JP4891105B2 - Portable circular saw - Google Patents

Description

  The present invention relates to a portable circular saw that a user cuts a cutting material by rotating a circular blade (saw blade) while being held in a hand and moving in a cutting direction.

This type of portable circular saw has a base that comes into contact with the upper surface of the cutting material and a circular saw body supported on the upper surface of the base, and has a configuration in which the blade of the circular saw body protrudes toward the lower surface of the base. Yes. In this portable circular saw, the user advances straight in the cutting progress direction, and the blade protruding toward the lower surface of the base is cut into the cutting material and cut.
In this way, the portable circular saw is a device in which the user advances straightly and cuts the cutting material straight.To perform this more accurately than before, this type of portable circular saw uses the side end of the base as a guide surface. The user can easily go straight by sliding it on a separately prepared ruler.
On the other hand, in this linear guide mechanism, the guide surface of the base end and the blade need to be accurately parallel, but the straightness of the blade (blade and The parallelism with the base guide surface may be reduced. Conventionally, in order to maintain this straightness, a mechanism having a mechanism for adjusting the parallelism between the blade and the base guide surface has been provided.
Conventionally, for example, the following Patent Documents 1 to 3 describe techniques related to this parallelism adjusting mechanism. The technique disclosed in Patent Document 1 has a configuration in which a circular saw body is supported at two front and rear positions with respect to a base, and the cutting depth can be adjusted by tilting up and down around a support portion on the front side in the cutting progress direction. In the case of a portable circular saw, the position of the blade with respect to the guide surface at the base blade tip can be adjusted by adjusting the position of the front support portion in the direction perpendicular to the blade surface relative to the base of the circular saw body (direction perpendicular to the cutting progress direction). The parallelism can be adjusted.
Conversely, in the technique disclosed in Patent Document 2, in the case of a portable circular saw whose depth of cut can be adjusted, the base guide surface of the blade is changed by changing the relative position of the support portion on the rear side with respect to the base of the circular saw body. The degree of parallelism can be adjusted.
Furthermore, the technique disclosed in Patent Document 3 supports a guide member arranged along the side edge of the base so that the guide member can be tilted in the direction perpendicular to the blade surface on the front side thereof, and the parallelism of the guide member with respect to the blade is thereby increased. The configuration is adjustable.
JP-A-10-296701 JP-A-9-174502 JP 2002-113701 A

However, the conventional parallelism adjusting mechanisms have the following problems to be solved. The parallelism adjustment mechanism disclosed in Patent Document 1 has a configuration in which a gap is set as an adjustment allowance for changing the relative position in the direction perpendicular to the blade surface in the front support portion (tilting support portion) with respect to the base of the circular saw body. Therefore, there is a problem that the circular saw body is likely to be rattled by this gap.
In addition, the parallelism adjusting mechanism disclosed in Patent Document 2 is a band-plate-like support member that supports the rear side of the blade case, and is a so-called cutting depth adjustment disposed along the rear inner surface of the blade case. The depth guide is displaced in the direction perpendicular to the blade surface to adjust the position (parallelism) of the blade with respect to the base guide surface. However, since the depth guide is supported so as to be tiltable to the left and right in the cutting progress direction with respect to the base in order to enable so-called tilt cutting performed by tilting the blade to the left and right with respect to the cutting progress direction, When the degree is adjusted, there is a problem in that the angle for tilt cutting varies and accurate tilt cutting cannot be performed.
Furthermore, the parallelism adjustment mechanism disclosed in Patent Document 3 has a problem that the position of the side on which the guide member is moved in the direction projecting from the base side end can be adjusted, but cannot be adjusted to the opposite side. .
The present invention has been made to solve these conventional problems. A so-called depth guide is a portable circular saw of a type in which a so-called depth guide is arranged along the back outer side rather than the rear inner surface of the blade case. An object of the present invention is to provide a portable circular saw in which the parallelism of the blade can be adjusted by relatively displacing both at the support portion on the rear side in the cutting progress direction with respect to the base.

