JP7528746B2 - 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, because there is only one lever provided on the cylindrical portion of the base, the force acting from the lever on the cylindrical portion of the base tends to be concentrated at one location on the cylindrical portion. Also, for example, if the base is made of resin, that portion of the cylindrical portion of the base tends to bend significantly. This may result in the base being unable to be stably fixed.

Taking the above into consideration, the present invention aims to provide a work machine that can stably fix the base.

One or more embodiments of the present invention include a housing having a cylindrical portion, a prime mover accommodated in the housing, an output shaft that is rotated by the prime mover and to which a tool bit can be attached, a base having a cylindrical outer insertion portion that is outer inserted into the cylindrical portion, and a fixing mechanism having a pair of fixing force applying portions that are provided on the outer insertion portion and that apply a fixing force to fix the outer insertion portion to the cylindrical portion when operated , the outer insertion portion including a first chuck portion that constitutes one circumferential end of the outer insertion portion, a second chuck portion that constitutes the other circumferential end of the outer insertion portion, and a slit between the first chuck portion and the second chuck portion in the circumferential direction of the outer insertion portion. the fixing mechanism has a pair of fixed shafts, one end of which engages with the first chuck portion and the other end of which protrudes from the second chuck portion toward the other axial side, a pair of cam portions connected to the other end of the fixed shaft, and a pair of the fixing force application portions provided on the other end of the fixed shaft and pressed by the cam portions to input the fixing force to the second chuck portion, the pair of the fixing force application portions being arranged apart in the axial direction of the extrapolation portion and inputting the fixing force to the second chuck portion by pressing the second chuck portion toward the first chuck portion, thereby moving the second chuck portion closer to the first chuck portion .

In one or more embodiments of the present invention, the fixing mechanism has an operating lever that is configured to be operable, and the operating lever connects a pair of the cam portions to the work machine.

In one or more embodiments of the present invention, a connecting groove is formed at the other end of the fixed shaft, which is open toward the other axial side of the fixed shaft, and the cam portion is connected to the fixed shaft inside the connecting groove, and the fixing force applying portion has an abutment portion disposed inside the connecting groove and configured to be able to abut against the cam portion, and a pressing portion that is inserted onto the fixed shaft, connected to the abutment portion, and presses the second chuck portion toward the first chuck portion.

In one or more embodiments of the present invention, the extrapolation section is provided with a position change mechanism between the pair of fixed shafts, and the axial position of the base relative to the tubular section is changed by operating the position change mechanism.

In one or more embodiments of the present invention , the fixing force applying portion is a working machine that generates a fixing force on the extrapolated portion via rigid members provided on one axial side portion and the other axial side portion of the extrapolated portion in the first chuck portion and the second chuck portion .

In one or more embodiments of the present invention, the rigid member is a work machine having a first rigid member arranged on one axial side portion of the outer insertion portion of the first chuck portion and the second chuck portion , and a second rigid member arranged on the other axial side portion of the outer insertion portion of the first chuck portion and the second chuck portion, spaced apart from the first rigid member.

According to one or more embodiments of the present invention, the base can be stably fixed.

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). 9 is an exploded perspective view showing a state in which a fixing washer and a clamp lever of the fixing mechanism shown in FIG. 8 are removed from a fixed shaft. FIG. 11 is a cross-sectional view of the holding mechanism shown in FIG. 1 as viewed from above (cross-sectional view taken along line 11-11 in FIG. 1). 12 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. 11 . 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. 3 is a side view showing a first modified example of the fixing mechanism shown in FIG. 2 as viewed from one side in the second direction. FIG. 4 is a side view showing a second modification of the fixing mechanism shown in FIG. 2 as viewed from one side in the second direction. FIG. 17 is a cross-sectional view of the fixing mechanism of Modification 2 shown in FIG. 16 as viewed from one side in the second direction.

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, 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 as a prime mover, a trigger 42, a speed setting dial 46, and a lock button 50.

