JP2011017256A - Engine device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine device comprising an engine as a power source, an exhaust gas purifying filter device disposed in an exhaust path of the engine, and a control means for performing forced regeneration control of the filter device on the basis of a clogging state of the filter device and a driving state of the engine, wherein both the forced regeneration control and forced low rotation control can be established and executed.SOLUTION: The device includes a forced low rotation operation means 35 for executing forced low rotation control for forcedly reducing engine rotation speed to the predetermined low rotation speed. The control means 311 preferentially executes the forced low rotation control when the forced low rotation operation means 35 is actuated regardless of the necessity of the forced regeneration control.

Description

  The present invention relates to an engine device mounted on a work machine (for example, agricultural work machine, construction machine, ship, etc.).

  Conventionally, work machines such as combines and hydraulic excavators have reduced fuel consumption and noise by automatically reducing the engine speed to a low idle speed by pressing a pushbutton switch located in the control section. A so-called forced low-rotation control (one-touch decel control) technique is employed (see Patent Document 1, etc.).

  On the other hand, as higher-order exhaust gas regulations related to diesel engines are applied, it is desired to install exhaust gas purification devices that purify air pollutants in exhaust gas on work machines equipped with diesel engines. It's getting on. For example, DPF (diesel particulate filter) is known as an exhaust gas purification device (see Patent Documents 2 and 3). In the DPF, particulate matter in the exhaust gas accumulates on the soot filter with the passage of time, so that the soot filter is regenerated by burning off the particulate matter when the diesel engine is driven. As is well known, the soot filter regeneration operation occurs when the exhaust gas temperature is equal to or higher than the reproducible temperature (for example, about 300 ° C.).

  If the exhaust gas temperature remains below the renewable temperature, a large amount of particulate matter accumulates in the soot filter, resulting in clogging of the soot filter and increased exhaust pressure, resulting in engine trouble. . As an example of a measure for solving such a problem, when the particulate matter accumulation amount reaches a predetermined amount, the output (rotation speed or load) of the diesel engine is increased and the exhaust gas temperature guided to the DPF is forcibly increased. A forced regeneration control is known in which the particulate matter collected by DPF is burned and removed by combustion.

JP-A-9-88650 JP 2000-145430 A Japanese Patent Laid-Open No. 2003-27922

  As described above, forced low-rotation control (one-touch decel control) is control that lowers the output of the engine, whereas forced regeneration control is control that increases the output of the engine, and the two are in a contradictory relationship. However, when the DPF is mounted on the work machine, it is necessary to achieve both forced low rotation control (one-touch decel control) and forced regeneration control. This invention is made in view of such a point, and it aims at providing the engine apparatus which can perform both forced low-rotation control (one-touch decel control) and forced regeneration control.

  The invention according to claim 1 is based on an engine as a power source, an exhaust gas purifying filter device disposed in an exhaust path of the engine, a clogged state of the filter device, and a driving state of the engine. A forced low rotation operation means for executing forced low rotation control for forcibly reducing the engine speed to a predetermined low speed. The control means is configured to preferentially execute the forced low rotation control when the forced low rotation operation means is turned on regardless of the necessity of the forced regeneration control. Is.

  According to a second aspect of the present invention, in the engine device according to the first aspect, when the control unit operates the moving system operating unit or the working system operating unit for the work machine on which the engine device is mounted, The rotation control is stopped, and if the clogged state in the filter device has reached a preset state at this time, the forced regeneration control is executed, while the clogged state in the filter device is set in advance. If the engine speed has not been reached, the engine speed is returned to the original speed before the decrease.

  According to a third aspect of the present invention, in the engine device according to the first or second aspect, the control means has reached a state in which the clogged state in the filter device is set in advance during the execution of the forced low rotation control. Sometimes, the notification means connected to the control means notifies the user.

  According to the first aspect of the present invention, an engine as a power source, a filter device for purifying exhaust gas disposed in an exhaust path of the engine, the filter device based on a clogged state and a driving state of the engine. An engine device comprising control means for executing forced regeneration control of the device, forcibly low speed operation means for executing forced low speed control for forcibly reducing the engine speed to a predetermined low speed The control means is configured to preferentially execute the forced low rotation control when the forced low rotation operation means is turned on regardless of the necessity of the forced regeneration control. Thus, the forced regeneration control for increasing the output of the engine is not performed repeatedly during the execution of the forced low speed control for decreasing the output of the engine. For this reason, two fuel injection controls (forced low-rotation control and forced regeneration control) that require operations that conflict with the engine coexist, and the respective controls can be executed efficiently without overlapping. Therefore, there is an effect that it is possible to achieve both fuel economy saving and exhaust gas purification in the working machine. In addition, there is an advantage that the operator feels uncomfortable due to a sudden change in engine sound.

  Further, according to the invention of claim 2, the control means stops the forced low rotation control when operating the moving system operating means or the working system operating means for the work machine on which the engine device is mounted, When the clogged state in the filter device has reached a preset state, the forced regeneration control is executed, while when the clogged state in the filter device has not reached the preset state, Since the engine speed is configured to return to the original speed before the decrease, even if the operator forgets the return operation from the forced low speed control, the operation to start the work implement or the work The output of the engine can be easily ensured only by the operation of driving the part. Therefore, when returning from the forced low speed control, the engine is started at a low speed or the working unit is driven, causing the engine to suddenly stop due to insufficient output or overload. There is an effect that it can be surely prevented.

  Further, according to the invention of claim 3, the control means is connected to the control means when the clogging state in the filter device reaches a preset state during execution of the forced low rotation control. Since the notification means is configured to notify the operator, the operator can grasp whether or not the filter device is clogged even during execution of the forced low rotation control prohibiting the forced regeneration control. In addition, it is possible to call attention to the clogging of the filter device. Since the forced low-rotation control is executed, there is an advantage that troubles such as clogging of the filter device and failure may be avoided.

It is a left view of the combine in 1st Embodiment. It is a top view of a combine. It is a front view which shows the positional relationship of the diesel engine with respect to a traveling body. It is a side view of the intake manifold installation side of a diesel engine. It is a side view of the exhaust manifold installation side of a diesel engine. It is a side view of the flywheel installation side of a diesel engine. It is a top view of a diesel engine. It is a section explanatory view of DPF. It is a plane explanatory view of a common rail system. It is sectional explanatory drawing of the upper part side of a diesel engine. It is fuel system explanatory drawing of a diesel engine. It is a flowchart of forced low rotation control. It is a side view of the hydraulic excavator in 2nd Embodiment. It is a top view of a hydraulic excavator. It is fuel system explanatory drawing of a diesel engine. It is a flowchart of forced low rotation control. It is a side view by the side of the exhaust manifold installation of the electronic governor type diesel engine in a 3rd embodiment. It is a side view of the intake manifold installation side of an electronic governor type diesel engine. It is a top view of an electronic governor type diesel engine. It is a side view of the flywheel installation side of an electronic governor type diesel engine. It is a side view by the side of the cooling fan installation side of an electronic governor type diesel engine. It is a functional block diagram of an electronic governor controller. It is a flowchart of forced low rotation control.

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

(1). 1st Embodiment FIGS. 1-12 has shown 1st Embodiment at the time of applying this invention to the combine which is a working machine. 1 to 3, the left side in the forward direction of the traveling machine body 1 is simply referred to as the left side, and the right side in the forward direction is also simply referred to as the right side. For convenience, these are used as a reference for the positional relationship between the four sides and the top and bottom of the combine.

