Work machine

Abstract

The present invention suppresses a deterioration in work efficiency. In a tilting mechanism 60 of a circular saw 10, a front tilting mechanism section 70 includes a front tilting plate 72 connected to a circular saw body 20 and a front guide 71 for guiding rotation of the front tilting plate 72, and a rear tilting mechanism section 80 includes a rear tilting plate 82 connected to the circular saw body 20 and a rear guide 81 for guiding rotation of the rear tilting plate 82. When the circular saw body 20 is tilted (rotated) from an upright position to a tilting position, the circular saw body 20 as a whole is separated from the base 12 along a side surface of a circular saw blade 14 by the front guide 71 and the rear guide 81. Thus, even when the circular saw body 20 is tilted from the upright position, downward displacement of a washer member 16 for connecting the circular saw blade 14 to an output shaft 44 can be suppressed.

Description

Work equipment

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

[0002] The portable cutting machine (working machine) described in Patent Document 1 below has a main body having a circular saw blade, which is rotatably supported on a base by a tilting mechanism around a connecting member (a pivot axis extending in the front-rear direction). This allows the operator to tilt the main body relative to the base to change the angle of the cutting surface of the workpiece. Patent Document 2 below also discloses a working machine compatible with a member (guide rail) that assists in linear cutting. The working machine of Patent Document 2 also has a tilting mechanism similar to that of Patent Document 1, but does not have a mechanical pivot axis, but instead has a virtual pivot axis (tilting axis V). The tilting axis V in Patent Document 2 is virtual because the tilting axis needs to be set below the underside of the base to accommodate cutting with a guide rail. Furthermore, the working machine of Patent Document 2 improves workability by aligning the position of the virtual tilting axis with the end of the guide rail.

[0003] International Publication No. 2017 / 187894 Japanese Patent Application Laid-Open No. 2017-196853

[0004] When the main body is tilted, the washer member, which serves as a holding member for holding the circular saw blade to the main body, is displaced downward depending on the position of the rotation axis when the main body is tilted. Therefore, to prevent interference between the washer member and the workpiece when the main body is not tilted (at a right angle), it is necessary to position the washer member somewhat above the workpiece. However, in this case, the cutting depth into the workpiece when the main body is not tilted is reduced, which may reduce the operability of the portable cutting machine.

[0005] On the other hand, by setting the rotation center axis of the main body to the left of the circular saw blade when viewed from the front, the washer member displaces upward when the main body is tilted, thereby preventing interference between the washer member and the workpiece when the main body is tilted. However, even in this case, the cutting depth into the workpiece may be reduced, potentially reducing the operability of the portable cutting machine. Some work machines are designed to be tiltable in the reverse direction. In this case, the washer member displaces downward in the tilted state, but displaces upward in the reverse tilted state. Therefore, the cutting depth is reduced during reverse tilting. Another issue is that tilting requires relative movement between the base and the main body, and the base and main body must be designed to allow this relative movement. For example, in a work machine, auxiliary functions such as a lighting device or a blower mechanism can improve workability. However, when attempting to locate these auxiliary functions in a location where they are most effective, they may be placed in a less effective location because the placement interferes with tilting (relative movement) or the mechanical structure of the tilting mechanism. This results in reduced workability. Another issue is that in a configuration where tilting is achieved by a guide shaft moving within a guide groove, as described in Cited Document 1, excessive contact between the guide groove and the guide shaft makes smooth tilting difficult, resulting in reduced workability.

[0006] In consideration of the above, an object of the present invention is to provide a work machine that can suppress a decrease in workability.

[0007] One or more embodiments of the present invention include a main body having a motor and an output shaft whose axial direction is in the left-right direction and which rotates when driven by the motor; a circular saw blade connected to the output shaft so as to be rotatable together with the output shaft and extending in the front-rear direction; a washer member for holding the circular saw blade on the output shaft; a base disposed below the main body and having an insertion portion through which the circular saw blade is inserted; and a tilting mechanism configured to tilt the main body relative to the base from a non-tilting state in which the output shaft extends in the left-right direction by a predetermined angle to one side in the left-right direction to a tilting state, the tilting mechanism being provided on one of the main body and the base and having a guide portion. The work machine has a guide member and a guided portion that is provided on the other of the main body portion and the base, operates inside the guide portion, and has its movement guided by the guide portion.In both the non-tilting state and the tilting state, the circular saw blade is configured to overlap with a virtual axis extending in the front-to-rear direction at a position below the washer member, and in a virtual state in which the main body portion in the non-tilting state is rotated a predetermined angle around the virtual axis, at least a portion of the washer member is positioned below the underside of the base, and when transitioning from the non-tilting state to the tilting state, the tilting mechanism operates the washer member above the underside of the base.

[0008] One or more embodiments of the present invention are directed to a work machine in which at least a portion of the washer member is located inside the insertion portion in at least one of the non-tilted state and the tilted state.

[0009] In one or more embodiments of the present invention, the guide portion is formed in an arc shape, and the radius of curvature of the guide portion is set to be large at least in a portion thereof.

[0010] One or more embodiments of the present invention are a work machine in which a pair of guide portions are formed on the guide member, and one of the guide portions is located radially outside the other of the guide portions.

[0011] In one or more embodiments of the present invention, the guided portion includes a pair of guide shafts whose axial direction is the front-to-rear direction, and the guide shafts are movably inserted into each of the pair of guide portions.

[0012] One or more embodiments of the present invention are directed to a work machine in which the guide shaft is formed in a cylindrical shape.

[0013] One or more embodiments of the present invention are directed to a work machine, wherein the guided portion is provided with a bearing member, and the bearing member is movably inserted into the guide portion.

[0014] In one or more embodiments of the present invention, the guide portion and the guided portion are each provided in pairs, the pair of guided portions are arranged so that they are spaced apart in a direction perpendicular to the fore-and-aft direction, and the bearing member is provided on the side of the pair of guided portions that is located on the outer side in at least the direction perpendicular to the fore-and-aft direction.

[0015] One or more embodiments of the present invention are a work machine in which the guide portion and the guided portion are each provided in pairs, the guide portion is formed in an arc shape, the guide member has an arc-shaped fixed hole formed in it separately from the guide portion, the tilting mechanism has a fixed shaft inserted through the fixed hole and a fixed member provided at the tip of the fixed shaft and operable by an operator, the operator can allow or restrict tilting of the main body portion relative to the base by operating the fixed member, and the fixed hole is configured to be located between the pair of guide portions in a direction perpendicular to the fore-and-aft direction.

[0016] In one or more embodiments of the present invention, the tilting mechanism has a regulating member configured to be rotatable around the axis, and the regulating member is configured to guide the movement of the main body portion so as to allow relative movement in a predetermined direction with respect to the regulating member.

[0017] One or more embodiments of the present invention are a work machine in which a regulating hole extending in a direction intersecting the extension direction of the output shaft is formed in the regulating member, and a part of the main body is inserted through the regulating hole so that the regulating member and the main body engage in the extension direction of the output shaft, thereby regulating the relative movement of the main body with respect to the regulating member in a direction intersecting the specified direction.

[0018] One or more embodiments of the present invention are a work machine in which the regulating member is made of a material having higher mechanical strength than the guide member, is configured to be impregnated with lubricating oil, or is formed by sintering.

[0019] One or more embodiments of the present invention are a work machine comprising: a main body having a motor and an output shaft that rotates when driven by the motor; a circular saw blade connected to the output shaft so as to rotate integrally with the output shaft; a washer member for holding the circular saw blade on the output shaft; a base arranged below the main body and having an insertion portion through which the circular saw blade is inserted; and a tilting mechanism that can tilt the main body from a non-tilted state to a tilted state tilted 45 degrees relative to the base, wherein the lower end position of the washer member in the tilted state is positioned at the same position as or higher than the lower end position of the washer member in the non-tilted state.

[0020] One or more embodiments of the present invention are a working machine comprising: a main body having a motor and an output shaft that rotates when driven by the motor; a circular saw blade connected to the output shaft so as to rotate integrally with the output shaft; a base arranged below the main body and having an insertion portion through which the circular saw blade is inserted; and a tilting mechanism that can tilt the main body from a non-tilted state to a tilted state tilted 45 degrees relative to the base, wherein the circular saw blade is connected to the output shaft via a washer member, and the intersection of the circular saw blade and a horizontal plane located below the washer member and parallel to the underside of the base is configured to be in approximately the same position when the main body is in the non-tilted state as when the main body is in the tilted state, and the difference in the vertical direction between the lower end position of the washer member in the non-tilted state and the lower end position of the washer member in the tilted state is configured to be equal to or less than the vertical distance between the lower end of the washer member in the non-tilted state and the underside of the base.

