Work machine

Abstract

The reliability is improved. In a switching mechanism (60) of a screwdriver drill (1), a shift arm (64) is rotatably attached to an outer peripheral portion of a gearbox (31) with a left-right direction as an axial direction. A ring-side connecting part (64E) is formed on a second arm part (64C) of the shift arm (64), and the ring-side connecting part (64E) is inserted into an opening part (31D) of the gear box (31) and is connected with the second gear ring (44). Moreover, the motor spacer (32) is provided with an arm stopper (66), and the arm stopper (66) covers the ring-side connecting part (64E) from the outer side in the left-right direction, and is disposed with a small gap from the outer side in the left-right direction of the ring-side connecting part (64E). As a result, it is possible to prevent the ring-side connection section (64E) from falling off from the opening (31D) by means of the arm stopper (66).

Description

Technical Field

[0001] The invention relates to a working machine. Background Art

[0002] In the driver drill (working machine) described in Patent Document 1 below, a transmission mechanism composed of a planetary gear mechanism transmits the driving force of the motor to the spindle, and the spindle rotates to perform a tightening process on the workpiece, etc. The planetary gear mechanism of the driver drill is composed of a three-stage planetary gear mechanism unit, and the transmission path of the planetary gear mechanism is switched by the operator's operation to change the rotation speed of the spindle. Specifically, the operator operates the switch of the switching mechanism, so that the second ring of the second-stage planetary gear mechanism unit moves forward and backward, switching to a state that allows the rotation of the second ring or a state that restricts the rotation of the second ring.

[0003] When explaining the switching mechanism, a switching member (not shown) is provided in the housing, and the switch and the second ring are connected by the switching member. The switching member is provided on the outer periphery of the housing accommodating the planetary gear mechanism, and is inserted through an opening formed in the housing to be connected to the second ring.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-245609 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Here, in the above-mentioned driver drill, if the switching member falls off from the opening of the housing, the connection between the switching member and the second ring is released. In addition, if, for example, a lubricant such as grease used in the planetary gear mechanism scatters from the opening of the housing to the outside of the housing, there is a concern that the lubricant may leak from the housing. Therefore, in the above-mentioned case, the reliability of the driver drill is reduced, and therefore, in the above-mentioned driver drill, there is room for improvement in terms of improving reliability.

[0009] In view of the above-mentioned facts, an object of the present invention is to provide a working machine capable of improving reliability.

[0010] Solutions to Solve Problems

[0011] The working machine of one or more embodiments of the present invention comprises: a motor; a transmission mechanism, which transmits the driving force of the above-mentioned motor to the output part to rotate the above-mentioned output part; a shell, which accommodates the above-mentioned transmission mechanism and has an opening part that connects the inside with the outside; a connecting part, which can be movably installed on the outer periphery of the above-mentioned shell, inserted into the above-mentioned opening part and connected to the above-mentioned transmission mechanism; and an anti-detachment part, which covers the above-mentioned connecting part from the opening side of the above-mentioned opening part and prevents the above-mentioned connecting part from falling off from the above-mentioned opening part.

[0012] The operating mechanism of one or more embodiments of the present invention is configured such that the housing is formed into a cylindrical shape, a motor spacer is provided at one end of the housing to block one end of the housing and support the driving shaft of the motor, and the anti-detachment portion is integrated with the motor spacer.

[0013] In one or more embodiments of the working mechanism of the present invention, the motor and the housing are accommodated in a casing, and the anti-detachment portion is integrally formed with the casing.

[0014] The working mechanism of one or more embodiments of the present invention is constituted by a switching component that is rotated to switch the power transmission path of the above-mentioned transmission mechanism, the above-mentioned anti-slip portion is arranged adjacent to the outer peripheral surface of the above-mentioned shell, and a recessed portion for accommodating a part of the above-mentioned switching component is formed on the surface of the above-mentioned anti-slip portion adjacent to the above-mentioned shell.

[0015] The effects of the invention are as follows.

[0016] According to one or more embodiments of the present invention, reliability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a longitudinal sectional view which shows the driver drill of this embodiment.

