JP6008779B2 - Exhaust gas purification system - Google Patents

Description

  The present invention relates to an exhaust gas purification system for an engine mounted on a work machine such as a construction machine, an agricultural machine, and an engine generator.

  Conventionally, as an exhaust gas countermeasure for diesel engines (hereinafter simply referred to as engines), an exhaust filter (diesel particulate filter) is provided in the exhaust path of the engine to collect particulate matter (PM) and the like in the exhaust gas. Thus, techniques for suppressing atmospheric emission are well known (see, for example, Patent Documents 1 and 2). If the PM collected by the exhaust filter exceeds a specified amount, the flow resistance in the exhaust filter increases and the engine output decreases, so the PM accumulated on the exhaust filter is removed by the temperature rise of the exhaust gas, and the exhaust filter Recovering (regenerating) the ability to collect PM is also performed. If the exhaust filter is not sufficiently regenerated even if the temperature of the exhaust gas is raised, regeneration of the exhaust filter can be promoted by supplying unburned fuel into the exhaust filter and burning PM. Such a reset reproduction technique is also known.

JP 2000-145430 A Japanese Patent Laid-Open No. 2003-27922

  However, even if reset regeneration for supplying unburned fuel into the exhaust filter is performed, PM may be excessively accumulated in the exhaust filter if an operation state in which a sufficient temperature raising action cannot be obtained continues. When the exhaust filter is regenerated in such a situation, the exhaust filter is cracked or melted due to abrupt combustion (runaway combustion) of the accumulated PM.

  This invention makes it a technical subject to provide the exhaust-gas purification system which examined and improved the above present condition.

The present invention includes a common rail engine and an exhaust gas purification device disposed in an exhaust path of the engine, and an exhaust capable of performing a plurality of regeneration controls for burning and removing particulate matter accumulated in the exhaust gas purification device. In the gas purification system, the plurality of regeneration controls include a reset regeneration control for increasing the exhaust gas temperature by using post injection, and a non-work regeneration control for increasing the exhaust gas temperature by combining post injection and a predetermined high speed rotation speed. And at least a recovery regeneration control that can be executed when the non-work regeneration control fails. In the non-work regeneration control and the recovery regeneration control, the engine is driven exclusively for combustion removal of the particulate matter. , together with the process proceeds to the recovery playback control from the reset playback control via the non-working reproduction control, the reset It is set to the cumulative time from running the live control or the non-working reproduction control is transferred to the non-working reproduction control without going through the reset regeneration control if it exceeds a predetermined time, the reset regeneration When shifting from the control to the non-work regeneration control, the process proceeds to the non -work regeneration control without going through the reset regeneration control via the non-work standby mode waiting for establishment of a preset non-work transition condition. When waiting for the preset non-work transition condition to be established , the transition to the recovery regeneration control from the non-work regeneration control is performed in a standby state for waiting for the preset recovery transition condition to be established. When each transition condition is not satisfied via the mode , the system waits in the standby mode or the arrow mode .

In the exhaust gas purification system, in the non-work regeneration control, the engine output is limited to a non-working maximum output lower than a maximum output.

In the exhaust gas purification system, in the recovery regeneration control, the output of the engine is limited to a maximum output during recovery that is lower than the maximum output during non-operation.

According to the present invention, a common rail engine and an exhaust gas purification device disposed in the exhaust path of the engine are provided, and a plurality of regeneration controls for burning and removing particulate matter accumulated in the exhaust gas purification device can be executed. In the exhaust gas purification system, the plurality of regeneration controls include a reset regeneration control that increases the exhaust gas temperature by using post injection, and a non-work regeneration that increases the exhaust gas temperature by combining post injection and a predetermined high speed rotation speed. Control and recovery regeneration control that can be executed when the non-work regeneration control fails, and the non-work regeneration control and the recovery regeneration control drive the engine exclusively for the combustion removal of the particulate matter. Therefore, the engine does not normally operate in the non-work regeneration control and the recovery regeneration control. That is, the non-work regeneration control and the recovery regeneration control exist as modes for avoiding a crisis such as prevention of damage (melting damage) of the exhaust gas purification device and prevention of excessive emission.

  In addition, when setting the transition from the reset regeneration control to the recovery regeneration control through the non-work regeneration control, and when shifting from the reset regeneration control to the non-work regeneration control, a preset non-work transition is performed. When transitioning from the non-work regeneration control to the recovery regeneration control via the non-work standby mode that waits for the establishment of the condition, the recovery standby mode that waits for the establishment of a preset recovery transition condition When the transition condition is not satisfied, the standby is performed in each standby mode. Therefore, once the transition is made to each standby mode, the transition is made only to the non-work regeneration control or the recovery regeneration control. For this reason, regeneration control that causes runaway combustion is not performed, occurrence of runaway combustion can be prevented, and crisis avoidance such as prevention of breakage (melting damage) of the exhaust gas purification device and prevention of excessive emission is ensured. Yes.

According to the present invention, in the non-work regeneration control, the engine output is limited to a non-working maximum output lower than a maximum output, and in the recovery regeneration control, the engine output is set to be lower than the non-work maximum output. Since the maximum output at the time of recovery is limited, when the non-work regeneration control or the recovery regeneration control is executed, an excessive temperature rise and pressure rise of the exhaust gas can be prevented, and the exhaust gas purifying device and the like by the temperature rise can be prevented. It is possible to suppress the deterioration of the exhaust system parts and the occurrence of exhaust gas leakage from the joint of the exhaust system parts due to the pressure increase.

It is the perspective view which looked at the engine from diagonally forward. It is a front view of an engine. It is a rear view of an engine. It is a top view of an engine. It is a right view of an engine. It is a left view of an engine. It is the external appearance perspective view which looked at the exhaust filter from the purification inlet pipe side. It is the external appearance perspective view which looked at the exhaust filter from the purification outlet pipe side. It is a section explanatory view of an exhaust filter. It is fuel system explanatory drawing of an engine. It is a figure explaining the injection timing of fuel. It is explanatory drawing of an instrument panel. It is explanatory drawing of an output characteristic map. It is a flowchart of assist reproduction | regeneration control and reset reproduction | regeneration control. It is a flowchart of non-work reproduction control. It is a flowchart of recovery reproduction | regeneration control. It is a flowchart of non-work reproduction | regeneration control in arrow mode. 10 is a flowchart of assist regeneration control and reset regeneration control in another example in which the regeneration switch is omitted. 10 is a flowchart of non-work regeneration control in another example in which the regeneration switch is omitted. It is a flowchart of the recovery reproduction | regeneration control in another example which abbreviate | omitted the reproduction | regeneration switch. It is a flowchart of non-work reproduction | regeneration control in the arrow mode in another example which abbreviate | omitted the reproduction | regeneration switch.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1). Overview of Engine First, an overview of a common rail engine 201 will be described with reference to FIGS. In the following description, both sides parallel to the crank axis (the sides on both sides of the crank axis) are front and rear, the cooling fan 209 arrangement side is the right side, the flywheel housing 210 arrangement side is the left side, and the exhaust manifold 7 is arranged. The side is referred to as the front side, and the side on which the intake manifold 6 is disposed is referred to as the rear side, and these are used as a reference for the positional relationship between the four sides and the top and bottom of the engine 201 for convenience.

  As shown in FIGS. 1 to 6, an engine 201 as a prime mover mounted on a work machine such as an agricultural machine or a construction / civil engineering machine includes an exhaust filter 202 (diesel particulate filter) that is a continuously regenerative exhaust gas purification device. ). The exhaust filter 202 removes particulate matter (PM) in the exhaust gas exhausted from the engine 201 and reduces carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas.

