Work machine

Abstract

To improve operability.SOLUTION: In a miter saw 10, a fixing mechanism 50 includes a lever 64 and a bearing 68 that regulates rotation of a support column 42 to one side in a rotating direction at a right-angle position of a support column 42. By rotating the lever 64 about an axis AL1, the fixing mechanism 50 is switched between a fixed state and an unfixed state. Further, by performing a movement operation of moving the lever 64 toward a rear side along the axis AL1, a front-rear position of a lever unit 60 (the bearing 68) is switched from a first position to a second position, so that the restriction of rotation of the support column 42 toward the one side in the rotating direction by the bearing 68 is released. This eliminates the need for an operator to operate separate operating-portions when a head portion 32 is changed from the right-angle position to a position inclined to a right side with respect to a turntable 24. Therefore, it is possible to improve the operability when changing the position of the head portion 32 with respect to the turntable 24.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] The bench cutter (working machine) described in Patent Document 1 listed below allows the attitude (tilt angle) of a cutting tool unit (circular saw blade) relative to a base to be changed. Specifically, the bench cutter has a clamp lever for releasing the fixed state of a holder supporting the cutting tool unit from the base, and a stopper pin for restricting the tilt of the holder at a predetermined restricted position. For example, when tilting the cutting tool unit to an inclined position beyond the restricted position, the stopper pin is pulled rearward to release the restriction imposed by the stopper pin, and then the clamp lever is rotated to release the fixed state of the holder from the base. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-149039 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned bench cutters have room for improvement in the following respects. Specifically, as described above, when changing the cutting tool unit to a tilted position beyond the restricted position, it is necessary to operate two operating parts: the clamp lever and the stopper pin. This requires the operator to operate two operating parts located in different positions, which may result in poor operability.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a work machine that can improve operability. [Means for solving the problem]

[0006] One or more embodiments of the present invention are a work machine comprising: a base having an upper surface extending in the front-to-back and left-to-right directions on which a workpiece is placed; a cutting unit configured to be swingable in the up-and-down direction; a circular saw blade provided on the cutting unit; a support unit rotatably connected to the base with the front-to-back direction as its axial direction and supporting the cutting unit; an operating unit operated by an operator; and a regulating unit that regulates rotation of the support unit at a predetermined rotation position of the support unit; and a fixing mechanism that fixes the support unit to the base; wherein, by a first operation of the operating unit, the fixing mechanism switches between a fixed state in which the support unit is fixed to the base or a fixed-release state in which the fixation to the support unit is released, and by a second operation of the operating unit, the rotation restriction on the support unit by the regulating unit is released.

[0007] One or more embodiments of the present invention are directed to a work machine in which the first operation is a rotation operation that rotates the operating unit around a predetermined axis, and the second operation is a movement operation that moves the operating unit along the predetermined axis.

[0008] In one or more embodiments of the present invention, the fixing mechanism has an engagement portion that engages with the regulating portion to regulate the rotation of the support portion at the predetermined rotation position, the regulating portion is connected to the operating portion so that it cannot move relative to the operating portion, and during the second operation, the regulating portion moves together with the operating portion, thereby disengaging the regulating portion from the engagement portion.

[0009] In one or more embodiments of the present invention, the fixing mechanism has a fixing part, and when the fixing part is rotated around the specified axis, the fixing mechanism switches between the fixed state and the unlocked state, and the operating part is connected to the fixing part so as to be rotatable integrally with the fixing part and so as to be movable relatively along the specified axis.

[0010] One or more embodiments of the present invention are a work machine in which the fixing portion is provided on one of the support portion and the base, and the engagement portion is provided on the other of the support portion and the base.

[0011] In one or more embodiments of the present invention, the operating unit is configured to be movable between a first position in which the regulating unit and the engaging unit are engaged and a second position in which the engagement between the regulating unit and the engaging unit is released, and the fixing mechanism has a biasing member that biases the operating unit along the specified axis, and the operating unit is biased toward the first position by the biasing member.

[0012] In one or more embodiments of the present invention, the operating unit is a work machine having a single gripping portion that is held by an operator.

[0013] One or more embodiments of the present invention are directed to a work machine in which the restricting portion and the operating portion are disposed on the rear side of the base.

[0014] One or more embodiments of the present invention are a work machine in which the operating part is operably exposed at a front end of the base.

[0015] One or more embodiments of the present invention are a working machine including: a base having an upper surface extending in the front-to-back and left-to-right directions on which a workpiece is placed; a cutting unit configured to be able to swing up and down; a circular saw blade provided on the cutting unit; a support unit rotatably connected to the base, supporting the cutting unit, and moving relative to the base to change the posture of the circular saw blade; and a fixing mechanism that fixes the support unit to the base, wherein the fixing mechanism includes an operating unit operated by an operator; the fixing unit extending along a predetermined axis and configured to move along the predetermined axis by a first operation on the operating unit to switch between a fixed state in which the support unit is fixed to the base and a released state in which the support unit is released from the base; and a regulating unit configured to operate coaxially with the fixing unit and that regulates rotation of the support unit at a predetermined rotation position of the support unit, wherein a second operation on the operating unit in the released state moves the regulating unit along the predetermined axis independently of the fixing unit to release the rotation-regulated state of the support unit at the predetermined rotation position.

[0016] One or more embodiments of the present invention are directed to a work machine in which one of the fixing portion and the restricting portion is configured as a shaft member, and the other has an annular structure that covers an outer periphery of the other.

