WO2023017789A1

WO2023017789A1 - Work machine

Info

Publication number: WO2023017789A1
Application number: PCT/JP2022/030063
Authority: WO
Inventors: 哲也門前; 祐樹石川
Original assignee: 工機ホールディングス株式会社
Priority date: 2021-08-07
Filing date: 2022-08-05
Publication date: 2023-02-16
Also published as: JPWO2023017789A1

Abstract

This invention optimally reciprocates a cutting blade. In this motorized cutting machine 10, a control unit 100 detects an initial position and a reversing position on the basis of a detection signal from a lifter detection switch 68, and the rpms of the motor 50. Namely, the motor 50 is drive-controlled by means of the control unit 100 to allow the travel of a lifter 65 and a blade 72 to be halted in the initial position and the reversing position. As a result thereof, for example, without providing a switching mechanism or the like for switching between disconnected and connected states of the path transmitting the motor drive force to the lifter, the lifter 65 can be halted or reversed in the reversing position. Accordingly, the lifter 65 and the blade 72 can be made to travel optimally.

Description

work machine

The present invention relates to working machines.

The electric reciprocating tool (work machine) described in Patent Document 1 below includes 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. , is composed of When the motor is driven, the shuttle screw moves axially relative to the screw shaft, thereby reciprocating the movable blade back and forth. Thereby, the material to be cut placed in front of the movable blade can be cut.

JP-A-2001-277039

Here, in the electric reciprocating tool, when the movable blade moves to the foremost position, the screw engagement between the shuttle screw and the screw shaft is released, and power transmission to the shuttle screw is cut off. As a result, the movable blade (cutting blade) stops at the foremost position. On the other hand, when the motor is reversed after the movable blade has moved to the forefront position, the screw shaft is displaced and the shuttle screw and the screw shaft are screwed together again. This restores power transmission of the motor to the shuttle screw. Therefore, the movable blade moves rearward from the forefront position.

As described above, in the electric reciprocating tool, at the forefront position of the movable blade, the mechanical part for temporarily releasing the threaded engagement between the shuttle screw and the screw shaft and re-engaging the shuttle screw and the screw shaft is electrically reciprocated. Must be provided on power tools. For this reason, the mechanism for reciprocating the movable blade back and forth becomes complicated, which may increase the number of parts and reduce the durability of the parts. In addition, since the screw fitting is released once, if the screw fitting is not performed correctly, there is a possibility that a problem may occur.

SUMMARY OF THE INVENTION In consideration of the above facts, it is an object of the present invention to provide a work machine capable of suitably reciprocating a cutting blade.

One or more embodiments of the present invention include a housing, a motor accommodated in the housing, a control section for controlling the motor, an operation section for operating the motor when turned on, and the motor. a cutting blade that moves between an initial position and a reversed position along a first direction, and a support that supports a workpiece, and the workpiece is cut by the cutting blade and the support. In the work machine, in a state in which the cutting blade is at the initial position, the support portion and the cutting blade do not overlap when viewed in a second direction orthogonal to the first direction, and the control portion controls the cutting blade. When the operation portion is turned on while the blade is in the initial position, the motor is rotated forward to move the cutting blade closer to the support portion, and the operation portion is turned on. In the work machine, the motor is stopped or reversed in a state in which at least a part of the support portion and the cutting blade overlap when viewed in the second direction.

In one or more embodiments of the present invention, the cutting blade has a plate shape extending in the first direction and the second direction, and the control section is configured to extend in both the first direction and the second direction. The working machine is configured to stop the motor or reverse the motor at a position where the support portion and the cutting blade overlap when viewed in a third direction perpendicular to .

In one or more embodiments of the present invention, the support portion is provided with a recess in which a portion of the work piece can be positioned, and the control portion is configured such that when viewed in the third direction, the The working machine is configured to stop the motor or reverse the motor at a position where the recess overlaps the cutting blade.

One or more embodiments of the present invention include a housing, a motor housed in the housing, a control section for controlling the motor, an operation section for operating the motor when operated, and and an output unit that is rotationally driven and is screwed with the output unit, and when the motor rotates forward, it operates in one direction, and when the motor rotates backward, it operates in the other direction opposite to the one direction. A moving member that moves and a cutting blade configured to move integrally with the moving member. The working machine is configured to stop the motor while the screw engagement between the moving member and the moving member is maintained.

According to one or more embodiments of the present invention, the working machine has a position detection section that detects the position of the moving member, and the control section drives and controls the motor based on the detection result of the position detection section. is.

One or more embodiments of the present invention include a housing, a motor housed in the housing, an operation part provided in the housing for operating the motor when operated, and a motor movable in the housing. a moving member accommodated and reciprocally moved between an initial position and a reversed position by the driving force of the motor; a blade that approaches the workpiece by moving toward the outward path, a position detection unit that detects the position of the moving member, a control unit that drives and controls the motor based on the detection result of the position detection unit; It is a work machine equipped with

In one or more embodiments of the present invention, the position detection section includes an initial position detection section that detects the initial position of the moving member, a reverse position detection section that detects the reverse position of the movement member, The control unit detects the initial position of the moving member based on the detection result of the initial position detection unit, and adjusts the movement member based on the detection result of the reverse position detection unit. It is a work machine that detects the reversing position.

In one or more embodiments of the present invention, the position detection section is configured to detect the initial position of the moving member, and the control section detects the initial position of the moving member based on the detection signal of the position detection section. In the work machine, the initial position of the moving member is detected, and the reverse position of the moving member is detected based on the number of rotations of the motor from the initial position.

In one or more embodiments of the present invention, the position detection unit is turned on by being pressed by the moving member when the moving member moves from the reverse position to the initial position on the return path side. It is a switching switch, and the control unit is a work machine that starts measuring the number of revolutions of the motor, starting from the point in time when the position detection unit switches from on to off.

In one or more embodiments of the present invention, the control unit drives and controls the motor so as to move the moving member toward the return path after a predetermined time has elapsed since the reversal position of the moving member was detected. It is a work machine that

In one or more embodiments of the present invention, if the control unit does not detect the initial position of the moving member at the start of operation of the operating unit, the control unit moves the moving member toward the return path. It is a work machine that drives and controls the motor so as to cause the motor to move.

In one or more embodiments of the present invention, when the operation of the operation unit is released during movement of the moving member from the initial position to the reversing position in the forward direction, the moving member moves in the backward direction. In the work machine, the control unit drives and controls the motor so as to cause the motor to move.

In one or more embodiments of the present invention, the position detection unit is a work machine provided at a lateral position of the moving member.

In one or more embodiments of the present invention, the housing includes a first housing that accommodates the moving member, a second housing that accommodates the motor and the control section, and at least part of the position detection section. It is a work machine having a third housing that accommodates it.

In one or more embodiments of the present invention, the third housing is a work machine supported by the first housing or the second housing.

According to the work machine having the above configuration, the cutting blade can be preferably reciprocated.

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

An electric cutting machine 10 as a work machine according to the present embodiment will be described below with reference to the drawings. An arrow UP, an arrow FR, and an arrow RH appropriately shown in the drawings indicate the upper side, the front side, and the 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, the up/down, front/rear, and left/right directions of the electric cutting machine 10 are indicated unless otherwise specified. Further, the front-back direction corresponds to the first direction of the present invention, the up-down direction corresponds to the second direction of the present invention, and the left-right direction corresponds to the third direction of the present invention.

As shown in FIGS. 1 and 2, the electric cutting machine 10 is configured as an electric power tool for cutting a workpiece W such as a light ceiling bar used for a suspended ceiling of a building. This workpiece W is formed in a long columnar shape, and is formed in a substantially U shape when viewed from the longitudinal direction. The electric cutting machine 10 includes a housing 20, a motor 50, a feed screw mechanism 60 (in a broad sense, it is an element grasped as a movement mechanism), a blade 72 as a cutting edge (tip tool), and a guide mechanism 80. , a holding mechanism 90 , and a control unit 100 . Each configuration of the electric cutting machine 10 will be described below.

(Regarding the housing 20) The housing 20 constitutes the outer shell of the electric cutting machine 10 and extends in the front-rear direction as a whole. The housing 20 includes a lifter housing 22 (first housing) forming a front portion of the housing 20 and a body housing 24 (second housing) forming a rear portion of the housing 20 . The body housing 24 is formed in a substantially inverted P-shaped hollow shape when viewed from the right side, and the lifter housing 22 is formed in a substantially cylindrical shape extending in the front-rear direction. A front end portion of the body housing 24 and a rear end portion of the lifter housing 22 are connected via a spacer 26 . The lifter housing 22 is made of resin.

