Power tool

Abstract

A gearbox housing has a cylindrical section with a through-hole and mounting brackets provided on the outer circumference of the cylindrical section. A motor mount is fixed to the mounting brackets by screws. A shift actuator causes a speed reduction mechanism to change the gear ratio by moving it. A shift wire passes through the through-hole and couples the shift actuator to the speed reduction mechanism. The shift wire has a first wire segment extending from the shift actuator to the cylindrical section, a second wire segment extending along an outer circumferential surface of the cylindrical section from one end of the first wire segment, and a third wire segment extending from one end of the second wire segment and inserted into the through-hole.The mounting components are arranged in positions other than a first area opposite the second wire segment.

Description

TECHNICAL AREA The techniques revealed in these teachings relate to a power tool. BACKGROUND A screwdriver with a gear-shifting function, as disclosed in Japanese patent application JP 2023-89934A, is known in the field of power tools. The reduction ratio of a speed reduction mechanism is changed by moving a speed-changing lever to a position for a low-speed mode, a position for a medium-speed mode, or a position for a high-speed mode. Japanese patent application JP 2023-89934A discloses that a speed-changing lever is coupled via a shift wire to an internal gear used for gear shifting, and the internal gear is located in a gear-shifting position corresponding to the position of the speed-changing lever via the shift wire. In a state where the speed-changing lever is positioned in any speed mode, the internal gear is held in the gear-shifting position by the shift wire. For reliable speed-shifting, it is desirable to prevent positional displacement of a movable component (internal gear) for gear shifting caused by a reaction force from another gear, vibration during power tool movement, or similar phenomena. A non-limiting objective of the present teachings is to achieve reliable gear shifting. BRIEF SUMMARY The above-mentioned problem is solved by a power tool according to claim 1 or claim 11. In one aspect of the present teachings, a power tool may comprise a motor, an output part, a speed reduction mechanism, a gearbox housing, a motor mount, a switching actuation part, and a switching wire. The output part may be located at the front of the motor and configured to be driven by the motor. The speed reduction mechanism may be located between the motor and the output part and may include a gear-shifting function. The gearbox housing may comprise a cylindrical part having at least one through-hole extending radially through it, and a plurality of mounting attachments provided on an outer circumference of the cylindrical part, and may accommodate the speed reduction mechanism within the cylindrical part.The motor mount can be positioned between the motor and the speed reduction mechanism and can be fixed to the mounting brackets by screws. The shift actuator can be configured to cause the speed reduction mechanism to change the gear selection by moving it. The shift wire can pass through the through-hole in the gearbox housing and can couple the shift actuator to the speed reduction mechanism. The shift wire can have at least one wire section comprising a first to third wire segment. The first wire segment can extend from the shift actuator to the cylindrical part when viewed axially. The second wire segment can extend circumferentially along an outer circumferential surface of the cylindrical part from one end of the first wire segment.The third wire segment can extend from one end of the second wire segment and can be inserted into the through-hole. The mounting elements are provided at positions other than a first area opposite the second wire segment in the radial direction on the outer circumferential surface of the cylindrical part. In another aspect of the present teachings, a power tool may comprise a motor, an output part located at the front of the motor and configured to be driven by the motor, a speed reduction mechanism located between the motor and the output part and having a gear-shifting function, a gear housing having a cylindrical part having at least one through-hole penetrating it in a radial direction and accommodating the speed reduction mechanism inside the cylindrical part, a motor mount located between the motor and the speed reduction mechanism and fixing the gear housing by screws, a shift actuating part configured to cause the speed reduction mechanism to change the gear shift by being moved, and a shift wire.which passes through the through-hole of the gearbox housing and couples the shift actuator to the speed reduction mechanism. The shift wire may have a retained section that is held by the shift actuator. The gearbox housing may have a first screw fixing element, which is provided in a position opposite the retained section of the shift wire in the radial direction when viewed in the axial direction, and which fixes the motor mount. Reliable gear shifting is achieved according to the techniques revealed in the present teachings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front perspective view showing a power tool according to one embodiment; Fig. 2 is a rear perspective view showing the power tool according to the embodiment; Fig. 3 is a side view showing the power tool according to the embodiment; Fig. 4 is a cross-sectional view showing the power tool according to the embodiment; Fig. 5 is a cross-sectional view showing part of the power tool according to the embodiment; Fig. 6 is a front right perspective view showing part of a speed reduction mechanism according to the embodiment; Fig. 7 is a front perspective view showing part of the power tool according to the embodiment; Fig. 8 is a side view showing part of the power tool according to the embodiment; Fig.Figure 9 is a cross-sectional view showing part of the power tool according to the embodiment; Figure 10 is a front perspective exploded view showing the speed reduction mechanism according to the embodiment; Figure 11 is a rear perspective view showing part of the speed reduction mechanism according to the embodiment; Figure 12 is a side view showing a speed change mechanism according to the embodiment; Figure 13 is a bottom right rear perspective view showing the speed change mechanism according to the embodiment; Figure 14 shows the power tool in a case where the speed reduction mechanism according to the embodiment is fixed in a low-speed mode when viewed from above; FigureFigure 15 is a cross-sectional view showing the speed reduction mechanism in a case where the speed reduction mechanism is set to the low-speed mode according to the embodiment; Figure 16 shows the power tool in a case where the speed reduction mechanism is set to a high-speed mode according to the embodiment, when viewed from above; Figure 17 is a cross-sectional view showing the speed reduction mechanism in a case where the speed reduction mechanism is set to the high-speed mode according to the embodiment; Figure 18 is a horizontal cross-sectional view from above of a point of engagement between a speed-changing lever and a housing; Figure 19 is a perspective view from the rear showing a gearbox housing, a motor mount, and a gearbox housing according to the embodiment; FigureFigure 20 is a rear-view perspective exploded view showing the gearbox housing, motor mount, and gearbox enclosure according to the embodiment; Figure 21 is a bottom-view perspective view showing the speed-changing lever and a switching wire according to the embodiment; Figure 22 is a rear-view perspective view showing the gearbox housing and the switching wire according to the embodiment; Figure 23 is an axial rear-view arrow view of the gearbox housing and the switching wire according to the embodiment; Figure 24 is an enlarged view of the area surrounding the first wire segment and the second wire segment of the switching wire in Figure 23; Figure 25 is an axial rear-view cross-sectional arrow view of a plane passing through the second wire segments of the switching wire; FigureFigure 26 is an explanatory perspective view showing the mating surfaces of the gearbox housing and the motor mount; and Figure 27 is an arrow view of a front surface of the motor mount seen in the axial direction from the front. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS In one or more embodiments, a power tool may comprise a motor, an output part, a speed reduction mechanism, a gearbox housing, a motor mount, a switching actuation part, and a switching wire. The output part may be located at the front of the motor and configured to be driven by the motor. The speed reduction mechanism may be located between the motor and the output part and may include a gear-shifting function. The gearbox housing may comprise a cylindrical part having at least one through-hole extending radially through it, and a plurality of mounting elements provided on an outer circumference of the cylindrical part, and may accommodate the speed reduction mechanism within the cylindrical part.The motor mount can be positioned between the motor and the speed reduction mechanism and can be fixed to the mounting brackets by screws. The shift actuator can be configured to cause the speed reduction mechanism to change the gear ratio when moved. The shift wire can pass through the through-hole in the gearbox housing and can couple the shift actuator to the speed reduction mechanism. The shift wire can have at least one wire section comprising a first to third wire segment. The first wire segment can extend from the shift actuator to the cylindrical part when viewed axially. The second wire segment can extend circumferentially along an outer circumferential surface of the cylindrical part from one end of the first wire segment.The third wire segment can extend from one end of the second wire segment and can be inserted into the through-hole. The mounting elements are located on the outer circumference of the cylindrical part in positions other than a first area that is radially opposite the second wire segment. In the configuration described above, the mounting brackets of the gearbox housing are located in different positions on the outer circumference of the cylindrical part than the first area, which is radially opposite the second wire segment. When the mounting brackets are located in the first area, the second wire segment of the switching wire wraps around the outside of the mounting bracket. In contrast, in the present configuration, the second wire segment of the switching wire connects the first wire segment to the third wire segment without wrapping around the outside of the mounting bracket. This can shorten the path length of the switching wire, resulting in the speed reduction mechanism and thus increasing the spring constant (stiffness) of the switching wire.Increasing the spring constant of the shift wire makes it less flexible and allows a gear coupled via the shift wire to be supported even when a reaction force acts on the gear. Consequently, positional displacement of a gear used for shifting the speed reduction mechanism is less likely, resulting in more reliable gear shifting. In one or more embodiments, the at least one through-hole can have two through-holes provided on one side and the other side in a lateral direction of the gearbox housing. The at least one wire section can have a first wire section provided on one side and inserted into the through-hole provided on that side, and a second wire section provided on the other side and inserted into the through-hole provided on that side. The mounting elements can have a first projection arranged between the first wire segment of the first wire section and the first wire segment of the second wire section. In the configuration described above, the first mounting bracket can be positioned by utilizing the space between the first and second wire sections. This ensures installation space for the mounting bracket (first section) without increasing the dimensions of the gearbox housing and motor mount, while simultaneously reducing the switching wire length. In one or more embodiments, the switching actuation element can be arranged on top of the gearbox housing. The mounting elements can have at least a second projection located in the second area below the through-holes on the outer circumference of the cylindrical part. In the configuration described above, by positioning the second attachment point in the second area, located below the through-holes where the shift wire is not inside the gearbox housing, the number of fixing points for the motor mount can be increased without rerouting the shift wire. The gearbox housing and motor mount can be securely fixed together by the first and second attachment points. This prevents leakage of lubricants (grease) and the like. In one or more embodiments, the at least one second projection can have two second projections arranged on one side and the other side in the lateral direction of the cylindrical part in the second area. In the configuration described above, by arranging several (at least two) secondary supports in the second area where the switching wire is not positioned, multiple (at least two) fixing points for the motor mount on the gearbox housing can be distributed over a wider circumference. Consequently, the first support and the multiple secondary supports can fix the motor mount more evenly. Again, in this case, the switching wire does not need to run around the outside of the supports, which can improve the reliability of the gearbox shifting. In one or more embodiments, a radial distance between the second wire segment of the switching wire and an outer circumferential surface of the cylindrical part in the first area can be smaller than a protrusion of the mounting attachment part with respect to the outer circumferential surface in the first area. In the configuration described above, the second wire segment of the shift wire is arranged radially inside the outer circumferential area of ​​the mounting bracket, and the distance between the second wire segment and the outer circumferential surface of the cylindrical part of the gearbox housing is sufficiently reduced. This effectively shortens the path length of the second wire segment. Therefore, the spring constant of the shift wire can be effectively increased, further improving its performance in holding the gear in position for gear shifting. In one or more embodiments, the power tool may further comprise a gearbox housing provided at the front of the gearbox housing, to which a front end of the gearbox housing is fixed. The gearbox housing may have a plurality of housing attachment parts arranged radially outside the switching wire and fixed to the gearbox housing by screws. In the configuration described above, the gearbox housing can be fixed to the gearbox enclosure by the multiple enclosure attachments, which are separate from the mounting attachments. In this case, the majority of the enclosure attachments are also arranged radially outside the switching wire. Therefore, the switching wire does not need to run around the outside of the enclosure attachments, and an increase in the switching wire's path length can be avoided. In one or more embodiments, the enclosure attachment parts can have at least a third attachment which is arranged radially outside the second wire segment of the switching wire in the first area. In the configuration described above, space for the enclosure attachments (third attachment) can be ensured in the first area where the mounting attachments are not located, without rerouting the second wire segment of the switching wire. In one or more embodiments, the third projection can have a cutout area on an outer circumferential region of the same, which points towards the radial center of the cylindrical part, in order to prevent the switching wire from coming into contact with the third projection. In the configuration described above, the cutout area is provided on the third projection, which is located radially outside the second wire segment of the switching wire. This allows the radial position of the third projection to be brought closer to the second wire segment. This can prevent an increase in the dimensions of the outer shape of the gearbox housing, even in a configuration where the third projection is located outside the second wire segment of the switching wire. In one or more embodiments, the