Benchtop cutting machine

Abstract

To provide a cutting machine on a bench with good perceptibility to a notch position for a cutter, allowing the cutter to be made closer to a slide bar.SOLUTION: A cutting machine 1 on a bench comprises: a long slide bar 51 extending in a longitudinal direction; a slide base 52 slidable along the slide bar 51; and a cutting machine body 10 swingable in a vertical direction around a vertical swing support shaft 10a as a center. The cutting machine body 10 comprises: an output shaft 37 protruded in a shaft direction perpendicular to the slide bar 51, on which a cutter 11 is attached; an electric motor 23 disposed between the cutter 11 and the slide bar 51 in a state the cutter 11 is vertically placed and positioned at a position higher than that of the slide bar 51; and a driving-force transmission part 30 transmitting driving-force of a motor shaft 23a of the electric motor 23 to the output shaft 37. The driving-force transmission part 30 is placed between the cutter 11 and the slide bar 51 and placed at a position higher than that of the slide bar 51 when the cutting machine body 10 is positioned at a top dead point.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a bench cutter used for cutting materials such as wood. [Background technology]

[0002] This type of bench cutter has, for example, a long slide bar and a slide base attached to the slide bar and movable along the slide bar. A cutting machine body is attached to the slide base. The cutting machine body has an electric motor and a substantially circular cutting tool that rotates using the electric motor as a power source. The side of the cutting tool is parallel to the slide bar. The cutting machine body can swing up and down relative to the slide base. The cutting tool is rotated to move the cutting machine body toward the workpiece placed below. This causes the cutting tool to cut into the workpiece. Furthermore, by moving the cutting machine body along the extension direction of the slide bar, the cutting tool moves horizontally relative to the workpiece. This allows the workpiece to be cut along the extension direction of the slide bar.

[0003] The slide bar is positioned to the right of the right side or left of the left side of the cutting tool as seen from a user positioned at the front of the bench cutter so as not to interfere with the movement of the cutting tool. The invention described in Patent Document 1 has a slide bar that extends along the side of the cutting tool from the right side to the right of the right side of the cutting tool. The motor housing that houses the electric motor is positioned above the cutting tool and protrudes to the left, opposite the slide bar, from the cutting tool. Therefore, when a user visually checks the cutting position of the cutting tool in the workpiece, the protruding part of the motor housing to the left may obstruct visibility. As a result, the user may have to lower their head to view the cutting position.

[0004] The invention described in Patent Document 2 has a slide bar that extends leftward from the left side of the cutting tool along the side of the cutting tool. The motor housing that houses the electric motor is located to the right of the cutting tool and is positioned in an inclined position with the cutting tool in a vertical position. The inclination of the motor housing is a direction that slopes upward toward the right when viewed from the front. When a user visually checks the cutting position of the cutting tool in the workpiece, the slide bar located to the left of the cutting tool may obstruct visibility. For this reason, the user may have to lower their head to check the cutting position.

[0005] The electric motors used in bench cutters include DC brushless motors powered by a DC power source, such as a rechargeable battery, and AC brushed motors powered by an AC power source. AC brushed motors, in particular, have a larger motor diameter than DC brushless motors. Therefore, when placing the electric motor near the cutting tool, it is often placed between the cutting tool and the slide bar, or on the opposite side of the slide bar from the cutting tool when viewed from the front. In the former case, the horizontal distance between the cutting tool and the slide bar is large, while in the latter case, the horizontal distance between the electric motor and the slide bar is large. This increases the moment of the cutting machine body with the slide bar as the fulcrum, making it difficult to maintain high mechanical rigidity of the cutting machine body. This can result in reduced cutting accuracy. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-279933 [Patent Document 2] Japanese Patent Application Publication No. 2018-89867 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, there is room for improvement in the arrangement of the electric motor of a bench cutter to improve the visibility of the cutting position of the cutting tool, the mechanical rigidity of the cutting machine body, the cutting accuracy of the cutting tool, etc. Therefore, there is a need for a bench cutter that provides good visibility of the cutting position of the cutting tool and allows the cutting tool to be moved closer to the slide bar. [Means for solving the problem]

[0008] According to one feature of the present disclosure, a bench cutter has a long slide bar extending in the front-to-rear direction. The bench cutter has a slide base attached to the slide bar and sliding in the front-to-rear direction along the slide bar. The bench cutter has a cutting machine body attached to the slide base so as to be swingable in the vertical direction around a vertical swing support shaft. The cutting machine body has an output shaft extending in an axial direction perpendicular to the slide bar and to which a cutting tool is attached. The cutting machine body is a power source for driving the output shaft, and has an electric motor located between the cutting tool and the slide bar when viewed from the front and above the slide bar when the cutting tool is in a vertical position. The cutting machine body has a power transmission unit that transmits the driving force of the motor shaft of the electric motor to the output shaft. The power transmission unit is located between the cutting tool and the slide bar when viewed from the front and is above the slide bar when the cutting machine body is at top dead center.

[0009] Therefore, by providing a power transmission unit between the electric motor and the output shaft, the electric motor can be positioned above the slide bar regardless of whether the cutting machine body is at top dead center or bottom dead center. This allows the cutting tool to be positioned closer to the slide bar. As a result, when the cutting machine body is at top dead center, the electric motor and power transmission unit are positioned above the slide bar. This allows for good visibility of the cutting position of the cutting tool when the cutting machine body is at top dead center. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a bench cutter according to a first embodiment, seen from the left. FIG. [Figure 2]FIG. 2 is a perspective view of the bench cutter as seen from the right. [Figure 3] FIG. 2 is a perspective view of the bench cutter when viewed from the right side with the cutter body positioned at the rear end. [Figure 4] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the top dead center. [Figure 5] FIG. 2 is a left side view of the bench cutter with the cutter body positioned at the bottom dead center and at the rear end. [Figure 6] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the bottom dead center. [Figure 7] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the bottom dead center and at the rear end. [Figure 8] FIG. 2 is a plan view of the bench cutter with the cutter body positioned at the bottom dead center. [Figure 9] FIG. 2 is a plan view of the bench cutter in a state where the cutter body is positioned at the bottom dead center and at the rear end. [Figure 10] FIG. 2 is a front view of the bench cutter with the cutter body positioned at the bottom dead center. [Figure 11] FIG. 2 is a front view of the bench cutter with the cutter body positioned at the bottom dead center and tilted to the left. [Figure 12] FIG. 2 is a front view of the bench cutter with the cutter body positioned at the bottom dead center and tilted to the right. [Figure 13] FIG. 2 is a rear view of the bench cutter with the cutter body positioned at the top dead center. [Figure 14] 14 is a cross-sectional view taken along the line XIV-XIV in FIG. 4. [Figure 15] 5 is a cross-sectional view taken along the line XV-XV in FIG. 4. [Figure 16] FIG. 10 is a left side view showing a state in which the cutting machine body of the bench cutter according to the second embodiment is located at the top dead center. [Figure 17] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the top dead center. [Figure 18] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the top dead center and at the rear end. [Figure 19]FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the bottom dead center. [Figure 20] FIG. 2 is a right side view of the bench cutter with the cutter body positioned at the bottom dead center and at the rear end. [Figure 21] FIG. 18 is a cross-sectional view taken along line XXI-XXI in FIG. 17. DETAILED DESCRIPTION OF THE INVENTION

[0011] According to another feature of the present disclosure, the power transmission unit includes a shaft that transmits driving force from the motor shaft to the output shaft. The shaft intersects with the slide bar when viewed from the axial direction when the cutting machine body is positioned at bottom dead center. Therefore, when the cutting machine body is positioned at bottom dead center, the shaft is positioned between the cutting tool and the slide bar when viewed from the front. The electric motor is positioned above the shaft and above the slide bar. This allows the distance between the cutting tool and the slide bar to be shortened in the axial direction of the output shaft. This allows the mechanical rigidity of the cutting machine body to be maintained high and prevents a decrease in the cutting accuracy of the cutting tool.

[0012] According to another feature of the present disclosure, the diameter of the shaft is 1 / 40 to 1 / 20 of the diameter of the cutting tool, which allows the shaft to be provided with the strength required to support the electric motor, and also allows the distance between the cutting tool and the slide bar to be shortened in the axial direction of the output shaft.

[0013] According to another feature of the present disclosure, the motor includes a cylindrical shaft housing that accommodates the shaft. The shaft housing has an expanded diameter portion that expands in the radial direction of the shaft around the driven-side end of the shaft that is connected to the output shaft. This allows the shaft housing to be axially screwed to the output-shaft side housing. This improves assembly ease and increases the support rigidity of the shaft housing.

[0014] According to another feature of the present disclosure, the distance in the axial direction of the output shaft from the cutting tool to the slide bar is ¾ or less of the diameter of the cutting tool. Therefore, the distance in the axial direction of the output shaft from the cutting tool to the slide bar can be minimized, thereby increasing the mechanical rigidity of the cutting machine body supported by the slide bar. Therefore, when the cutting tool cuts into the workpiece, vibration of the cutting tool in the axial direction of the output shaft can be suppressed.

[0015] According to another feature of the present disclosure, when the cutting machine body is positioned at the bottom dead center, the entire electric motor is positioned between the output shaft and the vertical swing support shaft in the front-to-rear direction. Therefore, the center of gravity of the cutting machine body positioned at the bottom dead center can be moved closer to the vertical swing support shaft. This reduces the fluctuating load when the cutting machine body swings up and down. The cutting machine body is biased from the bottom dead center toward the top dead center by a spring attached around the vertical swing support shaft. By reducing the fluctuating load of the cutting machine body, the spring load of the spring can be reduced. Furthermore, the mechanical rigidity of the cutting machine body centered around the vertical swing support shaft can be increased.

[0016] According to another feature of the present disclosure, when the cutting machine body is at the top dead center, the entire electric motor is located behind the vertical swing support shaft, so the load of the electric motor can be used to swing the cutting machine body upward and return it to the top dead center, thereby reducing the spring load of the spring that biases the cutting machine body toward the top dead center.

[0017] According to another feature of the present disclosure, when the cutting tool is in a vertical position, the motor shaft is parallel to the side of the cutting tool or inclined at an angle of 10° or less relative to the side when viewed from the radial direction of the motor shaft. Therefore, the motor shaft can be positioned along the side of the cutting tool. This allows the electric motor to be positioned close to the cutting tool in the axial direction of the output shaft. This allows the cutting machine body to be made compact in the axial direction of the output shaft.