[0017] In one or more embodiments of the present invention, the first operation is a rotational operation around the specified axis, the second operation is an operation in a direction along the specified axis, the fixing part and the regulating part move together during the first operation, and the regulating part moves relative to the fixing part during the second operation. [Effects of the Invention]

[0018] According to one or more embodiments of the present invention, operability can be improved. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a side view showing a bench circular saw according to a first embodiment, as viewed from the left side. [Figure 2] 2 is a rear view of the bench circular saw shown in FIG. 1 as seen from the rear side. [Figure 3] 3 is a cross-sectional view (cross-sectional view taken along line 3-3 in FIG. 2) showing the periphery of the fixing mechanism shown in FIG. 2 as seen from the left side. [Figure 4] 4 is a cross-sectional view showing a state in which the lever shown in FIG. 3 is pulled rearward to move the lever unit to a second position. FIG. [Figure 5] 5 is a cross-sectional view (cross-sectional view taken along line 5-5 in FIG. 3) seen from the front side, showing the positional relationship between the bevel plate and the bearing shown in FIG. 3. [Figure 6] FIG. 10 is a side view showing the lower part of the bench circular saw according to the second embodiment, as viewed from the left side. [Figure 7] 7 is a rear view showing the periphery of the lower end of the support column shown in FIG. 6, as seen from the rear side. [Figure 8] 8 is a cross-sectional view (cross-sectional view taken along line 8-8 in FIG. 7) showing the periphery of the fixing mechanism shown in FIG. 7 as seen from the left side. [Figure 9]9 is a cross-sectional view showing a state in which the lever shown in FIG. 8 is pushed rearward to move the lever unit to a second position. DETAILED DESCRIPTION OF THE INVENTION

[0020] (First embodiment) 1 to 5, a description will be given of a bench circular saw 10 as a work machine according to a first embodiment. Note that the arrows UP, FR, and LH shown as appropriate in the drawings respectively indicate the upper side, front side, and left side of the bench circular saw 10. In the following description, when the up-down, front-rear, and left-right directions are used, they refer to the up-down, front-rear, and left-right directions of the bench circular saw 10 unless otherwise specified.

[0021] 1 and 2, the bench circular saw 10 is a device for cutting a workpiece. The bench circular saw 10 includes a base 20 and a circular saw body 30.

[0022] (About Base 20) The base 20 constitutes the lower end of the bench circular saw 10 and is configured as a platform on which the workpiece is placed. The base 20 has a base main body 22 and a turntable 24. The base main body 22 is formed in a generally flat plate shape with the thickness direction extending in the vertical direction, and a recess 22A that is open upward is formed in the center of the base main body 22 in the horizontal direction.

[0023] The turntable 24 extends in the front-to-rear direction. A central portion of the turntable 24 in the front-to-rear direction is housed in a recess 22A of the base main body 22 and is rotatably supported by the base main body 22 with the vertical direction as its axial direction. The front and rear ends of the turntable 24 protrude outward in the front-to-rear direction relative to the base main body 22. The upper surface of the turntable 24 serves as a mounting surface 24A, which is disposed along a plane perpendicular to the vertical direction and is disposed flush with the upper surface of the base main body 22.

[0024] (Regarding the circular saw body 30) The circular saw body 30 includes a head portion 32 as a cutting portion and a tilting mechanism 40, and the head portion 32 is connected to the base 20 by the tilting mechanism 40. Below, the head portion 32 will be described first, and then the tilting mechanism 40 will be described.

[0025] (Regarding the head part 32) The head unit 32 is provided above the base 20 and is supported by a tilting mechanism 40 so as to be swingable up and down with the left-right direction as its axial direction. A motor housing 32A protruding to the left is provided at the upper end of the head unit 32, and a motor 34 is housed within the motor housing 32A. A handle unit 32B is formed at the front end of the head unit 32, and an operable trigger 36 is provided on the handle unit 32B. A switch (not shown) is provided within the handle unit 32B, and the switch and motor 34 are electrically connected to a controller (not shown). When the trigger 36 is operated, the switch is turned on and the motor 34 is driven by the controller.

[0026] A circular saw blade 38 is provided on the head portion 32. The circular saw blade 38 is formed in a generally circular plate shape with its thickness direction in the left-right direction. The center of the circular saw blade 38 is fixed to a transmission mechanism (not shown) provided on the head portion 32. The transmission mechanism is configured as a mechanical part that transmits the driving force of the motor 34 to the circular saw blade 38 and rotates the circular saw blade 38 about its own axis.

[0027] (Regarding the tilt mechanism 40) The tilt mechanism 40 includes a support column 42 as a support portion, and a fixing mechanism 50 .

[0028] (Regarding support column 42) The support pillar 42 extends in the vertical direction, and the lower end of the support pillar 42 is connected to the rear end of the turntable 24. The support pillar 42 inclines to the right as it extends upward, and the upper end of the support pillar 42 is positioned offset to the right with respect to the lower end of the support pillar 42. A slide mechanism 44 is provided at the upper end of the support pillar 42, and the slide mechanism 44 extends forward from the upper end of the support pillar 42. A hinge base 46 is connected to the slide mechanism 44 so as to be slidable in the front-rear direction, and the rear end of the head unit 32 is connected to the hinge base 46 so as to be swingable with the left-right direction as the axial direction. As described above, the support pillar 42 is configured as a member that supports the head unit 32.

