Portable cutting machine 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 cutting machine for metalworking that performs cutting of metal by a worker holding and moving it by hand.

Background Art

[0002] For example, a portable cutting machine for metalworking that uses a chip saw for metal, which is also called a chip saw cutter, has a dust collection box for collecting sparks generated by cutting and hot chips generated due to the decrease in the temperature of the sparks. As disclosed in Patent Document 1, the rear part of the dust collection box has an outlet for discharging the collected chips for disposal. The outlet is opened and closed by a lid. The user can discard the chips collected in the dust collection box by opening the lid and discharging them from the outlet. Incidentally, a chip saw is a type of cutting blade in which a chip and a base metal are manufactured as separate parts and integrated by welding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the lid may become hot due to the chips collected in the dust collection box, special attention is required especially when opening and closing the lid. In this regard, it was necessary to improve the operability of the lid. The purpose of the present disclosure is to improve the operability of the lid of the outlet for the dust collection box of the portable cutting machine for metalworking.

Means for Solving the Problems

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

[0006] Therefore, heat from the lid is efficiently dissipated by the heat dissipation section. This prevents the lid from becoming hot, improving ease of opening and closing.

[0007] According to other aspects of this disclosure, a portable metalworking cutting machine comprises, for example, a cutting machine 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 main body made of a first synthetic resin with a metal plate integrated on its inner surface, and a second main body made of a second synthetic resin having higher heat resistance than the first synthetic resin.

[0008] Therefore, by placing metal only in the first main body, the weight of the dust collection box is reduced, while the heat resistance of the dust collection box is enhanced by the second main body. [Brief explanation of the drawing]

[0009] [Figure 1] This is a right side view of a portable metalworking cutting machine according to this embodiment. [Figure 2] This is a view from arrow II in Figure 1, and is a plan view of a portable metalworking cutting machine. [Figure 3] This is a view from arrow III in Figure 1, and is a front view of a portable metalworking cutting machine. [Figure 4] This is a view from arrow IV in Figure 1, and is a rear view of a portable metalworking cutting machine. [Figure 5] Figure 1 shows a cross-sectional view taken along line VV. [Figure 6] Figure 1 shows a cross-sectional view taken along the line VI-VI. [Figure 7] This 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. This diagram shows the view from the front right. [Figure 9] This is a perspective view of the dust collection box. This diagram shows the box viewed from the right rear. This diagram shows the box with the lid closed. [Figure 10] This is a perspective view of the dust collection box. This diagram shows the box viewed from the right rear. This diagram shows the box with the lid open. [Figure 11] This is a perspective view of the first main body. This figure is a view from the inside of the box body, specifically a perspective view from the left rear. [Figure 12] This is a perspective view of the second main body. This figure is a view from the inside of the box body, specifically a perspective view from the right rear. [Figure 13] This is a vertical cross-sectional view of the dust collection box. This diagram shows the box with the lid closed. [Figure 14] This is a rear view of the lid. [Figure 15] Figure 14 shows a cross-sectional view taken along the line XV-XV, which is a longitudinal cross-section of the lid. [Modes for carrying out the invention]

[0010] In one or more embodiments, for example, the heat dissipation section includes a plurality of protrusions. Therefore, the surface area of ​​the lid is increased by the plurality of protrusions, allowing heat to be dissipated efficiently.

[0011] In one or more embodiments, for example, multiple protrusions are arranged parallel to each other. Therefore, heat dissipation is enhanced by allowing outside air to flow more easily between the protrusions.

[0012] In one or more embodiments, for example, a lid is rotatably connected to the box body of the dust collection box. Multiple protrusions extend in a direction perpendicular to the rotation direction of the lid, for example. The lid has, for example, a wall that connects the ends of the multiple protrusions. Thus, the support rigidity of the multiple protrusions 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 portion of the hinge portion, and a recess recessed from the arm portion toward the hinge portion side. Therefore, the rigidity of the lid is enhanced without causing an increase in size because the arm portion is less likely to bend. Further, the heat dissipation property is enhanced because the surface area of the arm portion is increased by the recess.

[0014] In one or more embodiments, for example, the recess enters the discharge port in the closed state of the lid. Therefore, the compactness in the closed state of the lid is achieved.