For this reason, the present invention is a portable circular saw having the configuration described in each of the claims.
According to the portable circular saw of claim 1, the depth guide for adjusting the depth of cut is disposed along the rear rear side of the blade case, and the parallelism disposed between the depth guide and the blade case. With the adjustment mechanism, the parallelism of the blade with respect to the base guide surface can be adjusted by moving the rear portion of the blade case in the direction perpendicular to the blade surface.
It is not a configuration that displaces the tilting support portion on the front side in the cutting progress direction of the blade case as in the case of the conventional configuration described in Patent Document 1, but a configuration that moves the rear side in the direction perpendicular to the blade surface. It is not necessary to set a backlash as an adjustment allowance on the tilting support portion, and thus the backlash of the cutting machine body does not occur.
Further, since the configuration is not such that the horizontal tilt center of the blade case is displaced as in the case of the conventional configuration described in Patent Document 2, so-called tilt cutting can be performed at an accurate angle.
Further, as in the case of the conventional configuration described in Patent Document 3, it is not based on an adjustment mechanism attached to one side of the base, but by moving the blade case in the direction perpendicular to the blade surface, the blade is parallel to the base guide surface. Since the degree is adjusted, it is possible to cope with the case where the guide surface is set on either side of the base or on both sides.
According to the portable circular saw of claim 2, by adjusting the axial position of the case fixing bolt protruding in the direction perpendicular to the blade surface from the rear rear part of the blade case with respect to the blade case, the amount of protrusion is changed. The position of the blade case in the direction perpendicular to the blade surface with respect to the depth guide is adjusted, so that the parallelism of the blade with respect to the base guide surface can be adjusted.
According to the portable circular saw of the third aspect, the case fixing bolt can be moved to the other side in the axial direction by tightening the adjusting screw against the urging force of the urging member. Conversely, when the adjustment screw is loosened, the case fixing bolt is returned to the one side in the axial direction by the biasing force of the biasing member. From this, it is possible to adjust the position of the case fixing bolt in both axial directions, and thus the parallelism of the blade with respect to the base guide surface in a finer and more precise manner.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a portable circular saw according to this embodiment. The portable circular saw 1 includes a rectangular base 10 that is brought into contact with the upper surface of the cutting material W, and a circular saw body 20 supported on the upper surface side of the base 10.
The portable circular saw 1 also includes a mechanism (parallelism adjusting mechanism 30) for adjusting the parallelism between the blade 21 of the circular saw body 20 and the guide surface 11 set at the side end of the base 10. Yes. The portable circular saw 1 according to the present embodiment is characterized by the parallelism adjusting mechanism 30, and other basic configurations as the portable circular saw are the same as those conventionally known and are particularly changed in the present embodiment. Is briefly described below.
First, the circular saw body 20 includes a circular blade (saw blade) 21 and a blade case 22 that covers the periphery of the upper half of the circular blade (saw blade). Two portions of the blade case 22 are supported with respect to the base 10 in the cutting progress direction front portion and rear portion.
A support portion 22c is provided on the front side of the blade case 22 in the cutting direction (right side in FIG. 1). The support portion 22c is supported so as to be tiltable up and down via a support shaft 13 of a tilt support bracket 12 supported on the upper surface of the base 10. As a result, the blade case 22 is supported so as to be tiltable up and down about the support shaft 13, and thus the circular saw body 20 can be tilted up and down about the support shaft 13. By adjusting the tilt position of the circular saw body 20 around the support shaft 13, the amount of protrusion of the blade 21 to the lower surface side of the base 10 can be changed, and therefore the depth of cut with respect to the cutting material W is adjusted. can do.
A portion of the blade 21 protruding to the lower surface side of the base 10 is covered with an openable / closable cover 28. The cover 28 is rotatably supported by the blade case 22 around the rotation center of the blade 21 and is spring-biased in the closing direction. As shown in FIG. 2, the cover 28 is gradually opened by the movement of the portable circular saw 1 in the cutting progress direction, the blade 21 is exposed, and the exposed portion is cut into the cutting material W.

