Working machine

Abstract

The present invention suppresses a deterioration in workability. In a circular saw 10, an airflow AR generated by a fan 50 flows into an exhaust duct 80, and the airflow AR within the exhaust duct 80 is exhausted from an exhaust port 84K of the exhaust duct 80. Here, the exhaust port 84K is positioned on the front side of a front side bevel plate 71 of a tilting mechanism 70, and the airflow AR within the exhaust duct 80 is exhausted to the front side of the front side bevel plate 71. This makes it possible to suppress blocking of the airflow AR exhausted from the exhaust port 84K by the tilting mechanism 70. Therefore, the airflow AR exhausted from the exhaust port 84K is blown out toward the front side of a base 12, allowing chips or the like generated during cutting to be satisfactorily removed. As a result, a deterioration in the workability of the circular saw 10 can be suppressed.

Description

Work equipment

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

[0002] In work machines such as circular saws, chips and dust generated during cutting can remain on the workpiece, reducing workability. For example, chips can be blown up by the rotating circular saw blade, or the chips can obscure the markings on the workpiece, reducing workability. For this reason, circular saws equipped with a blower mechanism are known. In these circular saws, the blower mechanism, installed in the saw body, exhausts air from the blower toward the front of the saw to remove chips from the workpiece.

[0003] On the other hand, there are circular saws in which the circular saw body is connected to a base by a tilting mechanism so as to be tiltable around a virtual axis (see, for example, Patent Document 1 below). This tilting mechanism includes a front guide fixed to the base and a front tilting plate to which the circular saw body is fixed, and the front tilting plate is connected to the front guide so as to be tiltable around the virtual axis.

[0004] Patent application 2022-175822

[0005] For example, if the blower mechanism is applied to the circular saw described in Patent Document 1, the tilting mechanism (front guide and front tilting plate) located at the front of the circular saw body increases the distance between the exhaust port of the blower mechanism and the front end of the base. This may prevent a sufficient volume of air from being blown forward toward the front of the circular saw. This may result in insufficient removal of chips and other debris from the workpiece.

[0006] Another issue is that the tilting mechanism (front guide and front tilting plate) located at the front of the circular saw body may block the blower air exhausted from the blower mechanism, making it difficult to deliver the blower air to the front of the circular saw. To address this issue, for example, by shifting the front guide and front tilting plate left or right relative to the exhaust port of the blower mechanism, the tilting mechanism can be prevented from blocking the blower air. However, in this case, the tilting mechanism becomes larger because it is spaced apart from the virtual axis. This may also result in reduced workability. Furthermore, by providing an insertion portion in the front guide and front tilting plate through which the blower mechanism passes and locating the exhaust port of the blower mechanism in front of the tilting mechanism, the tilting mechanism can be prevented from blocking the blower air. However, the front guide has a guide groove or the like through which a shaft extending from the front tilting plate is inserted, making it difficult to secure space in the front guide and front tilting plate for the insertion portion.

[0007] Another issue is that operating the cutting depth adjustment mechanism, which adjusts the cutting depth of the circular saw blade, changes the position of the circular saw body relative to the base, which can cause the exhaust port of the blower mechanism to face in a direction other than the front of the circular saw. In this case, it becomes difficult to effectively remove chips and other debris from the workpiece in front of the circular saw, which can reduce workability.

[0008] In consideration of the above, an object of the present invention is to provide a work machine that can suppress a decrease in workability.

[0009] One or more embodiments of the present invention are a working machine comprising: a circular saw body including a motor, a fan that rotates when driven by the motor to generate an airflow, a housing that accommodates the motor and the fan, a circular saw blade that rotates when driven by the motor, and an exhaust duct into which the airflow in the housing is introduced; a base provided on the underside of the housing; and a tilting mechanism that connects the circular saw body to the base and tilts the circular saw body relative to the base around an imaginary axis that extends in the front-to-back direction below the base, wherein the tilting mechanism has a front support part that is disposed on the front side of the circular saw body and fixed to the base, and the exhaust duct has an exhaust port that exhausts the introduced airflow in front of the front support part, and when the circular saw body is tilted relative to the base by the tilting mechanism, the exhaust port rotates around the imaginary axis.

[0010] In one or more embodiments of the present invention, the tilting mechanism allows the circular saw body to be tilted between an upright position in which the circular saw blade is positioned with the left-right direction as the thickness direction of the plate, and an inclined position inclined from the upright position to one side in the left-right direction, and the exhaust port is open toward the virtual axis at any position between the upright position and the inclined position of the circular saw blade.

[0011] One or more embodiments of the present invention are a work machine in which a portion of the exhaust duct is positioned above the front support part when the circular saw blade is in any position between the upright position and the inclined position.

[0012] In one or more embodiments of the present invention, the tilting mechanism includes a front support portion disposed on the front side of the circular saw body and fixed to the base, a rear support portion disposed on the rear side of the circular saw body and fixed to the base, and a connecting portion connected to the circular saw body and connected to the front support portion and the rear support portion, a front end of the circular saw body is rotatably connected to the connecting portion by a rotation shaft whose axial direction is in the left-right direction, and the exhaust duct includes: a rear duct that forms a rear portion of the exhaust duct, has a rear connecting portion at its front end, is attached to the housing so as to be movable integrally, and into which the air flow flows, and a front duct that forms a front portion of the exhaust duct, has a front connecting portion at its rear end, and exhausts the air flow, and the rear connecting portion and the front connecting portion are connected to be rotatable relative to each other about the axis of the rotation shaft, and a portion of the air flow passage in the exhaust duct passes above the rotation shaft in the front-to-rear direction.

[0013] One or more embodiments of the present invention are a work machine including: a motor; a fan that rotates when driven by the motor to generate an airflow; a housing that accommodates the motor and the fan; a base provided below the housing; a circular saw blade that rotates when driven by the motor; and an exhaust duct into which the airflow inside the housing is introduced, wherein the exhaust duct includes: a rear duct that forms a rear section of the exhaust duct, has a rear connection section at a front end, is attached to the housing so as to be movable integrally, and into which the airflow is introduced; and a front duct that forms a front section of the exhaust duct, has a front connection section at a rear end, and exhausts the airflow to the front side of the housing, wherein the housing is rotatably connected to the base by a rotation shaft whose axial direction is in the left-right direction, the rear connection section and the front connection section are connected to be capable of relative rotation about the axis of the rotation shaft, and a portion of the airflow passage in the exhaust duct passes in the front-to-rear direction above the rotation shaft.

[0014] One or more embodiments of the present invention are a work machine in which the housing has a cover portion that covers the circular saw blade from above, and the rear duct includes a main body portion attached to the side of the cover portion, and an extension portion that extends from the main body portion to the opposite side of the circular saw blade and has the rear connection portion at its tip.

[0015] One or more embodiments of the present invention are a work machine that includes a lighting unit that emits light to the outside of the housing, the rear duct being composed of a first duct member and a second duct member, and the lighting unit being held by the first duct member and the second duct member.

[0016] One or more embodiments of the present invention are a work machine in which a recess is formed inside the housing, and a portion of the rear duct covers the recess to prevent the air flow from entering the recess.

[0017] One or more embodiments of the present invention are a work machine in which the housing has a motor housing located on the left side of the cover portion and accommodating the motor, the cover portion has a housing connection portion to which the motor housing is connected, and the recess is formed in the housing connection portion.

[0018] One or more embodiments of the present invention are a work machine comprising: a motor; a fan that rotates when driven by the motor to generate an airflow; a housing that accommodates the motor and the fan; a base provided on the underside of the housing; and an exhaust duct into which the airflow inside the housing flows, the exhaust duct having a straightening portion disposed inside the housing, the straightening portion straightening the airflow inside the housing and causing the airflow to flow into the exhaust duct.

