Work machine

Abstract

The present invention realizes an efficient dustproof structure. In a grinder 10, a switch holding part 30 is provided to a motor housing 24 in a housing 20. A switch cover 70 is assembled to the switch holding part 30. A switch 62 is covered with the switch holding part 30 and the switch cover 70. Accordingly, dustproof properties of the switch 62 can be improved. In addition, the switch cover 70 has a capacitor storing and holding part 72L. A capacitor 80 electrically connected to the switch 62 is stored and held in the capacitor storing and holding part 72L. Accordingly, the capacitor 80 connected to the switch 62 can be held by using the switch cover 70 for improving dustproof properties of the switch 62. As a result, an efficient dustproof structure can be realized for the switch 62.

Description

Work equipment

[0001] The present invention relates to a work machine.

[0002] In the grinder (working machine) described in Patent Document 1 below, sliding an operating section switches a switch in the housing from an off state to an on state, driving a motor, which rotates a grinding wheel attached to the tip of the grinder, allowing the grinder to perform grinding or other processing on a workpiece.

[0003] JP 2018-171680 A

[0004] In a work machine such as a grinder, dust generated during operation can enter the machine and adhere to the switch. Covering the switch can improve the dustproof performance of the switch, but it is desirable for the work machine to have an efficient dustproof structure.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a work machine that can realize an efficient dustproof structure.

[0006] One or more embodiments of the present invention are a work machine comprising: a motor; a switch arranged on one side of the motor in a first direction and switching between an on state that drives the motor and an off state that stops the motor; a housing having a motor accommodating portion that accommodates the motor; and a switch holding portion that holds the switch; and a switch cover provided on the switch holding portion that covers the switch together with the switch holding portion, wherein the switch cover has a first component holding portion that holds a first electronic component.

[0007] In one or more embodiments of the present invention, the first component holder is formed on an outer periphery of the switch cover.

[0008] One or more embodiments of the present invention are a work machine in which the switch holding portion is provided with a second component holding portion that accommodates a second electronic component, and the second electronic component is covered by the switch cover and held in the switch holding portion.

[0009] In one or more embodiments of the present invention, the switch holding portion has a switch accommodating portion that is open to one side in a second direction perpendicular to the first direction and that accommodates the switch, the second component holding portion that is open to one side in the second direction, and a partition wall that separates an opening between the switch accommodating portion and the second component holding portion and that protrudes further to one side in the second direction than the switch accommodating portion and the second component holding portion, and the switch cover covers the switch accommodating portion and the second component holding portion from one side in the second direction and has a fitting groove portion into which the partition wall is fitted.

[0010] One or more embodiments of the present invention are a work machine in which a stepped recess is formed on the outer periphery of the edge of the opening of the switch accommodating section, and the switch cover is provided with an insertion piece that is inserted into the stepped recess.

[0011] One or more embodiments of the present invention are directed to a work machine in which the switch is sandwiched between the switch accommodating portion and the switch cover in the second direction.

[0012] One or more embodiments of the present invention are a work machine in which a pair of wiring terminals for supplying power to the switch are connected to the switch, one of the terminals being covered by the switch holding portion and the other terminal being covered by the switch cover.

[0013] One or more embodiments of the present invention are a work machine in which a pair of wiring terminals for supplying power to the switch are connected to the switch, and the pair of terminals are covered by the switch holding portion or the switch cover.

[0014] In one or more embodiments of the present invention, the switch is provided with a partition that separates the pair of terminals from one another.

[0015] One or more embodiments of the present invention are a work machine in which a rotational speed adjusting device that sets the rotational speed of a motor is operably exposed from the housing, and the rotational speed adjusting device is held by the switch cover.

[0016] In one or more embodiments of the present invention, the switch cover is a work machine configured to include a first cover portion that covers the switch and has the first component holding portion, and a second cover portion that holds the rotational speed adjustment device and covers the plunger of the switch from one side in a second direction perpendicular to the first direction.

[0017] One or more embodiments of the present invention are directed to a work machine in which the switch cover is fastened and fixed to the switch holding portion.

[0018] According to one or more embodiments of the present invention, an efficient dust-proof structure can be achieved.

[0019] 5 is a side view of the disc grinder according to the present embodiment, as seen from the left side. It is a cross-sectional view of the interior of the disc grinder shown in FIG. 1, as seen from the left side. It is a perspective view of the periphery of the switch mechanism with the tail cover shown in FIG. 1 removed, as seen from the rear diagonally rear side. It is a two-sided view of the switch mechanism shown in FIG. 3, as seen from the left and right sides. It is a bottom view of the switch mechanism shown in FIG. 3, as seen from the bottom side. It is an exploded perspective view of the switch mechanism shown in FIG. 3. It is a cross-sectional view (cross-sectional view taken along line 7-7 in FIG. 5) as seen from the rear side, as seen from the left ...

[0020] Hereinafter, a disc grinder 10 (hereinafter simply referred to as grinder 10) as a work machine according to this embodiment will be described with reference to the drawings. Note that arrows UP, FR, and LH, as appropriate, in the drawings indicate the upper side, front side, and left side of the grinder 10, respectively. In the following description, when the up-down, front-rear, and left-right directions are used, they refer to the up-down direction, front-rear direction, and left-right direction of the grinder 10 unless otherwise specified. Furthermore, the front-rear direction corresponds to the first direction in the present invention, the up-down direction corresponds to the second direction in the present invention, and the left-right direction corresponds to the third direction in the present invention.

[0021] The grinder 10 is configured as an electric tool for performing grinding or the like on a workpiece. As shown in Figures 1 and 2, the grinder 10 includes a housing 20, a motor 50, and a switch mechanism 60. Each component of the grinder 10 will be described below.

[0022] (Regarding the housing 20) The housing 20 forms the outer shell of the grinder 10. The housing 20 is formed as a hollow column extending in the front-to-rear direction as a whole. The housing 20 includes a tail cover 22 serving as a cover housing that forms the outer periphery of the rear end of the grinder 10, a motor housing 24 that extends in the front-to-rear direction, and a gear housing 40 that is disposed in front of the motor housing 24.

