Electric working machine

Patent metadata

Field	Value
Publication number	US-12589478-B2
Application number	US-202418585630-A
Country	US
Kind code	B2
Filing date	Feb 23, 2024
Priority date	Mar 10, 2023
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

A hand-held electric working machine for cutting a work object is provided. The electric working machine comprises a working portion, a motor, a control unit, and a guide portion. The working portion is configured to cut the work object. The motor is configured to allow rotary power to be generated for allowing the working portion to drive. The control unit is configured to electrically control rotation of the motor. The guide portion is provided on the control unit, thereby forming a first air flow path surrounded by the guide portion and the control unit. The first air flow path is configured to allow air to circulate therein by rotation of the motor, thereby cooling the control unit.

First claim

What is claimed is:

1 . A hand-held electric working machine for cutting a work object, comprising:
a working portion configured to cut the work object; a motor configured generate rotary power to drive the working portion; a control unit configured to electrically control rotation of the motor; a guide portion provided on the control unit, thereby forming a first air flow path surrounded by the guide portion and the control unit, wherein the first air flow path is configured to circulate air therein by rotation of the motor, thereby cooling the control unit; and a housing:
extending in a first direction from a rear side where a user is positioned to a front side where the work object is positioned; and
having an inlet and an outlet that are configured to circulate air inside the housing, wherein
the inlet is provided on a first side of the housing positioned in a second direction with respect to a centerline of the housing, the centerline extends along the first direction, and the second direction is perpendicular to the first direction, and the outlet is provided on a second side of the housing facing the inlet across the centerline.

2 . The electric working machine according to claim 1 , wherein
the first air flow path connects to a second air flow path provided in a vicinity of the motor, and the second air flow path is configured to circulate air therein by rotation of the motor, thereby cooling the motor following the control unit.

3 . The electric working machine according to claim 1 , wherein
the first air flow path includes a heat sink configured to exchange heat with the air circulating therein, and the heat sink is provided in contact with the control unit so as to dissipate the heat generated by the control unit.

4 . The electric working machine according to claim 3 , wherein
the heat sink has a fin extending toward a vertical direction from a surface that is in contact with the control unit, and the fin further extends in a direction along air flow circulating in the first air flow path.

5 . The electric working machine according to claim 1 , further comprising:
a second air flow path provided in a vicinity of the motor, wherein the first air flow path is configured in such a manner that one end of the first air flow path is connected to the second air flow path and the other end of the first air flow path is connected to the inlet.

6 . The electric working machine according to claim 1 , further comprising:
a second air flow path provided in a vicinity of the motor, wherein the second air flow path is configured in such a manner that one end of the second air flow path is connected to the first air flow path and the other end of the second air flow path is connected to the outlet.

7 . The electric working machine according to claim 1 , further comprising:
a second air flow path provided in a vicinity of the motor, wherein the motor:
includes a fan rotating with the rotation of the motor; and
is configured to be rotatable in two rotational directions as a right rotation direction and a left rotation direction,
the fan:
has two or more linear-shaped vanes so as to extend straight from a center of an axis around which the motor rotates toward an outside in a circumferential direction; and
is provided inside the second air flow path to circulate air inside the second air flow path,
the second air flow path is configured with a third air flow path and a fourth air flow path so as to branch air circulation in a vicinity of the fan, and the third air flow path and the fourth air flow path are configured in such a manner that an amount of the air circulation varies according to a rotational direction of the two rotational directions of the motor, respectively.

8 . The electric working machine according to claim 7 , wherein
the third air flow path is provided with a portion along approximately first half circumference of an outer periphery of the fan, and the fourth air flow path is provided with a portion along approximately second half circumference of the outer periphery of the fan and the fourth air flow path faces the third air flow path across the axis.

9 . The electric working machine according to claim 8 , wherein
each of the third air flow path and the fourth air flow path is configured in such a manner that a cross-sectional area of a corresponding air flow path of the third and fourth air flow paths expands from upstream to downstream in an air flow direction.

10 . The electric working machine according to claim 7 , wherein
the outlet is configured with a first outlet and a second outlet positioned differently from the first outlet, and the first outlet is connected to the third air flow path, and the second outlet is connected to the fourth air flow path.

11 . The electric working machine according to claim 1 , wherein
the housing has a first width and a second width that is narrower than the first width, and the first and second widths are located along a direction from the centerline of the housing where toward the inlet, and the inlet is provided on the first side of the housing where the second width is positioned.

12 . The electric working machine according to claim 1 , wherein
the inlet has a louver to prevent an object from entering the housing from an upper direction.

13 . The electric working machine according to claim 1 , wherein
the electric working machine is a hedge trimmer, a brush cutter, or a chainsaw.

Assignees

• Yamabiko Corp

Inventors

• Kodama Hisao
• Osawa Hisato
• Maeno Takeshi
• Morisaki Yusuke

Classifications

• H02K9/06

  with fans or impellers driven by the machine shaft · CPC title

• H02K7/145

  Hand-held machine tool · CPC title

• A01G3/086

  Chain saws · CPC title

• H02K5/207

  with openings in the casing specially adapted for ambient air · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title