[0019] In one or more embodiments of the present invention, the tilting mechanism is a work machine having a rear support part disposed on the rear side of the circular saw body and fixed to the base, and a connecting part connected to the circular saw body and connected to the front support part and the rear support part, and the exhaust duct is fixed to the connecting part.

[0020] One or more embodiments of the present invention are a work machine in which the rear connection portion is disposed inside the front connection portion.

[0021] One or more embodiments of the present invention are a work machine in which the front connection portion has a front outer peripheral wall extending circumferentially around the pivot shaft, and the rear connection portion has a rear outer peripheral wall extending circumferentially around the pivot shaft, and the front outer peripheral wall is positioned radially outward from the rear outer peripheral wall with a predetermined gap therebetween.

[0022] One or more embodiments of the present invention are directed to a work machine in which the rear connection portion and the front connection portion are disposed radially outward from the pivot shaft.

[0023] One or more embodiments of the present invention are a working machine comprising: a circular saw body including a motor, a fan that rotates when driven by the motor to generate an airflow, a housing that accommodates the motor and the fan, and an exhaust duct into which the airflow in the housing is introduced; a base provided on the underside of the housing; and a tilting mechanism that connects the circular saw body to the base and tilts the circular saw body relative to the base, wherein the tilting mechanism has a front support part that is disposed on the front side of the circular saw body and fixed to the base, and the front support part is provided with a guide part that guides the tilt of the circular saw body relative to the base, a portion of the exhaust duct overlaps the guide part when viewed in the vertical direction, and the exhaust duct has an exhaust port that exhausts the introduced airflow in front of the front support part.

[0024] According to one or more embodiments of the present invention, it is possible to suppress a decrease in workability.

[0025] 1 is a plan view of a circular saw according to the present embodiment, as seen from above; a side view of the circular saw shown in FIG. 1, as seen from the left side; a front view of the circular saw shown in FIG. 1, as seen from the front side; a cross-sectional view (cross-sectional view taken along line 4-4 in FIG. 2) of the interior of the circular saw body shown in FIG. 2, as seen from above; a perspective view of the saw cover shown in FIG. 1, as seen from the left front; a perspective view of the exhaust duct shown in FIG. 2, as seen from the left front, showing the rear duct of the exhaust duct fitted into the duct fitting portion of the saw cover shown in FIG. 5; a cross-sectional view (cross-sectional view taken along line 8-8 in FIG. 1) of the periphery of the exhaust duct shown in FIG. 1, as seen from the left side; (A) is a cross-sectional view (cross-sectional view taken along line 9A-9A in FIG. 8) of the exhaust section of the exhaust duct shown in FIG. 8, as seen from the front side; and (B) is a cross-sectional view (cross-sectional view taken along line 9B-9B in FIG. 9A) of the exhaust section shown in (A) as seen from the left side. 4A is a front view of the circular saw body shown in Fig. 3 rotated to an inclined position, as viewed from the front side, and Fig. 4B is a side view of the circular saw body shown in Fig. 2 switched to a minimum cutting depth position, as viewed from the left side, and Fig. 4C is a partial cross-sectional view showing the positional relationship between the front outer peripheral wall and the rear outer peripheral wall in the state of Fig. 4A.

[0026] The following describes a circular saw 10 as a work machine according to this embodiment, with reference to the drawings. 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 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 circular saw 10 unless otherwise specified.

[0027] 1 to 3, the circular saw 10 is a power tool for cutting workpieces. The circular saw 10 includes a base 12 and a circular saw body 20. The circular saw 10 also includes a tilting mechanism 70 that connects the circular saw body 20 to the base 12 so that the circular saw body 20 can be tilted, and an exhaust duct 80 that exhausts airflow AR generated inside the circular saw body 20 from the front side of the tilting mechanism 70 toward the front side of the base 12.

[0028] (Regarding the base 12) The base 12 is formed in the shape of a generally rectangular plate with its thickness extending vertically and its length extending forward and backward. When the circular saw 10 is used for cutting, the base 12 is placed on the workpiece and moved forward. An insertion hole 12A for accommodating the circular saw blade 14 is formed through the right side of the base 12. The insertion hole 12A is formed in a generally rectangular shape with its length extending forward and backward, and is a through-hole with a width extending vertically.

[0029] 4, the circular saw blade 14 is formed in a generally circular plate shape with its thickness extending in the left-right direction, and the center of the circular saw blade 14 is fixed to an output shaft 54 ​​of the drive mechanism 40, which will be described later. A portion of the circular saw blade 14 is disposed within the insertion portion 12A, with an upper portion of the circular saw blade 14 protruding upward from the base 12 and a lower end portion of the circular saw blade 14 protruding downward from the base 12.

[0030] (Regarding the Circular Saw Body 20) As shown in FIGS. 1 to 4, the circular saw body 20 includes a housing 22, a battery 36, and a drive mechanism 40.

[0031] (Regarding the housing 22) The housing 22 is made up of multiple housing members, forms the outer shell of the circular saw body 20, and is disposed above the base 12. The housing 22 includes a saw cover 24 that serves as a cover for covering the circular saw blade 14, and a motor housing 26 that houses the drive mechanism 40, which will be described later.

[0032] The saw cover 24 constitutes the right end of the housing 22. The saw cover 24 is formed in a generally semicircular plate shape with its thickness extending in the left-right direction and its convex shape extending upward and its concave shape opening downward. The upper part of the circular saw blade 14 is housed in and covered by the saw cover 24. The saw cover 24 is made of metal.

[0033] The saw cover 24 is connected to the base 12 by the cutting depth adjustment mechanism 30 via a tilting mechanism 70 (described later). Specifically, a support tube 24A is provided at the front end of the saw cover 24, and the support tube 24A is formed in a generally cylindrical shape with its axial direction extending in the left-right direction. The cutting depth adjustment mechanism 30 includes a rotation shaft 32 with its axial direction extending in the left-right direction and a support plate 34 that supports the rotation shaft 32. The rotation shaft 32 is inserted into the support tube 24A, and the front end of the saw cover 24 is rotatably supported by the rotation shaft 32. This allows the circular saw body 20 to be rotatably connected to the base 12 with its axial direction extending in the left-right direction. When the rotation shaft 32 is inserted into the support tube 24A, the left end of the rotation shaft 32 protrudes leftward from the support tube 24A. By operating the cutting depth adjustment mechanism 30, the circular saw body 20 is configured to be positioned at any position between the maximum cutting depth position (the state shown in Figures 1 to 3) and the minimum cutting depth position (the state shown in Figure 11).

[0034] As shown in Figures 4 and 5, a housing connection portion 24B is provided on the left side of the saw cover 24. The housing connection portion 24B is formed as a substantially rectangular cylinder with its axis extending in the left-right direction and protruding to the left from the saw cover 24. A partition wall 24C is formed inside the housing connection portion 24B, which partitions the interior of the housing connection portion 24B in the left-right direction. A first housing tube portion 24D is formed in the approximate center of the partition wall 24C. The first housing tube portion 24D is formed as a substantially cylindrical shape and protrudes to the left from the partition wall 24C. A second housing tube portion 24E is formed in the housing connection portion 24B diagonally below and rearward of the first housing tube portion 24D. The second housing tube portion 24E is formed as a substantially stepped, bottomed cylinder that opens to the right and protrudes to the left from the partition wall 24C.

