WO2020250716A1 - Outil électrique - Google Patents

Outil électrique Download PDF

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Publication number
WO2020250716A1
WO2020250716A1 PCT/JP2020/021329 JP2020021329W WO2020250716A1 WO 2020250716 A1 WO2020250716 A1 WO 2020250716A1 JP 2020021329 W JP2020021329 W JP 2020021329W WO 2020250716 A1 WO2020250716 A1 WO 2020250716A1
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WO
WIPO (PCT)
Prior art keywords
motor
grip portion
power tool
motor housing
tool according
Prior art date
Application number
PCT/JP2020/021329
Other languages
English (en)
Japanese (ja)
Inventor
谷本　英之
Original Assignee
工機ホールディングス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 工機ホールディングス株式会社 filed Critical 工機ホールディングス株式会社
Priority to JP2021525997A priority Critical patent/JPWO2020250716A1/ja
Publication of WO2020250716A1 publication Critical patent/WO2020250716A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
    • B24B23/02—Portable grinding machines, e.g. hand-guided; Accessories therefor with rotating grinding tools; Accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B41/00—Component parts such as frames, beds, carriages, headstocks
    • B24B41/04—Headstocks; Working-spindles; Features relating thereto
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
    • B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
    • B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
    • B25F5/02—Construction of casings, bodies or handles
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/14—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures
    • H02K21/16—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures having annular armature cores with salient poles

Definitions

  • the present invention relates to a power tool.
  • Patent Document 1 discloses a power tool in which a motor housing is provided behind a gear case that supports a spindle and an operation switch is arranged around a motor to be accommodated. In such a power tool, the operator grips the periphery of the motor so that the operation switch can be operated. In this way, the vicinity of the spindle is gripped, and pressing by the spindle (tip tool) becomes easy.
  • FIG. 11 is a top view showing a conventional disc grinder 101.
  • the disc grinder 101 has a motor housing 102 that houses a motor 110 that is a drive source. Behind the motor housing 102 is a diameter-expanded portion 102c that extends in the radial direction with respect to the axis C1, and the battery pack 80 is mounted. Further, the diameter-expanded portion 102c is provided with a control unit 150 for driving the motor 110.
  • a switch mechanism having a trigger lever 135 is provided between the motor 110 and the control unit 150. The switch mechanism switches ON or OFF of the motor 110, and includes a switch 132 and a swing-type trigger lever 135 for operating the switch 132.
  • the trigger lever 135 is provided with an off-lock lever 136.
  • a gear case 103 is provided in front of the motor housing 102.
  • the gear case 103 accommodates a drive transmission means that converts the power transmission direction of the rotation shaft of the motor 110 by about 90 degrees.
  • a spindle 116 is rotatably supported on the gear case 103, and the upper end of the spindle 116 and the rotating shaft of the motor 110 are connected by two bevel gears 106 and 107.
  • a grindstone 40 is fixed to the lower end of the spindle 116 by a mounting ring 146 and a mounting nut 147. The periphery of the rear side of the grindstone 40 is covered with a metal foil guard 145.
  • a cooling fan 125 is provided between the motor 110 and the gear case 103.
  • An outside air suction port (not shown) is provided on the side surface of the enlarged diameter portion 102c of the motor housing 102, and air is sucked into the motor housing 102 from the suction port by the rotation of the motor 110, and the air is sucked into the motor housing 102 from the rear side to the front of the motor housing 102. It flows to the side, passes around and inside the motor 110, flows from the vicinity of the fan 125 to the gear case 103 side, and is discharged to the atmosphere from the exhaust port provided in the gear case 103.
  • the motor 110 is installed inside the motor housing 102 forming the handle portion, it is difficult to further thin the grip portion of the motor housing 102 while maintaining the required output.
  • the fan 125 is located on the front side of the motor 110, it is structurally difficult to easily apply a downward load to the grindstone 40 by making the grip portion closer to the grindstone 40 side.
  • the reduction mechanism of the motor 110 is provided in the gear case 103, operating noise due to gear meshing is generated, and it is difficult to promote further noise reduction of the power tool.
  • the present invention has been made in view of the above background, and an object of the present invention is to shorten the distance between the portion gripped by the operator and the tip tool to achieve overall miniaturization and improve workability.
  • Another object of the present invention is to provide a power tool with reduced noise during operation by eliminating a transmission mechanism due to meshing of metal gears between a motor and a tip tool.
  • Still another object of the present invention is to provide a power tool with improved dust resistance by housing the motor in a metal sealed case.
  • a motor housing accommodating a motor having a stator and a rotor, a tip tool connected to an output shaft that rotates integrally with the rotor and rotating integrally with the output shaft, and a motor housing.
  • the thickness of the grip portion is configured to be smaller than the diameter of the portion of the motor housing that accommodates the motor.
  • the stator has a core formed by a laminated iron core, and the axial length of the core is made larger than the radius of the core.
  • the center position of the stator is set to be located closer to the tip tool than the longitudinal center axis of the grip portion.