[0023] (Regarding the tail cover 22) The tail cover 22 is formed in a generally cylindrical shape with a bottom that is open to the front. A power cord 90 is provided at the rear end of the tail cover 22 and extends rearward from the tail cover 22. The power cord 90 supplies external commercial power to a motor 50 and a switch 62, which will be described later. A plurality of air intake ports 22A are formed through the rear end of the tail cover 22. The tail cover 22 accommodates the rear end of a motor accommodating portion 26 of a motor housing 24, which will be described later, and a switch holder portion 30, and is fastened and fixed to the switch holder portion 30.

[0024] (Regarding the motor housing 24) The motor housing 24 is configured to include a motor accommodating portion 26 for accommodating the motor 50, and a switch holder portion 30 serving as a switch holding portion for holding the switch 62. The motor housing 24 is configured as a single, indivisible member.

[0025] The motor accommodating portion 26 constitutes the front portion of the motor housing 24 and is formed in a generally stepped, bottomed, cylindrical shape that is open to the front. A fan accommodating portion 26A is formed at the front end of the motor accommodating portion 26, extending radially outward. The fan accommodating portion 26A is generally rectangular in front view. The motor accommodating portion 26 has a bearing fixing portion 26B at its rear end, which is generally cylindrical and bottomed and open to the front. The upper and lower ends of the bearing fixing portion 26B are connected to the outer periphery of the rear portion of the motor accommodating portion 26 by connecting pieces 26C (see FIGS. 3 and 6 ). The front end of the switch holder portion 30 (described later) is connected to the bearing fixing portion 26B, and the interior of the bearing fixing portion 26B is formed in a stepped, recessed shape that is open to the front so as to fit into the front end of the switch holder portion 30.

[0026] A switch lever 12 (see FIG. 1 ) is provided on the left side of the motor housing 26. The switch lever 12 is connected to the motor housing 26 so as to be slidable in the front-rear direction. Specifically, the switch lever 12 is disposed in the OFF position shown in FIG. 1 and is configured to slide forward from the OFF position by an operator. A slide bar 14 (see FIG. 6 ) is connected to the switch lever 12, and the slide bar 14 switches a switch 62 (described below) from an OFF state to an ON state. The slide bar 14 is housed inside the motor housing 24 and is formed in a generally elongated plate shape extending in the front-rear direction. The front end of the slide bar 14 is connected to the switch lever 12. The slide bar 14 slides in the front-rear direction in conjunction with the sliding of the switch lever 12. Note that FIG. 6 only illustrates the rear portion of the slide bar 14.

[0027] As shown in FIGS. 2 to 8 , the switch holder portion 30 is formed in a generally upwardly open recessed shape and extends rearward from the bearing fixing portion 26B. The switch holder portion 30 constitutes the framework of the switch mechanism 60 (described later). The front end of the switch holder portion 30 is configured as a front holder portion 32, which is formed in a generally rectangular plate shape with its thickness extending in the front-to-rear direction. An inductor housing / holding portion 32A (see FIGS. 2 and 6 ) serving as a second component holding portion is formed in the left-to-right middle portion of the upper surface of the front holder portion 32. The inductor housing / holding portion 32A is formed in a generally rectangular shape with its longitudinal direction extending in the left-to-right direction in a plan view. A communicating groove 32B (see FIGS. 4 and 6 ) is formed in the right end of the upper surface of the front holder portion 32, which is upwardly open and penetrates in the left-to-right direction. As a result, the inductor accommodating and holding portion 32A is in communication with the outside of the switch holder portion 30 via the communicating groove 32B. The groove width (front-rear dimension) of the communicating groove 32B is set smaller than the front-rear dimension of the inductor accommodating and holding portion 32A. A concave threaded portion 32C (see FIG. 6) that is open upward is formed at the left end of the top surface of the front holder portion 32, and a female thread is formed on the inner circumferential surface of the threaded portion 32C.

[0028] The switch holder portion 30 has a central portion in the front-rear direction that serves as a switch accommodating portion 34. The switch accommodating portion 34 is generally formed in a generally rectangular recessed shape that is open upward and extends in the left-right direction. The switch holder portion 30 is provided with a partition wall 30A (see FIGS. 2, 4, 6, and 8) that separates the opening of the inductor accommodating / holding portion 32A from the opening of the switch accommodating portion 34. The partition wall 30A is generally formed as an elongated plate with its thickness extending in the front-rear direction and its length extending in the left-right direction, and extends upward from the top surface of the front holder portion 32. In other words, the partition wall 30A protrudes above the inductor accommodating / holding portion 32A and the switch accommodating portion 34. The partition wall 30A also extends across the entire left-right direction of the switch holder portion 30.

[0029] As shown in FIGS. 5 to 7 , an exposure hole 34A is formed through the bottom wall of the switch accommodating portion 34 to expose a heat sink 65 of the switch 62 (described later) downward. The exposure hole 34A is formed in a generally rectangular shape with the left-right direction as the longitudinal direction, and the exposure hole 34A is formed over substantially the entire bottom wall of the switch accommodating portion 34. That is, the bottom wall of the switch accommodating portion 34 is formed in a generally rectangular frame shape. The upper ends of the left and rear walls of the switch accommodating portion 34 are located below the upper surface of the front holder portion 32, and the upper end of the right wall of the switch accommodating portion 34 is positioned substantially flush with the upper surface of the front holder portion 32. A stepped recess 34B, which is one step lower to the right, is formed in the outer periphery of the left edge of the upper opening of the switch accommodating portion 34 (i.e., the outer periphery of the upper end of the left wall of the switch accommodating portion 34). The stepped recess 34B is formed over the entire left wall of the switch accommodating portion 34 in the front-to-rear direction.

[0030] A first notch 34C (see FIG. 6) is formed in the left part of the rear wall of the switch accommodating section 34, and the first notch 34C is formed in a recessed shape that opens upward when viewed from the rear. A second notch 34D (see FIGS. 4 and 6) is formed in the front part of the right wall of the switch accommodating section 34, and the second notch 34D is formed in a recessed shape that opens upward when viewed from the right.