[0035] A duct connection hole 24F is formed in the vertical middle of the front wall of the housing connection portion 24B. The duct connection hole 24F penetrates in the front-rear direction and opens to the left. A first rib 24G is formed in the partition wall 24C in front of the first accommodating cylindrical portion 24D. The first rib 24G extends diagonally downward and forward from the first accommodating cylindrical portion 24D, with the tip of the first rib 24G located approximately in the vertical middle of the duct connection hole 24F. A second rib 24H is formed in the partition wall 24C below the first rib 24G and is disposed approximately parallel to the first rib 24G. A recess 24J, open to the left, is formed in the housing connection portion 24B between the center of the second accommodating cylindrical portion 24E and the first rib 24G. The second rib 24H is disposed within the recess 24J. As a result, the bottom wall of the recess 24J is formed in an uneven shape by the second accommodating cylindrical portion 24E, the second rib 24H, and the like.

[0036] A duct fitting portion 24K is formed on the left side surface of the saw cover 24, in front of the duct connection hole 24F of the housing connection portion 24B. The duct fitting portion 24K is formed in a generally rectangular tubular shape with its longitudinal direction extending in the front-to-rear direction, and protrudes to the left from the saw cover 24. The open end of the duct fitting portion 24K is positioned flush with the left side surface of the partition wall 24C. The duct fitting portion 24K utilizes two rib structures, which are provided to improve the strength of the saw cover 24, as a support structure for the exhaust duct 80, which will be described later.

[0037] 1 to 4, the motor housing 26 is generally box-shaped and open to the right. The motor housing 26 is disposed to the left of the housing connection portion 24B of the saw cover 24 and fastened to the housing connection portion 24B. A plurality of air intake ports 26A are formed in the left wall of the motor housing 26, and the air intake ports 26A are formed as elongated holes extending in the front-to-rear direction. The air intake ports 26A provide communication between the interior and exterior of the motor housing 26.

[0038] A battery mounting section 26B is provided at the rear end of the left section of the motor housing 26. A battery 36 is mounted on top of the battery mounting section 26B. The battery 36 is electrically connected to a controller 44 (see FIG. 4) and a motor 42 (see FIG. 4) of a drive mechanism 40 (described later).

[0039] A handle portion 26C is provided at the right end of the motor housing 26. When viewed from the left side, the handle portion 26C is formed in a generally U-shape that opens diagonally downward and forward, and the front and rear ends of the handle portion 26C are connected to the motor housing 26. An operable trigger 38 is provided on the handle portion 26C. Operating the trigger 38 presses a switch (not shown) housed inside the handle portion 26C. This switch is electrically connected to a controller 44, and is turned on in response to operation of the trigger 38, thereby activating a drive mechanism 40 (described below).

[0040] (Regarding the drive mechanism 40) As shown in FIG. 4, the drive mechanism 40 includes a motor 42 and an output shaft 54. The motor 42 is a brushless motor housed in the motor housing 26 and electrically connected to the controller 44. The controller 44 is housed in the motor housing 26 on the left side of the motor 42. The motor 42 has a motor shaft 42A whose axial direction is in the left-right direction. The left end of the motor shaft 42A is rotatably supported by a motor bearing 46 fixed to the motor housing 26. The right end portion of the motor shaft 42A is rotatably supported by a motor bearing 48 fixed to the first housing cylindrical portion 24D of the housing connection portion 24B of the saw cover 24. A pinion gear is formed on the right end of the motor shaft 42A.

[0041] A fan 50 is provided on the right end portion of the motor shaft 42A so as to be integrally rotatable. The fan 50 is located on the left side of the saw cover 24. The fan 50 is configured as a so-called centrifugal fan, and when rotated by the drive of the motor 42, generates an air flow AR that flows into the motor housing 26 through the air intake port 26A of the motor housing 26. A fan guide 52 is provided inside the motor housing 26 radially outward of the fan 50, and the fan guide 52 directs the air flow AR toward the housing connection portion 24B. The air flow AR flows into an exhaust duct 80, which will be described later, and is exhausted from the exhaust duct 80 to the front side of the circular saw body 20.

[0042] The output shaft 54 ​​is disposed within the second accommodating cylindrical portion 24E of the housing connection portion 24B of the saw cover 24, with the left-right direction as its axial direction, and is located below the motor shaft 42A. The left end of the output shaft 54 ​​is rotatably supported by a bearing 56 fixed to the left end of the second accommodating cylindrical portion 24E, and a left-right intermediate portion of the output shaft 54 ​​is rotatably supported by a bearing (not shown). An output gear 60 is provided at the left-right intermediate portion of the output shaft 54 ​​so as to be integrally rotatable, and the output gear 60 is meshed with a pinion gear of the motor shaft 42A.

[0043] The center of the circular saw blade 14 is fixed to the right end of the output shaft 54 ​​by a fixing bolt 62. Specifically, the center of the circular saw blade 14 is sandwiched between washer members 64 from the outside in the left-right direction, and the washer members 64 are fastened and fixed to the output shaft 54 ​​by the fixing bolt 62. As a result, when the motor 42 is driven, the circular saw blade 14 is configured to rotate together with the output shaft 54 ​​around the axis of the output shaft 54 ​​to one side.

[0044] The lower part of the circular saw blade 14 is covered by a protective cover 66 (see FIGS. 2 and 3). The protective cover 66 is formed in a generally semicircular shape that is convex downward when viewed from the right side, and is formed in a concave shape that is open upward. The protective cover 66 is connected to the output shaft 54 ​​so as to be rotatable about the axis of the output shaft 54. The protective cover 66 is urged about the axis of the output shaft 54 ​​by a spring (not shown) and is held in the position shown in FIGS. 2 and 3. When cutting with the circular saw 10, the protective cover 66 rotates about the axis of the output shaft 54 ​​against the urging force of the spring due to the workpiece, exposing the cutting portion of the circular saw blade 14.

[0045] (Regarding the tilting mechanism 70) As shown in FIGS. 1 to 3, 8, and 10, the tilting mechanism 70 connects the circular saw body 20 to the base 12, and when the operator activates the tilting mechanism 70, the circular saw body 20 tilts relative to the base 12. Specifically, the tilting mechanism 70 allows the circular saw body 20 to rotate (tilt) between an upright position (the position shown in FIGS. 1 to 3, also referred to as a non-tilted position) and a tilted position (the position shown in FIG. 10) tilted approximately 45 degrees to the right from the upright position. When the tilting mechanism 70 is activated, the circular saw body 20 rotates about an imaginary axis AX (see FIGS. 3 and 10) extending in the front-to-rear direction. The imaginary axis AX is located below the base 12 and is set at a position overlapping the circular saw blade 14 in a front view.

[0046] The tilting mechanism 70 extends in the front-to-rear direction above the base 12. The tilting mechanism 70 includes a front bevel plate 71 serving as a front support portion that constitutes the front end of the tilting mechanism 70, a rear bevel plate 73 serving as a rear support portion that constitutes the rear end of the tilting mechanism 70, and a connecting plate 74 serving as a connecting portion.

[0047] The front bevel plate 71 is formed in a plate shape with its thickness extending in the front-to-rear direction as a whole. A guide fixing portion 71A that protrudes outward in the left-right direction and forward is provided at the lower end of the front bevel plate 71. The front bevel plate 71 is disposed in front of the saw cover 24 at a distance, and the guide fixing portion 71A is fastened and fixed to the base 12.

