ELECTRIC POWER TOOL

Abstract

An electric power tool (1) comprises a motor (4), a dispensing unit (6) driven by the motor (4), a metal housing (22), a cover (23), an electrical component (8), and a battery mounting area (115). The metal housing (22) contains the dispensing unit (6) and extends forward. The cover (23) is made of a synthetic resin and covers at least part of the housing (22). The electrical component (8) is located on one side of a front portion of the housing (22). The battery mounting area (115) has a negative and a positive terminal (116) to which a mounted battery (14) is electrically connected.On an outer surface between a front and a rear surface of the housing (22), a connection area (54) of a grounding wire (56), which is connected to the negative terminal (116) of the battery mounting area (115), is arranged in a conductive state with the outer surface. A subdivision area (60) is formed in the cover (23) and divides between a conductor wire (42) for an electrical component, which is connected to the electrical part (8), and the connection area (54).

Description

TECHNICAL AREA

[0001] The disclosure relates to an electric power tool. The electric power tool is, for example, a striking tool that has a hammer unit as an output unit and causes an anvil to generate an intermittent impact, namely a rotary impact force (rotary hammer force). STATE OF THE ART

[0002] A well-known electric power tool features a light that illuminates the front of an output unit to make a work area more easily visible.

[0003] For example, JP 2024 - 79 576 A discloses a striking tool which has a light which illuminates the front of an anvil projecting forward from the front end of a hammer housing which accommodates a hammer unit as a dispensing unit.

[0004] A rechargeable electric power tool that uses a battery as a power source may experience a control malfunction due to electrical noise emitted by high-voltage power transmission lines when used near these lines. To prevent this malfunction, measures are taken to connect the negative terminal (grounding wire) of the battery to a metal housing, such as a hammer housing, via a grounding wire (hereinafter referred to as a "ground wire").

[0005] However, if the grounding wire is installed on the rear surface of the housing, it is necessary to ensure sufficient space to, for example, attach a metal terminal block connected to the grounding wire with screws from the back. Consequently, the overall length in the front-to-back direction increases, thus preventing a reduction in size.

[0006] Therefore, it is conceivable that the grounding wire is connected to the lower or side surface of the housing using a screw or, for example, a terminal entry structure such as a receptacle (plug socket). This allows for a connection area between the front and rear surfaces of the housing, thus eliminating the need to provide space at the rear.

[0007] However, in a case where an electrical part (electrical component), such as a light, is located at the front of the output unit, as in JP 2024-79576A, if a conductor wire for an electrical component connected to the electrical part is routed (wired) along the outer surface of the housing, the screws used to install the terminal fitting and the terminals may come into contact with the conductor wire for the electrical component. The ground wire may also come into contact with the conductor wire for the electrical component. In this case, vibrations generated during tool use may cause wear on the wires or cause the screws to loosen if the connection area is secured with screws.

[0008] It is therefore an objective of the present disclosure to provide an electric power tool that does not hinder miniaturization even when a grounding wire and a conductor wire for an electrical component are laid (wired), and effectively avoids the occurrence of defects (faults) associated with vibration, such as wire wear. BRIEF SUMMARY

[0009] The problem described above is solved by an electric power tool according to claim 1.

[0010] According to one embodiment of the present disclosure, an electric power tool comprises a motor, an output unit driven by the motor, a metal housing, a cover, an electrical component, and a battery mounting area. The metal housing accommodates the output unit and extends forward. The cover is made of a synthetic resin and covers at least part of the housing. The electrical component is located on one side of a front portion of the housing. A battery, serving as a power source, can be mounted in the battery mounting area. The battery mounting area has a positive and a negative terminal (positive and negative terminals) to which the mounted battery is electrically connected.On an outer surface between a front and a rear face of the housing, a connection area for a grounding wire, which is connected to the negative terminal of the battery mounting area, is arranged in a conductive state with the outer surface. A subdivision area is formed in the cover. The subdivision area separates a conductor wire for an electrical component, which is connected to the electrical part, from the connection area.

[0011] In the disclosure, the “side of the front area of ​​the housing” on which the electrical part is arranged includes both a case in which the electrical part is arranged directly on the front area of ​​the housing and a case in which the electrical part is not arranged directly on the housing, but in the vicinity of the front area of ​​the housing.

[0012] The design allows the grounding wire to be connected between the front and rear surfaces of the housing, eliminating contact between the screw used to install (mount) the grounding wire and the terminals of an electrical component, or between the grounding wire and the conductor of an electrical component. Consequently, even when the grounding wire and the conductor of an electrical component are routed, miniaturization is not impeded, and the occurrence of vibration-related defects, such as wire wear, can be effectively avoided. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view from the front of a bump key. Fig. Figure 2 is a middle vertical cross-sectional view of the bump key. Fig. Figure 3 is a perspective exploded view of the front area of ​​the impact key, which includes part of a main body housing. Fig. Figure 4 is an enlarged cross-sectional view along line AA in Fig. 2. Fig. Figure 5 is a perspective exploded view of the front area of ​​the bump key, seen from the rear. Fig. Figure 6 is an enlarged cross-sectional view along line BB in Fig. 2. Fig. Figure 7 is an enlarged cross-sectional view along line CC in Fig. 2. DETAILED DESCRIPTION OF EXECUTION FORMS

[0013] In one embodiment of the present disclosure, the electric power tool may have a main body, which includes (accommodates) the motor and the output unit and extends in a front-to-back direction, and a handle extending downwards from the main body. The battery mounting area may be located at a lower end of the handle. The connection area may be located on a lower surface of the housing. The subdivision area is located on a lower surface of the cover.

