Engine control apparatus

• US 8,534,264 B2
• Filed: 09/11/2008
• Issued: 09/17/2013
• Est. Priority Date: 09/19/2007
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Kawaguchi, Tadashi, Morinaga, Jun, Inoue, Hiroaki
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): Castro, Arnold
• Application Number:
  US12/733,726
• Publication Number:
  US 20100186713A1
• Time in Patent Office: 1,832 Days
• Field of Search: 701/50, 123/349, 123/350, 123/351, 123/364, 123/365, 123/367, 123/198.C, 607/01, 607/02, 322/14, 322/15, 322/16, 322/40, 903/905, 903/906
• US Class Current: 123/350
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: F02D 2250/24 : by using an external load, e.g. a generator
• CPC Class Codes: F02D 29/04 : peculiar to engines driving pumps
• CPC Class Codes: F02D 29/06 : peculiar to engines driving electric generators
• CPC Class Codes: F02D 31/001 : Electric control of rotation speed
• CPC Class Codes: F02D 31/006 : for maximum speed control
• CPC Class Codes: F02D 41/0205 : using an auxiliary engine speed control engine speed control per se F02D31/00
• 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: F04B 17/05 : driven by internal-combustion engines
• CPC Class Codes: F04B 2205/05 : Pressure after the pump outlet
• CPC Class Codes: F04B 49/065 : and making use of computers
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

An engine control apparatus includes an engine target speed set unit 51 setting a first target speed through a throttle dial, a relief engine maximum speed calculation unit 52 calculating a second target speed limiting a maximum target speed in a relief operation according to a load pressure of a hydraulic pump, a speed control means controlling an engine speed such that the engine speed is equal to lower one of the first target speed and the second target speed, a determination means determining whether an engine torque assist action of a generator motor is performed, based on a deviation between an target speed and a real speed of the engine. When the determination means determines that the engine torque assist action is performed, the speed control means controls the engine speed to be equal to the target speed through the engine torque assist action of the generator motor.

Claims

1. An engine control apparatus comprising;

a hydraulic pump driven by an engine;

a hydraulic actuator to which pressure oil discharged from the hydraulic pump Is supplied;

an operation unit configured to operate the hydraulic actuator;

a first target speed set unit configured to set a first target speed of the engine by an engine target speed set dial;

a second target speed calculation unit configured to calculate a second target speed limiting a maximum target speed of the engine on a relief state according to increase of a load pressure of the hydraulic pump; and

a speed control unit configured to control an engine speed such that the engine speed Is equal to the lower one of the first target speed and the second target speed.

2. The engine control apparatus according to claim 1, further comprising;

a generator motor connected to an output shaft of the engine;

a storage battery configured to store electric power which the generator motor generates, and to supply electric power to the generator motor; and

a control unit, wherein

when the load pressure of the hydraulic pump is abruptly switched from a high state to a low state, until a real speed of the engine is increased to be equal to or greater than a value preset with respect to the target speed, the control unit uses an engine torque assist action of the generator motor to control the engine speed to be equal to the target speed.

3. The engine control apparatus according to claim 1, further comprising:

a generator motor connected to an output shaft of the engine;

a storage battery configured to store electric power the generator motor generates, and to supply electric power to the generator motor; and

a control unit, wherein

by increase of the second target speed according to a case where the load pressure of the hydraulic pump is decreased from a high state to a low state, when a real speed of the engine is less than a preset value and the target speed, until the real speed is increased to be equal to or greater than a value less than the preset value and the target speed, the control unit uses an engine torque assist action of the generator motor to control the engine speed to be equal to the target speed.