JP2020165434A - Engine device - Google Patents

Abstract

To secure rigidity of a support base supporting an exhaust emission control system and cool an engine properly.SOLUTION: An exhaust emission control system 100 is provided through a support base 121 at an engine device 1. A cooling air passage 148 in which cooling air from a cooling fan 9 flows is formed between a cylinder head cover 18 on the cylinder head 2 and the support base 121.SELECTED DRAWING: Figure 11

Description

The present invention relates to an engine device including an exhaust gas purification device.

With the recent application of higher emission regulations for diesel engines (hereinafter referred to simply as engines), exhaust gas that purifies air pollutants in exhaust gas is applied to agricultural work vehicles and construction civil engineering machines on which engines are installed. It is required to install a purification device. As an exhaust gas purifying device, a diesel particulate filter (DPF) that collects particulate matter (soot, particulate) and the like in the exhaust gas is known (see, for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2012-077621 Japanese Unexamined Patent Publication No. 2013-173428 Japanese Patent No. 5449517

When the exhaust gas purification device is mounted on the upper part of the engine in order to mount the exhaust gas purification device compactly on the engine, it is necessary to appropriately cool the engine while ensuring the rigidity of the support base.

An object of the present invention is to provide an engine device which has been improved by examining the above-mentioned current situation.

In the engine device of the present invention, in an engine device in which an exhaust gas purification device is provided via a support base, a cooling air passage through which cooling air from a cooling fan flows is formed between a cylinder head cover on a cylinder head and the support base. It is what has been done.

In the engine device of the present invention, for example, the support base may include a mounting portion on which the exhaust gas purifying device is mounted and a plurality of legs fixed to the cylinder head.

Further, in the engine device of the present invention, the support base is arranged above one side surface of the two side surfaces of the cylinder head intersecting the exhaust side surface and the intake side surface of the cylinder head, and as the leg portion. The exhaust side leg portion fixed to the exhaust side surface, the intake side leg portion fixed to the intake side surface, and the central leg portion fixed to the one side surface may be provided.

Further, the engine device of the present invention may be provided with the cooling fan on the other side surface side of the two side surfaces of the cylinder head.

Further, an EGR device that returns a part of the exhaust gas discharged from the exhaust manifold to the intake manifold as EGR gas, an EGR cooler that cools the EGR gas, and an exhaust pressure sensor that detects the exhaust gas pressure in the exhaust manifold are provided. The EGR cooler and the exhaust pressure sensor may be attached to the one side surface of the cylinder head.

Further, an intake manifold may be provided on the intake side surface of the cylinder head, and the intake side leg may be fixed to the intake manifold.

In the engine device of the present invention, in an engine device in which an exhaust gas purification device is provided via a support base, a cooling air passage through which cooling air from a cooling fan flows is formed between the cylinder head cover on the cylinder head and the support base. Therefore, the cooling air from the cooling fan can be guided to the cylinder head through the cooling air passage, and the cylinder head can be appropriately cooled.

It is a schematic front view of one Embodiment of an engine device. It is a schematic rear view of the same embodiment. It is a schematic left side view of the same embodiment. It is a schematic right side view of the same embodiment. It is a schematic plan view of the same embodiment. It is a schematic left side view showing the area around the two-stage turbocharger in an enlarged manner. It is a schematic front view which shows the area around the two-stage turbocharger enlarged. It is a schematic rear view showing the area around the two-stage turbocharger in an enlarged manner. It is a schematic plan view which shows the area around a low-pressure stage turbocharger enlarged by cutting out a part of a cylinder head cover. It is a schematic perspective view for demonstrating the mounting structure of the low pressure stage turbocharger. It is a schematic front view which shows the periphery of the support stand which supports an exhaust gas purification apparatus in an enlarged manner. It is a schematic left side view which shows the area around the support stand enlarged. It is a schematic right side view which shows the area around the support stand enlarged. It is the schematic plan view which shows the periphery of the support stand enlarged. It is a schematic exploded perspective view for demonstrating the mounting structure of the support base and an exhaust gas purification device. It is a schematic left side view which shows the support base and the exhaust gas purification apparatus in the AA position cross section of FIG. It is a schematic front view which shows the periphery of a cylinder head enlarged. It is the schematic plan view which shows the periphery of the front part of the cylinder head enlarged. It is a schematic left side view which shows the periphery of the front part of the cylinder head enlarged. It is a schematic perspective view which shows the front part of the cylinder head and the EGR cooler by cutting out a part. It is a schematic plan view sectional view which shows the structure of the exhaust flow path and the intake flow path in a cylinder head. It is a schematic front view which shows the arrangement of the wire harness around the front part of a cylinder head. It is a schematic plan view which shows the arrangement of the wire harness around the front part of a cylinder head.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. First, the overall structure of the engine 1 as an example of the engine device will be described with reference to FIGS. 1 to 5. In this embodiment, the engine 1 is composed of a diesel engine. Engine 1 In the following description, both sides parallel to the crankshaft 5 (sides on both sides of the crankshaft 5) are left and right, the flywheel housing 7 installation side is the front side, and the cooling fan 9 installation side is the rear side. For the sake of convenience, these are used as the reference for the positional relationship between the four sides and the top and bottom of the engine 1.

As shown in FIGS. 1 to 5, the intake manifold 3 is arranged on one side of the engine 1 parallel to the crankshaft 5, and the exhaust manifold 4 is arranged on the other side. In the embodiment, the intake manifold 3 is integrally molded with the cylinder head 2 on the right side surface of the cylinder head 2. An exhaust manifold 4 is installed on the left side surface of the cylinder head 2. The cylinder head 2 is mounted on a cylinder block 6 in which a crankshaft 5 and a piston (not shown) are built.

The front and rear tip sides of the crankshaft 5 are projected from both front and rear surfaces of the cylinder block 6. The flywheel housing 7 is fixed to one side of the engine 1 that intersects with the crankshaft 5 (in the embodiment, the front side surface side of the cylinder block 6). The flywheel 8 is arranged in the flywheel housing 7. The flywheel 8 is fixed to the front end side of the crankshaft 5 and is configured to rotate integrally with the crankshaft 5. The operating portion of a working machine (for example, a hydraulic excavator, a forklift, etc.) is configured to take out the power of the engine 1 via the flywheel 8. A cooling fan 9 is provided on the other side of the engine 1 that intersects with the crankshaft 5 (in the embodiment, the rear side surface side of the cylinder block 6). It is configured to transmit rotational force from the rear end side of the crankshaft 5 to the cooling fan 9 via the belt 10.

An oil pan 11 is arranged on the lower surface of the cylinder block 6. Lubricating oil is stored in the oil pan 11. The lubricating oil in the oil pan 11 is sucked by a lubricating oil pump (not shown) which is a connecting portion of the cylinder block 6 with the flywheel housing 7 and is arranged on the right side surface side of the cylinder block 6, and the cylinder block 6 It is supplied to each lubricating portion of the engine 1 via an oil cooler 13 and an oil filter 14 arranged on the right side surface of the engine 1. The lubricating oil supplied to each lubricating portion is then returned to the oil pan 11. The lubricating oil pump is configured to be driven by the rotation of the crankshaft 5.

As shown in FIG. 4, a fuel supply pump 15 for supplying fuel is attached to the right side portion of the engine 1 at a connecting portion of the cylinder block 6 with the flywheel housing 7. The fuel supply pump 15 is arranged below the EGR device 24. Further, a common rail 16 is arranged between the intake manifold 3 of the cylinder head 2 and the fuel supply pump 15. The common rail 16 is fixed to the upper front portion of the right side surface of the cylinder block 6. Injectors for four cylinders (not shown) having an electromagnetic open / close control type fuel injection valve are provided on the upper surface of the cylinder head 2 covered with the cylinder head cover 18.

A fuel tank (not shown) mounted on a work vehicle is connected to each injector via a fuel supply pump 15 and a cylindrical common rail 16. The fuel in the fuel tank is pumped from the fuel supply pump 15 to the common rail 16, and the high-pressure fuel is stored in the common rail 16. By controlling the opening and closing of the fuel injection valve of each injector, the high-pressure fuel in the common rail 16 is injected from each injector into each cylinder of the engine 1.

As shown in FIGS. 2 and 5, the upper surface of the cylinder head cover 18 covering the intake valve and the exhaust valve (not shown) provided on the upper surface of the cylinder head 2 leaks from the combustion chamber of the engine 1 to the upper surface of the cylinder head 2. A blow-by gas reduction device 19 for taking in the blow-by gas is provided. The blow-by gas outlet of the blow-by gas reduction device 19 is communicated with the intake portion of the two-stage turbocharger 30 via the reduction hose 68. The blow-by gas from which the lubricating oil component has been removed in the blow-by gas reduction device 19 is returned to the intake manifold 3 via the two-stage turbocharger 30 and the like.

As shown in FIG. 3, on the left side of the engine 1, an engine starting starter 20 is attached to the flywheel housing 7. The engine starting starter 20 is arranged below the exhaust manifold 4. The engine starting starter 20 is attached to the left side portion of the rear side surface of the flywheel housing 7 at a position below the connecting portion between the cylinder block 6 and the flywheel housing 7.

As shown in FIG. 2, a cooling water pump 21 for lubricating cooling water is arranged at a portion on the left side of the rear side surface of the cylinder block 6. Further, an alternator 12 as a generator that generates electricity by the power of the engine 1 is provided on the left side of the cooling water pump 21. Rotational power is transmitted from the front end side of the crankshaft 5 to the cooling fan 9, the alternator 12, and the cooling water pump 21 via the belt 10. The cooling water in the radiator (not shown) mounted on the work vehicle is supplied to the cooling water pump 21 by driving the cooling water pump 21. Then, cooling water is supplied into the cylinder head 2 and the cylinder block 6 to cool the engine 1.

