JP2011131367A - Portable cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable cutter having a higher dust-collecting capability. <P>SOLUTION: A housing 2 is comprised chiefly of a motor compartment 21 and a rotating blade cover 4 covering a portion of a rotating blade 3. A fan 71 for cooling a motor is provided inside the motor compartment 21. A dust box 5 can be detachably attached to the housing 2 and is formed with a dust-collecting opening 51a. The portable cutter 1 further includes a passage 24 open at one end into the motor compartment 21 and at the other end into the rotating blade cover 4 to guide a wind created by rotation of the fan 71 into the rotating blade cover 4. The other end of the passage 24 opens at a position opposite to the dust-collecting opening 51a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a portable cutting machine, and more particularly to a portable cutting machine that collects dust from a cutting blade in a dust box.

  2. Description of the Related Art Conventionally, there is known a portable cutting machine that includes a disk-shaped rotary blade and can cut a workpiece by rotating the rotary blade. Almost half of the rotary blade as the cutting blade of the portable cutting machine is covered with the housing and the inner surface of the first dust cover fixed to the housing, and the inner surface of the first dust cover defines the rotary blade housing space together with the housing. To do. A chip dust collection space is defined by the outer surface of the first dust cover and the second dust cover.

  A dust collection port is formed near the end of the first dust cover on the front side in the cutting direction. The dust collection port penetrates the first dust cover so as to communicate the rotary blade housing space and the chip dust collection space. The chips generated by cutting the workpiece with the rotary blade can be collected into the chip dust collection space through the dust collection port by the air flow generated by the rotation of the rotary blade. Such a portable cutting machine is described in, for example, JP-A-8-300307 (Patent Document 1).

JP-A-8-300307

  However, in the above-described portable cutting machine, the dust collection capability is not sufficient and a higher dust collection capability is required.

  Then, an object of this invention is to provide the portable cutting machine which has higher dust collection capability.

  To achieve the above object, the present invention provides a housing having a motor housing portion and a rotary blade cover, a motor housed in the motor housing portion, and a fan housed in the motor housing portion for cooling the motor. A rotary blade that is driven by the motor and partially covered by the rotary blade cover; and a dust box that is detachably provided in the housing and has a dust collection port that communicates with the rotary blade cover. One end opened in the motor housing and the other end opened in the rotary blade cover, and has a first passage for guiding the wind generated by the rotation of the fan to the rotary blade cover. A portable cutting machine is provided that is open at a position facing a dust port.

  An opening is formed at a position opposite to the dust collection port, and the wind generated by the rotation of the fan is guided to the opening, so that an air flow from the opening to the dust box through the dust collection port is formed. . By this air flow, chips generated around the rotary blade at the time of cutting can be actively taken into the dust box, and the dust collection efficiency can be improved.

  Moreover, it is preferable that the other end is opened at a position overlapping with at least a part of the blade edge of the rotary blade as viewed from the axial direction of the rotary blade.

  When a part of the opening overlaps with a part of the blade edge of the rotary blade as viewed from the axial direction of the rotary blade, chips attached to the periphery of the blade edge of the rotary blade can be efficiently collected.

  Further, it is preferable that the fan is a centrifugal fan, and the one end is opened outward in the radial direction of the centrifugal fan.

  Since the opening in the motor housing portion is formed radially outward of the centrifugal fan, wind generated by the rotation of the fan can be efficiently guided to the first passage. Thereby, chips generated around the rotary blade during cutting can be actively taken into the dust box, and dust collection efficiency can be improved.

  Further, it is preferable that at least two dust collecting ports are formed, and the other end is opened at a position facing any one of the dust collecting ports.

  At least two dust collection ports are formed in the rotary blade cover, and an opening that communicates with the first passage is provided at a position facing one of the dust collection ports, so that the periphery of the rotary blade at the time of cutting is provided. It is possible to improve the dust collection efficiency by actively taking chips generated in the dust box.

  The dust collecting apparatus further comprises a second passage having one end opened in the first passage and the other end opened in the rotary blade cover and guiding the wind generated by the rotation of the fan to the rotary blade cover. It is preferable that the other end of the first passage is opened at a position facing the opening, and the other end of the second passage is opened at a position facing any one of the other dust collection openings.

  The dust collecting apparatus further includes a third passage having one end opened in the motor housing portion and the other end opened in the rotary blade cover and guiding wind generated by the rotation of the fan to the rotary blade cover. It is preferable that the other end of the first passage is opened at a position facing the opening, and the other end of the third passage is opened at a position facing any one of the other dust collection openings.

  The second passage or the third passage for guiding the wind generated by the motor fan is further formed, and the passage opening and the dust collection port are provided at positions facing each other, so that the dust collection at one dust collection port. Chips that could not be collected can be collected at the other dust collection port. Thereby, chips generated around the rotary blade during cutting can be actively taken into the dust box, and dust collection efficiency can be improved.

