JP2013071218A - Portable cutting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of cutting work by automatically opening an opening/closing cover when a target member is cut to reduce a burden on a user.SOLUTION: Closer to the introduction side of wood W than the saw blade 13 of a housing 11, there is provided a movable member 21 that is protruded to the other side of a base 16 in the noncontact state of the wood W and moved to one side of the base 16 by contacting with wood W. Between an opening/closing cover 18 and the movable member 21, there is provided a string-shaped member 23 for rotating the opening/closing cover 18 in an opening direction by moving the movable member 21. The movable member 21 is moved by contacting with the wood W, and through the string-shaped member 23, the opening/closing cover 18 is rotated in the opening direction. Thus, the opening/closing cover 18 is automatically rotated in the opening direction by contacting with the wood W irrespective of a user's operation, and the efficiency of cutting work is improved while reducing the burden on the user.

Description

  The present invention relates to a portable cutting machine including a saw blade that is rotationally driven by an electric motor, and an open / close cover that is rotatably provided in a housing and covers the saw blade when not in use and exposes the saw blade when in use.

  2. Description of the Related Art Conventionally, as a portable cutting machine that cuts wood or the like as a workpiece, for example, a portable cutting machine including a saw blade (tip saw) that is rotationally driven by an electric motor is known. A portable cutting machine equipped with such a saw blade has a housing with a handle portion gripped by a user. An electric motor (electric motor) is accommodated in the housing, and a base that is slidably contacted along a plane of wood or the like is provided in the lower part of the housing. A saw cover that covers one side (upper side) of the base of the saw blade is integrally provided in the housing. The housing is provided with an openable / closable cover that covers the other side (lower side) of the base of the saw blade.

  The base is provided so as to be rotatable with respect to the housing, and the angle between the base and the saw blade is adjusted by rotating the base, thereby adjusting the cutting angle of the saw blade, that is, the cutting angle of wood or the like. I am doing so. Thus, by adjusting the angle formed by the base and the saw blade, a corner portion of wood or the like, that is, a cut portion can be cut off at a predetermined angle (for example, 45 °).

  The opening / closing cover covers the saw blade when the portable cutting machine is not used, thereby preventing the user or the like from accidentally touching the saw blade when carrying the portable cutting machine. When the wood or the like is cut, the end of the wood or the like comes into contact with the opening / closing cover, so that the opening / closing cover gradually opens greatly as the cutting operation of the wood or the like proceeds. In this way, the opening / closing cover is rotated with respect to the housing by contact with wood or the like and gradually moves to the saw cover side, whereby the other side of the saw blade base is gradually exposed.

  As such a portable cutting machine (circular saw), for example, a technique described in Patent Document 1 is known. The technique described in Patent Document 1 is provided with a safety cover (open / close cover) that is rotatable with respect to a gear cover (housing), and further provided with an open / close lever that can be pressed by a user. Then, the circular saw blade (saw blade) is rotationally driven by operating the switch by the user, and the safety cover is slightly opened by pressing the open / close lever in that state. Thereafter, as the cutting work of wood or the like proceeds, the safety cover is gradually opened.

JP 58-087004 A (FIGS. 2 and 3)

  However, according to the technique described in Patent Document 1 described above, the user presses the open / close lever to the opposite side while holding the handle portion of the portable cutting machine and pressing the switch forward. There was a need. That is, the operability is poor because the user manually operates the open / close lever. In addition, since the operation direction of the switch and the open / close lever is opposite, the gripping force for gripping the handle portion of the user may become unstable. If the gripping force becomes unstable, problems such as the inability to accurately guide the saw blade of a portable cutting machine to a cutting site such as wood, etc., will occur, which makes it difficult to perform cutting work that requires high precision, and consequently cutting work. This may cause problems such as lowering the efficiency.

  An object of the present invention is to provide a portable cutting machine that automatically opens an opening / closing cover when cutting a workpiece, thereby reducing the burden on the user and improving the efficiency of cutting work. It is to provide.