<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 cylindrical shape with a bottom that is open to the bottom. Specifically, the inner case 24 includes an upper case portion 28 that forms the upper end portion 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 to one side 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 portions at the portions on one side and the other side in the second direction. Specifically, the upper communication hole 26G is disposed 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, three lower communication holes 26H (see Figures 3, 5, and 7 (A)) are formed at the boundary portion between the lower large diameter portion 26A and the small diameter portion 26B at the portions on 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. At the one side and the other side of the second direction of the bearing holder 26L, a plurality of inner exhaust ports 26M (five in this embodiment) are formed. Specifically, three inner exhaust ports 26M are formed at the one side of the second direction of the bearing holder 26L, and two inner exhaust ports 26M are formed at the other side of the second direction of the bearing holder 26L. 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 is formed with a plurality of fixing bosses 26N (four in this embodiment) 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 for mounting 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 connected 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. The fixing bolts BL 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.

A pair of case recesses 30F are formed at the upper end of the outer case 30 at positions corresponding to the enlarged diameter protrusions 26D of the inner case 24. The case recesses 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 positioned 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.

An engagement groove 30G (see FIG. 3) is formed on the inner peripheral surface at the upper end of the outer tube portion 30A 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 pair of first and second racks 92 and 94 constituting a lifting mechanism 90 (described later) are formed on the outer periphery of the outer tube portion 30A. 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 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, and the second bearing 36L is held by a 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. The collect chuck 38 corresponds to the tool holding unit of the present invention.

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 cooling air to flow into the inner case 24 from the intake port 28B, and is also configured 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 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 chuck portion 62C is provided at one circumferential end of the base tube portion 62, and a second chuck portion 62D is provided at the other circumferential end of the base tube portion 62. The first chuck portion 62C and the second chuck portion 62D are formed in a substantially long block shape with the vertical direction as the longitudinal direction, and extend downward while protruding to one side in the second direction. The first chuck portion 62C and the second chuck portion 62D correspond to the chuck portion in this invention. The chuck portion is a part of the base 60 that protrudes radially outward from the base tube portion 62 and extends in the axial 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 and 8 to 10, 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 when it is operated. The fixing mechanism 70 includes a pair of upper and lower fixed shafts 71 and a clamp lever 75 as an operating lever. The fixed shaft 71 is formed in a substantially cylindrical shape with the axial direction being in the first direction, and is bridged over the upper and lower ends of the first chuck portion 62C and the second chuck 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 chuck portion 62C to one side in the first direction, and a male screw is formed on one end of the fixed shaft 71. A fixed nut 72 is screwed onto one end of the fixed shaft 71 and is disposed on one side of the first chuck portion 62C in the first direction. As a result, the fixed nut 72 constitutes one end of the fixed shaft 71.

An engagement washer 73 (broadly speaking, an element that can be understood as an engagement member) is attached to one end of the fixed shaft 71, and the engagement washer 73 is disposed between the fixed nut 72 and the first chuck portion 62C. This causes one end of the fixed shaft 71 to engage with the first chuck portion 62C, restricting the movement of the fixed shaft 71 to the other axial direction.

The other end of the fixed shaft 71 protrudes from the second chuck portion 62D toward the other side in the first direction. A connecting groove 71A (see Figures 8 and 10) is formed in the center of the other end of the fixed shaft 71 in the up-down direction, and the connecting groove 71A is open to the other side in the first direction and penetrates in the second direction. The groove depth of the connecting groove 71A is set so that the bottom of the connecting groove 71A is positioned inside the second chuck portion 62D.

