Power tool

Abstract

Electric work machine (1) with: a motor (10) with a stator (12) with a stator core (120), an insulator (122), and a plurality of coils (112), a rotor (14) which is rotatable about a central axis in relation to the stator (12), and a motor shaft (16) which is fixed to the rotor (14); a sensor board (116) with a rotation detection element designed to detect a rotation of the rotor (14) and output a signal; an output part (6) which is driven by the motor shaft (16); and a connection unit (114) which is fixed to the insulator (122) and a plurality of conductive sheet metal components (152a-152c) with a terminal connected to the plurality of coils (112), and a resin component (150) that is integrally formed with the majority of the sheet metal components (152a-152c); in the the sensor board (116) is fixed to the connection unit (114), the connection unit (114) is screwed to the insulator (122) by a plurality of first screws (188), the sensor board (116) is screwed to the connection unit (114) with a plurality of second screws (228), and the majority of the first screws (188) are located radially outwards from the majority of the second screws (228).

Description

[0001] The present invention relates to an electric power tool, such as a hammer drill.

[0002] A type of impact drill having a brushless motor is known as described in JP 2015-56953A.

[0003] The US 2015 / 0069864A1, the DE 102016108841A1, the US 2014 / 0361645A1 and the US 2017 / 0110946A1 disclose further electrical work machines.

[0004] A brushless motor 17, described in JP 2015-56953A, comprises a sensor board (sensor circuit board, sensor plate) 24 and a short-circuiting device 25. The sensor board 24 is equipped with a rotation sensing element. The rotation sensing element detects the position of a permanent magnet 63, which is arranged on a rotor 19, and outputs a rotation sensing signal. The short-circuiting device 25 is ring-shaped and has six short-circuiting tabs 53. The short-circuiting tabs 53 connect six coils 23 in a delta connection. The coils 23 are wound sequentially around a stator core 20, which is made of laminated sheet steel.

[0005] The stator core 20 has six teeth 26 around which the coils 23 are wound. The stator core 20 is inserted between a front insulator 21 and a rear insulator 22. The front insulator 21 has six mounting sections 29 that are integrally formed with it, each of which is mounted between adjacent pairs of teeth 26. Similarly, the rear insulator 22 has six mounting sections 39 that are integrally formed with it. The short-circuiting device 25 is attached to the front of the front insulator 21, while the sensor board 24 is inserted between them. Six fusible links 42 are attached to the front insulator 21, and each is electrically connected to a corresponding pair of windings 23a arranged between the coils 23. Each of the fusible links 42 is soldered to a corresponding short-circuiting tab 53 of the short-circuiting device 25.Two short-circuit tabs 53 are arranged on each of the three sheet metal components 52A to 52C. Power supply lines 57 are welded to the sheet metal components 52A to 52C on a piece-by-piece basis. The power supply lines 57 extend to a mounting section 4 for a battery pack 5.

[0006] In the impact drill described in JP 2015-56953A, the respective fusible links 42 are attached to the front insulator 21. Therefore, the design of the respective fusible links 42 is subject to limitations, and it is difficult to accommodate an increase in the number of coils 23, etc.

[0007] Furthermore, the power supply lines 57 are soldered to the sheet metal components 52A to 52C of the short-circuiting component 25. Therefore, even if either the brushless motor 17 or the mounting section 4 has a problem or requires inspection, it is necessary to cut all power supply lines 57, remove them collectively for repair, replace them, or inspect them. This requires time-consuming effort and incurs costs.

[0008] The subject of the present disclosure is to provide an electric working machine with a motor that is able to easily cope with even a complex coil connection structure.

[0009] One aspect is an electric work machine according to claim 1 or claim 5.

[0010] The electric work machine, which has a motor, according to the present disclosure, is able to easily cope even with a complex coil connection structure. Fig. Figure 1 is a vertical central cross-sectional view of a hammer drill according to one embodiment. Fig. 2 is an enlarged partial view of Fig. 1. Fig. Figure 3 is a perspective view of a stator of a motor in the embodiment. Fig. Figure 4 is a perspective exploded view of Fig. 3. Fig. 5 is a sub-view of Fig. 3. Fig. Figure 6 is a cross-sectional view of Fig. 5 along line AA. Fig. Figure 7 is a cross-sectional view of Fig. 5 along line BB. Fig. Figure 8 is a cross-sectional view of Fig. 5 along line CC. Fig. Figure 9A is a diagram showing a rear view of the area surrounding teeth and an enamel connection slot, and Fig. Figure 9B is a diagram showing a perspective view of the area around the teeth and the enamel connection slot. Fig. Figure 10 is a circuit diagram of coils in a stator in the embodiment. Fig. Figure 11 is a perspective view of a connection unit in the stator in the embodiment. Fig. 12A is a diagram showing a bottom view of Fig. 11 shows, Fig. 12B is a diagram showing a right-hand view of Fig. 11 shown, and Fig. 12C is a diagram showing a rear view of Fig. 11 shows. Fig. 13 is a perspective exploded view of Fig. 11.

[0011] An embodiment and modifications of the present disclosure are explained below based on drawings on a needs-based basis.

[0012] In the embodiment and the variations, the directional terms "front", "back", "top", "bottom", "right" and "left" are defined for explanatory purposes and are changed according to a working condition, a state of a component in motion, etc.

[0013] It should be noted that the present disclosure is not limited to the following embodiment and modifications.

[0014] Fig. Figure 1 is a vertical, central cross-sectional view of an impact drill (hammer drill) 1 as an example of a power tool (impact tool) according to the embodiment, whereas Fig. 2 an enlarged view of a front part in Fig. 1 is.

[0015] The impact drill 1 comprises a housing 2, a power unit 4, an intermediate unit 5, and an output unit 6. The housing 2 is a frame for holding a variety of components. The power unit 4 is located in the center of the housing 2 and generates power (force). The intermediate unit 5 is located above the power unit 4 and converts and transmits the power from the power unit 4. The output unit 6 is located forward of the intermediate unit 5 and outputs the power generated by the power unit 4 and then converted by the intermediate unit 5 on an as-needed basis.

[0016] The output part 6 has a tool holder 8 and a firing pin 9. The tool holder 8 is provided with a tool socket retaining section 7 on its front. The tool socket retaining section 7 has a tubular shape and allows a tool socket to be attached to its front end. The firing pin 9 is located within the tool holder 8 and strikes the tool socket.

[0017] The power section 4 has a motor 10.

[0018] The motor 10 is an internal rotor brushless motor comprising a stator 12 and a rotor 14. The stator 12 has a tubular shape, and its axis extends in the up-and-down direction. The rotor 14 is located inside the stator 12 and is rotatable relative to the stator 12. The rotor 14 has a motor shaft 16, which is also oriented in the up-and-down direction along its axis. The motor shaft 16 has a pinion 18 formed at its upper end.

[0019] The housing 2 has a motor housing 20 for holding the motor 10.

[0020] A handle housing 22, formed by combining right and left components divided into halves, is connected to the rear section of the motor housing 20. The handle housing 22 is in the shape of a loop. A section of the loop, located at the rear with respect to the up-and-down direction, is primarily gripped by a worker. A capacitor 23 and a switch 24 are held by the rear section of the handle housing 22. The switch 24 has a plunger 26. The plunger 26 projects forward and can be pushed backward. The switch 24 is activated by whether the plunger 26 is pressed or not and by the amount of pressure exerted by the plunger 26. The plunger 26 is coupled to a push button 28, which projects forward from the rear section of the handle housing 22.