at least one through-hole can have two through-holes arranged on one side and another side in a lateral direction of the gearbox housing. The at least one wire section can have a first wire section arranged on one side and inserted into the through-hole provided on that side, and a second wire section arranged on the other side and inserted into the through-hole provided on that side. The at least one third projection can have two third projections arranged on the outside of the second wire segment of the first wire section and on the outside of the second wire segment of the second wire section. In the configuration described above, the third attachment points are located on the outside of the second wire segment of the first wire section and on the outside of the second wire segment of the second wire section. This allows the fixing points for the gearbox housing and the gearbox enclosure to be distributed over a wider area, resulting in more even fixing of the gearbox housing. In one or more embodiments, the shift actuation element can be arranged on top of the gearbox housing. The housing extension parts can have a fourth extension located in the second area, which is situated below the through-hole on the outer circumference of the cylindrical part. In the configuration described above, by placing the fourth attachment point in the second area, where the switching wire is not positioned inside the gearbox housing, a greater number of fixing points for the gearbox housing can be distributed over a wider circumference. Consequently, the third and fourth attachment points can fix the gearbox housing more evenly. In one or more embodiments, the power tool may include a motor, an output part, a speed reduction mechanism, a gearbox housing, a motor mount, a switching actuator, and a switching wire. The output part may be located at the front of the motor and configured to be driven by the motor. The speed reduction mechanism may be located between the motor and the output part and may include a gear-shifting function. The gearbox housing may have a cylindrical portion with at least one through-hole extending radially through it and may accommodate the speed reduction mechanism within the cylindrical portion. The motor mount may be located between the motor and the speed reduction mechanism and may be bolted to the gearbox housing.The shift actuator can be configured such that, by moving it, it causes the speed reduction mechanism to change the gear selection. The shift wire can pass through the through-hole in the gearbox housing and can couple the shift actuator to the speed reduction mechanism. The shift wire can have a retained section that is held by the shift actuator. The gearbox housing can have a first screw fixing element, which is provided in a position opposite the retained section of the shift wire in the radial direction when viewed in the axial direction, and can fix the motor mount. In the configuration described above, the first screw fixing element for securing the motor mount is located in the gearbox housing opposite the held section of the switching wire in the radial direction when viewed in the axial direction. If the first screw fixing element is positioned midway along the path to the speed reduction mechanism, the switching wire runs around the outside of the first screw fixing element. In contrast, in the configuration with a coupling area, the switching wire can be connected to the speed reduction mechanism without running from the held section around the outside of the first screw fixing element. This can shorten the path length of the switching wire leading to the speed reduction mechanism, thereby increasing the spring constant (stiffness) of the switching wire.Increasing the spring constant of the switching wire makes it less flexible and allows a gear coupled to the switching wire to be supported even when a reaction force acts on the gears. Consequently, positional displacement of the gear for the speed reduction mechanism is less likely, resulting in reliable gear shifting. In one or more embodiments, the first screw fixing element in the gearbox housing can be provided at a location in a region opposite the switching wire in the radial direction when viewed in the axial direction. In the gearbox housing, a plurality of second screw fixing elements, which secure the motor mount, can be provided in a region that is not opposite the switching wire in the radial direction when viewed in the axial direction. In the configuration described above, only one primary screw fixing element is provided in the opposite area, thus eliminating the need for the switching wire to route around the screw fixing elements. The majority of secondary screw fixing elements are located in the non-opposite area, allowing the motor mount and gearbox housing to be evenly fixed to each other at multiple points, while preventing any increase in the switching wire's travel length. In one or more embodiments, the gearbox housing and the motor mount can be fixed to each other at three points arranged in a triangular shape when viewed in the axial direction, by arranging a first screw fixing part in the opposite area, and two second screw fixing parts on one side and another side in the lateral direction with respect to the center of the gearbox housing in the non-opposite area. In the configuration described above, by fixing the motor mount and gearbox housing at three points arranged in a triangular shape when viewed in the axial direction, the motor mount and gearbox housing can be fixed evenly and firmly to each other, while avoiding elongation in the path length of the switching wire. In one or more embodiments, the gearbox housing can have a first mating surface, having an annular flat shape, on a rear surface opposite the motor mount. The motor mount can have a second mating surface, also having an annular flat shape and in contact with the first mating surface, on a front surface opposite the gearbox housing. In the configuration described above, the first mating surface of the gearbox housing and the second mating surface of the motor mount, both of which have a flat surface, can be brought into surface contact with each other. This can effectively prevent lubricant (grease) leakage inside the gearbox housing, even when vibration is generated by driving the motor. In one or more embodiments, the power tool may further comprise a gearbox housing provided at the front of the gearbox housing, to which a front end of the gearbox housing is fixed. The gearbox housing may have two third screw fixing elements, arranged at one position in the circumferential direction between the first screw fixing element and the second screw fixing element located on one side, and at another position in the circumferential direction between the first screw fixing element and the second screw fixing element located on the other side. In the configuration described above, the screw tightening points (third screw fixing parts), where the gearbox housing and gearbox enclosure are screwed together, can be positioned circumferentially relative to the screw tightening points (first screw fixing part and second screw fixing parts), where the gearbox housing and motor mount are screwed together. This can improve the machinability of screw tightening operations. In one or more embodiments, the gearbox housing may have a fourth screw fixing element arranged between the two second screw fixing elements located on one side and the other side in the non-opposite region. The gearbox housing and the gearbox enclosure may be fixed to one another at three points, arranged in an inverted triangular shape when viewed axially, by the two third screw fixing elements and the fourth screw fixing element. In the configuration described above, the motor mount and gearbox housing are fixed to each other at three points arranged in a triangular shape when viewed axially. The gearbox housing and gearbox enclosure are fixed to each other at three points arranged in an inverted triangular shape when viewed axially. This allows for a uniform fixing of the motor mount to the gearbox housing and the fixing of the gearbox housing to the gearbox enclosure, and improves the ease of tightening screws at each fixing point. One embodiment according to the present disclosure is described below with reference to the drawings; however, the present disclosure is not limited to this embodiment. Components of the embodiment described below can be suitably combined. Furthermore, some components are not used in certain cases. In this embodiment, positional relationships among the parts are described using the terms left, right, front, back, top, and bottom. These terms indicate a relative position or direction with respect to the center of a power tool. The power tool includes a motor. In this embodiment, the direction parallel to the motor's axis of rotation AX is appropriately referred to as the axial direction. The direction around the axis of rotation AX is appropriately referred to as the circumferential direction and the direction of rotation. The radial direction of the axis of rotation AX is appropriately referred to as the radial direction. In this embodiment, the axis of rotation AX extends in a front-back direction of the power tool. The axial direction and the front-back direction coincide (are collinear) or are parallel to each other. One side in the axial direction faces forward, and the other side faces backward. Furthermore, in the radial direction, a location close to or a direction approaching the axis of rotation AX is designated "radially inward," where appropriate, and a location farther from or a direction away from the axis of rotation AX is designated "radially outward," where appropriate. Overview of power tools Fig. 1 is a front perspective view showing the power tool 1 according to the embodiment. Fig. 2 is a rear perspective view showing the power tool 1 according to the embodiment. Fig. 3 is a side view showing the power tool 1 according to the embodiment. Fig. 4 is a cross-sectional view showing the power tool 1 according to the embodiment. In this embodiment, the power tool 1 is an impact drill. As shown in Figs. 1, 2, 3 to 4, the power tool 1 comprises a housing 2, a rear cover 3, a casing 4, a battery mounting part 5, a motor 6, a power transmission mechanism 7, an output part 8, a fan wheel 9, a push lever 10, a forward-reverse rotary shift lever 11, a speed change lever 12, a mode change ring 13, a light 14, and a control 17. The speed change lever 12 is an example of a switching actuation part. The housing 2 is made of synthetic resin. In this embodiment, the housing 2 is preferably made of nylon. The housing 2 has a left housing 2L and a right housing 2R. The left housing 2L and the right housing 2R are fixed by screws 2S. The left housing 2L and the right housing 2R are fixed together to form the housing 2. The housing 2 has a motor housing part 21, a handle part 22 and a battery holding part 23. The motor housing part 21 accommodates the motor 6. The motor housing part 21 has a tubular shape. The motor housing part 21 is arranged such that it covers the circumference of the motor 6. The handle part 22 is gripped by a user. The handle part 22 is positioned downwards from the motor housing part 21. The handle part 22 extends downwards from the motor housing part 21. The push-button lever 10 is located on a front portion of the handle part 22. The battery holder 23 accommodates the control unit 17. The battery holder 23 is located on a lower portion of the handle 22. The battery holder 23 is connected to a lower end portion of the handle 22. In both the front-back and left-right directions, the battery holder 23 has an outer dimension that is larger than that of the handle 22. The rear cover 3 is made of a synthetic resin. The rear cover 3 is located at the rear of the motor housing part 21. The rear cover 3 is positioned to cover the rear section of the motor 6. The rear cover 3 accommodates the fan wheel 9. The rear cover 3 is positioned to cover an opening in a rear section of the motor housing part 21. The rear cover 3 is fixed to the motor housing part 21 by screws 3S. The motor housing part 21 has air intake openings 18. The rear cover 3 has air outlet openings 19. Air on the outside of the housing 2 flows into the interior of the housing 2 through the air intake openings 18. Air in the interior of the housing 2 flows to the outside of the housing 2 through the air outlet openings 19. The housing 4 accommodates the power transmission mechanism 7. The housing 4 comprises a gearbox housing 4A, a gearbox enclosure 4B, a motor mount 4C, and a stop plate 4D. The gearbox enclosure 4B is located at the front of the gearbox housing 4A. The mode-changing ring 13 is located at the front of the gearbox enclosure 4B. The gearbox housing 4A is made of a synthetic resin. The gearbox enclosure 4B is made of metal. In this embodiment, the gearbox enclosure 4B is made of aluminum. The housing 4 is connected to a front portion of the motor housing part 21. Both the gearbox housing 4A and the gearbox enclosure 4B are tubular in shape. A front end of the gearbox housing 4A is fixed to the gearbox enclosure 4B. The gearbox housing 4A is fixed to a rear end of the gearbox enclosure 4B. The motor mount 4C is made of a synthetic resin. The motor mount 4C is positioned to cover an opening at a rear end of the gearbox housing 4A. The motor mount 4C is fixed to the rear end of the gearbox housing 4A. The stop plate 4D is positioned to cover an opening at a front end of the gearbox enclosure 4B. The stop plate 4D is fixed to the front end of the gearbox enclosure 4B by screws 4F (see Fig. 5). The housing 4 is arranged such that it covers an opening in the front area of ​​the motor housing part 21. The gearbox housing 4A is located inside the motor housing part 21. The gearbox enclosure 4B is fixed to the motor housing part 21 by screws 4S. The battery mounting part 5 is formed on a lower region of the battery holder 23. The battery mounting part 5 is connected to a battery pack 20. The battery pack 20 is mounted on the battery mounting part 5. The battery pack 20 is removable from the battery mounting part 5. The battery pack 20 has a secondary battery (rechargeable battery). In this embodiment, the battery pack 20 has a rechargeable lithium-ion battery. When mounted on the battery mounting part 5, the battery pack 20 can supply power to the power tool 1. The motor 6 is driven by the electrical power supplied by the battery pack 20. The control unit 17 operates using electrical power supplied by the battery pack 20. The motor 6 is a power source for the power tool 1. The motor 6 is an internal rotor brushless motor. The motor 6 is housed in the motor casing part 21. The motor 6 has a tubular stator 61 and a rotor 62 located inside the stator 61. The rotor 62 rotates relative to the stator 61. The rotor 62 has a rotor shaft 63 extending in the axial direction. The power transmission mechanism 7 is located at the front of the motor 6. The power transmission mechanism 7 is housed within the casing 4. The power transmission mechanism 7 operatively couples the rotor shaft 63 and the output part 8. The power transmission mechanism 7 transmits power generated by the motor 6 to the output part 8. The power transmission mechanism 7 comprises a plurality of gears. The power transmission mechanism 7 has a speed reduction mechanism 30 and a hammer mechanism 40. The speed reduction mechanism 30 is located between the motor 6 and the output part 8. The speed reduction mechanism 30 is driven by the rotor 62 (the rotor shaft 63) and causes the output part 8 to rotate at a lower speed than the rotor 62 (but with higher torque). The speed reduction mechanism 30 can shift gears (i.e., it can change the speed reduction ratio). The speed reduction mechanism 30 has a gear mechanism connected to the speed-changing lever 12. The reduction ratio of the speed reduction mechanism 30 is switched by changing the position of a gear in the gear mechanism according to the speed-changing position of the speed-changing lever 12.In this embodiment, the speed reduction mechanism 30 comprises a first (first-stage) planetary gear mechanism 31, a second (two-stage) planetary gear mechanism 32, and a third (third-stage) planetary gear mechanism 33. At least one section of the first planetary gear mechanism 31 is located at the front of the motor 6. The second planetary gear mechanism 32 is located at the front of the first planetary gear mechanism 31. The third planetary gear