JP7487026B2 - Portable cutting machine with dust box - Google Patents

Description

This disclosure relates to a portable cutting machine with a dust box. Portable cutting machines include, for example, portable circular saws that are primarily used for cutting wood, or cutters that are primarily used for grinding stone.

Portable cutting machines have various ideas to prevent cutting dust generated by cutting from scattering around. Patent Documents 1 and 2 disclose portable cutting machines equipped with a dust box for collecting cutting dust. Cutting dust flows toward the dust box on the current of wind (dust-collecting wind) generated by the rotation of the cutting tool or exhaust cooling air from the electric motor, and is collected in the dust box. The dust box is provided with a filter for removing cutting dust. Cutting dust is removed from the air by the filter, and only clean air is exhausted outside the dust box, maintaining a good working environment. Cutting dust removed from the air by the filter is accumulated in the dust box and disposed of separately.

Japanese Patent Application Laid-Open No. 4-235001 JP 2014-24177 A

When the filter of the conventional dust box described above becomes clogged with cutting dust, the exhaust efficiency decreases and the pressure inside the dust box increases. This impedes the flow of the dust collection air, reducing the dust collection efficiency. Thus, measures must be taken to prevent the filter from clogging in order to maintain high dust collection efficiency.

According to one feature of the present disclosure, a portable cutting machine with a dust box has a cutting machine body that houses an electric motor, and a cutting tool cover that covers a cutting tool rotated by the electric motor. A dust box that collects cutting dust is provided adjacent to the cutting tool cover. A filtering member is provided in a ventilation opening provided in the dust box. An impact mechanism that applies an impact to the filtering member by operation of the user is provided in the cutting machine body or the dust box.

The impact mechanism therefore applies an impact to the filter member, preventing clogging of the filter member. This prevents an increase in the air resistance of the ventilation opening, and thus prevents an increase in the internal pressure of the dust box. By preventing an increase in internal pressure, the dust collection air containing cutting powder flows smoothly into the dust box, maintaining high dust collection efficiency.

According to another feature of the present disclosure, the impact mechanism has an operating member that is operated by the user. The elastic member is elastically deformed by operating the operating member. The striking member strikes the cutting machine body or the dust box using the elastic force of the elastic member. Therefore, the impact can be generated by the elastic force of the elastic member using the operating force of the user, rather than electricity, etc.

According to another feature of the present disclosure, the striking member is biased in a rotational direction by an elastic member. The cutting machine body or the dust box is struck by the rotational motion of the striking member. Therefore, the strike can be generated with a more compact configuration than a configuration that utilizes linear motion.

According to another feature of the present disclosure, the striking member is elongated. The striking member has an operating member at a first end. Thus, the operating member is disposed on a portion of the striking member, simplifying the configuration.

According to another feature of the present disclosure, the striking member is elastically deformable, and serves both as a striking member and an elastic member. The second end of the striking member is attached to the cutting machine body or the dust box. Thus, by applying an operating force to the first end, the striking member, which is an elastic member, is deformed with the second end as a fulcrum. Therefore, by utilizing the principle of leverage, the striking member can be elastically deformed with a relatively small force.

According to another feature of the present disclosure, the dust box has a first wall in which a ventilation opening is formed and in which the filter member is attached, and a second wall perpendicular to the first wall. An impact mechanism is disposed on the second wall. Therefore, an impact is applied to the filter member from the side, and dust adhering to the filter member is efficiently shaken off.

According to another feature of the present disclosure, the cutting machine body has a handle portion attached to the dust box. The impact mechanism is disposed between the dust box and the handle portion. Therefore, the operating members are arranged compactly by effectively utilizing dead space that does not interfere with work.

According to another feature of the present disclosure, the cutting machine body has a handle section attached to the dust box. The handle section has a switch lever for starting and operating the electric motor. The striking member is long and extends along the handle section. The operating member is disposed at the tip of the striking member, forward of the switch lever. Therefore, operability of both the switch lever and the operating member is ensured. For example, while operating the switch lever with one hand, the operating member can be operated by rotating the other hand forward. By displacing the switch lever and the operating member back and forth, one hand does not get in the way of operation by the other hand.

According to another feature of the present disclosure, a single operation of the operating member causes the striking member to strike the filter member multiple times. This improves the function of the impact mechanism to strike the filter member. In addition, the operability of the operating member is improved.

According to another feature of the present disclosure, the striking member strikes the actuator by rotating the actuator. Therefore, the actuator can be operated in a more compact space than, for example, a sliding operation.

According to another feature of the present disclosure, the impact mechanism has a cam portion that is displaced in the axial direction by the rotation of the operating member to generate an impact from the striking member. The displacement of the cam portion is synchronized 1:1 with the rotation of the operating member. Therefore, the rotation of the operating member is transmitted to the striking member in 1:1 synchronization without being accelerated by, for example, a gear train. Therefore, the cam portion is displaced by the required amount while suppressing the operating force required for the operating member. As a result, the small-diameter operating member can be rotated with a light force, and the striking member can apply a sufficient impact to the filter member.

According to another feature of the present disclosure, the operating member can rotate in both rotation directions. The striking member strikes the cutting machine body or the dust box in either rotation direction of the operating member. This ensures the operability of the operating member and improves the ease of use of the impact mechanism.

According to another feature of the present disclosure, the dust box has a side that is parallel to the cutting tool. An impact mechanism is provided on the side. Therefore, the impact mechanism can be positioned in a location that does not interfere with work while ensuring operability of the operating member.

