JP7517082B2 - Work Machine - Google Patents

Description

The present invention relates to a work machine.

In the electric trimmer (working machine) described in Patent Document 1 below, a cylindrical portion of a base is fitted onto a motor case (housing). A slit is formed in the cylindrical portion of the base, and a shaft is bridged between flanges at both circumferential ends of the base. A lever is connected to the shaft, and when the lever is operated, the cylindrical portion of the base deforms to tighten the motor case, and the cylindrical portion is fixed to the motor case.

Japanese Patent Application Publication No. 10-217203

However, the above electric trimmer has room for improvement in the following respects. That is, when the lever is operated to release the fastening force of the cylindrical portion of the base to the motor case, the fixing force of the cylindrical portion to the motor case is immediately released, causing the base to fall from the motor case. This requires the operator to support the base while performing the lever release operation. Therefore, the above electric trimmer has room for improvement in terms of realizing a suitable fixing structure for the base.

Taking the above facts into consideration, the present invention aims to realize a suitable fixing structure for the base.

One or more embodiments of the present invention include a housing having a cylindrical portion, a motor accommodated in the housing, an output shaft rotated by the motor to which a tool bit can be attached, an outer insertion portion having an abutment surface that can abut against a workpiece and formed in a cylindrical shape that is inserted into the cylindrical portion and has a portion that is open radially outward, a first clamp portion that constitutes one circumferential end of the outer insertion portion, and a second clamp portion that constitutes the other circumferential end of the outer insertion portion, a fixing mechanism that is provided on the base and is operated to switch between a fixed state in which the first clamp portion and the second clamp portion are brought closer to each other to clamp the outer insertion portion to the cylindrical portion and fix the base to the housing , and a release state in which the first clamp portion and the second clamp portion are separated to release the fixed state of the base to the housing , and a locking mechanism that is provided on the base and is operable to lock the base to the housing in a released state. and a holding mechanism that holds the base in a temporarily fixed state to the housing in a fixed state, the fixing mechanism having a clamp lever that can be operated by an operator and that can rotate between a fixed position and a released position, the clamp lever having a cam portion that presses the first clamp portion when located at the fixed position to place the base in the fixed state, and that releases the pressure on the first clamp portion when located at the released position to place the base in the released state, the holding mechanism having a biasing member that generates a frictional force between the cylindrical portion and the base when the clamp lever is located at the released position to hold the base in the temporarily fixed state, and the base in the temporarily fixed state is fixed to the housing so that it can be moved by hand by an operator while being prevented from falling from the housing due to its own weight .

One or more embodiments of the present invention are a work machine in which, when the fixing mechanism is released, the biasing member biases the first clamp portion and the second clamp portion in a direction toward each other, thereby maintaining the base in a temporarily fixed state.

In one or more embodiments of the present invention, the holding mechanism is a work machine configured to include a connecting shaft that is stretched across the first clamp section and the second clamp section so as to be relatively movable in the axial direction, and a biasing member that is attached to the connecting shaft and biases the first clamp section and the second clamp section in a direction to bring them closer to each other.

In one or more embodiments of the present invention, one end of the connecting shaft engages with the first clamp portion to restrict movement of the connecting shaft to the other axial side, and the biasing member biases the second clamp portion toward the one axial side of the connecting shaft and the connecting shaft toward the other axial side.

In one or more embodiments of the present invention, the biasing member is configured as a compression coil spring.

In one or more embodiments of the present invention, the other end of the connecting shaft is provided with a locking portion that is connected to the connecting shaft so as to be movable relative to the connecting shaft in the axial direction, and one end of the biasing member is locked to the second clamp portion and the other end of the biasing member is locked to the locking portion, and the locking portion moves relative to the connecting shaft in the axial direction, thereby changing the biasing force of the biasing member against the second clamp portion and the connecting shaft.

One or more embodiments of the present invention are a work machine that includes a position change mechanism that is provided on the base and the housing and that is manually operated to change the relative position of the base with respect to the housing in the axial direction of the cylindrical portion, and that operates the position change mechanism when the fixing mechanism is in the released state, so that the base moves relative to the housing while maintaining the temporary holding state of the holding mechanism with respect to the base.

In one or more embodiments of the present invention, an operating knob is provided at one end of the connecting shaft, and the position change mechanism is actuated by rotating the connecting shaft with the operating knob.

In one or more embodiments of the present invention, the position change mechanism is provided on the housing and the base so as to change the position of the base in the circumferential direction of the cylindrical portion.

In one or more embodiments of the present invention, the position change mechanism is configured to include a rack provided on one of the cylindrical portion and the base and extending in the axial direction of the cylindrical portion, and a pinion provided on the other of the cylindrical portion and the base and meshing with the rack, and the overall length of the rack along the circumferential direction of the cylindrical portion is set to at least twice the width of the pinion.

One or more embodiments of the present invention are a work machine in which the rack is formed in multiple positions in the circumferential direction of the cylindrical portion.

One or more embodiments of the present invention are a work machine that includes a control unit that controls the operation of the motor, an operation unit that places the motor in a driven state or a non-driven state, and a state switching unit that can change the control state of the control unit for the motor by operation by an operator, and the control unit is a work machine that changes the control state after the change between when the state switching unit is operated while the motor is in the non-driven state and when the state switching unit is operated while the motor is in the driven state.

According to one or more embodiments of the present invention, a suitable fixing structure to the base can be realized.

1 is a side view showing an electric trimmer according to an embodiment of the present invention, as viewed from one side in a first direction. 2 is a side view of the electric trimmer shown in FIG. 1 as viewed from one side in a second direction. 3 is a side cross-sectional view (cross-sectional view taken along line 3-3 in FIG. 2) of the electric trimmer shown in FIG. 2 as viewed from one side in a first direction. 4 is a side cross-sectional view of the electric trimmer shown in FIG. 1 as viewed from one side in a second direction (cross-sectional view taken along line 4-4 in FIG. 1). 3 is an exploded perspective view of the trimmer body of the electric trimmer shown in FIG. 2, seen from below with an outer case detached from an inner case. FIG. FIG. 6 is a bottom view of the trimmer body shown in FIG. 5 . 5A is a side view of the inner case shown in FIG. 5 as viewed from one side in the second direction, and FIG. 8 is a cross-sectional view (cross-sectional view taken along line 8-8 in FIG. 1) of the fixing mechanism shown in FIG. 1 as viewed from one side in the second direction. 9 is a cross-sectional view of the fixing mechanism shown in FIG. 1 as viewed from above (cross-sectional view taken along line 9-9 in FIG. 1). 1 (a cross-sectional view taken along line 10-10 in FIG. 1 ). 11 is a cross-sectional view corresponding to FIG. 9 for illustrating a state in which the base is temporarily held to the housing by the holding mechanism shown in FIG. 10 . 2 is a functional block diagram for explaining the electrical configuration of a controller in the electric trimmer according to the present embodiment. FIG. 5 is a flowchart for explaining an operation of the electric trimmer according to the present embodiment. 11 is a cross-sectional view showing a modified example of the holding mechanism shown in FIG. 10.

The electric trimmer 10 as a working machine according to this embodiment will be described below with reference to the drawings. As shown in Figs. 1 to 4, the electric trimmer 10 is generally formed in a cylindrical shape. In the following description, one axial side of the electric trimmer 10 (the side indicated by the arrow A in Figs. 1 to 4) is the lower side of the electric trimmer 10, and the other axial side of the electric trimmer 10 (the side indicated by the arrow B in Figs. 1 to 4) is the upper side of the electric trimmer 10. In addition, in a plan view seen from above, a direction perpendicular to the up-down direction is a first direction (see arrows C and D in Figs. 2 and 4), and a direction perpendicular to the first direction is a second direction (see arrows E and F in Figs. 1 and 3).

The electric trimmer 10 is configured as a tool that performs cutting on a workpiece placed below the electric trimmer 10. The electric trimmer 10 includes a trimmer body 20, a base 60, a battery 58 as a power source, a fixing mechanism 70, a holding mechanism 80, a lifting mechanism 90 as a position changing mechanism, and a controller 100. Each component of the electric trimmer 10 will be described below.

(Regarding the trimmer body 20)
As shown in FIGS. 1 to 6, the trimmer body 20 includes a housing 22, a motor 34, a trigger 42 serving as an operation unit, a speed setting dial 46, and a lock button 50 serving as a state switching unit.

<Regarding the housing 22>
The housing 22 constitutes the outer shell of the trimmer body 20. The housing 22 has a double structure. Specifically, the housing 22 includes an inner case 24 that constitutes the inner peripheral portion of the housing 22, and an outer case 30 that constitutes the outer peripheral portion of the housing 22.

As shown in Figures 3 to 7, the inner case 24 is made of resin. The inner case 24 is formed in a generally bottomed cylindrical shape that is open to the bottom. Specifically, the inner case 24 includes an upper case portion 28 as a protruding portion that constitutes the upper end of the inner case 24, and a cylindrical inner tube portion 26 that extends downward from the upper case portion 28. The upper case portion 28 is formed in a generally rectangular shape when viewed from below, and protrudes further in the first direction than the inner tube portion 26 (the direction of arrow C in Figures 4 and 7 (A)).