  An engagement portion for mounting the dust box to the housing is provided at a substantially central portion of the dust box, and the dust collection port facing the position at which the other end of the first passage opens. One of the dust collection ports facing the position where the other end of the second passage or the third passage opens is formed on the front side in the cutting direction, and the other end of the first passage The other dust collection port of the dust collection port facing the position where the other end of the second passage or the third passage is opened is the engagement port. It is preferable that it is formed on the rear side in the cutting direction from the upper position of the joint.

  As a result, dust can be collected in the dust box on the rear side in the cutting direction without the chips hitting the engaging portion and collecting in the dust box on the one dust collection port side, so that the space in the dust box is effectively used. And the dust collection rate can be improved.

  Further, an engagement portion for mounting the dust box to the housing is provided at a substantially central portion of the dust box, and the space in the dust box is divided into a first dust storage space and a second dust storage space by the engagement portion. And the dust collection port facing the position where the other end of the first passage opens and the dust collection port facing the position where the other end of the second passage or the third passage opens. The dust collecting port of any one of the dust ports is formed in the first dust accommodating space, and the dust collecting port and the second passage or the second passage facing the position where the other end of the first passage opens. It is preferable that the other dust collection port of the dust collection port facing the position where the other end of the third passage opens is formed in the second dust containing space.

  By providing one dust collection port in the first dust storage space and providing the other dust collection port in the second dust storage space, one dust storage space in the dust box defined by the engaging portion is full. Even in the state, chips can be collected in the other dust storage space. Thereby, the space in a dust box can be used effectively.

  Moreover, it is preferable to have a light source that illuminates the periphery of the cut portion of the material to be cut by the rotary blade, and the light source is preferably held on the other end side of the first passage.

  Moreover, it is preferable that the wiring of the light source is disposed in the first passage.

  By arranging the light source and the light source wiring in the first passage for guiding the wind of the fan, heat generation of the light source and the wiring can be suppressed by the wind. Furthermore, since the first passage also serves to hold the light source and the wiring, it is not necessary to newly form a light source holding member, and the number of parts can be reduced.

  The first passage is preferably provided in the housing.

  Since the first passage is provided in the housing, the strength can be improved and the fan wind can be stably guided into the dust box.

  As described above, the present invention can provide a portable cutting machine having a higher dust collection capability.

The side view which shows the portable cutting machine by the 1st Embodiment of this invention. The side view which shows the portable cutting machine by the 1st Embodiment of this invention. The top view which shows the portable cutting machine by the 1st Embodiment of this invention. The side view which shows the dust box of the portable cutting machine by the 1st Embodiment of this invention. The top view which shows the flow of the wind by the centrifugal fan of the portable cutting machine by the 1st Embodiment of this invention. The disassembled perspective view which shows the dust box of the portable cutting machine by the 1st Embodiment of this invention. The perspective view which shows the 1st dust cover of the portable cutting machine by the 1st Embodiment of this invention. The side view which shows the state from which the 2nd dust cover was removed in the portable cutting machine by the 1st Embodiment of this invention. The side view which shows the state from which the dust box was removed in the portable cutting machine by the 1st Embodiment of this invention. The top view which shows the portable cutting machine by the 2nd Embodiment of this invention. The side view which shows the state from which the 2nd dust cover was removed in the portable cutting machine by the 2nd Embodiment of this invention. The side view which shows the state from which the dust box was removed in the portable cutting machine by the 2nd Embodiment of this invention. The side view which shows a mode that it has collected in the dust box of the portable cutting machine by the 2nd Embodiment of this invention. The fragmentary sectional view which shows the channel | path of the portable cutting machine by the 2nd Embodiment of this invention, and a back channel | path. The fragmentary sectional view which shows the channel | path of the portable cutting machine by the modification of the 2nd Embodiment of this invention, and a back channel | path. The fragmentary sectional view which shows the channel | path of the portable cutting machine by the 3rd Embodiment of this invention, and an illuminating device.

  A portable cutting machine according to an embodiment of the present invention will be described with reference to FIGS. A portable circular saw 1 that is a portable cutting machine shown in FIGS. 1 to 3 includes a housing 2, a rotary blade 3, and a base 6. Here, for convenience of explanation, a direction from left to right in FIG. 1 is defined as a cutting direction. The right end side of the portable circular saw 1 shown in FIG. 1 is defined as the front side in the cutting direction, the left end side is defined as the rear side in the cutting direction, and the upper side of the portable circular saw 1 shown in FIG. The lower side of the portable circular saw 1 shown in FIG. 1 is defined as the lower side.

