JP5758792B2 - Circular saw - Google Patents

Description

  The present invention relates to a circular saw having a saw cover for covering a rotary blade.

  In a circular saw that cuts an object to be cut while rotating the rotary blade, the upper peripheral edge of the rotary blade is covered with a saw cover, and therefore the handle is often arranged away from the saw cover in the axial direction of the rotary blade. While holding the handle and pushing the circular saw forward, the workpiece is cut, but the handle is in the position offset in the axial direction from the rotary blade. In this case, a moment with the rotating blade as a fulcrum acts. Therefore, it is necessary for an operator to perform a cutting operation by firmly holding the handle so that the circular saw advances straight. On the other hand, when trying to place the handle on the rotating surface of the rotary blade, the handle will be far away from the center of rotation of the rotary blade, and the handle will move away from the center of gravity of the circular saw, making it difficult to lift a heavy circular saw .

Japanese Patent No. 3611452

  Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a circular saw that is excellent in straight running and easy to carry.

  The present invention has been made to solve the above-described problems. A circular saw according to the present invention includes a saw cover that covers the upper peripheral edge of the rotary blade, and a predetermined distance apart from the saw cover in the axial direction of the rotary blade. A circular saw having a handle disposed thereon, the wall of the saw cover forming the chip discharge passage being locally displaced in a direction away from the handle, and An escape portion for avoiding interference is provided.

  In the circular saw having such a configuration, since the relief portion is formed in the saw cover, even if the handle is disposed at a position close to the saw cover, the handle can be securely grasped to perform the cutting operation.

  In particular, the saw cover is preferably formed with a bulging portion whose wall surface bulges radially outward on the opposite side of the axial direction of the rotary blade with respect to the escape portion. The “opposite side of the rotary blade in the axial direction with respect to the relief portion” means the side of the saw cover when one of the rotary blades in the axial direction is the saw cover side and the other is the handle side. In this configuration, the cross-sectional area of the chip discharge passage can be sufficiently secured by the bulging portion, and the discharge of the chip becomes smooth.

  Furthermore, it is preferable that a swarf discharge port for discharging swarf is formed in the bulging portion. Since the swarf is collected to the bulging portion, the swarf flowing through the bulging portion can be efficiently discharged from the swarf discharge port formed in the bulging portion. Moreover, by forming the chip discharge port in the bulging portion, the chip discharge port can be moved away from the rotary blade, and safety when a finger is mistakenly inserted into the chip discharge port is improved.

  As described above, in the circular saw according to the present invention, since the handle that is separated from the saw cover in the axial direction of the rotary blade can be brought closer to the saw cover as compared with the conventional case, the straightness is improved. Moreover, since the handle can be arranged at a position close to the center of gravity, not behind the circular saw, it is easy to carry.

The top view which shows the circular saw in one Embodiment of this invention. The figure which looked at the circular saw in the same embodiment from one side of the axial direction of a rotary blade. The figure which looked at the circular saw in the same embodiment from the back side. The figure which looked at the circular saw in the same embodiment from the other of the axial direction of a rotary blade. The longitudinal cross-sectional view containing the partial piece cross section of the circular saw in the embodiment. The PP sectional view taken on the line of FIG. The QQ sectional view taken on the line of FIG. The figure which looked at the state which removed the motor from the circular saw in the same embodiment from the other of the axial direction of a rotary blade. The figure which showed the state which removed the guide link from FIG. The figure which looked at an example of the use condition of the circular saw in the embodiment from one side of the axial direction of a rotary blade.

  A circular saw according to an embodiment of the present invention will be described below with reference to FIGS. The circular saw in the present embodiment slides on the upper surface of the object to be cut and the main body 2 provided with the rotary blade 1 rotating around the horizontal axis, and guides the circular saw along the upper surface of the object to be cut. The surface plate 3 is provided.