  A portable cutting machine according to the present invention includes a housing, an electric motor accommodated in the housing, a saw blade that is rotationally driven by the electric motor to cut the workpiece, and is provided on the housing and slides on the workpiece. A base that is in contact with, a saw cover that is provided integrally with the housing and that covers one side of the base of the saw blade, and a rotary cover that is rotatably provided on the housing and covers the other side of the base of the saw blade. In a portable cutting machine provided with an open / close cover, the open / close cover pivots to operate by contact with the workpiece on the introduction side of the workpiece relative to the saw blade of the housing to rotate the open / close cover It has the means.

  In the portable cutting machine according to the present invention, the opening / closing cover rotation means is provided on the introduction side of the processed member with respect to the saw blade of the housing, and the other side of the base in a non-contact state of the processed member And a movable member that moves to one side of the base by the contact of the workpiece and the opening / closing cover and the movable member, and is rotated in a direction to open the opening / closing cover by the movement of the movable member. And a cover operating member to be moved.

  The portable cutting machine according to the present invention is characterized in that the cover operating member is a string-like member, and the string-like member is rotated in the opening direction by pulling the opening / closing cover by the movement of the movable member.

  The portable cutting machine according to the present invention is characterized in that the cover operating member is a rod-shaped member, and the rod-shaped member is rotated in a direction to open the opening / closing cover by moving the movable member.

  In the portable cutting machine according to the present invention, the movable member is provided with a pair of opposing wall portions, and when the movable member moves to one side of the base, the side surfaces of the saw blade are covered with the opposing wall portions. It is characterized by.

  The portable cutting machine of the present invention is characterized in that the movable member is formed of a transparent material.

  According to the portable cutting machine of the present invention, an opening / closing cover rotating means is provided that operates by contact with the workpiece on the introduction side of the workpiece relative to the saw blade of the housing and rotates the opening / closing cover. Thereby, it can rotate in the direction which opens an opening-and-closing cover automatically by contact with a member to be processed. Therefore, it is not necessary for the user to manually rotate the opening / closing cover, so that operability can be improved.

  According to the portable cutting machine of the present invention, the opening / closing cover rotation means is provided on the introduction side of the workpiece from the saw blade of the housing, and protrudes to the other side of the base in a non-contact state of the workpiece. A movable member that moves to one side of the base by the contact of the workpiece, and a cover operation member that is provided between the opening and closing cover and the movable member and rotates in the opening direction by moving the movable member. . Thereby, a movable member moves by contact of a to-be-processed member, and it can rotate to the direction which opens an opening-and-closing cover via a cover operation member. Therefore, the opening / closing cover can be automatically rotated in the direction of opening the opening / closing cover by the contact of the workpiece regardless of the user's operation, and the gripping force of the handle portion by the user is prevented from becoming unstable. Can be accurately guided to the cut portion of the workpiece. Therefore, it is possible to improve the efficiency of the cutting work while reducing the burden on the user.

  According to the portable cutting machine of the present invention, the cover operating member is a string-like member, and the string-like member pulls the opening / closing cover by the movement of the movable member and rotates it in the opening direction. The cover operation member can be formed at a relatively low cost without increasing.

  According to the portable cutting machine of the present invention, the cover operating member is a rod-shaped member, and the rod-shaped member presses and opens the opening / closing cover by the movement of the movable member, so that the opening / closing cover is rotated by the rigidity of the rod-shaped member. The opening can be set with high accuracy.

  According to the portable cutting machine of the present invention, the movable member is provided with a pair of opposing wall portions, and when the movable member moves to one side of the base, each opposing wall portion covers the side surface of the saw blade. It is possible to prevent chips from being scattered during the cutting operation of the workpiece by the wall portion.

  According to the portable cutting machine of the present invention, since the movable member is formed of a transparent material, it is possible to easily confirm the cutting position of the workpiece by the saw blade even if the movable member covers the side surface of the saw blade. it can.

