Portable Cutting Machine

Abstract

To improve operability during attachment / detachment of a dust case, in a portable cutter comprising the dust case for collecting cut powder produced by cut process.SOLUTION: A dust case 30 comprises an attachment / detachment operation part 35 that is push-operated during detachment from a cutter body 10, and a finger support part 40 that includes a surface approximately orthogonal to an operational virtual line L on the front side in a push operation direction D of the attachment / detachment operation part 35. The dust case 30 can be held by pinching the attachment / detachment operation part 35 and the finger support part 40 between two finger tips F1 and F2. Consequently, operability during attachment / detachment is improved.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a portable cutting machine called a tip saw cutter (English name: METAL CUTTER or METAL CUTTING SAW) used for cutting steel plates, for example. [Background technology]

[0002] Portable cutters are equipped with a circular cutting tool that is rotated by a motor. The cutting tool is rotated and moved along the cutting area to cut the material. Cutting dust is blown upward from the area where the cutting tool cuts (cutting area). Portable cutters are designed with various features to prevent the blown dust from scattering to the surrounding area. For example, the cutting dust blown up from the cutting area is carried by the rotating wind of the cutting tool and collected in a fixed cover that surrounds the cutting tool. The cutting dust collected in the fixed cover is separated and disposed of in a bag-shaped dust bag or a box-shaped dust case. For this reason, the dust bag and dust case are detachable from the cutting machine body.

[0003] The latter technology relating to the attachment and detachment structure of the dust case is disclosed in patent documents. The dust case disclosed in patent document 1 has an attachment / detachment operating section on the back side opposite the dust case mounting surface. By engaging a rotating operating member with the dust case from the back side, the dust case is fixed along the mounting surface. The dust case can be removed by rotating the operating member on the back side to release the engagement. The dust case disclosed in patent document 2 has finger hooks on two sides and a push-type removal button on the rear. The dust case can be removed by hooking, for example, the thumb and middle finger on the two finger hooks and pressing the removal button with the index finger to release the engagement claw from the main body side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-138220 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-154510 Summary of the Invention [Problem to be solved by the invention]

[0005] The dust case of Patent Document 1 requires that the dust case be held with one hand and the operating member rotated with the other when attaching or detaching, and the need for both hands meant that the ease of attachment and detachment needed to be improved. The dust case of Patent Document 2 requires that the dust case be held with two fingertips and the removal button be pressed with the fingertips, but the fingers cannot be used to support the direction in which the removal button is pressed, which can lead to instability. This disclosure aims to improve the ease of attachment and detachment of the dust case. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a portable cutting machine includes a cutting machine body to which, for example, a circular cutting tool is attached, and a dust case that is detachable from the cutting machine body. The dust case has, for example, an attachment / detachment operation unit that is pushed on an imaginary plane parallel to the face of the cutting tool when detaching the dust case from the cutting machine body. The dust case has, for example, a finger support unit that includes a surface that is approximately perpendicular to the pushing direction and is located forward of the pushing direction of the attachment / detachment operation unit.

[0007] Therefore, the dust case can be removed by pinching the attachment / detachment operating portion and the finger support portion with the tips of two fingers, thereby improving the operability of attaching and detaching the dust case. [Brief explanation of the drawings]

[0008] [Figure 1] This is an overall perspective view of the portable cutting machine, as seen from the right rear. This figure shows the state with the dust case attached. [Figure 2]This is an overall perspective view of the portable cutting machine, as seen from the right rear. This view shows the state in the middle of removing the dust case. [Figure 3] FIG. 2 is a left side view of the dust case as seen from the inside. [Figure 4] FIG. 2 is a right side view of the portable cutting machine. [Figure 5] FIG. 1 is a top view of a portable cutting machine. [Figure 6] This is a top view of the portable cutting machine, showing the state in which the dust case is being removed. [Figure 7] FIG. 2 is a right side view of the portable cutting machine with the dust case removed. [Figure 8] FIG. 8 is a front view of the portable cutting machine as seen from the direction of arrow VIII in FIG. [Figure 9] 9 is a left side view of the portable cutting machine as seen from the direction of arrow IX in FIG. 8. [Figure 10] 10 is a rear view of the portable cutting machine as seen from the direction of arrow X in FIG. 9. [Figure 11] FIG. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII in FIG. 4, and is a horizontal cross-sectional view of the attachment / detachment operation portion. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. 4, showing a longitudinal cross-section of the portable cutting machine. [Figure 14] This is a right side view of the portable cutting machine, showing the cutting machine body displaced upward relative to the base to adjust the cutting depth to the minimum. [Figure 15] 5 is a cross-sectional view taken along line XV-XV in FIG. 4, and is a horizontal cross-sectional view of the second engagement portion. DETAILED DESCRIPTION OF THE INVENTION

[0009] In one or more embodiments, for example, the center of the area of ​​the dust case in a side view perpendicular to the cutting tool is located between the attachment / detachment operating part and the finger support part. This makes it easier to hold the dust case in a balanced manner. In particular, by locating the center of gravity near the center of the area in a side view, the dust case can be held with its side facing upward in a balanced manner.

