JP4120551B2 - Portable electric cutting machine - Google Patents

Description

  The present invention relates to a portable electric cutting machine, and in particular, a portable electric cutting machine (hereinafter referred to as a portable electric circular saw) having a structure for discharging a fan wind of a fan that cools a motor from a housing into a saw blade storage portion of a saw cover. )

  When cutting a material to be cut such as wood using a portable electric circular saw, in order to improve cutting accuracy, a marking line is drawn on the cutting material in advance, and the cutting is performed along the marking line. . Specifically, a guide piece indicating the position of the saw blade is provided on the extension line in the cutting direction of the saw blade edge and at the front portion in the cutting direction of the base. For example, a guide piece is provided at the front end portion of the base, and cutting is performed while indirectly confirming the positional relationship between the saw blade edge and the marking line by aligning the guide piece with the marking line. Alternatively, the cutting operation is performed while directly confirming the positional relationship between the marking line on the material to be cut and the saw blade edge immediately before cutting.

  However, if a large amount of chips generated during the cutting of the material to be cut accumulates on the material to be cut, the marking line may become difficult to see, and the positional relationship between the marking line and the saw blade edge is confirmed. It is difficult to cause a reduction in cutting accuracy and workability may be reduced.

  The reason why the chips accumulate on the material to be cut is that the chips generated during the cutting work soar and accumulate on the material to be cut. Even when cutting using a dust collector or the like to prevent chips from flying up during cutting operations, chips or other materials on the material to be cut during other cutting operations or various operations with other tools Dust or the like may accumulate, making it difficult to see the marking lines.

  In such a case, in order to confirm the marking line on the material to be cut, it is necessary to wipe off or blow off the chips on the material to be cut before the cutting operation, and workability is deteriorated. Further, during the work, it is necessary to temporarily suspend the work, and there is a possibility that the cutting accuracy and workability are lowered.

  An example of a conventional portable electric circular saw is described in Patent Document 1. The electric circular saw described in the document has a housing that houses a motor, a saw blade that is driven to rotate by the motor, and a shape that is attached to the housing and can cover almost the upper half of the outer periphery of the saw blade. A saw cover having a saw blade storage portion for storing a part of the motor, a base connected to the housing and having a bottom surface that can slide on the material to be cut, and a motor driven by a fan wind that is driven and rotated by the motor And a fan for cooling. On the wall surface of the saw cover between the fan and the saw blade storage portion, a fan air discharge port for discharging fan air to the saw blade storage portion side is formed, and a plurality of partition walls defining a fan air discharge passage are provided. ing.

In Patent Document 2, a cylindrical guide pipe is provided outside the saw cover and along the housing side so as to communicate with the fan discharge port. The fan wind from the fan discharge port is guided to the vicinity of the material to be cut through the guide pipe, and chips are prevented from accumulating on the material to be cut.
Registered Utility Model No. 2607480 Japanese Utility Model Publication No. 55-154101

  The portable electric circular saw described in Patent Document 1 has a configuration in which a plurality of partition walls defining a fan air discharge port extend radially around the rotation axis of the fan and have a surface extending in parallel with the rotation axis of the fan. . The fan wind discharged into the saw blade housing through the fan wind discharge port is given a directivity so as to be discharged along the rotation axis direction of the fan when passing through the fan wind discharge port. Therefore, the fan wind collides with the side surface of the saw blade in the saw blade storage unit and the side surface of the safety cover that is rotatably provided so as to be stored in the saw blade storage unit during cutting work. Diffuses along the side. The diffused fan wind is discharged to the outside of the saw cover through the space between the inner wall of the saw cover and the saw blade or between the inner wall of the saw cover and the safety cover. Since the fan wind collides with the side of the saw blade or the safety cover at a substantially right angle, the fan wind spreads almost uniformly over a wide range after the collision, and the air in the saw blade housing generated by the rotation of the saw blade Depending on the flow, the fan wind may be discharged from the rear in the cutting direction.

  In addition, a centrifugal fan is used as the fan, and the fan wind discharged toward the outside in the radial direction of the centrifugal fan by the rotation of the centrifugal fan is sawn through the fan wind discharge port while turning almost along the inner wall of the housing. It is discharged into the blade storage part. At this time, the fan air volume in the fan air outlet and the air volume and speed of the fan exhaust air exhausted from the fan air outlet are large outward in the radial direction around the rotation axis of the fan, and small in the radially inward direction. It was something that would end up. For this reason, generation of noise in the radially outward direction becomes a problem. In order to solve this problem, if the fan is downsized or the number of rotations of the motor is reduced, the air flow becomes insufficient and the cooling performance of the motor is lowered.

  According to the portable electric circular saw described in Patent Document 2, chips accumulated on the upper surface of the workpiece near the base opening can be blown away, but the guide pipe has a positional relationship between the marking line and the blade edge of the saw blade. When confirming, the visibility of the marking line decreases, and the number of parts increases, resulting in a decrease in assemblability and an increase in cost. In addition, there are work sites that do not want to use a fan flow to disperse chips, such as cutting operations in narrow closed rooms or cutting operations on wall surface coating when the paint is in an undried state.

  Therefore, the present invention can effectively suppress the accumulation of chips on the marking line on the material to be cut by using the fan wind generated by the rotation of the fan provided to cool the motor, and can improve the cutting accuracy. An object of the present invention is to provide a portable electric circular saw that can improve the workability and workability, and can selectively prevent chips from being scattered during the cutting work according to the necessity of the work site.

  In order to achieve the above object, an invention according to claim 1 is characterized in that a housing for housing a motor for rotating a saw blade, a housing attached to the housing and covering a substantially upper half of the outer periphery of the saw blade, A saw cover having a saw blade receiving portion for storing a part of the saw blade, and a bottom surface that is connected to at least one of the housing or the saw cover and is slidable on the material to be cut, and the saw blade is below the bottom surface A portable electric cutting machine comprising: a base having a projectable opening formed therein; and a fan provided in a housing for cooling the motor and driven to rotate by the motor. A fan wind passage groove connected to the opening in the cutting direction of the opening and connected to the opening and extending to the front end in the cutting direction of the base and opening at the front end is formed on the bottom surface. Between the A plurality of partition walls are provided on the wall surface of the cover, and a fan wind discharge port is formed between adjacent partition walls to direct the fan air in the opening direction of the base and forward in the cutting direction. It is possible to flow into the fan wind passage groove, and the base is provided with a fan wind blowing adjustment mechanism for adjusting blowout of the fan wind from the opening at the front end of the base.

  According to such a configuration, the fan wind generated by the rotation of the fan cools the motor, and is then discharged from the opening at the front end of the base via the fan wind passage groove. The fan air discharged from the opening blows away the chips on the member to be cut, and prevents the chips from accumulating on the marking lines on the material to be cut. The fan wind blowing adjustment mechanism adjusts the blowing of fan wind from the opening at the front end of the base.

  The invention according to claim 2 is the portable electric cutting machine according to claim 1, wherein the bottom surface of the base merges with the fan air passage groove and has a depth substantially equal to the depth of the fan air passage groove. The fan air blowing adjustment mechanism is slidable along the guide groove between a shielding position that blocks the fan air passage groove and a non-shielding position that opens the fan air passage groove. A shielding member is provided.

  According to such a configuration, in a state where the shielding member is located at the non-shielding position and the fan air passage groove is opened, the fan air that has flowed into the fan air passage groove is discharged from the opening at the front end of the base and on the material to be cut. Prevents chips from accumulating on the marking lines. On the other hand, when the shielding member is slid along the guide groove to the shielding position, the shielding member blocks the fan air passage groove, and the fan air is discharged from the opening at the front end of the base through the fan air passage groove. To prevent. Further, when the shielding member is slid between the non-shielding position and the shielding position, the air volume of the fan air discharged from the opening at the front end of the base via the fan air passage groove is adjusted.

  Invention of Claim 2 is portable electric cutting machine of Claim 2, Comprising: This fan wind blowing adjustment mechanism is the fastening which fixes / releases the sliding position of this shielding member with respect to this base A member is further provided. According to this configuration, the sliding position of the shielding member is fixed / released with respect to the base by the fastening member.

  A fourth aspect of the present invention is the portable electric cutting machine according to the first aspect, wherein the base is formed with a guide hole that joins the fan air passage groove, and the fan air blowing adjustment mechanism is a fan A shielding member slidable along the guide hole between a shielding position for blocking the air passage groove and a non-shielding position for opening the fan air passage groove; and sliding of the shielding member while supporting the shielding member It is characterized by being comprised by the adjustment member which adjusts a position.