  As shown in FIGS. 1 to 3, the housing 2 includes a gear cover 25, a motor housing portion 21 in which a motor (not shown) is housed and extending from the gear cover 25 in a direction orthogonal to the cutting direction, and the gear cover 25 or the motor housing portion. 21 and a handle 22 connected to 21. A drive system (not shown) including a reduction gear driven by a motor (not shown) is provided in the housing 2. The rotary blade 3 is rotatably supported by the housing 2. The rotation axis of the rotary blade 3 is parallel to the extending direction of the motor housing portion 21, and a blade edge is formed on the outer edge of the rotary blade 3. When the motor (not shown) is driven, the rotary blade 3 is configured to be driven to rotate counterclockwise in FIG. 1 (hereinafter referred to as the rotation direction of the rotary blade 3) via a drive system (not shown). . A passage 24 is formed in the housing 2. The passage 24 is formed on the front side in the cutting direction of the gear cover 25 and at a height substantially the same as that of the motor housing portion 21. One end of the passage 24 opens to the motor accommodating portion 21 and the other end opens to the rotary blade cover 4 described later. That is, the passage 24 communicates the inside of the motor housing portion 21 with the inside of the rotary blade cover 4 described later. The passage 24 functions as an example of the first passage.

  The gear cover 25 is provided with an illumination device 26 for illuminating the cutting edge of the rotary blade 3. The illumination device 26 is located below the passage 24. The illumination device 26 is interlocked with the operation of an off-lock switch 22B described later.

  A plurality of suction ports 21 a are formed on the outer end surface of the motor housing portion 21 in the extending direction. As shown in FIG. 5, a centrifugal fan 71 is provided on the gear cover 25 side in the motor housing portion 21. The centrifugal fan 71 is provided coaxially with an output shaft of a motor (not shown) and functions as a cooling fan for cooling the motor. A motor accommodating portion side opening 21 b is formed on the inner surface of the motor accommodating portion 21 and radially outward of the centrifugal fan 71, and is connected to one end of the passage 24.

  The handle 22 is provided with a switch 22A for controlling driving of a motor (not shown) and an off-lock switch 22B. The switch 22A cannot be turned on (pressed) unless the off-lock switch 22B is pressed. When the off-lock switch 22B is pressed, the lighting device 26 is turned on. A battery 23 for supplying power to a motor (not shown) is detachably provided at the lower portion of the handle 22.

  As shown in FIG. 9, the rotary blade cover 4 is formed integrally with the housing, forms a part of the housing 2, and is provided on the side opposite to the motor accommodating portion 21 with the handle 22 interposed therebetween.

  The rotary blade cover 4 is configured to cover one side surface of the substantially upper half of the rotary blade 3 located above the base 6. A rotary blade cover side opening 4 a is formed on the front side in the cutting direction of the rotary blade cover 4. The rotary blade cover side opening 4 a is formed at a position where at least a part of the rotary blade cover side opening 4 a overlaps the cutting edge of the rotary blade 3 when viewed from the axial direction of the rotary blade 3. The rotary blade cover side opening 4 a is connected to the other end of the passage 24. A connecting portion 41 that is connected to a later-described rotation support portion 62 is provided at the lower portion on the front side in the cutting direction of the rotary blade cover 4.

  The rotary blade cover 4 is provided with a safety cover 42 that covers most of the cutting edge of the rotary blade 3 protruding from the lower surface of the base 6. The safety cover 42 can be rotated along the outer edge of the rotary blade 3 around the rotation axis of the rotary blade 3. A spring (not shown) is interposed between the rotary blade cover 4 and the safety cover 42, and the spring (not shown) attaches the safety cover 42 to the rotary blade cover 4 in the rotation direction of the rotary blade 3. It is fast.

  When the cutting operation is not performed, as shown in FIG. 1, the safety cover 42 covers most of the cutting edge protruding downward from the base 6 except for a part on the front side in the cutting direction. On the other hand, a portion where the rotary blade 3 is exposed is formed between the base 6 and the safety cover 42. This portion is a cutting position for cutting the wood as the workpiece, and the portable circular saw 1 is cut forward toward the front side in the cutting direction. When the workpiece is brought into contact with the front end of the safety cover 42 in the cutting direction, the safety cover 42 rotates counterclockwise around the rotation axis of the rotary blade 3 and is accommodated in the rotary blade cover 4. .

  A dust box 5 is provided on the opposite side of the rotary blade 3 with respect to the rotary blade cover 4. As shown in FIG. 6, the dust box 5 includes a first dust cover 51 and a second dust cover 52. The first dust cover 51 is fixed to the rotary blade cover 4. The second dust cover 52 is configured to be detachable from the first dust cover 51. By attaching the second dust cover 52 to the first dust cover 51, the first dust cover 51 and the second dust cover 52 define a chip dust collection space 50 a.