[0021] One or more embodiments of the present invention are a working machine comprising: a main body having a motor and an output shaft that rotates when driven by the motor; a circular saw blade connected to the output shaft so as to rotate integrally with the output shaft; a base arranged below the main body and having an insertion portion through which the circular saw blade is inserted; and a tilting mechanism capable of tilting the main body from a non-tilting state to a tilting state relative to the base, wherein the circular saw blade is connected to the output shaft via a washer member, and the intersection of the circular saw blade and a horizontal plane located below the washer member and parallel to the underside of the base is configured to be in approximately the same position when the main body is in the non-tilting state as when the main body is in the tilting state, and wherein the lower end of the washer member moves continuously upward or downward when the main body is tilted from the non-tilting state to the tilting state.

[0022] According to one or more embodiments of the present invention, it is possible to suppress a decrease in workability.

[0023] 1 is a plan view showing 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 right side; a cross-sectional view (cross-sectional view along line 3-3 in FIG. 2) showing the interior of the circular saw shown in FIG. 2, as seen from the front side; a cross-sectional view (cross-sectional view along line 3-3 in FIG. 2) showing the interior of the circular saw body shown in FIG. 3, as seen from the front side, when tilted to the tilted position; a plan view of the tilting mechanism shown in FIG. 1; an exploded perspective view of the front tilting mechanism in the tilting mechanism shown in FIG. 5, as seen from the diagonally rear left side; an exploded perspective view of the front tilting mechanism in the tilting mechanism shown in FIG. 5, as seen from the diagonally front right side; an exploded perspective view of the rear tilting mechanism in the tilting mechanism shown in FIG. 5, as seen from the diagonally front right side; a cross-sectional view (cross-sectional view along line 9-9 in FIG. 2) showing the interior of the front tilting mechanism shown in FIG. 2, as seen from the rear side; and a cross-sectional view corresponding to FIG. 9, showing the interior of the front tilting mechanism when the circular saw body is tilted to the tilted position. (A) is a cross-sectional view from the front (cross-sectional view along line 11A-11A in Figure 2) showing the inside of the rear tilting mechanism shown in Figure 2, and (B) is a cross-sectional view corresponding to (A) showing the inside of the rear tilting mechanism when the circular saw body is tilted to the tilted position.

[0024] 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 RH shown as appropriate in the drawings respectively indicate the upper side, front side, and right 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.

[0025] 1 and 2, the circular saw 10 is configured as a power tool for cutting workpieces. The circular saw 10 includes a base 12 and a circular saw body 20 as a main body. The circular saw 10 also has a tilting mechanism 60 that connects the circular saw body 20 to the base 12 so that the circular saw body 20 can tilt. Each component of the circular saw 10 will be described below.

[0026] (Regarding the base 12) As shown in FIGS. 1 to 5, the base 12 is made of metal and is formed into a generally rectangular plate shape 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 a workpiece and moved forward. An insertion hole 12A for accommodating the circular saw blade 14 is formed through the right portion of the base 12. The insertion hole 12A is generally rectangular with its length extending forward and backward and has a width extending vertically. The circular saw blade 14 is generally disc-shaped with its thickness extending horizontally, and the center of the circular saw blade 14 is fixed to an output shaft 44 of the drive mechanism 40 (described later) so as to be rotatable together with the blade. A portion of the circular saw blade 14 is disposed within the insertion portion 12A, with the upper portion of the circular saw blade 14 protruding upward from the base 12 and the lower end portion of the circular saw blade 14 protruding downward from the base 12 (base lower surface 12C). The base 12 is provided with an engagement portion 12B for engaging with a guide rail as shown in the patent document. In other words, the circular saw 10 is configured to be adapted to engage with a guide rail.

[0027] (Circular Saw Body 20) As shown in FIGS. 1 to 3, the circular saw body 20 includes a housing 22, a battery 32, and a drive mechanism 40.

[0028] (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 covers the circular saw blade 14, a motor housing 26 that houses a drive mechanism 40 (described later), and a battery holder 28 to which a battery 32 is attached.

[0029] 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 a thickness extending in the left-right direction and a convex shape extending upward and a concave shape opening downward. The upper part of the circular saw blade 14 is housed in and covered by the saw cover 24.

[0030] The saw cover 24 is connected to the base 12 by the cutting depth adjustment mechanism 30 via a tilting mechanism 60 (described later). Specifically, the front end of the saw cover 24 is connected to the front end of the tilting mechanism 60 by a front connecting mechanism 30A of the cutting depth adjustment mechanism 30, and the rear end of the saw cover 24 is connected to the rear end of the tilting mechanism 60 by a rear connecting mechanism 30B of the cutting depth adjustment mechanism 30. In this way, the circular saw body 20 is connected to the base 12. A cover connecting portion 24A is provided on the left side of the saw cover 24. The cover connecting portion 24A is formed in a substantially cylindrical shape with its axial direction extending in the left-right direction and protrudes to the left from the saw cover 24.

[0031] The motor housing 26 is generally box-shaped and opens to the right. The motor housing 26 is disposed to the left of the cover connecting portion 24A of the saw cover 24 and is fastened to the cover connecting portion 24A at a position not shown.

[0032] The battery holder 28 extends rearward from the top of the motor housing 26. A battery 32 is attached to the battery holder 28 from the rear, and is disposed below the battery holder 28 and at the rear of the motor housing 26. The battery 32 is electrically connected to a controller (not shown) and a motor 42 of a drive mechanism 40, which will be described later.

[0033] A handle portion 28A is provided on the upper side of the battery holder 28. When viewed from the right side, the handle portion 28A is formed in a generally U-shape that opens diagonally downward and forward, with the front end of the handle portion 28A connected to the motor housing 26 and the rear end of the handle portion 28A connected to the battery holder 28. A trigger 34 is provided on the handle portion 28A so that it can be pulled. Pulling (pushing) the trigger 34 presses a switch (not shown) housed inside the handle portion 28A. This switch is electrically connected to a controller, and a drive mechanism 40 (described later) is activated in response to operation of the trigger 34.

[0034] (Regarding the drive mechanism 40) As shown in Fig. 3, the drive mechanism 40 includes a motor 42 and an output shaft 44. The motor 42 is configured as a brushless motor, is housed in the motor housing 26, and is electrically connected to the controller. The motor 42 has a rotation shaft 42A whose axial direction is in the left-right direction, and the rotation shaft 42A is rotatably supported by a motor bearing (not shown) fixed to the motor housing 26. A pinion gear is formed on the right end of the rotation shaft 42A.

[0035] The output shaft 44, with its axial direction extending in the left-right direction, is disposed below the right end of the rotating shaft 42A and is disposed within the cover connecting portion 24A of the saw cover 24. The left end of the output shaft 44 is rotatably supported by a metal bearing 46 fixed to the cover connecting portion 24A, and the left-right intermediate portion of the output shaft 44 is rotatably supported by a bearing 48 fixed to the cover connecting portion 24A. An output gear 50 is provided at the left-right intermediate portion of the output shaft 44 so as to be integrally rotatable, and the output gear 50 is connected to a pinion gear of the rotating shaft 42A by a transmission mechanism (not shown).

[0036] The center of the circular saw blade 14 is fixed to the right end of the output shaft 44 by a fixing bolt 52. Specifically, the center of the circular saw blade 14 is sandwiched from the outside in the left-right direction by a washer member 16 serving as a holding member for holding the circular saw blade 14, and the washer member 16 is fastened and fixed to the output shaft 44 by the fixing bolt 52. As a result, when the motor 42 is driven, the output shaft 44 and the circular saw blade 14 are configured to rotate to one side about the axis of the output shaft 44. Furthermore, the lower end of the washer member 16 is located within the insertion portion 12A of the base 12 (within the vertical width range of the insertion portion 12A).

[0037] The lower part of the circular saw blade 14 is covered by a protective cover 54. When viewed from the right side, the protective cover 54 is formed in a generally semicircular shape that is convex downward and concave upward. The protective cover 54 is connected to the output shaft 44 so as to be rotatable about the axis of the output shaft 44. The protective cover 54 is biased about the axis of the output shaft 44 by a biasing spring (not shown) and is held in the position shown in FIG. 2. When cutting with the circular saw 10, the protective cover 54 rotates about the axis of the output shaft 44 against the biasing force of the biasing spring due to the workpiece, exposing the cutting portion of the circular saw blade 14.

[0038] (Regarding the Tilting Mechanism 60) As shown in FIGS. 1, 2, and 5 to 11, the working machine of this embodiment has a tilting mechanism 60 that changes the relative position of the circular saw body 20 and the base 12 to tilt (tilt) the circular saw blade 14 relative to the base 12. Specifically, the tilting mechanism 60 is configured to rotate the circular saw body 20 between an upright position (a non-tilted position, shown in FIGS. 1 to 3) and a tilted position (a position shown in FIG. 4) tilted approximately 45 degrees to the right from the upright position. When the intersection of the circular saw blade 14 (left side) and the horizontal plane GB in the non-tilted state (right-angled state) is defined as an axis AL, the tilting mechanism 60 is configured to tilt the circular saw body 20 relative to the base 12 without changing the position of the axis AL. The lower surface of the attachable guide rail is configured to be flush with the horizontal plane GB. That is, the axis AL is approximately the same as the position where the circular saw blade 14 intersects with the upper surface of the workpiece during cutting using the guide rail. The axis AL is not an axis that actually exists as an object, unlike the imaginary tilting axis shown in Patent Document 2. Apparently, the tilting mechanism 60 can be said to be a mechanism that rotatably connects the circular saw body 20 to the base 12 about an imaginary (virtual) axis AL (see Figures 9 to 11) extending in the front-to-rear direction, but the position of the axis AL (the intersection of the circular saw blade 14 and the horizontal plane GB) with respect to the circular saw body 20 changes relatively as the circular saw blade 14 tilts (details will be described later).

