WO2010090069A1

WO2010090069A1 - Egr device and engine device with same

Info

Publication number: WO2010090069A1
Application number: PCT/JP2010/050544
Authority: WO
Inventors: 恭志小野寺
Original assignee: ヤンマー株式会社
Priority date: 2009-02-05
Filing date: 2010-01-19
Publication date: 2010-08-12

Abstract

An EGR device (91) for recirculating, as an EGR gas, a part of the exhaust gas, which is discharged from an exhaust manifold (71), to an intake manifold (73) is adapted so that the EGR device (91) can be used in common among different models of various working vehicles. In the EGR device (91), the intake manifold (73) and an intake throttle member (146) for introducing fresh air are connected through a relay conduit (145). The exit side of a recirculation conduit (148) extending from the exhaust manifold (71) is connected to the relay conduit (145). The relay conduit (145) is provided so that the direction thereof can be changed in multiple directions about the inlet section (73a) of the intake manifold (73). Thus, the direction of an intake system on the upstream side of the intake manifold (73) can be selected and changed without changing the structure of the relay conduit (145).

Description

EGR device and engine device provided with the same

The present invention relates to an EGR device and an engine device equipped with the EGR device. Specifically, an EGR (exhaust gas recirculation) device that recirculates a part of the exhaust gas discharged from the exhaust manifold to the intake manifold as EGR gas; The present invention relates to an engine device mounted on a work vehicle provided with the above.

Conventionally, as an exhaust gas countermeasure for diesel engines and the like, by providing an EGR device for exhaust gas recirculation that recirculates a part of the exhaust gas to the intake side, NOx (nitrogen oxidation in the exhaust gas is suppressed while keeping the combustion temperature low. A technique for reducing the amount of material) is known.

An example of this type of EGR apparatus is disclosed in Patent Document 1. In the EGR device of Patent Document 1, a reflux pipe branched from an exhaust manifold of a diesel engine is connected to an intake manifold. By supplying a part of the exhaust gas (EGR gas) to the intake manifold via the reflux line, the EGR gas and fresh air from the intake side are mixed. The mixed gas is introduced into each cylinder (inside the intake stroke) of the diesel engine.

In addition, an EGR valve for adjusting the EGR rate is provided in the reflux line. In this case, by adjusting the opening degree of the EGR valve according to the engine driving state such as the engine speed and the load, the supply amount of the EGR gas is adjusted so as to obtain an optimum EGR rate. As a result, the amount of NOx is reduced while maintaining a good combustion state of the diesel engine. The EGR rate means a value obtained by dividing the EGR gas amount by the sum of the EGR gas amount and the fresh air amount (= EGR gas amount / (EGR gas amount + new air amount)).

JP-A-8-261072

However, in the diesel engine equipped with the EGR device of Patent Document 1, since the return pipe is directly connected to the intake manifold, the EGR rate between the cylinders may be uneven. That is, when the return pipe is directly connected to the intake manifold, EGR gas and fresh air are mixed in the intake manifold. Then, depending on the shape of the intake manifold, the flow of EGR gas is uneven, and the mixed state with fresh air becomes uneven. If the mixed gas with unevenness is distributed to the cylinders as it is, the EGR gas is not sent evenly to the cylinders, and the EGR rate between the cylinders becomes non-uniform. If the EGR rate between the cylinders becomes uneven, a cylinder with a high EGR rate falls short of fresh air. When the EGR rate in the cylinder exceeds a predetermined value, the combustion state of the diesel engine is abruptly deteriorated and black smoke (smoke) is generated.

On the other hand, diesel engines are versatile and are used in various fields such as agricultural machines, construction machinery, and ships. The installation space for diesel engines varies depending on the target vehicle.

However, conventionally, when a diesel engine with an EGR device is mounted on a work vehicle, the layout of the reflux pipe and EGR valve is determined for each model. For example, the length and shape of the reflux pipe and the position of the EGR valve Etc. will be different for each model, and these EGR device-related members cannot be shared. For this reason, there existed a problem that component cost and by extension manufacturing cost increased. Further, the fact that the arrangement layout of the members related to the EGR device is different also has a problem that the EGR rate of the entire diesel engine also changes for each model.

Therefore, the present invention aims to improve the current situation as described above.

The present invention includes an EGR device and an engine device equipped with the EGR device. The invention according to claim 1 is an EGR device that recirculates a part of exhaust gas discharged from the exhaust manifold as EGR gas to the intake manifold in the EGR device, wherein the intake manifold and an intake throttle member for introducing fresh air are provided. Are connected via a relay line, and the outlet side of the reflux line extending from the exhaust manifold is connected to the relay line.

According to a second aspect of the present invention, in the EGR device according to the first aspect, the outlet side of the reflux pipe is connected to the relay pipe via an EGR valve member that adjusts the supply amount of the EGR gas. The intake throttle member, the relay pipe line, and the EGR valve member are unitized.

According to a third aspect of the present invention, in the EGR device according to the first aspect, the outlet side of the reflux pipe is connected to the relay pipe via an EGR valve member that adjusts the supply amount of the EGR gas. On the other hand, the inlet portion of the intake manifold protrudes upward, and the intake throttle member, the relay conduit, and the EGR valve member are exposed on the intake manifold, and the relay conduit and the EGR valve member Are arranged side by side.

According to a fourth aspect of the present invention, in the EGR device according to the third aspect, a plurality of temperature detection means for calculating an EGR rate of the mixed gas supplied to the intake manifold is provided in the relay pipe. It is.

The invention of claim 5 is an engine device comprising an engine having an intake manifold and an exhaust manifold, and the EGR device according to any one of claims 1 to 4.

According to a sixth aspect of the present invention, in the engine device according to the fifth aspect, the intake throttle member is positioned closer to the flywheel housing of the engine, and the relay conduit is connected to the output shaft of the engine in a plan view. It is arrange | positioned with the attitude | position extended in parallel.

According to a seventh aspect of the present invention, in the engine device according to the fifth aspect, the inlet portion of the intake manifold protrudes upward, and the intake throttle member, the relay pipe line, and the EGR valve member are located on the intake manifold. The cooling air from the cooling fan provided in the engine is hit.

