Patent Description:
In an electrically-powered trimmer (work machine) described in Patent Document <NUM> below, a cylinder part of a base is externally inserted onto a motor case (housing). A slit is formed in the cylinder part of the base, and a shaft is bridged over between flanges at both circumferential ends of the base. A lever is connected to the shaft. By operating the lever, the cylinder part of the base is deformed so as to tighten the motor case, and the cylinder part is fixed to the motor case.

Patent Document <NUM>: <CIT>. Further prior art can be found in <CIT> which discloses the preamble of claim <NUM> and <CIT> which discloses the preamble of claim <NUM>.

However, in the electrically-powered trimmer, since the cylinder part of the base is deformed so as to tighten the motor case and the cylinder part is fixed to the motor case as described above, there is a possibility that the motor case may be deformed or damaged by a tightening force of the cylinder part with respect to the motor case. As a result, for example, a fixing force of the base may be reduced, and operability may deteriorate. In the electrically-powered trimmer, since the lever provided in the cylinder part of the base is provided in one place, a force from the lever that acts on the cylinder part of the base tends to concentrate on one portion of the cylinder part. As a result, for example, if the base is made of resin, there is a possibility that the portion of the cylinder part of the base may be greatly bent and deformed, and the operability may deteriorate. There is also a problem that, when the lever is operated to release the tightening force of the cylinder part of the base with respect to the motor case, the fixing force of the cylinder part with respect to the motor case may immediately disappear, and the base may fall to the motor case. Accordingly, it is necessary for an operator to carry out an operation of releasing the lever while supporting the base, leading to reduction in the operability. Hence, the electrically-powered trimmer has room for improvement in terms of improving the operability for realizing a suitable fixing structure with respect to the base.

In consideration of the above facts, an object of the present invention is to improve operability of a suitable fixing structure with respect to the base.

According to one or more embodiments of the present invention, a work machine includes: a motor; an output shaft rotated by the motor, to which a tip tool is attachable; a housing, configured to include an inner case including an accommodation part that accommodates the motor and an outer case located outside the accommodation part; and a base, attachable to and detachable from a mounting surface formed on a side surface of the outer case and having a contact surface able to contact a workpiece. The inner case is provided with a fixing part fixing the outer case. The fixing part is arranged inside the mounting surface in a radial direction of the motor as viewed in an axial direction of the motor.

According to one or more embodiments of the present invention, a work machine includes: a motor; an output shaft rotated by the motor, to which a tip tool is attachable; a housing, configured to include an inner case including an accommodation part that accommodates the motor and an outer case located outside the accommodation part; and a base, attachable to and detachable from a mounting surface formed on a side surface of the outer case and having a contact surface able to contact a workpiece. A fixing part fixing the outer case is provided in a portion on one side of the accommodation part in an axial direction of the motor, and an overhang is connected to the other side of the accommodation part. The overhang projects from the mounting surface as viewed in the axial direction of the motor.

According to one or more embodiments of the present invention, in the work machine, an overhang is connected to the other side of the accommodation part in the axial direction of the motor, and the overhang projects radially outward of the mounting surface as viewed in the axial direction of the motor.

According to one or more embodiments of the present invention, in the work machine, the fixing part is arranged inside the mounting surface in the radial direction of the motor as viewed in the axial direction of the motor.

According to one or more embodiments of the present invention, in the work machine, the accommodation part is an inner cylinder part having a cylindrical shape. The outer case is a disassemblable single member and is formed in a cylindrical shape. The inner case is inserted inside the outer case. The fixing part is provided at one end of the inner case in the axial direction of the motor.

According to one or more embodiments of the present invention, in the work machine, a controller controlling the motor is accommodated in the overhang, and the controller projects radially outward of an outer peripheral surface of the outer case as viewed in the axial direction of the outer case.

According to one or more embodiments of the present invention, in the work machine, the overhang is provided with a battery attachment and detachment part to which a battery supplying electric power to the motor is attached, and the battery attachment and detachment part projects outward of the mounting surface as viewed in the axial direction.

According to one or more embodiments of the present invention, in the work machine, a bearing supporting the output shaft is provided inside the inner cylinder part, and the inner case is provided with a bearing holder holding the bearing. The fixing part is formed on the bearing holder.

According to one or more embodiments of the present invention, in the work machine, the inner cylinder part is configured to include a small diameter portion and a large diameter portion having a larger diameter than the small diameter portion. An outer peripheral surface of the large diameter portion is in contact with the outer case.

According to one or more embodiments of the present invention, in the work machine, the large diameter portion is provided on each of both axial sides of the motor with respect to the small diameter portion.

According to one or more embodiments of the present invention, in the work machine, a fan rotated by driving the motor is provided inside the inner case. An airflow generated by the fan flows through between the small diameter portion and the outer case.

According to one or more embodiments of the present invention, in the work machine, a communication part is formed in the large diameter portion, and the communication part communicates inside of the inner case with a space between the small diameter portion and the outer case.

According to one or more embodiments of the present invention, in the work machine, a recess open toward the other side in the axial direction is formed at the other end of the outer case in the axial direction. The inner case is provided with an operating part performing an on or off operation of the motor, and the operating part is arranged in the recess.

According to one or more embodiments of the present invention, in the work machine, a protrusion protruding outward in the radial direction is formed in the inner cylinder part, and a groove fitted with the protrusion and restricting rotation of the outer case with respect to the inner case is formed in the outer case.

According to one or more embodiments of the present invention, in the work machine, the operating part is configured to be able to be pressed radially inward of the inner cylinder part, and the operating part is operated to thereby press a switch provided inside the inner cylinder part.

According to one or more embodiments of the present invention, a work machine includes: a housing, including a cylinder part; a prime mover, accommodated in the housing; an output shaft rotated by the prime mover, to which a tip tool is attachable; a base, including an external insertion part externally inserted onto the cylinder part; and a fixing mechanism, provided in the external insertion part and including a plurality of fixing force imparting parts operated to thereby impart a fixing force that fixes the external insertion part to the cylinder part. The plurality of fixing force imparting parts are arranged apart in the axial direction of the external insertion part.

According to one or more embodiments of the present invention, a work machine includes: a housing, including a cylinder part; a prime mover, accommodated in the housing; an output shaft rotated by the prime mover, to which a tip tool is attachable; a base, including an external insertion part externally inserted onto the cylinder part; and a fixing mechanism, mounted on a clamp part protruding radially outward from the external insertion part and including a fixing force imparting part operated to thereby impart a fixing force that fixes the external insertion part to the cylinder part. The fixing force imparting part generates the fixing force in the external insertion part via a rigid member provided in an upper portion and a lower portion of the clamp part.

According to one or more embodiments of the present invention, a work machine includes: a housing, including a cylinder part; a motor, accommodated in the housing; an output shaft rotated by the motor, to which a tip tool is attachable; a base, externally inserted onto the cylinder part and having a contact surface able to contact a workpiece; a fixing mechanism, provided in the base and operated to thereby switch between a fixed state in which the base is fixed to the housing and a released state in which the fixed state of the base to the housing is released; and a holding mechanism, provided in the base and holding the base in a temporarily fixed state to the housing in the released state of the fixing mechanism.

According to one or more embodiments of the present invention, in the work machine, the holding mechanism holds the base in the temporarily fixed state by frictional force generated between the cylinder part and the base.

According to one or more embodiments of the present invention, in the work machine, the base is configured to include: an external insertion part, externally inserted onto the cylinder part and having a portion formed in a cylindrical shape open radially outward; a first clamp part, constituting one circumferential end of the external insertion part; and a second clamp part, constituting the other circumferential end of the external insertion part. The fixing mechanism connects the first clamp part with the second clamp part. When the fixing mechanism switches from the released state to the fixed state, the first clamp part and the second clamp part are brought closer to each other and the external insertion part is tightened to the cylinder part.

According to one or more embodiments of the present invention, a work machine having improved operability can be realized.

An electrically-powered trimmer <NUM> as a work machine according to the present embodiment will be described below with reference to the drawings. As shown in <FIG>, the electrically-powered trimmer <NUM> is formed in a substantially columnar shape as a whole. In the following description, one side (side in the direction of arrow A in <FIG>) of the electrically-powered trimmer <NUM> in an axial direction is taken as a lower side of the electrically-powered trimmer <NUM>, and the other side (side in the direction of arrow B in <FIG>) of the electrically-powered trimmer <NUM> in the axial direction is taken as an upper side of the electrically-powered trimmer <NUM>. In plan view from above, a direction orthogonal to an up-down direction is taken as a first direction (see arrow C and arrow D in <FIG> and <FIG>), and a direction orthogonal to the first direction is taken as a second direction (see arrow E and arrow F in <FIG> and <FIG>).

The electrically-powered trimmer <NUM> is configured as a tool that performs cutting of a workpiece arranged below the electrically-powered trimmer <NUM>. The electrically-powered trimmer <NUM> is configured to include a trimmer body <NUM>, a base <NUM>, a battery <NUM> as a battery, a fixing mechanism <NUM>, a holding mechanism <NUM>, a lifting mechanism <NUM> as a position changing mechanism, and a controller <NUM>. Each configuration of the electrically-powered trimmer <NUM> will be described below.

As shown in <FIG>, the trimmer body <NUM> is configured to include a housing <NUM>, a motor <NUM> as a prime mover, a trigger <NUM> as an operating part, a speed setting dial <NUM>, and a lock button <NUM> as a state switcher.

The housing <NUM> constitutes an outer shell of the trimmer body <NUM>. The housing <NUM> has a double structure. Specifically, the housing <NUM> is configured to include an inner case <NUM> constituting an inner peripheral portion of the housing <NUM> and an outer case <NUM> constituting an outer peripheral portion of the housing <NUM>.

As shown in <FIG>, the inner case <NUM> is made of resin. The inner case <NUM> is formed in a substantially bottomed cylindrical shape open downward. Specifically, the inner case <NUM> is configured to include an upper case part <NUM> as an overhang constituting an upper end of the inner case <NUM> and an inner cylinder part <NUM> having a cylindrical shape extending downward from the upper case part <NUM>. The upper case part <NUM> is formed in a substantially rectangular shape as viewed from below, and projects from the inner cylinder part <NUM> toward one side in the first direction (side in the direction of arrow C in <FIG> and <FIG>).

The inner case <NUM> is divided into two in the second direction. In detail, the inner case <NUM> is configured to include a first inner case 24A constituting a portion on one side in the second direction (side in the direction of arrow E in <FIG>) of the inner case <NUM>, and a second inner case 24B constituting a portion on the other side in the second direction (side in the direction of arrow F in <FIG>) of the inner case <NUM>. The first inner case 24A and the second inner case 24B are fastened and fixed with their respective openings butt against each other.