[0021] A lower housing 30 is arranged on the underside of the motor housing 20 and the handle housing 22. The housing 2 incorporates the lower housing 30.

[0022] Two ribs 31, each U-shaped, are raised inside the lower housing 30 and hold a control unit 32. The control unit 32 is embedded with a microcomputer (not shown in the drawings) for controlling the motor 10, etc., and a switching element (not shown in the drawings).

[0023] A battery mounting section 36 is located below the control unit 32, and in particular on the lower surface of the lower housing 30. The battery mounting section 36 has two terminal blocks 34, arranged one at the rear and one at the front. Battery packs 37 are slid from the right side in the right and left directions and are attached to the terminal blocks 34, respectively.

[0024] A light (a lamp) 38, such as an LED, is arranged forward of the control 32 in the front section of the lower housing 30 for illumination in front of the output part 6.

[0025] Protective plate sections (mudguard sections) 39 are formed on the front and rear sections of the lower housing 30. The protective plate sections 39 project downwards from this housing, covering the attached battery packs 37 from the front and rear.

[0026] The control unit 32 is electrically connected to the motor 10, the capacitor 23, the respective terminal blocks 34 and the light 38 by connecting wires (not shown in the drawings).

[0027] The intermediate part 5 comprises a power transmission mechanism 42, a striking mechanism 44, and an output housing 46. The output housing 46 is formed by combining right and left components, which are divided into halves, as the outer shell of the power transmission mechanism 42 and the striking mechanism 44. The housing 2 comprises the output housing 46.

[0028] The power transmission mechanism 42 transmits a rotary drive force from the motor shaft 16 to the tool holder 8. The power transmission mechanism 42 has an intermediate shaft 50 extending in the up-and-down direction and a gear 52 integrally attached to the central section of the intermediate shaft 50.

[0029] The intermediate shaft 50 is supported by an upper bearing 54 and a lower bearing 56, while it is rotatable about the central axis thereof.

[0030] The gear 52 is toothed with the front section of the pinion 18.

[0031] Conical teeth (helical teeth) 58 are formed on the upper end of the intermediate shaft 50.

[0032] The bevel teeth 58 are toothed with a bevel gear 59, which is connected to the rear end of the tool holder 8.

[0033] The striking mechanism 44 converts a rotary output of the motor shaft 16 into a reverse-and-forward reciprocating output and transmits the reverse-and-forward reciprocating output to the firing pin 9, thereby exerting a blow on the firing pin 9.

[0034] The striking mechanism 44 comprises a crankshaft 60 extending in the up-and-down direction, a gear 62, a connecting rod 64, and a piston 66. The gear 62 is integrally attached to the lower section of the crankshaft 60 and meshes with the rear section of the pinion 18. With the aforementioned configuration, the rotary output of the motor shaft 16 is converted into a forward-and-backward reciprocating output.

[0035] The crankshaft 60 is supported by an upper bearing 68 and a lower bearing 70, while being rotatable about its central axis. The crankshaft 60 is provided with a crankpin 72 at its upper end. The crankpin 72 projects upwards and is eccentric to the central axis of the crankshaft 60. The piston 66 is coupled to the crankpin 72 by the connecting rod 64. The piston 66 has a columnar shape and makes contact with the inner surface of a cylinder 74 at part or all of its outer surface. The cylinder 74 has a cylindrical shape and an axis extending in both the forward and backward directions. The piston 66 moves within the cylinder 74 in the forward and backward directions. The front section of the cylinder 74 is located within the tool holder 8.

[0036] A striking element 82 is arranged forward of the piston 66 through an air chamber 80 within the cylinder 74. With this configuration, the back-and-forth motion is transmitted to the firing pin 9.

[0037] The striking element 82 has a column-like shape and makes contact with the inner surface of the cylinder 74 at part or all of its outer surface. The striking element 82 is moved back and forth within the cylinder 74 in a forward and backward direction.

[0038] The air chamber 80 is a space enclosed by the rear surface of the striking element 82, the front surface of the piston 66, and part of the inner surface of the cylinder 74. The air chamber 80 transmits the reciprocating motion of the piston 66 to the striking element 82 by means of fluctuations in air pressure.

[0039] The front end of cylinder 74 has a front wall which has a hole in the middle of it and extends above, below, right and left.

[0040] A receiving ring 86 is arranged forward of the cylinder 74 by a ring 84, which is made of elastic material, inside the tool holder 8.

[0041] The firing pin 9 is arranged forward of the striking element 82. The firing pin 9 has a rear section, which is columnar in shape, and a front section, which is columnar in shape and has a larger diameter than the rear section. The rear end of the tool holder, which is inserted into the tool holder retaining section 7, presses against the front end of the firing pin 9, thereby retracting the firing pin 9 to make contact with the receiving ring 86 at a boundary section between the front and rear sections. Accordingly, the rear half of the rear section of the firing pin 9 is located within the tool holder 8 and the cylinder 74, while passing through the hole in the front wall of the cylinder 74. Likewise, the front half of the rear section of the firing pin 9 is located within the tool holder 8 and the ring 84.On the other hand, the front section of the firing pin 9 is located inside the tool holder 8.

[0042] The striking element 82 strikes the tool base, which is attached to the tool base retaining section 7, by moving back and forth repeatedly through the striking pin 9 to collide with the rear end of the tool base.

[0043] An actuating sleeve 88, which has a cylindrical shape, is arranged forward of the output housing 46 and outside the tool holder 8 for performing an attachment / release actuation for the tool base.

[0044] The rotor 14 of the motor 10 has a rotor core 90, which is cylindrical in shape, and permanent magnets 92, each of which is plate-shaped. The rotor core 90 is integrally mounted to the central section of the motor shaft 16 such that it is concentric with the motor shaft 16. The permanent magnets 92 are arranged in a plurality of eight through-holes. The through-holes, which extend in both the top and bottom directions, are aligned in the circumferential edge section of the rotor core 90 such that they are concentric with the motor shaft 16.

[0045] The rotor core 90 is a laminate formed by laminating a plurality of electromagnetic steel plates (steel sheets, steel discs). The rotor core 90 has a plurality of (four) recesses (hollow sections) 94 between the permanent magnets 92 and the motor shaft 16. Each recess 94 extends in a quarter-cylindrical shape, with the top-and-bottom direction being its axial direction.

[0046] The permanent magnets 92 are arranged as a whole in the form of a regular octagonal prism and are slightly separated from one another in the circumferential direction. Projecting spaces (not shown in the drawings) are formed at both ends of each through-hole. Each projecting space is formed over one end of each permanent magnet 92 such that it projects circumferentially outwards to an intermediate position between each permanent magnet 92 and its circumferentially adjacent permanent magnet 92. The projecting spaces continue into the main space of each through-hole penetrated by the respective permanent magnet 92 and are part of each through-hole.

[0047] An upper sleeve 96 is arranged on the top side of the rotor core 90. The upper sleeve 96 is in the form of a disk having the same radius as the rotor core 90. A lower sleeve 98 is arranged on the underside of the rotor core 90 such that its outer circumference lies radially inside the permanent magnets 92.

[0048] A resin 100 is arranged such that it extends to areas above and below the upper sleeve 96, an area below the lower sleeve 98, and an area connecting these areas, i.e., an area on the outer circumferential side of the motor shaft 16. The rotor 14 is integrated by the resin 100. The resin 100 is arranged between the upper sleeve 96 and the motor shaft 16, between the rotor core 90 and the motor shaft 16, and between the lower sleeve 98 and the motor shaft 16.