[0015] In one or more embodiments, for example, the recess has an annular wall portion extending from the arm portion toward the hinge portion side and a bottom portion covering an end portion of the wall portion. For example, the heat dissipation portion has a plurality of protrusions protruding from the bottom portion toward the arm portion side. Therefore, a plurality of protrusions are arranged in the recess, and the compactness of the heat dissipation portion is achieved.

[0016] In one or more embodiments, for example, the lid has an engagement piece extending in a direction bending from an end portion of the arm portion toward the hinge portion side. For example, the engagement piece has an engagement hole that engages with an engagement portion provided on the dust collection box. Therefore, the lid is held in the closed position by engaging the engagement portion with the engagement hole of the engagement piece. Further, the operability during opening and closing is improved because the hinge portion, the arm portion, and the engagement piece are arranged in a curved shape.

[0017] [[ID=十六]]In one or more embodiments, for example, the dust collection box has a metal ventilation plate in which a plurality of ventilation holes are formed. For example, the engagement hole faces the ventilation plate. Therefore, the air permeability of the ventilation holes is ensured in the closed state of the lid.

[0018] In one or more embodiments, for example, the lid has a knob portion extending in a direction away from the box body from an end portion of the engagement piece. The operability during opening and closing of the lid is enhanced by the knob portion.

[0019] ]>In one or more embodiments, for example, the box body of a dust collection box comprises a first body part in which a first synthetic resin and metal are integrated, and a second body part made of a second synthetic resin having higher heat resistance than the first synthetic resin. Therefore, the weight of the dust collection box is reduced by placing the metal only in the first body part, and the heat resistance of the dust collection box is increased by the second body part.

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

[0021] In one or more embodiments, for example, the box body has a first body portion on one side in the thickness direction of the cutting blade 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. Therefore, high heat resistance of the dust collection box is ensured.

[0022] In one or more embodiments, for example, the second main body is formed from a material containing polyamide as the second synthetic resin and also containing glass fibers. Therefore, high heat resistance of the second main body is ensured. [Examples]

[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 cutting saw blade, also called a carbide-tipped saw cutter, and comprises a base 10 that contacts the upper surface of the material to be cut 2, and a cutting machine body 20 supported on the upper side of the base 10. The base 10 has a rectangular flat plate shape, and its lower side contacts the upper surface of the material to be cut 2. In Figures 1 and 2, the user is positioned to the left of the portable metalworking cutting machine 1 and operates the machine to move it to the right. This proceeds with the cutting process. In the following description, the cutting direction is considered the front, and the user's side is considered the rear. The left and right directions are based on the user.

[0024] As shown in Figures 5-7, the cutting machine body 20 is equipped with an electric motor 21 as a drive source and a disc-shaped cutting blade 30 that rotates with the electric motor 21. The electric motor 21 is a brushless motor that is high-output and compact in the motor axis direction. The rotational output of the electric motor 21 is output to the output shaft 23 via the reduction gear section 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 circumference of the handle 26. The electric motor 21 is started by turning on the switch lever 27 with the fingertips of the hand gripping 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. The battery pack 11 uses a slide-removable lithium-ion battery. The electric motor 21 is started using the power from 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 recharged with a separately provided charger for repeated use.

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

[0028] The upper half of the cutting blade 30 (the area 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 material 2, chips are generated from the cutting area 3. The chips are blown upward by the rotation of the cutting blade 30. A rectangular tubular dust collection duct 35b is provided at the front of the fixed cover 35. The dust collection duct 35b is positioned above the cutting area 3. A steel metal plate 35c is provided on the front inner surface of the dust collection duct 35b. The metal plate 35c protects the fixed cover 35 from impact by high-temperature chips. As a result, the chips blown up from the cutting area 3 flow into the dust collection box 40 via the dust collection duct 35b.

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

[0030] The movable cover 36 covers approximately half of the lower circumference of the cutting blade 30 (the area on the underside of the base 10). The movable cover 36 is rotatably supported on the right side of the gear housing 25. As the movable cover 36 rotates, the cutting edge of the cutting blade 30 opens and closes on the underside of the base 10. The movable cover 36 is biased in the closing direction. As the cutting process progresses due to the movement operation of the portable metalworking cutting machine 1, the movable cover 36, which is in contact with the material to be cut 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 37. The cutting machine body 20 is supported by the swing support 37 so that it can swing vertically. By changing the vertical swing position of the cutting machine body 20, the cutting depth of the cutting blade 30 into the material to be cut 2 can be adjusted.