The EGR device according to the present invention is an EGR device that recirculates a part of the exhaust gas discharged from the exhaust manifold to the intake manifold as EGR gas, and relays between the intake manifold and an intake throttle member for introducing fresh air Since the outlet side of the reflux line extending from the exhaust manifold is connected to the relay pipe, the fresh air and the EGR gas are mixed before being sent to the intake manifold. Will be. For this reason, the EGR gas can be widely dispersed in the mixed gas, and there is an effect that the variation (unevenness) in the mixed state in the mixed gas is reduced before being sent to the intake manifold. Further, the direction of the intake system upstream of the intake manifold can be selected / changed without changing the structure of the relay conduit. Therefore, variations in the layout of the intake system can be easily increased. Further, in the EGR device that recirculates a part of the exhaust gas discharged from the exhaust manifold to the intake manifold as EGR gas, the intake manifold and an intake throttle member for introducing fresh air are connected via a relay line. Since the outlet side of the reflux pipe extending from the exhaust manifold is connected to the relay pipe, the fresh air and the EGR gas are mixed before being sent to the intake manifold. For this reason, the EGR gas can be widely and uniformly dispersed in the mixed gas, and the variation (unevenness) in the mixed state in the mixed gas is reduced before being sent to the intake manifold, and the EGR gas is unevenly mixed in the mixed gas. Problems with mixing can be reduced.

According to a second aspect of the present invention, the outlet side of the reflux pipe is connected to the relay pipe via an EGR valve member that adjusts the supply amount of the EGR gas, and the intake throttle member and the relay pipe Since the passage and the EGR valve member are unitized, the intake throttle member, the relay pipe line, and the EGR valve member can be shared as a gas mixing unit even between different models. Therefore, each model equipped with the same type engine can be handled with a single gas mixing unit configuration, so that the EGR rate for each model equipped with the same type engine is suppressed from varying. This eliminates the trouble of confirming the test and applying for shipping. As a result, the manufacturing cost can be suppressed. It also becomes possible to reduce the assembly adjustment man-hours for performance matching between the EGR device and the engine.

According to the invention of claim 3, the outlet side of the reflux line is connected to the relay line via an EGR valve member that adjusts the supply amount of the EGR gas, while the inlet part of the intake manifold is The intake throttle member, the relay pipe line, and the EGR valve member are exposed on the intake manifold, and the relay pipe line and the EGR valve member are arranged side by side. Therefore, the influence of the gas mixing unit formed by combining the intake throttle member, the relay pipe line, and the EGR valve member can be reduced with respect to the total height of the engine on which the EGR device is mounted. Therefore, even if the engine incorporates the EGR device (gas mixing unit), the overall height can be kept as low as possible, and the EGR device (gas mixing unit) can be compactly arranged with respect to the engine.

According to the invention of claim 4, since a plurality of temperature detecting means for calculating the EGR rate of the mixed gas supplied to the intake manifold is provided in the relay pipe line, fresh air and EGR gas are: It will be mixed before being sent to the intake manifold. For this reason, EGR gas can be widely dispersed in the mixed gas, and uneven mixing of EGR gas in the mixed gas can be reduced before being sent to the intake manifold. A plurality of temperature detecting means are concentrated on the relay pipe. For this reason, the electrical system (the intake throttle member, the EGR valve member, and the temperature detecting means) of the EGR device around the intake manifold is compactly arranged, and the EGR device can be arranged compactly with respect to the engine. In addition, the wiring relation of the electrical system can be consolidated.

According to the invention of claim 5, since the EGR device according to any one of claims 1 to 4 is provided in an engine having an intake manifold and an exhaust manifold, a mixed gas with less unevenness is distributed to each cylinder of the engine. Thus, variation in the EGR rate between the cylinders can be suppressed. As a result, there is an effect that the amount of NOx can be efficiently reduced while suppressing the generation of black smoke and keeping the combustion state of the engine in good condition.

According to a sixth aspect of the present invention, the relay conduit is arranged in a posture extending in parallel with the output shaft of the engine in a plan view so that the intake throttle member is positioned closer to the flywheel housing of the engine. For example, when shortening the piping length of the intake system, or when reducing the number of parts of the intake system, an assembly of the intake throttle member and the relay pipe is provided by providing an air cleaner near the flywheel housing. This can be dealt with by the configuration (configuration of claim 6). That is, the piping of the intake system can be shortened and configured compactly. Manufacturing costs can be reduced by reducing the number of parts in the intake system.

According to the invention of claim 7, the inlet portion of the intake manifold protrudes upward, and the intake throttle member, the relay pipe line, and the EGR valve member are located on the intake manifold and are connected to the engine. Since the cooling air from the installed cooling fan is hit, the temperature of the gas mixing unit by cooling air, and by extension, the temperature of the mixed gas inside it can be suppressed, and the effect of reducing the NOx amount by the mixed gas is appropriate. There is an effect that it is easy to maintain a stable state.

It is a front view sectional view of DPF in an embodiment. It is the same external appearance bottom view. FIG. 2 is an exploded front sectional view of FIG. 1. It is a front view of a diesel engine. It is a rear view of a diesel engine. It is a top view of a diesel engine. It is a left view of a diesel engine. FIG. 7 is a plan view of a diesel engine in a case where the mounting direction of the EGR main body case is reversed by 180 ° from the state of FIG. 6. FIG. 7 is a plan view of a diesel engine when an EGR main body case is attached by 90 ° rotation from the state shown in FIG. 6. It is a front view of the diesel engine when the intake direction of the intake throttle member is set to the vertical direction. It is a side view of a backhoe. It is a top view of a backhoe. It is a side view of a forklift car. It is a top view of a forklift car. It is a functional block diagram of an engine controller. It is a flowchart which shows an example of EGR control. It is a conceptual diagram which shows the relationship between the temperature sensor and gas in an EGR main body case.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the exhaust gas inflow side is simply referred to as the left side, and the exhaust gas discharge side is simply referred to as the right side.

First, the overall structure of the exhaust gas purifying device will be described with reference to FIGS. As shown in FIGS. 1 to 3, a continuous regeneration type diesel particulate filter 1 (hereinafter referred to as DPF) is provided as an exhaust gas purification device. The DPF 1 is for physically collecting particulate matter (PM) and the like in the exhaust gas. The DPF 1 of the embodiment includes a diesel oxidation catalyst 2 such as platinum that generates nitrogen dioxide (NO2), and a soot filter 3 having a honeycomb structure that continuously oxidizes and removes the collected particulate matter (PM) at a relatively low temperature. Are arranged in series in the exhaust gas movement direction (from the left side to the right side in FIG. 1). The DPF 1 is configured so that the soot filter 3 is continuously regenerated. The DPF 1 can reduce carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas in addition to the removal of particulate matter (PM) in the exhaust gas.