The inner case 24 is also divided into two in the second direction. More specifically, the inner case 24 is composed of a first inner case 24A that constitutes one side of the inner case 24 in the second direction (the side indicated by the arrow E in Figs. 5 to 7), and a second inner case 24B that constitutes the other side of the inner case 24 in the second direction (the side indicated by the arrow F in Figs. 5 to 7). The first inner case 24A and the second inner case 24B are fastened and fixed together with their openings butted against each other.

The inner tube portion 26 is configured to include a pair of large diameter portions 26A that form the upper and lower ends of the inner tube portion 26, and a small diameter portion 26B that forms the vertical middle portion of the inner tube portion 26, and the diameter of the small diameter portion 26B is set to be smaller than the diameter of the large diameter portion 26A. An inner tube expanded diameter portion 26C that is raised one step radially outward is formed at the upper end of the upper large diameter portion 26A. A pair of expanded diameter protrusions 26D that protrude downward are formed in the inner tube expanded diameter portion 26C at one side and the other side in the first direction. As a result, the lower end of the inner tube expanded diameter portion 26C is formed in an uneven shape when viewed from the radial outside of the inner tube portion 26.

A trigger attachment portion 26E for attaching a trigger 42 (described later) is formed on the enlarged diameter protrusion 26D on one side in the first direction, and the trigger attachment portion 26E protrudes toward one side in the first direction from the enlarged diameter protrusion 26D. In addition, a button attachment portion 26F for attaching a lock button 50 (described later) is formed on the enlarged diameter protrusion 26D on the other side in the first direction, and the button attachment portion 26F is one step lower radially inward than the enlarged diameter protrusion 26D.

In the upper large diameter portion 26A, upper communication holes 26G (see Figures 3 and 7 (A)) are formed as communication parts at one side and the other side in the second direction. Specifically, the upper communication hole 26G is arranged between a pair of enlarged diameter protrusions 26D. The upper communication hole 26G is formed in a rectangular shape when viewed from the radial outside of the inner cylindrical portion 26, and the opening of the upper communication hole 26G is open to the lower side. In addition, at the boundary between the lower large diameter portion 26A and the small diameter portion 26B, three lower communication holes 26H (see Figures 3, 5, and 7 (A)) are formed as communication parts at one side and the other side in the second direction. That is, six lower communication holes 26H are formed in the inner cylindrical portion 26. The lower communication holes 26H are formed as elongated holes extending in the circumferential direction of the inner cylindrical portion 26, and are arranged in a line in the circumferential direction of the inner cylindrical portion 26.

A plurality of (four in this embodiment) abutment portions 26J (see Figures 5 and 7) are formed on the outer periphery of each of the pair of large diameter portions 26A. That is, in this embodiment, eight abutment portions 26J are formed on the inner cylinder portion 26. When viewed from the radial outside of the inner cylinder portion 26, the abutment portions 26J are formed in a substantially rectangular shape with the vertical direction as the longitudinal direction, and slightly protrude radially outward from the large diameter portion 26A. The abutment portions 26J are also arranged at equal intervals in the circumferential direction of the inner cylinder portion 26. At the upper end of the small diameter portion 26B, a protrusion portion 26K (see Figures 3 and 7) protruding radially outward is formed at the opening of the upper communication hole 26G on one side of the second direction.

At the lower end of the inner cylinder 26, a bearing holder 26L for holding a second bearing 36L described later is formed, and the bearing holder 26L is formed in a substantially annular plate shape with the plate thickness direction being the up-down direction, and extends radially inward from the lower end of the inner cylinder 26. The bearing holder 26L has a plurality of (five in this embodiment) inner exhaust ports 26M formed at the portions on one side and the other side in the second direction. Specifically, three inner exhaust ports 26M are formed at the portion on one side of the bearing holder 26L in the second direction, and two inner exhaust ports 26M are formed at the portion on the other side of the bearing holder 26L in the second direction. The inner exhaust ports 26M are formed in the shape of elongated holes extending in the circumferential direction of the inner cylinder 26, and are arranged in a line in the circumferential direction of the inner cylinder 26. In addition, the bearing holder 26L has a plurality of (four in this embodiment) fixing bosses 26N as fixing portions for fixing the outer case 30 described later. The fixing bosses 26N are formed in a cylindrical shape with the vertical direction as the axial direction, and are arranged at equal intervals around the circumference of the inner cylinder portion 26 and between the inner exhaust ports 26M. As a result, the fixing bosses 26N for fixing the outer case 30 (described later) are arranged radially inward with respect to the outer peripheral surface of the inner cylinder portion 26.

The upper case portion 28 is formed with a battery mounting portion 28A as a battery attachment/detachment portion for attaching a battery 58 (described later), and the battery mounting portion 28A is formed in a concave shape that is open to the upper side and to the other side in the first direction. The upper case portion 28 is also provided with a connector 32 (see Figures 3 and 4), and the connector 32 is exposed within the battery mounting portion 28A.

The side walls on both sides in the second direction of the upper case portion 28 have air intakes 28B (see Figures 2 and 3) formed through the lower end portions, and the air intakes 28B are formed as elongated holes with the first direction as their longitudinal direction. In other words, the air intakes 28B are located above the upper communication holes 26G of the inner case 24.

As shown in Figs. 1 to 6, the outer case 30 is made of metal and is constructed as a single member that cannot be disassembled. The outer case 30 is formed in a generally bottomed cylindrical shape with an axial direction extending in the vertical direction and open to the upper side. Specifically, the outer case 30 is constructed to include a cylindrical outer tube portion 30A and a case bottom portion 30B that constitutes the lower end portion of the outer case 30. The outer tube portion 30A is inserted onto the inner tube portion 26 of the inner case 24, and the inner tube portion 26 and the outer tube portion 30A form the tube portion 22A of the housing 22. Here, "insertion" refers to the state in which the outer peripheral portion of the target is inserted inward, and refers to the state in which the inner tube portion 26 is inserted inside the outer tube portion 30A.

The case bottom 30B has a through-hole 30C formed in the center thereof. Five outer exhaust ports 30D are formed in the case bottom 30B at positions corresponding to the inner exhaust ports 26M of the inner case 24, and the outer exhaust ports 30D are formed in the shape of long holes with the circumferential direction of the outer tube 30A as the longitudinal direction, corresponding to the inner exhaust ports 26M. As a result, the inside and outside of the inner case 24 are communicated by the inner exhaust ports 26M and the outer exhaust ports 30D. Furthermore, the case bottom 30B has four fixing holes 30E (see FIG. 5) formed in positions corresponding to the fixing bosses 26N of the inner case 24. Then, the fixing bolts BL (which are elements that can be broadly understood as fixing members) are inserted from below into the fixing holes 30E and screwed into the fixing bosses 26N, thereby fixing the outer case 30 to the inner case 24.

At the upper end of the outer case 30, a pair of case recesses, ie, case gouged portions 30F, are formed at positions corresponding to the enlarged diameter protrusions 26D of the inner case 24. The case gouged portions 30F are formed in a concave shape that opens upward, and are formed in a trapezoidal shape when viewed from the radial outside of the outer case 30. When the outer case 30 is fixed to the inner case 24, the upper end of the outer case 30 is disposed below the inner tube enlarged diameter portion 26C of the inner case 24, and the outer tube portion 30A covers the inner case 24 from the radial outside, except for the inner tube enlarged diameter portion 26C of the inner tube portion 26. In other words, the upper end of the outer case 30 covers the upper communication hole 26G so that it cannot be seen.

When the outer case 30 is fixed to the inner case 24, the inner peripheral surface of the outer tube portion 30A abuts against the abutment portion 26J of the inner case 24. As a result, a gap 22B (see Figures 3 and 4) is formed between the small diameter portion 26B and the outer case 30 in the tube portion 22A. The gap 22B is formed around the entire circumference of the tube portion 22A, and the upper end of the gap 22B is connected to the inside of the inner case 24 through the upper communication hole 26G, and the lower end of the gap 22B is connected to the inside of the inner case 24 through the lower communication hole 26H. The diameter of the outer tube portion 30A is set so that the outer peripheral surface of the outer tube portion 30A is flush with the outer peripheral surface of the inner tube enlarged diameter portion 26C of the inner case 24.

The inner peripheral surface at the upper end of the outer tube portion 30A is formed with an engagement groove 30G (see FIG. 3) as a groove portion at a position corresponding to the protrusion 26K of the inner case 24, and the engagement groove 30G extends in the vertical direction and is open to the upper side. When the outer case 30 is inserted onto the inner case 24, the protrusion 26K is inserted into the engagement groove 30G, and the protrusion 26K and the engagement groove 30G engage in the circumferential direction of the inner case 24.

As shown in Figures 2, 3, and 5, a first rack 92 and a second rack 94 are formed on the outer periphery of the outer tube portion 30A as a pair of racks constituting the lifting mechanism 90 described later. The first rack 92 is formed on one side of the outer tube portion 30A in the second direction, and the second rack 94 is formed on the other side of the outer tube portion 30A in the second direction, and the first rack 92 and the second rack 94 extend in the vertical direction. In other words, the first rack 92 and the second rack 94 are arranged 180 degrees apart in the circumferential direction of the outer tube portion 30A.

