Construction machine

• US 7,661,499 B2
• Filed: 11/30/2005
• Issued: 02/16/2010
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Matsuyama, Nobuo
• Primary Examiner(s): Morris; Lesley
• Assistant Examiner(s): Evans; Bryan A
• Application Number:
  US11/792,278
• Publication Number:
  US 20080093145A1
• Time in Patent Office: 1,539 Days
• Field of Search: 180/170, 180/171, 180/173, 180/174, 180/197, 701/50, 701/99, 701/110
• US Class Current: 180/174
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/604 Engine control mode selected by driver, e.g. to manually start particle filter regeneration or to select driving style
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02D 41/04 Introducing corrections for particular operating conditions F02D41/14 takes precedence

Abstract

A construction machine capable of increasing a frictional force and an acceleration performance without causing unwanted slip and an excessive load to a transmission by a driving force. The construction machine comprises a first mode to set the maximum output of an engine to a prescribed output, a second mode to limit the maximum output of the engine to an output lower than the prescribed output and a mode selector switch used for a operator to select from the plurality of modes. The construction machine also comprises control means that controls the machine to operate in the second mode regardless of the mode selected by the mode selector switch when a vehicle speed is equal to or less than a prescribed speed and the opening of an accelerator is equal to or more than a prescribed opening.

Claims

1. A construction machine that includes a first mode in which a maximum output of an engine is a prescribed output, a second mode in which the maximum output of the engine is limited to an output less than the prescribed output, and a mode selector switch for enabling an operator to select from the plurality of modes, the construction machine comprising:

an accelerator for enabling the operator to adjust an engine speed of the engine, traveling speed detecting means that detects a traveling speed, and

a controller that, when the first mode is selected by means of the mode selector switch and the traveling speed detected by the traveling speed detecting means is a prescribed speed or slower and an opening degree of the accelerator is a prescribed opening degree or larger, controls an operation in the second mode regardless of the mode selected by the mode selector switch wherein

maximum driving force at the time when the second mode is selected is set to a value that does not exceed an appropriate maximum driving force, and wherein

each of the prescribed speed and the prescribed opening degree is set such that the driving force at the time when the first mode is selected does not exceed the maximum driving force at the time when the second mode is selected.

2. A construction machine that includes a first mode in which a maximum engine speed of an engine is a prescribed speed, a second mode in which the maximum engine speed of the engine is limited to a speed less than the prescribed speed, and a mode selector switch for enabling an operator to select from the plurality of modes, the construction machine comprising:

an accelerator for enabling the operator to adjust an engine speed of the engine,

traveling speed detecting means that detects a traveling speed, and

a controller that, when the first mode is selected by means of the mode selector switch and the traveling speed detected by the traveling speed detecting means is a prescribed speed or slower and an opening degree of the accelerator is a prescribed opening degree or larger, controls an operation in the second mode regardless of the mode selected by the mode selector switch wherein

maximum driving force at the time when the second mode is selected is set to a value that does not exceed an appropriate maximum driving force, and wherein

each of the prescribed speed and the prescribed opening degree is set such that the driving force at the time when the first mode is selected does not exceed the maximum driving force at the time when the second mode is selected.

3. A construction machine that includes a first mode in which an engine is operated under a first torque curve, a second mode in which the engine is operated under a second torque curve that is lower than the first torque curve, and a mode selector switch for enabling an operator to select from the plurality of modes, the construction machine comprising:

an accelerator for enabling the operator to adjust an engine speed of the engine,

traveling speed detecting means that detects a traveling speed, and

a controller that, when the first mode is selected by means of the mode selector switch and the traveling speed detected by the traveling speed detecting means is a prescribed speed or slower and an opening degree of the accelerator is a prescribed opening degree or larger, controls an operation in the second mode regardless of the mode selected by the mode selector switch wherein

maximum driving force at the time when the second mode is selected is set to a value that does not exceed an appropriate maximum driving force, and wherein

each of the prescribed speed and the prescribed opening degree is set such that the driving force at the time when the first mode is selected does not exceed the maximum driving force at the time when the second mode is selected.