Referring to FIGS. 1 to 3, the structure for attaching the diesel oxidation catalyst 2 will be described. As shown in FIGS. 1 to 3, a diesel oxidation catalyst 2 as a gas purification filter for purifying exhaust gas discharged from a diesel engine 70 described later is provided in a substantially cylindrical catalyst inner case 4 made of a heat-resistant metal material. ing. The catalyst inner case 4 is made of a heat resistant metal material and is provided in a substantially cylindrical catalyst outer case 5. That is, the catalyst inner case 4 is fitted on the outside of the diesel oxidation catalyst 2 via the mat-shaped ceramic fiber catalyst heat insulating material 6. Further, the catalyst outer case 5 is fitted on the outer side of the catalyst inner case 4 via a thin plate support 7 having an I-shaped end face. Note that the diesel oxidation catalyst 2 is protected by the catalyst heat insulating material 6. The stress (deformation force) of the catalyst outer case 5 transmitted to the catalyst inner case 4 is reduced by the thin plate support 7.

As shown in FIGS. 1 to 3, a disc-shaped left lid 8 is fixed to the left end of the catalyst inner case 4 and the catalyst outer case 5 by welding. A sensor connection plug 10 is fixed to the left lid body 8 through a seat plate body 9. The left end face 2a of the diesel oxidation catalyst 2 and the left lid 8 are opposed to each other with a predetermined distance L1 for gas inflow space. An exhaust gas inflow space 11 is formed between the left end face 2 a of the diesel oxidation catalyst 2 and the left lid 8. The sensor connection plug 10 is connected to an unillustrated inlet side exhaust gas pressure sensor, an inlet side exhaust gas temperature sensor, and the like.

1 and 3, an elliptical exhaust gas inlet 12 is opened at the left end of the catalyst inner case 4 and the catalyst outer case 5 in which the exhaust gas inflow space 11 is formed. The elliptical exhaust gas inlet 12 has a short diameter in the exhaust gas movement direction (center line direction of the cases 4 and 5) and a direction orthogonal to the exhaust gas movement direction (circumferential direction of the cases 4 and 5). It has a long diameter. A closing ring body 15 is fixed between the opening edge 13 of the catalyst inner case 4 and the opening edge 14 of the catalyst outer case 5 in a sandwiched manner. A gap between the opening edge 13 of the catalyst inner case 4 and the opening edge 14 of the catalyst outer case 5 is closed by the closing ring body 15. An exhaust ring 15 prevents the exhaust gas from flowing between the catalyst inner case 4 and the catalyst outer case 5.

As shown in FIGS. 1 and 3, an exhaust gas inlet pipe 16 is disposed on the outer surface of the catalyst outer case 5 in which the exhaust gas inlet 12 is formed. An exhaust connection flange body 17 is welded to a true circular opening end portion 16 a on the small diameter side of the exhaust gas inlet pipe 16. The exhaust connection flange body 17 is fastened to an exhaust throttle device 86 and an exhaust manifold 71 which will be described later via bolts 18. A large circular opening end 16 b on the large diameter side of the exhaust gas inlet pipe 16 is welded to the outer surface of the catalyst outer case 5. The exhaust gas inlet pipe 16 is formed in a divergent shape (a trumpet shape) from the small-diameter-side perfect circular opening end 16a toward the large-diameter-side perfect circular opening end 16b.

As shown in FIGS. 1 and 3, a large-diameter open end 16 b formed in a true circle is formed at the left end of the outer surface of the catalyst outer case 5, and an open edge 14 is formed by the exhaust gas inlet pipe 16. It is welded to cover it. In this case, the exhaust gas inlet pipe 16 (large-diameter-side opening end portion 16b) is offset with respect to the elliptical exhaust gas inlet 12, and is arranged offset to the exhaust gas movement downstream side (right side of the catalyst outer case 5). Has been. That is, the elliptical exhaust gas inlet 12 is offset to the exhaust gas movement upstream side (the left side of the catalyst outer case 5) with respect to the exhaust gas inlet pipe 16 (large-diameter side opening end portion 16b).

With the above configuration, the exhaust gas of the diesel engine 70 enters the exhaust gas inlet pipe 16 from the exhaust manifold 71, enters the exhaust gas inflow space 11 from the exhaust gas inlet pipe 16 through the exhaust gas inlet 12, and the diesel oxidation catalyst. 2 is supplied from the left end face 2a. Nitrogen dioxide (NO 2) is generated by the oxidation action of the diesel oxidation catalyst 2. When the DPF 1 is assembled to the diesel engine 70, the catalyst outer case 5 is fixed to the cylinder head 72 of the diesel engine 70 via a support bracket (not shown).

The mounting structure of the soot filter 3 will be described with reference to FIG. 1 and FIG. As shown in FIGS. 1 and 3, the soot filter 3 as a gas purification filter for purifying exhaust gas discharged from the diesel engine 70 is provided in a substantially cylindrical filter inner case 20 made of a heat-resistant metal material. The inner case 4 is made of a heat-resistant metal material and is provided in a substantially cylindrical filter outer case 21. That is, the filter inner case 20 is fitted on the outside of the soot filter 3 via the mat-shaped ceramic fiber filter heat insulating material 22. The soot filter 3 is protected by the filter heat insulating material 22.

1 and 3, the catalyst side flange 25 is welded to the end of the catalyst outer case 5 on the downstream side (right side) of the exhaust gas movement. The filter-side flange 26 is welded to the middle of the filter inner case 20 in the exhaust gas movement direction and the end of the filter outer case 21 on the upstream side (left side) of the exhaust gas movement. The catalyst side flange 25 and the filter side flange 26 are detachably fastened by bolts 27 and nuts 28. The diameter of the cylindrical catalyst inner case 4 and the diameter of the cylindrical filter inner case 20 are substantially the same. Further, the diameter of the cylindrical catalyst outer case 5 and the diameter of the cylindrical filter outer case 21 are substantially the same.

As shown in FIG. 1, in a state where the filter outer case 21 is connected to the catalyst outer case 5 via the catalyst side flange 25 and the filter side flange 26, the exhaust gas movement downstream side (right side) end of the catalyst inner case 4 is shown. The end portion on the upstream side (left side) of the exhaust gas movement of the filter inner case 20 faces the portion spaced apart by a fixed interval L2 for sensor attachment. In other words, the sensor mounting space 29 is formed between the exhaust gas movement downstream side (right side) end of the catalyst inner case 4 and the exhaust gas movement upstream side (left side) end of the filter inner case 20. A sensor connection plug 50 is fixed to the catalyst outer case 5 at the sensor mounting space 29 position. The sensor connection plug 50 is connected to a filter inlet side exhaust gas pressure sensor (not shown), a filter inlet side exhaust gas temperature sensor (thermistor), and the like.