[0010] In one or more embodiments, the portable cutter includes a base having a lower surface that contacts the workpiece, and a depth adjustment mechanism that adjusts the position of the cutter body relative to the base between the top dead center and the bottom dead center. When the cutter body is positioned at the bottom dead center, an imaginary operation line extending in the pushing direction of the attachment / detachment operation unit is inclined at an angle of, for example, 20° to 40° relative to the lower surface of the base. This makes it easier for the user to apply a pushing force to the attachment / detachment operation unit.

[0011] In one or more embodiments, the portable cutter has, for example, a first engagement portion and a second engagement portion that engage the dust case with the cutter body. The first engagement portion is provided on the attachment / detachment operation portion. The second engagement portion is provided at a position that is off an imaginary operation line that extends in the pushing direction of the attachment / detachment operation portion in a side view perpendicular to the cutting tool. This improves operability when attaching and detaching the dust case, for example, by locating the second engagement portion at a position that is off the imaginary operation line and easy to see.

[0012] In one or more embodiments, for example, the length from the attachment / detachment operating portion to the finger support portion is ±20% of the radius of the cutting tool, which makes it easier to grip the dust case.

[0013] In one or more embodiments, for example, the length from the attachment / detachment operation portion to the finger support portion is 110 mm±10 mm, which allows the dust case to be gripped easily.

[0014] In one or more embodiments, for example, the attachment / detachment operation unit has a push operation portion with a concave shape that is concave in the push operation direction. This makes it easier to apply a push operation force to the push operation portion in the push operation direction. The concave shape allows the push operation portion to be confirmed by the touch of a fingertip, thereby improving the operability of the push operation portion.

[0015] In one or more embodiments, for example, the pushing portion has a concave shape that deepens toward the cutting tool, which makes it easier to efficiently apply a pushing force in the removal direction to the pushing portion when the pushing portion is disposed above the cutting tool.

[0016] In one or more embodiments, for example, the finger support portion has a length of 50 mm±10 mm in a side view perpendicular to the cutting tool, and 20 mm±5 mm in a direction perpendicular to the surface of the cutting tool, so that the dust case can be gripped by reliably pressing the fingertips against the finger support portion.

[0017] In one or more embodiments, for example, a vertical wall portion extending perpendicular to the surface of the cutting tool is provided on the upper portion of the finger support portion, which prevents the fingertips from slipping on the finger support portion and improves the grip of the finger support portion.

[0018] In one or more embodiments, for example, the cutter body has a handle portion. An imaginary operation line extending in the pushing direction of the attachment / detachment operation portion passes through, for example, the grip portion of the handle portion. This improves operability when holding the handle portion with one hand while attaching or detaching the dust case with the other hand.

[0019] In one or more embodiments, for example, a portable cutter has a first engagement portion and a second engagement portion that engage the dust case with the cutter body. The first engagement portion is provided at the rear of the dust case in the cutting direction. The second engagement portion is provided at the front of the dust case in the cutting direction. A mark indicating the position of the second engagement portion is provided on the front of the dust case. This makes it easier to attach the dust case. [Example]

[0020] In this embodiment, a handheld cutting machine known as a chip saw cutter is exemplified as a portable cutting machine. Chip saw cutters are used primarily for cutting metal materials, such as metal pipes and aluminum drawing materials. As shown in FIGS. 4, 8, 9, and 10, the portable cutting machine 1 of this embodiment has a rectangular, flat base 2 that abuts against the top surface of the workpiece W, and a cutting machine body 10 supported on the top surface of the base 2. The cutting machine body 10 is supported on the base 2 via a support shaft 3 so that it can rotate up and down. The cutting depth of the cutting tool 12 can be adjusted by changing the position of the cutting machine body 10 up and down relative to the base 2. The cutting depth adjustment mechanism will be described later.

[0021] The cutting machine body 10 has a circular cutting tool 12 that is rotated by an electric motor 11. The cutting tool 12 is, for example, a circular saw blade known as a chip saw. The electric motor 11 and cutting tool 12 are supported by a main body housing 13. The electric motor 11 is supported on the left side of the main body housing 13. The electric motor 11 is a DC brushless motor that operates on a direct current power source.

[0022] As shown in Figures 5 and 13, the electric motor 11 is housed in a cylindrical motor housing 14. A stator 11a is attached along the inner surface of the motor housing 14. A rotor 11d is rotatably supported on the inner periphery of the stator 11a via a motor shaft 11b. A cooling fan 11c is attached to the motor shaft 11b. As shown in Figures 9 and 13, multiple air intakes 14a are provided on the left end surface of the motor housing 14. When the cooling fan 11c rotates, outside air is introduced into the motor housing 14 through the air intakes 14a. The introduced outside air cools the electric motor 11.

[0023] 13, motor cooling air Z for the electric motor 11 flows through the main body housing 13 and into the dust case 30. Details will be described later.

[0024] The motor shaft 11b is connected to a reduction gear train 16. A spindle 16a of the reduction gear train 16 protrudes into the fixed cover portion 13a. The cutting tool 12 is attached to the spindle 16a inside the fixed cover portion 13a. The cutting tool 12 is attached to the spindle 16a and sandwiched between an outer flange 12a and an inner flange 12b in the thickness direction. The rotation output of the electric motor 11 is reduced in speed by the reduction gear train 16 and output to the spindle 16a. This causes the cutting tool 12 to rotate.