[0031] The rear portion of the switch holder portion 30 is configured as a rear holder portion 36. The rear holder portion 36 is formed in a generally rectangular block shape with its thickness extending vertically, and extends rearward from the lower portion of the rear wall of the switch accommodating portion 34. A placement recess 36A is formed in the front left portion of the rear holder portion 36, in which a plunger 64 of a switch 62 (described below) is placed. The placement recess 36A is formed in a recessed shape that is open upward and leftward, and a first cutout 34C connects the interior of the placement recess 36A to the interior of the switch accommodating portion 34.

[0032] A support boss 36B is formed in the left-right middle of the rear of the rear holder portion 36, behind the placement recess 36A. The support boss 36B is formed in a generally bottomed, cylindrical shape that is open downward and protrudes upward from the rear holder portion 36. A fixing boss 36C is formed on the upper end of the rear holder portion 36, to the right of the support boss 36B. The fixing boss 36C is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction and extends rearward from the rear wall of the switch accommodating portion 34. The rear wall of the tail cover 22 is fastened to the switch holder portion 30 by a fixing screw (not shown) that is threaded into the fixing boss 36C.

[0033] A fixed pillar 36D is formed at the right end of the rear holder portion 36. The fixed pillar 36D is formed in a rectangular pillar shape extending in the vertical direction and protrudes upward from the rear holder portion 36. A concave threaded portion 36E that opens upward is formed on the upper surface of the fixed pillar 36D, and a female thread is formed on the inner peripheral surface of the threaded portion 36E. A wiring groove 36F (see FIGS. 4 and 6) is formed between the switch accommodating portion 34 and the fixed pillar 36D. The wiring groove 36F is formed in a groove shape that extends in the left-right direction and opens upward. The left end of the wiring groove 36F communicates with the right end of the switch accommodating portion 34, and the right end of the wiring groove 36F opens to the right.

[0034] (Regarding the gear housing 40) As shown in Figures 1 and 2, the gear housing 40 is hollow and generally triangular when viewed from the left and right, and is open downward. A connected portion 40A is formed at the rear end of the gear housing 40, and the connected portion 40A is formed in a generally rectangular tubular shape corresponding to the fan accommodating portion 26A of the motor accommodating portion 26. The fan accommodating portion 26A and the connected portion 40A are abutted against each other in the front-to-rear direction, and the connected portion 40A is fastened and fixed to the fan accommodating portion 26A. A packing gland 41 is provided on the underside of the gear housing 40. The packing gland 41 is formed in a stepped cylindrical shape with its axial direction extending vertically and is fixed to the gear housing 40.

[0035] A spindle 42 is provided within the gear housing 40 and is formed in a generally cylindrical shape with its axial direction extending vertically. The upper end of the spindle 42 is rotatably supported by a bearing 43 fixed to the gear housing 40, and the vertical middle portion of the spindle 42 is rotatably supported by a bearing 44 fixed to the packing gland 41. A grinding stone 45 is attached to the lower end (one axial end) of the spindle 42. The grinding stone 45 rotates together with the spindle 42 by the driving force of a motor 50 (described later), thereby performing grinding or other processing on the workpiece. A wheel guard 46 is detachably fixed to the lower end of the packing gland 41, and the wheel guard 46 covers a portion of the grinding stone 45.

[0036] (Regarding the Motor 50) As shown in FIG. 2 , the motor 50 is housed in the motor housing portion 26 of the motor housing 24. The motor 50 has a rotary shaft 50A whose axial direction is the front-to-rear direction. The rear end of the rotary shaft 50A is rotatably supported by a first motor bearing 51 fixed to the bearing fixing portion 26B of the motor housing portion 26, and the front end portion of the rotary shaft 50A is rotatably supported by a second motor bearing 52 fixed to the gear housing 40. The front end of the rotary shaft 50A is disposed within the gear housing 40, and a pinion gear 53 is fixed to the front end of the rotary shaft 50A. The pinion gear 53 meshes with a bevel gear 54 provided at the upper end portion of the spindle 42, so that the driving force of the motor 50 is transmitted to the spindle 42 via the bevel gear 54. The motor 50 is electrically connected to a switch 62, which will be described later.

[0037] A fan 55 is mounted on the front end of the rotating shaft 50A so as to rotate integrally with the rotating shaft 50A. The fan 55 is configured as a centrifugal fan with its thickness direction aligned in the front-to-rear direction. Specifically, the fan 55 directs air flowing into the center of the fan 55 from the rear side radially outward and then toward the front side via a fan guide 56 attached to the motor housing 26. As a result, when the motor 50 is driven, an airflow AR is generated that flows into the housing 20 through the air intake 22A of the tail cover 22, and the airflow AR flows toward the front side within the housing 20 and is discharged through the exhaust port 40B (see FIG. 1) formed in the gear housing 40.

[0038] 2 to 8 , the switch mechanism 60 includes a switch 62, a switch cover 70, a capacitor 80 as a first electronic component, an inductor 82 as a second electronic component, and a rotational speed adjustment device 84. The switch holder portion 30 of the motor housing 24 described above forms the framework of the switch mechanism 60, and the switch 62 and the switch cover 70 are assembled to the switch holder portion 30.

[0039] (Regarding the Switch 62) As shown in FIGS. 2 and 4 to 9, the motor 50 is electrically connected to the switch 62, which is configured to switch the motor 50 between a stopped state and a driven state. The switch 62 includes a switch body 63 and a plunger 64. The switch body 63 is formed in a generally rectangular parallelepiped shape with its longitudinal direction extending in the left-right direction and its thickness direction extending in the front-rear direction, corresponding to the shape of the switch accommodating portion 34 of the switch holder portion 30. The switch body 63 is accommodated in the switch accommodating portion 34 from above, and the switch 62 is located in front of the air intake 22A of the tail cover 22. When the switch body 63 is accommodated in the switch accommodating portion 34, the upper end of the switch body 63 protrudes above the left and rear walls of the switch accommodating portion 34. The switch 62 is configured as a switch with a built-in control circuit, and switching elements and the like that constitute the control circuit are provided within the switch body 63. For this reason, the switch body 63 has a heat sink 65 for dissipating heat generated by the switching element, and the heat sink 65 forms part of the outer casing (lower end) of the switch body 63 .