As shown in FIG. 3, the cylindrical length L4 of the catalyst outer case 5 in the exhaust gas movement direction is longer than the cylindrical length L3 of the catalyst inner case 4 in the exhaust gas movement direction. The cylindrical length L6 of the filter outer case 21 in the exhaust gas movement direction is shorter than the cylindrical length L5 of the filter inner case 20 in the exhaust gas movement direction. A length (L2 + L3 + L5) obtained by adding the constant interval L2 of the sensor mounting space 29, the cylindrical length L3 of the catalyst inner case 4 and the cylindrical length L5 of the filter inner case 20 is the cylindrical length L4 of the catalyst outer case 5. And a length (L4 + L6) obtained by adding the cylindrical length L6 of the filter outer case 21 to be substantially equal to each other.

The exhaust gas movement upstream side (left side) end of the filter outer case 21 is connected to the exhaust gas movement upstream side (left side) end of the filter inner case 20 by a difference in length (L7 = L5-L6). Protruding. That is, when the filter outer case 21 is connected to the catalyst outer case 5, the exhaust gas movement upstream side (left side) end of the filter inner case 20 is the overlap dimension L7, and the exhaust gas movement downstream side of the catalyst outer case 5 (Right side) is interpolated.

With the above configuration, nitrogen dioxide (NO2) generated by the oxidation action of the diesel oxidation catalyst 2 is supplied to the soot filter 3 from the left end face 3a. The collected particulate matter (PM) in the exhaust gas of the diesel engine 70 collected by the soot filter 3 is continuously oxidized and removed at a relatively low temperature by nitrogen dioxide (NO2). In addition to the removal of particulate matter (PM) in the exhaust gas of the diesel engine 70, carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas of the diesel engine 70 are reduced.

As described above, the diesel oxidation catalyst 2 and the soot filter 3 are provided as gas purification filters for purifying the exhaust gas discharged from the engine. However, instead of the diesel oxidation catalyst 2 and the soot filter 3, urea (reducing agent) is used. NOx selective reduction catalyst (NOx removal catalyst) for reducing nitrogen oxide (NOx) in the exhaust gas of the engine 70 by ammonia (NH3) generated by the addition of)) and residual ammonia discharged from the NOx selective reduction catalyst You may provide the ammonia removal catalyst to remove.

As described above, when a NOx selective reduction catalyst (NOx removal catalyst) is provided in the catalyst inner case 4 and an ammonia removal catalyst is provided in the filter inner case 20 as a gas purification filter, nitrogen oxidation in the exhaust gas exhausted by the engine is performed. The substance (NOx) is reduced and can be discharged as harmless nitrogen gas (N2).

The mounting structure of the silencer 30 will be described with reference to FIGS. As shown in FIGS. 1 to 3, the silencer 30 for attenuating the exhaust gas sound discharged from the diesel engine 70 includes a substantially cylindrical silencer inner case 31 made of a heat resistant metal material and a substantially cylindrical shape made of a heat resistant metal material. The sound-absorbing outer case 32, and the sound-absorbing inner case 31 and the disc-shaped right-side cover 33 fixed to the right end of the sound-absorbing outer case 32 by welding. A silencer inner case 31 is provided in the silencer outer case 32. The diameter size of the cylindrical catalyst inner case 4, the diameter size of the cylindrical filter inner case 20, and the cylindrical sound deadening inner case 31 are substantially the same size. Further, the diameter of the cylindrical catalyst outer case 5, the diameter of the cylindrical filter outer case 21, and the cylindrical silencing outer case 32 are substantially the same.

An exhaust gas outlet pipe 34 is passed through the silencer inner case 31 and the silencer outer case 32. One end side of the exhaust gas outlet pipe 34 is closed by an outlet lid 35. A number of exhaust holes (not shown) are formed in the entire exhaust gas outlet pipe 34 inside the silencer inner case 31. The interior of the muffler inner case 31 communicates with the exhaust gas outlet pipe 34 through the numerous exhaust holes described above. A tail pipe 135 and an existing silencing member (not shown) to be described later are connected to the other end side of the exhaust gas outlet pipe 34.

In addition, the inside of the muffling inner case 31 is communicated between the muffling inner case 31 and the muffling outer case 32 through a number of muffler holes (not shown). The space between the silencer inner case 31 and the silencer outer case 32 is closed by the right lid 33 or the like. A ceramic fiber silencer (not shown) is filled between the silencer inner case 31 and the silencer outer case 32. The end of the silencing inner case 31 on the upstream side (left side) of the exhaust gas movement is connected to the end of the silencing outer case 32 on the upstream side (left side) of the exhaust gas movement via a thin plate support (not shown). Yes.

With the above configuration, exhaust gas is discharged from the muffler inner case 31 through the exhaust gas outlet pipe 34. Further, in the silencer inner case 31, exhaust gas sound (mainly high frequency band sound) is absorbed by the silencer material from a large number of silencer holes. Therefore, the noise of the exhaust gas discharged from the outlet side of the exhaust gas outlet pipe 34 is attenuated.

1 and 3, the filter side outlet flange 40 is welded to the exhaust gas movement downstream side (right side) ends of the filter inner case 20 and the filter outer case 21. The silencer flange 41 is welded to the exhaust gas movement upstream side (left side) of the silencer outer case 32. The filter side outlet flange 40 and the silencer side flange 41 are detachably fastened by bolts 42 and nuts 43. A sensor connection plug 44 is fixed to the filter inner case 20 and the filter outer case 21. The sensor connection plug 44 is connected to an unillustrated outlet side exhaust gas pressure sensor, an outlet side exhaust gas temperature sensor (thermistor) and the like.

Next, a structure in which the DPF 1 and the EGR device 91 (details will be described later) are provided in the diesel engine 70 will be described mainly with reference to FIGS. As shown in FIGS. 4 to 7, an exhaust manifold 71 is disposed on the front side surface of the cylinder head 72 of 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 having an engine output shaft 74 (crank shaft, see FIG. 7) and a piston (not shown). The left and right ends of the engine output shaft 74 are protruded from 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. The 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.

