Working machine

• US 8,459,008 B2
• Filed: 06/23/2010
• Issued: 06/11/2013
• Est. Priority Date: 07/02/2009
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Kamiya, Shohei, Sato, Kensuke, Tsukada, Hidenobu, Shibamori, Kazuhiro
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): Singh, Dapinder
• Application Number:
  US12/821,550
• Publication Number:
  US 20110000197A1
• Time in Patent Office: 1,084 Days
• Field of Search: 602/85, 602/95, 602/97, 603/01
• US Class Current: 60/285
• CPC Class Codes: E02F 9/00 Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00 laying-out or take-up devices for trailing electric cables B66C
• CPC Class Codes: E02F 9/0866 Engine compartment, e.g. heat exchangers, exhaust filters, cooling devices, silencers, mufflers, position of hydraulic pumps in the engine compartment
• CPC Class Codes: E02F 9/2066 of the type combustion engines
• CPC Class Codes: E02F 9/2228 including an electronic controller
• CPC Class Codes: E02F 9/2235 including an electronic controller
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2430/06 by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 2430/085 at least a part of the injection taking place during expansion or exhaust stroke
• CPC Class Codes: F01N 2560/06 the means being a temperature sensor
• CPC Class Codes: F01N 2560/08 the means being a pressure sensor
• CPC Class Codes: F01N 2590/08 for heavy duty applications, e.g. trucks, buses, tractors, locomotives
• CPC Class Codes: F01N 2900/1406 Exhaust gas pressure
• CPC Class Codes: F01N 2900/1602 Temperature of exhaust gas apparatus
• CPC Class Codes: F01N 3/103 Oxidation catalysts for HC and CO only
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F02D 2041/026 using an external load, e.g. by increasing generator load or by changing the gear ratio
• CPC Class Codes: F02D 41/0255 to accelerate the warming-up of the exhaust gas treating apparatus at engine start
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

An exhaust gas treatment filter removes particulate matter from exhaust gas of a diesel engine. The particulate matter which accumulates on the filter is removed by a manual regeneration system that can simply be controlled.

After a manual regeneration switch 22 is shifted to an ON-position, a load control section 66 keeps at least one of the revolution speed N of an engine 1, the displacement volume q and discharge pressure P of a hydraulic pressure pump 11 at a corresponding first target value (N1, q1, or P1) or second target value (N2, q2, or P2) depending on a temperature of the cooling water in relation to a flame-out prevention temperature T1. A regeneration control section 67 starts the compulsory regeneration after the manual regeneration switch has been shifted to the ON-position and when the cooling water temperature is equal to or higher than T1.

Claims

1. A working machine comprising:

a diesel engine;

a variable displacement hydraulic pump driven by the diesel engine;

exhaust gas treatment equipment having a filter capturing particulate matter in the exhaust gas of the engine;

a cooling water temperature sensor that detects cooling water temperature of the engine; and

a controller configured to increase at least one of revolution speed N of the engine, displacement volume q and discharge pressure P of the hydraulic pump from a state at low-idle time to increase an engine load, to compulsorily regenerate the filter by allowing fuel to stay in the exhaust gas of the engine to compulsorily elevate exhaust temperature and to instruct the controller to start the compulsory regeneration; and

wherein the controller is further configured to keep, after the instruction is given to start the compulsory regeneration and when the cooling water temperature is lower than flame-out prevention temperature T1 set to prevent occurrence of flame-out during the compulsory regeneration, at least one of the revolution speed N of the engine, the displacement volume q and discharge pressure P of the hydraulic pressure pump at a corresponding first target value (N1, q1, or P1) set to allow the cooling water temperature to reach the flame-out prevention temperature T1 or higher,

wherein the controller is further configured to keep, after the instruction is given to start the compulsory regeneration and when the cooling water temperature is equal to or higher than the flame-out prevention temperature T1, at least one of the revolution speed N of the engine, the displacement volume q and discharge pressure P of the hydraulic pressure pump at a corresponding second target value (N2, q2, or P2) that is a target value set to keep exhaust temperature at which the compulsory regeneration is possible and that is set lower than the first target value, and

wherein the controller is further configured to start the compulsory regeneration after the instruction is given to start the compulsory regeneration and when the cooling water temperature is equal to or higher than the flame-out prevention temperature T1.

