JP7715985B2 - Work equipment - Google Patents

Description

The present invention relates to a work machine.

The electric reciprocating tool (working machine) described in Patent Document 1 below is composed of a motor, a screw shaft connected to the motor, a shuttle screw threadedly engaged with the screw shaft, and a movable blade attached to the shuttle screw. When the motor is driven, the shuttle screw moves axially relative to the screw shaft, causing the movable blade to reciprocate back and forth. This allows cutting to be performed on a workpiece placed in front of the movable blade.

Japanese Patent Application Laid-Open No. 2001-277039

However, in the above-mentioned electric reciprocating tool, power is transmitted through a screw engagement, which can cause the movable blade to rotate around the axis of the screw shaft, potentially reducing workability. Furthermore, when using the above-mentioned electric reciprocating tool to cut a workpiece, changing the orientation of the movable blade relative to the workpiece requires changing the orientation of the entire electric reciprocating tool relative to the workpiece. This can potentially reduce workability.

In consideration of the above, the present invention aims to provide a work machine that can improve workability.

One or more embodiments of the present invention include a motor, a housing that accommodates the motor, an output section that is rotated by the motor, a moving member that is threadedly engaged with the output section and moves as the output section rotates, a blade that is supported by the moving member and that can reciprocate between an initial position and an inverted position as the moving member moves, and a guide mechanism that is configured to sandwich the blade, is rotatably supported by the housing around the movement direction of the moving member, and restricts the rotation of the blade around the movement direction of the moving member as an axis, and the guide mechanism and the moving member are capable of relative rotation around the movement direction of the moving member, and are each attached to the housing. The guide mechanism is configured to rotate around the direction of movement of the movable member, and the blade is configured to rotate together with the movable member around the direction of movement of the movable member when the guide mechanism is rotated relative to the housing, the outer surface of the blade and the inner surface of the guide mechanism can be separated, and when the blade is operated by the motor, the blade comes into contact with the inner surface of the guide mechanism, thereby guiding the movement of the movable member in the direction of movement while restricting the rotation of the blade around the axis of the direction of movement of the movable member, and a stopper is provided on the housing that restricts the rotation of the guide mechanism within a predetermined angle range when the guide mechanism is in a state where it can be rotated by an operator.

In one or more embodiments of the present invention, the guide mechanism is a work machine having a guide portion that can come into contact with the blade.

In one or more embodiments of the present invention, the guide portion is located at a distance from the movable member in a direction perpendicular to the direction of movement of the movable member.

One or more embodiments of the present invention are working machines configured so that at least a portion of the blade positioned in the inverted position can abut against the guide mechanism.

One or more embodiments of the present invention include a head portion capable of supporting a workpiece to be cut by the blade,
The head portion is configured to clamp the blade positioned at the reversal position, and the guide portion is a work machine that regulates the rotation of the blade so that the blade does not come into contact with the head portion as it moves from the initial position to the reversal position.

One or more embodiments of the present invention are a work machine comprising: a motor; a housing that accommodates the motor; a movable member that moves in a first direction by the driving force of the motor; a tool bit connected to the movable member; a guide portion that restricts rotation of the tool bit about an axis in the first direction and guides movement of the tool bit along the first direction; and an engaging portion that is engageable with a workpiece, and is connected to the housing ; the guide mechanism and the movable member are configured to be rotatable relative to each other about an axis in the first direction , and each is configured to be rotatable relative to the housing about an axis in the first direction; when the guide mechanism is rotated relative to the housing, the tool bit is urged by the guide mechanism that rotates relative to the movable member, causing the movable member to rotate relative to the housing about an axis in the first direction;

One or more embodiments of the present invention are a work machine in which the guide mechanism is connected to the housing so as to be rotatable around the first direction as an axis , and when the guide mechanism rotates , the guide mechanism rotates relative to the housing, changing the orientation of the tool bit.

In one or more embodiments of the present invention, the housing accommodates an output shaft connected to the motor, the moving member is threadedly engaged with the output shaft, and when the output shaft rotates due to the driving force of the motor, the moving member moves in the axial direction of the output shaft, and when the guide mechanism rotates around an axis in the first direction , the guide mechanism and the tool bit rotate around an axis in the first direction .

In one or more embodiments of the present invention, the tool bit is a plate-shaped blade, and the guide mechanism is a work machine including: a rotary shaft rotatably connected to the housing and arranged coaxially with the output shaft; and a pair of guide members rotatably connected to the rotary shaft and sandwiching the tool bit to limit rotation of the tool bit around the axis of the output shaft.

In one or more embodiments of the present invention, the rotating shaft is cylindrical, and the moving member is movably supported on the rotating shaft.

In one or more embodiments of the present invention, the housing is provided with a stopper that defines a rotation range of the guide mechanism.

One or more embodiments of the present invention are a work machine comprising: a motor; a housing that accommodates the motor; a movable member that moves in a first direction by the driving force of the motor; a tool bit connected to the movable member; a guide portion that restricts rotation of the tool bit around the first direction as an axis and guides movement of the tool bit along the first direction; and an engaging portion that can engage with a workpiece, and a guide mechanism that is rotatably connected to the housing, wherein the housing is provided with a stopper that defines the rotation range of the guide mechanism, and the stopper is provided with a magnet that is configured to be able to abut against the guide mechanism, and the abutment state between the guide mechanism and the stopper is maintained by the magnetic force of the magnet.

One or more embodiments of the present invention are a work machine in which a movement limiting member is provided between the housing and the guide mechanism, and the movement limiting member limits the relative rotation of the guide mechanism with respect to the housing around the first direction as an axis when the motor is driven, and allows the relative rotation of the guide mechanism with respect to the housing around the first direction as an axis when an operating force greater than or equal to a predetermined value is applied to the guide mechanism by an operator.

In one or more embodiments of the present invention, the movement limiting member limits the relative rotation of the guide mechanism with respect to the housing when the motor is driven by a frictional force generated between the housing and the guide mechanism.

One or more embodiments of the present invention are a work machine in which the movement limiting member is arranged to be movable integrally with the guide mechanism, the movement limiting member has a locking portion formed thereon, and the locking portion is directly or indirectly locked to the housing at an intermediate position within the operating range of the guide mechanism, thereby restricting the relative rotation of the guide mechanism with respect to the housing.
One or more embodiments of the present invention include a motor, a housing that accommodates the motor, a screw portion that rotates by the motor in a first rotation direction or a second rotation direction that is opposite to the first rotation direction, with a first direction as an axis, a moving member that threads with the screw portion and moves in one direction of the first direction by rotation of the screw portion in the first rotation direction and moves in the other direction of the first direction by rotation of the screw portion in the second rotation direction, thereby being driven to reciprocate along the first direction by the driving force of the motor, a tool bit that is connected to the moving member and moves in the first direction integrally with the moving member, and a tool bit that moves when the screw portion rotates in the first rotation direction. and a guide portion that restricts the tool bit from rotating about an axis in the first direction when the rotational force of the motor is transmitted to move the moving member in the first direction, whether the tool bit rotates in the first direction or when the screw portion rotates in the second rotation direction. Even when the tool bit is restricted from rotating about an axis in the first direction by the guide portion and the moving member can be moved by the motor via the screw portion , the tool bit can rotate about an axis in the first direction when an operator applies a biasing force to the tool bit such that the tool bit rotates about an axis in the first direction.
One or more embodiments of the present invention provide a working machine comprising: a motor; a housing that accommodates the motor; a movable member that moves in a first direction by the driving force of the motor; a tool bit connected to the movable member; a guide portion that transmits the rotational force of the motor to restrict the tool bit from rotating about the first direction as an axis; and an elastic member that restricts relative rotation of the guide portion with respect to the housing about the first direction as an axis by a biasing force, wherein even when the rotation of the tool bit about the first direction as an axis is restricted by the guide portion, the tool bit can rotate about the first direction as an axis when an operator applies a biasing force to the tool bit such that the tool bit rotates about the first direction as an axis; and even when the rotation of the guide portion with respect to the housing about the first direction as an axis is restricted by the biasing force of the elastic member, the operator can directly bias the guide portion to rotate the guide portion relative to the housing about the first direction as an axis, and the tool bit can be used to perform work in this state.
In one or more embodiments of the present invention, the guide portion guides movement of the tool bit along the first direction.
One or more embodiments of the present invention are a work machine comprising: a motor; a housing that accommodates the motor; an output section that rotates by the motor; a movable member that is threadedly engaged with the output section and moves as the output section rotates; a blade that is supported by the movable member and can move back and forth between an initial position and an inverted position as the movable member moves; and an adjustment mechanism that has a pair of plate members that sandwich the blade and is rotatably supported on the housing around the direction of movement of the movable member, wherein the rotational position of the blade around the direction of movement can be adjusted by rotating the adjustment mechanism, and a stopper is provided on the housing that limits the rotation of the movable member to a predetermined angle range when the adjustment mechanism is capable of being rotated by an operator.