4 to 7, a flywheel housing 78 is fixed to the left side surface of the cylinder block 75. A flywheel 79 is provided in the flywheel housing 78. A flywheel 79 is pivotally supported on the left end side of the engine output shaft 74. The power of the diesel engine 70 is extracted via a flywheel 79 to operating parts such as a backhoe 100 and a forklift car 120 described later.

Further, an oil pan 95 is disposed on the lower surface of the cylinder block 75. Engine leg mounting portions 96 are provided on the front and rear side surfaces of the cylinder block 75 and the front and rear side surfaces of the flywheel housing 78, respectively. Each engine leg mounting portion 96 is bolted to an engine leg body 97 having vibration-proof rubber. The diesel engine 70 is supported in an anti-vibration manner on an engine mounting chassis 81 such as a work vehicle (backhoe 100, forklift car 120) via each engine leg 97.

As shown in FIG. 5, the inlet portion 73 a of the intake manifold 73 protrudes upward from a substantially central portion of the intake manifold 73. The inlet portion 73a of the intake manifold 73 is connected to an air cleaner (not shown) via an EGR device 91 (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 73 via the EGR device 91, and is supplied to each cylinder of the diesel engine 70.

As shown in FIGS. 5 and 6, the EGR device 91 mixes a part of exhaust gas of the diesel engine 70 (EGR gas from the exhaust manifold 71) and fresh air (external air from the air cleaner 88) to intake air. An EGR main body case (collector) 145 to be supplied to the manifold 73, an intake throttle member 146 for communicating the EGR main body case 145 with an air cleaner, and a recirculation exhaust as a return line connected to the exhaust manifold 71 via an EGR cooler 147 A gas pipe 148 and an EGR valve member 149 that allows the EGR main body case 145 to communicate with the recirculated exhaust gas pipe 148 are provided.

That is, the intake manifold 73 and the intake air intake throttle member 146 are connected via the EGR main body case 145. The EGR main body case 145 communicates with the outlet side of the recirculated exhaust gas pipe 148 extending from the exhaust manifold 71. As shown in FIG. 6, the EGR main body case 145 is formed in a long cylindrical shape. The intake throttle member 146 is bolted to one end of the EGR main body case 145 in the longitudinal direction. A downward opening end 145 a formed at a portion of the EGR main body case 145 opposite to the intake throttle member 146 is fastened to the inlet 73 a of the intake manifold 73 by a bolt 150 so as to be detachable.

As shown in FIG. 6, the EGR main body case 145 is provided with three temperature sensors 151 to 153 as temperature detecting means. A fresh air temperature sensor 151 that detects the temperature of fresh air from the air cleaner is disposed in a portion of the EGR main body case 145 near the intake throttle member 146. An EGR gas temperature sensor 152 that detects the temperature of the EGR gas from the exhaust manifold 71 is disposed near the EGR valve member 149 (recirculation exhaust gas pipe 148). A mixed gas temperature sensor 153 that detects the temperature of the mixed gas is disposed at a portion of the intake manifold 73 near the inlet 73a. The temperature sensors 151 to 153 are used for obtaining the EGR rate of the mixed gas. Here, the EGR rate means a value obtained by dividing the EGR gas amount by the sum of the EGR gas amount and the fresh air amount (= EGR gas amount / (EGR gas amount + new air amount)).

In the embodiment, the outlet side of the recirculation exhaust gas pipe 148 is connected to the EGR main body case 145 via the EGR valve member 149. The EGR valve member 149 adjusts the supply amount of EGR gas to the EGR main body case 145 by adjusting the opening degree of an EGR valve (not shown) in the EGR valve member 149. The outer shape of the EGR valve member 149 is formed in a long cylindrical shape, similar to the EGR main body case 145. The EGR main body case 145 and the EGR valve member 149 are arranged side by side. An opening end projecting obliquely downward from the outer peripheral surface of the EGR valve member 149 is connected to a longitudinal midway portion of the EGR main body case 145. The inlet side of the recirculated exhaust gas pipe 148 is connected to the lower surface side of the exhaust manifold 73 via an EGR cooler 147.

As shown in FIGS. 5 and 6, the intake throttle member 146 and the EGR valve member 149 are assembled in a common EGR main body case 145. In other words, the intake throttle member 146, the EGR main body case 145, and the EGR valve member 149 are unitized as one member. The intake throttle member 146, the EGR main body case 145, and the EGR valve member 149 are positioned (exposed) on the intake manifold 73 so that the cooling air from the cooling fan 76 strikes these

members

145, 146, and 149. It is configured.

With the above configuration, fresh air (external air) is supplied from the air cleaner through the intake throttle member 146 into the EGR main body case 145, while EGR gas (from the exhaust manifold 71 to the EGR main body case 145 through the EGR valve 149 is A part of the exhaust gas discharged from the exhaust manifold 71 is supplied. After fresh air from the air cleaner and EGR gas from the exhaust manifold 71 are mixed in the EGR main body case 145, the mixed gas in the EGR main body case 145 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 at the time of high load operation is lowered. NOx (nitrogen oxide) emissions are reduced.

As shown in FIGS. 4 to 7, the DPF 1 according to the embodiment has a long shape along the engine output shaft 74 and is arranged close to the exhaust manifold 71 on the cylinder head 72. Further, the exhaust gas inlet pipe 16 and the exhaust gas outlet pipe 34 are arranged on the left and right sides of the DPF 1 at one end in the longitudinal direction and the other end in the longitudinal direction.

As shown in FIG. 4, the outlet 71 a of the exhaust manifold 71 protrudes upward from the left end side of the exhaust manifold 71. An exhaust gas inlet pipe 16 of the DPF 1 is detachably connected to the outlet portion 71a of the exhaust manifold 71 via an exhaust throttle device 86 for adjusting the exhaust pressure of the diesel engine 70. In the embodiment, the exhaust connection flange body 17 of the exhaust gas inlet pipe 16 is fastened to the exhaust throttle device 86 and thus the exhaust manifold 71 via the bolt 18. For this reason, the above-described DPF 1 is supported by the highly rigid exhaust manifold 71 via the exhaust throttle device 86.

The exhaust throttle device 86 is for regenerating the soot filter 3. That is, when soot is deposited on the soot filter 3, the exhaust gas temperature from the diesel engine 70 is increased by increasing the exhaust pressure of the diesel engine 70 by controlling the exhaust throttle device 86. The soot accumulated on the soot filter 3 burns. As a result, the soot disappears and the soot filter 3 is regenerated.