  According to this configuration, the sliding position of the shielding member is adjusted by operating the adjustment member. When the sliding position of the shielding member is adjusted to the non-shielding position, the fan air passage groove is opened, and the fan air that has flowed into the fan air passage groove is discharged from the opening at the front end of the base and cut on the marking line on the workpiece. Prevent powder accumulation. When the sliding position of the shielding member is adjusted to the shielding position, the shielding member blocks the fan air passage groove and prevents the fan air from being discharged from the opening at the front end of the base through the fan air passage groove. Further, when the sliding position of the shielding member is adjusted between the non-shielding position and the shielding position, the amount of fan wind discharged from the opening at the front end of the base via the fan wind passage groove is adjusted.

  Invention of Claim 5 is a portable electric cutting machine of Claim 1, Comprising: This fan wind blowing adjustment mechanism is a shielding member which has a shielding surface and an open surface, and this shielding member is this shielding surface. And a fixing member that is detachably fixed to the base in a first state in which the base is directed toward the bottom surface of the base and in a second state in which the open surface is directed toward the bottom surface of the base, The shielding surface has substantially the same width as the fan wind passage groove, and a shielding portion is provided to block the fan wind passage groove while the shielding member is fixed to the base in the first state. The open surface is formed with a groove that communicates with the fan air passage groove and opens the fan air passage groove when the shielding member is fixed to the base in the second state. It is characterized by having.

  According to this configuration, when the shielding member is fixed to the base in the first state, the shielding member blocks the fan air passage groove, and the fan air is discharged from the opening at the front end of the base through the fan air passage groove. To be prevented. On the other hand, in a state where the shielding member is fixed to the base in the second state, the fan wind that has flowed into the fan wind passage groove passes through the groove formed on the open surface of the shielding member and is discharged from the opening at the front end of the base. This prevents the chips from accumulating on the marking lines on the material to be cut.

  According to the portable electric cutting machine of the first aspect, the fan wind generated by the rotation of the fan cools the motor, and is then discharged from the opening at the front end of the base via the fan wind passage groove. The fan air discharged from the opening blows away the chips on the member to be cut, and prevents the chips from accumulating on the marking lines on the material to be cut. Therefore, it is possible to improve the cutting accuracy by preventing the marking lines from becoming difficult to see due to the chips and dust accumulated on the material to be cut. Further, since chips and dust can be blown off during the cutting operation, it is not necessary to interrupt the operation in order to remove the chips accumulated on the material to be cut, and the workability can be improved. In addition, since the fan air is discharged from the opening at the front end of the base through the fan air passage groove formed on the bottom surface of the base, there is no need to separately provide a guide pipe for guiding the fan air, and the number of parts is reduced. As a result, the guide pipe does not obstruct the positional relationship between the marking line and the blade edge of the saw blade.

  Since the fan wind blowing adjustment mechanism adjusts the amount of fan wind blown from the opening at the front end of the base, the fan wind blowing amount can be arbitrarily set. Therefore, at work sites that do not like the use of fan air to disperse chips, the fan air blown out from the opening at the front end of the base can be eliminated to prevent chips from being scattered. In addition, while preventing chip accumulation on the marking line, it is possible to minimize the scattering of chips by controlling the air volume, and selectively disperse chips during cutting work according to the necessity at the work site. Can be prevented.

  According to the portable electric cutting machine according to claim 2, when the shielding member is located at the non-shielding position and the fan air passage groove is opened, the fan air flows into the fan air passage groove and opens at the front end of the base. Prevents the chips from being deposited on the marking lines on the material to be cut. On the other hand, when the shielding member is slid along the guide groove to the shielding position, the shielding member blocks the fan air passage groove, and the fan air is discharged from the opening at the front end of the base through the fan air passage groove. To prevent. Therefore, it is possible to selectively prevent the chips from being scattered using the fan wind simply by sliding the shielding member along the guide groove. According to the portable electric cutting machine of the third aspect, since the sliding position of the shielding member is fixed, the fan wind discharge amount can be stabilized.

  According to the portable electric cutting machine of the fourth aspect, when the shielding member is in the non-shielding position, the fan wind flowing into the fan wind passage groove is discharged from the opening at the front end of the base, and is on the material to be cut. Prevents chips from accumulating on the marking line, and adjusting the shielding member to the shielding position blocks the fan air passage groove and prevents the fan air from being discharged from the opening at the front end of the base through the fan air passage groove. To do. Further, when the sliding position of the shielding member is adjusted between the non-shielding position and the shielding position, the amount of fan wind discharged from the opening at the front end of the base via the fan wind passage groove is adjusted. Accordingly, it is possible to adjust the air volume of the fan air discharged from the opening at the front end of the base simply by adjusting the sliding position of the shielding member, and it is possible to selectively prevent the scattering of chips using the fan air.

  According to the portable electric cutting machine of claim 5, when the shielding member is fixed to the base in the first state, the shielding member blocks the fan wind passage groove and the shielding member is in the second state. In the fixed state, the fan air that has flowed into the fan air passage groove passes through the groove formed on the open surface of the shielding member, is discharged from the opening at the front end of the base, and chips on the marking line on the material to be cut To prevent deposition. Therefore, it is possible to selectively prevent the chips from being scattered using the fan wind simply by changing the state of attachment of the shielding member to the base.

  A portable electric cutting machine according to a first embodiment of the present invention will be described with reference to FIGS.

(1) Basic Configuration As shown in FIGS. 1 to 3, a portable electric circular saw includes a housing 2 that supports and accommodates a motor 1 therein, a handle 3, and a saw blade 4 that is rotationally driven by the motor 1. The saw cover 5, the base 6 and the fan 7 are mainly provided. The handle 3 is provided integrally with the housing 2 or connected as a separate member, and includes a switch 3 a that controls driving of the motor 1. The saw cover 5 is attached to the housing 2 so as to cover the upper half of the outer periphery of the saw blade 4, and has a saw blade storage portion 5 a for storing a part of the outer periphery of the saw blade 4 and a side surface on the motor 1 side. The base 6 is connected to the housing 2 via the saw cover 5, has a bottom surface 6a that can slide on the material to be cut, and an opening 6b that protrudes the saw blade 5 downward from the bottom surface 6a. The fan 7 is fixed to the output shaft 1 a of the motor 1, rotates with the output shaft 1 a by driving the motor 1, and generates a fan wind when rotating to cool the motor 1. As shown in FIG. 15, a fan air discharge port 5c for discharging fan air to the saw blade housing portion 5a is formed in the portion of the saw cover 5 between the fan 7 and the saw blade housing portion 5a. A plurality of partition walls 5d are provided to partition the discharge port 5c.

  As shown in FIG. 3, an air suction port 2 a is formed on one end surface of the housing 2 so that the inside of the housing 2 communicates with the outside. When the fan 7 rotates, air (fan wind) flows into the housing 2 from the air suction port 2a, and the air passes through the outer periphery of the motor 1, thereby cooling the motor 1. Thus, the fan 7 is provided for the purpose of cooling the motor 1 by the fan air. The rotation direction of the fan 1 is a direction indicated by an arrow D in FIG. 2 (hereinafter referred to as “fan rotation direction D”).

  A pinion gear 8 is integrally or separately provided at one end of the output shaft 1 a of the motor 1, and the pinion gear 8 meshes with a gear 9 that is rotatably held by the saw cover 5. The gear 9 is fixed to a coaxial drive shaft 10, and this drive shaft 10 is rotatably held on the saw cover 5 by coaxial bearings 11 and 12 arranged so as to sandwich the gear 9. A pair of saw blade fixing members 13 that are not rotatable with respect to the drive shaft 10 are mounted on the drive shaft 10, and the motor 1 is driven by holding the saw blade 4 between the saw blade fixing members 13. Sometimes, the rotational force of the output shaft 1a is transmitted through the pinion gear 8, the gear 9, the drive shaft 10, and the saw blade fixing member 13, and the cutting operation by the saw blade 4 becomes possible. The rotational force of the output shaft 1 a is decelerated by one stage by the above-described pinion gear 8 and gear 9 and transmitted to the saw blade 4. The rotation direction of the saw blade 4 is opposite to the fan rotation direction D.