(1-1). First, the overall structure of the combine which is the first embodiment of the working machine will be described with reference to FIGS. The combine includes a traveling machine body 1 supported by a pair of left and right traveling crawlers 2. At the front part of the traveling machine body 1, a six-row mowing device 3 that takes in while harvesting cereal is mounted by a single-acting lifting hydraulic cylinder 4 so as to be movable up and down around the mowing rotation fulcrum shaft 4a. Yes. A threshing device 5 having a feed chain 6 and a grain tank 7 for storing grain after threshing are mounted on the traveling machine body 1 side by side. In this case, the threshing device 5 is disposed on the left side in the traveling direction of the traveling machine body 1, and the grain tank 7 is disposed on the right side in the traveling direction of the traveling machine body 1. A swivelable grain discharge auger 8 is provided at the rear of the traveling machine body 1. The grain inside the grain tank 7 is configured to be discharged to a truck bed, a container, or the like from a throat throw 9 of the grain discharge auger 8. The threshing device 5 and the grain discharge auger 8 correspond to the working unit. An operation cabin 10 is provided on the right side of the reaping device 3 and on the front side of the grain tank 7.

  A steering handle 11 and a driver seat 12 are arranged in the driver cabin 10. As shown in FIG. 2, in the driving cabin 10, a step (not shown) in which an operator gets on, a handle column 14 provided with a steering handle 11, and a shift operation provided on a lever column 15 on the left side of the driving seat 12. A main transmission lever 16, a sub transmission lever 17, and a working clutch lever 18 for turning on and off a working clutch (a mowing clutch and a threshing clutch, not shown) are arranged. A diesel engine 70 as a power source is disposed in the traveling machine body 1 below the driver seat 12.

  As shown in FIG. 1, left and right track frames 21 are arranged on the lower surface side of the traveling machine body 1. The track frame 21 includes a drive sprocket 22 that transmits the power of the engine 70 to the traveling crawler 2, a tension roller 23 that maintains the tension of the traveling crawler 2, and a plurality of track rollers that hold the ground side of the traveling crawler 2 in a grounded state. 24 and an intermediate roller 25 that holds the non-grounded side of the traveling crawler 2 are provided. The driving sprocket 22 supports the front side of the traveling crawler 2, the tension roller 23 supports the rear side of the traveling crawler 2, the track roller 24 supports the grounding side of the traveling crawler 2, and the intermediate roller 25 supports the non-traveling crawler 2. Support the ground side. The output of the diesel engine 70 is transmitted to the transmission case 19, the output of the diesel engine 70 is shifted by the transmission case 19, and the traveling crawler 2 is driven by the transmission output of the transmission case 19.

  As shown in FIGS. 1 and 2, below the cutting frame 221 connected to the cutting rotation fulcrum shaft 4 a of the cutting device 3, a clipper-type cutting blade device that cuts the stock of uncut grain culm in the field. 222 is provided. In front of the mowing frame 221, a stalk raising apparatus 223 for 6 stalks that raises uncut cereals in the field is arranged. Between the culm pulling device 223 and the front end (feed start side) of the feed chain 6, a culm conveying device 224 that conveys the chopped culm harvested by the cutting blade device 222 is arranged. In addition, in front of the lower part of the grain culling pulling device 223, a weeding body 225 for six strips for weeding the uncut grain culm in the field is projected. While the traveling crawler 2 is driven by the diesel engine 70 to move in the field, the reaping device 3 is driven to continuously shave the uncut grain culm on the field.

  As shown in FIG. 1 to FIG. 3, the threshing device 5 includes a handling cylinder 226 for threshing threshing, a rocking sorter 227 for sorting out shed matter falling below the handling cylinder 226, and a tang fan 228. The processing cylinder 229 for reprocessing the threshing waste taken out from the rear part of the handling cylinder 226 and the dust exhaust fan 230 for discharging the dust at the rear part of the swing sorter 227 are provided. In addition, the rotating shaft of the handling cylinder 226 extends along the conveying direction of the cereal by the feed chain 6 (in other words, the traveling direction of the traveling machine body 1). The stock source side of the corn straw conveyed from the reaping device 3 by the corn straw conveying device 224 is inherited by the feed chain 6 and is nipped and conveyed. Then, the tip side of the cereal cocoon is carried into the handling chamber of the threshing device 5 and threshed by the handling drum 226.

  As shown in FIG. 1 and FIG. 2, on the lower side of the swing sorter 227, there is a first conveyor 231 that takes out the grain (first thing) sorted by the swing sorter 227, and a branch raft is attached. A second conveyor 232 for taking out second items such as grains is provided. The two conveyors 231 and 232 are horizontally installed on the upper surface side of the traveling machine body 1 above the rear part of the traveling crawler 2 in a side view in order of the first conveyor 231 and the second conveyor 232 from the front side in the traveling direction of the traveling machine body 1. . Note that the swing sorter 227 is reciprocally swung back and forth and up and down at a substantially constant speed by the swing drive shaft 242. The cereals that have leaked from the receiving net 237 stretched below the handling cylinder 226 are subjected to rocking sorting (specific gravity sorting) by the feed pan 238 and the chaff sheave 239 of the rocking sorting board 227.

  When the cereal is oscillated and sorted by the oscillating sorter 227, the grain being cerealed falls downward from the grain sieve 240 of the oscillating sorter 227. From the grain that has fallen from the Glen Sheave 240, the dust in the grain is removed by the sorting air from the Kara fan 228 and falls first onto the conveyor 231. A whipping cylinder 233 extending in the vertical direction is connected to a terminal portion of the first conveyor 231 that protrudes outward from one side wall (in the embodiment, the right side wall) near the grain tank 7 in the threshing device 5. . The grain taken out first from the conveyor 231 is carried into the grain tank 7 through the whipped cylinder 233 and collected in the grain tank 7. In addition, along the inclination of the rear surface of the grain tank 7, the raising cylinder 233 is erected on the rear side of the grain tank 7 in a backward inclined posture in which the upper end side of the whipping cylinder 233 is inclined backward.

  As shown in FIGS. 1 and 2, the swing sorter 227 causes the second sort such as grain with branch stems to fall onto the second conveyor 232 from the chaff sheave 239 by swing sort (specific gravity sort). It is configured. A tang fan 228 for wind-selecting the second item falling below the chaff sheave 239 is provided. As for the second thing that has fallen from the chaff sheave 239, dust and swarf in the grain are removed by the sorting air from the sorting fan 241 and dropped onto the second conveyor 232. The terminal part which protruded outward from the one side wall near the grain tank 7 in the threshing device 5 in the second conveyor 232 crosses the whipping cylinder 233 and passes through a reduction cylinder 236 extending in the front-rear direction, to a feed pan 238. The second item is returned to the upper surface side of the feed pan 238 and re-sorted.

  On the other hand, a waste chain 234 is disposed on the rear end side (feed end side) of the feed chain 6. The slag passed from the rear end side of the feed chain 6 to the sewage chain 234 (the slag from which the grain has been threshed) is discharged to the rear of the traveling machine body 1 in a long state, or the rear side of the threshing device 5 After being cut to a suitable length by the waste cutter 235 provided on the rear, the paper is discharged to the lower rear side of the traveling machine body 1.

(1-2). Next, an overall structure of a common rail type diesel engine 70 will be described with reference mainly to FIGS. In the description of the diesel engine 70 in FIGS. 4 to 7, the intake manifold 73 installation side of the diesel engine 70 facing rearward with respect to the traveling machine body 1 is simply referred to as the rear side of the diesel engine 70. The exhaust manifold 71 installation side of the diesel engine 70 facing forward is simply referred to as the front side of the diesel engine 70.

  As shown in FIGS. 3 to 7, an exhaust manifold 71 is disposed on the front side surface of the cylinder head 72 in the diesel engine 70. An intake manifold 73 is disposed on the rear side of the cylinder head 72. The cylinder head 72 is mounted on a cylinder block 75 in which an engine output shaft 74 (crankshaft) and a piston (not shown) are built. The left and right tip ends of the engine output shaft 74 are protruded from both the left and right side surfaces of the cylinder block 75. A cooling fan 76 is provided on the right side surface of the cylinder block 75. A rotational force is transmitted from the right end side of the engine output shaft 74 to the cooling fan 76 via the V belt 77.