It is a top view showing this side of a circle concerning a 1st embodiment of the present invention. It is the top view which looked at the circular saw of FIG. 1 from upper direction. It is sectional drawing which follows the AA line of FIG. 2 explaining a timber introduction | transduction process. It is explanatory drawing explaining the automatic opening process of an opening-and-closing cover. It is explanatory drawing explaining the opening process by the wood of an opening-and-closing cover. It is explanatory drawing explaining the automatic closing process of an opening / closing cover. It is explanatory drawing corresponding to this FIG. 3 (wood introduction process) of the circle which concerns on 2nd Embodiment. It is explanatory drawing corresponding to this FIG. 4 (automatic opening process) of the circle which concerns on 2nd Embodiment. It is explanatory drawing corresponding to this FIG. 5 (opening process by wood) of the circle | round | yen which concerns on 2nd Embodiment. It is explanatory drawing corresponding to this FIG. 3 (wood introduction process) of the circle which concerns on 3rd Embodiment. It is explanatory drawing corresponding to this FIG. 4 (automatic opening process) of the circle which concerns on 3rd Embodiment.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view showing this side face of a circle according to the first embodiment of the present invention, FIG. 2 is a plan view of the circular saw of FIG. 1 as viewed from above, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2, FIG. 4 is an explanatory view for explaining an automatic opening process of the opening / closing cover, FIG. 5 is an explanatory view for explaining an opening process of the opening / closing cover with wood, and FIG. Explanatory drawing explaining the automatic closing process of a cover is each represented.

  As shown in FIGS. 1 to 3, a circular saw 10 as a portable cutting machine is a power tool for cutting a wood W as a workpiece, and the circular saw 10 is a housing that forms an outline thereof. 11 is provided. The housing 11 is formed in a predetermined shape from a resin material such as plastic, and the housing 11 includes a motor housing portion 11a, a handle portion 11b, and a saw cover 11c. And these motor accommodating part 11a, the handle | steering-wheel part 11b, and the saw cover 11c are each integrated by the fastening screw etc. (not shown).

  As shown in FIG. 2, an electric motor 12 as an electric motor is accommodated in the motor accommodating portion 11a. The electric motor 12 is an electric motor with a brush, and by supplying a driving current from a power cord PC to a coil (none of which is shown) wound around an armature via a brush, a rotating shaft 12a (see FIG. 1). Rotates at a predetermined rotational speed / rotational torque. A saw blade (chip saw) 13 for cutting the wood W is fixed to the rotary shaft 12a so as to be integrally rotatable, whereby the saw blade 13 rotates together with the rotary shaft 12a. The saw blade 13 rotates in the counterclockwise direction (in the direction of arrow R1 in the figure) as shown in FIG.

  As shown in FIGS. 1 and 3, the handle portion 11 b is provided with a switch 14 that is operated by a user so that a drive current is supplied to the electric motor 12 by operating the switch 14 to be retracted. It has become. In addition, a light switch 15 is provided in front of the switch 14 of the handle portion 11b (right side in the figure), and by operating the light switch 15, illumination for illuminating the front side of the circular saw 10 ( (Not shown) lights up. Thereby, the cutting work of the timber W can be reliably performed even in a dimly lit house under construction or the like.

  As shown in FIGS. 1 and 3, on the lower side of the housing 11, that is, on the wood W side, a base 16 that slides on the plane of the wood W and guides the movement of the circular saw 10 in the cutting direction is provided. . The base 16 is provided so as to be rotatable with respect to the housing 11, and the angle formed between the base 16 and the saw blade 13 can be adjusted by rotating the base 16 with respect to the housing 11. Specifically, by adjusting an inclination adjusting member 17 provided between the base 16 and the housing 11, the angle formed by the base 16 and the saw blade 13 can be arbitrarily adjusted (for example, 45 °). . Thereby, the corner | angular part of the timber W can be cut off by arbitrary angles.

  The inclination adjusting member 17 also serves as a cutting depth adjusting mechanism that adjusts the amount of protrusion of the saw blade 13 from the bottom surface of the base 16. That is, the front end side (right side in the figure) of the saw cover 11c is connected to the inclination adjusting member 17 and a pin (not shown in detail), and the rear part (left side in the figure) of the saw cover 11c is centered on the pin. The amount of protrusion of the saw blade 13 from the bottom surface of the base 16 can be changed by rotating with respect to the base 16 (clockwise in FIG. 1). Thereby, not only the wood W can be cut, but also grooves can be formed in the wood W.

  As shown in FIG. 1, the saw cover 11c is formed in a substantially arc shape and has a substantially U-shaped cross section, so that the saw cover 11c is on one side of the base 16 of the saw blade 13 (see FIG. 1). It covers the periphery of the middle upper side). In addition, the saw cover 11c is provided with an arrow display D which serves as a mark of the rotation direction of the saw blade 13, so that the rotation direction of the saw blade 13 can be easily changed when the saw blade 13 is replaced. Therefore, work efficiency can be improved.