  As shown in FIG. 8, the first dust cover 51 faces the other side surface of the substantially upper half of the rotary blade 3 positioned above the base 6. The first dust cover 51, together with the rotary blade cover 4, defines a rotary blade accommodation space 40 a that accommodates substantially the upper half of the rotary blade 3.

  As shown in FIG. 8, a dust collection port 51 a is formed on the front side in the cutting direction of the first dust cover 51. The dust collection port 51a is formed at a position facing the rotary blade cover side opening 4a. That is, the dust collection port 51 a and the rotary blade cover side opening 4 a are located on a straight line parallel to the rotation axis of the rotary blade 3. The penetration direction of the dust collection port 51a is directed to the rear side in the cutting direction, and allows the rotary blade housing space 40a and the chip dust collection space 50a to communicate with each other. The dust collection port 51a has a substantially oval shape, and has a size such that the dust once collected in the dust collection space 50a hardly goes out to the rotary blade housing space 40a again. Yes.

  Further, as shown in FIGS. 4 and 6, a guide 51 </ b> C is provided in the opening on the chip dust collection space 50 a side of the dust collection port 51 a of the first dust cover 51. The guide 51C guides the chips from the opening of the dust collection port 51a toward the rear side in the cutting direction. Due to the rotation of the rotary blade 3, an air flow in the rotational direction of the rotary blade 3 is generated in the rotary blade accommodating space 40a. In order to smoothly guide this air flow to the rear side in the cutting direction, a guide portion 51C is provided. In addition, as shown in FIG. 4, a plate 51D inclined with respect to the cutting direction is provided below the guide portion 51C, and the dust collected from the dust collection port 51a into the dust collection space 50a is collected. It is configured so that powder does not collect in the vicinity of the dust collection port 51a. Further, an engagement hole 51c in which a female screw is formed is formed at a substantially central portion of the first dust cover 51.

  As shown in FIG. 6, the second dust cover 52 is provided with an engaging portion 52 </ b> C at a substantially central portion thereof. The engaging portion 52C has a substantially cylindrical shape and protrudes into the chip dust collecting space 50a. A through hole 52c is formed at the axial center position of the protruding end of the engaging portion 52C. A headless screw 53 passes through the through hole 52c. One end of the headless screw 53 is screwed into the female screw of the engagement hole 51c of the first dust cover 51, and a butterfly bolt 54 is connected to the other end. It is screwed. The second dust cover 52 is fixed to the first dust cover 51 by tightening the butterfly bolt 54, and the second dust cover 52 can be removed from the first dust cover 51 by loosening the butterfly bolt 54. Has been.

  A connection portion 55 is provided on the rear side in the cutting direction of the second dust cover 52. The connecting portion 55 has a cylindrical mouth portion 55A that can be connected to a hose of a dust collector (not shown) and is inclined upward. The cylindrical mouth portion 55A is closed by a cap 56.

  As shown in FIGS. 1 to 3, the base 6 includes a base member 61, a rotation support portion 62, a bevel plate 64, a guide piece 65, and a cutting depth adjusting mechanism 66. With these configurations, the base 6 supports the housing 2, the rotary blade 3, and the rotary blade cover 4 so as to be rotatable about the rotation support portion 62.

  The base member 61 is made of a substantially rectangular plate made of metal. The base member 61 is arranged so that the longitudinal direction thereof coincides with the cutting direction, and a long hole-like opening (not shown) extending in the longitudinal direction is formed at a substantially central portion thereof. The rotary blade 3 and the safety cover 42 can be inserted through the opening (not shown).

  The bevel plate 64 and the rotation support portion 62 are provided at the end of the base member 61 on the front side in the cutting direction. The bevel plate 64 is provided upright on the base member 61 and includes a tilting shaft portion 64A extending in the cutting direction. The upper portion of the bevel plate 64 has an arc shape centered on the tilting shaft portion 64A, and an arc-shaped long hole (not shown) centered on the tilting shaft portion 64A is formed therein.

  The rotation support portion 62 is pivotally supported by the tilt shaft portion 64A so as to be tiltable at a predetermined angle with respect to the surface of the base member 61 in a direction orthogonal to the cutting direction. The rotation support portion 62 pivotally supports a connecting portion 41A that forms a portion of the rotary blade cover 4 on the front side in the cutting direction.

  The rotation support portion 62 is provided with a screw 62 </ b> B that passes through the long hole (not shown) of the bevel plate 64 and is screwed into a screw hole (not shown) formed in the rotation support portion 62. The entire housing 2 including the rotary blade 3 is moved in the axial direction of the rotary blade 3 by loosening the screw 62B and moving the rotation support portion 62 in a circumferential direction around the tilting shaft portion 64A in a long hole (not shown). Tilt. Thereby, the angle with respect to the axial direction of the rotary blade 3 can be finely adjusted. By tightening the screw 62B, the rotation support portion 62 can be fixed to the bevel plate 64 at an arbitrary tilt angle.