  • a switch for turning on / off the motor is housed in the grip portion of the power tool.
  • the motor housing is made of metal, and the metal portion of the motor housing is exposed to the outside so that the heat of the motor is directly dissipated to the outside air.
  • a diameter-expanded portion is connected to the grip portion of the power tool on the opposite side of the connection portion with the motor housing, and a control board for controlling the motor intersects the axial direction of the grip portion at the diameter-expanded portion. Arranged so as to extend in the direction.
  • the enlarged diameter portion is provided with a battery attachment / detachment portion that allows the battery pack to be attached / detached.
  • the center of gravity of the entire tool overlaps the area of the grip.
  • the tip tool is disk-shaped, has a guard portion that covers at least a part of the tip tool, and overlaps the grip portion in the direction of the central axis of the grip portion. Further, a space in the output axis direction is formed between the guard portion and the grip portion so that the operator's finger can enter. Further, a screw hole for attaching a side handle is provided on the side surface of the motor housing. A plurality of screw holes for attaching the side handles may be provided side by side in the output shaft direction on the side surface of the motor housing.
  • the direct drive method is adopted for driving the tip tool, noise due to the reduction gear is not generated, and the problem of quietness can be solved.
  • the motor since the motor is not housed in the grip portion, the thickness of the grip portion can be made sufficiently thinner than before. Further, if the diameter of the stator core is increased, the position of the spindle moves forward from the grip portion, so that workability is likely to be impaired. However, in the configuration of the present invention, the torque of the motor can be improved without moving the position of the spindle forward. .. While using such a large motor and battery, the overall length is compact, the grip is easy to grip, and it is possible to realize a power tool with good maneuverability and workability.
  • FIG. 1 It is a vertical sectional view of the disc grinder 1 which concerns on embodiment of this invention. It is the same vertical cross-sectional view as FIG. It is a top view of the disc grinder 1 which concerns on embodiment of this invention. It is a front view of the disc grinder 1 which concerns on embodiment of this invention. It is sectional drawing of the part AA of FIG. It is sectional drawing of the BB part of FIG. It is a side view of the disc grinder 1 which concerns on embodiment of this invention. It is a figure for demonstrating an example of the accommodating method of the disc grinder 1 and the spare battery pack 80B which concerns on embodiment of this invention. It is sectional drawing of the disc grinder 1A which concerns on 2nd Example of this invention. It is a front view of the disc grinder 1A with the side handle 70 attached. It is sectional drawing of the CC part of FIG. It is a vertical sectional view of the disc grinder 101 which concerns on a prior art.
  • FIG. 1 is a vertical cross-sectional view of the disc grinder 1 according to the embodiment of the present invention.
  • the disc grinder 1 is a power tool that uses the power of the battery pack 80 to rotate a disk-shaped grindstone 40 by a motor 10.
  • the disc grinder 1 of this embodiment is characterized by the arrangement of the motor 10.
  • the motor 10 is arranged coaxially with the spindle 16 to which the grindstone 40 is fixed, and the spindle 16 is directly connected by the rotating shaft 15 of the motor 10.
  • a rotor having a cylindrical permanent magnet 12 is used on the outside of the rotor core 11, and a stator in which a coil 14 wound around the stator core 13 is arranged is provided on the outer peripheral side.
  • the motor 10 is an inner rotor type brushless DC motor.
  • the stator core 13 is composed of laminated iron cores and is housed inside a cylindrical motor housing 20.
  • a strong permanent magnet 12 is used in order to generate a large torque in the motor 10. Therefore, when iron powder enters the inside of the motor 10, the iron powder is attracted to the permanent magnet 12 and the efficiency of the motor is lowered. Therefore, in this embodiment, the motor housing 20 is made of metal and the motor housing 20 is cooled by the outside air as a closed type (fully closed type) motor 10 without using a cooling fan for cooling the motor 10. did.
  • the closed type means a structure in which air exchange with the outside is completely or almost never performed, and here, an opening on the side surface of the motor housing 20 is for passing the connecting protrusion 30a. There is only one through hole, and no cooling fan is provided inside the motor housing 20.
  • the main housing 2 is connected to the motor housing 20 from the rotation axis B1 of the motor 10 in the orthogonal direction to the rear side.
  • a grip portion 2b that is gripped by an operator with one hand is formed near the center of the main housing 2.
  • the grip portion 2b is provided with a paddle type switch mechanism 31.
  • the switch mechanism 31 includes a switch 32 and a paddle lever 35 that presses the plunger 33 (see FIG. 2 described later) of the switch 32.
  • the paddle lever 35 operates about a swing shaft 34 by a slight rotation angle, and is an operation unit for turning on or off the switch 32.
  • the state of FIG. 1 is a state in which the operator pulls the paddle lever 35 during work (a state in which the rotation of the motor 10 is on).
  • An enlarged diameter portion 2c having a rail mechanism 56 is formed on the rear side of the main housing 2, and the battery pack 80 is attached.