[0025] As shown in Figure 9, a spindle lock lever 26 is provided near the connection between the electric motor 11 and the reduction gear train 16. When the spindle lock lever 26 is pressed, for example, the spindle lock lever 26 engages with the motor shaft 11b, locking the spindle 16a so that it cannot rotate. This facilitates the tightening and loosening of the fixing screw for attaching and detaching the cutting tool 12 to the spindle 16a.

[0026] The fixed cover portion 13a is provided to protrude so as to cover the periphery of the cutting tool 12 mainly along the upper half of the circumference of the cutting tool 12. The lower side of the cutting tool 12 protrudes toward the lower surface 2a of the base 2. The periphery of the lower side of the cutting tool 12 is covered by a movable cover 25. The movable cover 25 is provided along the periphery of the cutting tool 12 so as to be able to open and close.

[0027] As shown in Figure 5, the controller 15 is housed behind the electric motor 11. The controller 15 is a shallow case 15a housing a control board 15b and is insulated with a resin mold 15c, and in this example has a roughly rectangular flat plate shape. As shown in Figures 5, 6, and 9, the controller 15 is housed in a vertical position with its thickness aligned with the front-to-rear direction.

[0028] The control board 15b of the controller 15 is equipped with a control circuit made up of a microcomputer that transmits control signals based on position information of the rotor 11d detected by the sensor board of the electric motor 11. The control board 15b of the controller 15 also has a drive circuit made up of an FET that switches the current of the electric motor 11 based on the control signal received from the control circuit. The control board 15b of the controller 15 also has an auto-stop circuit and the like that cuts off the power supply to the electric motor 11 in response to the detection result of the state of the battery pack 20 to prevent over-discharge or over-current.

[0029] A battery attachment section 21 is provided behind the controller 15. One battery pack 20 is attached to the battery attachment section 21. The electric motor 11 operates using the electric power of the battery pack 20 attached to the battery attachment section 21 as a power source.

[0030] A slide-mounted battery pack 20 is attached to the battery attachment section 21. As shown in FIG. 11 , the battery attachment section 21 is provided with a pair of left and right rail sections 21a, 21b. The left and right rail sections 21a, 21b extend vertically. A positive terminal 21c and a negative terminal 21d are arranged vertically extending vertically between the left and right rail sections 21a, 21b. A control terminal 21e for a control signal is arranged between the positive terminal 21c and the negative terminal 21d. A claw engagement section 21f is provided at the top of the battery attachment section 21. The attachment state of the battery pack 20 to the battery attachment section 21 is locked by engaging the lock claw of the battery pack 20 with the claw engagement section 21f.

[0031] As shown in Figures 1, 2, and 6, a single push button 20a is provided on the top of the battery pack 20. When the push button 20a is pressed, the locking claw is disengaged from the claw engagement portion 21f. This releases the installation lock state, allowing the battery pack 20 to slide upward. A remaining capacity display portion 20b is provided on the top surface of the battery pack 20.

[0032] 10 , the battery pack 20 is mechanically attached to the battery mounting portion 21 by sliding the battery pack 20 downward while engaging the rail receiving portions of the battery pack 20 along the left and right rail portions 21a, 21b. When mechanically attached to the battery mounting portion 21, the battery pack 20 is electrically connected to the battery mounting portion 21. Conversely, the battery pack 20 can be removed from the battery mounting portion 21 by sliding the battery pack 20 upward while pressing the push button 20a.

[0033] The main body housing 13 is provided with a handle 17 and a front grip 18 for the user to grasp. As shown in Figures 1, 2, 4, and 9, the handle 17 has a vertical loop shape that extends from the top to the rear of the main body housing 13. The grip portion 17a of the handle 17 is positioned in a forward-leaning position, with the upper side tilting forward. The outer surface of the handle 17 is coated with an elastomer resin layer, which prevents the grip portion 17a from slipping and ensures a good grip.

[0034] A trigger 17b is provided on the upper inner periphery of the handle 17. A switch body (not visible in the figure) is installed behind the trigger 17b. When the trigger 17b is pulled with the fingertips of the hand holding the grip portion 17a, the electric motor 11 starts and the cutting tool 12 rotates. Lock-off buttons 17c are located above the trigger 17b, on both sides of the upper part of the handle 17. The trigger 17b can be pulled by pressing the lock-off button 17c. The trigger 17b cannot be pulled without pressing the lock-off button 17c. This locks the electric motor 11 in a stopped state.

[0035] As shown in Figures 5 and 6, the front grip 18 has a loop shape extending in the left-right direction from the front of the main body housing 13 to the rear of the motor housing 14. The grip portion 18a of the front grip 18 extends in the left-right direction, approximately perpendicular to the cutting direction. For example, a user can hold the grip portion 17a of the handle 17 with their right hand and the grip portion 18a of the front grip 18 with their left hand. This allows the portable cutting machine 1 to be moved and operated in the cutting direction in a stable position.

