Hybrid work machine

• US 9,550,413 B2
• Filed: 07/24/2013
• Issued: 01/24/2017
• Est. Priority Date: 07/24/2013
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Take, Hiroaki
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): RINK, RYAN J
• Application Number:
  US14/650,417
• Publication Number:
  US 20150315766A1
• Time in Patent Office: 1,280 Days
• US Class Current: 1/1
• CPC Class Codes: B60K 6/485 Motor-assist type
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: E02F 9/20 Drives; Control devices gearings in general F16H; controlling in general G05; electric multi-motor drives H02K, H02P
• 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 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 29/04 peculiar to engines driving pumps
• 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: G05B 7/00 Arrangements for obtaining smooth engagement or disengagement of automatic control
• CPC Class Codes: H01F 38/00 Adaptations of transformers or inductances for specific applications or functions
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A hybrid work machine includes: an engine; a generator motor; a storage battery; a motor; a transformer; a target engine speed calculation unit configured to calculate a target engine speed based on at least an engine load and an output state of the generator motor; a generation control unit configured to output a generator requesting minimum engine speed; an engine controlling target engine speed calculation unit configured to calculate and output an engine controlling target engine speed based on the target engine speed and the generator requesting minimum engine speed; an engine control unit configured to control an engine speed based on the engine controlling target engine speed; and an assist control unit configured to set the target engine speed to the generator controlling target engine speed and control engine assist based on the generator controlling target engine speed and the generator motor speed.

Claims

1. A hybrid work machine, comprising:

an engine;

a generator motor connected to a drive shaft of the engine;

a storage battery configured to store power generated by the generator motor and supply power to the generator motor;

a motor configured to be driven by at least one of power generated by the generator motor and power stored in the storage battery;

a transformer disposed between the storage battery and both the generator motor and the motor;

a pump controller configured to calculate a target engine speed based on at least an engine load and an output state of the generator motor, to calculate and output an engine controlling target engine speed based on the target engine speed and a generator requesting minimum engine speed, and to set a generator controlling target engine speed to a value equal to the target engine speed and output the generator controlling target engine speed;

a hybrid controller configured to output the generator requesting minimum engine speed, which is a minimum engine speed to secure generation power of the storage battery, in accordance with a storage state of the storage battery and a generator motor speed, the hybrid controller further configured to control engine assist based on the generator controlling target engine speed and the generator motor speed; and

an engine controller configured to control an engine speed based on the engine controlling target engine speed.

5. The hybrid work machine according to claim 1, wherein

the pump controller calculates, as a target engine speed, an engine speed at an intersection point between a matching route and a target engine output setting line that specifies target engine output in a torque chart relative to an engine speed, the matching route preliminarily setting a target matching point passing an area on the torque chart having good fuel efficiency when the engine speed becomes high due to increase of engine output.

6. The hybrid work machine according to claim 1, wherein

a voltage conversion ratio of the transformer is same as a ratio of number of turns between number of coil turns on a side to be an input side and number of coil turns on a side to be an output side.

8. The hybrid work machine according to claim 5, wherein

a voltage conversion ratio of the transformer is same as a ratio of number of turns between number of coil turns on a side to be an input side and number of coil turns on a side to be an output side.

2. A hybrid work machine, comprising:

an engine;

a generator motor connected to a drive shaft of the engine;

a storage battery configured to store power generated by the generator motor and supply power to the generator motor;

a motor configured to be driven by at least one of power generated by the generator motor and power stored in the storage battery;

a transformer disposed between the storage battery and both the generator motor and the motor;

a pump controller configured to calculate a target engine speed based on at least an engine load and an output state of the generator motor, and to calculate and output an engine controlling target engine speed based on the target engine speed and the generator requesting minimum engine speed, the pump controller including an output processing unit which is configured to output a generator controlling target engine speed;

a hybrid controller configured to output a generator requesting minimum engine speed, which is a minimum engine speed to secure generation power of the storage battery, in accordance with a storage state of the storage battery and a generator motor speed, the hybrid controller further configured to control engine assist based on the generator controlling target engine speed, and a generator motor speed; and

an engine controller configured to control an engine speed based on the engine controlling target engine speed,

wherein the output processing unit is configured to output the target engine speed as the generator controlling target engine speed at a time the generator requesting minimum engine speed exceeds the target engine speed;

voltage of the storage battery exceeds predetermined voltage;

a transformer temperature exceeds a predetermined transformer temperature; and

a storage battery temperature exceeds a predetermined storage battery temperature, and

to output a higher engine speed out of the generator requesting minimum engine speed and the target engine speed as the generator controlling target engine speed at a time;

the voltage of the storage battery does not exceed the predetermined voltage;

the transformer temperature does not exceed the predetermined transformer temperature;

or the storage battery temperature does not exceed the predetermined storage battery temperature.

3. The hybrid work machine according to claim 2, wherein

the pump controller calculates, as a target engine speed, an engine speed at an intersection point between a matching route and a target engine output setting line that specifies target engine output in a torque chart relative to an engine speed, the matching route preliminarily setting a target matching point passing an area on the torque chart having good fuel efficiency when the engine speed becomes high due to increase of engine output.

4. The hybrid work machine according to claim 2, wherein

a voltage conversion ratio of the transformer is same as a ratio of number of turns between number of coil turns on a side to be an input side and number of coil turns on a side to be an output side.

7. The hybrid work machine according to claim 3, wherein

a voltage conversion ratio of the transformer is same as a ratio of number of turns between number of coil turns on a side to be an input side and number of coil turns on a side to be an output side.