  • the enlarged diameter portion 2c of the main housing 2 is formed so as to expand in the radial direction as compared with the grip portion 2b, and a storage case 51 on which the control circuit board 52 is mounted is mounted inside the enlarged diameter portion 2c.
  • the storage case 51 has a tray shape with an opening surface facing forward, and the control circuit board 52 is housed inside the storage case 51.
  • the control circuit board 52 is mounted with a control circuit of the motor 10 such as an inverter circuit for driving the brushless DC motor 10.
  • the inverter circuit is composed of six FETs (Field Effect Transistors) that cannot be seen in the figure, and the FETs are provided with cooling fins 53 for heat dissipation.
  • the cooling fins 53 are made of an aluminum alloy having a predetermined wall thickness and a sufficient size, and the cooling fins 53 are arranged so that the surface direction thereof is along the central axis A1.
  • a rail mechanism 56 for connecting to the battery pack 80 is provided on the rear side of the storage case 51 and facing the battery pack 80, and a plurality of connection terminals 57 are provided inside the rail mechanism 56.
  • the rail mechanism 56 serves as the attachment / detachment portion of the battery pack 80, and its structure is composed of two parallel groove portions and a latch mechanism.
  • the structure of the battery pack attachment / detachment portion is arbitrary, and may have a shape that does not use a rail or a rail groove.
  • a connection terminal (not shown) on the battery pack 80 side is located at a position opposite to the connection terminal 57.
  • the battery pack 80 is widely used in power tools and the like, and contains a plurality of secondary battery cells inside a synthetic resin upper case 81 and a lower case 82. Here, lithium ions are used. A battery cell is used.
  • the upper case 81 is provided with a rail mechanism (not shown) and a connection terminal (not shown).
  • the battery pack 80 is attached to the main housing 2 by relatively moving from the bottom to the top. When removing the battery pack 80, the battery pack 80 is moved downward while pressing the latch button 83.
  • a battery pack support member 3 is formed at the center of the upper side of the battery pack 80 so as to project rearward.
  • the motor 10 is arranged so that the rotation axis 15 intersects the central axis A1 of the grip portion 2b of the main housing 2, where the rotation axis B1 of the motor is orthogonal to the central axis A1.
  • the end of the rotating shaft 15 of the motor 10 is fixed to the motor housing 20 by two ball bearings 18 and 19.
  • the motor housing 20 closes a cylindrical portion 21 having upper and lower opening surfaces along the rotation axis B1, a top cover 22 that closes the upper opening 21a of the cylindrical portion 21, and a lower opening 21b of the cylindrical portion 21. It is formed by the bottom cover 23. Both of these are formed of non-magnetic metals such as aluminum alloys.
  • the upper ball bearing 18 is held by the top cover 22, and the lower ball bearing 19 is held by the bottom cover 23. Since the ball bearings 18 and 19 are held by the metal motor housing 20 in this way, it is advantageous in terms of heat dissipation.
  • the coil 14 is wound around the stator core 13 in a predetermined winding manner, and a resin mold 17 is formed by applying resin to the portions protruding from the upper side and the lower side of the stator core 13 and curing the coil 14.
  • the resin mold 17 firmly holds the coil 14 so that it does not move due to vibration or the like, and also adheres to the inner wall surface of the cylindrical portion 21 on the outer peripheral side thereof to efficiently dissipate heat from the stator core 13 and the coil 14. It can be transmitted to the cylindrical portion 21.
  • the resin mold 17 By using the resin mold 17 in this way, the stator core 13 can be stably held by the cylindrical portion 21, and the heat dissipation of the motor 10 can be improved.
  • a disk-shaped sensor substrate 30 is arranged between the top cover 22 and the coil 14.
  • the sensor board 30 is for mounting three hole ICs 55 (only one can be seen in the figure), and is composed of an FPC board.
  • the hall IC 55 is a rotation position detecting element that detects the rotation position of the rotation shaft 15 (rotor 11).
  • the control unit 50 can control the rotation of the motor 10 based on the signal from the hall IC 55.
  • the sensor substrate 30 also serves to relay the wiring from the inverter circuit (not shown) to the coil 14.
  • the sensor substrate 30 is arranged so as to be orthogonal to the rotation axis B1, and the hall IC 55 faces the upper end surface of the permanent magnet 12.
  • the Hall IC 55 faces the upper end surface of the permanent magnet 12 to detect the change in magnetism of the permanent magnet 12 and detect the position of the rotating shaft 15.
  • a part of the sensor substrate 30 extends to the main housing 2 side so as to penetrate the through hole formed in the cylindrical portion 21, and the portion protruding outward from the cylindrical portion 21 is connected to the hole IC 55 and the coil 14. It becomes the connecting protrusion 30a which formed the pattern. That is, the connecting protrusion 30a is located outside the motor housing 20.
  • a power line 52a extends from the control unit 50 (control circuit board 52) and is connected to the connection protrusion 30a.
  • the power line 52a is a wiring for sending electric power from the inverter circuit mounted on the control circuit board 52 to the coil 14.