[0049] The motor shaft 16 is supported by an upper bearing 102 and a lower bearing 104, while it is rotatable about the central axis thereof.

[0050] The upper bearing 102 is located on the underside of the pinion 18 and is held by the output housing 46.

[0051] The lower bearing 104 is held by the motor housing 20, while it is positioned above the lower end of the motor shaft 16 and on the underside of the lower sleeve 98.

[0052] A centrifugal blower 106, which has a disc shape, is integrally attached to the upper section of the motor shaft 16 such that it is perpendicular to the motor shaft 16, while it is positioned between the upper bearing 102 and the upper sleeve 96.

[0053] A deflector plate 108, which has a saucer shape, is arranged between the centrifugal blower 106 and the upper sleeve 96 such that it covers the underside of the centrifugal blower 106. The deflector plate 108 is held by the motor housing 20.

[0054] As in Fig. As shown in Figures 3 to 8, the stator 12 of the motor 10 has a stator core arrangement 110, a plurality of (twelve) coils 112, a connection unit 114, a sensor board 116 and a circuit board pressing component (circuit board pressing component) 118.

[0055] The stator core assembly 110 comprises a stator core 120 and an insulator 122. The insulator 122 is held by the stator core 120, while it is arranged above, below, and inside the stator core 120.

[0056] The stator core 120 is a laminate obtained by laminating a plurality of electromagnetic steel plates (steel sheets, steel discs), each of which has a ring shape. The stator core 120 has a plurality of (twelve) teeth 130 on its inner circumferential section. The teeth 130 project radially inwards and are aligned at equal intervals in the circumferential direction.

[0057] The radially inner tip surface of each tooth 130 has an inwardly bulging shape. More precisely, each tooth 130 has both lateral bulging sections 130a and a central recessed (hollowed) section 130b. The two lateral bulging sections 130a bulge gradually inward from the two circumferential ends of the tip surface to positions near the central section of the tip surface. The central recessed section 130b is shallowly radially outward on the central section of the tooth tip such that it does not radially reach an imaginary arc connecting the two ends of the tooth tip. With the tip surface shape of each tooth 130 described above, a transition in the magnetic pole in a magnetic field excited by the coils 112, in conjunction with a switching of the switching element, is smoothly controlled, and the rotation of the rotor 14 is stabilized as much as possible.

[0058] Spaces created between adjacent teeth 130 function as slots in which the coils 112 are arranged.

[0059] A plurality of (three) outer grooves 131, each extending in the top and bottom directions, are formed on the cylindrical surface of the outer circumferential section of the stator core 120. The outer grooves 131 are arranged at equal intervals in the circumferential direction.

[0060] The insulator 122 is a ring-shaped, electrically insulating component made of resin and has toothed coating sections (tooth covering sections) 132 and a cylindrical section 133. The toothed coating sections 132 are arranged outside the teeth 130, respectively. The cylindrical section 133 bulges downwards in a ring shape while connecting the toothed coating sections 132.

[0061] As in Fig. As shown in Figure 9, each tooth coating section 132 coats a corresponding tooth 130, excluding its tip. Each tooth coating section 132 has a wall section 134 adjacent to the tip of the corresponding tooth 130. The wall section 134 extends to the top, bottom, and both circumferential sides of the tip of the corresponding tooth 130. Furthermore, each tooth coating section 132 has grooves 135 formed circumferentially on the top and bottom surfaces of a region that coats the root of the corresponding tooth 130. Each groove 135 has a width corresponding to the thickness of one of the windings of each coil 112.

[0062] A connecting part guard 136 is formed outside the cylindrical section 133, projecting radially outward from the rear section of the insulator 122. The central section of the connecting part guard 136 is positioned between two teeth 130 located on the rear side. The right and left ends of the connecting part guard 136 are located within the right and left ends of the two teeth 130 located on the rear side.

[0063] A plurality of (five) screw projection sections (screw boss sections) 138, each having a screw hole extending in the top-and-bottom direction, are formed on the lower section of the cylindrical section 133. The five screw projection sections 138 and the connecting part guard 136 are arranged at equal intervals in the circumferential direction, and fusible connection slots 140 are arranged, respectively, between adjacent pairs of screw projection sections 138 and the connecting part guard 136. Thus, the fusible connection slots 140 are spaced at equal intervals in the circumferential direction. Each tooth 130 is located between and within each (a respective) fusible connection slot 140 and either the connecting part guard 136 or each (a respective) screw projection section 138.

[0064] As in Fig. As shown in Figure 9, each melt connection slot 140 has a pair of first and second projections 142 and 144, each having a U-shaped cross-section. The first and second projections 142 and 144 are oriented circumferentially.

[0065] Viewed from below, the second projection 144 is arranged downstream of the first projection 142 in a clockwise direction.

[0066] Each of the first and second projections 142 and 144 projects radially outward from the cylindrical section 133 and also projects downward at two positions, located radially inside and outside. The inner projection extends downward to a greater height than the outer projection, and a region between the inner and outer projections continues to the lower surface of the cylindrical section 133. Furthermore, a region between the first projection 142 and the second projection 144 is indented further upward than the lower surface of the cylindrical section 133. Additionally, the inner projection of the second projection 144 has an extension section 145 that extends circumferentially.The extension section 145 has a projecting end 146, located on the clockwise side when viewed from below, as an end face extending in the top-and-bottom direction. The projecting end 146 continues to each melt connection slot 140 as part of each melt connection slot 140.

[0067] The inwardly projecting section of the second projection 144, which has the extension section 145 and the projection end 146, projects downwards with its greatest height below the sections projecting downwards from the cylindrical section 133. The tip of the inwardly projecting section is the lowest section of the insulator 122.

[0068] A recess 147 is formed outside each projection end 146. The recess 147 has a size approximately equal to the cross-sectional diameter of one of the windings of each coil 112. The root section (top section) of each projection end 146 is common to the counterclockwise inner side of the recess 147. The top-down orientation of the bottom section (top section) of the recess 147 and that of the area between the first projection 142 and the second projection 144 are approximately the same.

[0069] The projection end 146 is located on the clockwise side of a surface F of the tooth coating section 132 that corresponds to (is closest to) the corresponding surface F in the circumferential direction. Viewed from below, surface F is the counterclockwise surface of the tooth coating section 132.

[0070] A concave depression 148, concave upwards, is formed on the root of the inwardly projecting section of the first projection 142. The concave depression 148 prevents the root of the inwardly projecting section of the first projection 142 from bulging during forming. It should be noted that the design of the recess 147 similarly prevents the root of the projection end 146 from bulging during forming.

[0071] The stator core arrangement 110 is formed by integrally forming the stator core 120 and the insulator 122.

[0072] The integral forming process used herein is not particularly limited to any one specific method. For example, a mold-injection injection molding process can be used, in which the stator core 120 is inserted into a mold and then resin is injected into the mold, so that the insulator 122 is formed integrally with the stator core 120.

[0073] The insulator 122 is arranged burr-free in a continuous design from the top of the stator core 120 to the bottom of the stator core 120 (the bulging lower sections of the cylindrical section 133 with the connecting part protection 136, the screw projection sections 138 and the fusible connection slots 140) through the inside of the stator core 120 with the exception of the tip surfaces of the teeth 130 (the tooth coating sections 132 and the cylindrical section 133).