A work machine with the above configuration can improve workability.

FIG. 2 is a side view showing the electric cutting machine according to the embodiment, as viewed from the right side. 2 is a cross-sectional view showing the inside of the electric cutting machine shown in FIG. 1 as viewed from the right side. (A) is a cross-sectional view from the front showing the support mechanism shown in Figure 2 (cross-sectional view taken along line 3A-3A in Figure 2), and (B) is a cross-sectional view from the front showing the connection state between the lifter and blade shown in Figure 2 (cross-sectional view taken along line 3B-3B in Figure 2). (A) is a cross-sectional view from above showing the connection state between the lifter and blade shown in Figure 2 (cross-sectional view along line 4A-4A in Figure 2), and (B) is a cross-sectional view from above showing the connection state between the guide plate and head plate shown in Figure 2 (cross-sectional view along line 4B-4B in Figure 2). 3 is a cross-sectional view seen from the right side showing a state in which the lifter and the blade shown in FIG. 2 have moved to an inverted position. FIG. 2 is a right side view showing the blade and guide mechanism shown in FIG. 1 rotated from a first position to a second position; FIG. 4 is a flowchart for explaining the operation of the electric cutter according to the present embodiment. 4 is a time chart for explaining the operation of the electric cutter according to the present embodiment. (A) is a side view from the right side showing a mechanism for holding the guide mechanism at an intermediate position between the first position and the second position, and (B) is a side view showing the guide mechanism held at the intermediate position. 10 is a three-view diagram of the fix washer shown in FIG. 9.

The following describes the electric cutting machine 10 as a work machine according to this embodiment, using the drawings. Note that the arrows UP, FR, and RH shown as appropriate in the drawings indicate the upper side, front side, and right side of the electric cutting machine 10, respectively. In the following description, when the up/down, front/rear, and left/right directions are used, they refer to the up/down direction, front/rear direction, and left/right direction of the electric cutting machine 10, unless otherwise specified. The front/rear direction corresponds to the first direction in the present invention.

As shown in Figures 1 and 2, the electric cutter 10 is configured as an electric tool for cutting a workpiece W, such as a light-weight ceiling bar used in suspended ceilings in buildings. The workpiece W is formed in the shape of a long column, and is formed into a roughly U-shape when viewed longitudinally. The electric cutter 10 includes a housing 20, a motor 50, a feed screw mechanism 60 (broadly speaking, an element that can be understood as a movement mechanism), a blade 72 serving as a cutting edge (tip tool), a guide mechanism 80, a holding mechanism 90, and a control unit 100. Each component of the electric cutter 10 will be described below.

(Regarding the housing 20)
The housing 20 forms the outer shell of the electric cutter 10 and extends in the front-to-rear direction as a whole. The housing 20 includes a lifter housing 22 (first housing) that forms the front portion of the housing 20 and a main housing 24 (second housing) that forms the rear portion of the housing 20. The main housing 24 is formed in a hollow, approximately inverted P-shape when viewed from the right side, and the lifter housing 22 is formed in a generally cylindrical shape that extends in the front-to-rear direction. The front end of the main housing 24 and the rear end of the lifter housing 22 are connected via a spacer 26.

The rear end of the main body housing 24 is configured as a handle 24A that is gripped by the operator and extends in the vertical direction. A trigger 30 serving as an operating part is provided at the upper end of the handle 24A. The trigger 30 is configured to be pulled rearward and turns on when pulled. A trigger switch 31 is also provided on the handle 24A, diagonally below and rearward of the trigger 30. When the trigger 30 is pulled, the trigger switch 31 switches from an off state to an on state.

The trigger switch 31 is electrically connected to the control unit 100, which is described below, and the control unit 100 is housed at the bottom end of the main body housing 24. When the trigger switch 31 is turned on, it outputs an on signal to the control unit 100.

A battery mounting section 24B is formed at the bottom end of the main body housing 24. A battery terminal 28 is provided in the battery mounting section 24B, and the battery terminal 28 is electrically connected to the control unit 100, which will be described later. A battery 32 is detachably mounted in the battery mounting section 24B, and the battery 32 has a connector (not shown) that connects to the battery terminal 28. This allows power to be supplied to the motor 50, which will be described later, via the control unit 100.

The lifter housing 22 has an inseparable, one-piece structure and is formed in a generally cylindrical shape. As shown in FIG. 3(A), the front end 23 of the lifter housing 22 is formed so that it is spaced apart in the left-right direction. A pair of upper and lower flange portions 23A are formed on the front end 23 of the lifter housing 22, and the flange portions 23A extend outward in the vertical direction from the front end 23.

A support mechanism 40 is provided at the front end 23 of the lifter housing 22 to support the lifter 65 of the feed screw mechanism 60, which will be described later. The support mechanism 40 will be described below.

(Regarding the support mechanism 40)
As shown in Figures 2, 3(A), and 4(A), the support mechanism 40 is composed of a pair of left and right fixed plates 41, an outer guide 44 (broadly speaking, an element that can be understood as a support member), and an inner guide 45 that serves as a rotation axis.

The fixed plate 41 is formed as a generally elongated plate with its thickness extending left-right and its length extending up-down. A curved portion 41A is formed in the vertical middle of the fixed plate 41, and when viewed from the front, the curved portion 41A is formed as a generally arcuate shape that convexes outward in the left-right direction to correspond to the outer shape of the lifter housing 22. The fixed plate 41 is positioned left-right inside the front end 23 of the lifter housing 22, and the upper and lower ends of the fixed plate 41 are positioned adjacent to the left-right inside of the flange portion 23A of the lifter housing 22.

A sleeve 42 is fitted across the upper and lower ends of a pair of left and right fixing plates 41. The sleeve 42 is formed in a roughly cylindrical shape with its axial direction extending in the left-right direction, and the pair of fixing plates 41 are fixed to the sleeve 42. Both longitudinal ends of the sleeve 42 protrude outward in the left-right direction beyond the fixing plates 41, and insertion holes 23B are formed through the lifter housing 22, into which both longitudinal ends of the sleeve 42 are inserted. A nut 43 is provided at the left end of the sleeve 42. A bolt BL1 is inserted into the sleeve 42 from the right side and threaded onto the nut 43. This secures the fixing plate 41 to the lifter housing 22.

The outer guide 44 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction. The outer guide 44 is disposed between the curved portions 41A of a pair of fixing plates 41. The left and right ends of the outer guide 44 are fastened to the curved portions 41A of the left and right fixing plates 41 by a pair of front and rear bolts BL2. When the outer guide 44 is fixed to the fixing plates 41, the tip of the bolt BL2 protrudes radially inward from the outer guide 44. In this state, the head of the bolt BL2 is disposed within the cutout 23C formed in the lifter housing 22 (see Figure 1).

The inner guide 45 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction. The outer diameter of the inner guide 45 is slightly smaller than the inner diameter of the outer guide 44, and the axial length of the inner guide 45 is longer than the axial length of the outer guide 44. The rear portion of the inner guide 45 is rotatably inserted into the outer guide 44. A pair of front and rear guide grooves 45A are formed on the outer periphery of the rear portion of the inner guide 45. The guide grooves 45A extend circumferentially around the inner guide 45 and are formed around the entire circumference of the inner guide 45. The tip of the bolt BL2 is inserted into the guide groove 45A to allow relative rotation of the inner guide 45 with respect to the outer guide 44. As a result, the bolt BL2 limits the movement of the inner guide 45 in the front-to-rear direction.

As shown in Figure 3(B), a pair of upper and lower slits 45B are formed in the front portion of the inner guide 45 for positioning the blade 72, which will be described later. The slits 45B extend in the front-to-rear direction and penetrate in the up-to-down direction, with the front end of the slits 45B opening to the front. The inner guide 45 also constitutes part of the guide mechanism 80, which will be described later.

(Regarding the motor 50)
As shown in FIG. 2 , the motor 50 is configured as a brushless motor and is housed in the front end of the main body housing 24. The motor 50 includes a drive shaft 51 whose axial direction is the front-to-rear direction, a substantially cylindrical rotor 52 fixed to the drive shaft 51, and a substantially cylindrical stator 53 disposed radially outward of the rotor 52. The rear end of the drive shaft 51 is rotatably supported by a motor bearing 54 held in the main body housing 24, and the front end portion of the drive shaft 51 is rotatably supported by a motor bearing 55 held in the spacer 26. A pinion gear 51A is formed on the front end of the drive shaft 51. The motor 50 is electrically connected to the control unit 100 and is driven under the control of the control unit 100.