  • a signal line 52b extends from the control unit 50 (control circuit board 52) and is connected to the connection protrusion 30a.
  • the signal line 52b is a wiring for the control unit 50 to receive a signal transmitted by the hall IC 55. That is, the signal of the hall IC 55 is sent to the control unit 50 via the sensor substrate 30 (connecting protrusion 30a) and the signal line 52b.
  • the electric element (coil 14, hall IC55) housed in the motor housing 20 and the electric element (control unit 50, control circuit board 52) housed in the main housing 2 are located outside the motor housing 20. Is connected. Since a certain space is required for connecting the electric elements, in this embodiment, the connecting portion is located outside the motor housing 20, so that the motor housing 20 can be made smaller.
  • the bottom cover 23 also functions as a fixing member for the ball bearing 19 that pivotally supports the spindle 16.
  • a cylindrical portion 23a is formed on the bottom cover 23, and an outer peripheral surface of the spindle 16 is held by a sliding surface formed on the inner peripheral surface of the cylindrical portion 23a.
  • a wheel washer 41 is provided on the spindle 16, and the grindstone 40 is fixed to the spindle 16 so as to be sandwiched between the wheel washer 41 and the wheel nut 42.
  • the spindle 16 and the rotating shaft 15 are arranged side by side in the direction of the rotating axis B1, but they may be formed of an integral metal product as in this embodiment, or may be a separate product.
  • the grindstone 40 is, for example, a resinoid flexible toys, flexible toys, resinoid toys, sanding discs, etc. having a diameter of 100 mm, and can be used for surface polishing and curved surface polishing of metals, synthetic resins, marble, concrete, etc., depending on the type of abrasive grains used. is there.
  • the rear upper surface, rear side surface, and lower surface of the grindstone 40 are covered with a metal foil guard 45.
  • the foil guard 45 is for protecting the operator from scattering of ground members, damaged abrasive grains, and the like.
  • the grip portion 2b and the foil guard 45 partially overlap in the direction of the central axis A1 of the grip portion. And wherein the subtracting the paddle lever 35 during the work (swings upward), between the upper surface extending on the grip portion 2b of the wheel guard 45, since it is sufficient clearance H 2 as viewed in the rotational axis direction B1, A space 28 for the operator's fingers is secured, and the operator can perform the work while gripping the front side of the grip portion 2b. That is, since the operator can grip the portion of the spindle 16 closer to the rotation axis B1 than the conventional disc grinder 101 (see FIG. 11), the gripped portion of the operator is the pressing portion of the grindstone 40 during work (particularly the arrow at the tip).
  • the work can be performed with a light pressing force.
  • the paddle lever 35 since the paddle lever 35 also partially overlaps with the wheel guard 45 when viewed in the direction of the rotation axis B1, a paddle having a swing shaft 34 at the rear by a finger located near the motor housing 20. The front end of the lever 35 can be operated. As a result, the work can be performed with a light pressing force, and the paddle lever 35 can be operated reliably, so that the workability is further improved.
  • FIG. 2 is a vertical cross-sectional view similar to that of the disc grinder 1 of FIG. 1, and is a diagram showing a state in which the paddle lever 35 is not operated (switch-off state).
  • the left and right portions of the main housing 2 are fixed by four screws (not shown). Therefore, the main housing 2 on the right side is provided with screw bosses 9e to 9h.
  • the switch 32 has a plunger 33 extending in the vertical direction, and the plunger 33 is urged downward by a spring (not shown).
  • a pressing portion 35b is formed on the upper surface of the paddle lever 35, and the pressing portion 35b comes into contact with the lower end portion of the plunger 33.
  • the paddle lever 35 has a counterclockwise swing angle limited in the drawing by a stopper (not shown).
  • An off-lock lever 36 is provided near the front end of the paddle lever 35.
  • the lower end of the off-lock lever 36 is swung forward to move the upper end position of the paddle lever 35 to the rear.
  • the upper end of the off-lock lever 36 enters the hole portion 6c, so that the paddle lever 35 is rotated to the swing limit position. be able to.
  • the off-lock lever 36 is urged counterclockwise in the drawing by the torsion coil spring 37, when the operator releases the operation of the paddle lever 35, the upper end of the off-lock lever 36 is on the front side of the hole 6c. By moving to, the paddle lever 35 cannot be operated upward without operating the off-lock lever 36, and the locked state is maintained.
  • the grindstone 40 is driven by a direct drive method, and the grip portion 2b is installed between the motor 10 and the battery pack 80. Therefore, the thickness RH of the grip portion 2b becomes thin, and the total length of the product L (Fig. 1) can be made shorter than the total length L 0 of the conventional disc grinder 101 (see FIG. 11), and a compact disc grinder 1 can be realized. Specifically, the thickness (diameter) RH of the grip portion 2b could be made smaller than the diameter of the motor 10 (inner diameter of the motor accommodating portion of the motor housing 20). In this embodiment, the outer shape of the grip portion 2b is a perfect circle, but it may be oval or polygonal.