  The portable electric circular saw has a shape that is rotatably held coaxially with the drive shaft 10 in the saw blade storage portion 5a, can be stored in the saw blade storage portion 5a, and covers almost half of the outer periphery of the saw blade 4. A safety cover 17 is provided. A lever 17a for manual rotation operation is attached to the safety cover 17. The safety cover 17 is biased by a biasing means such as a spring (not shown). As shown in FIG. 1, the safety cover 17 protrudes below the bottom surface 6a of the base 6 and prevents the outer periphery of the saw blade 4 from being exposed. The moving position is in the initial state. At the time of cutting, the front end of the safety cover 17 in the cutting direction (the right side in FIG. 2) abuts the end of the material to be cut, and in this state, the portable electric circular saw slides in the cutting direction to form a spring. On the contrary, the safety cover 17 rotates so as to be housed in the saw blade housing portion 5 a, and the saw blade 4 is exposed on the bottom surface 6 a of the base 6. In the case of a window extraction operation or the like in which cutting is performed on the upper surface of the material to be cut that is not continuous with the end surface, the operator operates the lever 17 a to rotate the safety cover 17, and the saw blade 4 is moved on the bottom surface 6 a of the base 6. Can be exposed. The saw cover 5 has a pinion gear storage portion 5 e for storing the pinion gear 8. The pinion gear storage portion 5e has a substantially circular shape, and a bearing 14 that rotatably supports the pinion gear 8 is attached to the saw cover 5 by press-fitting or the like in order to position the pinion gear 8 at a substantially central position of the pinion gear storage portion 5e. .

  The end surface of the saw cover 5 is attached to the end surface of the housing 2 with screws 15. The pinion gear storage 5e is provided between the saw blade storage 5a and the end face on the housing 2 side, and has a shape for storing the gear 9. A portion between the saw blade storage portion 5a and the end surface on the housing 2 side functions as a gear casing. As shown in FIG. 2, the saw cover 5 is connected to the base 6 so that the saw blade 4 is sandwiched between the vicinity of the front end side and the rear end side of the base 6. The connecting portion is provided with a saw blade tilt adjusting mechanism and a saw blade cutting depth adjusting mechanism.

(2) Saw blade tilt adjustment mechanism
The saw blade tilt adjustment mechanism includes a front end side tilt adjustment mechanism located near the front end side (front side in the cutting direction) of the base 6 and a rear end side tilt adjustment mechanism located near the rear end side of the base 6. As shown in FIG. 1, the tip side tilt adjustment mechanism includes a rotation shaft member 20, a hinge holding portion 21, a bevel plate 23, and a bolt 24, and as shown in FIGS. 2 and 8, The end side tilt adjustment mechanism includes a pin 25, a link 26, a bolt 27, a bevel plate 28, and a bolt 29.

  The tip side tilt adjustment mechanism will be described with reference to FIGS. 1 and 4 to 6. The pin 22 extends in a direction perpendicular to the rotation axis of the saw blade 4 and is fixed to the base 6 in the vicinity of the end on the front side in the cutting direction of the base 6. The pin 22 functions as a first tilt fulcrum. The bevel plate 23 extends substantially parallel to the front end surface of the base 6 and is erected from the base 6, and is formed with an arc-shaped long hole 23 a centering on the pin 22. The hinge holding portion 21 is provided so as to be rotatable in the left-right direction with respect to the base 6 around the axis of the pin 22. A bolt 24 that penetrates the long hole 23 a is screwed into the hinge holding part 21, and the rotation position of the hinge holding part 21 is fixed by tightening the bolt 24 with respect to the long hole 23 a of the bevel plate 23. . Accordingly, when the bolt 24 is loosened with respect to the long hole 23a and the housing 2 is lifted upward from the state of FIG. 5, the hinge holding portion 21 rotates around the pin 22 and tilts as shown in FIG. This tilting position is maintained by tightening the bolt 24. The hinge holding part 21 is substantially U-shaped so as to sandwich the tip end side of the saw cover 5 from the left and right sides (FIG. 4), and the rotating shaft member 20 is rotatably held by the hinge holding part 21. A hole 5 f (FIG. 15) extending substantially parallel to the rotational axis direction of the saw blade 4 is formed in the vicinity of the distal end side end of the saw cover 5, and the rotating shaft member 20 can rotate to the hinge holding portion 21. And inserted into the hole 5f. Accordingly, the saw cover 5 can be pivoted in the vertical direction with respect to the hinge holding portion 21 via the pivot shaft member 20.

  4, 5, and 6, 6 c is a groove portion of the base 6 to be described later, 16 is a guide piece to be described later, 16 a and 16 b are guide portions to be described later, 18 is a screw to be described later, and 5ia is a plane of a saw cover to be described later. , 34a and 34b are irradiation devices to be described later, and 34aa is an LED to be described later.

  The rear end side tilt adjustment mechanism will be described with reference to FIGS. The pin 25 extends in a direction perpendicular to the rotation axis direction of the saw blade 4 in a direction along the upper surface of the base 6 and constitutes a second inclined fulcrum. The pin 25 and the pin 22 are arranged so that a virtual line connecting them is substantially parallel to the surface direction of the saw blade 4. A link 26 is connected to the pin 25, and the link 26 can rotate in the left-right direction of the base 6 around the pin 25. The bevel plate 28 extends substantially parallel to the rear end surface of the base 6 and is erected from the base 26, and is formed with an arc-shaped elongated hole 28 a centering on the pin 25. A bolt 29 that passes through the long hole 28 a of the bevel plate 28 is screwed into the link 26, and the rotation position of the link 26 relative to the base 6 can be fixed by tightening the bolt 29.

  As described above, the saw cover 5 and the base 6 are connected via the pin 22 constituting the first tilt fulcrum and the pin 25 constituting the second tilt fulcrum, and the first and second tilt fulcrums are used as fulcrums. As a result, the saw cover 5 and the base 6 can be rotated relative to each other, and the angle of the saw blade 4 with respect to the bottom surface 6a of the base 6 can be inclined by this rotation. 6 and 8 show a state in which the saw cover 5 is inclined with respect to the base 6 so that the side surface of the saw blade 4 forms an angle of 45 degrees with respect to the bottom surface 6a of the base 6 with the pins 22 and 25 as fulcrums. It shows, and it inclines to 45 degree | times of the maximum inclination angle set by this embodiment.

  The hinge holding portion 21 and the link 26 can be tilted and rotated within the range of the long holes 23a and 28a of the bevel plates 23 and 28, and the wall surface of the bevel plates 23 and 28 on the saw blade 4 side (that is, the bevel plate 23). And the rear side surface and the front side surface of the bevel plate 28). The wall surface on the saw blade 4 side of the bevel plates 23 and 28 is machined to obtain surface accuracy (particularly the bevel plate 23), and is configured to substantially abut against a part of the hinge holding portion 21 and the link 26, respectively. Thus, the positional accuracy at the time of relative rotation with the pins 22 and 25 of the saw cover 5 and the base 6 as fulcrums is ensured.

  In the present embodiment, the bevel plate 23 and the bevel plate 28 are provided in both the vicinity of the front end and the rear end in the cutting direction of the base 6, but this is caused by the load applied to the main body when inclined. This is to prevent the tilt angle from shifting. The tilt fulcrums 22 and 25 that are fulcrums at the time of normal tilt cutting are located at positions close to the longitudinal extension line of the saw blade 4. This is so that the position at which the saw blade 4 protrudes from the lower surface of the base 6 at the time of inclined cutting is not significantly different from the position at which the saw blade 4 protrudes at the right-angle cutting, and to obtain a greater depth of cutting at the time of inclined cutting. It is. On the other hand, since the handle 3 is located at a position away from the saw blade 4, the load applied to the handle 3 works in a direction in which the saw cover 5 and the housing 2 are inclined and rotated with respect to the base 6. In view of the above, it is preferable to provide bevel plates 23 and 28 at both the front and rear connecting portions of the saw cover 5 and the base 6 in the cutting direction. This is because the depth of cut can be prevented from changing unexpectedly, and the accuracy of the inclined position can be improved. However, a configuration in which the bevel plate 23 is provided only in the vicinity of either one, particularly in the vicinity of the front end side in the cutting direction may be employed.

(3) Saw blade depth adjustment mechanism
As described above, the saw cover 5 can be pivoted in the vertical direction with respect to the hinge holding portion 21 via the pivot shaft member 20. The lower portion of the link 26 is associated with the pin 25. As shown in FIG. 10, the upper portion of the link 26 can be inserted into the saw blade storage portion 5a of the saw cover 5, and has a link guide 26A having a shape substantially along the upper inner wall of the saw blade storage portion 5a of the saw cover 5. Yes. The link guide 26A is formed with an elongated hole 26a extending in the longitudinal direction of the upper portion, and a cutting depth adjusting bolt 27 attached to the saw cover 5 is disposed in the elongated hole 26a, and the bolt 27 is tightened. As a result, the relative position between the link guide 26A and the saw cover 5 is fixed.

  Therefore, on the front side of the saw cover 5, the saw cover 5 and the base 6 can be rotated relative to each other with the rotation shaft member 20 as a fulcrum, and the protrusion amount of the saw blade 4 from the bottom surface of the base 6 by this rotation. That is, the depth of cut is changed. The cutting depth can be fixed by operating the bolt 27. 9 and 10 show a state in which the saw cover 5 is rotated clockwise around the rotation support member 20, and the link guide 26A is exposed from the rear end portion of the saw cover 5 by this rotation. .