  The main body 2 includes a motor 4 (see FIG. 5) that is a drive source for rotationally driving the rotary blade 1. The driving force of the motor 4 is transmitted to the support shaft 6 via the gear 5, and the rotary blade 1 is attached to the support shaft 6 so as to rotate integrally. The main body 2 includes a motor case 10 for storing the motor 4, a gear case 11 for storing the gear 5, a handle 12 for gripping a circular saw during a cutting operation, a saw cover 13 covering the upper periphery of the rotary blade 1, and a cutting A slide cover 14 (lower guard) that covers the rotary blade 1 from below when the work is not performed is provided.

  The motor case 10 is screwed to the gear case 11 in the axial direction of the rotary blade 1, and the gear case 11 and the saw cover 13 are integrally formed. The motor case 10, the gear case 11, and the saw cover 13 constitute a main body housing. . In the present embodiment, the gear case 11 and the saw cover 13 are integrally configured, but may be configured separately. Moreover, in this embodiment, the one with the motor 4 in the axial direction of the rotary blade 1 may be referred to as the “motor side” and the other as the “non-motor side”.

  As shown in FIG. 5, a fan 7 is attached to the motor 4, and the motor 4 is cooled by the rotation of the fan 7. A part of the cooling air generated by the fan 7 does not flow toward the rear side, that is, the worker side, but in the lateral direction (rotation) formed in the gear case 11 as shown in FIGS. It flows toward the rotary blade 1 through the through hole 20 in the axial direction of the blade 1.

  The handle 12 is disposed at a predetermined distance from the saw cover 13 on the motor side, which is one side of the rotary blade 1 in the axial direction, and the handle 12 and the saw cover 13 are substantially parallel to each other in plan view. The handle 12 has an upper arm portion 30 that extends obliquely rearward so that the rear side is an upper side from the upper part of the motor case 10 or the gear case 11, and a substantially horizontal direction from the lower rear region of the motor case 10 or the gear case 11 toward the rear side. The extending lower arm portion 31 and the grip portion 32 inclined obliquely rearward from the upper end portion toward the lower end portion so as to connect the tip portions of the upper arm portion 30 and the lower arm portion 31 up and down are generally substantially It is formed in a letter shape. Since the handle 12 is formed in a substantially U shape in this way, a hole 33 in which a hand having the grip portion 32 can be inserted between the grip portion 32 of the handle 12 and the motor case 10 or the gear case 11. Is formed. As shown in FIG. 1, the upper arm portion 30 has a distal end portion with a smaller dimension (width) in the left-right direction, that is, the axial direction of the rotary blade 1 than the base end portion thereof, and the grip portion 32 has a wider width. The width of the distal end portion of the portion 30 is substantially the same, and at least the width of the grip portion 32 is narrower than the width of the proximal end portion of the upper arm portion 30.

  Further, a switch 34 is disposed on the front upper portion of the grip portion 32 so as to protrude forward. The switch 34 is an ON / OFF switch for controlling the operation and stop of the circular saw. The power cord 35 introduced into the inside of the handle 12 from the rear portion of the handle 12, specifically near the boundary between the grip portion 32 and the lower arm portion 31, passes through the switch 34 and passes through the upper arm portion 30 to the motor 4. It is connected.

  Further, an auxiliary handle 36 is extended forward from the base end of the upper arm 30. As shown in FIG. 4, the auxiliary handle 36 extends to the front side so as to incline slightly upward toward the tip portion 36a, and the tip portion 36a has an enlarged vertical dimension. Further, as shown in FIG. 1, the auxiliary handle 36 has a width in the left-right direction that widens toward the distal end portion 36a. The auxiliary handle 36 is located on the front side of the motor case 10, and the tip portion 36a is configured as a gripping portion. For example, while gripping the grip portion 32 of the handle 12 with the right hand, the tip portion 36a of the auxiliary handle 36 can be gripped with the left hand so that the back of the hand faces upward.

  As shown in FIG. 5, the saw cover 13 is formed in a substantially U shape in sectional view so as to cover the upper peripheral edge of the rotary blade 1 from the left and right both sides and the total three sides from the radially outer side. The inside of the saw cover 13 serves as a chip discharge passage for discharging chips from the cutting position to the rear in the circumferential direction as the rotary blade 1 rotates, and the inner surface of the saw cover 13 is a wall surface of the chip discharge passage. Is configured.