  As shown in FIGS. 3 to 7, a flywheel housing 78 is fixed to the left side surface of the cylinder block 75. A flywheel 79 is disposed in the flywheel housing 78. The flywheel 79 is pivotally supported on the left end side of the engine output shaft 74. The flywheel 79 is configured to rotate integrally with the engine output shaft 74. A drive unit such as a traveling crawler 2 as a traveling unit (high load working unit), a reaping device 3 or a threshing device 5 as a high load working unit, a grain discharge auger 8 as a low load working unit, and the like via a flywheel 79. Thus, the power of the diesel engine 70 is taken out.

  An oil pan 81 is arranged on the lower surface of the cylinder block 75. Engine leg mounting portions 82 are respectively provided on the left and right side surfaces of the cylinder block 75 and the left and right side surfaces of the flywheel housing 78. Each engine leg mounting portion 82 is bolted to an engine leg 83 having vibration-proof rubber. The diesel engine 70 is supported in an anti-vibration manner by an engine support chassis 84 formed integrally with the traveling machine body 1 through the engine legs 83. As is clear from the above description, the diesel engine 70 is formed below the driving cabin 10 such that the flywheel 79 is located on the center side of the traveling aircraft body 1 and the cooling fan 77 is located on the right side of the traveling aircraft body 1. Located in the engine room. That is, the diesel engine 70 is arranged so that the direction of the engine output shaft 74 extends in the left-right direction.

  As shown in FIGS. 3, 4, and 7, an air cleaner 88 is connected to the intake manifold 73 via an EGR device (exhaust gas recirculation device) 91 and a supercharging pipe 108. The EGR device 91 mixes the recirculated exhaust gas of the diesel engine 70 (EGR gas from the exhaust manifold 71) and fresh air (external air from the air cleaner) and supplies the mixture to the intake manifold 73. A recirculation exhaust gas pipe 95 connected to the exhaust manifold 71 via an EGR cooler 94, and an EGR valve 96 communicating the EGR main body case 92 with the recirculation exhaust gas pipe 95.

  While outside air is supplied into the EGR main body case 92, EGR gas (a part of the exhaust gas discharged from the exhaust manifold 71) is supplied from the exhaust manifold 71 into the EGR main body case 92 via the EGR valve 96. . After the outside air and the EGR gas from the exhaust manifold 71 are mixed in the EGR main body case 92, the mixed gas in the EGR main body case 92 is supplied to the intake manifold 73. That is, a part of the exhaust gas discharged from the diesel engine 70 to the exhaust manifold 71 is recirculated from the intake manifold 73 to the diesel engine 70, so that the maximum combustion temperature during high load operation decreases, NOx (nitrogen oxide) emissions are reduced.

  As shown in FIGS. 4 to 7, the turbocharger 100 is attached to the rear side surface of the cylinder head 72. The turbocharger 100 includes a turbine case 101 having a turbine wheel (not shown) and a compressor case 102 having a blower wheel (not shown). An exhaust manifold 71 is connected to the exhaust gas intake pipe 105 of the turbine case 101. A tail pipe 107 is connected to the exhaust gas discharge pipe 103 of the turbine case 101 via a diesel particulate filter 60 (hereinafter referred to as DPF) as a filter device. That is, the exhaust gas discharged from each cylinder of the diesel engine 70 to the exhaust manifold 71 is discharged to the outside from the tail pipe 107 via the turbocharger 100, the DPF 60, and the like.

  On the other hand, the air supply side of the air cleaner 88 is connected to the air supply side of the compressor case 102 via the air supply pipe 104. An intake manifold 73 is connected to the supply / discharge side of the compressor case 102 via a supercharging pipe 108. The intake side of the air cleaner 88 is connected to the precleaner 90 via the intake duct 89. That is, the outside air removed by the pre-cleaner 90 and the air cleaner 88 is sent from the compressor case 102 to the intake manifold 73 via the supercharging pipe 108 and supplied to each cylinder of the diesel engine 70.

  As shown in FIGS. 4 to 7, the DPF 60 as a filter device is for collecting particulate matter (PM) and the like in the exhaust gas, and is disposed above the exhaust manifold 71 in the cylinder head 72. ing. The DPF 60 of the embodiment has a shape that is long in the left-right direction parallel to the engine output shaft 74 in plan view. An exhaust gas intake side of the DPF 60 is connected to the exhaust gas discharge pipe 103 of the turbine case 101, and a tail pipe 107 is connected to the exhaust gas discharge side of the DPF 60.

  As shown in FIG. 8, a DPF 60 is a soot that is a filter body having a honeycomb structure and a diesel oxidation catalyst 64 such as platinum in a substantially cylindrical filter case 62, 63 built in a DPF casing 61 made of a heat-resistant metal material. The filter 65 is arranged in series and accommodated. The upper end side of the fixed leg 109 is fixed by welding to one end side (right side) in the longitudinal direction of the DPF casing 61. The lower end side of the fixed leg 109 is bolted to the front side of the cylinder head 72. That is, the DPF 60 described above is stably connected and supported above the exhaust manifold 71 by the fixed leg 109 and the exhaust gas discharge pipe 103 of the turbine case 101.

  The DPF casing 61 is provided with a pressure sensor 66 as an example of clogging detection means for detecting a clogged state of the DPF 60 (see FIG. 8). For example, the pressure sensor 66 may have a known structure using a piezoresistance effect. In this case, the pressure Ps (reference pressure value) on the upstream side of the soot filter 65 when particulate matter is not deposited on the soot filter 65 (when the DPF 60 is new) is stored in a ROM or the like of the fuel injection controller 311 described later. Pre-stored, the current pressure P at the same measurement location is detected by the pressure sensor 66, the difference ΔP between the reference pressure value Ps and the detected value P of the pressure sensor 66 is obtained, and the soot is based on the pressure difference ΔP. The particulate matter accumulation amount of the filter 65 is converted (estimated) (see FIG. 12). Note that pressure sensors may be arranged on the upstream and downstream sides of the DPF 60 with the soot filter 65 interposed therebetween, and the particulate matter accumulation amount of the soot filter 65 may be converted (estimated) from the difference between the detection values of the two. .

  In the above configuration, the exhaust gas of the diesel engine 70 flows from the exhaust gas discharge pipe 103 of the turbine case 101 into the space upstream of the diesel oxidation catalyst 64 in the DPF casing 61, and from the diesel oxidation catalyst 64 to the soot filter 65. In this order, it is purified. Particulate matter in the exhaust gas is collected at this stage without passing through the porous partition walls between the cells in the soot filter 65. Thereafter, exhaust gas that has passed through the diesel oxidation catalyst 64 and the soot filter 65 is discharged to the tail pipe 107.

When the exhaust gas passes through the diesel oxidation catalyst 64 and the soot filter 65, if the exhaust gas temperature exceeds a renewable temperature (for example, about 300 ° C.), the action of the diesel oxidation catalyst 64 causes NO ( Nitric oxide) oxidizes to unstable NO ₂ (nitrogen dioxide). And the particulate matter collection ability of the soot filter 65 is recovered by oxidizing and removing the particulate matter deposited on the soot filter 65 by O (oxygen) released when NO ₂ returns to NO ( Soot filter 65 is regenerated).

(1-3). Next, the fuel system structure of the common rail system 117 and the diesel engine 70 will be described with reference to FIGS. 3 to 7 and FIGS. 9 to 11. As shown in FIGS. 4 and 9, a fuel tank 118 is connected to each of the four cylinder injectors 115 provided in the diesel engine 70 via a fuel pump 116 and a common rail system 117. Each injector 115 has an electromagnetic switching control type fuel injection valve 119. The common rail system 117 includes a cylindrical common rail 120.

  As shown in FIGS. 4, 9 and 11, a fuel tank 118 is connected to the suction side of the fuel pump 116 via a fuel filter 121 and a low pressure pipe 122. The fuel in the fuel tank 118 is sucked into the fuel pump 116 via the fuel filter 121 and the low pressure pipe 122. On the other hand, the common rail 120 is connected to the discharge side of the fuel pump 116 via a high-pressure pipe 123. A high-pressure pipe connector 124 is provided in the middle of the cylindrical common rail 120 in the longitudinal direction, and the end of the high-pressure pipe 123 is connected to the high-pressure pipe connector 124 by screwing a high-pressure pipe connector nut 125.