  The engine 201 includes a cylinder block 204 that incorporates a crankshaft 203 that is an engine output shaft and a piston (not shown). A cylinder head 205 is mounted on the cylinder block 204. An intake manifold 206 is disposed on the rear side surface of the cylinder head 205, and an exhaust manifold 207 is disposed on the front side surface of the cylinder head 205. The upper surface side of the cylinder head 205 is covered with a head cover 208. The left and right ends of the crankshaft 203 protrude from the left and right sides of the cylinder block 204. A cooling fan 209 is provided on the right side of the engine 201. Rotational power is transmitted from the left end side of the crankshaft 203 to the cooling fan 209 via the cooling fan V-belt 222.

  A flywheel housing 210 is provided on the rear side of the engine 201. A flywheel 211 is accommodated in the flywheel housing 210 while being supported on the rear end side of the crankshaft 203. The rotational power of the engine 201 is transmitted from the crankshaft 203 to the operating part of the work machine via the flywheel 211. An oil pan 212 that stores lubricating oil is disposed on the lower surface of the cylinder block 204. Lubricating oil in the oil pan 212 is supplied to each lubricating portion of the engine 201 through an oil filter 213 and the like disposed on the rear side of the cylinder block 204, and then returns to the oil pan 212.

  A fuel supply pump 214 is provided above the oil filter 213 on the rear side of the cylinder block 204 (below the intake manifold 206). The engine 201 includes an injector 215 for four cylinders having an electromagnetic opening / closing control type fuel injection valve 219 (see FIG. 10). A common rail device 220 that injects fuel into each cylinder of the engine 201 in a single combustion cycle is provided below the intake manifold 206 on the rear side of the cylinder block 204. Each injector 215 is connected to a fuel tank 218 mounted on the work machine via a fuel supply pump 214, a common rail device 220, and a fuel filter 217. The fuel in the fuel tank 218 is pumped from the fuel supply pump 214 to the common rail device 220 via the fuel filter 217. By controlling the fuel injection valve 219 of each injector 215 to open and close, the high-pressure fuel stored in the common rail device 220 is injected from each injector 215 to each cylinder of the engine 201.

  On the left side of the cylinder block 204, a cooling water pump 221 for lubricating lubricating water is disposed coaxially with the fan shaft of the cooling fan 029. The cooling water pump 221 is driven together with the cooling fan 209 via the cooling fan V-belt 222 by the rotational power of the crankshaft 203. Cooling water in a radiator (not shown) mounted on the work machine is supplied to the cylinder block 204 and the cylinder head 205 by driving the cooling water pump 221 to cool the engine 201. Cooling water that has contributed to cooling of the engine 201 is returned to the radiator. An alternator 223 is arranged on the left side of the cooling water pump 221.

  Engine leg mounting portions 224 are provided on the front and rear sides of the cylinder block 204, respectively. Each engine leg mounting portion 224 is bolted to an engine leg body (not shown) having anti-vibration rubber. The engine 201 is supported in an anti-vibration manner by a work machine (specifically, an engine mounting chassis) through each engine leg.

  As shown in FIGS. 2 and 4, the inlet portion of the intake manifold 206 is connected to an air cleaner (not shown) via an EGR device 226 (exhaust gas recirculation device). The fresh air (external air) sucked into the air cleaner is dust-removed and purified by the air cleaner, and then sent to the intake manifold 206 via the EGR device 226 and supplied to each cylinder of the engine 201.

  The EGR device 226 mixes a part of the exhaust gas of the engine 201 (EGR gas from the exhaust manifold 207) and fresh air (external air from the air cleaner) and supplies the mixed air to the intake manifold 206, and the air cleaner An intake throttle member 228 for communicating the EGR main body case 227, a recirculation exhaust gas pipe 230 connected to the exhaust manifold 207 via an EGR cooler 229, and an EGR valve member for communicating the EGR main body case 227 with the recirculation exhaust gas pipe 230 231.

  An intake throttle member 228 is connected to the intake manifold 206 via an EGR main body case 227. The intake throttle member 228 is bolted to one end of the EGR main body case 227 in the longitudinal direction. The left and right inwardly open end portions of the EGR main body case 227 are bolted to the inlet portion of the intake manifold 206. The outlet side of the recirculation exhaust gas pipe 230 is connected to the EGR main body case 227 via an EGR valve member 231. The inlet side of the recirculated exhaust gas pipe 230 is connected to the lower surface side of the exhaust manifold 207 via an EGR cooler 229. By adjusting the opening degree of the EGR valve member 231, the supply amount of EGR gas to the EGR main body case 227 is adjusted.

  In the above configuration, fresh air (external air) is supplied from the air cleaner into the EGR main body case 227 via the intake throttle member 228, while EGR is supplied from the exhaust manifold 207 into the EGR main body case 227 via the EGR valve member 231. Gas (a part of the exhaust gas discharged from the exhaust manifold 207) is supplied. After the fresh air from the air cleaner and the EGR gas from the exhaust manifold 207 are mixed in the EGR main body case 227, the mixed gas in the EGR main body case 227 is supplied to the intake manifold 206. In this way, a part of the exhaust gas discharged from the exhaust manifold 207 is recirculated to the engine 201 via the intake manifold 206, whereby the maximum combustion temperature during high-load operation is lowered, and NOx (nitrogen oxidation from the engine 201 is performed. Waste) is reduced.

  As shown in FIGS. 1 to 5, a turbocharger 232 is disposed on the right side of the cylinder head 205 and above the exhaust manifold 207. The turbocharger 232 includes a turbine case 233 with a built-in turbine wheel (not shown) and a compressor case 234 with a blower foil (not shown). The exhaust inlet side of the turbine case 233 is connected to the outlet portion of the exhaust manifold 207. The exhaust outlet side of the turbine case 233 is connected to a tail pipe (not shown) via an exhaust filter 202. Exhaust gas discharged from each cylinder of the engine 201 to the exhaust manifold 207 is discharged from the tail pipe to the outside through the turbine case 233 of the turbocharger 232, the exhaust filter 202, and the like.

  An intake inlet side of the compressor case 234 is connected to an air cleaner via an intake pipe 235. An intake outlet side of the compressor case 234 is connected to an intake throttle member 228 via a supercharging pipe 236. The fresh air removed by the air cleaner is sent from the compressor case 234 to the intake manifold 206 via the intake throttle member 228 and the EGR main body case 227 and supplied to each cylinder of the engine 201. The intake pipe 235 is connected to a breather chamber in the head cover 208 via a blow-by gas return pipe 237. The blow-by gas from which the lubricating oil is separated and removed in the breather chamber is returned to the intake pipe 235 through the blow-by gas return pipe 237, is returned to the intake manifold 206, and is supplied again to each cylinder of the engine 201.

(2). Structure of Exhaust Filter Next, the structure of the exhaust filter 202 will be described with reference to FIGS. The exhaust filter 202 includes a purification casing 240 made of a heat-resistant metal material having a purification inlet pipe 241 and a purification outlet pipe 242. Inside the purification casing 240, a diesel oxidation catalyst 243 such as platinum that generates nitrogen dioxide (NO2), and a soot filter having a honeycomb structure that continuously oxidizes and removes the collected particulate matter (PM) at a relatively low temperature. 244 are accommodated in series in the exhaust gas movement direction (see the arrow direction in FIG. 9). A purification inlet pipe 241 and a purification outlet pipe 242 are provided separately on both sides in the longitudinal direction (one end side and the other end side) of the purification casing 240. The purification inlet pipe 241 is connected to the exhaust outlet side of the turbine case 233. The purification outlet pipe 242 is connected to a tail pipe (not shown).

