IP Library › Granted Patent US 11,641,798
Granted Patent B2
US 11,641,798 · App. 16/787,140 · Granted May 9, 2023

Electric working machine capable of determining type of tip tool

Inventor: Yoshitaka Ichikawa (Anjo, JP)
Assignee: MAKITA CORPORATION
A01D34/78A01D34/6806B25F3/00B25F5/001A01D34/416A01D2101/00
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Quick Facts
Patent No.
US 11,641,798
App. No.
16/787,140
Granted
May 9, 2023
Kind
B2
Abstract

An electric working machine includes an attachment portion, a motor, and a controller. Multiple types of tip tools are alternatively attached to the attachment portion. The motor drives the tip tool attached to the attachment portion. The controller has first start control and second start control. The controller is configured to execute the first start control so as to determine the type of the tip tool when not having tool type information, and configured to execute the second start control when having the tool type information.

Claims (50)

1. An electric working machine comprising:

an attachment portion to which multiple types of tip tools are alternatively attached;

a motor that drives a tip tool attached to the attachment portion; and

a control circuit configured to execute a first start control in which the motor is started and controlled with a first parameter, and a second start control in which the motor is started and controlled with a second parameter, the second parameter being different from the first parameter, the control circuit being configured to execute the first start control to determine a type of the tip tool in response to not having tool type information on the tip tool, and the control circuit being configured to execute the second start control in response to having the tool type information, wherein

an increase per unit time in rotation speed of the motor is set as an increase in rotation speed,

the first parameter includes an increase in first rotation speed, the increase in the first rotation speed being an increase in the rotation speed at the time of rotating the motor during execution of the first start control by the control circuit,

the second parameter includes an increase in second rotation speed, the increase in the second rotation speed being an increase in the rotation speed at the time of rotating the motor during execution of the second start control by the control circuit, and

the increase in the first rotation speed is larger than the increase in the second rotation speed.

2. The electric working machine according to claim 1 ,

wherein the control circuit is configured to detect a determination parameter set in advance to determine the type of the tip tool, and determine the type of the tip tool by determining whether the determination parameter exceeds a preset tip tool determination value during execution of the first start control.

3. The electric working machine according to claim 1 , further comprising:

a rotation speed manipulator configured to be manipulated by an operator to set rotation speed of the motor,

wherein, in the first start control, manipulation performed on the rotation speed manipulator is disabled.

4. The electric working machine according to claim 1 , further comprising:

a driving operating portion configured to be manipulated by an operator to switch between driving and stopping the motor,

wherein, in the first start control, manipulation on other portions than the driving operating portion is disabled.

5. The electric working machine according to claim 1 ,

wherein the electric working machine is a grass cutter.

6. The electric working machine according to claim 1 ,

wherein a target value of rotation speed of the motor is set as target rotation speed,

wherein the target rotation speed at the time of rotating the motor during execution of the first start control by the control circuit is set as first target rotation speed,

wherein the target rotation speed at the time of rotating the motor during execution of the second start control by the control circuit is set as second target rotation speed, and

wherein a maximum value of the first target rotation speed is smaller than a maximum value of the second target rotation speed.

7. The electric working machine according to claim 2 ,

wherein the determination parameter is one of electric current flowing to the motor, an increase rate in the electric current, rotation speed of the motor, an increase rate in the rotation speed, a duty ratio of a PWM signal for drive control of the motor, or vibration.

8. An electric working machine comprising:

an attachment portion to which multiple types of tip tools are alternatively attached;

a motor that drives a tip tool attached to the attachment portion; and

a control circuit configured to execute A first start control in which the motor is started and controlled with a first parameter, and A second start control in which the motor is started and controlled with a second parameter, the second parameter being different from the first parameter, the control circuit being configured to execute the first start control at initial startup following power supply to determine a type of the tip tool, and the control circuit being configured to execute the second start control at startup after execution of the first start control following the power supply, wherein

an increase per unit time in rotation speed of the motor is set as an increase in rotation speed,

the first parameter includes an increase in first rotation speed, the increase in the first rotation speed being an increase in the rotation speed at the time of rotating the motor during execution of the first start control by the control circuit,

the second parameter includes an increase in second rotation speed, the increase in the second rotation speed being an increase in the rotation speed at the time of rotating the motor during execution of the second start control by the control circuit, and

the increase in the first rotation speed is larger than the increase in the second rotation speed.

9. The electric working machine according to claim 8 ,

wherein the control circuit is configured to detect a determination parameter set in advance to determine the type of the tip tool, and determine the type of the tip tool by determining whether the determination parameter exceeds a preset tip tool determination value during execution of the first start control.

10. The electric working machine according to claim 8 , further comprising:

a rotation speed manipulator configured to be manipulated by an operator to set rotation speed of the motor,

wherein, in the first start control, manipulation performed on the rotation speed manipulator is disabled.

11. The electric working machine according to claim 8 , further comprising:

a driving operating portion configured to be manipulated by an operator to switch between driving and stopping the motor,

wherein, in the first start control, manipulation on other portions than the driving operating portion is disabled.

12. The electric working machine according to claim 8 ,

wherein the electric working machine is a grass cutter.

13. The electric working machine according to claim 8 ,

wherein a target value of rotation speed of the motor is set as target rotation speed,

wherein the target rotation speed at the time of rotating the motor during execution of the first start control by the control circuit is set as first target rotation speed,

wherein the target rotation speed at the time of rotating the motor during execution of the second start control by the control circuit is set as second target rotation speed, and

wherein a maximum value of the first target rotation speed is smaller than a maximum value of the second target rotation speed.

14. The electric working machine according to claim 9 ,

wherein the determination parameter is one of electric current flowing to the motor, an increase rate in the electric current, rotation speed of the motor, an increase rate in the rotation speed, a duty ratio of a PWM signal for drive control of the motor, or vibration.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 11, 2020
From: ICHIKAWA, YOSHITAKA
To: MAKITA CORPORATION
Reel/Frame 051780/0653 →
Priority Claims (1)
JP JP2019-026397 · Feb 18, 2019 · national
Continuity (1)
Related Publication 20200260644A1 · Aug 20, 2020