  As shown in FIGS. 1 and 3, on the lower side of the housing 11, that is, on the wood W side, an opening / closing cover 18 that covers the periphery of the other side (lower side in the drawing) of the saw blade 13 is provided. . The open / close cover 18 is formed in a substantially arc shape like the saw cover 11c, and has a substantially U-shaped cross section. The opening / closing cover 18 is formed of a resin material such as plastic, and is provided so as to be rotatable with respect to the housing 11 about the rotation shaft 12a. The opening / closing cover 18 is formed to have a slightly smaller diameter than the saw cover 11c, so that the opening / closing cover 18 can enter the inside of the saw cover 11c when rotated in the opening direction (see FIG. 5). ).

  On the right side of the opening / closing cover 18 in the drawing, that is, on the introduction side of the wood W, a contact arc portion 18a with which the end of the wood W comes into contact is formed. The rotation in the direction of arrow R2 in FIG. 1 can be smoothly performed without being caught. Here, the opening angle of the opening / closing cover 18 when the circular saw 10 is not used, that is, the angle α ° formed by the contact arc portion 18a side of the opening / closing cover 18 and the base 16 under the state shown in FIG. (When not in use) is set to approximately 40 °. Thereby, when the circular saw 10 is not used, the user or the like is prevented from touching the saw blade 13 by mistake.

  As shown in FIG. 3, the housing 11 is provided with a cover operation mechanism (open / close cover rotating means) 20 that automatically opens the open / close cover 18 by contact with the wood W. The cover operation mechanism 20 is provided on the housing 11. The opening / closing cover 18 is rotated by contact with the wood W on the introduction side of the wood W with respect to the saw blade 13.

  The cover operating mechanism 20 includes a movable member 21 provided closer to the wood W introduction side than the saw blade 13 of the housing 11 and a hook portion provided integrally in the vicinity of the rotation center C (rotation shaft 12a) of the opening / closing cover 18. 22. In addition, a string-like member 23 is provided between the movable member 21 and the hook portion 22 as a cover operation member that transmits an operation force transmitted from the wood W to the movable member 21 to the hook portion 22. A tension spring 24 for pulling the openable opening / closing cover 18 in the closing direction is provided between the housing 11 and the housing 11. As described above, the cover operating mechanism 20 includes the movable member 21, the hook portion 22, the string-like member 23, and the tension spring 24.

  The movable member 21 is formed in a substantially L shape by a resin material such as plastic, and the central portion of the L shape is rotatably connected to the housing 11 via a rotation pin P. A contact portion 21a that is formed in a substantially fan shape and is in contact with the wood W is provided below the rotation pin P of the movable member 21 in the drawing, and is above the rotation pin P of the movable member 21 in the drawing. Is provided with a substantially bar-shaped pulling portion 21b to which one end side of the string-like member 23 is attached and pulls the string-like member 23.

  And the contact part 21a which comprises the movable member 21 protrudes in the other side (lower side in a figure) of the base 16 in the non-contact state (state of FIG.1, 3, 6) of the timber W, and contact ( The state moves to one side (upper side in the figure) of the base 16 according to the state of FIGS. Thereby, when the timber W contacts the contact part 21a, the tension part 21b pulls the string-like member 23, and the opening / closing cover 18 is opened. Here, the opening degree of the opening / closing cover 18 by the cover operating mechanism 20 is set to an angle β ° between the solid line position and the two-dot chain line position as shown in FIG. 1 (β ° <α °). Specifically, the angle β ° is set to approximately 20 °. Therefore, when the cover operating mechanism 20 is operated by the wood W, the opening / closing cover 18 is totaled before the contact between the wood W and the opening / closing cover 18. It opens at an opening of α ° + β ° (approximately 60 °).

  The other end side of the string-like member 23 is attached to the hook portion 22, and the hook portion 22 is on the upper side of the rotating shaft 12 a in the drawing, that is, with the opening / closing cover 18 closed as shown in FIG. It arrange | positions rather than the axis | shaft 12a at the handle | steering-wheel part 11b side. When the hook portion 22 is pulled by the string-like member 23 and rotates to the right side in the drawing, the opening / closing cover 18 is rotated in the opening direction (clockwise). On the other hand, when the hook portion 22 is pulled by the tension spring 24 and rotated to the left side in the drawing, the opening / closing cover 18 is rotated in the closing direction (counterclockwise).