  In the above configuration, the exhaust gas of the engine 201 flows into the purification casing 240 from the exhaust outlet side of the turbine case 233 via the purification inlet pipe 241 and passes through the diesel oxidation catalyst 243 and the soot filter 244 in this order for purification. It is processed. Particulate matter in the exhaust gas is collected without passing through the porous partition wall between the cells in the soot filter 244. Thereafter, exhaust gas that has passed through the diesel oxidation catalyst 243 and the soot filter 244 is discharged toward the tail pipe.

  When the exhaust gas passes through the diesel oxidation catalyst 243 and the soot filter 244, if the exhaust gas temperature exceeds a renewable temperature (for example, about 300 ° C.), the oxidation of the exhaust gas is caused by the action of the diesel oxidation catalyst 243. Nitrogen (NO) is oxidized to unstable nitrogen dioxide (NO2). Then, oxygen (O) released when nitrogen dioxide returns to nitric oxide oxidizes and removes the particulate matter deposited on the soot filter 244, so that the particulate matter collecting ability of the soot filter 244 is restored (soot). The filter 244 is self-regenerating). In the embodiment, the other end side in the longitudinal direction of the purification casing 240 is configured in the silencer 245, and the purification outlet pipe 242 is provided in the silencer 245.

  An inlet side cover body 254 is welded and fixed to one end side (end portion on the upstream side of the exhaust) of the inlet side case 247. One end side of the entrance side case 247 is closed with an entrance side lid 254. A purification inlet pipe 241 is fixed by welding to the outer peripheral side of the inlet side case 247. The purification inlet pipe 241 communicates with the inlet side case 247 via an exhaust gas inlet 255 formed in the inlet side case 247. The inlet side case 246 and the outlet side case 247 are detachably fastened by a plurality of thick plate-like flange bodies 271 and a plurality of bolts 272.

  The silencer 45 located on the other end side in the longitudinal direction of the purification casing 240 includes a silencer case 251. One end side (end portion on the exhaust upstream side) of the muffler case 251 is connected to the outlet case 247 in communication. An outlet side cover body 265 is welded and fixed to the other end side (end portion on the exhaust downstream side) of the silencer case 251. The silencing case 251 is provided with a purification outlet pipe 242 having a number of exhaust communication holes. The protruding end side of the purification outlet pipe 42 is connected to, for example, a tail pipe or an existing silencer member. The outlet side case 247 and the muffling case 251 are detachably fastened by a plurality of sets of thick plate-like flange bodies 273 and a plurality of bolts 274.

  A connecting leg 277 for supporting the purification casing 240 on the engine 201 is detachably attached to at least one of the thick plate-like flange bodies 273. A fixed leg 279 for supporting the purification casing 240 on the engine 201 is fixed to the outer peripheral side of the purification casing 240 (in the embodiment, the inlet side case 247) by welding. The connecting leg 277 and the fixed leg 279 are bolted to a casing attachment portion 280 formed on the upper surface side of the flywheel housing 210. That is, the exhaust filter 202 is stably connected and supported on the flywheel housing 210 that is a highly rigid member by the connecting leg 277 and the fixed leg 279.

  As shown in FIGS. 7 and 8, on the outer peripheral side of the purification casing 240, a differential pressure sensor 281 that detects the exhaust gas pressure in the purification casing 240, and a DPF temperature that similarly detects the exhaust gas temperature in the purification casing 240. And an electrical wiring connector 294 of the sensor 282. The differential pressure sensor 281 detects the exhaust gas differential pressure between the exhaust upstream side and the exhaust downstream side across the soot filter 244, and the PM accumulation amount of the soot filter 44 is converted using the differential pressure, The clogged state in the exhaust filter 202 is estimated. Regeneration control of the soot filter 244 (exhaust filter 202) is performed by controlling the operation of the intake throttle member 228 and the common rail 216 based on the conversion result of the PM accumulation amount.

  A sensor bracket 283 that supports the electrical wiring connector 294 of the differential pressure sensor 281 and the DPF temperature sensor 282 is detachably attached to at least one of the thick plate-like flange bodies 273. An electrical wiring connector 294 for the differential pressure sensor 281 and the DPF temperature sensor 282 is arranged in parallel on the sensor bracket 283. One end side of upstream and downstream sensor pipes 288 and 289 is connected to the differential pressure sensor 281, respectively. The purification casing 240 is provided with a pair of pressure boss bodies 292 so as to sandwich the soot filter 244. Corresponding sensor pipes 288 and 289 are connected to the respective pressure boss bodies 292. There are a plurality of electrical wiring connectors 294 of the exhaust gas temperature sensor 282, and sensor piping 295 is extended from each electrical wiring connector. The corresponding sensor pipes 295 are connected to the temperature boss bodies 298 provided in the purification casing 240.

(3). Outline of Common Rail Device Next, an outline of the common rail device 220 that is a fuel injection device will be described with reference to FIGS. 10 and 11. A fuel tank 218 is connected to each injector 215 for four cylinders in the engine 201 via a common rail device 220 and a fuel supply pump 214. As described above, each injector 215 includes an electromagnetic switching control type fuel injection valve 219. The common rail device 220 includes a cylindrical common rail 216 (pressure accumulation chamber). The suction side of the fuel supply pump 214 is connected to a fuel tank 218 via a fuel filter 217 and a low pressure pipe 261. The fuel in the fuel tank 218 is sucked into the fuel supply pump 216 via the fuel filter 217 and the low pressure pipe 261. A common rail 216 is connected to the discharge side of the fuel supply pump 216 via a high-pressure pipe 262. Four rails of injectors 215 are connected to the common rail 216 via four fuel injection pipes 263.

  A fuel supply pump 214 is connected to the fuel tank 218 via a fuel return pipe 264. One end of the common rail return pipe 267 is connected to the end of the common rail 216 in the longitudinal direction via a return pipe connector 266 that limits the fuel pressure in the common rail 216. The other end side of the common rail return pipe 267 is connected to the fuel tank 218 via the fuel return pipe 264 (joins the fuel return pipe 264). The surplus fuel in the fuel supply pump 214 and the surplus fuel in the common rail 216 are recovered in the fuel tank 218 via the fuel return pipe 264 and the common rail return pipe 267.

  In the above configuration, the fuel in the fuel tank 218 is pumped to the common rail 216 by the fuel supply pump 214 and stored in the common rail 216 as high-pressure fuel. By controlling the opening and closing (electronic control) of each fuel injection valve 219, the high pressure fuel in the common rail 216 is controlled with high accuracy in injection pressure, injection timing, and injection period (injection amount). 115 is injected into each cylinder of engine 201. Therefore, nitrogen oxide (NOx) discharged from the engine 201 can be reduced, and noise vibration of the engine 201 can be reduced.

  As shown in FIG. 11, the common rail device 220 is configured to execute the main injection A near the top dead center (TDC). In addition to the main injection A, the common rail device 220 performs a small amount of pilot injection B for the purpose of reducing NOx and noise at a crank angle θ1 of about 60 ° before the top dead center, Pre-injection C is executed for the purpose of noise reduction immediately before the crank angle θ2, and particulate matter (hereinafter referred to as PM) is reduced and exhaust gas is emitted at the crank angles θ3 and θ4 after top dead center. The after-injection D and the post-injection E are executed for the purpose of promoting purification.