[0032] A dust collection box 40 for collecting chips that flow into the inside of the fixed cover 35 is detachably attached to the right side of the fixed cover 35. Figures 8 to 10 show the dust collection box 40 detached 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-back and up-to-down directions and has a thin box shape in the left-to-right width direction (the thickness direction of the cutting blade 30). The box body 41 has a two-part structure, left and right. The box body 41 comprises a first body part 42 on the right side and a second body part 43 on the left side. The box body 41 is formed by the first body part 42 and the second body part 43 facing each other and being joined together. In the figure, the joint between the first body part 42 and the second body part 43 is indicated by the symbol J. As shown in Figure 13, the first body part 42 and the second body part 43 are joined together at the front, rear and top by three fixing screws 41a. The three fixing screws 41a are tightened from the second body part 43 side. Therefore, the fixing screws 41a are not visible from the first body part 42 side.

[0034] Figure 11 shows the inner surface of the first main body 42, which has been separated from the second main body 43. Three screw holes 42b are provided around the perimeter of the first main body 42, into which fixing screws 41a are tightened. The first main body 42 is made of translucent polycarbonate (first synthetic resin). An aluminum heat-resistant plate 42a is bonded to the inner surface of the first main body 42. The heat-resistant plate 42a is bonded to the inside of the first main body 42 by press-fitting. As shown in Figures 5 and 11, the lower half of the inner surface of the first main body 42, in the area behind the center of the cutting blade 30 and in some areas in front and in the middle, is covered by the heat-resistant plate 42a. In the upper half, which is not covered by the heat-resistant plate 42a, the amount of chips collected can be visually inspected due to its translucency. As shown in Figures 1 and 2, the area (translucent area 40a) in which the amount of dust collected inside the first main body 42 can be visually inspected due to its translucency is indicated by a grid of diagonal lines.

[0035] As shown in Figures 6 and 11, the entire vertical range of the inner surface of the first main body 42, specifically the area in the middle and behind the center of the cutting blade 30, is covered by a heat-resistant plate 42a. This enhances the heat resistance of the entire vertical range of the first main body 42.

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

[0037] As shown in Figure 12, a dust collection port 43a is provided on the front inner surface of the second main body 43. The chips blown into the fixed cover 35 are carried by the airflow generated by the rotation of the cutting blade 30, pass through the dust collection duct 35b, and are collected into the box body 41 through the dust collection port 43a, which corresponds to the entrance of the dust collection box 40. The dust collection port 43a is positioned above the dust collection duct 35b.

[0038] As shown in Figure 6, the dust collection box 40 is fixed to the fixing cover 35 by tightening fixing screws 44. As shown in Figures 6 and 7, the fixing screws 44 are tightened into screw holes 25b in flange portion 25a provided on the right side of the gear housing 25. As shown in Figures 1, 8 to 10, a large knob 45 is attached to the right end of the fixing screw 44. This ensures ease of operation when tightening and loosening the fixing screw 44. The dust collection box 40 can be removed by loosening the fixing screw 44 and pulling it out of the screw hole 25b. The knob 45 is located in a circular recess 40b provided on the right side of the box body 41. This eliminates the protrusion of the knob 45, resulting in a more compact design in the width direction of the dust collection box 40.

[0039] As shown in Figures 10 and 13, the rear of the box body 41 is provided with a chip discharge port 46 and a ventilation port 47. The discharge port 46 is rectangular in shape. The discharge port 46 is opened and closed by a lid 50. As shown in Figures 8 to 10, the lid 50 is supported so as to be able to rotate up and down via a support shaft portion 41b provided at the rear of the box body 41. The support shaft portion 41b protrudes from both the left and right sides.

[0040] The lid 50 is made of glass fiber-reinforced polyamide, the same 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 and 52 connected to the left and right support shaft portions 41b, and arm portions 53 extending in the bending direction from the ends of the hinge portions 51 and 52. The support shaft portions 41b are inserted into the connecting holes 51a and 52a of the left and right hinge portions 51 and 52, respectively, so that the lid 50 is supported to rotate up and down.