[0018] Figure 2 It is shown in an enlarged manner Figure 1 A longitudinal sectional view of the driving force transmission mechanism shown.

[0019] Figure 3 yes Figure 2 The gearbox is shown in a perspective view as seen from the oblique front left.

[0020] Figure 4 It is shown Figure 2 The shift arm is shown in its entirety in a rear view as viewed from the rear side.

[0021] Figure 5 It is shown Figure 4 The shift arm is shown in a side view from the right side in an assembled state in which the shift arm is assembled to the gear case.

[0022] Figure 6 It shows that Figure 5 The illustrated example is a cross-sectional view of an arm stopper formed on a housing as viewed from the rear side. DETAILED DESCRIPTION

[0023] Hereinafter, the driver drill 1 as a working machine of the present embodiment will be described using the accompanying drawings. In addition, arrows UP, FR, and RH appropriately shown in the accompanying drawings respectively indicate the upper side, the front side, and the right side of the driver drill 1. In the following description, when the up-down, front-back, and left-right directions are used for description, the up-down direction, the front-back direction, and the left-right direction of the driver drill 1 are indicated unless otherwise specified.

[0024] like Figure 1 As shown, the driver drill 1 is configured as an electric tool, that is, a tip tool is mounted on a chuck 35 provided at the tip end of the driver drill 1, and a rotational force is applied to the tip tool to perform tightening processing and the like.

[0025] The driver drill 1 is configured to include a housing 10 constituting the outer shell of the driver drill 1, a motor 20 housed in the housing 10, and a driving force transmission mechanism 30 that transmits the driving force of the motor 20 to the spindle 33. In addition, the driver drill 1 has a switching mechanism 60 for switching the driving transmission path of the speed reduction mechanism 40 in the driving force transmission mechanism 30. Hereinafter, each structure of the driver drill 1 will be described.

[0026] (About the housing 10) When viewed from the right side, the housing 10 is formed into a hollow, substantially I-shaped shape. Specifically, the housing 10 is configured to include an upper housing portion 10A that constitutes the upper end of the housing 10 and extends in the front-to-back direction, a handle portion 10B that extends downward from the middle portion in the front-to-back direction of the upper housing portion 10A, and a lower housing portion 10C that constitutes the lower end of the housing 10. In addition, the housing 10 is composed of a plurality of housing components, and the housing 10 is formed by assembling the above-mentioned housing components to each other.

[0027] A trigger 12 is provided at the upper end of the handle portion 10B. The trigger 12 is configured to protrude from the handle portion 10B to the front side and can be pulled to the rear side. A switch mechanism 14 is provided at the handle portion 10B and at the rear side of the trigger 12. The switch mechanism 14 has a switch (not shown), and the trigger 12 is pulled to switch the switch from off to on.

[0028] The lower housing portion 10C is provided with a controller 16. The switch of the switch mechanism 14 is electrically connected to the controller 16, and an output signal corresponding to the operation state of the trigger 12 is output from the switch to the controller 16. In addition, a battery 18 is detachably mounted on the lower housing portion 10C. The battery 18 is electrically connected to the controller 16, and the battery 18 supplies power to the motor 20.

[0029] (Regarding the motor 20) The motor 20 is housed in the rear end portion of the upper housing portion 10A and is electrically connected to the controller 16. The motor 20 is configured to include a drive shaft 21 having an axial direction in the forward and backward directions, a rotor 22 connected to the drive shaft 21 so as to be rotatable as a whole, and a substantially cylindrical stator 23 disposed radially outside the rotor 22.

[0030] The rear end of the drive shaft 21 is rotatably supported by a rear motor bearing 24 fixed to the housing 10. On the other hand, the front end of the drive shaft 21 is rotatably supported by a front motor bearing 25 fixed to a motor spacer 32. The motor spacer 32 is formed in a substantially circular plate shape with the front-to-rear direction being the plate thickness direction, and is mounted on the rear end of a gear box 31 described below. The front end of the drive shaft 21 protrudes to the front side of the motor spacer 32 and is arranged in the gear box 31. A pinion 21A is provided at the front end of the drive shaft 21.