[0040] The heat sink 65 is made of a metal (aluminum in this embodiment) with good thermal conductivity. The heat sink 65 includes a base portion 65A constituting the upper portion of the heat sink 65 and a plurality of fins 65B constituting the lower portion of the heat sink 65. The base portion 65A is formed in a generally rectangular plate shape with its thickness extending vertically and its length extending horizontally, allowing heat generated by the switching elements in the switch body 63 to be transferred to the base portion 65A. The fins 65B are formed as ribs extending in the front-rear direction and protruding downward from the base portion 65A. The plurality of fins 65B are arranged side by side at predetermined intervals in the left-right direction. The heat sink 65 is disposed within the exposure hole 34A of the switch accommodating portion 34 and is exposed downward from the switch accommodating portion 34 through the exposure hole 34A. More specifically, the protruding height of the fins 65B from the base portion 65A is set so that the lower ends of the fins 65B protrude below the bottom surface of the switch accommodating portion 34. As a result, the heat sink 65 is cooled by the air flow AR flowing forward from the intake port 22A (see FIG. 2).

[0041] The plunger 64 protrudes rearward from the left portion of the switch body 63 and can be pushed forward. The plunger 64 is inserted through the first cutout 34C of the switch accommodating portion 34 and is disposed in the arrangement recess 36A of the rear holder portion 36. The rear end of the slide bar 14 described above is disposed behind the plunger 64 within the arrangement recess 36A. As a result, when the switch lever 12 is slid forward, the slide bar 14 presses the plunger 64 forward, causing the switch 62 to transition from an OFF state to an ON state, and the motor 50 to switch from a stopped state to a driven state.

[0042] A terminal 94 provided at one end of a pair of wires 92 on the power cord 90 is connected to the front end of the left side of the switch body 63, and power is supplied to the switch 62 via the wires 92. The pair of terminals 94 are arranged side by side at a predetermined interval in the vertical direction, and the wires 92 extend rearward from the terminals 94. The wires 92 extending rearward are bent upward and routed between a pair of front and rear wiring ribs 63C formed at the rear end of the upper surface of the switch body 63, and extend to the right from the switch accommodating portion 34. A pair of upper and lower partition walls 63A (see FIGS. 6 to 8) are formed on the left side of the switch body 63 to separate the pair of upper and lower terminals 94. The partition walls 63A are rib-shaped with the thickness direction being the vertical direction and extending in the front-rear direction, and extend left and right in the switch body 63 except for the rear end. The wires 92 extending from the lower terminal 94 are routed behind the partition wall 63A. The pair of upper and lower partition walls 63A are located below the upper end of the left wall of the switch accommodating portion 34 and are disposed adjacent to the right side of the left wall. As a result, the space in which the terminals 94 are disposed on the left side of the switch main body 63 is isolated by the partition wall 63A and the switch accommodating portion 34. In addition, a protrusion 63B that protrudes to the right is formed at the front end of the right side of the switch main body 63. The protrusion 63B is disposed in a second cutout portion 34D of the switch accommodating portion 34 and is exposed from the switch accommodating portion 34.

[0043] 2 to 4, 6 to 8, and 10, the switch cover 70 is configured as a cover member that covers the switch holder portion 30 from above, and is formed in a generally crank-shaped plate shape when viewed from the left and right. Specifically, the switch cover 70 is configured to include a front cover portion 72 as a first cover portion that forms the front portion of the switch cover 70, and a rear cover portion 74 as a second cover portion that forms the rear portion of the switch cover 70, with the front cover portion 72 being positioned one step higher than the rear cover portion 74.

[0044] The front cover 72 is formed in a generally rectangular plate shape with its thickness extending vertically and its length extending horizontally. The front cover 72 is disposed above the front holder 32 and the switch accommodating portion 34 of the switch holder 30, and closes the upper openings of the inductor accommodating and holding portion 32A and the switch accommodating portion 34 from above.

[0045] A fixing hole 72A is formed through the left end of the front end portion of the front cover portion 72 at a position corresponding to the threaded portion 32C of the front holder portion 32. A fixing screw SC1 is inserted through the fixing hole 72A and threadedly engages with the threaded portion 32C, thereby fastening and fixing the front cover portion 72 (switch cover 70) to the switch holder portion 30. A recessed counterbore portion 72B that is open upward is formed on the top surface of the front cover portion 72 at a position corresponding to the fixing hole 72A, and the head of the fixing screw SC1 is disposed within the counterbore portion 72B.

[0046] A fitting groove 72C is formed on the underside of the front cover 72 at a position corresponding to the partition wall 30A of the switch holder 30. The fitting groove 72C is formed as a groove that opens downward and extends in the left-right direction. The partition wall 30A is fitted into the fitting groove 72C, thereby fitting the switch holder 30 and the switch cover 70 together (see FIGS. 2 and 8).

[0047] A cover-side accommodating recess 72D is formed on the underside of the front cover 72 at a position corresponding to the inductor accommodating / holding portion 32A. The cover-side accommodating recess 72D is formed in a concave shape that is open downward and has a generally rectangular shape with its longitudinal direction extending in the left-right direction when viewed from below (see FIG. 10 ). The size of the cover-side accommodating recess 72D when viewed from below is set to be generally the same as the size of the inductor accommodating / holding portion 32A.

[0048] The front cover portion 72 has a side vertical wall 72E extending downward from the left outer periphery of the front cover portion 72 and an intermediate vertical wall 72F extending downward from the rear outer periphery of the front cover portion 72, with the rear end of the side vertical wall 72E connected to the left end of the intermediate vertical wall 72F. The lower ends of the side vertical wall 72E and the intermediate vertical wall 72F abut from above against the upper end surfaces of the left wall and rear wall of the switch accommodating portion 34. As a result, the front cover portion 72 covers the upper end of the switch 62 (switch main body 63) accommodated in the switch accommodating portion 34 from the left and rear sides.