The other end of the fixed shaft 71 is fitted with a fixed washer 74 as a fixing force imparting part, and the fixed washer 74 is arranged adjacent to the other side of the second chuck part 62D in the first direction. That is, a pair of fixed washers 74 are arranged spaced apart in the vertical direction and adjacent to the other side of the first direction of both longitudinal ends of the second chuck part 62D. The fixed washer 74 includes a washer abutment part 74A (see FIG. 10) as an abutment part extending in the second direction, and a washer pressing part 74B (see FIG. 10) formed in an annular shape and connected to both ends of the washer abutment part 74A as a pressing part. The washer abutment part 74A is arranged inside the connecting groove 71A, and the washer pressing part 74B is fitted onto the other end of the fixed shaft 71. The engagement washer 73 and the fixed washer 74 correspond to the rigid member of the present invention.

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 chuck portion 62C and the second chuck portion 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 portion 75A bent toward the other side in the second direction. The end of the bent portion 75A toward the other side in the first direction is formed with a cam portion 75B (see FIG. 9) protruding toward the other side in the second direction. The cam portion 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. 12) rotated from the fixed shaft 71 to one side in the rotation 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 rotation 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 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 pressing force of the cam portion 75B on the second chuck portion 62D via the fixed washer 74, so that the second chuck portion 62D is displaced toward the first chuck portion 62C. As a result, when the clamp lever 75 is in the fixed position, a clamping force is generated that causes the base tube portion 62 to clamp the tube portion 22A of the housing 22, and the base 60 is fixed to the housing 22 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.

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 11, the holding mechanism 80 includes a connecting shaft 81 and a holding spring 85.

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 chuck portion 62C of the base 60 to one side in the first direction, the connecting shaft 81 is spanned between the vertical middle portions of the first chuck portion 62C and the second chuck 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 chuck portion 62C. The stopper portion 81A engages with the first chuck 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 chuck 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. 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 chuck 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 chuck 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 chuck portion 62C, and the movement of the connecting shaft 81 toward the other end side is restricted. Therefore, when the fixing mechanism 70 is in the released state, the first chuck portion 62C and the second chuck portion 62D are displaced in a direction approaching each other by the biasing force of the holding spring 85, and a clamping force that clamps 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. The second chuck portion 62D is formed with a concave spring housing portion 62E (see FIG. 11) 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 aforementioned 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 11 , 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 chuck portion 62C and the second chuck 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 driving 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 driving 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 rotational position of the motor 34.

In the control unit 101, the motor current detection circuit 103 detects the drive current of 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 by the operator. The rotor position detection circuit 105 detects the rotational position of 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 motor 34 based on the signal from the rotor position detection circuit 105. The calculation unit 102 calculates the rotation speed of 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) is operated when the motor 34 is in a non-driven state or when the tactile switch 54 (lock button 50) is operated when the motor 34 is in a driven state. For example, when the motor 34 is in a driven state, the control unit 101 has an on-lock state in which the motor 34 is maintained in drive even if the operation on the trigger 42 is released, and an on-lock release state in which the motor 34 is stopped in drive by releasing the operation on the trigger 42, and can exemplify control so that the on-lock state and the on-lock release state are switched based on the operation on the tactile switch 54 (lock button 50). Also, for example, the control unit 101 can exemplify control so that the on-lock state is released based on the operation on the trigger 42 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.

The electric trimmer 10 configured as described above 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. The fixing mechanism 70 includes a pair of upper and lower fixed shafts 71 that are spanned between the first chuck portion 62C and the second chuck portion 62D of the base 60, a pair of cam portions 75B that are connected to the other end of the fixed shafts 71, and a pair of fixed washers 74 that are provided on the other end of the fixed shafts 71.