[0014] This configuration allows the grounding wire to be connected to the housing on the lower side of the main body, where the grounding wire comes close to the negative terminal of the battery mounting area.

[0015] In one embodiment of the present disclosure, the subdivision area may have a curved area which is bent to one side of the conductor wire for an electrical component, and the cover, the subdivision area and the curved area form a wiring path (cable tray) of the conductor wire for an electrical component.

[0016] The configuration eliminates the likelihood that the conductor wire for an electrical component, for example, will be pinched in a fitting surface of the housing during assembly and repair.

[0017] In one embodiment of the present disclosure, an outer housing that partially covers the cover can be arranged on a lower side of the cover, and the connecting area and the subdivision area can be arranged between the cover and the outer housing.

[0018] With this configuration, the outer casing can be used to connect the grounding wire and to route the lead wire for an electrical component, and the grounding wire and the lead wire for an electrical component are protected.

[0019] In one embodiment of the present disclosure, the subdivision area can be formed integrally with the cover.

[0020] The subdivision area can be easily configured.

[0021] In one embodiment of the present disclosure, the connection area can be a screw fastening area, and the subdivision area can be positioned in a screw extraction direction with which the grounding wire is installed on the screw fastening area, and is close to or in contact with a head of the screw.

[0022] This configuration effectively prevents the screw from being removed from the subdivision area.

[0023] In one embodiment of the present disclosure, the electrical part can be, for example, a light for illumination.

[0024] This configuration effectively prevents wear and tear and damage to the conductor wire of an electrical component, even if the light is located on the side of the front of the housing.

[0025] In one embodiment of the present disclosure, the output unit may be a hammer unit that applies intermittent hammering (striking) in a rotary direction to an anvil projecting forward, the housing may be a hammer housing that supports the anvil, and the cover may be a hammer housing cover that covers an outside of the hammer housing.

[0026] The configuration can effectively prevent screw removal and wear and tear on the grounding wire and the lead wire for an electrical component in a striking tool that generates a relatively large vibration during its use.

[0027] In one embodiment of the present disclosure, a connection area can be a screw fastening area, the screw fastening area can be formed on a lower surface of the housing and project downwards through the cover, the subdivision area can extend in a front-back direction on a lower surface of the cover and subdivide between the screw fastening area and the conductor wire for an electrical component, and the subdivision area can be positioned in a removal direction of a screw with which the grounding wire is installed on the screw fastening area and is close to or in contact with a head of the screw.A curved area, bent to one side of the conductor wire for an electrical component, may be formed at a lower end of the subdivision area, and a wiring path of the conductor wire for an electrical component may be formed linearly through the cover, the subdivision area and the curved area in an overlapping state with the screw fastening area and the grounding wire in a left-right direction.

[0028] This configuration allows the screw mounting area and the grounding wire to be arranged in a space-saving manner.

[0029] The following describes an embodiment of the disclosure based on the drawings. Fig. Figure 1 is a perspective view from the front of a bump key, which is an example of an electric power tool, and Fig. Figure 2 is a vertical mid-section view of the bump key.

[0030] The (rechargeable) impact wrench 1 has a main body 2 and a handle 3. The main body 2 extends in the front-to-back direction, and the handle 3 extends downwards from the main body 2. The main body 2 accommodates a motor 4, a reduction unit 5, a hammer unit 6, and an anvil 7 from the rear. The anvil 7 has a front end to which a socket insert (not shown), projecting forwards from the main body 2, can be mounted. The hammer unit 6 is an example of the output unit of the disclosure.

[0031] A light unit 8, which illuminates the front of the anvil 7, is arranged on the front surface of the main body 2. The light unit 8 is an example of light as an electrical part of the revelation.

[0032] The handle 3 accommodates a switch 9, a control 10, and a terminal block 11. A push button 12, projecting forward from the lower side of the main body 2, is located near the switch 9. A forward / reverse switch 13, which controls (changes) the direction of rotation of the anvil 7, is located on the upper side of the switch 9. A (rechargeable) battery pack 14, serving as a power source, is attached to and removable from the lower end of the handle 3. The battery pack 14 is an example of a battery of the revelation.

[0033] The impact wrench 1 has an outer wall formed from a main body housing 20, a rear cover 21, a hammer housing 22, a hammer housing cover 23 and a shock absorber 24.

[0034] First, the main body housing 20 is made of a synthetic resin and extends from the central area in the front-back direction of the main body 2 to the handle 3. As also in Fig. As shown in Figure 3, the main body housing 20 is formed by attaching a pair of right and left housing halves 20a, 20b to each other with a plurality of screws 25 from the right side.

[0035] The rear cover 21 is made of a synthetic resin and has a cap shape that covers the rear area of ​​the main body 2. The rear cover 21 is attached by screws to a tubular section 26 formed on the upper part of the main body housing 20 at two positions, one on the right and one on the left, from the rear. The motor 4 is housed inside the rear cover 21 and the tubular section 26.

[0036] The hammer housing 22, which is a tubular metal body, is attached to the tubular area 26 by screws, its rear portion being held by the tubular area 26 and covering the front portion of the main body 2. The hammer housing 22 is an example of a metal housing of the disclosure.