[0036] As shown in Figures 8 and 9, a light 19 is provided at the front of the main body housing 13. At the front of the main body housing 13, below the front grip 18, an arm 19a is provided so as to protrude forward. The light 19 is installed at the tip of the arm 19a. The light 19 brightly illuminates the cutting area C (the cutting edge of the cutting tool 12). This makes it easy to perform cutting work in dark places, for example.

[0037] One dust case 30 is attached to the right side of the main body housing 13. The dust case 30 is attached along the fixed cover portion 13a. As shown in FIG. 7, the fixed cover portion 13a is provided with a magnesium die-cast dust collection wall portion 13b that shields the right side of the cutting tool 12. The dust collection wall portion 13b is provided in an arc shape along the side of the upper half of the cutting tool 12. An arrow 13c indicating the rotation direction of the cutting tool 12 is marked on the dust collection wall portion 13b. The dust case 13 consists of a dust collection portion 31 where dust accumulates and a ventilation portion 32 facing the outer surface. The dust collection portion 31 is made of magnesium die-cast, and the ventilation portion 32 is made of synthetic resin.

[0038] During the cutting process, cutting dust is blown up from the cut area C. The cutting dust is blown up toward the inside (left side) of the dust collection wall portion 13b. The blown up cutting dust is carried by the current of air generated by the rotation of the cutting tool 12 and flows counterclockwise in the figure. The upper part of the dust collection wall portion 13b is cut away. This leaves two openings 13d and 13e at the top of the fixed cover portion 13a. The openings 13d and 13e are separated by a shielding wall 13f. The cutting dust flows into the dust case 30 through the front opening 13d. The motor cooling air flows into the dust case 30 through the rear opening 13e.

[0039] 3 and 13, the dust case 30 has a generally semicircular box body. The interior of the dust case 30 is divided into a dust collection section 31 and a ventilation section 32 by a partition wall section 33. Two openings 30a and 30b are provided at the upper part of the inner surface of the dust case 30. The openings 30a and 30b are divided by the partition wall section 33. The front opening 30a is connected to the dust collection section 31. The rear opening 30b is connected to the ventilation section 32. When the dust case 30 is attached along the fixed cover section 13a, the front opening 30a is connected to the opening 13d of the fixed cover section 13a, and the rear opening 30b is connected to the opening 13e of the fixed cover section 13a.

[0040] The cutting dust flowing along the dust collection wall 13b due to the rotating wind of the cutting tool 12 flows into the dust collection unit 31 through the openings 13d and 30a. The cutting dust collected in the dust collection unit 31 is discarded from the opening 30a by removing the dust case 30 from the fixed cover unit 13a. For example, a separate opening / closing lid may be provided at the rear of the dust collection unit 31 for disposal.

[0041] The motor cooling air flows into the ventilation section 32 through the openings 13e and 30b. The motor cooling air Z that flows into the ventilation section 32 cools the cutting dust collected in the dust collection section 31 through the partition section 33. Exhaust ports 30c are provided at the bottom of the ventilation section 32. The exhaust ports 30c are provided at the front, side, and rear of the dust case 30. The motor cooling air Z that has cooled the cutting dust is exhausted to the outside from the multiple exhaust ports 30c.

[0042] The dust case 30 has an attachment / detachment operation unit 35 that is operated when removing the dust case 30 from the cutting machine body 10, and a finger support unit 40 that is contacted by a fingertip. The attachment / detachment operation unit 35 is located at the rear of the dust case 30. The finger support unit 40 is located approximately in the center of the right side of the dust case 30. As shown in FIG. 12, the attachment / detachment operation unit 35 has a rectangular, flat push operation unit 36. As shown in FIGS. 4 and 12, the push operation unit 36 ​​is pushed with a single fingertip F1 (e.g., a thumb). The push operation unit 36 ​​is pushed along an imaginary plane K that is parallel to the surface of the cutting tool 12. In this embodiment, the push operation unit 36 ​​is pushed diagonally downward and forward. In FIGS. 4 and 12, the pushing direction of the push operation unit 36 ​​is indicated by arrow D. In this embodiment, the push operation unit 36 ​​rotates around a support shaft 36e (see FIG. 14) that is provided in an axial direction perpendicular to an imaginary operation line L in a side view perpendicular to the cutting tool 12. Therefore, strictly speaking, the push operation direction D changes slightly with the operation, but since the change in direction is slight, it will be referred to as "push operation direction D" below without any special annotation.

[0043] As shown in Figure 12, the pushing operation portion 36 is biased in the direction opposite to the pushing operation by a compression spring 37. The pushing operation portion 36 is pushed in the pushing operation direction D against the compression spring 37. The pushing operation portion 36 is provided with an engagement arm 36a as a first engagement portion. The engagement arm 36a protrudes to the left. An engagement claw 36b is provided at the tip of the engagement arm 36a.

[0044] As shown in Figures 2, 7, and 12, a rectangular engagement window 13g is provided at the rear of the dust collection wall portion 13b. The engagement claw 36b is hooked onto the upper edge of the engagement window 13g, thereby connecting the rear side of the dust case 30 to the cutting machine body 10 as shown in Figures 1 and 5. When the pushing operation unit 36 ​​is pushed in the pushing operation direction D, the engagement claw 36b disengages from the engagement window 13g. By displacing the rear side of the dust case 30 to the right in this state, the engagement arm 36a is removed from the engagement window 13g. As a result, the rear side of the dust case 30 is detached from the cutting machine body 10 as shown in Figures 2 and 6.