[0048] A guide hole 71B serving as a guide portion is formed through the front bevel plate 71. In a front view, the guide hole 71B extends in a curved (arcuate) shape along the rotation direction of the circular saw body 20. Specifically, the guide hole 71B is formed in a generally arcuate shape centered on the imaginary axis AX. The upper surface of the front bevel plate 71 is curved in a generally arcuate shape that protrudes diagonally upward to the right in a front view, corresponding to the guide hole 71B. A switching lever 72 is provided at the right end of the front bevel plate 71, and the switching lever 72 protrudes forward from the front bevel plate 71 so as to be rotatable. When the switching lever 72 is operated, the switching lever 72 switches between a state in which the circular saw body 20 is restricted from moving to the right at an intermediate position between the upright position and the inclined position, and a state in which the circular saw body 20 is permitted to move to the right at the intermediate position.

[0049] The rear bevel plate 73 has a configuration substantially similar to that of the front bevel plate 71, which is inverted in the front-rear direction. That is, the rear bevel plate 73 is formed in a plate shape with its thickness direction in the front-rear direction, and a guide fixing portion 73A provided at the lower end of the rear bevel plate 73 is fastened and fixed to the base 12. Similar to the front bevel plate 71, a guide hole (not shown) is formed through the rear bevel plate 73, and the guide hole is curved in a substantially arc shape centered on the imaginary axis AX in a front view.

[0050] The connecting plate 74 is composed of a front connecting plate portion 74A that forms the front end of the connecting plate 74, a rear connecting plate portion 74B that forms the rear end of the connecting plate 74, and a plate connecting portion 74C that connects the front connecting plate portion 74A and the rear connecting plate portion 74B.

[0051] The front connecting plate portion 74A is formed in a plate shape with its thickness in the front-to-rear direction, and is disposed adjacent to the rear side of the front bevel plate 71. The support plate 34 of the cutting depth adjustment mechanism 30 described above is disposed behind the front bevel plate 71 and fixed to the front bevel plate 71. In this way, the circular saw body 20 is fixed to the connecting plate 74.

[0052] A fixed shaft 75 (see FIGS. 3, 8, and 10) is provided on the front connecting plate 74A. The fixed shaft 75 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction. The rear end of the fixed shaft 75 is fixed to the front connecting plate 74A, and the fixed shaft 75 protrudes forward from the front connecting plate 74A. The diameter of the fixed shaft 75 is set slightly smaller than the width of the guide hole 71B of the front bevel plate 71. The fixed shaft 75 passes through the lower end of the guide hole 71B, and the front end of the fixed shaft 75 protrudes forward from the front bevel plate 71. As a result, when the circular saw body 20 is tilted, the fixed shaft 75 moves along the guide hole 71B. In this way, the guide hole 71B functions as a guide that guides the tilt of the circular saw body 20.

[0053] A fixed lever 76 is provided at the front end of the fixed shaft 75, and the fixed lever 76 is threadedly engaged with a threaded portion formed on the outer periphery of the front end of the fixed shaft 75. As a result, by fastening the fixed lever 76 to the front bevel plate 71, the front connecting plate portion 74A is fixed to the front bevel plate 71, and the circular saw body 20 is connected to the base 12 so as not to move relative to it.

[0054] The rear connecting plate 74B is formed in a plate shape with its thickness extending in the front-to-rear direction. Similar to the front connecting plate 74A, the rear connecting plate 74B is provided with a fixed shaft 77 (see FIG. 1 ), which protrudes rearward from the rear connecting plate 74B. The fixed shaft 77 passes through a lower end of a guide hole in the rear bevel plate 73, and its rear end protrudes rearward from the rear bevel plate 73. A fixing knob 78 is provided at the rear end of the fixed shaft 77, and the fixing knob 78 is threadedly engaged with a threaded portion formed on the outer periphery of the rear end of the fixed shaft 77. Thus, by tightening the fixing knob 78 to the rear bevel plate 73, the rear connecting plate 74B is fixed to the rear bevel plate 73, and the circular saw body 20 is connected to the base 12 so as not to move relative to the base 12.

[0055] The plate connecting portion 74C is formed in a generally elongated plate shape that extends in the front-to-rear direction and has its thickness in the up-down direction, and is disposed above the base 12. The front end of the plate connecting portion 74C is connected to the lower end of the left part of the front connecting plate portion 74A, and the rear end of the plate connecting portion 74C is connected to the lower end of the rear connecting plate portion 74B. In this way, the front connecting plate portion 74A and the rear connecting plate portion 74B are connected by the plate connecting portion 74C.

[0056] (Regarding the exhaust duct 80) As shown in Figures 1 to 4 and 6 to 11, the exhaust duct 80 is a duct that guides the airflow AR inside the motor housing 26 to the front side of the tilt mechanism 70 and exhausts it toward the front region of the base 12. In other words, the exhaust duct 80 is a blower duct. The exhaust duct 80 is configured to include a rear duct 82 that forms the rear portion of the exhaust duct 80, and a front duct 84 that forms the front portion of the exhaust duct 80. The exhaust duct 80 is configured as a molded body made of resin. In this embodiment, the exhaust duct 80 is molded from a hard resin that has little flexibility.

[0057] The rear duct 82 is formed in a generally U-shaped tube shape that opens to the left in a plan view (vertical view). Specifically, the rear duct 82 includes a main body duct portion 82A extending in the front-to-rear direction, an inlet duct portion 82B protruding to the left from the rear end of the main body duct portion 82A, and an extension duct portion 82C extending to the left from the front end of the main body duct portion 82A. The rear duct 82 is also formed by a first duct member 82-1 (see FIG. 6) and a second duct member 82-2 (see FIG. 6) that are divided into two parts in the left-to-right direction. The rear duct 82 is formed by assembling the first duct member 82-1 and the second duct member 82-2 together. A fixing portion 82D protruding forward is provided on the front side of the main body duct portion 82A. The plan view refers to the state when the work machine (circular saw 10) is viewed vertically from above, as shown in FIG. 1.

[0058] The main body duct portion 82A and the fixing portion 82D are fitted into the duct fitting portion 24K of the saw cover 24 (see FIG. 7), and the fixing portion 82D is fixed to the saw cover 24 with a fixing screw SC. This allows the rear duct 82 to be connected to the saw cover 24 (circular saw main body 20) so as to be movable integrally therewith.

[0059] The inlet duct portion 82B is formed with an inlet 82E (see FIG. 4) that opens to the rear, and the inlet 82E is disposed within the duct connection hole 24F of the housing connection portion 24B of the saw cover 24. This allows the front end of the housing connection portion 24B to communicate with the rear end of the rear duct 82, allowing the airflow AR to flow into the rear duct 82 from the inlet 82E.

[0060] A lighting holder 82F is provided below the inlet duct 82B. The lighting holder 82F is formed in a generally rectangular cylindrical shape and extends in a direction that slopes downward toward the front in a side view. An illumination lens 90 (see FIGS. 6 and 7) is provided within the lighting holder 82F as a lighting unit. The illumination lens 90 is sandwiched between the first duct member 82-1 and the second duct member 82-2 on both the left and right sides. This allows the lighting holder 82F to hold the illumination lens 90. The illumination lens 90 is made of a light-transmitting resin material or the like, and an LED (not shown) is provided within the illumination lens 90 as a light source. The LED is electrically connected to the controller 44 and emits emitted light diagonally forward and to the right. This allows the light emitted from the illumination lens 90 to illuminate the front side of the circular saw blade 14.

[0061] The rear end of the inlet duct 82B is provided with a rectifying cover 82G (see FIGS. 6 and 7) as a rectifying section. The rectifying cover 82G is formed in a generally plate-like shape with its thickness extending in the left-right direction and extends rearward from the light holder 82F of the first duct member 82-1. The rectifying cover 82G is disposed over the opening of the recess 24J in the housing connection portion 24B of the saw cover 24, closing the opening of the recess 24J (see FIG. 7). That is, the outer shape of the rectifying cover 82G is formed to correspond to the shape of the opening of the recess 24J. This prevents the airflow AR from entering the recess 24J and rectifies the flow of the airflow AR toward the inlet duct 82B.