  Here, as the string-like member 23, a twisted synthetic fiber having flexibility and strength and having excellent durability, for example, a polyethylene twisted string or the like is used. Thereby, the string-like member 23 can be formed in a lightweight and inexpensive manner, and an increase in the weight of the circular saw 10 can be suppressed. Further, the elastic force of the tension spring 24 is set to a minimum elastic force necessary for closing the opening / closing cover 18, thereby suppressing the movement of the movable member 21 and preventing the wood W from being damaged. To do.

  Next, the operation of the circular saw 10 configured as described above, in particular, the operation of the cover operation mechanism 20 will be described in detail with reference to the drawings.

[When not using circular saw]
When the circular saw 10 is not used, the switch 14 is in an off state, so that the electric motor 12 is stopped and the saw blade 13 is also in a stopped state. At this time, the wood W is not in contact with the opening / closing cover 18, and the wood W is not in contact with the contact portion 21 a of the movable member 21 constituting the cover operating mechanism 20. Accordingly, the hook portion 22 is pulled by the tension spring 24, and the opening / closing cover 18 is closed, that is, the opening degree α ° shown in FIGS. Accordingly, the opening / closing cover 18 covers the periphery of the saw blade 13 on the other side of the base 16, and prevents the user or the like from touching the saw blade 13 by mistake.

[Wood introduction process]
When the wood W is cut with the circular saw 10, first, the inclination adjusting member 17 is adjusted in order to adjust the cutting angle and the cutting depth of the wood W. Thereby, for example, the angle formed by the base 16 and the saw blade 13 is adjusted to 20 ° so that the corner portion of the wood W can be cut off at 20 °. Next, as shown in FIG. 3, the front side (right side in the figure) of the base 16 is placed on the wood W, and the saw blade 13 and the location where the wood W is to be cut are aligned under this state. Do. Then, the user operates the switch 14 to turn the circular saw 10 on, whereby the electric motor 12 is driven to rotate and the saw blade 13 is also driven to rotate. Thereafter, the end of the wood W comes into contact with the movable member 21 by moving the circular saw 10 in the direction of arrow M (cutting direction) by the user.

[Automatic opening process]
When the circular saw 10 is further moved in the cutting direction, the end portion of the wood W comes into contact with the contact portion 21a of the movable member 21. Then, the movable member 21 rotates about the rotation pin P in the arrow R3 direction, and the contact portion 21a moves to one side (upper side in the figure) of the base 16 as shown in FIG. As a result, the string-like member 23 is pulled and the hook portion 22 is rotated to the right side in the figure, and as a result, the opening / closing cover 18 is rotated in the direction of opening from the broken line position toward the solid line position as indicated by an arrow R4. At this time, since the user only holds the handle portion 11b and operates the switch 14, the gripping force does not become unstable as before.

  Here, as shown in FIG. 1, since the opening degree of the opening / closing cover 18 is largely opened with a total opening degree of α ° + β ° (approximately 60 °) before the cutting of the wood W, the inclination adjusting member 17 is opened. Even if the angle formed by the base 16 and the saw blade 13 is adjusted to a large angle such as 45 ° on the front side in the figure, the opening / closing cover 18 is almost independent of the shape (thickness, etc.) of the wood W. Can be opened easily.

[Opening process using wood]
When the circular saw 10 is further moved in the cutting direction, the wood W is gradually cut by the saw blade 13 so that the end of the cut wood W comes into contact with the contact arc portion 18a of the opening / closing cover 18. become. As a result, this time, the wood W gradually rotates in a direction to directly open the opening / closing cover 18. After that, as indicated by an arrow R5 in FIG. 5, the open / close cover 18 is rotated so as to enter the saw cover 11c and is fully opened, and the other side (lower side in the figure) of the base 16 of the saw blade 13 is exposed. Is done. Thereby, the cutting operation of the timber W is continuously performed by moving the circular saw 10 in the direction of the arrow M.