  The guide piece 65 is provided on the extended line of the rotary blade 3 in the cutting direction and at the end of the base 6 on the front side in the cutting direction. The operator can recognize the cutting position of the workpiece by confirming the position of the guide piece 65. Further, a cutting depth adjusting mechanism 66 for changing the amount of protrusion of the rotary blade 3 from the base 6 to the lower side, ie, the cutting depth, is provided. The cut depth adjusting mechanism 66 is provided between the handle 22 and the rotary blade cover 4 and extends upward from the base 6, and is positioned on the side opposite to the rotary blade cover 4 with respect to the handle 22 and engages with the link 67. And an adjusting knob 68 for adjusting the position. The adjustment knob 68 is loosened, the housing 2 is moved up and down along the link 67 around the rotation support portion 62 with respect to the base 6 and adjusted to a desired cutting depth, and then the adjustment knob 68 is tightened to tighten the base. It is possible to adjust the amount of the rotary blade 3 that protrudes downward from 6.

  Next, the operation of the portable circular saw 1 will be described. When the operator depresses the switch 22A while depressing the off-lock switch 22B, the motor (not shown) rotates, and the rotational force is transmitted to the rotary blade 3 via a drive system (not shown). At the same time, the centrifugal fan 71 also rotates, takes in the outside air from the suction port 21a, and introduces the outside air into the motor accommodating portion side opening 21b. That is, an air flow (wind) from the suction port 21a toward the motor accommodating portion side opening 21b is formed. Since only the suction port 21a and the motor housing part side opening 21b are formed in the motor housing part 21, all the outside air sucked by the centrifugal fan 71 passes through the motor housing part side opening 21b to the passage 24. Carried.

  As shown in FIG. 5, the air flowing through the passage 24 is jetted into the rotary blade accommodating space 40a through the rotary blade cover side opening 4a. And it ejects in the chip dust collection space 50a of the dust box 5 through the dust collection port 51a formed in the position facing the rotary blade cover side opening 4a. At this time, as seen from the axial direction of the rotary blade 3, the rotary blade cover side opening 4a is formed so as to partially overlap the blade edge of the rotary blade 3, so that the air jetted into the rotary blade accommodating space 40a Flows into the dust collection space 50a while hitting the cutting edge. At the same time, the air flow in the rotary blade accommodation space 40a generated by the rotation of the rotary blade 3 also flows into the chip dust collection space 50a through the dust collection port 51a.

  The air flowing into the chip dust collection space 50 a is released to the outside through a slight gap between the first dust cover 51 and the second dust cover 52. The gap has such a gap that the chips in the chip dust collection space 50a do not leak out.

  In this state, when the worker cuts the workpiece, the chips are carried upward from the cut portion on the airflow generated by the rotation of the rotary blade 3. Then, the dust is collected in the dust collection space 50 a in the dust box 5 through the dust collection port 51 a located above the cut portion. At this time, since the air flow from the rotary blade cover side opening 4a toward the dust collection port 51a is formed around the dust collection port 51a as described above, chips are actively taken into the dust collection port 51a. It is. Furthermore, when a part of the air ejected from the rotary blade cover side opening 4a hits the blade edge of the rotary blade 3, chips adhering to the vicinity of the blade edge can be removed.

  The operator turns off the switch 22 to cut off the power supply from the battery 23 to the motor, and stops the rotation of the rotary blade 3. Along with this, the centrifugal fan 71 is also stopped, and the flow of air from the motor housing portion 21 via the passage 24 to the dust box 5 is also stopped.

  The rotary blade cover side opening 4a is provided at a position facing the dust collection port 51a, and the wind generated by the rotation of the centrifugal fan 71 is guided to the opening, so that the dust collection port 51a is moved from the rotary blade cover side opening 4a. An air flow toward the inside of the dust box 5 is formed. By this air flow, chips generated around the rotary blade 3 during cutting can be actively taken into the dust box 5 to improve dust collection efficiency. Specifically, the dust collection rate, which was about 40% in the past, can be improved to about 50%. The dust collection rate here refers to the proportion of the generated chips that can be collected.

  As seen from the axial direction of the rotary blade 3, a part of the rotary blade cover side opening 4 a overlaps a part of the blade edge of the rotary blade 3, thereby efficiently removing chips adhering to the blade edge of the rotary blade 3. Can collect dust.

  Since the motor accommodating portion side opening 21b is formed radially outward of the centrifugal fan 71, the wind generated by the rotation of the centrifugal fan 71 can be efficiently guided into the passage 24. As a result, chips generated around the rotary blade 3 during cutting can be actively taken into the dust box 5 to improve dust collection efficiency.