[0049] An insertion piece 72G is integrally formed on the lower end surface of the side vertical wall 72E. The insertion piece 72G extends downward from the outer periphery of the lower end surface of the side vertical wall 72E and is disposed in the stepped recess 34B of the switch accommodating portion 34 (see FIG. 7). That is, the mating portion between the left wall of the switch accommodating portion 34 and the side vertical wall 72E of the front cover portion 72 is fitted with a so-called spigot joint, and engages so as to overlap in the left-right direction (the thickness direction of the wall portion).

[0050] A fixing piece 72H is provided at the right end of the intermediate vertical wall 72F. The fixing piece 72H is formed in a plate shape with its thickness extending up and down, extends rearward from the intermediate vertical wall 72F, and is disposed adjacent to the upper side of the fixing column 36D of the switch holder portion 30. A fixing hole 72J is formed through the fixing piece 72H at a position corresponding to the threaded portion 36E. A fixing screw SC2 is inserted through the fixing hole 72J and threadedly engages with the threaded portion 36E, fastening the rear end of the front cover portion 72 to the switch holder portion 30.

[0051] A cover-side wiring groove 72K is formed at the rear end of the underside of the front cover portion 72. The cover-side wiring groove 72K is formed as a groove that opens downward and extends in the left-right direction, with the right end of the cover-side wiring groove 72K opening to the right. The wiring rib 63C and wiring 92 of the switch 62 are disposed within the cover-side wiring groove 72K. When the front cover portion 72 is fixed to the switch holder portion 30, the switch main body 63 is sandwiched vertically between the front cover portion 72 and the bottom wall of the switch accommodating portion 34, thereby fixing the switch 62.

[0052] A capacitor housing / holding portion 72L is formed on the upper surface of the front cover portion 72 as a first component holding portion for housing and holding a capacitor 80 (described later). The capacitor housing / holding portion 72L is formed in a concave shape that opens upward. When viewed from above, it has a generally rectangular shape with its longitudinal direction extending in the left-right direction, corresponding to the outer shape of the capacitor 80 (described later). The capacitor housing / holding portion 72L is provided with a pair of front and rear holding claws 72M. One holding claw 72M extends upward from the left side of the front opening edge of the capacitor housing / holding portion 72L, with its upper end bent rearward. The other holding claw 72M extends upward from the right side of the rear opening edge of the capacitor housing / holding portion 72L, with its upper end bent forward. The holding claws 72M are configured to be elastically deformable in the front-to-rear direction. A guide portion 72N that guides the wiring 87 is provided at the rear end of the front cover portion 72. The guide portion 72N restricts left-to-right movement of the wiring 87.

[0053] The rear cover portion 74 is configured to hold the rotation speed adjustment device 84 (described later). The rear cover portion 74 is formed as a generally rectangular plate with its thickness extending vertically and extending rearward from the lower end of the intermediate vertical wall 72F of the front cover portion 72. A left side wall 74A is formed at the left end of the rear cover portion 74, bending upward. The left side wall 74A is formed in a generally inverted T shape when viewed from the left side. A right side wall 74B is formed at the rear end of the right end of the rear cover portion 74, bending upward. The rear cover portion 74 has multiple (three in this embodiment) retaining claws 74C. Two retaining claws 74C are provided at the upper ends of the left side wall 74A and the right side wall 74B and protrude inward in the left-right direction from the left side wall 74A and the right side wall 74B. The other retaining claws 74C protrude rearward from the upper end of the intermediate vertical wall 72F. A retaining claw 74D extending in the front-rear direction is formed at the rear end of the rear cover portion 74, and the rear end of the retaining claw 74D is bent upward. The retaining claw 74D is configured to be elastically deformable in the vertical direction.

[0054] The rear cover portion 74 covers the placement recess 36A from above and is disposed adjacent to the upper side of the support boss 36B, and the support boss 36B restricts downward displacement of the rear cover portion 74. In other words, the rear cover portion 74 covers the plunger 64 of the switch 62 from above.

[0055] (Regarding the capacitor 80) As shown in Figures 2 to 4 and 6 to 8, the capacitor 80 is formed in a generally rectangular parallelepiped shape with its thickness extending vertically. The capacitor 80 is housed in the capacitor housing / holding portion 72L of the switch cover 70, and the upper ends of the holding claws 72M are engaged with the outer periphery of the capacitor 80. This holds the capacitor 80 on the upper outer periphery of the switch cover 70. The capacitor 80 is electrically connected to the control circuit of the switch main body 63. Specifically, a wire 81 extending from the capacitor 80 is connected to the protrusion 63B of the switch main body 63. The capacitor 80 is a smoothing element for supplying power to the motor 50.

[0056] (Regarding the inductor 82) As shown in Figures 2, 4, 6, and 9, the inductor 82 is formed in a generally rectangular columnar shape extending in the left-right direction. The lower portion of the inductor 82 is accommodated in the inductor accommodating and holding portion 32A of the switch holder portion 30, and the upper portion of the inductor 82 is accommodated in the cover-side accommodating recess 72D of the switch cover 70. The inductor 82 is sandwiched and held by the switch holder portion 30 and the switch cover 70 from both sides in the vertical direction. The inductor 82 is electrically connected to the control circuit of the switch body 63. Specifically, a wiring 83 extending to the right from the right end of the inductor 82 is routed in the communicating groove 32B of the switch holder portion 30 and is drawn out from the communicating groove 32B to the outside of the switch holder portion 30. The wiring 83 drawn out to the outside of the switch holder portion 30 is routed in the wiring groove 36F of the switch holder portion 30 and connected to the switch body 63.

[0057] (Regarding the Rotational Speed ​​Adjustment Device 84) As shown in FIGS. 2 to 4, 6, 8, and 9, the rotational speed adjustment device 84 is configured as a device for setting the rotational speed of the motor 50. The rotational speed adjustment device 84 has a base housing 85, which is formed in a generally rectangular recessed shape that is open upward. The base housing 85 is attached to the rear cover portion 74 of the switch cover 70. Specifically, the base housing 85 is inserted from the rear side between the holding claws 74C and the rear cover portion 74, and the holding claws 74C engage with the upper outer periphery of the base housing 85. Furthermore, the rear ends of the holding claws 74D engage with the rear end of the base housing 85, limiting rearward movement of the base housing 85. In this way, the rotational speed adjustment device 84 is held by the switch cover 70.