[0037] The tubular section 26 has four upper, lower, left, and right corners, at which screw receptacles 27 project in a front view. The hammer housing 22 also has four upper, lower, left, and right corners, at which screw insertion areas 28 are arranged, projecting from the rear. The hammer housing 22 is fastened by four bolts 29, which are screwed through the screw receptacles 27 from the rear and screwed into the screw insertion areas 28.

[0038] The reduction unit 5, the hammer unit 6, and the rear section of the anvil 7 are mounted inside the hammer housing 22. A pair of arm sections 30, projecting radially outwards, are arranged on the rear section of the anvil 7. The anvil 7 projects forward through a small-diameter front cylinder section 31 formed on the front section of the hammer housing 22. An insert sleeve 32, which rotatably supports the anvil 7, is held inside the front cylinder section 31. An oil seal 33 is held against the front section of the insert sleeve 32.

[0039] As also in Fig. As shown in Figure 4, a groove 34 is formed on the front surface of the hammer housing 22 and radially outside the front cylinder section 31. The groove 34 has an open front surface in an annular shape on a concentric circle with the axes of the anvil 7 and the front cylinder section 31. The light unit 8 is arranged in the groove 34. As also shown in Fig. As shown in Figure 5, the light unit 8 comprises a foam plate 35, an LED circuit board 36, and a circuit board cover 37. The foam plate 35 is ring-shaped and is located on the bottom surface of the groove 34. The LED circuit board 36 is located on the front side of the foam plate 35. The LED circuit board 36 is ring-shaped and has a front surface on which three LEDs 38 are arranged at equal intervals in a circumferential direction. The circuit board cover 37 is ring-shaped and covers the LED circuit board 36 from the front, and is translucent. A plurality of lens units 39 are formed on the front surface of the circuit board cover 37 at equal intervals in the circumferential direction.

[0040] A stop ring 40, which holds the circuit board cover 37, is locked to the outer circumference of the front cylinder area 31. An extraction area 41 is formed, pointing downwards, on the lower area of ​​the LED circuit board 36. Light guide wires 42 are led out (pulled out) from the extraction area 41. The light guide wire 42 is an example of the guide wire for an electrical component of the disclosure.

[0041] A pair of bearing pieces 43, to which the extraction area 41 is fitted from the rear, is formed on the lower part of the circuit board cover 37, pointing downwards. The LED circuit board 36 is received in the circuit board cover 37 from the rear in a position where the extraction area 41 is fitted between the bearing pieces 43. In this state, each lens unit 39 of the circuit board cover 37 is positioned at the front of each LED 38 of the LED circuit board 36. A locating groove 44 is formed on the lower part of the front surface of the hammer housing 22. The locating groove 44 communicates with the groove 34 and opens downwards. When received in the groove 34, the extraction area 41 of the LED circuit board 36 and the bearing pieces 43 of the circuit board cover 37 are fitted into the locating groove 44 and project downwards from the hammer housing 22.

[0042] A pair of cutouts 45 is formed on the right and left sides of the front surface of the hammer housing 22. An annular groove 46 is formed on the outer circumference of the hammer housing 22 at the rear of the cutouts 45.

[0043] The hammer housing cover 23 is made of a synthetic resin and has a ring shape. The hammer housing cover 23 covers the front area, excluding the front end, of the hammer housing 22 that projects from the tubular area 26. An upper cover area 50 and two lower cover areas 51 are arranged at the rear of the hammer housing cover 23. The upper cover area 50 covers the screw insertion areas 28 on the upper right and left sides of the hammer housing 22 from the front. The lower cover areas 51 independently cover the respective screw insertion areas 28 on the lower right and left sides of the hammer housing 22. A slot 52, extending forward from the rear end, is formed between the lower cover areas 51. The hammer housing cover 23 is an example of the cover of the disclosure.

[0044] As also in Fig. As shown in Figure 6, an extension area 53 is formed on the lower portion of the tubular area 26. The extension area 53 projects forward and covers the lower surface of the hammer housing cover 23. Respective halves of the extension area 53 are formed on the right and left housing halves 20a and 20b, respectively, and have front portions that are joined by the screw 25. The extension area 53 is an example of the outer housing covering the cover, as disclosed in the disclosure.

[0045] An earthing area 54 is integrally formed at a position offset to the left on the lower surface of the hammer housing 22. The earthing area 54 is an example of the connection and screw fastening area of ​​the earthing wire of the disclosure. The lower surface of the hammer housing 22 is an example of the outer surface between the front and rear faces of the housing.

[0046] The grounding area 54 has a plate shape defined in the top-bottom and front-back directions and projects downwards through the slot 52 into the extension area 53. The grounding area 54 is positioned at the rear of the screws 25 that secure the extension area 53. A threaded hole 55, penetrating in the left-right direction, is formed in the grounding area 54. As shown in Fig. As shown in Figure 7, the grounding area 54 is arranged to connect the negative terminal of the terminal block 11 to the hammer housing 22 via a grounding wire 56. The grounding wire 56 is installed in a conductive state by screwing a screw 58, which passes through a terminal fitting 57, into the threaded hole 55 in such a way that the terminal fitting 57, which is connected to the end of the grounding wire 56, is in contact with the right side of the grounding area 54. As shown in Figure 7, the grounding area 54 is arranged to connect the negative terminal of the terminal block 11 to the hammer housing 22 via a grounding wire 56. Fig. As shown in Figure 2, the grounding wire 56 passes between the hammer housing cover 23, together with the hammer housing 22 and the forward / reverse switch 13, in the extension area 53 and is led out to the rear. The grounding wire 56 is an example of the grounding wire of the disclosure.

