Portable cutter for metalworking

Abstract

To improve heat radiation performance of a lid to improve operability when the lid is opened or closed in a portable cutter for metalworking referred to as a chip saw cutter, which has a dust collection box for collecting chips, is configured to discard the chips through a discharge port opened by opening the lid, and has an issue that the lid may be heated by highly-heated chips, demanding attention during opening / closing operation.SOLUTION: A heat radiation part 55 is provided at a part of a surface of a lid 50 which opens or closes a discharge port of a dust collection box 40. The heat radiation part 55 has multiple projections 55a. The structure increases a surface area of the lid 50 to improve heat radiation performance. The heat radiation part 55 makes the lid 50 less likely to be heated to improve operability when the lid 50 is opened or closed.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a portable metalworking cutting machine that an operator holds in his / her hand, moves and operates to cut metal. [Background technology]

[0002] For example, a portable cutting machine for metalworking that uses a metal-tipped saw, known as a tipped saw cutter, is equipped with a dust collection box for collecting sparks generated during cutting and high-temperature chips generated when the temperature of the sparks drops. As disclosed in Patent Document 1, the rear of the dust collection box has an outlet for disposing of the collected chips. The outlet is opened and closed with a lid. The user can open the lid and dispose of the chips collected in the dust collection box through the outlet. A tipped saw is a type of cutting blade in which the tip and base are manufactured as separate parts and then integrated by welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-198912 Summary of the Invention [Problem to be solved by the invention]

[0004] The dust collection box lid can become very hot due to the chips collected in it, so care must be taken when opening and closing the lid. For this reason, it is necessary to improve the operability of the lid. The present disclosure aims to improve the operability of the discharge port lid for the dust collection box of a portable metalworking cutting machine. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a portable metalworking cutter includes, for example, a cutter body having a cutting blade and a dust collection box for collecting chips generated by cutting. The dust collection box includes, for example, an outlet for discharging the chips and a lid for opening and closing the outlet. For example, the lid has a heat dissipation portion on a portion of its surface.

[0006] Therefore, the heat from the lid is efficiently dissipated by the heat dissipation portion, which makes the lid less likely to heat up and improves operability when opening and closing.

[0007] According to another aspect of the present disclosure, a portable metalworking cutter includes, for example, a cutter body having a cutting blade and a dust collection box for collecting chips generated by cutting. The box body of the dust collection box is composed of, for example, a first body portion made of a first synthetic resin with a metal plate integrated on its inner surface, and a second body portion made of a second synthetic resin that has higher heat resistance than the first synthetic resin.

[0008] Therefore, by disposing metal only in the first main body portion, the weight of the dust collection box can be reduced, and the heat resistance of the dust collection box can be improved by the second main body portion. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a right side view of the portable metalworking cutting machine according to the present embodiment. [Figure 2] FIG. 2 is a view taken along the arrow II in FIG. 1 and is a plan view of the portable metalworking cutting machine. [Figure 3] FIG. 3 is a view taken along the arrow III in FIG. 1, showing a front view of the portable metalworking cutting machine. [Figure 4] 4 is a view taken along the line IV in FIG. 1, showing a rear view of the portable metalworking cutting machine. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 1 is a right side view of a portable metalworking cutting machine with the dust collection box removed. [Figure 8]This is a perspective view of the dust collection box, as seen from the front right. [Figure 9] This is a perspective view of the dust collection box, as seen from the right rear with the lid closed. [Figure 10] This is a perspective view of the dust collection box, as seen from the rear right with the lid open. [Figure 11] 1 is a perspective view of the first main body portion, as seen from the inside of the box body, and as seen from diagonally rear left. [Figure 12] 10 is a perspective view of the second main body portion, as seen from the inside of the box main body, and as seen from the right rear. [Figure 13] This is a vertical cross-sectional view of the dust collection box, showing the state in which the lid is closed. [Figure 14] FIG. [Figure 15] 15 is a cross-sectional view taken along the line XV-XV in FIG. 14, and is a vertical cross-sectional view of the lid. DETAILED DESCRIPTION OF THE INVENTION

[0010] In one or more embodiments, for example, the heat dissipation portion includes a plurality of ridges, which increase the surface area of ​​the lid and allow for efficient heat dissipation.

