IP Library Granted Patent US 8,621,833
Granted Patent B2
US 8,621,833 · App. 13/522,177 · Granted Jan 7, 2014

Lawn mowing vehicle with a control unit for the motor

Inventors: Michinori Shida (Yokohama, JP); Ikuo Iwasaki (Yokohama, JP); Fumio Hasegawa (Tokyo, JP); Takaaki Sudoh (Matsumoto, JP); Takushi Kaneko (Matsumoto, JP)
Assignees: IHI Corporation; IHI Shibaura Machinery Corporation
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Quick Facts
Patent No.
US 8,621,833
App. No.
13/522,177
Granted
Jan 7, 2014
Kind
B2
Abstract

A lawn moving vehicle ( 1 ) is for mowing lawn along the travel path of the vehicle. The lawn moving vehicle ( 1 ) includes: at least one electric reel unit having an electric reel ( 22 ) driven by a motor ( 24 ); sensors ( 34 a - 34 c ) for detecting the travel speed of the vehicle; and a control device ( 37 ) for controlling the motor ( 24 ) according to the result of the detection by the sensors ( 34 a - 34 c ) to thereby control the rotational speed of the electric reel ( 22 ) provided to the electric reel unit.

Claims (19)

1. A lawn mowing vehicle that mows a lawn along a travel path, comprising:

at least three wheels;

at least one electric reel unit having a rotating blade driven by a motor;

a speed detection unit detecting a number of revolutions per minute of at least one of the wheels of the vehicle; and

a control unit that controls the motor depending on the detected result of the speed detection unit, thereby controlling a rotational speed of the rotating blade installed on the electric reel unit, wherein

the rotating blade is configured so that a rotational shaft thereof is set in a leftward/rightward direction of the vehicle with respect to a traveling direction, and the control unit obtains the traveling speed of the vehicle on the basis of the number of revolutions per minute of at least one of the wheels of the vehicle detected by the speed detection unit and on the basis of an effective diameter of the at least one of the wheels, the traveling speed v, in kilometers per hour, of the vehicle obtained by the control unit, based upon one wheel of the vehicle, being given by the expression:

v= ( d /10 6 )×π×60× n,

n being the number of revolutions per minute of the one wheel detected by the speed detection unit and d being an effective diameter of the one wheel in millimeters.

2. The lawn mowing vehicle according to claim 1 , wherein,

the at least one of the wheels comprises a plurality of wheels and when the revolutions per minute of each of the plurality of wheels of the vehicle are different, the control unit obtains an average value of the revolutions per minute of the plurality of wheels.

3. The lawn mowing vehicle according to claim 1 , wherein

the control unit controls a rotational speed of the rotating blade on the basis of a number of blades of the electric reel unit and a mowing pitch of the lawn which is arbitrarily set in advance, in addition to the traveling speed obtained by the control unit.

4. The lawn mowing vehicle according to claim 1 , wherein

the control unit controls a rotational speed of the rotating blade so that the rotational speed of the rotating blade is proportional to the traveling speed obtained by the control unit.

5. The lawn mowing vehicle according to claim 1 , wherein

the control unit controls a rotational speed of the rotating blade so that the rotational speed of the rotating blade varies step-by-step with respect to the traveling speed obtained by the control unit.

6. The lawn mowing vehicle according to claim 3 , wherein the control unit controls the rotational speed of the rotating blade, r, in revolutions per minute, so that the value of r is given by the following expression:

r =( v× 10 6 )/( m×p ),

m being the number of blades of the electric reel unit, and p being the mowing pitch of the lawn in millimeters.

Assignments (4)
CHANGE OF NAME Recorded Dec 2, 2025
From: IAT ASAHI LTD.
To: KYOEISHA SHIBAURA INC.
Reel/Frame 073673/0100 →
COMPANY SPLIT Recorded Oct 2, 2025
From: IHI AGRI-TECH CORPORATION
To: IAT ASAHI LTD.
Reel/Frame 073006/0272 →
CHANGE OF NAME AND ADDRESS Recorded Nov 16, 2017
From: IHI SHIBAURA MACHINERY CORPORATION
To: IHI AGRI-TECH CORPORATION
Reel/Frame 044478/0990 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 13, 2012
From: SHIDA, MICHINORI; IWASAKI, IKUO; HASEGAWA, FUMIO; SUDOH, TAKAAKI; KANEKO, TAKUSHI
To: IHI CORPORATION; IHI SHIBAURA MACHINERY CORPORATION
Reel/Frame 028546/0496 →
Priority Claims (4)
JP P2010-005025 · Jan 13, 2010 · national
JP P2010-005026 · Jan 13, 2010 · national
JP P2010-005027 · Jan 13, 2010 · national
JP P2010-005028 · Jan 13, 2010 · national
Continuity (1)
Related Publication 20130047565A1 · Feb 28, 2013