, the process from the winding of the winding 30 to the completion of the stator 25 is not fixed, so there is a degree of freedom in process design.

[0110] In particular, here, since the welding terminal 50 has the internal thread 54 for screw fixing integrally, a nut is not required, and further cost reduction can be expected.

[0111] In the above embodiment, the sensor circuit substrate and the short-circuit component are arranged on the first insulator side, but they may be arranged on the second insulator side. In addition, the sensor circuit substrate and the short-circuit component are not limited to being arranged on the same insulator side. Figures 19 to 21 As shown in the stator 25A, in the first insulator 28, only the short-circuit component 32 is fixed to the threaded boss 40 by screws 75, and each sheet metal component 68A to 68C is connected to the welding terminal 50 by screws 76. On the other hand, the second insulator 29 is provided with threaded holes 47, 47 ..., and the protrusion 58 of the sensor circuit substrate 31A is fixed to the second insulator 29 by screws 77. Here, the sensor circuit substrate 31A is not covered by the resin part, and the single substrate part 55 is fixed with the rotation detection element 56 facing the outside (rear side). The arrangement of the sensor circuit substrate 31A and the short-circuit component 32 may also be reversed front and back.

[0112] Fig. 22 A rechargeable grinder 120 is shown as an example of an electric working machine using the stator. The grinder 120 has a cylindrical motor housing 121, which accommodates a brushless motor 7A using the stator 25A, with the second insulator 29 located at the front side, and a transmission mechanism case 122 is arranged in front of the motor housing 121 so that a main shaft 123 extends downward. A cylindrical handle housing 124 with a smaller diameter than the motor housing 121 and located at an eccentric position slightly above is arranged behind the motor housing 121, and a battery mounting portion 125 accommodating the controller 111 is arranged behind the handle housing 124, and the entire structure is extended in the front-rear direction.

[0113] The motor housing 121, the handle housing 124 and the battery mounting portion 125 are formed into an integral cylindrical shape and are formed by assembling a pair of left and right split housings by screws. The motor housing 121 and the transmission mechanism case 122 are connected via a disc-shaped transmission mechanism case cover 126 by screws inserted from the front.

[0114] The brushless motor 7A here is housed in the motor housing 121 with the rotating shaft 85 facing forward in the front-rear direction, and the front end of the rotating shaft 85 is pivotally supported by a bearing not shown in the figure and protrudes into the transmission mechanism housing 122, wherein the bearing not shown in the figure is held by the transmission mechanism housing cover 126. Behind the transmission mechanism housing cover 126, a centrifugal fan 89A is installed on the rotating shaft 85, and the centrifugal fan 89A is formed by a resin mixed with a magnetic material and is alternately magnetized to an N pole and an S pole in the direction of rotation. Therefore, the centrifugal fan 89A also has the function of a magnetic sensor, and no permanent magnet is set on the rotor 26 here. However, the centrifugal fan 89A can also be formed without a magnetic material, but the front and back sides of the sensor circuit substrate 31A can be inverted, and the permanent magnet 87 set on the rotor 26 can be detected as before.

[0115] The transmission case cover 126 is provided with a through hole (not shown) to allow air from the centrifugal fan 89A, which is guided forward by a baffle 127 provided at the front of the motor housing 121, to be sent into the transmission case 122. The transmission case 122 is provided with exhaust ports 128, 128, ... formed on the front surface.

[0116] A bevel gear (not shown) is fixed to the front end of the rotating shaft 85 protruding into the transmission mechanism housing 122, and the bevel gear meshes with a bevel gear (not shown) fixed to the upper end of the main shaft 123. The main shaft 123 is pivoted by upper and lower bearings (not shown) and extends downward, and a top tool 130 such as a disc-shaped grinding wheel can be installed at the lower end of the main shaft 123, wherein the upper and lower bearings (not shown) are held by the transmission mechanism housing 122 and a bearing box 129 assembled at the lower part of the transmission mechanism housing 122. A wheel cover 132 is installed on the outer periphery of the bearing box 129, and the wheel cover 132 covers the rear half of the top tool 130 through a belt-shaped clamp 131.

[0117] On the other hand, on the upper side of the handle housing 124, the switch 133 that is turned on by pressing the operation button 134 is held in a posture of the button 134 facing forward by a retaining rib 135 protruding from the inner surface of the handle housing 124. Accordingly, a space for passing the power line 72 and the signal line 60 is formed below the switch 133. In addition, a sliding rod 136 that can slide forward and backward is provided above the switch 133. The rear end of the sliding rod 136 is connected to a pressing rod 137, which is located in front of the button 134 and is forced to a right rotation position where the button 134 is not pressed. A switch button 138 that can slide forward and backward is provided on the upper surface of the motor housing 121, and a locking piece 139 provided on the lower surface of the switch button 138 protrudes into the motor housing 121 and is locked at the front end of the sliding rod 136.