[0011] In one or more embodiments, for example, the ridges are arranged parallel to one another, allowing outside air to easily flow between the ridges, thereby improving heat dissipation.

[0012] In one or more embodiments, for example, the lid is rotatably connected to the box body of the dust collection box. The plurality of ridges extend, for example, perpendicular to the rotation direction of the lid. The lid has, for example, a wall portion connecting the ends of the plurality of ridges. Therefore, the support rigidity of the plurality of ridges is increased.

[0013] In one or more embodiments, for example, the lid has a hinge portion rotatably connected to the box body of the dust collection box, an arm portion extending in a bending direction from an end of the hinge portion, and a recess recessed from the arm portion toward the hinge portion. Therefore, the arm portion is less likely to bend, thereby increasing the rigidity of the lid without increasing its size. Furthermore, the recess increases the surface area of ​​the arm portion, thereby improving heat dissipation.

[0014] In one or more embodiments, for example, the recess is recessed into the outlet when the lid is in the closed position, thereby providing compactness when the lid is in the closed position.

[0015] In one or more embodiments, for example, the recess has an annular wall extending from the arm toward the hinge and a bottom covering the end of the wall. For example, the heat dissipation portion has multiple ridges protruding from the bottom toward the arm. Therefore, the multiple ridges are arranged within the recess, making the heat dissipation portion more compact.

[0016] In one or more embodiments, for example, the lid has an engagement piece that extends from the end of the arm in a direction bending toward the hinge. For example, the engagement piece has an engagement hole that engages with an engagement portion provided on the dust collection box. Therefore, the engagement portion engages with the engagement hole of the engagement piece, thereby holding the lid in the closed position. Furthermore, the hinge, arm, and engagement piece are arranged in a curved shape, improving operability when opening and closing.

[0017] In one or more embodiments, for example, the dust collection box has a metal ventilation plate with multiple ventilation holes formed therein, and the engagement hole faces the ventilation plate, thereby ensuring ventilation through the ventilation holes when the lid is closed.

[0018] In one or more embodiments, for example, the lid has a knob extending from the end of the engagement piece in a direction away from the box body, which improves operability when opening and closing the lid.

[0019] In one or more embodiments, for example, the box body of the dust collection box includes a first body portion made of a first synthetic resin integrated with a metal, and a second body portion made of a second synthetic resin that has higher heat resistance than the first synthetic resin. Therefore, the dust collection box is made lighter by disposing metal only in the first body portion, and the heat resistance of the dust collection box is improved by the second body portion.

[0020] In one or more embodiments, for example, the first synthetic resin of the first body portion is translucent, thereby ensuring visibility of the amount of collected chips.

[0021] In one or more embodiments, the box body has a first body portion on one side of the cutting blade in the thickness direction and a second body portion on the other side. For example, the width of the second body portion in the thickness direction is greater than the width of the first body portion in the thickness direction. This ensures high heat resistance of the dust collection box.

[0022] In one or more embodiments, for example, the second body portion is formed from a material that includes polyamide as the second synthetic resin and glass fiber, thereby ensuring high heat resistance of the second body portion. [Example]

[0023] As shown in Figures 1 to 4, the portable metalworking cutting machine 1 according to this embodiment is a portable metalworking cutting machine that uses a metal-tipped saw, also known as a tipped saw cutter, and includes a base 10 that contacts the top surface of the workpiece 2 to be cut, and a cutting machine body 20 supported on the top surface of the base 10. The base 10 has a rectangular flat plate shape, and its underside contacts the top surface of the workpiece 2 to be cut. In Figures 1 and 2, the user is positioned on the left side of the portable metalworking cutting machine 1 and operates it to move rightward, thereby progressing the cutting process. In the following description, the cutting direction is the front side, and the user side is the rear side. The left and right directions are based on the user.

[0024] As shown in Figures 5 to 7, the cutting machine body 20 includes an electric motor 21 as a drive source and a disk-shaped cutting blade 30 that is rotated by the electric motor 21. A brushless motor that is high-power and compact in the direction of the motor shaft is used for the electric motor 21. The rotational output of the electric motor 21 is output to an output shaft 23 via a reduction gear unit 22. A gear housing 25 is connected to the right end of the motor housing 24.