Therefore, the soot filter 3 can be regenerated by forcibly increasing the exhaust pressure by the exhaust throttling device 86 even if the work with a small load and the temperature of the exhaust gas that tends to be low (the work that tends to accumulate soot) is continued. Can maintain the exhaust gas purification ability of Further, a burner or the like for burning the soot deposited on the soot filter 3 becomes unnecessary.

The exhaust gas that has moved from the outlet portion 71a of the exhaust manifold 71 into the DPF 1 through the exhaust gas inlet pipe 16 is purified by the DPF 1 and then moved from the exhaust gas outlet pipe 34 to the tail pipe (not shown). Finally, it will be discharged out of the machine.

As is clear from the above configuration, according to the EGR device 91 of the embodiment, the intake manifold 73 and the intake air intake throttle member 146 are connected via the EGR main body case 145, and are connected to the EGR main body case 145. Since the outlet side of the recirculation exhaust gas pipe 148 extending from the exhaust manifold 71 communicates, the fresh air and the EGR gas are mixed before being sent to the intake manifold 73. For this reason, the EGR gas can be widely dispersed in the mixed gas, and the variation (unevenness) in the mixed state in the mixed gas is reduced before being sent to the intake manifold 73. Therefore, a mixed gas with little unevenness can be distributed to each cylinder of the diesel engine 70, and variations in the EGR rate between the cylinders can be suppressed. As a result, the amount of NOx can be efficiently reduced while suppressing the generation of black smoke and keeping the combustion state of the diesel engine 70 in good condition.

In addition, since the intake throttle member 146, the EGR main body case 145, and the EGR valve member 149 are unitized as one member, they are different models of various work vehicles (for example, the backhoe 100 and the forklift car 120). However, these

members

145, 146 and 149 can be shared as a gas mixing unit. Therefore, each model equipped with the same type of diesel engine 70 can be dealt with by a single gas mixing unit configuration, so that the EGR rate for each model equipped with the same type of diesel engine 70 is suppressed from varying. Therefore, it is possible to omit the trouble of confirming the test and applying for shipping for each model. As a result, the manufacturing cost can be suppressed. It is also possible to reduce the assembly adjustment man-hours for performance matching between the EGR device 91 and the diesel engine 70.

Further, the intake throttle member 146, the EGR main body case 145, and the EGR valve member 149 are positioned (exposed) on the intake manifold 73 so that the cooling air from the cooling fan 76 strikes these

members

145, 146, and 149. Therefore, it is possible to suppress an increase in the temperature of the gas mixing unit due to the cooling air, and hence the mixed gas temperature therein, and to easily maintain the NOx reduction effect by the mixed gas in an appropriate state. In addition, the cooling performance of the EGR cooler 147 can be reduced by the amount by which the cooling air from the cooling fan 76 can suppress the rise of the gas mixing unit and thus the temperature of the mixed gas inside the unit. Become.

Moreover, the inlet portion 73a of the intake manifold 73 protrudes upward from the substantially central portion of the intake manifold 73, and the intake throttle member 146, the EGR main body case 145, and the EGR valve member 149 are positioned on the intake manifold 73 ( Since the EGR main body case 145 and the EGR valve member 149 are arranged side by side with each other, the influence of the

gas mixing units

145, 146, and 149 on the overall height of the diesel engine 70 can be reduced. . Therefore, even if the diesel engine 70 incorporates the EGR device 91 (

gas mixing units

145, 146, 149), the overall height can be kept as low as possible. 146, 149 can be arranged compactly.

In the embodiment, three temperature sensors 151 to 153 are attached to the EGR main body case 145 as temperature detection means used for obtaining the EGR rate of the mixed gas, and the temperature detection means are centrally arranged on the EGR main body case 145. As a result, the electrical system around the intake manifold 73 (the intake throttle member 146, the EGR valve member 149, and the temperature sensors 151 to 153) is gathered in a compact manner. In addition, the wiring relations of these electrical systems can be consolidated.

Referring to FIGS. 6, 8 and 9, the manner of changing the mounting direction of the EGR main body case 145 will be described. The EGR main body case 145 is provided so that the mounting direction can be changed in a plurality of directions around the inlet portion 73 a in the intake manifold 73. In the embodiment, even when the mounting direction of the EGR main body case 145 is changed in each of the three directions where the intake throttle member 146 is located on the left and right and the rear side, the downward opening end portion 145a of the EGR main body case 145 is provided at the inlet of the intake manifold 73. The positional relationship of the insertion hole of the downward opening end part 145a and the entrance part 73a is set so that the bolt 150 can be fastened to the part 73a.

FIG. 6 shows an example in which the EGR main body case 145 is arranged in a posture extending parallel to the engine output shaft 74 in a plan view so that the intake throttle member 146 is positioned closer to the flywheel housing 78 of the diesel engine 70. Show.

FIG. 8 shows an example in which the intake throttle member 146 is positioned on the left side by reversing the mounting direction of the EGR main body case 145 with respect to the intake manifold 73 from the state of FIG. That is, the EGR main body case 145 is arranged in a posture extending in parallel with the engine output shaft 74 in a plan view so that the intake throttle member 146 is positioned closer to the cooling fan 76.

FIG. 9 shows an example where the mounting direction of the EGR main body case 145 with respect to the intake manifold 73 is rotated by 90 ° from the state of FIG. 6 and the intake throttle member 146 is positioned on the rear side. That is, the EGR main body case 145 is arranged in a posture extending in a direction orthogonal to the engine output shaft 74 in plan view so that the intake throttle member 146 is separated from the intake manifold 73.

With the above configuration, the direction of the intake system upstream of the intake manifold 73 can be selected / changed without changing the structure of the EGR main body case 145, and variations in the layout of the intake system can be easily increased. For example, when shortening the piping length of the intake system or reducing the number of parts, if there is an air cleaner near the flywheel housing 78, the configuration of FIG. 6 may be adopted, and there is an air cleaner near the cooling fan 76. In that case, the configuration of FIG. 8 may be employed. When there is an air cleaner away from the intake manifold 73, the configuration of FIG. 9 may be employed. 6, 8, and 9, it is necessary to replace the recirculated exhaust gas pipe 148 with a length and shape corresponding to the mounting direction of the EGR body case 145.

Referring to FIG. 5 and FIG. 10, the manner of changing the mounting direction of the intake throttle member 146 will be described. In the embodiment, whether the intake throttle member 146 is directly attached to one end side in the longitudinal direction of the EGR main body case 145 (see FIG. 5) or attached via a spacer 154 (see FIG. 10), the EGR main body case 145 is attached. The mounting direction of the intake throttle member 146 can be changed. For this reason, the intake direction of the intake throttle member 146 can be set to the left-right direction along the intake direction of the EGR main body case 145, or the vertical direction intersecting the intake direction of the EGR main body case 145.