[0074] Each coil 112 is formed by winding a wire around each tooth coating section 132.

[0075] As in Fig. As shown in Figure 10, the twelve coils 112 are grouped into a total of three units, each containing four coils 112, and are connected in a (three-phase) delta connection. In each unit, two pairs of coils 112, each pair of which is connected in series, are connected in parallel (in a 2s2p (2-series-2-parallel) configuration).

[0076] The twelve coils 112 are formed by two conductor wires.

[0077] A first conductor wire is stretched from a winding start ST1 over the first and second projections 142 and 144 in an initial fusible link slot 140 and is then wound around two tooth coating sections 132. Subsequently, the first conductor wire is stretched to the next fusible link slot 140 and then wound around two tooth coating sections 132. Furthermore, the first conductor wire is stretched to the next fusible link slot 140 and then back to the initial fusible link slot 140, reaching a winding destination GL1.

[0078] On the other hand, a second conductor wire is wound from a winding start ST2 to a winding end GL2 in a manner similar to the first conductor wire. It should be noted that the second conductor wire passes through the fusible link slots 140 and the tooth coating sections 132, neither of which the first conductor wire passes through.

[0079] As especially in Fig. As shown in Figure 9, a conductor wire section extends from a bridge conductor section 149a, stretched over the fusible link slot 140, from the first projection 142 to the second projection 144 and enters the recess 147. The conductor wire section is then hooked onto the projection end 146 and bent in a reversing shape as a turning section 149b. Furthermore, the conductor wire section is inserted as an oblique insertion section 149c to the surface F (the counterclockwise surface viewed from below) of the corresponding tooth coating section 132 at an oblique angle to the top-down direction. The inclined insertion section 149c continues to form a bottom-to-top section 149d of the first of the windings around the corresponding tooth coating section 132, while the upper end of it is hooked onto the end of the lower grooves 135 on the corresponding tooth coating section 132.In the first winding around the corresponding tooth coating section 132, the upper and lower sections, both of which are extended in the circumferential direction, are guided through the grooves 135, respectively. Each of the second and subsequent windings of the conductor wire is wound in the same manner as the first winding or the preceding winding. The conductor wire, wound with predetermined turns as described above, is arranged between the cylindrical section 133 and the wall section 134 and is obtained as the coil 112.

[0080] The projecting end 146 extends downwards at a considerable height. Therefore, when forming the turning section 149b, it is easy to hook the conductor wire onto the projecting end 146, but it is difficult to unhook the conductor wire, thus preventing the turning section 149b from separating and detaching from the projecting end 146. Furthermore, the recess 147 is provided, which increases the height of the projecting end 146 by a certain amount. The conductor wire also enters the recess 147. Therefore, when forming the turning section 149b, it is easy to hook the conductor wire onto the projecting end 146, but it is difficult to unhook the conductor wire, thus preventing the turning section 149b from detaching.

[0081] It should be noted that Fig. 9 omits a representation of a preceding conductor wire section continuing to the bridge section 149a and of a subsequent conductor wire section continuing from the bridge section 149a, whereas the drawings, with the exception of Fig. 9 Omit a representation of the conductor wire sections from the bridge conductor section 149a to the inclined insertion section 149c (with the exception of conductor wire sections around the coil 112). The conductor wire sections from the bridge conductor section 149a to the inclined insertion section 149c function as coil connecting conductor wires that electrically connect two coils 112.

[0082] The connection unit 114, which is in Fig. Figures 11 to 13 show a terminal unit body 150, a first sheet metal component 152a, a second sheet metal component 152b, and a third sheet metal component 152c. The terminal unit body 150 is made of insulating resin and is in the form of a ring with an internal hole. The first to third sheet metal components 152a, 152b, and 152c are made of conductive metal.

[0083] The connection unit body 150 has a connection part base 160 that projects radially outward from its rear section. The connection part base 160 has three cup sections 164. The cup sections 164 are oriented to the right and left, with two partitions 162, extending upward and downward respectively, inserted between them. Screw projections (screw bosses, screw bosses) 166, each cylindrical in shape, are inserted into the cup sections 164.

[0084] A plurality of (five) screw hole sections 168, each having a screw hole extending in the top and bottom direction, are formed on the circumferential edge of the connection unit body 150. The screw hole sections 168 project radially outwards from it and are arranged in a manner similar to the screw projection sections 138.

[0085] Pin sections 170 are formed in positions adjacent to the front, rear right, and rear left screw hole sections 168. The pin sections 170 project radially outwards from these screw holes and extend upwards. Viewed from below, the pin sections 170 are located at the vertices of an imaginary regular / equilateral triangle, respectively, while they are arranged correspondingly to the outer slots 131 of the stator core 120.

[0086] Screw projection sections (screw boss sections, screw hump sections) 172, each having a screw hole that opens downwards, are formed on the connection unit body 150. The screw projection sections 172 are arranged radially inside the front, rear right, and rear left screw hole sections 168. The screw projection sections 172 project radially inwards with respect to the connection unit body 150.

[0087] Projecting sections 174, each having a downward-projecting projection, are formed on the connection unit body 150. The projecting sections 174 are arranged radially inside the front right and front left screw hole sections 168. The projecting sections 174 project radially inward with respect to the connection unit body 150.

[0088] A rib 176 is formed on the inner surface of the connection unit body 150. The rib 176 is arranged between the front and the front right screw hole section 168 and projects radially inwards from it.

[0089] A recessed section (relief section) 178 is formed on the inner surface of the connection unit body 150. The recessed section 178 is located adjacent to the front right screw hole section 168 and extends radially outwards from it.

[0090] Projections 179 are formed on the front right, front left, rear right and rear left sections of the connecting unit body 150, respectively. Each projection 179 extends radially outwards in a U-shape.

[0091] The first sheet metal component 152a has a semicircular arc shape when viewed from below, in other words a C shape.

[0092] Fuse terminals 180 are arranged on the front end and rear edge of the first metal sheet component 152, respectively, and project upwards from it. Each fuse terminal 180 has a folded section and a pointed section extending from the folded section. In an initial state (before melting), the pointed section is open upwards with respect to the folded section. It should be noted that in Fig. 3 to 8 and 11 to 13 the melt connections 180 are in the initial state.

[0093] A connecting tab 182 is formed on the rear end of the first sheet metal component 152a. The connecting tab 182 projects forward from the rear and has a connecting hole.

[0094] A projecting tab 184 and a bypass section (diversion section) 186 are formed on the front right section of the first metal sheet component 152a. The projecting tab 184 extends radially outwards, whereas the bypass section 186 is diverted radially outwards in a projecting form.

[0095] The second metal sheet component 152b has a U-shape when viewed from below. Similar to the first metal sheet component 152a, the second metal sheet component 152b has melt connections 180 formed on its right and left ends, a connecting tab 182 formed on its rear section, and projecting tabs 184 formed on its rear right and rear left sections.

[0096] The third sheet metal component 152c has an inverted C-shape when viewed from below. Likewise, the third sheet metal component 152c has fusion connections 180 formed on its front end and rear edge, a connecting tab 182 formed on its rear section, and projecting tabs 184 formed on its front left and rear left sections.

[0097] The front-side melting point 180 of the third metal sheet component 152c is located to the right of the front-side melting point 180 of the first metal sheet component 152a. Viewed from below, the first and third metal sheet components 152a and 152c partially overlap, although in a non-contact state.