1 is an overall perspective view of a portable cutting machine with a dust box according to a first embodiment, as viewed obliquely from the front right side. Fig. 1 is an overall perspective view of a portable cutting machine with a dust box according to a first embodiment, as viewed diagonally from the front left side. Fig. 1 is an overall perspective view of a portable cutting machine with a dust box according to a first embodiment, as viewed diagonally from the rear left side. FIG. 2 is a right side view of the portable cutting machine with a dust box according to the first embodiment. FIG. 2 is a top view of the portable cutting machine with a dust box according to the first embodiment. FIG. 2 is a front view of the portable cutting machine with a dust box according to the first embodiment. FIG. 2 is a rear view of the portable cutting machine with a dust box according to the first embodiment. FIG. 2 is a left side view of the portable cutting machine with a dust box according to the first embodiment. Fig. 7 is a cross-sectional view taken along line IX-IX in Fig. 6. In this figure, the dust box is shown in vertical section. Fig. 1 is an overall perspective view of a dust box according to a first embodiment, as viewed diagonally from the front left side. FIG. FIG. 1 is a right side view of a portable cutting machine with a dust box according to a first embodiment of the present invention, in which the dust box is shown in vertical section and the waste disposal lid is shown in an open state. FIG. 1 is an overall perspective view of a portable cutting machine with a dust box according to a first embodiment, as viewed from the rear left side, with the waste disposal lid open. Fig. 11 is an overall perspective view of a portable cutting machine with a dust box according to a second embodiment, as viewed from the front right side. FIG. 11 is a right side view of the portable cutting machine with a dust box according to the second embodiment. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16, showing a vertical cross-sectional view of the impact applying mechanism according to the second embodiment. FIG. 11 is an exploded perspective view of an impact applying mechanism according to a second embodiment. FIG. 4 is a perspective view of a first cam plate alone. FIG.

Next, an embodiment will be described with reference to the attached drawings. As shown in Figs. 1 to 8, in this embodiment, a handheld cutting machine also called a dustproof circular saw is illustrated as an example of a portable cutting machine with a dust box (hereinafter simply referred to as "portable cutting machine 1"). This portable cutting machine 1 is used for cutting siding, masonry boards, and the like, for example, at a construction site of a house. The user is positioned behind the portable cutting machine 1. The cutting process of the workpiece W progresses as the user moves the portable cutting machine 1 forward by performing a movement operation. In the following description, the direction in which cutting progresses for each of the members and configurations is referred to as the front side, and the side where the user is located is referred to as the rear side. The left and right directions are based on the user.

The portable cutting machine 1 comprises a rectangular flat base 10 that is brought into contact with the top surface of the workpiece W, and a cutting machine body 20 supported on the top side of the base 10. A dust box 50 for collecting dust is attached to the right side of the cutting machine body 20. The cutting machine body 20 comprises a circular cutting tool 22, called a chip saw, that is rotated by an electric motor 21. The periphery of the upper side of the cutting tool 22 is covered by a cutting tool cover 23. The lower side of the cutting tool 22 protrudes from the underside of the base 10. The lower side of the cutting tool 22 is covered by a movable cover 26 that can be opened and closed. The movable cover 26 is provided so as to be able to appear and disappear from the cutting tool cover 23 so as to move between a position covering the lower region of the cutting tool 22 and a position exposing it.

As shown in Figures 4, 9, and 13, the movable cover 26 is biased in the closing direction by the tension spring 26a. When the portable cutting machine 1 is moved forward with the movable cover 26 in contact with the workpiece W, the movable cover 26 rotates relatively clockwise in Figure 4 and opens. The movable cover 26 opens against the tension spring 26a, exposing the cutting tool 22. The exposed part of the cutting tool 22 cuts into the workpiece W to perform the cutting process.

The cutting tool 22 rotates counterclockwise in FIG. 4. The direction of rotation of the cutting tool 22 is indicated by an arrow 50f displayed on the right side of the dust box 50 in FIGS. 1 and 4. The front end of the exposed part of the cutting tool 22 protruding from the underside of the base 10 cuts into the workpiece W to perform the cutting process. The part where the front end of the cutting tool 22 cuts into the workpiece W becomes the cutting area C. Cutting powder is blown upward from the cutting area C. The blown cutting powder is collected in the dust box 50. Details of the dust box 50 will be described later.

The motor housing 25 is connected to the left side of the cutting tool cover 23 via the gear housing 24. The gear housing 24 and the cutting tool cover 23 are integrated with screws. Although not shown in the figure, the gear housing 24 is equipped with a gear train for reducing the rotational output of the electric motor 21. The gear train uses a two-stage reduction gear train of spur gears.

The motor housing 25 is screwed to the left end of the gear housing 24. The electric motor 21 is housed inside the motor housing 25. A DC brushless motor is used for the electric motor 21. The motor axis (axis of the output shaft) J of the electric motor 21 extends in the left-right direction. The left end face of the motor housing 25 is provided with multiple air intakes 25a for introducing outside air for cooling the motor.

The rotational output of the electric motor 21 is reduced by a reduction gear train and output to the spindle 27 (shown only in Figs. 9 and 13). The spindle 27 protrudes into the cutting tool cover 23. The cutting tool 22 is attached to the protruding portion of the spindle 27. The cutting tool 22 is not shown in Fig. 1. The cutting tool 22 is attached by being sandwiched between the outer flange 28 and the inner flange 29 in the plate thickness direction with a fixing screw 27a fastened to the tip surface of the spindle 27.

The handle section 30 has a standing portion 30a that stands upward near the joint between the gear housing 24 and the motor housing 25. The grip section 30b extends rearward from the top of the standing portion 30a. The handle section 30 has a loop shape in a side view. As shown in FIG. 8, a switch lever 31 for starting the electric motor 21 is provided on the inner periphery of the handle section 30. When the switch lever 31 is pulled with the fingertips of the hand holding the grip section 30b, the electric motor 21 starts and the cutting tool 22 rotates. A lock-off button 32 is provided above the switch lever 31. The switch lever 31 is normally locked and cannot be pulled. By pushing the lock-off button 32 to the left or right, the switch lever 31 is released from the locked state in the off position and can be pulled. This prevents the switch lever 31 from being pulled unintentionally or carelessly.

As shown in Figures 2, 3, and 8, an adapter storage section 33 is provided on the left side of the standing section 30a. A communication adapter 34 for wireless communication is installed inside the adapter storage section 33. The communication adapter 34 performs short-distance wireless communication between the portable cutting machine 1 and other wireless devices. By short-distance wireless communication, for example, a dust collector is started and stopped in conjunction with the start and stop operation of the portable cutting machine 1. This wireless communication function allows the operator to efficiently continue cutting work while maintaining a clean work environment. The communication adapter 34 can be removed from the adapter storage section 33. The removed communication adapter 34 can be used for other compatible power tools.

The rear side of the grip portion 30b is connected to the upper surface of the battery attachment portion 40. A controller housing portion 35 is provided on the rear surface of the motor housing 25. The controller housing portion 35 houses a controller 36 for controlling the operation of the electric motor 21. The control board of the controller 36 is equipped with a control circuit made of a microcomputer that transmits a control signal based on rotor position information detected by the sensor board of the electric motor 21. The control board of the controller 36 is also equipped with a drive circuit made of FETs that switches the current of the electric motor 21 based on the control signal received from the control circuit. The control board of the controller 36 is also equipped with an auto-stop circuit that cuts off the power supply to the electric motor 21 according to the detection result of the state of the battery pack 41 to prevent over-discharge or over-current.