As shown in FIG. 3, the cooling water pump 21 is arranged at a height lower than that of the exhaust manifold 4, and the cooling water inlet pipe 22 communicating with the cooling water outlet of the radiator is on the left side surface of the cylinder block 6. It is fixed at a position substantially the same height as the cooling water pump 21. On the other hand, as shown in FIGS. 2 and 5, the cooling water outlet pipe 23 communicating with the cooling water inlet of the radiator is fixed to the rear right side portion of the upper surface of the cylinder head 2. The cylinder head 2 has a cooling water drainage portion 35 at the right rear corner thereof, and a cooling water outlet pipe 23 is installed on the upper surface of the cooling water drainage portion 35.

As shown in FIGS. 4 and 5, the EGR device 24 is arranged on the right side of the cylinder head 2. The EGR device 24 has a collector 25 as a relay line that mixes the recirculated exhaust gas of the engine 1 (EGR gas from the exhaust manifold 4) and fresh air (external air from the air cleaner) and supplies the intake manifold 3 to the intake manifold 3. , The intake throttle member 26 that communicates the collector 25 to the air cleaner, the recirculation exhaust gas pipe 28 that is a part of the recirculation pipeline connected to the exhaust manifold 4 via the EGR cooler 27, and the collector to the recirculation exhaust gas pipe 28. It has an EGR valve member 29 through which 25 is communicated.

In this embodiment, the collector 25 of the EGR device 24 is connected to the right side surface of the intake manifold 3 which is integrally molded with the cylinder head 2 and constitutes the right side surface of the cylinder head 2. That is, the outlet opening of the collector 25 is connected to the inlet opening of the intake manifold 3 provided on the right side surface of the cylinder head 2. Further, the EGR gas inlet of the recirculation exhaust gas pipe 28 is connected to the EGR gas outlet of the EGR gas passage provided in the cylinder head 2 at a front portion on the right side surface of the cylinder head 2. The collector 25 is attached to the intake manifold 3, and the recirculation exhaust gas pipe 28 is attached to the cylinder head 2, so that the EGR device 24 is fixed to the cylinder head 2.

In the EGR device 24, the intake manifold 3 and the intake throttle member 26 for introducing fresh air are communicatively connected via the collector 25. An EGR valve member 29 connected to the outlet side of the recirculation exhaust gas pipe 28 is communicated with the collector 25. The collector 25 is formed in a substantially tubular shape extending in the front-rear direction. The intake throttle member 26 is bolted to the air supply intake side (front side in the longitudinal direction) of the collector 25. The air supply / discharge side of the collector 25 is bolted to the inlet side of the intake manifold 3. The EGR valve member 29 adjusts the amount of EGR gas supplied to the collector 25 by adjusting the opening degree of the EGR valve inside the EGR valve member 29.

Fresh air is supplied into the collector 25, and EGR gas (a part of the exhaust gas discharged from the exhaust manifold 4) is supplied from the exhaust manifold 4 into the collector 25 via the EGR valve member 29. After the fresh air and the EGR gas from the exhaust manifold 4 are mixed in the collector 25, the mixed gas in the collector 25 is supplied to the intake manifold 3. That is, a part of the exhaust gas discharged from the engine 1 to the exhaust manifold 4 is returned from the intake manifold 3 to the engine 1, so that the maximum combustion temperature during high load operation is lowered, and NOx (nitrogen oxide) from the engine 1 is lowered. The amount of emissions (things) will be reduced.

As shown in FIGS. 1 and 3 to 5, the EGR cooler 27 is fixed to the front side surface of the cylinder head 2. The cooling water and EGR gas flowing in the cylinder head 2 flow in and out of the EGR cooler 27, and the EGR gas is cooled in the EGR cooler 27. A pair of left and right EGR cooler connecting portions 33, 34 for connecting the EGR cooler 27 are projected from the front side surface of the cylinder head 2. The EGR cooler 27 is connected to the front side surfaces of the EGR cooler connecting portions 33 and 34. That is, the EGR cooler 27 is arranged at an upper position of the flywheel housing 7 and at a front position of the cylinder head 2 so that the rear side surface of the EGR cooler 27 and the front side surface of the cylinder head 2 are separated from each other.

As shown in FIGS. 1 to 3 and 5, a two-stage turbocharger 30 is arranged on the left side of the cylinder head 2. The two-stage turbocharger 30 includes a high-pressure stage turbocharger 51 and a low-pressure stage turbocharger 52. The high-pressure turbocharger 51 includes a high-pressure turbine case 53 having a built-in turbine wheel (not shown) and a high-pressure compressor case 54 having a blower wheel (not shown). The low-pressure stage turbocharger 52 includes a low-pressure stage turbine case 55 having a built-in turbine wheel (not shown) and a low-pressure stage compressor case 56 having a built-in blower wheel (not shown).

In the exhaust path of the two-stage turbocharger 30, a high-pressure stage turbine case 53 is connected to the exhaust manifold 4, and a low-pressure stage turbine case 55 is connected to the high-pressure stage turbine case 53 via a high-pressure exhaust gas pipe 59. The exhaust connecting pipe 119 is connected to the case 55. The high-pressure exhaust gas pipe 59 is formed of a flexible pipe. In this embodiment, a part of the high-pressure exhaust gas pipe 59 is formed in a bellows shape.

A tail pipe (not shown) is connected to the exhaust connecting pipe 119 via an exhaust gas purifying device 100. The exhaust gas discharged from each cylinder of the engine 1 to the exhaust manifold 4 is discharged to the outside from the tail pipe via the two-stage turbocharger 30 and the exhaust gas purification device 100 and the like.

In the intake path of the two-stage turbocharger 30, the low-pressure stage compressor case 56 is connected to the air cleaner via the air supply pipe 62, and the high-pressure stage compressor case 54 is connected to the low-pressure stage compressor case 56 via the low-pressure fresh air passage pipe 65. Then, the intake throttle member 26 of the EGR device 24 is connected to the high-pressure stage compressor case 54 via an intercooler (not shown). The fresh air (external air) sucked into the air cleaner is dust-removed and purified by the air cleaner, and then sent to the intake manifold 3 via the two-stage turbocharger 30, the intercooler, the intake throttle member 26, the collector 25, and the like. , And it is supplied to each cylinder of the engine 1.

The exhaust gas purification device 100 is for collecting particulate matter (PM) and the like in the exhaust gas. As shown in FIGS. 1 to 5, the exhaust gas purification device 100 has a substantially cylindrical shape extending in the left-right direction so as to intersect the crankshaft 5 in a plan view. In this embodiment, the exhaust gas purification device 100 is arranged above the front side surface of the cylinder head 2. The exhaust gas purification device 100 is supported by the front portion of the cylinder head 2 via the left support bracket 117, the right support bracket 118, and the support base 121.

The exhaust gas intake side and the exhaust gas discharge side are separately provided on the left and right sides (one end side in the longitudinal direction and the other end side in the longitudinal direction) of the exhaust gas purification device 100. The exhaust gas inlet pipe 116 on the exhaust gas intake side of the exhaust gas purification device 100 has two stages via an exhaust connecting member 120 having a substantially L-shaped exhaust gas passage in a side view and a linear exhaust connecting pipe 119. It is connected to the exhaust outlet of the low pressure stage turbine case 55 of the supercharger 30. The exhaust connecting member 120 is fixed to the left side surface of the support base 121. The exhaust gas discharge side of the exhaust gas purification device 100 is connected to the exhaust gas intake side of the tail pipe (not shown).

The exhaust gas purification device 100 has a structure in which a diesel oxidation catalyst 102 such as platinum and a honeycomb structure soot filter 103 are arranged in series and housed therein. In the above configuration, nitrogen dioxide (NO2) produced by the oxidizing action of the diesel oxidation catalyst 102 is taken into the suit filter 103. Particulate matter contained in the exhaust gas of the engine 1 is collected by the suit filter 103 and continuously oxidized and removed by nitrogen dioxide. Therefore, in addition to removing particulate matter (PM) in the exhaust gas of the engine 1, the contents of carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas of the engine 1 are reduced.

The exhaust gas purification device 100 includes an upstream case 105 having an exhaust gas inlet pipe 116 on the outer peripheral surface, an intermediate case 106 connected to the upstream case 105, and a downstream case 107 connected to the intermediate case 106. The upstream case 105 and the intermediate case 106 are connected side by side in series to form a gas purification housing 104 made of a heat-resistant metal material. The diesel oxidation catalyst 102 and the soot filter 103 are housed in the gas purification housing 104 via a cylindrical inner case (not shown). Further, the downstream case 107 constitutes a muffler by incorporating an inner case (not shown) having a large number of muffling holes and filling the case with a ceramic fiber muffling material. ing.

When the exhaust gas passes through the diesel oxidation catalyst 102 and the soot filter 103, if the exhaust gas temperature exceeds the renewable temperature (for example, about 300 ° C.), the action of the diesel oxidation catalyst 102 causes nitric oxide in the exhaust gas. Nitric oxide oxidizes to unstable nitric oxide. Then, the oxygen released when nitrogen dioxide returns to nitric oxide oxidizes and removes the particulate matter deposited on the suit filter 103, so that the particulate matter collection ability of the suit filter 103 is restored and the suit is used. The filter 103 will be regenerated.

Next, the configuration and mounting structure of the two-stage turbocharger 30 will be described with reference to FIGS. 6 to 10 and the like. The two-stage turbocharger 30 compresses the fresh air flowing into the intake manifold 3 of the cylinder head 2 by the fluid energy of the exhaust gas discharged from the exhaust manifold 4. The two-stage turbocharger 30 is composed of a high-pressure stage turbocharger 51 connected to the exhaust manifold 4 and a low-pressure stage turbocharger 52 connected to the high-pressure stage turbocharger 51.

As shown in FIGS. 7 and 8, the high-pressure turbocharger 51 is arranged on the left side of the exhaust manifold 4. The low-pressure stage turbocharger 52 is arranged above the exhaust manifold 4. That is, the small-capacity high-pressure turbocharger 51 is arranged to face the left side surface of the exhaust manifold 4, while the large-capacity low-pressure turbocharger 52 faces the cylinder head 2 and the left side surface of the cylinder head cover 18. Is arranged. Therefore, not only can the exhaust manifold 4 and the two-stage turbocharger 30 be compactly arranged in a substantially square frame in front view and rear view in the space on the left side of the cylinder head 2, but also the uppermost portion of the two-stage turbocharger 30 can be arranged compactly. The position can be set lower than the uppermost position of the engine 1. Therefore, it can contribute to the miniaturization of the engine 1.