  In addition, injectors 115 for four cylinders are connected to the common rail 120 via four fuel injection pipes 126, respectively. A fuel injection pipe connector 127 for four cylinders is provided in the longitudinal direction of the cylindrical common rail 120, and the end of the fuel injection pipe 126 is connected to the fuel injection pipe connector 127 by screwing a fuel injection pipe connector nut 128. .

  With the above configuration, the fuel in the fuel tank 118 is pumped to the common rail 120 by the fuel pump 116, and high-pressure fuel is stored in the common rail 120. Each fuel injection valve 119 is controlled to open and close, whereby high-pressure fuel in the common rail 120 is injected from each injector 115 to each cylinder of the diesel engine 70. That is, by electronically controlling each fuel injection valve 119, the injection pressure, injection timing, and injection period (injection amount) of the fuel supplied from each injector 115 can be controlled with high accuracy. Therefore, nitrogen oxides (NOx) discharged from the diesel engine 70 can be reduced, and noise vibration of the diesel engine 70 can be reduced.

  As shown in FIG. 11, a fuel pump 116 is connected to the fuel tank 118 via a pump fuel return pipe 129. A common rail fuel return pipe 131 is connected to the end of the cylindrical common rail 120 in the longitudinal direction via a return pipe connector 130 with a pressure adjusting valve that limits the pressure of fuel in the common rail 120. That is, surplus fuel in the fuel pump 116 and surplus fuel in the common rail 120 are recovered in the fuel tank 118 via the pump fuel return pipe 129 and the common rail fuel return pipe 131.

  Further, as shown in FIGS. 4 and 10, a fastening base 133 is integrally formed on an oil cooler housing 132 provided on one side of the cylinder block 75. Further, the fastening boss 134 is formed integrally with the common rail 120. A fastening boss 134 is fixed to the fastening base 133 by rail mounting bolts 135. The common rail 120 is detachably fastened to one side of the cylinder block 75 via an oil cooler housing 132. That is, the common rail 120 is provided on one side of the cylinder block 75. The common rail 120 is disposed in the vicinity of the corner portion of the intake manifold 73 obliquely below.

  As shown in FIGS. 4 and 10, the common rail 120 is juxtaposed below the intake manifold 73. The fuel injection pipe connector 127 disposed on the upper surface side of the common rail 120 is configured to tilt the common rail 120 so that the fuel injection pipe connector 127 is obliquely upward and outward. Accordingly, a part of the upper surface side of the common rail 120 is covered by the intake manifold 73. Therefore, even when a tool or the like is dropped from above toward the common rail 120 during assembly / disassembly work of the diesel engine 70, the intake manifold 73 Damage due to 120 collisions can be reduced. Further, a screwing operation of the fuel injection pipe connector nut 128 for connecting the fuel injection pipe 126 to the fuel injection pipe connector 127 can be easily executed. Assembling / disassembling workability such as piping of the fuel injection pipe 126 can be improved.

(1-4). Structure for Executing Fuel Injection Control Next, a structure for executing fuel injection control will be described with reference to FIG. The combine of the first embodiment is equipped with a fuel injection controller 311 that operates the fuel injection valve 119 of each cylinder in the diesel engine 70 as an example of a control means. The fuel injection controller 311 includes a CPU that executes various arithmetic processes and controls, a ROM as a storage unit that stores control programs and data, a RAM that temporarily stores control programs and data, an input / output interface, and the like It has.

  On the input side of the fuel injection controller 311, a rail pressure sensor 312 that detects the fuel pressure in the common rail 120, an electromagnetic clutch 313 that rotates or stops the fuel pump 116, and the engine speed of the diesel engine 70 (engine output shaft 74 Engine rotation sensor 314 for detecting the crank type camshaft position), an injection setting device 315 for detecting and setting the number of fuel injections of the injector 115 (the number of fuel injections during the fuel injection period of one stroke), and an accelerator lever or accelerator An accelerator sensor 316 that detects the operating position of an accelerator operating tool (not shown) such as a pedal, a turbo booster sensor 317 that detects the pressure of the turbocharger 100, and an intake air temperature sensor 318 that detects the intake air temperature of the intake manifold 73. And the temperature of the cooling water of the diesel engine 70 A cooling water temperature sensor 319 that output is connected.

  An electromagnetic solenoid of each fuel injection valve 119 for four cylinders is connected to the output side of the fuel injection controller 311. That is, the high-pressure fuel stored in the common rail 120 is configured to be injected from the fuel injection valve 119 in a plurality of times during one stroke while controlling the fuel injection pressure, the fuel injection timing or the fuel injection period. Yes. For this reason, complete combustion with reduced generation of nitrogen oxides and reduced generation of particulate matter (soot), carbon dioxide, and the like can be performed to improve fuel efficiency. When the accelerator operating tool is manually operated, the fuel injection controller 311 is supplied from each injector 115 by electronically controlling each fuel injection valve 119 so that the engine speed becomes the set speed set by the accelerator operating tool. Adjust the fuel. For this reason, the engine speed is held at a value corresponding to the operation position of the accelerator operating tool.

  As shown in FIG. 11, on the input side of the fuel injection controller 311, a work clutch sensor 331 that detects an on / off operation (driving or stopping of the threshing device 5) of the work clutch lever 18 as work system operation means, An operation position (forward / neutral / reverse) of a grain discharge sensor 332 for detecting whether or not the auger 8 is operated (whether or not a grain is discharged from the grain tank 7) and a main transmission lever 16 as a moving system operating means A potentiometer type shift sensor 333 for detecting, an exhaust temperature sensor 334 for detecting the exhaust gas temperature of the exhaust manifold 71, and a forced low speed for forcibly reducing the engine speed to a predetermined low speed (low idle speed). A forced low rotation switch 35 serving as a forced low rotation operation means for executing control, and a vehicle speed sensor 3 for detecting the vehicle speed (movement speed) of the traveling machine body 1 6, a pressure sensor 66 for detecting the clogging state of the DPF60 is connected.

  Here, the forced low rotation switch 35 is a return-type push switch (also referred to as a momentary switch), and the engine speed is forcibly decreased to the low idle speed by the first pressing operation, and the second pressing operation is performed. The engine speed is set to return from the low idle speed to the original speed before the decrease.

  Further, a notification device 337 as a notification means for issuing various alarms is electrically connected to the output side of the fuel injection controller 311. The notification device 337 is a lamp that performs visual notification according to the operation state of the combine, and various blinking data are stored in advance in storage means (ROM) of the fuel injection controller 311. The notification means is not limited to a visual notification lamp, but may be a buzzer, a sound device, or a display means such as a liquid crystal panel that displays characters, symbols, or the like.

  As an example of fuel injection control, the fuel injection controller 311 of the first embodiment performs forced low rotation control when the forced low rotation switch 35 is turned on (first pressing operation) regardless of whether or not forced regeneration control is necessary. Is executed preferentially, the execution of the forced regeneration control is prohibited, and the forced low rotation switch 35 is pushed again, or the main transmission lever 16 or the work clutch lever 18 or the like for the combine is operated, The forced low rotation control is configured to stop. In addition, when the fuel injection controller 311 stops the forced low rotation control, the clogged state in the DPF 60 reaches a preset state (a state in which the DPF 60 is clogged so as to reduce the output of the diesel engine 70). If so, the forced regeneration control is executed, and if the preset state has not been reached, the engine speed is returned from the low idle speed to the original speed before the decrease.

  Here, the forced low rotation control (one-touch decel control) is supplied from each injector 115 by electronically controlling each fuel injection valve 119 when the forced low rotation switch 35 is turned on (first pressing operation). By adjusting the fuel injection state (injection pressure, injection timing, injection period, etc.), the engine speed is automatically reduced to a low idle speed (the output of the diesel engine 70 is reduced). In the forced regeneration control, the diesel engine 70 is controlled by electronically controlling each fuel injection valve 119 based on detection information from the pressure sensor 66 and the exhaust temperature sensor 334 to adjust the injection state of the fuel supplied from each injector 115. The exhaust gas temperature is increased to increase the exhaust gas temperature, and the particulate matter in the DPF 60 (soot filter 65) is forcibly burned.