The first rack 92 has a plurality of rack grooves 92A, which extend in the circumferential direction of the outer tube portion 30A and open to the radially outward direction of the outer tube portion 30A. The plurality of rack grooves 92A are arranged in a line at equal intervals in the vertical direction. The portions between vertically adjacent rack grooves 92A are configured as rack teeth 92B. As a result, in the first rack 92, the plurality of rack teeth 92B are arranged in a line at equal intervals in the vertical direction.

The second rack 94 is configured in the same manner as the first rack 92. That is, the second rack 94 has multiple rack grooves 94A aligned in the vertical direction. In addition, in the second rack 94, the portion between vertically adjacent rack grooves 94A is configured as rack teeth 94B, and the multiple rack teeth 94B are arranged at equal intervals in the vertical direction.

<Regarding the motor 34>
As shown in Fig. 3 and Fig. 4, the motor 34 is configured as a brushless motor. The motor 34 is disposed in the inner cylinder portion 26 of the inner case 24 coaxially with the inner cylinder portion 26 and below the intake port 28B and the upper communication hole 26G, and is fixed to the inner cylinder portion 26. The upper end of the output shaft 34A of the motor 34 is rotatably supported by a first bearing 36U provided in the inner cylinder portion 26. Meanwhile, a lower end portion of the output shaft 34A is rotatably supported by a second bearing 36L as a bearing, and the second bearing 36L is held by the bearing holding portion 26L of the inner cylinder portion 26. The lower end (tip) of the output shaft 34A protrudes downward from the lower end of the housing 22, and a collecting chuck 38 is provided at the lower end of the output shaft 34A. The collecting chuck 38 detachably fixes the tip tool T to the lower end of the output shaft 34A. Furthermore, the motor 34 is electrically connected to a control unit 101, which will be described later, and the motor 34 is driven by the control unit 101. As a result, the workpiece is cut by the tool tip T, which rotates together with the output shaft 34A.

A fan 40 is mounted on the output shaft 34A of the motor 34 above the second bearing 36L so as to be able to rotate integrally with the motor. The fan 40 is configured as a so-called axial fan, and is configured to generate an air flow toward the lower side within the inner case 24. This allows the cooling air AR to flow into the inner case 24 from the intake port 28B, and to be exhausted to the outside of the housing 22 from the inner exhaust port 26M of the inner case 24 and the outer exhaust port 30D of the outer case 30.

<Regarding Trigger 42>
As shown in Fig. 4, the trigger 42 is configured as an operating part for driving or stopping the motor 34. The trigger 42 is attached to the trigger attachment part 26E of the inner case 24 and exposed so as to be operable toward one side in the first direction. In addition, the upper end part of the trigger 42 is rotatably supported by the inner case 24 with the second direction as the axial direction. As a result, the trigger 42 is configured to be rotatable between an initial position (position shown by a solid line in Fig. 4) and an operating position (position shown by a two-dot chain line in Fig. 4) rotated counterclockwise from the initial position as viewed from one side in the second direction. The trigger 42 is biased toward the initial position by a biasing spring (not shown), and is held at the initial position when the trigger 42 is not operated.

A microswitch 44 is provided as a switch on the other side of the trigger 42 in the first direction, and the microswitch 44 is electrically connected to the control unit 101, which will be described later. When the trigger 42 is operated from the initial position to the operating position, the lower end of the trigger 42 presses the microswitch 44, and the microswitch 44 outputs a detection signal to the control unit 101.

<About the speed setting dial 46>
The speed setting dial 46 is configured as a dial for changing the rotation speed of the motor 34. The speed setting dial 46 is formed in a substantially circular plate shape with the plate thickness direction being the up-down direction, and is supported by the inner case 24 within the other side part in the first direction of the upper case portion 28 of the inner case 24 so as to be rotatable with the up-down direction as the axial direction. The speed setting dial 46 is exposed from the upper case portion 28 so as to be operable toward the other side in the first direction.

An encoder 48 for detecting the rotational position of the speed setting dial 46 is provided above the speed setting dial 46, and the encoder 48 is electrically connected to the control unit 101. When the speed setting dial 46 rotates, a detection signal corresponding to the rotational position of the speed setting dial 46 is output from the encoder 48 to the control unit 101.

<Regarding the lock button 50>
The lock button 50 is provided on the button mounting portion 26F of the inner case 24 and is exposed from the button mounting portion 26F to the other side in the first direction. The lock button 50 is formed in a substantially rectangular shape when viewed from the other side in the first direction and is made of an elastic member. A button board 52 is provided adjacent to one side of the lock button 50 in the first direction, and a tact switch 54 is mounted on the button board 52. The tact switch 54 is electrically connected to a control unit 101, which will be described later. When the lock button 50 is pressed, the tact switch 54 outputs a detection signal to the control unit 101. In addition, although details will be described later, the lock button 50 is configured as a button that prohibits or permits the driving of the motor 34 when the battery 58 is connected to the connector 32 of the housing 22. In addition, the lock button 50 is also configured as a button that continues or stops the driving of the motor 34 while the motor 34 is being driven.

(Regarding base 60)
1 to 4, the base 60 is made of metal and is formed in a generally bottomed cylindrical shape that is open on the upper side. Specifically, the base 60 includes a base cylindrical portion 62 as an outer insertion portion, and a plate portion 64 that constitutes the lower end portion of the base 60.

The base tube portion 62 is formed in a substantially cylindrical shape with the vertical direction as the axial direction, and a part of the base tube portion 62 in the circumferential direction is open. That is, the base tube portion 62 is formed with a slit 62A extending in the vertical direction, and the slit 62A penetrates the base tube portion 62 in the vertical direction and in the radial direction. The width dimension of this slit 62A is set to be larger than the width dimensions of the first rack 92 and the second rack 94. The base tube portion 62 (base 60) is inserted from the bottom into the tube portion 22A of the housing 22 and fixed to the tube portion 22A by a fixing mechanism 70 described later. Specifically, when the base 60 is fixed to the housing 22, the first rack 92 or the second rack 94 is arranged inside the slit 62A when viewed from the radial outside of the base tube portion 62. The tube portion 22A of the housing 22 and the base tube portion 62 are configured as a gripping portion to be gripped by the operator.

An opening 62B is formed in the lower end of the base tube portion 62 at one side in the second direction, and the opening 62B is formed in a concave shape that is open downward when viewed from one side in the second direction. The lower end of the slit 62A is connected to the opening 62B. This allows the tool tip T fixed to the output shaft 34A to be seen through the opening 62B when the base 60 is connected to the housing 22.

A first clamp portion 62C is provided at one circumferential end of the base tube portion 62, and a second clamp portion 62D is provided at the other circumferential end of the base tube portion 62. The first clamp portion 62C and the second clamp portion 62D are formed in a generally long block shape with the vertical direction as the longitudinal direction, and protrude to one side in the second direction.

The plate portion 64 is formed in a generally rectangular plate shape with the plate thickness direction being the up-down direction, and is connected to the lower end of the base tube portion 62. A base insertion portion 64A (see Figures 3 and 4) is formed through the approximate center of the plate portion 64, through which the output shaft 34A and the tip tool T are inserted. The lower surface of the plate portion 64 is configured as a contact surface that contacts the workpiece when the workpiece is being processed.

A bevel base 66 is provided below the plate portion 64, and is formed in a generally rectangular plate shape with the plate thickness direction being the up-down direction. The bevel base 66 is fixed to the plate portion 64 by a fixing member such as a screw. The bevel base 66, like the plate portion 64, is formed with a bevel insertion portion 66A (see Figures 3 and 4) through which the tool T is inserted.

(Regarding battery 58)
1 and 2, the battery 58 is formed into a substantially rectangular parallelepiped. The battery 58 is attached to the battery attachment portion 28A of the housing 22 from the other side in the first direction. The battery 58 has a connector (not shown), and when the battery 58 is attached to the battery attachment portion 28A, the connector is connected to the connector 32, and power is supplied from the battery 58 to the control unit 101. The battery 58 also has a pair of locking members 58A, and the locking members 58A are provided on the side portions of the battery 58 on one side and the other side in the second direction. When the battery 58 is attached to the battery attachment portion 28A, the locking members 58A engage with the upper case portion 28 of the housing 22, restricting the movement of the battery 58 to the other side in the first direction.

