Power equipment

Patent metadata

Field	Value
Publication number	US-11026366-B2
Application number	US-201716342483-A
Country	US
Kind code	B2
Filing date	Nov 16, 2017
Priority date	Nov 25, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

Walk-behind power equipment includes: a main body provided with at least one front wheel and left and right rear wheels and a work unit; travel motors provided for the respective rear wheels; a handle extending from the main body rearward and upward; at least one of a tilt angle detector that detects a tilt angle of the main body and a load detector that detects a downward load applied to the handle; a yaw rate detector that detects a yaw rate; and a control unit that drive-controls the travel motors. The control unit determines whether the main body is in a rearward tilted state based on the tilt angle or the downward load, and if it is determined that the main body is not in the rearward tilted state, performs straight-line travel control to set a rotational speed difference between the travel motors to reduce the yaw rate.

First claim

The invention claimed is:

1. Walk-behind power equipment, comprising:
a main body provided with at least one front wheel and a pair of left and right rear wheels;
a work unit provided on the main body;
a pair of left and right travel motors provided for the respective rear wheels;
a handle connected to the main body and extending rearward and upward;
a tilt angle detector that detects a tilt angle of the main body;
a yaw rate detector that detects a yaw rate generated on the main body; and
a control unit that drive-controls the travel motors,
wherein the control unit determines whether the main body is in a rearward tilted state based on the tilt angle, and if it is determined that the main body is not in the rearward tilted state, the control unit performs straight-line travel control to set a rotational speed difference between the left and right travel motors to reduce the yaw rate, and if it is determined that the main body is in the rearward tilted state, the control unit does not perform the straight-line travel control.

2. The power equipment according to claim 1 , further comprising a lateral load detector that detects a leftward or rightward lateral load applied to the handle,
wherein when it is determined that the main body is in the rearward tilted state, the control unit determines a turning direction of the main body based on a direction of the lateral load, and performs turn assist control to set a rotational speed difference between the left and right travel motors such that a rotational speed of the travel motor on a turning direction side is lower than a rotational speed of the other travel motor to assist turning in the turning direction.

3. The power equipment according to claim 1 , wherein when it is determined that the main body is in the rearward tilted state, the control unit determines a turning direction of the main body based on a direction of the yaw rate, and performs turn assist control to set a rotational speed difference between the left and right travel motors such that a rotational speed of the travel motor on a turning direction side is lower than a rotational speed of the other travel motor to assist turning in the turning direction.

4. The power equipment according to claim 2 wherein in the turn assist control, the control unit drive-controls the travel motor such that the main body turns 180 degrees.

5. The power equipment according to claim 2 , wherein the work unit includes a lawn mowing blade rotated by a work motor, and
in the turn assist control, the control unit drive-controls the left and right travel motors such that the main body turns 180 degrees and an amount of lateral displacement of the main body between before and after the turning is less than or equal to a mowing width of the blade.

6. The power equipment according to claim 2 , wherein the work unit includes a tiller blade rotated by a work motor, and
in the turn assist control, the control unit drive-controls the left and right travel motors such that the main body turns 180 degrees and an amount of lateral displacement of the main body between before and after the turning is greater than or equal to a lateral width of the tiller blade.

Assignees

• Honda Motor Co Ltd

Inventors

• Fukano Jun
• Takeda Masato
• Muraoka Keisuke

Classifications

• A01D34/67

  hand-guided by a walking operator · CPC title

• B62D51/06

  Uniaxle walk-type tractors · CPC title

• E01H5/04

  Apparatus propelled by animal or engine power; Apparatus propelled by hand with driven dislodging or conveying {levelling} elements, conveying pneumatically {for the dislodged material}(E01H5/10, E01H5/12 take precedence) · CPC title

• A01B33/02

  with tools on horizontal shaft transverse to direction of travel · CPC title

• A01D34/68

  with motor driven cutters or wheels · CPC title