[0098] Similarly, the right section of the second metal sheet component 152b and the lower section of the first metal sheet component 152a also overlap. Likewise, the left section of the second metal sheet component 152b and the lower section of the third metal sheet component 152c also overlap.

[0099] Similar to the stator core arrangement 110, the connection unit 114 is formed by integrally joining the connection unit body 150 and the first to third sheet metal components 152a, 152b and 152c.

[0100] The first to third sheet metal components 152a, 152b and 152c are aligned in the top-and-bottom direction, which is the thickness direction thereof, without making contact with each other, while they are arranged in a concentric circular arc arrangement.

[0101] The projections 179 and the corresponding projection tabs 184 are integrally assembled and mounted together, thereby positioning the connection unit body 150 and the first to third sheet metal components 152a, 152b, and 152c. Each projection tab 184 is partially exposed, without being covered by the corresponding projection 179. It should be noted that the left-hand projection tab 184 of the second sheet metal component 152b is mounted to the pin section 170 without being exposed.

[0102] The recess section 178 and the bypass section 186 are mounted together.

[0103] The fusible links 180 and the connecting tabs 182 of the first to third sheet metal components 152a, 152b and 152c project from the connection unit body 150. The connecting tabs 182 are separated by the partitions 162 and cover the corresponding screw projections 166. The connection part base 160, the screw projections 166 and the connecting tabs 182 form a stator-side connection part 187.

[0104] The screw hole sections 168 are mounted (placed) onto the corresponding screw projection sections 138, and then screws 188 are inserted into pairs of screw hole section 168 and screw projection 138, respectively. Accordingly, the connection unit 114 is attached to the underside of the insulator 122.

[0105] At this time, tips 170a of the pin sections 170 of the terminal unit 114 are inserted into the outer slots 131 corresponding to them on the stator core 120, thereby reliably positioning the terminal unit 114 with respect to the stator core arrangement 110.

[0106] Each fusible link 180 is inserted in the initial state between the first projection 142 and the corresponding second projection 144 of the fusible link slot 140, thus enclosing the bridge conductor section 149a, which connects the coils 112, with each fusible link 180. Each fusible link 180 is then closed, clamping the bridge conductor section 149a. When heated in this state by electrification or the like, each fusible link 180 and the bridge conductor section 149a are welded together by thermal forming / die forging (melting, fusing). Consequently, an electrical circuit of the coils 112 is formed, with the exception of the power supply lines 198 (which are to be described) and the control unit 32 or the battery packs 37.

[0107] The inwardly projecting section (the lowest section of the insulator 122) of the second projection 144 does not protrude beyond the lower surface of the terminal unit 114 to which the insulator 122 is attached.

[0108] The stator-side connection section 187 is arranged under the connection part protection 136 of the insulator 122.

[0109] A power supply line connecting part 190 is detachably connected to the stator side connecting part 187.

[0110] The power supply-side connection part 190 comprises a connection part base 192, a jaw section 194, three terminal plates 196, and the ends of three power supply lines 198. The connection part base 192 extends upwards, downwards, to the right, and to the left. The jaw section 194 projects from the front section of the connection part base 192 in a Γ-shape when viewed from the side. The terminal plates 196 are raised from the lower section of the jaw section 194 parallel to the upper surface of the jaw section 194, with each terminal plate exposed at its apex, which has a hole. The power supply lines 198 are connected to the corresponding terminal plates 196.

[0111] The power supply lines 198, corresponding to the terminal plates 196 respectively, are inserted between the front section of the connection part base 192 and the rear section of the jaw section 194. A section of each power supply line 198, projecting upwards from the intermediate position, is formed as a core-wire exposed section by removing its sheathing. The core-wire exposed section and the end of the terminal plate 196 corresponding to each power supply line 198 are bonded together, thus connecting each power supply line 198 and its corresponding terminal plate 196 behind the connection part guard 136. The power supply lines 198 extend downwards to the control unit 32. In other words, the power supply lines 198 extend downwards adjacent to the connection unit 114.

[0112] The terminal plates 196 make contact with the corresponding connecting tabs 182, and screws 200 are inserted, respectively, into pairs of the holes in the terminal plate 196 and the connecting holes in the connecting tab 182. Accordingly, the power supply-side connecting part 190 is connected to the stator-side connecting part 187. The screws 200 are also inserted into the corresponding screw projections 166. The partitions 162 are inserted between the terminal plates 196, which are oriented to the right and left. The jaw section 194 and the terminal plates 196 cover the top and back sides of the cup sections 164 of the connecting part base 160 and the underside of the connecting tabs 182.

[0113] With this connection, the circuit of the coils 112 is formed, which includes the power supply lines 198, the control 32, etc.

[0114] By removing the screws 200, the power supply line-side connecting part 190 and the power supply lines 198 can be detached from the stator-side connecting part 187 of the connection unit 114 in a reconnectable manner.

[0115] The sensor board 116 has a ring or donut shape and an outer diameter that allows it to be arranged radially within the inner hole of the connection unit body 150.

[0116] A plurality of (three) rotation detection elements (not shown in the drawings) is mounted on the sensor board 116 so that they detect the position of the permanent magnet 92 of the rotor 14 and output a rotation detection signal.

[0117] The sensor board 116 has three notches 210, which are formed radially inwards on its outer circumferential section, and a rib receptacle 212. The notches 210 are arranged correspondingly to the screw projection sections 172. The rib receptacle 212 is arranged correspondingly to the rib 176.

[0118] The sensor board 116 has pin holes 214 formed on the right and left sides of its front section. The pin holes 214 are arranged correspondingly to the projections of the projection sections 174.

[0119] The back side of sensor board 116 is formed in the shape of a straight line extending in both the left and right directions. A number of signal lines (not shown in the drawings) are connected to the inside of the back side of sensor board 116 by a connector (not shown in the drawings), allowing them to transmit the rotation detection signal output by one of the rotation detection elements. Disconnecting the connector disconnects the signal lines from sensor board 116 in a reconnectable manner.

[0120] Each screw projection section 172 is inserted into the corresponding notch 210 on a tubular part surrounding the screw hole, while the rib 176 is inserted into the rib receptacle 212. Accordingly, the sensor board 116 is positioned radially within the inner hole of the connection unit 114.

[0121] Each projection section 174 is inserted into the corresponding pin hole 214 at its projection. Accordingly, the sensor board 116 is positioned in relation to the connection unit 114.

[0122] The screw projection sections 172, the rib 176 and the projection sections 174 function respectively as guide sections for aligning the sensor board 116 to its mounting position.

[0123] The PCB press component 118 is a ring-shaped insulating component made of resin.

[0124] The circuit board pressing component 118 has screw hole sections 220, a rib recess 222, pin holes 224, and a bridge section 226. The screw hole sections 220, each containing a screw hole, are arranged similarly to the notches 210. The rib recess 222 is designed similarly to the rib recess 212. The pin holes 224 are arranged similarly to the pin holes 214. The bridge section 226 is formed on the rear section of the circuit board pressing component 118, so that it is raised downwards and forwards.

[0125] The outer circumferential section of the circuit board pressing component 118, the outer circumferential sections of the screw hole sections 220, and both the right and left sides of the bridge section 226 project downwards in a cylindrical or plate-like form relative to the circuit board pressing component 118. Accordingly, the circuit board pressing component 118, the screw hole sections 220, and the bridge section 226 are reinforced or shaped.