The rear side (left side in FIG. 1) of the blade case 22 in the cutting progress direction is supported on the base 10 side through the depth guide 15. The depth guide 15 is a strip-shaped member that is curved in an arc shape in the width direction as shown in FIG. 2, and rises upward from the upper surface of the base 10 and is fixed in a state along the rear surface 22 a of the blade case 22. Yes.
The depth guide 15 is provided with a guide hole 15 a that is curved in an arc shape corresponding to the adjustment allowance for the cutting depth of the blade 21. The guide hole 15 a is formed along an arc centering on the support shaft 13 that is the tilt center of the circular saw body 20. The guide hole 15a is provided in a state of penetrating in the direction perpendicular to the blade 21 (blade surface perpendicular direction). In this specification, the direction perpendicular to the blade surface is a direction orthogonal to the cutting progress direction and is used to mean a direction orthogonal to the circular flat blade 21.
A gear case 23 is integrally provided on the back surface 22 a of the blade case 22. A motor case 24 is coupled to the gear case 23. An electric motor 25 as a drive source for the portable circular saw 1 is housed inside the motor case 24. As shown in FIG. 1, the gear case 23 and the motor case 24 are provided so as to protrude rearward from the back surface 22 a of the blade case 22. In this specification, the left side (upper surface side in FIG. 1) of the blade case 22 in the cutting progress direction is the back surface 22a, and the right side (lower surface side in FIG. 1) is the front surface. Therefore, the back surface 22a of the blade case 22 is visible in FIG.
In the vicinity of the joint between the gear case 23 and the motor case 24, a handle portion 26 that is gripped by the user is provided. The handle portion 26 has a loop shape extending from the upper surface of the gear case 23 to the rear surface in the cutting progress direction. When a trigger type switch 27 provided on the inner peripheral side of the handle portion 26 is pulled, the electric motor 25 is activated and the blade 21 rotates. As shown in FIG. 1, the depth guide 15 is disposed between the handle portion 26 and the blade case 22 in a plan view.

A parallelism adjusting mechanism 30 according to this embodiment is provided between the depth guide 15 and the rear side (the left side in FIG. 1) of the back surface 22a of the blade case 22. Details of the parallelism adjusting mechanism 30 are shown in FIG. The parallelism adjusting mechanism 30 uses a structure (tilting position fixing structure) for fixing the cutting depth of the blade 21 with respect to the base 10 and the tilting position of the circular saw body 20 with respect to the base 10. The tilt position fixing structure includes a case fixing bolt 31. By tightening the lever 16 with respect to the case fixing bolt 31 in the locking direction (clockwise direction in FIG. 2), the vertical tilt position of the circular saw body 20 is fixed. The lever 16 is fastened to the screw shaft portion 31 a of the case fixing bolt 31. The case fixing bolt 31 is provided in a cantilevered support state protruding from the back surface 22a of the blade case 22 in the direction perpendicular to the blade surface.
The case fixing bolt 31 includes a support portion 31c, a guide portion 31b, and the screw shaft portion 31a in order from the right side (support side) in FIG. The support portion 31c is inserted so as to be movable in the axial direction (right direction of the blade surface) with respect to the support hole 22b provided in the back surface 22a of the blade case 22. The position of the support portion 31 c in the direction perpendicular to the blade surface with respect to the support hole 22 b is fixed by tightening the fixing screw 32. When the fixing screw 32 is loosened, the axial position of the support portion 31c with respect to the support hole 22b, and thus the protruding amount of the case fixing bolt 31 from the back surface 22a of the blade case 22 can be adjusted.
Moreover, the support part 31c is formed in the hexagonal column shape, and the support hole 22b is formed in the hexagon hole corresponding to this. For this reason, the support part 31c is inserted in the support hole 22b in the state which can move to the one axial direction which cannot be rotated around the axis | shaft.
The guide portion 31 b is inserted through the guide hole 15 a of the depth guide 15. A cylindrical roller 33 is mounted on the outer peripheral side of the guide portion 31b so as to be rotatable about its axis. When the tilt position of the circular saw body 20 is changed by the roller 33, the guide portion 31 b can be smoothly moved along the guide hole 15 a of the depth guide 15. As a result, the tilt position (blade 21) of the circular saw body 20 can be obtained. The operability when adjusting the depth of cut) is ensured.