Further, as shown in FIGS. 3 and 6, the low-pressure turbocharger 52 is arranged on the left side of the cylinder head 2 and in front of the high-pressure turbocharger 51 when the engine 1 is viewed from the left side. Will be done. Therefore, below the low-pressure turbocharger 52, a space for arranging other application components can be widened around the front portion of the left side surface of the cylinder block 6. For example, an external auxiliary machine such as a hydraulic pump that is operated by the rotational force of the crankshaft 5 can be arranged between the low-pressure stage turbocharger 52 and the engine starting starter 20.

As shown in FIGS. 6 to 8 and the like, the high-pressure stage turbocharger 51 includes a high-pressure stage turbine case 53, a high-pressure stage compressor case 54 arranged on the rear side of the high-pressure stage turbine case 53, and both cases 53, 54. A high-voltage stage center housing 72 for connecting the above is provided. The high-pressure stage turbine case 53 includes a high-pressure stage exhaust inlet 57 that communicates with the exhaust manifold exhaust outlet 49 of the exhaust manifold 4 and a high-pressure stage exhaust outlet 58 that communicates with the upstream end of the high-pressure exhaust gas pipe 59. The high-pressure stage compressor case 54 includes a high-pressure stage fresh air inlet 66 that communicates with the downstream end of the low-pressure fresh air passage pipe 65, and a high-pressure stage fresh air supply port 67 that is connected to an intercooler (not shown). The upstream end of the pipe means the upstream end of the gas flow, and the downstream end means the downstream end of the gas flow.

On the other hand, the low-pressure stage turbocharger 52 includes a low-pressure stage turbine case 55, a low-pressure stage compressor case 56 arranged on the rear side of the low-pressure stage turbine case 55, and a low-pressure stage center housing 75 connecting both cases 55 and 56. Be prepared. The low-pressure stage turbine case 55 includes a low-pressure stage exhaust inlet 60 that communicates with the downstream end of the high-pressure exhaust gas pipe 59, and a low-pressure stage exhaust outlet 61 that communicates with the upstream end of the exhaust connecting pipe 119. The low-pressure stage compressor case 56 includes a low-pressure stage fresh air inlet 63 that communicates with the downstream end of the air supply pipe 62, and a low-pressure stage fresh air supply port 64 that communicates with the upstream end of the low-pressure fresh air passage pipe 65.

The exhaust manifold 4 opens the exhaust manifold exhaust outlet 49 for exhausting the exhaust gas toward the left. The high-pressure stage turbine case 53 opens the high-pressure stage exhaust inlet 57 toward the exhaust manifold 4, while opening the high-pressure stage exhaust outlet 58 toward the front. Further, in the low-pressure stage turbine case 55, the low-pressure stage exhaust inlet 60 is opened downward, while the low-pressure stage exhaust outlet 61 is opened forward.

As shown in FIGS. 6 to 8, in the two-stage turbocharger 30, the high-pressure stage compressor case 54 opens the high-pressure stage fresh air inlet 66 toward the rear, while lowering the high-pressure stage fresh air supply port 67. It is opened toward. Further, the low-pressure stage compressor case 56 is configured such that the low-pressure stage fresh air inlet 63 is opened rearward, while the low-pressure stage fresh air supply port 64 is projected rearward after protruding from the left side. Then, while the downstream end of the U-shaped low-pressure fresh air passage pipe 65 is connected to the high-pressure stage fresh air inlet 66, the low-pressure stage fresh air supply port 64 is connected to the upstream end of the low-pressure fresh air passage pipe 65. Is connected to.

As shown in FIGS. 6 to 8, the exhaust manifold exhaust outlet 49 of the exhaust manifold 4 and the high pressure stage exhaust inlet 57 of the high pressure stage turbine case 53 are bolted at the flange portion. As a result, the high-pressure turbocharger 51 is fixed to the robust exhaust manifold 4. Further, the high pressure stage exhaust outlet 58 of the high pressure stage turbine case 53 is bolted to the downstream end (rear end) of the substantially L-shaped high pressure exhaust gas pipe 59 at the flange portion, while the low pressure of the low pressure stage turbine case 55. The stage exhaust inlet 60 is bolted to the upstream end (upper end) of the high-pressure exhaust gas pipe 59 at a flange. The substantially L-shaped high-pressure exhaust gas pipe 59 is composed of a flexible pipe, and in this embodiment, a bellows pipe portion 59a is provided at a portion extending in the front-rear direction.

As shown in FIGS. 9 and 10, the low-pressure turbocharger 52 is fixed to the left side surface (exhaust side surface) of the cylinder head 2. In this embodiment, the low-pressure stage turbocharger mounting portion 131 is provided at a portion closer to the center of the left side surface of the cylinder head 2 (see also FIGS. 12, 16, and 19). The low-pressure stage turbocharger mounting portion 131 is provided above the exhaust manifold 4 and at a position facing the low-pressure stage turbine case 55. The low-pressure turbocharger 52 is attached to the low-pressure turbocharger mounting portion 131 via a substantially L-shaped mounting bracket 132. The mounting bracket 132 includes a supercharger-side flat surface portion 132a arranged in the left-right direction and a head-side flat surface portion 132b projecting forward from the right end of the supercharger-side flat surface portion 132a.

The supercharger side flat surface portion 132b of the mounting bracket 132 is fixed to the right edge portion of the front side surface of the low pressure stage compressor case 56 by the bolt 133. The head-side flat surface portion 132a of the mounting bracket 132 is fixed to the low-pressure stage turbocharger mounting portion 131 by a pair of front and rear bolts 133. As a result, the low-pressure turbocharger 52 is fixed to the robust cylinder head 2.

In this embodiment, the low-pressure turbocharger 52 is fixed to the left side surface (exhaust side surface) of the cylinder head 2, and the high-pressure turbocharger 51 is fixed to the exhaust manifold 4, so that the two-stage turbocharger 30 is installed. The constituent high-pressure turbocharger 51 and the low-pressure turbocharger 52 can be distributed to the robust cylinder head 2 and the exhaust manifold 4 and firmly fixed. Further, since the low-pressure turbocharger 52 is connected to the support base 121 fixed to the front portion of the cylinder head 2 via the exhaust connecting pipe 119 and the exhaust connecting member 120, the low-pressure turbocharger 52 is used as an engine. It can be securely fixed to 1, and by extension, the two-stage turbocharger 30 can be securely fixed to the engine 1.

Further, since the high pressure stage exhaust port 58 of the high pressure stage turbocharger 51 and the low pressure stage exhaust port 60 of the low pressure stage supercharger 52 are connected via a flexible high pressure exhaust gas pipe 59, heat elongation occurs. The risk of low-cycle fatigue failure of the high-pressure exhaust gas pipe 59 can be reduced. Further, the stress applied to the two-stage turbocharger 30 due to the thermal elongation of the high-pressure exhaust gas pipe 59 can be reduced. As a result, the stress applied to the connecting portion between the high-pressure stage turbocharger 51 and the exhaust manifold 4 and the stress applied to the connecting portion between the low-pressure stage supercharger 52 and the cylinder head 2 can be reduced, resulting in poor connection or connection at these connecting portions. It is possible to prevent damage to the members.

As shown in FIGS. 9 and 10, the cylinder head 2 is provided with a rib 135 extending from the low-pressure stage turbocharger mounting portion 131 toward the right side surface (intake side surface) of the cylinder head 2 inside. There is. The rib 135 projects upward from the bottom surface 136 of the cylinder head. As a result, the rigidity around the low-pressure turbocharger mounting portion 131 of the cylinder head 2 can be improved, and deformation of the cylinder head 2 due to the mounting of the low-pressure turbocharger 52 on the cylinder head 2 can be prevented. Further, on the bottom surface 136 of the cylinder head, a valve arm mechanism installation seat 137 extending in the left-right direction is projected upward from the right end portion of the rib 135. As a result, the rigidity of the rib 135 can be improved, and by extension, the rigidity around the low-pressure turbocharger mounting portion 131 can be improved.

In this embodiment, the engine 1 is of the OHV type, and the space surrounded by the cylinder head 2 and the cylinder head cover 18 is configured as a valve arm chamber. As shown in FIG. 9, the injector 138 and the valve operating mechanism are housed in the valve arm chamber. A plurality of valve arm mechanism installation seats 137 are arranged at equal intervals in the front-rear direction, and a valve arm shaft support portion 139 for supporting the valve arm shaft (not shown) is arranged on the valve arm mechanism installation seat 137. A plurality of valve arms 140 are oscillatingly supported. The intake valve and the exhaust valve (not shown) of each cylinder are configured to open and close by swinging each valve arm 189 around the valve arm axis.

As shown in FIGS. 3, 5 and 6, the low-pressure stage turbocharger 52 is arranged closer to the front side surface (one side surface) of the cylinder head 2 when viewed from the left side, while the low-pressure stage turbine case 55. The low-pressure stage exhaust outlet 61 is provided toward the front side surface side of the cylinder head 2. Further, the exhaust gas inlet pipe 116 constituting the exhaust inlet of the exhaust gas purification device 100 is arranged near the corner where the front side surface and the right side surface (exhaust side surface) of the cylinder head 2 intersect. Therefore, the exhaust connecting pipe 119 and the exhaust connecting member 120 as a pipe connecting the low pressure stage exhaust outlet 61 of the low pressure stage supercharger 52 and the exhaust gas inlet pipe 116 of the exhaust gas purification device 100 can be shortened and simplified. As a result, the exhaust gas supplied to the exhaust gas purification device 100 can be maintained at a high temperature, and a decrease in the regeneration ability of the exhaust gas purification device 1 can be prevented.