(4) Laser unit
As shown in FIGS. 4 to 6, a laser unit 34 including irradiation devices 34 a and 34 b is provided on the housing 2 (motor 1) side outer wall of the saw blade storage portion 5 a of the saw cover 5. As shown in FIG. 18, a concave portion 5i having a flat portion 5ia extending substantially parallel to the side surface of the saw blade 4 is formed on the outer wall of the saw blade storage portion 5a of the saw cover 5 on the housing 2 side. As shown in FIG. 16, two screw holes 5ib are formed. The laser unit 34 is attached to the flat surface portion 5ia with a screw 35 (FIG. 28) in a state where the irradiation device 34a is substantially in surface contact with the flat surface portion 5ia. The irradiation device 34a has two LEDs 34aa (FIG. 5), and irradiates a laser beam to indicate the cutting edge front end portion of the base 6 and the cutting edge front position of the saw blade 4 in front of the end portion in the cutting direction. . The irradiation device 34b has a shape protruding in the direction of the base 6 from the lower end on the top side of the saw cover 5 (FIGS. 25 and 28), and an LED (not shown) whose laser light irradiation direction is inclined with respect to the side surface of the saw blade 4 is provided. Have. The irradiation device 34b irradiates a laser beam in order to indicate the position of the blade edge of the saw blade 4 near the front of the opening 6b in the cutting direction (particularly near the blade edge of the saw blade 4). The activation of the laser unit 34 is controlled by an irradiation device switch 3b (FIG. 1) provided on the handle 3, and can be activated using a power source of a portable electric circular saw.

  Positioning accuracy is required for the arrangement of the laser unit 34, particularly the irradiation device 34a. However, the irradiation device 34a can be easily positioned by the above-described flat portion 5ia of the saw cover 5 and the outer shape of the laser unit 34. Assembling property can be improved. As shown in FIGS. 5 and 6, a recess 21 a is formed in a part of the hinge holding portion 21 located in the irradiation direction of the LED 34 aa of the irradiation device 34 a so as not to interfere with the laser light emitted from the LED 34 aa. Is formed.

(5) Base 6
Next, the base 6 will be described with reference to FIGS. The bevel plates 23 and 28 described above are provided near both ends of the base 6. The bevel plates 23 and 28 extend along the side surfaces of both ends of the base 6 and project from the upper surface of the base 6 so as to be orthogonal to the bottom surface 6 a of the base 6. The pins 22 and 25 constituting the connecting portion between the base 6 and the saw cover 5 described above are respectively held by the protrusions 30 and 32 protruding from the base 6. The protrusions 30 and 32 are provided integrally with the bevel plates 23 and 28, respectively. Specifically, the pin 22 on the front side in the cutting direction is held in a holding hole 31 formed in the protruding portion 30 shown in FIG. 12, and the pin 25 on the rear side in the cutting direction is formed on the protruding portion 32 shown in FIG. The holding hole 33 is held. The holding holes 31 and 33 are formed so that the central axes are located on the same line. This is substantially parallel to the longitudinal direction of the saw blade 4.

  As a modification, two protrusions 30 in which the holding holes 31 are formed are juxtaposed in the axial direction of the pins 22, and the pins 22 are held between the holding holes 31, 31 facing each other, and the protruding parts 30 facing each other. By adopting a configuration in which the hinge holding portion 21 is positioned between the end surfaces of the pins 22, deformation of the pin 22 connected to the hinge holding portion 21 can be suppressed. Therefore, even when a pressing force from the operator is excessively applied to the saw cover 5 through the handle 3 at the time of cutting work or the like, it is possible to suppress the occurrence of a deviation in inclination angle and a deviation in cutting depth.

  As particularly shown in FIG. 14, a groove 6 c that communicates with the opening 6 b and extends to the front end in the cutting direction of the base 6 is formed on the front side in the cutting direction of the bottom surface 6 a of the base 6. In the state shown in FIG. 9, the groove 6 c is located on the cutting direction extension line of the saw blade 4 and has a width dimension larger than the width dimension of the cutting edge of the saw blade 4. Further, the width dimension of the groove portion 6c has a sufficient width so that the extended line of the line where the side surface of the saw blade 4 intersects the bottom surface 6a of the base 6 is located within the range of the groove portion 6c even at the time of inclined cutting ( (See FIG. 6). As shown in FIG. 12, the height of the groove 6c is about half or less than the thickness of the base 6 around the groove 6c.

  As shown in FIGS. 1, 4, 5, and the like, a guide piece 16 indicating the position of the cutting edge of the saw blade 4 is detachably attached to the upper surface of the base 6 with a screw 18 at the front portion in the cutting direction of the groove 6 c. The guide piece 16 has a guide portion 16a indicating the cutting edge of the saw blade 4 when the angle of the side surface of the saw blade 4 with respect to the bottom surface 6a of the base 6 is a right angle, and an angle of the side surface of the saw blade 4 with respect to the bottom surface 6a of the base 6 is 45. And a guide portion 16b pointing to the cutting edge of the saw blade 4 at the time.

  The bottom surface of the guide piece 16 is formed so as to be substantially flush with the top surface of the groove portion 6c of the base 6 except for the guide portions 16a and 16b. The bottom surfaces of the guide portions 16a and 16b are the bottom surface 6a of the base 6. Protrudes downward until it matches. Thereby, the position of the guide part 16a or 16b with respect to the marking line drawn on the material to be cut can be easily adjusted.

  As described above, the groove 6 c is formed on the longitudinal extension line of the saw blade 4, and the pin 22 is also provided at a position close to the longitudinal extension line of the saw blade 4. Above, it will be located above the groove 6c (FIG. 12). The projecting portion 30 forming the holding hole 31 for holding the pin 22 has a shape extending over the portion directly above and the non-upper portion of the groove 6c (the vicinity where the left side portion of the bevel plate 23 stands). ing. Thereby, even when a pressing force from an operator is excessively applied to the saw cover 5 via the handle 3 during a cutting operation or the like, the protrusion 6 may deform the vicinity of the groove 6c particularly in the base 6. Can be suppressed. Further, a reinforcing rib 6e extending over the portion directly above the groove 6c and the non-upper portion and continuing to the protruding portion 30 is provided protruding above the base 6. The strength of the base 6 around the groove, which is reduced by forming the groove 6c, can be supplemented by the reinforcing rib 6e. The reinforcing rib 6e may be provided independently of the protruding portion 30.

  As shown in FIG. 14, a hole 6 d communicates with the groove 6 c and is formed through the base 6. This hole 6d is formed by machining for improving the surface accuracy of the surface of the protruding portion 30 on the saw blade 4 side. Since the pin 22 is held in the vicinity of the upper surface of the base 6, the lower portion of the hinge holding portion 21 protrudes downward from the upper surface of the base 6. The hole 6d also has a function of accommodating the lower part of the hinge holding part 21.

(6) Blower configuration
A blower configuration using the fan air generated by the fan 1 for cooling the motor 1 will be described with reference to FIGS. 3 and 15 to 28. The gear casing portion of the saw cover 5 has a width at least greater than the width of the gear 9 (FIG. 3) (the dimension in the axial direction of the output shaft 1a). As shown in FIG. 15, a fan wind discharge port 5 c is formed in the gear casing portion of the saw cover 5 and is located radially outward of the pinion gear 8. The fan air discharge port 5c is provided to guide the fan air that has flowed through the housing 2 and has cooled the motor 1 from the housing 2 into the saw blade storage portion 5a.

  The fan wind outlet 5c is defined by a plurality of partition walls 5d provided integrally or separately with the saw cover 5. As shown in FIG. 3, the partition wall 5d has a width dimension L1 (dimension in the axial direction of the output shaft 1a) that is about 1/3 of the width dimension L of the gear casing portion of the saw cover 5. The radial dimension of the fan wind outlet 5c around the output shaft 1a is such that the outer periphery of the blade portion of the fan 7 is located within the range of the fan wind outlet 5c.

  In the present embodiment, seven partition walls 5d are provided, and the fan wind outlets 5c are arranged radially about the rotation axis C1 of the fan 7, as shown in FIGS. The partition wall 5d has partition walls 5da1, 5da2, 5da3, 5db, 5dc1, 5dc2, and 5dc3 arranged in order from the upstream side in the fan rotation direction D, and a fan wind outlet 5c is defined between the adjacent partition walls 5d. Since the partition walls 5da1 and 5da2 extend parallel to the rotational axis direction of the fan 7, only the end surfaces of the partition walls 5da1 and 5da2 are shown in FIGS. 15 and 19, and the gap between the partition walls 5da1 and 5da2 is a fan wind. It becomes the discharge port 5c. On the other hand, since the partition walls 5db and 5dc1 have portions (cooling air guide portions described later) that are not parallel to the rotation axis direction of the fan 7, in FIGS. 15 and 19, not only the end surfaces of these partition walls 5db and 5dc1, but also the partition walls. The cooling air guide part of 5db and 5dc1 is also visible. Accordingly, the cooling air guide portion is also shown as the fan air outlet 5c in the drawing.