[0047] A subdivision area 60 is formed on the lower surface of the hammer housing cover 23. The subdivision area 60 has a plate-like shape that projects downward from the right end of the slot 52 and extends in the front-back direction. The subdivision area 60 is positioned on the right side of the screw 58 with which the grounding wire 56 is installed and is close to the head of the screw 58 when the hammer housing cover 23 is mounted. A curved piece 61, bent to the right, is formed along its entire length at the lower end of the subdivision area 60. Accordingly, the subdivision area 60 and the curved piece 61 project from the lower surface of the hammer housing cover 23 in an inverted L-shape in a front view. The curved piece 61 is an example of the curved area arranged in the subdivision area of ​​the disclosure.

[0048] Thus, a linear wiring path 62 is formed on the lower side of the hammer housing cover 23. The wiring path 62 is enclosed by the lower surface of the hammer housing cover 23, the subdivision area 60, and the curved section 61, and opens to the right. A front wall section 63, curved to the left, is formed at the front end of the subdivision area 60. The front wall section 63 is positioned between the grounding area 54 and the screw 25, which joins the extension area 53.

[0049] As in Fig. As shown in Figure 7, the light guide wires 42, which are led out from the extraction area 41 of the LED board 36, pass through the wiring path 62 on the right side of the subdivision area 60 in the extension area 53, pass between the hammer housing cover 23 together with the hammer housing 22 and the forward / reverse switch 13, and are led out to the rear. Accordingly, the subdivision area 60, which is made of a synthetic resin, is inserted between the light guide wires 42 and the terminal metal fitting 57 of the grounding wire 56 and the screw 58. Therefore, contact between the light guide wires 42 and the terminal metal fitting 57 and the screw 58 is prevented. Furthermore, the curved piece 61 at the lower end of the subdivision area 60 restricts the movement of the light guide wires 42 to the lower side of the subdivision area 60.Consequently, the probability that the light guide wires 42 run around the lower side of the subdivision area 60 and come into contact with the connecting metal fitting 57 and the screw 58 is eliminated.

[0050] As in Fig. 3 to Fig. As shown in Figure 5, installation pieces 65 are formed on the right and left sides of the hammer housing cover 23. The installation pieces 65 extend rearward from the rear end of the hammer housing cover 23 between the upper cover area 50 and the lower cover areas 51. A locking piece 66, bent outward to the right or left side, is formed at the rear end of each installation piece 65. A through-hole 67 is formed such that it passes through each installation piece 65. Projections 68 are formed on the right and left side surfaces of the hammer housing 22 in a mounting position of the hammer housing cover 23. Each projection 68 is locked in (with) the through-hole 67 of the installation piece 65 for positioning the hammer housing cover 23 relative to the hammer housing 22.

[0051] Fitting pieces 70 are formed on the right and left sides of the tubular section 26. The fitting pieces 70 are fitted between the upper cover section 50 and the lower cover section 51 of the hammer housing cover 23. A recessed area 71, which covers the mounting pieces 65 of the hammer housing cover 23 from the outside, is formed on the inner surface of each fitting piece 70. A locking groove 72, with which the locking piece 66 of the mounting piece 65 is locked, is formed at the rear end of each recessed area 71. The locking piece 66 is locked in the locking groove 72 to bring the inner surface of the recessed area 71 close to the outer surface of the mounting piece 65, thereby holding the mounting piece 65 and preventing removal (dislodging) of the hammer housing cover 23.At the same time, the front end of the hammer housing cover 23 is positioned on the outside in the radial direction at the rear end of the annular groove 46 of the hammer housing 22.

[0052] The shock absorber 24 has an annular shape that covers the front end of the hammer housing 22 at the front of the hammer housing cover 23. The shock absorber 24 is made of a synthetic resin and is formed from an elastic material, such as an elastomer. A pair of locking projections 75, which engage with the cutout 45 on the front surface of the hammer housing 22, are formed on the right and left sides of the rear surface of the shock absorber 24. A hook 76, projecting around the entire circumference to the inner circumferential side, is formed at the rear end of the shock absorber 24. Positioning recesses 77, into which the lens units 39 of the circuit board cover 37 are fitted, are formed on the inner circumference of the front surface of the shock absorber 24.A cutout area 78, into which the bearing pieces 43 of the circuit board cover 37 are fitted, is formed on the lower part of the rear surface of the shock absorber 24. The shock absorber 24 is positioned with respect to the circuit board cover 37 by fitting each lens unit 39 of the circuit board cover 37 into each positioning recess area 77 and fitting the bearing pieces 43 into the cutout area 78. In this state, the locking projections 75 of the shock absorber 24 are aligned with respect to the cutouts 45 of the hammer housing 22, and the hook pieces 76 are locked in the annular groove 46. The shock absorber 24 is then mounted to the front end of the hammer housing 22 on the front side of the hammer housing cover 23. In this state, each lens unit 39 is exposed to the front surface of the shock absorber 24, as shown in [Figure 1]. Fig. 1 shown.