(Regarding the fixing mechanism 70)
As shown in FIGS. 1 to 3, 8, and 9, the fixing mechanism 70 is provided on the base 60 and is configured as a mechanism that switches between a fixed state in which the base 60 is fixed to the housing 22 and a release state in which the base 60 is released from the housing 22 by being operated. The fixing mechanism 70 includes a pair of upper and lower fixed shafts 71 and a clamp lever 75. The fixed shaft 71 is formed in a substantially cylindrical shape with the axial direction being the first direction, and is bridged over the upper and lower ends of the first clamp portion 62C and the second clamp portion 62D of the base 60 so as to be relatively movable in the first direction. One end of the fixed shaft 71 protrudes from the first clamp portion 62C to one side in the first direction, and a male screw is formed on one end of the fixed shaft 71. A fixing nut 72 is screwed onto one end of the fixed shaft 71 and is disposed on one side of the first clamp portion 62C in the first direction. A first fixed washer 73 is attached to one end of the fixed shaft 71, and the first fixed washer 73 is disposed between the fixed nut 72 and the first clamp portion 62C. As a result, one end of the fixed shaft 71 and the first clamp portion 62C engage with each other, restricting the movement of the fixed shaft 71 to the other axial side.

The other end of the fixed shaft 71 protrudes from the second clamping portion 62D toward the other side in the first direction. A connecting groove 71A (see FIG. 8) is formed at the other end of the fixed shaft 71, and the connecting groove 71A is open toward the other side in the first direction and penetrates in the second direction. The depth of the connecting groove 71A is set so that the bottom of the connecting groove 71A is disposed inside the second clamping portion 62D. Furthermore, a substantially annular second fixed washer 74 is attached to the other end of the fixed shaft 71, and the second fixed washer 74 is disposed adjacent to the other side in the first direction of the second clamping portion 62D. The second fixed washer 74 has a washer abutment portion 74A extending in the second direction inside the second fixed washer 74, and the washer abutment portion 74A is disposed inside the connecting groove 71A.

The clamp lever 75 is formed in a substantially Y-shaped plate shape with the second direction being the plate thickness direction and open to the other side in the first direction when viewed from the second direction, and is disposed on one side in the second direction of the first clamp part 62C and the second clamp part 62D. In addition, the clamp lever 75 is inclined toward the other side in the second direction as it approaches the other side in the first direction when viewed from above, and is curved in a substantially arc shape (see FIG. 9). The upper and lower ends of the clamp lever 75 are formed with a bent part 75A bent toward the other side in the second direction. The end of the bent part 75A toward the other side in the first direction is formed with a cam part 75B (see FIG. 9) protruding toward the other side in the second direction. The cam part 75B is inserted into the connecting groove 71A of the fixed shaft 71, and is rotatably supported by a fixed pin 76 provided on the fixed shaft 71 and having an axial direction in the up-down direction.

This allows the clamp lever 75 to be rotated between a fixed position (position shown in FIG. 9) and a released position (position shown in FIG. 11) rotated from the fixed shaft 71 to one side in the rotational direction (the direction of arrow G in FIG. 9). The outer periphery of the cam portion 75B is configured as a cam surface 75C, which is formed in a generally arc shape with the fixed pin 76 at its center when viewed from above. More specifically, the radius of the cam surface 75C from the fixed pin 76 increases as it moves toward one side in the rotational direction of the clamp lever 75.

In the fixed position of the clamp lever 75, the cam surface 75C abuts against the washer abutment portion 74A of the second fixed washer 74 and presses the washer abutment portion 74A to one side in the first direction. On the other hand, in the released position of the clamp lever 75, the cam surface 75C is disposed away from the washer abutment portion 74A to the other side in the first direction, and the pressure of the cam surface 75C against the washer abutment portion 74A is released. As a result, when the clamp lever 75 is rotated from the released position to the fixed position, the base tube portion 62 is deformed by the pressure of the cam portion 75B on the second clamp portion 62D via the second fixed washer 74, so that the second clamp portion 62D is displaced toward the first clamp portion 62C. As a result, when the clamp lever 75 is in the fixed position, a clamping force is generated that clamps the base tube portion 62 to the tube portion 22A of the housing 22, and the base 60 is fixed to the housing 22 (outer tube portion 30A) by this clamping force (hereinafter, this state is referred to as the fixed state), and when the clamp lever 75 is in the released position, the clamping force of the base tube portion 62 is released, and the fixed state of the base 60 to the housing 22 is released (hereinafter, this state is referred to as the released state). This allows the position of the base 60 relative to the housing 22 in the vertical direction to be changed by setting the fixing mechanism 70 to the released state. The part of the outer tube portion 30A that receives the clamping force is the area where the base 60 can be attached, and functions as the mounting surface for the base 60.

A lever cap 77 is provided at the tip of the clamp lever 75 (one end in the first direction), and the tip of the clamp lever 75 is covered by the lever cap 77. The tip of the clamp lever 75 is configured as a lever operating portion of the clamp lever 75, and an operator holds the lever cap 77 to rotate the clamp lever 75.

(Regarding the holding mechanism 80)
The holding mechanism 80 is configured as a mechanism for holding the base 60 in a temporarily fixed state to the housing 22 when the fixing mechanism 70 is in a released state. Here, the temporarily fixed state in this embodiment refers to a state in which the base 60 is held by the cylindrical portion 22A so that the base 60 does not fall from the cylindrical portion 22A of the housing 22 under its own weight and can move relatively in the up and down direction with respect to the cylindrical portion 22A when a lifting mechanism 90, which will be described later, is manually operated. As shown in Figures 1, 2, and 10, the holding mechanism 80 is configured to include a connecting shaft 81 and a holding spring 85 as a biasing member.

The connecting shaft 81 is formed in a substantially stepped shaft shape with the first direction as the axial direction. Specifically, a stopper portion 81A that is raised one step radially outward and an operation knob 81B that is raised one step radially outward from the stopper portion 81A are formed at one end of the connecting shaft 81, and the operation knob 81B is arranged on one side in the first direction with respect to the stopper portion 81A. Then, with the operation knob 81B and the stopper portion 81A protruding from the first clamp portion 62C of the base 60 to one side in the first direction, the connecting shaft 81 is spanned between the vertical intermediate portions of the first clamp portion 62C and the second clamp portion 62D so as to be relatively movable in the first direction and rotatable around its own axis. A first retaining washer 82 is inserted into the connecting shaft 81 from the other end side, and the first retaining washer 82 is arranged between the stopper portion 81A and the first clamp portion 62C. The stopper portion 81A engages with the first clamp portion 62C via the first retaining washer 82, limiting the movement of the connecting shaft 81 to the other axial side.

The other end of the connecting shaft 81 protrudes from the second clamp portion 62D toward the other side in the first direction, and a male thread is formed on the outer periphery of the other end of the connecting shaft 81. An adjustment nut 83 is screwed onto the other end of the connecting shaft 81 as a locking portion. In addition, a second retaining washer 84 is attached to the other end of the connecting shaft 81, and the second retaining washer 84 is disposed adjacent to one side of the adjustment nut 83 in the first direction.

The retaining spring 85 is configured as a compression coil spring and is attached to the other end of the connecting shaft 81. Specifically, one end of the retaining spring 85 is engaged with the second clamp portion 62D, and the other end of the retaining spring 85 is engaged with the adjustment nut 83 via the second retaining washer 84, so that the retaining spring 85 biases the second clamp portion 62D toward one side in the first direction and biases the other end of the connecting shaft 81 toward the other side in the first direction.

Here, as described above, one end of the connecting shaft 81 is engaged with the first clamp portion 62C, and the movement of the connecting shaft 81 toward the other end side is restricted. Therefore, when the fixing mechanism 70 is released, the first clamp portion 62C and the second clamp portion 62D are displaced in a direction approaching each other by the biasing force of the holding spring 85, and a clamping force that tightens the cylindrical portion 22A of the housing 22 is generated in the base cylindrical portion 62. Then, a frictional force is generated between the base 60 and the housing 22 by the clamping force, and the biasing force of the holding spring 85 is set so that the base 60 does not fall by its own weight due to the frictional force. In addition, when the lifting mechanism 90 described later is operated, the inner peripheral surface of the base cylindrical portion 62 of the base 60 slides on the outer peripheral surface of the outer cylindrical portion 30A of the outer case 30, and the base 60 moves vertically relative to the housing 22. In addition, the second clamp portion 62D is formed with a concave spring housing portion 62E (see FIG. 10) that is open to the other side in the first direction, and a part of the retaining spring 85 is housed in the spring housing portion 62E. In addition, by rotating the above-mentioned adjustment nut 83, the adjustment nut 83 moves relative to the axial direction of the connecting shaft 81, so that the biasing force of the retaining spring 85 can be adjusted by the adjustment nut 83.

(Regarding the lifting mechanism 90)
3 and 10 , the lifting mechanism 90 includes a first rack 92 and a second rack 94 formed on the housing 22, the connecting shaft 81 of the holding mechanism 80, and a pinion 96. That is, the connecting shaft 81 is configured as a component of both the holding mechanism 80 and the lifting mechanism 90.

The pinion 96 is formed in a generally cylindrical shape with the first direction as its axial direction, and is fixed to the axial middle portion of the connecting shaft 81 so as to be integrally rotatable therewith, and is arranged coaxially with the connecting shaft 81. The connecting shaft 81 and the pinion 96 may be integrally formed as one member. The widths of the first rack 92 and the second rack 94 along the circumferential direction of the cylindrical portion 22A of the housing 22 are set to be slightly larger than the width (axial length) of the pinion 96.