(Regarding the lead screw mechanism 60)
As shown in Figures 2 and 5, the feed screw mechanism 60 is composed of a transmission gear 61, a drive shaft 63 as an output shaft (output part), a lifter 65 as a moving member, and a lifter detection switch 68 as a position detection part for detecting the position of the lifter 65.

The transmission gear 61 is formed in a roughly stepped cylindrical shape with its axial direction extending in the front-to-rear direction, and the diameter of the front part of the transmission gear 61 is set larger than the diameter of the rear part of the transmission gear 61. A recess 61A that is open to the front is formed in the center of the front surface of the transmission gear 61. The transmission gear 61 is housed within the housing 20 above the front end of the drive shaft 51 of the motor 50, and the rear part of the transmission gear 61 is rotatably supported by a gear bearing 62 held by the spacer 26. A gear portion 61B is formed on the outer periphery of the front part of the transmission gear 61, and the gear portion 61B meshes with the pinion gear 51A of the drive shaft 51.

The drive shaft 63 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction. The drive shaft 63 is housed within the lifter housing 22 and is arranged coaxially with the transmission gear 61, in front of the transmission gear 61. The rear end of the drive shaft 63 is fitted into the recess 61A of the transmission gear 61 so as to be rotatable together with it, and the rear end portion of the drive shaft 63 is rotatably supported by a shaft bearing 64 held in the lifter housing 22. As a result, when the motor 50 is driven, the drive shaft 63 rotates. A male thread 63A is formed on the outer periphery of the drive shaft 63, except for the rear end.

The lifter 65 is formed in a generally elongated shape extending in the front-to-rear direction as a whole. The lifter 65 is composed of a lifter main body 66 and a lifter connecting portion 67 that forms the rear end of the lifter 65. The lifter connecting portion 67 is formed in a generally stepped cylindrical shape with its axial direction extending in the front-to-rear direction. A female thread 67A is formed on the inner periphery of the rear portion of the lifter connecting portion 67. The front portion of the drive shaft 63 is inserted into the lifter connecting portion 67, and the male thread 63A of the drive shaft 63 and the female thread 67A of the lifter connecting portion 67 are threadedly engaged. In other words, the drive shaft 63 and the lifter 65 are threadedly engaged.

As a result, when the drive shaft 63 rotates, the lifter 65 moves forward and backward (in the axial direction of the drive shaft 63). Specifically, the lifter 65 moves back and forth between the initial position (the position shown in Figure 2) and the reversal position (the position shown in Figure 5). Note that the rotation of the lifter 65 when the drive shaft 63 rotates is limited by a guide mechanism 80, which will be described later. The reversal position may also be referred to as the terminal position.

A detection target portion 67B is formed on the outer periphery of the rear end of the lifter connecting portion 67. The detection target portion 67B protrudes radially outward from the lifter main body 66 and is formed in a generally cylindrical shape with its thickness extending in the front-to-rear direction.

The lifter body 66 is formed in a generally bottomed cylindrical shape that is open to the rear. The rear end of the lifter body 66 is fitted into the front part of the lifter connecting part 67, connecting the lifter connecting part 67 and the lifter body 66 so that they cannot move relative to each other. When the lifter 65 is in its initial position, the front part of the drive shaft 63 is inserted into the interior of the lifter body 66 so that it can move relative to the lifter body 66. The front end of the lifter body 66 is inserted into the inner guide 45 of the support mechanism 40 described above, and is supported by the inner guide 45 so that it can move relative to the front and rear directions.

A lifter flange 66A is formed on the outer periphery of the rear end portion of the lifter body 66. The lifter flange 66A is formed in a disk shape that protrudes radially outward from the lifter body 66. When the lifter 65 is in the inverted position, the lifter flange 66A is positioned adjacent to the rear side of the inner guide 45. When the lifter body 66 and the lifter connecting portion 67 are connected, the front end of the lifter connecting portion 67 is positioned adjacent to the rear side of the lifter flange 66A of the lifter body 66.

The lifter detection switch 68 is configured as a lever-type microswitch and is located outside the lifter housing 22 (below the rear end). The lifter detection switch 68 is housed in a switch cover 69 (third housing) supported (fixed) on the lifter housing 22 and is held by the switch cover 69. In this way, to detect the position of the lifter 65 housed in a housing section (lifter housing 22) different from the housing 20 that houses the control section 100, the lifter detection switch 68 is housed in a housing area (switch cover 69) different from the main housing 24 that houses the control section 100 and the lifter housing 22 that houses the lifter 65. The switch cover 69 is a position detection section housing that houses the lifter detection switch 68 (position detection section). The lifter detection switch 68 is supported in a space surrounded by the outer wall of the main housing 24, the outer wall of the lifter housing 22, and the inner wall of the switch cover 69. The switch cover 69 may be configured to be supported by the main body housing 24, or may be configured to be connected to and supported by both the lifter housing 22 and the main body housing 24.

A spherical ball 70 is provided above the lifter detection switch 68. The ball 70 is disposed in a ball hole 22A formed in the lower outer periphery of the lifter housing 22. The ball hole 22A extends vertically, with the diameter of the ball hole 22A increasing downward. When the lifter detection switch 68 is in the OFF state, the outer periphery of the ball 70 abuts against the lever portion of the lifter detection switch 68 and the inner periphery of the ball hole 22A (see Figure 5). In this state, a portion of the outer periphery of the ball 70 protrudes radially inward relative to the inner periphery of the lifter housing 22 so that it is disposed within the lifter housing 22. The ball 70 is a transmission member that transmits the operation of the lifter 65 to the lifter detection switch 68. The ball hole 22A is a communication hole that connects the interior of the lifter housing 22 with the interior of the switch cover 69.

When the lifter 65 is positioned in its initial position, the outer periphery of the detection target portion 67B of the lifter 65 presses the ball 70 radially outward (downward), displacing the ball 70 toward the lifter detection switch 68 (downward). That is, when the lifter 65 reaches the initial position while moving in the return direction from the reverse position to the initial position, the ball 70 presses the lever portion of the lifter detection switch 68, switching the lifter detection switch 68 from OFF to ON. The lifter detection switch 68 is also electrically connected to the control unit 100 and outputs a detection signal to the control unit 100. That is, the lifter detection switch 68 is configured to transmit an ON signal to the control unit 100 when pressed by the ball 70.

(Regarding blade 72)
As shown in FIGS. 1, 2, 3B, and 4A, the blade 72 is formed in a plate shape with its thickness extending in the left-right direction. That is, the blade 72 has a plate shape extending in the front-rear and up-down directions. The rear end of the blade 72 is fixed to the front end of the lifter 65. Specifically, a step 66C (see FIG. 4A) is formed at the front end of the lifter body 66, and a pin P disposed in the step 66C engages the middle portion of the rear end of the blade 72 in the up-down direction. This allows the blade 72 to move integrally with the lifter 65 between an initial position and a reverse position. When the blade 72 is fixed to the lifter 65, the blade 72 is positioned so as to overlap the center lines of the lifter 65 and the drive shaft 63 when viewed from the front.

The front end of the blade 72 is configured as a cutting edge 72A for cutting the workpiece W. The cutting edge 72A is configured as a single-edged blade and is formed in a roughly V-shape that protrudes forward when viewed from the left and right.

When the blade 72 is in its initial position, it is positioned in front of the lifter housing 22 and behind the workpiece W. As the blade 72 moves forward from its initial position, it cuts the workpiece W. When the blade 72 is in its reverse position, it is set so that cutting the workpiece W is completed.

(Regarding the guide mechanism 80)
As shown in Figures 1, 2, 3(B), and 4 to 6, the guide mechanism 80 (adjustment mechanism) includes the inner guide 45 of the support mechanism 40, a pair of guide plates 81 as guide members, a connecting member 82, and a pair of head plates 83 as head portions. The head plates 83 are members that cover the blade 72 from the left and right when it is in the inverted position and function as members (support portions) that support the workpiece W. Note that the workpiece W may be fixed to a specific location (such as a wall or ceiling). In the present invention, the state in which the head plate 83 engages with the workpiece W in such a fixed state is also considered to be a state in which the workpiece W is supported by the head plate 83. The guide mechanism 80 is also connected to the housing 20.

The guide plate 81 is formed in a generally rectangular plate shape with its thickness extending in the left-right direction. A curved portion 81A (see FIG. 3B) is formed in the vertically middle portion of the guide plate 81. When viewed from the front, the curved portion 81A is formed in a generally arc-like shape that convexes outward in the left-right direction, corresponding to the outer shape of the inner guide 45. The curved portion 81A is positioned radially outward from the inner guide 45 and is fastened to the inner guide 45 by a pair of front and rear bolts BL3. This connects the guide plate 81 to the inner guide 45 so that it can rotate integrally with it. In other words, the guide mechanism 80 is connected to the housing 20 so that it can rotate with the front-to-rear direction as its axial direction. In other words, the inner guide 45 serves as the rotation axis of the guide mechanism 80 and also serves as a bearing member for the lifter 65.