  The pilot injection B is injected at a timing that is greatly advanced with respect to the main injection A, thereby promoting the mixing of fuel and air. The pre-injection C is performed prior to the main injection A to shorten the ignition timing delay in the main injection A. After-injection D is performed with a slight delay with respect to main injection A, thereby activating diffusion combustion and raising the temperature of exhaust gas from engine 201 (reburning PM). The post-injection E is supplied to the exhaust filter 202 as unburned fuel without contributing to the actual combustion process by being injected at a timing that is largely retarded with respect to the main injection A. The unburned fuel supplied to the exhaust filter 202 reacts on the diesel oxidation catalyst 243, and the exhaust gas temperature in the exhaust filter 202 rises due to the reaction heat. Here, the level of the peaks in the graph in FIG. 11 roughly represents the difference in the fuel injection amount at each of the injection stages A to E.

(4). Engine Control Related Structure Next, a control related structure of the engine 201 will be described with reference to FIGS. As shown in FIG. 10, the ECU 201 includes an ECU 311 that operates a fuel injection valve 219 for each cylinder in the engine 201. Although details are omitted, the ECU 311 includes a CPU that executes various arithmetic processes and controls, a ROM that stores various data fixedly in advance, an EEPROM that stores rewritable control programs and various data, control programs, and various types of data. It has a RAM for temporarily storing data, a timer for time measurement, an input / output interface, and the like, and is arranged in the engine 201 or in the vicinity thereof.

  The ECU 311 is connected to the battery 332 via a key switch 331 for applying power. The key switch 331 is a rotary switch that can be rotated to three terminal positions including a cutting position, an entering position, and a starter position by a predetermined key inserted into the keyhole. The key switch 331 is disposed on the instrument panel 340 provided on the work machine to be mounted with the engine 201 (see FIG. 12). The input position (terminal) of the key switch 331 is connected to the input side of the ECU 311.

  At least the rail pressure sensor 312 that detects the fuel pressure in the common rail 216, the electromagnetic clutch 313 that rotates or stops the fuel pump 214, and the rotational speed of the engine 201 (camshaft position of the crankshaft 203) are detected on the input side of the ECU 311. An engine rotation sensor 314 that detects the number of fuel injections of the injector 215 (the number of times during the fuel injection period of one stroke) and a throttle position sensor 316 that detects the operating position of an accelerator operating tool (not shown). , An intake air temperature sensor 317 for detecting the intake air temperature in the intake passage, an exhaust gas temperature sensor 318 for detecting the exhaust gas temperature in the exhaust passage, a coolant temperature sensor 319 for detecting the coolant temperature of the engine 201, and the fuel temperature in the common rail 216 The fuel temperature sensor 320 detects EGR gas EGR temperature sensor 321 for detecting the degree of pressure, differential pressure sensor 281 for detecting the differential pressure of exhaust gas before and after the soot filter 244 in the exhaust filter 202 (upstream / downstream), and DPF temperature sensor for detecting the exhaust gas temperature in the exhaust filter 202 282, a regeneration switch 322 as a regeneration approval member permitting the exhaust filter 202 regeneration operation, a regeneration prohibition switch 323 as a regeneration prohibiting member prohibiting the exhaust filter 202 regeneration operation, and non-work regeneration control in a locked state (details will be described later) An interlock switch 324 that prohibits the execution of each reproduction control thereafter is connected.

  At least the electromagnetic solenoids of the fuel injection valves 219 for the four cylinders are connected to the output side of the ECU 311. That is, the high-pressure fuel stored in the common rail 216 is injected from the fuel injection valve 219 in a plurality of times during one stroke while controlling the fuel injection pressure, the injection timing, the injection period, and the like, so that nitrogen oxide (NOx ), And complete combustion with reduced generation of soot, carbon dioxide (CO2), etc. is performed to improve fuel efficiency.

  Also, on the output side of the ECU 311, an intake throttle member 228 that adjusts the intake pressure (intake amount) of the engine 201, an EGR valve member 231 that adjusts the supply amount of EGR gas to the intake manifold 206, and an abnormality in the engine 201 are reported. The engine alarm lamp 325 that performs, the exhaust temperature alarm lamp 326 that informs that the exhaust gas is high temperature, the regeneration request lamp 327 that prompts the execution of regeneration control after the non-work regeneration control, and the exhaust filter 202 blinks in association with the regeneration operation. The regeneration lamp 328, the regeneration prohibition lamp 329 that is activated by the prohibition operation of the regeneration prohibition switch 323, and the alarm buzzer 330 that sounds in connection with the exhaust filter 202 regeneration operation and the like are connected. Data relating to blinking of the various lamps 325 to 329 and sounding of the alarm buzzer 330 is stored in advance in the EEPROM of the ECU 311. As shown in FIG. 12, the regeneration switch 322, the regeneration prohibition switch 323, and various lamps 325 to 329 are arranged on the instrument panel 340 in the work machine on which the engine 201 is mounted. The interlock switch 324 is disposed at or near the instrument panel 340.

  As shown in FIG. 12, the regeneration switch 322 and the regeneration prohibition switch 323 are configured as a rocker switch 333 (seesaw switch) that can be rotated around a support shaft located at the center. One of the rocker switches 333 sandwiching the spindle is a regeneration switch 322 and the other is a regeneration prohibiting switch 323.

  The regeneration switch 322 is of a momentary operation type. That is, the regeneration switch 322 is a non-locking type push switch that generates one ON pulse signal when pressed once. The pressing time of the regeneration switch 322 by the operator is adopted as one of criteria for determining whether or not each regeneration control after the reset regeneration control (details will be described later) can be executed.

  The regeneration prohibiting switch 323 is of an alternate operation type. That is, the regeneration prohibiting switch 323 is a lock-type push switch that is locked at the pressed position when pressed once, and returns to the original position when pressed again. If the regeneration prohibition switch 323 is pressed and locked, the current driving state of the engine 201 is maintained, and execution of each regeneration control after the reset regeneration control is prohibited. On / off of the regeneration prohibiting switch 323 is also one of the criteria for determining whether or not each regeneration control after the reset regeneration control can be executed.

  A regeneration lamp 328 is built in the regeneration switch 322 of the embodiment. That is, the regeneration switch 322 portion of the rocker switch 333 is configured as a switch with a regeneration lamp 328. Similarly, the regeneration prohibiting switch 323 of the embodiment includes a regeneration prohibiting lamp 329, and the regeneration prohibiting switch 323 portion of the rocker switch 333 is configured as a switch with a regeneration prohibiting lamp 329. Note that due to the characteristics of the structure of the rocker switch 333, when the regeneration prohibiting switch 323 is pressed and turned on, the regeneration switch 322 is turned off. If the regeneration prohibition switch 323 is in the locked state, the regeneration switch 322 cannot be turned on. If the regeneration prohibiting switch 323 is in the released state, the regeneration switch 322 can be pressed to turn it on.

  In the EEPROM of the ECU 311, an output characteristic map M (see FIG. 13) indicating the relationship between the rotational speed N of the engine 201 and the torque T (load) is stored in advance. Although not described in detail, the EEPROM of the ECU 311 includes an exhaust gas flow rate map for converting the exhaust gas flow rate from the relationship between the rotational speed N of the engine 201 and the fuel injection amount, and the rotational speed N of the engine 201 and the fuel injection. A PM emission amount map for converting the PM emission amount of the engine 201 from the relationship with the amount is also stored in advance. Each map such as the output characteristic map M is obtained by experiments or the like. In the output characteristic map M shown in FIG. 13, the rotational speed N is taken on the horizontal axis and the torque T is taken on the vertical axis. The output characteristic map M is a region surrounded by a solid line Tmx drawn upwardly. A solid line Tmx is a maximum torque line representing the maximum torque for each rotational speed N. In this case, if the model of the engine 201 is the same, the output characteristic maps M stored in the ECU 311 are all the same (common). As shown in FIG. 13, the output characteristic map M is divided into upper and lower parts by boundary lines BL1 and BL2 representing the relationship between the rotational speed N and the torque T at a predetermined exhaust gas temperature.