[0025] A loop-shaped handle 26 is provided above the joint between the motor housing 24 and the gear housing 25. A switch lever 27 is provided on the inner periphery of the handle 26. The electric motor 21 is started by turning on the switch lever 27 with the fingertips of the hand holding the handle 26.

[0026] A battery mounting section 28 is provided at the rear of the handle 26. One battery pack 11 is attached to the battery mounting section 28. A slide-on / off lithium-ion battery is used for the battery pack 11. The electric motor 21 is started using the power of the battery pack 11 attached to the battery mounting section 28. The battery pack 11 can be removed from the battery mounting section 28 and charged with a separately provided charger, allowing it to be used repeatedly.

[0027] As shown in Figures 5 to 7, a fixed cover 35 made of transparent resin is attached to the flange portion 25a at the right end of the gear housing 25. The fixed cover 35 is made of polycarbonate. The fixed cover 35 is attached to the gear housing 25 with two fixing screws 35d. The fixed cover 35 and the flange portion 25a of the gear housing 25 are joined to each other to form a cover member. The output shaft 23 protrudes into the fixed cover 35. A cutting blade 30 is attached to the output shaft 23. The cutting blade 30 is sandwiched between an outer flange 31 and an inner flange 32 in the plate thickness direction and fixed to the output shaft 23 by tightening the fixing screws 33. A circular saw blade for cutting metal materials, also known as a tipped saw blade, is used as the cutting blade 30.

[0028] Approximately half the upper circumference of the cutting blade 30 (the range on the upper surface of the base 10) is covered by the fixed cover 35 and the flange portion 25a of the gear housing 25. When the cutting blade 30 cuts into the workpiece 2, chips are generated at the cutting area 3. The chips are blown upward by the rotation of the cutting blade 30. A square cylindrical dust collection duct portion 35b is provided at the front of the fixed cover 35. The dust collection duct portion 35b is positioned above the cutting area 3. A steel metal plate 35c is provided on the front side of the inner surface of the dust collection duct portion 35b. The metal plate 35c protects the fixed cover 35 from collisions with high-temperature chips. As a result, the chips blown upward from the cutting area 3 flow into the dust collection box 40 via the dust collection duct portion 35b.

[0029] An arrow 35 a indicating the direction of rotation of the cutting blade 30 is displayed on the right side of the fixed cover 35 .

[0030] A movable cover 36 covers approximately half the lower circumference of the cutting blade 30 (the range on the underside of the base 10). The movable cover 36 is rotatably supported on the right side of the gear housing 25. Rotation of the movable cover 36 opens and closes the cutting edge of the cutting blade 30 on the underside of the base 10. The movable cover 36 is biased in the closing direction. As the cutting process progresses by moving the portable metalworking cutter 1, the movable cover 36, which is in contact with the workpiece 2, gradually opens against the biasing force.

[0031] The cutting machine body 20 is supported on the upper surface of the base 10 via a swing support part 37. The cutting machine body 20 is supported by the swing support part 37 so that it can swing up and down. By changing the swing position of the cutting machine body 20 up and down, the cutting depth of the cutting blade 30 into the workpiece 2 can be adjusted.

[0032] A dust collection box 40 for collecting chips that have flowed inside the fixed cover 35 is removably attached to the right side of the fixed cover 35. Figures 8 to 10 show the dust collection box 40 removed from the right side of the fixed cover 35. The dust collection box 40 has a box body 41 made of synthetic resin. An arrow 30a indicating the rotation direction of the cutting blade 30 (counterclockwise in Figure 1) is displayed on the right side of the box body 41.

[0033] The box body 41 extends in the front-to-rear and up-down directions and has a box shape that is thin in the left-to-right width direction (the thickness direction of the cutting blade 30). The box body 41 has a two-part structure divided into left and right parts. The box body 41 includes a first body portion 42 on the right side and a second body portion 43 on the left side. The first body portion 42 and the second body portion 43 are joined together facing each other to form the box body 41. In the figure, the joint between the first body portion 42 and the second body portion 43 is indicated by the symbol J. As shown in FIG. 13, the first body portion 42 and the second body portion 43 are joined together at the front, rear, and top by three fixing screws 41a. The three fixing screws 41a are fastened from the second body portion 43 side. Therefore, the fixing screws 41a are not visible from the first body portion 42 side.