  Here, since the string-like member 23 has flexibility, it is loosened as shown in the figure. As a result, only the elastic force of the tension spring 24 acts on the opening / closing cover 18 as a rotational resistance force, thereby suppressing the rotational resistance force from becoming larger than necessary.

[Automatic closing process]
When the wood W is cut by the circular saw 10, the end portion of the wood W is positioned on the rear side (left side in the figure) of the base 16 as shown in FIG. Then, the contact between the wood W and the opening / closing cover 18 is released, and the opening / closing cover 18 is pulled by the tension spring 24. Then, the hook portion 22 is rotated to the left in the drawing by the elastic force of the tension spring 24, and as a result, the opening / closing cover 18 is rotated in the closing direction as indicated by an arrow R6. As a result, the other side of the saw blade 13 than the base 16 is covered with the opening / closing cover 18, and the circular saw 10 returns to the state when not in use. Thereafter, the user operates the switch 14 to turn off the circular saw 10, stops the electric motor 12, and stops the saw blade 13.

  As described above in detail, according to the circular saw 10 according to the first embodiment, the wood W is closer to the introduction side of the wood W than the saw blade 13 of the housing 11, and the other side of the base 16 is in the non-contact state of the wood W. A movable member 21 that protrudes and moves to one side of the base 16 by contact with the wood W is provided, and a string that rotates the opening / closing cover 18 in the opening direction by the movement of the movable member 21 between the opening / closing cover 18 and the movable member 21. A shaped member 23 was provided.

  Thereby, the movable member 21 is moved by contact with the wood W and can be automatically rotated in the direction of opening the opening / closing cover 18 via the string-like member 23. Accordingly, it is not necessary for the user to manually rotate the opening / closing cover 18, so that the operability can be improved. Further, since the opening / closing cover 18 can be automatically rotated in the opening direction by the contact with the wood W regardless of the user's operation, it is possible to prevent the gripping force of the handle portion 11b by the user from becoming unstable, and consequently The saw blade 13 can be accurately guided to the cutting position of the wood W. Therefore, it is possible to improve the efficiency of the cutting work while reducing the burden on the user.

  Further, according to the circular saw 10 according to the first embodiment, the string-like member 23 is used, and the opening and closing cover 18 is pulled and rotated by the movement of the movable member 21. The cover operating mechanism 20 can be formed at a relatively low cost without increasing the weight of the cover 10.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the part which has the same function as 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted.

  FIG. 7 corresponds to FIG. 3 (wood introduction process) of the circle according to the second embodiment, and FIG. 8 corresponds to FIG. 4 (automatic opening process) of the circle according to the second embodiment. FIG. 9 is an explanatory view corresponding to FIG. 5 (opening process using wood) of a circle according to the second embodiment.

  As shown in FIGS. 7 to 9, the circular saw 30 according to the second embodiment has a substantially parallelogram shape in place of the movable member 21 of the cover operation mechanism 20 as compared with the first embodiment. The difference is that the formed movable member 31 is employed, and that a rod-like member 32 having rigidity made of steel is employed instead of the string-like member 23 of the cover operating mechanism 20.

  As shown in FIG. 7, the movable member 31 is formed in a substantially parallelogram shape, and the first corner portion 31 a is rotatably connected to the housing 11 via the rotation pin P. One end side of a rod-like member 32 as a cover operation member is rotatably connected to the right side and the upper side in the drawing from the rotation pin P of the movable member 31. A second corner 31b is formed on the right side and the lower side of the movable member 31 in the drawing with respect to the rotation pin P, and the wood W is in contact with the second corner 31b. . And when the edge part of the timber W contacts the 2nd corner | angular part 31b, the movable member 31 will rotate to the arrow R7 direction (counterclockwise direction) centering | focusing on the rotation pin P. FIG. Thereby, the rod-shaped member 32 moves to the rear side (left side in the figure) of the circular saw 30.

  A concave groove 33 is integrally provided in the vicinity of the rotation center C (rotary shaft 12a) of the opening / closing cover 18. The concave groove 33 is arranged on the lower side of the rotary shaft 12a in the drawing, that is, on the opposite portion of the hook portion 22 sandwiching the rotary shaft 12a, and the other end side of the rod-shaped member 32 can enter the concave groove 33. That is, the rod-shaped member 32 moves to the rear side of the circular saw 30 with the other end side of the rod-shaped member 32 entering the concave groove 33 so that the opening / closing cover 18 rotates in the opening direction. It has become. Further, when the opening / closing cover 18 is gradually rotated in the opening direction by the wood W, the other end side of the rod-shaped member 32 is separated from the concave groove 33.