[0118] Therefore, when the switch button 138 is slid forward by a finger, the slide bar 136 slides forward, the pressing rod 137 rotates to the left and presses the button 134, thereby turning on the switch 133. When the finger leaves the switch button 138, the slide bar 136 slides to the retreat position, the pressing rod 137 returns to the right rotation position, and the switch 133 is turned off.

[0119] The controller 111 is supported by ribs 140, 140 provided on the inner surface of the battery mounting portion 125 in an inclined posture with the lower end located at a position further forward than the upper end, so that the display portion 114 is exposed on the front surface of the battery mounting portion 125. Behind the controller 111, the terminal block 110 on which the battery pack 5 is slidably mounted from above is held in a posture orthogonal to the front-rear direction, and a window frame 141 having an air intake port 142 covered by a net is installed between the controller 111 and the terminal block 110.

[0120] In this grinder 120, as in the electric drill 1 of the above-mentioned embodiment, the conduction between the terminals and the assembly of the short-circuit component 32 can be achieved without welding on the stator 25A, thereby improving production efficiency. In addition, even if one of the stator 25A and the controller 111 fails, the two can be easily separated by removing the screws 75 and 76, thereby making it easy to repair one of the two, and thus having excellent maintainability. In addition, it becomes a reasonable structure as follows, that is, the welding terminal 50 can be electrically connected to the first sheet metal component 68A to the third sheet metal component 68C by the screw 76, and the short-circuit component 32 and the first insulator 28 can also be fixed. In addition, since the internal thread 54 is formed on the welding terminal 50, the number of parts can be reduced, thereby suppressing the cost increase.

[0121] In the grinder 120, as long as the short-circuit member 32 can be stably supported by the screws 76 that connect and conduct the welding terminal 50 to the sheet metal members 68A to 68C, the screws 75 for fixing the short-circuit member 32 can be omitted. Conversely, the screws 75 for fixing the short-circuit member 32 can be left and the screws 76 can be omitted.

[0122] In addition, in each invention, the electric working machine is not limited to electric tools for driving top tools such as electric drills, circular saws, and grinders, and each invention can also be applied to gardening tools such as cleaners, lawn mowers, and blowers. In addition, the present invention can also be applied to electric working machines using sensorless brushless motors without sensor circuit boards.

Claims

1. An electric working machine, characterized in that: comprising an electric machine having a stator and a rotor, The stator comprises: stator core; an insulator held on the stator core; a plurality of windings wound around the stator core via the insulator; a plurality of winding terminals which are held by the insulator and are connected to the windings, respectively, and are integrally formed with a cylindrical nut portion having an internal thread formed on the inner circumference; and a short-circuit component having a plurality of lead terminals connectable to the respective winding terminals, The lead terminals are connected to the winding terminals by screws screwed into the nut parts, so that the winding terminals are electrically connected to the lead terminals, and the short-circuit component is detachably fixed to the insulator by the screws.

2. The electric working machine according to claim 1, characterized in that: The nut portion is formed by curling a strip-shaped metal member included in the winding terminal into a C-shape.

3. The electric working machine according to claim 1 or 2, characterized in that: The short-circuit component includes a resin insulating portion for holding the plurality of lead terminals, and the insulating portion is fixed to the insulator by a second screw.

4. The electric working machine according to claim 3, characterized in that: The electric working machine includes a rotor and a sensor circuit substrate, wherein: The rotor is arranged inside the stator core; The sensor circuit board detects the position of a permanent magnet provided on the rotor. The sensor circuit substrate is fixed between the insulator and the short-circuit member by the second screw.

5. An electric working machine, characterized in that: comprising an electric machine having a stator and a rotor, The stator comprises: stator core; an insulator held on the stator core; A winding wound around the stator core via the insulator; a winding terminal which is held by the insulator and connected to the winding and is integrally formed with a cylindrical nut portion having an internal thread formed on the inner circumference; and A lead terminal, which can be connected to the winding terminal, The lead terminal is fixed to the winding terminal by a screw screwed into the nut portion, thereby making the winding terminal and the lead terminal conductive.

6. The electric working machine according to claim 5, characterized in that: The nut portion is formed by curling a strip-shaped metal member included in the winding terminal into a C-shape.

7. A method for manufacturing a stator of a motor for an electric working machine, characterized in that: In a motor for an electric working machine having a stator and a rotor, a method for manufacturing the stator includes a first step, a second step, and a third step, wherein: In the first step, winding is performed while an insulator is held on a stator core of the stator; In the second step, the winding wire of the winding is welded to the winding terminal held by the insulator, wherein the winding terminal is integrally formed with a cylindrical nut portion having an internal thread formed on the inner periphery for screw fixing; In the third step, a lead terminal for connecting a lead wire is screwed onto the nut portion of the winding terminal, thereby establishing electrical conduction between the lead terminal and the winding terminal.

Images