  With the above configuration, the forced regeneration control for increasing the output of the diesel engine 70 cannot be performed repeatedly during the execution of the forced low rotation control for decreasing the output of the diesel engine 70. For this reason, the two fuel injection controls (forced low-rotation control and forced regeneration control) that require conflicting operations with the diesel engine 70 can coexist and can be executed efficiently without overlapping each other. Therefore, it is possible to achieve both fuel economy saving and exhaust gas purification by the combine. It eliminates the operator's discomfort due to sudden changes in engine sound.

  Further, when the fuel injection controller 311 of the first embodiment operates the main shift lever 16 or the work clutch lever 18 for the combine to stop the forced low rotation control, the clogged state in the DPF 60 is set in advance. If it has reached (the state in which the DPF 60 is clogged to the extent that the output of the diesel engine 70 is reduced), the forced regeneration control is executed. On the other hand, if the preset state has not been reached, the engine speed is set to low idle rotation. Since it is configured to return to the original rotational speed before the decrease from the number, the operator has forgotten the return operation from the forced low rotation control (the second pressing operation of the forced low rotation switch in the first embodiment). However, the diesel engine can be operated simply by starting the combine and driving the working unit (threshing device 5 etc.). The output of the 0 would be easily ensured. Therefore, when returning from forced low-speed control, the combine engine is started at a low idle speed or the working unit is driven, so that the problem that the diesel engine 70 suddenly stops due to insufficient output or overload is ensured. Can be prevented.

  Further, the fuel injection controller 311 of the first embodiment is in a state in which the clogged state in the DPF 60 is set in advance during the execution of forced low rotation control (the state in which the DPF 60 is clogged so as to reduce the output of the diesel engine 70). In this case, the notification device 337 notifies that the forced regeneration of the DPF 60 (soot filter 65) is necessary. For this reason, even during forced low-rotation control in which forced regeneration control is prohibited, it is possible to grasp whether or not the DPF 60 (soot filter 65) is clogged and to alert the operator to the clogging of the DPF 60. Since forced low rotation control is executed, troubles such as high clogging of the DPF 60 and failure can be avoided.

(1-5). Description of Forced Low Rotation Control Next, an example of the above-described forced low rotation control will be described with reference to the flowchart of FIG. In the forced low rotation control of the first embodiment, when the forced low rotation switch 35 is pressed for the first time (step S1: YES), the neutral position operation (stop of the traveling machine body 1) of the main transmission lever 16 is performed at the vehicle speed. If detected by the sensor 336 (step S2: YES), forced low rotation control is executed (step S7) on condition that the threshing device 5 and the grain discharge auger 8 are stopped (steps S3 to S6). That is, the fuel injection state from each injector 115 is adjusted to reduce the engine speed of the diesel engine 70 to a low idle speed.

  Here, the stop of the threshing device 5 is determined by detecting the cutting operation of the work clutch lever 18 by the work clutch sensor 331 (step S3), and the stop of the grain discharge auger 8 is detected by the grain discharge sensor 332. (Step S5). If both are driven, the actuator is forcibly stopped by driving an actuator (not shown) (steps S4 and S6).

  Following step S7, the detected value Tex of the exhaust gas temperature is equal to or lower than a reproducible temperature (for example, about 300 ° C.), and the pressure difference ΔP between the detected value P of the pressure sensor 66 and the reference pressure value Ps is the limit pressure difference value ΔP0. It is determined whether or not this is the case (step S8). If the condition is not satisfied (step S8: NO), the particulate matter is not deposited so much on the soot filter 65, so that the second forced low rotation switch 35 is pressed or the main transmission lever is operated. 16 or the operation clutch lever 18 or the like is determined (step S9). If the condition is satisfied (step S9: YES), the forced low speed control is stopped, the fuel injection state from each injector 115 is adjusted, and the engine speed of the diesel engine 70 is changed from the low idle speed. The original rotational speed before the decrease is returned (step S10).

  Returning to step S8, if the above-described conditions are satisfied (step S8: YES), not only particulate matter is deposited on the soot filter 65, but also the soot filter 65 regeneration operation does not proceed. Then, after notifying the DPF 60 (soot filter 65) that the forced regeneration is necessary for a predetermined time by the notification device 337 (step S11), is the forced low rotation switch 35 pressed a second time? Alternatively, it is determined whether or not the main transmission lever 16 or the work clutch lever 18 has been operated (step S12). If the condition is satisfied (step S12: YES), the forced low rotation control is stopped and the forced regeneration control of the DPF 60 is executed (step S13). That is, the fuel injection state from each injector 115 is adjusted, the engine speed of the diesel engine 70 is increased to the set speed, the exhaust gas temperature is raised, and the particulate matter in the soot filter 65 is forcibly burned. Next, when the detected value Tex of the exhaust gas temperature exceeds the reproducible temperature and the pressure difference ΔP becomes less than the limit pressure difference value ΔP0 (step S14), the fuel injection state from each injector 115 is adjusted, and the diesel The engine speed of the engine 70 is returned from the set speed to the original speed before the decrease (step S15).

  As is clear from the above description, the engine 70 as a power source, the exhaust gas purifying filter device 60 disposed in the exhaust path of the engine 70, the clogged state of the filter device 60, and the driving of the engine 70 The engine device includes a control unit 311 that performs forced regeneration control of the filter device 60 based on the state (exhaust gas temperature), and the engine speed is reduced to a predetermined low speed (low idle speed). Compulsory low-rotation operation means 35 for executing forced low-rotation control for forcibly decreasing is provided, and the control means 311 controls the forced low-rotation operation means 35 regardless of whether or not the forced regeneration control is necessary. Since the forced low rotation control is preferentially executed when the turning operation is performed, execution of forced low rotation control for reducing the output of the engine 70 is performed. In, it is not carried out in duplicate forced regeneration control to raise the output of the engine 70. For this reason, the two fuel injection controls (forced low-rotation control and forced regeneration control) that require the engine 70 to operate in conflict with each other can coexist, and each control can be executed efficiently without overlapping. Therefore, there is an effect that it is possible to achieve both fuel economy saving and exhaust gas purification by the combine. In addition, there is an advantage that the operator feels uncomfortable due to a sudden change in engine sound.

  Further, the control means 311 stops the forced low rotation control when operating the moving system operating means 16 or the working system operating means 18 for the work machine on which the engine device is mounted. At this time, the filter device If the clogged state in 60 reaches a preset state (a state in which the filter device 60 is clogged so as to reduce the output of the engine 70), the forced regeneration control is executed, while the filter device 60 If the internal clogging state does not reach a preset state, the engine speed is returned to the original speed before the reduction, so that a return operation from the forced low speed control (first operation) In the embodiment, even if the operator forgets the second pressing operation of the forced low rotation operation means 35, the operation of starting the work machine or the working unit (threshing device 5 etc.) Only an operation for driving the, becomes possible to easily secure the output of the engine 70. Therefore, when returning from the forced low-speed control, the engine 70 is suddenly stopped due to insufficient output or overload by starting the working machine or driving the working unit at a low idle speed. There is an effect that defects can be reliably prevented.

  Further, the control means 311 is configured to perform the control means when the clogged state in the filter device 60 has reached a preset state (limit pressure difference value ΔP0 or more) during execution of the forced low rotation control. Since the notification means 337 connected to 311 is configured to notify, whether or not the filter device 60 is clogged even during execution of forced low-rotation control prohibiting forced regeneration control. And the operator can be alerted to the clogging of the filter device 60. Since the forced low-rotation control is executed, there is an advantage that troubles such as clogging of the filter device 60 and failure may be avoided.