When the clamp lever 75 of the fixing mechanism 70 is rotated from the release position to the fixed position, the cam surface 75C of the cam portion 75B abuts against the washer abutment portion 74A of the fixed washer 74 and presses the washer abutment portion 74A to one side in the first direction. As a result, the washer pressing portion 74B of the fixed washer 74 presses the second chuck portion 62D to one side in the first direction. Also, when the clamp lever 75 rotates to the fixed position, the amount of pressure applied by the cam portion 75B to the fixed washer 74 increases as the clamp lever 75 is rotated. Meanwhile, one end of the fixed shaft 71 engages with the first chuck portion 62C via the fixed nut 72 and the engagement washer 73, restricting the movement of the fixed shaft 71 to the other axial side. Therefore, when the clamp lever 75 is in the fixed position, a pressing force (corresponding to the fixing force of the present invention) is applied from the fixed washer 74 to the second chuck portion 62D. This displaces the second chuck portion 62D toward the first chuck portion 62C, and the base tube portion 62 deforms. As a result, a clamping force that tightens the tube portion 22A of the housing 22 is generated in the base tube portion 62, and the base 60 is fixed to the housing 22 by this clamping force.

Here, in the fixing mechanism 70, the fixed shaft 71 is bridged across the upper and lower ends of the first chuck portion 62C and the second chuck portion 62D of the base 60, and the cam portion 75B and the fixed washer 74 are provided on each of the pair of fixed shafts 71. This allows both longitudinal ends of the first chuck portion 62C and the second chuck portion 62D to be clamped by the fixing mechanism 70. In other words, when the fixing mechanism 70 is in the fixed state, the pressing force input from the fixed washer 74 to the second chuck portion 62D for deforming the base tube portion 62 acts on the upper portion (upper end) and lower portion (lower end) of the second chuck portion 62D, respectively. Therefore, for example, the base tube portion 62 can be deformed well over the entire axial direction compared to a configuration in which the pressing force applied from the fixing washer 74 to the second chuck portion 62D is applied to one location in the longitudinal middle portion of the second chuck portion 62D (hereinafter, the electric trimmer with this configuration is referred to as the electric trimmer of the comparative example). As a result, compared to the electric trimmer of the comparative example, the clamping force for clamping the tube portion 22A of the base tube portion 62 can be applied uniformly in the axial direction of the base tube portion 62. Therefore, the base 60 can be stably fixed to the housing 22. Particularly in this embodiment, the pressing force acting on the upper and lower portions of the second chuck portion 62D acts in the range of the upper 30% and the lower 30% of the extension range of the second chuck portion 62D, so that the risk of insufficient fixing force at the upper and lower ends of the second chuck portion 62D can be reduced. Furthermore, if the lower part of the second chuck part 62D is positioned below the lower end of the inner tube part 26, there is a risk that the fixing force for the lower part of the second chuck part 62D will be insufficient, but the attenuation of the fixing force can be compensated for by the pressing force acting on the upper part of the second chuck part 62D. In this embodiment, a pair of fixed shafts 71 generate pressing forces on the upper part (upper end) and lower part (lower end) of the second chuck part 62D, but it is also possible to provide a means for generating pressing forces on the upper and lower parts of the second chuck part 62D while using a single fixed shaft.

The fixing mechanism 70 also has a clamp lever 75, which has a pair of upper and lower cam portions 75B. In other words, the pair of cam portions 75B connected to the fixed shaft 71 are connected by the clamp lever 75. This allows the pair of cam portions 75B to be operated simultaneously by rotating the clamp lever 75. Therefore, even if the fixing mechanism 70 is configured to include a pair of fixed shafts 71, a pair of fixed washers 74, and a pair of cam portions 75B, it is possible to reduce the complexity for the operator when operating the fixing mechanism 70.

The other end of the fixed shaft 71 is formed with a connecting groove 71A that is open toward the other axial side, and the cam portion 75B is disposed within the connecting groove 71A and rotatably connected to the fixed shaft 71. This makes it possible to prevent the fixing mechanism 70 from becoming larger in the vertical direction compared to a configuration in which, for example, the connecting groove 71A is omitted from the fixed shaft 71 and a pair of cam portions 75B are disposed on both vertical sides of the fixed shaft 71 to connect the cam portions 75B to the fixed shaft 71.