[0053] The motor 4 is an inside-rotor brushless motor comprising a stator 80 and a rotor 81 passing through the stator 80. The stator 80 is held coaxially in the tubular section 26. Six coils 83, forming a three-phase winding wire, are wound around the stator 80 via a front and a rear insulating piece 82. As shown in Fig. As shown in Figure 2, a sensor circuit board 84 is arranged on the front surface of the front insulating piece 82. The sensor circuit board 84 has a rotation detection element (not shown) for detecting the rotational position of the rotor 81. Signal lines 85, which output rotation detection signals, are led downwards from the lower region of the sensor circuit board 84. A terminal unit 86, to which the three-phase winding wire is connected, is arranged on the lower region of the rear insulating piece 82. Three-phase power lines 87 are led downwards from the terminal unit 86.

[0054] The rotor 81 has a rotating shaft 90 at its center. The rotating shaft 90 has a rear end that is supported by a bearing 91, which is held against the front inner surface of the cover 21. A fan wheel 92 is arranged on the rotating shaft 90 between the stator 80 and the bearing 91. A plurality of inlet openings 93 are formed on the right and left side surfaces of the tubular area 26. A plurality of outlet openings 94 are formed on the right and left side surfaces of the rear cover 21.

[0055] A bearing box 95 is arranged in the tubular area 26 at the front of the motor 4. The bearing box 95 has a disc-shaped rear view and is mounted to the rear end of the hammer housing 22 to block (cover) the rear surface of the hammer housing 22. The front portion of the rotary shaft 90 passes through the bearing box 95 and is supported by a bearing 96, which is held on the side of the rear surface of the bearing box 95.

[0056] The reduction unit 5 comprises a drive pinion 100, an internal gear 101, planet gears 102, and a support section 103. The drive pinion 100 is formed at the front end of the drive shaft 90 and projects into the hammer housing 22. The internal gear 101 is held in the rear section of the hammer housing 22, its rotation being restricted relative to the bearing housing 95. Three planet gears 102 are arranged between the drive pinion 100 and the internal gear 101 and mesh with both the drive pinion 100 and the internal gear 101. The support section 103 supports the respective planet gears 102 via three pins 104. The rear end of the support section 103 is supported by a bearing 97, which is located on the front surface of the bearing housing 95. A spindle 105, which extends forward in the center of the hammer housing 22, is integrally formed with the support area 103.

[0057] The hammer unit 6 comprises a hammer 106, which is mounted externally on the spindle 105, and a coil spring 107, which biases the hammer 106 forward. As in Fig. As shown in Figure 6, the hammer 106 is coupled in the direction of rotation by three balls 108 arranged between the hammer 106 and the spindle 105. Cam grooves 109, over which the balls 108 are guided, are formed on the inner circumferential surface of the hammer 106 and the outer circumferential surface of the spindle 105. The helical spring 107 is mounted externally on the spindle 105 between the support area 103 and the hammer 106 and biases the hammer 106 forward. The hammer 106 has a circular recess on its front surface and receives the rear area of ​​the anvil 7, which has the arm areas 30, in the recess. As shown in Fig.As shown in Figure 6, a pair of stops 110 are formed on the inner circumferential surface of the recessed area. The stops 110 can engage with the arm sections 30 of the anvil 7 in the direction of rotation. A closed-end hole 111 is formed in the center of the shaft of the anvil 7, extending from the rear end. A small-diameter section 112, located at the front end of the spindle 105, is inserted coaxially into the closed-end hole 111.

[0058] A battery mounting area 115 is located at the lower end of the handle 3. The battery pack 14 slides from the front (is moved from the front) so that it is mounted in (on) the battery mounting area 115.

[0059] The terminal block 11 is located in the battery mounting area 115. The terminal block 11 has three terminals 116 which are electrically connected to the mounted battery pack 14. Of these, two terminals 116 are for supplying positive and negative power and one terminal 116 is for communication (transmission) of temperature information and the like.

[0060] The controller 10 is housed in the battery mounting area 115 on the upper side of the terminal block 11. The controller 10 includes a control circuit board 117. The control circuit board 117 has a CPU and memory, which is connected to the CPU for controlling the rotation of the motor 4 and the operation of the light unit 8. A connector area 118 and a switching panel 119 are arranged on the control circuit board 117. Lead wires, which are wired to the respective electrical components, are connected to the connector area 118. The switching panel 119 is exposed to the front upper surface of the battery mounting area 115 and allows switching of a hammer force and modes, as well as switching of the active / inactive state of the light unit 8, i.e., whether it is coordinated with the ON / OFF of the switch 9 or not.

[0061] The signal lines 85, which come out of the sensor switching board 84, and the power lines 87, which come out of the connection unit 86, pass behind the switch 9 in the handle 3 and are connected to the connector area 118 on the control switching board 117. A connecting wire (not shown), which is routed downwards from the switch 9, is also connected to the connector area 118.

[0062] After the light conductor wires 42 pass between the hammer housing 22 and the forward / reverse switch button 13 and are led out to the rear, they pass behind the switch 9 in the handle 3 and are connected to the connector area 118.

[0063] The grounding wire 56 also passes between the hammer housing 22 and the forward / reverse switch 13 and exits to the rear. The grounding wire 56 then passes behind the switch 9 at the handle 3, behind the control unit 10, and is connected to the negative terminal 116 of the terminal block 11. Accordingly, when the battery pack 14 is installed, the negative terminal of the battery pack 14 is electrically connected to the hammer housing 22 via the negative terminal 116 and the grounding wire 56.