FIG. 10 shows an example in which the intake throttle member 146 is attached to one end side in the longitudinal direction of the EGR main body case 145 via a spacer 154 so that the intake direction of the intake throttle member 146 is set from top to bottom. Yes. The spacer 154 is formed in an L-shaped cylinder. One opening end of the spacer 154 is bolted to one end in the longitudinal direction of the EGR main body case 145, and the other opening end is bolted to the intake throttle member 146, whereby the intake throttle member 146 is in the intake direction. However, the vertical direction intersects the intake direction of the EGR main body case 145.

With this configuration, since the direction of the intake system further upstream than the intake throttle member 146 can be selected and changed, coupled with the change in the mounting direction of the EGR main body case 145, the layout variation of the intake system has been dramatically improved. It can be increased. For example, when shortening the piping length of the intake system or reducing the number of parts, when the air cleaner is above the diesel engine 70, it is preferable to adopt the configuration of FIG.

Next, the configuration for executing EGR control in the diesel engine 70 shown in FIGS. 4 to 7 and an example of the control mode will be described with reference to FIGS.

The engine controller 140 as a control means for controlling the driving of the diesel engine 70, in addition to the CPU 141 that executes various arithmetic processes and controls, the ROM 142 for storing control programs and data, and the control programs and data are temporarily stored. A RAM 143, an input / output interface, and the like. The engine controller 140 includes three temperature sensors 151 to 153 as temperature detecting means, a rotational speed sensor 157 for detecting the rotational speed Ne of the diesel engine 70, a load sensor 158 for detecting the load L of the diesel engine 70, and the like. Connected.

As described above, of the three temperature sensors 151 to 153, the fresh air temperature sensor 151 detects the temperature T1 of fresh air supplied from the air cleaner, and the EGR gas temperature sensor 152 includes the EGR gas from the exhaust manifold 71. The temperature T2 of the gas is detected. The mixed gas temperature sensor 153 detects the temperature T3 of the mixed gas mixed in the EGR main body. Note that the load sensor 158 of the embodiment employs a rack position sensor that detects a fuel supply amount from a rack position of a fuel injection pump with an electronic governor (not shown) that is a fuel supply unit. The engine load L may be calculated directly from the fuel supply amount, or may be obtained from the deviation between the target engine speed and the actual engine speed.

The engine controller 140 of the embodiment calculates the EGR rate of the mixed gas based on the detection information of the sensors 151 to 153, 157, and 158 when the diesel engine 70 is driven, and the EGR valve member 149 of the EGR valve member 149 is calculated according to the EGR rate. An EGR control for adjusting the opening degree is executed.

In this case, as shown in the flowchart of FIG. 16, first, the engine speed Ne, the engine load L, the fresh air temperature T1, the EGR gas temperature T2, and the mixed gas temperature T3 are read (step S100). Next, the values of the engine speed Ne and the engine load L are substituted into the EGR valve opening map f (Ne, L) to calculate the reference EGR opening EGR_s (step S200). Here, the EGR valve opening map f (Ne, L) is a two-dimensional map showing the relationship between the engine speed Ne, the engine load L, and the reference EGR opening EGR_s, and is stored in advance in the ROM 142 of the engine controller 140 or the like. It is remembered.

Next, using the engine speed Ne detected (sampled) every predetermined time, the engine load L, the fresh air temperature T1, the EGR gas temperature T2, and the mixed gas temperature T3, the latest sampling multiple times (for example, A simple moving average for 10 times is calculated (step S300). The engine speed Ne, the engine load L, the fresh air temperature T1, the EGR gas temperature T2, and the mixed gas temperature T3 described in the following steps are all assumed to be simple moving average values. In this way, an appropriate index EGR rate can be calculated even when the driving state of the diesel engine 70 is in a transient state.

Next, the index EGR rate EGR_t is calculated based on the fresh air temperature T1, the EGR gas temperature T2, and the mixed gas temperature T3, which are simple moving average values (step S400). Here, the index EGR rate EGR_t will be described in detail with reference to FIG. In the EGR main body case 145, the fresh air (external air) with the fresh air temperature T1 and the flow rate m1 and the EGR gas with the EGR gas temperature T2 and the flow rate m2 merge to form a mixed gas with the mixed gas temperature T3 and the flow rate m3. . The EGR rate (%) refers to the ratio of EGR gas in the mixed gas, and is represented by the following (Formula 1).

EGR rate (%) = m1 / (m1 + m2) × 100 (Equation 1)
Moreover, as shown in the following (Formula 2), the amount of heat of fresh air and EGR gas is equal to the amount of heat of mixed gas. Cp is the constant pressure molar specific heat of fresh air, and Cp ′ is the constant pressure molar specific heat of EGR gas.

m1Cp (T3-T1) = m2Cp ′ (T2-T3) (Equation 2)
Then, it is approximated that the constant pressure molar specific heat Cp of fresh air and the constant pressure molar specific heat Cp ′ of EGR gas are equal, and substituting (Equation 1) into (Equation 2), the index EGR as shown in The rate EGR_t is obtained.

EGR_t (%) = (T3−T1) / (T2−T1) × 100 (Equation 3)
After calculating the index EGR rate EGR_t in step S400, the values of the engine speed Ne and the engine load L are substituted into the reference EGR rate map F (Ne, L), and the reference EGR rate EGR_std that is an appropriate EGR rate is obtained. Is calculated (step S500). Here, the reference EGR rate map F (Ne, L) is a two-dimensional map representing the relationship between the engine speed Ne and the engine load L and the reference EGR rate EGR_std, and is stored in advance in the ROM 142 of the engine controller 140 or the like. ing.

Next, after calculating a deviation EGR_gap that is a deviation between the index EGR rate EGR_t and the reference EGR rate EGR_std (step S600), a corrected EGR value EGR_re is calculated so that the deviation EGR_gap becomes 0 (step S700). Then, based on the corrected EGR value EGR_re, the reference EGR opening degree EGR_s is corrected to the corrected EGR opening degree EGR_s_re (step S800), and the opening degree of the EGR valve member 149 is adjusted based on the value of the corrected EGR opening degree EGR_s_re. (Step S900).