  The region above the first boundary line BL1 is a self-regenerating region in which PM deposited on the soot filter 244 can be oxidized and removed only by normal operation of the engine 201 (the oxidation action of the diesel oxidation catalyst 243 works). In the region between the first boundary line BL1 and the second boundary line BL2, PM is deposited on the soot filter 244 without being oxidized and removed only by the normal operation of the engine 201, but the assist regeneration control and reset regeneration control described later. This is a reproducible region that the exhaust filter 202 regenerates by execution. The region below the second boundary line BL2 is a non-reproducible region where the exhaust filter 202 does not regenerate even when the assist regeneration control or the reset regeneration control is executed. Since the exhaust gas temperature of the engine 201 in the non-renewable region is too low, the exhaust gas temperature does not rise to the regeneration boundary temperature even if the assist regeneration control or the reset regeneration control is executed from this state. That is, if the relationship between the rotational speed N of the engine 201 and the torque T is in a non-recoverable region, the exhaust filter 202 is not regenerated in the assist regeneration control or reset regeneration control (the particulate matter collecting ability of the soot filter 244 is restored). do not do). The exhaust gas temperature on the first boundary line BL1 is a regeneration boundary temperature (about 300 ° C.) that allows self-regeneration.

  The ECU 311 basically obtains the torque of the engine 201 from the rotational speed detected by the engine rotation sensor 314 and the throttle position detected by the throttle position sensor 316, calculates the target fuel injection amount using the torque and output characteristics, Fuel injection control for operating the common rail device 220 is executed based on the calculation result. The fuel injection amount of the common rail device 220 is mainly adjusted by adjusting the valve opening period of each fuel injection valve 219 and changing the injection period to each injector 215.

  As a control method (regeneration control method) of the engine 201, normal operation control (self-regeneration control) in which the exhaust filter 202 spontaneously regenerates only by normal operation of the engine 201, and the clogged state of the exhaust filter 202 exceed a specified level. Then, the exhaust gas temperature is obtained by combining the assist regeneration control for automatically raising the exhaust gas temperature, the reset regeneration control for raising the exhaust gas temperature using the post injection E, and the post injection E and the predetermined high speed rotation speed of the engine 201. There are non-work regeneration control (which may be referred to as emergency regeneration control) that raises the level and recovery regeneration control that can be executed when non-work regeneration control fails.

  In the normal operation control, the relationship between the rotational speed N and the torque T in the engine 201 is in the self-regeneration region of the output characteristic map M, and the engine 201 is adjusted to such an extent that the PM oxidation amount in the exhaust filter 202 exceeds the PM collection amount. The exhaust gas is hot.

  In the assist regeneration control, the exhaust filter 202 is regenerated by adjusting the opening degree of the intake throttle member 228 and after-injection D. That is, in the assist regeneration control, the intake air amount to the engine 201 is limited by closing the EGR valve member 231 and closing (squeezing) the intake throttle member 228 to a predetermined opening. Then, since the engine 201 load increases, the fuel injection amount of the common rail device 220 increases to maintain the set rotational speed, and the exhaust gas temperature of the engine 201 increases. In accordance with this, the diffusion combustion is activated by the after-injection D that is injected with a slight delay with respect to the main injection A, and the exhaust gas temperature of the engine 201 is raised. As a result, PM in the exhaust filter 202 is burned and removed. In any of the regeneration controls described below, the EGR valve member 231 is closed.

  In the reset regeneration control, when the assist regeneration control fails (when the clogged state of the exhaust filter 202 does not improve and PM remains), or when the accumulated driving time TI of the engine 201 is equal to or longer than a set time TI2 (for example, about 100 hours). It is done when it becomes. In the reset regeneration control, the exhaust filter 202 is regenerated by performing post injection E in addition to the assist regeneration control. That is, in the reset regeneration control, in addition to adjusting the opening degree of the intake throttle member 228 and after-injection D, unburned fuel is directly supplied into the exhaust filter 202 by post-injection E, and the unburned fuel is supplied by the diesel oxidation catalyst 243. By burning, the exhaust gas temperature in the exhaust filter 202 is raised (about 560 ° C.). As a result, the PM in the exhaust filter 202 is forcibly burned and removed.

  Non-work regeneration control is performed when the reset regeneration control fails (when the clogged state of the exhaust filter 202 does not improve and PM remains). In the non-work regeneration control, in addition to the reset regeneration control mode, the engine 201 is maintained at a predetermined high speed (for example, 2200 rpm, may be a maximum rotational speed or a high idle rotational speed) to maintain the rotational speed N of the engine 201. After raising the exhaust gas temperature, the exhaust gas temperature is also raised by the post injection E in the exhaust filter 202 (about 600 ° C.). As a result, the PM in the exhaust filter 202 is forcibly burned and removed under better conditions than the reset regeneration control. Note that the intake throttle member 228 in non-work regeneration control is not throttled, but is completely closed. The after-injection D in the non-work regeneration control is performed by retarding (retarding) the assist regeneration control and the reset regeneration control.

  In non-work regeneration control, the output of the engine 201 is limited to a non-working maximum output lower than the maximum output (for example, about 80% of the maximum output). In this case, since the rotational speed N of the engine 201 is maintained at a predetermined high rotational speed, the fuel injection amount of the common rail device 220 is adjusted so that the torque T is suppressed and the non-working maximum output is obtained.

  The recovery regeneration control is performed, for example, when the non-work regeneration control fails (when the clogged state of the exhaust filter 202 is not improved and PM is excessively deposited). The recovery reproduction control of the embodiment is executed in two stages of recovery first reproduction control and recovery second reproduction control. The recovery first regeneration control gradually regenerates the exhaust filter 202 by gradually burning and removing the PM in the exhaust filter 202 in a situation where there is a risk of runaway combustion of the excessively accumulated PM. In the recovery second regeneration control, the exhaust filter 202 is promptly regenerated in a situation where there is no risk of runaway combustion.

  The recovery recovery control as a whole is basically performed in the same manner as in the non-work regeneration control mode. However, in the recovery first regeneration control, for example, fuel injection in post injection E is performed in order to prevent runaway combustion of overdeposited PM. For example, by reducing the amount, the temperature TP3 (for example, about 500 ° C.) in which the exhaust gas temperature in the exhaust filter 202 is lower than the non-work regeneration control is targeted and for a long time (for example, within about 3 to 3.5 hours). The PM in the exhaust filter 202 is gradually burned and removed. In the recovery first regeneration control, the output of the engine 201 is limited to the maximum output during recovery that is lower than the maximum output during non-working (for example, about 80% of the maximum output). In this case, the fuel injection amount of the common rail device 220 is adjusted so that not only the torque T of the engine 201 but also the rotational speed N is suppressed and the maximum output during recovery is obtained.