  The partition wall 5d of the present embodiment is divided into three types. The first partition wall group is partition walls 5da1 to 5da3 that are located upstream of the rotation axis C1 of the fan 7 and the rotation axis C2 of the saw blade 4 in the cutting direction on the upstream side in the fan rotation direction D. These partition walls 5da1 to 5da3 extend along the rotation axis direction of the fan 7, as shown in FIG. The partition walls 5da1 to 5da3 function to discharge the fan exhaust air along the rotation axis direction of the fan 7.

  The second partition group is partition walls 5dc1 to 5dc3. The partition walls 5dc1 to 5dc3 are located downstream of the partition walls 5da1 to 5da3 in the fan rotation direction D, and are located forward of the rotation axis C1 of the fan 7 and the rotation axis C2 of the saw blade 4 in the cutting direction. These partition walls 5dc1 to 5dc3 are, as shown in FIGS. 22 to 24, deceleration portions 5dc1a to 5dc3a extending along the rotation axis direction of the fan 7, and guide portions extending inclined with respect to the deceleration portions 5dc1a to 5dc3a. 5dc1b to 5dc3b. The deceleration portions 5dc1a to 5dc3a are formed on the fan 7 side, and the guide portions 5dc1b to 5dc3b are formed on the saw blade storage portion 5a side. These partition walls 5dc1 to 5dc3 function to discharge the fan exhaust air to the front side in the cutting direction.

  The third partition wall group is a partition wall 5db positioned between the first partition wall group (partition walls 5da1 to 5da3) and the second partition wall group (partition walls 5dc1 to 5dc3) in the fan rotation direction D. The partition wall 5db is located substantially above the rotational axis C2 of the saw blade 4. As shown in FIG. 21, the partition wall 5db has a speed reducing portion 5dba extending along the rotation axis direction of the fan 7 and a guide portion 5dbb extending inclined with respect to the speed reducing portion 5dba. The deceleration portion 5dba has a length approximately the same as the partition walls 5dc1 to 5dc3 in the direction of the rotation axis of the fan 7.

  The partition guides 5dbb, 5dc1b, 5dc2b, and 5dc3b of the partition walls of the second and third partition groups described above have a partition surface on the upstream side in the fan rotation direction D, and the fan rotation direction of the deceleration portions 5dba and the deceleration portions 5dc1a, 5dc2a, and 5dc3a. D is inclined from the end of the saw blade storage portion 5a side of the deceleration portions 5dba and 5dc1a to 5dc3a to the downstream side of the fan rotation direction D so as to be at an angle of approximately 45 degrees with respect to the partition wall surface on the upstream side of D. Yes. The boundaries of the wall surfaces on the upstream side in the fan rotation direction D between the speed reduction portions 5dc1a to 5dc3a and the guide portions 5dc1b to 5dc3b of the partition walls 5dc1 to 5dc3 are not chamfered in an arc shape but are square.

  Further, the partition walls 5da1 to 5da3, the deceleration portion 5dba of the partition wall 5db, and the deceleration portions 5dc1a to 5dc3a of the partition walls 5dc1 to 5dc3 are radiated around the rotation axis C1 of the fan 7, as shown in FIGS. It is inclined with respect to. This inclination direction is such that the radially outer end portions of the partition walls 5da1 to 5da3, the deceleration portions 5dba and 5dc1a to 5dc3a are located on the upstream side of the fan rotation direction D with respect to the radially inner end portion, and the inclination angle thereof. (An angle θ shown in FIG. 15) is 45 degrees.

  On the downstream side of the partition wall 5dc3 in the fan rotation direction D, a wall 5h is provided between the partition wall 5dc3 and the partition wall 5dc3 for forming a fan wind outlet 5c. The wall surface on the upstream side in the fan rotation direction D of the wall 5h is inclined to the anti-fan rotation direction D side with respect to the radial direction centering on the rotation axis C1 as in the partition wall 5da1 and the like. Further, the end face on the saw blade storage portion 5a side of the guide portion 5dc3b of the partition wall 5dc3 is formed to be parallel to the wall surface of the wall 5h.

  As shown in FIGS. 15 and 26, the partition wall 5d is formed such that when the saw cover 5 is viewed from the front side (when viewed from directly below the paper surface), the other side can be seen from between the adjacent partition walls 5d. . Specifically, a gap is formed between the partition wall 5db and the partition wall 5dc1 in the rotation axis direction of the fan 7 so that they do not overlap. The relationship between the partition wall 5dc2 and the partition wall 5dc3 is the same. With such a configuration, the saw cover 5 can be molded with a mold. This gap is a substantially parallel gap from the inside in the radial direction around the rotation axis of the fan 7 to the outside.

  Further, when the saw cover 5 is viewed from the front side, the end surfaces of the guide portions 5dbb, 5dc1b, and 5dc2b of the partition walls 5db, 5dc1, and 5dc2 on the saw blade storage portion 5a side and the deceleration portions 5dc1a of the adjacent partition walls 5dc1, 5dc2, and 5dc3 The end faces of 5dc2a and 5dc3a on the fan 7 side are formed to be substantially parallel to each other. Therefore, paying attention to the connecting portion between the guide portion 5dbb and the deceleration portion 5dba, the angle formed by the guide portion 5dbb and the deceleration portion 5dba in the radially inward direction, and the guide portion 5dbb and the deceleration portion 5dba in the radially outward direction are The angle is slightly different. The same applies to the relationship between the guide portion 5dc1b and the deceleration portion 5dc1a, the relationship between the guide portion 5dc2b and the deceleration portion 5dc2a, and the relationship between the guide portion 5dc3b and the deceleration portion 5dc3a. With such a configuration, it is possible to partition and form the fan wind discharge passage 5c that discharges the fan discharge wind to the front side in the cutting direction by effectively using the space between the partition walls 5d. The guide portions 5dbb, 5dc1b, and 5dc2b are each formed by a continuous surface.

  As shown in FIGS. 19 and 25 to 27, there is a saw blade on the inner wall of the saw blade storage portion 5 a of the saw cover 5 between the fan air outlet 5 c and the lower end on the front side in the cutting direction of the saw cover 5. A step 5g protruding toward the 4 side is provided. The step 5g is formed at the same time on the back side of the recess 5i when the recess 5i for mounting the laser unit 34 described above is formed, and the saw blade 4 is tilted forward as shown in FIG. Even in the case where the depth is shallow, the lower end of the step 5g is formed at a position located on the rear side in the cutting direction of the opening 6b of the base 6 with respect to the front end in the cutting direction.

  As shown in FIG. 27, the rotational direction head portion of the safety cover 17 can be brought into contact with the step 5g in the saw blade storage portion 5a of the saw cover 5, and the safety cover 17 is shown in FIG. It functions as a rotation restricting means for restricting excessive rotation in the clockwise direction.

  As shown in FIG. 3, since the fan 7 is a centrifugal fan, the fan air blown toward the outside in the radial direction of the fan 7 is blown by the fan guide 19 provided in the housing 2. And flows into the fan wind outlet 5c while turning. The fan exhaust air that has flowed into the fan air outlet 5c collides with the partition walls 5da1 to 5da3, the deceleration portion 5dba of the partition wall 5db, the deceleration portions 5dc1a to 5dc3a of the partition walls 5dc1 to 5dc3, and the upstream surface in the fan rotation direction D to decelerate. Is done. The decelerated fan exhaust air then passes through the fan air exhaust port 5c along the wall surface and is exhausted into the saw blade storage portion 5a. In particular, the fan wind that has been decelerated by colliding with the deceleration portions 5dc1a to 5dc3a is discharged along the wall surfaces of the guide portions 5dc1b to 5dc3b that are continuous with the deceleration portions 5dc1a to 5dc3a.

  At this time, since the partition walls 5da1 to 5da3, the deceleration portions 5dba and 5dc1a to 5dc3a are provided to be inclined with respect to the radial direction around the rotation axis C1 as described above, the fan exhaust air is guided to the guide portions 5dc1b to 5dc1b. While turning inward in the radial direction along the wall surface of 5dc3b, it turns in the fan rotation direction D around the rotation axis C1 and is discharged to the saw blade storage portion 5a side. Since the fan exhaust air is swirled while being exhausted inward in the radial direction, the air volume and the air speed of the fan exhaust air exhausted from the fan air exhaust port 5c to the saw blade storage portion 5a side are outside the radial direction. On the other hand, it is small, and on the radially inner side, it is large. Therefore, while reducing the generation of noise in the radially outward direction, the exhaust air volume can be increased in the radially inward direction to secure the overall fan air volume, and further within the range of the opening 6b as described later. It is possible to increase the amount of fan exhaust air that is exhausted and the amount of fan exhaust air that flows into the groove 6c.