Spacers 34 and 35 are attached to the guide portion 31b and the screw shaft portion 31a on both sides of the roller 33. Both the spacers 34 and 35 are in contact with both surfaces of the depth guide 15, respectively, and the depth guide 15 is sandwiched between the spacers 34 and 35 in the thickness direction.
The screw shaft portion 31 a protrudes from the back side of the depth guide 15. A nut portion 17 attached to the lever 16 is fastened to the protruding portion. The nut portion 17 is fixed to the rotation base end side of the lever 16 so as not to rotate. A retaining ring 17 a is attached to a portion of the nut portion 17 protruding from the side surface of the lever 16. The retaining ring 17a prevents the lever 16 from falling off the nut portion 17.
When the lever 16 is tightened in the locking direction (the direction in which the nut portion 17 is tightened, the clockwise direction in FIG. 2) with respect to the screw shaft portion 31a, the depth guide 15 is connected to the nut portion 17 of the lever 16 and the case fixing screw. is sandwiched between the step portion between the supporting portion 31c and the guide portion 31b of 31, the tilting position of the blade case 22 for depth guide 15 is tilted position thus saw body 20 is fixed, thus the blade 21 The depth of cut is fixed.
Conversely, by loosening the fixing screw 32 and adjusting the position of the case fixing bolt 31 in the axial direction, the rear side of the blade case 22 can be displaced in the direction perpendicular to the blade surface. Parallelism can be adjusted. By moving the portable circular saw 1 forward in the cutting direction while sliding the guide surface 11 of the base 10 on a separately provided ruler, the cutting operation of the cutting material W by the blade 21 is accurately and parallel along the ruler. Can be performed, and consequently, high-quality cutting work can be efficiently performed.
Further, the portable circular saw 1 according to the present embodiment can adjust the cutting depth of the blade 21 by tilting the blade case 22 up and down, and tilt the blade 21 to the right or left with respect to the cutting progress direction. Thus, a so-called inclined cutting is possible. The support structure for inclining is not particularly required to be changed in the present embodiment, and thus detailed description thereof is omitted. However, the front portion and the rear portion of the blade case are respectively supported by the base 10 via the angular plates. Yes. The front and rear angular plates are supported by the base via rotation axes that are coaxial with each other and parallel to the cutting direction. A front portion (support portion 22 c) of the blade case 22 is supported on the front angular plate via the tilt support bracket 12. A depth guide 15 is attached to the angular plate on the rear side. The rear portion of the blade case 22 is supported by the base 10 via the angular plate and the depth guide 15. The tilting center of the rear angular plate is fixed differently from the conventional configuration described in Patent Document 2.

According to the portable circular saw 1 of the present embodiment configured as described above, the depth for adjusting the depth of cut at the support portion on the rear side of the two support portions before and after the cutting progress direction with respect to the base 10 of the blade case 22. In the portable circular saw 1 in which the guide 15 is arranged not on the inside of the blade case 22 but on the back surface 22a side (left side with respect to the cutting progress direction), the parallelism of the blade 21 with respect to the guide surface 11 of the base 10 Therefore, it is possible to efficiently perform high quality (high accuracy) cutting.
Further, the degree of parallelism is adjusted on the rear side of the blade case 22, and there is no need to provide a gap on the front side. Therefore, rattling as in the conventional configuration described in Patent Document 1 occurs. In this respect, a high-quality cutting operation can be performed efficiently.
Furthermore, since the tilt center of the blade case is not displaced as in the conventional configuration described in Patent Document 2, tilt cutting is performed with an accurate tilt angle by tilting the blade to the left or right of the cutting progress direction. It can be carried out.
In addition, since the position of the blade 21 is directly displaced via the blade case 22, unlike the structure in which an adjustment mechanism is provided on one side of the base as in the conventional structure described in Patent Document 3, the base is different. It is possible to deal with the case where either side is used as a guide surface or both sides are used as guide surfaces.