mechanism 33 is located at the front of the second planetary gear mechanism 32. The first planetary gear mechanism 31 is driven (operated) by a rotational force output by the motor 6 via the rotor shaft 63. The second planetary gear mechanism 32 is driven (operated) by a rotational force output by the first planetary gear mechanism 31.The third planetary gear mechanism 33 is driven (operated) by a rotational force output by the second planetary gear mechanism 32. When activated, the hammer mechanism 40 causes the output part 8 to hammer in the axial direction. The hammer mechanism 40 has a first cam 41, a second cam 42, and a hammer switching ring 43. The output part 8 is located at the front of the motor 6. The output part 8 is rotated using the torque output by the motor 6. That is, the output part 8 is rotated using the torque output by the rotor 62. Specifically, when a tool accessory is attached to it, the output part 8 is rotated by the torque output by the rotor 62, which is transmitted via the power transmission mechanism 7. The output part 8 has a spindle 81 and a drill chuck 82. The spindle 81 is rotatable about the axis of rotation AX by the torque output by the rotor 62. The drill chuck 82 is attached to the spindle 81 and configured to hold a tool accessory. That is, the tool accessory is held by the drill chuck 82. A front end of the drill chuck 82 is located at the front of the housing 4.At least one section of the spindle 81 is located at the front of the third planetary gear mechanism 33. The spindle 81 is operationally coupled to the third planetary gear mechanism 33. The spindle 81 is rotated by the torque output by the rotor 62, which is transmitted via the first planetary gear mechanism 31, the second planetary gear mechanism 32, and the third planetary gear mechanism 33. The fan wheel 9 is located at the rear of the motor 6. The fan wheel 9 generates an airflow to cool the motor 6. The fan wheel 9 is fixed to at least one section of the rotor 62. Specifically, the fan wheel 9 is fixed to a rear section of the rotor shaft 63. The fan wheel 9 is rotated by the rotation of the rotor shaft 63. That is, the rotor shaft 63 rotates, and the fan wheel 9 rotates together with the rotor shaft 63. When the fan wheel 9 rotates, air flows from the outside of the housing 2 through the air intake openings 18 into the interior of the housing 2. The air that has flowed into the interior of the housing 2 flows through the interior of the housing 2, thereby cooling the motor 6. The air that has flowed through the interior of the housing 2 flows to the outside of the housing 2 through the air outlet openings 19. The trigger lever 10 is actuated to start the motor 6. The trigger lever 10 is located on an upper part of the handle 22. A front end of the trigger lever 10 projects forward from a front part of the handle 22. The trigger lever 10 is movable in a forward-backward direction. The trigger lever 10 is configured to be actuated by the user. By actuating (pushing) the trigger lever 10 so that it moves backward, the motor 6 starts. By releasing the trigger lever 10, the motor 6 stops. The forward / reverse rotary shift lever 11 is actuated (moved) to change the direction of rotation of the motor 6. The forward / reverse rotary shift lever 11 is located on an upper portion of the handle 22. A left end of the forward / reverse rotary shift lever 11 projects to the left of a left portion of the handle 22. A right end of the forward / reverse rotary shift lever 11 projects to the right of a right portion of the handle 22. The forward / reverse rotary shift lever 11 is movable in the left-right direction. The forward / reverse rotary shift lever 11 is configured to be operated by the user. By actuating (moving) the forward-reverse rotary shift lever 11 so that it moves to the left, the motor 6 rotates in a forward direction.By actuating (moving) the forward / reverse rotation selector lever 11 so that it moves to the right, the motor 6 rotates in a reverse direction. Changing the direction of rotation of the motor 6 changes the direction of rotation of the spindle 81. The speed-changing lever 12 is a shift-actuating component configured to change (shift) the speed mode (gearbox gear) of the speed reduction mechanism 30. The speed-changing lever 12 is located on an upper portion of the motor housing part 21. The speed-changing lever 12 extends upwards from the housing 4. The speed-changing lever 12 is configured to cause the speed reduction mechanism 30 to change its gear selection (i.e., change the speed mode or a gear ratio of the speed-changing lever 12). The speed-changing lever 12 is actuated (moved, shifted) by the user. The speed-changing lever 12 is movable in the forward-backward direction. The speed modes of the speed reduction mechanism 30 include a low-speed mode (speed "1") and a high-speed mode (speed "2").This means that, in this embodiment, the speed reduction mechanism 30 can change a gear ratio in two stages. The low-speed mode refers to a speed mode in which the output part 8 is caused to rotate at a first speed (low speed) while the rotor 62 rotates at a constant speed. The high-speed mode refers to a speed mode in which the output part 8 is caused to rotate at a second speed (high speed) that is higher than the first speed, while the rotor 62 rotates at the same constant speed. The mode-change ring 13 is configured to be actuated (rotated) to change the operating mode of the hammer mechanism 40. The mode-change ring 13 is located on the front of the housing 4. The mode-change ring 13 is rotatable. Specifically, the mode-change ring 13 is configured to be actuated (manually rotated) by the user. The operating modes of the hammer mechanism 40 include a hammer mode and a non-hammer mode. The hammer mode refers to an operating mode in which the output part 8 is caused to hammer in the axial direction. The non-hammer mode refers to an operating mode in which the output part 8 is not caused to hammer in the axial direction. By actuating (rotating) the mode-change ring 13 so that it is positioned in a hammer mode position in the direction of rotation, the operating mode of the hammer mechanism 40 is set to the hammer mode.By actuating (rotating) the mode change ring 13 so that it is positioned in the non-hammer mode position in the direction of rotation, the operating mode of the hammer mechanism 40 is set to the non-hammer mechanism. Light 14 emits a light that illuminates the front of the power tool 1. Light 14 includes, for example, a light-emitting diode (LED). Light 14 is located in a lower area of ​​the front of the motor housing part 21. Light 14 is located above the trigger lever 10. The controller 17 comprises a computer system. The controller 17 issues control commands for controlling the motor 6. At least one part of the controller 17 is enclosed in a controller housing 26. The controller 17 is enclosed in the battery holder 23, with the controller 17 being held by the control housing 26. The controller 17 preferably comprises a circuit board on which a plurality of electronic components are mounted. Examples of the electronic components mounted on the circuit board include a processor, such as a central processing unit (CPU), non-volatile memory, such as read-only memory (ROM) or a storage device, volatile memory, such as random-access memory (RAM), a transistor, a capacitor, and a resistor. Motor and power transmission mechanism Fig. 5 is a cross-sectional view showing part of the power tool 1 according to the embodiment. As shown in Fig. 5, the motor 6 has the stator 61, which is tubular, and the rotor 62, which is arranged inside the stator 61. The rotor 62 has the rotor shaft 63, which extends in the axial direction. The stator 61 comprises a stator core 61A, a front insulating piece 61B, a rear insulating piece 61C, a plurality of coils 61D, a sensor circuit board 61E, and a short-circuiting device 61F. The stator core 61A comprises a plurality of stacked (laminated) steel disks. The front insulating piece 61B is located at a front region of the stator core 61A. The rear insulating piece 61C is located at a rear end region of the stator core 61A. The coils 61D are each wound around teeth located on an inner surface of the stator core 61A and over the front insulating piece 61B and the rear insulating piece 61C. The sensor circuit board 61E is mounted to the front insulating piece 61B. The short-circuiting device 61F is mounted to the front insulating piece 61B. The sensor circuit board 61E has a plurality of rotation detection elements that detect a rotation of the rotor 62.The short-circuiting device 61F connects respective pairs of coils 61D via fuse terminals. The short-circuiting device 61F is electrically connected to the control unit 17 via connecting wires. The rotor 62 rotates about an axis of rotation AX. The rotor 62 has a rotor shaft 63, a rotor core 62A, and a plurality of permanent magnets 62B. The rotor core 62A is arranged around the rotor shaft 63. The permanent magnets 62B are held on or in the rotor core 62A. The rotor core 62A has a circular tube shape. The rotor core 62A has a plurality of stacked (laminated) steel disks. The rotor core 62A has through holes extending in the axial direction. The through holes are arranged in (around) the circumferential direction of the rotor core 62A. The permanent magnets 62B are each arranged in the through holes of the rotor core 62A. The rotation detection elements of the sensor circuit board 61E detect a rotation (rotational position) of the rotor 62 by detecting the magnetic fields of the permanent magnets 62B. The controller 17 supplies drive currents to the respective coils 61D based on detection data from the rotation detection elements. The rotor shaft 63 rotates about the axis of rotation AX. The axis of rotation AX of the rotor shaft 63 coincides with the axis of rotation of the output part 8. A front section of the rotor shaft 63 is rotatably supported by a bearing 64. A rear section of the rotor shaft 63 is rotatably supported by a bearing 65. The bearing 64 is held by the motor mount 4C, which is located at the front of the stator 61. The motor mount 4C supports the front section of the rotor shaft 63 via the bearing 64. The bearing 65 is held by the rear cover 3. A front end section of the rotor shaft 63 is located at the front of the bearing 64. The front end section of the rotor shaft 63 passes through the motor mount 4C and is located inside (extends within) the gearbox housing 4A. The motor mount 4C is located between the motor 6 and the speed reduction mechanism 30. A drive gear 31S is provided at (on) the front end of the rotor shaft 63. The drive gear 31S functions as a sun gear of the first planetary gear mechanism 31. The drive gear 31S is rotated by the motor 6. The rotor shaft 63 is coupled to the first planetary gear mechanism 31 of the speed reduction mechanism 30 via the drive gear 61S. Fig. 6 is a perspective view showing part of the speed reduction mechanism 30 according to the embodiment, viewed from the front right. The spindle 81 is coupled to a third support 33C. In this embodiment, an engagement element 34 is provided on an outer circumferential surface of the spindle 81. The engagement element 34 is fixed to the spindle 81. The engagement element 34 has projections 34A that extend in opposite directions from an outer circumferential region of the engagement element 34. The third support 33C is arranged around the spindle 81. Engagement projections 35 are provided on the front surface of the third support 33C. The engagement projections 35 extend forward. The engagement projections 35 come into contact with the projections 34A of the engagement element 34 in the circumferential direction.A relative rotation between the third support 33C and the spindle 81 is blocked by the contact between the engagement projections 35 and the projections 34A of the engagement component 34. Thus, when the third support 33C rotates, the spindle 81 rotates together with the third support 33C. The spindle 81 is rotatably mounted by a bearing 83 and a bearing 84. In the state in which the spindle 81 is mounted by the bearing 83 and the bearing 84, the spindle 81 is movable in the forward-backward direction. As shown in Fig. 5, the spindle 81 has a flange region 81F. A helical spring 87 is arranged between the flange region 81F and the bearing 83. The flange region 81F comes into contact with a front end region of the helical spring 87. The helical spring 87 generates an elastic force that pushes (preloads) the spindle 81 forward. The drill chuck 82 is configured to hold the tool accessory. The drill chuck 82 is coupled to a front portion of the spindle 81. A screw hole 81R is provided at a front end portion of the spindle 81. When the spindle 81 rotates, the drill chuck 82 rotates with it. The drill chuck 82 is rotatable in the position in which it holds the tool accessory. The first cam 41 and the second cam 42 of the hammer mechanism 40 are both located inside the gearbox housing 4B. In the front-back direction, both the first cam 41 and the second cam 42 are located between the bearing 83 and the bearing 84. The first cam 41 has a ring shape. The first cam 41 is arranged around the spindle 81. The first cam 41 is fixed to the spindle 81. The first cam 41 rotates together with the spindle 81. Cam teeth are provided on the rear surface of the first cam 41. The first cam 41 is supported by a stop ring 44. The stop ring 44 is arranged around the spindle 81. The stop ring 44 is located between the first cam 41 and the bearing 83 in the front-back direction. The second cam 42 also has a ring shape. The second cam 42 is located in front of the first cam 41. The second cam 42 is arranged around the spindle 81. The second cam 42 is rotatable relative to the spindle 81. Cam teeth are provided on the front surface of the second cam 42. The cam teeth on the front surface of the second cam 42 mesh with the cam teeth on the rear surface of the first cam 41. A tab is provided on the rear surface of the second cam 42. A bearing ring 45 is arranged between the second cam 42 and the bearing 84 in the front-back direction. The bearing ring 45 is located inside the gearbox housing 4B. The bearing ring 45 is fixed to the gearbox housing 4B. A plurality of steel balls 46 are arranged on the front surface of the bearing ring 45. A washer 47 is arranged between the steel balls 46 and the second cam 42. The second cam 42 is rotatable in the state in which its forward-backward movement is restricted to a space defined by the bearing ring 45 and the washer 47. The hammer shift ring 43 can be switched from hammer mode to non-hammer mode and vice versa by manually rotating it. The mode-changing ring 13 is coupled to the hammer shift ring 43 via a cam ring 48. The mode-changing ring 13 and the cam ring 48 can be integrally rotatable. The hammer shift ring 43 holds a shift cam 43C, allowing the shift cam 43C to move forward and backward. The hammer shift ring 43 is inserted into a guide hole provided in the gearbox housing 4B. Rotation of the hammer shift ring 43 is restricted by a guide groove provided in the gearbox housing 4B. The shift cam 43C is biased forward by a spring 43E, which is held by the gearbox housing 4B. When the user operates (manually rotates) the mode switch ring 13 in a predetermined direction, the switching cam 43C is pushed by the mode switch ring 13 and moves backward.When the user operates the mode selector ring 13 in the opposite direction (manually rotates it), the selector cam 43C is pressed by the spring 43E and returns to its forward position. As the selector cam 43C moves back and forth between a forward (front) position and a retracted (rear) position, the operating mode changes accordingly between hammer mode and non-hammer mode. Thus, manually rotating the mode selector ring 13 changes the operating mode from hammer mode to non-hammer mode and vice versa. The hammer mode is characterized by the blocking of the rotation of the second cam 42. The non-hammer mode is characterized by the allowing of the rotation of the second cam 42. The rotation of the second cam 42 is blocked when the switching cam 43C is moved to the advanced (front) position. The rotation of the second cam 42 is allowed when the switching cam 43C is moved to the retracted (rear) position. In hammer mode, at least a portion of the switching cam 43C, which has been moved to the advanced (front) position, comes into contact with the second cam 42. The rotation of the second cam 42 is blocked due to the contact between the switching cam 