[0126] The rib 176 is inserted into the rib receptacle 222, and the projecting sections 174 are inserted into the corresponding pin holes 224 at the projections thereof. Accordingly, the circuit board pressing component 118 is positioned on the underside of the sensor board 116, while it is positioned radially within the connection unit 114.

[0127] In this state, screws 228 are inserted into the screw holes of screw hole sections 220 and those of screw projection sections 172, respectively, so that they attach the circuit board press component 118 to the terminal unit 114. Accordingly, the sensor board 116 is attached to the terminal unit 114 in such a way that it is immovable relative to it while it is inserted and pressed between the circuit board press component 118 and the terminal unit 114. If the circuit board press component 118 is removed by loosening the screws 228, the sensor board 116 can be detached in a reinstallable manner, even if it is difficult to separate the stator core assembly 110 and the terminal unit 114 from each other after the fusible links 180 have melted.The sensor board 116 and the circuit board pressing component 118 can be easily attached / detached by means of actuating sections that are not in contact with the connection unit 114, on the recess section 178 of the connection unit body 150.

[0128] The bridge section 226 is located away from the lower surface of the sensor board 116 and the inner circumferential surface of the terminal unit body 150. The signal lines, which are detachably connected to the sensor board 116, are directed towards the controller 32 as they are routed downwards through the bridge section 226. In other words, the signal lines adjacent to the sensor board 116 extend downwards.

[0129] Next, an exemplary movement of the impact drill 1 according to the embodiment will be explained.

[0130] When a worker presses the push button 28 into the handle housing 22, the plunger 26 is pushed down and the switch 24 is turned on, thereby transmitting an on signal to the control unit 32.

[0131] When it receives the ON signal, the controller 32 instructs the microcomputer to receive a rotation detection signal from the sensor board 116 via a relevant signal line, thus determining the rotation state of the rotor 14. The controller 32 also controls the on / off switching of the switching elements according to the received rotation state and sequentially applies excitation current to the coils 112 of phases U, V, and W in the stator 12, causing the rotor 14 to rotate. The switch 24 transmits a signal to the controller 32 corresponding to the pressure of the plunger 26. The controller 32 then controls the rotor 14 to rotate at a speed corresponding to the pressure (e.g., a higher speed corresponds to a higher pressure).

[0132] The motor shaft 16 rotates in conjunction with the rotation of the rotor 14, and this rotation is reduced and transmitted to the intermediate shaft 50 via the gear 52. The bevel teeth 58 of the intermediate shaft 50 are reduced in rotation by the bevel gear 59 and rotate the tool holder 8 about the central axis, which extends in the forward and reverse directions, thereby exerting a rotational force on the tool base attached to the tool base holding section 7. With the power transmission mechanism 44, etc., which generates the aforementioned rotational force, the impact drill 1 performs a drilling motion, processing a workpiece with this rotational force.

[0133] On the other hand, the rotation of the motor shaft 16 is reduced and transmitted to the crankshaft 60 by the gear 62.

[0134] The crankpin 72 moves the piston 66 back and forth within the cylinder 74 via the connecting rod 64. Accordingly, the air within the air chamber 80 acts as an elastic element, causing the striking element 82 to move back and forth. Due to this reciprocating motion, the striking element 82 successively collides with the striking pin 9. The impact of this collision is transmitted to the tool base, which is attached to the tool base retaining section 7, generating a striking force in the back-and-forth direction. With the striking mechanism 44, etc., generating this striking force, the impact drill 1 performs a hammering motion on the workpiece.

[0135] The centrifugal fan 106 rotates in conjunction with the rotation of the motor shaft 16, drawing air into the housing 2 through an intake opening (not shown in the drawings). The air passes through the outside of the stator 12 and the inside of the stator 12 (the space between the stator 12 and the rotor 14) and is then discharged through an outlet opening (not shown in the drawings) formed in the motor housing 20 at a position to the side of the centrifugal fan 106, thereby cooling the brushless motor 10.

[0136] As it passes through the inside of the stator 12, the air passes through the inside of the stator core assembly 110, the connection unit 114, the sensor board 116 and the circuit board pressing component 118, thereby effectively cooling the coils 112 by the air passing through the slots and the surrounding area.

[0137] Next, the advantageous effects of the impact drill 1 according to the embodiment will be explained.

[0138] The impact drill 1 comprises multiple coils 112, the stator 12 which holds the multiple coils 112, the rotor 14 which is rotatable relative to the stator 12, and the connection unit 114 which has multiple fusible links 180 that are electrically connected to the multiple coils 112. Therefore, the design of the fusible links 180 is more flexible than if the insulator 122 were equipped with the fusible links 180. Consequently, the impact drill 1 can easily accommodate an increase in the number of coils 112 and a relatively complex circuit configuration, such as a 2s2p (2-series-2-parallel) delta connection, etc.

[0139] Furthermore, the impact drill 1 features power supply lines 198, which are connected to the connection unit 114. Therefore, connecting the power supply lines 198 is made easy, resulting in good assembly characteristics for the impact drill 1.

[0140] In another aspect, the impact drill 1 comprises multiple coils 112, the insulator 122 which holds the multiple coils 112, the stator core 120 which holds the insulator 122, the rotor 14 which is rotatable relative to the stator core 120, and the connection unit 114, which is electrically connected to the multiple coils 112 and engages with the stator core 120. This allows for a high degree of flexibility in the electrical connection of the coils 112, enabling the impact drill 1 to easily accommodate an increase in the number of coils 112, etc. Furthermore, the connection unit 114 engages with the robust stator core 120, thereby improving the positional accuracy of the connection unit 114 relative to the stator core 120. Furthermore, when the sensor board 116 is mounted on the connection unit 114, the positional accuracy of the sensor board 116 (the rotation detection elements) in relation to the rotor 14 (the permanent magnet 92) is improved.

[0141] Furthermore, the connection unit 114 is attached to the insulator 122 by the screws 188. Therefore, attaching the connection unit 114 is made easy.

[0142] In yet another aspect, the impact drill 1 comprises the multiple coils 112, the insulator 120 which holds the multiple coils 112, the stator core 120 which holds the insulator 122, the rotor 14 which is rotatable relative to the stator core 120, the connection unit 114 which is electrically connected to the multiple coils 112, and the power supply lines 198 which supply electrical power to the multiple coils 112 and are detachably connected to the connection unit 114. Therefore, the electrical connection structure of the coils 112 is highly flexible, allowing the impact drill 1 to easily accommodate an increase in the number of coils 112, etc. Furthermore, if one of the motor 10 and the control unit 32 has a problem or requires inspection, the relevant one can be removed separately by disconnecting the power supply lines 198 from the connection unit 114.This reduces the time-consuming effort and costs required for repair, replacement, or inspection.

[0143] Furthermore, the power supply lines 198 are attached to the connection unit 114 by the screws 200. Therefore, the power supply lines 198 can be easily connected in a detachable manner.

[0144] Furthermore, the impact drill 1 has three power supply lines 198. The power supply lines 198 each have connection plates 196 and are connected to the connection unit 114 by these connection plates 196. The connection unit 114 has the stator-side connection part 187, to which the power supply lines 198 are connected. The stator-side connection part 187 has two partitions 162 that separate the connection plates 196. Therefore, the power supply lines 198 are easily, securely, and detachably connected to the stator-side connection part 187.