  Next, the operation of the circular saw 30 configured as described above, in particular, the operation of the cover operation mechanism 20 will be described in detail with reference to the drawings.

[Automatic opening process]
As shown by an arrow M in FIG. 7, when the circular saw 30 is moved in the cutting direction, the end portion of the wood W comes into contact with the second corner portion 31 b of the movable member 31. Here, in order to make the movable member 31 easier to move, the second saw 31b and the wood W may be brought into contact with each other from the vertical direction in the drawing so that the circular saw 30 is slightly lifted. When the wood W comes into contact with the second corner 31b, the movable member 31 rotates about the rotation pin P in the direction of the arrow R7, and the movable member 31 is located on one side of the base 16 (upper side in the figure) as shown in FIG. ) As a result, the rod-like member 32 moves to the rear side of the circular saw 30 with the other end of the rod-like member 32 entering the concave groove 33, and the rod-like member 32 presses the opening / closing cover 18 to open. Turn to. As a result, as shown by the arrow R8, the opening / closing cover 18 rotates in a direction to open from the broken line position toward the solid line position.

[Opening process using wood]
When the circular saw 30 is further moved in the cutting direction, the wood W is gradually cut by the saw blade 13 so that the end of the cut wood W comes into contact with the contact arc portion 18a of the opening / closing cover 18. become. As a result, this time, the wood W gradually rotates in a direction to directly open the opening / closing cover 18. Thereafter, as shown by an arrow R9 in FIG. 9, the open / close cover 18 is rotated so as to enter the saw cover 11c and is fully opened, and the other side (lower side in the figure) of the base 16 of the saw blade 13 is exposed. Is done. Thereby, the cutting work of the timber W is continuously performed by moving the circular saw 30 in the direction of the arrow M.

  Here, as the opening / closing cover 18 rotates in the opening direction, the other end side of the rod-shaped member 32 is separated from the groove 33 as shown in FIG. As a result, only the elastic force of the tension spring 24 acts on the opening / closing cover 18 as a rotational resistance force, thereby suppressing the rotational resistance force from becoming larger than necessary. Thereafter, when the cutting of the wood W is completed, the opening / closing cover 18 is pulled by the tension spring 24 and rotated in the closing direction, as in the first embodiment. Thereby, the other end side of the rod-shaped member 32 enters the concave groove 33, and the cover operating mechanism 20 and the opening / closing cover 18 are returned to the state when the circular saw 30 is not used (the state shown in FIG. 7).

  As described above in detail, the circular saw 30 according to the second embodiment can achieve the same operational effects as the first embodiment described above (excluding the operational effects of the string-like member 23). In addition to this, in the second embodiment, the rod-shaped member 32 is used, and the opening / closing cover 18 is pressed and rotated by the movement of the movable member 31. The opening degree of 18 can be set with high accuracy.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the part which has the same function as 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted.

  FIG. 10 corresponds to FIG. 3 (wood introduction process) of the circle according to the third embodiment, and FIG. 11 corresponds to FIG. 4 (automatic opening process) of the circle according to the third embodiment. Each explanatory diagram is shown.

  As shown in FIGS. 10 and 11, the circular saw 40 according to the third embodiment is different from the first embodiment only in the shape of the movable member 21 constituting the cover operating mechanism 20. In the contact portion 21a of the movable member 41 in the third embodiment, a pair of opposing wall portions 41a (only one is shown in the drawing) are integrally provided so as to sandwich the saw blade 13 therebetween.

  The movable member 41 has a substantially U-shaped cross section made of a resin material such as transparent plastic so that the inside of each facing wall portion 41a can be looked into from the outside. Accordingly, the user can observe the cutting state by the saw blade 13 in the state shown in FIG. 11, that is, while the wood W is being cut by the circular saw 40, and further, the wood W accompanying the cutting work. It is possible to suppress the scattering of chips. Here, the movable member 41 is formed of a resin material such as transparent plastic, but the present invention is not limited to this, and can be formed of a less expensive opaque material if observation of the cut state is unnecessary.