A rear end portion of the body housing 24 is configured as a handle portion 24A that is gripped by an operator, and the handle portion 24A extends vertically. A trigger 30 as an operating portion is provided at the upper end portion of the handle portion 24A. The trigger 30 is configured to be capable of being pulled rearward, and is turned on by being pulled. A trigger switch 31 is provided on the handle portion 24</b>A behind and obliquely below the trigger 30 . When the trigger 30 is pulled, the trigger switch 31 is switched from off to on.

The trigger switch 31 is electrically connected to a control section 100 which will be described later, and the control section 100 is accommodated in the lower end portion of the body housing 24 . Then, when the trigger switch 31 is turned on, the trigger switch 31 outputs an ON signal to the control section 100 .

A battery mounting portion 24B is formed at the lower end portion of the body housing 24 . A battery terminal 28 is provided in the battery mounting portion 24B, and the battery terminal 28 is electrically connected to the control portion 100, which will be described later. A battery 32 is detachably attached to the battery attachment portion 24B, and the battery 32 has a connector (not shown) connected to the battery terminal 28 . As a result, electric power is supplied to the motor 50 to be described later via the control unit 100 .

The lifter housing 22 has an undivided integral structure and is formed in a substantially cylindrical shape. As shown in FIG. 3A, the front end portion 23 of the lifter housing 22 is formed so as to be spaced apart in the left-right direction. A pair of upper and lower flange portions 23A are formed at the front end portion 23 of the lifter housing 22, and the flange portions 23A extend outward from the front end portion 23 in the vertical direction.

The front end portion 23 of the lifter housing 22 is provided with a support mechanism 40 for supporting a lifter 65 of a feed screw mechanism 60, which will be described later. The support mechanism 40 will be described below.

(Support Mechanism 40) As shown in FIGS. 2, 3(A), and 4(A), the support mechanism 40 includes a pair of left and right fixing plates 41 and an outer guide 44 (in a broad sense, a support member ) and an inner guide 45 as a rotating shaft.

The fixing plate 41 is formed in a substantially elongated plate shape with the lateral direction as the plate thickness direction and the vertical direction as the longitudinal direction. A curved portion 41A is formed in the vertical intermediate portion of the fixing plate 41. The curved portion 41A has a generally arcuate shape that projects outward in the left-right direction when viewed from the front side, corresponding to the outer shape of the lifter housing 22. formed. The fixing plate 41 is arranged inside the front end portion 23 of the lifter housing 22 in the left-right direction, and the upper end portion and the lower end portion of the fixing plate 41 are arranged adjacently inside the flange portion 23A of the lifter housing 22 in the left-right direction. there is

Sleeves 42 are laid over the upper and lower ends of the pair of left and right fixing plates 41 . The sleeve 42 is formed in a substantially cylindrical shape whose axial direction is the left-right direction, and a pair of fixing plates 41 are fixed to the sleeve 42 . Both longitudinal ends of the sleeve 42 protrude laterally outward beyond the fixing plate 41 , and the lifter housing 22 is formed with insertion holes 23</b>B through which the 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 screwed into the nut 43 . Thereby, the fixed plate 41 is fixed to the lifter housing 22 . The inner diameter of the insertion hole 23B is slightly smaller than the outer diameter of the sleeve 42, and the sleeve 42 is press-fitted into the insertion hole 23B.

The outer guide 44 is formed in a substantially cylindrical shape whose axial direction is the front-rear direction. The outer guide 44 is arranged between the curved portions 41A of the pair of fixed plates 41 . Both left and right ends of the outer guide 44 are fastened and fixed 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 plate 41 , the tip of the bolt BL<b>2 protrudes radially inward of the outer guide 44 . Also, in this state, the head of the bolt BL2 is arranged in the notch 23C formed in the lifter housing 22 (see FIG. 1).

The inner guide 45 is formed in a substantially cylindrical shape whose axial direction is the front-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 set longer than the axial length of the outer guide 44 . A 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 peripheral portion of the rear portion of the inner guide 45. formed throughout. The tip of the bolt BL2 is inserted into the guide groove 45A so as to allow relative rotation of the inner guide 45 with respect to the outer guide 44. As shown in FIG. As a result, the movement of the inner guide 45 in the front-rear direction is restricted by the bolt BL2. A rubber O-ring 46 is provided between the inner guide 45 and the lifter body 66 . There is a slight gap between the inner guide 45 and the lifter main body 66 so that the lifter main body 66 can move slightly relative to the inner guide 45 in the radial direction. compresses and dampens movement. That is, the lifter main body 66 is supported so as to be movable in directions (vertical and horizontal directions) intersecting the front-rear direction, which is the direction driven by the motor 50 . The elastic body is elastically deformed (that is, the O-ring 46 is compressed and deformed) during the movement.

As shown in FIG. 3B, the front portion of the inner guide 45 is formed with a pair of upper and lower slits 45B for arranging a blade 72, which will be described later. The slit 45B extends in the front-rear direction and penetrates in the up-down direction, and the front end of the slit 45B opens forward. In addition, the inner guide 45 constitutes a part of a guide mechanism 80 which will be described later.

(Motor 50 ) As shown in FIG. 2 , the motor 50 is configured as a brushless motor and housed in the front end of the body housing 24 . The motor 50 includes a drive shaft 51 whose axial direction is the front-rear direction, a substantially cylindrical rotor 52 fixed to the drive shaft 51, and a substantially cylindrical stator 53 arranged radially outside the rotor 52. is composed of A rear end portion of the drive shaft 51 is rotatably supported by a motor bearing 54 held by the main body housing 24, and a front end portion of the drive shaft 51 is rotatably supported by a motor bearing 55 held by the spacer 26. Supported. A pinion gear 51A is formed at the front end of the drive shaft 51 . The motor 50 is electrically connected to the controller 100 and driven under the control of the controller 100 . The motor bearing 55 is a well-known ball bearing, and is a bearing member including an inner ring, an outer ring, and balls provided therebetween.

(Regarding the feed screw mechanism 60) As shown in FIGS. 2 and 5, the feed screw mechanism 60 includes 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 detector for detecting the position of the lifter 65 .

The transmission gear 61 has a base portion 61A and a gear portion 61B. The base portion 61A is formed in a substantially stepped columnar shape whose axial direction is the front-rear direction, and the diameter of the front portion of the base portion 61A is set larger than the diameter of the rear portion of the base portion 61A. A recess 61C that is open to the front (recessed to the rear) is formed in the center of the front side of the base 61A. The transmission gear 61 is accommodated in the housing 20 above the front end of the drive shaft 51 of the motor 50, and the rear portion of the transmission gear 61 is rotatably supported by a gear bearing 62 held by the spacer 26. . A gear portion 61B is attached to the outer peripheral portion of the front portion of the base portion 61A, and the gear portion 61B is meshed with the pinion gear 51A of the drive shaft 51. As shown in FIG. A front portion of the base portion 61A is press-fitted into an annular gear portion 61B. The gear portion 61B is a helical gear. The gear portion 61B is shaped so that when a load is applied to the blade 72, which will be described later, during work, a forward thrust force is applied to the transmission gear 61 (gear portion 61B) due to the meshing action with the pinion gear 51A. there is At least a portion of the gear bearing 62 is located at the same position as the motor bearing 55 in the longitudinal direction. In other words, at least part of the gear bearing 62 is positioned to overlap the motor bearing 55 when viewed in the radial direction (vertical direction). The base portion 61A and the gear portion 61B may be configured as a single component (integrated structure), but since they are configured as separate members, it is easy to form a complicated shape as described above. The gear bearing 62 is a well-known ball bearing, and is a bearing member including an inner ring, an outer ring, and balls provided therebetween. The outer ring of the gear bearing 62 is in contact with the spacer 26, and the inner ring is in contact with the transmission gear 61 (base portion 61A).