[0064] In the configured impact wrench 1 described above, the trigger 12 is pressed and actuated with one hand gripping the handle 3. The switch 9 is then turned ON, and the control board 117 supplies a three-phase current to the motor 4 from the power source of the battery pack 14. Accordingly, the drive shaft 90 rotates together with the rotor 81, and the spindle 105 rotates at a reduced speed via the reduction unit 5. As the spindle 105 rotates, the hammer 106 rotates via the balls 108. As the hammer 106 rotates, the anvil 7 rotates to allow tightening of a bolt or the like with a socket wrench.

[0065] The fan wheel 92 rotates in conjunction with the rotation of the rotating shaft 90. Outside air, drawn in through the inlet openings 93, is then expelled through the outlet openings 94, creating an internal airflow that cools the motor 4. When the light is activated by the switch panel 119, current flows to the LED circuit board 36 of the light unit 8 in conjunction with the ON (switching) of the switch 9, and each LED 38 illuminates. The light from the LED 38 is then projected forward by each lens unit 39.

[0066] As the tightening process progresses and the torque of the anvil 7 increases, the hammer 106 retracts against the preload of the coil spring 107 when a rotational differential relative to the spindle 105 has been generated. Specifically, the hammer 106 rotates and retracts while each ball 108 rolls backward along each cam groove 109. Then, when the stops 110 are released from the arm sections 30 of the anvil 7, the hammer 106 advances by means of the preload of the coil spring 107 and by means of the guidance of each cam groove 109, while rotating. Accordingly, the stops 110 re-engage with the arm sections 30, causing the anvil 7 to generate a rotational impact force, i.e., a strike. The strike is repeated intermittently to perform further tightening.

[0067] The negative terminal of the battery pack 14 is electrically connected to the metal hammer housing 22 via the negative terminal 116 of the terminal block 11 and the grounding wire 56. Therefore, when the impact wrench 1 is used in the vicinity of high-voltage power lines, the control unit 10 is not affected by electrical noise.

[0068] The grounding wire 56 is located on the lower side of the hammer housing 22 and is fastened with screws between the front and rear surfaces of the hammer housing 22. Accordingly, when the grounding wire 56 is present, the overall length in the front-to-back direction of the main body 2 does not increase. Furthermore, the grounding wire 56 is separated from the light conductors 42 by the subdivision 60 of the hammer housing cover 23. In this respect, even if vibration occurs during use, contact between the light conductors 42 and the screw 58, with which the grounding wire 56 is installed, is avoided, and contact between the two conductors 42 and 56 is also prevented. Furthermore, the subdivision 60 is located close to the head of the screw 58.Therefore, even if the screw 58 loosens due to a vibration, removal of the screw 58 is avoided (prevented), and the connection state of the earthing conductor wire 56 is maintained.

[0069] The impact wrench 1 of the embodiment described above comprises the motor 4, the hammer unit 6 driven by the motor 4, the metal hammer housing 22, the hammer housing cover 23 made of synthetic resin, the light unit 8 arranged on the front portion of the hammer housing 22, and the battery mounting area 115, on which the battery pack 14 can be mounted as a power source. The hammer housing 22 accommodates the hammer unit 6 and extends forward. The hammer housing cover 23 covers the front portion of the hammer housing 22. The battery mounting area 115 has the positive and negative terminals 116, to which the mounted battery pack 14 is electrically connected.

[0070] Furthermore, the grounding area 54 is formed on the lower surface of the hammer housing 22, and the subdivision area 60 is formed at the hammer housing cover 23. The grounding area 54 is the connector and screw fastening area of ​​the grounding wire 56, which is connected to the negative terminal 116 of the battery mounting area 115. The subdivision area 60 divides between the lighting wires 42, which are connected to the lighting unit 8, and the grounding area 54.

[0071] This configuration allows the grounding wire 56 to be fastened with screws between the front and rear surfaces of the hammer housing 22, and it eliminates contact between the screw 58, with which the connecting metal fitting 57 is installed, and the light conductors 42, or between the grounding wire 56 and the light conductors 42. Accordingly, even if the grounding wire 56 and the light conductors 42 are present, reduction in size is not prevented, and the occurrence of defects (faults) associated with vibration, such as loosening of the screw 58 and wear of both conductors 42 and 56, can be effectively avoided.

[0072] The impact wrench 1 comprises the main body 2 and the handle 3. The main body 2 contains (accompanies) the motor 4 and the hammer unit 6 and extends in the front-back direction. The handle 3 extends downwards from the main body 2. The battery mounting area 115 is located at the lower end of the handle 3. The grounding area 54 is located on the lower surface of the hammer housing 22. The subdivision area 60 is located on the lower surface of the hammer housing cover 23.

[0073] Accordingly, the grounding wire 56 can be attached with screws to the hammer housing 22 on the lower side of the main body 2, where the grounding wire 56 comes close to the negative terminal 116 of the battery mounting area 115.

[0074] The subdivision area 60 has the bent piece 61, which is bent towards the side of the light guide wires 42, and the hammer housing cover 23, the subdivision area 60 and the bent piece 61 form the wiring path 62 of the light guide wires 42.

[0075] Accordingly, the possibility is eliminated that the light conductor wires 42 run around the subdivision area 60, move to the side of the grounding conductor wire 56 and come into contact with the screw 58.