[0062] The extension duct portion 82C extends diagonally downward to the left from the front end of the main duct portion 82A, and the tip of the extension duct portion 82C is bent forward. A rear hinge portion 82H is provided at the front end of the extension duct portion 82C as a rear connection portion. The rear hinge portion 82H is formed in a generally hollow cylindrical shape with its axial direction extending in the left-right direction. The rear end of the rear hinge portion 82H is connected to the extension duct portion 82C, so that the interior of the rear hinge portion 82H communicates with the interior of the extension duct portion 82C. The rear hinge portion 82H is disposed coaxially with the pivot shaft 32, and a rear outer peripheral wall 82J of the rear hinge portion 82H extends circumferentially around the pivot shaft 32. A communication hole 82K is formed through the front end of the rear outer peripheral wall 82J, and the communication hole 82K opens obliquely upward toward the front. An inner tube 82L is provided in the center of the rear hinge portion 82H. The inner tube 82L is formed in a cylindrical shape with its axial direction extending in the left-right direction, and the interior of the inner tube 82L is penetrated in the left-right direction. The left end of the pivot shaft 32 is inserted into the inner tube 82L, and the inner tube 82L is disposed radially outward of the pivot shaft 32 with a predetermined gap therebetween. For convenience, the components of the rear duct 82, which constitutes the rear portion of the exhaust duct 80, are named with the word "rear" at the beginning, such as "rear...", but this does not necessarily mean that the components are provided behind the rear duct 82. For example, the rear hinge portion 82H is provided in front of the rear duct 82. This also applies to the front duct 84. In the present invention, the rear and front sides of the components of the exhaust duct 80 may be referred to as the first and second sides, respectively.

[0063] The front duct 84 is formed in a generally crank-shaped cylindrical shape when viewed from the left-right direction. Specifically, the front duct 84 includes an intermediate duct portion 84A extending in the up-down direction, a connecting duct portion 84B extending rearward from the lower end of the intermediate duct portion 84A, and an outlet duct portion 84C extending frontward from the upper end of the intermediate duct portion 84A. Note that, like the rear duct 82, the front duct 84 is formed by a duct member divided into two in the left-right direction, and these duct members are assembled together to form the front duct 84.

[0064] The intermediate duct portion 84A slopes to the right as it extends upward in a front view. That is, the upper end of the intermediate duct portion 84A is positioned offset to the right relative to the lower end of the intermediate duct portion 84A. A portion protruding to the right is provided in the vertically middle portion of the intermediate duct portion 84A, and a fixing hole 84D penetrating the front-to-rear direction is formed in this portion. The intermediate duct portion 84A is positioned rearward of the front connecting plate portion 74A of the tilting mechanism 70, and fixing screws (not shown) are inserted through the fixing holes 84D and threadedly engage with the front connecting plate portion 74A. This fastens and fixes the intermediate duct portion 84A to the front connecting plate portion 74A. As a result, the intermediate duct portion 84A (front duct 84) is connected (fixed) to the connecting plate 74 so as to be movable integrally therewith.

[0065] In a side view, the connection duct portion 84B extends diagonally downward and rearward from the lower end of the intermediate duct portion 84A. A front hinge portion 84E is provided at the rear end of the connection duct portion 84B as a front connection portion. The front hinge portion 84E is formed in a generally hollow cylindrical shape with its axial direction extending in the left-right direction. The front end of the front hinge portion 84E is connected to the connection duct portion 84B, so that the interior of the front hinge portion 84E communicates with the interior of the connection duct portion 84B. The front hinge portion 84E is disposed coaxially with the pivot shaft 32, and a front outer peripheral wall 84F of the front hinge portion 84E extends along the circumferential direction of the pivot shaft 32. A hinge opening 84G is formed through the rear portion of the front outer peripheral wall 84F, and the hinge opening 84G opens rearward (see FIG. 8 ). Shaft insertion holes 84H are formed through the left and right side walls of the front hinge portion 84E. The shaft insertion holes 84H are arranged coaxially with the rotating shaft 32, and the left end of the rotating shaft 32 is inserted into the shaft insertion holes 84H. The shaft insertion holes 84H are arranged radially outward of the rotating shaft 32 with a predetermined gap therebetween.

[0066] The rear hinge portion 82H of the rear duct 82 is housed within the front hinge portion 84E, and the front end portion of the extending duct portion 82C of the rear duct 82 protrudes rearward from the hinge opening 84G. The communication hole 82K of the rear duct 82 opens toward the connecting duct portion 84B of the front hinge portion 84E, and the communication hole 82K connects the interior of the rear duct 82 to the interior of the front hinge portion 84E.

[0067] When the rear hinge portion 82H is housed in the front hinge portion 84E, the front outer peripheral wall 84F of the front hinge portion 84E is disposed radially outward of the rear outer peripheral wall 82J of the rear hinge portion 82H with a predetermined gap therebetween. Also, as shown in Fig. 8 and Fig. 11(B) , the rear outer peripheral wall 82J and the front outer peripheral wall 84F are disposed so as to at least partially overlap in the radial direction of the rotation shaft 32 at any position of the circular saw body 20 between the maximum cutting depth position and the minimum cutting depth position. That is, the communication hole 82K of the rear duct 82, which opens at a predetermined angle about the axis line AL, and the opening range of the hinge opening 84G of the front duct 84 are set so as not to overlap within a 360-degree range about the axis line AL. In other words, when viewed radially outward from the center of the inner cylinder 82L on the axis AL, the communicating holes 82K and the hinge openings 84G are configured so as not to overlap. In this embodiment, when viewed left and right in the maximum cutting depth state, the communicating holes 82K open within a range of 80 to 195 degrees from the axis AL, and the hinge openings 84G open within a range of 270 to 70 degrees from the axis AL. That is, in the maximum cutting depth state, the upper portion of the front outer peripheral wall 84F radially overlaps with the upper portion of the rear outer peripheral wall 82J within a 10-degree angle range, and the lower portion of the front outer peripheral wall 84F radially overlaps with the lower portion of the rear outer peripheral wall 82J within a 75-degree angle range. Therefore, in the maximum cutting depth state, the lower portion of the rear outer peripheral wall 82J extends deeper from the hinge openings 84G into the front hinge portion 84E than the upper portion.

[0068] The rear hinge portion 82H and the front hinge portion 84E form the lower end of the exhaust duct 80. That is, most of the flow path 80A through which the airflow AR passes within the exhaust duct 80 is located above the front hinge portion 84E and the rear hinge portion 82H. Furthermore, a portion of the flow path 80A (exhaust duct 80) is located above the pivot shaft 32. Specifically, a portion of the flow path 80A (exhaust duct 80) passes above the pivot shaft 32 in the front-to-rear direction. In other words, a portion of the flow path 80A (exhaust duct 80) is located above the pivot shaft 32 and overlaps with the pivot shaft 32 when viewed in the up-down direction. Furthermore, the rear hinge portion 82H and the front hinge portion 84E are disposed above the front end of the plate connecting portion 74C of the connecting plate 74 with a predetermined gap therebetween.