  An escape portion 40 for avoiding interference with the hand holding the handle 12 is formed on the left side surface which is the motor side of the saw cover 13. In the drawing, a large number of dots are attached to the relief portion 40. The relief portion 40 is formed so as to locally form a concave portion on the left side surface of the saw cover 13, and by forming the relief portion 40 as shown in FIG. 6 and FIG. The inner surface of the saw cover 13, that is, the wall surface of the chip discharge passage is displaced in the direction away from the handle 12 with respect to the other portions. In FIG. 6, the right hand H that grips the grip portion 32 is indicated by a two-dot chain line, but the relief portion 40 is formed so as to be separated from the right side so as not to interfere with the back of the right hand H. It is formed so as to avoid the base part of the finger that becomes higher (particularly the base part of the middle finger). 4 and 9, line segment A and line segment B indicate locations corresponding to the PP line and the QQ line in FIG. 2, respectively.

  More specifically, the relief part 40 is formed on the motor side when the saw cover 13 is divided into the handle 12 side, that is, the motor side and the opposite motor side, which is the opposite side, with the rotation surface of the rotary blade 1 as the center. ing. The relief portion 40 is formed radially outward from a position corresponding to the outer diameter of the rotary blade 1, and is formed so as to be away from the handle 12 toward the radially outer side. Is formed. And it is farthest from the handle 12 in the vicinity of the extension line of the rotary blade 1 radially outward (near the rotating surface of the rotary blade 1). Further, as shown in FIG. 9, the relief portion 40 is formed along the circumferential direction at the peripheral portion of the saw cover 13, and specifically, within a range of about 90 degrees from the vicinity of the top of the saw cover 13 to the substantially horizontal position on the rear side. Is formed. A transition region 40 a formed so that the wall surface of the saw cover 13 is gradually displaced in the direction away from the handle 12 toward the rear side in the circumferential direction is provided at the end portion on the front side in the circumferential direction of the relief portion 40. . When the escape portion 40 is viewed in the axial direction of the rotary blade 1 as shown in FIG. 9, the width, that is, the radial dimension of the escape portion 40 gradually decreases toward the front side in the transition region 40a. Reference numeral 40a denotes a tapered triangle shape, and the width is substantially constant in a region on the rear side in the circumferential direction from the transition region 40a.

  As shown in FIG. 6, a bulging portion 41 is formed adjacent to the saw cover 13 on the side opposite to the motor of the escape portion 40. The bulging portion 41 is formed by the wall surface of the saw cover 13 bulging outward in the radial direction. Specifically, the bulging portion 41 is formed on the right side of the rotating surface of the rotary blade 1, that is, on the side opposite to the motor. A side surface 41 a on the motor side of the bulging portion 41 is substantially flush with the rotary blade 1 and is a flat surface. As shown in FIGS. 2 and 9, the bulging portion 41 is formed in a range of approximately 90 degrees from the vicinity of the top of the saw cover 13 toward the rear side corresponding to the relief portion 40. In the vicinity of the top of the saw cover 13, the bulging amount of the bulging portion 41 is small. When viewed in the axial direction of the rotary blade 1, the radially outer edge of the bulging portion 41 extends from the vicinity of the top of the saw cover 13 toward the rear while being inclined substantially horizontally or slightly upward, and from the middle. It extends downward while bending with a steep slope. A bending point 41b at which the outer edge in the radial direction of the bulging portion 41 bends downward is formed between the upper arm portion 30 of the handle 12 and the grip portion 32 when viewed in the axial direction of the rotary blade 1 as shown in FIG. Near the boundary, the radially outer edge of the bulging portion 41 extends downward from the bending point 41 b along the grip portion 32.

  The saw cover 13 is formed with a chip discharge port 42 as shown in FIG. The chip discharge port 42 is formed on the right side of the saw cover 13, that is, on the rear side of the side opposite to the motor. The chip discharge port 42 is formed on the outer peripheral side of the saw cover 13, and specifically, is formed so as to open to the bulging portion 41 on the side opposite to the motor. In addition, the chip discharge port 42 is formed vertically long.