The inner cylinder part <NUM> is configured to include a pair of large diameter portions 26A constituting an upper end and a lower end of the inner cylinder part <NUM>, and a small diameter portion 26B constituting a vertically intermediate portion of the inner cylinder part <NUM>. A diameter of the small diameter portion 26B is set smaller than a diameter of the large diameter portion 26A. At an upper end of the large diameter portion 26A on the upper side, an inner cylinder expanded portion 26C is formed one-step raised radially outward. In portions on one side and the other side in the first direction of the inner cylinder expanded portion 26C, a pair of expanded protrusions 26D protruding downward are formed. Accordingly, a lower end of the inner cylinder expanded portion 26C is formed uneven as viewed from radially outside the inner cylinder part <NUM>.

A trigger mounting part 26E for mounting a trigger <NUM> described later is formed on the expanded protrusion 26D on one side in the first direction. The trigger mounting part 26E protrudes toward one side in the first direction with respect to the expanded protrusion 26D. A button mounting part 26F for mounting a lock button <NUM> described later is formed on the expanded protrusion 26D on the other side in the first direction. The button mounting part 26F is one-step lowered radially inward with respect to the expanded protrusion 26D.

An upper communication hole <NUM> (see <FIG> and <FIG>) as a communication part is formed penetrating portions on one side and the other side in the second direction of the large diameter portion 26A on the upper side. Specifically, the upper communication hole <NUM> is arranged between the pair of expanded protrusions 26D. The upper communication hole <NUM> is formed in a rectangular shape as viewed from radially outside the inner cylinder part <NUM>, and an opening of the upper communication hole <NUM> is open downward. At a boundary portion between the large diameter portion 26A on the lower side and the small diameter portion 26B, three lower communication holes <NUM> (see <FIG>, <FIG>, and <FIG>) are respectively formed penetrating portions on one side and the other side in the second direction. That is, six lower communication holes <NUM> are formed in the inner cylinder part <NUM>. The lower communication holes <NUM> are formed in an elongated hole shape extending in the circumferential direction of the inner cylinder part <NUM>, and are arranged side by side in the circumferential direction of the inner cylinder part <NUM>. The lower communication hole <NUM> is a communication part in the present invention.

A plurality of (four in the present embodiment) contact parts 26J (see <FIG> and <FIG>) are respectively formed on an outer periphery of the pair of large diameter portions 26A. That is, eight contact parts 26J are formed in the inner cylinder part <NUM> in the present embodiment. The contact part 26J is formed in a substantially rectangular shape with the up-down direction as the longitudinal direction as viewed from radially outside the inner cylinder part <NUM>, and slightly protrudes radially outward with respect to the large diameter portion 26A. The contact parts 26J are arranged at equal intervals in the circumferential direction of the inner cylinder part <NUM>. At an upper end of the small diameter portion 26B, a protrusion <NUM> (see <FIG> and <FIG>) protruding radially outward is formed at the opening of the upper communication hole <NUM> on one side in the second direction.

A bearing holder <NUM> for holding a second bearing <NUM> described later is formed at the lower end of the inner cylinder part <NUM>. The bearing holder <NUM> is formed in a substantially annular plate shape with the up-down direction as a plate thickness direction, and extends radially inward from the lower end of the inner cylinder part <NUM>. In portions on one side and the other side in the second direction of the bearing holder <NUM>, a plurality of (five in the present embodiment) inner exhaust ports <NUM> are respectively formed. Specifically, three inner exhaust ports <NUM> are formed in the portion on one side in the second direction of the bearing holder <NUM>, and two inner exhaust ports <NUM> are formed in the portion on the other side in the second direction of the bearing holder <NUM>. The inner exhaust ports <NUM> are formed in an elongated hole shape extending in the circumferential direction of the inner cylinder part <NUM>, and are arranged side by side in the circumferential direction of the inner cylinder part <NUM>. On the bearing holder <NUM>, a plurality of (four in the present embodiment) fixing bosses 26N for fixing the outer case <NUM> described later are formed. The fixing bosses 26N are formed in a cylindrical shape with the up-down direction as the axial direction, and are arranged at equal intervals in the circumferential direction of the inner cylinder part <NUM> and between the inner exhaust ports <NUM>. Accordingly, the fixing boss 26N for fixing the outer case <NUM> described later is arranged radially inside an outer peripheral surface of the inner cylinder part <NUM>. The fixing boss 26N is a fixing part in the present invention.

In the upper case part <NUM>, a battery mounting part 28A as a battery attachment and detachment part for mounting the battery <NUM> described later is formed. The battery mounting part 28A is formed in a concave shape open upward and toward the other side in the first direction. The upper case part <NUM> is provided with a connector <NUM> (see <FIG> and <FIG>). The connector <NUM> is exposed inside the battery mounting part 28A.

An intake port 28B (see <FIG> and <FIG>) is formed penetrating a lower end portion of a sidewall on both sides in the second direction of the upper case part <NUM>. The intake port 28B is formed in an elongated hole shape with the first direction as the longitudinal direction. That is, the intake port 28B is arranged above the upper communication hole <NUM> of the inner case <NUM>.

As shown in <FIG>, the outer case <NUM> is made of metal and is composed of a disassemblable single member. The outer case <NUM> is formed in a substantially bottomed cylindrical shape open downward with the up-down direction as the axial direction. Specifically, the outer case <NUM> is configured to include an outer cylinder part 30A having a cylindrical shape and a case bottom 30B constituting a lower end of the outer case <NUM>. The outer cylinder part 30A is externally inserted onto the inner cylinder part <NUM> of the inner case <NUM>. The inner cylinder part <NUM> and the outer cylinder part 30A constitute a cylinder part 22A of the housing <NUM>. The term "externally inserted" herein indicates a manner in which an outer peripheral portion of a target is inserted inside, and indicates a state in which the outer cylinder part 30A has the inner cylinder part <NUM> inserted inside thereof.

An insertion part 30C is formed penetrating a central portion of the case bottom 30B. Five outer exhaust ports 30D are formed penetrating the case bottom 30B at positions corresponding to the inner exhaust port <NUM> of the inner case <NUM>. The outer exhaust port 30D corresponds to the inner exhaust port <NUM> and is formed in an elongated hole shape with the circumferential direction of the outer cylinder part 30A as the longitudinal direction. Accordingly, the inside and the outside of the inner case <NUM> are communicated by the inner exhaust port <NUM> and the outer exhaust port 30D. Furthermore, four fixing holes 30E (see <FIG>) are formed penetrating the case bottom 30B at positions corresponding to the fixing boss 26N of the inner case <NUM>. By inserting a fixing bolt BL (in a broad sense, an element grasped as a fixing member) into the fixing hole 30E from below and screwing it to the fixing boss 26N, the outer case <NUM> is fixed to the inner case <NUM>.

At an upper end of the outer case <NUM>, a case gouged portion 30F as a pair of recesses is formed in a position corresponding to the expanded protrusion 26D of the inner case <NUM>. The case gouged portion 30F is formed in a concave shape open upward, and is formed in a trapezoidal shape as viewed from radially outside the outer case <NUM>. In a state of fixing the outer case <NUM> to the inner case <NUM>, the upper end of the outer case <NUM> is arranged below the inner cylinder expanded portion 26C of the inner case <NUM>, and the outer cylinder part 30A covers the portion of the inner cylinder part <NUM> of the inner case <NUM> excluding the inner cylinder expanded portion 26C from radially outside. That is, the upper communication hole <NUM> is covered by the upper end of the outer case <NUM> so as to be invisible.

In the state of fixing the outer case <NUM> to the inner case <NUM>, an inner peripheral surface of the outer cylinder part 30A is in contact with the contact part 26J of the inner case <NUM>. Accordingly, a gap 22B (see <FIG> and <FIG>) is formed between the small diameter portion 26B and the outer case <NUM> in the cylinder part 22A. The gap 22B is formed over the entire circumference of the cylinder part 22A in the circumferential direction. An upper end of the gap 22B communicates with the inside of the inner case <NUM> through the upper communication hole <NUM>. A lower end of the gap 22B communicates with the inside of the inner case <NUM> through the lower communication hole <NUM>. A diameter of the outer cylinder part 30A is set so that an outer peripheral surface of the outer cylinder part 30A is flush with an outer peripheral surface of the inner cylinder expanded portion 26C of the inner case <NUM>.

On the inner peripheral surface at the upper end of the outer cylinder part 30A, an engagement groove <NUM> (see <FIG>) as a groove is formed in a position corresponding to the protrusion <NUM> of the inner case <NUM>. The engagement groove <NUM> extends in the up-down direction and is open upward. The following configuration is achieved: when the outer case <NUM> is externally inserted onto the inner case <NUM>, the protrusion <NUM> is inserted into the engagement groove <NUM>, and the protrusion <NUM> and the engagement groove <NUM> are engaged in the circumferential direction of the inner case <NUM>.

As shown in <FIG>, <FIG> and <FIG>, a first rack <NUM> and a second rack <NUM> as a pair of racks constituting the lifting mechanism <NUM> described later are formed on an outer periphery of the outer cylinder part 30A. The first rack <NUM> is formed in a portion on one side in the second direction of the outer cylinder part 30A. The second rack <NUM> is formed in a portion on the other side in the second direction of the outer cylinder part 30A. The first rack <NUM> and the second rack <NUM> extend in the up-down direction. That is, the first rack <NUM> and the second rack <NUM> are arranged <NUM> degrees apart in the circumferential direction of the outer cylinder part 30A.

The first rack <NUM> has a plurality of rack grooves 92A. The rack groove 92A extends in the circumferential direction of the outer cylinder part 30A and is open radially outward of the outer cylinder part 30A. The plurality of rack grooves 92A are arranged side by side at equal intervals in the up-down direction. A portion between the rack grooves 92A adjacent to each other in the up-down direction is configured as a rack tooth 92B. Accordingly, in the first rack <NUM>, a plurality of rack teeth 92B are arranged side by side at equal intervals in the up-down direction.

The second rack <NUM> is configured in the same manner as the first rack <NUM>. That is, the second rack <NUM> has a plurality of rack grooves 94A arranged side by side in the up-down direction. In the second rack <NUM>, a portion between the rack grooves 94A adjacent to each other in the up-down direction is configured as a rack tooth 94B. A plurality of rack teeth 94B are arranged side by side at equal intervals in the up-down direction.

As shown in <FIG> and <FIG>, the motor <NUM> is configured as a brushless motor. Inside the inner cylinder part <NUM> of the inner case <NUM>, the motor <NUM> is arranged coaxially with the inner cylinder part <NUM> and below the intake port 28B and the upper communication hole <NUM>, and is fixed to the inner cylinder part <NUM>. An upper end of an output shaft 34A of the motor <NUM> is rotatably supported by a first bearing 36U provided in the inner cylinder part <NUM>. On the other hand, a lower end portion of the output shaft 34A is rotatably supported by a second bearing <NUM> as a bearing. The second bearing <NUM> is held by the bearing holder <NUM> of the inner cylinder part <NUM>. The lower end (tip) of the output shaft 34A protrudes downward from a lower end of the housing <NUM>. A collet chuck <NUM> is provided at the lower end of the output shaft 34A. By the collet chuck <NUM>, a tip tool T is detachably fixed to the lower end of the output shaft 34A. Furthermore, the following configuration is achieved: the motor <NUM> is electrically connected to a control part <NUM> described later, and the motor <NUM> is driven by the control part <NUM>. Accordingly, the workpiece may be subjected to cutting by the tip tool T that rotates with the output shaft 34A. The collet chuck <NUM> corresponds to a tool holder of the present invention.