[0039] 5, the tilting mechanism 60 is provided on the upper side of the base 12, spanning from the front portion to the rear portion. The tilting mechanism 60 includes a front tilting mechanism 70 that forms the front end of the tilting mechanism 60, and a rear tilting mechanism 80 that forms the rear end of the tilting mechanism 60, and the front tilting mechanism 70 and the rear tilting mechanism 80 are connected to each other so that they operate simultaneously.

[0040] (Regarding the front tilting mechanism 70) As shown in Figures 5 to 7, 9, and 10, the front tilting mechanism 70 is composed of a front guide 71 as a guide member, a front tilting plate 72 as a movable member, and a front link 78 as a regulating member.

[0041] (Regarding the Front Guide 71) The front guide 71 is made of metal (aluminum in this embodiment) and is formed as a generally rectangular plate with its thickness extending in the front-to-rear direction. A guide fixing portion 71A that protrudes outward in the left-to-right direction is provided at the lower end of the front guide 71. The front guide 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 by a fixing screw SC1. The upper surface of the front guide 71 slopes upward in a curved manner toward the right when viewed from the rear. The axis AL is located below the right portion of the front guide 71.

[0042] An accommodation recess 71B for accommodating a front link 78 (described later) is formed on the rear surface of the front guide 71. The accommodation recess 71B is formed in a concave shape that is open to the rear, extends in the rotation direction of the circular saw body 20 (see the directions of arrows A and B in FIGS. 9 and 10 ) when viewed from the rear, and slopes upward in a curved manner toward the right. The right end of the accommodation recess 71B is open to the right, and the left end of the accommodation recess 71B is open diagonally downward to the left.

[0043] An inner guide groove 71C is formed on the rear surface of the front guide 71 at a radially inner portion of the accommodation recess 71B as a guide groove for guiding an inner guide shaft 73 (described later). The inner guide groove 71C is formed as a groove that is open to the rear. When viewed from the rear, the inner guide groove 71C extends in a curved (arcuate) shape along the rotation direction of the circular saw body 20. As will be described in detail later, the inner guide groove 71C is configured so that the curvature (radius of curvature) of at least a portion of the inner guide groove 71C changes. That is, in the non-tilted state (right-angled state) shown in FIG. 9 , the radius of curvature of the inner guide groove 71C about the axis AL increases from the lower end (one longitudinal end, which is also the left end) of the inner guide groove 71C to the upper end (the other longitudinal end, which is also the right end) of the inner guide groove 71C. An end face 71C1 of the lower end of the inner guide groove 71C is inclined toward one side in the longitudinal direction of the inner guide groove 71C as it approaches the rear side (the opening side of the inner guide groove 71C).

[0044] An outer guide groove 71D is formed on the rear surface of the front guide 71, radially outward of the accommodating recess 71B and radially outward of the inner guide groove 71C, as a guide groove for guiding the outer guide shaft 74 (described later). The outer guide groove 71D is formed as a groove that opens toward the rear. When viewed from the rear, the outer guide groove 71D extends parallel to the inner guide groove 71C. The outer guide groove 71D is curved in a generally arc shape centered on the axis AL. As will be described in detail later, the outer guide groove 71D is configured so that its curvature (radius of curvature) varies at least in part. That is, the radius of curvature of the outer guide groove 71D centered on the axis AL increases from the lower end (one longitudinal end, which is also the left end) of the outer guide groove 71D to the upper end (the other longitudinal end, which is also the right end). The groove width of the outer guide groove 71D is wider than the groove width of the inner guide groove 71C. Furthermore, an end face 71D1 of the lower end of the outer guide groove 71D is inclined toward one side in the longitudinal direction of the outer guide groove 71D as it approaches the rear side (the opening side of the outer guide groove 71D).

[0045] A fixing hole 71E is formed through the front guide 71 between the inner guide groove 71C and the outer guide groove 71D. A fixing shaft 76, which will be described later, is inserted through the fixing hole 71E. The fixing hole 71E extends parallel to the inner guide groove 71C and the outer guide groove 71D in rear view. The radius of curvature of the fixing hole 71E increases from the bottom end to the top end of the fixing hole 71E.

[0046] 9 and 10 respectively show point CA1, which is the center position of the outer guide shaft 74, point CB1, which is the center position of the inner guide shaft 73, and point CC1, which is the center position of the fixed shaft 76, in the right-angle state (non-tilted). Similarly, point CA2, which is the center position of the outer guide shaft 74, point CB2, which is the center position of the inner guide shaft 73, and point CC2, which is the center position of the fixed shaft 76, in the tilted state (45-degree tilted state). Furthermore, arc TA, which is the trajectory of the center position of the outer guide shaft 74, arc TB, which is the trajectory of the center position of the inner guide shaft 73, and arc TC, which is the trajectory of the center position of the fixed shaft 76, are shown. Each of the arcs TA, TB, and TC corresponds to a partial arc of a predetermined ellipse (elliptical arc). The center positions of the outer guide shaft 74, inner guide shaft 73, and fixed shaft 76 move between points CA1, CB1, and CC1 and points CA2, CB2, and CC2. However, in Figures 9 and 10, the arcs (TA, TB, and TC) that form the trajectories are depicted as overrunning. As shown in the figures, arc TA gradually moves away (radially) from the axis AL. That is, as described above, arc TA starts at CA1 and gradually increases in radius of curvature (decreases in curvature). The same is true for arcs TB and TC. Arcs TA, TB, and TC are also lines connecting the center positions in the width direction (radially) of the respective guide grooves (71C, 71D, and 71E).

[0047] 9 and 10 show points CA', CB', CC', arc TA', arc TB', and arc TC' as comparative examples (conventional examples) to points CA2, CB2, CC2, arc TA, arc TB, and arc TC. Points CA', CB', and CC' are the center positions of the outer guide shaft 74, inner guide shaft 73, and fixed shaft 76 in the tilted state when the radius of curvature of each guide groove (71C, 71D, 71E) is constant. Arcs TA', TB', and TC' are the orbits through which the center positions of the outer guide shaft 74, inner guide shaft 73, and fixed shaft 76 pass when the radius of curvature of each guide groove (71C, 71D, 71E) is constant. The arcs TA', TB', and TC' are parallel to each other and are similar to partial arcs of a perfect circle centered on a predetermined axis AL. Point CA2, which is the end point of the outer guide shaft 74, is located above point CA'. In other words, the position of the guide shaft in the tilted state is located higher than in the conventional configuration. As shown in the figure, the arcs TA, TB, and TC are longer than the conventional arcs TA', TB', and TC'. Therefore, if the present invention (a configuration in which the guide groove is an arc with a gradually increasing radius of curvature) is adopted, the front guide 71 may become larger than in the conventional configuration.

[0048] 9 and 10 show lines L1 and L2 passing through the axis AL. Line L1 is inclined at a 45-degree angle with respect to the left-right direction (up-down direction). Line L2 extends parallel to the up-down direction. That is, lines L1 and L2 intersect at a 45-degree angle. When the circular saw body 20 is in the upright position (right-angled state), points CA1, CB1, and CC1 are located on line L1 as viewed from the rear. Also, as shown in the figures, when the circular saw body 20 is in the tilted state (tilted 45 degrees), the centers of the outer guide shaft 74, inner guide shaft 73, and fixed shaft 76, which would conventionally be located on line L2, are shifted to the upper right.