[0045] 12, the upper surface of the pushing operation part 36 has a concave shape that deepens toward the cutting tool 12. A plurality of protrusions 36c extending up and down are provided on the upper surface of the pushing operation part 36, aligned on the left and right (direction in which the depth changes). This makes it easier to apply force to the pushing operation part 36 in the removal direction (to the right) to the fingertip F1.

[0046] An inclined surface 36d is provided on the left side of the engagement claw 36b. When the dust case 30 is attached, the inclined surface 36d abuts against the upper part of the engagement window 13g, pushing down the engagement arm 36a. This causes the pushing operation unit 36 ​​to be pushed down against the compression spring 37. Therefore, when the dust case 30 is attached, the engagement arm 36a engages with the engagement window 13g without the need to press the pushing operation unit 36 ​​with the fingertip F1, and the rear side of the dust case 30 is connected to the cutting machine body 10.

[0047] As shown in FIG. 4 , a finger support portion 40 is provided in front of the attachment / detachment operating portion 35 in the pushing operation direction D. A stepped portion 38 is provided on the right side of the dust case 30. The stepped portion 38 is provided along an operation imaginary line L (an imaginary line extending in the pushing operation direction D) in an area from near the attachment / detachment operating portion 35 to near the center of the right side. The stepped portion 38 has a trapezoidal shape in side view and a trapezoidal cross section whose vertical width increases diagonally downward and forward. The front end of the stepped portion 38 forms a wall surface perpendicular to the surface direction of the cutting tool 12. The wall surface of the front end forms the finger support portion 40. When attaching or detaching the dust case 30, one fingertip F2 (e.g., the middle finger) abuts on the finger support portion 40. Two fingertips (e.g., the index finger and the middle finger) may also abut on the finger support portion 40.

[0048] The finger support portion 40 extends in a direction perpendicular to the virtual operation line L. In this embodiment, the finger support portion 40 is provided at a position 110 mm forward from the attachment / detachment operation portion 35 along the virtual operation line L. The distance (110 mm) from the attachment / detachment operation portion 35 to the finger support portion 40 can be changed within a range of ±10 mm. The distance (110 mm) from the attachment / detachment operation portion 35 to the finger support portion 40 is set within a range of ±20% of the radius of the cutting tool 12. Since the diameter of the cutting tool 12 is 185 mm, the radius is 92.5 mm. This is set by the calculation: 92.5 mm + 92.5 mm × 19% = 110 mm. The distance from the attachment / detachment operation portion 35 to the finger support portion 40 can be changed within a range of ±20% of the radius of the cutting tool 12.

[0049] The finger support portion 40 is formed on a flat end surface that is 50 mm long in a direction perpendicular to the operation imaginary line L in a side view perpendicular to the cutting tool 12 and 20 mm wide in a direction perpendicular to the surface of the cutting tool 12. The finger support portion 40 has a length of 50 mm ± 10 mm in a direction perpendicular to the operation imaginary line L in a side view perpendicular to the cutting tool 12, and the width can be changed within a range of 20 mm ± 5 mm in the direction perpendicular to the surface of the cutting tool 12.

[0050] A vertical wall portion 41 is provided on the upper portion of the finger support portion 40 so as to protrude in a direction perpendicular to the surface of the cutting tool 12. The vertical wall portion 41 prevents the fingertip F2 from shifting upward. The dust case 30 can be held by pinching the step portion 38 between the fingertip F1 abutting on the attachment / detachment operation portion 35 and the fingertip F2 abutting on the finger support portion 40. This allows the dust case 30 to be held between the two fingertips F1 and F2 to be attached or detached.

[0051] As shown in Fig. 3, a single engagement recess 45 is provided as a second engagement portion at the front portion of the inner surface (left side) of the dust case 30. As shown in Fig. 7, an engagement protrusion 13h is provided at the front portion of the fixed cover portion 13a. As shown in Fig. 15, the engagement recess 45 is inserted below the fixed cover portion 13a so that the engagement protrusion 13h enters the engagement recess 45, thereby connecting the front portion of the dust case 30 to the cutting machine body 10. Thereafter, the engagement arm 36a of the attachment / detachment operation portion 35 is pushed into the engagement window 13g, thereby connecting the rear portion of the dust case 30 to the cutting machine body 10.

[0052] As shown in FIG. 8 , marks 42 and 43 are provided on the front surface of the fixed cover portion 13a and the front surface of the dust case 30, respectively. The marks 42 and 43 are recesses shaped like the letter "H" rotated 90 degrees horizontally. The mark 42 on the fixed cover portion 13a is displayed to match the vertical size (actual size) and position of the engaging protrusion 13h. The mark 43 on the dust case 30 is also displayed to match the vertical size (actual size) and position of the engaging protrusion 13h. When the front side of the dust case 30 is inserted below the fixed cover portion 13a so that the marks 42 and 43 are aligned vertically, the engaging protrusion 13h enters the engaging recess 45. This allows for efficient and quick coupling of the front side of the dust case 30 to the cutting machine body 10. In this embodiment, the marks 42 and 43 are displayed as recesses. Therefore, the user can recognize the marks 42 and 43 by touch, without having to look into the front side to visually identify them. This makes it easier to install the dust case 30.