[0041] As shown in Figure 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 stiffer than the left hinge portion 52. This makes it easier to assemble the lid 50 to the box body 41. By connecting the stiffer right hinge portion 51 to the support shaft portion 41b first, the softer left hinge portion 52 can be easily connected to the support shaft portion 41b later. As shown in Figures 8 to 10, a recess 51b is formed on the right side of the right hinge portion 51 by so-called material removal. This reduces molding costs.

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

[0043] The heat dissipation section 55 has multiple protrusions 55a. In this embodiment, there are four protrusions 55a. The four protrusions 55a are provided within the recess 54. The four protrusions 55a extend parallel to each other at a constant distance along the left-right direction. The four protrusions 55a extend from the bottom 54b of the recess 54 in a direction perpendicular to the rotational direction of the lid 50 (tangential direction of the arc centered on the support shaft 41b). The ends of the four protrusions 55a are connected to the wall portion 54a of the recess 54. As a result, the ends of the four protrusions 55a are connected to each other at the wall portion 54a, increasing the support rigidity of each. In addition, the rigidity of the recess 54 is increased by the four protrusions 55a.

[0044] The four protrusions 55a and recesses 54 increase the surface area of ​​the lid 50 on the outside air side, thereby improving the heat dissipation of the lid 50. As shown in Figure 13, the recesses 54 enter the outlet 46 when the lid 50 is closed. This makes the rear of the dust collection box 40 more compact when the lid 50 is closed. In addition, the recesses 54 and the heat dissipation section 55 enter the inside of the outlet 46, which promotes heat dissipation around the outlet 46.

[0045] The lid 50 has an engaging piece 56. The engaging piece 56 extends from the end of the arm portion 53 in a direction that bends toward the hinge portions 51 and 52. A rectangular engaging hole 57 is provided in the engaging piece 56. When the lid 50 is closed, the lower edge of the engaging hole 57 elastically engages with an engaging portion 49 provided on the rear surface of the dust collection box 40. The elastic engagement of the lower edge of the engaging hole 57 with the engaging portion 49 when the lid 50 is closed holds the lid 50 in the closed position. The rear surface of the engaging portion 49 is inclined in a direction that displaces further forward towards the lower side. This improves the ease of engaging and disengaging the lower part of the engaging hole 57 with the engaging portion 49 (the ease of opening and closing the lid 50) when opening and closing the lid 50.

[0046] As shown in Figures 9, 10, and 13, a ventilation opening 47 is provided on the rear surface of the dust collection box 40. The ventilation opening 47 is covered with a metal ventilation plate 48, commonly known as perforated metal. Multiple small-diameter ventilation holes 48a are formed in the ventilation plate 48. The ventilation plate 48 ensures the heat resistance and ventilation of the ventilation opening 47. As shown in Figures 9 and 13, when the lid 50 is closed, the ventilation opening 47 is positioned opposite the upper part of the engagement hole 57. Therefore, the ventilation opening 47 is not blocked by the closed lid 50. This allows for smooth ventilation and heat dissipation inside the box body 41 through the ventilation opening 47 when the lid 50 is closed.

[0047] A handle 58 is provided at the lower end of the engaging piece 56. The handle 58 extends away from the box body 41. By grasping the handle 58 and pulling it away from the box body 41, the engaging portion 49 is disengaged from the lower edge of the engaging hole 57. The lid 50 can then be opened by pulling the handle 58 upward. When closing the lid 50, the lower edge of the engaging hole 57 can be engaged with the engaging portion 49 by pulling the handle 58 downward and bringing it closer to the box body 41. The handle 58 improves the operability when opening and closing the lid 50.

[0048] In this embodiment of the portable metalworking cutting machine 1 configured as described above, the lid 50 that opens and closes the discharge port 46 of the dust collection box 40 has a heat dissipation section 55. As a result, the heat from the lid 50 is efficiently dissipated by the heat dissipation section 55, 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 left and right two-part structure consisting of a first body part 42 and a second body part 43. The first body part 42 is made of polycarbonate (first synthetic resin) and has a heat-resistant aluminum plate 42a integrated into its inner surface. The second body part 43 is made of glass fiber-reinforced polyamide (second synthetic resin), which has higher heat resistance than polycarbonate. As a result, the weight of the dust collection box 40 is reduced by placing metal components only in the first body part 42, and the heat resistance of the dust collection box 40 is enhanced by the second body part 43.

