# US 2021/0277813 A1 · Construction Machine

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- Number: US 2021/0277813 A1
- Document ID: US20210277813A1
- Status: Published application
- Kind: A1
- Application number: 16/330,611
- Filed: 2018-02-28
- Published: 2021-09-09
- Earliest claimed: 2017-03-01
- Assignees: Hitachi Construction Machinery Tierra Co., Ltd.
- Applicants: Hitachi Construction Machinery Tierra Co., Ltd.
- Inventors: Shuuhei NOGUCHI; Hajime YOSHIDA; Tetsuya NAKABAYASHI
- Web page: https://patentgrep.com/patent/US20210277813A1

## CPC

- F01N 3/021: by means of filters
- F01N 3/0253: {adding fuel to exhaust gases}
- F01N 3/023: using means for regenerating the filters, e.g. by burning trapped particles
- F01N 3/033: in combination with other devices {(with adsorbents or absorbents F01N3/0821)}
- F01N 3/10: by thermal or catalytic conversion of noxious components of exhaust
- F01N 3/18: characterised by methods of operation; Control
- F01N 9/002: {of filter regeneration}
- F01N 13/009: {having two or more separate purifying devices arranged in series}
- F02D 45/00: Electrical control not provided for in groups F02D41/00 - F02D43/00
- F02M 26/15: in relation to engine exhaust purifying apparatus
- F02M 26/45: Sensors specially adapted for EGR systems
- F02M 26/47: the characteristics being temperatures, pressures or flow rates
- F01N 2560/08: the means being a pressure sensor
- F01N 2560/14: having more than one sensor of one kind
- F01N 2590/08: for heavy duty applications, e.g. trucks, buses, tractors, locomotives
- F02M 26/13: Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- Y02T 10/40: Engine management systems
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A filter (30) traps particulate matter in an exhaust gas. A filter inlet side pressure sensor (34) is provided in an inlet side of the filter (30). An EGR valve inlet side pressure sensor (22) is provided in an inlet side of an EGR valve (20). A regeneration controller (38C) determines whether or not the filter inlet side pressure sensor (34) is in failure based upon a difference between a pressure value detected by the filter inlet side pressure sensor (34) and a pressure value detected by the EGR valve inlet side pressure sensor (22). When the filter inlet side pressure sensor (34) is in failure, the regeneration controller (38C) performs control of regeneration treatment using a differential pressure calculated based upon a pressure value detected by the EGR valve inlet side pressure sensor (22) and a pressure value detected by the filter outlet side pressure sensor (35).

## Claims

### Claim 1

A construction machine comprising:
an engine that is mounted on a vehicle body;
an engine controller that performs control of the engine;
an intake manifold that intakes outside air into the engine;
an exhaust manifold that exhausts an exhaust gas from the engine;
an EGR pipe that recirculates a part of the exhaust gas in the exhaust manifold from the exhaust manifold to the intake manifold;
an EGR valve that is provided in the EGR pipe to adjust a flow quantity of the exhaust gas passing through the EGR pipe;
an EGR valve inlet side pressure sensor that is provided in an inlet side of the EGR valve;
an EGR valve outlet side pressure sensor that is provided in an outlet side of the EGR valve;
an EGR controller that calculates a differential pressure between a pressure value detected by the EGR valve inlet side pressure sensor and a pressure value detected by the EGR valve outlet side pressure sensor and performs control of an opening degree of the EGR valve based upon this differential pressure;
an exhaust gas purifying device that is provided in an exhaust side of the engine and has a filter that traps particulate matter in the exhaust gas exhausted from the engine;
a regeneration device that performs regeneration treatment of the filter by burning the particulate matter trapped in the filter of the exhaust gas purifying device,
the regeneration device including:
a filter inlet side pressure sensor that is provided in an inlet side of the filter;
a filter outlet side pressure sensor that is provided in an outlet side of the filter; and
a regeneration controller that calculates a differential pressure between a pressure value detected by the filter inlet side pressure sensor and a pressure value detected by the filter outlet side pressure sensor and performs control of the regeneration treatment of the filter based upon this differential pressure, characterized in that:
the regeneration controller determines whether or not the filter inlet side pressure sensor is in failure based upon a difference between the pressure value detected by the filter inlet side pressure sensor and the pressure value detected by the EGR valve inlet side pressure sensor; and
when it is determined that the filter inlet side pressure sensor is in failure, the regeneration controller performs the control of the regeneration treatment using a differential pressure calculated based upon the pressure value detected by the EGR valve inlet side pressure sensor and the pressure value detected by the filter outlet side pressure sensor.

### Claim 2 (depends on 1)

The construction machine according to claim 1, wherein
the regeneration controller makes a determination on whether or not the filter inlet side pressure sensor is in failure when the engine is driving.

### Claim 3 (depends on 1)

The construction machine according to claim 1, wherein
an atmospheric pressure sensor that detects an atmospheric pressure is connected to the regeneration controller,
the regeneration controller determines whether or not the filter inlet side pressure sensor is in failure based upon a difference between a pressure value detected by the atmospheric pressure sensor and a pressure value detected by the filter inlet side pressure sensor before starting the engine,
even when it is determined that the filter inlet side pressure sensor is not in failure by the determination on the failure before this start, the regeneration controller determines whether or not the filter inlet side pressure sensor is in failure based upon the difference between the pressure value detected by the filter inlet side pressure sensor and the pressure value detected by the EGR valve inlet side pressure sensor.

### Claim 4 (depends on 1)

The construction machine according to claim 1, wherein
when the difference between the pressure value detected by the filter inlet side pressure sensor and the pressure value detected by the EGR valve inlet side pressure sensor is equal to or more than a preset failure determining threshold value, the regeneration controller determines that the filter inlet side pressure sensor is in failure.

### Claim 5 (depends on 1)

The construction machine according to claim 1, wherein
the regeneration controller:
estimates a first estimated trapping quantity of the particulate matter trapped in the filter based upon a differential pressure as a difference at least between a filter inlet side pressure value detected by the filter inlet side pressure sensor and a filter outlet side pressure value detected by the filter outlet side pressure sensor;
estimates a second estimated trapping quantity of the particulate matter trapped in the filter based upon at least a rotational speed of the engine and a fuel injection quantity;
determines whether to perform the regeneration treatment based upon whether or not at least any one between the first estimated trapping quantity and the second estimated trapping quantity is equal to or more than a preset trapping quantity threshold value;
when it is determined that the filter inlet side pressure sensor is in failure, estimates the first estimated trapping quantity using the differential pressure calculated based upon the pressure value detected by the EGR valve inlet side pressure sensor and the pressure value detected by the filter outlet side pressure sensor; and
when it is determined that the filter inlet side pressure sensor is not in failure, estimates the first estimated trapping quantity using a differential pressure calculated based upon a pressure value detected by the filter inlet side pressure sensor and a pressure value detected by the filter outlet side pressure sensor.

### Claim 6 (depends on 1)

The construction machine according to claim 1, wherein
a map showing a relation of a pressure value detected by the filter inlet side pressure sensor and a pressure value detected by the EGR valve inlet side pressure sensor when both of the filter inlet side pressure sensor and the EGR valve inlet side pressure sensor are normal is stored in the regeneration controller; and
when it is determined that the filter inlet side pressure sensor is in failure, the regeneration controller calculates a pressure value to be detected by the filter inlet side pressure sensor from a pressure value detected by the EGR valve inlet side pressure sensor based upon this map, and performs the control of the regeneration treatment using a differential pressure calculated based upon this calculated pressure value and a pressure value detected by the filter outlet side pressure sensor.