ENGINE CONTROL APPARATUS FOR WORK MACHINE AND ENGINE CONTROL METHOD THEREOF

• US 20150135693A1
• Filed: 05/31/2013
• Published: 05/21/2015
• Est. Priority Date: 05/31/2013
• Status: Active Grant

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Murakami, Kentaro, Kawaguchi, Tadashi
• Granted Patent: US 9,494,169 B2
• Time in Patent Office: Days
• US Class Current: 60/327
• CPC Class Codes: E02F 9/2012 Setting the functions of the control levers, e.g. changing assigned functions among operations levers, setting functions dependent on the operator or seat orientation
• CPC Class Codes: E02F 9/2066 of the type combustion engines
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: F02D 29/04 peculiar to engines driving pumps
• CPC Class Codes: F15B 13/01 Locking-valves or other detent i.e. load-holding devices
• CPC Class Codes: F15B 13/14 Special measures for giving the operating person a "feeling" of the response of the actuated device
• CPC Class Codes: F15B 21/08 Servomotor systems incorporating electrically operated control means F15B21/02, F15B21/065 take precedence
• CPC Class Codes: F15B 21/082 with different modes
• CPC Class Codes: F15B 21/087 Control strategy, e.g. with block diagram
• CPC Class Codes: F15B 2211/20523 Internal combustion engine
• CPC Class Codes: F15B 2211/20546 variable capacity
• CPC Class Codes: F15B 2211/20576 with multiple pumps
• CPC Class Codes: F15B 2211/40 Flow control
• CPC Class Codes: F15B 2211/63 Electronic controllers
• CPC Class Codes: F15B 2211/6309 the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/633 representing a state of the prime mover, e.g. torque or rotational speed
• CPC Class Codes: F15B 2211/6333 representing a state of the pressure source, e.g. swash plate angle
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6651 Control of the prime mover, e.g. control of the output torque or rotational speed
• CPC Class Codes: F15B 2211/6658 : Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
• CPC Class Codes: F15B 2211/72 : having locking means
• CPC Class Codes: F15B 2211/75 : Control of speed of the output member

Abstract

The present invention includes an information generator to set a lever manipulation amount total sum decrease flag during a period when a lever manipulation amount total sum is decreasing, a first processor to process an engine actual output, an engine actual output latching function block to output the maximum value of the engine actual output until the present during a period in which a lever manipulation amount total sum decrease flag is not set, and output the present engine actual output during a period in which the flag is set, a second processor to output an engine target output based on the engine output, and a controller to control the engine speed under limitation of the engine target output.

Claims

1. An engine control apparatus of a work machine including an engine, a work apparatus driven by at least engine power and a manipulating lever which operates at least an operation of the work apparatus, the apparatus comprising:

an engine output decrease allowing information generating unit configured to generate an engine output decrease allowing information which allows decrease in an engine output during a period in which a lever manipulation amount total sum of the manipulating lever is decreasing;

an engine actual output processing unit configured to process an engine actual output based on engine torque and an engine speed;

a latching function unit configured to keep and output a maximum value of the engine actual output until present during a period in which the engine output decrease allowing information is not generated, and output a present value of the engine actual output during a period in which the engine output decrease allowing information is generated;

an engine target output processing unit configured to process and output an engine target output based on an engine output which is output by the latching function unit; and

an engine controller configured to control the engine speed under limitation of the engine target output.

2. The engine control apparatus of a work machine according to claim 1, wherein the engine output decrease allowing information generating unit includes a hysteresis processing unit configured to carry out hysteresis processing in which when an amount of change in a decreasing-direction of the lever manipulation amount total sum which is input is equal to, or greater than, a predetermined amount, under a state in which the engine output decrease allowing information is not generated, the lever manipulation amount total sum is determined to have decreased so that the engine output decrease allowing information is generated, and when an amount of change in an increasing-direction of the lever manipulation amount total sum which is input is equal to, or greater than, a predetermined amount, under a state in which the engine output decrease allowing information is generated, the lever manipulation amount total sum is determined to have increased so that the engine output decrease allowing information is not generated.

3. The engine control apparatus of a work machine according to claim 1, wherein the engine output decrease allowing information generating unit is configured not to generate the engine output decrease allowing information when pump pressure exceeds a predetermined high pressure threshold.

4. The engine control apparatus of a work machine according to claim 1 further comprising

a single touch power-up button configured to output a single touch power-up signal which gives a command to temporarily increase the engine output, wherein the engine output decrease allowing information generating unit is configured not to generate the engine output decrease allowing information during a period when the single touch power-up button signal is input.

5. The engine control apparatus of a work machine according to claim 1, wherein the engine target output processing unit is configured not to carry out processing in a direction in which an engine target output increases when the engine output decrease allowing information is generated.

6. An engine control method for a work machine including an engine, a work apparatus driven by at least engine power, and a manipulating lever which operates at least an operation of the work apparatus, the method comprising:

an engine output decrease allowing information generating step in which an engine output decrease allowing information which allows decrease in an engine output during a period when a lever manipulation amount total sum of a manipulating lever is decreasing is generated;

an engine actual output processing step in which an engine actual output is processed based on engine torque and an engine speed;

a latching function step in which a maximum value of the engine actual output until present is kept and output during a period when the engine output decrease allowing information is not generated, and a present value of the engine actual output is output during a period when the engine output decrease allowing information is generated;

an engine target output processing step in which an engine target output is processed and output based on an engine output which is output by the latching function step; and

an engine control step in which the engine speed is controlled under limitation of the engine target output.

7. The engine control method for a work machine according to claim 6, wherein the engine output decrease allowing information generating step includes a hysteresis processing step which carries out hysteresis processing in which when an amount of change in a decreasing-direction of the lever manipulation amount total sum which is input is equal to, or greater than, a predetermined amount, under a state in which the engine output decrease allowing information is not generated, the lever manipulation amount total sum is determined to have decreased so that the engine output decrease allowing information is generated, and when an amount of change in an increasing-direction of the lever manipulation amount total sum which is input is equal to, or greater than, a predetermined amount, under a state in which the engine output decrease allowing information is generated, the lever manipulation amount total sum is determined to have increased so that the engine output decrease allowing information is not generated.