In the present invention, if the exhaust inlet of the exhaust gas purification device 100 is arranged near the corner where the front side surface (one side surface) and the right side surface (exhaust side surface) of the cylinder head 2 intersect, the exhaust gas is exhausted. The same effect as that of this embodiment can be obtained regardless of the mounting position and the arrangement direction of the gas purification device 100. For example, the exhaust gas purification device 100 may be arranged horizontally and horizontally above the flywheel housing 7 in front of the cylinder head 2 (see, for example, Japanese Patent Application Laid-Open No. 2011-012598), and may be arranged in the front-rear direction above the cylinder head 2. It may be arranged horizontally (in the direction along the crankshaft 5) (see, for example, Japanese Patent Application Laid-Open No. 2016-0798770).

As shown in FIGS. 3, 5 and 6, a blow-by gas reduction device 19 that takes in blow-by gas is installed on the cylinder head 2. The blow-by gas reduction device 19 is placed and fixed on the upper surface of the cylinder head cover 18 that covers the upper surface of the cylinder head 2. Above the cylinder head 2, the blow-by gas outlet 70 of the blow-by gas reduction device 19 is arranged at a position closer to the rear side surface (the other side surface) of the cylinder head 2 toward the left side surface side. Further, the low pressure stage fresh air inlet 63 of the low pressure stage compressor case 56 of the low pressure stage turbocharger 52 is opened toward the rear. An air supply pipe 62 extending in the front-rear direction is connected to the low-pressure stage fresh air inlet 63. As a result, the air supply pipe 62 can be arranged in the vicinity of the blow-by gas outlet 70, and the reduction hose 68 connecting the blow-by gas outlet 70 and the air supply pipe 62 can be shortened to prevent freezing in the reduction hose 68 in a low temperature environment.

As shown in FIG. 6, the low-pressure stage compressor case 56 and the high-pressure stage compressor case 54 have the low-pressure stage fresh air inlet 63, the low-pressure stage fresh air supply port 64, and the high-pressure stage fresh air inlet 66 directed in the same direction (rearward). It is open. Therefore, the air supply pipe 62 communicating with the air cleaner can be easily connected to the low pressure stage fresh air inlet 63, and the low pressure fresh air passage pipe 65 can be easily connected to the low pressure stage fresh air supply port 64 and the high pressure stage fresh air inlet 66. As it is, the assembly workability can be improved.

Further, the low-pressure fresh air passage pipe 65 has a substantially U-shaped metal pipe 65a whose one end is bolted to the high-pressure stage fresh air inlet 66 by flange connection, and the other end of the metal pipe 65a and the low-pressure stage of the low-pressure stage compressor case 56. It is composed of a resin pipe 65b that communicates with the fresh air supply port 64. As a result, in the low-pressure fresh air passage pipe 65, the metal pipe 65a is fixed to the high-pressure stage compressor case 54 with high rigidity, while the resin pipe 65b alleviates the assembly error between the low-pressure stage compressor case 56 and the metal pipe 65a. It can be communicated.

Further, the low-pressure stage fresh air supply port 64 of the low-pressure stage compressor case 56 extends diagonally upward to the left from the lower left portion of the outer peripheral surface of the low-pressure stage compressor case 56, and is further curved toward the rear. The curvature of the bent portion of the passage pipe 65 (metal pipe 65a) can be increased. Therefore, the generation of turbulent flow in the low-pressure fresh air passage pipe 65 is suppressed, and the compressed air discharged from the low-pressure stage compressor case 56 is smoothly supplied to the high-pressure stage compressor case 54.

As shown in FIG. 8, the high-pressure stage turbocharger 51 is provided with a fresh air supply port 64 extending downward at a portion on the right side of the lower outer peripheral surface of the high-pressure stage compressor case 54. The high-pressure stage compressor case 54 is connected to a high-pressure fresh air passage pipe 71 that communicates with the intercooler, and supplies compressed air to the intercooler via the high-pressure fresh air passage pipe 71. Further, below the high-pressure stage compressor case 54, a cooling water inlet pipe 22 that opens toward the left side is provided. A cooling water pipe 150 connected to a radiator is connected to the cooling water inlet pipe 22. For this reason, the routing of the high-pressure fresh air passage pipe 71 and the cooling water pipe 150 can be integrated, which not only simplifies the piping structure on the machine side on which the engine 1 is mounted, but also facilitates assembly work and maintenance work. it can.

Further, as shown in FIGS. 2, 4 and 5, the engine 1 has a cooling water outlet pipe 23, an air supply pipe 62, and an intake throttle member 26 arranged at the rear portion (cooling fan 9 side). Therefore, when the radiator, the air cleaner, and the intercooler that utilize the cooling air of the cooling fan 9 are arranged behind the cooling fan 9 on the machine side on which the engine 1 is mounted, the cooling water piping connected to the radiator, the air cleaner, and the intercooler are arranged. Not only can the length of the fresh air piping that communicates with the intercooler be shortened, but the piping connection work can be done collectively. Therefore, not only the assembly workability and maintenance workability on the machine side are facilitated, but also the parts to be connected to the engine 1 can be efficiently arranged on the machine side.

As shown in FIGS. 6 to 8, in the high-pressure stage turbocharger 51, high-pressure is applied to the upper and lower parts of the outer peripheral surface of the high-pressure stage center housing 72 which is a connecting portion between the high-pressure stage turbine case 53 and the high-pressure stage compressor case 54. The lubricating oil supply pipe 73 and the high pressure lubricating oil return pipe 74 are connected. In the low-pressure turbocharger 52, the low-pressure lubricating oil supply pipe 76 and the low-pressure lubricating oil are placed on the upper and lower outer peripheral surfaces of the low-pressure stage center housing 75, which is the connecting portion between the low-pressure turbine case 55 and the low-pressure compressor case 56. The return pipe 77 is connected.

The lower end of the high-pressure lubricating oil supply pipe 73 is connected to the connecting member 78a provided at the center of the left side surface of the cylinder block 6, while the upper end is connected to the upper part of the high-pressure stage center housing 72 of the high-pressure stage supercharger 51. Has been done. A connecting joint 78b is installed above the high-pressure stage center housing 72 to communicate the upper end of the high-pressure lubricating oil supply pipe 73 and the lower end of the low-pressure lubricating oil supply pipe 76. The upper end of the low-pressure lubricating oil supply pipe 76 is connected to a connecting member 78c provided above the low-pressure stage center housing 75 of the low-pressure stage turbocharger 52. As a result, the lubricating oil flowing through the oil passage in the cylinder block 6 is supplied to the high-pressure stage center housing 72 of the high-pressure stage turbocharger 51 through the high-pressure lubricating oil supply pipe 73, and the high-pressure lubricating oil supply pipe 73 and It is supplied to the low-pressure stage center housing 75 of the low-pressure stage turbocharger 52 through the low-pressure lubricating oil supply pipe 76.

The high-pressure lubricating oil supply pipe 73 is guided diagonally upward from the connecting member 78a on the left side surface of the cylinder block 6, passes between the high-pressure stage compressor case 54 and the cylinder block 6, and faces the left side surface of the cylinder head 2. You will be guided to the position where you want to. Further, the high-pressure lubricating oil supply pipe 73 is guided to the connecting joint 78b through the right side of the high-pressure stage center housing 72 while bypassing the rear end portion of the exhaust manifold 4. Further, the low-pressure lubricating oil supply pipe 76 has a substantially L-shape when viewed from the side, and is guided from the connecting joint 78b to the connecting member 78c along the high-pressure supercharger 51 and the high-pressure exhaust gas pipe 59. Be taken. In this way, the lubricating oil supply pipes 73 and 76 are shortened, and the lubricating oil is efficiently supplied to the two-stage turbocharger 30 by piping so as to surround the two-stage turbocharger 30, which is a highly rigid component. At the same time, it is possible to prevent damage to the lubricating oil supply pipes 73 and 76 due to external force.

Further, one end (lower end) of the high-pressure lubricating oil return pipe 74 is connected to the front end surface of the connecting joint 80 installed at the center of the left side surface of the cylinder block 6 above the connecting member 78a. The other end (upper end) of the high-pressure lubricating oil return pipe 74 is connected to the lower part of the outer peripheral surface of the high-pressure stage center housing 72 of the high-pressure stage supercharger 51. Further, one end (lower end) of the low-pressure lubricating oil return pipe 77 is connected to a connecting portion that projects diagonally upward forward from the middle portion of the connecting joint 80. On the other hand, the other end (upper end) of the low-pressure lubricating oil return pipe 77 is connected to the lower part of the outer peripheral surface of the low-pressure stage center housing 75 of the low-pressure stage supercharger 52. Therefore, the lubricating oil flowing through the high-pressure stage turbocharger 51 and the low-pressure stage turbocharger 52 is merged from the lower parts of the center housings 72 and 75 via the lubricating oil return pipes 74 and 77 at the connecting joint 80 to form a cylinder block. It is returned to the oil passage in 6.

The high-pressure lubricating oil return pipe 74 is led to the connecting joint 80 from below the high-pressure stage turbine case 53, passing below the exhaust manifold exhaust outlet 49 of the exhaust manifold 4. Further, the low pressure operation return pipe 77 is guided to the connecting joint 80 through between the high pressure exhaust gas pipe 59 and the exhaust manifold 4. In this way, the lubricating oil return pipes 74 and 77 are shortened, and the lubricating oil is efficiently supplied to the two-stage turbocharger 30 by piping so as to cover the two-stage turbocharger 30, which is a highly rigid component. At the same time, it is possible to prevent the lubricating oil return pipes 74 and 77 from being damaged by an external force.

Next, the mounting structure of the exhaust gas purification device 100 will be described with reference to FIGS. 11 to 16 and the like. The exhaust gas purification device 100 is configured by connecting the upstream case 105, the intermediate case 106, and the downstream case 107 in series in that order, and is arranged horizontally and horizontally above the front portion of the cylinder head 2.

The connecting portion between the upstream case 105 and the intermediate case 106 is sandwiched and connected from both sides in the exhaust gas moving direction by a pair of thick plate-shaped holding flanges 108 and 109. That is, the joining flange provided on the downstream opening edge of the upstream case 105 and the joining flange provided on the upstream opening edge of the intermediate case 106 are narrowed by the sandwiching flanges 108 and 109, and the upstream case 105 is held. The downstream side and the upstream side of the intermediate case 106 are connected to form the gas purification housing 104. At this time, by bolting the holding flanges 108 and 109, the upstream side case 105 and the intermediate case 106 are detachably connected to each other.