A plurality of pinion teeth 96A are formed on the outer periphery of the pinion 96, and the plurality of pinion teeth 96A are formed around the entire circumference of the pinion 96. The pinion 96 is disposed between the first clamp portion 62C and the second clamp portion 62D of the base 60, and the pinion teeth 96A are disposed in the rack groove 92A of the first rack 92 or in the rack groove 94A of the second rack 94 of the housing 22, and are configured to mesh with the rack teeth 92B or the rack teeth 94B (in the example shown in FIG. 3, the pinion teeth 96A are meshed with the rack teeth 92B).

With this arrangement, when the fixing mechanism 70 is in the released state, the connecting shaft 81 is rotated around its own axis, causing the pinion 96 to rotate relative to the first rack 92 (second rack 94), and the base 60 moves up and down relative to the housing 22. The pinion teeth 96A are disposed within the rack groove 92A (rack groove 94A). Therefore, when the base 60 moves up and down relative to the housing 22, the pinion teeth 96A engage with both longitudinal ends of the rack groove 92A (rack groove 94A), restricting the relative rotation of the base 60 with respect to the housing 22. After adjusting the lift position of the base 60, the fixing mechanism 70 is switched from the released state to the fixed state, and the base 60 is fixed in the adjusted position.

(Regarding the controller 100)
The controller 100 is accommodated inside the upper case portion 28 of the housing 22 and fixed to the upper case portion 28. The controller 100 has a control unit 101 and an inverter unit 110. The above-mentioned connector 32, motor 34, microswitch 44, encoder 48, and tact switch 54 are electrically connected to the controller 100. The control unit 101 is configured to control the operation of the motor 34 in response to the operation of the trigger 42 and the lock button 50. The control unit 101 is also configured to control the rotation speed of the motor 34 in response to the rotation position of the speed setting dial 46.

<Electrical configuration>
The electrical configuration of the electric trimmer 10 will be described with reference to the functional (circuit) block diagram of FIG.
The controller 100 has a control circuit board (not shown), and the control circuit board is equipped with a control unit 101 and an inverter unit 110. The control unit 101 has a calculation unit 102, which performs various controls such as drive control of the inverter unit 110. The calculation unit 102 is a microcomputer. The inverter unit 110 is a circuit in which switching elements 110a (six in this embodiment) are bridge-connected. The detection resistor 120 is provided in the path of the drive current of the brushless motor as the motor 34. The control circuit voltage supply circuit 130 converts the voltage of the battery 58 into a voltage suitable for the operation of the control unit 101 and supplies it to the control unit 101. The magnetic sensor 107 is, for example, a Hall element, and outputs a signal corresponding to the rotation position of the brushless motor as the motor 34.

In the control unit 101, the motor current detection circuit 103 detects the drive current of the brushless motor serving as the motor 34 from the terminal voltage of the detection resistor 120. The switch operation detection circuit 104 detects the operation of the trigger 42 serving as the operation unit by the operator. The rotor position detection circuit 105 detects the rotational position of the brushless motor serving as the motor 34 based on a signal from the magnetic sensor 107. The motor rotation speed detection circuit 106 detects the rotation speed of the brushless motor serving as the motor 34 based on a signal from the rotor position detection circuit 105. The calculation unit 102 calculates the rotation speed of the brushless motor serving as the motor 34 based on the detection result of the rotor position detection circuit 105, and outputs it to the control signal output circuit 108.

The control unit 101 changes the control state differently depending on whether the tactile switch 54 (lock button 50) as the state switching unit is operated when the brushless motor as the motor 34 is in a non-driven state or whether the tactile switch 54 (lock button 50) as the state switching unit is operated when the brushless motor as the motor 34 is in a driven state. For example, when the brushless motor as the motor 34 is in a driven state, the control unit 101 has an on-lock state in which the drive of the brushless motor as the motor 34 is maintained even if the operation of the trigger 42 as the operation unit is released, and an on-lock release state in which the drive of the brushless motor as the motor 34 is stopped by releasing the operation of the trigger 42 as the operation unit, and can exemplify control so that the on-lock state and the on-lock release state are switched based on the operation of the tactile switch 54 (lock button 50) as the state switching unit. Also, for example, the control unit 101 can exemplify control so that the on-lock state is released based on the operation of the trigger 42 as the operation unit when in the on-lock state.

(Operation of the electric trimmer 10)
Next, the operation of the electric trimmer 10 will be described with reference to the flowchart shown in FIG.

In the operation of the electric trimmer 10, in step 1 (S1), the battery 58 is attached to the battery mounting portion 28A of the housing 22, and the battery 58 is connected to the connector 32. After the battery 58 is connected to the connector 32, the process proceeds to step 2 (S2).

In step 2, the control unit 101 prohibits the motor 34 from being driven (off-lock state). After processing in step 2, the process proceeds to step 3 (S3).

In step 3, the control unit 101 determines whether or not the lock button 50 has been pressed based on the output signal of the tactile switch 54. If the lock button 50 has not been pressed in step 3 (No in step 3), the process returns to step 2. In other words, the off-lock state of the motor 34 is maintained. On the other hand, if the lock button 50 has been pressed in step 3 (Yes in step 3), the process proceeds to step 4 (S4).

In step 4, the control unit 101 sets the motor 34 in a state in which driving is permitted (an off-lock release state, also called a drive standby state of the motor 34). Then, after processing in step 4, the process proceeds to step 5 (S5).

In step 5, the control unit 101 determines whether or not the trigger 42 has been operated to the operating position based on the output signal of the microswitch 44. If the trigger 42 has been operated to the operating position in step 5 (Yes in step 5), the process proceeds to step 6.

In step 6, the control unit 101 drives the motor 34. This causes the output shaft 34A of the motor 34 to rotate around its own axis, and the operator uses the tool tip T to perform cutting on the workpiece. At this time, the control unit 101 rotates the output shaft 34A at a rotation speed that corresponds to the rotation position of the speed setting dial 46. After processing in step 6, the process proceeds to step 7 (S7).

In step 7, the control unit 101 determines whether or not the operation of the trigger 42 to the operation position is continuing based on the output signal of the microswitch 44. In step 7, if the operation of the trigger 42 to the operation position is not continuing, that is, if the trigger 42 has returned to the initial position (No in step 7), the process proceeds to step 8 (S8).

In step 8, the control unit 101 stops driving the motor 34. That is, when the operator releases the operation of the trigger 42, the control unit 101 stops driving the motor 34. After processing step 8, the process returns to step 5.

On the other hand, if the operation of the trigger 42 to the operation position is continued in step 7 (Yes in step 7), the process proceeds to step 9 (S9).

In step 9, the control unit 101 determines whether or not the lock button 50 has been pressed based on the output signal from the tactile switch 54. If the lock button 50 has not been pressed in step 9 (No in step 9), the process returns to step 7. On the other hand, if the lock button 50 has been pressed in step 9 (Yes in step 9), the process proceeds to step 10 (S10).

In step 10, the control unit 101 sets the motor 34 in a state in which the drive is maintained (on-lock state). That is, when the lock button 50 is pressed while the trigger 42 is in the operating position, the motor 34 transitions to an on-lock state in which the drive is maintained. After processing in step 10, the process proceeds to step 11 (S11).

In step 11, the control unit 101 determines whether the trigger 42 has been returned to the initial position based on the output signal of the microswitch 44. If the trigger 42 has not been returned to the initial position in step 11 (No in step 11), the process returns to step 10. In other words, if the operator continues to operate the trigger 42 to the operating position, the process returns to step 10 and the on-lock state is maintained.

On the other hand, if the trigger 42 is returned to the initial position in step 11 (Yes in step 11), the process proceeds to step 12 (S12). In other words, even if the operator releases the operation of the trigger 42, the on-lock state of the motor 34 is maintained, and the process proceeds to step 12.

In step 12, the control unit 101 determines whether or not the lock button 50 has been pressed based on the output signal of the tactile switch 54. If the lock button 50 has been pressed in step 12 (Yes in step 12), the process proceeds to step 13 (S13).

In step 13, the control unit 101 stops driving the motor 34. That is, when the lock button 50 is pressed while the motor 34 is in the on-lock state, the on-lock state of the motor 34 is released and the motor 34 stops. Then, after the processing of step 13, the process returns to step 5.

On the other hand, if the lock button 50 is not pressed in step 12 (No in step 12), the process proceeds to step 14 (S14).

In step 14, the control unit 101 determines whether or not the trigger 42 has been operated to the operating position based on the output signal of the microswitch 44. If the trigger 42 has not been operated to the operating position in step 14 (No in step 14), the process returns to step 12. That is, the on-lock state of the motor 34 is maintained. On the other hand, if the trigger 42 has been operated to the operating position in step 14 (Yes in step 14), the process proceeds to step 15 (S15).

In step 15, the control unit 101 stops driving the motor 34. That is, when the lock button 50 is not pressed and the trigger 42 is operated to the operating position again while the motor 34 is in the on-lock state, the on-lock state of the motor 34 is released and the motor 34 stops. Then, after the processing of step 15, the process proceeds to step 16 (S16).