[0018] According to another feature of the present disclosure, the center of the electric motor is arranged at a position 30 to 50% of the distance from the cutting tool to the slide bar in the direction perpendicular to the surface of the cutting tool starting from the cutting tool. Therefore, the center of the electric motor is arranged closer to the cutting tool than the slide bar. Thus, the center of gravity of the cutting machine body can be brought closer to the cutting tool in the axial direction of the output shaft. Thereby, when the cutting machine body is moved downward to cut the cutting tool into the workpiece to be cut, the torsional moment caused by the reaction force received by the cutting tool from the workpiece to be cut and the weight of the cutting machine body can be reduced.

[0019] According to another feature of the present disclosure, the electric motor is a brushed motor driven by supplying power from an AC power source. Therefore, even when a brushed motor with a relatively large motor diameter is provided, it is possible to suppress the visibility being hindered by the brushed motor when checking the cutting position of the cutting tool. Further, even when a brushed motor is provided, the distance between the cutting tool and the slide bar in the axial direction of the output shaft can be shortened.

[0020] According to another feature of the present disclosure, the slide bar has a plurality of bars arranged in parallel. The plurality of bars includes a first bar located at the uppermost position and a second bar located at the lowermost position. When the diameter of the first bar is a [mm], the diameter of the second bar is b [mm], the center-to-center distance between the first bar and the second bar is c [mm], and the diameter of the cutting tool is d [mm], the relationship of (a / 2 + b / 2 + c) × 2 < d < (a / 2 + b / 2 + c) × 3.5 is satisfied. Therefore, the plurality of bars can be compactly accommodated within a range of a length shorter than half of the diameter of the cutting tool in the vertical direction. Moreover, the vertical distance including all the plurality of bars is larger than 2 / 7 times the diameter of the cutting tool. Therefore, the plurality of bars can be provided to have sufficient strength to support the cutting machine body. Thus, it is possible to achieve both the compactness and the support strength of the slide structure of the cutting machine body.

[0021] According to another feature of the present disclosure, the motor shaft is oriented at an inclination angle that tilts upward toward the rear when the cutting machine body is at the bottom dead center. This minimizes the amount of downward protrusion of the electric motor when the cutting machine body is at the bottom dead center, allowing the bench cutter to be made compact in the vertical direction.

[0022] According to another feature of the present disclosure, the inclination angle of the motor shaft is 30° to 60° with respect to the horizontal when the cutting machine body is positioned at the bottom dead center. This prevents the motor housing that houses the electric motor from coming into contact with the workpiece. This allows the workpiece to be cut effectively using a compact bench cutter.

[0023] According to another feature of the present disclosure, the motor shaft is parallel to the horizontal line or has an inclination angle of 10° or less with respect to the horizontal line when the cutting machine body is at the top dead center. This reduces the amount of upward or downward protrusion of the electric motor. This prevents obstruction to visibility when checking the cutting position of the cutting tool.

[0024] According to another feature of the present disclosure, the bench cutter has an operating handle used to move the cutting machine body relative to the slide bar. The center of the operating handle is located on an imaginary plane including the cutting tool when viewed from the front with the cutting tool in a vertical position, or between the slide bar and the cutting tool. Therefore, the centers of the slide bar and the operating handle can be brought closer to the axial direction of the output shaft. Therefore, when a user grips the operating handle and drives the cutting tool into a workpiece, the torsional moment of the cutting machine body relative to the slide bar can be reduced. Furthermore, the centers of the cutting tool and the operating handle can be brought closer to the axial direction of the output shaft. Therefore, when a user grips the operating handle and drives the cutting tool into a workpiece, the torsional moment due to the reaction force the cutting tool receives from the workpiece and the operating force applied to operate the operating handle can be reduced.

[0025] According to another feature of the present disclosure, the center of the operating handle is located at a position 30 to 70% of the distance from the cutting tool to the slide bar in the axial direction, starting from the cutting tool. Therefore, the center of the operating handle is located at a position that is not too far from both the cutting tool and the slide bar. This reduces the torsional moment of the cutting machine body acting between the cutting tool and the operating handle. Furthermore, it is possible to suppress deflection of the slide bar due to the operating force applied to the operating handle.

[0026] According to another feature of the present disclosure, the bench cutter has a bottom dead center stopper that prevents the cutter body from moving below the bottom dead center. The center of the bottom dead center stopper is located between the slide bar and the cutter when viewed from the front when the cutter is vertical. This allows for a shorter axial distance between the center of the bottom dead center stopper and the slide bar. The bottom dead center stopper receives a reaction force when the cutter body descends to the bottom dead center. This shorter distance reduces the torsional moment of the cutter body relative to the slide bar caused by the reaction force.

[0027] According to another feature of the present disclosure, the center of the bottom dead center stopper is positioned 30 to 70% of the axial distance from the cutting tool to the slide bar, starting from the cutting tool. Therefore, the center of the bottom dead center stopper is positioned not too far from both the cutting tool and the slide bar. This reduces the reaction force received by the bottom dead center stopper and the torsional moment acting on the cutting machine body between the slide bar and the slide bar, and also suppresses vibration of the cutting tool due to the torsional moment.

[0028] A first embodiment of the present disclosure will be described with reference to FIGS. 1 to 15. In this embodiment, a bench cutter 1, commonly known as a sliding circular saw, will be illustrated. As shown in FIGS. 1 and 2, the bench cutter 1 includes a base 2 placed on a table or floor, a turntable 4 on which a workpiece to be cut is placed, and a cutting machine body 10. The turntable 4 is supported above the base 2 so as to be rotatable horizontally about a rotation support shaft 2a extending vertically. The cutting machine body 10 is provided above the turntable 4. A generally disk-shaped cutting tool (circular saw blade) 11, known as a tipped saw blade, is rotatably supported on the cutting machine body 10. A user performs cutting work while positioned in front of the bench cutter 1. In the following description, the front side is defined as the front side when viewed from the user. The up, down, left, and right directions are defined relative to the user.

[0029] As shown in Figures 1 and 2, the turntable 4 is generally circular in plan view, with the table top surface 4a horizontal. A rotation support shaft 2a is located in the center of the generally circular disk shape of the turntable 4. The base 2 has upward protrusions 3 on both left and right ends, and the turntable 4 is supported in the space between the left and right upward protrusions 3 so that it can rotate horizontally. Note that this embodiment uses a turntable 4 that is larger than usual, and the left and right ends of the base 2 do not have a mounting surface on which the workpiece is placed. The turntable 4 has a table extension 5 that extends forward along the side of the cutting tool 11. A notched slot 5a is provided in the center of the top surface of the table extension 5, extending along the side of the cutting tool 11. For convenience, the cutting edge plate provided above the slot 5a is not shown in the drawing.

[0030] As shown in Figures 1 and 2, a wall-shaped positioning fence 6 that extends left and right and upward is provided above the turntable 4 and upward protrusion 3. The positioning fence 6 is supported by the left and right upward protrusions 3. The positioning surface 6b, which is the front surface of the positioning fence 6, is located on a vertical plane that passes through the rotation support shaft 2a, which is the center of rotation of the turntable 4. The workpiece to be cut placed on the turntable 4 is positioned in the front-to-rear direction by contacting it with the positioning surface 6b. An upward extension fence 6a that can extend the positioning surface 6b upward can be removably attached above the positioning fence 6.

[0031] As shown in FIGS. 1 and 2 , an arc-shaped miter scale plate 7 is provided in a region covering approximately half the circumference of the front portion of the base 2. The miter scale plate 7 extends horizontally below the table top surface 4a. The miter scale plate 7 indicates the rotation angle of the turntable 4 in cooperation with indicators 8 provided on both the left and right sides of the turntable 4. The rotation angle of the turntable 4 is the angle between the cutting tool 11 and the positioning surface 6b of the positioning fence 6. By rotating the turntable 4 left or right, the cutting tool 11 can be positioned at an angle relative to the positioning surface 6b of the positioning fence 6. Cutting the workpiece with the cutting tool 11 in this position is called a miter cut. The miter scale plate 7 is provided with multiple groove-like positioning recesses 7b extending radially. The positioning recesses 7b are provided at predetermined angular intervals around the circumference of the miter scale plate 7. The tips of positioning pins 64a (described later) can enter the positioning recesses 7b. The miter scale plate 7 is fixed to the base 2 by a plurality of fixing screws 7a. The fixing screws 7a are inserted into elongated holes that penetrate the miter scale plate 7 in the vertical direction. The angle between the positioning fence 6 and the cutting tool 11 can be finely adjusted by loosening the fixing screws 7a and moving the miter scale plate 7 left and right. For example, if the positioning pin 64a is inserted into the positioning recess 7b at the right angle, the right angle between the cutting tool 11 and the positioning fence 6 can be precisely adjusted. This adjustment is mainly performed during the product production process.

[0032] As shown in Figures 1 and 2, a substantially cylindrical arm support part 4b with its axial direction extending in the front-to-rear direction is provided at the rear of the turntable 4. A main body support arm 50 extending substantially upward is provided behind the arm support part 4b. The main body support arm 50 is supported on the arm support part 4b so as to be tiltable in the left-to-right direction around a left-to-right tilting support shaft 50a extending in the front-to-rear direction. The main body support arm 50 tilts upward and substantially to the right when the cutting tool 11 is vertical. An upper part 50b of the main body support arm 50 is configured to be retracted from the movable range of the cutting machine main body 10 when a slide base 52 (described later) is moved to the rear end.

[0033] As shown in FIGS. 1 and 2 , a long slide bar 51 extending horizontally and parallel to the side of the cutting tool 11 is attached to the upper portion 50b of the main body support arm. The slide bar 51 has an upper first bar 51a and a lower second bar 51b arranged side by side in the vertical direction. A slide base 52 is attached to the first bar 51a and the second bar 51b so as to be slidable in the front-to-rear direction. The cutting machine main body 10 is connected to the left of the slide base 52. Therefore, when the cutting tool 11 is vertical, the cutting machine main body 10 is positioned to the left of the first bar 51a and the second bar 51b. By sliding the slide base 52 in the front-to-rear direction, it is possible to cut, for example, a wide workpiece placed on the turntable 4. A knob 9 is provided on the upper right side of the slide base 52. By turning the knob 9 in the tightening direction, the slide base 52, which slides relative to the slide bar 51, can be fixed at any position.