Further, the connecting portion between the intermediate case 106 and the downstream case 107 is sandwiched and connected from both sides in the exhaust gas moving direction by a pair of thick plate-shaped holding flanges 110 and 111. That is, the joining flange provided on the downstream opening edge of the intermediate case 106 and the joining flange provided on the upstream opening edge of the downstream case 107 are narrowed by the sandwiching flanges 108 and 109, and downstream of the intermediate case 106. The side and the upstream side of the downstream side case 107 are detachably connected to each other.

An exhaust gas inlet pipe 116 is provided on the outer peripheral portion of the upstream case 105 on the exhaust inlet side, and the exhaust intake side of the exhaust gas inlet pipe 116 is via an exhaust connecting member 120 and an exhaust connecting pipe 119 as an exhaust relay path. Therefore, it communicates with the low-pressure stage exhaust outlet 61 (see FIG. 6 and the like) of the two-stage turbocharger 30. The exhaust gas connecting member 120 has a substantially L-shape when viewed from the side, and is connected to the exhaust connecting pipe 119 with the exhaust intake side provided at the rear, while the exhaust gas purifying device 100 is provided with the exhaust exhaust side at the upper side. It is connected to the exhaust gas inlet pipe 116 of. As shown in FIGS. 11, 12 and 16, the exhaust connecting member 120 is detachably attached to the front portion of the left side surface of the support base 121 by a pair of upper and lower bolts 122 and 122.

As shown in FIGS. 11 and 15, the exhaust gas purification device 100 is attached to the front portion of the cylinder head 2 via the left and right support brackets 117 and 118 and the support base 121. The exhaust gas purification device 100 includes a left bracket fastening leg 112 welded and fixed to the lower portion of the outer peripheral surface of the upstream casing 105, and a right bracket fastening leg 113 formed below the holding flange 110.

The left and right support brackets 117 and 118 have a substantially L-shape including a horizontal portion and an upright portion that protrudes upward from the left and right outer ends of the horizontal portion. The horizontal portion of the left support bracket 117 is fixed to the upper left side portion of the flat surface portion 121a of the support base 121 by a pair of front and rear bolts. The horizontal portion of the right support bracket 118 is fixed to the upper right edge portion of the flat surface portion 121a of the support base 121 by a pair of front and rear bolts. The left and right bracket fastening legs 112 and 113 of the exhaust gas purification device 100 are attached to the left and right support brackets 117 and 118 with a pair of front and rear bolts and nuts, respectively.

A notch 118a on which the head of a bolt for fastening the lower portions of the holding flanges 110 and 111 can be temporarily placed is formed on the upper surface of the upright portion of the right support bracket 118. When assembling the exhaust gas purification device 100 to the engine 1, the heads of bolts that fasten the lower parts of the holding flanges 110 and 111 with the left and right support brackets 117 and 118 and the exhaust connecting member 120 attached to the support base 121. The portion is aligned with the notch portion 118a of the right support bracket 118. As a result, the exhaust gas purification device 100 can be aligned with the engine device 1, and the bolt fastening work when assembling the exhaust gas purification device 100 to the engine 1 becomes easy, and the assembly workability is improved.

As shown in FIGS. 11 to 16, the flat surface portion 121a of the support base 121 has a substantially L-shape in which the right portion is longer than the left portion in a plan view. The flat surface portion 121a is arranged so as to cover the front portion of the cylinder head 2 along the front side surface and the right side surface of the cylinder head 2 in a plan view. The exhaust gas purification device 100 is mounted on the flat surface portion 121a.

Further, the support base 121 includes a plurality of leg portions 121b, 121c, 121d, 121e that are projected downward from the flat surface portion 121a and fixed to the cylinder head 2. Between the legs 121b, 121c, 121d, and 121e, a convex arch shape is formed on the upper side. The cylinder head 2 is provided with an exhaust side mounting portion 123b at the front portion on the left side surface, a first central mounting portion 123c provided at a portion near the center portion of the front side surface, and a second center at the right edge portion of the front side surface. The mounting portion 123d is provided, and the intake side mounting portion 123e is provided at the front end portion of the upper surface of the intake manifold 3 integrally molded on the right side surface.

The lower end of the exhaust side leg 121b is fixed to the exhaust side mounting 123b with a pair of front and rear bolts. The lower end of the first central leg portion 121c is fixed to the first central mounting portion 123c with one bolt. The lower portion of the second central leg portion 121d is fixed to the second central mounting portion 123d with a pair of upper and lower bolts. The intake side leg portion 121e includes a pair of front and rear bolt insertion holes bored in the vertical direction, and is attached to the intake side mounting portion 123e with a pair of front and rear bolts inserted through the bolt insertion holes.

As shown in FIGS. 11, 13 to 15, and 21, the intake manifold 3 is integrally molded on the right side surface of the cylinder head 2. Since the intake side leg portion 121e is fixed to the intake side mounting portion 123e provided on the intake manifold 3, the intake side leg portion 121e can be mounted and firmly fixed on the robust intake manifold 3. Further, the tightening and loosening work of the pair of front and rear bolts for fixing the intake side leg portion 121e to the intake manifold 3 can be performed from the upper side of the cylinder head 2. Therefore, for example, with the EGR device 24 (see FIG. 5 and the like) arranged on the right side of the cylinder head 2 attached to the intake manifold 3, the support base 121 can be attached and detached, and the engine 1 can be assembled. Ease of use and maintainability are improved.

As shown in FIGS. 11, 13 and 15, a pair of front and rear reinforcing ribs 124 and 124 are provided on the right side surface and the lower surface of the intake manifold 3 below the intake side mounting portion 123e. The reinforcing ribs 124 and 124 are extended in the vertical direction, and the strength of the intake manifold 3 around the intake side mounting portion 123e can be improved. This makes it possible to prevent the intake manifold 3 and the cylinder head 2 from being deformed due to the attachment of the support base 121 to the intake manifold 3.

As shown in FIGS. 11 to 16, in the support base 121, the flat surface portion 121a and the leg portions 121b, 121c, 121d, 121e are integrally molded, while the arch between the leg portions 121b, 121c, 121d, 121e is formed. Since it is formed in a shape, weight reduction can be realized while ensuring the rigidity of the support base 121. Further, by making the support base 121 an integrally molded part, the number of parts can be reduced. Further, since the arch-shaped gap is formed between the legs 121b, 121c, 121d, 121e, it is possible to prevent the formation of heat pools around the legs 121b, 121c, 121d, 121e. This makes it possible to prevent heat damage to electronic components mounted around the legs of the exhaust pressure sensor 151 and the like, which will be described later, and insufficient cooling of cooling components such as the EGR cooler 27.

Further, the support base 121 is fixed to the exhaust side leg portion 121b fixed to the left side surface of the cylinder head 2, the intake side leg portion 121e fixed to the right side surface of the cylinder head 2, and the front side surface of the cylinder head 2. The central legs 121c and 121d are provided. Therefore, the support base 121 can be fixed to a total of three surfaces, the right side surface, the left side surface, and the front side surface of the cylinder head 2, and the support rigidity of the exhaust gas purification device 100 can be improved.

As shown in FIGS. 11, 13 and 15, the arch shape between the intake side leg 121e and the second central leg 121d, the arch shape between the central legs 121c and 121d, and the exhaust side leg 121b The height and size (width) of the arch shape between the first central leg portion 121c and the first central leg portion 121c are different from each other. Further, the exhaust side leg portion 121b and the intake side leg portion 121e have different lengths in the vertical direction from each other. By appropriately designing the arch shape and the length of the legs, the vibrations on the intake side and the exhaust side can be canceled by the support base 121, and the vibrations of the exhaust gas purification device 100 can be reduced.

As shown in FIGS. 11 and 16, the flat surface portion 121a and the leg portions 121b, 121c, 121d, 121e of the support base 121 are arranged at intervals from the cylinder head cover 18. As a result, a cooling air passage 148 through which the cooling air 149 from the cooling fan 9 (see FIG. 3 and the like) arranged at the rear of the engine 1 flows is formed between the support base 121 and the cylinder head cover 18. Therefore, the cooling air 149 from the cooling fan 9 can be guided to the front side surface side of the cylinder head 2 via the cooling air passage 148, and the periphery of the front side surface of the cylinder head 2 can be appropriately cooled. In this embodiment, since the EGR cooler 27 and the exhaust pressure sensor 151 described later are attached to the front side surface of the cylinder head 2, they are guided from the cooling fan 9 to the front side surface of the cylinder head 2 via the cooling air passage 148. The cooling air 149 can promote cooling of the EGR cooler 27 and prevent heat damage to the exhaust pressure sensor 151.

Next, the configuration around the front side surface of the cylinder head 2 will be described with reference to FIGS. 17 to 21 and the like. As shown in FIG. 21, the cylinder head 2 includes a plurality of intake flow paths 36 that introduce fresh air into a plurality of intake ports (not shown) and a plurality of exhaust flow paths 37 that lead out exhaust gas from the plurality of exhaust ports. Is formed. An intake manifold 3 that collects a plurality of intake flow paths 36 is integrally formed on the right side portion of the cylinder head 2. By integrally configuring the cylinder head 2 and the intake manifold 3, the gas sealability from the intake manifold 3 to the intake flow path 36 can be improved, and the rigidity of the cylinder head 2 can be increased.

On the right side surface of the exhaust manifold 4 connected to the left side surface of the cylinder head 2, an EGR gas outlet 41 communicating with the upstream EGR gas passage 31 in the cylinder head 2 and an exhaust inlet communicating with a plurality of exhaust flow paths 37 42 and 42 are open side by side in the front-rear direction. An exhaust collecting portion 43 communicating with the EGR gas outlet 41 and the exhaust inlet 42 is formed in the exhaust manifold 4. An exhaust manifold exhaust outlet 49 communicating with the exhaust collecting portion 43 is opened at the rear portion of the left side surface of the exhaust manifold 4. When the exhaust gas from the exhaust flow path 37 of the cylinder head 2 flows into the exhaust collecting portion 43 through the exhaust inlet 42, a part of the exhaust gas is converted into EGR gas from the EGR gas outlet 41 to the upstream EGR gas passage 31 in the cylinder head 2. The rest of the exhaust gas flows from the exhaust manifold exhaust outlet 49 into the two-stage supercharger 30 (see FIG. 7 and the like).