  • the thickness of the grip portion is the maximum size of the grip portion in the vertical and horizontal directions.
  • outer diameter D m the outer diameter of the stator core 13
  • the central axis A1 of the grip portion 2b connecting the motor 10 and the battery pack 80 is installed at a position sufficiently higher than the mounting surface PL, workability is improved. Specifically, the central axis A1 of the grip portion 2b is positioned above the vertical center position of the battery pack 80. If the center position of the grip portion 2b is lower than the center position of the battery pack 80, the arm of the operator who grips the grip portion 2b from above may interfere with the battery pack 80 or the battery pack support member 3 to hinder the work. However, the structure of this embodiment is configured so that such a trouble does not easily occur.
  • the grip portion 2b when the grip portion 2b is at a higher position, a large space below the grip portion 2b can be taken, so that it is possible to prevent the operator's fingers from coming into contact with the ground or the like when gripping the grip portion 2b. That is, the grip portion 2b can be easily gripped. Further, on the upper surface extension surface of the foil guard 45, the lower height (height from the PL surface to the lower 6b) of the grip portion 2b is higher than the lower end (end) height of the coil 14 from the PL surface.
  • the space inside the grip portion 2b where air convection is unlikely to occur is not located on the side of the lower coil end, and the circumference of the lower coil end can be easily cooled by the outside air, so that the motor cooling performance Is improved. This makes it possible to use a compact, lightweight, low-cost motor.
  • the grip portion 2b can be installed at a position close to the center of gravity of the heavy motor 10, the maneuverability during work is improved. Further, since the center of gravity is located between the grindstone 40 and the center of the grip portion 2b, the position control of the grindstone 40 becomes easy. Further, since the lower end of the battery pack 80 does not protrude below the PL surface, the grindstone 40 can be made difficult to come into contact with the mounting surface when the main body is mounted with the wheel guard 45 facing down. It is possible to prevent foreign matter from adhering to the surface and damage to the mounting surface by the grindstone 40.
  • FIG. 3 is a top view of the disc grinder 1 according to the embodiment of the present invention.
  • the main housing 2 is made of synthetic resin, the front side is connected to the motor housing 20, and the battery pack 80 is mounted on the rear side.
  • the main housing 2 is mainly composed of three parts, a motor fixing part 2a, a grip part 2b, and a diameter expanding part 2c, and these are manufactured by molding a synthetic resin divided into left and right parts.
  • the left side part and the right side part of the main housing 2 are separated by a vertical plane passing through the center line A1 (see FIG. 2), and are fixed by fixing means, for example, a plurality of screws or hooking means.
  • the motor fixing portion 2a is screwed to the motor housing 20 by a plurality of screws 5a, 5c and the like having axes in the horizontal direction.
  • a diameter-expanded portion 2c is formed on the side of the main housing 2 opposite to the connection point with the motor housing 20, and a speed adjustment dial 39 for adjusting the rotation speed of the motor 10 is formed on the upper side of the diameter-expanded portion 2c.
  • the operator grips the grip portion 2b with one hand (for example, the dominant hand). Therefore, the grip portion 2b is designed to have an optimum thickness so that it can be easily gripped.
  • the foil guard 45 is semi-circular when viewed from above, and its diameter is formed larger than that of the grindstone 40.
  • the motor housing 20 having a metal housing only a part of the rear side surface of the motor housing 20 is covered with a synthetic resin main housing 2 in consideration of heat dissipation, and the part other than the part where the main housing 2 is located is exposed to the outside air. It is put in the state of being. Further, a plurality of fins are formed in the motor housing 20 to improve heat dissipation.
  • the top cover 22 of the motor housing 20 is formed with a plurality of fins 22a extending in the front-rear direction.
  • FIG. 4 is a front view of the disc grinder 1 according to the embodiment of the present invention.
  • the state of FIG. 3 shows a state in which the removable side handle 70 is attached to the left side surface.
  • the operator grips the grip portion 2b (not visible in the figure) with his right hand and holds the side handle 70 with his left hand.
  • the side handle 70 the one used in the conventional example shown in FIG. 11 can be diverted.
  • a threaded portion 72 with a female screw is formed at the tip of a metal spindle portion (not visible in the figure), and the threaded portion 72 is a cylinder. It is screwed into any of the side handle mounting holes 25a to 25d (described later in FIG. 7) formed on the side surface of the portion 21.
  • a grip rubber 73 made of synthetic resin or rubber is attached around the spindle portion of the side handle 70. The grip rubber 73 is formed with a grip portion 74 to be gripped by an operator.
  • the motor housing 20 is formed by a cylindrical portion 21 that is cylindrical and has openings at the top and bottom, a top cover 22 that covers the upper opening 21a of the cylindrical portion 21, and a bottom cover 23 that covers the lower opening 21b.