[0053] As shown in FIG. 3, the engaging recess 45 as the second engaging portion is provided at a position offset upward from the virtual operation line L.

[0054] An arrow 44 indicating the rotation direction of the cutting tool 12 is also displayed on the right side of the dust case 30 .

[0055] The portable cutting machine 1 has a depth adjustment mechanism 28 for adjusting the cutting depth. As shown in Figures 5, 6, and 10, a fixing screw 28b is fastened to the left side of the main body housing 13. The fixing screw 28b is inserted into an insertion groove of an arc-shaped depth guide 28a. The depth guide 28a is supported on the top surface of the base 2 so that it can tilt back and forth. A lever 28c is connected to the fixing screw 28b. By rotating the lever 28c up and down, the fixing screw 28b rotates in the tightening or loosening direction.

[0056] By loosening the fixing screw 28b, the cutting machine body 10 can be rotated up and down around the support shaft 3. This changes the projection dimension of the cutting tool 12 toward the underside 2a of the base 2 (the cutting depth into the workpiece W). By rotating the lever 28c, for example, downward, the fixing screw 28b is tightened into the body housing 13. This fixes the relative position of the depth guide 28a with respect to the cutting machine body 10, and fixes the vertical position of the cutting machine body 10 with respect to the base 2. This fixes the cutting depth of the cutting tool 12.

[0057] When the cutting machine body 10 is adjusted to the top dead center as shown in Fig. 14, the cutting depth of the cutting tool 12 is minimum. When the cutting machine body 10 is adjusted to the bottom dead center as shown in Fig. 4, the cutting depth of the cutting tool 12 is maximum. When the cutting machine body 10 is adjusted to the bottom dead center, an imaginary operation line L extending along the pushing direction D of the attachment / detachment operation part 35 is inclined at approximately 30° with respect to the underside 2a of the base 2. The inclination angle α of the imaginary operation line L (pushing direction D) can be changed within a range of 20° to 40°.

[0058] As shown in FIG. 4 , the area center (geometric center) G of the dust case 30 in a side view perpendicular to the cutting tool 12 is located within the area surrounded by the attachment / detachment operation part 35 and the finger support part 40. The relative position of the finger support part 40 with respect to the attachment / detachment operation part 35 is appropriately set so that the area center G is located between the attachment / detachment operation part 35 and the finger support part 40. Although the area center G changes depending on the amount of cutting dust collected in the dust collection part 31 of the dust case 30, it can be considered to be roughly the center of gravity of the dust case 30. Therefore, by locating the area center G between the attachment / detachment operation part 35 and the finger support part 40, the gripping of the dust case 30 with the two fingertips F1, F2 is further improved in terms of weight balance.

[0059] The attachment / detachment operation unit 35 and the finger support unit 40 are arranged on an imaginary operation line L. The imaginary operation line L crosses the grip portion 17a of the handle 17, which is located behind the attachment / detachment operation unit 35 in a side view. The attachment / detachment operation unit 35, the finger support unit 40, and the grip portion 17a are located on one imaginary operation line L. As a result, when attaching or detaching the dust case 30 while holding the grip portion 17a with, for example, the left hand, the thumb F1 and middle finger F2 of the right hand can be placed in a comfortable position against the attachment / detachment operation unit 35 and the finger support unit 40. This further improves the operability of attaching and detaching the dust case 30.

[0060] According to the embodiment described above, the portable cutting machine 1 includes a dust case 30 that is detachable from the cutting machine body 10. The dust case 30 has an attachment / detachment operation unit 35 that is pushed on an imaginary plane K parallel to the surface of the cutting tool 12 when the dust case 30 is removed from the cutting machine body 10, and a finger support unit 40 that includes a surface that is substantially perpendicular to the pushing operation direction D and is located in front of the pushing operation direction D of the attachment / detachment operation unit 35.

[0061] Therefore, the dust case 30 can be removed by pinching the attachment / detachment operation part 35 and the finger support part 40 between two fingertips F1, F2. This improves the operability of attaching and detaching the dust case 30. In particular, because the finger support part 40 is located in front of the attachment / detachment operation part 35 in the pushing operation direction D, the pushing operation part 36 can be pinched between the finger support part 40 and the pushing operation part 36, and then pressed. In this respect, the operability of removal is particularly improved.

[0062] According to the embodiment, the center G of the area of ​​the dust case 30 in a side view perpendicular to the cutting tool 12 is located between the attachment / detachment operation unit 35 and the finger support unit 40. This makes it easier to grip the dust case 30. In particular, since the center of gravity is located near the center G of the area in a side view, the dust case 30 can be gripped with good weight balance in a horizontal position with the side facing upward, for example.

[0063] According to the embodiment, the portable cutting machine 1 has a depth adjustment mechanism 28 that adjusts the position of the cutting machine body 10 between the top dead center and the bottom dead center with respect to the base 2. When the cutting machine body 10 is located at the bottom dead center, an imaginary operation line L extending in the pushing direction D of the attachment / detachment operation unit 35 is inclined at an angle of approximately 30° with respect to the underside 2a of the base 2. This makes it easier for the user to apply a pushing force to the pushing operation unit 36 ​​of the attachment / detachment operation unit 35.