The battery attachment section 40 is provided so as to protrude rearward from the top of the controller housing section 35. One battery pack 41 is attached to the underside of the battery attachment section 40. The battery pack 41 is a lithium ion battery that contains multiple battery cells in a rectangular parallelepiped case, and is of a slide-attached type. As shown in Figures 3, 5, and 7, the battery pack 41 can be attached by sliding it to the right relative to the battery attachment section 40, and removed by sliding it to the left. The removed battery pack 41 can be used repeatedly by charging it with a separately prepared charger. The battery pack 41 can also be removed from the battery attachment section 40 and used as a power source for other power tools.

As shown in FIG. 2, a blower nozzle 42 and a spindle lock lever 43 are provided near the front of the motor housing 25. Motor cooling air is exhausted from the blower nozzle 42. By arranging the blower nozzle 42 near the cooling fan built into the motor housing 25, it is possible to obtain a sufficiently large exhaust air volume and speed. Cutting powder can be blown away by the exhaust of motor cooling air blown out from the blower nozzle 42. The rotation of the spindle 27 can be locked by pushing in the spindle lock lever 43. Locking the spindle 27 facilitates the tightening and loosening of the fixing screw 27a when replacing the cutting tool (replacement of the cutting tool 22).

As shown in Figures 2 and 6, an illumination unit 44 is provided at the front of the gear housing 24, which is in front of the cutting tool cover 23. Light from an LED light source is emitted from the front of the illumination unit 44 toward the fillet line guide unit 11 provided at the front of the base 10. When the switch lever 31 is pulled to start the electric motor 21, the illumination unit 44 is turned on. When the switch lever 31 is no longer pulled to stop the electric motor 21, the illumination unit 44 is turned off. The fillet line guide unit 11 is brightly illuminated by the light from the illumination unit 44, so that fillet line alignment work can be performed efficiently in dark places, etc.

The upper part of the motor housing 25 is provided with legs 37 for touching the ground when the portable cutting machine 1 is in an inverted position with the underside of the base 10 facing upwards, and the legs 37, the upper part of the handle part 30, and the front corners of the base 10 are in contact with the ground, allowing the portable cutting machine 1 to be placed in a stable inverted position. This allows the user to temporarily let go of the portable cutting machine 1 during a break in processing work and place it in a stable position.

As shown in Figures 2, 3, 5 and 7, a hexagonal wrench holder 45 is provided on the top surface of the battery attachment section 40. For example, a hexagonal wrench can be held in the hexagonal wrench holder 45. The hexagonal wrench holder 45 is composed of a section that elastically clamps and holds the body of the hexagonal wrench, and a holding hole into which the tip is inserted and held. The hexagonal wrench is not shown in the figures. By tightening the fixing screw 27a that secures the cutting tool 22 and holding the hexagonal wrench used for loosening work in the hexagonal wrench holder 45, replacement work can be performed quickly without the trouble of searching for the hexagonal wrench when working.

The cutting machine body 20 is supported on the base 10 via the front support part 2 and the rear support part 3 so that it can tilt left and right and swing up and down. The front support part 2 is provided on the front part of the upper surface of the base 10, and the rear support part 3 is provided on the rear part of the upper surface. As shown in Figures 1, 2, 5, and 6, the front angular plate 12 of the front support part 2 is arranged in an upwardly standing state on the front part of the upper surface of the base 10. A front support bracket 13 is connected to the rear surface of the front angular plate 12. The front support bracket 13 is supported so that it can tilt left and right via the left and right tilting support shaft 14 shown in Figures 1 and 6. The front part of the cutting machine body 20 is supported on the front angular plate 12 via the front support bracket 13.

The front of the cutting machine body 20 is supported so that it can tilt left and right via the left and right tilting support shaft 14. As shown in Figures 4, 5, and 7, the rear of the cutting machine body 20 is supported on the base 10 via the rear support part 3. A rear angular plate 18 is provided on the rear part of the upper surface of the base 10 in an upwardly standing state. A rear support bracket 15 is supported on the front surface of the rear angular plate 18. The rear support bracket 15 is supported so that it can tilt left and right via the left and right tilting support shaft 16. The left and right tilting support shaft 16 on the rear side is arranged coaxially with the left and right tilting support shaft 14 on the front side. The cutting machine body 20 is supported so that it can tilt left and right relative to the base 10 via the front and rear left and right tilting support shafts 14, 16.

The left and right tilting positions of the cutting machine body 20 are fixed by tightening the front fixing lever 12a and the rear thumbscrew 15a. By tilting the cutting machine body 20, for example, 45° to the right, a so-called oblique cut is made in which the axis of rotation of the cutting tool 22 intersects with the top surface of the workpiece W at 45°.

The body support 20a provided at the front of the cutting machine body 20 is supported by the front support bracket 13 via the vertical swing support shaft 17. As shown in Figs. 5 and 8, the body support 20a is provided in a state in which it protrudes forward from the front of the gear housing 24. The cutting machine body 20 is supported so as to be able to swing up and down via the vertical swing support shaft 17. By changing the vertical swing position of the cutting machine body 20, the amount of protrusion of the cutting tool 22 toward the underside of the base 10 can be changed. The amount of protrusion of the cutting tool 22 toward the underside of the base 10 corresponds to the cutting depth of the cutting tool 22 into the workpiece W. A mechanism for adjusting the cutting depth is disposed between the base 10 and the rear side of the cutting machine body 20.

As shown in Figures 5 and 7, the rear support bracket 15 supports an arc-shaped depth guide 15b via a swinging support shaft 15e so that it can swing up and down. The depth guide 15b is arranged to extend upward and diagonally forward along the left side of the gear housing 24. A fixing screw 15d is inserted through the depth guide 15b and is screwed into the left wall of the gear housing 24. The vertical swing position of the cutting machine body 20 relative to the depth guide 15b is fixed by operating the fixing lever 15c attached to the fixing screw 15d in the direction in which the fixing screw 15d is tightened. This fixes the cutting depth of the cutting tool 22.