[0031] (Regarding the driving force transmission mechanism 30) Figure 1 and Figure 2 As shown, the driving force transmission mechanism 30 is constructed to include a gear box 31 as a shell constituting the outer contour of the driving force transmission mechanism 30, a reduction mechanism 40 as a transmission mechanism for transmitting the driving force of the motor 20 to the main shaft 33, and a clutch mechanism 50 for cutting off the drive transmission to the main shaft 33 when the transmission torque transmitted to the main shaft 33 reaches an upper limit value.

[0032] (Regarding the gear box 31) Figure 3 As shown, the gear box 31 is formed into a roughly cylindrical shape with a step having an axial direction in the front-to-rear direction, and the diameter of the front part of the gear box 31 is set to be smaller than the diameter of the rear part of the gear box 31. The gear box 31 is housed in the front part of the upper housing part 10A. The above-mentioned motor spacer 32 is embedded in the rear end part of the gear box 31, and the rear end part of the gear box 31 is blocked by the motor spacer 32. A main shaft 33 as an output part having an axial direction in the front-to-rear direction is provided at the front part of the gear box 31, and the main shaft 33 and the driving shaft 21 of the motor 20 are arranged on the same axis. The front end side part of the main shaft 33 is supported by a bearing 34 provided at the front end part of the gear box 31 so as to be rotatable. A chuck 35 is connected to the front end part of the main shaft 33, and the driving force from the motor 20 is transmitted to the front end tool assembled on the chuck 35.

[0033] A threaded portion 31A composed of an external thread is formed on the outer peripheral portion of the front portion of the front portion of the gear box 31, and a nut 51 of the clutch mechanism 50 described below is threadedly engaged with the threaded portion 31A. In addition, a clutch dial 36 is provided on the radially outer side of the front portion of the gear box 31. The clutch dial 36 is formed in a substantially cylindrical shape that is open to the rear side, and is rotatably connected to the gear box 31 via the nut 51 described below. An insertion hole 36A is formed through the front wall of the clutch dial 36, and the front end of the main shaft 33 protrudes to the front side from the insertion hole 36A.

[0034] (Regarding the speed reduction mechanism 40) Figure 2 As shown, the reduction mechanism 40 is housed in the rear part of the gear box 31. The reduction mechanism 40 is composed of a three-stage planetary gear mechanism. The first-stage planetary gear mechanism in the reduction mechanism 40 has an annular first ring gear 41, which is arranged on the radially outer side of the pinion 21A of the motor 20 and is connected to the gear box 31 in a non-rotatable manner. Internal teeth are formed on the inner circumference of the first ring gear 41. A plurality of first planetary gears 42 are provided between the internal teeth and the pinion 21A, and the first planetary gears 42 are meshed with the pinion 21A and the first ring gear 41. A first disk-shaped first planetary gear carrier 43 is provided on the front side of the pinion 21A, and the first planetary gears 42 are supported by the first planetary gear carrier 43 so as to be rotatable. That is, the pinion 21A is configured as a sun gear. A sun gear 43A protruding toward the front side is formed in the central part of the first planetary gear carrier 43.

[0035] The second-stage planetary gear mechanism in the speed reduction mechanism 40 has an annular second ring gear 44, which is connected to the radially outer side of the sun gear 43A. The second ring gear 44 is configured to be relatively movable in the front-rear direction relative to the gear box 31. Specifically, it is configured to be able to rotate in the rotation limit position ( Figure 2 The second ring gear 44 is configured to move between the rotation limiting position (shown in the figure) and the rotation allowing position (not shown) after moving backward from the rotation limiting position. In the rotation limiting position of the second ring gear 44, the second ring gear 44 and the gear box 31 are connected in a manner that cannot rotate relative to each other. On the other hand, in the rotation allowing position of the second ring gear 44, the second ring gear 44 and the gear box 31 are connected in a manner that can rotate relative to each other. The second ring gear 44 is switched to the rotation limiting position or the rotation allowing position by the switching mechanism 60 described below. An engaging groove 44A is formed on the outer periphery of the second ring gear 44, which is open radially outward and extends in the circumferential direction, and the engaging groove 44A is formed over the entire circumference of the second ring gear 44.