In step 16, the control unit 101 determines whether the trigger 42 has returned to the initial position based on the output signal of the microswitch 44. If the trigger 42 has not returned to the initial position in step 16 (No in step 16), the process returns to step 15. That is, the motor 34 remains stopped. On the other hand, if the trigger 42 has returned to the initial position in step 16 (Yes in step 16), the process returns to step 5. That is, if the operator's operation of the trigger 42 is released, the process returns to step 5 with the motor 34 stopped. As a result, the trigger 42 is operated back to the operating position, and the motor 34 is driven again by the control unit 101.

On the other hand, if the trigger 42 is not operated to the operating position in step 5 (No in step 5), the process proceeds to step 17 (S17).

In step 17, the control unit 101 determines whether or not the lock button 50 has been pressed based on the output signal from the tactile switch 54. If the lock button 50 has been pressed in step 17 (Yes in step 17), the process returns to step 2. That is, the control unit 101 transitions the motor 34 from the drive standby state to the off-lock state. On the other hand, if the lock button 50 has not been pressed in step 17 (No in step 17), the process proceeds to step 18 (S18).

In step 18, the control unit 101 determines whether the lock button 50 has been pressed within a predetermined time (10 seconds in this embodiment) based on the output signal from the tactile switch 54. Also in step 18, the control unit 101 determines whether the trigger 42 has been operated to the operating position within the predetermined time based on the output signal from the microswitch 44. That is, in step 18, the control unit 101 determines whether the lock button 50 or trigger 42 has been operated within the predetermined time.

In step 18, if the lock button 50 or the trigger 42 is operated within the predetermined time (Yes in step 18), the process returns to step 5. That is, the motor 34 returns to the drive standby state. On the other hand, in step 18, if the lock button 50 or the trigger 42 is not operated within the predetermined time (No in step 18), the process returns to step 2. That is, if the lock button 50 or the trigger 42 is not operated while the motor 34 is in the drive standby state, the control unit 101 transitions the motor 34 from the drive standby state to the off-lock state.

(Action and Effect)
Next, the operation and effect of the electric trimmer 10 according to the present embodiment will be described.

In the electric trimmer 10 configured as described above, the housing 22 that constitutes the outer shell of the trimmer body 20 includes an inner case 24 having a cylindrical inner tube portion 26 and an outer case 30 that is inserted into the inner case 24, and the outer case 30 is fixed to the inner case 24. That is, the housing 22 has a double structure of the inner case 24 and the outer case 30. This increases the rigidity of the housing 22. Moreover, the outer case 30 is made of a single member that cannot be disassembled, and the base tube portion 62 of the base 60 is inserted into the outer case 30 in a detachable manner. That is, the part of the housing 22 that directly supports the base tube portion 62 is made of a single member that cannot be disassembled. Therefore, the support rigidity of the housing 22 relative to the base tube portion 62 can be increased. As a result, a suitable fixing structure relative to the base 60 can be realized.

In particular, the inner case 24 is made of resin, and the outer case 30 is made of metal. This makes it possible to reduce the weight of the cylindrical portion 22A of the housing 22 while increasing the strength of the portion that directly supports the base 60.

In addition, the outer case 30 is formed in a generally bottomed cylindrical shape that is open to the top, and the case bottom 30B of the outer case 30 is fastened to the fixing boss 26N of the inner case 24 by the fixing bolt BL. Furthermore, the fixing bolt BL and the fixing boss 26N for fixing the outer case 30 to the inner case 24 are arranged radially inward from the outer peripheral surface of the outer tube portion 30A. As a result, the size of the outer case 30 can be made smaller than that of a configuration in which, for example, the upper end of the outer case 30 protrudes radially outward from the outer tube portion 30A like the upper case portion 28 of the inner case 24, and the protruding portion is fastened to the upper case portion 28 of the inner case 24 (hereinafter, this configuration is referred to as the electric trimmer of the comparative example). As a result, the weight of the outer case 30 can be reduced, and the weight of the entire electric trimmer 10 can be reduced. Also, compared to the electric trimmer of the comparative example, there is no need to provide a fixing portion for fixing the outer case 30 to the upper case portion 28 of the inner case 24. This allows the upper case portion 28 to be made smaller, and ultimately allows the overall size of the electric trimmer 10 to be made smaller.

An upper case portion 28 is provided at the top end of the inner case 24, and the upper case portion 28 protrudes from the outer peripheral surface of the outer case 30 (outer cylinder portion 30A) when viewed from the top-bottom direction. This allows the controller 100 that drives and controls the motor 34 to be placed in the upper case portion 28, which has a relatively large cross-sectional area compared to the inner cylinder portion 26. A battery attachment portion 28A is also provided in the upper case portion 28, allowing a battery 58 to be attached to the inner case 24.

The lower end portion of the output shaft 34A is supported by a second bearing 36L, which is held by a bearing holder 26L of the inner case 24. A fixing boss 26N for fastening the outer case 30 is formed on the bearing holder 26L. This allows the outer case 30 to be fastened to the inner case 24 by utilizing the bearing holder 26L that holds the second bearing 36L. In other words, the outer case 30 can be fastened to the inner case 24 by utilizing the radially outer region of the second bearing 36L in the inner case 24.

The inner cylinder 26 of the inner case 24 includes a small diameter portion 26B and a large diameter portion 26A having a diameter larger than that of the small diameter portion 26B. The inner circumferential surface of the outer case 30 that is inserted into the inner cylinder 26 abuts against the large diameter portion 26A. This prevents the heat of the motor 34 operating in the inner cylinder 26 from being transferred to the outer case 30 by the gap 22B between the outer case 30 and the small diameter portion 26B. In addition, the inner circumferential surface of the outer case 30 abuts against the large diameter portion 26A, thereby preventing the outer case 30 from rattling when the outer case 30 is inserted into the inner case 24. Therefore, the outer case 30 can be well maintained in the inserted state on the inner case 24 while suppressing the temperature rise of the outer case 30 that functions as the gripping portion that the operator grips.

In addition, in the inner cylinder portion 26 of the inner case 24, the large diameter portion 26A constitutes the upper and lower ends of the inner cylinder portion 26, and the small diameter portion 26B constitutes the vertical middle portion of the inner cylinder portion 26. In other words, the large diameter portion 26A is disposed on both axial sides of the inner cylinder portion 26 relative to the small diameter portion 26B. This allows the outer case 30 to be supported at the axial ends of the inner cylinder portion 26. Therefore, the outer case 30 can be more effectively maintained in its inserted state on the inner case 24.

In addition, a fan 40 that rotates by driving the motor 34 is provided inside the inner case 24. Furthermore, an upper communication hole 26G and a lower communication hole 26H are formed in the large diameter portion 26A, and the upper communication hole 26G and the lower communication hole 26H communicate the gap 22B with the inside of the inner case 24. As a result, as shown in FIG. 3, when the electric trimmer 10 is operated, the cooling air AR is flowed into the inner case 24 from the intake port 28B of the inner case 24 by the air flow generated by the fan 40. The cooling air AR that flows into the inner case 24 is divided at the upper end of the inner cylinder portion 26 into cooling air AR1 that flows into the upper communication hole 26G and cooling air AR2 that flows downward inside the inner cylinder portion 26. The cooling air AR1 flows downward through the gap 22B between the small diameter portion 26B of the inner case 24 and the outer case 30, and flows into the lower end of the inner cylindrical portion 26 through the lower communication hole 26H. The cooling air AR1 and the cooling air AR2 then join at the lower end of the inner cylindrical portion 26, and are exhausted to the outside of the housing 22 through the inner exhaust port 26M and the outer exhaust port 30D. As a result, the outer case 30 can be cooled by the cooling air AR1, while the motor 34 can be cooled by the cooling air AR2. Therefore, the outer case 30 and the motor 34 can be effectively cooled.

In addition, a pair of case cutouts 30F that are open upward are formed at the upper end of the outer case 30. The trigger 42 provided on the inner case 24 is disposed in one of the case cutouts 30F, and the lock button 50 provided on the inner case 24 is disposed in the other case cutout 30F. This allows the outer case 30 to be extrapolated onto the inner case 24 by aligning the positions of the case cutouts 30F, the trigger 42, and the lock button 50. In other words, when the outer case 30 is extrapolated onto the inner case 24, the direction of the outer case 30 relative to the inner case 24 in the circumferential direction can be aligned using the case cutouts 30F, the trigger 42, and the lock button 50 as markers. Therefore, the workability when extrapolating the outer case 30 onto the inner case 24 can be improved.

The inner cylindrical portion 26 of the inner case 24 is formed with a protrusion 26K that protrudes radially outward, and the inner peripheral surface of the outer case 30 is formed with an engagement groove 30G that extends vertically and opens upward. When the outer case 30 is inserted onto the inner case 24, the protrusion 26K is inserted into the engagement groove 30G, and the protrusion 26K and the engagement groove 30G engage with each other in the circumferential direction of the outer case 30. This makes it possible to limit the relative rotation of the outer case 30 with respect to the inner case 24. Therefore, when the fixing bolt BL is screwed into the fixing boss 26N, it is possible to suppress misalignment between the fixing hole 30E and the fixing boss 26N. This improves the workability when fastening and fixing the outer case 30 to the inner case 24.