A dust box 50 for collecting dust is provided on the right side of the cutting tool cover 23. The dust box 50 can be removed from the cutting tool cover 23 and the gear housing 24. Figure 10 shows the removed dust box 50 on its own. The dust box 50 is a synthetic resin box with a large-capacity dust collection space inside, and is attached to cover the top, right side, and rear of the cutting tool cover 23.

A thumb screw 51 is provided on the right side 50g of the dust box 50. By rotating the thumb screw 51, the attachment state of the dust box 50 to the gear housing 24 can be locked or unlocked. A connecting shaft 52 is attached to the thumb screw 51. The connecting shaft 52 extends long to the left. As shown in FIG. 10, a male threaded portion 52a provided on the left end of the connecting shaft 52 protrudes from the left side of the dust box 50. A female threaded portion 24a (see FIGS. 9 and 13) is formed on the gear housing 24. By rotating the thumb screw 51, the connecting shaft 52 is rotated around its axis, and the male threaded portion 52a is screwed into the female threaded portion 24a and screwed to the gear housing 24. The connecting shaft 52 is engaged with the gear housing 24, and the dust box 50 is fixed to the gear housing 24. The dust box 50 can be removed from the gear housing 24 (tool cover 23) by rotating the thumbscrew 51 to disengage the connecting shaft 52.

As shown in Figures 4 and 9, a square cylindrical dust collection duct 23a is integrally provided at the front of the cutting tool cover 23. The dust collection duct 23a is open at the top and bottom. The lower part of the dust collection duct 23a reaches above the cutting part C. The cutting dust is blown up into the dust collection duct 23a by the dust collection wind generated by the cutting tool 22 rotating counterclockwise in Figure 4. The cutting dust blown into the dust collection duct 23a is collected in the dust box 50.

A dust collection port 53 is provided at the front of the dust box 50, to which the upper part of the dust collection duct 23a is connected. By connecting the dust collection port 53 to the dust collection duct 23a, mainly the front side of the dust box 50 is connected to the cutting tool cover 23 side. The inside of the dust box 50 has a large-capacity dust collection space. It is designed to accommodate a large amount of cutting powder that flows in through the dust collection port 53.

An auxiliary dust collection port 59 is provided behind the dust collection port 53. The auxiliary dust collection port 59 is arranged in the movable area of the movable cover 26. The cutting process is performed with the movable cover 26 in an open or fully open state. The movable cover 26 enters between the peripheral wall of the cutting tool cover 23 and the cutting tool 22 and is opened or fully opened. For this reason, during cutting, the cutting dust blown up from the dust collection port 53 to the rear is likely to accumulate on the upper surface (outer surface) of the movable cover 26 that has entered the inner peripheral side of the cutting tool cover 23. In this way, the cutting dust accumulated between the cutting tool cover 23 and the movable cover 26 behind the dust collection port 53 is collected in the dust box 50 through the auxiliary dust collection port 59. The cutting dust accumulated on the movable cover 26 is blown up to the auxiliary dust collection port 59 by the dust collection wind generated by the rotation of the cutting tool 22. In addition, the cutting dust blown up into the auxiliary dust collection port 59 is collected in the dust box 50 by the suction action of the dust collection airflow (arrow (A)) flowing in from the dust collection port 53. This further improves the dust collection efficiency of the dust box 50.

A guide portion 50d is provided at the downstream end of the auxiliary dust collection port 59 to guide the incoming dust collection air toward the ventilation opening 54. The dust collection air that flows in from the dust collection port 53 and the auxiliary dust collection port 59 is guided by the guide portion 50d toward the ventilation opening 54. The flow of the dust collection air that flows in through the dust collection port 53 and the auxiliary dust collection port 59 is indicated by the arrow (A) in FIG. 9.

The upper part of the dust box 50 is provided with an arc-shaped peripheral wall 50a that follows the periphery of the cutting tool 22. The peripheral wall 50a corresponds to the top plate of the dust box 50, and is provided in the area extending from the front to the rear. The peripheral wall 50a is provided with a rectangular ventilation opening 54. The ventilation opening 54 is provided in a long area that spans from the front to the rear, with the top part (highest part) of the peripheral wall 50a as the boundary. The ventilation opening 54 is provided with a large width in the left-right width direction of the peripheral wall 50a.

The flow of dust-collecting wind indicated by the arrow (A) in FIG. 9 is blown against the ventilation opening 54. The ventilation opening 54 is provided in an area where the wind pressure of the dust-collecting wind flowing in from the dust collection port 53 is the highest. Therefore, most of the dust-collecting wind is exhausted directly to the outside through the ventilation opening 54. This effectively suppresses the rise in internal pressure of the dust box 50.

The ventilation opening 54 is covered with a filter member 55 for removing cutting powder. The filter member 55 is shown alone in Figure 11. The filter member 55 is a so-called pleated filter, and has a bellows shape with repeated mountain and valley folds at numerous folds 55a. The filter member 55 has a roughly rectangular parallelepiped shape overall. The filter members 55 are attached with the numerous folds 55a oriented along the left-right direction (the plate thickness direction of the cutting tool 22) and arranged parallel to each other in the front-rear direction. This gives the filter member 55 flexibility to be bent up and down (in the radial direction of the cutting tool 22).

The filter member 55 is housed in a case body 56. As shown in Figures 9 and 10, the case body 56 is curved in a gentle arc along the peripheral wall 50a of the dust box 50 (the cutting edge of the cutting tool 22) in a side view. The housed filter member 55 is also curved in a gentle arc following the curve of the case body 56.

Figure 12 shows the filter member 55 alone housed in the case body 56. Figure 12 shows the filter member 55 as viewed from the bottom side (inside the dust box 50). A rectangular, large opening window 56a is provided on the bottom surface of the case body 56. Through the window 56a, almost the entire bottom surface of the filter member 55 faces the inside of the dust box 50 via the ventilation opening 54. The filter member 55 is glued to the case body 56 and held in place to prevent it from falling off.

As shown in FIG. 10, a number of ventilation holes 56b are formed on the upper surface (first wall 56e) of the case body 56. The multiple ventilation holes 56b are connected to the inside of the dust box 50 via the window portion 56a and the ventilation opening 54. A pair of left and right arms 56c are provided at the front of the case body 56. A mountain-shaped connecting protrusion 50b is provided on the front upper surface of the peripheral wall 50a of the dust box 50. The connecting protrusion 50b is positioned between the left and right arms 56c, and one connecting shaft 56d is press-fitted into the three. This allows the front of the case body 56 to be connected to the peripheral wall 50a of the dust box 50 without any rattling.