[0049] Figure 9 shows the vertical distance S1 between the lower end of the washer member 16 and the underside of the base 12 in the upright position (right-angle position). Figure 10 also shows the vertical distance S2 between the lower end of the washer member 16 and the underside of the base 12 in the tilted position (45-degree tilt position) in addition to the distance S1. Both Figures 9 and 10 show the axis AL (the intersection of the circular saw blade 14 and the horizontal plane GB) for each position. In Figure 10, the position of the axis AL relative to the circular saw body 20 in the position shown in Figure 9 is shown as AL'. Figure 9 also shows the position of the washer member 16 in a virtual state (virtual state) in which the circular saw body 20 in the upright position (upright position) is tilted 45 degrees about the axis AL relative to the base 12. In other words, the virtual position 16' is the position of the washer member 16 in the tilted state when the virtual tilt axis is fixed, as in the conventional case. In other words, the virtual position 16' is the position of the washer member 16 in the tilted state when the curvature radius of each guide groove (71C, 71D, 71E) is constant. That is, in this embodiment, the cutting depth in the upright position is set so that, in the conventional configuration (where the virtual tilting axis is fixed), at least a portion of the washer member 16 is positioned below the base undersurface 12C in the tilted state. Furthermore, in this embodiment, to accommodate cutting using a guide rail, the intersection point (axis AL) between the circular saw blade 14 and the horizontal plane GB remains the same in the upright position and the tilted position. In other words, in both the upright position and the tilted position, a portion of the circular saw blade 14 passes through the virtual axis (axis AL). Therefore, in the tilted position, the intersection point between the circular saw blade 14 and the base undersurface 12C moves in the tilting direction (to the right) of the circular saw body 20 when viewed from the rear. Due to the change in the radius of curvature of each guide groove (71C, 71D, 71E) described above, the circular saw body 20 moves away from the base 12 along the planar direction of the circular saw blade 14 as it moves from the upright position (non-tilted state) to the tilted position. As a result, the position of the axis AL relative to the circular saw body 20 changes between the upright position and the tilted position. Specifically, as shown in FIG. 10 , the axis AL in the tilted position is farther away from the washer member 16 (the center of the circular saw blade 14) than the axis AL′ in the upright position. Therefore, the cutting depth changes between the upright position and the tilted position.In the configuration shown in Figures 9 and 10, the cutting depth is large in the upright position and small in the tilted position. That is, according to this embodiment, the cutting depth is changed by guiding the guide shaft along the guide groove depending on the shape of the guide groove. Specifically, by adjusting the curvature radius of the guide groove, the cutting depth becomes shallower with tilting (the amount of protrusion of the circular saw blade 14 downward from the base undersurface 12C decreases). In this embodiment, distance S2 is configured to be larger than distance S1. Specifically, distance S1 is 1 mm and distance S2 is 1.5 mm. Therefore, distance S2 is 0.5 mm larger than distance S1. In other words, the movement of the lower end position of the washer member 16 with tilting is 0.5 mm, which is less than distance S1. In this manner, the lower end of the washer member 16 gradually moves upward from the undersurface 12C of the base 12 with tilting. The lower end of the washer member 16 does not move downward during the transition from the upright state to the tilted state. In other words, in this embodiment, the lower end of the washer member 16 moves continuously upward during the transition from the upright state to the tilted state. The amount of movement of the lower end of the washer member 16 accompanying tilting is preferably equal to or less than the vertical distance (distance S1) between the lower end of the washer member 16 in the upright position (non-tilted state) and the base undersurface 12C. This configuration allows the washer member 16 to operate above the base undersurface 12C, even if the cutting depth in the upright state is increased to such an extent that a portion of the washer member 16 would be positioned below the base undersurface 12C during tilting, as shown in virtual position 16' in FIG. 9 , in a conventional configuration (fixed virtual shaft).

[0050] (Regarding the Front Tilting Plate 72) The front tilting plate 72 is made of metal (aluminum in this embodiment). The front tilting plate 72 is formed in a generally elongated plate shape with its thickness in the front-to-rear direction and extending in the direction of rotation of the circular saw body 20, and is disposed adjacent to the rear side of the front guide 71. A plate fixing portion 72A that is raised one step toward the rear is formed in the approximate center of the rear surface of the front tilting plate 72, and the plate fixing portion 72A is fastened and fixed to the front connecting mechanism 30A of the cutting depth adjustment mechanism 30. In this way, the front tilting plate 72 is connected to the front end of the circular saw body 20.

[0051] An inner guide shaft 73 is provided as a guide shaft on the radially inner portion of the front tilting plate 72 at a position corresponding to the inner guide groove 71C of the front guide 71. The inner guide shaft 73 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction. The rear end of the inner guide shaft 73 is press-fitted into a shaft hole 72B formed in the front tilting plate 72, and the inner guide shaft 73 protrudes forward from the front tilting plate 72. The diameter of the inner guide shaft 73 is set slightly smaller than the groove width of the inner guide groove 71C. The front end of the inner guide shaft 73 is movably inserted into the inner guide groove 71C and is positioned within the lower end of the inner guide groove 71C. As a result, the inner guide shaft 73 is guided by the inner guide groove 71C when the circular saw body 20 rotates between the upright position and the tilted position. Furthermore, when the circular saw body 20 is tilted, the inner guide shaft 73 is positioned within the upper end of the inner guide groove 71C.

[0052] An outer guide shaft 74 is provided on the radially outer side of the front tilting plate 72 at a position corresponding to the outer guide groove 71D of the front guide 71. The outer guide shaft 74 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction and has the same shape as the inner guide shaft 73. The rear end of the outer guide shaft 74 is press-fitted into a shaft hole 72C formed in the front tilting plate 72, and the outer guide shaft 74 protrudes forward from the front tilting plate 72. A cylindrical bearing member 75 is provided on the front end of the outer guide shaft 74 and is configured as a ball bearing. The diameter of the bearing member 75 is set slightly smaller than the groove width of the outer guide groove 71D. The bearing member 75 is movably inserted into the outer guide groove 71D and is disposed within the lower end of the outer guide groove 71D. As a result, the outer guide shaft 74 (bearing member 75) is guided by the outer guide groove 71D when the circular saw body 20 rotates between the upright position and the tilted position. When the circular saw body 20 is in the tilted position, the outer guide shaft 74 (bearing member 75) is disposed within the upper end of the outer guide groove 71D. The outer guide shaft 74 and the inner guide shaft 73 are guide shafts according to the present invention and are an example of a guided portion.

[0053] A fixed shaft 76 is provided on the front tilt plate 72 between the inner guide shaft 73 and the outer guide shaft 74. The fixed shaft 76 is provided between the inner guide shaft 73 and the outer guide shaft 74 in the radial direction (direction perpendicular to the front-rear direction) centered on the axis line AL. The fixed shaft 76 is formed in a substantially cylindrical shape with the front-rear direction as its axial direction. The rear end of the fixed shaft 76 is non-rotatably connected to the front tilt plate 72 and protrudes forward from the front tilt plate 72. The diameter of the fixed shaft 76 is set smaller than the width dimension of the fixing hole 71E. The fixed shaft 76 passes through the lower end of the fixing hole 71E, and the front end of the fixed shaft 76 protrudes forward from the front guide 71. A fixed lever 77 (see FIGS. 1 and 2 ) serving as a substantially elongated fixing member is provided on the front end of the fixed shaft 76. One end of the fixed lever 77 is threadedly engaged with a threaded portion formed on the outer periphery of the front end of the fixed shaft 76. As a result, by fastening the fixing lever 77 to the front guide 71 , the front tilting plate 72 is fixed to the front guide 71 .

[0054] Additionally, a plate connector 72D is integrally formed at the lower end of the left section of the front tilt plate 72. This connector connects the front tilt plate 72 to a rear tilt plate 82 of a rear tilt mechanism 80 (described later). In other words, the front tilt plate 72 and the rear tilt plate 82 are formed from a single, inseparable member. The plate connector 72D is formed in a generally elongated plate shape with a thickness extending up and down and a length extending back and forth, and extends rearward from the front tilt plate 72.

[0055] (Regarding the Front Link 78) The front link 78 is made of sintered metal (iron in this embodiment) and is impregnated with lubricating oil. That is, the front link 78 is made of a material with higher mechanical strength than the front guide 71. The front link 78 is formed in a plate shape with its thickness in the front-to-rear direction and extending along the rotation direction of the circular saw body 20, and is movably housed in the accommodating recess 71B of the front guide 71. Specifically, the radially outer surface of the front link 78 is disposed adjacent to the radially inner side of the upper inner circumferential surface of the accommodating recess 71B, and the radially inner surface of the front link 78 is disposed adjacent to the radially outer side of the lower inner circumferential surface of the accommodating recess 71B. Here, the upper inner circumferential surface and the lower inner circumferential surface of the accommodating recess 71B correspond to partial arcs of a perfect circle centered on the axis AL (the intersection of the circular saw blade 14 and the horizontal plane GB). As a result, the front link 78 is connected to the front guide 71 so as to be rotatable about the axis AL, and when the front tilting mechanism 70 is activated, the front link 78 rotates about the axis AL while being guided by the accommodation recess 71B. The front link 78 is made of sintered metal for the purposes of durability and lubrication, but may be made of another material such as resin if these problems are minor.