[0034] FIG. 11 shows the inner surface of the first body portion 42 separated from the second body portion 43. Three screw holes 42b are provided around the periphery of the first body portion 42, into which the fixing screws 41a are fastened. The first body portion 42 is formed from a translucent polycarbonate (first synthetic resin). An aluminum heat-resistant plate 42a is attached to the inner surface of the first body portion 42. The heat-resistant plate 42a is attached to the inside of the first body portion 42 by press-fitting. As shown in FIGS. 5 and 11, the heat-resistant plate 42a covers approximately the lower half of the inner surface of the first body portion 42, including the area behind the center of the cutting blade 30 and some areas in front and in the middle. The translucency of the heat-resistant plate 42a allows the amount of collected chips to be visually observed in the upper half of the area not covered by the heat-resistant plate 42a. As shown in FIGS. 1 and 2, the area (translucent portion 40a) where the amount of collected chips can be visually observed due to the translucency of the first body portion 42 is indicated by a grid-like diagonal line.

[0035] 6 and 11, the entire vertical range of the inner surface of the first main body portion 42 in the middle and the area rearward of the center of the cutting blade 30 is covered with a heat-resistant plate 42a. This improves the heat resistance of the entire vertical range of the first main body portion 42.

[0036] 12 shows the inner surface of the second body 43 separated from the first body 42. The second body 43 is made of a highly heat-resistant glass fiber-reinforced polyamide (second synthetic resin). As shown in FIGS. 2, 3, 5, and 6, the width W2 of the cutting blade 30 of the second body 43 in the thickness direction is greater than the width W1 of the cutting blade 30 of the first body 42 in the thickness direction. By increasing the width W2 of the highly heat-resistant second body 43, the heat resistance of the dust collection box 40 is further improved.

[0037] 12, a dust collection port 43a is provided on the inner front surface side of the second main body portion 43. The chips blown up into the fixed cover 35 are carried by the current of air generated by the rotation of the cutting blade 30 and passed through the dust collection duct portion 35b to be collected into the box main body 41 from the dust collection port 43a, which corresponds to the entrance of the dust collection box 40. The dust collection port 43a is located above the dust collection duct 35b.

[0038] As shown in FIG. 6, the dust collection box 40 is fixed to the fixed cover 35 by tightening a fixing screw 44. As shown in FIGS. 6 and 7, the fixing screw 44 is tightened into a threaded hole 25b in a flange portion 25a provided on the right side of the gear housing 25. As shown in FIGS. 1, 8 to 10, a large knob 45 is attached to the right end of the fixing screw 44. This ensures ease of tightening and loosening the fixing screw 44. The dust collection box 40 can be removed by loosening the fixing screw 44 and removing it from the threaded hole 25b. The knob 45 is positioned within a circular recess 40b provided on the right side of the box body 41. This prevents the knob 45 from protruding, allowing the dust collection box 40 to be made more compact in the left-right width direction.

[0039] As shown in Figures 10 and 13, a discharge port 46 for discharging chips and a vent 47 are provided at the rear of the box body 41. The discharge port 46 has a rectangular opening. The discharge port 46 is opened and closed by a lid 50. As shown in Figures 8 to 10, the lid 50 is supported by a support shaft 41b provided at the rear of the box body 41 so as to be rotatable up and down. The support shaft 41b protrudes on both the left and right sides.

[0040] The lid 50 is made of the same glass fiber-reinforced polyamide material as the second main body portion 43 of the box body 41. As shown in Figures 14 and 15, the lid 50 has a pair of left and right hinge portions 51, 52 connected to left and right support shaft portions 41b, and arm portions 53 extending in the bending direction from the ends of the hinge portions 51, 52. The support shaft portions 41b are inserted into connecting holes 51a, 52a of the left and right hinge portions 51, 52, respectively, to support the lid 50 so that it can rotate up and down.

[0041] As shown in FIG. 14, the plate thickness d1 of the right hinge portion 51 is thicker than the plate thickness d2 of the left hinge portion 52. Therefore, the right hinge portion 51 is harder than the left hinge portion 52. This facilitates assembling the lid 50 to the box body 41. By first connecting the harder right hinge portion 51 to the support shaft 41b, the softer left hinge portion 52 can be easily connected to the support shaft 41b later. As shown in FIGS. 8 to 10, a recess 51b formed by a so-called recess is formed on the right side surface of the right hinge portion 51. This reduces molding costs.

