JP2015112652A - Portable circular saw and portable cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable circular saw which has a compact structure and good operability even if there is a control circuit substrate of a brushless motor.SOLUTION: A portable circular saw 1 has a brushless motor 5 equipped with a stator 26, and a rotor 27 rotating to the stator 26; a first gear 37 provided on the rotor 27; a second gear 45 engaged with the first gear 37; an output shaft 48 rotating with the rotations of the second gear 45; a saw blade 4 fixed to the output shaft 48; and a base 2 rotatable to the brushless motor 5. A control circuit substrate 58 for driving the brushless motor 5 is disposed under the brushless motor 5, and the second gear 45 is disposed between the saw blade 4 and the control circuit substrate 58.

Description

  The present invention relates to a portable marnoco and a portable cutting machine.

  A portable marnoco is known that uses a small and durable brushless motor as a drive source (see Non-Patent Document 1), and a control circuit board on which an IGBT module, a microcomputer, a capacitor, and the like are mounted is a brushless motor. It is arranged on the side of.

Makita General Catalog 2013-4, [Search on November 6, 2013], Internet <http://www.makita.co.jp/product/ecatalog/sougou/index.html#56>

  However, in this portable marnoco, the width dimension is increased by the control circuit board, which hinders downsizing. Further, depending on the position of the control circuit board, the space on the upper side of the motor housing where the grip is provided may be reduced and the operability may be deteriorated.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a portable marnoco and a portable cutting machine that have a compact configuration and good operability even with a brushless motor control circuit board.

In order to achieve the above object, a first aspect of the present invention provides a brushless motor including a stator, a rotor rotating with respect to the stator, a first gear provided in the rotor, and a first gear meshing with the first gear. A portable circuit board having two gears, an output shaft that rotates in accordance with the rotation of the second gear, and a saw blade fixed to the output shaft, and a control circuit board for driving the brushless motor is brushless. It is arrange | positioned under the motor and the 2nd gear is arrange | positioned between a saw blade and a control circuit board, It is characterized by the above-mentioned.
To achieve the above object, a second aspect of the present invention provides a brushless motor including a stator, a rotor that rotates with respect to the stator, a first gear and a fan provided in the rotor, and a first gear. A portable marnoco having an output shaft that rotates with rotation and a saw blade fixed to the output shaft, and a control circuit board for driving the brushless motor is disposed below the brushless motor and the fan. It is characterized by that.
According to a third aspect of the present invention, in the configuration of the second aspect, the control circuit board is cooled by an air flow generated as the fan rotates.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the control circuit board is housed in a metal case.
In order to achieve the above object, a fifth aspect of the present invention provides a brushless motor including a stator and a rotor that rotates with respect to the stator, an output shaft that rotates as the brushless motor is driven, and an output shaft. A control circuit board for driving the brushless motor is disposed in front of the brushless motor.
According to a sixth aspect of the present invention, in the configuration of the fifth aspect, the control circuit board is accommodated in a metal case.

  According to the present invention, even if there is a control circuit board, the width dimension does not increase, and compactness can be maintained. Further, since the control circuit board does not protrude in the space above the motor housing where the grip portion is provided, the operability is improved.

It is a side view of a portable marnoco. It is a top view of a portable marnoco. It is the sectional view on the AA line of FIG. FIG. 3 is a sectional view taken along line B-B in FIG. 2. It is a top view of the portable marunoco of the example of a change. It is CC sectional view taken on the line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a side view showing an example of a portable marnoco (hereinafter simply referred to as “marunoko”), FIG. 2 is a plan view thereof, FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, and FIG. FIG. The marunoco 1 is provided with a main body 3 provided with a disk-like saw blade 4 that is rotationally driven by a brushless motor 5 above a base 2 that is rectangular in plan view. The main body 3 includes a motor housing 6 in which the brushless motor 5 is accommodated, a gear housing 7 connected to the right side of the motor housing 6 (the right side in FIG. 1 is the front (cutting direction)), and the right side of the gear housing 7. A blade case 8 that is connected to cover the upper portion of the saw blade 4 is formed. Above the gear housing 7, a loop-shaped grip housing 9 is provided.