[0056] A pair of link holes 78A serving as restriction holes are formed through the front link 78. The link holes 78A are holes that penetrate in the front-rear direction. The link holes 78A are elongated holes (extending in a direction intersecting the extension direction of the output shaft 44) with their longitudinal direction extending in the up-down direction (a direction intersecting the extension direction of the output shaft 44). The width of the link holes 78A is set slightly larger than the diameters of the inner guide shaft 73 and the outer guide shaft 74. The link holes 78A are disposed at positions corresponding to the inner guide shaft 73 and the outer guide shaft 74, respectively, and the front-rear intermediate portions of the inner guide shaft 73 and the outer guide shaft 74 are inserted into the lower portions of the link holes 78A. As a result, the front link 78 is connected to the front tilt plate 72 with the inner guide shaft 73 and the outer guide shaft 74 engaged with the link holes 78A in the left-right direction. Furthermore, as described above, when the circular saw body 20 rotates between the upright position and the tilted position, the circular saw body 20 is configured to move closer to or farther away from the base 12 along the side of the circular saw blade 14, so that the inner guide shaft 73 and the outer guide shaft 74 move relatively within the link hole 78A in the longitudinal direction of the link hole 78A.

[0057] An insertion hole 78B is formed through the front link 78 between the pair of link holes 78A, and the insertion hole 78B is formed as an elongated hole with its longitudinal direction extending in the up-down direction. The width of the insertion hole 78B is set to be larger than the diameter of the fixed shaft 76. The insertion hole 78B is located at a position corresponding to the fixed shaft 76, and the intermediate portion of the fixed shaft 76 in the front-to-rear direction is inserted through the lower portion of the insertion hole 78B. When the circular saw body 20 rotates between the upright position and the tilted position, the fixed shaft 76 moves relative to the insertion hole 78B in the longitudinal direction of the insertion hole 78B.

[0058] 5, 8, and 11, the rear tilting mechanism 80 is disposed rearward of the saw cover 24 and is configured by inverting the front tilting mechanism 70 in the front-to-rear direction. That is, the rear tilting mechanism 80 includes a rear guide 81 as a guide member, a rear tilting plate 82 as a movable member, and a rear link 88 as a restricting member. The rear tilting plate 82 is disposed in front of the rear guide 81, and the rear link 88 is disposed between the rear guide 81 and the rear tilting plate 82.

[0059] (Regarding the rear guide 81) The rear guide 81 is made of metal (aluminum in this embodiment) and is configured substantially similar to the front guide 71 inverted in the front-to-rear direction. That is, the rear guide 81 is formed in a plate shape with its thickness direction in the front-to-rear direction, and a guide fixing portion 81A provided at the lower end of the rear guide 81 is fastened and fixed to the base 12 by a fixing screw SC2. A storage recess 81B is formed in the front surface of the rear guide 81, and the storage recess 81B extends in the rotation direction of the circular saw body 20 in a front view seen from the front side.

[0060] The front surface of the rear guide 81 is formed with an inner guide groove 81C and an outer guide groove 81D, which serve as guide grooves that are open to the front. Like the inner guide groove 71C and the outer guide groove 71D, the inner guide groove 81C and the outer guide groove 81D are curved in a generally arc-like shape centered on the axis AL when the rear guide 81 is in the upright position. The radius of curvature of each of the inner guide groove 81C and the outer guide groove 81D increases from their respective lower ends (ends on one longitudinal side, which are also the left end) to their respective upper ends (ends on the other longitudinal side, which are also the right end). An end face 81C1 of the lower end of the inner guide groove 81C is inclined toward one longitudinal side of the inner guide groove 81C toward the front (the opening side of the inner guide groove 81C), while an end face 81C2 of the upper end of the inner guide groove 81C is inclined toward the other longitudinal side of the inner guide groove 81C toward the front. Furthermore, an end face 81D1 of the lower end of the outer guide groove 81D is inclined toward one side in the longitudinal direction of the outer guide groove 81D as it approaches the front side (the opening side of the outer guide groove 81D). Note that in the rear guide 81, the groove widths of the inner guide groove 81C and the outer guide groove 81D are set to the same dimension.

[0061] A fixing hole 81E is formed through the front surface of the rear guide 81. The fixing hole 81E is disposed between the inner guide groove 81C and the outer guide groove 81D, and like the fixing hole 71E, is curved in a generally arc shape centered on the axis AL so as to be parallel to the inner guide groove 81C and the outer guide groove 81D in a front view, with the radius of curvature of the fixing hole 81E increasing from the lower end to the upper end. The characteristics and effects of the radius of curvature of the guide groove in the rear guide 81 are similar to those of the front guide 71, and therefore will not be described in detail.

[0062] (Regarding the rear tilt plate 82) Like the rear guide 81, the rear tilt plate 82 is made of metal (aluminum in this embodiment). The rear tilt plate 82 is formed in a generally trapezoidal plate shape with its thickness extending in the front-to-rear direction. A plate fixing portion 82A that is raised one step forward is formed at the lower end of the front surface of the rear tilt plate 82, and the plate fixing portion 82A is fastened and fixed to the rear connecting mechanism 30B of the cutting depth adjustment mechanism 30. In this way, the rear tilt plate 82 is connected to the rear end of the circular saw body 20.

[0063] Similar to the front tilt plate 72, the rear tilt plate 82 is provided with an inner guide shaft 83 serving as a guide shaft, an outer guide shaft 84 serving as a guide shaft, and a fixed shaft 86, which protrude rearward from the rear tilt plate 82. The inner guide shaft 83 and the outer guide shaft 84 have the same shapes as the inner guide shaft 73 and the outer guide shaft 74 of the front tilt plate 72. The inner guide shaft 83 is press-fitted into a shaft hole 82B formed in the rear tilt plate 82, and the rear end of the inner guide shaft 83 is movably inserted into the inner guide groove 81C and is disposed within the lower end of the inner guide groove 81C. The outer guide shaft 84 is press-fitted into a shaft hole 82C formed in the rear tilt plate 82, and the rear end of the outer guide shaft 84 is movably inserted into the outer guide groove 81D and is disposed within the lower end of the outer guide groove 81D. Furthermore, when the circular saw body 20 is in the tilted position, the inner guide shaft 83 is disposed at the upper end of the inner guide groove 81C, and the outer guide shaft 84 is disposed at the upper end of the outer guide groove 81D. The outer guide shaft 84 and the inner guide shaft 83 are guide shafts in the present invention and are an example of a guided portion.

[0064] The fixed shaft 86 is inserted through the lower end of the fixing hole 81E, and the rear end of the fixed shaft 86 protrudes rearward from the rear guide 81. A fixing knob 87 (see FIGS. 1 and 2) serving as a fixing member is provided at the rear end of the fixed shaft 86, and the fixing knob 87 is screwed into a threaded portion formed on the outer periphery of the rear end of the fixed shaft 86. As a result, by tightening the fixing knob 87 to the rear guide 81, the rear tilt plate 82 is fixed to the rear guide 81.

[0065] The plate fixing portion 82A of the rear tilt plate 82 protrudes to the left from the rear tilt plate 82, and the rear end of the plate connecting portion 72D of the front tilt plate 72 is connected to the plate fixing portion 82A. In this way, the rear tilt plate 82 is connected to the front tilt plate 72.

[0066] (Regarding the rear link 88) Like the front link 78, the rear link 88 is made of sintered metal (iron in this embodiment), and the rear link 88 is impregnated with lubricating oil. The rear link 88 is formed in a plate shape with its thickness in the front-to-rear direction and extending along the rotation direction of the circular saw body 20, and is movably housed in the accommodation recess 81B of the rear guide 81. That is, like the front link 78, the rear link 88 is connected to the rear guide 81 so as to be rotatable about the axis AL, and when the rear tilting mechanism 80 is operated, the rear link 88 rotates about the axis AL while being guided by the accommodation recess 81B.

[0067] Similar to the front link 78, the rear link 88 is formed with a pair of link holes 88A and insertion holes 88B as restriction holes. The link holes 88A and insertion holes 88B are elongated holes with their longitudinal directions extending in the up-down direction. The link holes 88A are located at positions corresponding to the inner guide shaft 83 and outer guide shaft 84 of the rear tilt plate 82, respectively, and the longitudinally intermediate portions of the inner guide shaft 83 and outer guide shaft 84 are inserted through the lower portions of the link holes 88A. As a result, the rear link 88 is connected to the rear tilt plate 82 with the inner guide shaft 83 and outer guide shaft 84 engaged with the link holes 88A in the left-right direction. The insertion hole 88B is located at a position corresponding to the fixed shaft 86, and the longitudinally intermediate portion of the fixed shaft 86 is inserted through the lower portion of the insertion hole 88B.