The fixed washer 74 is configured to include a washer abutment portion 74A extending in the second direction, and a washer pressing portion 74B formed in an annular shape and connected to both longitudinal ends of the washer abutment portion 74A. The washer abutment portion 74A is inserted into the connecting groove 71A of the fixed shaft 71 and configured to be able to abut against the cam portion 75B. The washer pressing portion 74B is inserted onto the fixed shaft 71 and configured to be able to press the second chuck portion 62D. As a result, the pressing force of the cam portion 75B on the fixed washer 74 is input to the center of the fixed washer 74, and the input pressing force is uniformly transmitted in the circumferential direction of the washer pressing portion 74B, allowing the washer pressing portion 74B to press the second chuck portion 62D.

The base tube portion 62 is provided with a connecting shaft 81 between a pair of upper and lower fixed shafts 71, and a pinion 96 constituting the lifting mechanism 90 is provided on the connecting shaft 81 so as to be able to rotate integrally therewith. The pinion 96 meshes with a first rack 92 or a second rack 94 formed on the outer case 30. This makes it possible to provide a lifting mechanism 90 for changing the position of the base 60 relative to the housing 22 by effectively utilizing the area between the pair of upper and lower fixed shafts 71.

The holding mechanism 80 includes a connecting shaft 81 that connects the first chuck portion 62C and the second chuck portion 62D of the base 60, and a holding spring 85. Specifically, the connecting shaft 81 is spanned between the first chuck portion 62C and the second chuck portion 62D so as to be movable relative to one another in the axial direction, and one end of the connecting shaft 81 engages with the first chuck 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 chuck 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 side. As a result, the connecting shaft 81 and the retaining spring 85 press the first chuck portion 62C and the second chuck portion 62D inward in the axial direction of the connecting shaft 81, deforming the base tube portion 62 in a direction in which the first chuck portion 62C and the second chuck 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 chuck portion 62D is eliminated, and the second chuck portion 62D of the base 60 in the released state (see the second chuck portion 62D shown by the one-dot chain line in FIG. 12) is largely displaced to the other side in the first direction relative to the second chuck portion 62D of the base 60 in the fixed state (see the second chuck portion 62D shown by the two-dot chain line in FIG. 12). In contrast, by providing the holding mechanism 80 on the base 60, the pressing force of the holding spring 85 acts on the second chuck portion 62D, and the second chuck portion 62D of the base 60 in the released state (see the second chuck portion 62D shown by the solid line in FIG. 12) is positioned to 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 temporary holding state.

(First modified example of the fixing mechanism 70)
Hereinafter, a first modified example of the fixing mechanism 70 will be described with reference to FIG. 15. The first modified example of the fixing mechanism 70 is configured similarly to the fixing mechanism 70 of the present embodiment, except for the following points. That is, in the first modified example of the fixing mechanism 70, a pair of clamp levers 75 are provided corresponding to a pair of fixed shafts 71 (not shown in FIG. 15). The clamp levers 75 are formed in a substantially rectangular shape with the first direction as the longitudinal direction when viewed from one side in the second direction. In addition, although not shown, the connecting groove 71A is omitted in the fixed shaft 71, and the cam portions 75B of the clamp levers 75 are respectively arranged on the upper and lower sides of the other end of the fixed shaft 71, and are rotatably connected to the fixed shaft 71 by the fixed pin 76 with the up-down direction as the axial direction. In addition, the washer abutment portion 74A is omitted in the fixed washer 74.

Then, by rotating the upper and lower clamp levers 75 from the release position to the fixed position, both longitudinal ends of the first chuck portion 62C and the second chuck portion 62D of the base tube portion 62 can be clamped by the fixing mechanism 70, as in this embodiment. This allows the clamping force that clamps the tube portion 22A of the base tube portion 62 to be applied uniformly in the axial direction of the base tube portion 62. Therefore, even in the first modified example of the fixing mechanism 70, the base 60 can be stably fixed to the housing 22.