[0069] The outlet duct portion 84C extends forward from the upper end of the intermediate duct portion 84A and is disposed above the front bevel plate 71 and the front connecting plate portion 74A of the tilting mechanism 70 with a predetermined gap therebetween. The front end of the outlet duct portion 84C serves as an exhaust portion 84J, which is bent diagonally downward and forward and disposed in front of the upper outer periphery of the front bevel plate 71 (see FIGS. 8 and 9B). That is, the outlet duct portion 84C is disposed so as to straddle the front bevel plate 71 and the front connecting plate portion 74A. The position of the outlet duct portion 84C is set so that a portion of the outlet duct portion 84C is disposed above the front bevel plate 71 and the front connecting plate portion 74A in any position between the upright position and the tilted position of the circular saw body 20 (see FIGS. 3 and 10).

[0070] An exhaust port 84K is formed in the exhaust portion 84J of the outlet duct portion 84C, and the exhaust port 84K opens diagonally downward and forward in a side view (see FIG. 9B). The exhaust port 84K also opens diagonally downward and right in a front view (see FIG. 9A). Specifically, the exhaust port 84K opens toward the imaginary axis AX in a front view. This allows the airflow AR exhausted from the exhaust port 84K of the exhaust duct 80 to be blown toward the front side of the base 12 and toward the imaginary axis AX in a front view. More specifically, the airflow AR exhausted from the exhaust port 84K is blown toward the front region of the circular saw blade 14.

[0071] (Operation and Effect) Next, the operation and effect of this embodiment will be described.

[0072] When the circular saw body 20 is in the upright position, the circular saw blade 14 is arranged with the left-right direction being the thickness direction of the workpiece. When the operator operates the trigger 38, the motor 42 is driven to rotate the circular saw blade 14. Therefore, when cutting with the circular saw body 20 in the upright position, the cut surface of the workpiece is formed along a plane perpendicular to the left-right direction.

[0073] When the motor 42 is driven, the fan 50 rotates, generating an airflow AR that flows into the motor housing 26 through the intake port 26A of the motor housing 26. Specifically, as shown in FIG. 4 , the airflow AR inside the motor housing 26 is blown radially outward from the fan 50 and directed by the fan guide 52 toward the housing connection portion 24B. The airflow AR flowing into the housing connection portion 24B flows into the exhaust duct 80 through the inlet 82E of the exhaust duct 80. The airflow AR that flows into the exhaust duct 80 flows through the flow path 80A of the exhaust duct 80 and is exhausted from the exhaust port 84K of the exhaust duct 80 (see FIGS. 4 , 8 , 9A, and 9B ). Specifically, the airflow AR is exhausted from the exhaust port 84K of the exhaust duct 80 toward the front side of the base 12 and toward the imaginary axis AX. Therefore, the air flow AR is blown out in front of the circular saw blade 14, and chips and the like generated by the cutting process are blown away by the air flow AR, thereby preventing chips and the like from remaining on the workpiece.

[0074] Furthermore, when the cutting depth adjustment mechanism 30 is operated to switch the circular saw body 20 from the maximum cutting depth position to the minimum cutting depth position, the circular saw body 20 is rotated counterclockwise around the rotation shaft 32 as viewed from the left side. As a result, as shown in FIG. 11 , the rear duct 82 of the exhaust duct 80 rotates integrally with the circular saw body 20 around the rotation shaft 32. Specifically, the rear duct 82 rotates around the rear hinge portion 82H, which is the front end portion of the rear duct 82. As a result, the rear duct 82 rotates upward and away from the plate connecting portion 74C of the connecting plate 74 and the base 12. At this time, the rear duct 82 rotates relative to the front duct 84, and the position of the front duct 84 is maintained. Therefore, even when the circular saw body 20 is in the minimum cutting depth position, the position of the exhaust port 84K of the exhaust duct 80 relative to the base 12 does not change, and the air flow AR is exhausted from the exhaust port 84K to the front side of the base 12 and toward the imaginary axis AX.

[0075] Furthermore, when the tilting mechanism 70 is operated to tilt the circular saw body 20 from the upright position to the inclined position, the circular saw body 20 is rotated to the right about the imaginary axis AX. That is, as shown in FIG. 10 , the circular saw body 20 rotates integrally with the connecting plate 74, and the exhaust duct 80 rotates integrally with the circular saw body 20 and the connecting plate 74. The exhaust port 84K of the exhaust duct 80 opens toward the imaginary axis AX in a front view. Therefore, regardless of whether the circular saw body 20 is in the upright position or the inclined position, the exhaust port 84K of the exhaust duct 80 opens toward the imaginary axis AX in a front view. Therefore, even when the circular saw body 20 is tilted from the upright position to the inclined position, the airflow AR is exhausted from the exhaust port 84K of the exhaust duct 80 to the front side of the base 12 and toward the imaginary axis AX.

[0076] As described above, in the circular saw 10, the airflow AR generated by the fan 50 flows into the exhaust duct 80, and the airflow AR in the exhaust duct 80 is exhausted through the exhaust port 84K of the exhaust duct 80. The exhaust port 84K is located in front of the front bevel plate 71 of the tilting mechanism 70, and the airflow AR in the exhaust duct 80 is exhausted in front of the front bevel plate 71. This prevents the airflow AR exhausted through the exhaust port 84K from being blocked by the tilting mechanism 70. Therefore, the airflow AR exhausted through the exhaust port 84K can be blown forward of the base 12 to effectively remove chips and other debris generated during cutting. As a result, a decrease in workability of the circular saw 10 is suppressed. Furthermore, because a portion of the exhaust duct 80 overlaps with the front bevel plate 71 when viewed from the top-bottom direction, chips and other debris can be easily removed by the blower air (airflow) from above, preventing chips from scattering unnecessarily in the left-right direction, for example. Furthermore, because a portion of the exhaust duct 80 passes above the front bevel plate 71, there is less need to change the shape or position of the front bevel plate 71. This makes it possible to avoid problems such as increased costs and larger size.

[0077] Furthermore, the exhaust port 84K of the exhaust duct 80 opens toward the imaginary axis AX in a front view. This allows the exhaust port 84K to face the imaginary axis AX in a front view, as described above, regardless of whether the circular saw body 20 is in the upright position or the inclined position. Therefore, regardless of whether the circular saw body 20 is in the upright position or the inclined position, the airflow AR exhausted from the exhaust port 84K can be blown forward of the circular saw blade 14, thereby effectively removing chips and the like generated during cutting.

[0078] Furthermore, whether the circular saw body 20 is in the upright position or the inclined position, a portion of the outflow duct portion 84C of the front duct 84 is disposed above the front bevel plate 71 and the front connecting plate portion 74A with a predetermined gap therebetween. As a result, for example, if a downward external force is applied to the outflow duct portion 84C and the outflow duct portion 84C deforms downward, the outflow duct portion 84C comes into contact with the front bevel plate 71 and the front connecting plate portion 74A, limiting the downward deformation of the outflow duct portion 84C. In other words, the front bevel plate 71 and the front connecting plate portion 74A function as stoppers. This improves the protection performance of the front duct 84.

[0079] The exhaust duct 80 includes a rear duct 82 that forms the rear portion of the exhaust duct 80 and a front duct 84 that forms the front portion of the exhaust duct 80. A rear hinge portion 82H of the rear duct 82 and a front hinge portion 84E of the front duct 84 are connected to each other so as to be rotatable relative to each other about the axis 32A (see FIG. 8 ) of the rotation shaft 32 of the cutting depth adjustment mechanism 30, and form the lower end portion of the exhaust duct 80. As a result, when the circular saw body 20 is switched from the maximum cutting depth position to the minimum cutting depth position, the rear duct 82 rotates about the rear hinge portion 82H in a direction away from the base 12 and the connecting plate 74, as described above. Therefore, the rear duct 82 can be prevented from interfering with the base 12 or the connecting plate 74 at any position of the circular saw body 20 between the maximum cutting depth position and the minimum cutting depth position.

