Working machine and cooling control system for the same

Patent metadata

Field	Value
Publication number	US-10865692-B2
Application number	US-201816014330-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Dec 24, 2015
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A cooling control system for a working machine includes a fan, a housing to which the fan is attached, a prime mover having an output shall, a rotor to be rotated by a rotating power of the output shaft and to be rotated with the housing by a fluid introduced to a gap formed between the housing and the rotor, a fluid setting circuit to set an introduction amount of the fluid introduced to the gap, and a control device to control the fluid setting circuit to control the fan. The control device includes a setting circuit to set a target rotation speed of the fan based on a responsiveness of an actual rotation speed of the fan at time of changing of the target rotation speed of the fan.

First claim

What is claimed is:

1. A cooling control system for a working machine, comprising:
a fan;
a housing to which the fan is attached;
a prime mover having an output shaft;
a rotor to be rotated together with the housing by a rotating power of the output shaft through a fluid introduced to a gap formed between the housing and the rotor;
a fluid regulator to regulate an amount of the fluid introduced to the gap; and
a controller configured to be controlled by a program to control the fluid regulator to regulate the actual rotation speed of the fan to be matched with a target rotation speed of the fan,
wherein the program causes the controller to,
calculate a target rotation speed (F 1 =E 1 −D) of the fan by subtracting a predetermined speed (D) from an actual rotation speed (E 1 ) of the prime mover
perform a proportional control for the actual rotation speed (F 2 ) of the fan based upon a difference (=F 1 −F 2 ) between the target rotation speed of the fan and the actual rotation speed of the fan,
perform an integral control for the actual rotation speed (F 2 ) of the fan based upon the difference (=F 1 −F 2 ),
perform a differential control for the actual rotation speed (F 2 ) of the fan based upon the difference (=F 1 −F 2 ), and
selectively deactivate one or two of the proportional control step, the integral control step, and the differential control step in accordance with the actual rotation speed of the prime mover.

2. A working machine, comprising:
the cooling control system according to claim 1 .

3. The cooling control system according to claim 1 , wherein the program causes the controller to deactivate, in the selectively deactivating step, the integral control step and the differential control step until the actual rotation speed of the prime mover reaches a predetermined rotation speed after starting the prime mover.

4. The cooling control system according to claim 1 , wherein the program causes the controller to deactivate, in the selectively deactivating step, the integral control step and the differential control step when a first speed gap between the actual rotation speed of the prime mover and the actual rotation speed of the fan is kept less than a first threshold speed and then the actual rotation speed of the prime mover is increased.

5. The cooling control system according to claim 1 , wherein the program causes the controller to deactivate, in the selectively deactivating step, the integral control step after the actual rotation speed of the prime mover is decreased so that a second speed gap between the actual rotation speed of the prime mover and the actual rotation speed of the fan is kept less than a second threshold speed.

6. A cooling control system for a working machine, comprising:
a prime mover having an output shaft;
a fan to be rotated by a rotating force of the output shaft;
a first detector to detect an actual rotation speed of the prime mover;
a second detector to detect an actual rotation speed of the fan; and
a controller controlled by a program to:
perform a proportional control for the actual rotation speed of the fan based on of a difference between the actual rotation speed of the fan and a target rotation speed of the fan;
perform an integral control for the actual rotation speed of the fan based on the difference;
perform a differential control for the actual rotation speed of the fan based on the difference; and
selectively deactivate one or two of the proportional control step, the integral control step, and the differential control step based on a state of either one of the prime mover and the fan.

7. The cooling control system according to claim 6 ,
wherein the program causes the controller to deactivate, in the selectively deactivating step, the integral control step and the differential control step at a time of starting the prime mover.

8. The cooling control system according to claim 7 ,
wherein the program causes the controller to deactivate, in the selectively deactivating step, the integral control step and the differential control step when the actual rotation speed of the fan is higher than a threshold value, the threshold value being a difference between the actual rotation speed of the prime mover and a predetermined rotation speed.

9. The cooling control system according to claim 7 ,
wherein, in the selectively deactivating step, the program causes the controller to deactivate, at the time of starting the prime mover, the integral control step and differential control step when the actual rotation speed of the fan is higher than a threshold value, the threshold value being a difference between the actual rotation speed of the prime mover and a predetermined rotation speed, and to activate the integral control step and the differential control step when the actual rotation speed of the fan is equal to or less than the threshold value.

10. The cooling control system according to claim 7 ,
wherein, in the selectively deactivating step, the program causes the controller to deactivate the integral control step when the target rotation speed of the fan is changed by a predetermined speed or more.

11. The cooling control system according to claim 7 , further comprising:
a housing to which the fan is attached;
a rotor to be rotated together with the housing by a rotating power of the output shaft through a fluid introduced to a gap formed between the housing and the rotor; and
a fluid regulator to regulate an amount of the fluid introduced to the gap.

12. A cooling control system for a working machine, comprising:
a prime mover having an output shaft;
a fan to be rotated by a rotating force of the output shaft;
a second detector to detect an actual rotation speed of the fan;
a controller configured to be controlled by a program to,
generate an interpolation-trajectory based on a target rotation speed of the fan and a polynomial interpolation equation, the interpolation-trajectory extending from the actual rotation speed to the target rotation speed of the fan; and
control an actual rotation speed of the fan based on the generated interpolation-trajectory until the actual rotation speed of the fan reaches the target rotation speed of the fan.

13. The cooling control system according to claim 12 ,
wherein the program causes the controller to control the actual rotation speed of the fan based on a difference between the actual rotation speed of the fan and a rotation speed of the fan obtained from the generated interpolation trajectory in a predetermined time.

14. The cooling control system according to claim 13 ,
wherein the program causes the controller to:
perform a proportional control of the difference;
perform an integral control of the difference; and
perform a differential control of the difference.

15. The cooling control system according to claim 12 ,
wherein, in the interpolation-trajectory generating step, the controller sets a decreasing interpolation trajectory in changing a rotating direction of the fan from a direction of the normal rotation to a direction of the inverse rotation, the decreasing interpolation trajectory being the interpolation trajectory that decreases the rotation speed of normal rotation of the fan,
and wherein the program causes the controller to control the actual rotation speed of the fan based on the decreasing interpolation trajectory.

16. The cooling control system according to claim 15 ,
wherein program causes the controller to set an increasing interpolation trajectory in a case where the rotation speed of the inverse rotation of the fan is in

Assignees

• Kubota Kk

Inventors

• Kinugawa Ryosuke
• MINAGAWA Nozomu
• Tatsumi Hiroshi
• Miura Keisuke
• Noguchi Makoto

Classifications

• F01P2031/20

  Warning devices · CPC title

• F05B2260/406

  through hydraulic systems · CPC title

• F01P2025/36

  Heat exchanger mixed fluid temperature · CPC title

• F05B2270/706

  proportional-integral-differential · CPC title

• F16D35/024

  the valve being actuated electrically, e.g. by an electromagnet (F16D35/026 takes precedence) · CPC title