The cylinder head 2 has an exhaust manifold 4 connected to a left side surface (exhaust side surface) opposite to the right side surface (intake side surface) on which the intake manifold 3 is integrally molded, and is one of two side surfaces intersecting the exhaust side surface. The EGR cooler 27 is connected to one side surface). Left and right EGR cooler connecting portions 33 and 34 are projected forward at both left and right edge portions (left front corner portion and right front corner portion) of the front side surface of the cylinder head 2. The EGR cooler 27 is connected to the front side surfaces of the left and right EGR cooler connecting portions 33 and 34. EGR gas passages 31 and 32 and cooling water passages 38 and 39 are formed in the EGR cooler connecting portions 33 and 34.

By configuring the EGR gas passages 31 and 32 and the cooling water passages 38 and 39 in the EGR cooler connecting portions 33 and 34, it is necessary to provide a cooling water pipe and an EGR gas pipe between the EGR cooler 27 and the cylinder head 2. Absent. Therefore, it is not affected by the expansion and contraction of the piping due to EGR gas and cooling water, and not only the sealing property at the connecting portion with the EGR cooler 27 can be ensured, but also the resistance to external fluctuation elements due to heat and vibration (structural stability). In addition to improving the property), it can be configured compactly.

As shown in FIGS. 17, 20 and 21, an upstream EGR gas passage 31 is provided in the left EGR cooler connecting portion 33, and a downstream EGR gas passage 32 is provided in the right EGR cooler connecting portion 34. The upstream EGR gas passage 31 is substantially L-shaped in a plan view, and one end and the other end are open on the front side surface and the left side surface of the left EGR cooler connecting portion 33, and the lower left portion of the back surface of the EGR cooler 27 and the exhaust An EGR gas outlet 41 provided at a portion closer to the front on the right side surface of the manifold 4 is connected. The downstream EGR gas passage 32 has a substantially L-shape in a plan view, and one end and the other end are open on the front side surface and the right side surface of the right EGR cooler connecting portion 34, and the EGR cooler 27 has a rear upper right portion and the rear right portion. The EGR gas inlet of the circulation exhaust gas pipe 28 is connected.

In the left EGR cooler connecting portion 33, a downstream cooling water channel 38 that is guided from the front side surface to the rear side of the left EGR cooler connecting portion 33 is formed. The downstream cooling water passage 38 is provided above the upstream EGR gas passage 31, and sends the cooling water discharged from the upper left portion of the back surface of the EGR cooler 27 to the cooling water passage in the cylinder head 2. Further, in the right EGR cooler connecting portion 34, an upstream cooling water channel 39 leading from the front side surface to the rear side of the right EGR cooler connecting portion 34 is formed. The upstream cooling water passage 39 is provided below the downstream EGR gas passage 32, and sends the cooling water flowing through the cooling water passage in the cylinder head 2 to the lower right portion on the back surface of the EGR cooler 27.

As shown in FIGS. 17 to 20, an exhaust pressure sensor 151 for detecting the exhaust gas pressure in the exhaust manifold 4 is provided on the front side surface of the cylinder head 2. The exhaust pressure sensor 151 is attached to an exhaust pressure sensor mounting portion 152 projecting forward at a portion of the front side surface of the cylinder head 2 near the center. The exhaust pressure sensor mounting portion 152 is provided between the left and right EGR cooler connecting portions 33 and 34. In the engine 1 of this embodiment, the left edge portion of the exhaust pressure sensor mounting portion 152 is continuously formed at the upper right edge portion of the left EGR cooler connecting portion 33.

The exhaust pressure sensor 151 is connected to the exhaust manifold 4 via an exhaust pressure bypass path 153 provided in the cylinder head 2 and an exhaust pressure detection pipe 154 that connects the exhaust pressure bypass path 153 and the exhaust manifold 4. The exhaust pressure bypass path 153 is bored from the front end portion of the left side surface of the cylinder head 2 toward the right side, and is guided to the inside of the exhaust pressure sensor mounting portion 152 through the inside of the left EGR cooler connecting portion 33. Further, the exhaust pressure bypass path 153 is bent toward the front side in the exhaust pressure sensor mounting portion 152 and opens to the front side surface of the exhaust pressure sensor mounting portion 152. A hole filling member 155 that closes the end of the exhaust pressure bypass path 153 is attached to the front surface of the exhaust pressure sensor mounting portion 152.

As shown in FIG. 18, the exhaust pressure sensor mounting portion 152 includes a sensor mounting hole 152a that is bored downward from the upper surface thereof and is connected to the exhaust pressure bypass path 153. With the exhaust pressure sensor 151 attached to the sensor mounting hole 152a, the lower end of the exhaust pressure sensor 151 is exposed to the exhaust pressure bypass path 153.

On the other hand, the exhaust pressure detection pipe 154 is arranged on the left side of the front portion of the left side surface of the cylinder head 2 and above the exhaust manifold 4. A detection pipe mounting pedestal 156 is projected upward at a portion near the front of the upper surface of the exhaust manifold 4. The rear joint member 157 is attached to the upper surface of the detection pipe mounting pedestal 156. Further, the front joint member 158 is attached to the end of the exhaust pressure bypass path 153 that opens at the front end portion of the left side surface of the cylinder head 2. The front end of the exhaust pressure detection pipe 154 is connected to the exhaust pressure bypass path 153 via the front joint member 158. The rear end of the exhaust pressure detection pipe 154 is connected to the exhaust collecting portion 43 (see FIG. 21) in the exhaust manifold 4 via the rear joint member 157. An exhaust gas temperature sensor 159 is attached to the upper surface of the detection pipe mounting pedestal 156 at a position in front of the rear joint member 157. The exhaust gas temperature sensor 159 detects the temperature of the exhaust gas flowing through the exhaust collecting portion 43 in the exhaust manifold 4.

The heat transferred from the exhaust manifold 4 to the exhaust pressure detection pipe 154, which becomes hot, is diffused by the cylinder head 2 via the front joint member 158. As a result, the heat of the exhaust manifold 4 and the heat of the exhaust pressure detection pipe 154 are not directly transferred to the heat-sensitive exhaust pressure sensor 151. Therefore, the length of the exhaust pressure detection pipe 154 can be shortened while preventing the exhaust pressure sensor 151 from malfunctioning or malfunctioning due to the heat of the exhaust manifold 4 and the exhaust pressure detection pipe 154. Further, by shortening the length of the exhaust pressure detection pipe 154, the reliability of the exhaust pressure detection pipe 154 is improved and the arrangement of the exhaust pressure detection pipe 154 is facilitated, which reduces the design man-hours and reduces the design man-hours and the engine 1. It is possible to improve the man-hours and assembling properties.

As shown in FIGS. 17 and 20, since the downstream cooling water channel 38 is provided in the vicinity of the exhaust pressure bypass path 153 in the left EGR cooler connecting portion 33, the gas temperature in the exhaust pressure bypass path 153 is made efficient. Can be reduced well. Therefore, the exhaust pressure bypass path 153 can be shortened while keeping the heat transferred from the gas in the exhaust pressure bypass path 153 to the exhaust pressure sensor 151 within an allowable range, and the exhaust pressure bypass path 153 can be easily formed in the cylinder head 2. Become. Further, since the exhaust pressure bypass path 153 passes through the inside of the left EGR cooler connecting portion 33 and the exhaust pressure sensor mounting portion 152 projecting from the front side surface of the cylinder head 2, the gas in the exhaust pressure bypass path 153 is passed. It can be cooled efficiently and can prevent the exhaust pressure sensor 151 from malfunctioning or malfunctioning due to heat. Further, since the exhaust pressure sensor 151 is attached to the exhaust pressure sensor mounting portion 152 projecting from the front side surface of the cylinder head 2 between the pair of EGR cooler connecting portions 33 and 34, the exhaust pressure sensor 151 is made efficient. It can be cooled well and can prevent the exhaust pressure sensor 151 from malfunctioning or malfunctioning due to heat.

Further, as shown in FIG. 19, the mounting position of the front joint member 158 is provided at a position higher than the upper surface of the detection pipe mounting pedestal 156. The exhaust pressure detection pipe 154 extends diagonally forward to the left from the rear joint member 157, then bypasses the exhaust gas temperature sensor 159 and is guided diagonally upward while curving to the right. , Arranged in a substantially horizontal direction toward the front along the left side surface of the cylinder head 2, and connected to the front joint member 158. The exhaust pressure detection pipe 154 is arranged at a position where the end portion on the front side joint member 158 side is higher than the end portion on the rear side joint member 157 side. Therefore, it is possible to prevent the oil and water contained in the exhaust gas from becoming liquid in the exhaust pressure detection pipe 154 and entering the exhaust pressure bypass path 153, and the exhaust gas pressure can be accurately detected.

As shown in FIGS. 17 to 21, the configuration in which the EGR cooler connecting portions 33 and 34 are projected makes it unnecessary to use a pipe for EGR gas that connects the exhaust manifold 4, the EGR cooler 27, and the EGR device 24. There are fewer connections in the EGR gas passage. Therefore, in the engine 1 for reducing NOx by EGR gas, not only EGR gas leakage can be reduced, but also deformation due to stress change due to expansion and contraction of the pipe can be suppressed. Further, since the EGR gas passages 31 and 32 and the cooling water passages 38 and 39 are formed in the EGR cooler connecting portions 33 and 34, the shapes of the passages 31, 32, 38 and 39 configured in the cylinder head 2 are simple. Therefore, the cylinder head 2 can be easily cast without using a complicated core.