A fan <NUM> is provided on the output shaft 34A of the motor <NUM> above the second bearing <NUM> so as to be integrally rotatable therewith. The fan <NUM> is configured as a so-called axial fan and is configured to generate a downward airflow in the inner case <NUM>. Accordingly, the following configuration is achieved: as cooling air AR flows into the inner case <NUM> from the intake port 28B, the cooling air AR is discharged to the outside of the housing <NUM> from the inner exhaust port <NUM> of the inner case <NUM> and the outer exhaust port 30D of the outer case <NUM>.

As shown in <FIG>, the trigger <NUM> is configured as an operating part for driving or stopping the motor <NUM>. The trigger <NUM> is mounted on the trigger mounting part 26E of the inner case <NUM> and is exposed to one side in the first direction so as to be able to be operated. An upper end of the trigger <NUM> is rotatably supported by the inner case <NUM> with the second direction as the axial direction. Accordingly, the trigger <NUM> is configured to be rotatable between an initial position (position indicated by a solid line in <FIG>) and an operation position (position indicated by a chain double-dashed line in <FIG>) achieved by counterclockwise rotation from the initial position as viewed from one side in the second direction. The trigger <NUM> is energized toward the initial position by an energizing spring (not shown). The trigger <NUM> is held in the initial position in a non-operation state of the trigger <NUM>.

A microswitch <NUM> as a switch is provided on the other side of the trigger <NUM> in the first direction. The microswitch <NUM> is electrically connected to the control part <NUM> described later. The following configuration is achieved: as the trigger <NUM> is operated from the initial position to the operation position, a lower end of the trigger <NUM> presses the microswitch <NUM>, and the microswitch <NUM> outputs a detection signal to the control part <NUM>.

The speed setting dial <NUM> is configured as a dial for changing a rotational speed of the motor <NUM>. The speed setting dial <NUM> is formed in a substantially disk shape with the up-down direction as the plate thickness direction, and is rotatably supported by the inner case <NUM> with the up-down direction as the axial direction in a portion on the other side in the first direction of the upper case part <NUM> of the inner case <NUM>. The speed setting dial <NUM> is exposed from the upper case part <NUM> to the other side in the first direction so as to be able to be operated.

An encoder <NUM> for detecting a rotation position of the speed setting dial <NUM> is provided above the speed setting dial <NUM>. The encoder <NUM> is electrically connected to the control part <NUM>. The following configuration is achieved: as the speed setting dial <NUM> rotates, a detection signal corresponding to the rotation position of the speed setting dial <NUM> is output from the encoder <NUM> to the control part <NUM>.

The lock button <NUM> is provided on the button mounting part 26F of the inner case <NUM> and is exposed from the button mounting part 26F to the other side in the first direction. The lock button <NUM> is formed in a substantially rectangular shape as viewed from the other side in the first direction, and is composed of an elastic member. A button board <NUM> is provided adjacent to the lock button <NUM> on one side in the first direction. A tact switch <NUM> is mounted on the button board <NUM>. The tact switch <NUM> is electrically connected to the control part <NUM> described later. The following configuration is achieved: as the lock button <NUM> is pressed, the tact switch <NUM> outputs a detection signal to the control part <NUM>. While details will be described later, the lock button <NUM> is configured as a button that prohibits or permits driving of the motor <NUM> when the battery <NUM> is connected to the connector <NUM> of the housing <NUM>. The lock button <NUM> is also configured as a button that continues or stops driving of the motor <NUM> while the motor <NUM> is being driven.

As shown in <FIG>, the base <NUM> is made of metal and is formed in a substantially bottomed cylindrical shape open upward. Specifically, the base <NUM> is configured to include a base cylinder <NUM> as an external insertion part and a plate <NUM> constituting a lower end of the base <NUM>.

The base cylinder part <NUM> is formed in a substantially cylindrical shape with the up-down direction as the axial direction, and a portion of the base cylinder part <NUM> in the circumferential direction is open. That is, a slit 62A extending in the up-down direction is formed in the base cylinder part <NUM>, and the slit 62A penetrates in the up-down direction and a radial direction of the base cylinder part <NUM>. A width dimension of the slit 62A is set greater than a width dimension of the first rack <NUM> and the second rack <NUM>. The base cylinder part <NUM> (base <NUM>) is externally inserted from below onto the cylinder part 22A of the housing <NUM>, and is fixed to the cylinder part 22A by the fixing mechanism <NUM> described later. Specifically, in a fixed state of the base <NUM> to the housing <NUM>, the first rack <NUM> or the second rack <NUM> is arranged inside the slit 62A as viewed from radially outside the base cylinder part <NUM>. The cylinder part 22A of the housing <NUM> and the base cylinder part <NUM> are configured as a grip gripped by the operator.

An opening 62B is formed in a portion on one side in the second direction at a lower end of the base cylinder part <NUM>. The opening 62B is formed in a concave shape open downward as viewed from one side in the second direction. A lower end of the slit 62A communicates with the opening 62B. Accordingly, the following configuration is achieved: while the base <NUM> is connected to the housing <NUM>, the tip tool T fixed to the output shaft 34A is visible from the opening 62B.

A first clamp part (first chuck part) 62C is provided at one circumferential end of the base cylinder part <NUM>, and a second clamp part 62D is provided at the other circumferential end of the base cylinder part <NUM>. The first clamp part 62C and the second clamp part (second chuck part) 62D are formed in a substantially long block shape with the up-down direction as the longitudinal direction, and extend downward while protruding toward one side in the second direction. The first clamp part (first chuck part) 62C and the second clamp part (second chuck part) 62D correspond to a clamp part or chuck part in the present invention. The clamp part (chuck part) is a portion of the base <NUM> protruding radially outward from the base cylinder part <NUM> and extending in the axial direction.

The plate <NUM> is formed in a substantially rectangular plate shape with the up-down direction as the plate thickness direction, and is connected to the lower end of the base cylinder part <NUM>. A base insertion part 64A (see <FIG> and <FIG>) for insertion of the output shaft 34A and the tip tool T is formed penetrating a substantially central portion of the plate <NUM>. A lower surface of the plate <NUM> is configured as a contact surface that contacts the workpiece during machining of the workpiece.

A bevel base <NUM> is provided below the plate <NUM>. The bevel base <NUM> is formed in a substantially rectangular plate shape with the up-down direction as the plate thickness direction. The bevel base <NUM> is fixed to the plate <NUM> with a fixing member such as a screw. Like the plate <NUM>, the bevel base <NUM> has a bevel insertion part 66A (see <FIG> and <FIG>) formed penetrating therethrough for insertion of the tip tool T.

As shown in <FIG> and <FIG>, the battery <NUM> is formed in a substantially rectangular parallelepiped shape. The battery <NUM> is attached to the battery mounting part 28A of the housing <NUM> from the other side in the first direction. The battery <NUM> includes a connector (not shown), and the following configuration is achieved: in a state in which the battery <NUM> is attached to the battery mounting part 28A, the connector is connected to the connector <NUM>, and electric power is supplied from the battery <NUM> to the control part <NUM>. The battery <NUM> includes a pair of lock members 58A. The lock member 58A is provided on one side portion and the other side portion of the battery <NUM> in the second direction. In the state in which the battery <NUM> is attached to the battery mounting part 28A, the lock member 58A is engaged with the upper case part <NUM> of the housing <NUM>, and movement of the battery <NUM> toward the other side in the first direction is restricted.

As shown in <FIG> and <FIG>, the fixing mechanism <NUM> is provided in the base <NUM> and configured as a mechanism operated to thereby switch between the fixed state of the base <NUM> to the housing <NUM> and a released state in which fixation of the base <NUM> to the housing <NUM> is released. The fixing mechanism <NUM> is configured to include an upper-lower pair of fixing shafts <NUM> and a clamp lever <NUM>. The fixing shaft <NUM> is formed in a substantially columnar shape with the first direction as the axial direction, and is bridged over between upper ends and lower ends of the first clamp part 62C and the second clamp part 62D of the base <NUM> so as to be relatively movable in the first direction. One end of the fixing shaft <NUM> protrudes from the first clamp part 62C toward one side in the first direction. A male thread is formed at one end of the fixing shaft <NUM>. A fixing nut <NUM> is screwed to one end of the fixing shaft <NUM> and arranged on one side of the first clamp part 62C in the first direction. A first fixing washer <NUM> (engagement washer <NUM>) is attached to one end of the fixing shaft <NUM>. The first fixing washer <NUM> is arranged between the fixing nut <NUM> and the first clamp part 62C. Accordingly, one end of the fixing shaft <NUM> is engaged with the first clamp part 62C, and movement of the fixing shaft <NUM> toward the other side in the axial direction is restricted.

The other end of the fixing shaft <NUM> protrudes from the second clamp part 62D toward the other side in the first direction. A connecting groove 71A (see <FIG>) is formed at the other end of the fixing shaft <NUM>. The connecting groove 71A is open toward the other side in the first direction and penetrates in the second direction. A groove depth of the connecting groove 71A is set so that a bottom of the connecting groove 71A is arranged inside the second clamp part 62D.

A second fixing washer <NUM> (fixing washer <NUM>) as a fixing force imparting part is attached to the other end of the fixing shaft <NUM>. The second fixing washer <NUM> is arranged adjacent to the second clamp part 62D on the other side in the first direction. That is, a pair of second fixing washers <NUM> are arranged apart in the up-down direction, and are arranged adjacent to both longitudinal ends of the second clamp part 62D on the other side in the first direction. The second fixing washer <NUM> is configured to include a washer contact part 74A (see <FIG>) as a contact part extending in the second direction, and a washer pressing part 74B (see <FIG>) as a pressing part formed in an annular shape and to which both ends of the washer contact part 74A are connected. The washer contact part 74A is arranged inside the connecting groove 71A, and the washer pressing part 74B is externally inserted onto the other end of the fixing shaft <NUM>. The first fixing washer <NUM> (engagement washer <NUM>) and the second fixing washer <NUM> correspond to a rigid member of the present invention.

As viewed in the second direction, the clamp lever <NUM> is formed in a substantially Y-shaped plate shape with the second direction as the plate thickness direction and open toward the other side in the first direction. The clamp lever <NUM> is arranged on one side of the first clamp part 62C and the second clamp part 62D in the second direction. The clamp lever <NUM> is inclined toward the other side in the second direction toward the other side in the first direction as viewed from above, and is curved in a substantially arc shape (see <FIG>). A bend 75A bent toward the other side in the second direction is formed at an upper end and a lower end of the clamp lever <NUM>. A cam part 75B (see <FIG>) protruding toward the other side in the second direction is formed at an end of the bend 75A toward the other side in the first direction. The cam part 75B is inserted into the connecting groove 71A of the fixing shaft <NUM>, and is rotatably supported by a fixing pin <NUM> provided on the fixing shaft <NUM> and with the up-down direction as the axial direction.