  The saw cover 13 covers the upper area of the rotary blade 1 in a fixed manner, while the slide cover 14 variably covers the lower area of the rotary blade 1. That is, the slide cover 14 is configured to rotate within a predetermined angle range along the peripheral edge of the rotary blade 1 about the axis of the rotary blade 1, and the lower portion of the rotary blade 1 is moved along with this rotation operation. Change the area covered. 2 and 5, the slide cover 14 is positioned below the rotary blade 1 in a state where the cutting operation is not performed. At the time of the cutting operation, the slide cover 14 is moved along the peripheral edge of the rotary blade 1 while rotating in the direction opposite to the rotation direction of the rotary blade 1 by pushing the circumferential end portion 14a against the object to be cut and pushing backward. As shown by a two-dot chain line in FIG. 5 to FIG. 7, it is positioned inside the saw cover 13. The slide cover 14 is also substantially U-shaped in cross-section and is stored at a substantially intermediate position in the radial direction between the saw cover 13 and the rotary blade 1.

  The main body 2 is rotatable about a longitudinal pin (not shown) extending in the front-rear direction around the axis in the front-rear direction with respect to the surface plate 3, and the object to be cut can be moved as shown in FIG. The posture can be changed from the state of cutting at a right angle to the state of cutting the object to be tilted by tilting the main body 2 to the right with respect to the surface plate 3. Further, the main body 2 can be pivoted up and down by a predetermined angle around the horizontal axis 51 with respect to the surface plate 3 around the horizontal pin 51 extending in the left-right direction, whereby the depth of cut can be adjusted. . FIG. 1 and the like show a state where the depth of cut is the deepest, but when adjusting the depth of cut, the main body 2 rotates while being guided by a long hole 53 formed in the guide link 52. The guide link 52 is disposed outside the saw cover 13 so as to stand on the left side thereof, that is, on the motor side. An adjustment lever 54 that is operated when adjusting the cut is disposed on the left side of the handle 12. The guide pin 55 guided through the elongated hole 53 of the guide link 52 passes through the handle 12 in the left-right direction, and an adjustment lever 54 is attached to the left end thereof. By loosening the adjustment lever 54, the guide pin 55 55 can travel through the long hole 53 and the cutting depth can be adjusted. By tightening the adjusting lever 54, the guide pin 55 is fixed to the long hole 53 and the cutting depth is fixed.

  In the circular saw configured as described above, for example, the grip part 32 of the handle 12 is gripped with the right hand and pushed forward while the tip part 36a of the auxiliary handle 36 is gripped with the left hand and pressed down. And cutting. Since the handle 12 and the auxiliary handle 36 are disposed relatively close to the heavy motor 4, the handle 12 and the auxiliary handle 36 are not far from the center of gravity of the circular saw, and the cutting operation is stabilized. It is easy to carry around.

  Although the handle 12 is arranged to be separated from the saw cover 13 on the left side, the escape portion 40 is formed on the saw cover 13 so that the grip portion 32 of the handle 12 can be gripped even if the handle 12 is arranged close to the saw cover 13. Therefore, the distance between the rotary blade 1 and the handle 12 can be reduced. As the handle 12 approaches the rotary blade 1, the moment generated by the force pressing the grip portion 32 of the handle 12 is reduced, and the straightness of the circular saw is improved. By improving the straightness of the circular saw, the operator can grip the grip portion 32 with a relatively light force. As a result, the work load is reduced and the operator can easily perform the cutting operation.