  In the recovery second regeneration control, the exhaust gas temperature in the exhaust filter 202 is higher than that in the recovery first regeneration control by closing the intake throttle member 228, after-injection D, post-injection E, and the predetermined high-speed rotation speed of the engine 201. The exhaust filter 202 is quickly regenerated with the target of TP4 (for example, about 600 ° C.). That is, the mode of recovery second regeneration control is the same as the mode of non-work regeneration control. The main difference between the recovery first regeneration control and the recovery second regeneration control is the injection amount of the post injection E. For example, the injection amount of the post injection E during the recovery first regeneration control is the post injection amount during the recovery second regeneration control. It is less than the injection amount of the injection E.

  In addition to normal operation control, of course, in assist regeneration control and reset regeneration control, it is possible to transmit the power of the engine 201 to, for example, the operating unit of the work implement to perform various operations (the engine 201 can be operated in normal operation). Can drive). In the non-work regeneration control and the recovery regeneration control, the engine 201 is driven exclusively for PM combustion removal, and for example, the operating unit of the work implement is not driven by the power of the engine 201.

(5). Exhaust Filter Regeneration Control Mode Next, an example of the exhaust filter 202 regeneration control by the ECU 311 will be described with reference to the flowcharts of FIG. Each regeneration control described above is executed based on a command from the ECU 311. That is, the algorithm shown in the flowcharts of FIG. 14 and subsequent figures is stored in the EEPROM of the ECU 311. Each of the above-described regeneration controls is executed by calling the algorithm into the RAM and then processing the CPU.

  As shown in FIG. 14, in the exhaust filter 202 regeneration control, first, if the key switch 331 is on (S101: YES), detection by the engine rotation sensor 314, the coolant temperature sensor 319, the differential pressure sensor 281 and the DPF temperature sensor 282 is detected. The value, the opening degree of the intake throttle member 228 and the EGR valve member 231 and the fuel injection amount by the common rail device 220 are read (S102). Next, if the cumulative driving time TI after executing the assist regeneration control, reset regeneration control or non-work regeneration control in the past is less than the set time TI1 (for example, 50 hours) (S103: NO), the exhaust filter 202 The amount of PM deposition is estimated (S104). In step S104, the PM accumulation amount estimation by the P method based on the detection value of the differential pressure sensor 281 and the exhaust gas flow rate map, the detection value of the engine rotation sensor 314, the fuel injection amount, the PM emission amount map, and the exhaust gas flow rate map. Based on the above, the PM deposition amount is estimated by the C method. If any of the PM accumulation amounts in the P method and the C method is equal to or greater than a prescribed amount Ma (for example, 8 g / l) (S105: YES), assist regeneration control is executed (S106).

  When a predetermined time TI3 (for example, 30 minutes) has elapsed since the start of the assist regeneration control (S107: YES), the assist regeneration control is terminated and the normal operation control is resumed. If it is within a predetermined time from the start of the assist regeneration control (S107: NO), the PM accumulation amount in the exhaust filter 202 is estimated by the C method (S108). As can be seen from this point, in the embodiment, the PM deposition amount is estimated by the C method during the execution of each regeneration control, and the PM deposition amount is estimated by the P method otherwise. The PM accumulation amount estimation method is changed depending on whether or not each regeneration control is being executed. If the PM accumulation amount in the method C is less than a prescribed amount Ma (for example, 6 g / l) (S109: YES), the assist regeneration control is terminated and the normal operation control is returned to. When any of the PM accumulation amounts in the P method and the C method is equal to or greater than the prescribed amount Ma (S109: NO), if a predetermined time TI4 (for example, 10 minutes) has elapsed in this state (S110: YES), reset The process proceeds to step S201, which is a reset standby mode before reproduction control.

  Returning to step S103, when the cumulative driving time TI is equal to or longer than the set time TI1 and further equal to or longer than the set time TI2 (for example, 100 hours) (S111: YES), the process proceeds to step S201 which is a reset standby mode. At this stage, the regeneration lamp 328 blinks and prompts the operator to execute reset regeneration control. When the regeneration prohibition switch 323 is off and the regeneration switch 322 is on for a predetermined time (for example, 3 seconds), if the exhaust gas temperature TP in the exhaust filter 202 is equal to or higher than TP1 (for example, 250 ° C.) (S201: YES), reset regeneration is performed. Control is executed (S202). At this stage, the exhaust temperature alarm lamp 326 is turned on together with the regeneration lamp 328.

  When the regeneration prohibition switch 323 is on, the regeneration switch 322 is off, or the exhaust gas temperature TP in the exhaust filter 202 is lower than TP1 (S201: NO), the PM accumulation amount in the exhaust filter 202 is estimated by the C method (S203). ), When a predetermined time TI5 (for example, 1 hour) elapses with the PM accumulation amount in the method C being less than a prescribed amount Mr (for example, 6 g / l) (S204: YES), the normal standby control is exited from the reset standby mode. Return to. When step S204 is NO and a predetermined time TI6 (for example, 3 hours) has elapsed (S205: YES), there is a concern about the possibility of PM over-deposition, so in the non-work standby mode before non-work regeneration control. The process proceeds to a certain step S301.

  During execution of the reset regeneration control, the PM accumulation amount in the exhaust filter 202 is estimated by the P method and the C method (S206). One of the PM deposition amounts in the P method and the C method is less than a prescribed amount Mr (for example, 10 g / l) (S207: NO), and the exhaust gas temperature TP in the exhaust filter 202 is TP2 (for example, 600 ° C.). If the predetermined time TI7 (for example, 25 minutes) elapses in the above state (S208: YES) or if the predetermined time TI8 (for example, 30 minutes) elapses from the start of the reset regeneration control (S209: YES), the reset regeneration control ends. Return to normal operation control. If any of the PM accumulation amounts in the P method and the C method is equal to or greater than the prescribed amount Mr (S207: YES), it is considered that the reset regeneration control has failed, and there is a concern about the possibility of PM overdeposition. The process proceeds to step S301, which is the non-work standby mode before.

  As shown in FIG. 15, in the non-work standby mode, first, the PM accumulation amount in the exhaust filter 202 is estimated by the P method and the C method (S301). At this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned on to notify the operator of the execution of the non-work regeneration control. If any of the PM deposition amounts in the P method and the C method is less than a specified amount Mb (for example, 12 g / l) (S302: NO) and within a predetermined time TI9 (for example, 10 hours) (S303: NO), Wait until the set non-work transition condition is satisfied (S304). If any of the PM accumulation amounts in the P method and the C method is the specified amount Mb or more (S302: YES), or if a predetermined time TI9 (for example, 10 hours) has elapsed in the non-work standby mode (S303: YES) Since there is a concern about the possibility of PM overdeposition, the process proceeds to step S401 which is a recovery standby mode before the recovery regeneration control. In the non-work standby mode, the alarm buzzer 330 sounds intermittently when the PM accumulation amount is less than 10 g / l, for example, and the alarm buzzer 330 sounds continuously when the PM accumulation amount is 10 g / l or more, for example. Depending on the sounding state of the alarm buzzer 330, the operator can roughly grasp the clogging of the exhaust filter 202.

  The non-work transition condition shown in step S304 is that the interlock switch 324 is in the released state (off), the regeneration switch 322 is on for a predetermined time (for example, 3 seconds), the regeneration prohibiting switch 323 is off, and the engine 201 is at a low idle rotational speed (no The minimum rotation speed at the time of load) and the detected value of the cooling water temperature sensor 319 include five conditions, ie, a predetermined value (for example, 65 ° C.) or more. In this case, if the detected value of the coolant temperature sensor 319 is equal to or greater than a predetermined value, it is considered that the engine 201 has been warmed up.