Accordingly, the clamp lever <NUM> is configured to be rotatable between a fixing position (position shown in <FIG>) and a release position (position shown in <FIG>) achieved by rotation from the fixing shaft <NUM> toward one side in a rotation direction (side in the direction of arrow G in <FIG>). An outer periphery of the cam part 75B is configured as a cam surface 75C. The cam surface 75C is formed in a substantially arc shape centering on the fixing pin <NUM> as viewed from above. More specifically, a radius of the cam surface 75C from the fixing pin <NUM> may increase toward one side in the rotation direction of the clamp lever <NUM>.

The following configuration is achieved: in the fixing position of the clamp lever <NUM>, the cam surface 75C contacts the washer contact part 74A of the second fixing washer <NUM>, and presses the washer contact part 74A toward one side in the first direction. On the other hand, the following configuration is achieved: in the release position of the clamp lever <NUM>, the cam surface 75C is arranged apart from the washer contact part 74A on the other side in the first direction, and pressing of the cam surface 75C against the washer contact part 74A is released. Accordingly, the following configuration is achieved: as the clamp lever <NUM> is rotated from the release position to the fixing position, by a pressing force of the cam part 75B on the second clamp part 62D via the second fixing washer <NUM>, the base cylinder part <NUM> is deformed so that the second clamp part 62D is displaced toward the first clamp part 62C. As a result, in the fixing position of the clamp lever <NUM>, a clamping force is generated with which the base cylinder part <NUM> tightens the cylinder part 22A of the housing <NUM>. By the clamping force, the base <NUM> is fixed to the housing <NUM> (outer cylinder part 30A) (this state is hereinafter referred to as fixed state). In the release position of the clamp lever <NUM>, the clamping force of the base cylinder part <NUM> is released, and the fixed state of the base <NUM> to the housing <NUM> is released (this state is hereinafter referred to as released state). Accordingly, the following configuration is achieved: by rendering the fixing mechanism <NUM> in the released state, a position of the base <NUM> with respect to the housing <NUM> in the up-down direction can be variable. A portion of the outer cylinder part 30A that receives the clamping force is a region where the base <NUM> can be mounted, and the portion functions as a mounting surface of the base <NUM>.

A lever cap <NUM> is provided at a tip (one end in the first direction) of the clamp lever <NUM>. The tip of clamp lever <NUM> is covered with the lever cap <NUM>. The tip of the clamp lever <NUM> is configured as a lever operating part of the clamp lever <NUM>. The operator may grip the lever cap <NUM> and rotate the clamp lever <NUM>.

The holding mechanism <NUM> is configured as a mechanism holding the base <NUM> in a temporarily fixed state to the housing <NUM> in the released state of the fixing mechanism <NUM>. Here, the temporarily fixed state in the present embodiment refers to the following state: when the base <NUM> does not fall to the cylinder part 22A of the housing <NUM> due to its own weight, and the lifting mechanism <NUM> described later is manually operated, the base <NUM> is held by the cylinder part 22A so that the base <NUM> is movable relative to the cylinder part 22A in the up-down direction. As shown in <FIG>, <FIG> and <FIG>, the holding mechanism <NUM> is configured to include a connecting shaft <NUM> and a holding spring <NUM> as an energization member.

The connecting shaft <NUM> is formed in a substantially stepped shaft shape with the first direction as the axial direction. Specifically, at one end of the connecting shaft <NUM>, a stopper 81A one-step raised radially outward and an operation knob 81B one-step raised radially outward from the stopper 81A are formed. The operation knob 81B is arranged on one side in the first direction with respect to the stopper 81A. With the operation knob 81B and the stopper 81A protruding from the first clamp part 62C of the base <NUM> toward one side in the first direction, the connecting shaft <NUM> is bridged over between vertically intermediate portions of the first clamp part 62C and the second clamp part 62D so as to be relatively movable in the first direction and rotatable about its own axis. A first holding washer <NUM> is inserted into the connecting shaft <NUM> from the other end side. The first holding washer <NUM> is arranged between the stopper 81A and the first clamp part 62C. The stopper 81A is engaged with the first clamp part 62C via the first holding washer <NUM>, and movement of the connecting shaft <NUM> toward the other side in the axial direction is restricted.

The other end of the connecting shaft <NUM> protrudes from the second clamp part 62D toward the other side in the first direction. A male thread is formed on an outer periphery of the other end of the connecting shaft <NUM>. An adjustment nut <NUM> as a locking part is screwed to the other end of the connecting shaft <NUM>. A second holding washer <NUM> is attached to the other end of the connecting shaft <NUM>. The second holding washer <NUM> is arranged adjacent to the adjustment nut <NUM> on one side in the first direction.

The holding spring <NUM> is configured as a compression coil spring and attached to the other end portion of the connecting shaft <NUM>. Specifically, one end of the holding spring <NUM> is locked by the second clamp part 62D, and the other end of the holding spring <NUM> is locked by the adjustment nut <NUM> via the second holding washer <NUM>. The holding spring <NUM> energizes the second clamp part 62D toward one side in the first direction, and energizes the other end of the connecting shaft <NUM> toward the other side in the first direction.

Here, as described above, one end of the connecting shaft <NUM> is locked by the first clamp part 62C, and movement of the connecting shaft <NUM> toward the other end side is restricted. Hence, in the released state of the fixing mechanism <NUM>, by energization force of the holding spring <NUM>, the first clamp part 62C and the second clamp part 62D are displaced in directions approaching each other, so that the clamping force that tightens the cylinder part 22A of the housing <NUM> is generated in the base cylinder part <NUM>. By the clamping force, frictional force is generated between the base <NUM> and the housing <NUM>. The energization force of the holding spring <NUM> is set so that the base <NUM> is prevented from falling under its own weight by the frictional force. The following configuration is achieved: when the lifting mechanism <NUM> described later is actuated, an inner peripheral surface of the base cylinder part <NUM> of the base <NUM> slides on the outer peripheral surface of the outer cylinder part 30A of the outer case <NUM>, and the base <NUM> moves relative to the housing <NUM> in the up-down direction. In the second clamp part 62D, a spring receptacle 62E (see <FIG>) having a concave shape is formed open on the other side in the first direction. A portion of the holding spring <NUM> is accommodated in the spring receptacle 62E. By rotating the adjustment nut <NUM>, the adjustment nut <NUM> performs relative movement in the axial direction of the connecting shaft <NUM>. Thus, the energization force of the holding spring <NUM> can be adjusted by the adjustment nut <NUM>.

As shown in <FIG>, <FIG> and so on, the lifting mechanism <NUM> is configured to include the first rack <NUM> and the second rack <NUM> formed in the housing <NUM>, the connecting shaft <NUM> of the holding mechanism <NUM>, and a pinion <NUM>. That is, the connecting shaft <NUM> is configured as a component of both the holding mechanism <NUM> and the lifting mechanism <NUM>.

The pinion <NUM> is formed in a substantially cylindrical shape with the first direction as the axial direction, is fixed to an axially intermediate portion of the connecting shaft <NUM> so as to be integrally rotatable therewith, and is arranged coaxially with the connecting shaft <NUM>. The connecting shaft <NUM> and the pinion <NUM> may be integrally formed and be configured as a single member. A width length of each of the first rack <NUM> and the second rack <NUM> along the circumferential direction of the cylinder part 22A of the housing <NUM> is set slightly greater than a width length (length in the axial direction) of the pinion <NUM>.

A plurality of pinion teeth 96A are formed on an outer periphery of the pinion <NUM>. The plurality of pinion teeth 96A are formed over the entire circumference of the pinion <NUM> in the circumferential direction. The following configuration is achieved: the pinion <NUM> is arranged between the first clamp part 62C and the second clamp part 62D of the base <NUM>, the pinion tooth 96A is arranged in the rack groove 92A of the first rack <NUM> or in the rack groove 94A of the second rack <NUM> of the housing <NUM>, and the pinion tooth 96A meshes with the rack tooth 92B or the rack tooth 94B (the pinion tooth 96A meshes with the rack tooth 92B in the example shown in <FIG>).

Accordingly, the following configuration is achieved: in the released state of the fixing mechanism <NUM>, by rotating the connecting shaft <NUM> about its own axis, the pinion <NUM> rotates relative to the first rack <NUM> (second rack <NUM>), and the base <NUM> moves up and down in the up-down direction with respect to the housing <NUM>. The pinion tooth 96A is arranged in the rack groove 92A (rack groove 94A). Hence, the following configuration is achieved: when the base <NUM> moves up and down with respect to the housing <NUM>, by engaging the pinion tooth 96A with both longitudinal ends of the rack groove 92A (rack groove 94A), rotation of the base <NUM> relative to the housing <NUM> is restricted. The following configuration is achieved: after a lifting position of the base <NUM> is adjusted, by changing the fixing mechanism <NUM> from the released state to the fixed state, the base <NUM> is fixed to the adjusted position.

The controller <NUM> is accommodated inside the upper case part <NUM> of the housing <NUM> and fixed to the upper case part <NUM>. The controller <NUM> includes the control part <NUM> and an inverter <NUM>. The connector <NUM>, the motor <NUM>, the microswitch <NUM>, the encoder <NUM>, and the tact switch <NUM> are electrically connected to the controller <NUM>. The following configuration is achieved: according to an operation on the trigger <NUM> and the lock button <NUM>, the control part <NUM> controls actuation of the motor <NUM>. The following configuration is achieved: according to the rotation position of the speed setting dial <NUM>, the control part <NUM> controls the rotational speed of the motor <NUM>.

An electrical configuration of the electrically-powered trimmer <NUM> is described using a functional (circuit) block diagram of <FIG>. The controller <NUM> includes a control circuit board (not shown), and the control part <NUM> and the inverter <NUM> are mounted on the control circuit board. The control part <NUM> includes an operation part <NUM>. The operation part <NUM> performs various controls such as drive control of the inverter <NUM>. The operation part <NUM> is a microcomputer. The inverter <NUM> is a circuit in which switching elements 110a (six switching elements 110a are provided in the present embodiment) are bridge-connected. A detection resistor <NUM> is provided in a path of a driving current of a brushless motor as the motor <NUM>. A control circuit voltage supply circuit <NUM> converts a voltage of the battery <NUM> into a voltage suitable for an operation of the control part <NUM> and supplies it to the control part <NUM>. A magnetic sensor <NUM> is, for example, a Hall element, and outputs a signal corresponding to a rotation position of the brushless motor as the motor <NUM>.