  In order to obtain such an effect, the wall surface on the upstream side in the fan rotation direction D of the partition wall 5d is opposite to the fan rotation direction D with respect to the radial direction about the rotation axis C1 of the fan 7. It is sufficient if it is inclined to the angle. However, in the present embodiment, as shown in FIGS. 20 to 24, the partition surface on the downstream side in the fan rotation direction D (particularly, the fan rotation direction of the deceleration portions 5dc1a to 5dc3a of the partition walls 5dc1 to 5dc3 and the deceleration portion 5dba of the partition wall 5db) Similarly, the wall surface on the downstream side D is also inclined in a direction opposite to the fan rotation direction D with respect to the radial direction around the rotation axis C1 of the fan 7. As a result, the upstream wall surface and the downstream wall surface in the fan rotation direction D are parallel to each other. As a result, a large air passage area of each fan wind outlet 5c can be secured, and the shape of the fan wind outlet 5c between the partition walls 5db, 5dc1 to 5dc3 is inclined with respect to the rotation axis direction of the fan 7. The fan exhaust air can be easily discharged along the shape of the guide portion into the saw blade storage portion 5a and forward in the cutting direction.

  Further, the wall surface on the upstream side in the rotational direction D of the guide portions 5dbb and 5dc1b to 5dc3b is arranged so that the end portion on the saw blade storage portion 5a side is located on the downstream side in the fan rotational direction D with respect to the end portion on the fan 7 side. Since it is formed obliquely with respect to the rotation center axis direction, the fan exhaust air flowing along the guide portions 5dbb and 5dc1b to 5dc3b is discharged into the saw blade storage portion 5a toward the front in the cutting direction. The fan exhaust air discharged in this way is inclined at an angle to the side surface (FIG. 27) of the safety cover 17 in the saw blade storage portion 5a on the fan 7 side or the side surface of the saw blade 4 on the fan 7 side (FIG. 25). While colliding, most of the air flows toward the rotating shaft member 20 as viewed from the rotational axis C1 (FIG. 15) of the fan 7 along the side surface. Thus, a part of the fan exhausted air that flows along the side surface of the safety cover 17 or the saw blade 4 flows toward the range of the opening 6 b of the base 6.

  Here, as the depth of cut increases, the length of contact of the saw blade 4 with the material to be cut in the cutting direction increases, so that the function as a partition wall on the side of the saw blade 4 increases, and the cutting edge of the saw blade 4 The fan flow leaking from the space between the cutting materials to the side opposite to the housing of the saw blade 4 (the front side in FIG. 2 and the left side in FIG. 3) is reduced. Therefore, the fan flow is more effectively directed toward the opening 6 b of the base 6. In particular, in a state where the cutting depth is near the maximum as shown in FIG. 2, the fan exhaust air flows most easily toward the range of the opening 6 b of the base 6. Further, in the state where the safety cover 17 is rotated and the most part is accommodated in the saw cover 5 as shown in FIG. 27 at the maximum cutting depth, the safety cover 17 is discharged into the saw blade accommodating portion 5a. Most of the fan exhausted air collides with the side surface of the safety cover 17 on the fan 7 side and diffuses along the side surface. As described above, the diffused fan exhaust air is exhausted to the front side in the cutting direction, but a part of the fan exhaust air passes between the saw blade storage portion 5a and the safety cover 17 and is behind the saw cover 5 in the cutting direction. Also discharged near the side. As a result, the fan exhaust air is also discharged to the upper surface of the base 6 on the rear side in the cutting direction, and the accumulation of chips at this location is suppressed.

  In addition, a notch inclined surface 17b is formed at one end of the safety cover 17, and even when the leading end of the safety cover 17 is in contact with the step 5g as shown in FIG. The 17 side surfaces are prevented from facing all the fan wind outlets 5c. The fan exhaust air that collides with the side surface of the safety cover 17 and is exhausted along the side surface by the notched inclined surface 17b, or the fan exhaust air that is directly exhausted from the fan air exhaust port 5c, is the opening 6b of the base 6. Flows smoothly toward.

  On the other hand, as shown in FIG. 26, when the saw cover 5 is pivoted upward with the pivot shaft member 20 as a fulcrum to reduce the depth of cut, a part of the fan exhaust air discharged from the fan air exhaust port 5c. Is discharged along the side surface of the saw blade 4 into the range of the opening 6b of the base 6, and the other part of the fan exhaust air collides with the step 5g. The fan exhaust air that has collided with the step 5g flows downward along the step 5g toward the lower side of the saw cover 5, then flows forward in the cutting direction, and is discharged toward the range of the opening 6b of the base 6.

  The fan exhaust air thus discharged into the range of the opening 6b collides with the upper surface of the material to be cut and blows off the chips, and at the time of cutting, the intersection of the cutting edge of the saw blade 4 and the bottom surface 6a of the base 6 (that is, Sediment accumulation around the cutting part) is suppressed. Therefore, the visibility near the cutting portion is improved, the visibility of the marking line before the cutting portion can be improved, and workability can be improved.

  Further, the fan exhaust air that has collided with the upper surface of the material to be cut then flows into the groove 6c along the upper surface of the material to be cut. The width of the groove 6c in the direction of the rotation axis of the saw blade 4 is smaller than the width of the opening 6b, and the groove 6c has an extension line on both side portions of the saw blade 4 that intersects the bottom surface 6a of the base 6. For this reason, the fan exhaust air flowing into the groove 6c exhibits directivity in the cutting direction and is discharged forward from the front end of the base 6 in the cutting direction. This suppresses the accumulation of chips on the workpiece to be cut in front of the base 6 in the cutting direction. In particular, since the groove portion 6c is located on the longitudinal extension line of the saw blade 4, the fan exhaust air flows on the marking line drawn on the upper surface of the material to be cut, and the chips on the marking line are blown off. Workability can be improved. In addition, when cutting with the saw blade 4 inclined, the groove 6c has a sufficient width dimension so that the groove 6c is positioned on the extended line in the longitudinal direction of the saw blade 4. Even if it exists, workability | operativity can be improved similarly. Further, as described above, since the bottom surface of the guide piece 16 (FIG. 14) is formed so as to be substantially flush with the top surface of the groove portion 6c, the fan exhaust air flowing into the groove portion 6c inhibits the guide piece 16. It is possible to blow out from the front end of the base 6 to the front side in the cutting direction without being performed.

  As described above, the boundary of the wall surface on the upstream side in the fan rotation direction D between the deceleration portions 5dc1a to 5dc3a and the guide portions 5dc1b to 5dc3b of the partition walls 5dc1 to 5dc3 is not chamfered in an arcuate shape and has an angular shape. Here, if the boundary portion is chamfered, the areas of the deceleration portions 5dc1a to 5dc3a are reduced, and the fan wind is discharged into the saw blade storage portion 5a through the fan wind discharge port 5c without sufficiently colliding with the deceleration portions 5dc1a to 5dc3a. As a result, there is a problem that fan exhaust wind with high wind speed is generated and noise is generated. However, this problem can be solved by using the square shape as described above.

  Moreover, since the fan wind outlet 5c is partitioned by the plurality of partition walls 5d, the strength of the saw cover 5 can be secured while securing the area of the fan wind outlet 5c. As described above, since all the partition walls 5d are inclined with respect to the radial direction around the rotation axis C1 of the fan 7, the reinforcing effect of the partition walls 5d is reduced. By integrally providing the guide portions 5dbb and 5dc1b to 5dc3b which are inclined with respect to the rotation axis direction, the reinforcing effect of the partition wall 5d can be supplemented.

  For example, when the saw blade 4 is locked during the cutting operation, a load is applied to the saw cover 5 via the bearings 11, 12, and 14 in a direction in which the gear 9 and the pinion gear 8 are separated from each other. In other words, a load acts around the rotation axis C1 of the fan 7 coaxial with the pinion gear 8 and around the rotation axis C2 of the saw blade 4 coaxial with the gear 9. However, as shown in FIG. 25, since the partition walls 5dc1 to 5dc3 having the guide portions 5dc1b to 5dc3b are located at these portions, the reinforcing effect by the partition walls 5d can be exerted in the portion where the load is easily applied, and the life of the saw cover 5 is increased. Can be improved.