  The operation of the cover operating mechanism 20 of the circular saw 40 is the same as the operation of the circular saw 10 according to the first embodiment. That is, as shown by the arrow M in FIG. 10, when the circular saw 40 is moved in the cutting direction, the end portion of the wood W comes into contact with the contact portion 21 a of the movable member 41. Then, the movable member 41 rotates around the rotation pin P in the direction of the arrow R10, and the contact portion 21a moves to one side (upper side in the figure) of the base 16 as shown in FIG. As a result, as shown by an arrow R11 in FIG. 11, the opening / closing cover 18 rotates in a direction to open from the broken line position toward the solid line position, and thus the opposing wall portions 41a cover the side surfaces on both sides of the saw blade 13 and the wood W Suppresses the scattering of chips.

  As described in detail above, the circular saw 40 according to the third embodiment can achieve the same operational effects as those of the first embodiment described above. In addition to this, in the third embodiment, the movable member 41 is provided with a pair of opposed wall portions 41a, and when the movable member 41 moves to one side of the base 16, the saw blade 13 is moved by each opposed wall portion 41a. Since the side surfaces of the wood W are covered, it is possible to prevent scattering of chips generated during the cutting operation of the wood W. Further, since the movable member 41 is formed of a resin material such as transparent plastic, the cutting position (cutting state) of the wood W by the saw blade 13 even if each opposing wall portion 41a of the movable member 41 covers the side surface of the saw blade 13. ) Can be easily confirmed.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 10 ... Circular saw (portable cutting machine), 11 ... Housing, 11a ... Motor accommodating part, 11b ... Handle part, 11c ... Saw cover, 12 ... Electric motor (electric motor), 12a ... Rotary shaft, 13 ... Saw blade,
DESCRIPTION OF SYMBOLS 14 ... Switch, 15 ... Light switch, 16 ... Base, 17 ... Inclination adjustment member, 18 ... Opening / closing cover, 18a ... Contact arc part, 20 ... Cover operation mechanism (opening / closing cover rotating means), 21 ... Movable member, 21a ... Contact part, 21b ... tension part, 22 ... hook part, 23 ... string-like member (cover operation member), 24 ... tension spring, 30 ... circular saw (portable cutting machine), 31 ... movable member, 31a ... first Corner part, 31b ... second corner part, 32 ... bar-shaped member (cover operation member), 33 ... concave groove, 40 ... circular saw (portable cutting machine), 41 ... movable member, 41a ... opposite wall part, C ... Rotation center, D ... Arrow display, P ... Rotating pin, W ... Wood (member to be processed)

Claims (6)

A housing; an electric motor housed in the housing; a saw blade that is rotationally driven by the electric motor to cut a workpiece; a base that is provided in the housing and that is in sliding contact with the workpiece; and is integrated with the housing A portable cutting device provided with a saw cover that covers one side from the base of the saw blade and an open / close cover that is rotatably provided on the housing and covers the other side of the base of the saw blade In the machine
A portable cutting machine having an opening / closing cover rotating means that is operated by contact with the workpiece on the introduction side of the workpiece relative to the saw blade of the housing and rotates the opening / closing cover. . The opening / closing cover rotating means includes:
Provided on the introduction side of the workpiece from the saw blade of the housing, protrudes to the other side of the base in a non-contact state of the workpiece, and moves to one side of the base by contact of the workpiece A movable member that
A cover operating member provided between the opening / closing cover and the movable member, and rotating the opening / closing cover in a direction to open by the movement of the movable member;
The portable cutting machine according to claim 1, comprising:   3. The portable cutting machine according to claim 2, wherein the cover operating member is a string-like member, and the string-like member is rotated in a direction of pulling and opening the opening / closing cover by the movement of the movable member.   3. The portable cutting machine according to claim 2, wherein the cover operating member is a rod-shaped member, and the rod-shaped member is rotated in a direction in which the opening / closing cover is pressed and opened by movement of the movable member.   The pair of opposing wall portions are provided on the movable member, and when the movable member moves to one side of the base, a side surface of the saw blade is covered with each of the opposing wall portions. The portable cutting machine according to any one of the above.   6. The portable cutting machine according to claim 5, wherein the movable member is made of a transparent material.

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