(2). Second Embodiment FIGS. 13 to 16 show a second embodiment when the present invention is applied to a hydraulic excavator that is a working machine. In the description of the hydraulic excavator in FIGS. 13 and 14, the left side in the forward direction of the traveling machine body 1 is simply referred to as the left side, and the right side in the forward direction is also simply referred to as the right side. For convenience, these are used as a reference for the positional relationship between the upper and lower sides of the hydraulic excavator.

(2-1). Overall Structure of Hydraulic Excavator The overall structure of the hydraulic excavator that is the second embodiment of the working machine will be described with reference to FIGS. 13 and 14. As shown in FIGS. 13 and 14, the excavator 400 includes a crawler-type traveling device 402 having a pair of left and right traveling crawlers 403, and a revolving machine body 404 provided on the traveling device 402. The swivel body 404 is configured to be horizontally swivelable in all 360 ° directions by a turning hydraulic motor (not shown). An earthwork plate 405 for ground work is attached to the rear portion of the traveling device 402 so as to be movable up and down. A steering unit 406 and a diesel engine 70 are mounted on the left side of the revolving body 404. Since the configurations of the diesel engine 70 and its auxiliary machinery group are basically the same as those in the first embodiment, the same reference numerals as those in the first embodiment are used and detailed descriptions thereof are omitted. A working unit 410 having a boom 411 and a bucket 413 for excavation work is provided on the right side of the revolving machine body 404.

  The control unit 406 includes a control seat 408 on which an operator is seated, a travel lever 415 as a travel system operation unit that travels the left and right travel crawlers 403, an operation lever 416 that is a work system operation unit for the work unit 410, or A switch or the like is arranged. A boom cylinder 412 and a bucket cylinder 414 are arranged on a boom 411 that is a component of the working unit 410. A bucket 413 serving as an excavation attachment is pivotally attached to the tip of the boom 411 so as to be inserted and rotated. The boom cylinder 412 or the bucket cylinder 414 is operated to perform earthwork work (ground work such as grooving) by the bucket 413.

(2-2). Structure for Executing Fuel Injection Control Next, a structure for executing fuel injection control will be described with reference to FIG. The basic configuration of the fuel injection controller 311 mounted on the excavator 400 of the second embodiment is the same as that of the first embodiment. On the input side of the fuel injection controller 311, a rail pressure sensor 312 that detects the fuel pressure in the common rail 120, an electromagnetic clutch 313 that rotates or stops the fuel pump 116, and the engine speed of the diesel engine 70 (engine output shaft 74 Engine rotation sensor 314 for detecting the crank type camshaft position), an injection setting device 315 for detecting and setting the number of fuel injections of the injector 115 (the number of fuel injections during the fuel injection period of one stroke), and an accelerator lever or accelerator An accelerator sensor 316 that detects the operating position of an accelerator operating tool (not shown) such as a pedal, a turbo booster sensor 317 that detects the pressure of the turbocharger 100, and an intake air temperature sensor 318 that detects the intake air temperature of the intake manifold 73. And the temperature of the cooling water of the diesel engine 70 A cooling water temperature sensor 319 that output is connected.

  An electromagnetic solenoid of each fuel injection valve 119 for four cylinders is connected to the output side of the fuel injection controller 311. That is, the high-pressure fuel stored in the common rail 120 is configured to be injected from the fuel injection valve 119 in a plurality of times during one stroke while controlling the fuel injection pressure, the fuel injection timing or the fuel injection period. Yes.

  As shown in FIG. 15, on the input side of the fuel injection controller 311, a potentiometer-type travel sensor 432 that detects the operation position of the travel lever 415, a potentiometer-type lever sensor 433 that detects the operation position of the operation lever 416, As an exhaust temperature sensor 334 for detecting the exhaust gas temperature of the exhaust manifold 71 and forced low-rotation operation means for executing forced low-speed control for forcibly reducing the engine speed to a predetermined low speed (low idle speed). The forced low rotation switch 35, a vehicle speed sensor 336 for detecting the vehicle speed (moving speed) of the excavator 400, and a pressure sensor 66 for detecting the clogged state of the DPF 60 are connected to each other. In addition, a notification device 337 as a notification unit is electrically connected to the output side of the fuel injection controller 311. Various blinking data of the notification device 337 is stored in advance in storage means (ROM) of the fuel injection controller 311.

  The fuel injection controller 311 of the second embodiment also preferentially executes forced low rotation control when the forced low rotation switch 35 is turned on (first pressing operation) regardless of whether or not forced regeneration control is necessary. The forced low rotation control is prohibited, and the forced low rotation switch 35 is pushed again, or the forced low rotation control is stopped when the travel lever 415 or the operation lever 416 is operated. Yes. In addition, when the fuel injection controller 311 stops the forced low rotation control, the clogged state in the DPF 60 reaches a preset state (a state in which the DPF 60 is clogged so as to reduce the output of the diesel engine 70). If so, the forced regeneration control is executed, and if the preset state has not been reached, the engine speed is returned from the low idle speed to the original speed before the decrease.

(2-3). Description of Forced Low Rotation Control Next, an example of forced low rotation control in the second embodiment will be described with reference to the flowchart of FIG. In the forced low rotation control of the second embodiment, when the forced low rotation switch 35 is pressed for the first time (step S31: YES), the position fixed state of the travel lever 415 (stop of the travel device 402) is the travel sensor. If it is detected at 432 and the position fixing state of the operation lever 416 (stop of the boom 411 and the bucket 413) is detected by the lever sensor 433 (step S32), forced low rotation control is executed (step S32). S33). That is, the fuel injection state from each injector 115 is adjusted to reduce the engine speed of the diesel engine 70 to a low idle speed.

  Next, whether or not the detected value Tex of the exhaust gas temperature is equal to or lower than a reproducible temperature (for example, about 300 ° C.), and the pressure difference ΔP between the detected value P of the pressure sensor 66 and the reference pressure value Ps is greater than or equal to the limit pressure difference value ΔP0. Is determined (step S34). If the condition is not satisfied (step S34: NO), the particulate matter has not accumulated so much on the soot filter 65, so that the second forced low rotation switch 35 has been pressed or the travel lever 415 has been operated. Alternatively, it is determined whether or not the operation lever 416 or the like has been operated (step S35). If the condition is satisfied (step S35: YES), the forced low speed control is stopped, the fuel injection state from each injector 115 is adjusted, and the engine speed of the diesel engine 70 is changed from the low idle speed. The original rotational speed before the decrease is returned (step S36).

  Returning to step S34, if the above-described conditions are satisfied (step S34: YES), not only particulate matter is deposited on the soot filter 65, but also the soot filter 65 regeneration operation does not proceed. Then, after notifying the DPF 60 (soot filter 65) that the forced regeneration is necessary for a predetermined time (step S37), is the forced low rotation switch 35 pressed a second time? Alternatively, it is determined whether or not the travel lever 415 or the operation lever 416 is operated (step S38). If the condition is satisfied (step S38: YES), the forced low rotation control is stopped and the forced regeneration control of the DPF 60 is executed (step S39). That is, the fuel injection state from each injector 115 is adjusted, the engine speed of the diesel engine 70 is increased to the set speed, the exhaust gas temperature is raised, and the particulate matter in the soot filter 65 is forcibly burned. Next, when the detected value Tex of the exhaust gas temperature exceeds the reproducible temperature and the pressure difference ΔP becomes less than the limit pressure difference value ΔP0 (step S40), the fuel injection state from each injector 115 is adjusted, and the diesel The engine rotational speed of the engine 70 is returned from the set rotational speed to the original rotational speed before the decrease (step S41).

  As is apparent from the above description, the same effects as those of the first embodiment can be obtained even when configured as in the second embodiment.

(3). Third Embodiment FIGS. 17 to 23 show a third embodiment when the present invention is applied to a hydraulic excavator equipped with an electronic governor type diesel engine. Since the configuration of the hydraulic excavator 400 is basically the same as that of the second embodiment, the same reference numerals as those of the second embodiment are given and detailed description thereof is omitted.