A cylindrical body 56g is integrally provided at the rear of the case body 56, extending in the left-right width direction. The cylindrical body 56g is screwed to the rear of the peripheral wall 50a of the dust box 50 with a single fixing screw 56h. The rear of the case body 56 is connected to the dust box 50 side by screwing with the fixing screw 56h. The case body 56 is provided with left and right second walls 56f that are perpendicular to the first wall 56e. The second walls 56f correspond to the side walls of the case body 56.

The impact mechanism 60 is disposed on the second wall 56f on the left side. In the first embodiment, a long strip-shaped spring plate (leaf spring) is exemplified as the impact mechanism 60. The rear part (second end) of the impact mechanism 60 is screwed to the second wall 56f with a fixing screw 61. The front part (first end) of the impact mechanism 60 is bent toward the side away from the second wall 56f, and a finger hook 60a (operating member) is provided. The user can hook a finger on the finger hook 60a and elastically deform the impact mechanism 60 in a direction away from the second wall 56f (rotate in the lifting direction), and then release the fingertip to flip it. The bounced impact mechanism 60 rotates due to its elastic force and elastically collides with the second wall 56f. This applies an impact to the case body 56.

In the first embodiment, one leaf spring (impact mechanism 60) serves as both the operating member, the elastic member, and the striking member. When an impact is applied to the case body 56, an impact is applied to the filter member 55 itself, and cutting powder that has been removed from the dust-collecting air and adhered to the filter member 55 is shaken off. This clears clogging of the filter member 55. In addition, by applying an operating force to the finger hook portion 60a, which serves as the operating member at the first end, the striking member, which is an elastic member, deforms with the second end (the portion screwed by the fixing screw 61) as a fulcrum. Therefore, the impact mechanism 60 can be elastically deformed with a relatively small force by utilizing the principle of leverage.

The impact mechanism 60 according to the first embodiment is provided on the second wall 56f on the left side of the case body 56. The impact mechanism 60 has an elongated shape that fits along the handle portion 30, and the finger hook 60a at its front is disposed diagonally forward and to the right of the switch lever 31 of the handle portion 30. For this reason, as shown in Figures 2, 3, 5, and 14, the finger hook 60a of the impact mechanism 60 is disposed at a position where it can be easily played and operated by stretching out the fingertips of the hand holding the grip portion 30b. This ensures good operability of the impact mechanism 60.

As shown by the arrow (A) in FIG. 9, the cutting dust is blown onto the filter member 55 by the dust collection wind. The cutting dust is removed by the filter member 55, and clean air is exhausted from the ventilation hole 56b. The cutting dust removed from the dust collection wind by the filter member 55 and the cutting dust shaken off by the impact mechanism 60 fall downward as shown by the arrows (B) and (C) in FIG. 9. A cutting dust storage section 50c is provided at the bottom of the dust box 50. A waste storage section 50e is provided behind the cutting dust storage section 50c. A backflow prevention wall 50r is provided in front (upstream side) of the cutting dust storage section 50c so as to protrude upward. The backflow prevention wall 50r prevents the cutting dust stored in the cutting dust storage section 50c and the waste storage section 50e from flowing back forward. The front side of the backflow prevention wall 50r functions as the guide section 50d described above.

At the rear of the dust box 50, a waste port 65 is provided for discharging the stored cutting dust. The waste port 65 is opened and closed by a lid 66. The lid 66 is supported so as to be rotatable up and down via an opening and closing shaft 67. The waste port 65 is opened by rotating the lid 66 upward. By opening the waste port 65, the cutting dust collected in the dust box 50 can be disposed of. The waste port 65 is closed by rotating the lid 66 downward. At the bottom of the lid 66, a claw portion 66a is provided for maintaining the closed state. The claw portion 66a is elastically hooked onto an engagement recess 65a provided below the waste port 65, thereby maintaining the closed state of the lid 66. This prevents the lid 66 from being inadvertently opened due to an impact or the like.

The lid 66 is provided with a cylindrical connection port 68 for connecting a dust collection hose. The connection port 68 is closed with a cap 69. By removing the cap 69, a dust collector can be connected to the connection port 68 via a dust collection hose. The dust collector can be started and stopped in conjunction with the portable cutting machine 1 by the wireless communication function described above. Cutting dust generated at the cutting site C is not accumulated in the dust box 50, but is collected by the dust collector as it is. By closing the connection port 68 with the cap 69, a large amount of cutting dust can be temporarily collected in the dust box 50, mainly in the cutting dust storage section 50c and the waste storage section 50e. The collected cutting dust is discarded from the waste port 65.

According to the portable cutting machine 1 described above, the dust box 50 has a peripheral wall 50a that runs along the periphery of the cutting tool 22. A ventilation opening 54 is formed at the top of the peripheral wall 50a, in the area where the wind pressure of the dust collection wind is highest. This efficiently suppresses the rise in the internal pressure of the dust box 50. In addition, a filter member 55 is attached to the ventilation opening 54. This ensures that cutting powder is removed from the dust collection wind, and the air is exhausted from the ventilation opening 56b in a clean state. This also maintains the high dust collection efficiency of the dust box 50.

In addition, the impact mechanism 60 applies an impact to the filter member 55 via the case body 56. This prevents clogging of the filter member 55. Preventing clogging of the filter member 55 suppresses an increase in the airflow resistance of the filter member 55. This suppresses an increase in the airflow resistance of the ventilation opening 54 and the ventilation hole 56b, and suppresses an increase in the internal pressure of the dust box 50. By suppressing an increase in internal pressure, the flow of dust collection air containing cutting powder into the dust box 50 is smooth, maintaining high dust collection efficiency.

The impact mechanism 60 according to the first embodiment uses one leaf spring. An operating member (finger hook 60a), an elastic member, and a striking member are integrally provided on one leaf spring. This allows for a simple and compact configuration that can reliably apply an impact to the filter member 55.

The impact mechanism 60 is operated by hooking a fingertip on the finger hook 60a and rotating it sideways against the elastic force, and then removing the fingertip from the finger hook 60a and flicking it, which causes the elastic force to strike the second wall 56f of the case body 56. This simple operation can impact the filter member 55 and shake off the cutting powder, ensuring high operability of the impact mechanism 60.