[0029] The lower end of the support pillar 42 is rotatably connected to the rear end of the turntable 24 by a connecting shaft 48 (see FIG. 2) whose axial direction is the front-to-rear direction. Thus, by rotating the support pillar 42 relative to the turntable 24 in one direction (the direction of arrow A in FIGS. 2 and 5, i.e., the right side) or the other direction (the direction of arrow B in FIGS. 2 and 5, i.e., the left side), the attitude of the head unit 32 relative to the turntable 24 (more specifically, the angle of the circular saw blade 38 relative to the mounting surface 24A) can be changed. In this embodiment, the position of the support pillar 42 (head unit 32) shown in FIGS. 1 and 2 is a right-angle position, which is a predetermined rotation position. At the right-angle position, the angle of the circular saw blade 38 relative to the mounting surface 24A is 90 degrees.

[0030] (Regarding the fixing mechanism 50) The fixing mechanism 50 is a mechanism for fixing the support column 42 to the turntable 24. As shown in FIGS. 2 to 5, the fixing mechanism 50 is configured to include a fixed shaft 52 as a fixing portion, a bevel plate 58 as an engaging portion, and a lever unit 60.

[0031] The fixed shaft 52 is formed in a stepped cylindrical shape with its axial direction extending in the front-rear direction, and is disposed above the connecting shaft 48. A threaded portion 52A is provided at the front end of the fixed shaft 52, and a male thread is formed on the outer periphery of the threaded portion 52A. The threaded portion 52A is threadedly engaged with a female threaded portion 42A formed at the lower end of the support pillar 42, and the rear portion of the fixed shaft 52 protrudes rearward from the support pillar 42. A flange portion 52B protruding radially outward is formed at the middle portion of the fixed shaft 52 in the front-rear direction, and a washer 56 fitted onto the fixed shaft 52 is disposed in front of the flange portion 52B. When the fixing mechanism 50 is in the fixed state, the flange portion 52B (washer 56) of the fixed shaft 52 and the lower end of the support pillar 42 sandwich the rear end of the turntable 24 from both front-rear directions, thereby fixing the support pillar 42 to the turntable 24.

[0032] The fixed shaft 52 is provided with a locking screw 54. The locking screw 54 is a shoulder screw with its axial direction aligned in the front-to-rear direction. The diameter of the locking screw 54 is set smaller than the diameter of the fixed shaft 52. The locking screw 54 is threadedly engaged with the rear end of the fixed shaft 52, protrudes rearward from the fixed shaft 52, and is arranged coaxially with the fixed shaft 52. In other words, the axis of the locking screw 54 coincides with the axis AL1, which is the predetermined axis of the fixed shaft 52. A connecting hole 52C is formed in the rear end of the fixed shaft 52 at the center in the up-down direction, penetrating in the left-to-right direction. The connecting hole 52C is formed in an elongated hole shape with its longitudinal direction aligned in the front-to-rear direction when viewed from the left-to-right direction.

[0033] The bevel plate 58 is formed in a generally arc-shaped plate shape with its thickness in the front-to-rear direction and extending in the circumferential direction of the connecting shaft 48. The bevel plate 58 is disposed above the connecting shaft 48 and fixed to the rear end of the turntable 24. The rear end of the fixed shaft 52 is located radially outward of the connecting shaft 48 with respect to the bevel plate 58 (see FIG. 5).

[0034] A notch 58A is formed on the left side of the outer periphery on the upper side of bevel plate 58, and notch 58A is disposed at a position one step lower radially inward than the outer periphery on the right side of bevel plate 58. As a result, a step 58B (see FIG. 5) is formed in the left-right intermediate portion of the outer periphery on the upper side of bevel plate 58.

[0035] The lever unit 60 includes a sleeve 62, a lever 64 as an operating part, a bearing 68 as a restricting part, and a return spring 70 as a biasing member. The sleeve 62 is formed in a generally cylindrical shape with the front-to-rear direction as its axial direction. Except for the front end part (a part into which a bearing 68, which will be described later, is press-fitted), the outer shape of the sleeve 62 is formed in a regular hexagon, and the outer shape of the front end part of the sleeve 62 is formed in a circular shape. The sleeve 62 is fitted onto the rear end part of the fixed shaft 52 and is supported by the fixed shaft 52 so as to be movable in the front-to-rear direction.

[0036] The lever 64 is configured to include a connecting tube portion 64A and a lever portion 64B serving as a grip portion. The connecting tube portion 64A is formed in a substantially cylindrical shape with its axial direction extending in the front-to-rear direction, and the lever portion 64B extends radially outward (downward) from the connecting tube portion 64A. A partition wall 64C is formed inside the connecting tube portion 64A at a middle portion in the front-to-rear direction, and the interior of the connecting tube portion 64A is divided into front and rear sections by the partition wall 64C. An insertion hole 64D is formed through the partition wall 64C in the front-to-rear direction.

[0037] The inner periphery of the front part of the lever 64 is formed with a hexagonal cross section corresponding to the outer shape of the sleeve 62. The sleeve 62 is inserted into the front part of the connecting cylinder part 64A with the front end part of the sleeve 62 protruding forward from the connecting cylinder part 64A. This connects the lever 64 to the sleeve 62 so that they can rotate together. A connecting pin 66 is provided inside the sleeve 62. The connecting pin 66 is arranged with its axial direction in the left-right direction, and both longitudinal ends of the connecting pin 66 are fixed to the sleeve 62 and the connecting cylinder part 64A. This connects the lever 64 to the sleeve 62 so that they cannot move relative to each other in the front-rear direction.