  By adopting a configuration in which the fan wind discharge ports 5c are radially arranged around the rotation axis C1 of the fan 7, the fan discharge discharged from any one of the fan wind discharge ports 5c even when the cutting depth is changed. The wind collides with the side surface of the saw blade 4 or the side surface of the safety cover 17 and is discharged along the side surface into the range of the opening 6b, so that workability is improved even in a cutting operation with different cutting depths. Can do.

  In the present embodiment, the speed reduction portions 5dc1a to 5dc3a are provided in the partition walls 5dc1 to 5dc3. However, the fan 6 is provided in the base 6 for the purpose of discharging fan exhaust air within the range of the opening 6b of the base 6. In order to achieve the purpose of discharging the fan exhaust air from the front end of the base 6 to the front side in the cutting direction through the groove 6c, the partition walls 5dc1 to 5dc3 may be formed of only the guide portions 5dc1b to 5dc3b. Further, if the fan exhausted air discharged into the range of the opening 6b passes through the groove 6c and is discharged from the front end in the cutting direction of the base 6 to the front side, the bottom 6a of the base 6 covers the groove 6c. A member may be provided.

  In the present embodiment, a part of the saw cover 5 and the base 6 are connected, and the housing 2 and the base 6 are connected via the saw cover 5, but the present invention is not limited to this structure. A configuration in which the housing 2 and the base 6 are directly connected, or a configuration in which a member that cannot move relative to the housing 2 is connected to the base 6 may be employed.

(7) Fan blowout adjustment mechanism
A fan air blowing adjustment mechanism that adjusts a blower function that suppresses the accumulation of chips on the material to be cut using the fan exhaust air described above will be described with reference to FIGS. 29 and 30. FIG.

  29 and 30, the fan wind blowing adjustment mechanism includes a groove 6f formed in the bottom surface 6a of the base 6, a shielding member 51 in which a long hole 51a is formed and accommodated in the groove 6f, and a long hole. The screw 52 is screwed into the base 6 via 51a. The groove 6f is formed behind the hole 6d in the cutting direction and joins the groove 6c. The groove 6f has substantially the same depth as the groove 6c. The shielding member 51 is slidable between the shielding position shown in FIG. 29 and the non-shielding position shown in FIG. 30 along the groove 6f, and the screw 52 fixes the sliding position of the shielding member 51 to the base 6. ,To release. Therefore, the shielding member 51 is movable within the range of the length of the long hole 51 a, and its position is fixed by tightening the screw 52.

  When the shielding member 51 is fixed at the non-shielding position shown in FIG. 29, as described above, the fan exhaust air discharged into the range of the opening 6b of the base 6 cuts the base 6 through the groove 6c. It is discharged to the front side to prevent the accumulation of chips. On the other hand, when the shielding member 51 is fixed at the shielding position shown in FIG. 30, the groove 6 c is blocked by the shielding member 51, and the fan exhaust air hits the blocking member 51, so it cannot be directed forward in the cutting direction. Therefore, the fan exhaust air is not introduced into the groove 6c, and the fan exhaust air is prevented from blowing forward from the front end of the base 6. As a result, scattering of chips at the front end portion of the base 6 is prevented. In this way, it is possible to selectively prevent the chips from being scattered during the cutting work according to the necessity of the work site. Further, if the shielding member 51 is fixed at an intermediate position between the non-shielding position and the shielding position, it is possible to adjust the blower function capability, that is, the amount of fan exhaust air discharged from the front in the cutting direction of the base 6 through the groove 6c. That is, the blower function can be used while minimizing the scattering of chips.

  A portable electric cutting machine according to a second embodiment of the present invention will be described with reference to FIGS. In the portable electric cutting machine according to the present embodiment, the same members as those in the portable electric cutting machine according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  As shown in FIG. 31 to FIG. 33, the portable electric cutting machine according to the present embodiment has a female screw hole 106 f formed in a portion corresponding to the groove 106 c of the base 106, a shielding member 151, and a penetration of the shielding member 151. A fan wind blowing adjustment mechanism is provided which includes a screw 152 inserted into the hole 151a and screwed into the female screw hole 106f, and a spring 153 provided so as to cover the outer periphery of the screw 152. The shielding member 151 has an L-shaped cross section, and has a support portion extending in the horizontal direction and a shielding portion extending in the vertical direction. The shielding member 151 has substantially the same width as the groove portion 106c in the rotation axis direction of the fan 7 (direction perpendicular to the paper surface of FIG. 31). The spring 153 is interposed between the shielding member 151 and the upper surface of the base 106, and biases the shielding member 151 upward. The base 106 is formed with a through hole 106d through which the shielding portion of the shielding member 151 can pass. By turning the screw 152, the shielding member 152 is moved between the non-shielding position shown in FIG. 31 and the shielding position shown in FIG. Can be slid up and down.

  When the shielding member 152 is fixed at the non-shielding position shown in FIG. 31, the fan exhaust air is exhausted from the front in the cutting direction of the base 106 through the groove portion 106 c formed on the bottom surface 106 a of the base 106. On the other hand, if the shielding member 151 is fixed at the shielding position shown in FIG. 33, the fan exhaust air hits the shielding member 151 and cannot be directed forward in the cutting direction. Therefore, the fan exhaust air is not introduced into the groove 106c, and the fan exhaust air is prevented from blowing forward from the front end of the base 106. Therefore, it is possible to prevent chips from being scattered at the front portion of the base 106 during the cutting operation. Furthermore, if the shielding member 151 is fixed at the adjustment position shown in FIG. 32, the capacity of the blower function, that is, the amount of fan exhaust air discharged from the front in the cutting direction of the base 106 through the groove 106c can be adjusted. Therefore, the blower function can be used while minimizing the scattering of chips.

  A portable electric cutting machine according to a third embodiment of the present invention will be described with reference to FIGS. In the portable electric cutting machine according to the present embodiment, the same members as those in the portable electric cutting machine according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  The portable electric cutting machine according to the present embodiment includes a guide piece 216 with a fan wind blowing adjustment function. As shown in FIGS. 35 and 37, the guide piece 216 has an open surface 216A and a shielding surface 216B. Normally, the guide piece 216 is screwed onto the upper surface of the base 206 with the open surface 216A side facing down as shown in FIG. 18 is detachably attached. However, when the blower function is not used, as shown in FIG. 37, the guide piece 216 can be attached to the upper surface of the base 206 with the shield surface 216B facing downward by turning the guide piece 216 upside down.

  On the open surface 216A side of the guide piece 216, there are a guide portion 216a indicating the cutting edge of the saw blade 4 when the angle of the side surface of the saw blade 4 with respect to the bottom surface 206a of the base 206 is right angle, and the saw blade 4 with respect to the bottom surface 206a of the base 206a. A guide portion 216b is formed that points to the cutting edge of the saw blade 4 when the angle of the side surface is 45 degrees. Protrusions 216a1 and 216b1 extending in the cutting direction front-rear direction are respectively provided on the bottom surfaces of the guide parts 216a and 216b, and a groove 216c is defined between and on both sides of the protrusions 216a1 and 216b1. As shown in FIGS. 34 and 35, when the guide piece 216 is attached to the base 206 with the open surface 216A side down, the projecting portions 216a1 and 216b1 protrude downward to a position substantially coincident with the bottom surface 206a of the base 206. Yes.

  On the other hand, on the shielding surface 216B side of the guide piece 216, a guide portion 216d indicating the cutting edge of the saw blade 4 when the angle of the side surface of the saw blade 4 with respect to the bottom surface 206a of the base 206 is right angle, and a saw with respect to the bottom surface 206a of the base 206 A guide portion 216e is formed that points to the cutting edge of the saw blade 4 when the angle of the side surface of the blade 4 is 45 degrees. The shield surface 216B of the guide piece 216 has substantially the same width as the groove 206c formed in the base 206, and the guide piece 216 is placed on the base 206 with the shield surface 216B side down as shown in FIGS. A shielding portion 216h that protrudes downward to a position that substantially coincides with the bottom surface 206a of the base 206 in a state of being attached to the base 206 is provided.

  In such a configuration, when the guide piece 216 is attached to the base 206 with the open surface 216A side down as shown in FIG. 34, the fan exhaust air is discharged from the front end of the base 206 through the grooves 206c and 216c. On the other hand, when the guide piece 216 is attached to the base 206 with the shielding surface 216B side down as shown in FIG. 34, the fan exhaust air is blocked by the shielding portion 216h and is not discharged from the front end of the base 206. As described above, by selectively changing the mounting surface of the guide piece 216 to the base 206, the above-described blower mechanism can be switched on and off. The guide piece 216 is fixed to the base 206 with the screw 18 using the through hole 216f when the open surface 216A is down and the through hole 216g when the shield surface 216B is down.