43C and the second cam 42. When the motor 6 is driven with the rotation of the second cam 42 blocked, the first cam 41, which is fixed to the spindle 81, rotates while in contact with the cam teeth of the second cam 42. This causes the spindle 81 to rotate while being hammered in the front-back (axial) direction. In the non-hammer mode, the switching cam 43C, which has been moved to the retracted position, is spaced apart from the second cam 42. Rotation of the second cam 42 is permitted because the switching cam 43C and the second cam 42 are spaced apart (i.e., in a non-contact state). When the motor 6 is driven, with rotation of the second cam 42 permitted, the second cam 42 rotates together with the first cam 41 and the spindle 81. This causes the spindle 81 to rotate without being hammered in the front-back (axial) direction. The hammer switching ring 43 is arranged around the first cam 41 and the second cam 42. Furthermore, the switching cam 43C has an opposing region 43S, which faces the rear surface of the second cam 42. The opposing region 43S projects radially inwards from a rear region of the switching cam 43C. When the mode selector ring 13 is actuated (manually rotated), and the selector cam 43C is moved to the advanced (front) position, the tab on the rear surface of the second cam 42 comes into contact with the opposite area 43S of the selector cam 43C. This blocks the rotation of the second cam 42. Thus, the hammer mechanism 40 is switched to the hammer mode, since the selector cam 43C has been moved to the advanced position. On the other hand, when the mode-changing ring 13 is actuated (manually rotated in the opposite direction) and the switching cam 43C is moved to the retracted position, the opposite area 43S of the switching cam 43C is spaced from the second cam 42. Therefore, rotation of the second cam 42 is enabled. Thus, when the mode-changing ring 13 is manually rotated and the switching cam 43C is thereby moved to the retracted position, the hammer mechanism 40 is switched to the non-hammer mode. Fig. 7 is a front perspective view showing part of the power tool 1 according to the embodiment. Fig. 8 is a side view showing part of the power tool 1 according to the embodiment. Fig. 9 is a cross-sectional view of part of the power tool 1 according to the embodiment. Fig. 10 is a front perspective exploded view showing the speed reduction mechanism 30 according to the embodiment. Fig. 11 is a rear perspective view showing part of the speed reduction mechanism 30 according to the embodiment. It should be noted that, for the sake of simplicity, the drawings omit representations of the specific shape of the teeth of meshing gears. The first planetary gear mechanism 31 comprises a plurality of planet gears 31P, a first carrier 31C, and an internal gear 31R. The first carrier 31C supports the plurality of planet gears 31P. The internal gear 31R is arranged around the plurality of planet gears 31P. The drive gear 31S is located at the front end of the rotor shaft 63 (see Fig. 5). The drive gear 31S functions as a sun gear of the first planetary gear mechanism 31. The drive gear 31S is located at the front of the stator 61. The drive gear 31S is rotated by the rotor 62. The drive gear 31S can be rotated directly or indirectly by the rotor 62. The planet gears 31P are arranged around the drive gear 31S. The second planetary gear mechanism 32 comprises a sun gear 32S, a plurality of planet gears 32P, a second carrier 32C, and an internal gear 32R. The planet gears 32P are arranged around the sun gear 32S. The second carrier 32C supports the plurality of planet gears 32P. The internal gear 32R is arranged around the plurality of planet gears 32P. The sun gear 32S is located on the front side of the internal gear 32R. The sun gear 32S can be rotated directly or indirectly by the planet gears 32P. The planet gears 32P mesh with the sun gear 32S. The internal gear 32R meshes with the plurality of planet gears 32P. The third planetary gear mechanism 33 comprises a sun gear 33S, a plurality of planet gears 33P, the third support 33C, and an internal gear 33R. The planet gears 33P are arranged around the sun gear 33S. The third support 33C holds the plurality of planet gears 33P. The internal gear 33R is arranged around the plurality of planet gears 33P. The gearbox housing 4A and the gearbox enclosure 4B are arranged at the front of the stator 61. The gearbox housing 4A accommodates the drive gear 31S, the planet gears 31P, the internal gear 31R, the first support 31C, the sun gear 32S, the planet gears 32P, and the internal gear 32R. The gearbox enclosure 4B accommodates the second support 32C, the sun gear 33S, the planet gears 33P, the internal gear 33R, a locking ring 37, and the third support 33C. The planet gears 31P are each rotatably mounted on first pins 31A. The first pins 31A are mounted on the first support 31C. The first pins 31A project rearward from the rear surface of the first support 31C. The first pins 31A are spaced apart circumferentially. In this embodiment, five first pins 31A are equally spaced circumferentially. The five planet gears 31P are each mounted on the five first pins 31A. The planet gears 31P are located on the rear side of the first support 31C. The first support 31C rotatably mounts the five planet gears 31P via their respective first pins 31A. An external gear 31K is provided on the outer circumference of the first support 31C. The internal gear 31R is arranged around the majority of planetary gears 31P. The sun gear 32S is located on the front side of the first support 31C. The diameter of the sun gear 32S is smaller than the diameter of the first support 31C. The first support 31C and the sun gear 32S rotate together. The first support 31C and the sun gear 32S can be integrated or separate (separate parts). Pins 32A are provided on the second support 32C. The planet gears 32P are each rotatably mounted on the pins 32A. The second support 32C rotatably mounts the planet gears 32P via the respective pins 32A. The sun gear 33S is located on the front side of the second support 32C. The diameter of the sun gear 33S is smaller than the diameter of the second support 32C. The second support 32C and the sun gear 32S rotate together. The second support 32C and the sun gear 33S can be integrated or separate (separate parts). Pins 33A are provided on the third support 33C. The planet gears 33P are each rotatably mounted on the pins 33A. The third support 33C rotatably mounts the planet gears 33P via the respective pins 33A. The third support 33C rotates integrally with the spindle 81, as described above. Fig. 12 is a side view showing a speed-changing mechanism 36 according to the embodiment. Fig. 13 is a perspective view showing the speed-changing mechanism 36 according to the embodiment, viewed from the bottom right rear. The speed reduction mechanism 30 incorporates the speed-changing mechanism 36. The speed-changing mechanism 36 is switchable between low-speed mode and high-speed mode. In the embodiment, the speed reduction function of the second planetary gear mechanism 32 is activated in the low-speed mode. In the high-speed mode, the speed reduction function of the second planetary gear mechanism 32 is deactivated. Activating the second planetary gear mechanism 32 blocks the rotation of the internal gear 32R. Deactivating the second planetary gear mechanism 32 allows the rotation of the internal gear 32R. The speed-changing mechanism 36 comprises the speed-changing lever 12, a switching wire 50, and the locking ring 37. The speed-changing mechanism 36 can be switched between the low-speed mode and the high-speed mode by moving the internal gear 32R in the forward-backward direction using the switching wire 50. The switching wire 50 is a metal wire component that possesses a stiffness (spring constant) required to move the internal gear 32R. The switching wire 50 is located on the outside of the gearbox housing 4A. The switching wire 50 is movable in the forward-reverse direction on the outside of the gearbox housing 4A. A tip portion of the switching wire 50 is inserted into a groove 32E provided on the internal gear 32R. As shown in Figures 7 and 8, through-holes 4J are provided in the gearbox housing 4A. The switching wire 50 passes through the through-holes 4J of the gearbox housing 4A and couples the speed-changing lever 12 to the speed reduction mechanism 30. The speed-changing lever 12 is located above the gearbox housing 4A. An upper end portion of the switching wire 50 is fixed to the lower surface of the speed-changing lever 12.The tip of the switching wire 50 is positioned inside the gearbox housing 4A via the through holes 4J. The tip of the switching wire 50 is inserted into the groove 32E inside the gearbox housing 4A. The switching wire 50 and the internal gear 32R move integrally in the forward-reverse direction. An upper portion of the switching wire 50 is fixed to the speed-changing lever 12. The speed-changing lever 12 is positioned above the gearbox housing 4A. The speed-changing lever 12 holds the switching wire 50 against its lower surface, which faces the gearbox housing 4A. The speed-changing lever 12 and the switching wire 50 move integrally in the forward-reverse direction. Therefore, when the speed-changing lever 12 is actuated (manually moved) in the forward-reverse direction, the internal gear 32R moves in the forward-reverse direction when the switching wire 50 moves in the forward-reverse direction. The locking ring 37 is located on the front side of the internal gear 32R. The locking ring 37 is received in the gear housing 4B. The locking ring 37 is positioned between the inner surface of the gear housing 4B and the front end surface of the gear housing 4A, thus blocking movement of the locking ring 37 in the forward-backward direction. A plurality of projections 37A are provided on the outer circumferential surface of the locking ring 37. The projections 37A are located inside recesses 4G (see Fig. 7) formed in the front end surface of the gear housing 4A to prevent rotation of the locking ring 37. The locking ring 37 has an inner diameter that is larger than the outer diameter of the internal gear 32R. The internal gear 32R can be inserted into and removed from the locking ring 37.A plurality of cam teeth 37B are provided on the inner circumferential surface of the locking ring 37. A plurality of cam teeth 32F are provided on the outer circumferential surface of the internal gear 32R. The cam teeth 32F are formed on the front side of the groove 32E. The cam teeth 32F mesh with the cam teeth 32B of the locking ring 37. By inserting the internal gear 32R into the locking ring 37, rotation of the internal gear 32R is blocked by the cam teeth 37B of the locking ring 37. Manually moving the speed-changing lever 12 in the forward-reverse direction moves the switching wire 50 in the forward-reverse direction, which in turn moves the internal gear 32R in the same direction. Moving the internal gear 32R in the forward-reverse direction switches it from the state in which it is engaged in the locking ring 37 to the state in which it is disengaged from the locking ring 37, and vice versa. By moving the speed-changing lever 12, the switching wire 50, and the internal gear 32R forward, inserting at least part of the internal gear 32R into the locking ring 37, and the cam teeth 32F and the internal gear 32R meshing with the cam teeth 37B of the locking ring 37, rotation of the internal gear 32R is blocked. That is, by moving the speed-changing lever 12, the switching wire 50, and the internal gear 32R forward and blocking the rotation of the internal gear 32R, the second planetary gear mechanism 32 is activated. On the other hand, by moving the speed-changing lever 12, the switching wire 50, and the internal gear 32R backwards, removing the internal gear 32R from the inside of the locking ring 37, and separating the cam teeth 32F of the internal gear 32R from the cam teeth 37B of the locking ring 37, the rotation of the internal gear 32R is enabled. That is, by moving the speed-changing lever 12, the switching wire 50, and the internal gear 32R backwards and enabling the rotation of the internal gear 32R, the second planetary gear mechanism 32 is deactivated. When the second planetary gear mechanism 32 is activated, the internal gear 32R meshes only with the planetary gears 32P. When the second planetary gear mechanism 32 is deactivated, the internal gear 32R meshes with both the planetary gears 32P and the external gear 31K on the outer circumferential area of ​​the first carrier 31C. Fig. 14 shows the power tool 1 in a case where the speed reduction mechanism 30 is set to the low-speed mode according to the embodiment, as seen from above. Fig. 15 is a cross-sectional view showing the speed reduction mechanism 30 in a case where it is set to the low-speed mode according to the embodiment. Fig. 16 shows the power tool 1 in a case where the speed reduction mechanism 30 is set to the high-speed mode according to the embodiment, as seen from above. Fig. 17 is a cross-sectional view showing the speed reduction mechanism 30 in a case where it is set to the high-speed mode according to the embodiment. Fig. 18 is a horizontal cross-sectional view of an engagement point between the speed-changing lever 12 and the housing 2, as seen from above. The movable area of ​​the speed-changing lever 12 is defined in the forward-reverse direction. The movable area has a linear shape along the forward-reverse direction. The movable area is along the axis of rotation AX. In this embodiment, the movable area is defined by an inner circumferential edge of an opening 2A formed in the housing 2. The opening 2A is formed in an upper region of the housing 2. The opening 2A exposes the upper surface of the speed-changing lever 12. A knob portion (tab, rib) 12A is formed on the upper surface of the speed-changing lever 12. The knob portion 12A projects upward into the opening 2A. The speed-changing lever 12 is movable (slidable) within the movable range, which has a plurality of speed-changing positions. In this embodiment, the speed reduction mechanism 30 has a two-stage gear-shifting mechanism, and therefore two speed-changing positions, corresponding to the low-speed mode and the high-speed mode respectively, are defined within the movable range. A speed-changing position for the low-speed mode is defined at the front end of the movable range. A speed-changing position for the high-speed mode is defined at the rear end of the movable range. By actuating the speed change lever 12 so that it moves (is shifted) to the speed change position for the low-speed mode at the front, the speed mode of the speed reduction mechanism 30 is set to the low-speed mode (speed "1"). By actuating the speed change lever 12 so that it moves to the speed change position for the high-speed mode at the rear, the speed mode of the speed reduction mechanism 30 is set to the high-speed mode (speed "2"). As shown in Fig. 18, the speed-changing lever 12 moves in the forward-backward direction while being guided by the housing 2 on both the right and left sides. The speed-changing lever 12 is actuated (manually moved) by the user, and the speed-changing lever 12 moves in the forward-backward direction. Leaf springs 12B (see Fig. 7) with projections 12C are arranged on both the right and left side surfaces of the speed-changing lever 12. The leaf springs 12B come into contact with the guide surfaces 2G of the housing 2 at the projections 12C and slide as they deform along the guide surfaces 2G when the speed-changing lever 12 moves. Engagement recesses 2H are formed on the guide surfaces 2G.When the projections 12C of the leaf springs 12B reach the positions of the engagement recesses 2H, elastic restoring forces of the leaf springs 12B cause the projections 12C to engage in the engagement recesses 2H. The projections 12C engage in the engagement recesses 2H, thereby holding the position of the speed-changing lever 12 in such a way that it is not moved by an unwanted external force. The engagement recesses 2H are formed at the speed-changing position for the low-speed mode and at the speed-changing position for the high-speed mode. When switching between the low-speed and high-speed modes, an external force exceeding a predetermined level is applied to the speed-changing lever 12. This causes the leaf springs 12B to deform elastically, and the projections 12C move away from (out of) the engagement recesses 2H.This releases the engagement between the projections 12C and the engagement recesses 