In addition, the impact mechanism 60 strikes the second wall 56f of the case body 56 located along the left side of the filter member 55 to apply an impact, so that the impact is applied almost directly to the filter member 55, and cutting powder is efficiently shaken off, preventing clogging.

The dust box 50 is provided on the right side along the front-rear direction in which the handle section 30 extends. The impact mechanism 60 is disposed between the handle section 30 and the dust box 50. As a result, the finger hook 60a of the impact mechanism 60 is compactly arranged, effectively utilizing dead space that does not interfere with work.

Furthermore, the finger hook 60a of the impact mechanism 60 is disposed forward of the switch lever 31 of the handle portion 30. This allows, for example, the index finger of a person who pulls the switch lever 31 to be extended and hooked on the finger hook 60a. This ensures the operability of both the switch lever 31 and the impact mechanism 60. Furthermore, for example, while holding the grip portion 30b with one hand to operate the switch lever 31, the other hand can be rotated forward and hooked on the finger hook 60a to operate the impact mechanism 60. By displacing the operating members of the switch lever 31 and the impact mechanism 60 back and forth, one hand does not get in the way of operation by the other hand.

The dust box 50 further has a cutting dust storage section 50c and a waste storage section 50e that extend from the lower region of the ventilation opening 54 to the rear region of the lower region and have a space for storing cutting dust. The dust collection efficiency of the dust box 50 is maintained by storing cutting dust that has been separated and removed from the dust collection wind by the filter member 55 and fallen in the cutting dust storage section 50c and the waste storage section 50e.

In addition, according to the portable cutting machine 1 of the illustrated first embodiment, a backflow prevention wall 50r is provided upstream of the cutting powder storage section 50c to prevent the stored cutting powder from flowing back. The backflow prevention wall 50r prevents the cutting powder from flowing back, maintaining the storage function of the cutting powder storage section 50c and thus the dust collection efficiency of the dust box 50.

The filter member 55 is a pleated filter having many parallel folds 55a. The filter member 55 is attached so that the folds 55a are aligned along the thickness direction (left-right direction) of the cutting tool 22. This allows the filter member 55 to be flexible in the radial direction of the cutting tool 22. This allows the filter member 55 to be curved in an arc shape around the cutting tool 22, allowing for efficient and compact arrangement.

An auxiliary dust collection port 59 is provided behind the dust collection port 53 of the dust box 50. Cutting dust blown backward from the dust collection duct 23a or cutting dust leaking backward from the dust collection port 53 tends to accumulate on the upper surface (outer peripheral surface) of the movable cover 26 that is fully opened during cutting processing. In this way, cutting dust accumulated between the cutting tool cover 23 and the movable cover 26 behind the dust collection port 53 is collected into the dust box 50 via the auxiliary dust collection port 59. This further improves the dust collection efficiency of the dust box 50.

Various modifications can be made to the embodiment described above. For example, although a configuration in which a single leaf spring is placed on the second wall 56f of the case body 56 as the impact mechanism 60 has been exemplified, a dial-operated impact mechanism 70, which will be described below, can be used instead.

Figures 15 and onwards show the impact mechanism 70 according to the second embodiment. The second embodiment differs from the first embodiment in terms of the impact mechanism 70. As no changes are required to the basic configuration of the cutting machine body 20 and the dust box 50, the same reference numerals are used and their explanations are omitted.

Like the impact imparting mechanism 60 according to the first embodiment, the impact imparting mechanism 70 according to the second embodiment also has the function of imparting an impact to the filter member 55 to prevent clogging. As shown in Figures 15 and 16, the impact imparting mechanism 70 according to the second embodiment is disposed on the right side 50g of the dust box 50. Details of the impact imparting mechanism 70 are shown in Figures 17 and 18. The impact imparting mechanism 70 has a disk-shaped operating member 71 and a cam portion 72.

The operating member 71 is rotatably supported on the right side 50g of the dust box 50 via a support shaft 73 having a screw shaft portion 73a. The outer peripheral surface of the operating member 71 is formed with uneven portions 71a for preventing slipping. A cylindrical support shaft portion 71c is integrally provided at the center of the operating member 71. A hexagonal engagement shaft portion 71d is coaxially provided at the left end of the support shaft portion 71c. An insertion hole 71b is provided along the center of the support shaft portion 71c and the engagement shaft portion 71d. The support shaft 73 is inserted into the insertion hole 71b. As shown in FIG. 18, a circular base portion 50h is provided on the right side 50g of the dust box 50. A support hole 50i is provided at the center of the base portion 50h. Anti-rotation protrusions 50j are provided at four locations along the periphery of the base portion 50h.

The threaded shaft portion 73a of the support shaft 73 is inserted into the support hole 50i of the dust box 50. A fixing nut 74 is fastened to the threaded shaft portion 73a inside the right side portion 50g of the dust box 50, and the support shaft 73 is fixed in a state where it protrudes to the right on the right side portion 50g. The operating member 71 is rotatably supported on the right side portion 50g via the support shaft 73. Washers 74a, 74b are respectively interposed between the fixing nut 74 and the right side portion 50g, and between the support shaft portion 71c and the right side portion 50g.

A cam portion 72 is interposed between the operating member 71 and the base portion 50h of the dust box 50. The cam portion 72 has a first cam plate 75, a second cam plate 76, and a compression spring 77. The first cam plate 75 and the second cam plate 76 are shown separately in Figs. 19 and 20. The first cam plate 75 and the second cam plate 76 are each disk-shaped. The first cam plate 75 and the second cam plate 76 have meshing teeth 75a and 76a on their opposing surfaces. As shown in Fig. 19, a hexagonal engagement hole 75b is provided in the center of the first cam plate 75. As shown in Fig. 17, an engagement shaft portion 71d is inserted into the engagement hole 75b, and the first cam plate 75 is integrated with the operating member 71 in terms of rotation.

As shown in FIG. 20, a circular support hole 76b is provided in the center of the second cam plate 76. As shown in FIG. 17, a support shaft portion 71c is inserted into the support hole 76b, and the second cam plate 76 is supported so as to be rotatable and displaceable in the axial direction relative to the operating member 71. In addition, anti-rotation recesses 76c are provided at four equal positions in the circumferential direction on the left surface of the second cam plate 76. Anti-rotation protrusions 50j provided on the right side portion 50g of the dust box 50 enter each of the anti-rotation recesses 76c. This prevents the second cam plate 76 from rotating while allowing it to move toward and away from the right side portion 50g (left and right direction).