The embodiment described above can be implemented with various modifications. For example, the configuration in which the position of the blade case 22 in the direction perpendicular to the blade surface with respect to the depth guide 15 and the parallelism of the blade 21 are adjusted by loosening the fixing screw 32 and moving the case fixing bolt 31 directly in the axial direction (first embodiment). However, the same effect can be obtained by the second embodiment shown in FIG.
The parallelism adjusting mechanism 40 according to the second embodiment is different from the parallelism adjusting mechanism 30 according to the first embodiment in the holding structure of the case fixing bolt 41 with respect to the blade case 22. Constituent elements and members that are the same as those in the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted. The case fixing bolt 41 according to the second embodiment includes a support portion 41c, a guide portion 41b, and a screw shaft portion 41a in order from the right side in FIG. Further, a flange portion 41d is integrally provided in the vicinity of the end portion of the guide portion 41b on the support portion 41c side.
The support portion 41c has a hexagonal column shape as in the first embodiment. The support portion 41c is inserted into the support hole 22b of the blade case 22 while being unrotatable about the axis, while being movable in the axial direction. An adjustment screw 42 is fastened to the end surface of the support portion 41c. The displacement of the adjusting screw 42 in the tightening direction (displacement to the left in FIG. 4) is regulated by the regulating plate 44. For this reason, as the adjusting screw 42 is tightened with respect to the support portion 41c, the support portion 41c and thus the case fixing bolt 41 can be moved to the right in FIG. When the case fixing bolt 41 moves to the right side in FIG. 4, the position of the blade case 22 in the direction perpendicular to the blade surface with respect to the depth guide 15 changes.

Further, an urging member 43 is interposed between the flange portion 41 d and the back surface 22 a of the blade case 22. In the present embodiment, a disc spring is used for the biasing member 43. The urging member 43 urges the case fixing bolt 41 in a direction protruding from the back surface 22a of the blade case 22 (leftward in FIG. 4). For this reason, as described above, the tightening operation of the adjustment screw 42 for moving the case fixing bolt 41 to the right side in FIG. 4 with respect to the support portion 41 c is performed against the biasing member 43. On the contrary, when the adjustment screw 42 is loosened with respect to the support portion 41 c, the case fixing bolt 41 is automatically moved by the urging member 43 in the direction of increasing the protruding amount from the back surface 22 a of the blade case 22.
The position of the support portion 41c with respect to the support hole 22b is fixed by the fixing screw 46 as in the first embodiment. Similarly to the first embodiment, a roller 45 is rotatably mounted on the guide portion 41b, so that the case fixing bolt 41 moves smoothly with respect to the guide hole 15a of the depth guide 15. Yes.
The screw shaft portion 41a protrudes from the guide hole 15a of the depth guide 15, and the nut portion 17 of the lever 16 is fastened to the protruding portion. A spacer 47 is sandwiched between the depth guide 15 and the nut portion 17 around the screw shaft portion 41a.

According to the parallelism adjusting mechanism 40 of the second embodiment configured as described above, the adjusting screw 42 is tightened with respect to the support portion 41c or loosened in the state where the fixing screw 46 is loosened. The axial position of the support portion 41c with respect to the support hole 22b, and hence the axial position of the case fixing bolt 41 with respect to the blade case 22, can be changed, whereby the position of the blade case 22 in the direction perpendicular to the blade surface with respect to the depth guide 15 can be changed. By changing, the parallelism of the blade 21 with respect to the base 10 can be adjusted.
In particular, in the case of the second embodiment, the adjustment screw 42 is rotated to adjust the axial position of the case fixing bolt 41, and the loosening direction of the adjustment screw 42 is determined by the biasing force of the biasing member 43. Since the case fixing bolt 41 is configured to move, the axial direction of the case fixing bolt 41 can be adjusted more finely and accurately than in the first embodiment, and thereby the parallelism of the blade 21 can be adjusted more accurately. Fine adjustments can be made.
Also, according to the parallelism adjusting mechanism 40 of the second embodiment, either the case where the right side of the cutting direction of the base 10 is the guide surface 11, the case where the left side is the guide surface, or the case where both are the guide surfaces are used. It can also be applied to.