[0080] Furthermore, by having the rear hinge portion 82H of the rear duct 82 and the front hinge portion 84E of the front duct 84 form the lower end of the exhaust duct 80, it is possible to reduce the dead space between the rear hinge portion 82H and the front hinge portion 84E and the base 12, while concentrating and arranging most of the flow path 80A of the exhaust duct 80 above the rear hinge portion 82H and the front hinge portion 84E. This contributes to making the exhaust duct 80 more compact. Furthermore, because a portion of the flow path 80A (exhaust duct 80) passes above the pivot shaft 32 in the front-to-rear direction, it is easier to arrange the pivot shaft 32 on the lower side, and it is possible to make the structure around the pivot shaft 32 more compact. In this embodiment, a portion of the flow path 80A (exhaust duct 80) passes in the front-to-rear direction both above and below the pivot shaft 32, which makes it possible to prevent the length of the flow path 80A (exhaust duct 80) from changing at any position between the maximum cutting depth position and the minimum cutting depth position of the circular saw body 20. This also makes it easy to ensure the flow path area of ​​the flow path 80A.

[0081] The rear duct 82 includes a main duct portion 82A attached to the duct fitting 24K of the saw cover 24 and an extension duct portion 82C extending leftward from the front end of the main duct portion 82A. A rear hinge portion 82H is formed at the tip of the extension duct portion 82C. This allows the rear hinge portion 82H to be positioned on the left side of the support tube portion 24A of the saw cover 24, connecting the rear hinge portion 82H to the front hinge portion 84E. Furthermore, a portion of the exhaust duct 80 is vertically covered by the metal duct fitting 24K, thereby protecting the exhaust duct 80. The exhaust duct 80 does not extend straight forward from the duct connection hole 24F, but is offset to the right and partially supported by the saw cover 24 (duct fitting 24K). This makes it easier to check the cutting edge of the circular saw blade 14 through the space below the duct fitting portion 24K.

[0082] Furthermore, the rear duct 82 of the exhaust duct 80 has an illumination holding portion 82F, and the illumination lens 90 is held by the illumination holding portion 82F. This allows the exhaust duct 80 to be used to hold the illumination lens 90. Furthermore, the illumination lens 90 is sandwiched from both the left and right sides by the first duct member 82-1 and the second duct member 82-2 that make up the rear duct 82. Therefore, by assembling the first duct member 82-1 and the second duct member 82-2 together, the exhaust duct 80 can be formed while holding the illumination lens 90.

[0083] Furthermore, a rectifying cover portion 82G is provided at the rear end of the rear duct 82 of the exhaust duct 80. The rectifying cover portion 82G is disposed at the opening of the recess 24J of the housing connection portion 24B of the saw cover 24 and blocks the opening of the recess 24J. This prevents the airflow AR from entering the recess 24J and prevents the airflow AR from stagnating in the recess 24J. In other words, the airflow AR flowing into the housing connection portion 24B is rectified by the rectifying cover portion 82G and can flow into the inlet duct portion 82B of the exhaust duct 80. Furthermore, because the exhaust duct 80 is used to rectify the airflow AR within the housing connection portion 24B, this contributes to reducing the number of parts and assembly man-hours compared to when the rectifying cover portion 82G is configured separately from the exhaust duct 80.

[0084] Furthermore, the front duct 84 of the exhaust duct 80 is fixed to the front connecting plate 74A of the tilting mechanism 70. This allows the front duct 84 to move integrally with the connecting plate 74. That is, when the tilting mechanism 70 is activated, the circular saw body 20, the connecting plate 74, and the exhaust duct 80 can be rotated integrally about the imaginary axis AX. Furthermore, as described above, the exhaust port 84K of the exhaust duct 80 opens toward the imaginary axis AX in a plan view (viewed in the up-down direction). Therefore, the exhaust port 84K can be opened toward the imaginary axis AX whether the circular saw body 20 is in the upright position or the inclined position. In other words, when the tilting mechanism 70 is activated to tilt the circular saw body 20 from the upright position to the inclined position, the exhaust port 84K rotates about the imaginary axis AX. This prevents the opening direction of the exhaust port 84K from changing relative to the imaginary axis AX.

[0085] Furthermore, in the exhaust duct 80, the rear hinge portion 82H of the rear duct 82 is disposed inside the front hinge portion 84E of the front duct 84. Therefore, the communication hole 82K of the rear duct 82 is disposed inside the front hinge portion 84E. Therefore, the airflow AR can be efficiently discharged from the communication hole 82K into the flow path 80A of the front duct 84, and leakage of the airflow AR from the exhaust duct 80 can be suppressed.

[0086] That is, if a structure were adopted in which the front hinge portion 84E of the front duct 84 is disposed within the rear hinge portion 82H of the rear duct 82, the front hinge portion 84E would be disposed within the communication hole 82K of the rear duct 82. That is, the gap between the front hinge portion 84E and the rear hinge portion 82H is opened to the front side (i.e., downstream of the airflow AR) by the communication hole 82K. Therefore, there is a possibility that the airflow AR flowing through the gap between the front hinge portion 84E and the rear hinge portion 82H will leak out of the exhaust duct 80 through the communication hole 82K.

[0087] In contrast, in the present embodiment, the rear hinge portion 82H of the rear duct 82 is disposed within the front hinge portion 84E of the front duct 84. As a result, the gap between the front hinge portion 84E and the rear hinge portion 82H is opened to the rear (i.e., the upstream side of the airflow AR) by the hinge opening 84G. This prevents the airflow AR flowing forward from the communication hole 82K of the rear hinge portion 82H from entering the gap between the front hinge portion 84E and the rear hinge portion 82H and leaking from the hinge opening 84G. This allows the airflow AR to flow smoothly from the communication hole 82K into the flow path 80A of the front duct 84, thereby preventing the airflow AR from leaking from the exhaust duct 80. Furthermore, at any position between the maximum cutting depth position and the minimum cutting depth position of the circular saw body 20, the rear outer peripheral wall 82J and the front outer peripheral wall 84F are arranged so that at least a portion of them overlap in the radial direction of the pivot shaft 32, thereby preventing air flow AR from leaking to the outside from the hinge portion of the exhaust duct 80 and preventing foreign matter from entering the hinge portion from the outside.

[0088] Furthermore, the front outer peripheral wall 84F of the front hinge portion 84E of the front duct 84 is disposed radially outward of the rear outer peripheral wall 82J of the rear hinge portion 82H of the rear duct 82, with a predetermined gap therebetween. This prevents interference between the front hinge portion 84E and the rear hinge portion 82H when the cutting depth adjustment mechanism 30 is activated. Therefore, the rear duct 82 can be smoothly rotated relative to the front duct 84 when the cutting depth adjustment mechanism 30 is activated. Note that the front outer peripheral wall 84F and the rear outer peripheral wall 82J may be configured to be in partial or full contact with each other as long as this does not interfere with rotation. However, because the front duct 84 and the rear duct 82 are made of resin, direct contact may promote deterioration due to friction. Therefore, a structure that maintains a non-contact state is preferable.