[0058] The rotation speed adjustment device 84 has an operation dial 86 and a circuit board 84A on which the operation dial 86 is mounted (see FIG. 8). The operation dial 86 is formed in a disk shape with its thickness extending vertically, and is disposed above the base housing 85 and supported by a circuit board within the base housing 85. The outer periphery of the rear end of the operation dial 86 is exposed through a dial hole 22B formed in the upper part of the tail cover 22 so as to be operable.

[0059] A rotary volume (not shown) is provided on a substrate within the base housing 85, and the rotary volume is configured as a rotary variable resistor and is electrically connected to the control circuit of the switch 62. Specifically, a wire 87 extending from the substrate of the base housing 85 is routed above the capacitor 80, routed through the wiring groove 36F, and connected to the switch body 63. The rotary volume is connected to the operation dial 86, and outputs an output signal corresponding to the rotation position of the operation dial 86 to the control circuit, thereby setting the rotation speed of the motor 50.

[0060] (Operation and Effect) Next, the operation and effect of the grinder 10 of this embodiment will be described.

[0061] When using the grinder 10 configured as described above for processing, the operator slides the switch lever 12 forward from the OFF position, causing the slide bar 14 to press the plunger 64 of the switch 62. This switches the switch 62 from the OFF state to the ON state, and the motor 50 enters a driving state. This causes the spindle 42 and grinding wheel 45 to rotate, allowing the grinder 10 to perform grinding or other processing on the workpiece. Furthermore, when the motor 50 is driven, the fan 55 rotates, generating an airflow AR that flows into the housing 20 through the air intake 22A. The airflow AR that flows in through the air intake 22A flows forward within the housing 20 and is discharged through the air exhaust 40B.

[0062] Dust is generated during grinding by the grinder 10. If metal dust enters the housing 20 and shorts out the pair of terminals 94 connected to the switch 62, this could interfere with the operation of the motor 50 or cause the motor 50 to stop.

[0063] In the grinder 10, a switch holder portion 30 that holds a switch 62 is provided in the motor housing 24 of the housing 20. A switch cover 70 is attached to the switch holder portion 30, and the switch 62 is covered by the switch holder portion 30 and the switch cover 70. Specifically, the switch holder portion 30 has a switch accommodating portion 34 that is a generally rectangular recess that opens upward, and the switch 62 is accommodated in the switch accommodating portion 34. The switch cover 70 is attached to the switch holder portion 30 from above, and the switch 62 is covered by the switch holder portion 30 and the switch cover 70. This improves the dust resistance of the switch 62. Furthermore, the switch cover 70 has a capacitor accommodating / retaining portion 72L (electronic component retaining portion), and a capacitor 80 electrically connected to the switch 62 is accommodated and retained in the capacitor accommodating / retaining portion 72L. This allows the switch cover 70, which enhances the dust resistance of the switch 62, to be used to hold the capacitor 80 (an electronic component that contributes to driving control of the motor 50) connected to the switch 62. Therefore, there is no need to provide a separate component for holding the capacitor 80 (electronic component), and the capacitors 80 can be centrally arranged around the switch 62. This contributes to suppressing an increase in the number of components and miniaturizing the grinder 10 while improving the dust resistance of the switch 62. As a result, an efficient dustproof structure for the switch 62 can be realized. In particular, in this embodiment, the capacitor 80 is held by the holding claws 72M, so the capacitor 80 cannot be removed unless the holding claws 72M are disengaged. This securely holds the capacitor 80, preventing it from shifting due to vibration or other factors. The switch cover 70 may hold other electronic components other than the capacitor 80. While the capacitor 80 is a smoothing component for supplying power to the motor 50, it may also be another electronic component, such as a noise-removing filter.In this embodiment, the inductor 82 and rotational speed adjustment device 84 (circuit board 82A, operation dial 86) described below are held in the switch cover 70, but it may also be configured to hold, for example, a control board equipped with a microcontroller or a panel device that displays the status of the work machine (disc grinder 10).

[0064] The capacitor housing / holding portion 72L is formed on the upper surface of the front cover portion 72 of the switch cover 70. That is, the capacitor 80 is provided on the upper outer periphery of the switch cover 70. This allows the switch 62 and the capacitor 80 to be arranged together, as described above. In particular, because the capacitor 80 is arranged above the switch 62 via the switch cover 70, it is possible to prevent the grinder 10 from becoming larger in size in the left-right and front-rear directions.

[0065] Additionally, an inductor housing / holding portion 32A for housing and holding the inductor 82 is provided on the upper surface of the front holder portion 32 of the switch holder portion 30. The inductor 82 is covered from above by the front cover portion 72 of the switch cover 70 and held in the switch holder portion 30 (and is restricted from moving upward). This allows the switch 62 and the inductor 82 to be centrally arranged in the switch holder portion 30. Furthermore, because the inductor 82 is fixed to the switch holder portion 30 by the switch cover 70, relative movement of the inductor 82 with respect to the housing 20 is suppressed, for example, even if an impact force or vibration is input to the grinder 10. As a result, the rotation speed of the motor 50 can be accurately detected. This effectively stabilizes the operation of the grinder 10. Note that, in addition to the inductor 82, another rotation speed detection element, such as a Hall element, may be used.

[0066] The switch holder 30 is provided with a partition wall 30A that separates the opening of the inductor accommodating / holding portion 32A from the opening of the switch accommodating portion 34 into front and rear sections. The partition wall 30A protrudes upward from the switch holder 30 and extends left and right. A fitting groove 72C is formed on the underside of the front cover 72 of the switch cover 70, and the partition wall 30A is fitted into the fitting groove 72C. This provides a so-called spigot-fit structure between the opening of the inductor accommodating / holding portion 32A and the opening of the switch accommodating portion 34. Therefore, even if dust enters the inductor accommodating / holding portion 32A, the partition wall 30A and the fitting groove 72C can prevent the dust from entering the switch accommodating portion 34. Therefore, even when the inductor 82 is held by the switch holder 30 and the switch cover 70, dust resistance of the switch 62 can be ensured.