2H, allowing the speed change lever 12 to move. As shown in Figs. 14 and 15, when the speed-changing lever 12 is in the speed-changing position for the low-speed mode (the front end of its movable range), the switching wire 50 and the internal gear 32R are positioned at the front in the low-speed mode position. The internal gear 32R is inserted into the locking ring 37 and is blocked from rotation by the locking ring 37. When the rotor shaft 63 is rotated by the motor 6 with the internal gear 32R in the low-speed mode position, the drive gear 31S rotates and the planet gears 31P rotate around the drive gear 31S. The rotation of the planet gears 31P causes the first carrier 31C and the sun gear 32S to rotate at a speed lower than that of the rotor shaft 63. When the sun gear 32S rotates, the planet gears 32P rotate around the sun gear 32S (within the circumference of the inner gear 32R).The rotation of the planetary gears 32P causes the second carrier 32C and the sun gear 33S to rotate at a lower speed than the first carrier 31C. Thus, when the motor 6 is driven, with the inner gear 32R in the low-speed mode position, both the speed reduction function of the first planetary gear mechanism 31 and the speed reduction function of the second planetary gear mechanism 32 are exercised. Therefore, the second carrier 32C and the sun gear 33S rotate in the low-speed mode. As shown in Figs. 16 and 17, when the speed-changing lever 12 is in the speed-changing position for the high-speed mode (rear end of its movable range), the switching wire 50 and the internal gear 32R are positioned at the rear in the high-speed mode. The internal gear 32R is away from the locking ring 37, allowing the internal gear 32R to rotate within the gearbox housing 4A. When the rotor shaft 63 is rotated by the motor 6 with the internal gear 32R in the high-speed mode position, the drive gear 31S rotates, and the planet gears 31P rotate around the drive gear 31S. The rotation of the planet gears 31P causes the first carrier 31C and the sun gear 32S to rotate at a speed lower than that of the rotor shaft 63.The internal gear 32R meshes with both the planet gears 32P and the external gear 31K of the first carrier 31C, with the internal gear 32R being in the high-speed mode position, causing the internal gear 32R and the first carrier 31C to rotate together. The rotation of the internal gear 32R causes the planet gears 32P to rotate at a speed equal to the rotation of the internal gear 32R. The rotation of the planet gears 32P causes the second carrier 32C and the sun gear 33S to rotate at a speed equal to that of the first carrier 31C. As described above, when the motor 6 is driven in high-speed mode, the speed reduction function of the second planetary gear mechanism 32 is not exercised, but the speed reduction function of the first planetary gear mechanism 31 is exercised. Thus, the second carrier 32C and the sun gear 33S rotate in high-speed mode. Switch wire and mounting structure gearbox housing The following describes the shape of the switching wire 50 and a mounting structure of the gearbox housing 4A according to the embodiment. Fig. 19 is a rear perspective view showing the gearbox housing 4A, the motor mount 4C, and the gearbox enclosure 4B according to the embodiment. Fig. 20 is a rear perspective exploded view showing the gearbox housing 4A, the motor mount 4C, and the gearbox enclosure 4B according to the embodiment. Fig. 21 is a bottom perspective view showing the speed-changing lever 12 and the switching wire 50 according to the embodiment. Fig. 22 is a rear perspective view showing the gearbox housing 4A and the switching wire 50 according to the embodiment. As shown in Fig. 19 and Fig. 20, in this embodiment the gearbox housing 4A is fixed to the motor mount 4C and the gearbox enclosure 4B by separate screws. Specifically, the gearbox housing 4A has a cylindrical part 70, a plurality of mounting attachments 71, and a plurality of enclosure attachments 72. The mounting attachments 71 are screw receptacles to which screws 4R are attached to fix the motor mount 4C. The motor mount 4C is fixed to the mounting attachments 71 by screws 4R. The enclosure attachments 72 are screw insertion areas into which screws 4Q are inserted to fix the gearbox housing 4A to the gearbox enclosure 4B. The gearbox housing 4A is fixed to the gearbox enclosure 4B by the screws 4Q that are inserted into the enclosure attachments 72. As shown in Fig. 21, the cylindrical part 70 is a body region of the gearbox housing 4A and has a cylindrical shape extending in the front-to-back direction. The gearbox housing 4A accommodates the speed reduction mechanism 30 inside the cylindrical part 70. A front and a rear end of the cylindrical part 70 are open. A first mating surface 73 with the motor mount 4C is formed on the end surface of the rear end of the cylindrical part 70. A flange region 74 is provided at a front end of the cylindrical part 70. The flange region 74 extends radially outward. An outer circumferential surface 70A of the cylindrical part 70 is essentially formed by a circumferentially curved surface. The cylindrical part 70 has through holes 4J that penetrate it radially. That is, the through holes 4J extend through the cylindrical part 70 from the outer circumferential surface to the inner circumferential surface. The connecting wire 50 is inserted into the through holes 4J. The through-holes 4J are long holes extending along the front-back direction and allow the movement of the switching wire 50 in the front-back direction in accordance with an actuation (movement) of the speed-changing lever 12. The through-holes 4J have a length in the front-back direction that is equal to or greater than the range of movement of the switching wire 50 in the front-back direction, i.e., equal to or greater than the length of the movable range of the speed-changing lever 12. The gearbox housing 4A has two through-holes 4J, provided on one side and on the other side in a lateral direction (left-right direction).The one side and the other side in the lateral direction are namely a right side surface and a left side surface of the gearbox housing 4A. The through holes 4J are arranged on the right and left sides with respect to the central axis of the cylindrical part 70. The mounting brackets 71 are provided on the outer circumference of the cylindrical part 70. In this embodiment, three mounting brackets 71 are provided. Each mounting bracket 71 projects radially outward from an outer circumferential surface 70A of the cylindrical part 70. Each mounting bracket 71 extends in the front-to-back direction from the front end to the rear end of the cylindrical part 70. Screw holes 71H are formed in each mounting bracket 71. The screw holes 71H extend in the front-to-back direction. The screws 4R mesh with these screw holes 71H and are mounted on them. This ensures that the motor mount 4C is fixed to the mounting brackets 71 by the screws 4R. The housing extensions 72 are provided on the outer circumference of the cylindrical part 70. In this embodiment, three housing extensions 72 are provided. The housing extensions 72 are provided at the front end of the cylindrical part 70. At the flange region 74 of the gearbox housing 4A, the housing extensions 72 are provided radially outside the circumferential surface 70A of the cylindrical part 70. The housing extensions 72 have a thickness in the front-to-back direction that is greater than that of any other area of ​​the flange region 74. Each housing extension 72 has a lead-in hole 72H. The lead-in holes 72H extend in the front-to-back direction. The screws 4Q are inserted into the lead-in holes 72H. The screws 4Q, which were passed through the insertion holes 72H, are mounted in the screw holes 4H which are formed in the gearbox housing 4B.This causes the gearbox housing 4A to be fixed to the gearbox enclosure 4B by the screws 4Q, which have passed through the three enclosure attachment parts 72. The arrangement of the mounting parts 71 and the housing parts 72 for the gearbox housing 4A will be described later. As shown in Figs. 21, 22, 23 to 24, the switching wire 50 has a first wire section 50R, provided on one side (right side), and a second wire section 50L, provided on the other side (left side). Each of the first wire section 50R and the second wire section 50L has a wire segment 51, a second wire segment 52, and a third wire segment 53. The first wire segments 51 extend from the speed-changing lever 12 to the cylindrical part 70 when viewed in the axial direction. The second wire segments 52 extend circumferentially along the outer circumferential surface 70A of the cylindrical part 70 from one end of the first wire segment 51. The third wire segments 53 are inserted from one end of the second wire segment 52 into the through-hole 4J. The switching wire 50 is inserted into the through-holes 4J provided on one side and the other side of the gearbox housing 4A. As described above, the switching wire 50 has the first wire section 50R on one side (right side) and the second wire section 50L on the other side (left side). The first wire section 50R is inserted into the through-hole 4J on one side (right side). The second wire section 50L is inserted into the through-hole 4J on the other side (left side). The first wire section 50R has the first wire segment 51, the second wire segment 52, and the third wire segment 53 on the right side. The second wire section 50L has the first wire segment 51, the second wire segment 52, and the third wire segment 53 on the left side. The switching wire 50 is essentially symmetrical.The first wire section 50R and the second wire section 50L have the same structure and are symmetrical in the left-right direction. Being essentially symmetrical means that even if there is an unavoidable difference, such as a dimensional tolerance (resulting in an asymmetrical shape), they are still considered symmetrical. The first wire section 50R and the second wire section 50L are connected to each other via their first wire segments 51. The connecting wire 50 has a connection section 54 that connects an upper end of the first wire segment 51 of the first wire section 50R to an upper end of the first wire segment 51 of the second wire section 50L. The connection section 54 extends along the left-right direction. In this embodiment, the connecting wire 50 is a single part comprising the first wire section 50R and the second wire section 50L, which are connected by the connection section 54. Alternatively, the first wire section 50R and the second wire section 50L can be separate parts. The first wire segments 51 extend along an up-down direction between the speed-changing lever 12 and the cylindrical part 70. The first wire segments 51 have a linear shape. The upper ends of the first wire segments 51 are connected to the connecting area 54. The lower ends of the first wire segments 51 are located in the vicinity of the outer circumferential surface of the cylindrical part 70 of the gearbox housing 4A. The lower ends of the first wire segments 51 are opposite the outer circumferential surface of the cylindrical part 70 with a small gap between them. The first wire segments 51 are not in contact with the outer circumferential surface of the cylindrical part 70. The second wire segments 52 connect the ends of the first wire segments 51 with the ends of the third wire segments 53. The second wire segments 52 extend in an arc shape along the outer circumferential surface 70A of the cylindrical part 70. The second wire segments 52 lie opposite the outer circumferential surface 70A of the cylindrical part 70 with a small gap between them. The third wire segments 53 are connected to the ends of the second wire segments 52. The third wire segments 53 are positioned radially opposite the through-holes 4J of the gear housing 4A. The third wire segments 53 are bent slightly forward from the ends of the second wire segments 52 and then extend radially inward. The tips of the third wire segments 53 pass through the through-holes 4J of the cylindrical part 70 and are located inside the cylindrical part 70. This results in the tips of the third wire segments 53 being located inside the groove 32E of the internal gear 32R. As shown in Fig. 22, the switching wire 50 has a held section 50F, which is held by the speed-changing lever 12. In this embodiment, the held section 50F has the connecting section 54. Specifically, a retaining groove 12T is formed in the lower surface of the speed-changing lever 12. The retaining groove 12T is recessed upwards and extends in the left-right direction. The connecting section 54 on an upper section of the switching wire 50 fits into the retaining groove 12T. A pair of retaining arms 12L is provided on the lower surface of the speed-changing lever 12. The pair of retaining arms 12L projects downwards towards the gearbox housing 4A. The pair of retaining arms 12L is located on the right and left sides of the retaining groove 12T. The pair of retaining arms 12L extends towards the upper ends of the second wire segments 52 (immediately upstream of the connection points with the first wire segments 51) of the switching wire 50. The retaining groove 12T extends continuously from the inner side surfaces to the lower end surfaces of the pair of retaining arms 12L. The inner side surfaces of the pair of retaining arms 12L are those opposite each other in the left-right direction. The retaining groove 12T extends in the top-bottom direction along the inner side surfaces of the pair of retaining arms 12L.The retaining groove 12T extends along the left-right direction on the lower end surfaces of the pair of retaining legs 12L. The first wire segments 51 and the surroundings of the upper ends of the second wire segments 52 of the switching wire 50 are fitted into the retaining grooves 12T formed on the pair of retaining arms 12L. The first wire segments 51 are arranged in the retaining groove 12T of the inner side surfaces of the pair of retaining arms 12L. The surroundings of the upper ends of the second wire segments 52 are fitted into the retaining groove 12T formed on the lower end surfaces of the pair of retaining arms 12L. Therefore, in this embodiment, the retained area 50F further comprises the pair of first wire segments 51 and the surroundings of the upper ends of the pair of second wire segments 52 in addition to the connection area 54. The retained area 50F is arranged in the retaining groove 12T, thereby fixing the switching wire 50 to the speed-changing lever 12. The positional relationship between the segments of the switching wire 50 and the gearbox housing 4A is described in detail below. Fig. 23 is an arrow view of the gearbox housing 4A and the switching wire 50 according to the embodiment, viewed axially from the rear. Fig. 24 is an enlarged view of the area surrounding the first wire segment 51 and the second wire segment 52 of the switching wire 50 in Fig. 23. The gearbox housing 4A according to the embodiment has a structure in which the path length of the switching wire 50 can be shortened. The path length of the switching wire 50 in the present embodiment refers to the length of the switching wire 50 from one end of the switching wire 50, which is held by the speed-changing lever 12 (i.e., the retaining leg 12L), to a bent region (boundary region between the second wire segment 52 and the third wire segment 53) on a tip side. The path length of the switching wire 50 corresponds to the length of the second wire segment 52. For the purpose of specifying the position of the gearbox housing 4A, a first area G1 and a second area G2, the following is defined. The first regions G1 are regions that are radially opposite the second wire segment 52 of the connecting wire 50 on the outer circumference of the cylindrical part 70. These regions are located at angular intervals between the ends (areas of connection with the first wire segments 51) and the other ends (positions of the through-holes 4J) of the second wire segments 52 in the circumferential direction of the cylindrical part 70. Since the first wire region is 50R and the second wire region is 50L, the first regions G1 are located on one side and the other side of the cylindrical part 70 in the left-right direction. These first regions G1 can be described as regions obtained by removing a third region G3 between the pair of first wire segments 51 on the upper half of the circumferential surface 70A of the cylindrical part 70. The second region G2 is located below the through holes 4J on the outer circumferential surface