[0145] Furthermore, the terminal unit 114 has pin sections 170 that project towards the stator core 120. The stator core 120 has outer slots 131 as engagement sections with which the pin sections 170 engage. The pin sections 170 engage with the outer slots 131 of the stator core 120. Therefore, the terminal unit 114 engages with the resin insulator 122 and the metal stator core 120, thus preventing any minute movement or change in the position of the terminal unit 114 caused by sagging, bending, or warping of the insulator 122. Consequently, the positional accuracy of the connection unit 114 with respect to the stator core 120 is improved, and that of the sensor board 116 (the rotation detection elements) with respect to the rotor 14 (the permanent magnet 92) is improved.

[0146] Furthermore, the impact drill 1 includes the sensor board 116 and the signal lines. The sensor board 116 has the rotation detection elements, each of which outputs a rotation detection signal when it detects rotation of the rotor 14. The sensor board 116 is attached to at least one of the terminal unit 114 and the insulator 122. The signal lines are connected to the sensor board 116, and each transmits the rotation detection signal. The signal lines adjacent to the sensor board 116 extend in the same direction (downwards) as the power supply lines 198 adjacent to the terminal unit 114. Therefore, wiring the signal lines and the power supply lines 198 can be easily accomplished.

[0147] In yet another aspect, the impact drill 1 comprises the multiple coils 112, the insulator 122 which holds the multiple coils 112, the connection unit 114 which is electrically connected to the multiple coils 112 and attached to the insulator 122, the rotor 14 which is rotatable relative to the insulator 122, and the sensor board 116 which detects a rotation of the rotor 14 and is attached to the connection unit 114. The sensor board 116 is detachable from the connection unit 114, while the connection unit 114 is attached to the insulator 122. Therefore, the sensor board 116 can be detached without detaching the connection unit 114. As a result, repair, replacement or inspection of the sensor board 116 is made easy, and a reduction in time-consuming effort and costs required in the event of a problem, inspection, etc. related to the motor 10 is achieved.

[0148] In yet another aspect, the impact drill 1 comprises the multiple coils 112, the insulator 122 which holds the multiple coils 112, the connection unit 114 which is electrically connected to the multiple coils 112 and attached to the insulator 122, the rotor 14 which is rotatable relative to the insulator 122, and the sensor board 116 which detects a rotation of the rotor 14. The sensor board 116 is attached to at least one of the insulator 122 and the connection unit 114, which is integrally attached to the insulator 122. In other words, the sensor board 116 is attached after the connection unit 114 has been attached. Therefore, the sensor board 116 can be detached without detaching the connection unit 114. As a result, repair, replacement or inspection of the sensor board 116 is made easy, and a reduction in time-consuming effort and costs associated with a problem, inspection, etc.The work required in connection with engine 10 will be carried out.

[0149] Furthermore, the impact drill 1 features the circuit board pressing component 118, which is made of resin, for attaching the sensor circuit board 116. Therefore, the sensor circuit board 116 can be reliably attached without being affected by electrical actuation. In addition, the sensor circuit board 116 can be removed by removing the screws 228 and the circuit board pressing component 118.

[0150] Furthermore, the connection unit 114 has guide sections (the screw projection sections 172, the rib 176, and the projection sections 174) that align / guide the sensor board 116 to its mounting position. Therefore, the sensor board 116 is reliably mounted in the desired position, and the positional accuracy of the rotation detection elements with respect to the permanent magnet 92 is improved. As a result, the rotation of the rotor 14 is accurately detected and controlled as reliably as possible, thereby stabilizing the rotation of the rotor 14 to the greatest extent possible.

[0151] Furthermore, the connection unit 114 is designed in the form of a ring with an inner hole. The sensor board 116 is arranged within the inner hole of the connection unit 114. Therefore, the connection unit 114 and the sensor board 116 overlap in the axial direction of the motor shaft 16, thereby shortening the motor 10 and making it as compact as possible.

[0152] In yet another aspect, the impact drill 1 comprises multiple coils 112, the stator core 120, the insulator 122 (which is integrally formed with the stator core 120 and holds the multiple coils 112), and the rotor 14 (which is rotatable relative to the stator core 120). Therefore, unlike an impact drill that has a front insulator and a rear insulator provided separately from the front insulator, the impact drill 1 does not require an overlap section to reliably establish an insulation gap. This allows for a high output with large coils 112 or enables the impact drill 1 to be made compact while maintaining the required output. Furthermore, the stator core assembly 110 is obtained by integrally forming the stator core 120 to the insulator 122. Thus, the motor 10 exhibits good assembly characteristics.Furthermore, the robustness of the insulator 122 is improved by integral forming. When the insulator 122 is provided with the screw projection sections (mounting sections) 172 and the fusible connection slots (receiving sections) 140 of the connection unit 114, the strength of the mounting sections and the receiving sections is improved.

[0153] Furthermore, the stator core 120 has the multiple teeth 130 that hold the coils 112, and the insulator 122 has the tooth coating sections 132, each of which coats (covers) one of the multiple teeth 130 except for the tip section. Therefore, the teeth 130 that hold the coils 112 are coated with the integrally formed tooth coating sections 132, making the impact drill 1 compact while reliably producing the required output, and exhibiting good assembly behavior and robustness.

[0154] Furthermore, the insulator 122 is arranged in a continuous configuration. Therefore, the insulator 122 is compact in relation to the stator core 120. In addition, the insulator 122 extends continuously to the inside, the top, and the bottom of the stator core 120, thereby robustly attaching the insulator 122 to the stator core 120, and the attachment and receiving sections of the insulator 122 are also robust.

[0155] In yet another aspect, the impact drill 1 has the stator core 120, which has the several teeth 130 that are aligned in the circumferential direction, the rotor 14, which is rotatable with respect to the stator core 120, the insulator 122, which is held by the stator core 120 and has the several tooth coating sections 132 that cover the several teeth 130, and the projecting end 146, which corresponds to one of the several tooth coating sections 132, the several coils 112 that are wound respectively around the several tooth coating sections 132, and the coil connecting conductor wire (the bridge conductor section 149a, the turning section 149b, the slant insertion section 149c) that electrically connects two of the several coils 112.In the impact drill 1, a surface F of a tooth coating section 132 and the projecting end 146 corresponding to the tooth coating section 132 are offset from each other in the circumferential direction, and the coil connecting conductor wire (the turning section 149b) is hooked onto the projecting end 146 and inserted into the surface F of the tooth coating section 132. Therefore, a section (the oblique insertion section 149c) of the conductor wire is inserted obliquely to the top-and-bottom direction from the projecting end 146 to the surface F and suspended on the surface F, making it easier to properly secure the conductor wire to the surface F than if the conductor wire were inserted in the top-and-bottom direction. When the conductor wire being inserted into the tooth coating section 132 is correctly secured, the first of the windings of the conductor wire is suitably formed on the tooth coating section 132.Therefore, each of the second and subsequent windings is suitably designed in the same way as the preceding winding thereof, and the coil 112 is suitably designed as the windings which are wound around the tooth coating section 132.

[0156] Furthermore, the insulator 122 is integrally formed with the stator core 120. Therefore, the projecting end 146 is designed to be as robust as possible, and the formation of the turning section 149b prevents a situation in which the projecting end 146 sags (bent / bent) due to the conductor wire pressed against it and the conductor wire is displaced.

[0157] Furthermore, the projection end 146 features the end face of the extension section 145 of the second projection 144, which forms the fusible link slot 140 and projects from the insulator 122. Additionally, the projection end 146 features the end face of the recess 147, which is recessed into the insulator 122. Therefore, the projection end 146 is simply and effectively designed.