[0068] 9 to 11, the axis AL is located below the base 12, and the position of the axis AL in the left-right direction substantially coincides with the position of the circular saw blade 14 (washer member 16) in the upright position (see FIG. 9). As described above, the radii of curvature of the inner guide groove 71C and the outer guide groove 71D (inner guide groove 81C and outer guide groove 81D) of the front guide 71 (rear guide 81) are set to increase from the bottom to the top. Furthermore, the inner guide shaft 73 (inner guide shaft 83) is disposed at the bottom end of the inner guide groove 71C (inner guide groove 81C), and the outer guide shaft 74 (outer guide shaft 84) is disposed at the bottom end of the outer guide groove 71D (outer guide groove 81D). When the tilting mechanism 60 tilts the circular saw body 20 from the upright position to the tilted position, the inner guide shaft 73 (inner guide shaft 83) moves to the upper end along the inner guide groove 71C (inner guide groove 81C), and the outer guide shaft 74 (outer guide shaft 84) moves to the upper end along the outer guide groove 71D (outer guide groove 81D). Therefore, when the circular saw body 20 tilts from the upright position to the tilted position, the circular saw body 20 is set to move upward relative to the base 12. Note that the radii of curvature of the inner guide groove 71C and the outer guide groove 71D of the front guide 71 and the inner guide groove 81C and the outer guide groove 81D of the rear guide 81 are set so that the amount of upward movement of the circular saw body 20 relative to the base 12 by the front tilting mechanism 70 is the same as the amount of upward movement of the circular saw body 20 relative to the base 12 by the rear tilting mechanism 80.

[0069] More specifically, in the upright position, as described above, the lower end of the washer member 16 for connecting the circular saw blade 14 to the output shaft 44 is located within the insertion portion 12A of the base 12 and above the axis AL (see FIGS. 3 and 9). The radii of curvature of the inner guide groove 71C and the outer guide groove 71D of the front guide 71 and the inner guide groove 81C and the outer guide groove 81D of the rear guide 81 are set so that the lower end of the washer member 16 is displaced to the right within the insertion portion 12A of the base 12 when the tilting mechanism 60 rotates the circular saw body 20 from the upright position to the tilted position (see FIGS. 4 and 10). In other words, when the tilting mechanism 60 rotates the circular saw body 20 from an upright position to a tilted position, the circular saw body 20 moves upward relative to the base 12 so that the vertical position of the lower end of the washer member 16 does not change downward (so that the washer member 16 does not protrude downward from the base 12).

[0070] (Operation and Effect) Next, the operation and effect of this embodiment will be described.

[0071] In the circular saw 10 configured as described above, the circular saw blade 14 is arranged with the thickness direction of the workpiece extending in the left-right direction when the circular saw body 20 is in the upright position. 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.

[0072] To incline the cutting surface of the workpiece, the tilting mechanism 60 tilts the circular saw body 20 from the upright position toward the tilted position. For example, to incline the cutting surface of the workpiece at a 45-degree angle, the tilting mechanism 60 tilts the circular saw body 20 to the tilted position (45-degree tilted position). Specifically, in the front tilting mechanism 70, the fixed lever 77 is rotated to release the fixed lever 77 from the front guide 71, and in the rear tilting mechanism 80, the fixed knob 87 is rotated to release the fixed knob 87 from the rear guide 81. This allows the circular saw body 20 to tilt (move) toward the tilted position.

[0073] Then, the operator tilts the circular saw body 20 from the upright position toward the tilted position. This causes the tilting mechanism 60 to rotate the circular saw body 20 so as to tilt to the right. Specifically, the inner guide shaft 73 of the front tilting plate 72 moves from the lower end to the upper end along the inner guide groove 71C of the front guide 71, and the outer guide shaft 74 of the front tilting plate 72 moves from the lower end to the upper end along the outer guide groove 71D of the front guide 71. Furthermore, the inner guide shaft 83 of the rear tilting plate 82 moves from the lower end to the upper end along the inner guide groove 81C of the rear guide 81, and the outer guide shaft 84 of the rear tilting plate 82 moves from the lower end to the upper end along the outer guide groove 81D of the rear guide 81. In the front tilting mechanism 70, the inner guide shaft 73 reaches the upper end of the inner guide groove 71C, and the outer guide shaft 74 reaches the upper end of the outer guide groove 71D. In the rear tilting mechanism 80, the inner guide shaft 83 reaches the upper end of the inner guide groove 81C, and the outer guide shaft 84 reaches the upper end of the outer guide groove 81D, thereby positioning the circular saw body 20 in the tilted position. When the circular saw body 20 is tilted from the upright position to the tilted position, the fixed shaft 76 is positioned at the upper end of the fixing hole 71E of the front guide 71, and the fixed shaft 86 is positioned at the upper end of the fixing hole 81E of the rear guide 81. In this state, the fixing lever 77 is rotated to tighten the fixing lever 77 to the front guide 71, and the fixing knob 87 is rotated to tighten the fixing knob 87 to the rear guide 81, thereby fixing the circular saw body 20 to the base 12 (connected so as not to move relative to the base 12).

[0074] In a tilting mechanism in which the rotation during tilting is positioned below (below left) the washer member 16, the washer member 16 is displaced diagonally downward to the right when the circular saw body 20 rotates from the upright position to the tilted position. For this reason, in the past, it was necessary to avoid interference between the washer member 16 and the workpiece by positioning the circular saw body 2 sufficiently above the workpiece so that the washer member would not protrude below the base during tilting, which could result in a decrease in workability.

[0075] Here, in the tilting mechanism 60 of the circular saw 10, the front tilting mechanism 70 of the tilting mechanism 60 includes a front tilting plate 72 connected to the circular saw body 20 and a front guide 71 that guides the rotation of the front tilting plate 72. Furthermore, the rear tilting mechanism 80 of the tilting mechanism 60 includes a rear tilting plate 82 connected to the circular saw body 20 and a rear guide 81 that guides the rotation of the rear tilting plate 82. The front tilting plate 72 and the rear tilting plate 82 are configured so as not to move relative to the circular saw body 20 when the circular saw body 20 tilts. When the circular saw body 20 tilts (rotates) from the upright position to the tilted position, the front guide 71 and the rear guide 81 move the circular saw body 20 away from the base 12 along the side of the circular saw blade 14. As a result, the cutting depth becomes shallower (the amount by which the circular saw blade 14 protrudes downward from the base underside 12C decreases). This prevents the washer member 16, which connects the circular saw blade 14 to the output shaft 44, from being displaced downward even when the circular saw body 20 is tilted from the upright position. Specifically, the lower end of the washer member 16 is located inside the insertion portion 12A of the base 12 when the circular saw body 20 is in the upright position, tilted position, and a predetermined position between the upright position and the tilted position. As a result, the washer member 16 is prevented from protruding downward from the base 12 while preventing a decrease in the cutting depth of the circular saw blade 14. Therefore, a decrease in workability with the circular saw 10 is prevented.

[0076] The front guide 71 has an inner guide groove 71C and an outer guide groove 71D that guide the rotation of the front tilting plate 72, and the rear guide 81 has an inner guide groove 81C and an outer guide groove 81D that guide the rotation of the rear tilting plate 82. The inner guide groove 71C (inner guide groove 81C) and the outer guide groove 71D (outer guide groove 81D) are formed in an arc shape centered on the axis AL when viewed from the front-to-rear direction and are inclined upward toward the right. The inner guide shaft 73 (inner guide shaft 83) is inserted into the lower end of the inner guide groove 71C (inner guide groove 81C), and the outer guide shaft 74 (outer guide shaft 84) is inserted into the lower end of the outer guide groove 71D (outer guide groove 81D). The radii of curvature of the inner guide groove 71C (inner guide groove 81C) and the outer guide groove 71D (outer guide groove 81D) are set to increase from the lower end to the upper end. This allows the circular saw body 20 to be moved upward relative to the base 12 while rotating from the upright position to the tilted position with a simple configuration. In other words, this configuration makes it possible to control the amount of movement of the lower end of the washer member 16 that moves with tilting, thereby preventing a portion of the washer member 16 from protruding downward from the base 12. This means that the length (amount) by which the circular saw blade 14 protrudes from the base undersurface 12C, i.e., the change in cutting depth, can be controlled. In particular, in this embodiment, the amount of vertical movement of the lower end of the washer member 16 caused by tilting the circular saw body 20 is configured to be equal to or less than the vertical distance between the lower end of the washer member 16 and the base undersurface 12C when the circular saw body 20 is in the non-tilted position. Specifically, the amount of vertical movement of the lower end of the washer member 16 is set to 0.5 mm, and the distance S1 is set to 1.0 mm. This effectively prevents contact between the washer member 16 and the workpiece. When applying the present invention, if the purpose is to ensure the cutting depth in the upright position, the lower end position of the washer member 16 in the tilted state may be configured to be the same as or higher than the lower end position of the washer member 16 in the upright state (non-tilted state). By making the lower end positions of the washer member 16 the same in the tilted state and the upright state, unnecessary reduction in cutting depth can be prevented.In this embodiment, the axis AL is positioned a predetermined distance below the base undersurface 12C because cutting is performed using a guide rail. However, the present invention can also be applied to circular saws that do not require a guide rail. For example, the axis AL may be positioned so that it overlaps the base undersurface 12C. In this case, when cutting without a guide rail (i.e., the base 12 slides directly over the workpiece), the cutting position on the workpiece surface can be configured to remain unchanged even when the saw is tilted. In other words, the horizontal plane GB and the base undersurface 12C may be configured to be flush with each other. The present invention is particularly effective when the axis AL is positioned below the washer 16 (the holding member for the circular saw blade 14).