of the cylindrical part 70. The second region G2 is not radially opposite the second wire segments 52 of the switching wire 50 on the outer circumference of the cylindrical part 70. In this embodiment, the through holes 4J are located on both the right and left sides (i.e., in the center in the top-bottom direction) with respect to the central axis of the cylindrical part 70, so that the second region G2 is a lower half-region of the outer circumferential surface 70A of the cylindrical part 70. The second region G2 can be described as a non-opposing region that is not radially opposite the switching wire 50 on the outer circumference of the cylindrical part 70. Mounting bracket In this embodiment, the mounting elements 71 of the gearbox housing 4A are provided on the outer circumference of the cylindrical part 70 at positions other than the first regions G1, which are radially opposite the second wire segments 52. Each of the three mounting elements 71 is not located in the first regions G1, but rather outside the first regions G1 of the cylindrical part 70 in the circumferential direction. Thus, the second wire segments 52 of the switching wire 50 are not radially opposite the mounting elements 71. Therefore, the second wire segments 52 can have an arc shape along the outer circumferential surface 70A of the cylindrical part 70 without extending around the outer circumferences of the mounting elements 71. Specifically, the mounting components 71 have the first attachment 71A and the two second attachments 71B. The first attachment 71A is located between the first wire segment 51 of the first wire section 50R and the first wire segment 51 of the second wire section 50L. The first attachment 71A is positioned in the third section G3 between the first section G1 on one side (right side) and the first section G1 on the other side (left side) in the left-right direction. The first attachment 71A is located at the position where the cylindrical part 70 is opposite the speed-changing lever 12. That is, the first attachment 71A is located at the upper end of the center of the cylindrical part 70 in the left-right direction. The first approach 71A is provided at a position opposite the held area 50F of the switching wire 50 in the radial direction when viewed in the axial direction.In this embodiment, the held area 50F comprises the pair of first wire segments 51 and the connection area 54 of the connecting wire 50. The first projection 71A is surrounded by the pair of first wire segments 51 and the connection area 54. That is, in the connecting wire 50, the pair of first wire segments 51 and the connection area 54 form a rectangular recessed space that extends upwards. The first projection 71A is arranged inside this rectangular recessed shape. The second projections 71B are provided in the second region G2 below the through holes 4J on the outer circumference of the cylindrical part 70. The second projections 71B are arranged on one side and the other side in the lateral direction of the cylindrical part 70 in the second region G2. That is, the two second projections 71B are arranged between the lateral ends of the cylindrical part 70 and the lower end of the cylindrical part 70. The two second projections 71B are arranged on one side (right side) and the other side (left side) of the first projection 71A. In an example from Fig. 23, if the angle about the central axis of the cylindrical part 70 with the upper end of the cylindrical part 70 is defined as 0 degrees, the first projection 71A is located at the 0-degree position. The second projections 71B are located at positions of approximately 140 degrees to the right and left. In this way, the three mounting projections 71 are arranged in a triangular shape when viewed axially. The distances in the left-right direction between the second projections 71B and the first projection 71A are equal. The three mounting projections 71 are arranged in the shape of an isosceles triangle. In this way, the three mounting brackets 71 are positioned differently than at the first areas G1, thus eliminating the need for the second wire segments 52 of the switching wire 50 to run around the outside of the mounting brackets 71. This allows the second wire segments 52 to be positioned closer to the first areas G1 and to extend along them, thereby shortening the path length of the second wire segment 52. Furthermore, the first wire segments 51 and the connecting area 54 project upwards (radially outwards) to be coupled to the speed-changing lever 12. The first attachment 71A is not located within the first areas G1, but rather in such a projecting area, so that the mounting brackets 71 do not increase the path length of the switching wire 50. As shown in Fig. 24, a radial distance CL between the second wire segment 52 of the connecting wire 50 and the outer circumferential surface 70A of the cylindrical part 70 in the first region G1 is smaller than a projection EP of the mounting part 71 with respect to the outer circumferential surface 70A in the first region G1. The projection EP of the mounting parts 71 with respect to the outer circumferential surface 70A of the first region G1 is the difference between a radius R1 and a radius R2. The radius R1 is a distance from the central axis of the cylindrical part 70 to the outer circumferential surface 70A of the first region G1. The radius R2 is a distance from the central axis of the cylindrical part 70 to a point (referred to as an outermost point) on the radially outermost side of the mounting attachment part 71. The first attachment 71A among the three mounting attachment parts 71 has the smallest projection EP.The distance CL is smaller than the projection EP of the first section 71A. The entire second wire segment 52 is located radially inside the outermost point of the first section 71A. Restricting ribs 70B (see Fig. 21) are provided at positions opposite the second wire segments 52 on the outer circumferential surface 70A of the cylindrical part 70. The restricting ribs project slightly radially outwards. The restricting ribs 70B are located slightly above the area surrounding the through holes 4J. In principle, the restricting ribs 70B are non-contacting the second wire segments 52 in the radial direction.If the second wire segment 52 is displaced (deformed) radially inward from its design position due to vibration caused by a speed-changing lever 12 or movement of the power tool 1, a dimensional deviation within a tolerance range, or the like, the confining rib 70B comes into contact with the second wire segment 52, thereby preventing it from contacting the outer circumferential surface 70A of the cylindrical part 70. Therefore, the second wire segment 52 is not in contact with the outer circumferential surface 70A of the cylindrical part 70, except for the confining rib 70B. The minimum value of the distance CL of the second wire segment 52 corresponds to the height (the overhang) of the confining rib 70B and is not zero. The height (protrusion dimension) of the confining rib 70B from the outer circumferential surface 70A of the cylindrical part 70 is smaller than the wire diameter of the hook-up wire 50.The height (protrusion) of the confining rib 70B is less than half the wire diameter of the connecting wire 50. Furthermore, the distance CL between the second wire segment 52 and the outer circumferential surface 70A, excluding the confining rib 70B, is less than the wire diameter of the connecting wire 50. In the example of Fig. 24, the distance CL between the second wire segment 52 and the outer circumferential surface 70A, excluding the confining rib 70B, is less than half the wire diameter of the connecting wire 50. When the switching wire 50 is in the position for the low-speed mode, which is the front end of its movable range, the switching wire 50 is fitted into the groove 32E, with the tip region of the switching wire 50 elastically deformed backwards. In particular, as shown in Fig. 12, the switching wire 50 is designed such that, when it is in a position for the low-speed mode, the tip end region of the third wire segment 53 is arranged at its design position DP, which is offset forwards from the groove 32E. When the switching wire 50 and the internal gear 32R are in the low-speed mode position at the front, the front surface of the internal gear 32R comes into contact with the cam teeth 37B of the locking ring 37, thus preventing further forward movement. The switching wire 50 is elastically deformed, so that its tip is displaced rearward from its design position DP to the position of the groove 32E. For the sake of simplicity, the elastic deformation of the switching wire 50 is not shown in the figures. When the internal gear 32R is in the low-speed mode position at the front, the tip of the switching wire 50 is elastically deformed backward, causing the switching wire 50 to bias the internal gear 32R forward toward the locking ring 37 by an elastic restoring force. The internal gear 32R is biased toward the locking ring 37, preventing it from shifting backward. Thus, even if a reaction force from another gear and the locking ring 37, an oscillation when the power tool 1 moves, or similar forces act on the internal gear 32R, positional displacement of the internal gear 32R is prevented, thereby suppressing any unintentional disengagement of the engagement with the locking ring 37. The strength of the forward preload force acting on the internal gear 32R depends on the spring constant (stiffness) of the switching wire 50. In this embodiment, the path length of the switching wire 50 can be shortened. Therefore, the spring constant of the switching wire 50 increases, and the preload force on the internal gear 32R can be increased. Consequently, unwanted positional displacement of the internal gear 32R can be effectively prevented, resulting in more reliable gear shifting. Enclosure attachment part As shown in Figs. 21 and 23, the majority of the housing attachment parts 72 are arranged radially outside the connecting wire 50. The majority of (three) housing attachment parts 72 have two third attachments 72A and one fourth attachment 72B. The two third attachments 72A are arranged radially outside the connecting wire 50. The fourth attachment 72B is arranged in the second region G2, where the connecting wire 50 is not positioned. The third projections 72A are arranged in the first regions G1 of the outer circumferential surface 70A of the cylindrical part 70. The third projections 72A are provided in the first region G1 on one side where the first wire section 50R is located, and in the first region G1 on the other side where the second wire section 50L is located. That is, the third projections 72A are arranged on the outside of the second wire segment 52 of the first wire section 50R and on the outside of the second wire segment 52 of the second wire section 50L. The third projections 72A extend rearward from the flange region 74 at the front end of the gearbox housing 4A. The third projections 72A have cutouts 72C on their outer circumferential surfaces, facing the radial center of the cylindrical part 70. The cutouts 72C prevent the switching wire 50 from coming into contact with the third projections 72A. That is, areas opposite the outer circumferential surface 70A of the cylindrical part 70 in the radial direction of the outer circumferential surfaces of the third projections 72A are cut out. The surfaces of the cutouts 72C are substantially parallel to the outer circumferential surface 70A of the cylindrical part 70, opposite the surfaces of the cutouts 72C. When the switching wire 50 is located at the front end of the range of motion, i.e.,When the speed-changing lever 12 is in the speed-changing position for high-speed mode, the switching wire 50 is closest to the third prongs 72A. The cutout areas 72C are provided to prevent the switching wire 50 from coming into contact with the third prongs 72A in this state. The cutout areas 72C allow the third prongs 72A to be located outside the switching wire 50, but close to the radial inside. The fourth projection 72B is located in the second area G2, which is situated below the through holes 4J on the outer circumference of the cylindrical part 70. The fourth projection 72B is positioned between the third projections 72A in the left-right direction. The fourth projection 72B is positioned between the two second projections 71B of the mounting bracket parts 71 in the second area G2. The fourth projection 72B is located at the lower end of the cylindrical part 70. In the example of Fig. 23, if the angle about the central axis of the cylindrical part 70 with the upper end of the cylindrical part 70 is defined as 0 degrees, the two third projections 72A are arranged at positions approximately 47 degrees to the right and left. A fourth projection 72B is arranged at a position approximately 180 degrees. In this embodiment, the three enclosure projections 72 are arranged in an inverted triangular shape when viewed axially. The distances in the left-right direction between the third projections 72A and the second projections 72B are equal. The three enclosure projections 72 are arranged in the shape of an isosceles triangle pointing downwards. Screw fixing part In the configuration described above, the gearbox housing 4A has a separate screw fixing part that secures the motor mount 4C and a screw fixing part that is fixed to the gearbox enclosure 4B. Fig. 25 is a cross-sectional arrow view of a plane passing through the second wire segments 52 of the switching wire 50 when viewed axially from the rear. In Fig. 25, the speed reduction mechanism 30 inside the gearbox housing 4A is simplified for the sake of simplicity. The gearbox housing 4A has a first screw fixing element 75 located in a position opposite the held area 50F of the switching wire 50 in the radial direction when viewed in the axial direction. The first screw fixing element 75 secures the motor mount 4C. The first screw fixing element 75 is formed by the first projection 71A and a screw 4R. An insertion hole 94 is provided in the motor mount 4C. The screw 4R is inserted into the insertion hole 94. The screw 4R, having passed through the insertion hole 94 from the rear of the motor mount 4C, is then installed in a screw hole 71H of the first projection 71A. In the gearbox housing 4A, the first screw fixing element 75 is located in an opposite region GF, which is radially opposite the switching wire 50 when viewed axially. The opposite region GF is located above the through holes 4J. The opposite region GF includes both the pair of first regions G1 and the third region G3 between the pair of first regions G1. The first projection 71A is located in the third region G3. The gearbox housing 4A has a plurality of (two) secondary screw fixing elements 76 in the non-opposite region that is not radially opposite the switching wire 50 when viewed axially. The secondary screw fixing elements 76 fix the motor mount 4C. The non-opposite region is an area where the switching wire 50 is not located on the outer circumferential surface 70A of the cylindrical part 70. The non-opposite region is located below the through-holes 4J and coincides with the second region G2. The secondary screw fixing elements 76 are formed by the secondary projections 71B and screws 4R. The screws 4R, which pass through the insertion holes 94 from the rear of the motor mount 4C, are installed in the screw holes 71H of the secondary projections 71B. Therefore, the gearbox housing 4A is fixed to the motor mount 4C at three points by a first screw fixing element 75 and two second screw fixing elements 76. The three points are arranged in a triangular shape when viewed in the axial direction. The first screw fixing element 75 is located in the opposite region GF. The two second screw fixing elements 76 are located on one side and the other side in the lateral direction with respect to the center of the gearbox housing 4A in the non-opposite region (second region G2). Furthermore, the gearbox housing 4A has two third fixing parts 77, arranged at one position in the circumferential direction between the first screw fixing part 75 and the second screw fixing part 76, which is provided on one side, and at another position in the circumferential direction between the first screw fixing part 75 and the second screw fixing part 76, which is provided on the other side. A third projection 72A and a screw 4Q form a third screw fixing part 77. The screws 4Q, which have been passed through the insertion holes 72H of the third projections 72A from