A compression spring 77 is interposed between the second cam plate 76 and the operating member 71. The right end of the compression spring 77 is pressed against the operating member 71 via a washer 78. The second cam plate 76 is pressed against the first cam plate 75 by the biasing force of the compression spring 77. The first cam plate 75 is pressed against the base portion 50h by the pressing force of the compression spring 77 of the second cam plate 76. The first cam plate 75 is in sliding contact with the base portion 50h via a washer 75c so as to be relatively rotatable. The second cam plate 76 is pressed against the right side portion 50g via a washer 76d.

When the operating member 71 is rotated, the first cam plate 75 rotates integrally. The first cam plate 75 rotates by displacing the second cam plate 76 to the right against the biasing force of the compression spring 77 while shifting the mutual meshing positions of the meshing teeth 75a, 76a by one position. The second cam plate 76 displaced to the right is displaced to the left by the biasing force of the compression spring 77 so that the meshing teeth 75a, 76a mesh with each other. The second cam plate 76 is displaced to the left by the biasing force of the compression spring 77 and collides with the first cam plate 75, applying an impact to the right side portion 50g of the dust box 50.

When the operating member 71 is rotated in either direction, the meshing position of the meshing teeth 75a of the first cam plate 75 and the meshing teeth 76a of the second cam plate 76 shifts, causing an impact on the second cam plate 76. A single shift (one impact operation) between the meshing positions of the meshing teeth 75a of the first cam plate 75 and the meshing teeth 76a of the second cam plate 76 is achieved by slightly rotating the operating member 71 in either direction. Therefore, by rotating the operating member 71 in either direction at a larger angle, the second cam plate 76 can be displaced multiple times, allowing multiple successive impact operations to be performed. The second cam plate 76 corresponds to the impact member, and the compression spring 77 corresponds to an elastic member that elastically biases the impact member in the impact direction.

When the second cam plate 76 strikes the first cam plate 75, an impact is applied to the right side 50g of the dust box 50. The impact applied to the right side 50g shakes off the cutting powder that has adhered to the filter member 55 attached to the ventilation opening 54 of the dust box 50. The impact also shakes off the cutting powder that has adhered to the inner wall of the dust box 50 and accumulates in the cutting powder storage section 50c or waste storage section 50e.

After one or more strikes are applied by rotating the operating member 71, there is no need to return the operating member 71 to a specific initial position. The operating member 71 can be rotated from any position. This ensures high operability.

According to the impact mechanism 70 of the second embodiment configured as described above, as in the first embodiment, the ventilation opening 54 for reducing the internal pressure of the dust box 50 is provided in the area spanning the top of the peripheral wall 50a, and the rise in internal pressure is efficiently suppressed. Moreover, a filter member 55 is attached to the ventilation opening 54 to prevent leakage of cutting powder. Furthermore, according to the second embodiment, an impact can be applied to the filter member 55 by rotating the operating member 71, preventing clogging. This maintains the breathability of the ventilation opening 54 and the ventilation port 56b, and suppresses the rise in internal pressure of the dust box 50.

According to the impact mechanism 70 of the second embodiment, multiple impact operations can be generated by rotating the operating member 71 only once at a large angle. This ensures that cutting powder is shaken off from the filter member 55 and its surrounding areas. Since an impact can be applied by rotating the disk-shaped operating member 71, good operability is ensured in a more compact space than, for example, a sliding operation.

The impact mechanism 70 according to the second embodiment has a cam portion 72 that generates an impact by displacing the second cam plate 76 in the axial direction when the operating member 71 is rotated, thereby striking the first cam plate 75. The displacement of the second cam plate 76 is synchronized 1:1 with the rotation of the operating member 71. Therefore, the rotation of the operating member 71 is transmitted to the cam portion 72 in 1:1 synchronization without being accelerated by, for example, a gear train. Therefore, the first cam plate 75 can be rotated to displace the second cam plate 76 a sufficient distance in the axial direction while suppressing the operating force required for the rotation of the operating member 71. As a result, the small-diameter operating member 71 can be rotated with a light force, and a sufficient impact can be applied to the filter member 55 by the strike of the cam portion 72.

The operating member 71 can rotate in both directions, and can generate an impact with the cam portion 72 in either direction. Furthermore, depending on the amount of rotation of the operating member 71, it is possible to apply a single impact or multiple impacts continuously, and the number of strikes can be freely changed. In this respect, good operability of the operating member 71 is ensured, and the usability of the impact application mechanism 70 is improved.

The impact mechanism 70 according to the second embodiment is provided on the right side 50g of the dust box 50, ensuring operability of the operating member 71 while being positioned so as not to interfere with the cutting operation.

The first and second embodiments described above can be further modified. For example, the impact mechanism 60 according to the first embodiment is disposed on the second wall 56f on the left side of the case body 56 that houses the filter member 55, but it may be disposed on the second wall 56f or the first wall 56e on the right side. It may be disposed on the peripheral wall 50a or the right side 50g of the dust box 50 or other parts, not limited to the case body 56. The impact mechanism 60 in the form of a leaf spring may be disposed on the cutting machine body 20 side (particularly the blade cover 23). The same applies to the impact mechanism 70 according to the second embodiment, and it may be disposed on the peripheral wall 50a or the left side of the dust box 50, or the blade cover 23, not limited to the right side 50g as exemplified.

The impact mechanism 60 according to the first embodiment may be configured so that the rear side is a finger hook (operating member) and the front side is screwed to the second wall 56f with a fixing screw.

In the above example, the ventilation openings 54 are provided in an area that spans the front and rear of the zenith (highest part) of the peripheral wall 50a, but they may also be located in an area that includes the zenith and is shifted forward, or in an area that includes the zenith and is shifted backward.

The ventilation openings may be located in the front or rear area outside the top of the peripheral wall 50a, and may be located in multiple separate locations instead of just one. A filter member held by the case body may be arranged for multiple ventilation openings, and a leaf spring type impact mechanism 60 may be arranged on each case body.

The configuration in which the front part of the case body 56 that holds the filter member 55 is connected to the peripheral wall 50a of the dust box 50 via the connecting shaft 56d has been exemplified, but it may also be configured to be connected by screwing in the same manner as the rear side. Also, the case body 56 may be configured to be connected to the peripheral wall 50a by adhesive.

The filter member 55 shown in the example is a pleated filter having a bellows shape with multiple folds 55a, but a sheet-type filter may also be used.