In addition, in the first modified example of the fixing mechanism 70, clamp levers 75 are provided in correspondence with each pair of fixed shafts 71. This allows fine adjustment of the pressing force applied from the upper fixed washer 74 to the second chuck portion 62D and the pressing force applied from the lower fixed washer 74 to the second chuck portion 62D.

In the first modified example, the fixing mechanism 70 has two of each of the fixed shaft 71, the cam portion 75B, the fixed washer 74, and the clamp lever 75, but the fixing mechanism 70 may have three or more of these components.

(Second modified example of the fixing mechanism 70)
Hereinafter, a second modified example of the fixing mechanism 70 will be described with reference to Figs. 16 and 17. The second modified example of the fixing mechanism 70 is configured similarly to the fixing mechanism 70 of the present embodiment, except for the following points. That is, in the second modified example of the fixing mechanism 70, instead of the pair of fixed shafts 71, the connecting shaft 81 of the holding mechanism 80 is configured as the fixed shaft of the fixing mechanism 70. In the second modified example of the fixing mechanism 70, the clamp lever 75 is formed in a substantially rectangular shape with the first direction as the longitudinal direction when viewed from one side in the second direction. The cam portions 75B of the clamp lever 75 are disposed on the upper and lower sides of the other end of the fixed shaft 71, respectively, and are rotatably connected to the fixed shaft 71 by a fixed pin 76 with the up-down direction as the axial direction.

In the second modification, an engagement washer 173 is provided at one end of the connecting shaft 81 instead of the engagement washer 73. The engagement washer 173 is formed in a substantially rectangular plate shape with the first direction as the plate thickness direction and the vertical direction as the longitudinal direction. One end portion of the connecting shaft 81 is inserted into the longitudinal middle portion of the engagement washer 173, and the stopper portion 81A of the connecting shaft 81 and the engagement washer 173 are engaged. In addition, a restricting portion 173A is formed at both longitudinal ends of the engagement washer 173, and the restricting portion 173A protrudes toward the other side in the first direction and abuts against the upper end and lower end of the first chuck portion 62C. This restricts the movement of the connecting shaft 81 toward the other side in the second direction.

In the second modification, instead of the fixed washer 74, a fixed washer 174 is provided as a pressing member at the other end of the connecting shaft 81. The fixed washer 174 is formed in a substantially rectangular plate shape with the first direction as the plate thickness direction and the vertical direction as the longitudinal direction. The other end portion of the connecting shaft 81 is inserted into the longitudinal middle part of the fixed washer 174, and the fixed washer 174 is disposed between the second chuck portion 62D and the cam portion 75B of the clamp lever 75. When the fixing mechanism 70 is in the fixed state, the cam portion 75B presses the fixed washer 174 to one side in the first direction.

In addition, pressing portions 174A are formed at both longitudinal ends of the fixed washer 174 as fixing force applying portions, and the pressing portions 174A protrude to one side in the first direction and are disposed adjacent to the other side in the first direction of the upper and lower ends of the second chuck portion 62D.

When the clamp lever 75 of the fixing mechanism 70 is rotated from the release position to the fixed position, the cam portion 75B presses the fixed washer 174 to one side in the first direction. As a result, the pair of pressing portions 174A of the fixed washer 174 press the upper end and the lower end of the second chuck portion 62D to one side in the first direction. Therefore, even in the second embodiment, both longitudinal ends of the first chuck portion 62C and the second chuck portion 62D of the base tube portion 62 can be sandwiched by the fixing mechanism 70. This allows the clamping force that clamps the tube portion 22A of the base tube portion 62 to be applied uniformly in the axial direction of the base tube portion 62. Therefore, even in the second modification of the fixing mechanism 70, the base 60 can be stably fixed to the housing 22.

In addition, in variant 2 of the fixing mechanism 70, the connecting shaft 81 of the holding mechanism 80 is configured as the fixed shaft of the fixing mechanism 70. This reduces the number of parts and contributes to reducing the cost of the electric trimmer 10.