[0076] The extension area 53, which partially covers the hammer housing cover 23, is located on the lower side of the hammer housing cover 23, and the grounding area 54 and the subdivision area 60 are located between the hammer housing cover 23 and the extension area 53.

[0077] Accordingly, the extension area 53 can be used to form the screw fastening of the earthing conductor wire 56 and to lay the light conductor wires 42, and both conductor wires 42, 56 are protected.

[0078] The subdivision area 60 is integrally formed with the hammer housing cover 23. Accordingly, the subdivision area 60 can be made lighter.

[0079] The subdivision area 60 is positioned in a withdrawal direction of the screw 58, with which the earthing conductor wire 56 is installed on the earthing area 54, and is close to the head of the screw 58.

[0080] Accordingly, the subdivision area 60 can effectively prevent the removal (detachment) of screw 58.

[0081] The electrical part is the lighting unit 8.

[0082] Accordingly, wear and damage to the light guide wires 42 can be effectively avoided, even if the light unit 8 is located at the front of the hammer housing 22.

[0083] The output unit is the hammer unit 6, which applies intermittent hammering in the direction of rotation of the anvil 7, which projects forward. The housing is the hammer housing 22, which supports the anvil 7. The cover is the hammer housing cover 23, which covers the outside of the hammer housing 22.

[0084] Accordingly, removal of screw 58 and wear of both conductor wires 42, 56 can be effectively avoided with the impact wrench 1, which generates a relatively large vibration during its use.

[0085] The grounding area 54 is formed on the lower surface of the hammer housing 22 and projects downwards through the hammer housing cover 23.

[0086] The subdivision area 60 extends in the front-back direction on the lower surface of the hammer housing cover 23 and divides between the grounding area 54 and the light conductor wire 42. Furthermore, the subdivision area 60 is positioned in the extraction direction of the screw 58, with which the ground conductor wire 56 is installed on the grounding area 54, and is close to the head of the screw 58.

[0087] The curved piece 61, which is bent towards the side of the light conductor wires 42, is formed at the lower end of the subdivision area 60. The wiring path 62 of the light conductor wires 42 is formed linearly in the left-right direction through the hammer housing cover 23, the subdivision area 60 and the curved piece 61 in an overlapping state with the grounding area 54 and the grounding conductor wire 56.

[0088] Accordingly, the earthing area 54 and the conductor wire 56 can be arranged in a space-saving manner.

[0089] The following describes examples of modifications to the revelation.

[0090] In the embodiment described above, the grounding area, as the screw mounting area, is located in a position offset to the left of a position directly below the hammer housing. However, the screw mounting area can be positioned directly below the metal housing or in a position offset to the right. The position of the screw mounting area can be shifted to either the front or rear of the position described above. The screw mounting area is not limited to the one that is integrally formed with the housing as in the embodiment described above, but can be formed by attaching a separate body to the housing.

[0091] The subdivision area can be in contact with the head of the screw to which the grounding wire is attached. The subdivision area can be longer or shorter in the front-to-back direction than that of the embodiment described above. The curved section is not limited to the curved piece of the embodiment described above, and the front and rear lengths of the curved section can be modified, and the shape can be changed if necessary. The front wall piece can also be modified to be longer in the left-to-right direction than that of the embodiment described above. However, a curved section or a front wall piece is not required.

[0092] In the embodiment described above, the grounding area is located on the left side, and the subdivision area is located on the right side. However, the arrangement of both left and right can be reversed.

[0093] The subdivision area is not limited to the one that is integrally formed with the cover, but can be formed by attaching a separate body to the cover.

[0094] In the embodiment described above, the grounding area and the subdivision area are located on the lower surface of the hammer housing. However, as long as they are situated between the front and rear faces of the housing, the grounding area and the subdivision area can be located on the side surface or the upper surface of the housing.

[0095] In the embodiment described above, the slot through which the grounding section passes is provided in the hammer housing cover. However, a through-hole through which the grounding section passes can be provided instead of the slot. Furthermore, the grounding section can be located at the rear of the cover to avoid interference with it. In this case, it is only necessary to form the subdivision area by extending it from the rear end of the cover.

[0096] In the embodiment described above, the subdivision area is located at the hammer housing cover. However, the subdivision area can also be located at the shock absorber, or separate subdivision areas can be located at both the hammer housing cover and the shock absorber.

[0097] In the embodiment described above, the screw fastening area is shown as an example of the connection area. However, the connection area is not limited to the screw fastening area and can be a different structure. The connection area can be a terminal entry structure, such as a plug socket (receptacle). In this case, miniaturization is not prevented, and wire wear can be effectively avoided.

[0098] The light at the front of the housing is not limited to that of the embodiment described above. The number of LEDs can be increased or decreased, or the mounting structure of the LED board and the board cover can be modified. The light does not have to be ring-shaped, like the light unit of the embodiment described above.

[0099] The light is not limited to the one installed directly on the front of the housing. For example, the light can be located on the front of the extension section. In this case, the partition area can still be used to separate the connection area from the light guide wire. The extension section can be designed to be larger in the circumferential direction than that of the embodiment described above.

[0100] The electrical component is not limited to the light for illumination. For example, the electrical component can be a lamp that indicates an operating status, or it can be an operating unit such as a button, a switch, or a rotary knob.

[0101] The motor does not need to be brushless. The reduction unit and the hammer unit are not limited to those of the embodiment described above.