The impact mechanism 70 according to the second embodiment is configured such that the rotation of the operating member 71 is directly transmitted to the first cam plate 75 in a 1:1 ratio, but it may also be configured such that the rotation of the operating member is accelerated or decelerated by using a planetary gear train or the like before being transmitted to the cam section.

The portable cutting machine with dust box 1 can be used not only for dustproof circular saws that use circular saw blades such as tipped saws as cutting tools, but also for cutters that use diamond wheels as cutting tools.

1...portable cutting machine 2...front support part 3...rear support part W...workpiece C...cutting area 10...base 11...slit line guide part 12...front angular plate, 12a...fixed lever 13...front support bracket 14...left-right tilting shaft 15...rear support bracket 15a...knob screw, 15b...depth guide, 15c...fixed lever, 15d...fixed screw 15e...swinging shaft 16...left-right tilting shaft 17...up-down swinging shaft 18...rear Angular plate 20...cutting machine body, 20a...body support portion 21...electric motor J...motor shaft 22...cutting tool 23...cutting tool cover, 23a...dust collection duct 24...gear housing, 24a...female thread portion 25...motor housing, 25a...air intake 26...movable cover, 26a...tension spring 27...spindle, 27a...fixing screw 28...outer flange 29...inner flange 30...handle portion 30a...standing portion, 30b...grip portion 31...switch lever 32...lock-off button 33...adapter housing portion 34...communication adapter 35...controller housing portion 36...controller 37...leg portion 40...battery attachment portion 41...battery pack 42...blower nozzle 43...spindle lock lever 44...illumination portion 45...hexagonal wrench holding portion 50...dust box 50a...peripheral wall, 50b...connection protrusion, 50c...cutting powder storage Retaining portion, 50d...guide portion 50e...waste storage portion, 50f...arrow marking, 50g...right side portion, 50h...base portion 50i...support hole, 50j...rotation prevention protrusion, 50r...backflow prevention wall 51...knob screw 52...connecting shaft, 52a...male thread portion 53...dust collection port 54...ventilation opening 55...filter member (filter), 55a...fold 56...case body 56a...window portion, 56b...ventilation port, 56c...arm portion, 56d...connecting shaft, 56e...first wall (upper surface)
56f: second wall (side surface), 56g: cylindrical body portion, 56h: fixing screw 59: auxiliary dust collection port 60: impact applying mechanism (first embodiment)
60a... Finger hook portion (operation member)
61: Fixing screw 65: Disposal port, 65a: Engagement recess 66: Lid, 66a: Claw portion 67: Opening/closing shaft 68: Connection port 69: Cap 70: Impact applying mechanism (second embodiment)
71...operating member 71a...concave and recessed portion, 71b...insertion hole, 71c...support shaft portion, 71d...engagement shaft portion 72...cam portion 73...support shaft, 73a...screw shaft portion 74...fixing nut, 74a, 74b...washer 75...first cam plate 75a...engagement teeth, 75b...engagement hole, 75c...washer 76...second cam plate 76a...engagement teeth, 76b...support hole, 76c...rotation prevention recess, 76d...washer 77...compression spring 78...washer

Claims (10)

A portable cutting machine with a dust box,
A cutting machine body that houses an electric motor;
a blade cover for covering a blade rotated by the electric motor;
A dust box is provided adjacent to the cutting tool cover to collect cutting powder;
A filter member covering an air vent opening provided in the dust box;
an impact applying mechanism provided in the cutting machine body or the dust box and configured to apply an impact to the filtering member by a user's operation;
The impact mechanism includes an operating member that is operated by a user, an elastic member that is elastically deformed by the operation of the operating member, and a striking member that strikes the cutting machine body or the dust box by utilizing the elastic force of the elastic member,
The striking member is elongated, and the operating member is provided at a first end of the striking member.
The striking member is elastically deformable and serves as the elastic member, and a second end of the striking member is attached to the cutting machine body or the dust box . The portable cutting machine with a dust box according to claim 1 ,
The dust box has a first wall in which the ventilation opening in which the filtering member is attached is formed, and a second wall perpendicular to the first wall, and the impact applying mechanism is disposed in the second wall. The portable cutting machine with a dust box according to claim 1 or 2 ,
The cutting machine body has a handle portion attached to the dust box, and the impact mechanism is disposed between the dust box and the handle portion. A portable cutting machine with a dust box according to any one of claims 1 to 3 ,
The cutting machine body has a handle portion attached to the dust box, and a switch lever for starting and operating the electric motor is provided on the handle portion.The striking member is elongated and extends along the handle portion, and the operating member is located at the tip of the striking member forward of the switch lever.This is a portable cutting machine with a dust box. A portable cutting machine with a dust box,
A cutting machine body that houses an electric motor;
a blade cover for covering a blade rotated by the electric motor;
A dust box is provided adjacent to the cutting tool cover to collect cutting powder;
A filter member covering an air vent opening provided in the dust box;
an impact applying mechanism provided on a side of the dust box parallel to the blade and configured to apply an impact to the filter member by a user's operation;
The impact applying mechanism includes an operating member that is operated by a user to rotate about an axis parallel to the rotation axis of the blade;
An elastic member that is elastically deformed by the rotational operation of the operating member, and a striking member that strikes a side portion of the dust box by utilizing the elastic force of the elastic member;
The portable cutter with a dust box has a cam portion which is displaced in the axial direction by rotating the operating member to generate an impact by the striking member . 6. The portable cutting machine with a dust box according to claim 5 ,
A portable cutting machine with a dust box, in which a single operation of the operating member causes the striking member to strike a plurality of times. The portable cutting machine with a dust box according to claim 5 or 6 ,
The portable cutting machine with a dust box is configured such that the striking member strikes the workpiece by rotating the operating member. A portable cutting machine with a dust box according to any one of claims 5 to 7 ,
A portable cutting machine with a dust box, in which the displacement of the cam portion is synchronized 1:1 with the rotational operation of the operating member. A portable cutting machine with a dust box according to any one of claims 5 to 8 ,
The operating member is rotatable in both directions of rotation, and the striking member strikes the cutting machine body or the dust box in either direction of rotation of the operating member. A portable cutting machine with a dust box according to any one of claims 1 to 9 ,
The striking member is biased in a rotational direction by the elastic member, and strikes the cutting machine body or the dust box by rotation.

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