Apparatus for improving the operating capability of a construction machine during a fine operation mode and method for the same

• US 5,950,428 A
• Filed: 12/11/1997
• Issued: 09/14/1999
• Est. Priority Date: 05/31/1997
• Status: Expired due to Fees

• Current Assignee: Volvo Construction Equipment Holding Sweden AB
• Original Assignee: Volvo Construction Equipment Korea Co., Ltd. (AB Volvo)
• Inventors: Nam, In Taek, Hwang, Geon, Song, Myung Hoon
• Primary Examiner(s): LOPEZ, FRANK D
• Application Number:
  US08/989,050
• Time in Patent Office: 642 Days
• Field of Search: 60/421, 60/429, 60/430
• US Class Current: 60/421
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• CPC Class Codes: E02F 9/2221 Control of flow rate; Load sensing arrangements E02F9/2203 take precedence over E02F9/2221
• CPC Class Codes: E02F 9/226 Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence

Abstract

Disclosed is an apparatus for increasing the operating capability of a construction machine during a fine operation mode and a method for the same. The apparatus being capable of preventing a merged hydraulic fluid from being supplied into a hydraulic actuator and increasing the pressure of the hydraulic fluid being supplied into the hydraulic actuator during the fine operation mode. The apparatus includes a detector that detects the RPM count of the engine of the construction machine and determines whether the engine is switched into the fine operation mode. A first anti-confluence valve and a second anti-confluence valve prevent a first hydraulic fluid supplied into the first actuator and a second hydraulic fluid supplied into the second actuator from merging while either the first actuator or the second actuator is operating. An anti-confluence relay turns the first anti-confluence valve and the second anti-confluence valve on/off. Finally, a controller turns the anti-confluence relay on/off in accordance with a signal generated by the detector.

Claims

1. An apparatus for improving an operating capability of a construction machine during a fine operation mode including an engine, a first pump and a second pump being driven by the engine, a first actuator being driven by the first pump and a second actuator being driven by the second pump, the apparatus comprising:

detecting means for detecting a RPM count of an engine of the construction machine in order to determine whether said engine is switched to the fine operation mode;

a first anti-confluence valve and a second anti-confluence valve for preventing a first hydraulic fluid supplied into a first actuator and a second hydraulic fluid supplied into a second actuator from merging together during operation of either said first actuator or said second actuator in the fine operation mode;

an anti-confluence relay for turning said first anti-confluence valve and said second anti-confluence valve on/off; and

a controller for turning said anti-confluence relay on/off in accordance with a signal generated by said detecting means.

2. The apparatus according to claim 1, further comprising:

valve means for intensifying a pressure of said first hydraulic fluid or a pressure of said second hydraulic fluid during operation of the engine in the fine operation mode; and

a pressure-intensifying relay for turning said valve means on/off, said pressure-intensifying relay being connected to said valve means and said controller.

3. A method for improving an operating capability of a construction machine during a fine operation mode, the construction machine includes an engine, a first pump and a second pump being driven by the engine, a first actuator being driven by the first pump and a second actuator being driven by the second pump, the method comprising the steps of:

sensing a RPM count of the engine to determine whether the engine is switched to the fine operation mode; and

preventing a first hydraulic fluid supplied into the first actuator and a second hydraulic fluid supplied into the second actuator from merging during the time that either the first actuator or the second actuator operates in the fine operation mode.

4. The method according to claim 3, further comprising the steps of:

increasing a pressure of said first hydraulic fluid or a pressure of said second hydraulic fluid during operation of the engine at the fine operation mode.