The drive shaft 63 is formed in a substantially columnar shape whose axial direction is the front-rear direction. The drive shaft 63 is accommodated in the lifter housing 22 and arranged coaxially with the transmission gear 61 on the front side of the transmission gear 61 . The rear end of the drive shaft 63 is fitted in the recess 61C of the transmission gear 61 so as to rotate integrally therewith, and the rear end of the drive shaft 63 is rotated by the shaft bearing 64 held by the lifter housing 22. supported as possible. As a result, the drive shaft 63 rotates (integrally with the transmission gear 61) when the motor 50 is driven. The recessed portion 61C has a key structure (for example, a structure having one or more flat portions), and the rear end portion of the drive shaft 63 has a similar shape. Further, the recessed portion 61C and the drive shaft 63 are fitted so that they can move relative to each other in the front-rear direction, which is a so-called "clearance fit" relationship. This allows the transmission gear 61 to move forward and backward. That is, the transmission gear 61 is supported so as to be movable in a direction (front-rear direction) that intersects the direction in which it is driven by the motor 50 (rotational direction centered on the front-rear direction, which is the vertical and horizontal directions). When the transmission gear 61 moves back and forth, it may move integrally with the shaft bearing 64 , or the transmission gear 61 may move relative to the shaft bearing 64 . It is important to connect the transmission gear 61 (recessed portion 61C) and the drive shaft 63 so that they can move relative to each other in the front-rear direction. . The shaft bearing 64 is a well-known ball bearing, and is a bearing member including an inner ring, an outer ring, and balls provided therebetween. A male screw 63A is formed on the outer peripheral portion of the drive shaft 63 except for the rear end portion. A rear portion of the drive shaft 63 is provided with a collar portion 63B. The rear side of the collar portion 63B is in contact with the front side of (the inner ring of) the shaft bearing 64 . The rear side of (the outer ring of) the shaft bearing 64 contacts and is supported by the bearing support portion 22B formed in the lifter housing 22 . Therefore, even if the drive shaft 63 tries to move rearward, the movement is restricted by the bearing support portion 22B (lifter housing 22) through the shaft bearing 64. As shown in FIG.

The lifter 65 is formed in a substantially elongated shape extending in the front-rear direction as a whole. The lifter 65 includes a lifter main body 66 and a lifter connecting portion 67 forming a rear end portion of the lifter 65 . The lifter connecting portion 67 is formed in a substantially stepped cylindrical shape whose axial direction is the front-rear direction. A female thread 67A is formed on the inner peripheral portion 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 screw 63A of the drive shaft 63 and the female screw 67A of the lifter connecting portion 67 are screwed together. That is, the drive shaft 63 and the lifter 65 are screwed together.

As a result, the drive shaft 63 rotates to move the lifter 65 in the front-rear direction (the axial direction of the drive shaft 63). Specifically, the lifter 65 reciprocates between the initial position (the position shown in FIG. 2) and the reverse position (the position shown in FIG. 5). The rotation of the lifter 65 during rotation of the drive shaft 63 is restricted by a guide mechanism 80, which will be described later. The reversal position may be rephrased as the terminal position.

A detected portion 67B is formed on the outer peripheral portion of the rear end portion of the lifter connecting portion 67 . The detected portion 67B projects radially outward from the lifter main body 66 and is formed in a substantially columnar shape with the front-rear direction as the thickness direction.

The lifter main body 66 is formed in a substantially bottomed cylindrical shape that is open rearward. The rear end portion of the lifter main body 66 is fitted into the front portion of the lifter connecting portion 67 so that the lifter connecting portion 67 and the lifter main body 66 are connected so as not to move relative to each other. At the initial position of the lifter 65, the front portion of the drive shaft 63 is inserted into the lifter main body 66 so as to be relatively movable. A front end portion of the lifter body 66 is inserted into the inner guide 45 of the support mechanism 40 described above, and supported by the inner guide 45 so as to be relatively movable in the front-rear direction.

A lifter flange 66A is formed on the outer peripheral portion of the rear end portion of the lifter main body 66. The lifter flange 66A is formed in a disc shape protruding radially outward from the lifter main body 66. As shown in FIG. At the reverse position of the lifter 65, the lifter flange 66A is arranged close to the rear side of the inner guide 45. As shown in FIG. When the lifter main body 66 and the lifter connecting portion 67 are connected, the front end of the lifter connecting portion 67 is arranged adjacent to the rear side of the lifter flange 66A of the lifter main body 66 .

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

A spherical ball 70 is provided above the lifter detection switch 68 , and the ball 70 is arranged in a ball hole 22</b>A formed in the lower end of the outer periphery of the lifter housing 22 . The ball hole 22A penetrates in the vertical direction, and the diameter of the ball hole 22A increases downward. When the lifter detection switch 68 is in the OFF state, the outer peripheral surface of the ball 70 is in contact with the lever portion of the lifter detection switch 68 and the inner peripheral surface of the ball hole 22A (see FIG. 5). Further, in this state, a part of the outer peripheral portion of the ball 70 protrudes radially inward with respect to the inner peripheral surface of the lifter housing 22 so as to be arranged inside the lifter housing 22 . Ball 70 is a transmission member for transmitting the operation of lifter 65 to lifter detection switch 68 . The ball hole 22A is a communication hole that communicates the inside of the lifter housing 22 and the inside of the switch cover 69 .

When the lifter 65 is located at the initial position, the outer peripheral portion of the detected portion 67B of the lifter 65 presses the ball 70 radially outward (lower side), and the ball 70 moves toward the lifter detection switch 68 (lower side). side). That is, when the lifter 65 reaches the initial position while the lifter 65 is moving from the reverse position to the initial position, the ball 70 presses the lever portion of the lifter detection switch 68 to turn the lifter detection switch 68 from off to on. is configured to switch to Also, the lifter detection switch 68 is electrically connected to the control section 100 and outputs a detection signal to the control section 100 . That is, the lifter detection switch 68 is configured to transmit an ON signal to the control section 100 when pressed by the ball 70 .

(Regarding the blade 72) As shown in Figs. 1, 2, 3(B), and 4(A), the blade 72 is formed in a plate-like shape with the left-right direction as the plate thickness direction. That is, the blade 72 has a plate shape extending in the front-back direction and the up-down direction. A rear end portion of the blade 72 is fixed to a front end portion of the lifter 65 . Specifically, a stepped portion 66C (see FIG. 4A) is formed at the front end portion of the lifter body 66, and a pin P arranged in the stepped portion 66C lifts the vertical intermediate portion of the rear end portion of the blade 72. is locked. Thereby, the blade 72 is configured to be movable between the initial position and the reverse position integrally with the lifter 65 . In addition, when the blade 72 is fixed to the lifter 65 , the blade 72 is arranged so as to overlap the center lines of the lifter 65 and the drive shaft 63 when viewed from the front side.

A front end portion of the blade 72 is configured as a blade portion 72A for cutting the workpiece W. As shown in FIG. The blade portion 72A is configured as a single-edged blade, and is formed in a substantially V-shape that protrudes forward when viewed from the left-right direction.

In the initial position of the blade 72, the blade 72 is arranged on the front side of the lifter housing 22 and on the rear side of the workpiece W. As shown in FIG. Then, the workpiece W is cut by moving the blade 72 forward from the initial position. Furthermore, at the reversal position of the blade 72, the cutting of the workpiece W is completed.

(Regarding the guide mechanism 80) As shown in FIGS. 1, 2, 3(B), and 4 to 6, the guide mechanism 80 (adjustment mechanism) includes the inner guide 45 of the support mechanism 40 described above, It includes a guide plate 81 as a pair of left and right guide members, a connecting member 82, and a pair of left and right head plates 83 as a head portion. The head plate 83 is a member that covers the blade 72 in the reversed position from the left and right, and functions as a member (supporting portion) that supports the workpiece W. As shown in FIG. In some cases, the workpiece W is fixed to a specific location (wall, ceiling, etc.). The state is also assumed to be a state in which the head plate 83 supports the workpiece W. As shown in FIG. Also, the guide mechanism 80 is connected to the housing 20 .

The guide plate 81 is formed in a substantially rectangular plate shape whose plate thickness direction is the left-right direction. A curved portion 81A (see FIG. 3B) is formed in the vertical intermediate portion of the guide plate 81, and the curved portion 81A corresponds to the outer shape of the inner guide 45 when viewed from the front side. It is formed in a generally arcuate shape that protrudes outward. The curved portion 81A is arranged radially outward of the inner guide 45 and fastened and fixed to the inner guide 45 by a pair of front and rear bolts BL3. Thereby, the guide plate 81 is connected to the inner guide 45 so as to rotate integrally therewith. In other words, the guide mechanism 80 is rotatably connected to the housing 20 with the front-rear direction as its axial direction. That is, the inner guide 45 is configured as a rotating shaft of the guide mechanism 80 and also as a bearing member of the lifter 65 .