  The front side of the blade case 8 is pivotally attached to a U-shaped connecting plate 10 in a plan view so as to be rotatable in the vertical direction by screws 11. The connecting plate 10 is erected on the base 2 and has an arc shape. A guide plate 12 having a guide groove is connected to a left and right guide plate 12 so as to be rotatable by a front and rear pin and fixed at an arbitrary position along the guide groove by a knob screw 13. On the other hand, on the rear side of the blade case 8, a left-right guide plate 14 having an arcuate guide groove is erected on the base 2, and the guide plate 14 faces the front side of the blade case 8. A depth guide 15 that is curved in a circular arc shape is connected so that it can be rotated by a pin in the front-rear direction and fixed at an arbitrary position along the guide groove by a knob screw 16 (however, one of the knob screws 13 and 16 is a rotating shaft). Only good.) A screw shaft 17 provided on the side surface of the blade case 8 passes through the depth guide 15 and can be arbitrarily clamped by operating a lever 18 provided at an end of the screw shaft 17.

  Therefore, the main body 3 is rotated about the screw 11 by changing the clamping position of the blade case 8 along the depth guide 15 (however, it may be clamped to the motor housing 6), so that the base 2 The protrusion amount (cut amount) of the saw blade 4 protruding downward through the provided square hole 19 can be adjusted. Further, by changing the fixing position of the connecting plate 10 and the depth guide 15 in the front and rear guide plates 12 and 14, the main body 3 is tilted to the right from the right angle position where the saw blade 4 is orthogonal to the base 2 and sawed. The blade 4 can be fixed at any inclination angle up to the maximum inclination position where the blade 4 is inclined at an angle of 45 ° (45 ° or more (for example, 56 °)). However, it does not matter even if it does not have this inclined cutting function. The front end of the base 2 is formed with cuts 20 and 20 whose side edges are positioned on the extension of the saw blade 4 at the right angle (0 °) position and 45 ° position of the saw blade 4, respectively. By aligning the side edge of the notch 20 with the black line indicated on the upper surface of the line, cutting along the black line can be easily performed.

  On the other hand, the grip housing 9 includes a left half housing 9a and a right half housing 9b, which are connected to the motor housing 6 (or may be structured to be screwed separately), and screws 21, 21,. The rear part is a grip part 22. A switch 23 in which a trigger 24 protrudes downward is accommodated on the front side of the grip part 22, and a power cord 25 is connected to the rear side of the grip part 22.

  The brushless motor 5 is an inner rotor type having a stator 26 and a rotor 27. First, the stator 26 includes a stator core 28 made of a plurality of laminated steel plates and a pre-insulating member 29 provided before and after the stator core 28. And the rear insulating member 30 (in the description of the inside of the main body 3 shown in FIG. 3, the saw blade 4 side is the front and the brushless motor 5 side is the rear for convenience), the front insulating member 29 and the rear insulating member 30. And six coils (not shown) wound around the stator core 28. In addition, the rotor 27 is disposed on the outer side of the rotating shaft 31 positioned at the shaft center, the cylindrical rotor core 32 disposed around the rotating shaft 31, and the outer surface of the rotor core 32. Permanent magnets 33 whose polarities are alternately changed, and a plurality of sensor permanent magnets (not shown) arranged radially on the rear side thereof. A sensor circuit board 34 mounted with three rotation detection elements that detect the position of the sensor permanent magnet of the rotor 27 and output a rotation detection signal is fixed to the rear end (or the front end) of the rear insulating member 30. Yes.

The rotary shaft 31 is rotatably supported by a bearing 35 held at the rear portion of the motor housing 6 and a bearing 36 held by the gear housing 7, and a front end forming the first gear 37 is formed in the gear housing 7. It is protruding. A centrifugal fan 38 for cooling the motor is fixed behind the bearing 36 in the rotary shaft 31, and a plurality of air inlets 39, 39... Are formed on the rear surface of the motor housing 6. A dish-shaped baffle plate 40 is provided so as to penetrate the rotary shaft 31 and surround the centrifugal fan 38.
Further, an intermediate shaft 41 parallel to the rotation shaft 31 is held in front of the rotation shaft 31 by a bearing 42 whose rear end is held by the gear housing 7, and its front end is held by a bearing retainer 43 assembled to the blade case 8. The large-diameter second gear 45 provided at the rear portion of the intermediate shaft 41 is engaged with the first gear 37 of the rotating shaft 31. 46 is a ring which is held by the bearing retainer 43 in front of the bearing 44 and receives the thrust load of the bearing 44. A third gear 47 having a smaller diameter than the second gear 45 is formed at the front portion of the intermediate shaft 41.