In the control part <NUM>, a motor current detection circuit <NUM> detects the driving current of the brushless motor as the motor <NUM> from a terminal voltage of the detection resistor <NUM>. A switch operation detection circuit <NUM> detects an operation performed by the operator on the trigger <NUM> as the operating part. A rotor position detection circuit <NUM> detects the rotation position of the brushless motor as the motor <NUM> based on the signal from the magnetic sensor <NUM>. A motor speed detection circuit <NUM> detects the rotational speed of the brushless motor as the motor <NUM> based on a signal from the rotor position detection circuit <NUM>. The operation part <NUM> calculates the rotational speed of the brushless motor as the motor <NUM> based on a detection result of the rotor position detection circuit <NUM>, and outputs the rotational speed to a control signal output circuit <NUM>.

The control part <NUM> has different control states to change between a case where the tact switch <NUM> (lock button <NUM>) as the state switcher is operated when the brushless motor as the motor <NUM> is in a non-driving state and a case where the tact switch <NUM> (lock button <NUM>) as the state switcher is operated when the brushless motor as the motor <NUM> is in a driving state. For example, when the brushless motor as the motor <NUM> is in the driving state, the control part <NUM> has, as the control state, an on lock state in which driving of the brushless motor as the motor <NUM> is maintained even if the operation on the trigger <NUM> as the operating part is canceled and an on lock release state in which driving of the brushless motor as the motor <NUM> is stopped by canceling the operation on the trigger <NUM> as the operating part. The control part <NUM> may, for example, perform control to switch between the on lock state and the on lock release state based on an operation on the tact switch <NUM> (lock button <NUM>) as the state switcher. For example, when in the on lock state, the control part <NUM> may perform control to release the on lock state based on the operation the trigger <NUM> as the operating part.

Next, an operation of the electrically-powered trimmer <NUM> is described using a flowchart shown in <FIG>.

In the operation of the electrically-powered trimmer <NUM>, in step <NUM> (S1), the battery <NUM> is attached to the battery mounting part 28A of the housing <NUM>, and the battery <NUM> is connected to the connector <NUM>. After the battery <NUM> is connected to the connector <NUM>, the process proceeds to step <NUM> (S2).

In step <NUM>, in the control part <NUM>, a state (off lock state) is achieved in which driving of the motor <NUM> is prohibited. After the processing of step <NUM>, the process proceeds to step <NUM> (S3).

In step <NUM>, the control part <NUM> determines whether the lock button <NUM> has been pressed based on an output signal of the tact switch <NUM>. If the lock button <NUM> has not been pressed in step <NUM> (No in step <NUM>), the process returns to step <NUM>. That is, the off lock state of the motor <NUM> is maintained. On the other hand, if the lock button <NUM> has been pressed in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S4).

In step <NUM>, in the control part <NUM>, a state (off lock release state, also referred to as a drive standby state of the motor <NUM>) is achieved in which driving of the motor <NUM> is permitted. Then, after the processing of step <NUM>, the process proceeds to step <NUM> (S5).

In step <NUM>, the control part <NUM> determines whether the trigger <NUM> has been operated to the operation position based on an output signal of the microswitch <NUM>. If the trigger <NUM> has been operated to the operation position in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S6).

In step <NUM>, the motor <NUM> is driven by the control part <NUM>. Accordingly, the output shaft 34A of the motor <NUM> rotates about its own axis, and the operator subjects the workpiece to cutting by the tip tool T. At this time, the control part <NUM> rotates the output shaft 34A at a rotational speed corresponding to the rotation position of the speed setting dial <NUM>. After the processing of step <NUM>, the process proceeds to step <NUM> (S7).

In step <NUM>, the control part <NUM> determines whether the operation of operating the trigger <NUM> to the operation position is continued based on the output signal of the microswitch <NUM>. In step <NUM>, if the operation of operating the trigger <NUM> to the operation position is not continued, that is, if the trigger <NUM> has returned to the initial position (No in step <NUM>), the process proceeds to step <NUM> (S8).

In step <NUM>, the control part <NUM> stops driving of the motor <NUM>. That is, if the operator cancels the operation on the trigger <NUM>, the driving of the motor <NUM> is stopped. Then, after the processing of step <NUM>, the process returns to step <NUM>.

On the other hand, in step <NUM>, if the operation of operating the trigger <NUM> to the operation position is continued (Yes in step <NUM>), the process proceeds to step <NUM> (S9).

In step <NUM>, the control part <NUM> determines whether the lock button <NUM> has been pressed based on the output signal from the tact switch <NUM>. If the lock button <NUM> has not been pressed in step <NUM> (No in step <NUM>), the process returns to step <NUM>. On the other hand, if the lock button <NUM> has been pressed in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S10).

In step <NUM>, the control part <NUM> achieves a state (on lock state) in which driving of the motor <NUM> is maintained. That is, when the lock button <NUM> is pressed while the trigger <NUM> is operated in the operation position, the process transitions to the on lock state in which driving of the motor <NUM> is maintained. After the processing of step <NUM>, the process proceeds to step <NUM> (S11).

In step <NUM>, the control part <NUM> determines whether the trigger <NUM> has returned to the initial position based on the output signal of the microswitch <NUM>. If the trigger <NUM> has not returned to the initial position in step <NUM> (No in step <NUM>), the process returns to step <NUM>. That is, if the operation performed by the operator of operating the trigger <NUM> to the operation position is continued, the process returns to step <NUM> and the on lock state is maintained.

On the other hand, if the trigger <NUM> has returned to the initial position in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S12). That is, even if the operation performed by the operator on the trigger <NUM> is canceled, the on lock state of the motor <NUM> is maintained and the process proceeds to step <NUM>.

In step <NUM>, the control part <NUM> determines whether the lock button <NUM> has been pressed based on the output signal of the tact switch <NUM>. If the lock button <NUM> has been pressed in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S13).

In step <NUM>, driving of the motor <NUM> is stopped by the control part <NUM>. That is, when the lock button <NUM> is pressed in the on lock state of the motor <NUM>, the on lock state of the motor <NUM> is released and the motor <NUM> stops. Then, after the processing of step <NUM>, the process returns to step <NUM>.

On the other hand, if the lock button <NUM> has not been pressed in step <NUM> (No in step <NUM>), the process proceeds to step <NUM> (S14).

In step <NUM>, the control part <NUM> determines whether the trigger <NUM> has been operated to the operation position based on the output signal of the microswitch <NUM>. If the trigger <NUM> has not been operated to the operation position in step <NUM> (No in step <NUM>), the process returns to step <NUM>. That is, the on lock state of the motor <NUM> is maintained. On the other hand, if the trigger <NUM> has been operated to the operation position in step <NUM> (Yes in step <NUM>), the process proceeds to step <NUM> (S15).

In step <NUM>, driving of the motor <NUM> is stopped by the control part <NUM>. That is, in the on lock state of the motor <NUM>, when the lock button <NUM> is not pressed and the trigger <NUM> is operated to the operation position again, the on lock state of the motor <NUM> is released and the motor <NUM> stops. Then, after the processing of step <NUM>, the process proceeds to step <NUM> (S16).

In step <NUM>, the control part <NUM> determines whether the trigger <NUM> has returned to the initial position based on the output signal of the microswitch <NUM>. If the trigger <NUM> has not returned to the initial position in step <NUM> (No in step <NUM>), the process returns to step <NUM>. That is, the stop state of the motor <NUM> is maintained. On the other hand, if the trigger <NUM> has returned to the initial position in step <NUM> (Yes in step <NUM>), the process returns to step <NUM>. That is, if the operation performed by the operator on the trigger <NUM> is canceled, the process returns to step <NUM> while the motor <NUM> is stopped. Accordingly, as the trigger <NUM> is operated to the operation position again, the motor <NUM> is driven again by the control part <NUM>.

On the other hand, if the trigger <NUM> has not been operated to the operation position in step <NUM> (No in step <NUM>), the process proceeds to step <NUM> (S17).

In step <NUM>, the control part <NUM> determines whether the lock button <NUM> has been pressed based on the output signal from the tact switch <NUM>. If the lock button <NUM> has been pressed in step <NUM> (Yes in step <NUM>), the process returns to step <NUM>. That is, in the control part <NUM>, the motor <NUM> is transitioned from the drive standby state to the off lock state. On the other hand, if the lock button <NUM> has not been pressed in step <NUM> (No in step <NUM>), the process proceeds to step <NUM> (S18).

In step <NUM>, the control part <NUM> determines whether the lock button <NUM> was pressed within a predetermined time (<NUM> seconds in the present embodiment) based on the output signal from the tact switch <NUM>. In step <NUM>, the control part <NUM> determines whether the trigger <NUM> was operated to the operation position within the predetermined time based on the output signal from the microswitch <NUM>. That is, in step <NUM>, the control part <NUM> determines whether the operation on the lock button <NUM> or the trigger <NUM> was performed within the predetermined time.

If the operation on the lock button <NUM> or the trigger <NUM> was performed within the predetermined time in step <NUM> (Yes in step <NUM>), the process returns to step <NUM>. That is, the process returns to the drive standby state of the motor <NUM>. On the other hand, if the operation on the lock button <NUM> or the trigger <NUM> was not performed within the predetermined time in step <NUM> (No in step <NUM>), the process returns to step <NUM>. That is, in the drive standby state of the motor <NUM>, if the operation on the lock button <NUM> or the trigger <NUM> is not performed, the control part <NUM> causes the motor <NUM> to transition from the drive standby state to the off lock state.

Next, effects of the electrically-powered trimmer <NUM> of the present embodiment are described.

The electrically-powered trimmer <NUM> configured as above is configured to include: the housing <NUM>, constituting the outer shell of the trimmer body <NUM>; the inner case <NUM>, including the inner cylinder part <NUM> having a cylindrical shape; and the outer case <NUM>, externally inserted onto the inner case <NUM>. The outer case <NUM> is fixed to the inner case <NUM>. That is, the housing <NUM> has a double structure including the inner case <NUM> and the outer case <NUM>. Hence, rigidity of the housing <NUM> can be increased. Moreover, the outer case <NUM> is composed of a disassemblable single member. The base cylinder part <NUM> of the base <NUM> is detachably and externally inserted onto the outer case <NUM>. That is, a portion of the housing <NUM> directly supporting the base cylinder part <NUM> is composed of a disassemblable single member. Accordingly, support rigidity of the housing <NUM> with respect to the base cylinder part <NUM> can be increased. According to the above, a suitable fixing structure with respect to the base <NUM> can be realized.

In particular, the inner case <NUM> is made of resin, and the outer case <NUM> is made of metal. Hence, while a portion of the cylinder part 22A of the housing <NUM> that directly supports the base <NUM> is increased in strength, the cylinder part 22A can be reduced in weight.