[0064] According to the embodiment, the portable cutting machine 1 has an engagement arm 36a as a first engagement portion for engaging the dust case 30 with the cutting machine body 10, and an engagement recess 45 as a second engagement portion. The engagement arm 36a is provided on the attachment / detachment operation portion 35. The engagement recess 45 is provided at a position above and away from the imaginary operation line L in a side view perpendicular to the cutting tool 12. This makes it easier for the user to see the engagement recess 45 from diagonally above and behind, improving operability when attaching and detaching the dust case 30.

[0065] According to the embodiment, the length M from the attachment / detachment operation part 35 to the finger support part 40 is set to ±20% of the radius of the cutting tool 12 or 110 mm ±10 mm. This makes it easier to grip the dust case 30. The length M from the attachment / detachment operation part 35 to the finger support part 40 can be changed within ±20% of the radius of the cutting tool 12 or in the range of 100 mm to 120 mm.

[0066] According to the embodiment, the attachment / detachment operation unit 35 has a push operation unit 36 ​​that has a concave shape that is concave in the push operation direction D. This makes it easier to apply a push operation force to the push operation unit 36 ​​in the push operation direction D. The concave shape allows the push operation unit 36 ​​to be confirmed by the feel of the fingertip F1, thereby improving the operability of the push operation unit 36.

[0067] According to the embodiment, the upper surface of the pushing operation unit 36 ​​has a concave shape that deepens toward the cutting tool 12. This makes it easier to efficiently apply a pushing force to the pushing operation unit 36 ​​in the removal direction when the pushing operation unit 36 ​​is disposed above the cutting tool 12.

[0068] According to the embodiment, the finger support portion 40 is provided in a flat surface shape with a length of 50 mm±10 mm in a side view perpendicular to the cutting tool 12 and a length of 20 mm±5 mm in a direction perpendicular to the surface of the cutting tool 12. This allows the fingertip F2 to be securely pressed against the finger support portion 40 to grip the dust case 30.

[0069] In the embodiment, a vertical wall portion 41 that protrudes in a direction perpendicular to the surface of the cutting tool 12 is provided on the upper portion of the finger support portion 40. This prevents the fingertip F2 from slipping on the finger support portion 40, improving the grip of the finger support portion 40.

[0070] According to this embodiment, the virtual operation line L of the attachment / detachment operation unit 35 passes through the grip portion 17a of the handle 17. This improves operability when attaching or detaching the dust case 30 with the right hand while holding the grip portion 17a with the left hand, for example.

[0071] According to the embodiment, a mark 43 indicating the position of an engaging recess 45 serving as a second engaging portion is provided on the front surface of the dust case 30. A mark 42 is provided on the front surface of the fixed cover portion 13a. By aligning the mark 43 with the mark 42, the user can quickly insert the engaging protrusion 13h into the engaging recess 45. This facilitates installation of the dust case 30.

[0072] The above-described embodiment can be modified in various ways. For example, the vertical wall portion 41 may be omitted. Furthermore, the relationship between the recessed engaging portion 45 as the second engaging portion and the protruding engaging portion 13h on the cutting machine body 10 may be reversed.

[0073] The user can freely change which fingertips are placed on the attachment / detachment operation unit 35 and the finger support unit 40. For example, the user can attach or detach the dust case by placing the middle finger F2 on the attachment / detachment operation unit 35 and the thumb F1 on the finger support unit 40.

[0074] Although the finger support portion 40 is illustrated as having a flat wall surface in a direction perpendicular to the operation imaginary line L, it may also have a curved surface that is gently recessed toward the attachment / detachment operation portion 35. This prevents the fingers from shifting position and improves gripping ability.

[0075] Although a so-called tip saw cutter has been exemplified as the portable cutting machine 1, the detachable operation unit 35 and finger support unit 40 can also be applied to a portable circular saw equipped with a dust case (dust box) such as a dustproof circular saw. Regarding the structure of the dust case, a type with an opening at the top that is always open has been exemplified, but the present invention can also be applied to a dust box that does not have an opening at the top.

[0076] The portable cutting machine 1 of the embodiment is an example of a portable cutting machine in the present disclosure. The cutting tool 12 of the embodiment is an example of a cutting tool of the present disclosure. The cutting machine body 10 of the embodiment is an example of a cutting machine body of the present disclosure. The dust case 30 of the embodiment is an example of a dust case of the present disclosure. The imaginary plane K of the embodiment is an example of an imaginary plane of the present disclosure. The attachment / detachment operation unit 35 of the embodiment is an example of an attachment / detachment operation unit of the present disclosure. The pushing operation direction D of the embodiment is an example of a pushing operation direction of the present disclosure. The finger support unit 40 of the embodiment is an example of a finger support unit of the present disclosure. [Explanation of symbols]