  In step S304, when the three conditions that the interlock switch 324 is in the released state (off), the engine 201 is at the low idle rotation speed, and the detected value of the cooling water temperature sensor 319 is equal to or greater than a predetermined value are satisfied, the engine warning lamp 325 and the regeneration are performed. The regeneration lamp 328 blinks while the request lamp 327 is kept on, and prompts the operator to execute non-work regeneration control. If the regeneration prohibiting switch 323 is turned off and the regeneration switch 322 is turned on for a predetermined time (S304: YES), five non-work transition conditions are satisfied, and non-work regeneration control is executed (S305). At this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned off, and the exhaust temperature warning lamp 326 is turned on together with the regeneration lamp 328.

  While the non-work regeneration control is being executed, the PM accumulation amount in the exhaust filter 202 is estimated by the C method (S306). The PM accumulation amount in the method C is less than a prescribed amount Ms (for example, 8 g / l) (S307: YES), and the exhaust gas temperature TP in the exhaust filter 202 is TP2 (for example, 600 ° C.) or more for a predetermined time TI10 ( For example, if 25 minutes have elapsed (S308: YES), or if a predetermined time TI11 (for example, 30 minutes) has elapsed since the start of non-work regeneration control (S309: YES), the non-work regeneration control is terminated and normal operation control is performed. Return. When the PM accumulation amount in the method C is equal to or greater than the prescribed amount Ms (S307: YES), if a predetermined time TI12 (for example, 30 minutes) elapses in this state (S310: YES), it is regarded as non-work regeneration control failure, and PM Since there is concern about the possibility of over-deposition, the process proceeds to step S401, which is a recovery standby mode before the recovery regeneration control.

  If the interlock switch 324 is locked (ON) or the regeneration prohibiting switch 323 is turned on during execution of non-work regeneration control (S311: YES), non-work regeneration control is interrupted. At this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned on, and the regeneration lamp 328 blinks. If the regeneration prohibiting switch 323 is on, the regeneration prohibiting lamp 329 is also lit. If the non-work regeneration control is interrupted, the non-work regeneration control is resumed by turning on the regeneration switch 322.

  As shown in FIG. 16, in the recovery standby mode, the system waits until a preset recovery transition condition is satisfied (S401). At this stage, similarly to the non-work standby mode, the engine warning lamp 325 and the regeneration request lamp 327 are turned on to notify the operator of the execution of the recovery regeneration control. The recovery transition condition shown in step S401 is basically the same as the non-work transition condition, but the pressing time of the regeneration switch 322 is longer than that in the non-work transition condition. That is, the recovery transition condition is that the interlock switch 324 is in the released state (off), the regeneration switch 322 is on for a predetermined time (for example, 10 seconds), the regeneration prohibition switch 323 is off, and the engine 201 is at a low idle speed (no load). The minimum rotation speed) and the detected value of the cooling water temperature sensor 319 consist of five conditions: a predetermined value (for example, 65 ° C.) or more. Also in this case, if the detected value of the coolant temperature sensor 319 is equal to or greater than a predetermined value, it is considered that the engine 201 has been warmed up.

  In step S401, when the three conditions that the interlock switch 324 is released (off), the engine 201 is at a low idle rotation speed, and the detected value of the coolant temperature sensor 319 is equal to or greater than a predetermined value are satisfied, the engine alarm lamp 325 and the regeneration are performed. The regeneration lamp 328 blinks while the request lamp 327 is kept on, and prompts the operator to execute the reset regeneration control. If the regeneration prohibiting switch 323 is turned off and the regeneration switch 322 is turned on for a predetermined time (S401: YES), five recovery transition conditions are satisfied, and recovery first regeneration control is executed (S402). At this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned off, and the exhaust temperature warning lamp 326 is turned on together with the regeneration lamp 328.

  During the execution of the first recovery control, the PM accumulation amount in the exhaust filter 202 is estimated by the C method (S404), and the PM accumulation amount by the C method is less than a specified amount Mc (for example, about 8 to 10 g / l). If so (S405: YES), the process proceeds to recovery second regeneration control (S407). If the interlock switch 324 is locked (ON) or the regeneration prohibiting switch 323 is turned on (S406: YES) during the recovery first regeneration control, the recovery first regeneration control is interrupted. At this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned on, and the regeneration lamp 328 blinks. If the regeneration prohibiting switch 323 is on, the regeneration prohibiting lamp 329 is also lit. When the recovery first regeneration control is interrupted, the recovery first regeneration control is resumed by turning on the regeneration switch 322. If the PM accumulation amount in the method C does not decrease below the prescribed amount Mc (S405: NO), and a predetermined time TI13 (for example, about 3 to 3.5 hours) elapses from the start of the recovery first regeneration control (S403: YES) ) Even if the recovery regeneration control is further continued, it is determined that the exhaust filter 202 regeneration is difficult, and the process returns. In this state, an alarm is issued and the engine is stopped.

  In the recovery second regeneration control, if a predetermined time TI14 (for example, 30 minutes) elapses from the start of the recovery second regeneration control (S408: YES), the recovery second regeneration control is terminated and the normal operation control is resumed. If the interlock switch 324 is locked (ON) or the regeneration prohibiting switch 323 is turned on during execution of the recovery second regeneration control (S409: YES), the recovery second regeneration control is interrupted. Even at this stage, the engine warning lamp 325 and the regeneration request lamp 327 are turned on, and the regeneration lamp 328 blinks. If the regeneration prohibiting switch 323 is on, the regeneration prohibiting lamp 329 is also lit. When the recovery second regeneration control is interrupted, the recovery second regeneration control is resumed by turning on the regeneration switch 322.

  Now, in the exhaust filter 202 regeneration control of the embodiment, when a set time TI1 (for example, 50 hours) elapses after executing the reset regeneration control or the non-work regeneration control, the non-work regeneration control is performed without going through the reset regeneration control. The arrow mode that can be executed is set. In step S111 of FIG. 14, if the cumulative drive time TI is not less than the set time TI1 and not more than TI2 (S111: NO), the process proceeds to step S501 (see FIG. 17). In step S501, if the reset regeneration control or the non-work regeneration control has been executed previously (S501: YES), the regeneration request lamp 327 is turned on and the regeneration lamp 328 blinks, and the non-work without performing the reset regeneration control. Notifies that the arrow mode capable of playback control can be executed. Unlike the non-work standby mode, the engine warning lamp 325 is not lit. If the interlock switch 324 is in the released state (off), the regeneration prohibiting switch 323 is off, and the regeneration switch 322 is turned on for a predetermined time (for example, 10 seconds) (S502: YES), the standby state of the arrow mode is entered (S503). ).

  In step S503, the interlock switch 324 is in the released state (off), the regeneration switch 322 is on for a predetermined time (for example, 3 seconds), the regeneration prohibiting switch 323 is off, and the engine 201 is at a low idle speed (minimum level at no load). When the five conditions that the rotation speed) and the detected value of the cooling water temperature sensor 319 are equal to or higher than a predetermined value (for example, 65 ° C.) are satisfied (S503: YES), non-work regeneration control in the arrow mode is executed (S504). At this stage, the regeneration request lamp 327 is turned off, and the exhaust temperature alarm lamp 326 is turned on together with the regeneration lamp 328.

  The mode of the non-work regeneration control (S504 to S510) in the arrow mode is basically the same as the non-work regeneration control (S305 to S311) when the reset regeneration control is passed. When the PM accumulation amount by the C method is equal to or greater than the prescribed amount Ms (S506: YES), if a predetermined time TI17 (for example, 30 minutes) has passed in this state (S509: YES), the non-work regeneration control in the arrow mode has failed. Since there is a concern about the possibility of PM over-deposition, the same applies to the transition to step S401, which is a recovery standby mode before recovery regeneration control. When such control is employed, the operator can intentionally execute non-work regeneration control to burn and remove PM in the exhaust filter 202, and the maintainability of the exhaust filter 202 can be improved.