  Furthermore, since the bulging portion 41 is formed adjacent to the escape portion 40 on the side opposite to the motor, the cross-sectional area of the chip discharge passage can be sufficiently secured even if the escape portion 40 is formed. In addition, since the transition region 40a is formed at the end portion on the front side in the circumferential direction of the escape portion 40, the swarf is prevented from staying at the end portion on the front side in the circumferential direction of the escape portion 40, via the transition region 40a. It smoothly flows to the rear side in the circumferential direction. Further, as indicated by arrows in FIGS. 6 and 7, the chips are collected from the escape portion 40 to the bulging portion 41 on the side opposite to the motor, and the swarf discharge port 42 passes through the bulging portion 41. Discharged from. Since the chip discharge port 42 is formed in the bulging part 41, the swarf collected by the bulging part 41 and sent can be efficiently discharged.

  Further, at the start of cutting, the other end portion 14b in the circumferential direction of the slide cover 14 is located in a region where the relief portion 40 and the bulging portion 41 are formed as shown in FIG. At the start of the cutting, the chips collide with the other end 14b in the circumferential direction of the slide cover 14, but since the chips are collected at the bulging portion 41, the other end 14b in the circumferential direction of the slide cover 14 is collected. It is possible to reduce the impact of the chips on the chip, and the chips are discharged smoothly. This is the same when the depth of cut is set shallow.

  Furthermore, as indicated by the arrows in FIG. 5, the cooling air that has reached the inside of the saw cover 13 through the through hole 20 hits the slide cover 14, and a part thereof goes radially outward. If a hole for exhausting the cooling air to the outside is formed in the rear part of the motor case 10 or the gear case 11, the cooling air comes out rearward from the hole and directly hits the hand holding the grip part 32. Therefore, a cooling air hole cannot be formed in the rear part of the motor case 10 or the gear case 11. Accordingly, the through hole 20 for sending the cooling air to the inside of the saw cover 13 is mainly formed in the rear part. On the other hand, the rear portion of the saw cover 13 is formed with a bulging portion 41 that bulges radially outward, so that the cooling air that has passed through the through hole 20 hits the slide cover 14 and a part thereof is directed radially outward. However, the influence on the chips passing through the bulging portion 41 is small.

  In addition, since the chip discharge port 42 can be moved away from the rotary blade 1 by forming the chip discharge port 42 in the bulging portion 41, it is assumed that a finger is accidentally inserted into the chip discharge port 42. There is also an advantage that the possibility of a finger hitting the rotary blade 1 is reduced and safety is improved.

  In the present embodiment, the guide link 52 is disposed outside the saw cover 13, but may be disposed inside. When the guide link 52 is disposed inside the saw cover 13, it is preferably disposed on the motor side. In such a case, the guide link is caused by the swelled portion 41 flowing the chip on the side opposite to the motor. The adhesion of cutting powder to 52 is suppressed, and the depth of cut can be adjusted smoothly.

  Further, the shape and position of the relief portion 40 can be appropriately changed, and the bulging portion 41 and the chip discharge port 42 may be omitted.

DESCRIPTION OF SYMBOLS 1 Rotating blade 2 Main body 3 Surface plate 4 Motor 5 Gear 6 Support shaft 7 Fan 10 Motor case 11 Gear case 12 Handle 13 Saw cover 14 Slide cover 14a One end part 14b Other end part 20 Through-hole 30 Upper arm part 31 Lower arm part 32 Grip part 33 Hole 34 Switch 35 Power cord 36 Auxiliary handle 36a Tip portion 40 Relief portion 40a Transition area 41 Swelling portion 41a Side surface 41b Bending point 42 Chip discharge port 51 Horizontal pin 52 Guide link 53 Long hole 54 Adjustment lever 55 Guide pin H Hand

Claims (3)

A circular saw comprising a saw cover that covers the upper peripheral edge of the rotary blade, and a handle that is disposed at a predetermined distance from the saw cover in the axial direction of the rotary blade,
The saw cover has a relief part for avoiding interference with the hand holding the handle so that the wall surface of the saw cover forming the chip discharge passage is locally displaced in a direction away from the handle. Circular saw characterized by.   The circular saw according to claim 1, wherein the saw cover is formed with a bulging portion having a wall surface bulging radially outward on the opposite side in the axial direction of the rotary blade with respect to the escape portion.   The circular saw according to claim 2, wherein a swarf discharge port for discharging swarf is formed in the bulging portion.

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