[0077] 1. Portable cutting machine 2...Bass 2a…Bottom surface 3…Spindle 10…Cutting machine body 11...Electric motor 11a... stator, 11b... motor shaft, 11c... cooling fan, 11d... rotor 12...Cutter 12a...outer flange, 12b...inner flange 13...Main body housing 13a...fixed cover portion, 13b...dust collection wall portion, 13c...arrow (rotation direction of cutting tool 12) 13d...opening (cutting powder), 13e...opening (motor cooling air), 13f...shielding wall, 13g...engagement window 14...Motor housing 14a...Air intake Z…Cooling air 15...Controller 15a...case, 15b...control board, 15c...resin mold 16...Reduction gear train 16a...Spindle 17...Handle 17a...gripping portion, 17b...trigger, 17c...lock-off button 18...Front grip 18a...gripping part 19...Lighting 19a...Arm section C... Cutting site 20...Battery pack 20a... push button, 20b... remaining capacity display section 21...Battery mounting section 21a, 21b... Rail portion, 21c... Positive terminal, 21d... Negative terminal, 21e... Control terminal 21f...claw engagement part 25... Movable cover 26...Spindle lock lever 28...Depth adjustment mechanism 28a...Depth guide, 28b...Fixing screw, 28c...Lever 30...Dust case 30a...opening (cutting dust), 30b...opening (motor cooling air), 30c...exhaust port 31...Dust collection section 32...Ventilation section 33...Partition wall 35...Attachment / detachment operation section 36...Push operation part 36a...engagement arm (first engagement portion), 36b...engagement claw, 36c...protrusion, 36d...inclined surface 36e…Spindle part 37...Compression spring 38...Step 40...Finger support part F1...Fingertip (thumb) F2…Fingertip (middle finger) D: Push operation direction K...Virtual plane L... Virtual operation line G…Area center (geometric center) M: Length from the attachment / detachment operation part 35 to the finger support part 40 41...Vertical wall part 42...Mark (engagement protrusion 13h) 43...Mark (engagement protrusion 13h) 44...Arrow (rotation direction of cutting tool 12) 45...Engagement recess (second engagement portion)

Claims

1. A portable cutting machine, a cutting machine body to which a circular cutting tool is attached; The cutting machine body is provided with a detachable dust case, the dust case has an attachment / detachment operation part that is pushed on an imaginary plane parallel to a surface of the cutting tool when the dust case is removed from the cutting machine body, and a finger support part that includes a surface that is located in front of the pushing direction of the attachment / detachment operation part and is substantially perpendicular to the pushing direction, the attachment / detachment operation unit has a pressing operation unit that is contacted by a fingertip, The pushing operation unit is supported rotatably about a support shaft arranged perpendicular to the pushing operation direction on the side away from the cutting tool in a direction perpendicular to the surface of the cutting tool.

2. 2. The portable cutting machine of claim 1, The portable cutting machine has an area center of the dust case located between the attachment / detachment operation unit and the finger support unit when viewed from the side perpendicular to the cutting tool.

3. The portable cutting machine according to claim 1 or 2, a base having a lower surface that contacts the workpiece; a depth adjustment mechanism for adjusting the position of the cutting machine body relative to the base between a top dead center and a bottom dead center; When the cutting machine body is positioned at the bottom dead center, an imaginary operation line extending in the pushing operation direction of the attachment / detachment operation part is inclined at an angle of 20° to 40° with respect to the underside of the base.

4. The portable cutting machine according to any one of claims 1 to 3, a first engaging portion and a second engaging portion for engaging the dust case with the cutting machine body; the first engagement portion is provided on the attachment / detachment operation portion, The portable cutting machine is configured such that the second engagement portion is located at a position that is off an imaginary operation line that extends in the pushing operation direction of the attachment / detachment operation portion in a side view that is perpendicular to the cutting tool.

5. The portable cutting machine according to any one of claims 1 to 4, A portable cutting machine in which the length from the attachment / detachment operation unit to the finger support unit is ±20% of the radius of the cutting tool.

6. 6. The portable cutting machine according to claim 5, A portable cutting machine in which the length from the attachment / detachment operation unit to the finger support unit is 110 mm±10 mm.

7. The portable cutting machine according to any one of claims 1 to 6, The detachable operation unit has a push operation portion having a concave shape that is concave in the pushing operation direction.

8. 8. The portable cutting machine of claim 7, The push operation portion has a concave shape that becomes deeper toward the cutting tool side.

9. A portable cutting machine according to any one of claims 1 to 8, The finger support portion has a length of 50 mm±10 mm in a side view perpendicular to the cutting tool, and a width of 20 mm±5 mm in a direction perpendicular to the surface of the cutting tool.

10. A portable cutting machine according to any one of claims 1 to 9, The portable cutting machine has a vertical wall portion on the upper part of the finger support portion that protrudes in a direction perpendicular to the surface of the cutting tool.

11. A portable cutting machine according to any one of claims 1 to 10, The cutting machine body has a handle portion, A portable cutting machine in which an imaginary operation line extending in the pushing direction of the attachment / detachment operation part passes through the grip part of the handle part.

12. A portable cutting machine according to any one of claims 1 to 11, a first engaging portion and a second engaging portion for engaging the dust case with the cutting machine body; the first engagement portion is provided at a rear portion of the dust case in the cutting direction, the second engagement portion is provided at a front portion of the dust case in the cutting direction, A portable cutting machine in which a mark indicating the position of the second engagement portion is provided on the front surface of the dust case.

Images