The base 60 of the electric trimmer 10 is provided with a fixing mechanism 70 that switches between a fixed state in which the base 60 is fixed to the housing 22 and a release state in which the fixed state is released. Furthermore, the base 60 is provided with a holding mechanism 80, which holds the base 60 in a provisionally fixed state to the housing 22 when the fixing mechanism 70 is in the release state. Specifically, the holding mechanism 80 holds the base 60 so that the base 60 does not fall under its own weight when the fixing mechanism 70 is in the release state. That is, the holding mechanism 80 functions as a mechanism that assists the fixing mechanism 70 when the fixing mechanism 70 is in the release state, and the holding mechanism 80 prevents the fixing force of the base 60 to the housing 22 from immediately becoming zero. As a result, when the fixing mechanism 70 is in the release state, the operator does not need to support the base 60. Therefore, a suitable fixing structure for the base 60 can be realized.

The holding mechanism 80 includes a connecting shaft 81 that connects the first clamp portion 62C and the second clamp portion 62D of the base 60, and a holding spring 85. Specifically, the connecting shaft 81 is spanned between the first clamp portion 62C and the second clamp portion 62D so as to be relatively movable in the axial direction, and one end of the connecting shaft 81 engages with the first clamp portion 62C to restrict the movement of the connecting shaft 81 to the other axial direction. The holding spring 85 is attached to the other end portion of the connecting shaft 81 and biases the second clamp portion 62D to one axial side of the connecting shaft 81 and biases the other end of the connecting shaft 81 to the other axial direction. As a result, the connecting shaft 81 and the holding spring 85 press the first clamp portion 62C and the second clamp portion 62D toward the inside of the axial direction of the connecting shaft 81, and the base tube portion 62 is deformed in a direction in which the first clamp portion 62C and the second clamp portion 62D approach each other.

More specifically, if the holding mechanism 80 is omitted in the electric trimmer 10, the pressing force of the holding spring 85 on the second clamp portion 62D is eliminated, and the second clamp portion 62D of the base 60 in the released state (see the second clamp portion 62D shown by the one-dot chain line in FIG. 11) is largely displaced to the other side in the first direction relative to the second clamp portion 62D of the base 60 in the fixed state (see the second clamp portion 62D shown by the two-dot chain line in FIG. 11). In contrast, by providing the holding mechanism 80 on the base 60, the pressing force of the holding spring 85 acts on the second clamp portion 62D, and the second clamp portion 62D of the base 60 in the released state (see the second clamp portion 62D shown by the solid line in FIG. 11) is located on one side in the first direction compared to the case where the holding mechanism 80 is omitted. Therefore, the base tube portion 62 tightens the tube portion 22A of the housing 22, and a clamping force that clamps the tube portion 22A is generated in the base 60. As a result, a frictional force is generated between the base tube portion 62 and the tube portion 22A, and this frictional force can hold the base 60 in a temporarily held state. The temporarily held state here refers to a state in which the base 60 is fixed to the extent that it can be moved by hand while preventing movement due to its own weight.

In addition, in the holding mechanism 80, an adjustment nut 83 is screwed onto the other end of the connecting shaft 81. A holding spring 85 is disposed between the second clamp portion 62D and the adjustment nut 83. This makes it possible to easily adjust the biasing force of the holding spring 85 against the second clamp portion 62D and the connecting shaft 81 by rotating the adjustment nut 83 relative to the connecting shaft 81.

The pinion 96 of the lifting mechanism 90 is provided on the connecting shaft 81 so as to rotate integrally with the connecting shaft 81, and the pinion 96 is engaged with the first rack 92 or the second rack 94 of the outer case 30. As a result, when the fixing mechanism 70 is in the released state, the base 60 can be raised and lowered relative to the housing 22 by rotating the operating knob 81B of the connecting shaft 81. In other words, the connecting shaft 81 can be configured as a common component of the holding mechanism 80 and the lifting mechanism 90. Therefore, compared to a case in which the connecting shaft 81 is not configured as a common component of the holding mechanism 80 and the lifting mechanism 90, it is possible to reduce the space required for the holding mechanism 80 and the lifting mechanism 90, and to reduce the size of the driving tool 10.

As described above, one end (stopper portion 81A) of the connecting shaft 81 engages with the first clamp portion 62C via the first retaining washer 82, restricting the movement of the connecting shaft 81 toward the other axial direction. Furthermore, the retaining spring 85 biases the other axial end of the connecting shaft 81 toward the other axial direction. As a result, a shaft retaining force for restricting the rotation of the connecting shaft 81 is generated in the connecting shaft 81 by the biasing force of the retaining spring 85. As described above, the pinion 96 is provided so as to be rotatable integrally with the connecting shaft 81, and is meshed with the first rack 92 or the second rack 94 of the outer case 30. Therefore, the shaft retaining force generated in the connecting shaft 81 can be applied to the meshing portion between the pinion 96 and the first rack 92 or the second rack 94. That is, the lifting mechanism 90 can also function as a mechanism for holding the base 60 in a provisionally fixed state to the housing 22. Therefore, the biasing force of the retaining spring 85 can be effectively utilized to hold the base 60 in a provisionally fixed state.

The first rack 92 and the second rack 94 of the lifting mechanism 90 are arranged spaced apart in the circumferential direction of the outer tube portion 30A. Therefore, the position of the base 60 when the pinion 96 is engaged with the first rack 92 (hereinafter, this position will be referred to as the first position) in the circumferential direction of the tube portion 22A and the position of the base 60 when the pinion 96 is engaged with the second rack 94 (hereinafter, this position will be referred to as the second position) can be set to different positions. Therefore, the lifting mechanism 90 can function with the base 60 placed in the first position or the second position depending on the work style of the worker. Therefore, the workability for the worker can be improved.

As described above, a plurality of racks (first rack 92 and second rack 94) are formed on the outer cylindrical portion 30A in the circumferential direction of the cylindrical portion 22A of the housing 22. Furthermore, the width of each of the first rack 92 and second rack 94 along the circumferential direction of the cylindrical portion 22A is set to be greater than the width of the pinion 96. For this reason, the total length of the rack along the circumferential direction of the cylindrical portion 22A (the sum of the widths of the first rack 92 and the second rack 94) is set to be at least twice the width of the pinion 96. That is, the "total length of the rack along the circumferential direction of the cylindrical portion" in the present invention refers to the sum of the widths of the plurality of racks (first rack 92 and second rack 94) when a plurality of racks (first rack 92 and second rack 94) are formed on the outer cylindrical portion 30A as in this embodiment. As a result, as described above, the position of the base 60 in the circumferential direction of the outer cylindrical portion 30A can be changed to use the lifting mechanism 90.

In addition, in this embodiment, the trigger 42 is provided on the outer tube portion 30A (gripping portion), so that the motor 34 can be quickly turned on and off when working with one hand. Even if the gripping state is released during the operation of the trigger 42, the motor 34 stops, so that damage to the workpiece can be suppressed. Furthermore, since the motor 34 can be maintained in the on state by operating the lock button 50, the work can be continued even if the operating force on the trigger 42 is released, and fatigue during work can be reduced. In addition, the off-lock control can be executed so that the motor 34 does not drive even if the trigger 42 is operated unless the lock button 50 is operated, so that even if a foreign object contacts the trigger 42 during non-work, the motor 34 does not drive, and adverse effects such as wasteful energy consumption can be suppressed. Furthermore, by configuring the transition to the on-lock state to be performed by the lock button 50 that similarly releases the off-lock state, the number of parts of the control switch can be reduced, and the transition from the off-lock release to the on-lock state can be performed in the same gripping state. In particular, this embodiment allows the user to transition from the off-lock release to the on-lock state by using two fingers while holding the device, greatly improving operability.

In this embodiment, the fixing bolt BL is inserted from below into the fixing hole 30E of the outer case 30 and screwed into the fixing boss 26N of the inner case 24, thereby fastening and fixing the outer case 30 to the inner case 24. In other words, the fixing bolt BL extends in the vertical direction. Alternatively, for example, the fixing bolt BL may be disposed at the lower end of the tubular portion 22A so as to extend in the first or second direction, and the inner case 24 and the outer case 30 may be fastened and fixed.

In addition, in the holding mechanism 80 of this embodiment, a clamping force that clamps the cylindrical portion 22A of the housing 22 is generated in the base 60 to hold the base 60 in a temporarily fixed state to the housing 22, but the mechanism for holding the base 60 in a temporarily fixed state is not limited to this. For example, although not shown in the figures, a high-friction member with a relatively high friction coefficient may be provided on at least one of the outer peripheral surface of the outer cylindrical portion 30A of the outer case 30 and the inner peripheral surface of the base cylindrical portion 62 of the base 60, and the base 60 may be held in a temporarily fixed state by the frictional force generated between the base cylindrical portion 62 and the outer cylindrical portion 30A. In addition, the retaining spring 85 is positioned on the outer periphery of the connecting shaft 81 to bring the first clamp portion 62C and the second clamp portion 62D close to each other, but it may be provided on the fixed shaft 71. For example, the fixed pin 76 may be enlarged in the axial direction, and the retaining spring 85 may be interposed between the fixed pin 76 and the second fixed washer 74 to apply a biasing force to the fixed pin 76 and the second fixed washer 74.