[0077] Although the radius of curvature of the guide groove is configured to increase from the lower end to the upper end, the present invention is not limited to this. For example, during the reverse tilting described above, the washer member moves upward, reducing the cutting depth. Therefore, the change in the radius of curvature may be reversed to ensure the desired cutting depth during reverse tilting. Furthermore, adjusting the radius of curvature of the guide groove can control the movement of the main body during tilting in order to optimally position auxiliary functions (such as a lighting device or a blower mechanism). Furthermore, while the aforementioned embodiment may result in the inclined guide portions (front guide 71, rear guide 81) becoming larger in exchange for ensuring the desired cutting depth, reversing the change in the radius of curvature can also reduce the size of the inclined guide portions (front guide 71, rear guide 81). In this case, although the lower end position of the washer member 16 continuously moves downward with tilting, in addition to the aforementioned compactness effect, the amount of lateral movement of the washer member 16 with tilting can also be reduced. In other words, the benefits of the present invention are not limited to ensuring the desired cutting depth. In addition, in this embodiment, the guide groove is provided on the base 12 side and the guide shaft is provided on the circular saw body 20 side. However, this relationship may be reversed, with the guide groove on the circular saw body 20 side and the guide shaft on the base 12 side. Furthermore, the guide groove has a groove shape with one end closed in the front-to-rear direction, but it may also be a through hole. While the washer member 16 serving as a washer has been described as a member for holding the circular saw blade 14, the present invention is not limited to washers and may be any member for holding the circular saw blade 14. In other words, the present invention may be configured to adjust the amount of vertical movement of the holding member for holding the circular saw blade 14 during tilting. Furthermore, in this specification, the washer 16 (holding member) has been described as an example of a member that may be positioned below the base underside 12C during tilting. However, other members that move during tilting may also be included. For example, depending on the shape, parts of the fixing bolt 52 and the saw cover 24 may be positioned below the washer 16 when tilted, and when tilted in reverse, parts of the motor housing 26 and battery 32 located on the left side of the circular saw body 20 move downward, so care must be taken to ensure that these do not protrude below the base underside 12C or hit the base 12 when tilted.

[0078] As described above, the front guide 71 has the inner guide groove 71C and the outer guide groove 71D, and the rear guide 81 has the inner guide groove 81C and the outer guide groove 81D. That is, in the front tilting mechanism 70 and the rear tilting mechanism 80, the rotation of the circular saw body 20 is guided by the guide grooves in two locations. Therefore, the front tilting plate 72 and the rear tilting plate 82 can be well guided when they rotate.

[0079] In the front tilting mechanism 70, the cylindrical inner guide shaft 73 is movably inserted into the inner guide groove 71C, which guides the movement of the inner guide shaft 73. In the rear tilting mechanism 80, the cylindrical inner guide shaft 83 (outer guide shaft 84) is movably inserted into the inner guide groove 81C (outer guide groove 81D), which guides the movement of the inner guide shaft 83 (outer guide shaft 84). As a result, when the tilting mechanism 60 is operated, these guide shafts come into line contact with the inner surfaces of their corresponding guide grooves and are guided by these guide grooves. This reduces sliding resistance during operation of the tilting mechanism 60, and allows the tilting mechanism 60 to operate smoothly.

[0080] Furthermore, in the front tilting mechanism 70, a bearing member 75 configured as a ball bearing (rolling bearing) is provided at the tip of the outer guide shaft 74, and the bearing member 75 is movably inserted into the outer guide groove 71D. This further reduces the sliding resistance during operation of the front tilting mechanism 70 and allows the front tilting mechanism 70 to operate more smoothly. The invention in which a bearing member is provided on the guide shaft can also be applied to a configuration in which the radius of curvature of the arc-shaped guide portion is constant.

[0081] In the front tilting mechanism 70, a fixed shaft 76 extends forward from the front tilting plate 72 and passes through a fixing hole 71E of the front guide 71, with the front end of the fixed shaft 76 protruding forward from the front guide 71. A fixing lever 77 is threadedly engaged with the front end of the fixed shaft 76. By tightening the fixing lever 77 to the front guide 71, the circular saw body 20 can be fixed to the base 12 (connected so as not to move relative to the base 12). Similarly, in the rear tilting mechanism 80, a fixed shaft 86 extends rearward from the rear tilting plate 82 and passes through a fixing hole 81E of the rear guide 81, with the rear end of the fixed shaft 86 protruding rearward from the rear guide 81. A fixing knob 87 is threadedly engaged with the rear end of the fixed shaft 86. By tightening the fixing knob 87 to the rear guide 81, the circular saw body 20 can be fixed to the base 12 (connected so as not to move relative to the base 12).

[0082] In the front tilting mechanism 70, the front tilting plate 72 is disposed behind the front guide 71, and the inner guide groove 71C and the outer guide groove 71D of the front guide 71 are formed as grooves that open toward the rear. In the rear tilting mechanism 80, the rear tilting plate 82 is disposed in front of the rear guide 81, and the inner guide groove 81C and the outer guide groove 81D of the rear guide 81 are formed as grooves that open toward the front. This prevents chips generated during cutting from entering the inner guide groove 71C, outer guide groove 71D, inner guide groove 81C, and outer guide groove 81D. This allows the tilting mechanism 60 to operate smoothly.

[0083] The front tilting mechanism 70 also has a front link 78, which is connected to the front guide 71 so as to be rotatable about an axis AL. A pair of elongated link holes 78A, each extending vertically, is formed in the front link 78. The inner guide shaft 73 and the outer guide shaft 74 are inserted through the link holes 78A, and the inner guide shaft 73 and the outer guide shaft 74 are engaged with the link holes 78A in the left-right direction. Similarly, the rear tilting mechanism 80 also has a rear link 88, which is connected to the rear guide 81 so as to be rotatable about the axis AL. A pair of elongated link holes 88A, each extending vertically, is formed in the rear link 88. The inner guide shaft 83 and the outer guide shaft 84 are inserted through the link holes 88A, and the inner guide shaft 83 and the outer guide shaft 84 are engaged with the link holes 88A in the left-right direction. That is, the tilting of the guide shafts (73, 74, 83, 84) in this embodiment is guided by two elements: a guide portion (guide groove) provided on the base 12, and a restricting member (front link 78, rear link 88) that rotates relative to the base 12 when the circular saw body 20 tilts. As a result, the guide shafts are able to move in the direction of extension of the arc of the guide portion while the restricting member restricts the circular saw body 20 from moving relative to the restricting member (front link 78, rear link 88) in the direction of extension of the output shaft 44. In other words, the circular saw body 20 is supported by the restricting member so that it can tilt relative to the base 12 by moving relative to the restricting member (front link 78, rear link 88) that rotates relative to the base 12 when the circular saw body 20 tilts in a direction perpendicular to the direction of extension of the output shaft 44. This prevents the guide shafts (73, 74, 83, 84) from moving in the direction of extension of the output shaft 44 within the arc-shaped guide portion during tilting, and prevents excessive contact between the guide shafts and the guide portion. Therefore, when the tilting mechanism 60 is activated, the front tilting plate 72 (and rear tilting plate 82) can be rotated smoothly, allowing the circular saw body 20 to tilt even more smoothly.

[0084] That is, if the front link 78 were omitted from the front tilting mechanism 70, movement of the inner guide shaft 73 and the outer guide shaft 74 in the inner guide groove 71C and the outer guide groove 71D (particularly in the extension direction of the output shaft 44) would not be restricted. The same applies to the rear tilting mechanism 80. Therefore, when the tilting mechanism 60 is in operation, for example, if the circular saw body 20 moves relative to the base 12 in the extension direction of the output shaft 44, or if there is a left-right positional deviation between the front tilting plate 72 and the rear tilting plate 82, a part of the guide shaft (73, 74, 83, 84) may move within the guide portion in a direction intersecting the arc (guide direction), causing excessive contact between the inner surface of the guide portion and the guide shaft, which may prevent the circular saw body 20 from tilting smoothly.