The outer case <NUM> is formed in a substantially bottomed cylindrical shape open upward. The case bottom 30B of the outer case <NUM> is fastened and fixed to the fixing boss 26N of the inner case <NUM> by the fixing bolt BL. Furthermore, the fixing bolt BL and the fixing boss 26N for fixing the outer case <NUM> to the inner case <NUM> are arranged radially inside the outer peripheral surface of the outer cylinder part 30A. Accordingly, the size of the outer case <NUM> can be reduced compared to a configuration (hereinafter referred to as an electrically-powered trimmer of a comparative example) in which, for example, the upper end of the outer case <NUM> projects radially outward of the outer cylinder part 30A in the same manner as the upper case part <NUM> of the inner case <NUM>, and the projecting portion is fastened and fixed to the upper case part <NUM> of the inner case <NUM>. Accordingly, as the outer case <NUM> can be reduced in weight, the electrically-powered trimmer <NUM> as a whole can be reduced in weight. Compared to the electrically-powered trimmer of the comparative example, there is no longer a need to provide the fixing part for fixing the outer case <NUM> to the upper case part <NUM> of the inner case <NUM>. Accordingly, as the upper case part <NUM> can be reduced in size, the electrically-powered trimmer <NUM> as a whole can be reduced in size.

The upper case part <NUM> is provided at the upper end of the inner case <NUM>. The upper case part <NUM> projects from the outer peripheral surface of the outer case <NUM> (outer cylinder part 30A) as viewed in the up-down direction. Accordingly, the controller <NUM> that drives and controls the motor <NUM> can be arranged in the upper case part <NUM> having a relatively large sectional area compared to the inner cylinder part <NUM>. The battery mounting part 28A can be provided in the upper case part <NUM>, and the battery <NUM> can be attached to the inner case <NUM>.

A lower end portion of the output shaft 34A is supported by the second bearing <NUM>. The second bearing <NUM> is held by the bearing holder <NUM> of the inner case <NUM>. The fixing boss 26N for fastening and fixing the outer case <NUM> is formed on the bearing holder <NUM>. Accordingly, the outer case <NUM> can be fastened and fixed to the inner case <NUM> by utilizing the bearing holder <NUM> that holds the second bearing <NUM>. In other words, the outer case <NUM> can be fastened and fixed to the inner case <NUM> by utilizing a region radially outside the second bearing <NUM> in the inner case <NUM>.

The inner cylinder part <NUM> of the inner case <NUM> is configured to include the small diameter portion 26B and the large diameter portion 26A having a larger diameter than the small diameter portion 26B. An inner peripheral surface of the outer case <NUM> externally inserted onto the inner cylinder part <NUM> is in contact with the large diameter portion 26A. Accordingly, transfer of heat of the motor <NUM> operating in the inner cylinder part <NUM> to the outer case <NUM> can be suppressed by the gap 22B between the outer case <NUM> and the small diameter portion 26B. By the inner peripheral surface of the outer case <NUM> coming into contact with the large diameter portion 26A, rattling of the outer case <NUM> in a state in which the outer case <NUM> is externally inserted onto the inner case <NUM> can be suppressed. Accordingly, while a temperature rise in the outer case <NUM> functioning as a grip gripped by the operator is suppressed, the state in which the outer case <NUM> is externally inserted onto the inner case <NUM> can be well maintained.

In the inner cylinder part <NUM> of the inner case <NUM>, the large diameter portion 26A constitutes the upper end and the lower end of the inner cylinder part <NUM>, and the small diameter portion 26B constitutes the vertically intermediate portion of the inner cylinder part <NUM>. That is, the large diameter portion 26A is arranged on both axial sides of the inner cylinder part <NUM> with respect to the small diameter portion 26B. Accordingly, the outer case <NUM> can be supported by an axial end of the inner cylinder part <NUM>. Accordingly, the state in which the outer case <NUM> is externally inserted onto the inner case <NUM> can be relatively well maintained.

The fan <NUM> rotated by driving the motor <NUM> is provided inside the inner case <NUM>. Furthermore, the upper communication hole <NUM> and the lower communication hole <NUM> are formed in the large diameter portion 26A. Through the upper communication hole <NUM> and the lower communication hole <NUM>, the gap 22B and the inside of the inner case <NUM> communicate with each other. Accordingly, as shown in <FIG>, when the electrically-powered trimmer <NUM> is actuated, the cooling air AR flows into the inner case <NUM> from the intake port 28B of the inner case <NUM> by the airflow generated by the fan <NUM>. The cooling air AR that has flown into the inner case <NUM> is divided at the upper end of the inner cylinder part <NUM> into cooling air AR1 flowing into the upper communication hole <NUM> and cooling air AR2 flowing downward inside the inner cylinder part <NUM>. The cooling air AR1 flows downward through the gap 22B between the small diameter portion 26B of the inner case <NUM> and the outer case <NUM>, and flows into the lower end of the inner cylinder part <NUM> from the lower communication hole <NUM>. The cooling air AR1 and the cooling air AR2 join at the lower end of the inner cylinder part <NUM>, and are discharged to the outside of the housing <NUM> from the inner exhaust port <NUM> and the outer exhaust port 30D. According to the above, while the outer case <NUM> is cooled by the cooling air AR1, the motor <NUM> can be cooled by the cooling air AR2. Accordingly, the outer case <NUM> and the motor <NUM> can be effectively cooled.

A pair of case gouged portions 30F open upward are formed at the upper end of the outer case <NUM>. The trigger <NUM> provided in the inner case <NUM> is arranged inside one case gouged portion 30F, and the lock button <NUM> provided in the inner case <NUM> is arranged inside the other case gouged portion 30F. Accordingly, by matching positions of the case gouged portion 30F, the trigger <NUM> and the lock button <NUM>, the outer case <NUM> can be externally inserted onto the inner case <NUM>. In other words, when the outer case <NUM> is externally inserted onto the inner case <NUM>, an orientation of the outer case <NUM> with respect to the inner case <NUM> in the circumferential direction can be aligned using the case gouged portion 30F, the trigger <NUM>, and the lock button <NUM> as marks. Accordingly, operability in externally inserting the outer case <NUM> onto the inner case <NUM> can be improved.

The protrusion <NUM> protruding radially outward is formed in the inner cylinder part <NUM> of the inner case <NUM>. The engagement groove <NUM> extending in the up-down direction and open upward is formed on the inner peripheral surface of the outer case <NUM>. When the outer case <NUM> is externally inserted onto the inner case <NUM>, the protrusion <NUM> is inserted into the engagement groove <NUM>, and the protrusion <NUM> and the engagement groove <NUM> are engaged in the circumferential direction of the outer case <NUM>. Accordingly, rotation of the outer case <NUM> relative to the inner case <NUM> can be restricted. Thus, positional deviation between the fixing hole 30E and the fixing boss 26N when the fixing bolt BL is screwed to the fixing boss 26N can be suppressed. Accordingly, operability in fastening and fixing the outer case <NUM> to the inner case <NUM> can be improved.

The base <NUM> of the electrically-powered trimmer <NUM> is provided with the fixing mechanism <NUM> that switches between the fixed state in which the base <NUM> is fixed to the housing <NUM> and the released state in which the fixed state is released. Furthermore, the base <NUM> is provided with the holding mechanism <NUM>. The holding mechanism <NUM> holds the base <NUM> in the temporarily fixed state to the housing <NUM> in the released state of the fixing mechanism <NUM>. Specifically, the base <NUM> is held by the holding mechanism <NUM> so that the base <NUM> does not fall under its own weight in the released state of the fixing mechanism <NUM>. That is, the holding mechanism <NUM> functions as a mechanism assisting the fixing mechanism <NUM> in the released state of the fixing mechanism <NUM>, and the holding mechanism <NUM> prevents a fixing force of the base <NUM> with respect to the housing <NUM> from becoming zero immediately. As a result, there is no need for the operator to support the base <NUM> in the released state of the fixing mechanism <NUM>. Accordingly, a suitable fixing structure with respect to the base <NUM> can be realized.

The holding mechanism <NUM> is configured to include the connecting shaft <NUM> connecting the first clamp part 62C and the second clamp part 62D of the base <NUM>, and the holding spring <NUM>. Specifically, the connecting shaft <NUM> is bridged over between the first clamp part 62C and the second clamp part 62D so as to be relatively movable in the axial direction. One end of the connecting shaft <NUM> is engaged with the first clamp part 62C, and movement of the connecting shaft <NUM> toward the other side in the axial direction is restricted. The holding spring <NUM> is attached to the other end portion of the connecting shaft <NUM>, energizes the second clamp part 62D toward one side of the connecting shaft <NUM> in the axial direction, and energizes the other end of the connecting shaft <NUM> toward the other side in the axial direction. Accordingly, by the connecting shaft <NUM> and the holding spring <NUM>, the first clamp part 62C and the second clamp part 62D are pressed inward of the connecting shaft <NUM> in the axial direction, and the base cylinder part <NUM> is deformed in a direction in which the first clamp part 62C and the second clamp part 62D approach each other.

More specifically, if the holding mechanism <NUM> is omitted from the electrically-powered trimmer <NUM>, since a pressing force of the holding spring <NUM> on the second clamp part 62D disappears, the second clamp part 62D (see the second clamp part 62D indicated by a chain dashed line in <FIG>) of the base <NUM> in the released state is greatly displaced toward the other side in the first direction with respect to the second clamp part 62D (see the second clamp part 62D indicated by a chain double-dashed line in <FIG>) of the base <NUM> in the fixed state. In contrast, by providing the holding mechanism <NUM> in the base <NUM>, the pressing force of the holding spring <NUM> acts on the second clamp part 62D. Thus, the second clamp part 62D (see the second clamp part 62D indicated by a solid line in <FIG>) of the base <NUM> in the released state is located on one side in the first direction compared to the case where the holding mechanism <NUM> is omitted. Hence, the clamping force with which the base cylinder part <NUM> tightens the cylinder part 22A of the housing <NUM> and clamps the cylinder part 22A is generated in the base <NUM>. As a result, frictional force is generated between the base cylinder part <NUM> and the cylinder part 22A, and the base <NUM> can be held in a temporarily held state by the frictional force. The term "temporarily held state" herein indicates a state in which the subject is fixed to the extent that it can be moved by hand while its movement under its own weight is suppressed.

In the holding mechanism <NUM>, the adjustment nut <NUM> is screwed to the other end of the connecting shaft <NUM>. The holding spring <NUM> is arranged between the second clamp part 62D and the adjustment nut <NUM>. Accordingly, by rotating the adjustment nut <NUM> relative to the connecting shaft <NUM>, the energization force of the holding spring <NUM> against the second clamp part 62D and the connecting shaft <NUM> can be easily adjusted.

The pinion <NUM> of the lifting mechanism <NUM> is provided on the connecting shaft <NUM> so as to be integrally rotatable therewith. The pinion <NUM> meshes with the first rack <NUM> or the second rack <NUM> of the outer case <NUM>. Accordingly, in the released state of the fixing mechanism <NUM>, by rotating the operation knob 81B of the connecting shaft <NUM>, the base <NUM> can be moved up and down with respect to the housing <NUM>. That is, the connecting shaft <NUM> can be configured as a common part to the holding mechanism <NUM> and the lifting mechanism <NUM>. Accordingly, compared to the case where the connecting shaft <NUM> is not configured as a common part to the holding mechanism <NUM> and the lifting mechanism <NUM>, space occupied by the holding mechanism <NUM> and the lifting mechanism <NUM> can be reduced, and the electrically-powered trimmer <NUM> can be reduced in size.