  • the top cover 22 and the cylindrical portion 21 are fixed by four screws 26a to 26d (see also FIG. 3), and the bottom cover 23 and the cylindrical portion 21 are fixed by four screws 27a to 27d (see also FIG. 5 described later). Will be done.
  • a plurality of fins 21c extending in the vertical direction are formed on the front side surface and the rear side surface (see FIG. 6 described later) of the cylindrical portion 21.
  • a plurality of heat radiating fins 22a are formed on the top cover 22.
  • fins 23d are similarly formed on the front side surface, the rear side surface (not visible in the figure), and the entrance portion of the bottom surface of the bottom cover 23.
  • the fins 21c, 21d, 22a, and 23d are integrally formed during metal casting, and the fins 21c and 22a are arranged so as to be continuous, and the fins 21c and 23d are arranged so as to be continuous.
  • the wheel guard 45 that covers the grindstone 40 is a nut (visible in the figure) that connects the mounting ring 46 formed on the upper side of the wheel guard 45 and the bent portions that are the ends of the mounting ring 46. It is fixed to the cylindrical foil guard mounting portion 23b of the bottom cover 23 by (not).
  • FIG. 5 is a cross-sectional view of a portion AA of FIG.
  • the spindle 16, the cylindrical portion 23a, and the foil guard mounting portion 23b show a cross section
  • the other bottom cover 23 shows a bottom surface.
  • the bottom cover 23 is screwed to the cylindrical portion 21 (see FIG. 4) by four screws 27a to 27d oriented in the direction parallel to the rotation axis B1.
  • a large number of plate-shaped fins 23d extending from the front to the rear are formed.
  • the fins 23d are provided for heat dissipation for cooling the heat generated when the motor 10 rotates by the outside air.
  • the cylindrical portion 23a has a small gap with the spindle 16 so that dust does not enter the ball bearing 19.
  • the foil guard mounting portion 23b has a cylindrical shape, and a mounting ring 46 formed on the upper side of the wheel guard 45 is fixed to the outer peripheral surface thereof.
  • the space between the cylindrical portion 23a and the foil guard mounting portion 23b is hollow. The mounting ring 46 cannot be seen at the cross-sectional position of FIG.
  • FIG. 6 is a cross-sectional view of a portion BB of FIG.
  • the motor housing 20 is fixed so as to be in close contact with the contact surfaces 8a and 8b formed on the motor fixing portions 2a of the main housing 2 at the fixing portions 21e and 21f formed on the left and right side surfaces.
  • the stator core 13 is composed of a laminated iron core, has six teeth 13a from a cylindrical portion on the outer peripheral side toward the inside, a coil 14 is wound around each tooth 13a, and the periphery of the coil 14 is molded with resin 17. .. At the tip of the teeth 13a, an inner magnetic core portion 13b extending in the circumferential direction along the outer peripheral surface of the stator is formed.
  • a rotor having a permanent magnet 12 is attached to the rotating shaft 15.
  • the rotor is composed of a rotor core 11 and a cylindrical permanent magnet 12 provided on the outer peripheral surface of the rotor core 11.
  • the permanent magnet 12 is a magnet in which the magnetic flux is reversed in the radial direction, and is convenient because the magnetic flux does not flow to the rotating shaft 15 serving as the rotor shaft and the rotating shaft 15 is less likely to be magnetized.
  • a gap 4 is provided between the fin 21d on the rear side of the cylindrical portion 21 and the main housing 2 made of synthetic resin so as to be in a non-contact state.
  • the gap 4 communicates with the rotation axis B1 (see FIG. 1), and air can flow in the gap 4 in the vertical direction.
  • the motor fixing portion 2a is made of synthetic resin and has a smaller thermal conductivity than metal, it serves as a protective wall for heat transferred from the motor fixing portion 2a to the operator.
  • the left and right sides of the cylindrical portion 21 are formed to be thick in the radial direction, and key grooves continuous in the rotation axis B1 direction are formed. Further, keys 13c continuous in the rotation axis B1 direction are formed at two locations on the outer circumference of the stator core 13, and the key 13c is fitted into the key groove to hold the stator core 13 so as not to rotate in the circumferential direction.
  • FIG. 7 is a side view of the disc grinder 1 according to the embodiment of the present invention, showing a state in which the switch 32 is on. Since the motor housing 20 is a closed type, there is no exhaust port for exhausting air as seen in the gear case 103 of the conventional disc grinder 101 (see FIG. 11). Further, since the wheel nut 42 (see FIG. 1) is not provided with a spindle lock mechanism when the grindstone 40 is attached, a hexagon wrench is inserted into the hexagonal hole at the tip of the spindle 16 to prevent the spindle 16 from rotating. By fixing, the wheel nut 42 is tightened or loosened with another special tool.
  • the left and right parts of the main housing 2 are fixed by screws 5e to 5g. Further, the motor fixing portion 2a of the main housing 2 fixes the motor housing 20 with four screws 5a (see FIG. 3), 5b (not visible in the figure), 5c, and 5d. Two side handle mounting holes 25c and 25d are formed on the side surface of the cylindrical portion 21 of the motor housing 20 at a predetermined distance in the vertical direction. Although not visible in FIG. 7, side handle mounting holes 25a and 25b are similarly formed at the same positions on the right side surface of the cylindrical portion 21.