[0038] The diameter of the connecting pin 66 is set slightly smaller than the width dimension of the connecting hole 52C of the fixed shaft 52, and the connecting pin 66 is inserted into the connecting hole 52C so as to be movable in the front-rear direction. This connects the lever unit 60 to the fixed shaft 52 so as to be rotatable integrally with the fixed shaft 52 and so as to be movable relatively in the front-rear direction. Therefore, by rotating the lever 64 around the axis AL1 (first operation), the fixing mechanism 50 is switched between a fixed state and an unlocked state. Furthermore, by moving the lever 64 relatively in the front-rear direction with respect to the fixed shaft 52, the front-rear position of the lever unit 60 is switched between a first position (position shown in FIG. 3) and a second position (position shown in FIG. 4). Furthermore, when the lever unit 60 is connected to the fixed shaft 52, the front end of the locking screw 54 is inserted through the insertion hole 64D of the lever 64, and the locking screw 54 is disposed in the rear portion of the connecting tubular portion 64A.

[0039] The bearing 68 is a ball bearing. The bearing 68 is arranged coaxially with the fixed shaft 52 and is fixed to the front end of the sleeve 62 by press fitting. This connects the bearing 68 to the lever 64 so that it cannot move relative to the lever 64.

[0040] The return spring 70 is a compression coil spring that is fitted onto the locking screw 54 of the fixed shaft 52. The front end of the return spring 70 is engaged with the partition wall 64C of the lever 64, and the rear end of the return spring 70 is engaged with the head of the locking screw 54, so that the return spring 70 biases the lever 64 forward (towards the first position).

[0041] Here, when the lever unit 60 is in the first position, the connecting pin 66 is disposed at the front end of the connecting hole 52C, and the sleeve 62 is disposed adjacent to the rear side of the flange portion 52B of the fixed shaft 52. This restricts the lever unit 60 from moving forward relative to the fixed shaft 52. Furthermore, when the lever unit 60 is in the first position, the bearing 68 and the front end portions of the sleeve 62 are disposed at positions overlapping with the bevel plate 58 in the front-to-rear direction.

[0042] Here, when the head portion 32 (support column 42) is in the perpendicular position, as viewed from the rear, the bearing 68 is disposed adjacent to the radially outer side (upper side) of the notch 58A of the bevel plate 58, and the step portion 58B of the bevel plate 58 is disposed adjacent to the bearing 68 on one side in the rotation direction of the support column 42 (see FIG. 5). As a result, when the fixing mechanism 50 is in the unlocked state, by placing the lever unit 60 in the first position, the step portion 58B functions as a stopper, restricting rotation of the support column 42 in one direction. When the lever unit 60 is in the first position, the fixing mechanism 50 is in a restricted state in which rotation of the support column 42 in one direction is restricted.

[0043] On the other hand, when the lever unit 60 is in the second position, the lever 64 (bearing 68) moves rearward relative to the fixed shaft 52, and the connecting pin 66 is positioned at the rear end of the connecting hole 52C. Also, when the lever unit 60 is in the second position, the bearing 68 and sleeve 62 are positioned rearward of the bevel plate 58. Therefore, when the fixing mechanism 50 is in the unlocked state, a movement operation (second operation) is performed to move the lever 64 rearward against the biasing force of the return spring 70, thereby changing the position of the lever unit 60 (bearing 68) from the first position to the second position, thereby permitting rotation of the support column 42 in one direction. When the lever unit 60 is in the second position, the fixing mechanism 50 is in a release state that permits rotation of the support column 42 in one direction. The lever 64 (bearing 68) is operable coaxially with the fixed shaft 52. Specifically, the fixed shaft 52 is rotatable about an axis AL1, and the lever 64 (bearing 68) is rotatable about the axis AL1 and is movable axially on the axis AL1. The lever 64 (bearing 68) has a cylindrical (annular) structure that covers a portion of the fixed shaft 52, and the axis of the cylindrical (annular) structure is located on the axis AL1. The lever 64 (bearing 68) is configured to move on the outer surface of the fixed shaft 52.

[0044] (Action and effect) Next, the procedure for tilting the head unit 32, which is positioned at a right angle, relative to the turntable 24 will be described, along with the operation and effects of this embodiment.

[0045] When tilting the position of the head unit 32 from the perpendicular position, the fixing mechanism 50 is switched from the fixed state to the unlocked state. Specifically, the operator grasps the lever portion 64B of the lever 64 and rotates the lever 64 counterclockwise around the axis AL1 of the fixed shaft 52 as viewed from the rear. This switches the fixing mechanism 50 to the unlocked state, and the fixed state with respect to the support column 42 is released.

[0046] In this state, the lever unit 60 is positioned in the first position due to the biasing force of the return spring 70. Specifically, the bearing 68 is disposed adjacent to the notch 58A of the bevel plate 58 on the radially outer side, and the step 58B of the bevel plate 58 is disposed adjacent to one side (right side) of the bearing 68 in the rotation direction. As a result, when the support pillar 42 is rotated to the right, the bearing 68 engages with the bevel plate 58. Therefore, when the lever unit 60 is in the first position, rightward rotation of the support pillar 42 is restricted. On the other hand, as described above, the bearing 68 is disposed adjacent to the notch 58A of the bevel plate 58 on the radially outer side of the connecting shaft 48, and leftward rotation of the support pillar 42 is permitted. Therefore, by rotating the support pillar 42 to the desired position leftward and then rotating the lever 64 to switch the locking mechanism 50 to the locked state, the head unit 32 is changed to a position tilted leftward relative to the turntable 24.