Further, since the left EGR cooler connecting portion 33 on the exhaust manifold 4 side and the right EGR cooler connecting portion 34 on the intake manifold 3 side are separated from each other, mutual influences due to thermal deformation in each of the EGR cooler connecting portions 33 and 34 are exerted. Can be suppressed. Therefore, not only can gas leakage, cooling water leakage, and damage at the connecting portion between the EGR cooler connecting portions 33 and 34 and the EGR cooler 27 be prevented, but also the rigidity balance of the cylinder head 2 can be maintained. Further, since the volume on the front side surface of the cylinder head 2 can be reduced, the weight of the cylinder head 2 can be reduced. Further, since the EGR cooler 27 can be arranged so as to be separated from the front side surface of the cylinder head 2 and have a space in front of and behind the EGR cooler 27, cooling air can flow around the EGR cooler 27, and the EGR cooler 27 can flow. It is possible to increase the cooling efficiency in.

As shown in FIG. 17, the downstream cooling water channel 38 and the upstream EGR gas passage 31 are vertically arranged in the left EGR cooler connecting portion 33, and the downstream EGR gas is arranged in the right EGR cooler connecting portion 34. The passage 32 and the upstream cooling water channel 39 are arranged vertically. The cooling water inlet of the downstream cooling water channel 38 and the EGR gas inlet of the downstream EGR gas passage 32 are arranged at the same height, while the cooling water outlet of the upstream cooling water channel 39 and the downstream EGR gas passage 32. The EGR gas outlet is arranged at the same height.

The effects of thermal deformation on both the EGR cooler connecting portions 33 and 34 are affected by the configuration in which the EGR gas passages 31 and 32 and the cooling water passages 38 and 39 are internally provided in the separately protruding EGR cooler connecting portions 33 and 34. Is relaxed. Further, in the EGR cooler connecting portions 33 and 34, the EGR gas flowing through the EGR gas passages 31 and 32 is cooled by the cooling water flowing through the cooling water passages 38 and 39, and the thermal deformation itself in the EGR cooler connecting portions 33 and 34 is suppressed. To. Further, in each of the EGR cooler connecting portions 33 and 34, the EGR gas passages 31 and 32 and the cooling water passages 38 and 39 are arranged so as to replace their respective vertical height positions. Therefore, the heat distribution at the EGR cooler connecting portions 33 and 34 is upside down, and the influence of thermal deformation in the height direction on the cylinder head 2 can be reduced.

Next, a part of the harness structure arranged around the front side surface of the cylinder head 2 will be described with reference to FIGS. 22 and 23. In the engine 1 of this embodiment, a harness assembly 171 in which a plurality of harnesses are bundled is arranged in the front-rear direction along the right side surface of the cylinder head cover 18. The harness assembly 171 is branched from a main harness assembly (not shown) extending from an external connection harness connector (not shown) attached to the engine 1.

The front end portion of the harness assembly 171 is arranged between the cylinder head cover 18 and the intake side leg portion 121e of the support base 121. The harness assembly 171 is branched into an EGR valve harness 172, an EGR gas temperature sensor harness 173, and a sensor harness assembly 174 in the vicinity of the right front corner of the cylinder head cover 18. The EGR valve harness 172 is electrically connected to the EGR valve member 29 through between the second central leg portion 121d of the support base 121 and the intake side leg portion 121e. The EGR gas temperature sensor harness 173 is electrically connected to the EGR gas temperature sensor 181 that detects the exhaust gas temperature in the recirculation exhaust gas pipe 28 through between the second central leg portion 121d and the intake side leg portion 121e. ..

The sensor harness assembly 174 is guided from the harness assembly 171 toward the left side, and is bent downward in front of the front side surface right side portion of the cylinder head cover 18. The front end portion of the sensor harness assembly 174 is branched into a rotation angle sensor harness assembly 175 and an exhaust pressure sensor harness 176. The exhaust pressure sensor harness 176 is guided from the harness assembly 174 to the left side through between the cylinder head cover 18 and the first central leg portion 121c of the support base 121, and is electrically connected to the exhaust pressure sensor 151.

The rotation angle sensor harness assembly 175 extends downward from the sensor harness assembly 174 along the front side surface of the cylinder head 2. Further, the rotation angle sensor harness assembly 175 is bent toward the left side at a position directly above the flywheel housing 7, and is guided to a front position of the lower left corner of the front side surface of the cylinder head 2. The rotation angle sensor harness assembly 175 is branched into a crankshaft rotation angle sensor harness 177 and a camshaft rotation angle sensor harness 178. The crankshaft rotation angle sensor harness 177 is electrically connected to a crankshaft rotation angle sensor 182 (see FIG. 1) attached to a portion near the upper left of the front portion of the flywheel housing 7. The camshaft rotation angle sensor harness 178 is electrically connected to a camshaft rotation angle sensor 183 (see FIG. 1) attached to the upper left edge of the flywheel housing 7.

As shown in FIG. 17, locking member mounting portions 185 and 186 arranged vertically are formed on the left and right central portions of the front side surface of the cylinder head 2. The upper locking member mounting portion 185 is arranged at an upper portion on the front side surface of the cylinder head 2 at a position between the right EGR cooler connecting portion 34 and the first central mounting portion 123c. The lower locking member mounting portion 186 is arranged at a lower portion of the front side surface of the cylinder head 2 at a position directly below the upper locking member mounting portion 185 between the left and right EGR cooler connecting portions 33 and 34. ..

As shown in FIGS. 22 and 23, the rotation angle sensor harness assembly 175 of the portion facing the front side surface of the cylinder head 2 is formed by the locking members 187 and 188 attached to the upper and lower locking member mounting portions 185 and 186. , Attached to the front surface of the cylinder head 2. Then, the rotation angle sensor harness assembly 175 passes from the harness assembly 174 between the right EGR cooler connecting portion 34 and the first central leg portion 121c of the support base 121, and between the cylinder head 2 and the EGR cooler 27. , The cylinder head 2 is guided to a position facing the lower edge portion of the front side surface.

The EGR cooler 27 is attached to a pair of left and right EGR cooler connecting portions 33, 34 projecting forward from the front side surface of the cylinder head 2. Then, a space is formed between the back surface of the EGR cooler 27 and the cylinder head 2. By arranging the rotation angle sensor harness assembly 175 in the vertical direction in this space, the rotation angle sensor harness assembly 175 can be protected and the layout design of the rotation angle sensor harness assembly 175 becomes easy.

Further, a space is formed between the side surface of the cylinder head cover 18 and the support base 121. By arranging the harness aggregates 171 and 174 and the harnesses 172, 173, and 176 using this space, these harnesses and the harness aggregates can be protected, and the layout design of the harness becomes easy.

As shown in FIGS. 1 to 10, the engine 1 is driven by an exhaust manifold 4 provided on an exhaust side surface (for example, a left side surface) which is one side surface of the cylinder head 2 and exhaust gas discharged from the exhaust manifold 4. A stage supercharger 30 is provided. The two-stage turbocharger 30 is composed of a high-pressure stage turbocharger 51 connected to the exhaust manifold 4 and a low-pressure stage turbocharger 52 connected to the high-pressure stage turbocharger 51. Since the high-pressure turbocharger 51 is arranged on the side of the exhaust manifold 4 and the low-pressure turbocharger 52 is arranged above the exhaust manifold 4, the exhaust manifold 4 and the two-stage turbocharger 30 are placed in a substantially square frame. It can be arranged compactly and the engine 1 can be downsized. Further, the high-pressure stage exhaust port 58 of the high-pressure stage turbocharger 51 and the low-pressure stage exhaust inlet 60 of the low-pressure stage supercharger 52 are connected via a high-pressure exhaust gas pipe 59 as an example of a flexible pipe. Therefore, the risk of low-cycle fatigue failure of the high-pressure exhaust gas pipe 59 due to thermal elongation can be reduced.

In the engine 1, the low-pressure turbocharger 52 is fixed to the exhaust side surface of the cylinder head 2, and the high-pressure turbocharger 51 is fixed to the exhaust manifold 4. Therefore, the high-pressure turbocharger forming the two-stage turbocharger 30 is formed. The feeder 51 and the low-pressure turbocharger 52 can be distributed to the robust cylinder head 2 and the exhaust manifold 4 and firmly fixed. Further, since the high-pressure stage exhaust outlet 58 of the high-pressure stage turbocharger 51 and the low-pressure stage exhaust inlet 60 of the low-pressure stage supercharger 52 are connected via a flexible high-pressure exhaust gas pipe 59, high-pressure exhaust is performed. The stress applied to the two-stage turbocharger 30 due to the thermal elongation of the gas pipe 59 can be reduced. As a result, the stress applied to the connecting portion between the high-pressure stage turbocharger 51 and the exhaust manifold 4 and the stress applied to the connecting portion between the low-pressure stage supercharger 52 and the cylinder head 2 can be reduced, resulting in poor connection or connection at these connecting portions. It is possible to prevent damage to the members.

Further, since the cylinder head 2 is provided with a rib 135 extending from the low pressure stage turbocharger mounting portion 131 on the exhaust side surface toward the intake side surface (for example, the right side surface) facing the exhaust side surface. In the cylinder head 2, the rigidity around the low-pressure turbocharger mounting portion 131 can be improved, and deformation of the cylinder head 2 due to the mounting of the low-pressure turbocharger 52 on the cylinder head 2 can be prevented.

Further, the engine 1 includes an exhaust gas purifying device 100 that purifies the exhaust gas from the engine 1. The exhaust gas inlet pipe 116 as the exhaust inlet of the exhaust gas purification device 100 is arranged near the corner where one side surface of the cylinder head 2 intersecting the exhaust side surface and the exhaust side surface intersect, and has a low pressure. The stage supercharger 52 is arranged closer to the one side surface when viewed from the exhaust side surface side, and the low pressure stage exhaust outlet 61 of the low pressure stage supercharger 52 is provided toward the one side surface side. .. Therefore, the engine 1 shortens and simplifies the exhaust connecting pipe 119 and the exhaust connecting member 120 as an example of the pipe connecting the low pressure stage exhaust outlet 61 of the low pressure stage supercharger 52 and the exhaust gas inlet pipe 116 of the exhaust gas purification device 100. Can be done. As a result, the exhaust gas supplied to the exhaust gas purification device 100 can be maintained at a high temperature, and a decrease in the regeneration ability of the exhaust gas purification device 100 can be prevented.