the rear of the gearbox housing 4A, are mounted in screw holes 4H of the gearbox enclosure 4B. In this embodiment, the third screw fixing parts 77 are arranged in the opposite region GF.The third screw fixing parts 77 are arranged radially outside the second wire segments 52 in the first area G1, in which the second wire segments 52 of the switching wire 50 are arranged, of the opposite area GF. The gearbox housing 4A has a fourth screw fixing part 78, which is arranged between the two second screw fixing parts 76 on one side and the other side in the non-opposite area (second area G2). The fourth projection 72B and the screw 4Q form the fourth screw fixing part 78. The screw 4Q, which is fitted through the insertion hole 72H of the fourth projection 72B from the rear of the gearbox housing 4A, is installed in the screw hole 4H of the gearbox housing 4B. Therefore, the gearbox housing 4A is fixed to the gearbox enclosure 4B at three points, arranged in an inverted triangular shape when viewed in the axial direction, by the two third fixing parts 77 and the one fourth screw fixing part 78. Fig. 26 is a perspective explanatory view showing the mating surfaces of the gearbox housing 4A and the motor mount 4C. Fig. 27 is an arrow view of a front surface 90 of the motor mount 4C, viewed axially from the front. As shown in Fig. 26, the gearbox housing 4A has the first mating surface 73, which has an annular, flat shape, on its rear end surface opposite the motor mount 4C. The first mating surface 73 includes the rear end surface of the cylindrical part 70 and the rear end surfaces of the three mount extension parts 71 (first extension 71A and second extensions 71B). The first mating surface 73 is flat. Positions on the first mating surface 73 are located in the same position in the front-to-back direction. The motor mount 4C has a second mating surface 91, which has an annular flat shape, on the front surface 90, which faces the gearbox housing 4A. The second mating surface 91 is in contact with the first mating surface 73. An opening 92 is provided at the center of the motor mount 4C. The front end of the rotor shaft 63 is inserted into the opening 92. The bearing 64 is located in the opening 92. The motor mount 4C rotatably supports the rotor shaft 63 via the bearing 64 in the opening 92. Four locating ribs 93 are provided on the front surface 90 of the motor mount 4C. The locating ribs 93 project forward. The locating ribs 93 have an arc shape that conforms to the inner circumferential surface of the cylindrical part 70 of the gearbox housing 4A. When the motor mount 4C is attached to the rear end surface of the gearbox housing 4A, the locating ribs 93 are fitted onto the inner circumferential surface of the cylindrical part 70. This achieves a positional alignment in the radial direction between the center of the motor mount 4C (i.e., the center axis of the rotor shaft 63) and the center axis of the gearbox housing 4A (i.e.,central axis of the speed reduction mechanism 30). The second mating surface 91 is formed between the mating ribs 93 and the outer circumferential edge of the motor mount 4C. The second mating surface 91 surrounds the outer circumference of the mating ribs 93. The insertion holes 94 for the screws 4R are provided on the second mating surface 91. The second mating surface 91 is flat. Positions on the second mating surface 91 are located in the same position in the front-to-back direction. As shown in Fig. 27, when the motor mount 4C is attached to the rear end surface of the gearbox housing 4A, the first mating surface 73 comes into contact with the second mating surface 91 in the front-to-back direction. Fig. 27 shows a contact area 95 with the first mating surface 73 of the second mating surface 91. In Fig. 27, the contact area 95 is hatched, and its outer circumferential edge is surrounded by dashed lines. Flat surfaces come into surface contact with each other in the contact area 95. The first mating surface 73 and the second mating surface 91 come into close contact with each other due to the axial force of the screws 4R. This prevents the outflow of a lubricant, such as grease, applied to each gear of the speed reduction mechanism 30, from the inside of the gearbox housing 4A. Beneficial effects As described above, in this embodiment the power tool 1 comprises the motor 6, the output part 8, the speed reduction mechanism 30, the gearbox housing 4A, the motor mount 4C, the speed change lever 12 (shifting actuator), and the switching wire 50. The output part 8 is located at the front of the motor 6 and is configured to be driven by the motor 6. The speed reduction mechanism 30 is arranged between the motor 6 and the output part 8 and has a gear-shifting function. The gearbox housing 4A comprises the cylindrical part 70, which has through holes 4J extending radially through it, and the plurality of mounting elements 71 provided on the outer circumference of the cylindrical part 70, which accommodates the speed reduction mechanism 30 inside the cylindrical part 70.The motor mount 4C is positioned between the motor 6 and the speed reduction mechanism 30 and is fixed to the majority of the mounting bracket parts 71 by the screws 4R. The speed-changing lever 12 (shift actuating part) is configured such that, when moved, it causes the speed reduction mechanism 30 to change the gear ratio. The shift wire 50 passes through the through-holes 4J of the gearbox housing 4A and connects the speed-changing lever 12 to the speed reduction mechanism 30. The shift wire 50 has first and second wire sections 50R and 50L, respectively, each of which has a first wire segment 51, a second wire segment 52, and a third wire segment 53. The first wire segments 51 extend from the speed-changing lever 12 to the cylindrical part 70 when viewed in the axial direction.The second wire segments 52 extend circumferentially along the outer circumferential surface 70A of the cylindrical part 70 from the ends of the first wire segments 51. The third wire segments 53 extend from the ends of the second wire segments 52 and are inserted into the through holes 4J. The mounting elements 71 are provided on the outer circumference of the cylindrical part 70 at positions other than the areas G1 that are radially opposite the second wire segments 52. In the configuration described above, the mounting brackets 71 of the gearbox housing 4A are located on the outer circumference of the cylindrical part 70 at positions other than the first regions G1, which are radially opposite the second wire segments 52. When the mounting brackets 71 are located in the first regions G1, the second wire segments 52 of the switching wire 50 wrap around the outside of the mounting brackets 71. In contrast, in the present configuration, the second wire segments 52 of the switching wire 50 connect the first wire segments 51 to the third wire segments 53 without wrapping around the outside of the mounting brackets 71. This can shorten the path length of the switching wire 50 leading to the speed reduction mechanism 30, thereby increasing the spring constant (stiffness) of the switching wire 50.Increasing the spring constant of the switching wire 50 makes it less likely that the switching wire 50 will bend slightly and allows a gear coupled via the switching wire 50 to be supported even when a reaction force acts on the gear. Consequently, positional displacement of the gear for a gear shift of the speed reduction mechanism 30 is less likely to occur, resulting in more reliable gear shifting. In this embodiment, the through holes 4J have two through holes 4J, one on one side and the other in a lateral direction. The first wire section 50R is provided on one side and inserted into the through hole 4J on that side. The second wire section 50L is provided on the other side and inserted into the through hole 4J on that side. The majority of the mounting attachment parts 71 have the first attachment 71A, which is arranged between the first wire segment 51 of the first wire section 50R and the first wire segment 51 of the second wire section 50L. In the configuration described above, the first mounting bracket part 71A can be positioned by utilizing the space between the first wire section 50R and the second wire section 50L. This ensures installation space for the mounting bracket part 71 (first mounting bracket 71A) without increasing the dimensions of the gearbox housing 4A and the motor mount 4C, while simultaneously reducing the path length of the switching wire 50. In this embodiment, the speed-changing lever 12 is arranged upwards from the gearbox housing 4A. The mounting parts 71 have the second projections 71B, which are arranged in the second area G2, located below the through holes 4J on the outer circumference of the cylindrical part 70. In the configuration described above, by arranging the second attachments 71B in the second area G2, located below the through-holes 4J, where the switching wire 50 is not positioned within the gearbox housing 4A, the number of fixing points for the motor mount 4C can be increased without rerouting the path of the switching wire 50. The gearbox housing 4A and the motor mount 4C can be firmly fixed to each other by the first attachment 71A and the second attachments 71B. This prevents, for example, the leakage of lubricant (grease) and the like. In this embodiment, second projections 71B are arranged on one side (right side) and the other side (left side) in the lateral direction of the cylindrical part 70 in the second area G2. In the configuration described above, by arranging the plurality of second projections 71B in the second area G2, where the switching wire 50 is not positioned inside the gearbox housing 4A, a plurality of fixing points for the motor mount 4C on the gearbox housing 4A can be distributed over a wider circumferential area. Consequently, the first projection 71A and the plurality of second projections 71B can fix the motor mount 4C more evenly. Again, in this case, the switching wire 50 does not need to run around the outside of the projections, and the reliability of a gearbox shift can be improved. In this embodiment, the radial distance CL between the second wire segment 52 of the switching wire 50 and the outer circumferential surface 70A of the cylindrical part 70 in the first region G1 is smaller than a projection EP of the mounting part 71 with respect to the outer circumferential surface 70A in the first region G1. In the configuration described above, the second wire segment 52 of the switching wire 50 is arranged radially inside the outer circumferential area of ​​the mounting part 71, and the distance CL between the second wire segment 52 of the switching wire 50 and the outer circumferential surface 70A of the cylindrical part 70 of the gear housing 4A is sufficiently reduced. Thus, the path length of the second wire segment 52 of the switching wire 50 can be shortened. Therefore, the spring constant of the switching wire 50 can be effectively increased to further improve its performance in holding the position of the gear for gear shifting. In this embodiment, the power tool 1 further comprises the gearbox housing 4B, which is provided on the front side of the gearbox housing 4A and to which the front end of the gearbox housing 4A is fixed. The gearbox housing 4A has a plurality of housing attachment parts 72, which are arranged radially outside the switching wire 50, and is fixed to the gearbox housing 4B by the screws 4Q. In the configuration described above, the gearbox housing 4A can be fixed to the gearbox enclosure 4B by the plurality of enclosure attachment parts 72, which are provided separately from the mounting attachment parts 71. Likewise, in this case, the plurality of enclosure attachment parts 72 are arranged radially outside the switching wire 50. Thus, the switching wire 50 does not have to run around the outside of the enclosure attachment parts 72, and an increase in the path length of the switching wire 50 can be avoided. In this embodiment, the housing attachment parts 72 have the third attachments 72A, which are arranged radially outside the second wire segments 52 of the switching wire 50 in the first areas G1. In the configuration described above, in the first areas G1, where the mounting attachment parts 71 are not arranged, an arrangement space for the housing attachment parts 72 (third attachments 72A) can be ensured without rerouting the second wire segments 52 of the switching wire 50. In the embodiment, the third projections 72A have the cutout areas 72C on the outer circumferential area of ​​the same, which is directed towards the radial center of the cylindrical part 70, in order to prevent the switching wire 50 from coming into contact with the third projections 72A. In the configuration described above, the cutout areas 72C are provided at the third projections 72A, which are arranged radially outside the second wire segments 52 of the switching wire 50. This allows the radial positions of the third projections 72A to be brought closer to the second wire segments 52. This can prevent an increase in the dimensions of the outer shape of the gearbox housing 4A, even in a configuration where the third projections 72A are arranged outside the second wire segments 52 of the switching wire 50. In this embodiment, the gearbox housing 4A has a through-hole 4J on each side in a lateral direction. The switching wire 50 has a first wire section 50R and a second wire section 50L. The first wire section 50R has the first wire segment 51, the second wire segment 52, and the third wire segment 53 and is inserted into the through-hole 4J on one side. The second wire section 50L has the first wire segment 51, the second wire segment 52, and the third wire segment 53 and is inserted into the through-hole 4J on the other side. The third projections 72A are arranged on the outside of the second wire segment 52 of the first wire section 50R and on the outside of the second wire segment 52 of the second wire section 50L. In the configuration described above, the third attachments 72A are located on the outside of the second wire segment 52 of the first wire section 50R and on the outside of the second wire segment 52 of the second wire section 50L. This allows the fixing points of the gearbox housing 4A and the gearbox enclosure 4B to be distributed over a wider area. This makes it possible to fix the gearbox housing 4A more evenly. In this embodiment, the speed-changing lever 12 is arranged on the upper side of the gearbox housing 4A. The housing extension parts 72 have the fourth extension 72B, which is located in the second area G2, below the through holes 4J on the outer circumference of the cylindrical part 70. In the configuration described above, by arranging the fourth attachment 72B in the second area G2, where the switching wire 50 is not positioned inside the gearbox housing 4A, a plurality of fixing points for the gearbox housing 4A on the gearbox enclosure 4B can be distributed over a wider circumferential area. Consequently, the third attachments 72A and the fourth attachment 72B can fix the gearbox housing 4A more evenly. In this embodiment, the power tool 1 comprises the motor 6, the output part 8, the speed reduction mechanism 30, the gearbox housing 4A, the motor mount 4C, the speed-changing lever 12 (shifting actuator), and the switching wire 50. The output part 8 is located at the front of the motor 6 and is configured to be driven by the motor 6. The speed reduction mechanism 30 is arranged between the motor 6 and the output part 8 and has a gear-shifting function. The gearbox housing 4A has the cylindrical part 70, which has through-holes 4J extending radially through it, and accommodates the speed reduction mechanism 30 within the cylindrical part 70. The motor mount 4C is arranged between the motor 6 and the speed reduction mechanism 30 and is fixed to the gearbox housing 4A by the screws 4R.The speed-changing lever 12 (shift actuation element) is configured such that, when moved, it causes the speed reduction mechanism 30 to change the gear ratio. The shift wire 50 passes through the through-holes 4J of the gearbox housing 4A and couples the speed-changing lever 12 to the speed reduction mechanism 30. The shift wire 50 has a retained section 50F, which is held by the speed-changing lever 12. The gearbox housing 4A has a first screw fixing element 75, which is positioned radially opposite the retained section 50F of the shift wire 50 when viewed axially, and which secures the motor mount. In the configuration described above, the first screw