Further modifications can be made to the first and second embodiments described above. For example, the case where the right side of the cutting direction of the base 10 is the guide surface 11 is illustrated, but the case where the left side edge of the base 10 is the guide surface or both the left and right sides are the guide surfaces is illustrated. The parallelism adjusting mechanisms 30 and 40 can be applied.
In addition to the illustrated parallelism adjusting mechanisms 30 and 40, a configuration in which the parallelism adjusting member described in Patent Document 3 is provided on the edge of the base can be used in combination.
Moreover, in 2nd Embodiment, although the structure which uses a disc spring as the biasing member 43 was illustrated, it is good also as a structure which uses other springs, such as a winding spring, a damper, and elastic rubber.
Further, the configuration in which the support portions 31c and 41c of the case fixing bolts 31 and 41 each have a hexagonal column shape is exemplified, but a support portion having another cross-sectional shape or a key with respect to the support hole 22b of the blade case 22 is used. It is good also as a support part to couple | bond or spline fit.

It is a top view of the whole portable circular saw provided with the parallelism adjustment mechanism concerning a 1st embodiment of the present invention. 1. It is the figure seen from the arrow (2) direction in FIG. 1, Comprising: It is a rear view of the whole portable circular saw. 2 is a cross-sectional view taken along line (A)-(A) in FIG. 2 and is a vertical cross-sectional view of the parallelism adjusting mechanism. It is a longitudinal cross-sectional view of the parallelism adjustment mechanism which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mobile circular saw 10 ... Base 11 ... Guide surface 15 ... Depth guide, 15a ... Guide hole 16 ... Lever 20 ... Circular saw main body 21 ... Blade 22 ... Blade case 22a ... Back surface, 22b ... Support hole, 22c ... Support part 30 ... Parallelity adjustment mechanism (first embodiment)
31 ... Case fixing bolt 31a ... Screw shaft part, 31b ... Guide part, 31c ... Support part 32 ... Fixing screw 33 ... Roller 40 ... Parallelism adjusting mechanism (second embodiment)
41 ... Case fixing bolt 41a ... Screw shaft portion, 41b ... Guide portion, 41c ... Support portion, 41d ... Flange portion 42 ... Adjustment screw 43 ... Biasing member (disc spring)
45 ... Roller 46 ... Fixing screw

Claims (3)

A portable circular saw having a base to be brought into contact with a cutting material, and a cutting machine body supported on the upper surface side of the base and having a circular blade projecting to the lower surface side of the base,
The cutting machine body includes a blade case that covers an upper portion of the blade, and a front portion of the blade case is supported so as to be tiltable up and down with respect to the base, and the cutting depth of the blade can be adjusted. The rear portion of the blade case is supported so as to be vertically changeable with respect to a depth guide for adjusting the depth of cut provided in the base, and the blade is interposed between the depth guide and the back surface of the blade case. A portable circular saw with a parallelism adjusting mechanism for changing the position of the rear part of the case relative to the depth guide in the direction perpendicular to the blade. 2. The portable circular saw according to claim 1, wherein the parallelism adjusting mechanism includes a case fixing bolt protruding from a back surface of the blade case in a direction perpendicular to the blade surface, and the case fixing bolt is guided by the depth guide. It is possible to fix the cutting depth of the blade by inserting the hole, tightening a lever on the screw shaft portion, and fixing the tilt position of the blade case with respect to the depth guide via the case fixing bolt, A configuration in which the parallelism of the blade with respect to the guide surface on the base side can be adjusted by adjusting the position of the case fixing bolt in the axial direction and adjusting the position of the blade case in the direction perpendicular to the blade surface with respect to the depth guide. Portable circular saw. The portable circular saw according to claim 2, wherein the case fixing bolt is urged to one side in the axial direction by an urging member, and moves to the other side in the axial direction against the urging force. A portable circular saw with an adjusting screw.

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