[0050] According to the embodiment, the heat dissipation section 55 includes a plurality of protrusions 55a. Therefore, the surface area of ​​the lid 50 is increased by the plurality of protrusions 55a, allowing heat to be dissipated efficiently.

[0051] According to the embodiment, the multiple protrusions 55a are arranged parallel to each other. Therefore, a flow path for outside air is secured between the protrusions 55a, thereby improving the heat dissipation performance 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 multiple protrusions 55a extend in a direction perpendicular to the rotation direction of the lid 50. The lid 50 has a wall portion 54a that connects the ends of the multiple protrusions 55a. This increases the support rigidity of the multiple protrusions 55a.

[0053] According to the embodiment, the lid 50 has hinge portions 51 and 52 that are 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 and 52. The arm portions 53 have recesses 54 that are recessed toward the hinge portions 51 and 52. Therefore, the rigidity of the lid 50 is increased without increasing its size by making the arm portions 53 less prone to bending. In addition, the surface area of ​​the arm portions 53 is increased by the recesses 54, which improves heat dissipation.

[0054] According to this embodiment, the recess 54 enters the outlet 46 when the lid 50 is closed. Therefore, the lid 50 can be made more compact when closed.

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

[0056] According to the embodiment, the lid 50 has an engaging piece 56 that extends from the end of the arm portion 53 in a direction that bends toward the hinge portions 51 and 52. The engaging piece 56 has an engaging hole 57 that engages with an engaging portion 49 provided in the dust collection box 40. Therefore, when the engaging portion 49 engages with the engaging hole 57 of the engaging piece 56, the lid 50 is held in the closed position. In addition, the rigidity of the lid 50 is increased by arranging the hinge portions 51 and 52, the arm portion 53 and the engaging piece 56 in a curved shape that follows the rear surface shape of the box body 41. This improves the operability when 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 in which a plurality of ventilation holes 48a are formed. The engagement hole 57 of the lid 50 faces the vent 47 (ventilation holes 48a). Therefore, when the lid 50 is closed, ventilation of the vent 47 (ventilation holes 48a) is ensured.

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

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

[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 of the second body portion 43 in the thickness direction is greater than the width W1 of the first body portion 42 in the thickness direction. Therefore, high heat resistance of the dust collection box 40 is ensured.

[0061] According to the embodiment, the second main body portion 43 of the dust collection box 40 is formed from a material that contains polyamide as the second synthetic resin and also contains glass fibers. Therefore, high heat resistance of the second main body portion 43 is ensured.

[0062] Various modifications can be made to the embodiments described above. For example, although the example shows that the four protrusions 55a of the heat dissipation section 55 extend along the left-right direction, they may also be configured to extend in the vertical direction. Alternatively, multiple protrusions may be configured to extend in a grid pattern.

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

[0064] Although the example shows different plate thicknesses d1 and d2 of the left and right hinge portions 51 and 52 of the lid 50, they may be changed to the same plate thickness. The recess 51b, which serves as a material removal feature, may be omitted.

[0065] Although the example shows a lid 50 that opens and closes by rotating up and down, the heat dissipation section 55 shown 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 43 may be changed from glass fiber-reinforced polyamide to another high heat-resistant resin.

[0067] The lid 50 may be formed from a highly heat-resistant resin such as glass fiber-reinforced polyamide, similar to the second main body 43.

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

[0069] The first main body portion 42 of the box body 41 may also be formed from glass fiber-reinforced polyamide, the same material as the second main body portion 43, except for the window portion for visualizing the remaining dust amount. In this case, the heat-resistant plate 42a may be omitted. The window portion for visualizing the remaining dust amount can be configured by fitting a transparent plate made of translucent polycarbonate separately. Furthermore, the box body may not be a two-part structure as exemplified, but may be a single molded member formed by blow molding or the like.