[0042] As shown in Figures 13 to 15, arm 53 is provided with recess 54. Recess 54 is recessed toward hinge portions 51 and 52 (forward). Recess 54 has an annular wall portion 54a that protrudes forward, and a bottom portion 54b that covers the end of wall portion 54a. Heat dissipation portion 55 is provided inside recess 54. Heat dissipation property of lid 50 is improved by heat dissipation portion 55. This improves operability when opening and closing lid 50.

[0043] The heat dissipation portion 55 has a plurality of protrusions 55a. In this embodiment, the four protrusions 55a are provided within the recess 54. The four protrusions 55a extend parallel to one another at regular intervals along the left-right direction. The four protrusions 55a extend from the bottom 54b of the recess 54 in a direction perpendicular to the rotation direction of the lid 50 (in the tangent direction of an arc centered on the support shaft portion 41b). Ends of the four protrusions 55a are connected to the wall 54a of the recess 54. This connects the ends of the four protrusions 55a to each other via the wall 54a, thereby increasing the support rigidity of each. The four protrusions 55a also increase the rigidity of the recess 54.

[0044] The four ridges 55a and recesses 54 increase the surface area of ​​the lid 50 on the outside air side, thereby improving the heat dissipation properties of the lid 50. As shown in Fig. 13, the recesses 54 extend into the exhaust port 46 when the lid 50 is closed. This allows the rear portion of the dust collection box 40 to be made more compact when the lid 50 is closed. Furthermore, the recesses 54 and heat dissipation portion 55 extend into the interior of the exhaust port 46, thereby facilitating heat dissipation around the exhaust port 46.

[0045] The lid 50 has an engagement piece 56. The engagement piece 56 extends from the end of the arm portion 53 in a direction bending toward the hinge portions 51 and 52. A rectangular engagement hole 57 is provided in the engagement piece 56. When the lid 50 is closed, the lower edge of the engagement hole 57 elastically engages with the engagement portion 49 provided on the rear surface of the dust collection box 40. When the lid 50 is in the closed state, the lower edge of the engagement hole 57 elastically engages with the engagement portion 49, thereby holding the lid 50 in the closed position. The rear surface of the engagement portion 49 is inclined in a direction that displaces forward as it approaches the lower side. This improves the ease with which the lower portion of the engagement hole 57 engages and disengages with the engagement portion 49 when opening or closing the lid 50 (the ease of opening and closing the lid 50).

[0046] As shown in Figures 9, 10, and 13, a vent hole 47 is provided on the rear surface of the dust collection box 40. The vent hole 47 is covered with a metal vent plate 48, commonly known as punched metal. The vent plate 48 has a plurality of small-diameter vent holes 48a formed therein. The vent plate 48 ensures the heat resistance and ventilation of the vent hole 47. As shown in Figures 9 and 13, when the lid 50 is closed, the vent hole 47 faces the upper part of the engagement hole 57. Therefore, the vent hole 47 is not blocked by the closed lid 50. As a result, ventilation and heat exhaust from the inside of the box body 41 are smoothly achieved through the vent hole 47 when the lid 50 is closed.

[0047] A knob 58 is provided at the lower end of the engagement piece 56. The knob 58 extends in a direction away from the box body 41. By pinching the knob 58 and pulling it in a direction away from the box body 41, the engagement portion 49 is disengaged from the lower edge of the engagement hole 57. The lid 50 can be opened by pulling the knob 58 upward in this state. When closing the lid 50, the knob 58 is pulled downward while being brought closer to the box body 41, so that the lower edge of the engagement hole 57 can engage with the engagement portion 49. The knob 58 improves operability when opening and closing the lid 50.

[0048] According to the portable metalworking cutting machine 1 of this embodiment configured as described above, the lid 50 that opens and closes the exhaust port 46 of the dust collection box 40 has a heat dissipation section 55. This allows the heat of the lid 50 to be efficiently dissipated by the heat dissipation section 55, thereby improving operability when opening and closing the lid.