Further, a portion above the curved portion 81A of the guide plate 81 is configured as a guide portion 81B, and a portion below the curved portion 81A of the guide plate 81 is configured as a connecting portion 81C. The guide portions 81B of the pair of guide plates 81 are arranged to face each other with a predetermined gap in the left-right direction, and the connecting portions 81C of the pair of guide plates 81 face each other with a predetermined gap in the left-right direction. are placed. 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 slightly longer than the plate thickness of the blade 72 . In addition, an escape portion 81D (see FIG. 2) is formed at the corner of the rear end portion of the connecting portion 81C. missing.

A blade 72 is arranged between the pair of guide plates 81 . Moreover, the relative rotation of the guide plate 81 (guide mechanism 80 ) with respect to the housing 20 is restricted by a holding mechanism 90 to be described later. As a result, when the drive shaft 63 rotates, the lifter 65 and the blade 72 are restricted from rotating together with the drive shaft 63 by the guide portion 81B of the guide plate 81, and the blade 72 reciprocates in the front-rear direction along the guide portion 81B. It is configured to move. A slight gap (space) is provided between the guide portion 81B and the blade 72, and the blade 72 is configured to be able to rotate by this gap. The size is so small that it has no effect. In particular, the gap between the guide portions 81B is a size that prevents the blade 72 from coming off the area between the pair of head plates 83 (the gap in the left-right direction). In other words, the interval between the guide portions 81B is set to such a size that the blade 72 moving toward the reversing position does not come into contact with the head plate 83. As shown in FIG. More specifically, the gap (left-right direction gap) between the pair of guide portions 81B is configured to be smaller than the gap (left-right direction gap) between the pair of head plates 83 . Further, in the holding mechanism 90 to be described later, when a rotational force (operating force) of a predetermined value or more is applied to the guide plate 81 (guide mechanism 80) by manual operation by an operator, the guide plate 81 relative to the housing 20 is displaced. Rotation is allowed. This changes the orientation of the blade 72 as seen from the front side. Specifically, the orientation of the blade portion 72A of the blade 72 viewed from the front side is changed. In other words, the guide mechanism 80 is also configured as a mechanism section that changes the orientation of the blade 72 with respect to the workpiece W viewed from the movement direction of the blade 72 by operating.

In this embodiment, the orientation of the blade 72 with respect to the workpiece W can be determined in two orientations by a stopper 94, which will be described later. More specifically, the stopper 94 allows the orientation of the blade 72 when the guide mechanism 80 is placed in the first position (the position shown in FIGS. 1 and 2) and the orientation of the blade 72 when the guide mechanism 80 is rotated 180 degrees from the first position. The orientation of the blade 72 when placed in two positions (the position shown in FIG. 6) and the orientation of the blade 72 can be determined in two directions.

The connecting member 82 is formed in a substantially elongated plate shape extending in the front-rear direction with the thickness direction being the left-right direction. A connecting member 82 is arranged between the connecting portions 81C of the pair of guide plates 81 and fastened and fixed to the guide plates 81 with bolts BL4.

The head plate 83 is formed in a plate shape having a plate thickness direction in the left-right direction. The head plate 83 is arranged on the front side of the guide plate 81 and laterally outside of the connecting member 82, and the lower end of the head plate 83 is fastened and fixed to the front end of the connecting member 82 with bolts BL4. The head plate 83 functions as a support portion that supports the workpiece W, and has characteristics that match the shape of the workpiece W, so that workability can be improved. In the case of the present embodiment, head recesses 83A (notches) are formed as a plurality of (four in the present embodiment) recesses at the rear end of the head plate 83. The head recesses 83A are It is formed in a concave shape that opens rearward and penetrates in the left-right direction. With this configuration, it is possible to suitably cut the workpiece W having a U-shaped cross section. That is, when cutting the workpiece W, both ends of the workpiece W viewed from the longitudinal direction of the workpiece W are inserted into the head recesses 83A to set (support) the workpiece W. It's becoming In this manner, the workpiece W is supported by the head plate 83 while being partially positioned in the head recess 83A. In this embodiment, since the head recesses 83A are provided at four locations, it is possible to cut the workpiece W having a width corresponding to the combination of the recesses. The shape of the head concave portion 83A can be appropriately changed according to the shape of the workpiece. The head concave portion 83A is an example of a notch 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 restricting member and a pair of stoppers 94 . As shown in FIG. 6, the wave washer 92 is formed in a substantially disc shape with the front-rear direction as the plate thickness direction. The wave washer 92 is arranged between the curved portion 81A of the guide plate 81 and the lifter housing 22, and the frictional force generated between the wave washer 92, the guide plate 81 and the lifter housing 22 causes the guide plate 81 to move. is configured to limit the rotation of the More specifically, when the drive shaft 63 is rotated by driving the motor 50, the lifter 65 and the blades 72 tend to rotate together with the drive shaft 63, so that a rotational force is input from the blades 72 to the guide plate 81. , and the shape of the wave washer 92 is set so that the guide plate 81 does not rotate. On the other hand, the rotation of the guide plate 81 is permitted when a rotational force (operating force) greater than or equal to a predetermined value is input to the guide plate 81 by manual operation by the operator. That is, the wave washer 92 is configured to function as a so-called torque limiter member.

As shown in FIGS. 1 to 6, the stopper 94 is configured as a member that determines the rotational position of the guide plate 81 and determines the orientation of the blade 72 with respect to the workpiece W. As shown in FIG. Specifically, when the guide mechanism 80 is manually rotated (operated), the guide plate 81 abuts against the stopper 94 to prevent the rotation of the guide plate 81, thereby preventing the blade 72 from being affected. An orientation with respect to the workpiece W is determined.

The stopper 94 includes a fixed portion 94A fixed to the housing 20 and a contact portion 94B configured to contact the guide plate 81 . The fixed portion 94A is formed in a substantially rectangular plate shape whose plate thickness direction is the left-right direction. The fixed portions 94A are arranged on the right side of the upper and lower flange portions 23A of the lifter housing 22, respectively, and are fastened together to the lifter housing 22 with bolts BL1.

The contact portion 94B is formed in a substantially rectangular columnar shape extending in the left-right direction. The contact portion 94B is arranged on the front side of the lifter housing 22, and the right end portion of the contact portion 94B is connected to the vertical outer end portion of the fixed portion 94A. 1 and 3B, in the first position of the guide mechanism 80, the upper contact portion 94B contacts the rear end portion of the guide portion 81B of the guide plate 81 from the right side. , counterclockwise rotation of the guide mechanism 80 viewed from the front side is restricted. Further, at the first position of the guide mechanism 80, the left end of the lower contact portion 94B is arranged in the relief portion 81D of the guide plate 81 to avoid interference between the guide plate 81 and the lower stopper 94. It is

When the guide mechanism 80 is rotated 180 degrees clockwise from the first position as viewed from the front side, the rear end of the guide portion 81B of the guide plate 81 abuts on the lower abutment portion 94B and guides the guide. The clockwise rotation of the mechanism 80 is restricted, and the position of the guide mechanism 80 is determined at the second position (see FIG. 6). At the second position of the guide mechanism 80, the left end portion of the upper contact portion 94B is arranged within the relief portion 81D of the guide plate 81, thereby avoiding interference between the guide plate 81 and the upper stopper 94. Thus, the pair of stoppers 94 are also configured as members that determine the operating rotation angle range of the guide mechanism 80 . In other words, the pair of stoppers 94 determines the relative rotation angle range of the lifter 65 with respect to the drive shaft 63 when the guide mechanism 80 is actuated, and limits excessive relative movement of the lifter 65 with respect to the drive shaft 63. are doing. In this embodiment, the pair of stoppers 94 set the operating rotation angle range of the guide mechanism 80 to 180 degrees. That is, the operating range of the guide mechanism 80 is set to one rotation or less.

(Control Unit 100) As shown in FIG. 2, the control unit 100 is accommodated in the lower end portion of the body housing 24 and held by the body housing 24. As shown in FIG. The trigger switch 31 , the motor 50 and the lifter detection switch 68 are electrically connected to the controller 100 . The control section 100 detects the initial position of the lifter 65 based on the detection signal from the lifter detection switch 68 . Further, the control unit 100 drives and controls 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 forward, the lifter 65 (the blade 72) moves forward, and when the control unit 100 drives the motor 50 in the reverse direction, the lifter 65 (the blade 72) moves backward. It is designed to move to the side.