[0067] Furthermore, in the switch holder portion 30, a stepped recess 34B is formed on the outer periphery of the left edge of the opening of the switch accommodating portion 34, and an insertion piece 72G that is inserted into the stepped recess 34B is provided at the lower end of the side vertical wall 72E of the switch cover 70. As a result, a so-called spigot-fit structure is also provided at the mating portion between the switch accommodating portion 34 and the switch cover 70. Therefore, in this respect, it is possible to prevent dust from entering the switch accommodating portion 34, and thus it is possible to further improve the vibration-proofing properties of the switch 62.

[0068] Furthermore, when the switch 62 is housed in the switch accommodating portion 34, the switch 62 (switch holder portion 30) is sandwiched from both the top and bottom sides by the bottom wall of the switch accommodating portion 34 and the front cover portion 72 of the switch cover 70. This makes it possible to restrict upward movement of the switch 62 by utilizing the switch cover 70. That is, for example, upward movement of the switch 62 can be restricted without providing a hook or the like on the switch holder portion 30 for restricting upward movement of the switch 62. This contributes to the miniaturization of the switch accommodating portion 34 and prevents the structure of the switch accommodating portion 34 from becoming complicated.

[0069] Furthermore, terminals 94 of a pair of wires 92 for supplying power to the switch 62 are connected to the left side of the switch 62, and the pair of terminals 94 are arranged side by side, one above the other. The lower terminal 94 is covered by the left wall of the switch accommodating portion 34, and the upper terminal 94 is covered by the side vertical wall 72E of the switch cover 70. In other words, the joint between the left wall of the switch accommodating portion 34 and the side vertical wall 72E is located between the pair of upper and lower terminals 94. This allows the terminals 94 to be covered by the switch accommodating portion 34 and the switch cover 70 while ensuring the rigidity of the concave switch accommodating portion 34 that is open upward.

[0070] Additionally, a pair of upper and lower partition walls 63A are provided on the left side of the switch body 63 to vertically separate the pair of terminals 94. The partition walls 63A are formed as ribs extending in the front-to-rear direction with the thickness of the partition walls 63A being in the vertical direction. This allows the partition walls 63A to separate the space in the switch body 63 where the terminals 94 are arranged. Therefore, even if dust or the like invades the space where the upper terminals 94 are arranged, the partition walls 63A can prevent the dust from entering the space where the lower terminals 94 are arranged. Furthermore, the left end of the partition wall 63A is positioned adjacent to the left wall of the switch housing 34. Therefore, the partition walls 63A, the switch housing 34, and the switch cover 70 effectively separate the space where the terminals 94 are arranged.

[0071] Furthermore, a rotational speed adjustment device 84 (an example of an electronic component) that sets the rotational speed of the motor 50 is held in the rear cover portion 74 of the switch cover 70, and an operation dial 86 of the rotational speed adjustment device 84 is operably exposed through the dial hole 22B of the tail cover 22. This makes it possible to hold the rotational speed adjustment device 84 (inside the tail cover 22) by utilizing the switch cover 70, which improves the dustproofness of the switch 62. In other words, the rotational speed adjustment device 84 can be held inside the tail cover 22 without providing a separate member for holding the rotational speed adjustment device 84. This contributes to suppressing an increase in the number of parts in the grinder 10, and also suppresses an increase in the size of the grinder 10.

[0072] Furthermore, in the switch cover 70, the rear cover portion 74 that holds the rotational speed adjustment device 84 covers the plunger 64 of the switch 62 from above. This allows the rotational speed adjustment device 84 to be disposed by utilizing the space above the plunger 64, and also prevents dust that enters the housing 20 from directly adhering to the plunger 64 from above. Therefore, the switch cover 70 allows the rotational speed adjustment device 84 to be disposed efficiently, while also improving the dust resistance of the plunger 64 that is exposed from the switch accommodating portion 34.

[0073] The switch cover 70 is fastened to the switch holder portion 30 by the fixing screws SC1 and SC2. This makes it possible to maintain a good assembled state of the switch cover 70 to the switch holder portion 30, and also to maintain a good fixed state of the switch 62 and the inductor 82.

[0074] In the grinder 10, the heat sink 65 forms part of the outer casing of the switch 62, and the heat generated by the switching element provided inside the switch 62 is dissipated to the outside of the switch 62 by the heat sink 65. As described above, the switch 62 is housed in the switch accommodating portion 34 of the motor housing 24, and the heat sink 65 is exposed to the outside of the switch accommodating portion 34 through the exposure hole 34A of the switch accommodating portion 34. Therefore, the switch 62 can be cooled appropriately.

[0075] Furthermore, the switch accommodating portion 34 of the motor housing 24 is formed in a rectangular recess that is open upward, and an exposure hole 34A that exposes the heat sink 65 is formed in the bottom wall of the switch accommodating portion 34. This allows the switch 62 to be accommodated in the switch accommodating portion 34 from the upper opening of the switch accommodating portion 34 while ensuring the rigidity of the switch accommodating portion 34, and also allows the heat sink 65 to be exposed to the outside of the switch accommodating portion 34.

[0076] Furthermore, the fins 65B of the heat sink 65 protrude downward from the exposure hole 34A of the switch accommodating portion 34. This allows the airflow AR flowing forward inside the housing 20 to directly hit the fins 65B, thereby cooling the heat sink 65. This increases the cooling effect on the heat sink 65 and allows the switch 62 to be cooled more effectively.

[0077] As described above, the airflow AR flowing into the housing 20 from the intake port 22A of the tail cover 22 flows forward within the housing 20 and is discharged to the outside of the housing 20 from the exhaust port 40B of the gear housing 40. The heat sink 65 has a plurality of fins 65B formed in the shape of ribs extending in the front-to-rear direction. This allows the airflow AR to flow forward along the fins 65B without being blocked by the fins 65B as it flows forward within the housing 20. Therefore, the heat sink 65 can be effectively cooled by the airflow AR.