[0047] On the other hand, when tilting the support column 42 to the right, the longitudinal position of the lever unit 60 is switched from the first position to the second position. Specifically, the lever 64 is pulled rearward against the biasing force of the return spring 70, causing the lever unit 60 to move rearward relative to the fixed shaft 52. When the lever unit 60 is in the second position, the bearing 68 is positioned rearward of the bevel plate 58. Therefore, even when the support column 42 is rotated to the right, the bearing 68 does not engage with the stepped portion 58B of the bevel plate 58, but is positioned rearward of the upper outer periphery of the bevel plate 58 (see the bearing 68 indicated by the two-dot chain line in FIG. 5). Therefore, by rotating the support column 42 to the desired position and then rotating the lever 64 to switch the fixing mechanism 50 to the fixed state, the head unit 32 is changed to a position tilted to the right with respect to the turntable 24.

[0048] When the lever unit 60 is in the second position, if the pull-out operation (movement operation) on the lever 64 is released after the support pillar 42 has rotated to the right, the lever unit 60 moves forward due to the biasing force of the return spring 70. Therefore, if the pull-out operation on the lever 64 is released at a position where the sleeve 62 overlaps the outer periphery of the bevel plate 58 as viewed from the front-to-rear direction, the sleeve 62 is held in contact with the outer periphery of the bevel plate 58. Furthermore, when the support pillar 42 is returned to the perpendicular position, the lever unit 60 moves forward relative to the fixed shaft 52 due to the biasing force of the return spring 70 at the perpendicular position of the support pillar 42, and the lever unit 60 returns to the first position.

[0049] As described above, in the bench circular saw 10, the fixing mechanism 50 includes the lever 64 operated by the operator and the bearing 68 that restricts rotation of the support column 42 in one direction of rotation at a position perpendicular to the support column 42. By rotating the lever 64 about the axis AL1, the fixing mechanism 50 is switched between a fixed state and an unlocked state. By moving the lever 64 rearward along the axis AL1, the front-to-rear position of the lever unit 60 (bearing 68) is switched from the first position to the second position, and the restriction on rotation by the bearing 68 in one direction of rotation relative to the support column 42 is released (switching from the restricted state to the unlocked state). That is, the lever portion 64B of the lever 64 functions as an operating part for switching the fixing mechanism 50 between the fixed state and the unlocked state, and also functions as an operating part for releasing the restriction on rotation by the bearing 68 in one direction of rotation relative to the support column 42. This eliminates the need for the operator to operate separate operating units when changing the head unit 32 from a perpendicular position to a position tilted to the right relative to the turntable 24. Therefore, the operability of changing the position of the head unit 32 relative to the turntable 24 is improved. In particular, the first operation for switching between the fixed and unlocked states and the second operation for switching between the restricted and unlocked states are different operations, making it easier to perform the intended task. In this embodiment, the first operation is a rotational operation and the second operation is an axial operation, but the combination of operation methods can be changed as appropriate. For example, the type of operation may include moving the operating unit (lever 64) in a direction intersecting the axis AL1 (up and down or left and right, etc.) or tilting (tilting about the left and right axis, etc.). Furthermore, a separate operating unit (e.g., a switch) for moving the restricting unit to release the rotation restriction may be provided in a position accessible when gripping and operating the lever unit 64B. This configuration also allows the operator to easily perform both the operation of fixing the support unit to the base and the operation of releasing the restriction by simply accessing a single operating unit, thereby eliminating complexity.

[0050] Furthermore, the fixing mechanism 50 has a bevel plate 58, and the bearing 68 engages with a stepped portion 58B of the bevel plate 58, thereby restricting rotation of the support column 42 in one direction of the rotation direction. Furthermore, the bearing 68 is connected to the lever 64 so as not to be able to move relative to it, and when the lever 64 is pulled rearward, the bearing 68 moves rearward relative to the bevel plate 58, thereby releasing the engagement between the bearing 68 and the bevel plate 58. As a result, the bearing 68 can be moved rearward in conjunction with the rearward movement of the lever 64, thereby releasing the engagement between the bearing 68 and the bevel plate 58.

[0051] The fixing mechanism 50 has a fixed shaft 52, and when the fixed shaft 52 is rotated about an axis AL1, the fixing mechanism 50 is switched between a fixed state and an unlocked state. A lever 64 is connected to the fixed shaft 52 so as to be rotatable integrally with the fixed shaft 52 and so as to be movable relative to the fixed shaft 52 in the front-to-rear direction. Thus, by rotating the lever 64, the fixing mechanism 50 can be switched between a fixed state and an unlocked state, and by moving the lever 64 rearward relative to the fixed shaft 52, the restriction on rotation of the support column 42 imposed by the bearing 68 can be released. That is, the operation for switching the fixing mechanism 50 between a fixed state and an unlocked state and the operation for releasing the restriction on rotation of the support column 42 imposed by the bearing 68 can be performed independently. This allows the operator to select the order of the rotation and movement (pulling-out) of the lever 64 when rotating the support column 42 to the right from the right-angle position. This further improves operability when rotating the support column 42 to the right from the right-angle position.

