Control system for construction machine

Patent metadata

Field	Value
Publication number	US-9260838-B2
Application number	US-201214111192-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	May 11, 2011
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A fuel-efficient hydraulic fluid has a lower viscosity than a standard hydraulic fluid, a pressure loss decreases, and thus, when control based on a standard model is exercised, the speeds of various actuators increase. However, the speeds need not be increased beyond the speeds of the standard model. Instead, it is preferred that fuel efficiency be improved. As a result, an engine revolution speed decreases by 50 rpm and a pump torque decreases by 5%. This reduces an engine output. Therefore, when a hydraulic fluid is changed from the standard hydraulic fluid to the fuel-efficient hydraulic fluid, the fuel efficiency can be improved while maintaining operability equivalent to that of the standard model. Hence, the fuel efficiency can be improved while maintaining the operability when an item affecting the fuel consumption is replaced. In addition, the settings can be changed with ease by a service technician.

First claim

The invention claimed is:

1. A control system for a construction machine having a plurality of items including an engine, a hydraulic pump driven by the engine, an actuator driven by a hydraulic fluid discharged from the hydraulic pump, and a member driven by the actuator, where at least two items of the plurality of items are each selectively changeable among a plurality of respective item states, the control system comprising:
an interface to respectively select one of the respective item states for each of the at least two items simultaneously; and
a controller configured to set an engine revolution speed and a pump torque in accordance with the respective item states selected according to the interface,
wherein, when the respective item states that have been selected for each of the at least two items have changed, the controller is further configured to set amounts of increase and decrease of the engine revolution speed and amounts of increase and decrease of the pump torque corresponding to the respective item states for the at least two items so that a sum of the increase and decrease of the engine revolution speed and a sum of the increase and decrease of the pump torque do not exceed a predefined upper limit and a predefined lower limit.

2. The control system according to claim 1 , wherein the at least two items include items that affect fuel consumption of the construction machine.

3. The control system according to claim 2 , wherein the at least two items include items that affect weight of a vehicle body.

4. The control system according to claim 2 , wherein the at least two items include at least one item affecting fluid resistance of the hydraulic fluid.

5. The control system according to claim 4 , wherein the at least one item affecting the fluid resistance of the hydraulic fluid is a type of hydraulic fluid.

6. The control system according to claim 4 , wherein the at least one item affecting the fluid resistance of the hydraulic fluid is a hydraulic fluid conduit.

7. The control system according to claim 1 , wherein the interface includes a monitor device and a display screen to respectively select the respective item states for each of the at least two items.

Assignees

• Sawada Shingo
• Ishikawa Kouji
• Satake Hidetoshi
• Satake Takako
• Nishikawa Shinji
• Ooki Takatoshi
• Hitachi Construction Machinery

Inventors

• Sawada Shingo
• Ishikawa Kouji
• Satake Hidetoshi
• Nishikawa Shinji
• Ooki Takatoshi

Classifications

• F15B2211/6658

  Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode · CPC title

• F15B21/082

  with different modes · CPC title

• E02F9/22 Primary

  Hydraulic or pneumatic drives {(for dipper or bucket arm position control E02F3/43, for blade position control for graders E02F3/844; for turntables E02F9/121; for fork-lift trucks B66F9/22)} · CPC title

• F15B2211/20546

  variable capacity · CPC title

• E02F9/2235 Primary

  including an electronic controller · CPC title