[0034] As shown in FIGS. 4 and 10, the first bar 51a is formed into a cylindrical shape with a diameter 51e of, for example, 30 mm. The second bar 51b is formed into a cylindrical shape with a diameter 51f of, for example, 25 mm, which is smaller than the diameter 51e. The center 51c of the first bar 51a and the center 51d of the second bar 51b extend parallel to each other in the front-to-rear direction. The center 51c of the first bar 51a and the center 51d of the second bar 51b are located at approximately the same position in the left-to-right direction when the cutting tool 11 is vertical. Note that an imaginary plane passing through the center of the base metal of the cutting tool 11 in the thickness direction and extending parallel to the side of the cutting tool 11 is defined as a first imaginary plane S1. An imaginary plane passing through the center 51c of the first bar 51a and the center 51d of the second bar 51b is defined as a second imaginary plane S2. The first imaginary plane S1 and the second imaginary plane S2 are approximately parallel to each other.

[0035] As shown in FIGS. 4 and 10, the cutting tool 11 rotates around the output shaft 37. The distance between the first imaginary plane S1 and the second imaginary plane S2 in the left-right direction (the extension direction of the output shaft 37) is ¾ or less of the diameter 11a of the cutting tool 11, and preferably ½ or less of the diameter 11a of the cutting tool 11. The distance between the first imaginary plane S1 and the second imaginary plane S2 is, for example, 132 mm, with the diameter 11a being 305 mm. The center 51c of the first bar 51a and the center 51d of the second bar 51b are spaced apart in the vertical direction by a center-to-center distance 51g of, for example, 65 mm. The diameters 51e, 51f and the center-to-center distance 51g are set to satisfy the relationship of the following (Equation 1), where the diameter 51e is a [mm], the diameter 51f is b [mm], the center-to-center distance 51g is c [mm], and the diameter 11a of the cutting tool 11 is d [mm]. For example, in the case of a bench cutter 1 equipped with a cutting tool 11 having a diameter 11a of 305 mm, diameters 51e, 51f and center distance 51g are set so that 305 / 3.5=87 [mm] < (a / 2 + b / 2 + c) < 305 / 2 = 153 [mm]. (Formula 1)(a / 2+b / 2+c)×2 <d<(a / 2+b / 2+c)×3.5

[0036] As shown in Figures 11 and 12, the main body support arm 50 can be tilted up to 45° left and right around the left and right tilting support shaft 50a. Furthermore, by switching the tilt positioning mechanism (located at the rear of the main body support arm 50 but omitted from the drawings for convenience), it can be tilted up to 48°. Therefore, the cutting tool 11 can also be tilted up to 48° left and right around the left and right tilting support shaft 50a. By tilting the cutting tool 11 left and right, a so-called bevel cut can be performed on a workpiece placed on the turntable 4. When tilted leftward, the cutting machine main body 10 does not have any protruding parts to the left of the cutting tool 11 or around the lower portion of the cutting tool 11 (although the movable cover 13 is shown positioned around the lower portion of the cutting tool 11 in the drawings, it actually moves upward). Therefore, the cutting machine main body 10 other than the cutting tool 11 does not come into contact with the workpiece, allowing for optimal bevel cutting. When the cutting machine body 10 is tilted to the right, there is no protruding part to the right of the cutting tool 11 or around the lower part of the cutting tool 11. Therefore, the cutting machine body 10 other than the cutting tool 11 does not come into contact with the material to be cut, allowing for suitable bevel cutting.

[0037] As shown in Figures 4 and 5, the cutting machine body 10 can swing up and down relative to the slide base 52 around a vertical swing support shaft 10a extending in the left-right direction. The vertical swing support shaft 10a is located behind the cutting tool 11. By swinging the cutting machine body 10 downward, the cutting tool 11 can cut into the workpiece placed on the turntable 4. The vertical swing angle of the cutting machine body 10 is 0° when the bottom dead center is 0°, and 40° when the top dead center is 0°. In other words, the cutting machine body 10 can swing up and down within an angle range of 40°. A torsion spring is provided around the vertical swing support shaft 10a to urge the cutting machine body upward toward the top dead center.

[0038] As shown in FIGS. 4 and 5 , the cutting machine body 10 has a fixed cover 12 and a movable cover 13 that cover the cutting tool 11. The fixed cover 12 covers the upper half of the circumference of the cutting tool 11 from both the left and right sides and from the radially outward direction. The movable cover 13 can cover the lower half of the circumference of the cutting tool 11. The movable cover 13 rotates in conjunction with the up and down swing of the cutting machine body 10 to open and close the lower half of the circumference of the cutting tool 11. When the cutting machine body 10 is swung upward, the movable cover 13 rotates toward the closed position (clockwise in FIG. 5 ). Therefore, when the cutting machine body 10 is positioned at the top dead center, the lower half of the circumference of the cutting tool 11 is covered. When the cutting machine body 10 is swung downward, the movable cover 13 rotates toward the open position (counterclockwise in FIG. 5 ). Therefore, the lower half of the circumference of the cutting tool 11 is exposed, allowing the cutting tool 11 to cut into a workpiece placed on the turntable 4.

[0039] 14 and 15, the cutting tool 11 is attached integrally to an output shaft 37 that extends in the left-right direction and is rotatably supported on the cutting machine body 10. The cutting tool 11 is attached to the output shaft 37 by tightening the fixing screw 14 with the center of rotation sandwiched between the outer flange 15 and the inner flange 16.

[0040] As shown in Figure 13, a bottom dead center stopper 17 is provided on the right side of the cutting machine body 10. The bottom dead center stopper 17 has a bolt that is screwed to the cutting machine body 10 and protrudes downward. The protruding length of the bottom dead center stopper 17 can be changed, for example, by inserting a hexagonal wrench into the hexagonal hole in the head of the bolt and rotating it. This allows fine adjustment of the bottom dead center position of the cutting machine body 10. A bottom dead center stopper abutment portion 52a (see Figure 4) is provided on the front surface of the slide base 52, which abuts against the tip of the bottom dead center stopper 17 when the cutting machine body 10 is lowered to the bottom dead center. The bottom dead center stopper abutment portion 52a is a flat surface provided on the upper surface of a protrusion that protrudes forward on the front surface of the slide base 52.

[0041] As shown in FIG. 13 , the bottom dead center stopper 17 is located between the side surface of the cutting tool 11 and the slide bar 51 in the left-right direction. When the cutting tool 11 is vertical and the cutting machine body 10 is at the top dead center, the center 17a of the bottom dead center stopper 17 is located to the right of a first imaginary plane S1 that passes through the center of the cutting tool 11 and to the left of a second imaginary plane S2 that passes through the center 51c of the first bar 51a. The center 17a is preferably located at 30 to 70% of the distance from the first imaginary plane S1 to the second imaginary plane S2, e.g., 58% of the distance, starting from the first imaginary plane S1 and extending to the right in the direction perpendicular to the surface of the cutting tool 11. The distance from the first imaginary plane S1 to the center 17a is, for example, 76.5 mm. When the distance from the first imaginary plane S1 to the second imaginary plane S2 is 132 mm, 76.5 mm / 132 mm = 58%.

[0042] 5, 8, and 13, a top dead center stopper 18 that protrudes leftward is provided on the left side of the fixed cover 12. A flat top dead center stopper abutment portion 52b that can abut against the top dead center stopper 18 is provided on the upper surface of the left side of the slide base 52. The abutment of the top dead center stopper 18 and the top dead center stopper abutment portion 52b stops the upward movement of the cutting machine body 10 at the top dead center.

[0043] As shown in FIG. 1, a bottom dead center lock pin 19 extending leftward is provided on the left side surface of the front of the slide base 52. A through hole 19a extending left and right is provided in the fixed cover 12 in front of the top dead center stopper 18. When the cutting machine body 10 moves to the bottom dead center, the bottom dead center lock pin 19 moves rightward and can enter the through hole 19a. The cutting machine body 10 can be locked at the bottom dead center by pushing the left end of the bottom dead center lock pin 19 rightward and entering the through hole 19a.

[0044] As shown in Figures 8 to 10, the cutting machine body 10 has a motor housing 20 between the cutting tool 11 and the slide bar 51 in the left-right direction. The motor housing 20 accommodates an electric motor 23. A motor shaft 23a is provided in the center of the electric motor 23. The motor shaft 23a extends in the front-rear direction along a motor axis J parallel to the side surface of the cutting tool 11. The motor housing 20 is formed by connecting a rear housing 21 at the rear and a front housing 22 in the front-rear direction. The rear housing 21 has a generally cylindrical shape extending in the front-rear direction. The front housing 22 has a generally conical shape whose diameter decreases from rear to front. A power cord 25 that can be connected to an external AC power source is provided above the motor housing 20. The power cord 25 extends rearward along the longitudinal direction of the motor housing 20 (for convenience, only a cord guard is shown in the drawings, and other parts of the power cord 25 are omitted).

[0045] As shown in Fig. 14, the front end 21a of the rear housing 21 has a larger inner diameter than the rear region of the rear housing 21. The rear end 22a of the front housing 22 has a larger inner diameter than the front region of the front housing 22. The front end 21a of the rear housing 21 and the rear end 22a of the front housing 22 are connected by a plurality of fixing screws 21b (see Fig. 9) extending along the direction of the motor axis J.

[0046] 4 and 14, the electric motor 23 is a motor known as an AC brush motor that is driven by power supplied from an AC power source. The motor shaft 23a is supported by a first bearing 23e and a second bearing 23f so as to be rotatable about the motor axis J. The first bearing 23e has an inner ring press-fitted onto the rear end of the motor shaft 23a, and an outer ring press-fitted into a hole provided at the inside rear end of the rear housing 21. A cylindrical shaft support portion 22b extending in the front-rear direction is provided inside the front housing 22. The second bearing 23f has an inner ring press-fitted onto the front portion of the motor shaft 23a, and an outer ring press-fitted into a hole 22c provided at the rear end of the shaft support portion 22b.