[0158] Furthermore, one tooth coating section 132 has the grooves 135 on which the coil connecting conductor wire (the end of the angled insertion section 149c) is hooked. Therefore, the angled insertion section 149c is inserted as reliably as possible into a suitable position on the one tooth coating section 132.

[0159] Furthermore, half of the coils 112 and half of the coil connecting conductor wire are formed by the continuous conductor wire. Therefore, the number of electrically connected sections is reduced, resulting in a circuit of the coils 112 that has a simple design and good electrical properties.

[0160] Furthermore, the impact drill 1 has the connection unit 114, which has the multiple fusible links 180 that are electrically connected to the multiple coils 112. The insulator 122 has the fusible link slots 140 into which the fusible links 180 are inserted, and the projecting end 146 and the corresponding fusible link slot 140 are continuous with each other. Therefore, the projecting end 146 for the correct insertion of the conductor wire and the corresponding fusible link slot 140, which surrounds the fusible link 180, are formed as a single, lightweight, and compact section.

[0161] It should be noted that the present disclosure is not limited to the aforementioned embodiment, and that, for example, the following modifications are made on a needs basis.

[0162] The motor can be a different type of motor, such as a brushed motor. Additionally, or alternatively, the motor can be an AC (alternating current) motor instead of a DC (direct current) motor.

[0163] The housing can be obtained by integrating any at least two of the motor housing, the output housing, the handle housing and the lower housing, or at least one of these housings can be further subdivided.

[0164] A detachable connection of the multiple power supply lines can be made separately, without bundling the multiple power supply lines at the connection part base and the jaw section of the common power supply-side connection part. Furthermore, a detachable connection of the power supply lines can be made with pawls (locking pawls) (connection projection sections) and pawl receptacles (connected sections) instead of or in conjunction with screws.

[0165] The sensor board may be attached to the insulator rather than the connector. Alternatively, the sensor board may be attached to both the connector and the insulator.

[0166] The insulator can be subdivided.

[0167] The guide sections can be any one or two types of sections that include the screw projection sections, the rib and the projection sections, or alternatively, they can include another type of section in addition to the sections.

[0168] Either the projecting end of the extension section of the second projection or the recess can be omitted. If the projecting end of the extension section of the second projection is omitted, one of two sections raised upwards from the two sides of the bottom of the recess is designated as the projecting end onto which the conductor wire is hooked.

[0169] The coil-related conductor wires can be wound in the opposite direction to the winding direction in the embodiment, and the projection end and the recess on which the conductor wire is hooked can be arranged on one side (first projection side) circumferentially opposite to the side in the embodiment.

[0170] At least one of the types of conductors, including power supply conductors, coil-related conductors, signal conductors, and other conductors, can be obtained by electrically connecting a plurality of short conductors. For example, the coil-connecting conductors can be provided separately from the coils as conductors and can be electrically connected to each other.

[0171] The insulator may be made of paper. The number of intermediate shafts and the number of gears are not particularly limited. The impact drill may be fitted with a power supply cable (power cord) instead of the battery mounting section and may be powered by a commercial power supply (mains power). One of the drilling movement mechanism and one of the hammer movement mechanism may be omitted. The number of coils, the number of fusible links, and the number of power supply leads are not particularly limited. The grooves for guiding the coil conductor wire may be designed to extend one turn around the root of each toothed section. The grooves may be reduced in number and / or length. The number of each type of screw, the number of each type of screw hole, etc., are not particularly limited.The number of protruding sections and the number of holes in the terminal unit are not particularly limited. The number of engaging sections (pin sections) in the terminal unit and the number of engagement sections (outer slots) corresponding to the engaging sections in the stator core are not particularly limited. Each pair of engaging section and engagement section can be made engaged by inserting a rib between a pair of protruding sections, whereas the other engaging sections, connecting sections, screw sections, retaining sections, and mounting sections can be modified to have other structures and configurations. The number, configuration, installation or non-installation, material, structure, shape, etc., of a multitude of components and sections can be modified as desired.

[0172] Furthermore, the present invention can be applied to other types of impact drills, other types of power tools, etc., such as high-performance products including a large chainsaw, a lawnmower, a large blower, a large grinder, etc. 1 impact drill (power tool) 10 Motor 12 Stator 14 Rotor 32 Control 92 permanent magnet 110 Stator core arrangement 112 Coil 114 Connection unit 116 Sensor board 118 PCB press component 120 stator core 122 Insulator 130 teeth 131 Outer groove / outer groove (engagement section) 132 Tooth coating section 135 Nut 140 Fusible connection slots 144 Second lead 145 Extension section 146 End of lead 147 Recess / Cutout 149a Bridge conductor section (coil connecting conductor wire) 149b Turning section (coil connecting conductor wire) 149c Slanted insertion section (coil connecting conductor wire) 162 Partition wall 170 Pen section (engaging section) 172 Screw projection section (guide section) 174 Leading section (leading section) 176 Rib (guide section) 180 Fusible link 187 Stator-side connection part (from power supply line) 188, 200, 228 screw 190 Power supply line-side connection part 196 Connection plate 198 Power supply line F Surface (of tooth coating section)

Claims

[1] Electric working machine (1) with: a motor (10) with a stator (12) with a stator core (120), an insulator (122), and a plurality of coils (112), a rotor (14) which is rotatable about a central axis in relation to the stator (12), and a motor shaft (16) which is fixed to the rotor (14); a sensor board (116) with a rotation detection element designed to detect a rotation of the rotor (14) and output a signal; an output part (6) which is driven by the motor shaft (16); and a connection unit (114) which is fixed to the insulator (122) and a plurality of conductive sheet metal components (152a-152c) with a terminal connected to the plurality of coils (112), and a resin component (150) that is integrally formed with the majority of the sheet metal components (152a-152c); in the the sensor board (116) is fixed to the connection unit (114), the connection unit (114) is screwed to the insulator (122) by a plurality of first screws (188), the sensor board (116) is screwed to the connection unit (114) with a plurality of second screws (228), and the majority of the first screws (188) are located radially outwards from the majority of the second screws (228). [2] Electric machine according to claim 1, wherein at least a part of the majority of the sheet metal components (152a-152c) are located in a radial direction between the first screws (188) and the second screws (228). [3] Electric machine according to claim 1, in which at least a part of the majority of the sheet metal components (152a-152c) are in an axial direction in the same position as the second screws (228). [4] Electric machine according to claim 1, in which a plurality of screw hole sections (168) projecting radially outwards are formed on a circumferential edge of the resin component (150). [5] Electric working machine (1) with: a motor (10) with a stator (12) with a stator core (120), an insulator (122), and a plurality of coils (112), a rotor (14) which is rotatable about a central axis in relation to the stator (12), and a motor shaft (16) which is fixed to the rotor (14); a sensor board (116) with a rotation detection element designed to detect a rotation of the rotor (14) and output a signal; an output part (6) which is driven by the motor shaft (16); and a connection unit (114) which is fixed to the insulator (122) and a plurality of conductive sheet metal components (152a-152c) with a terminal connected to the plurality of coils (112), and a resin component (150) that is integrally formed with the majority of the metal sheet components (152a-152c); at the the sensor board (116) is fixed to the connection unit (114), the resin component (150) has a recess, and the sensor board (116) is arranged in the recess.

Images