  Further, in front of the intermediate shaft 41, an output shaft 48 parallel to the intermediate shaft 41 is supported by a bearing 49 whose rear end is held by the blade case 8 and a bearing 50 whose front end is held by the bearing retainer 43. Thus, the front end penetrating the bearing retainer 43 protrudes into the blade case 8. A fourth gear 51 that meshes with the third gear 47 of the intermediate shaft 41 is provided at the rear portion of the output shaft 48. The saw blade 4 is sandwiched between the outer flange 52 and the inner flange 53 at the front end of the output shaft 48 and is fixed by a bolt 54 that is screwed into the shaft center of the output shaft 48 from the front. A safety cover 55 is rotatably mounted on the bearing retainer 43 in the blade case 8 and is normally urged to rotate so as to cover the lower side of the saw blade 4 as shown in FIG. A shaft lock 64 prevents the rotation shaft 31 from rotating by being pushed into the main body 3 when the saw blade 4 is attached or detached.

On the other hand, as shown in FIGS. 3 and 4, a projecting housing 56 is provided below the motor housing 6 in parallel with the base 2, and a controller 57 is accommodated in the projecting housing 56. The controller 57 includes a case (for example, made of aluminum) having a control circuit board 58 on which a rectifier circuit and an inverter circuit are formed by mounting a diode, a smoothing capacitor, an IGBT (Insulated Gate Bipolar Transistor) module and the like in addition to a microcomputer. ) 59.
Further, the inside of the overhanging housing 56 communicates with the motor housing 6, and an intake port 60 is also formed on the left end surface of the overhanging housing 56.

  Further, the controller 57 is formed in a length that is substantially the same position as the front end of the motor housing 6 in the cutting direction, and a position that greatly exceeds the rear end of the motor housing 6 on the opposite side to the cutting direction. The left end is below the bearing 35 that supports the rotating shaft 31 of the brushless motor 5, and the right end is formed at a length below the front end of the centrifugal fan 38. With this arrangement, the second gear 45 is positioned between the saw blade 4 and the control circuit board 58.

  In the Marunoco 1 configured as described above, when the trigger 24 is pulled upward, the switch 23 is turned on to supply commercial power, and the brushless motor 5 is driven by the DC power rectified by the controller 57. That is, the microcomputer of the controller 57 obtains the rotation detection signal indicating the position of the sensor permanent magnet of the rotor 27 output from the rotation detection element of the sensor circuit board 34, acquires the rotation state of the rotor 27, and acquires the rotation state. In response to this, ON / OFF of the IGBT module is controlled, and the rotor 27 is rotated by causing a current to flow sequentially to each coil of the stator 26. Therefore, the rotary shaft 31 rotates, the intermediate shaft 41 rotates from the first gear 37 through the second gear 45, and the output shaft 48 rotates from the third gear 47 through the fourth gear 51. 4 rotates and it becomes possible to cut | disconnect a to-be-cut material.

  The cooling air sucked into the motor housing 6 from the air inlet 39 by the rotation of the centrifugal fan 38 accompanying the rotation of the rotating shaft 31 passes through the brushless motor 5 to cool the brushless motor 5, and then the baffle plate 40. Is sent to the gear housing 7 side. The cooling air sucked from the intake port 60 of the overhanging housing 56 passes through the controller 57 and cools the control circuit board 58, then moves into the motor housing 6 and is similarly moved by the baffle plate 40 to the gear housing 7. Sent to the side. Since the control circuit board 58 is accommodated in the case 59, the heat generated in the control circuit board 58 is radiated through the case 59 and is effectively cooled by the cooling air. Most of the cooling air sent to the gear housing 7 side is blown into the blade case 8 and merged with the air flow generated by the rotation of the saw blade 4 to form the exhaust formed on the right side surface of the blade case 8. It is discharged from the mouth 62 (FIG. 1). However, the intake port and the exhaust port may be reversed. The remaining part of the cooling air is sent to the front end of the blade case 8 through the duct 63 provided on the left side surface of the blade case 8 and blown to the front end of the base 2. Therefore, it is prevented that the black line is hidden by the chips.

