CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE, WORK MACHINE AND CONTROL METHOD OF INTERNAL COMBUSTION ENGINE

• US 20150300270A1
• Filed: 07/23/2013
• Published: 10/22/2015
• Est. Priority Date: 07/23/2013
• Status: Active Grant

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Murakami, Kentaro
• Granted Patent: US 9,273,615 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2200/0625 Fuel consumption, e.g. measured in fuel liters per 100 kms or miles per gallon
• CPC Class Codes: F02D 2700/0284 by acting on the fuel pump control element
• CPC Class Codes: F02D 29/04 peculiar to engines driving pumps
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/3809 Common rail control systems common rail apparatus F02M55/025, F02M63/0225
• CPC Class Codes: F02D 41/406 Electrically controlling a diesel injection pump F02D41/401 takes precedence
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor

Abstract

When an internal combustion engine that is provided in a work machine and that serves as a power source for the work machine is controlled, the following lines are used: a first equal throttle line which is defined to correspond to a case where an amount of fuel injection for the internal combustion engine is maximum where the rotation speed of the internal combustion engine is the same and so that an output of the internal combustion engine becomes constant, a second equal throttle line which is defined to correspond to a case where the amount of fuel injection for the internal combustion engine is zero where the rotation speed of the internal combustion engine is the same and so that the torque decreases with increase of the rotation speed, and a third equal throttle line which is obtained from the first equal throttle line and the second equal throttle line.

Claims

1. A control device of an internal combustion engine, wherein when the control device controls the internal combustion engine that is provided in a work machine and that serves as a power source for the work machine,

the control device controls driving state of the internal combustion engine by using:

a first relationship of a torque and a rotation speed of the internal combustion engine which is defined to correspond to a case where an amount of fuel injection for the internal combustion engine is maximum at each rotation speed of the internal combustion engine and so that an output at a rotation speed to generate a rated output of the internal combustion engine is equal to or more than the rated output;

a second relationship of the torque and the rotation speed of the internal combustion engine which is defined to correspond to a case where the amount of fuel injection for the internal combustion engine is zero at each rotation speed of the internal combustion engine and so that the torque of the internal combustion engine decreases in accordance with increase of the rotation speed of the internal combustion engine, where a point where the torque and the rotation speed of the internal combustion engine are zero is defined as a start point; and

a third relationship which is a relationship of the torque and the rotation speed of the internal combustion engine, which is obtained from the first relationship and the second relationship.

2. The control device of the internal combustion engine according to claim 1, wherein the driving state of the internal combustion engine is controlled using the third relationship that matches:

a fourth relationship of the torque and the rotation speed of the internal combustion engine which is defined so that an output of the internal combustion engine becomes constant; and

a fifth relationship of the torque and the rotation speed of the internal combustion engine which is set so that a fuel consumption rate with respect to the output of the internal combustion engine becomes the smallest.

3. The control device of the internal combustion engine according to claim 2, wherein the driving state of the internal combustion engine is controlled so as to attain the rotation speed and the torque where the third relationship matches the fifth relationship.

4. The control device of the internal combustion engine according to claim 1, wherein further, the driving state when a load of the internal combustion engine decreases is controlled using a sixth relationship of the torque and the rotation speed of the internal combustion engine, which is defined from a no-load maximum rotation speed which is a maximum rotation speed of the internal combustion engine when the load of the work machine decreases.

5. The control device of the internal combustion engine according to claim 4, wherein the sixth relationship is a relationship in which, as the rotation speed increases, the torque decreases.

6. The control device of the internal combustion engine according to claim 1, wherein the first relationship is defined to attain an output larger than an upper limit value that can be actually output by the internal combustion engine.

12. The work machine according to claim 1, comprising:

the internal combustion engine;

an electric power generator motor driven by the internal combustion engine;

a battery device accumulating electric power;

an electric motor that is driven by receiving the electric power discharged from the battery device or electric power generated by the electric power generator motor.

7. A work machine comprising:

an internal combustion engine; and

a control device of the internal combustion engine,

wherein the control device controls driving state of the internal combustion engine by using;

a first relationship of a torque and a rotation speed of the internal combustion engine which is defined to correspond to a case where an amount of fuel injection for the internal combustion engine is maximum at each rotation speed of the internal combustion engine and so that an output at a rotation speed to generate a rated output of the internal combustion engine is equal to or more than the rated output;

a second relationship of the torque and the rotation speed of the internal combustion engine which is defined to correspond to a case where the amount of fuel injection for the internal combustion engine is zero at each rotation speed of the internal combustion engine and so that the torque of the internal combustion engine decreases in accordance with increase of the rotation speed of the internal combustion engine, where a point where the torque and the rotation speed of the internal combustion engine are zero is defined as a start point; and

a third relationship which is a relationship of the torque and the rotation speed of the internal combustion engine, which is obtained from the first relationship and the second relationship, and

wherein the driving state of the internal combustion engine is controlled using the third relationship that matches;

a fourth relationship of the torque and the rotation speed of the internal combustion engine which is defined so that an output corresponding to a command value of an output of the internal combustion engine becomes constant; and

a fifth relationship of the torque and the rotation speed of the internal combustion engine which is set so that a fuel consumption rate with respect to the output of the internal combustion engine becomes the smallest, and

wherein further, the driving state when a load of the internal combustion engine decreases is controlled using a sixth relationship of the torque and the rotation speed of the internal combustion engine, which is defined from a no-load maximum rotation speed which is a maximum rotation speed of the internal combustion engine when the load of the work machine decreases.

8. The work machine according to claim 7, comprising:

the internal combustion engine;

an electric power generator motor driven by the internal combustion engine;

a battery device accumulating electric power;

an electric motor that is driven by receiving the electric power discharged from the battery device or electric power generated by the electric power generator motor.

9. A control method of an internal combustion engine, wherein when the internal combustion engine that is provided in a work machine and that serves as a power source for the work machine is controlled, the control method comprising:

detecting driving state of the work machine, and

based on the detected driving state, controlling the driving state of the internal combustion engine by using;

a first relationship of a torque and a rotation speed of the internal combustion engine which is defined to correspond to a case where an amount of fuel injection for the internal combustion engine is maximum at each rotation speed of the internal combustion engine and so that an output at a rotation speed to generate a rated output of the internal combustion engine is equal to or more than the rated output;

a second relationship of the torque and the rotation speed of the internal combustion engine which is defined to correspond to a case where the amount of fuel injection for the internal combustion engine is zero at each rotation speed of the internal combustion engine and so that the torque of the internal combustion engine decreases in accordance with increase of the rotation speed of the internal combustion engine, where a point where the torque and the rotation speed of the internal combustion engine are zero is defined as a start point; and

a third relationship which is a relationship of the torque and the rotation speed of the internal combustion engine, which is obtained from the first relationship and the second relationship.

10. The control method of the internal combustion engine according to claim 9, wherein the controlling includes using the third relationship that matches a fourth relationship of the torque and the rotation speed of the internal combustion engine which is defined so that an output of the internal combustion engine becomes constant and a fifth relationship of the torque and the rotation speed of the internal combustion engine which is set so that a fuel consumption rate with respect to the output of the internal combustion engine becomes the smallest to cause the internal combustion engine to generate an output corresponding to the fourth relationship.

11. The control method of the internal combustion engine according to claim 10, wherein the controlling includes controlling the driving state of the internal combustion engine so as to attain the rotation speed and the torque where the third relationship matches the fifth relationship.