Further, when the operation of the trigger 30 is released and the trigger switch 31 is switched from ON to OFF while the motor 50 is driving forward, the control unit 100 reversely drives the motor 50 . Further, 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 having a plurality of Hall ICs, and is capable of detecting the magnetism of the permanent magnets provided on the rotor 52 . The control unit 100 is configured to be able to detect the rotation position and rotation speed of the rotor 52 (motor 50) based on the signal from the rotation speed measurement unit 100A. Since the rotation speed measurement unit 100A needs to be arranged near the rotor 52, it is arranged apart from the control unit 100 by connecting with a signal line. The control unit 100 can detect how many times the motor 50 has rotated from the initial position based on the signal from the rotation speed measurement unit 100A. Thereby, the control unit 100 detects the reverse position of the lifter 65 (blade 72) based on the number of rotations of the motor 50 with the initial position of the lifter 65 as the starting point. Further, when detecting the reverse position of the lifter 65 (blade 72), the control unit 100 switches the motor 50 from normal rotation to reverse rotation. In this way, the rotation speed measurement section 100A functions as part of the position detection section. More specifically, the number-of-revolutions measurement unit 100A functions as a reversal position detection unit that detects that the lifter 65 is positioned at the reversal position. Thus, the position detection section in the present invention includes the lifter detection switch 68 and the rotation speed measurement section 100A. The lifter detection switch 68 directly detects the initial position of the lifter 65, and the rotational speed measurement section 100A indirectly detects the reversed position of the lifter 65. FIG. The timing at which the controller 100 starts measuring the number of revolutions of the motor 50 will be described later.

(Action and Effect) Next, while explaining the operation of the electric cutting machine 10, the action and effect of the electric cutting machine 10 of the present embodiment will be explained.

A flow chart of the electric cutting machine 10 is described in FIG. As shown in this figure, in the operation of the electric cutting machine 10, in step 1 (S1), the control unit 100 determines whether or not the trigger switch 31 is on based on the output signal from the trigger switch 31. To detect. That is, the control unit 100 determines whether the trigger 30 has been operated. In step 1, if the trigger switch 31 is not turned on (No in step 1), the process returns to step 1. If the trigger switch 31 is turned on in step 1 (Yes in step 1), the process proceeds to step 2 (S2).

In step 2, the control section 100 detects whether or not the lifter detection switch 68 is turned on based on the output signal from the lifter detection switch 68 . That is, the control unit 100 determines whether or not the lifter 65 is arranged at the initial position. In step 2, if the lifter detection switch 68 is on (Yes in step 2), the process proceeds to step 3 (S3).

In step 3, the control unit 100 causes the motor 50 to rotate forward. 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 forward. As a result, the lifter 65 and the blade 72 move forward (forward path side). That is, lifter 65 and blade 72 approach the workpiece. After the processing of step 3, the process proceeds to step 4 (S4).

In step 4, the control unit 100 detects whether or not the trigger switch 31 continues to be on based on the output signal from the trigger switch 31 . That is, the control unit 100 determines whether the operation of the trigger 30 is continued. In step 4, when the ON state of the trigger switch 31 continues (in the case of Yes in step 4), the process proceeds to step 5 (S5).

At step 5, based on the output signal from the lifter detection switch 68, the control section 100 detects whether or not the lifter detection switch 68 has been switched from ON to OFF. If the lifter detection switch 68 is turned off in step 5 (Yes in step 5), the process proceeds to step 6 (S6). That is, in the present embodiment, the position of the lifter 65 at which the lifter detection switch 68 is switched from ON to OFF is 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 position of the lifter 65 . On the other hand, if the lifter detection switch 68 is not turned off in step 5 (No in step 5), the process returns to step 4. In other words, when the lifter 65 moving forward from the initial position has not reached the initial starting point position, the process returns to step 4 .

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

At step 7, the control section 100 detects whether or not the trigger switch 31 is kept on based on the output signal from the trigger switch 31. FIG. That is, the control unit 100 determines whether the operation of the trigger 30 is continued. In step 7, when the ON state of the trigger switch 31 continues (in the case of Yes in step 7), the process proceeds to step 8 (S8).

At step 8, the control unit 100 determines whether or not the number of rotations of the motor 50 has reached or exceeded a predetermined number of rotations. That is, the control unit 100 determines whether or not the lifter 65 has reached the reverse position. In step 8, if the number of rotations of the motor 50 is not equal to or greater than the predetermined number of rotations (No in step 8), the process returns to step 7. In step 8, when the number of rotations of the motor 50 is equal to or higher than the predetermined number of rotations (Yes in step 8), the process proceeds to step 9 (S9).

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

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

In step 11, the control unit 100 drives the motor 50 in reverse. As a result, the lifter 65 and the blade 72 are moved rearward (return side) and separated from the workpiece W. As shown in FIG. That is, the lifter 65 and the blade 72 are reversed at the reverse position, and the return movement of the lifter 65 and the blade 72 is started. After the processing of step 11, the process proceeds to step 12 (S12).

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

At step 13, the reverse rotation of the motor 50 by the controller 100 is stopped. As a result, the lifter 65 stops at the initial position. After the processing of step 13, the process proceeds to step 14 (S14). By stopping the reverse driving of the motor 50, the lifter 65 returns to the initial position. However, due to the braking time of the motor 50, etc., the lifter 65 stops at a position where it overruns from the initial starting position toward the return path ( Hereinafter, the position of the lifter 65 will be referred to as an initial stop position).

At step 14, the control unit 100 detects whether or not the trigger switch 31 has been switched from on to off based on the output signal from the trigger switch 31. FIG. That is, the control unit 100 detects whether or not the operation of the trigger 30 has been released. In step 14, if the trigger switch 31 is not off (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 electric cutting machine 10 is terminated because the operation of the trigger 30 has been released.

If the lifter detection switch 68 is not turned on in step 2 (No in step 2), step 11 is performed. That is, in this case, since the lifter 65 has not returned to the initial position when the electric cutting machine 10 starts operating, the process proceeds to step 11 to return the lifter 65 to the initial position.

If the ON state of the trigger switch 31 is not continued in steps 4 and 7 (No in steps 4 and 7), step 9 is performed. That is, in this case, the operator's operation of the trigger 30 is released while the lifter 65 is moving forward. Therefore, the control unit 100 stops forward rotation of the motor 50 and rotates the motor 50 in reverse rotation after a predetermined period of time has elapsed, thereby returning the lifter 65 to the initial position.

The operation of the electric cutting machine 10 will be described with reference to the time chart shown in FIG. As shown in this figure, the lifter 65 is located at the initial stop position at time T0 when the electric cutting machine 10 is in a non-operating state. Therefore, at time T0, the lifter detection switch 68 is turned on. At time T0, the electric cutting machine 10 is in a non-operating state, so the trigger switch 31 is turned off.

At time T1, when the trigger switch 31 is turned on, the forward rotation of the motor 50 is started by the control unit 100, the output of the motor 50 gradually increases from zero, and the rotational speed of the motor 50 increases from zero. gradually become higher. As a result, the lifter 65 moves from the initial stop position toward the outward path.

At time T2, the lifter 65 reaches the initial starting position, and the lifter detection switch 68 is switched from on to off. As a result, the rotation speed measurement of the motor 50 in the control unit 100 is started at the time T2. That is, counting of the number of rotations of the motor 50 in the control unit 100 is started.

At time T3, the lifter 65 reaches the reversing position, and the number of revolutions of the motor 50 reaches a predetermined number. As a result, forward rotation driving of the motor 50 by the control unit 100 is stopped. That is, the power supplied to the motor 50 becomes zero, and the rotational speed of the motor 50 gradually decreases. At time T3, the number of rotations counted by the motor 50 reaches a predetermined number of times, so the control unit 100 resets the counted number of rotations to zero.

At time T4, the rotational speed of motor 50 becomes zero. At time T5, the control unit 100 starts to reversely drive the motor 50, the output of the motor 50 gradually increases from zero, and the rotational speed of the motor 50 gradually increases from zero. As a result, the lifter 65 moves from the reversal position to the return path side. That is, the time from time T3 to time T5 is the standby time during which the motor 50 is placed in the standby state.

At time T6, the lifter 65 reaches the initial starting position and the lifter detection switch 68 is switched from off to on. As a result, the reverse driving of the motor 50 by the controller 100 is stopped. That is, the output of the motor 50 becomes zero, and the rotation speed of the motor 50 gradually decreases.

At time T7, the rotation speed of the motor 50 becomes zero, and the lifter 65 reaches the initial stop position.

Note that the above time chart shows an example in which the operator's operation of the trigger 30 is released between time T5 and time T6. That is, the operation of the trigger 30 is canceled while the lifter 65 is moving backward. Therefore, the control unit 100 continues to reversely drive the motor 50, and the lifter 65 is returned to the initial position.