[0036] Internal teeth are formed on the inner circumference of the second ring gear 44. A plurality of second planetary gears 45 are provided between the internal teeth and the sun gear 43A, and the second planetary gears 45 mesh with the sun gear 43A and the second ring gear 44. A disk-shaped second planetary gear carrier 46 is provided on the front side of the sun gear 43A, and the second planetary gears 45 are rotatably supported by the second planetary gear carrier 46. A sun gear 46A protruding toward the front side is formed in the center of the second planetary gear carrier 46.

[0037] The third-stage planetary gear mechanism in the speed reduction mechanism 40 has an annular third ring gear 47, which is arranged radially outside the sun gear 46A and supported by the gear box 31 so as to be rotatable. A plurality of engaging protrusions 47A are formed on the front surface of the third ring gear 47. The engaging protrusions 47A engage with the clutch mechanism 50 described below, and the third ring gear 47 is supported by the clutch mechanism 50 so as to be non-rotatable. Internal teeth are formed on the inner circumference of the third ring gear 47. A third planetary gear 48 is provided between the internal teeth and the sun gear 46A, and the third planetary gear 48 meshes with the sun gear 46A and the third ring gear 47. A disc-shaped third planetary gear carrier 49 is provided on the front side of the sun gear 46A, and the third planetary gear 48 is supported by the third planetary gear carrier 49 so as to be rotatable. A fitting hole 49A is formed through the central portion of the third planetary gear carrier 49. Moreover, the rear end portion of the main shaft 33 is connected to the fitting hole 49A in a non-rotatable manner. In summary, the rotational force of the motor 20 is transmitted by the speed reduction mechanism 40 , so that the main shaft 33 rotates.

[0038] That is, as described above, in the rotation limiting position of the second ring gear 44, the rotation of the second ring gear 44 is limited, and thus the rotation of the first planetary gear carrier 43 is transmitted to the third planetary gear carrier 49 and the main shaft 33 by the second-stage planetary gear mechanism with deceleration. That is, the main shaft 33 and the front end tool rotate at a low speed and a high torque. On the other hand, in the rotation allowing position of the second ring gear 44, the rotation of the second ring gear 44 is allowed, and thus the second ring gear 44 rotates together with the first planetary gear carrier 43 and the second planetary gear carrier 46. Therefore, the rotation of the first planetary gear carrier 43 is not decelerated by the second-stage planetary gear mechanism, and the main shaft 33 and the front end tool rotate at a high speed and a low torque.

[0039] (Regarding the clutch mechanism 50) Figure 2As shown in FIG. 1 , the clutch mechanism 50 is configured to include a nut 51, a thrust plate 52, a clutch spring 53, and a plurality of balls 54. The nut 51 is formed into a substantially cylindrical shape with the front-to-rear direction as the axial direction. A threaded portion 51A is provided on the inner circumference of the nut 51, and an internal thread is formed on the threaded portion 51A. The nut 51 is externally inserted into the front portion of the gear box 31, and the threaded portion 51A is threadedly engaged with the threaded portion 31A of the gear box 31. In addition, a flange portion 51B protruding radially outward is formed at the front end portion of the nut 51, and the flange portion 51B is arranged close to the radial inner side of the clutch dial 36, and is connected to the clutch dial 36 in a manner that can rotate integrally and relatively rotate in the front-to-rear direction. Therefore, when the clutch dial 36 is rotated by the operator, the nut 51 rotates relative to the gear box 31 together with the clutch dial 36. In addition, at this time, due to the threaded engagement of the nut 51 with the gear box 31, the nut 51 moves relative to the gear box 31 and the clutch dial 36 in the front-to-rear direction. Specifically, the nut 51 is configured to be able to Figure 2 The position shown on the upper side of the main shaft 33) and the approach position after moving backward from the separation position (in Figure 2 The spindle 33 is movable between the positions shown on the lower side thereof.