[0052] Furthermore, the fixed shaft 52 is threadedly engaged with the support column 42, and the bevel plate 58 is provided on the turntable 24. The bearing 68 engages with the bevel plate 58, restricting rotation of the support column 42 in one direction in the perpendicular position. Furthermore, the bearing 68 moves back and forth along the axis AL1, thereby switching between an engaged state and a disengaged state between the bearing 68 and the bevel plate 58. This allows the bearing 68 to be switched between an engaged state with the bevel plate 58 and a disengaged state with the bevel plate 58 with a simple configuration.

[0053] Furthermore, the fixing mechanism 50 has a return spring 70 that biases the lever 64 forward (towards the first position). As a result, when the lever unit 60 is in the second position, by releasing the movement operation of the lever 64, the biasing force of the return spring 70 can automatically return the lever unit 60 to the first position. Therefore, the operability of the lever 64 can be effectively improved.

[0054] Furthermore, the lever 64 has a single lever portion 64B that is gripped by the operator. That is, the lever 64 has only one portion that is gripped by the operator. Therefore, the operability of the lever 64 can be improved compared to a configuration in which the lever 64 has multiple grip portions. Furthermore, the lever 64 (bearing 68) can move coaxially with the fixed shaft 52, which makes it easy to consolidate the operating ranges of the bearing 68 and the fixed shaft 52, thereby enabling miniaturization. In particular, the lever 64 (bearing 68) has a cylindrical (annular) structure that covers a portion of the fixed shaft 52, and the axis of the cylindrical (annular) structure is located on the axis line AL1, which further consolidates the operating range. Furthermore, the lever 64 (bearing 68) is configured to move on the outer surface of the fixed shaft 52, which further consolidates the operating range. In addition, with regard to this invention, which consolidates the range of motion, the part operated to move the bearing 68 in the forward and backward directions and the part operated to rotate the fixed shaft 52 do not necessarily have to be the same component; for example, they may be configured so that the respective operating parts are positioned at a distance in the forward and backward directions.

[0055] Furthermore, in the fixing mechanism 50, the lever 64 and the bearing 68 (lever unit 60) are disposed on the rear side of the turntable 24. This allows the lever 64 and the bearing 68 to be disposed together on the rear side of the turntable 24. This contributes to space saving for the fixing mechanism 50.

[0056] (Second embodiment) A bench circular saw 100 as a work machine according to the second embodiment will be described below with reference to Figures 6 to 9. The bench circular saw 100 is configured similarly to the bench circular saw 10 of the first embodiment, except for the following points. In Figures 6 to 9, parts configured similarly to the bench circular saw 10 of the first embodiment are given the same reference numerals.

[0057] In the bench circular saw 100, the lower end of the support column 42 is disposed behind the turntable 24 (base 20) and is rotatably connected to the turntable 24 by a connecting shaft 48. In the bench circular saw 100, a fixing mechanism 110 is provided instead of the fixing mechanism 50. The fixing mechanism 110 is configured to include a fixed shaft 112 as a fixing portion, a bevel plate 124 as an engaging portion, and a lever unit 130.

[0058] The fixed shaft 112 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction, and is located diagonally below and to the left of the connecting shaft 48. A threaded portion 112A is provided on the front portion of the fixed shaft 112 except for the front end portion, and a male thread is formed on the outer periphery of the threaded portion 112A. The threaded portion 112A is threadedly engaged with a female threaded portion 24B formed on the rear end portion of the turntable 24, and the rear portion of the fixed shaft 112 protrudes rearward from the turntable 24. A head portion 112B protruding radially outward is provided on the rear end portion of the fixed shaft 112, and a washer 114, a spring washer 116, a guide plate 118, and a washer 120 that are fitted onto the fixed shaft 112 are arranged in front of the head portion 112B. When the fixing mechanism 110 is in a fixed state, the lower end of the support column 42 is sandwiched from both front and rear sides by the head 112B (washer 114, spring washer 116, guide plate 118, washer 120) of the fixed shaft 112 and the rear end of the turntable 24, thereby fixing the support column 42 to the turntable 24. The guide plate 118 is formed in a substantially arc-shaped plate shape with its plate thickness direction in the front and rear direction and extending in the circumferential direction of the connecting shaft 48, and a guide hole 118A, into which the fixed shaft 112 is inserted, is formed through the guide plate 118.

[0059] A connecting pin 122 is provided within the front end portion of the fixed shaft 112. The connecting pin 122 is disposed with its axial direction aligned in the left-right direction, and both axial ends of the connecting pin 122 are fixed to the fixed shaft 112.

[0060] The bevel plate 124 is formed in a generally arc-shaped plate shape with its thickness in the front-to-rear direction and extending in the circumferential direction of the connecting shaft 48. The bevel plate 124 is disposed diagonally below and to the left of the connecting shaft 48 and is fixed to the support column 42. The bevel plate 124 is also located rearward of the fixed shaft 112.

[0061] A guide hole 124A (see FIG. 7) is formed through the bevel plate 124, and the guide hole 124A is formed as an elongated hole extending in the rotational direction of the support pillar 42. The guide hole 124A has a first guide hole portion 124A1 that constitutes one side portion of the guide hole 124A in the rotational direction of the support pillar 42 (the portion on the arrow A side in FIG. 7) and a second guide hole portion 124A2 that constitutes the other side portion of the guide hole 124A in the rotational direction of the support pillar 42 (the portion on the arrow B side in FIG. 7). The width dimension of the first guide hole portion 124A1 is set wider than the width dimension of the second guide hole portion 124A2.