[0102] The impact tool can be an angled impact wrench in which a spindle is perpendicular to an anvil, or it can be an impact wrench. However, the disclosure is not limited to these impact tools but is equally applicable to other electrical power tools, such as a vibratory impact drill. Accordingly, the metal housing is not limited to the hammer housing, and the cover is not limited to the hammer housing cover. A shock absorber is not required. The housing shape and the mounting structure forming the outer wall are not limited to those of the embodiment described above.

[0103] In the embodiment described above, the connection area and the subdivision area are provided as countermeasures against high voltage. However, the disclosure is equally applicable to countermeasures against electromagnetic interference (EMI) and countermeasures against static electricity. When the disclosure is applied to countermeasures against EMI or countermeasures against static electricity, the grounding wire need not necessarily be connected only to the negative terminal of the battery mounting area. For example, in the case of a countermeasure against EMI, the grounding wire can be connected between an electromagnetic steel plate of the stator and a metal part, such as the hammer housing.

[0104] It is explicitly emphasized that all features disclosed in the description and / or the claims are to be considered separate and independent of one another for the purposes of the original disclosure as well as for the purpose of limiting the claimed invention, irrespective of the combinations of features in the embodiments and / or the claims. It is explicitly stated that all range specifications or specifications of groups of units disclose every possible intermediate value or subgroup of units for the purposes of the original disclosure as well as for the purpose of limiting the claimed invention, in particular also as a boundary of a range specification. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2024 - 79 576 A [0003, 0007]

Claims

[1] Electric power tool (1), with a motor (4), an output unit (6) driven by the motor (4), a metal housing (22) that accommodates the output unit (6) and extends forward, a cover (23) made of synthetic resin which covers at least part of the housing (22), an electrical part (8) which is arranged on one side of a front area of ​​the housing (22), a battery mounting area (115) on which a battery (14) can be mounted as a power source, wherein the battery mounting area (115) has a positive and a negative terminal (116) with which the mounted battery (14) is electrically connected, wherein a connection area (54) of an earthing wire (56) which is connected to the negative terminal (116) of the battery mounting area (115) is arranged in a conductive state with the outer surface between a front and rear surface of the housing (22), and a subdivision area (60) is formed in the cover (23) in which the subdivision area (60) divides between a conductor wire (42) for an electrical component, which is connected to the electrical part (8) and the connection area (54). [2] Electric power tool (1) according to claim 1, further comprising a main body (2) which accommodates the motor (4) and the output unit (6) and extends in a front-back direction, and a handle (3) extending downwards from the main body (2), wherein the battery mounting area (115) is located at a lower end of the handle (3), the connection area (54) is located on a lower surface of the housing (22), and the subdivision area (60) is arranged on a lower surface of the cover (23). [3] Electric power tool (1) according to claim 2, wherein the connection area (54) protrudes downwards from the lower surface of the housing (22) through the cover (23), the subdivision area (60) projects downwards from the lower surface of the cover (23), and the conductor wire (42) for an electrical component is laid in a front-back direction on an opposite side of the connection area (54) transversely to the subdivision area (60). [4] Electric power tool (1) according to any one of claims 1 to 3, wherein the subdivision area (60) has a curved area (61) which is bent to one side of the conductor wire (42) for an electrical component, and The cover (23), the subdivision area (60) and the curved area (61) form a wiring path (62) of the conductor wire (42) for an electrical component. [5] Electric power tool (1) according to any one of claims 1 to 4, wherein an outer housing (53) which partially covers the cover (23), is arranged on a lower side of the cover (23), and the connection area (54) and the subdivision area (60) are arranged between the cover (23) and the outer casing (53). [6] Electric power tool (1) according to one of claims 1 to 5, wherein the subdivision area (60) is integrally formed with the cover (23). [7] Electric power tool (1) according to any one of claims 1 to 6, wherein the connection area is a screw fastening area (54), and the subdivision area (60) is positioned in a withdrawal direction of a screw (58) with which the earthing wire (56) is installed on the screw fastening area (54), and is close to or in contact with the screw (58). [8] Electric power tool (1) according to any one of claims 1 to 7, wherein the electrical part (8) is a light (38) for illumination. [9] Electric power tool (1) according to any one of claims 1 to 8, wherein the output unit is a hammer unit (6) that applies intermittent hammering in a rotational direction to an anvil (7) that projects forward, the housing is a hammer housing (22) which supports the anvil (7), and the cover is a hammer housing cover (23) that covers an outside of the hammer housing (22). [10] Electric tool (1) according to claim 1, wherein the connection area is a screw fastening area (54), the screw fastening area (54) is formed on a lower surface of the housing (22) and protrudes downwards through the cover (23), the subdivision area (60) extends in a front-back direction in a lower surface of the cover (23) and subdivides between the screw fastening area (54) and the conductor wire (42) for an electrical component, and the subdivision area (60) is positioned in a removal direction of the screw (58) with which the grounding wire (56) is installed on the screw fastening area (54), and is close to or in contact with a head of the screw (58), and a bent area (61) which is bent to one side of the conductor wire (42) for an electrical component is formed at a lower end of the subdivision area (60), and a wiring path (62) of the conductor wire (42) for an electrical component through the cover (23), the subdivision area (60) and the bent area (61) is formed linearly in a left-right direction in an overlapping state with the screw fastening area (54) and the grounding wire (56).

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