Work machine for lessening damage resulting from an object coming into contact with work portion

Patent metadata

Field	Value
Publication number	US-11363756-B2
Application number	US-202017009251-A
Country	US
Kind code	B2
Filing date	Sep 1, 2020
Priority date	Mar 9, 2018
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A work machine determines, when a request to restart an engine is made, whether or not a reason indicated by stop information stored in a memory is a reason related to locking of the work portion. The machine sets an operation mode of the engine and a work portion to a safe mode if it determines that the reason indicated by the stop information is a reason related to locking of the work portion. The safe mode is an operation mode for lessening damage resulting from causing the engine and the work portion to work during the work portion locked or damage resulting from an object coming into contact with the work portion during the engine and the work portion working.

First claim

The invention claimed is:

1. A work machine comprising:
an engine;
a starter motor configured to drive an output shaft of the engine;
a rotary driven by the engine; and
a processor circuitry configured to control the engine; and
a memory configured to store, when the engine has stopped, stop reason information indicating a reason why the engine has stopped, wherein the processor circuitry is further configured to:
determine, when a request to restart the engine is made, whether or not the stop reason information stored in the memory indicates that the engine has stopped due to locking of the rotary; and
set an operation mode of the engine and the rotary to a safe mode if the processor circuitry determines that the stop reason information indicates that the engine has stopped due to locking of the rotary,
wherein the safe mode is an operation mode for lessening damage to the engine and the rotary resulting from an object coming into contact with the rotary, and

wherein the processor circuitry is configured to, when in the safe mode, set the engine to a cylinder-pause state, and drive the output shaft using the starter motor,
an increase rate of the number of rotations of the starter motor in the safe mode is lower than an increase rate of the number of rotations of the starter motor in a normal mode, and
the normal mode is an operation mode that is applied when the stop reason information indicates that the engine has stopped due to a reason other than locking of the rotary.

2. The work machine according to claim 1 , further comprising
a height adjuster configured to adjust a ground height of the rotary,
wherein, when in the safe mode, the processor circuitry controls the height adjuster and gradually lowers the ground height of the rotary from a first ground height to a second ground height.

3. The work machine according to claim 1 , further comprising:
a drive wheel; and
a drive wheel motor configured to rotate the drive wheel,
wherein, when in the safe mode, the processor circuitry stops the drive wheel motor.

4. The work machine according to claim 1 , further comprising:
a clutch configured to transmit and cut off motive power from the output shaft of the engine to a power shaft of the rotary, the clutch being provided between the output shaft of the engine and the power shaft; and
a sensor configured to detect an engine speed of the engine,
wherein if, when in the safe mode, the increase rate of the engine speed of the engine detected by the sensor is smaller than a threshold, the processor circuitry switches the clutch from a transmission state to a cutoff state.

5. The work machine according to claim 1 , further comprising
at least one of an LED, a liquid crystal display device, and a sound output device,
wherein the at least one of the LED, the liquid crystal display device, and the sound output device is configured to output a warning for prompting an operator to check a state of the rotary when in the safe mode.

6. The work machine according to claim 1 , wherein
the processor circuitry is further configured to: accept an instruction to stop the engine; and
write, in the memory, the stop reason information indicating that the engine has stopped based on the instruction to stop the engine, when the engine has stopped based on the instruction to stop the engine, and write, in the memory, the stop reason information indicating that the engine has stopped based on locking of the rotary when the engine has stopped without the instruction to stop the engine.

7. The work machine according to claim 1 , wherein
if a cause of locking of the rotary is that a density of work objects is higher than a predetermined density, the processor circuitry increases output of the engine to make the output of the engine greater than that before locking of the rotary occurred.

8. The work machine according to claim 1 , wherein the starter motor is an electric power generator-cum-motor.

9. The work machine according to claim 1 , wherein the rotary is a blade for mowing lawn grass.

10. The work machine according to claim 1 , wherein the rotary is a rotary for cultivating soil.

11. The work machine according to claim 1 , wherein the rotary is an auger for raking out snow.

12. A work machine comprising:
an engine;
a rotary driven by the engine; and
a clutch configured to transmit and cut off motive power from an output shaft of the engine to a power shaft of the rotary, the clutch being provided between the output shaft of the engine and the power shaft;
a sensor configured to detect an engine speed of the engine;
a starter motor configured to drive the output shaft of the engine;
a fuel supply configured to supplying fuel to the engine; and
an ignition device provided in the engine,
a processor circuitry configured to control the engine; and
a memory configured to store, when the engine has stopped, stop reason information indicating a reason why the engine has stopped, wherein the processor circuitry is further configured to:
determine, when a request to restart the engine is made, whether or not the stop reason information stored in the memory indicates that the engine has stopped due to locking of the rotary; and
set an operation mode of the engine and the rotary to a safe mode if the processor circuitry determines that the stop reason information indicates that the engine has stopped due to locking of the rotary,

wherein the safe mode is an operation mode for lessening damage to the engine and the rotary resulting from an object coming into contact with the rotary, and
wherein the processor circuitry sets, when in the safe mode, the engine to a cylinder-pause state, starts driving the output shaft using the starter motor, starts supplying fuel to the engine using the fuel supply and causes the ignition device to start ignition upon the engine speed of the engine detected by the sensor reaching a first value, and switches the clutch from a cutoff state to a transmission state upon the engine speed of the engine detected by the sensor reaching a second value.

13. A work machine comprising:
an engine;
an electric power generator driven by the engine to generate electric power;
a rotary driven by the engine; and
a processor circuitry configured to control the engine; and
a memory configured to store, when the engine has stopped, stop reason information indicating a reason why the engine has stopped, wherein the processor circuitry is further configured to:
determine, when a request to restart the engine is made, whether or not the stop reason information stored in the memory indicates that the engine has stopped due to locking of the rotary; and
set an operation mode of the engine and the rotary to a safe mode if the processor circuitry determines that the stop reason information indicates that the engine has stopped due to locking of the rotary,

wherein the safe mode is an operation mode for lessening damage to the engine and the rotary resulting from an object coming into contact with the rotary,
wherein the processor circuitry is further configured to:
acquire an absolute value of an inclination of an engine speed of the engine when the engine speed of the engine lowers;
judge, based on the absolute value of the inclination, whether or not a cause of locking of the rotary is a collision of a foreign object with the rotary;
write, in the memory, the stop reason information indicating that the cause of locking of the rotary is a collision of a foreign object with the rotary; and
detect deformation of the rotary based on an amount of change in an output voltage of the electric power generator in the

Assignees

• Honda Motor Co Ltd

Inventors

• Kuriyagawa Koji

Classifications

• F02N2300/2011

  Control involving a delay; Control involving a waiting period before engine stop or engine start · CPC title

• F02N11/0837

  Environmental conditions thereof, e.g. traffic, weather or road conditions · CPC title

• F02N2200/043

  Starter voltage · CPC title

• A01D34/006 Primary

  Control or measuring arrangements · CPC title

• A01D34/54

  Cutting-height adjustment · CPC title