[0049] According to the embodiment, the box body 41 of the dust collection box 40 has a two-part structure divided into a first body portion 42 and a second body portion 43. The first body portion 42 is made of polycarbonate (first synthetic resin) and has an aluminum heat-resistant plate 42a integrated into its inner surface. The second body portion 43 is made of glass fiber-reinforced polyamide (second synthetic resin), which has higher heat resistance than polycarbonate. As a result, the metal members are disposed only in the first body portion 42, thereby reducing the weight of the dust collection box 40, and the second body portion 43 improves the heat resistance of the dust collection box 40.

[0050] According to the embodiment, the heat dissipation portion 55 includes a plurality of ridges 55a. Therefore, the surface area of ​​the lid 50 is increased by the plurality of ridges 55a, and heat is dissipated efficiently.

[0051] According to the embodiment, the plurality of ridges 55a are arranged parallel to one another, so that a flow path for the outside air is secured between the ridges 55a, thereby improving the heat dissipation property of the lid 50.

[0052] According to the embodiment, the lid 50 is rotatably connected to the box body 41 of the dust collection box 40. The plurality of ridges 55a extend in a direction perpendicular to the rotation direction of the lid 50. The lid 50 has a wall portion 54a connecting the ends of the plurality of ridges 55a together, thereby increasing the support rigidity of the plurality of ridges 55a.

[0053] According to the embodiment, the lid 50 has hinge portions 51, 52 rotatably connected to the box body 41 of the dust collection box 40. Arm portions 53 extend in the bending direction from the ends of the hinge portions 51, 52. The arm portions 53 have recesses 54 recessed toward the hinge portions 51, 52. Therefore, the arm portions 53 are less likely to bend, thereby increasing the rigidity of the lid 50 without increasing its size. Furthermore, the recesses 54 increase the surface area of ​​the arm portions 53, thereby improving heat dissipation.

[0054] According to the embodiment, the recess 54 is inserted into the outlet 46 when the lid 50 is in the closed state. Therefore, the lid 50 can be made compact when in the closed state.

[0055] According to the embodiment, recess 54 has an annular wall 54a extending from arm 53 toward hinge portions 51 and 52, and a bottom 54b covering the end of wall 54a. Heat dissipation portion 55 has a plurality of ridges 55a protruding from bottom 54b toward arm 53. Therefore, the plurality of ridges 55a are arranged inside recess 54, making heat dissipation portion 55 more compact.

[0056] According to the embodiment, the lid 50 has an engagement piece 56 that extends from the end of the arm portion 53 in a direction bending toward the hinge portions 51 and 52. The engagement piece 56 has an engagement hole 57 that engages with the engagement portion 49 provided on the dust collection box 40. Therefore, the engagement portion 49 engages with the engagement hole 57 of the engagement piece 56, thereby holding the lid 50 in the closed position. In addition, the hinge portions 51 and 52, the arm portion 53, and the engagement piece 56 are arranged in a curved shape that follows the shape of the rear surface of the box body 41, thereby increasing the rigidity of the lid 50. This improves the operability of opening and closing the lid 50.

[0057] According to the embodiment, the dust collection box 40 has a vent 47 for communicating the interior with the outside air. The vent 47 is covered with a metal vent plate 48 having a plurality of vent holes 48a formed therein. The engagement hole 57 of the lid 50 faces the vent 47 (vent holes 48a). Therefore, when the lid 50 is closed, the vent 47 (vent holes 48a) is kept breathable.

[0058] According to the embodiment, the lid 50 has a knob 58 extending from the end of the engagement piece 56 in a direction away from the box body 41. The knob 58 improves the operability when opening and closing the lid 50.

[0059] According to the embodiment, polycarbonate (first synthetic resin), which is the material of the first main body portion 42, is translucent. As a result, the first main body portion 42 is provided with a translucent portion 40a. The translucent portion 40a ensures visibility of the amount of collected chips.

[0060] According to the embodiment, the box body 41 has a first body portion 42 on one side in the thickness direction of the cutting blade 30 and a second body portion 43 on the other side. The width W2 in the thickness direction of the second body portion 43 is larger than the width W1 in the thickness direction of the first body portion 42. Therefore, high heat resistance of the dust collection box 40 is ensured.

[0061] According to the embodiment, the second body portion 43 of the dust collection box 40 is made of a material containing polyamide as the second synthetic resin and also containing glass fiber, thereby ensuring high heat resistance of the second body portion 43.

[0062] Various modifications can be made to the embodiment described above. For example, although the four ridges 55a of the heat dissipation portion 55 extend in the left-right direction in the example described above, they may extend in the up-down direction. Furthermore, multiple ridges may extend in a lattice pattern.