  Since the passage 24 is provided in the housing 2, the strength can be improved and the wind of the centrifugal fan 71 can be stably guided into the dust box 5.

  Next, a portable circular saw 201 according to the second embodiment will be described with reference to FIGS. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  In the second embodiment, as shown in FIGS. 10 and 14, a rear passage 224 communicating with the passage 24 is formed in the housing 2. One end of the rear passage 224 is connected to a passage side opening 224 a formed in the passage 24, and the other end is connected to a rotary blade cover side opening 204 a formed in the rotary blade cover 4. The rear passage 224 functions as an example of the second passage. As shown in FIG. 12, the rotary blade cover side opening 204a formed in the rotary blade cover 4 is an upper part of the rotary blade cover side opening 4a and is formed on the rear side in the cutting direction. The rotary blade cover side opening 204 a is formed radially outward from the cutting edge of the rotary blade 3 when viewed from the axial direction of the rotary blade 3.

  As shown in FIG. 11, the first dust cover 51 is formed with a rear dust collection port 251 a at a position facing the rotary blade cover side opening 204 a when viewed from the axial direction of the rotary blade 3. The rear dust collection port 251a has a penetrating direction directed to the rear side in the cutting direction, and communicates the rotary blade accommodating space 40a and the chip dust collecting space 50a. The opening of the rear dust collection port 251a has a rectangular shape, and has a size such that the chips once entering the dust collection space 50a hardly come out to the rotary blade housing space 40a. It is smaller than the opening area of the dust mouth 51a.

  As shown in FIG. 13, the chip dust collection space 50a includes a first dust storage space 51d (a region surrounded by a dotted line in FIG. 13) on the front side in the cutting direction and a second dust storage space on the rear side in the cutting direction. 51e (region surrounded by a one-dot chain line in FIG. 13). The rear dust collection port 251a is formed in the region of the second dust storage space 51e on the rear side in the cutting direction with respect to the dust collection port 51a. As shown in FIG. 11, the rear dust collection port 251 a is formed in a radially outward portion of the rotary blade 3 with respect to the outer periphery of the rotary blade 3. More specifically, the rear dust collection port 251a is formed on the rear side in the cutting direction from the position above the engaging portion 52C when viewed from the axial direction of the rotary blade 3 when the second dust cover 52 is mounted (FIG. 13). . At this time, the dust collection port 51a is formed in the region of the first dust accommodating space 51d.

  Next, the operation of the portable circular saw 201 in the second embodiment will be described. When the switch 22 is pressed, a motor (not shown) and the centrifugal fan 71 are rotated. As shown in FIG. 14, the air taken into the motor accommodating portion 21 from the suction port 21a is carried into the passage 24 through the motor accommodating portion side opening 21b, and also to the rear passage 224 through the passage side opening 224a. Carried.

  The air flowing in each passage is jetted into the rotary blade accommodating space 40a through the rotary blade cover side openings 4a and 204a, respectively. And it flows in the chip dust collection space 50a of the dust box 5 through the dust collecting port 51a facing the rotating blade cover side opening 4a and the rear dust collecting port 251a facing the rotating blade cover side opening 204a (FIG. 10). .

  When the operator cuts the workpiece in this state, the relatively large mass of chips enters the chip dust collection space 50a through the dust collection port 51a as shown by an arrow A in FIG. It hits the part 52C and falls into the first dust storage space 51d ahead of the engaging part 52C and accumulates. As shown by an arrow B in FIG. 13, the relatively small mass of chips enters the chip dust collection space 50a through the rear dust collection port 251a without passing through the dust collection port 51a, and from the engaging portion 52C. Falls into the second dust storage space 51e behind and accumulates.

  A rear passage 224 for guiding the wind generated by the centrifugal fan 71 of the motor is further provided, and the rotary blade cover side opening 204a and the rear dust collection port 251a are formed at positions facing each other, whereby the dust collection port 51a. It is possible to collect the chips that could not be collected at one of the dust collection ports 251a and the rear dust collection port 251a at the other dust collection port. As a result, chips generated around the rotary blade 3 during cutting can be actively taken into the dust box 5 to improve dust collection efficiency.

  By forming the dust collection port 51a of the first dust cover 51 on the front side in the cutting direction and forming the rear dust collection port 251a on the rear side in the cutting direction, the engagement portion 52C located substantially in the center of the dust box 5 is hindered. The dust can be collected on the rear side in the cutting direction in the dust box 5 without any problems. Thereby, the space in the dust box 5 can be used effectively, and the dust collection rate can be improved.