The portion of the guide plate 81 above the curved portion 81A is configured as a guide portion 81B, and the portion of the guide plate 81 below the curved portion 81A is configured as a connecting portion 81C. The guide portions 81B of the pair of guide plates 81 are arranged opposite each other with a predetermined gap in the left-right direction, and the connecting portions 81C of the pair of guide plates 81 are arranged opposite each other with a predetermined gap in the left-right direction. The opposing distance between the pair of guide portions 81B is set shorter than the opposing distance between the pair of connecting portions 81C and is set slightly longer than the thickness of the blade 72. A recess 81D (see Figure 2) is formed at the corner of the rear end of the connecting portion 81C, and the recess 81D is cut out in a concave shape that is open to the rear and downward in side view.

The blade 72 is positioned between a pair of guide plates 81. Furthermore, the holding mechanism 90 (described later) limits the relative rotation of the guide plate 81 (guide mechanism 80) with respect to the housing 20. As a result, when the drive shaft 63 rotates, the guide portion 81B of the guide plate 81 limits the rotation of the lifter 65 and blade 72 with the drive shaft 63, allowing the blade 72 to reciprocate back and forth along the guide portion 81B. A slight gap (space) is provided between the guide portion 81B and the blade 72, allowing the blade 72 to rotate through this gap, but this gap is so small that it does not affect the cutting operation. In particular, the spacing of the guide portions 81B is sized to prevent the blade 72 from slipping out of the area (left-right spacing) between the pair of head plates 83. In other words, the spacing of the guide portions 81B is set large enough so that the blade 72 does not come into contact with the head plate 83 as it approaches the reversal position. More specifically, the distance (left-right gap) between the pair of guide portions 81B is configured to be smaller than the distance (left-right gap) between the pair of head plates 83. Furthermore, the holding mechanism 90 (described below) is configured to allow relative rotation of the guide plate 81 with respect to the housing 20 when a rotational force (operating force) equal to or greater than a predetermined value is applied to the guide plate 81 (guide mechanism 80) by manual operation by the operator. This changes the orientation of the blade 72 as viewed from the front. Specifically, it changes the orientation of the cutting edge 72A of the blade 72 as viewed from the front. In other words, the guide mechanism 80 is also configured as a mechanism that, when activated, changes the orientation of the blade 72 relative to the workpiece W as viewed in the direction of movement of the blade 72.

In this embodiment, the orientation of the blade 72 relative to the workpiece W can be determined in two directions by a stopper 94, which will be described later. More specifically, the stopper 94 allows the blade 72 to be determined in two directions: the orientation of the blade 72 when the guide mechanism 80 is positioned in a first position (the position shown in Figures 1 and 2), and the orientation of the blade 72 when the guide mechanism 80 is positioned in a second position (the position shown in Figure 6), which is rotated 180 degrees from the first position.

The connecting member 82 is formed as a generally elongated plate with its thickness extending in the left-right direction and its length extending in the front-to-rear direction. The connecting member 82 is positioned between the connecting portions 81C of the pair of guide plates 81 and is fastened to the guide plates 81 by bolts BL4.

The head plate 83 is formed in a plate shape with its thickness extending in the left-right direction. The head plate 83 is positioned in front of the guide plate 81 and laterally outboard of the connecting member 82. The lower end of the head plate 83 is fastened to the front end of the connecting member 82 with bolts BL4. The head plate 83 functions as a support for the workpiece W, and its features tailored to the shape of the workpiece W improve workability. In this embodiment, the rear end of the head plate 83 is formed with multiple (four in this embodiment) head recesses 83A (cutouts) as recesses. The head recesses 83A are formed in a concave shape that opens to the rear and penetrates in the left-right direction. This configuration enables the cutting of workpieces W with U-shaped cross sections. That is, when cutting the workpiece W, both ends of the workpiece W, as viewed from the longitudinal direction of the workpiece W, are inserted into the head recesses 83A to set (support) the workpiece W. In this way, the workpiece W is supported by the head plate 83 with a portion of it positioned in the head recess 83A. In this embodiment, head recesses 83A are provided in four locations, making it possible to cut workpiece W to widths corresponding to the combination of recesses. The shape of the head recess 83A can be modified as appropriate to suit the shape of the workpiece. The head recess 83A is an example of a cutout portion in the support portion or an open portion in the support portion of the present invention.

(Regarding the holding mechanism 90)
As shown in FIGS. 1 to 6 , the holding mechanism 90 includes a wave washer 92 as a movement limiting member and a pair of stoppers 94. As shown in FIG. 6 , the wave washer 92 is formed in a generally circular plate shape with its thickness extending in the front-to-rear direction. The wave washer 92 is disposed between the curved portion 81A of the guide plate 81 and the lifter housing 22, and is configured to limit rotation of the guide plate 81 by frictional forces generated between the wave washer 92, the guide plate 81, and the lifter housing 22. More specifically, when the drive shaft 63 rotates due to the driving of the motor 50, the lifter 65 and the blade 72 tend to rotate together with the drive shaft 63, resulting in a rotational force being input from the blade 72 to the guide plate 81. However, the shape of the wave washer 92 is designed to prevent the guide plate 81 from rotating at this time. On the other hand, when a rotational force (operational force) equal to or greater than a predetermined value is input to the guide plate 81 by manual operation by an operator, the guide plate 81 is permitted to rotate. That is, the wave washer 92 is configured to function as a so-called torque limiter member.

As shown in Figures 1 to 6, the stopper 94 is configured as a member that determines the rotational position of the guide plate 81 and thereby determines the orientation of the blade 72 relative to the workpiece W. Specifically, when the guide mechanism 80 is manually rotated (activated), the guide plate 81 abuts against the stopper 94, preventing the guide plate 81 from rotating, thereby determining the orientation of the blade 72 relative to the workpiece W.

The stopper 94 includes a fixed portion 94A that is fixed to the housing 20 and a contact portion 94B that is configured to be able to contact the guide plate 81. The fixed portion 94A is formed in the shape of a roughly rectangular plate with its thickness extending in the left-right direction. The fixed portions 94A are respectively located on the right side of the upper and lower flange portions 23A of the lifter housing 22 and are fastened together to the lifter housing 22 by bolts BL1.

The abutment portion 94B is formed in a generally rectangular column shape extending in the left-right direction. The abutment portion 94B is located on the front side of the lifter housing 22, and the right end of the abutment portion 94B is connected to the outer end of the fixed portion 94A in the up-down direction. As shown in FIGS. 1 and 3(B), when the guide mechanism 80 is in the first position, the upper abutment portion 94B abuts against the rear end of the guide portion 81B of the guide plate 81 from the right side, restricting counterclockwise rotation of the guide mechanism 80 as viewed from the front. When the guide mechanism 80 is in the first position, the left end of the lower abutment portion 94B is located within the recess 81D of the guide plate 81, preventing interference between the guide plate 81 and the lower stopper 94.

Furthermore, when the guide mechanism 80 is rotated 180 degrees clockwise from the first position as viewed from the front, the rear end of the guide portion 81B of the guide plate 81 abuts against the lower abutment portion 94B, restricting clockwise rotation of the guide mechanism 80 and positioning the guide mechanism 80 at the second position (see Figure 6). When the guide mechanism 80 is in the second position, the left end of the upper abutment portion 94B is positioned within the recess 81D of the guide plate 81, preventing interference between the guide plate 81 and the upper stopper 94. In this way, the pair of stoppers 94 also function as components that determine the operational rotation angle range of the guide mechanism 80. In other words, the pair of stoppers 94 determine the relative rotation angle range of the lifter 65 with respect to the drive shaft 63 when the guide mechanism 80 is in operation, thereby limiting excessive movement of the lifter 65 relative to the drive shaft 63. In this embodiment, the pair of stoppers 94 sets the operational rotation angle range of the guide mechanism 80 to 180 degrees. In other words, the operational range of the guide mechanism 80 is set to one rotation or less.

(Regarding the control unit 100)
As shown in FIG. 2 , the control unit 100 is accommodated within the lower end of the main body housing 24 and is held by the main body housing 24. The trigger switch 31, the motor 50, and the lifter detection switch 68 are electrically connected to the control unit 100. The control unit 100 detects the initial position of the lifter 65 based on a detection signal from the lifter detection switch 68. The control unit 100 also controls the drive of the motor 50 based on output signals from the trigger switch 31 and the lifter detection switch 68. When the control unit 100 drives the motor 50 in the forward direction, the lifter 65 (blade 72) moves forward, and when the control unit 100 drives the motor 50 in the reverse direction, the lifter 65 (blade 72) moves backward.