[0062] The lever unit 130 includes a lever shaft 132, a lever 134 as an operating portion, a bearing 138 as a restricting member, and a return spring 142 as a biasing member. The lever shaft 132 is formed in a generally long round rod shape extending in the front-rear direction. The lever shaft 132 is disposed within the turntable 24 and is supported by the turntable 24 so as to be movable in the front-rear direction. The rear end portion of the lever shaft 132 is inserted into the fixed shaft 112 and is supported by the fixed shaft 112 so as to be movable relative to the fixed shaft 112 in the front-rear direction. The rear end portion of the lever shaft 132 protrudes rearward from the fixed shaft 112. A connecting hole 132A is formed through the lever shaft 132 in the left-right direction at a position corresponding to the connecting pin 122. The connecting hole 132A is formed as an elongated hole with the front-rear direction as viewed from the left-right direction. The diameter of the connecting pin 122 is set to be slightly smaller than the width dimension of the connecting hole 132A. The connecting pin 122 is inserted into the connecting hole 132A so as to be movable in the front-rear direction, whereby the lever shaft 132 is connected to the fixed shaft 112 so as to be rotatable integrally with the fixed shaft 112 and so as to be movable relative to the fixed shaft 112 in the front-rear direction.

[0063] The lever 134 includes a connecting tubular portion 134A and a lever portion 134B serving as a grip. The connecting tubular portion 134A is formed in a substantially cylindrical shape with its axial direction extending in the front-to-rear direction, and the lever portion 134B extends radially outward (to the left) from the connecting tubular portion 134A. A sleeve 136 is fitted into the rear portion of the connecting tubular portion 134A, and the connecting tubular portion 134A is connected to the front end of the lever shaft 132 by the sleeve 136 so as to be immovable relative to the lever. As a result, the lever 134 is connected to the fixed shaft 112 so as to be rotatable integrally with the fixed shaft 112 and so as to be movable relative to the lever 134 in the front-to-rear direction. Therefore, in the second embodiment as well, the fixing mechanism 110 is switched between a fixed state and an unlocked state by performing a rotational operation (first operation) of the lever 134 about the axis AL2 of the fixed shaft 112. Furthermore, by moving the lever unit 130 in the front-rear direction, the front-rear position of the lever unit 130 can be switched between a first position (the position shown in FIG. 8) and a second position (the position shown in FIG. 9).

[0064] The tip of lever portion 134B is exposed and operable to the left from the front end of turntable 24. This allows an operator to operate fixing mechanism 110 by gripping the tip of lever portion 134B.

[0065] The bearing 138 is a ball bearing. The bearing 138 is fixed to the rear end of the lever shaft 132 by press fitting, and is disposed adjacent to the rear side of the fixed shaft 112. A fixing screw 140 is threadedly engaged with the rear end of the lever shaft 132, and the head of the fixing screw 140 protrudes rearward from the lever shaft 132 to prevent the bearing 138 from falling off the lever shaft 132. The diameter of the bearing 138 is set slightly smaller than the width dimension of the first guide hole portion 124A1 of the bevel plate 124, and larger than the width dimension of the second guide hole portion 124A2.

[0066] The return spring 142 is a compression coil spring that is fitted onto the front end of the lever shaft 132. The front end of the return spring 142 is engaged with the sleeve 136, and the rear end of the return spring 142 is engaged with the turntable 24 via a washer 144, so that the return spring 142 biases the lever 134 forward (towards the first position).

[0067] Here, when the lever unit 130 is in the first position, the connecting pin 122 is disposed at the rear end of the connecting hole 132A, restricting the forward movement of the lever shaft 132. Also, when the lever unit 130 is in the first position, the bearing 138 is disposed at a position overlapping the bevel plate 124 in the front-rear direction.

[0068] Furthermore, when the head portion 32 (support pillar 42) is in the perpendicular position, as viewed from the rear, the bearing 138 is disposed within the end portion on the other side in the rotational direction of the first guide hole 124A1 of the bevel plate 124. In other words, the bearing 138 is disposed on one side in the rotational direction (the side in the direction of arrow A in FIG. 7) with respect to the second guide hole 124A2 of the bevel plate 124. As a result, when the fixing mechanism 110 is in the first position, the inner periphery of the first guide hole 124A1 functions as a stopper, restricting rotation of the support pillar 42 to one side in the rotational direction (the right side).

[0069] On the other hand, when lever unit 130 is in the second position, lever unit 130 moves rearward relative to fixed shaft 112, and connecting pin 122 is positioned at the front end of connecting hole 132A. Also, when lever unit 130 is in the second position, bearing 138 is positioned rearward of bevel plate 124 and falls out of guide hole 124A. Therefore, by performing a movement operation (second operation) that moves lever 134 rearward against the biasing force of return spring 142, the position of lever unit 130 (bearing 138) switches from the first position to the second position, and rotation of support pillar 42 in one direction is permitted.

[0070] In the second embodiment, too, the fixing mechanism 110 is switched between a fixed state and an unlocked state by rotating the lever 134 around the axis AL2 of the fixed shaft 112, which serves as the predetermined axis. Furthermore, by moving the lever 134 rearward along the axis AL2, the front-to-rear position of the lever unit 130 (bearing 138) is switched from the first position to the second position, and the restriction on rotation by the bearing 138 to one side of the rotation direction relative to the support column 42 is released. Therefore, in the second embodiment, too, the operator does not need to operate separate operating units when changing the head unit 32 from the perpendicular position to a position tilted to the right with respect to the turntable 24. Therefore, similar to the first embodiment, the operability when changing the position of the head unit 32 relative to the turntable 24 can be improved.