[0047] As shown in FIG. 14 , a stator 23b of the electric motor 23 is non-rotatably supported on the inner circumferential surface of the rear housing 21. A rotor 23c of the electric motor 23 is disposed on the inner circumferential side of the stator 23b. The rotor 23c is attached along the outer periphery of the motor shaft 23a and is rotatable together with the motor shaft 23a. A commutator 23d is attached to the rear of the rotor 23c. An air intake port that can take in outside air is provided on the rear surface of the rear housing 21. A fan 24 is attached between the second bearing 23f and the rotor 23c in front of the motor shaft 23a and is rotatable integrally with the motor shaft 23a. The fan 24 is housed on the inner circumferential side of the rear end 22a of the front housing 22. When the electric motor 23 is driven and the fan 24 rotates, cooling air is introduced into the motor housing 20 from the air intake port. The cooling air flows toward the front fan 24 and is discharged from an exhaust port provided in the front housing 22 radially outward of the fan 24. The electric motor 23 is cooled by the cooling air.

[0048] 8 and 10, the cutting machine body 10 has a power transmission unit 30 that transmits the driving force of the motor shaft 23a to the output shaft 37 between the cutting tool 11 and the slide bar 51 in the left-right direction. The power transmission unit 30 is housed in a shaft housing 31, a gear housing 33, and a gear accommodating unit 12a provided on the right side of the fixed cover 12. The shaft housing 31 is connected to an opening at the front end of the front housing 22. The gear housing 33 connects the opening at the front end of the shaft housing 31 to an opening at the right end of the gear accommodating unit 12a.

[0049] As shown in FIG. 14, the shaft housing 31 is generally cylindrical and extends along the side surface of the cutting tool 11. The motor housing connecting portion 31a at the rear end of the shaft housing 31 and the gear housing connecting portion 31b at the front end have larger diameters than the central region of the shaft housing 31. The gear housing connecting portion 31b has a larger inner diameter than the motor housing connecting portion 31a. The motor housing connecting portion 31a is connected to the front end of the front housing 22 by a spigot joint that covers the outer periphery of the shaft support portion 22b. The motor housing connecting portion 31a and the front end of the front housing 22 are connected by a plurality of fixing screws 22e that extend along the motor axis J. The gear housing connecting portion 31b is connected to the shaft housing connecting portion 33a at the rear end of the gear housing 33 by a plurality of fixing screws 33e (see FIG. 4) that extend along the motor axis J.

[0050] As shown in FIG. 14, the shaft housing 31 accommodates a linearly extending shaft 32. The shaft 32 is arranged coaxially with the motor shaft 23a. The shaft 32 is cylindrical with a diameter 32c that is 1 / 40 to 1 / 20 of the diameter 11a of the cutting tool 11. The diameter 32c is, for example, 10 mm, assuming that the diameter 11a of the cutting tool 11 is 305 mm. The front end of the motor shaft 23a and the rear drive end 32a of the shaft 32 are inserted into a cylindrical connecting sleeve 32d and connected to each other so as to transmit rotational power. The shaft 32 is a long-axis drive shaft, and the length per diameter (length / diameter) is 10 to 20. For example, the length 32j is 127 mm for a diameter 32c of 10 mm. In this case, 127 mm / 10 mm [= length 32j / diameter 32c] is 12.7. The material used is alloy steel for mechanical structures such as chrome molybdenum steel (SCM material) or nickel chrome molybdenum steel (SNCM material). For example, chrome molybdenum steel is used.

[0051] As shown in FIG. 14 , the shaft 32 is supported by a third bearing 32g and a fourth bearing 32h so as to be rotatable about the motor axis J. The third bearing 32g has an inner ring press-fitted into the rear portion of the shaft 32, and an outer ring press-fitted into a hole 22d provided at the front end of the shaft support portion 22b. The fourth bearing 32h has an inner ring press-fitted into the front portion of the shaft 32, and an outer ring press-fitted into a hole 33c provided in the shaft-housing connecting portion 33a at the rear end of the gear housing 33. The fourth bearing 32h is prevented from coming off from the hole 33c by a washer 32i. The second bearing 23f and the third bearing 32g are both positioned in the holes 22c and 22d provided in the front housing 22, thereby enabling the motor shaft 23a, the shaft 32, and the first intermediate shaft 35 to be positioned with high precision. A drive-side bevel gear 32e is integrally attached to the front driven-side end 32b of the shaft 32. A nut 32f is attached to the front of the drive bevel gear 32e to prevent it from coming off. The drive bevel gear 32e is inserted into the gear housing 33.

[0052] 14 and 15, the gear housing 33 has a shaft housing connecting portion 33a that opens rearward at its rear end and a fixed cover connecting portion 33b that opens leftward at its left side, which are connected to each other internally. The gear accommodating portion 12a of the fixed cover 12 has a gear housing connecting portion 12d that opens rightward at its right end and an opening through which the output shaft 37 protrudes toward the left cutting tool 11, which are connected to each other internally. The fixed cover connecting portion 33b is connected by a spigot joint that covers the outer periphery of the gear housing connecting portion 12d. The fixed cover connecting portion 33b and the gear housing connecting portion 12d are connected by a plurality of fixing screws 33f that extend in a direction substantially perpendicular to the side surface of the cutting tool 11.

[0053] 14 and 15 , a first intermediate shaft 35, a second intermediate shaft 36, and an output shaft 37 are supported in the gear housing 33 and the gear accommodating portion 12a so as to be rotatable about their respective axes. The first intermediate shaft 35, the second intermediate shaft 36, and the output shaft 37 extend in the left-right direction, perpendicular to the side surface of the cutting tool 11. A bearing box 34 is connected to the left side surface of the gear housing 33 by a plurality of fixing screws 34d that extend in a direction substantially perpendicular to the side surface of the cutting tool 11. The bearing box 34 holds bearings that support the first intermediate shaft 35, the second intermediate shaft 36, and the output shaft 37, respectively.

[0054] As shown in Fig. 14, the first intermediate shaft 35 is rotatably supported by a fifth bearing 35c and a sixth bearing 35d. The fifth bearing 35c has an inner ring press-fitted into the right end of the first intermediate shaft 35, and an outer ring press-fitted into a hole 33d provided on the right side inside the gear housing 33. The sixth bearing 35d has an inner ring press-fitted into the left end of the first intermediate shaft 35, and an outer ring press-fitted into a hole 34a provided in the bearing box 34. Both the fourth bearing 32h and the fifth bearing 35c are positioned in the holes 33c and 33d provided in the gear housing 33, thereby enabling the shaft 32 and the first intermediate shaft 35 to be positioned with high precision. Furthermore, the meshing between the drive-side bevel gear 32e and the driven-side bevel gear 35a can be achieved with high precision.

[0055] As shown in FIG. 14, the driven bevel gear 35a is inserted into the right side of the first intermediate shaft 35 with a mid-fit so as to be movable in the axial direction. The driven bevel gear 35a and the first intermediate shaft 35 are prevented from rotating relative to each other by engagement between a key and a key groove. A steel washer 35e, a rubber ring 35f, and a steel washer 35g are attached to the right side of the driven bevel gear 35a on the first intermediate shaft 35. A wheel stopper 35h is attached to the rubber ring 35f, which is sandwiched between the washers 35e and 35g, so that it is crushed in the axial direction. The rubber ring 35f buffers shocks and vibrations between the first intermediate shaft 35 and the driven bevel gear 35a. The driven bevel gear 35a meshes with the drive bevel gear 32e. The rotational power of the shaft 32 is reduced in speed and its rotation direction is converted to a substantially vertical direction before being transmitted to the first intermediate shaft 35 via the meshing of the drive bevel gear 32e and the driven bevel gear 35a. A reduction gear 35b is formed as an integral part with the first intermediate shaft 35 between the driven bevel gear 35a and the sixth bearing 35d in the left-right direction.

[0056] As shown in FIG. 15 , the second intermediate shaft 36 is rotatably supported by a seventh bearing 36b and an eighth bearing 36c. The seventh bearing 36b has an inner ring press-fitted into the right end of the second intermediate shaft 36, and an outer ring press-fitted into a hole 12b provided on the right side of the interior of the gear accommodating portion 12a. The eighth bearing 36c has an inner ring press-fitted into the left end of the second intermediate shaft 36, and an outer ring press-fitted into a hole 34b provided in the bearing box 34. A reduction gear 36a is formed as an integral part with the second intermediate shaft 36 between the seventh bearing 36b and the eighth bearing 36c in the left-right direction. The reduction gear 36a meshes with the reduction gear 35b. The rotational power of the first intermediate shaft 35 is reduced in speed and transmitted to the second intermediate shaft 36 via the meshing of the reduction gear 35b and the reduction gear 36a.

[0057] As shown in FIG. 15 , the output shaft 37 is rotatably supported by a ninth bearing 37b and a tenth bearing 37c. The inner ring of the ninth bearing 37b is press-fitted onto the right end of the output shaft 37, and the outer ring is press-fitted into a hole 12c provided on the right side inside the gear accommodating portion 12a. The inner ring of the tenth bearing 37c is press-fitted into the center of the output shaft 37, and the outer ring is press-fitted into a hole 34c provided in the bearing box 34. A reduction gear 37a is formed as an integral part with the output shaft 37 between the ninth bearing 37b and the tenth bearing 37c in the left-right direction. The reduction gear 37a meshes with the reduction gear 36a. The rotational power of the second intermediate shaft 36 is reduced in speed and transmitted to the output shaft 37 via the meshing of the reduction gear 36a and the reduction gear 37a. Thus, the rotational power of the motor shaft 23a (see FIG. 14) is reduced in speed and transmitted to the output shaft 37, causing the cutting tool 11 to rotate.

[0058] As shown in FIGS. 4 to 7, the electric motor 23 is positioned above the first bar 51a regardless of whether the cutting tool 11 is in a vertical position and the cutting machine body 10 is in a position from top dead center to bottom dead center. When the cutting tool 11 is in a vertical position and the cutting machine body 10 is in a top dead center position, the shaft 32 is positioned above the first bar 51a. When the cutting tool 11 is in a vertical position and the cutting machine body 10 is in a bottom dead center position, the shaft 32 overlaps the slide bar 51 in the vertical direction. When the cutting tool 11 is in a vertical position and the cutting machine body 10 is in a top dead center position, the motor shaft 23a is inclined preferably within a range of -10° to 0° to 10° with respect to the horizontal line when the cutting tool 11 is in a vertical position and the cutting machine body 10 is in a top dead center position (a downward tilt of the side of the motor shaft 23a opposite the gear from the horizontal line (0°) is considered negative, and an upward tilt is considered positive). In this embodiment, the motor shaft 23a is parallel to the horizontal line when the cutting machine body 10 is in a top dead center position. The entire motor shaft 23a is located behind the vertical swing support shaft 10a when the cutting machine body 10 is located at the top dead center.