(6). Summary As is apparent from the above description and FIGS. 10, 15, and 16, a common rail engine 201 and an exhaust gas purification device 202 disposed in the exhaust path of the engine 201 are provided. In the exhaust gas purification system capable of executing a plurality of regeneration controls for burning and removing particulate matter deposited on the exhaust gas, the plurality of regeneration controls include a combination of post-injection E and a predetermined high speed rotation speed to increase the exhaust gas temperature. At least a non-work regeneration control and a recovery regeneration control that can be executed when the non-work regeneration control fails. In the non-work regeneration control and the recovery regeneration control, the non-work regeneration control is used only for combustion removal of the particulate matter. The engine 201 is driven, and in the recovery regeneration control, the exhaust gas temperature is lower than that in the non-work regeneration control, and Since it is set to take a longer time than the non-work regeneration control, even if the particulate matter is excessively accumulated in the exhaust gas purification device 202, the particulate matter is generated without causing runaway combustion. Substances can be burned off. Therefore, the exhaust gas purification device 202 can be prevented from being damaged (melted) or excessively discharged.

  Further, when the non-work regeneration control fails, the process shifts to a recovery standby mode in which a preset recovery transition condition (see S401 in FIG. 16) is satisfied, and when the recovery transition condition is not satisfied, the recovery standby is performed. In addition to waiting in the mode, the recovery playback control is interrupted when a preset recovery release condition (see S406 and S409 in FIG. 16) is satisfied during execution of the recovery playback control. Once the transition is made, the transition to only the recovery reproduction control or the recovery standby mode is performed thereafter. Therefore, regeneration control that causes runaway combustion is not performed, and the occurrence of runaway combustion can be prevented.

  Further, when the recovery regeneration control is completed, the operation returns to the normal operation control, so that it is not necessary for the operator to perform, for example, a return operation for mode switching, and the operator's operation burden can be reduced.

  As apparent from the above description and FIGS. 10 and 14 to 16, the common rail engine 201 and the exhaust gas purification device 202 disposed in the exhaust path of the engine 201 are provided, and are deposited in the exhaust gas purification device. In the exhaust gas purification system capable of executing a plurality of regeneration controls for burning and removing the particulate matter, the plurality of regeneration controls include a reset regeneration control for increasing the exhaust gas temperature using the post injection E, and a post injection E. At least a non-work regeneration control that increases the exhaust gas temperature by combining a predetermined high-speed rotation speed and a recovery regeneration control that can be executed when the non-work regeneration control fails, and the non-work regeneration control and the recovery regeneration In the control, the engine is driven exclusively for the combustion removal of the particulate matter. The engine 201 is in the recovery regeneration control is not a normal operation. That is, the non-work regeneration control and the recovery regeneration control exist as modes for avoiding a crisis such as prevention of damage (melting damage) of the exhaust gas purification device 202 and prevention of excessive emission.

  In addition, when setting the transition from the reset regeneration control to the recovery regeneration control through the non-work regeneration control, and when shifting from the reset regeneration control to the non-work regeneration control, a preset non-work transition is performed. When shifting from the non-work regeneration control to the recovery regeneration control via the non-work standby mode in which the condition (see S304 in FIG. 15) is waited for, the preset recovery transition condition (see S401 in FIG. 16). When the transition conditions are not satisfied, the process waits in the standby mode when the transition conditions are not satisfied. Only will be migrated. Therefore, regeneration control that causes runaway combustion is not performed, occurrence of runaway combustion can be prevented, and crisis avoidance such as prevention of damage (melting damage) of the exhaust gas purification device 202 and prevention of excessive emission can be reliably ensured. Can be done.

  In the non-work regeneration control, the output of the engine 201 is limited to a non-working maximum output lower than the maximum output, and in the recovery regeneration control, the output of the engine 201 is lower than the non-work maximum output. Since the maximum output at the time of recovery is limited, when the non-work regeneration control or the recovery regeneration control is executed, excessive exhaust gas temperature rise and pressure rise are prevented, and the exhaust gas purifying device 202 and the like caused by temperature rise are prevented. It is possible to suppress the deterioration of the exhaust system parts and the occurrence of exhaust gas leakage from the joint of the exhaust system parts due to the pressure increase.

(7). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, in the exhaust gas purification system of the embodiment, both the regeneration switch 322 and the regeneration prohibition switch 323 are provided. However, the present invention is not limited to this. The same control as that of the embodiment can be executed.

  Further, even if the regeneration switch 322 is omitted and only the regeneration prohibiting switch 323 is used, the same control as in the above-described embodiment can be executed. In this case, the regeneration prohibiting switch 323 may be an alternate operation type. Then, as shown in step S201 of FIG. 18, step S304 of FIG. 19, step S401 of FIG. 20, step S502 of FIG. 21, and step S503 of FIG. It is possible to determine whether or not to execute each regeneration control after the reset regeneration control. In addition, the structure of each part is not limited to embodiment of illustration, A various change is possible in the range which does not deviate from the meaning of this invention.

201 Engine 202 Exhaust filter 220 Common rail device 228 Intake throttle member 231 EGR valve member 240 Purification casing 243 Diesel oxidation catalyst 244 Soot filter 281 Differential pressure sensor 282 DPF temperature sensor 311 ECU
322 regeneration switch 323 regeneration prohibition switch 324 interlock switch 325 engine alarm lamp 326 exhaust temperature alarm lamp 327 regeneration request lamp 328 regeneration lamp 329 regeneration prohibition lamp

Claims (3)

In an exhaust gas purification system comprising a common rail engine and an exhaust gas purification device disposed in an exhaust path of the engine, and capable of performing a plurality of regeneration controls for burning and removing particulate matter accumulated in the exhaust gas purification device ,
The plurality of regeneration controls include a reset regeneration control for increasing the exhaust gas temperature using post injection, a non-work regeneration control for increasing the exhaust gas temperature by combining post injection and a predetermined high-speed rotation speed, and the non-working control. And at least recovery recovery control that can be executed when playback control fails,
In the non-work regeneration control and the recovery regeneration control, the engine is driven exclusively for the combustion removal of the particulate matter,
The reset regeneration control is shifted from the reset regeneration control to the recovery regeneration control through the non-work regeneration control, and the reset regeneration is performed when the accumulated time after the execution of the reset regeneration control or the non-work regeneration control exceeds a predetermined time. It is set to shift to the non-work regeneration control without going through control,
When shifting from the reset regeneration control to the non-work regeneration control, the non-work regeneration control is performed via a non-work standby mode in which a preset non-work transition condition is satisfied, and without passing through the reset regeneration control. When transitioning to, via an arrow mode that waits for the establishment of a preset non-work transition condition, and when transitioning from the non-work regeneration control to the recovery regeneration control, waits for the establishment of a preset recovery transition condition Through the recovery standby mode, and when each of the transition conditions is not satisfied, wait in the respective standby mode or the arrow mode ,
Exhaust gas purification system. In the non-work regeneration control, the engine output is limited to a non-working maximum output lower than the maximum output.
The exhaust gas purification system according to claim 1. In the recovery reproduction control, the engine output is limited to a recovery maximum output lower than the non-working maximum output.
The exhaust gas purification system according to claim 2 .

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