[0071] In the second embodiment, the lever portion 134B of the lever 134 is exposed and operable at the front end of the turntable 24. Therefore, an operator positioned in front of the miter saw 100 can operate the lever portion 134B to change the tilt position of the head portion 32 relative to the turntable 24.

[0072] In the first and second embodiments, the fixing mechanisms 50, 110 are described as mechanisms that fix the support columns 42 to the turntable 24, but they may also be mechanisms that fix other members. For example, the structure of the fixing mechanisms 50, 110 may be applied to a mechanism that fixes the turntable 24 to the base main body 22. In this case, the base main body 22 corresponds to the base of the present invention, and the turntable 24 corresponds to the support of the present invention.

[0073] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0074] 10. Tabletop circular saw (working machine) 20 base 24A Placement surface (top) 32 Head part (cutting part) 38 Circular saw blade 42 Support column (support part) 50 Fixing mechanism 52 Fixed shaft (fixed part) 58 Bevel plate (engagement part) 64 Lever (operating part) 64B Lever part (grip part) 68 Bearing (regulating part) 70 Return spring (biasing member) 100 Tabletop circular saw (working machine) 110 Fixing mechanism 112 Fixed shaft (fixed part) 124 Bevel plate (engagement part) 134 Lever (operating part) 134B Lever part (grip part) 138 Bearing (regulating part) 142 Return spring (biasing member) AL1 axis line (predetermined axis line) AL2 axis line (predetermined axis line)

Claims

1. a base having an upper surface extending in the front-rear and left-right directions on which a workpiece is placed; a cutting unit configured to be swingable in the up and down direction; a circular saw blade provided in the cutting portion; a support part connected to the base so as to be rotatable about an axial direction in the front-rear direction and supporting the cutting part; a fixing mechanism that fixes the support part to the base, the fixing mechanism including an operating unit that is operated by an operator and a restricting unit that restricts rotation of the support part at a predetermined rotation position of the support part; Equipped with By performing a first operation of the operation unit, the fixing mechanism switches between a fixed state in which the support unit is fixed to the base and a fixed release state in which the fixation to the support unit is released, A work machine in which the rotation restriction on the support part by the restriction part is released by a second operation of the operation part.

2. The work machine according to claim 1 , wherein the first operation is a rotation operation that rotates the operating unit around a predetermined axis, and the second operation is a movement operation that moves the operating unit along the predetermined axis.

3. the fixing mechanism has an engaging portion that engages with the restricting portion to restrict rotation of the support portion at the predetermined rotation position, the restricting portion is connected to the operating portion so as to be immovable relative to the operating portion, The work machine according to claim 2, wherein the restriction portion moves together with the operating portion during the second operation, thereby disengaging the restriction portion from the engaging portion.

4. the fixing mechanism has a fixing portion, When the fixing portion is rotated around the predetermined axis, the fixing mechanism is switched between the fixed state and the released state, 4. The work machine according to claim 3, wherein the operating portion is connected to the fixed portion so as to be rotatable together with the fixed portion and so as to be movable relatively along the predetermined axis.

5. the fixing portion is provided on one of the support portion and the base, The work machine according to claim 4, wherein the engaging portion is provided on the other of the support portion and the base.

6. the operating portion is configured to be movable between a first position where the restricting portion and the engaging portion are engaged with each other and a second position where the restricting portion and the engaging portion are disengaged from each other; The work machine according to claim 3, wherein the fixing mechanism has a biasing member that biases the operating part along the predetermined axis, and the operating part is biased toward the first position by the biasing member.

7. The work machine according to claim 1 , wherein the operating portion has a single grip portion that is gripped by an operator.

8. The work machine according to claim 1 , wherein the restricting portion and the operating portion are disposed on the rear side of the base.

9. The work machine according to claim 1 , wherein the operating portion is operably exposed at a front end of the base.

10. a base having an upper surface extending in the front-rear and left-right directions on which a workpiece is placed; a cutting unit configured to be swingable in the up and down direction; a circular saw blade provided in the cutting portion; a support part rotatably connected to the base, supporting the cutting part, and moving relative to the base to change the position of the circular saw blade; a fixing mechanism that fixes the support portion to the base; Equipped with The fixing mechanism includes: an operation unit operated by an operator; a fixing portion that extends along a predetermined axis and moves along the predetermined axis in response to a first operation on the operating portion, thereby switching between a fixed state in which the support portion is fixed to the base and a fixed release state in which the fixation of the support portion to the base is released; a restricting portion configured to operate coaxially with the fixed portion and restrict rotation of the support portion at a predetermined rotation position of the support portion; The invention comprises: By performing a second operation on the operating unit in the unlocked state, the restricting unit moves along the specified axis independently of the fixed unit, thereby releasing the rotation restriction state for the support unit at the specified rotation position.

11. The work machine according to claim 10 , wherein one of the fixing portion and the restricting portion is configured as a shaft member, and the other has an annular structure that covers an outer periphery of the other.

12. the first operation is a rotation operation around the predetermined axis line, and the second operation is an operation in a direction along the predetermined axis line, The fixing portion and the restricting portion operate integrally during the first operation, The work machine according to claim 10 , wherein the restricting portion moves relative to the fixing portion during the second operation.

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