[0059] As shown in FIG. 6, when the cutting machine body 10 is at bottom dead center, the motor shaft 23a is inclined upward and rearward on the side opposite the gear. The inclination angle is 40° with respect to the horizontal line. When the cutting tool 11 is vertical and the cutting machine body 10 is at bottom dead center, the motor shaft 23a is inclined at an angle of 30 to 60° with respect to the horizontal line, more preferably at an angle of 35 to 45°. Therefore, the electric motor 23 is provided so as to be compact in the vertical direction even when the cutting machine body 10 is at bottom dead center. When the cutting machine body 10 is at bottom dead center, the entire motor shaft 23a is located forward of the vertical swing support shaft 10a.

[0060] 8, 10, and 14, the motor shaft 23a extends parallel to the side surface of the cutting tool 11. The angle that the motor shaft 23a forms with respect to the side surface of the cutting tool 11 is preferably -10° to 0° to 10° when viewed from the direction of extension of the cutting tool 11 and the radial direction of the motor shaft 23a (a negative angle is when the anti-gear side of the motor shaft 23a is tilted to the left with respect to parallelism (0°) with the cutting tool, and a positive angle is when it is tilted to the right). If the angle is within this range, it is only necessary to change the relative shaft angle between the meshing driving bevel gear 32e and driven bevel gear 35a, and no major changes to the design concept, such as adding parts, are necessary.

[0061] As shown in FIG. 10, the motor shaft 23a, which is the center of the electric motor 23, is located to the right of the cutting tool 11 and to the left of the slide bar 51 when the cutting tool 11 is vertical and the cutting machine body 10 is at the top dead center. The motor shaft 23a is preferably located at a position that is 30 to 50% of the distance from the first imaginary plane S1 to the second imaginary plane S2, starting from the first imaginary plane S1 and extending to the right in the direction perpendicular to the surface of the cutting tool 11, for example, at a position that is 43% of the distance. The distance from the first imaginary plane S1 to the motor shaft 23a is, for example, 56.2 mm. When the distance from the first imaginary plane S1 to the second imaginary plane S2 is 132 mm, 56.2 mm / 132 mm=43%.

[0062] As shown in Figures 8 and 10, the cutting machine body 10 has a handle portion 40 located to the right of the side surface of the cutting tool 11 and in front of the gear housing 33 when the cutting tool 11 is in a vertical position. A loop-shaped operating handle 41 extending in the left-right direction, approximately perpendicular to the side surface of the cutting tool 11, is provided at the front of the handle portion 40. A switch lever 42 is provided on the inner periphery of the operating handle 41. A user can hook their finger on the switch lever 42 while holding the operating handle 41 and pull it. Pulling the switch lever 42 starts the electric motor 23, causing the cutting tool 11 to rotate. A lock-off button 43 is provided on the front of the operating handle 41. Pressing the lock-off button 43 enables the switch lever 42 to be pulled. This prevents the electric motor 23 from being started unexpectedly.

[0063] As shown in Fig. 10, the left-right center 41a of the operating handle 41 is located between the first imaginary plane S1 and the second imaginary plane S2 in the left-right direction when the cutting tool 11 is vertical and the cutting machine body 10 is at the top dead center. The center 41a is preferably located at a position that is 30 to 70% of the distance from the first imaginary plane S1 to the second imaginary plane S2, starting from the first imaginary plane S1 and extending to the right in the direction perpendicular to the first imaginary plane S1, for example, at a position that is 70% of the distance. The distance from the first imaginary plane S1 to the center 41a is, for example, 92 mm. When the distance from the first imaginary plane S1 to the second imaginary plane S2 is 132 mm, 92 mm / 132 mm = 70%.

[0064] As shown in Figures 4, 5, and 8, the handle unit 40 has a carrying handle 44 behind the operating handle 41. The carrying handle 44 is loop-shaped, with a first connecting portion 44a at one end and a second connecting portion 44b at the other end. The first connecting portion 44a is connected to the rear of the operating handle 41, which extends to the right of the fixed cover 12. The second connecting portion 44b is connected to the top of the front housing 22. When the cutting tool is vertical, the carrying handle 44 extends forward and backward along the motor shaft 23a. When the cutting tool body 10 is moved to its bottom dead center position, the carrying handle 44 extends generally horizontally. With the cutting tool body 10 locked at its bottom dead center by the bottom dead center lock pin 19, the user can carry the bench cutter 1 by grasping the carrying handle 44.

[0065] As shown in FIGS. 1 and 4 , a turntable fixing mechanism 60 is provided at the bottom of the table extension 5. A grip 61 is provided at the front of the table extension 5. The grip 61 has an uneven periphery to allow the user to easily grip and rotate the turntable 4. The user can grasp the grip 61 to rotate the turntable 4 horizontally relative to the base 2. A fixed rod 62 extends forward and backward from the grip 61 toward the rear of the table extension 5. The fixed rod 62 is supported inside the table extension 5 by a threaded engagement. The grip 61 is rotatable around the fixed rod 62 as its axis. Rotating the grip 61 around the axis of the fixed rod 62 displaces the fixed rod 62 forward and backward. By displacing the fixed rod 62 rearward and engaging its rear end with the base 2, the turntable 4 can be positioned at any miter angle relative to the base 2. By displacing the fixed rod 62 forward, the positioning of the turntable 4 at any miter angle can be released.

[0066] As shown in FIGS. 4 and 5 , a positive lock mechanism 63 is provided at the bottom of the table extension 5. By using the positive lock mechanism 63, the turntable 4 can be positioned at a predetermined miter angle corresponding to the positioning recess 7b of the miter scale plate 7. The positive lock mechanism 63 is provided with a lock release lever 64 and a positioning pin 64a. The lock release lever 64 is provided rearward and below the grip portion 61 at the front of the table extension 5. The positioning pin 64a extends in the front-to-rear direction along the longitudinal direction of the table extension 5 at the bottom of the table extension 5. The positioning pin 64a is provided at approximately the same height as the miter scale plate 7. The rear end of the positioning pin 64a can enter the positioning recess 7b by displacing it rearward. Furthermore, the rear end of the positioning pin 64a can disengage from the positioning recess 7b by displacing it forward.

[0067] The front portion of the positioning pin 64a shown in FIGS. 4 and 5 is connected to the unlocking lever 64. When the unlocking lever 64 is pressed downward, the positioning pin 64a is displaced forward. The rear end of the positioning pin 64a displaced forward is disengaged from the positioning recess 7b. Therefore, when the positioning of the turntable 4 is released by operating the grip portion 61, the turntable 4 can be freely rotated left and right. When the unlocking lever 64 is raised upward, the positioning pin 64a is displaced rearward. The rear end of the positioning pin 64a abuts against the outer peripheral edge of the miter scale plate 7. When the grip portion 61 is gripped and the turntable 4 is rotated horizontally, the positioning pin 64a enters one of the positioning recesses 7b provided on the outer peripheral edge of the miter scale plate 7. Thus, the turntable 4 is positioned at a predetermined miter angle corresponding to the positioning recess 7b.

[0068] As shown in Figures 4 and 5, a tilt lock mechanism 65 is provided at the front of the table extension 5 to hold the main body support arm 50 in a position that allows it to tilt left and right. The tilt lock mechanism 65 has a tilt lock operation unit 66 and a transmission shaft 66a (see Figure 13). The tilt lock operation unit 66 is provided between the grip unit 61 and the front end of the table extension 5. The tilt lock operation unit 66 can be rotated around an axis that is coaxial with the grip unit 61. The tilt lock operation unit 66 has a concave-convex shape on its periphery that has a different pattern from the concave-convex shape of the grip unit 61 to make it easier for the user to grip and rotate it. This allows the user to easily distinguish between the tilt lock operation unit 66 and the grip unit 61 when holding it, preventing erroneous operation.

[0069] When the tilting and fixing operation unit 66 shown in FIGS. 4 and 5 is rotated, the transmission shaft 66a (see FIG. 13) rotates around its axis. The transmission shaft 66a extends in the longitudinal direction of the table extension 5 to the bottom of the main body support arm 50. A receiving portion 67 is provided at the bottom of the main body support arm 50, and is movable along an elongated hole 67a (see FIG. 13) that extends in an arc around the left-right tilting support shaft 50a. The receiving portion 67 is screwed to the rear end of the transmission shaft 66a. The side surface of the elongated hole 67a restricts the rotation of the receiving portion 67 around the axis of the transmission shaft 66a. Therefore, when the tilting and fixing operation unit 66 is rotated in the tightening direction, an axial force is generated in the transmission shaft 66a between the main body support arm 50 and the arm support portion 4b. This presses the main body support arm 50 and the arm support portion 4b in the longitudinal direction, and the main body support arm 50 is fixed at any left-right tilt angle relative to the arm support portion 4b. When the tilt fixing operation part 66 is rotated in the loosening direction, the axial force of the transmission shaft 66a is released, and the main body support arm 50 becomes tiltable in the left-right direction around the left-right tilt support shaft 50a.

[0070] As described above, the bench cutter 1 has a long slide bar 51 extending in the front-rear direction as shown in FIGS. 4 and 10 . The bench cutter 1 has a slide base 52 attached to the slide bar 51 and sliding in the front-rear direction along the slide bar 51. The bench cutter 1 has a cutting machine body 10 attached to the slide base 52 so as to be swingable up and down about a vertical swing support shaft 10a. The cutting machine body 10 has an output shaft 37 extending in an axial direction perpendicular to the slide bar 51 and to which the cutting tool 11 is attached. The cutting machine body 10 has an electric motor 23 as a power source for driving the output shaft 37. The electric motor 23 is located between the cutting tool 11 and the slide bar 51 when viewed from the front and is positioned above the slide bar 51 when the cutting tool 11 is in a vertical position. The cutting machine body 10 has a power transmission unit 30 that transmits the driving force of the motor shaft 23a of the electric motor 23 to the output shaft 37. The power transmission unit 30 is provided between the cutting tool 11 and the slide bar 51 when viewed from the front, and is located above the slide bar 51 when the cutting machine body 10 is located at the top dead center.