[0040] The thrust plate 52 is formed in a substantially annular plate shape with the front-rear direction being the plate thickness direction. The thrust plate 52 is externally inserted into the front portion of the gear case 31 and is located at the rear end of the front portion. The clutch spring 53 is configured as a compression coil spring. The clutch spring 53 is externally inserted into the nut 51, the front end of the clutch spring 53 is engaged with the flange portion 51B, and the rear end of the clutch spring 53 is engaged with the thrust plate 52. Thus, the clutch spring 53 applies force to the thrust plate 52 toward the rear side.

[0041] The ball 54 is inserted into the gear housing 31 through a ball hole 31B (see Figure 3 ) is inserted into the rear part of the gear case 31 and is arranged between the thrust plate 52 and the third ring gear 47. As a result, the force of the clutch spring 53 is transmitted to the ball 54 via the thrust plate 52, and the ball 54 presses the third ring gear 47 to the rear. Moreover, when the speed reduction mechanism 40 is in operation, the engaging protrusion 47A of the third ring gear 47 engages with the ball 54, so that the third ring gear 47 is held non-rotatable, and the driving force of the motor 20 is transmitted to the main shaft 33. On the other hand, when the torque transmitted to the main shaft 33 reaches the upper limit value during the tightening operation, the ball 54 pressed by the engaging protrusion 47A of the third ring gear 47 overcomes the force of the clutch spring 53 and moves forward together with the thrust plate 52, so that the ball 54 passes over the engaging protrusion 47A. As a result, the third ring gear 47 rotates, and the drive transmission to the main shaft 33 is cut off.

[0042] Furthermore, the clutch dial 36 is rotated to move the nut 51 from the disengaged position to the rear side (closed position side), thereby increasing the amount of compression deformation of the clutch spring 53 and increasing the force of the clutch spring 53. Therefore, the clutch dial 36 is rotated to change the upper limit of the torque transmitted to the spindle 33 during the tightening operation. In addition, at the close position of the nut 51, the rear end of the nut 51 abuts against the thrust plate 52 from the front side. Therefore, the movement of the thrust plate 52 to the front side is restricted, and the clutch mechanism 50 is set to the non-operating state.

[0043] (About the switching mechanism 60) The switching mechanism 60 switches the position of the second ring gear 44 of the speed reduction mechanism 40 to the rotation restriction position or the rotation permission position, and is configured as a mechanism part for changing the drive transmission path of the speed reduction mechanism 40. Figure 2 , Figure 4 and Figure 5 As shown in FIG. 1 , the switching mechanism 60 is configured to include an operation button 62 (in a broad sense, an element grasped as a switching operation portion), a shift arm 64 as a switching member, and an arm stopper 66 as a disengagement prevention portion for maintaining the assembled state of the shift arm 64. The shift arm 64 is assembled to the outer peripheral portion of the gear case 31, and connects the operation button 62 to the second ring gear 44. Therefore, first, the assembly portion of the shift arm 64 in the gear case 31 is described, and then the various structures of the switching mechanism 60 are described.

[0044] like Figure 3 and Figure 5 As shown, a pair of left and right mounting bosses 31C are formed on the outer periphery of the rear end side portion of the gear box 31 at positions corresponding to the second gear ring 44. The mounting boss 31C is formed in a substantially cylindrical shape with the left and right direction as the axial direction, and protrudes outward in the left and right direction from the outer periphery of the gear box 31. The mounting boss 31C is arranged at a position higher than the axis of the gear box 31. A pair of left and right openings 31D are formed through the outer periphery of the gear box 31 and below the mounting boss 31C, and the inside and outside of the gear box 31 are connected by the openings 31D. In addition, the upper and lower positions of the openings 31D are substantially consistent with the axis of the gear box 31, and the openings 31D are arranged radially outward of the engaging groove 44A of the second gear ring 44. The openings 31D are formed in a substantially long hole shape with the front-to-back direction as the length direction, and the length of the openings 31D in the front-to-back direction is set so that the openings 31D are located radially outward of the engaging groove 44A that moves between the rotation restriction position and the rotation permission position.