[0089] Furthermore, the shaft insertion hole 84H of the front hinge portion 84E in the front duct 84 and the inner cylinder 82L of the rear hinge portion 82H in the rear duct 82 are disposed radially outward of the pivot shaft 32 with a predetermined gap therebetween. As a result, when a radial external force from the pivot shaft 32 is applied to the rear hinge portion 82H and the front hinge portion 84E, causing the rear hinge portion 82H and the front hinge portion 84E to deform in the radial direction of the pivot shaft 32, the inner cylinder 82L and the shaft insertion hole 84H come into contact with the outer periphery of the pivot shaft 32. As a result, radial deformation of the pivot shaft 32 at the rear hinge portion 82H and the front hinge portion 84E can be suppressed by the pivot shaft 32. Therefore, the protection performance of the front hinge portion 84E and the rear hinge portion 82H can be improved. Furthermore, since the pivot shaft 32 is configured to protrude (extend) leftward from the support tube portion 24A and thereby support (suppress movement of) the rear hinge portion 82H and the front hinge portion 84E, it is possible to support the exhaust duct 80 by utilizing the pivot shaft 32, which serves as a support shaft when rotating the circular saw body 20 relative to the base 12. This allows the number of parts to be reduced.

[0090] Furthermore, the front duct 84 is connected (fixed) to the connecting plate 74 so as to be movable integrally with it. As a result, compared to when the front duct 84 is fixed to the support plate 34, the connecting plate 74 (front connecting plate portion 74A) is larger in the vertical and horizontal directions, which provides a higher degree of freedom in setting the position where the front duct 84 is fixed, making it easier to position the front duct 84 (or a part thereof) in a desired position.

[0091] 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.

[0092] 10 Circular saw (work machine) 12 Base 14 Circular saw blade 20 Circular saw body 22 Housing 24 Saw cover (cover portion) 24B Housing connection portion 24J Recess 26 Motor housing 32 Rotating shaft 42 Motor 50 Fan 70 Tilting mechanism 71 Front bevel plate (front support portion) 73 Rear bevel plate (rear support portion) 74 Connecting plate (connecting portion) 80 Exhaust duct 82 Rear duct 82-1 First duct member 82-2 Second duct member 82A Main body duct portion (main body portion) 82C Extension duct portion (extension portion) 82G Rectification cover portion (rectification portion) 82H Rear hinge portion (rear connection portion) 82J Rear outer peripheral wall 84 Front duct 84E Front hinge portion (front connection portion) 84F Front outer peripheral wall 84K Exhaust port 90 Illumination lens (illumination portion) AR Air flow AX Virtual axis

Claims

1. A working machine comprising: a circular saw body including a motor, a fan that rotates when driven by the motor to generate an airflow, a housing that accommodates the motor and the fan, a circular saw blade that rotates when driven by the motor, and an exhaust duct into which the airflow inside the housing is introduced; a base provided on the underside of the housing; and a tilting mechanism that connects the circular saw body to the base and tilts the circular saw body relative to the base around an imaginary axis that extends in the front-to-back direction below the base, wherein the tilting mechanism has a front support part that is positioned on the front side of the circular saw body and fixed to the base, and the exhaust duct has an exhaust port that exhausts the introduced airflow in front of the front support part, and when the circular saw body is tilted relative to the base by the tilting mechanism, the exhaust port rotates around the imaginary axis.

2. The work machine described in claim 1, wherein the tilting mechanism allows the circular saw body to be tilted between an upright position in which the circular saw blade is positioned with the left-right direction as the thickness direction of the plate, and an inclined position inclined to one side in the left-right direction from the upright position, and wherein the exhaust port is open toward the imaginary axis in any position between the upright position and the inclined position of the circular saw blade.

3. A work machine according to claim 2, wherein a portion of the exhaust duct is disposed above the front support portion when the circular saw blade is in any position between the upright position and the inclined position.

4. The tilting mechanism has: a rear support part located at the rear of the circular saw body and fixed to the base; and a connecting part connected to the circular saw body and connected to the front support part and the rear support part; the front end of the circular saw body is rotatably connected to the connecting part by a rotation axis whose axial direction is in the left-right direction; and the exhaust duct is comprised of: a rear duct that forms the rear part of the exhaust duct, has a rear connecting part at its front end, is attached to the housing so as to be movable as one unit, and into which the air flow flows; and a front duct that forms the front part of the exhaust duct, has a front connecting part at its rear end, and exhausts the air flow; and the rear connecting part and the front connecting part are connected so as to be able to rotate relative to each other about the axis of the rotation axis, and part of the air flow passage in the exhaust duct passes in the front-to-back direction above the rotation axis.

5. A work machine comprising: a motor; a fan that rotates when driven by the motor to generate an air flow; a housing that accommodates the motor and the fan; a base provided below the housing; a circular saw blade that rotates when driven by the motor; and an exhaust duct into which the air flow inside the housing is introduced, wherein the exhaust duct includes: a rear duct that forms a rear part of the exhaust duct, has a rear connection part at a front end, is attached to the housing so as to be movable integrally, and into which the air flow is introduced; and a front duct that forms a front part of the exhaust duct, has a front connection part at a rear end, and exhausts the air flow to the front side of the housing, wherein the housing is rotatably connected to the base by a rotating shaft whose axial direction is in the left-right direction, and the rear connection part and the front connection part are connected so as to be capable of relative rotation about the axis of the rotating shaft, and a part of the air flow passage in the exhaust duct passes above the rotating shaft in the front-to-rear direction.

6. A work machine as described in claim 5, wherein the housing has a cover portion that covers the circular saw blade from above, and the rear duct is configured to include a main body portion attached to the side of the cover portion, and an extension portion that extends from the main body portion to the opposite side of the circular saw blade and has the rear connection portion at its tip.

7. A work machine as described in claim 4 or claim 5, which is provided with an illumination unit that irradiates light to the outside of the housing, the rear duct being composed of a first duct member and a second duct member, and the illumination unit being held by the first duct member and the second duct member.

8. A work machine according to claim 6, wherein a recess is formed inside the housing, and a part of the rear duct covers the recess to prevent the air flow from entering the recess.

9. A work machine as described in claim 8, wherein the housing has a motor housing located on the left side of the cover portion and accommodating the motor, the cover portion has a housing connection portion to which the motor housing is connected, and the recess is formed in the housing connection portion.

10. A work machine comprising: a motor; a fan that rotates when driven by the motor to generate an airflow; a housing that accommodates the motor and the fan; a base provided on the underside of the housing; and an exhaust duct into which the airflow inside the housing flows, wherein the exhaust duct has a straightening section disposed inside the housing, and the straightening section straightens the airflow inside the housing and causes it to flow into the exhaust duct.

11. The work machine described in claim 1, wherein the tilting mechanism has a rear support part disposed on the rear side of the circular saw body and fixed to the base, and a connecting part connected to the circular saw body and connected to the front support part and the rear support part, and the exhaust duct is fixed to the connecting part.

12. A work machine according to claim 4 or 5, wherein the rear connection portion is disposed inside the front connection portion.

13. A work machine as described in claim 12, wherein the front connection portion has a front outer peripheral wall extending along the circumferential direction of the rotating shaft, and the rear connection portion has a rear outer peripheral wall extending along the circumferential direction of the rotating shaft, and the front outer peripheral wall is arranged radially outward of the rear outer peripheral wall with a predetermined gap therebetween.

14. A work machine according to claim 4 or claim 5, wherein the rear connection portion and the front connection portion are arranged radially outward of the pivot shaft.

15. A working machine comprising: a circular saw body comprising a motor, a fan that rotates when driven by the motor to generate an air flow, a housing that accommodates the motor and the fan, and an exhaust duct into which the air flow inside the housing flows; a base provided on the underside of the housing; and a tilting mechanism that connects the circular saw body to the base and tilts the circular saw body relative to the base, wherein the tilting mechanism has a front support part that is positioned on the front side of the circular saw body and fixed to the base, and the front support part is provided with a guide part that guides the tilt of the circular saw body relative to the base, and a part of the exhaust duct overlaps with the guide part when viewed in the vertical direction, and the exhaust duct has an exhaust port that exhausts the flowed-in air flow in front of the front support part.

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