fixing element 75 for fixing the motor mount 4C is located in the gearbox housing 4A at a position opposite the retained area 50F of the switching wire 50 in the radial direction when viewed in the axial direction. If the first screw fixing element 75 is located midway along the path to the speed reduction mechanism 30, the switching wire 50 runs around the outside of the first screw fixing element 75. In contrast, in the present embodiment, the switching wire 50 can be connected to the speed reduction mechanism 30 via a coupling area without running around the outside of the first screw fixing element 75 from the retained area 50F. This can shorten the path length of the switching wire 50 leading to the speed reduction mechanism 30, thereby increasing the spring constant (stiffness) of the switching wire 50.Increasing the spring constant of the switching wire 50 makes the switching wire 50 less easily bent and allows a gear coupled via the switching wire 50 to be supported even when a reaction force acts on the gear. Consequently, positional displacement of a gear for the gear shifting of the speed reduction mechanism 30 is less likely to occur, resulting in more reliable gear shifting. In this embodiment, the first screw fixing element 75 is provided in the gearbox housing 4A at a location on the opposite region GF, which is radially opposite the switching wire 50 when viewed in the axial direction. The plurality of second screw fixing elements 76, which fix the motor mount 4C, are provided in the gearbox housing 4A in the non-opposite region (second region G2), which is not radially opposite the switching wire 50 when viewed in the axial direction. In the configuration described above, only one first screw fixing element 75 is provided in the opposite area GF, thus eliminating the need for the switching wire 50 to run around the screw fixing elements. The majority of second screw fixing elements 76 are provided in the non-opposite area, thereby fixing the motor mount 4C and the gearbox housing 4A more uniformly to each other at multiple points, while avoiding an increase in the path length of the switching wire 50. In this embodiment, the gearbox housing 4A and the motor mount 4C are fixed to each other at three points arranged in a triangular shape when viewed in the axial direction by a first screw fixing part 75, which is arranged in the opposite area GF, and by two second screw fixing parts 76, which are arranged on one side and the other side in the lateral direction with respect to the center of the gearbox housing 4A in the non-opposite area (second area G2). In the configuration described above, by fixing the motor mount 4C and the gearbox housing 4A at the three points arranged in the triangular shape when viewed in the axial direction, the motor mount 4C and the gearbox housing 4A can be fixed evenly and firmly to each other, while avoiding an extension of the path length of the switching wire 50. In this embodiment, the gearbox housing 4A has a first mating surface 73, which has an annular flat shape, on its rear end surface, opposite the motor mount 4C. The motor mount 4C has a second mating surface 91, which has an annular flat shape and is in contact with the first mating surface 73, on its front surface 90, opposite the gearbox housing 4A. In the configuration described above, the first mating surface 73 of the gearbox housing 4A and the second mating surface 91 of the motor mount 4C both have a flat surface that can be brought into surface contact with each other. This can effectively prevent leakage of lubricant (grease) inside the gearbox housing 4A and the like, even when vibration is generated by driving the motor 6. In this embodiment, the power tool 1 further comprises the gearbox housing 4B, which is provided at the front of the gearbox housing 4A and to which the front end of the gearbox housing 4A is fixed. The gearbox housing 4A has two third screw fixing parts 77, which are arranged at one position in the circumferential direction between the first screw fixing part 75 and the second screw fixing part 76, which is arranged on one side, and at another position in the circumferential direction between the first screw fixing part 75 and the second screw fixing part 76, which is provided on the other side. In the configuration described above, the screw tightening points (third screw fixing parts 77), where the gearbox housing 4A and the gearbox enclosure 4B are screwed together, can be arranged in positions that are offset in a circumferential direction with respect to the screw tightening points (first screw fixing part 75 and second screw fixing parts 76), where the gearbox housing 4A and the motor mount 4C are screwed together. This can improve the machinability of screw tightening operations. In this embodiment, the gearbox housing 4A has a fourth screw fixing element 78, which is arranged between the two second screw fixing elements 76, which are arranged on one side and the other side in the non-opposite region (second region G2). The gearbox housing 4A and the gearbox enclosure 4B are fixed to one another at three points, arranged in an inverted triangular shape when viewed in the axial direction, by the two third screw fixing elements 77 and the fourth screw fixing element 78. In the configuration described above, the motor mount 4C and the gearbox housing 4A are fixed to each other at three points, forming a triangular shape when viewed axially. The gearbox housing 4A and the gearbox enclosure 4B are fixed to each other at three points, arranged in an inverted triangular shape when viewed axially. This allows for a uniform fixing of the motor mount 4C to the gearbox housing 4A and the fixing of the gearbox housing 4A to the gearbox enclosure 4B, and improves the ease of tightening screws for each fixing point. Other embodiments In the embodiment described above, a battery pack 20 is mounted on the battery mounting part 5 and is used as a power source for the power tool 1. A mains power source (AC power source) can also be used as the power source for the power tool 1. Although the embodiment described above shows an example in which the power tool 1 is described as an impact drill, the power tool can be a different power tool than the impact drill. The power tool is not specifically limited as long as it has a speed reduction mechanism that incorporates a gear-shifting function and a structure that couples a shifting actuation element to the speed reduction mechanism using a shift wire. Although the embodiment described above describes an example in which three mounting attachment parts 71 are provided, two, four, or more mounting attachment parts 71 can be provided. Similarly, although the embodiment described above describes an example in which three housing attachment parts 72 are provided, two, four, or more housing attachment parts 72 can be provided. Additional aspect An additional aspect of the present teachings indicates: Aspect A: Power tool comprising a motor, an output part provided at the front of the motor and configured to be driven by the motor, a speed reduction mechanism arranged between the motor and the output part, a gearbox housing accommodating the speed reduction mechanism, and a motor mount arranged between the motor and the speed reduction mechanism and fixed to the gearbox housing, wherein the gearbox housing has a first mating surface having an annular flat shape on a rear end surface opposite the motor mount, and the motor mount has a second mating surface having an annular flat shape in contact with the first mating surface on a front surface opposite the gearbox housing. In the embodiment according to aspect A, the speed reduction mechanism does not need to have the gear shifting function. Therefore, the shift actuator and the shift wire do not need to be provided. Although the invention has been described with regard to a complete and unambiguous disclosure in respect of certain embodiments, the attached claims are not to be regarded as limiting, but are to be interpreted as encompassing all modifications and alternative constructions that a person skilled in the art might consider and which appropriately fall within the basic teaching set forth herein. 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 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 JP 2023 - 89 934 A

[0002]

Claims

Power tool comprising a motor, an output part provided at the front of the motor and configured to be driven by the motor, a speed reduction mechanism arranged between the motor and the output part and having a gear-shifting function, a gearbox housing comprising a cylindrical part having at least one through-hole penetrating therein in a radial direction, and a plurality of mounting parts provided on an outer circumference of the cylindrical part, and accommodating the speed reduction mechanism inside the cylindrical part, a motor mount arranged between the motor and the speed reduction mechanism and fixed to the mounting parts by screws, and a shift actuating part configured to cause the speed reduction mechanism to change the gear ratio by being moved.and a switching wire that passes through the through-hole of the gearbox housing and couples the switching actuation part to the speed reduction mechanism, wherein the switching wire has at least one wire section comprising a first to third wire segment, wherein the first wire segment extends from the switching actuation part to the cylindrical part when viewed in an axial direction, the second wire segment extends in a circumferential direction along an outer circumferential surface of the cylindrical part from one end of the first wire segment, and the third wire segment extends from one end of the second wire segment and is inserted into the through-hole, and the mounting attachment parts are provided at positions on the outer circumferential surface of the cylindrical part other than a first section that is opposite the second wire segment in a radial direction. Power tool according to claim 1, wherein the at least one through-hole has two through-holes provided on one side and another side in a lateral direction of the gearbox housing, the at least one wire section having a first wire section provided on one side and inserted into the through-hole provided on one side, and a second wire section provided on the other side and inserted into the through-hole provided on the other side, and the mounting attachment parts having a first attachment arranged between the first wire segment of the first wire section and the first wire segment of the second wire section. Power tool according to claim 2, wherein the switching actuation part is arranged on the upper side of the gearbox housing, and the mounting attachment parts have at least a second attachment which is arranged in a second area which is located below the through-hole on the outer circumference of the cylindrical part. Power tool according to claim 3, wherein the at least one second projection has two second projections arranged on one side and the other side in the lateral direction of the cylindrical part in the second area. Power tool according to one of claims 1 to 4, wherein a radial distance between the second wire segment of the switching wire and an outer circumferential surface of the cylindrical part in the first area is smaller than a protrusion of the mounting attachment part with respect to the outer circumferential surface in the first area. Power tool according to claim 1, further comprising a gearbox housing which is provided at the front of the gearbox housing and to which a front end of the gearbox housing is fixed, wherein the gearbox housing has a plurality of housing attachment parts which are arranged radially outside the switching wire and are fixed to the gearbox housing by screws. Power tool according to claim 6, wherein the housing attachment parts have at least a third attachment which is arranged radially outside the second wire segment of the switching wire in the first area. Power tool according to claim 7, wherein the third projection has a cutout area on an outer circumferential region of the same, which is opposite a radial center of the cylindrical part, in order to prevent the switching wire from coming into contact with the third projection. Power tool according to claim 7, wherein the at least one through-hole has two through-holes arranged on one side and another side in a lateral direction of the gearbox housing, the at least one wire section having a first wire section arranged on one side and inserted into the through-hole arranged on one side, and a second wire section arranged on the other side and inserted into the through-hole provided on the other side, and the at least one third projection having two third projections arranged on an outside of the second wire segment of the first wire section and an outside of the second wire segment of the second wire section. Power tool according to claim 7, wherein the switching actuation part is arranged on the upper side of the gearbox housing, and the housing attachment parts have a fourth attachment which is arranged in a second area which is located below the through-hole on the outer circumference of the cylindrical part. Power tool comprising a motor, an output part provided at the front of the motor and configured to be driven by the motor, a speed reduction mechanism arranged between the motor and the output part and having a gear-shifting function, a gearbox housing having a cylindrical part having at least one through-hole penetrating it in a radial direction and accommodating the speed reduction mechanism inside the cylindrical part, a motor mount arranged between the motor and the speed reduction mechanism and fixed to the gearbox housing by screws, a shift actuating part configured to cause the speed reduction mechanism to change the gear ratio by being moved, and a shift wire.which passes through the through-hole of the gearbox housing and couples the shift actuating part with the speed reduction mechanism, wherein the shift wire has a held area which is held by the shift actuating part, and the gearbox housing has a first screw fixing part which is provided in a position which is opposite the held area of ​​the shift wire in the radial direction when viewed in an axial direction, and which fixes the motor mount. Power tool according to claim 11, in which the first screw fixing part is provided in the gearbox housing at a location in an area opposite the switching wire in the radial direction when viewed in the axial direction, and a plurality of second screw fixing parts, which fix the motor mount, are provided in the gearbox housing in a non-opposite area that is not opposite the switching wire in the radial direction when viewed in the axial direction. Power tool according to claim 12, wherein the gearbox housing and the motor mount are fixed to one another at three points arranged in a triangular shape when viewed in the axial direction by a first screw fixing part located in the opposite area and two second screw fixing parts located on one side and another side in a lateral direction with respect to a center of the gearbox housing in the non-opposite area. Power tool according to claim 11, wherein the gearbox housing has a first mating surface having an annular flat shape on a rear end surface opposite the motor mount, and the motor mount has a second mating surface having an annular flat shape in contact with the first mating surface on a front surface opposite the gearbox housing. Power tool according to claim 13, further comprising a gearbox housing which is provided at the front of the gearbox housing and to which a front end of the gearbox housing is fixed, wherein the gearbox housing has two third screw fixing parts which are arranged at a position in a circumferential direction between the first screw fixing part and a second screw fixing part which is arranged on one side, and at a position in the circumferential direction between the first screw fixing part and a second screw fixing part which is arranged on the other side. Power tool according to claim 15, wherein the gearbox housing has a fourth screw fixing part arranged between the two second screw fixing parts arranged on one side and on the other side in the non-opposite region, and the gearbox housing and the gearbox enclosure are fixed to one another at three points arranged in an inverted triangular shape when viewed in the axial direction by the two third screw fixing parts and the fourth screw fixing part.

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