[0045] like Figure 1 and Figure 2As shown in FIG. 1 , the operating button 62 is formed in a substantially rectangular strip shape with the thickness direction being the up-down direction and the length direction being the front-to-back direction. The operating button 62 is disposed on the upper side of the rear end portion of the gear box 31 and is connected to the upper housing portion 10A in a manner that allows sliding in the front-to-back direction. Specifically, the operating button 62 is configured to be able to be moved in the low speed position ( Figure 1 and Figure 2 The operating button 62 slides between a low-speed position (shown in the figure) and a high-speed position (not shown) after sliding from the low-speed position to the front side. Moreover, the low-speed position of the operating button 62 corresponds to the rotation-restricted position of the second gear ring 44, and the high-speed position of the operating button 62 corresponds to the rotation-permitted position of the second gear ring 44. A handle portion 62A for operating the operating button 62 is formed in the middle portion in the front-to-back direction of the operating button 62. The handle portion 62A protrudes upward relative to the operating button 62 and is exposed to the upper side of the upper housing portion 10A so as to be operable. A button groove portion 62B that is open to the downward side is formed in the front end side portion of the lower surface of the operating button 62. The button groove portion 62B extends in the left-right direction and penetrates in the left-right direction.

[0046] like Figure 2 , Figure 4 and Figure 5 As shown, the shift arm 64 is made of a wire having elasticity, and is formed into a generally inverted U-shape that is open to the lower side when viewed from the rear side. Specifically, the shift arm 64 is configured to include a button-side connecting portion 64A extending in the left-right direction, a pair of left and right first arm portions 64B extending in a direction inclined downward as the two ends in the length direction of the button-side connecting portion 64A are directed toward the left-right direction outer side, and a pair of left and right second arm portions 64C extending downward from the lower end of the first arm portion 64B. A support portion 64D that is wound in a generally circular shape when viewed from the left-right direction is formed at the upper end of the second arm portion 64C. Furthermore, the shift arm 64 is configured to be embedded in the upper portion of the gear box 31 from the upper side, the mounting boss 31C of the gear box 31 is inserted into the support portion 64D, and the shift arm 64 is supported by the mounting boss 31C to be rotatable. That is, the shift arm 64 is supported on the outer periphery of the gear box 31 so as to be rotatable with the left-right direction as the axial direction.

[0047] The button-side connecting portion 64A is inserted into the button groove portion 62B of the operating button 62 and engages with the operating button 62 in the front-to-back direction. As a result, the shift arm 64 rotates around the axis of the mounting boss 31C in conjunction with the sliding movement of the operating button 62 in the front-to-back direction and is arranged in the low speed position ( Figure 5 The solid line position) or high speed position ( Figure 5The position indicated by the double-dotted line of the second arm portion 64C). A ring-side connecting portion 64E is formed at the lower end of the second arm portion 64C as a connecting portion that is bent inward in the left-right direction. The ring-side connecting portion 64E is inserted into the opening portion 31D of the gear case 31 so as to be movable in the front-back direction. The front end portion of the ring-side connecting portion 64E protrudes from the opening portion 31D into the gear case 31 and is inserted into the engaging groove 44A of the second ring gear 44, and the ring-side connecting portion 64E engages with the second ring gear 44 in the front-back direction. Thus, the operating button 62 and the second ring gear 44 are connected by the shift arm 64, and the second ring gear 44 is switched to the rotation-restricted position or the rotation-allowed position by the operator by sliding the operating button 62.

