Working machine and method of braking driving device of working machine

Patent metadata

Field	Value
Publication number	US-2018092298-A1
Application number	US-201715724438-A
Country	US
Kind code	A1
Filing date	Oct 4, 2017
Priority date	Oct 5, 2016
Publication date	Apr 5, 2018
Grant date	—

Abstract

A working machine according to one aspect of the present disclosure comprises an operating device, a working tool, a driving device, a braking device, a detection device, and a change device. The detection device detects a mode of an operation performed on the operating device. The change device changes a brake control to be performed by the braking device according to the mode detected by the detection device.

First claim

What is claimed is:

1 . A working machine comprising:
an operating device configured to be operated by an operator of the working machine; a working tool configured to perform a work using a rotational force; a driving device configured to rotationally drive the working tool in response to an operation performed on the operating device; a braking device configured to perform a brake control that reduces a rotational speed of the driving device if the operation performed on the operating device is an off operation in which non-driving of the driving device is commanded to the driving device; a detection device configured to detect a mode of the operation performed on the operating device; and a change device configured to change the brake control according to the mode detected by the detection device.

2 . The working machine according to claim 1 ,
wherein the detection device is configured to detect, as the mode, a duration of an on operation in which driving of the driving device is commanded to the driving device, and wherein the change device is configured to change the brake control to a normal brake control if the duration of the on operation detected by the detection device is longer than a threshold on time that has been preset, the normal brake control being a brake control that uses a normal braking force that has been preset.

3 . The working machine according to claim 2 ,
wherein the detection device is further configured to detect a duration of the off operation as the mode, and wherein the change device is configured to, in a case where the duration of the on operation detected by the detection device is equal to or shorter than the threshold on time, (i) change the brake control to the normal brake control if the duration of the off operation detected by the detection device is longer than a threshold off time that has been preset, and (ii) change the brake control, to a weak brake control if the duration of the off operation is equal to or shorter than the threshold off time, the weak brake control being a brake control that uses a braking force weaker than the normal braking force.

4 . The working machine according to claim 3 ,
wherein the threshold off time is set to be longer than a standard duration of the off operation for an intermittent operation, the intermittent operation being an operation in which the on operation and the off operation are repeated alternately to control a rotational speed of the working tool.

5 . The working machine according to claim 2 ,
wherein the threshold on time is set to be longer than a standard duration of the on operation for an intermittent operation, the intermittent operation being an operation in which the on operation and the off operation are repeated alternately to control a rotational speed of the working tool.

6 . The working machine according to claim 1 ,
wherein the driving device comprises an electric motor.

7 . The working machine according to claim 6 ,
wherein the brake control uses free running that opens an excitation current path to the electric motor and/or short-circuit braking that short-circuits the excitation current path to the electric motor.

8 . A method of braking a driving device of a working machine, the method comprising:
performing a brake control that reduces a rotational speed of the driving device if an operation performed on an operating device of the working machine is an off operation in which non-driving of the driving device is commanded to the driving device; detecting a mode of the operation performed on the operating device; and changing the brake control according to the mode detected.

Assignees

• Makita Corp

Inventors

• Takahashi Yuji
• Takeda Kouichi

Classifications

• A01D34/006 Primary

  Control or measuring arrangements · CPC title

• A01D34/84

  for edges of lawns or fields, e.g. for mowing close to trees or walls ({for embankments A01D34/86 takes precedence;} edge trimmers A01G3/00) · CPC title

• A01G23/08

  Felling trees · CPC title

• A01G3/088

  Circular saws · CPC title

• A01D34/90

  for carrying by the operator · CPC title