(3-1). Overall Structure of Electronic Governor Type Diesel Engine The overall structure of an electronic governor type diesel engine 570 will be described with reference to FIGS. In the description of the diesel engine 570, the side on which the intake manifold 573 of the diesel engine 570 facing backward with respect to the hydraulic excavator 400 is simply referred to as the rear side of the diesel engine 570, and the diesel engine that also faces forward with respect to the hydraulic excavator 400. The exhaust manifold 571 installation side of 570 is simply referred to as the front side of the diesel engine 70.

  As shown in FIGS. 17 and 19, an exhaust manifold 571 is disposed on the front side surface of the cylinder head 572 of the diesel engine 570. An intake manifold 73 is disposed on the right side surface of the cylinder head 72. The cylinder head 72 is mounted on a cylinder block 575 having an engine output shaft 74 (crankshaft) and a piston (not shown). The left and right tip portions of the engine output shaft 574 protrude from the left and right side surfaces of the cylinder block 575, respectively. A cooling fan 576 is provided on the right side surface of the cylinder block 575. A rotational force is transmitted from the front end side of the engine output shaft 574 to the cooling fan 576 via the V belt 577.

  As shown in FIGS. 17, 18 and 20, a flywheel housing 578 is fixed to the left side surface of the cylinder block 575. A flywheel 579 is provided in the flywheel housing 578. A flywheel 579 is pivotally supported on the left end side of the engine output shaft 574. The working part of the hydraulic excavator is configured to take out the power of the diesel engine 570 via the flywheel 579.

  An oil pan 581 is disposed on the lower surface of the cylinder block 75. Lubricating oil is stored in the oil pan 581. Lubricating oil in the oil pan 581 is sucked by an oil pump 656 disposed in a portion near the right side surface in the cylinder block 575, and is passed through an oil filter 657 disposed on the right side surface of the cylinder block 75. 570 is supplied to each lubrication part. The lubricating oil supplied to each lubricating part is then returned to the oil pan 581. The oil pump 156 is configured to be driven by rotation of the engine output shaft 74.

  A fuel injection device 658 for supplying fuel to the combustion chamber in the cylinder block 575 is attached to the rear side surface of the cylinder block 575 above the oil filter 657 (below the intake manifold 573). The fuel injection device 658 includes an electronic governor and a fuel feed pump (both not shown) for adjusting the fuel injection amount. By driving the fuel feed pump, the fuel in the fuel tank is sent to the fuel injection device 658 via the fuel filter.

  A cooling water pump 659 for cooling water lubrication is disposed coaxially with the fan shaft 620 of the cooling fan 576 on the right side surface side of the cylinder block 575. The cooling water pump 659 is configured to be driven together with the cooling fan 576 by the rotation of the engine output shaft 574. Cooling water in a radiator (not shown) mounted on the hydraulic excavator is supplied to the cooling water pump 659 via a thermostat case 660 provided on the top of the cooling water pump 659. Then, by driving the cooling water pump 659, cooling water is supplied to a water cooling jacket (not shown) formed in the cylinder head 572 and the cylinder block 575 to cool the diesel engine 570. The cooling water that has contributed to the cooling of the diesel engine 570 is returned to the radiator. An alternator 161 is provided on the left side of the cooling water pump 159.

  Engine leg attachment portions 582 are provided on the front and rear side surfaces of the cylinder block 575 and the front and rear side surfaces of the flywheel housing 578, respectively. Each engine leg mounting portion 582 is bolted to an engine leg body 583 having vibration-proof rubber. The diesel engine 570 is supported in an anti-vibration manner on an engine support chassis 584 of a hydraulic excavator via each engine leg 583.

  As shown in FIG. 18, the inlet portion of the intake manifold 573 protrudes upward from the substantially central portion of the intake manifold 573. The inlet portion of the intake manifold 573 is connected to an air cleaner (not shown) via an EGR main body case 592 constituting an EGR device 591 (exhaust gas recirculation device). The fresh air (external air) sucked into the air cleaner is dust-removed and purified by the air cleaner, is sent to the intake manifold 573 via the EGR device 591, and is supplied to each cylinder of the diesel engine 570.

  As shown in FIGS. 18 and 19, the EGR device 591 includes an EGR main body case 592 that mixes a part of exhaust gas of the diesel engine 570 and fresh air and supplies the mixture to the intake manifold 573, and an EGR main body case 592 to the air cleaner. Are connected to the exhaust manifold 571 via an EGR cooler 594, and an EGR valve 596 is connected to the recirculation exhaust gas pipe 595 in the EGR main body case 592. ing.

  That is, the intake manifold 573 and the intake air intake throttle valve 593 for introducing fresh air are connected via the EGR main body case 592. The EGR main body case 592 communicates with the outlet side of the recirculated exhaust gas pipe 595 extending from the exhaust manifold 571. As shown in FIG. 19, the EGR main body case 592 is formed in a long cylindrical shape. The intake throttle valve 593 is bolted to one end of the EGR main body case 592 in the longitudinal direction. A downward opening end formed in a part of the EGR main body case 592 opposite to the intake throttle valve 593 is detachably bolted to the inlet of the intake manifold 573.

  In the third embodiment, the outlet side of the recirculation exhaust gas pipe 595 is connected to the EGR main body case 592 via the EGR valve 596. The EGR valve 596 adjusts the supply amount of EGR gas to the EGR main body case 592 by adjusting the opening degree. An opening end portion that protrudes obliquely downward from the outer peripheral surface of the EGR valve 596 is connected to a longitudinal midway portion of the EGR main body case 592. The inlet side of the recirculated exhaust gas pipe 595 is connected to the lower surface side of the exhaust manifold 571 via an EGR cooler 594.

  With the above configuration, fresh air (external air) is supplied from the air cleaner through the intake throttle member 593 into the EGR main body case 592, while EGR gas (from the exhaust manifold 571 through the EGR valve 596 to the EGR main body case 592 ( A part of the exhaust gas discharged from the exhaust manifold 571) is supplied. After fresh air from the air cleaner and EGR gas from the exhaust manifold 571 are mixed in the EGR main body case 592, the mixed gas in the EGR main body case 592 is supplied to the intake manifold 573. That is, a part of the exhaust gas discharged from the diesel engine 570 to the exhaust manifold 571 is recirculated from the intake manifold 573 to the diesel engine 570, whereby the maximum combustion temperature at the time of high load operation decreases, and the diesel engine 570 NOx (nitrogen oxide) emissions are reduced.

  The intake throttle valve 593 is for increasing the intake pressure of the diesel engine 570. That is, when particulate matter (soot) accumulates on the soot filter 65, the exhaust gas temperature from the diesel engine 570 is raised by increasing the intake pressure of the diesel engine 570 by controlling the operation of the intake throttle valve 593. Thus, the particulate matter (soot) deposited on the soot filter 65 burns. As a result, the particulate matter disappears and the soot filter 65 is regenerated. For this reason, the soot filter 65 can be regenerated by forcibly increasing the intake pressure by the intake throttle valve 593 even if the load is small and the temperature at which the exhaust gas tends to be low (particulate matter is easily deposited) is continuously performed. And the exhaust gas purification ability of the DPF 60 can be properly maintained. Further, a burner or the like for burning the soot deposited on the soot filter 65 becomes unnecessary.

  As shown in FIGS. 17 to 19, one end side of the fixed leg 109 is fixed to the DPF casing 61 by welding. The other end side of the fixed leg 109 is detachably fastened by a bolt 623 to a DPF attachment portion 622 formed on the upper surface of the flywheel housing 578. For this reason, the above-described DPF 60 is supported by the high-rigidity flywheel housing 578 via both fixed legs 109. Since the configuration of the DPF 60 is basically the same as that of the first and second embodiments, the same reference numerals as those of the first and second embodiments are assigned and detailed description thereof is omitted.