As described above, one end (stopper 81A) of the connecting shaft <NUM> is engaged with the first clamp part 62C via the first holding washer <NUM>, and movement of the connecting shaft <NUM> toward the other side in the axial direction is restricted. Furthermore, the holding spring <NUM> energizes the other axial end of the connecting shaft <NUM> toward the other side in the axial direction. Accordingly, a shaft holding force for restricting rotation of the connecting shaft <NUM> by the energization force of the holding spring <NUM> is generated in the connecting shaft <NUM>. As described above, the pinion <NUM> is rotatably provided on the connecting shaft <NUM> so as to be integrally rotatable therewith, and the pinion <NUM> meshes with the first rack <NUM> or the second rack <NUM> of the outer case <NUM>. Hence, the shaft holding force generated in the connecting shaft <NUM> is able to act on a portion where the pinion <NUM> meshes with the first rack <NUM> or the second rack <NUM>. That is, the lifting mechanism <NUM> is also able to function as a mechanism that holds the base <NUM> in the temporarily fixed state to the housing <NUM>. Accordingly, the energization force of the holding spring <NUM> can be effectively utilized and the base <NUM> can be held in the temporarily fixed state.

The first rack <NUM> and the second rack <NUM> of the lifting mechanism <NUM> are arranged apart in the circumferential direction of the outer cylinder part 30A. Hence, in the circumferential direction of the cylinder part 22A, a position (hereinafter referred to as first position) of the base <NUM> when the pinion <NUM> meshes with the first rack <NUM> and a position (hereinafter referred to as second position) of the base <NUM> when the pinion <NUM> meshes with the second rack <NUM> can be set to different positions. Hence, the lifting mechanism <NUM> is able to function with the base <NUM> arranged in the first position or the second position according to a work mode of the operator. Accordingly, operability with respect to the operator can be improved.

As described above, in the circumferential direction of the cylinder part 22A of the housing <NUM>, a plurality of racks (first rack <NUM> and second rack <NUM>) are formed in the outer cylinder part 30A. Furthermore, the width length of each of the first rack <NUM> and the second rack <NUM> along the circumferential direction of the cylinder part 22A is set greater than the width length of the pinion <NUM>. Hence, an entire rack length (the sum of the width lengths of the first rack <NUM> and the second rack <NUM>) along the circumferential direction of the cylinder part 22A is set to be at least twice the width length of the pinion <NUM>. That is, the term "entire rack length along the circumferential direction of a cylinder part" in the present invention refers to, if a plurality of racks (first rack <NUM> and second rack <NUM>) are formed in the outer cylinder part 30A, the sum of width lengths of the plurality of racks (first rack <NUM> and second rack <NUM>), as in the present embodiment. Accordingly, as described above, the position of the base <NUM> in the circumferential direction of the outer cylinder part 30A can be changed and the lifting mechanism <NUM> can be utilized.

In the present embodiment, since the trigger <NUM> is provided in the outer cylinder part 30A (grip), the motor <NUM> can be quickly turned on and off during work with one hand. Even if a gripped state is released during operation of the trigger <NUM>, since the motor <NUM> stops, damage to the workpiece can be reduced. Furthermore, since the motor <NUM> can be maintained in the on state by an operation on the lock button <NUM>, work can be continued even if an operating force on the trigger <NUM> is canceled, and fatigue during work can be reduced. Since off lock control can be executed so that, as long as the lock button <NUM> is not operated, the motor <NUM> will not be driven even if the trigger <NUM> is operated, even if foreign matter comes into contact with the trigger <NUM> when no work is being performed, the motor <NUM> is not driven, and an adverse effect such as wasteful energy consumption can be reduced. Furthermore, by a configuration in which transition to the on lock state can be performed in the same manner by the lock button <NUM> that releases the off lock state, the number of parts of a control switch can be reduced, and the transition from the off lock release state to the on lock state can be performed in the same gripped state. In particular, in the present embodiment, since it is possible to make a transition from the off lock release state to the on lock state by an operation with two fingers in the gripped state, operability can be greatly improved.

In the present embodiment, by inserting the fixing bolt BL into the fixing hole 30E of the outer case <NUM> from below and screwing the fixing bolt BL to the fixing boss 26N of the inner case <NUM>, the outer case <NUM> is fastened and fixed to the inner case <NUM>. That is, the fixing bolt BL extends in the up-down direction. Alternatively, for example, the fixing bolt BL may be arranged at a lower end of the cylinder part 22A so as to extend in the first direction or the second direction, and the inner case <NUM> and the outer case <NUM> may be fastened and fixed.

In the holding mechanism <NUM> of the present embodiment, the clamping force that clamps the cylinder part 22A of the housing <NUM> is generated in the base <NUM>, and the base <NUM> is held in the temporarily fixed state to the housing <NUM>. However, a mechanism holding the base <NUM> in the temporarily fixed state is not limited to the above. For example, although illustration is omitted, at least one of the outer peripheral surface of the outer cylinder part 30A of the outer case <NUM> and the inner peripheral surface of the base cylinder part <NUM> of the base <NUM> may be provided with a high friction member having a relatively high friction coefficient, and the base <NUM> may be held in the temporarily fixed state by frictional force generated between the base cylinder part <NUM> and the outer cylinder part 30A. The holding spring <NUM> is located on the outer periphery of the connecting shaft <NUM> and configured to bring the first clamp part 62C and the second clamp part 62D close to each other. However, the holding spring <NUM> may also be provided on the fixing shaft <NUM>. For example, the following configuration is possible: while the fixing pin <NUM> is increased in size in the axial direction, the holding spring <NUM> is interposed between the fixing pin <NUM> and the second fixing washer <NUM>, and energization force is exerted on the fixing pin <NUM> and the second fixing washer <NUM>.

For example, as shown in <FIG>, one of the outer cylinder part 30A and the base cylinder part <NUM> may be provided with a holding spring <NUM> and a pressing member <NUM> as energization members, frictional force may be generated between the outer cylinder part 30A and the base cylinder part <NUM>, and the base <NUM> may be held in the temporarily fixed state by the frictional force (in the example shown in <FIG>, the holding spring <NUM> and the pressing member <NUM> are provided in the base cylinder part <NUM>). Specifically, a recess open toward the outer cylinder part 30A is formed in the base cylinder part <NUM>, and the holding spring <NUM> and the pressing member <NUM> are arranged in the recess. The holding spring <NUM> is configured as a compression coil spring, and presses the pressing member <NUM> toward the outer cylinder part 30A. Accordingly, frictional force is generated between the pressing member <NUM> and the outer cylinder part 30A, and the base <NUM> can be held in the temporarily fixed state. Although a material of the pressing member <NUM> is not particularly defined, a holding force with respect to the base <NUM> can further be increased by using an elastic member such as rubber.

In the present embodiment, two racks (first rack <NUM> and second rack <NUM>) are formed in the outer cylinder part 30A of the housing <NUM>. However, three or more racks may be formed in the outer cylinder part 30A, or one rack may be formed in the outer cylinder part 30A. If one rack is formed in the outer cylinder part 30A, the width length of the rack along the circumferential direction of the cylinder part 22A is set to be at least twice the width length of the pinion <NUM>. For example, the width of the rack is set to <NUM>/<NUM> of the entire circumference of the outer cylinder part 30A. Accordingly, in this case, the entire rack length along the circumferential direction of the cylinder part 22A is set to be at least twice the width length of the pinion <NUM>. Hence, even if one rack is formed in the outer cylinder part 30A, the position of the base <NUM> in the circumferential direction of the outer cylinder part 30A can be changed by the lifting mechanism <NUM>.

In the present embodiment, the first rack <NUM> and the second rack <NUM> are formed in the housing <NUM>, and the pinion <NUM> is provided in the base <NUM>. However, a configuration is possible in which the pinion <NUM> is provided in the housing <NUM> and the first rack <NUM> and the second rack <NUM> are formed in the base <NUM>.

In the electrically-powered trimmer <NUM> configured as described above, the fixing mechanism <NUM> is provided that switches between the fixed state in which the base <NUM> is fixed to the housing <NUM> and the released state in which the fixed state is released. The fixing mechanism <NUM> is configured to include the upper-lower pair of fixing shafts <NUM> bridged over between the first clamp part 62C and the second clamp part 62D of the base <NUM>, a pair of cam parts 75B connected to the other end of the fixing shaft <NUM>, and a pair of fixing washers (second fixing washers) <NUM> provided at the other end of the fixing shaft <NUM>.

When the clamp lever <NUM> of the fixing mechanism <NUM> is rotated from the release position toward the fixing position, the cam surface 75C of the cam part 75B contacts the washer contact part 74A of the second fixing washer <NUM>, and presses the washer contact part 74A toward one side in the first direction. Accordingly, the washer pressing part 74B of the second fixing washer <NUM> presses the second clamp part 62D toward one side in the first direction. In the rotation of the clamp lever <NUM> toward the fixing position, a pressing amount of the cam part 75B to the second fixing washer <NUM> increases as the clamp lever <NUM> is rotated. On the other hand, one end of the fixing shaft <NUM> is engaged with the first clamp part 62C via the fixing nut <NUM> and the first fixing washer <NUM> (engagement washer <NUM>), and movement of the fixing shaft <NUM> toward the other side in the axial direction is restricted. Hence, in the fixing position of the clamp lever <NUM>, a pressing force (corresponding to the fixing force of the present invention) is imparted from the second fixing washer <NUM> to the second clamp part 62D. Accordingly, the second clamp part 62D is displaced toward the first clamp part 62C, and the base cylinder part <NUM> is deformed. As a result, the clamping force that tightens the cylinder part 22A of the housing <NUM> is generated in the base cylinder part <NUM>, and the base <NUM> is fixed to the housing <NUM> by the clamping force.