  • the motor fixing portion 2a of the main housing 2 mainly forms a portion for holding the two screws 5c and 5d, but here, a guard portion 2d extending further downward is formed.
  • the guard portion 2d is provided so that the operator's finger does not touch the rear surface (fin 21d shown in FIG. 6) of the motor housing 20 during work. Further, since a plurality of slits 2e (openings) are formed in the guard portion 2d, the flow of outside air flowing on the outer peripheral surface of the motor housing 20 near the coil end is also improved, so that the cooling efficiency of the motor 10 during work is improved.
  • Wind windows (not visible in the figure) for communicating the inside and the outside are formed on both side surfaces of the enlarged diameter portion 2c of the main housing 2.
  • the wind window is formed to cool the heat generating element of the internal control unit 50, and here, a removable mesh-structured filter 58 is installed so as to cover the outside of the wind window.
  • FIG. 8 is a diagram for explaining an example of a method of accommodating the disc grinder 1 and the spare battery pack 80B according to the embodiment of the present invention.
  • the packing material 90 is composed of a cushioning material 91 that fills the space between the corrugated cardboard box body and the disc grinder 1 inside the box body.
  • the cushioning material 91 was often composed of styrofoam, but in recent years, it is often composed of a combination of corrugated cardboard materials from the viewpoint of recycling. Further, it is widely practiced that the packing material 90 and the cushioning material 91 are formed of a special case made of synthetic resin.
  • the main battery pack 80A is packed in a state of being attached to the disc grinder 1.
  • a second battery pack 80B is housed inside the packing material 90 as a spare.
  • the mounting position of the wheel guard 45 is rotated by about 180 degrees from the state shown in FIG. 1 and arranged so as to project forward. Then, a sufficient space for accommodating the battery pack 80 can be secured in the portion below the grip portion 2b and between the motor housing 20 and the enlarged diameter portion 2c when viewed in the front-rear direction.
  • the spare battery pack 80B can be easily stored in the small packing material 90. It has the characteristic of becoming.
  • the disc grinder 1 and the spare battery pack 80B can be accommodated in the packing material 90 smaller than the conventional one.
  • the width of the battery pack shown in FIG. 8 is the size (length) of the battery pack 80 in the left-right direction of FIG.
  • FIG. 9 is a cross-sectional view of the disc grinder 1A according to the second embodiment of the present invention.
  • the portion different from the first embodiment shown in FIGS. 1 to 7 is the shape of the main housing 7.
  • the main housing 7 is formed by a motor fixing portion 7a, a grip portion 2b, a diameter expanding portion 2c, and a reinforcing rib 7b formed at a connecting portion between the motor fixing portion 7a and the grip portion 2b. That is, the shape is such that a reinforcing rib 7b is newly added to the main housing 2 shown in FIG.
  • the thickness of the grip portion 2b can be made thinner than that of the conventional disc grinder 101 (see FIG. 10).
  • a plate-shaped reinforcing rib 7b extending in the vertical direction is provided between the motor housing 20 and the grip portion 2b.
  • the reinforcing rib 7b is integrally formed with the main housing 7 by molding a synthetic resin.
  • Reinforcing ribs 7b are formed on the right side part and the left side part of the motor housing 20, respectively, and the right side and left side reinforcing ribs 7b are joined to each other. Further, the lower end portion of the reinforcing rib 7b extends downward so as to be aligned with the bottom surface position of the bottom cover 23.
  • the front side of the paddle lever 38 was cut down to shorten it in accordance with the formation of the reinforcing rib 7b.
  • the front end of the paddle lever 38 is configured to be close to the rear end of the reinforcing rib 7b so that the operator does not pinch his finger in the gap between the reinforcing rib 7b and the paddle lever 38.
  • the position of the off-lock lever 36 and the configuration (switch 32, swing shaft 34, etc.) on the side where the paddle lever 38 is attached are the same as those in the first embodiment.
  • FIG. 10 is a cross-sectional view of a portion CC of FIG. From this cross-sectional view, it can be understood that the reinforcing ribs 7b are formed on the right side part and the left side part of the main housing 7, respectively.
  • the portion indicated by the dotted line 29 is divided into two left and right by the reinforcing rib 7b.
  • the reinforcing rib 7b is located between the index finger and the thumb, so that the positional relationship is such that the index finger and the thumb sandwich the grip portion 2b in the left-right direction. It has virtually no effect on operation.
  • the left and right reinforcing ribs 7b do not have to be joined, but may be fixed by a hooking claw (not shown), an adhesive or the like so as not to be separated.
  • the present invention has been described above based on the examples, the present invention is not limited to the above-mentioned examples, and various modifications can be made without departing from the spirit of the present invention.
  • the disc grinder has been described as an example of a power tool, but it can be similarly applied not only to a disc grinder but also to a polisher or a cutting machine using a disk-shaped tip tool.