[0063] Although the example shows a configuration in which multiple protrusions 55a are arranged within recess 54 and do not protrude from the surface of arm portion 53, recess 54 may be omitted and multiple protrusions may protrude from a portion of the surface of arm portion 53.

[0064] Although the left and right hinge portions 51, 52 of the lid 50 have different thicknesses d1, d2, they may have the same thickness. The recess 51b as a recess for reducing material may be omitted.

[0065] Although the lid 50 that opens and closes by rotating up and down has been exemplified, the heat dissipation section 55 exemplified above can also be applied to a lid that opens and closes by sliding up and down, for example.

[0066] The material of the second main body portion 43 may be changed from glass fiber-reinforced polyamide to other highly heat-resistant resins.

[0067] The lid 50 may be made of the same highly heat-resistant resin material as the second main body portion 43, such as glass fiber-reinforced polyamide.

[0068] The aluminum heat-resistant plate 42a of the first main body portion 42 may be changed to a heat-resistant plate made of sheet metal (iron plate).

[0069] The first body portion 42 of the box body 41 may also be formed from glass fiber-reinforced polyamide, as with the second body portion 43, except for the window portion for visually checking the remaining amount of collected dust. In this case, the heat-resistant plate 42a may be omitted. The window portion for visually checking the remaining amount of collected dust may be configured by fitting a separate transparent plate made of translucent polycarbonate. Furthermore, the box body need not be a two-piece structure, left and right, as illustrated, but may be a single molded member formed by blow molding or the like.

[0070] The portable metalworking cutting machine 1 of the embodiment is an example of a portable metalworking cutting machine in one aspect of the present disclosure. The cutting blade 30 (metal tipped saw) of the embodiment is an example of a cutting blade in one aspect of the present disclosure. Instead of a tipped saw cutter that uses a metal tipped saw, the portable metalworking cutting machine may use a diamond wheel or a grinding wheel. The cutting machine main body 20 of the embodiment is an example of a cutting machine main body in one aspect of the present disclosure. The dust collection box 40 of the embodiment is an example of a dust collection box in one aspect of the present disclosure.

[0071] The exhaust port of the embodiment is an example of an exhaust port according to an aspect of the present disclosure. The lid of the embodiment is an example of a lid according to an aspect of the present disclosure. The heat dissipation unit of the embodiment is an example of a heat dissipation unit according to an aspect of the present disclosure.

[0072] Box body 41 of the embodiment is an example of a box body in another aspect of the present disclosure. First body portion 42 of the embodiment is an example of a first body portion in another aspect of the present disclosure. Polycarbonate of the embodiment is an example of a first synthetic resin in another aspect of the present disclosure. Heat-resistant plate 42a of the embodiment is an example of a metal plate in another aspect of the present disclosure. Second body portion 43 of the embodiment is an example of a second body portion in another aspect of the present disclosure. Glass-fiber-reinforced polyamide of the embodiment is an example of a second synthetic resin in another aspect of the present disclosure. [Explanation of symbols]

[0073] 1...Portable cutting machine for metalwork (tip saw cutter) 2…Cut material 3... Cutting site 10...Bass 11...Battery pack 20…Cutting machine body 21...Electric motor (brushless motor) 22...Reduction gear section 23...Output shaft 24...Motor housing 25...Gear housing 25a... flange portion, 25b... screw hole 26...Handle 27...Switch lever 28...Battery mounting section 30...cutting blade 30a...arrow (rotation direction of cutting blade 30) 31...Outer flange 32...Inner flange 33...Fixing screw 35...Fixed cover 35a...arrow (rotation direction of cutting blade 30), 35b...dust collection duct part, 35c...metal plate 35d...Fixing screw 36... Movable cover 37...Swing support part 40...Dust collection box 40a...Transparent part, 40b...Concave part 41...Box body 41a...fixing screw, 41b...support shaft 42...First main body portion 42a...heat-resistant plate, 42b...screw hole W1: Width of the first main body portion 42 43...Second main body part 43a...Dust collection port W2: Width of the second main body portion 43 44...Fixing screw 45...Knob 46…Discharge port 47...Ventilation hole 48...Ventilation board 48a...vent 49...Engagement part 50…Lid 51...Hinge part (right) 51a...connecting hole, 51b...recess (thin part) d1: Plate thickness of hinge part 51 52...Hinge part (left) 52a...Connection hole d2: Plate thickness of hinge part 52 53...Arm 54...recess 54a...Wall part, 54b...Bottom part 55...Heat radiation part 55a...projection 56...Engagement piece 57...Engagement hole 58...Knob