For example, as shown in FIG. 14, a retaining spring 140 and a pressing member 142 may be provided as a biasing member on one of the outer tube portion 30A and the base tube portion 62 to generate a frictional force between the outer tube portion 30A and the base tube portion 62, and the base 60 may be held in a provisionally fixed state by the frictional force (in the example shown in FIG. 14, the retaining spring 140 and the pressing member 142 are provided on the base tube portion 62). Specifically, a recess that is open to the outer tube portion 30A side is formed on the base tube portion 62, and the retaining spring 140 and the pressing member 142 are disposed in the recess. The retaining spring 140 is configured as a compression coil spring and presses the pressing member 142 toward the outer tube portion 30A side. As a result, a frictional force is generated between the pressing member 142 and the outer tube portion 30A, and the base 60 can be held in a provisionally fixed state. Although the material of the pressing member 142 is not specified, for example, the holding force against the base 60 can be further increased by using an elastic material such as rubber.

In addition, in this embodiment, two racks (first rack 92 and second rack 94) are formed on the outer tube portion 30A of the housing 22, but three or more racks may be formed on the outer tube portion 30A, or one rack may be formed on the outer tube portion 30A. When one rack is formed on the outer tube portion 30A, the width of the rack along the circumferential direction of the tube portion 22A is set to more than twice the width of the pinion 96. For example, the width of the rack is set to 1/2 the entire circumference of the outer tube portion 30A. As a result, even in this case, the entire length of the rack along the circumferential direction of the tube portion 22A is set to more than twice the width of the pinion 96. Therefore, even if one rack is formed on the outer tube portion 30A, the position of the base 60 in the circumferential direction of the outer tube portion 30A can be changed by the lifting mechanism 90.

In addition, in this embodiment, the first rack 92 and the second rack 94 are formed on the housing 22, and the pinion 96 is provided on the base 60, but the pinion 96 may be provided on the housing 22, and the first rack 92 and the second rack 94 may be formed on the base 60.

10 Electric trimmer (working machine)
22 Housing 22A Cylinder portion 34 Motor 34A Output shaft 42 Trigger (operation portion)
50 Lock button (state switching part)
60 Base 62 Base cylinder portion (outer insertion portion)
62C First clamp portion 62D Second clamp portion 70 Fixing mechanism 80 Holding mechanism 81 Connecting shaft 81B Operation knob 82 First holding washer 83 Adjustment nut (locking portion)
85 Retaining spring (biasing member)
90 Lifting mechanism (position changing mechanism)
92 1st rack (rack)
94 2nd Rack (Rack)
96 Pinion 101 Control section

Claims (12)

A housing having a cylindrical portion;
a motor accommodated in the housing;
an output shaft that is rotated by the motor and to which a tool tip can be attached;
a base including: an outer insertion part having an abutment surface capable of abutting against a workpiece , the outer insertion part being fitted onto the cylindrical part and having a cylindrical shape with a portion open radially outward; a first clamp part constituting one circumferential end of the outer insertion part; and a second clamp part constituting the other circumferential end of the outer insertion part;
a fixing mechanism that is provided on the base and that is operated to switch between a fixed state in which the first clamp portion and the second clamp portion are brought closer to each other to clamp the outer insertion portion to the cylindrical portion and fix the base to the housing, and a release state in which the first clamp portion and the second clamp portion are separated from each other to release the fixed state of the base to the housing; and
a holding mechanism provided on the base and configured to hold the base in a temporarily fixed state to the housing when the fixing mechanism is in a released state;
Equipped with
The fixing mechanism includes a clamp lever that is operable by an operator and is rotatable between a fixing position and a release position,
the clamp lever has a cam portion that presses the first clamp portion when located at the fixed position, thereby bringing the base into the fixed state, and that releases the pressure on the first clamp portion when located at the released position, thereby bringing the base into the released state,
the holding mechanism has a biasing member that generates a frictional force between the cylindrical portion and the base when the clamp lever is located at the release position, thereby holding the base in a temporarily fixed state,
The base in the temporarily fixed state is fixed to the housing so as to be movable by an operator's hand while being prevented from falling off the housing due to its own weight . The work machine according to claim 1 , wherein, when the fixing mechanism is in a released state, the biasing member biases the first clamp portion and the second clamp portion in a direction in which they approach each other, thereby holding the base in a temporarily fixed state. The holding mechanism includes:
a connecting shaft that is stretched across the first clamp portion and the second clamp portion so as to be relatively movable in an axial direction;
the biasing member attached to the connecting shaft and biasing the first clamp portion and the second clamp portion in a direction to bring them closer to each other;
The work machine according to claim 2, further comprising: one end of the connecting shaft is engaged with the first clamp portion to limit the movement of the connecting shaft in the other axial direction,
4. The work machine according to claim 3, wherein the biasing member biases the second clamp portion toward one axial side of the connecting shaft and biases the connecting shaft toward the other axial side. 5. The work machine according to claim 3, wherein the biasing member is configured as a compression coil spring. a locking portion is provided at the other end of the connecting shaft and is connected to the connecting shaft so as to be movable relative to the connecting shaft in an axial direction,
5. The work machine according to claim 3 or claim 4, wherein one end of the biasing member is engaged with the second clamp portion, the other end of the biasing member is engaged with the locking portion, and the locking portion moves relative to the axial direction of the connecting shaft, thereby changing the biasing force of the biasing member against the second clamp portion and the connecting shaft. a position changing mechanism that is provided on the base and the housing and that is manually operated to change a relative position of the base with respect to the housing in the axial direction of the cylindrical portion;
A work machine as described in any one of claims 3 to 5, wherein the position change mechanism is activated when the fixing mechanism is in the released state, so that the base moves relative to the housing while maintaining a temporary holding state of the holding mechanism relative to the base. A housing having a cylindrical portion;
a motor accommodated in the housing;
an output shaft that is rotated by the motor and to which a tool tip can be attached;
a base that is fitted onto the cylindrical portion and has a contact surface that can contact the workpiece;
a fixing mechanism that is provided on the base and that is operated to switch between a fixed state in which the base is fixed to the housing and a release state in which the fixed state of the base to the housing is released; and
a holding mechanism provided on the base and configured to hold the base in a temporarily fixed state to the housing when the fixing mechanism is in a released state;
Equipped with
the holding mechanism holds the base in a temporarily fixed state by a frictional force generated between the cylindrical portion and the base,
The base is
An outer insertion part that is inserted into the cylindrical part and has a cylindrical shape with a portion open radially outward;
A first clamp portion constituting one circumferential end portion of the outer insertion portion;
A second clamp portion constituting the other circumferential end portion of the outer insertion portion;
The present invention relates to a method for manufacturing a computer-implemented ...
the fixing mechanism is configured to connect the first clamp portion and the second clamp portion, and to bring the first clamp portion and the second clamp portion closer to each other when switching from the released state to the fixed state, thereby clamping the outer insertion portion to the cylindrical portion,
When the fixing mechanism is in a released state, the first clamp portion and the second clamp portion are displaced in a direction approaching each other by the holding mechanism, and the base is held in a provisionally fixed state.
The holding mechanism includes:
a connecting shaft that is stretched across the first clamp portion and the second clamp portion so as to be relatively movable in an axial direction;
a biasing member attached to the connecting shaft and biasing the first clamp portion and the second clamp portion in a direction to bring them closer to each other;
Including,
a position changing mechanism that is provided on the base and the housing and that is manually operated to change a relative position of the base with respect to the housing in the axial direction of the cylindrical portion;
When the position change mechanism is activated in a released state of the fixing mechanism, the base moves relative to the housing while maintaining a temporary holding state of the holding mechanism with respect to the base,
An operation knob is provided on one end of the connecting shaft,
The operating machine has a position changing mechanism that is actuated by rotating the connecting shaft with the operating knob. 9. The work machine according to claim 7, wherein the position changing mechanism is provided on the housing and the base so as to be capable of changing a position of the base in a circumferential direction of the cylindrical portion. The position changing mechanism includes:
a rack provided on one of the cylindrical portion and the base and extending in an axial direction of the cylindrical portion;
a pinion provided on the other of the cylindrical portion and the base and meshing with the rack;
It is composed of
10. The work machine according to claim 9, wherein a total length of the rack along a circumferential direction of the cylindrical portion is set to be at least twice as long as a width of the pinion. The work machine according to claim 10, wherein a plurality of the racks are formed in the circumferential direction of the cylindrical portion. A control unit for controlling the operation of the motor;
an operation unit for driving or non-driving the motor;
a state switching unit that is operable by an operator to change a control state of the control unit with respect to the motor;
Equipped with
A work machine described in any one of claims 1 to 11, wherein the control unit changes the control state differently between when the state switching unit is operated while the motor is in the non-driven state and when the state switching unit is operated while the motor is in the driven state.

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