[0085] In contrast, the front tilting mechanism 70 (rear tilting mechanism 80) is provided with a front link 78 (rear link 88) that engages with the front tilting plate 72 (rear tilting plate 82) in the left-right direction (the extension direction of the output shaft 44). Therefore, the front link 78 (rear link 88) can restrict movement of the inner guide shaft 73 and the outer guide shaft 74 (the inner guide shaft 83 and the outer guide shaft 84) in the longitudinal direction (mainly the left-right direction) of the inner guide groove 71C and the outer guide groove 71D (the inner guide groove 81C and the outer guide groove 81D). Moreover, the front link 78 (rear link 88) is connected to the front guide 71 (rear guide 81) to be rotatable about the axis AL. Therefore, the inner guide shaft 73 and the outer guide shaft 74 (the inner guide shaft 83 and the outer guide shaft 84) move along the longitudinal direction of the inner guide groove 71C and the outer guide groove 71D (the inner guide groove 81C and the outer guide groove 81D) in accordance with the amount of left-right displacement of the front guide 71 (the rear guide 81) rotating about the axis AL. As a result, relative movement of the circular saw body 20 with respect to the base 12 in the direction of the output shaft 44 and left-right positional deviation between the front tilting plate 72 and the rear tilting plate 82 can be suppressed when the tilting mechanism 60 is activated. Therefore, when the tilting mechanism 60 is activated, the front tilting plate 72 and the rear tilting plate 82 can be rotated smoothly and the tilting operation of the circular saw body 20 can be made even smoother. The invention that regulates the movement of the guide shaft using a regulating member (front link 78, rear link 88) can be applied even to a configuration in which the radius of curvature of the arc-shaped guide portion is constant, and is particularly effective in circular saws that have a tilting mechanism using a virtual tilting axis.

[0086] Furthermore, the front link 78 (rear link 88) is made of sintered metal such as iron, and the front guide 71 (rear guide 81) is made of aluminum. That is, the mechanical strength of the front link 78 (rear link 88) is configured to be higher than the mechanical strength of the front guide 71 (rear guide 81). This improves the wear resistance of the front link 78 (rear link 88) and also improves the durability of the tilting mechanism 60.

[0087] The front link 78 (rear link 88) is impregnated with lubricating oil. This further improves the wear resistance of the front link 78 (rear link 88) and the durability of the tilting mechanism 60. In particular, the lubricating oil smooths the sliding between the link hole 78A (link hole 88A) and the inner guide shaft 73 and the outer guide shaft 74 (inner guide shaft 83 and outer guide shaft 84), thereby suppressing deterioration due to wear and preventing poor operation due to excessive frictional resistance. The front link 78 (rear link 88) is interposed between the circular saw body 20 (front tilt plate 72) and the base 12 (front guide 11), thereby reducing resistance (sliding resistance) when they move relative to each other. The above describes an invention that can improve cutting performance by changing the radius of curvature of the guide groove. However, the sliding resistance reduction mechanism using the front link 78 (rear link 88) can be applied independently of the invention of changing the radius of curvature of the guide groove.

[0088] 10...Circular saw (working machine), 12...Base, 12A...Through-through portion, 14...Circular saw blade, 16...Washer member, 20...Circular saw body (main body), 42...Motor, 44...Output shaft, 60...Tilting mechanism, 71...Front guide (guide member), 71C...Inner guide groove (guide groove), 71D...Outer guide groove (guide groove), 71E...Fixing hole, 72...Front tilting plate (movable member), 73...Inner guide shaft (guide shaft), 74...Outer guide shaft (guide shaft), 75...Bearing member, 76 ...Fixed shaft, 77...Fixed lever (fixed member), 78...Front link (regulating member), 81...Rear guide (guide member), 81C...Inner guide groove (guide groove), 81D...Outer guide groove (guide groove), 81E...Fixed hole, 82...Rear tilt plate (movable member), 83...Inner guide shaft (guide shaft), 84...Outer guide shaft (guide shaft), 86...Fixed shaft, 87...Fixed knob (fixed member), 88...Rear link (regulating member), 88A...Link hole (regulating hole), AL...Axis

Claims

1. A main body portion having a motor and an output shaft whose axial direction is the left - right direction and which rotates by driving of the motor; A circular saw blade that is integrally rotatably connected to the output shaft and extends in the front - rear direction; A washer member for holding the circular saw blade on the output shaft; A base disposed below the main body portion and having an insertion portion through which the circular saw blade is inserted; A tilting mechanism configured to be able to tilt the main body portion with respect to the base from a non - tilting state in which the output shaft extends in the left - right direction to a tilting state by tilting a predetermined angle to one side in the left - right direction; Comprising: The tilting mechanism includes a guide member provided on one of the main body portion and the base and having a guide portion, and a guided portion provided on the other of the main body portion and the base and operating inside the guide portion and guided in its movement by the guide portion; In both the non - tilting state and the tilting state, it is configured such that a virtual axis extending in the front - rear direction overlaps with the circular saw blade at a position below the washer member; In a virtual state in which the main body portion in the non - tilting state is rotated by the predetermined angle about the virtual axis, at least a part of the washer member is positioned below the lower surface of the base, and when shifting from the non - tilting state to the tilting state, the washer member is operated above the lower surface of the base by the guiding of the movement of the guided portion with respect to the guide portion of the guide portion. A working machine characterized by this.

2. The working machine according to claim 1, wherein in at least one of the non - tilting state and the tilting state, at least a part of the washer member is located inside the insertion portion.

3. The working machine according to claim 1 or claim 2, wherein the guide portion is formed in an arc shape, and the radius of curvature of the guide portion is set to be larger at least in part.

4. The working machine according to claim 3, wherein a pair of the guide portions are formed on the guide member, and one of the guide portions is located radially outside the other guide portion.

5. The working machine according to claim 4, wherein the guided portion includes a pair of guide shafts whose axial direction is the front - rear direction, and the guide shafts are respectively movably inserted into the pair of guide portions.

6. The working machine according to claim 5, wherein the guide shafts are formed in a cylindrical shape.

7. The guided part is provided with a bearing member, and the bearing member is movably inserted into the guide part. The working machine according to claim 1.

8. A pair of the guide part and the guided part are respectively provided. The pair of guided parts are arranged so that they are separated from each other in a direction orthogonal to the front-rear direction. The bearing member is provided on the outer side in at least the direction orthogonal to the front-rear direction among the pair of guided parts. The working machine according to claim 7.

9. A pair of the guide part and the guided part are respectively provided. The guide part is formed in an arc shape. A fixing hole having an arc shape is formed in the guide member separately from the guide part. The tilting mechanism has a fixing shaft inserted through the fixing hole and a fixing member provided at the tip of the fixing shaft and operated by an operator. The operator can allow or restrict the tilting of the main body part with respect to the base by operating the fixing member. The fixing hole is configured to be located between the pair of guide parts in a direction orthogonal to the front-rear direction. The working machine according to claim 1.

10. The tilting mechanism has a restricting member configured to be rotatable about the front-rear direction. The restricting member is configured to guide the movement of the main body part so as to allow relative movement of the main body part in a predetermined direction with respect to the restricting member. The working machine according to claim 1.

11. A restricting hole extending in a direction intersecting the extending direction of the output shaft is formed in the restricting member, and a part of the main body part passes through the restricting hole, and the main body part and the restricting member are engaged with each other in the extending direction of the output shaft, whereby relative movement of the main body part in a direction intersecting the predetermined direction with respect to the restricting member is restricted. The working machine according to claim 10.

12. The restricting member is made of a material having higher mechanical strength than the guide member, or is configured to be impregnated with lubricating oil, or is formed by sintering. The working machine according to claim 10.

13. A main body part having a motor and an output shaft that rotates by driving of the motor. A circular saw blade integrally and rotatably connected to the output shaft. A washer member for holding the circular saw blade on the output shaft. A base disposed below the main body part and having an insertion part through which the circular saw blade is inserted. A tilting mechanism capable of tilting the main body portion from a non-tilting state to a tilting state in which it is tilted 45 degrees with respect to the base, comprising, a working machine configured such that the lower end position of the washer member in the tilting state is the same as or higher than the lower end position of the washer member in the non-tilting state.

14. A main body portion having a motor and an output shaft that rotates by driving the motor, a circular saw blade integrally and rotatably connected to the output shaft, a base disposed below the main body portion and having an insertion portion through which the circular saw blade is inserted, a tilting mechanism capable of tilting the main body portion from a non-tilting state to a tilting state in which it is tilted 45 degrees with respect to the base, comprising, the circular saw blade is connected to the output shaft via a washer member, a working machine configured such that the intersection of a horizontal plane parallel to the lower surface of the base and the circular saw blade, which is located below the washer member, is substantially at the same position when the main body portion is in the non-tilting state and when the main body portion is in the tilting state, and the difference between the lower end position of the washer member in the non-tilting state and the lower end position of the washer member in the tilting state in the vertical direction is equal to or less than the vertical distance between the lower end position of the washer member in the non-tilting state and the lower surface of the base.

15. A main body portion having a motor and an output shaft that rotates by driving the motor, a circular saw blade integrally and rotatably connected to the output shaft, a base disposed below the main body portion and having an insertion portion through which the circular saw blade is inserted, a tilting mechanism capable of tilting the main body portion from a non-tilting state to a tilting state with respect to the base, comprising, the circular saw blade is connected to the output shaft via a washer member, a working machine configured such that the intersection of a horizontal plane parallel to the lower surface of the base and the circular saw blade, which is located below the washer member, is substantially at the same position when the main body portion is in the non-tilting state and when the main body portion is in the tilting state, and when the main body portion is tilted from the non-tilting state to the tilting state, the lower end of the washer member is configured to move continuously upward or downward.