Claims

1. A portable metalworking cutting machine, A cutting machine body having a cutting blade; Equipped with a dust collection box to collect chips generated by cutting, The box body of the dust collection box includes a first body portion made of a first synthetic resin and having a metal plate integrated with an inner surface thereof, and a second body portion made of a second synthetic resin having a higher heat resistance than the first synthetic resin, A portable metalworking cut-off machine having the first main body portion on one side of the cutting blade in the thickness direction and the second main body portion on the other side, wherein the width of the second main body portion in the thickness direction is greater than the width of the first main body portion in the thickness direction.

2. A portable cutting machine for metalworking according to claim 1, A portable metalworking cut-off machine, wherein the first body portion is positioned farther away from the cutting blade than the second body portion is in relation to the position of the cutting blade in the thickness direction of the plate.

3. A portable metalworking cutting machine according to claim 1 or 2, The first synthetic resin of the first body portion is translucent.

4. A portable cutting machine for metalworking as described in claim 3, The first main body portion has a translucent upper portion and a metal plate at a lower portion in a front-to-rear direction region including the center of the cutting blade.

5. A portable cutting machine for metalworking as described in claim 4, The first main body portion has the metal plate over the entire vertical range in an area rearward from the center of the cutting blade.

6. A portable metalworking cutting machine according to claim 1 or 2, The second body portion is formed from a material that contains polyamide as the second synthetic resin and also contains glass fiber.

7. A portable metalworking cutting machine, A cutting machine body having a cutting blade; Equipped with a dust collection box to collect chips generated by cutting, The dust collection box includes an outlet for discharging chips and a lid for opening and closing the outlet. The lid of this portable metalworking cutting machine has a heat dissipation portion on part of its surface.

8. 8. A portable metalworking cutting machine according to claim 7, The heat dissipation portion of the portable metalworking cutter includes a plurality of ridges.

9. 9. The portable metalworking cutting machine according to claim 8, A portable metalworking cut-off machine in which the multiple ridges are arranged parallel to each other.

10. A portable metalworking cutting machine according to claim 8 or 9, The lid is rotatably connected to the box body of the dust collection box, The plurality of protrusions extend in a direction perpendicular to a rotation direction of the lid, The cover has a wall portion connecting the ends of the plurality of ridges.

11. A portable metalworking cutting machine according to any one of claims 7 to 9, The lid of the portable metalworking cutting machine has a hinge portion rotatably connected to the box body of the dust collection box, an arm portion extending in a bending direction from an end of the hinge portion, and a recess extending from the arm portion toward the hinge portion.

12. 12. The portable metalworking cutting machine according to claim 11, The recess of the portable metalworking cutting machine is inserted into the discharge outlet when the lid is in a closed state.

13. 12. The portable metalworking cutting machine according to claim 11, the recess has an annular wall portion extending from the arm portion toward the hinge portion and a bottom portion covering an end of the wall portion, The heat dissipation section of this portable metalworking cutter has a plurality of protrusions protruding from the bottom section toward the arm section.

14. 12. The portable metalworking cutting machine according to claim 11, The lid has an engagement piece extending from the end of the arm portion in a direction bending toward the hinge portion, and the engagement piece has an engagement hole that engages with an engagement portion provided on the dust collection box.

15. 15. The portable metalworking cut-off machine of claim 14, The dust collection box has a metal ventilation plate having a plurality of ventilation holes formed therein, The engagement hole faces the vent plate.

16. 15. A portable metalworking cutting machine according to claim 14, The lid of the portable metalworking cutter has a knob extending from the end of the engagement piece in a direction away from the box body.

17. A portable metalworking cutting machine according to any one of claims 7 to 9, The box body of the dust collection box of this portable metalworking cutting machine comprises a first body portion in which a first synthetic resin and a metal are integrated, and a second body portion made of a second synthetic resin having higher heat resistance than the first synthetic resin.

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