As described above, according to the electric cutting machine 10 of the present embodiment, the feed screw mechanism 60 has the lifter detection switch 68 that detects the initial position of the lifter 65 . Then, the controller 100 detects the initial position of the lifter 65 based on the detection signal from the lifter detection switch 68 . As a result, when the lifter 65 is at the initial position, the control unit 100 drives the motor 50 to rotate forward, thereby moving the lifter 65 forward from the initial position to the reverse position. Also, the control unit 100 detects the reversing position of the lifter 65 based on the rotation speed of the motor 50 . As a result, the motor 50 is stopped at the reverse position of the lifter 65, and the cutting of the workpiece W by the blade 72 can be finished. Then, the control unit 100 reversely drives the motor 50 to move the lifter 65 backward from the reverse position to the initial position, thereby stopping the motor 50 at the initial position.

Thus, according to the electric cutting machine 10 of the present embodiment, the control section 100 can detect the initial position and the reverse position based on the detection signal of the lifter detection switch 68 and the rotation speed of the motor 50. . That is, the control unit 100 drives and controls 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, in the state in which the blade 72 is moved by driving the motor 50, the control unit 100 controls the movement of the blade 72 as viewed from the left-right direction perpendicular to the front-rear direction and the up-down direction even if the trigger 30 is maintained in the ON state (pulled state). The motor 50 can be stopped in a state in which a portion of the blade 72 and the head plate 83 overlap with each other. In addition, the control unit 100 can stop the motor 50 so that the drive shaft 63 and the lifter 65 are not disengaged while the blade 72 is being moved by driving the motor 50 . In other words, the motor 50 can be stopped while the screwed state between the drive shaft 63 and the lifter 65 is maintained. As a result, the lifter 65 can be moved at the reversing position without providing a switching mechanism for switching the transmission path of the driving force of the motor to the lifter between the disconnected state and the connected state, for example, as in the electric cutting machine described in the background art. Can be stopped or reversed. In other words, when the blade 72 partially overlaps the head plate 83 when viewed in the left-right direction, that is, when the workpiece W is cut by the blade 72, the control unit 100 It is configured to stop the motor 50 even if the trigger 30 is kept on. Therefore, the lifter 65 and blade 72 can be preferably moved. In particular, the control unit 100 is configured to stop the motor 50 even when the trigger 30 is maintained in the ON state (pulled state) in a state where the head concave portion 83A and the blade 72 overlap when viewed in the horizontal direction. . As a result, even when part of the workpiece W is positioned in the head concave portion 83A, the cutting operation can be preferably performed. Note that when the blade 72 is positioned at the reverse position, the motor 50 may be maintained in a stopped state, or may be immediately reversed without being stopped. In addition, since the material to be processed has various shapes, from thin to complicated, the timing of stopping the motor 50 is determined when a part of the blade 72 overlaps the head plate 83 when viewed in the left-right direction. If there is, it can be changed arbitrarily. That is, when cutting a thin material, it may be stopped or reversed early, and when cutting a workpiece W having a complicated shape using the head recess 83A, the motor is operated while the blade 72 and the head recess 83A overlap each other. 50 should be stopped or reversed. Furthermore, since the motor 50 automatically stops when the lifter 65 is positioned at the reverse position, the operator can recognize that the machining is completed. This improves workability. In addition, by providing the reciprocating lifter 65 with a female screw 67A and providing the drive shaft 63 with a male screw 63A, the lifter 65 can be configured to operate outside the drive shaft 63, and the inside of the lifter 65 can be configured. The position of the lifter 65 can be easily detected compared to the configuration in which the drive shaft 63 operates.

Further, the lifter detection switch 68 is configured to switch from OFF to ON when the lifter 65 reaches the initial position while the lifter 65 is moving from the reverse position to the initial position in the backward direction. . Further, the control unit 100 starts measuring the number of revolutions of the motor 50 starting from the time when the lifter detection switch 68 is switched from ON to OFF. That is, the control unit 100 starts measuring the number of revolutions of the motor 50 starting from the initial starting position of the lifter 65 . As a result, the reversal position of the lifter 65 can be detected with high accuracy.

That is, as described above, when the lifter 65 returns to the initial position, the control unit 100 stops driving the motor 50 based on the detection signal that the lifter detection switch 68 switches from off to on. At this time, the lifter 65 stops at the initial stop position where the lifter 65 overruns the return path side from the initial starting position. Since this initial stop position is caused by the braking performance of the motor 50, etc., the initial stop position varies. Therefore, if the rotation speed measurement of the motor 50 is started from the initial stop position of the lifter 65, the reverse position of the lifter 65 may not be detected accurately.

On the other hand, in the present embodiment, as described above, the control unit 100 starts measuring the number of rotations of the motor 50 starting from the time when the lifter detection switch 68 is switched from on to off. Since the time at which the lifter detection switch 68 switches from on to off is constant, by starting to measure the number of revolutions of the motor 50 from the initial starting point position of the lifter 65, the reversing position of the lifter 65 can be accurately determined. can be detected well.

In particular, in the electric cutting machine 10 of this embodiment, the lifter 65 rotates relative to the drive shaft 63 when the guide mechanism 80 is operated to change the orientation of the blade 72 . That is, at this time, the lifter 65 moves forward and backward with respect to the drive shaft 63 . Therefore, the initial stop position of the lifter 65 before and after the operation of the guide mechanism 80 is shifted. Therefore, in the electric cutting machine 10 having the guide mechanism 80 for changing the direction of the blade 72, the reversal position of the lifter 65 is determined by starting the measurement of the number of revolutions of the motor 50 with the initial starting position of the lifter 65 as the starting point. It can be detected well.

Further, when the reverse position of the lifter 65 is detected, the control unit 100 reversely drives the motor 50 to move the lifter 65 toward the return path after a predetermined time has elapsed. Therefore, the operator can be made aware that the blade 72 has reached the reversing position and the cutting of the workpiece W by the blade 72 has been completed.

If the control unit 100 does not detect the initial position of the lifter 65 when the trigger 30 is started to be operated, the control unit 100 reversely drives the motor 50 so as to move the lifter 65 toward the return path. As a result, the work on the electric cutting machine 10 can be continued after the blade 72 is automatically returned to the initial position.

When the trigger 30 is released while the lifter 65 is moving forward from the initial position to the reverse position, the control unit 100 reversely drives the motor 50 so as to move the lifter 65 backward. As a result, the blade 72 can be automatically returned to the initial position when the cutting of the workpiece W is stopped or interrupted.

The electric cutting machine 10 also has a guide mechanism 80 that guides the forward and backward movement of the blade 72, and restricts the blade 72 from rotating about the forward and backward direction (moving direction of the lifter 65). In the electric cutting machine 10, the rotational force is transmitted by screwing the drive shaft 63 and the lifter 65 together. Therefore, when the motor 50 is rotationally driven, the rotational force about the longitudinal direction is also transmitted to the lifter 65. However, the guide mechanism 80 can prevent the blade 72 (lifter 65) from rotating. In particular, since the guide mechanism 80 (guide portion 81B) also functions as a portion that covers the blade 72, the rotation of the blade 72 can be regulated by the blade 72 cover member. In addition, since the guide portion 81B guides (regulates rotation of) the blade 72 at a position separated in the vertical direction (radial direction) from the lifter 65, the force transmitted from the blade 72 about to rotate to the guide portion 81B is reduced. can do. By operating the guide mechanism 80, the orientation of the blade 72 viewed from the front-rear direction is changed. Specifically, the direction of the blade 72 viewed from the front-rear direction is changed by rotating the guide plate 81 of the guide mechanism 80 around the axis of the inner guide 45 by the operator's manual operation. Therefore, the orientation of the blade 72 with respect to the workpiece W arranged on the front side of the blade 72 can be changed. Accordingly, the orientation of the blade 72 with respect to the workpiece W can be changed without changing the orientation of the entire electric cutting machine 10 with respect to the workpiece W. In particular, since the blade portion 72A of the blade 72 is composed of a single edge, the finished surface of the workpiece W can be easily changed by operating the guide mechanism 80. FIG. Therefore, the workability of the electric cutting machine 10 can be improved.