As described above, even if there is no means (sensor) for detecting the flow rate and flow velocity of each gas, the EGR rate can be easily and accurately obtained using the fresh air temperature T1, the EGR gas temperature T2, and the mixed gas temperature T3. EGR_std and EGR_t can be calculated. For this reason, the detection means for calculating the EGR rates EGR_std and EGR_t only needs to have a simple configuration for detecting the temperature.

In addition, since the EGR valve member 149 is feedback controlled based on these calculation results, the EGR main body can be constructed without constructing a complicated control system for detecting the EGR rates EGR_std and EGR_t by detecting the flow rate and flow velocity of each gas. An appropriate amount of EGR gas can be supplied to the case 145. Therefore, it is possible to contribute to the suppression of the component cost and the manufacturing cost.

11 and 12, a structure in which the diesel engine 70 shown in FIGS. 4 to 7 is mounted on the backhoe 100 will be described. As shown in FIGS. 11 and 12, the backhoe 100 includes a crawler-type traveling device 102 having a pair of left and right traveling crawlers 103, and a turning machine body 104 provided on the traveling device 102. The revolving machine body 104 is configured to be horizontally revolved over 360 ° in all directions by a revolving hydraulic motor (not shown). An earthwork plate 105 for ground work is mounted on the rear part of the traveling device 102 so as to be movable up and down. A steering unit 106 and a diesel engine 70 are mounted on the left side of the revolving machine body 104. A working unit 110 having a boom 111 and a bucket 113 for excavation work is provided on the right side of the revolving machine body 104.

The control unit 106 is provided with a control seat 108 on which an operator is seated, an operation means for operating the diesel engine 70 and the like, and a lever or switch as an operation means for the working unit 110. A boom cylinder 112 and a bucket cylinder 114 are arranged on a boom 111 which is a component of the working unit 110. A bucket 113 as an attachment for excavation is pivotally attached to the tip end portion of the boom 111 so as to be inserted and rotated. The boom cylinder 112 or the bucket cylinder 114 is operated to perform earthwork work (ground work such as grooving) by the bucket 113.

A structure in which the diesel engine 70 shown in FIGS. 4 to 7 is mounted on the forklift car 120 will be described with reference to FIGS. As shown in FIGS. 13 and 14, the forklift car 120 includes a traveling machine body 124 having a pair of left and right front wheels 122 and a rear wheel 123. The traveling body 124 is equipped with a control unit 125 and a diesel engine 70. The diesel engine 70 is covered from above with a cover body 133, and the control unit 125 is provided on the cover body 133.

A working part 127 having a fork 126 for cargo handling work is provided on the front side of the traveling machine body 124. A counterweight 131 is provided on the rear side of the traveling machine body 124 to balance the weight with the working unit 127. The control unit 125 is provided with a control seat 128 on which an operator is seated, a control handle 129, levers and switches as operation means for the diesel engine 70 and the working unit 127, and the like.

A fork 126 is mounted on the mast 130, which is a component of the working unit 127, so as to be movable up and down. The fork 126 is moved up and down, a pallet (not shown) loaded with a load is placed on the fork 126, the traveling machine body 124 is moved forward and backward, and a cargo handling operation such as transportation of the pallet is performed. Yes.

The diesel engine 70 is arranged such that the flywheel housing 78 is located on the front side of the traveling machine body 124 and the cooling fan 76 is located on the rear side of the traveling machine body 124. That is, the diesel engine 70 is arranged so that the direction of the engine output shaft 74 is along the front-rear direction in which the working unit 127 and the counterweight 131 are arranged. The diesel engine 70 is supported in an anti-vibration manner via an engine leg 97 on an engine mounting chassis 81 constituting the traveling machine body 124. A mission case 132 is connected to the front side of the flywheel housing 78. The power from the diesel engine 70 via the flywheel 79 is appropriately changed in the transmission case 132 and transmitted to the hydraulic drive sources of the front wheels 122, the rear wheels 123, and the forks 126.

A radiator 134 for cooling the engine opposes the cooling fan 76 at a high position near the counterweight 131 between the control seat 128 and the counterweight 131 disposed behind the control seat 128 in the cover body 133. Are arranged as follows. By blowing cooling air to the radiator 134 by the rotation drive of the cooling fan 76, the radiator 134 is air-cooled.

In addition, this invention is not limited to the above-mentioned embodiment, It can be embodied in various aspects. For example, the engine device for mounting a work vehicle according to the present invention is not limited to the backhoe 100 and the forklift car 120 as described above, but various work vehicles such as agricultural machines such as a combine and a tractor, and special work vehicles such as a crane truck. Widely applicable to. Moreover, the structure of each part in this invention 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.

1 DPF (gas purification filter)
70 Diesel Engine 71 Exhaust Manifold 73 Intake Manifold 76 Cooling Fan 91 EGR Device 145 EGR Body Case 146 as Relay Pipeline Intake Throttle Member 148 Recirculated Exhaust Gas Pipe 149 EGR Valve Member 154 Spacer

Claims

An EGR device that recirculates a part of exhaust gas discharged from an exhaust manifold to an intake manifold as EGR gas,
The intake manifold and an intake throttle member for introducing fresh air are connected via a relay line, and an outlet side of a return line extending from the exhaust manifold is connected to the relay line.
EGR device.
The outlet side of the reflux line is connected to the relay line via an EGR valve member that adjusts the supply amount of the EGR gas, and the intake throttle member, the relay line, and the EGR valve member are connected to each other. Unitized,
The EGR device according to claim 1.
While the outlet side of the reflux line is connected to the relay line via an EGR valve member that adjusts the supply amount of the EGR gas,
The inlet portion of the intake manifold protrudes upward, the intake throttle member, the relay conduit, and the EGR valve member are exposed on the intake manifold, and the relay conduit and the EGR valve member are Arranged side by side,
The EGR device according to claim 1.
A plurality of temperature detection means for calculating the EGR rate of the mixed gas supplied to the intake manifold is provided in the relay pipe line.
The EGR apparatus according to claim 3.
An engine having an intake manifold and an exhaust manifold, and the EGR device according to any one of claims 1 to 4,
Engine equipment.
The relay pipe is arranged in a posture extending in parallel with the output shaft of the engine in plan view so that the intake throttle member is positioned closer to the flywheel housing of the engine.
The engine device according to claim 5.
An inlet portion of the intake manifold protrudes upward, and the intake throttle member, the relay pipe line, and the EGR valve member are located on the intake manifold, and are cooled by a cooling fan provided in the engine. Configured to hit the wind,
The engine device according to claim 5.