Furthermore, when the trigger 30 is released and the trigger switch 31 switches from ON to OFF while the motor 50 is rotating forward, the control unit 100 drives the motor 50 in the reverse direction. Furthermore, the control unit 100 has a rotation speed measurement unit 100A that measures the rotation speed of the drive shaft 51 of the motor 50. The rotation speed measurement unit 100A is a circuit board with multiple Hall ICs and is capable of detecting the magnetism of the permanent magnet provided in the rotor 52. The control unit 100 is configured to detect the rotation position and rotation speed of the rotor 52 (motor 50) based on a signal from the rotation speed measurement unit 100A. Because the rotation speed measurement unit 100A must be located near the rotor 52, it is located at a distance from the control unit 100 by connecting it via a signal line. The signal from the rotation speed measurement unit 100A allows the control unit 100 to detect the number of rotations the motor 50 has made from its initial position. As a result, the control unit 100 detects the reverse position of the lifter 65 (blade 72) based on the number of rotations of the motor 50, starting from the initial position of the lifter 65. Furthermore, when the control unit 100 detects the reverse position of the lifter 65 (blade 72), it switches the motor 50 from forward rotation to reverse rotation. In this way, the rotation speed measurement unit 100A functions as part of the position detection unit. More specifically, the rotation speed measurement unit 100A functions as a reverse position detection unit that detects when the lifter 65 is positioned at the reverse position. In this way, the position detection unit of the present invention includes the lifter detection switch 68 and the rotation speed measurement unit 100A. Note that the lifter detection switch 68 directly detects the initial position of the lifter 65, and the rotation speed measurement unit 100A indirectly detects the reverse position of the lifter 65. Note that the timing at which the control unit 100 starts measuring the number of rotations of the motor 50 will be described later.

(Action and effect)
Next, the operation of the electric cutting machine 10 will be described, and the effects of the electric cutting machine 10 of this embodiment will be described.

Figure 7 shows a flowchart of the electric cutter 10. As shown in this figure, in the operation of the electric cutter 10, in step 1 (S1), the control unit 100 detects whether the trigger switch 31 is on or not based on the output signal from the trigger switch 31. In other words, the control unit 100 determines whether the trigger 30 has been operated or not. In step 1, if the trigger switch 31 is not on (No in step 1), the process returns to step 1. In step 1, if the trigger switch 31 is on (Yes in step 1), the process proceeds to step 2 (S2).

In step 2, the control unit 100 detects whether the lifter detection switch 68 is turned on based on the output signal from the lifter detection switch 68. In other words, the control unit 100 determines whether the lifter 65 is placed in the initial position. In step 2, if the lifter detection switch 68 is turned on (Yes in step 2), the process proceeds to step 3 (S3).

In step 3, the control unit 100 drives the motor 50 in the forward direction. That is, when the control unit 100 detects the operation of the trigger 30 and the initial position of the lifter 65, it drives the motor 50 in the forward direction. This causes the lifter 65 and blade 72 to move forward (toward the outward path). That is, the lifter 65 and blade 72 approach the workpiece. After processing step 3, the process proceeds to step 4 (S4).

In step 4, the control unit 100 detects whether the trigger switch 31 continues to be on based on the output signal from the trigger switch 31. In other words, the control unit 100 determines whether the trigger 30 is being operated. In step 4, if the trigger switch 31 continues to be on (Yes in step 4), the process proceeds to step 5 (S5).

In step 5, the control unit 100 detects whether the lifter detection switch 68 has switched from ON to OFF based on the output signal from the lifter detection switch 68. If the lifter detection switch 68 has switched OFF in step 5 (Yes in step 5), the process proceeds to step 6 (S6). That is, in this embodiment, the position of the lifter 65 at which the lifter detection switch 68 has switched from ON to OFF is set as the starting point of the initial position of the lifter 65 moving forward (hereinafter, this position of the lifter 65 is referred to as the initial starting point position), and in step 5, the control unit 100 detects the initial starting point position of the lifter 65. On the other hand, if the lifter detection switch 68 has not switched OFF in step 5 (No in step 5), the process returns to step 4. That is, if the lifter 65 moving forward from its initial position has not reached the initial starting point position, the process returns to step 4.

In step 6, the control unit 100 begins measuring the number of rotations of the motor 50. Specifically, the control unit 100 begins measuring (counting) the number of rotations of the motor 50 based on a signal from the rotation number measurement unit 100A. After processing step 6, the process proceeds to step 7 (S7).

In step 7, the control unit 100 detects whether the trigger switch 31 continues to be in the on state based on the output signal from the trigger switch 31. In other words, the control unit 100 determines whether the trigger 30 is being operated. In step 7, if the trigger switch 31 continues to be in the on state (Yes in step 7), the process proceeds to step 8 (S8).

In step 8, the control unit 100 determines whether the rotation speed of the motor 50 has reached or exceeded a predetermined rotation speed. In other words, the control unit 100 determines whether the lifter 65 has reached the reversal position. In step 8, if the rotation speed of the motor 50 is not greater than or equal to the predetermined rotation speed (No in step 8), the process returns to step 7. In step 8, if the rotation speed of the motor 50 is greater than or equal to the predetermined rotation speed (Yes in step 8), the process proceeds to step 9 (S9).

In step 9, the control unit 100 stops the forward rotation of the motor 50. After processing step 9, the process proceeds to step 10 (S10).

In step 10, the motor 50 is placed in a standby state. That is, after the forward rotation of the motor 50 is stopped, the control unit 100 does not control the drive of the motor 50, and the motor 50 is placed in a standby state. After processing step 10, the process proceeds to step 11 (S11). Specifically, the process proceeds to step 11 after a predetermined time has elapsed after the forward rotation of the motor 50 is stopped.

In step 11, the control unit 100 drives the motor 50 in the reverse direction. This causes the lifter 65 and blade 72 to move backward (toward the return path) and separate from the workpiece W. In other words, the lifter 65 and blade 72 reverse at the reversal position, and the return path movement of the lifter 65 and blade 72 begins. After processing step 11, the process proceeds to step 12 (S12).

In step 12, the control unit 100 detects whether the lifter detection switch 68 is turned on based on the output signal from the lifter detection switch 68. In other words, the control unit 100 determines whether the lifter 65 has reached its initial position. If the lifter detection switch 68 is not turned on in step 12 (No in step 12), the process returns to step 12. On the other hand, if the lifter detection switch 68 is turned on in step 12 (Yes in step 12), the process proceeds to step 13 (S3).

In step 13, the control unit 100 stops driving the motor 50 in the reverse direction. This stops the lifter 65 in its initial position. After processing step 13, the process proceeds to step 14 (S14). Note that stopping the reverse drive of the motor 50 returns the lifter 65 to its initial position; however, depending on the braking time of the motor 50, the lifter 65 may stop at a position that overruns the initial starting position toward the return path (hereinafter, this position of the lifter 65 is referred to as the initial stop position).

In step 14, the control unit 100 detects whether the trigger switch 31 has switched from on to off based on the output signal from the trigger switch 31. In other words, the control unit 100 detects whether the operation of the trigger 30 has been released. If the trigger switch 31 is not off in step 14 (No in step 14), the process returns to step 14. On the other hand, if the trigger switch 31 is off in step 14 (Yes in step 14), the operation of the trigger 30 has been released, and the operation of the electric cutter 10 is terminated.

In step 2, if the lifter detection switch 68 is not on (No in step 2), the process proceeds to step 11. In other words, in this case, the lifter 65 has not returned to its initial position when the electric cutter 10 starts operating, so the process proceeds to step 11 and the lifter 65 is returned to its initial position.

Furthermore, in steps 4 and 7, if the trigger switch 31 does not remain on (No in steps 4 and 7), the process proceeds to step 9. In other words, in this case, the operator's operation on the trigger 30 has been released while the lifter 65 was moving forward. Therefore, the control unit 100 stops the forward rotation of the motor 50, and after a predetermined time has elapsed, drives the motor 50 in the reverse direction to return the lifter 65 to its initial position.

The operation of the electric cutter 10 described above will be explained using the time chart shown in Figure 8. As shown in this figure, at time T0, when the electric cutter 10 is in an inoperative state, the lifter 65 is positioned in its initial stop position. Therefore, at time T0, the lifter detection switch 68 is on. Also, because the electric cutter 10 is in an inoperative state at time T0, the trigger switch 31 is off.

Then, at time T1, when the trigger switch 31 is turned on, the control unit 100 starts driving the motor 50 in the forward direction, and the output of the motor 50 gradually increases from zero, while the rotation speed of the motor 50 gradually increases from zero. As a result, the lifter 65 moves from the initial stop position toward the forward path.

At time T2, the lifter 65 reaches the initial starting position, and the lifter detection switch 68 switches from on to off. As a result, at time T2, the control unit 100 begins measuring the number of rotations of the motor 50. In other words, the control unit 100 begins counting the number of rotations of the motor 50.