[0048] like Figure 5 As shown in FIG. 1 , the arm stopper 66 is provided on the left-right outer side of the second arm portion 64C of the shift arm 64. The arm stopper 66 is formed into a substantially rectangular plate shape with the left-right direction as the plate thickness direction and the front-back direction as the length direction, and the rear end of the arm stopper 66 is connected to the outer peripheral portion of the motor spacer 32. That is, the arm stopper 66 is formed integrally with the motor spacer 32. The arm stopper 66 is arranged adjacent to the left-right outer side of the lower end portion of the second arm portion 64C of the shift arm 64 with a slight gap. That is, the arm stopper 66 covers the lower end portion of the second arm portion 64C from the opening side of the opening portion 31D of the gear case 31. And the outer shape of the arm stopper 66 is set so that the arm stopper 66 covers the entire opening portion 31D when viewed from the left-right outer side. That is, the arm stopper 66 is set to cover the lower end portion of the second arm portion 64C within the rotation range of the lower end portion of the second arm portion 64C. The inner side surface of the arm stopper 66 (the surface facing the outer peripheral surface of the gear case 31 ) is disposed away from the outer peripheral surface of the gear case 31 in the left-right direction outward so as to allow the rotation of the operation knob 62 .

[0049] (Function and Effect) Next, the function and effect of this embodiment will be described.

[0050] In the driver drill 1 constructed as above, when the motor 20 is driven by the operator pulling the trigger 12, the driving force of the motor 20 is transmitted to the spindle 33 by the reduction mechanism 40, and the front end tool rotates together with the spindle 33. And, when the torque transmitted to the spindle 33 reaches the upper limit value, the clutch mechanism 50 is operated to cut off the drive transmission to the spindle 33. Specifically, the third ring gear 47 of the reduction mechanism 40 overcomes the force of the clutch spring 53 and rotates relative to the ball 54. Thus, the drive transmission to the spindle 33 is cut off. In addition, the clutch dial 36 is rotated to move the nut 51 to the rear side, so that the compression deformation amount of the clutch spring 53 increases. Thus, the upper limit value of the torque transmitted to the spindle 33 can be changed by the operator.

[0051] Furthermore, the operator operates the operating button 62 of the switching mechanism 60, thereby switching the drive transmission path of the reduction mechanism 40, and the rotational torque of the front end tool is set to low torque or high torque. As a result, in tightening operations, the rotational torque of the front end tool can be switched to low torque or high torque according to the content of the operation. Specifically, the operating button 62 is located in the low speed position, and the second ring gear 44 is configured in the rotation restriction position by the shift arm 64, and the rotational torque of the front end tool becomes high torque. On the other hand, the operating button 62 is located in the high speed position, and the second ring gear 44 is configured in the rotation permission position by the shift arm 64, and the rotational torque of the front end tool becomes low torque.

[0052] Here, in the switching mechanism 60 for switching the drive transmission path of the speed reduction mechanism 40, the shift arm 64 is rotatably mounted on the outer peripheral portion of the gear case 31 with the left-right direction as the axial direction. The second arm portion 64C of the shift arm 64 is formed with a ring-side connecting portion 64E, and the ring-side connecting portion 64E is inserted through the opening portion 31D of the gear case 31 and inserted into the engaging groove 44A of the second ring gear 44 of the speed reduction mechanism 40. Thus, the ring-side connecting portion 64E and the second ring gear 44 are connected by the shift arm 64. In addition, the arm stopper 66 is provided on the motor spacer 32 that blocks the rear end portion of the gear case 31. The arm stopper 66 covers the ring-side connecting portion 64E from the left-right outer side and is arranged with a small gap from the left-right outer side of the ring-side connecting portion 64E. Therefore, the displacement of the ring-side connecting portion 64E to the left-right outer side (opening side of the opening portion 31D) is restricted by the arm stopper 66. Thus, the ring-side connecting portion 64E can be prevented from falling off from the opening 31D by the arm stopper 66. In addition, the lubricant such as grease in the gear case 31 can be prevented from scattering from the opening 31D by the arm stopper 66. As a result, the lubricant such as grease can be prevented from leaking from the housing 10. As a result, the reliability of the driver drill 1 can be improved.

[0053] Furthermore, as described above, the lower end of the second arm portion 64C in the shift arm 64 is covered from the left-right outer side by the arm stopper 66. That is, the arm stopper 66 also functions as a protective member for protecting the second arm portion 64C. Thus, for example, when assembling the housing 10, even if a worker touches the shift arm 64, it is possible to prevent the ring-side connecting portion 64E of the shift arm 64 from falling off from the opening portion 31D of the gear case 31. Therefore, the assemblability of the driver drill 1 can be improved.