  As shown in FIG. 17, the outlet portion of the exhaust manifold 571 protrudes upward from the left end side of the exhaust manifold 571. The outlet portion of the exhaust manifold 571 is detachably connected to the exhaust inlet side of the DPF 60 via an exhaust throttle device 626 for adjusting the exhaust pressure of the diesel engine 570. Exhaust gas that has moved into the DPF 60 from the outlet of the exhaust manifold 571 is purified by the DPF 60, then moved from the exhaust discharge side to a tail pipe (not shown), and finally discharged outside the machine. Become.

(3-2). Structure for Executing Fuel Injection Control and its Control Mode Next, a structure for executing fuel injection control and its control mode will be described with reference to FIGS. In the DPF 60, in order to maintain the exhaust gas purification performance in an appropriate state, the exhaust gas temperature needs to be equal to or higher than a predetermined temperature (approximately about 300 ° C.). In this regard, the third embodiment is configured such that the exhaust gas temperature from the diesel engine 570 can be adjusted by using the exhaust throttle device 626.

  Similarly to the first and second embodiments, the electronic governor controller 611 as a control means mounted on the hydraulic excavator also turns on the forced low-rotation switch 35 regardless of whether or not forced regeneration control is necessary (the first press). Forcibly revolving control is preferentially executed and forced regeneration control is prohibited, and the forced low revolving switch 35 is pressed again, or the traveling lever 415 or the operating lever 416 is operated. Is configured to stop the forced low rotation control. In addition, when the electronic governor controller 611 stops the forced low rotation control, the clogged state in the DPF 60 reaches a preset state (a state in which the DPF 60 is clogged to the extent that the output of the diesel engine 70 is reduced). If so, the forced regeneration control is executed, and if the preset state has not been reached, the engine speed is returned from the low idle speed to the original speed before the decrease. The electronic governor controller 611 has a central processing unit (CPU), storage means, and the like (not shown).

  As shown in FIG. 22, the electronic governor controller 611 includes the fuel injection device 658 of the diesel engine 570, the injection amount detection sensor 666 for detecting the fuel injection amount from the fuel injection device 658, and the operation position of the travel lever 415. A potentiometer-type travel sensor 432 for detecting, a potentiometer-type lever sensor 433 for detecting the operation position of the operation lever 416, an exhaust temperature sensor 334 for detecting the exhaust gas temperature of the exhaust manifold 571, and an engine speed of a predetermined low level. A forced low-rotation switch 35 as forced low-rotation operation means for executing forced low-rotation control to forcibly reduce the rotational speed (low idle rotational speed), and a vehicle speed sensor 336 that detects the vehicle speed (moving speed) of the excavator 400. A pressure sensor 66 for detecting the clogged state of the DPF 60, and various warnings. And a motor driving circuit 668 for the exhaust throttle drive motor 667 capable of rotating in the forward and reverse directions, and an angle sensor 669 for detecting the valve opening / closing angle of the exhaust throttle device 626 are electrically connected to each other. It is connected. Note that the various audio data of the notification device 337 is stored in advance in the storage means of the electronic governor controller 611.

  In this case, as shown in the flowchart of FIG. 23, when the forced low rotation switch 35 is pressed for the first time (step S51: YES), the travel lever 415 is in a fixed position (the travel device 402 is stopped). If the sensor 432 detects that the operation lever 416 is in a fixed position (the boom 411, the bucket 413, etc. are stopped) (step S52), forced low rotation control is executed (step S52). Step S53). That is, the fuel injection state from the fuel injection device 658 is adjusted to reduce the engine speed of the diesel engine 70 to the low idle speed.

  Next, whether or not the detected value Tex of the exhaust gas temperature is equal to or lower than a reproducible temperature (for example, about 300 ° C.), and the pressure difference ΔP between the detected value P of the pressure sensor 66 and the reference pressure value Ps is greater than or equal to the limit pressure difference value ΔP0. Is determined (step S54). When the condition is not satisfied (step S54: NO), since the particulate matter is not so much accumulated on the soot filter 65, the second forced low rotation switch 35 is pressed or the travel lever 415 is operated. Alternatively, it is determined whether or not the operation lever 416 or the like has been operated (step S55). If the condition is satisfied (step S55: YES), the forced low speed control is stopped, the fuel injection state from the fuel injection device 658 is adjusted, and the engine speed of the diesel engine 70 is set to the low idle speed. To the original rotational speed before the decrease (step S56).

  Returning to step S54, if the above-described conditions are satisfied (step S54: YES), not only particulate matter is deposited on the soot filter 65, but also the soot filter 65 regeneration operation does not proceed. Then, after notifying the DPF 60 (the soot filter 65) that the forced regeneration is necessary for a predetermined time (step S57), is the forced low rotation switch 35 pressed a second time? Alternatively, it is determined whether or not the travel lever 415 or the operation lever 416 is operated (step S58). If the condition is satisfied (step S58: YES), the forced low speed control is stopped, the engine speed of the diesel engine 70 is returned to the original speed before the decrease, and then the forced regeneration control of the DPF 60 is performed. Execute (step S59). In this case, the intake throttle valve 593 is closed by the drive of the intake throttle drive motor 667. Then, the load on the diesel engine 570 increases, the output (fuel injection amount) of the diesel engine 570 increases to maintain the engine speed, and as a result, the exhaust gas temperature from the diesel engine 570 increases. Then, the particulate matter in the soot filter 65 is forcibly burned. Next, when the detected value Tex of the exhaust gas temperature exceeds the reproducible temperature and the pressure difference ΔP becomes less than the limit pressure difference value ΔP0 (step S60), the intake throttle valve 593 is opened by driving the intake throttle drive motor 667. The valve is operated to return the valve opening / closing angle of the intake throttle valve 593 to the original state before the closing operation (step S61). As a result, the load on the diesel engine 570 decreases, and the output (fuel injection amount) of the diesel engine 570 decreases in order to maintain the engine speed.

  As is apparent from the above description, the same effects as those of the first and second embodiments can be obtained even when configured as in the third embodiment.

(4). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the engine of the working machine to which the present invention is applied may be a common rail type or an electronic governor type. The configuration for forced regeneration control is not limited to the type that controls the fuel injection amount and the exhaust throttle device, but a dummy load using hydraulic equipment or the like is applied to the engine or the intake throttle is controlled. Also good. The point is that the exhaust gas temperature may be forcibly increased. Furthermore, the present invention can be applied not only to agricultural machines (combiners, tractors, etc.) and construction machines (hydraulic excavators, forklifts, etc.) but also to generators, ships, etc. The work machine is used as a general term for agricultural machines, construction machines, generators, ships, and the like. 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.

35 Forced low speed switch 60 DPF
64 Diesel oxidation catalyst 65 Soot filter 66 Pressure sensor 70 Common rail type diesel engine 117 Common rail system 311 Fuel injection controller 331 as control means Work clutch sensor 332 Grain discharge sensor 333 Shift sensor 334 Exhaust temperature sensor 336 Vehicle speed sensor 337 Audio device 432 Travel sensor 433 Lever sensor 570 Electronic governor type diesel engine 593 Intake throttle valve 611 Electronic governor controller 658 as control means Fuel injection device

Claims (3)

An engine as a power source, a filter device for purifying exhaust gas disposed in an exhaust path of the engine, a forced regeneration control of the filter device is executed based on a clogged state of the filter device and a driving state of the engine An engine device comprising a control means,
A forced low speed operation means for executing forced low speed control for forcibly reducing the engine speed to a predetermined low speed;
The control means is configured to preferentially execute the forced low rotation control when the forced low rotation operation means is turned on regardless of whether the forced regeneration control is necessary or not.
Engine equipment. The control means stops the forced low-rotation control when operating a moving system operating means or a working system operating means for a work machine on which the engine device is mounted. If the preset state has been reached, the forced regeneration control is executed. On the other hand, if the clogged state in the filter device has not reached the preset state, the original rotation before the engine speed is reduced. Configured to revert to a number,
The engine device according to claim 1. The control means is configured to notify the notifying means connected to the control means when the clogged state in the filter device reaches a preset state during execution of the forced low rotation control. Being
The engine device according to claim 1 or 2.

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