  • control unit A1, C1 ... (grip unit) central axis , B1, D1 ... (motor) rotation axis, an outer diameter of D m ... motor, L 0 ... product overall length, L C ... stator core lamination thickness, PL ... placement surface

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)

Abstract

L'invention concerne un outil électrique qui présente une courte distance entre un outil à pointe et une section saisie par un travailleur et qui améliore la maniabilité. L'outil électrique (1) comprend : un carter de moteur (20) qui loge un moteur muni d'un stator et d'un rotor ; un outil à pointe (40) relié à un arbre de sortie (16) qui tourne d'un seul tenant avec le rotor ; et une poignée (2b) qui s'étend à partir du carter de moteur (20) dans une direction qui coupe l'arbre de sortie. L'épaisseur (diamètre RH) de la poignée (2b) est conçue de manière à être inférieure au diamètre Dm d'une section logeant le moteur dans le carter de moteur (20) et la longueur de direction axiale LC du noyau de stator est conçue pour être plus grande que le rayon (= diamètre Dm/2).
PCT/JP2020/021329 2019-06-14 2020-05-29 Outil électrique WO2020250716A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114905356A (zh) * 2022-05-17 2022-08-16 中建八局第一建设有限公司 一种施工墙体打磨装置

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6078253U (ja) * 1983-11-02 1985-05-31 神鋼電機株式会社 グラインダ
JPS6311272A (ja) * 1986-07-02 1988-01-18 Shinko Electric Co Ltd 電動デイスクグラインダ
JPH04223861A (ja) * 1990-12-20 1992-08-13 Makita Corp 携帯用回転工具
US5642008A (en) * 1995-10-20 1997-06-24 Waxing Corporation Of America, Inc. Power tool motor assembly
US20090221222A1 (en) * 2008-02-28 2009-09-03 Techway Industrial Co., Ltd. Electric grinding gun
US20110081846A1 (en) * 2009-10-05 2011-04-07 Tai-Her Yang Internal rotation type direct motor-drive portable angle grinder
JP2012016776A (ja) * 2010-07-07 2012-01-26 Makita Corp オービタルサンダ
JP2013119129A (ja) * 2011-12-06 2013-06-17 Makita Corp 電動工具
US20140370791A1 (en) * 2013-06-12 2014-12-18 Robert Bosch Gmbh Hand-Held Power Tool with an Electromotive Drive and at least a First Housing Part
JP2016087740A (ja) * 2014-11-05 2016-05-23 株式会社マキタ 電動工具
US20160199958A1 (en) * 2013-08-09 2016-07-14 Robert Bosch Gmbh Portable Power Tool having an Electromotive Direct Drive
JP2017525581A (ja) * 2014-06-17 2017-09-07 ローベルト ボッシュ ゲゼルシャフト ミット ベシュレンクテル ハフツング ダイレクトドライブとしての電子的に整流された電動機を有する手持ち式工作機械

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5826526B2 (ja) * 2011-06-08 2015-12-02 株式会社マキタ 電動工具

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6078253U (ja) * 1983-11-02 1985-05-31 神鋼電機株式会社 グラインダ
JPS6311272A (ja) * 1986-07-02 1988-01-18 Shinko Electric Co Ltd 電動デイスクグラインダ
JPH04223861A (ja) * 1990-12-20 1992-08-13 Makita Corp 携帯用回転工具
US5642008A (en) * 1995-10-20 1997-06-24 Waxing Corporation Of America, Inc. Power tool motor assembly
US20090221222A1 (en) * 2008-02-28 2009-09-03 Techway Industrial Co., Ltd. Electric grinding gun
US20110081846A1 (en) * 2009-10-05 2011-04-07 Tai-Her Yang Internal rotation type direct motor-drive portable angle grinder
JP2012016776A (ja) * 2010-07-07 2012-01-26 Makita Corp オービタルサンダ
JP2013119129A (ja) * 2011-12-06 2013-06-17 Makita Corp 電動工具
US20140370791A1 (en) * 2013-06-12 2014-12-18 Robert Bosch Gmbh Hand-Held Power Tool with an Electromotive Drive and at least a First Housing Part
US20160199958A1 (en) * 2013-08-09 2016-07-14 Robert Bosch Gmbh Portable Power Tool having an Electromotive Direct Drive
JP2017525581A (ja) * 2014-06-17 2017-09-07 ローベルト ボッシュ ゲゼルシャフト ミット ベシュレンクテル ハフツング ダイレクトドライブとしての電子的に整流された電動機を有する手持ち式工作機械
JP2016087740A (ja) * 2014-11-05 2016-05-23 株式会社マキタ 電動工具

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114905356A (zh) * 2022-05-17 2022-08-16 中建八局第一建设有限公司 一种施工墙体打磨装置
CN114905356B (zh) * 2022-05-17 2024-02-13 中建八局第一建设有限公司 一种施工墙体打磨装置

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