  The portable electric cutting machine according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, the fan wind blowing adjustment mechanism in the present embodiment can be used in portable electric circular saws other than those described above. For example, in the portable electric circular saw shown in FIG. 38, an outer peripheral wall 305A is provided near the end of the saw cover 305 on the housing 302 side. A plurality of partition walls 305d are provided at the front end in the cutting direction of the outer peripheral wall 305A, and a fan air discharge port 305c is defined between the adjacent partition walls 305d. The fan wind W blows to the wall (not shown) through the inside of the outer peripheral wall 305A, flows in a direction approaching the side surface of the saw blade 4 along the inclined surface of the wall, and is directed into the range of the opening 306b. The fan wind W is discharged to the outside of the saw cover 305 through the fan wind discharge port 305c. At this time, since the fan air is discharged forward in the cutting direction and within the range of the opening 306b of the base 306, as in the case of the above-described embodiment, a gap between a groove (not shown) communicating with the opening 306b and the upper surface of the material to be cut. And is discharged from the front end surface of the base 306 along the upper surface of the material to be cut. If the above-described fan wind blowing adjustment mechanism is provided on the base 306 of the portable electric circular saw, the same effects as those of the first to third embodiments can be obtained.

  In the portable electric cutting machine of the present invention, the fan wind generated by the rotation of the fan provided for cooling the motor is discharged from the opening at the front end of the base, and the chips accumulate on the marking lines on the material to be cut. By providing a fan wind blowing adjustment mechanism that can be effectively suppressed and prevents the fan wind from being discharged from the opening at the front end of the base, it can also be used at work sites that dislike the scattering of chips during cutting operations.

The perspective view which shows the portable electric circular saw by the 1st Embodiment of this invention. The front view of the portable electric circular saw by 1st Embodiment. Sectional drawing along the III-III line of FIG. The top view of the portable electric circular saw by 1st Embodiment. The right view of the portable electric circular saw by 1st Embodiment. It is a portable electric circular saw by 1st Embodiment, Comprising: The right view which shows the state (tilt angle = 45 degree | times) which inclined the angle of a saw blade side surface and a base bottom face. The left view of the portable electric circular saw by 1st Embodiment. It is a portable electric circular saw by 1st Embodiment, Comprising: The left view which shows the state (tilt angle = 45 degree | times) which inclined the angle of a saw blade side surface and a base bottom face. It is a portable electric circular saw by 1st Embodiment, Comprising: The front view which shows the state which set the cutting depth small. It is a portable electric circular saw by 1st Embodiment, Comprising: The left view which shows the state which set the cutting depth small. The front view which shows the base which comprises the portable electric circular saw by 1st Embodiment. The right view of FIG. The left view of FIG. The bottom perspective view of the portable electric circular saw by 1st Embodiment. The front view which shows the saw cover of the portable electric circular saw by 1st Embodiment. The rear view of the saw cover shown in FIG. BB sectional drawing of FIG. The top view of the saw cover shown in FIG. The CC sectional view taken on the line of FIG. The aa sectional view taken on the line of FIG. Bb sectional view taken on the line of FIG. FIG. 17 is a sectional view taken along line cc in FIG. 16. Dd line sectional drawing of FIG. Ee sectional view taken on the line of FIG. 1 is a perspective view showing a portable electric circular saw according to a first embodiment with a saw blade removed. FIG. 1 is a front view showing a portable electric circular saw according to a first embodiment in a state in which a saw blade is removed and a saw cover (main body) is rotated with a rotation shaft member as a fulcrum with respect to a base. FIG. 3 is a perspective view showing a portable electric circular saw according to the first embodiment with the saw blade removed and the safety cover rotated to a position where the lower end of the safety cover does not protrude from the bottom of the base. The rear view of the portable electric circular saw by 1st Embodiment. It is a portable electric circular saw by 1st Embodiment, Comprising: The bottom view which shows the state which has a shielding member in a non-shielding position. It is a portable electric circular saw by 1st Embodiment, Comprising: The bottom view which shows the state which has a shielding member in a shielding position. Sectional drawing which is a portable electric circular saw by 2nd Embodiment, and shows the state which has a shielding member in a non-shielding position. Sectional drawing which is a portable electric circular saw by 2nd Embodiment, and shows the state which has a shielding member in an adjustment position. Sectional drawing which is a portable electric circular saw by 2nd Embodiment, and shows the state which has a shielding member in a shielding position. Sectional drawing which is a portable electric circular saw by 3rd Embodiment, and shows the state which attached the guide piece to the base with the open surface down. The perspective view which shows the guide piece of the state which made the open surface down. It is portable electric circular saw by 3rd Embodiment, Comprising: Sectional drawing which shows the state which attached the guide piece to the base with the shielding surface down. The perspective view which shows the guide piece of the state which turned down the shielding surface. The principal part cross-sectional right side view of the portable electric circular saw by the modification of this invention.

Explanation of symbols

  1 is a motor, 2 is a housing, 3 is a handle, 4 is a saw blade, 5 is a saw cover, 5a is a saw blade storage portion, 5c is a fan wind outlet, 5d is a partition wall, 5e is e pinion gear storage portion, and 5f is a hole 5g is a step, 5h is a wall, 5i is a recess, 6 is a base, 6a is a base bottom, 6b is an opening, 6c is a groove, 6f is a groove, 7 is a fan, 8 is a pinion gear, 9 is a gear, 10 is an output Shafts 11 and 12 are bearings, 13 is a saw blade fixing member, 14 is a bearing, 15 is a screw, 16 is a guide piece, 17 is a safety cover, 18 is a screw, 20 is a rotating shaft member, 21 is a hinge holding portion, 22 is a pin, 23 is a bevel plate, 24 is a bolt, 25 is a pin, 26 is a link, 27 is a bolt, 28 is a bevel plate, 29 is a bolt, 30 is a protrusion, 31 is a holding hole, 32 is a protrusion, 33 Is the holding hole, 34 is the laser Knit, 35, screw, 51, shielding member, 51a, elongated hole, 52, screw, 106, base, 106c, groove, 151, shielding member, 152, screw, 153, spring, 206, base, 216, guide piece, 216A is an open surface, 216B is a shielding surface, and 216h is a shielding portion.

Claims (5)

A housing that houses a motor that rotationally drives the saw blade;
A saw cover attached to the housing, shaped to cover substantially the upper half of the outer periphery of the saw blade, and having a saw blade storage portion for storing a part of the saw blade;
A base connected to at least one of the housing or the saw cover, having a bottom surface that is slidable on the material to be cut, and having an opening that allows the saw blade to protrude downward from the bottom surface;
In a portable electric cutting machine provided with a fan provided in a housing for cooling the motor and driven to rotate by the motor,
A fan wind passage groove is formed on the bottom surface of the base, connected to the front end in the cutting direction of the opening, communicated with the opening, extends to the front end in the cutting direction of the base, and opens at the front end.
A plurality of partition walls are provided on the wall surface of the saw cover between the housing and the saw blade storage portion, and a fan that directs the fan air in the opening direction of the base and in the cutting direction forward between the adjacent partition walls. A wind outlet is formed, and the fan wind can flow into the fan wind passage groove;
The portable electric cutting machine, wherein the base is provided with a fan wind blowing adjustment mechanism for adjusting blowout of the fan wind from the opening at the front end of the base. On the bottom surface of the base, a guide groove having a depth substantially the same as the depth of the fan air passage groove is formed while joining the fan air passage groove.
The fan air blowing adjustment mechanism includes a shielding member that is slidable along the guide groove between a shielding position that blocks the fan air passage groove and a non-shielding position that opens the fan air passage groove. The portable electric cutting machine according to claim 1. The portable electric cutting machine according to claim 2, wherein the fan air blowing adjustment mechanism further includes a fastening member that fixes and releases the sliding position of the shielding member with respect to the base. A guide hole that joins the fan air passage groove is formed in the base,
The fan air blowing adjustment mechanism includes a shielding member that is slidable along the guide hole between a shielding position that blocks the fan air passage groove and a non-shielding position that opens the fan air passage groove. The portable electric cutting machine according to claim 1, wherein the portable electric cutting machine is configured by an adjustment member that adjusts a sliding position of the shielding member while supporting. The fan wind blowing adjustment mechanism includes a shielding member having a shielding surface and an opening surface, a first state in which the shielding member faces the bottom surface side of the base, and the opening surface as a bottom surface side of the base. And a fixing member that is detachably fixed to the base in a second state directed toward
The shielding surface has substantially the same width as the fan wind passage groove, and a shielding portion that blocks the fan wind passage groove in a state where the shielding member is fixed to the base in the first state. Is installed,
The open surface is formed with a groove that communicates with the fan air passage groove and opens the fan air passage groove when the shielding member is fixed to the base in the second state. The portable electric cutting machine according to claim 1, wherein

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