[0071] Therefore, by providing the power transmission unit 30 between the electric motor 23 and the output shaft 37, the electric motor 23 can be positioned above the slide bar 51 regardless of whether the cutting machine body 10 is at top dead center or bottom dead center. This allows the cutting tool 11 to be positioned closer to the slide bar 51. As a result, when the cutting machine body 10 is at top dead center, the electric motor 23 and the power transmission unit 30 are positioned above the slide bar 51. This allows the cutting position of the cutting tool 11 to be easily seen when the cutting machine body 10 is at top dead center.

[0072] As shown in Figures 7 and 14, the power transmission unit 30 has a shaft 32 that transmits driving force from the motor shaft 23a to the output shaft 37. When the cutting machine body 10 is at bottom dead center, the shaft 32 intersects with the slide bar 51 as viewed from the axial direction. Therefore, when the cutting machine body 10 is at bottom dead center, the shaft 32 is located between the cutting tool 11 and the slide bar 51 as viewed from the front. The electric motor 23 is located above the shaft 32 and above the slide bar 51. This makes it possible to shorten the distance between the cutting tool 11 and the slide bar 51 in the axial direction of the output shaft 37. This allows the mechanical rigidity of the cutting machine body 10 to be maintained high, and prevents a decrease in the cutting accuracy of the cutting tool 11.

[0073] 14, the diameter 32c of the shaft 32 is 1 / 40 to 1 / 20 of the diameter 11a of the cutting tool 11. Therefore, the shaft 32 can be provided with the strength required to support the electric motor 23, and the distance between the cutting tool 11 and the slide bar 51 in the axial direction of the output shaft 37 can be shortened.

[0074] 4 and 14, the motor has a cylindrical shaft housing 31 that houses the shaft 32. The shaft housing 31 has a gear housing connecting portion 31b that expands in the radial direction of the shaft 32 around the driven-side end of the shaft 32 that is connected to the output shaft 37. This allows the shaft housing 31 to be axially secured to the gear housing 33 on the output shaft 37 side with screws. This improves assembly ease and increases the support rigidity of the shaft housing 31.

[0075] 10, the distance in the axial direction of the output shaft 37 from the cutting tool 11 to the slide bar 51 is ¾ or less of the diameter 11a of the cutting tool 11. Therefore, the distance in the axial direction of the output shaft 37 from the cutting tool 11 to the slide bar 51 can be minimized to increase the mechanical rigidity of the cutting machine body 10 supported by the slide bar 51. As a result, vibration of the cutting tool 11 in the axial direction of the output shaft 37 can be suppressed when the cutting tool 11 is cut into the workpiece.

[0076] As shown in Figures 5 to 7, when the cutting machine body 10 is at the bottom dead center, the entire electric motor 23 is located between the output shaft 37 and the vertical swing support shaft 10a in the front-to-rear direction. Therefore, the center of gravity of the cutting machine body 10 at the bottom dead center can be moved closer to the vertical swing support shaft 10a. This reduces the fluctuating load when the cutting machine body 10 swings up and down. The cutting machine body 10 is urged from the bottom dead center toward the top dead center by a torsion spring attached around the vertical swing support shaft 10a. By reducing the fluctuating load of the cutting machine body 10, the spring load of the torsion spring can be reduced. Furthermore, the mechanical rigidity of the cutting machine body 10 centered around the vertical swing support shaft 10a can be increased.

[0077] 4, when the cutting machine body 10 is at the top dead center, the entire electric motor 23 is located behind the vertical swing support shaft 10a. Therefore, the load of the electric motor 23 can be used to swing the cutting machine body 10 upward and return it to the top dead center. This allows the spring load of the torsion spring that urges the cutting machine body 10 toward the top dead center to be reduced.

[0078] 10 and 14, when the cutting tool 11 is in a vertical position, the motor shaft 23a is parallel to the side surface of the cutting tool 11 or inclined at an angle of 10° or less relative to the side surface when viewed from the radial direction of the motor shaft 23a. Therefore, the motor shaft 23a can be arranged in a position that is aligned with the side surface of the cutting tool 11. As a result, the electric motor 23 can be arranged close to the cutting tool 11 in the axial direction of the output shaft 37. This allows the cutting machine body 10 to be made compact in the axial direction of the output shaft 37.

[0079] As shown in Fig. 10, the motor shaft 23a, which is the center of the electric motor 23, is arranged at a position 30 to 50% of the distance from the tool 11 to the slide bar 51 in the plane direction of the tool 11 starting from the tool 11. Therefore, the motor shaft 23a is arranged closer to the tool 11 than the slide bar 51. Thus, the center of gravity of the cutting machine main body 10 can be brought closer to the tool 11 in the axial direction of the output shaft 37. As a result, when the cutting machine main body 10 is moved downward to cut the tool 11 into the workpiece, the torsional moment caused by the reaction force received by the tool 11 from the workpiece and the weight of the cutting machine main body 10 can be reduced.

[0080] As shown in Figs. 10 and 14, the electric motor 23 is a brushed motor that is driven by power supplied from an AC power source. Therefore, even when a brushed motor with a relatively large motor diameter is provided, it is possible to suppress the visibility being obstructed by the brushed motor when checking the cutting position of the tool 11. Also, even when a brushed motor is provided, the distance between the tool 11 and the slide bar 51 in the axial direction of the output shaft 37 can be shortened.

[0081] As shown in Fig. 4, the slide bar 51 has a plurality of bars arranged in parallel. The plurality of bars includes a first bar 51a located at the uppermost position and a second bar 51b located at the lowermost position. When the diameter 51e of the first bar 51a is a [mm], the diameter 51f of the second bar 51b is b [mm], the center-to-center distance 51g between the first bar 51a and the second bar 51b is c [mm], and the diameter 11a of the tool 11 is d [mm], the relationship (a / 2 + b / 2 + c) × 2 < d < (a / 2 + b / 2 + c) × 3.5 is satisfied. Therefore, the plurality of bars can be compactly accommodated within a range of a length shorter than half of the diameter 11a of the tool 11 in the vertical direction. Moreover, the vertical distance including all of the plurality of bars is larger than 2 / 7 times the diameter 11a of the tool 11. Therefore, a plurality of bars can be provided so as to have sufficient strength to support the cutting machine main body 10. Thus, it is possible to achieve both the compactness and the support strength of the slide structure of the cutting machine main body 10.

[0082] 5 to 7, the motor shaft 23a is oriented at an angle that tilts upward and rearward when the cutting machine body 10 is at the bottom dead center. Therefore, when the cutting machine body 10 is at the bottom dead center, the amount of downward protrusion of the electric motor 23 can be minimized. This allows the bench cutter 1 to be made compact in the vertical direction.

[0083] 5 to 7, the inclination angle of the motor shaft 23a is 30° to 60° with respect to the horizontal when the cutting machine body 10 is at the bottom dead center. This prevents the motor housing 20 that houses the electric motor 23 from coming into contact with the workpiece. This allows the compact bench cutter 1 to be used to suitably cut the workpiece.

[0084] As shown in Figure 4, when the cutting machine body 10 is at the top dead center, the motor shaft 23a is parallel to the horizontal line or has an inclination angle of 10° or less with respect to the horizontal line. This makes it possible to reduce the amount of upward or downward protrusion of the electric motor 23. This prevents obstruction to visibility when checking the cutting position of the cutting tool 11.

[0085] As shown in FIGS. 8 and 10 , the bench cutter 1 has an operating handle 41 used to move the cutting machine body 10 relative to the slide bar 51. The center 41a of the operating handle 41 is located on an imaginary plane including the cutting tool 11 when viewed from the front with the cutting tool 11 in a vertical position, or is located between the slide bar 51 and the cutting tool 11. Therefore, the centers 41a of the slide bar 51 and the operating handle 41 can be brought closer to the axial direction of the output shaft 37. This reduces the torsional moment of the cutting machine body 10 relative to the slide bar 51 when a user grips the operating handle 41 and drives the cutting tool 11 into a workpiece. Furthermore, the centers 41a of the cutting tool 11 and the operating handle 41 can be brought closer to the axial direction of the output shaft 37. This reduces the torsional moment caused by the reaction force acting on the cutting tool 11 from the workpiece and the operating force exerted when operating the operating handle 41 when a user grips the operating handle 41 and drives the cutting tool 11 into the workpiece.

[0086] As shown in Figure 10, the center 41a of the operating handle 41 is located at a position that is 30 to 70% of the distance from the cutting tool 11 to the slide bar 51 in the axial direction, starting from the cutting tool 11. Therefore, the center 41a of the operating handle 41 is located at a position that is not too far from both the cutting tool 11 and the slide bar 51. This makes it possible to reduce the torsional moment of the cutting machine body 10 that acts between the cutting tool 11 and the operating handle 41. Furthermore, it is possible to suppress deflection of the slide bar 51 due to the operating force applied when operating the operating handle 41.

[0087] As shown in Figure 13, the bench cutter 1 has a bottom dead center stopper 17 that prevents the cutting machine body 10 from moving below the bottom dead center. When the cutting tool 11 is in a vertical position, the center 17a of the bottom dead center stopper 17 is located between the slide bar 51 and the cutting tool 11 as viewed from the front. This allows the distance between the center 17a of the bottom dead center stopper 17 and the slide bar 51 in the axial direction of the output shaft 37 to be shortened. The bottom dead center stopper 17 receives a reaction force when the cutting machine body 10 descends to the bottom dead center. Therefore, by shortening the distance, the torsional moment of the cutting machine body 10 relative to the slide bar 51 caused by the reaction force can be reduced.

[0088] 13, the center 17a of the bottom dead center stopper 17 is located at a position that is 30 to 70% of the distance from the cutting tool 11 to the slide bar 51 in the axial direction, starting from the cutting tool 11. Therefore, the center 17a of the bottom dead center stopper 17 is located at a position that is not too far from both the cutting tool 11 and the slide bar 51. This makes it possible to reduce the reaction force received by the bottom dead center stopper 17 and the torsional moment of the cutting machine body 10 that acts between the slide bar 51 and the reaction force received by the bottom dead center stopper 17, and also to suppress wobbling of the cutting tool 11 due to the torsional moment.