At time T3, the lifter 65 reaches the reversal position and the rotation count of the motor 50 reaches a predetermined number. This causes the control unit 100 to stop driving the motor 50 in the forward direction. In other words, the power supplied to the motor 50 becomes zero, and the rotation speed of the motor 50 gradually decreases. Also, at time T3, the rotation count of the motor 50 reaches a predetermined number, so the control unit 100 resets the rotation count to zero.

At time T4, the rotational speed of the motor 50 becomes zero. Then, at time T5, the control unit 100 starts driving the motor 50 in the reverse direction, and as the output of the motor 50 gradually increases from zero, the rotational speed of the motor 50 gradually increases from zero. This causes the lifter 65 to move from the reverse position toward the return path. In other words, the time from time T3 to time T5 is the standby time during which the motor 50 is placed in a standby state.

At time T6, the lifter 65 reaches the initial starting position, and the lifter detection switch 68 switches from OFF to ON. This stops the reverse drive of the motor 50 by the control unit 100. In other words, the output of the motor 50 becomes zero, and the rotation speed of the motor 50 gradually decreases.

Then, at time T7, the rotational speed of the motor 50 becomes zero and the lifter 65 reaches its initial stop position.

The above time chart shows an example in which the operator's operation of the trigger 30 is released between times T5 and T6. In other words, the operation of the trigger 30 is released while the lifter 65 is moving backward. As a result, the control unit 100 continues to drive the motor 50 in the reverse direction, and the lifter 65 returns to its initial position.

As described above, according to the electric cutter 10 of this embodiment, the feed screw mechanism 60 has a lifter detection switch 68 that detects the initial position of the lifter 65. The control unit 100 then detects the initial position of the lifter 65 based on the detection signal of the lifter detection switch 68. As a result, when the lifter 65 is in its initial position, the control unit 100 drives the motor 50 in the forward direction, thereby moving the lifter 65 forward from the initial position to the reverse position. The control unit 100 also detects the reverse position of the lifter 65 based on the rotation speed of the motor 50. As a result, the motor 50 can be stopped at the reverse position of the lifter 65, thereby ending the cutting process of the workpiece W with the blade 72. The control unit 100 then drives the motor 50 in the reverse direction, thereby moving the lifter 65 backward from the reverse position to the initial position, and stopping the motor 50 at the initial position.

As described above, with the electric cutter 10 of this embodiment, the control unit 100 can detect the initial position and the reverse position based on the detection signal from the lifter detection switch 68 and the rotation speed of the motor 50. That is, the control unit 100 can drive and control the motor 50 to stop the movement of the lifter 65 and the blade 72 at the initial position and the reverse position. That is, while driving the motor 50 to move the blade 72, the control unit 100 can stop the motor 50 when a portion of the blade 72 overlaps with the head plate 83 when viewed from the left-right direction or the up-down direction perpendicular to the front-to-back direction, even if the trigger 30 is kept in the on state (pulled state). Furthermore, while driving the motor 50 to move the blade 72, the control unit 100 can stop the motor 50 so that the drive shaft 63 and the lifter 65 do not become unthreaded. In other words, the motor 50 can be stopped while maintaining the threaded state between the drive shaft 63 and the lifter 65. This allows the lifter 65 to be stopped or reversed at the reverse position without requiring a switching mechanism for disconnecting or connecting the transmission path of the motor's driving force to the lifter, as in the electric cutter described in the background art. In other words, the control unit 100 is configured to stop the motor 50 even if the trigger 30 is maintained in the ON state when a portion of the blade 72 overlaps the head plate 83 in a left-right view, i.e., when the blade 72 has cut the workpiece W, even if the trigger 30 is maintained in the ON state. Therefore, the lifter 65 and the blade 72 can be moved suitably. In particular, the control unit 100 is configured to stop the motor 50 even if the trigger 30 is maintained in the ON state (pulled state) when the head recess 83A overlaps the blade 72 in a left-right view. This allows the cutting operation to be performed suitably even when a portion of the workpiece W is positioned in the head recess 83A. When the blade 72 is positioned at the reverse position, the motor 50 may be maintained in the stopped state or may be immediately reversed without being stopped. Furthermore, because workpieces vary in shape, from thin to complex, the timing for stopping the motor 50 can be adjusted as needed, as long as a portion of the blade 72 overlaps the head plate 83 when viewed from the left to right. Specifically, when cutting thin materials, the motor 50 can be stopped or reversed earlier. When cutting complex-shaped workpieces W using the head recess 83A, the motor 50 can be stopped or reversed when the blade 72 overlaps the head recess 83A. Furthermore, the motor 50 automatically stops when the lifter 65 reaches the reverse position, allowing the operator to recognize when processing is complete. This improves workability. Furthermore, by providing a female thread 67A on the reciprocating lifter 65 and a male thread 63A on the drive shaft 63, the lifter 65 can be configured to operate outside the drive shaft 63. This makes it easier to detect the position of the lifter 65 compared to a configuration in which the drive shaft 63 operates inside the lifter 65.

Furthermore, the lifter detection switch 68 is configured to switch from OFF to ON when the lifter 65 reaches the initial position during its return movement from the reverse position to the initial position. Furthermore, the control unit 100 begins measuring the number of rotations of the motor 50 from the point at which the lifter detection switch 68 switches from ON to OFF. In other words, the control unit 100 begins measuring the number of rotations of the motor 50 from the initial starting position of the lifter 65. This allows the reverse position of the lifter 65 to be detected with high accuracy.

In other words, as described above, when the lifter 65 returns to its initial position, the control unit 100 stops driving the motor 50 based on the detection signal from the lifter detection switch 68 switching from off to on. At this time, the lifter 65 stops at an initial stop position, which is an overrun toward the return path from the initial start position. This initial stop position varies depending on the braking performance of the motor 50, etc. For this reason, if measurement of the motor 50 rotation speed is started using the initial stop position of the lifter 65 as a starting point, it may not be possible to accurately detect the reversal position of the lifter 65.

In contrast, in this embodiment, as described above, the control unit 100 starts measuring the rotation speed of the motor 50 from the point at which the lifter detection switch 68 switches from on to off. Because the point at which the lifter detection switch 68 switches from on to off is constant, by starting measurement of the rotation speed of the motor 50 from the initial starting position of the lifter 65, the reversal position of the lifter 65 can be detected with high accuracy.

In particular, in the electric cutter 10 of this embodiment, when the guide mechanism 80 is activated to change the orientation of the blade 72, the lifter 65 rotates relative to the drive shaft 63. That is, at this time, the lifter 65 moves forward and backward relative to the drive shaft 63. As a result, the initial stop position of the lifter 65 differs before and after the guide mechanism 80 is activated. Therefore, in an electric cutter 10 having a guide mechanism 80 for changing the orientation of the blade 72, the reversal position of the lifter 65 can be accurately detected by starting measurement of the motor 50 rotation speed from the initial starting position of the lifter 65.

In addition, when the control unit 100 detects the reversal position of the lifter 65, after a predetermined time has elapsed, it drives the motor 50 in the reverse direction to move the lifter 65 back toward the return path. This allows the operator to know that the blade 72 has reached the reversal position and that cutting of the workpiece W by the blade 72 has ended.

Furthermore, if the control unit 100 does not detect the initial position of the lifter 65 when the trigger 30 is first operated, the control unit 100 drives the motor 50 in the reverse direction to move the lifter 65 in the return direction. This automatically returns the blade 72 to its initial position, allowing the user to continue working on the electric cutter 10.

Furthermore, when the trigger 30 is released while the lifter 65 is moving in the forward direction from the initial position to the reverse position, the control unit 100 drives the motor 50 in the reverse direction to move the lifter 65 in the backward direction. This allows the blade 72 to automatically return to the initial position when cutting the workpiece W is stopped or interrupted.

The electric cutter 10 also has a guide mechanism 80 that guides the forward/backward movement of the blade 72, restricting the blade 72 from rotating around its axis in the forward/backward direction (the direction of movement of the lifter 65). In the electric cutter 10, rotational force is transmitted by the threaded engagement between the drive shaft 63 and the lifter 65. Therefore, when the motor 50 is rotating, rotational force is also transmitted to the lifter 65 around its axis in the forward/backward direction. However, the guide mechanism 80 prevents the blade 72 (lifter 65) from rotating. In particular, the guide mechanism 80 (guide portion 81B) also functions as a cover for the blade 72, restricting the rotation of the blade 72 with the cover member for the blade 72. Furthermore, the guide portion 81B guides (restricts rotation of) the blade 72 at a position spaced apart vertically (radially) from the lifter 65, thereby reducing the force transmitted from the rotating blade 72 to the guide portion 81B. The operation of the guide mechanism 80 changes the orientation of the blade 72 when viewed from the forward/backward direction. Specifically, the operator manually rotates the guide plate 81 of the guide mechanism 80 around the axis of the inner guide 45, thereby changing the orientation of the blade 72 as viewed from the front-to-rear direction. This allows the orientation of the blade 72 relative to the workpiece W, which is positioned in front of the blade 72, to be changed. This allows the orientation of the blade 72 relative to the workpiece W to be changed without changing the orientation of the entire electric cutter 10 relative to the workpiece W. In particular, because the cutting edge 72A of the blade 72 is single-edged, the finished surface of the workpiece W can be easily changed by operating the guide mechanism 80. This improves the operability of the electric cutter 10.