[0054] Furthermore, as described above, the arm stopper 66 is formed integrally with the motor spacer 32. Thus, the arm stopper 66 can be provided by effectively utilizing the motor spacer 32 for supporting the drive shaft 21 of the motor 20. Therefore, the number of components of the driver drill 1 can be reduced, and the cost can be reduced.

[0055] Furthermore, in the present embodiment, the arm stopper 66 is formed into a substantially rectangular plate shape with the left-right direction as the plate thickness direction and extending in the front-to-back direction, and is disposed separately from the left-right outer side of the gear box 31. In other words, a predetermined gap for disposing the second arm portion 64C of the shift arm 64 is formed between the arm stopper 66 and the outer peripheral portion of the gear box 31. Alternatively, the arm stopper 66 may be configured to be disposed adjacent to the radial outer side of the gear box 31. That is, the plate thickness of the arm stopper 66 may be made thicker than that of the present embodiment, and a recessed portion 66A (see FIG. 2A ) for accommodating the shift arm 64 may be formed on the inner side surface (the surface opposite to the gear box 31) of the arm stopper 66. Figure 5 In this case, for example, even if the arm stopper 66 is deformed inwardly in the left-right direction due to aging or the like, the inner side surface of the arm stopper 66 abuts against the outer peripheral surface of the gear case 31, so that the arm stopper 66 is prevented from contacting the second arm portion 64C of the shift arm 64. Therefore, the movement of the shift arm 64 can be well maintained. Furthermore, since the portion other than the recessed portion 66A in the arm stopper 66 is arranged adjacent to the outer peripheral surface of the gear case 31, the lubricant such as grease leaking from the opening 31D into the recessed portion 66A can be prevented from flowing down between the gear case 31 and the arm stopper 66. In summary, the reliability of the driver drill 1 can be further improved.

[0056] Furthermore, in the present embodiment, the arm stopper 66 and the motor spacer 32 are integrally formed, but the arm stopper 66 and the motor spacer 32 may be separately formed and fixed to the motor spacer 32 to form the arm stopper 66 and the motor spacer 32 integrally formed.

[0057] Furthermore, the arm stopper 66 may be provided on a member other than the motor spacer 32. Figure 6 As shown, the arm stopper 66 is integrally formed on the inner peripheral surface of the upper housing portion 10A, and is disposed adjacent to the left-right outer side of the second arm portion 64C of the shift arm 64 .

[0058] Explanation of symbols

[0059] 1—driver drill (operating machine), 10—housing, 20—motor, 31—gear box (housing), 31D—opening portion, 32—motor spacer, 33—spindle (output portion), 40—reduction mechanism (transmission mechanism), 64—shift arm (switching component), 64E—ring side connecting portion (connecting portion), 66—arm stopper (anti-slip portion), 66A—recess.

Claims

1. A working machine, characterized in that: have: motor; a transmission mechanism that transmits the driving force of the motor to the output portion to rotate the output portion; a housing that accommodates the transmission mechanism and has an opening that connects the interior with the exterior; a connecting portion that can be movably mounted on the outer periphery of the housing, is inserted through the opening, and is connected to the transmission mechanism; and The cover extends from the housing toward the opening and covers at least a portion of the opening.

2. The working machine according to claim 1, characterized in that: The housing is formed in a cylindrical shape, and a motor spacer is provided at one end of the housing to close the one end of the housing and support the driving shaft of the motor. The cover portion is integrally formed with the motor spacer.

3. The working machine according to claim 1, characterized in that: The motor and the housing are accommodated in a casing. The cover is integrated with the housing.

4. The working machine according to claim 1 or 2, characterized in that: The cover is arranged adjacent to the outer peripheral surface of the housing. A recessed portion for accommodating a part of the connecting portion is formed on a surface of the cover portion adjacent to the housing.

5. The working machine according to claim 1, characterized in that: The connecting portion has a front end portion inserted into the opening portion. The cover portion covers the front end portion.

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