Further, above the cylinder head 2, the blow-by gas outlet 70 of the blow-by gas reduction device 19 is arranged toward the exhaust side surface side at a position closer to the other side surface opposite to the one side surface of the cylinder head 2. The low-pressure stage fresh air inlet 63 of the stage supercharger 52 is provided toward the other side surface side. Further, the blow-by gas outlet 70 is connected to the air supply pipe 62 connected to the low pressure stage fresh air inlet 63 of the low pressure stage turbocharger 52 via the reduction hose 68. Therefore, in the engine 1, both the blow-by gas outlet 70 of the blow-by gas reduction device 19 and the air supply pipe 62 connected to the low-pressure stage fresh air inlet 63 of the low-pressure stage supercharger 52 are connected to the other side surface of the cylinder head 2. By arranging the reduction hose 68 at the position, the reduction hose 68 can be shortened, and measures against freezing inside the reduction hose 68 become unnecessary.

As shown in FIGS. 1 to 5 and 11 to 16, the engine 1 includes an exhaust gas purification device 100 above the cylinder head 2 via a support base 121. The support base 121 includes a flat surface portion 121a on which the exhaust gas purification device 100 is mounted, and a plurality of leg portions 121b, 121c, 121d, 121e that are projected downward from the flat surface portion 121a and fixed to the cylinder head 2. Be prepared. The flat surface portion 121a and the leg portions 121b, 121c, 121d, 121e are integrally molded. Further, the legs 121b, 121c, 121d, 121e are formed in an arch shape between the legs. Therefore, due to the integrally molded structure and the arch shape, weight reduction can be realized while ensuring the rigidity of the support base 121. Further, by making the support base 121 an integrally molded part, the number of parts can be reduced. Further, since the arch-shaped gap is formed between the plurality of legs 121b, 121c, 121d, 121e, it is possible to prevent the formation of heat pools around the legs of the support base 121, for example, the legs. It is possible to prevent heat damage to electronic parts such as the exhaust pressure sensor 151 as an example of sensors mounted in the vicinity and insufficient cooling of cooling parts such as the EGR cooler 27.

The engine 1 has a configuration in which the exhaust manifold 4 and the intake manifold 3 are separately arranged on the exhaust side surface and the intake side surface of the cylinder heads 2 facing each other. The support base 121 is arranged above one of the two side surfaces of the cylinder head 2 that intersects the axial direction of the crankshaft 5, and also has the exhaust side leg portion 121b fixed to the exhaust side surface as a leg portion. It has an intake side leg 121e fixed to the intake side surface and central legs 121c and 121d fixed to one of the above side surfaces. Therefore, the engine 1 can fix the support base 121 to a total of three surfaces of the exhaust side surface, the intake side surface, and one of the above side surfaces of the cylinder head 2, and can improve the support rigidity of the exhaust gas purification device 100. Further, the height and size of both arch shapes may be different between the exhaust side leg 121b and the first central leg 121c and the intake side leg 121e and the second central leg 121d. By making the lengths of the exhaust side leg 121b and the intake side leg 121e different, the vibrations on the intake side and the exhaust side can be canceled by the support base 121, and the vibration of the exhaust gas purification device 100 is reduced. it can.

Further, the engine 1 is configured to include a cooling fan 9 on the other side surface side of the above two side surfaces of the cylinder head 2. A cooling air passage 148 through which the cooling air 149 from the cooling fan 9 flows is formed between the cylinder head cover 18 on the cylinder head 2 and the support base 121. Therefore, the engine 1 can guide the cooling air from the cooling fan 9 to the one side surface side of the cylinder head 2 via the cooling air passage 148, and can appropriately cool the periphery of the one side surface of the cylinder head 2.

Further, the engine 1 includes an EGR device 24 that returns a part of the exhaust gas discharged from the exhaust manifold 4 to the intake manifold 3 as EGR gas, an EGR cooler 27 that cools the EGR gas, and an exhaust gas pressure in the exhaust manifold 4. It is configured to include an exhaust pressure sensor 151 for detecting. An EGR cooler 27 and an exhaust pressure sensor 151 are attached to the one side surface of the cylinder head 2. Therefore, the cooling air 149 guided from the cooling fan 9 to the one side surface via the cooling air passage 148 can promote cooling of the EGR cooler 27 and prevent heat damage to the exhaust pressure sensor 151.

Further, in the engine 1, the intake manifold 3 is integrally molded on the intake side surface of the cylinder head 2, and the intake side leg portion 121e is fixed to the upper surface of the intake manifold 3, so that the intake can be robust. The intake side leg portion 121e can be placed on the manifold 3 and firmly fixed. Further, since the bolt tightening work for fixing the intake side leg portion 121e to the intake manifold 3 can be performed from the upper side of the cylinder head 2, the EGR device 24 arranged on the side of the intake side surface of the cylinder head 2 is sucked. The support base 121 can be attached and detached while it is attached to the manifold 3, and the assembling workability and maintainability of the engine 1 are improved.

As shown in FIGS. 1 to 5 and 17 to 21, the engine 1 includes an exhaust manifold 4 provided on the exhaust side surface of the cylinder head 2 and an exhaust pressure sensor 151 for detecting the exhaust gas pressure in the exhaust manifold 4. Be prepared. The exhaust pressure sensor 151 is attached to the cylinder head 2, and the exhaust manifold 4 and the exhaust pressure sensor 151 detect the exhaust pressure bypass path 153 provided in the cylinder head 2, the exhaust pressure bypass path 153, and the exhaust manifold 4. Since it is connected via the pipe 154, the heat of the exhaust pressure detection pipe 154 can be diffused by the cylinder head 2. Therefore, the engine 1 can shorten the length of the exhaust pressure detection pipe 154 while preventing the exhaust pressure sensor 151 from malfunctioning or malfunctioning due to the heat of the exhaust manifold 4 and the exhaust pressure detection pipe 154. Further, by shortening the length of the exhaust pressure detection pipe 154, the reliability of the exhaust pressure detection pipe 154 is improved, and the arrangement of the exhaust pressure detection pipe 154 is facilitated, which reduces the design man-hours and reduces the engine. It is possible to improve the man-made property and the assembling property of 1. Further, in the engine 1, since the cooling water passage 38 is provided in the vicinity of the exhaust pressure bypass path 153 in the cylinder head 2, the gas temperature in the exhaust pressure bypass path 153 can be efficiently reduced. Therefore, the engine 1 can shorten the exhaust pressure bypass path 153 while keeping the heat transferred from the gas in the exhaust pressure bypass path 153 to the exhaust pressure sensor 151 within an allowable range, and the exhaust pressure bypass path 153 to the cylinder head 2 can be shortened. Easy to form.

The engine 1 includes an EGR device 24 that returns a part of the exhaust gas discharged from the exhaust manifold 4 to the intake manifold 3 as EGR gas, and an EGR cooler 27 that cools the EGR gas. The cylinder head 2 includes a pair of EGR cooler connecting portions 33 and 34 projecting from one of the two side surfaces of the cylinder head 2 intersecting the exhaust side surface, and the cooling water channel 38 is provided with one EGR cooler connecting portion. It is connected to the EGR cooler 37 through the inside of the 33, and the exhaust pressure bypass path 153 passes through the inside of the EGR cooler connecting portion 33. Therefore, the engine 1 can efficiently cool the gas in the exhaust pressure bypass path 153, and can prevent the exhaust pressure sensor 151 from failing or malfunctioning due to heat.

Further, the exhaust pressure sensor 151 is attached to the exhaust pressure sensor mounting portion 152 projecting from the one side surface of the cylinder head 2 between the pair of EGR cooler connecting portions 33 and 34. Therefore, the engine 1 can efficiently cool the exhaust pressure sensor 151, and can prevent a failure or malfunction of the exhaust pressure sensor 151 due to heat.

The configuration of each part in the present invention is not limited to the illustrated embodiment, and various changes can be made without departing from the spirit of the present invention.

1 Engine (engine device)
2 Cylinder head 3 Intake manifold 4 Exhaust manifold 30 Two-stage turbocharger 51 High-pressure stage turbocharger 52 Low-pressure stage turbocharger 59 High-pressure exhaust gas piping (flexible piping)
131 Low-pressure stage turbocharger mounting part 135 Rib 100 Exhaust gas purification device 116 Exhaust gas inlet pipe (exhaust gas inlet of exhaust gas purification device)
19 Blow-by gas reduction device 70 Blow-by gas outlet 63 Low-pressure stage fresh air inlet (new air inlet of low-pressure stage turbocharger)
62 Air supply pipe 68 Reduction hose

Claims (6)

In an engine device in which an exhaust gas purification device is provided via a support base
A cooling air passage through which cooling air from the cooling fan flows is formed between the cylinder head cover on the cylinder head and the support base.
Engine device. The support base includes a mounting portion on which the exhaust gas purification device is mounted, and a plurality of legs fixed to the cylinder head.
The engine device according to claim 1. The support base is arranged above one side surface of the two side surfaces of the cylinder head that intersects the exhaust side surface and the intake side surface of the cylinder head, and the exhaust side fixed to the exhaust side surface as the leg portion. It includes a leg portion, an intake side leg portion fixed to the intake side surface, and a central leg portion fixed to the one side surface.
The engine device according to claim 2. The cooling fan is provided on the other side surface side of the two side surfaces of the cylinder head.
The engine device according to claim 3. A configuration including an EGR device that returns a part of the exhaust gas discharged from the exhaust manifold to the intake manifold as EGR gas, an EGR cooler that cools the EGR gas, and an exhaust pressure sensor that detects the exhaust gas pressure in the exhaust manifold. And
The EGR cooler and the exhaust pressure sensor are attached to the one side surface of the cylinder head.
The engine device according to claim 3. An intake manifold is provided on the intake side surface of the cylinder head.
The intake side leg is fixed to the intake manifold.
The engine device according to claim 3.