  Even if the first dust storage space 51d is full, the dust collection port 51a is provided in the first dust storage space 51d and the rear dust collection port 251a is provided in the second dust storage space 51e. Chips can be collected in the dust accommodating space 51e. Thereby, the space in the dust box 5 can be used effectively, and the dust collection rate can be improved.

  Further, the rear dust collection port 251a is disposed in the second dust accommodating space region 51e and radially outward of the rotary blade 3 rather than the outer periphery of the rotary blade 3, so that the chips are passed through the rear dust collection port 251a. The chips collected in the dust collection space 50a can be sent to the rear side in the cutting direction (second dust storage space 51e) from the engaging portion 52C, and the chips are concentrated in the first dust storage space 51d. It can suppress that it accumulates.

  Next, a modification of the second embodiment will be described with reference to FIG. In addition, the same structure as 2nd Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  In the modification, one end of the rear passage 224 ′ is connected to the motor accommodating portion side opening 221 b formed in the motor accommodating portion 21, and the other end is connected to the rotating blade cover side opening 204 a formed in the rotating blade cover 4. ing. The rear passage 224 'functions as an example of the third passage. The motor housing portion side opening 221b formed in the motor housing portion 21 is formed radially outward of the centrifugal fan 71 in the same manner as the motor housing portion side opening 21b. That is, the motor accommodating portion side openings 21 b and 221 b are both formed on the inner surface of the motor accommodating portion 21 and on the circumference around the rotation axis of the centrifugal fan 71.

  With such a configuration, the same effect as in the second embodiment can be obtained.

  Next, a third embodiment of the present invention will be described with reference to FIG. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  In the housing 2, a passage 324 shown in FIG. 16 is formed instead of the passage 24 shown in the above-described embodiment. One end of the passage 324 is connected to a motor accommodating portion side opening 321 b formed in the motor accommodating portion 21, and the other end is connected to a rotating blade cover side opening 304 a formed in the rotating blade cover 4. An illumination device 326 is provided on the other end side of the passage 324, and the passage 324 passes through the illumination device 326 or is connected to the rotary blade cover side opening 304 a so as to cover the outer periphery of the illumination device 326. . The lighting device 326 is connected to a base (not shown) by a wiring 326 </ b> A, and the wiring 326 </ b> A is disposed in the passage 24. That is, the passage 324 serves as a wiring cover that covers the wiring 326 </ b> A of the lighting device 326.

  By disposing the lighting device 326 and the wiring 326A of the lighting device 326 in the passage 324 that guides the wind of the fan, heat generation of the lighting device 326 and the wiring 326A can be suppressed by the wind. Furthermore, since the passage 324 also serves to hold the lighting device 326 and the wiring 326A, it is not necessary to newly form a holding member for the lighting device 326, and the number of parts can be reduced. By providing the passage 24 and the lighting device 326, it is possible to improve the dust collection efficiency of the chips and improve the visibility of the cut portion.

  The cutting machine of the present invention is not limited to the embodiment described above, and various modifications and improvements can be made within the scope described in the claims. For example, at least one of the opening of the dust collection port 51a and the opening of the rear dust collection port 251a may be provided with a lid member that can open and close the opening.

  By adopting such a configuration, according to the difference in the mass of the chips due to the difference in the workpiece, the dust collection port 51a and the rear dust collection port 251a are appropriately closed or opened, It can be adjusted so that the maximum amount of chips can be collected into the chip dust collection space 50a.

  Further, although only one rear dust collection port 251a is formed, the number is not limited to one. Further, the size and shape of the dust collection port 51a and the rear dust collection port 251a are not limited to the size and shape of the present embodiment. In addition, the position where the dust collection port 51a and the rear dust collection port 251a are formed is not limited to the position of the present embodiment as long as the position is opposed to the rotary blade cover side openings 4a and 204a. It is only necessary that the other of the dust storage spaces 51d is formed in the region of the second dust storage space 51e.

  Further, the cylindrical mouth portion 55A of the connection portion 55 of the second dust cover 52 is closed by the cap 56, but instead of the cap 56, a filter that allows air to pass therethrough and prevents chips from passing through is provided. Also good. With such a configuration, the air flow can be made smoother and the dust collection efficiency can be further improved.

  Further, although the passage 24 and the rear passage 224 are provided along the outer surface of the housing 2, they may be formed by a member different from the housing 2. Specifically, a passage may be formed so as to pass through the inside of the housing 2.

  In the second embodiment, two passages (the passage 24 and the rear passage 224) that connect the motor housing portion 21 and the rotary blade cover 4 are formed. However, the present invention is not limited to this, and three or more passages are formed. May be.

  Although the rotary blade cover side opening 4a and the dust collecting port 51a are located on a straight line parallel to the rotational axis of the rotary blade 3, they may be located on a straight line even if they are not parallel to the rotational axis. . Specifically, the position in which the penetrating direction of the rotary blade cover side opening 4a and the penetrating direction of the dust collecting port 51a are oriented in the same direction, and the air that has exited from the rotating cover side opening 4a flows straight into the dust collecting port 51a. It is only necessary that both are formed.