In the feed screw mechanism 60, a lifter 65 is threadedly engaged with a drive shaft 63 whose axial direction is the front-to-rear direction, and the blade 72 is fixed to the lifter 65. Furthermore, the guide mechanism 80 has a guide plate 81 that guides the movement of the blade 72 in the front-to-rear direction, and the guide plate 81 is rotatably connected to the lifter housing 22 with the axial direction also being the front-to-rear direction. When the guide mechanism 80 is activated, it rotates around the axis of the drive shaft 63. As a result, the guide plate 81 can rotate the lifter 65 and blade 72 around the axis of the drive shaft 63, changing the orientation of the blade 72.

The guide mechanism 80 is composed of a pair of guide plates 81 and an inner guide 45 that rotatably connects the guide plates 81 to the lifter housing 22. The inner guide 45 is formed in a cylindrical shape with its axial direction extending in the front-to-rear direction, and supports the lifter 65 so that it can move in the front-to-rear direction. This allows the inner guide 45, which is the rotation axis of the guide plates 81, to be used to movably support the lifter 65. This prevents an increase in the number of parts in the electric cutter 10 and contributes to a more compact electric cutter 10.

The lifter housing 22 is also provided with a pair of stoppers 94, and the position of the guide mechanism 80 is determined when the guide plate 81 abuts against the abutment portions 94B of the stoppers 94. This determines the orientation of the blade 72 relative to the workpiece W. Specifically, in this embodiment, the orientation of the blade 72 when the guide mechanism 80 is positioned in the first position is offset by 180 degrees in the rotational direction of the guide mechanism 80 from the orientation of the blade 72 when the guide mechanism 80 is positioned in the second position. This allows the operator to easily determine the position of the guide mechanism 80 and change the orientation of the blade 72.

The operating range of the guide mechanism 80 is also defined by a pair of stoppers 94. Specifically, the rotation angle range of the guide mechanism 80 is defined to 180 degrees by the pair of stoppers 94. This prevents the initial stopping position of the lifter 65 from shifting excessively before and after the guide mechanism 80 is operated.

A wave washer 92 is provided between the lifter housing 22 and the guide plate 81. The wave washer 92 limits the relative rotation of the guide mechanism 80 with respect to the housing 20 when the motor 50 is driven. Furthermore, when an operating force (rotational force) equal to or greater than a predetermined value is applied to the guide mechanism 80 (guide plate 81) by the operator, the guide mechanism 80 is permitted to rotate relative to the housing 20. This allows for a simple configuration that limits the relative rotation of the guide mechanism 80 with respect to the housing 20 when the motor 50 is driven, while also permitting the operator to manually operate the guide mechanism 80.

In this embodiment, the control unit 100 detects the reversal position of the lifter 65 by measuring the rotation speed of the motor 50, but the method for detecting the reversal position of the lifter 65 is not limited to this. For example, a reversal position detection switch (microswitch) configured similarly to the lifter detection switch 68 may be provided in the feed screw mechanism 60, and the reversal position of the lifter 65 may be directly detected by the reversal position detection switch, and the control unit 100 may detect the reversal position of the lifter 65 based on the detection signal from the reversal position detection switch. In this case, the lifter detection switch 68 corresponds to the initial position detection unit of the present invention, and the reversal position detection switch corresponds to the reversal position detection unit of the present invention.

Also, for example, in the feed screw mechanism 60, a contact or non-contact linear sensor may be provided instead of the lifter detection switch 68, and the position of the lifter 65 may be detected by the linear sensor. In this case, the initial position and reverse position of the lifter 65 can still be detected by the control unit 100. Alternatively, the load on the motor 50 may be configured to increase when the lifter 65 is in the initial position, and the initial position may be detected by detecting the increase in current under load. In this case, the timing when the load on the motor 50 is reduced during forward rotation (the timing when the current value drops) may be set as the initial position, and the reverse position may be detected as described above. In this way, the position detection unit in the present invention can be configured using a variety of means, not just mechanical or electronic switches.

In addition, in this embodiment, the transmission gear 61 meshes with the pinion gear 51A of the drive shaft 51 of the motor 50, and the drive shaft 63 is connected to the transmission gear 61 so that it can rotate integrally with the transmission gear 61. Alternatively, for example, the motor 50 may be changed to a stepping motor with a feed screw, and the lifter 65 may be threadedly fitted onto the feed screw. In this case, the accuracy of detecting the position of the lifter 65 by the control unit 100 can be further improved. Furthermore, since the transmission gear 61 can be omitted, this contributes to the miniaturization of the electric cutting machine 10.

In addition, in this embodiment, the rotation range of the guide mechanism 80 is restricted by a pair of stoppers 94, allowing the orientation of the blade 72 to be easily changed. In other words, by placing the guide mechanism 80 in a first position or a second position where it abuts the stoppers 94, the position of the guide mechanism 80 relative to the housing 20 is determined and the orientation of the blade 72 is changed. In other words, the guide mechanism 80 is positioned at two locations to change the orientation of the blade 72, but it may also be positioned at three locations. In other words, the guide mechanism 80 may be positioned at an intermediate position between the first and second positions so that it can be held in that intermediate position. This configuration will be described below using Figures 9 and 10.

As shown in Figures 9 and 10, in this configuration, instead of the wave washer 92, a fixed washer 110 is placed between the guide plate 81 and the lifter housing 22 (fixed plate 41) as a movement limiting member. The fixed washer 110 is formed in a roughly frame-like plate shape with its thickness extending in the front-to-rear direction. The fixed washer 110 has a pair of upper and lower fixed pieces 112 that extend in the left-to-right direction.

A pair of left and right engaging protrusions 114 are formed on the fixed piece 112, and the engaging protrusions 114 are bent into a roughly U-shape that protrudes forward and opens rearward. With the inner guide 45 (not shown in Figure 9) inserted through the fixed washer 110, the fixed washer 110 is positioned between the curved portion 81A of the guide plate 81 and the lifter housing 22. The pair of left and right engaging protrusions 114 also sandwich the guide portion 81B and connecting portion 81C of the guide plate 81 from the outside in the left-right direction. This allows the fixed washer 110 to be attached to the guide plate 81 so that it can rotate integrally with it.

A locking protrusion 116 is formed in the center of the fixed piece 112 in the left-right direction, and the locking protrusion 116 is bent in a roughly arc shape that protrudes to the rear and opens to the front.

On the other hand, a locking recess 41B is formed at the front end of the fixing plate 41, in front of the bolt BL2, as a locking portion. When viewed from the left and right, the locking recess 41B is formed in a roughly arc shape that is open to the front.

When the guide mechanism 80 is in the first or second position, the locking protrusion 116 is positioned 90 degrees away from the locking recess 41B in the rotational direction of the guide mechanism 80 (see Figure 9(A) for the second position of the guide mechanism 80). When the guide mechanism 80 is positioned intermediate between the first and second positions, the locking protrusion 116 fits into the locking recess 41B, and the locking protrusion 116 and the locking recess 41B engage in the rotational direction (see Figure 9(B)). This indirectly locks the locking protrusion 116 to the housing 20 via the fixed plate 41, effectively restricting rotation of the guide mechanism 80. At this time, the operator also feels a click. As described above, the guide mechanism 80 can be positioned at three locations to restrict rotation of the guide mechanism 80. In particular, as described above, the guide portion 81B, which is the contact point between the blade 72 and the guide mechanism 80, is located vertically (radially) further away from the lifter 65 (center of rotation). Therefore, when the blade 72 itself attempts to rotate, the rotation of the blade 72 is restrained with little force, and when an operator attempts to rotate the blade 72 via the guide mechanism 80, the blade 72 can be rotated with little force. Note that in the above example, the locking recess 41B is formed in the fixed plate 41, but the locking recess 41B may also be formed in the housing 20, and the locking protrusion 116 may be directly locked to the housing 20.

In addition, in this embodiment, when the guide mechanism 80 is in the first or second position, the guide plate 81 abuts against the abutment portion 94B of the stopper 94, restricting the rotation of the guide mechanism 80. However, a magnet may be embedded in the abutment portion 94B and the guide plate 81 may be made of steel plate, so that the magnetic force of the magnet maintains the abutment state between the guide plate 81 and the stopper 94. This allows the guide mechanism 80 to be held securely in the first or second position.