Here, in the fixing mechanism <NUM>, the fixing shaft <NUM> is bridged over between the upper end and the lower end of each of the first clamp part 62C and the second clamp part 62D of the base <NUM>. The cam part 75B and the second fixing washer <NUM> are provided on each of the pair of fixing shafts <NUM>. Accordingly, both longitudinal ends of the first clamp part 62C and the second clamp part 62D can be sandwiched by the fixing mechanism <NUM>. In other words, in the fixed state of the fixing mechanism <NUM>, the pressing force input to the second clamp part 62D from the second fixing washer <NUM> for deforming the base cylinder part <NUM> acts on each of an upper portion (upper end) and a lower portion (lower end) of the second clamp part 62D. Hence, compared to, for example, a configuration (hereinafter, the electrically-powered trimmer of this configuration is referred to as the electrically-powered trimmer of the comparative example) in which the pressing force imparted from the second fixing washer <NUM> to the second clamp part 62D is imparted to one place in a longitudinal intermediate portion of the second clamp part 62D, the base cylinder part <NUM> can be well deformed over the entire axial direction. Accordingly, compared to the electrically-powered trimmer of the comparative example, the clamping force of the base cylinder part <NUM> that clamps the cylinder part 22A is able to act uniformly in the axial direction of the base cylinder part <NUM>. Accordingly, the base <NUM> can be stably fixed to the housing <NUM>. In particular, in the present embodiment, since the pressing force acting on the upper portion and the lower portion of the second clamp part 62D acts in a range of <NUM>% of the upper portion and <NUM>% of the lower portion in an extension range of the second clamp part 62D, the possibility that the fixing force at upper and lower ends of the second clamp part 62D may be insufficient can be reduced. Furthermore, in the case where the lower portion of the second clamp part 62D is located below the lower end of the inner cylinder part <NUM>, although there is a possibility that the fixing force with respect to the lower portion of the second clamp part 62D may be insufficient, attenuation of the fixing force can be compensated for by the pressing force acting on the upper portion of the second clamp part 62D. In the present embodiment, the pressing force is generated in the upper portion (upper end) and the lower portion (lower end) of the second clamp part 62D by the pair of fixing shafts <NUM>. However, a means may be provided of generating a pressing force in the upper portion and the lower portion of the second clamp part 62D while there is only one fixing shaft.

The fixing mechanism <NUM> includes the clamp lever <NUM>, and the clamp lever <NUM> includes an upper-lower pair of cam parts 75B. In other words, the pair of cam parts 75B connected to the fixing shaft <NUM> are connected by the clamp lever <NUM>. Accordingly, by rotating the clamp lever <NUM>, the pair of cam parts 75B can be actuated at the same time. Accordingly, even if the fixing mechanism <NUM> is configured to include a pair of fixing shafts <NUM>, a pair of second fixing washers <NUM>, and a pair of cam parts 75B, complexity for the operator when operating the fixing mechanism <NUM> can be reduced.

The connecting groove 71A open toward the other side in the axial direction is formed at the other end of the fixing shaft <NUM>. The cam part 75B is arranged in the connecting groove 71A and is rotatably connected with the fixing shaft <NUM>. Accordingly, compared to, for example, a configuration in which the connecting groove 71A is omitted from the fixing shaft <NUM>, a pair of cam parts 75B are arranged on both sides of the fixing shaft <NUM> in the up-down direction with respect to one fixing shaft <NUM>, and the cam part 75B and the fixing shaft <NUM> are connected, an increase in size of the fixing mechanism <NUM> in the up-down direction can be suppressed.

The second fixing washer <NUM> is configured to include the washer contact part 74A extending in the second direction, and the washer pressing part 74B formed in an annular shape and to which both longitudinal ends of the washer contact part 74A are connected. The washer contact part 74A is inserted into the connecting groove 71A of the fixing shaft <NUM> and configured to be able to contact the cam part 75B. The washer pressing part 74B is externally inserted onto the fixing shaft <NUM> and configured to be able to press the second clamp part 62D. Accordingly, the pressing force of the cam part 75B on the second fixing washer <NUM> is input to a central portion of the second fixing washer <NUM>, the input pressing force is uniformly transmitted in the circumferential direction of the washer pressing part 74B, and the second clamp part 62D can be pressed by the washer pressing part 74B.

The base cylinder part <NUM> is provided with the connecting shaft <NUM> between the upper-lower pair of fixing shafts <NUM>. The pinion <NUM> constituting the lifting mechanism <NUM> is provided on the connecting shaft <NUM> so as to be integrally rotatable therewith. The pinion <NUM> meshes with the first rack <NUM> or the second rack <NUM> formed in the outer case <NUM>. Accordingly, a region between the upper-lower pair of fixing shafts <NUM> can be effectively utilized, and the lifting mechanism <NUM> for changing the position of the base <NUM> with respect to the housing <NUM> can be provided.

Modification <NUM> of the fixing mechanism <NUM> is described below with reference to <FIG>. Modification <NUM> of the fixing mechanism <NUM> is configured in the same manner as the fixing mechanism <NUM> of the present embodiment except for the following points. That is, in Modification <NUM> of the fixing mechanism <NUM>, a pair of clamp levers <NUM> are provided corresponding to a pair of fixing shafts <NUM> (not shown in <FIG>). The clamp lever <NUM> is formed in a substantially rectangular shape with the first direction as the longitudinal direction as viewed from one side in the second direction. Although illustration is omitted, the connecting groove 71A is omitted from the fixing shaft <NUM>. The cam part 75B of the clamp lever <NUM> is arranged above and below the other end of the fixing shaft <NUM>, and is rotatably connected to the fixing shaft <NUM> by the fixing pin <NUM> with the up-down direction as the axial direction. The washer contact part 74A is omitted from the fixing washer <NUM>.

By rotating the upper and lower clamp levers <NUM> from the release position to the fixing position, as in the present embodiment, both longitudinal ends of the first clamp part 62C and the second clamp part 62D of the base cylinder part <NUM> can be sandwiched by the fixing mechanism <NUM>. Accordingly, the clamping force of the base cylinder part <NUM> that clamps the cylinder part 22A is able to act uniformly in the axial direction of the base cylinder <NUM>. Accordingly, in Modification <NUM> of the fixing mechanism <NUM>, the base <NUM> can be stably fixed to the housing <NUM>.

In Modification <NUM> of the fixing mechanism <NUM>, the clamp lever <NUM> is provided corresponding to each of the pair of fixing shafts <NUM>. Hence, the pressing force imparted from the fixing washer <NUM> on the upper side to the second clamp part 62D and the pressing force imparted from the fixing washer <NUM> on the lower side to the second clamp part 62D can be fine-tuned.

In Modification <NUM>, the fixing mechanism <NUM> includes two fixing shafts <NUM>, two cam parts 75B, two fixing washers <NUM>, and two clamp levers <NUM>. However, the fixing mechanism <NUM> may be configured to include three or more of each component.

Modification <NUM> of the fixing mechanism <NUM> is described below with reference to <FIG> and <FIG>. Modification <NUM> of the fixing mechanism <NUM> is configured in the same manner as the fixing mechanism <NUM> of the present embodiment except for the following points. That is, in Modification <NUM> of the fixing mechanism <NUM>, instead of the pair of fixing shafts <NUM>, the connecting shaft <NUM> of the holding mechanism <NUM> is configured as a fixing shaft of the fixing mechanism <NUM>. In Modification <NUM> of the fixing mechanism <NUM>, the clamp lever <NUM> is formed in a substantially rectangular shape with the first direction as the longitudinal direction as viewed from one side in the second direction. The cam part 75B of the clamp lever <NUM> is arranged above and below the other end of the connecting shaft <NUM>, and is rotatably connected to the connecting shaft <NUM> by the fixing pin <NUM> with the up-down direction as the axial direction.

In Modification <NUM>, instead of the first fixing washer <NUM> (engagement washer <NUM>), an engagement washer <NUM> is provided at one end of the connecting shaft <NUM>. The engagement washer <NUM> is formed in a substantially rectangular plate shape with the first direction as the plate thickness direction and the up-down direction as the longitudinal direction. One end portion of the connecting shaft <NUM> is inserted through a longitudinal intermediate portion of the engagement washer <NUM>, and the stopper 81A of the connecting shaft <NUM> is engaged with the engagement washer <NUM>. A restriction part 173A is formed at both longitudinal ends of the engagement washer <NUM>. The restriction part 173A protrudes toward the other side in the first direction and is in contact with the upper end and the lower end of the first clamp part 62C. Accordingly, movement of the connecting shaft <NUM> toward the other side in the second direction is restricted.

In Modification <NUM>, instead of the fixing washer <NUM>, a fixing washer <NUM> as a pressing member is provided at the other end of the connecting shaft <NUM>. The fixing washer <NUM> is formed in a substantially rectangular plate shape with the first direction as the plate thickness direction and the up-down direction as the longitudinal direction. The other end portion of the connecting shaft <NUM> is inserted through a longitudinal intermediate portion of the fixing washer <NUM>, and the fixing washer <NUM> is arranged between the second clamp part 62D and the cam part 75B of the clamp lever <NUM>. In the fixed state of the fixing mechanism <NUM>, the cam part 75B may press the fixing washer <NUM> toward one side in the first direction.

A pushing part 174A as a fixing force imparting part is formed at both longitudinal ends of the fixing washer <NUM>. The pushing part 174A protrudes toward one side in the first direction and is arranged adjacent to the upper end and the lower end of the second clamp part 62D on the other side in the first direction.

When the clamp lever <NUM> of the fixing mechanism <NUM> is rotated from the release position to the fixing position, the cam part 75B presses the fixing washer <NUM> toward one side in the first direction. Accordingly, a pair of pushing parts 174A of the fixing washer <NUM> presses the upper end and the lower end of the second clamp part 62D toward one side in the first direction. Hence, in Modification <NUM> of the fixing mechanism <NUM>, both longitudinal ends of the first clamp part 62C and the second clamp part 62D of the base cylinder part <NUM> can be sandwiched by the fixing mechanism <NUM>. Accordingly, the clamping force of the base cylinder part <NUM> that clamps the cylinder part 22A is able to act uniformly in the axial direction of the base cylinder part <NUM>. Accordingly, in Modification <NUM> of the fixing mechanism <NUM>, the base <NUM> can be stably fixed to the housing <NUM>.

That is, in Modification <NUM> of the fixing mechanism <NUM>, the connecting shaft <NUM> of the holding mechanism <NUM> is configured as the fixing shaft of the fixing mechanism <NUM>. Hence, the number of parts can be reduced, and the cost of the electrically-powered trimmer <NUM> can be reduced.

In the present embodiment, the fixing mechanism <NUM> is configured to impart the pressing force to the second clamp part 62D, and the clamping force that tightens the cylinder part 22A of the housing <NUM> is configured to act on the base cylinder part <NUM>. However, the configuration of the fixing mechanism <NUM> is not limited thereto. For example, although illustration is omitted, the fixing mechanism <NUM> may be configured as a toggle mechanism, and the fixing force imparting parts that impart the fixing force for fixing the cylinder part 22A may be arranged apart in the up-down direction.

Claim 1:
A work machine (<NUM>) comprising:
a motor (<NUM>);
an output shaft (34A) rotated by the motor (<NUM>), to which a tip tool (T) is attachable;
a housing (<NUM>), configured to comprise an inner case (<NUM>) comprising an accommodation part (<NUM>) that accommodates the motor (<NUM>) and an outer case (<NUM>) located outside the accommodation part (<NUM>); and
a base (<NUM>), attachable to and detachable from a mounting surface formed on a side surface of the outer case (<NUM>) and having a contact surface able to contact a workpiece,
characterized in that
the inner case (<NUM>) is provided with a fixing part (26N), the outer case (<NUM>) is fixed to the inner case (<NUM>) by a fixing member (BL) attached to the fixing part (26N), and the fixing part (26N) is arranged inside the mounting surface in a radial direction of the motor (<NUM>) as viewed in an axial direction of the motor (<NUM>).