  Further, although the centrifugal fan is used as the fan for cooling the motor 7, for example, an axial fan may be used. In this case, since the air flows in the axial direction of the motor without changing the direction from the suction port 21a, the passage 24 and the rear passage 224 are preferably formed to pass through the inside of the housing 2.

  In addition, a dust collector that actively sucks air in the dust box 5 can be connected to the connecting portion 55. When the workpiece is cut while the dust collector is in operation, the dust collection rate is 90% or more. Thereby, the dust generated more efficiently can be collected.

  The cutting machine of the present invention is particularly useful in the field of portable cutting machines and the like that are required to efficiently collect dust.

DESCRIPTION OF SYMBOLS 1 ... Portable circular saw, 2 ... Housing, 21b ... Motor accommodation part side opening, 24 ... Passage, 3 ... Rotary blade, 4 ... Rotary blade cover, 40a ... Rotating blade housing space, 4a ... opening on the rotating blade cover side, 5 ... dust box, 51 ... first dust cover, 51a ... dust collection port, 51d ... first dust housing space, 51e ... 2nd dust storage space, 50a ... Chip dust collection space, 51a ... Dust collection port, 251a ... Back dust collection port, 52C ... Engagement part, 6 ... Base part , 71 ... Centrifugal fan, 204a ... Rotary blade cover side opening, 221b ... Motor housing part side opening, 224 ... Rear passage, 251a ... Rear dust collection port, 326 ... Illumination device

Claims (11)

A housing having a motor housing portion and a rotary blade cover;
A motor housed in the motor housing section;
A fan housed in the motor housing portion for cooling the motor;
A rotary blade driven by the motor and partially covered by the rotary blade cover;
A dust box detachably provided in the housing and formed with a dust collection port communicating with the rotary blade cover;
A first passage having one end opened in the motor housing portion and the other end opened in the rotary blade cover and guiding wind generated by rotation of the fan to the rotary blade cover;
The portable cutting machine, wherein the other end is opened at a position facing the dust collecting port.   2. The portable cutting machine according to claim 1, wherein the other end is opened at a position overlapping with at least a part of a blade edge of the rotary blade as viewed in the axial direction of the rotary blade.   The portable cutting machine according to claim 2, wherein the fan is a centrifugal fan, and the one end is opened radially outward of the centrifugal fan.   The portable cutting machine according to claim 1, wherein at least two dust collecting ports are formed, and the other end is opened at a position facing any one of the dust collecting ports.   The dust collecting port further comprises a second passage having one end opened in the first passage and the other end opened in the rotary blade cover and guiding wind generated by the rotation of the fan to the rotary blade cover. The other end of the first passage opens at a position facing the other, and the other end of the second passage opens at a position facing the other one of the dust collection ports. The portable cutting machine according to claim 4.   A third passage that has one end opened in the motor housing and the other end opened in the rotary blade cover and guides the wind generated by the rotation of the fan to the rotary blade cover; The other end of the first passage is opened at an opposing position, and the other end of the third passage is opened at a position facing any one of the other dust collection ports. Item 5. A portable cutting machine according to Item 4.   An engagement portion for mounting the dust box to the housing is provided at a substantially central portion of the dust box, and the dust collection port facing the position where the other end of the first passage opens and the first Either one of the dust collection ports facing the position where the other end of the two passages opens is formed on the front side in the cutting direction, and faces the position where the other end of the first passage opens. The other dust collection port of the dust collection port facing the position where the other end of the second passage opens and the dust collection port that is in the rear side in the cutting direction from the position above the engagement portion The portable cutting machine according to claim 5, wherein the portable cutting machine is formed.   An engagement portion for mounting the dust box to the housing is provided at a substantially central portion of the dust box, and a space in the dust box is divided into a first dust storage space and a second dust storage space by the engagement portion. The dust collection port facing the position where the other end of the first passage opens and the dust collection port facing the position where the other end of the second passage opens. The dust collection port is formed in the first dust accommodating space, and is opposed to the position where the other end of the first passage opens and the position where the other end of the second passage opens. 8. The portable cutting machine according to claim 7, wherein the other dust collection port of the dust collection ports facing each other is formed in the second dust storage space.   2. A light source that illuminates the periphery of a cutting portion of a material to be cut that is cut by the rotary blade, and the light source is held on the other end side of the first passage. Item 9. The portable cutting machine according to any one of items 8. The portable cutting machine according to claim 9, wherein the wiring of the light source is disposed in the first passage.   The portable cutting machine according to claim 1, wherein the first passage is provided in the housing.

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