10 Electric cutting machine (work machine)
20 Housing 45 Inner guide (rotating shaft)
50 Motor 63 Drive shaft (output part, output shaft)
65 Lifter (moving member)
72 Blade (cutting tool)
80 Guide mechanism 81 Guide plate (guide member)
81B Guide portion 83 Head plate (head portion)
92 Wave washer (movement limiting member)
94 Stopper 110 Fix washer 116 Locking protrusion (locking portion)
W Work material

Claims (19)

A motor;
a housing that accommodates the motor;
an output section rotated by the motor;
a moving member that is threadably engaged with the output portion and moves as the output portion rotates;
a blade supported by the movable member and reciprocating between an initial position and an inverted position as the movable member moves;
a guide mechanism configured to sandwich the blade, supported by the housing so as to be rotatable about the movement direction of the movable member, and configured to restrict rotation of the blade about an axis defined by the movement direction of the movable member;
Equipped with
the guide mechanism and the moving member are capable of relative rotation about the moving direction of the moving member, and are each capable of rotation about the moving direction of the moving member relative to the housing,
the blade is configured to rotate together with the moving member around the moving direction of the moving member when the guide mechanism is rotated relative to the housing,
an outer surface of the blade and an inner surface of the guide mechanism can be separated from each other, and when the blade is operated by the motor, the blade comes into contact with the inner surface of the guide mechanism, thereby guiding the movement of the moving member in the movement direction while restricting the rotation of the blade about an axis in the movement direction of the moving member;
The work machine further comprises a stopper provided on the housing for restricting the rotation of the guide mechanism within a predetermined angular range when the guide mechanism is rotatable by an operator. The work machine described in claim 1, wherein the guide mechanism has a guide portion that can abut against the blade. The work machine described in claim 2, wherein the guide portion is located at a distance from the moving member in a direction perpendicular to the direction of movement of the moving member. A work machine as described in claim 2 or claim 3, wherein at least a portion of the blade positioned in the inverted position is configured to be able to abut against the guide mechanism. a head portion capable of supporting a workpiece to be cut by the blade;
The head portion is configured to sandwich the blade positioned at the inverted position,
The work machine according to any one of claims 2 to 4, wherein the guide portion regulates the rotation of the blade so that the blade does not come into contact with the head portion as it moves from the initial position toward the inverted position. A motor;
a housing that accommodates the motor;
a moving member that moves along a first direction by the driving force of the motor;
a tool bit connected to the moving member;
a guide mechanism connected to the housing, the guide mechanism including a guide portion that restricts rotation of the tool bit about an axis in the first direction and guides movement of the tool bit along the first direction, and an engaging portion that is engageable with a workpiece;
Equipped with
the guide mechanism and the moving member are configured to be capable of relative rotation about an axis in the first direction, and each of them is configured to be capable of rotation about an axis in the first direction relative to the housing,
When the guide mechanism is rotated relative to the housing, the tool bit is biased by the guide mechanism that rotates relative to the moving member, causing the moving member to rotate relative to the housing about an axis in the first direction,
A work machine in which the movable member is supported at an inner portion of a support portion provided on the housing so that it can move in a first direction and rotate around an axis defined by the first direction, and the guide mechanism is supported at an outer portion of the support portion so that it can rotate relative to the housing around an axis defined by the first direction. the guide mechanism is coupled to the housing so as to be rotatable about an axis in the first direction,
The work machine according to claim 6, wherein when the guide mechanism rotates, the guide mechanism rotates relative to the housing to change the orientation of the tool bit. The housing accommodates an output shaft connected to the motor, and the moving member is screw-engaged with the output shaft.
When the output shaft is rotated by the driving force of the motor, the moving member moves in the axial direction of the output shaft,
The work machine according to claim 7, wherein when the guide mechanism rotates about an axis in the first direction, the guide mechanism and the tool bit rotate about an axis in the first direction. the tip tool is a plate-shaped blade,
The guide mechanism includes:
a rotary shaft rotatably connected to the housing and arranged coaxially with the output shaft;
a pair of guide members connected to the rotary shaft so as to be rotatable together with the rotary shaft and sandwiching the tool bit therebetween to limit rotation of the tool bit around the axis of the output shaft;
The work machine according to claim 8, further comprising: The rotating shaft is formed in a cylindrical shape,
The work machine according to claim 9, wherein the moving member is movably supported on the rotary shaft. The work machine described in any one of claims 6 to 10, wherein the housing is provided with a stopper that defines the rotation range of the guide mechanism. A motor;
a housing that accommodates the motor;
a moving member that moves along a first direction by the driving force of the motor;
a tool bit connected to the moving member;
a guide mechanism including a guide portion that restricts rotation of the tool bit about an axis in the first direction and guides movement of the tool bit along the first direction, and an engaging portion that can engage with a workpiece, and the guide mechanism is rotatably connected to the housing;
Equipped with
a stopper that defines a rotation range of the guide mechanism is provided on the housing;
The stopper is provided with a magnet configured to be able to abut against the guide mechanism, and the abutting state between the guide mechanism and the stopper is maintained by the magnetic force of the magnet. a movement limiting member is provided between the housing and the guide mechanism,
The work machine described in claim 6 or claim 12, wherein the movement limiting member limits the relative rotation of the guide mechanism with respect to the housing around an axis in the first direction when the motor is driven, and allows the relative rotation of the guide mechanism with respect to the housing around an axis in the first direction when an operating force equal to or greater than a predetermined value is applied to the guide mechanism by an operator. The work machine described in claim 13, wherein the movement limiting member limits the relative rotation of the guide mechanism with respect to the housing when the motor is driven by the frictional force generated between the housing and the guide mechanism. the movement limiting member is provided so as to be movable integrally with the guide mechanism,
The movement limiting member is formed with a locking portion,
15. The work machine according to claim 13 or 14, wherein the locking portion is directly or indirectly locked to the housing at an intermediate position within the rotation range of the guide mechanism, thereby restricting relative rotation of the guide mechanism with respect to the housing. A motor;
a housing that accommodates the motor;
a screw portion that is rotated by the motor in a first rotation direction or a second rotation direction opposite to the first rotation direction, with the first direction as an axis;
a moving member that is threadedly engaged with the threaded portion, that moves in one direction in the first direction as the threaded portion rotates in the first rotational direction, and that moves in the other direction in the first direction as the threaded portion rotates in the second rotational direction, and is thereby driven to reciprocate along the first direction by the driving force of the motor;
a tool bit connected to the movable member and moving in the first direction integrally with the movable member ;
a guide portion that restricts the bit from rotating about an axis in the first direction when the rotational force of the motor is transmitted to the moving member and the moving member moves in the first direction, regardless of whether the threaded portion rotates in the first rotation direction or the second rotation direction;
Equipped with
A work machine configured such that even when the guide portion restricts the tip tool from rotating around the first direction as an axis and the motor can move the moving member via the screw portion , the tip tool can still rotate around the first direction as an axis when an operator applies a biasing force to the tip tool such that the tip tool rotates around the first direction as an axis. A motor;
a housing that accommodates the motor;
a moving member that moves along a first direction by the driving force of the motor;
a tool bit connected to the moving member;
a guide portion that restricts the rotation of the tool bit about an axis in the first direction when a rotational force of the motor is transmitted thereto;
an elastic member that suppresses relative rotation of the guide portion with respect to the housing about an axis in the first direction by using a biasing force;
Equipped with
The tool bit is configured to be able to rotate around the first direction as an axis when an operator applies a biasing force to the tool bit such that the tool bit rotates around the first direction as an axis, even when the tool bit is restricted from rotating around the first direction as an axis by the guide portion,
Even when the relative rotation of the guide portion with respect to the housing about the first direction as an axis is suppressed by the biasing force of the elastic member, the operator can directly bias the guide portion to rotate the guide portion relative to the housing about the first direction as an axis, and the work machine is configured to be able to perform work using the tool tip in this state. The work machine according to claim 16 or 17, wherein the guide portion guides the movement of the tool bit along the first direction. A motor;
a housing that accommodates the motor;
an output section rotated by the motor;
a moving member that is threadably engaged with the output portion and moves as the output portion rotates;
a blade supported by the movable member and reciprocating between an initial position and an inverted position as the movable member moves;
an adjustment mechanism having a pair of plate members sandwiching the blade and supported by the housing so as to be rotatable about the movement direction of the moving member;
Equipped with
By rotating the adjustment mechanism, a rotational position of the blade around the movement direction can be adjusted,
The working machine further comprises a stopper provided on the housing for restricting the rotation of the movable member within a predetermined angular range when the adjustment mechanism is rotatable by an operator.