Further, in the feed screw mechanism 60 , a lifter 65 is screw-engaged with a drive shaft 63 whose axial direction is the front-rear direction, and the blade 72 is fixed to the lifter 65 . Further, the guide mechanism 80 has a guide plate 81 that guides the movement of the blade 72 in the front-rear direction, and the guide plate 81 is rotatably connected to the lifter housing 22 with the front-rear direction as its axial direction. When the guide mechanism 80 is actuated, the guide mechanism 80 rotates around the axis of the drive shaft 63 . As a result, the lifter 65 and the blade 72 can be rotated around the axis of the drive shaft 63 by the guide plate 81 to change the orientation of the blade 72 .

Also, the lifter 65 is supported by the inner guide 45 so as to be able to reciprocate. That is, the inner guide 45 allows movement in the front-rear direction while restricting the movement of the lifter 65 in the vertical and horizontal directions. By doing so, it is possible to improve the accuracy of the reciprocating motion of the lifter 65, and it is possible to perform cutting with high accuracy. Further, the lifter 65 is supported by the inner guide 45 on the front side and by the male screw 63A (the drive shaft 63) on the rear side. Therefore, the lifter 65 is operably supported at two locations spaced apart in the front-rear direction, thereby preventing the lifter 65 from tilting. Therefore, cutting accuracy can be improved. Furthermore, by suppressing the inclination of the lifter 65, it is possible to suppress the occurrence of troubles in the screw engagement with the drive shaft 63. Further, the guide mechanism 80 includes 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 whose axial direction is the front-rear direction, and supports the lifter 65 so as to be movable in the front-rear direction. As a result, the lifter 65 can be movably supported by utilizing the inner guide 45 which is the rotating shaft of the guide plate 81 . Therefore, it is possible to suppress an increase in the number of parts of the electric cutting machine 10 and contribute to downsizing of the electric cutting machine 10 . In addition, as described above, the lifter body 66 is supported so as to be movable in directions (up, down, left, and right) intersecting the front-rear direction, which is the direction driven by the motor 50 . In other words, between the lifter 65 (lifter main body 66) and the lifter guide 45, there is a slight gap in the radial direction. Although slight dimensional variations occur during manufacturing, providing a radial gap between the lifter 65 and the lifter guide 45 makes it possible to appropriately cope with such variations. That is, it becomes easy to manufacture. However, if a gap is formed between the lifter 65 and the lifter guide 45, the lifter 65 may rattle inside the lifter guide 45. An O-ring 46 (elastic body) is used to absorb rattling movements. Further, in the present embodiment, the transmission gear 61 is movably supported in a direction (front-rear direction) intersecting the direction in which the transmission gear 61 is driven by the motor 50 (rotational direction centered on the front-rear direction, vertical and horizontal directions). It is By doing so, it is possible to cope with the above-described variations in component dimensions due to manufacturing, and to facilitate manufacturing. That is, in the present invention, the housing 20 (the spacer 26, the lifter housing 22) is arranged so that the parts that receive the power of the motor 50 and transmit the power to the blade 72 can move in a direction that intersects the direction in which the motor 50 drives. ), it is possible to realize a work machine that is easy to manufacture. Cost reduction can also be achieved by facilitating manufacturing.

Further, the lifter housing 22 is 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 abutting portions 94B of the stoppers 94. As shown in FIG. That is, the orientation of the blade 72 with respect to the workpiece W is determined. Specifically, in the present embodiment, the orientation of the blade 72 when the guide mechanism 80 is arranged at the first position and the orientation of the blade 72 when the guide mechanism 80 is arranged at the second position are They are shifted by 180 degrees in the direction of rotation of the guide mechanism 80 . This allows the operator to easily determine the position of the guide mechanism 80 and change the orientation of the blade 72 .

Also, the operating range of the guide mechanism 80 is defined by the pair of stoppers 94 . Specifically, the rotation angle range of the guide mechanism 80 is regulated to 180 degrees by the pair of stoppers 94 . As a result, the initial stop position of the lifter 65 can be prevented from being excessively deviated before and after the guide mechanism 80 is actuated.

A wave washer 92 is provided between the lifter housing 22 and the guide plate 81 . A wave washer 92 restricts the relative rotation of the guide mechanism 80 with respect to the housing 20 when the motor 50 is driven. Further, when the operator applies an operating force (rotational force) equal to or greater than a predetermined value to the guide mechanism 80 (guide plate 81), the guide mechanism 80 is permitted to rotate relative to the housing 20. FIG. As a result, with a simple configuration, it is possible to restrict the relative rotation of the guide mechanism 80 with respect to the housing 20 when the motor 50 is driven, and allow the manual operation of the guide mechanism 80 by the operator.

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

Further, for example, in the feed screw mechanism 60, instead of the lifter detection switch 68, a contact or non-contact linear sensor may be provided, and the position of the lifter 65 may be detected by the linear sensor. Even in this case, the control unit 100 can detect the initial position and the reverse position of the lifter 65 . Alternatively, the load on the motor 50 may be increased when the lifter 65 is positioned at the initial position, and the initial position may be detected by detecting the current increase under load. In this case, the reverse position may be detected as described above by setting the timing at which the load on the motor 50 is reduced (the timing at which the current value is decreased) during forward rotation as the initial position. In this way, the position detection section in the present invention can be configured using various means as well as mechanical/electronic switches.

Further, in the present embodiment, the transmission gear 61 is meshed 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 as to be integrally rotatable. Alternatively, for example, the motor 50 may be changed to a stepping motor with a feed screw, and the lifter 65 may be screw-fitted to the feed screw. In this case, the position detection accuracy of the lifter 65 in the control section 100 can be further improved. Furthermore, since the transmission gear 61 can be omitted, it is possible to contribute to miniaturization of the electric cutting machine 10 .

Further, in this embodiment, the rotation range of the guide mechanism 80 is restricted by a pair of stoppers 94 so that the direction of the blade 72 can be easily changed. In other words, the orientation of the blade 72 is changed by positioning the guide mechanism 80 relative to the housing 20 by arranging the guide mechanism 80 at the first position or the second position where the guide mechanism 80 contacts the stopper 94 . That is, although the guide mechanism 80 for changing the orientation of the blade 72 is set at two positions, the guide mechanism 80 may be positioned at three positions. In other words, the guide mechanism 80 may be positioned at an intermediate position between the first position and the second position so that the guide mechanism 80 can be held at the intermediate position. This configuration will be described below with reference to FIGS. 9 and 10. FIG.

9 and 10, in this configuration, instead of the wave washer 92, a fixed washer 110 as a movement restricting member is arranged between the guide plate 81 and the lifter housing 22 (fixed plate 41). ing. The fixed washer 110 is formed substantially in the shape of a frame plate whose plate thickness direction is the front-rear direction. The fixed washer 110 has a pair of upper and lower fixed pieces 112, and the fixed pieces 112 extend in the left-right direction.

A pair of left and right engaging projections 114 are formed on the fixed piece 112, and the engaging projections 114 are bent in a substantially U-shape that protrudes forward and opens rearward. The fixed washer 110 is disposed between the curved portion 81A of the guide plate 81 and the lifter housing 22 with the inner guide 45 (not shown in FIG. 9) inserted through the fixed washer 110. As shown in FIG. A pair of left and right engaging projections 114 sandwich the guide portion 81B and the connecting portion 81C of the guide plate 81 from the outside in the left-right direction. As a result, the fixed washer 110 is attached to the guide plate 81 so as to rotate integrally therewith.

A locking projection 116 as a locking portion is formed at the center of the fixing piece 112 in the left-right direction, and the locking projection 116 projects rearward and is bent in a generally arcuate shape that opens forward. .

On the other hand, the front end of the fixing plate 41 is formed with a locking recess 41B as a locked portion on the front side of the bolt BL2. The engaging recess 41B is formed in a generally arcuate shape that opens forward when viewed from the left-right direction.

At the first position or the second position of the guide mechanism 80, the locking protrusion 116 is arranged at a position spaced apart from the locking recess 41B by 90 degrees in the rotational direction of the guide mechanism 80 (see FIG. 9 ( A) shows the second position of the guide mechanism 80). When the guide mechanism 80 is positioned at an intermediate position between the first position and the second position, the locking projection 116 is fitted into the locking recess 41B, and the locking projection 116 and the locking recess 41B are engaged with each other. 41B are engaged in the rotational direction (see FIG. 9(B)). Thereby, the locking projection 116 is indirectly locked to the housing 20 via the fixing plate 41, and the rotation of the guide mechanism 80 is preferably suppressed. Also, at this time, the operator is provided with a sense of moderation (a click feeling). As described above, it is possible to limit the rotation of the guide mechanism 80 by setting three positions for positioning 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) away from the lifter 65 (rotational center), so the blade 72 itself may rotate. In this case, the rotation of the blade 72 can be suppressed with a small force, and when the operator tries to rotate the blade 72 via the guide mechanism 80, the blade 72 can be rotated with a small force. Although the locking recess 41B is formed in the fixing plate 41 in the above example, the locking recess 41B may be formed in the housing 20 to directly lock the locking projection 116 to the housing 20. FIG.