  Thus, according to the Marunoco 1 of the said form, even if there is the control circuit board | substrate 58, a width dimension does not become large and compactization can be maintained. Further, since the control circuit board 58 does not protrude in the space above the motor housing 6 where the grip portion 22 is provided, the operability is improved.

The arrangement of the control circuit board is not limited to the lower side of the brushless motor, and a box-shaped overhanging housing 56 protruding forward in the cutting direction is provided on the motor housing 6 as shown in the marnoco 1A shown in FIGS. Alternatively, the controller 57 may be accommodated vertically in the projecting housing 56 through a continuous communication portion 65. Also in this case, the controller 57 can be arranged using the space in front of the brushless motor 5.
In addition, the controller is not limited to the lower side or only the front side of the brushless motor, but the controller is arranged in an inclined manner from the lower side to the front side of the brushless motor, or one of the two divided control circuit boards is connected to the brushless motor. It is also possible to arrange the other on the front side of the brushless motor below (in this case, two substrates are arranged at an angle, and signal transmission and power supply are performed by lead wires or the like).

Further, in the above embodiment, the intermediate shaft is interposed between the rotating shaft and the output shaft. However, there may be two or more intermediate shafts, and conversely, the intermediate shaft is omitted and the first shaft of the rotating shaft is omitted. The gear may be meshed with a second gear provided on the output shaft.
In addition, as the brushless motor, an S-R motor, a high-frequency motor, or the like can be employed. Further, the number of poles of the rotor can be appropriately changed to 6 or less. Note that the number of coils that must be driven by the controller can be reduced by setting the number to 6 or less. For this reason, a brushless motor can be controlled more easily.
The present invention is not limited to a portable power saw driven by a commercial power supply, but also a portable power tool powered by a battery, a portable cutting machine such as a cutter, and a jigsaw having a cutting blade reciprocated by a reciprocating mechanism. The invention is applicable.

  1, 1A ··· Portable Marnoko · 2 · · Base 3 · · Body 4 · · Saw blade 5 · · Brushless motor 6 · · Motor housing 7 · · Gear housing 8 · · Blade case 26 .., stator, 27..rotor, 31..rotary shaft, 37..first gear, 41..intermediate shaft, 45..second gear, 47..third gear, 48..output shaft, 51 .. · Fourth gear, 56 · · Overhang housing, 57 · · Controller, 58 · · Control circuit board, 59 · · Case.

Claims (6)

A brushless motor comprising a stator and a rotor that rotates relative to the stator;
A first gear provided on the rotor;
A second gear meshing with the first gear;
An output shaft that rotates as the second gear rotates;
A portable saw having a saw blade fixed to the output shaft,
A control circuit board for driving the brushless motor is disposed below the brushless motor;
The portable marnoco, wherein the second gear is disposed between the saw blade and the control circuit board. A brushless motor comprising a stator and a rotor that rotates relative to the stator;
A first gear and a fan provided in the rotor;
An output shaft that rotates as the first gear rotates;
A portable saw having a saw blade fixed to the output shaft,
A portable marnoco, wherein a control circuit board for driving the brushless motor is disposed below the brushless motor and the fan.   The portable control board according to claim 2, wherein the control circuit board is cooled by an air flow generated as the fan rotates.   The portable control board according to any one of claims 1 to 3, wherein the control circuit board is accommodated in a metal case. A brushless motor comprising a stator and a rotor that rotates relative to the stator;
An output shaft that rotates as the brushless motor is driven;
A portable cutting machine having a saw blade fixed to the output shaft,
A portable cutting machine, wherein a control circuit board for driving the brushless motor is disposed in front of the brushless motor.   The portable cutting machine according to claim 5, wherein the control circuit board is accommodated in a metal case.

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