[0089] Next, a second embodiment of the present disclosure will be described with reference to Figures 16 to 21. A bench cutter 70 has a cutting machine body 71 instead of the cutting machine body 10 of the bench cutter 1 shown in Figure 1. The cutting machine body 71 is supported on the slide base 52 so as to be able to swing up and down about a vertical swing support shaft 71a located behind the cutting tool 11. The cutting machine body 10 is provided with a motor housing 73 that houses an electric motor 74, and a battery mounting portion 78 to which a rechargeable battery 79 can be attached.

[0090] 16 and 20, the motor housing 73 is provided between the cutting tool 11 and the slide bar 51 in the left-right direction. The motor housing 73 has a generally cylindrical shape extending in the front-rear direction. The electric motor 74 is a motor known as a DC brushless motor that is powered by a DC power source such as a battery 79. A motor shaft 74a is provided in the center of the electric motor 74. The motor shaft 74a extends in the front-rear direction along a motor axis J that is parallel to the side surface of the cutting tool 11. The left-right position and extension direction of the motor axis J between the cutting tool 11 and the slide bar 51 are generally the same as those of the motor axis J shown in FIG.

[0091] As shown in Figure 21, the motor shaft 74a is supported by a first bearing 74g and a second bearing 74h so as to be rotatable about the motor axis J. The inner ring of the first bearing 74g is press-fitted onto the rear end of the motor shaft 74a, and the outer ring is press-fitted into a hole provided at the inside rear end of the motor housing 73. The inner ring of the second bearing 74h is press-fitted onto the front part of the motor shaft 74a, and the outer ring is press-fitted into a hole 81c provided at the rear end of the gear housing 81 (described later). The second bearing 74h is prevented from coming off from the hole 81c by a washer 74i.

[0092] As shown in FIG. 21 , a stator 74c of the electric motor 74 is non-rotatably supported on the inner circumferential surface of the motor housing 73. A rotor 74b of the electric motor 74 is disposed on the inner circumferential side of the stator 74c. The rotor 74b is attached along the outer periphery of the motor shaft 74a and is rotatable together with the motor shaft 74a. A sensor board 74d for detecting the rotation angle of the rotor 74b is provided behind the rotor 74b. A fan 75 for introducing cooling air into the motor housing 73 is integrally attached to the front of the motor shaft 74a between the rotor 74b and the second bearing 74h in the front-to-rear direction. When the electric motor 74 is driven and the fan 75 rotates, cooling air flows from the rear of the motor housing 73 to the front.

[0093] As shown in Figure 20, the cutting machine body 71 has a power transmission unit 80 that transmits the driving force of the motor shaft 74a to the output shaft 37 between the cutting tool 11 and the slide bar 51 in the left-right direction. The power transmission unit 80 is housed in a gear housing 81 and a gear accommodating portion 12a provided on the right side of the fixed cover 12. The gear housing 81 connects an opening at the front end of the motor housing 73 with an opening at the right end of the gear accommodating portion 12a.

[0094] As shown in Figure 21, the gear housing 81 has a motor housing connecting portion 81a that opens rearward at the rear end and a fixed cover connecting portion 81b that opens leftward at the left side, and these portions are connected to each other internally. The front end 73a of the motor housing 73 and the motor housing connecting portion 81a at the rear end of the gear housing 81 are connected by a plurality of fixing screws 81e (see Figure 17) that extend along the direction of the motor axis J. A drive-side bevel gear 74e is attached integrally to the front end of the motor shaft 74a. A nut 74f is attached in front of the drive-side bevel gear 74e to prevent it from coming off. The drive-side bevel gear 74e is inserted into the gear housing 81.

[0095] As shown in Figure 21, the fixed cover connecting portion 81b is connected by a spigot joint that covers the outer periphery of the gear housing connecting portion 12d. The fixed cover connecting portion 81b and the gear housing connecting portion 12d are connected by a plurality of fixing screws 81f that extend in a direction substantially perpendicular to the side surface of the cutting tool 11. A first intermediate shaft 35, a second intermediate shaft 36, and an output shaft 37 are supported by the gear housing 81 and the gear accommodating portion 12a so as to be rotatable around axes that extend in the left-right direction. A bearing box 34 is connected to the left side surface of the gear housing 81 by a plurality of fixing screws 34d that extend in a direction substantially perpendicular to the side surface of the cutting tool 11.

[0096] As shown in FIG. 21 , a hole 81d is provided on the right side inside the gear housing 81. The outer ring of the fifth bearing 35c, which is press-fitted onto the right end of the first intermediate shaft 35, is press-fitted into the hole 81d. The driven-side bevel gear 35a attached to the right side of the first intermediate shaft 35 meshes with the drive-side bevel gear 74e of the motor shaft 74a. Both the second bearing 74h and the fifth bearing 35c are positioned in the holes 81c, 81d provided in the gear housing 81, thereby enabling the motor shaft 74a and the first intermediate shaft 35 to be positioned with high precision. Furthermore, the meshing between the drive-side bevel gear 74e and the driven-side bevel gear 35a can be performed with high precision.

[0097] 17 and 18, when the cutting tool 11 is vertical and the cutting machine body 71 is at top dead center, the electric motor 74 and the power transmission unit 80 are located above the first bar 51a. The motor shaft 74a is parallel to the horizontal when the cutting machine body 71 is at top dead center. When the cutting machine body 71 is at top dead center, the motor shaft 74a is located forward of the vertical swing support shaft 71a.

[0098] 19 and 20, when the cutting tool 11 is in a vertical position and the cutting machine body 71 is at bottom dead center, the electric motor 74 and power transmission unit 80 overlap the slide bar 51 in the vertical direction. When the cutting machine body 71 is at bottom dead center, the motor shaft 74a tilts upward and rearward on the side opposite the gear. The tilt angle is in the range of 30 to 60 degrees with respect to the horizontal line, more preferably in the range of 35 to 45 degrees, for example, 40 degrees. The entire motor shaft 74a is located forward of the vertical swing support shaft 71a even when the cutting machine body 71 is at bottom dead center.

[0099] As shown in FIGS. 17 and 21 , a rectangular box-shaped controller housing 76 is connected to the rear of the motor housing 73. The second connecting portion 44b of the carrying handle 44 is connected to the top of the controller housing 76. The controller housing 76 houses a controller 77 that controls the operation of the electric motor 74. The controller 77 has a shallow, approximately rectangular parallelepiped case and a resin-molded control board housed within the case. The controller 77 is housed in the controller housing 76 with its thickness (the direction in which the shortest side of the case extends) aligned with the longitudinal direction in which the motor axis J extends. The controller 77 is equipped with a control circuit, a drive circuit, an auto-stop circuit, and other components that primarily control the operation of the electric motor 74. The control circuit has a microcomputer that transmits control signals to the electric motor 74 based on position information of the rotor 74b obtained by the sensor board 74d. The drive circuit has an FET that switches the current of the electric motor 74 based on the control signal received from the control circuit. The auto-stop circuit cuts off the power supply to the electric motor 74 in response to the detection result of the state of the battery 79 to prevent over-discharge or over-current.

[0100] As shown in FIGS. 17 and 21 , a battery mounting portion 78 is provided at the rear of the controller housing 76. When the cutting machine body 71 is positioned at the top dead center, the mounting surface of the battery mounting portion 78 faces rearward and extends generally perpendicular to the motor axis J. A battery 79 having a substantially rectangular box shape can be attached to the battery mounting portion 78 by sliding it from top to bottom. The battery 79 can also be removed from the battery mounting portion 78 by sliding it from bottom to top. The battery 79 is, for example, a lithium-ion battery with an output voltage of 36 V. The battery 79 can be removed from the battery mounting portion 78 and repeatedly charged using a separately provided charger. The battery 79 can be shared as a power source for other rechargeable power tools, such as a screwdriver or an electric drill.

[0101] As described above, the bench cutter 70 has a long slide bar 51 extending in the front-to-rear direction as shown in FIGS. 4 and 20 . The bench cutter 70 has a slide base 52 attached to the slide bar 51 and sliding in the front-to-rear direction along the slide bar 51. The bench cutter 70 has a cutting machine main body 71 attached to the slide base 52 so as to be able to swing up and down about a vertical swing support shaft 71a. The cutting machine main body 71 has an output shaft 37 extending in an axial direction perpendicular to the slide bar 51 and to which the cutting tool 11 is attached. The cutting machine main body 71 has an electric motor 74, which is a power source for driving the output shaft 37, and is located between the cutting tool 11 and the slide bar 51 when viewed from the front and above the slide bar 51 when the cutting tool 11 is in a vertical position. The cutting machine main body 71 has a power transmission unit 80 that transmits the driving force of the motor shaft 74a of the electric motor 74 to the output shaft 37. The power transmission unit 80 is located between the cutting tool 11 and the slide bar 51 when viewed from the front, and is located above the slide bar 51 when the cutting machine body 71 is at the top dead center. Therefore, the bench cutter 70 has the same effect as the bench cutter 1 shown in Figures 4 and 10. That is, the cutting tool 11 can be positioned closer to the slide bar 51. Furthermore, when the cutting machine body 71 is at the top dead center, the cutting position of the cutting tool 11 is easily visible.

[0102] Various modifications can be made to the bench cutters 1, 70 of the present embodiment described above. The cutting machine body 10, 71 is supported by a slide bar 51 attached to the body support arm 50 so that it can move back and forth. The body support arm 50 is supported so that it can tilt relative to the arm support portion 4b of the turntable 4. Alternatively, the body support arm 50 may be directly supported on the base 2 or the mounting surface. This invention can also be applied to bench cutters that do not have a left-right tilt angle adjustment mechanism that allows the cutting machine body 10, 71 to tilt left and right, or a miter angle adjustment mechanism that allows the turntable 4 to rotate horizontally relative to the base 2.

[0103] The cutting machine body 10, 71 may be arranged in the opposite left-right direction to that disclosed in the present disclosure. That is, the cutting tool 11 may be arranged on the right side, the slide bar 51 may be arranged on the left side, and the electric motor 23, 74, the handle 40, the bottom dead center stopper 17, etc. may be arranged between the cutting tool 11 and the slide bar 51 in the left-right direction.