Further, in the present embodiment, when the drive shaft 63 and the lifter 65 are screwed together to reciprocate the blade 72 in the front-rear direction, a male screw portion (drive shaft 63) is on the drive side (motor 50 side), and the female screw portion (lifter 65) is on the driven side (blade 72 side). If the female screw is on the drive side and the male screw is on the driven side, the female screw will cover the reciprocating male screw. However, in this embodiment, the lifter 65 on the driven side can be pivotally supported with a simple structure. As a result, cost reduction can also be achieved.

Further, by providing the drive shaft 63 with the collar portion 63B, the rearward movement of the drive shaft 63 is indirectly restricted by the lifter housing 22 (bearing support portion 22B). In other words, rearward forces transmitted to drive shaft 63 are received by shaft bearing 64 and lifter housing 22 . By doing so, even if a rearward reaction force is transmitted to the drive shaft 63 when the blade 72 cuts, the transmission of this reaction force to the transmission gear 61 can be suppressed. As a result, the durability required for the transmission gear 61 and the gear bearing 62 can be reduced, so that, for example, inexpensive or small-sized devices can be adopted.

Further, in the present embodiment, when a load is applied to the blade 72 (when cutting the workpiece), a forward thrust force is applied to the transmission gear 61 (gear portion 61B) due to the meshing action with the pinion gear 51A. The gear portion 61B is formed as follows. By doing so, it is possible to suppress the rearward biasing force from being transmitted to the gear bearing 62 via the transmission gear 61 at the time of cutting. In the opposite case, that is, when a load is applied to the blade 72 and a rearward thrust force is applied to the transmission gear 61, the inner ring of the gear bearing 62 is in contact with the transmission gear 61 on the front side. A rearward biasing force is generated on the inner ring. This biasing force acts to shift the position of the inner ring in the front-rear direction with respect to the position of the outer ring, which leads to shortening of the life of the gear bearing 62 . In the case of this embodiment, such problems can be suppressed. That is, the durability required for the gear bearing 62 can be reduced, and the gear bearing 62 can be made low-cost or compact.

At least part of the gear bearing 62 is located at the same position as the motor bearing 55 in the longitudinal direction. In other words, at least part of the gear bearing 62 is positioned to overlap the motor bearing 55 when viewed in the radial direction (vertical direction). As a result, the length in the front-rear direction can be shortened. Further, in the present embodiment, as described above, the gear bearing 62 can be made small, so that the center position of the motor bearing 55 and the center position of the gear bearing 62 in the direction crossing the front-rear direction (vertical direction) can be brought close to each other. can. As a result, the axial center of the drive shaft 63 or the lifter 65 extending in the front-rear direction can be brought close to the drive shaft 51 extending in the front-rear direction in a direction intersecting the front-rear direction (vertical direction). That is, the drive shaft 63 or the lifter 65 can be brought closer to the drive shaft 51 in the vertical direction. This makes it possible to reduce the size in the vertical direction.

Further, in the present embodiment, at the first position or the second position of the guide mechanism 80, the guide plate 81 contacts the contact portion 94B of the stopper 94 to limit the rotation of the guide mechanism 80. A magnet may be embedded in the portion 94B and the guide plate 81 may be made of a steel plate so that the contact state between the guide plate 81 and the stopper 94 is maintained by the magnetic force of the magnet. As a result, the guide mechanism 80 can be favorably held at the first position or the second position.

Although the present embodiment is configured by combining a plurality of inventions described in each paragraph and each segment described in the above (action and effect), the work machine may be configured to apply only one invention. . As described above, the features described one by one are effective by themselves, that is, only one of the multiple inventions described in this embodiment may be employed. In particular, in the present embodiment, a work machine with good workability is realized by applying both the invention of control and the invention of machine configuration, but only one of them may be applied.

DESCRIPTION OF SYMBOLS 10... Electric cutting machine (work machine), 20... Housing, 30... Trigger (operation part), 50... Motor, 65... Lifter (moving member), 68... Lifter detection switch (position detection part), 72... Blade (cutting blade), 83... head plate (supporting portion), 83A... head concave portion (concave portion), 100... control portion, W... workpiece

Claims

a housing;
a motor housed in the housing;
a control unit that controls the motor;
an operation unit that operates the motor by being turned on;
a cutting blade moved between an initial position and a reversed position along a first direction by the motor;
a support for supporting the workpiece,
A work machine that cuts a workpiece with the cutting blade and the support,
When the cutting blade is in the initial position, the supporting portion and the cutting blade do not overlap when viewed in a second direction perpendicular to the first direction,
When the operation unit is turned on while the cutting blade is at the initial position, the control unit rotates the motor forward to move the cutting blade closer to the support unit, and rotates the operation unit. is configured to stop or reversely rotate the motor in a state where the support portion and the cutting blade are at least partially overlapped when viewed in the second direction when the portion is turned on.
The cutting blade has a plate shape extending in the first direction and the second direction,
The control section stops the motor or reverses the motor at a position where the support section and the cutting blade overlap when viewed in a third direction perpendicular to both the first direction and the second direction. The work machine according to claim 1, which is configured as follows.
The support portion is provided with a recess in which a portion of the workpiece can be positioned,
The working machine according to claim 2, wherein the control section is configured to stop the motor or reverse the motor at a position where the recess and the cutting blade overlap when viewed in the third direction.
a housing;
a motor housed in the housing;
a control unit that controls the motor;
an operation unit that operates the motor when operated;
an output unit rotationally driven by the motor;
a moving member that is screwed to the output unit and operates in one direction when the motor rotates forward and operates in the other direction opposite to the one direction when the motor rotates in the reverse direction;
a cutting blade configured to operate integrally with the moving member;
with
The control section is configured to stop the motor while the output section and the moving member are kept screwed together when the moving member is moved in one direction or the other direction.
a position detection unit that detects the position of the moving member;
The working machine according to claim 4, wherein the control section drives and controls the motor based on the detection result of the position detection section.
a housing;
a motor housed in the housing;
an operation unit provided in the housing for operating the motor when operated;
a moving member that is movably accommodated in the housing and reciprocates between an initial position and a reverse position by driving force of the motor;
a blade attached to the moving member outside the housing and approaching a workpiece by moving the moving member from the initial position to the reversal position toward the outward path;
a position detection unit that detects the position of the moving member;
a control unit that drives and controls the motor based on the detection result of the position detection unit;
machine with
The position detection unit is
an initial position detection unit that detects the initial position of the moving member;
a reversal position detection unit that detects the reversal position of the moving member;
is composed of
7. The control unit detects the initial position of the moving member based on the detection result of the initial position detection unit, and detects the reverse position of the moving member based on the detection result of the reverse position detection unit. The working machine described in .
The position detection unit is configured to detect the initial position of the moving member,
The control unit detects the initial position of the moving member based on the detection signal of the position detecting unit, and detects the reverse position of the moving member based on the number of revolutions of the motor from the initial position. Item 6. The working machine according to Item 6.
The position detection unit is a switch that is switched from off to on by being pressed by the moving member when the moving member moves from the reverse position to the initial position on the return path side,
9. The working machine according to claim 8, wherein the control unit starts measuring the number of revolutions of the motor, starting from the point in time when the position detection unit switches from on to off.
10. The controller according to any one of claims 7 to 9, wherein after a predetermined time has passed since the reverse position of the moving member was detected, the control unit drives and controls the motor so as to move the moving member toward the return path. Working machine described in paragraph.
8. When the control unit does not detect the initial position of the moving member when the operation of the operating unit is started, the control unit drives and controls the motor so as to move the moving member toward the return path. The working machine according to any one of claims 1 to 10.
When the operation of the operation unit is released while the moving member is moving from the initial position to the reversing position in the forward direction, the control unit drives and controls the motor so as to move the moving member in the backward direction. The work machine according to any one of claims 6 to 11.
The working machine according to any one of claims 5 to 12, wherein the position detection section is provided at a lateral position of the moving member.
14. The housing according to claim 13, wherein the housing has a first housing that accommodates the moving member, a second housing that accommodates the motor and the controller, and a third housing that accommodates at least part of the position detector. working machine.
The working machine according to claim 14, wherein the third housing is supported by the first housing or the second housing.