2. The working machine according to claim 1, wherein the controller is further configured to determine

whether or not the compulsory regeneration of the filter is completed, and

if the controller determines that the compulsory regeneration is completed after the compulsory regeneration has been started, then the controller is configured to finish the compulsory regeneration.

3. The working machine according to claim 2, further comprising:

an exhaust temperature sensor that detects exhaust temperature of the engine immediately before exhaust gas is introduced into the filter, and

wherein the controller is configured to measure the time during which exhaust temperature detected by the exhaust temperature sensor is kept in a compulsory regenerable range and further to determine that the compulsory regeneration is completed when the measured time reaches regeneration completion time set to determine regeneration completion timing of the filter.

4. The working machine according to claim 1, further comprising:

an outside air temperature sensor that detects outside air temperature, and

wherein when the outside air temperature is equal to or higher than a preset temperature set to suppress fuel consumption along with a load rise, and when the cooling water temperature is lower than the flame-out prevention temperature T1 after the instruction has been given by the controller to start the compulsory regeneration, the controller is further configured to keep at least one of the revolution speed N of the engine, the displacement volume q and discharge pressure P of the hydraulic pressure pump at a corresponding third target value (N3, q3, or P3) that is a target value set to allow the cooling water temperature to reach the flame-out prevention temperature T1 or higher and that is set lower than the first target value and equal to or higher than the second target value.

5. The working machine according to claim 1, further comprising:

a lock device that makes it impossible for an operator to operate the working machine when the lock device is at a lock position, and

wherein the controller is further configured to exercise load control and compulsory regeneration, respectively, when the lock device is at the lock position.

6. The working machine according to claim 2, further comprising:

an outside air temperature sensor that detects outside air temperature, and

wherein when the outside air temperature is equal to or higher than a preset temperature set to suppress fuel consumption along with a load rise, and when the cooling water temperature is lower than the flame-out prevention temperature T1 after the instruction has been given by the controller to start the compulsory regeneration, the the controller is further configured to keep at least one of the revolution speed N of the engine, the displacement volume q and discharge pressure P of the hydraulic pressure pump at a corresponding third target value (N3, q3, or P3) that is a target value set to allow the cooling water temperature to reach the flame-out prevention temperature T1 or higher and that is set lower than the first target value and equal to or higher than the second target value.

7. The working machine according to claim 3, further comprising:

an outside air temperature sensor that detects outside air temperature, and

wherein when the outside air temperature is equal to or higher than a preset temperature set to suppress fuel consumption along with a load rise, and when the cooling water temperature is lower than the flame-out prevention temperature T1 after the instruction has been given by the controller to start the compulsory regeneration, the the controller is further configured to keep at least one of the revolution speed N of the engine, the displacement volume q and discharge pressure P of the hydraulic pressure pump at a corresponding third target value (N3, q3, or P3) that is a target value set to allow the cooling water temperature to reach the flame-out prevention temperature T1 or higher and that is set lower than the first target value and equal to or higher than the second target value.

8. The working machine according to claim 2, further comprising:

a lock device that makes it impossible for an operator to operate the working machine when the lock device is in a lock position, and

wherein the the controller is further configured to exercise load control and compulsory regeneration, respectively, when the lock device is in the lock position.

9. The working machine according to claim 3, further comprising:

a lock device that makes it impossible for an operator to operate the working machine when the lock device is in a lock position, and

wherein the controller is further configured to exercise load control and compulsory regeneration, respectively, when the lock device is in the lock position.

10. The working machine according to claim 4, further comprising:

a lock device that makes it impossible for an operator to operate the working machine when the lock device is in a lock position, and

wherein the controller is further configured to exercise load control and compulsory regeneration, respectively, when the lock device is in the lock position.