In this embodiment, the fixing mechanism 70 applies a pressing force to the second chuck portion 62D, causing a clamping force that tightens the tubular portion 22A of the housing 22 to act on the base tubular portion 62, but the configuration of the fixing mechanism 70 is not limited to this. For example, although not shown in the figures, the fixing mechanism 70 may be configured as a toggle mechanism, and the fixing force applying portion that applies the fixing force to fix the tubular portion 22A may be arranged spaced apart in the vertical direction.

10 Electric trimmer (working machine)
22 Housing 22A Cylinder portion 34 Motor (prime mover)
34A Output shaft 60 Base 62 Base cylinder portion (outer insertion portion)
62A: Slit 62C: First chuck portion 62D: Second chuck portion 70: Fixing mechanism 71: Fixed shaft 71A: Connecting groove 74: Fixed washer (fixing force applying portion)
74A Washer contact part (contact part)
74B Washer pressing part (pressing part)
75 Clamp lever (operating lever)
75B Cam portion 90 Lifting mechanism (position changing mechanism)
174 Fixed washer (pressing member)
174A pressing portion (fixing force applying portion)
T Tip Tool

Claims (6)

A housing having a cylindrical portion;
A prime mover accommodated in the housing; and
an output shaft that is rotated by the prime mover and to which a tool tip can be attached;
A base having a cylindrical outer insertion portion that is inserted into the cylindrical portion;
a fixing mechanism including a pair of fixing force applying parts that are provided on the outer insertion part and that apply a fixing force for fixing the outer insertion part to the cylindrical part by being operated;
Equipped with
The extrapolation unit is
A first chuck portion constituting one circumferential end portion of the outer insertion portion;
A second chuck portion that constitutes the other circumferential end portion of the outer insertion portion;
A slit between the first chuck portion and the second chuck portion in the circumferential direction of the extrapolation portion;
It is composed of
The fixing mechanism includes:
a pair of fixed shafts, one end of which engages with the first chuck portion and the other end of which protrudes from the second chuck portion toward the other axial side;
A pair of cam portions connected to the other end of the fixed shaft;
a pair of fastening force application portions provided on the other end of the fixed shaft and pressed by the cam portion to apply the fastening force to the second chuck portion;
having
The pair of fixing force application portions are arranged at a distance from each other in the axial direction of the extrapolation portion, and input the fixing force to the second chuck portion by pressing the second chuck portion toward the first chuck portion, thereby bringing the second chuck portion closer to the first chuck portion . The fixing mechanism has an operating lever configured to be operable,
2. The work machine according to claim 1, wherein the operating lever connects the pair of cam portions. a connecting groove that is open toward the other axial side of the fixed shaft is formed at the other end of the fixed shaft, and the cam portion is connected to the fixed shaft inside the connecting groove,
The fixing force applying portion is
a contact portion disposed inside the connecting groove and configured to be able to contact the cam portion;
a pressing portion that is fitted onto the fixed shaft, connected to the abutment portion, and presses the second chuck portion toward the first chuck portion;
3. The work machine according to claim 1 or 2, further comprising: The extrapolation unit is provided with a position change mechanism between the pair of fixed shafts,
The work machine according to any one of claims 1 to 3, wherein the position change mechanism is actuated to change the axial position of the base relative to the cylindrical portion. The work machine according to claim 1, wherein the fixing force imparting portion generates a fixing force on the outer insertion portion through a rigid member provided on one axial side portion and the other axial side portion of the outer insertion portion in the first chuck portion and the second chuck portion. The work machine described in claim 5, wherein the rigid member includes a first rigid member arranged on one axial side portion of the outer insertion portion of the first chuck portion and the second chuck portion, and a second rigid member arranged on the other axial side portion of the outer insertion portion of the first chuck portion and the second chuck portion, spaced apart from the first rigid member.

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