[0070] The portable metalworking cutting machine 1 in the embodiment is an example of a portable metalworking cutting machine in one aspect of the present disclosure. The cutting blade 30 (metal-cutting circular saw blade) in the embodiment is an example of a cutting blade in one aspect of the present disclosure. Instead of a circular saw cutter using a metal-cutting circular saw blade, a portable metalworking cutting machine using a diamond wheel or grinding wheel may also be used. The cutting machine body 20 in the embodiment is an example of a cutting machine body in one aspect of the present disclosure. The dust collection box 40 in the embodiment is an example of a dust collection box in one aspect of the present disclosure.

[0071] The outlet in the embodiment is an example of an outlet in one aspect of the present disclosure. The lid in the embodiment is an example of a lid in one aspect of the present disclosure. The heat dissipation section in the embodiment is an example of a heat dissipation section in one aspect of the present disclosure.

[0072] The box body 41 in the embodiment is an example of a box body in another aspect of the present disclosure. The first body part 42 in the embodiment is an example of a first body part in another aspect of the present disclosure. The polycarbonate in the embodiment is an example of a first synthetic resin in another aspect of the present disclosure. The heat-resistant plate 42a in the embodiment is an example of a metal plate in another aspect of the present disclosure. The second body part 43 in the embodiment is an example of a second body part in another aspect of the present disclosure. The glass fiber-reinforced polyamide in the embodiment is an example of a second synthetic resin in another aspect of the present disclosure. [Explanation of symbols]

[0073] 1…Portable metalworking cutting machine (carbide-tipped 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...Threaded hole 26... Handle 27… Switch lever 28…Battery mounting section 30...cutting blade 30a...Arrow (direction of rotation of cutting blade 30) 31…Outer flange 32... Inner flange 33… Fixing screws 35…Fixed cover 35a…Arrow (direction of rotation of the cutting blade 30), 35b…Dust collection duct section, 35c…Metal plate 35d... Fixing screw 36…Movable cover 37...Oscillating 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 42a...Heat-resistant plate, 42b...Screw hole W1...Width of the first main body section 42 43...Second main body 43a... Dust collection port W2...Width of the second main body section 43 44… Fixing screws 45... Nobu 46…Discharge port 47...Ventilation opening 48... Ventilation board 48a...Ventilation holes 49...Engaging part 50…Lid 51…Hinge section (right) 51a…Connecting hole, 51b…Recess (material removal) d1... Thickness of the hinge portion 51 52…Hinge section (left) 52a...Connection hole d2... Thickness of the hinge portion 52 53...Arm 54…recess 54a...Wall part, 54b...Bottom part 55...Heat radiation part 55a...projection 56…Engaging piece 57…Engagement hole 58...Pinch part

Claims

1. A portable cutting machine for metalworking, A cutting machine body having a cutting blade, It is equipped with a dust collection box to collect the chips generated by cutting, The dust collection box comprises a first body made of a first synthetic resin with a metal plate integrated into its inner surface, and a second body made of a second synthetic resin having higher heat resistance than the first synthetic resin. A portable metalworking cutting machine having the first main body on one side of the cutting blade in the thickness direction and the second main body on the other side, wherein the width of the second main body in the thickness direction is greater than the width of the first main body in the thickness direction.

2. A portable metalworking cutting machine according to claim 1, A portable metalworking cutting machine in which, with respect to the position of the cutting blade in the thickness direction, the first main body is positioned further away from the cutting blade than the second main body.

3. A portable metalworking cutting machine according to claim 1 or 2, The first synthetic resin of the first main body is a light-transmitting portable cutting machine for metalworking.

4. A portable metalworking cutting machine according to claim 3, The first main body includes the center of the cutting blade, and in a portion of the front-to-back direction perpendicular to the thickness direction of the cutting blade, the upper part has light-transmitting properties and the lower part has a metal plate, making it a portable cutting machine for metalworking.

5. A portable metalworking cutting machine according to claim 4, The first main body is a portable metalworking cutting machine having the metal plate in the entire vertical range in the region behind the center of the cutting blade.

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

7. A portable metalworking cutting machine according to claim 1 or 2, The dust collection box includes an outlet for discharging chips and a lid for opening and closing the outlet. The aforementioned lid is a portable metalworking cutting machine having a heat dissipation section on part of its surface.

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