[0078] The heat sink 65 includes a base 65A with its longitudinal direction extending in the left-right direction and a plurality of fins 65B protruding downward from the base 65A, with the fins 65B arranged side by side in the left-right direction. That is, the fins 65B are arranged side by side in the longitudinal direction of the base 65A. This allows the number of fins 65B in the heat sink 65 to be maximized. This allows the heat sink 65 to be cooled more effectively by the airflow AR.

[0079] Furthermore, the motor housing 24, which includes the motor accommodating portion 26 and the switch holder portion 30, is constructed from a single, inseparable member. This allows the switch accommodating portion 34 to be formed as a single unit while preventing the formation of a dividing surface at the exposure hole 34A, for example. This improves the dustproofness of the switch accommodating portion 34 against the switch 62 and also increases the rigidity of the switch accommodating portion 34.

[0080] In the present embodiment, the mating portion between the left wall of the switch accommodating portion 34 in the switch holder portion 30 and the side vertical wall 72E of the switch cover 70 is located between the pair of upper and lower terminals 94, but the vertical position of this mating portion can be set as desired. For example, the mating portion between the left wall of the switch accommodating portion 34 and the side vertical wall 72E may be set above the pair of upper and lower terminals 94. In addition, in the above configuration, the capacitor 80, the inductor 82, and the rotation speed adjustment device 84 (dial) are described as examples of electronic components held by the switch cover 70. However, the electronic components (first and second electronic components) held by the switch cover 70 are not limited to these. The electronic components may be any components that have some function as a work machine. Specifically, the electronic components may include the above-mentioned control board and panel device equipped with a microcontroller, as well as electronic components that contribute to improving workability, such as notification means (such as a light) that indicates the state of the motor 26, whether it is running or stopped, and components related to driving or controlling the motor 26. The effect is particularly great when the electronic component is large in mass or size and can obstruct assembly or the air passage, that is, when the electronic component is connected to a wiring for power supply.

[0081] 10...Disc grinder (work machine), 20...Housing, 26...Motor accommodating section, 30...Switch holder section (switch holding section), 30A...Partition wall, 32A...Inductor accommodating and holding section (second component holding section), 34...Switch accommodating section, 34B...Step recessed motor, 5050A...Rotating shaft, 62...Switch, 63A...Partition wall, 70...Switch cover, 72C...Fitting groove section, 72G...Insertion piece, 72L...Capacitor accommodating and holding section (first component holding section), 80...Capacitor (first electronic component), 82...Inductor (second electronic component), 84...Rotational speed adjustment device, 92...Wiring, 94...Terminal

Claims

1. A motor; a working unit driven by the motor; a switch that is disposed on one side of the motor in a first direction and that switches between an ON state that drives the motor and an OFF state that stops the motor; a housing having a motor accommodating portion that accommodates the motor and a switch holding portion that holds the switch; a switch cover provided on the switch holding portion and covering the switch together with the switch holding portion; a wiring having a terminal portion at one end electrically connected to the switch; a first electronic component connected to a control circuit for driving the motor; Equipped with the switch cover and the switch holding portion define a space that accommodates at least a portion of the switch, the wiring is routed from the outside to the inside of the space, and the terminal portion is disposed inside the space, The switch cover has a first component holder that holds the first electronic component.

2. The work machine according to claim 1 , wherein the first component holding portion is formed on an outer periphery of the switch cover.

3. the switch holding portion is provided with a second component holding portion that accommodates a second electronic component, The work machine according to claim 1 , wherein the second electronic component is covered by the switch cover and held by the switch holder.

4. The switch holding portion a switch accommodating portion that is open to one side in a second direction perpendicular to the first direction and that accommodates the switch; the second component holding portion that is open to one side in the second direction; a partition wall that partitions an opening between the switch accommodating portion and the second component holding portion and that protrudes further toward one side in the second direction than the switch accommodating portion and the second component holding portion; It has The work machine according to claim 3 , wherein the switch cover covers the switch accommodating portion and the second component holding portion from one side in the second direction, and has a fitting groove into which the partition wall is fitted.

5. a stepped recess is formed on the outer periphery of the edge of the opening of the switch accommodating portion, The work machine according to claim 4, wherein the switch cover is provided with an insertion piece that is inserted into the stepped recess.

6. The work machine according to claim 4 , wherein the switch is sandwiched between the switch accommodating portion and the switch cover in the second direction.

7. A pair of wiring terminals for supplying power to the switch are connected to the switch, 2. The work machine according to claim 1, wherein one of the terminals is covered by the switch holding portion, and the other of the terminals is covered by the switch cover.

8. A pair of wiring terminals for supplying power to the switch are connected to the switch, The work machine according to claim 1, wherein the pair of terminals are covered by the switch holding portion or the switch cover.

9. 9. The work machine according to claim 7, wherein the switch is provided with a partition that separates the pair of terminals.

10. the first electronic component is a rotation speed adjusting device that sets the rotation speed of the motor, 2. The work machine according to claim 1, wherein the rotational speed adjusting device is operably exposed from the housing and is held by the switch cover.

11. a rotational speed adjusting device for setting the rotational speed of the motor is operably exposed from the housing; The switch cover is a first cover portion that covers the switch and has the first component holding portion; a second cover portion that holds the rotational speed adjustment device and covers the plunger of the switch from one side in a second direction perpendicular to the first direction; The work machine according to claim 1, further comprising:

12. The work machine according to claim 1, wherein the switch cover is fastened and fixed to the switch holding portion.

13. 2. The work machine according to claim 1, wherein the first electronic component is a smoothing element.

14. 2. The work machine according to claim 1, wherein the first electronic component is a rotation speed detection element for detecting the rotation speed of the motor.

15. 4. The work machine according to claim 3, wherein the first electronic component is a smoothing element, and the second electronic component is a rotation speed detection element for detecting the rotation speed of the motor.

16. A fan rotated by the motor; an air intake provided in the housing; Equipped with The switch is provided with a heat sink for dissipating heat generated by the switch, The switch holding portion is provided with an exposure hole that is open to one side in a second direction perpendicular to the first direction, The work machine according to claim 1 , wherein the heat sink is exposed to the outside of the switch holding portion through the exposure hole, and is cooled by cooling air from the intake port generated by rotation of the fan.