[0104] While the slide bar 51 including two bars 51a, 51b has been exemplified, the number of bars may be one, or three or more bars arranged side by side. The slide bar 51 may be non-parallel to the side of the cutting tool 11. The slide bar 51 may be non-parallel to the horizontal line. The electric motors 23, 74 have been exemplified in which the motor axis J is parallel to the horizontal line when the cutting machine body 10, 71 is positioned at the top dead center. Alternatively, the motor axis J may extend upward or downward toward the opposite gear side (rear) when the cutting machine body 10, 71 is positioned at the top dead center.

[0105] In the illustrated power transmission unit 30, 80, power is transmitted to the output shaft 37 after being reduced in two stages by the reduction gear 35b of the first intermediate shaft 35 and the reduction gear 36a of the second intermediate shaft 36. Alternatively, for example, only one intermediate shaft or three or more intermediate shafts may be provided. In the illustrated configuration, the operating handle 41 has a loop shape extending in the left-right direction. Alternatively, the operating handle 41 may have a loop shape extending in the front-rear direction, for example, parallel to the motor axis J. In the illustrated configuration, the top dead center stopper 18 is provided to the left of the fixed cover 12. Alternatively, the top dead center stopper 18 may be provided between the cutting tool 11 and the slide bar 51 in the left-right direction, similar to the bottom dead center stopper 17. [Explanation of symbols]

[0106] 1...Benchtop cutting machine 2...base, 2a...rotating support shaft 3...Upward protrusion 4...Turntable, 4a...Table top surface, 4b...Arm support portion 5...table extension, 5a...slot 6...positioning fence, 6a...upper extension fence, 6b...positioning surface 7...Miter scale plate, 7a...Fixing screw, 7b...Positioning recess 8...Indicator 9...Knob 10...cutting machine body, 10a...up and down swing support shaft 11...cutting tool, 11a...diameter 12...Fixed cover, 12a...Gear accommodating portion, 12b, 12c...Hole portion 12d...Gear housing connection part 13... Movable cover 14...Fixing screw 15...Outer flange 16...Inner flange 17...Bottom dead center stopper, 17a...Center 18...Top dead center stopper 19...bottom dead center lock pin, 19a...through hole 20...Motor housing 21... rear housing, 21a... front end, 21b... fixing screw 22...front housing, 22a...rear end, 22b...shaft support portion, 22c, 22d...hole portion 22e...Fixing screw 23...electric motor, 23a...motor shaft, 23b...stator, 23c...rotor 23d... Commutator, 23e... First bearing, 23f... Second bearing 24...Fan 25...Power cord 30...Power transmission section 31... shaft housing, 31a... motor housing connection portion 31b... Gear housing connecting portion (expanded diameter portion) 32...shaft, 32a...driving end, 32b...driven end, 32c...diameter 32d...Connecting sleeve, 32e...Drive bevel gear, 32f...Nut 32g...3rd bearing, 32h...4th bearing, 32i...washer, 32j...length 33... gear housing, 33a... shaft housing connecting portion 33b...fixed cover connecting portion, 33c, 33d...hole portion 33e, 33f...Fixing screws 34... bearing box; 34a, 34b, 34c... holes; 34d... fixing screw 35...first intermediate shaft, 35a...driven bevel gear, 35b...reduction gear, 35c...fifth bearing 35d...6th bearing, 35e...washer, 35f...rubber ring, 35g...washer 35h...wheel chock 36...second intermediate shaft, 36a...reduction gear, 36b...seventh bearing, 36c...eighth bearing 37...output shaft, 37a...reduction gear, 37b...ninth bearing, 37c...tenth bearing 40...Handle 41...operating handle, 41a...center 42...Switch lever 43...Lock-off button 44...carrying handle, 44a...first connecting portion, 44b...second connecting portion 50...Main body support arm, 50a...Right and left tilting support shaft, 50b...Upper part 51...slide bar, 51a...first bar, 51b...second bar, 51c, 51d...center 51e, 51f…Diameter, 51g…Center distance 52... slide base, 52a... bottom dead center stopper abutment portion, 52b... top dead center stopper abutment portion 60...Turntable fixing mechanism 61...Grip section 62...Fixed rod 63...Positive lock mechanism 64...lock release lever, 64a...positioning pin 65…Tilt fixation mechanism 66...tilt fixing operation part, 66a...transmission shaft 67...receiving portion, 67a...long hole 70...Benchtop cutting machine 71...cutting machine body, 71a...up and down swing support shaft 73...motor housing, 73a...front end 74...electric motor, 74a...motor shaft, 74b...rotor, 74c...stator 74d...sensor board, 74e...drive side bevel gear, 74f...fixing screw, 74g...first bearing 74h...2nd bearing, 74i...washer 75...Fan 76...Controller housing 77...Controller 78...Battery mounting part 79...Battery 80...Power transmission section 81... gear housing, 81a... motor housing connecting portion, 81b... fixed cover connecting portion 81c, 81d...holes, 81e, 81f...fixing screws J: Motor axis S1: First virtual plane S2: Second virtual plane

Claims

1. A benchtop cutting machine, A long slide bar extending in the front-rear direction; a slide base attached to the slide bar and slidable in the front-rear direction along the slide bar; a cutting machine body mounted so as to be swingable in the up and down direction around a vertical swing support shaft provided on the slide base; The cutting machine body is an output shaft extending in an axial direction perpendicular to the slide bar and having a cutting tool attached thereto; an electric motor which is a power source for driving the output shaft, the rotor of which is located between the cutting tool and the slide bar as viewed from the front when the cutting tool is in a vertical position, and which is located above the slide bar when the cutting machine body is at the top dead center with the cutting tool in a vertical position; A bench cutter has a power transmission unit that transmits the driving force of the motor shaft of the electric motor to the output shaft, and the power transmission unit is located between the cutting tool and the slide bar when viewed from the front, and is located above the slide bar when the cutting tool is in a vertical position and the cutting machine body is at the top dead center.

2. A benchtop cutting machine, A long slide bar extending in the front-rear direction; a slide base attached to the slide bar and slidable in the front-rear direction along the slide bar; a cutting machine body mounted so as to be swingable in the up and down direction around a vertical swing support shaft provided on the slide base; The cutting machine body is an output shaft extending in an axial direction perpendicular to the slide bar and having a cutting tool attached thereto; a power source for driving the output shaft, the rotor of which is positioned between the cutting tool and the slide bar as seen from the front when the cutting tool is in a vertical position, and which is positioned above the slide bar when the cutting machine body is at the top dead center when the cutting tool is in a vertical position; When the cutting machine body is located at the bottom dead center, the entire electric motor is located between the output shaft and the vertical swing support shaft in the front-rear direction, A bench cutter in which the motor shaft of the electric motor is parallel to the side surface of the cutting tool or inclined at an angle of 10° or less relative to the side surface when viewed from the radial direction of the motor shaft when the cutting tool is in a vertical position.

3. The bench cutter according to claim 1, The power transmission unit has a shaft that transmits driving force from the motor shaft to the output shaft, and the shaft intersects with the slide bar when viewed from the axial direction when the cutting machine body is positioned at the bottom dead center.

4. The bench cutter according to claim 3, A bench cutter in which the diameter of the shaft is 1 / 40 to 1 / 20 of the diameter of the cutting tool.

5. The bench cutter according to claim 3 or 4, a cylindrical shaft housing that accommodates the shaft; The shaft housing has an expanded diameter portion that expands in the radial direction of the shaft around the driven end of the shaft that is connected to the output shaft.

6. The bench cutter according to any one of claims 1, 3 to 5, A bench cutter in which the entire electric motor is located between the output shaft and the vertical swing support shaft in the front-to-rear direction when the cutting machine body is located at the bottom dead center.

7. The bench cutter according to any one of claims 1 and 3 to 6, A bench cutter wherein the motor shaft is parallel to the side surface of the cutting tool or inclined at an angle of 10° or less relative to the side surface when viewed from the radial direction of the motor shaft when the cutting tool is in a vertical position.

8. A bench cutter according to any one of claims 1 to 7, A bench cutter, wherein the axial distance from the cutting tool to the slide bar is 3 / 4 or less of the diameter of the cutting tool.

9. A bench cutter according to any one of claims 1 to 8, A bench cutter in which the entire electric motor is located behind the vertical swing support shaft when the cutter body is at the top dead center.

10. A bench cutter according to any one of claims 1 to 9, A bench cutter in which the center of the electric motor is positioned at a position that is 30 to 50% of the distance from the cutting tool to the slide bar in a direction perpendicular to the surface of the cutting tool, with the cutting tool as the starting point.

11. A bench cutter according to any one of claims 1 to 10, The electric motor is a brushed motor that is driven by power supplied from an AC power source.

12. A bench cutter according to any one of claims 1 to 11, The slide bar has a plurality of bars arranged side by side, and the plurality of bars include a first bar located at the top and a second bar located at the bottom; When the diameter of the first bar is a [mm], the diameter of the second bar is b [mm], the center-to-center distance between the first bar and the second bar is c [mm], and the diameter of the cutting tool is d [mm], (a / 2+b / 2+c)×2<d<(a / 2+b / 2+c)×3.5 A benchtop cutting machine that meets the requirements of

13. A bench cutter according to any one of claims 1 to 12, The motor shaft is oriented at an inclination angle that is inclined upward and rearward when the cutting machine body is positioned at the bottom dead center.

14. A bench cutter according to claim 13, The inclination angle of the motor shaft is 30° to 60° with respect to the horizontal line.

15. A bench cutter according to claim 13 or 14, The motor shaft is parallel to the horizontal line or has an inclination angle of 10° or less with respect to the horizontal line when the cutting machine body is positioned at the top dead center.

16. A bench cutter according to any one of claims 1 to 15, an operating handle used when moving the cutting machine body relative to the slide bar; A bench cutter in which the center of the operating handle is located on an imaginary plane including the cutting tool when viewed from the front with the cutting tool in a vertical position, or between the slide bar and the cutting tool.

17. A bench cutter according to claim 16, A bench cutter in which the center of the operating handle is positioned at a position that is 30 to 70% of the distance from the cutting tool to the slide bar in the axial direction, with the cutting tool as the starting point.

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